1  /* SPDX-License-Identifier: GPL-2.0-or-later */
2  /*
3   *	Definitions for the 'struct sk_buff' memory handlers.
4   *
5   *	Authors:
6   *		Alan Cox, <gw4pts@gw4pts.ampr.org>
7   *		Florian La Roche, <rzsfl@rz.uni-sb.de>
8   */
9  
10  #ifndef _LINUX_SKBUFF_H
11  #define _LINUX_SKBUFF_H
12  
13  #include <linux/kernel.h>
14  #include <linux/compiler.h>
15  #include <linux/time.h>
16  #include <linux/bug.h>
17  #include <linux/bvec.h>
18  #include <linux/cache.h>
19  #include <linux/rbtree.h>
20  #include <linux/socket.h>
21  #include <linux/refcount.h>
22  
23  #include <linux/atomic.h>
24  #include <asm/types.h>
25  #include <linux/spinlock.h>
26  #include <net/checksum.h>
27  #include <linux/rcupdate.h>
28  #include <linux/dma-mapping.h>
29  #include <linux/netdev_features.h>
30  #include <net/flow_dissector.h>
31  #include <linux/in6.h>
32  #include <linux/if_packet.h>
33  #include <linux/llist.h>
34  #include <net/flow.h>
35  #if IS_ENABLED(CONFIG_NF_CONNTRACK)
36  #include <linux/netfilter/nf_conntrack_common.h>
37  #endif
38  #include <net/net_debug.h>
39  #include <net/dropreason-core.h>
40  #include <net/netmem.h>
41  
42  /**
43   * DOC: skb checksums
44   *
45   * The interface for checksum offload between the stack and networking drivers
46   * is as follows...
47   *
48   * IP checksum related features
49   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
50   *
51   * Drivers advertise checksum offload capabilities in the features of a device.
52   * From the stack's point of view these are capabilities offered by the driver.
53   * A driver typically only advertises features that it is capable of offloading
54   * to its device.
55   *
56   * .. flat-table:: Checksum related device features
57   *   :widths: 1 10
58   *
59   *   * - %NETIF_F_HW_CSUM
60   *     - The driver (or its device) is able to compute one
61   *	 IP (one's complement) checksum for any combination
62   *	 of protocols or protocol layering. The checksum is
63   *	 computed and set in a packet per the CHECKSUM_PARTIAL
64   *	 interface (see below).
65   *
66   *   * - %NETIF_F_IP_CSUM
67   *     - Driver (device) is only able to checksum plain
68   *	 TCP or UDP packets over IPv4. These are specifically
69   *	 unencapsulated packets of the form IPv4|TCP or
70   *	 IPv4|UDP where the Protocol field in the IPv4 header
71   *	 is TCP or UDP. The IPv4 header may contain IP options.
72   *	 This feature cannot be set in features for a device
73   *	 with NETIF_F_HW_CSUM also set. This feature is being
74   *	 DEPRECATED (see below).
75   *
76   *   * - %NETIF_F_IPV6_CSUM
77   *     - Driver (device) is only able to checksum plain
78   *	 TCP or UDP packets over IPv6. These are specifically
79   *	 unencapsulated packets of the form IPv6|TCP or
80   *	 IPv6|UDP where the Next Header field in the IPv6
81   *	 header is either TCP or UDP. IPv6 extension headers
82   *	 are not supported with this feature. This feature
83   *	 cannot be set in features for a device with
84   *	 NETIF_F_HW_CSUM also set. This feature is being
85   *	 DEPRECATED (see below).
86   *
87   *   * - %NETIF_F_RXCSUM
88   *     - Driver (device) performs receive checksum offload.
89   *	 This flag is only used to disable the RX checksum
90   *	 feature for a device. The stack will accept receive
91   *	 checksum indication in packets received on a device
92   *	 regardless of whether NETIF_F_RXCSUM is set.
93   *
94   * Checksumming of received packets by device
95   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
96   *
97   * Indication of checksum verification is set in &sk_buff.ip_summed.
98   * Possible values are:
99   *
100   * - %CHECKSUM_NONE
101   *
102   *   Device did not checksum this packet e.g. due to lack of capabilities.
103   *   The packet contains full (though not verified) checksum in packet but
104   *   not in skb->csum. Thus, skb->csum is undefined in this case.
105   *
106   * - %CHECKSUM_UNNECESSARY
107   *
108   *   The hardware you're dealing with doesn't calculate the full checksum
109   *   (as in %CHECKSUM_COMPLETE), but it does parse headers and verify checksums
110   *   for specific protocols. For such packets it will set %CHECKSUM_UNNECESSARY
111   *   if their checksums are okay. &sk_buff.csum is still undefined in this case
112   *   though. A driver or device must never modify the checksum field in the
113   *   packet even if checksum is verified.
114   *
115   *   %CHECKSUM_UNNECESSARY is applicable to following protocols:
116   *
117   *     - TCP: IPv6 and IPv4.
118   *     - UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
119   *       zero UDP checksum for either IPv4 or IPv6, the networking stack
120   *       may perform further validation in this case.
121   *     - GRE: only if the checksum is present in the header.
122   *     - SCTP: indicates the CRC in SCTP header has been validated.
123   *     - FCOE: indicates the CRC in FC frame has been validated.
124   *
125   *   &sk_buff.csum_level indicates the number of consecutive checksums found in
126   *   the packet minus one that have been verified as %CHECKSUM_UNNECESSARY.
127   *   For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
128   *   and a device is able to verify the checksums for UDP (possibly zero),
129   *   GRE (checksum flag is set) and TCP, &sk_buff.csum_level would be set to
130   *   two. If the device were only able to verify the UDP checksum and not
131   *   GRE, either because it doesn't support GRE checksum or because GRE
132   *   checksum is bad, skb->csum_level would be set to zero (TCP checksum is
133   *   not considered in this case).
134   *
135   * - %CHECKSUM_COMPLETE
136   *
137   *   This is the most generic way. The device supplied checksum of the _whole_
138   *   packet as seen by netif_rx() and fills in &sk_buff.csum. This means the
139   *   hardware doesn't need to parse L3/L4 headers to implement this.
140   *
141   *   Notes:
142   *
143   *   - Even if device supports only some protocols, but is able to produce
144   *     skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
145   *   - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols.
146   *
147   * - %CHECKSUM_PARTIAL
148   *
149   *   A checksum is set up to be offloaded to a device as described in the
150   *   output description for CHECKSUM_PARTIAL. This may occur on a packet
151   *   received directly from another Linux OS, e.g., a virtualized Linux kernel
152   *   on the same host, or it may be set in the input path in GRO or remote
153   *   checksum offload. For the purposes of checksum verification, the checksum
154   *   referred to by skb->csum_start + skb->csum_offset and any preceding
155   *   checksums in the packet are considered verified. Any checksums in the
156   *   packet that are after the checksum being offloaded are not considered to
157   *   be verified.
158   *
159   * Checksumming on transmit for non-GSO
160   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
161   *
162   * The stack requests checksum offload in the &sk_buff.ip_summed for a packet.
163   * Values are:
164   *
165   * - %CHECKSUM_PARTIAL
166   *
167   *   The driver is required to checksum the packet as seen by hard_start_xmit()
168   *   from &sk_buff.csum_start up to the end, and to record/write the checksum at
169   *   offset &sk_buff.csum_start + &sk_buff.csum_offset.
170   *   A driver may verify that the
171   *   csum_start and csum_offset values are valid values given the length and
172   *   offset of the packet, but it should not attempt to validate that the
173   *   checksum refers to a legitimate transport layer checksum -- it is the
174   *   purview of the stack to validate that csum_start and csum_offset are set
175   *   correctly.
176   *
177   *   When the stack requests checksum offload for a packet, the driver MUST
178   *   ensure that the checksum is set correctly. A driver can either offload the
179   *   checksum calculation to the device, or call skb_checksum_help (in the case
180   *   that the device does not support offload for a particular checksum).
181   *
182   *   %NETIF_F_IP_CSUM and %NETIF_F_IPV6_CSUM are being deprecated in favor of
183   *   %NETIF_F_HW_CSUM. New devices should use %NETIF_F_HW_CSUM to indicate
184   *   checksum offload capability.
185   *   skb_csum_hwoffload_help() can be called to resolve %CHECKSUM_PARTIAL based
186   *   on network device checksumming capabilities: if a packet does not match
187   *   them, skb_checksum_help() or skb_crc32c_help() (depending on the value of
188   *   &sk_buff.csum_not_inet, see :ref:`crc`)
189   *   is called to resolve the checksum.
190   *
191   * - %CHECKSUM_NONE
192   *
193   *   The skb was already checksummed by the protocol, or a checksum is not
194   *   required.
195   *
196   * - %CHECKSUM_UNNECESSARY
197   *
198   *   This has the same meaning as CHECKSUM_NONE for checksum offload on
199   *   output.
200   *
201   * - %CHECKSUM_COMPLETE
202   *
203   *   Not used in checksum output. If a driver observes a packet with this value
204   *   set in skbuff, it should treat the packet as if %CHECKSUM_NONE were set.
205   *
206   * .. _crc:
207   *
208   * Non-IP checksum (CRC) offloads
209   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
210   *
211   * .. flat-table::
212   *   :widths: 1 10
213   *
214   *   * - %NETIF_F_SCTP_CRC
215   *     - This feature indicates that a device is capable of
216   *	 offloading the SCTP CRC in a packet. To perform this offload the stack
217   *	 will set csum_start and csum_offset accordingly, set ip_summed to
218   *	 %CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication
219   *	 in the skbuff that the %CHECKSUM_PARTIAL refers to CRC32c.
220   *	 A driver that supports both IP checksum offload and SCTP CRC32c offload
221   *	 must verify which offload is configured for a packet by testing the
222   *	 value of &sk_buff.csum_not_inet; skb_crc32c_csum_help() is provided to
223   *	 resolve %CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1.
224   *
225   *   * - %NETIF_F_FCOE_CRC
226   *     - This feature indicates that a device is capable of offloading the FCOE
227   *	 CRC in a packet. To perform this offload the stack will set ip_summed
228   *	 to %CHECKSUM_PARTIAL and set csum_start and csum_offset
229   *	 accordingly. Note that there is no indication in the skbuff that the
230   *	 %CHECKSUM_PARTIAL refers to an FCOE checksum, so a driver that supports
231   *	 both IP checksum offload and FCOE CRC offload must verify which offload
232   *	 is configured for a packet, presumably by inspecting packet headers.
233   *
234   * Checksumming on output with GSO
235   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
236   *
237   * In the case of a GSO packet (skb_is_gso() is true), checksum offload
238   * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
239   * gso_type is %SKB_GSO_TCPV4 or %SKB_GSO_TCPV6, TCP checksum offload as
240   * part of the GSO operation is implied. If a checksum is being offloaded
241   * with GSO then ip_summed is %CHECKSUM_PARTIAL, and both csum_start and
242   * csum_offset are set to refer to the outermost checksum being offloaded
243   * (two offloaded checksums are possible with UDP encapsulation).
244   */
245  
246  /* Don't change this without changing skb_csum_unnecessary! */
247  #define CHECKSUM_NONE		0
248  #define CHECKSUM_UNNECESSARY	1
249  #define CHECKSUM_COMPLETE	2
250  #define CHECKSUM_PARTIAL	3
251  
252  /* Maximum value in skb->csum_level */
253  #define SKB_MAX_CSUM_LEVEL	3
254  
255  #define SKB_DATA_ALIGN(X)	ALIGN(X, SMP_CACHE_BYTES)
256  #define SKB_WITH_OVERHEAD(X)	\
257  	((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
258  
259  /* For X bytes available in skb->head, what is the minimal
260   * allocation needed, knowing struct skb_shared_info needs
261   * to be aligned.
262   */
263  #define SKB_HEAD_ALIGN(X) (SKB_DATA_ALIGN(X) + \
264  	SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
265  
266  #define SKB_MAX_ORDER(X, ORDER) \
267  	SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
268  #define SKB_MAX_HEAD(X)		(SKB_MAX_ORDER((X), 0))
269  #define SKB_MAX_ALLOC		(SKB_MAX_ORDER(0, 2))
270  
271  /* return minimum truesize of one skb containing X bytes of data */
272  #define SKB_TRUESIZE(X) ((X) +						\
273  			 SKB_DATA_ALIGN(sizeof(struct sk_buff)) +	\
274  			 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
275  
276  struct ahash_request;
277  struct net_device;
278  struct scatterlist;
279  struct pipe_inode_info;
280  struct iov_iter;
281  struct napi_struct;
282  struct bpf_prog;
283  union bpf_attr;
284  struct skb_ext;
285  struct ts_config;
286  
287  #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
288  struct nf_bridge_info {
289  	enum {
290  		BRNF_PROTO_UNCHANGED,
291  		BRNF_PROTO_8021Q,
292  		BRNF_PROTO_PPPOE
293  	} orig_proto:8;
294  	u8			pkt_otherhost:1;
295  	u8			in_prerouting:1;
296  	u8			bridged_dnat:1;
297  	u8			sabotage_in_done:1;
298  	__u16			frag_max_size;
299  	int			physinif;
300  
301  	/* always valid & non-NULL from FORWARD on, for physdev match */
302  	struct net_device	*physoutdev;
303  	union {
304  		/* prerouting: detect dnat in orig/reply direction */
305  		__be32          ipv4_daddr;
306  		struct in6_addr ipv6_daddr;
307  
308  		/* after prerouting + nat detected: store original source
309  		 * mac since neigh resolution overwrites it, only used while
310  		 * skb is out in neigh layer.
311  		 */
312  		char neigh_header[8];
313  	};
314  };
315  #endif
316  
317  #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
318  /* Chain in tc_skb_ext will be used to share the tc chain with
319   * ovs recirc_id. It will be set to the current chain by tc
320   * and read by ovs to recirc_id.
321   */
322  struct tc_skb_ext {
323  	union {
324  		u64 act_miss_cookie;
325  		__u32 chain;
326  	};
327  	__u16 mru;
328  	__u16 zone;
329  	u8 post_ct:1;
330  	u8 post_ct_snat:1;
331  	u8 post_ct_dnat:1;
332  	u8 act_miss:1; /* Set if act_miss_cookie is used */
333  	u8 l2_miss:1; /* Set by bridge upon FDB or MDB miss */
334  };
335  #endif
336  
337  struct sk_buff_head {
338  	/* These two members must be first to match sk_buff. */
339  	struct_group_tagged(sk_buff_list, list,
340  		struct sk_buff	*next;
341  		struct sk_buff	*prev;
342  	);
343  
344  	__u32		qlen;
345  	spinlock_t	lock;
346  };
347  
348  struct sk_buff;
349  
350  #ifndef CONFIG_MAX_SKB_FRAGS
351  # define CONFIG_MAX_SKB_FRAGS 17
352  #endif
353  
354  #define MAX_SKB_FRAGS CONFIG_MAX_SKB_FRAGS
355  
356  /* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to
357   * segment using its current segmentation instead.
358   */
359  #define GSO_BY_FRAGS	0xFFFF
360  
361  typedef struct skb_frag {
362  	netmem_ref netmem;
363  	unsigned int len;
364  	unsigned int offset;
365  } skb_frag_t;
366  
367  /**
368   * skb_frag_size() - Returns the size of a skb fragment
369   * @frag: skb fragment
370   */
skb_frag_size(const skb_frag_t * frag)371  static inline unsigned int skb_frag_size(const skb_frag_t *frag)
372  {
373  	return frag->len;
374  }
375  
376  /**
377   * skb_frag_size_set() - Sets the size of a skb fragment
378   * @frag: skb fragment
379   * @size: size of fragment
380   */
skb_frag_size_set(skb_frag_t * frag,unsigned int size)381  static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
382  {
383  	frag->len = size;
384  }
385  
386  /**
387   * skb_frag_size_add() - Increments the size of a skb fragment by @delta
388   * @frag: skb fragment
389   * @delta: value to add
390   */
skb_frag_size_add(skb_frag_t * frag,int delta)391  static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
392  {
393  	frag->len += delta;
394  }
395  
396  /**
397   * skb_frag_size_sub() - Decrements the size of a skb fragment by @delta
398   * @frag: skb fragment
399   * @delta: value to subtract
400   */
skb_frag_size_sub(skb_frag_t * frag,int delta)401  static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
402  {
403  	frag->len -= delta;
404  }
405  
406  /**
407   * skb_frag_must_loop - Test if %p is a high memory page
408   * @p: fragment's page
409   */
skb_frag_must_loop(struct page * p)410  static inline bool skb_frag_must_loop(struct page *p)
411  {
412  #if defined(CONFIG_HIGHMEM)
413  	if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) || PageHighMem(p))
414  		return true;
415  #endif
416  	return false;
417  }
418  
419  /**
420   *	skb_frag_foreach_page - loop over pages in a fragment
421   *
422   *	@f:		skb frag to operate on
423   *	@f_off:		offset from start of f->netmem
424   *	@f_len:		length from f_off to loop over
425   *	@p:		(temp var) current page
426   *	@p_off:		(temp var) offset from start of current page,
427   *	                           non-zero only on first page.
428   *	@p_len:		(temp var) length in current page,
429   *				   < PAGE_SIZE only on first and last page.
430   *	@copied:	(temp var) length so far, excluding current p_len.
431   *
432   *	A fragment can hold a compound page, in which case per-page
433   *	operations, notably kmap_atomic, must be called for each
434   *	regular page.
435   */
436  #define skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied)	\
437  	for (p = skb_frag_page(f) + ((f_off) >> PAGE_SHIFT),		\
438  	     p_off = (f_off) & (PAGE_SIZE - 1),				\
439  	     p_len = skb_frag_must_loop(p) ?				\
440  	     min_t(u32, f_len, PAGE_SIZE - p_off) : f_len,		\
441  	     copied = 0;						\
442  	     copied < f_len;						\
443  	     copied += p_len, p++, p_off = 0,				\
444  	     p_len = min_t(u32, f_len - copied, PAGE_SIZE))		\
445  
446  /**
447   * struct skb_shared_hwtstamps - hardware time stamps
448   * @hwtstamp:		hardware time stamp transformed into duration
449   *			since arbitrary point in time
450   * @netdev_data:	address/cookie of network device driver used as
451   *			reference to actual hardware time stamp
452   *
453   * Software time stamps generated by ktime_get_real() are stored in
454   * skb->tstamp.
455   *
456   * hwtstamps can only be compared against other hwtstamps from
457   * the same device.
458   *
459   * This structure is attached to packets as part of the
460   * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
461   */
462  struct skb_shared_hwtstamps {
463  	union {
464  		ktime_t	hwtstamp;
465  		void *netdev_data;
466  	};
467  };
468  
469  /* Definitions for tx_flags in struct skb_shared_info */
470  enum {
471  	/* generate hardware time stamp */
472  	SKBTX_HW_TSTAMP = 1 << 0,
473  
474  	/* generate software time stamp when queueing packet to NIC */
475  	SKBTX_SW_TSTAMP = 1 << 1,
476  
477  	/* device driver is going to provide hardware time stamp */
478  	SKBTX_IN_PROGRESS = 1 << 2,
479  
480  	/* generate hardware time stamp based on cycles if supported */
481  	SKBTX_HW_TSTAMP_USE_CYCLES = 1 << 3,
482  
483  	/* generate wifi status information (where possible) */
484  	SKBTX_WIFI_STATUS = 1 << 4,
485  
486  	/* determine hardware time stamp based on time or cycles */
487  	SKBTX_HW_TSTAMP_NETDEV = 1 << 5,
488  
489  	/* generate software time stamp when entering packet scheduling */
490  	SKBTX_SCHED_TSTAMP = 1 << 6,
491  };
492  
493  #define SKBTX_ANY_SW_TSTAMP	(SKBTX_SW_TSTAMP    | \
494  				 SKBTX_SCHED_TSTAMP)
495  #define SKBTX_ANY_TSTAMP	(SKBTX_HW_TSTAMP | \
496  				 SKBTX_HW_TSTAMP_USE_CYCLES | \
497  				 SKBTX_ANY_SW_TSTAMP)
498  
499  /* Definitions for flags in struct skb_shared_info */
500  enum {
501  	/* use zcopy routines */
502  	SKBFL_ZEROCOPY_ENABLE = BIT(0),
503  
504  	/* This indicates at least one fragment might be overwritten
505  	 * (as in vmsplice(), sendfile() ...)
506  	 * If we need to compute a TX checksum, we'll need to copy
507  	 * all frags to avoid possible bad checksum
508  	 */
509  	SKBFL_SHARED_FRAG = BIT(1),
510  
511  	/* segment contains only zerocopy data and should not be
512  	 * charged to the kernel memory.
513  	 */
514  	SKBFL_PURE_ZEROCOPY = BIT(2),
515  
516  	SKBFL_DONT_ORPHAN = BIT(3),
517  
518  	/* page references are managed by the ubuf_info, so it's safe to
519  	 * use frags only up until ubuf_info is released
520  	 */
521  	SKBFL_MANAGED_FRAG_REFS = BIT(4),
522  };
523  
524  #define SKBFL_ZEROCOPY_FRAG	(SKBFL_ZEROCOPY_ENABLE | SKBFL_SHARED_FRAG)
525  #define SKBFL_ALL_ZEROCOPY	(SKBFL_ZEROCOPY_FRAG | SKBFL_PURE_ZEROCOPY | \
526  				 SKBFL_DONT_ORPHAN | SKBFL_MANAGED_FRAG_REFS)
527  
528  struct ubuf_info_ops {
529  	void (*complete)(struct sk_buff *, struct ubuf_info *,
530  			 bool zerocopy_success);
531  	/* has to be compatible with skb_zcopy_set() */
532  	int (*link_skb)(struct sk_buff *skb, struct ubuf_info *uarg);
533  };
534  
535  /*
536   * The callback notifies userspace to release buffers when skb DMA is done in
537   * lower device, the skb last reference should be 0 when calling this.
538   * The zerocopy_success argument is true if zero copy transmit occurred,
539   * false on data copy or out of memory error caused by data copy attempt.
540   * The ctx field is used to track device context.
541   * The desc field is used to track userspace buffer index.
542   */
543  struct ubuf_info {
544  	const struct ubuf_info_ops *ops;
545  	refcount_t refcnt;
546  	u8 flags;
547  };
548  
549  struct ubuf_info_msgzc {
550  	struct ubuf_info ubuf;
551  
552  	union {
553  		struct {
554  			unsigned long desc;
555  			void *ctx;
556  		};
557  		struct {
558  			u32 id;
559  			u16 len;
560  			u16 zerocopy:1;
561  			u32 bytelen;
562  		};
563  	};
564  
565  	struct mmpin {
566  		struct user_struct *user;
567  		unsigned int num_pg;
568  	} mmp;
569  };
570  
571  #define skb_uarg(SKB)	((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg))
572  #define uarg_to_msgzc(ubuf_ptr)	container_of((ubuf_ptr), struct ubuf_info_msgzc, \
573  					     ubuf)
574  
575  int mm_account_pinned_pages(struct mmpin *mmp, size_t size);
576  void mm_unaccount_pinned_pages(struct mmpin *mmp);
577  
578  /* Preserve some data across TX submission and completion.
579   *
580   * Note, this state is stored in the driver. Extending the layout
581   * might need some special care.
582   */
583  struct xsk_tx_metadata_compl {
584  	__u64 *tx_timestamp;
585  };
586  
587  /* This data is invariant across clones and lives at
588   * the end of the header data, ie. at skb->end.
589   */
590  struct skb_shared_info {
591  	__u8		flags;
592  	__u8		meta_len;
593  	__u8		nr_frags;
594  	__u8		tx_flags;
595  	unsigned short	gso_size;
596  	/* Warning: this field is not always filled in (UFO)! */
597  	unsigned short	gso_segs;
598  	struct sk_buff	*frag_list;
599  	union {
600  		struct skb_shared_hwtstamps hwtstamps;
601  		struct xsk_tx_metadata_compl xsk_meta;
602  	};
603  	unsigned int	gso_type;
604  	u32		tskey;
605  
606  	/*
607  	 * Warning : all fields before dataref are cleared in __alloc_skb()
608  	 */
609  	atomic_t	dataref;
610  	unsigned int	xdp_frags_size;
611  
612  	/* Intermediate layers must ensure that destructor_arg
613  	 * remains valid until skb destructor */
614  	void *		destructor_arg;
615  
616  	/* must be last field, see pskb_expand_head() */
617  	skb_frag_t	frags[MAX_SKB_FRAGS];
618  };
619  
620  /**
621   * DOC: dataref and headerless skbs
622   *
623   * Transport layers send out clones of payload skbs they hold for
624   * retransmissions. To allow lower layers of the stack to prepend their headers
625   * we split &skb_shared_info.dataref into two halves.
626   * The lower 16 bits count the overall number of references.
627   * The higher 16 bits indicate how many of the references are payload-only.
628   * skb_header_cloned() checks if skb is allowed to add / write the headers.
629   *
630   * The creator of the skb (e.g. TCP) marks its skb as &sk_buff.nohdr
631   * (via __skb_header_release()). Any clone created from marked skb will get
632   * &sk_buff.hdr_len populated with the available headroom.
633   * If there's the only clone in existence it's able to modify the headroom
634   * at will. The sequence of calls inside the transport layer is::
635   *
636   *  <alloc skb>
637   *  skb_reserve()
638   *  __skb_header_release()
639   *  skb_clone()
640   *  // send the clone down the stack
641   *
642   * This is not a very generic construct and it depends on the transport layers
643   * doing the right thing. In practice there's usually only one payload-only skb.
644   * Having multiple payload-only skbs with different lengths of hdr_len is not
645   * possible. The payload-only skbs should never leave their owner.
646   */
647  #define SKB_DATAREF_SHIFT 16
648  #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
649  
650  
651  enum {
652  	SKB_FCLONE_UNAVAILABLE,	/* skb has no fclone (from head_cache) */
653  	SKB_FCLONE_ORIG,	/* orig skb (from fclone_cache) */
654  	SKB_FCLONE_CLONE,	/* companion fclone skb (from fclone_cache) */
655  };
656  
657  enum {
658  	SKB_GSO_TCPV4 = 1 << 0,
659  
660  	/* This indicates the skb is from an untrusted source. */
661  	SKB_GSO_DODGY = 1 << 1,
662  
663  	/* This indicates the tcp segment has CWR set. */
664  	SKB_GSO_TCP_ECN = 1 << 2,
665  
666  	SKB_GSO_TCP_FIXEDID = 1 << 3,
667  
668  	SKB_GSO_TCPV6 = 1 << 4,
669  
670  	SKB_GSO_FCOE = 1 << 5,
671  
672  	SKB_GSO_GRE = 1 << 6,
673  
674  	SKB_GSO_GRE_CSUM = 1 << 7,
675  
676  	SKB_GSO_IPXIP4 = 1 << 8,
677  
678  	SKB_GSO_IPXIP6 = 1 << 9,
679  
680  	SKB_GSO_UDP_TUNNEL = 1 << 10,
681  
682  	SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
683  
684  	SKB_GSO_PARTIAL = 1 << 12,
685  
686  	SKB_GSO_TUNNEL_REMCSUM = 1 << 13,
687  
688  	SKB_GSO_SCTP = 1 << 14,
689  
690  	SKB_GSO_ESP = 1 << 15,
691  
692  	SKB_GSO_UDP = 1 << 16,
693  
694  	SKB_GSO_UDP_L4 = 1 << 17,
695  
696  	SKB_GSO_FRAGLIST = 1 << 18,
697  };
698  
699  #if BITS_PER_LONG > 32
700  #define NET_SKBUFF_DATA_USES_OFFSET 1
701  #endif
702  
703  #ifdef NET_SKBUFF_DATA_USES_OFFSET
704  typedef unsigned int sk_buff_data_t;
705  #else
706  typedef unsigned char *sk_buff_data_t;
707  #endif
708  
709  enum skb_tstamp_type {
710  	SKB_CLOCK_REALTIME,
711  	SKB_CLOCK_MONOTONIC,
712  	SKB_CLOCK_TAI,
713  	__SKB_CLOCK_MAX = SKB_CLOCK_TAI,
714  };
715  
716  /**
717   * DOC: Basic sk_buff geometry
718   *
719   * struct sk_buff itself is a metadata structure and does not hold any packet
720   * data. All the data is held in associated buffers.
721   *
722   * &sk_buff.head points to the main "head" buffer. The head buffer is divided
723   * into two parts:
724   *
725   *  - data buffer, containing headers and sometimes payload;
726   *    this is the part of the skb operated on by the common helpers
727   *    such as skb_put() or skb_pull();
728   *  - shared info (struct skb_shared_info) which holds an array of pointers
729   *    to read-only data in the (page, offset, length) format.
730   *
731   * Optionally &skb_shared_info.frag_list may point to another skb.
732   *
733   * Basic diagram may look like this::
734   *
735   *                                  ---------------
736   *                                 | sk_buff       |
737   *                                  ---------------
738   *     ,---------------------------  + head
739   *    /          ,-----------------  + data
740   *   /          /      ,-----------  + tail
741   *  |          |      |            , + end
742   *  |          |      |           |
743   *  v          v      v           v
744   *   -----------------------------------------------
745   *  | headroom | data |  tailroom | skb_shared_info |
746   *   -----------------------------------------------
747   *                                 + [page frag]
748   *                                 + [page frag]
749   *                                 + [page frag]
750   *                                 + [page frag]       ---------
751   *                                 + frag_list    --> | sk_buff |
752   *                                                     ---------
753   *
754   */
755  
756  /**
757   *	struct sk_buff - socket buffer
758   *	@next: Next buffer in list
759   *	@prev: Previous buffer in list
760   *	@tstamp: Time we arrived/left
761   *	@skb_mstamp_ns: (aka @tstamp) earliest departure time; start point
762   *		for retransmit timer
763   *	@rbnode: RB tree node, alternative to next/prev for netem/tcp
764   *	@list: queue head
765   *	@ll_node: anchor in an llist (eg socket defer_list)
766   *	@sk: Socket we are owned by
767   *	@dev: Device we arrived on/are leaving by
768   *	@dev_scratch: (aka @dev) alternate use of @dev when @dev would be %NULL
769   *	@cb: Control buffer. Free for use by every layer. Put private vars here
770   *	@_skb_refdst: destination entry (with norefcount bit)
771   *	@len: Length of actual data
772   *	@data_len: Data length
773   *	@mac_len: Length of link layer header
774   *	@hdr_len: writable header length of cloned skb
775   *	@csum: Checksum (must include start/offset pair)
776   *	@csum_start: Offset from skb->head where checksumming should start
777   *	@csum_offset: Offset from csum_start where checksum should be stored
778   *	@priority: Packet queueing priority
779   *	@ignore_df: allow local fragmentation
780   *	@cloned: Head may be cloned (check refcnt to be sure)
781   *	@ip_summed: Driver fed us an IP checksum
782   *	@nohdr: Payload reference only, must not modify header
783   *	@pkt_type: Packet class
784   *	@fclone: skbuff clone status
785   *	@ipvs_property: skbuff is owned by ipvs
786   *	@inner_protocol_type: whether the inner protocol is
787   *		ENCAP_TYPE_ETHER or ENCAP_TYPE_IPPROTO
788   *	@remcsum_offload: remote checksum offload is enabled
789   *	@offload_fwd_mark: Packet was L2-forwarded in hardware
790   *	@offload_l3_fwd_mark: Packet was L3-forwarded in hardware
791   *	@tc_skip_classify: do not classify packet. set by IFB device
792   *	@tc_at_ingress: used within tc_classify to distinguish in/egress
793   *	@redirected: packet was redirected by packet classifier
794   *	@from_ingress: packet was redirected from the ingress path
795   *	@nf_skip_egress: packet shall skip nf egress - see netfilter_netdev.h
796   *	@peeked: this packet has been seen already, so stats have been
797   *		done for it, don't do them again
798   *	@nf_trace: netfilter packet trace flag
799   *	@protocol: Packet protocol from driver
800   *	@destructor: Destruct function
801   *	@tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue)
802   *	@_sk_redir: socket redirection information for skmsg
803   *	@_nfct: Associated connection, if any (with nfctinfo bits)
804   *	@skb_iif: ifindex of device we arrived on
805   *	@tc_index: Traffic control index
806   *	@hash: the packet hash
807   *	@queue_mapping: Queue mapping for multiqueue devices
808   *	@head_frag: skb was allocated from page fragments,
809   *		not allocated by kmalloc() or vmalloc().
810   *	@pfmemalloc: skbuff was allocated from PFMEMALLOC reserves
811   *	@pp_recycle: mark the packet for recycling instead of freeing (implies
812   *		page_pool support on driver)
813   *	@active_extensions: active extensions (skb_ext_id types)
814   *	@ndisc_nodetype: router type (from link layer)
815   *	@ooo_okay: allow the mapping of a socket to a queue to be changed
816   *	@l4_hash: indicate hash is a canonical 4-tuple hash over transport
817   *		ports.
818   *	@sw_hash: indicates hash was computed in software stack
819   *	@wifi_acked_valid: wifi_acked was set
820   *	@wifi_acked: whether frame was acked on wifi or not
821   *	@no_fcs:  Request NIC to treat last 4 bytes as Ethernet FCS
822   *	@encapsulation: indicates the inner headers in the skbuff are valid
823   *	@encap_hdr_csum: software checksum is needed
824   *	@csum_valid: checksum is already valid
825   *	@csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL
826   *	@csum_complete_sw: checksum was completed by software
827   *	@csum_level: indicates the number of consecutive checksums found in
828   *		the packet minus one that have been verified as
829   *		CHECKSUM_UNNECESSARY (max 3)
830   *	@unreadable: indicates that at least 1 of the fragments in this skb is
831   *		unreadable.
832   *	@dst_pending_confirm: need to confirm neighbour
833   *	@decrypted: Decrypted SKB
834   *	@slow_gro: state present at GRO time, slower prepare step required
835   *	@tstamp_type: When set, skb->tstamp has the
836   *		delivery_time clock base of skb->tstamp.
837   *	@napi_id: id of the NAPI struct this skb came from
838   *	@sender_cpu: (aka @napi_id) source CPU in XPS
839   *	@alloc_cpu: CPU which did the skb allocation.
840   *	@secmark: security marking
841   *	@mark: Generic packet mark
842   *	@reserved_tailroom: (aka @mark) number of bytes of free space available
843   *		at the tail of an sk_buff
844   *	@vlan_all: vlan fields (proto & tci)
845   *	@vlan_proto: vlan encapsulation protocol
846   *	@vlan_tci: vlan tag control information
847   *	@inner_protocol: Protocol (encapsulation)
848   *	@inner_ipproto: (aka @inner_protocol) stores ipproto when
849   *		skb->inner_protocol_type == ENCAP_TYPE_IPPROTO;
850   *	@inner_transport_header: Inner transport layer header (encapsulation)
851   *	@inner_network_header: Network layer header (encapsulation)
852   *	@inner_mac_header: Link layer header (encapsulation)
853   *	@transport_header: Transport layer header
854   *	@network_header: Network layer header
855   *	@mac_header: Link layer header
856   *	@kcov_handle: KCOV remote handle for remote coverage collection
857   *	@tail: Tail pointer
858   *	@end: End pointer
859   *	@head: Head of buffer
860   *	@data: Data head pointer
861   *	@truesize: Buffer size
862   *	@users: User count - see {datagram,tcp}.c
863   *	@extensions: allocated extensions, valid if active_extensions is nonzero
864   */
865  
866  struct sk_buff {
867  	union {
868  		struct {
869  			/* These two members must be first to match sk_buff_head. */
870  			struct sk_buff		*next;
871  			struct sk_buff		*prev;
872  
873  			union {
874  				struct net_device	*dev;
875  				/* Some protocols might use this space to store information,
876  				 * while device pointer would be NULL.
877  				 * UDP receive path is one user.
878  				 */
879  				unsigned long		dev_scratch;
880  			};
881  		};
882  		struct rb_node		rbnode; /* used in netem, ip4 defrag, and tcp stack */
883  		struct list_head	list;
884  		struct llist_node	ll_node;
885  	};
886  
887  	struct sock		*sk;
888  
889  	union {
890  		ktime_t		tstamp;
891  		u64		skb_mstamp_ns; /* earliest departure time */
892  	};
893  	/*
894  	 * This is the control buffer. It is free to use for every
895  	 * layer. Please put your private variables there. If you
896  	 * want to keep them across layers you have to do a skb_clone()
897  	 * first. This is owned by whoever has the skb queued ATM.
898  	 */
899  	char			cb[48] __aligned(8);
900  
901  	union {
902  		struct {
903  			unsigned long	_skb_refdst;
904  			void		(*destructor)(struct sk_buff *skb);
905  		};
906  		struct list_head	tcp_tsorted_anchor;
907  #ifdef CONFIG_NET_SOCK_MSG
908  		unsigned long		_sk_redir;
909  #endif
910  	};
911  
912  #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
913  	unsigned long		 _nfct;
914  #endif
915  	unsigned int		len,
916  				data_len;
917  	__u16			mac_len,
918  				hdr_len;
919  
920  	/* Following fields are _not_ copied in __copy_skb_header()
921  	 * Note that queue_mapping is here mostly to fill a hole.
922  	 */
923  	__u16			queue_mapping;
924  
925  /* if you move cloned around you also must adapt those constants */
926  #ifdef __BIG_ENDIAN_BITFIELD
927  #define CLONED_MASK	(1 << 7)
928  #else
929  #define CLONED_MASK	1
930  #endif
931  #define CLONED_OFFSET		offsetof(struct sk_buff, __cloned_offset)
932  
933  	/* private: */
934  	__u8			__cloned_offset[0];
935  	/* public: */
936  	__u8			cloned:1,
937  				nohdr:1,
938  				fclone:2,
939  				peeked:1,
940  				head_frag:1,
941  				pfmemalloc:1,
942  				pp_recycle:1; /* page_pool recycle indicator */
943  #ifdef CONFIG_SKB_EXTENSIONS
944  	__u8			active_extensions;
945  #endif
946  
947  	/* Fields enclosed in headers group are copied
948  	 * using a single memcpy() in __copy_skb_header()
949  	 */
950  	struct_group(headers,
951  
952  	/* private: */
953  	__u8			__pkt_type_offset[0];
954  	/* public: */
955  	__u8			pkt_type:3; /* see PKT_TYPE_MAX */
956  	__u8			ignore_df:1;
957  	__u8			dst_pending_confirm:1;
958  	__u8			ip_summed:2;
959  	__u8			ooo_okay:1;
960  
961  	/* private: */
962  	__u8			__mono_tc_offset[0];
963  	/* public: */
964  	__u8			tstamp_type:2;	/* See skb_tstamp_type */
965  #ifdef CONFIG_NET_XGRESS
966  	__u8			tc_at_ingress:1;	/* See TC_AT_INGRESS_MASK */
967  	__u8			tc_skip_classify:1;
968  #endif
969  	__u8			remcsum_offload:1;
970  	__u8			csum_complete_sw:1;
971  	__u8			csum_level:2;
972  	__u8			inner_protocol_type:1;
973  
974  	__u8			l4_hash:1;
975  	__u8			sw_hash:1;
976  #ifdef CONFIG_WIRELESS
977  	__u8			wifi_acked_valid:1;
978  	__u8			wifi_acked:1;
979  #endif
980  	__u8			no_fcs:1;
981  	/* Indicates the inner headers are valid in the skbuff. */
982  	__u8			encapsulation:1;
983  	__u8			encap_hdr_csum:1;
984  	__u8			csum_valid:1;
985  #ifdef CONFIG_IPV6_NDISC_NODETYPE
986  	__u8			ndisc_nodetype:2;
987  #endif
988  
989  #if IS_ENABLED(CONFIG_IP_VS)
990  	__u8			ipvs_property:1;
991  #endif
992  #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES)
993  	__u8			nf_trace:1;
994  #endif
995  #ifdef CONFIG_NET_SWITCHDEV
996  	__u8			offload_fwd_mark:1;
997  	__u8			offload_l3_fwd_mark:1;
998  #endif
999  	__u8			redirected:1;
1000  #ifdef CONFIG_NET_REDIRECT
1001  	__u8			from_ingress:1;
1002  #endif
1003  #ifdef CONFIG_NETFILTER_SKIP_EGRESS
1004  	__u8			nf_skip_egress:1;
1005  #endif
1006  #ifdef CONFIG_SKB_DECRYPTED
1007  	__u8			decrypted:1;
1008  #endif
1009  	__u8			slow_gro:1;
1010  #if IS_ENABLED(CONFIG_IP_SCTP)
1011  	__u8			csum_not_inet:1;
1012  #endif
1013  	__u8			unreadable:1;
1014  #if defined(CONFIG_NET_SCHED) || defined(CONFIG_NET_XGRESS)
1015  	__u16			tc_index;	/* traffic control index */
1016  #endif
1017  
1018  	u16			alloc_cpu;
1019  
1020  	union {
1021  		__wsum		csum;
1022  		struct {
1023  			__u16	csum_start;
1024  			__u16	csum_offset;
1025  		};
1026  	};
1027  	__u32			priority;
1028  	int			skb_iif;
1029  	__u32			hash;
1030  	union {
1031  		u32		vlan_all;
1032  		struct {
1033  			__be16	vlan_proto;
1034  			__u16	vlan_tci;
1035  		};
1036  	};
1037  #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
1038  	union {
1039  		unsigned int	napi_id;
1040  		unsigned int	sender_cpu;
1041  	};
1042  #endif
1043  #ifdef CONFIG_NETWORK_SECMARK
1044  	__u32		secmark;
1045  #endif
1046  
1047  	union {
1048  		__u32		mark;
1049  		__u32		reserved_tailroom;
1050  	};
1051  
1052  	union {
1053  		__be16		inner_protocol;
1054  		__u8		inner_ipproto;
1055  	};
1056  
1057  	__u16			inner_transport_header;
1058  	__u16			inner_network_header;
1059  	__u16			inner_mac_header;
1060  
1061  	__be16			protocol;
1062  	__u16			transport_header;
1063  	__u16			network_header;
1064  	__u16			mac_header;
1065  
1066  #ifdef CONFIG_KCOV
1067  	u64			kcov_handle;
1068  #endif
1069  
1070  	); /* end headers group */
1071  
1072  	/* These elements must be at the end, see alloc_skb() for details.  */
1073  	sk_buff_data_t		tail;
1074  	sk_buff_data_t		end;
1075  	unsigned char		*head,
1076  				*data;
1077  	unsigned int		truesize;
1078  	refcount_t		users;
1079  
1080  #ifdef CONFIG_SKB_EXTENSIONS
1081  	/* only usable after checking ->active_extensions != 0 */
1082  	struct skb_ext		*extensions;
1083  #endif
1084  };
1085  
1086  /* if you move pkt_type around you also must adapt those constants */
1087  #ifdef __BIG_ENDIAN_BITFIELD
1088  #define PKT_TYPE_MAX	(7 << 5)
1089  #else
1090  #define PKT_TYPE_MAX	7
1091  #endif
1092  #define PKT_TYPE_OFFSET		offsetof(struct sk_buff, __pkt_type_offset)
1093  
1094  /* if you move tc_at_ingress or tstamp_type
1095   * around, you also must adapt these constants.
1096   */
1097  #ifdef __BIG_ENDIAN_BITFIELD
1098  #define SKB_TSTAMP_TYPE_MASK		(3 << 6)
1099  #define SKB_TSTAMP_TYPE_RSHIFT		(6)
1100  #define TC_AT_INGRESS_MASK		(1 << 5)
1101  #else
1102  #define SKB_TSTAMP_TYPE_MASK		(3)
1103  #define TC_AT_INGRESS_MASK		(1 << 2)
1104  #endif
1105  #define SKB_BF_MONO_TC_OFFSET		offsetof(struct sk_buff, __mono_tc_offset)
1106  
1107  #ifdef __KERNEL__
1108  /*
1109   *	Handling routines are only of interest to the kernel
1110   */
1111  
1112  #define SKB_ALLOC_FCLONE	0x01
1113  #define SKB_ALLOC_RX		0x02
1114  #define SKB_ALLOC_NAPI		0x04
1115  
1116  /**
1117   * skb_pfmemalloc - Test if the skb was allocated from PFMEMALLOC reserves
1118   * @skb: buffer
1119   */
skb_pfmemalloc(const struct sk_buff * skb)1120  static inline bool skb_pfmemalloc(const struct sk_buff *skb)
1121  {
1122  	return unlikely(skb->pfmemalloc);
1123  }
1124  
1125  /*
1126   * skb might have a dst pointer attached, refcounted or not.
1127   * _skb_refdst low order bit is set if refcount was _not_ taken
1128   */
1129  #define SKB_DST_NOREF	1UL
1130  #define SKB_DST_PTRMASK	~(SKB_DST_NOREF)
1131  
1132  /**
1133   * skb_dst - returns skb dst_entry
1134   * @skb: buffer
1135   *
1136   * Returns skb dst_entry, regardless of reference taken or not.
1137   */
skb_dst(const struct sk_buff * skb)1138  static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
1139  {
1140  	/* If refdst was not refcounted, check we still are in a
1141  	 * rcu_read_lock section
1142  	 */
1143  	WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
1144  		!rcu_read_lock_held() &&
1145  		!rcu_read_lock_bh_held());
1146  	return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
1147  }
1148  
1149  /**
1150   * skb_dst_set - sets skb dst
1151   * @skb: buffer
1152   * @dst: dst entry
1153   *
1154   * Sets skb dst, assuming a reference was taken on dst and should
1155   * be released by skb_dst_drop()
1156   */
skb_dst_set(struct sk_buff * skb,struct dst_entry * dst)1157  static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
1158  {
1159  	skb->slow_gro |= !!dst;
1160  	skb->_skb_refdst = (unsigned long)dst;
1161  }
1162  
1163  /**
1164   * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
1165   * @skb: buffer
1166   * @dst: dst entry
1167   *
1168   * Sets skb dst, assuming a reference was not taken on dst.
1169   * If dst entry is cached, we do not take reference and dst_release
1170   * will be avoided by refdst_drop. If dst entry is not cached, we take
1171   * reference, so that last dst_release can destroy the dst immediately.
1172   */
skb_dst_set_noref(struct sk_buff * skb,struct dst_entry * dst)1173  static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst)
1174  {
1175  	WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
1176  	skb->slow_gro |= !!dst;
1177  	skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF;
1178  }
1179  
1180  /**
1181   * skb_dst_is_noref - Test if skb dst isn't refcounted
1182   * @skb: buffer
1183   */
skb_dst_is_noref(const struct sk_buff * skb)1184  static inline bool skb_dst_is_noref(const struct sk_buff *skb)
1185  {
1186  	return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
1187  }
1188  
1189  /* For mangling skb->pkt_type from user space side from applications
1190   * such as nft, tc, etc, we only allow a conservative subset of
1191   * possible pkt_types to be set.
1192  */
skb_pkt_type_ok(u32 ptype)1193  static inline bool skb_pkt_type_ok(u32 ptype)
1194  {
1195  	return ptype <= PACKET_OTHERHOST;
1196  }
1197  
1198  /**
1199   * skb_napi_id - Returns the skb's NAPI id
1200   * @skb: buffer
1201   */
skb_napi_id(const struct sk_buff * skb)1202  static inline unsigned int skb_napi_id(const struct sk_buff *skb)
1203  {
1204  #ifdef CONFIG_NET_RX_BUSY_POLL
1205  	return skb->napi_id;
1206  #else
1207  	return 0;
1208  #endif
1209  }
1210  
skb_wifi_acked_valid(const struct sk_buff * skb)1211  static inline bool skb_wifi_acked_valid(const struct sk_buff *skb)
1212  {
1213  #ifdef CONFIG_WIRELESS
1214  	return skb->wifi_acked_valid;
1215  #else
1216  	return 0;
1217  #endif
1218  }
1219  
1220  /**
1221   * skb_unref - decrement the skb's reference count
1222   * @skb: buffer
1223   *
1224   * Returns true if we can free the skb.
1225   */
skb_unref(struct sk_buff * skb)1226  static inline bool skb_unref(struct sk_buff *skb)
1227  {
1228  	if (unlikely(!skb))
1229  		return false;
1230  	if (!IS_ENABLED(CONFIG_DEBUG_NET) && likely(refcount_read(&skb->users) == 1))
1231  		smp_rmb();
1232  	else if (likely(!refcount_dec_and_test(&skb->users)))
1233  		return false;
1234  
1235  	return true;
1236  }
1237  
skb_data_unref(const struct sk_buff * skb,struct skb_shared_info * shinfo)1238  static inline bool skb_data_unref(const struct sk_buff *skb,
1239  				  struct skb_shared_info *shinfo)
1240  {
1241  	int bias;
1242  
1243  	if (!skb->cloned)
1244  		return true;
1245  
1246  	bias = skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1;
1247  
1248  	if (atomic_read(&shinfo->dataref) == bias)
1249  		smp_rmb();
1250  	else if (atomic_sub_return(bias, &shinfo->dataref))
1251  		return false;
1252  
1253  	return true;
1254  }
1255  
1256  void __fix_address sk_skb_reason_drop(struct sock *sk, struct sk_buff *skb,
1257  				      enum skb_drop_reason reason);
1258  
1259  static inline void
kfree_skb_reason(struct sk_buff * skb,enum skb_drop_reason reason)1260  kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason)
1261  {
1262  	sk_skb_reason_drop(NULL, skb, reason);
1263  }
1264  
1265  /**
1266   *	kfree_skb - free an sk_buff with 'NOT_SPECIFIED' reason
1267   *	@skb: buffer to free
1268   */
kfree_skb(struct sk_buff * skb)1269  static inline void kfree_skb(struct sk_buff *skb)
1270  {
1271  	kfree_skb_reason(skb, SKB_DROP_REASON_NOT_SPECIFIED);
1272  }
1273  
1274  void skb_release_head_state(struct sk_buff *skb);
1275  void kfree_skb_list_reason(struct sk_buff *segs,
1276  			   enum skb_drop_reason reason);
1277  void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt);
1278  void skb_tx_error(struct sk_buff *skb);
1279  
kfree_skb_list(struct sk_buff * segs)1280  static inline void kfree_skb_list(struct sk_buff *segs)
1281  {
1282  	kfree_skb_list_reason(segs, SKB_DROP_REASON_NOT_SPECIFIED);
1283  }
1284  
1285  #ifdef CONFIG_TRACEPOINTS
1286  void consume_skb(struct sk_buff *skb);
1287  #else
consume_skb(struct sk_buff * skb)1288  static inline void consume_skb(struct sk_buff *skb)
1289  {
1290  	return kfree_skb(skb);
1291  }
1292  #endif
1293  
1294  void __consume_stateless_skb(struct sk_buff *skb);
1295  void  __kfree_skb(struct sk_buff *skb);
1296  
1297  void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
1298  bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
1299  		      bool *fragstolen, int *delta_truesize);
1300  
1301  struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags,
1302  			    int node);
1303  struct sk_buff *__build_skb(void *data, unsigned int frag_size);
1304  struct sk_buff *build_skb(void *data, unsigned int frag_size);
1305  struct sk_buff *build_skb_around(struct sk_buff *skb,
1306  				 void *data, unsigned int frag_size);
1307  void skb_attempt_defer_free(struct sk_buff *skb);
1308  
1309  struct sk_buff *napi_build_skb(void *data, unsigned int frag_size);
1310  struct sk_buff *slab_build_skb(void *data);
1311  
1312  /**
1313   * alloc_skb - allocate a network buffer
1314   * @size: size to allocate
1315   * @priority: allocation mask
1316   *
1317   * This function is a convenient wrapper around __alloc_skb().
1318   */
alloc_skb(unsigned int size,gfp_t priority)1319  static inline struct sk_buff *alloc_skb(unsigned int size,
1320  					gfp_t priority)
1321  {
1322  	return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
1323  }
1324  
1325  struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
1326  				     unsigned long data_len,
1327  				     int max_page_order,
1328  				     int *errcode,
1329  				     gfp_t gfp_mask);
1330  struct sk_buff *alloc_skb_for_msg(struct sk_buff *first);
1331  
1332  /* Layout of fast clones : [skb1][skb2][fclone_ref] */
1333  struct sk_buff_fclones {
1334  	struct sk_buff	skb1;
1335  
1336  	struct sk_buff	skb2;
1337  
1338  	refcount_t	fclone_ref;
1339  };
1340  
1341  /**
1342   *	skb_fclone_busy - check if fclone is busy
1343   *	@sk: socket
1344   *	@skb: buffer
1345   *
1346   * Returns true if skb is a fast clone, and its clone is not freed.
1347   * Some drivers call skb_orphan() in their ndo_start_xmit(),
1348   * so we also check that didn't happen.
1349   */
skb_fclone_busy(const struct sock * sk,const struct sk_buff * skb)1350  static inline bool skb_fclone_busy(const struct sock *sk,
1351  				   const struct sk_buff *skb)
1352  {
1353  	const struct sk_buff_fclones *fclones;
1354  
1355  	fclones = container_of(skb, struct sk_buff_fclones, skb1);
1356  
1357  	return skb->fclone == SKB_FCLONE_ORIG &&
1358  	       refcount_read(&fclones->fclone_ref) > 1 &&
1359  	       READ_ONCE(fclones->skb2.sk) == sk;
1360  }
1361  
1362  /**
1363   * alloc_skb_fclone - allocate a network buffer from fclone cache
1364   * @size: size to allocate
1365   * @priority: allocation mask
1366   *
1367   * This function is a convenient wrapper around __alloc_skb().
1368   */
alloc_skb_fclone(unsigned int size,gfp_t priority)1369  static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
1370  					       gfp_t priority)
1371  {
1372  	return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
1373  }
1374  
1375  struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
1376  void skb_headers_offset_update(struct sk_buff *skb, int off);
1377  int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
1378  struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority);
1379  void skb_copy_header(struct sk_buff *new, const struct sk_buff *old);
1380  struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority);
1381  struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
1382  				   gfp_t gfp_mask, bool fclone);
__pskb_copy(struct sk_buff * skb,int headroom,gfp_t gfp_mask)1383  static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom,
1384  					  gfp_t gfp_mask)
1385  {
1386  	return __pskb_copy_fclone(skb, headroom, gfp_mask, false);
1387  }
1388  
1389  int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask);
1390  struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
1391  				     unsigned int headroom);
1392  struct sk_buff *skb_expand_head(struct sk_buff *skb, unsigned int headroom);
1393  struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom,
1394  				int newtailroom, gfp_t priority);
1395  int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
1396  				     int offset, int len);
1397  int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg,
1398  			      int offset, int len);
1399  int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
1400  int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error);
1401  
1402  /**
1403   *	skb_pad			-	zero pad the tail of an skb
1404   *	@skb: buffer to pad
1405   *	@pad: space to pad
1406   *
1407   *	Ensure that a buffer is followed by a padding area that is zero
1408   *	filled. Used by network drivers which may DMA or transfer data
1409   *	beyond the buffer end onto the wire.
1410   *
1411   *	May return error in out of memory cases. The skb is freed on error.
1412   */
skb_pad(struct sk_buff * skb,int pad)1413  static inline int skb_pad(struct sk_buff *skb, int pad)
1414  {
1415  	return __skb_pad(skb, pad, true);
1416  }
1417  #define dev_kfree_skb(a)	consume_skb(a)
1418  
1419  int skb_append_pagefrags(struct sk_buff *skb, struct page *page,
1420  			 int offset, size_t size, size_t max_frags);
1421  
1422  struct skb_seq_state {
1423  	__u32		lower_offset;
1424  	__u32		upper_offset;
1425  	__u32		frag_idx;
1426  	__u32		stepped_offset;
1427  	struct sk_buff	*root_skb;
1428  	struct sk_buff	*cur_skb;
1429  	__u8		*frag_data;
1430  	__u32		frag_off;
1431  };
1432  
1433  void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
1434  			  unsigned int to, struct skb_seq_state *st);
1435  unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
1436  			  struct skb_seq_state *st);
1437  void skb_abort_seq_read(struct skb_seq_state *st);
1438  int skb_copy_seq_read(struct skb_seq_state *st, int offset, void *to, int len);
1439  
1440  unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
1441  			   unsigned int to, struct ts_config *config);
1442  
1443  /*
1444   * Packet hash types specify the type of hash in skb_set_hash.
1445   *
1446   * Hash types refer to the protocol layer addresses which are used to
1447   * construct a packet's hash. The hashes are used to differentiate or identify
1448   * flows of the protocol layer for the hash type. Hash types are either
1449   * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
1450   *
1451   * Properties of hashes:
1452   *
1453   * 1) Two packets in different flows have different hash values
1454   * 2) Two packets in the same flow should have the same hash value
1455   *
1456   * A hash at a higher layer is considered to be more specific. A driver should
1457   * set the most specific hash possible.
1458   *
1459   * A driver cannot indicate a more specific hash than the layer at which a hash
1460   * was computed. For instance an L3 hash cannot be set as an L4 hash.
1461   *
1462   * A driver may indicate a hash level which is less specific than the
1463   * actual layer the hash was computed on. For instance, a hash computed
1464   * at L4 may be considered an L3 hash. This should only be done if the
1465   * driver can't unambiguously determine that the HW computed the hash at
1466   * the higher layer. Note that the "should" in the second property above
1467   * permits this.
1468   */
1469  enum pkt_hash_types {
1470  	PKT_HASH_TYPE_NONE,	/* Undefined type */
1471  	PKT_HASH_TYPE_L2,	/* Input: src_MAC, dest_MAC */
1472  	PKT_HASH_TYPE_L3,	/* Input: src_IP, dst_IP */
1473  	PKT_HASH_TYPE_L4,	/* Input: src_IP, dst_IP, src_port, dst_port */
1474  };
1475  
skb_clear_hash(struct sk_buff * skb)1476  static inline void skb_clear_hash(struct sk_buff *skb)
1477  {
1478  	skb->hash = 0;
1479  	skb->sw_hash = 0;
1480  	skb->l4_hash = 0;
1481  }
1482  
skb_clear_hash_if_not_l4(struct sk_buff * skb)1483  static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
1484  {
1485  	if (!skb->l4_hash)
1486  		skb_clear_hash(skb);
1487  }
1488  
1489  static inline void
__skb_set_hash(struct sk_buff * skb,__u32 hash,bool is_sw,bool is_l4)1490  __skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4)
1491  {
1492  	skb->l4_hash = is_l4;
1493  	skb->sw_hash = is_sw;
1494  	skb->hash = hash;
1495  }
1496  
1497  static inline void
skb_set_hash(struct sk_buff * skb,__u32 hash,enum pkt_hash_types type)1498  skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
1499  {
1500  	/* Used by drivers to set hash from HW */
1501  	__skb_set_hash(skb, hash, false, type == PKT_HASH_TYPE_L4);
1502  }
1503  
1504  static inline void
__skb_set_sw_hash(struct sk_buff * skb,__u32 hash,bool is_l4)1505  __skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4)
1506  {
1507  	__skb_set_hash(skb, hash, true, is_l4);
1508  }
1509  
1510  u32 __skb_get_hash_symmetric_net(const struct net *net, const struct sk_buff *skb);
1511  
__skb_get_hash_symmetric(const struct sk_buff * skb)1512  static inline u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1513  {
1514  	return __skb_get_hash_symmetric_net(NULL, skb);
1515  }
1516  
1517  void __skb_get_hash_net(const struct net *net, struct sk_buff *skb);
1518  u32 skb_get_poff(const struct sk_buff *skb);
1519  u32 __skb_get_poff(const struct sk_buff *skb, const void *data,
1520  		   const struct flow_keys_basic *keys, int hlen);
1521  __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
1522  			    const void *data, int hlen_proto);
1523  
skb_flow_get_ports(const struct sk_buff * skb,int thoff,u8 ip_proto)1524  static inline __be32 skb_flow_get_ports(const struct sk_buff *skb,
1525  					int thoff, u8 ip_proto)
1526  {
1527  	return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, 0);
1528  }
1529  
1530  void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
1531  			     const struct flow_dissector_key *key,
1532  			     unsigned int key_count);
1533  
1534  struct bpf_flow_dissector;
1535  u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
1536  		     __be16 proto, int nhoff, int hlen, unsigned int flags);
1537  
1538  bool __skb_flow_dissect(const struct net *net,
1539  			const struct sk_buff *skb,
1540  			struct flow_dissector *flow_dissector,
1541  			void *target_container, const void *data,
1542  			__be16 proto, int nhoff, int hlen, unsigned int flags);
1543  
skb_flow_dissect(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,unsigned int flags)1544  static inline bool skb_flow_dissect(const struct sk_buff *skb,
1545  				    struct flow_dissector *flow_dissector,
1546  				    void *target_container, unsigned int flags)
1547  {
1548  	return __skb_flow_dissect(NULL, skb, flow_dissector,
1549  				  target_container, NULL, 0, 0, 0, flags);
1550  }
1551  
skb_flow_dissect_flow_keys(const struct sk_buff * skb,struct flow_keys * flow,unsigned int flags)1552  static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb,
1553  					      struct flow_keys *flow,
1554  					      unsigned int flags)
1555  {
1556  	memset(flow, 0, sizeof(*flow));
1557  	return __skb_flow_dissect(NULL, skb, &flow_keys_dissector,
1558  				  flow, NULL, 0, 0, 0, flags);
1559  }
1560  
1561  static inline bool
skb_flow_dissect_flow_keys_basic(const struct net * net,const struct sk_buff * skb,struct flow_keys_basic * flow,const void * data,__be16 proto,int nhoff,int hlen,unsigned int flags)1562  skb_flow_dissect_flow_keys_basic(const struct net *net,
1563  				 const struct sk_buff *skb,
1564  				 struct flow_keys_basic *flow,
1565  				 const void *data, __be16 proto,
1566  				 int nhoff, int hlen, unsigned int flags)
1567  {
1568  	memset(flow, 0, sizeof(*flow));
1569  	return __skb_flow_dissect(net, skb, &flow_keys_basic_dissector, flow,
1570  				  data, proto, nhoff, hlen, flags);
1571  }
1572  
1573  void skb_flow_dissect_meta(const struct sk_buff *skb,
1574  			   struct flow_dissector *flow_dissector,
1575  			   void *target_container);
1576  
1577  /* Gets a skb connection tracking info, ctinfo map should be a
1578   * map of mapsize to translate enum ip_conntrack_info states
1579   * to user states.
1580   */
1581  void
1582  skb_flow_dissect_ct(const struct sk_buff *skb,
1583  		    struct flow_dissector *flow_dissector,
1584  		    void *target_container,
1585  		    u16 *ctinfo_map, size_t mapsize,
1586  		    bool post_ct, u16 zone);
1587  void
1588  skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
1589  			     struct flow_dissector *flow_dissector,
1590  			     void *target_container);
1591  
1592  void skb_flow_dissect_hash(const struct sk_buff *skb,
1593  			   struct flow_dissector *flow_dissector,
1594  			   void *target_container);
1595  
skb_get_hash_net(const struct net * net,struct sk_buff * skb)1596  static inline __u32 skb_get_hash_net(const struct net *net, struct sk_buff *skb)
1597  {
1598  	if (!skb->l4_hash && !skb->sw_hash)
1599  		__skb_get_hash_net(net, skb);
1600  
1601  	return skb->hash;
1602  }
1603  
skb_get_hash(struct sk_buff * skb)1604  static inline __u32 skb_get_hash(struct sk_buff *skb)
1605  {
1606  	if (!skb->l4_hash && !skb->sw_hash)
1607  		__skb_get_hash_net(NULL, skb);
1608  
1609  	return skb->hash;
1610  }
1611  
skb_get_hash_flowi6(struct sk_buff * skb,const struct flowi6 * fl6)1612  static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
1613  {
1614  	if (!skb->l4_hash && !skb->sw_hash) {
1615  		struct flow_keys keys;
1616  		__u32 hash = __get_hash_from_flowi6(fl6, &keys);
1617  
1618  		__skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1619  	}
1620  
1621  	return skb->hash;
1622  }
1623  
1624  __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1625  			   const siphash_key_t *perturb);
1626  
skb_get_hash_raw(const struct sk_buff * skb)1627  static inline __u32 skb_get_hash_raw(const struct sk_buff *skb)
1628  {
1629  	return skb->hash;
1630  }
1631  
skb_copy_hash(struct sk_buff * to,const struct sk_buff * from)1632  static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
1633  {
1634  	to->hash = from->hash;
1635  	to->sw_hash = from->sw_hash;
1636  	to->l4_hash = from->l4_hash;
1637  };
1638  
skb_cmp_decrypted(const struct sk_buff * skb1,const struct sk_buff * skb2)1639  static inline int skb_cmp_decrypted(const struct sk_buff *skb1,
1640  				    const struct sk_buff *skb2)
1641  {
1642  #ifdef CONFIG_SKB_DECRYPTED
1643  	return skb2->decrypted - skb1->decrypted;
1644  #else
1645  	return 0;
1646  #endif
1647  }
1648  
skb_is_decrypted(const struct sk_buff * skb)1649  static inline bool skb_is_decrypted(const struct sk_buff *skb)
1650  {
1651  #ifdef CONFIG_SKB_DECRYPTED
1652  	return skb->decrypted;
1653  #else
1654  	return false;
1655  #endif
1656  }
1657  
skb_copy_decrypted(struct sk_buff * to,const struct sk_buff * from)1658  static inline void skb_copy_decrypted(struct sk_buff *to,
1659  				      const struct sk_buff *from)
1660  {
1661  #ifdef CONFIG_SKB_DECRYPTED
1662  	to->decrypted = from->decrypted;
1663  #endif
1664  }
1665  
1666  #ifdef NET_SKBUFF_DATA_USES_OFFSET
skb_end_pointer(const struct sk_buff * skb)1667  static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1668  {
1669  	return skb->head + skb->end;
1670  }
1671  
skb_end_offset(const struct sk_buff * skb)1672  static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1673  {
1674  	return skb->end;
1675  }
1676  
skb_set_end_offset(struct sk_buff * skb,unsigned int offset)1677  static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset)
1678  {
1679  	skb->end = offset;
1680  }
1681  #else
skb_end_pointer(const struct sk_buff * skb)1682  static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1683  {
1684  	return skb->end;
1685  }
1686  
skb_end_offset(const struct sk_buff * skb)1687  static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1688  {
1689  	return skb->end - skb->head;
1690  }
1691  
skb_set_end_offset(struct sk_buff * skb,unsigned int offset)1692  static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset)
1693  {
1694  	skb->end = skb->head + offset;
1695  }
1696  #endif
1697  
1698  extern const struct ubuf_info_ops msg_zerocopy_ubuf_ops;
1699  
1700  struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size,
1701  				       struct ubuf_info *uarg);
1702  
1703  void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref);
1704  
1705  int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk,
1706  			    struct sk_buff *skb, struct iov_iter *from,
1707  			    size_t length);
1708  
1709  int zerocopy_fill_skb_from_iter(struct sk_buff *skb,
1710  				struct iov_iter *from, size_t length);
1711  
skb_zerocopy_iter_dgram(struct sk_buff * skb,struct msghdr * msg,int len)1712  static inline int skb_zerocopy_iter_dgram(struct sk_buff *skb,
1713  					  struct msghdr *msg, int len)
1714  {
1715  	return __zerocopy_sg_from_iter(msg, skb->sk, skb, &msg->msg_iter, len);
1716  }
1717  
1718  int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
1719  			     struct msghdr *msg, int len,
1720  			     struct ubuf_info *uarg);
1721  
1722  /* Internal */
1723  #define skb_shinfo(SKB)	((struct skb_shared_info *)(skb_end_pointer(SKB)))
1724  
skb_hwtstamps(struct sk_buff * skb)1725  static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
1726  {
1727  	return &skb_shinfo(skb)->hwtstamps;
1728  }
1729  
skb_zcopy(struct sk_buff * skb)1730  static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb)
1731  {
1732  	bool is_zcopy = skb && skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE;
1733  
1734  	return is_zcopy ? skb_uarg(skb) : NULL;
1735  }
1736  
skb_zcopy_pure(const struct sk_buff * skb)1737  static inline bool skb_zcopy_pure(const struct sk_buff *skb)
1738  {
1739  	return skb_shinfo(skb)->flags & SKBFL_PURE_ZEROCOPY;
1740  }
1741  
skb_zcopy_managed(const struct sk_buff * skb)1742  static inline bool skb_zcopy_managed(const struct sk_buff *skb)
1743  {
1744  	return skb_shinfo(skb)->flags & SKBFL_MANAGED_FRAG_REFS;
1745  }
1746  
skb_pure_zcopy_same(const struct sk_buff * skb1,const struct sk_buff * skb2)1747  static inline bool skb_pure_zcopy_same(const struct sk_buff *skb1,
1748  				       const struct sk_buff *skb2)
1749  {
1750  	return skb_zcopy_pure(skb1) == skb_zcopy_pure(skb2);
1751  }
1752  
net_zcopy_get(struct ubuf_info * uarg)1753  static inline void net_zcopy_get(struct ubuf_info *uarg)
1754  {
1755  	refcount_inc(&uarg->refcnt);
1756  }
1757  
skb_zcopy_init(struct sk_buff * skb,struct ubuf_info * uarg)1758  static inline void skb_zcopy_init(struct sk_buff *skb, struct ubuf_info *uarg)
1759  {
1760  	skb_shinfo(skb)->destructor_arg = uarg;
1761  	skb_shinfo(skb)->flags |= uarg->flags;
1762  }
1763  
skb_zcopy_set(struct sk_buff * skb,struct ubuf_info * uarg,bool * have_ref)1764  static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg,
1765  				 bool *have_ref)
1766  {
1767  	if (skb && uarg && !skb_zcopy(skb)) {
1768  		if (unlikely(have_ref && *have_ref))
1769  			*have_ref = false;
1770  		else
1771  			net_zcopy_get(uarg);
1772  		skb_zcopy_init(skb, uarg);
1773  	}
1774  }
1775  
skb_zcopy_set_nouarg(struct sk_buff * skb,void * val)1776  static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val)
1777  {
1778  	skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL);
1779  	skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;
1780  }
1781  
skb_zcopy_is_nouarg(struct sk_buff * skb)1782  static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb)
1783  {
1784  	return (uintptr_t) skb_shinfo(skb)->destructor_arg & 0x1UL;
1785  }
1786  
skb_zcopy_get_nouarg(struct sk_buff * skb)1787  static inline void *skb_zcopy_get_nouarg(struct sk_buff *skb)
1788  {
1789  	return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~0x1UL);
1790  }
1791  
net_zcopy_put(struct ubuf_info * uarg)1792  static inline void net_zcopy_put(struct ubuf_info *uarg)
1793  {
1794  	if (uarg)
1795  		uarg->ops->complete(NULL, uarg, true);
1796  }
1797  
net_zcopy_put_abort(struct ubuf_info * uarg,bool have_uref)1798  static inline void net_zcopy_put_abort(struct ubuf_info *uarg, bool have_uref)
1799  {
1800  	if (uarg) {
1801  		if (uarg->ops == &msg_zerocopy_ubuf_ops)
1802  			msg_zerocopy_put_abort(uarg, have_uref);
1803  		else if (have_uref)
1804  			net_zcopy_put(uarg);
1805  	}
1806  }
1807  
1808  /* Release a reference on a zerocopy structure */
skb_zcopy_clear(struct sk_buff * skb,bool zerocopy_success)1809  static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success)
1810  {
1811  	struct ubuf_info *uarg = skb_zcopy(skb);
1812  
1813  	if (uarg) {
1814  		if (!skb_zcopy_is_nouarg(skb))
1815  			uarg->ops->complete(skb, uarg, zerocopy_success);
1816  
1817  		skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY;
1818  	}
1819  }
1820  
1821  void __skb_zcopy_downgrade_managed(struct sk_buff *skb);
1822  
skb_zcopy_downgrade_managed(struct sk_buff * skb)1823  static inline void skb_zcopy_downgrade_managed(struct sk_buff *skb)
1824  {
1825  	if (unlikely(skb_zcopy_managed(skb)))
1826  		__skb_zcopy_downgrade_managed(skb);
1827  }
1828  
1829  /* Return true if frags in this skb are readable by the host. */
skb_frags_readable(const struct sk_buff * skb)1830  static inline bool skb_frags_readable(const struct sk_buff *skb)
1831  {
1832  	return !skb->unreadable;
1833  }
1834  
skb_mark_not_on_list(struct sk_buff * skb)1835  static inline void skb_mark_not_on_list(struct sk_buff *skb)
1836  {
1837  	skb->next = NULL;
1838  }
1839  
skb_poison_list(struct sk_buff * skb)1840  static inline void skb_poison_list(struct sk_buff *skb)
1841  {
1842  #ifdef CONFIG_DEBUG_NET
1843  	skb->next = SKB_LIST_POISON_NEXT;
1844  #endif
1845  }
1846  
1847  /* Iterate through singly-linked GSO fragments of an skb. */
1848  #define skb_list_walk_safe(first, skb, next_skb)                               \
1849  	for ((skb) = (first), (next_skb) = (skb) ? (skb)->next : NULL; (skb);  \
1850  	     (skb) = (next_skb), (next_skb) = (skb) ? (skb)->next : NULL)
1851  
skb_list_del_init(struct sk_buff * skb)1852  static inline void skb_list_del_init(struct sk_buff *skb)
1853  {
1854  	__list_del_entry(&skb->list);
1855  	skb_mark_not_on_list(skb);
1856  }
1857  
1858  /**
1859   *	skb_queue_empty - check if a queue is empty
1860   *	@list: queue head
1861   *
1862   *	Returns true if the queue is empty, false otherwise.
1863   */
skb_queue_empty(const struct sk_buff_head * list)1864  static inline int skb_queue_empty(const struct sk_buff_head *list)
1865  {
1866  	return list->next == (const struct sk_buff *) list;
1867  }
1868  
1869  /**
1870   *	skb_queue_empty_lockless - check if a queue is empty
1871   *	@list: queue head
1872   *
1873   *	Returns true if the queue is empty, false otherwise.
1874   *	This variant can be used in lockless contexts.
1875   */
skb_queue_empty_lockless(const struct sk_buff_head * list)1876  static inline bool skb_queue_empty_lockless(const struct sk_buff_head *list)
1877  {
1878  	return READ_ONCE(list->next) == (const struct sk_buff *) list;
1879  }
1880  
1881  
1882  /**
1883   *	skb_queue_is_last - check if skb is the last entry in the queue
1884   *	@list: queue head
1885   *	@skb: buffer
1886   *
1887   *	Returns true if @skb is the last buffer on the list.
1888   */
skb_queue_is_last(const struct sk_buff_head * list,const struct sk_buff * skb)1889  static inline bool skb_queue_is_last(const struct sk_buff_head *list,
1890  				     const struct sk_buff *skb)
1891  {
1892  	return skb->next == (const struct sk_buff *) list;
1893  }
1894  
1895  /**
1896   *	skb_queue_is_first - check if skb is the first entry in the queue
1897   *	@list: queue head
1898   *	@skb: buffer
1899   *
1900   *	Returns true if @skb is the first buffer on the list.
1901   */
skb_queue_is_first(const struct sk_buff_head * list,const struct sk_buff * skb)1902  static inline bool skb_queue_is_first(const struct sk_buff_head *list,
1903  				      const struct sk_buff *skb)
1904  {
1905  	return skb->prev == (const struct sk_buff *) list;
1906  }
1907  
1908  /**
1909   *	skb_queue_next - return the next packet in the queue
1910   *	@list: queue head
1911   *	@skb: current buffer
1912   *
1913   *	Return the next packet in @list after @skb.  It is only valid to
1914   *	call this if skb_queue_is_last() evaluates to false.
1915   */
skb_queue_next(const struct sk_buff_head * list,const struct sk_buff * skb)1916  static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
1917  					     const struct sk_buff *skb)
1918  {
1919  	/* This BUG_ON may seem severe, but if we just return then we
1920  	 * are going to dereference garbage.
1921  	 */
1922  	BUG_ON(skb_queue_is_last(list, skb));
1923  	return skb->next;
1924  }
1925  
1926  /**
1927   *	skb_queue_prev - return the prev packet in the queue
1928   *	@list: queue head
1929   *	@skb: current buffer
1930   *
1931   *	Return the prev packet in @list before @skb.  It is only valid to
1932   *	call this if skb_queue_is_first() evaluates to false.
1933   */
skb_queue_prev(const struct sk_buff_head * list,const struct sk_buff * skb)1934  static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
1935  					     const struct sk_buff *skb)
1936  {
1937  	/* This BUG_ON may seem severe, but if we just return then we
1938  	 * are going to dereference garbage.
1939  	 */
1940  	BUG_ON(skb_queue_is_first(list, skb));
1941  	return skb->prev;
1942  }
1943  
1944  /**
1945   *	skb_get - reference buffer
1946   *	@skb: buffer to reference
1947   *
1948   *	Makes another reference to a socket buffer and returns a pointer
1949   *	to the buffer.
1950   */
skb_get(struct sk_buff * skb)1951  static inline struct sk_buff *skb_get(struct sk_buff *skb)
1952  {
1953  	refcount_inc(&skb->users);
1954  	return skb;
1955  }
1956  
1957  /*
1958   * If users == 1, we are the only owner and can avoid redundant atomic changes.
1959   */
1960  
1961  /**
1962   *	skb_cloned - is the buffer a clone
1963   *	@skb: buffer to check
1964   *
1965   *	Returns true if the buffer was generated with skb_clone() and is
1966   *	one of multiple shared copies of the buffer. Cloned buffers are
1967   *	shared data so must not be written to under normal circumstances.
1968   */
skb_cloned(const struct sk_buff * skb)1969  static inline int skb_cloned(const struct sk_buff *skb)
1970  {
1971  	return skb->cloned &&
1972  	       (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
1973  }
1974  
skb_unclone(struct sk_buff * skb,gfp_t pri)1975  static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
1976  {
1977  	might_sleep_if(gfpflags_allow_blocking(pri));
1978  
1979  	if (skb_cloned(skb))
1980  		return pskb_expand_head(skb, 0, 0, pri);
1981  
1982  	return 0;
1983  }
1984  
1985  /* This variant of skb_unclone() makes sure skb->truesize
1986   * and skb_end_offset() are not changed, whenever a new skb->head is needed.
1987   *
1988   * Indeed there is no guarantee that ksize(kmalloc(X)) == ksize(kmalloc(X))
1989   * when various debugging features are in place.
1990   */
1991  int __skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri);
skb_unclone_keeptruesize(struct sk_buff * skb,gfp_t pri)1992  static inline int skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri)
1993  {
1994  	might_sleep_if(gfpflags_allow_blocking(pri));
1995  
1996  	if (skb_cloned(skb))
1997  		return __skb_unclone_keeptruesize(skb, pri);
1998  	return 0;
1999  }
2000  
2001  /**
2002   *	skb_header_cloned - is the header a clone
2003   *	@skb: buffer to check
2004   *
2005   *	Returns true if modifying the header part of the buffer requires
2006   *	the data to be copied.
2007   */
skb_header_cloned(const struct sk_buff * skb)2008  static inline int skb_header_cloned(const struct sk_buff *skb)
2009  {
2010  	int dataref;
2011  
2012  	if (!skb->cloned)
2013  		return 0;
2014  
2015  	dataref = atomic_read(&skb_shinfo(skb)->dataref);
2016  	dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
2017  	return dataref != 1;
2018  }
2019  
skb_header_unclone(struct sk_buff * skb,gfp_t pri)2020  static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri)
2021  {
2022  	might_sleep_if(gfpflags_allow_blocking(pri));
2023  
2024  	if (skb_header_cloned(skb))
2025  		return pskb_expand_head(skb, 0, 0, pri);
2026  
2027  	return 0;
2028  }
2029  
2030  /**
2031   * __skb_header_release() - allow clones to use the headroom
2032   * @skb: buffer to operate on
2033   *
2034   * See "DOC: dataref and headerless skbs".
2035   */
__skb_header_release(struct sk_buff * skb)2036  static inline void __skb_header_release(struct sk_buff *skb)
2037  {
2038  	skb->nohdr = 1;
2039  	atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT));
2040  }
2041  
2042  
2043  /**
2044   *	skb_shared - is the buffer shared
2045   *	@skb: buffer to check
2046   *
2047   *	Returns true if more than one person has a reference to this
2048   *	buffer.
2049   */
skb_shared(const struct sk_buff * skb)2050  static inline int skb_shared(const struct sk_buff *skb)
2051  {
2052  	return refcount_read(&skb->users) != 1;
2053  }
2054  
2055  /**
2056   *	skb_share_check - check if buffer is shared and if so clone it
2057   *	@skb: buffer to check
2058   *	@pri: priority for memory allocation
2059   *
2060   *	If the buffer is shared the buffer is cloned and the old copy
2061   *	drops a reference. A new clone with a single reference is returned.
2062   *	If the buffer is not shared the original buffer is returned. When
2063   *	being called from interrupt status or with spinlocks held pri must
2064   *	be GFP_ATOMIC.
2065   *
2066   *	NULL is returned on a memory allocation failure.
2067   */
skb_share_check(struct sk_buff * skb,gfp_t pri)2068  static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
2069  {
2070  	might_sleep_if(gfpflags_allow_blocking(pri));
2071  	if (skb_shared(skb)) {
2072  		struct sk_buff *nskb = skb_clone(skb, pri);
2073  
2074  		if (likely(nskb))
2075  			consume_skb(skb);
2076  		else
2077  			kfree_skb(skb);
2078  		skb = nskb;
2079  	}
2080  	return skb;
2081  }
2082  
2083  /*
2084   *	Copy shared buffers into a new sk_buff. We effectively do COW on
2085   *	packets to handle cases where we have a local reader and forward
2086   *	and a couple of other messy ones. The normal one is tcpdumping
2087   *	a packet that's being forwarded.
2088   */
2089  
2090  /**
2091   *	skb_unshare - make a copy of a shared buffer
2092   *	@skb: buffer to check
2093   *	@pri: priority for memory allocation
2094   *
2095   *	If the socket buffer is a clone then this function creates a new
2096   *	copy of the data, drops a reference count on the old copy and returns
2097   *	the new copy with the reference count at 1. If the buffer is not a clone
2098   *	the original buffer is returned. When called with a spinlock held or
2099   *	from interrupt state @pri must be %GFP_ATOMIC
2100   *
2101   *	%NULL is returned on a memory allocation failure.
2102   */
skb_unshare(struct sk_buff * skb,gfp_t pri)2103  static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
2104  					  gfp_t pri)
2105  {
2106  	might_sleep_if(gfpflags_allow_blocking(pri));
2107  	if (skb_cloned(skb)) {
2108  		struct sk_buff *nskb = skb_copy(skb, pri);
2109  
2110  		/* Free our shared copy */
2111  		if (likely(nskb))
2112  			consume_skb(skb);
2113  		else
2114  			kfree_skb(skb);
2115  		skb = nskb;
2116  	}
2117  	return skb;
2118  }
2119  
2120  /**
2121   *	skb_peek - peek at the head of an &sk_buff_head
2122   *	@list_: list to peek at
2123   *
2124   *	Peek an &sk_buff. Unlike most other operations you _MUST_
2125   *	be careful with this one. A peek leaves the buffer on the
2126   *	list and someone else may run off with it. You must hold
2127   *	the appropriate locks or have a private queue to do this.
2128   *
2129   *	Returns %NULL for an empty list or a pointer to the head element.
2130   *	The reference count is not incremented and the reference is therefore
2131   *	volatile. Use with caution.
2132   */
skb_peek(const struct sk_buff_head * list_)2133  static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
2134  {
2135  	struct sk_buff *skb = list_->next;
2136  
2137  	if (skb == (struct sk_buff *)list_)
2138  		skb = NULL;
2139  	return skb;
2140  }
2141  
2142  /**
2143   *	__skb_peek - peek at the head of a non-empty &sk_buff_head
2144   *	@list_: list to peek at
2145   *
2146   *	Like skb_peek(), but the caller knows that the list is not empty.
2147   */
__skb_peek(const struct sk_buff_head * list_)2148  static inline struct sk_buff *__skb_peek(const struct sk_buff_head *list_)
2149  {
2150  	return list_->next;
2151  }
2152  
2153  /**
2154   *	skb_peek_next - peek skb following the given one from a queue
2155   *	@skb: skb to start from
2156   *	@list_: list to peek at
2157   *
2158   *	Returns %NULL when the end of the list is met or a pointer to the
2159   *	next element. The reference count is not incremented and the
2160   *	reference is therefore volatile. Use with caution.
2161   */
skb_peek_next(struct sk_buff * skb,const struct sk_buff_head * list_)2162  static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
2163  		const struct sk_buff_head *list_)
2164  {
2165  	struct sk_buff *next = skb->next;
2166  
2167  	if (next == (struct sk_buff *)list_)
2168  		next = NULL;
2169  	return next;
2170  }
2171  
2172  /**
2173   *	skb_peek_tail - peek at the tail of an &sk_buff_head
2174   *	@list_: list to peek at
2175   *
2176   *	Peek an &sk_buff. Unlike most other operations you _MUST_
2177   *	be careful with this one. A peek leaves the buffer on the
2178   *	list and someone else may run off with it. You must hold
2179   *	the appropriate locks or have a private queue to do this.
2180   *
2181   *	Returns %NULL for an empty list or a pointer to the tail element.
2182   *	The reference count is not incremented and the reference is therefore
2183   *	volatile. Use with caution.
2184   */
skb_peek_tail(const struct sk_buff_head * list_)2185  static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
2186  {
2187  	struct sk_buff *skb = READ_ONCE(list_->prev);
2188  
2189  	if (skb == (struct sk_buff *)list_)
2190  		skb = NULL;
2191  	return skb;
2192  
2193  }
2194  
2195  /**
2196   *	skb_queue_len	- get queue length
2197   *	@list_: list to measure
2198   *
2199   *	Return the length of an &sk_buff queue.
2200   */
skb_queue_len(const struct sk_buff_head * list_)2201  static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
2202  {
2203  	return list_->qlen;
2204  }
2205  
2206  /**
2207   *	skb_queue_len_lockless	- get queue length
2208   *	@list_: list to measure
2209   *
2210   *	Return the length of an &sk_buff queue.
2211   *	This variant can be used in lockless contexts.
2212   */
skb_queue_len_lockless(const struct sk_buff_head * list_)2213  static inline __u32 skb_queue_len_lockless(const struct sk_buff_head *list_)
2214  {
2215  	return READ_ONCE(list_->qlen);
2216  }
2217  
2218  /**
2219   *	__skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
2220   *	@list: queue to initialize
2221   *
2222   *	This initializes only the list and queue length aspects of
2223   *	an sk_buff_head object.  This allows to initialize the list
2224   *	aspects of an sk_buff_head without reinitializing things like
2225   *	the spinlock.  It can also be used for on-stack sk_buff_head
2226   *	objects where the spinlock is known to not be used.
2227   */
__skb_queue_head_init(struct sk_buff_head * list)2228  static inline void __skb_queue_head_init(struct sk_buff_head *list)
2229  {
2230  	list->prev = list->next = (struct sk_buff *)list;
2231  	list->qlen = 0;
2232  }
2233  
2234  /*
2235   * This function creates a split out lock class for each invocation;
2236   * this is needed for now since a whole lot of users of the skb-queue
2237   * infrastructure in drivers have different locking usage (in hardirq)
2238   * than the networking core (in softirq only). In the long run either the
2239   * network layer or drivers should need annotation to consolidate the
2240   * main types of usage into 3 classes.
2241   */
skb_queue_head_init(struct sk_buff_head * list)2242  static inline void skb_queue_head_init(struct sk_buff_head *list)
2243  {
2244  	spin_lock_init(&list->lock);
2245  	__skb_queue_head_init(list);
2246  }
2247  
skb_queue_head_init_class(struct sk_buff_head * list,struct lock_class_key * class)2248  static inline void skb_queue_head_init_class(struct sk_buff_head *list,
2249  		struct lock_class_key *class)
2250  {
2251  	skb_queue_head_init(list);
2252  	lockdep_set_class(&list->lock, class);
2253  }
2254  
2255  /*
2256   *	Insert an sk_buff on a list.
2257   *
2258   *	The "__skb_xxxx()" functions are the non-atomic ones that
2259   *	can only be called with interrupts disabled.
2260   */
__skb_insert(struct sk_buff * newsk,struct sk_buff * prev,struct sk_buff * next,struct sk_buff_head * list)2261  static inline void __skb_insert(struct sk_buff *newsk,
2262  				struct sk_buff *prev, struct sk_buff *next,
2263  				struct sk_buff_head *list)
2264  {
2265  	/* See skb_queue_empty_lockless() and skb_peek_tail()
2266  	 * for the opposite READ_ONCE()
2267  	 */
2268  	WRITE_ONCE(newsk->next, next);
2269  	WRITE_ONCE(newsk->prev, prev);
2270  	WRITE_ONCE(((struct sk_buff_list *)next)->prev, newsk);
2271  	WRITE_ONCE(((struct sk_buff_list *)prev)->next, newsk);
2272  	WRITE_ONCE(list->qlen, list->qlen + 1);
2273  }
2274  
__skb_queue_splice(const struct sk_buff_head * list,struct sk_buff * prev,struct sk_buff * next)2275  static inline void __skb_queue_splice(const struct sk_buff_head *list,
2276  				      struct sk_buff *prev,
2277  				      struct sk_buff *next)
2278  {
2279  	struct sk_buff *first = list->next;
2280  	struct sk_buff *last = list->prev;
2281  
2282  	WRITE_ONCE(first->prev, prev);
2283  	WRITE_ONCE(prev->next, first);
2284  
2285  	WRITE_ONCE(last->next, next);
2286  	WRITE_ONCE(next->prev, last);
2287  }
2288  
2289  /**
2290   *	skb_queue_splice - join two skb lists, this is designed for stacks
2291   *	@list: the new list to add
2292   *	@head: the place to add it in the first list
2293   */
skb_queue_splice(const struct sk_buff_head * list,struct sk_buff_head * head)2294  static inline void skb_queue_splice(const struct sk_buff_head *list,
2295  				    struct sk_buff_head *head)
2296  {
2297  	if (!skb_queue_empty(list)) {
2298  		__skb_queue_splice(list, (struct sk_buff *) head, head->next);
2299  		head->qlen += list->qlen;
2300  	}
2301  }
2302  
2303  /**
2304   *	skb_queue_splice_init - join two skb lists and reinitialise the emptied list
2305   *	@list: the new list to add
2306   *	@head: the place to add it in the first list
2307   *
2308   *	The list at @list is reinitialised
2309   */
skb_queue_splice_init(struct sk_buff_head * list,struct sk_buff_head * head)2310  static inline void skb_queue_splice_init(struct sk_buff_head *list,
2311  					 struct sk_buff_head *head)
2312  {
2313  	if (!skb_queue_empty(list)) {
2314  		__skb_queue_splice(list, (struct sk_buff *) head, head->next);
2315  		head->qlen += list->qlen;
2316  		__skb_queue_head_init(list);
2317  	}
2318  }
2319  
2320  /**
2321   *	skb_queue_splice_tail - join two skb lists, each list being a queue
2322   *	@list: the new list to add
2323   *	@head: the place to add it in the first list
2324   */
skb_queue_splice_tail(const struct sk_buff_head * list,struct sk_buff_head * head)2325  static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
2326  					 struct sk_buff_head *head)
2327  {
2328  	if (!skb_queue_empty(list)) {
2329  		__skb_queue_splice(list, head->prev, (struct sk_buff *) head);
2330  		head->qlen += list->qlen;
2331  	}
2332  }
2333  
2334  /**
2335   *	skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
2336   *	@list: the new list to add
2337   *	@head: the place to add it in the first list
2338   *
2339   *	Each of the lists is a queue.
2340   *	The list at @list is reinitialised
2341   */
skb_queue_splice_tail_init(struct sk_buff_head * list,struct sk_buff_head * head)2342  static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
2343  					      struct sk_buff_head *head)
2344  {
2345  	if (!skb_queue_empty(list)) {
2346  		__skb_queue_splice(list, head->prev, (struct sk_buff *) head);
2347  		head->qlen += list->qlen;
2348  		__skb_queue_head_init(list);
2349  	}
2350  }
2351  
2352  /**
2353   *	__skb_queue_after - queue a buffer at the list head
2354   *	@list: list to use
2355   *	@prev: place after this buffer
2356   *	@newsk: buffer to queue
2357   *
2358   *	Queue a buffer int the middle of a list. This function takes no locks
2359   *	and you must therefore hold required locks before calling it.
2360   *
2361   *	A buffer cannot be placed on two lists at the same time.
2362   */
__skb_queue_after(struct sk_buff_head * list,struct sk_buff * prev,struct sk_buff * newsk)2363  static inline void __skb_queue_after(struct sk_buff_head *list,
2364  				     struct sk_buff *prev,
2365  				     struct sk_buff *newsk)
2366  {
2367  	__skb_insert(newsk, prev, ((struct sk_buff_list *)prev)->next, list);
2368  }
2369  
2370  void skb_append(struct sk_buff *old, struct sk_buff *newsk,
2371  		struct sk_buff_head *list);
2372  
__skb_queue_before(struct sk_buff_head * list,struct sk_buff * next,struct sk_buff * newsk)2373  static inline void __skb_queue_before(struct sk_buff_head *list,
2374  				      struct sk_buff *next,
2375  				      struct sk_buff *newsk)
2376  {
2377  	__skb_insert(newsk, ((struct sk_buff_list *)next)->prev, next, list);
2378  }
2379  
2380  /**
2381   *	__skb_queue_head - queue a buffer at the list head
2382   *	@list: list to use
2383   *	@newsk: buffer to queue
2384   *
2385   *	Queue a buffer at the start of a list. This function takes no locks
2386   *	and you must therefore hold required locks before calling it.
2387   *
2388   *	A buffer cannot be placed on two lists at the same time.
2389   */
__skb_queue_head(struct sk_buff_head * list,struct sk_buff * newsk)2390  static inline void __skb_queue_head(struct sk_buff_head *list,
2391  				    struct sk_buff *newsk)
2392  {
2393  	__skb_queue_after(list, (struct sk_buff *)list, newsk);
2394  }
2395  void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
2396  
2397  /**
2398   *	__skb_queue_tail - queue a buffer at the list tail
2399   *	@list: list to use
2400   *	@newsk: buffer to queue
2401   *
2402   *	Queue a buffer at the end of a list. This function takes no locks
2403   *	and you must therefore hold required locks before calling it.
2404   *
2405   *	A buffer cannot be placed on two lists at the same time.
2406   */
__skb_queue_tail(struct sk_buff_head * list,struct sk_buff * newsk)2407  static inline void __skb_queue_tail(struct sk_buff_head *list,
2408  				   struct sk_buff *newsk)
2409  {
2410  	__skb_queue_before(list, (struct sk_buff *)list, newsk);
2411  }
2412  void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
2413  
2414  /*
2415   * remove sk_buff from list. _Must_ be called atomically, and with
2416   * the list known..
2417   */
2418  void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
__skb_unlink(struct sk_buff * skb,struct sk_buff_head * list)2419  static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
2420  {
2421  	struct sk_buff *next, *prev;
2422  
2423  	WRITE_ONCE(list->qlen, list->qlen - 1);
2424  	next	   = skb->next;
2425  	prev	   = skb->prev;
2426  	skb->next  = skb->prev = NULL;
2427  	WRITE_ONCE(next->prev, prev);
2428  	WRITE_ONCE(prev->next, next);
2429  }
2430  
2431  /**
2432   *	__skb_dequeue - remove from the head of the queue
2433   *	@list: list to dequeue from
2434   *
2435   *	Remove the head of the list. This function does not take any locks
2436   *	so must be used with appropriate locks held only. The head item is
2437   *	returned or %NULL if the list is empty.
2438   */
__skb_dequeue(struct sk_buff_head * list)2439  static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
2440  {
2441  	struct sk_buff *skb = skb_peek(list);
2442  	if (skb)
2443  		__skb_unlink(skb, list);
2444  	return skb;
2445  }
2446  struct sk_buff *skb_dequeue(struct sk_buff_head *list);
2447  
2448  /**
2449   *	__skb_dequeue_tail - remove from the tail of the queue
2450   *	@list: list to dequeue from
2451   *
2452   *	Remove the tail of the list. This function does not take any locks
2453   *	so must be used with appropriate locks held only. The tail item is
2454   *	returned or %NULL if the list is empty.
2455   */
__skb_dequeue_tail(struct sk_buff_head * list)2456  static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
2457  {
2458  	struct sk_buff *skb = skb_peek_tail(list);
2459  	if (skb)
2460  		__skb_unlink(skb, list);
2461  	return skb;
2462  }
2463  struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
2464  
2465  
skb_is_nonlinear(const struct sk_buff * skb)2466  static inline bool skb_is_nonlinear(const struct sk_buff *skb)
2467  {
2468  	return skb->data_len;
2469  }
2470  
skb_headlen(const struct sk_buff * skb)2471  static inline unsigned int skb_headlen(const struct sk_buff *skb)
2472  {
2473  	return skb->len - skb->data_len;
2474  }
2475  
__skb_pagelen(const struct sk_buff * skb)2476  static inline unsigned int __skb_pagelen(const struct sk_buff *skb)
2477  {
2478  	unsigned int i, len = 0;
2479  
2480  	for (i = skb_shinfo(skb)->nr_frags - 1; (int)i >= 0; i--)
2481  		len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
2482  	return len;
2483  }
2484  
skb_pagelen(const struct sk_buff * skb)2485  static inline unsigned int skb_pagelen(const struct sk_buff *skb)
2486  {
2487  	return skb_headlen(skb) + __skb_pagelen(skb);
2488  }
2489  
skb_frag_fill_netmem_desc(skb_frag_t * frag,netmem_ref netmem,int off,int size)2490  static inline void skb_frag_fill_netmem_desc(skb_frag_t *frag,
2491  					     netmem_ref netmem, int off,
2492  					     int size)
2493  {
2494  	frag->netmem = netmem;
2495  	frag->offset = off;
2496  	skb_frag_size_set(frag, size);
2497  }
2498  
skb_frag_fill_page_desc(skb_frag_t * frag,struct page * page,int off,int size)2499  static inline void skb_frag_fill_page_desc(skb_frag_t *frag,
2500  					   struct page *page,
2501  					   int off, int size)
2502  {
2503  	skb_frag_fill_netmem_desc(frag, page_to_netmem(page), off, size);
2504  }
2505  
__skb_fill_netmem_desc_noacc(struct skb_shared_info * shinfo,int i,netmem_ref netmem,int off,int size)2506  static inline void __skb_fill_netmem_desc_noacc(struct skb_shared_info *shinfo,
2507  						int i, netmem_ref netmem,
2508  						int off, int size)
2509  {
2510  	skb_frag_t *frag = &shinfo->frags[i];
2511  
2512  	skb_frag_fill_netmem_desc(frag, netmem, off, size);
2513  }
2514  
__skb_fill_page_desc_noacc(struct skb_shared_info * shinfo,int i,struct page * page,int off,int size)2515  static inline void __skb_fill_page_desc_noacc(struct skb_shared_info *shinfo,
2516  					      int i, struct page *page,
2517  					      int off, int size)
2518  {
2519  	__skb_fill_netmem_desc_noacc(shinfo, i, page_to_netmem(page), off,
2520  				     size);
2521  }
2522  
2523  /**
2524   * skb_len_add - adds a number to len fields of skb
2525   * @skb: buffer to add len to
2526   * @delta: number of bytes to add
2527   */
skb_len_add(struct sk_buff * skb,int delta)2528  static inline void skb_len_add(struct sk_buff *skb, int delta)
2529  {
2530  	skb->len += delta;
2531  	skb->data_len += delta;
2532  	skb->truesize += delta;
2533  }
2534  
2535  /**
2536   * __skb_fill_netmem_desc - initialise a fragment in an skb
2537   * @skb: buffer containing fragment to be initialised
2538   * @i: fragment index to initialise
2539   * @netmem: the netmem to use for this fragment
2540   * @off: the offset to the data with @page
2541   * @size: the length of the data
2542   *
2543   * Initialises the @i'th fragment of @skb to point to &size bytes at
2544   * offset @off within @page.
2545   *
2546   * Does not take any additional reference on the fragment.
2547   */
__skb_fill_netmem_desc(struct sk_buff * skb,int i,netmem_ref netmem,int off,int size)2548  static inline void __skb_fill_netmem_desc(struct sk_buff *skb, int i,
2549  					  netmem_ref netmem, int off, int size)
2550  {
2551  	struct page *page;
2552  
2553  	__skb_fill_netmem_desc_noacc(skb_shinfo(skb), i, netmem, off, size);
2554  
2555  	if (netmem_is_net_iov(netmem)) {
2556  		skb->unreadable = true;
2557  		return;
2558  	}
2559  
2560  	page = netmem_to_page(netmem);
2561  
2562  	/* Propagate page pfmemalloc to the skb if we can. The problem is
2563  	 * that not all callers have unique ownership of the page but rely
2564  	 * on page_is_pfmemalloc doing the right thing(tm).
2565  	 */
2566  	page = compound_head(page);
2567  	if (page_is_pfmemalloc(page))
2568  		skb->pfmemalloc = true;
2569  }
2570  
__skb_fill_page_desc(struct sk_buff * skb,int i,struct page * page,int off,int size)2571  static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
2572  					struct page *page, int off, int size)
2573  {
2574  	__skb_fill_netmem_desc(skb, i, page_to_netmem(page), off, size);
2575  }
2576  
skb_fill_netmem_desc(struct sk_buff * skb,int i,netmem_ref netmem,int off,int size)2577  static inline void skb_fill_netmem_desc(struct sk_buff *skb, int i,
2578  					netmem_ref netmem, int off, int size)
2579  {
2580  	__skb_fill_netmem_desc(skb, i, netmem, off, size);
2581  	skb_shinfo(skb)->nr_frags = i + 1;
2582  }
2583  
2584  /**
2585   * skb_fill_page_desc - initialise a paged fragment in an skb
2586   * @skb: buffer containing fragment to be initialised
2587   * @i: paged fragment index to initialise
2588   * @page: the page to use for this fragment
2589   * @off: the offset to the data with @page
2590   * @size: the length of the data
2591   *
2592   * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
2593   * @skb to point to @size bytes at offset @off within @page. In
2594   * addition updates @skb such that @i is the last fragment.
2595   *
2596   * Does not take any additional reference on the fragment.
2597   */
skb_fill_page_desc(struct sk_buff * skb,int i,struct page * page,int off,int size)2598  static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
2599  				      struct page *page, int off, int size)
2600  {
2601  	skb_fill_netmem_desc(skb, i, page_to_netmem(page), off, size);
2602  }
2603  
2604  /**
2605   * skb_fill_page_desc_noacc - initialise a paged fragment in an skb
2606   * @skb: buffer containing fragment to be initialised
2607   * @i: paged fragment index to initialise
2608   * @page: the page to use for this fragment
2609   * @off: the offset to the data with @page
2610   * @size: the length of the data
2611   *
2612   * Variant of skb_fill_page_desc() which does not deal with
2613   * pfmemalloc, if page is not owned by us.
2614   */
skb_fill_page_desc_noacc(struct sk_buff * skb,int i,struct page * page,int off,int size)2615  static inline void skb_fill_page_desc_noacc(struct sk_buff *skb, int i,
2616  					    struct page *page, int off,
2617  					    int size)
2618  {
2619  	struct skb_shared_info *shinfo = skb_shinfo(skb);
2620  
2621  	__skb_fill_page_desc_noacc(shinfo, i, page, off, size);
2622  	shinfo->nr_frags = i + 1;
2623  }
2624  
2625  void skb_add_rx_frag_netmem(struct sk_buff *skb, int i, netmem_ref netmem,
2626  			    int off, int size, unsigned int truesize);
2627  
skb_add_rx_frag(struct sk_buff * skb,int i,struct page * page,int off,int size,unsigned int truesize)2628  static inline void skb_add_rx_frag(struct sk_buff *skb, int i,
2629  				   struct page *page, int off, int size,
2630  				   unsigned int truesize)
2631  {
2632  	skb_add_rx_frag_netmem(skb, i, page_to_netmem(page), off, size,
2633  			       truesize);
2634  }
2635  
2636  void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
2637  			  unsigned int truesize);
2638  
2639  #define SKB_LINEAR_ASSERT(skb)  BUG_ON(skb_is_nonlinear(skb))
2640  
2641  #ifdef NET_SKBUFF_DATA_USES_OFFSET
skb_tail_pointer(const struct sk_buff * skb)2642  static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2643  {
2644  	return skb->head + skb->tail;
2645  }
2646  
skb_reset_tail_pointer(struct sk_buff * skb)2647  static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2648  {
2649  	skb->tail = skb->data - skb->head;
2650  }
2651  
skb_set_tail_pointer(struct sk_buff * skb,const int offset)2652  static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2653  {
2654  	skb_reset_tail_pointer(skb);
2655  	skb->tail += offset;
2656  }
2657  
2658  #else /* NET_SKBUFF_DATA_USES_OFFSET */
skb_tail_pointer(const struct sk_buff * skb)2659  static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2660  {
2661  	return skb->tail;
2662  }
2663  
skb_reset_tail_pointer(struct sk_buff * skb)2664  static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2665  {
2666  	skb->tail = skb->data;
2667  }
2668  
skb_set_tail_pointer(struct sk_buff * skb,const int offset)2669  static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2670  {
2671  	skb->tail = skb->data + offset;
2672  }
2673  
2674  #endif /* NET_SKBUFF_DATA_USES_OFFSET */
2675  
skb_assert_len(struct sk_buff * skb)2676  static inline void skb_assert_len(struct sk_buff *skb)
2677  {
2678  #ifdef CONFIG_DEBUG_NET
2679  	if (WARN_ONCE(!skb->len, "%s\n", __func__))
2680  		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
2681  #endif /* CONFIG_DEBUG_NET */
2682  }
2683  
2684  /*
2685   *	Add data to an sk_buff
2686   */
2687  void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
2688  void *skb_put(struct sk_buff *skb, unsigned int len);
__skb_put(struct sk_buff * skb,unsigned int len)2689  static inline void *__skb_put(struct sk_buff *skb, unsigned int len)
2690  {
2691  	void *tmp = skb_tail_pointer(skb);
2692  	SKB_LINEAR_ASSERT(skb);
2693  	skb->tail += len;
2694  	skb->len  += len;
2695  	return tmp;
2696  }
2697  
__skb_put_zero(struct sk_buff * skb,unsigned int len)2698  static inline void *__skb_put_zero(struct sk_buff *skb, unsigned int len)
2699  {
2700  	void *tmp = __skb_put(skb, len);
2701  
2702  	memset(tmp, 0, len);
2703  	return tmp;
2704  }
2705  
__skb_put_data(struct sk_buff * skb,const void * data,unsigned int len)2706  static inline void *__skb_put_data(struct sk_buff *skb, const void *data,
2707  				   unsigned int len)
2708  {
2709  	void *tmp = __skb_put(skb, len);
2710  
2711  	memcpy(tmp, data, len);
2712  	return tmp;
2713  }
2714  
__skb_put_u8(struct sk_buff * skb,u8 val)2715  static inline void __skb_put_u8(struct sk_buff *skb, u8 val)
2716  {
2717  	*(u8 *)__skb_put(skb, 1) = val;
2718  }
2719  
skb_put_zero(struct sk_buff * skb,unsigned int len)2720  static inline void *skb_put_zero(struct sk_buff *skb, unsigned int len)
2721  {
2722  	void *tmp = skb_put(skb, len);
2723  
2724  	memset(tmp, 0, len);
2725  
2726  	return tmp;
2727  }
2728  
skb_put_data(struct sk_buff * skb,const void * data,unsigned int len)2729  static inline void *skb_put_data(struct sk_buff *skb, const void *data,
2730  				 unsigned int len)
2731  {
2732  	void *tmp = skb_put(skb, len);
2733  
2734  	memcpy(tmp, data, len);
2735  
2736  	return tmp;
2737  }
2738  
skb_put_u8(struct sk_buff * skb,u8 val)2739  static inline void skb_put_u8(struct sk_buff *skb, u8 val)
2740  {
2741  	*(u8 *)skb_put(skb, 1) = val;
2742  }
2743  
2744  void *skb_push(struct sk_buff *skb, unsigned int len);
__skb_push(struct sk_buff * skb,unsigned int len)2745  static inline void *__skb_push(struct sk_buff *skb, unsigned int len)
2746  {
2747  	DEBUG_NET_WARN_ON_ONCE(len > INT_MAX);
2748  
2749  	skb->data -= len;
2750  	skb->len  += len;
2751  	return skb->data;
2752  }
2753  
2754  void *skb_pull(struct sk_buff *skb, unsigned int len);
__skb_pull(struct sk_buff * skb,unsigned int len)2755  static inline void *__skb_pull(struct sk_buff *skb, unsigned int len)
2756  {
2757  	DEBUG_NET_WARN_ON_ONCE(len > INT_MAX);
2758  
2759  	skb->len -= len;
2760  	if (unlikely(skb->len < skb->data_len)) {
2761  #if defined(CONFIG_DEBUG_NET)
2762  		skb->len += len;
2763  		pr_err("__skb_pull(len=%u)\n", len);
2764  		skb_dump(KERN_ERR, skb, false);
2765  #endif
2766  		BUG();
2767  	}
2768  	return skb->data += len;
2769  }
2770  
skb_pull_inline(struct sk_buff * skb,unsigned int len)2771  static inline void *skb_pull_inline(struct sk_buff *skb, unsigned int len)
2772  {
2773  	return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
2774  }
2775  
2776  void *skb_pull_data(struct sk_buff *skb, size_t len);
2777  
2778  void *__pskb_pull_tail(struct sk_buff *skb, int delta);
2779  
2780  static inline enum skb_drop_reason
pskb_may_pull_reason(struct sk_buff * skb,unsigned int len)2781  pskb_may_pull_reason(struct sk_buff *skb, unsigned int len)
2782  {
2783  	DEBUG_NET_WARN_ON_ONCE(len > INT_MAX);
2784  
2785  	if (likely(len <= skb_headlen(skb)))
2786  		return SKB_NOT_DROPPED_YET;
2787  
2788  	if (unlikely(len > skb->len))
2789  		return SKB_DROP_REASON_PKT_TOO_SMALL;
2790  
2791  	if (unlikely(!__pskb_pull_tail(skb, len - skb_headlen(skb))))
2792  		return SKB_DROP_REASON_NOMEM;
2793  
2794  	return SKB_NOT_DROPPED_YET;
2795  }
2796  
pskb_may_pull(struct sk_buff * skb,unsigned int len)2797  static inline bool pskb_may_pull(struct sk_buff *skb, unsigned int len)
2798  {
2799  	return pskb_may_pull_reason(skb, len) == SKB_NOT_DROPPED_YET;
2800  }
2801  
pskb_pull(struct sk_buff * skb,unsigned int len)2802  static inline void *pskb_pull(struct sk_buff *skb, unsigned int len)
2803  {
2804  	if (!pskb_may_pull(skb, len))
2805  		return NULL;
2806  
2807  	skb->len -= len;
2808  	return skb->data += len;
2809  }
2810  
2811  void skb_condense(struct sk_buff *skb);
2812  
2813  /**
2814   *	skb_headroom - bytes at buffer head
2815   *	@skb: buffer to check
2816   *
2817   *	Return the number of bytes of free space at the head of an &sk_buff.
2818   */
skb_headroom(const struct sk_buff * skb)2819  static inline unsigned int skb_headroom(const struct sk_buff *skb)
2820  {
2821  	return skb->data - skb->head;
2822  }
2823  
2824  /**
2825   *	skb_tailroom - bytes at buffer end
2826   *	@skb: buffer to check
2827   *
2828   *	Return the number of bytes of free space at the tail of an sk_buff
2829   */
skb_tailroom(const struct sk_buff * skb)2830  static inline int skb_tailroom(const struct sk_buff *skb)
2831  {
2832  	return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
2833  }
2834  
2835  /**
2836   *	skb_availroom - bytes at buffer end
2837   *	@skb: buffer to check
2838   *
2839   *	Return the number of bytes of free space at the tail of an sk_buff
2840   *	allocated by sk_stream_alloc()
2841   */
skb_availroom(const struct sk_buff * skb)2842  static inline int skb_availroom(const struct sk_buff *skb)
2843  {
2844  	if (skb_is_nonlinear(skb))
2845  		return 0;
2846  
2847  	return skb->end - skb->tail - skb->reserved_tailroom;
2848  }
2849  
2850  /**
2851   *	skb_reserve - adjust headroom
2852   *	@skb: buffer to alter
2853   *	@len: bytes to move
2854   *
2855   *	Increase the headroom of an empty &sk_buff by reducing the tail
2856   *	room. This is only allowed for an empty buffer.
2857   */
skb_reserve(struct sk_buff * skb,int len)2858  static inline void skb_reserve(struct sk_buff *skb, int len)
2859  {
2860  	skb->data += len;
2861  	skb->tail += len;
2862  }
2863  
2864  /**
2865   *	skb_tailroom_reserve - adjust reserved_tailroom
2866   *	@skb: buffer to alter
2867   *	@mtu: maximum amount of headlen permitted
2868   *	@needed_tailroom: minimum amount of reserved_tailroom
2869   *
2870   *	Set reserved_tailroom so that headlen can be as large as possible but
2871   *	not larger than mtu and tailroom cannot be smaller than
2872   *	needed_tailroom.
2873   *	The required headroom should already have been reserved before using
2874   *	this function.
2875   */
skb_tailroom_reserve(struct sk_buff * skb,unsigned int mtu,unsigned int needed_tailroom)2876  static inline void skb_tailroom_reserve(struct sk_buff *skb, unsigned int mtu,
2877  					unsigned int needed_tailroom)
2878  {
2879  	SKB_LINEAR_ASSERT(skb);
2880  	if (mtu < skb_tailroom(skb) - needed_tailroom)
2881  		/* use at most mtu */
2882  		skb->reserved_tailroom = skb_tailroom(skb) - mtu;
2883  	else
2884  		/* use up to all available space */
2885  		skb->reserved_tailroom = needed_tailroom;
2886  }
2887  
2888  #define ENCAP_TYPE_ETHER	0
2889  #define ENCAP_TYPE_IPPROTO	1
2890  
skb_set_inner_protocol(struct sk_buff * skb,__be16 protocol)2891  static inline void skb_set_inner_protocol(struct sk_buff *skb,
2892  					  __be16 protocol)
2893  {
2894  	skb->inner_protocol = protocol;
2895  	skb->inner_protocol_type = ENCAP_TYPE_ETHER;
2896  }
2897  
skb_set_inner_ipproto(struct sk_buff * skb,__u8 ipproto)2898  static inline void skb_set_inner_ipproto(struct sk_buff *skb,
2899  					 __u8 ipproto)
2900  {
2901  	skb->inner_ipproto = ipproto;
2902  	skb->inner_protocol_type = ENCAP_TYPE_IPPROTO;
2903  }
2904  
skb_reset_inner_headers(struct sk_buff * skb)2905  static inline void skb_reset_inner_headers(struct sk_buff *skb)
2906  {
2907  	skb->inner_mac_header = skb->mac_header;
2908  	skb->inner_network_header = skb->network_header;
2909  	skb->inner_transport_header = skb->transport_header;
2910  }
2911  
skb_reset_mac_len(struct sk_buff * skb)2912  static inline void skb_reset_mac_len(struct sk_buff *skb)
2913  {
2914  	skb->mac_len = skb->network_header - skb->mac_header;
2915  }
2916  
skb_inner_transport_header(const struct sk_buff * skb)2917  static inline unsigned char *skb_inner_transport_header(const struct sk_buff
2918  							*skb)
2919  {
2920  	return skb->head + skb->inner_transport_header;
2921  }
2922  
skb_inner_transport_offset(const struct sk_buff * skb)2923  static inline int skb_inner_transport_offset(const struct sk_buff *skb)
2924  {
2925  	return skb_inner_transport_header(skb) - skb->data;
2926  }
2927  
skb_reset_inner_transport_header(struct sk_buff * skb)2928  static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
2929  {
2930  	skb->inner_transport_header = skb->data - skb->head;
2931  }
2932  
skb_set_inner_transport_header(struct sk_buff * skb,const int offset)2933  static inline void skb_set_inner_transport_header(struct sk_buff *skb,
2934  						   const int offset)
2935  {
2936  	skb_reset_inner_transport_header(skb);
2937  	skb->inner_transport_header += offset;
2938  }
2939  
skb_inner_network_header(const struct sk_buff * skb)2940  static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
2941  {
2942  	return skb->head + skb->inner_network_header;
2943  }
2944  
skb_reset_inner_network_header(struct sk_buff * skb)2945  static inline void skb_reset_inner_network_header(struct sk_buff *skb)
2946  {
2947  	skb->inner_network_header = skb->data - skb->head;
2948  }
2949  
skb_set_inner_network_header(struct sk_buff * skb,const int offset)2950  static inline void skb_set_inner_network_header(struct sk_buff *skb,
2951  						const int offset)
2952  {
2953  	skb_reset_inner_network_header(skb);
2954  	skb->inner_network_header += offset;
2955  }
2956  
skb_inner_network_header_was_set(const struct sk_buff * skb)2957  static inline bool skb_inner_network_header_was_set(const struct sk_buff *skb)
2958  {
2959  	return skb->inner_network_header > 0;
2960  }
2961  
skb_inner_mac_header(const struct sk_buff * skb)2962  static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
2963  {
2964  	return skb->head + skb->inner_mac_header;
2965  }
2966  
skb_reset_inner_mac_header(struct sk_buff * skb)2967  static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
2968  {
2969  	skb->inner_mac_header = skb->data - skb->head;
2970  }
2971  
skb_set_inner_mac_header(struct sk_buff * skb,const int offset)2972  static inline void skb_set_inner_mac_header(struct sk_buff *skb,
2973  					    const int offset)
2974  {
2975  	skb_reset_inner_mac_header(skb);
2976  	skb->inner_mac_header += offset;
2977  }
skb_transport_header_was_set(const struct sk_buff * skb)2978  static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
2979  {
2980  	return skb->transport_header != (typeof(skb->transport_header))~0U;
2981  }
2982  
skb_transport_header(const struct sk_buff * skb)2983  static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
2984  {
2985  	DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb));
2986  	return skb->head + skb->transport_header;
2987  }
2988  
skb_reset_transport_header(struct sk_buff * skb)2989  static inline void skb_reset_transport_header(struct sk_buff *skb)
2990  {
2991  	skb->transport_header = skb->data - skb->head;
2992  }
2993  
skb_set_transport_header(struct sk_buff * skb,const int offset)2994  static inline void skb_set_transport_header(struct sk_buff *skb,
2995  					    const int offset)
2996  {
2997  	skb_reset_transport_header(skb);
2998  	skb->transport_header += offset;
2999  }
3000  
skb_network_header(const struct sk_buff * skb)3001  static inline unsigned char *skb_network_header(const struct sk_buff *skb)
3002  {
3003  	return skb->head + skb->network_header;
3004  }
3005  
skb_reset_network_header(struct sk_buff * skb)3006  static inline void skb_reset_network_header(struct sk_buff *skb)
3007  {
3008  	skb->network_header = skb->data - skb->head;
3009  }
3010  
skb_set_network_header(struct sk_buff * skb,const int offset)3011  static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
3012  {
3013  	skb_reset_network_header(skb);
3014  	skb->network_header += offset;
3015  }
3016  
skb_mac_header_was_set(const struct sk_buff * skb)3017  static inline int skb_mac_header_was_set(const struct sk_buff *skb)
3018  {
3019  	return skb->mac_header != (typeof(skb->mac_header))~0U;
3020  }
3021  
skb_mac_header(const struct sk_buff * skb)3022  static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
3023  {
3024  	DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb));
3025  	return skb->head + skb->mac_header;
3026  }
3027  
skb_mac_offset(const struct sk_buff * skb)3028  static inline int skb_mac_offset(const struct sk_buff *skb)
3029  {
3030  	return skb_mac_header(skb) - skb->data;
3031  }
3032  
skb_mac_header_len(const struct sk_buff * skb)3033  static inline u32 skb_mac_header_len(const struct sk_buff *skb)
3034  {
3035  	DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb));
3036  	return skb->network_header - skb->mac_header;
3037  }
3038  
skb_unset_mac_header(struct sk_buff * skb)3039  static inline void skb_unset_mac_header(struct sk_buff *skb)
3040  {
3041  	skb->mac_header = (typeof(skb->mac_header))~0U;
3042  }
3043  
skb_reset_mac_header(struct sk_buff * skb)3044  static inline void skb_reset_mac_header(struct sk_buff *skb)
3045  {
3046  	skb->mac_header = skb->data - skb->head;
3047  }
3048  
skb_set_mac_header(struct sk_buff * skb,const int offset)3049  static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
3050  {
3051  	skb_reset_mac_header(skb);
3052  	skb->mac_header += offset;
3053  }
3054  
skb_pop_mac_header(struct sk_buff * skb)3055  static inline void skb_pop_mac_header(struct sk_buff *skb)
3056  {
3057  	skb->mac_header = skb->network_header;
3058  }
3059  
skb_probe_transport_header(struct sk_buff * skb)3060  static inline void skb_probe_transport_header(struct sk_buff *skb)
3061  {
3062  	struct flow_keys_basic keys;
3063  
3064  	if (skb_transport_header_was_set(skb))
3065  		return;
3066  
3067  	if (skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
3068  					     NULL, 0, 0, 0, 0))
3069  		skb_set_transport_header(skb, keys.control.thoff);
3070  }
3071  
skb_mac_header_rebuild(struct sk_buff * skb)3072  static inline void skb_mac_header_rebuild(struct sk_buff *skb)
3073  {
3074  	if (skb_mac_header_was_set(skb)) {
3075  		const unsigned char *old_mac = skb_mac_header(skb);
3076  
3077  		skb_set_mac_header(skb, -skb->mac_len);
3078  		memmove(skb_mac_header(skb), old_mac, skb->mac_len);
3079  	}
3080  }
3081  
3082  /* Move the full mac header up to current network_header.
3083   * Leaves skb->data pointing at offset skb->mac_len into the mac_header.
3084   * Must be provided the complete mac header length.
3085   */
skb_mac_header_rebuild_full(struct sk_buff * skb,u32 full_mac_len)3086  static inline void skb_mac_header_rebuild_full(struct sk_buff *skb, u32 full_mac_len)
3087  {
3088  	if (skb_mac_header_was_set(skb)) {
3089  		const unsigned char *old_mac = skb_mac_header(skb);
3090  
3091  		skb_set_mac_header(skb, -full_mac_len);
3092  		memmove(skb_mac_header(skb), old_mac, full_mac_len);
3093  		__skb_push(skb, full_mac_len - skb->mac_len);
3094  	}
3095  }
3096  
skb_checksum_start_offset(const struct sk_buff * skb)3097  static inline int skb_checksum_start_offset(const struct sk_buff *skb)
3098  {
3099  	return skb->csum_start - skb_headroom(skb);
3100  }
3101  
skb_checksum_start(const struct sk_buff * skb)3102  static inline unsigned char *skb_checksum_start(const struct sk_buff *skb)
3103  {
3104  	return skb->head + skb->csum_start;
3105  }
3106  
skb_transport_offset(const struct sk_buff * skb)3107  static inline int skb_transport_offset(const struct sk_buff *skb)
3108  {
3109  	return skb_transport_header(skb) - skb->data;
3110  }
3111  
skb_network_header_len(const struct sk_buff * skb)3112  static inline u32 skb_network_header_len(const struct sk_buff *skb)
3113  {
3114  	DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb));
3115  	return skb->transport_header - skb->network_header;
3116  }
3117  
skb_inner_network_header_len(const struct sk_buff * skb)3118  static inline u32 skb_inner_network_header_len(const struct sk_buff *skb)
3119  {
3120  	return skb->inner_transport_header - skb->inner_network_header;
3121  }
3122  
skb_network_offset(const struct sk_buff * skb)3123  static inline int skb_network_offset(const struct sk_buff *skb)
3124  {
3125  	return skb_network_header(skb) - skb->data;
3126  }
3127  
skb_inner_network_offset(const struct sk_buff * skb)3128  static inline int skb_inner_network_offset(const struct sk_buff *skb)
3129  {
3130  	return skb_inner_network_header(skb) - skb->data;
3131  }
3132  
pskb_network_may_pull(struct sk_buff * skb,unsigned int len)3133  static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
3134  {
3135  	return pskb_may_pull(skb, skb_network_offset(skb) + len);
3136  }
3137  
3138  /*
3139   * CPUs often take a performance hit when accessing unaligned memory
3140   * locations. The actual performance hit varies, it can be small if the
3141   * hardware handles it or large if we have to take an exception and fix it
3142   * in software.
3143   *
3144   * Since an ethernet header is 14 bytes network drivers often end up with
3145   * the IP header at an unaligned offset. The IP header can be aligned by
3146   * shifting the start of the packet by 2 bytes. Drivers should do this
3147   * with:
3148   *
3149   * skb_reserve(skb, NET_IP_ALIGN);
3150   *
3151   * The downside to this alignment of the IP header is that the DMA is now
3152   * unaligned. On some architectures the cost of an unaligned DMA is high
3153   * and this cost outweighs the gains made by aligning the IP header.
3154   *
3155   * Since this trade off varies between architectures, we allow NET_IP_ALIGN
3156   * to be overridden.
3157   */
3158  #ifndef NET_IP_ALIGN
3159  #define NET_IP_ALIGN	2
3160  #endif
3161  
3162  /*
3163   * The networking layer reserves some headroom in skb data (via
3164   * dev_alloc_skb). This is used to avoid having to reallocate skb data when
3165   * the header has to grow. In the default case, if the header has to grow
3166   * 32 bytes or less we avoid the reallocation.
3167   *
3168   * Unfortunately this headroom changes the DMA alignment of the resulting
3169   * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
3170   * on some architectures. An architecture can override this value,
3171   * perhaps setting it to a cacheline in size (since that will maintain
3172   * cacheline alignment of the DMA). It must be a power of 2.
3173   *
3174   * Various parts of the networking layer expect at least 32 bytes of
3175   * headroom, you should not reduce this.
3176   *
3177   * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
3178   * to reduce average number of cache lines per packet.
3179   * get_rps_cpu() for example only access one 64 bytes aligned block :
3180   * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
3181   */
3182  #ifndef NET_SKB_PAD
3183  #define NET_SKB_PAD	max(32, L1_CACHE_BYTES)
3184  #endif
3185  
3186  int ___pskb_trim(struct sk_buff *skb, unsigned int len);
3187  
__skb_set_length(struct sk_buff * skb,unsigned int len)3188  static inline void __skb_set_length(struct sk_buff *skb, unsigned int len)
3189  {
3190  	if (WARN_ON(skb_is_nonlinear(skb)))
3191  		return;
3192  	skb->len = len;
3193  	skb_set_tail_pointer(skb, len);
3194  }
3195  
__skb_trim(struct sk_buff * skb,unsigned int len)3196  static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
3197  {
3198  	__skb_set_length(skb, len);
3199  }
3200  
3201  void skb_trim(struct sk_buff *skb, unsigned int len);
3202  
__pskb_trim(struct sk_buff * skb,unsigned int len)3203  static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
3204  {
3205  	if (skb->data_len)
3206  		return ___pskb_trim(skb, len);
3207  	__skb_trim(skb, len);
3208  	return 0;
3209  }
3210  
pskb_trim(struct sk_buff * skb,unsigned int len)3211  static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
3212  {
3213  	return (len < skb->len) ? __pskb_trim(skb, len) : 0;
3214  }
3215  
3216  /**
3217   *	pskb_trim_unique - remove end from a paged unique (not cloned) buffer
3218   *	@skb: buffer to alter
3219   *	@len: new length
3220   *
3221   *	This is identical to pskb_trim except that the caller knows that
3222   *	the skb is not cloned so we should never get an error due to out-
3223   *	of-memory.
3224   */
pskb_trim_unique(struct sk_buff * skb,unsigned int len)3225  static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
3226  {
3227  	int err = pskb_trim(skb, len);
3228  	BUG_ON(err);
3229  }
3230  
__skb_grow(struct sk_buff * skb,unsigned int len)3231  static inline int __skb_grow(struct sk_buff *skb, unsigned int len)
3232  {
3233  	unsigned int diff = len - skb->len;
3234  
3235  	if (skb_tailroom(skb) < diff) {
3236  		int ret = pskb_expand_head(skb, 0, diff - skb_tailroom(skb),
3237  					   GFP_ATOMIC);
3238  		if (ret)
3239  			return ret;
3240  	}
3241  	__skb_set_length(skb, len);
3242  	return 0;
3243  }
3244  
3245  /**
3246   *	skb_orphan - orphan a buffer
3247   *	@skb: buffer to orphan
3248   *
3249   *	If a buffer currently has an owner then we call the owner's
3250   *	destructor function and make the @skb unowned. The buffer continues
3251   *	to exist but is no longer charged to its former owner.
3252   */
skb_orphan(struct sk_buff * skb)3253  static inline void skb_orphan(struct sk_buff *skb)
3254  {
3255  	if (skb->destructor) {
3256  		skb->destructor(skb);
3257  		skb->destructor = NULL;
3258  		skb->sk		= NULL;
3259  	} else {
3260  		BUG_ON(skb->sk);
3261  	}
3262  }
3263  
3264  /**
3265   *	skb_orphan_frags - orphan the frags contained in a buffer
3266   *	@skb: buffer to orphan frags from
3267   *	@gfp_mask: allocation mask for replacement pages
3268   *
3269   *	For each frag in the SKB which needs a destructor (i.e. has an
3270   *	owner) create a copy of that frag and release the original
3271   *	page by calling the destructor.
3272   */
skb_orphan_frags(struct sk_buff * skb,gfp_t gfp_mask)3273  static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
3274  {
3275  	if (likely(!skb_zcopy(skb)))
3276  		return 0;
3277  	if (skb_shinfo(skb)->flags & SKBFL_DONT_ORPHAN)
3278  		return 0;
3279  	return skb_copy_ubufs(skb, gfp_mask);
3280  }
3281  
3282  /* Frags must be orphaned, even if refcounted, if skb might loop to rx path */
skb_orphan_frags_rx(struct sk_buff * skb,gfp_t gfp_mask)3283  static inline int skb_orphan_frags_rx(struct sk_buff *skb, gfp_t gfp_mask)
3284  {
3285  	if (likely(!skb_zcopy(skb)))
3286  		return 0;
3287  	return skb_copy_ubufs(skb, gfp_mask);
3288  }
3289  
3290  /**
3291   *	__skb_queue_purge_reason - empty a list
3292   *	@list: list to empty
3293   *	@reason: drop reason
3294   *
3295   *	Delete all buffers on an &sk_buff list. Each buffer is removed from
3296   *	the list and one reference dropped. This function does not take the
3297   *	list lock and the caller must hold the relevant locks to use it.
3298   */
__skb_queue_purge_reason(struct sk_buff_head * list,enum skb_drop_reason reason)3299  static inline void __skb_queue_purge_reason(struct sk_buff_head *list,
3300  					    enum skb_drop_reason reason)
3301  {
3302  	struct sk_buff *skb;
3303  
3304  	while ((skb = __skb_dequeue(list)) != NULL)
3305  		kfree_skb_reason(skb, reason);
3306  }
3307  
__skb_queue_purge(struct sk_buff_head * list)3308  static inline void __skb_queue_purge(struct sk_buff_head *list)
3309  {
3310  	__skb_queue_purge_reason(list, SKB_DROP_REASON_QUEUE_PURGE);
3311  }
3312  
3313  void skb_queue_purge_reason(struct sk_buff_head *list,
3314  			    enum skb_drop_reason reason);
3315  
skb_queue_purge(struct sk_buff_head * list)3316  static inline void skb_queue_purge(struct sk_buff_head *list)
3317  {
3318  	skb_queue_purge_reason(list, SKB_DROP_REASON_QUEUE_PURGE);
3319  }
3320  
3321  unsigned int skb_rbtree_purge(struct rb_root *root);
3322  void skb_errqueue_purge(struct sk_buff_head *list);
3323  
3324  void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);
3325  
3326  /**
3327   * netdev_alloc_frag - allocate a page fragment
3328   * @fragsz: fragment size
3329   *
3330   * Allocates a frag from a page for receive buffer.
3331   * Uses GFP_ATOMIC allocations.
3332   */
netdev_alloc_frag(unsigned int fragsz)3333  static inline void *netdev_alloc_frag(unsigned int fragsz)
3334  {
3335  	return __netdev_alloc_frag_align(fragsz, ~0u);
3336  }
3337  
netdev_alloc_frag_align(unsigned int fragsz,unsigned int align)3338  static inline void *netdev_alloc_frag_align(unsigned int fragsz,
3339  					    unsigned int align)
3340  {
3341  	WARN_ON_ONCE(!is_power_of_2(align));
3342  	return __netdev_alloc_frag_align(fragsz, -align);
3343  }
3344  
3345  struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length,
3346  				   gfp_t gfp_mask);
3347  
3348  /**
3349   *	netdev_alloc_skb - allocate an skbuff for rx on a specific device
3350   *	@dev: network device to receive on
3351   *	@length: length to allocate
3352   *
3353   *	Allocate a new &sk_buff and assign it a usage count of one. The
3354   *	buffer has unspecified headroom built in. Users should allocate
3355   *	the headroom they think they need without accounting for the
3356   *	built in space. The built in space is used for optimisations.
3357   *
3358   *	%NULL is returned if there is no free memory. Although this function
3359   *	allocates memory it can be called from an interrupt.
3360   */
netdev_alloc_skb(struct net_device * dev,unsigned int length)3361  static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
3362  					       unsigned int length)
3363  {
3364  	return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
3365  }
3366  
3367  /* legacy helper around __netdev_alloc_skb() */
__dev_alloc_skb(unsigned int length,gfp_t gfp_mask)3368  static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
3369  					      gfp_t gfp_mask)
3370  {
3371  	return __netdev_alloc_skb(NULL, length, gfp_mask);
3372  }
3373  
3374  /* legacy helper around netdev_alloc_skb() */
dev_alloc_skb(unsigned int length)3375  static inline struct sk_buff *dev_alloc_skb(unsigned int length)
3376  {
3377  	return netdev_alloc_skb(NULL, length);
3378  }
3379  
3380  
__netdev_alloc_skb_ip_align(struct net_device * dev,unsigned int length,gfp_t gfp)3381  static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
3382  		unsigned int length, gfp_t gfp)
3383  {
3384  	struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
3385  
3386  	if (NET_IP_ALIGN && skb)
3387  		skb_reserve(skb, NET_IP_ALIGN);
3388  	return skb;
3389  }
3390  
netdev_alloc_skb_ip_align(struct net_device * dev,unsigned int length)3391  static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
3392  		unsigned int length)
3393  {
3394  	return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
3395  }
3396  
skb_free_frag(void * addr)3397  static inline void skb_free_frag(void *addr)
3398  {
3399  	page_frag_free(addr);
3400  }
3401  
3402  void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);
3403  
napi_alloc_frag(unsigned int fragsz)3404  static inline void *napi_alloc_frag(unsigned int fragsz)
3405  {
3406  	return __napi_alloc_frag_align(fragsz, ~0u);
3407  }
3408  
napi_alloc_frag_align(unsigned int fragsz,unsigned int align)3409  static inline void *napi_alloc_frag_align(unsigned int fragsz,
3410  					  unsigned int align)
3411  {
3412  	WARN_ON_ONCE(!is_power_of_2(align));
3413  	return __napi_alloc_frag_align(fragsz, -align);
3414  }
3415  
3416  struct sk_buff *napi_alloc_skb(struct napi_struct *napi, unsigned int length);
3417  void napi_consume_skb(struct sk_buff *skb, int budget);
3418  
3419  void napi_skb_free_stolen_head(struct sk_buff *skb);
3420  void __napi_kfree_skb(struct sk_buff *skb, enum skb_drop_reason reason);
3421  
3422  /**
3423   * __dev_alloc_pages - allocate page for network Rx
3424   * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
3425   * @order: size of the allocation
3426   *
3427   * Allocate a new page.
3428   *
3429   * %NULL is returned if there is no free memory.
3430  */
__dev_alloc_pages_noprof(gfp_t gfp_mask,unsigned int order)3431  static inline struct page *__dev_alloc_pages_noprof(gfp_t gfp_mask,
3432  					     unsigned int order)
3433  {
3434  	/* This piece of code contains several assumptions.
3435  	 * 1.  This is for device Rx, therefore a cold page is preferred.
3436  	 * 2.  The expectation is the user wants a compound page.
3437  	 * 3.  If requesting a order 0 page it will not be compound
3438  	 *     due to the check to see if order has a value in prep_new_page
3439  	 * 4.  __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
3440  	 *     code in gfp_to_alloc_flags that should be enforcing this.
3441  	 */
3442  	gfp_mask |= __GFP_COMP | __GFP_MEMALLOC;
3443  
3444  	return alloc_pages_node_noprof(NUMA_NO_NODE, gfp_mask, order);
3445  }
3446  #define __dev_alloc_pages(...)	alloc_hooks(__dev_alloc_pages_noprof(__VA_ARGS__))
3447  
3448  /*
3449   * This specialized allocator has to be a macro for its allocations to be
3450   * accounted separately (to have a separate alloc_tag).
3451   */
3452  #define dev_alloc_pages(_order) __dev_alloc_pages(GFP_ATOMIC | __GFP_NOWARN, _order)
3453  
3454  /**
3455   * __dev_alloc_page - allocate a page for network Rx
3456   * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
3457   *
3458   * Allocate a new page.
3459   *
3460   * %NULL is returned if there is no free memory.
3461   */
__dev_alloc_page_noprof(gfp_t gfp_mask)3462  static inline struct page *__dev_alloc_page_noprof(gfp_t gfp_mask)
3463  {
3464  	return __dev_alloc_pages_noprof(gfp_mask, 0);
3465  }
3466  #define __dev_alloc_page(...)	alloc_hooks(__dev_alloc_page_noprof(__VA_ARGS__))
3467  
3468  /*
3469   * This specialized allocator has to be a macro for its allocations to be
3470   * accounted separately (to have a separate alloc_tag).
3471   */
3472  #define dev_alloc_page()	dev_alloc_pages(0)
3473  
3474  /**
3475   * dev_page_is_reusable - check whether a page can be reused for network Rx
3476   * @page: the page to test
3477   *
3478   * A page shouldn't be considered for reusing/recycling if it was allocated
3479   * under memory pressure or at a distant memory node.
3480   *
3481   * Returns false if this page should be returned to page allocator, true
3482   * otherwise.
3483   */
dev_page_is_reusable(const struct page * page)3484  static inline bool dev_page_is_reusable(const struct page *page)
3485  {
3486  	return likely(page_to_nid(page) == numa_mem_id() &&
3487  		      !page_is_pfmemalloc(page));
3488  }
3489  
3490  /**
3491   *	skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
3492   *	@page: The page that was allocated from skb_alloc_page
3493   *	@skb: The skb that may need pfmemalloc set
3494   */
skb_propagate_pfmemalloc(const struct page * page,struct sk_buff * skb)3495  static inline void skb_propagate_pfmemalloc(const struct page *page,
3496  					    struct sk_buff *skb)
3497  {
3498  	if (page_is_pfmemalloc(page))
3499  		skb->pfmemalloc = true;
3500  }
3501  
3502  /**
3503   * skb_frag_off() - Returns the offset of a skb fragment
3504   * @frag: the paged fragment
3505   */
skb_frag_off(const skb_frag_t * frag)3506  static inline unsigned int skb_frag_off(const skb_frag_t *frag)
3507  {
3508  	return frag->offset;
3509  }
3510  
3511  /**
3512   * skb_frag_off_add() - Increments the offset of a skb fragment by @delta
3513   * @frag: skb fragment
3514   * @delta: value to add
3515   */
skb_frag_off_add(skb_frag_t * frag,int delta)3516  static inline void skb_frag_off_add(skb_frag_t *frag, int delta)
3517  {
3518  	frag->offset += delta;
3519  }
3520  
3521  /**
3522   * skb_frag_off_set() - Sets the offset of a skb fragment
3523   * @frag: skb fragment
3524   * @offset: offset of fragment
3525   */
skb_frag_off_set(skb_frag_t * frag,unsigned int offset)3526  static inline void skb_frag_off_set(skb_frag_t *frag, unsigned int offset)
3527  {
3528  	frag->offset = offset;
3529  }
3530  
3531  /**
3532   * skb_frag_off_copy() - Sets the offset of a skb fragment from another fragment
3533   * @fragto: skb fragment where offset is set
3534   * @fragfrom: skb fragment offset is copied from
3535   */
skb_frag_off_copy(skb_frag_t * fragto,const skb_frag_t * fragfrom)3536  static inline void skb_frag_off_copy(skb_frag_t *fragto,
3537  				     const skb_frag_t *fragfrom)
3538  {
3539  	fragto->offset = fragfrom->offset;
3540  }
3541  
3542  /* Return: true if the skb_frag contains a net_iov. */
skb_frag_is_net_iov(const skb_frag_t * frag)3543  static inline bool skb_frag_is_net_iov(const skb_frag_t *frag)
3544  {
3545  	return netmem_is_net_iov(frag->netmem);
3546  }
3547  
3548  /**
3549   * skb_frag_net_iov - retrieve the net_iov referred to by fragment
3550   * @frag: the fragment
3551   *
3552   * Return: the &struct net_iov associated with @frag. Returns NULL if this
3553   * frag has no associated net_iov.
3554   */
skb_frag_net_iov(const skb_frag_t * frag)3555  static inline struct net_iov *skb_frag_net_iov(const skb_frag_t *frag)
3556  {
3557  	if (!skb_frag_is_net_iov(frag))
3558  		return NULL;
3559  
3560  	return netmem_to_net_iov(frag->netmem);
3561  }
3562  
3563  /**
3564   * skb_frag_page - retrieve the page referred to by a paged fragment
3565   * @frag: the paged fragment
3566   *
3567   * Return: the &struct page associated with @frag. Returns NULL if this frag
3568   * has no associated page.
3569   */
skb_frag_page(const skb_frag_t * frag)3570  static inline struct page *skb_frag_page(const skb_frag_t *frag)
3571  {
3572  	if (skb_frag_is_net_iov(frag))
3573  		return NULL;
3574  
3575  	return netmem_to_page(frag->netmem);
3576  }
3577  
3578  /**
3579   * skb_frag_netmem - retrieve the netmem referred to by a fragment
3580   * @frag: the fragment
3581   *
3582   * Return: the &netmem_ref associated with @frag.
3583   */
skb_frag_netmem(const skb_frag_t * frag)3584  static inline netmem_ref skb_frag_netmem(const skb_frag_t *frag)
3585  {
3586  	return frag->netmem;
3587  }
3588  
3589  int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb,
3590  		    unsigned int headroom);
3591  int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb,
3592  			 struct bpf_prog *prog);
3593  
3594  /**
3595   * skb_frag_address - gets the address of the data contained in a paged fragment
3596   * @frag: the paged fragment buffer
3597   *
3598   * Returns the address of the data within @frag. The page must already
3599   * be mapped.
3600   */
skb_frag_address(const skb_frag_t * frag)3601  static inline void *skb_frag_address(const skb_frag_t *frag)
3602  {
3603  	if (!skb_frag_page(frag))
3604  		return NULL;
3605  
3606  	return page_address(skb_frag_page(frag)) + skb_frag_off(frag);
3607  }
3608  
3609  /**
3610   * skb_frag_address_safe - gets the address of the data contained in a paged fragment
3611   * @frag: the paged fragment buffer
3612   *
3613   * Returns the address of the data within @frag. Checks that the page
3614   * is mapped and returns %NULL otherwise.
3615   */
skb_frag_address_safe(const skb_frag_t * frag)3616  static inline void *skb_frag_address_safe(const skb_frag_t *frag)
3617  {
3618  	void *ptr = page_address(skb_frag_page(frag));
3619  	if (unlikely(!ptr))
3620  		return NULL;
3621  
3622  	return ptr + skb_frag_off(frag);
3623  }
3624  
3625  /**
3626   * skb_frag_page_copy() - sets the page in a fragment from another fragment
3627   * @fragto: skb fragment where page is set
3628   * @fragfrom: skb fragment page is copied from
3629   */
skb_frag_page_copy(skb_frag_t * fragto,const skb_frag_t * fragfrom)3630  static inline void skb_frag_page_copy(skb_frag_t *fragto,
3631  				      const skb_frag_t *fragfrom)
3632  {
3633  	fragto->netmem = fragfrom->netmem;
3634  }
3635  
3636  bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);
3637  
3638  /**
3639   * skb_frag_dma_map - maps a paged fragment via the DMA API
3640   * @dev: the device to map the fragment to
3641   * @frag: the paged fragment to map
3642   * @offset: the offset within the fragment (starting at the
3643   *          fragment's own offset)
3644   * @size: the number of bytes to map
3645   * @dir: the direction of the mapping (``PCI_DMA_*``)
3646   *
3647   * Maps the page associated with @frag to @device.
3648   */
skb_frag_dma_map(struct device * dev,const skb_frag_t * frag,size_t offset,size_t size,enum dma_data_direction dir)3649  static inline dma_addr_t skb_frag_dma_map(struct device *dev,
3650  					  const skb_frag_t *frag,
3651  					  size_t offset, size_t size,
3652  					  enum dma_data_direction dir)
3653  {
3654  	return dma_map_page(dev, skb_frag_page(frag),
3655  			    skb_frag_off(frag) + offset, size, dir);
3656  }
3657  
pskb_copy(struct sk_buff * skb,gfp_t gfp_mask)3658  static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
3659  					gfp_t gfp_mask)
3660  {
3661  	return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
3662  }
3663  
3664  
pskb_copy_for_clone(struct sk_buff * skb,gfp_t gfp_mask)3665  static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb,
3666  						  gfp_t gfp_mask)
3667  {
3668  	return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true);
3669  }
3670  
3671  
3672  /**
3673   *	skb_clone_writable - is the header of a clone writable
3674   *	@skb: buffer to check
3675   *	@len: length up to which to write
3676   *
3677   *	Returns true if modifying the header part of the cloned buffer
3678   *	does not requires the data to be copied.
3679   */
skb_clone_writable(const struct sk_buff * skb,unsigned int len)3680  static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
3681  {
3682  	return !skb_header_cloned(skb) &&
3683  	       skb_headroom(skb) + len <= skb->hdr_len;
3684  }
3685  
skb_try_make_writable(struct sk_buff * skb,unsigned int write_len)3686  static inline int skb_try_make_writable(struct sk_buff *skb,
3687  					unsigned int write_len)
3688  {
3689  	return skb_cloned(skb) && !skb_clone_writable(skb, write_len) &&
3690  	       pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
3691  }
3692  
__skb_cow(struct sk_buff * skb,unsigned int headroom,int cloned)3693  static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
3694  			    int cloned)
3695  {
3696  	int delta = 0;
3697  
3698  	if (headroom > skb_headroom(skb))
3699  		delta = headroom - skb_headroom(skb);
3700  
3701  	if (delta || cloned)
3702  		return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
3703  					GFP_ATOMIC);
3704  	return 0;
3705  }
3706  
3707  /**
3708   *	skb_cow - copy header of skb when it is required
3709   *	@skb: buffer to cow
3710   *	@headroom: needed headroom
3711   *
3712   *	If the skb passed lacks sufficient headroom or its data part
3713   *	is shared, data is reallocated. If reallocation fails, an error
3714   *	is returned and original skb is not changed.
3715   *
3716   *	The result is skb with writable area skb->head...skb->tail
3717   *	and at least @headroom of space at head.
3718   */
skb_cow(struct sk_buff * skb,unsigned int headroom)3719  static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
3720  {
3721  	return __skb_cow(skb, headroom, skb_cloned(skb));
3722  }
3723  
3724  /**
3725   *	skb_cow_head - skb_cow but only making the head writable
3726   *	@skb: buffer to cow
3727   *	@headroom: needed headroom
3728   *
3729   *	This function is identical to skb_cow except that we replace the
3730   *	skb_cloned check by skb_header_cloned.  It should be used when
3731   *	you only need to push on some header and do not need to modify
3732   *	the data.
3733   */
skb_cow_head(struct sk_buff * skb,unsigned int headroom)3734  static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
3735  {
3736  	return __skb_cow(skb, headroom, skb_header_cloned(skb));
3737  }
3738  
3739  /**
3740   *	skb_padto	- pad an skbuff up to a minimal size
3741   *	@skb: buffer to pad
3742   *	@len: minimal length
3743   *
3744   *	Pads up a buffer to ensure the trailing bytes exist and are
3745   *	blanked. If the buffer already contains sufficient data it
3746   *	is untouched. Otherwise it is extended. Returns zero on
3747   *	success. The skb is freed on error.
3748   */
skb_padto(struct sk_buff * skb,unsigned int len)3749  static inline int skb_padto(struct sk_buff *skb, unsigned int len)
3750  {
3751  	unsigned int size = skb->len;
3752  	if (likely(size >= len))
3753  		return 0;
3754  	return skb_pad(skb, len - size);
3755  }
3756  
3757  /**
3758   *	__skb_put_padto - increase size and pad an skbuff up to a minimal size
3759   *	@skb: buffer to pad
3760   *	@len: minimal length
3761   *	@free_on_error: free buffer on error
3762   *
3763   *	Pads up a buffer to ensure the trailing bytes exist and are
3764   *	blanked. If the buffer already contains sufficient data it
3765   *	is untouched. Otherwise it is extended. Returns zero on
3766   *	success. The skb is freed on error if @free_on_error is true.
3767   */
__skb_put_padto(struct sk_buff * skb,unsigned int len,bool free_on_error)3768  static inline int __must_check __skb_put_padto(struct sk_buff *skb,
3769  					       unsigned int len,
3770  					       bool free_on_error)
3771  {
3772  	unsigned int size = skb->len;
3773  
3774  	if (unlikely(size < len)) {
3775  		len -= size;
3776  		if (__skb_pad(skb, len, free_on_error))
3777  			return -ENOMEM;
3778  		__skb_put(skb, len);
3779  	}
3780  	return 0;
3781  }
3782  
3783  /**
3784   *	skb_put_padto - increase size and pad an skbuff up to a minimal size
3785   *	@skb: buffer to pad
3786   *	@len: minimal length
3787   *
3788   *	Pads up a buffer to ensure the trailing bytes exist and are
3789   *	blanked. If the buffer already contains sufficient data it
3790   *	is untouched. Otherwise it is extended. Returns zero on
3791   *	success. The skb is freed on error.
3792   */
skb_put_padto(struct sk_buff * skb,unsigned int len)3793  static inline int __must_check skb_put_padto(struct sk_buff *skb, unsigned int len)
3794  {
3795  	return __skb_put_padto(skb, len, true);
3796  }
3797  
3798  bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i)
3799  	__must_check;
3800  
skb_add_data(struct sk_buff * skb,struct iov_iter * from,int copy)3801  static inline int skb_add_data(struct sk_buff *skb,
3802  			       struct iov_iter *from, int copy)
3803  {
3804  	const int off = skb->len;
3805  
3806  	if (skb->ip_summed == CHECKSUM_NONE) {
3807  		__wsum csum = 0;
3808  		if (csum_and_copy_from_iter_full(skb_put(skb, copy), copy,
3809  					         &csum, from)) {
3810  			skb->csum = csum_block_add(skb->csum, csum, off);
3811  			return 0;
3812  		}
3813  	} else if (copy_from_iter_full(skb_put(skb, copy), copy, from))
3814  		return 0;
3815  
3816  	__skb_trim(skb, off);
3817  	return -EFAULT;
3818  }
3819  
skb_can_coalesce(struct sk_buff * skb,int i,const struct page * page,int off)3820  static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
3821  				    const struct page *page, int off)
3822  {
3823  	if (skb_zcopy(skb))
3824  		return false;
3825  	if (i) {
3826  		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1];
3827  
3828  		return page == skb_frag_page(frag) &&
3829  		       off == skb_frag_off(frag) + skb_frag_size(frag);
3830  	}
3831  	return false;
3832  }
3833  
__skb_linearize(struct sk_buff * skb)3834  static inline int __skb_linearize(struct sk_buff *skb)
3835  {
3836  	return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
3837  }
3838  
3839  /**
3840   *	skb_linearize - convert paged skb to linear one
3841   *	@skb: buffer to linarize
3842   *
3843   *	If there is no free memory -ENOMEM is returned, otherwise zero
3844   *	is returned and the old skb data released.
3845   */
skb_linearize(struct sk_buff * skb)3846  static inline int skb_linearize(struct sk_buff *skb)
3847  {
3848  	return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
3849  }
3850  
3851  /**
3852   * skb_has_shared_frag - can any frag be overwritten
3853   * @skb: buffer to test
3854   *
3855   * Return true if the skb has at least one frag that might be modified
3856   * by an external entity (as in vmsplice()/sendfile())
3857   */
skb_has_shared_frag(const struct sk_buff * skb)3858  static inline bool skb_has_shared_frag(const struct sk_buff *skb)
3859  {
3860  	return skb_is_nonlinear(skb) &&
3861  	       skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG;
3862  }
3863  
3864  /**
3865   *	skb_linearize_cow - make sure skb is linear and writable
3866   *	@skb: buffer to process
3867   *
3868   *	If there is no free memory -ENOMEM is returned, otherwise zero
3869   *	is returned and the old skb data released.
3870   */
skb_linearize_cow(struct sk_buff * skb)3871  static inline int skb_linearize_cow(struct sk_buff *skb)
3872  {
3873  	return skb_is_nonlinear(skb) || skb_cloned(skb) ?
3874  	       __skb_linearize(skb) : 0;
3875  }
3876  
3877  static __always_inline void
__skb_postpull_rcsum(struct sk_buff * skb,const void * start,unsigned int len,unsigned int off)3878  __skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
3879  		     unsigned int off)
3880  {
3881  	if (skb->ip_summed == CHECKSUM_COMPLETE)
3882  		skb->csum = csum_block_sub(skb->csum,
3883  					   csum_partial(start, len, 0), off);
3884  	else if (skb->ip_summed == CHECKSUM_PARTIAL &&
3885  		 skb_checksum_start_offset(skb) < 0)
3886  		skb->ip_summed = CHECKSUM_NONE;
3887  }
3888  
3889  /**
3890   *	skb_postpull_rcsum - update checksum for received skb after pull
3891   *	@skb: buffer to update
3892   *	@start: start of data before pull
3893   *	@len: length of data pulled
3894   *
3895   *	After doing a pull on a received packet, you need to call this to
3896   *	update the CHECKSUM_COMPLETE checksum, or set ip_summed to
3897   *	CHECKSUM_NONE so that it can be recomputed from scratch.
3898   */
skb_postpull_rcsum(struct sk_buff * skb,const void * start,unsigned int len)3899  static inline void skb_postpull_rcsum(struct sk_buff *skb,
3900  				      const void *start, unsigned int len)
3901  {
3902  	if (skb->ip_summed == CHECKSUM_COMPLETE)
3903  		skb->csum = wsum_negate(csum_partial(start, len,
3904  						     wsum_negate(skb->csum)));
3905  	else if (skb->ip_summed == CHECKSUM_PARTIAL &&
3906  		 skb_checksum_start_offset(skb) < 0)
3907  		skb->ip_summed = CHECKSUM_NONE;
3908  }
3909  
3910  static __always_inline void
__skb_postpush_rcsum(struct sk_buff * skb,const void * start,unsigned int len,unsigned int off)3911  __skb_postpush_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
3912  		     unsigned int off)
3913  {
3914  	if (skb->ip_summed == CHECKSUM_COMPLETE)
3915  		skb->csum = csum_block_add(skb->csum,
3916  					   csum_partial(start, len, 0), off);
3917  }
3918  
3919  /**
3920   *	skb_postpush_rcsum - update checksum for received skb after push
3921   *	@skb: buffer to update
3922   *	@start: start of data after push
3923   *	@len: length of data pushed
3924   *
3925   *	After doing a push on a received packet, you need to call this to
3926   *	update the CHECKSUM_COMPLETE checksum.
3927   */
skb_postpush_rcsum(struct sk_buff * skb,const void * start,unsigned int len)3928  static inline void skb_postpush_rcsum(struct sk_buff *skb,
3929  				      const void *start, unsigned int len)
3930  {
3931  	__skb_postpush_rcsum(skb, start, len, 0);
3932  }
3933  
3934  void *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
3935  
3936  /**
3937   *	skb_push_rcsum - push skb and update receive checksum
3938   *	@skb: buffer to update
3939   *	@len: length of data pulled
3940   *
3941   *	This function performs an skb_push on the packet and updates
3942   *	the CHECKSUM_COMPLETE checksum.  It should be used on
3943   *	receive path processing instead of skb_push unless you know
3944   *	that the checksum difference is zero (e.g., a valid IP header)
3945   *	or you are setting ip_summed to CHECKSUM_NONE.
3946   */
skb_push_rcsum(struct sk_buff * skb,unsigned int len)3947  static inline void *skb_push_rcsum(struct sk_buff *skb, unsigned int len)
3948  {
3949  	skb_push(skb, len);
3950  	skb_postpush_rcsum(skb, skb->data, len);
3951  	return skb->data;
3952  }
3953  
3954  int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len);
3955  /**
3956   *	pskb_trim_rcsum - trim received skb and update checksum
3957   *	@skb: buffer to trim
3958   *	@len: new length
3959   *
3960   *	This is exactly the same as pskb_trim except that it ensures the
3961   *	checksum of received packets are still valid after the operation.
3962   *	It can change skb pointers.
3963   */
3964  
pskb_trim_rcsum(struct sk_buff * skb,unsigned int len)3965  static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
3966  {
3967  	if (likely(len >= skb->len))
3968  		return 0;
3969  	return pskb_trim_rcsum_slow(skb, len);
3970  }
3971  
__skb_trim_rcsum(struct sk_buff * skb,unsigned int len)3972  static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len)
3973  {
3974  	if (skb->ip_summed == CHECKSUM_COMPLETE)
3975  		skb->ip_summed = CHECKSUM_NONE;
3976  	__skb_trim(skb, len);
3977  	return 0;
3978  }
3979  
__skb_grow_rcsum(struct sk_buff * skb,unsigned int len)3980  static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len)
3981  {
3982  	if (skb->ip_summed == CHECKSUM_COMPLETE)
3983  		skb->ip_summed = CHECKSUM_NONE;
3984  	return __skb_grow(skb, len);
3985  }
3986  
3987  #define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode)
3988  #define skb_rb_first(root) rb_to_skb(rb_first(root))
3989  #define skb_rb_last(root)  rb_to_skb(rb_last(root))
3990  #define skb_rb_next(skb)   rb_to_skb(rb_next(&(skb)->rbnode))
3991  #define skb_rb_prev(skb)   rb_to_skb(rb_prev(&(skb)->rbnode))
3992  
3993  #define skb_queue_walk(queue, skb) \
3994  		for (skb = (queue)->next;					\
3995  		     skb != (struct sk_buff *)(queue);				\
3996  		     skb = skb->next)
3997  
3998  #define skb_queue_walk_safe(queue, skb, tmp)					\
3999  		for (skb = (queue)->next, tmp = skb->next;			\
4000  		     skb != (struct sk_buff *)(queue);				\
4001  		     skb = tmp, tmp = skb->next)
4002  
4003  #define skb_queue_walk_from(queue, skb)						\
4004  		for (; skb != (struct sk_buff *)(queue);			\
4005  		     skb = skb->next)
4006  
4007  #define skb_rbtree_walk(skb, root)						\
4008  		for (skb = skb_rb_first(root); skb != NULL;			\
4009  		     skb = skb_rb_next(skb))
4010  
4011  #define skb_rbtree_walk_from(skb)						\
4012  		for (; skb != NULL;						\
4013  		     skb = skb_rb_next(skb))
4014  
4015  #define skb_rbtree_walk_from_safe(skb, tmp)					\
4016  		for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL);	\
4017  		     skb = tmp)
4018  
4019  #define skb_queue_walk_from_safe(queue, skb, tmp)				\
4020  		for (tmp = skb->next;						\
4021  		     skb != (struct sk_buff *)(queue);				\
4022  		     skb = tmp, tmp = skb->next)
4023  
4024  #define skb_queue_reverse_walk(queue, skb) \
4025  		for (skb = (queue)->prev;					\
4026  		     skb != (struct sk_buff *)(queue);				\
4027  		     skb = skb->prev)
4028  
4029  #define skb_queue_reverse_walk_safe(queue, skb, tmp)				\
4030  		for (skb = (queue)->prev, tmp = skb->prev;			\
4031  		     skb != (struct sk_buff *)(queue);				\
4032  		     skb = tmp, tmp = skb->prev)
4033  
4034  #define skb_queue_reverse_walk_from_safe(queue, skb, tmp)			\
4035  		for (tmp = skb->prev;						\
4036  		     skb != (struct sk_buff *)(queue);				\
4037  		     skb = tmp, tmp = skb->prev)
4038  
skb_has_frag_list(const struct sk_buff * skb)4039  static inline bool skb_has_frag_list(const struct sk_buff *skb)
4040  {
4041  	return skb_shinfo(skb)->frag_list != NULL;
4042  }
4043  
skb_frag_list_init(struct sk_buff * skb)4044  static inline void skb_frag_list_init(struct sk_buff *skb)
4045  {
4046  	skb_shinfo(skb)->frag_list = NULL;
4047  }
4048  
4049  #define skb_walk_frags(skb, iter)	\
4050  	for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
4051  
4052  
4053  int __skb_wait_for_more_packets(struct sock *sk, struct sk_buff_head *queue,
4054  				int *err, long *timeo_p,
4055  				const struct sk_buff *skb);
4056  struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,
4057  					  struct sk_buff_head *queue,
4058  					  unsigned int flags,
4059  					  int *off, int *err,
4060  					  struct sk_buff **last);
4061  struct sk_buff *__skb_try_recv_datagram(struct sock *sk,
4062  					struct sk_buff_head *queue,
4063  					unsigned int flags, int *off, int *err,
4064  					struct sk_buff **last);
4065  struct sk_buff *__skb_recv_datagram(struct sock *sk,
4066  				    struct sk_buff_head *sk_queue,
4067  				    unsigned int flags, int *off, int *err);
4068  struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned int flags, int *err);
4069  __poll_t datagram_poll(struct file *file, struct socket *sock,
4070  			   struct poll_table_struct *wait);
4071  int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
4072  			   struct iov_iter *to, int size);
skb_copy_datagram_msg(const struct sk_buff * from,int offset,struct msghdr * msg,int size)4073  static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset,
4074  					struct msghdr *msg, int size)
4075  {
4076  	return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size);
4077  }
4078  int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
4079  				   struct msghdr *msg);
4080  int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset,
4081  			   struct iov_iter *to, int len,
4082  			   struct ahash_request *hash);
4083  int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
4084  				 struct iov_iter *from, int len);
4085  int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
4086  void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
4087  int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);
4088  int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
4089  int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
4090  __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
4091  			      int len);
4092  int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,
4093  		    struct pipe_inode_info *pipe, unsigned int len,
4094  		    unsigned int flags);
4095  int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset,
4096  			 int len);
4097  int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len);
4098  void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
4099  unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
4100  int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
4101  		 int len, int hlen);
4102  void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
4103  int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
4104  void skb_scrub_packet(struct sk_buff *skb, bool xnet);
4105  struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
4106  struct sk_buff *skb_segment_list(struct sk_buff *skb, netdev_features_t features,
4107  				 unsigned int offset);
4108  struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
4109  int skb_ensure_writable(struct sk_buff *skb, unsigned int write_len);
4110  int skb_ensure_writable_head_tail(struct sk_buff *skb, struct net_device *dev);
4111  int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci);
4112  int skb_vlan_pop(struct sk_buff *skb);
4113  int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
4114  int skb_eth_pop(struct sk_buff *skb);
4115  int skb_eth_push(struct sk_buff *skb, const unsigned char *dst,
4116  		 const unsigned char *src);
4117  int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto,
4118  		  int mac_len, bool ethernet);
4119  int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len,
4120  		 bool ethernet);
4121  int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse);
4122  int skb_mpls_dec_ttl(struct sk_buff *skb);
4123  struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy,
4124  			     gfp_t gfp);
4125  
memcpy_from_msg(void * data,struct msghdr * msg,int len)4126  static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len)
4127  {
4128  	return copy_from_iter_full(data, len, &msg->msg_iter) ? 0 : -EFAULT;
4129  }
4130  
memcpy_to_msg(struct msghdr * msg,void * data,int len)4131  static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len)
4132  {
4133  	return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT;
4134  }
4135  
4136  struct skb_checksum_ops {
4137  	__wsum (*update)(const void *mem, int len, __wsum wsum);
4138  	__wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len);
4139  };
4140  
4141  extern const struct skb_checksum_ops *crc32c_csum_stub __read_mostly;
4142  
4143  __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
4144  		      __wsum csum, const struct skb_checksum_ops *ops);
4145  __wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
4146  		    __wsum csum);
4147  
4148  static inline void * __must_check
__skb_header_pointer(const struct sk_buff * skb,int offset,int len,const void * data,int hlen,void * buffer)4149  __skb_header_pointer(const struct sk_buff *skb, int offset, int len,
4150  		     const void *data, int hlen, void *buffer)
4151  {
4152  	if (likely(hlen - offset >= len))
4153  		return (void *)data + offset;
4154  
4155  	if (!skb || unlikely(skb_copy_bits(skb, offset, buffer, len) < 0))
4156  		return NULL;
4157  
4158  	return buffer;
4159  }
4160  
4161  static inline void * __must_check
skb_header_pointer(const struct sk_buff * skb,int offset,int len,void * buffer)4162  skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer)
4163  {
4164  	return __skb_header_pointer(skb, offset, len, skb->data,
4165  				    skb_headlen(skb), buffer);
4166  }
4167  
4168  static inline void * __must_check
skb_pointer_if_linear(const struct sk_buff * skb,int offset,int len)4169  skb_pointer_if_linear(const struct sk_buff *skb, int offset, int len)
4170  {
4171  	if (likely(skb_headlen(skb) - offset >= len))
4172  		return skb->data + offset;
4173  	return NULL;
4174  }
4175  
4176  /**
4177   *	skb_needs_linearize - check if we need to linearize a given skb
4178   *			      depending on the given device features.
4179   *	@skb: socket buffer to check
4180   *	@features: net device features
4181   *
4182   *	Returns true if either:
4183   *	1. skb has frag_list and the device doesn't support FRAGLIST, or
4184   *	2. skb is fragmented and the device does not support SG.
4185   */
skb_needs_linearize(struct sk_buff * skb,netdev_features_t features)4186  static inline bool skb_needs_linearize(struct sk_buff *skb,
4187  				       netdev_features_t features)
4188  {
4189  	return skb_is_nonlinear(skb) &&
4190  	       ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
4191  		(skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
4192  }
4193  
skb_copy_from_linear_data(const struct sk_buff * skb,void * to,const unsigned int len)4194  static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
4195  					     void *to,
4196  					     const unsigned int len)
4197  {
4198  	memcpy(to, skb->data, len);
4199  }
4200  
skb_copy_from_linear_data_offset(const struct sk_buff * skb,const int offset,void * to,const unsigned int len)4201  static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
4202  						    const int offset, void *to,
4203  						    const unsigned int len)
4204  {
4205  	memcpy(to, skb->data + offset, len);
4206  }
4207  
skb_copy_to_linear_data(struct sk_buff * skb,const void * from,const unsigned int len)4208  static inline void skb_copy_to_linear_data(struct sk_buff *skb,
4209  					   const void *from,
4210  					   const unsigned int len)
4211  {
4212  	memcpy(skb->data, from, len);
4213  }
4214  
skb_copy_to_linear_data_offset(struct sk_buff * skb,const int offset,const void * from,const unsigned int len)4215  static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
4216  						  const int offset,
4217  						  const void *from,
4218  						  const unsigned int len)
4219  {
4220  	memcpy(skb->data + offset, from, len);
4221  }
4222  
4223  void skb_init(void);
4224  
skb_get_ktime(const struct sk_buff * skb)4225  static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
4226  {
4227  	return skb->tstamp;
4228  }
4229  
4230  /**
4231   *	skb_get_timestamp - get timestamp from a skb
4232   *	@skb: skb to get stamp from
4233   *	@stamp: pointer to struct __kernel_old_timeval to store stamp in
4234   *
4235   *	Timestamps are stored in the skb as offsets to a base timestamp.
4236   *	This function converts the offset back to a struct timeval and stores
4237   *	it in stamp.
4238   */
skb_get_timestamp(const struct sk_buff * skb,struct __kernel_old_timeval * stamp)4239  static inline void skb_get_timestamp(const struct sk_buff *skb,
4240  				     struct __kernel_old_timeval *stamp)
4241  {
4242  	*stamp = ns_to_kernel_old_timeval(skb->tstamp);
4243  }
4244  
skb_get_new_timestamp(const struct sk_buff * skb,struct __kernel_sock_timeval * stamp)4245  static inline void skb_get_new_timestamp(const struct sk_buff *skb,
4246  					 struct __kernel_sock_timeval *stamp)
4247  {
4248  	struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4249  
4250  	stamp->tv_sec = ts.tv_sec;
4251  	stamp->tv_usec = ts.tv_nsec / 1000;
4252  }
4253  
skb_get_timestampns(const struct sk_buff * skb,struct __kernel_old_timespec * stamp)4254  static inline void skb_get_timestampns(const struct sk_buff *skb,
4255  				       struct __kernel_old_timespec *stamp)
4256  {
4257  	struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4258  
4259  	stamp->tv_sec = ts.tv_sec;
4260  	stamp->tv_nsec = ts.tv_nsec;
4261  }
4262  
skb_get_new_timestampns(const struct sk_buff * skb,struct __kernel_timespec * stamp)4263  static inline void skb_get_new_timestampns(const struct sk_buff *skb,
4264  					   struct __kernel_timespec *stamp)
4265  {
4266  	struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4267  
4268  	stamp->tv_sec = ts.tv_sec;
4269  	stamp->tv_nsec = ts.tv_nsec;
4270  }
4271  
__net_timestamp(struct sk_buff * skb)4272  static inline void __net_timestamp(struct sk_buff *skb)
4273  {
4274  	skb->tstamp = ktime_get_real();
4275  	skb->tstamp_type = SKB_CLOCK_REALTIME;
4276  }
4277  
net_timedelta(ktime_t t)4278  static inline ktime_t net_timedelta(ktime_t t)
4279  {
4280  	return ktime_sub(ktime_get_real(), t);
4281  }
4282  
skb_set_delivery_time(struct sk_buff * skb,ktime_t kt,u8 tstamp_type)4283  static inline void skb_set_delivery_time(struct sk_buff *skb, ktime_t kt,
4284  					 u8 tstamp_type)
4285  {
4286  	skb->tstamp = kt;
4287  
4288  	if (kt)
4289  		skb->tstamp_type = tstamp_type;
4290  	else
4291  		skb->tstamp_type = SKB_CLOCK_REALTIME;
4292  }
4293  
skb_set_delivery_type_by_clockid(struct sk_buff * skb,ktime_t kt,clockid_t clockid)4294  static inline void skb_set_delivery_type_by_clockid(struct sk_buff *skb,
4295  						    ktime_t kt, clockid_t clockid)
4296  {
4297  	u8 tstamp_type = SKB_CLOCK_REALTIME;
4298  
4299  	switch (clockid) {
4300  	case CLOCK_REALTIME:
4301  		break;
4302  	case CLOCK_MONOTONIC:
4303  		tstamp_type = SKB_CLOCK_MONOTONIC;
4304  		break;
4305  	case CLOCK_TAI:
4306  		tstamp_type = SKB_CLOCK_TAI;
4307  		break;
4308  	default:
4309  		WARN_ON_ONCE(1);
4310  		kt = 0;
4311  	}
4312  
4313  	skb_set_delivery_time(skb, kt, tstamp_type);
4314  }
4315  
4316  DECLARE_STATIC_KEY_FALSE(netstamp_needed_key);
4317  
4318  /* It is used in the ingress path to clear the delivery_time.
4319   * If needed, set the skb->tstamp to the (rcv) timestamp.
4320   */
skb_clear_delivery_time(struct sk_buff * skb)4321  static inline void skb_clear_delivery_time(struct sk_buff *skb)
4322  {
4323  	if (skb->tstamp_type) {
4324  		skb->tstamp_type = SKB_CLOCK_REALTIME;
4325  		if (static_branch_unlikely(&netstamp_needed_key))
4326  			skb->tstamp = ktime_get_real();
4327  		else
4328  			skb->tstamp = 0;
4329  	}
4330  }
4331  
skb_clear_tstamp(struct sk_buff * skb)4332  static inline void skb_clear_tstamp(struct sk_buff *skb)
4333  {
4334  	if (skb->tstamp_type)
4335  		return;
4336  
4337  	skb->tstamp = 0;
4338  }
4339  
skb_tstamp(const struct sk_buff * skb)4340  static inline ktime_t skb_tstamp(const struct sk_buff *skb)
4341  {
4342  	if (skb->tstamp_type)
4343  		return 0;
4344  
4345  	return skb->tstamp;
4346  }
4347  
skb_tstamp_cond(const struct sk_buff * skb,bool cond)4348  static inline ktime_t skb_tstamp_cond(const struct sk_buff *skb, bool cond)
4349  {
4350  	if (skb->tstamp_type != SKB_CLOCK_MONOTONIC && skb->tstamp)
4351  		return skb->tstamp;
4352  
4353  	if (static_branch_unlikely(&netstamp_needed_key) || cond)
4354  		return ktime_get_real();
4355  
4356  	return 0;
4357  }
4358  
skb_metadata_len(const struct sk_buff * skb)4359  static inline u8 skb_metadata_len(const struct sk_buff *skb)
4360  {
4361  	return skb_shinfo(skb)->meta_len;
4362  }
4363  
skb_metadata_end(const struct sk_buff * skb)4364  static inline void *skb_metadata_end(const struct sk_buff *skb)
4365  {
4366  	return skb_mac_header(skb);
4367  }
4368  
__skb_metadata_differs(const struct sk_buff * skb_a,const struct sk_buff * skb_b,u8 meta_len)4369  static inline bool __skb_metadata_differs(const struct sk_buff *skb_a,
4370  					  const struct sk_buff *skb_b,
4371  					  u8 meta_len)
4372  {
4373  	const void *a = skb_metadata_end(skb_a);
4374  	const void *b = skb_metadata_end(skb_b);
4375  	u64 diffs = 0;
4376  
4377  	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) ||
4378  	    BITS_PER_LONG != 64)
4379  		goto slow;
4380  
4381  	/* Using more efficient variant than plain call to memcmp(). */
4382  	switch (meta_len) {
4383  #define __it(x, op) (x -= sizeof(u##op))
4384  #define __it_diff(a, b, op) (*(u##op *)__it(a, op)) ^ (*(u##op *)__it(b, op))
4385  	case 32: diffs |= __it_diff(a, b, 64);
4386  		fallthrough;
4387  	case 24: diffs |= __it_diff(a, b, 64);
4388  		fallthrough;
4389  	case 16: diffs |= __it_diff(a, b, 64);
4390  		fallthrough;
4391  	case  8: diffs |= __it_diff(a, b, 64);
4392  		break;
4393  	case 28: diffs |= __it_diff(a, b, 64);
4394  		fallthrough;
4395  	case 20: diffs |= __it_diff(a, b, 64);
4396  		fallthrough;
4397  	case 12: diffs |= __it_diff(a, b, 64);
4398  		fallthrough;
4399  	case  4: diffs |= __it_diff(a, b, 32);
4400  		break;
4401  	default:
4402  slow:
4403  		return memcmp(a - meta_len, b - meta_len, meta_len);
4404  	}
4405  	return diffs;
4406  }
4407  
skb_metadata_differs(const struct sk_buff * skb_a,const struct sk_buff * skb_b)4408  static inline bool skb_metadata_differs(const struct sk_buff *skb_a,
4409  					const struct sk_buff *skb_b)
4410  {
4411  	u8 len_a = skb_metadata_len(skb_a);
4412  	u8 len_b = skb_metadata_len(skb_b);
4413  
4414  	if (!(len_a | len_b))
4415  		return false;
4416  
4417  	return len_a != len_b ?
4418  	       true : __skb_metadata_differs(skb_a, skb_b, len_a);
4419  }
4420  
skb_metadata_set(struct sk_buff * skb,u8 meta_len)4421  static inline void skb_metadata_set(struct sk_buff *skb, u8 meta_len)
4422  {
4423  	skb_shinfo(skb)->meta_len = meta_len;
4424  }
4425  
skb_metadata_clear(struct sk_buff * skb)4426  static inline void skb_metadata_clear(struct sk_buff *skb)
4427  {
4428  	skb_metadata_set(skb, 0);
4429  }
4430  
4431  struct sk_buff *skb_clone_sk(struct sk_buff *skb);
4432  
4433  #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
4434  
4435  void skb_clone_tx_timestamp(struct sk_buff *skb);
4436  bool skb_defer_rx_timestamp(struct sk_buff *skb);
4437  
4438  #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
4439  
skb_clone_tx_timestamp(struct sk_buff * skb)4440  static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
4441  {
4442  }
4443  
skb_defer_rx_timestamp(struct sk_buff * skb)4444  static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
4445  {
4446  	return false;
4447  }
4448  
4449  #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
4450  
4451  /**
4452   * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
4453   *
4454   * PHY drivers may accept clones of transmitted packets for
4455   * timestamping via their phy_driver.txtstamp method. These drivers
4456   * must call this function to return the skb back to the stack with a
4457   * timestamp.
4458   *
4459   * @skb: clone of the original outgoing packet
4460   * @hwtstamps: hardware time stamps
4461   *
4462   */
4463  void skb_complete_tx_timestamp(struct sk_buff *skb,
4464  			       struct skb_shared_hwtstamps *hwtstamps);
4465  
4466  void __skb_tstamp_tx(struct sk_buff *orig_skb, const struct sk_buff *ack_skb,
4467  		     struct skb_shared_hwtstamps *hwtstamps,
4468  		     struct sock *sk, int tstype);
4469  
4470  /**
4471   * skb_tstamp_tx - queue clone of skb with send time stamps
4472   * @orig_skb:	the original outgoing packet
4473   * @hwtstamps:	hardware time stamps, may be NULL if not available
4474   *
4475   * If the skb has a socket associated, then this function clones the
4476   * skb (thus sharing the actual data and optional structures), stores
4477   * the optional hardware time stamping information (if non NULL) or
4478   * generates a software time stamp (otherwise), then queues the clone
4479   * to the error queue of the socket.  Errors are silently ignored.
4480   */
4481  void skb_tstamp_tx(struct sk_buff *orig_skb,
4482  		   struct skb_shared_hwtstamps *hwtstamps);
4483  
4484  /**
4485   * skb_tx_timestamp() - Driver hook for transmit timestamping
4486   *
4487   * Ethernet MAC Drivers should call this function in their hard_xmit()
4488   * function immediately before giving the sk_buff to the MAC hardware.
4489   *
4490   * Specifically, one should make absolutely sure that this function is
4491   * called before TX completion of this packet can trigger.  Otherwise
4492   * the packet could potentially already be freed.
4493   *
4494   * @skb: A socket buffer.
4495   */
skb_tx_timestamp(struct sk_buff * skb)4496  static inline void skb_tx_timestamp(struct sk_buff *skb)
4497  {
4498  	skb_clone_tx_timestamp(skb);
4499  	if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP)
4500  		skb_tstamp_tx(skb, NULL);
4501  }
4502  
4503  /**
4504   * skb_complete_wifi_ack - deliver skb with wifi status
4505   *
4506   * @skb: the original outgoing packet
4507   * @acked: ack status
4508   *
4509   */
4510  void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
4511  
4512  __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
4513  __sum16 __skb_checksum_complete(struct sk_buff *skb);
4514  
skb_csum_unnecessary(const struct sk_buff * skb)4515  static inline int skb_csum_unnecessary(const struct sk_buff *skb)
4516  {
4517  	return ((skb->ip_summed == CHECKSUM_UNNECESSARY) ||
4518  		skb->csum_valid ||
4519  		(skb->ip_summed == CHECKSUM_PARTIAL &&
4520  		 skb_checksum_start_offset(skb) >= 0));
4521  }
4522  
4523  /**
4524   *	skb_checksum_complete - Calculate checksum of an entire packet
4525   *	@skb: packet to process
4526   *
4527   *	This function calculates the checksum over the entire packet plus
4528   *	the value of skb->csum.  The latter can be used to supply the
4529   *	checksum of a pseudo header as used by TCP/UDP.  It returns the
4530   *	checksum.
4531   *
4532   *	For protocols that contain complete checksums such as ICMP/TCP/UDP,
4533   *	this function can be used to verify that checksum on received
4534   *	packets.  In that case the function should return zero if the
4535   *	checksum is correct.  In particular, this function will return zero
4536   *	if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
4537   *	hardware has already verified the correctness of the checksum.
4538   */
skb_checksum_complete(struct sk_buff * skb)4539  static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
4540  {
4541  	return skb_csum_unnecessary(skb) ?
4542  	       0 : __skb_checksum_complete(skb);
4543  }
4544  
__skb_decr_checksum_unnecessary(struct sk_buff * skb)4545  static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb)
4546  {
4547  	if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4548  		if (skb->csum_level == 0)
4549  			skb->ip_summed = CHECKSUM_NONE;
4550  		else
4551  			skb->csum_level--;
4552  	}
4553  }
4554  
__skb_incr_checksum_unnecessary(struct sk_buff * skb)4555  static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb)
4556  {
4557  	if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4558  		if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
4559  			skb->csum_level++;
4560  	} else if (skb->ip_summed == CHECKSUM_NONE) {
4561  		skb->ip_summed = CHECKSUM_UNNECESSARY;
4562  		skb->csum_level = 0;
4563  	}
4564  }
4565  
__skb_reset_checksum_unnecessary(struct sk_buff * skb)4566  static inline void __skb_reset_checksum_unnecessary(struct sk_buff *skb)
4567  {
4568  	if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4569  		skb->ip_summed = CHECKSUM_NONE;
4570  		skb->csum_level = 0;
4571  	}
4572  }
4573  
4574  /* Check if we need to perform checksum complete validation.
4575   *
4576   * Returns true if checksum complete is needed, false otherwise
4577   * (either checksum is unnecessary or zero checksum is allowed).
4578   */
__skb_checksum_validate_needed(struct sk_buff * skb,bool zero_okay,__sum16 check)4579  static inline bool __skb_checksum_validate_needed(struct sk_buff *skb,
4580  						  bool zero_okay,
4581  						  __sum16 check)
4582  {
4583  	if (skb_csum_unnecessary(skb) || (zero_okay && !check)) {
4584  		skb->csum_valid = 1;
4585  		__skb_decr_checksum_unnecessary(skb);
4586  		return false;
4587  	}
4588  
4589  	return true;
4590  }
4591  
4592  /* For small packets <= CHECKSUM_BREAK perform checksum complete directly
4593   * in checksum_init.
4594   */
4595  #define CHECKSUM_BREAK 76
4596  
4597  /* Unset checksum-complete
4598   *
4599   * Unset checksum complete can be done when packet is being modified
4600   * (uncompressed for instance) and checksum-complete value is
4601   * invalidated.
4602   */
skb_checksum_complete_unset(struct sk_buff * skb)4603  static inline void skb_checksum_complete_unset(struct sk_buff *skb)
4604  {
4605  	if (skb->ip_summed == CHECKSUM_COMPLETE)
4606  		skb->ip_summed = CHECKSUM_NONE;
4607  }
4608  
4609  /* Validate (init) checksum based on checksum complete.
4610   *
4611   * Return values:
4612   *   0: checksum is validated or try to in skb_checksum_complete. In the latter
4613   *	case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
4614   *	checksum is stored in skb->csum for use in __skb_checksum_complete
4615   *   non-zero: value of invalid checksum
4616   *
4617   */
__skb_checksum_validate_complete(struct sk_buff * skb,bool complete,__wsum psum)4618  static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
4619  						       bool complete,
4620  						       __wsum psum)
4621  {
4622  	if (skb->ip_summed == CHECKSUM_COMPLETE) {
4623  		if (!csum_fold(csum_add(psum, skb->csum))) {
4624  			skb->csum_valid = 1;
4625  			return 0;
4626  		}
4627  	}
4628  
4629  	skb->csum = psum;
4630  
4631  	if (complete || skb->len <= CHECKSUM_BREAK) {
4632  		__sum16 csum;
4633  
4634  		csum = __skb_checksum_complete(skb);
4635  		skb->csum_valid = !csum;
4636  		return csum;
4637  	}
4638  
4639  	return 0;
4640  }
4641  
null_compute_pseudo(struct sk_buff * skb,int proto)4642  static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)
4643  {
4644  	return 0;
4645  }
4646  
4647  /* Perform checksum validate (init). Note that this is a macro since we only
4648   * want to calculate the pseudo header which is an input function if necessary.
4649   * First we try to validate without any computation (checksum unnecessary) and
4650   * then calculate based on checksum complete calling the function to compute
4651   * pseudo header.
4652   *
4653   * Return values:
4654   *   0: checksum is validated or try to in skb_checksum_complete
4655   *   non-zero: value of invalid checksum
4656   */
4657  #define __skb_checksum_validate(skb, proto, complete,			\
4658  				zero_okay, check, compute_pseudo)	\
4659  ({									\
4660  	__sum16 __ret = 0;						\
4661  	skb->csum_valid = 0;						\
4662  	if (__skb_checksum_validate_needed(skb, zero_okay, check))	\
4663  		__ret = __skb_checksum_validate_complete(skb,		\
4664  				complete, compute_pseudo(skb, proto));	\
4665  	__ret;								\
4666  })
4667  
4668  #define skb_checksum_init(skb, proto, compute_pseudo)			\
4669  	__skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
4670  
4671  #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo)	\
4672  	__skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
4673  
4674  #define skb_checksum_validate(skb, proto, compute_pseudo)		\
4675  	__skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
4676  
4677  #define skb_checksum_validate_zero_check(skb, proto, check,		\
4678  					 compute_pseudo)		\
4679  	__skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
4680  
4681  #define skb_checksum_simple_validate(skb)				\
4682  	__skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
4683  
__skb_checksum_convert_check(struct sk_buff * skb)4684  static inline bool __skb_checksum_convert_check(struct sk_buff *skb)
4685  {
4686  	return (skb->ip_summed == CHECKSUM_NONE && skb->csum_valid);
4687  }
4688  
__skb_checksum_convert(struct sk_buff * skb,__wsum pseudo)4689  static inline void __skb_checksum_convert(struct sk_buff *skb, __wsum pseudo)
4690  {
4691  	skb->csum = ~pseudo;
4692  	skb->ip_summed = CHECKSUM_COMPLETE;
4693  }
4694  
4695  #define skb_checksum_try_convert(skb, proto, compute_pseudo)	\
4696  do {									\
4697  	if (__skb_checksum_convert_check(skb))				\
4698  		__skb_checksum_convert(skb, compute_pseudo(skb, proto)); \
4699  } while (0)
4700  
skb_remcsum_adjust_partial(struct sk_buff * skb,void * ptr,u16 start,u16 offset)4701  static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr,
4702  					      u16 start, u16 offset)
4703  {
4704  	skb->ip_summed = CHECKSUM_PARTIAL;
4705  	skb->csum_start = ((unsigned char *)ptr + start) - skb->head;
4706  	skb->csum_offset = offset - start;
4707  }
4708  
4709  /* Update skbuf and packet to reflect the remote checksum offload operation.
4710   * When called, ptr indicates the starting point for skb->csum when
4711   * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
4712   * here, skb_postpull_rcsum is done so skb->csum start is ptr.
4713   */
skb_remcsum_process(struct sk_buff * skb,void * ptr,int start,int offset,bool nopartial)4714  static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr,
4715  				       int start, int offset, bool nopartial)
4716  {
4717  	__wsum delta;
4718  
4719  	if (!nopartial) {
4720  		skb_remcsum_adjust_partial(skb, ptr, start, offset);
4721  		return;
4722  	}
4723  
4724  	if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) {
4725  		__skb_checksum_complete(skb);
4726  		skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data);
4727  	}
4728  
4729  	delta = remcsum_adjust(ptr, skb->csum, start, offset);
4730  
4731  	/* Adjust skb->csum since we changed the packet */
4732  	skb->csum = csum_add(skb->csum, delta);
4733  }
4734  
skb_nfct(const struct sk_buff * skb)4735  static inline struct nf_conntrack *skb_nfct(const struct sk_buff *skb)
4736  {
4737  #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4738  	return (void *)(skb->_nfct & NFCT_PTRMASK);
4739  #else
4740  	return NULL;
4741  #endif
4742  }
4743  
skb_get_nfct(const struct sk_buff * skb)4744  static inline unsigned long skb_get_nfct(const struct sk_buff *skb)
4745  {
4746  #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4747  	return skb->_nfct;
4748  #else
4749  	return 0UL;
4750  #endif
4751  }
4752  
skb_set_nfct(struct sk_buff * skb,unsigned long nfct)4753  static inline void skb_set_nfct(struct sk_buff *skb, unsigned long nfct)
4754  {
4755  #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4756  	skb->slow_gro |= !!nfct;
4757  	skb->_nfct = nfct;
4758  #endif
4759  }
4760  
4761  #ifdef CONFIG_SKB_EXTENSIONS
4762  enum skb_ext_id {
4763  #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
4764  	SKB_EXT_BRIDGE_NF,
4765  #endif
4766  #ifdef CONFIG_XFRM
4767  	SKB_EXT_SEC_PATH,
4768  #endif
4769  #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
4770  	TC_SKB_EXT,
4771  #endif
4772  #if IS_ENABLED(CONFIG_MPTCP)
4773  	SKB_EXT_MPTCP,
4774  #endif
4775  #if IS_ENABLED(CONFIG_MCTP_FLOWS)
4776  	SKB_EXT_MCTP,
4777  #endif
4778  	SKB_EXT_NUM, /* must be last */
4779  };
4780  
4781  /**
4782   *	struct skb_ext - sk_buff extensions
4783   *	@refcnt: 1 on allocation, deallocated on 0
4784   *	@offset: offset to add to @data to obtain extension address
4785   *	@chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units
4786   *	@data: start of extension data, variable sized
4787   *
4788   *	Note: offsets/lengths are stored in chunks of 8 bytes, this allows
4789   *	to use 'u8' types while allowing up to 2kb worth of extension data.
4790   */
4791  struct skb_ext {
4792  	refcount_t refcnt;
4793  	u8 offset[SKB_EXT_NUM]; /* in chunks of 8 bytes */
4794  	u8 chunks;		/* same */
4795  	char data[] __aligned(8);
4796  };
4797  
4798  struct skb_ext *__skb_ext_alloc(gfp_t flags);
4799  void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id,
4800  		    struct skb_ext *ext);
4801  void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id);
4802  void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id);
4803  void __skb_ext_put(struct skb_ext *ext);
4804  
skb_ext_put(struct sk_buff * skb)4805  static inline void skb_ext_put(struct sk_buff *skb)
4806  {
4807  	if (skb->active_extensions)
4808  		__skb_ext_put(skb->extensions);
4809  }
4810  
__skb_ext_copy(struct sk_buff * dst,const struct sk_buff * src)4811  static inline void __skb_ext_copy(struct sk_buff *dst,
4812  				  const struct sk_buff *src)
4813  {
4814  	dst->active_extensions = src->active_extensions;
4815  
4816  	if (src->active_extensions) {
4817  		struct skb_ext *ext = src->extensions;
4818  
4819  		refcount_inc(&ext->refcnt);
4820  		dst->extensions = ext;
4821  	}
4822  }
4823  
skb_ext_copy(struct sk_buff * dst,const struct sk_buff * src)4824  static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *src)
4825  {
4826  	skb_ext_put(dst);
4827  	__skb_ext_copy(dst, src);
4828  }
4829  
__skb_ext_exist(const struct skb_ext * ext,enum skb_ext_id i)4830  static inline bool __skb_ext_exist(const struct skb_ext *ext, enum skb_ext_id i)
4831  {
4832  	return !!ext->offset[i];
4833  }
4834  
skb_ext_exist(const struct sk_buff * skb,enum skb_ext_id id)4835  static inline bool skb_ext_exist(const struct sk_buff *skb, enum skb_ext_id id)
4836  {
4837  	return skb->active_extensions & (1 << id);
4838  }
4839  
skb_ext_del(struct sk_buff * skb,enum skb_ext_id id)4840  static inline void skb_ext_del(struct sk_buff *skb, enum skb_ext_id id)
4841  {
4842  	if (skb_ext_exist(skb, id))
4843  		__skb_ext_del(skb, id);
4844  }
4845  
skb_ext_find(const struct sk_buff * skb,enum skb_ext_id id)4846  static inline void *skb_ext_find(const struct sk_buff *skb, enum skb_ext_id id)
4847  {
4848  	if (skb_ext_exist(skb, id)) {
4849  		struct skb_ext *ext = skb->extensions;
4850  
4851  		return (void *)ext + (ext->offset[id] << 3);
4852  	}
4853  
4854  	return NULL;
4855  }
4856  
skb_ext_reset(struct sk_buff * skb)4857  static inline void skb_ext_reset(struct sk_buff *skb)
4858  {
4859  	if (unlikely(skb->active_extensions)) {
4860  		__skb_ext_put(skb->extensions);
4861  		skb->active_extensions = 0;
4862  	}
4863  }
4864  
skb_has_extensions(struct sk_buff * skb)4865  static inline bool skb_has_extensions(struct sk_buff *skb)
4866  {
4867  	return unlikely(skb->active_extensions);
4868  }
4869  #else
skb_ext_put(struct sk_buff * skb)4870  static inline void skb_ext_put(struct sk_buff *skb) {}
skb_ext_reset(struct sk_buff * skb)4871  static inline void skb_ext_reset(struct sk_buff *skb) {}
skb_ext_del(struct sk_buff * skb,int unused)4872  static inline void skb_ext_del(struct sk_buff *skb, int unused) {}
__skb_ext_copy(struct sk_buff * d,const struct sk_buff * s)4873  static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {}
skb_ext_copy(struct sk_buff * dst,const struct sk_buff * s)4874  static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {}
skb_has_extensions(struct sk_buff * skb)4875  static inline bool skb_has_extensions(struct sk_buff *skb) { return false; }
4876  #endif /* CONFIG_SKB_EXTENSIONS */
4877  
nf_reset_ct(struct sk_buff * skb)4878  static inline void nf_reset_ct(struct sk_buff *skb)
4879  {
4880  #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4881  	nf_conntrack_put(skb_nfct(skb));
4882  	skb->_nfct = 0;
4883  #endif
4884  }
4885  
nf_reset_trace(struct sk_buff * skb)4886  static inline void nf_reset_trace(struct sk_buff *skb)
4887  {
4888  #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES)
4889  	skb->nf_trace = 0;
4890  #endif
4891  }
4892  
ipvs_reset(struct sk_buff * skb)4893  static inline void ipvs_reset(struct sk_buff *skb)
4894  {
4895  #if IS_ENABLED(CONFIG_IP_VS)
4896  	skb->ipvs_property = 0;
4897  #endif
4898  }
4899  
4900  /* Note: This doesn't put any conntrack info in dst. */
__nf_copy(struct sk_buff * dst,const struct sk_buff * src,bool copy)4901  static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src,
4902  			     bool copy)
4903  {
4904  #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4905  	dst->_nfct = src->_nfct;
4906  	nf_conntrack_get(skb_nfct(src));
4907  #endif
4908  #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES)
4909  	if (copy)
4910  		dst->nf_trace = src->nf_trace;
4911  #endif
4912  }
4913  
nf_copy(struct sk_buff * dst,const struct sk_buff * src)4914  static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
4915  {
4916  #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4917  	nf_conntrack_put(skb_nfct(dst));
4918  #endif
4919  	dst->slow_gro = src->slow_gro;
4920  	__nf_copy(dst, src, true);
4921  }
4922  
4923  #ifdef CONFIG_NETWORK_SECMARK
skb_copy_secmark(struct sk_buff * to,const struct sk_buff * from)4924  static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
4925  {
4926  	to->secmark = from->secmark;
4927  }
4928  
skb_init_secmark(struct sk_buff * skb)4929  static inline void skb_init_secmark(struct sk_buff *skb)
4930  {
4931  	skb->secmark = 0;
4932  }
4933  #else
skb_copy_secmark(struct sk_buff * to,const struct sk_buff * from)4934  static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
4935  { }
4936  
skb_init_secmark(struct sk_buff * skb)4937  static inline void skb_init_secmark(struct sk_buff *skb)
4938  { }
4939  #endif
4940  
secpath_exists(const struct sk_buff * skb)4941  static inline int secpath_exists(const struct sk_buff *skb)
4942  {
4943  #ifdef CONFIG_XFRM
4944  	return skb_ext_exist(skb, SKB_EXT_SEC_PATH);
4945  #else
4946  	return 0;
4947  #endif
4948  }
4949  
skb_irq_freeable(const struct sk_buff * skb)4950  static inline bool skb_irq_freeable(const struct sk_buff *skb)
4951  {
4952  	return !skb->destructor &&
4953  		!secpath_exists(skb) &&
4954  		!skb_nfct(skb) &&
4955  		!skb->_skb_refdst &&
4956  		!skb_has_frag_list(skb);
4957  }
4958  
skb_set_queue_mapping(struct sk_buff * skb,u16 queue_mapping)4959  static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
4960  {
4961  	skb->queue_mapping = queue_mapping;
4962  }
4963  
skb_get_queue_mapping(const struct sk_buff * skb)4964  static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
4965  {
4966  	return skb->queue_mapping;
4967  }
4968  
skb_copy_queue_mapping(struct sk_buff * to,const struct sk_buff * from)4969  static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
4970  {
4971  	to->queue_mapping = from->queue_mapping;
4972  }
4973  
skb_record_rx_queue(struct sk_buff * skb,u16 rx_queue)4974  static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
4975  {
4976  	skb->queue_mapping = rx_queue + 1;
4977  }
4978  
skb_get_rx_queue(const struct sk_buff * skb)4979  static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
4980  {
4981  	return skb->queue_mapping - 1;
4982  }
4983  
skb_rx_queue_recorded(const struct sk_buff * skb)4984  static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
4985  {
4986  	return skb->queue_mapping != 0;
4987  }
4988  
skb_set_dst_pending_confirm(struct sk_buff * skb,u32 val)4989  static inline void skb_set_dst_pending_confirm(struct sk_buff *skb, u32 val)
4990  {
4991  	skb->dst_pending_confirm = val;
4992  }
4993  
skb_get_dst_pending_confirm(const struct sk_buff * skb)4994  static inline bool skb_get_dst_pending_confirm(const struct sk_buff *skb)
4995  {
4996  	return skb->dst_pending_confirm != 0;
4997  }
4998  
skb_sec_path(const struct sk_buff * skb)4999  static inline struct sec_path *skb_sec_path(const struct sk_buff *skb)
5000  {
5001  #ifdef CONFIG_XFRM
5002  	return skb_ext_find(skb, SKB_EXT_SEC_PATH);
5003  #else
5004  	return NULL;
5005  #endif
5006  }
5007  
skb_is_gso(const struct sk_buff * skb)5008  static inline bool skb_is_gso(const struct sk_buff *skb)
5009  {
5010  	return skb_shinfo(skb)->gso_size;
5011  }
5012  
5013  /* Note: Should be called only if skb_is_gso(skb) is true */
skb_is_gso_v6(const struct sk_buff * skb)5014  static inline bool skb_is_gso_v6(const struct sk_buff *skb)
5015  {
5016  	return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
5017  }
5018  
5019  /* Note: Should be called only if skb_is_gso(skb) is true */
skb_is_gso_sctp(const struct sk_buff * skb)5020  static inline bool skb_is_gso_sctp(const struct sk_buff *skb)
5021  {
5022  	return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP;
5023  }
5024  
5025  /* Note: Should be called only if skb_is_gso(skb) is true */
skb_is_gso_tcp(const struct sk_buff * skb)5026  static inline bool skb_is_gso_tcp(const struct sk_buff *skb)
5027  {
5028  	return skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6);
5029  }
5030  
skb_gso_reset(struct sk_buff * skb)5031  static inline void skb_gso_reset(struct sk_buff *skb)
5032  {
5033  	skb_shinfo(skb)->gso_size = 0;
5034  	skb_shinfo(skb)->gso_segs = 0;
5035  	skb_shinfo(skb)->gso_type = 0;
5036  }
5037  
skb_increase_gso_size(struct skb_shared_info * shinfo,u16 increment)5038  static inline void skb_increase_gso_size(struct skb_shared_info *shinfo,
5039  					 u16 increment)
5040  {
5041  	if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
5042  		return;
5043  	shinfo->gso_size += increment;
5044  }
5045  
skb_decrease_gso_size(struct skb_shared_info * shinfo,u16 decrement)5046  static inline void skb_decrease_gso_size(struct skb_shared_info *shinfo,
5047  					 u16 decrement)
5048  {
5049  	if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
5050  		return;
5051  	shinfo->gso_size -= decrement;
5052  }
5053  
5054  void __skb_warn_lro_forwarding(const struct sk_buff *skb);
5055  
skb_warn_if_lro(const struct sk_buff * skb)5056  static inline bool skb_warn_if_lro(const struct sk_buff *skb)
5057  {
5058  	/* LRO sets gso_size but not gso_type, whereas if GSO is really
5059  	 * wanted then gso_type will be set. */
5060  	const struct skb_shared_info *shinfo = skb_shinfo(skb);
5061  
5062  	if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
5063  	    unlikely(shinfo->gso_type == 0)) {
5064  		__skb_warn_lro_forwarding(skb);
5065  		return true;
5066  	}
5067  	return false;
5068  }
5069  
skb_forward_csum(struct sk_buff * skb)5070  static inline void skb_forward_csum(struct sk_buff *skb)
5071  {
5072  	/* Unfortunately we don't support this one.  Any brave souls? */
5073  	if (skb->ip_summed == CHECKSUM_COMPLETE)
5074  		skb->ip_summed = CHECKSUM_NONE;
5075  }
5076  
5077  /**
5078   * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
5079   * @skb: skb to check
5080   *
5081   * fresh skbs have their ip_summed set to CHECKSUM_NONE.
5082   * Instead of forcing ip_summed to CHECKSUM_NONE, we can
5083   * use this helper, to document places where we make this assertion.
5084   */
skb_checksum_none_assert(const struct sk_buff * skb)5085  static inline void skb_checksum_none_assert(const struct sk_buff *skb)
5086  {
5087  	DEBUG_NET_WARN_ON_ONCE(skb->ip_summed != CHECKSUM_NONE);
5088  }
5089  
5090  bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
5091  
5092  int skb_checksum_setup(struct sk_buff *skb, bool recalculate);
5093  struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb,
5094  				     unsigned int transport_len,
5095  				     __sum16(*skb_chkf)(struct sk_buff *skb));
5096  
5097  /**
5098   * skb_head_is_locked - Determine if the skb->head is locked down
5099   * @skb: skb to check
5100   *
5101   * The head on skbs build around a head frag can be removed if they are
5102   * not cloned.  This function returns true if the skb head is locked down
5103   * due to either being allocated via kmalloc, or by being a clone with
5104   * multiple references to the head.
5105   */
skb_head_is_locked(const struct sk_buff * skb)5106  static inline bool skb_head_is_locked(const struct sk_buff *skb)
5107  {
5108  	return !skb->head_frag || skb_cloned(skb);
5109  }
5110  
5111  /* Local Checksum Offload.
5112   * Compute outer checksum based on the assumption that the
5113   * inner checksum will be offloaded later.
5114   * See Documentation/networking/checksum-offloads.rst for
5115   * explanation of how this works.
5116   * Fill in outer checksum adjustment (e.g. with sum of outer
5117   * pseudo-header) before calling.
5118   * Also ensure that inner checksum is in linear data area.
5119   */
lco_csum(struct sk_buff * skb)5120  static inline __wsum lco_csum(struct sk_buff *skb)
5121  {
5122  	unsigned char *csum_start = skb_checksum_start(skb);
5123  	unsigned char *l4_hdr = skb_transport_header(skb);
5124  	__wsum partial;
5125  
5126  	/* Start with complement of inner checksum adjustment */
5127  	partial = ~csum_unfold(*(__force __sum16 *)(csum_start +
5128  						    skb->csum_offset));
5129  
5130  	/* Add in checksum of our headers (incl. outer checksum
5131  	 * adjustment filled in by caller) and return result.
5132  	 */
5133  	return csum_partial(l4_hdr, csum_start - l4_hdr, partial);
5134  }
5135  
skb_is_redirected(const struct sk_buff * skb)5136  static inline bool skb_is_redirected(const struct sk_buff *skb)
5137  {
5138  	return skb->redirected;
5139  }
5140  
skb_set_redirected(struct sk_buff * skb,bool from_ingress)5141  static inline void skb_set_redirected(struct sk_buff *skb, bool from_ingress)
5142  {
5143  	skb->redirected = 1;
5144  #ifdef CONFIG_NET_REDIRECT
5145  	skb->from_ingress = from_ingress;
5146  	if (skb->from_ingress)
5147  		skb_clear_tstamp(skb);
5148  #endif
5149  }
5150  
skb_reset_redirect(struct sk_buff * skb)5151  static inline void skb_reset_redirect(struct sk_buff *skb)
5152  {
5153  	skb->redirected = 0;
5154  }
5155  
skb_set_redirected_noclear(struct sk_buff * skb,bool from_ingress)5156  static inline void skb_set_redirected_noclear(struct sk_buff *skb,
5157  					      bool from_ingress)
5158  {
5159  	skb->redirected = 1;
5160  #ifdef CONFIG_NET_REDIRECT
5161  	skb->from_ingress = from_ingress;
5162  #endif
5163  }
5164  
skb_csum_is_sctp(struct sk_buff * skb)5165  static inline bool skb_csum_is_sctp(struct sk_buff *skb)
5166  {
5167  #if IS_ENABLED(CONFIG_IP_SCTP)
5168  	return skb->csum_not_inet;
5169  #else
5170  	return 0;
5171  #endif
5172  }
5173  
skb_reset_csum_not_inet(struct sk_buff * skb)5174  static inline void skb_reset_csum_not_inet(struct sk_buff *skb)
5175  {
5176  	skb->ip_summed = CHECKSUM_NONE;
5177  #if IS_ENABLED(CONFIG_IP_SCTP)
5178  	skb->csum_not_inet = 0;
5179  #endif
5180  }
5181  
skb_set_kcov_handle(struct sk_buff * skb,const u64 kcov_handle)5182  static inline void skb_set_kcov_handle(struct sk_buff *skb,
5183  				       const u64 kcov_handle)
5184  {
5185  #ifdef CONFIG_KCOV
5186  	skb->kcov_handle = kcov_handle;
5187  #endif
5188  }
5189  
skb_get_kcov_handle(struct sk_buff * skb)5190  static inline u64 skb_get_kcov_handle(struct sk_buff *skb)
5191  {
5192  #ifdef CONFIG_KCOV
5193  	return skb->kcov_handle;
5194  #else
5195  	return 0;
5196  #endif
5197  }
5198  
skb_mark_for_recycle(struct sk_buff * skb)5199  static inline void skb_mark_for_recycle(struct sk_buff *skb)
5200  {
5201  #ifdef CONFIG_PAGE_POOL
5202  	skb->pp_recycle = 1;
5203  #endif
5204  }
5205  
5206  ssize_t skb_splice_from_iter(struct sk_buff *skb, struct iov_iter *iter,
5207  			     ssize_t maxsize, gfp_t gfp);
5208  
5209  #endif	/* __KERNEL__ */
5210  #endif	/* _LINUX_SKBUFF_H */
5211