1  /* SPDX-License-Identifier: GPL-2.0-or-later */
2  /*
3   * INET		An implementation of the TCP/IP protocol suite for the LINUX
4   *		operating system.  INET is implemented using the  BSD Socket
5   *		interface as the means of communication with the user level.
6   *
7   *		Definitions for inet_sock
8   *
9   * Authors:	Many, reorganised here by
10   * 		Arnaldo Carvalho de Melo <acme@mandriva.com>
11   */
12  #ifndef _INET_SOCK_H
13  #define _INET_SOCK_H
14  
15  #include <linux/bitops.h>
16  #include <linux/string.h>
17  #include <linux/types.h>
18  #include <linux/jhash.h>
19  #include <linux/netdevice.h>
20  
21  #include <net/flow.h>
22  #include <net/sock.h>
23  #include <net/request_sock.h>
24  #include <net/netns/hash.h>
25  #include <net/tcp_states.h>
26  #include <net/l3mdev.h>
27  
28  /** struct ip_options - IP Options
29   *
30   * @faddr - Saved first hop address
31   * @nexthop - Saved nexthop address in LSRR and SSRR
32   * @is_strictroute - Strict source route
33   * @srr_is_hit - Packet destination addr was our one
34   * @is_changed - IP checksum more not valid
35   * @rr_needaddr - Need to record addr of outgoing dev
36   * @ts_needtime - Need to record timestamp
37   * @ts_needaddr - Need to record addr of outgoing dev
38   */
39  struct ip_options {
40  	__be32		faddr;
41  	__be32		nexthop;
42  	unsigned char	optlen;
43  	unsigned char	srr;
44  	unsigned char	rr;
45  	unsigned char	ts;
46  	unsigned char	is_strictroute:1,
47  			srr_is_hit:1,
48  			is_changed:1,
49  			rr_needaddr:1,
50  			ts_needtime:1,
51  			ts_needaddr:1;
52  	unsigned char	router_alert;
53  	unsigned char	cipso;
54  	unsigned char	__pad2;
55  	unsigned char	__data[];
56  };
57  
58  struct ip_options_rcu {
59  	struct rcu_head rcu;
60  	struct ip_options opt;
61  };
62  
63  struct ip_options_data {
64  	struct ip_options_rcu	opt;
65  	char			data[40];
66  };
67  
68  struct inet_request_sock {
69  	struct request_sock	req;
70  #define ir_loc_addr		req.__req_common.skc_rcv_saddr
71  #define ir_rmt_addr		req.__req_common.skc_daddr
72  #define ir_num			req.__req_common.skc_num
73  #define ir_rmt_port		req.__req_common.skc_dport
74  #define ir_v6_rmt_addr		req.__req_common.skc_v6_daddr
75  #define ir_v6_loc_addr		req.__req_common.skc_v6_rcv_saddr
76  #define ir_iif			req.__req_common.skc_bound_dev_if
77  #define ir_cookie		req.__req_common.skc_cookie
78  #define ireq_net		req.__req_common.skc_net
79  #define ireq_state		req.__req_common.skc_state
80  #define ireq_family		req.__req_common.skc_family
81  
82  	u16			snd_wscale : 4,
83  				rcv_wscale : 4,
84  				tstamp_ok  : 1,
85  				sack_ok	   : 1,
86  				wscale_ok  : 1,
87  				ecn_ok	   : 1,
88  				acked	   : 1,
89  				no_srccheck: 1,
90  				smc_ok	   : 1;
91  	u32                     ir_mark;
92  	union {
93  		struct ip_options_rcu __rcu	*ireq_opt;
94  #if IS_ENABLED(CONFIG_IPV6)
95  		struct {
96  			struct ipv6_txoptions	*ipv6_opt;
97  			struct sk_buff		*pktopts;
98  		};
99  #endif
100  	};
101  };
102  
inet_rsk(const struct request_sock * sk)103  static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
104  {
105  	return (struct inet_request_sock *)sk;
106  }
107  
inet_request_mark(const struct sock * sk,struct sk_buff * skb)108  static inline u32 inet_request_mark(const struct sock *sk, struct sk_buff *skb)
109  {
110  	u32 mark = READ_ONCE(sk->sk_mark);
111  
112  	if (!mark && READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept))
113  		return skb->mark;
114  
115  	return mark;
116  }
117  
inet_request_bound_dev_if(const struct sock * sk,struct sk_buff * skb)118  static inline int inet_request_bound_dev_if(const struct sock *sk,
119  					    struct sk_buff *skb)
120  {
121  	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
122  #ifdef CONFIG_NET_L3_MASTER_DEV
123  	struct net *net = sock_net(sk);
124  
125  	if (!bound_dev_if && READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
126  		return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
127  #endif
128  
129  	return bound_dev_if;
130  }
131  
inet_sk_bound_l3mdev(const struct sock * sk)132  static inline int inet_sk_bound_l3mdev(const struct sock *sk)
133  {
134  #ifdef CONFIG_NET_L3_MASTER_DEV
135  	struct net *net = sock_net(sk);
136  
137  	if (!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
138  		return l3mdev_master_ifindex_by_index(net,
139  						      sk->sk_bound_dev_if);
140  #endif
141  
142  	return 0;
143  }
144  
inet_bound_dev_eq(bool l3mdev_accept,int bound_dev_if,int dif,int sdif)145  static inline bool inet_bound_dev_eq(bool l3mdev_accept, int bound_dev_if,
146  				     int dif, int sdif)
147  {
148  	if (!bound_dev_if)
149  		return !sdif || l3mdev_accept;
150  	return bound_dev_if == dif || bound_dev_if == sdif;
151  }
152  
inet_sk_bound_dev_eq(const struct net * net,int bound_dev_if,int dif,int sdif)153  static inline bool inet_sk_bound_dev_eq(const struct net *net,
154  					int bound_dev_if,
155  					int dif, int sdif)
156  {
157  #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
158  	return inet_bound_dev_eq(!!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept),
159  				 bound_dev_if, dif, sdif);
160  #else
161  	return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);
162  #endif
163  }
164  
165  struct inet_cork {
166  	unsigned int		flags;
167  	__be32			addr;
168  	struct ip_options	*opt;
169  	unsigned int		fragsize;
170  	int			length; /* Total length of all frames */
171  	struct dst_entry	*dst;
172  	u8			tx_flags;
173  	__u8			ttl;
174  	__s16			tos;
175  	char			priority;
176  	__u16			gso_size;
177  	u64			transmit_time;
178  	u32			mark;
179  };
180  
181  struct inet_cork_full {
182  	struct inet_cork	base;
183  	struct flowi		fl;
184  };
185  
186  struct ip_mc_socklist;
187  struct ipv6_pinfo;
188  struct rtable;
189  
190  /** struct inet_sock - representation of INET sockets
191   *
192   * @sk - ancestor class
193   * @pinet6 - pointer to IPv6 control block
194   * @inet_daddr - Foreign IPv4 addr
195   * @inet_rcv_saddr - Bound local IPv4 addr
196   * @inet_dport - Destination port
197   * @inet_num - Local port
198   * @inet_flags - various atomic flags
199   * @inet_saddr - Sending source
200   * @uc_ttl - Unicast TTL
201   * @inet_sport - Source port
202   * @inet_id - ID counter for DF pkts
203   * @tos - TOS
204   * @mc_ttl - Multicasting TTL
205   * @uc_index - Unicast outgoing device index
206   * @mc_index - Multicast device index
207   * @mc_list - Group array
208   * @cork - info to build ip hdr on each ip frag while socket is corked
209   */
210  struct inet_sock {
211  	/* sk and pinet6 has to be the first two members of inet_sock */
212  	struct sock		sk;
213  #if IS_ENABLED(CONFIG_IPV6)
214  	struct ipv6_pinfo	*pinet6;
215  #endif
216  	/* Socket demultiplex comparisons on incoming packets. */
217  #define inet_daddr		sk.__sk_common.skc_daddr
218  #define inet_rcv_saddr		sk.__sk_common.skc_rcv_saddr
219  #define inet_dport		sk.__sk_common.skc_dport
220  #define inet_num		sk.__sk_common.skc_num
221  
222  	unsigned long		inet_flags;
223  	__be32			inet_saddr;
224  	__s16			uc_ttl;
225  	__be16			inet_sport;
226  	struct ip_options_rcu __rcu	*inet_opt;
227  	atomic_t		inet_id;
228  
229  	__u8			tos;
230  	__u8			min_ttl;
231  	__u8			mc_ttl;
232  	__u8			pmtudisc;
233  	__u8			rcv_tos;
234  	__u8			convert_csum;
235  	int			uc_index;
236  	int			mc_index;
237  	__be32			mc_addr;
238  	u32			local_port_range;	/* high << 16 | low */
239  
240  	struct ip_mc_socklist __rcu	*mc_list;
241  	struct inet_cork_full	cork;
242  };
243  
244  #define IPCORK_OPT	1	/* ip-options has been held in ipcork.opt */
245  
246  enum {
247  	INET_FLAGS_PKTINFO	= 0,
248  	INET_FLAGS_TTL		= 1,
249  	INET_FLAGS_TOS		= 2,
250  	INET_FLAGS_RECVOPTS	= 3,
251  	INET_FLAGS_RETOPTS	= 4,
252  	INET_FLAGS_PASSSEC	= 5,
253  	INET_FLAGS_ORIGDSTADDR	= 6,
254  	INET_FLAGS_CHECKSUM	= 7,
255  	INET_FLAGS_RECVFRAGSIZE	= 8,
256  
257  	INET_FLAGS_RECVERR	= 9,
258  	INET_FLAGS_RECVERR_RFC4884 = 10,
259  	INET_FLAGS_FREEBIND	= 11,
260  	INET_FLAGS_HDRINCL	= 12,
261  	INET_FLAGS_MC_LOOP	= 13,
262  	INET_FLAGS_MC_ALL	= 14,
263  	INET_FLAGS_TRANSPARENT	= 15,
264  	INET_FLAGS_IS_ICSK	= 16,
265  	INET_FLAGS_NODEFRAG	= 17,
266  	INET_FLAGS_BIND_ADDRESS_NO_PORT = 18,
267  	INET_FLAGS_DEFER_CONNECT = 19,
268  	INET_FLAGS_MC6_LOOP	= 20,
269  	INET_FLAGS_RECVERR6_RFC4884 = 21,
270  	INET_FLAGS_MC6_ALL	= 22,
271  	INET_FLAGS_AUTOFLOWLABEL_SET = 23,
272  	INET_FLAGS_AUTOFLOWLABEL = 24,
273  	INET_FLAGS_DONTFRAG	= 25,
274  	INET_FLAGS_RECVERR6	= 26,
275  	INET_FLAGS_REPFLOW	= 27,
276  	INET_FLAGS_RTALERT_ISOLATE = 28,
277  	INET_FLAGS_SNDFLOW	= 29,
278  	INET_FLAGS_RTALERT	= 30,
279  };
280  
281  /* cmsg flags for inet */
282  #define IP_CMSG_PKTINFO		BIT(INET_FLAGS_PKTINFO)
283  #define IP_CMSG_TTL		BIT(INET_FLAGS_TTL)
284  #define IP_CMSG_TOS		BIT(INET_FLAGS_TOS)
285  #define IP_CMSG_RECVOPTS	BIT(INET_FLAGS_RECVOPTS)
286  #define IP_CMSG_RETOPTS		BIT(INET_FLAGS_RETOPTS)
287  #define IP_CMSG_PASSSEC		BIT(INET_FLAGS_PASSSEC)
288  #define IP_CMSG_ORIGDSTADDR	BIT(INET_FLAGS_ORIGDSTADDR)
289  #define IP_CMSG_CHECKSUM	BIT(INET_FLAGS_CHECKSUM)
290  #define IP_CMSG_RECVFRAGSIZE	BIT(INET_FLAGS_RECVFRAGSIZE)
291  
292  #define IP_CMSG_ALL	(IP_CMSG_PKTINFO | IP_CMSG_TTL |		\
293  			 IP_CMSG_TOS | IP_CMSG_RECVOPTS |		\
294  			 IP_CMSG_RETOPTS | IP_CMSG_PASSSEC |		\
295  			 IP_CMSG_ORIGDSTADDR | IP_CMSG_CHECKSUM |	\
296  			 IP_CMSG_RECVFRAGSIZE)
297  
inet_cmsg_flags(const struct inet_sock * inet)298  static inline unsigned long inet_cmsg_flags(const struct inet_sock *inet)
299  {
300  	return READ_ONCE(inet->inet_flags) & IP_CMSG_ALL;
301  }
302  
303  #define inet_test_bit(nr, sk)			\
304  	test_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
305  #define inet_set_bit(nr, sk)			\
306  	set_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
307  #define inet_clear_bit(nr, sk)			\
308  	clear_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
309  #define inet_assign_bit(nr, sk, val)		\
310  	assign_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags, val)
311  
312  /**
313   * sk_to_full_sk - Access to a full socket
314   * @sk: pointer to a socket
315   *
316   * SYNACK messages might be attached to request sockets.
317   * Some places want to reach the listener in this case.
318   */
sk_to_full_sk(struct sock * sk)319  static inline struct sock *sk_to_full_sk(struct sock *sk)
320  {
321  #ifdef CONFIG_INET
322  	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
323  		sk = inet_reqsk(sk)->rsk_listener;
324  #endif
325  	return sk;
326  }
327  
328  /* sk_to_full_sk() variant with a const argument */
sk_const_to_full_sk(const struct sock * sk)329  static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
330  {
331  #ifdef CONFIG_INET
332  	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
333  		sk = ((const struct request_sock *)sk)->rsk_listener;
334  #endif
335  	return sk;
336  }
337  
skb_to_full_sk(const struct sk_buff * skb)338  static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
339  {
340  	return sk_to_full_sk(skb->sk);
341  }
342  
343  #define inet_sk(ptr) container_of_const(ptr, struct inet_sock, sk)
344  
__inet_sk_copy_descendant(struct sock * sk_to,const struct sock * sk_from,const int ancestor_size)345  static inline void __inet_sk_copy_descendant(struct sock *sk_to,
346  					     const struct sock *sk_from,
347  					     const int ancestor_size)
348  {
349  	memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
350  	       sk_from->sk_prot->obj_size - ancestor_size);
351  }
352  
353  int inet_sk_rebuild_header(struct sock *sk);
354  
355  /**
356   * inet_sk_state_load - read sk->sk_state for lockless contexts
357   * @sk: socket pointer
358   *
359   * Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
360   * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
361   */
inet_sk_state_load(const struct sock * sk)362  static inline int inet_sk_state_load(const struct sock *sk)
363  {
364  	/* state change might impact lockless readers. */
365  	return smp_load_acquire(&sk->sk_state);
366  }
367  
368  /**
369   * inet_sk_state_store - update sk->sk_state
370   * @sk: socket pointer
371   * @newstate: new state
372   *
373   * Paired with inet_sk_state_load(). Should be used in contexts where
374   * state change might impact lockless readers.
375   */
376  void inet_sk_state_store(struct sock *sk, int newstate);
377  
378  void inet_sk_set_state(struct sock *sk, int state);
379  
__inet_ehashfn(const __be32 laddr,const __u16 lport,const __be32 faddr,const __be16 fport,u32 initval)380  static inline unsigned int __inet_ehashfn(const __be32 laddr,
381  					  const __u16 lport,
382  					  const __be32 faddr,
383  					  const __be16 fport,
384  					  u32 initval)
385  {
386  	return jhash_3words((__force __u32) laddr,
387  			    (__force __u32) faddr,
388  			    ((__u32) lport) << 16 | (__force __u32)fport,
389  			    initval);
390  }
391  
392  struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
393  				      struct sock *sk_listener,
394  				      bool attach_listener);
395  
inet_sk_flowi_flags(const struct sock * sk)396  static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
397  {
398  	__u8 flags = 0;
399  
400  	if (inet_test_bit(TRANSPARENT, sk) || inet_test_bit(HDRINCL, sk))
401  		flags |= FLOWI_FLAG_ANYSRC;
402  	return flags;
403  }
404  
inet_inc_convert_csum(struct sock * sk)405  static inline void inet_inc_convert_csum(struct sock *sk)
406  {
407  	inet_sk(sk)->convert_csum++;
408  }
409  
inet_dec_convert_csum(struct sock * sk)410  static inline void inet_dec_convert_csum(struct sock *sk)
411  {
412  	if (inet_sk(sk)->convert_csum > 0)
413  		inet_sk(sk)->convert_csum--;
414  }
415  
inet_get_convert_csum(struct sock * sk)416  static inline bool inet_get_convert_csum(struct sock *sk)
417  {
418  	return !!inet_sk(sk)->convert_csum;
419  }
420  
421  
inet_can_nonlocal_bind(struct net * net,struct inet_sock * inet)422  static inline bool inet_can_nonlocal_bind(struct net *net,
423  					  struct inet_sock *inet)
424  {
425  	return READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind) ||
426  		test_bit(INET_FLAGS_FREEBIND, &inet->inet_flags) ||
427  		test_bit(INET_FLAGS_TRANSPARENT, &inet->inet_flags);
428  }
429  
inet_addr_valid_or_nonlocal(struct net * net,struct inet_sock * inet,__be32 addr,int addr_type)430  static inline bool inet_addr_valid_or_nonlocal(struct net *net,
431  					       struct inet_sock *inet,
432  					       __be32 addr,
433  					       int addr_type)
434  {
435  	return inet_can_nonlocal_bind(net, inet) ||
436  		addr == htonl(INADDR_ANY) ||
437  		addr_type == RTN_LOCAL ||
438  		addr_type == RTN_MULTICAST ||
439  		addr_type == RTN_BROADCAST;
440  }
441  
442  #endif	/* _INET_SOCK_H */
443