1  /* SPDX-License-Identifier: GPL-2.0-or-later */
2  /* SCTP kernel implementation
3   * (C) Copyright IBM Corp. 2001, 2004
4   * Copyright (c) 1999-2000 Cisco, Inc.
5   * Copyright (c) 1999-2001 Motorola, Inc.
6   * Copyright (c) 2001-2003 Intel Corp.
7   *
8   * This file is part of the SCTP kernel implementation
9   *
10   * The base lksctp header.
11   *
12   * Please send any bug reports or fixes you make to the
13   * email address(es):
14   *    lksctp developers <linux-sctp@vger.kernel.org>
15   *
16   * Written or modified by:
17   *    La Monte H.P. Yarroll <piggy@acm.org>
18   *    Xingang Guo           <xingang.guo@intel.com>
19   *    Jon Grimm             <jgrimm@us.ibm.com>
20   *    Daisy Chang           <daisyc@us.ibm.com>
21   *    Sridhar Samudrala     <sri@us.ibm.com>
22   *    Ardelle Fan           <ardelle.fan@intel.com>
23   *    Ryan Layer            <rmlayer@us.ibm.com>
24   *    Kevin Gao             <kevin.gao@intel.com>
25   */
26  
27  #ifndef __net_sctp_h__
28  #define __net_sctp_h__
29  
30  /* Header Strategy.
31   *    Start getting some control over the header file dependencies:
32   *       includes
33   *       constants
34   *       structs
35   *       prototypes
36   *       macros, externs, and inlines
37   *
38   *   Move test_frame specific items out of the kernel headers
39   *   and into the test frame headers.   This is not perfect in any sense
40   *   and will continue to evolve.
41   */
42  
43  #include <linux/types.h>
44  #include <linux/slab.h>
45  #include <linux/in.h>
46  #include <linux/tty.h>
47  #include <linux/proc_fs.h>
48  #include <linux/spinlock.h>
49  #include <linux/jiffies.h>
50  #include <linux/idr.h>
51  
52  #if IS_ENABLED(CONFIG_IPV6)
53  #include <net/ipv6.h>
54  #include <net/ip6_route.h>
55  #endif
56  
57  #include <linux/uaccess.h>
58  #include <asm/page.h>
59  #include <net/sock.h>
60  #include <net/snmp.h>
61  #include <net/sctp/structs.h>
62  #include <net/sctp/constants.h>
63  
64  #ifdef CONFIG_IP_SCTP_MODULE
65  #define SCTP_PROTOSW_FLAG 0
66  #else /* static! */
67  #define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
68  #endif
69  
70  /*
71   * Function declarations.
72   */
73  
74  /*
75   * sctp/protocol.c
76   */
77  int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *addr,
78  			      enum sctp_scope, gfp_t gfp, int flags);
79  struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
80  int sctp_register_pf(struct sctp_pf *, sa_family_t);
81  void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
82  int sctp_udp_sock_start(struct net *net);
83  void sctp_udp_sock_stop(struct net *net);
84  
85  /*
86   * sctp/socket.c
87   */
88  int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr,
89  		      int addr_len, int flags);
90  int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
91  int sctp_inet_listen(struct socket *sock, int backlog);
92  void sctp_write_space(struct sock *sk);
93  void sctp_data_ready(struct sock *sk);
94  __poll_t sctp_poll(struct file *file, struct socket *sock,
95  		poll_table *wait);
96  void sctp_sock_rfree(struct sk_buff *skb);
97  void sctp_copy_sock(struct sock *newsk, struct sock *sk,
98  		    struct sctp_association *asoc);
99  extern struct percpu_counter sctp_sockets_allocated;
100  int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
101  struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int *);
102  
103  typedef int (*sctp_callback_t)(struct sctp_endpoint *, struct sctp_transport *, void *);
104  void sctp_transport_walk_start(struct rhashtable_iter *iter);
105  void sctp_transport_walk_stop(struct rhashtable_iter *iter);
106  struct sctp_transport *sctp_transport_get_next(struct net *net,
107  			struct rhashtable_iter *iter);
108  struct sctp_transport *sctp_transport_get_idx(struct net *net,
109  			struct rhashtable_iter *iter, int pos);
110  int sctp_transport_lookup_process(sctp_callback_t cb, struct net *net,
111  				  const union sctp_addr *laddr,
112  				  const union sctp_addr *paddr, void *p, int dif);
113  int sctp_transport_traverse_process(sctp_callback_t cb, sctp_callback_t cb_done,
114  				    struct net *net, int *pos, void *p);
115  int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p);
116  int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc,
117  		       struct sctp_info *info);
118  
119  /*
120   * sctp/primitive.c
121   */
122  int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
123  int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
124  int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
125  int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
126  int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
127  int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
128  int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
129  			  void *arg);
130  
131  /*
132   * sctp/input.c
133   */
134  int sctp_rcv(struct sk_buff *skb);
135  int sctp_v4_err(struct sk_buff *skb, u32 info);
136  int sctp_hash_endpoint(struct sctp_endpoint *ep);
137  void sctp_unhash_endpoint(struct sctp_endpoint *);
138  struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
139  			     struct sctphdr *, struct sctp_association **,
140  			     struct sctp_transport **);
141  void sctp_err_finish(struct sock *, struct sctp_transport *);
142  int sctp_udp_v4_err(struct sock *sk, struct sk_buff *skb);
143  int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb);
144  void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
145  			   struct sctp_transport *t, __u32 pmtu);
146  void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
147  			struct sk_buff *);
148  void sctp_icmp_proto_unreachable(struct sock *sk,
149  				 struct sctp_association *asoc,
150  				 struct sctp_transport *t);
151  int sctp_transport_hashtable_init(void);
152  void sctp_transport_hashtable_destroy(void);
153  int sctp_hash_transport(struct sctp_transport *t);
154  void sctp_unhash_transport(struct sctp_transport *t);
155  struct sctp_transport *sctp_addrs_lookup_transport(
156  				struct net *net,
157  				const union sctp_addr *laddr,
158  				const union sctp_addr *paddr,
159  				int dif, int sdif);
160  struct sctp_transport *sctp_epaddr_lookup_transport(
161  				const struct sctp_endpoint *ep,
162  				const union sctp_addr *paddr);
163  bool sctp_sk_bound_dev_eq(struct net *net, int bound_dev_if, int dif, int sdif);
164  
165  /*
166   * sctp/proc.c
167   */
168  int __net_init sctp_proc_init(struct net *net);
169  
170  /*
171   * sctp/offload.c
172   */
173  int sctp_offload_init(void);
174  
175  /*
176   * sctp/stream_sched.c
177   */
178  void sctp_sched_ops_init(void);
179  
180  /*
181   * sctp/stream.c
182   */
183  int sctp_send_reset_streams(struct sctp_association *asoc,
184  			    struct sctp_reset_streams *params);
185  int sctp_send_reset_assoc(struct sctp_association *asoc);
186  int sctp_send_add_streams(struct sctp_association *asoc,
187  			  struct sctp_add_streams *params);
188  
189  /*
190   * Module global variables
191   */
192  
193   /*
194    * sctp/protocol.c
195    */
196  extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
197  extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
198  extern long sysctl_sctp_mem[3];
199  extern int sysctl_sctp_rmem[3];
200  extern int sysctl_sctp_wmem[3];
201  
202  /*
203   *  Section:  Macros, externs, and inlines
204   */
205  
206  /* SCTP SNMP MIB stats handlers */
207  #define SCTP_INC_STATS(net, field)	SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
208  #define __SCTP_INC_STATS(net, field)	__SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
209  #define SCTP_DEC_STATS(net, field)	SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
210  
211  /* sctp mib definitions */
212  enum {
213  	SCTP_MIB_NUM = 0,
214  	SCTP_MIB_CURRESTAB,			/* CurrEstab */
215  	SCTP_MIB_ACTIVEESTABS,			/* ActiveEstabs */
216  	SCTP_MIB_PASSIVEESTABS,			/* PassiveEstabs */
217  	SCTP_MIB_ABORTEDS,			/* Aborteds */
218  	SCTP_MIB_SHUTDOWNS,			/* Shutdowns */
219  	SCTP_MIB_OUTOFBLUES,			/* OutOfBlues */
220  	SCTP_MIB_CHECKSUMERRORS,		/* ChecksumErrors */
221  	SCTP_MIB_OUTCTRLCHUNKS,			/* OutCtrlChunks */
222  	SCTP_MIB_OUTORDERCHUNKS,		/* OutOrderChunks */
223  	SCTP_MIB_OUTUNORDERCHUNKS,		/* OutUnorderChunks */
224  	SCTP_MIB_INCTRLCHUNKS,			/* InCtrlChunks */
225  	SCTP_MIB_INORDERCHUNKS,			/* InOrderChunks */
226  	SCTP_MIB_INUNORDERCHUNKS,		/* InUnorderChunks */
227  	SCTP_MIB_FRAGUSRMSGS,			/* FragUsrMsgs */
228  	SCTP_MIB_REASMUSRMSGS,			/* ReasmUsrMsgs */
229  	SCTP_MIB_OUTSCTPPACKS,			/* OutSCTPPacks */
230  	SCTP_MIB_INSCTPPACKS,			/* InSCTPPacks */
231  	SCTP_MIB_T1_INIT_EXPIREDS,
232  	SCTP_MIB_T1_COOKIE_EXPIREDS,
233  	SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
234  	SCTP_MIB_T3_RTX_EXPIREDS,
235  	SCTP_MIB_T4_RTO_EXPIREDS,
236  	SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
237  	SCTP_MIB_DELAY_SACK_EXPIREDS,
238  	SCTP_MIB_AUTOCLOSE_EXPIREDS,
239  	SCTP_MIB_T1_RETRANSMITS,
240  	SCTP_MIB_T3_RETRANSMITS,
241  	SCTP_MIB_PMTUD_RETRANSMITS,
242  	SCTP_MIB_FAST_RETRANSMITS,
243  	SCTP_MIB_IN_PKT_SOFTIRQ,
244  	SCTP_MIB_IN_PKT_BACKLOG,
245  	SCTP_MIB_IN_PKT_DISCARDS,
246  	SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
247  	__SCTP_MIB_MAX
248  };
249  
250  #define SCTP_MIB_MAX    __SCTP_MIB_MAX
251  struct sctp_mib {
252          unsigned long   mibs[SCTP_MIB_MAX];
253  };
254  
255  /* helper function to track stats about max rto and related transport */
sctp_max_rto(struct sctp_association * asoc,struct sctp_transport * trans)256  static inline void sctp_max_rto(struct sctp_association *asoc,
257  				struct sctp_transport *trans)
258  {
259  	if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
260  		asoc->stats.max_obs_rto = trans->rto;
261  		memset(&asoc->stats.obs_rto_ipaddr, 0,
262  			sizeof(struct sockaddr_storage));
263  		memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
264  			trans->af_specific->sockaddr_len);
265  	}
266  }
267  
268  /*
269   * Macros for keeping a global reference of object allocations.
270   */
271  #ifdef CONFIG_SCTP_DBG_OBJCNT
272  
273  extern atomic_t sctp_dbg_objcnt_sock;
274  extern atomic_t sctp_dbg_objcnt_ep;
275  extern atomic_t sctp_dbg_objcnt_assoc;
276  extern atomic_t sctp_dbg_objcnt_transport;
277  extern atomic_t sctp_dbg_objcnt_chunk;
278  extern atomic_t sctp_dbg_objcnt_bind_addr;
279  extern atomic_t sctp_dbg_objcnt_bind_bucket;
280  extern atomic_t sctp_dbg_objcnt_addr;
281  extern atomic_t sctp_dbg_objcnt_datamsg;
282  extern atomic_t sctp_dbg_objcnt_keys;
283  
284  /* Macros to atomically increment/decrement objcnt counters.  */
285  #define SCTP_DBG_OBJCNT_INC(name) \
286  atomic_inc(&sctp_dbg_objcnt_## name)
287  #define SCTP_DBG_OBJCNT_DEC(name) \
288  atomic_dec(&sctp_dbg_objcnt_## name)
289  #define SCTP_DBG_OBJCNT(name) \
290  atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
291  
292  /* Macro to help create new entries in the global array of
293   * objcnt counters.
294   */
295  #define SCTP_DBG_OBJCNT_ENTRY(name) \
296  {.label= #name, .counter= &sctp_dbg_objcnt_## name}
297  
298  void sctp_dbg_objcnt_init(struct net *);
299  
300  #else
301  
302  #define SCTP_DBG_OBJCNT_INC(name)
303  #define SCTP_DBG_OBJCNT_DEC(name)
304  
sctp_dbg_objcnt_init(struct net * net)305  static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
306  
307  #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
308  
309  #if defined CONFIG_SYSCTL
310  void sctp_sysctl_register(void);
311  void sctp_sysctl_unregister(void);
312  int sctp_sysctl_net_register(struct net *net);
313  void sctp_sysctl_net_unregister(struct net *net);
314  #else
sctp_sysctl_register(void)315  static inline void sctp_sysctl_register(void) { return; }
sctp_sysctl_unregister(void)316  static inline void sctp_sysctl_unregister(void) { return; }
sctp_sysctl_net_register(struct net * net)317  static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
sctp_sysctl_net_unregister(struct net * net)318  static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
319  #endif
320  
321  /* Size of Supported Address Parameter for 'x' address types. */
322  #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
323  
324  #if IS_ENABLED(CONFIG_IPV6)
325  
326  void sctp_v6_pf_init(void);
327  void sctp_v6_pf_exit(void);
328  int sctp_v6_protosw_init(void);
329  void sctp_v6_protosw_exit(void);
330  int sctp_v6_add_protocol(void);
331  void sctp_v6_del_protocol(void);
332  
333  #else /* #ifdef defined(CONFIG_IPV6) */
334  
sctp_v6_pf_init(void)335  static inline void sctp_v6_pf_init(void) { return; }
sctp_v6_pf_exit(void)336  static inline void sctp_v6_pf_exit(void) { return; }
sctp_v6_protosw_init(void)337  static inline int sctp_v6_protosw_init(void) { return 0; }
sctp_v6_protosw_exit(void)338  static inline void sctp_v6_protosw_exit(void) { return; }
sctp_v6_add_protocol(void)339  static inline int sctp_v6_add_protocol(void) { return 0; }
sctp_v6_del_protocol(void)340  static inline void sctp_v6_del_protocol(void) { return; }
341  
342  #endif /* #if defined(CONFIG_IPV6) */
343  
344  
345  /* Map an association to an assoc_id. */
sctp_assoc2id(const struct sctp_association * asoc)346  static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
347  {
348  	return asoc ? asoc->assoc_id : 0;
349  }
350  
351  static inline enum sctp_sstat_state
sctp_assoc_to_state(const struct sctp_association * asoc)352  sctp_assoc_to_state(const struct sctp_association *asoc)
353  {
354  	/* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
355  	 * got rid of it in kernel space. Therefore SCTP_CLOSED et al
356  	 * start at =1 in user space, but actually as =0 in kernel space.
357  	 * Now that we can not break user space and SCTP_EMPTY is exposed
358  	 * there, we need to fix it up with an ugly offset not to break
359  	 * applications. :(
360  	 */
361  	return asoc->state + 1;
362  }
363  
364  /* Look up the association by its id.  */
365  struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
366  
367  int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
368  
369  /* A macro to walk a list of skbs.  */
370  #define sctp_skb_for_each(pos, head, tmp) \
371  	skb_queue_walk_safe(head, pos, tmp)
372  
373  /**
374   *	sctp_list_dequeue - remove from the head of the queue
375   *	@list: list to dequeue from
376   *
377   *	Remove the head of the list. The head item is
378   *	returned or %NULL if the list is empty.
379   */
380  
sctp_list_dequeue(struct list_head * list)381  static inline struct list_head *sctp_list_dequeue(struct list_head *list)
382  {
383  	struct list_head *result = NULL;
384  
385  	if (!list_empty(list)) {
386  		result = list->next;
387  		list_del_init(result);
388  	}
389  	return result;
390  }
391  
392  /* SCTP version of skb_set_owner_r.  We need this one because
393   * of the way we have to do receive buffer accounting on bundled
394   * chunks.
395   */
sctp_skb_set_owner_r(struct sk_buff * skb,struct sock * sk)396  static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
397  {
398  	struct sctp_ulpevent *event = sctp_skb2event(skb);
399  
400  	skb_orphan(skb);
401  	skb->sk = sk;
402  	skb->destructor = sctp_sock_rfree;
403  	atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
404  	/*
405  	 * This mimics the behavior of skb_set_owner_r
406  	 */
407  	sk_mem_charge(sk, event->rmem_len);
408  }
409  
410  /* Tests if the list has one and only one entry. */
sctp_list_single_entry(struct list_head * head)411  static inline int sctp_list_single_entry(struct list_head *head)
412  {
413  	return list_is_singular(head);
414  }
415  
sctp_chunk_pending(const struct sctp_chunk * chunk)416  static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
417  {
418  	return !list_empty(&chunk->list);
419  }
420  
421  /* Walk through a list of TLV parameters.  Don't trust the
422   * individual parameter lengths and instead depend on
423   * the chunk length to indicate when to stop.  Make sure
424   * there is room for a param header too.
425   */
426  #define sctp_walk_params(pos, chunk)\
427  _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length))
428  
429  #define _sctp_walk_params(pos, chunk, end)\
430  for (pos.v = (u8 *)(chunk + 1);\
431       (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\
432        (void *)chunk + end) &&\
433       pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
434       ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\
435       pos.v += SCTP_PAD4(ntohs(pos.p->length)))
436  
437  #define sctp_walk_errors(err, chunk_hdr)\
438  _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
439  
440  #define _sctp_walk_errors(err, chunk_hdr, end)\
441  for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \
442  	    sizeof(struct sctp_chunkhdr));\
443       ((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\
444        (void *)chunk_hdr + end) &&\
445       (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
446       ntohs(err->length) >= sizeof(struct sctp_errhdr); \
447       err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length))))
448  
449  #define sctp_walk_fwdtsn(pos, chunk)\
450  _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
451  
452  #define _sctp_walk_fwdtsn(pos, chunk, end)\
453  for (pos = (void *)(chunk->subh.fwdtsn_hdr + 1);\
454       (void *)pos <= (void *)(chunk->subh.fwdtsn_hdr + 1) + end - sizeof(struct sctp_fwdtsn_skip);\
455       pos++)
456  
457  /* External references. */
458  
459  extern struct proto sctp_prot;
460  extern struct proto sctpv6_prot;
461  void sctp_put_port(struct sock *sk);
462  
463  extern struct idr sctp_assocs_id;
464  extern spinlock_t sctp_assocs_id_lock;
465  
466  /* Static inline functions. */
467  
468  /* Convert from an IP version number to an Address Family symbol.  */
ipver2af(__u8 ipver)469  static inline int ipver2af(__u8 ipver)
470  {
471  	switch (ipver) {
472  	case 4:
473  	        return  AF_INET;
474  	case 6:
475  		return AF_INET6;
476  	default:
477  		return 0;
478  	}
479  }
480  
481  /* Convert from an address parameter type to an address family.  */
param_type2af(__be16 type)482  static inline int param_type2af(__be16 type)
483  {
484  	switch (type) {
485  	case SCTP_PARAM_IPV4_ADDRESS:
486  	        return  AF_INET;
487  	case SCTP_PARAM_IPV6_ADDRESS:
488  		return AF_INET6;
489  	default:
490  		return 0;
491  	}
492  }
493  
494  /* Warning: The following hash functions assume a power of two 'size'. */
495  /* This is the hash function for the SCTP port hash table. */
sctp_phashfn(struct net * net,__u16 lport)496  static inline int sctp_phashfn(struct net *net, __u16 lport)
497  {
498  	return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
499  }
500  
501  /* This is the hash function for the endpoint hash table. */
sctp_ep_hashfn(struct net * net,__u16 lport)502  static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
503  {
504  	return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
505  }
506  
507  #define sctp_for_each_hentry(ep, head) \
508  	hlist_for_each_entry(ep, head, node)
509  
510  /* Is a socket of this style? */
511  #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
__sctp_style(const struct sock * sk,enum sctp_socket_type style)512  static inline int __sctp_style(const struct sock *sk,
513  			       enum sctp_socket_type style)
514  {
515  	return sctp_sk(sk)->type == style;
516  }
517  
518  /* Is the association in this state? */
519  #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
__sctp_state(const struct sctp_association * asoc,enum sctp_state state)520  static inline int __sctp_state(const struct sctp_association *asoc,
521  			       enum sctp_state state)
522  {
523  	return asoc->state == state;
524  }
525  
526  /* Is the socket in this state? */
527  #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
__sctp_sstate(const struct sock * sk,enum sctp_sock_state state)528  static inline int __sctp_sstate(const struct sock *sk,
529  				enum sctp_sock_state state)
530  {
531  	return sk->sk_state == state;
532  }
533  
534  /* Map v4-mapped v6 address back to v4 address */
sctp_v6_map_v4(union sctp_addr * addr)535  static inline void sctp_v6_map_v4(union sctp_addr *addr)
536  {
537  	addr->v4.sin_family = AF_INET;
538  	addr->v4.sin_port = addr->v6.sin6_port;
539  	addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
540  }
541  
542  /* Map v4 address to v4-mapped v6 address */
sctp_v4_map_v6(union sctp_addr * addr)543  static inline void sctp_v4_map_v6(union sctp_addr *addr)
544  {
545  	__be16 port;
546  
547  	port = addr->v4.sin_port;
548  	addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
549  	addr->v6.sin6_port = port;
550  	addr->v6.sin6_family = AF_INET6;
551  	addr->v6.sin6_flowinfo = 0;
552  	addr->v6.sin6_scope_id = 0;
553  	addr->v6.sin6_addr.s6_addr32[0] = 0;
554  	addr->v6.sin6_addr.s6_addr32[1] = 0;
555  	addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
556  }
557  
558  /* The cookie is always 0 since this is how it's used in the
559   * pmtu code.
560   */
sctp_transport_dst_check(struct sctp_transport * t)561  static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
562  {
563  	if (t->dst && !dst_check(t->dst, t->dst_cookie))
564  		sctp_transport_dst_release(t);
565  
566  	return t->dst;
567  }
568  
569  /* Calculate max payload size given a MTU, or the total overhead if
570   * given MTU is zero
571   */
__sctp_mtu_payload(const struct sctp_sock * sp,const struct sctp_transport * t,__u32 mtu,__u32 extra)572  static inline __u32 __sctp_mtu_payload(const struct sctp_sock *sp,
573  				       const struct sctp_transport *t,
574  				       __u32 mtu, __u32 extra)
575  {
576  	__u32 overhead = sizeof(struct sctphdr) + extra;
577  
578  	if (sp) {
579  		overhead += sp->pf->af->net_header_len;
580  		if (sp->udp_port && (!t || t->encap_port))
581  			overhead += sizeof(struct udphdr);
582  	} else {
583  		overhead += sizeof(struct ipv6hdr);
584  	}
585  
586  	if (WARN_ON_ONCE(mtu && mtu <= overhead))
587  		mtu = overhead;
588  
589  	return mtu ? mtu - overhead : overhead;
590  }
591  
sctp_mtu_payload(const struct sctp_sock * sp,__u32 mtu,__u32 extra)592  static inline __u32 sctp_mtu_payload(const struct sctp_sock *sp,
593  				     __u32 mtu, __u32 extra)
594  {
595  	return __sctp_mtu_payload(sp, NULL, mtu, extra);
596  }
597  
sctp_dst_mtu(const struct dst_entry * dst)598  static inline __u32 sctp_dst_mtu(const struct dst_entry *dst)
599  {
600  	return SCTP_TRUNC4(max_t(__u32, dst_mtu(dst),
601  				 SCTP_DEFAULT_MINSEGMENT));
602  }
603  
sctp_transport_pmtu_check(struct sctp_transport * t)604  static inline bool sctp_transport_pmtu_check(struct sctp_transport *t)
605  {
606  	__u32 pmtu = sctp_dst_mtu(t->dst);
607  
608  	if (t->pathmtu == pmtu)
609  		return true;
610  
611  	t->pathmtu = pmtu;
612  
613  	return false;
614  }
615  
sctp_min_frag_point(struct sctp_sock * sp,__u16 datasize)616  static inline __u32 sctp_min_frag_point(struct sctp_sock *sp, __u16 datasize)
617  {
618  	return sctp_mtu_payload(sp, SCTP_DEFAULT_MINSEGMENT, datasize);
619  }
620  
sctp_transport_pl_hlen(struct sctp_transport * t)621  static inline int sctp_transport_pl_hlen(struct sctp_transport *t)
622  {
623  	return __sctp_mtu_payload(sctp_sk(t->asoc->base.sk), t, 0, 0) -
624  	       sizeof(struct sctphdr);
625  }
626  
sctp_transport_pl_reset(struct sctp_transport * t)627  static inline void sctp_transport_pl_reset(struct sctp_transport *t)
628  {
629  	if (t->probe_interval && (t->param_flags & SPP_PMTUD_ENABLE) &&
630  	    (t->state == SCTP_ACTIVE || t->state == SCTP_UNKNOWN)) {
631  		if (t->pl.state == SCTP_PL_DISABLED) {
632  			t->pl.state = SCTP_PL_BASE;
633  			t->pl.pmtu = SCTP_BASE_PLPMTU;
634  			t->pl.probe_size = SCTP_BASE_PLPMTU;
635  			sctp_transport_reset_probe_timer(t);
636  		}
637  	} else {
638  		if (t->pl.state != SCTP_PL_DISABLED) {
639  			if (del_timer(&t->probe_timer))
640  				sctp_transport_put(t);
641  			t->pl.state = SCTP_PL_DISABLED;
642  		}
643  	}
644  }
645  
sctp_transport_pl_update(struct sctp_transport * t)646  static inline void sctp_transport_pl_update(struct sctp_transport *t)
647  {
648  	if (t->pl.state == SCTP_PL_DISABLED)
649  		return;
650  
651  	t->pl.state = SCTP_PL_BASE;
652  	t->pl.pmtu = SCTP_BASE_PLPMTU;
653  	t->pl.probe_size = SCTP_BASE_PLPMTU;
654  	sctp_transport_reset_probe_timer(t);
655  }
656  
sctp_transport_pl_enabled(struct sctp_transport * t)657  static inline bool sctp_transport_pl_enabled(struct sctp_transport *t)
658  {
659  	return t->pl.state != SCTP_PL_DISABLED;
660  }
661  
sctp_newsk_ready(const struct sock * sk)662  static inline bool sctp_newsk_ready(const struct sock *sk)
663  {
664  	return sock_flag(sk, SOCK_DEAD) || sk->sk_socket;
665  }
666  
sctp_sock_set_nodelay(struct sock * sk)667  static inline void sctp_sock_set_nodelay(struct sock *sk)
668  {
669  	lock_sock(sk);
670  	sctp_sk(sk)->nodelay = true;
671  	release_sock(sk);
672  }
673  
674  #endif /* __net_sctp_h__ */
675