xref: /linux/include/net/sctp/sctp.h (revision f24e9f586b377749dff37554696cf3a105540c94)
1 /* SCTP kernel reference Implementation
2  * (C) Copyright IBM Corp. 2001, 2004
3  * Copyright (c) 1999-2000 Cisco, Inc.
4  * Copyright (c) 1999-2001 Motorola, Inc.
5  * Copyright (c) 2001-2003 Intel Corp.
6  *
7  * This file is part of the SCTP kernel reference Implementation
8  *
9  * The base lksctp header.
10  *
11  * The SCTP reference implementation is free software;
12  * you can redistribute it and/or modify it under the terms of
13  * the GNU General Public License as published by
14  * the Free Software Foundation; either version 2, or (at your option)
15  * any later version.
16  *
17  * The SCTP reference implementation is distributed in the hope that it
18  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
19  *                 ************************
20  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
21  * See the GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with GNU CC; see the file COPYING.  If not, write to
25  * the Free Software Foundation, 59 Temple Place - Suite 330,
26  * Boston, MA 02111-1307, USA.
27  *
28  * Please send any bug reports or fixes you make to the
29  * email address(es):
30  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
31  *
32  * Or submit a bug report through the following website:
33  *    http://www.sf.net/projects/lksctp
34  *
35  * Written or modified by:
36  *    La Monte H.P. Yarroll <piggy@acm.org>
37  *    Xingang Guo           <xingang.guo@intel.com>
38  *    Jon Grimm             <jgrimm@us.ibm.com>
39  *    Daisy Chang           <daisyc@us.ibm.com>
40  *    Sridhar Samudrala     <sri@us.ibm.com>
41  *    Ardelle Fan           <ardelle.fan@intel.com>
42  *    Ryan Layer            <rmlayer@us.ibm.com>
43  *    Kevin Gao             <kevin.gao@intel.com>
44  *
45  * Any bugs reported given to us we will try to fix... any fixes shared will
46  * be incorporated into the next SCTP release.
47  */
48 
49 #ifndef __net_sctp_h__
50 #define __net_sctp_h__
51 
52 /* Header Strategy.
53  *    Start getting some control over the header file depencies:
54  *       includes
55  *       constants
56  *       structs
57  *       prototypes
58  *       macros, externs, and inlines
59  *
60  *   Move test_frame specific items out of the kernel headers
61  *   and into the test frame headers.   This is not perfect in any sense
62  *   and will continue to evolve.
63  */
64 
65 
66 
67 #ifdef TEST_FRAME
68 #undef CONFIG_PROC_FS
69 #undef CONFIG_SCTP_DBG_OBJCNT
70 #undef CONFIG_SYSCTL
71 #endif /* TEST_FRAME */
72 
73 #include <linux/types.h>
74 #include <linux/slab.h>
75 #include <linux/in.h>
76 #include <linux/tty.h>
77 #include <linux/proc_fs.h>
78 #include <linux/spinlock.h>
79 #include <linux/jiffies.h>
80 #include <linux/idr.h>
81 
82 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
83 #include <net/ipv6.h>
84 #include <net/ip6_route.h>
85 #endif
86 
87 #include <asm/uaccess.h>
88 #include <asm/page.h>
89 #include <net/sock.h>
90 #include <net/snmp.h>
91 #include <net/sctp/structs.h>
92 #include <net/sctp/constants.h>
93 
94 
95 /* Set SCTP_DEBUG flag via config if not already set. */
96 #ifndef SCTP_DEBUG
97 #ifdef CONFIG_SCTP_DBG_MSG
98 #define SCTP_DEBUG	1
99 #else
100 #define SCTP_DEBUG      0
101 #endif /* CONFIG_SCTP_DBG */
102 #endif /* SCTP_DEBUG */
103 
104 #ifdef CONFIG_IP_SCTP_MODULE
105 #define SCTP_PROTOSW_FLAG 0
106 #else /* static! */
107 #define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
108 #endif
109 
110 
111 /* Certain internal static functions need to be exported when
112  * compiled into the test frame.
113  */
114 #ifndef SCTP_STATIC
115 #define SCTP_STATIC static
116 #endif
117 
118 /*
119  * Function declarations.
120  */
121 
122 /*
123  * sctp/protocol.c
124  */
125 extern struct sock *sctp_get_ctl_sock(void);
126 extern int sctp_copy_local_addr_list(struct sctp_bind_addr *,
127 				     sctp_scope_t, gfp_t gfp,
128 				     int flags);
129 extern struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
130 extern int sctp_register_pf(struct sctp_pf *, sa_family_t);
131 
132 /*
133  * sctp/socket.c
134  */
135 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
136 int sctp_inet_listen(struct socket *sock, int backlog);
137 void sctp_write_space(struct sock *sk);
138 unsigned int sctp_poll(struct file *file, struct socket *sock,
139 		poll_table *wait);
140 
141 /*
142  * sctp/primitive.c
143  */
144 int sctp_primitive_ASSOCIATE(struct sctp_association *, void *arg);
145 int sctp_primitive_SHUTDOWN(struct sctp_association *, void *arg);
146 int sctp_primitive_ABORT(struct sctp_association *, void *arg);
147 int sctp_primitive_SEND(struct sctp_association *, void *arg);
148 int sctp_primitive_REQUESTHEARTBEAT(struct sctp_association *, void *arg);
149 int sctp_primitive_ASCONF(struct sctp_association *, void *arg);
150 
151 /*
152  * sctp/crc32c.c
153  */
154 __u32 sctp_start_cksum(__u8 *ptr, __u16 count);
155 __u32 sctp_update_cksum(__u8 *ptr, __u16 count, __u32 cksum);
156 __u32 sctp_end_cksum(__u32 cksum);
157 __u32 sctp_update_copy_cksum(__u8 *, __u8 *, __u16 count, __u32 cksum);
158 
159 /*
160  * sctp/input.c
161  */
162 int sctp_rcv(struct sk_buff *skb);
163 void sctp_v4_err(struct sk_buff *skb, u32 info);
164 void sctp_hash_established(struct sctp_association *);
165 void sctp_unhash_established(struct sctp_association *);
166 void sctp_hash_endpoint(struct sctp_endpoint *);
167 void sctp_unhash_endpoint(struct sctp_endpoint *);
168 struct sock *sctp_err_lookup(int family, struct sk_buff *,
169 			     struct sctphdr *, struct sctp_association **,
170 			     struct sctp_transport **);
171 void sctp_err_finish(struct sock *, struct sctp_association *);
172 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
173 			   struct sctp_transport *t, __u32 pmtu);
174 void sctp_icmp_proto_unreachable(struct sock *sk,
175 				 struct sctp_association *asoc,
176 				 struct sctp_transport *t);
177 void sctp_backlog_migrate(struct sctp_association *assoc,
178 			  struct sock *oldsk, struct sock *newsk);
179 
180 /*
181  *  Section:  Macros, externs, and inlines
182  */
183 
184 
185 #ifdef TEST_FRAME
186 #include <test_frame.h>
187 #else
188 
189 /* spin lock wrappers. */
190 #define sctp_spin_lock_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
191 #define sctp_spin_unlock_irqrestore(lock, flags)  \
192        spin_unlock_irqrestore(lock, flags)
193 #define sctp_local_bh_disable() local_bh_disable()
194 #define sctp_local_bh_enable()  local_bh_enable()
195 #define sctp_spin_lock(lock)    spin_lock(lock)
196 #define sctp_spin_unlock(lock)  spin_unlock(lock)
197 #define sctp_write_lock(lock)   write_lock(lock)
198 #define sctp_write_unlock(lock) write_unlock(lock)
199 #define sctp_read_lock(lock)    read_lock(lock)
200 #define sctp_read_unlock(lock)  read_unlock(lock)
201 
202 /* sock lock wrappers. */
203 #define sctp_lock_sock(sk)       lock_sock(sk)
204 #define sctp_release_sock(sk)    release_sock(sk)
205 #define sctp_bh_lock_sock(sk)    bh_lock_sock(sk)
206 #define sctp_bh_unlock_sock(sk)  bh_unlock_sock(sk)
207 #define SCTP_SOCK_SLEEP_PRE(sk)  SOCK_SLEEP_PRE(sk)
208 #define SCTP_SOCK_SLEEP_POST(sk) SOCK_SLEEP_POST(sk)
209 
210 /* SCTP SNMP MIB stats handlers */
211 DECLARE_SNMP_STAT(struct sctp_mib, sctp_statistics);
212 #define SCTP_INC_STATS(field)      SNMP_INC_STATS(sctp_statistics, field)
213 #define SCTP_INC_STATS_BH(field)   SNMP_INC_STATS_BH(sctp_statistics, field)
214 #define SCTP_INC_STATS_USER(field) SNMP_INC_STATS_USER(sctp_statistics, field)
215 #define SCTP_DEC_STATS(field)      SNMP_DEC_STATS(sctp_statistics, field)
216 
217 #endif /* !TEST_FRAME */
218 
219 
220 /* Print debugging messages.  */
221 #if SCTP_DEBUG
222 extern int sctp_debug_flag;
223 #define SCTP_DEBUG_PRINTK(whatever...) \
224 	((void) (sctp_debug_flag && printk(KERN_DEBUG whatever)))
225 #define SCTP_DEBUG_PRINTK_IPADDR(lead, trail, leadparm, saddr, otherparms...) \
226 	if (sctp_debug_flag) { \
227 		if (saddr->sa.sa_family == AF_INET6) { \
228 			printk(KERN_DEBUG \
229 			       lead NIP6_FMT trail, \
230 			       leadparm, \
231 			       NIP6(saddr->v6.sin6_addr), \
232 			       otherparms); \
233 		} else { \
234 			printk(KERN_DEBUG \
235 			       lead NIPQUAD_FMT trail, \
236 			       leadparm, \
237 			       NIPQUAD(saddr->v4.sin_addr.s_addr), \
238 			       otherparms); \
239 		} \
240 	}
241 #define SCTP_ENABLE_DEBUG { sctp_debug_flag = 1; }
242 #define SCTP_DISABLE_DEBUG { sctp_debug_flag = 0; }
243 
244 #define SCTP_ASSERT(expr, str, func) \
245 	if (!(expr)) { \
246 		SCTP_DEBUG_PRINTK("Assertion Failed: %s(%s) at %s:%s:%d\n", \
247 			str, (#expr), __FILE__, __FUNCTION__, __LINE__); \
248 		func; \
249 	}
250 
251 #else	/* SCTP_DEBUG */
252 
253 #define SCTP_DEBUG_PRINTK(whatever...)
254 #define SCTP_DEBUG_PRINTK_IPADDR(whatever...)
255 #define SCTP_ENABLE_DEBUG
256 #define SCTP_DISABLE_DEBUG
257 #define SCTP_ASSERT(expr, str, func)
258 
259 #endif /* SCTP_DEBUG */
260 
261 
262 /*
263  * Macros for keeping a global reference of object allocations.
264  */
265 #ifdef CONFIG_SCTP_DBG_OBJCNT
266 
267 extern atomic_t sctp_dbg_objcnt_sock;
268 extern atomic_t sctp_dbg_objcnt_ep;
269 extern atomic_t sctp_dbg_objcnt_assoc;
270 extern atomic_t sctp_dbg_objcnt_transport;
271 extern atomic_t sctp_dbg_objcnt_chunk;
272 extern atomic_t sctp_dbg_objcnt_bind_addr;
273 extern atomic_t sctp_dbg_objcnt_bind_bucket;
274 extern atomic_t sctp_dbg_objcnt_addr;
275 extern atomic_t sctp_dbg_objcnt_ssnmap;
276 extern atomic_t sctp_dbg_objcnt_datamsg;
277 
278 /* Macros to atomically increment/decrement objcnt counters.  */
279 #define SCTP_DBG_OBJCNT_INC(name) \
280 atomic_inc(&sctp_dbg_objcnt_## name)
281 #define SCTP_DBG_OBJCNT_DEC(name) \
282 atomic_dec(&sctp_dbg_objcnt_## name)
283 #define SCTP_DBG_OBJCNT(name) \
284 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
285 
286 /* Macro to help create new entries in in the global array of
287  * objcnt counters.
288  */
289 #define SCTP_DBG_OBJCNT_ENTRY(name) \
290 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
291 
292 void sctp_dbg_objcnt_init(void);
293 void sctp_dbg_objcnt_exit(void);
294 
295 #else
296 
297 #define SCTP_DBG_OBJCNT_INC(name)
298 #define SCTP_DBG_OBJCNT_DEC(name)
299 
300 static inline void sctp_dbg_objcnt_init(void) { return; }
301 static inline void sctp_dbg_objcnt_exit(void) { return; }
302 
303 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
304 
305 #if defined CONFIG_SYSCTL
306 void sctp_sysctl_register(void);
307 void sctp_sysctl_unregister(void);
308 #else
309 static inline void sctp_sysctl_register(void) { return; }
310 static inline void sctp_sysctl_unregister(void) { return; }
311 static inline int sctp_sysctl_jiffies_ms(ctl_table *table, int __user *name, int nlen,
312 		void __user *oldval, size_t __user *oldlenp,
313 		void __user *newval, size_t newlen, void **context) {
314 	return -ENOSYS;
315 }
316 #endif
317 
318 /* Size of Supported Address Parameter for 'x' address types. */
319 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
320 
321 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
322 
323 int sctp_v6_init(void);
324 void sctp_v6_exit(void);
325 
326 #else /* #ifdef defined(CONFIG_IPV6) */
327 
328 static inline int sctp_v6_init(void) { return 0; }
329 static inline void sctp_v6_exit(void) { return; }
330 
331 #endif /* #if defined(CONFIG_IPV6) */
332 
333 
334 /* Map an association to an assoc_id. */
335 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
336 {
337 	return (asoc?asoc->assoc_id:0);
338 }
339 
340 /* Look up the association by its id.  */
341 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
342 
343 
344 /* A macro to walk a list of skbs.  */
345 #define sctp_skb_for_each(pos, head, tmp) \
346 for (pos = (head)->next;\
347      tmp = (pos)->next, pos != ((struct sk_buff *)(head));\
348      pos = tmp)
349 
350 
351 /* A helper to append an entire skb list (list) to another (head). */
352 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
353 				      struct sk_buff_head *head)
354 {
355 	unsigned long flags;
356 
357 	sctp_spin_lock_irqsave(&head->lock, flags);
358 	sctp_spin_lock(&list->lock);
359 
360 	list_splice((struct list_head *)list, (struct list_head *)head->prev);
361 
362 	head->qlen += list->qlen;
363 	list->qlen = 0;
364 
365 	sctp_spin_unlock(&list->lock);
366 	sctp_spin_unlock_irqrestore(&head->lock, flags);
367 }
368 
369 /**
370  *	sctp_list_dequeue - remove from the head of the queue
371  *	@list: list to dequeue from
372  *
373  *	Remove the head of the list. The head item is
374  *	returned or %NULL if the list is empty.
375  */
376 
377 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
378 {
379 	struct list_head *result = NULL;
380 
381 	if (list->next != list) {
382 		result = list->next;
383 		list->next = result->next;
384 		list->next->prev = list;
385 		INIT_LIST_HEAD(result);
386 	}
387 	return result;
388 }
389 
390 /* Tests if the list has one and only one entry. */
391 static inline int sctp_list_single_entry(struct list_head *head)
392 {
393 	return ((head->next != head) && (head->next == head->prev));
394 }
395 
396 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
397 static inline __s32 sctp_jitter(__u32 rto)
398 {
399 	static __u32 sctp_rand;
400 	__s32 ret;
401 
402 	/* Avoid divide by zero. */
403 	if (!rto)
404 		rto = 1;
405 
406 	sctp_rand += jiffies;
407 	sctp_rand ^= (sctp_rand << 12);
408 	sctp_rand ^= (sctp_rand >> 20);
409 
410 	/* Choose random number from 0 to rto, then move to -50% ~ +50%
411 	 * of rto.
412 	 */
413 	ret = sctp_rand % rto - (rto >> 1);
414 	return ret;
415 }
416 
417 /* Break down data chunks at this point.  */
418 static inline int sctp_frag_point(const struct sctp_sock *sp, int pmtu)
419 {
420 	int frag = pmtu;
421 
422 	frag -= sp->pf->af->net_header_len;
423 	frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
424 
425 	if (sp->user_frag)
426 		frag = min_t(int, frag, sp->user_frag);
427 
428 	frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
429 
430 	return frag;
431 }
432 
433 /* Walk through a list of TLV parameters.  Don't trust the
434  * individual parameter lengths and instead depend on
435  * the chunk length to indicate when to stop.  Make sure
436  * there is room for a param header too.
437  */
438 #define sctp_walk_params(pos, chunk, member)\
439 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
440 
441 #define _sctp_walk_params(pos, chunk, end, member)\
442 for (pos.v = chunk->member;\
443      pos.v <= (void *)chunk + end - sizeof(sctp_paramhdr_t) &&\
444      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
445      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
446      pos.v += WORD_ROUND(ntohs(pos.p->length)))
447 
448 #define sctp_walk_errors(err, chunk_hdr)\
449 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
450 
451 #define _sctp_walk_errors(err, chunk_hdr, end)\
452 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
453 	    sizeof(sctp_chunkhdr_t));\
454      (void *)err <= (void *)chunk_hdr + end - sizeof(sctp_errhdr_t) &&\
455      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
456      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
457      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
458 
459 #define sctp_walk_fwdtsn(pos, chunk)\
460 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
461 
462 #define _sctp_walk_fwdtsn(pos, chunk, end)\
463 for (pos = chunk->subh.fwdtsn_hdr->skip;\
464      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
465      pos++)
466 
467 /* Round an int up to the next multiple of 4.  */
468 #define WORD_ROUND(s) (((s)+3)&~3)
469 
470 /* Make a new instance of type.  */
471 #define t_new(type, flags)	(type *)kmalloc(sizeof(type), flags)
472 
473 /* Compare two timevals.  */
474 #define tv_lt(s, t) \
475    (s.tv_sec < t.tv_sec || (s.tv_sec == t.tv_sec && s.tv_usec < t.tv_usec))
476 
477 /* Add tv1 to tv2. */
478 #define TIMEVAL_ADD(tv1, tv2) \
479 ({ \
480         suseconds_t usecs = (tv2).tv_usec + (tv1).tv_usec; \
481         time_t secs = (tv2).tv_sec + (tv1).tv_sec; \
482 \
483         if (usecs >= 1000000) { \
484                 usecs -= 1000000; \
485                 secs++; \
486         } \
487         (tv2).tv_sec = secs; \
488         (tv2).tv_usec = usecs; \
489 })
490 
491 /* External references. */
492 
493 extern struct proto sctp_prot;
494 extern struct proto sctpv6_prot;
495 extern struct proc_dir_entry *proc_net_sctp;
496 void sctp_put_port(struct sock *sk);
497 
498 extern struct idr sctp_assocs_id;
499 extern spinlock_t sctp_assocs_id_lock;
500 
501 /* Static inline functions. */
502 
503 /* Convert from an IP version number to an Address Family symbol.  */
504 static inline int ipver2af(__u8 ipver)
505 {
506 	switch (ipver) {
507 	case 4:
508 	        return  AF_INET;
509 	case 6:
510 		return AF_INET6;
511 	default:
512 		return 0;
513 	};
514 }
515 
516 /* Convert from an address parameter type to an address family.  */
517 static inline int param_type2af(__u16 type)
518 {
519 	switch (type) {
520 	case SCTP_PARAM_IPV4_ADDRESS:
521 	        return  AF_INET;
522 	case SCTP_PARAM_IPV6_ADDRESS:
523 		return AF_INET6;
524 	default:
525 		return 0;
526 	};
527 }
528 
529 /* Perform some sanity checks. */
530 static inline int sctp_sanity_check(void)
531 {
532 	SCTP_ASSERT(sizeof(struct sctp_ulpevent) <=
533 		    sizeof(((struct sk_buff *)0)->cb),
534 		    "SCTP: ulpevent does not fit in skb!\n", return 0);
535 
536 	return 1;
537 }
538 
539 /* Warning: The following hash functions assume a power of two 'size'. */
540 /* This is the hash function for the SCTP port hash table. */
541 static inline int sctp_phashfn(__u16 lport)
542 {
543 	return (lport & (sctp_port_hashsize - 1));
544 }
545 
546 /* This is the hash function for the endpoint hash table. */
547 static inline int sctp_ep_hashfn(__u16 lport)
548 {
549 	return (lport & (sctp_ep_hashsize - 1));
550 }
551 
552 /* This is the hash function for the association hash table. */
553 static inline int sctp_assoc_hashfn(__u16 lport, __u16 rport)
554 {
555 	int h = (lport << 16) + rport;
556 	h ^= h>>8;
557 	return (h & (sctp_assoc_hashsize - 1));
558 }
559 
560 /* This is the hash function for the association hash table.  This is
561  * not used yet, but could be used as a better hash function when
562  * we have a vtag.
563  */
564 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
565 {
566 	int h = (lport << 16) + rport;
567 	h ^= vtag;
568 	return (h & (sctp_assoc_hashsize-1));
569 }
570 
571 /* Is a socket of this style? */
572 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
573 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
574 {
575 	return sctp_sk(sk)->type == style;
576 }
577 
578 /* Is the association in this state? */
579 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
580 static inline int __sctp_state(const struct sctp_association *asoc,
581 			       sctp_state_t state)
582 {
583 	return asoc->state == state;
584 }
585 
586 /* Is the socket in this state? */
587 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
588 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
589 {
590 	return sk->sk_state == state;
591 }
592 
593 /* Map v4-mapped v6 address back to v4 address */
594 static inline void sctp_v6_map_v4(union sctp_addr *addr)
595 {
596 	addr->v4.sin_family = AF_INET;
597 	addr->v4.sin_port = addr->v6.sin6_port;
598 	addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
599 }
600 
601 /* Map v4 address to v4-mapped v6 address */
602 static inline void sctp_v4_map_v6(union sctp_addr *addr)
603 {
604 	addr->v6.sin6_family = AF_INET6;
605 	addr->v6.sin6_port = addr->v4.sin_port;
606 	addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
607 	addr->v6.sin6_addr.s6_addr32[0] = 0;
608 	addr->v6.sin6_addr.s6_addr32[1] = 0;
609 	addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
610 }
611 
612 #endif /* __net_sctp_h__ */
613