xref: /openbmc/linux/include/net/sctp/sctp.h (revision 7dd65feb)
1 /* SCTP kernel 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 implementation
8  *
9  * The base lksctp header.
10  *
11  * This SCTP 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  * This SCTP 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 #include <linux/types.h>
66 #include <linux/slab.h>
67 #include <linux/in.h>
68 #include <linux/tty.h>
69 #include <linux/proc_fs.h>
70 #include <linux/spinlock.h>
71 #include <linux/jiffies.h>
72 #include <linux/idr.h>
73 
74 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
75 #include <net/ipv6.h>
76 #include <net/ip6_route.h>
77 #endif
78 
79 #include <asm/uaccess.h>
80 #include <asm/page.h>
81 #include <net/sock.h>
82 #include <net/snmp.h>
83 #include <net/sctp/structs.h>
84 #include <net/sctp/constants.h>
85 
86 
87 /* Set SCTP_DEBUG flag via config if not already set. */
88 #ifndef SCTP_DEBUG
89 #ifdef CONFIG_SCTP_DBG_MSG
90 #define SCTP_DEBUG	1
91 #else
92 #define SCTP_DEBUG      0
93 #endif /* CONFIG_SCTP_DBG */
94 #endif /* SCTP_DEBUG */
95 
96 #ifdef CONFIG_IP_SCTP_MODULE
97 #define SCTP_PROTOSW_FLAG 0
98 #else /* static! */
99 #define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
100 #endif
101 
102 
103 /* Certain internal static functions need to be exported when
104  * compiled into the test frame.
105  */
106 #ifndef SCTP_STATIC
107 #define SCTP_STATIC static
108 #endif
109 
110 /*
111  * Function declarations.
112  */
113 
114 /*
115  * sctp/protocol.c
116  */
117 extern struct sock *sctp_get_ctl_sock(void);
118 extern void sctp_local_addr_free(struct rcu_head *head);
119 extern int sctp_copy_local_addr_list(struct sctp_bind_addr *,
120 				     sctp_scope_t, gfp_t gfp,
121 				     int flags);
122 extern struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
123 extern int sctp_register_pf(struct sctp_pf *, sa_family_t);
124 
125 /*
126  * sctp/socket.c
127  */
128 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
129 int sctp_inet_listen(struct socket *sock, int backlog);
130 void sctp_write_space(struct sock *sk);
131 unsigned int sctp_poll(struct file *file, struct socket *sock,
132 		poll_table *wait);
133 void sctp_sock_rfree(struct sk_buff *skb);
134 void sctp_copy_sock(struct sock *newsk, struct sock *sk,
135 		    struct sctp_association *asoc);
136 extern struct percpu_counter sctp_sockets_allocated;
137 
138 /*
139  * sctp/primitive.c
140  */
141 int sctp_primitive_ASSOCIATE(struct sctp_association *, void *arg);
142 int sctp_primitive_SHUTDOWN(struct sctp_association *, void *arg);
143 int sctp_primitive_ABORT(struct sctp_association *, void *arg);
144 int sctp_primitive_SEND(struct sctp_association *, void *arg);
145 int sctp_primitive_REQUESTHEARTBEAT(struct sctp_association *, void *arg);
146 int sctp_primitive_ASCONF(struct sctp_association *, void *arg);
147 
148 /*
149  * sctp/input.c
150  */
151 int sctp_rcv(struct sk_buff *skb);
152 void sctp_v4_err(struct sk_buff *skb, u32 info);
153 void sctp_hash_established(struct sctp_association *);
154 void sctp_unhash_established(struct sctp_association *);
155 void sctp_hash_endpoint(struct sctp_endpoint *);
156 void sctp_unhash_endpoint(struct sctp_endpoint *);
157 struct sock *sctp_err_lookup(int family, struct sk_buff *,
158 			     struct sctphdr *, struct sctp_association **,
159 			     struct sctp_transport **);
160 void sctp_err_finish(struct sock *, struct sctp_association *);
161 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
162 			   struct sctp_transport *t, __u32 pmtu);
163 void sctp_icmp_proto_unreachable(struct sock *sk,
164 				 struct sctp_association *asoc,
165 				 struct sctp_transport *t);
166 void sctp_backlog_migrate(struct sctp_association *assoc,
167 			  struct sock *oldsk, struct sock *newsk);
168 
169 /*
170  * sctp/proc.c
171  */
172 int sctp_snmp_proc_init(void);
173 void sctp_snmp_proc_exit(void);
174 int sctp_eps_proc_init(void);
175 void sctp_eps_proc_exit(void);
176 int sctp_assocs_proc_init(void);
177 void sctp_assocs_proc_exit(void);
178 int sctp_remaddr_proc_init(void);
179 void sctp_remaddr_proc_exit(void);
180 
181 
182 /*
183  * Module global variables
184  */
185 
186  /*
187   * sctp/protocol.c
188   */
189 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
190 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
191 
192 /*
193  *  Section:  Macros, externs, and inlines
194  */
195 
196 
197 #ifdef TEST_FRAME
198 #include <test_frame.h>
199 #else
200 
201 /* spin lock wrappers. */
202 #define sctp_spin_lock_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
203 #define sctp_spin_unlock_irqrestore(lock, flags)  \
204        spin_unlock_irqrestore(lock, flags)
205 #define sctp_local_bh_disable() local_bh_disable()
206 #define sctp_local_bh_enable()  local_bh_enable()
207 #define sctp_spin_lock(lock)    spin_lock(lock)
208 #define sctp_spin_unlock(lock)  spin_unlock(lock)
209 #define sctp_write_lock(lock)   write_lock(lock)
210 #define sctp_write_unlock(lock) write_unlock(lock)
211 #define sctp_read_lock(lock)    read_lock(lock)
212 #define sctp_read_unlock(lock)  read_unlock(lock)
213 
214 /* sock lock wrappers. */
215 #define sctp_lock_sock(sk)       lock_sock(sk)
216 #define sctp_release_sock(sk)    release_sock(sk)
217 #define sctp_bh_lock_sock(sk)    bh_lock_sock(sk)
218 #define sctp_bh_unlock_sock(sk)  bh_unlock_sock(sk)
219 
220 /* SCTP SNMP MIB stats handlers */
221 DECLARE_SNMP_STAT(struct sctp_mib, sctp_statistics);
222 #define SCTP_INC_STATS(field)      SNMP_INC_STATS(sctp_statistics, field)
223 #define SCTP_INC_STATS_BH(field)   SNMP_INC_STATS_BH(sctp_statistics, field)
224 #define SCTP_INC_STATS_USER(field) SNMP_INC_STATS_USER(sctp_statistics, field)
225 #define SCTP_DEC_STATS(field)      SNMP_DEC_STATS(sctp_statistics, field)
226 
227 #endif /* !TEST_FRAME */
228 
229 /* sctp mib definitions */
230 enum {
231 	SCTP_MIB_NUM = 0,
232 	SCTP_MIB_CURRESTAB,			/* CurrEstab */
233 	SCTP_MIB_ACTIVEESTABS,			/* ActiveEstabs */
234 	SCTP_MIB_PASSIVEESTABS,			/* PassiveEstabs */
235 	SCTP_MIB_ABORTEDS,			/* Aborteds */
236 	SCTP_MIB_SHUTDOWNS,			/* Shutdowns */
237 	SCTP_MIB_OUTOFBLUES,			/* OutOfBlues */
238 	SCTP_MIB_CHECKSUMERRORS,		/* ChecksumErrors */
239 	SCTP_MIB_OUTCTRLCHUNKS,			/* OutCtrlChunks */
240 	SCTP_MIB_OUTORDERCHUNKS,		/* OutOrderChunks */
241 	SCTP_MIB_OUTUNORDERCHUNKS,		/* OutUnorderChunks */
242 	SCTP_MIB_INCTRLCHUNKS,			/* InCtrlChunks */
243 	SCTP_MIB_INORDERCHUNKS,			/* InOrderChunks */
244 	SCTP_MIB_INUNORDERCHUNKS,		/* InUnorderChunks */
245 	SCTP_MIB_FRAGUSRMSGS,			/* FragUsrMsgs */
246 	SCTP_MIB_REASMUSRMSGS,			/* ReasmUsrMsgs */
247 	SCTP_MIB_OUTSCTPPACKS,			/* OutSCTPPacks */
248 	SCTP_MIB_INSCTPPACKS,			/* InSCTPPacks */
249 	SCTP_MIB_T1_INIT_EXPIREDS,
250 	SCTP_MIB_T1_COOKIE_EXPIREDS,
251 	SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
252 	SCTP_MIB_T3_RTX_EXPIREDS,
253 	SCTP_MIB_T4_RTO_EXPIREDS,
254 	SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
255 	SCTP_MIB_DELAY_SACK_EXPIREDS,
256 	SCTP_MIB_AUTOCLOSE_EXPIREDS,
257 	SCTP_MIB_T1_RETRANSMITS,
258 	SCTP_MIB_T3_RETRANSMITS,
259 	SCTP_MIB_PMTUD_RETRANSMITS,
260 	SCTP_MIB_FAST_RETRANSMITS,
261 	SCTP_MIB_IN_PKT_SOFTIRQ,
262 	SCTP_MIB_IN_PKT_BACKLOG,
263 	SCTP_MIB_IN_PKT_DISCARDS,
264 	SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
265 	__SCTP_MIB_MAX
266 };
267 
268 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
269 struct sctp_mib {
270         unsigned long   mibs[SCTP_MIB_MAX];
271 } __SNMP_MIB_ALIGN__;
272 
273 
274 /* Print debugging messages.  */
275 #if SCTP_DEBUG
276 extern int sctp_debug_flag;
277 #define SCTP_DEBUG_PRINTK(whatever...) \
278 	((void) (sctp_debug_flag && printk(KERN_DEBUG whatever)))
279 #define SCTP_DEBUG_PRINTK_IPADDR(lead, trail, leadparm, saddr, otherparms...) \
280 	if (sctp_debug_flag) { \
281 		if (saddr->sa.sa_family == AF_INET6) { \
282 			printk(KERN_DEBUG \
283 			       lead "%pI6" trail, \
284 			       leadparm, \
285 			       &saddr->v6.sin6_addr, \
286 			       otherparms); \
287 		} else { \
288 			printk(KERN_DEBUG \
289 			       lead "%pI4" trail, \
290 			       leadparm, \
291 			       &saddr->v4.sin_addr.s_addr, \
292 			       otherparms); \
293 		} \
294 	}
295 #define SCTP_ENABLE_DEBUG { sctp_debug_flag = 1; }
296 #define SCTP_DISABLE_DEBUG { sctp_debug_flag = 0; }
297 
298 #define SCTP_ASSERT(expr, str, func) \
299 	if (!(expr)) { \
300 		SCTP_DEBUG_PRINTK("Assertion Failed: %s(%s) at %s:%s:%d\n", \
301 			str, (#expr), __FILE__, __func__, __LINE__); \
302 		func; \
303 	}
304 
305 #else	/* SCTP_DEBUG */
306 
307 #define SCTP_DEBUG_PRINTK(whatever...)
308 #define SCTP_DEBUG_PRINTK_IPADDR(whatever...)
309 #define SCTP_ENABLE_DEBUG
310 #define SCTP_DISABLE_DEBUG
311 #define SCTP_ASSERT(expr, str, func)
312 
313 #endif /* SCTP_DEBUG */
314 
315 
316 /*
317  * Macros for keeping a global reference of object allocations.
318  */
319 #ifdef CONFIG_SCTP_DBG_OBJCNT
320 
321 extern atomic_t sctp_dbg_objcnt_sock;
322 extern atomic_t sctp_dbg_objcnt_ep;
323 extern atomic_t sctp_dbg_objcnt_assoc;
324 extern atomic_t sctp_dbg_objcnt_transport;
325 extern atomic_t sctp_dbg_objcnt_chunk;
326 extern atomic_t sctp_dbg_objcnt_bind_addr;
327 extern atomic_t sctp_dbg_objcnt_bind_bucket;
328 extern atomic_t sctp_dbg_objcnt_addr;
329 extern atomic_t sctp_dbg_objcnt_ssnmap;
330 extern atomic_t sctp_dbg_objcnt_datamsg;
331 extern atomic_t sctp_dbg_objcnt_keys;
332 
333 /* Macros to atomically increment/decrement objcnt counters.  */
334 #define SCTP_DBG_OBJCNT_INC(name) \
335 atomic_inc(&sctp_dbg_objcnt_## name)
336 #define SCTP_DBG_OBJCNT_DEC(name) \
337 atomic_dec(&sctp_dbg_objcnt_## name)
338 #define SCTP_DBG_OBJCNT(name) \
339 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
340 
341 /* Macro to help create new entries in in the global array of
342  * objcnt counters.
343  */
344 #define SCTP_DBG_OBJCNT_ENTRY(name) \
345 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
346 
347 void sctp_dbg_objcnt_init(void);
348 void sctp_dbg_objcnt_exit(void);
349 
350 #else
351 
352 #define SCTP_DBG_OBJCNT_INC(name)
353 #define SCTP_DBG_OBJCNT_DEC(name)
354 
355 static inline void sctp_dbg_objcnt_init(void) { return; }
356 static inline void sctp_dbg_objcnt_exit(void) { return; }
357 
358 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
359 
360 #if defined CONFIG_SYSCTL
361 void sctp_sysctl_register(void);
362 void sctp_sysctl_unregister(void);
363 #else
364 static inline void sctp_sysctl_register(void) { return; }
365 static inline void sctp_sysctl_unregister(void) { return; }
366 #endif
367 
368 /* Size of Supported Address Parameter for 'x' address types. */
369 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
370 
371 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
372 
373 void sctp_v6_pf_init(void);
374 void sctp_v6_pf_exit(void);
375 int sctp_v6_protosw_init(void);
376 void sctp_v6_protosw_exit(void);
377 int sctp_v6_add_protocol(void);
378 void sctp_v6_del_protocol(void);
379 
380 #else /* #ifdef defined(CONFIG_IPV6) */
381 
382 static inline void sctp_v6_pf_init(void) { return; }
383 static inline void sctp_v6_pf_exit(void) { return; }
384 static inline int sctp_v6_protosw_init(void) { return 0; }
385 static inline void sctp_v6_protosw_exit(void) { return; }
386 static inline int sctp_v6_add_protocol(void) { return 0; }
387 static inline void sctp_v6_del_protocol(void) { return; }
388 
389 #endif /* #if defined(CONFIG_IPV6) */
390 
391 
392 /* Map an association to an assoc_id. */
393 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
394 {
395 	return (asoc?asoc->assoc_id:0);
396 }
397 
398 /* Look up the association by its id.  */
399 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
400 
401 
402 /* A macro to walk a list of skbs.  */
403 #define sctp_skb_for_each(pos, head, tmp) \
404 	skb_queue_walk_safe(head, pos, tmp)
405 
406 /* A helper to append an entire skb list (list) to another (head). */
407 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
408 				      struct sk_buff_head *head)
409 {
410 	unsigned long flags;
411 
412 	sctp_spin_lock_irqsave(&head->lock, flags);
413 	sctp_spin_lock(&list->lock);
414 
415 	skb_queue_splice_tail_init(list, head);
416 
417 	sctp_spin_unlock(&list->lock);
418 	sctp_spin_unlock_irqrestore(&head->lock, flags);
419 }
420 
421 /**
422  *	sctp_list_dequeue - remove from the head of the queue
423  *	@list: list to dequeue from
424  *
425  *	Remove the head of the list. The head item is
426  *	returned or %NULL if the list is empty.
427  */
428 
429 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
430 {
431 	struct list_head *result = NULL;
432 
433 	if (list->next != list) {
434 		result = list->next;
435 		list->next = result->next;
436 		list->next->prev = list;
437 		INIT_LIST_HEAD(result);
438 	}
439 	return result;
440 }
441 
442 /* SCTP version of skb_set_owner_r.  We need this one because
443  * of the way we have to do receive buffer accounting on bundled
444  * chunks.
445  */
446 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
447 {
448 	struct sctp_ulpevent *event = sctp_skb2event(skb);
449 
450 	skb_orphan(skb);
451 	skb->sk = sk;
452 	skb->destructor = sctp_sock_rfree;
453 	atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
454 	/*
455 	 * This mimics the behavior of skb_set_owner_r
456 	 */
457 	sk->sk_forward_alloc -= event->rmem_len;
458 }
459 
460 /* Tests if the list has one and only one entry. */
461 static inline int sctp_list_single_entry(struct list_head *head)
462 {
463 	return ((head->next != head) && (head->next == head->prev));
464 }
465 
466 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
467 static inline __s32 sctp_jitter(__u32 rto)
468 {
469 	static __u32 sctp_rand;
470 	__s32 ret;
471 
472 	/* Avoid divide by zero. */
473 	if (!rto)
474 		rto = 1;
475 
476 	sctp_rand += jiffies;
477 	sctp_rand ^= (sctp_rand << 12);
478 	sctp_rand ^= (sctp_rand >> 20);
479 
480 	/* Choose random number from 0 to rto, then move to -50% ~ +50%
481 	 * of rto.
482 	 */
483 	ret = sctp_rand % rto - (rto >> 1);
484 	return ret;
485 }
486 
487 /* Break down data chunks at this point.  */
488 static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
489 {
490 	struct sctp_sock *sp = sctp_sk(asoc->base.sk);
491 	int frag = pmtu;
492 
493 	frag -= sp->pf->af->net_header_len;
494 	frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
495 
496 	if (asoc->user_frag)
497 		frag = min_t(int, frag, asoc->user_frag);
498 
499 	frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
500 
501 	return frag;
502 }
503 
504 static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc)
505 {
506 
507 	sctp_assoc_sync_pmtu(asoc);
508 	asoc->pmtu_pending = 0;
509 }
510 
511 /* Walk through a list of TLV parameters.  Don't trust the
512  * individual parameter lengths and instead depend on
513  * the chunk length to indicate when to stop.  Make sure
514  * there is room for a param header too.
515  */
516 #define sctp_walk_params(pos, chunk, member)\
517 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
518 
519 #define _sctp_walk_params(pos, chunk, end, member)\
520 for (pos.v = chunk->member;\
521      pos.v <= (void *)chunk + end - sizeof(sctp_paramhdr_t) &&\
522      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
523      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
524      pos.v += WORD_ROUND(ntohs(pos.p->length)))
525 
526 #define sctp_walk_errors(err, chunk_hdr)\
527 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
528 
529 #define _sctp_walk_errors(err, chunk_hdr, end)\
530 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
531 	    sizeof(sctp_chunkhdr_t));\
532      (void *)err <= (void *)chunk_hdr + end - sizeof(sctp_errhdr_t) &&\
533      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
534      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
535      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
536 
537 #define sctp_walk_fwdtsn(pos, chunk)\
538 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
539 
540 #define _sctp_walk_fwdtsn(pos, chunk, end)\
541 for (pos = chunk->subh.fwdtsn_hdr->skip;\
542      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
543      pos++)
544 
545 /* Round an int up to the next multiple of 4.  */
546 #define WORD_ROUND(s) (((s)+3)&~3)
547 
548 /* Make a new instance of type.  */
549 #define t_new(type, flags)	(type *)kmalloc(sizeof(type), flags)
550 
551 /* Compare two timevals.  */
552 #define tv_lt(s, t) \
553    (s.tv_sec < t.tv_sec || (s.tv_sec == t.tv_sec && s.tv_usec < t.tv_usec))
554 
555 /* Add tv1 to tv2. */
556 #define TIMEVAL_ADD(tv1, tv2) \
557 ({ \
558         suseconds_t usecs = (tv2).tv_usec + (tv1).tv_usec; \
559         time_t secs = (tv2).tv_sec + (tv1).tv_sec; \
560 \
561         if (usecs >= 1000000) { \
562                 usecs -= 1000000; \
563                 secs++; \
564         } \
565         (tv2).tv_sec = secs; \
566         (tv2).tv_usec = usecs; \
567 })
568 
569 /* External references. */
570 
571 extern struct proto sctp_prot;
572 extern struct proto sctpv6_prot;
573 extern struct proc_dir_entry *proc_net_sctp;
574 void sctp_put_port(struct sock *sk);
575 
576 extern struct idr sctp_assocs_id;
577 extern spinlock_t sctp_assocs_id_lock;
578 
579 /* Static inline functions. */
580 
581 /* Convert from an IP version number to an Address Family symbol.  */
582 static inline int ipver2af(__u8 ipver)
583 {
584 	switch (ipver) {
585 	case 4:
586 	        return  AF_INET;
587 	case 6:
588 		return AF_INET6;
589 	default:
590 		return 0;
591 	};
592 }
593 
594 /* Convert from an address parameter type to an address family.  */
595 static inline int param_type2af(__be16 type)
596 {
597 	switch (type) {
598 	case SCTP_PARAM_IPV4_ADDRESS:
599 	        return  AF_INET;
600 	case SCTP_PARAM_IPV6_ADDRESS:
601 		return AF_INET6;
602 	default:
603 		return 0;
604 	};
605 }
606 
607 /* Perform some sanity checks. */
608 static inline int sctp_sanity_check(void)
609 {
610 	SCTP_ASSERT(sizeof(struct sctp_ulpevent) <=
611 		    sizeof(((struct sk_buff *)0)->cb),
612 		    "SCTP: ulpevent does not fit in skb!\n", return 0);
613 
614 	return 1;
615 }
616 
617 /* Warning: The following hash functions assume a power of two 'size'. */
618 /* This is the hash function for the SCTP port hash table. */
619 static inline int sctp_phashfn(__u16 lport)
620 {
621 	return (lport & (sctp_port_hashsize - 1));
622 }
623 
624 /* This is the hash function for the endpoint hash table. */
625 static inline int sctp_ep_hashfn(__u16 lport)
626 {
627 	return (lport & (sctp_ep_hashsize - 1));
628 }
629 
630 /* This is the hash function for the association hash table. */
631 static inline int sctp_assoc_hashfn(__u16 lport, __u16 rport)
632 {
633 	int h = (lport << 16) + rport;
634 	h ^= h>>8;
635 	return (h & (sctp_assoc_hashsize - 1));
636 }
637 
638 /* This is the hash function for the association hash table.  This is
639  * not used yet, but could be used as a better hash function when
640  * we have a vtag.
641  */
642 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
643 {
644 	int h = (lport << 16) + rport;
645 	h ^= vtag;
646 	return (h & (sctp_assoc_hashsize-1));
647 }
648 
649 #define sctp_for_each_hentry(epb, node, head) \
650 	hlist_for_each_entry(epb, node, head, node)
651 
652 /* Is a socket of this style? */
653 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
654 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
655 {
656 	return sctp_sk(sk)->type == style;
657 }
658 
659 /* Is the association in this state? */
660 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
661 static inline int __sctp_state(const struct sctp_association *asoc,
662 			       sctp_state_t state)
663 {
664 	return asoc->state == state;
665 }
666 
667 /* Is the socket in this state? */
668 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
669 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
670 {
671 	return sk->sk_state == state;
672 }
673 
674 /* Map v4-mapped v6 address back to v4 address */
675 static inline void sctp_v6_map_v4(union sctp_addr *addr)
676 {
677 	addr->v4.sin_family = AF_INET;
678 	addr->v4.sin_port = addr->v6.sin6_port;
679 	addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
680 }
681 
682 /* Map v4 address to v4-mapped v6 address */
683 static inline void sctp_v4_map_v6(union sctp_addr *addr)
684 {
685 	addr->v6.sin6_family = AF_INET6;
686 	addr->v6.sin6_port = addr->v4.sin_port;
687 	addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
688 	addr->v6.sin6_addr.s6_addr32[0] = 0;
689 	addr->v6.sin6_addr.s6_addr32[1] = 0;
690 	addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
691 }
692 
693 #endif /* __net_sctp_h__ */
694