xref: /openbmc/linux/include/net/sctp/sctp.h (revision 95e9fd10)
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 IS_ENABLED(CONFIG_IPV6)
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 int sctp_copy_local_addr_list(struct sctp_bind_addr *,
119 				     sctp_scope_t, gfp_t gfp,
120 				     int flags);
121 extern struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
122 extern int sctp_register_pf(struct sctp_pf *, sa_family_t);
123 extern void sctp_addr_wq_mgmt(struct sctp_sockaddr_entry *, int);
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 void sctp_data_ready(struct sock *sk, int len);
132 unsigned int sctp_poll(struct file *file, struct socket *sock,
133 		poll_table *wait);
134 void sctp_sock_rfree(struct sk_buff *skb);
135 void sctp_copy_sock(struct sock *newsk, struct sock *sk,
136 		    struct sctp_association *asoc);
137 extern struct percpu_counter sctp_sockets_allocated;
138 extern int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
139 
140 /*
141  * sctp/primitive.c
142  */
143 int sctp_primitive_ASSOCIATE(struct sctp_association *, void *arg);
144 int sctp_primitive_SHUTDOWN(struct sctp_association *, void *arg);
145 int sctp_primitive_ABORT(struct sctp_association *, void *arg);
146 int sctp_primitive_SEND(struct sctp_association *, void *arg);
147 int sctp_primitive_REQUESTHEARTBEAT(struct sctp_association *, void *arg);
148 int sctp_primitive_ASCONF(struct sctp_association *, void *arg);
149 
150 /*
151  * sctp/input.c
152  */
153 int sctp_rcv(struct sk_buff *skb);
154 void sctp_v4_err(struct sk_buff *skb, u32 info);
155 void sctp_hash_established(struct sctp_association *);
156 void sctp_unhash_established(struct sctp_association *);
157 void sctp_hash_endpoint(struct sctp_endpoint *);
158 void sctp_unhash_endpoint(struct sctp_endpoint *);
159 struct sock *sctp_err_lookup(int family, struct sk_buff *,
160 			     struct sctphdr *, struct sctp_association **,
161 			     struct sctp_transport **);
162 void sctp_err_finish(struct sock *, struct sctp_association *);
163 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
164 			   struct sctp_transport *t, __u32 pmtu);
165 void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
166 			struct sk_buff *);
167 void sctp_icmp_proto_unreachable(struct sock *sk,
168 				 struct sctp_association *asoc,
169 				 struct sctp_transport *t);
170 void sctp_backlog_migrate(struct sctp_association *assoc,
171 			  struct sock *oldsk, struct sock *newsk);
172 
173 /*
174  * sctp/proc.c
175  */
176 int sctp_snmp_proc_init(void);
177 void sctp_snmp_proc_exit(void);
178 int sctp_eps_proc_init(void);
179 void sctp_eps_proc_exit(void);
180 int sctp_assocs_proc_init(void);
181 void sctp_assocs_proc_exit(void);
182 int sctp_remaddr_proc_init(void);
183 void sctp_remaddr_proc_exit(void);
184 
185 
186 /*
187  * Module global variables
188  */
189 
190  /*
191   * sctp/protocol.c
192   */
193 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
194 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
195 
196 /*
197  *  Section:  Macros, externs, and inlines
198  */
199 
200 
201 #ifdef TEST_FRAME
202 #include <test_frame.h>
203 #else
204 
205 /* spin lock wrappers. */
206 #define sctp_spin_lock_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
207 #define sctp_spin_unlock_irqrestore(lock, flags)  \
208        spin_unlock_irqrestore(lock, flags)
209 #define sctp_local_bh_disable() local_bh_disable()
210 #define sctp_local_bh_enable()  local_bh_enable()
211 #define sctp_spin_lock(lock)    spin_lock(lock)
212 #define sctp_spin_unlock(lock)  spin_unlock(lock)
213 #define sctp_write_lock(lock)   write_lock(lock)
214 #define sctp_write_unlock(lock) write_unlock(lock)
215 #define sctp_read_lock(lock)    read_lock(lock)
216 #define sctp_read_unlock(lock)  read_unlock(lock)
217 
218 /* sock lock wrappers. */
219 #define sctp_lock_sock(sk)       lock_sock(sk)
220 #define sctp_release_sock(sk)    release_sock(sk)
221 #define sctp_bh_lock_sock(sk)    bh_lock_sock(sk)
222 #define sctp_bh_unlock_sock(sk)  bh_unlock_sock(sk)
223 
224 /* SCTP SNMP MIB stats handlers */
225 DECLARE_SNMP_STAT(struct sctp_mib, sctp_statistics);
226 #define SCTP_INC_STATS(field)      SNMP_INC_STATS(sctp_statistics, field)
227 #define SCTP_INC_STATS_BH(field)   SNMP_INC_STATS_BH(sctp_statistics, field)
228 #define SCTP_INC_STATS_USER(field) SNMP_INC_STATS_USER(sctp_statistics, field)
229 #define SCTP_DEC_STATS(field)      SNMP_DEC_STATS(sctp_statistics, field)
230 
231 #endif /* !TEST_FRAME */
232 
233 /* sctp mib definitions */
234 enum {
235 	SCTP_MIB_NUM = 0,
236 	SCTP_MIB_CURRESTAB,			/* CurrEstab */
237 	SCTP_MIB_ACTIVEESTABS,			/* ActiveEstabs */
238 	SCTP_MIB_PASSIVEESTABS,			/* PassiveEstabs */
239 	SCTP_MIB_ABORTEDS,			/* Aborteds */
240 	SCTP_MIB_SHUTDOWNS,			/* Shutdowns */
241 	SCTP_MIB_OUTOFBLUES,			/* OutOfBlues */
242 	SCTP_MIB_CHECKSUMERRORS,		/* ChecksumErrors */
243 	SCTP_MIB_OUTCTRLCHUNKS,			/* OutCtrlChunks */
244 	SCTP_MIB_OUTORDERCHUNKS,		/* OutOrderChunks */
245 	SCTP_MIB_OUTUNORDERCHUNKS,		/* OutUnorderChunks */
246 	SCTP_MIB_INCTRLCHUNKS,			/* InCtrlChunks */
247 	SCTP_MIB_INORDERCHUNKS,			/* InOrderChunks */
248 	SCTP_MIB_INUNORDERCHUNKS,		/* InUnorderChunks */
249 	SCTP_MIB_FRAGUSRMSGS,			/* FragUsrMsgs */
250 	SCTP_MIB_REASMUSRMSGS,			/* ReasmUsrMsgs */
251 	SCTP_MIB_OUTSCTPPACKS,			/* OutSCTPPacks */
252 	SCTP_MIB_INSCTPPACKS,			/* InSCTPPacks */
253 	SCTP_MIB_T1_INIT_EXPIREDS,
254 	SCTP_MIB_T1_COOKIE_EXPIREDS,
255 	SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
256 	SCTP_MIB_T3_RTX_EXPIREDS,
257 	SCTP_MIB_T4_RTO_EXPIREDS,
258 	SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
259 	SCTP_MIB_DELAY_SACK_EXPIREDS,
260 	SCTP_MIB_AUTOCLOSE_EXPIREDS,
261 	SCTP_MIB_T1_RETRANSMITS,
262 	SCTP_MIB_T3_RETRANSMITS,
263 	SCTP_MIB_PMTUD_RETRANSMITS,
264 	SCTP_MIB_FAST_RETRANSMITS,
265 	SCTP_MIB_IN_PKT_SOFTIRQ,
266 	SCTP_MIB_IN_PKT_BACKLOG,
267 	SCTP_MIB_IN_PKT_DISCARDS,
268 	SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
269 	__SCTP_MIB_MAX
270 };
271 
272 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
273 struct sctp_mib {
274         unsigned long   mibs[SCTP_MIB_MAX];
275 };
276 
277 
278 /* Print debugging messages.  */
279 #if SCTP_DEBUG
280 extern int sctp_debug_flag;
281 #define SCTP_DEBUG_PRINTK(fmt, args...)			\
282 do {							\
283 	if (sctp_debug_flag)				\
284 		printk(KERN_DEBUG pr_fmt(fmt), ##args);	\
285 } while (0)
286 #define SCTP_DEBUG_PRINTK_CONT(fmt, args...)		\
287 do {							\
288 	if (sctp_debug_flag)				\
289 		pr_cont(fmt, ##args);			\
290 } while (0)
291 #define SCTP_DEBUG_PRINTK_IPADDR(fmt_lead, fmt_trail,			\
292 				 args_lead, addr, args_trail...)	\
293 do {									\
294 	const union sctp_addr *_addr = (addr);				\
295 	if (sctp_debug_flag) {						\
296 		if (_addr->sa.sa_family == AF_INET6) {			\
297 			printk(KERN_DEBUG				\
298 			       pr_fmt(fmt_lead "%pI6" fmt_trail),	\
299 			       args_lead,				\
300 			       &_addr->v6.sin6_addr,			\
301 			       args_trail);				\
302 		} else {						\
303 			printk(KERN_DEBUG				\
304 			       pr_fmt(fmt_lead "%pI4" fmt_trail),	\
305 			       args_lead,				\
306 			       &_addr->v4.sin_addr.s_addr,		\
307 			       args_trail);				\
308 		}							\
309 	}								\
310 } while (0)
311 #define SCTP_ENABLE_DEBUG { sctp_debug_flag = 1; }
312 #define SCTP_DISABLE_DEBUG { sctp_debug_flag = 0; }
313 
314 #define SCTP_ASSERT(expr, str, func) \
315 	if (!(expr)) { \
316 		SCTP_DEBUG_PRINTK("Assertion Failed: %s(%s) at %s:%s:%d\n", \
317 			str, (#expr), __FILE__, __func__, __LINE__); \
318 		func; \
319 	}
320 
321 #else	/* SCTP_DEBUG */
322 
323 #define SCTP_DEBUG_PRINTK(whatever...)
324 #define SCTP_DEBUG_PRINTK_CONT(fmt, args...)
325 #define SCTP_DEBUG_PRINTK_IPADDR(whatever...)
326 #define SCTP_ENABLE_DEBUG
327 #define SCTP_DISABLE_DEBUG
328 #define SCTP_ASSERT(expr, str, func)
329 
330 #endif /* SCTP_DEBUG */
331 
332 
333 /*
334  * Macros for keeping a global reference of object allocations.
335  */
336 #ifdef CONFIG_SCTP_DBG_OBJCNT
337 
338 extern atomic_t sctp_dbg_objcnt_sock;
339 extern atomic_t sctp_dbg_objcnt_ep;
340 extern atomic_t sctp_dbg_objcnt_assoc;
341 extern atomic_t sctp_dbg_objcnt_transport;
342 extern atomic_t sctp_dbg_objcnt_chunk;
343 extern atomic_t sctp_dbg_objcnt_bind_addr;
344 extern atomic_t sctp_dbg_objcnt_bind_bucket;
345 extern atomic_t sctp_dbg_objcnt_addr;
346 extern atomic_t sctp_dbg_objcnt_ssnmap;
347 extern atomic_t sctp_dbg_objcnt_datamsg;
348 extern atomic_t sctp_dbg_objcnt_keys;
349 
350 /* Macros to atomically increment/decrement objcnt counters.  */
351 #define SCTP_DBG_OBJCNT_INC(name) \
352 atomic_inc(&sctp_dbg_objcnt_## name)
353 #define SCTP_DBG_OBJCNT_DEC(name) \
354 atomic_dec(&sctp_dbg_objcnt_## name)
355 #define SCTP_DBG_OBJCNT(name) \
356 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
357 
358 /* Macro to help create new entries in in the global array of
359  * objcnt counters.
360  */
361 #define SCTP_DBG_OBJCNT_ENTRY(name) \
362 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
363 
364 void sctp_dbg_objcnt_init(void);
365 void sctp_dbg_objcnt_exit(void);
366 
367 #else
368 
369 #define SCTP_DBG_OBJCNT_INC(name)
370 #define SCTP_DBG_OBJCNT_DEC(name)
371 
372 static inline void sctp_dbg_objcnt_init(void) { return; }
373 static inline void sctp_dbg_objcnt_exit(void) { return; }
374 
375 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
376 
377 #if defined CONFIG_SYSCTL
378 void sctp_sysctl_register(void);
379 void sctp_sysctl_unregister(void);
380 #else
381 static inline void sctp_sysctl_register(void) { return; }
382 static inline void sctp_sysctl_unregister(void) { return; }
383 #endif
384 
385 /* Size of Supported Address Parameter for 'x' address types. */
386 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
387 
388 #if IS_ENABLED(CONFIG_IPV6)
389 
390 void sctp_v6_pf_init(void);
391 void sctp_v6_pf_exit(void);
392 int sctp_v6_protosw_init(void);
393 void sctp_v6_protosw_exit(void);
394 int sctp_v6_add_protocol(void);
395 void sctp_v6_del_protocol(void);
396 
397 #else /* #ifdef defined(CONFIG_IPV6) */
398 
399 static inline void sctp_v6_pf_init(void) { return; }
400 static inline void sctp_v6_pf_exit(void) { return; }
401 static inline int sctp_v6_protosw_init(void) { return 0; }
402 static inline void sctp_v6_protosw_exit(void) { return; }
403 static inline int sctp_v6_add_protocol(void) { return 0; }
404 static inline void sctp_v6_del_protocol(void) { return; }
405 
406 #endif /* #if defined(CONFIG_IPV6) */
407 
408 
409 /* Map an association to an assoc_id. */
410 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
411 {
412 	return asoc ? asoc->assoc_id : 0;
413 }
414 
415 /* Look up the association by its id.  */
416 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
417 
418 int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
419 
420 /* A macro to walk a list of skbs.  */
421 #define sctp_skb_for_each(pos, head, tmp) \
422 	skb_queue_walk_safe(head, pos, tmp)
423 
424 /* A helper to append an entire skb list (list) to another (head). */
425 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
426 				      struct sk_buff_head *head)
427 {
428 	unsigned long flags;
429 
430 	sctp_spin_lock_irqsave(&head->lock, flags);
431 	sctp_spin_lock(&list->lock);
432 
433 	skb_queue_splice_tail_init(list, head);
434 
435 	sctp_spin_unlock(&list->lock);
436 	sctp_spin_unlock_irqrestore(&head->lock, flags);
437 }
438 
439 /**
440  *	sctp_list_dequeue - remove from the head of the queue
441  *	@list: list to dequeue from
442  *
443  *	Remove the head of the list. The head item is
444  *	returned or %NULL if the list is empty.
445  */
446 
447 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
448 {
449 	struct list_head *result = NULL;
450 
451 	if (list->next != list) {
452 		result = list->next;
453 		list->next = result->next;
454 		list->next->prev = list;
455 		INIT_LIST_HEAD(result);
456 	}
457 	return result;
458 }
459 
460 /* SCTP version of skb_set_owner_r.  We need this one because
461  * of the way we have to do receive buffer accounting on bundled
462  * chunks.
463  */
464 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
465 {
466 	struct sctp_ulpevent *event = sctp_skb2event(skb);
467 
468 	skb_orphan(skb);
469 	skb->sk = sk;
470 	skb->destructor = sctp_sock_rfree;
471 	atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
472 	/*
473 	 * This mimics the behavior of skb_set_owner_r
474 	 */
475 	sk->sk_forward_alloc -= event->rmem_len;
476 }
477 
478 /* Tests if the list has one and only one entry. */
479 static inline int sctp_list_single_entry(struct list_head *head)
480 {
481 	return (head->next != head) && (head->next == head->prev);
482 }
483 
484 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
485 static inline __s32 sctp_jitter(__u32 rto)
486 {
487 	static __u32 sctp_rand;
488 	__s32 ret;
489 
490 	/* Avoid divide by zero. */
491 	if (!rto)
492 		rto = 1;
493 
494 	sctp_rand += jiffies;
495 	sctp_rand ^= (sctp_rand << 12);
496 	sctp_rand ^= (sctp_rand >> 20);
497 
498 	/* Choose random number from 0 to rto, then move to -50% ~ +50%
499 	 * of rto.
500 	 */
501 	ret = sctp_rand % rto - (rto >> 1);
502 	return ret;
503 }
504 
505 /* Break down data chunks at this point.  */
506 static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
507 {
508 	struct sctp_sock *sp = sctp_sk(asoc->base.sk);
509 	int frag = pmtu;
510 
511 	frag -= sp->pf->af->net_header_len;
512 	frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
513 
514 	if (asoc->user_frag)
515 		frag = min_t(int, frag, asoc->user_frag);
516 
517 	frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
518 
519 	return frag;
520 }
521 
522 static inline void sctp_assoc_pending_pmtu(struct sock *sk, struct sctp_association *asoc)
523 {
524 
525 	sctp_assoc_sync_pmtu(sk, asoc);
526 	asoc->pmtu_pending = 0;
527 }
528 
529 /* Walk through a list of TLV parameters.  Don't trust the
530  * individual parameter lengths and instead depend on
531  * the chunk length to indicate when to stop.  Make sure
532  * there is room for a param header too.
533  */
534 #define sctp_walk_params(pos, chunk, member)\
535 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
536 
537 #define _sctp_walk_params(pos, chunk, end, member)\
538 for (pos.v = chunk->member;\
539      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
540      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
541      pos.v += WORD_ROUND(ntohs(pos.p->length)))
542 
543 #define sctp_walk_errors(err, chunk_hdr)\
544 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
545 
546 #define _sctp_walk_errors(err, chunk_hdr, end)\
547 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
548 	    sizeof(sctp_chunkhdr_t));\
549      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
550      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
551      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
552 
553 #define sctp_walk_fwdtsn(pos, chunk)\
554 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
555 
556 #define _sctp_walk_fwdtsn(pos, chunk, end)\
557 for (pos = chunk->subh.fwdtsn_hdr->skip;\
558      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
559      pos++)
560 
561 /* Round an int up to the next multiple of 4.  */
562 #define WORD_ROUND(s) (((s)+3)&~3)
563 
564 /* Make a new instance of type.  */
565 #define t_new(type, flags)	(type *)kzalloc(sizeof(type), flags)
566 
567 /* Compare two timevals.  */
568 #define tv_lt(s, t) \
569    (s.tv_sec < t.tv_sec || (s.tv_sec == t.tv_sec && s.tv_usec < t.tv_usec))
570 
571 /* Add tv1 to tv2. */
572 #define TIMEVAL_ADD(tv1, tv2) \
573 ({ \
574         suseconds_t usecs = (tv2).tv_usec + (tv1).tv_usec; \
575         time_t secs = (tv2).tv_sec + (tv1).tv_sec; \
576 \
577         if (usecs >= 1000000) { \
578                 usecs -= 1000000; \
579                 secs++; \
580         } \
581         (tv2).tv_sec = secs; \
582         (tv2).tv_usec = usecs; \
583 })
584 
585 /* External references. */
586 
587 extern struct proto sctp_prot;
588 extern struct proto sctpv6_prot;
589 extern struct proc_dir_entry *proc_net_sctp;
590 void sctp_put_port(struct sock *sk);
591 
592 extern struct idr sctp_assocs_id;
593 extern spinlock_t sctp_assocs_id_lock;
594 
595 /* Static inline functions. */
596 
597 /* Convert from an IP version number to an Address Family symbol.  */
598 static inline int ipver2af(__u8 ipver)
599 {
600 	switch (ipver) {
601 	case 4:
602 	        return  AF_INET;
603 	case 6:
604 		return AF_INET6;
605 	default:
606 		return 0;
607 	}
608 }
609 
610 /* Convert from an address parameter type to an address family.  */
611 static inline int param_type2af(__be16 type)
612 {
613 	switch (type) {
614 	case SCTP_PARAM_IPV4_ADDRESS:
615 	        return  AF_INET;
616 	case SCTP_PARAM_IPV6_ADDRESS:
617 		return AF_INET6;
618 	default:
619 		return 0;
620 	}
621 }
622 
623 /* Perform some sanity checks. */
624 static inline int sctp_sanity_check(void)
625 {
626 	SCTP_ASSERT(sizeof(struct sctp_ulpevent) <=
627 		    sizeof(((struct sk_buff *)0)->cb),
628 		    "SCTP: ulpevent does not fit in skb!\n", return 0);
629 
630 	return 1;
631 }
632 
633 /* Warning: The following hash functions assume a power of two 'size'. */
634 /* This is the hash function for the SCTP port hash table. */
635 static inline int sctp_phashfn(__u16 lport)
636 {
637 	return lport & (sctp_port_hashsize - 1);
638 }
639 
640 /* This is the hash function for the endpoint hash table. */
641 static inline int sctp_ep_hashfn(__u16 lport)
642 {
643 	return lport & (sctp_ep_hashsize - 1);
644 }
645 
646 /* This is the hash function for the association hash table. */
647 static inline int sctp_assoc_hashfn(__u16 lport, __u16 rport)
648 {
649 	int h = (lport << 16) + rport;
650 	h ^= h>>8;
651 	return h & (sctp_assoc_hashsize - 1);
652 }
653 
654 /* This is the hash function for the association hash table.  This is
655  * not used yet, but could be used as a better hash function when
656  * we have a vtag.
657  */
658 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
659 {
660 	int h = (lport << 16) + rport;
661 	h ^= vtag;
662 	return h & (sctp_assoc_hashsize - 1);
663 }
664 
665 #define sctp_for_each_hentry(epb, node, head) \
666 	hlist_for_each_entry(epb, node, head, node)
667 
668 /* Is a socket of this style? */
669 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
670 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
671 {
672 	return sctp_sk(sk)->type == style;
673 }
674 
675 /* Is the association in this state? */
676 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
677 static inline int __sctp_state(const struct sctp_association *asoc,
678 			       sctp_state_t state)
679 {
680 	return asoc->state == state;
681 }
682 
683 /* Is the socket in this state? */
684 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
685 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
686 {
687 	return sk->sk_state == state;
688 }
689 
690 /* Map v4-mapped v6 address back to v4 address */
691 static inline void sctp_v6_map_v4(union sctp_addr *addr)
692 {
693 	addr->v4.sin_family = AF_INET;
694 	addr->v4.sin_port = addr->v6.sin6_port;
695 	addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
696 }
697 
698 /* Map v4 address to v4-mapped v6 address */
699 static inline void sctp_v4_map_v6(union sctp_addr *addr)
700 {
701 	addr->v6.sin6_family = AF_INET6;
702 	addr->v6.sin6_port = addr->v4.sin_port;
703 	addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
704 	addr->v6.sin6_addr.s6_addr32[0] = 0;
705 	addr->v6.sin6_addr.s6_addr32[1] = 0;
706 	addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
707 }
708 
709 /* The cookie is always 0 since this is how it's used in the
710  * pmtu code.
711  */
712 static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
713 {
714 	if (t->dst && !dst_check(t->dst, 0)) {
715 		dst_release(t->dst);
716 		t->dst = NULL;
717 	}
718 
719 	return t->dst;
720 }
721 
722 #endif /* __net_sctp_h__ */
723