xref: /openbmc/linux/include/net/sctp/sctp.h (revision 9d749629)
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 int sctp_copy_local_addr_list(struct net *, struct sctp_bind_addr *,
118 				     sctp_scope_t, gfp_t gfp,
119 				     int flags);
120 extern struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
121 extern int sctp_register_pf(struct sctp_pf *, sa_family_t);
122 extern void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
123 
124 /*
125  * sctp/socket.c
126  */
127 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
128 int sctp_inet_listen(struct socket *sock, int backlog);
129 void sctp_write_space(struct sock *sk);
130 void sctp_data_ready(struct sock *sk, int len);
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 extern int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
138 
139 /*
140  * sctp/primitive.c
141  */
142 int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
143 int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
144 int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
145 int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
146 int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
147 int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
148 
149 /*
150  * sctp/input.c
151  */
152 int sctp_rcv(struct sk_buff *skb);
153 void sctp_v4_err(struct sk_buff *skb, u32 info);
154 void sctp_hash_established(struct sctp_association *);
155 void sctp_unhash_established(struct sctp_association *);
156 void sctp_hash_endpoint(struct sctp_endpoint *);
157 void sctp_unhash_endpoint(struct sctp_endpoint *);
158 struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
159 			     struct sctphdr *, struct sctp_association **,
160 			     struct sctp_transport **);
161 void sctp_err_finish(struct sock *, struct sctp_association *);
162 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
163 			   struct sctp_transport *t, __u32 pmtu);
164 void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
165 			struct sk_buff *);
166 void sctp_icmp_proto_unreachable(struct sock *sk,
167 				 struct sctp_association *asoc,
168 				 struct sctp_transport *t);
169 void sctp_backlog_migrate(struct sctp_association *assoc,
170 			  struct sock *oldsk, struct sock *newsk);
171 
172 /*
173  * sctp/proc.c
174  */
175 int sctp_snmp_proc_init(struct net *net);
176 void sctp_snmp_proc_exit(struct net *net);
177 int sctp_eps_proc_init(struct net *net);
178 void sctp_eps_proc_exit(struct net *net);
179 int sctp_assocs_proc_init(struct net *net);
180 void sctp_assocs_proc_exit(struct net *net);
181 int sctp_remaddr_proc_init(struct net *net);
182 void sctp_remaddr_proc_exit(struct net *net);
183 
184 
185 /*
186  * Module global variables
187  */
188 
189  /*
190   * sctp/protocol.c
191   */
192 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
193 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
194 
195 /*
196  *  Section:  Macros, externs, and inlines
197  */
198 
199 
200 #ifdef TEST_FRAME
201 #include <test_frame.h>
202 #else
203 
204 /* spin lock wrappers. */
205 #define sctp_spin_lock_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
206 #define sctp_spin_unlock_irqrestore(lock, flags)  \
207        spin_unlock_irqrestore(lock, flags)
208 #define sctp_local_bh_disable() local_bh_disable()
209 #define sctp_local_bh_enable()  local_bh_enable()
210 #define sctp_spin_lock(lock)    spin_lock(lock)
211 #define sctp_spin_unlock(lock)  spin_unlock(lock)
212 #define sctp_write_lock(lock)   write_lock(lock)
213 #define sctp_write_unlock(lock) write_unlock(lock)
214 #define sctp_read_lock(lock)    read_lock(lock)
215 #define sctp_read_unlock(lock)  read_unlock(lock)
216 
217 /* sock lock wrappers. */
218 #define sctp_lock_sock(sk)       lock_sock(sk)
219 #define sctp_release_sock(sk)    release_sock(sk)
220 #define sctp_bh_lock_sock(sk)    bh_lock_sock(sk)
221 #define sctp_bh_unlock_sock(sk)  bh_unlock_sock(sk)
222 
223 /* SCTP SNMP MIB stats handlers */
224 #define SCTP_INC_STATS(net, field)      SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
225 #define SCTP_INC_STATS_BH(net, field)   SNMP_INC_STATS_BH((net)->sctp.sctp_statistics, field)
226 #define SCTP_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->sctp.sctp_statistics, field)
227 #define SCTP_DEC_STATS(net, field)      SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
228 
229 #endif /* !TEST_FRAME */
230 
231 /* sctp mib definitions */
232 enum {
233 	SCTP_MIB_NUM = 0,
234 	SCTP_MIB_CURRESTAB,			/* CurrEstab */
235 	SCTP_MIB_ACTIVEESTABS,			/* ActiveEstabs */
236 	SCTP_MIB_PASSIVEESTABS,			/* PassiveEstabs */
237 	SCTP_MIB_ABORTEDS,			/* Aborteds */
238 	SCTP_MIB_SHUTDOWNS,			/* Shutdowns */
239 	SCTP_MIB_OUTOFBLUES,			/* OutOfBlues */
240 	SCTP_MIB_CHECKSUMERRORS,		/* ChecksumErrors */
241 	SCTP_MIB_OUTCTRLCHUNKS,			/* OutCtrlChunks */
242 	SCTP_MIB_OUTORDERCHUNKS,		/* OutOrderChunks */
243 	SCTP_MIB_OUTUNORDERCHUNKS,		/* OutUnorderChunks */
244 	SCTP_MIB_INCTRLCHUNKS,			/* InCtrlChunks */
245 	SCTP_MIB_INORDERCHUNKS,			/* InOrderChunks */
246 	SCTP_MIB_INUNORDERCHUNKS,		/* InUnorderChunks */
247 	SCTP_MIB_FRAGUSRMSGS,			/* FragUsrMsgs */
248 	SCTP_MIB_REASMUSRMSGS,			/* ReasmUsrMsgs */
249 	SCTP_MIB_OUTSCTPPACKS,			/* OutSCTPPacks */
250 	SCTP_MIB_INSCTPPACKS,			/* InSCTPPacks */
251 	SCTP_MIB_T1_INIT_EXPIREDS,
252 	SCTP_MIB_T1_COOKIE_EXPIREDS,
253 	SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
254 	SCTP_MIB_T3_RTX_EXPIREDS,
255 	SCTP_MIB_T4_RTO_EXPIREDS,
256 	SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
257 	SCTP_MIB_DELAY_SACK_EXPIREDS,
258 	SCTP_MIB_AUTOCLOSE_EXPIREDS,
259 	SCTP_MIB_T1_RETRANSMITS,
260 	SCTP_MIB_T3_RETRANSMITS,
261 	SCTP_MIB_PMTUD_RETRANSMITS,
262 	SCTP_MIB_FAST_RETRANSMITS,
263 	SCTP_MIB_IN_PKT_SOFTIRQ,
264 	SCTP_MIB_IN_PKT_BACKLOG,
265 	SCTP_MIB_IN_PKT_DISCARDS,
266 	SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
267 	__SCTP_MIB_MAX
268 };
269 
270 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
271 struct sctp_mib {
272         unsigned long   mibs[SCTP_MIB_MAX];
273 };
274 
275 /* helper function to track stats about max rto and related transport */
276 static inline void sctp_max_rto(struct sctp_association *asoc,
277 				struct sctp_transport *trans)
278 {
279 	if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
280 		asoc->stats.max_obs_rto = trans->rto;
281 		memset(&asoc->stats.obs_rto_ipaddr, 0,
282 			sizeof(struct sockaddr_storage));
283 		memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
284 			trans->af_specific->sockaddr_len);
285 	}
286 }
287 
288 /* Print debugging messages.  */
289 #if SCTP_DEBUG
290 extern int sctp_debug_flag;
291 #define SCTP_DEBUG_PRINTK(fmt, args...)			\
292 do {							\
293 	if (sctp_debug_flag)				\
294 		printk(KERN_DEBUG pr_fmt(fmt), ##args);	\
295 } while (0)
296 #define SCTP_DEBUG_PRINTK_CONT(fmt, args...)		\
297 do {							\
298 	if (sctp_debug_flag)				\
299 		pr_cont(fmt, ##args);			\
300 } while (0)
301 #define SCTP_DEBUG_PRINTK_IPADDR(fmt_lead, fmt_trail,			\
302 				 args_lead, addr, args_trail...)	\
303 do {									\
304 	const union sctp_addr *_addr = (addr);				\
305 	if (sctp_debug_flag) {						\
306 		if (_addr->sa.sa_family == AF_INET6) {			\
307 			printk(KERN_DEBUG				\
308 			       pr_fmt(fmt_lead "%pI6" fmt_trail),	\
309 			       args_lead,				\
310 			       &_addr->v6.sin6_addr,			\
311 			       args_trail);				\
312 		} else {						\
313 			printk(KERN_DEBUG				\
314 			       pr_fmt(fmt_lead "%pI4" fmt_trail),	\
315 			       args_lead,				\
316 			       &_addr->v4.sin_addr.s_addr,		\
317 			       args_trail);				\
318 		}							\
319 	}								\
320 } while (0)
321 #define SCTP_ENABLE_DEBUG { sctp_debug_flag = 1; }
322 #define SCTP_DISABLE_DEBUG { sctp_debug_flag = 0; }
323 
324 #define SCTP_ASSERT(expr, str, func) \
325 	if (!(expr)) { \
326 		SCTP_DEBUG_PRINTK("Assertion Failed: %s(%s) at %s:%s:%d\n", \
327 			str, (#expr), __FILE__, __func__, __LINE__); \
328 		func; \
329 	}
330 
331 #else	/* SCTP_DEBUG */
332 
333 #define SCTP_DEBUG_PRINTK(whatever...)
334 #define SCTP_DEBUG_PRINTK_CONT(fmt, args...)
335 #define SCTP_DEBUG_PRINTK_IPADDR(whatever...)
336 #define SCTP_ENABLE_DEBUG
337 #define SCTP_DISABLE_DEBUG
338 #define SCTP_ASSERT(expr, str, func)
339 
340 #endif /* SCTP_DEBUG */
341 
342 
343 /*
344  * Macros for keeping a global reference of object allocations.
345  */
346 #ifdef CONFIG_SCTP_DBG_OBJCNT
347 
348 extern atomic_t sctp_dbg_objcnt_sock;
349 extern atomic_t sctp_dbg_objcnt_ep;
350 extern atomic_t sctp_dbg_objcnt_assoc;
351 extern atomic_t sctp_dbg_objcnt_transport;
352 extern atomic_t sctp_dbg_objcnt_chunk;
353 extern atomic_t sctp_dbg_objcnt_bind_addr;
354 extern atomic_t sctp_dbg_objcnt_bind_bucket;
355 extern atomic_t sctp_dbg_objcnt_addr;
356 extern atomic_t sctp_dbg_objcnt_ssnmap;
357 extern atomic_t sctp_dbg_objcnt_datamsg;
358 extern atomic_t sctp_dbg_objcnt_keys;
359 
360 /* Macros to atomically increment/decrement objcnt counters.  */
361 #define SCTP_DBG_OBJCNT_INC(name) \
362 atomic_inc(&sctp_dbg_objcnt_## name)
363 #define SCTP_DBG_OBJCNT_DEC(name) \
364 atomic_dec(&sctp_dbg_objcnt_## name)
365 #define SCTP_DBG_OBJCNT(name) \
366 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
367 
368 /* Macro to help create new entries in in the global array of
369  * objcnt counters.
370  */
371 #define SCTP_DBG_OBJCNT_ENTRY(name) \
372 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
373 
374 void sctp_dbg_objcnt_init(struct net *);
375 void sctp_dbg_objcnt_exit(struct net *);
376 
377 #else
378 
379 #define SCTP_DBG_OBJCNT_INC(name)
380 #define SCTP_DBG_OBJCNT_DEC(name)
381 
382 static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
383 static inline void sctp_dbg_objcnt_exit(struct net *net) { return; }
384 
385 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
386 
387 #if defined CONFIG_SYSCTL
388 void sctp_sysctl_register(void);
389 void sctp_sysctl_unregister(void);
390 int sctp_sysctl_net_register(struct net *net);
391 void sctp_sysctl_net_unregister(struct net *net);
392 #else
393 static inline void sctp_sysctl_register(void) { return; }
394 static inline void sctp_sysctl_unregister(void) { return; }
395 static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
396 static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
397 #endif
398 
399 /* Size of Supported Address Parameter for 'x' address types. */
400 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
401 
402 #if IS_ENABLED(CONFIG_IPV6)
403 
404 void sctp_v6_pf_init(void);
405 void sctp_v6_pf_exit(void);
406 int sctp_v6_protosw_init(void);
407 void sctp_v6_protosw_exit(void);
408 int sctp_v6_add_protocol(void);
409 void sctp_v6_del_protocol(void);
410 
411 #else /* #ifdef defined(CONFIG_IPV6) */
412 
413 static inline void sctp_v6_pf_init(void) { return; }
414 static inline void sctp_v6_pf_exit(void) { return; }
415 static inline int sctp_v6_protosw_init(void) { return 0; }
416 static inline void sctp_v6_protosw_exit(void) { return; }
417 static inline int sctp_v6_add_protocol(void) { return 0; }
418 static inline void sctp_v6_del_protocol(void) { return; }
419 
420 #endif /* #if defined(CONFIG_IPV6) */
421 
422 
423 /* Map an association to an assoc_id. */
424 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
425 {
426 	return asoc ? asoc->assoc_id : 0;
427 }
428 
429 /* Look up the association by its id.  */
430 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
431 
432 int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
433 
434 /* A macro to walk a list of skbs.  */
435 #define sctp_skb_for_each(pos, head, tmp) \
436 	skb_queue_walk_safe(head, pos, tmp)
437 
438 /* A helper to append an entire skb list (list) to another (head). */
439 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
440 				      struct sk_buff_head *head)
441 {
442 	unsigned long flags;
443 
444 	sctp_spin_lock_irqsave(&head->lock, flags);
445 	sctp_spin_lock(&list->lock);
446 
447 	skb_queue_splice_tail_init(list, head);
448 
449 	sctp_spin_unlock(&list->lock);
450 	sctp_spin_unlock_irqrestore(&head->lock, flags);
451 }
452 
453 /**
454  *	sctp_list_dequeue - remove from the head of the queue
455  *	@list: list to dequeue from
456  *
457  *	Remove the head of the list. The head item is
458  *	returned or %NULL if the list is empty.
459  */
460 
461 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
462 {
463 	struct list_head *result = NULL;
464 
465 	if (list->next != list) {
466 		result = list->next;
467 		list->next = result->next;
468 		list->next->prev = list;
469 		INIT_LIST_HEAD(result);
470 	}
471 	return result;
472 }
473 
474 /* SCTP version of skb_set_owner_r.  We need this one because
475  * of the way we have to do receive buffer accounting on bundled
476  * chunks.
477  */
478 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
479 {
480 	struct sctp_ulpevent *event = sctp_skb2event(skb);
481 
482 	skb_orphan(skb);
483 	skb->sk = sk;
484 	skb->destructor = sctp_sock_rfree;
485 	atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
486 	/*
487 	 * This mimics the behavior of skb_set_owner_r
488 	 */
489 	sk->sk_forward_alloc -= event->rmem_len;
490 }
491 
492 /* Tests if the list has one and only one entry. */
493 static inline int sctp_list_single_entry(struct list_head *head)
494 {
495 	return (head->next != head) && (head->next == head->prev);
496 }
497 
498 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
499 static inline __s32 sctp_jitter(__u32 rto)
500 {
501 	static __u32 sctp_rand;
502 	__s32 ret;
503 
504 	/* Avoid divide by zero. */
505 	if (!rto)
506 		rto = 1;
507 
508 	sctp_rand += jiffies;
509 	sctp_rand ^= (sctp_rand << 12);
510 	sctp_rand ^= (sctp_rand >> 20);
511 
512 	/* Choose random number from 0 to rto, then move to -50% ~ +50%
513 	 * of rto.
514 	 */
515 	ret = sctp_rand % rto - (rto >> 1);
516 	return ret;
517 }
518 
519 /* Break down data chunks at this point.  */
520 static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
521 {
522 	struct sctp_sock *sp = sctp_sk(asoc->base.sk);
523 	int frag = pmtu;
524 
525 	frag -= sp->pf->af->net_header_len;
526 	frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
527 
528 	if (asoc->user_frag)
529 		frag = min_t(int, frag, asoc->user_frag);
530 
531 	frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
532 
533 	return frag;
534 }
535 
536 static inline void sctp_assoc_pending_pmtu(struct sock *sk, struct sctp_association *asoc)
537 {
538 
539 	sctp_assoc_sync_pmtu(sk, asoc);
540 	asoc->pmtu_pending = 0;
541 }
542 
543 /* Walk through a list of TLV parameters.  Don't trust the
544  * individual parameter lengths and instead depend on
545  * the chunk length to indicate when to stop.  Make sure
546  * there is room for a param header too.
547  */
548 #define sctp_walk_params(pos, chunk, member)\
549 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
550 
551 #define _sctp_walk_params(pos, chunk, end, member)\
552 for (pos.v = chunk->member;\
553      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
554      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
555      pos.v += WORD_ROUND(ntohs(pos.p->length)))
556 
557 #define sctp_walk_errors(err, chunk_hdr)\
558 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
559 
560 #define _sctp_walk_errors(err, chunk_hdr, end)\
561 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
562 	    sizeof(sctp_chunkhdr_t));\
563      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
564      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
565      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
566 
567 #define sctp_walk_fwdtsn(pos, chunk)\
568 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
569 
570 #define _sctp_walk_fwdtsn(pos, chunk, end)\
571 for (pos = chunk->subh.fwdtsn_hdr->skip;\
572      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
573      pos++)
574 
575 /* Round an int up to the next multiple of 4.  */
576 #define WORD_ROUND(s) (((s)+3)&~3)
577 
578 /* Make a new instance of type.  */
579 #define t_new(type, flags)	(type *)kzalloc(sizeof(type), flags)
580 
581 /* Compare two timevals.  */
582 #define tv_lt(s, t) \
583    (s.tv_sec < t.tv_sec || (s.tv_sec == t.tv_sec && s.tv_usec < t.tv_usec))
584 
585 /* Add tv1 to tv2. */
586 #define TIMEVAL_ADD(tv1, tv2) \
587 ({ \
588         suseconds_t usecs = (tv2).tv_usec + (tv1).tv_usec; \
589         time_t secs = (tv2).tv_sec + (tv1).tv_sec; \
590 \
591         if (usecs >= 1000000) { \
592                 usecs -= 1000000; \
593                 secs++; \
594         } \
595         (tv2).tv_sec = secs; \
596         (tv2).tv_usec = usecs; \
597 })
598 
599 /* External references. */
600 
601 extern struct proto sctp_prot;
602 extern struct proto sctpv6_prot;
603 void sctp_put_port(struct sock *sk);
604 
605 extern struct idr sctp_assocs_id;
606 extern spinlock_t sctp_assocs_id_lock;
607 
608 /* Static inline functions. */
609 
610 /* Convert from an IP version number to an Address Family symbol.  */
611 static inline int ipver2af(__u8 ipver)
612 {
613 	switch (ipver) {
614 	case 4:
615 	        return  AF_INET;
616 	case 6:
617 		return AF_INET6;
618 	default:
619 		return 0;
620 	}
621 }
622 
623 /* Convert from an address parameter type to an address family.  */
624 static inline int param_type2af(__be16 type)
625 {
626 	switch (type) {
627 	case SCTP_PARAM_IPV4_ADDRESS:
628 	        return  AF_INET;
629 	case SCTP_PARAM_IPV6_ADDRESS:
630 		return AF_INET6;
631 	default:
632 		return 0;
633 	}
634 }
635 
636 /* Perform some sanity checks. */
637 static inline int sctp_sanity_check(void)
638 {
639 	SCTP_ASSERT(sizeof(struct sctp_ulpevent) <=
640 		    sizeof(((struct sk_buff *)0)->cb),
641 		    "SCTP: ulpevent does not fit in skb!\n", return 0);
642 
643 	return 1;
644 }
645 
646 /* Warning: The following hash functions assume a power of two 'size'. */
647 /* This is the hash function for the SCTP port hash table. */
648 static inline int sctp_phashfn(struct net *net, __u16 lport)
649 {
650 	return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
651 }
652 
653 /* This is the hash function for the endpoint hash table. */
654 static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
655 {
656 	return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
657 }
658 
659 /* This is the hash function for the association hash table. */
660 static inline int sctp_assoc_hashfn(struct net *net, __u16 lport, __u16 rport)
661 {
662 	int h = (lport << 16) + rport + net_hash_mix(net);
663 	h ^= h>>8;
664 	return h & (sctp_assoc_hashsize - 1);
665 }
666 
667 /* This is the hash function for the association hash table.  This is
668  * not used yet, but could be used as a better hash function when
669  * we have a vtag.
670  */
671 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
672 {
673 	int h = (lport << 16) + rport;
674 	h ^= vtag;
675 	return h & (sctp_assoc_hashsize - 1);
676 }
677 
678 #define sctp_for_each_hentry(epb, node, head) \
679 	hlist_for_each_entry(epb, node, head, node)
680 
681 /* Is a socket of this style? */
682 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
683 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
684 {
685 	return sctp_sk(sk)->type == style;
686 }
687 
688 /* Is the association in this state? */
689 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
690 static inline int __sctp_state(const struct sctp_association *asoc,
691 			       sctp_state_t state)
692 {
693 	return asoc->state == state;
694 }
695 
696 /* Is the socket in this state? */
697 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
698 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
699 {
700 	return sk->sk_state == state;
701 }
702 
703 /* Map v4-mapped v6 address back to v4 address */
704 static inline void sctp_v6_map_v4(union sctp_addr *addr)
705 {
706 	addr->v4.sin_family = AF_INET;
707 	addr->v4.sin_port = addr->v6.sin6_port;
708 	addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
709 }
710 
711 /* Map v4 address to v4-mapped v6 address */
712 static inline void sctp_v4_map_v6(union sctp_addr *addr)
713 {
714 	addr->v6.sin6_family = AF_INET6;
715 	addr->v6.sin6_port = addr->v4.sin_port;
716 	addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
717 	addr->v6.sin6_addr.s6_addr32[0] = 0;
718 	addr->v6.sin6_addr.s6_addr32[1] = 0;
719 	addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
720 }
721 
722 /* The cookie is always 0 since this is how it's used in the
723  * pmtu code.
724  */
725 static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
726 {
727 	if (t->dst && !dst_check(t->dst, 0)) {
728 		dst_release(t->dst);
729 		t->dst = NULL;
730 	}
731 
732 	return t->dst;
733 }
734 
735 #endif /* __net_sctp_h__ */
736