xref: /openbmc/linux/include/net/sctp/sctp.h (revision 3b64b188)
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 
276 /* Print debugging messages.  */
277 #if SCTP_DEBUG
278 extern int sctp_debug_flag;
279 #define SCTP_DEBUG_PRINTK(fmt, args...)			\
280 do {							\
281 	if (sctp_debug_flag)				\
282 		printk(KERN_DEBUG pr_fmt(fmt), ##args);	\
283 } while (0)
284 #define SCTP_DEBUG_PRINTK_CONT(fmt, args...)		\
285 do {							\
286 	if (sctp_debug_flag)				\
287 		pr_cont(fmt, ##args);			\
288 } while (0)
289 #define SCTP_DEBUG_PRINTK_IPADDR(fmt_lead, fmt_trail,			\
290 				 args_lead, addr, args_trail...)	\
291 do {									\
292 	const union sctp_addr *_addr = (addr);				\
293 	if (sctp_debug_flag) {						\
294 		if (_addr->sa.sa_family == AF_INET6) {			\
295 			printk(KERN_DEBUG				\
296 			       pr_fmt(fmt_lead "%pI6" fmt_trail),	\
297 			       args_lead,				\
298 			       &_addr->v6.sin6_addr,			\
299 			       args_trail);				\
300 		} else {						\
301 			printk(KERN_DEBUG				\
302 			       pr_fmt(fmt_lead "%pI4" fmt_trail),	\
303 			       args_lead,				\
304 			       &_addr->v4.sin_addr.s_addr,		\
305 			       args_trail);				\
306 		}							\
307 	}								\
308 } while (0)
309 #define SCTP_ENABLE_DEBUG { sctp_debug_flag = 1; }
310 #define SCTP_DISABLE_DEBUG { sctp_debug_flag = 0; }
311 
312 #define SCTP_ASSERT(expr, str, func) \
313 	if (!(expr)) { \
314 		SCTP_DEBUG_PRINTK("Assertion Failed: %s(%s) at %s:%s:%d\n", \
315 			str, (#expr), __FILE__, __func__, __LINE__); \
316 		func; \
317 	}
318 
319 #else	/* SCTP_DEBUG */
320 
321 #define SCTP_DEBUG_PRINTK(whatever...)
322 #define SCTP_DEBUG_PRINTK_CONT(fmt, args...)
323 #define SCTP_DEBUG_PRINTK_IPADDR(whatever...)
324 #define SCTP_ENABLE_DEBUG
325 #define SCTP_DISABLE_DEBUG
326 #define SCTP_ASSERT(expr, str, func)
327 
328 #endif /* SCTP_DEBUG */
329 
330 
331 /*
332  * Macros for keeping a global reference of object allocations.
333  */
334 #ifdef CONFIG_SCTP_DBG_OBJCNT
335 
336 extern atomic_t sctp_dbg_objcnt_sock;
337 extern atomic_t sctp_dbg_objcnt_ep;
338 extern atomic_t sctp_dbg_objcnt_assoc;
339 extern atomic_t sctp_dbg_objcnt_transport;
340 extern atomic_t sctp_dbg_objcnt_chunk;
341 extern atomic_t sctp_dbg_objcnt_bind_addr;
342 extern atomic_t sctp_dbg_objcnt_bind_bucket;
343 extern atomic_t sctp_dbg_objcnt_addr;
344 extern atomic_t sctp_dbg_objcnt_ssnmap;
345 extern atomic_t sctp_dbg_objcnt_datamsg;
346 extern atomic_t sctp_dbg_objcnt_keys;
347 
348 /* Macros to atomically increment/decrement objcnt counters.  */
349 #define SCTP_DBG_OBJCNT_INC(name) \
350 atomic_inc(&sctp_dbg_objcnt_## name)
351 #define SCTP_DBG_OBJCNT_DEC(name) \
352 atomic_dec(&sctp_dbg_objcnt_## name)
353 #define SCTP_DBG_OBJCNT(name) \
354 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
355 
356 /* Macro to help create new entries in in the global array of
357  * objcnt counters.
358  */
359 #define SCTP_DBG_OBJCNT_ENTRY(name) \
360 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
361 
362 void sctp_dbg_objcnt_init(struct net *);
363 void sctp_dbg_objcnt_exit(struct net *);
364 
365 #else
366 
367 #define SCTP_DBG_OBJCNT_INC(name)
368 #define SCTP_DBG_OBJCNT_DEC(name)
369 
370 static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
371 static inline void sctp_dbg_objcnt_exit(struct net *net) { return; }
372 
373 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
374 
375 #if defined CONFIG_SYSCTL
376 void sctp_sysctl_register(void);
377 void sctp_sysctl_unregister(void);
378 int sctp_sysctl_net_register(struct net *net);
379 void sctp_sysctl_net_unregister(struct net *net);
380 #else
381 static inline void sctp_sysctl_register(void) { return; }
382 static inline void sctp_sysctl_unregister(void) { return; }
383 static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
384 static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
385 #endif
386 
387 /* Size of Supported Address Parameter for 'x' address types. */
388 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
389 
390 #if IS_ENABLED(CONFIG_IPV6)
391 
392 void sctp_v6_pf_init(void);
393 void sctp_v6_pf_exit(void);
394 int sctp_v6_protosw_init(void);
395 void sctp_v6_protosw_exit(void);
396 int sctp_v6_add_protocol(void);
397 void sctp_v6_del_protocol(void);
398 
399 #else /* #ifdef defined(CONFIG_IPV6) */
400 
401 static inline void sctp_v6_pf_init(void) { return; }
402 static inline void sctp_v6_pf_exit(void) { return; }
403 static inline int sctp_v6_protosw_init(void) { return 0; }
404 static inline void sctp_v6_protosw_exit(void) { return; }
405 static inline int sctp_v6_add_protocol(void) { return 0; }
406 static inline void sctp_v6_del_protocol(void) { return; }
407 
408 #endif /* #if defined(CONFIG_IPV6) */
409 
410 
411 /* Map an association to an assoc_id. */
412 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
413 {
414 	return asoc ? asoc->assoc_id : 0;
415 }
416 
417 /* Look up the association by its id.  */
418 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
419 
420 int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
421 
422 /* A macro to walk a list of skbs.  */
423 #define sctp_skb_for_each(pos, head, tmp) \
424 	skb_queue_walk_safe(head, pos, tmp)
425 
426 /* A helper to append an entire skb list (list) to another (head). */
427 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
428 				      struct sk_buff_head *head)
429 {
430 	unsigned long flags;
431 
432 	sctp_spin_lock_irqsave(&head->lock, flags);
433 	sctp_spin_lock(&list->lock);
434 
435 	skb_queue_splice_tail_init(list, head);
436 
437 	sctp_spin_unlock(&list->lock);
438 	sctp_spin_unlock_irqrestore(&head->lock, flags);
439 }
440 
441 /**
442  *	sctp_list_dequeue - remove from the head of the queue
443  *	@list: list to dequeue from
444  *
445  *	Remove the head of the list. The head item is
446  *	returned or %NULL if the list is empty.
447  */
448 
449 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
450 {
451 	struct list_head *result = NULL;
452 
453 	if (list->next != list) {
454 		result = list->next;
455 		list->next = result->next;
456 		list->next->prev = list;
457 		INIT_LIST_HEAD(result);
458 	}
459 	return result;
460 }
461 
462 /* SCTP version of skb_set_owner_r.  We need this one because
463  * of the way we have to do receive buffer accounting on bundled
464  * chunks.
465  */
466 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
467 {
468 	struct sctp_ulpevent *event = sctp_skb2event(skb);
469 
470 	skb_orphan(skb);
471 	skb->sk = sk;
472 	skb->destructor = sctp_sock_rfree;
473 	atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
474 	/*
475 	 * This mimics the behavior of skb_set_owner_r
476 	 */
477 	sk->sk_forward_alloc -= event->rmem_len;
478 }
479 
480 /* Tests if the list has one and only one entry. */
481 static inline int sctp_list_single_entry(struct list_head *head)
482 {
483 	return (head->next != head) && (head->next == head->prev);
484 }
485 
486 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
487 static inline __s32 sctp_jitter(__u32 rto)
488 {
489 	static __u32 sctp_rand;
490 	__s32 ret;
491 
492 	/* Avoid divide by zero. */
493 	if (!rto)
494 		rto = 1;
495 
496 	sctp_rand += jiffies;
497 	sctp_rand ^= (sctp_rand << 12);
498 	sctp_rand ^= (sctp_rand >> 20);
499 
500 	/* Choose random number from 0 to rto, then move to -50% ~ +50%
501 	 * of rto.
502 	 */
503 	ret = sctp_rand % rto - (rto >> 1);
504 	return ret;
505 }
506 
507 /* Break down data chunks at this point.  */
508 static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
509 {
510 	struct sctp_sock *sp = sctp_sk(asoc->base.sk);
511 	int frag = pmtu;
512 
513 	frag -= sp->pf->af->net_header_len;
514 	frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
515 
516 	if (asoc->user_frag)
517 		frag = min_t(int, frag, asoc->user_frag);
518 
519 	frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
520 
521 	return frag;
522 }
523 
524 static inline void sctp_assoc_pending_pmtu(struct sock *sk, struct sctp_association *asoc)
525 {
526 
527 	sctp_assoc_sync_pmtu(sk, asoc);
528 	asoc->pmtu_pending = 0;
529 }
530 
531 /* Walk through a list of TLV parameters.  Don't trust the
532  * individual parameter lengths and instead depend on
533  * the chunk length to indicate when to stop.  Make sure
534  * there is room for a param header too.
535  */
536 #define sctp_walk_params(pos, chunk, member)\
537 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
538 
539 #define _sctp_walk_params(pos, chunk, end, member)\
540 for (pos.v = chunk->member;\
541      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
542      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
543      pos.v += WORD_ROUND(ntohs(pos.p->length)))
544 
545 #define sctp_walk_errors(err, chunk_hdr)\
546 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
547 
548 #define _sctp_walk_errors(err, chunk_hdr, end)\
549 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
550 	    sizeof(sctp_chunkhdr_t));\
551      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
552      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
553      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
554 
555 #define sctp_walk_fwdtsn(pos, chunk)\
556 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
557 
558 #define _sctp_walk_fwdtsn(pos, chunk, end)\
559 for (pos = chunk->subh.fwdtsn_hdr->skip;\
560      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
561      pos++)
562 
563 /* Round an int up to the next multiple of 4.  */
564 #define WORD_ROUND(s) (((s)+3)&~3)
565 
566 /* Make a new instance of type.  */
567 #define t_new(type, flags)	(type *)kzalloc(sizeof(type), flags)
568 
569 /* Compare two timevals.  */
570 #define tv_lt(s, t) \
571    (s.tv_sec < t.tv_sec || (s.tv_sec == t.tv_sec && s.tv_usec < t.tv_usec))
572 
573 /* Add tv1 to tv2. */
574 #define TIMEVAL_ADD(tv1, tv2) \
575 ({ \
576         suseconds_t usecs = (tv2).tv_usec + (tv1).tv_usec; \
577         time_t secs = (tv2).tv_sec + (tv1).tv_sec; \
578 \
579         if (usecs >= 1000000) { \
580                 usecs -= 1000000; \
581                 secs++; \
582         } \
583         (tv2).tv_sec = secs; \
584         (tv2).tv_usec = usecs; \
585 })
586 
587 /* External references. */
588 
589 extern struct proto sctp_prot;
590 extern struct proto sctpv6_prot;
591 void sctp_put_port(struct sock *sk);
592 
593 extern struct idr sctp_assocs_id;
594 extern spinlock_t sctp_assocs_id_lock;
595 
596 /* Static inline functions. */
597 
598 /* Convert from an IP version number to an Address Family symbol.  */
599 static inline int ipver2af(__u8 ipver)
600 {
601 	switch (ipver) {
602 	case 4:
603 	        return  AF_INET;
604 	case 6:
605 		return AF_INET6;
606 	default:
607 		return 0;
608 	}
609 }
610 
611 /* Convert from an address parameter type to an address family.  */
612 static inline int param_type2af(__be16 type)
613 {
614 	switch (type) {
615 	case SCTP_PARAM_IPV4_ADDRESS:
616 	        return  AF_INET;
617 	case SCTP_PARAM_IPV6_ADDRESS:
618 		return AF_INET6;
619 	default:
620 		return 0;
621 	}
622 }
623 
624 /* Perform some sanity checks. */
625 static inline int sctp_sanity_check(void)
626 {
627 	SCTP_ASSERT(sizeof(struct sctp_ulpevent) <=
628 		    sizeof(((struct sk_buff *)0)->cb),
629 		    "SCTP: ulpevent does not fit in skb!\n", return 0);
630 
631 	return 1;
632 }
633 
634 /* Warning: The following hash functions assume a power of two 'size'. */
635 /* This is the hash function for the SCTP port hash table. */
636 static inline int sctp_phashfn(struct net *net, __u16 lport)
637 {
638 	return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
639 }
640 
641 /* This is the hash function for the endpoint hash table. */
642 static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
643 {
644 	return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
645 }
646 
647 /* This is the hash function for the association hash table. */
648 static inline int sctp_assoc_hashfn(struct net *net, __u16 lport, __u16 rport)
649 {
650 	int h = (lport << 16) + rport + net_hash_mix(net);
651 	h ^= h>>8;
652 	return h & (sctp_assoc_hashsize - 1);
653 }
654 
655 /* This is the hash function for the association hash table.  This is
656  * not used yet, but could be used as a better hash function when
657  * we have a vtag.
658  */
659 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
660 {
661 	int h = (lport << 16) + rport;
662 	h ^= vtag;
663 	return h & (sctp_assoc_hashsize - 1);
664 }
665 
666 #define sctp_for_each_hentry(epb, node, head) \
667 	hlist_for_each_entry(epb, node, head, node)
668 
669 /* Is a socket of this style? */
670 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
671 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
672 {
673 	return sctp_sk(sk)->type == style;
674 }
675 
676 /* Is the association in this state? */
677 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
678 static inline int __sctp_state(const struct sctp_association *asoc,
679 			       sctp_state_t state)
680 {
681 	return asoc->state == state;
682 }
683 
684 /* Is the socket in this state? */
685 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
686 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
687 {
688 	return sk->sk_state == state;
689 }
690 
691 /* Map v4-mapped v6 address back to v4 address */
692 static inline void sctp_v6_map_v4(union sctp_addr *addr)
693 {
694 	addr->v4.sin_family = AF_INET;
695 	addr->v4.sin_port = addr->v6.sin6_port;
696 	addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
697 }
698 
699 /* Map v4 address to v4-mapped v6 address */
700 static inline void sctp_v4_map_v6(union sctp_addr *addr)
701 {
702 	addr->v6.sin6_family = AF_INET6;
703 	addr->v6.sin6_port = addr->v4.sin_port;
704 	addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
705 	addr->v6.sin6_addr.s6_addr32[0] = 0;
706 	addr->v6.sin6_addr.s6_addr32[1] = 0;
707 	addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
708 }
709 
710 /* The cookie is always 0 since this is how it's used in the
711  * pmtu code.
712  */
713 static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
714 {
715 	if (t->dst && !dst_check(t->dst, 0)) {
716 		dst_release(t->dst);
717 		t->dst = NULL;
718 	}
719 
720 	return t->dst;
721 }
722 
723 #endif /* __net_sctp_h__ */
724