aboutsummaryrefslogtreecommitdiffstats
path: root/include/net/sctp/sctp.h
blob: c713bd62428f6d01e85e5f3b29ce1d42461f9d79 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
/* SCTP kernel implementation
 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2001-2003 Intel Corp.
 *
 * This file is part of the SCTP kernel implementation
 *
 * The base lksctp header.
 *
 * This SCTP implementation is free software;
 * you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This SCTP implementation is distributed in the hope that it
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *                 ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU CC; see the file COPYING.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <linux-sctp@vger.kernel.org>
 *
 * Written or modified by:
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Xingang Guo           <xingang.guo@intel.com>
 *    Jon Grimm             <jgrimm@us.ibm.com>
 *    Daisy Chang           <daisyc@us.ibm.com>
 *    Sridhar Samudrala     <sri@us.ibm.com>
 *    Ardelle Fan           <ardelle.fan@intel.com>
 *    Ryan Layer            <rmlayer@us.ibm.com>
 *    Kevin Gao             <kevin.gao@intel.com> 
 */

#ifndef __net_sctp_h__
#define __net_sctp_h__

/* Header Strategy.
 *    Start getting some control over the header file depencies:
 *       includes
 *       constants
 *       structs
 *       prototypes
 *       macros, externs, and inlines
 *
 *   Move test_frame specific items out of the kernel headers
 *   and into the test frame headers.   This is not perfect in any sense
 *   and will continue to evolve.
 */

#include <linux/types.h>
#include <linux/slab.h>
#include <linux/in.h>
#include <linux/tty.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/jiffies.h>
#include <linux/idr.h>

#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
#include <net/ip6_route.h>
#endif

#include <linux/uaccess.h>
#include <asm/page.h>
#include <net/sock.h>
#include <net/snmp.h>
#include <net/sctp/structs.h>
#include <net/sctp/constants.h>

#ifdef CONFIG_IP_SCTP_MODULE
#define SCTP_PROTOSW_FLAG 0
#else /* static! */
#define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
#endif

/* Round an int up to the next multiple of 4.  */
#define SCTP_PAD4(s) (((s)+3)&~3)
/* Truncate to the previous multiple of 4.  */
#define SCTP_TRUNC4(s) ((s)&~3)

/*
 * Function declarations.
 */

/*
 * sctp/protocol.c
 */
int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *addr,
			      enum sctp_scope, gfp_t gfp, int flags);
struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
int sctp_register_pf(struct sctp_pf *, sa_family_t);
void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);

/*
 * sctp/socket.c
 */
int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr,
		      int addr_len, int flags);
int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
int sctp_inet_listen(struct socket *sock, int backlog);
void sctp_write_space(struct sock *sk);
void sctp_data_ready(struct sock *sk);
unsigned int sctp_poll(struct file *file, struct socket *sock,
		poll_table *wait);
void sctp_sock_rfree(struct sk_buff *skb);
void sctp_copy_sock(struct sock *newsk, struct sock *sk,
		    struct sctp_association *asoc);
extern struct percpu_counter sctp_sockets_allocated;
int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);

int sctp_transport_walk_start(struct rhashtable_iter *iter);
void sctp_transport_walk_stop(struct rhashtable_iter *iter);
struct sctp_transport *sctp_transport_get_next(struct net *net,
			struct rhashtable_iter *iter);
struct sctp_transport *sctp_transport_get_idx(struct net *net,
			struct rhashtable_iter *iter, int pos);
int sctp_transport_lookup_process(int (*cb)(struct sctp_transport *, void *),
				  struct net *net,
				  const union sctp_addr *laddr,
				  const union sctp_addr *paddr, void *p);
int sctp_for_each_transport(int (*cb)(struct sctp_transport *, void *),
			    int (*cb_done)(struct sctp_transport *, void *),
			    struct net *net, int *pos, void *p);
int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p);
int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc,
		       struct sctp_info *info);

/*
 * sctp/primitive.c
 */
int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
			  void *arg);

/*
 * sctp/input.c
 */
int sctp_rcv(struct sk_buff *skb);
void sctp_v4_err(struct sk_buff *skb, u32 info);
void sctp_hash_endpoint(struct sctp_endpoint *);
void sctp_unhash_endpoint(struct sctp_endpoint *);
struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
			     struct sctphdr *, struct sctp_association **,
			     struct sctp_transport **);
void sctp_err_finish(struct sock *, struct sctp_transport *);
void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
			   struct sctp_transport *t, __u32 pmtu);
void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
			struct sk_buff *);
void sctp_icmp_proto_unreachable(struct sock *sk,
				 struct sctp_association *asoc,
				 struct sctp_transport *t);
void sctp_backlog_migrate(struct sctp_association *assoc,
			  struct sock *oldsk, struct sock *newsk);
int sctp_transport_hashtable_init(void);
void sctp_transport_hashtable_destroy(void);
int sctp_hash_transport(struct sctp_transport *t);
void sctp_unhash_transport(struct sctp_transport *t);
struct sctp_transport *sctp_addrs_lookup_transport(
				struct net *net,
				const union sctp_addr *laddr,
				const union sctp_addr *paddr);
struct sctp_transport *sctp_epaddr_lookup_transport(
				const struct sctp_endpoint *ep,
				const union sctp_addr *paddr);

/*
 * sctp/proc.c
 */
int sctp_snmp_proc_init(struct net *net);
void sctp_snmp_proc_exit(struct net *net);
int sctp_eps_proc_init(struct net *net);
void sctp_eps_proc_exit(struct net *net);
int sctp_assocs_proc_init(struct net *net);
void sctp_assocs_proc_exit(struct net *net);
int sctp_remaddr_proc_init(struct net *net);
void sctp_remaddr_proc_exit(struct net *net);

/*
 * sctp/offload.c
 */
int sctp_offload_init(void);

/*
 * sctp/stream.c
 */
int sctp_send_reset_streams(struct sctp_association *asoc,
			    struct sctp_reset_streams *params);
int sctp_send_reset_assoc(struct sctp_association *asoc);
int sctp_send_add_streams(struct sctp_association *asoc,
			  struct sctp_add_streams *params);

/*
 * Module global variables
 */

 /*
  * sctp/protocol.c
  */
extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
extern long sysctl_sctp_mem[3];
extern int sysctl_sctp_rmem[3];
extern int sysctl_sctp_wmem[3];

/*
 *  Section:  Macros, externs, and inlines
 */

/* SCTP SNMP MIB stats handlers */
#define SCTP_INC_STATS(net, field)	SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
#define __SCTP_INC_STATS(net, field)	__SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
#define SCTP_DEC_STATS(net, field)	SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)

/* sctp mib definitions */
enum {
	SCTP_MIB_NUM = 0,
	SCTP_MIB_CURRESTAB,			/* CurrEstab */
	SCTP_MIB_ACTIVEESTABS,			/* ActiveEstabs */
	SCTP_MIB_PASSIVEESTABS,			/* PassiveEstabs */
	SCTP_MIB_ABORTEDS,			/* Aborteds */
	SCTP_MIB_SHUTDOWNS,			/* Shutdowns */
	SCTP_MIB_OUTOFBLUES,			/* OutOfBlues */
	SCTP_MIB_CHECKSUMERRORS,		/* ChecksumErrors */
	SCTP_MIB_OUTCTRLCHUNKS,			/* OutCtrlChunks */
	SCTP_MIB_OUTORDERCHUNKS,		/* OutOrderChunks */
	SCTP_MIB_OUTUNORDERCHUNKS,		/* OutUnorderChunks */
	SCTP_MIB_INCTRLCHUNKS,			/* InCtrlChunks */
	SCTP_MIB_INORDERCHUNKS,			/* InOrderChunks */
	SCTP_MIB_INUNORDERCHUNKS,		/* InUnorderChunks */
	SCTP_MIB_FRAGUSRMSGS,			/* FragUsrMsgs */
	SCTP_MIB_REASMUSRMSGS,			/* ReasmUsrMsgs */
	SCTP_MIB_OUTSCTPPACKS,			/* OutSCTPPacks */
	SCTP_MIB_INSCTPPACKS,			/* InSCTPPacks */
	SCTP_MIB_T1_INIT_EXPIREDS,
	SCTP_MIB_T1_COOKIE_EXPIREDS,
	SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
	SCTP_MIB_T3_RTX_EXPIREDS,
	SCTP_MIB_T4_RTO_EXPIREDS,
	SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
	SCTP_MIB_DELAY_SACK_EXPIREDS,
	SCTP_MIB_AUTOCLOSE_EXPIREDS,
	SCTP_MIB_T1_RETRANSMITS,
	SCTP_MIB_T3_RETRANSMITS,
	SCTP_MIB_PMTUD_RETRANSMITS,
	SCTP_MIB_FAST_RETRANSMITS,
	SCTP_MIB_IN_PKT_SOFTIRQ,
	SCTP_MIB_IN_PKT_BACKLOG,
	SCTP_MIB_IN_PKT_DISCARDS,
	SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
	__SCTP_MIB_MAX
};

#define SCTP_MIB_MAX    __SCTP_MIB_MAX
struct sctp_mib {
        unsigned long   mibs[SCTP_MIB_MAX];
};

/* helper function to track stats about max rto and related transport */
static inline void sctp_max_rto(struct sctp_association *asoc,
				struct sctp_transport *trans)
{
	if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
		asoc->stats.max_obs_rto = trans->rto;
		memset(&asoc->stats.obs_rto_ipaddr, 0,
			sizeof(struct sockaddr_storage));
		memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
			trans->af_specific->sockaddr_len);
	}
}

/*
 * Macros for keeping a global reference of object allocations.
 */
#ifdef CONFIG_SCTP_DBG_OBJCNT

extern atomic_t sctp_dbg_objcnt_sock;
extern atomic_t sctp_dbg_objcnt_ep;
extern atomic_t sctp_dbg_objcnt_assoc;
extern atomic_t sctp_dbg_objcnt_transport;
extern atomic_t sctp_dbg_objcnt_chunk;
extern atomic_t sctp_dbg_objcnt_bind_addr;
extern atomic_t sctp_dbg_objcnt_bind_bucket;
extern atomic_t sctp_dbg_objcnt_addr;
extern atomic_t sctp_dbg_objcnt_datamsg;
extern atomic_t sctp_dbg_objcnt_keys;

/* Macros to atomically increment/decrement objcnt counters.  */
#define SCTP_DBG_OBJCNT_INC(name) \
atomic_inc(&sctp_dbg_objcnt_## name)
#define SCTP_DBG_OBJCNT_DEC(name) \
atomic_dec(&sctp_dbg_objcnt_## name)
#define SCTP_DBG_OBJCNT(name) \
atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)

/* Macro to help create new entries in in the global array of
 * objcnt counters.
 */
#define SCTP_DBG_OBJCNT_ENTRY(name) \
{.label= #name, .counter= &sctp_dbg_objcnt_## name}

void sctp_dbg_objcnt_init(struct net *);
void sctp_dbg_objcnt_exit(struct net *);

#else

#define SCTP_DBG_OBJCNT_INC(name)
#define SCTP_DBG_OBJCNT_DEC(name)

static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
static inline void sctp_dbg_objcnt_exit(struct net *net) { return; }

#endif /* CONFIG_SCTP_DBG_OBJCOUNT */

#if defined CONFIG_SYSCTL
void sctp_sysctl_register(void);
void sctp_sysctl_unregister(void);
int sctp_sysctl_net_register(struct net *net);
void sctp_sysctl_net_unregister(struct net *net);
#else
static inline void sctp_sysctl_register(void) { return; }
static inline void sctp_sysctl_unregister(void) { return; }
static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
#endif

/* Size of Supported Address Parameter for 'x' address types. */
#define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))

#if IS_ENABLED(CONFIG_IPV6)

void sctp_v6_pf_init(void);
void sctp_v6_pf_exit(void);
int sctp_v6_protosw_init(void);
void sctp_v6_protosw_exit(void);
int sctp_v6_add_protocol(void);
void sctp_v6_del_protocol(void);

#else /* #ifdef defined(CONFIG_IPV6) */

static inline void sctp_v6_pf_init(void) { return; }
static inline void sctp_v6_pf_exit(void) { return; }
static inline int sctp_v6_protosw_init(void) { return 0; }
static inline void sctp_v6_protosw_exit(void) { return; }
static inline int sctp_v6_add_protocol(void) { return 0; }
static inline void sctp_v6_del_protocol(void) { return; }

#endif /* #if defined(CONFIG_IPV6) */


/* Map an association to an assoc_id. */
static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
{
	return asoc ? asoc->assoc_id : 0;
}

static inline enum sctp_sstat_state
sctp_assoc_to_state(const struct sctp_association *asoc)
{
	/* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
	 * got rid of it in kernel space. Therefore SCTP_CLOSED et al
	 * start at =1 in user space, but actually as =0 in kernel space.
	 * Now that we can not break user space and SCTP_EMPTY is exposed
	 * there, we need to fix it up with an ugly offset not to break
	 * applications. :(
	 */
	return asoc->state + 1;
}

/* Look up the association by its id.  */
struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);

int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);

/* A macro to walk a list of skbs.  */
#define sctp_skb_for_each(pos, head, tmp) \
	skb_queue_walk_safe(head, pos, tmp)

/**
 *	sctp_list_dequeue - remove from the head of the queue
 *	@list: list to dequeue from
 *
 *	Remove the head of the list. The head item is
 *	returned or %NULL if the list is empty.
 */

static inline struct list_head *sctp_list_dequeue(struct list_head *list)
{
	struct list_head *result = NULL;

	if (!list_empty(list)) {
		result = list->next;
		list_del_init(result);
	}
	return result;
}

/* SCTP version of skb_set_owner_r.  We need this one because
 * of the way we have to do receive buffer accounting on bundled
 * chunks.
 */
static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
{
	struct sctp_ulpevent *event = sctp_skb2event(skb);

	skb_orphan(skb);
	skb->sk = sk;
	skb->destructor = sctp_sock_rfree;
	atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
	/*
	 * This mimics the behavior of skb_set_owner_r
	 */
	sk->sk_forward_alloc -= event->rmem_len;
}

/* Tests if the list has one and only one entry. */
static inline int sctp_list_single_entry(struct list_head *head)
{
	return (head->next != head) && (head->next == head->prev);
}

/* Break down data chunks at this point.  */
static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
{
	struct sctp_sock *sp = sctp_sk(asoc->base.sk);
	int frag = pmtu;

	frag -= sp->pf->af->net_header_len;
	frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);

	if (asoc->user_frag)
		frag = min_t(int, frag, asoc->user_frag);

	frag = SCTP_TRUNC4(min_t(int, frag, SCTP_MAX_CHUNK_LEN -
					    sizeof(struct sctp_data_chunk)));

	return frag;
}

static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc)
{
	sctp_assoc_sync_pmtu(asoc);
	asoc->pmtu_pending = 0;
}

static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
{
	return !list_empty(&chunk->list);
}

/* Walk through a list of TLV parameters.  Don't trust the
 * individual parameter lengths and instead depend on
 * the chunk length to indicate when to stop.  Make sure
 * there is room for a param header too.
 */
#define sctp_walk_params(pos, chunk, member)\
_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)

#define _sctp_walk_params(pos, chunk, end, member)\
for (pos.v = chunk->member;\
     (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\
      (void *)chunk + end) &&\
     pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
     ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\
     pos.v += SCTP_PAD4(ntohs(pos.p->length)))

#define sctp_walk_errors(err, chunk_hdr)\
_sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))

#define _sctp_walk_errors(err, chunk_hdr, end)\
for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \
	    sizeof(struct sctp_chunkhdr));\
     ((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\
      (void *)chunk_hdr + end) &&\
     (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
     ntohs(err->length) >= sizeof(struct sctp_errhdr); \
     err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length))))

#define sctp_walk_fwdtsn(pos, chunk)\
_sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))

#define _sctp_walk_fwdtsn(pos, chunk, end)\
for (pos = chunk->subh.fwdtsn_hdr->skip;\
     (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
     pos++)

/* External references. */

extern struct proto sctp_prot;
extern struct proto sctpv6_prot;
void sctp_put_port(struct sock *sk);

extern struct idr sctp_assocs_id;
extern spinlock_t sctp_assocs_id_lock;

/* Static inline functions. */

/* Convert from an IP version number to an Address Family symbol.  */
static inline int ipver2af(__u8 ipver)
{
	switch (ipver) {
	case 4:
	        return  AF_INET;
	case 6:
		return AF_INET6;
	default:
		return 0;
	}
}

/* Convert from an address parameter type to an address family.  */
static inline int param_type2af(__be16 type)
{
	switch (type) {
	case SCTP_PARAM_IPV4_ADDRESS:
	        return  AF_INET;
	case SCTP_PARAM_IPV6_ADDRESS:
		return AF_INET6;
	default:
		return 0;
	}
}

/* Warning: The following hash functions assume a power of two 'size'. */
/* This is the hash function for the SCTP port hash table. */
static inline int sctp_phashfn(struct net *net, __u16 lport)
{
	return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
}

/* This is the hash function for the endpoint hash table. */
static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
{
	return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
}

#define sctp_for_each_hentry(epb, head) \
	hlist_for_each_entry(epb, head, node)

/* Is a socket of this style? */
#define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
static inline int __sctp_style(const struct sock *sk,
			       enum sctp_socket_type style)
{
	return sctp_sk(sk)->type == style;
}

/* Is the association in this state? */
#define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
static inline int __sctp_state(const struct sctp_association *asoc,
			       enum sctp_state state)
{
	return asoc->state == state;
}

/* Is the socket in this state? */
#define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
static inline int __sctp_sstate(const struct sock *sk,
				enum sctp_sock_state state)
{
	return sk->sk_state == state;
}

/* Map v4-mapped v6 address back to v4 address */
static inline void sctp_v6_map_v4(union sctp_addr *addr)
{
	addr->v4.sin_family = AF_INET;
	addr->v4.sin_port = addr->v6.sin6_port;
	addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
}

/* Map v4 address to v4-mapped v6 address */
static inline void sctp_v4_map_v6(union sctp_addr *addr)
{
	__be16 port;

	port = addr->v4.sin_port;
	addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
	addr->v6.sin6_port = port;
	addr->v6.sin6_family = AF_INET6;
	addr->v6.sin6_flowinfo = 0;
	addr->v6.sin6_scope_id = 0;
	addr->v6.sin6_addr.s6_addr32[0] = 0;
	addr->v6.sin6_addr.s6_addr32[1] = 0;
	addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
}

/* The cookie is always 0 since this is how it's used in the
 * pmtu code.
 */
static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
{
	if (t->dst && !dst_check(t->dst, t->dst_cookie))
		sctp_transport_dst_release(t);

	return t->dst;
}

static inline bool sctp_transport_pmtu_check(struct sctp_transport *t)
{
	__u32 pmtu = max_t(size_t, SCTP_TRUNC4(dst_mtu(t->dst)),
			   SCTP_DEFAULT_MINSEGMENT);

	if (t->pathmtu == pmtu)
		return true;

	t->pathmtu = pmtu;

	return false;
}

#endif /* __net_sctp_h__ */