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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, see
25 * <http://www.gnu.org/licenses/>.
26 *
27 * Please send any bug reports or fixes you make to the
28 * email address(es):
29 * lksctp developers <linux-sctp@vger.kernel.org>
30 *
31 * Written or modified by:
32 * La Monte H.P. Yarroll <piggy@acm.org>
33 * Xingang Guo <xingang.guo@intel.com>
34 * Jon Grimm <jgrimm@us.ibm.com>
35 * Daisy Chang <daisyc@us.ibm.com>
36 * Sridhar Samudrala <sri@us.ibm.com>
37 * Ardelle Fan <ardelle.fan@intel.com>
38 * Ryan Layer <rmlayer@us.ibm.com>
39 * Kevin Gao <kevin.gao@intel.com>
40 */
41
42#ifndef __net_sctp_h__
43#define __net_sctp_h__
44
45/* Header Strategy.
46 * Start getting some control over the header file depencies:
47 * includes
48 * constants
49 * structs
50 * prototypes
51 * macros, externs, and inlines
52 *
53 * Move test_frame specific items out of the kernel headers
54 * and into the test frame headers. This is not perfect in any sense
55 * and will continue to evolve.
56 */
57
58#include <linux/types.h>
59#include <linux/slab.h>
60#include <linux/in.h>
61#include <linux/tty.h>
62#include <linux/proc_fs.h>
63#include <linux/spinlock.h>
64#include <linux/jiffies.h>
65#include <linux/idr.h>
66
67#if IS_ENABLED(CONFIG_IPV6)
68#include <net/ipv6.h>
69#include <net/ip6_route.h>
70#endif
71
72#include <asm/uaccess.h>
73#include <asm/page.h>
74#include <net/sock.h>
75#include <net/snmp.h>
76#include <net/sctp/structs.h>
77#include <net/sctp/constants.h>
78
79#ifdef CONFIG_IP_SCTP_MODULE
80#define SCTP_PROTOSW_FLAG 0
81#else /* static! */
82#define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
83#endif
84
85/* Round an int up to the next multiple of 4. */
86#define WORD_ROUND(s) (((s)+3)&~3)
87/* Truncate to the previous multiple of 4. */
88#define WORD_TRUNC(s) ((s)&~3)
89
90/*
91 * Function declarations.
92 */
93
94/*
95 * sctp/protocol.c
96 */
97int sctp_copy_local_addr_list(struct net *, struct sctp_bind_addr *,
98 sctp_scope_t, gfp_t gfp, int flags);
99struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
100int sctp_register_pf(struct sctp_pf *, sa_family_t);
101void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
102
103/*
104 * sctp/socket.c
105 */
106int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
107int sctp_inet_listen(struct socket *sock, int backlog);
108void sctp_write_space(struct sock *sk);
109void sctp_data_ready(struct sock *sk);
110unsigned int sctp_poll(struct file *file, struct socket *sock,
111 poll_table *wait);
112void sctp_sock_rfree(struct sk_buff *skb);
113void sctp_copy_sock(struct sock *newsk, struct sock *sk,
114 struct sctp_association *asoc);
115extern struct percpu_counter sctp_sockets_allocated;
116int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
117struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);
118
119/*
120 * sctp/primitive.c
121 */
122int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
123int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
124int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
125int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
126int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
127int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
128
129/*
130 * sctp/input.c
131 */
132int sctp_rcv(struct sk_buff *skb);
133void sctp_v4_err(struct sk_buff *skb, u32 info);
134void sctp_hash_endpoint(struct sctp_endpoint *);
135void sctp_unhash_endpoint(struct sctp_endpoint *);
136struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
137 struct sctphdr *, struct sctp_association **,
138 struct sctp_transport **);
139void sctp_err_finish(struct sock *, struct sctp_association *);
140void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
141 struct sctp_transport *t, __u32 pmtu);
142void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
143 struct sk_buff *);
144void sctp_icmp_proto_unreachable(struct sock *sk,
145 struct sctp_association *asoc,
146 struct sctp_transport *t);
147void sctp_backlog_migrate(struct sctp_association *assoc,
148 struct sock *oldsk, struct sock *newsk);
149int sctp_transport_hashtable_init(void);
150void sctp_transport_hashtable_destroy(void);
151void sctp_hash_transport(struct sctp_transport *t);
152void sctp_unhash_transport(struct sctp_transport *t);
153struct sctp_transport *sctp_addrs_lookup_transport(
154 struct net *net,
155 const union sctp_addr *laddr,
156 const union sctp_addr *paddr);
157struct sctp_transport *sctp_epaddr_lookup_transport(
158 const struct sctp_endpoint *ep,
159 const union sctp_addr *paddr);
160
161/*
162 * sctp/proc.c
163 */
164int sctp_snmp_proc_init(struct net *net);
165void sctp_snmp_proc_exit(struct net *net);
166int sctp_eps_proc_init(struct net *net);
167void sctp_eps_proc_exit(struct net *net);
168int sctp_assocs_proc_init(struct net *net);
169void sctp_assocs_proc_exit(struct net *net);
170int sctp_remaddr_proc_init(struct net *net);
171void sctp_remaddr_proc_exit(struct net *net);
172
173
174/*
175 * Module global variables
176 */
177
178 /*
179 * sctp/protocol.c
180 */
181extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
182extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
183extern long sysctl_sctp_mem[3];
184extern int sysctl_sctp_rmem[3];
185extern int sysctl_sctp_wmem[3];
186
187/*
188 * Section: Macros, externs, and inlines
189 */
190
191/* SCTP SNMP MIB stats handlers */
192#define SCTP_INC_STATS(net, field) SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
193#define SCTP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->sctp.sctp_statistics, field)
194#define SCTP_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->sctp.sctp_statistics, field)
195#define SCTP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
196
197/* sctp mib definitions */
198enum {
199 SCTP_MIB_NUM = 0,
200 SCTP_MIB_CURRESTAB, /* CurrEstab */
201 SCTP_MIB_ACTIVEESTABS, /* ActiveEstabs */
202 SCTP_MIB_PASSIVEESTABS, /* PassiveEstabs */
203 SCTP_MIB_ABORTEDS, /* Aborteds */
204 SCTP_MIB_SHUTDOWNS, /* Shutdowns */
205 SCTP_MIB_OUTOFBLUES, /* OutOfBlues */
206 SCTP_MIB_CHECKSUMERRORS, /* ChecksumErrors */
207 SCTP_MIB_OUTCTRLCHUNKS, /* OutCtrlChunks */
208 SCTP_MIB_OUTORDERCHUNKS, /* OutOrderChunks */
209 SCTP_MIB_OUTUNORDERCHUNKS, /* OutUnorderChunks */
210 SCTP_MIB_INCTRLCHUNKS, /* InCtrlChunks */
211 SCTP_MIB_INORDERCHUNKS, /* InOrderChunks */
212 SCTP_MIB_INUNORDERCHUNKS, /* InUnorderChunks */
213 SCTP_MIB_FRAGUSRMSGS, /* FragUsrMsgs */
214 SCTP_MIB_REASMUSRMSGS, /* ReasmUsrMsgs */
215 SCTP_MIB_OUTSCTPPACKS, /* OutSCTPPacks */
216 SCTP_MIB_INSCTPPACKS, /* InSCTPPacks */
217 SCTP_MIB_T1_INIT_EXPIREDS,
218 SCTP_MIB_T1_COOKIE_EXPIREDS,
219 SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
220 SCTP_MIB_T3_RTX_EXPIREDS,
221 SCTP_MIB_T4_RTO_EXPIREDS,
222 SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
223 SCTP_MIB_DELAY_SACK_EXPIREDS,
224 SCTP_MIB_AUTOCLOSE_EXPIREDS,
225 SCTP_MIB_T1_RETRANSMITS,
226 SCTP_MIB_T3_RETRANSMITS,
227 SCTP_MIB_PMTUD_RETRANSMITS,
228 SCTP_MIB_FAST_RETRANSMITS,
229 SCTP_MIB_IN_PKT_SOFTIRQ,
230 SCTP_MIB_IN_PKT_BACKLOG,
231 SCTP_MIB_IN_PKT_DISCARDS,
232 SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
233 __SCTP_MIB_MAX
234};
235
236#define SCTP_MIB_MAX __SCTP_MIB_MAX
237struct sctp_mib {
238 unsigned long mibs[SCTP_MIB_MAX];
239};
240
241/* helper function to track stats about max rto and related transport */
242static inline void sctp_max_rto(struct sctp_association *asoc,
243 struct sctp_transport *trans)
244{
245 if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
246 asoc->stats.max_obs_rto = trans->rto;
247 memset(&asoc->stats.obs_rto_ipaddr, 0,
248 sizeof(struct sockaddr_storage));
249 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
250 trans->af_specific->sockaddr_len);
251 }
252}
253
254/*
255 * Macros for keeping a global reference of object allocations.
256 */
257#ifdef CONFIG_SCTP_DBG_OBJCNT
258
259extern atomic_t sctp_dbg_objcnt_sock;
260extern atomic_t sctp_dbg_objcnt_ep;
261extern atomic_t sctp_dbg_objcnt_assoc;
262extern atomic_t sctp_dbg_objcnt_transport;
263extern atomic_t sctp_dbg_objcnt_chunk;
264extern atomic_t sctp_dbg_objcnt_bind_addr;
265extern atomic_t sctp_dbg_objcnt_bind_bucket;
266extern atomic_t sctp_dbg_objcnt_addr;
267extern atomic_t sctp_dbg_objcnt_ssnmap;
268extern atomic_t sctp_dbg_objcnt_datamsg;
269extern atomic_t sctp_dbg_objcnt_keys;
270
271/* Macros to atomically increment/decrement objcnt counters. */
272#define SCTP_DBG_OBJCNT_INC(name) \
273atomic_inc(&sctp_dbg_objcnt_## name)
274#define SCTP_DBG_OBJCNT_DEC(name) \
275atomic_dec(&sctp_dbg_objcnt_## name)
276#define SCTP_DBG_OBJCNT(name) \
277atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
278
279/* Macro to help create new entries in in the global array of
280 * objcnt counters.
281 */
282#define SCTP_DBG_OBJCNT_ENTRY(name) \
283{.label= #name, .counter= &sctp_dbg_objcnt_## name}
284
285void sctp_dbg_objcnt_init(struct net *);
286void sctp_dbg_objcnt_exit(struct net *);
287
288#else
289
290#define SCTP_DBG_OBJCNT_INC(name)
291#define SCTP_DBG_OBJCNT_DEC(name)
292
293static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
294static inline void sctp_dbg_objcnt_exit(struct net *net) { return; }
295
296#endif /* CONFIG_SCTP_DBG_OBJCOUNT */
297
298#if defined CONFIG_SYSCTL
299void sctp_sysctl_register(void);
300void sctp_sysctl_unregister(void);
301int sctp_sysctl_net_register(struct net *net);
302void sctp_sysctl_net_unregister(struct net *net);
303#else
304static inline void sctp_sysctl_register(void) { return; }
305static inline void sctp_sysctl_unregister(void) { return; }
306static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
307static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
308#endif
309
310/* Size of Supported Address Parameter for 'x' address types. */
311#define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
312
313#if IS_ENABLED(CONFIG_IPV6)
314
315void sctp_v6_pf_init(void);
316void sctp_v6_pf_exit(void);
317int sctp_v6_protosw_init(void);
318void sctp_v6_protosw_exit(void);
319int sctp_v6_add_protocol(void);
320void sctp_v6_del_protocol(void);
321
322#else /* #ifdef defined(CONFIG_IPV6) */
323
324static inline void sctp_v6_pf_init(void) { return; }
325static inline void sctp_v6_pf_exit(void) { return; }
326static inline int sctp_v6_protosw_init(void) { return 0; }
327static inline void sctp_v6_protosw_exit(void) { return; }
328static inline int sctp_v6_add_protocol(void) { return 0; }
329static inline void sctp_v6_del_protocol(void) { return; }
330
331#endif /* #if defined(CONFIG_IPV6) */
332
333
334/* Map an association to an assoc_id. */
335static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
336{
337 return asoc ? asoc->assoc_id : 0;
338}
339
340static inline enum sctp_sstat_state
341sctp_assoc_to_state(const struct sctp_association *asoc)
342{
343 /* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
344 * got rid of it in kernel space. Therefore SCTP_CLOSED et al
345 * start at =1 in user space, but actually as =0 in kernel space.
346 * Now that we can not break user space and SCTP_EMPTY is exposed
347 * there, we need to fix it up with an ugly offset not to break
348 * applications. :(
349 */
350 return asoc->state + 1;
351}
352
353/* Look up the association by its id. */
354struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
355
356int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
357
358/* A macro to walk a list of skbs. */
359#define sctp_skb_for_each(pos, head, tmp) \
360 skb_queue_walk_safe(head, pos, tmp)
361
362/* A helper to append an entire skb list (list) to another (head). */
363static inline void sctp_skb_list_tail(struct sk_buff_head *list,
364 struct sk_buff_head *head)
365{
366 unsigned long flags;
367
368 spin_lock_irqsave(&head->lock, flags);
369 spin_lock(&list->lock);
370
371 skb_queue_splice_tail_init(list, head);
372
373 spin_unlock(&list->lock);
374 spin_unlock_irqrestore(&head->lock, flags);
375}
376
377/**
378 * sctp_list_dequeue - remove from the head of the queue
379 * @list: list to dequeue from
380 *
381 * Remove the head of the list. The head item is
382 * returned or %NULL if the list is empty.
383 */
384
385static inline struct list_head *sctp_list_dequeue(struct list_head *list)
386{
387 struct list_head *result = NULL;
388
389 if (!list_empty(list)) {
390 result = list->next;
391 list_del_init(result);
392 }
393 return result;
394}
395
396/* SCTP version of skb_set_owner_r. We need this one because
397 * of the way we have to do receive buffer accounting on bundled
398 * chunks.
399 */
400static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
401{
402 struct sctp_ulpevent *event = sctp_skb2event(skb);
403
404 skb_orphan(skb);
405 skb->sk = sk;
406 skb->destructor = sctp_sock_rfree;
407 atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
408 /*
409 * This mimics the behavior of skb_set_owner_r
410 */
411 sk->sk_forward_alloc -= event->rmem_len;
412}
413
414/* Tests if the list has one and only one entry. */
415static inline int sctp_list_single_entry(struct list_head *head)
416{
417 return (head->next != head) && (head->next == head->prev);
418}
419
420/* Break down data chunks at this point. */
421static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
422{
423 struct sctp_sock *sp = sctp_sk(asoc->base.sk);
424 int frag = pmtu;
425
426 frag -= sp->pf->af->net_header_len;
427 frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
428
429 if (asoc->user_frag)
430 frag = min_t(int, frag, asoc->user_frag);
431
432 frag = WORD_TRUNC(min_t(int, frag, SCTP_MAX_CHUNK_LEN));
433
434 return frag;
435}
436
437static inline void sctp_assoc_pending_pmtu(struct sock *sk, struct sctp_association *asoc)
438{
439
440 sctp_assoc_sync_pmtu(sk, asoc);
441 asoc->pmtu_pending = 0;
442}
443
444static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
445{
446 return !list_empty(&chunk->list);
447}
448
449/* Walk through a list of TLV parameters. Don't trust the
450 * individual parameter lengths and instead depend on
451 * the chunk length to indicate when to stop. Make sure
452 * there is room for a param header too.
453 */
454#define sctp_walk_params(pos, chunk, member)\
455_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
456
457#define _sctp_walk_params(pos, chunk, end, member)\
458for (pos.v = chunk->member;\
459 pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
460 ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
461 pos.v += WORD_ROUND(ntohs(pos.p->length)))
462
463#define sctp_walk_errors(err, chunk_hdr)\
464_sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
465
466#define _sctp_walk_errors(err, chunk_hdr, end)\
467for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
468 sizeof(sctp_chunkhdr_t));\
469 (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
470 ntohs(err->length) >= sizeof(sctp_errhdr_t); \
471 err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
472
473#define sctp_walk_fwdtsn(pos, chunk)\
474_sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
475
476#define _sctp_walk_fwdtsn(pos, chunk, end)\
477for (pos = chunk->subh.fwdtsn_hdr->skip;\
478 (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
479 pos++)
480
481/* External references. */
482
483extern struct proto sctp_prot;
484extern struct proto sctpv6_prot;
485void sctp_put_port(struct sock *sk);
486
487extern struct idr sctp_assocs_id;
488extern spinlock_t sctp_assocs_id_lock;
489
490/* Static inline functions. */
491
492/* Convert from an IP version number to an Address Family symbol. */
493static inline int ipver2af(__u8 ipver)
494{
495 switch (ipver) {
496 case 4:
497 return AF_INET;
498 case 6:
499 return AF_INET6;
500 default:
501 return 0;
502 }
503}
504
505/* Convert from an address parameter type to an address family. */
506static inline int param_type2af(__be16 type)
507{
508 switch (type) {
509 case SCTP_PARAM_IPV4_ADDRESS:
510 return AF_INET;
511 case SCTP_PARAM_IPV6_ADDRESS:
512 return AF_INET6;
513 default:
514 return 0;
515 }
516}
517
518/* Warning: The following hash functions assume a power of two 'size'. */
519/* This is the hash function for the SCTP port hash table. */
520static inline int sctp_phashfn(struct net *net, __u16 lport)
521{
522 return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
523}
524
525/* This is the hash function for the endpoint hash table. */
526static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
527{
528 return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
529}
530
531#define sctp_for_each_hentry(epb, head) \
532 hlist_for_each_entry(epb, head, node)
533
534/* Is a socket of this style? */
535#define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
536static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
537{
538 return sctp_sk(sk)->type == style;
539}
540
541/* Is the association in this state? */
542#define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
543static inline int __sctp_state(const struct sctp_association *asoc,
544 sctp_state_t state)
545{
546 return asoc->state == state;
547}
548
549/* Is the socket in this state? */
550#define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
551static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
552{
553 return sk->sk_state == state;
554}
555
556/* Map v4-mapped v6 address back to v4 address */
557static inline void sctp_v6_map_v4(union sctp_addr *addr)
558{
559 addr->v4.sin_family = AF_INET;
560 addr->v4.sin_port = addr->v6.sin6_port;
561 addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
562}
563
564/* Map v4 address to v4-mapped v6 address */
565static inline void sctp_v4_map_v6(union sctp_addr *addr)
566{
567 __be16 port;
568
569 port = addr->v4.sin_port;
570 addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
571 addr->v6.sin6_port = port;
572 addr->v6.sin6_family = AF_INET6;
573 addr->v6.sin6_flowinfo = 0;
574 addr->v6.sin6_scope_id = 0;
575 addr->v6.sin6_addr.s6_addr32[0] = 0;
576 addr->v6.sin6_addr.s6_addr32[1] = 0;
577 addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
578}
579
580/* The cookie is always 0 since this is how it's used in the
581 * pmtu code.
582 */
583static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
584{
585 if (t->dst && !dst_check(t->dst, t->dst_cookie)) {
586 dst_release(t->dst);
587 t->dst = NULL;
588 }
589
590 return t->dst;
591}
592
593#endif /* __net_sctp_h__ */
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, see
25 * <http://www.gnu.org/licenses/>.
26 *
27 * Please send any bug reports or fixes you make to the
28 * email address(es):
29 * lksctp developers <linux-sctp@vger.kernel.org>
30 *
31 * Written or modified by:
32 * La Monte H.P. Yarroll <piggy@acm.org>
33 * Xingang Guo <xingang.guo@intel.com>
34 * Jon Grimm <jgrimm@us.ibm.com>
35 * Daisy Chang <daisyc@us.ibm.com>
36 * Sridhar Samudrala <sri@us.ibm.com>
37 * Ardelle Fan <ardelle.fan@intel.com>
38 * Ryan Layer <rmlayer@us.ibm.com>
39 * Kevin Gao <kevin.gao@intel.com>
40 */
41
42#ifndef __net_sctp_h__
43#define __net_sctp_h__
44
45/* Header Strategy.
46 * Start getting some control over the header file depencies:
47 * includes
48 * constants
49 * structs
50 * prototypes
51 * macros, externs, and inlines
52 *
53 * Move test_frame specific items out of the kernel headers
54 * and into the test frame headers. This is not perfect in any sense
55 * and will continue to evolve.
56 */
57
58#include <linux/types.h>
59#include <linux/slab.h>
60#include <linux/in.h>
61#include <linux/tty.h>
62#include <linux/proc_fs.h>
63#include <linux/spinlock.h>
64#include <linux/jiffies.h>
65#include <linux/idr.h>
66
67#if IS_ENABLED(CONFIG_IPV6)
68#include <net/ipv6.h>
69#include <net/ip6_route.h>
70#endif
71
72#include <linux/uaccess.h>
73#include <asm/page.h>
74#include <net/sock.h>
75#include <net/snmp.h>
76#include <net/sctp/structs.h>
77#include <net/sctp/constants.h>
78
79#ifdef CONFIG_IP_SCTP_MODULE
80#define SCTP_PROTOSW_FLAG 0
81#else /* static! */
82#define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
83#endif
84
85/* Round an int up to the next multiple of 4. */
86#define SCTP_PAD4(s) (((s)+3)&~3)
87/* Truncate to the previous multiple of 4. */
88#define SCTP_TRUNC4(s) ((s)&~3)
89
90/*
91 * Function declarations.
92 */
93
94/*
95 * sctp/protocol.c
96 */
97int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *addr,
98 enum sctp_scope, gfp_t gfp, int flags);
99struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
100int sctp_register_pf(struct sctp_pf *, sa_family_t);
101void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
102
103/*
104 * sctp/socket.c
105 */
106int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr,
107 int addr_len, int flags);
108int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
109int sctp_inet_listen(struct socket *sock, int backlog);
110void sctp_write_space(struct sock *sk);
111void sctp_data_ready(struct sock *sk);
112__poll_t sctp_poll(struct file *file, struct socket *sock,
113 poll_table *wait);
114void sctp_sock_rfree(struct sk_buff *skb);
115void sctp_copy_sock(struct sock *newsk, struct sock *sk,
116 struct sctp_association *asoc);
117extern struct percpu_counter sctp_sockets_allocated;
118int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
119struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);
120
121void sctp_transport_walk_start(struct rhashtable_iter *iter);
122void sctp_transport_walk_stop(struct rhashtable_iter *iter);
123struct sctp_transport *sctp_transport_get_next(struct net *net,
124 struct rhashtable_iter *iter);
125struct sctp_transport *sctp_transport_get_idx(struct net *net,
126 struct rhashtable_iter *iter, int pos);
127int sctp_transport_lookup_process(int (*cb)(struct sctp_transport *, void *),
128 struct net *net,
129 const union sctp_addr *laddr,
130 const union sctp_addr *paddr, void *p);
131int sctp_for_each_transport(int (*cb)(struct sctp_transport *, void *),
132 int (*cb_done)(struct sctp_transport *, void *),
133 struct net *net, int *pos, void *p);
134int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p);
135int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc,
136 struct sctp_info *info);
137
138/*
139 * sctp/primitive.c
140 */
141int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
142int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
143int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
144int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
145int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
146int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
147int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
148 void *arg);
149
150/*
151 * sctp/input.c
152 */
153int sctp_rcv(struct sk_buff *skb);
154void sctp_v4_err(struct sk_buff *skb, u32 info);
155void sctp_hash_endpoint(struct sctp_endpoint *);
156void sctp_unhash_endpoint(struct sctp_endpoint *);
157struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
158 struct sctphdr *, struct sctp_association **,
159 struct sctp_transport **);
160void sctp_err_finish(struct sock *, struct sctp_transport *);
161void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
162 struct sctp_transport *t, __u32 pmtu);
163void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
164 struct sk_buff *);
165void sctp_icmp_proto_unreachable(struct sock *sk,
166 struct sctp_association *asoc,
167 struct sctp_transport *t);
168void sctp_backlog_migrate(struct sctp_association *assoc,
169 struct sock *oldsk, struct sock *newsk);
170int sctp_transport_hashtable_init(void);
171void sctp_transport_hashtable_destroy(void);
172int sctp_hash_transport(struct sctp_transport *t);
173void sctp_unhash_transport(struct sctp_transport *t);
174struct sctp_transport *sctp_addrs_lookup_transport(
175 struct net *net,
176 const union sctp_addr *laddr,
177 const union sctp_addr *paddr);
178struct sctp_transport *sctp_epaddr_lookup_transport(
179 const struct sctp_endpoint *ep,
180 const union sctp_addr *paddr);
181
182/*
183 * sctp/proc.c
184 */
185int __net_init sctp_proc_init(struct net *net);
186
187/*
188 * sctp/offload.c
189 */
190int sctp_offload_init(void);
191
192/*
193 * sctp/stream_sched.c
194 */
195void sctp_sched_ops_init(void);
196
197/*
198 * sctp/stream.c
199 */
200int sctp_send_reset_streams(struct sctp_association *asoc,
201 struct sctp_reset_streams *params);
202int sctp_send_reset_assoc(struct sctp_association *asoc);
203int sctp_send_add_streams(struct sctp_association *asoc,
204 struct sctp_add_streams *params);
205
206/*
207 * Module global variables
208 */
209
210 /*
211 * sctp/protocol.c
212 */
213extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
214extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
215extern long sysctl_sctp_mem[3];
216extern int sysctl_sctp_rmem[3];
217extern int sysctl_sctp_wmem[3];
218
219/*
220 * Section: Macros, externs, and inlines
221 */
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(net, field) __SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
226#define SCTP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
227
228/* sctp mib definitions */
229enum {
230 SCTP_MIB_NUM = 0,
231 SCTP_MIB_CURRESTAB, /* CurrEstab */
232 SCTP_MIB_ACTIVEESTABS, /* ActiveEstabs */
233 SCTP_MIB_PASSIVEESTABS, /* PassiveEstabs */
234 SCTP_MIB_ABORTEDS, /* Aborteds */
235 SCTP_MIB_SHUTDOWNS, /* Shutdowns */
236 SCTP_MIB_OUTOFBLUES, /* OutOfBlues */
237 SCTP_MIB_CHECKSUMERRORS, /* ChecksumErrors */
238 SCTP_MIB_OUTCTRLCHUNKS, /* OutCtrlChunks */
239 SCTP_MIB_OUTORDERCHUNKS, /* OutOrderChunks */
240 SCTP_MIB_OUTUNORDERCHUNKS, /* OutUnorderChunks */
241 SCTP_MIB_INCTRLCHUNKS, /* InCtrlChunks */
242 SCTP_MIB_INORDERCHUNKS, /* InOrderChunks */
243 SCTP_MIB_INUNORDERCHUNKS, /* InUnorderChunks */
244 SCTP_MIB_FRAGUSRMSGS, /* FragUsrMsgs */
245 SCTP_MIB_REASMUSRMSGS, /* ReasmUsrMsgs */
246 SCTP_MIB_OUTSCTPPACKS, /* OutSCTPPacks */
247 SCTP_MIB_INSCTPPACKS, /* InSCTPPacks */
248 SCTP_MIB_T1_INIT_EXPIREDS,
249 SCTP_MIB_T1_COOKIE_EXPIREDS,
250 SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
251 SCTP_MIB_T3_RTX_EXPIREDS,
252 SCTP_MIB_T4_RTO_EXPIREDS,
253 SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
254 SCTP_MIB_DELAY_SACK_EXPIREDS,
255 SCTP_MIB_AUTOCLOSE_EXPIREDS,
256 SCTP_MIB_T1_RETRANSMITS,
257 SCTP_MIB_T3_RETRANSMITS,
258 SCTP_MIB_PMTUD_RETRANSMITS,
259 SCTP_MIB_FAST_RETRANSMITS,
260 SCTP_MIB_IN_PKT_SOFTIRQ,
261 SCTP_MIB_IN_PKT_BACKLOG,
262 SCTP_MIB_IN_PKT_DISCARDS,
263 SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
264 __SCTP_MIB_MAX
265};
266
267#define SCTP_MIB_MAX __SCTP_MIB_MAX
268struct sctp_mib {
269 unsigned long mibs[SCTP_MIB_MAX];
270};
271
272/* helper function to track stats about max rto and related transport */
273static inline void sctp_max_rto(struct sctp_association *asoc,
274 struct sctp_transport *trans)
275{
276 if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
277 asoc->stats.max_obs_rto = trans->rto;
278 memset(&asoc->stats.obs_rto_ipaddr, 0,
279 sizeof(struct sockaddr_storage));
280 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
281 trans->af_specific->sockaddr_len);
282 }
283}
284
285/*
286 * Macros for keeping a global reference of object allocations.
287 */
288#ifdef CONFIG_SCTP_DBG_OBJCNT
289
290extern atomic_t sctp_dbg_objcnt_sock;
291extern atomic_t sctp_dbg_objcnt_ep;
292extern atomic_t sctp_dbg_objcnt_assoc;
293extern atomic_t sctp_dbg_objcnt_transport;
294extern atomic_t sctp_dbg_objcnt_chunk;
295extern atomic_t sctp_dbg_objcnt_bind_addr;
296extern atomic_t sctp_dbg_objcnt_bind_bucket;
297extern atomic_t sctp_dbg_objcnt_addr;
298extern atomic_t sctp_dbg_objcnt_datamsg;
299extern atomic_t sctp_dbg_objcnt_keys;
300
301/* Macros to atomically increment/decrement objcnt counters. */
302#define SCTP_DBG_OBJCNT_INC(name) \
303atomic_inc(&sctp_dbg_objcnt_## name)
304#define SCTP_DBG_OBJCNT_DEC(name) \
305atomic_dec(&sctp_dbg_objcnt_## name)
306#define SCTP_DBG_OBJCNT(name) \
307atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
308
309/* Macro to help create new entries in in the global array of
310 * objcnt counters.
311 */
312#define SCTP_DBG_OBJCNT_ENTRY(name) \
313{.label= #name, .counter= &sctp_dbg_objcnt_## name}
314
315void sctp_dbg_objcnt_init(struct net *);
316
317#else
318
319#define SCTP_DBG_OBJCNT_INC(name)
320#define SCTP_DBG_OBJCNT_DEC(name)
321
322static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
323
324#endif /* CONFIG_SCTP_DBG_OBJCOUNT */
325
326#if defined CONFIG_SYSCTL
327void sctp_sysctl_register(void);
328void sctp_sysctl_unregister(void);
329int sctp_sysctl_net_register(struct net *net);
330void sctp_sysctl_net_unregister(struct net *net);
331#else
332static inline void sctp_sysctl_register(void) { return; }
333static inline void sctp_sysctl_unregister(void) { return; }
334static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
335static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
336#endif
337
338/* Size of Supported Address Parameter for 'x' address types. */
339#define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
340
341#if IS_ENABLED(CONFIG_IPV6)
342
343void sctp_v6_pf_init(void);
344void sctp_v6_pf_exit(void);
345int sctp_v6_protosw_init(void);
346void sctp_v6_protosw_exit(void);
347int sctp_v6_add_protocol(void);
348void sctp_v6_del_protocol(void);
349
350#else /* #ifdef defined(CONFIG_IPV6) */
351
352static inline void sctp_v6_pf_init(void) { return; }
353static inline void sctp_v6_pf_exit(void) { return; }
354static inline int sctp_v6_protosw_init(void) { return 0; }
355static inline void sctp_v6_protosw_exit(void) { return; }
356static inline int sctp_v6_add_protocol(void) { return 0; }
357static inline void sctp_v6_del_protocol(void) { return; }
358
359#endif /* #if defined(CONFIG_IPV6) */
360
361
362/* Map an association to an assoc_id. */
363static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
364{
365 return asoc ? asoc->assoc_id : 0;
366}
367
368static inline enum sctp_sstat_state
369sctp_assoc_to_state(const struct sctp_association *asoc)
370{
371 /* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
372 * got rid of it in kernel space. Therefore SCTP_CLOSED et al
373 * start at =1 in user space, but actually as =0 in kernel space.
374 * Now that we can not break user space and SCTP_EMPTY is exposed
375 * there, we need to fix it up with an ugly offset not to break
376 * applications. :(
377 */
378 return asoc->state + 1;
379}
380
381/* Look up the association by its id. */
382struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
383
384int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
385
386/* A macro to walk a list of skbs. */
387#define sctp_skb_for_each(pos, head, tmp) \
388 skb_queue_walk_safe(head, pos, tmp)
389
390/**
391 * sctp_list_dequeue - remove from the head of the queue
392 * @list: list to dequeue from
393 *
394 * Remove the head of the list. The head item is
395 * returned or %NULL if the list is empty.
396 */
397
398static inline struct list_head *sctp_list_dequeue(struct list_head *list)
399{
400 struct list_head *result = NULL;
401
402 if (!list_empty(list)) {
403 result = list->next;
404 list_del_init(result);
405 }
406 return result;
407}
408
409/* SCTP version of skb_set_owner_r. We need this one because
410 * of the way we have to do receive buffer accounting on bundled
411 * chunks.
412 */
413static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
414{
415 struct sctp_ulpevent *event = sctp_skb2event(skb);
416
417 skb_orphan(skb);
418 skb->sk = sk;
419 skb->destructor = sctp_sock_rfree;
420 atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
421 /*
422 * This mimics the behavior of skb_set_owner_r
423 */
424 sk->sk_forward_alloc -= event->rmem_len;
425}
426
427/* Tests if the list has one and only one entry. */
428static inline int sctp_list_single_entry(struct list_head *head)
429{
430 return (head->next != head) && (head->next == head->prev);
431}
432
433/* Break down data chunks at this point. */
434static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
435{
436 struct sctp_sock *sp = sctp_sk(asoc->base.sk);
437 struct sctp_af *af = sp->pf->af;
438 int frag = pmtu;
439
440 frag -= af->ip_options_len(asoc->base.sk);
441 frag -= af->net_header_len;
442 frag -= sizeof(struct sctphdr) + sctp_datachk_len(&asoc->stream);
443
444 if (asoc->user_frag)
445 frag = min_t(int, frag, asoc->user_frag);
446
447 frag = SCTP_TRUNC4(min_t(int, frag, SCTP_MAX_CHUNK_LEN -
448 sctp_datachk_len(&asoc->stream)));
449
450 return frag;
451}
452
453static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc)
454{
455 sctp_assoc_sync_pmtu(asoc);
456 asoc->pmtu_pending = 0;
457}
458
459static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
460{
461 return !list_empty(&chunk->list);
462}
463
464/* Walk through a list of TLV parameters. Don't trust the
465 * individual parameter lengths and instead depend on
466 * the chunk length to indicate when to stop. Make sure
467 * there is room for a param header too.
468 */
469#define sctp_walk_params(pos, chunk, member)\
470_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
471
472#define _sctp_walk_params(pos, chunk, end, member)\
473for (pos.v = chunk->member;\
474 (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\
475 (void *)chunk + end) &&\
476 pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
477 ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\
478 pos.v += SCTP_PAD4(ntohs(pos.p->length)))
479
480#define sctp_walk_errors(err, chunk_hdr)\
481_sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
482
483#define _sctp_walk_errors(err, chunk_hdr, end)\
484for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \
485 sizeof(struct sctp_chunkhdr));\
486 ((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\
487 (void *)chunk_hdr + end) &&\
488 (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
489 ntohs(err->length) >= sizeof(struct sctp_errhdr); \
490 err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length))))
491
492#define sctp_walk_fwdtsn(pos, chunk)\
493_sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
494
495#define _sctp_walk_fwdtsn(pos, chunk, end)\
496for (pos = chunk->subh.fwdtsn_hdr->skip;\
497 (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
498 pos++)
499
500/* External references. */
501
502extern struct proto sctp_prot;
503extern struct proto sctpv6_prot;
504void sctp_put_port(struct sock *sk);
505
506extern struct idr sctp_assocs_id;
507extern spinlock_t sctp_assocs_id_lock;
508
509/* Static inline functions. */
510
511/* Convert from an IP version number to an Address Family symbol. */
512static inline int ipver2af(__u8 ipver)
513{
514 switch (ipver) {
515 case 4:
516 return AF_INET;
517 case 6:
518 return AF_INET6;
519 default:
520 return 0;
521 }
522}
523
524/* Convert from an address parameter type to an address family. */
525static inline int param_type2af(__be16 type)
526{
527 switch (type) {
528 case SCTP_PARAM_IPV4_ADDRESS:
529 return AF_INET;
530 case SCTP_PARAM_IPV6_ADDRESS:
531 return AF_INET6;
532 default:
533 return 0;
534 }
535}
536
537/* Warning: The following hash functions assume a power of two 'size'. */
538/* This is the hash function for the SCTP port hash table. */
539static inline int sctp_phashfn(struct net *net, __u16 lport)
540{
541 return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
542}
543
544/* This is the hash function for the endpoint hash table. */
545static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
546{
547 return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
548}
549
550#define sctp_for_each_hentry(epb, head) \
551 hlist_for_each_entry(epb, head, node)
552
553/* Is a socket of this style? */
554#define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
555static inline int __sctp_style(const struct sock *sk,
556 enum sctp_socket_type style)
557{
558 return sctp_sk(sk)->type == style;
559}
560
561/* Is the association in this state? */
562#define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
563static inline int __sctp_state(const struct sctp_association *asoc,
564 enum sctp_state state)
565{
566 return asoc->state == state;
567}
568
569/* Is the socket in this state? */
570#define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
571static inline int __sctp_sstate(const struct sock *sk,
572 enum sctp_sock_state state)
573{
574 return sk->sk_state == state;
575}
576
577/* Map v4-mapped v6 address back to v4 address */
578static inline void sctp_v6_map_v4(union sctp_addr *addr)
579{
580 addr->v4.sin_family = AF_INET;
581 addr->v4.sin_port = addr->v6.sin6_port;
582 addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
583}
584
585/* Map v4 address to v4-mapped v6 address */
586static inline void sctp_v4_map_v6(union sctp_addr *addr)
587{
588 __be16 port;
589
590 port = addr->v4.sin_port;
591 addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
592 addr->v6.sin6_port = port;
593 addr->v6.sin6_family = AF_INET6;
594 addr->v6.sin6_flowinfo = 0;
595 addr->v6.sin6_scope_id = 0;
596 addr->v6.sin6_addr.s6_addr32[0] = 0;
597 addr->v6.sin6_addr.s6_addr32[1] = 0;
598 addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
599}
600
601/* The cookie is always 0 since this is how it's used in the
602 * pmtu code.
603 */
604static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
605{
606 if (t->dst && !dst_check(t->dst, t->dst_cookie))
607 sctp_transport_dst_release(t);
608
609 return t->dst;
610}
611
612static inline bool sctp_transport_pmtu_check(struct sctp_transport *t)
613{
614 __u32 pmtu = max_t(size_t, SCTP_TRUNC4(dst_mtu(t->dst)),
615 SCTP_DEFAULT_MINSEGMENT);
616
617 if (t->pathmtu == pmtu)
618 return true;
619
620 t->pathmtu = pmtu;
621
622 return false;
623}
624
625#endif /* __net_sctp_h__ */