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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001-2003 Intel Corp.
7 *
8 * This file is part of the SCTP kernel implementation
9 *
10 * The base lksctp header.
11 *
12 * Please send any bug reports or fixes you make to the
13 * email address(es):
14 * lksctp developers <linux-sctp@vger.kernel.org>
15 *
16 * Written or modified by:
17 * La Monte H.P. Yarroll <piggy@acm.org>
18 * Xingang Guo <xingang.guo@intel.com>
19 * Jon Grimm <jgrimm@us.ibm.com>
20 * Daisy Chang <daisyc@us.ibm.com>
21 * Sridhar Samudrala <sri@us.ibm.com>
22 * Ardelle Fan <ardelle.fan@intel.com>
23 * Ryan Layer <rmlayer@us.ibm.com>
24 * Kevin Gao <kevin.gao@intel.com>
25 */
26
27#ifndef __net_sctp_h__
28#define __net_sctp_h__
29
30/* Header Strategy.
31 * Start getting some control over the header file depencies:
32 * includes
33 * constants
34 * structs
35 * prototypes
36 * macros, externs, and inlines
37 *
38 * Move test_frame specific items out of the kernel headers
39 * and into the test frame headers. This is not perfect in any sense
40 * and will continue to evolve.
41 */
42
43#include <linux/types.h>
44#include <linux/slab.h>
45#include <linux/in.h>
46#include <linux/tty.h>
47#include <linux/proc_fs.h>
48#include <linux/spinlock.h>
49#include <linux/jiffies.h>
50#include <linux/idr.h>
51
52#if IS_ENABLED(CONFIG_IPV6)
53#include <net/ipv6.h>
54#include <net/ip6_route.h>
55#endif
56
57#include <linux/uaccess.h>
58#include <asm/page.h>
59#include <net/sock.h>
60#include <net/snmp.h>
61#include <net/sctp/structs.h>
62#include <net/sctp/constants.h>
63
64#ifdef CONFIG_IP_SCTP_MODULE
65#define SCTP_PROTOSW_FLAG 0
66#else /* static! */
67#define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
68#endif
69
70/* Round an int up to the next multiple of 4. */
71#define SCTP_PAD4(s) (((s)+3)&~3)
72/* Truncate to the previous multiple of 4. */
73#define SCTP_TRUNC4(s) ((s)&~3)
74
75/*
76 * Function declarations.
77 */
78
79/*
80 * sctp/protocol.c
81 */
82int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *addr,
83 enum sctp_scope, gfp_t gfp, int flags);
84struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
85int sctp_register_pf(struct sctp_pf *, sa_family_t);
86void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
87
88/*
89 * sctp/socket.c
90 */
91int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr,
92 int addr_len, int flags);
93int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
94int sctp_inet_listen(struct socket *sock, int backlog);
95void sctp_write_space(struct sock *sk);
96void sctp_data_ready(struct sock *sk);
97__poll_t sctp_poll(struct file *file, struct socket *sock,
98 poll_table *wait);
99void sctp_sock_rfree(struct sk_buff *skb);
100void sctp_copy_sock(struct sock *newsk, struct sock *sk,
101 struct sctp_association *asoc);
102extern struct percpu_counter sctp_sockets_allocated;
103int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
104struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);
105
106void sctp_transport_walk_start(struct rhashtable_iter *iter);
107void sctp_transport_walk_stop(struct rhashtable_iter *iter);
108struct sctp_transport *sctp_transport_get_next(struct net *net,
109 struct rhashtable_iter *iter);
110struct sctp_transport *sctp_transport_get_idx(struct net *net,
111 struct rhashtable_iter *iter, int pos);
112int sctp_transport_lookup_process(int (*cb)(struct sctp_transport *, void *),
113 struct net *net,
114 const union sctp_addr *laddr,
115 const union sctp_addr *paddr, void *p);
116int sctp_for_each_transport(int (*cb)(struct sctp_transport *, void *),
117 int (*cb_done)(struct sctp_transport *, void *),
118 struct net *net, int *pos, void *p);
119int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p);
120int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc,
121 struct sctp_info *info);
122
123/*
124 * sctp/primitive.c
125 */
126int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
127int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
128int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
129int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
130int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
131int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
132int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
133 void *arg);
134
135/*
136 * sctp/input.c
137 */
138int sctp_rcv(struct sk_buff *skb);
139int sctp_v4_err(struct sk_buff *skb, u32 info);
140int sctp_hash_endpoint(struct sctp_endpoint *ep);
141void sctp_unhash_endpoint(struct sctp_endpoint *);
142struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
143 struct sctphdr *, struct sctp_association **,
144 struct sctp_transport **);
145void sctp_err_finish(struct sock *, struct sctp_transport *);
146void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
147 struct sctp_transport *t, __u32 pmtu);
148void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
149 struct sk_buff *);
150void sctp_icmp_proto_unreachable(struct sock *sk,
151 struct sctp_association *asoc,
152 struct sctp_transport *t);
153void sctp_backlog_migrate(struct sctp_association *assoc,
154 struct sock *oldsk, struct sock *newsk);
155int sctp_transport_hashtable_init(void);
156void sctp_transport_hashtable_destroy(void);
157int sctp_hash_transport(struct sctp_transport *t);
158void sctp_unhash_transport(struct sctp_transport *t);
159struct sctp_transport *sctp_addrs_lookup_transport(
160 struct net *net,
161 const union sctp_addr *laddr,
162 const union sctp_addr *paddr);
163struct sctp_transport *sctp_epaddr_lookup_transport(
164 const struct sctp_endpoint *ep,
165 const union sctp_addr *paddr);
166
167/*
168 * sctp/proc.c
169 */
170int __net_init sctp_proc_init(struct net *net);
171
172/*
173 * sctp/offload.c
174 */
175int sctp_offload_init(void);
176
177/*
178 * sctp/stream_sched.c
179 */
180void sctp_sched_ops_init(void);
181
182/*
183 * sctp/stream.c
184 */
185int sctp_send_reset_streams(struct sctp_association *asoc,
186 struct sctp_reset_streams *params);
187int sctp_send_reset_assoc(struct sctp_association *asoc);
188int sctp_send_add_streams(struct sctp_association *asoc,
189 struct sctp_add_streams *params);
190
191/*
192 * Module global variables
193 */
194
195 /*
196 * sctp/protocol.c
197 */
198extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
199extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
200extern long sysctl_sctp_mem[3];
201extern int sysctl_sctp_rmem[3];
202extern int sysctl_sctp_wmem[3];
203
204/*
205 * Section: Macros, externs, and inlines
206 */
207
208/* SCTP SNMP MIB stats handlers */
209#define SCTP_INC_STATS(net, field) SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
210#define __SCTP_INC_STATS(net, field) __SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
211#define SCTP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
212
213/* sctp mib definitions */
214enum {
215 SCTP_MIB_NUM = 0,
216 SCTP_MIB_CURRESTAB, /* CurrEstab */
217 SCTP_MIB_ACTIVEESTABS, /* ActiveEstabs */
218 SCTP_MIB_PASSIVEESTABS, /* PassiveEstabs */
219 SCTP_MIB_ABORTEDS, /* Aborteds */
220 SCTP_MIB_SHUTDOWNS, /* Shutdowns */
221 SCTP_MIB_OUTOFBLUES, /* OutOfBlues */
222 SCTP_MIB_CHECKSUMERRORS, /* ChecksumErrors */
223 SCTP_MIB_OUTCTRLCHUNKS, /* OutCtrlChunks */
224 SCTP_MIB_OUTORDERCHUNKS, /* OutOrderChunks */
225 SCTP_MIB_OUTUNORDERCHUNKS, /* OutUnorderChunks */
226 SCTP_MIB_INCTRLCHUNKS, /* InCtrlChunks */
227 SCTP_MIB_INORDERCHUNKS, /* InOrderChunks */
228 SCTP_MIB_INUNORDERCHUNKS, /* InUnorderChunks */
229 SCTP_MIB_FRAGUSRMSGS, /* FragUsrMsgs */
230 SCTP_MIB_REASMUSRMSGS, /* ReasmUsrMsgs */
231 SCTP_MIB_OUTSCTPPACKS, /* OutSCTPPacks */
232 SCTP_MIB_INSCTPPACKS, /* InSCTPPacks */
233 SCTP_MIB_T1_INIT_EXPIREDS,
234 SCTP_MIB_T1_COOKIE_EXPIREDS,
235 SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
236 SCTP_MIB_T3_RTX_EXPIREDS,
237 SCTP_MIB_T4_RTO_EXPIREDS,
238 SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
239 SCTP_MIB_DELAY_SACK_EXPIREDS,
240 SCTP_MIB_AUTOCLOSE_EXPIREDS,
241 SCTP_MIB_T1_RETRANSMITS,
242 SCTP_MIB_T3_RETRANSMITS,
243 SCTP_MIB_PMTUD_RETRANSMITS,
244 SCTP_MIB_FAST_RETRANSMITS,
245 SCTP_MIB_IN_PKT_SOFTIRQ,
246 SCTP_MIB_IN_PKT_BACKLOG,
247 SCTP_MIB_IN_PKT_DISCARDS,
248 SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
249 __SCTP_MIB_MAX
250};
251
252#define SCTP_MIB_MAX __SCTP_MIB_MAX
253struct sctp_mib {
254 unsigned long mibs[SCTP_MIB_MAX];
255};
256
257/* helper function to track stats about max rto and related transport */
258static inline void sctp_max_rto(struct sctp_association *asoc,
259 struct sctp_transport *trans)
260{
261 if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
262 asoc->stats.max_obs_rto = trans->rto;
263 memset(&asoc->stats.obs_rto_ipaddr, 0,
264 sizeof(struct sockaddr_storage));
265 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
266 trans->af_specific->sockaddr_len);
267 }
268}
269
270/*
271 * Macros for keeping a global reference of object allocations.
272 */
273#ifdef CONFIG_SCTP_DBG_OBJCNT
274
275extern atomic_t sctp_dbg_objcnt_sock;
276extern atomic_t sctp_dbg_objcnt_ep;
277extern atomic_t sctp_dbg_objcnt_assoc;
278extern atomic_t sctp_dbg_objcnt_transport;
279extern atomic_t sctp_dbg_objcnt_chunk;
280extern atomic_t sctp_dbg_objcnt_bind_addr;
281extern atomic_t sctp_dbg_objcnt_bind_bucket;
282extern atomic_t sctp_dbg_objcnt_addr;
283extern atomic_t sctp_dbg_objcnt_datamsg;
284extern atomic_t sctp_dbg_objcnt_keys;
285
286/* Macros to atomically increment/decrement objcnt counters. */
287#define SCTP_DBG_OBJCNT_INC(name) \
288atomic_inc(&sctp_dbg_objcnt_## name)
289#define SCTP_DBG_OBJCNT_DEC(name) \
290atomic_dec(&sctp_dbg_objcnt_## name)
291#define SCTP_DBG_OBJCNT(name) \
292atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
293
294/* Macro to help create new entries in in the global array of
295 * objcnt counters.
296 */
297#define SCTP_DBG_OBJCNT_ENTRY(name) \
298{.label= #name, .counter= &sctp_dbg_objcnt_## name}
299
300void sctp_dbg_objcnt_init(struct net *);
301
302#else
303
304#define SCTP_DBG_OBJCNT_INC(name)
305#define SCTP_DBG_OBJCNT_DEC(name)
306
307static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
308
309#endif /* CONFIG_SCTP_DBG_OBJCOUNT */
310
311#if defined CONFIG_SYSCTL
312void sctp_sysctl_register(void);
313void sctp_sysctl_unregister(void);
314int sctp_sysctl_net_register(struct net *net);
315void sctp_sysctl_net_unregister(struct net *net);
316#else
317static inline void sctp_sysctl_register(void) { return; }
318static inline void sctp_sysctl_unregister(void) { return; }
319static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
320static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
321#endif
322
323/* Size of Supported Address Parameter for 'x' address types. */
324#define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
325
326#if IS_ENABLED(CONFIG_IPV6)
327
328void sctp_v6_pf_init(void);
329void sctp_v6_pf_exit(void);
330int sctp_v6_protosw_init(void);
331void sctp_v6_protosw_exit(void);
332int sctp_v6_add_protocol(void);
333void sctp_v6_del_protocol(void);
334
335#else /* #ifdef defined(CONFIG_IPV6) */
336
337static inline void sctp_v6_pf_init(void) { return; }
338static inline void sctp_v6_pf_exit(void) { return; }
339static inline int sctp_v6_protosw_init(void) { return 0; }
340static inline void sctp_v6_protosw_exit(void) { return; }
341static inline int sctp_v6_add_protocol(void) { return 0; }
342static inline void sctp_v6_del_protocol(void) { return; }
343
344#endif /* #if defined(CONFIG_IPV6) */
345
346
347/* Map an association to an assoc_id. */
348static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
349{
350 return asoc ? asoc->assoc_id : 0;
351}
352
353static inline enum sctp_sstat_state
354sctp_assoc_to_state(const struct sctp_association *asoc)
355{
356 /* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
357 * got rid of it in kernel space. Therefore SCTP_CLOSED et al
358 * start at =1 in user space, but actually as =0 in kernel space.
359 * Now that we can not break user space and SCTP_EMPTY is exposed
360 * there, we need to fix it up with an ugly offset not to break
361 * applications. :(
362 */
363 return asoc->state + 1;
364}
365
366/* Look up the association by its id. */
367struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
368
369int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
370
371/* A macro to walk a list of skbs. */
372#define sctp_skb_for_each(pos, head, tmp) \
373 skb_queue_walk_safe(head, pos, tmp)
374
375/**
376 * sctp_list_dequeue - remove from the head of the queue
377 * @list: list to dequeue from
378 *
379 * Remove the head of the list. The head item is
380 * returned or %NULL if the list is empty.
381 */
382
383static inline struct list_head *sctp_list_dequeue(struct list_head *list)
384{
385 struct list_head *result = NULL;
386
387 if (!list_empty(list)) {
388 result = list->next;
389 list_del_init(result);
390 }
391 return result;
392}
393
394/* SCTP version of skb_set_owner_r. We need this one because
395 * of the way we have to do receive buffer accounting on bundled
396 * chunks.
397 */
398static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
399{
400 struct sctp_ulpevent *event = sctp_skb2event(skb);
401
402 skb_orphan(skb);
403 skb->sk = sk;
404 skb->destructor = sctp_sock_rfree;
405 atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
406 /*
407 * This mimics the behavior of skb_set_owner_r
408 */
409 sk_mem_charge(sk, event->rmem_len);
410}
411
412/* Tests if the list has one and only one entry. */
413static inline int sctp_list_single_entry(struct list_head *head)
414{
415 return (head->next != head) && (head->next == head->prev);
416}
417
418static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
419{
420 return !list_empty(&chunk->list);
421}
422
423/* Walk through a list of TLV parameters. Don't trust the
424 * individual parameter lengths and instead depend on
425 * the chunk length to indicate when to stop. Make sure
426 * there is room for a param header too.
427 */
428#define sctp_walk_params(pos, chunk, member)\
429_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
430
431#define _sctp_walk_params(pos, chunk, end, member)\
432for (pos.v = chunk->member;\
433 (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\
434 (void *)chunk + end) &&\
435 pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
436 ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\
437 pos.v += SCTP_PAD4(ntohs(pos.p->length)))
438
439#define sctp_walk_errors(err, chunk_hdr)\
440_sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
441
442#define _sctp_walk_errors(err, chunk_hdr, end)\
443for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \
444 sizeof(struct sctp_chunkhdr));\
445 ((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\
446 (void *)chunk_hdr + end) &&\
447 (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
448 ntohs(err->length) >= sizeof(struct sctp_errhdr); \
449 err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length))))
450
451#define sctp_walk_fwdtsn(pos, chunk)\
452_sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
453
454#define _sctp_walk_fwdtsn(pos, chunk, end)\
455for (pos = chunk->subh.fwdtsn_hdr->skip;\
456 (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
457 pos++)
458
459/* External references. */
460
461extern struct proto sctp_prot;
462extern struct proto sctpv6_prot;
463void sctp_put_port(struct sock *sk);
464
465extern struct idr sctp_assocs_id;
466extern spinlock_t sctp_assocs_id_lock;
467
468/* Static inline functions. */
469
470/* Convert from an IP version number to an Address Family symbol. */
471static inline int ipver2af(__u8 ipver)
472{
473 switch (ipver) {
474 case 4:
475 return AF_INET;
476 case 6:
477 return AF_INET6;
478 default:
479 return 0;
480 }
481}
482
483/* Convert from an address parameter type to an address family. */
484static inline int param_type2af(__be16 type)
485{
486 switch (type) {
487 case SCTP_PARAM_IPV4_ADDRESS:
488 return AF_INET;
489 case SCTP_PARAM_IPV6_ADDRESS:
490 return AF_INET6;
491 default:
492 return 0;
493 }
494}
495
496/* Warning: The following hash functions assume a power of two 'size'. */
497/* This is the hash function for the SCTP port hash table. */
498static inline int sctp_phashfn(struct net *net, __u16 lport)
499{
500 return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
501}
502
503/* This is the hash function for the endpoint hash table. */
504static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
505{
506 return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
507}
508
509#define sctp_for_each_hentry(epb, head) \
510 hlist_for_each_entry(epb, head, node)
511
512/* Is a socket of this style? */
513#define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
514static inline int __sctp_style(const struct sock *sk,
515 enum sctp_socket_type style)
516{
517 return sctp_sk(sk)->type == style;
518}
519
520/* Is the association in this state? */
521#define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
522static inline int __sctp_state(const struct sctp_association *asoc,
523 enum sctp_state state)
524{
525 return asoc->state == state;
526}
527
528/* Is the socket in this state? */
529#define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
530static inline int __sctp_sstate(const struct sock *sk,
531 enum sctp_sock_state state)
532{
533 return sk->sk_state == state;
534}
535
536/* Map v4-mapped v6 address back to v4 address */
537static inline void sctp_v6_map_v4(union sctp_addr *addr)
538{
539 addr->v4.sin_family = AF_INET;
540 addr->v4.sin_port = addr->v6.sin6_port;
541 addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
542}
543
544/* Map v4 address to v4-mapped v6 address */
545static inline void sctp_v4_map_v6(union sctp_addr *addr)
546{
547 __be16 port;
548
549 port = addr->v4.sin_port;
550 addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
551 addr->v6.sin6_port = port;
552 addr->v6.sin6_family = AF_INET6;
553 addr->v6.sin6_flowinfo = 0;
554 addr->v6.sin6_scope_id = 0;
555 addr->v6.sin6_addr.s6_addr32[0] = 0;
556 addr->v6.sin6_addr.s6_addr32[1] = 0;
557 addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
558}
559
560/* The cookie is always 0 since this is how it's used in the
561 * pmtu code.
562 */
563static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
564{
565 if (t->dst && !dst_check(t->dst, t->dst_cookie))
566 sctp_transport_dst_release(t);
567
568 return t->dst;
569}
570
571/* Calculate max payload size given a MTU, or the total overhead if
572 * given MTU is zero
573 */
574static inline __u32 sctp_mtu_payload(const struct sctp_sock *sp,
575 __u32 mtu, __u32 extra)
576{
577 __u32 overhead = sizeof(struct sctphdr) + extra;
578
579 if (sp)
580 overhead += sp->pf->af->net_header_len;
581 else
582 overhead += sizeof(struct ipv6hdr);
583
584 if (WARN_ON_ONCE(mtu && mtu <= overhead))
585 mtu = overhead;
586
587 return mtu ? mtu - overhead : overhead;
588}
589
590static inline __u32 sctp_dst_mtu(const struct dst_entry *dst)
591{
592 return SCTP_TRUNC4(max_t(__u32, dst_mtu(dst),
593 SCTP_DEFAULT_MINSEGMENT));
594}
595
596static inline bool sctp_transport_pmtu_check(struct sctp_transport *t)
597{
598 __u32 pmtu = sctp_dst_mtu(t->dst);
599
600 if (t->pathmtu == pmtu)
601 return true;
602
603 t->pathmtu = pmtu;
604
605 return false;
606}
607
608static inline __u32 sctp_min_frag_point(struct sctp_sock *sp, __u16 datasize)
609{
610 return sctp_mtu_payload(sp, SCTP_DEFAULT_MINSEGMENT, datasize);
611}
612
613static inline bool sctp_newsk_ready(const struct sock *sk)
614{
615 return sock_flag(sk, SOCK_DEAD) || sk->sk_socket;
616}
617
618#endif /* __net_sctp_h__ */
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001-2003 Intel Corp.
7 *
8 * This file is part of the SCTP kernel implementation
9 *
10 * The base lksctp header.
11 *
12 * Please send any bug reports or fixes you make to the
13 * email address(es):
14 * lksctp developers <linux-sctp@vger.kernel.org>
15 *
16 * Written or modified by:
17 * La Monte H.P. Yarroll <piggy@acm.org>
18 * Xingang Guo <xingang.guo@intel.com>
19 * Jon Grimm <jgrimm@us.ibm.com>
20 * Daisy Chang <daisyc@us.ibm.com>
21 * Sridhar Samudrala <sri@us.ibm.com>
22 * Ardelle Fan <ardelle.fan@intel.com>
23 * Ryan Layer <rmlayer@us.ibm.com>
24 * Kevin Gao <kevin.gao@intel.com>
25 */
26
27#ifndef __net_sctp_h__
28#define __net_sctp_h__
29
30/* Header Strategy.
31 * Start getting some control over the header file depencies:
32 * includes
33 * constants
34 * structs
35 * prototypes
36 * macros, externs, and inlines
37 *
38 * Move test_frame specific items out of the kernel headers
39 * and into the test frame headers. This is not perfect in any sense
40 * and will continue to evolve.
41 */
42
43#include <linux/types.h>
44#include <linux/slab.h>
45#include <linux/in.h>
46#include <linux/tty.h>
47#include <linux/proc_fs.h>
48#include <linux/spinlock.h>
49#include <linux/jiffies.h>
50#include <linux/idr.h>
51
52#if IS_ENABLED(CONFIG_IPV6)
53#include <net/ipv6.h>
54#include <net/ip6_route.h>
55#endif
56
57#include <linux/uaccess.h>
58#include <asm/page.h>
59#include <net/sock.h>
60#include <net/snmp.h>
61#include <net/sctp/structs.h>
62#include <net/sctp/constants.h>
63
64#ifdef CONFIG_IP_SCTP_MODULE
65#define SCTP_PROTOSW_FLAG 0
66#else /* static! */
67#define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
68#endif
69
70/*
71 * Function declarations.
72 */
73
74/*
75 * sctp/protocol.c
76 */
77int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *addr,
78 enum sctp_scope, gfp_t gfp, int flags);
79struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
80int sctp_register_pf(struct sctp_pf *, sa_family_t);
81void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
82int sctp_udp_sock_start(struct net *net);
83void sctp_udp_sock_stop(struct net *net);
84
85/*
86 * sctp/socket.c
87 */
88int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr,
89 int addr_len, int flags);
90int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
91int sctp_inet_listen(struct socket *sock, int backlog);
92void sctp_write_space(struct sock *sk);
93void sctp_data_ready(struct sock *sk);
94__poll_t sctp_poll(struct file *file, struct socket *sock,
95 poll_table *wait);
96void sctp_sock_rfree(struct sk_buff *skb);
97void sctp_copy_sock(struct sock *newsk, struct sock *sk,
98 struct sctp_association *asoc);
99extern struct percpu_counter sctp_sockets_allocated;
100int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
101struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int *);
102
103typedef int (*sctp_callback_t)(struct sctp_endpoint *, struct sctp_transport *, void *);
104void sctp_transport_walk_start(struct rhashtable_iter *iter);
105void sctp_transport_walk_stop(struct rhashtable_iter *iter);
106struct sctp_transport *sctp_transport_get_next(struct net *net,
107 struct rhashtable_iter *iter);
108struct sctp_transport *sctp_transport_get_idx(struct net *net,
109 struct rhashtable_iter *iter, int pos);
110int sctp_transport_lookup_process(sctp_callback_t cb, struct net *net,
111 const union sctp_addr *laddr,
112 const union sctp_addr *paddr, void *p, int dif);
113int sctp_transport_traverse_process(sctp_callback_t cb, sctp_callback_t cb_done,
114 struct net *net, int *pos, void *p);
115int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p);
116int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc,
117 struct sctp_info *info);
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);
128int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
129 void *arg);
130
131/*
132 * sctp/input.c
133 */
134int sctp_rcv(struct sk_buff *skb);
135int sctp_v4_err(struct sk_buff *skb, u32 info);
136int sctp_hash_endpoint(struct sctp_endpoint *ep);
137void sctp_unhash_endpoint(struct sctp_endpoint *);
138struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
139 struct sctphdr *, struct sctp_association **,
140 struct sctp_transport **);
141void sctp_err_finish(struct sock *, struct sctp_transport *);
142int sctp_udp_v4_err(struct sock *sk, struct sk_buff *skb);
143int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb);
144void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
145 struct sctp_transport *t, __u32 pmtu);
146void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
147 struct sk_buff *);
148void sctp_icmp_proto_unreachable(struct sock *sk,
149 struct sctp_association *asoc,
150 struct sctp_transport *t);
151void sctp_backlog_migrate(struct sctp_association *assoc,
152 struct sock *oldsk, struct sock *newsk);
153int sctp_transport_hashtable_init(void);
154void sctp_transport_hashtable_destroy(void);
155int sctp_hash_transport(struct sctp_transport *t);
156void sctp_unhash_transport(struct sctp_transport *t);
157struct sctp_transport *sctp_addrs_lookup_transport(
158 struct net *net,
159 const union sctp_addr *laddr,
160 const union sctp_addr *paddr,
161 int dif, int sdif);
162struct sctp_transport *sctp_epaddr_lookup_transport(
163 const struct sctp_endpoint *ep,
164 const union sctp_addr *paddr);
165bool sctp_sk_bound_dev_eq(struct net *net, int bound_dev_if, int dif, int sdif);
166
167/*
168 * sctp/proc.c
169 */
170int __net_init sctp_proc_init(struct net *net);
171
172/*
173 * sctp/offload.c
174 */
175int sctp_offload_init(void);
176
177/*
178 * sctp/stream_sched.c
179 */
180void sctp_sched_ops_init(void);
181
182/*
183 * sctp/stream.c
184 */
185int sctp_send_reset_streams(struct sctp_association *asoc,
186 struct sctp_reset_streams *params);
187int sctp_send_reset_assoc(struct sctp_association *asoc);
188int sctp_send_add_streams(struct sctp_association *asoc,
189 struct sctp_add_streams *params);
190
191/*
192 * Module global variables
193 */
194
195 /*
196 * sctp/protocol.c
197 */
198extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
199extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
200extern long sysctl_sctp_mem[3];
201extern int sysctl_sctp_rmem[3];
202extern int sysctl_sctp_wmem[3];
203
204/*
205 * Section: Macros, externs, and inlines
206 */
207
208/* SCTP SNMP MIB stats handlers */
209#define SCTP_INC_STATS(net, field) SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
210#define __SCTP_INC_STATS(net, field) __SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
211#define SCTP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
212
213/* sctp mib definitions */
214enum {
215 SCTP_MIB_NUM = 0,
216 SCTP_MIB_CURRESTAB, /* CurrEstab */
217 SCTP_MIB_ACTIVEESTABS, /* ActiveEstabs */
218 SCTP_MIB_PASSIVEESTABS, /* PassiveEstabs */
219 SCTP_MIB_ABORTEDS, /* Aborteds */
220 SCTP_MIB_SHUTDOWNS, /* Shutdowns */
221 SCTP_MIB_OUTOFBLUES, /* OutOfBlues */
222 SCTP_MIB_CHECKSUMERRORS, /* ChecksumErrors */
223 SCTP_MIB_OUTCTRLCHUNKS, /* OutCtrlChunks */
224 SCTP_MIB_OUTORDERCHUNKS, /* OutOrderChunks */
225 SCTP_MIB_OUTUNORDERCHUNKS, /* OutUnorderChunks */
226 SCTP_MIB_INCTRLCHUNKS, /* InCtrlChunks */
227 SCTP_MIB_INORDERCHUNKS, /* InOrderChunks */
228 SCTP_MIB_INUNORDERCHUNKS, /* InUnorderChunks */
229 SCTP_MIB_FRAGUSRMSGS, /* FragUsrMsgs */
230 SCTP_MIB_REASMUSRMSGS, /* ReasmUsrMsgs */
231 SCTP_MIB_OUTSCTPPACKS, /* OutSCTPPacks */
232 SCTP_MIB_INSCTPPACKS, /* InSCTPPacks */
233 SCTP_MIB_T1_INIT_EXPIREDS,
234 SCTP_MIB_T1_COOKIE_EXPIREDS,
235 SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
236 SCTP_MIB_T3_RTX_EXPIREDS,
237 SCTP_MIB_T4_RTO_EXPIREDS,
238 SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
239 SCTP_MIB_DELAY_SACK_EXPIREDS,
240 SCTP_MIB_AUTOCLOSE_EXPIREDS,
241 SCTP_MIB_T1_RETRANSMITS,
242 SCTP_MIB_T3_RETRANSMITS,
243 SCTP_MIB_PMTUD_RETRANSMITS,
244 SCTP_MIB_FAST_RETRANSMITS,
245 SCTP_MIB_IN_PKT_SOFTIRQ,
246 SCTP_MIB_IN_PKT_BACKLOG,
247 SCTP_MIB_IN_PKT_DISCARDS,
248 SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
249 __SCTP_MIB_MAX
250};
251
252#define SCTP_MIB_MAX __SCTP_MIB_MAX
253struct sctp_mib {
254 unsigned long mibs[SCTP_MIB_MAX];
255};
256
257/* helper function to track stats about max rto and related transport */
258static inline void sctp_max_rto(struct sctp_association *asoc,
259 struct sctp_transport *trans)
260{
261 if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
262 asoc->stats.max_obs_rto = trans->rto;
263 memset(&asoc->stats.obs_rto_ipaddr, 0,
264 sizeof(struct sockaddr_storage));
265 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
266 trans->af_specific->sockaddr_len);
267 }
268}
269
270/*
271 * Macros for keeping a global reference of object allocations.
272 */
273#ifdef CONFIG_SCTP_DBG_OBJCNT
274
275extern atomic_t sctp_dbg_objcnt_sock;
276extern atomic_t sctp_dbg_objcnt_ep;
277extern atomic_t sctp_dbg_objcnt_assoc;
278extern atomic_t sctp_dbg_objcnt_transport;
279extern atomic_t sctp_dbg_objcnt_chunk;
280extern atomic_t sctp_dbg_objcnt_bind_addr;
281extern atomic_t sctp_dbg_objcnt_bind_bucket;
282extern atomic_t sctp_dbg_objcnt_addr;
283extern atomic_t sctp_dbg_objcnt_datamsg;
284extern atomic_t sctp_dbg_objcnt_keys;
285
286/* Macros to atomically increment/decrement objcnt counters. */
287#define SCTP_DBG_OBJCNT_INC(name) \
288atomic_inc(&sctp_dbg_objcnt_## name)
289#define SCTP_DBG_OBJCNT_DEC(name) \
290atomic_dec(&sctp_dbg_objcnt_## name)
291#define SCTP_DBG_OBJCNT(name) \
292atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
293
294/* Macro to help create new entries in the global array of
295 * objcnt counters.
296 */
297#define SCTP_DBG_OBJCNT_ENTRY(name) \
298{.label= #name, .counter= &sctp_dbg_objcnt_## name}
299
300void sctp_dbg_objcnt_init(struct net *);
301
302#else
303
304#define SCTP_DBG_OBJCNT_INC(name)
305#define SCTP_DBG_OBJCNT_DEC(name)
306
307static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
308
309#endif /* CONFIG_SCTP_DBG_OBJCOUNT */
310
311#if defined CONFIG_SYSCTL
312void sctp_sysctl_register(void);
313void sctp_sysctl_unregister(void);
314int sctp_sysctl_net_register(struct net *net);
315void sctp_sysctl_net_unregister(struct net *net);
316#else
317static inline void sctp_sysctl_register(void) { return; }
318static inline void sctp_sysctl_unregister(void) { return; }
319static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
320static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
321#endif
322
323/* Size of Supported Address Parameter for 'x' address types. */
324#define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
325
326#if IS_ENABLED(CONFIG_IPV6)
327
328void sctp_v6_pf_init(void);
329void sctp_v6_pf_exit(void);
330int sctp_v6_protosw_init(void);
331void sctp_v6_protosw_exit(void);
332int sctp_v6_add_protocol(void);
333void sctp_v6_del_protocol(void);
334
335#else /* #ifdef defined(CONFIG_IPV6) */
336
337static inline void sctp_v6_pf_init(void) { return; }
338static inline void sctp_v6_pf_exit(void) { return; }
339static inline int sctp_v6_protosw_init(void) { return 0; }
340static inline void sctp_v6_protosw_exit(void) { return; }
341static inline int sctp_v6_add_protocol(void) { return 0; }
342static inline void sctp_v6_del_protocol(void) { return; }
343
344#endif /* #if defined(CONFIG_IPV6) */
345
346
347/* Map an association to an assoc_id. */
348static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
349{
350 return asoc ? asoc->assoc_id : 0;
351}
352
353static inline enum sctp_sstat_state
354sctp_assoc_to_state(const struct sctp_association *asoc)
355{
356 /* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
357 * got rid of it in kernel space. Therefore SCTP_CLOSED et al
358 * start at =1 in user space, but actually as =0 in kernel space.
359 * Now that we can not break user space and SCTP_EMPTY is exposed
360 * there, we need to fix it up with an ugly offset not to break
361 * applications. :(
362 */
363 return asoc->state + 1;
364}
365
366/* Look up the association by its id. */
367struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
368
369int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
370
371/* A macro to walk a list of skbs. */
372#define sctp_skb_for_each(pos, head, tmp) \
373 skb_queue_walk_safe(head, pos, tmp)
374
375/**
376 * sctp_list_dequeue - remove from the head of the queue
377 * @list: list to dequeue from
378 *
379 * Remove the head of the list. The head item is
380 * returned or %NULL if the list is empty.
381 */
382
383static inline struct list_head *sctp_list_dequeue(struct list_head *list)
384{
385 struct list_head *result = NULL;
386
387 if (!list_empty(list)) {
388 result = list->next;
389 list_del_init(result);
390 }
391 return result;
392}
393
394/* SCTP version of skb_set_owner_r. We need this one because
395 * of the way we have to do receive buffer accounting on bundled
396 * chunks.
397 */
398static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
399{
400 struct sctp_ulpevent *event = sctp_skb2event(skb);
401
402 skb_orphan(skb);
403 skb->sk = sk;
404 skb->destructor = sctp_sock_rfree;
405 atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
406 /*
407 * This mimics the behavior of skb_set_owner_r
408 */
409 sk_mem_charge(sk, event->rmem_len);
410}
411
412/* Tests if the list has one and only one entry. */
413static inline int sctp_list_single_entry(struct list_head *head)
414{
415 return list_is_singular(head);
416}
417
418static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
419{
420 return !list_empty(&chunk->list);
421}
422
423/* Walk through a list of TLV parameters. Don't trust the
424 * individual parameter lengths and instead depend on
425 * the chunk length to indicate when to stop. Make sure
426 * there is room for a param header too.
427 */
428#define sctp_walk_params(pos, chunk, member)\
429_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
430
431#define _sctp_walk_params(pos, chunk, end, member)\
432for (pos.v = chunk->member;\
433 (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\
434 (void *)chunk + end) &&\
435 pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
436 ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\
437 pos.v += SCTP_PAD4(ntohs(pos.p->length)))
438
439#define sctp_walk_errors(err, chunk_hdr)\
440_sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
441
442#define _sctp_walk_errors(err, chunk_hdr, end)\
443for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \
444 sizeof(struct sctp_chunkhdr));\
445 ((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\
446 (void *)chunk_hdr + end) &&\
447 (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
448 ntohs(err->length) >= sizeof(struct sctp_errhdr); \
449 err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length))))
450
451#define sctp_walk_fwdtsn(pos, chunk)\
452_sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
453
454#define _sctp_walk_fwdtsn(pos, chunk, end)\
455for (pos = chunk->subh.fwdtsn_hdr->skip;\
456 (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
457 pos++)
458
459/* External references. */
460
461extern struct proto sctp_prot;
462extern struct proto sctpv6_prot;
463void sctp_put_port(struct sock *sk);
464
465extern struct idr sctp_assocs_id;
466extern spinlock_t sctp_assocs_id_lock;
467
468/* Static inline functions. */
469
470/* Convert from an IP version number to an Address Family symbol. */
471static inline int ipver2af(__u8 ipver)
472{
473 switch (ipver) {
474 case 4:
475 return AF_INET;
476 case 6:
477 return AF_INET6;
478 default:
479 return 0;
480 }
481}
482
483/* Convert from an address parameter type to an address family. */
484static inline int param_type2af(__be16 type)
485{
486 switch (type) {
487 case SCTP_PARAM_IPV4_ADDRESS:
488 return AF_INET;
489 case SCTP_PARAM_IPV6_ADDRESS:
490 return AF_INET6;
491 default:
492 return 0;
493 }
494}
495
496/* Warning: The following hash functions assume a power of two 'size'. */
497/* This is the hash function for the SCTP port hash table. */
498static inline int sctp_phashfn(struct net *net, __u16 lport)
499{
500 return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
501}
502
503/* This is the hash function for the endpoint hash table. */
504static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
505{
506 return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
507}
508
509#define sctp_for_each_hentry(ep, head) \
510 hlist_for_each_entry(ep, head, node)
511
512/* Is a socket of this style? */
513#define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
514static inline int __sctp_style(const struct sock *sk,
515 enum sctp_socket_type style)
516{
517 return sctp_sk(sk)->type == style;
518}
519
520/* Is the association in this state? */
521#define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
522static inline int __sctp_state(const struct sctp_association *asoc,
523 enum sctp_state state)
524{
525 return asoc->state == state;
526}
527
528/* Is the socket in this state? */
529#define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
530static inline int __sctp_sstate(const struct sock *sk,
531 enum sctp_sock_state state)
532{
533 return sk->sk_state == state;
534}
535
536/* Map v4-mapped v6 address back to v4 address */
537static inline void sctp_v6_map_v4(union sctp_addr *addr)
538{
539 addr->v4.sin_family = AF_INET;
540 addr->v4.sin_port = addr->v6.sin6_port;
541 addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
542}
543
544/* Map v4 address to v4-mapped v6 address */
545static inline void sctp_v4_map_v6(union sctp_addr *addr)
546{
547 __be16 port;
548
549 port = addr->v4.sin_port;
550 addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
551 addr->v6.sin6_port = port;
552 addr->v6.sin6_family = AF_INET6;
553 addr->v6.sin6_flowinfo = 0;
554 addr->v6.sin6_scope_id = 0;
555 addr->v6.sin6_addr.s6_addr32[0] = 0;
556 addr->v6.sin6_addr.s6_addr32[1] = 0;
557 addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
558}
559
560/* The cookie is always 0 since this is how it's used in the
561 * pmtu code.
562 */
563static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
564{
565 if (t->dst && !dst_check(t->dst, t->dst_cookie))
566 sctp_transport_dst_release(t);
567
568 return t->dst;
569}
570
571/* Calculate max payload size given a MTU, or the total overhead if
572 * given MTU is zero
573 */
574static inline __u32 __sctp_mtu_payload(const struct sctp_sock *sp,
575 const struct sctp_transport *t,
576 __u32 mtu, __u32 extra)
577{
578 __u32 overhead = sizeof(struct sctphdr) + extra;
579
580 if (sp) {
581 overhead += sp->pf->af->net_header_len;
582 if (sp->udp_port && (!t || t->encap_port))
583 overhead += sizeof(struct udphdr);
584 } else {
585 overhead += sizeof(struct ipv6hdr);
586 }
587
588 if (WARN_ON_ONCE(mtu && mtu <= overhead))
589 mtu = overhead;
590
591 return mtu ? mtu - overhead : overhead;
592}
593
594static inline __u32 sctp_mtu_payload(const struct sctp_sock *sp,
595 __u32 mtu, __u32 extra)
596{
597 return __sctp_mtu_payload(sp, NULL, mtu, extra);
598}
599
600static inline __u32 sctp_dst_mtu(const struct dst_entry *dst)
601{
602 return SCTP_TRUNC4(max_t(__u32, dst_mtu(dst),
603 SCTP_DEFAULT_MINSEGMENT));
604}
605
606static inline bool sctp_transport_pmtu_check(struct sctp_transport *t)
607{
608 __u32 pmtu = sctp_dst_mtu(t->dst);
609
610 if (t->pathmtu == pmtu)
611 return true;
612
613 t->pathmtu = pmtu;
614
615 return false;
616}
617
618static inline __u32 sctp_min_frag_point(struct sctp_sock *sp, __u16 datasize)
619{
620 return sctp_mtu_payload(sp, SCTP_DEFAULT_MINSEGMENT, datasize);
621}
622
623static inline int sctp_transport_pl_hlen(struct sctp_transport *t)
624{
625 return __sctp_mtu_payload(sctp_sk(t->asoc->base.sk), t, 0, 0) -
626 sizeof(struct sctphdr);
627}
628
629static inline void sctp_transport_pl_reset(struct sctp_transport *t)
630{
631 if (t->probe_interval && (t->param_flags & SPP_PMTUD_ENABLE) &&
632 (t->state == SCTP_ACTIVE || t->state == SCTP_UNKNOWN)) {
633 if (t->pl.state == SCTP_PL_DISABLED) {
634 t->pl.state = SCTP_PL_BASE;
635 t->pl.pmtu = SCTP_BASE_PLPMTU;
636 t->pl.probe_size = SCTP_BASE_PLPMTU;
637 sctp_transport_reset_probe_timer(t);
638 }
639 } else {
640 if (t->pl.state != SCTP_PL_DISABLED) {
641 if (del_timer(&t->probe_timer))
642 sctp_transport_put(t);
643 t->pl.state = SCTP_PL_DISABLED;
644 }
645 }
646}
647
648static inline void sctp_transport_pl_update(struct sctp_transport *t)
649{
650 if (t->pl.state == SCTP_PL_DISABLED)
651 return;
652
653 t->pl.state = SCTP_PL_BASE;
654 t->pl.pmtu = SCTP_BASE_PLPMTU;
655 t->pl.probe_size = SCTP_BASE_PLPMTU;
656 sctp_transport_reset_probe_timer(t);
657}
658
659static inline bool sctp_transport_pl_enabled(struct sctp_transport *t)
660{
661 return t->pl.state != SCTP_PL_DISABLED;
662}
663
664static inline bool sctp_newsk_ready(const struct sock *sk)
665{
666 return sock_flag(sk, SOCK_DEAD) || sk->sk_socket;
667}
668
669static inline void sctp_sock_set_nodelay(struct sock *sk)
670{
671 lock_sock(sk);
672 sctp_sk(sk)->nodelay = true;
673 release_sock(sk);
674}
675
676#endif /* __net_sctp_h__ */