xref: /openbmc/linux/include/net/sctp/sctp.h (revision e3b9f1e8)
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  */
97 int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *addr,
98 			      enum sctp_scope, gfp_t gfp, int flags);
99 struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
100 int sctp_register_pf(struct sctp_pf *, sa_family_t);
101 void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
102 
103 /*
104  * sctp/socket.c
105  */
106 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
107 int sctp_inet_listen(struct socket *sock, int backlog);
108 void sctp_write_space(struct sock *sk);
109 void sctp_data_ready(struct sock *sk);
110 __poll_t sctp_poll(struct file *file, struct socket *sock,
111 		poll_table *wait);
112 void sctp_sock_rfree(struct sk_buff *skb);
113 void sctp_copy_sock(struct sock *newsk, struct sock *sk,
114 		    struct sctp_association *asoc);
115 extern struct percpu_counter sctp_sockets_allocated;
116 int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
117 struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);
118 
119 void sctp_transport_walk_start(struct rhashtable_iter *iter);
120 void sctp_transport_walk_stop(struct rhashtable_iter *iter);
121 struct sctp_transport *sctp_transport_get_next(struct net *net,
122 			struct rhashtable_iter *iter);
123 struct sctp_transport *sctp_transport_get_idx(struct net *net,
124 			struct rhashtable_iter *iter, int pos);
125 int sctp_transport_lookup_process(int (*cb)(struct sctp_transport *, void *),
126 				  struct net *net,
127 				  const union sctp_addr *laddr,
128 				  const union sctp_addr *paddr, void *p);
129 int sctp_for_each_transport(int (*cb)(struct sctp_transport *, void *),
130 			    int (*cb_done)(struct sctp_transport *, void *),
131 			    struct net *net, int *pos, void *p);
132 int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p);
133 int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc,
134 		       struct sctp_info *info);
135 
136 /*
137  * sctp/primitive.c
138  */
139 int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
140 int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
141 int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
142 int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
143 int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
144 int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
145 int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
146 			  void *arg);
147 
148 /*
149  * sctp/input.c
150  */
151 int sctp_rcv(struct sk_buff *skb);
152 void sctp_v4_err(struct sk_buff *skb, u32 info);
153 void sctp_hash_endpoint(struct sctp_endpoint *);
154 void sctp_unhash_endpoint(struct sctp_endpoint *);
155 struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
156 			     struct sctphdr *, struct sctp_association **,
157 			     struct sctp_transport **);
158 void sctp_err_finish(struct sock *, struct sctp_transport *);
159 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
160 			   struct sctp_transport *t, __u32 pmtu);
161 void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
162 			struct sk_buff *);
163 void sctp_icmp_proto_unreachable(struct sock *sk,
164 				 struct sctp_association *asoc,
165 				 struct sctp_transport *t);
166 void sctp_backlog_migrate(struct sctp_association *assoc,
167 			  struct sock *oldsk, struct sock *newsk);
168 int sctp_transport_hashtable_init(void);
169 void sctp_transport_hashtable_destroy(void);
170 int sctp_hash_transport(struct sctp_transport *t);
171 void sctp_unhash_transport(struct sctp_transport *t);
172 struct sctp_transport *sctp_addrs_lookup_transport(
173 				struct net *net,
174 				const union sctp_addr *laddr,
175 				const union sctp_addr *paddr);
176 struct sctp_transport *sctp_epaddr_lookup_transport(
177 				const struct sctp_endpoint *ep,
178 				const union sctp_addr *paddr);
179 
180 /*
181  * sctp/proc.c
182  */
183 int sctp_snmp_proc_init(struct net *net);
184 void sctp_snmp_proc_exit(struct net *net);
185 int sctp_eps_proc_init(struct net *net);
186 void sctp_eps_proc_exit(struct net *net);
187 int sctp_assocs_proc_init(struct net *net);
188 void sctp_assocs_proc_exit(struct net *net);
189 int sctp_remaddr_proc_init(struct net *net);
190 void sctp_remaddr_proc_exit(struct net *net);
191 
192 /*
193  * sctp/offload.c
194  */
195 int sctp_offload_init(void);
196 
197 /*
198  * sctp/stream_sched.c
199  */
200 void sctp_sched_ops_init(void);
201 
202 /*
203  * sctp/stream.c
204  */
205 int sctp_send_reset_streams(struct sctp_association *asoc,
206 			    struct sctp_reset_streams *params);
207 int sctp_send_reset_assoc(struct sctp_association *asoc);
208 int sctp_send_add_streams(struct sctp_association *asoc,
209 			  struct sctp_add_streams *params);
210 
211 /*
212  * Module global variables
213  */
214 
215  /*
216   * sctp/protocol.c
217   */
218 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
219 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
220 extern long sysctl_sctp_mem[3];
221 extern int sysctl_sctp_rmem[3];
222 extern int sysctl_sctp_wmem[3];
223 
224 /*
225  *  Section:  Macros, externs, and inlines
226  */
227 
228 /* SCTP SNMP MIB stats handlers */
229 #define SCTP_INC_STATS(net, field)	SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
230 #define __SCTP_INC_STATS(net, field)	__SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
231 #define SCTP_DEC_STATS(net, field)	SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
232 
233 /* sctp mib definitions */
234 enum {
235 	SCTP_MIB_NUM = 0,
236 	SCTP_MIB_CURRESTAB,			/* CurrEstab */
237 	SCTP_MIB_ACTIVEESTABS,			/* ActiveEstabs */
238 	SCTP_MIB_PASSIVEESTABS,			/* PassiveEstabs */
239 	SCTP_MIB_ABORTEDS,			/* Aborteds */
240 	SCTP_MIB_SHUTDOWNS,			/* Shutdowns */
241 	SCTP_MIB_OUTOFBLUES,			/* OutOfBlues */
242 	SCTP_MIB_CHECKSUMERRORS,		/* ChecksumErrors */
243 	SCTP_MIB_OUTCTRLCHUNKS,			/* OutCtrlChunks */
244 	SCTP_MIB_OUTORDERCHUNKS,		/* OutOrderChunks */
245 	SCTP_MIB_OUTUNORDERCHUNKS,		/* OutUnorderChunks */
246 	SCTP_MIB_INCTRLCHUNKS,			/* InCtrlChunks */
247 	SCTP_MIB_INORDERCHUNKS,			/* InOrderChunks */
248 	SCTP_MIB_INUNORDERCHUNKS,		/* InUnorderChunks */
249 	SCTP_MIB_FRAGUSRMSGS,			/* FragUsrMsgs */
250 	SCTP_MIB_REASMUSRMSGS,			/* ReasmUsrMsgs */
251 	SCTP_MIB_OUTSCTPPACKS,			/* OutSCTPPacks */
252 	SCTP_MIB_INSCTPPACKS,			/* InSCTPPacks */
253 	SCTP_MIB_T1_INIT_EXPIREDS,
254 	SCTP_MIB_T1_COOKIE_EXPIREDS,
255 	SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
256 	SCTP_MIB_T3_RTX_EXPIREDS,
257 	SCTP_MIB_T4_RTO_EXPIREDS,
258 	SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
259 	SCTP_MIB_DELAY_SACK_EXPIREDS,
260 	SCTP_MIB_AUTOCLOSE_EXPIREDS,
261 	SCTP_MIB_T1_RETRANSMITS,
262 	SCTP_MIB_T3_RETRANSMITS,
263 	SCTP_MIB_PMTUD_RETRANSMITS,
264 	SCTP_MIB_FAST_RETRANSMITS,
265 	SCTP_MIB_IN_PKT_SOFTIRQ,
266 	SCTP_MIB_IN_PKT_BACKLOG,
267 	SCTP_MIB_IN_PKT_DISCARDS,
268 	SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
269 	__SCTP_MIB_MAX
270 };
271 
272 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
273 struct sctp_mib {
274         unsigned long   mibs[SCTP_MIB_MAX];
275 };
276 
277 /* helper function to track stats about max rto and related transport */
278 static inline void sctp_max_rto(struct sctp_association *asoc,
279 				struct sctp_transport *trans)
280 {
281 	if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
282 		asoc->stats.max_obs_rto = trans->rto;
283 		memset(&asoc->stats.obs_rto_ipaddr, 0,
284 			sizeof(struct sockaddr_storage));
285 		memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
286 			trans->af_specific->sockaddr_len);
287 	}
288 }
289 
290 /*
291  * Macros for keeping a global reference of object allocations.
292  */
293 #ifdef CONFIG_SCTP_DBG_OBJCNT
294 
295 extern atomic_t sctp_dbg_objcnt_sock;
296 extern atomic_t sctp_dbg_objcnt_ep;
297 extern atomic_t sctp_dbg_objcnt_assoc;
298 extern atomic_t sctp_dbg_objcnt_transport;
299 extern atomic_t sctp_dbg_objcnt_chunk;
300 extern atomic_t sctp_dbg_objcnt_bind_addr;
301 extern atomic_t sctp_dbg_objcnt_bind_bucket;
302 extern atomic_t sctp_dbg_objcnt_addr;
303 extern atomic_t sctp_dbg_objcnt_datamsg;
304 extern atomic_t sctp_dbg_objcnt_keys;
305 
306 /* Macros to atomically increment/decrement objcnt counters.  */
307 #define SCTP_DBG_OBJCNT_INC(name) \
308 atomic_inc(&sctp_dbg_objcnt_## name)
309 #define SCTP_DBG_OBJCNT_DEC(name) \
310 atomic_dec(&sctp_dbg_objcnt_## name)
311 #define SCTP_DBG_OBJCNT(name) \
312 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
313 
314 /* Macro to help create new entries in in the global array of
315  * objcnt counters.
316  */
317 #define SCTP_DBG_OBJCNT_ENTRY(name) \
318 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
319 
320 void sctp_dbg_objcnt_init(struct net *);
321 void sctp_dbg_objcnt_exit(struct net *);
322 
323 #else
324 
325 #define SCTP_DBG_OBJCNT_INC(name)
326 #define SCTP_DBG_OBJCNT_DEC(name)
327 
328 static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
329 static inline void sctp_dbg_objcnt_exit(struct net *net) { return; }
330 
331 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
332 
333 #if defined CONFIG_SYSCTL
334 void sctp_sysctl_register(void);
335 void sctp_sysctl_unregister(void);
336 int sctp_sysctl_net_register(struct net *net);
337 void sctp_sysctl_net_unregister(struct net *net);
338 #else
339 static inline void sctp_sysctl_register(void) { return; }
340 static inline void sctp_sysctl_unregister(void) { return; }
341 static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
342 static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
343 #endif
344 
345 /* Size of Supported Address Parameter for 'x' address types. */
346 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
347 
348 #if IS_ENABLED(CONFIG_IPV6)
349 
350 void sctp_v6_pf_init(void);
351 void sctp_v6_pf_exit(void);
352 int sctp_v6_protosw_init(void);
353 void sctp_v6_protosw_exit(void);
354 int sctp_v6_add_protocol(void);
355 void sctp_v6_del_protocol(void);
356 
357 #else /* #ifdef defined(CONFIG_IPV6) */
358 
359 static inline void sctp_v6_pf_init(void) { return; }
360 static inline void sctp_v6_pf_exit(void) { return; }
361 static inline int sctp_v6_protosw_init(void) { return 0; }
362 static inline void sctp_v6_protosw_exit(void) { return; }
363 static inline int sctp_v6_add_protocol(void) { return 0; }
364 static inline void sctp_v6_del_protocol(void) { return; }
365 
366 #endif /* #if defined(CONFIG_IPV6) */
367 
368 
369 /* Map an association to an assoc_id. */
370 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
371 {
372 	return asoc ? asoc->assoc_id : 0;
373 }
374 
375 static inline enum sctp_sstat_state
376 sctp_assoc_to_state(const struct sctp_association *asoc)
377 {
378 	/* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
379 	 * got rid of it in kernel space. Therefore SCTP_CLOSED et al
380 	 * start at =1 in user space, but actually as =0 in kernel space.
381 	 * Now that we can not break user space and SCTP_EMPTY is exposed
382 	 * there, we need to fix it up with an ugly offset not to break
383 	 * applications. :(
384 	 */
385 	return asoc->state + 1;
386 }
387 
388 /* Look up the association by its id.  */
389 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
390 
391 int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
392 
393 /* A macro to walk a list of skbs.  */
394 #define sctp_skb_for_each(pos, head, tmp) \
395 	skb_queue_walk_safe(head, pos, tmp)
396 
397 /**
398  *	sctp_list_dequeue - remove from the head of the queue
399  *	@list: list to dequeue from
400  *
401  *	Remove the head of the list. The head item is
402  *	returned or %NULL if the list is empty.
403  */
404 
405 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
406 {
407 	struct list_head *result = NULL;
408 
409 	if (!list_empty(list)) {
410 		result = list->next;
411 		list_del_init(result);
412 	}
413 	return result;
414 }
415 
416 /* SCTP version of skb_set_owner_r.  We need this one because
417  * of the way we have to do receive buffer accounting on bundled
418  * chunks.
419  */
420 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
421 {
422 	struct sctp_ulpevent *event = sctp_skb2event(skb);
423 
424 	skb_orphan(skb);
425 	skb->sk = sk;
426 	skb->destructor = sctp_sock_rfree;
427 	atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
428 	/*
429 	 * This mimics the behavior of skb_set_owner_r
430 	 */
431 	sk->sk_forward_alloc -= event->rmem_len;
432 }
433 
434 /* Tests if the list has one and only one entry. */
435 static inline int sctp_list_single_entry(struct list_head *head)
436 {
437 	return (head->next != head) && (head->next == head->prev);
438 }
439 
440 /* Break down data chunks at this point.  */
441 static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
442 {
443 	struct sctp_sock *sp = sctp_sk(asoc->base.sk);
444 	int frag = pmtu;
445 
446 	frag -= sp->pf->af->net_header_len;
447 	frag -= sizeof(struct sctphdr) + sctp_datachk_len(&asoc->stream);
448 
449 	if (asoc->user_frag)
450 		frag = min_t(int, frag, asoc->user_frag);
451 
452 	frag = SCTP_TRUNC4(min_t(int, frag, SCTP_MAX_CHUNK_LEN -
453 					    sctp_datachk_len(&asoc->stream)));
454 
455 	return frag;
456 }
457 
458 static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc)
459 {
460 	sctp_assoc_sync_pmtu(asoc);
461 	asoc->pmtu_pending = 0;
462 }
463 
464 static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
465 {
466 	return !list_empty(&chunk->list);
467 }
468 
469 /* Walk through a list of TLV parameters.  Don't trust the
470  * individual parameter lengths and instead depend on
471  * the chunk length to indicate when to stop.  Make sure
472  * there is room for a param header too.
473  */
474 #define sctp_walk_params(pos, chunk, member)\
475 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
476 
477 #define _sctp_walk_params(pos, chunk, end, member)\
478 for (pos.v = chunk->member;\
479      (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\
480       (void *)chunk + end) &&\
481      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
482      ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\
483      pos.v += SCTP_PAD4(ntohs(pos.p->length)))
484 
485 #define sctp_walk_errors(err, chunk_hdr)\
486 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
487 
488 #define _sctp_walk_errors(err, chunk_hdr, end)\
489 for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \
490 	    sizeof(struct sctp_chunkhdr));\
491      ((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\
492       (void *)chunk_hdr + end) &&\
493      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
494      ntohs(err->length) >= sizeof(struct sctp_errhdr); \
495      err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length))))
496 
497 #define sctp_walk_fwdtsn(pos, chunk)\
498 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
499 
500 #define _sctp_walk_fwdtsn(pos, chunk, end)\
501 for (pos = chunk->subh.fwdtsn_hdr->skip;\
502      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
503      pos++)
504 
505 /* External references. */
506 
507 extern struct proto sctp_prot;
508 extern struct proto sctpv6_prot;
509 void sctp_put_port(struct sock *sk);
510 
511 extern struct idr sctp_assocs_id;
512 extern spinlock_t sctp_assocs_id_lock;
513 
514 /* Static inline functions. */
515 
516 /* Convert from an IP version number to an Address Family symbol.  */
517 static inline int ipver2af(__u8 ipver)
518 {
519 	switch (ipver) {
520 	case 4:
521 	        return  AF_INET;
522 	case 6:
523 		return AF_INET6;
524 	default:
525 		return 0;
526 	}
527 }
528 
529 /* Convert from an address parameter type to an address family.  */
530 static inline int param_type2af(__be16 type)
531 {
532 	switch (type) {
533 	case SCTP_PARAM_IPV4_ADDRESS:
534 	        return  AF_INET;
535 	case SCTP_PARAM_IPV6_ADDRESS:
536 		return AF_INET6;
537 	default:
538 		return 0;
539 	}
540 }
541 
542 /* Warning: The following hash functions assume a power of two 'size'. */
543 /* This is the hash function for the SCTP port hash table. */
544 static inline int sctp_phashfn(struct net *net, __u16 lport)
545 {
546 	return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
547 }
548 
549 /* This is the hash function for the endpoint hash table. */
550 static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
551 {
552 	return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
553 }
554 
555 #define sctp_for_each_hentry(epb, head) \
556 	hlist_for_each_entry(epb, head, node)
557 
558 /* Is a socket of this style? */
559 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
560 static inline int __sctp_style(const struct sock *sk,
561 			       enum sctp_socket_type style)
562 {
563 	return sctp_sk(sk)->type == style;
564 }
565 
566 /* Is the association in this state? */
567 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
568 static inline int __sctp_state(const struct sctp_association *asoc,
569 			       enum sctp_state state)
570 {
571 	return asoc->state == state;
572 }
573 
574 /* Is the socket in this state? */
575 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
576 static inline int __sctp_sstate(const struct sock *sk,
577 				enum sctp_sock_state state)
578 {
579 	return sk->sk_state == state;
580 }
581 
582 /* Map v4-mapped v6 address back to v4 address */
583 static inline void sctp_v6_map_v4(union sctp_addr *addr)
584 {
585 	addr->v4.sin_family = AF_INET;
586 	addr->v4.sin_port = addr->v6.sin6_port;
587 	addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
588 }
589 
590 /* Map v4 address to v4-mapped v6 address */
591 static inline void sctp_v4_map_v6(union sctp_addr *addr)
592 {
593 	__be16 port;
594 
595 	port = addr->v4.sin_port;
596 	addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
597 	addr->v6.sin6_port = port;
598 	addr->v6.sin6_family = AF_INET6;
599 	addr->v6.sin6_flowinfo = 0;
600 	addr->v6.sin6_scope_id = 0;
601 	addr->v6.sin6_addr.s6_addr32[0] = 0;
602 	addr->v6.sin6_addr.s6_addr32[1] = 0;
603 	addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
604 }
605 
606 /* The cookie is always 0 since this is how it's used in the
607  * pmtu code.
608  */
609 static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
610 {
611 	if (t->dst && !dst_check(t->dst, t->dst_cookie))
612 		sctp_transport_dst_release(t);
613 
614 	return t->dst;
615 }
616 
617 static inline bool sctp_transport_pmtu_check(struct sctp_transport *t)
618 {
619 	__u32 pmtu = max_t(size_t, SCTP_TRUNC4(dst_mtu(t->dst)),
620 			   SCTP_DEFAULT_MINSEGMENT);
621 
622 	if (t->pathmtu == pmtu)
623 		return true;
624 
625 	t->pathmtu = pmtu;
626 
627 	return false;
628 }
629 
630 #endif /* __net_sctp_h__ */
631