Linux Audio

Check our new training course

Loading...
v4.17
 
  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__ */
v5.14.15
  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);
 87int sctp_udp_sock_start(struct net *net);
 88void sctp_udp_sock_stop(struct net *net);
 89
 90/*
 91 * sctp/socket.c
 92 */
 93int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr,
 94		      int addr_len, int flags);
 95int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 96int sctp_inet_listen(struct socket *sock, int backlog);
 97void sctp_write_space(struct sock *sk);
 98void sctp_data_ready(struct sock *sk);
 99__poll_t sctp_poll(struct file *file, struct socket *sock,
100		poll_table *wait);
101void sctp_sock_rfree(struct sk_buff *skb);
102void sctp_copy_sock(struct sock *newsk, struct sock *sk,
103		    struct sctp_association *asoc);
104extern struct percpu_counter sctp_sockets_allocated;
105int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
106struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);
107
108void sctp_transport_walk_start(struct rhashtable_iter *iter);
109void sctp_transport_walk_stop(struct rhashtable_iter *iter);
110struct sctp_transport *sctp_transport_get_next(struct net *net,
111			struct rhashtable_iter *iter);
112struct sctp_transport *sctp_transport_get_idx(struct net *net,
113			struct rhashtable_iter *iter, int pos);
114int sctp_transport_lookup_process(int (*cb)(struct sctp_transport *, void *),
115				  struct net *net,
116				  const union sctp_addr *laddr,
117				  const union sctp_addr *paddr, void *p);
118int sctp_for_each_transport(int (*cb)(struct sctp_transport *, void *),
119			    int (*cb_done)(struct sctp_transport *, void *),
120			    struct net *net, int *pos, void *p);
121int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p);
122int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc,
123		       struct sctp_info *info);
124
125/*
126 * sctp/primitive.c
127 */
128int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
129int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
130int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
131int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
132int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
133int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
134int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
135			  void *arg);
136
137/*
138 * sctp/input.c
139 */
140int sctp_rcv(struct sk_buff *skb);
141int sctp_v4_err(struct sk_buff *skb, u32 info);
142int sctp_hash_endpoint(struct sctp_endpoint *ep);
143void sctp_unhash_endpoint(struct sctp_endpoint *);
144struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
145			     struct sctphdr *, struct sctp_association **,
146			     struct sctp_transport **);
147void sctp_err_finish(struct sock *, struct sctp_transport *);
148int sctp_udp_v4_err(struct sock *sk, struct sk_buff *skb);
149int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb);
150void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
151			   struct sctp_transport *t, __u32 pmtu);
152void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
153			struct sk_buff *);
154void sctp_icmp_proto_unreachable(struct sock *sk,
155				 struct sctp_association *asoc,
156				 struct sctp_transport *t);
157void sctp_backlog_migrate(struct sctp_association *assoc,
158			  struct sock *oldsk, struct sock *newsk);
159int sctp_transport_hashtable_init(void);
160void sctp_transport_hashtable_destroy(void);
161int sctp_hash_transport(struct sctp_transport *t);
162void sctp_unhash_transport(struct sctp_transport *t);
163struct sctp_transport *sctp_addrs_lookup_transport(
164				struct net *net,
165				const union sctp_addr *laddr,
166				const union sctp_addr *paddr);
167struct sctp_transport *sctp_epaddr_lookup_transport(
168				const struct sctp_endpoint *ep,
169				const union sctp_addr *paddr);
170
171/*
172 * sctp/proc.c
173 */
174int __net_init sctp_proc_init(struct net *net);
175
176/*
177 * sctp/offload.c
178 */
179int sctp_offload_init(void);
180
181/*
182 * sctp/stream_sched.c
183 */
184void sctp_sched_ops_init(void);
185
186/*
187 * sctp/stream.c
188 */
189int sctp_send_reset_streams(struct sctp_association *asoc,
190			    struct sctp_reset_streams *params);
191int sctp_send_reset_assoc(struct sctp_association *asoc);
192int sctp_send_add_streams(struct sctp_association *asoc,
193			  struct sctp_add_streams *params);
194
195/*
196 * Module global variables
197 */
198
199 /*
200  * sctp/protocol.c
201  */
202extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
203extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
204extern long sysctl_sctp_mem[3];
205extern int sysctl_sctp_rmem[3];
206extern int sysctl_sctp_wmem[3];
207
208/*
209 *  Section:  Macros, externs, and inlines
210 */
211
212/* SCTP SNMP MIB stats handlers */
213#define SCTP_INC_STATS(net, field)	SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
214#define __SCTP_INC_STATS(net, field)	__SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
215#define SCTP_DEC_STATS(net, field)	SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
216
217/* sctp mib definitions */
218enum {
219	SCTP_MIB_NUM = 0,
220	SCTP_MIB_CURRESTAB,			/* CurrEstab */
221	SCTP_MIB_ACTIVEESTABS,			/* ActiveEstabs */
222	SCTP_MIB_PASSIVEESTABS,			/* PassiveEstabs */
223	SCTP_MIB_ABORTEDS,			/* Aborteds */
224	SCTP_MIB_SHUTDOWNS,			/* Shutdowns */
225	SCTP_MIB_OUTOFBLUES,			/* OutOfBlues */
226	SCTP_MIB_CHECKSUMERRORS,		/* ChecksumErrors */
227	SCTP_MIB_OUTCTRLCHUNKS,			/* OutCtrlChunks */
228	SCTP_MIB_OUTORDERCHUNKS,		/* OutOrderChunks */
229	SCTP_MIB_OUTUNORDERCHUNKS,		/* OutUnorderChunks */
230	SCTP_MIB_INCTRLCHUNKS,			/* InCtrlChunks */
231	SCTP_MIB_INORDERCHUNKS,			/* InOrderChunks */
232	SCTP_MIB_INUNORDERCHUNKS,		/* InUnorderChunks */
233	SCTP_MIB_FRAGUSRMSGS,			/* FragUsrMsgs */
234	SCTP_MIB_REASMUSRMSGS,			/* ReasmUsrMsgs */
235	SCTP_MIB_OUTSCTPPACKS,			/* OutSCTPPacks */
236	SCTP_MIB_INSCTPPACKS,			/* InSCTPPacks */
237	SCTP_MIB_T1_INIT_EXPIREDS,
238	SCTP_MIB_T1_COOKIE_EXPIREDS,
239	SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
240	SCTP_MIB_T3_RTX_EXPIREDS,
241	SCTP_MIB_T4_RTO_EXPIREDS,
242	SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
243	SCTP_MIB_DELAY_SACK_EXPIREDS,
244	SCTP_MIB_AUTOCLOSE_EXPIREDS,
245	SCTP_MIB_T1_RETRANSMITS,
246	SCTP_MIB_T3_RETRANSMITS,
247	SCTP_MIB_PMTUD_RETRANSMITS,
248	SCTP_MIB_FAST_RETRANSMITS,
249	SCTP_MIB_IN_PKT_SOFTIRQ,
250	SCTP_MIB_IN_PKT_BACKLOG,
251	SCTP_MIB_IN_PKT_DISCARDS,
252	SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
253	__SCTP_MIB_MAX
254};
255
256#define SCTP_MIB_MAX    __SCTP_MIB_MAX
257struct sctp_mib {
258        unsigned long   mibs[SCTP_MIB_MAX];
259};
260
261/* helper function to track stats about max rto and related transport */
262static inline void sctp_max_rto(struct sctp_association *asoc,
263				struct sctp_transport *trans)
264{
265	if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
266		asoc->stats.max_obs_rto = trans->rto;
267		memset(&asoc->stats.obs_rto_ipaddr, 0,
268			sizeof(struct sockaddr_storage));
269		memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
270			trans->af_specific->sockaddr_len);
271	}
272}
273
274/*
275 * Macros for keeping a global reference of object allocations.
276 */
277#ifdef CONFIG_SCTP_DBG_OBJCNT
278
279extern atomic_t sctp_dbg_objcnt_sock;
280extern atomic_t sctp_dbg_objcnt_ep;
281extern atomic_t sctp_dbg_objcnt_assoc;
282extern atomic_t sctp_dbg_objcnt_transport;
283extern atomic_t sctp_dbg_objcnt_chunk;
284extern atomic_t sctp_dbg_objcnt_bind_addr;
285extern atomic_t sctp_dbg_objcnt_bind_bucket;
286extern atomic_t sctp_dbg_objcnt_addr;
287extern atomic_t sctp_dbg_objcnt_datamsg;
288extern atomic_t sctp_dbg_objcnt_keys;
289
290/* Macros to atomically increment/decrement objcnt counters.  */
291#define SCTP_DBG_OBJCNT_INC(name) \
292atomic_inc(&sctp_dbg_objcnt_## name)
293#define SCTP_DBG_OBJCNT_DEC(name) \
294atomic_dec(&sctp_dbg_objcnt_## name)
295#define SCTP_DBG_OBJCNT(name) \
296atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
297
298/* Macro to help create new entries in the global array of
299 * objcnt counters.
300 */
301#define SCTP_DBG_OBJCNT_ENTRY(name) \
302{.label= #name, .counter= &sctp_dbg_objcnt_## name}
303
304void sctp_dbg_objcnt_init(struct net *);
305
306#else
307
308#define SCTP_DBG_OBJCNT_INC(name)
309#define SCTP_DBG_OBJCNT_DEC(name)
310
311static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
312
313#endif /* CONFIG_SCTP_DBG_OBJCOUNT */
314
315#if defined CONFIG_SYSCTL
316void sctp_sysctl_register(void);
317void sctp_sysctl_unregister(void);
318int sctp_sysctl_net_register(struct net *net);
319void sctp_sysctl_net_unregister(struct net *net);
320#else
321static inline void sctp_sysctl_register(void) { return; }
322static inline void sctp_sysctl_unregister(void) { return; }
323static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
324static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
325#endif
326
327/* Size of Supported Address Parameter for 'x' address types. */
328#define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
329
330#if IS_ENABLED(CONFIG_IPV6)
331
332void sctp_v6_pf_init(void);
333void sctp_v6_pf_exit(void);
334int sctp_v6_protosw_init(void);
335void sctp_v6_protosw_exit(void);
336int sctp_v6_add_protocol(void);
337void sctp_v6_del_protocol(void);
338
339#else /* #ifdef defined(CONFIG_IPV6) */
340
341static inline void sctp_v6_pf_init(void) { return; }
342static inline void sctp_v6_pf_exit(void) { return; }
343static inline int sctp_v6_protosw_init(void) { return 0; }
344static inline void sctp_v6_protosw_exit(void) { return; }
345static inline int sctp_v6_add_protocol(void) { return 0; }
346static inline void sctp_v6_del_protocol(void) { return; }
347
348#endif /* #if defined(CONFIG_IPV6) */
349
350
351/* Map an association to an assoc_id. */
352static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
353{
354	return asoc ? asoc->assoc_id : 0;
355}
356
357static inline enum sctp_sstat_state
358sctp_assoc_to_state(const struct sctp_association *asoc)
359{
360	/* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
361	 * got rid of it in kernel space. Therefore SCTP_CLOSED et al
362	 * start at =1 in user space, but actually as =0 in kernel space.
363	 * Now that we can not break user space and SCTP_EMPTY is exposed
364	 * there, we need to fix it up with an ugly offset not to break
365	 * applications. :(
366	 */
367	return asoc->state + 1;
368}
369
370/* Look up the association by its id.  */
371struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
372
373int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
374
375/* A macro to walk a list of skbs.  */
376#define sctp_skb_for_each(pos, head, tmp) \
377	skb_queue_walk_safe(head, pos, tmp)
378
379/**
380 *	sctp_list_dequeue - remove from the head of the queue
381 *	@list: list to dequeue from
382 *
383 *	Remove the head of the list. The head item is
384 *	returned or %NULL if the list is empty.
385 */
386
387static inline struct list_head *sctp_list_dequeue(struct list_head *list)
388{
389	struct list_head *result = NULL;
390
391	if (!list_empty(list)) {
392		result = list->next;
393		list_del_init(result);
394	}
395	return result;
396}
397
398/* SCTP version of skb_set_owner_r.  We need this one because
399 * of the way we have to do receive buffer accounting on bundled
400 * chunks.
401 */
402static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
403{
404	struct sctp_ulpevent *event = sctp_skb2event(skb);
405
406	skb_orphan(skb);
407	skb->sk = sk;
408	skb->destructor = sctp_sock_rfree;
409	atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
410	/*
411	 * This mimics the behavior of skb_set_owner_r
412	 */
413	sk_mem_charge(sk, event->rmem_len);
414}
415
416/* Tests if the list has one and only one entry. */
417static inline int sctp_list_single_entry(struct list_head *head)
418{
419	return list_is_singular(head);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
420}
421
422static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
423{
424	return !list_empty(&chunk->list);
425}
426
427/* Walk through a list of TLV parameters.  Don't trust the
428 * individual parameter lengths and instead depend on
429 * the chunk length to indicate when to stop.  Make sure
430 * there is room for a param header too.
431 */
432#define sctp_walk_params(pos, chunk, member)\
433_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
434
435#define _sctp_walk_params(pos, chunk, end, member)\
436for (pos.v = chunk->member;\
437     (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\
438      (void *)chunk + end) &&\
439     pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
440     ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\
441     pos.v += SCTP_PAD4(ntohs(pos.p->length)))
442
443#define sctp_walk_errors(err, chunk_hdr)\
444_sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
445
446#define _sctp_walk_errors(err, chunk_hdr, end)\
447for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \
448	    sizeof(struct sctp_chunkhdr));\
449     ((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\
450      (void *)chunk_hdr + end) &&\
451     (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
452     ntohs(err->length) >= sizeof(struct sctp_errhdr); \
453     err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length))))
454
455#define sctp_walk_fwdtsn(pos, chunk)\
456_sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
457
458#define _sctp_walk_fwdtsn(pos, chunk, end)\
459for (pos = chunk->subh.fwdtsn_hdr->skip;\
460     (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
461     pos++)
462
463/* External references. */
464
465extern struct proto sctp_prot;
466extern struct proto sctpv6_prot;
467void sctp_put_port(struct sock *sk);
468
469extern struct idr sctp_assocs_id;
470extern spinlock_t sctp_assocs_id_lock;
471
472/* Static inline functions. */
473
474/* Convert from an IP version number to an Address Family symbol.  */
475static inline int ipver2af(__u8 ipver)
476{
477	switch (ipver) {
478	case 4:
479	        return  AF_INET;
480	case 6:
481		return AF_INET6;
482	default:
483		return 0;
484	}
485}
486
487/* Convert from an address parameter type to an address family.  */
488static inline int param_type2af(__be16 type)
489{
490	switch (type) {
491	case SCTP_PARAM_IPV4_ADDRESS:
492	        return  AF_INET;
493	case SCTP_PARAM_IPV6_ADDRESS:
494		return AF_INET6;
495	default:
496		return 0;
497	}
498}
499
500/* Warning: The following hash functions assume a power of two 'size'. */
501/* This is the hash function for the SCTP port hash table. */
502static inline int sctp_phashfn(struct net *net, __u16 lport)
503{
504	return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
505}
506
507/* This is the hash function for the endpoint hash table. */
508static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
509{
510	return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
511}
512
513#define sctp_for_each_hentry(epb, head) \
514	hlist_for_each_entry(epb, head, node)
515
516/* Is a socket of this style? */
517#define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
518static inline int __sctp_style(const struct sock *sk,
519			       enum sctp_socket_type style)
520{
521	return sctp_sk(sk)->type == style;
522}
523
524/* Is the association in this state? */
525#define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
526static inline int __sctp_state(const struct sctp_association *asoc,
527			       enum sctp_state state)
528{
529	return asoc->state == state;
530}
531
532/* Is the socket in this state? */
533#define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
534static inline int __sctp_sstate(const struct sock *sk,
535				enum sctp_sock_state state)
536{
537	return sk->sk_state == state;
538}
539
540/* Map v4-mapped v6 address back to v4 address */
541static inline void sctp_v6_map_v4(union sctp_addr *addr)
542{
543	addr->v4.sin_family = AF_INET;
544	addr->v4.sin_port = addr->v6.sin6_port;
545	addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
546}
547
548/* Map v4 address to v4-mapped v6 address */
549static inline void sctp_v4_map_v6(union sctp_addr *addr)
550{
551	__be16 port;
552
553	port = addr->v4.sin_port;
554	addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
555	addr->v6.sin6_port = port;
556	addr->v6.sin6_family = AF_INET6;
557	addr->v6.sin6_flowinfo = 0;
558	addr->v6.sin6_scope_id = 0;
559	addr->v6.sin6_addr.s6_addr32[0] = 0;
560	addr->v6.sin6_addr.s6_addr32[1] = 0;
561	addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
562}
563
564/* The cookie is always 0 since this is how it's used in the
565 * pmtu code.
566 */
567static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
568{
569	if (t->dst && !dst_check(t->dst, t->dst_cookie))
570		sctp_transport_dst_release(t);
571
572	return t->dst;
573}
574
575/* Calculate max payload size given a MTU, or the total overhead if
576 * given MTU is zero
577 */
578static inline __u32 __sctp_mtu_payload(const struct sctp_sock *sp,
579				       const struct sctp_transport *t,
580				       __u32 mtu, __u32 extra)
581{
582	__u32 overhead = sizeof(struct sctphdr) + extra;
583
584	if (sp) {
585		overhead += sp->pf->af->net_header_len;
586		if (sp->udp_port && (!t || t->encap_port))
587			overhead += sizeof(struct udphdr);
588	} else {
589		overhead += sizeof(struct ipv6hdr);
590	}
591
592	if (WARN_ON_ONCE(mtu && mtu <= overhead))
593		mtu = overhead;
594
595	return mtu ? mtu - overhead : overhead;
596}
597
598static inline __u32 sctp_mtu_payload(const struct sctp_sock *sp,
599				     __u32 mtu, __u32 extra)
600{
601	return __sctp_mtu_payload(sp, NULL, mtu, extra);
602}
603
604static inline __u32 sctp_dst_mtu(const struct dst_entry *dst)
605{
606	return SCTP_TRUNC4(max_t(__u32, dst_mtu(dst),
607				 SCTP_DEFAULT_MINSEGMENT));
608}
609
610static inline bool sctp_transport_pmtu_check(struct sctp_transport *t)
611{
612	__u32 pmtu = sctp_dst_mtu(t->dst);
 
613
614	if (t->pathmtu == pmtu)
615		return true;
616
617	t->pathmtu = pmtu;
618
619	return false;
620}
621
622static inline __u32 sctp_min_frag_point(struct sctp_sock *sp, __u16 datasize)
623{
624	return sctp_mtu_payload(sp, SCTP_DEFAULT_MINSEGMENT, datasize);
625}
626
627static inline int sctp_transport_pl_hlen(struct sctp_transport *t)
628{
629	return __sctp_mtu_payload(sctp_sk(t->asoc->base.sk), t, 0, 0);
630}
631
632static inline void sctp_transport_pl_reset(struct sctp_transport *t)
633{
634	if (t->probe_interval && (t->param_flags & SPP_PMTUD_ENABLE) &&
635	    (t->state == SCTP_ACTIVE || t->state == SCTP_UNKNOWN)) {
636		if (t->pl.state == SCTP_PL_DISABLED) {
637			t->pl.state = SCTP_PL_BASE;
638			t->pl.pmtu = SCTP_BASE_PLPMTU;
639			t->pl.probe_size = SCTP_BASE_PLPMTU;
640			sctp_transport_reset_probe_timer(t);
641		}
642	} else {
643		if (t->pl.state != SCTP_PL_DISABLED) {
644			if (del_timer(&t->probe_timer))
645				sctp_transport_put(t);
646			t->pl.state = SCTP_PL_DISABLED;
647		}
648	}
649}
650
651static inline void sctp_transport_pl_update(struct sctp_transport *t)
652{
653	if (t->pl.state == SCTP_PL_DISABLED)
654		return;
655
656	if (del_timer(&t->probe_timer))
657		sctp_transport_put(t);
658
659	t->pl.state = SCTP_PL_BASE;
660	t->pl.pmtu = SCTP_BASE_PLPMTU;
661	t->pl.probe_size = SCTP_BASE_PLPMTU;
662}
663
664static inline bool sctp_transport_pl_enabled(struct sctp_transport *t)
665{
666	return t->pl.state != SCTP_PL_DISABLED;
667}
668
669static inline bool sctp_newsk_ready(const struct sock *sk)
670{
671	return sock_flag(sk, SOCK_DEAD) || sk->sk_socket;
672}
673
674static inline void sctp_sock_set_nodelay(struct sock *sk)
675{
676	lock_sock(sk);
677	sctp_sk(sk)->nodelay = true;
678	release_sock(sk);
679}
680
681#endif /* __net_sctp_h__ */