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