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