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 dependencies: 32 * includes 33 * constants 34 * structs 35 * prototypes 36 * macros, externs, and inlines 37 * 38 * Move test_frame specific items out of the kernel headers 39 * and into the test frame headers. This is not perfect in any sense 40 * and will continue to evolve. 41 */ 42 43 #include <linux/types.h> 44 #include <linux/slab.h> 45 #include <linux/in.h> 46 #include <linux/tty.h> 47 #include <linux/proc_fs.h> 48 #include <linux/spinlock.h> 49 #include <linux/jiffies.h> 50 #include <linux/idr.h> 51 52 #if IS_ENABLED(CONFIG_IPV6) 53 #include <net/ipv6.h> 54 #include <net/ip6_route.h> 55 #endif 56 57 #include <linux/uaccess.h> 58 #include <asm/page.h> 59 #include <net/sock.h> 60 #include <net/snmp.h> 61 #include <net/sctp/structs.h> 62 #include <net/sctp/constants.h> 63 64 #ifdef CONFIG_IP_SCTP_MODULE 65 #define SCTP_PROTOSW_FLAG 0 66 #else /* static! */ 67 #define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT 68 #endif 69 70 /* 71 * Function declarations. 72 */ 73 74 /* 75 * sctp/protocol.c 76 */ 77 int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *addr, 78 enum sctp_scope, gfp_t gfp, int flags); 79 struct sctp_pf *sctp_get_pf_specific(sa_family_t family); 80 int sctp_register_pf(struct sctp_pf *, sa_family_t); 81 void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int); 82 int sctp_udp_sock_start(struct net *net); 83 void sctp_udp_sock_stop(struct net *net); 84 85 /* 86 * sctp/socket.c 87 */ 88 int sctp_inet_connect(struct socket *sock, struct sockaddr_unsized *uaddr, 89 int addr_len, int flags); 90 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb); 91 int sctp_inet_listen(struct socket *sock, int backlog); 92 void sctp_write_space(struct sock *sk); 93 void sctp_data_ready(struct sock *sk); 94 __poll_t sctp_poll(struct file *file, struct socket *sock, 95 poll_table *wait); 96 void sctp_sock_rfree(struct sk_buff *skb); 97 98 extern struct percpu_counter sctp_sockets_allocated; 99 int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *); 100 struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int *); 101 102 typedef int (*sctp_callback_t)(struct sctp_endpoint *, struct sctp_transport *, void *); 103 void sctp_transport_walk_start(struct rhashtable_iter *iter); 104 void sctp_transport_walk_stop(struct rhashtable_iter *iter); 105 struct sctp_transport *sctp_transport_get_next(struct net *net, 106 struct rhashtable_iter *iter); 107 struct sctp_transport *sctp_transport_get_idx(struct net *net, 108 struct rhashtable_iter *iter, int pos); 109 int sctp_transport_lookup_process(sctp_callback_t cb, struct net *net, 110 const union sctp_addr *laddr, 111 const union sctp_addr *paddr, void *p, int dif); 112 int sctp_transport_traverse_process(sctp_callback_t cb, sctp_callback_t cb_done, 113 struct net *net, int *pos, void *p); 114 int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p); 115 int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc, 116 struct sctp_info *info); 117 118 /* 119 * sctp/primitive.c 120 */ 121 int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg); 122 int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg); 123 int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg); 124 int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg); 125 int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg); 126 int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg); 127 int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc, 128 void *arg); 129 130 /* 131 * sctp/input.c 132 */ 133 int sctp_rcv(struct sk_buff *skb); 134 int sctp_v4_err(struct sk_buff *skb, u32 info); 135 int sctp_hash_endpoint(struct sctp_endpoint *ep); 136 void sctp_unhash_endpoint(struct sctp_endpoint *); 137 struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *, 138 struct sctphdr *, struct sctp_association **, 139 struct sctp_transport **); 140 void sctp_err_finish(struct sock *, struct sctp_transport *); 141 int sctp_udp_v4_err(struct sock *sk, struct sk_buff *skb); 142 int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb); 143 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *, 144 struct sctp_transport *t, __u32 pmtu); 145 void sctp_icmp_redirect(struct sock *, struct sctp_transport *, 146 struct sk_buff *); 147 void sctp_icmp_proto_unreachable(struct sock *sk, 148 struct sctp_association *asoc, 149 struct sctp_transport *t); 150 int sctp_transport_hashtable_init(void); 151 void sctp_transport_hashtable_destroy(void); 152 int sctp_hash_transport(struct sctp_transport *t); 153 void sctp_unhash_transport(struct sctp_transport *t); 154 struct sctp_transport *sctp_addrs_lookup_transport( 155 struct net *net, 156 const union sctp_addr *laddr, 157 const union sctp_addr *paddr, 158 int dif, int sdif); 159 struct sctp_transport *sctp_epaddr_lookup_transport( 160 const struct sctp_endpoint *ep, 161 const union sctp_addr *paddr); 162 bool sctp_sk_bound_dev_eq(struct net *net, int bound_dev_if, int dif, int sdif); 163 164 /* 165 * sctp/proc.c 166 */ 167 int __net_init sctp_proc_init(struct net *net); 168 169 /* 170 * sctp/offload.c 171 */ 172 int sctp_offload_init(void); 173 174 /* 175 * sctp/stream_sched.c 176 */ 177 void sctp_sched_ops_init(void); 178 179 /* 180 * sctp/stream.c 181 */ 182 int sctp_send_reset_streams(struct sctp_association *asoc, 183 struct sctp_reset_streams *params); 184 int sctp_send_reset_assoc(struct sctp_association *asoc); 185 int sctp_send_add_streams(struct sctp_association *asoc, 186 struct sctp_add_streams *params); 187 188 /* 189 * Module global variables 190 */ 191 192 /* 193 * sctp/protocol.c 194 */ 195 extern struct kmem_cache *sctp_chunk_cachep __read_mostly; 196 extern struct kmem_cache *sctp_bucket_cachep __read_mostly; 197 extern long sysctl_sctp_mem[3]; 198 extern int sysctl_sctp_rmem[3]; 199 extern int sysctl_sctp_wmem[3]; 200 201 /* 202 * Section: Macros, externs, and inlines 203 */ 204 205 /* SCTP SNMP MIB stats handlers */ 206 #define SCTP_INC_STATS(net, field) SNMP_INC_STATS((net)->sctp.sctp_statistics, field) 207 #define __SCTP_INC_STATS(net, field) __SNMP_INC_STATS((net)->sctp.sctp_statistics, field) 208 #define SCTP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->sctp.sctp_statistics, field) 209 210 /* sctp mib definitions */ 211 enum { 212 SCTP_MIB_NUM = 0, 213 SCTP_MIB_CURRESTAB, /* CurrEstab */ 214 SCTP_MIB_ACTIVEESTABS, /* ActiveEstabs */ 215 SCTP_MIB_PASSIVEESTABS, /* PassiveEstabs */ 216 SCTP_MIB_ABORTEDS, /* Aborteds */ 217 SCTP_MIB_SHUTDOWNS, /* Shutdowns */ 218 SCTP_MIB_OUTOFBLUES, /* OutOfBlues */ 219 SCTP_MIB_CHECKSUMERRORS, /* ChecksumErrors */ 220 SCTP_MIB_OUTCTRLCHUNKS, /* OutCtrlChunks */ 221 SCTP_MIB_OUTORDERCHUNKS, /* OutOrderChunks */ 222 SCTP_MIB_OUTUNORDERCHUNKS, /* OutUnorderChunks */ 223 SCTP_MIB_INCTRLCHUNKS, /* InCtrlChunks */ 224 SCTP_MIB_INORDERCHUNKS, /* InOrderChunks */ 225 SCTP_MIB_INUNORDERCHUNKS, /* InUnorderChunks */ 226 SCTP_MIB_FRAGUSRMSGS, /* FragUsrMsgs */ 227 SCTP_MIB_REASMUSRMSGS, /* ReasmUsrMsgs */ 228 SCTP_MIB_OUTSCTPPACKS, /* OutSCTPPacks */ 229 SCTP_MIB_INSCTPPACKS, /* InSCTPPacks */ 230 SCTP_MIB_T1_INIT_EXPIREDS, 231 SCTP_MIB_T1_COOKIE_EXPIREDS, 232 SCTP_MIB_T2_SHUTDOWN_EXPIREDS, 233 SCTP_MIB_T3_RTX_EXPIREDS, 234 SCTP_MIB_T4_RTO_EXPIREDS, 235 SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS, 236 SCTP_MIB_DELAY_SACK_EXPIREDS, 237 SCTP_MIB_AUTOCLOSE_EXPIREDS, 238 SCTP_MIB_T1_RETRANSMITS, 239 SCTP_MIB_T3_RETRANSMITS, 240 SCTP_MIB_PMTUD_RETRANSMITS, 241 SCTP_MIB_FAST_RETRANSMITS, 242 SCTP_MIB_IN_PKT_SOFTIRQ, 243 SCTP_MIB_IN_PKT_BACKLOG, 244 SCTP_MIB_IN_PKT_DISCARDS, 245 SCTP_MIB_IN_DATA_CHUNK_DISCARDS, 246 __SCTP_MIB_MAX 247 }; 248 249 #define SCTP_MIB_MAX __SCTP_MIB_MAX 250 struct sctp_mib { 251 unsigned long mibs[SCTP_MIB_MAX]; 252 }; 253 254 /* helper function to track stats about max rto and related transport */ 255 static inline void sctp_max_rto(struct sctp_association *asoc, 256 struct sctp_transport *trans) 257 { 258 if (asoc->stats.max_obs_rto < (__u64)trans->rto) { 259 asoc->stats.max_obs_rto = trans->rto; 260 memset(&asoc->stats.obs_rto_ipaddr, 0, 261 sizeof(struct sockaddr_storage)); 262 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr, 263 trans->af_specific->sockaddr_len); 264 } 265 } 266 267 /* 268 * Macros for keeping a global reference of object allocations. 269 */ 270 #ifdef CONFIG_SCTP_DBG_OBJCNT 271 272 extern atomic_t sctp_dbg_objcnt_sock; 273 extern atomic_t sctp_dbg_objcnt_ep; 274 extern atomic_t sctp_dbg_objcnt_assoc; 275 extern atomic_t sctp_dbg_objcnt_transport; 276 extern atomic_t sctp_dbg_objcnt_chunk; 277 extern atomic_t sctp_dbg_objcnt_bind_addr; 278 extern atomic_t sctp_dbg_objcnt_bind_bucket; 279 extern atomic_t sctp_dbg_objcnt_addr; 280 extern atomic_t sctp_dbg_objcnt_datamsg; 281 extern atomic_t sctp_dbg_objcnt_keys; 282 283 /* Macros to atomically increment/decrement objcnt counters. */ 284 #define SCTP_DBG_OBJCNT_INC(name) \ 285 atomic_inc(&sctp_dbg_objcnt_## name) 286 #define SCTP_DBG_OBJCNT_DEC(name) \ 287 atomic_dec(&sctp_dbg_objcnt_## name) 288 #define SCTP_DBG_OBJCNT(name) \ 289 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0) 290 291 /* Macro to help create new entries in the global array of 292 * objcnt counters. 293 */ 294 #define SCTP_DBG_OBJCNT_ENTRY(name) \ 295 {.label= #name, .counter= &sctp_dbg_objcnt_## name} 296 297 void sctp_dbg_objcnt_init(struct net *); 298 299 #else 300 301 #define SCTP_DBG_OBJCNT_INC(name) 302 #define SCTP_DBG_OBJCNT_DEC(name) 303 304 static inline void sctp_dbg_objcnt_init(struct net *net) { return; } 305 306 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */ 307 308 #if defined CONFIG_SYSCTL 309 void sctp_sysctl_register(void); 310 void sctp_sysctl_unregister(void); 311 int sctp_sysctl_net_register(struct net *net); 312 void sctp_sysctl_net_unregister(struct net *net); 313 #else 314 static inline void sctp_sysctl_register(void) { return; } 315 static inline void sctp_sysctl_unregister(void) { return; } 316 static inline int sctp_sysctl_net_register(struct net *net) { return 0; } 317 static inline void sctp_sysctl_net_unregister(struct net *net) { return; } 318 #endif 319 320 /* Size of Supported Address Parameter for 'x' address types. */ 321 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16)) 322 323 #if IS_ENABLED(CONFIG_IPV6) 324 325 void sctp_v6_pf_init(void); 326 void sctp_v6_pf_exit(void); 327 int sctp_v6_protosw_init(void); 328 void sctp_v6_protosw_exit(void); 329 int sctp_v6_add_protocol(void); 330 void sctp_v6_del_protocol(void); 331 332 #else /* #ifdef defined(CONFIG_IPV6) */ 333 334 static inline void sctp_v6_pf_init(void) { return; } 335 static inline void sctp_v6_pf_exit(void) { return; } 336 static inline int sctp_v6_protosw_init(void) { return 0; } 337 static inline void sctp_v6_protosw_exit(void) { return; } 338 static inline int sctp_v6_add_protocol(void) { return 0; } 339 static inline void sctp_v6_del_protocol(void) { return; } 340 341 #endif /* #if defined(CONFIG_IPV6) */ 342 343 344 /* Map an association to an assoc_id. */ 345 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc) 346 { 347 return asoc ? asoc->assoc_id : 0; 348 } 349 350 static inline enum sctp_sstat_state 351 sctp_assoc_to_state(const struct sctp_association *asoc) 352 { 353 /* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we 354 * got rid of it in kernel space. Therefore SCTP_CLOSED et al 355 * start at =1 in user space, but actually as =0 in kernel space. 356 * Now that we can not break user space and SCTP_EMPTY is exposed 357 * there, we need to fix it up with an ugly offset not to break 358 * applications. :( 359 */ 360 return asoc->state + 1; 361 } 362 363 /* Look up the association by its id. */ 364 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id); 365 366 /* A macro to walk a list of skbs. */ 367 #define sctp_skb_for_each(pos, head, tmp) \ 368 skb_queue_walk_safe(head, pos, tmp) 369 370 /** 371 * sctp_list_dequeue - remove from the head of the queue 372 * @list: list to dequeue from 373 * 374 * Remove the head of the list. The head item is 375 * returned or %NULL if the list is empty. 376 */ 377 378 static inline struct list_head *sctp_list_dequeue(struct list_head *list) 379 { 380 struct list_head *result = NULL; 381 382 if (!list_empty(list)) { 383 result = list->next; 384 list_del_init(result); 385 } 386 return result; 387 } 388 389 /* SCTP version of skb_set_owner_r. We need this one because 390 * of the way we have to do receive buffer accounting on bundled 391 * chunks. 392 */ 393 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 394 { 395 struct sctp_ulpevent *event = sctp_skb2event(skb); 396 397 skb_orphan(skb); 398 skb->sk = sk; 399 skb->destructor = sctp_sock_rfree; 400 atomic_add(event->rmem_len, &sk->sk_rmem_alloc); 401 /* 402 * This mimics the behavior of skb_set_owner_r 403 */ 404 sk_mem_charge(sk, event->rmem_len); 405 } 406 407 /* Tests if the list has one and only one entry. */ 408 static inline int sctp_list_single_entry(struct list_head *head) 409 { 410 return list_is_singular(head); 411 } 412 413 static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk) 414 { 415 return !list_empty(&chunk->list); 416 } 417 418 /* Walk through a list of TLV parameters. Don't trust the 419 * individual parameter lengths and instead depend on 420 * the chunk length to indicate when to stop. Make sure 421 * there is room for a param header too. 422 */ 423 #define sctp_walk_params(pos, chunk)\ 424 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length)) 425 426 #define _sctp_walk_params(pos, chunk, end)\ 427 for (pos.v = (u8 *)(chunk + 1);\ 428 (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\ 429 (void *)chunk + end) &&\ 430 pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\ 431 ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\ 432 pos.v += SCTP_PAD4(ntohs(pos.p->length))) 433 434 #define sctp_walk_errors(err, chunk_hdr)\ 435 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length)) 436 437 #define _sctp_walk_errors(err, chunk_hdr, end)\ 438 for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \ 439 sizeof(struct sctp_chunkhdr));\ 440 ((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\ 441 (void *)chunk_hdr + end) &&\ 442 (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\ 443 ntohs(err->length) >= sizeof(struct sctp_errhdr); \ 444 err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length)))) 445 446 #define sctp_walk_fwdtsn(pos, chunk)\ 447 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk)) 448 449 #define _sctp_walk_fwdtsn(pos, chunk, end)\ 450 for (pos = (void *)(chunk->subh.fwdtsn_hdr + 1);\ 451 (void *)pos <= (void *)(chunk->subh.fwdtsn_hdr + 1) + end - sizeof(struct sctp_fwdtsn_skip);\ 452 pos++) 453 454 /* External references. */ 455 456 extern struct proto sctp_prot; 457 extern struct proto sctpv6_prot; 458 void sctp_put_port(struct sock *sk); 459 460 extern struct idr sctp_assocs_id; 461 extern spinlock_t sctp_assocs_id_lock; 462 463 /* Static inline functions. */ 464 465 /* Convert from an IP version number to an Address Family symbol. */ 466 static inline int ipver2af(__u8 ipver) 467 { 468 switch (ipver) { 469 case 4: 470 return AF_INET; 471 case 6: 472 return AF_INET6; 473 default: 474 return 0; 475 } 476 } 477 478 /* Convert from an address parameter type to an address family. */ 479 static inline int param_type2af(__be16 type) 480 { 481 switch (type) { 482 case SCTP_PARAM_IPV4_ADDRESS: 483 return AF_INET; 484 case SCTP_PARAM_IPV6_ADDRESS: 485 return AF_INET6; 486 default: 487 return 0; 488 } 489 } 490 491 /* Warning: The following hash functions assume a power of two 'size'. */ 492 /* This is the hash function for the SCTP port hash table. */ 493 static inline int sctp_phashfn(struct net *net, __u16 lport) 494 { 495 return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1); 496 } 497 498 /* This is the hash function for the endpoint hash table. */ 499 static inline int sctp_ep_hashfn(struct net *net, __u16 lport) 500 { 501 return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1); 502 } 503 504 #define sctp_for_each_hentry(ep, head) \ 505 hlist_for_each_entry(ep, head, node) 506 507 /* Is a socket of this style? */ 508 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style)) 509 static inline int __sctp_style(const struct sock *sk, 510 enum sctp_socket_type style) 511 { 512 return sctp_sk(sk)->type == style; 513 } 514 515 /* Is the association in this state? */ 516 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state)) 517 static inline int __sctp_state(const struct sctp_association *asoc, 518 enum sctp_state state) 519 { 520 return asoc->state == state; 521 } 522 523 /* Is the socket in this state? */ 524 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state)) 525 static inline int __sctp_sstate(const struct sock *sk, 526 enum sctp_sock_state state) 527 { 528 return sk->sk_state == state; 529 } 530 531 /* Map v4-mapped v6 address back to v4 address */ 532 static inline void sctp_v6_map_v4(union sctp_addr *addr) 533 { 534 addr->v4.sin_family = AF_INET; 535 addr->v4.sin_port = addr->v6.sin6_port; 536 addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3]; 537 } 538 539 /* Map v4 address to v4-mapped v6 address */ 540 static inline void sctp_v4_map_v6(union sctp_addr *addr) 541 { 542 __be16 port; 543 544 port = addr->v4.sin_port; 545 addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 546 addr->v6.sin6_port = port; 547 addr->v6.sin6_family = AF_INET6; 548 addr->v6.sin6_flowinfo = 0; 549 addr->v6.sin6_scope_id = 0; 550 addr->v6.sin6_addr.s6_addr32[0] = 0; 551 addr->v6.sin6_addr.s6_addr32[1] = 0; 552 addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff); 553 } 554 555 /* The cookie is always 0 since this is how it's used in the 556 * pmtu code. 557 */ 558 static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t) 559 { 560 if (t->dst && !dst_check(t->dst, t->dst_cookie)) 561 sctp_transport_dst_release(t); 562 563 return t->dst; 564 } 565 566 /* Calculate max payload size given a MTU, or the total overhead if 567 * given MTU is zero 568 */ 569 static inline __u32 __sctp_mtu_payload(const struct sctp_sock *sp, 570 const struct sctp_transport *t, 571 __u32 mtu, __u32 extra) 572 { 573 __u32 overhead = sizeof(struct sctphdr) + extra; 574 575 if (sp) { 576 overhead += sp->pf->af->net_header_len; 577 if (sp->udp_port && (!t || t->encap_port)) 578 overhead += sizeof(struct udphdr); 579 } else { 580 overhead += sizeof(struct ipv6hdr); 581 } 582 583 if (WARN_ON_ONCE(mtu && mtu <= overhead)) 584 mtu = overhead; 585 586 return mtu ? mtu - overhead : overhead; 587 } 588 589 static inline __u32 sctp_mtu_payload(const struct sctp_sock *sp, 590 __u32 mtu, __u32 extra) 591 { 592 return __sctp_mtu_payload(sp, NULL, mtu, extra); 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 int sctp_transport_pl_hlen(struct sctp_transport *t) 619 { 620 return __sctp_mtu_payload(sctp_sk(t->asoc->base.sk), t, 0, 0) - 621 sizeof(struct sctphdr); 622 } 623 624 static inline void sctp_transport_pl_reset(struct sctp_transport *t) 625 { 626 if (t->probe_interval && (t->param_flags & SPP_PMTUD_ENABLE) && 627 (t->state == SCTP_ACTIVE || t->state == SCTP_UNKNOWN)) { 628 if (t->pl.state == SCTP_PL_DISABLED) { 629 t->pl.state = SCTP_PL_BASE; 630 t->pl.pmtu = SCTP_BASE_PLPMTU; 631 t->pl.probe_size = SCTP_BASE_PLPMTU; 632 sctp_transport_reset_probe_timer(t); 633 } 634 } else { 635 if (t->pl.state != SCTP_PL_DISABLED) { 636 if (timer_delete(&t->probe_timer)) 637 sctp_transport_put(t); 638 t->pl.state = SCTP_PL_DISABLED; 639 } 640 } 641 } 642 643 static inline void sctp_transport_pl_update(struct sctp_transport *t) 644 { 645 if (t->pl.state == SCTP_PL_DISABLED) 646 return; 647 648 t->pl.state = SCTP_PL_BASE; 649 t->pl.pmtu = SCTP_BASE_PLPMTU; 650 t->pl.probe_size = SCTP_BASE_PLPMTU; 651 sctp_transport_reset_probe_timer(t); 652 } 653 654 static inline bool sctp_transport_pl_enabled(struct sctp_transport *t) 655 { 656 return t->pl.state != SCTP_PL_DISABLED; 657 } 658 659 static inline bool sctp_newsk_ready(const struct sock *sk) 660 { 661 return sock_flag(sk, SOCK_DEAD) || sk->sk_socket; 662 } 663 664 static inline void sctp_sock_set_nodelay(struct sock *sk) 665 { 666 lock_sock(sk); 667 sctp_sk(sk)->nodelay = true; 668 release_sock(sk); 669 } 670 671 #endif /* __net_sctp_h__ */ 672