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 */ 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) 309 310 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 320 static inline void sctp_sysctl_register(void) { return; } 321 static inline void sctp_sysctl_unregister(void) { return; } 322 static inline int sctp_sysctl_net_register(struct net *net) { return 0; } 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) */ 339 340 static inline void sctp_v6_pf_init(void) { return; } 341 static inline void sctp_v6_pf_exit(void) { return; } 342 static inline int sctp_v6_protosw_init(void) { return 0; } 343 static inline void sctp_v6_protosw_exit(void) { return; } 344 static inline int sctp_v6_add_protocol(void) { return 0; } 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. */ 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 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 */ 385 386 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 */ 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. */ 416 static inline int sctp_list_single_entry(struct list_head *head) 417 { 418 return list_is_singular(head); 419 } 420 421 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. */ 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. */ 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. */ 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. */ 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(ep, head) \ 513 hlist_for_each_entry(ep, head, node) 514 515 /* Is a socket of this style? */ 516 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##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)) 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)) 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 */ 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 */ 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 */ 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 */ 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 } 596 597 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 } 602 603 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 } 608 609 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 } 620 621 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 } 625 626 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 } 631 632 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 } 650 651 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 } 661 662 static inline bool sctp_transport_pl_enabled(struct sctp_transport *t) 663 { 664 return t->pl.state != SCTP_PL_DISABLED; 665 } 666 667 static inline bool sctp_newsk_ready(const struct sock *sk) 668 { 669 return sock_flag(sk, SOCK_DEAD) || sk->sk_socket; 670 } 671 672 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