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 */ 97 int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *addr, 98 enum sctp_scope, gfp_t gfp, int flags); 99 struct sctp_pf *sctp_get_pf_specific(sa_family_t family); 100 int sctp_register_pf(struct sctp_pf *, sa_family_t); 101 void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int); 102 103 /* 104 * sctp/socket.c 105 */ 106 int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr, 107 int addr_len, int flags); 108 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb); 109 int sctp_inet_listen(struct socket *sock, int backlog); 110 void sctp_write_space(struct sock *sk); 111 void sctp_data_ready(struct sock *sk); 112 __poll_t sctp_poll(struct file *file, struct socket *sock, 113 poll_table *wait); 114 void sctp_sock_rfree(struct sk_buff *skb); 115 void sctp_copy_sock(struct sock *newsk, struct sock *sk, 116 struct sctp_association *asoc); 117 extern struct percpu_counter sctp_sockets_allocated; 118 int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *); 119 struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *); 120 121 void sctp_transport_walk_start(struct rhashtable_iter *iter); 122 void sctp_transport_walk_stop(struct rhashtable_iter *iter); 123 struct sctp_transport *sctp_transport_get_next(struct net *net, 124 struct rhashtable_iter *iter); 125 struct sctp_transport *sctp_transport_get_idx(struct net *net, 126 struct rhashtable_iter *iter, int pos); 127 int 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); 131 int 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); 134 int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p); 135 int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc, 136 struct sctp_info *info); 137 138 /* 139 * sctp/primitive.c 140 */ 141 int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg); 142 int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg); 143 int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg); 144 int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg); 145 int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg); 146 int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg); 147 int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc, 148 void *arg); 149 150 /* 151 * sctp/input.c 152 */ 153 int sctp_rcv(struct sk_buff *skb); 154 void sctp_v4_err(struct sk_buff *skb, u32 info); 155 void sctp_hash_endpoint(struct sctp_endpoint *); 156 void sctp_unhash_endpoint(struct sctp_endpoint *); 157 struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *, 158 struct sctphdr *, struct sctp_association **, 159 struct sctp_transport **); 160 void sctp_err_finish(struct sock *, struct sctp_transport *); 161 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *, 162 struct sctp_transport *t, __u32 pmtu); 163 void sctp_icmp_redirect(struct sock *, struct sctp_transport *, 164 struct sk_buff *); 165 void sctp_icmp_proto_unreachable(struct sock *sk, 166 struct sctp_association *asoc, 167 struct sctp_transport *t); 168 void sctp_backlog_migrate(struct sctp_association *assoc, 169 struct sock *oldsk, struct sock *newsk); 170 int sctp_transport_hashtable_init(void); 171 void sctp_transport_hashtable_destroy(void); 172 int sctp_hash_transport(struct sctp_transport *t); 173 void sctp_unhash_transport(struct sctp_transport *t); 174 struct sctp_transport *sctp_addrs_lookup_transport( 175 struct net *net, 176 const union sctp_addr *laddr, 177 const union sctp_addr *paddr); 178 struct 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 */ 185 int __net_init sctp_proc_init(struct net *net); 186 187 /* 188 * sctp/offload.c 189 */ 190 int sctp_offload_init(void); 191 192 /* 193 * sctp/stream_sched.c 194 */ 195 void sctp_sched_ops_init(void); 196 197 /* 198 * sctp/stream.c 199 */ 200 int sctp_send_reset_streams(struct sctp_association *asoc, 201 struct sctp_reset_streams *params); 202 int sctp_send_reset_assoc(struct sctp_association *asoc); 203 int 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 */ 213 extern struct kmem_cache *sctp_chunk_cachep __read_mostly; 214 extern struct kmem_cache *sctp_bucket_cachep __read_mostly; 215 extern long sysctl_sctp_mem[3]; 216 extern int sysctl_sctp_rmem[3]; 217 extern 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 */ 229 enum { 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 268 struct sctp_mib { 269 unsigned long mibs[SCTP_MIB_MAX]; 270 }; 271 272 /* helper function to track stats about max rto and related transport */ 273 static 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 289 290 extern atomic_t sctp_dbg_objcnt_sock; 291 extern atomic_t sctp_dbg_objcnt_ep; 292 extern atomic_t sctp_dbg_objcnt_assoc; 293 extern atomic_t sctp_dbg_objcnt_transport; 294 extern atomic_t sctp_dbg_objcnt_chunk; 295 extern atomic_t sctp_dbg_objcnt_bind_addr; 296 extern atomic_t sctp_dbg_objcnt_bind_bucket; 297 extern atomic_t sctp_dbg_objcnt_addr; 298 extern atomic_t sctp_dbg_objcnt_datamsg; 299 extern atomic_t sctp_dbg_objcnt_keys; 300 301 /* Macros to atomically increment/decrement objcnt counters. */ 302 #define SCTP_DBG_OBJCNT_INC(name) \ 303 atomic_inc(&sctp_dbg_objcnt_## name) 304 #define SCTP_DBG_OBJCNT_DEC(name) \ 305 atomic_dec(&sctp_dbg_objcnt_## name) 306 #define SCTP_DBG_OBJCNT(name) \ 307 atomic_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} 314 315 void sctp_dbg_objcnt_init(struct net *); 316 317 #else 318 319 #define SCTP_DBG_OBJCNT_INC(name) 320 #define SCTP_DBG_OBJCNT_DEC(name) 321 322 static inline void sctp_dbg_objcnt_init(struct net *net) { return; } 323 324 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */ 325 326 #if defined CONFIG_SYSCTL 327 void sctp_sysctl_register(void); 328 void sctp_sysctl_unregister(void); 329 int sctp_sysctl_net_register(struct net *net); 330 void sctp_sysctl_net_unregister(struct net *net); 331 #else 332 static inline void sctp_sysctl_register(void) { return; } 333 static inline void sctp_sysctl_unregister(void) { return; } 334 static inline int sctp_sysctl_net_register(struct net *net) { return 0; } 335 static 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) 342 343 void sctp_v6_pf_init(void); 344 void sctp_v6_pf_exit(void); 345 int sctp_v6_protosw_init(void); 346 void sctp_v6_protosw_exit(void); 347 int sctp_v6_add_protocol(void); 348 void sctp_v6_del_protocol(void); 349 350 #else /* #ifdef defined(CONFIG_IPV6) */ 351 352 static inline void sctp_v6_pf_init(void) { return; } 353 static inline void sctp_v6_pf_exit(void) { return; } 354 static inline int sctp_v6_protosw_init(void) { return 0; } 355 static inline void sctp_v6_protosw_exit(void) { return; } 356 static inline int sctp_v6_add_protocol(void) { return 0; } 357 static 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. */ 363 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc) 364 { 365 return asoc ? asoc->assoc_id : 0; 366 } 367 368 static inline enum sctp_sstat_state 369 sctp_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. */ 382 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id); 383 384 int 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 */ 397 398 static 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 */ 413 static 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. */ 428 static inline int sctp_list_single_entry(struct list_head *head) 429 { 430 return (head->next != head) && (head->next == head->prev); 431 } 432 433 static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk) 434 { 435 return !list_empty(&chunk->list); 436 } 437 438 /* Walk through a list of TLV parameters. Don't trust the 439 * individual parameter lengths and instead depend on 440 * the chunk length to indicate when to stop. Make sure 441 * there is room for a param header too. 442 */ 443 #define sctp_walk_params(pos, chunk, member)\ 444 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member) 445 446 #define _sctp_walk_params(pos, chunk, end, member)\ 447 for (pos.v = chunk->member;\ 448 (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\ 449 (void *)chunk + end) &&\ 450 pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\ 451 ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\ 452 pos.v += SCTP_PAD4(ntohs(pos.p->length))) 453 454 #define sctp_walk_errors(err, chunk_hdr)\ 455 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length)) 456 457 #define _sctp_walk_errors(err, chunk_hdr, end)\ 458 for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \ 459 sizeof(struct sctp_chunkhdr));\ 460 ((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\ 461 (void *)chunk_hdr + end) &&\ 462 (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\ 463 ntohs(err->length) >= sizeof(struct sctp_errhdr); \ 464 err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length)))) 465 466 #define sctp_walk_fwdtsn(pos, chunk)\ 467 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk)) 468 469 #define _sctp_walk_fwdtsn(pos, chunk, end)\ 470 for (pos = chunk->subh.fwdtsn_hdr->skip;\ 471 (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\ 472 pos++) 473 474 /* External references. */ 475 476 extern struct proto sctp_prot; 477 extern struct proto sctpv6_prot; 478 void sctp_put_port(struct sock *sk); 479 480 extern struct idr sctp_assocs_id; 481 extern spinlock_t sctp_assocs_id_lock; 482 483 /* Static inline functions. */ 484 485 /* Convert from an IP version number to an Address Family symbol. */ 486 static inline int ipver2af(__u8 ipver) 487 { 488 switch (ipver) { 489 case 4: 490 return AF_INET; 491 case 6: 492 return AF_INET6; 493 default: 494 return 0; 495 } 496 } 497 498 /* Convert from an address parameter type to an address family. */ 499 static inline int param_type2af(__be16 type) 500 { 501 switch (type) { 502 case SCTP_PARAM_IPV4_ADDRESS: 503 return AF_INET; 504 case SCTP_PARAM_IPV6_ADDRESS: 505 return AF_INET6; 506 default: 507 return 0; 508 } 509 } 510 511 /* Warning: The following hash functions assume a power of two 'size'. */ 512 /* This is the hash function for the SCTP port hash table. */ 513 static inline int sctp_phashfn(struct net *net, __u16 lport) 514 { 515 return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1); 516 } 517 518 /* This is the hash function for the endpoint hash table. */ 519 static inline int sctp_ep_hashfn(struct net *net, __u16 lport) 520 { 521 return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1); 522 } 523 524 #define sctp_for_each_hentry(epb, head) \ 525 hlist_for_each_entry(epb, head, node) 526 527 /* Is a socket of this style? */ 528 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style)) 529 static inline int __sctp_style(const struct sock *sk, 530 enum sctp_socket_type style) 531 { 532 return sctp_sk(sk)->type == style; 533 } 534 535 /* Is the association in this state? */ 536 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state)) 537 static inline int __sctp_state(const struct sctp_association *asoc, 538 enum sctp_state state) 539 { 540 return asoc->state == state; 541 } 542 543 /* Is the socket in this state? */ 544 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state)) 545 static inline int __sctp_sstate(const struct sock *sk, 546 enum sctp_sock_state state) 547 { 548 return sk->sk_state == state; 549 } 550 551 /* Map v4-mapped v6 address back to v4 address */ 552 static inline void sctp_v6_map_v4(union sctp_addr *addr) 553 { 554 addr->v4.sin_family = AF_INET; 555 addr->v4.sin_port = addr->v6.sin6_port; 556 addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3]; 557 } 558 559 /* Map v4 address to v4-mapped v6 address */ 560 static inline void sctp_v4_map_v6(union sctp_addr *addr) 561 { 562 __be16 port; 563 564 port = addr->v4.sin_port; 565 addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 566 addr->v6.sin6_port = port; 567 addr->v6.sin6_family = AF_INET6; 568 addr->v6.sin6_flowinfo = 0; 569 addr->v6.sin6_scope_id = 0; 570 addr->v6.sin6_addr.s6_addr32[0] = 0; 571 addr->v6.sin6_addr.s6_addr32[1] = 0; 572 addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff); 573 } 574 575 /* The cookie is always 0 since this is how it's used in the 576 * pmtu code. 577 */ 578 static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t) 579 { 580 if (t->dst && !dst_check(t->dst, t->dst_cookie)) 581 sctp_transport_dst_release(t); 582 583 return t->dst; 584 } 585 586 /* Calculate max payload size given a MTU, or the total overhead if 587 * given MTU is zero 588 */ 589 static inline __u32 sctp_mtu_payload(const struct sctp_sock *sp, 590 __u32 mtu, __u32 extra) 591 { 592 __u32 overhead = sizeof(struct sctphdr) + extra; 593 594 if (sp) 595 overhead += sp->pf->af->net_header_len; 596 else 597 overhead += sizeof(struct ipv6hdr); 598 599 if (WARN_ON_ONCE(mtu && mtu <= overhead)) 600 mtu = overhead; 601 602 return mtu ? mtu - overhead : overhead; 603 } 604 605 static inline __u32 sctp_dst_mtu(const struct dst_entry *dst) 606 { 607 return SCTP_TRUNC4(max_t(__u32, dst_mtu(dst), 608 SCTP_DEFAULT_MINSEGMENT)); 609 } 610 611 #endif /* __net_sctp_h__ */ 612