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 int sctp_udp_v4_err(struct sock *sk, struct sk_buff *skb); 149 int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb); 150 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *, 151 struct sctp_transport *t, __u32 pmtu); 152 void sctp_icmp_redirect(struct sock *, struct sctp_transport *, 153 struct sk_buff *); 154 void sctp_icmp_proto_unreachable(struct sock *sk, 155 struct sctp_association *asoc, 156 struct sctp_transport *t); 157 void sctp_backlog_migrate(struct sctp_association *assoc, 158 struct sock *oldsk, struct sock *newsk); 159 int sctp_transport_hashtable_init(void); 160 void sctp_transport_hashtable_destroy(void); 161 int sctp_hash_transport(struct sctp_transport *t); 162 void sctp_unhash_transport(struct sctp_transport *t); 163 struct sctp_transport *sctp_addrs_lookup_transport( 164 struct net *net, 165 const union sctp_addr *laddr, 166 const union sctp_addr *paddr); 167 struct sctp_transport *sctp_epaddr_lookup_transport( 168 const struct sctp_endpoint *ep, 169 const union sctp_addr *paddr); 170 171 /* 172 * sctp/proc.c 173 */ 174 int __net_init sctp_proc_init(struct net *net); 175 176 /* 177 * sctp/offload.c 178 */ 179 int sctp_offload_init(void); 180 181 /* 182 * sctp/stream_sched.c 183 */ 184 void sctp_sched_ops_init(void); 185 186 /* 187 * sctp/stream.c 188 */ 189 int sctp_send_reset_streams(struct sctp_association *asoc, 190 struct sctp_reset_streams *params); 191 int sctp_send_reset_assoc(struct sctp_association *asoc); 192 int sctp_send_add_streams(struct sctp_association *asoc, 193 struct sctp_add_streams *params); 194 195 /* 196 * Module global variables 197 */ 198 199 /* 200 * sctp/protocol.c 201 */ 202 extern struct kmem_cache *sctp_chunk_cachep __read_mostly; 203 extern struct kmem_cache *sctp_bucket_cachep __read_mostly; 204 extern long sysctl_sctp_mem[3]; 205 extern int sysctl_sctp_rmem[3]; 206 extern int sysctl_sctp_wmem[3]; 207 208 /* 209 * Section: Macros, externs, and inlines 210 */ 211 212 /* SCTP SNMP MIB stats handlers */ 213 #define SCTP_INC_STATS(net, field) SNMP_INC_STATS((net)->sctp.sctp_statistics, field) 214 #define __SCTP_INC_STATS(net, field) __SNMP_INC_STATS((net)->sctp.sctp_statistics, field) 215 #define SCTP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->sctp.sctp_statistics, field) 216 217 /* sctp mib definitions */ 218 enum { 219 SCTP_MIB_NUM = 0, 220 SCTP_MIB_CURRESTAB, /* CurrEstab */ 221 SCTP_MIB_ACTIVEESTABS, /* ActiveEstabs */ 222 SCTP_MIB_PASSIVEESTABS, /* PassiveEstabs */ 223 SCTP_MIB_ABORTEDS, /* Aborteds */ 224 SCTP_MIB_SHUTDOWNS, /* Shutdowns */ 225 SCTP_MIB_OUTOFBLUES, /* OutOfBlues */ 226 SCTP_MIB_CHECKSUMERRORS, /* ChecksumErrors */ 227 SCTP_MIB_OUTCTRLCHUNKS, /* OutCtrlChunks */ 228 SCTP_MIB_OUTORDERCHUNKS, /* OutOrderChunks */ 229 SCTP_MIB_OUTUNORDERCHUNKS, /* OutUnorderChunks */ 230 SCTP_MIB_INCTRLCHUNKS, /* InCtrlChunks */ 231 SCTP_MIB_INORDERCHUNKS, /* InOrderChunks */ 232 SCTP_MIB_INUNORDERCHUNKS, /* InUnorderChunks */ 233 SCTP_MIB_FRAGUSRMSGS, /* FragUsrMsgs */ 234 SCTP_MIB_REASMUSRMSGS, /* ReasmUsrMsgs */ 235 SCTP_MIB_OUTSCTPPACKS, /* OutSCTPPacks */ 236 SCTP_MIB_INSCTPPACKS, /* InSCTPPacks */ 237 SCTP_MIB_T1_INIT_EXPIREDS, 238 SCTP_MIB_T1_COOKIE_EXPIREDS, 239 SCTP_MIB_T2_SHUTDOWN_EXPIREDS, 240 SCTP_MIB_T3_RTX_EXPIREDS, 241 SCTP_MIB_T4_RTO_EXPIREDS, 242 SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS, 243 SCTP_MIB_DELAY_SACK_EXPIREDS, 244 SCTP_MIB_AUTOCLOSE_EXPIREDS, 245 SCTP_MIB_T1_RETRANSMITS, 246 SCTP_MIB_T3_RETRANSMITS, 247 SCTP_MIB_PMTUD_RETRANSMITS, 248 SCTP_MIB_FAST_RETRANSMITS, 249 SCTP_MIB_IN_PKT_SOFTIRQ, 250 SCTP_MIB_IN_PKT_BACKLOG, 251 SCTP_MIB_IN_PKT_DISCARDS, 252 SCTP_MIB_IN_DATA_CHUNK_DISCARDS, 253 __SCTP_MIB_MAX 254 }; 255 256 #define SCTP_MIB_MAX __SCTP_MIB_MAX 257 struct sctp_mib { 258 unsigned long mibs[SCTP_MIB_MAX]; 259 }; 260 261 /* helper function to track stats about max rto and related transport */ 262 static inline void sctp_max_rto(struct sctp_association *asoc, 263 struct sctp_transport *trans) 264 { 265 if (asoc->stats.max_obs_rto < (__u64)trans->rto) { 266 asoc->stats.max_obs_rto = trans->rto; 267 memset(&asoc->stats.obs_rto_ipaddr, 0, 268 sizeof(struct sockaddr_storage)); 269 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr, 270 trans->af_specific->sockaddr_len); 271 } 272 } 273 274 /* 275 * Macros for keeping a global reference of object allocations. 276 */ 277 #ifdef CONFIG_SCTP_DBG_OBJCNT 278 279 extern atomic_t sctp_dbg_objcnt_sock; 280 extern atomic_t sctp_dbg_objcnt_ep; 281 extern atomic_t sctp_dbg_objcnt_assoc; 282 extern atomic_t sctp_dbg_objcnt_transport; 283 extern atomic_t sctp_dbg_objcnt_chunk; 284 extern atomic_t sctp_dbg_objcnt_bind_addr; 285 extern atomic_t sctp_dbg_objcnt_bind_bucket; 286 extern atomic_t sctp_dbg_objcnt_addr; 287 extern atomic_t sctp_dbg_objcnt_datamsg; 288 extern atomic_t sctp_dbg_objcnt_keys; 289 290 /* Macros to atomically increment/decrement objcnt counters. */ 291 #define SCTP_DBG_OBJCNT_INC(name) \ 292 atomic_inc(&sctp_dbg_objcnt_## name) 293 #define SCTP_DBG_OBJCNT_DEC(name) \ 294 atomic_dec(&sctp_dbg_objcnt_## name) 295 #define SCTP_DBG_OBJCNT(name) \ 296 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0) 297 298 /* Macro to help create new entries in the global array of 299 * objcnt counters. 300 */ 301 #define SCTP_DBG_OBJCNT_ENTRY(name) \ 302 {.label= #name, .counter= &sctp_dbg_objcnt_## name} 303 304 void sctp_dbg_objcnt_init(struct net *); 305 306 #else 307 308 #define SCTP_DBG_OBJCNT_INC(name) 309 #define SCTP_DBG_OBJCNT_DEC(name) 310 311 static inline void sctp_dbg_objcnt_init(struct net *net) { return; } 312 313 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */ 314 315 #if defined CONFIG_SYSCTL 316 void sctp_sysctl_register(void); 317 void sctp_sysctl_unregister(void); 318 int sctp_sysctl_net_register(struct net *net); 319 void sctp_sysctl_net_unregister(struct net *net); 320 #else 321 static inline void sctp_sysctl_register(void) { return; } 322 static inline void sctp_sysctl_unregister(void) { return; } 323 static inline int sctp_sysctl_net_register(struct net *net) { return 0; } 324 static inline void sctp_sysctl_net_unregister(struct net *net) { return; } 325 #endif 326 327 /* Size of Supported Address Parameter for 'x' address types. */ 328 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16)) 329 330 #if IS_ENABLED(CONFIG_IPV6) 331 332 void sctp_v6_pf_init(void); 333 void sctp_v6_pf_exit(void); 334 int sctp_v6_protosw_init(void); 335 void sctp_v6_protosw_exit(void); 336 int sctp_v6_add_protocol(void); 337 void sctp_v6_del_protocol(void); 338 339 #else /* #ifdef defined(CONFIG_IPV6) */ 340 341 static inline void sctp_v6_pf_init(void) { return; } 342 static inline void sctp_v6_pf_exit(void) { return; } 343 static inline int sctp_v6_protosw_init(void) { return 0; } 344 static inline void sctp_v6_protosw_exit(void) { return; } 345 static inline int sctp_v6_add_protocol(void) { return 0; } 346 static inline void sctp_v6_del_protocol(void) { return; } 347 348 #endif /* #if defined(CONFIG_IPV6) */ 349 350 351 /* Map an association to an assoc_id. */ 352 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc) 353 { 354 return asoc ? asoc->assoc_id : 0; 355 } 356 357 static inline enum sctp_sstat_state 358 sctp_assoc_to_state(const struct sctp_association *asoc) 359 { 360 /* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we 361 * got rid of it in kernel space. Therefore SCTP_CLOSED et al 362 * start at =1 in user space, but actually as =0 in kernel space. 363 * Now that we can not break user space and SCTP_EMPTY is exposed 364 * there, we need to fix it up with an ugly offset not to break 365 * applications. :( 366 */ 367 return asoc->state + 1; 368 } 369 370 /* Look up the association by its id. */ 371 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id); 372 373 int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp); 374 375 /* A macro to walk a list of skbs. */ 376 #define sctp_skb_for_each(pos, head, tmp) \ 377 skb_queue_walk_safe(head, pos, tmp) 378 379 /** 380 * sctp_list_dequeue - remove from the head of the queue 381 * @list: list to dequeue from 382 * 383 * Remove the head of the list. The head item is 384 * returned or %NULL if the list is empty. 385 */ 386 387 static inline struct list_head *sctp_list_dequeue(struct list_head *list) 388 { 389 struct list_head *result = NULL; 390 391 if (!list_empty(list)) { 392 result = list->next; 393 list_del_init(result); 394 } 395 return result; 396 } 397 398 /* SCTP version of skb_set_owner_r. We need this one because 399 * of the way we have to do receive buffer accounting on bundled 400 * chunks. 401 */ 402 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 403 { 404 struct sctp_ulpevent *event = sctp_skb2event(skb); 405 406 skb_orphan(skb); 407 skb->sk = sk; 408 skb->destructor = sctp_sock_rfree; 409 atomic_add(event->rmem_len, &sk->sk_rmem_alloc); 410 /* 411 * This mimics the behavior of skb_set_owner_r 412 */ 413 sk_mem_charge(sk, event->rmem_len); 414 } 415 416 /* Tests if the list has one and only one entry. */ 417 static inline int sctp_list_single_entry(struct list_head *head) 418 { 419 return list_is_singular(head); 420 } 421 422 static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk) 423 { 424 return !list_empty(&chunk->list); 425 } 426 427 /* Walk through a list of TLV parameters. Don't trust the 428 * individual parameter lengths and instead depend on 429 * the chunk length to indicate when to stop. Make sure 430 * there is room for a param header too. 431 */ 432 #define sctp_walk_params(pos, chunk, member)\ 433 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member) 434 435 #define _sctp_walk_params(pos, chunk, end, member)\ 436 for (pos.v = chunk->member;\ 437 (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\ 438 (void *)chunk + end) &&\ 439 pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\ 440 ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\ 441 pos.v += SCTP_PAD4(ntohs(pos.p->length))) 442 443 #define sctp_walk_errors(err, chunk_hdr)\ 444 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length)) 445 446 #define _sctp_walk_errors(err, chunk_hdr, end)\ 447 for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \ 448 sizeof(struct sctp_chunkhdr));\ 449 ((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\ 450 (void *)chunk_hdr + end) &&\ 451 (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\ 452 ntohs(err->length) >= sizeof(struct sctp_errhdr); \ 453 err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length)))) 454 455 #define sctp_walk_fwdtsn(pos, chunk)\ 456 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk)) 457 458 #define _sctp_walk_fwdtsn(pos, chunk, end)\ 459 for (pos = chunk->subh.fwdtsn_hdr->skip;\ 460 (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\ 461 pos++) 462 463 /* External references. */ 464 465 extern struct proto sctp_prot; 466 extern struct proto sctpv6_prot; 467 void sctp_put_port(struct sock *sk); 468 469 extern struct idr sctp_assocs_id; 470 extern spinlock_t sctp_assocs_id_lock; 471 472 /* Static inline functions. */ 473 474 /* Convert from an IP version number to an Address Family symbol. */ 475 static inline int ipver2af(__u8 ipver) 476 { 477 switch (ipver) { 478 case 4: 479 return AF_INET; 480 case 6: 481 return AF_INET6; 482 default: 483 return 0; 484 } 485 } 486 487 /* Convert from an address parameter type to an address family. */ 488 static inline int param_type2af(__be16 type) 489 { 490 switch (type) { 491 case SCTP_PARAM_IPV4_ADDRESS: 492 return AF_INET; 493 case SCTP_PARAM_IPV6_ADDRESS: 494 return AF_INET6; 495 default: 496 return 0; 497 } 498 } 499 500 /* Warning: The following hash functions assume a power of two 'size'. */ 501 /* This is the hash function for the SCTP port hash table. */ 502 static inline int sctp_phashfn(struct net *net, __u16 lport) 503 { 504 return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1); 505 } 506 507 /* This is the hash function for the endpoint hash table. */ 508 static inline int sctp_ep_hashfn(struct net *net, __u16 lport) 509 { 510 return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1); 511 } 512 513 #define sctp_for_each_hentry(epb, head) \ 514 hlist_for_each_entry(epb, head, node) 515 516 /* Is a socket of this style? */ 517 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style)) 518 static inline int __sctp_style(const struct sock *sk, 519 enum sctp_socket_type style) 520 { 521 return sctp_sk(sk)->type == style; 522 } 523 524 /* Is the association in this state? */ 525 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state)) 526 static inline int __sctp_state(const struct sctp_association *asoc, 527 enum sctp_state state) 528 { 529 return asoc->state == state; 530 } 531 532 /* Is the socket in this state? */ 533 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state)) 534 static inline int __sctp_sstate(const struct sock *sk, 535 enum sctp_sock_state state) 536 { 537 return sk->sk_state == state; 538 } 539 540 /* Map v4-mapped v6 address back to v4 address */ 541 static inline void sctp_v6_map_v4(union sctp_addr *addr) 542 { 543 addr->v4.sin_family = AF_INET; 544 addr->v4.sin_port = addr->v6.sin6_port; 545 addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3]; 546 } 547 548 /* Map v4 address to v4-mapped v6 address */ 549 static inline void sctp_v4_map_v6(union sctp_addr *addr) 550 { 551 __be16 port; 552 553 port = addr->v4.sin_port; 554 addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 555 addr->v6.sin6_port = port; 556 addr->v6.sin6_family = AF_INET6; 557 addr->v6.sin6_flowinfo = 0; 558 addr->v6.sin6_scope_id = 0; 559 addr->v6.sin6_addr.s6_addr32[0] = 0; 560 addr->v6.sin6_addr.s6_addr32[1] = 0; 561 addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff); 562 } 563 564 /* The cookie is always 0 since this is how it's used in the 565 * pmtu code. 566 */ 567 static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t) 568 { 569 if (t->dst && !dst_check(t->dst, t->dst_cookie)) 570 sctp_transport_dst_release(t); 571 572 return t->dst; 573 } 574 575 /* Calculate max payload size given a MTU, or the total overhead if 576 * given MTU is zero 577 */ 578 static inline __u32 __sctp_mtu_payload(const struct sctp_sock *sp, 579 const struct sctp_transport *t, 580 __u32 mtu, __u32 extra) 581 { 582 __u32 overhead = sizeof(struct sctphdr) + extra; 583 584 if (sp) { 585 overhead += sp->pf->af->net_header_len; 586 if (sp->udp_port && (!t || t->encap_port)) 587 overhead += sizeof(struct udphdr); 588 } else { 589 overhead += sizeof(struct ipv6hdr); 590 } 591 592 if (WARN_ON_ONCE(mtu && mtu <= overhead)) 593 mtu = overhead; 594 595 return mtu ? mtu - overhead : overhead; 596 } 597 598 static inline __u32 sctp_mtu_payload(const struct sctp_sock *sp, 599 __u32 mtu, __u32 extra) 600 { 601 return __sctp_mtu_payload(sp, NULL, mtu, extra); 602 } 603 604 static inline __u32 sctp_dst_mtu(const struct dst_entry *dst) 605 { 606 return SCTP_TRUNC4(max_t(__u32, dst_mtu(dst), 607 SCTP_DEFAULT_MINSEGMENT)); 608 } 609 610 static inline bool sctp_transport_pmtu_check(struct sctp_transport *t) 611 { 612 __u32 pmtu = sctp_dst_mtu(t->dst); 613 614 if (t->pathmtu == pmtu) 615 return true; 616 617 t->pathmtu = pmtu; 618 619 return false; 620 } 621 622 static inline __u32 sctp_min_frag_point(struct sctp_sock *sp, __u16 datasize) 623 { 624 return sctp_mtu_payload(sp, SCTP_DEFAULT_MINSEGMENT, datasize); 625 } 626 627 static inline int sctp_transport_pl_hlen(struct sctp_transport *t) 628 { 629 return __sctp_mtu_payload(sctp_sk(t->asoc->base.sk), t, 0, 0) - 630 sizeof(struct sctphdr); 631 } 632 633 static inline void sctp_transport_pl_reset(struct sctp_transport *t) 634 { 635 if (t->probe_interval && (t->param_flags & SPP_PMTUD_ENABLE) && 636 (t->state == SCTP_ACTIVE || t->state == SCTP_UNKNOWN)) { 637 if (t->pl.state == SCTP_PL_DISABLED) { 638 t->pl.state = SCTP_PL_BASE; 639 t->pl.pmtu = SCTP_BASE_PLPMTU; 640 t->pl.probe_size = SCTP_BASE_PLPMTU; 641 sctp_transport_reset_probe_timer(t); 642 } 643 } else { 644 if (t->pl.state != SCTP_PL_DISABLED) { 645 if (del_timer(&t->probe_timer)) 646 sctp_transport_put(t); 647 t->pl.state = SCTP_PL_DISABLED; 648 } 649 } 650 } 651 652 static inline void sctp_transport_pl_update(struct sctp_transport *t) 653 { 654 if (t->pl.state == SCTP_PL_DISABLED) 655 return; 656 657 t->pl.state = SCTP_PL_BASE; 658 t->pl.pmtu = SCTP_BASE_PLPMTU; 659 t->pl.probe_size = SCTP_BASE_PLPMTU; 660 sctp_transport_reset_probe_timer(t); 661 } 662 663 static inline bool sctp_transport_pl_enabled(struct sctp_transport *t) 664 { 665 return t->pl.state != SCTP_PL_DISABLED; 666 } 667 668 static inline bool sctp_newsk_ready(const struct sock *sk) 669 { 670 return sock_flag(sk, SOCK_DEAD) || sk->sk_socket; 671 } 672 673 static inline void sctp_sock_set_nodelay(struct sock *sk) 674 { 675 lock_sock(sk); 676 sctp_sk(sk)->nodelay = true; 677 release_sock(sk); 678 } 679 680 #endif /* __net_sctp_h__ */ 681