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/* 71 * Function declarations. 72 */ 73 74/* 75 * sctp/protocol.c 76 */ 77int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *addr, 78 enum sctp_scope, gfp_t gfp, int flags); 79struct sctp_pf *sctp_get_pf_specific(sa_family_t family); 80int sctp_register_pf(struct sctp_pf *, sa_family_t); 81void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int); 82int sctp_udp_sock_start(struct net *net); 83void sctp_udp_sock_stop(struct net *net); 84 85/* 86 * sctp/socket.c 87 */ 88int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr, 89 int addr_len, int flags); 90int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb); 91int sctp_inet_listen(struct socket *sock, int backlog); 92void sctp_write_space(struct sock *sk); 93void sctp_data_ready(struct sock *sk); 94__poll_t sctp_poll(struct file *file, struct socket *sock, 95 poll_table *wait); 96void sctp_sock_rfree(struct sk_buff *skb); 97void sctp_copy_sock(struct sock *newsk, struct sock *sk, 98 struct sctp_association *asoc); 99extern struct percpu_counter sctp_sockets_allocated; 100int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *); 101struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int *); 102 103typedef int (*sctp_callback_t)(struct sctp_endpoint *, struct sctp_transport *, void *); 104void sctp_transport_walk_start(struct rhashtable_iter *iter); 105void sctp_transport_walk_stop(struct rhashtable_iter *iter); 106struct sctp_transport *sctp_transport_get_next(struct net *net, 107 struct rhashtable_iter *iter); 108struct sctp_transport *sctp_transport_get_idx(struct net *net, 109 struct rhashtable_iter *iter, int pos); 110int sctp_transport_lookup_process(sctp_callback_t cb, struct net *net, 111 const union sctp_addr *laddr, 112 const union sctp_addr *paddr, void *p, int dif); 113int sctp_transport_traverse_process(sctp_callback_t cb, sctp_callback_t cb_done, 114 struct net *net, int *pos, void *p); 115int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p); 116int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc, 117 struct sctp_info *info); 118 119/* 120 * sctp/primitive.c 121 */ 122int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg); 123int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg); 124int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg); 125int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg); 126int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg); 127int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg); 128int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc, 129 void *arg); 130 131/* 132 * sctp/input.c 133 */ 134int sctp_rcv(struct sk_buff *skb); 135int sctp_v4_err(struct sk_buff *skb, u32 info); 136int sctp_hash_endpoint(struct sctp_endpoint *ep); 137void sctp_unhash_endpoint(struct sctp_endpoint *); 138struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *, 139 struct sctphdr *, struct sctp_association **, 140 struct sctp_transport **); 141void sctp_err_finish(struct sock *, struct sctp_transport *); 142int sctp_udp_v4_err(struct sock *sk, struct sk_buff *skb); 143int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb); 144void sctp_icmp_frag_needed(struct sock *, struct sctp_association *, 145 struct sctp_transport *t, __u32 pmtu); 146void sctp_icmp_redirect(struct sock *, struct sctp_transport *, 147 struct sk_buff *); 148void sctp_icmp_proto_unreachable(struct sock *sk, 149 struct sctp_association *asoc, 150 struct sctp_transport *t); 151int sctp_transport_hashtable_init(void); 152void sctp_transport_hashtable_destroy(void); 153int sctp_hash_transport(struct sctp_transport *t); 154void sctp_unhash_transport(struct sctp_transport *t); 155struct sctp_transport *sctp_addrs_lookup_transport( 156 struct net *net, 157 const union sctp_addr *laddr, 158 const union sctp_addr *paddr, 159 int dif, int sdif); 160struct sctp_transport *sctp_epaddr_lookup_transport( 161 const struct sctp_endpoint *ep, 162 const union sctp_addr *paddr); 163bool sctp_sk_bound_dev_eq(struct net *net, int bound_dev_if, int dif, int sdif); 164 165/* 166 * sctp/proc.c 167 */ 168int __net_init sctp_proc_init(struct net *net); 169 170/* 171 * sctp/offload.c 172 */ 173int sctp_offload_init(void); 174 175/* 176 * sctp/stream_sched.c 177 */ 178void sctp_sched_ops_init(void); 179 180/* 181 * sctp/stream.c 182 */ 183int sctp_send_reset_streams(struct sctp_association *asoc, 184 struct sctp_reset_streams *params); 185int sctp_send_reset_assoc(struct sctp_association *asoc); 186int sctp_send_add_streams(struct sctp_association *asoc, 187 struct sctp_add_streams *params); 188 189/* 190 * Module global variables 191 */ 192 193 /* 194 * sctp/protocol.c 195 */ 196extern struct kmem_cache *sctp_chunk_cachep __read_mostly; 197extern struct kmem_cache *sctp_bucket_cachep __read_mostly; 198extern long sysctl_sctp_mem[3]; 199extern int sysctl_sctp_rmem[3]; 200extern int sysctl_sctp_wmem[3]; 201 202/* 203 * Section: Macros, externs, and inlines 204 */ 205 206/* SCTP SNMP MIB stats handlers */ 207#define SCTP_INC_STATS(net, field) SNMP_INC_STATS((net)->sctp.sctp_statistics, field) 208#define __SCTP_INC_STATS(net, field) __SNMP_INC_STATS((net)->sctp.sctp_statistics, field) 209#define SCTP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->sctp.sctp_statistics, field) 210 211/* sctp mib definitions */ 212enum { 213 SCTP_MIB_NUM = 0, 214 SCTP_MIB_CURRESTAB, /* CurrEstab */ 215 SCTP_MIB_ACTIVEESTABS, /* ActiveEstabs */ 216 SCTP_MIB_PASSIVEESTABS, /* PassiveEstabs */ 217 SCTP_MIB_ABORTEDS, /* Aborteds */ 218 SCTP_MIB_SHUTDOWNS, /* Shutdowns */ 219 SCTP_MIB_OUTOFBLUES, /* OutOfBlues */ 220 SCTP_MIB_CHECKSUMERRORS, /* ChecksumErrors */ 221 SCTP_MIB_OUTCTRLCHUNKS, /* OutCtrlChunks */ 222 SCTP_MIB_OUTORDERCHUNKS, /* OutOrderChunks */ 223 SCTP_MIB_OUTUNORDERCHUNKS, /* OutUnorderChunks */ 224 SCTP_MIB_INCTRLCHUNKS, /* InCtrlChunks */ 225 SCTP_MIB_INORDERCHUNKS, /* InOrderChunks */ 226 SCTP_MIB_INUNORDERCHUNKS, /* InUnorderChunks */ 227 SCTP_MIB_FRAGUSRMSGS, /* FragUsrMsgs */ 228 SCTP_MIB_REASMUSRMSGS, /* ReasmUsrMsgs */ 229 SCTP_MIB_OUTSCTPPACKS, /* OutSCTPPacks */ 230 SCTP_MIB_INSCTPPACKS, /* InSCTPPacks */ 231 SCTP_MIB_T1_INIT_EXPIREDS, 232 SCTP_MIB_T1_COOKIE_EXPIREDS, 233 SCTP_MIB_T2_SHUTDOWN_EXPIREDS, 234 SCTP_MIB_T3_RTX_EXPIREDS, 235 SCTP_MIB_T4_RTO_EXPIREDS, 236 SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS, 237 SCTP_MIB_DELAY_SACK_EXPIREDS, 238 SCTP_MIB_AUTOCLOSE_EXPIREDS, 239 SCTP_MIB_T1_RETRANSMITS, 240 SCTP_MIB_T3_RETRANSMITS, 241 SCTP_MIB_PMTUD_RETRANSMITS, 242 SCTP_MIB_FAST_RETRANSMITS, 243 SCTP_MIB_IN_PKT_SOFTIRQ, 244 SCTP_MIB_IN_PKT_BACKLOG, 245 SCTP_MIB_IN_PKT_DISCARDS, 246 SCTP_MIB_IN_DATA_CHUNK_DISCARDS, 247 __SCTP_MIB_MAX 248}; 249 250#define SCTP_MIB_MAX __SCTP_MIB_MAX 251struct sctp_mib { 252 unsigned long mibs[SCTP_MIB_MAX]; 253}; 254 255/* helper function to track stats about max rto and related transport */ 256static inline void sctp_max_rto(struct sctp_association *asoc, 257 struct sctp_transport *trans) 258{ 259 if (asoc->stats.max_obs_rto < (__u64)trans->rto) { 260 asoc->stats.max_obs_rto = trans->rto; 261 memset(&asoc->stats.obs_rto_ipaddr, 0, 262 sizeof(struct sockaddr_storage)); 263 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr, 264 trans->af_specific->sockaddr_len); 265 } 266} 267 268/* 269 * Macros for keeping a global reference of object allocations. 270 */ 271#ifdef CONFIG_SCTP_DBG_OBJCNT 272 273extern atomic_t sctp_dbg_objcnt_sock; 274extern atomic_t sctp_dbg_objcnt_ep; 275extern atomic_t sctp_dbg_objcnt_assoc; 276extern atomic_t sctp_dbg_objcnt_transport; 277extern atomic_t sctp_dbg_objcnt_chunk; 278extern atomic_t sctp_dbg_objcnt_bind_addr; 279extern atomic_t sctp_dbg_objcnt_bind_bucket; 280extern atomic_t sctp_dbg_objcnt_addr; 281extern atomic_t sctp_dbg_objcnt_datamsg; 282extern atomic_t sctp_dbg_objcnt_keys; 283 284/* Macros to atomically increment/decrement objcnt counters. */ 285#define SCTP_DBG_OBJCNT_INC(name) \ 286atomic_inc(&sctp_dbg_objcnt_## name) 287#define SCTP_DBG_OBJCNT_DEC(name) \ 288atomic_dec(&sctp_dbg_objcnt_## name) 289#define SCTP_DBG_OBJCNT(name) \ 290atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0) 291 292/* Macro to help create new entries in the global array of 293 * objcnt counters. 294 */ 295#define SCTP_DBG_OBJCNT_ENTRY(name) \ 296{.label= #name, .counter= &sctp_dbg_objcnt_## name} 297 298void sctp_dbg_objcnt_init(struct net *); 299 300#else 301 302#define SCTP_DBG_OBJCNT_INC(name) 303#define SCTP_DBG_OBJCNT_DEC(name) 304 305static inline void sctp_dbg_objcnt_init(struct net *net) { return; } 306 307#endif /* CONFIG_SCTP_DBG_OBJCOUNT */ 308 309#if defined CONFIG_SYSCTL 310void sctp_sysctl_register(void); 311void sctp_sysctl_unregister(void); 312int sctp_sysctl_net_register(struct net *net); 313void sctp_sysctl_net_unregister(struct net *net); 314#else 315static inline void sctp_sysctl_register(void) { return; } 316static inline void sctp_sysctl_unregister(void) { return; } 317static inline int sctp_sysctl_net_register(struct net *net) { return 0; } 318static inline void sctp_sysctl_net_unregister(struct net *net) { return; } 319#endif 320 321/* Size of Supported Address Parameter for 'x' address types. */ 322#define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16)) 323 324#if IS_ENABLED(CONFIG_IPV6) 325 326void sctp_v6_pf_init(void); 327void sctp_v6_pf_exit(void); 328int sctp_v6_protosw_init(void); 329void sctp_v6_protosw_exit(void); 330int sctp_v6_add_protocol(void); 331void sctp_v6_del_protocol(void); 332 333#else /* #ifdef defined(CONFIG_IPV6) */ 334 335static inline void sctp_v6_pf_init(void) { return; } 336static inline void sctp_v6_pf_exit(void) { return; } 337static inline int sctp_v6_protosw_init(void) { return 0; } 338static inline void sctp_v6_protosw_exit(void) { return; } 339static inline int sctp_v6_add_protocol(void) { return 0; } 340static inline void sctp_v6_del_protocol(void) { return; } 341 342#endif /* #if defined(CONFIG_IPV6) */ 343 344 345/* Map an association to an assoc_id. */ 346static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc) 347{ 348 return asoc ? asoc->assoc_id : 0; 349} 350 351static inline enum sctp_sstat_state 352sctp_assoc_to_state(const struct sctp_association *asoc) 353{ 354 /* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we 355 * got rid of it in kernel space. Therefore SCTP_CLOSED et al 356 * start at =1 in user space, but actually as =0 in kernel space. 357 * Now that we can not break user space and SCTP_EMPTY is exposed 358 * there, we need to fix it up with an ugly offset not to break 359 * applications. :( 360 */ 361 return asoc->state + 1; 362} 363 364/* Look up the association by its id. */ 365struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id); 366 367int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp); 368 369/* A macro to walk a list of skbs. */ 370#define sctp_skb_for_each(pos, head, tmp) \ 371 skb_queue_walk_safe(head, pos, tmp) 372 373/** 374 * sctp_list_dequeue - remove from the head of the queue 375 * @list: list to dequeue from 376 * 377 * Remove the head of the list. The head item is 378 * returned or %NULL if the list is empty. 379 */ 380 381static inline struct list_head *sctp_list_dequeue(struct list_head *list) 382{ 383 struct list_head *result = NULL; 384 385 if (!list_empty(list)) { 386 result = list->next; 387 list_del_init(result); 388 } 389 return result; 390} 391 392/* SCTP version of skb_set_owner_r. We need this one because 393 * of the way we have to do receive buffer accounting on bundled 394 * chunks. 395 */ 396static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 397{ 398 struct sctp_ulpevent *event = sctp_skb2event(skb); 399 400 skb_orphan(skb); 401 skb->sk = sk; 402 skb->destructor = sctp_sock_rfree; 403 atomic_add(event->rmem_len, &sk->sk_rmem_alloc); 404 /* 405 * This mimics the behavior of skb_set_owner_r 406 */ 407 sk_mem_charge(sk, event->rmem_len); 408} 409 410/* Tests if the list has one and only one entry. */ 411static inline int sctp_list_single_entry(struct list_head *head) 412{ 413 return list_is_singular(head); 414} 415 416static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk) 417{ 418 return !list_empty(&chunk->list); 419} 420 421/* Walk through a list of TLV parameters. Don't trust the 422 * individual parameter lengths and instead depend on 423 * the chunk length to indicate when to stop. Make sure 424 * there is room for a param header too. 425 */ 426#define sctp_walk_params(pos, chunk)\ 427_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length)) 428 429#define _sctp_walk_params(pos, chunk, end)\ 430for (pos.v = (u8 *)(chunk + 1);\ 431 (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\ 432 (void *)chunk + end) &&\ 433 pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\ 434 ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\ 435 pos.v += SCTP_PAD4(ntohs(pos.p->length))) 436 437#define sctp_walk_errors(err, chunk_hdr)\ 438_sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length)) 439 440#define _sctp_walk_errors(err, chunk_hdr, end)\ 441for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \ 442 sizeof(struct sctp_chunkhdr));\ 443 ((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\ 444 (void *)chunk_hdr + end) &&\ 445 (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\ 446 ntohs(err->length) >= sizeof(struct sctp_errhdr); \ 447 err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length)))) 448 449#define sctp_walk_fwdtsn(pos, chunk)\ 450_sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk)) 451 452#define _sctp_walk_fwdtsn(pos, chunk, end)\ 453for (pos = (void *)(chunk->subh.fwdtsn_hdr + 1);\ 454 (void *)pos <= (void *)(chunk->subh.fwdtsn_hdr + 1) + end - sizeof(struct sctp_fwdtsn_skip);\ 455 pos++) 456 457/* External references. */ 458 459extern struct proto sctp_prot; 460extern struct proto sctpv6_prot; 461void sctp_put_port(struct sock *sk); 462 463extern struct idr sctp_assocs_id; 464extern spinlock_t sctp_assocs_id_lock; 465 466/* Static inline functions. */ 467 468/* Convert from an IP version number to an Address Family symbol. */ 469static inline int ipver2af(__u8 ipver) 470{ 471 switch (ipver) { 472 case 4: 473 return AF_INET; 474 case 6: 475 return AF_INET6; 476 default: 477 return 0; 478 } 479} 480 481/* Convert from an address parameter type to an address family. */ 482static inline int param_type2af(__be16 type) 483{ 484 switch (type) { 485 case SCTP_PARAM_IPV4_ADDRESS: 486 return AF_INET; 487 case SCTP_PARAM_IPV6_ADDRESS: 488 return AF_INET6; 489 default: 490 return 0; 491 } 492} 493 494/* Warning: The following hash functions assume a power of two 'size'. */ 495/* This is the hash function for the SCTP port hash table. */ 496static inline int sctp_phashfn(struct net *net, __u16 lport) 497{ 498 return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1); 499} 500 501/* This is the hash function for the endpoint hash table. */ 502static inline int sctp_ep_hashfn(struct net *net, __u16 lport) 503{ 504 return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1); 505} 506 507#define sctp_for_each_hentry(ep, head) \ 508 hlist_for_each_entry(ep, head, node) 509 510/* Is a socket of this style? */ 511#define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style)) 512static inline int __sctp_style(const struct sock *sk, 513 enum sctp_socket_type style) 514{ 515 return sctp_sk(sk)->type == style; 516} 517 518/* Is the association in this state? */ 519#define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state)) 520static inline int __sctp_state(const struct sctp_association *asoc, 521 enum sctp_state state) 522{ 523 return asoc->state == state; 524} 525 526/* Is the socket in this state? */ 527#define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state)) 528static inline int __sctp_sstate(const struct sock *sk, 529 enum sctp_sock_state state) 530{ 531 return sk->sk_state == state; 532} 533 534/* Map v4-mapped v6 address back to v4 address */ 535static inline void sctp_v6_map_v4(union sctp_addr *addr) 536{ 537 addr->v4.sin_family = AF_INET; 538 addr->v4.sin_port = addr->v6.sin6_port; 539 addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3]; 540} 541 542/* Map v4 address to v4-mapped v6 address */ 543static inline void sctp_v4_map_v6(union sctp_addr *addr) 544{ 545 __be16 port; 546 547 port = addr->v4.sin_port; 548 addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 549 addr->v6.sin6_port = port; 550 addr->v6.sin6_family = AF_INET6; 551 addr->v6.sin6_flowinfo = 0; 552 addr->v6.sin6_scope_id = 0; 553 addr->v6.sin6_addr.s6_addr32[0] = 0; 554 addr->v6.sin6_addr.s6_addr32[1] = 0; 555 addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff); 556} 557 558/* The cookie is always 0 since this is how it's used in the 559 * pmtu code. 560 */ 561static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t) 562{ 563 if (t->dst && !dst_check(t->dst, t->dst_cookie)) 564 sctp_transport_dst_release(t); 565 566 return t->dst; 567} 568 569/* Calculate max payload size given a MTU, or the total overhead if 570 * given MTU is zero 571 */ 572static inline __u32 __sctp_mtu_payload(const struct sctp_sock *sp, 573 const struct sctp_transport *t, 574 __u32 mtu, __u32 extra) 575{ 576 __u32 overhead = sizeof(struct sctphdr) + extra; 577 578 if (sp) { 579 overhead += sp->pf->af->net_header_len; 580 if (sp->udp_port && (!t || t->encap_port)) 581 overhead += sizeof(struct udphdr); 582 } else { 583 overhead += sizeof(struct ipv6hdr); 584 } 585 586 if (WARN_ON_ONCE(mtu && mtu <= overhead)) 587 mtu = overhead; 588 589 return mtu ? mtu - overhead : overhead; 590} 591 592static inline __u32 sctp_mtu_payload(const struct sctp_sock *sp, 593 __u32 mtu, __u32 extra) 594{ 595 return __sctp_mtu_payload(sp, NULL, mtu, extra); 596} 597 598static inline __u32 sctp_dst_mtu(const struct dst_entry *dst) 599{ 600 return SCTP_TRUNC4(max_t(__u32, dst_mtu(dst), 601 SCTP_DEFAULT_MINSEGMENT)); 602} 603 604static inline bool sctp_transport_pmtu_check(struct sctp_transport *t) 605{ 606 __u32 pmtu = sctp_dst_mtu(t->dst); 607 608 if (t->pathmtu == pmtu) 609 return true; 610 611 t->pathmtu = pmtu; 612 613 return false; 614} 615 616static inline __u32 sctp_min_frag_point(struct sctp_sock *sp, __u16 datasize) 617{ 618 return sctp_mtu_payload(sp, SCTP_DEFAULT_MINSEGMENT, datasize); 619} 620 621static inline int sctp_transport_pl_hlen(struct sctp_transport *t) 622{ 623 return __sctp_mtu_payload(sctp_sk(t->asoc->base.sk), t, 0, 0) - 624 sizeof(struct sctphdr); 625} 626 627static inline void sctp_transport_pl_reset(struct sctp_transport *t) 628{ 629 if (t->probe_interval && (t->param_flags & SPP_PMTUD_ENABLE) && 630 (t->state == SCTP_ACTIVE || t->state == SCTP_UNKNOWN)) { 631 if (t->pl.state == SCTP_PL_DISABLED) { 632 t->pl.state = SCTP_PL_BASE; 633 t->pl.pmtu = SCTP_BASE_PLPMTU; 634 t->pl.probe_size = SCTP_BASE_PLPMTU; 635 sctp_transport_reset_probe_timer(t); 636 } 637 } else { 638 if (t->pl.state != SCTP_PL_DISABLED) { 639 if (del_timer(&t->probe_timer)) 640 sctp_transport_put(t); 641 t->pl.state = SCTP_PL_DISABLED; 642 } 643 } 644} 645 646static inline void sctp_transport_pl_update(struct sctp_transport *t) 647{ 648 if (t->pl.state == SCTP_PL_DISABLED) 649 return; 650 651 t->pl.state = SCTP_PL_BASE; 652 t->pl.pmtu = SCTP_BASE_PLPMTU; 653 t->pl.probe_size = SCTP_BASE_PLPMTU; 654 sctp_transport_reset_probe_timer(t); 655} 656 657static inline bool sctp_transport_pl_enabled(struct sctp_transport *t) 658{ 659 return t->pl.state != SCTP_PL_DISABLED; 660} 661 662static inline bool sctp_newsk_ready(const struct sock *sk) 663{ 664 return sock_flag(sk, SOCK_DEAD) || sk->sk_socket; 665} 666 667static inline void sctp_sock_set_nodelay(struct sock *sk) 668{ 669 lock_sock(sk); 670 sctp_sk(sk)->nodelay = true; 671 release_sock(sk); 672} 673 674#endif /* __net_sctp_h__ */ 675