1/* SCTP kernel reference Implementation 2 * (C) Copyright IBM Corp. 2001, 2003 3 * Copyright (c) 1999-2000 Cisco, Inc. 4 * Copyright (c) 1999-2001 Motorola, Inc. 5 * Copyright (c) 2001 Intel Corp. 6 * 7 * This file is part of the SCTP kernel reference Implementation 8 * 9 * The SCTP reference implementation is free software; 10 * you can redistribute it and/or modify it under the terms of 11 * the GNU General Public License as published by 12 * the Free Software Foundation; either version 2, or (at your option) 13 * any later version. 14 * 15 * The SCTP reference implementation is distributed in the hope that it 16 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 17 * ************************ 18 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 19 * See the GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with GNU CC; see the file COPYING. If not, write to 23 * the Free Software Foundation, 59 Temple Place - Suite 330, 24 * Boston, MA 02111-1307, USA. 25 * 26 * Please send any bug reports or fixes you make to the 27 * email addresses: 28 * lksctp developers <lksctp-developers@lists.sourceforge.net> 29 * 30 * Or submit a bug report through the following website: 31 * http://www.sf.net/projects/lksctp 32 * 33 * Written or modified by: 34 * Randall Stewart <randall@sctp.chicago.il.us> 35 * Ken Morneau <kmorneau@cisco.com> 36 * Qiaobing Xie <qxie1@email.mot.com> 37 * La Monte H.P. Yarroll <piggy@acm.org> 38 * Karl Knutson <karl@athena.chicago.il.us> 39 * Jon Grimm <jgrimm@us.ibm.com> 40 * Xingang Guo <xingang.guo@intel.com> 41 * Hui Huang <hui.huang@nokia.com> 42 * Sridhar Samudrala <sri@us.ibm.com> 43 * Daisy Chang <daisyc@us.ibm.com> 44 * Dajiang Zhang <dajiang.zhang@nokia.com> 45 * Ardelle Fan <ardelle.fan@intel.com> 46 * Ryan Layer <rmlayer@us.ibm.com> 47 * Anup Pemmaiah <pemmaiah@cc.usu.edu> 48 * Kevin Gao <kevin.gao@intel.com> 49 * 50 * Any bugs reported given to us we will try to fix... any fixes shared will 51 * be incorporated into the next SCTP release. 52 */ 53 54#ifndef __sctp_structs_h__ 55#define __sctp_structs_h__ 56 57#include <linux/time.h> /* We get struct timespec. */ 58#include <linux/socket.h> /* linux/in.h needs this!! */ 59#include <linux/in.h> /* We get struct sockaddr_in. */ 60#include <linux/in6.h> /* We get struct in6_addr */ 61#include <asm/param.h> /* We get MAXHOSTNAMELEN. */ 62#include <asm/atomic.h> /* This gets us atomic counters. */ 63#include <linux/skbuff.h> /* We need sk_buff_head. */ 64#include <linux/tqueue.h> /* We need tq_struct. */ 65#include <linux/sctp.h> /* We need sctp* header structs. */ 66 67/* A convenience structure for handling sockaddr structures. 68 * We should wean ourselves off this. 69 */ 70union sctp_addr { 71 struct sockaddr_in v4; 72 struct sockaddr_in6 v6; 73 struct sockaddr sa; 74}; 75 76/* Forward declarations for data structures. */ 77struct sctp_globals; 78struct sctp_endpoint; 79struct sctp_association; 80struct sctp_transport; 81struct sctp_packet; 82struct sctp_chunk; 83struct sctp_inq; 84struct sctp_outq; 85struct sctp_bind_addr; 86struct sctp_ulpq; 87struct sctp_opt; 88struct sctp_ep_common; 89struct sctp_ssnmap; 90 91 92#include <net/sctp/compat.h> 93#include <net/sctp/tsnmap.h> 94#include <net/sctp/ulpevent.h> 95#include <net/sctp/ulpqueue.h> 96 97/* Structures useful for managing bind/connect. */ 98 99struct sctp_bind_bucket { 100 unsigned short port; 101 unsigned short fastreuse; 102 struct sctp_bind_bucket *next; 103 struct sctp_bind_bucket **pprev; 104 struct sock *sk; 105}; 106 107struct sctp_bind_hashbucket { 108 spinlock_t lock; 109 struct sctp_bind_bucket *chain; 110}; 111 112/* Used for hashing all associations. */ 113struct sctp_hashbucket { 114 rwlock_t lock; 115 struct sctp_ep_common *chain; 116} __attribute__((__aligned__(8))); 117 118 119/* The SCTP globals structure. */ 120extern struct sctp_globals { 121 /* RFC2960 Section 14. Suggested SCTP Protocol Parameter Values 122 * 123 * The following protocol parameters are RECOMMENDED: 124 * 125 * RTO.Initial - 3 seconds 126 * RTO.Min - 1 second 127 * RTO.Max - 60 seconds 128 * RTO.Alpha - 1/8 (3 when converted to right shifts.) 129 * RTO.Beta - 1/4 (2 when converted to right shifts.) 130 */ 131 __u32 rto_initial; 132 __u32 rto_min; 133 __u32 rto_max; 134 135 /* Note: rto_alpha and rto_beta are really defined as inverse 136 * powers of two to facilitate integer operations. 137 */ 138 int rto_alpha; 139 int rto_beta; 140 141 /* Max.Burst - 4 */ 142 int max_burst; 143 144 /* Valid.Cookie.Life - 60 seconds */ 145 int valid_cookie_life; 146 147 /* Whether Cookie Preservative is enabled(1) or not(0) */ 148 int cookie_preserve_enable; 149 150 /* Association.Max.Retrans - 10 attempts 151 * Path.Max.Retrans - 5 attempts (per destination address) 152 * Max.Init.Retransmits - 8 attempts 153 */ 154 int max_retrans_association; 155 int max_retrans_path; 156 int max_retrans_init; 157 158 /* HB.interval - 30 seconds */ 159 int hb_interval; 160 161 /* The following variables are implementation specific. */ 162 163 /* Default initialization values to be applied to new associations. */ 164 __u16 max_instreams; 165 __u16 max_outstreams; 166 167 /* This is a list of groups of functions for each address 168 * family that we support. 169 */ 170 struct list_head address_families; 171 172 /* This is the hash of all endpoints. */ 173 int ep_hashsize; 174 struct sctp_hashbucket *ep_hashtable; 175 176 /* This is the hash of all associations. */ 177 int assoc_hashsize; 178 struct sctp_hashbucket *assoc_hashtable; 179 180 /* This is the sctp port control hash. */ 181 int port_hashsize; 182 int port_rover; 183 spinlock_t port_alloc_lock; /* Protects port_rover. */ 184 struct sctp_bind_hashbucket *port_hashtable; 185 186 /* This is the global local address list. 187 * We actively maintain this complete list of interfaces on 188 * the system by catching routing events. 189 * 190 * It is a list of sctp_sockaddr_entry. 191 */ 192 struct list_head local_addr_list; 193 spinlock_t local_addr_lock; 194 195 /* Flag to indicate if addip is enabled. */ 196 int addip_enable; 197 198 /* Flag to indicate if PR-SCTP is enabled. */ 199 int prsctp_enable; 200} sctp_globals; 201 202#define sctp_rto_initial (sctp_globals.rto_initial) 203#define sctp_rto_min (sctp_globals.rto_min) 204#define sctp_rto_max (sctp_globals.rto_max) 205#define sctp_rto_alpha (sctp_globals.rto_alpha) 206#define sctp_rto_beta (sctp_globals.rto_beta) 207#define sctp_max_burst (sctp_globals.max_burst) 208#define sctp_valid_cookie_life (sctp_globals.valid_cookie_life) 209#define sctp_cookie_preserve_enable (sctp_globals.cookie_preserve_enable) 210#define sctp_max_retrans_association (sctp_globals.max_retrans_association) 211#define sctp_max_retrans_path (sctp_globals.max_retrans_path) 212#define sctp_max_retrans_init (sctp_globals.max_retrans_init) 213#define sctp_hb_interval (sctp_globals.hb_interval) 214#define sctp_max_instreams (sctp_globals.max_instreams) 215#define sctp_max_outstreams (sctp_globals.max_outstreams) 216#define sctp_address_families (sctp_globals.address_families) 217#define sctp_ep_hashsize (sctp_globals.ep_hashsize) 218#define sctp_ep_hashtable (sctp_globals.ep_hashtable) 219#define sctp_assoc_hashsize (sctp_globals.assoc_hashsize) 220#define sctp_assoc_hashtable (sctp_globals.assoc_hashtable) 221#define sctp_port_hashsize (sctp_globals.port_hashsize) 222#define sctp_port_rover (sctp_globals.port_rover) 223#define sctp_port_alloc_lock (sctp_globals.port_alloc_lock) 224#define sctp_port_hashtable (sctp_globals.port_hashtable) 225#define sctp_local_addr_list (sctp_globals.local_addr_list) 226#define sctp_local_addr_lock (sctp_globals.local_addr_lock) 227#define sctp_addip_enable (sctp_globals.addip_enable) 228#define sctp_prsctp_enable (sctp_globals.prsctp_enable) 229 230/* SCTP Socket type: UDP or TCP style. */ 231typedef enum { 232 SCTP_SOCKET_UDP = 0, 233 SCTP_SOCKET_UDP_HIGH_BANDWIDTH, 234 SCTP_SOCKET_TCP 235} sctp_socket_type_t; 236 237/* Per socket SCTP information. */ 238struct sctp_opt { 239 /* What kind of a socket is this? */ 240 sctp_socket_type_t type; 241 242 /* PF_ family specific functions. */ 243 struct sctp_pf *pf; 244 245 /* Access to HMAC transform. */ 246 struct crypto_tfm *hmac; 247 248 /* What is our base endpointer? */ 249 struct sctp_endpoint *ep; 250 251 /* Various Socket Options. */ 252 __u16 default_stream; 253 __u32 default_ppid; 254 __u16 default_flags; 255 __u32 default_context; 256 __u32 default_timetolive; 257 258 struct sctp_initmsg initmsg; 259 struct sctp_rtoinfo rtoinfo; 260 struct sctp_paddrparams paddrparam; 261 struct sctp_event_subscribe subscribe; 262 struct sctp_assocparams assocparams; 263 int user_frag; 264 __u32 autoclose; 265 __u8 nodelay; 266 __u8 disable_fragments; 267 __u8 pd_mode; 268 __u8 v4mapped; 269 __u32 adaption_ind; 270 271 /* Receive to here while partial delivery is in effect. */ 272 struct sk_buff_head pd_lobby; 273}; 274 275 276 277/* This is our APPLICATION-SPECIFIC state cookie. 278 * THIS IS NOT DICTATED BY THE SPECIFICATION. 279 */ 280/* These are the parts of an association which we send in the cookie. 281 * Most of these are straight out of: 282 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB) 283 * 284 */ 285 286struct sctp_cookie { 287 288 /* My : Tag expected in every inbound packet and sent 289 * Verification: in the INIT or INIT ACK chunk. 290 * Tag : 291 */ 292 __u32 my_vtag; 293 294 /* Peer's : Tag expected in every outbound packet except 295 * Verification: in the INIT chunk. 296 * Tag : 297 */ 298 __u32 peer_vtag; 299 300 /* The rest of these are not from the spec, but really need to 301 * be in the cookie. 302 */ 303 304 /* My Tie Tag : Assist in discovering a restarting association. */ 305 __u32 my_ttag; 306 307 /* Peer's Tie Tag: Assist in discovering a restarting association. */ 308 __u32 peer_ttag; 309 310 /* When does this cookie expire? */ 311 struct timeval expiration; 312 313 /* Number of inbound/outbound streams which are set 314 * and negotiated during the INIT process. 315 */ 316 __u16 sinit_num_ostreams; 317 __u16 sinit_max_instreams; 318 319 /* This is the first sequence number I used. */ 320 __u32 initial_tsn; 321 322 /* This holds the originating address of the INIT packet. */ 323 union sctp_addr peer_addr; 324 325 __u8 prsctp_capable; 326 327 __u32 adaption_ind; 328 329 /* This is a shim for my peer's INIT packet, followed by 330 * a copy of the raw address list of the association. 331 * The length of the raw address list is saved in the 332 * raw_addr_list_len field, which will be used at the time when 333 * the association TCB is re-constructed from the cookie. 334 */ 335 __u32 raw_addr_list_len; 336 struct sctp_init_chunk peer_init[0]; 337}; 338 339 340/* The format of our cookie that we send to our peer. */ 341struct sctp_signed_cookie { 342 __u8 signature[SCTP_SECRET_SIZE]; 343 struct sctp_cookie c; 344}; 345 346/* This is another convenience type to allocate memory for address 347 * params for the maximum size and pass such structures around 348 * internally. 349 */ 350union sctp_addr_param { 351 struct sctp_ipv4addr_param v4; 352 struct sctp_ipv6addr_param v6; 353}; 354 355/* A convenience type to allow walking through the various 356 * parameters and avoid casting all over the place. 357 */ 358union sctp_params { 359 void *v; 360 struct sctp_paramhdr *p; 361 struct sctp_cookie_preserve_param *life; 362 struct sctp_hostname_param *dns; 363 struct sctp_cookie_param *cookie; 364 struct sctp_supported_addrs_param *sat; 365 struct sctp_ipv4addr_param *v4; 366 struct sctp_ipv6addr_param *v6; 367 union sctp_addr_param *addr; 368 struct sctp_adaption_ind_param *aind; 369}; 370 371/* RFC 2960. Section 3.3.5 Heartbeat. 372 * Heartbeat Information: variable length 373 * The Sender-specific Heartbeat Info field should normally include 374 * information about the sender's current time when this HEARTBEAT 375 * chunk is sent and the destination transport address to which this 376 * HEARTBEAT is sent (see Section 8.3). 377 */ 378typedef struct sctp_sender_hb_info { 379 struct sctp_paramhdr param_hdr; 380 union sctp_addr daddr; 381 unsigned long sent_at; 382} __attribute__((packed)) sctp_sender_hb_info_t; 383 384/* 385 * RFC 2960 1.3.2 Sequenced Delivery within Streams 386 * 387 * The term "stream" is used in SCTP to refer to a sequence of user 388 * messages that are to be delivered to the upper-layer protocol in 389 * order with respect to other messages within the same stream. This is 390 * in contrast to its usage in TCP, where it refers to a sequence of 391 * bytes (in this document a byte is assumed to be eight bits). 392 * ... 393 * 394 * This is the structure we use to track both our outbound and inbound 395 * SSN, or Stream Sequence Numbers. 396 */ 397 398struct sctp_stream { 399 __u16 *ssn; 400 unsigned int len; 401}; 402 403struct sctp_ssnmap { 404 struct sctp_stream in; 405 struct sctp_stream out; 406 int malloced; 407}; 408 409struct sctp_ssnmap *sctp_ssnmap_init(struct sctp_ssnmap *, __u16, __u16); 410struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, int gfp); 411void sctp_ssnmap_free(struct sctp_ssnmap *map); 412void sctp_ssnmap_clear(struct sctp_ssnmap *map); 413 414/* What is the current SSN number for this stream? */ 415static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id) 416{ 417 return stream->ssn[id]; 418} 419 420/* Return the next SSN number for this stream. */ 421static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id) 422{ 423 return stream->ssn[id]++; 424} 425 426/* Skip over this ssn and all below. */ 427static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, 428 __u16 ssn) 429{ 430 stream->ssn[id] = ssn+1; 431} 432 433/* 434 * Pointers to address related SCTP functions. 435 * (i.e. things that depend on the address family.) 436 */ 437struct sctp_af { 438 int (*sctp_xmit) (struct sk_buff *skb, 439 struct sctp_transport *, 440 int ipfragok); 441 int (*setsockopt) (struct sock *sk, 442 int level, 443 int optname, 444 char *optval, 445 int optlen); 446 int (*getsockopt) (struct sock *sk, 447 int level, 448 int optname, 449 char *optval, 450 int *optlen); 451 struct dst_entry *(*get_dst) (struct sctp_association *asoc, 452 union sctp_addr *daddr, 453 union sctp_addr *saddr); 454 void (*get_saddr) (struct sctp_association *asoc, 455 struct dst_entry *dst, 456 union sctp_addr *daddr, 457 union sctp_addr *saddr); 458 void (*copy_addrlist) (struct list_head *, 459 struct net_device *); 460 void (*dst_saddr) (union sctp_addr *saddr, 461 struct dst_entry *dst, 462 unsigned short port); 463 int (*cmp_addr) (const union sctp_addr *addr1, 464 const union sctp_addr *addr2); 465 void (*addr_copy) (union sctp_addr *dst, 466 union sctp_addr *src); 467 void (*from_skb) (union sctp_addr *, 468 struct sk_buff *skb, 469 int saddr); 470 void (*from_sk) (union sctp_addr *, 471 struct sock *sk); 472 void (*to_sk_saddr) (union sctp_addr *, 473 struct sock *sk); 474 void (*to_sk_daddr) (union sctp_addr *, 475 struct sock *sk); 476 void (*from_addr_param) (union sctp_addr *, 477 union sctp_addr_param *, 478 __u16 port, int iif); 479 int (*to_addr_param) (const union sctp_addr *, 480 union sctp_addr_param *); 481 int (*addr_valid) (union sctp_addr *, 482 struct sctp_opt *); 483 sctp_scope_t (*scope) (union sctp_addr *); 484 void (*inaddr_any) (union sctp_addr *, unsigned short); 485 int (*is_any) (const union sctp_addr *); 486 int (*available) (union sctp_addr *, 487 struct sctp_opt *); 488 int (*skb_iif) (const struct sk_buff *sk); 489 int (*is_ce) (const struct sk_buff *sk); 490 void (*seq_dump_addr)(struct seq_file *seq, 491 union sctp_addr *addr); 492 __u16 net_header_len; 493 int sockaddr_len; 494 sa_family_t sa_family; 495 struct list_head list; 496}; 497 498struct sctp_af *sctp_get_af_specific(sa_family_t); 499int sctp_register_af(struct sctp_af *); 500 501/* Protocol family functions. */ 502struct sctp_pf { 503 void (*event_msgname)(struct sctp_ulpevent *, char *, int *); 504 void (*skb_msgname) (struct sk_buff *, char *, int *); 505 int (*af_supported) (sa_family_t, struct sctp_opt *); 506 int (*cmp_addr) (const union sctp_addr *, 507 const union sctp_addr *, 508 struct sctp_opt *); 509 int (*bind_verify) (struct sctp_opt *, union sctp_addr *); 510 int (*send_verify) (struct sctp_opt *, union sctp_addr *); 511 int (*supported_addrs)(const struct sctp_opt *, __u16 *); 512 struct sock *(*create_accept_sk) (struct sock *sk, 513 struct sctp_association *asoc); 514 void (*addr_v4map) (struct sctp_opt *, union sctp_addr *); 515 struct sctp_af *af; 516}; 517 518 519/* Structure to track chunk fragments that have been acked, but peer 520 * fragments of the same message have not. 521 */ 522struct sctp_datamsg { 523 /* Chunks waiting to be submitted to lower layer. */ 524 struct list_head chunks; 525 /* Chunks that have been transmitted. */ 526 struct list_head track; 527 /* Reference counting. */ 528 atomic_t refcnt; 529 /* When is this message no longer interesting to the peer? */ 530 unsigned long expires_at; 531 /* Did the messenge fail to send? */ 532 int send_error; 533 char send_failed; 534 /* Control whether chunks from this message can be abandoned. */ 535 char can_abandon; 536}; 537 538struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, 539 struct sctp_sndrcvinfo *, 540 struct msghdr *, int len); 541struct sctp_datamsg *sctp_datamsg_new(int gfp); 542void sctp_datamsg_put(struct sctp_datamsg *); 543void sctp_datamsg_hold(struct sctp_datamsg *); 544void sctp_datamsg_free(struct sctp_datamsg *); 545void sctp_datamsg_track(struct sctp_chunk *); 546void sctp_datamsg_assign(struct sctp_datamsg *, struct sctp_chunk *); 547void sctp_chunk_fail(struct sctp_chunk *, int error); 548int sctp_chunk_abandoned(struct sctp_chunk *); 549 550 551/* RFC2960 1.4 Key Terms 552 * 553 * o Chunk: A unit of information within an SCTP packet, consisting of 554 * a chunk header and chunk-specific content. 555 * 556 * As a matter of convenience, we remember the SCTP common header for 557 * each chunk as well as a few other header pointers... 558 */ 559struct sctp_chunk { 560 /* These first three elements MUST PRECISELY match the first 561 * three elements of struct sk_buff. This allows us to reuse 562 * all the skb_* queue management functions. 563 */ 564 struct sctp_chunk *next; 565 struct sctp_chunk *prev; 566 struct sk_buff_head *list; 567 atomic_t refcnt; 568 569 /* This is our link to the per-transport transmitted list. */ 570 struct list_head transmitted_list; 571 572 /* This field is used by chunks that hold fragmented data. 573 * For the first fragment this is the list that holds the rest of 574 * fragments. For the remaining fragments, this is the link to the 575 * frag_list maintained in the first fragment. 576 */ 577 struct list_head frag_list; 578 579 /* This points to the sk_buff containing the actual data. */ 580 struct sk_buff *skb; 581 582 /* These are the SCTP headers by reverse order in a packet. 583 * Note that some of these may happen more than once. In that 584 * case, we point at the "current" one, whatever that means 585 * for that level of header. 586 */ 587 588 /* We point this at the FIRST TLV parameter to chunk_hdr. */ 589 union sctp_params param_hdr; 590 union { 591 __u8 *v; 592 struct sctp_datahdr *data_hdr; 593 struct sctp_inithdr *init_hdr; 594 struct sctp_sackhdr *sack_hdr; 595 struct sctp_heartbeathdr *hb_hdr; 596 struct sctp_sender_hb_info *hbs_hdr; 597 struct sctp_shutdownhdr *shutdown_hdr; 598 struct sctp_signed_cookie *cookie_hdr; 599 struct sctp_ecnehdr *ecne_hdr; 600 struct sctp_cwrhdr *ecn_cwr_hdr; 601 struct sctp_errhdr *err_hdr; 602 struct sctp_addiphdr *addip_hdr; 603 struct sctp_fwdtsn_hdr *fwdtsn_hdr; 604 } subh; 605 606 __u8 *chunk_end; 607 608 struct sctp_chunkhdr *chunk_hdr; 609 struct sctphdr *sctp_hdr; 610 611 /* This needs to be recoverable for SCTP_SEND_FAILED events. */ 612 struct sctp_sndrcvinfo sinfo; 613 614 /* Which association does this belong to? */ 615 struct sctp_association *asoc; 616 617 /* What endpoint received this chunk? */ 618 struct sctp_ep_common *rcvr; 619 620 /* We fill this in if we are calculating RTT. */ 621 unsigned long sent_at; 622 623 /* What is the origin IP address for this chunk? */ 624 union sctp_addr source; 625 /* Destination address for this chunk. */ 626 union sctp_addr dest; 627 628 /* For outbound message, track all fragments for SEND_FAILED. */ 629 struct sctp_datamsg *msg; 630 631 /* For an inbound chunk, this tells us where it came from. 632 * For an outbound chunk, it tells us where we'd like it to 633 * go. It is NULL if we have no preference. 634 */ 635 struct sctp_transport *transport; 636 637 __u8 rtt_in_progress; /* Is this chunk used for RTT calculation? */ 638 __u8 resent; /* Has this chunk ever been retransmitted. */ 639 __u8 has_tsn; /* Does this chunk have a TSN yet? */ 640 __u8 has_ssn; /* Does this chunk have a SSN yet? */ 641 __u8 singleton; /* Was this the only chunk in the packet? */ 642 __u8 end_of_packet; /* Was this the last chunk in the packet? */ 643 __u8 ecn_ce_done; /* Have we processed the ECN CE bit? */ 644 __u8 pdiscard; /* Discard the whole packet now? */ 645 __u8 tsn_gap_acked; /* Is this chunk acked by a GAP ACK? */ 646 __u8 fast_retransmit; /* Is this chunk fast retransmitted? */ 647 __u8 tsn_missing_report; /* Data chunk missing counter. */ 648}; 649 650void sctp_chunk_hold(struct sctp_chunk *); 651void sctp_chunk_put(struct sctp_chunk *); 652int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 653 struct iovec *data); 654struct sctp_chunk *sctp_make_chunk(const struct sctp_association *, __u8 type, 655 __u8 flags, int size); 656void sctp_chunk_free(struct sctp_chunk *); 657void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); 658struct sctp_chunk *sctp_chunkify(struct sk_buff *, 659 const struct sctp_association *, 660 struct sock *); 661void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, 662 union sctp_addr *); 663const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); 664 665/* This is a structure for holding either an IPv6 or an IPv4 address. */ 666/* sin_family -- AF_INET or AF_INET6 667 * sin_port -- ordinary port number 668 * sin_addr -- cast to either (struct in_addr) or (struct in6_addr) 669 */ 670struct sctp_sockaddr_entry { 671 struct list_head list; 672 union sctp_addr a; 673}; 674 675typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *); 676 677/* This structure holds lists of chunks as we are assembling for 678 * transmission. 679 */ 680struct sctp_packet { 681 /* These are the SCTP header values (host order) for the packet. */ 682 __u16 source_port; 683 __u16 destination_port; 684 __u32 vtag; 685 686 /* This contains the payload chunks. */ 687 struct sk_buff_head chunks; 688 689 /* This is the overhead of the sctp and ip headers. */ 690 size_t overhead; 691 /* This is the total size of all chunks INCLUDING padding. */ 692 size_t size; 693 694 /* The packet is destined for this transport address. 695 * The function we finally use to pass down to the next lower 696 * layer lives in the transport structure. 697 */ 698 struct sctp_transport *transport; 699 700 /* This packet contains a COOKIE-ECHO chunk. */ 701 char has_cookie_echo; 702 703 /* This packet containsa SACK chunk. */ 704 char has_sack; 705 706 /* SCTP cannot fragment this packet. So let ip fragment it. */ 707 char ipfragok; 708 709 int malloced; 710}; 711 712struct sctp_packet *sctp_packet_init(struct sctp_packet *, 713 struct sctp_transport *, 714 __u16 sport, __u16 dport); 715struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int); 716sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *, 717 struct sctp_chunk *); 718sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *, 719 struct sctp_chunk *); 720int sctp_packet_transmit(struct sctp_packet *); 721void sctp_packet_free(struct sctp_packet *); 722 723static inline int sctp_packet_empty(struct sctp_packet *packet) 724{ 725 return (packet->size == packet->overhead); 726} 727 728/* This represents a remote transport address. 729 * For local transport addresses, we just use union sctp_addr. 730 * 731 * RFC2960 Section 1.4 Key Terms 732 * 733 * o Transport address: A Transport Address is traditionally defined 734 * by Network Layer address, Transport Layer protocol and Transport 735 * Layer port number. In the case of SCTP running over IP, a 736 * transport address is defined by the combination of an IP address 737 * and an SCTP port number (where SCTP is the Transport protocol). 738 * 739 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control 740 * 741 * o The sender keeps a separate congestion control parameter set for 742 * each of the destination addresses it can send to (not each 743 * source-destination pair but for each destination). The parameters 744 * should decay if the address is not used for a long enough time 745 * period. 746 * 747 */ 748struct sctp_transport { 749 /* A list of transports. */ 750 struct list_head transports; 751 752 /* Reference counting. */ 753 atomic_t refcnt; 754 int dead; 755 756 /* This is the peer's IP address and port. */ 757 union sctp_addr ipaddr; 758 759 /* These are the functions we call to handle LLP stuff. */ 760 struct sctp_af *af_specific; 761 762 /* Which association do we belong to? */ 763 struct sctp_association *asoc; 764 765 /* RFC2960 766 * 767 * 12.3 Per Transport Address Data 768 * 769 * For each destination transport address in the peer's 770 * address list derived from the INIT or INIT ACK chunk, a 771 * number of data elements needs to be maintained including: 772 */ 773 __u32 rtt; /* This is the most recent RTT. */ 774 775 /* RTO : The current retransmission timeout value. */ 776 __u32 rto; 777 778 /* RTTVAR : The current RTT variation. */ 779 __u32 rttvar; 780 781 /* SRTT : The current smoothed round trip time. */ 782 __u32 srtt; 783 784 /* RTO-Pending : A flag used to track if one of the DATA 785 * chunks sent to this address is currently being 786 * used to compute a RTT. If this flag is 0, 787 * the next DATA chunk sent to this destination 788 * should be used to compute a RTT and this flag 789 * should be set. Every time the RTT 790 * calculation completes (i.e. the DATA chunk 791 * is SACK'd) clear this flag. 792 */ 793 int rto_pending; 794 795 /* 796 * These are the congestion stats. 797 */ 798 /* cwnd : The current congestion window. */ 799 __u32 cwnd; /* This is the actual cwnd. */ 800 801 /* ssthresh : The current slow start threshold value. */ 802 __u32 ssthresh; 803 804 /* partial : The tracking method for increase of cwnd when in 805 * bytes acked : congestion avoidance mode (see Section 6.2.2) 806 */ 807 __u32 partial_bytes_acked; 808 809 /* Data that has been sent, but not acknowledged. */ 810 __u32 flight_size; 811 812 /* PMTU : The current known path MTU. */ 813 __u32 pmtu; 814 815 /* Destination */ 816 struct dst_entry *dst; 817 /* Source address. */ 818 union sctp_addr saddr; 819 820 /* When was the last time(in jiffies) that a data packet was sent on 821 * this transport? This is used to adjust the cwnd when the transport 822 * becomes inactive. 823 */ 824 unsigned long last_time_used; 825 826 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 827 * the destination address every heartbeat interval. 828 */ 829 int hb_interval; 830 831 /* When was the last time (in jiffies) that we heard from this 832 * transport? We use this to pick new active and retran paths. 833 */ 834 unsigned long last_time_heard; 835 836 /* Last time(in jiffies) when cwnd is reduced due to the congestion 837 * indication based on ECNE chunk. 838 */ 839 unsigned long last_time_ecne_reduced; 840 841 /* active : The current active state of this destination, 842 * : i.e. DOWN, UP, etc. 843 */ 844 int active; 845 846 /* hb_allowed : The current heartbeat state of this destination, 847 * : i.e. ALLOW-HB, NO-HEARTBEAT, etc. 848 */ 849 int hb_allowed; 850 851 /* These are the error stats for this destination. */ 852 853 /* Error count : The current error count for this destination. */ 854 unsigned short error_count; 855 856 /* Error : Current error threshold for this destination 857 * Threshold : i.e. what value marks the destination down if 858 * : errorCount reaches this value. 859 */ 860 unsigned short error_threshold; 861 862 /* This is the max_retrans value for the transport and will 863 * be initialized to proto.max_retrans.path. This can be changed 864 * using SCTP_SET_PEER_ADDR_PARAMS socket option. 865 */ 866 int max_retrans; 867 868 /* Per : A timer used by each destination. 869 * Destination : 870 * Timer : 871 * 872 * [Everywhere else in the text this is called T3-rtx. -ed] 873 */ 874 struct timer_list T3_rtx_timer; 875 876 /* Heartbeat timer is per destination. */ 877 struct timer_list hb_timer; 878 879 /* Since we're using per-destination retransmission timers 880 * (see above), we're also using per-destination "transmitted" 881 * queues. This probably ought to be a private struct 882 * accessible only within the outqueue, but it's not, yet. 883 */ 884 struct list_head transmitted; 885 886 /* We build bundle-able packets for this transport here. */ 887 struct sctp_packet packet; 888 889 /* This is the list of transports that have chunks to send. */ 890 struct list_head send_ready; 891 892 int malloced; /* Is this structure kfree()able? */ 893 894 /* State information saved for SFR_CACC algorithm. The key 895 * idea in SFR_CACC is to maintain state at the sender on a 896 * per-destination basis when a changeover happens. 897 * char changeover_active; 898 * char cycling_changeover; 899 * __u32 next_tsn_at_change; 900 * char cacc_saw_newack; 901 */ 902 struct { 903 /* An unsigned integer, which stores the next TSN to be 904 * used by the sender, at the moment of changeover. 905 */ 906 __u32 next_tsn_at_change; 907 908 /* A flag which indicates the occurrence of a changeover */ 909 char changeover_active; 910 911 /* A flag which indicates whether the change of primary is 912 * the first switch to this destination address during an 913 * active switch. 914 */ 915 char cycling_changeover; 916 917 /* A temporary flag, which is used during the processing of 918 * a SACK to estimate the causative TSN(s)'s group. 919 */ 920 char cacc_saw_newack; 921 } cacc; 922}; 923 924struct sctp_transport *sctp_transport_new(const union sctp_addr *, int); 925struct sctp_transport *sctp_transport_init(struct sctp_transport *, 926 const union sctp_addr *, int); 927void sctp_transport_set_owner(struct sctp_transport *, 928 struct sctp_association *); 929void sctp_transport_route(struct sctp_transport *, union sctp_addr *, 930 struct sctp_opt *); 931void sctp_transport_pmtu(struct sctp_transport *); 932void sctp_transport_free(struct sctp_transport *); 933void sctp_transport_destroy(struct sctp_transport *); 934void sctp_transport_reset_timers(struct sctp_transport *); 935void sctp_transport_hold(struct sctp_transport *); 936void sctp_transport_put(struct sctp_transport *); 937void sctp_transport_update_rto(struct sctp_transport *, __u32); 938void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32); 939void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t); 940unsigned long sctp_transport_timeout(struct sctp_transport *); 941 942 943/* This is the structure we use to queue packets as they come into 944 * SCTP. We write packets to it and read chunks from it. 945 */ 946struct sctp_inq { 947 /* This is actually a queue of sctp_chunk each 948 * containing a partially decoded packet. 949 */ 950 struct sk_buff_head in; 951 /* This is the packet which is currently off the in queue and is 952 * being worked on through the inbound chunk processing. 953 */ 954 struct sctp_chunk *in_progress; 955 956 /* This is the delayed task to finish delivering inbound 957 * messages. 958 */ 959 struct tq_struct immediate; 960 961 int malloced; /* Is this structure kfree()able? */ 962}; 963 964struct sctp_inq *sctp_inq_new(void); 965void sctp_inq_init(struct sctp_inq *); 966void sctp_inq_free(struct sctp_inq *); 967void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet); 968struct sctp_chunk *sctp_inq_pop(struct sctp_inq *); 969void sctp_inq_set_th_handler(struct sctp_inq *, void (*)(void *), void *); 970 971/* This is the structure we use to hold outbound chunks. You push 972 * chunks in and they automatically pop out the other end as bundled 973 * packets (it calls (*output_handler)()). 974 * 975 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1, 976 * and 8.2 of the v13 draft. 977 * 978 * It handles retransmissions. The connection to the timeout portion 979 * of the state machine is through sctp_..._timeout() and timeout_handler. 980 * 981 * If you feed it SACKs, it will eat them. 982 * 983 * If you give it big chunks, it will fragment them. 984 * 985 * It assigns TSN's to data chunks. This happens at the last possible 986 * instant before transmission. 987 * 988 * When free()'d, it empties itself out via output_handler(). 989 */ 990struct sctp_outq { 991 struct sctp_association *asoc; 992 993 /* Data pending that has never been transmitted. */ 994 struct sk_buff_head out; 995 996 unsigned out_qlen; /* Total length of queued data chunks. */ 997 998 /* Error of send failed, may used in SCTP_SEND_FAILED event. */ 999 unsigned error; 1000
1001 /* These are control chunks we want to send. */ 1002 struct sk_buff_head control; 1003 1004 /* These are chunks that have been sacked but are above the 1005 * CTSN, or cumulative tsn ack point. 1006 */ 1007 struct list_head sacked; 1008 1009 /* Put chunks on this list to schedule them for 1010 * retransmission. 1011 */ 1012 struct list_head retransmit; 1013 1014 /* Put chunks on this list to save them for FWD TSN processing as 1015 * they were abandoned. 1016 */ 1017 struct list_head abandoned; 1018 1019 /* How many unackd bytes do we have in-flight? */ 1020 __u32 outstanding_bytes; 1021 1022 /* Corked? */ 1023 char cork; 1024 1025 /* Is this structure empty? */ 1026 char empty; 1027 1028 /* Are we kfree()able? */ 1029 char malloced; 1030}; 1031 1032struct sctp_outq *sctp_outq_new(struct sctp_association *); 1033void sctp_outq_init(struct sctp_association *, struct sctp_outq *); 1034void sctp_outq_teardown(struct sctp_outq *); 1035void sctp_outq_free(struct sctp_outq*); 1036int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk); 1037int sctp_outq_flush(struct sctp_outq *, int); 1038int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *); 1039int sctp_outq_is_empty(const struct sctp_outq *); 1040void sctp_outq_restart(struct sctp_outq *); 1041 1042void sctp_retransmit(struct sctp_outq *, struct sctp_transport *, 1043 sctp_retransmit_reason_t); 1044void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); 1045int sctp_outq_uncork(struct sctp_outq *); 1046/* Uncork and flush an outqueue. */ 1047static inline void sctp_outq_cork(struct sctp_outq *q) 1048{ 1049 q->cork = 1; 1050} 1051 1052/* These bind address data fields common between endpoints and associations */ 1053struct sctp_bind_addr { 1054 1055 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1056 * 1057 * SCTP Port: The local SCTP port number the endpoint is 1058 * bound to. 1059 */ 1060 __u16 port; 1061 1062 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1063 * 1064 * Address List: The list of IP addresses that this instance 1065 * has bound. This information is passed to one's 1066 * peer(s) in INIT and INIT ACK chunks. 1067 */ 1068 struct list_head address_list; 1069 1070 int malloced; /* Are we kfree()able? */ 1071}; 1072 1073struct sctp_bind_addr *sctp_bind_addr_new(int gfp_mask); 1074void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port); 1075void sctp_bind_addr_free(struct sctp_bind_addr *); 1076int sctp_bind_addr_copy(struct sctp_bind_addr *dest, 1077 const struct sctp_bind_addr *src, 1078 sctp_scope_t scope, int gfp,int flags); 1079int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1080 int gfp); 1081int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *); 1082int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, 1083 struct sctp_opt *); 1084union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 1085 const union sctp_addr *addrs, 1086 int addrcnt, 1087 struct sctp_opt *opt); 1088union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 1089 int *addrs_len, int gfp); 1090int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, 1091 __u16 port, int gfp); 1092 1093sctp_scope_t sctp_scope(const union sctp_addr *); 1094int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope); 1095int sctp_is_any(const union sctp_addr *addr); 1096int sctp_addr_is_valid(const union sctp_addr *addr); 1097 1098 1099/* What type of endpoint? */ 1100typedef enum { 1101 SCTP_EP_TYPE_SOCKET, 1102 SCTP_EP_TYPE_ASSOCIATION, 1103} sctp_endpoint_type_t; 1104 1105/* 1106 * A common base class to bridge the implmentation view of a 1107 * socket (usually listening) endpoint versus an association's 1108 * local endpoint. 1109 * This common structure is useful for several purposes: 1110 * 1) Common interface for lookup routines. 1111 * a) Subfunctions work for either endpoint or association 1112 * b) Single interface to lookup allows hiding the lookup lock rather 1113 * than acquiring it externally. 1114 * 2) Common interface for the inbound chunk handling/state machine. 1115 * 3) Common object handling routines for reference counting, etc. 1116 * 4) Disentangle association lookup from endpoint lookup, where we 1117 * do not have to find our endpoint to find our association. 1118 * 1119 */ 1120 1121struct sctp_ep_common { 1122 /* Fields to help us manage our entries in the hash tables. */ 1123 struct sctp_ep_common *next; 1124 struct sctp_ep_common **pprev; 1125 int hashent; 1126 1127 /* Runtime type information. What kind of endpoint is this? */ 1128 sctp_endpoint_type_t type; 1129 1130 /* Some fields to help us manage this object. 1131 * refcnt - Reference count access to this object. 1132 * dead - Do not attempt to use this object. 1133 * malloced - Do we need to kfree this object? 1134 */ 1135 atomic_t refcnt; 1136 char dead; 1137 char malloced; 1138 1139 /* What socket does this endpoint belong to? */ 1140 struct sock *sk; 1141 1142 /* This is where we receive inbound chunks. */ 1143 struct sctp_inq inqueue; 1144 1145 /* This substructure includes the defining parameters of the 1146 * endpoint: 1147 * bind_addr.port is our shared port number. 1148 * bind_addr.address_list is our set of local IP addresses. 1149 */ 1150 struct sctp_bind_addr bind_addr; 1151 1152 /* Protection during address list comparisons. */ 1153 rwlock_t addr_lock; 1154}; 1155 1156 1157/* RFC Section 1.4 Key Terms 1158 * 1159 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a 1160 * multi-homed host, an SCTP endpoint is represented to its peers as a 1161 * combination of a set of eligible destination transport addresses to 1162 * which SCTP packets can be sent and a set of eligible source 1163 * transport addresses from which SCTP packets can be received. 1164 * All transport addresses used by an SCTP endpoint must use the 1165 * same port number, but can use multiple IP addresses. A transport 1166 * address used by an SCTP endpoint must not be used by another 1167 * SCTP endpoint. In other words, a transport address is unique 1168 * to an SCTP endpoint. 1169 * 1170 * From an implementation perspective, each socket has one of these. 1171 * A TCP-style socket will have exactly one association on one of 1172 * these. An UDP-style socket will have multiple associations hanging 1173 * off one of these. 1174 */ 1175 1176struct sctp_endpoint { 1177 /* Common substructure for endpoint and association. */ 1178 struct sctp_ep_common base; 1179 1180 /* Associations: A list of current associations and mappings 1181 * to the data consumers for each association. This 1182 * may be in the form of a hash table or other 1183 * implementation dependent structure. The data 1184 * consumers may be process identification 1185 * information such as file descriptors, named pipe 1186 * pointer, or table pointers dependent on how SCTP 1187 * is implemented. 1188 */ 1189 /* This is really a list of struct sctp_association entries. */ 1190 struct list_head asocs; 1191 1192 /* Secret Key: A secret key used by this endpoint to compute 1193 * the MAC. This SHOULD be a cryptographic quality 1194 * random number with a sufficient length. 1195 * Discussion in [RFC1750] can be helpful in 1196 * selection of the key. 1197 */ 1198 __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE]; 1199 int current_key; 1200 int last_key; 1201 int key_changed_at; 1202 1203 /* Default timeouts. */ 1204 int timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1205 1206 /* Various thresholds. */ 1207 1208 /* Name for debugging output... */ 1209 char *debug_name; 1210}; 1211 1212/* Recover the outter endpoint structure. */ 1213static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) 1214{ 1215 struct sctp_endpoint *ep; 1216 1217 ep = container_of(base, struct sctp_endpoint, base); 1218 return ep; 1219} 1220 1221/* These are function signatures for manipulating endpoints. */ 1222struct sctp_endpoint *sctp_endpoint_new(struct sock *, int); 1223struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *, 1224 struct sock *, int gfp); 1225void sctp_endpoint_free(struct sctp_endpoint *); 1226void sctp_endpoint_put(struct sctp_endpoint *); 1227void sctp_endpoint_hold(struct sctp_endpoint *); 1228void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); 1229struct sctp_association *sctp_endpoint_lookup_assoc( 1230 const struct sctp_endpoint *ep, 1231 const union sctp_addr *paddr, 1232 struct sctp_transport **); 1233int sctp_endpoint_is_peeled_off(struct sctp_endpoint *, 1234 const union sctp_addr *); 1235struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *, 1236 const union sctp_addr *); 1237int sctp_has_association(const union sctp_addr *laddr, 1238 const union sctp_addr *paddr); 1239 1240int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t, 1241 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk, 1242 struct sctp_chunk **err_chunk); 1243int sctp_process_init(struct sctp_association *, sctp_cid_t cid, 1244 const union sctp_addr *peer, 1245 sctp_init_chunk_t *init, int gfp); 1246int sctp_process_param(struct sctp_association *, union sctp_params param, 1247 const union sctp_addr *from, int gfp); 1248__u32 sctp_generate_tag(const struct sctp_endpoint *); 1249__u32 sctp_generate_tsn(const struct sctp_endpoint *); 1250 1251 1252/* RFC2960 1253 * 1254 * 12. Recommended Transmission Control Block (TCB) Parameters 1255 * 1256 * This section details a recommended set of parameters that should 1257 * be contained within the TCB for an implementation. This section is 1258 * for illustrative purposes and should not be deemed as requirements 1259 * on an implementation or as an exhaustive list of all parameters 1260 * inside an SCTP TCB. Each implementation may need its own additional 1261 * parameters for optimization. 1262 */ 1263 1264 1265/* Here we have information about each individual association. */ 1266struct sctp_association { 1267 1268 /* A base structure common to endpoint and association. 1269 * In this context, it represents the associations's view 1270 * of the local endpoint of the association. 1271 */ 1272 struct sctp_ep_common base; 1273 1274 /* Associations on the same socket. */ 1275 struct list_head asocs; 1276 1277 /* This is a signature that lets us know that this is a 1278 * struct sctp_association data structure. Used for mapping an 1279 * association id to an association. 1280 */ 1281 __u32 eyecatcher; 1282 1283 /* This is our parent endpoint. */ 1284 struct sctp_endpoint *ep; 1285 1286 /* These are those association elements needed in the cookie. */ 1287 struct sctp_cookie c; 1288 1289 /* This is all information about our peer. */ 1290 struct { 1291 /* rwnd 1292 * 1293 * Peer Rwnd : Current calculated value of the peer's rwnd. 1294 */ 1295 __u32 rwnd; 1296 1297 /* transport_addr_list 1298 * 1299 * Peer : A list of SCTP transport addresses that the 1300 * Transport : peer is bound to. This information is derived 1301 * Address : from the INIT or INIT ACK and is used to 1302 * List : associate an inbound packet with a given 1303 * : association. Normally this information is 1304 * : hashed or keyed for quick lookup and access 1305 * : of the TCB. 1306 * 1307 * It is a list of SCTP_transport's. 1308 */ 1309 struct list_head transport_addr_list; 1310 1311 /* port 1312 * The transport layer port number. 1313 */ 1314 __u16 port; 1315 1316 /* primary_path 1317 * 1318 * Primary : This is the current primary destination 1319 * Path : transport address of the peer endpoint. It 1320 * : may also specify a source transport address 1321 * : on this endpoint. 1322 * 1323 * All of these paths live on transport_addr_list. 1324 * 1325 * At the bakeoffs, we discovered that the intent of 1326 * primaryPath is that it only changes when the ULP 1327 * asks to have it changed. We add the activePath to 1328 * designate the connection we are currently using to 1329 * transmit new data and most control chunks. 1330 */ 1331 struct sctp_transport *primary_path; 1332 1333 /* Cache the primary path address here, when we 1334 * need a an address for msg_name. 1335 */ 1336 union sctp_addr primary_addr; 1337 1338 /* active_path 1339 * The path that we are currently using to 1340 * transmit new data and most control chunks. 1341 */ 1342 struct sctp_transport *active_path; 1343 1344 /* retran_path 1345 * 1346 * RFC2960 6.4 Multi-homed SCTP Endpoints 1347 * ... 1348 * Furthermore, when its peer is multi-homed, an 1349 * endpoint SHOULD try to retransmit a chunk to an 1350 * active destination transport address that is 1351 * different from the last destination address to 1352 * which the DATA chunk was sent. 1353 */ 1354 struct sctp_transport *retran_path; 1355 1356 /* Pointer to last transport I have sent on. */ 1357 struct sctp_transport *last_sent_to; 1358 1359 /* This is the last transport I have received DATA on. */ 1360 struct sctp_transport *last_data_from; 1361 1362 /* 1363 * Mapping An array of bits or bytes indicating which out of 1364 * Array order TSN's have been received (relative to the 1365 * Last Rcvd TSN). If no gaps exist, i.e. no out of 1366 * order packets have been received, this array 1367 * will be set to all zero. This structure may be 1368 * in the form of a circular buffer or bit array. 1369 * 1370 * Last Rcvd : This is the last TSN received in 1371 * TSN : sequence. This value is set initially by 1372 * : taking the peer's Initial TSN, received in 1373 * : the INIT or INIT ACK chunk, and subtracting 1374 * : one from it. 1375 * 1376 * Throughout most of the specification this is called the 1377 * "Cumulative TSN ACK Point". In this case, we 1378 * ignore the advice in 12.2 in favour of the term 1379 * used in the bulk of the text. This value is hidden 1380 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). 1381 */ 1382 struct sctp_tsnmap tsn_map; 1383 __u8 _map[sctp_tsnmap_storage_size(SCTP_TSN_MAP_SIZE)]; 1384 1385 /* Ack State : This flag indicates if the next received 1386 * : packet is to be responded to with a 1387 * : SACK. This is initializedto 0. When a packet 1388 * : is received it is incremented. If this value 1389 * : reaches 2 or more, a SACK is sent and the 1390 * : value is reset to 0. Note: This is used only 1391 * : when no DATA chunks are received out of 1392 * : order. When DATA chunks are out of order, 1393 * : SACK's are not delayed (see Section 6). 1394 */ 1395 __u8 sack_needed; /* Do we need to sack the peer? */ 1396 1397 /* These are capabilities which our peer advertised. */ 1398 __u8 ecn_capable; /* Can peer do ECN? */ 1399 __u8 ipv4_address; /* Peer understands IPv4 addresses? */ 1400 __u8 ipv6_address; /* Peer understands IPv6 addresses? */ 1401 __u8 hostname_address;/* Peer understands DNS addresses? */ 1402 __u8 asconf_capable; /* Does peer support ADDIP? */ 1403 __u8 prsctp_capable; /* Can peer do PR-SCTP? */ 1404 1405 __u32 adaption_ind; /* Adaption Code point. */ 1406 1407 /* This mask is used to disable sending the ASCONF chunk 1408 * with specified parameter to peer. 1409 */ 1410 __u16 addip_disabled_mask; 1411 1412 struct sctp_inithdr i; 1413 int cookie_len; 1414 void *cookie; 1415 1416 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1417 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the 1418 * Initial TSN Value minus 1 1419 */ 1420 __u32 addip_serial; 1421 } peer; 1422 1423 /* State : A state variable indicating what state the 1424 * : association is in, i.e. COOKIE-WAIT, 1425 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, 1426 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. 1427 * 1428 * Note: No "CLOSED" state is illustrated since if a 1429 * association is "CLOSED" its TCB SHOULD be removed. 1430 * 1431 * In this implementation we DO have a CLOSED 1432 * state which is used during initiation and shutdown. 1433 * 1434 * State takes values from SCTP_STATE_*. 1435 */ 1436 sctp_state_t state; 1437 1438 /* The cookie life I award for any cookie. */ 1439 struct timeval cookie_life; 1440 1441 /* Overall : The overall association error count. 1442 * Error Count : [Clear this any time I get something.] 1443 */ 1444 int overall_error_count; 1445 1446 /* These are the association's initial, max, and min RTO values. 1447 * These values will be initialized by system defaults, but can 1448 * be modified via the SCTP_RTOINFO socket option. 1449 */ 1450 __u32 rto_initial; 1451 __u32 rto_max; 1452 __u32 rto_min; 1453 1454 /* Maximum number of new data packets that can be sent in a burst. */ 1455 int max_burst; 1456 1457 /* This is the max_retrans value for the association. This value will 1458 * be initialized initialized from system defaults, but can be 1459 * modified by the SCTP_ASSOCINFO socket option. 1460 */ 1461 int max_retrans; 1462 1463 /* Maximum number of times the endpoint will retransmit INIT */ 1464 __u16 max_init_attempts; 1465 1466 /* How many times have we resent an INIT? */ 1467 __u16 init_retries; 1468 1469 /* The largest timeout or RTO value to use in attempting an INIT */ 1470 __u16 max_init_timeo; 1471 1472 int timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1473 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; 1474 1475 /* Transport to which SHUTDOWN chunk was last sent. */ 1476 struct sctp_transport *shutdown_last_sent_to; 1477 1478 /* Next TSN : The next TSN number to be assigned to a new 1479 * : DATA chunk. This is sent in the INIT or INIT 1480 * : ACK chunk to the peer and incremented each 1481 * : time a DATA chunk is assigned a TSN 1482 * : (normally just prior to transmit or during 1483 * : fragmentation). 1484 */ 1485 __u32 next_tsn; 1486 1487 /* 1488 * Last Rcvd : This is the last TSN received in sequence. This value 1489 * TSN : is set initially by taking the peer's Initial TSN, 1490 * : received in the INIT or INIT ACK chunk, and 1491 * : subtracting one from it. 1492 * 1493 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. 1494 */ 1495 1496 __u32 ctsn_ack_point; 1497 1498 /* PR-SCTP Advanced.Peer.Ack.Point */ 1499 __u32 adv_peer_ack_point; 1500 1501 /* Highest TSN that is acknowledged by incoming SACKs. */ 1502 __u32 highest_sacked; 1503 1504 /* The number of unacknowledged data chunks. Reported through 1505 * the SCTP_STATUS sockopt. 1506 */ 1507 __u16 unack_data; 1508 1509 /* This is the association's receive buffer space. This value is used 1510 * to set a_rwnd field in an INIT or a SACK chunk. 1511 */ 1512 __u32 rwnd; 1513 1514 /* This is the last advertised value of rwnd over a SACK chunk. */ 1515 __u32 a_rwnd; 1516 1517 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed 1518 * to slop over a maximum of the association's frag_point. 1519 */ 1520 __u32 rwnd_over; 1521 1522 /* This is the sndbuf size in use for the association. 1523 * This corresponds to the sndbuf size for the association, 1524 * as specified in the sk->sndbuf. 1525 */ 1526 int sndbuf_used; 1527 1528 /* This is the wait queue head for send requests waiting on 1529 * the association sndbuf space. 1530 */ 1531 wait_queue_head_t wait; 1532 1533 /* Association : The smallest PMTU discovered for all of the 1534 * PMTU : peer's transport addresses. 1535 */ 1536 __u32 pmtu; 1537 1538 /* The message size at which SCTP fragmentation will occur. */ 1539 __u32 frag_point; 1540 1541 /* Currently only one counter is used to count INIT errors. */ 1542 int counters[SCTP_NUMBER_COUNTERS]; 1543 1544 /* Default send parameters. */ 1545 __u16 default_stream; 1546 __u16 default_flags; 1547 __u32 default_ppid; 1548 __u32 default_context; 1549 __u32 default_timetolive; 1550 1551 /* This tracks outbound ssn for a given stream. */ 1552 struct sctp_ssnmap *ssnmap; 1553 1554 /* All outbound chunks go through this structure. */ 1555 struct sctp_outq outqueue; 1556 1557 /* A smart pipe that will handle reordering and fragmentation, 1558 * as well as handle passing events up to the ULP. 1559 */ 1560 struct sctp_ulpq ulpq; 1561 1562 /* Last TSN that caused an ECNE Chunk to be sent. */ 1563 __u32 last_ecne_tsn; 1564 1565 /* Last TSN that caused a CWR Chunk to be sent. */ 1566 __u32 last_cwr_tsn; 1567 1568 /* How many duplicated TSNs have we seen? */ 1569 int numduptsns; 1570 1571 /* Number of seconds of idle time before an association is closed. */ 1572 __u32 autoclose; 1573 1574 /* These are to support 1575 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses 1576 * and Enforcement of Flow and Message Limits" 1577 * <draft-ietf-tsvwg-addip-sctp-02.txt> 1578 * or "ADDIP" for short. 1579 */ 1580 1581 1582 1583 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1584 * 1585 * R1) One and only one ASCONF Chunk MAY be in transit and 1586 * unacknowledged at any one time. If a sender, after sending 1587 * an ASCONF chunk, decides it needs to transfer another 1588 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1589 * returns from the previous ASCONF Chunk before sending a 1590 * subsequent ASCONF. Note this restriction binds each side, 1591 * so at any time two ASCONF may be in-transit on any given 1592 * association (one sent from each endpoint). 1593 * 1594 * [This is our one-and-only-one ASCONF in flight. If we do 1595 * not have an ASCONF in flight, this is NULL.] 1596 */ 1597 struct sctp_chunk *addip_last_asconf; 1598 1599 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1600 * 1601 * IMPLEMENTATION NOTE: As an optimization a receiver may wish 1602 * to save the last ASCONF-ACK for some predetermined period 1603 * of time and instead of re-processing the ASCONF (with the 1604 * same serial number) it may just re-transmit the 1605 * ASCONF-ACK. It may wish to use the arrival of a new serial 1606 * number to discard the previously saved ASCONF-ACK or any 1607 * other means it may choose to expire the saved ASCONF-ACK. 1608 * 1609 * [This is our saved ASCONF-ACK. We invalidate it when a new 1610 * ASCONF serial number arrives.] 1611 */ 1612 struct sctp_chunk *addip_last_asconf_ack; 1613 1614 /* These ASCONF chunks are waiting to be sent. 1615 * 1616 * These chunaks can't be pushed to outqueue until receiving 1617 * ASCONF_ACK for the previous ASCONF indicated by 1618 * addip_last_asconf, so as to guarantee that only one ASCONF 1619 * is in flight at any time. 1620 * 1621 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1622 * 1623 * In defining the ASCONF Chunk transfer procedures, it is 1624 * essential that these transfers MUST NOT cause congestion 1625 * within the network. To achieve this, we place these 1626 * restrictions on the transfer of ASCONF Chunks: 1627 * 1628 * R1) One and only one ASCONF Chunk MAY be in transit and 1629 * unacknowledged at any one time. If a sender, after sending 1630 * an ASCONF chunk, decides it needs to transfer another 1631 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1632 * returns from the previous ASCONF Chunk before sending a 1633 * subsequent ASCONF. Note this restriction binds each side, 1634 * so at any time two ASCONF may be in-transit on any given 1635 * association (one sent from each endpoint). 1636 * 1637 * 1638 * [I really think this is EXACTLY the sort of intelligence 1639 * which already resides in sctp_outq. Please move this 1640 * queue and its supporting logic down there. --piggy] 1641 */ 1642 struct sk_buff_head addip_chunks; 1643 1644 /* ADDIP Section 4.1 ASCONF Chunk Procedures 1645 * 1646 * A2) A serial number should be assigned to the Chunk. The 1647 * serial number SHOULD be a monotonically increasing 1648 * number. The serial number SHOULD be initialized at 1649 * the start of the association to the same value as the 1650 * Initial TSN and every time a new ASCONF chunk is created 1651 * it is incremented by one after assigning the serial number 1652 * to the newly created chunk. 1653 * 1654 * ADDIP 1655 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) 1656 * 1657 * Serial Number : 32 bits (unsigned integer) 1658 * 1659 * This value represents a Serial Number for the ASCONF 1660 * Chunk. The valid range of Serial Number is from 0 to 1661 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 1662 * after reaching 4294967295. 1663 */ 1664 __u32 addip_serial; 1665 1666 /* Need to send an ECNE Chunk? */ 1667 char need_ecne; 1668 1669 /* Is it a temporary association? */ 1670 char temp; 1671}; 1672 1673 1674/* An eyecatcher for determining if we are really looking at an 1675 * association data structure. 1676 */ 1677enum { 1678 SCTP_ASSOC_EYECATCHER = 0xa550c123, 1679}; 1680 1681/* Recover the outter association structure. */ 1682static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) 1683{ 1684 struct sctp_association *asoc; 1685 1686 asoc = container_of(base, struct sctp_association, base); 1687 return asoc; 1688} 1689 1690/* These are function signatures for manipulating associations. */ 1691 1692 1693struct sctp_association * 1694sctp_association_new(const struct sctp_endpoint *, const struct sock *, 1695 sctp_scope_t scope, int gfp); 1696struct sctp_association * 1697sctp_association_init(struct sctp_association *, const struct sctp_endpoint *, 1698 const struct sock *, sctp_scope_t scope, 1699 int gfp); 1700void sctp_association_free(struct sctp_association *); 1701void sctp_association_put(struct sctp_association *); 1702void sctp_association_hold(struct sctp_association *); 1703 1704struct sctp_transport *sctp_assoc_choose_shutdown_transport( 1705 struct sctp_association *); 1706void sctp_assoc_update_retran_path(struct sctp_association *); 1707struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, 1708 const union sctp_addr *); 1709int sctp_assoc_lookup_laddr(struct sctp_association *asoc, 1710 const union sctp_addr *laddr); 1711struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, 1712 const union sctp_addr *address, 1713 const int gfp); 1714void sctp_assoc_del_peer(struct sctp_association *asoc, 1715 const union sctp_addr *addr); 1716void sctp_assoc_control_transport(struct sctp_association *, 1717 struct sctp_transport *, 1718 sctp_transport_cmd_t, sctp_sn_error_t); 1719struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); 1720struct sctp_transport *sctp_assoc_is_match(struct sctp_association *, 1721 const union sctp_addr *, 1722 const union sctp_addr *); 1723void sctp_assoc_migrate(struct sctp_association *, struct sock *); 1724void sctp_assoc_update(struct sctp_association *old, 1725 struct sctp_association *new); 1726 1727__u32 sctp_association_get_next_tsn(struct sctp_association *); 1728__u32 sctp_association_get_tsn_block(struct sctp_association *, int); 1729 1730void sctp_assoc_sync_pmtu(struct sctp_association *); 1731void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned); 1732void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned); 1733void sctp_assoc_set_primary(struct sctp_association *, 1734 struct sctp_transport *); 1735int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *, int); 1736int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, 1737 struct sctp_cookie*, int gfp); 1738 1739int sctp_cmp_addr_exact(const union sctp_addr *ss1, 1740 const union sctp_addr *ss2); 1741struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); 1742struct sctp_chunk *sctp_get_no_prepend(struct sctp_association *asoc); 1743 1744/* A convenience structure to parse out SCTP specific CMSGs. */ 1745typedef struct sctp_cmsgs { 1746 struct sctp_initmsg *init; 1747 struct sctp_sndrcvinfo *info; 1748} sctp_cmsgs_t; 1749 1750/* Structure for tracking memory objects */ 1751typedef struct { 1752 char *label; 1753 atomic_t *counter; 1754} sctp_dbg_objcnt_entry_t; 1755 1756#endif /* __sctp_structs_h__ */ 1757