1/* SCTP kernel reference Implementation 2 * (C) Copyright IBM Corp. 2001, 2004 3 * Copyright (c) 1999-2000 Cisco, Inc. 4 * Copyright (c) 1999-2001 Motorola, Inc. 5 * Copyright (c) 2001 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 <linux/ipv6.h> 62#include <asm/param.h> /* We get MAXHOSTNAMELEN. */ 63#include <asm/atomic.h> /* This gets us atomic counters. */ 64#include <linux/skbuff.h> /* We need sk_buff_head. */ 65#include <linux/workqueue.h> /* We need tq_struct. */ 66#include <linux/sctp.h> /* We need sctp* header structs. */ 67 68/* A convenience structure for handling sockaddr structures. 69 * We should wean ourselves off this. 70 */ 71union sctp_addr { 72 struct sockaddr_in v4; 73 struct sockaddr_in6 v6; 74 struct sockaddr sa; 75}; 76 77/* Forward declarations for data structures. */ 78struct sctp_globals; 79struct sctp_endpoint; 80struct sctp_association; 81struct sctp_transport; 82struct sctp_packet; 83struct sctp_chunk; 84struct sctp_inq; 85struct sctp_outq; 86struct sctp_bind_addr; 87struct sctp_ulpq; 88struct sctp_ep_common; 89struct sctp_ssnmap; 90struct crypto_hash; 91 92 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 hlist_head owner; 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 unsigned int rto_initial; 132 unsigned int rto_min; 133 unsigned int 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 /* Whether Cookie Preservative is enabled(1) or not(0) */ 145 int cookie_preserve_enable; 146 147 /* Valid.Cookie.Life - 60 seconds */ 148 unsigned int valid_cookie_life; 149 150 /* Delayed SACK timeout 200ms default*/ 151 unsigned int sack_timeout; 152 153 /* HB.interval - 30 seconds */ 154 unsigned int hb_interval; 155 156 /* Association.Max.Retrans - 10 attempts 157 * Path.Max.Retrans - 5 attempts (per destination address) 158 * Max.Init.Retransmits - 8 attempts 159 */ 160 int max_retrans_association; 161 int max_retrans_path; 162 int max_retrans_init; 163 164 /* 165 * Policy for preforming sctp/socket accounting 166 * 0 - do socket level accounting, all assocs share sk_sndbuf 167 * 1 - do sctp accounting, each asoc may use sk_sndbuf bytes 168 */ 169 int sndbuf_policy; 170 171 /* 172 * Policy for preforming sctp/socket accounting 173 * 0 - do socket level accounting, all assocs share sk_rcvbuf 174 * 1 - do sctp accounting, each asoc may use sk_rcvbuf bytes 175 */ 176 int rcvbuf_policy; 177 178 /* The following variables are implementation specific. */ 179 180 /* Default initialization values to be applied to new associations. */ 181 __u16 max_instreams; 182 __u16 max_outstreams; 183 184 /* This is a list of groups of functions for each address 185 * family that we support. 186 */ 187 struct list_head address_families; 188 189 /* This is the hash of all endpoints. */ 190 int ep_hashsize; 191 struct sctp_hashbucket *ep_hashtable; 192 193 /* This is the hash of all associations. */ 194 int assoc_hashsize; 195 struct sctp_hashbucket *assoc_hashtable; 196 197 /* This is the sctp port control hash. */ 198 int port_hashsize; 199 int port_rover; 200 spinlock_t port_alloc_lock; /* Protects port_rover. */ 201 struct sctp_bind_hashbucket *port_hashtable; 202 203 /* This is the global local address list. 204 * We actively maintain this complete list of addresses on 205 * the system by catching address add/delete events. 206 * 207 * It is a list of sctp_sockaddr_entry. 208 */ 209 struct list_head local_addr_list; 210 211 /* Flag to indicate if addip is enabled. */ 212 int addip_enable; 213 214 /* Flag to indicate if PR-SCTP is enabled. */ 215 int prsctp_enable; 216} sctp_globals; 217 218#define sctp_rto_initial (sctp_globals.rto_initial) 219#define sctp_rto_min (sctp_globals.rto_min) 220#define sctp_rto_max (sctp_globals.rto_max) 221#define sctp_rto_alpha (sctp_globals.rto_alpha) 222#define sctp_rto_beta (sctp_globals.rto_beta) 223#define sctp_max_burst (sctp_globals.max_burst) 224#define sctp_valid_cookie_life (sctp_globals.valid_cookie_life) 225#define sctp_cookie_preserve_enable (sctp_globals.cookie_preserve_enable) 226#define sctp_max_retrans_association (sctp_globals.max_retrans_association) 227#define sctp_sndbuf_policy (sctp_globals.sndbuf_policy) 228#define sctp_rcvbuf_policy (sctp_globals.rcvbuf_policy) 229#define sctp_max_retrans_path (sctp_globals.max_retrans_path) 230#define sctp_max_retrans_init (sctp_globals.max_retrans_init) 231#define sctp_sack_timeout (sctp_globals.sack_timeout) 232#define sctp_hb_interval (sctp_globals.hb_interval) 233#define sctp_max_instreams (sctp_globals.max_instreams) 234#define sctp_max_outstreams (sctp_globals.max_outstreams) 235#define sctp_address_families (sctp_globals.address_families) 236#define sctp_ep_hashsize (sctp_globals.ep_hashsize) 237#define sctp_ep_hashtable (sctp_globals.ep_hashtable) 238#define sctp_assoc_hashsize (sctp_globals.assoc_hashsize) 239#define sctp_assoc_hashtable (sctp_globals.assoc_hashtable) 240#define sctp_port_hashsize (sctp_globals.port_hashsize) 241#define sctp_port_rover (sctp_globals.port_rover) 242#define sctp_port_alloc_lock (sctp_globals.port_alloc_lock) 243#define sctp_port_hashtable (sctp_globals.port_hashtable) 244#define sctp_local_addr_list (sctp_globals.local_addr_list) 245#define sctp_addip_enable (sctp_globals.addip_enable) 246#define sctp_prsctp_enable (sctp_globals.prsctp_enable) 247 248/* SCTP Socket type: UDP or TCP style. */ 249typedef enum { 250 SCTP_SOCKET_UDP = 0, 251 SCTP_SOCKET_UDP_HIGH_BANDWIDTH, 252 SCTP_SOCKET_TCP 253} sctp_socket_type_t; 254 255/* Per socket SCTP information. */ 256struct sctp_sock { 257 /* inet_sock has to be the first member of sctp_sock */ 258 struct inet_sock inet; 259 /* What kind of a socket is this? */ 260 sctp_socket_type_t type; 261 262 /* PF_ family specific functions. */ 263 struct sctp_pf *pf; 264 265 /* Access to HMAC transform. */ 266 struct crypto_hash *hmac; 267 268 /* What is our base endpointer? */ 269 struct sctp_endpoint *ep; 270 271 struct sctp_bind_bucket *bind_hash; 272 /* Various Socket Options. */ 273 __u16 default_stream; 274 __u32 default_ppid; 275 __u16 default_flags; 276 __u32 default_context; 277 __u32 default_timetolive; 278 __u32 default_rcv_context; 279 int max_burst; 280 281 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 282 * the destination address every heartbeat interval. This value 283 * will be inherited by all new associations. 284 */ 285 __u32 hbinterval; 286 287 /* This is the max_retrans value for new associations. */ 288 __u16 pathmaxrxt; 289 290 /* The initial Path MTU to use for new associations. */ 291 __u32 pathmtu; 292 293 /* The default SACK delay timeout for new associations. */ 294 __u32 sackdelay; 295 296 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 297 __u32 param_flags; 298 299 struct sctp_initmsg initmsg; 300 struct sctp_rtoinfo rtoinfo; 301 struct sctp_paddrparams paddrparam; 302 struct sctp_event_subscribe subscribe; 303 struct sctp_assocparams assocparams; 304 int user_frag; 305 __u32 autoclose; 306 __u8 nodelay; 307 __u8 disable_fragments; 308 __u8 v4mapped; 309 __u8 frag_interleave; 310 __u32 adaptation_ind; 311 __u32 pd_point; 312 313 atomic_t pd_mode; 314 /* Receive to here while partial delivery is in effect. */ 315 struct sk_buff_head pd_lobby; 316}; 317 318static inline struct sctp_sock *sctp_sk(const struct sock *sk) 319{ 320 return (struct sctp_sock *)sk; 321} 322 323static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp) 324{ 325 return (struct sock *)sp; 326} 327 328#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 329struct sctp6_sock { 330 struct sctp_sock sctp; 331 struct ipv6_pinfo inet6; 332}; 333#endif /* CONFIG_IPV6 */ 334 335 336/* This is our APPLICATION-SPECIFIC state cookie. 337 * THIS IS NOT DICTATED BY THE SPECIFICATION. 338 */ 339/* These are the parts of an association which we send in the cookie. 340 * Most of these are straight out of: 341 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB) 342 * 343 */ 344 345struct sctp_cookie { 346 347 /* My : Tag expected in every inbound packet and sent 348 * Verification: in the INIT or INIT ACK chunk. 349 * Tag : 350 */ 351 __u32 my_vtag; 352 353 /* Peer's : Tag expected in every outbound packet except 354 * Verification: in the INIT chunk. 355 * Tag : 356 */ 357 __u32 peer_vtag; 358 359 /* The rest of these are not from the spec, but really need to 360 * be in the cookie. 361 */ 362 363 /* My Tie Tag : Assist in discovering a restarting association. */ 364 __u32 my_ttag; 365 366 /* Peer's Tie Tag: Assist in discovering a restarting association. */ 367 __u32 peer_ttag; 368 369 /* When does this cookie expire? */ 370 struct timeval expiration; 371 372 /* Number of inbound/outbound streams which are set 373 * and negotiated during the INIT process. 374 */ 375 __u16 sinit_num_ostreams; 376 __u16 sinit_max_instreams; 377 378 /* This is the first sequence number I used. */ 379 __u32 initial_tsn; 380 381 /* This holds the originating address of the INIT packet. */ 382 union sctp_addr peer_addr; 383 384 /* IG Section 2.35.3 385 * Include the source port of the INIT-ACK 386 */ 387 __u16 my_port; 388 389 __u8 prsctp_capable; 390 391 /* Padding for future use */ 392 __u8 padding; 393 394 __u32 adaptation_ind; 395 396 397 /* This is a shim for my peer's INIT packet, followed by 398 * a copy of the raw address list of the association. 399 * The length of the raw address list is saved in the 400 * raw_addr_list_len field, which will be used at the time when 401 * the association TCB is re-constructed from the cookie. 402 */ 403 __u32 raw_addr_list_len; 404 struct sctp_init_chunk peer_init[0]; 405}; 406 407 408/* The format of our cookie that we send to our peer. */ 409struct sctp_signed_cookie { 410 __u8 signature[SCTP_SECRET_SIZE]; 411 __u32 __pad; /* force sctp_cookie alignment to 64 bits */ 412 struct sctp_cookie c; 413} __attribute__((packed)); 414 415/* This is another convenience type to allocate memory for address 416 * params for the maximum size and pass such structures around 417 * internally. 418 */ 419union sctp_addr_param { 420 struct sctp_ipv4addr_param v4; 421 struct sctp_ipv6addr_param v6; 422}; 423 424/* A convenience type to allow walking through the various 425 * parameters and avoid casting all over the place. 426 */ 427union sctp_params { 428 void *v; 429 struct sctp_paramhdr *p; 430 struct sctp_cookie_preserve_param *life; 431 struct sctp_hostname_param *dns; 432 struct sctp_cookie_param *cookie; 433 struct sctp_supported_addrs_param *sat; 434 struct sctp_ipv4addr_param *v4; 435 struct sctp_ipv6addr_param *v6; 436 union sctp_addr_param *addr; 437 struct sctp_adaptation_ind_param *aind; 438}; 439 440/* RFC 2960. Section 3.3.5 Heartbeat. 441 * Heartbeat Information: variable length 442 * The Sender-specific Heartbeat Info field should normally include 443 * information about the sender's current time when this HEARTBEAT 444 * chunk is sent and the destination transport address to which this 445 * HEARTBEAT is sent (see Section 8.3). 446 */ 447typedef struct sctp_sender_hb_info { 448 struct sctp_paramhdr param_hdr; 449 union sctp_addr daddr; 450 unsigned long sent_at; 451 __u64 hb_nonce; 452} __attribute__((packed)) sctp_sender_hb_info_t; 453 454/* 455 * RFC 2960 1.3.2 Sequenced Delivery within Streams 456 * 457 * The term "stream" is used in SCTP to refer to a sequence of user 458 * messages that are to be delivered to the upper-layer protocol in 459 * order with respect to other messages within the same stream. This is 460 * in contrast to its usage in TCP, where it refers to a sequence of 461 * bytes (in this document a byte is assumed to be eight bits). 462 * ... 463 * 464 * This is the structure we use to track both our outbound and inbound 465 * SSN, or Stream Sequence Numbers. 466 */ 467 468struct sctp_stream { 469 __u16 *ssn; 470 unsigned int len; 471}; 472 473struct sctp_ssnmap { 474 struct sctp_stream in; 475 struct sctp_stream out; 476 int malloced; 477}; 478 479struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, 480 gfp_t gfp); 481void sctp_ssnmap_free(struct sctp_ssnmap *map); 482void sctp_ssnmap_clear(struct sctp_ssnmap *map); 483 484/* What is the current SSN number for this stream? */ 485static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id) 486{ 487 return stream->ssn[id]; 488} 489 490/* Return the next SSN number for this stream. */ 491static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id) 492{ 493 return stream->ssn[id]++; 494} 495 496/* Skip over this ssn and all below. */ 497static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, 498 __u16 ssn) 499{ 500 stream->ssn[id] = ssn+1; 501} 502 503/* 504 * Pointers to address related SCTP functions. 505 * (i.e. things that depend on the address family.) 506 */ 507struct sctp_af { 508 int (*sctp_xmit) (struct sk_buff *skb, 509 struct sctp_transport *, 510 int ipfragok); 511 int (*setsockopt) (struct sock *sk, 512 int level, 513 int optname, 514 char __user *optval, 515 int optlen); 516 int (*getsockopt) (struct sock *sk, 517 int level, 518 int optname, 519 char __user *optval, 520 int __user *optlen); 521 int (*compat_setsockopt) (struct sock *sk, 522 int level, 523 int optname, 524 char __user *optval, 525 int optlen); 526 int (*compat_getsockopt) (struct sock *sk, 527 int level, 528 int optname, 529 char __user *optval, 530 int __user *optlen); 531 struct dst_entry *(*get_dst) (struct sctp_association *asoc, 532 union sctp_addr *daddr, 533 union sctp_addr *saddr); 534 void (*get_saddr) (struct sctp_association *asoc, 535 struct dst_entry *dst, 536 union sctp_addr *daddr, 537 union sctp_addr *saddr); 538 void (*copy_addrlist) (struct list_head *, 539 struct net_device *); 540 void (*dst_saddr) (union sctp_addr *saddr, 541 struct dst_entry *dst, 542 __be16 port); 543 int (*cmp_addr) (const union sctp_addr *addr1, 544 const union sctp_addr *addr2); 545 void (*addr_copy) (union sctp_addr *dst, 546 union sctp_addr *src); 547 void (*from_skb) (union sctp_addr *, 548 struct sk_buff *skb, 549 int saddr); 550 void (*from_sk) (union sctp_addr *, 551 struct sock *sk); 552 void (*to_sk_saddr) (union sctp_addr *, 553 struct sock *sk); 554 void (*to_sk_daddr) (union sctp_addr *, 555 struct sock *sk); 556 void (*from_addr_param) (union sctp_addr *, 557 union sctp_addr_param *, 558 __be16 port, int iif); 559 int (*to_addr_param) (const union sctp_addr *, 560 union sctp_addr_param *); 561 int (*addr_valid) (union sctp_addr *, 562 struct sctp_sock *, 563 const struct sk_buff *); 564 sctp_scope_t (*scope) (union sctp_addr *); 565 void (*inaddr_any) (union sctp_addr *, __be16); 566 int (*is_any) (const union sctp_addr *); 567 int (*available) (union sctp_addr *, 568 struct sctp_sock *); 569 int (*skb_iif) (const struct sk_buff *sk); 570 int (*is_ce) (const struct sk_buff *sk); 571 void (*seq_dump_addr)(struct seq_file *seq, 572 union sctp_addr *addr); 573 __u16 net_header_len; 574 int sockaddr_len; 575 sa_family_t sa_family; 576 struct list_head list; 577}; 578 579struct sctp_af *sctp_get_af_specific(sa_family_t); 580int sctp_register_af(struct sctp_af *); 581 582/* Protocol family functions. */ 583struct sctp_pf { 584 void (*event_msgname)(struct sctp_ulpevent *, char *, int *); 585 void (*skb_msgname) (struct sk_buff *, char *, int *); 586 int (*af_supported) (sa_family_t, struct sctp_sock *); 587 int (*cmp_addr) (const union sctp_addr *, 588 const union sctp_addr *, 589 struct sctp_sock *); 590 int (*bind_verify) (struct sctp_sock *, union sctp_addr *); 591 int (*send_verify) (struct sctp_sock *, union sctp_addr *); 592 int (*supported_addrs)(const struct sctp_sock *, __be16 *); 593 struct sock *(*create_accept_sk) (struct sock *sk, 594 struct sctp_association *asoc); 595 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *); 596 struct sctp_af *af; 597}; 598 599 600/* Structure to track chunk fragments that have been acked, but peer 601 * fragments of the same message have not. 602 */ 603struct sctp_datamsg { 604 /* Chunks waiting to be submitted to lower layer. */ 605 struct list_head chunks; 606 /* Chunks that have been transmitted. */ 607 struct list_head track; 608 /* Reference counting. */ 609 atomic_t refcnt; 610 /* When is this message no longer interesting to the peer? */ 611 unsigned long expires_at; 612 /* Did the messenge fail to send? */ 613 int send_error; 614 char send_failed; 615 /* Control whether chunks from this message can be abandoned. */ 616 char can_abandon; 617}; 618 619struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, 620 struct sctp_sndrcvinfo *, 621 struct msghdr *, int len); 622void sctp_datamsg_put(struct sctp_datamsg *); 623void sctp_datamsg_free(struct sctp_datamsg *); 624void sctp_datamsg_track(struct sctp_chunk *); 625void sctp_chunk_fail(struct sctp_chunk *, int error); 626int sctp_chunk_abandoned(struct sctp_chunk *); 627 628/* RFC2960 1.4 Key Terms 629 * 630 * o Chunk: A unit of information within an SCTP packet, consisting of 631 * a chunk header and chunk-specific content. 632 * 633 * As a matter of convenience, we remember the SCTP common header for 634 * each chunk as well as a few other header pointers... 635 */ 636struct sctp_chunk { 637 struct list_head list; 638 639 atomic_t refcnt; 640 641 /* This is our link to the per-transport transmitted list. */ 642 struct list_head transmitted_list; 643 644 /* This field is used by chunks that hold fragmented data. 645 * For the first fragment this is the list that holds the rest of 646 * fragments. For the remaining fragments, this is the link to the 647 * frag_list maintained in the first fragment. 648 */ 649 struct list_head frag_list; 650 651 /* This points to the sk_buff containing the actual data. */ 652 struct sk_buff *skb; 653 654 /* These are the SCTP headers by reverse order in a packet. 655 * Note that some of these may happen more than once. In that 656 * case, we point at the "current" one, whatever that means 657 * for that level of header. 658 */ 659 660 /* We point this at the FIRST TLV parameter to chunk_hdr. */ 661 union sctp_params param_hdr; 662 union { 663 __u8 *v; 664 struct sctp_datahdr *data_hdr; 665 struct sctp_inithdr *init_hdr; 666 struct sctp_sackhdr *sack_hdr; 667 struct sctp_heartbeathdr *hb_hdr; 668 struct sctp_sender_hb_info *hbs_hdr; 669 struct sctp_shutdownhdr *shutdown_hdr; 670 struct sctp_signed_cookie *cookie_hdr; 671 struct sctp_ecnehdr *ecne_hdr; 672 struct sctp_cwrhdr *ecn_cwr_hdr; 673 struct sctp_errhdr *err_hdr; 674 struct sctp_addiphdr *addip_hdr; 675 struct sctp_fwdtsn_hdr *fwdtsn_hdr; 676 } subh; 677 678 __u8 *chunk_end; 679 680 struct sctp_chunkhdr *chunk_hdr; 681 struct sctphdr *sctp_hdr; 682 683 /* This needs to be recoverable for SCTP_SEND_FAILED events. */ 684 struct sctp_sndrcvinfo sinfo; 685 686 /* Which association does this belong to? */ 687 struct sctp_association *asoc; 688 689 /* What endpoint received this chunk? */ 690 struct sctp_ep_common *rcvr; 691 692 /* We fill this in if we are calculating RTT. */ 693 unsigned long sent_at; 694 695 /* What is the origin IP address for this chunk? */ 696 union sctp_addr source; 697 /* Destination address for this chunk. */ 698 union sctp_addr dest; 699 700 /* For outbound message, track all fragments for SEND_FAILED. */ 701 struct sctp_datamsg *msg; 702 703 /* For an inbound chunk, this tells us where it came from. 704 * For an outbound chunk, it tells us where we'd like it to 705 * go. It is NULL if we have no preference. 706 */ 707 struct sctp_transport *transport; 708 709 __u8 rtt_in_progress; /* Is this chunk used for RTT calculation? */ 710 __u8 resent; /* Has this chunk ever been retransmitted. */ 711 __u8 has_tsn; /* Does this chunk have a TSN yet? */ 712 __u8 has_ssn; /* Does this chunk have a SSN yet? */ 713 __u8 singleton; /* Was this the only chunk in the packet? */ 714 __u8 end_of_packet; /* Was this the last chunk in the packet? */ 715 __u8 ecn_ce_done; /* Have we processed the ECN CE bit? */ 716 __u8 pdiscard; /* Discard the whole packet now? */ 717 __u8 tsn_gap_acked; /* Is this chunk acked by a GAP ACK? */ 718 __s8 fast_retransmit; /* Is this chunk fast retransmitted? */ 719 __u8 tsn_missing_report; /* Data chunk missing counter. */ 720 __u8 data_accepted; /* At least 1 chunk in this packet accepted */ 721}; 722 723void sctp_chunk_hold(struct sctp_chunk *); 724void sctp_chunk_put(struct sctp_chunk *); 725int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 726 struct iovec *data); 727void sctp_chunk_free(struct sctp_chunk *); 728void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); 729struct sctp_chunk *sctp_chunkify(struct sk_buff *, 730 const struct sctp_association *, 731 struct sock *); 732void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, 733 union sctp_addr *); 734const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); 735 736/* This is a structure for holding either an IPv6 or an IPv4 address. */ 737struct sctp_sockaddr_entry { 738 struct list_head list; 739 union sctp_addr a; 740 __u8 use_as_src; 741}; 742 743typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *); 744 745/* This structure holds lists of chunks as we are assembling for 746 * transmission. 747 */ 748struct sctp_packet { 749 /* These are the SCTP header values (host order) for the packet. */ 750 __u16 source_port; 751 __u16 destination_port; 752 __u32 vtag; 753 754 /* This contains the payload chunks. */ 755 struct list_head chunk_list; 756 757 /* This is the overhead of the sctp and ip headers. */ 758 size_t overhead; 759 /* This is the total size of all chunks INCLUDING padding. */ 760 size_t size; 761 762 /* The packet is destined for this transport address. 763 * The function we finally use to pass down to the next lower 764 * layer lives in the transport structure. 765 */ 766 struct sctp_transport *transport; 767 768 /* This packet contains a COOKIE-ECHO chunk. */ 769 char has_cookie_echo; 770 771 /* This packet containsa SACK chunk. */ 772 char has_sack; 773 774 /* SCTP cannot fragment this packet. So let ip fragment it. */ 775 char ipfragok; 776 777 int malloced; 778}; 779 780struct sctp_packet *sctp_packet_init(struct sctp_packet *, 781 struct sctp_transport *, 782 __u16 sport, __u16 dport); 783struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int); 784sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *, 785 struct sctp_chunk *); 786sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *, 787 struct sctp_chunk *); 788int sctp_packet_transmit(struct sctp_packet *); 789void sctp_packet_free(struct sctp_packet *); 790 791static inline int sctp_packet_empty(struct sctp_packet *packet) 792{ 793 return (packet->size == packet->overhead); 794} 795 796/* This represents a remote transport address. 797 * For local transport addresses, we just use union sctp_addr. 798 * 799 * RFC2960 Section 1.4 Key Terms 800 * 801 * o Transport address: A Transport Address is traditionally defined 802 * by Network Layer address, Transport Layer protocol and Transport 803 * Layer port number. In the case of SCTP running over IP, a 804 * transport address is defined by the combination of an IP address 805 * and an SCTP port number (where SCTP is the Transport protocol). 806 * 807 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control 808 * 809 * o The sender keeps a separate congestion control parameter set for 810 * each of the destination addresses it can send to (not each 811 * source-destination pair but for each destination). The parameters 812 * should decay if the address is not used for a long enough time 813 * period. 814 * 815 */ 816struct sctp_transport { 817 /* A list of transports. */ 818 struct list_head transports; 819 820 /* Reference counting. */ 821 atomic_t refcnt; 822 int dead; 823 824 /* This is the peer's IP address and port. */ 825 union sctp_addr ipaddr; 826 827 /* These are the functions we call to handle LLP stuff. */ 828 struct sctp_af *af_specific; 829 830 /* Which association do we belong to? */ 831 struct sctp_association *asoc; 832 833 /* RFC2960 834 * 835 * 12.3 Per Transport Address Data 836 * 837 * For each destination transport address in the peer's 838 * address list derived from the INIT or INIT ACK chunk, a 839 * number of data elements needs to be maintained including: 840 */ 841 __u32 rtt; /* This is the most recent RTT. */ 842 843 /* RTO : The current retransmission timeout value. */ 844 unsigned long rto; 845 846 /* RTTVAR : The current RTT variation. */ 847 __u32 rttvar; 848 849 /* SRTT : The current smoothed round trip time. */ 850 __u32 srtt; 851 852 /* RTO-Pending : A flag used to track if one of the DATA 853 * chunks sent to this address is currently being 854 * used to compute a RTT. If this flag is 0, 855 * the next DATA chunk sent to this destination 856 * should be used to compute a RTT and this flag 857 * should be set. Every time the RTT 858 * calculation completes (i.e. the DATA chunk 859 * is SACK'd) clear this flag. 860 */ 861 int rto_pending; 862 863 /* 864 * These are the congestion stats. 865 */ 866 /* cwnd : The current congestion window. */ 867 __u32 cwnd; /* This is the actual cwnd. */ 868 869 /* ssthresh : The current slow start threshold value. */ 870 __u32 ssthresh; 871 872 /* partial : The tracking method for increase of cwnd when in 873 * bytes acked : congestion avoidance mode (see Section 6.2.2) 874 */ 875 __u32 partial_bytes_acked; 876 877 /* Data that has been sent, but not acknowledged. */ 878 __u32 flight_size; 879 880 /* Destination */ 881 struct dst_entry *dst; 882 /* Source address. */ 883 union sctp_addr saddr; 884 885 /* When was the last time(in jiffies) that a data packet was sent on 886 * this transport? This is used to adjust the cwnd when the transport 887 * becomes inactive. 888 */ 889 unsigned long last_time_used; 890 891 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 892 * the destination address every heartbeat interval. 893 */ 894 unsigned long hbinterval; 895 896 /* SACK delay timeout */ 897 unsigned long sackdelay; 898 899 /* When was the last time (in jiffies) that we heard from this 900 * transport? We use this to pick new active and retran paths. 901 */ 902 unsigned long last_time_heard; 903 904 /* Last time(in jiffies) when cwnd is reduced due to the congestion 905 * indication based on ECNE chunk. 906 */ 907 unsigned long last_time_ecne_reduced; 908 909 /* This is the max_retrans value for the transport and will 910 * be initialized from the assocs value. This can be changed 911 * using SCTP_SET_PEER_ADDR_PARAMS socket option. 912 */ 913 __u16 pathmaxrxt; 914 915 /* is the Path MTU update pending on this tranport */ 916 __u8 pmtu_pending; 917 918 /* PMTU : The current known path MTU. */ 919 __u32 pathmtu; 920 921 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 922 __u32 param_flags; 923 924 /* The number of times INIT has been sent on this transport. */ 925 int init_sent_count; 926 927 /* state : The current state of this destination, 928 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKOWN. 929 */ 930 int state; 931 932 /* These are the error stats for this destination. */ 933 934 /* Error count : The current error count for this destination. */ 935 unsigned short error_count; 936 937 /* Per : A timer used by each destination. 938 * Destination : 939 * Timer : 940 * 941 * [Everywhere else in the text this is called T3-rtx. -ed] 942 */ 943 struct timer_list T3_rtx_timer; 944 945 /* Heartbeat timer is per destination. */ 946 struct timer_list hb_timer; 947 948 /* Since we're using per-destination retransmission timers 949 * (see above), we're also using per-destination "transmitted" 950 * queues. This probably ought to be a private struct 951 * accessible only within the outqueue, but it's not, yet. 952 */ 953 struct list_head transmitted; 954 955 /* We build bundle-able packets for this transport here. */ 956 struct sctp_packet packet; 957 958 /* This is the list of transports that have chunks to send. */ 959 struct list_head send_ready; 960 961 int malloced; /* Is this structure kfree()able? */ 962 963 /* State information saved for SFR_CACC algorithm. The key 964 * idea in SFR_CACC is to maintain state at the sender on a 965 * per-destination basis when a changeover happens. 966 * char changeover_active; 967 * char cycling_changeover; 968 * __u32 next_tsn_at_change; 969 * char cacc_saw_newack; 970 */ 971 struct { 972 /* An unsigned integer, which stores the next TSN to be 973 * used by the sender, at the moment of changeover. 974 */ 975 __u32 next_tsn_at_change; 976 977 /* A flag which indicates the occurrence of a changeover */ 978 char changeover_active; 979 980 /* A flag which indicates whether the change of primary is 981 * the first switch to this destination address during an 982 * active switch. 983 */ 984 char cycling_changeover; 985 986 /* A temporary flag, which is used during the processing of 987 * a SACK to estimate the causative TSN(s)'s group. 988 */ 989 char cacc_saw_newack; 990 } cacc; 991 992 /* 64-bit random number sent with heartbeat. */ 993 __u64 hb_nonce; 994}; 995 996struct sctp_transport *sctp_transport_new(const union sctp_addr *, 997 gfp_t); 998void sctp_transport_set_owner(struct sctp_transport *, 999 struct sctp_association *); 1000void sctp_transport_route(struct sctp_transport *, union sctp_addr *, 1001 struct sctp_sock *); 1002void sctp_transport_pmtu(struct sctp_transport *); 1003void sctp_transport_free(struct sctp_transport *); 1004void sctp_transport_reset_timers(struct sctp_transport *); 1005void sctp_transport_hold(struct sctp_transport *); 1006void sctp_transport_put(struct sctp_transport *); 1007void sctp_transport_update_rto(struct sctp_transport *, __u32); 1008void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32); 1009void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t); 1010unsigned long sctp_transport_timeout(struct sctp_transport *); 1011void sctp_transport_reset(struct sctp_transport *); 1012void sctp_transport_update_pmtu(struct sctp_transport *, u32); 1013 1014 1015/* This is the structure we use to queue packets as they come into 1016 * SCTP. We write packets to it and read chunks from it. 1017 */ 1018struct sctp_inq { 1019 /* This is actually a queue of sctp_chunk each 1020 * containing a partially decoded packet. 1021 */ 1022 struct list_head in_chunk_list; 1023 /* This is the packet which is currently off the in queue and is 1024 * being worked on through the inbound chunk processing. 1025 */ 1026 struct sctp_chunk *in_progress; 1027 1028 /* This is the delayed task to finish delivering inbound 1029 * messages. 1030 */ 1031 struct work_struct immediate; 1032 1033 int malloced; /* Is this structure kfree()able? */ 1034}; 1035 1036void sctp_inq_init(struct sctp_inq *); 1037void sctp_inq_free(struct sctp_inq *); 1038void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet); 1039struct sctp_chunk *sctp_inq_pop(struct sctp_inq *); 1040void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t); 1041 1042/* This is the structure we use to hold outbound chunks. You push 1043 * chunks in and they automatically pop out the other end as bundled 1044 * packets (it calls (*output_handler)()). 1045 * 1046 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1, 1047 * and 8.2 of the v13 draft. 1048 * 1049 * It handles retransmissions. The connection to the timeout portion 1050 * of the state machine is through sctp_..._timeout() and timeout_handler. 1051 * 1052 * If you feed it SACKs, it will eat them. 1053 * 1054 * If you give it big chunks, it will fragment them. 1055 * 1056 * It assigns TSN's to data chunks. This happens at the last possible 1057 * instant before transmission. 1058 * 1059 * When free()'d, it empties itself out via output_handler(). 1060 */ 1061struct sctp_outq { 1062 struct sctp_association *asoc; 1063 1064 /* Data pending that has never been transmitted. */ 1065 struct list_head out_chunk_list; 1066 1067 unsigned out_qlen; /* Total length of queued data chunks. */ 1068 1069 /* Error of send failed, may used in SCTP_SEND_FAILED event. */ 1070 unsigned error; 1071 1072 /* These are control chunks we want to send. */ 1073 struct list_head control_chunk_list; 1074 1075 /* These are chunks that have been sacked but are above the 1076 * CTSN, or cumulative tsn ack point. 1077 */ 1078 struct list_head sacked; 1079 1080 /* Put chunks on this list to schedule them for 1081 * retransmission. 1082 */ 1083 struct list_head retransmit; 1084 1085 /* Put chunks on this list to save them for FWD TSN processing as 1086 * they were abandoned. 1087 */ 1088 struct list_head abandoned; 1089 1090 /* How many unackd bytes do we have in-flight? */ 1091 __u32 outstanding_bytes; 1092 1093 /* Corked? */ 1094 char cork; 1095 1096 /* Is this structure empty? */ 1097 char empty; 1098 1099 /* Are we kfree()able? */ 1100 char malloced; 1101}; 1102 1103void sctp_outq_init(struct sctp_association *, struct sctp_outq *); 1104void sctp_outq_teardown(struct sctp_outq *); 1105void sctp_outq_free(struct sctp_outq*); 1106int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk); 1107int sctp_outq_flush(struct sctp_outq *, int); 1108int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *); 1109int sctp_outq_is_empty(const struct sctp_outq *); 1110void sctp_outq_restart(struct sctp_outq *); 1111 1112void sctp_retransmit(struct sctp_outq *, struct sctp_transport *, 1113 sctp_retransmit_reason_t); 1114void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); 1115int sctp_outq_uncork(struct sctp_outq *); 1116/* Uncork and flush an outqueue. */ 1117static inline void sctp_outq_cork(struct sctp_outq *q) 1118{ 1119 q->cork = 1; 1120} 1121 1122/* These bind address data fields common between endpoints and associations */ 1123struct sctp_bind_addr { 1124 1125 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1126 * 1127 * SCTP Port: The local SCTP port number the endpoint is 1128 * bound to. 1129 */ 1130 __u16 port; 1131 1132 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1133 * 1134 * Address List: The list of IP addresses that this instance 1135 * has bound. This information is passed to one's 1136 * peer(s) in INIT and INIT ACK chunks. 1137 */ 1138 struct list_head address_list; 1139 1140 int malloced; /* Are we kfree()able? */ 1141}; 1142 1143void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port); 1144void sctp_bind_addr_free(struct sctp_bind_addr *); 1145int sctp_bind_addr_copy(struct sctp_bind_addr *dest, 1146 const struct sctp_bind_addr *src, 1147 sctp_scope_t scope, gfp_t gfp, 1148 int flags); 1149int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1150 __u8 use_as_src, gfp_t gfp); 1151int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *); 1152int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, 1153 struct sctp_sock *); 1154union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 1155 const union sctp_addr *addrs, 1156 int addrcnt, 1157 struct sctp_sock *opt); 1158union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 1159 int *addrs_len, 1160 gfp_t gfp); 1161int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, 1162 __u16 port, gfp_t gfp); 1163 1164sctp_scope_t sctp_scope(const union sctp_addr *); 1165int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope); 1166int sctp_is_any(const union sctp_addr *addr); 1167int sctp_addr_is_valid(const union sctp_addr *addr); 1168 1169 1170/* What type of endpoint? */ 1171typedef enum { 1172 SCTP_EP_TYPE_SOCKET, 1173 SCTP_EP_TYPE_ASSOCIATION, 1174} sctp_endpoint_type_t; 1175 1176/* 1177 * A common base class to bridge the implmentation view of a 1178 * socket (usually listening) endpoint versus an association's 1179 * local endpoint. 1180 * This common structure is useful for several purposes: 1181 * 1) Common interface for lookup routines. 1182 * a) Subfunctions work for either endpoint or association 1183 * b) Single interface to lookup allows hiding the lookup lock rather 1184 * than acquiring it externally. 1185 * 2) Common interface for the inbound chunk handling/state machine. 1186 * 3) Common object handling routines for reference counting, etc. 1187 * 4) Disentangle association lookup from endpoint lookup, where we 1188 * do not have to find our endpoint to find our association. 1189 * 1190 */ 1191 1192struct sctp_ep_common { 1193 /* Fields to help us manage our entries in the hash tables. */ 1194 struct sctp_ep_common *next; 1195 struct sctp_ep_common **pprev; 1196 int hashent; 1197 1198 /* Runtime type information. What kind of endpoint is this? */ 1199 sctp_endpoint_type_t type; 1200 1201 /* Some fields to help us manage this object. 1202 * refcnt - Reference count access to this object. 1203 * dead - Do not attempt to use this object. 1204 * malloced - Do we need to kfree this object? 1205 */ 1206 atomic_t refcnt; 1207 char dead; 1208 char malloced; 1209 1210 /* What socket does this endpoint belong to? */ 1211 struct sock *sk; 1212 1213 /* This is where we receive inbound chunks. */ 1214 struct sctp_inq inqueue; 1215 1216 /* This substructure includes the defining parameters of the 1217 * endpoint: 1218 * bind_addr.port is our shared port number. 1219 * bind_addr.address_list is our set of local IP addresses. 1220 */ 1221 struct sctp_bind_addr bind_addr; 1222 1223 /* Protection during address list comparisons. */ 1224 rwlock_t addr_lock; 1225}; 1226 1227 1228/* RFC Section 1.4 Key Terms 1229 * 1230 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a 1231 * multi-homed host, an SCTP endpoint is represented to its peers as a 1232 * combination of a set of eligible destination transport addresses to 1233 * which SCTP packets can be sent and a set of eligible source 1234 * transport addresses from which SCTP packets can be received. 1235 * All transport addresses used by an SCTP endpoint must use the 1236 * same port number, but can use multiple IP addresses. A transport 1237 * address used by an SCTP endpoint must not be used by another 1238 * SCTP endpoint. In other words, a transport address is unique 1239 * to an SCTP endpoint. 1240 * 1241 * From an implementation perspective, each socket has one of these. 1242 * A TCP-style socket will have exactly one association on one of 1243 * these. An UDP-style socket will have multiple associations hanging 1244 * off one of these. 1245 */ 1246 1247struct sctp_endpoint { 1248 /* Common substructure for endpoint and association. */ 1249 struct sctp_ep_common base; 1250 1251 /* Associations: A list of current associations and mappings 1252 * to the data consumers for each association. This 1253 * may be in the form of a hash table or other 1254 * implementation dependent structure. The data 1255 * consumers may be process identification 1256 * information such as file descriptors, named pipe 1257 * pointer, or table pointers dependent on how SCTP 1258 * is implemented. 1259 */ 1260 /* This is really a list of struct sctp_association entries. */ 1261 struct list_head asocs; 1262 1263 /* Secret Key: A secret key used by this endpoint to compute 1264 * the MAC. This SHOULD be a cryptographic quality 1265 * random number with a sufficient length. 1266 * Discussion in [RFC1750] can be helpful in 1267 * selection of the key. 1268 */ 1269 __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE]; 1270 int current_key; 1271 int last_key; 1272 int key_changed_at; 1273 1274 /* digest: This is a digest of the sctp cookie. This field is 1275 * only used on the receive path when we try to validate 1276 * that the cookie has not been tampered with. We put 1277 * this here so we pre-allocate this once and can re-use 1278 * on every receive. 1279 */ 1280 __u8 *digest; 1281 1282 /* sendbuf acct. policy. */ 1283 __u32 sndbuf_policy; 1284 1285 /* rcvbuf acct. policy. */ 1286 __u32 rcvbuf_policy; 1287}; 1288 1289/* Recover the outter endpoint structure. */ 1290static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) 1291{ 1292 struct sctp_endpoint *ep; 1293 1294 ep = container_of(base, struct sctp_endpoint, base); 1295 return ep; 1296} 1297 1298/* These are function signatures for manipulating endpoints. */ 1299struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t); 1300void sctp_endpoint_free(struct sctp_endpoint *); 1301void sctp_endpoint_put(struct sctp_endpoint *); 1302void sctp_endpoint_hold(struct sctp_endpoint *); 1303void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); 1304struct sctp_association *sctp_endpoint_lookup_assoc( 1305 const struct sctp_endpoint *ep, 1306 const union sctp_addr *paddr, 1307 struct sctp_transport **); 1308int sctp_endpoint_is_peeled_off(struct sctp_endpoint *, 1309 const union sctp_addr *); 1310struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *, 1311 const union sctp_addr *); 1312int sctp_has_association(const union sctp_addr *laddr, 1313 const union sctp_addr *paddr); 1314 1315int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t, 1316 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk, 1317 struct sctp_chunk **err_chunk); 1318int sctp_process_init(struct sctp_association *, sctp_cid_t cid, 1319 const union sctp_addr *peer, 1320 sctp_init_chunk_t *init, gfp_t gfp); 1321__u32 sctp_generate_tag(const struct sctp_endpoint *); 1322__u32 sctp_generate_tsn(const struct sctp_endpoint *); 1323 1324struct sctp_inithdr_host { 1325 __u32 init_tag; 1326 __u32 a_rwnd; 1327 __u16 num_outbound_streams; 1328 __u16 num_inbound_streams; 1329 __u32 initial_tsn; 1330}; 1331 1332/* RFC2960 1333 * 1334 * 12. Recommended Transmission Control Block (TCB) Parameters 1335 * 1336 * This section details a recommended set of parameters that should 1337 * be contained within the TCB for an implementation. This section is 1338 * for illustrative purposes and should not be deemed as requirements 1339 * on an implementation or as an exhaustive list of all parameters 1340 * inside an SCTP TCB. Each implementation may need its own additional 1341 * parameters for optimization. 1342 */ 1343 1344 1345/* Here we have information about each individual association. */ 1346struct sctp_association { 1347 1348 /* A base structure common to endpoint and association. 1349 * In this context, it represents the associations's view 1350 * of the local endpoint of the association. 1351 */ 1352 struct sctp_ep_common base; 1353 1354 /* Associations on the same socket. */ 1355 struct list_head asocs; 1356 1357 /* association id. */ 1358 sctp_assoc_t assoc_id; 1359 1360 /* This is our parent endpoint. */ 1361 struct sctp_endpoint *ep; 1362 1363 /* These are those association elements needed in the cookie. */ 1364 struct sctp_cookie c; 1365 1366 /* This is all information about our peer. */ 1367 struct { 1368 /* rwnd 1369 * 1370 * Peer Rwnd : Current calculated value of the peer's rwnd. 1371 */ 1372 __u32 rwnd; 1373 1374 /* transport_addr_list 1375 * 1376 * Peer : A list of SCTP transport addresses that the 1377 * Transport : peer is bound to. This information is derived 1378 * Address : from the INIT or INIT ACK and is used to 1379 * List : associate an inbound packet with a given 1380 * : association. Normally this information is 1381 * : hashed or keyed for quick lookup and access 1382 * : of the TCB. 1383 * : The list is also initialized with the list 1384 * : of addresses passed with the sctp_connectx() 1385 * : call. 1386 * 1387 * It is a list of SCTP_transport's. 1388 */ 1389 struct list_head transport_addr_list; 1390 1391 /* transport_count 1392 * 1393 * Peer : A count of the number of peer addresses 1394 * Transport : in the Peer Transport Address List. 1395 * Address : 1396 * Count : 1397 */ 1398 __u16 transport_count; 1399 1400 /* port 1401 * The transport layer port number. 1402 */ 1403 __u16 port; 1404 1405 /* primary_path 1406 * 1407 * Primary : This is the current primary destination 1408 * Path : transport address of the peer endpoint. It 1409 * : may also specify a source transport address 1410 * : on this endpoint. 1411 * 1412 * All of these paths live on transport_addr_list. 1413 * 1414 * At the bakeoffs, we discovered that the intent of 1415 * primaryPath is that it only changes when the ULP 1416 * asks to have it changed. We add the activePath to 1417 * designate the connection we are currently using to 1418 * transmit new data and most control chunks. 1419 */ 1420 struct sctp_transport *primary_path; 1421 1422 /* Cache the primary path address here, when we 1423 * need a an address for msg_name. 1424 */ 1425 union sctp_addr primary_addr; 1426 1427 /* active_path 1428 * The path that we are currently using to 1429 * transmit new data and most control chunks. 1430 */ 1431 struct sctp_transport *active_path; 1432 1433 /* retran_path 1434 * 1435 * RFC2960 6.4 Multi-homed SCTP Endpoints 1436 * ... 1437 * Furthermore, when its peer is multi-homed, an 1438 * endpoint SHOULD try to retransmit a chunk to an 1439 * active destination transport address that is 1440 * different from the last destination address to 1441 * which the DATA chunk was sent. 1442 */ 1443 struct sctp_transport *retran_path; 1444 1445 /* Pointer to last transport I have sent on. */ 1446 struct sctp_transport *last_sent_to; 1447 1448 /* This is the last transport I have received DATA on. */ 1449 struct sctp_transport *last_data_from; 1450 1451 /* 1452 * Mapping An array of bits or bytes indicating which out of 1453 * Array order TSN's have been received (relative to the 1454 * Last Rcvd TSN). If no gaps exist, i.e. no out of 1455 * order packets have been received, this array 1456 * will be set to all zero. This structure may be 1457 * in the form of a circular buffer or bit array. 1458 * 1459 * Last Rcvd : This is the last TSN received in 1460 * TSN : sequence. This value is set initially by 1461 * : taking the peer's Initial TSN, received in 1462 * : the INIT or INIT ACK chunk, and subtracting 1463 * : one from it. 1464 * 1465 * Throughout most of the specification this is called the 1466 * "Cumulative TSN ACK Point". In this case, we 1467 * ignore the advice in 12.2 in favour of the term 1468 * used in the bulk of the text. This value is hidden 1469 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). 1470 */ 1471 struct sctp_tsnmap tsn_map; 1472 __u8 _map[sctp_tsnmap_storage_size(SCTP_TSN_MAP_SIZE)]; 1473 1474 /* Ack State : This flag indicates if the next received 1475 * : packet is to be responded to with a 1476 * : SACK. This is initializedto 0. When a packet 1477 * : is received it is incremented. If this value 1478 * : reaches 2 or more, a SACK is sent and the 1479 * : value is reset to 0. Note: This is used only 1480 * : when no DATA chunks are received out of 1481 * : order. When DATA chunks are out of order, 1482 * : SACK's are not delayed (see Section 6). 1483 */ 1484 __u8 sack_needed; /* Do we need to sack the peer? */ 1485 1486 /* These are capabilities which our peer advertised. */ 1487 __u8 ecn_capable; /* Can peer do ECN? */ 1488 __u8 ipv4_address; /* Peer understands IPv4 addresses? */ 1489 __u8 ipv6_address; /* Peer understands IPv6 addresses? */ 1490 __u8 hostname_address;/* Peer understands DNS addresses? */ 1491 __u8 asconf_capable; /* Does peer support ADDIP? */ 1492 __u8 prsctp_capable; /* Can peer do PR-SCTP? */ 1493 1494 __u32 adaptation_ind; /* Adaptation Code point. */ 1495 1496 /* This mask is used to disable sending the ASCONF chunk 1497 * with specified parameter to peer. 1498 */ 1499 __be16 addip_disabled_mask; 1500 1501 struct sctp_inithdr_host i; 1502 int cookie_len; 1503 void *cookie; 1504 1505 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1506 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the 1507 * Initial TSN Value minus 1 1508 */ 1509 __u32 addip_serial; 1510 } peer; 1511 1512 /* State : A state variable indicating what state the 1513 * : association is in, i.e. COOKIE-WAIT, 1514 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, 1515 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. 1516 * 1517 * Note: No "CLOSED" state is illustrated since if a 1518 * association is "CLOSED" its TCB SHOULD be removed. 1519 * 1520 * In this implementation we DO have a CLOSED 1521 * state which is used during initiation and shutdown. 1522 * 1523 * State takes values from SCTP_STATE_*. 1524 */ 1525 sctp_state_t state; 1526 1527 /* The cookie life I award for any cookie. */ 1528 struct timeval cookie_life; 1529 1530 /* Overall : The overall association error count. 1531 * Error Count : [Clear this any time I get something.] 1532 */ 1533 int overall_error_count; 1534 1535 /* These are the association's initial, max, and min RTO values. 1536 * These values will be initialized by system defaults, but can 1537 * be modified via the SCTP_RTOINFO socket option. 1538 */ 1539 unsigned long rto_initial; 1540 unsigned long rto_max; 1541 unsigned long rto_min; 1542 1543 /* Maximum number of new data packets that can be sent in a burst. */ 1544 int max_burst; 1545 1546 /* This is the max_retrans value for the association. This value will 1547 * be initialized initialized from system defaults, but can be 1548 * modified by the SCTP_ASSOCINFO socket option. 1549 */ 1550 int max_retrans; 1551 1552 /* Maximum number of times the endpoint will retransmit INIT */ 1553 __u16 max_init_attempts; 1554 1555 /* How many times have we resent an INIT? */ 1556 __u16 init_retries; 1557 1558 /* The largest timeout or RTO value to use in attempting an INIT */ 1559 unsigned long max_init_timeo; 1560 1561 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 1562 * the destination address every heartbeat interval. This value 1563 * will be inherited by all new transports. 1564 */ 1565 unsigned long hbinterval; 1566 1567 /* This is the max_retrans value for new transports in the 1568 * association. 1569 */ 1570 __u16 pathmaxrxt; 1571 1572 /* Flag that path mtu update is pending */ 1573 __u8 pmtu_pending; 1574 1575 /* Association : The smallest PMTU discovered for all of the 1576 * PMTU : peer's transport addresses. 1577 */ 1578 __u32 pathmtu; 1579 1580 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 1581 __u32 param_flags; 1582 1583 /* SACK delay timeout */ 1584 unsigned long sackdelay; 1585 1586 1587 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1588 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; 1589 1590 /* Transport to which SHUTDOWN chunk was last sent. */ 1591 struct sctp_transport *shutdown_last_sent_to; 1592 1593 /* Transport to which INIT chunk was last sent. */ 1594 struct sctp_transport *init_last_sent_to; 1595 1596 /* Next TSN : The next TSN number to be assigned to a new 1597 * : DATA chunk. This is sent in the INIT or INIT 1598 * : ACK chunk to the peer and incremented each 1599 * : time a DATA chunk is assigned a TSN 1600 * : (normally just prior to transmit or during 1601 * : fragmentation). 1602 */ 1603 __u32 next_tsn; 1604 1605 /* 1606 * Last Rcvd : This is the last TSN received in sequence. This value 1607 * TSN : is set initially by taking the peer's Initial TSN, 1608 * : received in the INIT or INIT ACK chunk, and 1609 * : subtracting one from it. 1610 * 1611 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. 1612 */ 1613 1614 __u32 ctsn_ack_point; 1615 1616 /* PR-SCTP Advanced.Peer.Ack.Point */ 1617 __u32 adv_peer_ack_point; 1618 1619 /* Highest TSN that is acknowledged by incoming SACKs. */ 1620 __u32 highest_sacked; 1621 1622 /* The number of unacknowledged data chunks. Reported through 1623 * the SCTP_STATUS sockopt. 1624 */ 1625 __u16 unack_data; 1626 1627 /* This is the association's receive buffer space. This value is used 1628 * to set a_rwnd field in an INIT or a SACK chunk. 1629 */ 1630 __u32 rwnd; 1631 1632 /* This is the last advertised value of rwnd over a SACK chunk. */ 1633 __u32 a_rwnd; 1634 1635 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed 1636 * to slop over a maximum of the association's frag_point. 1637 */ 1638 __u32 rwnd_over; 1639 1640 /* This is the sndbuf size in use for the association. 1641 * This corresponds to the sndbuf size for the association, 1642 * as specified in the sk->sndbuf. 1643 */ 1644 int sndbuf_used; 1645 1646 /* This is the amount of memory that this association has allocated 1647 * in the receive path at any given time. 1648 */ 1649 atomic_t rmem_alloc; 1650 1651 /* This is the wait queue head for send requests waiting on 1652 * the association sndbuf space. 1653 */ 1654 wait_queue_head_t wait; 1655 1656 /* The message size at which SCTP fragmentation will occur. */ 1657 __u32 frag_point; 1658 1659 /* Counter used to count INIT errors. */ 1660 int init_err_counter; 1661 1662 /* Count the number of INIT cycles (for doubling timeout). */ 1663 int init_cycle; 1664 1665 /* Default send parameters. */ 1666 __u16 default_stream; 1667 __u16 default_flags; 1668 __u32 default_ppid; 1669 __u32 default_context; 1670 __u32 default_timetolive; 1671 1672 /* Default receive parameters */ 1673 __u32 default_rcv_context; 1674 1675 /* This tracks outbound ssn for a given stream. */ 1676 struct sctp_ssnmap *ssnmap; 1677 1678 /* All outbound chunks go through this structure. */ 1679 struct sctp_outq outqueue; 1680 1681 /* A smart pipe that will handle reordering and fragmentation, 1682 * as well as handle passing events up to the ULP. 1683 */ 1684 struct sctp_ulpq ulpq; 1685 1686 /* Last TSN that caused an ECNE Chunk to be sent. */ 1687 __u32 last_ecne_tsn; 1688 1689 /* Last TSN that caused a CWR Chunk to be sent. */ 1690 __u32 last_cwr_tsn; 1691 1692 /* How many duplicated TSNs have we seen? */ 1693 int numduptsns; 1694 1695 /* Number of seconds of idle time before an association is closed. 1696 * In the association context, this is really used as a boolean 1697 * since the real timeout is stored in the timeouts array 1698 */ 1699 __u32 autoclose; 1700 1701 /* These are to support 1702 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses 1703 * and Enforcement of Flow and Message Limits" 1704 * <draft-ietf-tsvwg-addip-sctp-02.txt> 1705 * or "ADDIP" for short. 1706 */ 1707 1708 1709 1710 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1711 * 1712 * R1) One and only one ASCONF Chunk MAY be in transit and 1713 * unacknowledged at any one time. If a sender, after sending 1714 * an ASCONF chunk, decides it needs to transfer another 1715 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1716 * returns from the previous ASCONF Chunk before sending a 1717 * subsequent ASCONF. Note this restriction binds each side, 1718 * so at any time two ASCONF may be in-transit on any given 1719 * association (one sent from each endpoint). 1720 * 1721 * [This is our one-and-only-one ASCONF in flight. If we do 1722 * not have an ASCONF in flight, this is NULL.] 1723 */ 1724 struct sctp_chunk *addip_last_asconf; 1725 1726 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1727 * 1728 * IMPLEMENTATION NOTE: As an optimization a receiver may wish 1729 * to save the last ASCONF-ACK for some predetermined period 1730 * of time and instead of re-processing the ASCONF (with the 1731 * same serial number) it may just re-transmit the 1732 * ASCONF-ACK. It may wish to use the arrival of a new serial 1733 * number to discard the previously saved ASCONF-ACK or any 1734 * other means it may choose to expire the saved ASCONF-ACK. 1735 * 1736 * [This is our saved ASCONF-ACK. We invalidate it when a new 1737 * ASCONF serial number arrives.] 1738 */ 1739 struct sctp_chunk *addip_last_asconf_ack; 1740 1741 /* These ASCONF chunks are waiting to be sent. 1742 * 1743 * These chunaks can't be pushed to outqueue until receiving 1744 * ASCONF_ACK for the previous ASCONF indicated by 1745 * addip_last_asconf, so as to guarantee that only one ASCONF 1746 * is in flight at any time. 1747 * 1748 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1749 * 1750 * In defining the ASCONF Chunk transfer procedures, it is 1751 * essential that these transfers MUST NOT cause congestion 1752 * within the network. To achieve this, we place these 1753 * restrictions on the transfer of ASCONF Chunks: 1754 * 1755 * R1) One and only one ASCONF Chunk MAY be in transit and 1756 * unacknowledged at any one time. If a sender, after sending 1757 * an ASCONF chunk, decides it needs to transfer another 1758 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1759 * returns from the previous ASCONF Chunk before sending a 1760 * subsequent ASCONF. Note this restriction binds each side, 1761 * so at any time two ASCONF may be in-transit on any given 1762 * association (one sent from each endpoint). 1763 * 1764 * 1765 * [I really think this is EXACTLY the sort of intelligence 1766 * which already resides in sctp_outq. Please move this 1767 * queue and its supporting logic down there. --piggy] 1768 */ 1769 struct list_head addip_chunk_list; 1770 1771 /* ADDIP Section 4.1 ASCONF Chunk Procedures 1772 * 1773 * A2) A serial number should be assigned to the Chunk. The 1774 * serial number SHOULD be a monotonically increasing 1775 * number. The serial number SHOULD be initialized at 1776 * the start of the association to the same value as the 1777 * Initial TSN and every time a new ASCONF chunk is created 1778 * it is incremented by one after assigning the serial number 1779 * to the newly created chunk. 1780 * 1781 * ADDIP 1782 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) 1783 * 1784 * Serial Number : 32 bits (unsigned integer) 1785 * 1786 * This value represents a Serial Number for the ASCONF 1787 * Chunk. The valid range of Serial Number is from 0 to 1788 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 1789 * after reaching 4294967295. 1790 */ 1791 __u32 addip_serial; 1792 1793 /* Need to send an ECNE Chunk? */ 1794 char need_ecne; 1795 1796 /* Is it a temporary association? */ 1797 char temp; 1798}; 1799 1800 1801/* An eyecatcher for determining if we are really looking at an 1802 * association data structure. 1803 */ 1804enum { 1805 SCTP_ASSOC_EYECATCHER = 0xa550c123, 1806}; 1807 1808/* Recover the outter association structure. */ 1809static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) 1810{ 1811 struct sctp_association *asoc; 1812 1813 asoc = container_of(base, struct sctp_association, base); 1814 return asoc; 1815} 1816 1817/* These are function signatures for manipulating associations. */ 1818 1819 1820struct sctp_association * 1821sctp_association_new(const struct sctp_endpoint *, const struct sock *, 1822 sctp_scope_t scope, gfp_t gfp); 1823void sctp_association_free(struct sctp_association *); 1824void sctp_association_put(struct sctp_association *); 1825void sctp_association_hold(struct sctp_association *); 1826 1827struct sctp_transport *sctp_assoc_choose_init_transport( 1828 struct sctp_association *); 1829struct sctp_transport *sctp_assoc_choose_shutdown_transport( 1830 struct sctp_association *); 1831void sctp_assoc_update_retran_path(struct sctp_association *); 1832struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, 1833 const union sctp_addr *); 1834int sctp_assoc_lookup_laddr(struct sctp_association *asoc, 1835 const union sctp_addr *laddr); 1836struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, 1837 const union sctp_addr *address, 1838 const gfp_t gfp, 1839 const int peer_state); 1840void sctp_assoc_del_peer(struct sctp_association *asoc, 1841 const union sctp_addr *addr); 1842void sctp_assoc_rm_peer(struct sctp_association *asoc, 1843 struct sctp_transport *peer); 1844void sctp_assoc_control_transport(struct sctp_association *, 1845 struct sctp_transport *, 1846 sctp_transport_cmd_t, sctp_sn_error_t); 1847struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); 1848struct sctp_transport *sctp_assoc_is_match(struct sctp_association *, 1849 const union sctp_addr *, 1850 const union sctp_addr *); 1851void sctp_assoc_migrate(struct sctp_association *, struct sock *); 1852void sctp_assoc_update(struct sctp_association *old, 1853 struct sctp_association *new); 1854 1855__u32 sctp_association_get_next_tsn(struct sctp_association *); 1856 1857void sctp_assoc_sync_pmtu(struct sctp_association *); 1858void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned); 1859void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned); 1860void sctp_assoc_set_primary(struct sctp_association *, 1861 struct sctp_transport *); 1862int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *, 1863 gfp_t); 1864int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, 1865 struct sctp_cookie*, 1866 gfp_t gfp); 1867int sctp_assoc_set_id(struct sctp_association *, gfp_t); 1868 1869int sctp_cmp_addr_exact(const union sctp_addr *ss1, 1870 const union sctp_addr *ss2); 1871struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); 1872 1873/* A convenience structure to parse out SCTP specific CMSGs. */ 1874typedef struct sctp_cmsgs { 1875 struct sctp_initmsg *init; 1876 struct sctp_sndrcvinfo *info; 1877} sctp_cmsgs_t; 1878 1879/* Structure for tracking memory objects */ 1880typedef struct { 1881 char *label; 1882 atomic_t *counter; 1883} sctp_dbg_objcnt_entry_t; 1884 1885#endif /* __sctp_structs_h__ */ 1886