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 */ 71 union sctp_addr { 72 struct sockaddr_in v4; 73 struct sockaddr_in6 v6; 74 struct sockaddr sa; 75 }; 76 77 /* Forward declarations for data structures. */ 78 struct sctp_globals; 79 struct sctp_endpoint; 80 struct sctp_association; 81 struct sctp_transport; 82 struct sctp_packet; 83 struct sctp_chunk; 84 struct sctp_inq; 85 struct sctp_outq; 86 struct sctp_bind_addr; 87 struct sctp_ulpq; 88 struct sctp_ep_common; 89 struct sctp_ssnmap; 90 91 92 #include <net/sctp/tsnmap.h> 93 #include <net/sctp/ulpevent.h> 94 #include <net/sctp/ulpqueue.h> 95 96 /* Structures useful for managing bind/connect. */ 97 98 struct sctp_bind_bucket { 99 unsigned short port; 100 unsigned short fastreuse; 101 struct sctp_bind_bucket *next; 102 struct sctp_bind_bucket **pprev; 103 struct hlist_head owner; 104 }; 105 106 struct sctp_bind_hashbucket { 107 spinlock_t lock; 108 struct sctp_bind_bucket *chain; 109 }; 110 111 /* Used for hashing all associations. */ 112 struct sctp_hashbucket { 113 rwlock_t lock; 114 struct sctp_ep_common *chain; 115 } __attribute__((__aligned__(8))); 116 117 118 /* The SCTP globals structure. */ 119 extern struct sctp_globals { 120 /* RFC2960 Section 14. Suggested SCTP Protocol Parameter Values 121 * 122 * The following protocol parameters are RECOMMENDED: 123 * 124 * RTO.Initial - 3 seconds 125 * RTO.Min - 1 second 126 * RTO.Max - 60 seconds 127 * RTO.Alpha - 1/8 (3 when converted to right shifts.) 128 * RTO.Beta - 1/4 (2 when converted to right shifts.) 129 */ 130 __u32 rto_initial; 131 __u32 rto_min; 132 __u32 rto_max; 133 134 /* Note: rto_alpha and rto_beta are really defined as inverse 135 * powers of two to facilitate integer operations. 136 */ 137 int rto_alpha; 138 int rto_beta; 139 140 /* Max.Burst - 4 */ 141 int max_burst; 142 143 /* Valid.Cookie.Life - 60 seconds */ 144 int valid_cookie_life; 145 146 /* Whether Cookie Preservative is enabled(1) or not(0) */ 147 int cookie_preserve_enable; 148 149 /* Association.Max.Retrans - 10 attempts 150 * Path.Max.Retrans - 5 attempts (per destination address) 151 * Max.Init.Retransmits - 8 attempts 152 */ 153 int max_retrans_association; 154 int max_retrans_path; 155 int max_retrans_init; 156 157 /* 158 * Policy for preforming sctp/socket accounting 159 * 0 - do socket level accounting, all assocs share sk_sndbuf 160 * 1 - do sctp accounting, each asoc may use sk_sndbuf bytes 161 */ 162 int sndbuf_policy; 163 164 /* HB.interval - 30 seconds */ 165 int hb_interval; 166 167 /* The following variables are implementation specific. */ 168 169 /* Default initialization values to be applied to new associations. */ 170 __u16 max_instreams; 171 __u16 max_outstreams; 172 173 /* This is a list of groups of functions for each address 174 * family that we support. 175 */ 176 struct list_head address_families; 177 178 /* This is the hash of all endpoints. */ 179 int ep_hashsize; 180 struct sctp_hashbucket *ep_hashtable; 181 182 /* This is the hash of all associations. */ 183 int assoc_hashsize; 184 struct sctp_hashbucket *assoc_hashtable; 185 186 /* This is the sctp port control hash. */ 187 int port_hashsize; 188 int port_rover; 189 spinlock_t port_alloc_lock; /* Protects port_rover. */ 190 struct sctp_bind_hashbucket *port_hashtable; 191 192 /* This is the global local address list. 193 * We actively maintain this complete list of interfaces on 194 * the system by catching routing events. 195 * 196 * It is a list of sctp_sockaddr_entry. 197 */ 198 struct list_head local_addr_list; 199 spinlock_t local_addr_lock; 200 201 /* Flag to indicate if addip is enabled. */ 202 int addip_enable; 203 204 /* Flag to indicate if PR-SCTP is enabled. */ 205 int prsctp_enable; 206 } sctp_globals; 207 208 #define sctp_rto_initial (sctp_globals.rto_initial) 209 #define sctp_rto_min (sctp_globals.rto_min) 210 #define sctp_rto_max (sctp_globals.rto_max) 211 #define sctp_rto_alpha (sctp_globals.rto_alpha) 212 #define sctp_rto_beta (sctp_globals.rto_beta) 213 #define sctp_max_burst (sctp_globals.max_burst) 214 #define sctp_valid_cookie_life (sctp_globals.valid_cookie_life) 215 #define sctp_cookie_preserve_enable (sctp_globals.cookie_preserve_enable) 216 #define sctp_max_retrans_association (sctp_globals.max_retrans_association) 217 #define sctp_sndbuf_policy (sctp_globals.sndbuf_policy) 218 #define sctp_max_retrans_path (sctp_globals.max_retrans_path) 219 #define sctp_max_retrans_init (sctp_globals.max_retrans_init) 220 #define sctp_hb_interval (sctp_globals.hb_interval) 221 #define sctp_max_instreams (sctp_globals.max_instreams) 222 #define sctp_max_outstreams (sctp_globals.max_outstreams) 223 #define sctp_address_families (sctp_globals.address_families) 224 #define sctp_ep_hashsize (sctp_globals.ep_hashsize) 225 #define sctp_ep_hashtable (sctp_globals.ep_hashtable) 226 #define sctp_assoc_hashsize (sctp_globals.assoc_hashsize) 227 #define sctp_assoc_hashtable (sctp_globals.assoc_hashtable) 228 #define sctp_port_hashsize (sctp_globals.port_hashsize) 229 #define sctp_port_rover (sctp_globals.port_rover) 230 #define sctp_port_alloc_lock (sctp_globals.port_alloc_lock) 231 #define sctp_port_hashtable (sctp_globals.port_hashtable) 232 #define sctp_local_addr_list (sctp_globals.local_addr_list) 233 #define sctp_local_addr_lock (sctp_globals.local_addr_lock) 234 #define sctp_addip_enable (sctp_globals.addip_enable) 235 #define sctp_prsctp_enable (sctp_globals.prsctp_enable) 236 237 /* SCTP Socket type: UDP or TCP style. */ 238 typedef enum { 239 SCTP_SOCKET_UDP = 0, 240 SCTP_SOCKET_UDP_HIGH_BANDWIDTH, 241 SCTP_SOCKET_TCP 242 } sctp_socket_type_t; 243 244 /* Per socket SCTP information. */ 245 struct sctp_sock { 246 /* inet_sock has to be the first member of sctp_sock */ 247 struct inet_sock inet; 248 /* What kind of a socket is this? */ 249 sctp_socket_type_t type; 250 251 /* PF_ family specific functions. */ 252 struct sctp_pf *pf; 253 254 /* Access to HMAC transform. */ 255 struct crypto_tfm *hmac; 256 257 /* What is our base endpointer? */ 258 struct sctp_endpoint *ep; 259 260 struct sctp_bind_bucket *bind_hash; 261 /* Various Socket Options. */ 262 __u16 default_stream; 263 __u32 default_ppid; 264 __u16 default_flags; 265 __u32 default_context; 266 __u32 default_timetolive; 267 268 struct sctp_initmsg initmsg; 269 struct sctp_rtoinfo rtoinfo; 270 struct sctp_paddrparams paddrparam; 271 struct sctp_event_subscribe subscribe; 272 struct sctp_assocparams assocparams; 273 int user_frag; 274 __u32 autoclose; 275 __u8 nodelay; 276 __u8 disable_fragments; 277 __u8 pd_mode; 278 __u8 v4mapped; 279 __u32 adaption_ind; 280 281 /* Receive to here while partial delivery is in effect. */ 282 struct sk_buff_head pd_lobby; 283 }; 284 285 static inline struct sctp_sock *sctp_sk(const struct sock *sk) 286 { 287 return (struct sctp_sock *)sk; 288 } 289 290 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp) 291 { 292 return (struct sock *)sp; 293 } 294 295 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 296 struct sctp6_sock { 297 struct sctp_sock sctp; 298 struct ipv6_pinfo inet6; 299 }; 300 #endif /* CONFIG_IPV6 */ 301 302 303 /* This is our APPLICATION-SPECIFIC state cookie. 304 * THIS IS NOT DICTATED BY THE SPECIFICATION. 305 */ 306 /* These are the parts of an association which we send in the cookie. 307 * Most of these are straight out of: 308 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB) 309 * 310 */ 311 312 struct sctp_cookie { 313 314 /* My : Tag expected in every inbound packet and sent 315 * Verification: in the INIT or INIT ACK chunk. 316 * Tag : 317 */ 318 __u32 my_vtag; 319 320 /* Peer's : Tag expected in every outbound packet except 321 * Verification: in the INIT chunk. 322 * Tag : 323 */ 324 __u32 peer_vtag; 325 326 /* The rest of these are not from the spec, but really need to 327 * be in the cookie. 328 */ 329 330 /* My Tie Tag : Assist in discovering a restarting association. */ 331 __u32 my_ttag; 332 333 /* Peer's Tie Tag: Assist in discovering a restarting association. */ 334 __u32 peer_ttag; 335 336 /* When does this cookie expire? */ 337 struct timeval expiration; 338 339 /* Number of inbound/outbound streams which are set 340 * and negotiated during the INIT process. 341 */ 342 __u16 sinit_num_ostreams; 343 __u16 sinit_max_instreams; 344 345 /* This is the first sequence number I used. */ 346 __u32 initial_tsn; 347 348 /* This holds the originating address of the INIT packet. */ 349 union sctp_addr peer_addr; 350 351 /* IG Section 2.35.3 352 * Include the source port of the INIT-ACK 353 */ 354 __u16 my_port; 355 356 __u8 prsctp_capable; 357 358 /* Padding for future use */ 359 __u8 padding; 360 361 __u32 adaption_ind; 362 363 364 /* This is a shim for my peer's INIT packet, followed by 365 * a copy of the raw address list of the association. 366 * The length of the raw address list is saved in the 367 * raw_addr_list_len field, which will be used at the time when 368 * the association TCB is re-constructed from the cookie. 369 */ 370 __u32 raw_addr_list_len; 371 struct sctp_init_chunk peer_init[0]; 372 }; 373 374 375 /* The format of our cookie that we send to our peer. */ 376 struct sctp_signed_cookie { 377 __u8 signature[SCTP_SECRET_SIZE]; 378 struct sctp_cookie c; 379 }; 380 381 /* This is another convenience type to allocate memory for address 382 * params for the maximum size and pass such structures around 383 * internally. 384 */ 385 union sctp_addr_param { 386 struct sctp_ipv4addr_param v4; 387 struct sctp_ipv6addr_param v6; 388 }; 389 390 /* A convenience type to allow walking through the various 391 * parameters and avoid casting all over the place. 392 */ 393 union sctp_params { 394 void *v; 395 struct sctp_paramhdr *p; 396 struct sctp_cookie_preserve_param *life; 397 struct sctp_hostname_param *dns; 398 struct sctp_cookie_param *cookie; 399 struct sctp_supported_addrs_param *sat; 400 struct sctp_ipv4addr_param *v4; 401 struct sctp_ipv6addr_param *v6; 402 union sctp_addr_param *addr; 403 struct sctp_adaption_ind_param *aind; 404 }; 405 406 /* RFC 2960. Section 3.3.5 Heartbeat. 407 * Heartbeat Information: variable length 408 * The Sender-specific Heartbeat Info field should normally include 409 * information about the sender's current time when this HEARTBEAT 410 * chunk is sent and the destination transport address to which this 411 * HEARTBEAT is sent (see Section 8.3). 412 */ 413 typedef struct sctp_sender_hb_info { 414 struct sctp_paramhdr param_hdr; 415 union sctp_addr daddr; 416 unsigned long sent_at; 417 } __attribute__((packed)) sctp_sender_hb_info_t; 418 419 /* 420 * RFC 2960 1.3.2 Sequenced Delivery within Streams 421 * 422 * The term "stream" is used in SCTP to refer to a sequence of user 423 * messages that are to be delivered to the upper-layer protocol in 424 * order with respect to other messages within the same stream. This is 425 * in contrast to its usage in TCP, where it refers to a sequence of 426 * bytes (in this document a byte is assumed to be eight bits). 427 * ... 428 * 429 * This is the structure we use to track both our outbound and inbound 430 * SSN, or Stream Sequence Numbers. 431 */ 432 433 struct sctp_stream { 434 __u16 *ssn; 435 unsigned int len; 436 }; 437 438 struct sctp_ssnmap { 439 struct sctp_stream in; 440 struct sctp_stream out; 441 int malloced; 442 }; 443 444 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, int gfp); 445 void sctp_ssnmap_free(struct sctp_ssnmap *map); 446 void sctp_ssnmap_clear(struct sctp_ssnmap *map); 447 448 /* What is the current SSN number for this stream? */ 449 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id) 450 { 451 return stream->ssn[id]; 452 } 453 454 /* Return the next SSN number for this stream. */ 455 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id) 456 { 457 return stream->ssn[id]++; 458 } 459 460 /* Skip over this ssn and all below. */ 461 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, 462 __u16 ssn) 463 { 464 stream->ssn[id] = ssn+1; 465 } 466 467 /* 468 * Pointers to address related SCTP functions. 469 * (i.e. things that depend on the address family.) 470 */ 471 struct sctp_af { 472 int (*sctp_xmit) (struct sk_buff *skb, 473 struct sctp_transport *, 474 int ipfragok); 475 int (*setsockopt) (struct sock *sk, 476 int level, 477 int optname, 478 char __user *optval, 479 int optlen); 480 int (*getsockopt) (struct sock *sk, 481 int level, 482 int optname, 483 char __user *optval, 484 int __user *optlen); 485 struct dst_entry *(*get_dst) (struct sctp_association *asoc, 486 union sctp_addr *daddr, 487 union sctp_addr *saddr); 488 void (*get_saddr) (struct sctp_association *asoc, 489 struct dst_entry *dst, 490 union sctp_addr *daddr, 491 union sctp_addr *saddr); 492 void (*copy_addrlist) (struct list_head *, 493 struct net_device *); 494 void (*dst_saddr) (union sctp_addr *saddr, 495 struct dst_entry *dst, 496 unsigned short port); 497 int (*cmp_addr) (const union sctp_addr *addr1, 498 const union sctp_addr *addr2); 499 void (*addr_copy) (union sctp_addr *dst, 500 union sctp_addr *src); 501 void (*from_skb) (union sctp_addr *, 502 struct sk_buff *skb, 503 int saddr); 504 void (*from_sk) (union sctp_addr *, 505 struct sock *sk); 506 void (*to_sk_saddr) (union sctp_addr *, 507 struct sock *sk); 508 void (*to_sk_daddr) (union sctp_addr *, 509 struct sock *sk); 510 void (*from_addr_param) (union sctp_addr *, 511 union sctp_addr_param *, 512 __u16 port, int iif); 513 int (*to_addr_param) (const union sctp_addr *, 514 union sctp_addr_param *); 515 int (*addr_valid) (union sctp_addr *, 516 struct sctp_sock *); 517 sctp_scope_t (*scope) (union sctp_addr *); 518 void (*inaddr_any) (union sctp_addr *, unsigned short); 519 int (*is_any) (const union sctp_addr *); 520 int (*available) (union sctp_addr *, 521 struct sctp_sock *); 522 int (*skb_iif) (const struct sk_buff *sk); 523 int (*is_ce) (const struct sk_buff *sk); 524 void (*seq_dump_addr)(struct seq_file *seq, 525 union sctp_addr *addr); 526 __u16 net_header_len; 527 int sockaddr_len; 528 sa_family_t sa_family; 529 struct list_head list; 530 }; 531 532 struct sctp_af *sctp_get_af_specific(sa_family_t); 533 int sctp_register_af(struct sctp_af *); 534 535 /* Protocol family functions. */ 536 struct sctp_pf { 537 void (*event_msgname)(struct sctp_ulpevent *, char *, int *); 538 void (*skb_msgname) (struct sk_buff *, char *, int *); 539 int (*af_supported) (sa_family_t, struct sctp_sock *); 540 int (*cmp_addr) (const union sctp_addr *, 541 const union sctp_addr *, 542 struct sctp_sock *); 543 int (*bind_verify) (struct sctp_sock *, union sctp_addr *); 544 int (*send_verify) (struct sctp_sock *, union sctp_addr *); 545 int (*supported_addrs)(const struct sctp_sock *, __u16 *); 546 struct sock *(*create_accept_sk) (struct sock *sk, 547 struct sctp_association *asoc); 548 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *); 549 struct sctp_af *af; 550 }; 551 552 553 /* Structure to track chunk fragments that have been acked, but peer 554 * fragments of the same message have not. 555 */ 556 struct sctp_datamsg { 557 /* Chunks waiting to be submitted to lower layer. */ 558 struct list_head chunks; 559 /* Chunks that have been transmitted. */ 560 struct list_head track; 561 /* Reference counting. */ 562 atomic_t refcnt; 563 /* When is this message no longer interesting to the peer? */ 564 unsigned long expires_at; 565 /* Did the messenge fail to send? */ 566 int send_error; 567 char send_failed; 568 /* Control whether chunks from this message can be abandoned. */ 569 char can_abandon; 570 }; 571 572 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, 573 struct sctp_sndrcvinfo *, 574 struct msghdr *, int len); 575 void sctp_datamsg_put(struct sctp_datamsg *); 576 void sctp_datamsg_free(struct sctp_datamsg *); 577 void sctp_datamsg_track(struct sctp_chunk *); 578 void sctp_chunk_fail(struct sctp_chunk *, int error); 579 int sctp_chunk_abandoned(struct sctp_chunk *); 580 581 582 /* RFC2960 1.4 Key Terms 583 * 584 * o Chunk: A unit of information within an SCTP packet, consisting of 585 * a chunk header and chunk-specific content. 586 * 587 * As a matter of convenience, we remember the SCTP common header for 588 * each chunk as well as a few other header pointers... 589 */ 590 struct sctp_chunk { 591 /* These first three elements MUST PRECISELY match the first 592 * three elements of struct sk_buff. This allows us to reuse 593 * all the skb_* queue management functions. 594 */ 595 struct sctp_chunk *next; 596 struct sctp_chunk *prev; 597 struct sk_buff_head *list; 598 atomic_t refcnt; 599 600 /* This is our link to the per-transport transmitted list. */ 601 struct list_head transmitted_list; 602 603 /* This field is used by chunks that hold fragmented data. 604 * For the first fragment this is the list that holds the rest of 605 * fragments. For the remaining fragments, this is the link to the 606 * frag_list maintained in the first fragment. 607 */ 608 struct list_head frag_list; 609 610 /* This points to the sk_buff containing the actual data. */ 611 struct sk_buff *skb; 612 613 /* These are the SCTP headers by reverse order in a packet. 614 * Note that some of these may happen more than once. In that 615 * case, we point at the "current" one, whatever that means 616 * for that level of header. 617 */ 618 619 /* We point this at the FIRST TLV parameter to chunk_hdr. */ 620 union sctp_params param_hdr; 621 union { 622 __u8 *v; 623 struct sctp_datahdr *data_hdr; 624 struct sctp_inithdr *init_hdr; 625 struct sctp_sackhdr *sack_hdr; 626 struct sctp_heartbeathdr *hb_hdr; 627 struct sctp_sender_hb_info *hbs_hdr; 628 struct sctp_shutdownhdr *shutdown_hdr; 629 struct sctp_signed_cookie *cookie_hdr; 630 struct sctp_ecnehdr *ecne_hdr; 631 struct sctp_cwrhdr *ecn_cwr_hdr; 632 struct sctp_errhdr *err_hdr; 633 struct sctp_addiphdr *addip_hdr; 634 struct sctp_fwdtsn_hdr *fwdtsn_hdr; 635 } subh; 636 637 __u8 *chunk_end; 638 639 struct sctp_chunkhdr *chunk_hdr; 640 struct sctphdr *sctp_hdr; 641 642 /* This needs to be recoverable for SCTP_SEND_FAILED events. */ 643 struct sctp_sndrcvinfo sinfo; 644 645 /* Which association does this belong to? */ 646 struct sctp_association *asoc; 647 648 /* What endpoint received this chunk? */ 649 struct sctp_ep_common *rcvr; 650 651 /* We fill this in if we are calculating RTT. */ 652 unsigned long sent_at; 653 654 /* What is the origin IP address for this chunk? */ 655 union sctp_addr source; 656 /* Destination address for this chunk. */ 657 union sctp_addr dest; 658 659 /* For outbound message, track all fragments for SEND_FAILED. */ 660 struct sctp_datamsg *msg; 661 662 /* For an inbound chunk, this tells us where it came from. 663 * For an outbound chunk, it tells us where we'd like it to 664 * go. It is NULL if we have no preference. 665 */ 666 struct sctp_transport *transport; 667 668 __u8 rtt_in_progress; /* Is this chunk used for RTT calculation? */ 669 __u8 resent; /* Has this chunk ever been retransmitted. */ 670 __u8 has_tsn; /* Does this chunk have a TSN yet? */ 671 __u8 has_ssn; /* Does this chunk have a SSN yet? */ 672 __u8 singleton; /* Was this the only chunk in the packet? */ 673 __u8 end_of_packet; /* Was this the last chunk in the packet? */ 674 __u8 ecn_ce_done; /* Have we processed the ECN CE bit? */ 675 __u8 pdiscard; /* Discard the whole packet now? */ 676 __u8 tsn_gap_acked; /* Is this chunk acked by a GAP ACK? */ 677 __u8 fast_retransmit; /* Is this chunk fast retransmitted? */ 678 __u8 tsn_missing_report; /* Data chunk missing counter. */ 679 }; 680 681 void sctp_chunk_hold(struct sctp_chunk *); 682 void sctp_chunk_put(struct sctp_chunk *); 683 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 684 struct iovec *data); 685 void sctp_chunk_free(struct sctp_chunk *); 686 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); 687 struct sctp_chunk *sctp_chunkify(struct sk_buff *, 688 const struct sctp_association *, 689 struct sock *); 690 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, 691 union sctp_addr *); 692 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); 693 694 /* This is a structure for holding either an IPv6 or an IPv4 address. */ 695 /* sin_family -- AF_INET or AF_INET6 696 * sin_port -- ordinary port number 697 * sin_addr -- cast to either (struct in_addr) or (struct in6_addr) 698 */ 699 struct sctp_sockaddr_entry { 700 struct list_head list; 701 union sctp_addr a; 702 }; 703 704 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *); 705 706 /* This structure holds lists of chunks as we are assembling for 707 * transmission. 708 */ 709 struct sctp_packet { 710 /* These are the SCTP header values (host order) for the packet. */ 711 __u16 source_port; 712 __u16 destination_port; 713 __u32 vtag; 714 715 /* This contains the payload chunks. */ 716 struct sk_buff_head chunks; 717 718 /* This is the overhead of the sctp and ip headers. */ 719 size_t overhead; 720 /* This is the total size of all chunks INCLUDING padding. */ 721 size_t size; 722 723 /* The packet is destined for this transport address. 724 * The function we finally use to pass down to the next lower 725 * layer lives in the transport structure. 726 */ 727 struct sctp_transport *transport; 728 729 /* This packet contains a COOKIE-ECHO chunk. */ 730 char has_cookie_echo; 731 732 /* This packet containsa SACK chunk. */ 733 char has_sack; 734 735 /* SCTP cannot fragment this packet. So let ip fragment it. */ 736 char ipfragok; 737 738 int malloced; 739 }; 740 741 struct sctp_packet *sctp_packet_init(struct sctp_packet *, 742 struct sctp_transport *, 743 __u16 sport, __u16 dport); 744 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int); 745 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *, 746 struct sctp_chunk *); 747 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *, 748 struct sctp_chunk *); 749 int sctp_packet_transmit(struct sctp_packet *); 750 void sctp_packet_free(struct sctp_packet *); 751 752 static inline int sctp_packet_empty(struct sctp_packet *packet) 753 { 754 return (packet->size == packet->overhead); 755 } 756 757 /* This represents a remote transport address. 758 * For local transport addresses, we just use union sctp_addr. 759 * 760 * RFC2960 Section 1.4 Key Terms 761 * 762 * o Transport address: A Transport Address is traditionally defined 763 * by Network Layer address, Transport Layer protocol and Transport 764 * Layer port number. In the case of SCTP running over IP, a 765 * transport address is defined by the combination of an IP address 766 * and an SCTP port number (where SCTP is the Transport protocol). 767 * 768 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control 769 * 770 * o The sender keeps a separate congestion control parameter set for 771 * each of the destination addresses it can send to (not each 772 * source-destination pair but for each destination). The parameters 773 * should decay if the address is not used for a long enough time 774 * period. 775 * 776 */ 777 struct sctp_transport { 778 /* A list of transports. */ 779 struct list_head transports; 780 781 /* Reference counting. */ 782 atomic_t refcnt; 783 int dead; 784 785 /* This is the peer's IP address and port. */ 786 union sctp_addr ipaddr; 787 788 /* These are the functions we call to handle LLP stuff. */ 789 struct sctp_af *af_specific; 790 791 /* Which association do we belong to? */ 792 struct sctp_association *asoc; 793 794 /* RFC2960 795 * 796 * 12.3 Per Transport Address Data 797 * 798 * For each destination transport address in the peer's 799 * address list derived from the INIT or INIT ACK chunk, a 800 * number of data elements needs to be maintained including: 801 */ 802 __u32 rtt; /* This is the most recent RTT. */ 803 804 /* RTO : The current retransmission timeout value. */ 805 __u32 rto; 806 807 /* RTTVAR : The current RTT variation. */ 808 __u32 rttvar; 809 810 /* SRTT : The current smoothed round trip time. */ 811 __u32 srtt; 812 813 /* RTO-Pending : A flag used to track if one of the DATA 814 * chunks sent to this address is currently being 815 * used to compute a RTT. If this flag is 0, 816 * the next DATA chunk sent to this destination 817 * should be used to compute a RTT and this flag 818 * should be set. Every time the RTT 819 * calculation completes (i.e. the DATA chunk 820 * is SACK'd) clear this flag. 821 */ 822 int rto_pending; 823 824 /* 825 * These are the congestion stats. 826 */ 827 /* cwnd : The current congestion window. */ 828 __u32 cwnd; /* This is the actual cwnd. */ 829 830 /* ssthresh : The current slow start threshold value. */ 831 __u32 ssthresh; 832 833 /* partial : The tracking method for increase of cwnd when in 834 * bytes acked : congestion avoidance mode (see Section 6.2.2) 835 */ 836 __u32 partial_bytes_acked; 837 838 /* Data that has been sent, but not acknowledged. */ 839 __u32 flight_size; 840 841 /* PMTU : The current known path MTU. */ 842 __u32 pmtu; 843 844 /* Destination */ 845 struct dst_entry *dst; 846 /* Source address. */ 847 union sctp_addr saddr; 848 849 /* When was the last time(in jiffies) that a data packet was sent on 850 * this transport? This is used to adjust the cwnd when the transport 851 * becomes inactive. 852 */ 853 unsigned long last_time_used; 854 855 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 856 * the destination address every heartbeat interval. 857 */ 858 int hb_interval; 859 860 /* When was the last time (in jiffies) that we heard from this 861 * transport? We use this to pick new active and retran paths. 862 */ 863 unsigned long last_time_heard; 864 865 /* Last time(in jiffies) when cwnd is reduced due to the congestion 866 * indication based on ECNE chunk. 867 */ 868 unsigned long last_time_ecne_reduced; 869 870 /* The number of times INIT has been sent on this transport. */ 871 int init_sent_count; 872 873 /* state : The current state of this destination, 874 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKOWN. 875 */ 876 int state; 877 878 /* hb_allowed : The current heartbeat state of this destination, 879 * : i.e. ALLOW-HB, NO-HEARTBEAT, etc. 880 */ 881 int hb_allowed; 882 883 /* These are the error stats for this destination. */ 884 885 /* Error count : The current error count for this destination. */ 886 unsigned short error_count; 887 888 /* This is the max_retrans value for the transport and will 889 * be initialized to proto.max_retrans.path. This can be changed 890 * using SCTP_SET_PEER_ADDR_PARAMS socket option. 891 */ 892 int max_retrans; 893 894 /* Per : A timer used by each destination. 895 * Destination : 896 * Timer : 897 * 898 * [Everywhere else in the text this is called T3-rtx. -ed] 899 */ 900 struct timer_list T3_rtx_timer; 901 902 /* Heartbeat timer is per destination. */ 903 struct timer_list hb_timer; 904 905 /* Since we're using per-destination retransmission timers 906 * (see above), we're also using per-destination "transmitted" 907 * queues. This probably ought to be a private struct 908 * accessible only within the outqueue, but it's not, yet. 909 */ 910 struct list_head transmitted; 911 912 /* We build bundle-able packets for this transport here. */ 913 struct sctp_packet packet; 914 915 /* This is the list of transports that have chunks to send. */ 916 struct list_head send_ready; 917 918 int malloced; /* Is this structure kfree()able? */ 919 920 /* State information saved for SFR_CACC algorithm. The key 921 * idea in SFR_CACC is to maintain state at the sender on a 922 * per-destination basis when a changeover happens. 923 * char changeover_active; 924 * char cycling_changeover; 925 * __u32 next_tsn_at_change; 926 * char cacc_saw_newack; 927 */ 928 struct { 929 /* An unsigned integer, which stores the next TSN to be 930 * used by the sender, at the moment of changeover. 931 */ 932 __u32 next_tsn_at_change; 933 934 /* A flag which indicates the occurrence of a changeover */ 935 char changeover_active; 936 937 /* A flag which indicates whether the change of primary is 938 * the first switch to this destination address during an 939 * active switch. 940 */ 941 char cycling_changeover; 942 943 /* A temporary flag, which is used during the processing of 944 * a SACK to estimate the causative TSN(s)'s group. 945 */ 946 char cacc_saw_newack; 947 } cacc; 948 }; 949 950 struct sctp_transport *sctp_transport_new(const union sctp_addr *, int); 951 void sctp_transport_set_owner(struct sctp_transport *, 952 struct sctp_association *); 953 void sctp_transport_route(struct sctp_transport *, union sctp_addr *, 954 struct sctp_sock *); 955 void sctp_transport_pmtu(struct sctp_transport *); 956 void sctp_transport_free(struct sctp_transport *); 957 void sctp_transport_reset_timers(struct sctp_transport *); 958 void sctp_transport_hold(struct sctp_transport *); 959 void sctp_transport_put(struct sctp_transport *); 960 void sctp_transport_update_rto(struct sctp_transport *, __u32); 961 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32); 962 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t); 963 unsigned long sctp_transport_timeout(struct sctp_transport *); 964 965 966 /* This is the structure we use to queue packets as they come into 967 * SCTP. We write packets to it and read chunks from it. 968 */ 969 struct sctp_inq { 970 /* This is actually a queue of sctp_chunk each 971 * containing a partially decoded packet. 972 */ 973 struct sk_buff_head in; 974 /* This is the packet which is currently off the in queue and is 975 * being worked on through the inbound chunk processing. 976 */ 977 struct sctp_chunk *in_progress; 978 979 /* This is the delayed task to finish delivering inbound 980 * messages. 981 */ 982 struct work_struct immediate; 983 984 int malloced; /* Is this structure kfree()able? */ 985 }; 986 987 void sctp_inq_init(struct sctp_inq *); 988 void sctp_inq_free(struct sctp_inq *); 989 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet); 990 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *); 991 void sctp_inq_set_th_handler(struct sctp_inq *, void (*)(void *), void *); 992 993 /* This is the structure we use to hold outbound chunks. You push 994 * chunks in and they automatically pop out the other end as bundled 995 * packets (it calls (*output_handler)()). 996 * 997 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1, 998 * and 8.2 of the v13 draft. 999 * 1000 * It handles retransmissions. The connection to the timeout portion 1001 * of the state machine is through sctp_..._timeout() and timeout_handler. 1002 * 1003 * If you feed it SACKs, it will eat them. 1004 * 1005 * If you give it big chunks, it will fragment them. 1006 * 1007 * It assigns TSN's to data chunks. This happens at the last possible 1008 * instant before transmission. 1009 * 1010 * When free()'d, it empties itself out via output_handler(). 1011 */ 1012 struct sctp_outq { 1013 struct sctp_association *asoc; 1014 1015 /* Data pending that has never been transmitted. */ 1016 struct sk_buff_head out; 1017 1018 unsigned out_qlen; /* Total length of queued data chunks. */ 1019 1020 /* Error of send failed, may used in SCTP_SEND_FAILED event. */ 1021 unsigned error; 1022 1023 /* These are control chunks we want to send. */ 1024 struct sk_buff_head control; 1025 1026 /* These are chunks that have been sacked but are above the 1027 * CTSN, or cumulative tsn ack point. 1028 */ 1029 struct list_head sacked; 1030 1031 /* Put chunks on this list to schedule them for 1032 * retransmission. 1033 */ 1034 struct list_head retransmit; 1035 1036 /* Put chunks on this list to save them for FWD TSN processing as 1037 * they were abandoned. 1038 */ 1039 struct list_head abandoned; 1040 1041 /* How many unackd bytes do we have in-flight? */ 1042 __u32 outstanding_bytes; 1043 1044 /* Corked? */ 1045 char cork; 1046 1047 /* Is this structure empty? */ 1048 char empty; 1049 1050 /* Are we kfree()able? */ 1051 char malloced; 1052 }; 1053 1054 void sctp_outq_init(struct sctp_association *, struct sctp_outq *); 1055 void sctp_outq_teardown(struct sctp_outq *); 1056 void sctp_outq_free(struct sctp_outq*); 1057 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk); 1058 int sctp_outq_flush(struct sctp_outq *, int); 1059 int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *); 1060 int sctp_outq_is_empty(const struct sctp_outq *); 1061 void sctp_outq_restart(struct sctp_outq *); 1062 1063 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *, 1064 sctp_retransmit_reason_t); 1065 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); 1066 int sctp_outq_uncork(struct sctp_outq *); 1067 /* Uncork and flush an outqueue. */ 1068 static inline void sctp_outq_cork(struct sctp_outq *q) 1069 { 1070 q->cork = 1; 1071 } 1072 1073 /* These bind address data fields common between endpoints and associations */ 1074 struct sctp_bind_addr { 1075 1076 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1077 * 1078 * SCTP Port: The local SCTP port number the endpoint is 1079 * bound to. 1080 */ 1081 __u16 port; 1082 1083 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1084 * 1085 * Address List: The list of IP addresses that this instance 1086 * has bound. This information is passed to one's 1087 * peer(s) in INIT and INIT ACK chunks. 1088 */ 1089 struct list_head address_list; 1090 1091 int malloced; /* Are we kfree()able? */ 1092 }; 1093 1094 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port); 1095 void sctp_bind_addr_free(struct sctp_bind_addr *); 1096 int sctp_bind_addr_copy(struct sctp_bind_addr *dest, 1097 const struct sctp_bind_addr *src, 1098 sctp_scope_t scope, int gfp,int flags); 1099 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1100 int gfp); 1101 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *); 1102 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, 1103 struct sctp_sock *); 1104 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 1105 const union sctp_addr *addrs, 1106 int addrcnt, 1107 struct sctp_sock *opt); 1108 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 1109 int *addrs_len, int gfp); 1110 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, 1111 __u16 port, int gfp); 1112 1113 sctp_scope_t sctp_scope(const union sctp_addr *); 1114 int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope); 1115 int sctp_is_any(const union sctp_addr *addr); 1116 int sctp_addr_is_valid(const union sctp_addr *addr); 1117 1118 1119 /* What type of endpoint? */ 1120 typedef enum { 1121 SCTP_EP_TYPE_SOCKET, 1122 SCTP_EP_TYPE_ASSOCIATION, 1123 } sctp_endpoint_type_t; 1124 1125 /* 1126 * A common base class to bridge the implmentation view of a 1127 * socket (usually listening) endpoint versus an association's 1128 * local endpoint. 1129 * This common structure is useful for several purposes: 1130 * 1) Common interface for lookup routines. 1131 * a) Subfunctions work for either endpoint or association 1132 * b) Single interface to lookup allows hiding the lookup lock rather 1133 * than acquiring it externally. 1134 * 2) Common interface for the inbound chunk handling/state machine. 1135 * 3) Common object handling routines for reference counting, etc. 1136 * 4) Disentangle association lookup from endpoint lookup, where we 1137 * do not have to find our endpoint to find our association. 1138 * 1139 */ 1140 1141 struct sctp_ep_common { 1142 /* Fields to help us manage our entries in the hash tables. */ 1143 struct sctp_ep_common *next; 1144 struct sctp_ep_common **pprev; 1145 int hashent; 1146 1147 /* Runtime type information. What kind of endpoint is this? */ 1148 sctp_endpoint_type_t type; 1149 1150 /* Some fields to help us manage this object. 1151 * refcnt - Reference count access to this object. 1152 * dead - Do not attempt to use this object. 1153 * malloced - Do we need to kfree this object? 1154 */ 1155 atomic_t refcnt; 1156 char dead; 1157 char malloced; 1158 1159 /* What socket does this endpoint belong to? */ 1160 struct sock *sk; 1161 1162 /* This is where we receive inbound chunks. */ 1163 struct sctp_inq inqueue; 1164 1165 /* This substructure includes the defining parameters of the 1166 * endpoint: 1167 * bind_addr.port is our shared port number. 1168 * bind_addr.address_list is our set of local IP addresses. 1169 */ 1170 struct sctp_bind_addr bind_addr; 1171 1172 /* Protection during address list comparisons. */ 1173 rwlock_t addr_lock; 1174 }; 1175 1176 1177 /* RFC Section 1.4 Key Terms 1178 * 1179 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a 1180 * multi-homed host, an SCTP endpoint is represented to its peers as a 1181 * combination of a set of eligible destination transport addresses to 1182 * which SCTP packets can be sent and a set of eligible source 1183 * transport addresses from which SCTP packets can be received. 1184 * All transport addresses used by an SCTP endpoint must use the 1185 * same port number, but can use multiple IP addresses. A transport 1186 * address used by an SCTP endpoint must not be used by another 1187 * SCTP endpoint. In other words, a transport address is unique 1188 * to an SCTP endpoint. 1189 * 1190 * From an implementation perspective, each socket has one of these. 1191 * A TCP-style socket will have exactly one association on one of 1192 * these. An UDP-style socket will have multiple associations hanging 1193 * off one of these. 1194 */ 1195 1196 struct sctp_endpoint { 1197 /* Common substructure for endpoint and association. */ 1198 struct sctp_ep_common base; 1199 1200 /* Associations: A list of current associations and mappings 1201 * to the data consumers for each association. This 1202 * may be in the form of a hash table or other 1203 * implementation dependent structure. The data 1204 * consumers may be process identification 1205 * information such as file descriptors, named pipe 1206 * pointer, or table pointers dependent on how SCTP 1207 * is implemented. 1208 */ 1209 /* This is really a list of struct sctp_association entries. */ 1210 struct list_head asocs; 1211 1212 /* Secret Key: A secret key used by this endpoint to compute 1213 * the MAC. This SHOULD be a cryptographic quality 1214 * random number with a sufficient length. 1215 * Discussion in [RFC1750] can be helpful in 1216 * selection of the key. 1217 */ 1218 __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE]; 1219 int current_key; 1220 int last_key; 1221 int key_changed_at; 1222 1223 /* Default timeouts. */ 1224 int timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1225 1226 /* sendbuf acct. policy. */ 1227 __u32 sndbuf_policy; 1228 }; 1229 1230 /* Recover the outter endpoint structure. */ 1231 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) 1232 { 1233 struct sctp_endpoint *ep; 1234 1235 ep = container_of(base, struct sctp_endpoint, base); 1236 return ep; 1237 } 1238 1239 /* These are function signatures for manipulating endpoints. */ 1240 struct sctp_endpoint *sctp_endpoint_new(struct sock *, int); 1241 void sctp_endpoint_free(struct sctp_endpoint *); 1242 void sctp_endpoint_put(struct sctp_endpoint *); 1243 void sctp_endpoint_hold(struct sctp_endpoint *); 1244 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); 1245 struct sctp_association *sctp_endpoint_lookup_assoc( 1246 const struct sctp_endpoint *ep, 1247 const union sctp_addr *paddr, 1248 struct sctp_transport **); 1249 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *, 1250 const union sctp_addr *); 1251 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *, 1252 const union sctp_addr *); 1253 int sctp_has_association(const union sctp_addr *laddr, 1254 const union sctp_addr *paddr); 1255 1256 int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t, 1257 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk, 1258 struct sctp_chunk **err_chunk); 1259 int sctp_process_init(struct sctp_association *, sctp_cid_t cid, 1260 const union sctp_addr *peer, 1261 sctp_init_chunk_t *init, int gfp); 1262 __u32 sctp_generate_tag(const struct sctp_endpoint *); 1263 __u32 sctp_generate_tsn(const struct sctp_endpoint *); 1264 1265 1266 /* RFC2960 1267 * 1268 * 12. Recommended Transmission Control Block (TCB) Parameters 1269 * 1270 * This section details a recommended set of parameters that should 1271 * be contained within the TCB for an implementation. This section is 1272 * for illustrative purposes and should not be deemed as requirements 1273 * on an implementation or as an exhaustive list of all parameters 1274 * inside an SCTP TCB. Each implementation may need its own additional 1275 * parameters for optimization. 1276 */ 1277 1278 1279 /* Here we have information about each individual association. */ 1280 struct sctp_association { 1281 1282 /* A base structure common to endpoint and association. 1283 * In this context, it represents the associations's view 1284 * of the local endpoint of the association. 1285 */ 1286 struct sctp_ep_common base; 1287 1288 /* Associations on the same socket. */ 1289 struct list_head asocs; 1290 1291 /* association id. */ 1292 sctp_assoc_t assoc_id; 1293 1294 /* This is our parent endpoint. */ 1295 struct sctp_endpoint *ep; 1296 1297 /* These are those association elements needed in the cookie. */ 1298 struct sctp_cookie c; 1299 1300 /* This is all information about our peer. */ 1301 struct { 1302 /* rwnd 1303 * 1304 * Peer Rwnd : Current calculated value of the peer's rwnd. 1305 */ 1306 __u32 rwnd; 1307 1308 /* transport_addr_list 1309 * 1310 * Peer : A list of SCTP transport addresses that the 1311 * Transport : peer is bound to. This information is derived 1312 * Address : from the INIT or INIT ACK and is used to 1313 * List : associate an inbound packet with a given 1314 * : association. Normally this information is 1315 * : hashed or keyed for quick lookup and access 1316 * : of the TCB. 1317 * : The list is also initialized with the list 1318 * : of addresses passed with the sctp_connectx() 1319 * : call. 1320 * 1321 * It is a list of SCTP_transport's. 1322 */ 1323 struct list_head transport_addr_list; 1324 1325 /* transport_count 1326 * 1327 * Peer : A count of the number of peer addresses 1328 * Transport : in the Peer Transport Address List. 1329 * Address : 1330 * Count : 1331 */ 1332 __u16 transport_count; 1333 1334 /* port 1335 * The transport layer port number. 1336 */ 1337 __u16 port; 1338 1339 /* primary_path 1340 * 1341 * Primary : This is the current primary destination 1342 * Path : transport address of the peer endpoint. It 1343 * : may also specify a source transport address 1344 * : on this endpoint. 1345 * 1346 * All of these paths live on transport_addr_list. 1347 * 1348 * At the bakeoffs, we discovered that the intent of 1349 * primaryPath is that it only changes when the ULP 1350 * asks to have it changed. We add the activePath to 1351 * designate the connection we are currently using to 1352 * transmit new data and most control chunks. 1353 */ 1354 struct sctp_transport *primary_path; 1355 1356 /* Cache the primary path address here, when we 1357 * need a an address for msg_name. 1358 */ 1359 union sctp_addr primary_addr; 1360 1361 /* active_path 1362 * The path that we are currently using to 1363 * transmit new data and most control chunks. 1364 */ 1365 struct sctp_transport *active_path; 1366 1367 /* retran_path 1368 * 1369 * RFC2960 6.4 Multi-homed SCTP Endpoints 1370 * ... 1371 * Furthermore, when its peer is multi-homed, an 1372 * endpoint SHOULD try to retransmit a chunk to an 1373 * active destination transport address that is 1374 * different from the last destination address to 1375 * which the DATA chunk was sent. 1376 */ 1377 struct sctp_transport *retran_path; 1378 1379 /* Pointer to last transport I have sent on. */ 1380 struct sctp_transport *last_sent_to; 1381 1382 /* This is the last transport I have received DATA on. */ 1383 struct sctp_transport *last_data_from; 1384 1385 /* 1386 * Mapping An array of bits or bytes indicating which out of 1387 * Array order TSN's have been received (relative to the 1388 * Last Rcvd TSN). If no gaps exist, i.e. no out of 1389 * order packets have been received, this array 1390 * will be set to all zero. This structure may be 1391 * in the form of a circular buffer or bit array. 1392 * 1393 * Last Rcvd : This is the last TSN received in 1394 * TSN : sequence. This value is set initially by 1395 * : taking the peer's Initial TSN, received in 1396 * : the INIT or INIT ACK chunk, and subtracting 1397 * : one from it. 1398 * 1399 * Throughout most of the specification this is called the 1400 * "Cumulative TSN ACK Point". In this case, we 1401 * ignore the advice in 12.2 in favour of the term 1402 * used in the bulk of the text. This value is hidden 1403 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). 1404 */ 1405 struct sctp_tsnmap tsn_map; 1406 __u8 _map[sctp_tsnmap_storage_size(SCTP_TSN_MAP_SIZE)]; 1407 1408 /* Ack State : This flag indicates if the next received 1409 * : packet is to be responded to with a 1410 * : SACK. This is initializedto 0. When a packet 1411 * : is received it is incremented. If this value 1412 * : reaches 2 or more, a SACK is sent and the 1413 * : value is reset to 0. Note: This is used only 1414 * : when no DATA chunks are received out of 1415 * : order. When DATA chunks are out of order, 1416 * : SACK's are not delayed (see Section 6). 1417 */ 1418 __u8 sack_needed; /* Do we need to sack the peer? */ 1419 1420 /* These are capabilities which our peer advertised. */ 1421 __u8 ecn_capable; /* Can peer do ECN? */ 1422 __u8 ipv4_address; /* Peer understands IPv4 addresses? */ 1423 __u8 ipv6_address; /* Peer understands IPv6 addresses? */ 1424 __u8 hostname_address;/* Peer understands DNS addresses? */ 1425 __u8 asconf_capable; /* Does peer support ADDIP? */ 1426 __u8 prsctp_capable; /* Can peer do PR-SCTP? */ 1427 1428 __u32 adaption_ind; /* Adaption Code point. */ 1429 1430 /* This mask is used to disable sending the ASCONF chunk 1431 * with specified parameter to peer. 1432 */ 1433 __u16 addip_disabled_mask; 1434 1435 struct sctp_inithdr i; 1436 int cookie_len; 1437 void *cookie; 1438 1439 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1440 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the 1441 * Initial TSN Value minus 1 1442 */ 1443 __u32 addip_serial; 1444 } peer; 1445 1446 /* State : A state variable indicating what state the 1447 * : association is in, i.e. COOKIE-WAIT, 1448 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, 1449 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. 1450 * 1451 * Note: No "CLOSED" state is illustrated since if a 1452 * association is "CLOSED" its TCB SHOULD be removed. 1453 * 1454 * In this implementation we DO have a CLOSED 1455 * state which is used during initiation and shutdown. 1456 * 1457 * State takes values from SCTP_STATE_*. 1458 */ 1459 sctp_state_t state; 1460 1461 /* The cookie life I award for any cookie. */ 1462 struct timeval cookie_life; 1463 1464 /* Overall : The overall association error count. 1465 * Error Count : [Clear this any time I get something.] 1466 */ 1467 int overall_error_count; 1468 1469 /* These are the association's initial, max, and min RTO values. 1470 * These values will be initialized by system defaults, but can 1471 * be modified via the SCTP_RTOINFO socket option. 1472 */ 1473 __u32 rto_initial; 1474 __u32 rto_max; 1475 __u32 rto_min; 1476 1477 /* Maximum number of new data packets that can be sent in a burst. */ 1478 int max_burst; 1479 1480 /* This is the max_retrans value for the association. This value will 1481 * be initialized initialized from system defaults, but can be 1482 * modified by the SCTP_ASSOCINFO socket option. 1483 */ 1484 int max_retrans; 1485 1486 /* Maximum number of times the endpoint will retransmit INIT */ 1487 __u16 max_init_attempts; 1488 1489 /* How many times have we resent an INIT? */ 1490 __u16 init_retries; 1491 1492 /* The largest timeout or RTO value to use in attempting an INIT */ 1493 __u16 max_init_timeo; 1494 1495 int timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1496 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; 1497 1498 /* Transport to which SHUTDOWN chunk was last sent. */ 1499 struct sctp_transport *shutdown_last_sent_to; 1500 1501 /* Transport to which INIT chunk was last sent. */ 1502 struct sctp_transport *init_last_sent_to; 1503 1504 /* Next TSN : The next TSN number to be assigned to a new 1505 * : DATA chunk. This is sent in the INIT or INIT 1506 * : ACK chunk to the peer and incremented each 1507 * : time a DATA chunk is assigned a TSN 1508 * : (normally just prior to transmit or during 1509 * : fragmentation). 1510 */ 1511 __u32 next_tsn; 1512 1513 /* 1514 * Last Rcvd : This is the last TSN received in sequence. This value 1515 * TSN : is set initially by taking the peer's Initial TSN, 1516 * : received in the INIT or INIT ACK chunk, and 1517 * : subtracting one from it. 1518 * 1519 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. 1520 */ 1521 1522 __u32 ctsn_ack_point; 1523 1524 /* PR-SCTP Advanced.Peer.Ack.Point */ 1525 __u32 adv_peer_ack_point; 1526 1527 /* Highest TSN that is acknowledged by incoming SACKs. */ 1528 __u32 highest_sacked; 1529 1530 /* The number of unacknowledged data chunks. Reported through 1531 * the SCTP_STATUS sockopt. 1532 */ 1533 __u16 unack_data; 1534 1535 /* This is the association's receive buffer space. This value is used 1536 * to set a_rwnd field in an INIT or a SACK chunk. 1537 */ 1538 __u32 rwnd; 1539 1540 /* This is the last advertised value of rwnd over a SACK chunk. */ 1541 __u32 a_rwnd; 1542 1543 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed 1544 * to slop over a maximum of the association's frag_point. 1545 */ 1546 __u32 rwnd_over; 1547 1548 /* This is the sndbuf size in use for the association. 1549 * This corresponds to the sndbuf size for the association, 1550 * as specified in the sk->sndbuf. 1551 */ 1552 int sndbuf_used; 1553 1554 /* This is the wait queue head for send requests waiting on 1555 * the association sndbuf space. 1556 */ 1557 wait_queue_head_t wait; 1558 1559 /* Association : The smallest PMTU discovered for all of the 1560 * PMTU : peer's transport addresses. 1561 */ 1562 __u32 pmtu; 1563 1564 /* The message size at which SCTP fragmentation will occur. */ 1565 __u32 frag_point; 1566 1567 /* Counter used to count INIT errors. */ 1568 int init_err_counter; 1569 1570 /* Count the number of INIT cycles (for doubling timeout). */ 1571 int init_cycle; 1572 1573 /* Default send parameters. */ 1574 __u16 default_stream; 1575 __u16 default_flags; 1576 __u32 default_ppid; 1577 __u32 default_context; 1578 __u32 default_timetolive; 1579 1580 /* This tracks outbound ssn for a given stream. */ 1581 struct sctp_ssnmap *ssnmap; 1582 1583 /* All outbound chunks go through this structure. */ 1584 struct sctp_outq outqueue; 1585 1586 /* A smart pipe that will handle reordering and fragmentation, 1587 * as well as handle passing events up to the ULP. 1588 */ 1589 struct sctp_ulpq ulpq; 1590 1591 /* Last TSN that caused an ECNE Chunk to be sent. */ 1592 __u32 last_ecne_tsn; 1593 1594 /* Last TSN that caused a CWR Chunk to be sent. */ 1595 __u32 last_cwr_tsn; 1596 1597 /* How many duplicated TSNs have we seen? */ 1598 int numduptsns; 1599 1600 /* Number of seconds of idle time before an association is closed. */ 1601 __u32 autoclose; 1602 1603 /* These are to support 1604 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses 1605 * and Enforcement of Flow and Message Limits" 1606 * <draft-ietf-tsvwg-addip-sctp-02.txt> 1607 * or "ADDIP" for short. 1608 */ 1609 1610 1611 1612 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1613 * 1614 * R1) One and only one ASCONF Chunk MAY be in transit and 1615 * unacknowledged at any one time. If a sender, after sending 1616 * an ASCONF chunk, decides it needs to transfer another 1617 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1618 * returns from the previous ASCONF Chunk before sending a 1619 * subsequent ASCONF. Note this restriction binds each side, 1620 * so at any time two ASCONF may be in-transit on any given 1621 * association (one sent from each endpoint). 1622 * 1623 * [This is our one-and-only-one ASCONF in flight. If we do 1624 * not have an ASCONF in flight, this is NULL.] 1625 */ 1626 struct sctp_chunk *addip_last_asconf; 1627 1628 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1629 * 1630 * IMPLEMENTATION NOTE: As an optimization a receiver may wish 1631 * to save the last ASCONF-ACK for some predetermined period 1632 * of time and instead of re-processing the ASCONF (with the 1633 * same serial number) it may just re-transmit the 1634 * ASCONF-ACK. It may wish to use the arrival of a new serial 1635 * number to discard the previously saved ASCONF-ACK or any 1636 * other means it may choose to expire the saved ASCONF-ACK. 1637 * 1638 * [This is our saved ASCONF-ACK. We invalidate it when a new 1639 * ASCONF serial number arrives.] 1640 */ 1641 struct sctp_chunk *addip_last_asconf_ack; 1642 1643 /* These ASCONF chunks are waiting to be sent. 1644 * 1645 * These chunaks can't be pushed to outqueue until receiving 1646 * ASCONF_ACK for the previous ASCONF indicated by 1647 * addip_last_asconf, so as to guarantee that only one ASCONF 1648 * is in flight at any time. 1649 * 1650 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1651 * 1652 * In defining the ASCONF Chunk transfer procedures, it is 1653 * essential that these transfers MUST NOT cause congestion 1654 * within the network. To achieve this, we place these 1655 * restrictions on the transfer of ASCONF Chunks: 1656 * 1657 * R1) One and only one ASCONF Chunk MAY be in transit and 1658 * unacknowledged at any one time. If a sender, after sending 1659 * an ASCONF chunk, decides it needs to transfer another 1660 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1661 * returns from the previous ASCONF Chunk before sending a 1662 * subsequent ASCONF. Note this restriction binds each side, 1663 * so at any time two ASCONF may be in-transit on any given 1664 * association (one sent from each endpoint). 1665 * 1666 * 1667 * [I really think this is EXACTLY the sort of intelligence 1668 * which already resides in sctp_outq. Please move this 1669 * queue and its supporting logic down there. --piggy] 1670 */ 1671 struct sk_buff_head addip_chunks; 1672 1673 /* ADDIP Section 4.1 ASCONF Chunk Procedures 1674 * 1675 * A2) A serial number should be assigned to the Chunk. The 1676 * serial number SHOULD be a monotonically increasing 1677 * number. The serial number SHOULD be initialized at 1678 * the start of the association to the same value as the 1679 * Initial TSN and every time a new ASCONF chunk is created 1680 * it is incremented by one after assigning the serial number 1681 * to the newly created chunk. 1682 * 1683 * ADDIP 1684 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) 1685 * 1686 * Serial Number : 32 bits (unsigned integer) 1687 * 1688 * This value represents a Serial Number for the ASCONF 1689 * Chunk. The valid range of Serial Number is from 0 to 1690 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 1691 * after reaching 4294967295. 1692 */ 1693 __u32 addip_serial; 1694 1695 /* Need to send an ECNE Chunk? */ 1696 char need_ecne; 1697 1698 /* Is it a temporary association? */ 1699 char temp; 1700 }; 1701 1702 1703 /* An eyecatcher for determining if we are really looking at an 1704 * association data structure. 1705 */ 1706 enum { 1707 SCTP_ASSOC_EYECATCHER = 0xa550c123, 1708 }; 1709 1710 /* Recover the outter association structure. */ 1711 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) 1712 { 1713 struct sctp_association *asoc; 1714 1715 asoc = container_of(base, struct sctp_association, base); 1716 return asoc; 1717 } 1718 1719 /* These are function signatures for manipulating associations. */ 1720 1721 1722 struct sctp_association * 1723 sctp_association_new(const struct sctp_endpoint *, const struct sock *, 1724 sctp_scope_t scope, int gfp); 1725 void sctp_association_free(struct sctp_association *); 1726 void sctp_association_put(struct sctp_association *); 1727 void sctp_association_hold(struct sctp_association *); 1728 1729 struct sctp_transport *sctp_assoc_choose_init_transport( 1730 struct sctp_association *); 1731 struct sctp_transport *sctp_assoc_choose_shutdown_transport( 1732 struct sctp_association *); 1733 void sctp_assoc_update_retran_path(struct sctp_association *); 1734 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, 1735 const union sctp_addr *); 1736 int sctp_assoc_lookup_laddr(struct sctp_association *asoc, 1737 const union sctp_addr *laddr); 1738 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, 1739 const union sctp_addr *address, 1740 const int gfp, 1741 const int peer_state); 1742 void sctp_assoc_del_peer(struct sctp_association *asoc, 1743 const union sctp_addr *addr); 1744 void sctp_assoc_rm_peer(struct sctp_association *asoc, 1745 struct sctp_transport *peer); 1746 void sctp_assoc_control_transport(struct sctp_association *, 1747 struct sctp_transport *, 1748 sctp_transport_cmd_t, sctp_sn_error_t); 1749 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); 1750 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *, 1751 const union sctp_addr *, 1752 const union sctp_addr *); 1753 void sctp_assoc_migrate(struct sctp_association *, struct sock *); 1754 void sctp_assoc_update(struct sctp_association *old, 1755 struct sctp_association *new); 1756 1757 __u32 sctp_association_get_next_tsn(struct sctp_association *); 1758 1759 void sctp_assoc_sync_pmtu(struct sctp_association *); 1760 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned); 1761 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned); 1762 void sctp_assoc_set_primary(struct sctp_association *, 1763 struct sctp_transport *); 1764 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *, int); 1765 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, 1766 struct sctp_cookie*, int gfp); 1767 1768 int sctp_cmp_addr_exact(const union sctp_addr *ss1, 1769 const union sctp_addr *ss2); 1770 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); 1771 1772 /* A convenience structure to parse out SCTP specific CMSGs. */ 1773 typedef struct sctp_cmsgs { 1774 struct sctp_initmsg *init; 1775 struct sctp_sndrcvinfo *info; 1776 } sctp_cmsgs_t; 1777 1778 /* Structure for tracking memory objects */ 1779 typedef struct { 1780 char *label; 1781 atomic_t *counter; 1782 } sctp_dbg_objcnt_entry_t; 1783 1784 #endif /* __sctp_structs_h__ */ 1785