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 /* 165 * Policy for preforming sctp/socket accounting 166 * 0 - do socket level accounting, all assocs share sk_rcvbuf 167 * 1 - do sctp accounting, each asoc may use sk_rcvbuf bytes 168 */ 169 int rcvbuf_policy; 170 171 /* Delayed SACK timeout 200ms default*/ 172 int sack_timeout; 173 174 /* HB.interval - 30 seconds */ 175 int hb_interval; 176 177 /* The following variables are implementation specific. */ 178 179 /* Default initialization values to be applied to new associations. */ 180 __u16 max_instreams; 181 __u16 max_outstreams; 182 183 /* This is a list of groups of functions for each address 184 * family that we support. 185 */ 186 struct list_head address_families; 187 188 /* This is the hash of all endpoints. */ 189 int ep_hashsize; 190 struct sctp_hashbucket *ep_hashtable; 191 192 /* This is the hash of all associations. */ 193 int assoc_hashsize; 194 struct sctp_hashbucket *assoc_hashtable; 195 196 /* This is the sctp port control hash. */ 197 int port_hashsize; 198 int port_rover; 199 spinlock_t port_alloc_lock; /* Protects port_rover. */ 200 struct sctp_bind_hashbucket *port_hashtable; 201 202 /* This is the global local address list. 203 * We actively maintain this complete list of interfaces on 204 * the system by catching routing events. 205 * 206 * It is a list of sctp_sockaddr_entry. 207 */ 208 struct list_head local_addr_list; 209 spinlock_t local_addr_lock; 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_local_addr_lock (sctp_globals.local_addr_lock) 246 #define sctp_addip_enable (sctp_globals.addip_enable) 247 #define sctp_prsctp_enable (sctp_globals.prsctp_enable) 248 249 /* SCTP Socket type: UDP or TCP style. */ 250 typedef enum { 251 SCTP_SOCKET_UDP = 0, 252 SCTP_SOCKET_UDP_HIGH_BANDWIDTH, 253 SCTP_SOCKET_TCP 254 } sctp_socket_type_t; 255 256 /* Per socket SCTP information. */ 257 struct sctp_sock { 258 /* inet_sock has to be the first member of sctp_sock */ 259 struct inet_sock inet; 260 /* What kind of a socket is this? */ 261 sctp_socket_type_t type; 262 263 /* PF_ family specific functions. */ 264 struct sctp_pf *pf; 265 266 /* Access to HMAC transform. */ 267 struct crypto_tfm *hmac; 268 269 /* What is our base endpointer? */ 270 struct sctp_endpoint *ep; 271 272 struct sctp_bind_bucket *bind_hash; 273 /* Various Socket Options. */ 274 __u16 default_stream; 275 __u32 default_ppid; 276 __u16 default_flags; 277 __u32 default_context; 278 __u32 default_timetolive; 279 280 struct sctp_initmsg initmsg; 281 struct sctp_rtoinfo rtoinfo; 282 struct sctp_paddrparams paddrparam; 283 struct sctp_event_subscribe subscribe; 284 struct sctp_assocparams assocparams; 285 int user_frag; 286 __u32 autoclose; 287 __u8 nodelay; 288 __u8 disable_fragments; 289 __u8 pd_mode; 290 __u8 v4mapped; 291 __u32 adaption_ind; 292 293 /* Receive to here while partial delivery is in effect. */ 294 struct sk_buff_head pd_lobby; 295 }; 296 297 static inline struct sctp_sock *sctp_sk(const struct sock *sk) 298 { 299 return (struct sctp_sock *)sk; 300 } 301 302 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp) 303 { 304 return (struct sock *)sp; 305 } 306 307 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 308 struct sctp6_sock { 309 struct sctp_sock sctp; 310 struct ipv6_pinfo inet6; 311 }; 312 #endif /* CONFIG_IPV6 */ 313 314 315 /* This is our APPLICATION-SPECIFIC state cookie. 316 * THIS IS NOT DICTATED BY THE SPECIFICATION. 317 */ 318 /* These are the parts of an association which we send in the cookie. 319 * Most of these are straight out of: 320 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB) 321 * 322 */ 323 324 struct sctp_cookie { 325 326 /* My : Tag expected in every inbound packet and sent 327 * Verification: in the INIT or INIT ACK chunk. 328 * Tag : 329 */ 330 __u32 my_vtag; 331 332 /* Peer's : Tag expected in every outbound packet except 333 * Verification: in the INIT chunk. 334 * Tag : 335 */ 336 __u32 peer_vtag; 337 338 /* The rest of these are not from the spec, but really need to 339 * be in the cookie. 340 */ 341 342 /* My Tie Tag : Assist in discovering a restarting association. */ 343 __u32 my_ttag; 344 345 /* Peer's Tie Tag: Assist in discovering a restarting association. */ 346 __u32 peer_ttag; 347 348 /* When does this cookie expire? */ 349 struct timeval expiration; 350 351 /* Number of inbound/outbound streams which are set 352 * and negotiated during the INIT process. 353 */ 354 __u16 sinit_num_ostreams; 355 __u16 sinit_max_instreams; 356 357 /* This is the first sequence number I used. */ 358 __u32 initial_tsn; 359 360 /* This holds the originating address of the INIT packet. */ 361 union sctp_addr peer_addr; 362 363 /* IG Section 2.35.3 364 * Include the source port of the INIT-ACK 365 */ 366 __u16 my_port; 367 368 __u8 prsctp_capable; 369 370 /* Padding for future use */ 371 __u8 padding; 372 373 __u32 adaption_ind; 374 375 376 /* This is a shim for my peer's INIT packet, followed by 377 * a copy of the raw address list of the association. 378 * The length of the raw address list is saved in the 379 * raw_addr_list_len field, which will be used at the time when 380 * the association TCB is re-constructed from the cookie. 381 */ 382 __u32 raw_addr_list_len; 383 struct sctp_init_chunk peer_init[0]; 384 }; 385 386 387 /* The format of our cookie that we send to our peer. */ 388 struct sctp_signed_cookie { 389 __u8 signature[SCTP_SECRET_SIZE]; 390 struct sctp_cookie c; 391 }; 392 393 /* This is another convenience type to allocate memory for address 394 * params for the maximum size and pass such structures around 395 * internally. 396 */ 397 union sctp_addr_param { 398 struct sctp_ipv4addr_param v4; 399 struct sctp_ipv6addr_param v6; 400 }; 401 402 /* A convenience type to allow walking through the various 403 * parameters and avoid casting all over the place. 404 */ 405 union sctp_params { 406 void *v; 407 struct sctp_paramhdr *p; 408 struct sctp_cookie_preserve_param *life; 409 struct sctp_hostname_param *dns; 410 struct sctp_cookie_param *cookie; 411 struct sctp_supported_addrs_param *sat; 412 struct sctp_ipv4addr_param *v4; 413 struct sctp_ipv6addr_param *v6; 414 union sctp_addr_param *addr; 415 struct sctp_adaption_ind_param *aind; 416 }; 417 418 /* RFC 2960. Section 3.3.5 Heartbeat. 419 * Heartbeat Information: variable length 420 * The Sender-specific Heartbeat Info field should normally include 421 * information about the sender's current time when this HEARTBEAT 422 * chunk is sent and the destination transport address to which this 423 * HEARTBEAT is sent (see Section 8.3). 424 */ 425 typedef struct sctp_sender_hb_info { 426 struct sctp_paramhdr param_hdr; 427 union sctp_addr daddr; 428 unsigned long sent_at; 429 } __attribute__((packed)) sctp_sender_hb_info_t; 430 431 /* 432 * RFC 2960 1.3.2 Sequenced Delivery within Streams 433 * 434 * The term "stream" is used in SCTP to refer to a sequence of user 435 * messages that are to be delivered to the upper-layer protocol in 436 * order with respect to other messages within the same stream. This is 437 * in contrast to its usage in TCP, where it refers to a sequence of 438 * bytes (in this document a byte is assumed to be eight bits). 439 * ... 440 * 441 * This is the structure we use to track both our outbound and inbound 442 * SSN, or Stream Sequence Numbers. 443 */ 444 445 struct sctp_stream { 446 __u16 *ssn; 447 unsigned int len; 448 }; 449 450 struct sctp_ssnmap { 451 struct sctp_stream in; 452 struct sctp_stream out; 453 int malloced; 454 }; 455 456 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, 457 gfp_t gfp); 458 void sctp_ssnmap_free(struct sctp_ssnmap *map); 459 void sctp_ssnmap_clear(struct sctp_ssnmap *map); 460 461 /* What is the current SSN number for this stream? */ 462 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id) 463 { 464 return stream->ssn[id]; 465 } 466 467 /* Return the next SSN number for this stream. */ 468 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id) 469 { 470 return stream->ssn[id]++; 471 } 472 473 /* Skip over this ssn and all below. */ 474 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, 475 __u16 ssn) 476 { 477 stream->ssn[id] = ssn+1; 478 } 479 480 /* 481 * Pointers to address related SCTP functions. 482 * (i.e. things that depend on the address family.) 483 */ 484 struct sctp_af { 485 int (*sctp_xmit) (struct sk_buff *skb, 486 struct sctp_transport *, 487 int ipfragok); 488 int (*setsockopt) (struct sock *sk, 489 int level, 490 int optname, 491 char __user *optval, 492 int optlen); 493 int (*getsockopt) (struct sock *sk, 494 int level, 495 int optname, 496 char __user *optval, 497 int __user *optlen); 498 struct dst_entry *(*get_dst) (struct sctp_association *asoc, 499 union sctp_addr *daddr, 500 union sctp_addr *saddr); 501 void (*get_saddr) (struct sctp_association *asoc, 502 struct dst_entry *dst, 503 union sctp_addr *daddr, 504 union sctp_addr *saddr); 505 void (*copy_addrlist) (struct list_head *, 506 struct net_device *); 507 void (*dst_saddr) (union sctp_addr *saddr, 508 struct dst_entry *dst, 509 unsigned short port); 510 int (*cmp_addr) (const union sctp_addr *addr1, 511 const union sctp_addr *addr2); 512 void (*addr_copy) (union sctp_addr *dst, 513 union sctp_addr *src); 514 void (*from_skb) (union sctp_addr *, 515 struct sk_buff *skb, 516 int saddr); 517 void (*from_sk) (union sctp_addr *, 518 struct sock *sk); 519 void (*to_sk_saddr) (union sctp_addr *, 520 struct sock *sk); 521 void (*to_sk_daddr) (union sctp_addr *, 522 struct sock *sk); 523 void (*from_addr_param) (union sctp_addr *, 524 union sctp_addr_param *, 525 __u16 port, int iif); 526 int (*to_addr_param) (const union sctp_addr *, 527 union sctp_addr_param *); 528 int (*addr_valid) (union sctp_addr *, 529 struct sctp_sock *); 530 sctp_scope_t (*scope) (union sctp_addr *); 531 void (*inaddr_any) (union sctp_addr *, unsigned short); 532 int (*is_any) (const union sctp_addr *); 533 int (*available) (union sctp_addr *, 534 struct sctp_sock *); 535 int (*skb_iif) (const struct sk_buff *sk); 536 int (*is_ce) (const struct sk_buff *sk); 537 void (*seq_dump_addr)(struct seq_file *seq, 538 union sctp_addr *addr); 539 __u16 net_header_len; 540 int sockaddr_len; 541 sa_family_t sa_family; 542 struct list_head list; 543 }; 544 545 struct sctp_af *sctp_get_af_specific(sa_family_t); 546 int sctp_register_af(struct sctp_af *); 547 548 /* Protocol family functions. */ 549 struct sctp_pf { 550 void (*event_msgname)(struct sctp_ulpevent *, char *, int *); 551 void (*skb_msgname) (struct sk_buff *, char *, int *); 552 int (*af_supported) (sa_family_t, struct sctp_sock *); 553 int (*cmp_addr) (const union sctp_addr *, 554 const union sctp_addr *, 555 struct sctp_sock *); 556 int (*bind_verify) (struct sctp_sock *, union sctp_addr *); 557 int (*send_verify) (struct sctp_sock *, union sctp_addr *); 558 int (*supported_addrs)(const struct sctp_sock *, __u16 *); 559 struct sock *(*create_accept_sk) (struct sock *sk, 560 struct sctp_association *asoc); 561 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *); 562 struct sctp_af *af; 563 }; 564 565 566 /* Structure to track chunk fragments that have been acked, but peer 567 * fragments of the same message have not. 568 */ 569 struct sctp_datamsg { 570 /* Chunks waiting to be submitted to lower layer. */ 571 struct list_head chunks; 572 /* Chunks that have been transmitted. */ 573 struct list_head track; 574 /* Reference counting. */ 575 atomic_t refcnt; 576 /* When is this message no longer interesting to the peer? */ 577 unsigned long expires_at; 578 /* Did the messenge fail to send? */ 579 int send_error; 580 char send_failed; 581 /* Control whether chunks from this message can be abandoned. */ 582 char can_abandon; 583 }; 584 585 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, 586 struct sctp_sndrcvinfo *, 587 struct msghdr *, int len); 588 void sctp_datamsg_put(struct sctp_datamsg *); 589 void sctp_datamsg_free(struct sctp_datamsg *); 590 void sctp_datamsg_track(struct sctp_chunk *); 591 void sctp_chunk_fail(struct sctp_chunk *, int error); 592 int sctp_chunk_abandoned(struct sctp_chunk *); 593 594 /* RFC2960 1.4 Key Terms 595 * 596 * o Chunk: A unit of information within an SCTP packet, consisting of 597 * a chunk header and chunk-specific content. 598 * 599 * As a matter of convenience, we remember the SCTP common header for 600 * each chunk as well as a few other header pointers... 601 */ 602 struct sctp_chunk { 603 struct list_head list; 604 605 atomic_t refcnt; 606 607 /* This is our link to the per-transport transmitted list. */ 608 struct list_head transmitted_list; 609 610 /* This field is used by chunks that hold fragmented data. 611 * For the first fragment this is the list that holds the rest of 612 * fragments. For the remaining fragments, this is the link to the 613 * frag_list maintained in the first fragment. 614 */ 615 struct list_head frag_list; 616 617 /* This points to the sk_buff containing the actual data. */ 618 struct sk_buff *skb; 619 620 /* These are the SCTP headers by reverse order in a packet. 621 * Note that some of these may happen more than once. In that 622 * case, we point at the "current" one, whatever that means 623 * for that level of header. 624 */ 625 626 /* We point this at the FIRST TLV parameter to chunk_hdr. */ 627 union sctp_params param_hdr; 628 union { 629 __u8 *v; 630 struct sctp_datahdr *data_hdr; 631 struct sctp_inithdr *init_hdr; 632 struct sctp_sackhdr *sack_hdr; 633 struct sctp_heartbeathdr *hb_hdr; 634 struct sctp_sender_hb_info *hbs_hdr; 635 struct sctp_shutdownhdr *shutdown_hdr; 636 struct sctp_signed_cookie *cookie_hdr; 637 struct sctp_ecnehdr *ecne_hdr; 638 struct sctp_cwrhdr *ecn_cwr_hdr; 639 struct sctp_errhdr *err_hdr; 640 struct sctp_addiphdr *addip_hdr; 641 struct sctp_fwdtsn_hdr *fwdtsn_hdr; 642 } subh; 643 644 __u8 *chunk_end; 645 646 struct sctp_chunkhdr *chunk_hdr; 647 struct sctphdr *sctp_hdr; 648 649 /* This needs to be recoverable for SCTP_SEND_FAILED events. */ 650 struct sctp_sndrcvinfo sinfo; 651 652 /* Which association does this belong to? */ 653 struct sctp_association *asoc; 654 655 /* What endpoint received this chunk? */ 656 struct sctp_ep_common *rcvr; 657 658 /* We fill this in if we are calculating RTT. */ 659 unsigned long sent_at; 660 661 /* What is the origin IP address for this chunk? */ 662 union sctp_addr source; 663 /* Destination address for this chunk. */ 664 union sctp_addr dest; 665 666 /* For outbound message, track all fragments for SEND_FAILED. */ 667 struct sctp_datamsg *msg; 668 669 /* For an inbound chunk, this tells us where it came from. 670 * For an outbound chunk, it tells us where we'd like it to 671 * go. It is NULL if we have no preference. 672 */ 673 struct sctp_transport *transport; 674 675 __u8 rtt_in_progress; /* Is this chunk used for RTT calculation? */ 676 __u8 resent; /* Has this chunk ever been retransmitted. */ 677 __u8 has_tsn; /* Does this chunk have a TSN yet? */ 678 __u8 has_ssn; /* Does this chunk have a SSN yet? */ 679 __u8 singleton; /* Was this the only chunk in the packet? */ 680 __u8 end_of_packet; /* Was this the last chunk in the packet? */ 681 __u8 ecn_ce_done; /* Have we processed the ECN CE bit? */ 682 __u8 pdiscard; /* Discard the whole packet now? */ 683 __u8 tsn_gap_acked; /* Is this chunk acked by a GAP ACK? */ 684 __u8 fast_retransmit; /* Is this chunk fast retransmitted? */ 685 __u8 tsn_missing_report; /* Data chunk missing counter. */ 686 }; 687 688 void sctp_chunk_hold(struct sctp_chunk *); 689 void sctp_chunk_put(struct sctp_chunk *); 690 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 691 struct iovec *data); 692 void sctp_chunk_free(struct sctp_chunk *); 693 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); 694 struct sctp_chunk *sctp_chunkify(struct sk_buff *, 695 const struct sctp_association *, 696 struct sock *); 697 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, 698 union sctp_addr *); 699 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); 700 701 /* This is a structure for holding either an IPv6 or an IPv4 address. */ 702 /* sin_family -- AF_INET or AF_INET6 703 * sin_port -- ordinary port number 704 * sin_addr -- cast to either (struct in_addr) or (struct in6_addr) 705 */ 706 struct sctp_sockaddr_entry { 707 struct list_head list; 708 union sctp_addr a; 709 }; 710 711 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *); 712 713 /* This structure holds lists of chunks as we are assembling for 714 * transmission. 715 */ 716 struct sctp_packet { 717 /* These are the SCTP header values (host order) for the packet. */ 718 __u16 source_port; 719 __u16 destination_port; 720 __u32 vtag; 721 722 /* This contains the payload chunks. */ 723 struct list_head chunk_list; 724 725 /* This is the overhead of the sctp and ip headers. */ 726 size_t overhead; 727 /* This is the total size of all chunks INCLUDING padding. */ 728 size_t size; 729 730 /* The packet is destined for this transport address. 731 * The function we finally use to pass down to the next lower 732 * layer lives in the transport structure. 733 */ 734 struct sctp_transport *transport; 735 736 /* This packet contains a COOKIE-ECHO chunk. */ 737 char has_cookie_echo; 738 739 /* This packet containsa SACK chunk. */ 740 char has_sack; 741 742 /* SCTP cannot fragment this packet. So let ip fragment it. */ 743 char ipfragok; 744 745 int malloced; 746 }; 747 748 struct sctp_packet *sctp_packet_init(struct sctp_packet *, 749 struct sctp_transport *, 750 __u16 sport, __u16 dport); 751 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int); 752 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *, 753 struct sctp_chunk *); 754 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *, 755 struct sctp_chunk *); 756 int sctp_packet_transmit(struct sctp_packet *); 757 void sctp_packet_free(struct sctp_packet *); 758 759 static inline int sctp_packet_empty(struct sctp_packet *packet) 760 { 761 return (packet->size == packet->overhead); 762 } 763 764 /* This represents a remote transport address. 765 * For local transport addresses, we just use union sctp_addr. 766 * 767 * RFC2960 Section 1.4 Key Terms 768 * 769 * o Transport address: A Transport Address is traditionally defined 770 * by Network Layer address, Transport Layer protocol and Transport 771 * Layer port number. In the case of SCTP running over IP, a 772 * transport address is defined by the combination of an IP address 773 * and an SCTP port number (where SCTP is the Transport protocol). 774 * 775 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control 776 * 777 * o The sender keeps a separate congestion control parameter set for 778 * each of the destination addresses it can send to (not each 779 * source-destination pair but for each destination). The parameters 780 * should decay if the address is not used for a long enough time 781 * period. 782 * 783 */ 784 struct sctp_transport { 785 /* A list of transports. */ 786 struct list_head transports; 787 788 /* Reference counting. */ 789 atomic_t refcnt; 790 int dead; 791 792 /* This is the peer's IP address and port. */ 793 union sctp_addr ipaddr; 794 795 /* These are the functions we call to handle LLP stuff. */ 796 struct sctp_af *af_specific; 797 798 /* Which association do we belong to? */ 799 struct sctp_association *asoc; 800 801 /* RFC2960 802 * 803 * 12.3 Per Transport Address Data 804 * 805 * For each destination transport address in the peer's 806 * address list derived from the INIT or INIT ACK chunk, a 807 * number of data elements needs to be maintained including: 808 */ 809 __u32 rtt; /* This is the most recent RTT. */ 810 811 /* RTO : The current retransmission timeout value. */ 812 __u32 rto; 813 814 /* RTTVAR : The current RTT variation. */ 815 __u32 rttvar; 816 817 /* SRTT : The current smoothed round trip time. */ 818 __u32 srtt; 819 820 /* RTO-Pending : A flag used to track if one of the DATA 821 * chunks sent to this address is currently being 822 * used to compute a RTT. If this flag is 0, 823 * the next DATA chunk sent to this destination 824 * should be used to compute a RTT and this flag 825 * should be set. Every time the RTT 826 * calculation completes (i.e. the DATA chunk 827 * is SACK'd) clear this flag. 828 */ 829 int rto_pending; 830 831 /* 832 * These are the congestion stats. 833 */ 834 /* cwnd : The current congestion window. */ 835 __u32 cwnd; /* This is the actual cwnd. */ 836 837 /* ssthresh : The current slow start threshold value. */ 838 __u32 ssthresh; 839 840 /* partial : The tracking method for increase of cwnd when in 841 * bytes acked : congestion avoidance mode (see Section 6.2.2) 842 */ 843 __u32 partial_bytes_acked; 844 845 /* Data that has been sent, but not acknowledged. */ 846 __u32 flight_size; 847 848 /* PMTU : The current known path MTU. */ 849 __u32 pmtu; 850 851 /* Destination */ 852 struct dst_entry *dst; 853 /* Source address. */ 854 union sctp_addr saddr; 855 856 /* When was the last time(in jiffies) that a data packet was sent on 857 * this transport? This is used to adjust the cwnd when the transport 858 * becomes inactive. 859 */ 860 unsigned long last_time_used; 861 862 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 863 * the destination address every heartbeat interval. 864 */ 865 int hb_interval; 866 867 /* When was the last time (in jiffies) that we heard from this 868 * transport? We use this to pick new active and retran paths. 869 */ 870 unsigned long last_time_heard; 871 872 /* Last time(in jiffies) when cwnd is reduced due to the congestion 873 * indication based on ECNE chunk. 874 */ 875 unsigned long last_time_ecne_reduced; 876 877 /* The number of times INIT has been sent on this transport. */ 878 int init_sent_count; 879 880 /* state : The current state of this destination, 881 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKOWN. 882 */ 883 int state; 884 885 /* hb_allowed : The current heartbeat state of this destination, 886 * : i.e. ALLOW-HB, NO-HEARTBEAT, etc. 887 */ 888 int hb_allowed; 889 890 /* These are the error stats for this destination. */ 891 892 /* Error count : The current error count for this destination. */ 893 unsigned short error_count; 894 895 /* This is the max_retrans value for the transport and will 896 * be initialized to proto.max_retrans.path. This can be changed 897 * using SCTP_SET_PEER_ADDR_PARAMS socket option. 898 */ 899 int max_retrans; 900 901 /* Per : A timer used by each destination. 902 * Destination : 903 * Timer : 904 * 905 * [Everywhere else in the text this is called T3-rtx. -ed] 906 */ 907 struct timer_list T3_rtx_timer; 908 909 /* Heartbeat timer is per destination. */ 910 struct timer_list hb_timer; 911 912 /* Since we're using per-destination retransmission timers 913 * (see above), we're also using per-destination "transmitted" 914 * queues. This probably ought to be a private struct 915 * accessible only within the outqueue, but it's not, yet. 916 */ 917 struct list_head transmitted; 918 919 /* We build bundle-able packets for this transport here. */ 920 struct sctp_packet packet; 921 922 /* This is the list of transports that have chunks to send. */ 923 struct list_head send_ready; 924 925 int malloced; /* Is this structure kfree()able? */ 926 927 /* State information saved for SFR_CACC algorithm. The key 928 * idea in SFR_CACC is to maintain state at the sender on a 929 * per-destination basis when a changeover happens. 930 * char changeover_active; 931 * char cycling_changeover; 932 * __u32 next_tsn_at_change; 933 * char cacc_saw_newack; 934 */ 935 struct { 936 /* An unsigned integer, which stores the next TSN to be 937 * used by the sender, at the moment of changeover. 938 */ 939 __u32 next_tsn_at_change; 940 941 /* A flag which indicates the occurrence of a changeover */ 942 char changeover_active; 943 944 /* A flag which indicates whether the change of primary is 945 * the first switch to this destination address during an 946 * active switch. 947 */ 948 char cycling_changeover; 949 950 /* A temporary flag, which is used during the processing of 951 * a SACK to estimate the causative TSN(s)'s group. 952 */ 953 char cacc_saw_newack; 954 } cacc; 955 }; 956 957 struct sctp_transport *sctp_transport_new(const union sctp_addr *, 958 gfp_t); 959 void sctp_transport_set_owner(struct sctp_transport *, 960 struct sctp_association *); 961 void sctp_transport_route(struct sctp_transport *, union sctp_addr *, 962 struct sctp_sock *); 963 void sctp_transport_pmtu(struct sctp_transport *); 964 void sctp_transport_free(struct sctp_transport *); 965 void sctp_transport_reset_timers(struct sctp_transport *); 966 void sctp_transport_hold(struct sctp_transport *); 967 void sctp_transport_put(struct sctp_transport *); 968 void sctp_transport_update_rto(struct sctp_transport *, __u32); 969 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32); 970 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t); 971 unsigned long sctp_transport_timeout(struct sctp_transport *); 972 973 974 /* This is the structure we use to queue packets as they come into 975 * SCTP. We write packets to it and read chunks from it. 976 */ 977 struct sctp_inq { 978 /* This is actually a queue of sctp_chunk each 979 * containing a partially decoded packet. 980 */ 981 struct list_head in_chunk_list; 982 /* This is the packet which is currently off the in queue and is 983 * being worked on through the inbound chunk processing. 984 */ 985 struct sctp_chunk *in_progress; 986 987 /* This is the delayed task to finish delivering inbound 988 * messages. 989 */ 990 struct work_struct immediate; 991 992 int malloced; /* Is this structure kfree()able? */ 993 }; 994 995 void sctp_inq_init(struct sctp_inq *); 996 void sctp_inq_free(struct sctp_inq *); 997 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet); 998 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *); 999 void sctp_inq_set_th_handler(struct sctp_inq *, void (*)(void *), void *); 1000 1001 /* This is the structure we use to hold outbound chunks. You push 1002 * chunks in and they automatically pop out the other end as bundled 1003 * packets (it calls (*output_handler)()). 1004 * 1005 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1, 1006 * and 8.2 of the v13 draft. 1007 * 1008 * It handles retransmissions. The connection to the timeout portion 1009 * of the state machine is through sctp_..._timeout() and timeout_handler. 1010 * 1011 * If you feed it SACKs, it will eat them. 1012 * 1013 * If you give it big chunks, it will fragment them. 1014 * 1015 * It assigns TSN's to data chunks. This happens at the last possible 1016 * instant before transmission. 1017 * 1018 * When free()'d, it empties itself out via output_handler(). 1019 */ 1020 struct sctp_outq { 1021 struct sctp_association *asoc; 1022 1023 /* Data pending that has never been transmitted. */ 1024 struct list_head out_chunk_list; 1025 1026 unsigned out_qlen; /* Total length of queued data chunks. */ 1027 1028 /* Error of send failed, may used in SCTP_SEND_FAILED event. */ 1029 unsigned error; 1030 1031 /* These are control chunks we want to send. */ 1032 struct list_head control_chunk_list; 1033 1034 /* These are chunks that have been sacked but are above the 1035 * CTSN, or cumulative tsn ack point. 1036 */ 1037 struct list_head sacked; 1038 1039 /* Put chunks on this list to schedule them for 1040 * retransmission. 1041 */ 1042 struct list_head retransmit; 1043 1044 /* Put chunks on this list to save them for FWD TSN processing as 1045 * they were abandoned. 1046 */ 1047 struct list_head abandoned; 1048 1049 /* How many unackd bytes do we have in-flight? */ 1050 __u32 outstanding_bytes; 1051 1052 /* Corked? */ 1053 char cork; 1054 1055 /* Is this structure empty? */ 1056 char empty; 1057 1058 /* Are we kfree()able? */ 1059 char malloced; 1060 }; 1061 1062 void sctp_outq_init(struct sctp_association *, struct sctp_outq *); 1063 void sctp_outq_teardown(struct sctp_outq *); 1064 void sctp_outq_free(struct sctp_outq*); 1065 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk); 1066 int sctp_outq_flush(struct sctp_outq *, int); 1067 int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *); 1068 int sctp_outq_is_empty(const struct sctp_outq *); 1069 void sctp_outq_restart(struct sctp_outq *); 1070 1071 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *, 1072 sctp_retransmit_reason_t); 1073 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); 1074 int sctp_outq_uncork(struct sctp_outq *); 1075 /* Uncork and flush an outqueue. */ 1076 static inline void sctp_outq_cork(struct sctp_outq *q) 1077 { 1078 q->cork = 1; 1079 } 1080 1081 /* These bind address data fields common between endpoints and associations */ 1082 struct sctp_bind_addr { 1083 1084 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1085 * 1086 * SCTP Port: The local SCTP port number the endpoint is 1087 * bound to. 1088 */ 1089 __u16 port; 1090 1091 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1092 * 1093 * Address List: The list of IP addresses that this instance 1094 * has bound. This information is passed to one's 1095 * peer(s) in INIT and INIT ACK chunks. 1096 */ 1097 struct list_head address_list; 1098 1099 int malloced; /* Are we kfree()able? */ 1100 }; 1101 1102 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port); 1103 void sctp_bind_addr_free(struct sctp_bind_addr *); 1104 int sctp_bind_addr_copy(struct sctp_bind_addr *dest, 1105 const struct sctp_bind_addr *src, 1106 sctp_scope_t scope, gfp_t gfp, 1107 int flags); 1108 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1109 gfp_t gfp); 1110 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *); 1111 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, 1112 struct sctp_sock *); 1113 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 1114 const union sctp_addr *addrs, 1115 int addrcnt, 1116 struct sctp_sock *opt); 1117 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 1118 int *addrs_len, 1119 gfp_t gfp); 1120 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, 1121 __u16 port, gfp_t gfp); 1122 1123 sctp_scope_t sctp_scope(const union sctp_addr *); 1124 int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope); 1125 int sctp_is_any(const union sctp_addr *addr); 1126 int sctp_addr_is_valid(const union sctp_addr *addr); 1127 1128 1129 /* What type of endpoint? */ 1130 typedef enum { 1131 SCTP_EP_TYPE_SOCKET, 1132 SCTP_EP_TYPE_ASSOCIATION, 1133 } sctp_endpoint_type_t; 1134 1135 /* 1136 * A common base class to bridge the implmentation view of a 1137 * socket (usually listening) endpoint versus an association's 1138 * local endpoint. 1139 * This common structure is useful for several purposes: 1140 * 1) Common interface for lookup routines. 1141 * a) Subfunctions work for either endpoint or association 1142 * b) Single interface to lookup allows hiding the lookup lock rather 1143 * than acquiring it externally. 1144 * 2) Common interface for the inbound chunk handling/state machine. 1145 * 3) Common object handling routines for reference counting, etc. 1146 * 4) Disentangle association lookup from endpoint lookup, where we 1147 * do not have to find our endpoint to find our association. 1148 * 1149 */ 1150 1151 struct sctp_ep_common { 1152 /* Fields to help us manage our entries in the hash tables. */ 1153 struct sctp_ep_common *next; 1154 struct sctp_ep_common **pprev; 1155 int hashent; 1156 1157 /* Runtime type information. What kind of endpoint is this? */ 1158 sctp_endpoint_type_t type; 1159 1160 /* Some fields to help us manage this object. 1161 * refcnt - Reference count access to this object. 1162 * dead - Do not attempt to use this object. 1163 * malloced - Do we need to kfree this object? 1164 */ 1165 atomic_t refcnt; 1166 char dead; 1167 char malloced; 1168 1169 /* What socket does this endpoint belong to? */ 1170 struct sock *sk; 1171 1172 /* This is where we receive inbound chunks. */ 1173 struct sctp_inq inqueue; 1174 1175 /* This substructure includes the defining parameters of the 1176 * endpoint: 1177 * bind_addr.port is our shared port number. 1178 * bind_addr.address_list is our set of local IP addresses. 1179 */ 1180 struct sctp_bind_addr bind_addr; 1181 1182 /* Protection during address list comparisons. */ 1183 rwlock_t addr_lock; 1184 }; 1185 1186 1187 /* RFC Section 1.4 Key Terms 1188 * 1189 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a 1190 * multi-homed host, an SCTP endpoint is represented to its peers as a 1191 * combination of a set of eligible destination transport addresses to 1192 * which SCTP packets can be sent and a set of eligible source 1193 * transport addresses from which SCTP packets can be received. 1194 * All transport addresses used by an SCTP endpoint must use the 1195 * same port number, but can use multiple IP addresses. A transport 1196 * address used by an SCTP endpoint must not be used by another 1197 * SCTP endpoint. In other words, a transport address is unique 1198 * to an SCTP endpoint. 1199 * 1200 * From an implementation perspective, each socket has one of these. 1201 * A TCP-style socket will have exactly one association on one of 1202 * these. An UDP-style socket will have multiple associations hanging 1203 * off one of these. 1204 */ 1205 1206 struct sctp_endpoint { 1207 /* Common substructure for endpoint and association. */ 1208 struct sctp_ep_common base; 1209 1210 /* Associations: A list of current associations and mappings 1211 * to the data consumers for each association. This 1212 * may be in the form of a hash table or other 1213 * implementation dependent structure. The data 1214 * consumers may be process identification 1215 * information such as file descriptors, named pipe 1216 * pointer, or table pointers dependent on how SCTP 1217 * is implemented. 1218 */ 1219 /* This is really a list of struct sctp_association entries. */ 1220 struct list_head asocs; 1221 1222 /* Secret Key: A secret key used by this endpoint to compute 1223 * the MAC. This SHOULD be a cryptographic quality 1224 * random number with a sufficient length. 1225 * Discussion in [RFC1750] can be helpful in 1226 * selection of the key. 1227 */ 1228 __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE]; 1229 int current_key; 1230 int last_key; 1231 int key_changed_at; 1232 1233 /* sendbuf acct. policy. */ 1234 __u32 sndbuf_policy; 1235 1236 /* rcvbuf acct. policy. */ 1237 __u32 rcvbuf_policy; 1238 }; 1239 1240 /* Recover the outter endpoint structure. */ 1241 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) 1242 { 1243 struct sctp_endpoint *ep; 1244 1245 ep = container_of(base, struct sctp_endpoint, base); 1246 return ep; 1247 } 1248 1249 /* These are function signatures for manipulating endpoints. */ 1250 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t); 1251 void sctp_endpoint_free(struct sctp_endpoint *); 1252 void sctp_endpoint_put(struct sctp_endpoint *); 1253 void sctp_endpoint_hold(struct sctp_endpoint *); 1254 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); 1255 struct sctp_association *sctp_endpoint_lookup_assoc( 1256 const struct sctp_endpoint *ep, 1257 const union sctp_addr *paddr, 1258 struct sctp_transport **); 1259 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *, 1260 const union sctp_addr *); 1261 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *, 1262 const union sctp_addr *); 1263 int sctp_has_association(const union sctp_addr *laddr, 1264 const union sctp_addr *paddr); 1265 1266 int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t, 1267 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk, 1268 struct sctp_chunk **err_chunk); 1269 int sctp_process_init(struct sctp_association *, sctp_cid_t cid, 1270 const union sctp_addr *peer, 1271 sctp_init_chunk_t *init, gfp_t gfp); 1272 __u32 sctp_generate_tag(const struct sctp_endpoint *); 1273 __u32 sctp_generate_tsn(const struct sctp_endpoint *); 1274 1275 1276 /* RFC2960 1277 * 1278 * 12. Recommended Transmission Control Block (TCB) Parameters 1279 * 1280 * This section details a recommended set of parameters that should 1281 * be contained within the TCB for an implementation. This section is 1282 * for illustrative purposes and should not be deemed as requirements 1283 * on an implementation or as an exhaustive list of all parameters 1284 * inside an SCTP TCB. Each implementation may need its own additional 1285 * parameters for optimization. 1286 */ 1287 1288 1289 /* Here we have information about each individual association. */ 1290 struct sctp_association { 1291 1292 /* A base structure common to endpoint and association. 1293 * In this context, it represents the associations's view 1294 * of the local endpoint of the association. 1295 */ 1296 struct sctp_ep_common base; 1297 1298 /* Associations on the same socket. */ 1299 struct list_head asocs; 1300 1301 /* association id. */ 1302 sctp_assoc_t assoc_id; 1303 1304 /* This is our parent endpoint. */ 1305 struct sctp_endpoint *ep; 1306 1307 /* These are those association elements needed in the cookie. */ 1308 struct sctp_cookie c; 1309 1310 /* This is all information about our peer. */ 1311 struct { 1312 /* rwnd 1313 * 1314 * Peer Rwnd : Current calculated value of the peer's rwnd. 1315 */ 1316 __u32 rwnd; 1317 1318 /* transport_addr_list 1319 * 1320 * Peer : A list of SCTP transport addresses that the 1321 * Transport : peer is bound to. This information is derived 1322 * Address : from the INIT or INIT ACK and is used to 1323 * List : associate an inbound packet with a given 1324 * : association. Normally this information is 1325 * : hashed or keyed for quick lookup and access 1326 * : of the TCB. 1327 * : The list is also initialized with the list 1328 * : of addresses passed with the sctp_connectx() 1329 * : call. 1330 * 1331 * It is a list of SCTP_transport's. 1332 */ 1333 struct list_head transport_addr_list; 1334 1335 /* transport_count 1336 * 1337 * Peer : A count of the number of peer addresses 1338 * Transport : in the Peer Transport Address List. 1339 * Address : 1340 * Count : 1341 */ 1342 __u16 transport_count; 1343 1344 /* port 1345 * The transport layer port number. 1346 */ 1347 __u16 port; 1348 1349 /* primary_path 1350 * 1351 * Primary : This is the current primary destination 1352 * Path : transport address of the peer endpoint. It 1353 * : may also specify a source transport address 1354 * : on this endpoint. 1355 * 1356 * All of these paths live on transport_addr_list. 1357 * 1358 * At the bakeoffs, we discovered that the intent of 1359 * primaryPath is that it only changes when the ULP 1360 * asks to have it changed. We add the activePath to 1361 * designate the connection we are currently using to 1362 * transmit new data and most control chunks. 1363 */ 1364 struct sctp_transport *primary_path; 1365 1366 /* Cache the primary path address here, when we 1367 * need a an address for msg_name. 1368 */ 1369 union sctp_addr primary_addr; 1370 1371 /* active_path 1372 * The path that we are currently using to 1373 * transmit new data and most control chunks. 1374 */ 1375 struct sctp_transport *active_path; 1376 1377 /* retran_path 1378 * 1379 * RFC2960 6.4 Multi-homed SCTP Endpoints 1380 * ... 1381 * Furthermore, when its peer is multi-homed, an 1382 * endpoint SHOULD try to retransmit a chunk to an 1383 * active destination transport address that is 1384 * different from the last destination address to 1385 * which the DATA chunk was sent. 1386 */ 1387 struct sctp_transport *retran_path; 1388 1389 /* Pointer to last transport I have sent on. */ 1390 struct sctp_transport *last_sent_to; 1391 1392 /* This is the last transport I have received DATA on. */ 1393 struct sctp_transport *last_data_from; 1394 1395 /* 1396 * Mapping An array of bits or bytes indicating which out of 1397 * Array order TSN's have been received (relative to the 1398 * Last Rcvd TSN). If no gaps exist, i.e. no out of 1399 * order packets have been received, this array 1400 * will be set to all zero. This structure may be 1401 * in the form of a circular buffer or bit array. 1402 * 1403 * Last Rcvd : This is the last TSN received in 1404 * TSN : sequence. This value is set initially by 1405 * : taking the peer's Initial TSN, received in 1406 * : the INIT or INIT ACK chunk, and subtracting 1407 * : one from it. 1408 * 1409 * Throughout most of the specification this is called the 1410 * "Cumulative TSN ACK Point". In this case, we 1411 * ignore the advice in 12.2 in favour of the term 1412 * used in the bulk of the text. This value is hidden 1413 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). 1414 */ 1415 struct sctp_tsnmap tsn_map; 1416 __u8 _map[sctp_tsnmap_storage_size(SCTP_TSN_MAP_SIZE)]; 1417 1418 /* Ack State : This flag indicates if the next received 1419 * : packet is to be responded to with a 1420 * : SACK. This is initializedto 0. When a packet 1421 * : is received it is incremented. If this value 1422 * : reaches 2 or more, a SACK is sent and the 1423 * : value is reset to 0. Note: This is used only 1424 * : when no DATA chunks are received out of 1425 * : order. When DATA chunks are out of order, 1426 * : SACK's are not delayed (see Section 6). 1427 */ 1428 __u8 sack_needed; /* Do we need to sack the peer? */ 1429 1430 /* These are capabilities which our peer advertised. */ 1431 __u8 ecn_capable; /* Can peer do ECN? */ 1432 __u8 ipv4_address; /* Peer understands IPv4 addresses? */ 1433 __u8 ipv6_address; /* Peer understands IPv6 addresses? */ 1434 __u8 hostname_address;/* Peer understands DNS addresses? */ 1435 __u8 asconf_capable; /* Does peer support ADDIP? */ 1436 __u8 prsctp_capable; /* Can peer do PR-SCTP? */ 1437 1438 __u32 adaption_ind; /* Adaption Code point. */ 1439 1440 /* This mask is used to disable sending the ASCONF chunk 1441 * with specified parameter to peer. 1442 */ 1443 __u16 addip_disabled_mask; 1444 1445 struct sctp_inithdr i; 1446 int cookie_len; 1447 void *cookie; 1448 1449 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1450 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the 1451 * Initial TSN Value minus 1 1452 */ 1453 __u32 addip_serial; 1454 } peer; 1455 1456 /* State : A state variable indicating what state the 1457 * : association is in, i.e. COOKIE-WAIT, 1458 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, 1459 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. 1460 * 1461 * Note: No "CLOSED" state is illustrated since if a 1462 * association is "CLOSED" its TCB SHOULD be removed. 1463 * 1464 * In this implementation we DO have a CLOSED 1465 * state which is used during initiation and shutdown. 1466 * 1467 * State takes values from SCTP_STATE_*. 1468 */ 1469 sctp_state_t state; 1470 1471 /* The cookie life I award for any cookie. */ 1472 struct timeval cookie_life; 1473 1474 /* Overall : The overall association error count. 1475 * Error Count : [Clear this any time I get something.] 1476 */ 1477 int overall_error_count; 1478 1479 /* These are the association's initial, max, and min RTO values. 1480 * These values will be initialized by system defaults, but can 1481 * be modified via the SCTP_RTOINFO socket option. 1482 */ 1483 __u32 rto_initial; 1484 __u32 rto_max; 1485 __u32 rto_min; 1486 1487 /* Maximum number of new data packets that can be sent in a burst. */ 1488 int max_burst; 1489 1490 /* This is the max_retrans value for the association. This value will 1491 * be initialized initialized from system defaults, but can be 1492 * modified by the SCTP_ASSOCINFO socket option. 1493 */ 1494 int max_retrans; 1495 1496 /* Maximum number of times the endpoint will retransmit INIT */ 1497 __u16 max_init_attempts; 1498 1499 /* How many times have we resent an INIT? */ 1500 __u16 init_retries; 1501 1502 /* The largest timeout or RTO value to use in attempting an INIT */ 1503 __u16 max_init_timeo; 1504 1505 int timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1506 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; 1507 1508 /* Transport to which SHUTDOWN chunk was last sent. */ 1509 struct sctp_transport *shutdown_last_sent_to; 1510 1511 /* Transport to which INIT chunk was last sent. */ 1512 struct sctp_transport *init_last_sent_to; 1513 1514 /* Next TSN : The next TSN number to be assigned to a new 1515 * : DATA chunk. This is sent in the INIT or INIT 1516 * : ACK chunk to the peer and incremented each 1517 * : time a DATA chunk is assigned a TSN 1518 * : (normally just prior to transmit or during 1519 * : fragmentation). 1520 */ 1521 __u32 next_tsn; 1522 1523 /* 1524 * Last Rcvd : This is the last TSN received in sequence. This value 1525 * TSN : is set initially by taking the peer's Initial TSN, 1526 * : received in the INIT or INIT ACK chunk, and 1527 * : subtracting one from it. 1528 * 1529 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. 1530 */ 1531 1532 __u32 ctsn_ack_point; 1533 1534 /* PR-SCTP Advanced.Peer.Ack.Point */ 1535 __u32 adv_peer_ack_point; 1536 1537 /* Highest TSN that is acknowledged by incoming SACKs. */ 1538 __u32 highest_sacked; 1539 1540 /* The number of unacknowledged data chunks. Reported through 1541 * the SCTP_STATUS sockopt. 1542 */ 1543 __u16 unack_data; 1544 1545 /* This is the association's receive buffer space. This value is used 1546 * to set a_rwnd field in an INIT or a SACK chunk. 1547 */ 1548 __u32 rwnd; 1549 1550 /* This is the last advertised value of rwnd over a SACK chunk. */ 1551 __u32 a_rwnd; 1552 1553 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed 1554 * to slop over a maximum of the association's frag_point. 1555 */ 1556 __u32 rwnd_over; 1557 1558 /* This is the sndbuf size in use for the association. 1559 * This corresponds to the sndbuf size for the association, 1560 * as specified in the sk->sndbuf. 1561 */ 1562 int sndbuf_used; 1563 1564 /* This is the amount of memory that this association has allocated 1565 * in the receive path at any given time. 1566 */ 1567 atomic_t rmem_alloc; 1568 1569 /* This is the wait queue head for send requests waiting on 1570 * the association sndbuf space. 1571 */ 1572 wait_queue_head_t wait; 1573 1574 /* Association : The smallest PMTU discovered for all of the 1575 * PMTU : peer's transport addresses. 1576 */ 1577 __u32 pmtu; 1578 1579 /* The message size at which SCTP fragmentation will occur. */ 1580 __u32 frag_point; 1581 1582 /* Counter used to count INIT errors. */ 1583 int init_err_counter; 1584 1585 /* Count the number of INIT cycles (for doubling timeout). */ 1586 int init_cycle; 1587 1588 /* Default send parameters. */ 1589 __u16 default_stream; 1590 __u16 default_flags; 1591 __u32 default_ppid; 1592 __u32 default_context; 1593 __u32 default_timetolive; 1594 1595 /* This tracks outbound ssn for a given stream. */ 1596 struct sctp_ssnmap *ssnmap; 1597 1598 /* All outbound chunks go through this structure. */ 1599 struct sctp_outq outqueue; 1600 1601 /* A smart pipe that will handle reordering and fragmentation, 1602 * as well as handle passing events up to the ULP. 1603 */ 1604 struct sctp_ulpq ulpq; 1605 1606 /* Last TSN that caused an ECNE Chunk to be sent. */ 1607 __u32 last_ecne_tsn; 1608 1609 /* Last TSN that caused a CWR Chunk to be sent. */ 1610 __u32 last_cwr_tsn; 1611 1612 /* How many duplicated TSNs have we seen? */ 1613 int numduptsns; 1614 1615 /* Number of seconds of idle time before an association is closed. */ 1616 __u32 autoclose; 1617 1618 /* These are to support 1619 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses 1620 * and Enforcement of Flow and Message Limits" 1621 * <draft-ietf-tsvwg-addip-sctp-02.txt> 1622 * or "ADDIP" for short. 1623 */ 1624 1625 1626 1627 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1628 * 1629 * R1) One and only one ASCONF Chunk MAY be in transit and 1630 * unacknowledged at any one time. If a sender, after sending 1631 * an ASCONF chunk, decides it needs to transfer another 1632 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1633 * returns from the previous ASCONF Chunk before sending a 1634 * subsequent ASCONF. Note this restriction binds each side, 1635 * so at any time two ASCONF may be in-transit on any given 1636 * association (one sent from each endpoint). 1637 * 1638 * [This is our one-and-only-one ASCONF in flight. If we do 1639 * not have an ASCONF in flight, this is NULL.] 1640 */ 1641 struct sctp_chunk *addip_last_asconf; 1642 1643 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1644 * 1645 * IMPLEMENTATION NOTE: As an optimization a receiver may wish 1646 * to save the last ASCONF-ACK for some predetermined period 1647 * of time and instead of re-processing the ASCONF (with the 1648 * same serial number) it may just re-transmit the 1649 * ASCONF-ACK. It may wish to use the arrival of a new serial 1650 * number to discard the previously saved ASCONF-ACK or any 1651 * other means it may choose to expire the saved ASCONF-ACK. 1652 * 1653 * [This is our saved ASCONF-ACK. We invalidate it when a new 1654 * ASCONF serial number arrives.] 1655 */ 1656 struct sctp_chunk *addip_last_asconf_ack; 1657 1658 /* These ASCONF chunks are waiting to be sent. 1659 * 1660 * These chunaks can't be pushed to outqueue until receiving 1661 * ASCONF_ACK for the previous ASCONF indicated by 1662 * addip_last_asconf, so as to guarantee that only one ASCONF 1663 * is in flight at any time. 1664 * 1665 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1666 * 1667 * In defining the ASCONF Chunk transfer procedures, it is 1668 * essential that these transfers MUST NOT cause congestion 1669 * within the network. To achieve this, we place these 1670 * restrictions on the transfer of ASCONF Chunks: 1671 * 1672 * R1) One and only one ASCONF Chunk MAY be in transit and 1673 * unacknowledged at any one time. If a sender, after sending 1674 * an ASCONF chunk, decides it needs to transfer another 1675 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1676 * returns from the previous ASCONF Chunk before sending a 1677 * subsequent ASCONF. Note this restriction binds each side, 1678 * so at any time two ASCONF may be in-transit on any given 1679 * association (one sent from each endpoint). 1680 * 1681 * 1682 * [I really think this is EXACTLY the sort of intelligence 1683 * which already resides in sctp_outq. Please move this 1684 * queue and its supporting logic down there. --piggy] 1685 */ 1686 struct list_head addip_chunk_list; 1687 1688 /* ADDIP Section 4.1 ASCONF Chunk Procedures 1689 * 1690 * A2) A serial number should be assigned to the Chunk. The 1691 * serial number SHOULD be a monotonically increasing 1692 * number. The serial number SHOULD be initialized at 1693 * the start of the association to the same value as the 1694 * Initial TSN and every time a new ASCONF chunk is created 1695 * it is incremented by one after assigning the serial number 1696 * to the newly created chunk. 1697 * 1698 * ADDIP 1699 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) 1700 * 1701 * Serial Number : 32 bits (unsigned integer) 1702 * 1703 * This value represents a Serial Number for the ASCONF 1704 * Chunk. The valid range of Serial Number is from 0 to 1705 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 1706 * after reaching 4294967295. 1707 */ 1708 __u32 addip_serial; 1709 1710 /* Need to send an ECNE Chunk? */ 1711 char need_ecne; 1712 1713 /* Is it a temporary association? */ 1714 char temp; 1715 }; 1716 1717 1718 /* An eyecatcher for determining if we are really looking at an 1719 * association data structure. 1720 */ 1721 enum { 1722 SCTP_ASSOC_EYECATCHER = 0xa550c123, 1723 }; 1724 1725 /* Recover the outter association structure. */ 1726 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) 1727 { 1728 struct sctp_association *asoc; 1729 1730 asoc = container_of(base, struct sctp_association, base); 1731 return asoc; 1732 } 1733 1734 /* These are function signatures for manipulating associations. */ 1735 1736 1737 struct sctp_association * 1738 sctp_association_new(const struct sctp_endpoint *, const struct sock *, 1739 sctp_scope_t scope, gfp_t gfp); 1740 void sctp_association_free(struct sctp_association *); 1741 void sctp_association_put(struct sctp_association *); 1742 void sctp_association_hold(struct sctp_association *); 1743 1744 struct sctp_transport *sctp_assoc_choose_init_transport( 1745 struct sctp_association *); 1746 struct sctp_transport *sctp_assoc_choose_shutdown_transport( 1747 struct sctp_association *); 1748 void sctp_assoc_update_retran_path(struct sctp_association *); 1749 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, 1750 const union sctp_addr *); 1751 int sctp_assoc_lookup_laddr(struct sctp_association *asoc, 1752 const union sctp_addr *laddr); 1753 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, 1754 const union sctp_addr *address, 1755 const gfp_t gfp, 1756 const int peer_state); 1757 void sctp_assoc_del_peer(struct sctp_association *asoc, 1758 const union sctp_addr *addr); 1759 void sctp_assoc_rm_peer(struct sctp_association *asoc, 1760 struct sctp_transport *peer); 1761 void sctp_assoc_control_transport(struct sctp_association *, 1762 struct sctp_transport *, 1763 sctp_transport_cmd_t, sctp_sn_error_t); 1764 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); 1765 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *, 1766 const union sctp_addr *, 1767 const union sctp_addr *); 1768 void sctp_assoc_migrate(struct sctp_association *, struct sock *); 1769 void sctp_assoc_update(struct sctp_association *old, 1770 struct sctp_association *new); 1771 1772 __u32 sctp_association_get_next_tsn(struct sctp_association *); 1773 1774 void sctp_assoc_sync_pmtu(struct sctp_association *); 1775 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned); 1776 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned); 1777 void sctp_assoc_set_primary(struct sctp_association *, 1778 struct sctp_transport *); 1779 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *, 1780 gfp_t); 1781 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, 1782 struct sctp_cookie*, 1783 gfp_t gfp); 1784 1785 int sctp_cmp_addr_exact(const union sctp_addr *ss1, 1786 const union sctp_addr *ss2); 1787 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); 1788 1789 /* A convenience structure to parse out SCTP specific CMSGs. */ 1790 typedef struct sctp_cmsgs { 1791 struct sctp_initmsg *init; 1792 struct sctp_sndrcvinfo *info; 1793 } sctp_cmsgs_t; 1794 1795 /* Structure for tracking memory objects */ 1796 typedef struct { 1797 char *label; 1798 atomic_t *counter; 1799 } sctp_dbg_objcnt_entry_t; 1800 1801 #endif /* __sctp_structs_h__ */ 1802