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 /* Delayed SACK timeout 200ms default*/ 165 int sack_timeout; 166 167 /* HB.interval - 30 seconds */ 168 int hb_interval; 169 170 /* The following variables are implementation specific. */ 171 172 /* Default initialization values to be applied to new associations. */ 173 __u16 max_instreams; 174 __u16 max_outstreams; 175 176 /* This is a list of groups of functions for each address 177 * family that we support. 178 */ 179 struct list_head address_families; 180 181 /* This is the hash of all endpoints. */ 182 int ep_hashsize; 183 struct sctp_hashbucket *ep_hashtable; 184 185 /* This is the hash of all associations. */ 186 int assoc_hashsize; 187 struct sctp_hashbucket *assoc_hashtable; 188 189 /* This is the sctp port control hash. */ 190 int port_hashsize; 191 int port_rover; 192 spinlock_t port_alloc_lock; /* Protects port_rover. */ 193 struct sctp_bind_hashbucket *port_hashtable; 194 195 /* This is the global local address list. 196 * We actively maintain this complete list of interfaces on 197 * the system by catching routing events. 198 * 199 * It is a list of sctp_sockaddr_entry. 200 */ 201 struct list_head local_addr_list; 202 spinlock_t local_addr_lock; 203 204 /* Flag to indicate if addip is enabled. */ 205 int addip_enable; 206 207 /* Flag to indicate if PR-SCTP is enabled. */ 208 int prsctp_enable; 209 } sctp_globals; 210 211 #define sctp_rto_initial (sctp_globals.rto_initial) 212 #define sctp_rto_min (sctp_globals.rto_min) 213 #define sctp_rto_max (sctp_globals.rto_max) 214 #define sctp_rto_alpha (sctp_globals.rto_alpha) 215 #define sctp_rto_beta (sctp_globals.rto_beta) 216 #define sctp_max_burst (sctp_globals.max_burst) 217 #define sctp_valid_cookie_life (sctp_globals.valid_cookie_life) 218 #define sctp_cookie_preserve_enable (sctp_globals.cookie_preserve_enable) 219 #define sctp_max_retrans_association (sctp_globals.max_retrans_association) 220 #define sctp_sndbuf_policy (sctp_globals.sndbuf_policy) 221 #define sctp_max_retrans_path (sctp_globals.max_retrans_path) 222 #define sctp_max_retrans_init (sctp_globals.max_retrans_init) 223 #define sctp_sack_timeout (sctp_globals.sack_timeout) 224 #define sctp_hb_interval (sctp_globals.hb_interval) 225 #define sctp_max_instreams (sctp_globals.max_instreams) 226 #define sctp_max_outstreams (sctp_globals.max_outstreams) 227 #define sctp_address_families (sctp_globals.address_families) 228 #define sctp_ep_hashsize (sctp_globals.ep_hashsize) 229 #define sctp_ep_hashtable (sctp_globals.ep_hashtable) 230 #define sctp_assoc_hashsize (sctp_globals.assoc_hashsize) 231 #define sctp_assoc_hashtable (sctp_globals.assoc_hashtable) 232 #define sctp_port_hashsize (sctp_globals.port_hashsize) 233 #define sctp_port_rover (sctp_globals.port_rover) 234 #define sctp_port_alloc_lock (sctp_globals.port_alloc_lock) 235 #define sctp_port_hashtable (sctp_globals.port_hashtable) 236 #define sctp_local_addr_list (sctp_globals.local_addr_list) 237 #define sctp_local_addr_lock (sctp_globals.local_addr_lock) 238 #define sctp_addip_enable (sctp_globals.addip_enable) 239 #define sctp_prsctp_enable (sctp_globals.prsctp_enable) 240 241 /* SCTP Socket type: UDP or TCP style. */ 242 typedef enum { 243 SCTP_SOCKET_UDP = 0, 244 SCTP_SOCKET_UDP_HIGH_BANDWIDTH, 245 SCTP_SOCKET_TCP 246 } sctp_socket_type_t; 247 248 /* Per socket SCTP information. */ 249 struct sctp_sock { 250 /* inet_sock has to be the first member of sctp_sock */ 251 struct inet_sock inet; 252 /* What kind of a socket is this? */ 253 sctp_socket_type_t type; 254 255 /* PF_ family specific functions. */ 256 struct sctp_pf *pf; 257 258 /* Access to HMAC transform. */ 259 struct crypto_tfm *hmac; 260 261 /* What is our base endpointer? */ 262 struct sctp_endpoint *ep; 263 264 struct sctp_bind_bucket *bind_hash; 265 /* Various Socket Options. */ 266 __u16 default_stream; 267 __u32 default_ppid; 268 __u16 default_flags; 269 __u32 default_context; 270 __u32 default_timetolive; 271 272 struct sctp_initmsg initmsg; 273 struct sctp_rtoinfo rtoinfo; 274 struct sctp_paddrparams paddrparam; 275 struct sctp_event_subscribe subscribe; 276 struct sctp_assocparams assocparams; 277 int user_frag; 278 __u32 autoclose; 279 __u8 nodelay; 280 __u8 disable_fragments; 281 __u8 pd_mode; 282 __u8 v4mapped; 283 __u32 adaption_ind; 284 285 /* Receive to here while partial delivery is in effect. */ 286 struct sk_buff_head pd_lobby; 287 }; 288 289 static inline struct sctp_sock *sctp_sk(const struct sock *sk) 290 { 291 return (struct sctp_sock *)sk; 292 } 293 294 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp) 295 { 296 return (struct sock *)sp; 297 } 298 299 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 300 struct sctp6_sock { 301 struct sctp_sock sctp; 302 struct ipv6_pinfo inet6; 303 }; 304 #endif /* CONFIG_IPV6 */ 305 306 307 /* This is our APPLICATION-SPECIFIC state cookie. 308 * THIS IS NOT DICTATED BY THE SPECIFICATION. 309 */ 310 /* These are the parts of an association which we send in the cookie. 311 * Most of these are straight out of: 312 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB) 313 * 314 */ 315 316 struct sctp_cookie { 317 318 /* My : Tag expected in every inbound packet and sent 319 * Verification: in the INIT or INIT ACK chunk. 320 * Tag : 321 */ 322 __u32 my_vtag; 323 324 /* Peer's : Tag expected in every outbound packet except 325 * Verification: in the INIT chunk. 326 * Tag : 327 */ 328 __u32 peer_vtag; 329 330 /* The rest of these are not from the spec, but really need to 331 * be in the cookie. 332 */ 333 334 /* My Tie Tag : Assist in discovering a restarting association. */ 335 __u32 my_ttag; 336 337 /* Peer's Tie Tag: Assist in discovering a restarting association. */ 338 __u32 peer_ttag; 339 340 /* When does this cookie expire? */ 341 struct timeval expiration; 342 343 /* Number of inbound/outbound streams which are set 344 * and negotiated during the INIT process. 345 */ 346 __u16 sinit_num_ostreams; 347 __u16 sinit_max_instreams; 348 349 /* This is the first sequence number I used. */ 350 __u32 initial_tsn; 351 352 /* This holds the originating address of the INIT packet. */ 353 union sctp_addr peer_addr; 354 355 /* IG Section 2.35.3 356 * Include the source port of the INIT-ACK 357 */ 358 __u16 my_port; 359 360 __u8 prsctp_capable; 361 362 /* Padding for future use */ 363 __u8 padding; 364 365 __u32 adaption_ind; 366 367 368 /* This is a shim for my peer's INIT packet, followed by 369 * a copy of the raw address list of the association. 370 * The length of the raw address list is saved in the 371 * raw_addr_list_len field, which will be used at the time when 372 * the association TCB is re-constructed from the cookie. 373 */ 374 __u32 raw_addr_list_len; 375 struct sctp_init_chunk peer_init[0]; 376 }; 377 378 379 /* The format of our cookie that we send to our peer. */ 380 struct sctp_signed_cookie { 381 __u8 signature[SCTP_SECRET_SIZE]; 382 struct sctp_cookie c; 383 }; 384 385 /* This is another convenience type to allocate memory for address 386 * params for the maximum size and pass such structures around 387 * internally. 388 */ 389 union sctp_addr_param { 390 struct sctp_ipv4addr_param v4; 391 struct sctp_ipv6addr_param v6; 392 }; 393 394 /* A convenience type to allow walking through the various 395 * parameters and avoid casting all over the place. 396 */ 397 union sctp_params { 398 void *v; 399 struct sctp_paramhdr *p; 400 struct sctp_cookie_preserve_param *life; 401 struct sctp_hostname_param *dns; 402 struct sctp_cookie_param *cookie; 403 struct sctp_supported_addrs_param *sat; 404 struct sctp_ipv4addr_param *v4; 405 struct sctp_ipv6addr_param *v6; 406 union sctp_addr_param *addr; 407 struct sctp_adaption_ind_param *aind; 408 }; 409 410 /* RFC 2960. Section 3.3.5 Heartbeat. 411 * Heartbeat Information: variable length 412 * The Sender-specific Heartbeat Info field should normally include 413 * information about the sender's current time when this HEARTBEAT 414 * chunk is sent and the destination transport address to which this 415 * HEARTBEAT is sent (see Section 8.3). 416 */ 417 typedef struct sctp_sender_hb_info { 418 struct sctp_paramhdr param_hdr; 419 union sctp_addr daddr; 420 unsigned long sent_at; 421 } __attribute__((packed)) sctp_sender_hb_info_t; 422 423 /* 424 * RFC 2960 1.3.2 Sequenced Delivery within Streams 425 * 426 * The term "stream" is used in SCTP to refer to a sequence of user 427 * messages that are to be delivered to the upper-layer protocol in 428 * order with respect to other messages within the same stream. This is 429 * in contrast to its usage in TCP, where it refers to a sequence of 430 * bytes (in this document a byte is assumed to be eight bits). 431 * ... 432 * 433 * This is the structure we use to track both our outbound and inbound 434 * SSN, or Stream Sequence Numbers. 435 */ 436 437 struct sctp_stream { 438 __u16 *ssn; 439 unsigned int len; 440 }; 441 442 struct sctp_ssnmap { 443 struct sctp_stream in; 444 struct sctp_stream out; 445 int malloced; 446 }; 447 448 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, 449 unsigned int __nocast gfp); 450 void sctp_ssnmap_free(struct sctp_ssnmap *map); 451 void sctp_ssnmap_clear(struct sctp_ssnmap *map); 452 453 /* What is the current SSN number for this stream? */ 454 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id) 455 { 456 return stream->ssn[id]; 457 } 458 459 /* Return the next SSN number for this stream. */ 460 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id) 461 { 462 return stream->ssn[id]++; 463 } 464 465 /* Skip over this ssn and all below. */ 466 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, 467 __u16 ssn) 468 { 469 stream->ssn[id] = ssn+1; 470 } 471 472 /* 473 * Pointers to address related SCTP functions. 474 * (i.e. things that depend on the address family.) 475 */ 476 struct sctp_af { 477 int (*sctp_xmit) (struct sk_buff *skb, 478 struct sctp_transport *, 479 int ipfragok); 480 int (*setsockopt) (struct sock *sk, 481 int level, 482 int optname, 483 char __user *optval, 484 int optlen); 485 int (*getsockopt) (struct sock *sk, 486 int level, 487 int optname, 488 char __user *optval, 489 int __user *optlen); 490 struct dst_entry *(*get_dst) (struct sctp_association *asoc, 491 union sctp_addr *daddr, 492 union sctp_addr *saddr); 493 void (*get_saddr) (struct sctp_association *asoc, 494 struct dst_entry *dst, 495 union sctp_addr *daddr, 496 union sctp_addr *saddr); 497 void (*copy_addrlist) (struct list_head *, 498 struct net_device *); 499 void (*dst_saddr) (union sctp_addr *saddr, 500 struct dst_entry *dst, 501 unsigned short port); 502 int (*cmp_addr) (const union sctp_addr *addr1, 503 const union sctp_addr *addr2); 504 void (*addr_copy) (union sctp_addr *dst, 505 union sctp_addr *src); 506 void (*from_skb) (union sctp_addr *, 507 struct sk_buff *skb, 508 int saddr); 509 void (*from_sk) (union sctp_addr *, 510 struct sock *sk); 511 void (*to_sk_saddr) (union sctp_addr *, 512 struct sock *sk); 513 void (*to_sk_daddr) (union sctp_addr *, 514 struct sock *sk); 515 void (*from_addr_param) (union sctp_addr *, 516 union sctp_addr_param *, 517 __u16 port, int iif); 518 int (*to_addr_param) (const union sctp_addr *, 519 union sctp_addr_param *); 520 int (*addr_valid) (union sctp_addr *, 521 struct sctp_sock *); 522 sctp_scope_t (*scope) (union sctp_addr *); 523 void (*inaddr_any) (union sctp_addr *, unsigned short); 524 int (*is_any) (const union sctp_addr *); 525 int (*available) (union sctp_addr *, 526 struct sctp_sock *); 527 int (*skb_iif) (const struct sk_buff *sk); 528 int (*is_ce) (const struct sk_buff *sk); 529 void (*seq_dump_addr)(struct seq_file *seq, 530 union sctp_addr *addr); 531 __u16 net_header_len; 532 int sockaddr_len; 533 sa_family_t sa_family; 534 struct list_head list; 535 }; 536 537 struct sctp_af *sctp_get_af_specific(sa_family_t); 538 int sctp_register_af(struct sctp_af *); 539 540 /* Protocol family functions. */ 541 struct sctp_pf { 542 void (*event_msgname)(struct sctp_ulpevent *, char *, int *); 543 void (*skb_msgname) (struct sk_buff *, char *, int *); 544 int (*af_supported) (sa_family_t, struct sctp_sock *); 545 int (*cmp_addr) (const union sctp_addr *, 546 const union sctp_addr *, 547 struct sctp_sock *); 548 int (*bind_verify) (struct sctp_sock *, union sctp_addr *); 549 int (*send_verify) (struct sctp_sock *, union sctp_addr *); 550 int (*supported_addrs)(const struct sctp_sock *, __u16 *); 551 struct sock *(*create_accept_sk) (struct sock *sk, 552 struct sctp_association *asoc); 553 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *); 554 struct sctp_af *af; 555 }; 556 557 558 /* Structure to track chunk fragments that have been acked, but peer 559 * fragments of the same message have not. 560 */ 561 struct sctp_datamsg { 562 /* Chunks waiting to be submitted to lower layer. */ 563 struct list_head chunks; 564 /* Chunks that have been transmitted. */ 565 struct list_head track; 566 /* Reference counting. */ 567 atomic_t refcnt; 568 /* When is this message no longer interesting to the peer? */ 569 unsigned long expires_at; 570 /* Did the messenge fail to send? */ 571 int send_error; 572 char send_failed; 573 /* Control whether chunks from this message can be abandoned. */ 574 char can_abandon; 575 }; 576 577 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, 578 struct sctp_sndrcvinfo *, 579 struct msghdr *, int len); 580 void sctp_datamsg_put(struct sctp_datamsg *); 581 void sctp_datamsg_free(struct sctp_datamsg *); 582 void sctp_datamsg_track(struct sctp_chunk *); 583 void sctp_chunk_fail(struct sctp_chunk *, int error); 584 int sctp_chunk_abandoned(struct sctp_chunk *); 585 586 /* RFC2960 1.4 Key Terms 587 * 588 * o Chunk: A unit of information within an SCTP packet, consisting of 589 * a chunk header and chunk-specific content. 590 * 591 * As a matter of convenience, we remember the SCTP common header for 592 * each chunk as well as a few other header pointers... 593 */ 594 struct sctp_chunk { 595 struct list_head list; 596 597 atomic_t refcnt; 598 599 /* This is our link to the per-transport transmitted list. */ 600 struct list_head transmitted_list; 601 602 /* This field is used by chunks that hold fragmented data. 603 * For the first fragment this is the list that holds the rest of 604 * fragments. For the remaining fragments, this is the link to the 605 * frag_list maintained in the first fragment. 606 */ 607 struct list_head frag_list; 608 609 /* This points to the sk_buff containing the actual data. */ 610 struct sk_buff *skb; 611 612 /* These are the SCTP headers by reverse order in a packet. 613 * Note that some of these may happen more than once. In that 614 * case, we point at the "current" one, whatever that means 615 * for that level of header. 616 */ 617 618 /* We point this at the FIRST TLV parameter to chunk_hdr. */ 619 union sctp_params param_hdr; 620 union { 621 __u8 *v; 622 struct sctp_datahdr *data_hdr; 623 struct sctp_inithdr *init_hdr; 624 struct sctp_sackhdr *sack_hdr; 625 struct sctp_heartbeathdr *hb_hdr; 626 struct sctp_sender_hb_info *hbs_hdr; 627 struct sctp_shutdownhdr *shutdown_hdr; 628 struct sctp_signed_cookie *cookie_hdr; 629 struct sctp_ecnehdr *ecne_hdr; 630 struct sctp_cwrhdr *ecn_cwr_hdr; 631 struct sctp_errhdr *err_hdr; 632 struct sctp_addiphdr *addip_hdr; 633 struct sctp_fwdtsn_hdr *fwdtsn_hdr; 634 } subh; 635 636 __u8 *chunk_end; 637 638 struct sctp_chunkhdr *chunk_hdr; 639 struct sctphdr *sctp_hdr; 640 641 /* This needs to be recoverable for SCTP_SEND_FAILED events. */ 642 struct sctp_sndrcvinfo sinfo; 643 644 /* Which association does this belong to? */ 645 struct sctp_association *asoc; 646 647 /* What endpoint received this chunk? */ 648 struct sctp_ep_common *rcvr; 649 650 /* We fill this in if we are calculating RTT. */ 651 unsigned long sent_at; 652 653 /* What is the origin IP address for this chunk? */ 654 union sctp_addr source; 655 /* Destination address for this chunk. */ 656 union sctp_addr dest; 657 658 /* For outbound message, track all fragments for SEND_FAILED. */ 659 struct sctp_datamsg *msg; 660 661 /* For an inbound chunk, this tells us where it came from. 662 * For an outbound chunk, it tells us where we'd like it to 663 * go. It is NULL if we have no preference. 664 */ 665 struct sctp_transport *transport; 666 667 __u8 rtt_in_progress; /* Is this chunk used for RTT calculation? */ 668 __u8 resent; /* Has this chunk ever been retransmitted. */ 669 __u8 has_tsn; /* Does this chunk have a TSN yet? */ 670 __u8 has_ssn; /* Does this chunk have a SSN yet? */ 671 __u8 singleton; /* Was this the only chunk in the packet? */ 672 __u8 end_of_packet; /* Was this the last chunk in the packet? */ 673 __u8 ecn_ce_done; /* Have we processed the ECN CE bit? */ 674 __u8 pdiscard; /* Discard the whole packet now? */ 675 __u8 tsn_gap_acked; /* Is this chunk acked by a GAP ACK? */ 676 __u8 fast_retransmit; /* Is this chunk fast retransmitted? */ 677 __u8 tsn_missing_report; /* Data chunk missing counter. */ 678 }; 679 680 void sctp_chunk_hold(struct sctp_chunk *); 681 void sctp_chunk_put(struct sctp_chunk *); 682 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 683 struct iovec *data); 684 void sctp_chunk_free(struct sctp_chunk *); 685 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); 686 struct sctp_chunk *sctp_chunkify(struct sk_buff *, 687 const struct sctp_association *, 688 struct sock *); 689 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, 690 union sctp_addr *); 691 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); 692 693 /* This is a structure for holding either an IPv6 or an IPv4 address. */ 694 /* sin_family -- AF_INET or AF_INET6 695 * sin_port -- ordinary port number 696 * sin_addr -- cast to either (struct in_addr) or (struct in6_addr) 697 */ 698 struct sctp_sockaddr_entry { 699 struct list_head list; 700 union sctp_addr a; 701 }; 702 703 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *); 704 705 /* This structure holds lists of chunks as we are assembling for 706 * transmission. 707 */ 708 struct sctp_packet { 709 /* These are the SCTP header values (host order) for the packet. */ 710 __u16 source_port; 711 __u16 destination_port; 712 __u32 vtag; 713 714 /* This contains the payload chunks. */ 715 struct list_head chunk_list; 716 717 /* This is the overhead of the sctp and ip headers. */ 718 size_t overhead; 719 /* This is the total size of all chunks INCLUDING padding. */ 720 size_t size; 721 722 /* The packet is destined for this transport address. 723 * The function we finally use to pass down to the next lower 724 * layer lives in the transport structure. 725 */ 726 struct sctp_transport *transport; 727 728 /* This packet contains a COOKIE-ECHO chunk. */ 729 char has_cookie_echo; 730 731 /* This packet containsa SACK chunk. */ 732 char has_sack; 733 734 /* SCTP cannot fragment this packet. So let ip fragment it. */ 735 char ipfragok; 736 737 int malloced; 738 }; 739 740 struct sctp_packet *sctp_packet_init(struct sctp_packet *, 741 struct sctp_transport *, 742 __u16 sport, __u16 dport); 743 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int); 744 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *, 745 struct sctp_chunk *); 746 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *, 747 struct sctp_chunk *); 748 int sctp_packet_transmit(struct sctp_packet *); 749 void sctp_packet_free(struct sctp_packet *); 750 751 static inline int sctp_packet_empty(struct sctp_packet *packet) 752 { 753 return (packet->size == packet->overhead); 754 } 755 756 /* This represents a remote transport address. 757 * For local transport addresses, we just use union sctp_addr. 758 * 759 * RFC2960 Section 1.4 Key Terms 760 * 761 * o Transport address: A Transport Address is traditionally defined 762 * by Network Layer address, Transport Layer protocol and Transport 763 * Layer port number. In the case of SCTP running over IP, a 764 * transport address is defined by the combination of an IP address 765 * and an SCTP port number (where SCTP is the Transport protocol). 766 * 767 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control 768 * 769 * o The sender keeps a separate congestion control parameter set for 770 * each of the destination addresses it can send to (not each 771 * source-destination pair but for each destination). The parameters 772 * should decay if the address is not used for a long enough time 773 * period. 774 * 775 */ 776 struct sctp_transport { 777 /* A list of transports. */ 778 struct list_head transports; 779 780 /* Reference counting. */ 781 atomic_t refcnt; 782 int dead; 783 784 /* This is the peer's IP address and port. */ 785 union sctp_addr ipaddr; 786 787 /* These are the functions we call to handle LLP stuff. */ 788 struct sctp_af *af_specific; 789 790 /* Which association do we belong to? */ 791 struct sctp_association *asoc; 792 793 /* RFC2960 794 * 795 * 12.3 Per Transport Address Data 796 * 797 * For each destination transport address in the peer's 798 * address list derived from the INIT or INIT ACK chunk, a 799 * number of data elements needs to be maintained including: 800 */ 801 __u32 rtt; /* This is the most recent RTT. */ 802 803 /* RTO : The current retransmission timeout value. */ 804 __u32 rto; 805 806 /* RTTVAR : The current RTT variation. */ 807 __u32 rttvar; 808 809 /* SRTT : The current smoothed round trip time. */ 810 __u32 srtt; 811 812 /* RTO-Pending : A flag used to track if one of the DATA 813 * chunks sent to this address is currently being 814 * used to compute a RTT. If this flag is 0, 815 * the next DATA chunk sent to this destination 816 * should be used to compute a RTT and this flag 817 * should be set. Every time the RTT 818 * calculation completes (i.e. the DATA chunk 819 * is SACK'd) clear this flag. 820 */ 821 int rto_pending; 822 823 /* 824 * These are the congestion stats. 825 */ 826 /* cwnd : The current congestion window. */ 827 __u32 cwnd; /* This is the actual cwnd. */ 828 829 /* ssthresh : The current slow start threshold value. */ 830 __u32 ssthresh; 831 832 /* partial : The tracking method for increase of cwnd when in 833 * bytes acked : congestion avoidance mode (see Section 6.2.2) 834 */ 835 __u32 partial_bytes_acked; 836 837 /* Data that has been sent, but not acknowledged. */ 838 __u32 flight_size; 839 840 /* PMTU : The current known path MTU. */ 841 __u32 pmtu; 842 843 /* Destination */ 844 struct dst_entry *dst; 845 /* Source address. */ 846 union sctp_addr saddr; 847 848 /* When was the last time(in jiffies) that a data packet was sent on 849 * this transport? This is used to adjust the cwnd when the transport 850 * becomes inactive. 851 */ 852 unsigned long last_time_used; 853 854 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 855 * the destination address every heartbeat interval. 856 */ 857 int hb_interval; 858 859 /* When was the last time (in jiffies) that we heard from this 860 * transport? We use this to pick new active and retran paths. 861 */ 862 unsigned long last_time_heard; 863 864 /* Last time(in jiffies) when cwnd is reduced due to the congestion 865 * indication based on ECNE chunk. 866 */ 867 unsigned long last_time_ecne_reduced; 868 869 /* The number of times INIT has been sent on this transport. */ 870 int init_sent_count; 871 872 /* state : The current state of this destination, 873 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKOWN. 874 */ 875 int state; 876 877 /* hb_allowed : The current heartbeat state of this destination, 878 * : i.e. ALLOW-HB, NO-HEARTBEAT, etc. 879 */ 880 int hb_allowed; 881 882 /* These are the error stats for this destination. */ 883 884 /* Error count : The current error count for this destination. */ 885 unsigned short error_count; 886 887 /* This is the max_retrans value for the transport and will 888 * be initialized to proto.max_retrans.path. This can be changed 889 * using SCTP_SET_PEER_ADDR_PARAMS socket option. 890 */ 891 int max_retrans; 892 893 /* Per : A timer used by each destination. 894 * Destination : 895 * Timer : 896 * 897 * [Everywhere else in the text this is called T3-rtx. -ed] 898 */ 899 struct timer_list T3_rtx_timer; 900 901 /* Heartbeat timer is per destination. */ 902 struct timer_list hb_timer; 903 904 /* Since we're using per-destination retransmission timers 905 * (see above), we're also using per-destination "transmitted" 906 * queues. This probably ought to be a private struct 907 * accessible only within the outqueue, but it's not, yet. 908 */ 909 struct list_head transmitted; 910 911 /* We build bundle-able packets for this transport here. */ 912 struct sctp_packet packet; 913 914 /* This is the list of transports that have chunks to send. */ 915 struct list_head send_ready; 916 917 int malloced; /* Is this structure kfree()able? */ 918 919 /* State information saved for SFR_CACC algorithm. The key 920 * idea in SFR_CACC is to maintain state at the sender on a 921 * per-destination basis when a changeover happens. 922 * char changeover_active; 923 * char cycling_changeover; 924 * __u32 next_tsn_at_change; 925 * char cacc_saw_newack; 926 */ 927 struct { 928 /* An unsigned integer, which stores the next TSN to be 929 * used by the sender, at the moment of changeover. 930 */ 931 __u32 next_tsn_at_change; 932 933 /* A flag which indicates the occurrence of a changeover */ 934 char changeover_active; 935 936 /* A flag which indicates whether the change of primary is 937 * the first switch to this destination address during an 938 * active switch. 939 */ 940 char cycling_changeover; 941 942 /* A temporary flag, which is used during the processing of 943 * a SACK to estimate the causative TSN(s)'s group. 944 */ 945 char cacc_saw_newack; 946 } cacc; 947 }; 948 949 struct sctp_transport *sctp_transport_new(const union sctp_addr *, 950 unsigned int __nocast); 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 list_head in_chunk_list; 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 list_head out_chunk_list; 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 list_head control_chunk_list; 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, unsigned int __nocast gfp, 1099 int flags); 1100 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1101 unsigned int __nocast gfp); 1102 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *); 1103 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, 1104 struct sctp_sock *); 1105 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 1106 const union sctp_addr *addrs, 1107 int addrcnt, 1108 struct sctp_sock *opt); 1109 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 1110 int *addrs_len, 1111 unsigned int __nocast gfp); 1112 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, 1113 __u16 port, unsigned int __nocast gfp); 1114 1115 sctp_scope_t sctp_scope(const union sctp_addr *); 1116 int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope); 1117 int sctp_is_any(const union sctp_addr *addr); 1118 int sctp_addr_is_valid(const union sctp_addr *addr); 1119 1120 1121 /* What type of endpoint? */ 1122 typedef enum { 1123 SCTP_EP_TYPE_SOCKET, 1124 SCTP_EP_TYPE_ASSOCIATION, 1125 } sctp_endpoint_type_t; 1126 1127 /* 1128 * A common base class to bridge the implmentation view of a 1129 * socket (usually listening) endpoint versus an association's 1130 * local endpoint. 1131 * This common structure is useful for several purposes: 1132 * 1) Common interface for lookup routines. 1133 * a) Subfunctions work for either endpoint or association 1134 * b) Single interface to lookup allows hiding the lookup lock rather 1135 * than acquiring it externally. 1136 * 2) Common interface for the inbound chunk handling/state machine. 1137 * 3) Common object handling routines for reference counting, etc. 1138 * 4) Disentangle association lookup from endpoint lookup, where we 1139 * do not have to find our endpoint to find our association. 1140 * 1141 */ 1142 1143 struct sctp_ep_common { 1144 /* Fields to help us manage our entries in the hash tables. */ 1145 struct sctp_ep_common *next; 1146 struct sctp_ep_common **pprev; 1147 int hashent; 1148 1149 /* Runtime type information. What kind of endpoint is this? */ 1150 sctp_endpoint_type_t type; 1151 1152 /* Some fields to help us manage this object. 1153 * refcnt - Reference count access to this object. 1154 * dead - Do not attempt to use this object. 1155 * malloced - Do we need to kfree this object? 1156 */ 1157 atomic_t refcnt; 1158 char dead; 1159 char malloced; 1160 1161 /* What socket does this endpoint belong to? */ 1162 struct sock *sk; 1163 1164 /* This is where we receive inbound chunks. */ 1165 struct sctp_inq inqueue; 1166 1167 /* This substructure includes the defining parameters of the 1168 * endpoint: 1169 * bind_addr.port is our shared port number. 1170 * bind_addr.address_list is our set of local IP addresses. 1171 */ 1172 struct sctp_bind_addr bind_addr; 1173 1174 /* Protection during address list comparisons. */ 1175 rwlock_t addr_lock; 1176 }; 1177 1178 1179 /* RFC Section 1.4 Key Terms 1180 * 1181 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a 1182 * multi-homed host, an SCTP endpoint is represented to its peers as a 1183 * combination of a set of eligible destination transport addresses to 1184 * which SCTP packets can be sent and a set of eligible source 1185 * transport addresses from which SCTP packets can be received. 1186 * All transport addresses used by an SCTP endpoint must use the 1187 * same port number, but can use multiple IP addresses. A transport 1188 * address used by an SCTP endpoint must not be used by another 1189 * SCTP endpoint. In other words, a transport address is unique 1190 * to an SCTP endpoint. 1191 * 1192 * From an implementation perspective, each socket has one of these. 1193 * A TCP-style socket will have exactly one association on one of 1194 * these. An UDP-style socket will have multiple associations hanging 1195 * off one of these. 1196 */ 1197 1198 struct sctp_endpoint { 1199 /* Common substructure for endpoint and association. */ 1200 struct sctp_ep_common base; 1201 1202 /* Associations: A list of current associations and mappings 1203 * to the data consumers for each association. This 1204 * may be in the form of a hash table or other 1205 * implementation dependent structure. The data 1206 * consumers may be process identification 1207 * information such as file descriptors, named pipe 1208 * pointer, or table pointers dependent on how SCTP 1209 * is implemented. 1210 */ 1211 /* This is really a list of struct sctp_association entries. */ 1212 struct list_head asocs; 1213 1214 /* Secret Key: A secret key used by this endpoint to compute 1215 * the MAC. This SHOULD be a cryptographic quality 1216 * random number with a sufficient length. 1217 * Discussion in [RFC1750] can be helpful in 1218 * selection of the key. 1219 */ 1220 __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE]; 1221 int current_key; 1222 int last_key; 1223 int key_changed_at; 1224 1225 /* Default timeouts. */ 1226 int timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1227 1228 /* sendbuf acct. policy. */ 1229 __u32 sndbuf_policy; 1230 }; 1231 1232 /* Recover the outter endpoint structure. */ 1233 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) 1234 { 1235 struct sctp_endpoint *ep; 1236 1237 ep = container_of(base, struct sctp_endpoint, base); 1238 return ep; 1239 } 1240 1241 /* These are function signatures for manipulating endpoints. */ 1242 struct sctp_endpoint *sctp_endpoint_new(struct sock *, unsigned int __nocast); 1243 void sctp_endpoint_free(struct sctp_endpoint *); 1244 void sctp_endpoint_put(struct sctp_endpoint *); 1245 void sctp_endpoint_hold(struct sctp_endpoint *); 1246 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); 1247 struct sctp_association *sctp_endpoint_lookup_assoc( 1248 const struct sctp_endpoint *ep, 1249 const union sctp_addr *paddr, 1250 struct sctp_transport **); 1251 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *, 1252 const union sctp_addr *); 1253 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *, 1254 const union sctp_addr *); 1255 int sctp_has_association(const union sctp_addr *laddr, 1256 const union sctp_addr *paddr); 1257 1258 int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t, 1259 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk, 1260 struct sctp_chunk **err_chunk); 1261 int sctp_process_init(struct sctp_association *, sctp_cid_t cid, 1262 const union sctp_addr *peer, 1263 sctp_init_chunk_t *init, unsigned int __nocast gfp); 1264 __u32 sctp_generate_tag(const struct sctp_endpoint *); 1265 __u32 sctp_generate_tsn(const struct sctp_endpoint *); 1266 1267 1268 /* RFC2960 1269 * 1270 * 12. Recommended Transmission Control Block (TCB) Parameters 1271 * 1272 * This section details a recommended set of parameters that should 1273 * be contained within the TCB for an implementation. This section is 1274 * for illustrative purposes and should not be deemed as requirements 1275 * on an implementation or as an exhaustive list of all parameters 1276 * inside an SCTP TCB. Each implementation may need its own additional 1277 * parameters for optimization. 1278 */ 1279 1280 1281 /* Here we have information about each individual association. */ 1282 struct sctp_association { 1283 1284 /* A base structure common to endpoint and association. 1285 * In this context, it represents the associations's view 1286 * of the local endpoint of the association. 1287 */ 1288 struct sctp_ep_common base; 1289 1290 /* Associations on the same socket. */ 1291 struct list_head asocs; 1292 1293 /* association id. */ 1294 sctp_assoc_t assoc_id; 1295 1296 /* This is our parent endpoint. */ 1297 struct sctp_endpoint *ep; 1298 1299 /* These are those association elements needed in the cookie. */ 1300 struct sctp_cookie c; 1301 1302 /* This is all information about our peer. */ 1303 struct { 1304 /* rwnd 1305 * 1306 * Peer Rwnd : Current calculated value of the peer's rwnd. 1307 */ 1308 __u32 rwnd; 1309 1310 /* transport_addr_list 1311 * 1312 * Peer : A list of SCTP transport addresses that the 1313 * Transport : peer is bound to. This information is derived 1314 * Address : from the INIT or INIT ACK and is used to 1315 * List : associate an inbound packet with a given 1316 * : association. Normally this information is 1317 * : hashed or keyed for quick lookup and access 1318 * : of the TCB. 1319 * : The list is also initialized with the list 1320 * : of addresses passed with the sctp_connectx() 1321 * : call. 1322 * 1323 * It is a list of SCTP_transport's. 1324 */ 1325 struct list_head transport_addr_list; 1326 1327 /* transport_count 1328 * 1329 * Peer : A count of the number of peer addresses 1330 * Transport : in the Peer Transport Address List. 1331 * Address : 1332 * Count : 1333 */ 1334 __u16 transport_count; 1335 1336 /* port 1337 * The transport layer port number. 1338 */ 1339 __u16 port; 1340 1341 /* primary_path 1342 * 1343 * Primary : This is the current primary destination 1344 * Path : transport address of the peer endpoint. It 1345 * : may also specify a source transport address 1346 * : on this endpoint. 1347 * 1348 * All of these paths live on transport_addr_list. 1349 * 1350 * At the bakeoffs, we discovered that the intent of 1351 * primaryPath is that it only changes when the ULP 1352 * asks to have it changed. We add the activePath to 1353 * designate the connection we are currently using to 1354 * transmit new data and most control chunks. 1355 */ 1356 struct sctp_transport *primary_path; 1357 1358 /* Cache the primary path address here, when we 1359 * need a an address for msg_name. 1360 */ 1361 union sctp_addr primary_addr; 1362 1363 /* active_path 1364 * The path that we are currently using to 1365 * transmit new data and most control chunks. 1366 */ 1367 struct sctp_transport *active_path; 1368 1369 /* retran_path 1370 * 1371 * RFC2960 6.4 Multi-homed SCTP Endpoints 1372 * ... 1373 * Furthermore, when its peer is multi-homed, an 1374 * endpoint SHOULD try to retransmit a chunk to an 1375 * active destination transport address that is 1376 * different from the last destination address to 1377 * which the DATA chunk was sent. 1378 */ 1379 struct sctp_transport *retran_path; 1380 1381 /* Pointer to last transport I have sent on. */ 1382 struct sctp_transport *last_sent_to; 1383 1384 /* This is the last transport I have received DATA on. */ 1385 struct sctp_transport *last_data_from; 1386 1387 /* 1388 * Mapping An array of bits or bytes indicating which out of 1389 * Array order TSN's have been received (relative to the 1390 * Last Rcvd TSN). If no gaps exist, i.e. no out of 1391 * order packets have been received, this array 1392 * will be set to all zero. This structure may be 1393 * in the form of a circular buffer or bit array. 1394 * 1395 * Last Rcvd : This is the last TSN received in 1396 * TSN : sequence. This value is set initially by 1397 * : taking the peer's Initial TSN, received in 1398 * : the INIT or INIT ACK chunk, and subtracting 1399 * : one from it. 1400 * 1401 * Throughout most of the specification this is called the 1402 * "Cumulative TSN ACK Point". In this case, we 1403 * ignore the advice in 12.2 in favour of the term 1404 * used in the bulk of the text. This value is hidden 1405 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). 1406 */ 1407 struct sctp_tsnmap tsn_map; 1408 __u8 _map[sctp_tsnmap_storage_size(SCTP_TSN_MAP_SIZE)]; 1409 1410 /* Ack State : This flag indicates if the next received 1411 * : packet is to be responded to with a 1412 * : SACK. This is initializedto 0. When a packet 1413 * : is received it is incremented. If this value 1414 * : reaches 2 or more, a SACK is sent and the 1415 * : value is reset to 0. Note: This is used only 1416 * : when no DATA chunks are received out of 1417 * : order. When DATA chunks are out of order, 1418 * : SACK's are not delayed (see Section 6). 1419 */ 1420 __u8 sack_needed; /* Do we need to sack the peer? */ 1421 1422 /* These are capabilities which our peer advertised. */ 1423 __u8 ecn_capable; /* Can peer do ECN? */ 1424 __u8 ipv4_address; /* Peer understands IPv4 addresses? */ 1425 __u8 ipv6_address; /* Peer understands IPv6 addresses? */ 1426 __u8 hostname_address;/* Peer understands DNS addresses? */ 1427 __u8 asconf_capable; /* Does peer support ADDIP? */ 1428 __u8 prsctp_capable; /* Can peer do PR-SCTP? */ 1429 1430 __u32 adaption_ind; /* Adaption Code point. */ 1431 1432 /* This mask is used to disable sending the ASCONF chunk 1433 * with specified parameter to peer. 1434 */ 1435 __u16 addip_disabled_mask; 1436 1437 struct sctp_inithdr i; 1438 int cookie_len; 1439 void *cookie; 1440 1441 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1442 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the 1443 * Initial TSN Value minus 1 1444 */ 1445 __u32 addip_serial; 1446 } peer; 1447 1448 /* State : A state variable indicating what state the 1449 * : association is in, i.e. COOKIE-WAIT, 1450 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, 1451 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. 1452 * 1453 * Note: No "CLOSED" state is illustrated since if a 1454 * association is "CLOSED" its TCB SHOULD be removed. 1455 * 1456 * In this implementation we DO have a CLOSED 1457 * state which is used during initiation and shutdown. 1458 * 1459 * State takes values from SCTP_STATE_*. 1460 */ 1461 sctp_state_t state; 1462 1463 /* The cookie life I award for any cookie. */ 1464 struct timeval cookie_life; 1465 1466 /* Overall : The overall association error count. 1467 * Error Count : [Clear this any time I get something.] 1468 */ 1469 int overall_error_count; 1470 1471 /* These are the association's initial, max, and min RTO values. 1472 * These values will be initialized by system defaults, but can 1473 * be modified via the SCTP_RTOINFO socket option. 1474 */ 1475 __u32 rto_initial; 1476 __u32 rto_max; 1477 __u32 rto_min; 1478 1479 /* Maximum number of new data packets that can be sent in a burst. */ 1480 int max_burst; 1481 1482 /* This is the max_retrans value for the association. This value will 1483 * be initialized initialized from system defaults, but can be 1484 * modified by the SCTP_ASSOCINFO socket option. 1485 */ 1486 int max_retrans; 1487 1488 /* Maximum number of times the endpoint will retransmit INIT */ 1489 __u16 max_init_attempts; 1490 1491 /* How many times have we resent an INIT? */ 1492 __u16 init_retries; 1493 1494 /* The largest timeout or RTO value to use in attempting an INIT */ 1495 __u16 max_init_timeo; 1496 1497 int timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1498 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; 1499 1500 /* Transport to which SHUTDOWN chunk was last sent. */ 1501 struct sctp_transport *shutdown_last_sent_to; 1502 1503 /* Transport to which INIT chunk was last sent. */ 1504 struct sctp_transport *init_last_sent_to; 1505 1506 /* Next TSN : The next TSN number to be assigned to a new 1507 * : DATA chunk. This is sent in the INIT or INIT 1508 * : ACK chunk to the peer and incremented each 1509 * : time a DATA chunk is assigned a TSN 1510 * : (normally just prior to transmit or during 1511 * : fragmentation). 1512 */ 1513 __u32 next_tsn; 1514 1515 /* 1516 * Last Rcvd : This is the last TSN received in sequence. This value 1517 * TSN : is set initially by taking the peer's Initial TSN, 1518 * : received in the INIT or INIT ACK chunk, and 1519 * : subtracting one from it. 1520 * 1521 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. 1522 */ 1523 1524 __u32 ctsn_ack_point; 1525 1526 /* PR-SCTP Advanced.Peer.Ack.Point */ 1527 __u32 adv_peer_ack_point; 1528 1529 /* Highest TSN that is acknowledged by incoming SACKs. */ 1530 __u32 highest_sacked; 1531 1532 /* The number of unacknowledged data chunks. Reported through 1533 * the SCTP_STATUS sockopt. 1534 */ 1535 __u16 unack_data; 1536 1537 /* This is the association's receive buffer space. This value is used 1538 * to set a_rwnd field in an INIT or a SACK chunk. 1539 */ 1540 __u32 rwnd; 1541 1542 /* This is the last advertised value of rwnd over a SACK chunk. */ 1543 __u32 a_rwnd; 1544 1545 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed 1546 * to slop over a maximum of the association's frag_point. 1547 */ 1548 __u32 rwnd_over; 1549 1550 /* This is the sndbuf size in use for the association. 1551 * This corresponds to the sndbuf size for the association, 1552 * as specified in the sk->sndbuf. 1553 */ 1554 int sndbuf_used; 1555 1556 /* This is the wait queue head for send requests waiting on 1557 * the association sndbuf space. 1558 */ 1559 wait_queue_head_t wait; 1560 1561 /* Association : The smallest PMTU discovered for all of the 1562 * PMTU : peer's transport addresses. 1563 */ 1564 __u32 pmtu; 1565 1566 /* The message size at which SCTP fragmentation will occur. */ 1567 __u32 frag_point; 1568 1569 /* Counter used to count INIT errors. */ 1570 int init_err_counter; 1571 1572 /* Count the number of INIT cycles (for doubling timeout). */ 1573 int init_cycle; 1574 1575 /* Default send parameters. */ 1576 __u16 default_stream; 1577 __u16 default_flags; 1578 __u32 default_ppid; 1579 __u32 default_context; 1580 __u32 default_timetolive; 1581 1582 /* This tracks outbound ssn for a given stream. */ 1583 struct sctp_ssnmap *ssnmap; 1584 1585 /* All outbound chunks go through this structure. */ 1586 struct sctp_outq outqueue; 1587 1588 /* A smart pipe that will handle reordering and fragmentation, 1589 * as well as handle passing events up to the ULP. 1590 */ 1591 struct sctp_ulpq ulpq; 1592 1593 /* Last TSN that caused an ECNE Chunk to be sent. */ 1594 __u32 last_ecne_tsn; 1595 1596 /* Last TSN that caused a CWR Chunk to be sent. */ 1597 __u32 last_cwr_tsn; 1598 1599 /* How many duplicated TSNs have we seen? */ 1600 int numduptsns; 1601 1602 /* Number of seconds of idle time before an association is closed. */ 1603 __u32 autoclose; 1604 1605 /* These are to support 1606 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses 1607 * and Enforcement of Flow and Message Limits" 1608 * <draft-ietf-tsvwg-addip-sctp-02.txt> 1609 * or "ADDIP" for short. 1610 */ 1611 1612 1613 1614 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1615 * 1616 * R1) One and only one ASCONF Chunk MAY be in transit and 1617 * unacknowledged at any one time. If a sender, after sending 1618 * an ASCONF chunk, decides it needs to transfer another 1619 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1620 * returns from the previous ASCONF Chunk before sending a 1621 * subsequent ASCONF. Note this restriction binds each side, 1622 * so at any time two ASCONF may be in-transit on any given 1623 * association (one sent from each endpoint). 1624 * 1625 * [This is our one-and-only-one ASCONF in flight. If we do 1626 * not have an ASCONF in flight, this is NULL.] 1627 */ 1628 struct sctp_chunk *addip_last_asconf; 1629 1630 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1631 * 1632 * IMPLEMENTATION NOTE: As an optimization a receiver may wish 1633 * to save the last ASCONF-ACK for some predetermined period 1634 * of time and instead of re-processing the ASCONF (with the 1635 * same serial number) it may just re-transmit the 1636 * ASCONF-ACK. It may wish to use the arrival of a new serial 1637 * number to discard the previously saved ASCONF-ACK or any 1638 * other means it may choose to expire the saved ASCONF-ACK. 1639 * 1640 * [This is our saved ASCONF-ACK. We invalidate it when a new 1641 * ASCONF serial number arrives.] 1642 */ 1643 struct sctp_chunk *addip_last_asconf_ack; 1644 1645 /* These ASCONF chunks are waiting to be sent. 1646 * 1647 * These chunaks can't be pushed to outqueue until receiving 1648 * ASCONF_ACK for the previous ASCONF indicated by 1649 * addip_last_asconf, so as to guarantee that only one ASCONF 1650 * is in flight at any time. 1651 * 1652 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1653 * 1654 * In defining the ASCONF Chunk transfer procedures, it is 1655 * essential that these transfers MUST NOT cause congestion 1656 * within the network. To achieve this, we place these 1657 * restrictions on the transfer of ASCONF Chunks: 1658 * 1659 * R1) One and only one ASCONF Chunk MAY be in transit and 1660 * unacknowledged at any one time. If a sender, after sending 1661 * an ASCONF chunk, decides it needs to transfer another 1662 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1663 * returns from the previous ASCONF Chunk before sending a 1664 * subsequent ASCONF. Note this restriction binds each side, 1665 * so at any time two ASCONF may be in-transit on any given 1666 * association (one sent from each endpoint). 1667 * 1668 * 1669 * [I really think this is EXACTLY the sort of intelligence 1670 * which already resides in sctp_outq. Please move this 1671 * queue and its supporting logic down there. --piggy] 1672 */ 1673 struct list_head addip_chunk_list; 1674 1675 /* ADDIP Section 4.1 ASCONF Chunk Procedures 1676 * 1677 * A2) A serial number should be assigned to the Chunk. The 1678 * serial number SHOULD be a monotonically increasing 1679 * number. The serial number SHOULD be initialized at 1680 * the start of the association to the same value as the 1681 * Initial TSN and every time a new ASCONF chunk is created 1682 * it is incremented by one after assigning the serial number 1683 * to the newly created chunk. 1684 * 1685 * ADDIP 1686 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) 1687 * 1688 * Serial Number : 32 bits (unsigned integer) 1689 * 1690 * This value represents a Serial Number for the ASCONF 1691 * Chunk. The valid range of Serial Number is from 0 to 1692 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 1693 * after reaching 4294967295. 1694 */ 1695 __u32 addip_serial; 1696 1697 /* Need to send an ECNE Chunk? */ 1698 char need_ecne; 1699 1700 /* Is it a temporary association? */ 1701 char temp; 1702 }; 1703 1704 1705 /* An eyecatcher for determining if we are really looking at an 1706 * association data structure. 1707 */ 1708 enum { 1709 SCTP_ASSOC_EYECATCHER = 0xa550c123, 1710 }; 1711 1712 /* Recover the outter association structure. */ 1713 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) 1714 { 1715 struct sctp_association *asoc; 1716 1717 asoc = container_of(base, struct sctp_association, base); 1718 return asoc; 1719 } 1720 1721 /* These are function signatures for manipulating associations. */ 1722 1723 1724 struct sctp_association * 1725 sctp_association_new(const struct sctp_endpoint *, const struct sock *, 1726 sctp_scope_t scope, unsigned int __nocast gfp); 1727 void sctp_association_free(struct sctp_association *); 1728 void sctp_association_put(struct sctp_association *); 1729 void sctp_association_hold(struct sctp_association *); 1730 1731 struct sctp_transport *sctp_assoc_choose_init_transport( 1732 struct sctp_association *); 1733 struct sctp_transport *sctp_assoc_choose_shutdown_transport( 1734 struct sctp_association *); 1735 void sctp_assoc_update_retran_path(struct sctp_association *); 1736 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, 1737 const union sctp_addr *); 1738 int sctp_assoc_lookup_laddr(struct sctp_association *asoc, 1739 const union sctp_addr *laddr); 1740 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, 1741 const union sctp_addr *address, 1742 const unsigned int __nocast gfp, 1743 const int peer_state); 1744 void sctp_assoc_del_peer(struct sctp_association *asoc, 1745 const union sctp_addr *addr); 1746 void sctp_assoc_rm_peer(struct sctp_association *asoc, 1747 struct sctp_transport *peer); 1748 void sctp_assoc_control_transport(struct sctp_association *, 1749 struct sctp_transport *, 1750 sctp_transport_cmd_t, sctp_sn_error_t); 1751 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); 1752 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *, 1753 const union sctp_addr *, 1754 const union sctp_addr *); 1755 void sctp_assoc_migrate(struct sctp_association *, struct sock *); 1756 void sctp_assoc_update(struct sctp_association *old, 1757 struct sctp_association *new); 1758 1759 __u32 sctp_association_get_next_tsn(struct sctp_association *); 1760 1761 void sctp_assoc_sync_pmtu(struct sctp_association *); 1762 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned); 1763 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned); 1764 void sctp_assoc_set_primary(struct sctp_association *, 1765 struct sctp_transport *); 1766 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *, 1767 unsigned int __nocast); 1768 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, 1769 struct sctp_cookie*, 1770 unsigned int __nocast gfp); 1771 1772 int sctp_cmp_addr_exact(const union sctp_addr *ss1, 1773 const union sctp_addr *ss2); 1774 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); 1775 1776 /* A convenience structure to parse out SCTP specific CMSGs. */ 1777 typedef struct sctp_cmsgs { 1778 struct sctp_initmsg *init; 1779 struct sctp_sndrcvinfo *info; 1780 } sctp_cmsgs_t; 1781 1782 /* Structure for tracking memory objects */ 1783 typedef struct { 1784 char *label; 1785 atomic_t *counter; 1786 } sctp_dbg_objcnt_entry_t; 1787 1788 #endif /* __sctp_structs_h__ */ 1789