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 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 281 * the destination address every heartbeat interval. This value 282 * will be inherited by all new associations. 283 */ 284 __u32 hbinterval; 285 286 /* This is the max_retrans value for new associations. */ 287 __u16 pathmaxrxt; 288 289 /* The initial Path MTU to use for new associations. */ 290 __u32 pathmtu; 291 292 /* The default SACK delay timeout for new associations. */ 293 __u32 sackdelay; 294 295 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 296 __u32 param_flags; 297 298 struct sctp_initmsg initmsg; 299 struct sctp_rtoinfo rtoinfo; 300 struct sctp_paddrparams paddrparam; 301 struct sctp_event_subscribe subscribe; 302 struct sctp_assocparams assocparams; 303 int user_frag; 304 __u32 autoclose; 305 __u8 nodelay; 306 __u8 disable_fragments; 307 __u8 pd_mode; 308 __u8 v4mapped; 309 __u32 adaption_ind; 310 311 /* Receive to here while partial delivery is in effect. */ 312 struct sk_buff_head pd_lobby; 313 }; 314 315 static inline struct sctp_sock *sctp_sk(const struct sock *sk) 316 { 317 return (struct sctp_sock *)sk; 318 } 319 320 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp) 321 { 322 return (struct sock *)sp; 323 } 324 325 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 326 struct sctp6_sock { 327 struct sctp_sock sctp; 328 struct ipv6_pinfo inet6; 329 }; 330 #endif /* CONFIG_IPV6 */ 331 332 333 /* This is our APPLICATION-SPECIFIC state cookie. 334 * THIS IS NOT DICTATED BY THE SPECIFICATION. 335 */ 336 /* These are the parts of an association which we send in the cookie. 337 * Most of these are straight out of: 338 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB) 339 * 340 */ 341 342 struct sctp_cookie { 343 344 /* My : Tag expected in every inbound packet and sent 345 * Verification: in the INIT or INIT ACK chunk. 346 * Tag : 347 */ 348 __u32 my_vtag; 349 350 /* Peer's : Tag expected in every outbound packet except 351 * Verification: in the INIT chunk. 352 * Tag : 353 */ 354 __u32 peer_vtag; 355 356 /* The rest of these are not from the spec, but really need to 357 * be in the cookie. 358 */ 359 360 /* My Tie Tag : Assist in discovering a restarting association. */ 361 __u32 my_ttag; 362 363 /* Peer's Tie Tag: Assist in discovering a restarting association. */ 364 __u32 peer_ttag; 365 366 /* When does this cookie expire? */ 367 struct timeval expiration; 368 369 /* Number of inbound/outbound streams which are set 370 * and negotiated during the INIT process. 371 */ 372 __u16 sinit_num_ostreams; 373 __u16 sinit_max_instreams; 374 375 /* This is the first sequence number I used. */ 376 __u32 initial_tsn; 377 378 /* This holds the originating address of the INIT packet. */ 379 union sctp_addr peer_addr; 380 381 /* IG Section 2.35.3 382 * Include the source port of the INIT-ACK 383 */ 384 __u16 my_port; 385 386 __u8 prsctp_capable; 387 388 /* Padding for future use */ 389 __u8 padding; 390 391 __u32 adaption_ind; 392 393 394 /* This is a shim for my peer's INIT packet, followed by 395 * a copy of the raw address list of the association. 396 * The length of the raw address list is saved in the 397 * raw_addr_list_len field, which will be used at the time when 398 * the association TCB is re-constructed from the cookie. 399 */ 400 __u32 raw_addr_list_len; 401 struct sctp_init_chunk peer_init[0]; 402 }; 403 404 405 /* The format of our cookie that we send to our peer. */ 406 struct sctp_signed_cookie { 407 __u8 signature[SCTP_SECRET_SIZE]; 408 struct sctp_cookie c; 409 }; 410 411 /* This is another convenience type to allocate memory for address 412 * params for the maximum size and pass such structures around 413 * internally. 414 */ 415 union sctp_addr_param { 416 struct sctp_ipv4addr_param v4; 417 struct sctp_ipv6addr_param v6; 418 }; 419 420 /* A convenience type to allow walking through the various 421 * parameters and avoid casting all over the place. 422 */ 423 union sctp_params { 424 void *v; 425 struct sctp_paramhdr *p; 426 struct sctp_cookie_preserve_param *life; 427 struct sctp_hostname_param *dns; 428 struct sctp_cookie_param *cookie; 429 struct sctp_supported_addrs_param *sat; 430 struct sctp_ipv4addr_param *v4; 431 struct sctp_ipv6addr_param *v6; 432 union sctp_addr_param *addr; 433 struct sctp_adaption_ind_param *aind; 434 }; 435 436 /* RFC 2960. Section 3.3.5 Heartbeat. 437 * Heartbeat Information: variable length 438 * The Sender-specific Heartbeat Info field should normally include 439 * information about the sender's current time when this HEARTBEAT 440 * chunk is sent and the destination transport address to which this 441 * HEARTBEAT is sent (see Section 8.3). 442 */ 443 typedef struct sctp_sender_hb_info { 444 struct sctp_paramhdr param_hdr; 445 union sctp_addr daddr; 446 unsigned long sent_at; 447 } __attribute__((packed)) sctp_sender_hb_info_t; 448 449 /* 450 * RFC 2960 1.3.2 Sequenced Delivery within Streams 451 * 452 * The term "stream" is used in SCTP to refer to a sequence of user 453 * messages that are to be delivered to the upper-layer protocol in 454 * order with respect to other messages within the same stream. This is 455 * in contrast to its usage in TCP, where it refers to a sequence of 456 * bytes (in this document a byte is assumed to be eight bits). 457 * ... 458 * 459 * This is the structure we use to track both our outbound and inbound 460 * SSN, or Stream Sequence Numbers. 461 */ 462 463 struct sctp_stream { 464 __u16 *ssn; 465 unsigned int len; 466 }; 467 468 struct sctp_ssnmap { 469 struct sctp_stream in; 470 struct sctp_stream out; 471 int malloced; 472 }; 473 474 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, 475 gfp_t gfp); 476 void sctp_ssnmap_free(struct sctp_ssnmap *map); 477 void sctp_ssnmap_clear(struct sctp_ssnmap *map); 478 479 /* What is the current SSN number for this stream? */ 480 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id) 481 { 482 return stream->ssn[id]; 483 } 484 485 /* Return the next SSN number for this stream. */ 486 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id) 487 { 488 return stream->ssn[id]++; 489 } 490 491 /* Skip over this ssn and all below. */ 492 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, 493 __u16 ssn) 494 { 495 stream->ssn[id] = ssn+1; 496 } 497 498 /* 499 * Pointers to address related SCTP functions. 500 * (i.e. things that depend on the address family.) 501 */ 502 struct sctp_af { 503 int (*sctp_xmit) (struct sk_buff *skb, 504 struct sctp_transport *, 505 int ipfragok); 506 int (*setsockopt) (struct sock *sk, 507 int level, 508 int optname, 509 char __user *optval, 510 int optlen); 511 int (*getsockopt) (struct sock *sk, 512 int level, 513 int optname, 514 char __user *optval, 515 int __user *optlen); 516 struct dst_entry *(*get_dst) (struct sctp_association *asoc, 517 union sctp_addr *daddr, 518 union sctp_addr *saddr); 519 void (*get_saddr) (struct sctp_association *asoc, 520 struct dst_entry *dst, 521 union sctp_addr *daddr, 522 union sctp_addr *saddr); 523 void (*copy_addrlist) (struct list_head *, 524 struct net_device *); 525 void (*dst_saddr) (union sctp_addr *saddr, 526 struct dst_entry *dst, 527 unsigned short port); 528 int (*cmp_addr) (const union sctp_addr *addr1, 529 const union sctp_addr *addr2); 530 void (*addr_copy) (union sctp_addr *dst, 531 union sctp_addr *src); 532 void (*from_skb) (union sctp_addr *, 533 struct sk_buff *skb, 534 int saddr); 535 void (*from_sk) (union sctp_addr *, 536 struct sock *sk); 537 void (*to_sk_saddr) (union sctp_addr *, 538 struct sock *sk); 539 void (*to_sk_daddr) (union sctp_addr *, 540 struct sock *sk); 541 void (*from_addr_param) (union sctp_addr *, 542 union sctp_addr_param *, 543 __u16 port, int iif); 544 int (*to_addr_param) (const union sctp_addr *, 545 union sctp_addr_param *); 546 int (*addr_valid) (union sctp_addr *, 547 struct sctp_sock *); 548 sctp_scope_t (*scope) (union sctp_addr *); 549 void (*inaddr_any) (union sctp_addr *, unsigned short); 550 int (*is_any) (const union sctp_addr *); 551 int (*available) (union sctp_addr *, 552 struct sctp_sock *); 553 int (*skb_iif) (const struct sk_buff *sk); 554 int (*is_ce) (const struct sk_buff *sk); 555 void (*seq_dump_addr)(struct seq_file *seq, 556 union sctp_addr *addr); 557 __u16 net_header_len; 558 int sockaddr_len; 559 sa_family_t sa_family; 560 struct list_head list; 561 }; 562 563 struct sctp_af *sctp_get_af_specific(sa_family_t); 564 int sctp_register_af(struct sctp_af *); 565 566 /* Protocol family functions. */ 567 struct sctp_pf { 568 void (*event_msgname)(struct sctp_ulpevent *, char *, int *); 569 void (*skb_msgname) (struct sk_buff *, char *, int *); 570 int (*af_supported) (sa_family_t, struct sctp_sock *); 571 int (*cmp_addr) (const union sctp_addr *, 572 const union sctp_addr *, 573 struct sctp_sock *); 574 int (*bind_verify) (struct sctp_sock *, union sctp_addr *); 575 int (*send_verify) (struct sctp_sock *, union sctp_addr *); 576 int (*supported_addrs)(const struct sctp_sock *, __u16 *); 577 struct sock *(*create_accept_sk) (struct sock *sk, 578 struct sctp_association *asoc); 579 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *); 580 struct sctp_af *af; 581 }; 582 583 584 /* Structure to track chunk fragments that have been acked, but peer 585 * fragments of the same message have not. 586 */ 587 struct sctp_datamsg { 588 /* Chunks waiting to be submitted to lower layer. */ 589 struct list_head chunks; 590 /* Chunks that have been transmitted. */ 591 struct list_head track; 592 /* Reference counting. */ 593 atomic_t refcnt; 594 /* When is this message no longer interesting to the peer? */ 595 unsigned long expires_at; 596 /* Did the messenge fail to send? */ 597 int send_error; 598 char send_failed; 599 /* Control whether chunks from this message can be abandoned. */ 600 char can_abandon; 601 }; 602 603 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, 604 struct sctp_sndrcvinfo *, 605 struct msghdr *, int len); 606 void sctp_datamsg_put(struct sctp_datamsg *); 607 void sctp_datamsg_free(struct sctp_datamsg *); 608 void sctp_datamsg_track(struct sctp_chunk *); 609 void sctp_chunk_fail(struct sctp_chunk *, int error); 610 int sctp_chunk_abandoned(struct sctp_chunk *); 611 612 /* RFC2960 1.4 Key Terms 613 * 614 * o Chunk: A unit of information within an SCTP packet, consisting of 615 * a chunk header and chunk-specific content. 616 * 617 * As a matter of convenience, we remember the SCTP common header for 618 * each chunk as well as a few other header pointers... 619 */ 620 struct sctp_chunk { 621 struct list_head list; 622 623 atomic_t refcnt; 624 625 /* This is our link to the per-transport transmitted list. */ 626 struct list_head transmitted_list; 627 628 /* This field is used by chunks that hold fragmented data. 629 * For the first fragment this is the list that holds the rest of 630 * fragments. For the remaining fragments, this is the link to the 631 * frag_list maintained in the first fragment. 632 */ 633 struct list_head frag_list; 634 635 /* This points to the sk_buff containing the actual data. */ 636 struct sk_buff *skb; 637 638 /* These are the SCTP headers by reverse order in a packet. 639 * Note that some of these may happen more than once. In that 640 * case, we point at the "current" one, whatever that means 641 * for that level of header. 642 */ 643 644 /* We point this at the FIRST TLV parameter to chunk_hdr. */ 645 union sctp_params param_hdr; 646 union { 647 __u8 *v; 648 struct sctp_datahdr *data_hdr; 649 struct sctp_inithdr *init_hdr; 650 struct sctp_sackhdr *sack_hdr; 651 struct sctp_heartbeathdr *hb_hdr; 652 struct sctp_sender_hb_info *hbs_hdr; 653 struct sctp_shutdownhdr *shutdown_hdr; 654 struct sctp_signed_cookie *cookie_hdr; 655 struct sctp_ecnehdr *ecne_hdr; 656 struct sctp_cwrhdr *ecn_cwr_hdr; 657 struct sctp_errhdr *err_hdr; 658 struct sctp_addiphdr *addip_hdr; 659 struct sctp_fwdtsn_hdr *fwdtsn_hdr; 660 } subh; 661 662 __u8 *chunk_end; 663 664 struct sctp_chunkhdr *chunk_hdr; 665 struct sctphdr *sctp_hdr; 666 667 /* This needs to be recoverable for SCTP_SEND_FAILED events. */ 668 struct sctp_sndrcvinfo sinfo; 669 670 /* Which association does this belong to? */ 671 struct sctp_association *asoc; 672 673 /* What endpoint received this chunk? */ 674 struct sctp_ep_common *rcvr; 675 676 /* We fill this in if we are calculating RTT. */ 677 unsigned long sent_at; 678 679 /* What is the origin IP address for this chunk? */ 680 union sctp_addr source; 681 /* Destination address for this chunk. */ 682 union sctp_addr dest; 683 684 /* For outbound message, track all fragments for SEND_FAILED. */ 685 struct sctp_datamsg *msg; 686 687 /* For an inbound chunk, this tells us where it came from. 688 * For an outbound chunk, it tells us where we'd like it to 689 * go. It is NULL if we have no preference. 690 */ 691 struct sctp_transport *transport; 692 693 __u8 rtt_in_progress; /* Is this chunk used for RTT calculation? */ 694 __u8 resent; /* Has this chunk ever been retransmitted. */ 695 __u8 has_tsn; /* Does this chunk have a TSN yet? */ 696 __u8 has_ssn; /* Does this chunk have a SSN yet? */ 697 __u8 singleton; /* Was this the only chunk in the packet? */ 698 __u8 end_of_packet; /* Was this the last chunk in the packet? */ 699 __u8 ecn_ce_done; /* Have we processed the ECN CE bit? */ 700 __u8 pdiscard; /* Discard the whole packet now? */ 701 __u8 tsn_gap_acked; /* Is this chunk acked by a GAP ACK? */ 702 __u8 fast_retransmit; /* Is this chunk fast retransmitted? */ 703 __u8 tsn_missing_report; /* Data chunk missing counter. */ 704 }; 705 706 void sctp_chunk_hold(struct sctp_chunk *); 707 void sctp_chunk_put(struct sctp_chunk *); 708 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 709 struct iovec *data); 710 void sctp_chunk_free(struct sctp_chunk *); 711 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); 712 struct sctp_chunk *sctp_chunkify(struct sk_buff *, 713 const struct sctp_association *, 714 struct sock *); 715 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, 716 union sctp_addr *); 717 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); 718 719 /* This is a structure for holding either an IPv6 or an IPv4 address. */ 720 /* sin_family -- AF_INET or AF_INET6 721 * sin_port -- ordinary port number 722 * sin_addr -- cast to either (struct in_addr) or (struct in6_addr) 723 */ 724 struct sctp_sockaddr_entry { 725 struct list_head list; 726 union sctp_addr a; 727 }; 728 729 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *); 730 731 /* This structure holds lists of chunks as we are assembling for 732 * transmission. 733 */ 734 struct sctp_packet { 735 /* These are the SCTP header values (host order) for the packet. */ 736 __u16 source_port; 737 __u16 destination_port; 738 __u32 vtag; 739 740 /* This contains the payload chunks. */ 741 struct list_head chunk_list; 742 743 /* This is the overhead of the sctp and ip headers. */ 744 size_t overhead; 745 /* This is the total size of all chunks INCLUDING padding. */ 746 size_t size; 747 748 /* The packet is destined for this transport address. 749 * The function we finally use to pass down to the next lower 750 * layer lives in the transport structure. 751 */ 752 struct sctp_transport *transport; 753 754 /* This packet contains a COOKIE-ECHO chunk. */ 755 char has_cookie_echo; 756 757 /* This packet containsa SACK chunk. */ 758 char has_sack; 759 760 /* SCTP cannot fragment this packet. So let ip fragment it. */ 761 char ipfragok; 762 763 int malloced; 764 }; 765 766 struct sctp_packet *sctp_packet_init(struct sctp_packet *, 767 struct sctp_transport *, 768 __u16 sport, __u16 dport); 769 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int); 770 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *, 771 struct sctp_chunk *); 772 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *, 773 struct sctp_chunk *); 774 int sctp_packet_transmit(struct sctp_packet *); 775 void sctp_packet_free(struct sctp_packet *); 776 777 static inline int sctp_packet_empty(struct sctp_packet *packet) 778 { 779 return (packet->size == packet->overhead); 780 } 781 782 /* This represents a remote transport address. 783 * For local transport addresses, we just use union sctp_addr. 784 * 785 * RFC2960 Section 1.4 Key Terms 786 * 787 * o Transport address: A Transport Address is traditionally defined 788 * by Network Layer address, Transport Layer protocol and Transport 789 * Layer port number. In the case of SCTP running over IP, a 790 * transport address is defined by the combination of an IP address 791 * and an SCTP port number (where SCTP is the Transport protocol). 792 * 793 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control 794 * 795 * o The sender keeps a separate congestion control parameter set for 796 * each of the destination addresses it can send to (not each 797 * source-destination pair but for each destination). The parameters 798 * should decay if the address is not used for a long enough time 799 * period. 800 * 801 */ 802 struct sctp_transport { 803 /* A list of transports. */ 804 struct list_head transports; 805 806 /* Reference counting. */ 807 atomic_t refcnt; 808 int dead; 809 810 /* This is the peer's IP address and port. */ 811 union sctp_addr ipaddr; 812 813 /* These are the functions we call to handle LLP stuff. */ 814 struct sctp_af *af_specific; 815 816 /* Which association do we belong to? */ 817 struct sctp_association *asoc; 818 819 /* RFC2960 820 * 821 * 12.3 Per Transport Address Data 822 * 823 * For each destination transport address in the peer's 824 * address list derived from the INIT or INIT ACK chunk, a 825 * number of data elements needs to be maintained including: 826 */ 827 __u32 rtt; /* This is the most recent RTT. */ 828 829 /* RTO : The current retransmission timeout value. */ 830 __u32 rto; 831 832 /* RTTVAR : The current RTT variation. */ 833 __u32 rttvar; 834 835 /* SRTT : The current smoothed round trip time. */ 836 __u32 srtt; 837 838 /* RTO-Pending : A flag used to track if one of the DATA 839 * chunks sent to this address is currently being 840 * used to compute a RTT. If this flag is 0, 841 * the next DATA chunk sent to this destination 842 * should be used to compute a RTT and this flag 843 * should be set. Every time the RTT 844 * calculation completes (i.e. the DATA chunk 845 * is SACK'd) clear this flag. 846 */ 847 int rto_pending; 848 849 /* 850 * These are the congestion stats. 851 */ 852 /* cwnd : The current congestion window. */ 853 __u32 cwnd; /* This is the actual cwnd. */ 854 855 /* ssthresh : The current slow start threshold value. */ 856 __u32 ssthresh; 857 858 /* partial : The tracking method for increase of cwnd when in 859 * bytes acked : congestion avoidance mode (see Section 6.2.2) 860 */ 861 __u32 partial_bytes_acked; 862 863 /* Data that has been sent, but not acknowledged. */ 864 __u32 flight_size; 865 866 /* Destination */ 867 struct dst_entry *dst; 868 /* Source address. */ 869 union sctp_addr saddr; 870 871 /* When was the last time(in jiffies) that a data packet was sent on 872 * this transport? This is used to adjust the cwnd when the transport 873 * becomes inactive. 874 */ 875 unsigned long last_time_used; 876 877 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 878 * the destination address every heartbeat interval. 879 */ 880 __u32 hbinterval; 881 882 /* This is the max_retrans value for the transport and will 883 * be initialized from the assocs value. This can be changed 884 * using SCTP_SET_PEER_ADDR_PARAMS socket option. 885 */ 886 __u16 pathmaxrxt; 887 888 /* PMTU : The current known path MTU. */ 889 __u32 pathmtu; 890 891 /* SACK delay timeout */ 892 __u32 sackdelay; 893 894 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 895 __u32 param_flags; 896 897 /* When was the last time (in jiffies) that we heard from this 898 * transport? We use this to pick new active and retran paths. 899 */ 900 unsigned long last_time_heard; 901 902 /* Last time(in jiffies) when cwnd is reduced due to the congestion 903 * indication based on ECNE chunk. 904 */ 905 unsigned long last_time_ecne_reduced; 906 907 /* The number of times INIT has been sent on this transport. */ 908 int init_sent_count; 909 910 /* state : The current state of this destination, 911 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKOWN. 912 */ 913 int state; 914 915 /* These are the error stats for this destination. */ 916 917 /* Error count : The current error count for this destination. */ 918 unsigned short error_count; 919 920 /* Per : A timer used by each destination. 921 * Destination : 922 * Timer : 923 * 924 * [Everywhere else in the text this is called T3-rtx. -ed] 925 */ 926 struct timer_list T3_rtx_timer; 927 928 /* Heartbeat timer is per destination. */ 929 struct timer_list hb_timer; 930 931 /* Since we're using per-destination retransmission timers 932 * (see above), we're also using per-destination "transmitted" 933 * queues. This probably ought to be a private struct 934 * accessible only within the outqueue, but it's not, yet. 935 */ 936 struct list_head transmitted; 937 938 /* We build bundle-able packets for this transport here. */ 939 struct sctp_packet packet; 940 941 /* This is the list of transports that have chunks to send. */ 942 struct list_head send_ready; 943 944 int malloced; /* Is this structure kfree()able? */ 945 946 /* State information saved for SFR_CACC algorithm. The key 947 * idea in SFR_CACC is to maintain state at the sender on a 948 * per-destination basis when a changeover happens. 949 * char changeover_active; 950 * char cycling_changeover; 951 * __u32 next_tsn_at_change; 952 * char cacc_saw_newack; 953 */ 954 struct { 955 /* An unsigned integer, which stores the next TSN to be 956 * used by the sender, at the moment of changeover. 957 */ 958 __u32 next_tsn_at_change; 959 960 /* A flag which indicates the occurrence of a changeover */ 961 char changeover_active; 962 963 /* A flag which indicates whether the change of primary is 964 * the first switch to this destination address during an 965 * active switch. 966 */ 967 char cycling_changeover; 968 969 /* A temporary flag, which is used during the processing of 970 * a SACK to estimate the causative TSN(s)'s group. 971 */ 972 char cacc_saw_newack; 973 } cacc; 974 }; 975 976 struct sctp_transport *sctp_transport_new(const union sctp_addr *, 977 gfp_t); 978 void sctp_transport_set_owner(struct sctp_transport *, 979 struct sctp_association *); 980 void sctp_transport_route(struct sctp_transport *, union sctp_addr *, 981 struct sctp_sock *); 982 void sctp_transport_pmtu(struct sctp_transport *); 983 void sctp_transport_free(struct sctp_transport *); 984 void sctp_transport_reset_timers(struct sctp_transport *); 985 void sctp_transport_hold(struct sctp_transport *); 986 void sctp_transport_put(struct sctp_transport *); 987 void sctp_transport_update_rto(struct sctp_transport *, __u32); 988 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32); 989 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t); 990 unsigned long sctp_transport_timeout(struct sctp_transport *); 991 992 993 /* This is the structure we use to queue packets as they come into 994 * SCTP. We write packets to it and read chunks from it. 995 */ 996 struct sctp_inq { 997 /* This is actually a queue of sctp_chunk each 998 * containing a partially decoded packet. 999 */ 1000 struct list_head in_chunk_list; 1001 /* This is the packet which is currently off the in queue and is 1002 * being worked on through the inbound chunk processing. 1003 */ 1004 struct sctp_chunk *in_progress; 1005 1006 /* This is the delayed task to finish delivering inbound 1007 * messages. 1008 */ 1009 struct work_struct immediate; 1010 1011 int malloced; /* Is this structure kfree()able? */ 1012 }; 1013 1014 void sctp_inq_init(struct sctp_inq *); 1015 void sctp_inq_free(struct sctp_inq *); 1016 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet); 1017 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *); 1018 void sctp_inq_set_th_handler(struct sctp_inq *, void (*)(void *), void *); 1019 1020 /* This is the structure we use to hold outbound chunks. You push 1021 * chunks in and they automatically pop out the other end as bundled 1022 * packets (it calls (*output_handler)()). 1023 * 1024 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1, 1025 * and 8.2 of the v13 draft. 1026 * 1027 * It handles retransmissions. The connection to the timeout portion 1028 * of the state machine is through sctp_..._timeout() and timeout_handler. 1029 * 1030 * If you feed it SACKs, it will eat them. 1031 * 1032 * If you give it big chunks, it will fragment them. 1033 * 1034 * It assigns TSN's to data chunks. This happens at the last possible 1035 * instant before transmission. 1036 * 1037 * When free()'d, it empties itself out via output_handler(). 1038 */ 1039 struct sctp_outq { 1040 struct sctp_association *asoc; 1041 1042 /* Data pending that has never been transmitted. */ 1043 struct list_head out_chunk_list; 1044 1045 unsigned out_qlen; /* Total length of queued data chunks. */ 1046 1047 /* Error of send failed, may used in SCTP_SEND_FAILED event. */ 1048 unsigned error; 1049 1050 /* These are control chunks we want to send. */ 1051 struct list_head control_chunk_list; 1052 1053 /* These are chunks that have been sacked but are above the 1054 * CTSN, or cumulative tsn ack point. 1055 */ 1056 struct list_head sacked; 1057 1058 /* Put chunks on this list to schedule them for 1059 * retransmission. 1060 */ 1061 struct list_head retransmit; 1062 1063 /* Put chunks on this list to save them for FWD TSN processing as 1064 * they were abandoned. 1065 */ 1066 struct list_head abandoned; 1067 1068 /* How many unackd bytes do we have in-flight? */ 1069 __u32 outstanding_bytes; 1070 1071 /* Corked? */ 1072 char cork; 1073 1074 /* Is this structure empty? */ 1075 char empty; 1076 1077 /* Are we kfree()able? */ 1078 char malloced; 1079 }; 1080 1081 void sctp_outq_init(struct sctp_association *, struct sctp_outq *); 1082 void sctp_outq_teardown(struct sctp_outq *); 1083 void sctp_outq_free(struct sctp_outq*); 1084 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk); 1085 int sctp_outq_flush(struct sctp_outq *, int); 1086 int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *); 1087 int sctp_outq_is_empty(const struct sctp_outq *); 1088 void sctp_outq_restart(struct sctp_outq *); 1089 1090 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *, 1091 sctp_retransmit_reason_t); 1092 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); 1093 int sctp_outq_uncork(struct sctp_outq *); 1094 /* Uncork and flush an outqueue. */ 1095 static inline void sctp_outq_cork(struct sctp_outq *q) 1096 { 1097 q->cork = 1; 1098 } 1099 1100 /* These bind address data fields common between endpoints and associations */ 1101 struct sctp_bind_addr { 1102 1103 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1104 * 1105 * SCTP Port: The local SCTP port number the endpoint is 1106 * bound to. 1107 */ 1108 __u16 port; 1109 1110 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1111 * 1112 * Address List: The list of IP addresses that this instance 1113 * has bound. This information is passed to one's 1114 * peer(s) in INIT and INIT ACK chunks. 1115 */ 1116 struct list_head address_list; 1117 1118 int malloced; /* Are we kfree()able? */ 1119 }; 1120 1121 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port); 1122 void sctp_bind_addr_free(struct sctp_bind_addr *); 1123 int sctp_bind_addr_copy(struct sctp_bind_addr *dest, 1124 const struct sctp_bind_addr *src, 1125 sctp_scope_t scope, gfp_t gfp, 1126 int flags); 1127 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1128 gfp_t gfp); 1129 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *); 1130 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, 1131 struct sctp_sock *); 1132 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 1133 const union sctp_addr *addrs, 1134 int addrcnt, 1135 struct sctp_sock *opt); 1136 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 1137 int *addrs_len, 1138 gfp_t gfp); 1139 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, 1140 __u16 port, gfp_t gfp); 1141 1142 sctp_scope_t sctp_scope(const union sctp_addr *); 1143 int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope); 1144 int sctp_is_any(const union sctp_addr *addr); 1145 int sctp_addr_is_valid(const union sctp_addr *addr); 1146 1147 1148 /* What type of endpoint? */ 1149 typedef enum { 1150 SCTP_EP_TYPE_SOCKET, 1151 SCTP_EP_TYPE_ASSOCIATION, 1152 } sctp_endpoint_type_t; 1153 1154 /* 1155 * A common base class to bridge the implmentation view of a 1156 * socket (usually listening) endpoint versus an association's 1157 * local endpoint. 1158 * This common structure is useful for several purposes: 1159 * 1) Common interface for lookup routines. 1160 * a) Subfunctions work for either endpoint or association 1161 * b) Single interface to lookup allows hiding the lookup lock rather 1162 * than acquiring it externally. 1163 * 2) Common interface for the inbound chunk handling/state machine. 1164 * 3) Common object handling routines for reference counting, etc. 1165 * 4) Disentangle association lookup from endpoint lookup, where we 1166 * do not have to find our endpoint to find our association. 1167 * 1168 */ 1169 1170 struct sctp_ep_common { 1171 /* Fields to help us manage our entries in the hash tables. */ 1172 struct sctp_ep_common *next; 1173 struct sctp_ep_common **pprev; 1174 int hashent; 1175 1176 /* Runtime type information. What kind of endpoint is this? */ 1177 sctp_endpoint_type_t type; 1178 1179 /* Some fields to help us manage this object. 1180 * refcnt - Reference count access to this object. 1181 * dead - Do not attempt to use this object. 1182 * malloced - Do we need to kfree this object? 1183 */ 1184 atomic_t refcnt; 1185 char dead; 1186 char malloced; 1187 1188 /* What socket does this endpoint belong to? */ 1189 struct sock *sk; 1190 1191 /* This is where we receive inbound chunks. */ 1192 struct sctp_inq inqueue; 1193 1194 /* This substructure includes the defining parameters of the 1195 * endpoint: 1196 * bind_addr.port is our shared port number. 1197 * bind_addr.address_list is our set of local IP addresses. 1198 */ 1199 struct sctp_bind_addr bind_addr; 1200 1201 /* Protection during address list comparisons. */ 1202 rwlock_t addr_lock; 1203 }; 1204 1205 1206 /* RFC Section 1.4 Key Terms 1207 * 1208 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a 1209 * multi-homed host, an SCTP endpoint is represented to its peers as a 1210 * combination of a set of eligible destination transport addresses to 1211 * which SCTP packets can be sent and a set of eligible source 1212 * transport addresses from which SCTP packets can be received. 1213 * All transport addresses used by an SCTP endpoint must use the 1214 * same port number, but can use multiple IP addresses. A transport 1215 * address used by an SCTP endpoint must not be used by another 1216 * SCTP endpoint. In other words, a transport address is unique 1217 * to an SCTP endpoint. 1218 * 1219 * From an implementation perspective, each socket has one of these. 1220 * A TCP-style socket will have exactly one association on one of 1221 * these. An UDP-style socket will have multiple associations hanging 1222 * off one of these. 1223 */ 1224 1225 struct sctp_endpoint { 1226 /* Common substructure for endpoint and association. */ 1227 struct sctp_ep_common base; 1228 1229 /* Associations: A list of current associations and mappings 1230 * to the data consumers for each association. This 1231 * may be in the form of a hash table or other 1232 * implementation dependent structure. The data 1233 * consumers may be process identification 1234 * information such as file descriptors, named pipe 1235 * pointer, or table pointers dependent on how SCTP 1236 * is implemented. 1237 */ 1238 /* This is really a list of struct sctp_association entries. */ 1239 struct list_head asocs; 1240 1241 /* Secret Key: A secret key used by this endpoint to compute 1242 * the MAC. This SHOULD be a cryptographic quality 1243 * random number with a sufficient length. 1244 * Discussion in [RFC1750] can be helpful in 1245 * selection of the key. 1246 */ 1247 __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE]; 1248 int current_key; 1249 int last_key; 1250 int key_changed_at; 1251 1252 /* sendbuf acct. policy. */ 1253 __u32 sndbuf_policy; 1254 1255 /* rcvbuf acct. policy. */ 1256 __u32 rcvbuf_policy; 1257 }; 1258 1259 /* Recover the outter endpoint structure. */ 1260 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) 1261 { 1262 struct sctp_endpoint *ep; 1263 1264 ep = container_of(base, struct sctp_endpoint, base); 1265 return ep; 1266 } 1267 1268 /* These are function signatures for manipulating endpoints. */ 1269 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t); 1270 void sctp_endpoint_free(struct sctp_endpoint *); 1271 void sctp_endpoint_put(struct sctp_endpoint *); 1272 void sctp_endpoint_hold(struct sctp_endpoint *); 1273 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); 1274 struct sctp_association *sctp_endpoint_lookup_assoc( 1275 const struct sctp_endpoint *ep, 1276 const union sctp_addr *paddr, 1277 struct sctp_transport **); 1278 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *, 1279 const union sctp_addr *); 1280 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *, 1281 const union sctp_addr *); 1282 int sctp_has_association(const union sctp_addr *laddr, 1283 const union sctp_addr *paddr); 1284 1285 int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t, 1286 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk, 1287 struct sctp_chunk **err_chunk); 1288 int sctp_process_init(struct sctp_association *, sctp_cid_t cid, 1289 const union sctp_addr *peer, 1290 sctp_init_chunk_t *init, gfp_t gfp); 1291 __u32 sctp_generate_tag(const struct sctp_endpoint *); 1292 __u32 sctp_generate_tsn(const struct sctp_endpoint *); 1293 1294 1295 /* RFC2960 1296 * 1297 * 12. Recommended Transmission Control Block (TCB) Parameters 1298 * 1299 * This section details a recommended set of parameters that should 1300 * be contained within the TCB for an implementation. This section is 1301 * for illustrative purposes and should not be deemed as requirements 1302 * on an implementation or as an exhaustive list of all parameters 1303 * inside an SCTP TCB. Each implementation may need its own additional 1304 * parameters for optimization. 1305 */ 1306 1307 1308 /* Here we have information about each individual association. */ 1309 struct sctp_association { 1310 1311 /* A base structure common to endpoint and association. 1312 * In this context, it represents the associations's view 1313 * of the local endpoint of the association. 1314 */ 1315 struct sctp_ep_common base; 1316 1317 /* Associations on the same socket. */ 1318 struct list_head asocs; 1319 1320 /* association id. */ 1321 sctp_assoc_t assoc_id; 1322 1323 /* This is our parent endpoint. */ 1324 struct sctp_endpoint *ep; 1325 1326 /* These are those association elements needed in the cookie. */ 1327 struct sctp_cookie c; 1328 1329 /* This is all information about our peer. */ 1330 struct { 1331 /* rwnd 1332 * 1333 * Peer Rwnd : Current calculated value of the peer's rwnd. 1334 */ 1335 __u32 rwnd; 1336 1337 /* transport_addr_list 1338 * 1339 * Peer : A list of SCTP transport addresses that the 1340 * Transport : peer is bound to. This information is derived 1341 * Address : from the INIT or INIT ACK and is used to 1342 * List : associate an inbound packet with a given 1343 * : association. Normally this information is 1344 * : hashed or keyed for quick lookup and access 1345 * : of the TCB. 1346 * : The list is also initialized with the list 1347 * : of addresses passed with the sctp_connectx() 1348 * : call. 1349 * 1350 * It is a list of SCTP_transport's. 1351 */ 1352 struct list_head transport_addr_list; 1353 1354 /* transport_count 1355 * 1356 * Peer : A count of the number of peer addresses 1357 * Transport : in the Peer Transport Address List. 1358 * Address : 1359 * Count : 1360 */ 1361 __u16 transport_count; 1362 1363 /* port 1364 * The transport layer port number. 1365 */ 1366 __u16 port; 1367 1368 /* primary_path 1369 * 1370 * Primary : This is the current primary destination 1371 * Path : transport address of the peer endpoint. It 1372 * : may also specify a source transport address 1373 * : on this endpoint. 1374 * 1375 * All of these paths live on transport_addr_list. 1376 * 1377 * At the bakeoffs, we discovered that the intent of 1378 * primaryPath is that it only changes when the ULP 1379 * asks to have it changed. We add the activePath to 1380 * designate the connection we are currently using to 1381 * transmit new data and most control chunks. 1382 */ 1383 struct sctp_transport *primary_path; 1384 1385 /* Cache the primary path address here, when we 1386 * need a an address for msg_name. 1387 */ 1388 union sctp_addr primary_addr; 1389 1390 /* active_path 1391 * The path that we are currently using to 1392 * transmit new data and most control chunks. 1393 */ 1394 struct sctp_transport *active_path; 1395 1396 /* retran_path 1397 * 1398 * RFC2960 6.4 Multi-homed SCTP Endpoints 1399 * ... 1400 * Furthermore, when its peer is multi-homed, an 1401 * endpoint SHOULD try to retransmit a chunk to an 1402 * active destination transport address that is 1403 * different from the last destination address to 1404 * which the DATA chunk was sent. 1405 */ 1406 struct sctp_transport *retran_path; 1407 1408 /* Pointer to last transport I have sent on. */ 1409 struct sctp_transport *last_sent_to; 1410 1411 /* This is the last transport I have received DATA on. */ 1412 struct sctp_transport *last_data_from; 1413 1414 /* 1415 * Mapping An array of bits or bytes indicating which out of 1416 * Array order TSN's have been received (relative to the 1417 * Last Rcvd TSN). If no gaps exist, i.e. no out of 1418 * order packets have been received, this array 1419 * will be set to all zero. This structure may be 1420 * in the form of a circular buffer or bit array. 1421 * 1422 * Last Rcvd : This is the last TSN received in 1423 * TSN : sequence. This value is set initially by 1424 * : taking the peer's Initial TSN, received in 1425 * : the INIT or INIT ACK chunk, and subtracting 1426 * : one from it. 1427 * 1428 * Throughout most of the specification this is called the 1429 * "Cumulative TSN ACK Point". In this case, we 1430 * ignore the advice in 12.2 in favour of the term 1431 * used in the bulk of the text. This value is hidden 1432 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). 1433 */ 1434 struct sctp_tsnmap tsn_map; 1435 __u8 _map[sctp_tsnmap_storage_size(SCTP_TSN_MAP_SIZE)]; 1436 1437 /* Ack State : This flag indicates if the next received 1438 * : packet is to be responded to with a 1439 * : SACK. This is initializedto 0. When a packet 1440 * : is received it is incremented. If this value 1441 * : reaches 2 or more, a SACK is sent and the 1442 * : value is reset to 0. Note: This is used only 1443 * : when no DATA chunks are received out of 1444 * : order. When DATA chunks are out of order, 1445 * : SACK's are not delayed (see Section 6). 1446 */ 1447 __u8 sack_needed; /* Do we need to sack the peer? */ 1448 1449 /* These are capabilities which our peer advertised. */ 1450 __u8 ecn_capable; /* Can peer do ECN? */ 1451 __u8 ipv4_address; /* Peer understands IPv4 addresses? */ 1452 __u8 ipv6_address; /* Peer understands IPv6 addresses? */ 1453 __u8 hostname_address;/* Peer understands DNS addresses? */ 1454 __u8 asconf_capable; /* Does peer support ADDIP? */ 1455 __u8 prsctp_capable; /* Can peer do PR-SCTP? */ 1456 1457 __u32 adaption_ind; /* Adaption Code point. */ 1458 1459 /* This mask is used to disable sending the ASCONF chunk 1460 * with specified parameter to peer. 1461 */ 1462 __u16 addip_disabled_mask; 1463 1464 struct sctp_inithdr i; 1465 int cookie_len; 1466 void *cookie; 1467 1468 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1469 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the 1470 * Initial TSN Value minus 1 1471 */ 1472 __u32 addip_serial; 1473 } peer; 1474 1475 /* State : A state variable indicating what state the 1476 * : association is in, i.e. COOKIE-WAIT, 1477 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, 1478 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. 1479 * 1480 * Note: No "CLOSED" state is illustrated since if a 1481 * association is "CLOSED" its TCB SHOULD be removed. 1482 * 1483 * In this implementation we DO have a CLOSED 1484 * state which is used during initiation and shutdown. 1485 * 1486 * State takes values from SCTP_STATE_*. 1487 */ 1488 sctp_state_t state; 1489 1490 /* The cookie life I award for any cookie. */ 1491 struct timeval cookie_life; 1492 1493 /* Overall : The overall association error count. 1494 * Error Count : [Clear this any time I get something.] 1495 */ 1496 int overall_error_count; 1497 1498 /* These are the association's initial, max, and min RTO values. 1499 * These values will be initialized by system defaults, but can 1500 * be modified via the SCTP_RTOINFO socket option. 1501 */ 1502 __u32 rto_initial; 1503 __u32 rto_max; 1504 __u32 rto_min; 1505 1506 /* Maximum number of new data packets that can be sent in a burst. */ 1507 int max_burst; 1508 1509 /* This is the max_retrans value for the association. This value will 1510 * be initialized initialized from system defaults, but can be 1511 * modified by the SCTP_ASSOCINFO socket option. 1512 */ 1513 int max_retrans; 1514 1515 /* Maximum number of times the endpoint will retransmit INIT */ 1516 __u16 max_init_attempts; 1517 1518 /* How many times have we resent an INIT? */ 1519 __u16 init_retries; 1520 1521 /* The largest timeout or RTO value to use in attempting an INIT */ 1522 __u16 max_init_timeo; 1523 1524 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 1525 * the destination address every heartbeat interval. This value 1526 * will be inherited by all new transports. 1527 */ 1528 __u32 hbinterval; 1529 1530 /* This is the max_retrans value for new transports in the 1531 * association. 1532 */ 1533 __u16 pathmaxrxt; 1534 1535 /* Association : The smallest PMTU discovered for all of the 1536 * PMTU : peer's transport addresses. 1537 */ 1538 __u32 pathmtu; 1539 1540 /* SACK delay timeout */ 1541 __u32 sackdelay; 1542 1543 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 1544 __u32 param_flags; 1545 1546 int timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1547 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; 1548 1549 /* Transport to which SHUTDOWN chunk was last sent. */ 1550 struct sctp_transport *shutdown_last_sent_to; 1551 1552 /* Transport to which INIT chunk was last sent. */ 1553 struct sctp_transport *init_last_sent_to; 1554 1555 /* Next TSN : The next TSN number to be assigned to a new 1556 * : DATA chunk. This is sent in the INIT or INIT 1557 * : ACK chunk to the peer and incremented each 1558 * : time a DATA chunk is assigned a TSN 1559 * : (normally just prior to transmit or during 1560 * : fragmentation). 1561 */ 1562 __u32 next_tsn; 1563 1564 /* 1565 * Last Rcvd : This is the last TSN received in sequence. This value 1566 * TSN : is set initially by taking the peer's Initial TSN, 1567 * : received in the INIT or INIT ACK chunk, and 1568 * : subtracting one from it. 1569 * 1570 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. 1571 */ 1572 1573 __u32 ctsn_ack_point; 1574 1575 /* PR-SCTP Advanced.Peer.Ack.Point */ 1576 __u32 adv_peer_ack_point; 1577 1578 /* Highest TSN that is acknowledged by incoming SACKs. */ 1579 __u32 highest_sacked; 1580 1581 /* The number of unacknowledged data chunks. Reported through 1582 * the SCTP_STATUS sockopt. 1583 */ 1584 __u16 unack_data; 1585 1586 /* This is the association's receive buffer space. This value is used 1587 * to set a_rwnd field in an INIT or a SACK chunk. 1588 */ 1589 __u32 rwnd; 1590 1591 /* This is the last advertised value of rwnd over a SACK chunk. */ 1592 __u32 a_rwnd; 1593 1594 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed 1595 * to slop over a maximum of the association's frag_point. 1596 */ 1597 __u32 rwnd_over; 1598 1599 /* This is the sndbuf size in use for the association. 1600 * This corresponds to the sndbuf size for the association, 1601 * as specified in the sk->sndbuf. 1602 */ 1603 int sndbuf_used; 1604 1605 /* This is the amount of memory that this association has allocated 1606 * in the receive path at any given time. 1607 */ 1608 atomic_t rmem_alloc; 1609 1610 /* This is the wait queue head for send requests waiting on 1611 * the association sndbuf space. 1612 */ 1613 wait_queue_head_t wait; 1614 1615 /* The message size at which SCTP fragmentation will occur. */ 1616 __u32 frag_point; 1617 1618 /* Counter used to count INIT errors. */ 1619 int init_err_counter; 1620 1621 /* Count the number of INIT cycles (for doubling timeout). */ 1622 int init_cycle; 1623 1624 /* Default send parameters. */ 1625 __u16 default_stream; 1626 __u16 default_flags; 1627 __u32 default_ppid; 1628 __u32 default_context; 1629 __u32 default_timetolive; 1630 1631 /* This tracks outbound ssn for a given stream. */ 1632 struct sctp_ssnmap *ssnmap; 1633 1634 /* All outbound chunks go through this structure. */ 1635 struct sctp_outq outqueue; 1636 1637 /* A smart pipe that will handle reordering and fragmentation, 1638 * as well as handle passing events up to the ULP. 1639 */ 1640 struct sctp_ulpq ulpq; 1641 1642 /* Last TSN that caused an ECNE Chunk to be sent. */ 1643 __u32 last_ecne_tsn; 1644 1645 /* Last TSN that caused a CWR Chunk to be sent. */ 1646 __u32 last_cwr_tsn; 1647 1648 /* How many duplicated TSNs have we seen? */ 1649 int numduptsns; 1650 1651 /* Number of seconds of idle time before an association is closed. */ 1652 __u32 autoclose; 1653 1654 /* These are to support 1655 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses 1656 * and Enforcement of Flow and Message Limits" 1657 * <draft-ietf-tsvwg-addip-sctp-02.txt> 1658 * or "ADDIP" for short. 1659 */ 1660 1661 1662 1663 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1664 * 1665 * R1) One and only one ASCONF Chunk MAY be in transit and 1666 * unacknowledged at any one time. If a sender, after sending 1667 * an ASCONF chunk, decides it needs to transfer another 1668 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1669 * returns from the previous ASCONF Chunk before sending a 1670 * subsequent ASCONF. Note this restriction binds each side, 1671 * so at any time two ASCONF may be in-transit on any given 1672 * association (one sent from each endpoint). 1673 * 1674 * [This is our one-and-only-one ASCONF in flight. If we do 1675 * not have an ASCONF in flight, this is NULL.] 1676 */ 1677 struct sctp_chunk *addip_last_asconf; 1678 1679 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1680 * 1681 * IMPLEMENTATION NOTE: As an optimization a receiver may wish 1682 * to save the last ASCONF-ACK for some predetermined period 1683 * of time and instead of re-processing the ASCONF (with the 1684 * same serial number) it may just re-transmit the 1685 * ASCONF-ACK. It may wish to use the arrival of a new serial 1686 * number to discard the previously saved ASCONF-ACK or any 1687 * other means it may choose to expire the saved ASCONF-ACK. 1688 * 1689 * [This is our saved ASCONF-ACK. We invalidate it when a new 1690 * ASCONF serial number arrives.] 1691 */ 1692 struct sctp_chunk *addip_last_asconf_ack; 1693 1694 /* These ASCONF chunks are waiting to be sent. 1695 * 1696 * These chunaks can't be pushed to outqueue until receiving 1697 * ASCONF_ACK for the previous ASCONF indicated by 1698 * addip_last_asconf, so as to guarantee that only one ASCONF 1699 * is in flight at any time. 1700 * 1701 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1702 * 1703 * In defining the ASCONF Chunk transfer procedures, it is 1704 * essential that these transfers MUST NOT cause congestion 1705 * within the network. To achieve this, we place these 1706 * restrictions on the transfer of ASCONF Chunks: 1707 * 1708 * R1) One and only one ASCONF Chunk MAY be in transit and 1709 * unacknowledged at any one time. If a sender, after sending 1710 * an ASCONF chunk, decides it needs to transfer another 1711 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1712 * returns from the previous ASCONF Chunk before sending a 1713 * subsequent ASCONF. Note this restriction binds each side, 1714 * so at any time two ASCONF may be in-transit on any given 1715 * association (one sent from each endpoint). 1716 * 1717 * 1718 * [I really think this is EXACTLY the sort of intelligence 1719 * which already resides in sctp_outq. Please move this 1720 * queue and its supporting logic down there. --piggy] 1721 */ 1722 struct list_head addip_chunk_list; 1723 1724 /* ADDIP Section 4.1 ASCONF Chunk Procedures 1725 * 1726 * A2) A serial number should be assigned to the Chunk. The 1727 * serial number SHOULD be a monotonically increasing 1728 * number. The serial number SHOULD be initialized at 1729 * the start of the association to the same value as the 1730 * Initial TSN and every time a new ASCONF chunk is created 1731 * it is incremented by one after assigning the serial number 1732 * to the newly created chunk. 1733 * 1734 * ADDIP 1735 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) 1736 * 1737 * Serial Number : 32 bits (unsigned integer) 1738 * 1739 * This value represents a Serial Number for the ASCONF 1740 * Chunk. The valid range of Serial Number is from 0 to 1741 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 1742 * after reaching 4294967295. 1743 */ 1744 __u32 addip_serial; 1745 1746 /* Need to send an ECNE Chunk? */ 1747 char need_ecne; 1748 1749 /* Is it a temporary association? */ 1750 char temp; 1751 }; 1752 1753 1754 /* An eyecatcher for determining if we are really looking at an 1755 * association data structure. 1756 */ 1757 enum { 1758 SCTP_ASSOC_EYECATCHER = 0xa550c123, 1759 }; 1760 1761 /* Recover the outter association structure. */ 1762 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) 1763 { 1764 struct sctp_association *asoc; 1765 1766 asoc = container_of(base, struct sctp_association, base); 1767 return asoc; 1768 } 1769 1770 /* These are function signatures for manipulating associations. */ 1771 1772 1773 struct sctp_association * 1774 sctp_association_new(const struct sctp_endpoint *, const struct sock *, 1775 sctp_scope_t scope, gfp_t gfp); 1776 void sctp_association_free(struct sctp_association *); 1777 void sctp_association_put(struct sctp_association *); 1778 void sctp_association_hold(struct sctp_association *); 1779 1780 struct sctp_transport *sctp_assoc_choose_init_transport( 1781 struct sctp_association *); 1782 struct sctp_transport *sctp_assoc_choose_shutdown_transport( 1783 struct sctp_association *); 1784 void sctp_assoc_update_retran_path(struct sctp_association *); 1785 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, 1786 const union sctp_addr *); 1787 int sctp_assoc_lookup_laddr(struct sctp_association *asoc, 1788 const union sctp_addr *laddr); 1789 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, 1790 const union sctp_addr *address, 1791 const gfp_t gfp, 1792 const int peer_state); 1793 void sctp_assoc_del_peer(struct sctp_association *asoc, 1794 const union sctp_addr *addr); 1795 void sctp_assoc_rm_peer(struct sctp_association *asoc, 1796 struct sctp_transport *peer); 1797 void sctp_assoc_control_transport(struct sctp_association *, 1798 struct sctp_transport *, 1799 sctp_transport_cmd_t, sctp_sn_error_t); 1800 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); 1801 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *, 1802 const union sctp_addr *, 1803 const union sctp_addr *); 1804 void sctp_assoc_migrate(struct sctp_association *, struct sock *); 1805 void sctp_assoc_update(struct sctp_association *old, 1806 struct sctp_association *new); 1807 1808 __u32 sctp_association_get_next_tsn(struct sctp_association *); 1809 1810 void sctp_assoc_sync_pmtu(struct sctp_association *); 1811 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned); 1812 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned); 1813 void sctp_assoc_set_primary(struct sctp_association *, 1814 struct sctp_transport *); 1815 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *, 1816 gfp_t); 1817 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, 1818 struct sctp_cookie*, 1819 gfp_t gfp); 1820 1821 int sctp_cmp_addr_exact(const union sctp_addr *ss1, 1822 const union sctp_addr *ss2); 1823 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); 1824 1825 /* A convenience structure to parse out SCTP specific CMSGs. */ 1826 typedef struct sctp_cmsgs { 1827 struct sctp_initmsg *init; 1828 struct sctp_sndrcvinfo *info; 1829 } sctp_cmsgs_t; 1830 1831 /* Structure for tracking memory objects */ 1832 typedef struct { 1833 char *label; 1834 atomic_t *counter; 1835 } sctp_dbg_objcnt_entry_t; 1836 1837 #endif /* __sctp_structs_h__ */ 1838