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 struct crypto_hash; 91 92 93 #include <net/sctp/tsnmap.h> 94 #include <net/sctp/ulpevent.h> 95 #include <net/sctp/ulpqueue.h> 96 97 /* Structures useful for managing bind/connect. */ 98 99 struct sctp_bind_bucket { 100 unsigned short port; 101 unsigned short fastreuse; 102 struct sctp_bind_bucket *next; 103 struct sctp_bind_bucket **pprev; 104 struct hlist_head owner; 105 }; 106 107 struct sctp_bind_hashbucket { 108 spinlock_t lock; 109 struct sctp_bind_bucket *chain; 110 }; 111 112 /* Used for hashing all associations. */ 113 struct sctp_hashbucket { 114 rwlock_t lock; 115 struct sctp_ep_common *chain; 116 } __attribute__((__aligned__(8))); 117 118 119 /* The SCTP globals structure. */ 120 extern struct sctp_globals { 121 /* RFC2960 Section 14. Suggested SCTP Protocol Parameter Values 122 * 123 * The following protocol parameters are RECOMMENDED: 124 * 125 * RTO.Initial - 3 seconds 126 * RTO.Min - 1 second 127 * RTO.Max - 60 seconds 128 * RTO.Alpha - 1/8 (3 when converted to right shifts.) 129 * RTO.Beta - 1/4 (2 when converted to right shifts.) 130 */ 131 unsigned int rto_initial; 132 unsigned int rto_min; 133 unsigned int rto_max; 134 135 /* Note: rto_alpha and rto_beta are really defined as inverse 136 * powers of two to facilitate integer operations. 137 */ 138 int rto_alpha; 139 int rto_beta; 140 141 /* Max.Burst - 4 */ 142 int max_burst; 143 144 /* Whether Cookie Preservative is enabled(1) or not(0) */ 145 int cookie_preserve_enable; 146 147 /* Valid.Cookie.Life - 60 seconds */ 148 unsigned int valid_cookie_life; 149 150 /* Delayed SACK timeout 200ms default*/ 151 unsigned int sack_timeout; 152 153 /* HB.interval - 30 seconds */ 154 unsigned int hb_interval; 155 156 /* Association.Max.Retrans - 10 attempts 157 * Path.Max.Retrans - 5 attempts (per destination address) 158 * Max.Init.Retransmits - 8 attempts 159 */ 160 int max_retrans_association; 161 int max_retrans_path; 162 int max_retrans_init; 163 164 /* 165 * Policy for preforming sctp/socket accounting 166 * 0 - do socket level accounting, all assocs share sk_sndbuf 167 * 1 - do sctp accounting, each asoc may use sk_sndbuf bytes 168 */ 169 int sndbuf_policy; 170 171 /* 172 * Policy for preforming sctp/socket accounting 173 * 0 - do socket level accounting, all assocs share sk_rcvbuf 174 * 1 - do sctp accounting, each asoc may use sk_rcvbuf bytes 175 */ 176 int rcvbuf_policy; 177 178 /* The following variables are implementation specific. */ 179 180 /* Default initialization values to be applied to new associations. */ 181 __u16 max_instreams; 182 __u16 max_outstreams; 183 184 /* This is a list of groups of functions for each address 185 * family that we support. 186 */ 187 struct list_head address_families; 188 189 /* This is the hash of all endpoints. */ 190 int ep_hashsize; 191 struct sctp_hashbucket *ep_hashtable; 192 193 /* This is the hash of all associations. */ 194 int assoc_hashsize; 195 struct sctp_hashbucket *assoc_hashtable; 196 197 /* This is the sctp port control hash. */ 198 int port_hashsize; 199 int port_rover; 200 spinlock_t port_alloc_lock; /* Protects port_rover. */ 201 struct sctp_bind_hashbucket *port_hashtable; 202 203 /* This is the global local address list. 204 * We actively maintain this complete list of addresses on 205 * the system by catching address add/delete events. 206 * 207 * It is a list of sctp_sockaddr_entry. 208 */ 209 struct list_head local_addr_list; 210 211 /* Flag to indicate if addip is enabled. */ 212 int addip_enable; 213 214 /* Flag to indicate if PR-SCTP is enabled. */ 215 int prsctp_enable; 216 } sctp_globals; 217 218 #define sctp_rto_initial (sctp_globals.rto_initial) 219 #define sctp_rto_min (sctp_globals.rto_min) 220 #define sctp_rto_max (sctp_globals.rto_max) 221 #define sctp_rto_alpha (sctp_globals.rto_alpha) 222 #define sctp_rto_beta (sctp_globals.rto_beta) 223 #define sctp_max_burst (sctp_globals.max_burst) 224 #define sctp_valid_cookie_life (sctp_globals.valid_cookie_life) 225 #define sctp_cookie_preserve_enable (sctp_globals.cookie_preserve_enable) 226 #define sctp_max_retrans_association (sctp_globals.max_retrans_association) 227 #define sctp_sndbuf_policy (sctp_globals.sndbuf_policy) 228 #define sctp_rcvbuf_policy (sctp_globals.rcvbuf_policy) 229 #define sctp_max_retrans_path (sctp_globals.max_retrans_path) 230 #define sctp_max_retrans_init (sctp_globals.max_retrans_init) 231 #define sctp_sack_timeout (sctp_globals.sack_timeout) 232 #define sctp_hb_interval (sctp_globals.hb_interval) 233 #define sctp_max_instreams (sctp_globals.max_instreams) 234 #define sctp_max_outstreams (sctp_globals.max_outstreams) 235 #define sctp_address_families (sctp_globals.address_families) 236 #define sctp_ep_hashsize (sctp_globals.ep_hashsize) 237 #define sctp_ep_hashtable (sctp_globals.ep_hashtable) 238 #define sctp_assoc_hashsize (sctp_globals.assoc_hashsize) 239 #define sctp_assoc_hashtable (sctp_globals.assoc_hashtable) 240 #define sctp_port_hashsize (sctp_globals.port_hashsize) 241 #define sctp_port_rover (sctp_globals.port_rover) 242 #define sctp_port_alloc_lock (sctp_globals.port_alloc_lock) 243 #define sctp_port_hashtable (sctp_globals.port_hashtable) 244 #define sctp_local_addr_list (sctp_globals.local_addr_list) 245 #define sctp_addip_enable (sctp_globals.addip_enable) 246 #define sctp_prsctp_enable (sctp_globals.prsctp_enable) 247 248 /* SCTP Socket type: UDP or TCP style. */ 249 typedef enum { 250 SCTP_SOCKET_UDP = 0, 251 SCTP_SOCKET_UDP_HIGH_BANDWIDTH, 252 SCTP_SOCKET_TCP 253 } sctp_socket_type_t; 254 255 /* Per socket SCTP information. */ 256 struct sctp_sock { 257 /* inet_sock has to be the first member of sctp_sock */ 258 struct inet_sock inet; 259 /* What kind of a socket is this? */ 260 sctp_socket_type_t type; 261 262 /* PF_ family specific functions. */ 263 struct sctp_pf *pf; 264 265 /* Access to HMAC transform. */ 266 struct crypto_hash *hmac; 267 268 /* What is our base endpointer? */ 269 struct sctp_endpoint *ep; 270 271 struct sctp_bind_bucket *bind_hash; 272 /* Various Socket Options. */ 273 __u16 default_stream; 274 __u32 default_ppid; 275 __u16 default_flags; 276 __u32 default_context; 277 __u32 default_timetolive; 278 __u32 default_rcv_context; 279 int max_burst; 280 281 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 282 * the destination address every heartbeat interval. This value 283 * will be inherited by all new associations. 284 */ 285 __u32 hbinterval; 286 287 /* This is the max_retrans value for new associations. */ 288 __u16 pathmaxrxt; 289 290 /* The initial Path MTU to use for new associations. */ 291 __u32 pathmtu; 292 293 /* The default SACK delay timeout for new associations. */ 294 __u32 sackdelay; 295 296 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 297 __u32 param_flags; 298 299 struct sctp_initmsg initmsg; 300 struct sctp_rtoinfo rtoinfo; 301 struct sctp_paddrparams paddrparam; 302 struct sctp_event_subscribe subscribe; 303 struct sctp_assocparams assocparams; 304 int user_frag; 305 __u32 autoclose; 306 __u8 nodelay; 307 __u8 disable_fragments; 308 __u8 v4mapped; 309 __u8 frag_interleave; 310 __u32 adaptation_ind; 311 __u32 pd_point; 312 313 atomic_t pd_mode; 314 /* Receive to here while partial delivery is in effect. */ 315 struct sk_buff_head pd_lobby; 316 }; 317 318 static inline struct sctp_sock *sctp_sk(const struct sock *sk) 319 { 320 return (struct sctp_sock *)sk; 321 } 322 323 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp) 324 { 325 return (struct sock *)sp; 326 } 327 328 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 329 struct sctp6_sock { 330 struct sctp_sock sctp; 331 struct ipv6_pinfo inet6; 332 }; 333 #endif /* CONFIG_IPV6 */ 334 335 336 /* This is our APPLICATION-SPECIFIC state cookie. 337 * THIS IS NOT DICTATED BY THE SPECIFICATION. 338 */ 339 /* These are the parts of an association which we send in the cookie. 340 * Most of these are straight out of: 341 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB) 342 * 343 */ 344 345 struct sctp_cookie { 346 347 /* My : Tag expected in every inbound packet and sent 348 * Verification: in the INIT or INIT ACK chunk. 349 * Tag : 350 */ 351 __u32 my_vtag; 352 353 /* Peer's : Tag expected in every outbound packet except 354 * Verification: in the INIT chunk. 355 * Tag : 356 */ 357 __u32 peer_vtag; 358 359 /* The rest of these are not from the spec, but really need to 360 * be in the cookie. 361 */ 362 363 /* My Tie Tag : Assist in discovering a restarting association. */ 364 __u32 my_ttag; 365 366 /* Peer's Tie Tag: Assist in discovering a restarting association. */ 367 __u32 peer_ttag; 368 369 /* When does this cookie expire? */ 370 struct timeval expiration; 371 372 /* Number of inbound/outbound streams which are set 373 * and negotiated during the INIT process. 374 */ 375 __u16 sinit_num_ostreams; 376 __u16 sinit_max_instreams; 377 378 /* This is the first sequence number I used. */ 379 __u32 initial_tsn; 380 381 /* This holds the originating address of the INIT packet. */ 382 union sctp_addr peer_addr; 383 384 /* IG Section 2.35.3 385 * Include the source port of the INIT-ACK 386 */ 387 __u16 my_port; 388 389 __u8 prsctp_capable; 390 391 /* Padding for future use */ 392 __u8 padding; 393 394 __u32 adaptation_ind; 395 396 397 /* This is a shim for my peer's INIT packet, followed by 398 * a copy of the raw address list of the association. 399 * The length of the raw address list is saved in the 400 * raw_addr_list_len field, which will be used at the time when 401 * the association TCB is re-constructed from the cookie. 402 */ 403 __u32 raw_addr_list_len; 404 struct sctp_init_chunk peer_init[0]; 405 }; 406 407 408 /* The format of our cookie that we send to our peer. */ 409 struct sctp_signed_cookie { 410 __u8 signature[SCTP_SECRET_SIZE]; 411 __u32 __pad; /* force sctp_cookie alignment to 64 bits */ 412 struct sctp_cookie c; 413 } __attribute__((packed)); 414 415 /* This is another convenience type to allocate memory for address 416 * params for the maximum size and pass such structures around 417 * internally. 418 */ 419 union sctp_addr_param { 420 struct sctp_ipv4addr_param v4; 421 struct sctp_ipv6addr_param v6; 422 }; 423 424 /* A convenience type to allow walking through the various 425 * parameters and avoid casting all over the place. 426 */ 427 union sctp_params { 428 void *v; 429 struct sctp_paramhdr *p; 430 struct sctp_cookie_preserve_param *life; 431 struct sctp_hostname_param *dns; 432 struct sctp_cookie_param *cookie; 433 struct sctp_supported_addrs_param *sat; 434 struct sctp_ipv4addr_param *v4; 435 struct sctp_ipv6addr_param *v6; 436 union sctp_addr_param *addr; 437 struct sctp_adaptation_ind_param *aind; 438 }; 439 440 /* RFC 2960. Section 3.3.5 Heartbeat. 441 * Heartbeat Information: variable length 442 * The Sender-specific Heartbeat Info field should normally include 443 * information about the sender's current time when this HEARTBEAT 444 * chunk is sent and the destination transport address to which this 445 * HEARTBEAT is sent (see Section 8.3). 446 */ 447 typedef struct sctp_sender_hb_info { 448 struct sctp_paramhdr param_hdr; 449 union sctp_addr daddr; 450 unsigned long sent_at; 451 __u64 hb_nonce; 452 } __attribute__((packed)) sctp_sender_hb_info_t; 453 454 /* 455 * RFC 2960 1.3.2 Sequenced Delivery within Streams 456 * 457 * The term "stream" is used in SCTP to refer to a sequence of user 458 * messages that are to be delivered to the upper-layer protocol in 459 * order with respect to other messages within the same stream. This is 460 * in contrast to its usage in TCP, where it refers to a sequence of 461 * bytes (in this document a byte is assumed to be eight bits). 462 * ... 463 * 464 * This is the structure we use to track both our outbound and inbound 465 * SSN, or Stream Sequence Numbers. 466 */ 467 468 struct sctp_stream { 469 __u16 *ssn; 470 unsigned int len; 471 }; 472 473 struct sctp_ssnmap { 474 struct sctp_stream in; 475 struct sctp_stream out; 476 int malloced; 477 }; 478 479 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, 480 gfp_t gfp); 481 void sctp_ssnmap_free(struct sctp_ssnmap *map); 482 void sctp_ssnmap_clear(struct sctp_ssnmap *map); 483 484 /* What is the current SSN number for this stream? */ 485 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id) 486 { 487 return stream->ssn[id]; 488 } 489 490 /* Return the next SSN number for this stream. */ 491 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id) 492 { 493 return stream->ssn[id]++; 494 } 495 496 /* Skip over this ssn and all below. */ 497 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, 498 __u16 ssn) 499 { 500 stream->ssn[id] = ssn+1; 501 } 502 503 /* 504 * Pointers to address related SCTP functions. 505 * (i.e. things that depend on the address family.) 506 */ 507 struct sctp_af { 508 int (*sctp_xmit) (struct sk_buff *skb, 509 struct sctp_transport *, 510 int ipfragok); 511 int (*setsockopt) (struct sock *sk, 512 int level, 513 int optname, 514 char __user *optval, 515 int optlen); 516 int (*getsockopt) (struct sock *sk, 517 int level, 518 int optname, 519 char __user *optval, 520 int __user *optlen); 521 int (*compat_setsockopt) (struct sock *sk, 522 int level, 523 int optname, 524 char __user *optval, 525 int optlen); 526 int (*compat_getsockopt) (struct sock *sk, 527 int level, 528 int optname, 529 char __user *optval, 530 int __user *optlen); 531 struct dst_entry *(*get_dst) (struct sctp_association *asoc, 532 union sctp_addr *daddr, 533 union sctp_addr *saddr); 534 void (*get_saddr) (struct sctp_association *asoc, 535 struct dst_entry *dst, 536 union sctp_addr *daddr, 537 union sctp_addr *saddr); 538 void (*copy_addrlist) (struct list_head *, 539 struct net_device *); 540 void (*dst_saddr) (union sctp_addr *saddr, 541 struct dst_entry *dst, 542 __be16 port); 543 int (*cmp_addr) (const union sctp_addr *addr1, 544 const union sctp_addr *addr2); 545 void (*addr_copy) (union sctp_addr *dst, 546 union sctp_addr *src); 547 void (*from_skb) (union sctp_addr *, 548 struct sk_buff *skb, 549 int saddr); 550 void (*from_sk) (union sctp_addr *, 551 struct sock *sk); 552 void (*to_sk_saddr) (union sctp_addr *, 553 struct sock *sk); 554 void (*to_sk_daddr) (union sctp_addr *, 555 struct sock *sk); 556 void (*from_addr_param) (union sctp_addr *, 557 union sctp_addr_param *, 558 __be16 port, int iif); 559 int (*to_addr_param) (const union sctp_addr *, 560 union sctp_addr_param *); 561 int (*addr_valid) (union sctp_addr *, 562 struct sctp_sock *, 563 const struct sk_buff *); 564 sctp_scope_t (*scope) (union sctp_addr *); 565 void (*inaddr_any) (union sctp_addr *, __be16); 566 int (*is_any) (const union sctp_addr *); 567 int (*available) (union sctp_addr *, 568 struct sctp_sock *); 569 int (*skb_iif) (const struct sk_buff *sk); 570 int (*is_ce) (const struct sk_buff *sk); 571 void (*seq_dump_addr)(struct seq_file *seq, 572 union sctp_addr *addr); 573 __u16 net_header_len; 574 int sockaddr_len; 575 sa_family_t sa_family; 576 struct list_head list; 577 }; 578 579 struct sctp_af *sctp_get_af_specific(sa_family_t); 580 int sctp_register_af(struct sctp_af *); 581 582 /* Protocol family functions. */ 583 struct sctp_pf { 584 void (*event_msgname)(struct sctp_ulpevent *, char *, int *); 585 void (*skb_msgname) (struct sk_buff *, char *, int *); 586 int (*af_supported) (sa_family_t, struct sctp_sock *); 587 int (*cmp_addr) (const union sctp_addr *, 588 const union sctp_addr *, 589 struct sctp_sock *); 590 int (*bind_verify) (struct sctp_sock *, union sctp_addr *); 591 int (*send_verify) (struct sctp_sock *, union sctp_addr *); 592 int (*supported_addrs)(const struct sctp_sock *, __be16 *); 593 struct sock *(*create_accept_sk) (struct sock *sk, 594 struct sctp_association *asoc); 595 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *); 596 struct sctp_af *af; 597 }; 598 599 600 /* Structure to track chunk fragments that have been acked, but peer 601 * fragments of the same message have not. 602 */ 603 struct sctp_datamsg { 604 /* Chunks waiting to be submitted to lower layer. */ 605 struct list_head chunks; 606 /* Chunks that have been transmitted. */ 607 struct list_head track; 608 /* Reference counting. */ 609 atomic_t refcnt; 610 /* When is this message no longer interesting to the peer? */ 611 unsigned long expires_at; 612 /* Did the messenge fail to send? */ 613 int send_error; 614 char send_failed; 615 /* Control whether chunks from this message can be abandoned. */ 616 char can_abandon; 617 }; 618 619 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, 620 struct sctp_sndrcvinfo *, 621 struct msghdr *, int len); 622 void sctp_datamsg_put(struct sctp_datamsg *); 623 void sctp_datamsg_free(struct sctp_datamsg *); 624 void sctp_datamsg_track(struct sctp_chunk *); 625 void sctp_chunk_fail(struct sctp_chunk *, int error); 626 int sctp_chunk_abandoned(struct sctp_chunk *); 627 628 /* RFC2960 1.4 Key Terms 629 * 630 * o Chunk: A unit of information within an SCTP packet, consisting of 631 * a chunk header and chunk-specific content. 632 * 633 * As a matter of convenience, we remember the SCTP common header for 634 * each chunk as well as a few other header pointers... 635 */ 636 struct sctp_chunk { 637 struct list_head list; 638 639 atomic_t refcnt; 640 641 /* This is our link to the per-transport transmitted list. */ 642 struct list_head transmitted_list; 643 644 /* This field is used by chunks that hold fragmented data. 645 * For the first fragment this is the list that holds the rest of 646 * fragments. For the remaining fragments, this is the link to the 647 * frag_list maintained in the first fragment. 648 */ 649 struct list_head frag_list; 650 651 /* This points to the sk_buff containing the actual data. */ 652 struct sk_buff *skb; 653 654 /* These are the SCTP headers by reverse order in a packet. 655 * Note that some of these may happen more than once. In that 656 * case, we point at the "current" one, whatever that means 657 * for that level of header. 658 */ 659 660 /* We point this at the FIRST TLV parameter to chunk_hdr. */ 661 union sctp_params param_hdr; 662 union { 663 __u8 *v; 664 struct sctp_datahdr *data_hdr; 665 struct sctp_inithdr *init_hdr; 666 struct sctp_sackhdr *sack_hdr; 667 struct sctp_heartbeathdr *hb_hdr; 668 struct sctp_sender_hb_info *hbs_hdr; 669 struct sctp_shutdownhdr *shutdown_hdr; 670 struct sctp_signed_cookie *cookie_hdr; 671 struct sctp_ecnehdr *ecne_hdr; 672 struct sctp_cwrhdr *ecn_cwr_hdr; 673 struct sctp_errhdr *err_hdr; 674 struct sctp_addiphdr *addip_hdr; 675 struct sctp_fwdtsn_hdr *fwdtsn_hdr; 676 } subh; 677 678 __u8 *chunk_end; 679 680 struct sctp_chunkhdr *chunk_hdr; 681 struct sctphdr *sctp_hdr; 682 683 /* This needs to be recoverable for SCTP_SEND_FAILED events. */ 684 struct sctp_sndrcvinfo sinfo; 685 686 /* Which association does this belong to? */ 687 struct sctp_association *asoc; 688 689 /* What endpoint received this chunk? */ 690 struct sctp_ep_common *rcvr; 691 692 /* We fill this in if we are calculating RTT. */ 693 unsigned long sent_at; 694 695 /* What is the origin IP address for this chunk? */ 696 union sctp_addr source; 697 /* Destination address for this chunk. */ 698 union sctp_addr dest; 699 700 /* For outbound message, track all fragments for SEND_FAILED. */ 701 struct sctp_datamsg *msg; 702 703 /* For an inbound chunk, this tells us where it came from. 704 * For an outbound chunk, it tells us where we'd like it to 705 * go. It is NULL if we have no preference. 706 */ 707 struct sctp_transport *transport; 708 709 __u8 rtt_in_progress; /* Is this chunk used for RTT calculation? */ 710 __u8 resent; /* Has this chunk ever been retransmitted. */ 711 __u8 has_tsn; /* Does this chunk have a TSN yet? */ 712 __u8 has_ssn; /* Does this chunk have a SSN yet? */ 713 __u8 singleton; /* Was this the only chunk in the packet? */ 714 __u8 end_of_packet; /* Was this the last chunk in the packet? */ 715 __u8 ecn_ce_done; /* Have we processed the ECN CE bit? */ 716 __u8 pdiscard; /* Discard the whole packet now? */ 717 __u8 tsn_gap_acked; /* Is this chunk acked by a GAP ACK? */ 718 __s8 fast_retransmit; /* Is this chunk fast retransmitted? */ 719 __u8 tsn_missing_report; /* Data chunk missing counter. */ 720 __u8 data_accepted; /* At least 1 chunk in this packet accepted */ 721 }; 722 723 void sctp_chunk_hold(struct sctp_chunk *); 724 void sctp_chunk_put(struct sctp_chunk *); 725 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 726 struct iovec *data); 727 void sctp_chunk_free(struct sctp_chunk *); 728 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); 729 struct sctp_chunk *sctp_chunkify(struct sk_buff *, 730 const struct sctp_association *, 731 struct sock *); 732 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, 733 union sctp_addr *); 734 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); 735 736 /* This is a structure for holding either an IPv6 or an IPv4 address. */ 737 struct sctp_sockaddr_entry { 738 struct list_head list; 739 union sctp_addr a; 740 __u8 use_as_src; 741 }; 742 743 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *); 744 745 /* This structure holds lists of chunks as we are assembling for 746 * transmission. 747 */ 748 struct sctp_packet { 749 /* These are the SCTP header values (host order) for the packet. */ 750 __u16 source_port; 751 __u16 destination_port; 752 __u32 vtag; 753 754 /* This contains the payload chunks. */ 755 struct list_head chunk_list; 756 757 /* This is the overhead of the sctp and ip headers. */ 758 size_t overhead; 759 /* This is the total size of all chunks INCLUDING padding. */ 760 size_t size; 761 762 /* The packet is destined for this transport address. 763 * The function we finally use to pass down to the next lower 764 * layer lives in the transport structure. 765 */ 766 struct sctp_transport *transport; 767 768 /* This packet contains a COOKIE-ECHO chunk. */ 769 char has_cookie_echo; 770 771 /* This packet containsa SACK chunk. */ 772 char has_sack; 773 774 /* SCTP cannot fragment this packet. So let ip fragment it. */ 775 char ipfragok; 776 777 int malloced; 778 }; 779 780 struct sctp_packet *sctp_packet_init(struct sctp_packet *, 781 struct sctp_transport *, 782 __u16 sport, __u16 dport); 783 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int); 784 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *, 785 struct sctp_chunk *); 786 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *, 787 struct sctp_chunk *); 788 int sctp_packet_transmit(struct sctp_packet *); 789 void sctp_packet_free(struct sctp_packet *); 790 791 static inline int sctp_packet_empty(struct sctp_packet *packet) 792 { 793 return (packet->size == packet->overhead); 794 } 795 796 /* This represents a remote transport address. 797 * For local transport addresses, we just use union sctp_addr. 798 * 799 * RFC2960 Section 1.4 Key Terms 800 * 801 * o Transport address: A Transport Address is traditionally defined 802 * by Network Layer address, Transport Layer protocol and Transport 803 * Layer port number. In the case of SCTP running over IP, a 804 * transport address is defined by the combination of an IP address 805 * and an SCTP port number (where SCTP is the Transport protocol). 806 * 807 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control 808 * 809 * o The sender keeps a separate congestion control parameter set for 810 * each of the destination addresses it can send to (not each 811 * source-destination pair but for each destination). The parameters 812 * should decay if the address is not used for a long enough time 813 * period. 814 * 815 */ 816 struct sctp_transport { 817 /* A list of transports. */ 818 struct list_head transports; 819 820 /* Reference counting. */ 821 atomic_t refcnt; 822 int dead; 823 824 /* This is the peer's IP address and port. */ 825 union sctp_addr ipaddr; 826 827 /* These are the functions we call to handle LLP stuff. */ 828 struct sctp_af *af_specific; 829 830 /* Which association do we belong to? */ 831 struct sctp_association *asoc; 832 833 /* RFC2960 834 * 835 * 12.3 Per Transport Address Data 836 * 837 * For each destination transport address in the peer's 838 * address list derived from the INIT or INIT ACK chunk, a 839 * number of data elements needs to be maintained including: 840 */ 841 __u32 rtt; /* This is the most recent RTT. */ 842 843 /* RTO : The current retransmission timeout value. */ 844 unsigned long rto; 845 846 /* RTTVAR : The current RTT variation. */ 847 __u32 rttvar; 848 849 /* SRTT : The current smoothed round trip time. */ 850 __u32 srtt; 851 852 /* RTO-Pending : A flag used to track if one of the DATA 853 * chunks sent to this address is currently being 854 * used to compute a RTT. If this flag is 0, 855 * the next DATA chunk sent to this destination 856 * should be used to compute a RTT and this flag 857 * should be set. Every time the RTT 858 * calculation completes (i.e. the DATA chunk 859 * is SACK'd) clear this flag. 860 */ 861 int rto_pending; 862 863 /* 864 * These are the congestion stats. 865 */ 866 /* cwnd : The current congestion window. */ 867 __u32 cwnd; /* This is the actual cwnd. */ 868 869 /* ssthresh : The current slow start threshold value. */ 870 __u32 ssthresh; 871 872 /* partial : The tracking method for increase of cwnd when in 873 * bytes acked : congestion avoidance mode (see Section 6.2.2) 874 */ 875 __u32 partial_bytes_acked; 876 877 /* Data that has been sent, but not acknowledged. */ 878 __u32 flight_size; 879 880 /* Destination */ 881 struct dst_entry *dst; 882 /* Source address. */ 883 union sctp_addr saddr; 884 885 /* When was the last time(in jiffies) that a data packet was sent on 886 * this transport? This is used to adjust the cwnd when the transport 887 * becomes inactive. 888 */ 889 unsigned long last_time_used; 890 891 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 892 * the destination address every heartbeat interval. 893 */ 894 unsigned long hbinterval; 895 896 /* SACK delay timeout */ 897 unsigned long sackdelay; 898 899 /* When was the last time (in jiffies) that we heard from this 900 * transport? We use this to pick new active and retran paths. 901 */ 902 unsigned long last_time_heard; 903 904 /* Last time(in jiffies) when cwnd is reduced due to the congestion 905 * indication based on ECNE chunk. 906 */ 907 unsigned long last_time_ecne_reduced; 908 909 /* This is the max_retrans value for the transport and will 910 * be initialized from the assocs value. This can be changed 911 * using SCTP_SET_PEER_ADDR_PARAMS socket option. 912 */ 913 __u16 pathmaxrxt; 914 915 /* PMTU : The current known path MTU. */ 916 __u32 pathmtu; 917 918 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 919 __u32 param_flags; 920 921 /* The number of times INIT has been sent on this transport. */ 922 int init_sent_count; 923 924 /* state : The current state of this destination, 925 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKOWN. 926 */ 927 int state; 928 929 /* These are the error stats for this destination. */ 930 931 /* Error count : The current error count for this destination. */ 932 unsigned short error_count; 933 934 /* Per : A timer used by each destination. 935 * Destination : 936 * Timer : 937 * 938 * [Everywhere else in the text this is called T3-rtx. -ed] 939 */ 940 struct timer_list T3_rtx_timer; 941 942 /* Heartbeat timer is per destination. */ 943 struct timer_list hb_timer; 944 945 /* Since we're using per-destination retransmission timers 946 * (see above), we're also using per-destination "transmitted" 947 * queues. This probably ought to be a private struct 948 * accessible only within the outqueue, but it's not, yet. 949 */ 950 struct list_head transmitted; 951 952 /* We build bundle-able packets for this transport here. */ 953 struct sctp_packet packet; 954 955 /* This is the list of transports that have chunks to send. */ 956 struct list_head send_ready; 957 958 int malloced; /* Is this structure kfree()able? */ 959 960 /* State information saved for SFR_CACC algorithm. The key 961 * idea in SFR_CACC is to maintain state at the sender on a 962 * per-destination basis when a changeover happens. 963 * char changeover_active; 964 * char cycling_changeover; 965 * __u32 next_tsn_at_change; 966 * char cacc_saw_newack; 967 */ 968 struct { 969 /* An unsigned integer, which stores the next TSN to be 970 * used by the sender, at the moment of changeover. 971 */ 972 __u32 next_tsn_at_change; 973 974 /* A flag which indicates the occurrence of a changeover */ 975 char changeover_active; 976 977 /* A flag which indicates whether the change of primary is 978 * the first switch to this destination address during an 979 * active switch. 980 */ 981 char cycling_changeover; 982 983 /* A temporary flag, which is used during the processing of 984 * a SACK to estimate the causative TSN(s)'s group. 985 */ 986 char cacc_saw_newack; 987 } cacc; 988 989 /* 64-bit random number sent with heartbeat. */ 990 __u64 hb_nonce; 991 }; 992 993 struct sctp_transport *sctp_transport_new(const union sctp_addr *, 994 gfp_t); 995 void sctp_transport_set_owner(struct sctp_transport *, 996 struct sctp_association *); 997 void sctp_transport_route(struct sctp_transport *, union sctp_addr *, 998 struct sctp_sock *); 999 void sctp_transport_pmtu(struct sctp_transport *); 1000 void sctp_transport_free(struct sctp_transport *); 1001 void sctp_transport_reset_timers(struct sctp_transport *); 1002 void sctp_transport_hold(struct sctp_transport *); 1003 void sctp_transport_put(struct sctp_transport *); 1004 void sctp_transport_update_rto(struct sctp_transport *, __u32); 1005 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32); 1006 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t); 1007 unsigned long sctp_transport_timeout(struct sctp_transport *); 1008 void sctp_transport_reset(struct sctp_transport *); 1009 1010 1011 /* This is the structure we use to queue packets as they come into 1012 * SCTP. We write packets to it and read chunks from it. 1013 */ 1014 struct sctp_inq { 1015 /* This is actually a queue of sctp_chunk each 1016 * containing a partially decoded packet. 1017 */ 1018 struct list_head in_chunk_list; 1019 /* This is the packet which is currently off the in queue and is 1020 * being worked on through the inbound chunk processing. 1021 */ 1022 struct sctp_chunk *in_progress; 1023 1024 /* This is the delayed task to finish delivering inbound 1025 * messages. 1026 */ 1027 struct work_struct immediate; 1028 1029 int malloced; /* Is this structure kfree()able? */ 1030 }; 1031 1032 void sctp_inq_init(struct sctp_inq *); 1033 void sctp_inq_free(struct sctp_inq *); 1034 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet); 1035 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *); 1036 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t); 1037 1038 /* This is the structure we use to hold outbound chunks. You push 1039 * chunks in and they automatically pop out the other end as bundled 1040 * packets (it calls (*output_handler)()). 1041 * 1042 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1, 1043 * and 8.2 of the v13 draft. 1044 * 1045 * It handles retransmissions. The connection to the timeout portion 1046 * of the state machine is through sctp_..._timeout() and timeout_handler. 1047 * 1048 * If you feed it SACKs, it will eat them. 1049 * 1050 * If you give it big chunks, it will fragment them. 1051 * 1052 * It assigns TSN's to data chunks. This happens at the last possible 1053 * instant before transmission. 1054 * 1055 * When free()'d, it empties itself out via output_handler(). 1056 */ 1057 struct sctp_outq { 1058 struct sctp_association *asoc; 1059 1060 /* Data pending that has never been transmitted. */ 1061 struct list_head out_chunk_list; 1062 1063 unsigned out_qlen; /* Total length of queued data chunks. */ 1064 1065 /* Error of send failed, may used in SCTP_SEND_FAILED event. */ 1066 unsigned error; 1067 1068 /* These are control chunks we want to send. */ 1069 struct list_head control_chunk_list; 1070 1071 /* These are chunks that have been sacked but are above the 1072 * CTSN, or cumulative tsn ack point. 1073 */ 1074 struct list_head sacked; 1075 1076 /* Put chunks on this list to schedule them for 1077 * retransmission. 1078 */ 1079 struct list_head retransmit; 1080 1081 /* Put chunks on this list to save them for FWD TSN processing as 1082 * they were abandoned. 1083 */ 1084 struct list_head abandoned; 1085 1086 /* How many unackd bytes do we have in-flight? */ 1087 __u32 outstanding_bytes; 1088 1089 /* Corked? */ 1090 char cork; 1091 1092 /* Is this structure empty? */ 1093 char empty; 1094 1095 /* Are we kfree()able? */ 1096 char malloced; 1097 }; 1098 1099 void sctp_outq_init(struct sctp_association *, struct sctp_outq *); 1100 void sctp_outq_teardown(struct sctp_outq *); 1101 void sctp_outq_free(struct sctp_outq*); 1102 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk); 1103 int sctp_outq_flush(struct sctp_outq *, int); 1104 int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *); 1105 int sctp_outq_is_empty(const struct sctp_outq *); 1106 void sctp_outq_restart(struct sctp_outq *); 1107 1108 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *, 1109 sctp_retransmit_reason_t); 1110 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); 1111 int sctp_outq_uncork(struct sctp_outq *); 1112 /* Uncork and flush an outqueue. */ 1113 static inline void sctp_outq_cork(struct sctp_outq *q) 1114 { 1115 q->cork = 1; 1116 } 1117 1118 /* These bind address data fields common between endpoints and associations */ 1119 struct sctp_bind_addr { 1120 1121 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1122 * 1123 * SCTP Port: The local SCTP port number the endpoint is 1124 * bound to. 1125 */ 1126 __u16 port; 1127 1128 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1129 * 1130 * Address List: The list of IP addresses that this instance 1131 * has bound. This information is passed to one's 1132 * peer(s) in INIT and INIT ACK chunks. 1133 */ 1134 struct list_head address_list; 1135 1136 int malloced; /* Are we kfree()able? */ 1137 }; 1138 1139 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port); 1140 void sctp_bind_addr_free(struct sctp_bind_addr *); 1141 int sctp_bind_addr_copy(struct sctp_bind_addr *dest, 1142 const struct sctp_bind_addr *src, 1143 sctp_scope_t scope, gfp_t gfp, 1144 int flags); 1145 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1146 __u8 use_as_src, gfp_t gfp); 1147 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *); 1148 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, 1149 struct sctp_sock *); 1150 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 1151 const union sctp_addr *addrs, 1152 int addrcnt, 1153 struct sctp_sock *opt); 1154 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 1155 int *addrs_len, 1156 gfp_t gfp); 1157 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, 1158 __u16 port, gfp_t gfp); 1159 1160 sctp_scope_t sctp_scope(const union sctp_addr *); 1161 int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope); 1162 int sctp_is_any(const union sctp_addr *addr); 1163 int sctp_addr_is_valid(const union sctp_addr *addr); 1164 1165 1166 /* What type of endpoint? */ 1167 typedef enum { 1168 SCTP_EP_TYPE_SOCKET, 1169 SCTP_EP_TYPE_ASSOCIATION, 1170 } sctp_endpoint_type_t; 1171 1172 /* 1173 * A common base class to bridge the implmentation view of a 1174 * socket (usually listening) endpoint versus an association's 1175 * local endpoint. 1176 * This common structure is useful for several purposes: 1177 * 1) Common interface for lookup routines. 1178 * a) Subfunctions work for either endpoint or association 1179 * b) Single interface to lookup allows hiding the lookup lock rather 1180 * than acquiring it externally. 1181 * 2) Common interface for the inbound chunk handling/state machine. 1182 * 3) Common object handling routines for reference counting, etc. 1183 * 4) Disentangle association lookup from endpoint lookup, where we 1184 * do not have to find our endpoint to find our association. 1185 * 1186 */ 1187 1188 struct sctp_ep_common { 1189 /* Fields to help us manage our entries in the hash tables. */ 1190 struct sctp_ep_common *next; 1191 struct sctp_ep_common **pprev; 1192 int hashent; 1193 1194 /* Runtime type information. What kind of endpoint is this? */ 1195 sctp_endpoint_type_t type; 1196 1197 /* Some fields to help us manage this object. 1198 * refcnt - Reference count access to this object. 1199 * dead - Do not attempt to use this object. 1200 * malloced - Do we need to kfree this object? 1201 */ 1202 atomic_t refcnt; 1203 char dead; 1204 char malloced; 1205 1206 /* What socket does this endpoint belong to? */ 1207 struct sock *sk; 1208 1209 /* This is where we receive inbound chunks. */ 1210 struct sctp_inq inqueue; 1211 1212 /* This substructure includes the defining parameters of the 1213 * endpoint: 1214 * bind_addr.port is our shared port number. 1215 * bind_addr.address_list is our set of local IP addresses. 1216 */ 1217 struct sctp_bind_addr bind_addr; 1218 1219 /* Protection during address list comparisons. */ 1220 rwlock_t addr_lock; 1221 }; 1222 1223 1224 /* RFC Section 1.4 Key Terms 1225 * 1226 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a 1227 * multi-homed host, an SCTP endpoint is represented to its peers as a 1228 * combination of a set of eligible destination transport addresses to 1229 * which SCTP packets can be sent and a set of eligible source 1230 * transport addresses from which SCTP packets can be received. 1231 * All transport addresses used by an SCTP endpoint must use the 1232 * same port number, but can use multiple IP addresses. A transport 1233 * address used by an SCTP endpoint must not be used by another 1234 * SCTP endpoint. In other words, a transport address is unique 1235 * to an SCTP endpoint. 1236 * 1237 * From an implementation perspective, each socket has one of these. 1238 * A TCP-style socket will have exactly one association on one of 1239 * these. An UDP-style socket will have multiple associations hanging 1240 * off one of these. 1241 */ 1242 1243 struct sctp_endpoint { 1244 /* Common substructure for endpoint and association. */ 1245 struct sctp_ep_common base; 1246 1247 /* Associations: A list of current associations and mappings 1248 * to the data consumers for each association. This 1249 * may be in the form of a hash table or other 1250 * implementation dependent structure. The data 1251 * consumers may be process identification 1252 * information such as file descriptors, named pipe 1253 * pointer, or table pointers dependent on how SCTP 1254 * is implemented. 1255 */ 1256 /* This is really a list of struct sctp_association entries. */ 1257 struct list_head asocs; 1258 1259 /* Secret Key: A secret key used by this endpoint to compute 1260 * the MAC. This SHOULD be a cryptographic quality 1261 * random number with a sufficient length. 1262 * Discussion in [RFC1750] can be helpful in 1263 * selection of the key. 1264 */ 1265 __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE]; 1266 int current_key; 1267 int last_key; 1268 int key_changed_at; 1269 1270 /* digest: This is a digest of the sctp cookie. This field is 1271 * only used on the receive path when we try to validate 1272 * that the cookie has not been tampered with. We put 1273 * this here so we pre-allocate this once and can re-use 1274 * on every receive. 1275 */ 1276 __u8 *digest; 1277 1278 /* sendbuf acct. policy. */ 1279 __u32 sndbuf_policy; 1280 1281 /* rcvbuf acct. policy. */ 1282 __u32 rcvbuf_policy; 1283 }; 1284 1285 /* Recover the outter endpoint structure. */ 1286 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) 1287 { 1288 struct sctp_endpoint *ep; 1289 1290 ep = container_of(base, struct sctp_endpoint, base); 1291 return ep; 1292 } 1293 1294 /* These are function signatures for manipulating endpoints. */ 1295 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t); 1296 void sctp_endpoint_free(struct sctp_endpoint *); 1297 void sctp_endpoint_put(struct sctp_endpoint *); 1298 void sctp_endpoint_hold(struct sctp_endpoint *); 1299 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); 1300 struct sctp_association *sctp_endpoint_lookup_assoc( 1301 const struct sctp_endpoint *ep, 1302 const union sctp_addr *paddr, 1303 struct sctp_transport **); 1304 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *, 1305 const union sctp_addr *); 1306 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *, 1307 const union sctp_addr *); 1308 int sctp_has_association(const union sctp_addr *laddr, 1309 const union sctp_addr *paddr); 1310 1311 int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t, 1312 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk, 1313 struct sctp_chunk **err_chunk); 1314 int sctp_process_init(struct sctp_association *, sctp_cid_t cid, 1315 const union sctp_addr *peer, 1316 sctp_init_chunk_t *init, gfp_t gfp); 1317 __u32 sctp_generate_tag(const struct sctp_endpoint *); 1318 __u32 sctp_generate_tsn(const struct sctp_endpoint *); 1319 1320 struct sctp_inithdr_host { 1321 __u32 init_tag; 1322 __u32 a_rwnd; 1323 __u16 num_outbound_streams; 1324 __u16 num_inbound_streams; 1325 __u32 initial_tsn; 1326 }; 1327 1328 /* RFC2960 1329 * 1330 * 12. Recommended Transmission Control Block (TCB) Parameters 1331 * 1332 * This section details a recommended set of parameters that should 1333 * be contained within the TCB for an implementation. This section is 1334 * for illustrative purposes and should not be deemed as requirements 1335 * on an implementation or as an exhaustive list of all parameters 1336 * inside an SCTP TCB. Each implementation may need its own additional 1337 * parameters for optimization. 1338 */ 1339 1340 1341 /* Here we have information about each individual association. */ 1342 struct sctp_association { 1343 1344 /* A base structure common to endpoint and association. 1345 * In this context, it represents the associations's view 1346 * of the local endpoint of the association. 1347 */ 1348 struct sctp_ep_common base; 1349 1350 /* Associations on the same socket. */ 1351 struct list_head asocs; 1352 1353 /* association id. */ 1354 sctp_assoc_t assoc_id; 1355 1356 /* This is our parent endpoint. */ 1357 struct sctp_endpoint *ep; 1358 1359 /* These are those association elements needed in the cookie. */ 1360 struct sctp_cookie c; 1361 1362 /* This is all information about our peer. */ 1363 struct { 1364 /* rwnd 1365 * 1366 * Peer Rwnd : Current calculated value of the peer's rwnd. 1367 */ 1368 __u32 rwnd; 1369 1370 /* transport_addr_list 1371 * 1372 * Peer : A list of SCTP transport addresses that the 1373 * Transport : peer is bound to. This information is derived 1374 * Address : from the INIT or INIT ACK and is used to 1375 * List : associate an inbound packet with a given 1376 * : association. Normally this information is 1377 * : hashed or keyed for quick lookup and access 1378 * : of the TCB. 1379 * : The list is also initialized with the list 1380 * : of addresses passed with the sctp_connectx() 1381 * : call. 1382 * 1383 * It is a list of SCTP_transport's. 1384 */ 1385 struct list_head transport_addr_list; 1386 1387 /* transport_count 1388 * 1389 * Peer : A count of the number of peer addresses 1390 * Transport : in the Peer Transport Address List. 1391 * Address : 1392 * Count : 1393 */ 1394 __u16 transport_count; 1395 1396 /* port 1397 * The transport layer port number. 1398 */ 1399 __u16 port; 1400 1401 /* primary_path 1402 * 1403 * Primary : This is the current primary destination 1404 * Path : transport address of the peer endpoint. It 1405 * : may also specify a source transport address 1406 * : on this endpoint. 1407 * 1408 * All of these paths live on transport_addr_list. 1409 * 1410 * At the bakeoffs, we discovered that the intent of 1411 * primaryPath is that it only changes when the ULP 1412 * asks to have it changed. We add the activePath to 1413 * designate the connection we are currently using to 1414 * transmit new data and most control chunks. 1415 */ 1416 struct sctp_transport *primary_path; 1417 1418 /* Cache the primary path address here, when we 1419 * need a an address for msg_name. 1420 */ 1421 union sctp_addr primary_addr; 1422 1423 /* active_path 1424 * The path that we are currently using to 1425 * transmit new data and most control chunks. 1426 */ 1427 struct sctp_transport *active_path; 1428 1429 /* retran_path 1430 * 1431 * RFC2960 6.4 Multi-homed SCTP Endpoints 1432 * ... 1433 * Furthermore, when its peer is multi-homed, an 1434 * endpoint SHOULD try to retransmit a chunk to an 1435 * active destination transport address that is 1436 * different from the last destination address to 1437 * which the DATA chunk was sent. 1438 */ 1439 struct sctp_transport *retran_path; 1440 1441 /* Pointer to last transport I have sent on. */ 1442 struct sctp_transport *last_sent_to; 1443 1444 /* This is the last transport I have received DATA on. */ 1445 struct sctp_transport *last_data_from; 1446 1447 /* 1448 * Mapping An array of bits or bytes indicating which out of 1449 * Array order TSN's have been received (relative to the 1450 * Last Rcvd TSN). If no gaps exist, i.e. no out of 1451 * order packets have been received, this array 1452 * will be set to all zero. This structure may be 1453 * in the form of a circular buffer or bit array. 1454 * 1455 * Last Rcvd : This is the last TSN received in 1456 * TSN : sequence. This value is set initially by 1457 * : taking the peer's Initial TSN, received in 1458 * : the INIT or INIT ACK chunk, and subtracting 1459 * : one from it. 1460 * 1461 * Throughout most of the specification this is called the 1462 * "Cumulative TSN ACK Point". In this case, we 1463 * ignore the advice in 12.2 in favour of the term 1464 * used in the bulk of the text. This value is hidden 1465 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). 1466 */ 1467 struct sctp_tsnmap tsn_map; 1468 __u8 _map[sctp_tsnmap_storage_size(SCTP_TSN_MAP_SIZE)]; 1469 1470 /* Ack State : This flag indicates if the next received 1471 * : packet is to be responded to with a 1472 * : SACK. This is initializedto 0. When a packet 1473 * : is received it is incremented. If this value 1474 * : reaches 2 or more, a SACK is sent and the 1475 * : value is reset to 0. Note: This is used only 1476 * : when no DATA chunks are received out of 1477 * : order. When DATA chunks are out of order, 1478 * : SACK's are not delayed (see Section 6). 1479 */ 1480 __u8 sack_needed; /* Do we need to sack the peer? */ 1481 1482 /* These are capabilities which our peer advertised. */ 1483 __u8 ecn_capable; /* Can peer do ECN? */ 1484 __u8 ipv4_address; /* Peer understands IPv4 addresses? */ 1485 __u8 ipv6_address; /* Peer understands IPv6 addresses? */ 1486 __u8 hostname_address;/* Peer understands DNS addresses? */ 1487 __u8 asconf_capable; /* Does peer support ADDIP? */ 1488 __u8 prsctp_capable; /* Can peer do PR-SCTP? */ 1489 1490 __u32 adaptation_ind; /* Adaptation Code point. */ 1491 1492 /* This mask is used to disable sending the ASCONF chunk 1493 * with specified parameter to peer. 1494 */ 1495 __be16 addip_disabled_mask; 1496 1497 struct sctp_inithdr_host i; 1498 int cookie_len; 1499 void *cookie; 1500 1501 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1502 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the 1503 * Initial TSN Value minus 1 1504 */ 1505 __u32 addip_serial; 1506 } peer; 1507 1508 /* State : A state variable indicating what state the 1509 * : association is in, i.e. COOKIE-WAIT, 1510 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, 1511 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. 1512 * 1513 * Note: No "CLOSED" state is illustrated since if a 1514 * association is "CLOSED" its TCB SHOULD be removed. 1515 * 1516 * In this implementation we DO have a CLOSED 1517 * state which is used during initiation and shutdown. 1518 * 1519 * State takes values from SCTP_STATE_*. 1520 */ 1521 sctp_state_t state; 1522 1523 /* The cookie life I award for any cookie. */ 1524 struct timeval cookie_life; 1525 1526 /* Overall : The overall association error count. 1527 * Error Count : [Clear this any time I get something.] 1528 */ 1529 int overall_error_count; 1530 1531 /* These are the association's initial, max, and min RTO values. 1532 * These values will be initialized by system defaults, but can 1533 * be modified via the SCTP_RTOINFO socket option. 1534 */ 1535 unsigned long rto_initial; 1536 unsigned long rto_max; 1537 unsigned long rto_min; 1538 1539 /* Maximum number of new data packets that can be sent in a burst. */ 1540 int max_burst; 1541 1542 /* This is the max_retrans value for the association. This value will 1543 * be initialized initialized from system defaults, but can be 1544 * modified by the SCTP_ASSOCINFO socket option. 1545 */ 1546 int max_retrans; 1547 1548 /* Maximum number of times the endpoint will retransmit INIT */ 1549 __u16 max_init_attempts; 1550 1551 /* How many times have we resent an INIT? */ 1552 __u16 init_retries; 1553 1554 /* The largest timeout or RTO value to use in attempting an INIT */ 1555 unsigned long max_init_timeo; 1556 1557 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 1558 * the destination address every heartbeat interval. This value 1559 * will be inherited by all new transports. 1560 */ 1561 unsigned long hbinterval; 1562 1563 /* This is the max_retrans value for new transports in the 1564 * association. 1565 */ 1566 __u16 pathmaxrxt; 1567 1568 /* Association : The smallest PMTU discovered for all of the 1569 * PMTU : peer's transport addresses. 1570 */ 1571 __u32 pathmtu; 1572 1573 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 1574 __u32 param_flags; 1575 1576 /* SACK delay timeout */ 1577 unsigned long sackdelay; 1578 1579 1580 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1581 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; 1582 1583 /* Transport to which SHUTDOWN chunk was last sent. */ 1584 struct sctp_transport *shutdown_last_sent_to; 1585 1586 /* Transport to which INIT chunk was last sent. */ 1587 struct sctp_transport *init_last_sent_to; 1588 1589 /* Next TSN : The next TSN number to be assigned to a new 1590 * : DATA chunk. This is sent in the INIT or INIT 1591 * : ACK chunk to the peer and incremented each 1592 * : time a DATA chunk is assigned a TSN 1593 * : (normally just prior to transmit or during 1594 * : fragmentation). 1595 */ 1596 __u32 next_tsn; 1597 1598 /* 1599 * Last Rcvd : This is the last TSN received in sequence. This value 1600 * TSN : is set initially by taking the peer's Initial TSN, 1601 * : received in the INIT or INIT ACK chunk, and 1602 * : subtracting one from it. 1603 * 1604 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. 1605 */ 1606 1607 __u32 ctsn_ack_point; 1608 1609 /* PR-SCTP Advanced.Peer.Ack.Point */ 1610 __u32 adv_peer_ack_point; 1611 1612 /* Highest TSN that is acknowledged by incoming SACKs. */ 1613 __u32 highest_sacked; 1614 1615 /* The number of unacknowledged data chunks. Reported through 1616 * the SCTP_STATUS sockopt. 1617 */ 1618 __u16 unack_data; 1619 1620 /* This is the association's receive buffer space. This value is used 1621 * to set a_rwnd field in an INIT or a SACK chunk. 1622 */ 1623 __u32 rwnd; 1624 1625 /* This is the last advertised value of rwnd over a SACK chunk. */ 1626 __u32 a_rwnd; 1627 1628 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed 1629 * to slop over a maximum of the association's frag_point. 1630 */ 1631 __u32 rwnd_over; 1632 1633 /* This is the sndbuf size in use for the association. 1634 * This corresponds to the sndbuf size for the association, 1635 * as specified in the sk->sndbuf. 1636 */ 1637 int sndbuf_used; 1638 1639 /* This is the amount of memory that this association has allocated 1640 * in the receive path at any given time. 1641 */ 1642 atomic_t rmem_alloc; 1643 1644 /* This is the wait queue head for send requests waiting on 1645 * the association sndbuf space. 1646 */ 1647 wait_queue_head_t wait; 1648 1649 /* The message size at which SCTP fragmentation will occur. */ 1650 __u32 frag_point; 1651 1652 /* Counter used to count INIT errors. */ 1653 int init_err_counter; 1654 1655 /* Count the number of INIT cycles (for doubling timeout). */ 1656 int init_cycle; 1657 1658 /* Default send parameters. */ 1659 __u16 default_stream; 1660 __u16 default_flags; 1661 __u32 default_ppid; 1662 __u32 default_context; 1663 __u32 default_timetolive; 1664 1665 /* Default receive parameters */ 1666 __u32 default_rcv_context; 1667 1668 /* This tracks outbound ssn for a given stream. */ 1669 struct sctp_ssnmap *ssnmap; 1670 1671 /* All outbound chunks go through this structure. */ 1672 struct sctp_outq outqueue; 1673 1674 /* A smart pipe that will handle reordering and fragmentation, 1675 * as well as handle passing events up to the ULP. 1676 */ 1677 struct sctp_ulpq ulpq; 1678 1679 /* Last TSN that caused an ECNE Chunk to be sent. */ 1680 __u32 last_ecne_tsn; 1681 1682 /* Last TSN that caused a CWR Chunk to be sent. */ 1683 __u32 last_cwr_tsn; 1684 1685 /* How many duplicated TSNs have we seen? */ 1686 int numduptsns; 1687 1688 /* Number of seconds of idle time before an association is closed. 1689 * In the association context, this is really used as a boolean 1690 * since the real timeout is stored in the timeouts array 1691 */ 1692 __u32 autoclose; 1693 1694 /* These are to support 1695 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses 1696 * and Enforcement of Flow and Message Limits" 1697 * <draft-ietf-tsvwg-addip-sctp-02.txt> 1698 * or "ADDIP" for short. 1699 */ 1700 1701 1702 1703 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1704 * 1705 * R1) One and only one ASCONF Chunk MAY be in transit and 1706 * unacknowledged at any one time. If a sender, after sending 1707 * an ASCONF chunk, decides it needs to transfer another 1708 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1709 * returns from the previous ASCONF Chunk before sending a 1710 * subsequent ASCONF. Note this restriction binds each side, 1711 * so at any time two ASCONF may be in-transit on any given 1712 * association (one sent from each endpoint). 1713 * 1714 * [This is our one-and-only-one ASCONF in flight. If we do 1715 * not have an ASCONF in flight, this is NULL.] 1716 */ 1717 struct sctp_chunk *addip_last_asconf; 1718 1719 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1720 * 1721 * IMPLEMENTATION NOTE: As an optimization a receiver may wish 1722 * to save the last ASCONF-ACK for some predetermined period 1723 * of time and instead of re-processing the ASCONF (with the 1724 * same serial number) it may just re-transmit the 1725 * ASCONF-ACK. It may wish to use the arrival of a new serial 1726 * number to discard the previously saved ASCONF-ACK or any 1727 * other means it may choose to expire the saved ASCONF-ACK. 1728 * 1729 * [This is our saved ASCONF-ACK. We invalidate it when a new 1730 * ASCONF serial number arrives.] 1731 */ 1732 struct sctp_chunk *addip_last_asconf_ack; 1733 1734 /* These ASCONF chunks are waiting to be sent. 1735 * 1736 * These chunaks can't be pushed to outqueue until receiving 1737 * ASCONF_ACK for the previous ASCONF indicated by 1738 * addip_last_asconf, so as to guarantee that only one ASCONF 1739 * is in flight at any time. 1740 * 1741 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1742 * 1743 * In defining the ASCONF Chunk transfer procedures, it is 1744 * essential that these transfers MUST NOT cause congestion 1745 * within the network. To achieve this, we place these 1746 * restrictions on the transfer of ASCONF Chunks: 1747 * 1748 * R1) One and only one ASCONF Chunk MAY be in transit and 1749 * unacknowledged at any one time. If a sender, after sending 1750 * an ASCONF chunk, decides it needs to transfer another 1751 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1752 * returns from the previous ASCONF Chunk before sending a 1753 * subsequent ASCONF. Note this restriction binds each side, 1754 * so at any time two ASCONF may be in-transit on any given 1755 * association (one sent from each endpoint). 1756 * 1757 * 1758 * [I really think this is EXACTLY the sort of intelligence 1759 * which already resides in sctp_outq. Please move this 1760 * queue and its supporting logic down there. --piggy] 1761 */ 1762 struct list_head addip_chunk_list; 1763 1764 /* ADDIP Section 4.1 ASCONF Chunk Procedures 1765 * 1766 * A2) A serial number should be assigned to the Chunk. The 1767 * serial number SHOULD be a monotonically increasing 1768 * number. The serial number SHOULD be initialized at 1769 * the start of the association to the same value as the 1770 * Initial TSN and every time a new ASCONF chunk is created 1771 * it is incremented by one after assigning the serial number 1772 * to the newly created chunk. 1773 * 1774 * ADDIP 1775 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) 1776 * 1777 * Serial Number : 32 bits (unsigned integer) 1778 * 1779 * This value represents a Serial Number for the ASCONF 1780 * Chunk. The valid range of Serial Number is from 0 to 1781 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 1782 * after reaching 4294967295. 1783 */ 1784 __u32 addip_serial; 1785 1786 /* Need to send an ECNE Chunk? */ 1787 char need_ecne; 1788 1789 /* Is it a temporary association? */ 1790 char temp; 1791 }; 1792 1793 1794 /* An eyecatcher for determining if we are really looking at an 1795 * association data structure. 1796 */ 1797 enum { 1798 SCTP_ASSOC_EYECATCHER = 0xa550c123, 1799 }; 1800 1801 /* Recover the outter association structure. */ 1802 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) 1803 { 1804 struct sctp_association *asoc; 1805 1806 asoc = container_of(base, struct sctp_association, base); 1807 return asoc; 1808 } 1809 1810 /* These are function signatures for manipulating associations. */ 1811 1812 1813 struct sctp_association * 1814 sctp_association_new(const struct sctp_endpoint *, const struct sock *, 1815 sctp_scope_t scope, gfp_t gfp); 1816 void sctp_association_free(struct sctp_association *); 1817 void sctp_association_put(struct sctp_association *); 1818 void sctp_association_hold(struct sctp_association *); 1819 1820 struct sctp_transport *sctp_assoc_choose_init_transport( 1821 struct sctp_association *); 1822 struct sctp_transport *sctp_assoc_choose_shutdown_transport( 1823 struct sctp_association *); 1824 void sctp_assoc_update_retran_path(struct sctp_association *); 1825 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, 1826 const union sctp_addr *); 1827 int sctp_assoc_lookup_laddr(struct sctp_association *asoc, 1828 const union sctp_addr *laddr); 1829 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, 1830 const union sctp_addr *address, 1831 const gfp_t gfp, 1832 const int peer_state); 1833 void sctp_assoc_del_peer(struct sctp_association *asoc, 1834 const union sctp_addr *addr); 1835 void sctp_assoc_rm_peer(struct sctp_association *asoc, 1836 struct sctp_transport *peer); 1837 void sctp_assoc_control_transport(struct sctp_association *, 1838 struct sctp_transport *, 1839 sctp_transport_cmd_t, sctp_sn_error_t); 1840 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); 1841 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *, 1842 const union sctp_addr *, 1843 const union sctp_addr *); 1844 void sctp_assoc_migrate(struct sctp_association *, struct sock *); 1845 void sctp_assoc_update(struct sctp_association *old, 1846 struct sctp_association *new); 1847 1848 __u32 sctp_association_get_next_tsn(struct sctp_association *); 1849 1850 void sctp_assoc_sync_pmtu(struct sctp_association *); 1851 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned); 1852 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned); 1853 void sctp_assoc_set_primary(struct sctp_association *, 1854 struct sctp_transport *); 1855 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *, 1856 gfp_t); 1857 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, 1858 struct sctp_cookie*, 1859 gfp_t gfp); 1860 int sctp_assoc_set_id(struct sctp_association *, gfp_t); 1861 1862 int sctp_cmp_addr_exact(const union sctp_addr *ss1, 1863 const union sctp_addr *ss2); 1864 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); 1865 1866 /* A convenience structure to parse out SCTP specific CMSGs. */ 1867 typedef struct sctp_cmsgs { 1868 struct sctp_initmsg *init; 1869 struct sctp_sndrcvinfo *info; 1870 } sctp_cmsgs_t; 1871 1872 /* Structure for tracking memory objects */ 1873 typedef struct { 1874 char *label; 1875 atomic_t *counter; 1876 } sctp_dbg_objcnt_entry_t; 1877 1878 #endif /* __sctp_structs_h__ */ 1879