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