1 /* SCTP kernel reference Implementation 2 * (C) Copyright IBM Corp. 2001, 2004 3 * Copyright (c) 1999-2000 Cisco, Inc. 4 * Copyright (c) 1999-2001 Motorola, Inc. 5 * Copyright (c) 2001 Intel Corp. 6 * 7 * This file is part of the SCTP kernel reference Implementation 8 * 9 * The SCTP reference implementation is free software; 10 * you can redistribute it and/or modify it under the terms of 11 * the GNU General Public License as published by 12 * the Free Software Foundation; either version 2, or (at your option) 13 * any later version. 14 * 15 * The SCTP reference implementation is distributed in the hope that it 16 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 17 * ************************ 18 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 19 * See the GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with GNU CC; see the file COPYING. If not, write to 23 * the Free Software Foundation, 59 Temple Place - Suite 330, 24 * Boston, MA 02111-1307, USA. 25 * 26 * Please send any bug reports or fixes you make to the 27 * email addresses: 28 * lksctp developers <lksctp-developers@lists.sourceforge.net> 29 * 30 * Or submit a bug report through the following website: 31 * http://www.sf.net/projects/lksctp 32 * 33 * Written or modified by: 34 * Randall Stewart <randall@sctp.chicago.il.us> 35 * Ken Morneau <kmorneau@cisco.com> 36 * Qiaobing Xie <qxie1@email.mot.com> 37 * La Monte H.P. Yarroll <piggy@acm.org> 38 * Karl Knutson <karl@athena.chicago.il.us> 39 * Jon Grimm <jgrimm@us.ibm.com> 40 * Xingang Guo <xingang.guo@intel.com> 41 * Hui Huang <hui.huang@nokia.com> 42 * Sridhar Samudrala <sri@us.ibm.com> 43 * Daisy Chang <daisyc@us.ibm.com> 44 * Dajiang Zhang <dajiang.zhang@nokia.com> 45 * Ardelle Fan <ardelle.fan@intel.com> 46 * Ryan Layer <rmlayer@us.ibm.com> 47 * Anup Pemmaiah <pemmaiah@cc.usu.edu> 48 * Kevin Gao <kevin.gao@intel.com> 49 * 50 * Any bugs reported given to us we will try to fix... any fixes shared will 51 * be incorporated into the next SCTP release. 52 */ 53 54 #ifndef __sctp_structs_h__ 55 #define __sctp_structs_h__ 56 57 #include <linux/time.h> /* We get struct timespec. */ 58 #include <linux/socket.h> /* linux/in.h needs this!! */ 59 #include <linux/in.h> /* We get struct sockaddr_in. */ 60 #include <linux/in6.h> /* We get struct in6_addr */ 61 #include <linux/ipv6.h> 62 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */ 63 #include <asm/atomic.h> /* This gets us atomic counters. */ 64 #include <linux/skbuff.h> /* We need sk_buff_head. */ 65 #include <linux/workqueue.h> /* We need tq_struct. */ 66 #include <linux/sctp.h> /* We need sctp* header structs. */ 67 68 /* A convenience structure for handling sockaddr structures. 69 * We should wean ourselves off this. 70 */ 71 union sctp_addr { 72 struct sockaddr_in v4; 73 struct sockaddr_in6 v6; 74 struct sockaddr sa; 75 }; 76 77 /* Forward declarations for data structures. */ 78 struct sctp_globals; 79 struct sctp_endpoint; 80 struct sctp_association; 81 struct sctp_transport; 82 struct sctp_packet; 83 struct sctp_chunk; 84 struct sctp_inq; 85 struct sctp_outq; 86 struct sctp_bind_addr; 87 struct sctp_ulpq; 88 struct sctp_ep_common; 89 struct sctp_ssnmap; 90 91 92 #include <net/sctp/tsnmap.h> 93 #include <net/sctp/ulpevent.h> 94 #include <net/sctp/ulpqueue.h> 95 96 /* Structures useful for managing bind/connect. */ 97 98 struct sctp_bind_bucket { 99 unsigned short port; 100 unsigned short fastreuse; 101 struct sctp_bind_bucket *next; 102 struct sctp_bind_bucket **pprev; 103 struct hlist_head owner; 104 }; 105 106 struct sctp_bind_hashbucket { 107 spinlock_t lock; 108 struct sctp_bind_bucket *chain; 109 }; 110 111 /* Used for hashing all associations. */ 112 struct sctp_hashbucket { 113 rwlock_t lock; 114 struct sctp_ep_common *chain; 115 } __attribute__((__aligned__(8))); 116 117 118 /* The SCTP globals structure. */ 119 extern struct sctp_globals { 120 /* RFC2960 Section 14. Suggested SCTP Protocol Parameter Values 121 * 122 * The following protocol parameters are RECOMMENDED: 123 * 124 * RTO.Initial - 3 seconds 125 * RTO.Min - 1 second 126 * RTO.Max - 60 seconds 127 * RTO.Alpha - 1/8 (3 when converted to right shifts.) 128 * RTO.Beta - 1/4 (2 when converted to right shifts.) 129 */ 130 unsigned long rto_initial; 131 unsigned long rto_min; 132 unsigned long rto_max; 133 134 /* Note: rto_alpha and rto_beta are really defined as inverse 135 * powers of two to facilitate integer operations. 136 */ 137 int rto_alpha; 138 int rto_beta; 139 140 /* Max.Burst - 4 */ 141 int max_burst; 142 143 /* Whether Cookie Preservative is enabled(1) or not(0) */ 144 int cookie_preserve_enable; 145 146 /* Valid.Cookie.Life - 60 seconds */ 147 unsigned long valid_cookie_life; 148 149 /* Delayed SACK timeout 200ms default*/ 150 unsigned long sack_timeout; 151 152 /* HB.interval - 30 seconds */ 153 unsigned long hb_interval; 154 155 /* Association.Max.Retrans - 10 attempts 156 * Path.Max.Retrans - 5 attempts (per destination address) 157 * Max.Init.Retransmits - 8 attempts 158 */ 159 int max_retrans_association; 160 int max_retrans_path; 161 int max_retrans_init; 162 163 /* 164 * Policy for preforming sctp/socket accounting 165 * 0 - do socket level accounting, all assocs share sk_sndbuf 166 * 1 - do sctp accounting, each asoc may use sk_sndbuf bytes 167 */ 168 int sndbuf_policy; 169 170 /* 171 * Policy for preforming sctp/socket accounting 172 * 0 - do socket level accounting, all assocs share sk_rcvbuf 173 * 1 - do sctp accounting, each asoc may use sk_rcvbuf bytes 174 */ 175 int rcvbuf_policy; 176 177 /* The following variables are implementation specific. */ 178 179 /* Default initialization values to be applied to new associations. */ 180 __u16 max_instreams; 181 __u16 max_outstreams; 182 183 /* This is a list of groups of functions for each address 184 * family that we support. 185 */ 186 struct list_head address_families; 187 188 /* This is the hash of all endpoints. */ 189 int ep_hashsize; 190 struct sctp_hashbucket *ep_hashtable; 191 192 /* This is the hash of all associations. */ 193 int assoc_hashsize; 194 struct sctp_hashbucket *assoc_hashtable; 195 196 /* This is the sctp port control hash. */ 197 int port_hashsize; 198 int port_rover; 199 spinlock_t port_alloc_lock; /* Protects port_rover. */ 200 struct sctp_bind_hashbucket *port_hashtable; 201 202 /* This is the global local address list. 203 * We actively maintain this complete list of interfaces on 204 * the system by catching routing events. 205 * 206 * It is a list of sctp_sockaddr_entry. 207 */ 208 struct list_head local_addr_list; 209 spinlock_t local_addr_lock; 210 211 /* Flag to indicate if addip is enabled. */ 212 int addip_enable; 213 214 /* Flag to indicate if PR-SCTP is enabled. */ 215 int prsctp_enable; 216 } sctp_globals; 217 218 #define sctp_rto_initial (sctp_globals.rto_initial) 219 #define sctp_rto_min (sctp_globals.rto_min) 220 #define sctp_rto_max (sctp_globals.rto_max) 221 #define sctp_rto_alpha (sctp_globals.rto_alpha) 222 #define sctp_rto_beta (sctp_globals.rto_beta) 223 #define sctp_max_burst (sctp_globals.max_burst) 224 #define sctp_valid_cookie_life (sctp_globals.valid_cookie_life) 225 #define sctp_cookie_preserve_enable (sctp_globals.cookie_preserve_enable) 226 #define sctp_max_retrans_association (sctp_globals.max_retrans_association) 227 #define sctp_sndbuf_policy (sctp_globals.sndbuf_policy) 228 #define sctp_rcvbuf_policy (sctp_globals.rcvbuf_policy) 229 #define sctp_max_retrans_path (sctp_globals.max_retrans_path) 230 #define sctp_max_retrans_init (sctp_globals.max_retrans_init) 231 #define sctp_sack_timeout (sctp_globals.sack_timeout) 232 #define sctp_hb_interval (sctp_globals.hb_interval) 233 #define sctp_max_instreams (sctp_globals.max_instreams) 234 #define sctp_max_outstreams (sctp_globals.max_outstreams) 235 #define sctp_address_families (sctp_globals.address_families) 236 #define sctp_ep_hashsize (sctp_globals.ep_hashsize) 237 #define sctp_ep_hashtable (sctp_globals.ep_hashtable) 238 #define sctp_assoc_hashsize (sctp_globals.assoc_hashsize) 239 #define sctp_assoc_hashtable (sctp_globals.assoc_hashtable) 240 #define sctp_port_hashsize (sctp_globals.port_hashsize) 241 #define sctp_port_rover (sctp_globals.port_rover) 242 #define sctp_port_alloc_lock (sctp_globals.port_alloc_lock) 243 #define sctp_port_hashtable (sctp_globals.port_hashtable) 244 #define sctp_local_addr_list (sctp_globals.local_addr_list) 245 #define sctp_local_addr_lock (sctp_globals.local_addr_lock) 246 #define sctp_addip_enable (sctp_globals.addip_enable) 247 #define sctp_prsctp_enable (sctp_globals.prsctp_enable) 248 249 /* SCTP Socket type: UDP or TCP style. */ 250 typedef enum { 251 SCTP_SOCKET_UDP = 0, 252 SCTP_SOCKET_UDP_HIGH_BANDWIDTH, 253 SCTP_SOCKET_TCP 254 } sctp_socket_type_t; 255 256 /* Per socket SCTP information. */ 257 struct sctp_sock { 258 /* inet_sock has to be the first member of sctp_sock */ 259 struct inet_sock inet; 260 /* What kind of a socket is this? */ 261 sctp_socket_type_t type; 262 263 /* PF_ family specific functions. */ 264 struct sctp_pf *pf; 265 266 /* Access to HMAC transform. */ 267 struct crypto_tfm *hmac; 268 269 /* What is our base endpointer? */ 270 struct sctp_endpoint *ep; 271 272 struct sctp_bind_bucket *bind_hash; 273 /* Various Socket Options. */ 274 __u16 default_stream; 275 __u32 default_ppid; 276 __u16 default_flags; 277 __u32 default_context; 278 __u32 default_timetolive; 279 280 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 281 * the destination address every heartbeat interval. This value 282 * will be inherited by all new associations. 283 */ 284 __u32 hbinterval; 285 286 /* This is the max_retrans value for new associations. */ 287 __u16 pathmaxrxt; 288 289 /* The initial Path MTU to use for new associations. */ 290 __u32 pathmtu; 291 292 /* The default SACK delay timeout for new associations. */ 293 __u32 sackdelay; 294 295 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 296 __u32 param_flags; 297 298 struct sctp_initmsg initmsg; 299 struct sctp_rtoinfo rtoinfo; 300 struct sctp_paddrparams paddrparam; 301 struct sctp_event_subscribe subscribe; 302 struct sctp_assocparams assocparams; 303 int user_frag; 304 __u32 autoclose; 305 __u8 nodelay; 306 __u8 disable_fragments; 307 __u8 pd_mode; 308 __u8 v4mapped; 309 __u32 adaption_ind; 310 311 /* Receive to here while partial delivery is in effect. */ 312 struct sk_buff_head pd_lobby; 313 }; 314 315 static inline struct sctp_sock *sctp_sk(const struct sock *sk) 316 { 317 return (struct sctp_sock *)sk; 318 } 319 320 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp) 321 { 322 return (struct sock *)sp; 323 } 324 325 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 326 struct sctp6_sock { 327 struct sctp_sock sctp; 328 struct ipv6_pinfo inet6; 329 }; 330 #endif /* CONFIG_IPV6 */ 331 332 333 /* This is our APPLICATION-SPECIFIC state cookie. 334 * THIS IS NOT DICTATED BY THE SPECIFICATION. 335 */ 336 /* These are the parts of an association which we send in the cookie. 337 * Most of these are straight out of: 338 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB) 339 * 340 */ 341 342 struct sctp_cookie { 343 344 /* My : Tag expected in every inbound packet and sent 345 * Verification: in the INIT or INIT ACK chunk. 346 * Tag : 347 */ 348 __u32 my_vtag; 349 350 /* Peer's : Tag expected in every outbound packet except 351 * Verification: in the INIT chunk. 352 * Tag : 353 */ 354 __u32 peer_vtag; 355 356 /* The rest of these are not from the spec, but really need to 357 * be in the cookie. 358 */ 359 360 /* My Tie Tag : Assist in discovering a restarting association. */ 361 __u32 my_ttag; 362 363 /* Peer's Tie Tag: Assist in discovering a restarting association. */ 364 __u32 peer_ttag; 365 366 /* When does this cookie expire? */ 367 struct timeval expiration; 368 369 /* Number of inbound/outbound streams which are set 370 * and negotiated during the INIT process. 371 */ 372 __u16 sinit_num_ostreams; 373 __u16 sinit_max_instreams; 374 375 /* This is the first sequence number I used. */ 376 __u32 initial_tsn; 377 378 /* This holds the originating address of the INIT packet. */ 379 union sctp_addr peer_addr; 380 381 /* IG Section 2.35.3 382 * Include the source port of the INIT-ACK 383 */ 384 __u16 my_port; 385 386 __u8 prsctp_capable; 387 388 /* Padding for future use */ 389 __u8 padding; 390 391 __u32 adaption_ind; 392 393 394 /* This is a shim for my peer's INIT packet, followed by 395 * a copy of the raw address list of the association. 396 * The length of the raw address list is saved in the 397 * raw_addr_list_len field, which will be used at the time when 398 * the association TCB is re-constructed from the cookie. 399 */ 400 __u32 raw_addr_list_len; 401 struct sctp_init_chunk peer_init[0]; 402 }; 403 404 405 /* The format of our cookie that we send to our peer. */ 406 struct sctp_signed_cookie { 407 __u8 signature[SCTP_SECRET_SIZE]; 408 __u32 __pad; /* force sctp_cookie alignment to 64 bits */ 409 struct sctp_cookie c; 410 } __attribute__((packed)); 411 412 /* This is another convenience type to allocate memory for address 413 * params for the maximum size and pass such structures around 414 * internally. 415 */ 416 union sctp_addr_param { 417 struct sctp_ipv4addr_param v4; 418 struct sctp_ipv6addr_param v6; 419 }; 420 421 /* A convenience type to allow walking through the various 422 * parameters and avoid casting all over the place. 423 */ 424 union sctp_params { 425 void *v; 426 struct sctp_paramhdr *p; 427 struct sctp_cookie_preserve_param *life; 428 struct sctp_hostname_param *dns; 429 struct sctp_cookie_param *cookie; 430 struct sctp_supported_addrs_param *sat; 431 struct sctp_ipv4addr_param *v4; 432 struct sctp_ipv6addr_param *v6; 433 union sctp_addr_param *addr; 434 struct sctp_adaption_ind_param *aind; 435 }; 436 437 /* RFC 2960. Section 3.3.5 Heartbeat. 438 * Heartbeat Information: variable length 439 * The Sender-specific Heartbeat Info field should normally include 440 * information about the sender's current time when this HEARTBEAT 441 * chunk is sent and the destination transport address to which this 442 * HEARTBEAT is sent (see Section 8.3). 443 */ 444 typedef struct sctp_sender_hb_info { 445 struct sctp_paramhdr param_hdr; 446 union sctp_addr daddr; 447 unsigned long sent_at; 448 } __attribute__((packed)) sctp_sender_hb_info_t; 449 450 /* 451 * RFC 2960 1.3.2 Sequenced Delivery within Streams 452 * 453 * The term "stream" is used in SCTP to refer to a sequence of user 454 * messages that are to be delivered to the upper-layer protocol in 455 * order with respect to other messages within the same stream. This is 456 * in contrast to its usage in TCP, where it refers to a sequence of 457 * bytes (in this document a byte is assumed to be eight bits). 458 * ... 459 * 460 * This is the structure we use to track both our outbound and inbound 461 * SSN, or Stream Sequence Numbers. 462 */ 463 464 struct sctp_stream { 465 __u16 *ssn; 466 unsigned int len; 467 }; 468 469 struct sctp_ssnmap { 470 struct sctp_stream in; 471 struct sctp_stream out; 472 int malloced; 473 }; 474 475 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, 476 gfp_t gfp); 477 void sctp_ssnmap_free(struct sctp_ssnmap *map); 478 void sctp_ssnmap_clear(struct sctp_ssnmap *map); 479 480 /* What is the current SSN number for this stream? */ 481 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id) 482 { 483 return stream->ssn[id]; 484 } 485 486 /* Return the next SSN number for this stream. */ 487 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id) 488 { 489 return stream->ssn[id]++; 490 } 491 492 /* Skip over this ssn and all below. */ 493 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, 494 __u16 ssn) 495 { 496 stream->ssn[id] = ssn+1; 497 } 498 499 /* 500 * Pointers to address related SCTP functions. 501 * (i.e. things that depend on the address family.) 502 */ 503 struct sctp_af { 504 int (*sctp_xmit) (struct sk_buff *skb, 505 struct sctp_transport *, 506 int ipfragok); 507 int (*setsockopt) (struct sock *sk, 508 int level, 509 int optname, 510 char __user *optval, 511 int optlen); 512 int (*getsockopt) (struct sock *sk, 513 int level, 514 int optname, 515 char __user *optval, 516 int __user *optlen); 517 struct dst_entry *(*get_dst) (struct sctp_association *asoc, 518 union sctp_addr *daddr, 519 union sctp_addr *saddr); 520 void (*get_saddr) (struct sctp_association *asoc, 521 struct dst_entry *dst, 522 union sctp_addr *daddr, 523 union sctp_addr *saddr); 524 void (*copy_addrlist) (struct list_head *, 525 struct net_device *); 526 void (*dst_saddr) (union sctp_addr *saddr, 527 struct dst_entry *dst, 528 unsigned short port); 529 int (*cmp_addr) (const union sctp_addr *addr1, 530 const union sctp_addr *addr2); 531 void (*addr_copy) (union sctp_addr *dst, 532 union sctp_addr *src); 533 void (*from_skb) (union sctp_addr *, 534 struct sk_buff *skb, 535 int saddr); 536 void (*from_sk) (union sctp_addr *, 537 struct sock *sk); 538 void (*to_sk_saddr) (union sctp_addr *, 539 struct sock *sk); 540 void (*to_sk_daddr) (union sctp_addr *, 541 struct sock *sk); 542 void (*from_addr_param) (union sctp_addr *, 543 union sctp_addr_param *, 544 __u16 port, int iif); 545 int (*to_addr_param) (const union sctp_addr *, 546 union sctp_addr_param *); 547 int (*addr_valid) (union sctp_addr *, 548 struct sctp_sock *); 549 sctp_scope_t (*scope) (union sctp_addr *); 550 void (*inaddr_any) (union sctp_addr *, unsigned short); 551 int (*is_any) (const union sctp_addr *); 552 int (*available) (union sctp_addr *, 553 struct sctp_sock *); 554 int (*skb_iif) (const struct sk_buff *sk); 555 int (*is_ce) (const struct sk_buff *sk); 556 void (*seq_dump_addr)(struct seq_file *seq, 557 union sctp_addr *addr); 558 __u16 net_header_len; 559 int sockaddr_len; 560 sa_family_t sa_family; 561 struct list_head list; 562 }; 563 564 struct sctp_af *sctp_get_af_specific(sa_family_t); 565 int sctp_register_af(struct sctp_af *); 566 567 /* Protocol family functions. */ 568 struct sctp_pf { 569 void (*event_msgname)(struct sctp_ulpevent *, char *, int *); 570 void (*skb_msgname) (struct sk_buff *, char *, int *); 571 int (*af_supported) (sa_family_t, struct sctp_sock *); 572 int (*cmp_addr) (const union sctp_addr *, 573 const union sctp_addr *, 574 struct sctp_sock *); 575 int (*bind_verify) (struct sctp_sock *, union sctp_addr *); 576 int (*send_verify) (struct sctp_sock *, union sctp_addr *); 577 int (*supported_addrs)(const struct sctp_sock *, __u16 *); 578 struct sock *(*create_accept_sk) (struct sock *sk, 579 struct sctp_association *asoc); 580 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *); 581 struct sctp_af *af; 582 }; 583 584 585 /* Structure to track chunk fragments that have been acked, but peer 586 * fragments of the same message have not. 587 */ 588 struct sctp_datamsg { 589 /* Chunks waiting to be submitted to lower layer. */ 590 struct list_head chunks; 591 /* Chunks that have been transmitted. */ 592 struct list_head track; 593 /* Reference counting. */ 594 atomic_t refcnt; 595 /* When is this message no longer interesting to the peer? */ 596 unsigned long expires_at; 597 /* Did the messenge fail to send? */ 598 int send_error; 599 char send_failed; 600 /* Control whether chunks from this message can be abandoned. */ 601 char can_abandon; 602 }; 603 604 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, 605 struct sctp_sndrcvinfo *, 606 struct msghdr *, int len); 607 void sctp_datamsg_put(struct sctp_datamsg *); 608 void sctp_datamsg_free(struct sctp_datamsg *); 609 void sctp_datamsg_track(struct sctp_chunk *); 610 void sctp_chunk_fail(struct sctp_chunk *, int error); 611 int sctp_chunk_abandoned(struct sctp_chunk *); 612 613 /* RFC2960 1.4 Key Terms 614 * 615 * o Chunk: A unit of information within an SCTP packet, consisting of 616 * a chunk header and chunk-specific content. 617 * 618 * As a matter of convenience, we remember the SCTP common header for 619 * each chunk as well as a few other header pointers... 620 */ 621 struct sctp_chunk { 622 struct list_head list; 623 624 atomic_t refcnt; 625 626 /* This is our link to the per-transport transmitted list. */ 627 struct list_head transmitted_list; 628 629 /* This field is used by chunks that hold fragmented data. 630 * For the first fragment this is the list that holds the rest of 631 * fragments. For the remaining fragments, this is the link to the 632 * frag_list maintained in the first fragment. 633 */ 634 struct list_head frag_list; 635 636 /* This points to the sk_buff containing the actual data. */ 637 struct sk_buff *skb; 638 639 /* These are the SCTP headers by reverse order in a packet. 640 * Note that some of these may happen more than once. In that 641 * case, we point at the "current" one, whatever that means 642 * for that level of header. 643 */ 644 645 /* We point this at the FIRST TLV parameter to chunk_hdr. */ 646 union sctp_params param_hdr; 647 union { 648 __u8 *v; 649 struct sctp_datahdr *data_hdr; 650 struct sctp_inithdr *init_hdr; 651 struct sctp_sackhdr *sack_hdr; 652 struct sctp_heartbeathdr *hb_hdr; 653 struct sctp_sender_hb_info *hbs_hdr; 654 struct sctp_shutdownhdr *shutdown_hdr; 655 struct sctp_signed_cookie *cookie_hdr; 656 struct sctp_ecnehdr *ecne_hdr; 657 struct sctp_cwrhdr *ecn_cwr_hdr; 658 struct sctp_errhdr *err_hdr; 659 struct sctp_addiphdr *addip_hdr; 660 struct sctp_fwdtsn_hdr *fwdtsn_hdr; 661 } subh; 662 663 __u8 *chunk_end; 664 665 struct sctp_chunkhdr *chunk_hdr; 666 struct sctphdr *sctp_hdr; 667 668 /* This needs to be recoverable for SCTP_SEND_FAILED events. */ 669 struct sctp_sndrcvinfo sinfo; 670 671 /* Which association does this belong to? */ 672 struct sctp_association *asoc; 673 674 /* What endpoint received this chunk? */ 675 struct sctp_ep_common *rcvr; 676 677 /* We fill this in if we are calculating RTT. */ 678 unsigned long sent_at; 679 680 /* What is the origin IP address for this chunk? */ 681 union sctp_addr source; 682 /* Destination address for this chunk. */ 683 union sctp_addr dest; 684 685 /* For outbound message, track all fragments for SEND_FAILED. */ 686 struct sctp_datamsg *msg; 687 688 /* For an inbound chunk, this tells us where it came from. 689 * For an outbound chunk, it tells us where we'd like it to 690 * go. It is NULL if we have no preference. 691 */ 692 struct sctp_transport *transport; 693 694 __u8 rtt_in_progress; /* Is this chunk used for RTT calculation? */ 695 __u8 resent; /* Has this chunk ever been retransmitted. */ 696 __u8 has_tsn; /* Does this chunk have a TSN yet? */ 697 __u8 has_ssn; /* Does this chunk have a SSN yet? */ 698 __u8 singleton; /* Was this the only chunk in the packet? */ 699 __u8 end_of_packet; /* Was this the last chunk in the packet? */ 700 __u8 ecn_ce_done; /* Have we processed the ECN CE bit? */ 701 __u8 pdiscard; /* Discard the whole packet now? */ 702 __u8 tsn_gap_acked; /* Is this chunk acked by a GAP ACK? */ 703 __s8 fast_retransmit; /* Is this chunk fast retransmitted? */ 704 __u8 tsn_missing_report; /* Data chunk missing counter. */ 705 }; 706 707 void sctp_chunk_hold(struct sctp_chunk *); 708 void sctp_chunk_put(struct sctp_chunk *); 709 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 710 struct iovec *data); 711 void sctp_chunk_free(struct sctp_chunk *); 712 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); 713 struct sctp_chunk *sctp_chunkify(struct sk_buff *, 714 const struct sctp_association *, 715 struct sock *); 716 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, 717 union sctp_addr *); 718 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); 719 720 /* This is a structure for holding either an IPv6 or an IPv4 address. */ 721 /* sin_family -- AF_INET or AF_INET6 722 * sin_port -- ordinary port number 723 * sin_addr -- cast to either (struct in_addr) or (struct in6_addr) 724 */ 725 struct sctp_sockaddr_entry { 726 struct list_head list; 727 union sctp_addr a; 728 }; 729 730 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *); 731 732 /* This structure holds lists of chunks as we are assembling for 733 * transmission. 734 */ 735 struct sctp_packet { 736 /* These are the SCTP header values (host order) for the packet. */ 737 __u16 source_port; 738 __u16 destination_port; 739 __u32 vtag; 740 741 /* This contains the payload chunks. */ 742 struct list_head chunk_list; 743 744 /* This is the overhead of the sctp and ip headers. */ 745 size_t overhead; 746 /* This is the total size of all chunks INCLUDING padding. */ 747 size_t size; 748 749 /* The packet is destined for this transport address. 750 * The function we finally use to pass down to the next lower 751 * layer lives in the transport structure. 752 */ 753 struct sctp_transport *transport; 754 755 /* This packet contains a COOKIE-ECHO chunk. */ 756 char has_cookie_echo; 757 758 /* This packet containsa SACK chunk. */ 759 char has_sack; 760 761 /* SCTP cannot fragment this packet. So let ip fragment it. */ 762 char ipfragok; 763 764 int malloced; 765 }; 766 767 struct sctp_packet *sctp_packet_init(struct sctp_packet *, 768 struct sctp_transport *, 769 __u16 sport, __u16 dport); 770 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int); 771 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *, 772 struct sctp_chunk *); 773 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *, 774 struct sctp_chunk *); 775 int sctp_packet_transmit(struct sctp_packet *); 776 void sctp_packet_free(struct sctp_packet *); 777 778 static inline int sctp_packet_empty(struct sctp_packet *packet) 779 { 780 return (packet->size == packet->overhead); 781 } 782 783 /* This represents a remote transport address. 784 * For local transport addresses, we just use union sctp_addr. 785 * 786 * RFC2960 Section 1.4 Key Terms 787 * 788 * o Transport address: A Transport Address is traditionally defined 789 * by Network Layer address, Transport Layer protocol and Transport 790 * Layer port number. In the case of SCTP running over IP, a 791 * transport address is defined by the combination of an IP address 792 * and an SCTP port number (where SCTP is the Transport protocol). 793 * 794 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control 795 * 796 * o The sender keeps a separate congestion control parameter set for 797 * each of the destination addresses it can send to (not each 798 * source-destination pair but for each destination). The parameters 799 * should decay if the address is not used for a long enough time 800 * period. 801 * 802 */ 803 struct sctp_transport { 804 /* A list of transports. */ 805 struct list_head transports; 806 807 /* Reference counting. */ 808 atomic_t refcnt; 809 int dead; 810 811 /* This is the peer's IP address and port. */ 812 union sctp_addr ipaddr; 813 814 /* These are the functions we call to handle LLP stuff. */ 815 struct sctp_af *af_specific; 816 817 /* Which association do we belong to? */ 818 struct sctp_association *asoc; 819 820 /* RFC2960 821 * 822 * 12.3 Per Transport Address Data 823 * 824 * For each destination transport address in the peer's 825 * address list derived from the INIT or INIT ACK chunk, a 826 * number of data elements needs to be maintained including: 827 */ 828 __u32 rtt; /* This is the most recent RTT. */ 829 830 /* RTO : The current retransmission timeout value. */ 831 unsigned long rto; 832 833 /* RTTVAR : The current RTT variation. */ 834 __u32 rttvar; 835 836 /* SRTT : The current smoothed round trip time. */ 837 __u32 srtt; 838 839 /* RTO-Pending : A flag used to track if one of the DATA 840 * chunks sent to this address is currently being 841 * used to compute a RTT. If this flag is 0, 842 * the next DATA chunk sent to this destination 843 * should be used to compute a RTT and this flag 844 * should be set. Every time the RTT 845 * calculation completes (i.e. the DATA chunk 846 * is SACK'd) clear this flag. 847 */ 848 int rto_pending; 849 850 /* 851 * These are the congestion stats. 852 */ 853 /* cwnd : The current congestion window. */ 854 __u32 cwnd; /* This is the actual cwnd. */ 855 856 /* ssthresh : The current slow start threshold value. */ 857 __u32 ssthresh; 858 859 /* partial : The tracking method for increase of cwnd when in 860 * bytes acked : congestion avoidance mode (see Section 6.2.2) 861 */ 862 __u32 partial_bytes_acked; 863 864 /* Data that has been sent, but not acknowledged. */ 865 __u32 flight_size; 866 867 /* Destination */ 868 struct dst_entry *dst; 869 /* Source address. */ 870 union sctp_addr saddr; 871 872 /* When was the last time(in jiffies) that a data packet was sent on 873 * this transport? This is used to adjust the cwnd when the transport 874 * becomes inactive. 875 */ 876 unsigned long last_time_used; 877 878 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 879 * the destination address every heartbeat interval. 880 */ 881 unsigned long hbinterval; 882 883 /* SACK delay timeout */ 884 unsigned long sackdelay; 885 886 /* When was the last time (in jiffies) that we heard from this 887 * transport? We use this to pick new active and retran paths. 888 */ 889 unsigned long last_time_heard; 890 891 /* Last time(in jiffies) when cwnd is reduced due to the congestion 892 * indication based on ECNE chunk. 893 */ 894 unsigned long last_time_ecne_reduced; 895 896 /* This is the max_retrans value for the transport and will 897 * be initialized from the assocs value. This can be changed 898 * using SCTP_SET_PEER_ADDR_PARAMS socket option. 899 */ 900 __u16 pathmaxrxt; 901 902 /* PMTU : The current known path MTU. */ 903 __u32 pathmtu; 904 905 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 906 __u32 param_flags; 907 908 /* The number of times INIT has been sent on this transport. */ 909 int init_sent_count; 910 911 /* state : The current state of this destination, 912 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKOWN. 913 */ 914 int state; 915 916 /* These are the error stats for this destination. */ 917 918 /* Error count : The current error count for this destination. */ 919 unsigned short error_count; 920 921 /* Per : A timer used by each destination. 922 * Destination : 923 * Timer : 924 * 925 * [Everywhere else in the text this is called T3-rtx. -ed] 926 */ 927 struct timer_list T3_rtx_timer; 928 929 /* Heartbeat timer is per destination. */ 930 struct timer_list hb_timer; 931 932 /* Since we're using per-destination retransmission timers 933 * (see above), we're also using per-destination "transmitted" 934 * queues. This probably ought to be a private struct 935 * accessible only within the outqueue, but it's not, yet. 936 */ 937 struct list_head transmitted; 938 939 /* We build bundle-able packets for this transport here. */ 940 struct sctp_packet packet; 941 942 /* This is the list of transports that have chunks to send. */ 943 struct list_head send_ready; 944 945 int malloced; /* Is this structure kfree()able? */ 946 947 /* State information saved for SFR_CACC algorithm. The key 948 * idea in SFR_CACC is to maintain state at the sender on a 949 * per-destination basis when a changeover happens. 950 * char changeover_active; 951 * char cycling_changeover; 952 * __u32 next_tsn_at_change; 953 * char cacc_saw_newack; 954 */ 955 struct { 956 /* An unsigned integer, which stores the next TSN to be 957 * used by the sender, at the moment of changeover. 958 */ 959 __u32 next_tsn_at_change; 960 961 /* A flag which indicates the occurrence of a changeover */ 962 char changeover_active; 963 964 /* A flag which indicates whether the change of primary is 965 * the first switch to this destination address during an 966 * active switch. 967 */ 968 char cycling_changeover; 969 970 /* A temporary flag, which is used during the processing of 971 * a SACK to estimate the causative TSN(s)'s group. 972 */ 973 char cacc_saw_newack; 974 } cacc; 975 }; 976 977 struct sctp_transport *sctp_transport_new(const union sctp_addr *, 978 gfp_t); 979 void sctp_transport_set_owner(struct sctp_transport *, 980 struct sctp_association *); 981 void sctp_transport_route(struct sctp_transport *, union sctp_addr *, 982 struct sctp_sock *); 983 void sctp_transport_pmtu(struct sctp_transport *); 984 void sctp_transport_free(struct sctp_transport *); 985 void sctp_transport_reset_timers(struct sctp_transport *); 986 void sctp_transport_hold(struct sctp_transport *); 987 void sctp_transport_put(struct sctp_transport *); 988 void sctp_transport_update_rto(struct sctp_transport *, __u32); 989 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32); 990 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t); 991 unsigned long sctp_transport_timeout(struct sctp_transport *); 992 993 994 /* This is the structure we use to queue packets as they come into 995 * SCTP. We write packets to it and read chunks from it. 996 */ 997 struct sctp_inq { 998 /* This is actually a queue of sctp_chunk each 999 * containing a partially decoded packet. 1000 */ 1001 struct list_head in_chunk_list; 1002 /* This is the packet which is currently off the in queue and is 1003 * being worked on through the inbound chunk processing. 1004 */ 1005 struct sctp_chunk *in_progress; 1006 1007 /* This is the delayed task to finish delivering inbound 1008 * messages. 1009 */ 1010 struct work_struct immediate; 1011 1012 int malloced; /* Is this structure kfree()able? */ 1013 }; 1014 1015 void sctp_inq_init(struct sctp_inq *); 1016 void sctp_inq_free(struct sctp_inq *); 1017 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet); 1018 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *); 1019 void sctp_inq_set_th_handler(struct sctp_inq *, void (*)(void *), void *); 1020 1021 /* This is the structure we use to hold outbound chunks. You push 1022 * chunks in and they automatically pop out the other end as bundled 1023 * packets (it calls (*output_handler)()). 1024 * 1025 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1, 1026 * and 8.2 of the v13 draft. 1027 * 1028 * It handles retransmissions. The connection to the timeout portion 1029 * of the state machine is through sctp_..._timeout() and timeout_handler. 1030 * 1031 * If you feed it SACKs, it will eat them. 1032 * 1033 * If you give it big chunks, it will fragment them. 1034 * 1035 * It assigns TSN's to data chunks. This happens at the last possible 1036 * instant before transmission. 1037 * 1038 * When free()'d, it empties itself out via output_handler(). 1039 */ 1040 struct sctp_outq { 1041 struct sctp_association *asoc; 1042 1043 /* Data pending that has never been transmitted. */ 1044 struct list_head out_chunk_list; 1045 1046 unsigned out_qlen; /* Total length of queued data chunks. */ 1047 1048 /* Error of send failed, may used in SCTP_SEND_FAILED event. */ 1049 unsigned error; 1050 1051 /* These are control chunks we want to send. */ 1052 struct list_head control_chunk_list; 1053 1054 /* These are chunks that have been sacked but are above the 1055 * CTSN, or cumulative tsn ack point. 1056 */ 1057 struct list_head sacked; 1058 1059 /* Put chunks on this list to schedule them for 1060 * retransmission. 1061 */ 1062 struct list_head retransmit; 1063 1064 /* Put chunks on this list to save them for FWD TSN processing as 1065 * they were abandoned. 1066 */ 1067 struct list_head abandoned; 1068 1069 /* How many unackd bytes do we have in-flight? */ 1070 __u32 outstanding_bytes; 1071 1072 /* Corked? */ 1073 char cork; 1074 1075 /* Is this structure empty? */ 1076 char empty; 1077 1078 /* Are we kfree()able? */ 1079 char malloced; 1080 }; 1081 1082 void sctp_outq_init(struct sctp_association *, struct sctp_outq *); 1083 void sctp_outq_teardown(struct sctp_outq *); 1084 void sctp_outq_free(struct sctp_outq*); 1085 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk); 1086 int sctp_outq_flush(struct sctp_outq *, int); 1087 int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *); 1088 int sctp_outq_is_empty(const struct sctp_outq *); 1089 void sctp_outq_restart(struct sctp_outq *); 1090 1091 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *, 1092 sctp_retransmit_reason_t); 1093 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); 1094 int sctp_outq_uncork(struct sctp_outq *); 1095 /* Uncork and flush an outqueue. */ 1096 static inline void sctp_outq_cork(struct sctp_outq *q) 1097 { 1098 q->cork = 1; 1099 } 1100 1101 /* These bind address data fields common between endpoints and associations */ 1102 struct sctp_bind_addr { 1103 1104 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1105 * 1106 * SCTP Port: The local SCTP port number the endpoint is 1107 * bound to. 1108 */ 1109 __u16 port; 1110 1111 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1112 * 1113 * Address List: The list of IP addresses that this instance 1114 * has bound. This information is passed to one's 1115 * peer(s) in INIT and INIT ACK chunks. 1116 */ 1117 struct list_head address_list; 1118 1119 int malloced; /* Are we kfree()able? */ 1120 }; 1121 1122 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port); 1123 void sctp_bind_addr_free(struct sctp_bind_addr *); 1124 int sctp_bind_addr_copy(struct sctp_bind_addr *dest, 1125 const struct sctp_bind_addr *src, 1126 sctp_scope_t scope, gfp_t gfp, 1127 int flags); 1128 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1129 gfp_t gfp); 1130 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *); 1131 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, 1132 struct sctp_sock *); 1133 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 1134 const union sctp_addr *addrs, 1135 int addrcnt, 1136 struct sctp_sock *opt); 1137 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 1138 int *addrs_len, 1139 gfp_t gfp); 1140 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, 1141 __u16 port, gfp_t gfp); 1142 1143 sctp_scope_t sctp_scope(const union sctp_addr *); 1144 int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope); 1145 int sctp_is_any(const union sctp_addr *addr); 1146 int sctp_addr_is_valid(const union sctp_addr *addr); 1147 1148 1149 /* What type of endpoint? */ 1150 typedef enum { 1151 SCTP_EP_TYPE_SOCKET, 1152 SCTP_EP_TYPE_ASSOCIATION, 1153 } sctp_endpoint_type_t; 1154 1155 /* 1156 * A common base class to bridge the implmentation view of a 1157 * socket (usually listening) endpoint versus an association's 1158 * local endpoint. 1159 * This common structure is useful for several purposes: 1160 * 1) Common interface for lookup routines. 1161 * a) Subfunctions work for either endpoint or association 1162 * b) Single interface to lookup allows hiding the lookup lock rather 1163 * than acquiring it externally. 1164 * 2) Common interface for the inbound chunk handling/state machine. 1165 * 3) Common object handling routines for reference counting, etc. 1166 * 4) Disentangle association lookup from endpoint lookup, where we 1167 * do not have to find our endpoint to find our association. 1168 * 1169 */ 1170 1171 struct sctp_ep_common { 1172 /* Fields to help us manage our entries in the hash tables. */ 1173 struct sctp_ep_common *next; 1174 struct sctp_ep_common **pprev; 1175 int hashent; 1176 1177 /* Runtime type information. What kind of endpoint is this? */ 1178 sctp_endpoint_type_t type; 1179 1180 /* Some fields to help us manage this object. 1181 * refcnt - Reference count access to this object. 1182 * dead - Do not attempt to use this object. 1183 * malloced - Do we need to kfree this object? 1184 */ 1185 atomic_t refcnt; 1186 char dead; 1187 char malloced; 1188 1189 /* What socket does this endpoint belong to? */ 1190 struct sock *sk; 1191 1192 /* This is where we receive inbound chunks. */ 1193 struct sctp_inq inqueue; 1194 1195 /* This substructure includes the defining parameters of the 1196 * endpoint: 1197 * bind_addr.port is our shared port number. 1198 * bind_addr.address_list is our set of local IP addresses. 1199 */ 1200 struct sctp_bind_addr bind_addr; 1201 1202 /* Protection during address list comparisons. */ 1203 rwlock_t addr_lock; 1204 }; 1205 1206 1207 /* RFC Section 1.4 Key Terms 1208 * 1209 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a 1210 * multi-homed host, an SCTP endpoint is represented to its peers as a 1211 * combination of a set of eligible destination transport addresses to 1212 * which SCTP packets can be sent and a set of eligible source 1213 * transport addresses from which SCTP packets can be received. 1214 * All transport addresses used by an SCTP endpoint must use the 1215 * same port number, but can use multiple IP addresses. A transport 1216 * address used by an SCTP endpoint must not be used by another 1217 * SCTP endpoint. In other words, a transport address is unique 1218 * to an SCTP endpoint. 1219 * 1220 * From an implementation perspective, each socket has one of these. 1221 * A TCP-style socket will have exactly one association on one of 1222 * these. An UDP-style socket will have multiple associations hanging 1223 * off one of these. 1224 */ 1225 1226 struct sctp_endpoint { 1227 /* Common substructure for endpoint and association. */ 1228 struct sctp_ep_common base; 1229 1230 /* Associations: A list of current associations and mappings 1231 * to the data consumers for each association. This 1232 * may be in the form of a hash table or other 1233 * implementation dependent structure. The data 1234 * consumers may be process identification 1235 * information such as file descriptors, named pipe 1236 * pointer, or table pointers dependent on how SCTP 1237 * is implemented. 1238 */ 1239 /* This is really a list of struct sctp_association entries. */ 1240 struct list_head asocs; 1241 1242 /* Secret Key: A secret key used by this endpoint to compute 1243 * the MAC. This SHOULD be a cryptographic quality 1244 * random number with a sufficient length. 1245 * Discussion in [RFC1750] can be helpful in 1246 * selection of the key. 1247 */ 1248 __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE]; 1249 int current_key; 1250 int last_key; 1251 int key_changed_at; 1252 1253 /* digest: This is a digest of the sctp cookie. This field is 1254 * only used on the receive path when we try to validate 1255 * that the cookie has not been tampered with. We put 1256 * this here so we pre-allocate this once and can re-use 1257 * on every receive. 1258 */ 1259 __u8 digest[SCTP_SIGNATURE_SIZE]; 1260 1261 /* sendbuf acct. policy. */ 1262 __u32 sndbuf_policy; 1263 1264 /* rcvbuf acct. policy. */ 1265 __u32 rcvbuf_policy; 1266 }; 1267 1268 /* Recover the outter endpoint structure. */ 1269 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) 1270 { 1271 struct sctp_endpoint *ep; 1272 1273 ep = container_of(base, struct sctp_endpoint, base); 1274 return ep; 1275 } 1276 1277 /* These are function signatures for manipulating endpoints. */ 1278 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t); 1279 void sctp_endpoint_free(struct sctp_endpoint *); 1280 void sctp_endpoint_put(struct sctp_endpoint *); 1281 void sctp_endpoint_hold(struct sctp_endpoint *); 1282 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); 1283 struct sctp_association *sctp_endpoint_lookup_assoc( 1284 const struct sctp_endpoint *ep, 1285 const union sctp_addr *paddr, 1286 struct sctp_transport **); 1287 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *, 1288 const union sctp_addr *); 1289 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *, 1290 const union sctp_addr *); 1291 int sctp_has_association(const union sctp_addr *laddr, 1292 const union sctp_addr *paddr); 1293 1294 int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t, 1295 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk, 1296 struct sctp_chunk **err_chunk); 1297 int sctp_process_init(struct sctp_association *, sctp_cid_t cid, 1298 const union sctp_addr *peer, 1299 sctp_init_chunk_t *init, gfp_t gfp); 1300 __u32 sctp_generate_tag(const struct sctp_endpoint *); 1301 __u32 sctp_generate_tsn(const struct sctp_endpoint *); 1302 1303 1304 /* RFC2960 1305 * 1306 * 12. Recommended Transmission Control Block (TCB) Parameters 1307 * 1308 * This section details a recommended set of parameters that should 1309 * be contained within the TCB for an implementation. This section is 1310 * for illustrative purposes and should not be deemed as requirements 1311 * on an implementation or as an exhaustive list of all parameters 1312 * inside an SCTP TCB. Each implementation may need its own additional 1313 * parameters for optimization. 1314 */ 1315 1316 1317 /* Here we have information about each individual association. */ 1318 struct sctp_association { 1319 1320 /* A base structure common to endpoint and association. 1321 * In this context, it represents the associations's view 1322 * of the local endpoint of the association. 1323 */ 1324 struct sctp_ep_common base; 1325 1326 /* Associations on the same socket. */ 1327 struct list_head asocs; 1328 1329 /* association id. */ 1330 sctp_assoc_t assoc_id; 1331 1332 /* This is our parent endpoint. */ 1333 struct sctp_endpoint *ep; 1334 1335 /* These are those association elements needed in the cookie. */ 1336 struct sctp_cookie c; 1337 1338 /* This is all information about our peer. */ 1339 struct { 1340 /* rwnd 1341 * 1342 * Peer Rwnd : Current calculated value of the peer's rwnd. 1343 */ 1344 __u32 rwnd; 1345 1346 /* transport_addr_list 1347 * 1348 * Peer : A list of SCTP transport addresses that the 1349 * Transport : peer is bound to. This information is derived 1350 * Address : from the INIT or INIT ACK and is used to 1351 * List : associate an inbound packet with a given 1352 * : association. Normally this information is 1353 * : hashed or keyed for quick lookup and access 1354 * : of the TCB. 1355 * : The list is also initialized with the list 1356 * : of addresses passed with the sctp_connectx() 1357 * : call. 1358 * 1359 * It is a list of SCTP_transport's. 1360 */ 1361 struct list_head transport_addr_list; 1362 1363 /* transport_count 1364 * 1365 * Peer : A count of the number of peer addresses 1366 * Transport : in the Peer Transport Address List. 1367 * Address : 1368 * Count : 1369 */ 1370 __u16 transport_count; 1371 1372 /* port 1373 * The transport layer port number. 1374 */ 1375 __u16 port; 1376 1377 /* primary_path 1378 * 1379 * Primary : This is the current primary destination 1380 * Path : transport address of the peer endpoint. It 1381 * : may also specify a source transport address 1382 * : on this endpoint. 1383 * 1384 * All of these paths live on transport_addr_list. 1385 * 1386 * At the bakeoffs, we discovered that the intent of 1387 * primaryPath is that it only changes when the ULP 1388 * asks to have it changed. We add the activePath to 1389 * designate the connection we are currently using to 1390 * transmit new data and most control chunks. 1391 */ 1392 struct sctp_transport *primary_path; 1393 1394 /* Cache the primary path address here, when we 1395 * need a an address for msg_name. 1396 */ 1397 union sctp_addr primary_addr; 1398 1399 /* active_path 1400 * The path that we are currently using to 1401 * transmit new data and most control chunks. 1402 */ 1403 struct sctp_transport *active_path; 1404 1405 /* retran_path 1406 * 1407 * RFC2960 6.4 Multi-homed SCTP Endpoints 1408 * ... 1409 * Furthermore, when its peer is multi-homed, an 1410 * endpoint SHOULD try to retransmit a chunk to an 1411 * active destination transport address that is 1412 * different from the last destination address to 1413 * which the DATA chunk was sent. 1414 */ 1415 struct sctp_transport *retran_path; 1416 1417 /* Pointer to last transport I have sent on. */ 1418 struct sctp_transport *last_sent_to; 1419 1420 /* This is the last transport I have received DATA on. */ 1421 struct sctp_transport *last_data_from; 1422 1423 /* 1424 * Mapping An array of bits or bytes indicating which out of 1425 * Array order TSN's have been received (relative to the 1426 * Last Rcvd TSN). If no gaps exist, i.e. no out of 1427 * order packets have been received, this array 1428 * will be set to all zero. This structure may be 1429 * in the form of a circular buffer or bit array. 1430 * 1431 * Last Rcvd : This is the last TSN received in 1432 * TSN : sequence. This value is set initially by 1433 * : taking the peer's Initial TSN, received in 1434 * : the INIT or INIT ACK chunk, and subtracting 1435 * : one from it. 1436 * 1437 * Throughout most of the specification this is called the 1438 * "Cumulative TSN ACK Point". In this case, we 1439 * ignore the advice in 12.2 in favour of the term 1440 * used in the bulk of the text. This value is hidden 1441 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). 1442 */ 1443 struct sctp_tsnmap tsn_map; 1444 __u8 _map[sctp_tsnmap_storage_size(SCTP_TSN_MAP_SIZE)]; 1445 1446 /* Ack State : This flag indicates if the next received 1447 * : packet is to be responded to with a 1448 * : SACK. This is initializedto 0. When a packet 1449 * : is received it is incremented. If this value 1450 * : reaches 2 or more, a SACK is sent and the 1451 * : value is reset to 0. Note: This is used only 1452 * : when no DATA chunks are received out of 1453 * : order. When DATA chunks are out of order, 1454 * : SACK's are not delayed (see Section 6). 1455 */ 1456 __u8 sack_needed; /* Do we need to sack the peer? */ 1457 1458 /* These are capabilities which our peer advertised. */ 1459 __u8 ecn_capable; /* Can peer do ECN? */ 1460 __u8 ipv4_address; /* Peer understands IPv4 addresses? */ 1461 __u8 ipv6_address; /* Peer understands IPv6 addresses? */ 1462 __u8 hostname_address;/* Peer understands DNS addresses? */ 1463 __u8 asconf_capable; /* Does peer support ADDIP? */ 1464 __u8 prsctp_capable; /* Can peer do PR-SCTP? */ 1465 1466 __u32 adaption_ind; /* Adaption Code point. */ 1467 1468 /* This mask is used to disable sending the ASCONF chunk 1469 * with specified parameter to peer. 1470 */ 1471 __u16 addip_disabled_mask; 1472 1473 struct sctp_inithdr i; 1474 int cookie_len; 1475 void *cookie; 1476 1477 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1478 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the 1479 * Initial TSN Value minus 1 1480 */ 1481 __u32 addip_serial; 1482 } peer; 1483 1484 /* State : A state variable indicating what state the 1485 * : association is in, i.e. COOKIE-WAIT, 1486 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, 1487 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. 1488 * 1489 * Note: No "CLOSED" state is illustrated since if a 1490 * association is "CLOSED" its TCB SHOULD be removed. 1491 * 1492 * In this implementation we DO have a CLOSED 1493 * state which is used during initiation and shutdown. 1494 * 1495 * State takes values from SCTP_STATE_*. 1496 */ 1497 sctp_state_t state; 1498 1499 /* The cookie life I award for any cookie. */ 1500 struct timeval cookie_life; 1501 1502 /* Overall : The overall association error count. 1503 * Error Count : [Clear this any time I get something.] 1504 */ 1505 int overall_error_count; 1506 1507 /* These are the association's initial, max, and min RTO values. 1508 * These values will be initialized by system defaults, but can 1509 * be modified via the SCTP_RTOINFO socket option. 1510 */ 1511 unsigned long rto_initial; 1512 unsigned long rto_max; 1513 unsigned long rto_min; 1514 1515 /* Maximum number of new data packets that can be sent in a burst. */ 1516 int max_burst; 1517 1518 /* This is the max_retrans value for the association. This value will 1519 * be initialized initialized from system defaults, but can be 1520 * modified by the SCTP_ASSOCINFO socket option. 1521 */ 1522 int max_retrans; 1523 1524 /* Maximum number of times the endpoint will retransmit INIT */ 1525 __u16 max_init_attempts; 1526 1527 /* How many times have we resent an INIT? */ 1528 __u16 init_retries; 1529 1530 /* The largest timeout or RTO value to use in attempting an INIT */ 1531 unsigned long max_init_timeo; 1532 1533 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 1534 * the destination address every heartbeat interval. This value 1535 * will be inherited by all new transports. 1536 */ 1537 unsigned long hbinterval; 1538 1539 /* This is the max_retrans value for new transports in the 1540 * association. 1541 */ 1542 __u16 pathmaxrxt; 1543 1544 /* Association : The smallest PMTU discovered for all of the 1545 * PMTU : peer's transport addresses. 1546 */ 1547 __u32 pathmtu; 1548 1549 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 1550 __u32 param_flags; 1551 1552 /* SACK delay timeout */ 1553 unsigned long sackdelay; 1554 1555 1556 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1557 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; 1558 1559 /* Transport to which SHUTDOWN chunk was last sent. */ 1560 struct sctp_transport *shutdown_last_sent_to; 1561 1562 /* Transport to which INIT chunk was last sent. */ 1563 struct sctp_transport *init_last_sent_to; 1564 1565 /* Next TSN : The next TSN number to be assigned to a new 1566 * : DATA chunk. This is sent in the INIT or INIT 1567 * : ACK chunk to the peer and incremented each 1568 * : time a DATA chunk is assigned a TSN 1569 * : (normally just prior to transmit or during 1570 * : fragmentation). 1571 */ 1572 __u32 next_tsn; 1573 1574 /* 1575 * Last Rcvd : This is the last TSN received in sequence. This value 1576 * TSN : is set initially by taking the peer's Initial TSN, 1577 * : received in the INIT or INIT ACK chunk, and 1578 * : subtracting one from it. 1579 * 1580 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. 1581 */ 1582 1583 __u32 ctsn_ack_point; 1584 1585 /* PR-SCTP Advanced.Peer.Ack.Point */ 1586 __u32 adv_peer_ack_point; 1587 1588 /* Highest TSN that is acknowledged by incoming SACKs. */ 1589 __u32 highest_sacked; 1590 1591 /* The number of unacknowledged data chunks. Reported through 1592 * the SCTP_STATUS sockopt. 1593 */ 1594 __u16 unack_data; 1595 1596 /* This is the association's receive buffer space. This value is used 1597 * to set a_rwnd field in an INIT or a SACK chunk. 1598 */ 1599 __u32 rwnd; 1600 1601 /* This is the last advertised value of rwnd over a SACK chunk. */ 1602 __u32 a_rwnd; 1603 1604 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed 1605 * to slop over a maximum of the association's frag_point. 1606 */ 1607 __u32 rwnd_over; 1608 1609 /* This is the sndbuf size in use for the association. 1610 * This corresponds to the sndbuf size for the association, 1611 * as specified in the sk->sndbuf. 1612 */ 1613 int sndbuf_used; 1614 1615 /* This is the amount of memory that this association has allocated 1616 * in the receive path at any given time. 1617 */ 1618 atomic_t rmem_alloc; 1619 1620 /* This is the wait queue head for send requests waiting on 1621 * the association sndbuf space. 1622 */ 1623 wait_queue_head_t wait; 1624 1625 /* The message size at which SCTP fragmentation will occur. */ 1626 __u32 frag_point; 1627 1628 /* Counter used to count INIT errors. */ 1629 int init_err_counter; 1630 1631 /* Count the number of INIT cycles (for doubling timeout). */ 1632 int init_cycle; 1633 1634 /* Default send parameters. */ 1635 __u16 default_stream; 1636 __u16 default_flags; 1637 __u32 default_ppid; 1638 __u32 default_context; 1639 __u32 default_timetolive; 1640 1641 /* This tracks outbound ssn for a given stream. */ 1642 struct sctp_ssnmap *ssnmap; 1643 1644 /* All outbound chunks go through this structure. */ 1645 struct sctp_outq outqueue; 1646 1647 /* A smart pipe that will handle reordering and fragmentation, 1648 * as well as handle passing events up to the ULP. 1649 */ 1650 struct sctp_ulpq ulpq; 1651 1652 /* Last TSN that caused an ECNE Chunk to be sent. */ 1653 __u32 last_ecne_tsn; 1654 1655 /* Last TSN that caused a CWR Chunk to be sent. */ 1656 __u32 last_cwr_tsn; 1657 1658 /* How many duplicated TSNs have we seen? */ 1659 int numduptsns; 1660 1661 /* Number of seconds of idle time before an association is closed. 1662 * In the association context, this is really used as a boolean 1663 * since the real timeout is stored in the timeouts array 1664 */ 1665 __u32 autoclose; 1666 1667 /* These are to support 1668 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses 1669 * and Enforcement of Flow and Message Limits" 1670 * <draft-ietf-tsvwg-addip-sctp-02.txt> 1671 * or "ADDIP" for short. 1672 */ 1673 1674 1675 1676 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1677 * 1678 * R1) One and only one ASCONF Chunk MAY be in transit and 1679 * unacknowledged at any one time. If a sender, after sending 1680 * an ASCONF chunk, decides it needs to transfer another 1681 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1682 * returns from the previous ASCONF Chunk before sending a 1683 * subsequent ASCONF. Note this restriction binds each side, 1684 * so at any time two ASCONF may be in-transit on any given 1685 * association (one sent from each endpoint). 1686 * 1687 * [This is our one-and-only-one ASCONF in flight. If we do 1688 * not have an ASCONF in flight, this is NULL.] 1689 */ 1690 struct sctp_chunk *addip_last_asconf; 1691 1692 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1693 * 1694 * IMPLEMENTATION NOTE: As an optimization a receiver may wish 1695 * to save the last ASCONF-ACK for some predetermined period 1696 * of time and instead of re-processing the ASCONF (with the 1697 * same serial number) it may just re-transmit the 1698 * ASCONF-ACK. It may wish to use the arrival of a new serial 1699 * number to discard the previously saved ASCONF-ACK or any 1700 * other means it may choose to expire the saved ASCONF-ACK. 1701 * 1702 * [This is our saved ASCONF-ACK. We invalidate it when a new 1703 * ASCONF serial number arrives.] 1704 */ 1705 struct sctp_chunk *addip_last_asconf_ack; 1706 1707 /* These ASCONF chunks are waiting to be sent. 1708 * 1709 * These chunaks can't be pushed to outqueue until receiving 1710 * ASCONF_ACK for the previous ASCONF indicated by 1711 * addip_last_asconf, so as to guarantee that only one ASCONF 1712 * is in flight at any time. 1713 * 1714 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1715 * 1716 * In defining the ASCONF Chunk transfer procedures, it is 1717 * essential that these transfers MUST NOT cause congestion 1718 * within the network. To achieve this, we place these 1719 * restrictions on the transfer of ASCONF Chunks: 1720 * 1721 * R1) One and only one ASCONF Chunk MAY be in transit and 1722 * unacknowledged at any one time. If a sender, after sending 1723 * an ASCONF chunk, decides it needs to transfer another 1724 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1725 * returns from the previous ASCONF Chunk before sending a 1726 * subsequent ASCONF. Note this restriction binds each side, 1727 * so at any time two ASCONF may be in-transit on any given 1728 * association (one sent from each endpoint). 1729 * 1730 * 1731 * [I really think this is EXACTLY the sort of intelligence 1732 * which already resides in sctp_outq. Please move this 1733 * queue and its supporting logic down there. --piggy] 1734 */ 1735 struct list_head addip_chunk_list; 1736 1737 /* ADDIP Section 4.1 ASCONF Chunk Procedures 1738 * 1739 * A2) A serial number should be assigned to the Chunk. The 1740 * serial number SHOULD be a monotonically increasing 1741 * number. The serial number SHOULD be initialized at 1742 * the start of the association to the same value as the 1743 * Initial TSN and every time a new ASCONF chunk is created 1744 * it is incremented by one after assigning the serial number 1745 * to the newly created chunk. 1746 * 1747 * ADDIP 1748 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) 1749 * 1750 * Serial Number : 32 bits (unsigned integer) 1751 * 1752 * This value represents a Serial Number for the ASCONF 1753 * Chunk. The valid range of Serial Number is from 0 to 1754 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 1755 * after reaching 4294967295. 1756 */ 1757 __u32 addip_serial; 1758 1759 /* Need to send an ECNE Chunk? */ 1760 char need_ecne; 1761 1762 /* Is it a temporary association? */ 1763 char temp; 1764 }; 1765 1766 1767 /* An eyecatcher for determining if we are really looking at an 1768 * association data structure. 1769 */ 1770 enum { 1771 SCTP_ASSOC_EYECATCHER = 0xa550c123, 1772 }; 1773 1774 /* Recover the outter association structure. */ 1775 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) 1776 { 1777 struct sctp_association *asoc; 1778 1779 asoc = container_of(base, struct sctp_association, base); 1780 return asoc; 1781 } 1782 1783 /* These are function signatures for manipulating associations. */ 1784 1785 1786 struct sctp_association * 1787 sctp_association_new(const struct sctp_endpoint *, const struct sock *, 1788 sctp_scope_t scope, gfp_t gfp); 1789 void sctp_association_free(struct sctp_association *); 1790 void sctp_association_put(struct sctp_association *); 1791 void sctp_association_hold(struct sctp_association *); 1792 1793 struct sctp_transport *sctp_assoc_choose_init_transport( 1794 struct sctp_association *); 1795 struct sctp_transport *sctp_assoc_choose_shutdown_transport( 1796 struct sctp_association *); 1797 void sctp_assoc_update_retran_path(struct sctp_association *); 1798 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, 1799 const union sctp_addr *); 1800 int sctp_assoc_lookup_laddr(struct sctp_association *asoc, 1801 const union sctp_addr *laddr); 1802 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, 1803 const union sctp_addr *address, 1804 const gfp_t gfp, 1805 const int peer_state); 1806 void sctp_assoc_del_peer(struct sctp_association *asoc, 1807 const union sctp_addr *addr); 1808 void sctp_assoc_rm_peer(struct sctp_association *asoc, 1809 struct sctp_transport *peer); 1810 void sctp_assoc_control_transport(struct sctp_association *, 1811 struct sctp_transport *, 1812 sctp_transport_cmd_t, sctp_sn_error_t); 1813 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); 1814 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *, 1815 const union sctp_addr *, 1816 const union sctp_addr *); 1817 void sctp_assoc_migrate(struct sctp_association *, struct sock *); 1818 void sctp_assoc_update(struct sctp_association *old, 1819 struct sctp_association *new); 1820 1821 __u32 sctp_association_get_next_tsn(struct sctp_association *); 1822 1823 void sctp_assoc_sync_pmtu(struct sctp_association *); 1824 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned); 1825 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned); 1826 void sctp_assoc_set_primary(struct sctp_association *, 1827 struct sctp_transport *); 1828 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *, 1829 gfp_t); 1830 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, 1831 struct sctp_cookie*, 1832 gfp_t gfp); 1833 1834 int sctp_cmp_addr_exact(const union sctp_addr *ss1, 1835 const union sctp_addr *ss2); 1836 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); 1837 1838 /* A convenience structure to parse out SCTP specific CMSGs. */ 1839 typedef struct sctp_cmsgs { 1840 struct sctp_initmsg *init; 1841 struct sctp_sndrcvinfo *info; 1842 } sctp_cmsgs_t; 1843 1844 /* Structure for tracking memory objects */ 1845 typedef struct { 1846 char *label; 1847 atomic_t *counter; 1848 } sctp_dbg_objcnt_entry_t; 1849 1850 #endif /* __sctp_structs_h__ */ 1851