1 /* SCTP kernel reference Implementation 2 * (C) Copyright IBM Corp. 2001, 2004 3 * Copyright (c) 1999-2000 Cisco, Inc. 4 * Copyright (c) 1999-2001 Motorola, Inc. 5 * Copyright (c) 2001 Intel Corp. 6 * 7 * This file is part of the SCTP kernel reference Implementation 8 * 9 * The SCTP reference implementation is free software; 10 * you can redistribute it and/or modify it under the terms of 11 * the GNU General Public License as published by 12 * the Free Software Foundation; either version 2, or (at your option) 13 * any later version. 14 * 15 * The SCTP reference implementation is distributed in the hope that it 16 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 17 * ************************ 18 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 19 * See the GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with GNU CC; see the file COPYING. If not, write to 23 * the Free Software Foundation, 59 Temple Place - Suite 330, 24 * Boston, MA 02111-1307, USA. 25 * 26 * Please send any bug reports or fixes you make to the 27 * email addresses: 28 * lksctp developers <lksctp-developers@lists.sourceforge.net> 29 * 30 * Or submit a bug report through the following website: 31 * http://www.sf.net/projects/lksctp 32 * 33 * Written or modified by: 34 * Randall Stewart <randall@sctp.chicago.il.us> 35 * Ken Morneau <kmorneau@cisco.com> 36 * Qiaobing Xie <qxie1@email.mot.com> 37 * La Monte H.P. Yarroll <piggy@acm.org> 38 * Karl Knutson <karl@athena.chicago.il.us> 39 * Jon Grimm <jgrimm@us.ibm.com> 40 * Xingang Guo <xingang.guo@intel.com> 41 * Hui Huang <hui.huang@nokia.com> 42 * Sridhar Samudrala <sri@us.ibm.com> 43 * Daisy Chang <daisyc@us.ibm.com> 44 * Dajiang Zhang <dajiang.zhang@nokia.com> 45 * Ardelle Fan <ardelle.fan@intel.com> 46 * Ryan Layer <rmlayer@us.ibm.com> 47 * Anup Pemmaiah <pemmaiah@cc.usu.edu> 48 * Kevin Gao <kevin.gao@intel.com> 49 * 50 * Any bugs reported given to us we will try to fix... any fixes shared will 51 * be incorporated into the next SCTP release. 52 */ 53 54 #ifndef __sctp_structs_h__ 55 #define __sctp_structs_h__ 56 57 #include <linux/time.h> /* We get struct timespec. */ 58 #include <linux/socket.h> /* linux/in.h needs this!! */ 59 #include <linux/in.h> /* We get struct sockaddr_in. */ 60 #include <linux/in6.h> /* We get struct in6_addr */ 61 #include <linux/ipv6.h> 62 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */ 63 #include <asm/atomic.h> /* This gets us atomic counters. */ 64 #include <linux/skbuff.h> /* We need sk_buff_head. */ 65 #include <linux/workqueue.h> /* We need tq_struct. */ 66 #include <linux/sctp.h> /* We need sctp* header structs. */ 67 68 /* A convenience structure for handling sockaddr structures. 69 * We should wean ourselves off this. 70 */ 71 union sctp_addr { 72 struct sockaddr_in v4; 73 struct sockaddr_in6 v6; 74 struct sockaddr sa; 75 }; 76 77 /* Forward declarations for data structures. */ 78 struct sctp_globals; 79 struct sctp_endpoint; 80 struct sctp_association; 81 struct sctp_transport; 82 struct sctp_packet; 83 struct sctp_chunk; 84 struct sctp_inq; 85 struct sctp_outq; 86 struct sctp_bind_addr; 87 struct sctp_ulpq; 88 struct sctp_ep_common; 89 struct sctp_ssnmap; 90 struct crypto_hash; 91 92 93 #include <net/sctp/tsnmap.h> 94 #include <net/sctp/ulpevent.h> 95 #include <net/sctp/ulpqueue.h> 96 97 /* Structures useful for managing bind/connect. */ 98 99 struct sctp_bind_bucket { 100 unsigned short port; 101 unsigned short fastreuse; 102 struct sctp_bind_bucket *next; 103 struct sctp_bind_bucket **pprev; 104 struct hlist_head owner; 105 }; 106 107 struct sctp_bind_hashbucket { 108 spinlock_t lock; 109 struct sctp_bind_bucket *chain; 110 }; 111 112 /* Used for hashing all associations. */ 113 struct sctp_hashbucket { 114 rwlock_t lock; 115 struct sctp_ep_common *chain; 116 } __attribute__((__aligned__(8))); 117 118 119 /* The SCTP globals structure. */ 120 extern struct sctp_globals { 121 /* RFC2960 Section 14. Suggested SCTP Protocol Parameter Values 122 * 123 * The following protocol parameters are RECOMMENDED: 124 * 125 * RTO.Initial - 3 seconds 126 * RTO.Min - 1 second 127 * RTO.Max - 60 seconds 128 * RTO.Alpha - 1/8 (3 when converted to right shifts.) 129 * RTO.Beta - 1/4 (2 when converted to right shifts.) 130 */ 131 unsigned int rto_initial; 132 unsigned int rto_min; 133 unsigned int rto_max; 134 135 /* Note: rto_alpha and rto_beta are really defined as inverse 136 * powers of two to facilitate integer operations. 137 */ 138 int rto_alpha; 139 int rto_beta; 140 141 /* Max.Burst - 4 */ 142 int max_burst; 143 144 /* Whether Cookie Preservative is enabled(1) or not(0) */ 145 int cookie_preserve_enable; 146 147 /* Valid.Cookie.Life - 60 seconds */ 148 unsigned int valid_cookie_life; 149 150 /* Delayed SACK timeout 200ms default*/ 151 unsigned int sack_timeout; 152 153 /* HB.interval - 30 seconds */ 154 unsigned int hb_interval; 155 156 /* Association.Max.Retrans - 10 attempts 157 * Path.Max.Retrans - 5 attempts (per destination address) 158 * Max.Init.Retransmits - 8 attempts 159 */ 160 int max_retrans_association; 161 int max_retrans_path; 162 int max_retrans_init; 163 164 /* 165 * Policy for preforming sctp/socket accounting 166 * 0 - do socket level accounting, all assocs share sk_sndbuf 167 * 1 - do sctp accounting, each asoc may use sk_sndbuf bytes 168 */ 169 int sndbuf_policy; 170 171 /* 172 * Policy for preforming sctp/socket accounting 173 * 0 - do socket level accounting, all assocs share sk_rcvbuf 174 * 1 - do sctp accounting, each asoc may use sk_rcvbuf bytes 175 */ 176 int rcvbuf_policy; 177 178 /* The following variables are implementation specific. */ 179 180 /* Default initialization values to be applied to new associations. */ 181 __u16 max_instreams; 182 __u16 max_outstreams; 183 184 /* This is a list of groups of functions for each address 185 * family that we support. 186 */ 187 struct list_head address_families; 188 189 /* This is the hash of all endpoints. */ 190 int ep_hashsize; 191 struct sctp_hashbucket *ep_hashtable; 192 193 /* This is the hash of all associations. */ 194 int assoc_hashsize; 195 struct sctp_hashbucket *assoc_hashtable; 196 197 /* This is the sctp port control hash. */ 198 int port_hashsize; 199 int port_rover; 200 spinlock_t port_alloc_lock; /* Protects port_rover. */ 201 struct sctp_bind_hashbucket *port_hashtable; 202 203 /* This is the global local address list. 204 * We actively maintain this complete list of addresses on 205 * the system by catching address add/delete events. 206 * 207 * It is a list of sctp_sockaddr_entry. 208 */ 209 struct list_head local_addr_list; 210 211 /* Lock that protects the local_addr_list writers */ 212 spinlock_t addr_list_lock; 213 214 /* Flag to indicate if addip is enabled. */ 215 int addip_enable; 216 217 /* Flag to indicate if PR-SCTP is enabled. */ 218 int prsctp_enable; 219 } sctp_globals; 220 221 #define sctp_rto_initial (sctp_globals.rto_initial) 222 #define sctp_rto_min (sctp_globals.rto_min) 223 #define sctp_rto_max (sctp_globals.rto_max) 224 #define sctp_rto_alpha (sctp_globals.rto_alpha) 225 #define sctp_rto_beta (sctp_globals.rto_beta) 226 #define sctp_max_burst (sctp_globals.max_burst) 227 #define sctp_valid_cookie_life (sctp_globals.valid_cookie_life) 228 #define sctp_cookie_preserve_enable (sctp_globals.cookie_preserve_enable) 229 #define sctp_max_retrans_association (sctp_globals.max_retrans_association) 230 #define sctp_sndbuf_policy (sctp_globals.sndbuf_policy) 231 #define sctp_rcvbuf_policy (sctp_globals.rcvbuf_policy) 232 #define sctp_max_retrans_path (sctp_globals.max_retrans_path) 233 #define sctp_max_retrans_init (sctp_globals.max_retrans_init) 234 #define sctp_sack_timeout (sctp_globals.sack_timeout) 235 #define sctp_hb_interval (sctp_globals.hb_interval) 236 #define sctp_max_instreams (sctp_globals.max_instreams) 237 #define sctp_max_outstreams (sctp_globals.max_outstreams) 238 #define sctp_address_families (sctp_globals.address_families) 239 #define sctp_ep_hashsize (sctp_globals.ep_hashsize) 240 #define sctp_ep_hashtable (sctp_globals.ep_hashtable) 241 #define sctp_assoc_hashsize (sctp_globals.assoc_hashsize) 242 #define sctp_assoc_hashtable (sctp_globals.assoc_hashtable) 243 #define sctp_port_hashsize (sctp_globals.port_hashsize) 244 #define sctp_port_rover (sctp_globals.port_rover) 245 #define sctp_port_alloc_lock (sctp_globals.port_alloc_lock) 246 #define sctp_port_hashtable (sctp_globals.port_hashtable) 247 #define sctp_local_addr_list (sctp_globals.local_addr_list) 248 #define sctp_local_addr_lock (sctp_globals.addr_list_lock) 249 #define sctp_addip_enable (sctp_globals.addip_enable) 250 #define sctp_prsctp_enable (sctp_globals.prsctp_enable) 251 252 /* SCTP Socket type: UDP or TCP style. */ 253 typedef enum { 254 SCTP_SOCKET_UDP = 0, 255 SCTP_SOCKET_UDP_HIGH_BANDWIDTH, 256 SCTP_SOCKET_TCP 257 } sctp_socket_type_t; 258 259 /* Per socket SCTP information. */ 260 struct sctp_sock { 261 /* inet_sock has to be the first member of sctp_sock */ 262 struct inet_sock inet; 263 /* What kind of a socket is this? */ 264 sctp_socket_type_t type; 265 266 /* PF_ family specific functions. */ 267 struct sctp_pf *pf; 268 269 /* Access to HMAC transform. */ 270 struct crypto_hash *hmac; 271 272 /* What is our base endpointer? */ 273 struct sctp_endpoint *ep; 274 275 struct sctp_bind_bucket *bind_hash; 276 /* Various Socket Options. */ 277 __u16 default_stream; 278 __u32 default_ppid; 279 __u16 default_flags; 280 __u32 default_context; 281 __u32 default_timetolive; 282 __u32 default_rcv_context; 283 int max_burst; 284 285 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 286 * the destination address every heartbeat interval. This value 287 * will be inherited by all new associations. 288 */ 289 __u32 hbinterval; 290 291 /* This is the max_retrans value for new associations. */ 292 __u16 pathmaxrxt; 293 294 /* The initial Path MTU to use for new associations. */ 295 __u32 pathmtu; 296 297 /* The default SACK delay timeout for new associations. */ 298 __u32 sackdelay; 299 300 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 301 __u32 param_flags; 302 303 struct sctp_initmsg initmsg; 304 struct sctp_rtoinfo rtoinfo; 305 struct sctp_paddrparams paddrparam; 306 struct sctp_event_subscribe subscribe; 307 struct sctp_assocparams assocparams; 308 int user_frag; 309 __u32 autoclose; 310 __u8 nodelay; 311 __u8 disable_fragments; 312 __u8 v4mapped; 313 __u8 frag_interleave; 314 __u32 adaptation_ind; 315 __u32 pd_point; 316 317 atomic_t pd_mode; 318 /* Receive to here while partial delivery is in effect. */ 319 struct sk_buff_head pd_lobby; 320 }; 321 322 static inline struct sctp_sock *sctp_sk(const struct sock *sk) 323 { 324 return (struct sctp_sock *)sk; 325 } 326 327 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp) 328 { 329 return (struct sock *)sp; 330 } 331 332 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 333 struct sctp6_sock { 334 struct sctp_sock sctp; 335 struct ipv6_pinfo inet6; 336 }; 337 #endif /* CONFIG_IPV6 */ 338 339 340 /* This is our APPLICATION-SPECIFIC state cookie. 341 * THIS IS NOT DICTATED BY THE SPECIFICATION. 342 */ 343 /* These are the parts of an association which we send in the cookie. 344 * Most of these are straight out of: 345 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB) 346 * 347 */ 348 349 struct sctp_cookie { 350 351 /* My : Tag expected in every inbound packet and sent 352 * Verification: in the INIT or INIT ACK chunk. 353 * Tag : 354 */ 355 __u32 my_vtag; 356 357 /* Peer's : Tag expected in every outbound packet except 358 * Verification: in the INIT chunk. 359 * Tag : 360 */ 361 __u32 peer_vtag; 362 363 /* The rest of these are not from the spec, but really need to 364 * be in the cookie. 365 */ 366 367 /* My Tie Tag : Assist in discovering a restarting association. */ 368 __u32 my_ttag; 369 370 /* Peer's Tie Tag: Assist in discovering a restarting association. */ 371 __u32 peer_ttag; 372 373 /* When does this cookie expire? */ 374 struct timeval expiration; 375 376 /* Number of inbound/outbound streams which are set 377 * and negotiated during the INIT process. 378 */ 379 __u16 sinit_num_ostreams; 380 __u16 sinit_max_instreams; 381 382 /* This is the first sequence number I used. */ 383 __u32 initial_tsn; 384 385 /* This holds the originating address of the INIT packet. */ 386 union sctp_addr peer_addr; 387 388 /* IG Section 2.35.3 389 * Include the source port of the INIT-ACK 390 */ 391 __u16 my_port; 392 393 __u8 prsctp_capable; 394 395 /* Padding for future use */ 396 __u8 padding; 397 398 __u32 adaptation_ind; 399 400 401 /* This is a shim for my peer's INIT packet, followed by 402 * a copy of the raw address list of the association. 403 * The length of the raw address list is saved in the 404 * raw_addr_list_len field, which will be used at the time when 405 * the association TCB is re-constructed from the cookie. 406 */ 407 __u32 raw_addr_list_len; 408 struct sctp_init_chunk peer_init[0]; 409 }; 410 411 412 /* The format of our cookie that we send to our peer. */ 413 struct sctp_signed_cookie { 414 __u8 signature[SCTP_SECRET_SIZE]; 415 __u32 __pad; /* force sctp_cookie alignment to 64 bits */ 416 struct sctp_cookie c; 417 } __attribute__((packed)); 418 419 /* This is another convenience type to allocate memory for address 420 * params for the maximum size and pass such structures around 421 * internally. 422 */ 423 union sctp_addr_param { 424 struct sctp_paramhdr p; 425 struct sctp_ipv4addr_param v4; 426 struct sctp_ipv6addr_param v6; 427 }; 428 429 /* A convenience type to allow walking through the various 430 * parameters and avoid casting all over the place. 431 */ 432 union sctp_params { 433 void *v; 434 struct sctp_paramhdr *p; 435 struct sctp_cookie_preserve_param *life; 436 struct sctp_hostname_param *dns; 437 struct sctp_cookie_param *cookie; 438 struct sctp_supported_addrs_param *sat; 439 struct sctp_ipv4addr_param *v4; 440 struct sctp_ipv6addr_param *v6; 441 union sctp_addr_param *addr; 442 struct sctp_adaptation_ind_param *aind; 443 }; 444 445 /* RFC 2960. Section 3.3.5 Heartbeat. 446 * Heartbeat Information: variable length 447 * The Sender-specific Heartbeat Info field should normally include 448 * information about the sender's current time when this HEARTBEAT 449 * chunk is sent and the destination transport address to which this 450 * HEARTBEAT is sent (see Section 8.3). 451 */ 452 typedef struct sctp_sender_hb_info { 453 struct sctp_paramhdr param_hdr; 454 union sctp_addr daddr; 455 unsigned long sent_at; 456 __u64 hb_nonce; 457 } __attribute__((packed)) sctp_sender_hb_info_t; 458 459 /* 460 * RFC 2960 1.3.2 Sequenced Delivery within Streams 461 * 462 * The term "stream" is used in SCTP to refer to a sequence of user 463 * messages that are to be delivered to the upper-layer protocol in 464 * order with respect to other messages within the same stream. This is 465 * in contrast to its usage in TCP, where it refers to a sequence of 466 * bytes (in this document a byte is assumed to be eight bits). 467 * ... 468 * 469 * This is the structure we use to track both our outbound and inbound 470 * SSN, or Stream Sequence Numbers. 471 */ 472 473 struct sctp_stream { 474 __u16 *ssn; 475 unsigned int len; 476 }; 477 478 struct sctp_ssnmap { 479 struct sctp_stream in; 480 struct sctp_stream out; 481 int malloced; 482 }; 483 484 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, 485 gfp_t gfp); 486 void sctp_ssnmap_free(struct sctp_ssnmap *map); 487 void sctp_ssnmap_clear(struct sctp_ssnmap *map); 488 489 /* What is the current SSN number for this stream? */ 490 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id) 491 { 492 return stream->ssn[id]; 493 } 494 495 /* Return the next SSN number for this stream. */ 496 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id) 497 { 498 return stream->ssn[id]++; 499 } 500 501 /* Skip over this ssn and all below. */ 502 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, 503 __u16 ssn) 504 { 505 stream->ssn[id] = ssn+1; 506 } 507 508 /* 509 * Pointers to address related SCTP functions. 510 * (i.e. things that depend on the address family.) 511 */ 512 struct sctp_af { 513 int (*sctp_xmit) (struct sk_buff *skb, 514 struct sctp_transport *, 515 int ipfragok); 516 int (*setsockopt) (struct sock *sk, 517 int level, 518 int optname, 519 char __user *optval, 520 int optlen); 521 int (*getsockopt) (struct sock *sk, 522 int level, 523 int optname, 524 char __user *optval, 525 int __user *optlen); 526 int (*compat_setsockopt) (struct sock *sk, 527 int level, 528 int optname, 529 char __user *optval, 530 int optlen); 531 int (*compat_getsockopt) (struct sock *sk, 532 int level, 533 int optname, 534 char __user *optval, 535 int __user *optlen); 536 struct dst_entry *(*get_dst) (struct sctp_association *asoc, 537 union sctp_addr *daddr, 538 union sctp_addr *saddr); 539 void (*get_saddr) (struct sctp_association *asoc, 540 struct dst_entry *dst, 541 union sctp_addr *daddr, 542 union sctp_addr *saddr); 543 void (*copy_addrlist) (struct list_head *, 544 struct net_device *); 545 void (*dst_saddr) (union sctp_addr *saddr, 546 struct dst_entry *dst, 547 __be16 port); 548 int (*cmp_addr) (const union sctp_addr *addr1, 549 const union sctp_addr *addr2); 550 void (*addr_copy) (union sctp_addr *dst, 551 union sctp_addr *src); 552 void (*from_skb) (union sctp_addr *, 553 struct sk_buff *skb, 554 int saddr); 555 void (*from_sk) (union sctp_addr *, 556 struct sock *sk); 557 void (*to_sk_saddr) (union sctp_addr *, 558 struct sock *sk); 559 void (*to_sk_daddr) (union sctp_addr *, 560 struct sock *sk); 561 void (*from_addr_param) (union sctp_addr *, 562 union sctp_addr_param *, 563 __be16 port, int iif); 564 int (*to_addr_param) (const union sctp_addr *, 565 union sctp_addr_param *); 566 int (*addr_valid) (union sctp_addr *, 567 struct sctp_sock *, 568 const struct sk_buff *); 569 sctp_scope_t (*scope) (union sctp_addr *); 570 void (*inaddr_any) (union sctp_addr *, __be16); 571 int (*is_any) (const union sctp_addr *); 572 int (*available) (union sctp_addr *, 573 struct sctp_sock *); 574 int (*skb_iif) (const struct sk_buff *sk); 575 int (*is_ce) (const struct sk_buff *sk); 576 void (*seq_dump_addr)(struct seq_file *seq, 577 union sctp_addr *addr); 578 __u16 net_header_len; 579 int sockaddr_len; 580 sa_family_t sa_family; 581 struct list_head list; 582 }; 583 584 struct sctp_af *sctp_get_af_specific(sa_family_t); 585 int sctp_register_af(struct sctp_af *); 586 587 /* Protocol family functions. */ 588 struct sctp_pf { 589 void (*event_msgname)(struct sctp_ulpevent *, char *, int *); 590 void (*skb_msgname) (struct sk_buff *, char *, int *); 591 int (*af_supported) (sa_family_t, struct sctp_sock *); 592 int (*cmp_addr) (const union sctp_addr *, 593 const union sctp_addr *, 594 struct sctp_sock *); 595 int (*bind_verify) (struct sctp_sock *, union sctp_addr *); 596 int (*send_verify) (struct sctp_sock *, union sctp_addr *); 597 int (*supported_addrs)(const struct sctp_sock *, __be16 *); 598 struct sock *(*create_accept_sk) (struct sock *sk, 599 struct sctp_association *asoc); 600 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *); 601 struct sctp_af *af; 602 }; 603 604 605 /* Structure to track chunk fragments that have been acked, but peer 606 * fragments of the same message have not. 607 */ 608 struct sctp_datamsg { 609 /* Chunks waiting to be submitted to lower layer. */ 610 struct list_head chunks; 611 /* Chunks that have been transmitted. */ 612 struct list_head track; 613 /* Reference counting. */ 614 atomic_t refcnt; 615 /* When is this message no longer interesting to the peer? */ 616 unsigned long expires_at; 617 /* Did the messenge fail to send? */ 618 int send_error; 619 char send_failed; 620 /* Control whether chunks from this message can be abandoned. */ 621 char can_abandon; 622 }; 623 624 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, 625 struct sctp_sndrcvinfo *, 626 struct msghdr *, int len); 627 void sctp_datamsg_put(struct sctp_datamsg *); 628 void sctp_datamsg_free(struct sctp_datamsg *); 629 void sctp_datamsg_track(struct sctp_chunk *); 630 void sctp_chunk_fail(struct sctp_chunk *, int error); 631 int sctp_chunk_abandoned(struct sctp_chunk *); 632 633 /* RFC2960 1.4 Key Terms 634 * 635 * o Chunk: A unit of information within an SCTP packet, consisting of 636 * a chunk header and chunk-specific content. 637 * 638 * As a matter of convenience, we remember the SCTP common header for 639 * each chunk as well as a few other header pointers... 640 */ 641 struct sctp_chunk { 642 struct list_head list; 643 644 atomic_t refcnt; 645 646 /* This is our link to the per-transport transmitted list. */ 647 struct list_head transmitted_list; 648 649 /* This field is used by chunks that hold fragmented data. 650 * For the first fragment this is the list that holds the rest of 651 * fragments. For the remaining fragments, this is the link to the 652 * frag_list maintained in the first fragment. 653 */ 654 struct list_head frag_list; 655 656 /* This points to the sk_buff containing the actual data. */ 657 struct sk_buff *skb; 658 659 /* These are the SCTP headers by reverse order in a packet. 660 * Note that some of these may happen more than once. In that 661 * case, we point at the "current" one, whatever that means 662 * for that level of header. 663 */ 664 665 /* We point this at the FIRST TLV parameter to chunk_hdr. */ 666 union sctp_params param_hdr; 667 union { 668 __u8 *v; 669 struct sctp_datahdr *data_hdr; 670 struct sctp_inithdr *init_hdr; 671 struct sctp_sackhdr *sack_hdr; 672 struct sctp_heartbeathdr *hb_hdr; 673 struct sctp_sender_hb_info *hbs_hdr; 674 struct sctp_shutdownhdr *shutdown_hdr; 675 struct sctp_signed_cookie *cookie_hdr; 676 struct sctp_ecnehdr *ecne_hdr; 677 struct sctp_cwrhdr *ecn_cwr_hdr; 678 struct sctp_errhdr *err_hdr; 679 struct sctp_addiphdr *addip_hdr; 680 struct sctp_fwdtsn_hdr *fwdtsn_hdr; 681 } subh; 682 683 __u8 *chunk_end; 684 685 struct sctp_chunkhdr *chunk_hdr; 686 struct sctphdr *sctp_hdr; 687 688 /* This needs to be recoverable for SCTP_SEND_FAILED events. */ 689 struct sctp_sndrcvinfo sinfo; 690 691 /* Which association does this belong to? */ 692 struct sctp_association *asoc; 693 694 /* What endpoint received this chunk? */ 695 struct sctp_ep_common *rcvr; 696 697 /* We fill this in if we are calculating RTT. */ 698 unsigned long sent_at; 699 700 /* What is the origin IP address for this chunk? */ 701 union sctp_addr source; 702 /* Destination address for this chunk. */ 703 union sctp_addr dest; 704 705 /* For outbound message, track all fragments for SEND_FAILED. */ 706 struct sctp_datamsg *msg; 707 708 /* For an inbound chunk, this tells us where it came from. 709 * For an outbound chunk, it tells us where we'd like it to 710 * go. It is NULL if we have no preference. 711 */ 712 struct sctp_transport *transport; 713 714 __u8 rtt_in_progress; /* Is this chunk used for RTT calculation? */ 715 __u8 resent; /* Has this chunk ever been retransmitted. */ 716 __u8 has_tsn; /* Does this chunk have a TSN yet? */ 717 __u8 has_ssn; /* Does this chunk have a SSN yet? */ 718 __u8 singleton; /* Was this the only chunk in the packet? */ 719 __u8 end_of_packet; /* Was this the last chunk in the packet? */ 720 __u8 ecn_ce_done; /* Have we processed the ECN CE bit? */ 721 __u8 pdiscard; /* Discard the whole packet now? */ 722 __u8 tsn_gap_acked; /* Is this chunk acked by a GAP ACK? */ 723 __s8 fast_retransmit; /* Is this chunk fast retransmitted? */ 724 __u8 tsn_missing_report; /* Data chunk missing counter. */ 725 __u8 data_accepted; /* At least 1 chunk in this packet accepted */ 726 }; 727 728 void sctp_chunk_hold(struct sctp_chunk *); 729 void sctp_chunk_put(struct sctp_chunk *); 730 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 731 struct iovec *data); 732 void sctp_chunk_free(struct sctp_chunk *); 733 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); 734 void *sctp_addto_param(struct sctp_chunk *, int len, const void *data); 735 struct sctp_chunk *sctp_chunkify(struct sk_buff *, 736 const struct sctp_association *, 737 struct sock *); 738 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, 739 union sctp_addr *); 740 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); 741 742 /* This is a structure for holding either an IPv6 or an IPv4 address. */ 743 struct sctp_sockaddr_entry { 744 struct list_head list; 745 struct rcu_head rcu; 746 union sctp_addr a; 747 __u8 use_as_src; 748 __u8 valid; 749 }; 750 751 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *); 752 753 /* This structure holds lists of chunks as we are assembling for 754 * transmission. 755 */ 756 struct sctp_packet { 757 /* These are the SCTP header values (host order) for the packet. */ 758 __u16 source_port; 759 __u16 destination_port; 760 __u32 vtag; 761 762 /* This contains the payload chunks. */ 763 struct list_head chunk_list; 764 765 /* This is the overhead of the sctp and ip headers. */ 766 size_t overhead; 767 /* This is the total size of all chunks INCLUDING padding. */ 768 size_t size; 769 770 /* The packet is destined for this transport address. 771 * The function we finally use to pass down to the next lower 772 * layer lives in the transport structure. 773 */ 774 struct sctp_transport *transport; 775 776 /* This packet contains a COOKIE-ECHO chunk. */ 777 char has_cookie_echo; 778 779 /* This packet containsa SACK chunk. */ 780 char has_sack; 781 782 /* SCTP cannot fragment this packet. So let ip fragment it. */ 783 char ipfragok; 784 785 int malloced; 786 }; 787 788 struct sctp_packet *sctp_packet_init(struct sctp_packet *, 789 struct sctp_transport *, 790 __u16 sport, __u16 dport); 791 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int); 792 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *, 793 struct sctp_chunk *); 794 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *, 795 struct sctp_chunk *); 796 int sctp_packet_transmit(struct sctp_packet *); 797 void sctp_packet_free(struct sctp_packet *); 798 799 static inline int sctp_packet_empty(struct sctp_packet *packet) 800 { 801 return (packet->size == packet->overhead); 802 } 803 804 /* This represents a remote transport address. 805 * For local transport addresses, we just use union sctp_addr. 806 * 807 * RFC2960 Section 1.4 Key Terms 808 * 809 * o Transport address: A Transport Address is traditionally defined 810 * by Network Layer address, Transport Layer protocol and Transport 811 * Layer port number. In the case of SCTP running over IP, a 812 * transport address is defined by the combination of an IP address 813 * and an SCTP port number (where SCTP is the Transport protocol). 814 * 815 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control 816 * 817 * o The sender keeps a separate congestion control parameter set for 818 * each of the destination addresses it can send to (not each 819 * source-destination pair but for each destination). The parameters 820 * should decay if the address is not used for a long enough time 821 * period. 822 * 823 */ 824 struct sctp_transport { 825 /* A list of transports. */ 826 struct list_head transports; 827 828 /* Reference counting. */ 829 atomic_t refcnt; 830 int dead; 831 832 /* This is the peer's IP address and port. */ 833 union sctp_addr ipaddr; 834 835 /* These are the functions we call to handle LLP stuff. */ 836 struct sctp_af *af_specific; 837 838 /* Which association do we belong to? */ 839 struct sctp_association *asoc; 840 841 /* RFC2960 842 * 843 * 12.3 Per Transport Address Data 844 * 845 * For each destination transport address in the peer's 846 * address list derived from the INIT or INIT ACK chunk, a 847 * number of data elements needs to be maintained including: 848 */ 849 __u32 rtt; /* This is the most recent RTT. */ 850 851 /* RTO : The current retransmission timeout value. */ 852 unsigned long rto; 853 854 /* RTTVAR : The current RTT variation. */ 855 __u32 rttvar; 856 857 /* SRTT : The current smoothed round trip time. */ 858 __u32 srtt; 859 860 /* RTO-Pending : A flag used to track if one of the DATA 861 * chunks sent to this address is currently being 862 * used to compute a RTT. If this flag is 0, 863 * the next DATA chunk sent to this destination 864 * should be used to compute a RTT and this flag 865 * should be set. Every time the RTT 866 * calculation completes (i.e. the DATA chunk 867 * is SACK'd) clear this flag. 868 */ 869 int rto_pending; 870 871 /* 872 * These are the congestion stats. 873 */ 874 /* cwnd : The current congestion window. */ 875 __u32 cwnd; /* This is the actual cwnd. */ 876 877 /* ssthresh : The current slow start threshold value. */ 878 __u32 ssthresh; 879 880 /* partial : The tracking method for increase of cwnd when in 881 * bytes acked : congestion avoidance mode (see Section 6.2.2) 882 */ 883 __u32 partial_bytes_acked; 884 885 /* Data that has been sent, but not acknowledged. */ 886 __u32 flight_size; 887 888 /* Destination */ 889 struct dst_entry *dst; 890 /* Source address. */ 891 union sctp_addr saddr; 892 893 /* When was the last time(in jiffies) that a data packet was sent on 894 * this transport? This is used to adjust the cwnd when the transport 895 * becomes inactive. 896 */ 897 unsigned long last_time_used; 898 899 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 900 * the destination address every heartbeat interval. 901 */ 902 unsigned long hbinterval; 903 904 /* SACK delay timeout */ 905 unsigned long sackdelay; 906 907 /* When was the last time (in jiffies) that we heard from this 908 * transport? We use this to pick new active and retran paths. 909 */ 910 unsigned long last_time_heard; 911 912 /* Last time(in jiffies) when cwnd is reduced due to the congestion 913 * indication based on ECNE chunk. 914 */ 915 unsigned long last_time_ecne_reduced; 916 917 /* This is the max_retrans value for the transport and will 918 * be initialized from the assocs value. This can be changed 919 * using SCTP_SET_PEER_ADDR_PARAMS socket option. 920 */ 921 __u16 pathmaxrxt; 922 923 /* is the Path MTU update pending on this tranport */ 924 __u8 pmtu_pending; 925 926 /* PMTU : The current known path MTU. */ 927 __u32 pathmtu; 928 929 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 930 __u32 param_flags; 931 932 /* The number of times INIT has been sent on this transport. */ 933 int init_sent_count; 934 935 /* state : The current state of this destination, 936 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKOWN. 937 */ 938 int state; 939 940 /* These are the error stats for this destination. */ 941 942 /* Error count : The current error count for this destination. */ 943 unsigned short error_count; 944 945 /* Per : A timer used by each destination. 946 * Destination : 947 * Timer : 948 * 949 * [Everywhere else in the text this is called T3-rtx. -ed] 950 */ 951 struct timer_list T3_rtx_timer; 952 953 /* Heartbeat timer is per destination. */ 954 struct timer_list hb_timer; 955 956 /* Since we're using per-destination retransmission timers 957 * (see above), we're also using per-destination "transmitted" 958 * queues. This probably ought to be a private struct 959 * accessible only within the outqueue, but it's not, yet. 960 */ 961 struct list_head transmitted; 962 963 /* We build bundle-able packets for this transport here. */ 964 struct sctp_packet packet; 965 966 /* This is the list of transports that have chunks to send. */ 967 struct list_head send_ready; 968 969 int malloced; /* Is this structure kfree()able? */ 970 971 /* State information saved for SFR_CACC algorithm. The key 972 * idea in SFR_CACC is to maintain state at the sender on a 973 * per-destination basis when a changeover happens. 974 * char changeover_active; 975 * char cycling_changeover; 976 * __u32 next_tsn_at_change; 977 * char cacc_saw_newack; 978 */ 979 struct { 980 /* An unsigned integer, which stores the next TSN to be 981 * used by the sender, at the moment of changeover. 982 */ 983 __u32 next_tsn_at_change; 984 985 /* A flag which indicates the occurrence of a changeover */ 986 char changeover_active; 987 988 /* A flag which indicates whether the change of primary is 989 * the first switch to this destination address during an 990 * active switch. 991 */ 992 char cycling_changeover; 993 994 /* A temporary flag, which is used during the processing of 995 * a SACK to estimate the causative TSN(s)'s group. 996 */ 997 char cacc_saw_newack; 998 } cacc; 999 1000 /* 64-bit random number sent with heartbeat. */ 1001 __u64 hb_nonce; 1002 }; 1003 1004 struct sctp_transport *sctp_transport_new(const union sctp_addr *, 1005 gfp_t); 1006 void sctp_transport_set_owner(struct sctp_transport *, 1007 struct sctp_association *); 1008 void sctp_transport_route(struct sctp_transport *, union sctp_addr *, 1009 struct sctp_sock *); 1010 void sctp_transport_pmtu(struct sctp_transport *); 1011 void sctp_transport_free(struct sctp_transport *); 1012 void sctp_transport_reset_timers(struct sctp_transport *); 1013 void sctp_transport_hold(struct sctp_transport *); 1014 void sctp_transport_put(struct sctp_transport *); 1015 void sctp_transport_update_rto(struct sctp_transport *, __u32); 1016 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32); 1017 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t); 1018 unsigned long sctp_transport_timeout(struct sctp_transport *); 1019 void sctp_transport_reset(struct sctp_transport *); 1020 void sctp_transport_update_pmtu(struct sctp_transport *, u32); 1021 1022 1023 /* This is the structure we use to queue packets as they come into 1024 * SCTP. We write packets to it and read chunks from it. 1025 */ 1026 struct sctp_inq { 1027 /* This is actually a queue of sctp_chunk each 1028 * containing a partially decoded packet. 1029 */ 1030 struct list_head in_chunk_list; 1031 /* This is the packet which is currently off the in queue and is 1032 * being worked on through the inbound chunk processing. 1033 */ 1034 struct sctp_chunk *in_progress; 1035 1036 /* This is the delayed task to finish delivering inbound 1037 * messages. 1038 */ 1039 struct work_struct immediate; 1040 1041 int malloced; /* Is this structure kfree()able? */ 1042 }; 1043 1044 void sctp_inq_init(struct sctp_inq *); 1045 void sctp_inq_free(struct sctp_inq *); 1046 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet); 1047 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *); 1048 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t); 1049 1050 /* This is the structure we use to hold outbound chunks. You push 1051 * chunks in and they automatically pop out the other end as bundled 1052 * packets (it calls (*output_handler)()). 1053 * 1054 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1, 1055 * and 8.2 of the v13 draft. 1056 * 1057 * It handles retransmissions. The connection to the timeout portion 1058 * of the state machine is through sctp_..._timeout() and timeout_handler. 1059 * 1060 * If you feed it SACKs, it will eat them. 1061 * 1062 * If you give it big chunks, it will fragment them. 1063 * 1064 * It assigns TSN's to data chunks. This happens at the last possible 1065 * instant before transmission. 1066 * 1067 * When free()'d, it empties itself out via output_handler(). 1068 */ 1069 struct sctp_outq { 1070 struct sctp_association *asoc; 1071 1072 /* Data pending that has never been transmitted. */ 1073 struct list_head out_chunk_list; 1074 1075 unsigned out_qlen; /* Total length of queued data chunks. */ 1076 1077 /* Error of send failed, may used in SCTP_SEND_FAILED event. */ 1078 unsigned error; 1079 1080 /* These are control chunks we want to send. */ 1081 struct list_head control_chunk_list; 1082 1083 /* These are chunks that have been sacked but are above the 1084 * CTSN, or cumulative tsn ack point. 1085 */ 1086 struct list_head sacked; 1087 1088 /* Put chunks on this list to schedule them for 1089 * retransmission. 1090 */ 1091 struct list_head retransmit; 1092 1093 /* Put chunks on this list to save them for FWD TSN processing as 1094 * they were abandoned. 1095 */ 1096 struct list_head abandoned; 1097 1098 /* How many unackd bytes do we have in-flight? */ 1099 __u32 outstanding_bytes; 1100 1101 /* Corked? */ 1102 char cork; 1103 1104 /* Is this structure empty? */ 1105 char empty; 1106 1107 /* Are we kfree()able? */ 1108 char malloced; 1109 }; 1110 1111 void sctp_outq_init(struct sctp_association *, struct sctp_outq *); 1112 void sctp_outq_teardown(struct sctp_outq *); 1113 void sctp_outq_free(struct sctp_outq*); 1114 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk); 1115 int sctp_outq_flush(struct sctp_outq *, int); 1116 int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *); 1117 int sctp_outq_is_empty(const struct sctp_outq *); 1118 void sctp_outq_restart(struct sctp_outq *); 1119 1120 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *, 1121 sctp_retransmit_reason_t); 1122 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); 1123 int sctp_outq_uncork(struct sctp_outq *); 1124 /* Uncork and flush an outqueue. */ 1125 static inline void sctp_outq_cork(struct sctp_outq *q) 1126 { 1127 q->cork = 1; 1128 } 1129 1130 /* These bind address data fields common between endpoints and associations */ 1131 struct sctp_bind_addr { 1132 1133 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1134 * 1135 * SCTP Port: The local SCTP port number the endpoint is 1136 * bound to. 1137 */ 1138 __u16 port; 1139 1140 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1141 * 1142 * Address List: The list of IP addresses that this instance 1143 * has bound. This information is passed to one's 1144 * peer(s) in INIT and INIT ACK chunks. 1145 */ 1146 struct list_head address_list; 1147 1148 int malloced; /* Are we kfree()able? */ 1149 }; 1150 1151 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port); 1152 void sctp_bind_addr_free(struct sctp_bind_addr *); 1153 int sctp_bind_addr_copy(struct sctp_bind_addr *dest, 1154 const struct sctp_bind_addr *src, 1155 sctp_scope_t scope, gfp_t gfp, 1156 int flags); 1157 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1158 __u8 use_as_src, gfp_t gfp); 1159 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1160 void fastcall (*rcu_call)(struct rcu_head *, 1161 void (*func)(struct rcu_head *))); 1162 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, 1163 struct sctp_sock *); 1164 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 1165 const union sctp_addr *addrs, 1166 int addrcnt, 1167 struct sctp_sock *opt); 1168 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 1169 int *addrs_len, 1170 gfp_t gfp); 1171 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, 1172 __u16 port, gfp_t gfp); 1173 1174 sctp_scope_t sctp_scope(const union sctp_addr *); 1175 int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope); 1176 int sctp_is_any(const union sctp_addr *addr); 1177 int sctp_addr_is_valid(const union sctp_addr *addr); 1178 1179 1180 /* What type of endpoint? */ 1181 typedef enum { 1182 SCTP_EP_TYPE_SOCKET, 1183 SCTP_EP_TYPE_ASSOCIATION, 1184 } sctp_endpoint_type_t; 1185 1186 /* 1187 * A common base class to bridge the implmentation view of a 1188 * socket (usually listening) endpoint versus an association's 1189 * local endpoint. 1190 * This common structure is useful for several purposes: 1191 * 1) Common interface for lookup routines. 1192 * a) Subfunctions work for either endpoint or association 1193 * b) Single interface to lookup allows hiding the lookup lock rather 1194 * than acquiring it externally. 1195 * 2) Common interface for the inbound chunk handling/state machine. 1196 * 3) Common object handling routines for reference counting, etc. 1197 * 4) Disentangle association lookup from endpoint lookup, where we 1198 * do not have to find our endpoint to find our association. 1199 * 1200 */ 1201 1202 struct sctp_ep_common { 1203 /* Fields to help us manage our entries in the hash tables. */ 1204 struct sctp_ep_common *next; 1205 struct sctp_ep_common **pprev; 1206 int hashent; 1207 1208 /* Runtime type information. What kind of endpoint is this? */ 1209 sctp_endpoint_type_t type; 1210 1211 /* Some fields to help us manage this object. 1212 * refcnt - Reference count access to this object. 1213 * dead - Do not attempt to use this object. 1214 * malloced - Do we need to kfree this object? 1215 */ 1216 atomic_t refcnt; 1217 char dead; 1218 char malloced; 1219 1220 /* What socket does this endpoint belong to? */ 1221 struct sock *sk; 1222 1223 /* This is where we receive inbound chunks. */ 1224 struct sctp_inq inqueue; 1225 1226 /* This substructure includes the defining parameters of the 1227 * endpoint: 1228 * bind_addr.port is our shared port number. 1229 * bind_addr.address_list is our set of local IP addresses. 1230 */ 1231 struct sctp_bind_addr bind_addr; 1232 }; 1233 1234 1235 /* RFC Section 1.4 Key Terms 1236 * 1237 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a 1238 * multi-homed host, an SCTP endpoint is represented to its peers as a 1239 * combination of a set of eligible destination transport addresses to 1240 * which SCTP packets can be sent and a set of eligible source 1241 * transport addresses from which SCTP packets can be received. 1242 * All transport addresses used by an SCTP endpoint must use the 1243 * same port number, but can use multiple IP addresses. A transport 1244 * address used by an SCTP endpoint must not be used by another 1245 * SCTP endpoint. In other words, a transport address is unique 1246 * to an SCTP endpoint. 1247 * 1248 * From an implementation perspective, each socket has one of these. 1249 * A TCP-style socket will have exactly one association on one of 1250 * these. An UDP-style socket will have multiple associations hanging 1251 * off one of these. 1252 */ 1253 1254 struct sctp_endpoint { 1255 /* Common substructure for endpoint and association. */ 1256 struct sctp_ep_common base; 1257 1258 /* Associations: A list of current associations and mappings 1259 * to the data consumers for each association. This 1260 * may be in the form of a hash table or other 1261 * implementation dependent structure. The data 1262 * consumers may be process identification 1263 * information such as file descriptors, named pipe 1264 * pointer, or table pointers dependent on how SCTP 1265 * is implemented. 1266 */ 1267 /* This is really a list of struct sctp_association entries. */ 1268 struct list_head asocs; 1269 1270 /* Secret Key: A secret key used by this endpoint to compute 1271 * the MAC. This SHOULD be a cryptographic quality 1272 * random number with a sufficient length. 1273 * Discussion in [RFC1750] can be helpful in 1274 * selection of the key. 1275 */ 1276 __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE]; 1277 int current_key; 1278 int last_key; 1279 int key_changed_at; 1280 1281 /* digest: This is a digest of the sctp cookie. This field is 1282 * only used on the receive path when we try to validate 1283 * that the cookie has not been tampered with. We put 1284 * this here so we pre-allocate this once and can re-use 1285 * on every receive. 1286 */ 1287 __u8 *digest; 1288 1289 /* sendbuf acct. policy. */ 1290 __u32 sndbuf_policy; 1291 1292 /* rcvbuf acct. policy. */ 1293 __u32 rcvbuf_policy; 1294 }; 1295 1296 /* Recover the outter endpoint structure. */ 1297 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) 1298 { 1299 struct sctp_endpoint *ep; 1300 1301 ep = container_of(base, struct sctp_endpoint, base); 1302 return ep; 1303 } 1304 1305 /* These are function signatures for manipulating endpoints. */ 1306 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t); 1307 void sctp_endpoint_free(struct sctp_endpoint *); 1308 void sctp_endpoint_put(struct sctp_endpoint *); 1309 void sctp_endpoint_hold(struct sctp_endpoint *); 1310 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); 1311 struct sctp_association *sctp_endpoint_lookup_assoc( 1312 const struct sctp_endpoint *ep, 1313 const union sctp_addr *paddr, 1314 struct sctp_transport **); 1315 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *, 1316 const union sctp_addr *); 1317 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *, 1318 const union sctp_addr *); 1319 int sctp_has_association(const union sctp_addr *laddr, 1320 const union sctp_addr *paddr); 1321 1322 int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t, 1323 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk, 1324 struct sctp_chunk **err_chunk); 1325 int sctp_process_init(struct sctp_association *, sctp_cid_t cid, 1326 const union sctp_addr *peer, 1327 sctp_init_chunk_t *init, gfp_t gfp); 1328 __u32 sctp_generate_tag(const struct sctp_endpoint *); 1329 __u32 sctp_generate_tsn(const struct sctp_endpoint *); 1330 1331 struct sctp_inithdr_host { 1332 __u32 init_tag; 1333 __u32 a_rwnd; 1334 __u16 num_outbound_streams; 1335 __u16 num_inbound_streams; 1336 __u32 initial_tsn; 1337 }; 1338 1339 /* RFC2960 1340 * 1341 * 12. Recommended Transmission Control Block (TCB) Parameters 1342 * 1343 * This section details a recommended set of parameters that should 1344 * be contained within the TCB for an implementation. This section is 1345 * for illustrative purposes and should not be deemed as requirements 1346 * on an implementation or as an exhaustive list of all parameters 1347 * inside an SCTP TCB. Each implementation may need its own additional 1348 * parameters for optimization. 1349 */ 1350 1351 1352 /* Here we have information about each individual association. */ 1353 struct sctp_association { 1354 1355 /* A base structure common to endpoint and association. 1356 * In this context, it represents the associations's view 1357 * of the local endpoint of the association. 1358 */ 1359 struct sctp_ep_common base; 1360 1361 /* Associations on the same socket. */ 1362 struct list_head asocs; 1363 1364 /* association id. */ 1365 sctp_assoc_t assoc_id; 1366 1367 /* This is our parent endpoint. */ 1368 struct sctp_endpoint *ep; 1369 1370 /* These are those association elements needed in the cookie. */ 1371 struct sctp_cookie c; 1372 1373 /* This is all information about our peer. */ 1374 struct { 1375 /* rwnd 1376 * 1377 * Peer Rwnd : Current calculated value of the peer's rwnd. 1378 */ 1379 __u32 rwnd; 1380 1381 /* transport_addr_list 1382 * 1383 * Peer : A list of SCTP transport addresses that the 1384 * Transport : peer is bound to. This information is derived 1385 * Address : from the INIT or INIT ACK and is used to 1386 * List : associate an inbound packet with a given 1387 * : association. Normally this information is 1388 * : hashed or keyed for quick lookup and access 1389 * : of the TCB. 1390 * : The list is also initialized with the list 1391 * : of addresses passed with the sctp_connectx() 1392 * : call. 1393 * 1394 * It is a list of SCTP_transport's. 1395 */ 1396 struct list_head transport_addr_list; 1397 1398 /* transport_count 1399 * 1400 * Peer : A count of the number of peer addresses 1401 * Transport : in the Peer Transport Address List. 1402 * Address : 1403 * Count : 1404 */ 1405 __u16 transport_count; 1406 1407 /* port 1408 * The transport layer port number. 1409 */ 1410 __u16 port; 1411 1412 /* primary_path 1413 * 1414 * Primary : This is the current primary destination 1415 * Path : transport address of the peer endpoint. It 1416 * : may also specify a source transport address 1417 * : on this endpoint. 1418 * 1419 * All of these paths live on transport_addr_list. 1420 * 1421 * At the bakeoffs, we discovered that the intent of 1422 * primaryPath is that it only changes when the ULP 1423 * asks to have it changed. We add the activePath to 1424 * designate the connection we are currently using to 1425 * transmit new data and most control chunks. 1426 */ 1427 struct sctp_transport *primary_path; 1428 1429 /* Cache the primary path address here, when we 1430 * need a an address for msg_name. 1431 */ 1432 union sctp_addr primary_addr; 1433 1434 /* active_path 1435 * The path that we are currently using to 1436 * transmit new data and most control chunks. 1437 */ 1438 struct sctp_transport *active_path; 1439 1440 /* retran_path 1441 * 1442 * RFC2960 6.4 Multi-homed SCTP Endpoints 1443 * ... 1444 * Furthermore, when its peer is multi-homed, an 1445 * endpoint SHOULD try to retransmit a chunk to an 1446 * active destination transport address that is 1447 * different from the last destination address to 1448 * which the DATA chunk was sent. 1449 */ 1450 struct sctp_transport *retran_path; 1451 1452 /* Pointer to last transport I have sent on. */ 1453 struct sctp_transport *last_sent_to; 1454 1455 /* This is the last transport I have received DATA on. */ 1456 struct sctp_transport *last_data_from; 1457 1458 /* 1459 * Mapping An array of bits or bytes indicating which out of 1460 * Array order TSN's have been received (relative to the 1461 * Last Rcvd TSN). If no gaps exist, i.e. no out of 1462 * order packets have been received, this array 1463 * will be set to all zero. This structure may be 1464 * in the form of a circular buffer or bit array. 1465 * 1466 * Last Rcvd : This is the last TSN received in 1467 * TSN : sequence. This value is set initially by 1468 * : taking the peer's Initial TSN, received in 1469 * : the INIT or INIT ACK chunk, and subtracting 1470 * : one from it. 1471 * 1472 * Throughout most of the specification this is called the 1473 * "Cumulative TSN ACK Point". In this case, we 1474 * ignore the advice in 12.2 in favour of the term 1475 * used in the bulk of the text. This value is hidden 1476 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). 1477 */ 1478 struct sctp_tsnmap tsn_map; 1479 __u8 _map[sctp_tsnmap_storage_size(SCTP_TSN_MAP_SIZE)]; 1480 1481 /* Ack State : This flag indicates if the next received 1482 * : packet is to be responded to with a 1483 * : SACK. This is initializedto 0. When a packet 1484 * : is received it is incremented. If this value 1485 * : reaches 2 or more, a SACK is sent and the 1486 * : value is reset to 0. Note: This is used only 1487 * : when no DATA chunks are received out of 1488 * : order. When DATA chunks are out of order, 1489 * : SACK's are not delayed (see Section 6). 1490 */ 1491 __u8 sack_needed; /* Do we need to sack the peer? */ 1492 1493 /* These are capabilities which our peer advertised. */ 1494 __u8 ecn_capable; /* Can peer do ECN? */ 1495 __u8 ipv4_address; /* Peer understands IPv4 addresses? */ 1496 __u8 ipv6_address; /* Peer understands IPv6 addresses? */ 1497 __u8 hostname_address;/* Peer understands DNS addresses? */ 1498 __u8 asconf_capable; /* Does peer support ADDIP? */ 1499 __u8 prsctp_capable; /* Can peer do PR-SCTP? */ 1500 1501 __u32 adaptation_ind; /* Adaptation Code point. */ 1502 1503 /* This mask is used to disable sending the ASCONF chunk 1504 * with specified parameter to peer. 1505 */ 1506 __be16 addip_disabled_mask; 1507 1508 struct sctp_inithdr_host i; 1509 int cookie_len; 1510 void *cookie; 1511 1512 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1513 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the 1514 * Initial TSN Value minus 1 1515 */ 1516 __u32 addip_serial; 1517 } peer; 1518 1519 /* State : A state variable indicating what state the 1520 * : association is in, i.e. COOKIE-WAIT, 1521 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, 1522 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. 1523 * 1524 * Note: No "CLOSED" state is illustrated since if a 1525 * association is "CLOSED" its TCB SHOULD be removed. 1526 * 1527 * In this implementation we DO have a CLOSED 1528 * state which is used during initiation and shutdown. 1529 * 1530 * State takes values from SCTP_STATE_*. 1531 */ 1532 sctp_state_t state; 1533 1534 /* The cookie life I award for any cookie. */ 1535 struct timeval cookie_life; 1536 1537 /* Overall : The overall association error count. 1538 * Error Count : [Clear this any time I get something.] 1539 */ 1540 int overall_error_count; 1541 1542 /* These are the association's initial, max, and min RTO values. 1543 * These values will be initialized by system defaults, but can 1544 * be modified via the SCTP_RTOINFO socket option. 1545 */ 1546 unsigned long rto_initial; 1547 unsigned long rto_max; 1548 unsigned long rto_min; 1549 1550 /* Maximum number of new data packets that can be sent in a burst. */ 1551 int max_burst; 1552 1553 /* This is the max_retrans value for the association. This value will 1554 * be initialized initialized from system defaults, but can be 1555 * modified by the SCTP_ASSOCINFO socket option. 1556 */ 1557 int max_retrans; 1558 1559 /* Maximum number of times the endpoint will retransmit INIT */ 1560 __u16 max_init_attempts; 1561 1562 /* How many times have we resent an INIT? */ 1563 __u16 init_retries; 1564 1565 /* The largest timeout or RTO value to use in attempting an INIT */ 1566 unsigned long max_init_timeo; 1567 1568 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 1569 * the destination address every heartbeat interval. This value 1570 * will be inherited by all new transports. 1571 */ 1572 unsigned long hbinterval; 1573 1574 /* This is the max_retrans value for new transports in the 1575 * association. 1576 */ 1577 __u16 pathmaxrxt; 1578 1579 /* Flag that path mtu update is pending */ 1580 __u8 pmtu_pending; 1581 1582 /* Association : The smallest PMTU discovered for all of the 1583 * PMTU : peer's transport addresses. 1584 */ 1585 __u32 pathmtu; 1586 1587 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ 1588 __u32 param_flags; 1589 1590 /* SACK delay timeout */ 1591 unsigned long sackdelay; 1592 1593 1594 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1595 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; 1596 1597 /* Transport to which SHUTDOWN chunk was last sent. */ 1598 struct sctp_transport *shutdown_last_sent_to; 1599 1600 /* Transport to which INIT chunk was last sent. */ 1601 struct sctp_transport *init_last_sent_to; 1602 1603 /* Next TSN : The next TSN number to be assigned to a new 1604 * : DATA chunk. This is sent in the INIT or INIT 1605 * : ACK chunk to the peer and incremented each 1606 * : time a DATA chunk is assigned a TSN 1607 * : (normally just prior to transmit or during 1608 * : fragmentation). 1609 */ 1610 __u32 next_tsn; 1611 1612 /* 1613 * Last Rcvd : This is the last TSN received in sequence. This value 1614 * TSN : is set initially by taking the peer's Initial TSN, 1615 * : received in the INIT or INIT ACK chunk, and 1616 * : subtracting one from it. 1617 * 1618 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. 1619 */ 1620 1621 __u32 ctsn_ack_point; 1622 1623 /* PR-SCTP Advanced.Peer.Ack.Point */ 1624 __u32 adv_peer_ack_point; 1625 1626 /* Highest TSN that is acknowledged by incoming SACKs. */ 1627 __u32 highest_sacked; 1628 1629 /* The number of unacknowledged data chunks. Reported through 1630 * the SCTP_STATUS sockopt. 1631 */ 1632 __u16 unack_data; 1633 1634 /* This is the association's receive buffer space. This value is used 1635 * to set a_rwnd field in an INIT or a SACK chunk. 1636 */ 1637 __u32 rwnd; 1638 1639 /* This is the last advertised value of rwnd over a SACK chunk. */ 1640 __u32 a_rwnd; 1641 1642 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed 1643 * to slop over a maximum of the association's frag_point. 1644 */ 1645 __u32 rwnd_over; 1646 1647 /* This is the sndbuf size in use for the association. 1648 * This corresponds to the sndbuf size for the association, 1649 * as specified in the sk->sndbuf. 1650 */ 1651 int sndbuf_used; 1652 1653 /* This is the amount of memory that this association has allocated 1654 * in the receive path at any given time. 1655 */ 1656 atomic_t rmem_alloc; 1657 1658 /* This is the wait queue head for send requests waiting on 1659 * the association sndbuf space. 1660 */ 1661 wait_queue_head_t wait; 1662 1663 /* The message size at which SCTP fragmentation will occur. */ 1664 __u32 frag_point; 1665 1666 /* Counter used to count INIT errors. */ 1667 int init_err_counter; 1668 1669 /* Count the number of INIT cycles (for doubling timeout). */ 1670 int init_cycle; 1671 1672 /* Default send parameters. */ 1673 __u16 default_stream; 1674 __u16 default_flags; 1675 __u32 default_ppid; 1676 __u32 default_context; 1677 __u32 default_timetolive; 1678 1679 /* Default receive parameters */ 1680 __u32 default_rcv_context; 1681 1682 /* This tracks outbound ssn for a given stream. */ 1683 struct sctp_ssnmap *ssnmap; 1684 1685 /* All outbound chunks go through this structure. */ 1686 struct sctp_outq outqueue; 1687 1688 /* A smart pipe that will handle reordering and fragmentation, 1689 * as well as handle passing events up to the ULP. 1690 */ 1691 struct sctp_ulpq ulpq; 1692 1693 /* Last TSN that caused an ECNE Chunk to be sent. */ 1694 __u32 last_ecne_tsn; 1695 1696 /* Last TSN that caused a CWR Chunk to be sent. */ 1697 __u32 last_cwr_tsn; 1698 1699 /* How many duplicated TSNs have we seen? */ 1700 int numduptsns; 1701 1702 /* Number of seconds of idle time before an association is closed. 1703 * In the association context, this is really used as a boolean 1704 * since the real timeout is stored in the timeouts array 1705 */ 1706 __u32 autoclose; 1707 1708 /* These are to support 1709 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses 1710 * and Enforcement of Flow and Message Limits" 1711 * <draft-ietf-tsvwg-addip-sctp-02.txt> 1712 * or "ADDIP" for short. 1713 */ 1714 1715 1716 1717 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1718 * 1719 * R1) One and only one ASCONF Chunk MAY be in transit and 1720 * unacknowledged at any one time. If a sender, after sending 1721 * an ASCONF chunk, decides it needs to transfer another 1722 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1723 * returns from the previous ASCONF Chunk before sending a 1724 * subsequent ASCONF. Note this restriction binds each side, 1725 * so at any time two ASCONF may be in-transit on any given 1726 * association (one sent from each endpoint). 1727 * 1728 * [This is our one-and-only-one ASCONF in flight. If we do 1729 * not have an ASCONF in flight, this is NULL.] 1730 */ 1731 struct sctp_chunk *addip_last_asconf; 1732 1733 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1734 * 1735 * IMPLEMENTATION NOTE: As an optimization a receiver may wish 1736 * to save the last ASCONF-ACK for some predetermined period 1737 * of time and instead of re-processing the ASCONF (with the 1738 * same serial number) it may just re-transmit the 1739 * ASCONF-ACK. It may wish to use the arrival of a new serial 1740 * number to discard the previously saved ASCONF-ACK or any 1741 * other means it may choose to expire the saved ASCONF-ACK. 1742 * 1743 * [This is our saved ASCONF-ACK. We invalidate it when a new 1744 * ASCONF serial number arrives.] 1745 */ 1746 struct sctp_chunk *addip_last_asconf_ack; 1747 1748 /* These ASCONF chunks are waiting to be sent. 1749 * 1750 * These chunaks can't be pushed to outqueue until receiving 1751 * ASCONF_ACK for the previous ASCONF indicated by 1752 * addip_last_asconf, so as to guarantee that only one ASCONF 1753 * is in flight at any time. 1754 * 1755 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1756 * 1757 * In defining the ASCONF Chunk transfer procedures, it is 1758 * essential that these transfers MUST NOT cause congestion 1759 * within the network. To achieve this, we place these 1760 * restrictions on the transfer of ASCONF Chunks: 1761 * 1762 * R1) One and only one ASCONF Chunk MAY be in transit and 1763 * unacknowledged at any one time. If a sender, after sending 1764 * an ASCONF chunk, decides it needs to transfer another 1765 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1766 * returns from the previous ASCONF Chunk before sending a 1767 * subsequent ASCONF. Note this restriction binds each side, 1768 * so at any time two ASCONF may be in-transit on any given 1769 * association (one sent from each endpoint). 1770 * 1771 * 1772 * [I really think this is EXACTLY the sort of intelligence 1773 * which already resides in sctp_outq. Please move this 1774 * queue and its supporting logic down there. --piggy] 1775 */ 1776 struct list_head addip_chunk_list; 1777 1778 /* ADDIP Section 4.1 ASCONF Chunk Procedures 1779 * 1780 * A2) A serial number should be assigned to the Chunk. The 1781 * serial number SHOULD be a monotonically increasing 1782 * number. The serial number SHOULD be initialized at 1783 * the start of the association to the same value as the 1784 * Initial TSN and every time a new ASCONF chunk is created 1785 * it is incremented by one after assigning the serial number 1786 * to the newly created chunk. 1787 * 1788 * ADDIP 1789 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) 1790 * 1791 * Serial Number : 32 bits (unsigned integer) 1792 * 1793 * This value represents a Serial Number for the ASCONF 1794 * Chunk. The valid range of Serial Number is from 0 to 1795 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 1796 * after reaching 4294967295. 1797 */ 1798 __u32 addip_serial; 1799 1800 /* Need to send an ECNE Chunk? */ 1801 char need_ecne; 1802 1803 /* Is it a temporary association? */ 1804 char temp; 1805 }; 1806 1807 1808 /* An eyecatcher for determining if we are really looking at an 1809 * association data structure. 1810 */ 1811 enum { 1812 SCTP_ASSOC_EYECATCHER = 0xa550c123, 1813 }; 1814 1815 /* Recover the outter association structure. */ 1816 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) 1817 { 1818 struct sctp_association *asoc; 1819 1820 asoc = container_of(base, struct sctp_association, base); 1821 return asoc; 1822 } 1823 1824 /* These are function signatures for manipulating associations. */ 1825 1826 1827 struct sctp_association * 1828 sctp_association_new(const struct sctp_endpoint *, const struct sock *, 1829 sctp_scope_t scope, gfp_t gfp); 1830 void sctp_association_free(struct sctp_association *); 1831 void sctp_association_put(struct sctp_association *); 1832 void sctp_association_hold(struct sctp_association *); 1833 1834 struct sctp_transport *sctp_assoc_choose_init_transport( 1835 struct sctp_association *); 1836 struct sctp_transport *sctp_assoc_choose_shutdown_transport( 1837 struct sctp_association *); 1838 void sctp_assoc_update_retran_path(struct sctp_association *); 1839 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, 1840 const union sctp_addr *); 1841 int sctp_assoc_lookup_laddr(struct sctp_association *asoc, 1842 const union sctp_addr *laddr); 1843 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, 1844 const union sctp_addr *address, 1845 const gfp_t gfp, 1846 const int peer_state); 1847 void sctp_assoc_del_peer(struct sctp_association *asoc, 1848 const union sctp_addr *addr); 1849 void sctp_assoc_rm_peer(struct sctp_association *asoc, 1850 struct sctp_transport *peer); 1851 void sctp_assoc_control_transport(struct sctp_association *, 1852 struct sctp_transport *, 1853 sctp_transport_cmd_t, sctp_sn_error_t); 1854 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); 1855 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *, 1856 const union sctp_addr *, 1857 const union sctp_addr *); 1858 void sctp_assoc_migrate(struct sctp_association *, struct sock *); 1859 void sctp_assoc_update(struct sctp_association *old, 1860 struct sctp_association *new); 1861 1862 __u32 sctp_association_get_next_tsn(struct sctp_association *); 1863 1864 void sctp_assoc_sync_pmtu(struct sctp_association *); 1865 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned); 1866 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned); 1867 void sctp_assoc_set_primary(struct sctp_association *, 1868 struct sctp_transport *); 1869 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *, 1870 gfp_t); 1871 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, 1872 struct sctp_cookie*, 1873 gfp_t gfp); 1874 int sctp_assoc_set_id(struct sctp_association *, gfp_t); 1875 1876 int sctp_cmp_addr_exact(const union sctp_addr *ss1, 1877 const union sctp_addr *ss2); 1878 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); 1879 1880 /* A convenience structure to parse out SCTP specific CMSGs. */ 1881 typedef struct sctp_cmsgs { 1882 struct sctp_initmsg *init; 1883 struct sctp_sndrcvinfo *info; 1884 } sctp_cmsgs_t; 1885 1886 /* Structure for tracking memory objects */ 1887 typedef struct { 1888 char *label; 1889 atomic_t *counter; 1890 } sctp_dbg_objcnt_entry_t; 1891 1892 #endif /* __sctp_structs_h__ */ 1893