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