1/* SCTP kernel 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 implementation 8 * 9 * This SCTP 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 * This SCTP 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 <linux/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#include <net/sctp/auth.h> /* We need auth specific structs */ 68 69/* A convenience structure for handling sockaddr structures. 70 * We should wean ourselves off this. 71 */ 72union sctp_addr { 73 struct sockaddr_in v4; 74 struct sockaddr_in6 v6; 75 struct sockaddr sa; 76}; 77 78/* Forward declarations for data structures. */ 79struct sctp_globals; 80struct sctp_endpoint; 81struct sctp_association; 82struct sctp_transport; 83struct sctp_packet; 84struct sctp_chunk; 85struct sctp_inq; 86struct sctp_outq; 87struct sctp_bind_addr; 88struct sctp_ulpq; 89struct sctp_ep_common; 90struct sctp_ssnmap; 91struct crypto_hash; 92 93 94#include <net/sctp/tsnmap.h> 95#include <net/sctp/ulpevent.h> 96#include <net/sctp/ulpqueue.h> 97 98/* Structures useful for managing bind/connect. */ 99 100struct sctp_bind_bucket { 101 unsigned short port; 102 unsigned short fastreuse; 103 struct hlist_node node; 104 struct hlist_head owner; 105 struct net *net; 106}; 107 108struct sctp_bind_hashbucket { 109 spinlock_t lock; 110 struct hlist_head chain; 111}; 112 113/* Used for hashing all associations. */ 114struct sctp_hashbucket { 115 rwlock_t lock; 116 struct hlist_head chain; 117} __attribute__((__aligned__(8))); 118 119 120/* The SCTP globals structure. */ 121extern struct sctp_globals { 122 /* The following variables are implementation specific. */ 123 124 /* Default initialization values to be applied to new associations. */ 125 __u16 max_instreams; 126 __u16 max_outstreams; 127 128 /* This is a list of groups of functions for each address 129 * family that we support. 130 */ 131 struct list_head address_families; 132 133 /* This is the hash of all endpoints. */ 134 int ep_hashsize; 135 struct sctp_hashbucket *ep_hashtable; 136 137 /* This is the hash of all associations. */ 138 int assoc_hashsize; 139 struct sctp_hashbucket *assoc_hashtable; 140 141 /* This is the sctp port control hash. */ 142 int port_hashsize; 143 struct sctp_bind_hashbucket *port_hashtable; 144 145 /* Flag to indicate whether computing and verifying checksum 146 * is disabled. */ 147 bool checksum_disable; 148} sctp_globals; 149 150#define sctp_max_instreams (sctp_globals.max_instreams) 151#define sctp_max_outstreams (sctp_globals.max_outstreams) 152#define sctp_address_families (sctp_globals.address_families) 153#define sctp_ep_hashsize (sctp_globals.ep_hashsize) 154#define sctp_ep_hashtable (sctp_globals.ep_hashtable) 155#define sctp_assoc_hashsize (sctp_globals.assoc_hashsize) 156#define sctp_assoc_hashtable (sctp_globals.assoc_hashtable) 157#define sctp_port_hashsize (sctp_globals.port_hashsize) 158#define sctp_port_hashtable (sctp_globals.port_hashtable) 159#define sctp_checksum_disable (sctp_globals.checksum_disable) 160 161/* SCTP Socket type: UDP or TCP style. */ 162typedef enum { 163 SCTP_SOCKET_UDP = 0, 164 SCTP_SOCKET_UDP_HIGH_BANDWIDTH, 165 SCTP_SOCKET_TCP 166} sctp_socket_type_t; 167 168/* Per socket SCTP information. */ 169struct sctp_sock { 170 /* inet_sock has to be the first member of sctp_sock */ 171 struct inet_sock inet; 172 /* What kind of a socket is this? */ 173 sctp_socket_type_t type; 174 175 /* PF_ family specific functions. */ 176 struct sctp_pf *pf; 177 178 /* Access to HMAC transform. */ 179 struct crypto_hash *hmac; 180 181 /* What is our base endpointer? */ 182 struct sctp_endpoint *ep; 183 184 struct sctp_bind_bucket *bind_hash; 185 /* Various Socket Options. */ 186 __u16 default_stream; 187 __u32 default_ppid; 188 __u16 default_flags; 189 __u32 default_context; 190 __u32 default_timetolive; 191 __u32 default_rcv_context; 192 int max_burst; 193 194 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 195 * the destination address every heartbeat interval. This value 196 * will be inherited by all new associations. 197 */ 198 __u32 hbinterval; 199 200 /* This is the max_retrans value for new associations. */ 201 __u16 pathmaxrxt; 202 203 /* The initial Path MTU to use for new associations. */ 204 __u32 pathmtu; 205 206 /* The default SACK delay timeout for new associations. */ 207 __u32 sackdelay; 208 __u32 sackfreq; 209 210 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ 211 __u32 param_flags; 212 213 struct sctp_initmsg initmsg; 214 struct sctp_rtoinfo rtoinfo; 215 struct sctp_paddrparams paddrparam; 216 struct sctp_event_subscribe subscribe; 217 struct sctp_assocparams assocparams; 218 int user_frag; 219 __u32 autoclose; 220 __u8 nodelay; 221 __u8 disable_fragments; 222 __u8 v4mapped; 223 __u8 frag_interleave; 224 __u32 adaptation_ind; 225 __u32 pd_point; 226 227 atomic_t pd_mode; 228 /* Receive to here while partial delivery is in effect. */ 229 struct sk_buff_head pd_lobby; 230 struct list_head auto_asconf_list; 231 int do_auto_asconf; 232}; 233 234static inline struct sctp_sock *sctp_sk(const struct sock *sk) 235{ 236 return (struct sctp_sock *)sk; 237} 238 239static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp) 240{ 241 return (struct sock *)sp; 242} 243 244#if IS_ENABLED(CONFIG_IPV6) 245struct sctp6_sock { 246 struct sctp_sock sctp; 247 struct ipv6_pinfo inet6; 248}; 249#endif /* CONFIG_IPV6 */ 250 251 252/* This is our APPLICATION-SPECIFIC state cookie. 253 * THIS IS NOT DICTATED BY THE SPECIFICATION. 254 */ 255/* These are the parts of an association which we send in the cookie. 256 * Most of these are straight out of: 257 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB) 258 * 259 */ 260 261struct sctp_cookie { 262 263 /* My : Tag expected in every inbound packet and sent 264 * Verification: in the INIT or INIT ACK chunk. 265 * Tag : 266 */ 267 __u32 my_vtag; 268 269 /* Peer's : Tag expected in every outbound packet except 270 * Verification: in the INIT chunk. 271 * Tag : 272 */ 273 __u32 peer_vtag; 274 275 /* The rest of these are not from the spec, but really need to 276 * be in the cookie. 277 */ 278 279 /* My Tie Tag : Assist in discovering a restarting association. */ 280 __u32 my_ttag; 281 282 /* Peer's Tie Tag: Assist in discovering a restarting association. */ 283 __u32 peer_ttag; 284 285 /* When does this cookie expire? */ 286 struct timeval expiration; 287 288 /* Number of inbound/outbound streams which are set 289 * and negotiated during the INIT process. 290 */ 291 __u16 sinit_num_ostreams; 292 __u16 sinit_max_instreams; 293 294 /* This is the first sequence number I used. */ 295 __u32 initial_tsn; 296 297 /* This holds the originating address of the INIT packet. */ 298 union sctp_addr peer_addr; 299 300 /* IG Section 2.35.3 301 * Include the source port of the INIT-ACK 302 */ 303 __u16 my_port; 304 305 __u8 prsctp_capable; 306 307 /* Padding for future use */ 308 __u8 padding; 309 310 __u32 adaptation_ind; 311 312 __u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH]; 313 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2]; 314 __u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS]; 315 316 /* This is a shim for my peer's INIT packet, followed by 317 * a copy of the raw address list of the association. 318 * The length of the raw address list is saved in the 319 * raw_addr_list_len field, which will be used at the time when 320 * the association TCB is re-constructed from the cookie. 321 */ 322 __u32 raw_addr_list_len; 323 struct sctp_init_chunk peer_init[0]; 324}; 325 326 327/* The format of our cookie that we send to our peer. */ 328struct sctp_signed_cookie { 329 __u8 signature[SCTP_SECRET_SIZE]; 330 __u32 __pad; /* force sctp_cookie alignment to 64 bits */ 331 struct sctp_cookie c; 332} __packed; 333 334/* This is another convenience type to allocate memory for address 335 * params for the maximum size and pass such structures around 336 * internally. 337 */ 338union sctp_addr_param { 339 struct sctp_paramhdr p; 340 struct sctp_ipv4addr_param v4; 341 struct sctp_ipv6addr_param v6; 342}; 343 344/* A convenience type to allow walking through the various 345 * parameters and avoid casting all over the place. 346 */ 347union sctp_params { 348 void *v; 349 struct sctp_paramhdr *p; 350 struct sctp_cookie_preserve_param *life; 351 struct sctp_hostname_param *dns; 352 struct sctp_cookie_param *cookie; 353 struct sctp_supported_addrs_param *sat; 354 struct sctp_ipv4addr_param *v4; 355 struct sctp_ipv6addr_param *v6; 356 union sctp_addr_param *addr; 357 struct sctp_adaptation_ind_param *aind; 358 struct sctp_supported_ext_param *ext; 359 struct sctp_random_param *random; 360 struct sctp_chunks_param *chunks; 361 struct sctp_hmac_algo_param *hmac_algo; 362 struct sctp_addip_param *addip; 363}; 364 365/* RFC 2960. Section 3.3.5 Heartbeat. 366 * Heartbeat Information: variable length 367 * The Sender-specific Heartbeat Info field should normally include 368 * information about the sender's current time when this HEARTBEAT 369 * chunk is sent and the destination transport address to which this 370 * HEARTBEAT is sent (see Section 8.3). 371 */ 372typedef struct sctp_sender_hb_info { 373 struct sctp_paramhdr param_hdr; 374 union sctp_addr daddr; 375 unsigned long sent_at; 376 __u64 hb_nonce; 377} __packed sctp_sender_hb_info_t; 378 379/* 380 * RFC 2960 1.3.2 Sequenced Delivery within Streams 381 * 382 * The term "stream" is used in SCTP to refer to a sequence of user 383 * messages that are to be delivered to the upper-layer protocol in 384 * order with respect to other messages within the same stream. This is 385 * in contrast to its usage in TCP, where it refers to a sequence of 386 * bytes (in this document a byte is assumed to be eight bits). 387 * ... 388 * 389 * This is the structure we use to track both our outbound and inbound 390 * SSN, or Stream Sequence Numbers. 391 */ 392 393struct sctp_stream { 394 __u16 *ssn; 395 unsigned int len; 396}; 397 398struct sctp_ssnmap { 399 struct sctp_stream in; 400 struct sctp_stream out; 401 int malloced; 402}; 403 404struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, 405 gfp_t gfp); 406void sctp_ssnmap_free(struct sctp_ssnmap *map); 407void sctp_ssnmap_clear(struct sctp_ssnmap *map); 408 409/* What is the current SSN number for this stream? */ 410static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id) 411{ 412 return stream->ssn[id]; 413} 414 415/* Return the next SSN number for this stream. */ 416static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id) 417{ 418 return stream->ssn[id]++; 419} 420 421/* Skip over this ssn and all below. */ 422static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, 423 __u16 ssn) 424{ 425 stream->ssn[id] = ssn+1; 426} 427 428/* 429 * Pointers to address related SCTP functions. 430 * (i.e. things that depend on the address family.) 431 */ 432struct sctp_af { 433 int (*sctp_xmit) (struct sk_buff *skb, 434 struct sctp_transport *); 435 int (*setsockopt) (struct sock *sk, 436 int level, 437 int optname, 438 char __user *optval, 439 unsigned int optlen); 440 int (*getsockopt) (struct sock *sk, 441 int level, 442 int optname, 443 char __user *optval, 444 int __user *optlen); 445 int (*compat_setsockopt) (struct sock *sk, 446 int level, 447 int optname, 448 char __user *optval, 449 unsigned int optlen); 450 int (*compat_getsockopt) (struct sock *sk, 451 int level, 452 int optname, 453 char __user *optval, 454 int __user *optlen); 455 void (*get_dst) (struct sctp_transport *t, 456 union sctp_addr *saddr, 457 struct flowi *fl, 458 struct sock *sk); 459 void (*get_saddr) (struct sctp_sock *sk, 460 struct sctp_transport *t, 461 struct flowi *fl); 462 void (*copy_addrlist) (struct list_head *, 463 struct net_device *); 464 int (*cmp_addr) (const union sctp_addr *addr1, 465 const union sctp_addr *addr2); 466 void (*addr_copy) (union sctp_addr *dst, 467 union sctp_addr *src); 468 void (*from_skb) (union sctp_addr *, 469 struct sk_buff *skb, 470 int saddr); 471 void (*from_sk) (union sctp_addr *, 472 struct sock *sk); 473 void (*to_sk_saddr) (union sctp_addr *, 474 struct sock *sk); 475 void (*to_sk_daddr) (union sctp_addr *, 476 struct sock *sk); 477 void (*from_addr_param) (union sctp_addr *, 478 union sctp_addr_param *, 479 __be16 port, int iif); 480 int (*to_addr_param) (const union sctp_addr *, 481 union sctp_addr_param *); 482 int (*addr_valid) (union sctp_addr *, 483 struct sctp_sock *, 484 const struct sk_buff *); 485 sctp_scope_t (*scope) (union sctp_addr *); 486 void (*inaddr_any) (union sctp_addr *, __be16); 487 int (*is_any) (const union sctp_addr *); 488 int (*available) (union sctp_addr *, 489 struct sctp_sock *); 490 int (*skb_iif) (const struct sk_buff *sk); 491 int (*is_ce) (const struct sk_buff *sk); 492 void (*seq_dump_addr)(struct seq_file *seq, 493 union sctp_addr *addr); 494 void (*ecn_capable)(struct sock *sk); 495 __u16 net_header_len; 496 int sockaddr_len; 497 sa_family_t sa_family; 498 struct list_head list; 499}; 500 501struct sctp_af *sctp_get_af_specific(sa_family_t); 502int sctp_register_af(struct sctp_af *); 503 504/* Protocol family functions. */ 505struct sctp_pf { 506 void (*event_msgname)(struct sctp_ulpevent *, char *, int *); 507 void (*skb_msgname) (struct sk_buff *, char *, int *); 508 int (*af_supported) (sa_family_t, struct sctp_sock *); 509 int (*cmp_addr) (const union sctp_addr *, 510 const union sctp_addr *, 511 struct sctp_sock *); 512 int (*bind_verify) (struct sctp_sock *, union sctp_addr *); 513 int (*send_verify) (struct sctp_sock *, union sctp_addr *); 514 int (*supported_addrs)(const struct sctp_sock *, __be16 *); 515 struct sock *(*create_accept_sk) (struct sock *sk, 516 struct sctp_association *asoc); 517 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *); 518 struct sctp_af *af; 519}; 520 521 522/* Structure to track chunk fragments that have been acked, but peer 523 * fragments of the same message have not. 524 */ 525struct sctp_datamsg { 526 /* Chunks waiting to be submitted to lower layer. */ 527 struct list_head chunks; 528 /* Reference counting. */ 529 atomic_t refcnt; 530 /* When is this message no longer interesting to the peer? */ 531 unsigned long expires_at; 532 /* Did the messenge fail to send? */ 533 int send_error; 534 u8 send_failed:1, 535 can_abandon:1, /* can chunks from this message can be abandoned. */ 536 can_delay; /* should this message be Nagle delayed */ 537}; 538 539struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, 540 struct sctp_sndrcvinfo *, 541 struct msghdr *, int len); 542void sctp_datamsg_free(struct sctp_datamsg *); 543void sctp_datamsg_put(struct sctp_datamsg *); 544void sctp_chunk_fail(struct sctp_chunk *, int error); 545int sctp_chunk_abandoned(struct sctp_chunk *); 546 547/* RFC2960 1.4 Key Terms 548 * 549 * o Chunk: A unit of information within an SCTP packet, consisting of 550 * a chunk header and chunk-specific content. 551 * 552 * As a matter of convenience, we remember the SCTP common header for 553 * each chunk as well as a few other header pointers... 554 */ 555struct sctp_chunk { 556 struct list_head list; 557 558 atomic_t refcnt; 559 560 /* This is our link to the per-transport transmitted list. */ 561 struct list_head transmitted_list; 562 563 /* This field is used by chunks that hold fragmented data. 564 * For the first fragment this is the list that holds the rest of 565 * fragments. For the remaining fragments, this is the link to the 566 * frag_list maintained in the first fragment. 567 */ 568 struct list_head frag_list; 569 570 /* This points to the sk_buff containing the actual data. */ 571 struct sk_buff *skb; 572 573 /* These are the SCTP headers by reverse order in a packet. 574 * Note that some of these may happen more than once. In that 575 * case, we point at the "current" one, whatever that means 576 * for that level of header. 577 */ 578 579 /* We point this at the FIRST TLV parameter to chunk_hdr. */ 580 union sctp_params param_hdr; 581 union { 582 __u8 *v; 583 struct sctp_datahdr *data_hdr; 584 struct sctp_inithdr *init_hdr; 585 struct sctp_sackhdr *sack_hdr; 586 struct sctp_heartbeathdr *hb_hdr; 587 struct sctp_sender_hb_info *hbs_hdr; 588 struct sctp_shutdownhdr *shutdown_hdr; 589 struct sctp_signed_cookie *cookie_hdr; 590 struct sctp_ecnehdr *ecne_hdr; 591 struct sctp_cwrhdr *ecn_cwr_hdr; 592 struct sctp_errhdr *err_hdr; 593 struct sctp_addiphdr *addip_hdr; 594 struct sctp_fwdtsn_hdr *fwdtsn_hdr; 595 struct sctp_authhdr *auth_hdr; 596 } subh; 597 598 __u8 *chunk_end; 599 600 struct sctp_chunkhdr *chunk_hdr; 601 struct sctphdr *sctp_hdr; 602 603 /* This needs to be recoverable for SCTP_SEND_FAILED events. */ 604 struct sctp_sndrcvinfo sinfo; 605 606 /* Which association does this belong to? */ 607 struct sctp_association *asoc; 608 609 /* What endpoint received this chunk? */ 610 struct sctp_ep_common *rcvr; 611 612 /* We fill this in if we are calculating RTT. */ 613 unsigned long sent_at; 614 615 /* What is the origin IP address for this chunk? */ 616 union sctp_addr source; 617 /* Destination address for this chunk. */ 618 union sctp_addr dest; 619 620 /* For outbound message, track all fragments for SEND_FAILED. */ 621 struct sctp_datamsg *msg; 622 623 /* For an inbound chunk, this tells us where it came from. 624 * For an outbound chunk, it tells us where we'd like it to 625 * go. It is NULL if we have no preference. 626 */ 627 struct sctp_transport *transport; 628 629 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO 630 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH 631 * spec violates the principle premis that all chunks are processed 632 * in order. 633 */ 634 struct sk_buff *auth_chunk; 635 636#define SCTP_CAN_FRTX 0x0 637#define SCTP_NEED_FRTX 0x1 638#define SCTP_DONT_FRTX 0x2 639 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */ 640 has_tsn:1, /* Does this chunk have a TSN yet? */ 641 has_ssn:1, /* Does this chunk have a SSN yet? */ 642 singleton:1, /* Only chunk in the packet? */ 643 end_of_packet:1, /* Last chunk in the packet? */ 644 ecn_ce_done:1, /* Have we processed the ECN CE bit? */ 645 pdiscard:1, /* Discard the whole packet now? */ 646 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */ 647 data_accepted:1, /* At least 1 chunk accepted */ 648 auth:1, /* IN: was auth'ed | OUT: needs auth */ 649 has_asconf:1, /* IN: have seen an asconf before */ 650 tsn_missing_report:2, /* Data chunk missing counter. */ 651 fast_retransmit:2; /* Is this chunk fast retransmitted? */ 652}; 653 654void sctp_chunk_hold(struct sctp_chunk *); 655void sctp_chunk_put(struct sctp_chunk *); 656int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 657 struct iovec *data); 658void sctp_chunk_free(struct sctp_chunk *); 659void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); 660void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, const void *data); 661struct sctp_chunk *sctp_chunkify(struct sk_buff *, 662 const struct sctp_association *, 663 struct sock *); 664void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, 665 union sctp_addr *); 666const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); 667 668enum { 669 SCTP_ADDR_NEW, /* new address added to assoc/ep */ 670 SCTP_ADDR_SRC, /* address can be used as source */ 671 SCTP_ADDR_DEL, /* address about to be deleted */ 672}; 673 674/* This is a structure for holding either an IPv6 or an IPv4 address. */ 675struct sctp_sockaddr_entry { 676 struct list_head list; 677 struct rcu_head rcu; 678 union sctp_addr a; 679 __u8 state; 680 __u8 valid; 681}; 682 683#define SCTP_ADDRESS_TICK_DELAY 500 684 685typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *); 686 687/* This structure holds lists of chunks as we are assembling for 688 * transmission. 689 */ 690struct sctp_packet { 691 /* These are the SCTP header values (host order) for the packet. */ 692 __u16 source_port; 693 __u16 destination_port; 694 __u32 vtag; 695 696 /* This contains the payload chunks. */ 697 struct list_head chunk_list; 698 699 /* This is the overhead of the sctp and ip headers. */ 700 size_t overhead; 701 /* This is the total size of all chunks INCLUDING padding. */ 702 size_t size; 703 704 /* The packet is destined for this transport address. 705 * The function we finally use to pass down to the next lower 706 * layer lives in the transport structure. 707 */ 708 struct sctp_transport *transport; 709 710 /* pointer to the auth chunk for this packet */ 711 struct sctp_chunk *auth; 712 713 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */ 714 has_sack:1, /* This packet contains a SACK chunk. */ 715 has_auth:1, /* This packet contains an AUTH chunk */ 716 has_data:1, /* This packet contains at least 1 DATA chunk */ 717 ipfragok:1, /* So let ip fragment this packet */ 718 malloced:1; /* Is it malloced? */ 719}; 720 721struct sctp_packet *sctp_packet_init(struct sctp_packet *, 722 struct sctp_transport *, 723 __u16 sport, __u16 dport); 724struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int); 725sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *, 726 struct sctp_chunk *, int); 727sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *, 728 struct sctp_chunk *); 729int sctp_packet_transmit(struct sctp_packet *); 730void sctp_packet_free(struct sctp_packet *); 731 732static inline int sctp_packet_empty(struct sctp_packet *packet) 733{ 734 return packet->size == packet->overhead; 735} 736 737/* This represents a remote transport address. 738 * For local transport addresses, we just use union sctp_addr. 739 * 740 * RFC2960 Section 1.4 Key Terms 741 * 742 * o Transport address: A Transport Address is traditionally defined 743 * by Network Layer address, Transport Layer protocol and Transport 744 * Layer port number. In the case of SCTP running over IP, a 745 * transport address is defined by the combination of an IP address 746 * and an SCTP port number (where SCTP is the Transport protocol). 747 * 748 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control 749 * 750 * o The sender keeps a separate congestion control parameter set for 751 * each of the destination addresses it can send to (not each 752 * source-destination pair but for each destination). The parameters 753 * should decay if the address is not used for a long enough time 754 * period. 755 * 756 */ 757struct sctp_transport { 758 /* A list of transports. */ 759 struct list_head transports; 760 761 /* Reference counting. */ 762 atomic_t refcnt; 763 __u32 dead:1, 764 /* RTO-Pending : A flag used to track if one of the DATA 765 * chunks sent to this address is currently being 766 * used to compute a RTT. If this flag is 0, 767 * the next DATA chunk sent to this destination 768 * should be used to compute a RTT and this flag 769 * should be set. Every time the RTT 770 * calculation completes (i.e. the DATA chunk 771 * is SACK'd) clear this flag. 772 */ 773 rto_pending:1, 774 775 /* 776 * hb_sent : a flag that signals that we have a pending 777 * heartbeat. 778 */ 779 hb_sent:1, 780 781 /* Is the Path MTU update pending on this tranport */ 782 pmtu_pending:1, 783 784 /* Is this structure kfree()able? */ 785 malloced:1; 786 787 /* Has this transport moved the ctsn since we last sacked */ 788 __u32 sack_generation; 789 790 struct flowi fl; 791 792 /* This is the peer's IP address and port. */ 793 union sctp_addr ipaddr; 794 795 /* These are the functions we call to handle LLP stuff. */ 796 struct sctp_af *af_specific; 797 798 /* Which association do we belong to? */ 799 struct sctp_association *asoc; 800 801 /* RFC2960 802 * 803 * 12.3 Per Transport Address Data 804 * 805 * For each destination transport address in the peer's 806 * address list derived from the INIT or INIT ACK chunk, a 807 * number of data elements needs to be maintained including: 808 */ 809 /* RTO : The current retransmission timeout value. */ 810 unsigned long rto; 811 812 __u32 rtt; /* This is the most recent RTT. */ 813 814 /* RTTVAR : The current RTT variation. */ 815 __u32 rttvar; 816 817 /* SRTT : The current smoothed round trip time. */ 818 __u32 srtt; 819 820 /* 821 * These are the congestion stats. 822 */ 823 /* cwnd : The current congestion window. */ 824 __u32 cwnd; /* This is the actual cwnd. */ 825 826 /* ssthresh : The current slow start threshold value. */ 827 __u32 ssthresh; 828 829 /* partial : The tracking method for increase of cwnd when in 830 * bytes acked : congestion avoidance mode (see Section 6.2.2) 831 */ 832 __u32 partial_bytes_acked; 833 834 /* Data that has been sent, but not acknowledged. */ 835 __u32 flight_size; 836 837 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */ 838 839 /* Destination */ 840 struct dst_entry *dst; 841 /* Source address. */ 842 union sctp_addr saddr; 843 844 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 845 * the destination address every heartbeat interval. 846 */ 847 unsigned long hbinterval; 848 849 /* SACK delay timeout */ 850 unsigned long sackdelay; 851 __u32 sackfreq; 852 853 /* When was the last time (in jiffies) that we heard from this 854 * transport? We use this to pick new active and retran paths. 855 */ 856 unsigned long last_time_heard; 857 858 /* Last time(in jiffies) when cwnd is reduced due to the congestion 859 * indication based on ECNE chunk. 860 */ 861 unsigned long last_time_ecne_reduced; 862 863 /* This is the max_retrans value for the transport and will 864 * be initialized from the assocs value. This can be changed 865 * using the SCTP_SET_PEER_ADDR_PARAMS socket option. 866 */ 867 __u16 pathmaxrxt; 868 869 /* This is the partially failed retrans value for the transport 870 * and will be initialized from the assocs value. This can be changed 871 * using the SCTP_PEER_ADDR_THLDS socket option 872 */ 873 int pf_retrans; 874 /* PMTU : The current known path MTU. */ 875 __u32 pathmtu; 876 877 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ 878 __u32 param_flags; 879 880 /* The number of times INIT has been sent on this transport. */ 881 int init_sent_count; 882 883 /* state : The current state of this destination, 884 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN. 885 */ 886 int state; 887 888 /* These are the error stats for this destination. */ 889 890 /* Error count : The current error count for this destination. */ 891 unsigned short error_count; 892 893 /* Per : A timer used by each destination. 894 * Destination : 895 * Timer : 896 * 897 * [Everywhere else in the text this is called T3-rtx. -ed] 898 */ 899 struct timer_list T3_rtx_timer; 900 901 /* Heartbeat timer is per destination. */ 902 struct timer_list hb_timer; 903 904 /* Timer to handle ICMP proto unreachable envets */ 905 struct timer_list proto_unreach_timer; 906 907 /* Since we're using per-destination retransmission timers 908 * (see above), we're also using per-destination "transmitted" 909 * queues. This probably ought to be a private struct 910 * accessible only within the outqueue, but it's not, yet. 911 */ 912 struct list_head transmitted; 913 914 /* We build bundle-able packets for this transport here. */ 915 struct sctp_packet packet; 916 917 /* This is the list of transports that have chunks to send. */ 918 struct list_head send_ready; 919 920 /* State information saved for SFR_CACC algorithm. The key 921 * idea in SFR_CACC is to maintain state at the sender on a 922 * per-destination basis when a changeover happens. 923 * char changeover_active; 924 * char cycling_changeover; 925 * __u32 next_tsn_at_change; 926 * char cacc_saw_newack; 927 */ 928 struct { 929 /* An unsigned integer, which stores the next TSN to be 930 * used by the sender, at the moment of changeover. 931 */ 932 __u32 next_tsn_at_change; 933 934 /* A flag which indicates the occurrence of a changeover */ 935 char changeover_active; 936 937 /* A flag which indicates whether the change of primary is 938 * the first switch to this destination address during an 939 * active switch. 940 */ 941 char cycling_changeover; 942 943 /* A temporary flag, which is used during the processing of 944 * a SACK to estimate the causative TSN(s)'s group. 945 */ 946 char cacc_saw_newack; 947 } cacc; 948 949 /* 64-bit random number sent with heartbeat. */ 950 __u64 hb_nonce; 951}; 952 953struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *, 954 gfp_t); 955void sctp_transport_set_owner(struct sctp_transport *, 956 struct sctp_association *); 957void sctp_transport_route(struct sctp_transport *, union sctp_addr *, 958 struct sctp_sock *); 959void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk); 960void sctp_transport_free(struct sctp_transport *); 961void sctp_transport_reset_timers(struct sctp_transport *); 962void sctp_transport_hold(struct sctp_transport *); 963void sctp_transport_put(struct sctp_transport *); 964void sctp_transport_update_rto(struct sctp_transport *, __u32); 965void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32); 966void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t); 967void sctp_transport_burst_limited(struct sctp_transport *); 968void sctp_transport_burst_reset(struct sctp_transport *); 969unsigned long sctp_transport_timeout(struct sctp_transport *); 970void sctp_transport_reset(struct sctp_transport *); 971void sctp_transport_update_pmtu(struct sock *, struct sctp_transport *, u32); 972void sctp_transport_immediate_rtx(struct sctp_transport *); 973 974 975/* This is the structure we use to queue packets as they come into 976 * SCTP. We write packets to it and read chunks from it. 977 */ 978struct sctp_inq { 979 /* This is actually a queue of sctp_chunk each 980 * containing a partially decoded packet. 981 */ 982 struct list_head in_chunk_list; 983 /* This is the packet which is currently off the in queue and is 984 * being worked on through the inbound chunk processing. 985 */ 986 struct sctp_chunk *in_progress; 987 988 /* This is the delayed task to finish delivering inbound 989 * messages. 990 */ 991 struct work_struct immediate; 992 993 int malloced; /* Is this structure kfree()able? */ 994}; 995 996void sctp_inq_init(struct sctp_inq *); 997void sctp_inq_free(struct sctp_inq *); 998void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet); 999struct sctp_chunk *sctp_inq_pop(struct sctp_inq *); 1000struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1001void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t); 1002 1003/* This is the structure we use to hold outbound chunks. You push 1004 * chunks in and they automatically pop out the other end as bundled 1005 * packets (it calls (*output_handler)()). 1006 * 1007 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1, 1008 * and 8.2 of the v13 draft. 1009 * 1010 * It handles retransmissions. The connection to the timeout portion 1011 * of the state machine is through sctp_..._timeout() and timeout_handler. 1012 * 1013 * If you feed it SACKs, it will eat them. 1014 * 1015 * If you give it big chunks, it will fragment them. 1016 * 1017 * It assigns TSN's to data chunks. This happens at the last possible 1018 * instant before transmission. 1019 * 1020 * When free()'d, it empties itself out via output_handler(). 1021 */ 1022struct sctp_outq { 1023 struct sctp_association *asoc; 1024 1025 /* Data pending that has never been transmitted. */ 1026 struct list_head out_chunk_list; 1027 1028 unsigned int out_qlen; /* Total length of queued data chunks. */ 1029 1030 /* Error of send failed, may used in SCTP_SEND_FAILED event. */ 1031 unsigned int error; 1032 1033 /* These are control chunks we want to send. */ 1034 struct list_head control_chunk_list; 1035 1036 /* These are chunks that have been sacked but are above the 1037 * CTSN, or cumulative tsn ack point. 1038 */ 1039 struct list_head sacked; 1040 1041 /* Put chunks on this list to schedule them for 1042 * retransmission. 1043 */ 1044 struct list_head retransmit; 1045 1046 /* Put chunks on this list to save them for FWD TSN processing as 1047 * they were abandoned. 1048 */ 1049 struct list_head abandoned; 1050 1051 /* How many unackd bytes do we have in-flight? */ 1052 __u32 outstanding_bytes; 1053 1054 /* Are we doing fast-rtx on this queue */ 1055 char fast_rtx; 1056 1057 /* Corked? */ 1058 char cork; 1059 1060 /* Is this structure empty? */ 1061 char empty; 1062 1063 /* Are we kfree()able? */ 1064 char malloced; 1065}; 1066 1067void sctp_outq_init(struct sctp_association *, struct sctp_outq *); 1068void sctp_outq_teardown(struct sctp_outq *); 1069void sctp_outq_free(struct sctp_outq*); 1070int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk); 1071int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *); 1072int sctp_outq_is_empty(const struct sctp_outq *); 1073void sctp_outq_restart(struct sctp_outq *); 1074 1075void sctp_retransmit(struct sctp_outq *, struct sctp_transport *, 1076 sctp_retransmit_reason_t); 1077void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); 1078int sctp_outq_uncork(struct sctp_outq *); 1079/* Uncork and flush an outqueue. */ 1080static inline void sctp_outq_cork(struct sctp_outq *q) 1081{ 1082 q->cork = 1; 1083} 1084 1085/* These bind address data fields common between endpoints and associations */ 1086struct sctp_bind_addr { 1087 1088 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1089 * 1090 * SCTP Port: The local SCTP port number the endpoint is 1091 * bound to. 1092 */ 1093 __u16 port; 1094 1095 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1096 * 1097 * Address List: The list of IP addresses that this instance 1098 * has bound. This information is passed to one's 1099 * peer(s) in INIT and INIT ACK chunks. 1100 */ 1101 struct list_head address_list; 1102 1103 int malloced; /* Are we kfree()able? */ 1104}; 1105 1106void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port); 1107void sctp_bind_addr_free(struct sctp_bind_addr *); 1108int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest, 1109 const struct sctp_bind_addr *src, 1110 sctp_scope_t scope, gfp_t gfp, 1111 int flags); 1112int sctp_bind_addr_dup(struct sctp_bind_addr *dest, 1113 const struct sctp_bind_addr *src, 1114 gfp_t gfp); 1115int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1116 __u8 addr_state, gfp_t gfp); 1117int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *); 1118int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, 1119 struct sctp_sock *); 1120int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *, 1121 struct sctp_sock *, struct sctp_sock *); 1122int sctp_bind_addr_state(const struct sctp_bind_addr *bp, 1123 const union sctp_addr *addr); 1124union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 1125 const union sctp_addr *addrs, 1126 int addrcnt, 1127 struct sctp_sock *opt); 1128union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 1129 int *addrs_len, 1130 gfp_t gfp); 1131int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, 1132 __u16 port, gfp_t gfp); 1133 1134sctp_scope_t sctp_scope(const union sctp_addr *); 1135int sctp_in_scope(struct net *net, const union sctp_addr *addr, const sctp_scope_t scope); 1136int sctp_is_any(struct sock *sk, const union sctp_addr *addr); 1137int sctp_addr_is_valid(const union sctp_addr *addr); 1138int sctp_is_ep_boundall(struct sock *sk); 1139 1140 1141/* What type of endpoint? */ 1142typedef enum { 1143 SCTP_EP_TYPE_SOCKET, 1144 SCTP_EP_TYPE_ASSOCIATION, 1145} sctp_endpoint_type_t; 1146 1147/* 1148 * A common base class to bridge the implmentation view of a 1149 * socket (usually listening) endpoint versus an association's 1150 * local endpoint. 1151 * This common structure is useful for several purposes: 1152 * 1) Common interface for lookup routines. 1153 * a) Subfunctions work for either endpoint or association 1154 * b) Single interface to lookup allows hiding the lookup lock rather 1155 * than acquiring it externally. 1156 * 2) Common interface for the inbound chunk handling/state machine. 1157 * 3) Common object handling routines for reference counting, etc. 1158 * 4) Disentangle association lookup from endpoint lookup, where we 1159 * do not have to find our endpoint to find our association. 1160 * 1161 */ 1162 1163struct sctp_ep_common { 1164 /* Fields to help us manage our entries in the hash tables. */ 1165 struct hlist_node node; 1166 int hashent; 1167 1168 /* Runtime type information. What kind of endpoint is this? */ 1169 sctp_endpoint_type_t type; 1170 1171 /* Some fields to help us manage this object. 1172 * refcnt - Reference count access to this object. 1173 * dead - Do not attempt to use this object. 1174 * malloced - Do we need to kfree this object? 1175 */ 1176 atomic_t refcnt; 1177 char dead; 1178 char malloced; 1179 1180 /* What socket does this endpoint belong to? */ 1181 struct sock *sk; 1182 1183 /* This is where we receive inbound chunks. */ 1184 struct sctp_inq inqueue; 1185 1186 /* This substructure includes the defining parameters of the 1187 * endpoint: 1188 * bind_addr.port is our shared port number. 1189 * bind_addr.address_list is our set of local IP addresses. 1190 */ 1191 struct sctp_bind_addr bind_addr; 1192}; 1193 1194 1195/* RFC Section 1.4 Key Terms 1196 * 1197 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a 1198 * multi-homed host, an SCTP endpoint is represented to its peers as a 1199 * combination of a set of eligible destination transport addresses to 1200 * which SCTP packets can be sent and a set of eligible source 1201 * transport addresses from which SCTP packets can be received. 1202 * All transport addresses used by an SCTP endpoint must use the 1203 * same port number, but can use multiple IP addresses. A transport 1204 * address used by an SCTP endpoint must not be used by another 1205 * SCTP endpoint. In other words, a transport address is unique 1206 * to an SCTP endpoint. 1207 * 1208 * From an implementation perspective, each socket has one of these. 1209 * A TCP-style socket will have exactly one association on one of 1210 * these. An UDP-style socket will have multiple associations hanging 1211 * off one of these. 1212 */ 1213 1214struct sctp_endpoint { 1215 /* Common substructure for endpoint and association. */ 1216 struct sctp_ep_common base; 1217 1218 /* Associations: A list of current associations and mappings 1219 * to the data consumers for each association. This 1220 * may be in the form of a hash table or other 1221 * implementation dependent structure. The data 1222 * consumers may be process identification 1223 * information such as file descriptors, named pipe 1224 * pointer, or table pointers dependent on how SCTP 1225 * is implemented. 1226 */ 1227 /* This is really a list of struct sctp_association entries. */ 1228 struct list_head asocs; 1229 1230 /* Secret Key: A secret key used by this endpoint to compute 1231 * the MAC. This SHOULD be a cryptographic quality 1232 * random number with a sufficient length. 1233 * Discussion in [RFC1750] can be helpful in 1234 * selection of the key. 1235 */ 1236 __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE]; 1237 int current_key; 1238 int last_key; 1239 int key_changed_at; 1240 1241 /* digest: This is a digest of the sctp cookie. This field is 1242 * only used on the receive path when we try to validate 1243 * that the cookie has not been tampered with. We put 1244 * this here so we pre-allocate this once and can re-use 1245 * on every receive. 1246 */ 1247 __u8 *digest; 1248 1249 /* sendbuf acct. policy. */ 1250 __u32 sndbuf_policy; 1251 1252 /* rcvbuf acct. policy. */ 1253 __u32 rcvbuf_policy; 1254 1255 /* SCTP AUTH: array of the HMACs that will be allocated 1256 * we need this per association so that we don't serialize 1257 */ 1258 struct crypto_hash **auth_hmacs; 1259 1260 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */ 1261 struct sctp_hmac_algo_param *auth_hmacs_list; 1262 1263 /* SCTP-AUTH: chunks to authenticate encoded into parameter */ 1264 struct sctp_chunks_param *auth_chunk_list; 1265 1266 /* SCTP-AUTH: endpoint shared keys */ 1267 struct list_head endpoint_shared_keys; 1268 __u16 active_key_id; 1269}; 1270 1271/* Recover the outter endpoint structure. */ 1272static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) 1273{ 1274 struct sctp_endpoint *ep; 1275 1276 ep = container_of(base, struct sctp_endpoint, base); 1277 return ep; 1278} 1279 1280/* These are function signatures for manipulating endpoints. */ 1281struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t); 1282void sctp_endpoint_free(struct sctp_endpoint *); 1283void sctp_endpoint_put(struct sctp_endpoint *); 1284void sctp_endpoint_hold(struct sctp_endpoint *); 1285void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); 1286struct sctp_association *sctp_endpoint_lookup_assoc( 1287 const struct sctp_endpoint *ep, 1288 const union sctp_addr *paddr, 1289 struct sctp_transport **); 1290int sctp_endpoint_is_peeled_off(struct sctp_endpoint *, 1291 const union sctp_addr *); 1292struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *, 1293 struct net *, const union sctp_addr *); 1294int sctp_has_association(struct net *net, const union sctp_addr *laddr, 1295 const union sctp_addr *paddr); 1296 1297int sctp_verify_init(struct net *net, const struct sctp_association *asoc, 1298 sctp_cid_t, sctp_init_chunk_t *peer_init, 1299 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk); 1300int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk, 1301 const union sctp_addr *peer, 1302 sctp_init_chunk_t *init, gfp_t gfp); 1303__u32 sctp_generate_tag(const struct sctp_endpoint *); 1304__u32 sctp_generate_tsn(const struct sctp_endpoint *); 1305 1306struct sctp_inithdr_host { 1307 __u32 init_tag; 1308 __u32 a_rwnd; 1309 __u16 num_outbound_streams; 1310 __u16 num_inbound_streams; 1311 __u32 initial_tsn; 1312}; 1313 1314/* RFC2960 1315 * 1316 * 12. Recommended Transmission Control Block (TCB) Parameters 1317 * 1318 * This section details a recommended set of parameters that should 1319 * be contained within the TCB for an implementation. This section is 1320 * for illustrative purposes and should not be deemed as requirements 1321 * on an implementation or as an exhaustive list of all parameters 1322 * inside an SCTP TCB. Each implementation may need its own additional 1323 * parameters for optimization. 1324 */ 1325 1326 1327/* Here we have information about each individual association. */ 1328struct sctp_association { 1329 1330 /* A base structure common to endpoint and association. 1331 * In this context, it represents the associations's view 1332 * of the local endpoint of the association. 1333 */ 1334 struct sctp_ep_common base; 1335 1336 /* Associations on the same socket. */ 1337 struct list_head asocs; 1338 1339 /* association id. */ 1340 sctp_assoc_t assoc_id; 1341 1342 /* This is our parent endpoint. */ 1343 struct sctp_endpoint *ep; 1344 1345 /* These are those association elements needed in the cookie. */ 1346 struct sctp_cookie c; 1347 1348 /* This is all information about our peer. */ 1349 struct { 1350 /* rwnd 1351 * 1352 * Peer Rwnd : Current calculated value of the peer's rwnd. 1353 */ 1354 __u32 rwnd; 1355 1356 /* transport_addr_list 1357 * 1358 * Peer : A list of SCTP transport addresses that the 1359 * Transport : peer is bound to. This information is derived 1360 * Address : from the INIT or INIT ACK and is used to 1361 * List : associate an inbound packet with a given 1362 * : association. Normally this information is 1363 * : hashed or keyed for quick lookup and access 1364 * : of the TCB. 1365 * : The list is also initialized with the list 1366 * : of addresses passed with the sctp_connectx() 1367 * : call. 1368 * 1369 * It is a list of SCTP_transport's. 1370 */ 1371 struct list_head transport_addr_list; 1372 1373 /* transport_count 1374 * 1375 * Peer : A count of the number of peer addresses 1376 * Transport : in the Peer Transport Address List. 1377 * Address : 1378 * Count : 1379 */ 1380 __u16 transport_count; 1381 1382 /* port 1383 * The transport layer port number. 1384 */ 1385 __u16 port; 1386 1387 /* primary_path 1388 * 1389 * Primary : This is the current primary destination 1390 * Path : transport address of the peer endpoint. It 1391 * : may also specify a source transport address 1392 * : on this endpoint. 1393 * 1394 * All of these paths live on transport_addr_list. 1395 * 1396 * At the bakeoffs, we discovered that the intent of 1397 * primaryPath is that it only changes when the ULP 1398 * asks to have it changed. We add the activePath to 1399 * designate the connection we are currently using to 1400 * transmit new data and most control chunks. 1401 */ 1402 struct sctp_transport *primary_path; 1403 1404 /* Cache the primary path address here, when we 1405 * need a an address for msg_name. 1406 */ 1407 union sctp_addr primary_addr; 1408 1409 /* active_path 1410 * The path that we are currently using to 1411 * transmit new data and most control chunks. 1412 */ 1413 struct sctp_transport *active_path; 1414 1415 /* retran_path 1416 * 1417 * RFC2960 6.4 Multi-homed SCTP Endpoints 1418 * ... 1419 * Furthermore, when its peer is multi-homed, an 1420 * endpoint SHOULD try to retransmit a chunk to an 1421 * active destination transport address that is 1422 * different from the last destination address to 1423 * which the DATA chunk was sent. 1424 */ 1425 struct sctp_transport *retran_path; 1426 1427 /* Pointer to last transport I have sent on. */ 1428 struct sctp_transport *last_sent_to; 1429 1430 /* This is the last transport I have received DATA on. */ 1431 struct sctp_transport *last_data_from; 1432 1433 /* 1434 * Mapping An array of bits or bytes indicating which out of 1435 * Array order TSN's have been received (relative to the 1436 * Last Rcvd TSN). If no gaps exist, i.e. no out of 1437 * order packets have been received, this array 1438 * will be set to all zero. This structure may be 1439 * in the form of a circular buffer or bit array. 1440 * 1441 * Last Rcvd : This is the last TSN received in 1442 * TSN : sequence. This value is set initially by 1443 * : taking the peer's Initial TSN, received in 1444 * : the INIT or INIT ACK chunk, and subtracting 1445 * : one from it. 1446 * 1447 * Throughout most of the specification this is called the 1448 * "Cumulative TSN ACK Point". In this case, we 1449 * ignore the advice in 12.2 in favour of the term 1450 * used in the bulk of the text. This value is hidden 1451 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). 1452 */ 1453 struct sctp_tsnmap tsn_map; 1454 1455 /* Ack State : This flag indicates if the next received 1456 * : packet is to be responded to with a 1457 * : SACK. This is initializedto 0. When a packet 1458 * : is received it is incremented. If this value 1459 * : reaches 2 or more, a SACK is sent and the 1460 * : value is reset to 0. Note: This is used only 1461 * : when no DATA chunks are received out of 1462 * : order. When DATA chunks are out of order, 1463 * : SACK's are not delayed (see Section 6). 1464 */ 1465 __u8 sack_needed; /* Do we need to sack the peer? */ 1466 __u32 sack_cnt; 1467 __u32 sack_generation; 1468 1469 /* These are capabilities which our peer advertised. */ 1470 __u8 ecn_capable:1, /* Can peer do ECN? */ 1471 ipv4_address:1, /* Peer understands IPv4 addresses? */ 1472 ipv6_address:1, /* Peer understands IPv6 addresses? */ 1473 hostname_address:1, /* Peer understands DNS addresses? */ 1474 asconf_capable:1, /* Does peer support ADDIP? */ 1475 prsctp_capable:1, /* Can peer do PR-SCTP? */ 1476 auth_capable:1; /* Is peer doing SCTP-AUTH? */ 1477 1478 __u32 adaptation_ind; /* Adaptation Code point. */ 1479 1480 /* This mask is used to disable sending the ASCONF chunk 1481 * with specified parameter to peer. 1482 */ 1483 __be16 addip_disabled_mask; 1484 1485 struct sctp_inithdr_host i; 1486 int cookie_len; 1487 void *cookie; 1488 1489 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1490 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the 1491 * Initial TSN Value minus 1 1492 */ 1493 __u32 addip_serial; 1494 1495 /* SCTP-AUTH: We need to know pears random number, hmac list 1496 * and authenticated chunk list. All that is part of the 1497 * cookie and these are just pointers to those locations 1498 */ 1499 sctp_random_param_t *peer_random; 1500 sctp_chunks_param_t *peer_chunks; 1501 sctp_hmac_algo_param_t *peer_hmacs; 1502 } peer; 1503 1504 /* State : A state variable indicating what state the 1505 * : association is in, i.e. COOKIE-WAIT, 1506 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, 1507 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. 1508 * 1509 * Note: No "CLOSED" state is illustrated since if a 1510 * association is "CLOSED" its TCB SHOULD be removed. 1511 * 1512 * In this implementation we DO have a CLOSED 1513 * state which is used during initiation and shutdown. 1514 * 1515 * State takes values from SCTP_STATE_*. 1516 */ 1517 sctp_state_t state; 1518 1519 /* The cookie life I award for any cookie. */ 1520 struct timeval cookie_life; 1521 1522 /* Overall : The overall association error count. 1523 * Error Count : [Clear this any time I get something.] 1524 */ 1525 int overall_error_count; 1526 1527 /* These are the association's initial, max, and min RTO values. 1528 * These values will be initialized by system defaults, but can 1529 * be modified via the SCTP_RTOINFO socket option. 1530 */ 1531 unsigned long rto_initial; 1532 unsigned long rto_max; 1533 unsigned long rto_min; 1534 1535 /* Maximum number of new data packets that can be sent in a burst. */ 1536 int max_burst; 1537 1538 /* This is the max_retrans value for the association. This value will 1539 * be initialized initialized from system defaults, but can be 1540 * modified by the SCTP_ASSOCINFO socket option. 1541 */ 1542 int max_retrans; 1543 1544 /* This is the partially failed retrans value for the transport 1545 * and will be initialized from the assocs value. This can be 1546 * changed using the SCTP_PEER_ADDR_THLDS socket option 1547 */ 1548 int pf_retrans; 1549 1550 /* Maximum number of times the endpoint will retransmit INIT */ 1551 __u16 max_init_attempts; 1552 1553 /* How many times have we resent an INIT? */ 1554 __u16 init_retries; 1555 1556 /* The largest timeout or RTO value to use in attempting an INIT */ 1557 unsigned long max_init_timeo; 1558 1559 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 1560 * the destination address every heartbeat interval. This value 1561 * will be inherited by all new transports. 1562 */ 1563 unsigned long hbinterval; 1564 1565 /* This is the max_retrans value for new transports in the 1566 * association. 1567 */ 1568 __u16 pathmaxrxt; 1569 1570 /* Flag that path mtu update is pending */ 1571 __u8 pmtu_pending; 1572 1573 /* Association : The smallest PMTU discovered for all of the 1574 * PMTU : peer's transport addresses. 1575 */ 1576 __u32 pathmtu; 1577 1578 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ 1579 __u32 param_flags; 1580 1581 /* SACK delay timeout */ 1582 unsigned long sackdelay; 1583 __u32 sackfreq; 1584 1585 1586 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1587 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; 1588 1589 /* Transport to which SHUTDOWN chunk was last sent. */ 1590 struct sctp_transport *shutdown_last_sent_to; 1591 1592 /* How many times have we resent a SHUTDOWN */ 1593 int shutdown_retries; 1594 1595 /* Transport to which INIT chunk was last sent. */ 1596 struct sctp_transport *init_last_sent_to; 1597 1598 /* Next TSN : The next TSN number to be assigned to a new 1599 * : DATA chunk. This is sent in the INIT or INIT 1600 * : ACK chunk to the peer and incremented each 1601 * : time a DATA chunk is assigned a TSN 1602 * : (normally just prior to transmit or during 1603 * : fragmentation). 1604 */ 1605 __u32 next_tsn; 1606 1607 /* 1608 * Last Rcvd : This is the last TSN received in sequence. This value 1609 * TSN : is set initially by taking the peer's Initial TSN, 1610 * : received in the INIT or INIT ACK chunk, and 1611 * : subtracting one from it. 1612 * 1613 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. 1614 */ 1615 1616 __u32 ctsn_ack_point; 1617 1618 /* PR-SCTP Advanced.Peer.Ack.Point */ 1619 __u32 adv_peer_ack_point; 1620 1621 /* Highest TSN that is acknowledged by incoming SACKs. */ 1622 __u32 highest_sacked; 1623 1624 /* TSN marking the fast recovery exit point */ 1625 __u32 fast_recovery_exit; 1626 1627 /* Flag to track the current fast recovery state */ 1628 __u8 fast_recovery; 1629 1630 /* The number of unacknowledged data chunks. Reported through 1631 * the SCTP_STATUS sockopt. 1632 */ 1633 __u16 unack_data; 1634 1635 /* The total number of data chunks that we've had to retransmit 1636 * as the result of a T3 timer expiration 1637 */ 1638 __u32 rtx_data_chunks; 1639 1640 /* This is the association's receive buffer space. This value is used 1641 * to set a_rwnd field in an INIT or a SACK chunk. 1642 */ 1643 __u32 rwnd; 1644 1645 /* This is the last advertised value of rwnd over a SACK chunk. */ 1646 __u32 a_rwnd; 1647 1648 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed 1649 * to slop over a maximum of the association's frag_point. 1650 */ 1651 __u32 rwnd_over; 1652 1653 /* Keeps treack of rwnd pressure. This happens when we have 1654 * a window, but not recevie buffer (i.e small packets). This one 1655 * is releases slowly (1 PMTU at a time ). 1656 */ 1657 __u32 rwnd_press; 1658 1659 /* This is the sndbuf size in use for the association. 1660 * This corresponds to the sndbuf size for the association, 1661 * as specified in the sk->sndbuf. 1662 */ 1663 int sndbuf_used; 1664 1665 /* This is the amount of memory that this association has allocated 1666 * in the receive path at any given time. 1667 */ 1668 atomic_t rmem_alloc; 1669 1670 /* This is the wait queue head for send requests waiting on 1671 * the association sndbuf space. 1672 */ 1673 wait_queue_head_t wait; 1674 1675 /* The message size at which SCTP fragmentation will occur. */ 1676 __u32 frag_point; 1677 __u32 user_frag; 1678 1679 /* Counter used to count INIT errors. */ 1680 int init_err_counter; 1681 1682 /* Count the number of INIT cycles (for doubling timeout). */ 1683 int init_cycle; 1684 1685 /* Default send parameters. */ 1686 __u16 default_stream; 1687 __u16 default_flags; 1688 __u32 default_ppid; 1689 __u32 default_context; 1690 __u32 default_timetolive; 1691 1692 /* Default receive parameters */ 1693 __u32 default_rcv_context; 1694 1695 /* This tracks outbound ssn for a given stream. */ 1696 struct sctp_ssnmap *ssnmap; 1697 1698 /* All outbound chunks go through this structure. */ 1699 struct sctp_outq outqueue; 1700 1701 /* A smart pipe that will handle reordering and fragmentation, 1702 * as well as handle passing events up to the ULP. 1703 */ 1704 struct sctp_ulpq ulpq; 1705 1706 /* Last TSN that caused an ECNE Chunk to be sent. */ 1707 __u32 last_ecne_tsn; 1708 1709 /* Last TSN that caused a CWR Chunk to be sent. */ 1710 __u32 last_cwr_tsn; 1711 1712 /* How many duplicated TSNs have we seen? */ 1713 int numduptsns; 1714 1715 /* Number of seconds of idle time before an association is closed. 1716 * In the association context, this is really used as a boolean 1717 * since the real timeout is stored in the timeouts array 1718 */ 1719 __u32 autoclose; 1720 1721 /* These are to support 1722 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses 1723 * and Enforcement of Flow and Message Limits" 1724 * <draft-ietf-tsvwg-addip-sctp-02.txt> 1725 * or "ADDIP" for short. 1726 */ 1727 1728 1729 1730 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1731 * 1732 * R1) One and only one ASCONF Chunk MAY be in transit and 1733 * unacknowledged at any one time. If a sender, after sending 1734 * an ASCONF chunk, decides it needs to transfer another 1735 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1736 * returns from the previous ASCONF Chunk before sending a 1737 * subsequent ASCONF. Note this restriction binds each side, 1738 * so at any time two ASCONF may be in-transit on any given 1739 * association (one sent from each endpoint). 1740 * 1741 * [This is our one-and-only-one ASCONF in flight. If we do 1742 * not have an ASCONF in flight, this is NULL.] 1743 */ 1744 struct sctp_chunk *addip_last_asconf; 1745 1746 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk. 1747 * 1748 * This is needed to implement itmes E1 - E4 of the updated 1749 * spec. Here is the justification: 1750 * 1751 * Since the peer may bundle multiple ASCONF chunks toward us, 1752 * we now need the ability to cache multiple ACKs. The section 1753 * describes in detail how they are cached and cleaned up. 1754 */ 1755 struct list_head asconf_ack_list; 1756 1757 /* These ASCONF chunks are waiting to be sent. 1758 * 1759 * These chunaks can't be pushed to outqueue until receiving 1760 * ASCONF_ACK for the previous ASCONF indicated by 1761 * addip_last_asconf, so as to guarantee that only one ASCONF 1762 * is in flight at any time. 1763 * 1764 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1765 * 1766 * In defining the ASCONF Chunk transfer procedures, it is 1767 * essential that these transfers MUST NOT cause congestion 1768 * within the network. To achieve this, we place these 1769 * restrictions on the transfer of ASCONF Chunks: 1770 * 1771 * R1) One and only one ASCONF Chunk MAY be in transit and 1772 * unacknowledged at any one time. If a sender, after sending 1773 * an ASCONF chunk, decides it needs to transfer another 1774 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1775 * returns from the previous ASCONF Chunk before sending a 1776 * subsequent ASCONF. Note this restriction binds each side, 1777 * so at any time two ASCONF may be in-transit on any given 1778 * association (one sent from each endpoint). 1779 * 1780 * 1781 * [I really think this is EXACTLY the sort of intelligence 1782 * which already resides in sctp_outq. Please move this 1783 * queue and its supporting logic down there. --piggy] 1784 */ 1785 struct list_head addip_chunk_list; 1786 1787 /* ADDIP Section 4.1 ASCONF Chunk Procedures 1788 * 1789 * A2) A serial number should be assigned to the Chunk. The 1790 * serial number SHOULD be a monotonically increasing 1791 * number. The serial number SHOULD be initialized at 1792 * the start of the association to the same value as the 1793 * Initial TSN and every time a new ASCONF chunk is created 1794 * it is incremented by one after assigning the serial number 1795 * to the newly created chunk. 1796 * 1797 * ADDIP 1798 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) 1799 * 1800 * Serial Number : 32 bits (unsigned integer) 1801 * 1802 * This value represents a Serial Number for the ASCONF 1803 * Chunk. The valid range of Serial Number is from 0 to 1804 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 1805 * after reaching 4294967295. 1806 */ 1807 __u32 addip_serial; 1808 union sctp_addr *asconf_addr_del_pending; 1809 int src_out_of_asoc_ok; 1810 struct sctp_transport *new_transport; 1811 1812 /* SCTP AUTH: list of the endpoint shared keys. These 1813 * keys are provided out of band by the user applicaton 1814 * and can't change during the lifetime of the association 1815 */ 1816 struct list_head endpoint_shared_keys; 1817 1818 /* SCTP AUTH: 1819 * The current generated assocaition shared key (secret) 1820 */ 1821 struct sctp_auth_bytes *asoc_shared_key; 1822 1823 /* SCTP AUTH: hmac id of the first peer requested algorithm 1824 * that we support. 1825 */ 1826 __u16 default_hmac_id; 1827 1828 __u16 active_key_id; 1829 1830 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */ 1831 temp:1; /* Is it a temporary association? */ 1832}; 1833 1834 1835/* An eyecatcher for determining if we are really looking at an 1836 * association data structure. 1837 */ 1838enum { 1839 SCTP_ASSOC_EYECATCHER = 0xa550c123, 1840}; 1841 1842/* Recover the outter association structure. */ 1843static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) 1844{ 1845 struct sctp_association *asoc; 1846 1847 asoc = container_of(base, struct sctp_association, base); 1848 return asoc; 1849} 1850 1851/* These are function signatures for manipulating associations. */ 1852 1853 1854struct sctp_association * 1855sctp_association_new(const struct sctp_endpoint *, const struct sock *, 1856 sctp_scope_t scope, gfp_t gfp); 1857void sctp_association_free(struct sctp_association *); 1858void sctp_association_put(struct sctp_association *); 1859void sctp_association_hold(struct sctp_association *); 1860 1861struct sctp_transport *sctp_assoc_choose_alter_transport( 1862 struct sctp_association *, struct sctp_transport *); 1863void sctp_assoc_update_retran_path(struct sctp_association *); 1864struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, 1865 const union sctp_addr *); 1866int sctp_assoc_lookup_laddr(struct sctp_association *asoc, 1867 const union sctp_addr *laddr); 1868struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, 1869 const union sctp_addr *address, 1870 const gfp_t gfp, 1871 const int peer_state); 1872void sctp_assoc_del_peer(struct sctp_association *asoc, 1873 const union sctp_addr *addr); 1874void sctp_assoc_rm_peer(struct sctp_association *asoc, 1875 struct sctp_transport *peer); 1876void sctp_assoc_control_transport(struct sctp_association *, 1877 struct sctp_transport *, 1878 sctp_transport_cmd_t, sctp_sn_error_t); 1879struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); 1880struct sctp_transport *sctp_assoc_is_match(struct sctp_association *, 1881 struct net *, 1882 const union sctp_addr *, 1883 const union sctp_addr *); 1884void sctp_assoc_migrate(struct sctp_association *, struct sock *); 1885void sctp_assoc_update(struct sctp_association *old, 1886 struct sctp_association *new); 1887 1888__u32 sctp_association_get_next_tsn(struct sctp_association *); 1889 1890void sctp_assoc_sync_pmtu(struct sock *, struct sctp_association *); 1891void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int); 1892void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int); 1893void sctp_assoc_set_primary(struct sctp_association *, 1894 struct sctp_transport *); 1895void sctp_assoc_del_nonprimary_peers(struct sctp_association *, 1896 struct sctp_transport *); 1897int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *, 1898 sctp_scope_t, gfp_t); 1899int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, 1900 struct sctp_cookie*, 1901 gfp_t gfp); 1902int sctp_assoc_set_id(struct sctp_association *, gfp_t); 1903void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc); 1904struct sctp_chunk *sctp_assoc_lookup_asconf_ack( 1905 const struct sctp_association *asoc, 1906 __be32 serial); 1907void sctp_asconf_queue_teardown(struct sctp_association *asoc); 1908 1909int sctp_cmp_addr_exact(const union sctp_addr *ss1, 1910 const union sctp_addr *ss2); 1911struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); 1912 1913/* A convenience structure to parse out SCTP specific CMSGs. */ 1914typedef struct sctp_cmsgs { 1915 struct sctp_initmsg *init; 1916 struct sctp_sndrcvinfo *info; 1917} sctp_cmsgs_t; 1918 1919/* Structure for tracking memory objects */ 1920typedef struct { 1921 char *label; 1922 atomic_t *counter; 1923} sctp_dbg_objcnt_entry_t; 1924 1925#endif /* __sctp_structs_h__ */ 1926