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, see 23 * <http://www.gnu.org/licenses/>. 24 * 25 * Please send any bug reports or fixes you make to the 26 * email addresses: 27 * lksctp developers <linux-sctp@vger.kernel.org> 28 * 29 * Written or modified by: 30 * Randall Stewart <randall@sctp.chicago.il.us> 31 * Ken Morneau <kmorneau@cisco.com> 32 * Qiaobing Xie <qxie1@email.mot.com> 33 * La Monte H.P. Yarroll <piggy@acm.org> 34 * Karl Knutson <karl@athena.chicago.il.us> 35 * Jon Grimm <jgrimm@us.ibm.com> 36 * Xingang Guo <xingang.guo@intel.com> 37 * Hui Huang <hui.huang@nokia.com> 38 * Sridhar Samudrala <sri@us.ibm.com> 39 * Daisy Chang <daisyc@us.ibm.com> 40 * Dajiang Zhang <dajiang.zhang@nokia.com> 41 * Ardelle Fan <ardelle.fan@intel.com> 42 * Ryan Layer <rmlayer@us.ibm.com> 43 * Anup Pemmaiah <pemmaiah@cc.usu.edu> 44 * Kevin Gao <kevin.gao@intel.com> 45 */ 46 47#ifndef __sctp_structs_h__ 48#define __sctp_structs_h__ 49 50#include <linux/ktime.h> 51#include <linux/rhashtable.h> 52#include <linux/socket.h> /* linux/in.h needs this!! */ 53#include <linux/in.h> /* We get struct sockaddr_in. */ 54#include <linux/in6.h> /* We get struct in6_addr */ 55#include <linux/ipv6.h> 56#include <asm/param.h> /* We get MAXHOSTNAMELEN. */ 57#include <linux/atomic.h> /* This gets us atomic counters. */ 58#include <linux/skbuff.h> /* We need sk_buff_head. */ 59#include <linux/workqueue.h> /* We need tq_struct. */ 60#include <linux/sctp.h> /* We need sctp* header structs. */ 61#include <net/sctp/auth.h> /* We need auth specific structs */ 62 63/* A convenience structure for handling sockaddr structures. 64 * We should wean ourselves off this. 65 */ 66union sctp_addr { 67 struct sockaddr_in v4; 68 struct sockaddr_in6 v6; 69 struct sockaddr sa; 70}; 71 72/* Forward declarations for data structures. */ 73struct sctp_globals; 74struct sctp_endpoint; 75struct sctp_association; 76struct sctp_transport; 77struct sctp_packet; 78struct sctp_chunk; 79struct sctp_inq; 80struct sctp_outq; 81struct sctp_bind_addr; 82struct sctp_ulpq; 83struct sctp_ep_common; 84struct sctp_ssnmap; 85struct crypto_shash; 86 87 88#include <net/sctp/tsnmap.h> 89#include <net/sctp/ulpevent.h> 90#include <net/sctp/ulpqueue.h> 91 92/* Structures useful for managing bind/connect. */ 93 94struct sctp_bind_bucket { 95 unsigned short port; 96 unsigned short fastreuse; 97 struct hlist_node node; 98 struct hlist_head owner; 99 struct net *net; 100}; 101 102struct sctp_bind_hashbucket { 103 spinlock_t lock; 104 struct hlist_head chain; 105}; 106 107/* Used for hashing all associations. */ 108struct sctp_hashbucket { 109 rwlock_t lock; 110 struct hlist_head chain; 111} __attribute__((__aligned__(8))); 112 113 114/* The SCTP globals structure. */ 115extern struct sctp_globals { 116 /* This is a list of groups of functions for each address 117 * family that we support. 118 */ 119 struct list_head address_families; 120 121 /* This is the hash of all endpoints. */ 122 struct sctp_hashbucket *ep_hashtable; 123 /* This is the sctp port control hash. */ 124 struct sctp_bind_hashbucket *port_hashtable; 125 /* This is the hash of all transports. */ 126 struct rhashtable transport_hashtable; 127 128 /* Sizes of above hashtables. */ 129 int ep_hashsize; 130 int port_hashsize; 131 132 /* Default initialization values to be applied to new associations. */ 133 __u16 max_instreams; 134 __u16 max_outstreams; 135 136 /* Flag to indicate whether computing and verifying checksum 137 * is disabled. */ 138 bool checksum_disable; 139} sctp_globals; 140 141#define sctp_max_instreams (sctp_globals.max_instreams) 142#define sctp_max_outstreams (sctp_globals.max_outstreams) 143#define sctp_address_families (sctp_globals.address_families) 144#define sctp_ep_hashsize (sctp_globals.ep_hashsize) 145#define sctp_ep_hashtable (sctp_globals.ep_hashtable) 146#define sctp_port_hashsize (sctp_globals.port_hashsize) 147#define sctp_port_hashtable (sctp_globals.port_hashtable) 148#define sctp_transport_hashtable (sctp_globals.transport_hashtable) 149#define sctp_checksum_disable (sctp_globals.checksum_disable) 150 151/* SCTP Socket type: UDP or TCP style. */ 152typedef enum { 153 SCTP_SOCKET_UDP = 0, 154 SCTP_SOCKET_UDP_HIGH_BANDWIDTH, 155 SCTP_SOCKET_TCP 156} sctp_socket_type_t; 157 158/* Per socket SCTP information. */ 159struct sctp_sock { 160 /* inet_sock has to be the first member of sctp_sock */ 161 struct inet_sock inet; 162 /* What kind of a socket is this? */ 163 sctp_socket_type_t type; 164 165 /* PF_ family specific functions. */ 166 struct sctp_pf *pf; 167 168 /* Access to HMAC transform. */ 169 struct crypto_shash *hmac; 170 char *sctp_hmac_alg; 171 172 /* What is our base endpointer? */ 173 struct sctp_endpoint *ep; 174 175 struct sctp_bind_bucket *bind_hash; 176 /* Various Socket Options. */ 177 __u16 default_stream; 178 __u32 default_ppid; 179 __u16 default_flags; 180 __u32 default_context; 181 __u32 default_timetolive; 182 __u32 default_rcv_context; 183 int max_burst; 184 185 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 186 * the destination address every heartbeat interval. This value 187 * will be inherited by all new associations. 188 */ 189 __u32 hbinterval; 190 191 /* This is the max_retrans value for new associations. */ 192 __u16 pathmaxrxt; 193 194 /* The initial Path MTU to use for new associations. */ 195 __u32 pathmtu; 196 197 /* The default SACK delay timeout for new associations. */ 198 __u32 sackdelay; 199 __u32 sackfreq; 200 201 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ 202 __u32 param_flags; 203 204 struct sctp_initmsg initmsg; 205 struct sctp_rtoinfo rtoinfo; 206 struct sctp_paddrparams paddrparam; 207 struct sctp_event_subscribe subscribe; 208 struct sctp_assocparams assocparams; 209 210 int user_frag; 211 212 __u32 autoclose; 213 __u32 adaptation_ind; 214 __u32 pd_point; 215 __u16 nodelay:1, 216 disable_fragments:1, 217 v4mapped:1, 218 frag_interleave:1, 219 recvrcvinfo:1, 220 recvnxtinfo:1, 221 data_ready_signalled:1; 222 223 atomic_t pd_mode; 224 /* Receive to here while partial delivery is in effect. */ 225 struct sk_buff_head pd_lobby; 226 227 /* These must be the last fields, as they will skipped on copies, 228 * like on accept and peeloff operations 229 */ 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 ktime_t 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}; 402 403struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, 404 gfp_t gfp); 405void sctp_ssnmap_free(struct sctp_ssnmap *map); 406void sctp_ssnmap_clear(struct sctp_ssnmap *map); 407 408/* What is the current SSN number for this stream? */ 409static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id) 410{ 411 return stream->ssn[id]; 412} 413 414/* Return the next SSN number for this stream. */ 415static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id) 416{ 417 return stream->ssn[id]++; 418} 419 420/* Skip over this ssn and all below. */ 421static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, 422 __u16 ssn) 423{ 424 stream->ssn[id] = ssn+1; 425} 426 427/* 428 * Pointers to address related SCTP functions. 429 * (i.e. things that depend on the address family.) 430 */ 431struct sctp_af { 432 int (*sctp_xmit) (struct sk_buff *skb, 433 struct sctp_transport *); 434 int (*setsockopt) (struct sock *sk, 435 int level, 436 int optname, 437 char __user *optval, 438 unsigned int optlen); 439 int (*getsockopt) (struct sock *sk, 440 int level, 441 int optname, 442 char __user *optval, 443 int __user *optlen); 444 int (*compat_setsockopt) (struct sock *sk, 445 int level, 446 int optname, 447 char __user *optval, 448 unsigned int optlen); 449 int (*compat_getsockopt) (struct sock *sk, 450 int level, 451 int optname, 452 char __user *optval, 453 int __user *optlen); 454 void (*get_dst) (struct sctp_transport *t, 455 union sctp_addr *saddr, 456 struct flowi *fl, 457 struct sock *sk); 458 void (*get_saddr) (struct sctp_sock *sk, 459 struct sctp_transport *t, 460 struct flowi *fl); 461 void (*copy_addrlist) (struct list_head *, 462 struct net_device *); 463 int (*cmp_addr) (const union sctp_addr *addr1, 464 const union sctp_addr *addr2); 465 void (*addr_copy) (union sctp_addr *dst, 466 union sctp_addr *src); 467 void (*from_skb) (union sctp_addr *, 468 struct sk_buff *skb, 469 int saddr); 470 void (*from_sk) (union sctp_addr *, 471 struct sock *sk); 472 void (*from_addr_param) (union sctp_addr *, 473 union sctp_addr_param *, 474 __be16 port, int iif); 475 int (*to_addr_param) (const union sctp_addr *, 476 union sctp_addr_param *); 477 int (*addr_valid) (union sctp_addr *, 478 struct sctp_sock *, 479 const struct sk_buff *); 480 sctp_scope_t (*scope) (union sctp_addr *); 481 void (*inaddr_any) (union sctp_addr *, __be16); 482 int (*is_any) (const union sctp_addr *); 483 int (*available) (union sctp_addr *, 484 struct sctp_sock *); 485 int (*skb_iif) (const struct sk_buff *sk); 486 int (*is_ce) (const struct sk_buff *sk); 487 void (*seq_dump_addr)(struct seq_file *seq, 488 union sctp_addr *addr); 489 void (*ecn_capable)(struct sock *sk); 490 __u16 net_header_len; 491 int sockaddr_len; 492 sa_family_t sa_family; 493 struct list_head list; 494}; 495 496struct sctp_af *sctp_get_af_specific(sa_family_t); 497int sctp_register_af(struct sctp_af *); 498 499/* Protocol family functions. */ 500struct sctp_pf { 501 void (*event_msgname)(struct sctp_ulpevent *, char *, int *); 502 void (*skb_msgname) (struct sk_buff *, char *, int *); 503 int (*af_supported) (sa_family_t, struct sctp_sock *); 504 int (*cmp_addr) (const union sctp_addr *, 505 const union sctp_addr *, 506 struct sctp_sock *); 507 int (*bind_verify) (struct sctp_sock *, union sctp_addr *); 508 int (*send_verify) (struct sctp_sock *, union sctp_addr *); 509 int (*supported_addrs)(const struct sctp_sock *, __be16 *); 510 struct sock *(*create_accept_sk) (struct sock *sk, 511 struct sctp_association *asoc); 512 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr); 513 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk); 514 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk); 515 struct sctp_af *af; 516}; 517 518 519/* Structure to track chunk fragments that have been acked, but peer 520 * fragments of the same message have not. 521 */ 522struct sctp_datamsg { 523 /* Chunks waiting to be submitted to lower layer. */ 524 struct list_head chunks; 525 /* Reference counting. */ 526 atomic_t refcnt; 527 /* When is this message no longer interesting to the peer? */ 528 unsigned long expires_at; 529 /* Did the messenge fail to send? */ 530 int send_error; 531 u8 send_failed:1, 532 can_abandon:1, /* can chunks from this message can be abandoned. */ 533 can_delay; /* should this message be Nagle delayed */ 534}; 535 536struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, 537 struct sctp_sndrcvinfo *, 538 struct iov_iter *); 539void sctp_datamsg_put(struct sctp_datamsg *); 540void sctp_chunk_fail(struct sctp_chunk *, int error); 541int sctp_chunk_abandoned(struct sctp_chunk *); 542 543/* RFC2960 1.4 Key Terms 544 * 545 * o Chunk: A unit of information within an SCTP packet, consisting of 546 * a chunk header and chunk-specific content. 547 * 548 * As a matter of convenience, we remember the SCTP common header for 549 * each chunk as well as a few other header pointers... 550 */ 551struct sctp_chunk { 552 struct list_head list; 553 554 atomic_t refcnt; 555 556 /* This is our link to the per-transport transmitted list. */ 557 struct list_head transmitted_list; 558 559 /* This field is used by chunks that hold fragmented data. 560 * For the first fragment this is the list that holds the rest of 561 * fragments. For the remaining fragments, this is the link to the 562 * frag_list maintained in the first fragment. 563 */ 564 struct list_head frag_list; 565 566 /* This points to the sk_buff containing the actual data. */ 567 struct sk_buff *skb; 568 569 /* These are the SCTP headers by reverse order in a packet. 570 * Note that some of these may happen more than once. In that 571 * case, we point at the "current" one, whatever that means 572 * for that level of header. 573 */ 574 575 /* We point this at the FIRST TLV parameter to chunk_hdr. */ 576 union sctp_params param_hdr; 577 union { 578 __u8 *v; 579 struct sctp_datahdr *data_hdr; 580 struct sctp_inithdr *init_hdr; 581 struct sctp_sackhdr *sack_hdr; 582 struct sctp_heartbeathdr *hb_hdr; 583 struct sctp_sender_hb_info *hbs_hdr; 584 struct sctp_shutdownhdr *shutdown_hdr; 585 struct sctp_signed_cookie *cookie_hdr; 586 struct sctp_ecnehdr *ecne_hdr; 587 struct sctp_cwrhdr *ecn_cwr_hdr; 588 struct sctp_errhdr *err_hdr; 589 struct sctp_addiphdr *addip_hdr; 590 struct sctp_fwdtsn_hdr *fwdtsn_hdr; 591 struct sctp_authhdr *auth_hdr; 592 } subh; 593 594 __u8 *chunk_end; 595 596 struct sctp_chunkhdr *chunk_hdr; 597 struct sctphdr *sctp_hdr; 598 599 /* This needs to be recoverable for SCTP_SEND_FAILED events. */ 600 struct sctp_sndrcvinfo sinfo; 601 602 /* Which association does this belong to? */ 603 struct sctp_association *asoc; 604 605 /* What endpoint received this chunk? */ 606 struct sctp_ep_common *rcvr; 607 608 /* We fill this in if we are calculating RTT. */ 609 unsigned long sent_at; 610 611 /* What is the origin IP address for this chunk? */ 612 union sctp_addr source; 613 /* Destination address for this chunk. */ 614 union sctp_addr dest; 615 616 /* For outbound message, track all fragments for SEND_FAILED. */ 617 struct sctp_datamsg *msg; 618 619 /* For an inbound chunk, this tells us where it came from. 620 * For an outbound chunk, it tells us where we'd like it to 621 * go. It is NULL if we have no preference. 622 */ 623 struct sctp_transport *transport; 624 625 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO 626 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH 627 * spec violates the principle premis that all chunks are processed 628 * in order. 629 */ 630 struct sk_buff *auth_chunk; 631 632#define SCTP_CAN_FRTX 0x0 633#define SCTP_NEED_FRTX 0x1 634#define SCTP_DONT_FRTX 0x2 635 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */ 636 resent:1, /* Has this chunk ever been resent. */ 637 has_tsn:1, /* Does this chunk have a TSN yet? */ 638 has_ssn:1, /* Does this chunk have a SSN yet? */ 639 singleton:1, /* Only chunk in the packet? */ 640 end_of_packet:1, /* Last chunk in the packet? */ 641 ecn_ce_done:1, /* Have we processed the ECN CE bit? */ 642 pdiscard:1, /* Discard the whole packet now? */ 643 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */ 644 data_accepted:1, /* At least 1 chunk accepted */ 645 auth:1, /* IN: was auth'ed | OUT: needs auth */ 646 has_asconf:1, /* IN: have seen an asconf before */ 647 tsn_missing_report:2, /* Data chunk missing counter. */ 648 fast_retransmit:2; /* Is this chunk fast retransmitted? */ 649}; 650 651void sctp_chunk_hold(struct sctp_chunk *); 652void sctp_chunk_put(struct sctp_chunk *); 653int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 654 struct iov_iter *from); 655void sctp_chunk_free(struct sctp_chunk *); 656void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); 657struct sctp_chunk *sctp_chunkify(struct sk_buff *, 658 const struct sctp_association *, 659 struct sock *, gfp_t gfp); 660void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, 661 union sctp_addr *); 662const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); 663 664enum { 665 SCTP_ADDR_NEW, /* new address added to assoc/ep */ 666 SCTP_ADDR_SRC, /* address can be used as source */ 667 SCTP_ADDR_DEL, /* address about to be deleted */ 668}; 669 670/* This is a structure for holding either an IPv6 or an IPv4 address. */ 671struct sctp_sockaddr_entry { 672 struct list_head list; 673 struct rcu_head rcu; 674 union sctp_addr a; 675 __u8 state; 676 __u8 valid; 677}; 678 679#define SCTP_ADDRESS_TICK_DELAY 500 680 681typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *); 682 683/* This structure holds lists of chunks as we are assembling for 684 * transmission. 685 */ 686struct sctp_packet { 687 /* These are the SCTP header values (host order) for the packet. */ 688 __u16 source_port; 689 __u16 destination_port; 690 __u32 vtag; 691 692 /* This contains the payload chunks. */ 693 struct list_head chunk_list; 694 695 /* This is the overhead of the sctp and ip headers. */ 696 size_t overhead; 697 /* This is the total size of all chunks INCLUDING padding. */ 698 size_t size; 699 700 /* The packet is destined for this transport address. 701 * The function we finally use to pass down to the next lower 702 * layer lives in the transport structure. 703 */ 704 struct sctp_transport *transport; 705 706 /* pointer to the auth chunk for this packet */ 707 struct sctp_chunk *auth; 708 709 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */ 710 has_sack:1, /* This packet contains a SACK chunk. */ 711 has_auth:1, /* This packet contains an AUTH chunk */ 712 has_data:1, /* This packet contains at least 1 DATA chunk */ 713 ipfragok:1; /* So let ip fragment this packet */ 714}; 715 716struct sctp_packet *sctp_packet_init(struct sctp_packet *, 717 struct sctp_transport *, 718 __u16 sport, __u16 dport); 719struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int); 720sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *, 721 struct sctp_chunk *, int, gfp_t); 722sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *, 723 struct sctp_chunk *); 724int sctp_packet_transmit(struct sctp_packet *, gfp_t); 725void sctp_packet_free(struct sctp_packet *); 726 727static inline int sctp_packet_empty(struct sctp_packet *packet) 728{ 729 return packet->size == packet->overhead; 730} 731 732/* This represents a remote transport address. 733 * For local transport addresses, we just use union sctp_addr. 734 * 735 * RFC2960 Section 1.4 Key Terms 736 * 737 * o Transport address: A Transport Address is traditionally defined 738 * by Network Layer address, Transport Layer protocol and Transport 739 * Layer port number. In the case of SCTP running over IP, a 740 * transport address is defined by the combination of an IP address 741 * and an SCTP port number (where SCTP is the Transport protocol). 742 * 743 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control 744 * 745 * o The sender keeps a separate congestion control parameter set for 746 * each of the destination addresses it can send to (not each 747 * source-destination pair but for each destination). The parameters 748 * should decay if the address is not used for a long enough time 749 * period. 750 * 751 */ 752struct sctp_transport { 753 /* A list of transports. */ 754 struct list_head transports; 755 struct rhash_head node; 756 757 /* Reference counting. */ 758 atomic_t refcnt; 759 /* RTO-Pending : A flag used to track if one of the DATA 760 * chunks sent to this address is currently being 761 * used to compute a RTT. If this flag is 0, 762 * the next DATA chunk sent to this destination 763 * should be used to compute a RTT and this flag 764 * should be set. Every time the RTT 765 * calculation completes (i.e. the DATA chunk 766 * is SACK'd) clear this flag. 767 */ 768 __u32 rto_pending:1, 769 770 /* 771 * hb_sent : a flag that signals that we have a pending 772 * heartbeat. 773 */ 774 hb_sent:1, 775 776 /* Is the Path MTU update pending on this tranport */ 777 pmtu_pending:1, 778 779 /* Has this transport moved the ctsn since we last sacked */ 780 sack_generation:1; 781 u32 dst_cookie; 782 783 struct flowi fl; 784 785 /* This is the peer's IP address and port. */ 786 union sctp_addr ipaddr; 787 788 /* These are the functions we call to handle LLP stuff. */ 789 struct sctp_af *af_specific; 790 791 /* Which association do we belong to? */ 792 struct sctp_association *asoc; 793 794 /* RFC2960 795 * 796 * 12.3 Per Transport Address Data 797 * 798 * For each destination transport address in the peer's 799 * address list derived from the INIT or INIT ACK chunk, a 800 * number of data elements needs to be maintained including: 801 */ 802 /* RTO : The current retransmission timeout value. */ 803 unsigned long rto; 804 805 __u32 rtt; /* This is the most recent RTT. */ 806 807 /* RTTVAR : The current RTT variation. */ 808 __u32 rttvar; 809 810 /* SRTT : The current smoothed round trip time. */ 811 __u32 srtt; 812 813 /* 814 * These are the congestion stats. 815 */ 816 /* cwnd : The current congestion window. */ 817 __u32 cwnd; /* This is the actual cwnd. */ 818 819 /* ssthresh : The current slow start threshold value. */ 820 __u32 ssthresh; 821 822 /* partial : The tracking method for increase of cwnd when in 823 * bytes acked : congestion avoidance mode (see Section 6.2.2) 824 */ 825 __u32 partial_bytes_acked; 826 827 /* Data that has been sent, but not acknowledged. */ 828 __u32 flight_size; 829 830 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */ 831 832 /* Destination */ 833 struct dst_entry *dst; 834 /* Source address. */ 835 union sctp_addr saddr; 836 837 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 838 * the destination address every heartbeat interval. 839 */ 840 unsigned long hbinterval; 841 842 /* SACK delay timeout */ 843 unsigned long sackdelay; 844 __u32 sackfreq; 845 846 /* When was the last time that we heard from this transport? We use 847 * this to pick new active and retran paths. 848 */ 849 ktime_t last_time_heard; 850 851 /* When was the last time that we sent a chunk using this 852 * transport? We use this to check for idle transports 853 */ 854 unsigned long last_time_sent; 855 856 /* Last time(in jiffies) when cwnd is reduced due to the congestion 857 * indication based on ECNE chunk. 858 */ 859 unsigned long last_time_ecne_reduced; 860 861 /* This is the max_retrans value for the transport and will 862 * be initialized from the assocs value. This can be changed 863 * using the SCTP_SET_PEER_ADDR_PARAMS socket option. 864 */ 865 __u16 pathmaxrxt; 866 867 /* This is the partially failed retrans value for the transport 868 * and will be initialized from the assocs value. This can be changed 869 * using the SCTP_PEER_ADDR_THLDS socket option 870 */ 871 int pf_retrans; 872 /* PMTU : The current known path MTU. */ 873 __u32 pathmtu; 874 875 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ 876 __u32 param_flags; 877 878 /* The number of times INIT has been sent on this transport. */ 879 int init_sent_count; 880 881 /* state : The current state of this destination, 882 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN. 883 */ 884 int state; 885 886 /* These are the error stats for this destination. */ 887 888 /* Error count : The current error count for this destination. */ 889 unsigned short error_count; 890 891 /* Per : A timer used by each destination. 892 * Destination : 893 * Timer : 894 * 895 * [Everywhere else in the text this is called T3-rtx. -ed] 896 */ 897 struct timer_list T3_rtx_timer; 898 899 /* Heartbeat timer is per destination. */ 900 struct timer_list hb_timer; 901 902 /* Timer to handle ICMP proto unreachable envets */ 903 struct timer_list proto_unreach_timer; 904 905 /* Since we're using per-destination retransmission timers 906 * (see above), we're also using per-destination "transmitted" 907 * queues. This probably ought to be a private struct 908 * accessible only within the outqueue, but it's not, yet. 909 */ 910 struct list_head transmitted; 911 912 /* We build bundle-able packets for this transport here. */ 913 struct sctp_packet packet; 914 915 /* This is the list of transports that have chunks to send. */ 916 struct list_head send_ready; 917 918 /* State information saved for SFR_CACC algorithm. The key 919 * idea in SFR_CACC is to maintain state at the sender on a 920 * per-destination basis when a changeover happens. 921 * char changeover_active; 922 * char cycling_changeover; 923 * __u32 next_tsn_at_change; 924 * char cacc_saw_newack; 925 */ 926 struct { 927 /* An unsigned integer, which stores the next TSN to be 928 * used by the sender, at the moment of changeover. 929 */ 930 __u32 next_tsn_at_change; 931 932 /* A flag which indicates the occurrence of a changeover */ 933 char changeover_active; 934 935 /* A flag which indicates whether the change of primary is 936 * the first switch to this destination address during an 937 * active switch. 938 */ 939 char cycling_changeover; 940 941 /* A temporary flag, which is used during the processing of 942 * a SACK to estimate the causative TSN(s)'s group. 943 */ 944 char cacc_saw_newack; 945 } cacc; 946 947 /* 64-bit random number sent with heartbeat. */ 948 __u64 hb_nonce; 949 950 struct rcu_head rcu; 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_t3_rtx(struct sctp_transport *); 962void sctp_transport_reset_hb_timer(struct sctp_transport *); 963int sctp_transport_hold(struct sctp_transport *); 964void sctp_transport_put(struct sctp_transport *); 965void sctp_transport_update_rto(struct sctp_transport *, __u32); 966void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32); 967void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t); 968void sctp_transport_burst_limited(struct sctp_transport *); 969void sctp_transport_burst_reset(struct sctp_transport *); 970unsigned long sctp_transport_timeout(struct sctp_transport *); 971void sctp_transport_reset(struct sctp_transport *); 972void sctp_transport_update_pmtu(struct sock *, struct sctp_transport *, u32); 973void sctp_transport_immediate_rtx(struct sctp_transport *); 974 975 976/* This is the structure we use to queue packets as they come into 977 * SCTP. We write packets to it and read chunks from it. 978 */ 979struct sctp_inq { 980 /* This is actually a queue of sctp_chunk each 981 * containing a partially decoded packet. 982 */ 983 struct list_head in_chunk_list; 984 /* This is the packet which is currently off the in queue and is 985 * being worked on through the inbound chunk processing. 986 */ 987 struct sctp_chunk *in_progress; 988 989 /* This is the delayed task to finish delivering inbound 990 * messages. 991 */ 992 struct work_struct immediate; 993}; 994 995void sctp_inq_init(struct sctp_inq *); 996void sctp_inq_free(struct sctp_inq *); 997void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet); 998struct sctp_chunk *sctp_inq_pop(struct sctp_inq *); 999struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *); 1000void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1001 1002/* This is the structure we use to hold outbound chunks. You push 1003 * chunks in and they automatically pop out the other end as bundled 1004 * packets (it calls (*output_handler)()). 1005 * 1006 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1, 1007 * and 8.2 of the v13 draft. 1008 * 1009 * It handles retransmissions. The connection to the timeout portion 1010 * of the state machine is through sctp_..._timeout() and timeout_handler. 1011 * 1012 * If you feed it SACKs, it will eat them. 1013 * 1014 * If you give it big chunks, it will fragment them. 1015 * 1016 * It assigns TSN's to data chunks. This happens at the last possible 1017 * instant before transmission. 1018 * 1019 * When free()'d, it empties itself out via output_handler(). 1020 */ 1021struct sctp_outq { 1022 struct sctp_association *asoc; 1023 1024 /* Data pending that has never been transmitted. */ 1025 struct list_head out_chunk_list; 1026 1027 unsigned int out_qlen; /* Total length of queued data chunks. */ 1028 1029 /* Error of send failed, may used in SCTP_SEND_FAILED event. */ 1030 unsigned int error; 1031 1032 /* These are control chunks we want to send. */ 1033 struct list_head control_chunk_list; 1034 1035 /* These are chunks that have been sacked but are above the 1036 * CTSN, or cumulative tsn ack point. 1037 */ 1038 struct list_head sacked; 1039 1040 /* Put chunks on this list to schedule them for 1041 * retransmission. 1042 */ 1043 struct list_head retransmit; 1044 1045 /* Put chunks on this list to save them for FWD TSN processing as 1046 * they were abandoned. 1047 */ 1048 struct list_head abandoned; 1049 1050 /* How many unackd bytes do we have in-flight? */ 1051 __u32 outstanding_bytes; 1052 1053 /* Are we doing fast-rtx on this queue */ 1054 char fast_rtx; 1055 1056 /* Corked? */ 1057 char cork; 1058}; 1059 1060void sctp_outq_init(struct sctp_association *, struct sctp_outq *); 1061void sctp_outq_teardown(struct sctp_outq *); 1062void sctp_outq_free(struct sctp_outq*); 1063int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t); 1064int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *); 1065int sctp_outq_is_empty(const struct sctp_outq *); 1066void sctp_outq_restart(struct sctp_outq *); 1067 1068void sctp_retransmit(struct sctp_outq *, struct sctp_transport *, 1069 sctp_retransmit_reason_t); 1070void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); 1071int sctp_outq_uncork(struct sctp_outq *, gfp_t gfp); 1072/* Uncork and flush an outqueue. */ 1073static inline void sctp_outq_cork(struct sctp_outq *q) 1074{ 1075 q->cork = 1; 1076} 1077 1078/* These bind address data fields common between endpoints and associations */ 1079struct sctp_bind_addr { 1080 1081 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1082 * 1083 * SCTP Port: The local SCTP port number the endpoint is 1084 * bound to. 1085 */ 1086 __u16 port; 1087 1088 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1089 * 1090 * Address List: The list of IP addresses that this instance 1091 * has bound. This information is passed to one's 1092 * peer(s) in INIT and INIT ACK chunks. 1093 */ 1094 struct list_head address_list; 1095}; 1096 1097void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port); 1098void sctp_bind_addr_free(struct sctp_bind_addr *); 1099int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest, 1100 const struct sctp_bind_addr *src, 1101 sctp_scope_t scope, gfp_t gfp, 1102 int flags); 1103int sctp_bind_addr_dup(struct sctp_bind_addr *dest, 1104 const struct sctp_bind_addr *src, 1105 gfp_t gfp); 1106int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1107 int new_size, __u8 addr_state, gfp_t gfp); 1108int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *); 1109int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, 1110 struct sctp_sock *); 1111int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *, 1112 struct sctp_sock *, struct sctp_sock *); 1113int sctp_bind_addr_state(const struct sctp_bind_addr *bp, 1114 const union sctp_addr *addr); 1115union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 1116 const union sctp_addr *addrs, 1117 int addrcnt, 1118 struct sctp_sock *opt); 1119union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 1120 int *addrs_len, 1121 gfp_t gfp); 1122int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, 1123 __u16 port, gfp_t gfp); 1124 1125sctp_scope_t sctp_scope(const union sctp_addr *); 1126int sctp_in_scope(struct net *net, const union sctp_addr *addr, const sctp_scope_t scope); 1127int sctp_is_any(struct sock *sk, const union sctp_addr *addr); 1128int sctp_is_ep_boundall(struct sock *sk); 1129 1130 1131/* What type of endpoint? */ 1132typedef enum { 1133 SCTP_EP_TYPE_SOCKET, 1134 SCTP_EP_TYPE_ASSOCIATION, 1135} sctp_endpoint_type_t; 1136 1137/* 1138 * A common base class to bridge the implmentation view of a 1139 * socket (usually listening) endpoint versus an association's 1140 * local endpoint. 1141 * This common structure is useful for several purposes: 1142 * 1) Common interface for lookup routines. 1143 * a) Subfunctions work for either endpoint or association 1144 * b) Single interface to lookup allows hiding the lookup lock rather 1145 * than acquiring it externally. 1146 * 2) Common interface for the inbound chunk handling/state machine. 1147 * 3) Common object handling routines for reference counting, etc. 1148 * 4) Disentangle association lookup from endpoint lookup, where we 1149 * do not have to find our endpoint to find our association. 1150 * 1151 */ 1152 1153struct sctp_ep_common { 1154 /* Fields to help us manage our entries in the hash tables. */ 1155 struct hlist_node node; 1156 int hashent; 1157 1158 /* Runtime type information. What kind of endpoint is this? */ 1159 sctp_endpoint_type_t type; 1160 1161 /* Some fields to help us manage this object. 1162 * refcnt - Reference count access to this object. 1163 * dead - Do not attempt to use this object. 1164 */ 1165 atomic_t refcnt; 1166 bool dead; 1167 1168 /* What socket does this endpoint belong to? */ 1169 struct sock *sk; 1170 1171 /* This is where we receive inbound chunks. */ 1172 struct sctp_inq inqueue; 1173 1174 /* This substructure includes the defining parameters of the 1175 * endpoint: 1176 * bind_addr.port is our shared port number. 1177 * bind_addr.address_list is our set of local IP addresses. 1178 */ 1179 struct sctp_bind_addr bind_addr; 1180}; 1181 1182 1183/* RFC Section 1.4 Key Terms 1184 * 1185 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a 1186 * multi-homed host, an SCTP endpoint is represented to its peers as a 1187 * combination of a set of eligible destination transport addresses to 1188 * which SCTP packets can be sent and a set of eligible source 1189 * transport addresses from which SCTP packets can be received. 1190 * All transport addresses used by an SCTP endpoint must use the 1191 * same port number, but can use multiple IP addresses. A transport 1192 * address used by an SCTP endpoint must not be used by another 1193 * SCTP endpoint. In other words, a transport address is unique 1194 * to an SCTP endpoint. 1195 * 1196 * From an implementation perspective, each socket has one of these. 1197 * A TCP-style socket will have exactly one association on one of 1198 * these. An UDP-style socket will have multiple associations hanging 1199 * off one of these. 1200 */ 1201 1202struct sctp_endpoint { 1203 /* Common substructure for endpoint and association. */ 1204 struct sctp_ep_common base; 1205 1206 /* Associations: A list of current associations and mappings 1207 * to the data consumers for each association. This 1208 * may be in the form of a hash table or other 1209 * implementation dependent structure. The data 1210 * consumers may be process identification 1211 * information such as file descriptors, named pipe 1212 * pointer, or table pointers dependent on how SCTP 1213 * is implemented. 1214 */ 1215 /* This is really a list of struct sctp_association entries. */ 1216 struct list_head asocs; 1217 1218 /* Secret Key: A secret key used by this endpoint to compute 1219 * the MAC. This SHOULD be a cryptographic quality 1220 * random number with a sufficient length. 1221 * Discussion in [RFC1750] can be helpful in 1222 * selection of the key. 1223 */ 1224 __u8 secret_key[SCTP_SECRET_SIZE]; 1225 1226 /* digest: This is a digest of the sctp cookie. This field is 1227 * only used on the receive path when we try to validate 1228 * that the cookie has not been tampered with. We put 1229 * this here so we pre-allocate this once and can re-use 1230 * on every receive. 1231 */ 1232 __u8 *digest; 1233 1234 /* sendbuf acct. policy. */ 1235 __u32 sndbuf_policy; 1236 1237 /* rcvbuf acct. policy. */ 1238 __u32 rcvbuf_policy; 1239 1240 /* SCTP AUTH: array of the HMACs that will be allocated 1241 * we need this per association so that we don't serialize 1242 */ 1243 struct crypto_shash **auth_hmacs; 1244 1245 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */ 1246 struct sctp_hmac_algo_param *auth_hmacs_list; 1247 1248 /* SCTP-AUTH: chunks to authenticate encoded into parameter */ 1249 struct sctp_chunks_param *auth_chunk_list; 1250 1251 /* SCTP-AUTH: endpoint shared keys */ 1252 struct list_head endpoint_shared_keys; 1253 __u16 active_key_id; 1254 __u8 auth_enable; 1255}; 1256 1257/* Recover the outter endpoint structure. */ 1258static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) 1259{ 1260 struct sctp_endpoint *ep; 1261 1262 ep = container_of(base, struct sctp_endpoint, base); 1263 return ep; 1264} 1265 1266/* These are function signatures for manipulating endpoints. */ 1267struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t); 1268void sctp_endpoint_free(struct sctp_endpoint *); 1269void sctp_endpoint_put(struct sctp_endpoint *); 1270void sctp_endpoint_hold(struct sctp_endpoint *); 1271void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); 1272struct sctp_association *sctp_endpoint_lookup_assoc( 1273 const struct sctp_endpoint *ep, 1274 const union sctp_addr *paddr, 1275 struct sctp_transport **); 1276int sctp_endpoint_is_peeled_off(struct sctp_endpoint *, 1277 const union sctp_addr *); 1278struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *, 1279 struct net *, const union sctp_addr *); 1280int sctp_has_association(struct net *net, const union sctp_addr *laddr, 1281 const union sctp_addr *paddr); 1282 1283int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 1284 const struct sctp_association *asoc, 1285 sctp_cid_t, sctp_init_chunk_t *peer_init, 1286 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk); 1287int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk, 1288 const union sctp_addr *peer, 1289 sctp_init_chunk_t *init, gfp_t gfp); 1290__u32 sctp_generate_tag(const struct sctp_endpoint *); 1291__u32 sctp_generate_tsn(const struct sctp_endpoint *); 1292 1293struct sctp_inithdr_host { 1294 __u32 init_tag; 1295 __u32 a_rwnd; 1296 __u16 num_outbound_streams; 1297 __u16 num_inbound_streams; 1298 __u32 initial_tsn; 1299}; 1300 1301/* SCTP_GET_ASSOC_STATS counters */ 1302struct sctp_priv_assoc_stats { 1303 /* Maximum observed rto in the association during subsequent 1304 * observations. Value is set to 0 if no RTO measurement took place 1305 * The transport where the max_rto was observed is returned in 1306 * obs_rto_ipaddr 1307 */ 1308 struct sockaddr_storage obs_rto_ipaddr; 1309 __u64 max_obs_rto; 1310 /* Total In and Out SACKs received and sent */ 1311 __u64 isacks; 1312 __u64 osacks; 1313 /* Total In and Out packets received and sent */ 1314 __u64 opackets; 1315 __u64 ipackets; 1316 /* Total retransmitted chunks */ 1317 __u64 rtxchunks; 1318 /* TSN received > next expected */ 1319 __u64 outofseqtsns; 1320 /* Duplicate Chunks received */ 1321 __u64 idupchunks; 1322 /* Gap Ack Blocks received */ 1323 __u64 gapcnt; 1324 /* Unordered data chunks sent and received */ 1325 __u64 ouodchunks; 1326 __u64 iuodchunks; 1327 /* Ordered data chunks sent and received */ 1328 __u64 oodchunks; 1329 __u64 iodchunks; 1330 /* Control chunks sent and received */ 1331 __u64 octrlchunks; 1332 __u64 ictrlchunks; 1333}; 1334 1335/* RFC2960 1336 * 1337 * 12. Recommended Transmission Control Block (TCB) Parameters 1338 * 1339 * This section details a recommended set of parameters that should 1340 * be contained within the TCB for an implementation. This section is 1341 * for illustrative purposes and should not be deemed as requirements 1342 * on an implementation or as an exhaustive list of all parameters 1343 * inside an SCTP TCB. Each implementation may need its own additional 1344 * parameters for optimization. 1345 */ 1346 1347 1348/* Here we have information about each individual association. */ 1349struct sctp_association { 1350 1351 /* A base structure common to endpoint and association. 1352 * In this context, it represents the associations's view 1353 * of the local endpoint of the association. 1354 */ 1355 struct sctp_ep_common base; 1356 1357 /* Associations on the same socket. */ 1358 struct list_head asocs; 1359 1360 /* association id. */ 1361 sctp_assoc_t assoc_id; 1362 1363 /* This is our parent endpoint. */ 1364 struct sctp_endpoint *ep; 1365 1366 /* These are those association elements needed in the cookie. */ 1367 struct sctp_cookie c; 1368 1369 /* This is all information about our peer. */ 1370 struct { 1371 /* transport_addr_list 1372 * 1373 * Peer : A list of SCTP transport addresses that the 1374 * Transport : peer is bound to. This information is derived 1375 * Address : from the INIT or INIT ACK and is used to 1376 * List : associate an inbound packet with a given 1377 * : association. Normally this information is 1378 * : hashed or keyed for quick lookup and access 1379 * : of the TCB. 1380 * : The list is also initialized with the list 1381 * : of addresses passed with the sctp_connectx() 1382 * : call. 1383 * 1384 * It is a list of SCTP_transport's. 1385 */ 1386 struct list_head transport_addr_list; 1387 1388 /* rwnd 1389 * 1390 * Peer Rwnd : Current calculated value of the peer's rwnd. 1391 */ 1392 __u32 rwnd; 1393 1394 /* transport_count 1395 * 1396 * Peer : A count of the number of peer addresses 1397 * Transport : in the Peer Transport Address List. 1398 * Address : 1399 * Count : 1400 */ 1401 __u16 transport_count; 1402 1403 /* port 1404 * The transport layer port number. 1405 */ 1406 __u16 port; 1407 1408 /* primary_path 1409 * 1410 * Primary : This is the current primary destination 1411 * Path : transport address of the peer endpoint. It 1412 * : may also specify a source transport address 1413 * : on this endpoint. 1414 * 1415 * All of these paths live on transport_addr_list. 1416 * 1417 * At the bakeoffs, we discovered that the intent of 1418 * primaryPath is that it only changes when the ULP 1419 * asks to have it changed. We add the activePath to 1420 * designate the connection we are currently using to 1421 * transmit new data and most control chunks. 1422 */ 1423 struct sctp_transport *primary_path; 1424 1425 /* Cache the primary path address here, when we 1426 * need a an address for msg_name. 1427 */ 1428 union sctp_addr primary_addr; 1429 1430 /* active_path 1431 * The path that we are currently using to 1432 * transmit new data and most control chunks. 1433 */ 1434 struct sctp_transport *active_path; 1435 1436 /* retran_path 1437 * 1438 * RFC2960 6.4 Multi-homed SCTP Endpoints 1439 * ... 1440 * Furthermore, when its peer is multi-homed, an 1441 * endpoint SHOULD try to retransmit a chunk to an 1442 * active destination transport address that is 1443 * different from the last destination address to 1444 * which the DATA chunk was sent. 1445 */ 1446 struct sctp_transport *retran_path; 1447 1448 /* Pointer to last transport I have sent on. */ 1449 struct sctp_transport *last_sent_to; 1450 1451 /* This is the last transport I have received DATA on. */ 1452 struct sctp_transport *last_data_from; 1453 1454 /* 1455 * Mapping An array of bits or bytes indicating which out of 1456 * Array order TSN's have been received (relative to the 1457 * Last Rcvd TSN). If no gaps exist, i.e. no out of 1458 * order packets have been received, this array 1459 * will be set to all zero. This structure may be 1460 * in the form of a circular buffer or bit array. 1461 * 1462 * Last Rcvd : This is the last TSN received in 1463 * TSN : sequence. This value is set initially by 1464 * : taking the peer's Initial TSN, received in 1465 * : the INIT or INIT ACK chunk, and subtracting 1466 * : one from it. 1467 * 1468 * Throughout most of the specification this is called the 1469 * "Cumulative TSN ACK Point". In this case, we 1470 * ignore the advice in 12.2 in favour of the term 1471 * used in the bulk of the text. This value is hidden 1472 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). 1473 */ 1474 struct sctp_tsnmap tsn_map; 1475 1476 /* This mask is used to disable sending the ASCONF chunk 1477 * with specified parameter to peer. 1478 */ 1479 __be16 addip_disabled_mask; 1480 1481 /* These are capabilities which our peer advertised. */ 1482 __u8 ecn_capable:1, /* Can peer do ECN? */ 1483 ipv4_address:1, /* Peer understands IPv4 addresses? */ 1484 ipv6_address:1, /* Peer understands IPv6 addresses? */ 1485 hostname_address:1, /* Peer understands DNS addresses? */ 1486 asconf_capable:1, /* Does peer support ADDIP? */ 1487 prsctp_capable:1, /* Can peer do PR-SCTP? */ 1488 auth_capable:1; /* Is peer doing SCTP-AUTH? */ 1489 1490 /* sack_needed : This flag indicates if the next received 1491 * : packet is to be responded to with a 1492 * : SACK. This is initialized to 0. When a packet 1493 * : is received sack_cnt is incremented. If this value 1494 * : reaches 2 or more, a SACK is sent and the 1495 * : value is reset to 0. Note: This is used only 1496 * : when no DATA chunks are received out of 1497 * : order. When DATA chunks are out of order, 1498 * : SACK's are not delayed (see Section 6). 1499 */ 1500 __u8 sack_needed:1, /* Do we need to sack the peer? */ 1501 sack_generation:1, 1502 zero_window_announced:1; 1503 __u32 sack_cnt; 1504 1505 __u32 adaptation_ind; /* Adaptation Code point. */ 1506 1507 struct sctp_inithdr_host i; 1508 void *cookie; 1509 int cookie_len; 1510 1511 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1512 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the 1513 * Initial TSN Value minus 1 1514 */ 1515 __u32 addip_serial; 1516 1517 /* SCTP-AUTH: We need to know pears random number, hmac list 1518 * and authenticated chunk list. All that is part of the 1519 * cookie and these are just pointers to those locations 1520 */ 1521 sctp_random_param_t *peer_random; 1522 sctp_chunks_param_t *peer_chunks; 1523 sctp_hmac_algo_param_t *peer_hmacs; 1524 } peer; 1525 1526 /* State : A state variable indicating what state the 1527 * : association is in, i.e. COOKIE-WAIT, 1528 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, 1529 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. 1530 * 1531 * Note: No "CLOSED" state is illustrated since if a 1532 * association is "CLOSED" its TCB SHOULD be removed. 1533 * 1534 * In this implementation we DO have a CLOSED 1535 * state which is used during initiation and shutdown. 1536 * 1537 * State takes values from SCTP_STATE_*. 1538 */ 1539 sctp_state_t state; 1540 1541 /* Overall : The overall association error count. 1542 * Error Count : [Clear this any time I get something.] 1543 */ 1544 int overall_error_count; 1545 1546 /* The cookie life I award for any cookie. */ 1547 ktime_t cookie_life; 1548 1549 /* These are the association's initial, max, and min RTO values. 1550 * These values will be initialized by system defaults, but can 1551 * be modified via the SCTP_RTOINFO socket option. 1552 */ 1553 unsigned long rto_initial; 1554 unsigned long rto_max; 1555 unsigned long rto_min; 1556 1557 /* Maximum number of new data packets that can be sent in a burst. */ 1558 int max_burst; 1559 1560 /* This is the max_retrans value for the association. This value will 1561 * be initialized initialized from system defaults, but can be 1562 * modified by the SCTP_ASSOCINFO socket option. 1563 */ 1564 int max_retrans; 1565 1566 /* This is the partially failed retrans value for the transport 1567 * and will be initialized from the assocs value. This can be 1568 * changed using the SCTP_PEER_ADDR_THLDS socket option 1569 */ 1570 int pf_retrans; 1571 1572 /* Maximum number of times the endpoint will retransmit INIT */ 1573 __u16 max_init_attempts; 1574 1575 /* How many times have we resent an INIT? */ 1576 __u16 init_retries; 1577 1578 /* The largest timeout or RTO value to use in attempting an INIT */ 1579 unsigned long max_init_timeo; 1580 1581 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 1582 * the destination address every heartbeat interval. This value 1583 * will be inherited by all new transports. 1584 */ 1585 unsigned long hbinterval; 1586 1587 /* This is the max_retrans value for new transports in the 1588 * association. 1589 */ 1590 __u16 pathmaxrxt; 1591 1592 /* Flag that path mtu update is pending */ 1593 __u8 pmtu_pending; 1594 1595 /* Association : The smallest PMTU discovered for all of the 1596 * PMTU : peer's transport addresses. 1597 */ 1598 __u32 pathmtu; 1599 1600 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ 1601 __u32 param_flags; 1602 1603 __u32 sackfreq; 1604 /* SACK delay timeout */ 1605 unsigned long sackdelay; 1606 1607 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1608 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; 1609 1610 /* Transport to which SHUTDOWN chunk was last sent. */ 1611 struct sctp_transport *shutdown_last_sent_to; 1612 1613 /* Transport to which INIT chunk was last sent. */ 1614 struct sctp_transport *init_last_sent_to; 1615 1616 /* How many times have we resent a SHUTDOWN */ 1617 int shutdown_retries; 1618 1619 /* Next TSN : The next TSN number to be assigned to a new 1620 * : DATA chunk. This is sent in the INIT or INIT 1621 * : ACK chunk to the peer and incremented each 1622 * : time a DATA chunk is assigned a TSN 1623 * : (normally just prior to transmit or during 1624 * : fragmentation). 1625 */ 1626 __u32 next_tsn; 1627 1628 /* 1629 * Last Rcvd : This is the last TSN received in sequence. This value 1630 * TSN : is set initially by taking the peer's Initial TSN, 1631 * : received in the INIT or INIT ACK chunk, and 1632 * : subtracting one from it. 1633 * 1634 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. 1635 */ 1636 1637 __u32 ctsn_ack_point; 1638 1639 /* PR-SCTP Advanced.Peer.Ack.Point */ 1640 __u32 adv_peer_ack_point; 1641 1642 /* Highest TSN that is acknowledged by incoming SACKs. */ 1643 __u32 highest_sacked; 1644 1645 /* TSN marking the fast recovery exit point */ 1646 __u32 fast_recovery_exit; 1647 1648 /* Flag to track the current fast recovery state */ 1649 __u8 fast_recovery; 1650 1651 /* The number of unacknowledged data chunks. Reported through 1652 * the SCTP_STATUS sockopt. 1653 */ 1654 __u16 unack_data; 1655 1656 /* The total number of data chunks that we've had to retransmit 1657 * as the result of a T3 timer expiration 1658 */ 1659 __u32 rtx_data_chunks; 1660 1661 /* This is the association's receive buffer space. This value is used 1662 * to set a_rwnd field in an INIT or a SACK chunk. 1663 */ 1664 __u32 rwnd; 1665 1666 /* This is the last advertised value of rwnd over a SACK chunk. */ 1667 __u32 a_rwnd; 1668 1669 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed 1670 * to slop over a maximum of the association's frag_point. 1671 */ 1672 __u32 rwnd_over; 1673 1674 /* Keeps treack of rwnd pressure. This happens when we have 1675 * a window, but not recevie buffer (i.e small packets). This one 1676 * is releases slowly (1 PMTU at a time ). 1677 */ 1678 __u32 rwnd_press; 1679 1680 /* This is the sndbuf size in use for the association. 1681 * This corresponds to the sndbuf size for the association, 1682 * as specified in the sk->sndbuf. 1683 */ 1684 int sndbuf_used; 1685 1686 /* This is the amount of memory that this association has allocated 1687 * in the receive path at any given time. 1688 */ 1689 atomic_t rmem_alloc; 1690 1691 /* This is the wait queue head for send requests waiting on 1692 * the association sndbuf space. 1693 */ 1694 wait_queue_head_t wait; 1695 1696 /* The message size at which SCTP fragmentation will occur. */ 1697 __u32 frag_point; 1698 __u32 user_frag; 1699 1700 /* Counter used to count INIT errors. */ 1701 int init_err_counter; 1702 1703 /* Count the number of INIT cycles (for doubling timeout). */ 1704 int init_cycle; 1705 1706 /* Default send parameters. */ 1707 __u16 default_stream; 1708 __u16 default_flags; 1709 __u32 default_ppid; 1710 __u32 default_context; 1711 __u32 default_timetolive; 1712 1713 /* Default receive parameters */ 1714 __u32 default_rcv_context; 1715 1716 /* This tracks outbound ssn for a given stream. */ 1717 struct sctp_ssnmap *ssnmap; 1718 1719 /* All outbound chunks go through this structure. */ 1720 struct sctp_outq outqueue; 1721 1722 /* A smart pipe that will handle reordering and fragmentation, 1723 * as well as handle passing events up to the ULP. 1724 */ 1725 struct sctp_ulpq ulpq; 1726 1727 /* Last TSN that caused an ECNE Chunk to be sent. */ 1728 __u32 last_ecne_tsn; 1729 1730 /* Last TSN that caused a CWR Chunk to be sent. */ 1731 __u32 last_cwr_tsn; 1732 1733 /* How many duplicated TSNs have we seen? */ 1734 int numduptsns; 1735 1736 /* These are to support 1737 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses 1738 * and Enforcement of Flow and Message Limits" 1739 * <draft-ietf-tsvwg-addip-sctp-02.txt> 1740 * or "ADDIP" for short. 1741 */ 1742 1743 1744 1745 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1746 * 1747 * R1) One and only one ASCONF Chunk MAY be in transit and 1748 * unacknowledged at any one time. If a sender, after sending 1749 * an ASCONF chunk, decides it needs to transfer another 1750 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1751 * returns from the previous ASCONF Chunk before sending a 1752 * subsequent ASCONF. Note this restriction binds each side, 1753 * so at any time two ASCONF may be in-transit on any given 1754 * association (one sent from each endpoint). 1755 * 1756 * [This is our one-and-only-one ASCONF in flight. If we do 1757 * not have an ASCONF in flight, this is NULL.] 1758 */ 1759 struct sctp_chunk *addip_last_asconf; 1760 1761 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk. 1762 * 1763 * This is needed to implement itmes E1 - E4 of the updated 1764 * spec. Here is the justification: 1765 * 1766 * Since the peer may bundle multiple ASCONF chunks toward us, 1767 * we now need the ability to cache multiple ACKs. The section 1768 * describes in detail how they are cached and cleaned up. 1769 */ 1770 struct list_head asconf_ack_list; 1771 1772 /* These ASCONF chunks are waiting to be sent. 1773 * 1774 * These chunaks can't be pushed to outqueue until receiving 1775 * ASCONF_ACK for the previous ASCONF indicated by 1776 * addip_last_asconf, so as to guarantee that only one ASCONF 1777 * is in flight at any time. 1778 * 1779 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1780 * 1781 * In defining the ASCONF Chunk transfer procedures, it is 1782 * essential that these transfers MUST NOT cause congestion 1783 * within the network. To achieve this, we place these 1784 * restrictions on the transfer of ASCONF Chunks: 1785 * 1786 * R1) One and only one ASCONF Chunk MAY be in transit and 1787 * unacknowledged at any one time. If a sender, after sending 1788 * an ASCONF chunk, decides it needs to transfer another 1789 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1790 * returns from the previous ASCONF Chunk before sending a 1791 * subsequent ASCONF. Note this restriction binds each side, 1792 * so at any time two ASCONF may be in-transit on any given 1793 * association (one sent from each endpoint). 1794 * 1795 * 1796 * [I really think this is EXACTLY the sort of intelligence 1797 * which already resides in sctp_outq. Please move this 1798 * queue and its supporting logic down there. --piggy] 1799 */ 1800 struct list_head addip_chunk_list; 1801 1802 /* ADDIP Section 4.1 ASCONF Chunk Procedures 1803 * 1804 * A2) A serial number should be assigned to the Chunk. The 1805 * serial number SHOULD be a monotonically increasing 1806 * number. The serial number SHOULD be initialized at 1807 * the start of the association to the same value as the 1808 * Initial TSN and every time a new ASCONF chunk is created 1809 * it is incremented by one after assigning the serial number 1810 * to the newly created chunk. 1811 * 1812 * ADDIP 1813 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) 1814 * 1815 * Serial Number : 32 bits (unsigned integer) 1816 * 1817 * This value represents a Serial Number for the ASCONF 1818 * Chunk. The valid range of Serial Number is from 0 to 1819 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 1820 * after reaching 4294967295. 1821 */ 1822 __u32 addip_serial; 1823 int src_out_of_asoc_ok; 1824 union sctp_addr *asconf_addr_del_pending; 1825 struct sctp_transport *new_transport; 1826 1827 /* SCTP AUTH: list of the endpoint shared keys. These 1828 * keys are provided out of band by the user applicaton 1829 * and can't change during the lifetime of the association 1830 */ 1831 struct list_head endpoint_shared_keys; 1832 1833 /* SCTP AUTH: 1834 * The current generated assocaition shared key (secret) 1835 */ 1836 struct sctp_auth_bytes *asoc_shared_key; 1837 1838 /* SCTP AUTH: hmac id of the first peer requested algorithm 1839 * that we support. 1840 */ 1841 __u16 default_hmac_id; 1842 1843 __u16 active_key_id; 1844 1845 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */ 1846 temp:1; /* Is it a temporary association? */ 1847 1848 struct sctp_priv_assoc_stats stats; 1849}; 1850 1851 1852/* An eyecatcher for determining if we are really looking at an 1853 * association data structure. 1854 */ 1855enum { 1856 SCTP_ASSOC_EYECATCHER = 0xa550c123, 1857}; 1858 1859/* Recover the outter association structure. */ 1860static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) 1861{ 1862 struct sctp_association *asoc; 1863 1864 asoc = container_of(base, struct sctp_association, base); 1865 return asoc; 1866} 1867 1868/* These are function signatures for manipulating associations. */ 1869 1870 1871struct sctp_association * 1872sctp_association_new(const struct sctp_endpoint *, const struct sock *, 1873 sctp_scope_t scope, gfp_t gfp); 1874void sctp_association_free(struct sctp_association *); 1875void sctp_association_put(struct sctp_association *); 1876void sctp_association_hold(struct sctp_association *); 1877 1878struct sctp_transport *sctp_assoc_choose_alter_transport( 1879 struct sctp_association *, struct sctp_transport *); 1880void sctp_assoc_update_retran_path(struct sctp_association *); 1881struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, 1882 const union sctp_addr *); 1883int sctp_assoc_lookup_laddr(struct sctp_association *asoc, 1884 const union sctp_addr *laddr); 1885struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, 1886 const union sctp_addr *address, 1887 const gfp_t gfp, 1888 const int peer_state); 1889void sctp_assoc_del_peer(struct sctp_association *asoc, 1890 const union sctp_addr *addr); 1891void sctp_assoc_rm_peer(struct sctp_association *asoc, 1892 struct sctp_transport *peer); 1893void sctp_assoc_control_transport(struct sctp_association *, 1894 struct sctp_transport *, 1895 sctp_transport_cmd_t, sctp_sn_error_t); 1896struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); 1897struct sctp_transport *sctp_assoc_is_match(struct sctp_association *, 1898 struct net *, 1899 const union sctp_addr *, 1900 const union sctp_addr *); 1901void sctp_assoc_migrate(struct sctp_association *, struct sock *); 1902void sctp_assoc_update(struct sctp_association *old, 1903 struct sctp_association *new); 1904 1905__u32 sctp_association_get_next_tsn(struct sctp_association *); 1906 1907void sctp_assoc_sync_pmtu(struct sock *, struct sctp_association *); 1908void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int); 1909void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int); 1910void sctp_assoc_set_primary(struct sctp_association *, 1911 struct sctp_transport *); 1912void sctp_assoc_del_nonprimary_peers(struct sctp_association *, 1913 struct sctp_transport *); 1914int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *, 1915 sctp_scope_t, gfp_t); 1916int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, 1917 struct sctp_cookie*, 1918 gfp_t gfp); 1919int sctp_assoc_set_id(struct sctp_association *, gfp_t); 1920void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc); 1921struct sctp_chunk *sctp_assoc_lookup_asconf_ack( 1922 const struct sctp_association *asoc, 1923 __be32 serial); 1924void sctp_asconf_queue_teardown(struct sctp_association *asoc); 1925 1926int sctp_cmp_addr_exact(const union sctp_addr *ss1, 1927 const union sctp_addr *ss2); 1928struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); 1929 1930/* A convenience structure to parse out SCTP specific CMSGs. */ 1931typedef struct sctp_cmsgs { 1932 struct sctp_initmsg *init; 1933 struct sctp_sndrcvinfo *srinfo; 1934 struct sctp_sndinfo *sinfo; 1935} sctp_cmsgs_t; 1936 1937/* Structure for tracking memory objects */ 1938typedef struct { 1939 char *label; 1940 atomic_t *counter; 1941} sctp_dbg_objcnt_entry_t; 1942 1943#endif /* __sctp_structs_h__ */ 1944