1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* SCTP kernel implementation 3 * (C) Copyright IBM Corp. 2001, 2004 4 * Copyright (c) 1999-2000 Cisco, Inc. 5 * Copyright (c) 1999-2001 Motorola, Inc. 6 * Copyright (c) 2001 Intel Corp. 7 * 8 * This file is part of the SCTP kernel implementation 9 * 10 * Please send any bug reports or fixes you make to the 11 * email addresses: 12 * lksctp developers <linux-sctp@vger.kernel.org> 13 * 14 * Written or modified by: 15 * Randall Stewart <randall@sctp.chicago.il.us> 16 * Ken Morneau <kmorneau@cisco.com> 17 * Qiaobing Xie <qxie1@email.mot.com> 18 * La Monte H.P. Yarroll <piggy@acm.org> 19 * Karl Knutson <karl@athena.chicago.il.us> 20 * Jon Grimm <jgrimm@us.ibm.com> 21 * Xingang Guo <xingang.guo@intel.com> 22 * Hui Huang <hui.huang@nokia.com> 23 * Sridhar Samudrala <sri@us.ibm.com> 24 * Daisy Chang <daisyc@us.ibm.com> 25 * Dajiang Zhang <dajiang.zhang@nokia.com> 26 * Ardelle Fan <ardelle.fan@intel.com> 27 * Ryan Layer <rmlayer@us.ibm.com> 28 * Anup Pemmaiah <pemmaiah@cc.usu.edu> 29 * Kevin Gao <kevin.gao@intel.com> 30 */ 31 32 #ifndef __sctp_structs_h__ 33 #define __sctp_structs_h__ 34 35 #include <linux/ktime.h> 36 #include <linux/generic-radix-tree.h> 37 #include <linux/rhashtable-types.h> 38 #include <linux/socket.h> /* linux/in.h needs this!! */ 39 #include <linux/in.h> /* We get struct sockaddr_in. */ 40 #include <linux/in6.h> /* We get struct in6_addr */ 41 #include <linux/ipv6.h> 42 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */ 43 #include <linux/atomic.h> /* This gets us atomic counters. */ 44 #include <linux/skbuff.h> /* We need sk_buff_head. */ 45 #include <linux/workqueue.h> /* We need tq_struct. */ 46 #include <linux/sctp.h> /* We need sctp* header structs. */ 47 #include <net/sctp/auth.h> /* We need auth specific structs */ 48 #include <net/ip.h> /* For inet_skb_parm */ 49 50 /* A convenience structure for handling sockaddr structures. 51 * We should wean ourselves off this. 52 */ 53 union sctp_addr { 54 struct sockaddr_in v4; 55 struct sockaddr_in6 v6; 56 struct sockaddr sa; 57 }; 58 59 /* Forward declarations for data structures. */ 60 struct sctp_globals; 61 struct sctp_endpoint; 62 struct sctp_association; 63 struct sctp_transport; 64 struct sctp_packet; 65 struct sctp_chunk; 66 struct sctp_inq; 67 struct sctp_outq; 68 struct sctp_bind_addr; 69 struct sctp_ulpq; 70 struct sctp_ep_common; 71 struct crypto_shash; 72 struct sctp_stream; 73 74 75 #include <net/sctp/tsnmap.h> 76 #include <net/sctp/ulpevent.h> 77 #include <net/sctp/ulpqueue.h> 78 #include <net/sctp/stream_interleave.h> 79 80 /* Structures useful for managing bind/connect. */ 81 82 struct sctp_bind_bucket { 83 unsigned short port; 84 signed char fastreuse; 85 signed char fastreuseport; 86 kuid_t fastuid; 87 struct hlist_node node; 88 struct hlist_head owner; 89 struct net *net; 90 }; 91 92 struct sctp_bind_hashbucket { 93 spinlock_t lock; 94 struct hlist_head chain; 95 }; 96 97 /* Used for hashing all associations. */ 98 struct sctp_hashbucket { 99 rwlock_t lock; 100 struct hlist_head chain; 101 } __attribute__((__aligned__(8))); 102 103 104 /* The SCTP globals structure. */ 105 extern struct sctp_globals { 106 /* This is a list of groups of functions for each address 107 * family that we support. 108 */ 109 struct list_head address_families; 110 111 /* This is the hash of all endpoints. */ 112 struct sctp_hashbucket *ep_hashtable; 113 /* This is the sctp port control hash. */ 114 struct sctp_bind_hashbucket *port_hashtable; 115 /* This is the hash of all transports. */ 116 struct rhltable transport_hashtable; 117 118 /* Sizes of above hashtables. */ 119 int ep_hashsize; 120 int port_hashsize; 121 122 /* Default initialization values to be applied to new associations. */ 123 __u16 max_instreams; 124 __u16 max_outstreams; 125 126 /* Flag to indicate whether computing and verifying checksum 127 * is disabled. */ 128 bool checksum_disable; 129 } sctp_globals; 130 131 #define sctp_max_instreams (sctp_globals.max_instreams) 132 #define sctp_max_outstreams (sctp_globals.max_outstreams) 133 #define sctp_address_families (sctp_globals.address_families) 134 #define sctp_ep_hashsize (sctp_globals.ep_hashsize) 135 #define sctp_ep_hashtable (sctp_globals.ep_hashtable) 136 #define sctp_port_hashsize (sctp_globals.port_hashsize) 137 #define sctp_port_hashtable (sctp_globals.port_hashtable) 138 #define sctp_transport_hashtable (sctp_globals.transport_hashtable) 139 #define sctp_checksum_disable (sctp_globals.checksum_disable) 140 141 /* SCTP Socket type: UDP or TCP style. */ 142 enum sctp_socket_type { 143 SCTP_SOCKET_UDP = 0, 144 SCTP_SOCKET_UDP_HIGH_BANDWIDTH, 145 SCTP_SOCKET_TCP 146 }; 147 148 /* Per socket SCTP information. */ 149 struct sctp_sock { 150 /* inet_sock has to be the first member of sctp_sock */ 151 struct inet_sock inet; 152 /* What kind of a socket is this? */ 153 enum sctp_socket_type type; 154 155 /* PF_ family specific functions. */ 156 struct sctp_pf *pf; 157 158 /* Access to HMAC transform. */ 159 struct crypto_shash *hmac; 160 char *sctp_hmac_alg; 161 162 /* What is our base endpointer? */ 163 struct sctp_endpoint *ep; 164 165 struct sctp_bind_bucket *bind_hash; 166 /* Various Socket Options. */ 167 __u16 default_stream; 168 __u32 default_ppid; 169 __u16 default_flags; 170 __u32 default_context; 171 __u32 default_timetolive; 172 __u32 default_rcv_context; 173 int max_burst; 174 175 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 176 * the destination address every heartbeat interval. This value 177 * will be inherited by all new associations. 178 */ 179 __u32 hbinterval; 180 __u32 probe_interval; 181 182 __be16 udp_port; 183 __be16 encap_port; 184 185 /* This is the max_retrans value for new associations. */ 186 __u16 pathmaxrxt; 187 188 __u32 flowlabel; 189 __u8 dscp; 190 191 __u16 pf_retrans; 192 __u16 ps_retrans; 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 __u32 default_ss; 205 206 struct sctp_rtoinfo rtoinfo; 207 struct sctp_paddrparams paddrparam; 208 struct sctp_assocparams assocparams; 209 210 /* 211 * These two structures must be grouped together for the usercopy 212 * whitelist region. 213 */ 214 __u16 subscribe; 215 struct sctp_initmsg initmsg; 216 217 int user_frag; 218 219 __u32 autoclose; 220 __u32 adaptation_ind; 221 __u32 pd_point; 222 __u16 nodelay:1, 223 pf_expose:2, 224 reuse:1, 225 disable_fragments:1, 226 v4mapped:1, 227 frag_interleave:1, 228 recvrcvinfo:1, 229 recvnxtinfo:1, 230 data_ready_signalled:1; 231 232 atomic_t pd_mode; 233 234 /* Fields after this point will be skipped on copies, like on accept 235 * and peeloff operations 236 */ 237 238 /* Receive to here while partial delivery is in effect. */ 239 struct sk_buff_head pd_lobby; 240 241 struct list_head auto_asconf_list; 242 int do_auto_asconf; 243 }; 244 245 #define sctp_sk(ptr) container_of_const(ptr, struct sctp_sock, inet.sk) 246 sctp_opt2sk(const struct sctp_sock * sp)247 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp) 248 { 249 return (struct sock *)sp; 250 } 251 252 #if IS_ENABLED(CONFIG_IPV6) 253 struct sctp6_sock { 254 struct sctp_sock sctp; 255 struct ipv6_pinfo inet6; 256 }; 257 #endif /* CONFIG_IPV6 */ 258 259 260 /* This is our APPLICATION-SPECIFIC state cookie. 261 * THIS IS NOT DICTATED BY THE SPECIFICATION. 262 */ 263 /* These are the parts of an association which we send in the cookie. 264 * Most of these are straight out of: 265 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB) 266 * 267 */ 268 269 struct sctp_cookie { 270 271 /* My : Tag expected in every inbound packet and sent 272 * Verification: in the INIT or INIT ACK chunk. 273 * Tag : 274 */ 275 __u32 my_vtag; 276 277 /* Peer's : Tag expected in every outbound packet except 278 * Verification: in the INIT chunk. 279 * Tag : 280 */ 281 __u32 peer_vtag; 282 283 /* The rest of these are not from the spec, but really need to 284 * be in the cookie. 285 */ 286 287 /* My Tie Tag : Assist in discovering a restarting association. */ 288 __u32 my_ttag; 289 290 /* Peer's Tie Tag: Assist in discovering a restarting association. */ 291 __u32 peer_ttag; 292 293 /* When does this cookie expire? */ 294 ktime_t expiration; 295 296 /* Number of inbound/outbound streams which are set 297 * and negotiated during the INIT process. 298 */ 299 __u16 sinit_num_ostreams; 300 __u16 sinit_max_instreams; 301 302 /* This is the first sequence number I used. */ 303 __u32 initial_tsn; 304 305 /* This holds the originating address of the INIT packet. */ 306 union sctp_addr peer_addr; 307 308 /* IG Section 2.35.3 309 * Include the source port of the INIT-ACK 310 */ 311 __u16 my_port; 312 313 __u8 prsctp_capable; 314 315 /* Padding for future use */ 316 __u8 padding; 317 318 __u32 adaptation_ind; 319 320 __u8 auth_random[sizeof(struct sctp_paramhdr) + 321 SCTP_AUTH_RANDOM_LENGTH]; 322 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2]; 323 __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS]; 324 325 /* This is a shim for my peer's INIT packet, followed by 326 * a copy of the raw address list of the association. 327 * The length of the raw address list is saved in the 328 * raw_addr_list_len field, which will be used at the time when 329 * the association TCB is re-constructed from the cookie. 330 */ 331 __u32 raw_addr_list_len; 332 /* struct sctp_init_chunk peer_init[]; */ 333 }; 334 335 336 /* The format of our cookie that we send to our peer. */ 337 struct sctp_signed_cookie { 338 __u8 signature[SCTP_SECRET_SIZE]; 339 __u32 __pad; /* force sctp_cookie alignment to 64 bits */ 340 struct sctp_cookie c; 341 } __packed; 342 343 /* This is another convenience type to allocate memory for address 344 * params for the maximum size and pass such structures around 345 * internally. 346 */ 347 union sctp_addr_param { 348 struct sctp_paramhdr p; 349 struct sctp_ipv4addr_param v4; 350 struct sctp_ipv6addr_param v6; 351 }; 352 353 /* A convenience type to allow walking through the various 354 * parameters and avoid casting all over the place. 355 */ 356 union sctp_params { 357 void *v; 358 struct sctp_paramhdr *p; 359 struct sctp_cookie_preserve_param *life; 360 struct sctp_hostname_param *dns; 361 struct sctp_cookie_param *cookie; 362 struct sctp_supported_addrs_param *sat; 363 struct sctp_ipv4addr_param *v4; 364 struct sctp_ipv6addr_param *v6; 365 union sctp_addr_param *addr; 366 struct sctp_adaptation_ind_param *aind; 367 struct sctp_supported_ext_param *ext; 368 struct sctp_random_param *random; 369 struct sctp_chunks_param *chunks; 370 struct sctp_hmac_algo_param *hmac_algo; 371 struct sctp_addip_param *addip; 372 }; 373 374 /* RFC 2960. Section 3.3.5 Heartbeat. 375 * Heartbeat Information: variable length 376 * The Sender-specific Heartbeat Info field should normally include 377 * information about the sender's current time when this HEARTBEAT 378 * chunk is sent and the destination transport address to which this 379 * HEARTBEAT is sent (see Section 8.3). 380 */ 381 struct sctp_sender_hb_info { 382 struct sctp_paramhdr param_hdr; 383 union sctp_addr daddr; 384 unsigned long sent_at; 385 __u64 hb_nonce; 386 __u32 probe_size; 387 }; 388 389 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt, 390 gfp_t gfp); 391 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid); 392 void sctp_stream_free(struct sctp_stream *stream); 393 void sctp_stream_clear(struct sctp_stream *stream); 394 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new); 395 396 /* What is the current SSN number for this stream? */ 397 #define sctp_ssn_peek(stream, type, sid) \ 398 (sctp_stream_##type((stream), (sid))->ssn) 399 400 /* Return the next SSN number for this stream. */ 401 #define sctp_ssn_next(stream, type, sid) \ 402 (sctp_stream_##type((stream), (sid))->ssn++) 403 404 /* Skip over this ssn and all below. */ 405 #define sctp_ssn_skip(stream, type, sid, ssn) \ 406 (sctp_stream_##type((stream), (sid))->ssn = ssn + 1) 407 408 /* What is the current MID number for this stream? */ 409 #define sctp_mid_peek(stream, type, sid) \ 410 (sctp_stream_##type((stream), (sid))->mid) 411 412 /* Return the next MID number for this stream. */ 413 #define sctp_mid_next(stream, type, sid) \ 414 (sctp_stream_##type((stream), (sid))->mid++) 415 416 /* Skip over this mid and all below. */ 417 #define sctp_mid_skip(stream, type, sid, mid) \ 418 (sctp_stream_##type((stream), (sid))->mid = mid + 1) 419 420 /* What is the current MID_uo number for this stream? */ 421 #define sctp_mid_uo_peek(stream, type, sid) \ 422 (sctp_stream_##type((stream), (sid))->mid_uo) 423 424 /* Return the next MID_uo number for this stream. */ 425 #define sctp_mid_uo_next(stream, type, sid) \ 426 (sctp_stream_##type((stream), (sid))->mid_uo++) 427 428 /* 429 * Pointers to address related SCTP functions. 430 * (i.e. things that depend on the address family.) 431 */ 432 struct 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 sockptr_t 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 void (*get_dst) (struct sctp_transport *t, 446 union sctp_addr *saddr, 447 struct flowi *fl, 448 struct sock *sk); 449 void (*get_saddr) (struct sctp_sock *sk, 450 struct sctp_transport *t, 451 struct flowi *fl); 452 void (*copy_addrlist) (struct list_head *, 453 struct net_device *); 454 int (*cmp_addr) (const union sctp_addr *addr1, 455 const union sctp_addr *addr2); 456 void (*addr_copy) (union sctp_addr *dst, 457 union sctp_addr *src); 458 void (*from_skb) (union sctp_addr *, 459 struct sk_buff *skb, 460 int saddr); 461 void (*from_sk) (union sctp_addr *, 462 struct sock *sk); 463 bool (*from_addr_param) (union sctp_addr *, 464 union sctp_addr_param *, 465 __be16 port, int iif); 466 int (*to_addr_param) (const union sctp_addr *, 467 union sctp_addr_param *); 468 int (*addr_valid) (union sctp_addr *, 469 struct sctp_sock *, 470 const struct sk_buff *); 471 enum sctp_scope (*scope)(union sctp_addr *); 472 void (*inaddr_any) (union sctp_addr *, __be16); 473 int (*is_any) (const union sctp_addr *); 474 int (*available) (union sctp_addr *, 475 struct sctp_sock *); 476 int (*skb_iif) (const struct sk_buff *sk); 477 int (*skb_sdif)(const struct sk_buff *sk); 478 int (*is_ce) (const struct sk_buff *sk); 479 void (*seq_dump_addr)(struct seq_file *seq, 480 union sctp_addr *addr); 481 void (*ecn_capable)(struct sock *sk); 482 __u16 net_header_len; 483 int sockaddr_len; 484 int (*ip_options_len)(struct sock *sk); 485 sa_family_t sa_family; 486 struct list_head list; 487 }; 488 489 struct sctp_af *sctp_get_af_specific(sa_family_t); 490 int sctp_register_af(struct sctp_af *); 491 492 /* Protocol family functions. */ 493 struct sctp_pf { 494 void (*event_msgname)(struct sctp_ulpevent *, char *, int *); 495 void (*skb_msgname) (struct sk_buff *, char *, int *); 496 int (*af_supported) (sa_family_t, struct sctp_sock *); 497 int (*cmp_addr) (const union sctp_addr *, 498 const union sctp_addr *, 499 struct sctp_sock *); 500 int (*bind_verify) (struct sctp_sock *, union sctp_addr *); 501 int (*send_verify) (struct sctp_sock *, union sctp_addr *); 502 int (*supported_addrs)(const struct sctp_sock *, __be16 *); 503 struct sock *(*create_accept_sk) (struct sock *sk, 504 struct sctp_association *asoc, 505 bool kern); 506 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr); 507 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk); 508 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk); 509 void (*copy_ip_options)(struct sock *sk, struct sock *newsk); 510 struct sctp_af *af; 511 }; 512 513 514 /* Structure to track chunk fragments that have been acked, but peer 515 * fragments of the same message have not. 516 */ 517 struct sctp_datamsg { 518 /* Chunks waiting to be submitted to lower layer. */ 519 struct list_head chunks; 520 /* Reference counting. */ 521 refcount_t refcnt; 522 /* When is this message no longer interesting to the peer? */ 523 unsigned long expires_at; 524 /* Did the message fail to send? */ 525 int send_error; 526 u8 send_failed:1, 527 can_delay:1, /* should this message be Nagle delayed */ 528 abandoned:1; /* should this message be abandoned */ 529 }; 530 531 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, 532 struct sctp_sndrcvinfo *, 533 struct iov_iter *); 534 void sctp_datamsg_free(struct sctp_datamsg *); 535 void sctp_datamsg_put(struct sctp_datamsg *); 536 void sctp_chunk_fail(struct sctp_chunk *, int error); 537 int sctp_chunk_abandoned(struct sctp_chunk *); 538 539 /* RFC2960 1.4 Key Terms 540 * 541 * o Chunk: A unit of information within an SCTP packet, consisting of 542 * a chunk header and chunk-specific content. 543 * 544 * As a matter of convenience, we remember the SCTP common header for 545 * each chunk as well as a few other header pointers... 546 */ 547 struct sctp_chunk { 548 struct list_head list; 549 550 refcount_t refcnt; 551 552 /* How many times this chunk have been sent, for prsctp RTX policy */ 553 int sent_count; 554 555 union { 556 /* This is our link to the per-transport transmitted list. */ 557 struct list_head transmitted_list; 558 /* List in specific stream outq */ 559 struct list_head stream_list; 560 }; 561 562 /* This field is used by chunks that hold fragmented data. 563 * For the first fragment this is the list that holds the rest of 564 * fragments. For the remaining fragments, this is the link to the 565 * frag_list maintained in the first fragment. 566 */ 567 struct list_head frag_list; 568 569 /* This points to the sk_buff containing the actual data. */ 570 struct sk_buff *skb; 571 572 union { 573 /* In case of GSO packets, this will store the head one */ 574 struct sk_buff *head_skb; 575 /* In case of auth enabled, this will point to the shkey */ 576 struct sctp_shared_key *shkey; 577 }; 578 579 /* These are the SCTP headers by reverse order in a packet. 580 * Note that some of these may happen more than once. In that 581 * case, we point at the "current" one, whatever that means 582 * for that level of header. 583 */ 584 585 /* We point this at the FIRST TLV parameter to chunk_hdr. */ 586 union sctp_params param_hdr; 587 union { 588 __u8 *v; 589 struct sctp_datahdr *data_hdr; 590 struct sctp_inithdr *init_hdr; 591 struct sctp_sackhdr *sack_hdr; 592 struct sctp_heartbeathdr *hb_hdr; 593 struct sctp_sender_hb_info *hbs_hdr; 594 struct sctp_shutdownhdr *shutdown_hdr; 595 struct sctp_signed_cookie *cookie_hdr; 596 struct sctp_ecnehdr *ecne_hdr; 597 struct sctp_cwrhdr *ecn_cwr_hdr; 598 struct sctp_errhdr *err_hdr; 599 struct sctp_addiphdr *addip_hdr; 600 struct sctp_fwdtsn_hdr *fwdtsn_hdr; 601 struct sctp_authhdr *auth_hdr; 602 struct sctp_idatahdr *idata_hdr; 603 struct sctp_ifwdtsn_hdr *ifwdtsn_hdr; 604 } subh; 605 606 __u8 *chunk_end; 607 608 struct sctp_chunkhdr *chunk_hdr; 609 struct sctphdr *sctp_hdr; 610 611 /* This needs to be recoverable for SCTP_SEND_FAILED events. */ 612 struct sctp_sndrcvinfo sinfo; 613 614 /* Which association does this belong to? */ 615 struct sctp_association *asoc; 616 617 /* What endpoint received this chunk? */ 618 struct sctp_ep_common *rcvr; 619 620 /* We fill this in if we are calculating RTT. */ 621 unsigned long sent_at; 622 623 /* What is the origin IP address for this chunk? */ 624 union sctp_addr source; 625 /* Destination address for this chunk. */ 626 union sctp_addr dest; 627 628 /* For outbound message, track all fragments for SEND_FAILED. */ 629 struct sctp_datamsg *msg; 630 631 /* For an inbound chunk, this tells us where it came from. 632 * For an outbound chunk, it tells us where we'd like it to 633 * go. It is NULL if we have no preference. 634 */ 635 struct sctp_transport *transport; 636 637 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO 638 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH 639 * spec violates the principle premis that all chunks are processed 640 * in order. 641 */ 642 struct sk_buff *auth_chunk; 643 644 #define SCTP_CAN_FRTX 0x0 645 #define SCTP_NEED_FRTX 0x1 646 #define SCTP_DONT_FRTX 0x2 647 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */ 648 has_tsn:1, /* Does this chunk have a TSN yet? */ 649 has_ssn:1, /* Does this chunk have a SSN yet? */ 650 #define has_mid has_ssn 651 singleton:1, /* Only chunk in the packet? */ 652 end_of_packet:1, /* Last chunk in the packet? */ 653 ecn_ce_done:1, /* Have we processed the ECN CE bit? */ 654 pdiscard:1, /* Discard the whole packet now? */ 655 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */ 656 data_accepted:1, /* At least 1 chunk accepted */ 657 auth:1, /* IN: was auth'ed | OUT: needs auth */ 658 has_asconf:1, /* IN: have seen an asconf before */ 659 pmtu_probe:1, /* Used by PLPMTUD, can be set in s HB chunk */ 660 tsn_missing_report:2, /* Data chunk missing counter. */ 661 fast_retransmit:2; /* Is this chunk fast retransmitted? */ 662 }; 663 664 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1) 665 void sctp_chunk_hold(struct sctp_chunk *); 666 void sctp_chunk_put(struct sctp_chunk *); 667 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 668 struct iov_iter *from); 669 void sctp_chunk_free(struct sctp_chunk *); 670 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); 671 struct sctp_chunk *sctp_chunkify(struct sk_buff *, 672 const struct sctp_association *, 673 struct sock *, gfp_t gfp); 674 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, 675 union sctp_addr *); 676 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); 677 sctp_chunk_stream_no(struct sctp_chunk * ch)678 static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch) 679 { 680 return ntohs(ch->subh.data_hdr->stream); 681 } 682 683 enum { 684 SCTP_ADDR_NEW, /* new address added to assoc/ep */ 685 SCTP_ADDR_SRC, /* address can be used as source */ 686 SCTP_ADDR_DEL, /* address about to be deleted */ 687 }; 688 689 /* This is a structure for holding either an IPv6 or an IPv4 address. */ 690 struct sctp_sockaddr_entry { 691 struct list_head list; 692 struct rcu_head rcu; 693 union sctp_addr a; 694 __u8 state; 695 __u8 valid; 696 }; 697 698 #define SCTP_ADDRESS_TICK_DELAY 500 699 700 /* This structure holds lists of chunks as we are assembling for 701 * transmission. 702 */ 703 struct sctp_packet { 704 /* These are the SCTP header values (host order) for the packet. */ 705 __u16 source_port; 706 __u16 destination_port; 707 __u32 vtag; 708 709 /* This contains the payload chunks. */ 710 struct list_head chunk_list; 711 712 /* This is the overhead of the sctp and ip headers. */ 713 size_t overhead; 714 /* This is the total size of all chunks INCLUDING padding. */ 715 size_t size; 716 /* This is the maximum size this packet may have */ 717 size_t max_size; 718 719 /* The packet is destined for this transport address. 720 * The function we finally use to pass down to the next lower 721 * layer lives in the transport structure. 722 */ 723 struct sctp_transport *transport; 724 725 /* pointer to the auth chunk for this packet */ 726 struct sctp_chunk *auth; 727 728 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */ 729 has_sack:1, /* This packet contains a SACK chunk. */ 730 has_auth:1, /* This packet contains an AUTH chunk */ 731 has_data:1, /* This packet contains at least 1 DATA chunk */ 732 ipfragok:1; /* So let ip fragment this packet */ 733 }; 734 735 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *, 736 __u16 sport, __u16 dport); 737 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int); 738 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet, 739 struct sctp_chunk *chunk, 740 int one_packet, gfp_t gfp); 741 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet, 742 struct sctp_chunk *chunk); 743 int sctp_packet_transmit(struct sctp_packet *, gfp_t); 744 void sctp_packet_free(struct sctp_packet *); 745 sctp_packet_empty(struct sctp_packet * packet)746 static inline int sctp_packet_empty(struct sctp_packet *packet) 747 { 748 return packet->size == packet->overhead; 749 } 750 751 /* This represents a remote transport address. 752 * For local transport addresses, we just use union sctp_addr. 753 * 754 * RFC2960 Section 1.4 Key Terms 755 * 756 * o Transport address: A Transport Address is traditionally defined 757 * by Network Layer address, Transport Layer protocol and Transport 758 * Layer port number. In the case of SCTP running over IP, a 759 * transport address is defined by the combination of an IP address 760 * and an SCTP port number (where SCTP is the Transport protocol). 761 * 762 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control 763 * 764 * o The sender keeps a separate congestion control parameter set for 765 * each of the destination addresses it can send to (not each 766 * source-destination pair but for each destination). The parameters 767 * should decay if the address is not used for a long enough time 768 * period. 769 * 770 */ 771 struct sctp_transport { 772 /* A list of transports. */ 773 struct list_head transports; 774 struct rhlist_head node; 775 776 /* Reference counting. */ 777 refcount_t refcnt; 778 /* RTO-Pending : A flag used to track if one of the DATA 779 * chunks sent to this address is currently being 780 * used to compute a RTT. If this flag is 0, 781 * the next DATA chunk sent to this destination 782 * should be used to compute a RTT and this flag 783 * should be set. Every time the RTT 784 * calculation completes (i.e. the DATA chunk 785 * is SACK'd) clear this flag. 786 */ 787 __u32 rto_pending:1, 788 789 /* 790 * hb_sent : a flag that signals that we have a pending 791 * heartbeat. 792 */ 793 hb_sent:1, 794 795 /* Is the Path MTU update pending on this transport */ 796 pmtu_pending:1, 797 798 dst_pending_confirm:1, /* need to confirm neighbour */ 799 800 /* Has this transport moved the ctsn since we last sacked */ 801 sack_generation:1; 802 u32 dst_cookie; 803 804 struct flowi fl; 805 806 /* This is the peer's IP address and port. */ 807 union sctp_addr ipaddr; 808 809 /* These are the functions we call to handle LLP stuff. */ 810 struct sctp_af *af_specific; 811 812 /* Which association do we belong to? */ 813 struct sctp_association *asoc; 814 815 /* RFC2960 816 * 817 * 12.3 Per Transport Address Data 818 * 819 * For each destination transport address in the peer's 820 * address list derived from the INIT or INIT ACK chunk, a 821 * number of data elements needs to be maintained including: 822 */ 823 /* RTO : The current retransmission timeout value. */ 824 unsigned long rto; 825 826 __u32 rtt; /* This is the most recent RTT. */ 827 828 /* RTTVAR : The current RTT variation. */ 829 __u32 rttvar; 830 831 /* SRTT : The current smoothed round trip time. */ 832 __u32 srtt; 833 834 /* 835 * These are the congestion stats. 836 */ 837 /* cwnd : The current congestion window. */ 838 __u32 cwnd; /* This is the actual cwnd. */ 839 840 /* ssthresh : The current slow start threshold value. */ 841 __u32 ssthresh; 842 843 /* partial : The tracking method for increase of cwnd when in 844 * bytes acked : congestion avoidance mode (see Section 6.2.2) 845 */ 846 __u32 partial_bytes_acked; 847 848 /* Data that has been sent, but not acknowledged. */ 849 __u32 flight_size; 850 851 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */ 852 853 /* Destination */ 854 struct dst_entry *dst; 855 /* Source address. */ 856 union sctp_addr saddr; 857 858 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 859 * the destination address every heartbeat interval. 860 */ 861 unsigned long hbinterval; 862 unsigned long probe_interval; 863 864 /* SACK delay timeout */ 865 unsigned long sackdelay; 866 __u32 sackfreq; 867 868 atomic_t mtu_info; 869 870 /* When was the last time that we heard from this transport? We use 871 * this to pick new active and retran paths. 872 */ 873 ktime_t last_time_heard; 874 875 /* When was the last time that we sent a chunk using this 876 * transport? We use this to check for idle transports 877 */ 878 unsigned long last_time_sent; 879 880 /* Last time(in jiffies) when cwnd is reduced due to the congestion 881 * indication based on ECNE chunk. 882 */ 883 unsigned long last_time_ecne_reduced; 884 885 __be16 encap_port; 886 887 /* This is the max_retrans value for the transport and will 888 * be initialized from the assocs value. This can be changed 889 * using the SCTP_SET_PEER_ADDR_PARAMS socket option. 890 */ 891 __u16 pathmaxrxt; 892 893 __u32 flowlabel; 894 __u8 dscp; 895 896 /* This is the partially failed retrans value for the transport 897 * and will be initialized from the assocs value. This can be changed 898 * using the SCTP_PEER_ADDR_THLDS socket option 899 */ 900 __u16 pf_retrans; 901 /* Used for primary path switchover. */ 902 __u16 ps_retrans; 903 /* PMTU : The current known path MTU. */ 904 __u32 pathmtu; 905 906 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ 907 __u32 param_flags; 908 909 /* The number of times INIT has been sent on this transport. */ 910 int init_sent_count; 911 912 /* state : The current state of this destination, 913 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN. 914 */ 915 int state; 916 917 /* These are the error stats for this destination. */ 918 919 /* Error count : The current error count for this destination. */ 920 unsigned short error_count; 921 922 /* Per : A timer used by each destination. 923 * Destination : 924 * Timer : 925 * 926 * [Everywhere else in the text this is called T3-rtx. -ed] 927 */ 928 struct timer_list T3_rtx_timer; 929 930 /* Heartbeat timer is per destination. */ 931 struct timer_list hb_timer; 932 933 /* Timer to handle ICMP proto unreachable envets */ 934 struct timer_list proto_unreach_timer; 935 936 /* Timer to handler reconf chunk rtx */ 937 struct timer_list reconf_timer; 938 939 /* Timer to send a probe HB packet for PLPMTUD */ 940 struct timer_list probe_timer; 941 942 /* Since we're using per-destination retransmission timers 943 * (see above), we're also using per-destination "transmitted" 944 * queues. This probably ought to be a private struct 945 * accessible only within the outqueue, but it's not, yet. 946 */ 947 struct list_head transmitted; 948 949 /* We build bundle-able packets for this transport here. */ 950 struct sctp_packet packet; 951 952 /* This is the list of transports that have chunks to send. */ 953 struct list_head send_ready; 954 955 /* State information saved for SFR_CACC algorithm. The key 956 * idea in SFR_CACC is to maintain state at the sender on a 957 * per-destination basis when a changeover happens. 958 * char changeover_active; 959 * char cycling_changeover; 960 * __u32 next_tsn_at_change; 961 * char cacc_saw_newack; 962 */ 963 struct { 964 /* An unsigned integer, which stores the next TSN to be 965 * used by the sender, at the moment of changeover. 966 */ 967 __u32 next_tsn_at_change; 968 969 /* A flag which indicates the occurrence of a changeover */ 970 char changeover_active; 971 972 /* A flag which indicates whether the change of primary is 973 * the first switch to this destination address during an 974 * active switch. 975 */ 976 char cycling_changeover; 977 978 /* A temporary flag, which is used during the processing of 979 * a SACK to estimate the causative TSN(s)'s group. 980 */ 981 char cacc_saw_newack; 982 } cacc; 983 984 struct { 985 __u16 pmtu; 986 __u16 probe_size; 987 __u16 probe_high; 988 __u8 probe_count; 989 __u8 state; 990 } pl; /* plpmtud related */ 991 992 /* 64-bit random number sent with heartbeat. */ 993 __u64 hb_nonce; 994 995 struct rcu_head rcu; 996 }; 997 998 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *, 999 gfp_t); 1000 void sctp_transport_set_owner(struct sctp_transport *, 1001 struct sctp_association *); 1002 void sctp_transport_route(struct sctp_transport *, union sctp_addr *, 1003 struct sctp_sock *); 1004 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk); 1005 void sctp_transport_free(struct sctp_transport *); 1006 void sctp_transport_reset_t3_rtx(struct sctp_transport *); 1007 void sctp_transport_reset_hb_timer(struct sctp_transport *); 1008 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport); 1009 void sctp_transport_reset_probe_timer(struct sctp_transport *transport); 1010 void sctp_transport_reset_raise_timer(struct sctp_transport *transport); 1011 int sctp_transport_hold(struct sctp_transport *); 1012 void sctp_transport_put(struct sctp_transport *); 1013 void sctp_transport_update_rto(struct sctp_transport *, __u32); 1014 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32); 1015 void sctp_transport_lower_cwnd(struct sctp_transport *t, 1016 enum sctp_lower_cwnd reason); 1017 void sctp_transport_burst_limited(struct sctp_transport *); 1018 void sctp_transport_burst_reset(struct sctp_transport *); 1019 unsigned long sctp_transport_timeout(struct sctp_transport *); 1020 void sctp_transport_reset(struct sctp_transport *t); 1021 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu); 1022 void sctp_transport_immediate_rtx(struct sctp_transport *); 1023 void sctp_transport_dst_release(struct sctp_transport *t); 1024 void sctp_transport_dst_confirm(struct sctp_transport *t); 1025 void sctp_transport_pl_send(struct sctp_transport *t); 1026 bool sctp_transport_pl_recv(struct sctp_transport *t); 1027 1028 1029 /* This is the structure we use to queue packets as they come into 1030 * SCTP. We write packets to it and read chunks from it. 1031 */ 1032 struct sctp_inq { 1033 /* This is actually a queue of sctp_chunk each 1034 * containing a partially decoded packet. 1035 */ 1036 struct list_head in_chunk_list; 1037 /* This is the packet which is currently off the in queue and is 1038 * being worked on through the inbound chunk processing. 1039 */ 1040 struct sctp_chunk *in_progress; 1041 1042 /* This is the delayed task to finish delivering inbound 1043 * messages. 1044 */ 1045 struct work_struct immediate; 1046 }; 1047 1048 void sctp_inq_init(struct sctp_inq *); 1049 void sctp_inq_free(struct sctp_inq *); 1050 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet); 1051 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *); 1052 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *); 1053 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t); 1054 1055 /* This is the structure we use to hold outbound chunks. You push 1056 * chunks in and they automatically pop out the other end as bundled 1057 * packets (it calls (*output_handler)()). 1058 * 1059 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1, 1060 * and 8.2 of the v13 draft. 1061 * 1062 * It handles retransmissions. The connection to the timeout portion 1063 * of the state machine is through sctp_..._timeout() and timeout_handler. 1064 * 1065 * If you feed it SACKs, it will eat them. 1066 * 1067 * If you give it big chunks, it will fragment them. 1068 * 1069 * It assigns TSN's to data chunks. This happens at the last possible 1070 * instant before transmission. 1071 * 1072 * When free()'d, it empties itself out via output_handler(). 1073 */ 1074 struct sctp_outq { 1075 struct sctp_association *asoc; 1076 1077 /* Data pending that has never been transmitted. */ 1078 struct list_head out_chunk_list; 1079 1080 /* Stream scheduler being used */ 1081 struct sctp_sched_ops *sched; 1082 1083 unsigned int out_qlen; /* Total length of queued data chunks. */ 1084 1085 /* Error of send failed, may used in SCTP_SEND_FAILED event. */ 1086 unsigned int error; 1087 1088 /* These are control chunks we want to send. */ 1089 struct list_head control_chunk_list; 1090 1091 /* These are chunks that have been sacked but are above the 1092 * CTSN, or cumulative tsn ack point. 1093 */ 1094 struct list_head sacked; 1095 1096 /* Put chunks on this list to schedule them for 1097 * retransmission. 1098 */ 1099 struct list_head retransmit; 1100 1101 /* Put chunks on this list to save them for FWD TSN processing as 1102 * they were abandoned. 1103 */ 1104 struct list_head abandoned; 1105 1106 /* How many unackd bytes do we have in-flight? */ 1107 __u32 outstanding_bytes; 1108 1109 /* Are we doing fast-rtx on this queue */ 1110 char fast_rtx; 1111 1112 /* Corked? */ 1113 char cork; 1114 }; 1115 1116 void sctp_outq_init(struct sctp_association *, struct sctp_outq *); 1117 void sctp_outq_teardown(struct sctp_outq *); 1118 void sctp_outq_free(struct sctp_outq*); 1119 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t); 1120 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *); 1121 int sctp_outq_is_empty(const struct sctp_outq *); 1122 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, 1123 enum sctp_retransmit_reason reason); 1124 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); 1125 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp); 1126 void sctp_prsctp_prune(struct sctp_association *asoc, 1127 struct sctp_sndrcvinfo *sinfo, int msg_len); 1128 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn); 1129 /* Uncork and flush an outqueue. */ sctp_outq_cork(struct sctp_outq * q)1130 static inline void sctp_outq_cork(struct sctp_outq *q) 1131 { 1132 q->cork = 1; 1133 } 1134 1135 /* SCTP skb control block. 1136 * sctp_input_cb is currently used on rx and sock rx queue 1137 */ 1138 struct sctp_input_cb { 1139 union { 1140 struct inet_skb_parm h4; 1141 #if IS_ENABLED(CONFIG_IPV6) 1142 struct inet6_skb_parm h6; 1143 #endif 1144 } header; 1145 struct sctp_chunk *chunk; 1146 struct sctp_af *af; 1147 __be16 encap_port; 1148 }; 1149 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0])) 1150 1151 struct sctp_output_cb { 1152 struct sk_buff *last; 1153 }; 1154 #define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0])) 1155 sctp_gso_headskb(const struct sk_buff * skb)1156 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb) 1157 { 1158 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; 1159 1160 return chunk->head_skb ? : skb; 1161 } 1162 1163 /* These bind address data fields common between endpoints and associations */ 1164 struct sctp_bind_addr { 1165 1166 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1167 * 1168 * SCTP Port: The local SCTP port number the endpoint is 1169 * bound to. 1170 */ 1171 __u16 port; 1172 1173 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1174 * 1175 * Address List: The list of IP addresses that this instance 1176 * has bound. This information is passed to one's 1177 * peer(s) in INIT and INIT ACK chunks. 1178 */ 1179 struct list_head address_list; 1180 }; 1181 1182 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port); 1183 void sctp_bind_addr_free(struct sctp_bind_addr *); 1184 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest, 1185 const struct sctp_bind_addr *src, 1186 enum sctp_scope scope, gfp_t gfp, 1187 int flags); 1188 int sctp_bind_addr_dup(struct sctp_bind_addr *dest, 1189 const struct sctp_bind_addr *src, 1190 gfp_t gfp); 1191 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1192 int new_size, __u8 addr_state, gfp_t gfp); 1193 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *); 1194 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, 1195 struct sctp_sock *); 1196 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *, 1197 struct sctp_sock *, struct sctp_sock *); 1198 int sctp_bind_addr_state(const struct sctp_bind_addr *bp, 1199 const union sctp_addr *addr); 1200 int sctp_bind_addrs_check(struct sctp_sock *sp, 1201 struct sctp_sock *sp2, int cnt2); 1202 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 1203 const union sctp_addr *addrs, 1204 int addrcnt, 1205 struct sctp_sock *opt); 1206 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 1207 int *addrs_len, 1208 gfp_t gfp); 1209 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, 1210 __u16 port, gfp_t gfp); 1211 1212 enum sctp_scope sctp_scope(const union sctp_addr *addr); 1213 int sctp_in_scope(struct net *net, const union sctp_addr *addr, 1214 const enum sctp_scope scope); 1215 int sctp_is_any(struct sock *sk, const union sctp_addr *addr); 1216 int sctp_is_ep_boundall(struct sock *sk); 1217 1218 1219 /* What type of endpoint? */ 1220 enum sctp_endpoint_type { 1221 SCTP_EP_TYPE_SOCKET, 1222 SCTP_EP_TYPE_ASSOCIATION, 1223 }; 1224 1225 /* 1226 * A common base class to bridge the implementation view of a 1227 * socket (usually listening) endpoint versus an association's 1228 * local endpoint. 1229 * This common structure is useful for several purposes: 1230 * 1) Common interface for lookup routines. 1231 * a) Subfunctions work for either endpoint or association 1232 * b) Single interface to lookup allows hiding the lookup lock rather 1233 * than acquiring it externally. 1234 * 2) Common interface for the inbound chunk handling/state machine. 1235 * 3) Common object handling routines for reference counting, etc. 1236 * 4) Disentangle association lookup from endpoint lookup, where we 1237 * do not have to find our endpoint to find our association. 1238 * 1239 */ 1240 1241 struct sctp_ep_common { 1242 /* Runtime type information. What kind of endpoint is this? */ 1243 enum sctp_endpoint_type type; 1244 1245 /* Some fields to help us manage this object. 1246 * refcnt - Reference count access to this object. 1247 * dead - Do not attempt to use this object. 1248 */ 1249 refcount_t refcnt; 1250 bool dead; 1251 1252 /* What socket does this endpoint belong to? */ 1253 struct sock *sk; 1254 1255 /* Cache netns and it won't change once set */ 1256 struct net *net; 1257 1258 /* This is where we receive inbound chunks. */ 1259 struct sctp_inq inqueue; 1260 1261 /* This substructure includes the defining parameters of the 1262 * endpoint: 1263 * bind_addr.port is our shared port number. 1264 * bind_addr.address_list is our set of local IP addresses. 1265 */ 1266 struct sctp_bind_addr bind_addr; 1267 }; 1268 1269 1270 /* RFC Section 1.4 Key Terms 1271 * 1272 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a 1273 * multi-homed host, an SCTP endpoint is represented to its peers as a 1274 * combination of a set of eligible destination transport addresses to 1275 * which SCTP packets can be sent and a set of eligible source 1276 * transport addresses from which SCTP packets can be received. 1277 * All transport addresses used by an SCTP endpoint must use the 1278 * same port number, but can use multiple IP addresses. A transport 1279 * address used by an SCTP endpoint must not be used by another 1280 * SCTP endpoint. In other words, a transport address is unique 1281 * to an SCTP endpoint. 1282 * 1283 * From an implementation perspective, each socket has one of these. 1284 * A TCP-style socket will have exactly one association on one of 1285 * these. An UDP-style socket will have multiple associations hanging 1286 * off one of these. 1287 */ 1288 1289 struct sctp_endpoint { 1290 /* Common substructure for endpoint and association. */ 1291 struct sctp_ep_common base; 1292 1293 /* Fields to help us manage our entries in the hash tables. */ 1294 struct hlist_node node; 1295 int hashent; 1296 1297 /* Associations: A list of current associations and mappings 1298 * to the data consumers for each association. This 1299 * may be in the form of a hash table or other 1300 * implementation dependent structure. The data 1301 * consumers may be process identification 1302 * information such as file descriptors, named pipe 1303 * pointer, or table pointers dependent on how SCTP 1304 * is implemented. 1305 */ 1306 /* This is really a list of struct sctp_association entries. */ 1307 struct list_head asocs; 1308 1309 /* Secret Key: A secret key used by this endpoint to compute 1310 * the MAC. This SHOULD be a cryptographic quality 1311 * random number with a sufficient length. 1312 * Discussion in [RFC1750] can be helpful in 1313 * selection of the key. 1314 */ 1315 __u8 secret_key[SCTP_SECRET_SIZE]; 1316 1317 /* digest: This is a digest of the sctp cookie. This field is 1318 * only used on the receive path when we try to validate 1319 * that the cookie has not been tampered with. We put 1320 * this here so we pre-allocate this once and can re-use 1321 * on every receive. 1322 */ 1323 __u8 *digest; 1324 1325 /* sendbuf acct. policy. */ 1326 __u32 sndbuf_policy; 1327 1328 /* rcvbuf acct. policy. */ 1329 __u32 rcvbuf_policy; 1330 1331 /* SCTP AUTH: array of the HMACs that will be allocated 1332 * we need this per association so that we don't serialize 1333 */ 1334 struct crypto_shash **auth_hmacs; 1335 1336 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */ 1337 struct sctp_hmac_algo_param *auth_hmacs_list; 1338 1339 /* SCTP-AUTH: chunks to authenticate encoded into parameter */ 1340 struct sctp_chunks_param *auth_chunk_list; 1341 1342 /* SCTP-AUTH: endpoint shared keys */ 1343 struct list_head endpoint_shared_keys; 1344 __u16 active_key_id; 1345 __u8 ecn_enable:1, 1346 auth_enable:1, 1347 intl_enable:1, 1348 prsctp_enable:1, 1349 asconf_enable:1, 1350 reconf_enable:1; 1351 1352 __u8 strreset_enable; 1353 struct rcu_head rcu; 1354 }; 1355 1356 /* Recover the outer endpoint structure. */ sctp_ep(struct sctp_ep_common * base)1357 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) 1358 { 1359 struct sctp_endpoint *ep; 1360 1361 ep = container_of(base, struct sctp_endpoint, base); 1362 return ep; 1363 } 1364 1365 /* These are function signatures for manipulating endpoints. */ 1366 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t); 1367 void sctp_endpoint_free(struct sctp_endpoint *); 1368 void sctp_endpoint_put(struct sctp_endpoint *); 1369 int sctp_endpoint_hold(struct sctp_endpoint *ep); 1370 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); 1371 struct sctp_association *sctp_endpoint_lookup_assoc( 1372 const struct sctp_endpoint *ep, 1373 const union sctp_addr *paddr, 1374 struct sctp_transport **); 1375 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep, 1376 const union sctp_addr *paddr); 1377 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep, 1378 struct net *net, 1379 const union sctp_addr *laddr, 1380 int dif, int sdif); 1381 bool sctp_has_association(struct net *net, const union sctp_addr *laddr, 1382 const union sctp_addr *paddr, int dif, int sdif); 1383 1384 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 1385 const struct sctp_association *asoc, 1386 enum sctp_cid cid, struct sctp_init_chunk *peer_init, 1387 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk); 1388 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk, 1389 const union sctp_addr *peer, 1390 struct sctp_init_chunk *init, gfp_t gfp); 1391 __u32 sctp_generate_tag(const struct sctp_endpoint *); 1392 __u32 sctp_generate_tsn(const struct sctp_endpoint *); 1393 1394 struct sctp_inithdr_host { 1395 __u32 init_tag; 1396 __u32 a_rwnd; 1397 __u16 num_outbound_streams; 1398 __u16 num_inbound_streams; 1399 __u32 initial_tsn; 1400 }; 1401 1402 struct sctp_stream_priorities { 1403 /* List of priorities scheduled */ 1404 struct list_head prio_sched; 1405 /* List of streams scheduled */ 1406 struct list_head active; 1407 /* The next stream in line */ 1408 struct sctp_stream_out_ext *next; 1409 __u16 prio; 1410 __u16 users; 1411 }; 1412 1413 struct sctp_stream_out_ext { 1414 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1]; 1415 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1]; 1416 struct list_head outq; /* chunks enqueued by this stream */ 1417 union { 1418 struct { 1419 /* Scheduled streams list */ 1420 struct list_head prio_list; 1421 struct sctp_stream_priorities *prio_head; 1422 }; 1423 /* Fields used by RR scheduler */ 1424 struct { 1425 struct list_head rr_list; 1426 }; 1427 struct { 1428 struct list_head fc_list; 1429 __u32 fc_length; 1430 __u16 fc_weight; 1431 }; 1432 }; 1433 }; 1434 1435 struct sctp_stream_out { 1436 union { 1437 __u32 mid; 1438 __u16 ssn; 1439 }; 1440 __u32 mid_uo; 1441 struct sctp_stream_out_ext *ext; 1442 __u8 state; 1443 }; 1444 1445 struct sctp_stream_in { 1446 union { 1447 __u32 mid; 1448 __u16 ssn; 1449 }; 1450 __u32 mid_uo; 1451 __u32 fsn; 1452 __u32 fsn_uo; 1453 char pd_mode; 1454 char pd_mode_uo; 1455 }; 1456 1457 struct sctp_stream { 1458 GENRADIX(struct sctp_stream_out) out; 1459 GENRADIX(struct sctp_stream_in) in; 1460 1461 __u16 outcnt; 1462 __u16 incnt; 1463 /* Current stream being sent, if any */ 1464 struct sctp_stream_out *out_curr; 1465 union { 1466 /* Fields used by priority scheduler */ 1467 struct { 1468 /* List of priorities scheduled */ 1469 struct list_head prio_list; 1470 }; 1471 /* Fields used by RR scheduler */ 1472 struct { 1473 /* List of streams scheduled */ 1474 struct list_head rr_list; 1475 /* The next stream in line */ 1476 struct sctp_stream_out_ext *rr_next; 1477 }; 1478 struct { 1479 struct list_head fc_list; 1480 }; 1481 }; 1482 struct sctp_stream_interleave *si; 1483 }; 1484 sctp_stream_out(struct sctp_stream * stream,__u16 sid)1485 static inline struct sctp_stream_out *sctp_stream_out( 1486 struct sctp_stream *stream, 1487 __u16 sid) 1488 { 1489 return genradix_ptr(&stream->out, sid); 1490 } 1491 sctp_stream_in(struct sctp_stream * stream,__u16 sid)1492 static inline struct sctp_stream_in *sctp_stream_in( 1493 struct sctp_stream *stream, 1494 __u16 sid) 1495 { 1496 return genradix_ptr(&stream->in, sid); 1497 } 1498 1499 #define SCTP_SO(s, i) sctp_stream_out((s), (i)) 1500 #define SCTP_SI(s, i) sctp_stream_in((s), (i)) 1501 1502 #define SCTP_STREAM_CLOSED 0x00 1503 #define SCTP_STREAM_OPEN 0x01 1504 sctp_datachk_len(const struct sctp_stream * stream)1505 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream) 1506 { 1507 return stream->si->data_chunk_len; 1508 } 1509 sctp_datahdr_len(const struct sctp_stream * stream)1510 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream) 1511 { 1512 return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr); 1513 } 1514 sctp_ftsnchk_len(const struct sctp_stream * stream)1515 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream) 1516 { 1517 return stream->si->ftsn_chunk_len; 1518 } 1519 sctp_ftsnhdr_len(const struct sctp_stream * stream)1520 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream) 1521 { 1522 return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr); 1523 } 1524 1525 /* SCTP_GET_ASSOC_STATS counters */ 1526 struct sctp_priv_assoc_stats { 1527 /* Maximum observed rto in the association during subsequent 1528 * observations. Value is set to 0 if no RTO measurement took place 1529 * The transport where the max_rto was observed is returned in 1530 * obs_rto_ipaddr 1531 */ 1532 struct sockaddr_storage obs_rto_ipaddr; 1533 __u64 max_obs_rto; 1534 /* Total In and Out SACKs received and sent */ 1535 __u64 isacks; 1536 __u64 osacks; 1537 /* Total In and Out packets received and sent */ 1538 __u64 opackets; 1539 __u64 ipackets; 1540 /* Total retransmitted chunks */ 1541 __u64 rtxchunks; 1542 /* TSN received > next expected */ 1543 __u64 outofseqtsns; 1544 /* Duplicate Chunks received */ 1545 __u64 idupchunks; 1546 /* Gap Ack Blocks received */ 1547 __u64 gapcnt; 1548 /* Unordered data chunks sent and received */ 1549 __u64 ouodchunks; 1550 __u64 iuodchunks; 1551 /* Ordered data chunks sent and received */ 1552 __u64 oodchunks; 1553 __u64 iodchunks; 1554 /* Control chunks sent and received */ 1555 __u64 octrlchunks; 1556 __u64 ictrlchunks; 1557 }; 1558 1559 /* RFC2960 1560 * 1561 * 12. Recommended Transmission Control Block (TCB) Parameters 1562 * 1563 * This section details a recommended set of parameters that should 1564 * be contained within the TCB for an implementation. This section is 1565 * for illustrative purposes and should not be deemed as requirements 1566 * on an implementation or as an exhaustive list of all parameters 1567 * inside an SCTP TCB. Each implementation may need its own additional 1568 * parameters for optimization. 1569 */ 1570 1571 1572 /* Here we have information about each individual association. */ 1573 struct sctp_association { 1574 1575 /* A base structure common to endpoint and association. 1576 * In this context, it represents the associations's view 1577 * of the local endpoint of the association. 1578 */ 1579 struct sctp_ep_common base; 1580 1581 /* Associations on the same socket. */ 1582 struct list_head asocs; 1583 1584 /* association id. */ 1585 sctp_assoc_t assoc_id; 1586 1587 /* This is our parent endpoint. */ 1588 struct sctp_endpoint *ep; 1589 1590 /* These are those association elements needed in the cookie. */ 1591 struct sctp_cookie c; 1592 1593 /* This is all information about our peer. */ 1594 struct { 1595 /* transport_addr_list 1596 * 1597 * Peer : A list of SCTP transport addresses that the 1598 * Transport : peer is bound to. This information is derived 1599 * Address : from the INIT or INIT ACK and is used to 1600 * List : associate an inbound packet with a given 1601 * : association. Normally this information is 1602 * : hashed or keyed for quick lookup and access 1603 * : of the TCB. 1604 * : The list is also initialized with the list 1605 * : of addresses passed with the sctp_connectx() 1606 * : call. 1607 * 1608 * It is a list of SCTP_transport's. 1609 */ 1610 struct list_head transport_addr_list; 1611 1612 /* rwnd 1613 * 1614 * Peer Rwnd : Current calculated value of the peer's rwnd. 1615 */ 1616 __u32 rwnd; 1617 1618 /* transport_count 1619 * 1620 * Peer : A count of the number of peer addresses 1621 * Transport : in the Peer Transport Address List. 1622 * Address : 1623 * Count : 1624 */ 1625 __u16 transport_count; 1626 1627 /* port 1628 * The transport layer port number. 1629 */ 1630 __u16 port; 1631 1632 /* primary_path 1633 * 1634 * Primary : This is the current primary destination 1635 * Path : transport address of the peer endpoint. It 1636 * : may also specify a source transport address 1637 * : on this endpoint. 1638 * 1639 * All of these paths live on transport_addr_list. 1640 * 1641 * At the bakeoffs, we discovered that the intent of 1642 * primaryPath is that it only changes when the ULP 1643 * asks to have it changed. We add the activePath to 1644 * designate the connection we are currently using to 1645 * transmit new data and most control chunks. 1646 */ 1647 struct sctp_transport *primary_path; 1648 1649 /* Cache the primary path address here, when we 1650 * need a an address for msg_name. 1651 */ 1652 union sctp_addr primary_addr; 1653 1654 /* active_path 1655 * The path that we are currently using to 1656 * transmit new data and most control chunks. 1657 */ 1658 struct sctp_transport *active_path; 1659 1660 /* retran_path 1661 * 1662 * RFC2960 6.4 Multi-homed SCTP Endpoints 1663 * ... 1664 * Furthermore, when its peer is multi-homed, an 1665 * endpoint SHOULD try to retransmit a chunk to an 1666 * active destination transport address that is 1667 * different from the last destination address to 1668 * which the DATA chunk was sent. 1669 */ 1670 struct sctp_transport *retran_path; 1671 1672 /* Pointer to last transport I have sent on. */ 1673 struct sctp_transport *last_sent_to; 1674 1675 /* This is the last transport I have received DATA on. */ 1676 struct sctp_transport *last_data_from; 1677 1678 /* 1679 * Mapping An array of bits or bytes indicating which out of 1680 * Array order TSN's have been received (relative to the 1681 * Last Rcvd TSN). If no gaps exist, i.e. no out of 1682 * order packets have been received, this array 1683 * will be set to all zero. This structure may be 1684 * in the form of a circular buffer or bit array. 1685 * 1686 * Last Rcvd : This is the last TSN received in 1687 * TSN : sequence. This value is set initially by 1688 * : taking the peer's Initial TSN, received in 1689 * : the INIT or INIT ACK chunk, and subtracting 1690 * : one from it. 1691 * 1692 * Throughout most of the specification this is called the 1693 * "Cumulative TSN ACK Point". In this case, we 1694 * ignore the advice in 12.2 in favour of the term 1695 * used in the bulk of the text. This value is hidden 1696 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). 1697 */ 1698 struct sctp_tsnmap tsn_map; 1699 1700 /* This mask is used to disable sending the ASCONF chunk 1701 * with specified parameter to peer. 1702 */ 1703 __be16 addip_disabled_mask; 1704 1705 /* These are capabilities which our peer advertised. */ 1706 __u16 ecn_capable:1, /* Can peer do ECN? */ 1707 ipv4_address:1, /* Peer understands IPv4 addresses? */ 1708 ipv6_address:1, /* Peer understands IPv6 addresses? */ 1709 asconf_capable:1, /* Does peer support ADDIP? */ 1710 prsctp_capable:1, /* Can peer do PR-SCTP? */ 1711 reconf_capable:1, /* Can peer do RE-CONFIG? */ 1712 intl_capable:1, /* Can peer do INTERLEAVE */ 1713 auth_capable:1, /* Is peer doing SCTP-AUTH? */ 1714 /* sack_needed: 1715 * This flag indicates if the next received 1716 * packet is to be responded to with a 1717 * SACK. This is initialized to 0. When a packet 1718 * is received sack_cnt is incremented. If this value 1719 * reaches 2 or more, a SACK is sent and the 1720 * value is reset to 0. Note: This is used only 1721 * when no DATA chunks are received out of 1722 * order. When DATA chunks are out of order, 1723 * SACK's are not delayed (see Section 6). 1724 */ 1725 sack_needed:1, /* Do we need to sack the peer? */ 1726 sack_generation:1, 1727 zero_window_announced:1; 1728 1729 __u32 sack_cnt; 1730 1731 __u32 adaptation_ind; /* Adaptation Code point. */ 1732 1733 struct sctp_inithdr_host i; 1734 void *cookie; 1735 int cookie_len; 1736 1737 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1738 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the 1739 * Initial TSN Value minus 1 1740 */ 1741 __u32 addip_serial; 1742 1743 /* SCTP-AUTH: We need to know pears random number, hmac list 1744 * and authenticated chunk list. All that is part of the 1745 * cookie and these are just pointers to those locations 1746 */ 1747 struct sctp_random_param *peer_random; 1748 struct sctp_chunks_param *peer_chunks; 1749 struct sctp_hmac_algo_param *peer_hmacs; 1750 } peer; 1751 1752 /* State : A state variable indicating what state the 1753 * : association is in, i.e. COOKIE-WAIT, 1754 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, 1755 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. 1756 * 1757 * Note: No "CLOSED" state is illustrated since if a 1758 * association is "CLOSED" its TCB SHOULD be removed. 1759 * 1760 * In this implementation we DO have a CLOSED 1761 * state which is used during initiation and shutdown. 1762 * 1763 * State takes values from SCTP_STATE_*. 1764 */ 1765 enum sctp_state state; 1766 1767 /* Overall : The overall association error count. 1768 * Error Count : [Clear this any time I get something.] 1769 */ 1770 int overall_error_count; 1771 1772 /* The cookie life I award for any cookie. */ 1773 ktime_t cookie_life; 1774 1775 /* These are the association's initial, max, and min RTO values. 1776 * These values will be initialized by system defaults, but can 1777 * be modified via the SCTP_RTOINFO socket option. 1778 */ 1779 unsigned long rto_initial; 1780 unsigned long rto_max; 1781 unsigned long rto_min; 1782 1783 /* Maximum number of new data packets that can be sent in a burst. */ 1784 int max_burst; 1785 1786 /* This is the max_retrans value for the association. This value will 1787 * be initialized from system defaults, but can be 1788 * modified by the SCTP_ASSOCINFO socket option. 1789 */ 1790 int max_retrans; 1791 1792 /* This is the partially failed retrans value for the transport 1793 * and will be initialized from the assocs value. This can be 1794 * changed using the SCTP_PEER_ADDR_THLDS socket option 1795 */ 1796 __u16 pf_retrans; 1797 /* Used for primary path switchover. */ 1798 __u16 ps_retrans; 1799 1800 /* Maximum number of times the endpoint will retransmit INIT */ 1801 __u16 max_init_attempts; 1802 1803 /* How many times have we resent an INIT? */ 1804 __u16 init_retries; 1805 1806 /* The largest timeout or RTO value to use in attempting an INIT */ 1807 unsigned long max_init_timeo; 1808 1809 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 1810 * the destination address every heartbeat interval. This value 1811 * will be inherited by all new transports. 1812 */ 1813 unsigned long hbinterval; 1814 unsigned long probe_interval; 1815 1816 __be16 encap_port; 1817 1818 /* This is the max_retrans value for new transports in the 1819 * association. 1820 */ 1821 __u16 pathmaxrxt; 1822 1823 __u32 flowlabel; 1824 __u8 dscp; 1825 1826 /* Flag that path mtu update is pending */ 1827 __u8 pmtu_pending; 1828 1829 /* Association : The smallest PMTU discovered for all of the 1830 * PMTU : peer's transport addresses. 1831 */ 1832 __u32 pathmtu; 1833 1834 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ 1835 __u32 param_flags; 1836 1837 __u32 sackfreq; 1838 /* SACK delay timeout */ 1839 unsigned long sackdelay; 1840 1841 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1842 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; 1843 1844 /* Transport to which SHUTDOWN chunk was last sent. */ 1845 struct sctp_transport *shutdown_last_sent_to; 1846 1847 /* Transport to which INIT chunk was last sent. */ 1848 struct sctp_transport *init_last_sent_to; 1849 1850 /* How many times have we resent a SHUTDOWN */ 1851 int shutdown_retries; 1852 1853 /* Next TSN : The next TSN number to be assigned to a new 1854 * : DATA chunk. This is sent in the INIT or INIT 1855 * : ACK chunk to the peer and incremented each 1856 * : time a DATA chunk is assigned a TSN 1857 * : (normally just prior to transmit or during 1858 * : fragmentation). 1859 */ 1860 __u32 next_tsn; 1861 1862 /* 1863 * Last Rcvd : This is the last TSN received in sequence. This value 1864 * TSN : is set initially by taking the peer's Initial TSN, 1865 * : received in the INIT or INIT ACK chunk, and 1866 * : subtracting one from it. 1867 * 1868 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. 1869 */ 1870 1871 __u32 ctsn_ack_point; 1872 1873 /* PR-SCTP Advanced.Peer.Ack.Point */ 1874 __u32 adv_peer_ack_point; 1875 1876 /* Highest TSN that is acknowledged by incoming SACKs. */ 1877 __u32 highest_sacked; 1878 1879 /* TSN marking the fast recovery exit point */ 1880 __u32 fast_recovery_exit; 1881 1882 /* Flag to track the current fast recovery state */ 1883 __u8 fast_recovery; 1884 1885 /* The number of unacknowledged data chunks. Reported through 1886 * the SCTP_STATUS sockopt. 1887 */ 1888 __u16 unack_data; 1889 1890 /* The total number of data chunks that we've had to retransmit 1891 * as the result of a T3 timer expiration 1892 */ 1893 __u32 rtx_data_chunks; 1894 1895 /* This is the association's receive buffer space. This value is used 1896 * to set a_rwnd field in an INIT or a SACK chunk. 1897 */ 1898 __u32 rwnd; 1899 1900 /* This is the last advertised value of rwnd over a SACK chunk. */ 1901 __u32 a_rwnd; 1902 1903 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed 1904 * to slop over a maximum of the association's frag_point. 1905 */ 1906 __u32 rwnd_over; 1907 1908 /* Keeps treack of rwnd pressure. This happens when we have 1909 * a window, but not receive buffer (i.e small packets). This one 1910 * is releases slowly (1 PMTU at a time ). 1911 */ 1912 __u32 rwnd_press; 1913 1914 /* This is the sndbuf size in use for the association. 1915 * This corresponds to the sndbuf size for the association, 1916 * as specified in the sk->sndbuf. 1917 */ 1918 int sndbuf_used; 1919 1920 /* This is the amount of memory that this association has allocated 1921 * in the receive path at any given time. 1922 */ 1923 atomic_t rmem_alloc; 1924 1925 /* This is the wait queue head for send requests waiting on 1926 * the association sndbuf space. 1927 */ 1928 wait_queue_head_t wait; 1929 1930 /* The message size at which SCTP fragmentation will occur. */ 1931 __u32 frag_point; 1932 __u32 user_frag; 1933 1934 /* Counter used to count INIT errors. */ 1935 int init_err_counter; 1936 1937 /* Count the number of INIT cycles (for doubling timeout). */ 1938 int init_cycle; 1939 1940 /* Default send parameters. */ 1941 __u16 default_stream; 1942 __u16 default_flags; 1943 __u32 default_ppid; 1944 __u32 default_context; 1945 __u32 default_timetolive; 1946 1947 /* Default receive parameters */ 1948 __u32 default_rcv_context; 1949 1950 /* Stream arrays */ 1951 struct sctp_stream stream; 1952 1953 /* All outbound chunks go through this structure. */ 1954 struct sctp_outq outqueue; 1955 1956 /* A smart pipe that will handle reordering and fragmentation, 1957 * as well as handle passing events up to the ULP. 1958 */ 1959 struct sctp_ulpq ulpq; 1960 1961 /* Last TSN that caused an ECNE Chunk to be sent. */ 1962 __u32 last_ecne_tsn; 1963 1964 /* Last TSN that caused a CWR Chunk to be sent. */ 1965 __u32 last_cwr_tsn; 1966 1967 /* How many duplicated TSNs have we seen? */ 1968 int numduptsns; 1969 1970 /* These are to support 1971 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses 1972 * and Enforcement of Flow and Message Limits" 1973 * <draft-ietf-tsvwg-addip-sctp-02.txt> 1974 * or "ADDIP" for short. 1975 */ 1976 1977 1978 1979 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1980 * 1981 * R1) One and only one ASCONF Chunk MAY be in transit and 1982 * unacknowledged at any one time. If a sender, after sending 1983 * an ASCONF chunk, decides it needs to transfer another 1984 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1985 * returns from the previous ASCONF Chunk before sending a 1986 * subsequent ASCONF. Note this restriction binds each side, 1987 * so at any time two ASCONF may be in-transit on any given 1988 * association (one sent from each endpoint). 1989 * 1990 * [This is our one-and-only-one ASCONF in flight. If we do 1991 * not have an ASCONF in flight, this is NULL.] 1992 */ 1993 struct sctp_chunk *addip_last_asconf; 1994 1995 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk. 1996 * 1997 * This is needed to implement items E1 - E4 of the updated 1998 * spec. Here is the justification: 1999 * 2000 * Since the peer may bundle multiple ASCONF chunks toward us, 2001 * we now need the ability to cache multiple ACKs. The section 2002 * describes in detail how they are cached and cleaned up. 2003 */ 2004 struct list_head asconf_ack_list; 2005 2006 /* These ASCONF chunks are waiting to be sent. 2007 * 2008 * These chunks can't be pushed to outqueue until receiving 2009 * ASCONF_ACK for the previous ASCONF indicated by 2010 * addip_last_asconf, so as to guarantee that only one ASCONF 2011 * is in flight at any time. 2012 * 2013 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 2014 * 2015 * In defining the ASCONF Chunk transfer procedures, it is 2016 * essential that these transfers MUST NOT cause congestion 2017 * within the network. To achieve this, we place these 2018 * restrictions on the transfer of ASCONF Chunks: 2019 * 2020 * R1) One and only one ASCONF Chunk MAY be in transit and 2021 * unacknowledged at any one time. If a sender, after sending 2022 * an ASCONF chunk, decides it needs to transfer another 2023 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 2024 * returns from the previous ASCONF Chunk before sending a 2025 * subsequent ASCONF. Note this restriction binds each side, 2026 * so at any time two ASCONF may be in-transit on any given 2027 * association (one sent from each endpoint). 2028 * 2029 * 2030 * [I really think this is EXACTLY the sort of intelligence 2031 * which already resides in sctp_outq. Please move this 2032 * queue and its supporting logic down there. --piggy] 2033 */ 2034 struct list_head addip_chunk_list; 2035 2036 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2037 * 2038 * A2) A serial number should be assigned to the Chunk. The 2039 * serial number SHOULD be a monotonically increasing 2040 * number. The serial number SHOULD be initialized at 2041 * the start of the association to the same value as the 2042 * Initial TSN and every time a new ASCONF chunk is created 2043 * it is incremented by one after assigning the serial number 2044 * to the newly created chunk. 2045 * 2046 * ADDIP 2047 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) 2048 * 2049 * Serial Number : 32 bits (unsigned integer) 2050 * 2051 * This value represents a Serial Number for the ASCONF 2052 * Chunk. The valid range of Serial Number is from 0 to 2053 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 2054 * after reaching 4294967295. 2055 */ 2056 __u32 addip_serial; 2057 int src_out_of_asoc_ok; 2058 union sctp_addr *asconf_addr_del_pending; 2059 struct sctp_transport *new_transport; 2060 2061 /* SCTP AUTH: list of the endpoint shared keys. These 2062 * keys are provided out of band by the user application 2063 * and can't change during the lifetime of the association 2064 */ 2065 struct list_head endpoint_shared_keys; 2066 2067 /* SCTP AUTH: 2068 * The current generated association shared key (secret) 2069 */ 2070 struct sctp_auth_bytes *asoc_shared_key; 2071 struct sctp_shared_key *shkey; 2072 2073 /* SCTP AUTH: hmac id of the first peer requested algorithm 2074 * that we support. 2075 */ 2076 __u16 default_hmac_id; 2077 2078 __u16 active_key_id; 2079 2080 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */ 2081 temp:1, /* Is it a temporary association? */ 2082 pf_expose:2, /* Expose pf state? */ 2083 force_delay:1; 2084 2085 __u8 strreset_enable; 2086 __u8 strreset_outstanding; /* request param count on the fly */ 2087 2088 __u32 strreset_outseq; /* Update after receiving response */ 2089 __u32 strreset_inseq; /* Update after receiving request */ 2090 __u32 strreset_result[2]; /* save the results of last 2 responses */ 2091 2092 struct sctp_chunk *strreset_chunk; /* save request chunk */ 2093 2094 struct sctp_priv_assoc_stats stats; 2095 2096 int sent_cnt_removable; 2097 2098 __u16 subscribe; 2099 2100 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1]; 2101 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1]; 2102 2103 /* Security identifiers from incoming (INIT). These are set by 2104 * security_sctp_assoc_request(). These will only be used by 2105 * SCTP TCP type sockets and peeled off connections as they 2106 * cause a new socket to be generated. security_sctp_sk_clone() 2107 * will then plug these into the new socket. 2108 */ 2109 2110 u32 secid; 2111 u32 peer_secid; 2112 2113 struct rcu_head rcu; 2114 }; 2115 2116 2117 /* An eyecatcher for determining if we are really looking at an 2118 * association data structure. 2119 */ 2120 enum { 2121 SCTP_ASSOC_EYECATCHER = 0xa550c123, 2122 }; 2123 2124 /* Recover the outer association structure. */ sctp_assoc(struct sctp_ep_common * base)2125 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) 2126 { 2127 struct sctp_association *asoc; 2128 2129 asoc = container_of(base, struct sctp_association, base); 2130 return asoc; 2131 } 2132 2133 /* These are function signatures for manipulating associations. */ 2134 2135 2136 struct sctp_association * 2137 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk, 2138 enum sctp_scope scope, gfp_t gfp); 2139 void sctp_association_free(struct sctp_association *); 2140 void sctp_association_put(struct sctp_association *); 2141 void sctp_association_hold(struct sctp_association *); 2142 2143 struct sctp_transport *sctp_assoc_choose_alter_transport( 2144 struct sctp_association *, struct sctp_transport *); 2145 void sctp_assoc_update_retran_path(struct sctp_association *); 2146 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, 2147 const union sctp_addr *); 2148 int sctp_assoc_lookup_laddr(struct sctp_association *asoc, 2149 const union sctp_addr *laddr); 2150 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, 2151 const union sctp_addr *address, 2152 const gfp_t gfp, 2153 const int peer_state); 2154 void sctp_assoc_del_peer(struct sctp_association *asoc, 2155 const union sctp_addr *addr); 2156 void sctp_assoc_rm_peer(struct sctp_association *asoc, 2157 struct sctp_transport *peer); 2158 void sctp_assoc_control_transport(struct sctp_association *asoc, 2159 struct sctp_transport *transport, 2160 enum sctp_transport_cmd command, 2161 sctp_sn_error_t error); 2162 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); 2163 void sctp_assoc_migrate(struct sctp_association *, struct sock *); 2164 int sctp_assoc_update(struct sctp_association *old, 2165 struct sctp_association *new); 2166 2167 __u32 sctp_association_get_next_tsn(struct sctp_association *); 2168 2169 void sctp_assoc_update_frag_point(struct sctp_association *asoc); 2170 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu); 2171 void sctp_assoc_sync_pmtu(struct sctp_association *asoc); 2172 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int); 2173 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int); 2174 void sctp_assoc_set_primary(struct sctp_association *, 2175 struct sctp_transport *); 2176 void sctp_assoc_del_nonprimary_peers(struct sctp_association *, 2177 struct sctp_transport *); 2178 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc, 2179 enum sctp_scope scope, gfp_t gfp); 2180 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, 2181 struct sctp_cookie*, 2182 gfp_t gfp); 2183 int sctp_assoc_set_id(struct sctp_association *, gfp_t); 2184 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc); 2185 struct sctp_chunk *sctp_assoc_lookup_asconf_ack( 2186 const struct sctp_association *asoc, 2187 __be32 serial); 2188 void sctp_asconf_queue_teardown(struct sctp_association *asoc); 2189 2190 int sctp_cmp_addr_exact(const union sctp_addr *ss1, 2191 const union sctp_addr *ss2); 2192 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); 2193 2194 /* A convenience structure to parse out SCTP specific CMSGs. */ 2195 struct sctp_cmsgs { 2196 struct sctp_initmsg *init; 2197 struct sctp_sndrcvinfo *srinfo; 2198 struct sctp_sndinfo *sinfo; 2199 struct sctp_prinfo *prinfo; 2200 struct sctp_authinfo *authinfo; 2201 struct msghdr *addrs_msg; 2202 }; 2203 2204 /* Structure for tracking memory objects */ 2205 struct sctp_dbg_objcnt_entry { 2206 char *label; 2207 atomic_t *counter; 2208 }; 2209 2210 #endif /* __sctp_structs_h__ */ 2211