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 static inline struct sctp_sock *sctp_sk(const struct sock *sk) 246 { 247 return (struct sctp_sock *)sk; 248 } 249 250 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp) 251 { 252 return (struct sock *)sp; 253 } 254 255 #if IS_ENABLED(CONFIG_IPV6) 256 struct sctp6_sock { 257 struct sctp_sock sctp; 258 struct ipv6_pinfo inet6; 259 }; 260 #endif /* CONFIG_IPV6 */ 261 262 263 /* This is our APPLICATION-SPECIFIC state cookie. 264 * THIS IS NOT DICTATED BY THE SPECIFICATION. 265 */ 266 /* These are the parts of an association which we send in the cookie. 267 * Most of these are straight out of: 268 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB) 269 * 270 */ 271 272 struct sctp_cookie { 273 274 /* My : Tag expected in every inbound packet and sent 275 * Verification: in the INIT or INIT ACK chunk. 276 * Tag : 277 */ 278 __u32 my_vtag; 279 280 /* Peer's : Tag expected in every outbound packet except 281 * Verification: in the INIT chunk. 282 * Tag : 283 */ 284 __u32 peer_vtag; 285 286 /* The rest of these are not from the spec, but really need to 287 * be in the cookie. 288 */ 289 290 /* My Tie Tag : Assist in discovering a restarting association. */ 291 __u32 my_ttag; 292 293 /* Peer's Tie Tag: Assist in discovering a restarting association. */ 294 __u32 peer_ttag; 295 296 /* When does this cookie expire? */ 297 ktime_t expiration; 298 299 /* Number of inbound/outbound streams which are set 300 * and negotiated during the INIT process. 301 */ 302 __u16 sinit_num_ostreams; 303 __u16 sinit_max_instreams; 304 305 /* This is the first sequence number I used. */ 306 __u32 initial_tsn; 307 308 /* This holds the originating address of the INIT packet. */ 309 union sctp_addr peer_addr; 310 311 /* IG Section 2.35.3 312 * Include the source port of the INIT-ACK 313 */ 314 __u16 my_port; 315 316 __u8 prsctp_capable; 317 318 /* Padding for future use */ 319 __u8 padding; 320 321 __u32 adaptation_ind; 322 323 __u8 auth_random[sizeof(struct sctp_paramhdr) + 324 SCTP_AUTH_RANDOM_LENGTH]; 325 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2]; 326 __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS]; 327 328 /* This is a shim for my peer's INIT packet, followed by 329 * a copy of the raw address list of the association. 330 * The length of the raw address list is saved in the 331 * raw_addr_list_len field, which will be used at the time when 332 * the association TCB is re-constructed from the cookie. 333 */ 334 __u32 raw_addr_list_len; 335 struct sctp_init_chunk peer_init[]; 336 }; 337 338 339 /* The format of our cookie that we send to our peer. */ 340 struct sctp_signed_cookie { 341 __u8 signature[SCTP_SECRET_SIZE]; 342 __u32 __pad; /* force sctp_cookie alignment to 64 bits */ 343 struct sctp_cookie c; 344 } __packed; 345 346 /* This is another convenience type to allocate memory for address 347 * params for the maximum size and pass such structures around 348 * internally. 349 */ 350 union sctp_addr_param { 351 struct sctp_paramhdr p; 352 struct sctp_ipv4addr_param v4; 353 struct sctp_ipv6addr_param v6; 354 }; 355 356 /* A convenience type to allow walking through the various 357 * parameters and avoid casting all over the place. 358 */ 359 union sctp_params { 360 void *v; 361 struct sctp_paramhdr *p; 362 struct sctp_cookie_preserve_param *life; 363 struct sctp_hostname_param *dns; 364 struct sctp_cookie_param *cookie; 365 struct sctp_supported_addrs_param *sat; 366 struct sctp_ipv4addr_param *v4; 367 struct sctp_ipv6addr_param *v6; 368 union sctp_addr_param *addr; 369 struct sctp_adaptation_ind_param *aind; 370 struct sctp_supported_ext_param *ext; 371 struct sctp_random_param *random; 372 struct sctp_chunks_param *chunks; 373 struct sctp_hmac_algo_param *hmac_algo; 374 struct sctp_addip_param *addip; 375 }; 376 377 /* RFC 2960. Section 3.3.5 Heartbeat. 378 * Heartbeat Information: variable length 379 * The Sender-specific Heartbeat Info field should normally include 380 * information about the sender's current time when this HEARTBEAT 381 * chunk is sent and the destination transport address to which this 382 * HEARTBEAT is sent (see Section 8.3). 383 */ 384 struct sctp_sender_hb_info { 385 struct sctp_paramhdr param_hdr; 386 union sctp_addr daddr; 387 unsigned long sent_at; 388 __u64 hb_nonce; 389 __u32 probe_size; 390 }; 391 392 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt, 393 gfp_t gfp); 394 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid); 395 void sctp_stream_free(struct sctp_stream *stream); 396 void sctp_stream_clear(struct sctp_stream *stream); 397 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new); 398 399 /* What is the current SSN number for this stream? */ 400 #define sctp_ssn_peek(stream, type, sid) \ 401 (sctp_stream_##type((stream), (sid))->ssn) 402 403 /* Return the next SSN number for this stream. */ 404 #define sctp_ssn_next(stream, type, sid) \ 405 (sctp_stream_##type((stream), (sid))->ssn++) 406 407 /* Skip over this ssn and all below. */ 408 #define sctp_ssn_skip(stream, type, sid, ssn) \ 409 (sctp_stream_##type((stream), (sid))->ssn = ssn + 1) 410 411 /* What is the current MID number for this stream? */ 412 #define sctp_mid_peek(stream, type, sid) \ 413 (sctp_stream_##type((stream), (sid))->mid) 414 415 /* Return the next MID number for this stream. */ 416 #define sctp_mid_next(stream, type, sid) \ 417 (sctp_stream_##type((stream), (sid))->mid++) 418 419 /* Skip over this mid and all below. */ 420 #define sctp_mid_skip(stream, type, sid, mid) \ 421 (sctp_stream_##type((stream), (sid))->mid = mid + 1) 422 423 /* What is the current MID_uo number for this stream? */ 424 #define sctp_mid_uo_peek(stream, type, sid) \ 425 (sctp_stream_##type((stream), (sid))->mid_uo) 426 427 /* Return the next MID_uo number for this stream. */ 428 #define sctp_mid_uo_next(stream, type, sid) \ 429 (sctp_stream_##type((stream), (sid))->mid_uo++) 430 431 /* 432 * Pointers to address related SCTP functions. 433 * (i.e. things that depend on the address family.) 434 */ 435 struct sctp_af { 436 int (*sctp_xmit) (struct sk_buff *skb, 437 struct sctp_transport *); 438 int (*setsockopt) (struct sock *sk, 439 int level, 440 int optname, 441 sockptr_t optval, 442 unsigned int optlen); 443 int (*getsockopt) (struct sock *sk, 444 int level, 445 int optname, 446 char __user *optval, 447 int __user *optlen); 448 void (*get_dst) (struct sctp_transport *t, 449 union sctp_addr *saddr, 450 struct flowi *fl, 451 struct sock *sk); 452 void (*get_saddr) (struct sctp_sock *sk, 453 struct sctp_transport *t, 454 struct flowi *fl); 455 void (*copy_addrlist) (struct list_head *, 456 struct net_device *); 457 int (*cmp_addr) (const union sctp_addr *addr1, 458 const union sctp_addr *addr2); 459 void (*addr_copy) (union sctp_addr *dst, 460 union sctp_addr *src); 461 void (*from_skb) (union sctp_addr *, 462 struct sk_buff *skb, 463 int saddr); 464 void (*from_sk) (union sctp_addr *, 465 struct sock *sk); 466 bool (*from_addr_param) (union sctp_addr *, 467 union sctp_addr_param *, 468 __be16 port, int iif); 469 int (*to_addr_param) (const union sctp_addr *, 470 union sctp_addr_param *); 471 int (*addr_valid) (union sctp_addr *, 472 struct sctp_sock *, 473 const struct sk_buff *); 474 enum sctp_scope (*scope)(union sctp_addr *); 475 void (*inaddr_any) (union sctp_addr *, __be16); 476 int (*is_any) (const union sctp_addr *); 477 int (*available) (union sctp_addr *, 478 struct sctp_sock *); 479 int (*skb_iif) (const struct sk_buff *sk); 480 int (*skb_sdif)(const struct sk_buff *sk); 481 int (*is_ce) (const struct sk_buff *sk); 482 void (*seq_dump_addr)(struct seq_file *seq, 483 union sctp_addr *addr); 484 void (*ecn_capable)(struct sock *sk); 485 __u16 net_header_len; 486 int sockaddr_len; 487 int (*ip_options_len)(struct sock *sk); 488 sa_family_t sa_family; 489 struct list_head list; 490 }; 491 492 struct sctp_af *sctp_get_af_specific(sa_family_t); 493 int sctp_register_af(struct sctp_af *); 494 495 /* Protocol family functions. */ 496 struct sctp_pf { 497 void (*event_msgname)(struct sctp_ulpevent *, char *, int *); 498 void (*skb_msgname) (struct sk_buff *, char *, int *); 499 int (*af_supported) (sa_family_t, struct sctp_sock *); 500 int (*cmp_addr) (const union sctp_addr *, 501 const union sctp_addr *, 502 struct sctp_sock *); 503 int (*bind_verify) (struct sctp_sock *, union sctp_addr *); 504 int (*send_verify) (struct sctp_sock *, union sctp_addr *); 505 int (*supported_addrs)(const struct sctp_sock *, __be16 *); 506 struct sock *(*create_accept_sk) (struct sock *sk, 507 struct sctp_association *asoc, 508 bool kern); 509 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr); 510 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk); 511 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk); 512 void (*copy_ip_options)(struct sock *sk, struct sock *newsk); 513 struct sctp_af *af; 514 }; 515 516 517 /* Structure to track chunk fragments that have been acked, but peer 518 * fragments of the same message have not. 519 */ 520 struct sctp_datamsg { 521 /* Chunks waiting to be submitted to lower layer. */ 522 struct list_head chunks; 523 /* Reference counting. */ 524 refcount_t refcnt; 525 /* When is this message no longer interesting to the peer? */ 526 unsigned long expires_at; 527 /* Did the messenge fail to send? */ 528 int send_error; 529 u8 send_failed:1, 530 can_delay:1, /* should this message be Nagle delayed */ 531 abandoned:1; /* should this message be abandoned */ 532 }; 533 534 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, 535 struct sctp_sndrcvinfo *, 536 struct iov_iter *); 537 void sctp_datamsg_free(struct sctp_datamsg *); 538 void sctp_datamsg_put(struct sctp_datamsg *); 539 void sctp_chunk_fail(struct sctp_chunk *, int error); 540 int sctp_chunk_abandoned(struct sctp_chunk *); 541 542 /* RFC2960 1.4 Key Terms 543 * 544 * o Chunk: A unit of information within an SCTP packet, consisting of 545 * a chunk header and chunk-specific content. 546 * 547 * As a matter of convenience, we remember the SCTP common header for 548 * each chunk as well as a few other header pointers... 549 */ 550 struct sctp_chunk { 551 struct list_head list; 552 553 refcount_t refcnt; 554 555 /* How many times this chunk have been sent, for prsctp RTX policy */ 556 int sent_count; 557 558 union { 559 /* This is our link to the per-transport transmitted list. */ 560 struct list_head transmitted_list; 561 /* List in specific stream outq */ 562 struct list_head stream_list; 563 }; 564 565 /* This field is used by chunks that hold fragmented data. 566 * For the first fragment this is the list that holds the rest of 567 * fragments. For the remaining fragments, this is the link to the 568 * frag_list maintained in the first fragment. 569 */ 570 struct list_head frag_list; 571 572 /* This points to the sk_buff containing the actual data. */ 573 struct sk_buff *skb; 574 575 union { 576 /* In case of GSO packets, this will store the head one */ 577 struct sk_buff *head_skb; 578 /* In case of auth enabled, this will point to the shkey */ 579 struct sctp_shared_key *shkey; 580 }; 581 582 /* These are the SCTP headers by reverse order in a packet. 583 * Note that some of these may happen more than once. In that 584 * case, we point at the "current" one, whatever that means 585 * for that level of header. 586 */ 587 588 /* We point this at the FIRST TLV parameter to chunk_hdr. */ 589 union sctp_params param_hdr; 590 union { 591 __u8 *v; 592 struct sctp_datahdr *data_hdr; 593 struct sctp_inithdr *init_hdr; 594 struct sctp_sackhdr *sack_hdr; 595 struct sctp_heartbeathdr *hb_hdr; 596 struct sctp_sender_hb_info *hbs_hdr; 597 struct sctp_shutdownhdr *shutdown_hdr; 598 struct sctp_signed_cookie *cookie_hdr; 599 struct sctp_ecnehdr *ecne_hdr; 600 struct sctp_cwrhdr *ecn_cwr_hdr; 601 struct sctp_errhdr *err_hdr; 602 struct sctp_addiphdr *addip_hdr; 603 struct sctp_fwdtsn_hdr *fwdtsn_hdr; 604 struct sctp_authhdr *auth_hdr; 605 struct sctp_idatahdr *idata_hdr; 606 struct sctp_ifwdtsn_hdr *ifwdtsn_hdr; 607 } subh; 608 609 __u8 *chunk_end; 610 611 struct sctp_chunkhdr *chunk_hdr; 612 struct sctphdr *sctp_hdr; 613 614 /* This needs to be recoverable for SCTP_SEND_FAILED events. */ 615 struct sctp_sndrcvinfo sinfo; 616 617 /* Which association does this belong to? */ 618 struct sctp_association *asoc; 619 620 /* What endpoint received this chunk? */ 621 struct sctp_ep_common *rcvr; 622 623 /* We fill this in if we are calculating RTT. */ 624 unsigned long sent_at; 625 626 /* What is the origin IP address for this chunk? */ 627 union sctp_addr source; 628 /* Destination address for this chunk. */ 629 union sctp_addr dest; 630 631 /* For outbound message, track all fragments for SEND_FAILED. */ 632 struct sctp_datamsg *msg; 633 634 /* For an inbound chunk, this tells us where it came from. 635 * For an outbound chunk, it tells us where we'd like it to 636 * go. It is NULL if we have no preference. 637 */ 638 struct sctp_transport *transport; 639 640 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO 641 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH 642 * spec violates the principle premis that all chunks are processed 643 * in order. 644 */ 645 struct sk_buff *auth_chunk; 646 647 #define SCTP_CAN_FRTX 0x0 648 #define SCTP_NEED_FRTX 0x1 649 #define SCTP_DONT_FRTX 0x2 650 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */ 651 has_tsn:1, /* Does this chunk have a TSN yet? */ 652 has_ssn:1, /* Does this chunk have a SSN yet? */ 653 #define has_mid has_ssn 654 singleton:1, /* Only chunk in the packet? */ 655 end_of_packet:1, /* Last chunk in the packet? */ 656 ecn_ce_done:1, /* Have we processed the ECN CE bit? */ 657 pdiscard:1, /* Discard the whole packet now? */ 658 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */ 659 data_accepted:1, /* At least 1 chunk accepted */ 660 auth:1, /* IN: was auth'ed | OUT: needs auth */ 661 has_asconf:1, /* IN: have seen an asconf before */ 662 pmtu_probe:1, /* Used by PLPMTUD, can be set in s HB chunk */ 663 tsn_missing_report:2, /* Data chunk missing counter. */ 664 fast_retransmit:2; /* Is this chunk fast retransmitted? */ 665 }; 666 667 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1) 668 void sctp_chunk_hold(struct sctp_chunk *); 669 void sctp_chunk_put(struct sctp_chunk *); 670 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 671 struct iov_iter *from); 672 void sctp_chunk_free(struct sctp_chunk *); 673 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); 674 struct sctp_chunk *sctp_chunkify(struct sk_buff *, 675 const struct sctp_association *, 676 struct sock *, gfp_t gfp); 677 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, 678 union sctp_addr *); 679 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); 680 681 static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch) 682 { 683 return ntohs(ch->subh.data_hdr->stream); 684 } 685 686 enum { 687 SCTP_ADDR_NEW, /* new address added to assoc/ep */ 688 SCTP_ADDR_SRC, /* address can be used as source */ 689 SCTP_ADDR_DEL, /* address about to be deleted */ 690 }; 691 692 /* This is a structure for holding either an IPv6 or an IPv4 address. */ 693 struct sctp_sockaddr_entry { 694 struct list_head list; 695 struct rcu_head rcu; 696 union sctp_addr a; 697 __u8 state; 698 __u8 valid; 699 }; 700 701 #define SCTP_ADDRESS_TICK_DELAY 500 702 703 /* This structure holds lists of chunks as we are assembling for 704 * transmission. 705 */ 706 struct sctp_packet { 707 /* These are the SCTP header values (host order) for the packet. */ 708 __u16 source_port; 709 __u16 destination_port; 710 __u32 vtag; 711 712 /* This contains the payload chunks. */ 713 struct list_head chunk_list; 714 715 /* This is the overhead of the sctp and ip headers. */ 716 size_t overhead; 717 /* This is the total size of all chunks INCLUDING padding. */ 718 size_t size; 719 /* This is the maximum size this packet may have */ 720 size_t max_size; 721 722 /* The packet is destined for this transport address. 723 * The function we finally use to pass down to the next lower 724 * layer lives in the transport structure. 725 */ 726 struct sctp_transport *transport; 727 728 /* pointer to the auth chunk for this packet */ 729 struct sctp_chunk *auth; 730 731 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */ 732 has_sack:1, /* This packet contains a SACK chunk. */ 733 has_auth:1, /* This packet contains an AUTH chunk */ 734 has_data:1, /* This packet contains at least 1 DATA chunk */ 735 ipfragok:1; /* So let ip fragment this packet */ 736 }; 737 738 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *, 739 __u16 sport, __u16 dport); 740 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int); 741 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet, 742 struct sctp_chunk *chunk, 743 int one_packet, gfp_t gfp); 744 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet, 745 struct sctp_chunk *chunk); 746 int sctp_packet_transmit(struct sctp_packet *, gfp_t); 747 void sctp_packet_free(struct sctp_packet *); 748 749 static inline int sctp_packet_empty(struct sctp_packet *packet) 750 { 751 return packet->size == packet->overhead; 752 } 753 754 /* This represents a remote transport address. 755 * For local transport addresses, we just use union sctp_addr. 756 * 757 * RFC2960 Section 1.4 Key Terms 758 * 759 * o Transport address: A Transport Address is traditionally defined 760 * by Network Layer address, Transport Layer protocol and Transport 761 * Layer port number. In the case of SCTP running over IP, a 762 * transport address is defined by the combination of an IP address 763 * and an SCTP port number (where SCTP is the Transport protocol). 764 * 765 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control 766 * 767 * o The sender keeps a separate congestion control parameter set for 768 * each of the destination addresses it can send to (not each 769 * source-destination pair but for each destination). The parameters 770 * should decay if the address is not used for a long enough time 771 * period. 772 * 773 */ 774 struct sctp_transport { 775 /* A list of transports. */ 776 struct list_head transports; 777 struct rhlist_head node; 778 779 /* Reference counting. */ 780 refcount_t refcnt; 781 /* RTO-Pending : A flag used to track if one of the DATA 782 * chunks sent to this address is currently being 783 * used to compute a RTT. If this flag is 0, 784 * the next DATA chunk sent to this destination 785 * should be used to compute a RTT and this flag 786 * should be set. Every time the RTT 787 * calculation completes (i.e. the DATA chunk 788 * is SACK'd) clear this flag. 789 */ 790 __u32 rto_pending:1, 791 792 /* 793 * hb_sent : a flag that signals that we have a pending 794 * heartbeat. 795 */ 796 hb_sent:1, 797 798 /* Is the Path MTU update pending on this tranport */ 799 pmtu_pending:1, 800 801 dst_pending_confirm:1, /* need to confirm neighbour */ 802 803 /* Has this transport moved the ctsn since we last sacked */ 804 sack_generation:1; 805 u32 dst_cookie; 806 807 struct flowi fl; 808 809 /* This is the peer's IP address and port. */ 810 union sctp_addr ipaddr; 811 812 /* These are the functions we call to handle LLP stuff. */ 813 struct sctp_af *af_specific; 814 815 /* Which association do we belong to? */ 816 struct sctp_association *asoc; 817 818 /* RFC2960 819 * 820 * 12.3 Per Transport Address Data 821 * 822 * For each destination transport address in the peer's 823 * address list derived from the INIT or INIT ACK chunk, a 824 * number of data elements needs to be maintained including: 825 */ 826 /* RTO : The current retransmission timeout value. */ 827 unsigned long rto; 828 829 __u32 rtt; /* This is the most recent RTT. */ 830 831 /* RTTVAR : The current RTT variation. */ 832 __u32 rttvar; 833 834 /* SRTT : The current smoothed round trip time. */ 835 __u32 srtt; 836 837 /* 838 * These are the congestion stats. 839 */ 840 /* cwnd : The current congestion window. */ 841 __u32 cwnd; /* This is the actual cwnd. */ 842 843 /* ssthresh : The current slow start threshold value. */ 844 __u32 ssthresh; 845 846 /* partial : The tracking method for increase of cwnd when in 847 * bytes acked : congestion avoidance mode (see Section 6.2.2) 848 */ 849 __u32 partial_bytes_acked; 850 851 /* Data that has been sent, but not acknowledged. */ 852 __u32 flight_size; 853 854 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */ 855 856 /* Destination */ 857 struct dst_entry *dst; 858 /* Source address. */ 859 union sctp_addr saddr; 860 861 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 862 * the destination address every heartbeat interval. 863 */ 864 unsigned long hbinterval; 865 unsigned long probe_interval; 866 867 /* SACK delay timeout */ 868 unsigned long sackdelay; 869 __u32 sackfreq; 870 871 atomic_t mtu_info; 872 873 /* When was the last time that we heard from this transport? We use 874 * this to pick new active and retran paths. 875 */ 876 ktime_t last_time_heard; 877 878 /* When was the last time that we sent a chunk using this 879 * transport? We use this to check for idle transports 880 */ 881 unsigned long last_time_sent; 882 883 /* Last time(in jiffies) when cwnd is reduced due to the congestion 884 * indication based on ECNE chunk. 885 */ 886 unsigned long last_time_ecne_reduced; 887 888 __be16 encap_port; 889 890 /* This is the max_retrans value for the transport and will 891 * be initialized from the assocs value. This can be changed 892 * using the SCTP_SET_PEER_ADDR_PARAMS socket option. 893 */ 894 __u16 pathmaxrxt; 895 896 __u32 flowlabel; 897 __u8 dscp; 898 899 /* This is the partially failed retrans value for the transport 900 * and will be initialized from the assocs value. This can be changed 901 * using the SCTP_PEER_ADDR_THLDS socket option 902 */ 903 __u16 pf_retrans; 904 /* Used for primary path switchover. */ 905 __u16 ps_retrans; 906 /* PMTU : The current known path MTU. */ 907 __u32 pathmtu; 908 909 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ 910 __u32 param_flags; 911 912 /* The number of times INIT has been sent on this transport. */ 913 int init_sent_count; 914 915 /* state : The current state of this destination, 916 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN. 917 */ 918 int state; 919 920 /* These are the error stats for this destination. */ 921 922 /* Error count : The current error count for this destination. */ 923 unsigned short error_count; 924 925 /* Per : A timer used by each destination. 926 * Destination : 927 * Timer : 928 * 929 * [Everywhere else in the text this is called T3-rtx. -ed] 930 */ 931 struct timer_list T3_rtx_timer; 932 933 /* Heartbeat timer is per destination. */ 934 struct timer_list hb_timer; 935 936 /* Timer to handle ICMP proto unreachable envets */ 937 struct timer_list proto_unreach_timer; 938 939 /* Timer to handler reconf chunk rtx */ 940 struct timer_list reconf_timer; 941 942 /* Timer to send a probe HB packet for PLPMTUD */ 943 struct timer_list probe_timer; 944 945 /* Since we're using per-destination retransmission timers 946 * (see above), we're also using per-destination "transmitted" 947 * queues. This probably ought to be a private struct 948 * accessible only within the outqueue, but it's not, yet. 949 */ 950 struct list_head transmitted; 951 952 /* We build bundle-able packets for this transport here. */ 953 struct sctp_packet packet; 954 955 /* This is the list of transports that have chunks to send. */ 956 struct list_head send_ready; 957 958 /* State information saved for SFR_CACC algorithm. The key 959 * idea in SFR_CACC is to maintain state at the sender on a 960 * per-destination basis when a changeover happens. 961 * char changeover_active; 962 * char cycling_changeover; 963 * __u32 next_tsn_at_change; 964 * char cacc_saw_newack; 965 */ 966 struct { 967 /* An unsigned integer, which stores the next TSN to be 968 * used by the sender, at the moment of changeover. 969 */ 970 __u32 next_tsn_at_change; 971 972 /* A flag which indicates the occurrence of a changeover */ 973 char changeover_active; 974 975 /* A flag which indicates whether the change of primary is 976 * the first switch to this destination address during an 977 * active switch. 978 */ 979 char cycling_changeover; 980 981 /* A temporary flag, which is used during the processing of 982 * a SACK to estimate the causative TSN(s)'s group. 983 */ 984 char cacc_saw_newack; 985 } cacc; 986 987 struct { 988 __u16 pmtu; 989 __u16 probe_size; 990 __u16 probe_high; 991 __u8 probe_count; 992 __u8 state; 993 } pl; /* plpmtud related */ 994 995 /* 64-bit random number sent with heartbeat. */ 996 __u64 hb_nonce; 997 998 struct rcu_head rcu; 999 }; 1000 1001 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *, 1002 gfp_t); 1003 void sctp_transport_set_owner(struct sctp_transport *, 1004 struct sctp_association *); 1005 void sctp_transport_route(struct sctp_transport *, union sctp_addr *, 1006 struct sctp_sock *); 1007 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk); 1008 void sctp_transport_free(struct sctp_transport *); 1009 void sctp_transport_reset_t3_rtx(struct sctp_transport *); 1010 void sctp_transport_reset_hb_timer(struct sctp_transport *); 1011 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport); 1012 void sctp_transport_reset_probe_timer(struct sctp_transport *transport); 1013 void sctp_transport_reset_raise_timer(struct sctp_transport *transport); 1014 int sctp_transport_hold(struct sctp_transport *); 1015 void sctp_transport_put(struct sctp_transport *); 1016 void sctp_transport_update_rto(struct sctp_transport *, __u32); 1017 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32); 1018 void sctp_transport_lower_cwnd(struct sctp_transport *t, 1019 enum sctp_lower_cwnd reason); 1020 void sctp_transport_burst_limited(struct sctp_transport *); 1021 void sctp_transport_burst_reset(struct sctp_transport *); 1022 unsigned long sctp_transport_timeout(struct sctp_transport *); 1023 void sctp_transport_reset(struct sctp_transport *t); 1024 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu); 1025 void sctp_transport_immediate_rtx(struct sctp_transport *); 1026 void sctp_transport_dst_release(struct sctp_transport *t); 1027 void sctp_transport_dst_confirm(struct sctp_transport *t); 1028 void sctp_transport_pl_send(struct sctp_transport *t); 1029 bool sctp_transport_pl_recv(struct sctp_transport *t); 1030 1031 1032 /* This is the structure we use to queue packets as they come into 1033 * SCTP. We write packets to it and read chunks from it. 1034 */ 1035 struct sctp_inq { 1036 /* This is actually a queue of sctp_chunk each 1037 * containing a partially decoded packet. 1038 */ 1039 struct list_head in_chunk_list; 1040 /* This is the packet which is currently off the in queue and is 1041 * being worked on through the inbound chunk processing. 1042 */ 1043 struct sctp_chunk *in_progress; 1044 1045 /* This is the delayed task to finish delivering inbound 1046 * messages. 1047 */ 1048 struct work_struct immediate; 1049 }; 1050 1051 void sctp_inq_init(struct sctp_inq *); 1052 void sctp_inq_free(struct sctp_inq *); 1053 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet); 1054 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *); 1055 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *); 1056 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t); 1057 1058 /* This is the structure we use to hold outbound chunks. You push 1059 * chunks in and they automatically pop out the other end as bundled 1060 * packets (it calls (*output_handler)()). 1061 * 1062 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1, 1063 * and 8.2 of the v13 draft. 1064 * 1065 * It handles retransmissions. The connection to the timeout portion 1066 * of the state machine is through sctp_..._timeout() and timeout_handler. 1067 * 1068 * If you feed it SACKs, it will eat them. 1069 * 1070 * If you give it big chunks, it will fragment them. 1071 * 1072 * It assigns TSN's to data chunks. This happens at the last possible 1073 * instant before transmission. 1074 * 1075 * When free()'d, it empties itself out via output_handler(). 1076 */ 1077 struct sctp_outq { 1078 struct sctp_association *asoc; 1079 1080 /* Data pending that has never been transmitted. */ 1081 struct list_head out_chunk_list; 1082 1083 /* Stream scheduler being used */ 1084 struct sctp_sched_ops *sched; 1085 1086 unsigned int out_qlen; /* Total length of queued data chunks. */ 1087 1088 /* Error of send failed, may used in SCTP_SEND_FAILED event. */ 1089 unsigned int error; 1090 1091 /* These are control chunks we want to send. */ 1092 struct list_head control_chunk_list; 1093 1094 /* These are chunks that have been sacked but are above the 1095 * CTSN, or cumulative tsn ack point. 1096 */ 1097 struct list_head sacked; 1098 1099 /* Put chunks on this list to schedule them for 1100 * retransmission. 1101 */ 1102 struct list_head retransmit; 1103 1104 /* Put chunks on this list to save them for FWD TSN processing as 1105 * they were abandoned. 1106 */ 1107 struct list_head abandoned; 1108 1109 /* How many unackd bytes do we have in-flight? */ 1110 __u32 outstanding_bytes; 1111 1112 /* Are we doing fast-rtx on this queue */ 1113 char fast_rtx; 1114 1115 /* Corked? */ 1116 char cork; 1117 }; 1118 1119 void sctp_outq_init(struct sctp_association *, struct sctp_outq *); 1120 void sctp_outq_teardown(struct sctp_outq *); 1121 void sctp_outq_free(struct sctp_outq*); 1122 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t); 1123 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *); 1124 int sctp_outq_is_empty(const struct sctp_outq *); 1125 void sctp_outq_restart(struct sctp_outq *); 1126 1127 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, 1128 enum sctp_retransmit_reason reason); 1129 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); 1130 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp); 1131 void sctp_prsctp_prune(struct sctp_association *asoc, 1132 struct sctp_sndrcvinfo *sinfo, int msg_len); 1133 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn); 1134 /* Uncork and flush an outqueue. */ 1135 static inline void sctp_outq_cork(struct sctp_outq *q) 1136 { 1137 q->cork = 1; 1138 } 1139 1140 /* SCTP skb control block. 1141 * sctp_input_cb is currently used on rx and sock rx queue 1142 */ 1143 struct sctp_input_cb { 1144 union { 1145 struct inet_skb_parm h4; 1146 #if IS_ENABLED(CONFIG_IPV6) 1147 struct inet6_skb_parm h6; 1148 #endif 1149 } header; 1150 struct sctp_chunk *chunk; 1151 struct sctp_af *af; 1152 __be16 encap_port; 1153 }; 1154 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0])) 1155 1156 struct sctp_output_cb { 1157 struct sk_buff *last; 1158 }; 1159 #define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0])) 1160 1161 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb) 1162 { 1163 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; 1164 1165 return chunk->head_skb ? : skb; 1166 } 1167 1168 /* These bind address data fields common between endpoints and associations */ 1169 struct sctp_bind_addr { 1170 1171 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1172 * 1173 * SCTP Port: The local SCTP port number the endpoint is 1174 * bound to. 1175 */ 1176 __u16 port; 1177 1178 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1179 * 1180 * Address List: The list of IP addresses that this instance 1181 * has bound. This information is passed to one's 1182 * peer(s) in INIT and INIT ACK chunks. 1183 */ 1184 struct list_head address_list; 1185 }; 1186 1187 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port); 1188 void sctp_bind_addr_free(struct sctp_bind_addr *); 1189 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest, 1190 const struct sctp_bind_addr *src, 1191 enum sctp_scope scope, gfp_t gfp, 1192 int flags); 1193 int sctp_bind_addr_dup(struct sctp_bind_addr *dest, 1194 const struct sctp_bind_addr *src, 1195 gfp_t gfp); 1196 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1197 int new_size, __u8 addr_state, gfp_t gfp); 1198 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *); 1199 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, 1200 struct sctp_sock *); 1201 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *, 1202 struct sctp_sock *, struct sctp_sock *); 1203 int sctp_bind_addr_state(const struct sctp_bind_addr *bp, 1204 const union sctp_addr *addr); 1205 int sctp_bind_addrs_check(struct sctp_sock *sp, 1206 struct sctp_sock *sp2, int cnt2); 1207 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 1208 const union sctp_addr *addrs, 1209 int addrcnt, 1210 struct sctp_sock *opt); 1211 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 1212 int *addrs_len, 1213 gfp_t gfp); 1214 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, 1215 __u16 port, gfp_t gfp); 1216 1217 enum sctp_scope sctp_scope(const union sctp_addr *addr); 1218 int sctp_in_scope(struct net *net, const union sctp_addr *addr, 1219 const enum sctp_scope scope); 1220 int sctp_is_any(struct sock *sk, const union sctp_addr *addr); 1221 int sctp_is_ep_boundall(struct sock *sk); 1222 1223 1224 /* What type of endpoint? */ 1225 enum sctp_endpoint_type { 1226 SCTP_EP_TYPE_SOCKET, 1227 SCTP_EP_TYPE_ASSOCIATION, 1228 }; 1229 1230 /* 1231 * A common base class to bridge the implmentation view of a 1232 * socket (usually listening) endpoint versus an association's 1233 * local endpoint. 1234 * This common structure is useful for several purposes: 1235 * 1) Common interface for lookup routines. 1236 * a) Subfunctions work for either endpoint or association 1237 * b) Single interface to lookup allows hiding the lookup lock rather 1238 * than acquiring it externally. 1239 * 2) Common interface for the inbound chunk handling/state machine. 1240 * 3) Common object handling routines for reference counting, etc. 1241 * 4) Disentangle association lookup from endpoint lookup, where we 1242 * do not have to find our endpoint to find our association. 1243 * 1244 */ 1245 1246 struct sctp_ep_common { 1247 /* Runtime type information. What kind of endpoint is this? */ 1248 enum sctp_endpoint_type type; 1249 1250 /* Some fields to help us manage this object. 1251 * refcnt - Reference count access to this object. 1252 * dead - Do not attempt to use this object. 1253 */ 1254 refcount_t refcnt; 1255 bool dead; 1256 1257 /* What socket does this endpoint belong to? */ 1258 struct sock *sk; 1259 1260 /* Cache netns and it won't change once set */ 1261 struct net *net; 1262 1263 /* This is where we receive inbound chunks. */ 1264 struct sctp_inq inqueue; 1265 1266 /* This substructure includes the defining parameters of the 1267 * endpoint: 1268 * bind_addr.port is our shared port number. 1269 * bind_addr.address_list is our set of local IP addresses. 1270 */ 1271 struct sctp_bind_addr bind_addr; 1272 }; 1273 1274 1275 /* RFC Section 1.4 Key Terms 1276 * 1277 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a 1278 * multi-homed host, an SCTP endpoint is represented to its peers as a 1279 * combination of a set of eligible destination transport addresses to 1280 * which SCTP packets can be sent and a set of eligible source 1281 * transport addresses from which SCTP packets can be received. 1282 * All transport addresses used by an SCTP endpoint must use the 1283 * same port number, but can use multiple IP addresses. A transport 1284 * address used by an SCTP endpoint must not be used by another 1285 * SCTP endpoint. In other words, a transport address is unique 1286 * to an SCTP endpoint. 1287 * 1288 * From an implementation perspective, each socket has one of these. 1289 * A TCP-style socket will have exactly one association on one of 1290 * these. An UDP-style socket will have multiple associations hanging 1291 * off one of these. 1292 */ 1293 1294 struct sctp_endpoint { 1295 /* Common substructure for endpoint and association. */ 1296 struct sctp_ep_common base; 1297 1298 /* Fields to help us manage our entries in the hash tables. */ 1299 struct hlist_node node; 1300 int hashent; 1301 1302 /* Associations: A list of current associations and mappings 1303 * to the data consumers for each association. This 1304 * may be in the form of a hash table or other 1305 * implementation dependent structure. The data 1306 * consumers may be process identification 1307 * information such as file descriptors, named pipe 1308 * pointer, or table pointers dependent on how SCTP 1309 * is implemented. 1310 */ 1311 /* This is really a list of struct sctp_association entries. */ 1312 struct list_head asocs; 1313 1314 /* Secret Key: A secret key used by this endpoint to compute 1315 * the MAC. This SHOULD be a cryptographic quality 1316 * random number with a sufficient length. 1317 * Discussion in [RFC1750] can be helpful in 1318 * selection of the key. 1319 */ 1320 __u8 secret_key[SCTP_SECRET_SIZE]; 1321 1322 /* digest: This is a digest of the sctp cookie. This field is 1323 * only used on the receive path when we try to validate 1324 * that the cookie has not been tampered with. We put 1325 * this here so we pre-allocate this once and can re-use 1326 * on every receive. 1327 */ 1328 __u8 *digest; 1329 1330 /* sendbuf acct. policy. */ 1331 __u32 sndbuf_policy; 1332 1333 /* rcvbuf acct. policy. */ 1334 __u32 rcvbuf_policy; 1335 1336 /* SCTP AUTH: array of the HMACs that will be allocated 1337 * we need this per association so that we don't serialize 1338 */ 1339 struct crypto_shash **auth_hmacs; 1340 1341 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */ 1342 struct sctp_hmac_algo_param *auth_hmacs_list; 1343 1344 /* SCTP-AUTH: chunks to authenticate encoded into parameter */ 1345 struct sctp_chunks_param *auth_chunk_list; 1346 1347 /* SCTP-AUTH: endpoint shared keys */ 1348 struct list_head endpoint_shared_keys; 1349 __u16 active_key_id; 1350 __u8 ecn_enable:1, 1351 auth_enable:1, 1352 intl_enable:1, 1353 prsctp_enable:1, 1354 asconf_enable:1, 1355 reconf_enable:1; 1356 1357 __u8 strreset_enable; 1358 struct rcu_head rcu; 1359 }; 1360 1361 /* Recover the outter endpoint structure. */ 1362 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) 1363 { 1364 struct sctp_endpoint *ep; 1365 1366 ep = container_of(base, struct sctp_endpoint, base); 1367 return ep; 1368 } 1369 1370 /* These are function signatures for manipulating endpoints. */ 1371 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t); 1372 void sctp_endpoint_free(struct sctp_endpoint *); 1373 void sctp_endpoint_put(struct sctp_endpoint *); 1374 int sctp_endpoint_hold(struct sctp_endpoint *ep); 1375 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); 1376 struct sctp_association *sctp_endpoint_lookup_assoc( 1377 const struct sctp_endpoint *ep, 1378 const union sctp_addr *paddr, 1379 struct sctp_transport **); 1380 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep, 1381 const union sctp_addr *paddr); 1382 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep, 1383 struct net *net, 1384 const union sctp_addr *laddr, 1385 int dif, int sdif); 1386 bool sctp_has_association(struct net *net, const union sctp_addr *laddr, 1387 const union sctp_addr *paddr, int dif, int sdif); 1388 1389 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 1390 const struct sctp_association *asoc, 1391 enum sctp_cid cid, struct sctp_init_chunk *peer_init, 1392 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk); 1393 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk, 1394 const union sctp_addr *peer, 1395 struct sctp_init_chunk *init, gfp_t gfp); 1396 __u32 sctp_generate_tag(const struct sctp_endpoint *); 1397 __u32 sctp_generate_tsn(const struct sctp_endpoint *); 1398 1399 struct sctp_inithdr_host { 1400 __u32 init_tag; 1401 __u32 a_rwnd; 1402 __u16 num_outbound_streams; 1403 __u16 num_inbound_streams; 1404 __u32 initial_tsn; 1405 }; 1406 1407 struct sctp_stream_priorities { 1408 /* List of priorities scheduled */ 1409 struct list_head prio_sched; 1410 /* List of streams scheduled */ 1411 struct list_head active; 1412 /* The next stream in line */ 1413 struct sctp_stream_out_ext *next; 1414 __u16 prio; 1415 __u16 users; 1416 }; 1417 1418 struct sctp_stream_out_ext { 1419 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1]; 1420 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1]; 1421 struct list_head outq; /* chunks enqueued by this stream */ 1422 union { 1423 struct { 1424 /* Scheduled streams list */ 1425 struct list_head prio_list; 1426 struct sctp_stream_priorities *prio_head; 1427 }; 1428 /* Fields used by RR scheduler */ 1429 struct { 1430 struct list_head rr_list; 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 }; 1479 struct sctp_stream_interleave *si; 1480 }; 1481 1482 static inline struct sctp_stream_out *sctp_stream_out( 1483 struct sctp_stream *stream, 1484 __u16 sid) 1485 { 1486 return genradix_ptr(&stream->out, sid); 1487 } 1488 1489 static inline struct sctp_stream_in *sctp_stream_in( 1490 struct sctp_stream *stream, 1491 __u16 sid) 1492 { 1493 return genradix_ptr(&stream->in, sid); 1494 } 1495 1496 #define SCTP_SO(s, i) sctp_stream_out((s), (i)) 1497 #define SCTP_SI(s, i) sctp_stream_in((s), (i)) 1498 1499 #define SCTP_STREAM_CLOSED 0x00 1500 #define SCTP_STREAM_OPEN 0x01 1501 1502 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream) 1503 { 1504 return stream->si->data_chunk_len; 1505 } 1506 1507 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream) 1508 { 1509 return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr); 1510 } 1511 1512 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream) 1513 { 1514 return stream->si->ftsn_chunk_len; 1515 } 1516 1517 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream) 1518 { 1519 return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr); 1520 } 1521 1522 /* SCTP_GET_ASSOC_STATS counters */ 1523 struct sctp_priv_assoc_stats { 1524 /* Maximum observed rto in the association during subsequent 1525 * observations. Value is set to 0 if no RTO measurement took place 1526 * The transport where the max_rto was observed is returned in 1527 * obs_rto_ipaddr 1528 */ 1529 struct sockaddr_storage obs_rto_ipaddr; 1530 __u64 max_obs_rto; 1531 /* Total In and Out SACKs received and sent */ 1532 __u64 isacks; 1533 __u64 osacks; 1534 /* Total In and Out packets received and sent */ 1535 __u64 opackets; 1536 __u64 ipackets; 1537 /* Total retransmitted chunks */ 1538 __u64 rtxchunks; 1539 /* TSN received > next expected */ 1540 __u64 outofseqtsns; 1541 /* Duplicate Chunks received */ 1542 __u64 idupchunks; 1543 /* Gap Ack Blocks received */ 1544 __u64 gapcnt; 1545 /* Unordered data chunks sent and received */ 1546 __u64 ouodchunks; 1547 __u64 iuodchunks; 1548 /* Ordered data chunks sent and received */ 1549 __u64 oodchunks; 1550 __u64 iodchunks; 1551 /* Control chunks sent and received */ 1552 __u64 octrlchunks; 1553 __u64 ictrlchunks; 1554 }; 1555 1556 /* RFC2960 1557 * 1558 * 12. Recommended Transmission Control Block (TCB) Parameters 1559 * 1560 * This section details a recommended set of parameters that should 1561 * be contained within the TCB for an implementation. This section is 1562 * for illustrative purposes and should not be deemed as requirements 1563 * on an implementation or as an exhaustive list of all parameters 1564 * inside an SCTP TCB. Each implementation may need its own additional 1565 * parameters for optimization. 1566 */ 1567 1568 1569 /* Here we have information about each individual association. */ 1570 struct sctp_association { 1571 1572 /* A base structure common to endpoint and association. 1573 * In this context, it represents the associations's view 1574 * of the local endpoint of the association. 1575 */ 1576 struct sctp_ep_common base; 1577 1578 /* Associations on the same socket. */ 1579 struct list_head asocs; 1580 1581 /* association id. */ 1582 sctp_assoc_t assoc_id; 1583 1584 /* This is our parent endpoint. */ 1585 struct sctp_endpoint *ep; 1586 1587 /* These are those association elements needed in the cookie. */ 1588 struct sctp_cookie c; 1589 1590 /* This is all information about our peer. */ 1591 struct { 1592 /* transport_addr_list 1593 * 1594 * Peer : A list of SCTP transport addresses that the 1595 * Transport : peer is bound to. This information is derived 1596 * Address : from the INIT or INIT ACK and is used to 1597 * List : associate an inbound packet with a given 1598 * : association. Normally this information is 1599 * : hashed or keyed for quick lookup and access 1600 * : of the TCB. 1601 * : The list is also initialized with the list 1602 * : of addresses passed with the sctp_connectx() 1603 * : call. 1604 * 1605 * It is a list of SCTP_transport's. 1606 */ 1607 struct list_head transport_addr_list; 1608 1609 /* rwnd 1610 * 1611 * Peer Rwnd : Current calculated value of the peer's rwnd. 1612 */ 1613 __u32 rwnd; 1614 1615 /* transport_count 1616 * 1617 * Peer : A count of the number of peer addresses 1618 * Transport : in the Peer Transport Address List. 1619 * Address : 1620 * Count : 1621 */ 1622 __u16 transport_count; 1623 1624 /* port 1625 * The transport layer port number. 1626 */ 1627 __u16 port; 1628 1629 /* primary_path 1630 * 1631 * Primary : This is the current primary destination 1632 * Path : transport address of the peer endpoint. It 1633 * : may also specify a source transport address 1634 * : on this endpoint. 1635 * 1636 * All of these paths live on transport_addr_list. 1637 * 1638 * At the bakeoffs, we discovered that the intent of 1639 * primaryPath is that it only changes when the ULP 1640 * asks to have it changed. We add the activePath to 1641 * designate the connection we are currently using to 1642 * transmit new data and most control chunks. 1643 */ 1644 struct sctp_transport *primary_path; 1645 1646 /* Cache the primary path address here, when we 1647 * need a an address for msg_name. 1648 */ 1649 union sctp_addr primary_addr; 1650 1651 /* active_path 1652 * The path that we are currently using to 1653 * transmit new data and most control chunks. 1654 */ 1655 struct sctp_transport *active_path; 1656 1657 /* retran_path 1658 * 1659 * RFC2960 6.4 Multi-homed SCTP Endpoints 1660 * ... 1661 * Furthermore, when its peer is multi-homed, an 1662 * endpoint SHOULD try to retransmit a chunk to an 1663 * active destination transport address that is 1664 * different from the last destination address to 1665 * which the DATA chunk was sent. 1666 */ 1667 struct sctp_transport *retran_path; 1668 1669 /* Pointer to last transport I have sent on. */ 1670 struct sctp_transport *last_sent_to; 1671 1672 /* This is the last transport I have received DATA on. */ 1673 struct sctp_transport *last_data_from; 1674 1675 /* 1676 * Mapping An array of bits or bytes indicating which out of 1677 * Array order TSN's have been received (relative to the 1678 * Last Rcvd TSN). If no gaps exist, i.e. no out of 1679 * order packets have been received, this array 1680 * will be set to all zero. This structure may be 1681 * in the form of a circular buffer or bit array. 1682 * 1683 * Last Rcvd : This is the last TSN received in 1684 * TSN : sequence. This value is set initially by 1685 * : taking the peer's Initial TSN, received in 1686 * : the INIT or INIT ACK chunk, and subtracting 1687 * : one from it. 1688 * 1689 * Throughout most of the specification this is called the 1690 * "Cumulative TSN ACK Point". In this case, we 1691 * ignore the advice in 12.2 in favour of the term 1692 * used in the bulk of the text. This value is hidden 1693 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). 1694 */ 1695 struct sctp_tsnmap tsn_map; 1696 1697 /* This mask is used to disable sending the ASCONF chunk 1698 * with specified parameter to peer. 1699 */ 1700 __be16 addip_disabled_mask; 1701 1702 /* These are capabilities which our peer advertised. */ 1703 __u16 ecn_capable:1, /* Can peer do ECN? */ 1704 ipv4_address:1, /* Peer understands IPv4 addresses? */ 1705 ipv6_address:1, /* Peer understands IPv6 addresses? */ 1706 hostname_address:1, /* Peer understands DNS addresses? */ 1707 asconf_capable:1, /* Does peer support ADDIP? */ 1708 prsctp_capable:1, /* Can peer do PR-SCTP? */ 1709 reconf_capable:1, /* Can peer do RE-CONFIG? */ 1710 intl_capable:1, /* Can peer do INTERLEAVE */ 1711 auth_capable:1, /* Is peer doing SCTP-AUTH? */ 1712 /* sack_needed: 1713 * This flag indicates if the next received 1714 * packet is to be responded to with a 1715 * SACK. This is initialized to 0. When a packet 1716 * is received sack_cnt is incremented. If this value 1717 * reaches 2 or more, a SACK is sent and the 1718 * value is reset to 0. Note: This is used only 1719 * when no DATA chunks are received out of 1720 * order. When DATA chunks are out of order, 1721 * SACK's are not delayed (see Section 6). 1722 */ 1723 sack_needed:1, /* Do we need to sack the peer? */ 1724 sack_generation:1, 1725 zero_window_announced:1; 1726 1727 __u32 sack_cnt; 1728 1729 __u32 adaptation_ind; /* Adaptation Code point. */ 1730 1731 struct sctp_inithdr_host i; 1732 void *cookie; 1733 int cookie_len; 1734 1735 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1736 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the 1737 * Initial TSN Value minus 1 1738 */ 1739 __u32 addip_serial; 1740 1741 /* SCTP-AUTH: We need to know pears random number, hmac list 1742 * and authenticated chunk list. All that is part of the 1743 * cookie and these are just pointers to those locations 1744 */ 1745 struct sctp_random_param *peer_random; 1746 struct sctp_chunks_param *peer_chunks; 1747 struct sctp_hmac_algo_param *peer_hmacs; 1748 } peer; 1749 1750 /* State : A state variable indicating what state the 1751 * : association is in, i.e. COOKIE-WAIT, 1752 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, 1753 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. 1754 * 1755 * Note: No "CLOSED" state is illustrated since if a 1756 * association is "CLOSED" its TCB SHOULD be removed. 1757 * 1758 * In this implementation we DO have a CLOSED 1759 * state which is used during initiation and shutdown. 1760 * 1761 * State takes values from SCTP_STATE_*. 1762 */ 1763 enum sctp_state state; 1764 1765 /* Overall : The overall association error count. 1766 * Error Count : [Clear this any time I get something.] 1767 */ 1768 int overall_error_count; 1769 1770 /* The cookie life I award for any cookie. */ 1771 ktime_t cookie_life; 1772 1773 /* These are the association's initial, max, and min RTO values. 1774 * These values will be initialized by system defaults, but can 1775 * be modified via the SCTP_RTOINFO socket option. 1776 */ 1777 unsigned long rto_initial; 1778 unsigned long rto_max; 1779 unsigned long rto_min; 1780 1781 /* Maximum number of new data packets that can be sent in a burst. */ 1782 int max_burst; 1783 1784 /* This is the max_retrans value for the association. This value will 1785 * be initialized from system defaults, but can be 1786 * modified by the SCTP_ASSOCINFO socket option. 1787 */ 1788 int max_retrans; 1789 1790 /* This is the partially failed retrans value for the transport 1791 * and will be initialized from the assocs value. This can be 1792 * changed using the SCTP_PEER_ADDR_THLDS socket option 1793 */ 1794 __u16 pf_retrans; 1795 /* Used for primary path switchover. */ 1796 __u16 ps_retrans; 1797 1798 /* Maximum number of times the endpoint will retransmit INIT */ 1799 __u16 max_init_attempts; 1800 1801 /* How many times have we resent an INIT? */ 1802 __u16 init_retries; 1803 1804 /* The largest timeout or RTO value to use in attempting an INIT */ 1805 unsigned long max_init_timeo; 1806 1807 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 1808 * the destination address every heartbeat interval. This value 1809 * will be inherited by all new transports. 1810 */ 1811 unsigned long hbinterval; 1812 unsigned long probe_interval; 1813 1814 __be16 encap_port; 1815 1816 /* This is the max_retrans value for new transports in the 1817 * association. 1818 */ 1819 __u16 pathmaxrxt; 1820 1821 __u32 flowlabel; 1822 __u8 dscp; 1823 1824 /* Flag that path mtu update is pending */ 1825 __u8 pmtu_pending; 1826 1827 /* Association : The smallest PMTU discovered for all of the 1828 * PMTU : peer's transport addresses. 1829 */ 1830 __u32 pathmtu; 1831 1832 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ 1833 __u32 param_flags; 1834 1835 __u32 sackfreq; 1836 /* SACK delay timeout */ 1837 unsigned long sackdelay; 1838 1839 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1840 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; 1841 1842 /* Transport to which SHUTDOWN chunk was last sent. */ 1843 struct sctp_transport *shutdown_last_sent_to; 1844 1845 /* Transport to which INIT chunk was last sent. */ 1846 struct sctp_transport *init_last_sent_to; 1847 1848 /* How many times have we resent a SHUTDOWN */ 1849 int shutdown_retries; 1850 1851 /* Next TSN : The next TSN number to be assigned to a new 1852 * : DATA chunk. This is sent in the INIT or INIT 1853 * : ACK chunk to the peer and incremented each 1854 * : time a DATA chunk is assigned a TSN 1855 * : (normally just prior to transmit or during 1856 * : fragmentation). 1857 */ 1858 __u32 next_tsn; 1859 1860 /* 1861 * Last Rcvd : This is the last TSN received in sequence. This value 1862 * TSN : is set initially by taking the peer's Initial TSN, 1863 * : received in the INIT or INIT ACK chunk, and 1864 * : subtracting one from it. 1865 * 1866 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. 1867 */ 1868 1869 __u32 ctsn_ack_point; 1870 1871 /* PR-SCTP Advanced.Peer.Ack.Point */ 1872 __u32 adv_peer_ack_point; 1873 1874 /* Highest TSN that is acknowledged by incoming SACKs. */ 1875 __u32 highest_sacked; 1876 1877 /* TSN marking the fast recovery exit point */ 1878 __u32 fast_recovery_exit; 1879 1880 /* Flag to track the current fast recovery state */ 1881 __u8 fast_recovery; 1882 1883 /* The number of unacknowledged data chunks. Reported through 1884 * the SCTP_STATUS sockopt. 1885 */ 1886 __u16 unack_data; 1887 1888 /* The total number of data chunks that we've had to retransmit 1889 * as the result of a T3 timer expiration 1890 */ 1891 __u32 rtx_data_chunks; 1892 1893 /* This is the association's receive buffer space. This value is used 1894 * to set a_rwnd field in an INIT or a SACK chunk. 1895 */ 1896 __u32 rwnd; 1897 1898 /* This is the last advertised value of rwnd over a SACK chunk. */ 1899 __u32 a_rwnd; 1900 1901 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed 1902 * to slop over a maximum of the association's frag_point. 1903 */ 1904 __u32 rwnd_over; 1905 1906 /* Keeps treack of rwnd pressure. This happens when we have 1907 * a window, but not recevie buffer (i.e small packets). This one 1908 * is releases slowly (1 PMTU at a time ). 1909 */ 1910 __u32 rwnd_press; 1911 1912 /* This is the sndbuf size in use for the association. 1913 * This corresponds to the sndbuf size for the association, 1914 * as specified in the sk->sndbuf. 1915 */ 1916 int sndbuf_used; 1917 1918 /* This is the amount of memory that this association has allocated 1919 * in the receive path at any given time. 1920 */ 1921 atomic_t rmem_alloc; 1922 1923 /* This is the wait queue head for send requests waiting on 1924 * the association sndbuf space. 1925 */ 1926 wait_queue_head_t wait; 1927 1928 /* The message size at which SCTP fragmentation will occur. */ 1929 __u32 frag_point; 1930 __u32 user_frag; 1931 1932 /* Counter used to count INIT errors. */ 1933 int init_err_counter; 1934 1935 /* Count the number of INIT cycles (for doubling timeout). */ 1936 int init_cycle; 1937 1938 /* Default send parameters. */ 1939 __u16 default_stream; 1940 __u16 default_flags; 1941 __u32 default_ppid; 1942 __u32 default_context; 1943 __u32 default_timetolive; 1944 1945 /* Default receive parameters */ 1946 __u32 default_rcv_context; 1947 1948 /* Stream arrays */ 1949 struct sctp_stream stream; 1950 1951 /* All outbound chunks go through this structure. */ 1952 struct sctp_outq outqueue; 1953 1954 /* A smart pipe that will handle reordering and fragmentation, 1955 * as well as handle passing events up to the ULP. 1956 */ 1957 struct sctp_ulpq ulpq; 1958 1959 /* Last TSN that caused an ECNE Chunk to be sent. */ 1960 __u32 last_ecne_tsn; 1961 1962 /* Last TSN that caused a CWR Chunk to be sent. */ 1963 __u32 last_cwr_tsn; 1964 1965 /* How many duplicated TSNs have we seen? */ 1966 int numduptsns; 1967 1968 /* These are to support 1969 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses 1970 * and Enforcement of Flow and Message Limits" 1971 * <draft-ietf-tsvwg-addip-sctp-02.txt> 1972 * or "ADDIP" for short. 1973 */ 1974 1975 1976 1977 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1978 * 1979 * R1) One and only one ASCONF Chunk MAY be in transit and 1980 * unacknowledged at any one time. If a sender, after sending 1981 * an ASCONF chunk, decides it needs to transfer another 1982 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1983 * returns from the previous ASCONF Chunk before sending a 1984 * subsequent ASCONF. Note this restriction binds each side, 1985 * so at any time two ASCONF may be in-transit on any given 1986 * association (one sent from each endpoint). 1987 * 1988 * [This is our one-and-only-one ASCONF in flight. If we do 1989 * not have an ASCONF in flight, this is NULL.] 1990 */ 1991 struct sctp_chunk *addip_last_asconf; 1992 1993 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk. 1994 * 1995 * This is needed to implement itmes E1 - E4 of the updated 1996 * spec. Here is the justification: 1997 * 1998 * Since the peer may bundle multiple ASCONF chunks toward us, 1999 * we now need the ability to cache multiple ACKs. The section 2000 * describes in detail how they are cached and cleaned up. 2001 */ 2002 struct list_head asconf_ack_list; 2003 2004 /* These ASCONF chunks are waiting to be sent. 2005 * 2006 * These chunaks can't be pushed to outqueue until receiving 2007 * ASCONF_ACK for the previous ASCONF indicated by 2008 * addip_last_asconf, so as to guarantee that only one ASCONF 2009 * is in flight at any time. 2010 * 2011 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 2012 * 2013 * In defining the ASCONF Chunk transfer procedures, it is 2014 * essential that these transfers MUST NOT cause congestion 2015 * within the network. To achieve this, we place these 2016 * restrictions on the transfer of ASCONF Chunks: 2017 * 2018 * R1) One and only one ASCONF Chunk MAY be in transit and 2019 * unacknowledged at any one time. If a sender, after sending 2020 * an ASCONF chunk, decides it needs to transfer another 2021 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 2022 * returns from the previous ASCONF Chunk before sending a 2023 * subsequent ASCONF. Note this restriction binds each side, 2024 * so at any time two ASCONF may be in-transit on any given 2025 * association (one sent from each endpoint). 2026 * 2027 * 2028 * [I really think this is EXACTLY the sort of intelligence 2029 * which already resides in sctp_outq. Please move this 2030 * queue and its supporting logic down there. --piggy] 2031 */ 2032 struct list_head addip_chunk_list; 2033 2034 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2035 * 2036 * A2) A serial number should be assigned to the Chunk. The 2037 * serial number SHOULD be a monotonically increasing 2038 * number. The serial number SHOULD be initialized at 2039 * the start of the association to the same value as the 2040 * Initial TSN and every time a new ASCONF chunk is created 2041 * it is incremented by one after assigning the serial number 2042 * to the newly created chunk. 2043 * 2044 * ADDIP 2045 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) 2046 * 2047 * Serial Number : 32 bits (unsigned integer) 2048 * 2049 * This value represents a Serial Number for the ASCONF 2050 * Chunk. The valid range of Serial Number is from 0 to 2051 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 2052 * after reaching 4294967295. 2053 */ 2054 __u32 addip_serial; 2055 int src_out_of_asoc_ok; 2056 union sctp_addr *asconf_addr_del_pending; 2057 struct sctp_transport *new_transport; 2058 2059 /* SCTP AUTH: list of the endpoint shared keys. These 2060 * keys are provided out of band by the user applicaton 2061 * and can't change during the lifetime of the association 2062 */ 2063 struct list_head endpoint_shared_keys; 2064 2065 /* SCTP AUTH: 2066 * The current generated assocaition shared key (secret) 2067 */ 2068 struct sctp_auth_bytes *asoc_shared_key; 2069 struct sctp_shared_key *shkey; 2070 2071 /* SCTP AUTH: hmac id of the first peer requested algorithm 2072 * that we support. 2073 */ 2074 __u16 default_hmac_id; 2075 2076 __u16 active_key_id; 2077 2078 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */ 2079 temp:1, /* Is it a temporary association? */ 2080 pf_expose:2, /* Expose pf state? */ 2081 force_delay:1; 2082 2083 __u8 strreset_enable; 2084 __u8 strreset_outstanding; /* request param count on the fly */ 2085 2086 __u32 strreset_outseq; /* Update after receiving response */ 2087 __u32 strreset_inseq; /* Update after receiving request */ 2088 __u32 strreset_result[2]; /* save the results of last 2 responses */ 2089 2090 struct sctp_chunk *strreset_chunk; /* save request chunk */ 2091 2092 struct sctp_priv_assoc_stats stats; 2093 2094 int sent_cnt_removable; 2095 2096 __u16 subscribe; 2097 2098 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1]; 2099 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1]; 2100 2101 /* Security identifiers from incoming (INIT). These are set by 2102 * security_sctp_assoc_request(). These will only be used by 2103 * SCTP TCP type sockets and peeled off connections as they 2104 * cause a new socket to be generated. security_sctp_sk_clone() 2105 * will then plug these into the new socket. 2106 */ 2107 2108 u32 secid; 2109 u32 peer_secid; 2110 2111 struct rcu_head rcu; 2112 }; 2113 2114 2115 /* An eyecatcher for determining if we are really looking at an 2116 * association data structure. 2117 */ 2118 enum { 2119 SCTP_ASSOC_EYECATCHER = 0xa550c123, 2120 }; 2121 2122 /* Recover the outter association structure. */ 2123 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) 2124 { 2125 struct sctp_association *asoc; 2126 2127 asoc = container_of(base, struct sctp_association, base); 2128 return asoc; 2129 } 2130 2131 /* These are function signatures for manipulating associations. */ 2132 2133 2134 struct sctp_association * 2135 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk, 2136 enum sctp_scope scope, gfp_t gfp); 2137 void sctp_association_free(struct sctp_association *); 2138 void sctp_association_put(struct sctp_association *); 2139 void sctp_association_hold(struct sctp_association *); 2140 2141 struct sctp_transport *sctp_assoc_choose_alter_transport( 2142 struct sctp_association *, struct sctp_transport *); 2143 void sctp_assoc_update_retran_path(struct sctp_association *); 2144 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, 2145 const union sctp_addr *); 2146 int sctp_assoc_lookup_laddr(struct sctp_association *asoc, 2147 const union sctp_addr *laddr); 2148 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, 2149 const union sctp_addr *address, 2150 const gfp_t gfp, 2151 const int peer_state); 2152 void sctp_assoc_del_peer(struct sctp_association *asoc, 2153 const union sctp_addr *addr); 2154 void sctp_assoc_rm_peer(struct sctp_association *asoc, 2155 struct sctp_transport *peer); 2156 void sctp_assoc_control_transport(struct sctp_association *asoc, 2157 struct sctp_transport *transport, 2158 enum sctp_transport_cmd command, 2159 sctp_sn_error_t error); 2160 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); 2161 void sctp_assoc_migrate(struct sctp_association *, struct sock *); 2162 int sctp_assoc_update(struct sctp_association *old, 2163 struct sctp_association *new); 2164 2165 __u32 sctp_association_get_next_tsn(struct sctp_association *); 2166 2167 void sctp_assoc_update_frag_point(struct sctp_association *asoc); 2168 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu); 2169 void sctp_assoc_sync_pmtu(struct sctp_association *asoc); 2170 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int); 2171 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int); 2172 void sctp_assoc_set_primary(struct sctp_association *, 2173 struct sctp_transport *); 2174 void sctp_assoc_del_nonprimary_peers(struct sctp_association *, 2175 struct sctp_transport *); 2176 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc, 2177 enum sctp_scope scope, gfp_t gfp); 2178 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, 2179 struct sctp_cookie*, 2180 gfp_t gfp); 2181 int sctp_assoc_set_id(struct sctp_association *, gfp_t); 2182 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc); 2183 struct sctp_chunk *sctp_assoc_lookup_asconf_ack( 2184 const struct sctp_association *asoc, 2185 __be32 serial); 2186 void sctp_asconf_queue_teardown(struct sctp_association *asoc); 2187 2188 int sctp_cmp_addr_exact(const union sctp_addr *ss1, 2189 const union sctp_addr *ss2); 2190 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); 2191 2192 /* A convenience structure to parse out SCTP specific CMSGs. */ 2193 struct sctp_cmsgs { 2194 struct sctp_initmsg *init; 2195 struct sctp_sndrcvinfo *srinfo; 2196 struct sctp_sndinfo *sinfo; 2197 struct sctp_prinfo *prinfo; 2198 struct sctp_authinfo *authinfo; 2199 struct msghdr *addrs_msg; 2200 }; 2201 2202 /* Structure for tracking memory objects */ 2203 struct sctp_dbg_objcnt_entry { 2204 char *label; 2205 atomic_t *counter; 2206 }; 2207 2208 #endif /* __sctp_structs_h__ */ 2209