1/* SCTP kernel implementation 2 * (C) Copyright IBM Corp. 2001, 2004 3 * Copyright (c) 1999-2000 Cisco, Inc. 4 * Copyright (c) 1999-2001 Motorola, Inc. 5 * Copyright (c) 2001 Intel Corp. 6 * 7 * This file is part of the SCTP kernel implementation 8 * 9 * This SCTP implementation is free software; 10 * you can redistribute it and/or modify it under the terms of 11 * the GNU General Public License as published by 12 * the Free Software Foundation; either version 2, or (at your option) 13 * any later version. 14 * 15 * This SCTP implementation is distributed in the hope that it 16 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 17 * ************************ 18 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 19 * See the GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with GNU CC; see the file COPYING. If not, write to 23 * the Free Software Foundation, 59 Temple Place - Suite 330, 24 * Boston, MA 02111-1307, USA. 25 * 26 * Please send any bug reports or fixes you make to the 27 * email addresses: 28 * lksctp developers <lksctp-developers@lists.sourceforge.net> 29 * 30 * Or submit a bug report through the following website: 31 * http://www.sf.net/projects/lksctp 32 * 33 * Written or modified by: 34 * Randall Stewart <randall@sctp.chicago.il.us> 35 * Ken Morneau <kmorneau@cisco.com> 36 * Qiaobing Xie <qxie1@email.mot.com> 37 * La Monte H.P. Yarroll <piggy@acm.org> 38 * Karl Knutson <karl@athena.chicago.il.us> 39 * Jon Grimm <jgrimm@us.ibm.com> 40 * Xingang Guo <xingang.guo@intel.com> 41 * Hui Huang <hui.huang@nokia.com> 42 * Sridhar Samudrala <sri@us.ibm.com> 43 * Daisy Chang <daisyc@us.ibm.com> 44 * Dajiang Zhang <dajiang.zhang@nokia.com> 45 * Ardelle Fan <ardelle.fan@intel.com> 46 * Ryan Layer <rmlayer@us.ibm.com> 47 * Anup Pemmaiah <pemmaiah@cc.usu.edu> 48 * Kevin Gao <kevin.gao@intel.com> 49 * 50 * Any bugs reported given to us we will try to fix... any fixes shared will 51 * be incorporated into the next SCTP release. 52 */ 53 54#ifndef __sctp_structs_h__ 55#define __sctp_structs_h__ 56 57#include <linux/ktime.h> 58#include <linux/socket.h> /* linux/in.h needs this!! */ 59#include <linux/in.h> /* We get struct sockaddr_in. */ 60#include <linux/in6.h> /* We get struct in6_addr */ 61#include <linux/ipv6.h> 62#include <asm/param.h> /* We get MAXHOSTNAMELEN. */ 63#include <linux/atomic.h> /* This gets us atomic counters. */ 64#include <linux/skbuff.h> /* We need sk_buff_head. */ 65#include <linux/workqueue.h> /* We need tq_struct. */ 66#include <linux/sctp.h> /* We need sctp* header structs. */ 67#include <net/sctp/auth.h> /* We need auth specific structs */ 68 69/* A convenience structure for handling sockaddr structures. 70 * We should wean ourselves off this. 71 */ 72union sctp_addr { 73 struct sockaddr_in v4; 74 struct sockaddr_in6 v6; 75 struct sockaddr sa; 76}; 77 78/* Forward declarations for data structures. */ 79struct sctp_globals; 80struct sctp_endpoint; 81struct sctp_association; 82struct sctp_transport; 83struct sctp_packet; 84struct sctp_chunk; 85struct sctp_inq; 86struct sctp_outq; 87struct sctp_bind_addr; 88struct sctp_ulpq; 89struct sctp_ep_common; 90struct sctp_ssnmap; 91struct crypto_hash; 92 93 94#include <net/sctp/tsnmap.h> 95#include <net/sctp/ulpevent.h> 96#include <net/sctp/ulpqueue.h> 97 98/* Structures useful for managing bind/connect. */ 99 100struct sctp_bind_bucket { 101 unsigned short port; 102 unsigned short fastreuse; 103 struct hlist_node node; 104 struct hlist_head owner; 105 struct net *net; 106}; 107 108struct sctp_bind_hashbucket { 109 spinlock_t lock; 110 struct hlist_head chain; 111}; 112 113/* Used for hashing all associations. */ 114struct sctp_hashbucket { 115 rwlock_t lock; 116 struct hlist_head chain; 117} __attribute__((__aligned__(8))); 118 119 120/* The SCTP globals structure. */ 121extern struct sctp_globals { 122 /* The following variables are implementation specific. */ 123 124 /* Default initialization values to be applied to new associations. */ 125 __u16 max_instreams; 126 __u16 max_outstreams; 127 128 /* This is a list of groups of functions for each address 129 * family that we support. 130 */ 131 struct list_head address_families; 132 133 /* This is the hash of all endpoints. */ 134 int ep_hashsize; 135 struct sctp_hashbucket *ep_hashtable; 136 137 /* This is the hash of all associations. */ 138 int assoc_hashsize; 139 struct sctp_hashbucket *assoc_hashtable; 140 141 /* This is the sctp port control hash. */ 142 int port_hashsize; 143 struct sctp_bind_hashbucket *port_hashtable; 144 145 /* Flag to indicate whether computing and verifying checksum 146 * is disabled. */ 147 bool checksum_disable; 148} sctp_globals; 149 150#define sctp_max_instreams (sctp_globals.max_instreams) 151#define sctp_max_outstreams (sctp_globals.max_outstreams) 152#define sctp_address_families (sctp_globals.address_families) 153#define sctp_ep_hashsize (sctp_globals.ep_hashsize) 154#define sctp_ep_hashtable (sctp_globals.ep_hashtable) 155#define sctp_assoc_hashsize (sctp_globals.assoc_hashsize) 156#define sctp_assoc_hashtable (sctp_globals.assoc_hashtable) 157#define sctp_port_hashsize (sctp_globals.port_hashsize) 158#define sctp_port_hashtable (sctp_globals.port_hashtable) 159#define sctp_checksum_disable (sctp_globals.checksum_disable) 160 161/* SCTP Socket type: UDP or TCP style. */ 162typedef enum { 163 SCTP_SOCKET_UDP = 0, 164 SCTP_SOCKET_UDP_HIGH_BANDWIDTH, 165 SCTP_SOCKET_TCP 166} sctp_socket_type_t; 167 168/* Per socket SCTP information. */ 169struct sctp_sock { 170 /* inet_sock has to be the first member of sctp_sock */ 171 struct inet_sock inet; 172 /* What kind of a socket is this? */ 173 sctp_socket_type_t type; 174 175 /* PF_ family specific functions. */ 176 struct sctp_pf *pf; 177 178 /* Access to HMAC transform. */ 179 struct crypto_hash *hmac; 180 char *sctp_hmac_alg; 181 182 /* What is our base endpointer? */ 183 struct sctp_endpoint *ep; 184 185 struct sctp_bind_bucket *bind_hash; 186 /* Various Socket Options. */ 187 __u16 default_stream; 188 __u32 default_ppid; 189 __u16 default_flags; 190 __u32 default_context; 191 __u32 default_timetolive; 192 __u32 default_rcv_context; 193 int max_burst; 194 195 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 196 * the destination address every heartbeat interval. This value 197 * will be inherited by all new associations. 198 */ 199 __u32 hbinterval; 200 201 /* This is the max_retrans value for new associations. */ 202 __u16 pathmaxrxt; 203 204 /* The initial Path MTU to use for new associations. */ 205 __u32 pathmtu; 206 207 /* The default SACK delay timeout for new associations. */ 208 __u32 sackdelay; 209 __u32 sackfreq; 210 211 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ 212 __u32 param_flags; 213 214 struct sctp_initmsg initmsg; 215 struct sctp_rtoinfo rtoinfo; 216 struct sctp_paddrparams paddrparam; 217 struct sctp_event_subscribe subscribe; 218 struct sctp_assocparams assocparams; 219 int user_frag; 220 __u32 autoclose; 221 __u8 nodelay; 222 __u8 disable_fragments; 223 __u8 v4mapped; 224 __u8 frag_interleave; 225 __u32 adaptation_ind; 226 __u32 pd_point; 227 228 atomic_t pd_mode; 229 /* Receive to here while partial delivery is in effect. */ 230 struct sk_buff_head pd_lobby; 231 struct list_head auto_asconf_list; 232 int do_auto_asconf; 233}; 234 235static inline struct sctp_sock *sctp_sk(const struct sock *sk) 236{ 237 return (struct sctp_sock *)sk; 238} 239 240static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp) 241{ 242 return (struct sock *)sp; 243} 244 245#if IS_ENABLED(CONFIG_IPV6) 246struct sctp6_sock { 247 struct sctp_sock sctp; 248 struct ipv6_pinfo inet6; 249}; 250#endif /* CONFIG_IPV6 */ 251 252 253/* This is our APPLICATION-SPECIFIC state cookie. 254 * THIS IS NOT DICTATED BY THE SPECIFICATION. 255 */ 256/* These are the parts of an association which we send in the cookie. 257 * Most of these are straight out of: 258 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB) 259 * 260 */ 261 262struct sctp_cookie { 263 264 /* My : Tag expected in every inbound packet and sent 265 * Verification: in the INIT or INIT ACK chunk. 266 * Tag : 267 */ 268 __u32 my_vtag; 269 270 /* Peer's : Tag expected in every outbound packet except 271 * Verification: in the INIT chunk. 272 * Tag : 273 */ 274 __u32 peer_vtag; 275 276 /* The rest of these are not from the spec, but really need to 277 * be in the cookie. 278 */ 279 280 /* My Tie Tag : Assist in discovering a restarting association. */ 281 __u32 my_ttag; 282 283 /* Peer's Tie Tag: Assist in discovering a restarting association. */ 284 __u32 peer_ttag; 285 286 /* When does this cookie expire? */ 287 ktime_t expiration; 288 289 /* Number of inbound/outbound streams which are set 290 * and negotiated during the INIT process. 291 */ 292 __u16 sinit_num_ostreams; 293 __u16 sinit_max_instreams; 294 295 /* This is the first sequence number I used. */ 296 __u32 initial_tsn; 297 298 /* This holds the originating address of the INIT packet. */ 299 union sctp_addr peer_addr; 300 301 /* IG Section 2.35.3 302 * Include the source port of the INIT-ACK 303 */ 304 __u16 my_port; 305 306 __u8 prsctp_capable; 307 308 /* Padding for future use */ 309 __u8 padding; 310 311 __u32 adaptation_ind; 312 313 __u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH]; 314 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2]; 315 __u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS]; 316 317 /* This is a shim for my peer's INIT packet, followed by 318 * a copy of the raw address list of the association. 319 * The length of the raw address list is saved in the 320 * raw_addr_list_len field, which will be used at the time when 321 * the association TCB is re-constructed from the cookie. 322 */ 323 __u32 raw_addr_list_len; 324 struct sctp_init_chunk peer_init[0]; 325}; 326 327 328/* The format of our cookie that we send to our peer. */ 329struct sctp_signed_cookie { 330 __u8 signature[SCTP_SECRET_SIZE]; 331 __u32 __pad; /* force sctp_cookie alignment to 64 bits */ 332 struct sctp_cookie c; 333} __packed; 334 335/* This is another convenience type to allocate memory for address 336 * params for the maximum size and pass such structures around 337 * internally. 338 */ 339union sctp_addr_param { 340 struct sctp_paramhdr p; 341 struct sctp_ipv4addr_param v4; 342 struct sctp_ipv6addr_param v6; 343}; 344 345/* A convenience type to allow walking through the various 346 * parameters and avoid casting all over the place. 347 */ 348union sctp_params { 349 void *v; 350 struct sctp_paramhdr *p; 351 struct sctp_cookie_preserve_param *life; 352 struct sctp_hostname_param *dns; 353 struct sctp_cookie_param *cookie; 354 struct sctp_supported_addrs_param *sat; 355 struct sctp_ipv4addr_param *v4; 356 struct sctp_ipv6addr_param *v6; 357 union sctp_addr_param *addr; 358 struct sctp_adaptation_ind_param *aind; 359 struct sctp_supported_ext_param *ext; 360 struct sctp_random_param *random; 361 struct sctp_chunks_param *chunks; 362 struct sctp_hmac_algo_param *hmac_algo; 363 struct sctp_addip_param *addip; 364}; 365 366/* RFC 2960. Section 3.3.5 Heartbeat. 367 * Heartbeat Information: variable length 368 * The Sender-specific Heartbeat Info field should normally include 369 * information about the sender's current time when this HEARTBEAT 370 * chunk is sent and the destination transport address to which this 371 * HEARTBEAT is sent (see Section 8.3). 372 */ 373typedef struct sctp_sender_hb_info { 374 struct sctp_paramhdr param_hdr; 375 union sctp_addr daddr; 376 unsigned long sent_at; 377 __u64 hb_nonce; 378} __packed sctp_sender_hb_info_t; 379 380/* 381 * RFC 2960 1.3.2 Sequenced Delivery within Streams 382 * 383 * The term "stream" is used in SCTP to refer to a sequence of user 384 * messages that are to be delivered to the upper-layer protocol in 385 * order with respect to other messages within the same stream. This is 386 * in contrast to its usage in TCP, where it refers to a sequence of 387 * bytes (in this document a byte is assumed to be eight bits). 388 * ... 389 * 390 * This is the structure we use to track both our outbound and inbound 391 * SSN, or Stream Sequence Numbers. 392 */ 393 394struct sctp_stream { 395 __u16 *ssn; 396 unsigned int len; 397}; 398 399struct sctp_ssnmap { 400 struct sctp_stream in; 401 struct sctp_stream out; 402}; 403 404struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, 405 gfp_t gfp); 406void sctp_ssnmap_free(struct sctp_ssnmap *map); 407void sctp_ssnmap_clear(struct sctp_ssnmap *map); 408 409/* What is the current SSN number for this stream? */ 410static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id) 411{ 412 return stream->ssn[id]; 413} 414 415/* Return the next SSN number for this stream. */ 416static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id) 417{ 418 return stream->ssn[id]++; 419} 420 421/* Skip over this ssn and all below. */ 422static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, 423 __u16 ssn) 424{ 425 stream->ssn[id] = ssn+1; 426} 427 428/* 429 * Pointers to address related SCTP functions. 430 * (i.e. things that depend on the address family.) 431 */ 432struct sctp_af { 433 int (*sctp_xmit) (struct sk_buff *skb, 434 struct sctp_transport *); 435 int (*setsockopt) (struct sock *sk, 436 int level, 437 int optname, 438 char __user *optval, 439 unsigned int optlen); 440 int (*getsockopt) (struct sock *sk, 441 int level, 442 int optname, 443 char __user *optval, 444 int __user *optlen); 445 int (*compat_setsockopt) (struct sock *sk, 446 int level, 447 int optname, 448 char __user *optval, 449 unsigned int optlen); 450 int (*compat_getsockopt) (struct sock *sk, 451 int level, 452 int optname, 453 char __user *optval, 454 int __user *optlen); 455 void (*get_dst) (struct sctp_transport *t, 456 union sctp_addr *saddr, 457 struct flowi *fl, 458 struct sock *sk); 459 void (*get_saddr) (struct sctp_sock *sk, 460 struct sctp_transport *t, 461 struct flowi *fl); 462 void (*copy_addrlist) (struct list_head *, 463 struct net_device *); 464 int (*cmp_addr) (const union sctp_addr *addr1, 465 const union sctp_addr *addr2); 466 void (*addr_copy) (union sctp_addr *dst, 467 union sctp_addr *src); 468 void (*from_skb) (union sctp_addr *, 469 struct sk_buff *skb, 470 int saddr); 471 void (*from_sk) (union sctp_addr *, 472 struct sock *sk); 473 void (*to_sk_saddr) (union sctp_addr *, 474 struct sock *sk); 475 void (*to_sk_daddr) (union sctp_addr *, 476 struct sock *sk); 477 void (*from_addr_param) (union sctp_addr *, 478 union sctp_addr_param *, 479 __be16 port, int iif); 480 int (*to_addr_param) (const union sctp_addr *, 481 union sctp_addr_param *); 482 int (*addr_valid) (union sctp_addr *, 483 struct sctp_sock *, 484 const struct sk_buff *); 485 sctp_scope_t (*scope) (union sctp_addr *); 486 void (*inaddr_any) (union sctp_addr *, __be16); 487 int (*is_any) (const union sctp_addr *); 488 int (*available) (union sctp_addr *, 489 struct sctp_sock *); 490 int (*skb_iif) (const struct sk_buff *sk); 491 int (*is_ce) (const struct sk_buff *sk); 492 void (*seq_dump_addr)(struct seq_file *seq, 493 union sctp_addr *addr); 494 void (*ecn_capable)(struct sock *sk); 495 __u16 net_header_len; 496 int sockaddr_len; 497 sa_family_t sa_family; 498 struct list_head list; 499}; 500 501struct sctp_af *sctp_get_af_specific(sa_family_t); 502int sctp_register_af(struct sctp_af *); 503 504/* Protocol family functions. */ 505struct sctp_pf { 506 void (*event_msgname)(struct sctp_ulpevent *, char *, int *); 507 void (*skb_msgname) (struct sk_buff *, char *, int *); 508 int (*af_supported) (sa_family_t, struct sctp_sock *); 509 int (*cmp_addr) (const union sctp_addr *, 510 const union sctp_addr *, 511 struct sctp_sock *); 512 int (*bind_verify) (struct sctp_sock *, union sctp_addr *); 513 int (*send_verify) (struct sctp_sock *, union sctp_addr *); 514 int (*supported_addrs)(const struct sctp_sock *, __be16 *); 515 struct sock *(*create_accept_sk) (struct sock *sk, 516 struct sctp_association *asoc); 517 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *); 518 struct sctp_af *af; 519}; 520 521 522/* Structure to track chunk fragments that have been acked, but peer 523 * fragments of the same message have not. 524 */ 525struct sctp_datamsg { 526 /* Chunks waiting to be submitted to lower layer. */ 527 struct list_head chunks; 528 /* Reference counting. */ 529 atomic_t refcnt; 530 /* When is this message no longer interesting to the peer? */ 531 unsigned long expires_at; 532 /* Did the messenge fail to send? */ 533 int send_error; 534 u8 send_failed:1, 535 can_abandon:1, /* can chunks from this message can be abandoned. */ 536 can_delay; /* should this message be Nagle delayed */ 537}; 538 539struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, 540 struct sctp_sndrcvinfo *, 541 struct msghdr *, int len); 542void sctp_datamsg_free(struct sctp_datamsg *); 543void sctp_datamsg_put(struct sctp_datamsg *); 544void sctp_chunk_fail(struct sctp_chunk *, int error); 545int sctp_chunk_abandoned(struct sctp_chunk *); 546 547/* RFC2960 1.4 Key Terms 548 * 549 * o Chunk: A unit of information within an SCTP packet, consisting of 550 * a chunk header and chunk-specific content. 551 * 552 * As a matter of convenience, we remember the SCTP common header for 553 * each chunk as well as a few other header pointers... 554 */ 555struct sctp_chunk { 556 struct list_head list; 557 558 atomic_t refcnt; 559 560 /* This is our link to the per-transport transmitted list. */ 561 struct list_head transmitted_list; 562 563 /* This field is used by chunks that hold fragmented data. 564 * For the first fragment this is the list that holds the rest of 565 * fragments. For the remaining fragments, this is the link to the 566 * frag_list maintained in the first fragment. 567 */ 568 struct list_head frag_list; 569 570 /* This points to the sk_buff containing the actual data. */ 571 struct sk_buff *skb; 572 573 /* These are the SCTP headers by reverse order in a packet. 574 * Note that some of these may happen more than once. In that 575 * case, we point at the "current" one, whatever that means 576 * for that level of header. 577 */ 578 579 /* We point this at the FIRST TLV parameter to chunk_hdr. */ 580 union sctp_params param_hdr; 581 union { 582 __u8 *v; 583 struct sctp_datahdr *data_hdr; 584 struct sctp_inithdr *init_hdr; 585 struct sctp_sackhdr *sack_hdr; 586 struct sctp_heartbeathdr *hb_hdr; 587 struct sctp_sender_hb_info *hbs_hdr; 588 struct sctp_shutdownhdr *shutdown_hdr; 589 struct sctp_signed_cookie *cookie_hdr; 590 struct sctp_ecnehdr *ecne_hdr; 591 struct sctp_cwrhdr *ecn_cwr_hdr; 592 struct sctp_errhdr *err_hdr; 593 struct sctp_addiphdr *addip_hdr; 594 struct sctp_fwdtsn_hdr *fwdtsn_hdr; 595 struct sctp_authhdr *auth_hdr; 596 } subh; 597 598 __u8 *chunk_end; 599 600 struct sctp_chunkhdr *chunk_hdr; 601 struct sctphdr *sctp_hdr; 602 603 /* This needs to be recoverable for SCTP_SEND_FAILED events. */ 604 struct sctp_sndrcvinfo sinfo; 605 606 /* Which association does this belong to? */ 607 struct sctp_association *asoc; 608 609 /* What endpoint received this chunk? */ 610 struct sctp_ep_common *rcvr; 611 612 /* We fill this in if we are calculating RTT. */ 613 unsigned long sent_at; 614 615 /* What is the origin IP address for this chunk? */ 616 union sctp_addr source; 617 /* Destination address for this chunk. */ 618 union sctp_addr dest; 619 620 /* For outbound message, track all fragments for SEND_FAILED. */ 621 struct sctp_datamsg *msg; 622 623 /* For an inbound chunk, this tells us where it came from. 624 * For an outbound chunk, it tells us where we'd like it to 625 * go. It is NULL if we have no preference. 626 */ 627 struct sctp_transport *transport; 628 629 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO 630 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH 631 * spec violates the principle premis that all chunks are processed 632 * in order. 633 */ 634 struct sk_buff *auth_chunk; 635 636#define SCTP_CAN_FRTX 0x0 637#define SCTP_NEED_FRTX 0x1 638#define SCTP_DONT_FRTX 0x2 639 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */ 640 has_tsn:1, /* Does this chunk have a TSN yet? */ 641 has_ssn:1, /* Does this chunk have a SSN yet? */ 642 singleton:1, /* Only chunk in the packet? */ 643 end_of_packet:1, /* Last chunk in the packet? */ 644 ecn_ce_done:1, /* Have we processed the ECN CE bit? */ 645 pdiscard:1, /* Discard the whole packet now? */ 646 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */ 647 data_accepted:1, /* At least 1 chunk accepted */ 648 auth:1, /* IN: was auth'ed | OUT: needs auth */ 649 has_asconf:1, /* IN: have seen an asconf before */ 650 tsn_missing_report:2, /* Data chunk missing counter. */ 651 fast_retransmit:2; /* Is this chunk fast retransmitted? */ 652}; 653 654void sctp_chunk_hold(struct sctp_chunk *); 655void sctp_chunk_put(struct sctp_chunk *); 656int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 657 struct iovec *data); 658void sctp_chunk_free(struct sctp_chunk *); 659void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); 660void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, const void *data); 661struct sctp_chunk *sctp_chunkify(struct sk_buff *, 662 const struct sctp_association *, 663 struct sock *); 664void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, 665 union sctp_addr *); 666const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); 667 668enum { 669 SCTP_ADDR_NEW, /* new address added to assoc/ep */ 670 SCTP_ADDR_SRC, /* address can be used as source */ 671 SCTP_ADDR_DEL, /* address about to be deleted */ 672}; 673 674/* This is a structure for holding either an IPv6 or an IPv4 address. */ 675struct sctp_sockaddr_entry { 676 struct list_head list; 677 struct rcu_head rcu; 678 union sctp_addr a; 679 __u8 state; 680 __u8 valid; 681}; 682 683#define SCTP_ADDRESS_TICK_DELAY 500 684 685typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *); 686 687/* This structure holds lists of chunks as we are assembling for 688 * transmission. 689 */ 690struct sctp_packet { 691 /* These are the SCTP header values (host order) for the packet. */ 692 __u16 source_port; 693 __u16 destination_port; 694 __u32 vtag; 695 696 /* This contains the payload chunks. */ 697 struct list_head chunk_list; 698 699 /* This is the overhead of the sctp and ip headers. */ 700 size_t overhead; 701 /* This is the total size of all chunks INCLUDING padding. */ 702 size_t size; 703 704 /* The packet is destined for this transport address. 705 * The function we finally use to pass down to the next lower 706 * layer lives in the transport structure. 707 */ 708 struct sctp_transport *transport; 709 710 /* pointer to the auth chunk for this packet */ 711 struct sctp_chunk *auth; 712 713 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */ 714 has_sack:1, /* This packet contains a SACK chunk. */ 715 has_auth:1, /* This packet contains an AUTH chunk */ 716 has_data:1, /* This packet contains at least 1 DATA chunk */ 717 ipfragok:1; /* So let ip fragment this packet */ 718}; 719 720struct sctp_packet *sctp_packet_init(struct sctp_packet *, 721 struct sctp_transport *, 722 __u16 sport, __u16 dport); 723struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int); 724sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *, 725 struct sctp_chunk *, int); 726sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *, 727 struct sctp_chunk *); 728int sctp_packet_transmit(struct sctp_packet *); 729void sctp_packet_free(struct sctp_packet *); 730 731static inline int sctp_packet_empty(struct sctp_packet *packet) 732{ 733 return packet->size == packet->overhead; 734} 735 736/* This represents a remote transport address. 737 * For local transport addresses, we just use union sctp_addr. 738 * 739 * RFC2960 Section 1.4 Key Terms 740 * 741 * o Transport address: A Transport Address is traditionally defined 742 * by Network Layer address, Transport Layer protocol and Transport 743 * Layer port number. In the case of SCTP running over IP, a 744 * transport address is defined by the combination of an IP address 745 * and an SCTP port number (where SCTP is the Transport protocol). 746 * 747 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control 748 * 749 * o The sender keeps a separate congestion control parameter set for 750 * each of the destination addresses it can send to (not each 751 * source-destination pair but for each destination). The parameters 752 * should decay if the address is not used for a long enough time 753 * period. 754 * 755 */ 756struct sctp_transport { 757 /* A list of transports. */ 758 struct list_head transports; 759 760 /* Reference counting. */ 761 atomic_t refcnt; 762 __u32 dead:1, 763 /* RTO-Pending : A flag used to track if one of the DATA 764 * chunks sent to this address is currently being 765 * used to compute a RTT. If this flag is 0, 766 * the next DATA chunk sent to this destination 767 * should be used to compute a RTT and this flag 768 * should be set. Every time the RTT 769 * calculation completes (i.e. the DATA chunk 770 * is SACK'd) clear this flag. 771 */ 772 rto_pending:1, 773 774 /* 775 * hb_sent : a flag that signals that we have a pending 776 * heartbeat. 777 */ 778 hb_sent:1, 779 780 /* Is the Path MTU update pending on this tranport */ 781 pmtu_pending:1; 782 783 /* Has this transport moved the ctsn since we last sacked */ 784 __u32 sack_generation; 785 786 struct flowi fl; 787 788 /* This is the peer's IP address and port. */ 789 union sctp_addr ipaddr; 790 791 /* These are the functions we call to handle LLP stuff. */ 792 struct sctp_af *af_specific; 793 794 /* Which association do we belong to? */ 795 struct sctp_association *asoc; 796 797 /* RFC2960 798 * 799 * 12.3 Per Transport Address Data 800 * 801 * For each destination transport address in the peer's 802 * address list derived from the INIT or INIT ACK chunk, a 803 * number of data elements needs to be maintained including: 804 */ 805 /* RTO : The current retransmission timeout value. */ 806 unsigned long rto; 807 808 __u32 rtt; /* This is the most recent RTT. */ 809 810 /* RTTVAR : The current RTT variation. */ 811 __u32 rttvar; 812 813 /* SRTT : The current smoothed round trip time. */ 814 __u32 srtt; 815 816 /* 817 * These are the congestion stats. 818 */ 819 /* cwnd : The current congestion window. */ 820 __u32 cwnd; /* This is the actual cwnd. */ 821 822 /* ssthresh : The current slow start threshold value. */ 823 __u32 ssthresh; 824 825 /* partial : The tracking method for increase of cwnd when in 826 * bytes acked : congestion avoidance mode (see Section 6.2.2) 827 */ 828 __u32 partial_bytes_acked; 829 830 /* Data that has been sent, but not acknowledged. */ 831 __u32 flight_size; 832 833 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */ 834 835 /* Destination */ 836 struct dst_entry *dst; 837 /* Source address. */ 838 union sctp_addr saddr; 839 840 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 841 * the destination address every heartbeat interval. 842 */ 843 unsigned long hbinterval; 844 845 /* SACK delay timeout */ 846 unsigned long sackdelay; 847 __u32 sackfreq; 848 849 /* When was the last time (in jiffies) that we heard from this 850 * transport? We use this to pick new active and retran paths. 851 */ 852 unsigned long last_time_heard; 853 854 /* Last time(in jiffies) when cwnd is reduced due to the congestion 855 * indication based on ECNE chunk. 856 */ 857 unsigned long last_time_ecne_reduced; 858 859 /* This is the max_retrans value for the transport and will 860 * be initialized from the assocs value. This can be changed 861 * using the SCTP_SET_PEER_ADDR_PARAMS socket option. 862 */ 863 __u16 pathmaxrxt; 864 865 /* This is the partially failed retrans value for the transport 866 * and will be initialized from the assocs value. This can be changed 867 * using the SCTP_PEER_ADDR_THLDS socket option 868 */ 869 int pf_retrans; 870 /* PMTU : The current known path MTU. */ 871 __u32 pathmtu; 872 873 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ 874 __u32 param_flags; 875 876 /* The number of times INIT has been sent on this transport. */ 877 int init_sent_count; 878 879 /* state : The current state of this destination, 880 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN. 881 */ 882 int state; 883 884 /* These are the error stats for this destination. */ 885 886 /* Error count : The current error count for this destination. */ 887 unsigned short error_count; 888 889 /* Per : A timer used by each destination. 890 * Destination : 891 * Timer : 892 * 893 * [Everywhere else in the text this is called T3-rtx. -ed] 894 */ 895 struct timer_list T3_rtx_timer; 896 897 /* Heartbeat timer is per destination. */ 898 struct timer_list hb_timer; 899 900 /* Timer to handle ICMP proto unreachable envets */ 901 struct timer_list proto_unreach_timer; 902 903 /* Since we're using per-destination retransmission timers 904 * (see above), we're also using per-destination "transmitted" 905 * queues. This probably ought to be a private struct 906 * accessible only within the outqueue, but it's not, yet. 907 */ 908 struct list_head transmitted; 909 910 /* We build bundle-able packets for this transport here. */ 911 struct sctp_packet packet; 912 913 /* This is the list of transports that have chunks to send. */ 914 struct list_head send_ready; 915 916 /* State information saved for SFR_CACC algorithm. The key 917 * idea in SFR_CACC is to maintain state at the sender on a 918 * per-destination basis when a changeover happens. 919 * char changeover_active; 920 * char cycling_changeover; 921 * __u32 next_tsn_at_change; 922 * char cacc_saw_newack; 923 */ 924 struct { 925 /* An unsigned integer, which stores the next TSN to be 926 * used by the sender, at the moment of changeover. 927 */ 928 __u32 next_tsn_at_change; 929 930 /* A flag which indicates the occurrence of a changeover */ 931 char changeover_active; 932 933 /* A flag which indicates whether the change of primary is 934 * the first switch to this destination address during an 935 * active switch. 936 */ 937 char cycling_changeover; 938 939 /* A temporary flag, which is used during the processing of 940 * a SACK to estimate the causative TSN(s)'s group. 941 */ 942 char cacc_saw_newack; 943 } cacc; 944 945 /* 64-bit random number sent with heartbeat. */ 946 __u64 hb_nonce; 947 948 struct rcu_head rcu; 949}; 950 951struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *, 952 gfp_t); 953void sctp_transport_set_owner(struct sctp_transport *, 954 struct sctp_association *); 955void sctp_transport_route(struct sctp_transport *, union sctp_addr *, 956 struct sctp_sock *); 957void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk); 958void sctp_transport_free(struct sctp_transport *); 959void sctp_transport_reset_timers(struct sctp_transport *); 960void sctp_transport_hold(struct sctp_transport *); 961void sctp_transport_put(struct sctp_transport *); 962void sctp_transport_update_rto(struct sctp_transport *, __u32); 963void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32); 964void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t); 965void sctp_transport_burst_limited(struct sctp_transport *); 966void sctp_transport_burst_reset(struct sctp_transport *); 967unsigned long sctp_transport_timeout(struct sctp_transport *); 968void sctp_transport_reset(struct sctp_transport *); 969void sctp_transport_update_pmtu(struct sock *, struct sctp_transport *, u32); 970void sctp_transport_immediate_rtx(struct sctp_transport *); 971 972 973/* This is the structure we use to queue packets as they come into 974 * SCTP. We write packets to it and read chunks from it. 975 */ 976struct sctp_inq { 977 /* This is actually a queue of sctp_chunk each 978 * containing a partially decoded packet. 979 */ 980 struct list_head in_chunk_list; 981 /* This is the packet which is currently off the in queue and is 982 * being worked on through the inbound chunk processing. 983 */ 984 struct sctp_chunk *in_progress; 985 986 /* This is the delayed task to finish delivering inbound 987 * messages. 988 */ 989 struct work_struct immediate; 990}; 991 992void sctp_inq_init(struct sctp_inq *); 993void sctp_inq_free(struct sctp_inq *); 994void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet); 995struct sctp_chunk *sctp_inq_pop(struct sctp_inq *); 996struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *); 997void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t); 998 999/* This is the structure we use to hold outbound chunks. You push 1000 * chunks in and they automatically pop out the other end as bundled
1001 * packets (it calls (*output_handler)()). 1002 * 1003 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1, 1004 * and 8.2 of the v13 draft. 1005 * 1006 * It handles retransmissions. The connection to the timeout portion 1007 * of the state machine is through sctp_..._timeout() and timeout_handler. 1008 * 1009 * If you feed it SACKs, it will eat them. 1010 * 1011 * If you give it big chunks, it will fragment them. 1012 * 1013 * It assigns TSN's to data chunks. This happens at the last possible 1014 * instant before transmission. 1015 * 1016 * When free()'d, it empties itself out via output_handler(). 1017 */ 1018struct sctp_outq { 1019 struct sctp_association *asoc; 1020 1021 /* Data pending that has never been transmitted. */ 1022 struct list_head out_chunk_list; 1023 1024 unsigned int out_qlen; /* Total length of queued data chunks. */ 1025 1026 /* Error of send failed, may used in SCTP_SEND_FAILED event. */ 1027 unsigned int error; 1028 1029 /* These are control chunks we want to send. */ 1030 struct list_head control_chunk_list; 1031 1032 /* These are chunks that have been sacked but are above the 1033 * CTSN, or cumulative tsn ack point. 1034 */ 1035 struct list_head sacked; 1036 1037 /* Put chunks on this list to schedule them for 1038 * retransmission. 1039 */ 1040 struct list_head retransmit; 1041 1042 /* Put chunks on this list to save them for FWD TSN processing as 1043 * they were abandoned. 1044 */ 1045 struct list_head abandoned; 1046 1047 /* How many unackd bytes do we have in-flight? */ 1048 __u32 outstanding_bytes; 1049 1050 /* Are we doing fast-rtx on this queue */ 1051 char fast_rtx; 1052 1053 /* Corked? */ 1054 char cork; 1055 1056 /* Is this structure empty? */ 1057 char empty; 1058}; 1059 1060void sctp_outq_init(struct sctp_association *, struct sctp_outq *); 1061void sctp_outq_teardown(struct sctp_outq *); 1062void sctp_outq_free(struct sctp_outq*); 1063int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk); 1064int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *); 1065int sctp_outq_is_empty(const struct sctp_outq *); 1066void sctp_outq_restart(struct sctp_outq *); 1067 1068void sctp_retransmit(struct sctp_outq *, struct sctp_transport *, 1069 sctp_retransmit_reason_t); 1070void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); 1071int sctp_outq_uncork(struct sctp_outq *); 1072/* Uncork and flush an outqueue. */ 1073static inline void sctp_outq_cork(struct sctp_outq *q) 1074{ 1075 q->cork = 1; 1076} 1077 1078/* These bind address data fields common between endpoints and associations */ 1079struct sctp_bind_addr { 1080 1081 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1082 * 1083 * SCTP Port: The local SCTP port number the endpoint is 1084 * bound to. 1085 */ 1086 __u16 port; 1087 1088 /* RFC 2960 12.1 Parameters necessary for the SCTP instance 1089 * 1090 * Address List: The list of IP addresses that this instance 1091 * has bound. This information is passed to one's 1092 * peer(s) in INIT and INIT ACK chunks. 1093 */ 1094 struct list_head address_list; 1095}; 1096 1097void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port); 1098void sctp_bind_addr_free(struct sctp_bind_addr *); 1099int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest, 1100 const struct sctp_bind_addr *src, 1101 sctp_scope_t scope, gfp_t gfp, 1102 int flags); 1103int sctp_bind_addr_dup(struct sctp_bind_addr *dest, 1104 const struct sctp_bind_addr *src, 1105 gfp_t gfp); 1106int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 1107 __u8 addr_state, gfp_t gfp); 1108int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *); 1109int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, 1110 struct sctp_sock *); 1111int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *, 1112 struct sctp_sock *, struct sctp_sock *); 1113int sctp_bind_addr_state(const struct sctp_bind_addr *bp, 1114 const union sctp_addr *addr); 1115union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 1116 const union sctp_addr *addrs, 1117 int addrcnt, 1118 struct sctp_sock *opt); 1119union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 1120 int *addrs_len, 1121 gfp_t gfp); 1122int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, 1123 __u16 port, gfp_t gfp); 1124 1125sctp_scope_t sctp_scope(const union sctp_addr *); 1126int sctp_in_scope(struct net *net, const union sctp_addr *addr, const sctp_scope_t scope); 1127int sctp_is_any(struct sock *sk, const union sctp_addr *addr); 1128int sctp_addr_is_valid(const union sctp_addr *addr); 1129int sctp_is_ep_boundall(struct sock *sk); 1130 1131 1132/* What type of endpoint? */ 1133typedef enum { 1134 SCTP_EP_TYPE_SOCKET, 1135 SCTP_EP_TYPE_ASSOCIATION, 1136} sctp_endpoint_type_t; 1137 1138/* 1139 * A common base class to bridge the implmentation view of a 1140 * socket (usually listening) endpoint versus an association's 1141 * local endpoint. 1142 * This common structure is useful for several purposes: 1143 * 1) Common interface for lookup routines. 1144 * a) Subfunctions work for either endpoint or association 1145 * b) Single interface to lookup allows hiding the lookup lock rather 1146 * than acquiring it externally. 1147 * 2) Common interface for the inbound chunk handling/state machine. 1148 * 3) Common object handling routines for reference counting, etc. 1149 * 4) Disentangle association lookup from endpoint lookup, where we 1150 * do not have to find our endpoint to find our association. 1151 * 1152 */ 1153 1154struct sctp_ep_common { 1155 /* Fields to help us manage our entries in the hash tables. */ 1156 struct hlist_node node; 1157 int hashent; 1158 1159 /* Runtime type information. What kind of endpoint is this? */ 1160 sctp_endpoint_type_t type; 1161 1162 /* Some fields to help us manage this object. 1163 * refcnt - Reference count access to this object. 1164 * dead - Do not attempt to use this object. 1165 */ 1166 atomic_t refcnt; 1167 bool dead; 1168 1169 /* What socket does this endpoint belong to? */ 1170 struct sock *sk; 1171 1172 /* This is where we receive inbound chunks. */ 1173 struct sctp_inq inqueue; 1174 1175 /* This substructure includes the defining parameters of the 1176 * endpoint: 1177 * bind_addr.port is our shared port number. 1178 * bind_addr.address_list is our set of local IP addresses. 1179 */ 1180 struct sctp_bind_addr bind_addr; 1181}; 1182 1183 1184/* RFC Section 1.4 Key Terms 1185 * 1186 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a 1187 * multi-homed host, an SCTP endpoint is represented to its peers as a 1188 * combination of a set of eligible destination transport addresses to 1189 * which SCTP packets can be sent and a set of eligible source 1190 * transport addresses from which SCTP packets can be received. 1191 * All transport addresses used by an SCTP endpoint must use the 1192 * same port number, but can use multiple IP addresses. A transport 1193 * address used by an SCTP endpoint must not be used by another 1194 * SCTP endpoint. In other words, a transport address is unique 1195 * to an SCTP endpoint. 1196 * 1197 * From an implementation perspective, each socket has one of these. 1198 * A TCP-style socket will have exactly one association on one of 1199 * these. An UDP-style socket will have multiple associations hanging 1200 * off one of these. 1201 */ 1202 1203struct sctp_endpoint { 1204 /* Common substructure for endpoint and association. */ 1205 struct sctp_ep_common base; 1206 1207 /* Associations: A list of current associations and mappings 1208 * to the data consumers for each association. This 1209 * may be in the form of a hash table or other 1210 * implementation dependent structure. The data 1211 * consumers may be process identification 1212 * information such as file descriptors, named pipe 1213 * pointer, or table pointers dependent on how SCTP 1214 * is implemented. 1215 */ 1216 /* This is really a list of struct sctp_association entries. */ 1217 struct list_head asocs; 1218 1219 /* Secret Key: A secret key used by this endpoint to compute 1220 * the MAC. This SHOULD be a cryptographic quality 1221 * random number with a sufficient length. 1222 * Discussion in [RFC1750] can be helpful in 1223 * selection of the key. 1224 */ 1225 __u8 secret_key[SCTP_SECRET_SIZE]; 1226 1227 /* digest: This is a digest of the sctp cookie. This field is 1228 * only used on the receive path when we try to validate 1229 * that the cookie has not been tampered with. We put 1230 * this here so we pre-allocate this once and can re-use 1231 * on every receive. 1232 */ 1233 __u8 *digest; 1234 1235 /* sendbuf acct. policy. */ 1236 __u32 sndbuf_policy; 1237 1238 /* rcvbuf acct. policy. */ 1239 __u32 rcvbuf_policy; 1240 1241 /* SCTP AUTH: array of the HMACs that will be allocated 1242 * we need this per association so that we don't serialize 1243 */ 1244 struct crypto_hash **auth_hmacs; 1245 1246 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */ 1247 struct sctp_hmac_algo_param *auth_hmacs_list; 1248 1249 /* SCTP-AUTH: chunks to authenticate encoded into parameter */ 1250 struct sctp_chunks_param *auth_chunk_list; 1251 1252 /* SCTP-AUTH: endpoint shared keys */ 1253 struct list_head endpoint_shared_keys; 1254 __u16 active_key_id; 1255}; 1256 1257/* Recover the outter endpoint structure. */ 1258static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) 1259{ 1260 struct sctp_endpoint *ep; 1261 1262 ep = container_of(base, struct sctp_endpoint, base); 1263 return ep; 1264} 1265 1266/* These are function signatures for manipulating endpoints. */ 1267struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t); 1268void sctp_endpoint_free(struct sctp_endpoint *); 1269void sctp_endpoint_put(struct sctp_endpoint *); 1270void sctp_endpoint_hold(struct sctp_endpoint *); 1271void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); 1272struct sctp_association *sctp_endpoint_lookup_assoc( 1273 const struct sctp_endpoint *ep, 1274 const union sctp_addr *paddr, 1275 struct sctp_transport **); 1276int sctp_endpoint_is_peeled_off(struct sctp_endpoint *, 1277 const union sctp_addr *); 1278struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *, 1279 struct net *, const union sctp_addr *); 1280int sctp_has_association(struct net *net, const union sctp_addr *laddr, 1281 const union sctp_addr *paddr); 1282 1283int sctp_verify_init(struct net *net, const struct sctp_association *asoc, 1284 sctp_cid_t, sctp_init_chunk_t *peer_init, 1285 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk); 1286int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk, 1287 const union sctp_addr *peer, 1288 sctp_init_chunk_t *init, gfp_t gfp); 1289__u32 sctp_generate_tag(const struct sctp_endpoint *); 1290__u32 sctp_generate_tsn(const struct sctp_endpoint *); 1291 1292struct sctp_inithdr_host { 1293 __u32 init_tag; 1294 __u32 a_rwnd; 1295 __u16 num_outbound_streams; 1296 __u16 num_inbound_streams; 1297 __u32 initial_tsn; 1298}; 1299 1300/* SCTP_GET_ASSOC_STATS counters */ 1301struct sctp_priv_assoc_stats { 1302 /* Maximum observed rto in the association during subsequent 1303 * observations. Value is set to 0 if no RTO measurement took place 1304 * The transport where the max_rto was observed is returned in 1305 * obs_rto_ipaddr 1306 */ 1307 struct sockaddr_storage obs_rto_ipaddr; 1308 __u64 max_obs_rto; 1309 /* Total In and Out SACKs received and sent */ 1310 __u64 isacks; 1311 __u64 osacks; 1312 /* Total In and Out packets received and sent */ 1313 __u64 opackets; 1314 __u64 ipackets; 1315 /* Total retransmitted chunks */ 1316 __u64 rtxchunks; 1317 /* TSN received > next expected */ 1318 __u64 outofseqtsns; 1319 /* Duplicate Chunks received */ 1320 __u64 idupchunks; 1321 /* Gap Ack Blocks received */ 1322 __u64 gapcnt; 1323 /* Unordered data chunks sent and received */ 1324 __u64 ouodchunks; 1325 __u64 iuodchunks; 1326 /* Ordered data chunks sent and received */ 1327 __u64 oodchunks; 1328 __u64 iodchunks; 1329 /* Control chunks sent and received */ 1330 __u64 octrlchunks; 1331 __u64 ictrlchunks; 1332}; 1333 1334/* RFC2960 1335 * 1336 * 12. Recommended Transmission Control Block (TCB) Parameters 1337 * 1338 * This section details a recommended set of parameters that should 1339 * be contained within the TCB for an implementation. This section is 1340 * for illustrative purposes and should not be deemed as requirements 1341 * on an implementation or as an exhaustive list of all parameters 1342 * inside an SCTP TCB. Each implementation may need its own additional 1343 * parameters for optimization. 1344 */ 1345 1346 1347/* Here we have information about each individual association. */ 1348struct sctp_association { 1349 1350 /* A base structure common to endpoint and association. 1351 * In this context, it represents the associations's view 1352 * of the local endpoint of the association. 1353 */ 1354 struct sctp_ep_common base; 1355 1356 /* Associations on the same socket. */ 1357 struct list_head asocs; 1358 1359 /* association id. */ 1360 sctp_assoc_t assoc_id; 1361 1362 /* This is our parent endpoint. */ 1363 struct sctp_endpoint *ep; 1364 1365 /* These are those association elements needed in the cookie. */ 1366 struct sctp_cookie c; 1367 1368 /* This is all information about our peer. */ 1369 struct { 1370 /* rwnd 1371 * 1372 * Peer Rwnd : Current calculated value of the peer's rwnd. 1373 */ 1374 __u32 rwnd; 1375 1376 /* transport_addr_list 1377 * 1378 * Peer : A list of SCTP transport addresses that the 1379 * Transport : peer is bound to. This information is derived 1380 * Address : from the INIT or INIT ACK and is used to 1381 * List : associate an inbound packet with a given 1382 * : association. Normally this information is 1383 * : hashed or keyed for quick lookup and access 1384 * : of the TCB. 1385 * : The list is also initialized with the list 1386 * : of addresses passed with the sctp_connectx() 1387 * : call. 1388 * 1389 * It is a list of SCTP_transport's. 1390 */ 1391 struct list_head transport_addr_list; 1392 1393 /* transport_count 1394 * 1395 * Peer : A count of the number of peer addresses 1396 * Transport : in the Peer Transport Address List. 1397 * Address : 1398 * Count : 1399 */ 1400 __u16 transport_count; 1401 1402 /* port 1403 * The transport layer port number. 1404 */ 1405 __u16 port; 1406 1407 /* primary_path 1408 * 1409 * Primary : This is the current primary destination 1410 * Path : transport address of the peer endpoint. It 1411 * : may also specify a source transport address 1412 * : on this endpoint. 1413 * 1414 * All of these paths live on transport_addr_list. 1415 * 1416 * At the bakeoffs, we discovered that the intent of 1417 * primaryPath is that it only changes when the ULP 1418 * asks to have it changed. We add the activePath to 1419 * designate the connection we are currently using to 1420 * transmit new data and most control chunks. 1421 */ 1422 struct sctp_transport *primary_path; 1423 1424 /* Cache the primary path address here, when we 1425 * need a an address for msg_name. 1426 */ 1427 union sctp_addr primary_addr; 1428 1429 /* active_path 1430 * The path that we are currently using to 1431 * transmit new data and most control chunks. 1432 */ 1433 struct sctp_transport *active_path; 1434 1435 /* retran_path 1436 * 1437 * RFC2960 6.4 Multi-homed SCTP Endpoints 1438 * ... 1439 * Furthermore, when its peer is multi-homed, an 1440 * endpoint SHOULD try to retransmit a chunk to an 1441 * active destination transport address that is 1442 * different from the last destination address to 1443 * which the DATA chunk was sent. 1444 */ 1445 struct sctp_transport *retran_path; 1446 1447 /* Pointer to last transport I have sent on. */ 1448 struct sctp_transport *last_sent_to; 1449 1450 /* This is the last transport I have received DATA on. */ 1451 struct sctp_transport *last_data_from; 1452 1453 /* 1454 * Mapping An array of bits or bytes indicating which out of 1455 * Array order TSN's have been received (relative to the 1456 * Last Rcvd TSN). If no gaps exist, i.e. no out of 1457 * order packets have been received, this array 1458 * will be set to all zero. This structure may be 1459 * in the form of a circular buffer or bit array. 1460 * 1461 * Last Rcvd : This is the last TSN received in 1462 * TSN : sequence. This value is set initially by 1463 * : taking the peer's Initial TSN, received in 1464 * : the INIT or INIT ACK chunk, and subtracting 1465 * : one from it. 1466 * 1467 * Throughout most of the specification this is called the 1468 * "Cumulative TSN ACK Point". In this case, we 1469 * ignore the advice in 12.2 in favour of the term 1470 * used in the bulk of the text. This value is hidden 1471 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). 1472 */ 1473 struct sctp_tsnmap tsn_map; 1474 1475 /* Ack State : This flag indicates if the next received 1476 * : packet is to be responded to with a 1477 * : SACK. This is initializedto 0. When a packet 1478 * : is received it is incremented. If this value 1479 * : reaches 2 or more, a SACK is sent and the 1480 * : value is reset to 0. Note: This is used only 1481 * : when no DATA chunks are received out of 1482 * : order. When DATA chunks are out of order, 1483 * : SACK's are not delayed (see Section 6). 1484 */ 1485 __u8 sack_needed; /* Do we need to sack the peer? */ 1486 __u32 sack_cnt; 1487 __u32 sack_generation; 1488 1489 /* These are capabilities which our peer advertised. */ 1490 __u8 ecn_capable:1, /* Can peer do ECN? */ 1491 ipv4_address:1, /* Peer understands IPv4 addresses? */ 1492 ipv6_address:1, /* Peer understands IPv6 addresses? */ 1493 hostname_address:1, /* Peer understands DNS addresses? */ 1494 asconf_capable:1, /* Does peer support ADDIP? */ 1495 prsctp_capable:1, /* Can peer do PR-SCTP? */ 1496 auth_capable:1; /* Is peer doing SCTP-AUTH? */ 1497 1498 __u32 adaptation_ind; /* Adaptation Code point. */ 1499 1500 /* This mask is used to disable sending the ASCONF chunk 1501 * with specified parameter to peer. 1502 */ 1503 __be16 addip_disabled_mask; 1504 1505 struct sctp_inithdr_host i; 1506 int cookie_len; 1507 void *cookie; 1508 1509 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. 1510 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the 1511 * Initial TSN Value minus 1 1512 */ 1513 __u32 addip_serial; 1514 1515 /* SCTP-AUTH: We need to know pears random number, hmac list 1516 * and authenticated chunk list. All that is part of the 1517 * cookie and these are just pointers to those locations 1518 */ 1519 sctp_random_param_t *peer_random; 1520 sctp_chunks_param_t *peer_chunks; 1521 sctp_hmac_algo_param_t *peer_hmacs; 1522 } peer; 1523 1524 /* State : A state variable indicating what state the 1525 * : association is in, i.e. COOKIE-WAIT, 1526 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, 1527 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. 1528 * 1529 * Note: No "CLOSED" state is illustrated since if a 1530 * association is "CLOSED" its TCB SHOULD be removed. 1531 * 1532 * In this implementation we DO have a CLOSED 1533 * state which is used during initiation and shutdown. 1534 * 1535 * State takes values from SCTP_STATE_*. 1536 */ 1537 sctp_state_t state; 1538 1539 /* The cookie life I award for any cookie. */ 1540 ktime_t cookie_life; 1541 1542 /* Overall : The overall association error count. 1543 * Error Count : [Clear this any time I get something.] 1544 */ 1545 int overall_error_count; 1546 1547 /* These are the association's initial, max, and min RTO values. 1548 * These values will be initialized by system defaults, but can 1549 * be modified via the SCTP_RTOINFO socket option. 1550 */ 1551 unsigned long rto_initial; 1552 unsigned long rto_max; 1553 unsigned long rto_min; 1554 1555 /* Maximum number of new data packets that can be sent in a burst. */ 1556 int max_burst; 1557 1558 /* This is the max_retrans value for the association. This value will 1559 * be initialized initialized from system defaults, but can be 1560 * modified by the SCTP_ASSOCINFO socket option. 1561 */ 1562 int max_retrans; 1563 1564 /* This is the partially failed retrans value for the transport 1565 * and will be initialized from the assocs value. This can be 1566 * changed using the SCTP_PEER_ADDR_THLDS socket option 1567 */ 1568 int pf_retrans; 1569 1570 /* Maximum number of times the endpoint will retransmit INIT */ 1571 __u16 max_init_attempts; 1572 1573 /* How many times have we resent an INIT? */ 1574 __u16 init_retries; 1575 1576 /* The largest timeout or RTO value to use in attempting an INIT */ 1577 unsigned long max_init_timeo; 1578 1579 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to 1580 * the destination address every heartbeat interval. This value 1581 * will be inherited by all new transports. 1582 */ 1583 unsigned long hbinterval; 1584 1585 /* This is the max_retrans value for new transports in the 1586 * association. 1587 */ 1588 __u16 pathmaxrxt; 1589 1590 /* Flag that path mtu update is pending */ 1591 __u8 pmtu_pending; 1592 1593 /* Association : The smallest PMTU discovered for all of the 1594 * PMTU : peer's transport addresses. 1595 */ 1596 __u32 pathmtu; 1597 1598 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ 1599 __u32 param_flags; 1600 1601 /* SACK delay timeout */ 1602 unsigned long sackdelay; 1603 __u32 sackfreq; 1604 1605 1606 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES]; 1607 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; 1608 1609 /* Transport to which SHUTDOWN chunk was last sent. */ 1610 struct sctp_transport *shutdown_last_sent_to; 1611 1612 /* How many times have we resent a SHUTDOWN */ 1613 int shutdown_retries; 1614 1615 /* Transport to which INIT chunk was last sent. */ 1616 struct sctp_transport *init_last_sent_to; 1617 1618 /* Next TSN : The next TSN number to be assigned to a new 1619 * : DATA chunk. This is sent in the INIT or INIT 1620 * : ACK chunk to the peer and incremented each 1621 * : time a DATA chunk is assigned a TSN 1622 * : (normally just prior to transmit or during 1623 * : fragmentation). 1624 */ 1625 __u32 next_tsn; 1626 1627 /* 1628 * Last Rcvd : This is the last TSN received in sequence. This value 1629 * TSN : is set initially by taking the peer's Initial TSN, 1630 * : received in the INIT or INIT ACK chunk, and 1631 * : subtracting one from it. 1632 * 1633 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. 1634 */ 1635 1636 __u32 ctsn_ack_point; 1637 1638 /* PR-SCTP Advanced.Peer.Ack.Point */ 1639 __u32 adv_peer_ack_point; 1640 1641 /* Highest TSN that is acknowledged by incoming SACKs. */ 1642 __u32 highest_sacked; 1643 1644 /* TSN marking the fast recovery exit point */ 1645 __u32 fast_recovery_exit; 1646 1647 /* Flag to track the current fast recovery state */ 1648 __u8 fast_recovery; 1649 1650 /* The number of unacknowledged data chunks. Reported through 1651 * the SCTP_STATUS sockopt. 1652 */ 1653 __u16 unack_data; 1654 1655 /* The total number of data chunks that we've had to retransmit 1656 * as the result of a T3 timer expiration 1657 */ 1658 __u32 rtx_data_chunks; 1659 1660 /* This is the association's receive buffer space. This value is used 1661 * to set a_rwnd field in an INIT or a SACK chunk. 1662 */ 1663 __u32 rwnd; 1664 1665 /* This is the last advertised value of rwnd over a SACK chunk. */ 1666 __u32 a_rwnd; 1667 1668 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed 1669 * to slop over a maximum of the association's frag_point. 1670 */ 1671 __u32 rwnd_over; 1672 1673 /* Keeps treack of rwnd pressure. This happens when we have 1674 * a window, but not recevie buffer (i.e small packets). This one 1675 * is releases slowly (1 PMTU at a time ). 1676 */ 1677 __u32 rwnd_press; 1678 1679 /* This is the sndbuf size in use for the association. 1680 * This corresponds to the sndbuf size for the association, 1681 * as specified in the sk->sndbuf. 1682 */ 1683 int sndbuf_used; 1684 1685 /* This is the amount of memory that this association has allocated 1686 * in the receive path at any given time. 1687 */ 1688 atomic_t rmem_alloc; 1689 1690 /* This is the wait queue head for send requests waiting on 1691 * the association sndbuf space. 1692 */ 1693 wait_queue_head_t wait; 1694 1695 /* The message size at which SCTP fragmentation will occur. */ 1696 __u32 frag_point; 1697 __u32 user_frag; 1698 1699 /* Counter used to count INIT errors. */ 1700 int init_err_counter; 1701 1702 /* Count the number of INIT cycles (for doubling timeout). */ 1703 int init_cycle; 1704 1705 /* Default send parameters. */ 1706 __u16 default_stream; 1707 __u16 default_flags; 1708 __u32 default_ppid; 1709 __u32 default_context; 1710 __u32 default_timetolive; 1711 1712 /* Default receive parameters */ 1713 __u32 default_rcv_context; 1714 1715 /* This tracks outbound ssn for a given stream. */ 1716 struct sctp_ssnmap *ssnmap; 1717 1718 /* All outbound chunks go through this structure. */ 1719 struct sctp_outq outqueue; 1720 1721 /* A smart pipe that will handle reordering and fragmentation, 1722 * as well as handle passing events up to the ULP. 1723 */ 1724 struct sctp_ulpq ulpq; 1725 1726 /* Last TSN that caused an ECNE Chunk to be sent. */ 1727 __u32 last_ecne_tsn; 1728 1729 /* Last TSN that caused a CWR Chunk to be sent. */ 1730 __u32 last_cwr_tsn; 1731 1732 /* How many duplicated TSNs have we seen? */ 1733 int numduptsns; 1734 1735 /* Number of seconds of idle time before an association is closed. 1736 * In the association context, this is really used as a boolean 1737 * since the real timeout is stored in the timeouts array 1738 */ 1739 __u32 autoclose; 1740 1741 /* These are to support 1742 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses 1743 * and Enforcement of Flow and Message Limits" 1744 * <draft-ietf-tsvwg-addip-sctp-02.txt> 1745 * or "ADDIP" for short. 1746 */ 1747 1748 1749 1750 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1751 * 1752 * R1) One and only one ASCONF Chunk MAY be in transit and 1753 * unacknowledged at any one time. If a sender, after sending 1754 * an ASCONF chunk, decides it needs to transfer another 1755 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1756 * returns from the previous ASCONF Chunk before sending a 1757 * subsequent ASCONF. Note this restriction binds each side, 1758 * so at any time two ASCONF may be in-transit on any given 1759 * association (one sent from each endpoint). 1760 * 1761 * [This is our one-and-only-one ASCONF in flight. If we do 1762 * not have an ASCONF in flight, this is NULL.] 1763 */ 1764 struct sctp_chunk *addip_last_asconf; 1765 1766 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk. 1767 * 1768 * This is needed to implement itmes E1 - E4 of the updated 1769 * spec. Here is the justification: 1770 * 1771 * Since the peer may bundle multiple ASCONF chunks toward us, 1772 * we now need the ability to cache multiple ACKs. The section 1773 * describes in detail how they are cached and cleaned up. 1774 */ 1775 struct list_head asconf_ack_list; 1776 1777 /* These ASCONF chunks are waiting to be sent. 1778 * 1779 * These chunaks can't be pushed to outqueue until receiving 1780 * ASCONF_ACK for the previous ASCONF indicated by 1781 * addip_last_asconf, so as to guarantee that only one ASCONF 1782 * is in flight at any time. 1783 * 1784 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks 1785 * 1786 * In defining the ASCONF Chunk transfer procedures, it is 1787 * essential that these transfers MUST NOT cause congestion 1788 * within the network. To achieve this, we place these 1789 * restrictions on the transfer of ASCONF Chunks: 1790 * 1791 * R1) One and only one ASCONF Chunk MAY be in transit and 1792 * unacknowledged at any one time. If a sender, after sending 1793 * an ASCONF chunk, decides it needs to transfer another 1794 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk 1795 * returns from the previous ASCONF Chunk before sending a 1796 * subsequent ASCONF. Note this restriction binds each side, 1797 * so at any time two ASCONF may be in-transit on any given 1798 * association (one sent from each endpoint). 1799 * 1800 * 1801 * [I really think this is EXACTLY the sort of intelligence 1802 * which already resides in sctp_outq. Please move this 1803 * queue and its supporting logic down there. --piggy] 1804 */ 1805 struct list_head addip_chunk_list; 1806 1807 /* ADDIP Section 4.1 ASCONF Chunk Procedures 1808 * 1809 * A2) A serial number should be assigned to the Chunk. The 1810 * serial number SHOULD be a monotonically increasing 1811 * number. The serial number SHOULD be initialized at 1812 * the start of the association to the same value as the 1813 * Initial TSN and every time a new ASCONF chunk is created 1814 * it is incremented by one after assigning the serial number 1815 * to the newly created chunk. 1816 * 1817 * ADDIP 1818 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) 1819 * 1820 * Serial Number : 32 bits (unsigned integer) 1821 * 1822 * This value represents a Serial Number for the ASCONF 1823 * Chunk. The valid range of Serial Number is from 0 to 1824 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 1825 * after reaching 4294967295. 1826 */ 1827 __u32 addip_serial; 1828 union sctp_addr *asconf_addr_del_pending; 1829 int src_out_of_asoc_ok; 1830 struct sctp_transport *new_transport; 1831 1832 /* SCTP AUTH: list of the endpoint shared keys. These 1833 * keys are provided out of band by the user applicaton 1834 * and can't change during the lifetime of the association 1835 */ 1836 struct list_head endpoint_shared_keys; 1837 1838 /* SCTP AUTH: 1839 * The current generated assocaition shared key (secret) 1840 */ 1841 struct sctp_auth_bytes *asoc_shared_key; 1842 1843 /* SCTP AUTH: hmac id of the first peer requested algorithm 1844 * that we support. 1845 */ 1846 __u16 default_hmac_id; 1847 1848 __u16 active_key_id; 1849 1850 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */ 1851 temp:1; /* Is it a temporary association? */ 1852 1853 struct sctp_priv_assoc_stats stats; 1854}; 1855 1856 1857/* An eyecatcher for determining if we are really looking at an 1858 * association data structure. 1859 */ 1860enum { 1861 SCTP_ASSOC_EYECATCHER = 0xa550c123, 1862}; 1863 1864/* Recover the outter association structure. */ 1865static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) 1866{ 1867 struct sctp_association *asoc; 1868 1869 asoc = container_of(base, struct sctp_association, base); 1870 return asoc; 1871} 1872 1873/* These are function signatures for manipulating associations. */ 1874 1875 1876struct sctp_association * 1877sctp_association_new(const struct sctp_endpoint *, const struct sock *, 1878 sctp_scope_t scope, gfp_t gfp); 1879void sctp_association_free(struct sctp_association *); 1880void sctp_association_put(struct sctp_association *); 1881void sctp_association_hold(struct sctp_association *); 1882 1883struct sctp_transport *sctp_assoc_choose_alter_transport( 1884 struct sctp_association *, struct sctp_transport *); 1885void sctp_assoc_update_retran_path(struct sctp_association *); 1886struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, 1887 const union sctp_addr *); 1888int sctp_assoc_lookup_laddr(struct sctp_association *asoc, 1889 const union sctp_addr *laddr); 1890struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, 1891 const union sctp_addr *address, 1892 const gfp_t gfp, 1893 const int peer_state); 1894void sctp_assoc_del_peer(struct sctp_association *asoc, 1895 const union sctp_addr *addr); 1896void sctp_assoc_rm_peer(struct sctp_association *asoc, 1897 struct sctp_transport *peer); 1898void sctp_assoc_control_transport(struct sctp_association *, 1899 struct sctp_transport *, 1900 sctp_transport_cmd_t, sctp_sn_error_t); 1901struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); 1902struct sctp_transport *sctp_assoc_is_match(struct sctp_association *, 1903 struct net *, 1904 const union sctp_addr *, 1905 const union sctp_addr *); 1906void sctp_assoc_migrate(struct sctp_association *, struct sock *); 1907void sctp_assoc_update(struct sctp_association *old, 1908 struct sctp_association *new); 1909 1910__u32 sctp_association_get_next_tsn(struct sctp_association *); 1911 1912void sctp_assoc_sync_pmtu(struct sock *, struct sctp_association *); 1913void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int); 1914void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int); 1915void sctp_assoc_set_primary(struct sctp_association *, 1916 struct sctp_transport *); 1917void sctp_assoc_del_nonprimary_peers(struct sctp_association *, 1918 struct sctp_transport *); 1919int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *, 1920 sctp_scope_t, gfp_t); 1921int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, 1922 struct sctp_cookie*, 1923 gfp_t gfp); 1924int sctp_assoc_set_id(struct sctp_association *, gfp_t); 1925void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc); 1926struct sctp_chunk *sctp_assoc_lookup_asconf_ack( 1927 const struct sctp_association *asoc, 1928 __be32 serial); 1929void sctp_asconf_queue_teardown(struct sctp_association *asoc); 1930 1931int sctp_cmp_addr_exact(const union sctp_addr *ss1, 1932 const union sctp_addr *ss2); 1933struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); 1934 1935/* A convenience structure to parse out SCTP specific CMSGs. */ 1936typedef struct sctp_cmsgs { 1937 struct sctp_initmsg *init; 1938 struct sctp_sndrcvinfo *info; 1939} sctp_cmsgs_t; 1940 1941/* Structure for tracking memory objects */ 1942typedef struct { 1943 char *label; 1944 atomic_t *counter; 1945} sctp_dbg_objcnt_entry_t; 1946 1947#endif /* __sctp_structs_h__ */ 1948