LXR linux/include/net/sctp/sm.h

   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 * These are definitions needed by the state machine.
  10 *
  11 * This SCTP implementation is free software;
  12 * you can redistribute it and/or modify it under the terms of
  13 * the GNU General Public License as published by
  14 * the Free Software Foundation; either version 2, or (at your option)
  15 * any later version.
  16 *
  17 * This SCTP implementation is distributed in the hope that it
  18 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  19 *                 ************************
  20 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  21 * See the GNU General Public License for more details.
  22 *
  23 * You should have received a copy of the GNU General Public License
  24 * along with GNU CC; see the file COPYING.  If not, see
  25 * <http://www.gnu.org/licenses/>.
  26 *
  27 * Please send any bug reports or fixes you make to the
  28 * email addresses:
  29 *    lksctp developers <linux-sctp@vger.kernel.org>
  30 *
  31 * Written or modified by:
  32 *    La Monte H.P. Yarroll <piggy@acm.org>
  33 *    Karl Knutson <karl@athena.chicago.il.us>
  34 *    Xingang Guo <xingang.guo@intel.com>
  35 *    Jon Grimm <jgrimm@us.ibm.com>
  36 *    Dajiang Zhang <dajiang.zhang@nokia.com>
  37 *    Sridhar Samudrala <sri@us.ibm.com>
  38 *    Daisy Chang <daisyc@us.ibm.com>
  39 *    Ardelle Fan <ardelle.fan@intel.com>
  40 *    Kevin Gao <kevin.gao@intel.com>
  41 */
  42
  43#include <linux/types.h>
  44#include <linux/compiler.h>
  45#include <linux/slab.h>
  46#include <linux/in.h>
  47#include <net/sctp/command.h>
  48#include <net/sctp/sctp.h>
  49
  50#ifndef __sctp_sm_h__
  51#define __sctp_sm_h__
  52
  53/*
  54 * Possible values for the disposition are:
  55 */
  56enum sctp_disposition {
  57        SCTP_DISPOSITION_DISCARD,        /* No further processing.  */
  58        SCTP_DISPOSITION_CONSUME,        /* Process return values normally.  */
  59        SCTP_DISPOSITION_NOMEM,          /* We ran out of memory--recover.  */
  60        SCTP_DISPOSITION_DELETE_TCB,     /* Close the association.  */
  61        SCTP_DISPOSITION_ABORT,          /* Close the association NOW.  */
  62        SCTP_DISPOSITION_VIOLATION,      /* The peer is misbehaving.  */
  63        SCTP_DISPOSITION_NOT_IMPL,       /* This entry is not implemented.  */
  64        SCTP_DISPOSITION_ERROR,          /* This is plain old user error.  */
  65        SCTP_DISPOSITION_BUG,            /* This is a bug.  */
  66};
  67
  68typedef enum sctp_disposition (sctp_state_fn_t) (
  69                                        struct net *net,
  70                                        const struct sctp_endpoint *ep,
  71                                        const struct sctp_association *asoc,
  72                                        const union sctp_subtype type,
  73                                        void *arg,
  74                                        struct sctp_cmd_seq *commands);
  75typedef void (sctp_timer_event_t) (struct timer_list *);
  76struct sctp_sm_table_entry {
  77        sctp_state_fn_t *fn;
  78        const char *name;
  79};
  80
  81/* A naming convention of "sctp_sf_xxx" applies to all the state functions
  82 * currently in use.
  83 */
  84
  85/* Prototypes for generic state functions. */
  86sctp_state_fn_t sctp_sf_not_impl;
  87sctp_state_fn_t sctp_sf_bug;
  88
  89/* Prototypes for gener timer state functions. */
  90sctp_state_fn_t sctp_sf_timer_ignore;
  91
  92/* Prototypes for chunk state functions. */
  93sctp_state_fn_t sctp_sf_do_9_1_abort;
  94sctp_state_fn_t sctp_sf_cookie_wait_abort;
  95sctp_state_fn_t sctp_sf_cookie_echoed_abort;
  96sctp_state_fn_t sctp_sf_shutdown_pending_abort;
  97sctp_state_fn_t sctp_sf_shutdown_sent_abort;
  98sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort;
  99sctp_state_fn_t sctp_sf_do_5_1B_init;
 100sctp_state_fn_t sctp_sf_do_5_1C_ack;
 101sctp_state_fn_t sctp_sf_do_5_1D_ce;
 102sctp_state_fn_t sctp_sf_do_5_1E_ca;
 103sctp_state_fn_t sctp_sf_do_4_C;
 104sctp_state_fn_t sctp_sf_eat_data_6_2;
 105sctp_state_fn_t sctp_sf_eat_data_fast_4_4;
 106sctp_state_fn_t sctp_sf_eat_sack_6_2;
 107sctp_state_fn_t sctp_sf_operr_notify;
 108sctp_state_fn_t sctp_sf_t1_init_timer_expire;
 109sctp_state_fn_t sctp_sf_t1_cookie_timer_expire;
 110sctp_state_fn_t sctp_sf_t2_timer_expire;
 111sctp_state_fn_t sctp_sf_t4_timer_expire;
 112sctp_state_fn_t sctp_sf_t5_timer_expire;
 113sctp_state_fn_t sctp_sf_sendbeat_8_3;
 114sctp_state_fn_t sctp_sf_beat_8_3;
 115sctp_state_fn_t sctp_sf_backbeat_8_3;
 116sctp_state_fn_t sctp_sf_do_9_2_final;
 117sctp_state_fn_t sctp_sf_do_9_2_shutdown;
 118sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn;
 119sctp_state_fn_t sctp_sf_do_ecn_cwr;
 120sctp_state_fn_t sctp_sf_do_ecne;
 121sctp_state_fn_t sctp_sf_ootb;
 122sctp_state_fn_t sctp_sf_pdiscard;
 123sctp_state_fn_t sctp_sf_violation;
 124sctp_state_fn_t sctp_sf_discard_chunk;
 125sctp_state_fn_t sctp_sf_do_5_2_1_siminit;
 126sctp_state_fn_t sctp_sf_do_5_2_2_dupinit;
 127sctp_state_fn_t sctp_sf_do_5_2_3_initack;
 128sctp_state_fn_t sctp_sf_do_5_2_4_dupcook;
 129sctp_state_fn_t sctp_sf_unk_chunk;
 130sctp_state_fn_t sctp_sf_do_8_5_1_E_sa;
 131sctp_state_fn_t sctp_sf_cookie_echoed_err;
 132sctp_state_fn_t sctp_sf_do_asconf;
 133sctp_state_fn_t sctp_sf_do_asconf_ack;
 134sctp_state_fn_t sctp_sf_do_reconf;
 135sctp_state_fn_t sctp_sf_do_9_2_reshutack;
 136sctp_state_fn_t sctp_sf_eat_fwd_tsn;
 137sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast;
 138sctp_state_fn_t sctp_sf_eat_auth;
 139
 140/* Prototypes for primitive event state functions.  */
 141sctp_state_fn_t sctp_sf_do_prm_asoc;
 142sctp_state_fn_t sctp_sf_do_prm_send;
 143sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown;
 144sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown;
 145sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown;
 146sctp_state_fn_t sctp_sf_do_9_1_prm_abort;
 147sctp_state_fn_t sctp_sf_cookie_wait_prm_abort;
 148sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort;
 149sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort;
 150sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort;
 151sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort;
 152sctp_state_fn_t sctp_sf_error_closed;
 153sctp_state_fn_t sctp_sf_error_shutdown;
 154sctp_state_fn_t sctp_sf_ignore_primitive;
 155sctp_state_fn_t sctp_sf_do_prm_requestheartbeat;
 156sctp_state_fn_t sctp_sf_do_prm_asconf;
 157sctp_state_fn_t sctp_sf_do_prm_reconf;
 158
 159/* Prototypes for other event state functions.  */
 160sctp_state_fn_t sctp_sf_do_no_pending_tsn;
 161sctp_state_fn_t sctp_sf_do_9_2_start_shutdown;
 162sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack;
 163sctp_state_fn_t sctp_sf_ignore_other;
 164sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort;
 165
 166/* Prototypes for timeout event state functions.  */
 167sctp_state_fn_t sctp_sf_do_6_3_3_rtx;
 168sctp_state_fn_t sctp_sf_send_reconf;
 169sctp_state_fn_t sctp_sf_do_6_2_sack;
 170sctp_state_fn_t sctp_sf_autoclose_timer_expire;
 171
 172/* Prototypes for utility support functions.  */
 173__u8 sctp_get_chunk_type(struct sctp_chunk *chunk);
 174const struct sctp_sm_table_entry *sctp_sm_lookup_event(
 175                                        struct net *net,
 176                                        enum sctp_event_type event_type,
 177                                        enum sctp_state state,
 178                                        union sctp_subtype event_subtype);
 179int sctp_chunk_iif(const struct sctp_chunk *);
 180struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *,
 181                                             struct sctp_chunk *,
 182                                             gfp_t gfp);
 183__u32 sctp_generate_verification_tag(void);
 184void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag);
 185
 186/* Prototypes for chunk-building functions.  */
 187struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
 188                                  const struct sctp_bind_addr *bp,
 189                                  gfp_t gfp, int vparam_len);
 190struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
 191                                      const struct sctp_chunk *chunk,
 192                                      const gfp_t gfp, const int unkparam_len);
 193struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
 194                                         const struct sctp_chunk *chunk);
 195struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
 196                                        const struct sctp_chunk *chunk);
 197struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
 198                                 const __u32 lowest_tsn,
 199                                 const struct sctp_chunk *chunk);
 200struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
 201                                   __u8 flags, int paylen, gfp_t gfp);
 202struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
 203                                     __u32 new_cum_tsn, size_t nstreams,
 204                                     struct sctp_ifwdtsn_skip *skiplist);
 205struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
 206                                            const struct sctp_sndrcvinfo *sinfo,
 207                                            int len, __u8 flags, gfp_t gfp);
 208struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
 209                                  const __u32 lowest_tsn);
 210struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc);
 211struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
 212                                      const struct sctp_chunk *chunk);
 213struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
 214                                          const struct sctp_chunk *chunk);
 215struct sctp_chunk *sctp_make_shutdown_complete(
 216                                        const struct sctp_association *asoc,
 217                                        const struct sctp_chunk *chunk);
 218int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause, size_t paylen);
 219struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
 220                                   const struct sctp_chunk *chunk,
 221                                   const size_t hint);
 222struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *asoc,
 223                                           const struct sctp_chunk *chunk,
 224                                           __u32 tsn);
 225struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
 226                                        struct msghdr *msg, size_t msg_len);
 227struct sctp_chunk *sctp_make_abort_violation(
 228                                        const struct sctp_association *asoc,
 229                                        const struct sctp_chunk *chunk,
 230                                        const __u8 *payload,
 231                                        const size_t paylen);
 232struct sctp_chunk *sctp_make_violation_paramlen(
 233                                        const struct sctp_association *asoc,
 234                                        const struct sctp_chunk *chunk,
 235                                        struct sctp_paramhdr *param);
 236struct sctp_chunk *sctp_make_violation_max_retrans(
 237                                        const struct sctp_association *asoc,
 238                                        const struct sctp_chunk *chunk);
 239struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
 240                                       const struct sctp_transport *transport);
 241struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
 242                                           const struct sctp_chunk *chunk,
 243                                           const void *payload,
 244                                           const size_t paylen);
 245struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
 246                                      const struct sctp_chunk *chunk,
 247                                      __be16 cause_code, const void *payload,
 248                                      size_t paylen, size_t reserve_tail);
 249
 250struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
 251                                              union sctp_addr *laddr,
 252                                              struct sockaddr *addrs,
 253                                              int addrcnt, __be16 flags);
 254struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
 255                                             union sctp_addr *addr);
 256bool sctp_verify_asconf(const struct sctp_association *asoc,
 257                        struct sctp_chunk *chunk, bool addr_param_needed,
 258                        struct sctp_paramhdr **errp);
 259struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
 260                                       struct sctp_chunk *asconf);
 261int sctp_process_asconf_ack(struct sctp_association *asoc,
 262                            struct sctp_chunk *asconf_ack);
 263struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
 264                                    __u32 new_cum_tsn, size_t nstreams,
 265                                    struct sctp_fwdtsn_skip *skiplist);
 266struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
 267                                  __u16 key_id);
 268struct sctp_chunk *sctp_make_strreset_req(const struct sctp_association *asoc,
 269                                          __u16 stream_num, __be16 *stream_list,
 270                                          bool out, bool in);
 271struct sctp_chunk *sctp_make_strreset_tsnreq(
 272                                        const struct sctp_association *asoc);
 273struct sctp_chunk *sctp_make_strreset_addstrm(
 274                                        const struct sctp_association *asoc,
 275                                        __u16 out, __u16 in);
 276struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
 277                                           __u32 result, __u32 sn);
 278struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
 279                                              __u32 result, __u32 sn,
 280                                              __u32 sender_tsn,
 281                                              __u32 receiver_tsn);
 282bool sctp_verify_reconf(const struct sctp_association *asoc,
 283                        struct sctp_chunk *chunk,
 284                        struct sctp_paramhdr **errp);
 285void sctp_chunk_assign_tsn(struct sctp_chunk *chunk);
 286void sctp_chunk_assign_ssn(struct sctp_chunk *chunk);
 287
 288/* Prototypes for stream-processing functions.  */
 289struct sctp_chunk *sctp_process_strreset_outreq(
 290                                struct sctp_association *asoc,
 291                                union sctp_params param,
 292                                struct sctp_ulpevent **evp);
 293struct sctp_chunk *sctp_process_strreset_inreq(
 294                                struct sctp_association *asoc,
 295                                union sctp_params param,
 296                                struct sctp_ulpevent **evp);
 297struct sctp_chunk *sctp_process_strreset_tsnreq(
 298                                struct sctp_association *asoc,
 299                                union sctp_params param,
 300                                struct sctp_ulpevent **evp);
 301struct sctp_chunk *sctp_process_strreset_addstrm_out(
 302                                struct sctp_association *asoc,
 303                                union sctp_params param,
 304                                struct sctp_ulpevent **evp);
 305struct sctp_chunk *sctp_process_strreset_addstrm_in(
 306                                struct sctp_association *asoc,
 307                                union sctp_params param,
 308                                struct sctp_ulpevent **evp);
 309struct sctp_chunk *sctp_process_strreset_resp(
 310                                struct sctp_association *asoc,
 311                                union sctp_params param,
 312                                struct sctp_ulpevent **evp);
 313
 314/* Prototypes for statetable processing. */
 315
 316int sctp_do_sm(struct net *net, enum sctp_event_type event_type,
 317               union sctp_subtype subtype, enum sctp_state state,
 318               struct sctp_endpoint *ep, struct sctp_association *asoc,
 319               void *event_arg, gfp_t gfp);
 320
 321/* 2nd level prototypes */
 322void sctp_generate_t3_rtx_event(struct timer_list *t);
 323void sctp_generate_heartbeat_event(struct timer_list *t);
 324void sctp_generate_reconf_event(struct timer_list *t);
 325void sctp_generate_proto_unreach_event(struct timer_list *t);
 326
 327void sctp_ootb_pkt_free(struct sctp_packet *packet);
 328
 329struct sctp_association *sctp_unpack_cookie(
 330                                        const struct sctp_endpoint *ep,
 331                                        const struct sctp_association *asoc,
 332                                        struct sctp_chunk *chunk,
 333                                        gfp_t gfp, int *err,
 334                                        struct sctp_chunk **err_chk_p);
 335
 336/* 3rd level prototypes */
 337__u32 sctp_generate_tag(const struct sctp_endpoint *ep);
 338__u32 sctp_generate_tsn(const struct sctp_endpoint *ep);
 339
 340/* Extern declarations for major data structures.  */
 341extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES];
 342
 343
 344/* Get the size of a DATA chunk payload. */
 345static inline __u16 sctp_data_size(struct sctp_chunk *chunk)
 346{
 347        __u16 size;
 348
 349        size = ntohs(chunk->chunk_hdr->length);
 350        size -= sctp_datachk_len(&chunk->asoc->stream);
 351
 352        return size;
 353}
 354
 355/* Compare two TSNs */
 356#define TSN_lt(a,b)     \
 357        (typecheck(__u32, a) && \
 358         typecheck(__u32, b) && \
 359         ((__s32)((a) - (b)) < 0))
 360
 361#define TSN_lte(a,b)    \
 362        (typecheck(__u32, a) && \
 363         typecheck(__u32, b) && \
 364         ((__s32)((a) - (b)) <= 0))
 365
 366/* Compare two MIDs */
 367#define MID_lt(a, b)    \
 368        (typecheck(__u32, a) && \
 369         typecheck(__u32, b) && \
 370         ((__s32)((a) - (b)) < 0))
 371
 372/* Compare two SSNs */
 373#define SSN_lt(a,b)             \
 374        (typecheck(__u16, a) && \
 375         typecheck(__u16, b) && \
 376         ((__s16)((a) - (b)) < 0))
 377
 378/* ADDIP 3.1.1 */
 379#define ADDIP_SERIAL_gte(a,b)   \
 380        (typecheck(__u32, a) && \
 381         typecheck(__u32, b) && \
 382         ((__s32)((b) - (a)) <= 0))
 383
 384/* Check VTAG of the packet matches the sender's own tag. */
 385static inline int
 386sctp_vtag_verify(const struct sctp_chunk *chunk,
 387                 const struct sctp_association *asoc)
 388{
 389        /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint
 390         * MUST ensure that the value in the Verification Tag field of
 391         * the received SCTP packet matches its own Tag. If the received
 392         * Verification Tag value does not match the receiver's own
 393         * tag value, the receiver shall silently discard the packet...
 394         */
 395        if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)
 396                return 1;
 397
 398        return 0;
 399}
 400
 401/* Check VTAG of the packet matches the sender's own tag and the T bit is
 402 * not set, OR its peer's tag and the T bit is set in the Chunk Flags.
 403 */
 404static inline int
 405sctp_vtag_verify_either(const struct sctp_chunk *chunk,
 406                        const struct sctp_association *asoc)
 407{
 408        /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41
 409         *
 410         * B) The receiver of a ABORT MUST accept the packet
 411         *    if the Verification Tag field of the packet matches its own tag
 412         *    and the T bit is not set
 413         *    OR
 414         *    it is set to its peer's tag and the T bit is set in the Chunk
 415         *    Flags.
 416         *    Otherwise, the receiver MUST silently discard the packet
 417         *    and take no further action.
 418         *
 419         * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet
 420         *    if the Verification Tag field of the packet matches its own tag
 421         *    and the T bit is not set
 422         *    OR
 423         *    it is set to its peer's tag and the T bit is set in the Chunk
 424         *    Flags.
 425         *    Otherwise, the receiver MUST silently discard the packet
 426         *    and take no further action.  An endpoint MUST ignore the
 427         *    SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
 428         */
 429        if ((!sctp_test_T_bit(chunk) &&
 430             (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) ||
 431            (sctp_test_T_bit(chunk) && asoc->c.peer_vtag &&
 432             (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) {
 433                return 1;
 434        }
 435
 436        return 0;
 437}
 438
 439#endif /* __sctp_sm_h__ */
 440