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

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