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  */
  41 enum 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
  53 typedef 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);
  60 typedef void (sctp_timer_event_t) (struct timer_list *);
  61 struct 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. */
  71 sctp_state_fn_t sctp_sf_not_impl;
  72 sctp_state_fn_t sctp_sf_bug;
  73
  74 /* Prototypes for gener timer state functions. */
  75 sctp_state_fn_t sctp_sf_timer_ignore;
  76
  77 /* Prototypes for chunk state functions. */
  78 sctp_state_fn_t sctp_sf_do_9_1_abort;
  79 sctp_state_fn_t sctp_sf_cookie_wait_abort;
  80 sctp_state_fn_t sctp_sf_cookie_echoed_abort;
  81 sctp_state_fn_t sctp_sf_shutdown_pending_abort;
  82 sctp_state_fn_t sctp_sf_shutdown_sent_abort;
  83 sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort;
  84 sctp_state_fn_t sctp_sf_do_5_1B_init;
  85 sctp_state_fn_t sctp_sf_do_5_1C_ack;
  86 sctp_state_fn_t sctp_sf_do_5_1D_ce;
  87 sctp_state_fn_t sctp_sf_do_5_1E_ca;
  88 sctp_state_fn_t sctp_sf_do_4_C;
  89 sctp_state_fn_t sctp_sf_eat_data_6_2;
  90 sctp_state_fn_t sctp_sf_eat_data_fast_4_4;
  91 sctp_state_fn_t sctp_sf_eat_sack_6_2;
  92 sctp_state_fn_t sctp_sf_operr_notify;
  93 sctp_state_fn_t sctp_sf_t1_init_timer_expire;
  94 sctp_state_fn_t sctp_sf_t1_cookie_timer_expire;
  95 sctp_state_fn_t sctp_sf_t2_timer_expire;
  96 sctp_state_fn_t sctp_sf_t4_timer_expire;
  97 sctp_state_fn_t sctp_sf_t5_timer_expire;
  98 sctp_state_fn_t sctp_sf_sendbeat_8_3;
  99 sctp_state_fn_t sctp_sf_beat_8_3;
 100 sctp_state_fn_t sctp_sf_backbeat_8_3;
 101 sctp_state_fn_t sctp_sf_do_9_2_final;
 102 sctp_state_fn_t sctp_sf_do_9_2_shutdown;
 103 sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn;
 104 sctp_state_fn_t sctp_sf_do_ecn_cwr;
 105 sctp_state_fn_t sctp_sf_do_ecne;
 106 sctp_state_fn_t sctp_sf_ootb;
 107 sctp_state_fn_t sctp_sf_pdiscard;
 108 sctp_state_fn_t sctp_sf_violation;
 109 sctp_state_fn_t sctp_sf_discard_chunk;
 110 sctp_state_fn_t sctp_sf_do_5_2_1_siminit;
 111 sctp_state_fn_t sctp_sf_do_5_2_2_dupinit;
 112 sctp_state_fn_t sctp_sf_do_5_2_3_initack;
 113 sctp_state_fn_t sctp_sf_do_5_2_4_dupcook;
 114 sctp_state_fn_t sctp_sf_unk_chunk;
 115 sctp_state_fn_t sctp_sf_do_8_5_1_E_sa;
 116 sctp_state_fn_t sctp_sf_cookie_echoed_err;
 117 sctp_state_fn_t sctp_sf_do_asconf;
 118 sctp_state_fn_t sctp_sf_do_asconf_ack;
 119 sctp_state_fn_t sctp_sf_do_reconf;
 120 sctp_state_fn_t sctp_sf_do_9_2_reshutack;
 121 sctp_state_fn_t sctp_sf_eat_fwd_tsn;
 122 sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast;
 123 sctp_state_fn_t sctp_sf_eat_auth;
 124
 125 /* Prototypes for primitive event state functions.  */
 126 sctp_state_fn_t sctp_sf_do_prm_asoc;
 127 sctp_state_fn_t sctp_sf_do_prm_send;
 128 sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown;
 129 sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown;
 130 sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown;
 131 sctp_state_fn_t sctp_sf_do_9_1_prm_abort;
 132 sctp_state_fn_t sctp_sf_cookie_wait_prm_abort;
 133 sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort;
 134 sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort;
 135 sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort;
 136 sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort;
 137 sctp_state_fn_t sctp_sf_error_closed;
 138 sctp_state_fn_t sctp_sf_error_shutdown;
 139 sctp_state_fn_t sctp_sf_ignore_primitive;
 140 sctp_state_fn_t sctp_sf_do_prm_requestheartbeat;
 141 sctp_state_fn_t sctp_sf_do_prm_asconf;
 142 sctp_state_fn_t sctp_sf_do_prm_reconf;
 143
 144 /* Prototypes for other event state functions.  */
 145 sctp_state_fn_t sctp_sf_do_no_pending_tsn;
 146 sctp_state_fn_t sctp_sf_do_9_2_start_shutdown;
 147 sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack;
 148 sctp_state_fn_t sctp_sf_ignore_other;
 149 sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort;
 150
 151 /* Prototypes for timeout event state functions.  */
 152 sctp_state_fn_t sctp_sf_do_6_3_3_rtx;
 153 sctp_state_fn_t sctp_sf_send_reconf;
 154 sctp_state_fn_t sctp_sf_send_probe;
 155 sctp_state_fn_t sctp_sf_do_6_2_sack;
 156 sctp_state_fn_t sctp_sf_autoclose_timer_expire;
 157
 158 /* Prototypes for utility support functions.  */
 159 const struct sctp_sm_table_entry *sctp_sm_lookup_event(
 160                                         struct net *net,
 161                                         enum sctp_event_type event_type,
 162                                         enum sctp_state state,
 163                                         union sctp_subtype event_subtype);
 164 int sctp_chunk_iif(const struct sctp_chunk *);
 165 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *,
 166                                              struct sctp_chunk *,
 167                                              gfp_t gfp);
 168
 169 /* Prototypes for chunk-building functions.  */
 170 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
 171                                   const struct sctp_bind_addr *bp,
 172                                   gfp_t gfp, int vparam_len);
 173 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
 174                                       const struct sctp_chunk *chunk,
 175                                       const gfp_t gfp, const int unkparam_len);
 176 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
 177                                          const struct sctp_chunk *chunk);
 178 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
 179                                         const struct sctp_chunk *chunk);
 180 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
 181                                  const __u32 lowest_tsn,
 182                                  const struct sctp_chunk *chunk);
 183 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
 184                                    __u8 flags, int paylen, gfp_t gfp);
 185 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
 186                                      __u32 new_cum_tsn, size_t nstreams,
 187                                      struct sctp_ifwdtsn_skip *skiplist);
 188 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
 189                                             const struct sctp_sndrcvinfo *sinfo,
 190                                             int len, __u8 flags, gfp_t gfp);
 191 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
 192                                   const __u32 lowest_tsn);
 193 struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc);
 194 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
 195                                       const struct sctp_chunk *chunk);
 196 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
 197                                           const struct sctp_chunk *chunk);
 198 struct sctp_chunk *sctp_make_shutdown_complete(
 199                                         const struct sctp_association *asoc,
 200                                         const struct sctp_chunk *chunk);
 201 int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause, size_t paylen);
 202 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
 203                                    const struct sctp_chunk *chunk,
 204                                    const size_t hint);
 205 struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *asoc,
 206                                            const struct sctp_chunk *chunk,
 207                                            __u32 tsn);
 208 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
 209                                         struct msghdr *msg, size_t msg_len);
 210 struct sctp_chunk *sctp_make_abort_violation(
 211                                         const struct sctp_association *asoc,
 212                                         const struct sctp_chunk *chunk,
 213                                         const __u8 *payload,
 214                                         const size_t paylen);
 215 struct sctp_chunk *sctp_make_violation_paramlen(
 216                                         const struct sctp_association *asoc,
 217                                         const struct sctp_chunk *chunk,
 218                                         struct sctp_paramhdr *param);
 219 struct sctp_chunk *sctp_make_violation_max_retrans(
 220                                         const struct sctp_association *asoc,
 221                                         const struct sctp_chunk *chunk);
 222 struct sctp_chunk *sctp_make_new_encap_port(
 223                                         const struct sctp_association *asoc,
 224                                         const struct sctp_chunk *chunk);
 225 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
 226                                        const struct sctp_transport *transport,
 227                                        __u32 probe_size);
 228 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
 229                                            const struct sctp_chunk *chunk,
 230                                            const void *payload,
 231                                            const size_t paylen);
 232 struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len);
 233 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
 234                                       const struct sctp_chunk *chunk,
 235                                       __be16 cause_code, const void *payload,
 236                                       size_t paylen, size_t reserve_tail);
 237
 238 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
 239                                               union sctp_addr *laddr,
 240                                               struct sockaddr *addrs,
 241                                               int addrcnt, __be16 flags);
 242 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
 243                                              union sctp_addr *addr);
 244 bool sctp_verify_asconf(const struct sctp_association *asoc,
 245                         struct sctp_chunk *chunk, bool addr_param_needed,
 246                         struct sctp_paramhdr **errp);
 247 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
 248                                        struct sctp_chunk *asconf);
 249 int sctp_process_asconf_ack(struct sctp_association *asoc,
 250                             struct sctp_chunk *asconf_ack);
 251 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
 252                                     __u32 new_cum_tsn, size_t nstreams,
 253                                     struct sctp_fwdtsn_skip *skiplist);
 254 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
 255                                   __u16 key_id);
 256 struct sctp_chunk *sctp_make_strreset_req(const struct sctp_association *asoc,
 257                                           __u16 stream_num, __be16 *stream_list,
 258                                           bool out, bool in);
 259 struct sctp_chunk *sctp_make_strreset_tsnreq(
 260                                         const struct sctp_association *asoc);
 261 struct sctp_chunk *sctp_make_strreset_addstrm(
 262                                         const struct sctp_association *asoc,
 263                                         __u16 out, __u16 in);
 264 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
 265                                            __u32 result, __u32 sn);
 266 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
 267                                               __u32 result, __u32 sn,
 268                                               __u32 sender_tsn,
 269                                               __u32 receiver_tsn);
 270 bool sctp_verify_reconf(const struct sctp_association *asoc,
 271                         struct sctp_chunk *chunk,
 272                         struct sctp_paramhdr **errp);
 273 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk);
 274 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk);
 275
 276 /* Prototypes for stream-processing functions.  */
 277 struct sctp_chunk *sctp_process_strreset_outreq(
 278                                 struct sctp_association *asoc,
 279                                 union sctp_params param,
 280                                 struct sctp_ulpevent **evp);
 281 struct sctp_chunk *sctp_process_strreset_inreq(
 282                                 struct sctp_association *asoc,
 283                                 union sctp_params param,
 284                                 struct sctp_ulpevent **evp);
 285 struct sctp_chunk *sctp_process_strreset_tsnreq(
 286                                 struct sctp_association *asoc,
 287                                 union sctp_params param,
 288                                 struct sctp_ulpevent **evp);
 289 struct sctp_chunk *sctp_process_strreset_addstrm_out(
 290                                 struct sctp_association *asoc,
 291                                 union sctp_params param,
 292                                 struct sctp_ulpevent **evp);
 293 struct sctp_chunk *sctp_process_strreset_addstrm_in(
 294                                 struct sctp_association *asoc,
 295                                 union sctp_params param,
 296                                 struct sctp_ulpevent **evp);
 297 struct sctp_chunk *sctp_process_strreset_resp(
 298                                 struct sctp_association *asoc,
 299                                 union sctp_params param,
 300                                 struct sctp_ulpevent **evp);
 301
 302 /* Prototypes for statetable processing. */
 303
 304 int sctp_do_sm(struct net *net, enum sctp_event_type event_type,
 305                union sctp_subtype subtype, enum sctp_state state,
 306                struct sctp_endpoint *ep, struct sctp_association *asoc,
 307                void *event_arg, gfp_t gfp);
 308
 309 /* 2nd level prototypes */
 310 void sctp_generate_t3_rtx_event(struct timer_list *t);
 311 void sctp_generate_heartbeat_event(struct timer_list *t);
 312 void sctp_generate_reconf_event(struct timer_list *t);
 313 void sctp_generate_probe_event(struct timer_list *t);
 314 void sctp_generate_proto_unreach_event(struct timer_list *t);
 315
 316 void sctp_ootb_pkt_free(struct sctp_packet *packet);
 317
 318 struct sctp_association *sctp_unpack_cookie(
 319                                         const struct sctp_endpoint *ep,
 320                                         const struct sctp_association *asoc,
 321                                         struct sctp_chunk *chunk,
 322                                         gfp_t gfp, int *err,
 323                                         struct sctp_chunk **err_chk_p);
 324
 325 /* 3rd level prototypes */
 326 __u32 sctp_generate_tag(const struct sctp_endpoint *ep);
 327 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep);
 328
 329 /* Extern declarations for major data structures.  */
 330 extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES];
 331
 332
 333 /* Get the size of a DATA chunk payload. */
 334 static inline __u16 sctp_data_size(struct sctp_chunk *chunk)
 335 {
 336         __u16 size;
 337
 338         size = ntohs(chunk->chunk_hdr->length);
 339         size -= sctp_datachk_len(&chunk->asoc->stream);
 340
 341         return size;
 342 }
 343
 344 /* Compare two TSNs */
 345 #define TSN_lt(a,b)     \
 346         (typecheck(__u32, a) && \
 347          typecheck(__u32, b) && \
 348          ((__s32)((a) - (b)) < 0))
 349
 350 #define TSN_lte(a,b)    \
 351         (typecheck(__u32, a) && \
 352          typecheck(__u32, b) && \
 353          ((__s32)((a) - (b)) <= 0))
 354
 355 /* Compare two MIDs */
 356 #define MID_lt(a, b)    \
 357         (typecheck(__u32, a) && \
 358          typecheck(__u32, b) && \
 359          ((__s32)((a) - (b)) < 0))
 360
 361 /* Compare two SSNs */
 362 #define SSN_lt(a,b)             \
 363         (typecheck(__u16, a) && \
 364          typecheck(__u16, b) && \
 365          ((__s16)((a) - (b)) < 0))
 366
 367 /* ADDIP 3.1.1 */
 368 #define ADDIP_SERIAL_gte(a,b)   \
 369         (typecheck(__u32, a) && \
 370          typecheck(__u32, b) && \
 371          ((__s32)((b) - (a)) <= 0))
 372
 373 /* Check VTAG of the packet matches the sender's own tag. */
 374 static inline int
 375 sctp_vtag_verify(const struct sctp_chunk *chunk,
 376                  const struct sctp_association *asoc)
 377 {
 378         /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint
 379          * MUST ensure that the value in the Verification Tag field of
 380          * the received SCTP packet matches its own Tag. If the received
 381          * Verification Tag value does not match the receiver's own
 382          * tag value, the receiver shall silently discard the packet...
 383          */
 384         if (ntohl(chunk->sctp_hdr->vtag) != asoc->c.my_vtag)
 385                 return 0;
 386
 387         chunk->transport->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port;
 388         return 1;
 389 }
 390
 391 /* Check VTAG of the packet matches the sender's own tag and the T bit is
 392  * not set, OR its peer's tag and the T bit is set in the Chunk Flags.
 393  */
 394 static inline int
 395 sctp_vtag_verify_either(const struct sctp_chunk *chunk,
 396                         const struct sctp_association *asoc)
 397 {
 398         /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41
 399          *
 400          * B) The receiver of a ABORT MUST accept the packet
 401          *    if the Verification Tag field of the packet matches its own tag
 402          *    and the T bit is not set
 403          *    OR
 404          *    it is set to its peer's tag and the T bit is set in the Chunk
 405          *    Flags.
 406          *    Otherwise, the receiver MUST silently discard the packet
 407          *    and take no further action.
 408          *
 409          * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet
 410          *    if the Verification Tag field of the packet matches its own tag
 411          *    and the T bit is not set
 412          *    OR
 413          *    it is set to its peer's tag and the T bit is set in the Chunk
 414          *    Flags.
 415          *    Otherwise, the receiver MUST silently discard the packet
 416          *    and take no further action.  An endpoint MUST ignore the
 417          *    SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
 418          */
 419         if ((!sctp_test_T_bit(chunk) &&
 420              (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) ||
 421             (sctp_test_T_bit(chunk) && asoc->c.peer_vtag &&
 422              (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) {
 423                 return 1;
 424         }
 425
 426         return 0;
 427 }
 428
 429 #endif /* __sctp_sm_h__ */