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  */
  56 typedef enum {
  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 } sctp_disposition_t;
  67
  68 typedef struct {
  69         int name;
  70         int action;
  71 } sctp_sm_command_t;
  72
  73 typedef sctp_disposition_t (sctp_state_fn_t) (struct net *,
  74                                               const struct sctp_endpoint *,
  75                                               const struct sctp_association *,
  76                                               const sctp_subtype_t type,
  77                                               void *arg,
  78                                               sctp_cmd_seq_t *);
  79 typedef void (sctp_timer_event_t) (unsigned long);
  80 typedef struct {
  81         sctp_state_fn_t *fn;
  82         const char *name;
  83 } sctp_sm_table_entry_t;
  84
  85 /* A naming convention of "sctp_sf_xxx" applies to all the state functions
  86  * currently in use.
  87  */
  88
  89 /* Prototypes for generic state functions. */
  90 sctp_state_fn_t sctp_sf_not_impl;
  91 sctp_state_fn_t sctp_sf_bug;
  92
  93 /* Prototypes for gener timer state functions. */
  94 sctp_state_fn_t sctp_sf_timer_ignore;
  95
  96 /* Prototypes for chunk state functions. */
  97 sctp_state_fn_t sctp_sf_do_9_1_abort;
  98 sctp_state_fn_t sctp_sf_cookie_wait_abort;
  99 sctp_state_fn_t sctp_sf_cookie_echoed_abort;
 100 sctp_state_fn_t sctp_sf_shutdown_pending_abort;
 101 sctp_state_fn_t sctp_sf_shutdown_sent_abort;
 102 sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort;
 103 sctp_state_fn_t sctp_sf_do_5_1B_init;
 104 sctp_state_fn_t sctp_sf_do_5_1C_ack;
 105 sctp_state_fn_t sctp_sf_do_5_1D_ce;
 106 sctp_state_fn_t sctp_sf_do_5_1E_ca;
 107 sctp_state_fn_t sctp_sf_do_4_C;
 108 sctp_state_fn_t sctp_sf_eat_data_6_2;
 109 sctp_state_fn_t sctp_sf_eat_data_fast_4_4;
 110 sctp_state_fn_t sctp_sf_eat_sack_6_2;
 111 sctp_state_fn_t sctp_sf_operr_notify;
 112 sctp_state_fn_t sctp_sf_t1_init_timer_expire;
 113 sctp_state_fn_t sctp_sf_t1_cookie_timer_expire;
 114 sctp_state_fn_t sctp_sf_t2_timer_expire;
 115 sctp_state_fn_t sctp_sf_t4_timer_expire;
 116 sctp_state_fn_t sctp_sf_t5_timer_expire;
 117 sctp_state_fn_t sctp_sf_sendbeat_8_3;
 118 sctp_state_fn_t sctp_sf_beat_8_3;
 119 sctp_state_fn_t sctp_sf_backbeat_8_3;
 120 sctp_state_fn_t sctp_sf_do_9_2_final;
 121 sctp_state_fn_t sctp_sf_do_9_2_shutdown;
 122 sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn;
 123 sctp_state_fn_t sctp_sf_do_ecn_cwr;
 124 sctp_state_fn_t sctp_sf_do_ecne;
 125 sctp_state_fn_t sctp_sf_ootb;
 126 sctp_state_fn_t sctp_sf_pdiscard;
 127 sctp_state_fn_t sctp_sf_violation;
 128 sctp_state_fn_t sctp_sf_discard_chunk;
 129 sctp_state_fn_t sctp_sf_do_5_2_1_siminit;
 130 sctp_state_fn_t sctp_sf_do_5_2_2_dupinit;
 131 sctp_state_fn_t sctp_sf_do_5_2_3_initack;
 132 sctp_state_fn_t sctp_sf_do_5_2_4_dupcook;
 133 sctp_state_fn_t sctp_sf_unk_chunk;
 134 sctp_state_fn_t sctp_sf_do_8_5_1_E_sa;
 135 sctp_state_fn_t sctp_sf_cookie_echoed_err;
 136 sctp_state_fn_t sctp_sf_do_asconf;
 137 sctp_state_fn_t sctp_sf_do_asconf_ack;
 138 sctp_state_fn_t sctp_sf_do_reconf;
 139 sctp_state_fn_t sctp_sf_do_9_2_reshutack;
 140 sctp_state_fn_t sctp_sf_eat_fwd_tsn;
 141 sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast;
 142 sctp_state_fn_t sctp_sf_eat_auth;
 143
 144 /* Prototypes for primitive event state functions.  */
 145 sctp_state_fn_t sctp_sf_do_prm_asoc;
 146 sctp_state_fn_t sctp_sf_do_prm_send;
 147 sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown;
 148 sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown;
 149 sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown;
 150 sctp_state_fn_t sctp_sf_do_9_1_prm_abort;
 151 sctp_state_fn_t sctp_sf_cookie_wait_prm_abort;
 152 sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort;
 153 sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort;
 154 sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort;
 155 sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort;
 156 sctp_state_fn_t sctp_sf_error_closed;
 157 sctp_state_fn_t sctp_sf_error_shutdown;
 158 sctp_state_fn_t sctp_sf_ignore_primitive;
 159 sctp_state_fn_t sctp_sf_do_prm_requestheartbeat;
 160 sctp_state_fn_t sctp_sf_do_prm_asconf;
 161 sctp_state_fn_t sctp_sf_do_prm_reconf;
 162
 163 /* Prototypes for other event state functions.  */
 164 sctp_state_fn_t sctp_sf_do_no_pending_tsn;
 165 sctp_state_fn_t sctp_sf_do_9_2_start_shutdown;
 166 sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack;
 167 sctp_state_fn_t sctp_sf_ignore_other;
 168 sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort;
 169
 170 /* Prototypes for timeout event state functions.  */
 171 sctp_state_fn_t sctp_sf_do_6_3_3_rtx;
 172 sctp_state_fn_t sctp_sf_send_reconf;
 173 sctp_state_fn_t sctp_sf_do_6_2_sack;
 174 sctp_state_fn_t sctp_sf_autoclose_timer_expire;
 175
 176 /* Prototypes for utility support functions.  */
 177 __u8 sctp_get_chunk_type(struct sctp_chunk *chunk);
 178 const sctp_sm_table_entry_t *sctp_sm_lookup_event(struct net *,
 179                                             sctp_event_t,
 180                                             sctp_state_t,
 181                                             sctp_subtype_t);
 182 int sctp_chunk_iif(const struct sctp_chunk *);
 183 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *,
 184                                              struct sctp_chunk *,
 185                                              gfp_t gfp);
 186 __u32 sctp_generate_verification_tag(void);
 187 void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag);
 188
 189 /* Prototypes for chunk-building functions.  */
 190 struct sctp_chunk *sctp_make_init(const struct sctp_association *,
 191                              const struct sctp_bind_addr *,
 192                              gfp_t gfp, int vparam_len);
 193 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *,
 194                                  const struct sctp_chunk *,
 195                                  const gfp_t gfp,
 196                                  const int unkparam_len);
 197 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *,
 198                                     const struct sctp_chunk *);
 199 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *,
 200                                    const struct sctp_chunk *);
 201 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *,
 202                                  const __u32 lowest_tsn,
 203                                  const struct sctp_chunk *);
 204 struct sctp_chunk * sctp_make_datafrag_empty(struct sctp_association *,
 205                                         const struct sctp_sndrcvinfo *sinfo,
 206                                         int len, const __u8 flags,
 207                                         __u16 ssn, gfp_t gfp);
 208 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *,
 209                                   const __u32);
 210 struct sctp_chunk *sctp_make_sack(const struct sctp_association *);
 211 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
 212                                       const struct sctp_chunk *chunk);
 213 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
 214                                           const struct sctp_chunk *);
 215 struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *,
 216                                           const struct sctp_chunk *);
 217 void sctp_init_cause(struct sctp_chunk *, __be16 cause, size_t);
 218 struct sctp_chunk *sctp_make_abort(const struct sctp_association *,
 219                               const struct sctp_chunk *,
 220                               const size_t hint);
 221 struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *,
 222                                       const struct sctp_chunk *,
 223                                       __u32 tsn);
 224 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *,
 225                                         struct msghdr *, size_t msg_len);
 226 struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *,
 227                                    const struct sctp_chunk *,
 228                                    const __u8 *,
 229                                    const size_t );
 230 struct sctp_chunk *sctp_make_violation_paramlen(const struct sctp_association *,
 231                                    const struct sctp_chunk *,
 232                                    struct sctp_paramhdr *);
 233 struct sctp_chunk *sctp_make_violation_max_retrans(const struct sctp_association *,
 234                                                    const struct sctp_chunk *);
 235 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *,
 236                                   const struct sctp_transport *);
 237 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *,
 238                                       const struct sctp_chunk *,
 239                                       const void *payload,
 240                                       const size_t paylen);
 241 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *,
 242                                  const struct sctp_chunk *chunk,
 243                                  __be16 cause_code,
 244                                  const void *payload,
 245                                  size_t paylen,
 246                                  size_t reserve_tail);
 247
 248 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *,
 249                                               union sctp_addr *,
 250                                               struct sockaddr *,
 251                                               int, __be16);
 252 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
 253                                              union sctp_addr *addr);
 254 bool sctp_verify_asconf(const struct sctp_association *asoc,
 255                         struct sctp_chunk *chunk, bool addr_param_needed,
 256                         struct sctp_paramhdr **errp);
 257 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
 258                                        struct sctp_chunk *asconf);
 259 int sctp_process_asconf_ack(struct sctp_association *asoc,
 260                             struct sctp_chunk *asconf_ack);
 261 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
 262                                     __u32 new_cum_tsn, size_t nstreams,
 263                                     struct sctp_fwdtsn_skip *skiplist);
 264 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc);
 265 struct sctp_chunk *sctp_make_strreset_req(
 266                                 const struct sctp_association *asoc,
 267                                 __u16 stream_num, __u16 *stream_list,
 268                                 bool out, bool in);
 269 struct sctp_chunk *sctp_make_strreset_tsnreq(
 270                                 const struct sctp_association *asoc);
 271 struct sctp_chunk *sctp_make_strreset_addstrm(
 272                                 const struct sctp_association *asoc,
 273                                 __u16 out, __u16 in);
 274 struct sctp_chunk *sctp_make_strreset_resp(
 275                                 const struct sctp_association *asoc,
 276                                 __u32 result, __u32 sn);
 277 struct sctp_chunk *sctp_make_strreset_tsnresp(
 278                                 struct sctp_association *asoc,
 279                                 __u32 result, __u32 sn,
 280                                 __u32 sender_tsn, __u32 receiver_tsn);
 281 bool sctp_verify_reconf(const struct sctp_association *asoc,
 282                         struct sctp_chunk *chunk,
 283                         struct sctp_paramhdr **errp);
 284 void sctp_chunk_assign_tsn(struct sctp_chunk *);
 285 void sctp_chunk_assign_ssn(struct sctp_chunk *);
 286
 287 /* Prototypes for stream-processing functions.  */
 288 struct sctp_chunk *sctp_process_strreset_outreq(
 289                                 struct sctp_association *asoc,
 290                                 union sctp_params param,
 291                                 struct sctp_ulpevent **evp);
 292 struct sctp_chunk *sctp_process_strreset_inreq(
 293                                 struct sctp_association *asoc,
 294                                 union sctp_params param,
 295                                 struct sctp_ulpevent **evp);
 296 struct sctp_chunk *sctp_process_strreset_tsnreq(
 297                                 struct sctp_association *asoc,
 298                                 union sctp_params param,
 299                                 struct sctp_ulpevent **evp);
 300 struct sctp_chunk *sctp_process_strreset_addstrm_out(
 301                                 struct sctp_association *asoc,
 302                                 union sctp_params param,
 303                                 struct sctp_ulpevent **evp);
 304 struct sctp_chunk *sctp_process_strreset_addstrm_in(
 305                                 struct sctp_association *asoc,
 306                                 union sctp_params param,
 307                                 struct sctp_ulpevent **evp);
 308 struct sctp_chunk *sctp_process_strreset_resp(
 309                                 struct sctp_association *asoc,
 310                                 union sctp_params param,
 311                                 struct sctp_ulpevent **evp);
 312
 313 /* Prototypes for statetable processing. */
 314
 315 int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype,
 316                sctp_state_t state,
 317                struct sctp_endpoint *,
 318                struct sctp_association *asoc,
 319                void *event_arg,
 320                gfp_t gfp);
 321
 322 /* 2nd level prototypes */
 323 void sctp_generate_t3_rtx_event(unsigned long peer);
 324 void sctp_generate_heartbeat_event(unsigned long peer);
 325 void sctp_generate_reconf_event(unsigned long peer);
 326 void sctp_generate_proto_unreach_event(unsigned long peer);
 327
 328 void sctp_ootb_pkt_free(struct sctp_packet *packet);
 329
 330 struct sctp_association *sctp_unpack_cookie(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.  */
 341 extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES];
 342
 343
 344 /* Get the size of a DATA chunk payload. */
 345 static inline __u16 sctp_data_size(struct sctp_chunk *chunk)
 346 {
 347         __u16 size;
 348
 349         size = ntohs(chunk->chunk_hdr->length);
 350         size -= sizeof(struct sctp_data_chunk);
 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 SSNs */
 367 #define SSN_lt(a,b)             \
 368         (typecheck(__u16, a) && \
 369          typecheck(__u16, b) && \
 370          ((__s16)((a) - (b)) < 0))
 371
 372 /* ADDIP 3.1.1 */
 373 #define ADDIP_SERIAL_gte(a,b)   \
 374         (typecheck(__u32, a) && \
 375          typecheck(__u32, b) && \
 376          ((__s32)((b) - (a)) <= 0))
 377
 378 /* Check VTAG of the packet matches the sender's own tag. */
 379 static inline int
 380 sctp_vtag_verify(const struct sctp_chunk *chunk,
 381                  const struct sctp_association *asoc)
 382 {
 383         /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint
 384          * MUST ensure that the value in the Verification Tag field of
 385          * the received SCTP packet matches its own Tag. If the received
 386          * Verification Tag value does not match the receiver's own
 387          * tag value, the receiver shall silently discard the packet...
 388          */
 389         if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)
 390                 return 1;
 391
 392         return 0;
 393 }
 394
 395 /* Check VTAG of the packet matches the sender's own tag and the T bit is
 396  * not set, OR its peer's tag and the T bit is set in the Chunk Flags.
 397  */
 398 static inline int
 399 sctp_vtag_verify_either(const struct sctp_chunk *chunk,
 400                         const struct sctp_association *asoc)
 401 {
 402         /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41
 403          *
 404          * B) The receiver of a ABORT MUST accept the packet
 405          *    if the Verification Tag field of the packet matches its own tag
 406          *    and the T bit is not set
 407          *    OR
 408          *    it is set to its peer's tag and the T bit is set in the Chunk
 409          *    Flags.
 410          *    Otherwise, the receiver MUST silently discard the packet
 411          *    and take no further action.
 412          *
 413          * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet
 414          *    if the Verification Tag field of the packet matches its own tag
 415          *    and the T bit is not set
 416          *    OR
 417          *    it is set to its peer's tag and the T bit is set in the Chunk
 418          *    Flags.
 419          *    Otherwise, the receiver MUST silently discard the packet
 420          *    and take no further action.  An endpoint MUST ignore the
 421          *    SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
 422          */
 423         if ((!sctp_test_T_bit(chunk) &&
 424              (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) ||
 425             (sctp_test_T_bit(chunk) && asoc->c.peer_vtag &&
 426              (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) {
 427                 return 1;
 428         }
 429
 430         return 0;
 431 }
 432
 433 #endif /* __sctp_sm_h__ */