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