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, write to
  25  * the Free Software Foundation, 59 Temple Place - Suite 330,
  26  * Boston, MA 02111-1307, USA.
  27  *
  28  * Please send any bug reports or fixes you make to the
  29  * email addresses:
  30  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  31  *
  32  * Or submit a bug report through the following website:
  33  *    http://www.sf.net/projects/lksctp
  34  *
  35  * Written or modified by:
  36  *    La Monte H.P. Yarroll <piggy@acm.org>
  37  *    Karl Knutson <karl@athena.chicago.il.us>
  38  *    Xingang Guo <xingang.guo@intel.com>
  39  *    Jon Grimm <jgrimm@us.ibm.com>
  40  *    Dajiang Zhang <dajiang.zhang@nokia.com>
  41  *    Sridhar Samudrala <sri@us.ibm.com>
  42  *    Daisy Chang <daisyc@us.ibm.com>
  43  *    Ardelle Fan <ardelle.fan@intel.com>
  44  *    Kevin Gao <kevin.gao@intel.com>
  45  *
  46  * Any bugs reported given to us we will try to fix... any fixes shared will
  47  * be incorporated into the next SCTP release.
  48  */
  49
  50 #include <linux/types.h>
  51 #include <linux/compiler.h>
  52 #include <linux/slab.h>
  53 #include <linux/in.h>
  54 #include <net/sctp/command.h>
  55 #include <net/sctp/sctp.h>
  56
  57 #ifndef __sctp_sm_h__
  58 #define __sctp_sm_h__
  59
  60 /*
  61  * Possible values for the disposition are:
  62  */
  63 typedef enum {
  64         SCTP_DISPOSITION_DISCARD,        /* No further processing.  */
  65         SCTP_DISPOSITION_CONSUME,        /* Process return values normally.  */
  66         SCTP_DISPOSITION_NOMEM,          /* We ran out of memory--recover.  */
  67         SCTP_DISPOSITION_DELETE_TCB,     /* Close the association.  */
  68         SCTP_DISPOSITION_ABORT,          /* Close the association NOW.  */
  69         SCTP_DISPOSITION_VIOLATION,      /* The peer is misbehaving.  */
  70         SCTP_DISPOSITION_NOT_IMPL,       /* This entry is not implemented.  */
  71         SCTP_DISPOSITION_ERROR,          /* This is plain old user error.  */
  72         SCTP_DISPOSITION_BUG,            /* This is a bug.  */
  73 } sctp_disposition_t;
  74
  75 typedef struct {
  76         int name;
  77         int action;
  78 } sctp_sm_command_t;
  79
  80 typedef sctp_disposition_t (sctp_state_fn_t) (struct net *,
  81                                               const struct sctp_endpoint *,
  82                                               const struct sctp_association *,
  83                                               const sctp_subtype_t type,
  84                                               void *arg,
  85                                               sctp_cmd_seq_t *);
  86 typedef void (sctp_timer_event_t) (unsigned long);
  87 typedef struct {
  88         sctp_state_fn_t *fn;
  89         const char *name;
  90 } sctp_sm_table_entry_t;
  91
  92 /* A naming convention of "sctp_sf_xxx" applies to all the state functions
  93  * currently in use.
  94  */
  95
  96 /* Prototypes for generic state functions. */
  97 sctp_state_fn_t sctp_sf_not_impl;
  98 sctp_state_fn_t sctp_sf_bug;
  99
 100 /* Prototypes for gener timer state functions. */
 101 sctp_state_fn_t sctp_sf_timer_ignore;
 102
 103 /* Prototypes for chunk state functions. */
 104 sctp_state_fn_t sctp_sf_do_9_1_abort;
 105 sctp_state_fn_t sctp_sf_cookie_wait_abort;
 106 sctp_state_fn_t sctp_sf_cookie_echoed_abort;
 107 sctp_state_fn_t sctp_sf_shutdown_pending_abort;
 108 sctp_state_fn_t sctp_sf_shutdown_sent_abort;
 109 sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort;
 110 sctp_state_fn_t sctp_sf_do_5_1B_init;
 111 sctp_state_fn_t sctp_sf_do_5_1C_ack;
 112 sctp_state_fn_t sctp_sf_do_5_1D_ce;
 113 sctp_state_fn_t sctp_sf_do_5_1E_ca;
 114 sctp_state_fn_t sctp_sf_do_4_C;
 115 sctp_state_fn_t sctp_sf_eat_data_6_2;
 116 sctp_state_fn_t sctp_sf_eat_data_fast_4_4;
 117 sctp_state_fn_t sctp_sf_eat_sack_6_2;
 118 sctp_state_fn_t sctp_sf_operr_notify;
 119 sctp_state_fn_t sctp_sf_t1_init_timer_expire;
 120 sctp_state_fn_t sctp_sf_t1_cookie_timer_expire;
 121 sctp_state_fn_t sctp_sf_t2_timer_expire;
 122 sctp_state_fn_t sctp_sf_t4_timer_expire;
 123 sctp_state_fn_t sctp_sf_t5_timer_expire;
 124 sctp_state_fn_t sctp_sf_sendbeat_8_3;
 125 sctp_state_fn_t sctp_sf_beat_8_3;
 126 sctp_state_fn_t sctp_sf_backbeat_8_3;
 127 sctp_state_fn_t sctp_sf_do_9_2_final;
 128 sctp_state_fn_t sctp_sf_do_9_2_shutdown;
 129 sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn;
 130 sctp_state_fn_t sctp_sf_do_ecn_cwr;
 131 sctp_state_fn_t sctp_sf_do_ecne;
 132 sctp_state_fn_t sctp_sf_ootb;
 133 sctp_state_fn_t sctp_sf_pdiscard;
 134 sctp_state_fn_t sctp_sf_violation;
 135 sctp_state_fn_t sctp_sf_discard_chunk;
 136 sctp_state_fn_t sctp_sf_do_5_2_1_siminit;
 137 sctp_state_fn_t sctp_sf_do_5_2_2_dupinit;
 138 sctp_state_fn_t sctp_sf_do_5_2_3_initack;
 139 sctp_state_fn_t sctp_sf_do_5_2_4_dupcook;
 140 sctp_state_fn_t sctp_sf_unk_chunk;
 141 sctp_state_fn_t sctp_sf_do_8_5_1_E_sa;
 142 sctp_state_fn_t sctp_sf_cookie_echoed_err;
 143 sctp_state_fn_t sctp_sf_do_asconf;
 144 sctp_state_fn_t sctp_sf_do_asconf_ack;
 145 sctp_state_fn_t sctp_sf_do_9_2_reshutack;
 146 sctp_state_fn_t sctp_sf_eat_fwd_tsn;
 147 sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast;
 148 sctp_state_fn_t sctp_sf_eat_auth;
 149
 150 /* Prototypes for primitive event state functions.  */
 151 sctp_state_fn_t sctp_sf_do_prm_asoc;
 152 sctp_state_fn_t sctp_sf_do_prm_send;
 153 sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown;
 154 sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown;
 155 sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown;
 156 sctp_state_fn_t sctp_sf_do_9_1_prm_abort;
 157 sctp_state_fn_t sctp_sf_cookie_wait_prm_abort;
 158 sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort;
 159 sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort;
 160 sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort;
 161 sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort;
 162 sctp_state_fn_t sctp_sf_error_closed;
 163 sctp_state_fn_t sctp_sf_error_shutdown;
 164 sctp_state_fn_t sctp_sf_ignore_primitive;
 165 sctp_state_fn_t sctp_sf_do_prm_requestheartbeat;
 166 sctp_state_fn_t sctp_sf_do_prm_asconf;
 167
 168 /* Prototypes for other event state functions.  */
 169 sctp_state_fn_t sctp_sf_do_no_pending_tsn;
 170 sctp_state_fn_t sctp_sf_do_9_2_start_shutdown;
 171 sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack;
 172 sctp_state_fn_t sctp_sf_ignore_other;
 173 sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort;
 174
 175 /* Prototypes for timeout event state functions.  */
 176 sctp_state_fn_t sctp_sf_do_6_3_3_rtx;
 177 sctp_state_fn_t sctp_sf_do_6_2_sack;
 178 sctp_state_fn_t sctp_sf_autoclose_timer_expire;
 179
 180 /* Prototypes for utility support functions.  */
 181 __u8 sctp_get_chunk_type(struct sctp_chunk *chunk);
 182 const sctp_sm_table_entry_t *sctp_sm_lookup_event(struct net *,
 183                                             sctp_event_t,
 184                                             sctp_state_t,
 185                                             sctp_subtype_t);
 186 int sctp_chunk_iif(const struct sctp_chunk *);
 187 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *,
 188                                              struct sctp_chunk *,
 189                                              gfp_t gfp);
 190 __u32 sctp_generate_verification_tag(void);
 191 void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag);
 192
 193 /* Prototypes for chunk-building functions.  */
 194 struct sctp_chunk *sctp_make_init(const struct sctp_association *,
 195                              const struct sctp_bind_addr *,
 196                              gfp_t gfp, int vparam_len);
 197 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *,
 198                                  const struct sctp_chunk *,
 199                                  const gfp_t gfp,
 200                                  const int unkparam_len);
 201 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *,
 202                                     const struct sctp_chunk *);
 203 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *,
 204                                    const struct sctp_chunk *);
 205 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *,
 206                                  const __u32 lowest_tsn,
 207                                  const struct sctp_chunk *);
 208 struct sctp_chunk * sctp_make_datafrag_empty(struct sctp_association *,
 209                                         const struct sctp_sndrcvinfo *sinfo,
 210                                         int len, const __u8 flags,
 211                                         __u16 ssn);
 212 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *,
 213                                   const __u32);
 214 struct sctp_chunk *sctp_make_sack(const struct sctp_association *);
 215 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
 216                                       const struct sctp_chunk *chunk);
 217 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
 218                                           const struct sctp_chunk *);
 219 struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *,
 220                                           const struct sctp_chunk *);
 221 void sctp_init_cause(struct sctp_chunk *, __be16 cause, size_t);
 222 struct sctp_chunk *sctp_make_abort(const struct sctp_association *,
 223                               const struct sctp_chunk *,
 224                               const size_t hint);
 225 struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *,
 226                                       const struct sctp_chunk *,
 227                                       __u32 tsn);
 228 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *,
 229                                         const struct msghdr *, size_t msg_len);
 230 struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *,
 231                                    const struct sctp_chunk *,
 232                                    const __u8 *,
 233                                    const size_t );
 234 struct sctp_chunk *sctp_make_violation_paramlen(const struct sctp_association *,
 235                                    const struct sctp_chunk *,
 236                                    struct sctp_paramhdr *);
 237 struct sctp_chunk *sctp_make_violation_max_retrans(const struct sctp_association *,
 238                                                    const struct sctp_chunk *);
 239 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *,
 240                                   const struct sctp_transport *);
 241 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *,
 242                                       const struct sctp_chunk *,
 243                                       const void *payload,
 244                                       const size_t paylen);
 245 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *,
 246                                  const struct sctp_chunk *chunk,
 247                                  __be16 cause_code,
 248                                  const void *payload,
 249                                  size_t paylen,
 250                                  size_t reserve_tail);
 251
 252 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *,
 253                                               union sctp_addr *,
 254                                               struct sockaddr *,
 255                                               int, __be16);
 256 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
 257                                              union sctp_addr *addr);
 258 int sctp_verify_asconf(const struct sctp_association *asoc,
 259                        struct sctp_paramhdr *param_hdr, void *chunk_end,
 260                        struct sctp_paramhdr **errp);
 261 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
 262                                        struct sctp_chunk *asconf);
 263 int sctp_process_asconf_ack(struct sctp_association *asoc,
 264                             struct sctp_chunk *asconf_ack);
 265 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
 266                                     __u32 new_cum_tsn, size_t nstreams,
 267                                     struct sctp_fwdtsn_skip *skiplist);
 268 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc);
 269
 270 void sctp_chunk_assign_tsn(struct sctp_chunk *);
 271 void sctp_chunk_assign_ssn(struct sctp_chunk *);
 272
 273 /* Prototypes for statetable processing. */
 274
 275 int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype,
 276                sctp_state_t state,
 277                struct sctp_endpoint *,
 278                struct sctp_association *asoc,
 279                void *event_arg,
 280                gfp_t gfp);
 281
 282 /* 2nd level prototypes */
 283 void sctp_generate_t3_rtx_event(unsigned long peer);
 284 void sctp_generate_heartbeat_event(unsigned long peer);
 285 void sctp_generate_proto_unreach_event(unsigned long peer);
 286
 287 void sctp_ootb_pkt_free(struct sctp_packet *);
 288
 289 struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *,
 290                                        const struct sctp_association *,
 291                                        struct sctp_chunk *,
 292                                        gfp_t gfp, int *err,
 293                                        struct sctp_chunk **err_chk_p);
 294 int sctp_addip_addr_config(struct sctp_association *, sctp_param_t,
 295                            struct sockaddr_storage*, int);
 296
 297 /* 3rd level prototypes */
 298 __u32 sctp_generate_tag(const struct sctp_endpoint *);
 299 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
 300
 301 /* Extern declarations for major data structures.  */
 302 extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES];
 303
 304
 305 /* Get the size of a DATA chunk payload. */
 306 static inline __u16 sctp_data_size(struct sctp_chunk *chunk)
 307 {
 308         __u16 size;
 309
 310         size = ntohs(chunk->chunk_hdr->length);
 311         size -= sizeof(sctp_data_chunk_t);
 312
 313         return size;
 314 }
 315
 316 /* Compare two TSNs */
 317
 318 /* RFC 1982 - Serial Number Arithmetic
 319  *
 320  * 2. Comparison
 321  *  Then, s1 is said to be equal to s2 if and only if i1 is equal to i2,
 322  *  in all other cases, s1 is not equal to s2.
 323  *
 324  * s1 is said to be less than s2 if, and only if, s1 is not equal to s2,
 325  * and
 326  *
 327  *      (i1 < i2 and i2 - i1 < 2^(SERIAL_BITS - 1)) or
 328  *      (i1 > i2 and i1 - i2 > 2^(SERIAL_BITS - 1))
 329  *
 330  * s1 is said to be greater than s2 if, and only if, s1 is not equal to
 331  * s2, and
 332  *
 333  *      (i1 < i2 and i2 - i1 > 2^(SERIAL_BITS - 1)) or
 334  *      (i1 > i2 and i1 - i2 < 2^(SERIAL_BITS - 1))
 335  */
 336
 337 /*
 338  * RFC 2960
 339  *  1.6 Serial Number Arithmetic
 340  *
 341  * Comparisons and arithmetic on TSNs in this document SHOULD use Serial
 342  * Number Arithmetic as defined in [RFC1982] where SERIAL_BITS = 32.
 343  */
 344
 345 enum {
 346         TSN_SIGN_BIT = (1<<31)
 347 };
 348
 349 static inline int TSN_lt(__u32 s, __u32 t)
 350 {
 351         return ((s) - (t)) & TSN_SIGN_BIT;
 352 }
 353
 354 static inline int TSN_lte(__u32 s, __u32 t)
 355 {
 356         return ((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT);
 357 }
 358
 359 /* Compare two SSNs */
 360
 361 /*
 362  * RFC 2960
 363  *  1.6 Serial Number Arithmetic
 364  *
 365  * Comparisons and arithmetic on Stream Sequence Numbers in this document
 366  * SHOULD use Serial Number Arithmetic as defined in [RFC1982] where
 367  * SERIAL_BITS = 16.
 368  */
 369 enum {
 370         SSN_SIGN_BIT = (1<<15)
 371 };
 372
 373 static inline int SSN_lt(__u16 s, __u16 t)
 374 {
 375         return ((s) - (t)) & SSN_SIGN_BIT;
 376 }
 377
 378 static inline int SSN_lte(__u16 s, __u16 t)
 379 {
 380         return ((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT);
 381 }
 382
 383 /*
 384  * ADDIP 3.1.1
 385  * The valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). Serial
 386  * Numbers wrap back to 0 after reaching 4294967295.
 387  */
 388 enum {
 389         ADDIP_SERIAL_SIGN_BIT = (1<<31)
 390 };
 391
 392 static inline int ADDIP_SERIAL_gte(__u16 s, __u16 t)
 393 {
 394         return ((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT);
 395 }
 396
 397 /* Check VTAG of the packet matches the sender's own tag. */
 398 static inline int
 399 sctp_vtag_verify(const struct sctp_chunk *chunk,
 400                  const struct sctp_association *asoc)
 401 {
 402         /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint
 403          * MUST ensure that the value in the Verification Tag field of
 404          * the received SCTP packet matches its own Tag. If the received
 405          * Verification Tag value does not match the receiver's own
 406          * tag value, the receiver shall silently discard the packet...
 407          */
 408         if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)
 409                 return 1;
 410
 411         return 0;
 412 }
 413
 414 /* Check VTAG of the packet matches the sender's own tag and the T bit is
 415  * not set, OR its peer's tag and the T bit is set in the Chunk Flags.
 416  */
 417 static inline int
 418 sctp_vtag_verify_either(const struct sctp_chunk *chunk,
 419                         const struct sctp_association *asoc)
 420 {
 421         /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41
 422          *
 423          * B) The receiver of a ABORT MUST accept the packet
 424          *    if the Verification Tag field of the packet matches its own tag
 425          *    and the T bit is not set
 426          *    OR
 427          *    it is set to its peer's tag and the T bit is set in the Chunk
 428          *    Flags.
 429          *    Otherwise, the receiver MUST silently discard the packet
 430          *    and take no further action.
 431          *
 432          * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet
 433          *    if the Verification Tag field of the packet matches its own tag
 434          *    and the T bit is not set
 435          *    OR
 436          *    it is set to its peer's tag and the T bit is set in the Chunk
 437          *    Flags.
 438          *    Otherwise, the receiver MUST silently discard the packet
 439          *    and take no further action.  An endpoint MUST ignore the
 440          *    SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
 441          */
 442         if ((!sctp_test_T_bit(chunk) &&
 443              (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) ||
 444             (sctp_test_T_bit(chunk) && asoc->c.peer_vtag &&
 445              (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) {
 446                 return 1;
 447         }
 448
 449         return 0;
 450 }
 451
 452 #endif /* __sctp_sm_h__ */