net/sctp/sm.h

0001 /* SPDX-License-Identifier: GPL-2.0-or-later */
0002 /* SCTP kernel implementation
0003  * (C) Copyright IBM Corp. 2001, 2004
0004  * Copyright (c) 1999-2000 Cisco, Inc.
0005  * Copyright (c) 1999-2001 Motorola, Inc.
0006  * Copyright (c) 2001 Intel Corp.
0007  *
0008  * This file is part of the SCTP kernel implementation
0009  *
0010  * These are definitions needed by the state machine.
0011  *
0012  * Please send any bug reports or fixes you make to the
0013  * email addresses:
0014  *    lksctp developers <linux-sctp@vger.kernel.org>
0015  *
0016  * Written or modified by:
0017  *    La Monte H.P. Yarroll <piggy@acm.org>
0018  *    Karl Knutson <karl@athena.chicago.il.us>
0019  *    Xingang Guo <xingang.guo@intel.com>
0020  *    Jon Grimm <jgrimm@us.ibm.com>
0021  *    Dajiang Zhang <dajiang.zhang@nokia.com>
0022  *    Sridhar Samudrala <sri@us.ibm.com>
0023  *    Daisy Chang <daisyc@us.ibm.com>
0024  *    Ardelle Fan <ardelle.fan@intel.com>
0025  *    Kevin Gao <kevin.gao@intel.com>
0026  */
0027
0028 #include <linux/types.h>
0029 #include <linux/compiler.h>
0030 #include <linux/slab.h>
0031 #include <linux/in.h>
0032 #include <net/sctp/command.h>
0033 #include <net/sctp/sctp.h>
0034
0035 #ifndef __sctp_sm_h__
0036 #define __sctp_sm_h__
0037
0038 /*
0039  * Possible values for the disposition are:
0040  */
0041 enum sctp_disposition {
0042     SCTP_DISPOSITION_DISCARD,    /* No further processing.  */
0043     SCTP_DISPOSITION_CONSUME,    /* Process return values normally.  */
0044     SCTP_DISPOSITION_NOMEM,      /* We ran out of memory--recover.  */
0045     SCTP_DISPOSITION_DELETE_TCB,     /* Close the association.  */
0046     SCTP_DISPOSITION_ABORT,      /* Close the association NOW.  */
0047     SCTP_DISPOSITION_VIOLATION,  /* The peer is misbehaving.  */
0048     SCTP_DISPOSITION_NOT_IMPL,   /* This entry is not implemented.  */
0049     SCTP_DISPOSITION_ERROR,      /* This is plain old user error.  */
0050     SCTP_DISPOSITION_BUG,        /* This is a bug.  */
0051 };
0052
0053 typedef enum sctp_disposition (sctp_state_fn_t) (
0054                     struct net *net,
0055                     const struct sctp_endpoint *ep,
0056                     const struct sctp_association *asoc,
0057                     const union sctp_subtype type,
0058                     void *arg,
0059                     struct sctp_cmd_seq *commands);
0060 typedef void (sctp_timer_event_t) (struct timer_list *);
0061 struct sctp_sm_table_entry {
0062     sctp_state_fn_t *fn;
0063     const char *name;
0064 };
0065
0066 /* A naming convention of "sctp_sf_xxx" applies to all the state functions
0067  * currently in use.
0068  */
0069
0070 /* Prototypes for generic state functions. */
0071 sctp_state_fn_t sctp_sf_not_impl;
0072 sctp_state_fn_t sctp_sf_bug;
0073
0074 /* Prototypes for gener timer state functions. */
0075 sctp_state_fn_t sctp_sf_timer_ignore;
0076
0077 /* Prototypes for chunk state functions. */
0078 sctp_state_fn_t sctp_sf_do_9_1_abort;
0079 sctp_state_fn_t sctp_sf_cookie_wait_abort;
0080 sctp_state_fn_t sctp_sf_cookie_echoed_abort;
0081 sctp_state_fn_t sctp_sf_shutdown_pending_abort;
0082 sctp_state_fn_t sctp_sf_shutdown_sent_abort;
0083 sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort;
0084 sctp_state_fn_t sctp_sf_do_5_1B_init;
0085 sctp_state_fn_t sctp_sf_do_5_1C_ack;
0086 sctp_state_fn_t sctp_sf_do_5_1D_ce;
0087 sctp_state_fn_t sctp_sf_do_5_1E_ca;
0088 sctp_state_fn_t sctp_sf_do_4_C;
0089 sctp_state_fn_t sctp_sf_eat_data_6_2;
0090 sctp_state_fn_t sctp_sf_eat_data_fast_4_4;
0091 sctp_state_fn_t sctp_sf_eat_sack_6_2;
0092 sctp_state_fn_t sctp_sf_operr_notify;
0093 sctp_state_fn_t sctp_sf_t1_init_timer_expire;
0094 sctp_state_fn_t sctp_sf_t1_cookie_timer_expire;
0095 sctp_state_fn_t sctp_sf_t2_timer_expire;
0096 sctp_state_fn_t sctp_sf_t4_timer_expire;
0097 sctp_state_fn_t sctp_sf_t5_timer_expire;
0098 sctp_state_fn_t sctp_sf_sendbeat_8_3;
0099 sctp_state_fn_t sctp_sf_beat_8_3;
0100 sctp_state_fn_t sctp_sf_backbeat_8_3;
0101 sctp_state_fn_t sctp_sf_do_9_2_final;
0102 sctp_state_fn_t sctp_sf_do_9_2_shutdown;
0103 sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn;
0104 sctp_state_fn_t sctp_sf_do_ecn_cwr;
0105 sctp_state_fn_t sctp_sf_do_ecne;
0106 sctp_state_fn_t sctp_sf_ootb;
0107 sctp_state_fn_t sctp_sf_pdiscard;
0108 sctp_state_fn_t sctp_sf_violation;
0109 sctp_state_fn_t sctp_sf_discard_chunk;
0110 sctp_state_fn_t sctp_sf_do_5_2_1_siminit;
0111 sctp_state_fn_t sctp_sf_do_5_2_2_dupinit;
0112 sctp_state_fn_t sctp_sf_do_5_2_3_initack;
0113 sctp_state_fn_t sctp_sf_do_5_2_4_dupcook;
0114 sctp_state_fn_t sctp_sf_unk_chunk;
0115 sctp_state_fn_t sctp_sf_do_8_5_1_E_sa;
0116 sctp_state_fn_t sctp_sf_cookie_echoed_err;
0117 sctp_state_fn_t sctp_sf_do_asconf;
0118 sctp_state_fn_t sctp_sf_do_asconf_ack;
0119 sctp_state_fn_t sctp_sf_do_reconf;
0120 sctp_state_fn_t sctp_sf_do_9_2_reshutack;
0121 sctp_state_fn_t sctp_sf_eat_fwd_tsn;
0122 sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast;
0123 sctp_state_fn_t sctp_sf_eat_auth;
0124
0125 /* Prototypes for primitive event state functions.  */
0126 sctp_state_fn_t sctp_sf_do_prm_asoc;
0127 sctp_state_fn_t sctp_sf_do_prm_send;
0128 sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown;
0129 sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown;
0130 sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown;
0131 sctp_state_fn_t sctp_sf_do_9_1_prm_abort;
0132 sctp_state_fn_t sctp_sf_cookie_wait_prm_abort;
0133 sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort;
0134 sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort;
0135 sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort;
0136 sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort;
0137 sctp_state_fn_t sctp_sf_error_closed;
0138 sctp_state_fn_t sctp_sf_error_shutdown;
0139 sctp_state_fn_t sctp_sf_ignore_primitive;
0140 sctp_state_fn_t sctp_sf_do_prm_requestheartbeat;
0141 sctp_state_fn_t sctp_sf_do_prm_asconf;
0142 sctp_state_fn_t sctp_sf_do_prm_reconf;
0143
0144 /* Prototypes for other event state functions.  */
0145 sctp_state_fn_t sctp_sf_do_no_pending_tsn;
0146 sctp_state_fn_t sctp_sf_do_9_2_start_shutdown;
0147 sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack;
0148 sctp_state_fn_t sctp_sf_ignore_other;
0149 sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort;
0150
0151 /* Prototypes for timeout event state functions.  */
0152 sctp_state_fn_t sctp_sf_do_6_3_3_rtx;
0153 sctp_state_fn_t sctp_sf_send_reconf;
0154 sctp_state_fn_t sctp_sf_send_probe;
0155 sctp_state_fn_t sctp_sf_do_6_2_sack;
0156 sctp_state_fn_t sctp_sf_autoclose_timer_expire;
0157
0158 /* Prototypes for utility support functions.  */
0159 __u8 sctp_get_chunk_type(struct sctp_chunk *chunk);
0160 const struct sctp_sm_table_entry *sctp_sm_lookup_event(
0161                     struct net *net,
0162                     enum sctp_event_type event_type,
0163                     enum sctp_state state,
0164                     union sctp_subtype event_subtype);
0165 int sctp_chunk_iif(const struct sctp_chunk *);
0166 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *,
0167                          struct sctp_chunk *,
0168                          gfp_t gfp);
0169 __u32 sctp_generate_verification_tag(void);
0170 void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag);
0171
0172 /* Prototypes for chunk-building functions.  */
0173 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
0174                   const struct sctp_bind_addr *bp,
0175                   gfp_t gfp, int vparam_len);
0176 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
0177                       const struct sctp_chunk *chunk,
0178                       const gfp_t gfp, const int unkparam_len);
0179 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
0180                      const struct sctp_chunk *chunk);
0181 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
0182                     const struct sctp_chunk *chunk);
0183 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
0184                  const __u32 lowest_tsn,
0185                  const struct sctp_chunk *chunk);
0186 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
0187                    __u8 flags, int paylen, gfp_t gfp);
0188 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
0189                      __u32 new_cum_tsn, size_t nstreams,
0190                      struct sctp_ifwdtsn_skip *skiplist);
0191 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
0192                         const struct sctp_sndrcvinfo *sinfo,
0193                         int len, __u8 flags, gfp_t gfp);
0194 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
0195                   const __u32 lowest_tsn);
0196 struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc);
0197 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
0198                       const struct sctp_chunk *chunk);
0199 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
0200                       const struct sctp_chunk *chunk);
0201 struct sctp_chunk *sctp_make_shutdown_complete(
0202                     const struct sctp_association *asoc,
0203                     const struct sctp_chunk *chunk);
0204 int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause, size_t paylen);
0205 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
0206                    const struct sctp_chunk *chunk,
0207                    const size_t hint);
0208 struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *asoc,
0209                        const struct sctp_chunk *chunk,
0210                        __u32 tsn);
0211 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
0212                     struct msghdr *msg, size_t msg_len);
0213 struct sctp_chunk *sctp_make_abort_violation(
0214                     const struct sctp_association *asoc,
0215                     const struct sctp_chunk *chunk,
0216                     const __u8 *payload,
0217                     const size_t paylen);
0218 struct sctp_chunk *sctp_make_violation_paramlen(
0219                     const struct sctp_association *asoc,
0220                     const struct sctp_chunk *chunk,
0221                     struct sctp_paramhdr *param);
0222 struct sctp_chunk *sctp_make_violation_max_retrans(
0223                     const struct sctp_association *asoc,
0224                     const struct sctp_chunk *chunk);
0225 struct sctp_chunk *sctp_make_new_encap_port(
0226                     const struct sctp_association *asoc,
0227                     const struct sctp_chunk *chunk);
0228 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
0229                        const struct sctp_transport *transport,
0230                        __u32 probe_size);
0231 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
0232                        const struct sctp_chunk *chunk,
0233                        const void *payload,
0234                        const size_t paylen);
0235 struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len);
0236 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
0237                       const struct sctp_chunk *chunk,
0238                       __be16 cause_code, const void *payload,
0239                       size_t paylen, size_t reserve_tail);
0240
0241 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
0242                           union sctp_addr *laddr,
0243                           struct sockaddr *addrs,
0244                           int addrcnt, __be16 flags);
0245 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
0246                          union sctp_addr *addr);
0247 bool sctp_verify_asconf(const struct sctp_association *asoc,
0248             struct sctp_chunk *chunk, bool addr_param_needed,
0249             struct sctp_paramhdr **errp);
0250 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
0251                        struct sctp_chunk *asconf);
0252 int sctp_process_asconf_ack(struct sctp_association *asoc,
0253                 struct sctp_chunk *asconf_ack);
0254 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
0255                     __u32 new_cum_tsn, size_t nstreams,
0256                     struct sctp_fwdtsn_skip *skiplist);
0257 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
0258                   __u16 key_id);
0259 struct sctp_chunk *sctp_make_strreset_req(const struct sctp_association *asoc,
0260                       __u16 stream_num, __be16 *stream_list,
0261                       bool out, bool in);
0262 struct sctp_chunk *sctp_make_strreset_tsnreq(
0263                     const struct sctp_association *asoc);
0264 struct sctp_chunk *sctp_make_strreset_addstrm(
0265                     const struct sctp_association *asoc,
0266                     __u16 out, __u16 in);
0267 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
0268                        __u32 result, __u32 sn);
0269 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
0270                           __u32 result, __u32 sn,
0271                           __u32 sender_tsn,
0272                           __u32 receiver_tsn);
0273 bool sctp_verify_reconf(const struct sctp_association *asoc,
0274             struct sctp_chunk *chunk,
0275             struct sctp_paramhdr **errp);
0276 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk);
0277 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk);
0278
0279 /* Prototypes for stream-processing functions.  */
0280 struct sctp_chunk *sctp_process_strreset_outreq(
0281                 struct sctp_association *asoc,
0282                 union sctp_params param,
0283                 struct sctp_ulpevent **evp);
0284 struct sctp_chunk *sctp_process_strreset_inreq(
0285                 struct sctp_association *asoc,
0286                 union sctp_params param,
0287                 struct sctp_ulpevent **evp);
0288 struct sctp_chunk *sctp_process_strreset_tsnreq(
0289                 struct sctp_association *asoc,
0290                 union sctp_params param,
0291                 struct sctp_ulpevent **evp);
0292 struct sctp_chunk *sctp_process_strreset_addstrm_out(
0293                 struct sctp_association *asoc,
0294                 union sctp_params param,
0295                 struct sctp_ulpevent **evp);
0296 struct sctp_chunk *sctp_process_strreset_addstrm_in(
0297                 struct sctp_association *asoc,
0298                 union sctp_params param,
0299                 struct sctp_ulpevent **evp);
0300 struct sctp_chunk *sctp_process_strreset_resp(
0301                 struct sctp_association *asoc,
0302                 union sctp_params param,
0303                 struct sctp_ulpevent **evp);
0304
0305 /* Prototypes for statetable processing. */
0306
0307 int sctp_do_sm(struct net *net, enum sctp_event_type event_type,
0308            union sctp_subtype subtype, enum sctp_state state,
0309            struct sctp_endpoint *ep, struct sctp_association *asoc,
0310            void *event_arg, gfp_t gfp);
0311
0312 /* 2nd level prototypes */
0313 void sctp_generate_t3_rtx_event(struct timer_list *t);
0314 void sctp_generate_heartbeat_event(struct timer_list *t);
0315 void sctp_generate_reconf_event(struct timer_list *t);
0316 void sctp_generate_probe_event(struct timer_list *t);
0317 void sctp_generate_proto_unreach_event(struct timer_list *t);
0318
0319 void sctp_ootb_pkt_free(struct sctp_packet *packet);
0320
0321 struct sctp_association *sctp_unpack_cookie(
0322                     const struct sctp_endpoint *ep,
0323                     const struct sctp_association *asoc,
0324                     struct sctp_chunk *chunk,
0325                     gfp_t gfp, int *err,
0326                     struct sctp_chunk **err_chk_p);
0327
0328 /* 3rd level prototypes */
0329 __u32 sctp_generate_tag(const struct sctp_endpoint *ep);
0330 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep);
0331
0332 /* Extern declarations for major data structures.  */
0333 extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES];
0334
0335
0336 /* Get the size of a DATA chunk payload. */
0337 static inline __u16 sctp_data_size(struct sctp_chunk *chunk)
0338 {
0339     __u16 size;
0340
0341     size = ntohs(chunk->chunk_hdr->length);
0342     size -= sctp_datachk_len(&chunk->asoc->stream);
0343
0344     return size;
0345 }
0346
0347 /* Compare two TSNs */
0348 #define TSN_lt(a,b) \
0349     (typecheck(__u32, a) && \
0350      typecheck(__u32, b) && \
0351      ((__s32)((a) - (b)) < 0))
0352
0353 #define TSN_lte(a,b)    \
0354     (typecheck(__u32, a) && \
0355      typecheck(__u32, b) && \
0356      ((__s32)((a) - (b)) <= 0))
0357
0358 /* Compare two MIDs */
0359 #define MID_lt(a, b)    \
0360     (typecheck(__u32, a) && \
0361      typecheck(__u32, b) && \
0362      ((__s32)((a) - (b)) < 0))
0363
0364 /* Compare two SSNs */
0365 #define SSN_lt(a,b)     \
0366     (typecheck(__u16, a) && \
0367      typecheck(__u16, b) && \
0368      ((__s16)((a) - (b)) < 0))
0369
0370 /* ADDIP 3.1.1 */
0371 #define ADDIP_SERIAL_gte(a,b)   \
0372     (typecheck(__u32, a) && \
0373      typecheck(__u32, b) && \
0374      ((__s32)((b) - (a)) <= 0))
0375
0376 /* Check VTAG of the packet matches the sender's own tag. */
0377 static inline int
0378 sctp_vtag_verify(const struct sctp_chunk *chunk,
0379          const struct sctp_association *asoc)
0380 {
0381     /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint
0382      * MUST ensure that the value in the Verification Tag field of
0383      * the received SCTP packet matches its own Tag. If the received
0384      * Verification Tag value does not match the receiver's own
0385      * tag value, the receiver shall silently discard the packet...
0386      */
0387     if (ntohl(chunk->sctp_hdr->vtag) != asoc->c.my_vtag)
0388         return 0;
0389
0390     chunk->transport->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port;
0391     return 1;
0392 }
0393
0394 /* Check VTAG of the packet matches the sender's own tag and the T bit is
0395  * not set, OR its peer's tag and the T bit is set in the Chunk Flags.
0396  */
0397 static inline int
0398 sctp_vtag_verify_either(const struct sctp_chunk *chunk,
0399             const struct sctp_association *asoc)
0400 {
0401         /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41
0402      *
0403      * B) The receiver of a ABORT MUST accept the packet
0404      *    if the Verification Tag field of the packet matches its own tag
0405      *    and the T bit is not set
0406      *    OR
0407      *    it is set to its peer's tag and the T bit is set in the Chunk
0408      *    Flags.
0409      *    Otherwise, the receiver MUST silently discard the packet
0410      *    and take no further action.
0411      *
0412      * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet
0413      *    if the Verification Tag field of the packet matches its own tag
0414      *    and the T bit is not set
0415      *    OR
0416      *    it is set to its peer's tag and the T bit is set in the Chunk
0417      *    Flags.
0418      *    Otherwise, the receiver MUST silently discard the packet
0419      *    and take no further action.  An endpoint MUST ignore the
0420      *    SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
0421      */
0422         if ((!sctp_test_T_bit(chunk) &&
0423              (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) ||
0424         (sctp_test_T_bit(chunk) && asoc->c.peer_vtag &&
0425          (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) {
0426                 return 1;
0427     }
0428
0429     return 0;
0430 }
0431
0432 #endif /* __sctp_sm_h__ */