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/* SCTP kernel reference Implementation

 * (C) Copyright IBM Corp. 2001, 2003

 * Copyright (c) 1999-2000 Cisco, Inc.

 * Copyright (c) 1999-2001 Motorola, Inc.

 * Copyright (c) 2001 Intel Corp.

 *

 * This file is part of the SCTP kernel reference Implementation

 *

 * These are definitions needed by the state machine.

 *

 * The SCTP reference implementation is free software;

 * you can redistribute it and/or modify it under the terms of

 * the GNU General Public License as published by

 * the Free Software Foundation; either version 2, or (at your option)

 * any later version.

 *

 * The SCTP reference implementation is distributed in the hope that it

 * will be useful, but WITHOUT ANY WARRANTY; without even the implied

 *                 ************************

 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

 * See the GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with GNU CC; see the file COPYING.  If not, write to

 * the Free Software Foundation, 59 Temple Place - Suite 330,

 * Boston, MA 02111-1307, USA.

 *

 * Please send any bug reports or fixes you make to the

 * email addresses:

 *    lksctp developers <lksctp-developers@lists.sourceforge.net>

 *

 * Or submit a bug report through the following website:

 *    http://www.sf.net/projects/lksctp

 *

 * Written or modified by:

 *    La Monte H.P. Yarroll <piggy@acm.org>

 *    Karl Knutson <karl@athena.chicago.il.us>

 *    Xingang Guo <xingang.guo@intel.com>

 *    Jon Grimm <jgrimm@us.ibm.com>

 *    Dajiang Zhang <dajiang.zhang@nokia.com>

 *    Sridhar Samudrala <sri@us.ibm.com>

 *    Daisy Chang <daisyc@us.ibm.com>

 *    Ardelle Fan <ardelle.fan@intel.com>

 *    Kevin Gao <kevin.gao@intel.com>

 *

 * Any bugs reported given to us we will try to fix... any fixes shared will

 * be incorporated into the next SCTP release.

 */

#include <linux/types.h>

#include <linux/compiler.h>

#include <linux/slab.h>

#include <linux/in.h>

#include <net/sctp/command.h>

#include <net/sctp/sctp.h>

#ifndef __sctp_sm_h__

#define __sctp_sm_h__

/*

 * Possible values for the disposition are:

 */

typedef enum {

        SCTP_DISPOSITION_DISCARD,        /* No further processing.  */

        SCTP_DISPOSITION_CONSUME,        /* Process return values normally.  */

        SCTP_DISPOSITION_NOMEM,          /* We ran out of memory--recover.  */

        SCTP_DISPOSITION_DELETE_TCB,     /* Close the association.  */

        SCTP_DISPOSITION_ABORT,          /* Close the association NOW.  */

        SCTP_DISPOSITION_VIOLATION,      /* The peer is misbehaving.  */

        SCTP_DISPOSITION_NOT_IMPL,       /* This entry is not implemented.  */

        SCTP_DISPOSITION_ERROR,          /* This is plain old user error.  */

        SCTP_DISPOSITION_BUG,            /* This is a bug.  */

} sctp_disposition_t;

typedef struct {

        int name;

        int action;

} sctp_sm_command_t;

typedef sctp_disposition_t (sctp_state_fn_t) (const struct sctp_endpoint *,

                                              const struct sctp_association *,

                                              const sctp_subtype_t type,

                                              void *arg,

                                              sctp_cmd_seq_t *);

typedef void (sctp_timer_event_t) (unsigned long);

typedef struct {

        sctp_state_fn_t *fn;

        const char *name;

} sctp_sm_table_entry_t;

/* A naming convention of "sctp_sf_xxx" applies to all the state functions

 * currently in use.

 */

/* Prototypes for generic state functions. */

sctp_state_fn_t sctp_sf_not_impl;

sctp_state_fn_t sctp_sf_bug;

/* Prototypes for gener timer state functions. */

sctp_state_fn_t sctp_sf_timer_ignore;

/* Prototypes for chunk state functions. */

sctp_state_fn_t sctp_sf_do_9_1_abort;

sctp_state_fn_t sctp_sf_cookie_wait_abort;

sctp_state_fn_t sctp_sf_cookie_echoed_abort;

sctp_state_fn_t sctp_sf_shutdown_pending_abort;

sctp_state_fn_t sctp_sf_shutdown_sent_abort;

sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort;

sctp_state_fn_t sctp_sf_do_5_1B_init;

sctp_state_fn_t sctp_sf_do_5_1C_ack;

sctp_state_fn_t sctp_sf_do_5_1D_ce;

sctp_state_fn_t sctp_sf_do_5_1E_ca;

sctp_state_fn_t sctp_sf_do_4_C;

sctp_state_fn_t sctp_sf_eat_data_6_2;

sctp_state_fn_t sctp_sf_eat_data_fast_4_4;

sctp_state_fn_t sctp_sf_eat_sack_6_2;

sctp_state_fn_t sctp_sf_tabort_8_4_8;

sctp_state_fn_t sctp_sf_operr_notify;

sctp_state_fn_t sctp_sf_t1_timer_expire;

sctp_state_fn_t sctp_sf_t2_timer_expire;

sctp_state_fn_t sctp_sf_t4_timer_expire;

sctp_state_fn_t sctp_sf_t5_timer_expire;

sctp_state_fn_t sctp_sf_sendbeat_8_3;

sctp_state_fn_t sctp_sf_beat_8_3;

sctp_state_fn_t sctp_sf_backbeat_8_3;

sctp_state_fn_t sctp_sf_do_9_2_final;

sctp_state_fn_t sctp_sf_do_9_2_shutdown;

sctp_state_fn_t sctp_sf_do_ecn_cwr;

sctp_state_fn_t sctp_sf_do_ecne;

sctp_state_fn_t sctp_sf_ootb;

sctp_state_fn_t sctp_sf_shut_8_4_5;

sctp_state_fn_t sctp_sf_pdiscard;

sctp_state_fn_t sctp_sf_violation;

sctp_state_fn_t sctp_sf_discard_chunk;

sctp_state_fn_t sctp_sf_do_5_2_1_siminit;

sctp_state_fn_t sctp_sf_do_5_2_2_dupinit;

sctp_state_fn_t sctp_sf_do_5_2_4_dupcook;

sctp_state_fn_t sctp_sf_unk_chunk;

sctp_state_fn_t sctp_sf_do_8_5_1_E_sa;

sctp_state_fn_t sctp_sf_cookie_echoed_err;

sctp_state_fn_t sctp_sf_do_5_2_6_stale;

sctp_state_fn_t sctp_sf_do_asconf;

sctp_state_fn_t sctp_sf_do_asconf_ack;

/* Prototypes for primitive event state functions.  */

sctp_state_fn_t sctp_sf_do_prm_asoc;

sctp_state_fn_t sctp_sf_do_prm_send;

sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown;

sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown;

sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown;

sctp_state_fn_t sctp_sf_do_9_1_prm_abort;

sctp_state_fn_t sctp_sf_cookie_wait_prm_abort;

sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort;

sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort;

sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort;

sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort;

sctp_state_fn_t sctp_sf_error_closed;

sctp_state_fn_t sctp_sf_error_shutdown;

sctp_state_fn_t sctp_sf_ignore_primitive;

sctp_state_fn_t sctp_sf_do_prm_requestheartbeat;

sctp_state_fn_t sctp_sf_do_prm_asconf;

/* Prototypes for other event state functions.  */

sctp_state_fn_t sctp_sf_do_9_2_start_shutdown;

sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack;

sctp_state_fn_t sctp_sf_ignore_other;

/* Prototypes for timeout event state functions.  */

sctp_state_fn_t sctp_sf_do_6_3_3_rtx;

sctp_state_fn_t sctp_sf_do_6_2_sack;

sctp_state_fn_t sctp_sf_autoclose_timer_expire;

/* These are state functions which are either obsolete or not in use yet.

 * If any of these functions needs to be revived, it should be renamed with

 * the "sctp_sf_xxx" prefix, and be moved to the above prototype groups.

 */

/* Prototypes for chunk state functions.  Not in use. */

sctp_state_fn_t sctp_sf_do_9_2_reshutack;

sctp_state_fn_t sctp_sf_do_9_2_reshut;

sctp_state_fn_t sctp_sf_do_9_2_shutack;

/* Prototypes for timeout event state functions.  Not in use. */

sctp_state_fn_t sctp_do_4_2_reinit;

sctp_state_fn_t sctp_do_4_3_reecho;

sctp_state_fn_t sctp_do_9_2_reshut;

sctp_state_fn_t sctp_do_9_2_reshutack;

sctp_state_fn_t sctp_do_8_3_hb_err;

sctp_state_fn_t sctp_heartoff;

/* Prototypes for utility support functions.  */

__u8 sctp_get_chunk_type(struct sctp_chunk *chunk);

const sctp_sm_table_entry_t *sctp_sm_lookup_event(sctp_event_t,

                                            sctp_state_t,

                                            sctp_subtype_t);

int sctp_chunk_iif(const struct sctp_chunk *);

struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *,

                                             struct sctp_chunk *,

                                             int gfp);

__u32 sctp_generate_verification_tag(void);

void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag);

/* Prototypes for chunk-building functions.  */

struct sctp_chunk *sctp_make_init(const struct sctp_association *,

                             const struct sctp_bind_addr *,

                             int gfp, int vparam_len);

struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *,

                                 const struct sctp_chunk *,

                                 const int gfp,

                                 const int unkparam_len);

struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *,

                                    const struct sctp_chunk *);

struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *,

                                   const struct sctp_chunk *);

struct sctp_chunk *sctp_make_cwr(const struct sctp_association *,

                                 const __u32 lowest_tsn,

                                 const struct sctp_chunk *);

struct sctp_chunk *sctp_make_datafrag(struct sctp_association *,

                                 const struct sctp_sndrcvinfo *sinfo,

                                 int len, const __u8 *data,

                                 __u8 flags, __u16 ssn);

struct sctp_chunk * sctp_make_datafrag_empty(struct sctp_association *,

                                        const struct sctp_sndrcvinfo *sinfo,

                                        int len, const __u8 flags,

                                        __u16 ssn);

struct sctp_chunk *sctp_make_data(struct sctp_association *,

                             const struct sctp_sndrcvinfo *sinfo,

                             int len, const __u8 *data);

struct sctp_chunk *sctp_make_data_empty(struct sctp_association *,

                                   const struct sctp_sndrcvinfo *, int len);

struct sctp_chunk *sctp_make_ecne(const struct sctp_association *,

                                  const __u32);

struct sctp_chunk *sctp_make_sack(const struct sctp_association *);

struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,

                                      const struct sctp_chunk *chunk);

struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,

                                          const struct sctp_chunk *);

struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *,

                                          const struct sctp_chunk *);

void sctp_init_cause(struct sctp_chunk *, __u16 cause, const void *, size_t);

struct sctp_chunk *sctp_make_abort(const struct sctp_association *,

                              const struct sctp_chunk *,

                              const size_t hint);

struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *,

                                      const struct sctp_chunk *,

                                      __u32 tsn);

struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *,

                                   const struct sctp_chunk *,

                                   const struct msghdr *);

struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *,

                                  const struct sctp_transport *,

                                  const void *payload,

                                  const size_t paylen);

struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *,

                                      const struct sctp_chunk *,

                                      const void *payload,

                                      const size_t paylen);

struct sctp_chunk *sctp_make_op_error(const struct sctp_association *,

                                 const struct sctp_chunk *chunk,

                                 __u16 cause_code,

                                 const void *payload,

                                 size_t paylen);

struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,

                                    union sctp_addr *addr,

                                    int vparam_len);

struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *,

                                              union sctp_addr *,

                                              struct sockaddr *,

                                              int, __u16);

struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,

                                             union sctp_addr *addr);

struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,

                                        __u32 serial, int vparam_len);

struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,

                                       struct sctp_chunk *asconf);

int sctp_process_asconf_ack(struct sctp_association *asoc,

                            struct sctp_chunk *asconf_ack);

void sctp_chunk_assign_tsn(struct sctp_chunk *);

void sctp_chunk_assign_ssn(struct sctp_chunk *);

/* Prototypes for statetable processing. */

int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,

               sctp_state_t state,

               struct sctp_endpoint *,

               struct sctp_association *asoc,

               void *event_arg,

               int gfp);

int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,

                      sctp_state_t state,

                      struct sctp_endpoint *,

                      struct sctp_association *asoc,

                      void *event_arg,

                      sctp_disposition_t status,

                      sctp_cmd_seq_t *commands,

                      int gfp);

/* 2nd level prototypes */

int sctp_cmd_interpreter(sctp_event_t, sctp_subtype_t, sctp_state_t,

                         struct sctp_endpoint *, struct sctp_association *,

                         void *event_arg, sctp_disposition_t,

                         sctp_cmd_seq_t *retval, int gfp);

int sctp_gen_sack(struct sctp_association *, int force, sctp_cmd_seq_t *);

void sctp_generate_t3_rtx_event(unsigned long peer);

void sctp_generate_heartbeat_event(unsigned long peer);

sctp_sackhdr_t *sctp_sm_pull_sack(struct sctp_chunk *);

struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *,

                                       const struct sctp_association *,

                                       struct sctp_chunk *chunk,

                                       const void *payload,

                                       size_t paylen);

struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *,

                                      const struct sctp_chunk *);

void sctp_ootb_pkt_free(struct sctp_packet *);

struct sctp_cookie_param *

sctp_pack_cookie(const struct sctp_endpoint *, const struct sctp_association *,

                 const struct sctp_chunk *, int *cookie_len,

                 const __u8 *, int addrs_len);

struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *,

                                       const struct sctp_association *,

                                       struct sctp_chunk *, int gfp, int *err,

                                       struct sctp_chunk **err_chk_p);

int sctp_addip_addr_config(struct sctp_association *, sctp_param_t,

                           struct sockaddr_storage*, int);

void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,

                                const struct sctp_association *asoc,

                                const struct sctp_chunk *chunk,

                                sctp_cmd_seq_t *commands,

                                struct sctp_chunk *err_chunk);

/* 3rd level prototypes */

__u32 sctp_generate_tag(const struct sctp_endpoint *);

__u32 sctp_generate_tsn(const struct sctp_endpoint *);

/* Extern declarations for major data structures.  */

const sctp_sm_table_entry_t *sctp_chunk_event_lookup(sctp_cid_t, sctp_state_t);

extern const sctp_sm_table_entry_t

primitive_event_table[SCTP_NUM_PRIMITIVE_TYPES][SCTP_STATE_NUM_STATES];

extern const sctp_sm_table_entry_t

other_event_table[SCTP_NUM_OTHER_TYPES][SCTP_STATE_NUM_STATES];

extern const sctp_sm_table_entry_t

timeout_event_table[SCTP_NUM_TIMEOUT_TYPES][SCTP_STATE_NUM_STATES];

extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES];

/* These are some handy utility macros... */

/* Get the size of a DATA chunk payload. */

static inline __u16 sctp_data_size(struct sctp_chunk *chunk)

{

        __u16 size;

        size = ntohs(chunk->chunk_hdr->length);

        size -= sizeof(sctp_data_chunk_t);

        return size;

}

/* Compare two TSNs */

/* RFC 1982 - Serial Number Arithmetic

 *

 * 2. Comparison

 *  Then, s1 is said to be equal to s2 if and only if i1 is equal to i2,

 *  in all other cases, s1 is not equal to s2.

 *

 * s1 is said to be less than s2 if, and only if, s1 is not equal to s2,

 * and

 *

 *      (i1 < i2 and i2 - i1 < 2^(SERIAL_BITS - 1)) or

 *      (i1 > i2 and i1 - i2 > 2^(SERIAL_BITS - 1))

 *

 * s1 is said to be greater than s2 if, and only if, s1 is not equal to

 * s2, and

 *

 *      (i1 < i2 and i2 - i1 > 2^(SERIAL_BITS - 1)) or

 *      (i1 > i2 and i1 - i2 < 2^(SERIAL_BITS - 1))

 */

/*

 * RFC 2960

 *  1.6 Serial Number Arithmetic

 *

 * Comparisons and arithmetic on TSNs in this document SHOULD use Serial

 * Number Arithmetic as defined in [RFC1982] where SERIAL_BITS = 32.

 */

enum {

        TSN_SIGN_BIT = (1<<31)

};

static inline int TSN_lt(__u32 s, __u32 t)

{

        return (((s) - (t)) & TSN_SIGN_BIT);

}

static inline int TSN_lte(__u32 s, __u32 t)

{

        return (((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT));

}

/* Compare two SSNs */

/*

 * RFC 2960

 *  1.6 Serial Number Arithmetic

 *

 * Comparisons and arithmetic on Stream Sequence Numbers in this document

 * SHOULD use Serial Number Arithmetic as defined in [RFC1982] where

 * SERIAL_BITS = 16.

 */

enum {

        SSN_SIGN_BIT = (1<<15)

};

static inline int SSN_lt(__u16 s, __u16 t)

{

        return (((s) - (t)) & SSN_SIGN_BIT);

}

static inline int SSN_lte(__u16 s, __u16 t)

{

        return (((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT));

}

/*

 * ADDIP 3.1.1

 * The valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). Serial

 * Numbers wrap back to 0 after reaching 4294967295.

 */

enum {

        ADDIP_SERIAL_SIGN_BIT = (1<<31)

};

static inline int ADDIP_SERIAL_gte(__u16 s, __u16 t)

{

        return (((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT));

}

/* Run sctp_add_cmd() generating a BUG() if there is a failure.  */

static inline void sctp_add_cmd_sf(sctp_cmd_seq_t *seq, sctp_verb_t verb, sctp_arg_t obj)

{

        if (unlikely(!sctp_add_cmd(seq, verb, obj)))

                BUG();

}

/* Check VTAG of the packet matches the sender's own tag OR its peer's

 * tag and the T bit is set in the Chunk Flags.

 */

static inline int

sctp_vtag_verify_either(const struct sctp_chunk *chunk,

                        const struct sctp_association *asoc)

{

        /* RFC 2960 Section 8.5.1, sctpimpguide-06 Section 2.13.2

         *

         * B) The receiver of a ABORT shall accept the packet if the

         * Verification Tag field of the packet matches its own tag OR it

         * is set to its peer's tag and the T bit is set in the Chunk

         * Flags. Otherwise, the receiver MUST silently discard the packet

         * and take no further action.

         *

         * (C) The receiver of a SHUTDOWN COMPLETE shall accept the

         * packet if the Verification Tag field of the packet

         * matches its own tag OR it is set to its peer's tag and

         * the T bit is set in the Chunk Flags.  Otherwise, the

         * receiver MUST silently discard the packet and take no

         * further action....

         *

         */

        if ((ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag) ||

            (sctp_test_T_bit(chunk) && (ntohl(chunk->sctp_hdr->vtag)

            == asoc->c.peer_vtag))) {

                return 1;

        }

        return 0;

}

#endif /* __sctp_sm_h__ */