/* SPDX-License-Identifier: GPL-2.0-or-later */
/* SCTP kernel implementation
* (C) Copyright IBM Corp. 2001, 2004
* 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 implementation
*
* These are definitions needed by the state machine.
*
* Please send any bug reports or fixes you make to the
* email addresses:
* lksctp developers <[email protected]>
*
* Written or modified by:
* La Monte H.P. Yarroll <[email protected]>
* Karl Knutson <[email protected]>
* Xingang Guo <[email protected]>
* Jon Grimm <[email protected]>
* Dajiang Zhang <[email protected]>
* Sridhar Samudrala <[email protected]>
* Daisy Chang <[email protected]>
* Ardelle Fan <[email protected]>
* Kevin Gao <[email protected]>
*/
#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:
*/
enum sctp_disposition {
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. */
};
typedef enum sctp_disposition (sctp_state_fn_t) (
struct net *net,
const struct sctp_endpoint *ep,
const struct sctp_association *asoc,
const union sctp_subtype type,
void *arg,
struct sctp_cmd_seq *commands);
typedef void (sctp_timer_event_t) (struct timer_list *);
struct sctp_sm_table_entry {
sctp_state_fn_t *fn;
const char *name;
};
/* 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_operr_notify;
sctp_state_fn_t sctp_sf_t1_init_timer_expire;
sctp_state_fn_t sctp_sf_t1_cookie_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_9_2_shut_ctsn;
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_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_3_initack;
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_asconf;
sctp_state_fn_t sctp_sf_do_asconf_ack;
sctp_state_fn_t sctp_sf_do_reconf;
sctp_state_fn_t sctp_sf_do_9_2_reshutack;
sctp_state_fn_t sctp_sf_eat_fwd_tsn;
sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast;
sctp_state_fn_t sctp_sf_eat_auth;
/* 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;
sctp_state_fn_t sctp_sf_do_prm_reconf;
/* Prototypes for other event state functions. */
sctp_state_fn_t sctp_sf_do_no_pending_tsn;
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;
sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort;
/* Prototypes for timeout event state functions. */
sctp_state_fn_t sctp_sf_do_6_3_3_rtx;
sctp_state_fn_t sctp_sf_send_reconf;
sctp_state_fn_t sctp_sf_send_probe;
sctp_state_fn_t sctp_sf_do_6_2_sack;
sctp_state_fn_t sctp_sf_autoclose_timer_expire;
/* Prototypes for utility support functions. */
const struct sctp_sm_table_entry *sctp_sm_lookup_event(
struct net *net,
enum sctp_event_type event_type,
enum sctp_state state,
union sctp_subtype event_subtype);
int sctp_chunk_iif(const struct sctp_chunk *);
struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *,
struct sctp_chunk *,
gfp_t gfp);
/* Prototypes for chunk-building functions. */
struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
const struct sctp_bind_addr *bp,
gfp_t gfp, int vparam_len);
struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
const gfp_t gfp, const int unkparam_len);
struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
const struct sctp_chunk *chunk);
struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
const struct sctp_chunk *chunk);
struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
const __u32 lowest_tsn,
const struct sctp_chunk *chunk);
struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
__u8 flags, int paylen, gfp_t gfp);
struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
__u32 new_cum_tsn, size_t nstreams,
struct sctp_ifwdtsn_skip *skiplist);
struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
const struct sctp_sndrcvinfo *sinfo,
int len, __u8 flags, gfp_t gfp);
struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
const __u32 lowest_tsn);
struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc);
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 *chunk);
struct sctp_chunk *sctp_make_shutdown_complete(
const struct sctp_association *asoc,
const struct sctp_chunk *chunk);
int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause, size_t paylen);
struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
const size_t hint);
struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
__u32 tsn);
struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
struct msghdr *msg, size_t msg_len);
struct sctp_chunk *sctp_make_abort_violation(
const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
const __u8 *payload,
const size_t paylen);
struct sctp_chunk *sctp_make_violation_paramlen(
const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
struct sctp_paramhdr *param);
struct sctp_chunk *sctp_make_violation_max_retrans(
const struct sctp_association *asoc,
const struct sctp_chunk *chunk);
struct sctp_chunk *sctp_make_new_encap_port(
const struct sctp_association *asoc,
const struct sctp_chunk *chunk);
struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
const struct sctp_transport *transport,
__u32 probe_size);
struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
const void *payload,
const size_t paylen);
struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len);
struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
__be16 cause_code, const void *payload,
size_t paylen, size_t reserve_tail);
struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
union sctp_addr *laddr,
struct sockaddr *addrs,
int addrcnt, __be16 flags);
struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
union sctp_addr *addr);
bool sctp_verify_asconf(const struct sctp_association *asoc,
struct sctp_chunk *chunk, bool addr_param_needed,
struct sctp_paramhdr **errp);
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);
struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
__u32 new_cum_tsn, size_t nstreams,
struct sctp_fwdtsn_skip *skiplist);
struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
__u16 key_id);
struct sctp_chunk *sctp_make_strreset_req(const struct sctp_association *asoc,
__u16 stream_num, __be16 *stream_list,
bool out, bool in);
struct sctp_chunk *sctp_make_strreset_tsnreq(
const struct sctp_association *asoc);
struct sctp_chunk *sctp_make_strreset_addstrm(
const struct sctp_association *asoc,
__u16 out, __u16 in);
struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
__u32 result, __u32 sn);
struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
__u32 result, __u32 sn,
__u32 sender_tsn,
__u32 receiver_tsn);
bool sctp_verify_reconf(const struct sctp_association *asoc,
struct sctp_chunk *chunk,
struct sctp_paramhdr **errp);
void sctp_chunk_assign_tsn(struct sctp_chunk *chunk);
void sctp_chunk_assign_ssn(struct sctp_chunk *chunk);
/* Prototypes for stream-processing functions. */
struct sctp_chunk *sctp_process_strreset_outreq(
struct sctp_association *asoc,
union sctp_params param,
struct sctp_ulpevent **evp);
struct sctp_chunk *sctp_process_strreset_inreq(
struct sctp_association *asoc,
union sctp_params param,
struct sctp_ulpevent **evp);
struct sctp_chunk *sctp_process_strreset_tsnreq(
struct sctp_association *asoc,
union sctp_params param,
struct sctp_ulpevent **evp);
struct sctp_chunk *sctp_process_strreset_addstrm_out(
struct sctp_association *asoc,
union sctp_params param,
struct sctp_ulpevent **evp);
struct sctp_chunk *sctp_process_strreset_addstrm_in(
struct sctp_association *asoc,
union sctp_params param,
struct sctp_ulpevent **evp);
struct sctp_chunk *sctp_process_strreset_resp(
struct sctp_association *asoc,
union sctp_params param,
struct sctp_ulpevent **evp);
/* Prototypes for statetable processing. */
int sctp_do_sm(struct net *net, enum sctp_event_type event_type,
union sctp_subtype subtype, enum sctp_state state,
struct sctp_endpoint *ep, struct sctp_association *asoc,
void *event_arg, gfp_t gfp);
/* 2nd level prototypes */
void sctp_generate_t3_rtx_event(struct timer_list *t);
void sctp_generate_heartbeat_event(struct timer_list *t);
void sctp_generate_reconf_event(struct timer_list *t);
void sctp_generate_probe_event(struct timer_list *t);
void sctp_generate_proto_unreach_event(struct timer_list *t);
void sctp_ootb_pkt_free(struct sctp_packet *packet);
struct sctp_association *sctp_unpack_cookie(
const struct sctp_endpoint *ep,
const struct sctp_association *asoc,
struct sctp_chunk *chunk,
gfp_t gfp, int *err,
struct sctp_chunk **err_chk_p);
/* 3rd level prototypes */
__u32 sctp_generate_tag(const struct sctp_endpoint *ep);
__u32 sctp_generate_tsn(const struct sctp_endpoint *ep);
/* Extern declarations for major data structures. */
extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES];
/* 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 -= sctp_datachk_len(&chunk->asoc->stream);
return size;
}
/* Compare two TSNs */
#define TSN_lt(a,b) \
(typecheck(__u32, a) && \
typecheck(__u32, b) && \
((__s32)((a) - (b)) < 0))
#define TSN_lte(a,b) \
(typecheck(__u32, a) && \
typecheck(__u32, b) && \
((__s32)((a) - (b)) <= 0))
/* Compare two MIDs */
#define MID_lt(a, b) \
(typecheck(__u32, a) && \
typecheck(__u32, b) && \
((__s32)((a) - (b)) < 0))
/* Compare two SSNs */
#define SSN_lt(a,b) \
(typecheck(__u16, a) && \
typecheck(__u16, b) && \
((__s16)((a) - (b)) < 0))
/* ADDIP 3.1.1 */
#define ADDIP_SERIAL_gte(a,b) \
(typecheck(__u32, a) && \
typecheck(__u32, b) && \
((__s32)((b) - (a)) <= 0))
/* Check VTAG of the packet matches the sender's own tag. */
static inline int
sctp_vtag_verify(const struct sctp_chunk *chunk,
const struct sctp_association *asoc)
{
/* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint
* MUST ensure that the value in the Verification Tag field of
* the received SCTP packet matches its own Tag. If the received
* Verification Tag value does not match the receiver's own
* tag value, the receiver shall silently discard the packet...
*/
if (ntohl(chunk->sctp_hdr->vtag) != asoc->c.my_vtag)
return 0;
chunk->transport->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port;
return 1;
}
/* Check VTAG of the packet matches the sender's own tag and the T bit is
* not set, 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 Section 2.41
*
* B) The receiver of a ABORT MUST accept the packet
* if the Verification Tag field of the packet matches its own tag
* and the T bit is not set
* 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
* and the T bit is not set
* 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. An endpoint MUST ignore the
* SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
*/
if ((!sctp_test_T_bit(chunk) &&
(ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) ||
(sctp_test_T_bit(chunk) && asoc->c.peer_vtag &&
(ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) {
return 1;
}
return 0;
}
#endif /* __sctp_sm_h__ */
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