sm.h

linux-2.6.15.6

				   const struct msghdr *);
struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *,
				   const struct sctp_chunk *,
				   const __u8 *,
				   const size_t );
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_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_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);

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,
	       gfp_t gfp);

/* 2nd level prototypes */
void sctp_generate_t3_rtx_event(unsigned long peer);
void sctp_generate_heartbeat_event(unsigned long peer);

void sctp_ootb_pkt_free(struct sctp_packet *);

struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *,
				       const struct sctp_association *,
				       struct sctp_chunk *,
				       gfp_t gfp, int *err,
				       struct sctp_chunk **err_chk_p);
int sctp_addip_addr_config(struct sctp_association *, sctp_param_t,
			   struct sockaddr_storage*, int);

/* 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.  */
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 -= 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. */
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 1;

	return 0;
}

/* 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) &&
	     (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) {
                return 1;
	}

	return 0;
}

#endif /* __sctp_sm_h__ */