Function sctp_handle_nat_colliding_state

freebsd/netinet/sctp_input.c:703–759

}

static int
sctp_handle_nat_colliding_state(struct sctp_tcb *stcb)
{
	/*
	 * Return 0 means we want you to proceed with the abort non-zero
	 * means no abort processing.
	 */
	uint32_t new_vtag;
	struct sctpasochead *head;

	if ((SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_WAIT) ||
	    (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_ECHOED)) {
		new_vtag = sctp_select_a_tag(stcb->sctp_ep, stcb->sctp_ep->sctp_lport, stcb->rport, 1);
		atomic_add_int(&stcb->asoc.refcnt, 1);
		SCTP_TCB_UNLOCK(stcb);
		SCTP_INP_INFO_WLOCK();
		SCTP_TCB_LOCK(stcb);
		atomic_subtract_int(&stcb->asoc.refcnt, 1);
	} else {
		return (0);
	}
	if (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_WAIT) {
		/* generate a new vtag and send init */
		LIST_REMOVE(stcb, sctp_asocs);
		stcb->asoc.my_vtag = new_vtag;
		head = &SCTP_BASE_INFO(sctp_asochash)[SCTP_PCBHASH_ASOC(stcb->asoc.my_vtag, SCTP_BASE_INFO(hashasocmark))];
		/*
		 * put it in the bucket in the vtag hash of assoc's for the
		 * system
		 */
		LIST_INSERT_HEAD(head, stcb, sctp_asocs);
		SCTP_INP_INFO_WUNLOCK();
		sctp_send_initiate(stcb->sctp_ep, stcb, SCTP_SO_NOT_LOCKED);
		return (1);
	} else {
		/*
		 * treat like a case where the cookie expired i.e.: - dump
		 * current cookie. - generate a new vtag. - resend init.
		 */
		/* generate a new vtag and send init */
		LIST_REMOVE(stcb, sctp_asocs);
		SCTP_SET_STATE(stcb, SCTP_STATE_COOKIE_WAIT);
		sctp_stop_all_cookie_timers(stcb);
		sctp_toss_old_cookies(stcb, &stcb->asoc);
		stcb->asoc.my_vtag = new_vtag;
		head = &SCTP_BASE_INFO(sctp_asochash)[SCTP_PCBHASH_ASOC(stcb->asoc.my_vtag, SCTP_BASE_INFO(hashasocmark))];
		/*
		 * put it in the bucket in the vtag hash of assoc's for the
		 * system
		 */
		LIST_INSERT_HEAD(head, stcb, sctp_asocs);
		SCTP_INP_INFO_WUNLOCK();
		sctp_send_initiate(stcb->sctp_ep, stcb, SCTP_SO_NOT_LOCKED);
		return (1);
	}
	return (0);
}