/*
 * Here we implement our handling of SIP ACK, the last step
 * in the 3-way INVITE handshake.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <syslog.h>
#include "../libsip/parse.h"
#include "../libsip/uas_basic.h"
#include "call.h"

extern struct call *find_call_by_sip_id();

void
handle_sip_ack(req, ess, sin)
	struct sip_pkt_rx *req;
	struct uas_parse_hdrs *ess;
	struct sockaddr_in *sin;
{
	struct call *call;

	call = find_call_by_sip_id(ess->call_id);
	if (!call)
		return;		/* ignore spurious ACK */
	/* weed out wrong CSeq */
	if (ess->cseq_num != call->invite_cseq)
		return;
	switch (call->sip_state) {
	case SIP_STATE_INVITE_200:
		switch (call->overall_state) {
		case OVERALL_STATE_ANSWERED:
			call->sip_state = SIP_STATE_CONNECTED;
			break;
		case OVERALL_STATE_TEARDOWN:
			initiate_bye(call);
			break;
		default:
			syslog(LOG_CRIT,
			"FATAL: invalid overall state 0x%x on SIP ACK",
				call->overall_state);
			exit(1);
		}
		break;
	case SIP_STATE_INVITE_ERR:
		call->sip_state = SIP_STATE_ENDED;
		break;
	}
}