/*
 * In this module we implement an essential step in the process
 * of handling incoming SIP response messages: extracting Call-ID
 * and CSeq headers and preparsing the latter, providing key info
 * for matching these incoming responses with call state and
 * with outstanding UAC requests.
 */

#include <ctype.h>
#include <string.h>
#include <strings.h>
#include <stdio.h>
#include <stdlib.h>
#include "parse.h"
#include "resp_ident.h"

extern char *get_single_header();

sip_resp_extract_ident(msg, id)
	struct sip_pkt_rx *msg;
	struct sip_resp_ident *id;
{
	char *hval, *cp;
	int dup_flag = 0;

	hval = get_single_header(msg, "Call-ID", "i", &dup_flag);
	if (!hval || dup_flag) {
		id->error_field = "Call-ID";
		return(-1);
	}
	id->call_id = hval;
	hval = get_single_header(msg, "CSeq", (char *) 0, &dup_flag);
	if (!hval || dup_flag) {
bad_cseq:	id->error_field = "CSeq";
		return(-1);
	}
	if (!isdigit(*hval))
		goto bad_cseq;
	id->cseq_num = strtoul(hval, &cp, 10);
	if (!isspace(*cp))
		goto bad_cseq;
	while (isspace(*cp))
		cp++;
	if (!isupper(*cp))
		goto bad_cseq;
	id->cseq_method = cp;
	while (isalnum(*cp))
		cp++;
	if (*cp)
		goto bad_cseq;
	return(0);
}