/*
 * Copyright (C), 2008 by Bret McDanel <trixter AT 0xdecafbad.com>
 * Copyright (C), 2008 by Pierrick Grasland <address@hidden>
 * All Rights Reserved.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or 
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/ >.
 */

#include <config.h>

#ifdef HAVE_STDIO_H
#include <stdio.h>
#endif

#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif

#ifdef HAVE_STRING_H
#include <string.h>
#endif

#ifdef HAVE_TIME_H
#include <time.h>
#endif

#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif

#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif 

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

#include "protocol.h"


/**
 *
 *  A SIP test. 
 *
 *  This test has been created in order to construct valid SIP message, 
 *  even with a low poll cycle. (In case of low poll cycle, chance are 
 *  high for a  misinterpretation of the generic test by the SIP AS. It 
 *  will considered it for  a retransmission, not for a new message)
 *
 *  The test sends an OPTIONS request and check the server's status code.
 *
 *  The status code must be between 200 and 300
 *  Return TRUE if the status code is OK, otherwise FALSE
 * 
 *  In this current version, redirection is not supported. 
 *
 *  @author Pierrick Grasland <address@hidden>
 *  @author Bret McDanel, <trixter AT 0xdecafbad.com>
 *  @version \$Id: sip.c,v 1.4 2008/01/18 13:48:39 hauk Exp $
 *
 *  @file
 */
 
 
 /* -------------------------------------------------------------- Public*/ 
 
int check_sip(Socket_T s) {
  int status;
  char buf[STRLEN];
  int port;
  char *transport;
  Port_T P;
  const char *request;
  const char *myip;
  char *rport= "";
  char *proto;
  int seed;
  
  ASSERT(s);

  P= socket_get_Port(s);
  ASSERT(P);
  request= P->request?P->request:"address@hidden";

  port = socket_get_local_port(s);
  proto = socket_is_secure(s) ? "sips" : "sip";  

  switch(socket_get_type(s)) {
  case SOCK_DGRAM:
    transport="UDP";
    rport=";rport";
	seed=1;
    break;
  case SOCK_STREAM:
    transport="TCP";
	seed=2;
    break;
  default:
    LogError("Unsupported socket type, only TCP and UDP are supported\n");
    return TRUE;
  }

  myip= socket_get_local_host(s);

  /* initialization of random param */
  srand(time(NULL)+getpid()+seed);

  if(socket_print(s,
		  "OPTIONS %s:%s SIP/2.0\r\n"
		  "Via: SIP/2.0/%s %s:%d;branch=z9hG4bKh%u%s\r\n"
		  "Max-Forwards: %d\r\n"
		  "To: <%s:%s>\r\n"
		  "From: monit <%s:address@hidden>;tag=%d\r\n"
		  "Call-ID: %u\r\n"
		  "CSeq: 63104 OPTIONS\r\n"
		  "Contact: <%s:%s:%d>\r\n"
		  "Accept: application/sdp\r\n"
		  "Content-Length: 0\r\n"
      "User-Agent: %s/%s\r\n\r\n",
      proto,            // protocol
		  request,          // to
		  transport,        // via transport udp|tcp
		  myip,             // who its from
		  port,             // our port
		  rand(),           // branch
		  rport,            // rport option
		  P->maxforward,    // maximum forwards
		  proto,            // protocol
		  request,          // to
		  proto,            // protocol
		  myip,             // from host
		  rand(),           // tag
		  rand(),           // call id
		  proto,            // protocol
		  myip,             // contact host
		  port,             // contact port
		  prog, VERSION     // user agent
		  ) < 0) {
    LogError("SIP: error sending data -- %s\n", STRERROR);
    return FALSE;
  }

  if(! socket_readln(s, buf, sizeof(buf))) {
    LogError("SIP: error receiving data -- %s\n", STRERROR);
    return FALSE;
  }

  Util_chomp(buf);
  
  DEBUG("Response from SIP server: %s\n", buf);

  if(! sscanf(buf, "%*s %d", &status)) { 
      LogError("SIP error: cannot parse SIP status in response: %s\n", buf);
      return FALSE;
    }
   
  if(status >= 400) {
     LogError("SIP error: Server returned status %d\n", status);
     return FALSE;
  }
  
  if(status >= 300 && status < 400) {
     LogError("SIP info: Server redirection. Returned status %d\n", status); 
     return FALSE;
  }
  
  if(status > 100 && status < 200) {
     LogError("SIP error: Provisional response . Returned status %d\n", status);
     return FALSE;
  }
  
  return TRUE;

}