sipproxyserver.c

这是HPOC SIP栈的SIPUA

    sip_msg_uri_t               * branch_next_hop,
    sip_msg_uri_t               * branch_request_uri,
    sip_uint32_t                  status_code,
    char                        * reason_phrase,
    sip_msg_header_t            * from,
    sip_msg_header_t            * to,
    sip_msg_header_t            * call_id,
    sip_msg_header_t            * cseq,
    sip_msg_header_vector_t     * response,
    sip_msg_body_t              * body,
    sip_user_info_t             * user_info,
    sip_uint8_t                   transport_id
   )
{
  sip_status_t    sip_status;
  int             index;
  sip_msg_error_t VS_error;
  /* We should forward the response */
  sip_status = sip_trans_forward_response(instance,
                                          trans,
                                          status_code,
                                          reason_phrase,
                                          response,
                                          body,
                                          NULL);/*此例程与sip trans forward request相似，功能为前转一个响应*/
  if (sip_status != SIP_NORMAL)
    {
      printf("Error %d in forwarding a response\n", sip_status);
    } 
  else 
    {
      printf("%d %s response forwarded.\n",
             status_code, reason_phrase);
    }

  if (status_code >= 200)
  {
    sip_exit = SIP_TRUE;
  }
  return SIP_NORMAL;
}

/*
 * FACILITY:
 *
 *      sip_trans_on_event
 *
 * ABSTRACT:
 *
 *      The SIP transaction event reception callback
 *
 * FORMAL PARAMETERS:
 *
 *      instance         : The SIP transaction instance
 *      trans            : The transaction ID
 *      event            : The transaction event
 *      user_info        : the user info
 *
 * RETURN VALUE:
 *
 *      SIP_NORMAL : successful completion
 *
 */

sip_status_t sip_trans_on_event
  (
    sip_trans_inst_t               instance,
    sip_trans_t                    trans,
    sip_trans_event_t            * event,
    sip_user_info_t              * user_info
   )/*这个函数仅仅只解析了event的type*/
{
  sip_status_t    sip_status;
  int             index;
  sip_msg_error_t VS_error;

  switch(event->type)
  {
    case  SIP_TRANS_EVENT_LOCAL_SRV_ERROR:
      printf("Local server error\n");
      break;
    case SIP_TRANS_EVENT_TRP_ERROR:
      printf("Transport error\n");
      break;
    case SIP_TRANS_EVENT_PARSER_ERROR:
      printf("Parser error\n");
      break;
    case SIP_TRANS_EVENT_TRANSACTION_DELETED:
      printf("Transaction deleted\n");
      break;
    case SIP_TRANS_EVENT_TIME_OUT:
      printf("Transaction deleted\n");
      break;
    default:
      printf("Event type:%d received\n",event->type);
    break;
  }
  return SIP_NORMAL;
}


/*
 * FACILITY:
 *
 *      usage
 *
 * ABSTRACT:
 *
 *      The help string displayed in case of error when
 *      parsing the comand line.
 *
 * FORMAL PARAMETERS:
 *
 *      The name of the command (argv[0]).
 *
 * RETURN VALUE:
 *
 *      None
 *
 */

void usage(char * command_name, char *forward_uri) 
{
  printf("\n%s [-p port] [-h] [-f request_URI]"
         "\n"
         "\n  Starts a SIP proxy server on the specified port, which forwards"
         "\n  any incoming requests to the URI given in the -f option."
         "\n"
         "\n  -p port       : The -p option specifies the UDP port number for"
         "\n                  the proxy server. The default port is 6060."
         "\n"
         "\n  -f request_URI: The -f option specifies the URI use to forward"
         "\n                  the received SIP requests. The default value"
         "\n                  is '%s'."
         "\n"
         "\n  -h            : Displays this help screen."
         "\n"
         "\n",
         command_name,
         forward_uri);
}

/*
 * FACILITY:
 *
 *      main
 *
 * ABSTRACT:
 *
 *      The main entry of the process
 *
 * FORMAL PARAMETERS:
 *
 *      argc, argv command line parameters
 *
 * RETURN VALUE:
 *
 *      None
 *
 */

int main(int argc, char *argv[])
{
  sip_status_t       sip_status = SIP_NORMAL;
  sip_trans_inst_t   sip_trans_inst;
  sip_trp_info_t     sip_trp_info[1];
  sip_uint32_t       sip_nb_trp = 1;
  struct hostent   * sip_local_host = NULL;
  char             * sip_local_ip = NULL;
  char               sip_pid[16] = { 0 };
  char               sip_appli_name[80] = { 0 };

  sip_trans_callback_vector_t sip_trans_callback;

  int argi;
  int port = 6060;

  if  ((gethostname(sip_appli_name,64) != 0)
   || (!(sip_local_host = gethostbyname(sip_appli_name))))
  {
    printf("cannot get local host informations\n");
    exit(1);
  }  
  sip_local_ip = (char *) 
  inet_ntoa (*(unsigned long *)(sip_local_host->h_addr_list[0]));

  forward_to_uri = (char *) malloc (80 * sizeof(char));
  memset(forward_to_uri,0,(80 * sizeof(char)));
  strcat(forward_to_uri,"sip:user@");
  strcat(forward_to_uri,sip_local_ip);
  strcat(forward_to_uri,":5060");

  for(argi = 1; argi < argc; argi++) {

    if(!strcmp(argv[argi], "-p")) {
      if((++argi) < argc) {
        port = atol(argv[argi]);
      } else {
        usage(argv[0],forward_to_uri);
        free(forward_to_uri);
        exit(1);
      }
    }
    
    if(!strcmp(argv[argi], "-f")) {
      if((++argi) < argc) {
        forward_to_uri = argv[argi];
      } else {
        usage(argv[0],forward_to_uri);
        free(forward_to_uri);
        exit(1);
      }
    }
    
    if(!strcmp(argv[argi], "-h")) {
        usage(argv[0],forward_to_uri);
        free(forward_to_uri);
        exit(0);
    }
  }

  strcat(sip_appli_name,"_sipproxyserver_");
  sprintf(sip_pid,"%d",getpid());
  strcat(sip_appli_name,sip_pid);
  
  sip_status = sip_init_lib(sip_appli_name,
                            0,
                            NULL,
                            SIP_API_VERSION);

  printf("SIP Proxy server (%s) IP:%s started on UDP port %d\n",
         sip_appli_name,
         sip_local_ip,
         port);

  /* Fill the SIP transaction callback */
  memset(&sip_trans_callback, 0, sizeof(sip_trans_callback_vector_t));
  sip_trans_callback.sip_trans_on_invite    = sip_trans_on_invite;
  sip_trans_callback.sip_trans_on_bye       = sip_trans_on_bye;
  sip_trans_callback.sip_trans_on_ack       = sip_trans_on_ack;
  sip_trans_callback.sip_trans_on_response  = sip_trans_on_response;
  sip_trans_callback.sip_trans_on_event     = sip_trans_on_event;  

  /* Fill the transport info array */
  sip_trp_info[0].trp_name = (char *) strdup(sip_appli_name);
  sip_trp_info[0].address  = sip_local_ip;
  sip_trp_info[0].port     = port;
  sip_trp_info[0].trp_type = SIP_TRP_UDP;

  /* Create the SIP transaction instance *//*用给定的transport信息创建新的SIPtransaction实例*/
  sip_status = sip_trans_create_instance(&sip_trans_inst,
                                         sip_appli_name,
                                         &sip_trans_callback,
                                         sip_trp_info,
                                         sip_nb_trp,
                                         NULL);
  if (sip_status != SIP_NORMAL)
  {
    printf("Error in sip_trans_create_instance function: %d\n", sip_status);
    free(forward_to_uri);
    exit(1);
  }

  /* Enable the SIP transaction instance *//*它开始处理底层的transport实例传递的indication，使用户能调用此实例的transaction例程*/
  sip_status = sip_trans_enable_instance(sip_trans_inst);
  if (sip_status != SIP_NORMAL)
  {
    sip_trans_delete_instance(sip_trans_inst);
    printf("Error in sip_trans_enable_instance function: %d\n", sip_status);
    free(forward_to_uri);
    exit(1);
  }

  /* Waiting for incoming messages */
  while (1)
  {
    sip_status = sip_trans_deliver_indic(sip_trans_inst,
                                         SIP_FALSE,         /* non blocking */
                                         SIP_DELIVER_ALL_MSG,
                                         NULL);/*此例程传递与SIPtransaction实例相关的indication。通过调用相关的transaction回调例程来传递indication.*/
    if (sip_status != SIP_NORMAL)
    {
      sip_trans_delete_instance(sip_trans_inst);
      printf("Error %d in delivering indication\n", sip_status);
      free(forward_to_uri);
      exit(1);
    }

    if (sip_exit)
    {
      sleep(3);
      sip_trans_delete_instance(sip_trans_inst);
      printf("Exiting\n");
      free(forward_to_uri);
      exit(1);
    }
  }
}