siproxd/src/plugin_fix_bogus_via.c

/*
    Copyright (C) 2008  Thomas Ries <tries@gmx.net>

    This file is part of Siproxd.

    Siproxd 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 2 of the License, or
    (at your option) any later version.

    Siproxd is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warrantry 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 Siproxd; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
*/

#include "config.h"

#include <string.h>

#include <netinet/in.h>
#include <arpa/inet.h>

#include <osipparser2/osip_parser.h>

#include "siproxd.h"
#include "plugins.h"
#include "log.h"

static char const ident[]="$Id$";

/* Plug-in identification */
static char name[]="plugin_fix_bogus_via";
static char desc[]="Fixes broken VIA headers on incoming calls";

/* global configuration storage - required for config file location */
extern struct siproxd_config configuration;

/* plugin configuration storage */
static struct plugin_config {
   char *networks;
} plugin_cfg;

/* Instructions for config parser */
static cfgopts_t plugin_cfg_opts[] = {
   { "plugin_fix_bogus_via_networks",      TYP_STRING, &plugin_cfg.networks },
   {0, 0, 0}
};

/* Prototypes */
static int sip_patch_topvia(sip_ticket_t *ticket);


/* 
 * Initialization.
 * Called once suring siproxd startup.
 */
int  plugin_init(plugin_def_t *plugin_def) {
   /* API version number of siproxd that this plugin is built against.
    * This constant will change whenever changes to the API are made
    * that require adaptions in the plugin. */
   plugin_def->api_version=SIPROXD_API_VERSION;

   /* Name and descriptive text of the plugin */
   plugin_def->name=name;
   plugin_def->desc=desc;

   /* Execution mask - during what stages of SIP processing shall
    * the plugin be called. */
   plugin_def->exe_mask=PLUGIN_PRE_PROXY;

   /* read the config file */
   if (read_config(configuration.configfile,
                   configuration.config_search,
                   plugin_cfg_opts, name) == STS_FAILURE) {
      ERROR("Plugin '%s': could not load config file", name);
      return STS_FAILURE;
   }

   INFO("plugin_fix_bogus_via is initialized");
   return STS_SUCCESS;
}

/*
 * Processing.
 * 
 */
int  plugin_process(int stage, sip_ticket_t *ticket){
   /* stage contains the PLUGIN_* value - the stage of SIP processing. */
   int type;
   osip_via_t *via;
   struct sockaddr_in from;

   type = ticket->direction;

   /* Incoming SIP message? */
DEBUGC(DBCLASS_PLUGIN, "plugin_fix_bogus_via: type=%i", type);
   if (type == REQTYP_INCOMING) {

      if((via = osip_list_get(&(ticket->sipmsg->vias), 0)) == NULL) {
         WARN("no Via header found in incoming SIP message");
         return STS_SUCCESS;
      }

      get_ip_by_host(via->host, &(from.sin_addr));

      /* check for Via IP in configured range */
      if ((plugin_cfg.networks != NULL) &&
          (strcmp(plugin_cfg.networks, "") !=0) &&
          (process_aclist(plugin_cfg.networks, from) == STS_SUCCESS)) {
         /* is in list, patch Via header with received from IP */
         DEBUGC(DBCLASS_PLUGIN, "plugin_fix_bogus_via: replacing a bogus via");
         if (sip_patch_topvia(ticket) == STS_FAILURE) {
            ERROR("patching inbound Via failed!");
         }
      }
   }
   return STS_SUCCESS;
}

/*
 * De-Initialization.
 * Called during shutdown of siproxd. Gives the plugin the chance
 * to clean up its mess (e.g. dynamic memory allocation, database
 * connections, whatever the plugin messes around with)
 */
int  plugin_end(plugin_def_t *plugin_def){
   INFO("plugin_fix_bogus_via ends here");
   return STS_SUCCESS;
}

/*--------------------------------------------------------------------*/
static int sip_patch_topvia(sip_ticket_t *ticket) {
   osip_via_t *via;

   if((via = osip_list_get(&(ticket->sipmsg->vias), 0)) != NULL) {
      /* clone Via header */

      /* set new IP (from IP) */
      osip_free(via->host);
      via->host=osip_malloc(IPSTRING_SIZE);
      snprintf(via->host, IPSTRING_SIZE, "%s",
               utils_inet_ntoa(ticket->from.sin_addr));
      via->host[IPSTRING_SIZE-1] ='\0';

      /* set new port number */
      osip_free(via->port);
      via->port=osip_malloc(6); /* 5 digits + \0 */
      snprintf(via->port, 5, "%u", ntohs(ticket->from.sin_port));
      via->port[5-1] ='\0';

      DEBUGC(DBCLASS_PLUGIN, "plugin_fix_bogus_via:  -> %s:%s",
             via->host, via->port);

   }

   return STS_SUCCESS;
}