siputils/utils.c

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/*
 * $Id: utils.c 5318 2008-12-08 16:38:47Z henningw $
 *
 * mangler module
 *
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio 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
 *
 * Kamailio 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, write to the Free Software 
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * History:
 * --------
 *  2003-04-07 first version.  
 */

#include "utils.h"

#include "../../parser/msg_parser.h"   /* struct sip_msg */
#include "../../mem/mem.h"
#include "../../data_lump.h"

#include <stdio.h>


int
patch (struct sip_msg *msg, char *oldstr, unsigned int oldlen, char *newstr,
       unsigned int newlen)
{
   int off;
   struct lump *anchor;

   if (oldstr == NULL)
      return -1;

   if (newstr == NULL)
      return -2;
   off = oldstr - msg->buf;
   if (off < 0)
      return -3;
   if ((anchor = del_lump (msg, off, oldlen, 0)) == 0)
   {
      LM_ERR("lumping with del_lump\n");
      return -4;
   }
   if ((insert_new_lump_after (anchor, newstr, newlen, 0)) == 0)
   {
      LM_ERR("lumping with insert_new_lump_after\n");
      return -5;
   }

   return 0;
}


/* TESTED */
int
patch_content_length (struct sip_msg *msg, unsigned int newValue)
{

   struct hdr_field *contentLength;
   char *s, pos[11];
   int len;

   contentLength = msg->content_length;
   if (contentLength == NULL) /* maybe not yet parsed */
   {
      if (parse_headers (msg, HDR_CONTENTLENGTH_F, 0) == -1)
      {
         LM_ERR("parse headers on Content-Length failed\n");
         return -1;
      }
      contentLength = msg->content_length;
      if (contentLength == NULL)
      {
         LM_ERR("failed to parse headers on Content-Length "
               "succeeded but msg->content_length is still NULL\n");
         return -2;
      }
   }
   /* perhaps dangerous because buffer is static ? */
   //pos = int2str(newValue,&len);
   len = snprintf ((char *) pos, 10, "%u", newValue);
   s = pkg_malloc (len);
   if (s == NULL)
   {
      LM_ERR("unable to allocate %d bytes in pkg mem\n", len);
      return -3;
   }
   memcpy (s, pos, len);
   /* perhaps we made it and no one called int2str,might use sprintf */
   if (patch
       (msg, contentLength->body.s, contentLength->body.len, s, len) < 0)
   {
      pkg_free (s);
      LM_ERR("lumping failed\n");
      return -4;
   }

   LM_DBG ("succeeded in altering Content-Length to new value %u\n",newValue);

   return 0;

}