modules_k/siputils/utils.c

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/*
 * $Id$
 *
 * mangler module
 *
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of SIP-router, a free SIP server.
 *
 * SIP-router 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
 *
 * SIP-router 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;

}