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kamailio/modules/maxfwd/mf_funcs.c

153 lines
3.9 KiB

/*
* $Id$
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* History:
* ----------
* 2003-02-28 scratchpad compatibility abandoned (jiri)
* 2002-01-28 scratchpad removed (jiri)
* 2004-08-15 max value of max-fwd header is configurable (bogdan)
* 2005-11-03 MF value saved in msg->maxforwards->parsed (bogdan)
*/
#include <stdlib.h>
#include <string.h>
#include "mf_funcs.h"
#include "../../mem/mem.h"
#include "../../ut.h"
#include "../../data_lump.h"
#define MF_HDR "Max-Forwards: "
#define MF_HDR_LEN (sizeof(MF_HDR) - 1)
/* do a tricky thing and keep the parsed value of MAXFWD hdr incremented
* by one in order to make difference between 0 (not set)
* and 0 (zero value) - bogdan */
#define IS_MAXWD_STORED(_msg_) \
((_msg_)->maxforwards->parsed)
#define STORE_MAXWD_VAL(_msg_,_val_) \
(_msg_)->maxforwards->parsed = ((void*)(long)((_val_)+1))
#define FETCH_MAXWD_VAL(_msg_) \
(((int)(long)(_msg_)->maxforwards->parsed)-1)
/* looks for the MAX FORWARDS header
returns its value, -1 if is not present or -2 for error */
int is_maxfwd_present( struct sip_msg* msg , str *foo)
{
int x, err;
/* lookup into the message for MAX FORWARDS header*/
if ( !msg->maxforwards ) {
if ( parse_headers( msg , HDR_MAXFORWARDS_F, 0 )==-1 ){
LM_ERR("parsing MAX_FORWARD header failed!\n");
return -2;
}
if (!msg->maxforwards) {
LM_DBG("max_forwards header not found!\n");
return -1;
}
} else if (IS_MAXWD_STORED(msg)) {
trim_len( foo->len , foo->s , msg->maxforwards->body );
return FETCH_MAXWD_VAL(msg);
}
/* if header is present, trim to get only the string containing numbers */
trim_len( foo->len , foo->s , msg->maxforwards->body );
/* convert from string to number */
x = str2s( foo->s,foo->len,&err);
if (err){
LM_ERR("unable to parse the max forwards number\n");
return -2;
}
/* store the parsed values */
STORE_MAXWD_VAL(msg, x);
LM_DBG("value = %d \n",x);
return x;
}
int decrement_maxfwd( struct sip_msg* msg , int x, str *s)
{
int i;
/* decrement the value */
x--;
/* update the stored value */
STORE_MAXWD_VAL(msg, x);
/*rewriting the max-fwd value in the message (buf and orig)*/
for(i = s->len - 1; i >= 0; i--) {
s->s[i] = (x % 10) + '0';
x /= 10;
if (x==0) {
i = i - 1;
break;
}
}
while(i >= 0) s->s[i--] = ' ';
return 0;
}
int add_maxfwd_header( struct sip_msg* msg , unsigned int val )
{
unsigned int len;
char *buf;
struct lump* anchor;
/* constructing the header */
len = MF_HDR_LEN /*"MAX-FORWARDS: "*/+ CRLF_LEN + 3/*val max on 3 digits*/;
buf = (char*)pkg_malloc( len );
if (!buf) {
LM_ERR("add_maxfwd_header: no more pkg memory\n");
goto error;
}
memcpy( buf , MF_HDR, MF_HDR_LEN );
len = MF_HDR_LEN ;
len += btostr( buf+len , val );
memcpy( buf+len , CRLF , CRLF_LEN );
len +=CRLF_LEN;
/*inserts the header at the beginning of the message*/
anchor = anchor_lump(msg, msg->headers->name.s - msg->buf, 0 , 0);
if (anchor == 0) {
LM_ERR("add_maxfwd_header: failed to get anchor\n");
goto error1;
}
if (insert_new_lump_before(anchor, buf, len, 0) == 0) {
LM_ERR("add_maxfwd_header: failed to insert MAX-FORWARDS lump\n");
goto error1;
}
return 0;
error1:
pkg_free( buf );
error:
return -1;
}