kamailio/modules_k/path/path.c

/*
 * $Id$
 *
 * Path handling for intermediate proxies.
 *
 * Copyright (C) 2006 Inode GmbH (Andreas Granig <andreas.granig@inode.info>)
 *
 * 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
 *
 */

/*! \file
 * \brief Path :: Utilities
 *
 * \ingroup path
 * - Module: path
 */

#include <string.h>
#include <stdio.h>

#include "../../mem/mem.h"
#include "../../data_lump.h"
#include "../../parser/parse_param.h"
#include "../../lib/kcore/strcommon.h"
#include "../../dset.h"
#include "../../sr_module.h"

#include "path.h"
#include "path_mod.h"

#define PATH_PREFIX		"Path: <sip:"
#define PATH_PREFIX_LEN		(sizeof(PATH_PREFIX)-1)

const static char *proto_strings[] = {
	[PROTO_TCP] = "%3Btransport%3Dtcp",
	[PROTO_TLS] = "%3Btransport%3Dtls",
	[PROTO_SCTP] = "%3Btransport%3Dsctp",
};

static int prepend_path(struct sip_msg* _m, str *user, int recv, str *parms)
{
	struct lump *l;
	char *prefix, *suffix, *cp;
	const char *proto_str;
	int prefix_len, suffix_len;
	struct hdr_field *hf;
		
	suffix_len = strlen(";lr;received=sip::12345%3Btransport%3Dsctp;>\r\n")
			+ IP_ADDR_MAX_STR_SIZE + (parms ? parms->len : 0) + 1;
	cp = suffix = pkg_malloc(suffix_len);
	if (!suffix) {
		LM_ERR("no pkg memory left for suffix\n");
		goto out1;
	}

	cp += sprintf(cp, ";lr");

	if (recv) {
		if (_m->rcv.proto < (sizeof(proto_strings) / sizeof(*proto_strings)))
			proto_str = proto_strings[(unsigned int) _m->rcv.proto];
		else
			proto_str = NULL;

		cp += sprintf(cp, ";received=sip:%s:%hu%s", ip_addr2a(&_m->rcv.src_ip),
				_m->rcv.src_port, proto_str ? : "");
	}

	if (parms && parms->len)
		cp += sprintf(cp, ";%.*s", parms->len, parms->s);

	cp += sprintf(cp, ">\r\n");

	prefix_len = PATH_PREFIX_LEN + (user ? user->len : 0) + 2;
	prefix = pkg_malloc(prefix_len);
	if (!prefix) {
		LM_ERR("no pkg memory left for prefix\n");
		goto out2;
	}
	if (user && user->len)
		prefix_len = sprintf(prefix, PATH_PREFIX "%.*s@", user->len, user->s);
	else
		prefix_len = sprintf(prefix, PATH_PREFIX);

	if (parse_headers(_m, HDR_PATH_F, 0) < 0) {
		LM_ERR("failed to parse message for Path header\n");
		goto out3;
	}
	hf = get_hdr(_m, HDR_PATH_T);
	if (hf)
		/* path found, add ours in front of that */
		l = anchor_lump(_m, hf->name.s - _m->buf, 0, 0);
	else
		/* no path, append to message */
		l = anchor_lump(_m, _m->unparsed - _m->buf, 0, 0);
	if (!l) {
		LM_ERR("failed to get anchor\n");
		goto out3;
	}

	l = insert_new_lump_before(l, prefix, prefix_len, 0);
	if (!l) goto out3;
	l = insert_subst_lump_before(l, SUBST_SND_ALL, 0);
	if (!l) goto out2;
	l = insert_new_lump_before(l, suffix, cp - suffix, 0);
	if (!l) goto out2;
	
	return 1;
	
out3:
	pkg_free(prefix);
out2:
	pkg_free(suffix);
out1:
	LM_ERR("failed to insert Path header\n");

	return -1;
}

static int add_path_rcv(struct sip_msg* _msg, char* _usr, int recv, char* _parms) {
	str user = {0,0};
	str parms = {0,0};

	if (_usr)
		get_str_fparam(&user, _msg, (fparam_t *) _usr);
	if (_parms)
		get_str_fparam(&parms, _msg, (fparam_t *) _parms);

	return prepend_path(_msg, &user, recv, &parms);
}

/*! \brief
 * Prepend own uri to Path header and take care of given
 * params.
 */
int add_path(struct sip_msg* _msg, char* _usr, char* _parms)
{
	return add_path_rcv(_msg, _usr, 0, _parms);
}

/*! \brief
 * Prepend own uri to Path header and append received address as
 * "received"-param to that uri.
 */
int add_path_received(struct sip_msg* _msg, char* _usr, char* _parms)
{
	return add_path_rcv(_msg, _usr, 1, _parms);
}

/*! \brief
 * rr callback
 */
void path_rr_callback(struct sip_msg *_m, str *r_param, void *cb_param)
{
	param_hooks_t hooks;
	param_t *params;
	static char dst_uri_buf[MAX_URI_SIZE];
	static str dst_uri;
			
	if (parse_params(r_param, CLASS_CONTACT, &hooks, &params) != 0) {
		LM_ERR("failed to parse route parameters\n");
		return;
	}

	if (hooks.contact.received) {
	        dst_uri.s = dst_uri_buf;
		dst_uri.len = MAX_URI_SIZE;
		if (unescape_user(&(hooks.contact.received->body), &dst_uri) < 0) {
		        LM_ERR("unescaping received failed\n");
			free_params(params);
			return;
		}	    
		if (set_dst_uri(_m, &dst_uri) != 0) {
			LM_ERR("failed to set dst-uri\n");
			free_params(params);
			return;
		}
		/* dst_uri changed, so it makes sense to re-use the current uri for
			forking */
		ruri_mark_new(); /* re-use uri for serial forking */
	}
	free_params(params);
}