path/path.c

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/*
 * $Id$
 *
 * 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
 *
 */

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

#include "../../mem/mem.h"
#include "../../data_lump.h"
#include "../../parser/parse_param.h"
#include "../../dset.h"

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

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

#define PATH_LR_PARAM           ";lr"
#define PATH_LR_PARAM_LEN       (sizeof(PATH_LR_PARAM)-1)

#define PATH_RC_PARAM           ";received="
#define PATH_RC_PARAM_LEN       (sizeof(PATH_RC_PARAM)-1)

#define PATH_CRLF               ">\r\n"
#define PATH_CRLF_LEN           (sizeof(PATH_CRLF)-1)

static int prepend_path(struct sip_msg* _m, str *user, int recv)
{
        struct lump *l;
        char *prefix, *suffix, *crlf;
        int prefix_len, suffix_len;
        struct hdr_field *hf;
        str rcv_addr = {0, 0};
        char *src_ip;
                
        prefix = suffix = crlf = 0;

        prefix_len = PATH_PREFIX_LEN + (user->len ? (user->len+1) : 0);
        prefix = pkg_malloc(prefix_len);
        if (!prefix) {
                LM_ERR("no pkg memory left for prefix\n");
                goto out1;
        }
        memcpy(prefix, PATH_PREFIX, PATH_PREFIX_LEN);
        if (user->len) {
                memcpy(prefix + PATH_PREFIX_LEN, user->s, user->len);
                memcpy(prefix + prefix_len - 1, "@", 1);
        }

        suffix_len = PATH_LR_PARAM_LEN + (recv ? PATH_RC_PARAM_LEN : 0);
        suffix = pkg_malloc(suffix_len);
        if (!suffix) {
                LM_ERR("no pkg memory left for suffix\n");
                goto out1;
        }
        memcpy(suffix, PATH_LR_PARAM, PATH_LR_PARAM_LEN);
        if(recv)
                memcpy(suffix+PATH_LR_PARAM_LEN, PATH_RC_PARAM, PATH_RC_PARAM_LEN);

        crlf = pkg_malloc(PATH_CRLF_LEN);
        if (!crlf) {
                LM_ERR("no pkg memory left for crlf\n");
                goto out1;
        }
        memcpy(crlf, PATH_CRLF, PATH_CRLF_LEN);

        if (parse_headers(_m, HDR_PATH_F, 0) < 0) {
                LM_ERR("failed to parse message for Path header\n");
                goto out1;
        }
        for (hf = _m->headers; hf; hf = hf->next) {
                if (hf->type == HDR_PATH_T) {
                        break;
                } 
        }
        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 out1;
        }

        l = insert_new_lump_before(l, prefix, prefix_len, 0);
        if (!l) goto out1;
        l = insert_subst_lump_before(l, SUBST_SND_ALL, 0);
        if (!l) goto out2;
        l = insert_new_lump_before(l, suffix, suffix_len, 0);
        if (!l) goto out2;
        if (recv) {
                /* TODO: agranig: optimize this one! */
                src_ip = ip_addr2a(&_m->rcv.src_ip);
                rcv_addr.s = pkg_malloc(6 + IP_ADDR_MAX_STR_SIZE + 22); /* "sip:<ip>:<port>;transport=sctp"\0 */
                if(!rcv_addr.s) {
                        LM_ERR("no pkg memory left for receive-address\n");
                        goto out3;
                }
                switch (_m->rcv.proto) {
                        case PROTO_UDP:
                                rcv_addr.len = snprintf(rcv_addr.s, 6 + IP_ADDR_MAX_STR_SIZE + 6, "\"sip:%s:%u\"", src_ip, _m->rcv.src_port);
                                break;
                        case PROTO_TCP:
                                rcv_addr.len = snprintf(rcv_addr.s, 6 + IP_ADDR_MAX_STR_SIZE + 20, "\"sip:%s:%u;transport=tcp\"", src_ip, _m->rcv.src_port);
                                break;
                        case PROTO_TLS:
                                rcv_addr.len = snprintf(rcv_addr.s, 6 + IP_ADDR_MAX_STR_SIZE + 20, "\"sip:%s:%u;transport=tls\"", src_ip, _m->rcv.src_port);
                                break;
                        case PROTO_SCTP:
                                rcv_addr.len = snprintf(rcv_addr.s, 6 + IP_ADDR_MAX_STR_SIZE + 21, "\"sip:%s:%u;transport=sctp\"", src_ip, _m->rcv.src_port);
                                break;
            }

                l = insert_new_lump_before(l, rcv_addr.s, rcv_addr.len, 0);
                if (!l) goto out3;
        }
        l = insert_new_lump_before(l, crlf, CRLF_LEN+1, 0);
        if (!l) goto out4;
        
        return 1;
        
out1:
        if (prefix) pkg_free(prefix);
out2:
        if (suffix) pkg_free(suffix);
out3:
        if (rcv_addr.s) pkg_free(rcv_addr.s);
out4:
        if (crlf) pkg_free(crlf);

        LM_ERR("failed to insert prefix lump\n");

        return -1;
}

int add_path(struct sip_msg* _msg, char* _a, char* _b)
{
        str user = {0,0};
        return prepend_path(_msg, &user, 0);
}

int add_path_usr(struct sip_msg* _msg, char* _usr, char* _b)
{
        return prepend_path(_msg, (str*)_usr, 0);
}

int add_path_received(struct sip_msg* _msg, char* _a, char* _b)
{
        str user = {0,0};
        return prepend_path(_msg, &user, 1);
}

int add_path_received_usr(struct sip_msg* _msg, char* _usr, char* _b)
{
        return prepend_path(_msg, (str*)_usr, 1);
}

void path_rr_callback(struct sip_msg *_m, str *r_param, void *cb_param)
{
        param_hooks_t hooks;
        param_t *params;
                        
        if (parse_params(r_param, CLASS_CONTACT, &hooks, &params) != 0) {
                LM_ERR("failed to parse route parameters\n");
                return;
        }

        if (hooks.contact.received) {
                if (set_dst_uri(_m, &hooks.contact.received->body) != 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);
}