modules_k/diversion/diversion.c

/* 
 * $Id$
 *
 * Diversion Header Field Support
 *
 * Copyright (C) 2004 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
 *
 */

#include <stdio.h>
#include <string.h>
#include "../../sr_module.h"
#include "../../error.h"
#include "../../dprint.h"
#include "../../mem/mem.h"
#include "../../data_lump.h"
#include "../../mod_fix.h"


MODULE_VERSION

#define DIVERSION_HF "Diversion"
#define DIVERSION_HF_LEN (sizeof(DIVERSION_HF) - 1)

#define DIVERSION_PREFIX     DIVERSION_HF ": <"
#define DIVERSION_PREFIX_LEN (sizeof(DIVERSION_PREFIX) - 1)

#define DIVERSION_SUFFIX     ">;reason="
#define DIVERSION_SUFFIX_LEN (sizeof(DIVERSION_SUFFIX) - 1)



str suffix = {"", 0};

int add_diversion(struct sip_msg* msg, char* r, char* u);

/*
 * Module initialization function prototype
 */
static int mod_init(void);


/*
 * Exported functions
 */
static cmd_export_t cmds[] = {
        {"add_diversion",    (cmd_function)add_diversion,    1, fixup_spve_null,
                0, REQUEST_ROUTE|FAILURE_ROUTE|BRANCH_ROUTE},
        {"add_diversion",    (cmd_function)add_diversion,    2, fixup_spve_spve,
                0, REQUEST_ROUTE|FAILURE_ROUTE|BRANCH_ROUTE},
        {0, 0, 0, 0, 0, 0}
};


/*
 * Exported parameters
 */
static param_export_t params[] = {
        {"suffix", STR_PARAM, &suffix.s},
        {0, 0, 0}
};


/*
 * Module interface
 */
struct module_exports exports = {
        "diversion", 
        DEFAULT_DLFLAGS, /* dlopen flags */
        cmds,       /* Exported functions */
        params,     /* Exported parameters */
        0,          /* exported statistics */
        0,          /* exported MI functions */
        0,          /* exported pseudo-variables */
        0,          /* extra processes */
        mod_init,   /* module initialization function */
        0,          /* response function */
        0,          /* destroy function */
        0           /* child initialization function */
};


static int mod_init(void)
{
        suffix.len = strlen(suffix.s);
        return 0;
}


static inline int add_diversion_helper(struct sip_msg* msg, str* s)
{
        char *ptr;
        int is_ref;

        struct lump* anchor = 0;

        if (!msg->diversion && parse_headers(msg, HDR_DIVERSION_F, 0) == -1) {
                LM_ERR("header parsing failed\n");
                return -1;
        }
        
        if (msg->diversion) {
                     /* Insert just before the topmost Diversion header */
                ptr = msg->diversion->name.s;
        } else {
                     /* Insert at the end */
                ptr = msg->unparsed;
        }

        anchor = anchor_lump2(msg, ptr - msg->buf, 0, 0, &is_ref);
        if (!anchor) {
                LM_ERR("can't get anchor\n");
                return -2;
        }
        
        if (!insert_new_lump_before(anchor, s->s, s->len, 0)) {
                LM_ERR("can't insert lump\n");
                return -3;
        }

        return 0;
}


int add_diversion(struct sip_msg* msg, char* r, char* u)
{
        str div_hf;
        char *at;
        str uri;
        str reason;

        if(fixup_get_svalue(msg, (gparam_t*)r, &reason)<0)
        {
                LM_ERR("cannot get the script\n");
                return -1;
        }


        if(u==NULL) {
                uri = msg->first_line.u.request.uri;
        } else {
                if(fixup_get_svalue(msg, (gparam_t*)u, &uri)<0)
                {
                        LM_ERR("cannot get the uri parameter\n");
                        return -1;
                }
        }

        div_hf.len = DIVERSION_PREFIX_LEN + uri.len + DIVERSION_SUFFIX_LEN + reason.len + CRLF_LEN;
        div_hf.s = pkg_malloc(div_hf.len);
        if (!div_hf.s) {
                LM_ERR("no pkg memory left\n");
                return -1;
        }

        at = div_hf.s;
        memcpy(at, DIVERSION_PREFIX, DIVERSION_PREFIX_LEN);
        at += DIVERSION_PREFIX_LEN;

        memcpy(at, uri.s, uri.len);
        at += uri.len;

        memcpy(at, DIVERSION_SUFFIX, DIVERSION_SUFFIX_LEN);
        at += DIVERSION_SUFFIX_LEN;

        memcpy(at, reason.s, reason.len);
        at += reason.len;

        memcpy(at, CRLF, CRLF_LEN);

        if (add_diversion_helper(msg, &div_hf) < 0) {
                pkg_free(div_hf.s);
                return -1;
        }

        return 1;
}