Samples: Stateless SIP Endpoint

This is about the simplest SIP application with PJSIP, all it does is respond all incoming requests with 501 (Not Implemented) response statelessly.

/* 
 * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
 * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
 *
 * This program 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.
 *
 * This program 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 all headers. */
#include <pjsip.h>
#include <pjlib-util.h>
#include <pjlib.h>
 
 
/* If this macro is set, UDP transport will be initialized at port 5060 */
#define HAS_UDP_TRANSPORT
 
/* If this macro is set, TCP transport will be initialized at port 5060 */
#define HAS_TCP_TRANSPORT   (1 && PJ_HAS_TCP)
 
/* Log identification */
#define THIS_FILE       "sipstateless.c"
 
 
/* Global SIP endpoint */
static pjsip_endpoint *sip_endpt;
 
/* What response code to be sent (default is 501/Not Implemented) */
static int code = PJSIP_SC_NOT_IMPLEMENTED;
 
/* Additional header list */
struct pjsip_hdr hdr_list;
 
/* usage() */
static void usage(void)
{
    puts("Usage:");
    puts("  sipstateless [code] [-H HDR] ..");
    puts("");
    puts("Options:");
    puts("  code     SIP status code to send (default: 501/Not Implemented");
    puts("  -H HDR   Specify additional headers to send with response");
    puts("           This option may be specified more than once.");
    puts("           Example:");
    puts("              -H 'Expires: 300' -H 'Contact: <sip:localhost>'"); 
}
 
 
/* Callback to handle incoming requests. */
static pj_bool_t on_rx_request( pjsip_rx_data *rdata )
{
    /* Respond (statelessly) all incoming requests (except ACK!) 
     * with 501 (Not Implemented)
     */
    if (rdata->msg_info.msg->line.req.method.id != PJSIP_ACK_METHOD) {
        pjsip_endpt_respond_stateless( sip_endpt, rdata, 
                                       code, NULL,
                                       &hdr_list, NULL);
    }
    return PJ_TRUE;
}
 
 
 
/*
 * main()
 *
 */
int main(int argc, char *argv[])
{
    pj_caching_pool cp;
    pj_pool_t *pool = NULL;
    pjsip_module mod_app =
    {
        NULL, NULL,                 /* prev, next.              */
        { "mod-app", 7 },           /* Name.                    */
        -1,                                 /* Id               */
        PJSIP_MOD_PRIORITY_APPLICATION, /* Priority             */
        NULL,                       /* load()                   */
        NULL,                       /* start()                  */
        NULL,                       /* stop()                   */
        NULL,                       /* unload()                 */
        &on_rx_request,             /* on_rx_request()          */
        NULL,                       /* on_rx_response()         */
        NULL,                       /* on_tx_request.           */
        NULL,                       /* on_tx_response()         */
        NULL,                       /* on_tsx_state()           */
    };
    int c;
    pj_status_t status;
    
    /* Must init PJLIB first: */
    status = pj_init();
    PJ_ASSERT_RETURN(status == PJ_SUCCESS, 1);
 
 
    /* Then init PJLIB-UTIL: */
    status = pjlib_util_init();
    PJ_ASSERT_RETURN(status == PJ_SUCCESS, 1);
 
    /* Must create a pool factory before we can allocate any memory. */
    pj_caching_pool_init(&cp, &pj_pool_factory_default_policy, 0);
 
    /* Create global endpoint: */
    {
        /* Endpoint MUST be assigned a globally unique name.
         * Ideally we should put hostname or public IP address, but
         * we'll just use an arbitrary name here.
         */
 
        /* Create the endpoint: */
        status = pjsip_endpt_create(&cp.factory, "sipstateless", 
                                    &sip_endpt);
        PJ_ASSERT_RETURN(status == PJ_SUCCESS, 1);
    }
 
    /* Parse arguments */
    pj_optind = 0;
    pj_list_init(&hdr_list);
    while ((c=pj_getopt(argc, argv , "H:")) != -1) {
        switch (c) {
        case 'H':
            if (pool == NULL) {
                pool = pj_pool_create(&cp.factory, "sipstateless", 1000, 
                                      1000, NULL);
            } 
            
            if (pool) {
                char *name;
                name = strtok(pj_optarg, ":");
                if (name == NULL) {
                    puts("Error: invalid header format");
                    return 1;
                } else {
                    char *val = strtok(NULL, "\r\n");
                    pjsip_generic_string_hdr *h;
                    pj_str_t hname, hvalue;
 
                    hname = pj_str(name);
                    hvalue = pj_str(val);
 
                    h = pjsip_generic_string_hdr_create(pool, &hname, &hvalue);
 
                    pj_list_push_back(&hdr_list, h);
 
                    PJ_LOG(4,(THIS_FILE, "Header %s: %s added", name, val));
                }
            }
            break;
        default:
            puts("Error: invalid argument");
            usage();
            return 1;
        }
    }
 
    if (pj_optind != argc) {
        code = atoi(argv[pj_optind]);
        if (code < 200 || code > 699) {
            puts("Error: invalid status code");
            usage();
            return 1;
        }
    }
 
    PJ_LOG(4,(THIS_FILE, "Returning %d to incoming requests", code));
 
 
    /* 
     * Add UDP transport, with hard-coded port 
     */
#ifdef HAS_UDP_TRANSPORT
    {
        pj_sockaddr_in addr;
 
        addr.sin_family = pj_AF_INET();
        addr.sin_addr.s_addr = 0;
        addr.sin_port = pj_htons(5060);
 
        status = pjsip_udp_transport_start( sip_endpt, &addr, NULL, 1, NULL);
        if (status != PJ_SUCCESS) {
            PJ_LOG(3,(THIS_FILE, 
                      "Error starting UDP transport (port in use?)"));
            return 1;
        }
    }
#endif
 
#if HAS_TCP_TRANSPORT
    /* 
     * Add UDP transport, with hard-coded port 
     */
    {
        pj_sockaddr_in addr;
 
        addr.sin_family = pj_AF_INET();
        addr.sin_addr.s_addr = 0;
        addr.sin_port = pj_htons(5060);
 
        status = pjsip_tcp_transport_start(sip_endpt, &addr, 1, NULL);
        if (status != PJ_SUCCESS) {
            PJ_LOG(3,(THIS_FILE, 
                      "Error starting TCP transport (port in use?)"));
            return 1;
        }
    }
#endif
 
    /*
     * Register our module to receive incoming requests.
     */
    status = pjsip_endpt_register_module( sip_endpt, &mod_app);
    PJ_ASSERT_RETURN(status == PJ_SUCCESS, 1);
 
 
    /* Done. Loop forever to handle incoming events. */
    PJ_LOG(3,(THIS_FILE, "Press Ctrl-C to quit.."));
 
    for (;;) {
        pjsip_endpt_handle_events(sip_endpt, NULL);
    }
}