wapproxy.c

The Kannel Open Source WAP and SMS gateway works as both an SMS gateway, for implementing keyword b

        error(0, "updc_create: could not resolve interface <%s>", interface_name);
        close(udpc->fd);
        gw_free(udpc);
        return NULL;
    }

    fl = fcntl(udpc->fd, F_GETFL);
    fcntl(udpc->fd, F_SETFL, fl | O_NONBLOCK);

    os = udp_get_ip(udpc->addr);
    debug("wap.proxy",0, "bound to UDP <%s:%d>",
          octstr_get_cstr(os), udp_get_port(udpc->addr));

    octstr_destroy(os);
    
    udpc->outgoing_list = list_create();

    return udpc;
}    


static void udpc_destroy(Udpc *udpc)
{
    if (udpc == NULL)
        return;

    if (udpc->fd >= 0)
        close(udpc->fd);
    octstr_destroy(udpc->addr);
    gw_assert(list_len(udpc->outgoing_list) == 0);
    list_destroy(udpc->outgoing_list, NULL);

    gw_free(udpc);
}    


static int add_service(int port, char *interface_name, Octstr *map_addr)
{
    Udpc *udpc;
    
    if ((udpc = udpc_create(port, interface_name, map_addr)) == NULL)
        goto error;
    list_add_producer(udpc->outgoing_list);

    udpc->receiver = gwthread_create(udp_receiver, udpc);
    if (udpc->receiver == -1)
        goto error;

    if (gwthread_create(udp_sender, udpc) == -1)
        goto error;

    list_append(udpc_list, udpc);
    return 0;
    
error:    
    error(0, "Failed to start UDP receiver/sender thread");
    udpc_destroy(udpc);
    return -1;
}
 

/*-------------------------------------------------------------
 * main calling functions
 *
 */

static int udp_start(Cfg *cfg)
{

    if (udp_running) return -1;
    
    debug("wap.proxy", 0, "starting UDP sender/receiver module");

    udpc_list = list_create();	/* have a list of running systems */

    add_service(CONNECTION_ORIENTED_PORT, 
                octstr_get_cstr(interface_name), NULL);  /* wsp/wtp */
    
    list_add_producer(incoming_wdp);
    udp_running = 1;
    return 0;
}


static Udpc *udpc_find_mapping(Msg *msg, int inbound)
{
    int i;
    Udpc *udpc;
    Octstr *addr;
    
    /* check if there is allready a bound UDP port */
    list_lock(udpc_list);
    for (i=0; i < list_len(udpc_list); i++) {
        udpc = list_get(udpc_list, i);

        /* decide if we compare against inbound or outbound traffic mapping */
        addr = inbound ? udpc->map_addr : udpc->addr;

        if (msg->wdp_datagram.source_port == udp_get_port(addr) &&
            octstr_compare(msg->wdp_datagram.source_address, 
                           udp_get_ip(addr)) == 0) {
            list_unlock(udpc_list);
            return udpc;
        }
    }
    list_unlock(udpc_list);
    return NULL;
}


/*
 * this function receives an WDP message and adds it to
 * corresponding outgoing_list.
 */
static int udp_addwdp_from_server(Msg *msg)
{
    Udpc *udpc;
    Octstr *os;
    Octstr *source;

    if (!udp_running) return -1;
    assert(msg != NULL);
    assert(msg_type(msg) == wdp_datagram);

    octstr_destroy(msg->wdp_datagram.source_address);
    msg->wdp_datagram.source_address = 
        octstr_create(octstr_get_cstr(msg->wdp_datagram.destination_address));
    msg->wdp_datagram.source_port = msg->wdp_datagram.destination_port;

    if ((udpc = udpc_find_mapping(msg, 0)) == NULL) 
        /* there should have been one */
        panic(0,"Could not find UDP mapping, internal error");

    /* insert the found mapped destination */
    octstr_destroy(msg->wdp_datagram.source_address);
    octstr_destroy(msg->wdp_datagram.destination_address);
    
    msg->wdp_datagram.destination_address = udp_get_ip(udpc->map_addr);
    msg->wdp_datagram.destination_port = udp_get_port(udpc->map_addr);

    /* now search for our inbound UDP socket */
    os = octstr_duplicate(interface_name);
    source = udp_create_address(os, CONNECTION_ORIENTED_PORT);

    msg->wdp_datagram.source_address = udp_get_ip(source);
    msg->wdp_datagram.source_port = udp_get_port(source);
    if ((udpc = udpc_find_mapping(msg, 0)) == NULL) 
        panic(0,"Could not find main inbound UDP socket, internal error");

    /* 
     * ok, got the destination, got the socket, 
     * now put it on the outbound queue
     */
    list_produce(udpc->outgoing_list, msg);

    octstr_destroy(os);

    return 0;
}


/*
 * this function receives an WDP message and checks if a UDP
 * service for this client has to be created
 */
static int udp_addwdp_from_client(Msg *msg)
{
    Udpc *udpc;
    Octstr *map_addr;
    Octstr *os;
    Octstr *source;
    
    if (!udp_running) return -1;
    assert(msg != NULL);
    assert(msg_type(msg) == wdp_datagram);
    
    /* 
     * Check if there is allready a bound UDP port for this mapping.
     * If not create a mapping and bind the mapped UDP port
     * The mapped port is simply 2x of the client port. 
     */
    if ((udpc = udpc_find_mapping(msg, 1)) == NULL) {
        info(0, "Creating UDP mapping <%s:%ld> <-> <%s:%ld>",
              octstr_get_cstr(msg->wdp_datagram.source_address),
              msg->wdp_datagram.source_port,
              octstr_get_cstr(msg->wdp_datagram.destination_address),
              msg->wdp_datagram.source_port*2);

        map_addr = udp_create_address(msg->wdp_datagram.source_address, 
                                      msg->wdp_datagram.source_port);
        add_service(msg->wdp_datagram.source_port * 2, 
                    octstr_get_cstr(interface_name), map_addr);
        /* now we should find it in the udpc_list */
        if ((udpc = udpc_find_mapping(msg, 1)) == NULL)
            panic(0,"Could not find UDP mapping, internal error");
    }

    /* now swap the message addressing */
    octstr_destroy(msg->wdp_datagram.source_address);
    octstr_destroy(msg->wdp_datagram.destination_address);

    os = octstr_duplicate(interface_name);
    source = udp_create_address(os, msg->wdp_datagram.source_port * 2);
    msg->wdp_datagram.source_address = udp_get_ip(source);
    msg->wdp_datagram.source_port = udp_get_port(source);
    msg->wdp_datagram.destination_address = octstr_duplicate(wapgw);
    msg->wdp_datagram.destination_port = CONNECTION_ORIENTED_PORT;

    octstr_destroy(os);

    list_produce(udpc->outgoing_list, msg);
    
    return -1;
}


static int udp_shutdown(void)
{
    if (!udp_running) return -1;

    debug("bb.thread", 0, "udp_shutdown: Starting avalanche");
    list_remove_producer(incoming_wdp);
    return 0;
}


static int udp_die(void)
{
    Udpc *udpc;

    if (!udp_running) return -1;
    
    /*
     * remove producers from all outgoing lists.
     */
    debug("bb.udp", 0, "udp_die: removing producers from udp-lists");

    while ((udpc = list_consume(udpc_list)) != NULL) {
        list_remove_producer(udpc->outgoing_list);
    }
    list_destroy(udpc_list, NULL);
    udp_running = 0;
    
    return 0;
}


/*-------------------------------------------------------------
 * main consumer threads
 *
 */

static void wdp_router(void *arg)
{
    Msg *msg;

    list_add_producer(flow_threads);
    
    while (1) {

        if ((msg = list_consume(outgoing_wdp)) == NULL)
            break;

        gw_assert(msg_type(msg) == wdp_datagram);
	
        udp_addwdp_from_server(msg);
    }
    udp_die();

    list_remove_producer(flow_threads);
}


static void service_router(void *arg)
{
    Msg *msg;

    list_add_producer(flow_threads);
    
    while (1) {

        if ((msg = list_consume(incoming_wdp)) == NULL)
            break;

        gw_assert(msg_type(msg) == wdp_datagram);
	
        udp_addwdp_from_client(msg);
    }
    udp_die();

    list_remove_producer(flow_threads);
}


/*-------------------------------------------------------------
 * main functions
 *
 */

static void help(void) 
{
    info(0, "Usage: wapproxy [options] host ...");
    info(0, "where host is the real wap gw to forward to and options are:");
    info(0, "-v number");
    info(0, "    set log level for stderr logging");
    info(0, "-i interface");
    info(0, "    bind to the given interface for UDP sockets");
    info(0, "-m");
    info(0, "    dump WDP/UDP packets, msg_dump()");
    info(0, "-e");
    info(0, "    dump WAP event packets, wap_event_dump()");
    info(0, "-t");
    info(0, "    dump WTP PDUs, wtp_pdu_dump()");
}


int main(int argc, char **argv) 
{
    int opt;
    Cfg *cfg = NULL;
	
	gwlib_init();

    while ((opt = getopt(argc, argv, "v:meti:")) != EOF) {

        switch (opt) {
            case 'v':
                log_set_output_level(atoi(optarg));
                break;

            case 'm':
                verbose += 1;                                           
                break;

            case 'e':
                verbose += 2;
                break;

            case 't':
                verbose += 4;
                break;


            case 'h':
                help();
                exit(0);

            case 'i':
                interface_name = octstr_create(optarg);
                break;

            case '?':
            default:
                error(0, "Invalid option %c", opt);
                help();
                panic(0, "Stopping.");
        }
    }
    
    if (optind == argc) {
        help();
        exit(0);
    }

    /* get the host or IP of the real wap gw to forward the WDP packets */
    wapgw = octstr_create(argv[optind]);

    /* if no interface was given use 0.0.0.0 */
    if (!interface_name)
        interface_name = octstr_create("*");

    report_versions("wapproxy");

    /* initialize main inbound and outbound queues */
    outgoing_wdp = list_create();
    incoming_wdp = list_create();
    flow_threads = list_create();

    outgoing_wdp_counter = counter_create();
    incoming_wdp_counter = counter_create();

    /* start the main UDP listening threads */
    udp_start(cfg);

    list_add_producer(outgoing_wdp);    
    
    debug("bb", 0, "starting WDP routers");
    if (gwthread_create(service_router, NULL) == -1)
        panic(0, "Failed to start a new thread for inbound WDP routing");
    if (gwthread_create(wdp_router, NULL) == -1)
        panic(0, "Failed to start a new thread for outbound WDP routing");

    gwthread_sleep(5.0); /* give time to threads to register themselves */

    while (list_consume(flow_threads) != NULL)
	;

    udp_shutdown();

    list_remove_producer(outgoing_wdp);

    list_destroy(flow_threads, NULL);
    list_destroy(incoming_wdp, NULL);
    list_destroy(outgoing_wdp, NULL);

    counter_destroy(incoming_wdp_counter);
    counter_destroy(outgoing_wdp_counter);
    octstr_destroy(interface_name);
    octstr_destroy(wapgw);

    gwlib_shutdown();

	return 0;
}