net_udp_broadcast_send.c

UDP broadcast sender for LAN discovery.

UDP broadcast sender for LAN discovery.Demonstrates: BJ_BROADCAST hint, sending to broadcast address. Pair with udp_broadcast_recv.c to test.

 
#include <banjo/log.h>
#include <banjo/main.h>
#include <banjo/net.h>
#include <banjo/system.h>
#include <banjo/time.h>
 
#include <stdio.h>
 
#define PORT 9999
#define BROADCAST_ADDR "255.255.255.255"
 
int main(int argc, char* argv[]) {
    (void)argc;
    (void)argv;
 
    if (!bj_begin(BJ_NETWORK_SYSTEM, 0)) {
        return 1;
    }
 
    struct bj_error* error = 0;
 
    struct bj_udp* udp = bj_open_udp(0, 0, BJ_BROADCAST | BJ_RESOLVE_IPV4, &error);
    if (!udp) {
        bj_err("broadcast: failed to open socket (%s)", bj_error_message(error));
        bj_clear_error(&error);
        bj_end();
        return 1;
    }
 
    bj_info("broadcast: sending announcements on port %d", PORT);
 
    int count = 0;
    while (1) {
        char message[128];
        int len = snprintf(message, sizeof(message), "BANJO_SERVICE:ping:%d", count++);
 
        int sent = bj_udp_send(udp, BROADCAST_ADDR, PORT, message, len, &error);
        if (sent < 0) {
            bj_err("broadcast: send failed (%s)", bj_error_message(error));
            bj_clear_error(&error);
        } else {
            bj_info("broadcast: sent \"%s\"", message);
        }
 
        bj_sleep(2000);
    }
 
    bj_close_udp(udp);
    bj_end();
    return 0;
}