net_udp_server.c

UDP echo server example.

UDP echo server example.Demonstrates: bj_open_udp, bj_udp_recv, bj_udp_send, bj_datagram_* accessors. Pair with udp_client.c to test.

 
#include <banjo/log.h>
#include <banjo/main.h>
#include <banjo/net.h>
#include <banjo/system.h>
 
#define PORT 9000
 
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("0.0.0.0", PORT, BJ_RESOLVE_IPV4, &error);
    if (!udp) {
        bj_err("server: failed to open UDP socket (%s)", bj_error_message(error));
        bj_clear_error(&error);
        bj_end();
        return 1;
    }
 
    bj_info("server: listening on port %d", bj_udp_local_port(udp));
    bj_info("server: waiting for datagrams...");
 
    while (1) {
        struct bj_datagram* dgram = bj_udp_recv(udp, &error);
        if (!dgram) {
            if (error) {
                bj_err("server: recv error (%s)", bj_error_message(error));
                bj_clear_error(&error);
            }
            continue;
        }
 
        char addr[BJ_ADDR_STRLEN];
        bj_datagram_addr(dgram, addr, sizeof(addr));
        uint16_t sender_port = bj_datagram_port(dgram);
 
        bj_info("server: received %zu bytes from %s:%d",
                bj_datagram_len(dgram), addr, sender_port);
 
        // Echo the data back
        int sent = bj_udp_send(udp, addr, sender_port,
                               bj_datagram_data(dgram), bj_datagram_len(dgram), &error);
        if (sent < 0) {
            bj_err("server: send error (%s)", bj_error_message(error));
            bj_clear_error(&error);
        } else {
            bj_info("server: echoed %d bytes back", sent);
        }
 
        bj_close_datagram(dgram);
    }
 
    bj_close_udp(udp);
    bj_end();
    return 0;
}