UDP OS X exploration

Makefile

default:
	clang udp.c -o udp

clean:
	rm udp

udp.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <sys/types.h>
#include <sys/socket.h>

#include <arpa/inet.h>
#include <netinet/ip.h>

#include <errno.h>

#define BUF_LEN 2048
#define PORT 4000

/* helper functions */

int get_socket()
{
    int sock = 0;
    struct sockaddr_in addr;

    if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
    {
        perror("Error creating socket");
        exit(EXIT_FAILURE);
    }

    addr.sin_family = AF_INET;
    addr.sin_port = htons(PORT);
    addr.sin_addr.s_addr = htonl(INADDR_ANY);

    if (bind(sock, (const struct sockaddr*) &addr, sizeof(struct sockaddr_in)))
    {
        perror("Error binding socket");
        exit(EXIT_FAILURE);
    }

    return sock;
}

void receive_loop(int socket)
{
    uint8_t buf[BUF_LEN];
    ssize_t recv_len = 0;

    while ((recv_len = recv(socket, buf, BUF_LEN, 0)) > 0)
    {
        fprintf(stdout, "Received Message: %*s\n", (int) recv_len, buf);
    }

    perror("Socket error on recv");
    exit(EXIT_FAILURE);
}

/* main */

int main(int argc, char* argv[])
{
    int socket = 0;

    fprintf(stdout, "-- Getting socket -- \n");
    socket = get_socket();
    
    fprintf(stdout, "-- Looping for packets --\n");
    receive_loop(socket);

    return EXIT_SUCCESS;
}