Simple DCCP client/server test

dccptest.c

/*
 * Compile:
 *
 *   gcc dccptest.c -o server -Wall
 *   ln -s server client
 *
 * Invoke:
 *
 *   ./client
 *   ./server
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libgen.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/inet.h>

#define SOL_DCCP 269
#define MAX_DCCP_CONNECTION_BACK_LOG 5
#define MY_PORT_NUM 62325

static void die(const char *s) {
        perror(s);
        exit(1);
}

static void server(void) {
        int ret, listen_fd;
        unsigned int one = 1;
        struct sockaddr_in servaddr = {
                .sin_family = AF_INET,
                .sin_addr.s_addr = htonl(INADDR_ANY),
                .sin_port = htons(MY_PORT_NUM),
        };

        listen_fd = socket(AF_INET, SOCK_DCCP, IPPROTO_DCCP);
        if (listen_fd < 0)
                die("socket");

        ret = setsockopt(listen_fd, SOL_DCCP, SO_REUSEADDR, (const char *) &one, sizeof(one));
        if (ret < 0)
                die("setsockopt(SO_REUSEADDR)");

        ret = bind(listen_fd, (struct sockaddr *) &servaddr, sizeof(servaddr));
        if (ret < 0)
                die("bind");

        ret = listen(listen_fd, MAX_DCCP_CONNECTION_BACK_LOG);
        if (ret < 0)
                die("listen");

        for (;;) {
                char buffer[1024];
                int conn_fd, in;

                printf("Waiting for connection\n");
                fflush(stdout);

                conn_fd = accept(listen_fd, NULL, NULL);
                if (conn_fd < 0)
                        die("accept()");

                printf("New client connected\n");
                fflush(stdout);

                in = recv(conn_fd, buffer, sizeof(buffer), 0);
                if (in > 0) {
                        printf("Received data: %s\n", buffer);
                        fflush(stdout);
                }

                close(conn_fd);
        }
}

static void client(void) {
        int ret, socket_fd;
        unsigned int one = 1;
        const char *msg = "Hello, Server!";
        struct sockaddr_in servaddr = {
                .sin_family = AF_INET,
                .sin_port = htons(MY_PORT_NUM),
        };

        socket_fd = socket(AF_INET, SOCK_DCCP, IPPROTO_DCCP);
        if (socket_fd < 0)
                die("socket");

        ret = setsockopt(socket_fd, SOL_DCCP, SO_REUSEADDR, (const char *) &one, sizeof(one));
        if (ret < 0)
                die("setsockopt(SO_REUSEADDR)");

        ret = connect(socket_fd, (struct sockaddr *) &servaddr, sizeof(servaddr));
        if (ret < 0)
                die("connect");

        ret = send(socket_fd, msg, strlen(msg) + 1, 0);
        if (ret < 0)
                die("send");
}

int main(int argc, char **argv) {

        if (strstr(basename(argv[0]), "server"))
                server();
        else
                client();

        return 0;
}