/* Copyright 2000-2004 The Apache Software Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

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

int main(void) {
    int listen_s, connected_s, client_s;
    int listen_port, rc;
    struct sockaddr_in sa;
    socklen_t sa_len;

    listen_s = socket(AF_INET, SOCK_STREAM, 0);
    if (listen_s < 0) {
        perror("socket");
        exit(1);
    }
    memset(&sa, 0, sizeof sa);
    sa.sin_family = AF_INET;
#ifdef BEOS
    sa.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
#endif
    /* leave port 0 to get ephemeral */
    rc = bind(listen_s, (struct sockaddr *)&sa, sizeof sa);
    if (rc < 0) {
        perror("bind for ephemeral port");
        exit(1);
    }
    /* find ephemeral port */
    sa_len = sizeof(sa);
    rc = getsockname(listen_s, (struct sockaddr *)&sa, &sa_len);
    if (rc < 0) {
        perror("getsockname");
        exit(1);
    }
    listen_port = sa.sin_port;
    rc = listen(listen_s, 5);
    if (rc < 0) {
        perror("listen");
        exit(1);
    }
    rc = fcntl(listen_s, F_SETFL, O_NONBLOCK);
    if (rc < 0) {
        perror("fcntl(F_SETFL)");
        exit(1);
    }
    client_s = socket(AF_INET, SOCK_STREAM, 0);
    if (client_s < 0) {
        perror("socket");
        exit(1);
    }
    memset(&sa, 0, sizeof sa);
    sa.sin_family = AF_INET;
    sa.sin_port   = listen_port;
#ifdef BEOS
    sa.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
#endif
    printf("bound to %s:%d\n", inet_ntoa(sa.sin_addr), listen_port);
    /* leave sin_addr all zeros to use loopback */
    rc = connect(client_s, (struct sockaddr *)&sa, sizeof sa);
    if (rc < 0) {
        perror("connect");
        exit(1);
    }
    sa_len = sizeof sa;
    connected_s = accept(listen_s, (struct sockaddr *)&sa, &sa_len);
    if (connected_s < 0) {
        perror("accept");
        exit(1);
    }
    rc = fcntl(connected_s, F_GETFL, 0);
    if (rc < 0) {
        perror("fcntl(F_GETFL)");
        exit(1);
    }
    if (!(rc & O_NONBLOCK)) {
        fprintf(stderr, "O_NONBLOCK is not set in the child.\n");
        exit(1);
    }
    return 0;
}