connect_timeout.c

/*
 * MIT License
 *
 * Copyright (c) 2018 Lewis Van Winkle
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include "chap13.h"

#if defined(_WIN32)
#define INPROGRESS WSAEWOULDBLOCK
#else
#define INPROGRESS EINPROGRESS
#endif

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

#if defined(_WIN32)
    WSADATA d;
    if (WSAStartup(MAKEWORD(2, 2), &d)) {
        fprintf(stderr, "Failed to initialize.\n");
        return 1;
    }
#endif

    if (argc < 3) {
        fprintf(stderr, "usage: connect_timeout hostname port\n");
        return 1;
    }

    printf("Configuring remote address...\n");
    struct addrinfo hints;
    memset(&hints, 0, sizeof(hints));
    hints.ai_socktype = SOCK_STREAM;
    struct addrinfo *peer_address;
    if (getaddrinfo(argv[1], argv[2], &hints, &peer_address)) {
        fprintf(stderr, "getaddrinfo() failed. (%d)\n", GETSOCKETERRNO());
        return 1;
    }


    printf("Remote address is: ");
    char address_buffer[100];
    char service_buffer[100];
    getnameinfo(peer_address->ai_addr, peer_address->ai_addrlen,
            address_buffer, sizeof(address_buffer),
            service_buffer, sizeof(service_buffer),
            NI_NUMERICHOST);
    printf("%s %s\n", address_buffer, service_buffer);


    printf("Creating socket...\n");
    SOCKET socket_peer;
    socket_peer = socket(peer_address->ai_family,
            peer_address->ai_socktype, peer_address->ai_protocol);
    if (!ISVALIDSOCKET(socket_peer)) {
        fprintf(stderr, "socket() failed. (%d)\n", GETSOCKETERRNO());
        return 1;
    }


#if defined(_WIN32)
    unsigned long nonblock = 1;
    ioctlsocket(socket_peer, FIONBIO, &nonblock);
#else
    int flags;
    flags = fcntl(socket_peer, F_GETFL, 0);
    fcntl(socket_peer, F_SETFL, flags | O_NONBLOCK);
#endif

    printf("Connecting...\n");
    int ret;
    if ((ret = connect(socket_peer,
                peer_address->ai_addr, peer_address->ai_addrlen))) {
        if (GETSOCKETERRNO() != INPROGRESS) {
            fprintf(stderr, "connect() failed. (%d)\n", GETSOCKETERRNO());
            return 1;
        }
    }

    freeaddrinfo(peer_address);

#if defined(_WIN32)
    nonblock = 0;
    ioctlsocket(socket_peer, FIONBIO, &nonblock);
#else
    fcntl(socket_peer, F_SETFL, flags);
#endif


    if (ret == 0) {
        printf("Already connected.\n");
        printf("Perhaps non-blocking failed?\n");

    } else {
        printf("Waiting up to 5 seconds for connection...\n");

        fd_set set;
        FD_ZERO(&set);
        FD_SET(socket_peer, &set);

        struct timeval timeout;
        timeout.tv_sec = 5; timeout.tv_usec = 0;
        select(socket_peer+1, 0, &set, 0, &timeout);
    }


    printf("Testing for connection...\n");
    if (send(socket_peer, "a", 1, 0) < 0) {
        printf("First send() failed. Connection was not successful.\n");
    } else {
        printf("First send() succeeded. Connection was successful.\n");
    }


    printf("Closing socket...\n");
    CLOSESOCKET(socket_peer);

#if defined(_WIN32)
    WSACleanup();
#endif

    printf("Finished.\n");
    return 0;
}