lib/samples/sample-gai.c

/*
 * Copyright (C) 2009, 2012-2016  Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

/* $Id: sample-gai.c,v 1.4 2009/09/02 23:48:02 tbox Exp $ */

#include <config.h>

#include <isc/net.h>
#include <isc/print.h>

#include <irs/netdb.h>

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

static void
do_gai(int family, char *hostname) {
    struct addrinfo hints, *res, *res0;
    int error;
    char namebuf[1024], addrbuf[1024], servbuf[1024];

    memset(&hints, 0, sizeof(hints));
    hints.ai_family = family;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_flags = AI_CANONNAME;
    error = getaddrinfo(hostname, "http", &hints, &res0);
    if (error) {
        fprintf(stderr, "getaddrinfo failed for %s,family=%d: %s\n",
            hostname, family, gai_strerror(error));
        return;
    }

    for (res = res0; res; res = res->ai_next) {
        error = getnameinfo(res->ai_addr,
                    (socklen_t)res->ai_addrlen,
                    addrbuf, sizeof(addrbuf),
                    NULL, 0, NI_NUMERICHOST);
        if (error == 0)
            error = getnameinfo(res->ai_addr,
                        (socklen_t)res->ai_addrlen,
                        namebuf, sizeof(namebuf),
                        servbuf, sizeof(servbuf), 0);
        if (error != 0) {
            fprintf(stderr, "getnameinfo failed: %s\n",
                gai_strerror(error));
        } else {
            printf("%s(%s/%s)=%s:%s\n", hostname,
                   res->ai_canonname, addrbuf, namebuf, servbuf);
        }
    }

    freeaddrinfo(res0);
}

int
main(int argc, char *argv[]) {
    if (argc < 2)
        exit(1);

    do_gai(AF_INET, argv[1]);
    do_gai(AF_INET6, argv[1]);
    do_gai(AF_UNSPEC, argv[1]);

    return (0);
}