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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <LibCore/ArgsParser.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
int main(int argc, char** argv)
{
if (pledge("stdio dns", nullptr) < 0) {
perror("pledge");
return 1;
}
const char* name_or_ip = nullptr;
Core::ArgsParser args_parser;
args_parser.add_positional_argument(name_or_ip, "Domain name or IPv4 address", "name");
args_parser.parse(argc, argv);
// If input looks like an IPv4 address, we should do a reverse lookup.
struct sockaddr_in addr;
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(53);
int rc = inet_pton(AF_INET, name_or_ip, &addr.sin_addr);
if (rc == 1) {
// Okay, let's do a reverse lookup.
auto* hostent = gethostbyaddr(&addr.sin_addr, sizeof(in_addr), AF_INET);
if (!hostent) {
fprintf(stderr, "Reverse lookup failed for '%s'\n", name_or_ip);
return 1;
}
printf("%s is %s\n", name_or_ip, hostent->h_name);
return 0;
}
auto* hostent = gethostbyname(name_or_ip);
if (!hostent) {
fprintf(stderr, "Lookup failed for '%s'\n", name_or_ip);
return 1;
}
char buffer[32];
const char* ip_str = inet_ntop(AF_INET, hostent->h_addr_list[0], buffer, sizeof(buffer));
printf("%s is %s\n", name_or_ip, ip_str);
return 0;
}
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