blob: 7d3846f0d0a3f284483799365ec7bc967ea55795 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
|
/*
* Copyright (c) 2021, Sergey Bugaev <bugaevc@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "DNSServer.h"
#include "DNSPacket.h"
#include "LookupServer.h"
#include <AK/IPv4Address.h>
namespace LookupServer {
DNSServer::DNSServer(Object* parent)
: Core::UDPServer(parent)
{
bind(IPv4Address(), 53);
on_ready_to_receive = [this]() {
auto result = handle_client();
if (result.is_error()) {
dbgln("DNSServer: Failed to handle client: {}", result.error());
}
};
}
ErrorOr<void> DNSServer::handle_client()
{
sockaddr_in client_address;
auto buffer = receive(1024, client_address);
auto optional_request = DNSPacket::from_raw_packet(buffer.data(), buffer.size());
if (!optional_request.has_value()) {
dbgln("Got an invalid DNS packet");
return {};
}
auto& request = optional_request.value();
if (!request.is_query()) {
dbgln("It's not a request");
return {};
}
LookupServer& lookup_server = LookupServer::the();
DNSPacket response;
response.set_is_response();
response.set_id(request.id());
for (auto& question : request.questions()) {
if (question.class_code() != DNSRecordClass::IN)
continue;
response.add_question(question);
auto answers = TRY(lookup_server.lookup(question.name(), question.record_type()));
for (auto& answer : answers) {
response.add_answer(answer);
}
}
if (response.answer_count() == 0)
response.set_code(DNSPacket::Code::NXDOMAIN);
else
response.set_code(DNSPacket::Code::NOERROR);
buffer = response.to_byte_buffer();
TRY(send(buffer, client_address));
return {};
}
}
|
