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LookupServer: Make lookup() return DNSAnswer's instead of strings

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This way, we propagate proper TTL. None of the callers currently care, though.
This commit is contained in:
Sergey Bugaev 2021-02-14 16:57:41 +03:00 • committed by Andreas Kling
parent 3fba6bfb5e
commit 19cfed329e
3 changed files with 40 additions and 23 deletions
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14
Userland/Services/LookupServer/ClientConnection.cpp
View file

@ -50,9 +50,13 @@ void ClientConnection::die()
OwnPtr<Messages::LookupServer::LookupNameResponse> ClientConnection::handle(const Messages::LookupServer::LookupName& message)
{
auto addresses = LookupServer::the().lookup(message.name(), T_A);
if (addresses.is_empty())
auto answers = LookupServer::the().lookup(message.name(), T_A);
if (answers.is_empty())
return make<Messages::LookupServer::LookupNameResponse>(1, Vector<String>());
Vector<String> addresses;
for (auto& answer : answers) {
addresses.append(answer.record_data());
}
return make<Messages::LookupServer::LookupNameResponse>(0, move(addresses));
}
@ -66,9 +70,9 @@ OwnPtr<Messages::LookupServer::LookupAddressResponse> ClientConnection::handle(c
address[2],
address[1],
address[0]);
auto hosts = LookupServer::the().lookup(name, T_PTR);
if (hosts.is_empty())
auto answers = LookupServer::the().lookup(name, T_PTR);
if (answers.is_empty())
return make<Messages::LookupServer::LookupAddressResponse>(1, String());
return make<Messages::LookupServer::LookupAddressResponse>(0, hosts[0]);
return make<Messages::LookupServer::LookupAddressResponse>(0, answers[0].record_data());
}
}

45
Userland/Services/LookupServer/LookupServer.cpp
View file

@ -126,22 +126,32 @@ void LookupServer::load_etc_hosts()
}
}
Vector<String> LookupServer::lookup(const DNSName& name, unsigned short record_type)
Vector<DNSAnswer> LookupServer::lookup(const DNSName& name, unsigned short record_type)
{
#if LOOKUPSERVER_DEBUG
dbgln("Got request for '{}'", name.as_string());
#endif
Vector<String> responses;
Vector<DNSAnswer> answers;
auto add_answer = [&](const DNSAnswer& answer) {
DNSAnswer answer_with_original_case {
name,
answer.type(),
answer.class_code(),
answer.ttl(),
answer.record_data()
};
answers.append(answer_with_original_case);
};
// First, try local data.
if (auto local_answers = m_etc_hosts.get(name); local_answers.has_value()) {
for (auto& answer : local_answers.value()) {
if (answer.type() == record_type)
responses.append(answer.name().as_string());
add_answer(answer);
}
if (!responses.is_empty())
return responses;
if (!answers.is_empty())
return answers;
}
// Second, try our cache.
@ -152,11 +162,11 @@ Vector<String> LookupServer::lookup(const DNSName& name, unsigned short record_t
#if LOOKUPSERVER_DEBUG
dbgln("Cache hit: {} -> {}", name.as_string(), answer.record_data());
#endif
responses.append(answer.record_data());
add_answer(answer);
}
}
if (!responses.is_empty())
return responses;
if (!answers.is_empty())
return answers;
}
// Third, ask the upstream nameservers.
@ -166,12 +176,15 @@ Vector<String> LookupServer::lookup(const DNSName& name, unsigned short record_t
#endif
bool did_get_response = false;
int retries = 3;
Vector<DNSAnswer> upstream_answers;
do {
responses = lookup(name, nameserver, did_get_response, record_type);
upstream_answers = lookup(name, nameserver, did_get_response, record_type);
if (did_get_response)
break;
} while (--retries);
if (!responses.is_empty()) {
if (!upstream_answers.is_empty()) {
for (auto& answer : upstream_answers)
add_answer(answer);
break;
} else {
if (!did_get_response)
@ -180,15 +193,15 @@ Vector<String> LookupServer::lookup(const DNSName& name, unsigned short record_t
dbgln("Received response from '{}' but no result(s), trying next nameserver", nameserver);
}
}
if (responses.is_empty()) {
if (answers.is_empty()) {
fprintf(stderr, "LookupServer: Tried all nameservers but never got a response :(\n");
return {};
}
return move(responses);
return move(answers);
}
Vector<String> LookupServer::lookup(const DNSName& name, const String& nameserver, bool& did_get_response, unsigned short record_type, ShouldRandomizeCase should_randomize_case)
Vector<DNSAnswer> LookupServer::lookup(const DNSName& name, const String& nameserver, bool& did_get_response, unsigned short record_type, ShouldRandomizeCase should_randomize_case)
{
DNSPacket request;
request.set_is_query();
@ -270,15 +283,15 @@ Vector<String> LookupServer::lookup(const DNSName& name, const String& nameserve
return {};
}
Vector<String, 8> responses;
Vector<DNSAnswer, 8> answers;
for (auto& answer : response.answers()) {
put_in_cache(answer);
if (answer.type() != record_type)
continue;
responses.append(answer.record_data());
answers.append(answer);
}
return responses;
return move(answers);
}
void LookupServer::put_in_cache(const DNSAnswer& answer)

4
Userland/Services/LookupServer/LookupServer.h
View file

@ -39,7 +39,7 @@ class LookupServer final : public Core::Object {
public:
static LookupServer& the();
Vector<String> lookup(const DNSName& name, unsigned short record_type);
Vector<DNSAnswer> lookup(const DNSName& name, unsigned short record_type);
private:
LookupServer();
@ -47,7 +47,7 @@ private:
void load_etc_hosts();
void put_in_cache(const DNSAnswer&);
Vector<String> lookup(const DNSName& hostname, const String& nameserver, bool& did_get_response, unsigned short record_type, ShouldRandomizeCase = ShouldRandomizeCase::Yes);
Vector<DNSAnswer> lookup(const DNSName& hostname, const String& nameserver, bool& did_get_response, unsigned short record_type, ShouldRandomizeCase = ShouldRandomizeCase::Yes);
RefPtr<Core::LocalServer> m_local_server;