TeaSpeak-Client/native/dns/utils.cpp
2021-02-06 19:42:29 +01:00

576 lines
22 KiB
C++

#include "./utils.h"
#include "./src/response.h"
#include <map>
#include <vector>
#include <deque>
#include <tuple>
#include <cassert>
#include <mutex>
#include <memory>
#include <iostream>
#include <random>
#include <cstring>
#ifndef WIN32
#include <arpa/inet.h>
#else
#include <Ws2ipdef.h>
#include <ip2string.h>
#endif
using namespace tc::dns;
namespace parser = tc::dns::response::rrparser;
//-------------------------- IP-Resolve
struct CrIpStatus {
std::mutex pending_lock;
uint8_t pending{0};
ServerAddress original{"", 0};
std::tuple<bool, std::string> a{false, "unset"};
std::tuple<bool, std::string> aaaa{false, "unset"};
cr_callback_t callback;
std::function<void(const std::shared_ptr<CrIpStatus>&)> finish_callback;
void one_finished(const std::shared_ptr<CrIpStatus>& _this) {
assert(&*_this == this);
std::lock_guard lock{this->pending_lock};
if(--pending == 0)
this->finish_callback(_this);
}
};
void cr_ip_finish(const std::shared_ptr<CrIpStatus>& status) {
if(std::get<0>(status->a)) {
status->callback(true, ServerAddress{std::get<1>(status->a), status->original.port});
} else if(std::get<0>(status->aaaa)) {
status->callback(true, ServerAddress{std::get<1>(status->aaaa), status->original.port});
} else {
status->callback(false, "failed to resolve an IP for " + status->original.host + ": A{" + std::get<1>(status->a) + "} AAAA{" + std::get<1>(status->aaaa) + "}");
}
}
void tc::dns::cr_ip(Resolver& resolver, const ServerAddress& address, const cr_callback_t& callback) {
auto status = std::make_shared<CrIpStatus>();
status->original = address;
status->finish_callback = cr_ip_finish;
status->callback = callback;
/* general pending so we could finish our method */
status->pending++;
status->pending++;
resolver.resolve_dns(address.host.c_str(), rrtype::A, rrclass::IN, std::chrono::seconds{5}, [status, &resolver](Resolver::ResultState::value state, int code, std::unique_ptr<DNSResponse> data){
if(state != 0) {
status->a = {false, "A query failed. State: " + std::to_string(state) + ", Code: " + std::to_string(code)};
status->one_finished(status);
return;
}
std::string error;
if(!data->parse(error)) {
status->a = {false, "A query failed. State: " + std::to_string(state) + ", Code: " + std::to_string(code)};
status->one_finished(status);
return;
}
for(const auto& answer : data->answers()) {
if(answer->atype() != rrtype::A){
std::cerr << "Received a non A record answer in A query!" << std::endl;
continue;
}
auto data = answer->parse<parser::A>();
if(!data.is_valid())
continue;
status->a = {true, data.address_string()};
status->one_finished(status);
return;
}
status->a = {false, "empty response"};
status->one_finished(status);
});
status->pending++;
resolver.resolve_dns(address.host.c_str(), rrtype::AAAA, rrclass::IN, std::chrono::seconds{5}, [status, &resolver](Resolver::ResultState::value state, int code, std::unique_ptr<DNSResponse> data){
if(state != 0) {
status->aaaa = {false, "AAAA query failed. State: " + std::to_string(state) + ", Code: " + std::to_string(code)};
status->one_finished(status);
return;
}
std::string error;
if(!data->parse(error)) {
status->aaaa = {false, "failed to parse AAAA query reponse: " + error};
status->one_finished(status);
return;
}
for(const auto& answer : data->answers()) {
if(answer->atype() != rrtype::AAAA){
std::cerr << "Received a non AAAA record answer in AAAA query!" << std::endl;
continue;
}
auto data = answer->parse<parser::AAAA>();
if(!data.is_valid())
continue;
status->aaaa = {true, data.address_string()};
status->one_finished(status);
return;
}
status->aaaa = {false, "empty response"};
status->one_finished(status);
return;
});
status->one_finished(status);
}
//-------------------------- SRV-Resolve
static std::random_device srv_rnd_dev;
static std::mt19937 srv_rnd(srv_rnd_dev());
/* connect resolve for TS3 srv records */
void tc::dns::cr_srv(Resolver& resolver, const ServerAddress& address, const cr_callback_t& callback, const std::string& application) {
auto query = application + "." + address.host;
resolver.resolve_dns(query.c_str(), rrtype::SRV, rrclass::IN, std::chrono::seconds{5}, [callback, address, &resolver](Resolver::ResultState::value state, int code, std::unique_ptr<DNSResponse> data){
if(state != 0) {
callback(false, "SRV query failed. State: " + std::to_string(state) + ", Code: " + std::to_string(code));
return;
}
std::string error;
if(!data->parse(error)) {
callback(false, "failed to parse srv query reponse: " + error);
return;
}
struct SrvEntry {
uint16_t weight;
std::string target;
uint16_t port;
};
std::map<uint16_t, std::vector<SrvEntry>> entries{};
auto answers = data->answers();
for(const auto& answer : answers) {
if(answer->atype() != rrtype::SRV) {
std::cerr << "Received a non SRV record answer in SRV query (" << rrtype::name(answer->atype()) << ")!" << std::endl;
continue;
}
auto srv = answer->parse<parser::SRV>();
entries[srv.priority()].push_back({srv.weight(), srv.target_hostname(), srv.target_port()});
}
if(entries.empty()) {
callback(false, "empty response");
return;
}
std::deque<std::tuple<uint16_t, SrvEntry>> results{};
for(auto [priority, pentries] : entries) {
uint32_t count = 0;
for(const auto& entry : pentries) {
#ifdef WIN32
count += max((size_t) entry.weight, 1UL);
#else
count += std::max((size_t) entry.weight, 1UL);
#endif
}
std::uniform_int_distribution<std::mt19937::result_type> dist(0, (uint32_t) (count - 1));
auto index = dist(srv_rnd);
count = 0;
for(const auto& entry : pentries) {
#ifdef WIN32
count += max((size_t) entry.weight, 1UL);
#else
count += std::max((size_t) entry.weight, 1UL);
#endif
if(count > index) {
count = -1;
results.emplace_back(priority, entry);
break;
}
}
}
assert(!results.empty());
std::sort(results.begin(), results.end(), [](const auto& a, const auto& b) { return std::get<0>(a) < std::get<0>(b); });
//TODO: Resolve backup stuff as well
auto target = std::get<1>(*results.begin());
cr_ip(resolver, {
target.target,
target.port == 0 ? address.port : target.port
}, [callback](bool success, auto response) {
if(!success) {
//TODO: Use the backup stuff?
callback(false, "failed to resolve dns pointer: " + std::get<std::string>(response));
return;
}
callback(true, std::get<ServerAddress>(response));
});
});
}
//-------------------------- TSDNS-Resolve
void tc::dns::cr_tsdns(tc::dns::Resolver &resolver, const tc::dns::ServerAddress &address, const tc::dns::cr_callback_t &callback) {
auto root = next_subdomain_level(address.host);
cr_srv(resolver, {root, 0}, [&resolver, callback, address](bool success, auto data){
if(!success) {
callback(false, "failed to resolve tsdns address: " + std::get<std::string>(data));
return;
}
auto tsdns_host = std::get<ServerAddress>(data);
sockaddr_storage tsdns_address{};
memset(&tsdns_address, 0, sizeof(tsdns_address));
auto tsdns_a6 = (sockaddr_in6*) &tsdns_address;
auto tsdns_a4 = (sockaddr_in*) &tsdns_address;
#ifdef WIN32
PCSTR terminator{nullptr};
if(RtlIpv6StringToAddressA(tsdns_host.host.c_str(), &terminator, (in6_addr*) &tsdns_a6->sin6_addr) == 0)
#else
if(inet_pton(AF_INET6, tsdns_host.host.c_str(), &tsdns_a6->sin6_addr) == 1)
#endif
{
tsdns_a6->sin6_family = AF_INET6;
tsdns_a6->sin6_port = htons(tsdns_host.port == 0 ? 41144 : tsdns_host.port);
}
#ifdef WIN32
else if(RtlIpv4StringToAddressA(tsdns_host.host.c_str(), false, &terminator, (in_addr*) &tsdns_a4->sin_addr) == 0)
#else
else if(inet_pton(AF_INET, tsdns_host.host.c_str(), &(tsdns_a4->sin_addr)) == 1)
#endif
{
tsdns_a4->sin_family = AF_INET;
tsdns_a4->sin_port = htons(tsdns_host.port == 0 ? 41144 : tsdns_host.port);
} else {
callback(false, "invalid tsdns host: " + tsdns_host.host);
return;
}
auto query = address.host;
std::transform(query.begin(), query.end(), query.begin(), tolower);
resolver.resolve_tsdns(query.c_str(), tsdns_address, std::chrono::seconds{5}, [callback, query, address](Resolver::ResultState::value error, int detail, const std::string& response) {
if(error == Resolver::ResultState::SUCCESS) {
if(response == "404")
callback(false, "no record found for " + query);
else {
std::string host{response};
std::string port{"$PORT"};
//TODO: Backup IP-Addresses?
if(host.find(',') != -1)
host = std::string{host.begin(), host.begin() + host.find(',')};
auto colon_index = host.rfind(':');
if(colon_index > 0 && (host[colon_index - 1] == ']' || host.find(':') == colon_index)) {
port = host.substr(colon_index + 1);
host = host.substr(0, colon_index);
}
ServerAddress resp{host, 0};
if(port == "$PORT") {
resp.port = address.port;
} else {
try {
resp.port = (uint16_t) stoul(port);
} catch(const std::exception&) {
callback(false, "failed to parse response: " + response + " Failed to parse port: " + port);
return;
}
}
callback(true, resp);
}
} else {
callback(false, "query failed. Code: " + std::to_string(error) + "," + std::to_string(detail) + ": " + response);
}
});
}, "_tsdns._tcp");
}
//-------------------------- Full-Resolve
struct CrStatus {
enum State {
PENDING,
FAILED,
SUCCESS
};
std::recursive_mutex pending_lock; /* do_done could be called recursively because DNS request could answer instant! */
uint8_t pending{0};
bool finished{false};
tc::dns::ServerAddress address;
tc::dns::cr_callback_t callback;
~CrStatus() {
assert(this->pending == 0);
}
void do_done(const std::shared_ptr<CrStatus>& _this) {
std::lock_guard lock{pending_lock};
this->finished |= this->try_answer(_this); //May invokes next DNS query
assert(this->pending > 0);
if(--pending == 0 && !this->finished) { //Order matters we have to decrease pensing!
this->print_status();
this->callback(false, "no results");
this->finished = true;
return;
}
}
typedef std::tuple<bool, std::function<void(const std::shared_ptr<CrStatus>&)>> flagged_executor_t;
flagged_executor_t execute_subsrv_ts;
std::tuple<State, std::string, tc::dns::ServerAddress> subsrv_ts;
flagged_executor_t execute_subsrv_ts3;
std::tuple<State, std::string, tc::dns::ServerAddress> subsrv_ts3;
flagged_executor_t execute_tsdns;
std::tuple<State, std::string, tc::dns::ServerAddress> tsdns;
flagged_executor_t execute_root_tsdns;
std::tuple<State, std::string, tc::dns::ServerAddress> root_tsdns;
flagged_executor_t execute_subdomain;
std::tuple<State, std::string, tc::dns::ServerAddress> subdomain;
//Only after subsrc and tsdns failed
flagged_executor_t execute_rootsrv;
std::tuple<State, std::string, tc::dns::ServerAddress> rootsrv;
//Only after subsrc and tsdns failed
flagged_executor_t execute_rootdomain;
std::tuple<State, std::string, tc::dns::ServerAddress> rootdomain;
#define try_answer_test(element, executor) \
if(std::get<0>(element) == State::SUCCESS) { \
this->call_answer(std::get<2>(element)); \
return true; \
} else if(std::get<0>(element) == State::PENDING) { \
if(!std::get<0>(executor)) { \
std::get<0>(executor) = true; \
if(!!std::get<1>(executor)) { \
std::get<1>(executor)(_this); \
return false; \
} else { \
std::get<1>(element) = "No executor"; \
std::get<0>(element) = State::FAILED; \
} \
} else { \
return false; \
} \
}
bool try_answer(const std::shared_ptr<CrStatus>& _this) {
if(this->finished) {
return true;
}
try_answer_test(this->subsrv_ts, this->execute_subsrv_ts);
try_answer_test(this->subsrv_ts3, this->execute_subsrv_ts3);
try_answer_test(this->tsdns, this->execute_tsdns);
try_answer_test(this->root_tsdns, this->execute_root_tsdns);
try_answer_test(this->subdomain, this->execute_subdomain);
try_answer_test(this->rootsrv, this->execute_rootsrv);
try_answer_test(this->rootdomain, this->execute_rootdomain);
return false;
}
#define answer_log(element, executor) \
if(!std::get<0>(executor)) \
std::cout << #element << ": not executed" << std::endl; \
else if(std::get<0>(element) == State::PENDING) \
std::cout << #element << ": pending" << std::endl; \
else if(std::get<0>(element) == State::FAILED) \
std::cout << #element << ": failed: " << std::get<1>(element) << std::endl; \
else \
std::cout << #element << ": success: " << std::get<2>(element).host << ":" << std::get<2>(element).port << std::endl;
void print_status() {
answer_log(this->subsrv_ts, this->execute_subsrv_ts);
answer_log(this->subsrv_ts3, this->execute_subsrv_ts3);
answer_log(this->tsdns, this->execute_tsdns);
answer_log(this->root_tsdns, this->execute_root_tsdns);
answer_log(this->subdomain, this->execute_subdomain);
answer_log(this->rootsrv, this->execute_rootsrv);
answer_log(this->rootdomain, this->execute_rootdomain);
}
void call_answer(const tc::dns::ServerAddress& data) {
this->print_status();
this->callback(true, data);
}
};
void tc::dns::cr(Resolver& resolver, const tc::dns::ServerAddress& address, const tc::dns::cr_callback_t& callback) {
auto status = std::make_shared<CrStatus>();
status->address = address;
status->callback = callback;
status->pending++;
status->execute_subsrv_ts = {
false,
[&resolver](const std::shared_ptr<CrStatus>& status) {
//std::cout << "Execute subsrc ts" << std::endl;
status->pending++;
tc::dns::cr_srv(resolver, status->address, [status](bool success, auto data) {
if(success) {
status->subsrv_ts = {CrStatus::SUCCESS, "", std::get<ServerAddress>(data)};
} else {
status->subsrv_ts = {CrStatus::FAILED, std::get<std::string>(data), {}};
}
status->do_done(status);
}, "_ts._udp");
}
};
/* execute */
std::get<0>(status->execute_subsrv_ts) = true;
status->execute_subsrv_ts3 = {
false,
[&resolver](const std::shared_ptr<CrStatus>& status) {
//std::cout << "Execute subsrc ts3" << std::endl;
status->pending++;
tc::dns::cr_srv(resolver, status->address, [status](bool success, auto data) {
if(success) {
status->subsrv_ts3 = {CrStatus::SUCCESS, "", std::get<ServerAddress>(data)};
} else {
status->subsrv_ts3 = {CrStatus::FAILED, std::get<std::string>(data), {}};
}
status->do_done(status);
}, "_ts3._udp");
}
};
/* execute */
std::get<0>(status->execute_subsrv_ts3) = true;
status->execute_subdomain = {
false,
[&resolver](const std::shared_ptr<CrStatus>& status) {
//std::cout << "Execute subdomain" << std::endl;
status->pending++;
tc::dns::cr_ip(resolver, status->address, [status](bool success, auto data) {
if(success) {
status->subdomain = {CrStatus::SUCCESS, "", std::get<ServerAddress>(data)};
} else {
status->subdomain = {CrStatus::FAILED, std::get<std::string>(data), {}};
}
status->do_done(status);
});
}
};
/* execute */
//Will be autoamticall be executed after the SRV stuff
//std::get<0>(status->execute_subdomain) = true;
status->execute_tsdns = {
false,
[&resolver](const std::shared_ptr<CrStatus>& status) {
//std::cout << "Execute tsdns" << std::endl;
status->pending++;
tc::dns::cr_tsdns(resolver, status->address, [status](bool success, auto data) {
if(success) {
status->tsdns = {CrStatus::SUCCESS, "", std::get<ServerAddress>(data)};
} else {
status->tsdns = {CrStatus::FAILED, std::get<std::string>(data), {}};
}
status->do_done(status);
});
}
};
/* execute */
//Execute the TSDNS request right at the beginning because it could hang sometimes
std::get<0>(status->execute_tsdns) = true;
auto root_domain = tc::dns::next_subdomain_level(status->address.host);
if(root_domain != status->address.host) {
status->execute_root_tsdns = {
false,
[&resolver, root_domain](const std::shared_ptr<CrStatus>& status) {
//std::cout << "Execute tsdns" << std::endl;
status->pending++;
tc::dns::cr_tsdns(resolver, {
root_domain,
status->address.port
}, [status](bool success, auto data) {
if(success) {
status->tsdns = {CrStatus::SUCCESS, "", std::get<ServerAddress>(data)};
} else {
status->tsdns = {CrStatus::FAILED, std::get<std::string>(data), {}};
}
status->do_done(status);
});
}
};
status->execute_rootsrv = {
false,
[&resolver](const std::shared_ptr<CrStatus>& status) {
//std::cout << "Execute root srv" << std::endl;
status->pending++;
tc::dns::cr_srv(resolver, {
tc::dns::next_subdomain_level(status->address.host),
status->address.port
}, [status](bool success, auto data) {
if(success) {
status->rootsrv = {CrStatus::SUCCESS, "", std::get<ServerAddress>(data)};
} else {
status->rootsrv = {CrStatus::FAILED, std::get<std::string>(data), {}};
}
status->do_done(status);
}, "_ts3._udp");
}
};
status->execute_rootdomain = {
false,
[&resolver](const std::shared_ptr<CrStatus>& status) {
//std::cout << "Execute root domain" << std::endl;
status->pending++;
tc::dns::cr_ip(resolver,{
tc::dns::next_subdomain_level(status->address.host),
status->address.port
}, [status](bool success, auto data) {
if(success) {
status->rootdomain = {CrStatus::SUCCESS, "", std::get<ServerAddress>(data)};
} else {
status->rootdomain = {CrStatus::FAILED, std::get<std::string>(data), {}};
}
status->do_done(status);
});
}
};
}
/* Only execute after every executor has been registered! */
std::get<1>(status->execute_subsrv_ts)(status);
std::get<1>(status->execute_subsrv_ts3)(status);
//std::get<1>(status->execute_subdomain)(status);
std::get<1>(status->execute_tsdns)(status);
status->do_done(status);
}