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@ r25814:efd9cb732234
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Location: cpp/openttd-patchpack/source/src/network/core/tcp_connect.cpp
r25814:efd9cb732234
13.3 KiB
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Change: groundwork to allow ServerAddress to use invite codes
Normally TCPConnecter will do a DNS resolving of the connection_string
and connect to it. But for SERVER_ADDRESS_INVITE_CODE this is different:
the Game Coordinator does the "resolving".
This means we need to allow TCPConnecter to not setup a connection
and allow it to be told when a connection has been setup by an external
(to TCPConnecter) part of the code. We do this by telling the (active)
socket for the connection.
This means the rest of the code doesn't need to know the TCPConnecter
is not doing a simple resolve+connect. The rest of the code only
cares the connection is established; not how it was established.
Normally TCPConnecter will do a DNS resolving of the connection_string
and connect to it. But for SERVER_ADDRESS_INVITE_CODE this is different:
the Game Coordinator does the "resolving".
This means we need to allow TCPConnecter to not setup a connection
and allow it to be told when a connection has been setup by an external
(to TCPConnecter) part of the code. We do this by telling the (active)
socket for the connection.
This means the rest of the code doesn't need to know the TCPConnecter
is not doing a simple resolve+connect. The rest of the code only
cares the connection is established; not how it was established.
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* This file is part of OpenTTD.
* OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
* OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file tcp_connect.cpp Basic functions to create connections without blocking.
*/
#include "../../stdafx.h"
#include "../../thread.h"
#include "tcp.h"
#include "../network_internal.h"
#include <deque>
#include "../../safeguards.h"
/** List of connections that are currently being created */
static std::vector<TCPConnecter *> _tcp_connecters;
/**
* Create a new connecter for the given address
* @param connection_string the address to connect to
*/
TCPConnecter::TCPConnecter(const std::string &connection_string, uint16 default_port)
{
this->connection_string = NormalizeConnectionString(connection_string, default_port);
_tcp_connecters.push_back(this);
}
/**
* Create a new connecter for the server.
* @param connection_string The address to connect to.
* @param default_port If not indicated in connection_string, what port to use.
*/
TCPServerConnecter::TCPServerConnecter(const std::string &connection_string, uint16 default_port) :
server_address(ServerAddress::Parse(connection_string, default_port))
{
switch (this->server_address.type) {
case SERVER_ADDRESS_DIRECT:
this->connection_string = this->server_address.connection_string;
break;
case SERVER_ADDRESS_INVITE_CODE:
this->status = Status::CONNECTING;
// TODO -- The next commit will add this functionality.
break;
default:
NOT_REACHED();
}
_tcp_connecters.push_back(this);
}
TCPConnecter::~TCPConnecter()
{
if (this->resolve_thread.joinable()) {
this->resolve_thread.join();
}
for (const auto &socket : this->sockets) {
closesocket(socket);
}
this->sockets.clear();
this->sock_to_address.clear();
if (this->ai != nullptr) freeaddrinfo(this->ai);
}
/**
* Kill this connecter.
* It will abort as soon as it can and not call any of the callbacks.
*/
void TCPConnecter::Kill()
{
/* Delay the removing of the socket till the next CheckActivity(). */
this->killed = true;
}
/**
* Start a connection to the indicated address.
* @param address The address to connection to.
*/
void TCPConnecter::Connect(addrinfo *address)
{
SOCKET sock = socket(address->ai_family, address->ai_socktype, address->ai_protocol);
if (sock == INVALID_SOCKET) {
Debug(net, 0, "Could not create {} {} socket: {}", NetworkAddress::SocketTypeAsString(address->ai_socktype), NetworkAddress::AddressFamilyAsString(address->ai_family), NetworkError::GetLast().AsString());
return;
}
if (!SetNoDelay(sock)) {
Debug(net, 1, "Setting TCP_NODELAY failed: {}", NetworkError::GetLast().AsString());
}
if (!SetNonBlocking(sock)) {
Debug(net, 0, "Setting non-blocking mode failed: {}", NetworkError::GetLast().AsString());
}
NetworkAddress network_address = NetworkAddress(address->ai_addr, (int)address->ai_addrlen);
Debug(net, 5, "Attempting to connect to {}", network_address.GetAddressAsString());
int err = connect(sock, address->ai_addr, (int)address->ai_addrlen);
if (err != 0 && !NetworkError::GetLast().IsConnectInProgress()) {
closesocket(sock);
Debug(net, 1, "Could not connect to {}: {}", network_address.GetAddressAsString(), NetworkError::GetLast().AsString());
return;
}
this->sock_to_address[sock] = network_address;
this->sockets.push_back(sock);
}
/**
* Start the connect() for the next address in the list.
* @return True iff a new connect() is attempted.
*/
bool TCPConnecter::TryNextAddress()
{
if (this->current_address >= this->addresses.size()) return false;
this->last_attempt = std::chrono::steady_clock::now();
this->Connect(this->addresses[this->current_address++]);
return true;
}
/**
* Callback when resolving is done.
* @param ai A linked-list of address information.
*/
void TCPConnecter::OnResolved(addrinfo *ai)
{
std::deque<addrinfo *> addresses_ipv4, addresses_ipv6;
/* Apply "Happy Eyeballs" if it is likely IPv6 is functional. */
/* Detect if IPv6 is likely to succeed or not. */
bool seen_ipv6 = false;
bool resort = true;
for (addrinfo *runp = ai; runp != nullptr; runp = runp->ai_next) {
if (runp->ai_family == AF_INET6) {
seen_ipv6 = true;
} else if (!seen_ipv6) {
/* We see an IPv4 before an IPv6; this most likely means there is
* no IPv6 available on the system, so keep the order of this
* list. */
resort = false;
break;
}
}
/* Convert the addrinfo into NetworkAddresses. */
for (addrinfo *runp = ai; runp != nullptr; runp = runp->ai_next) {
if (resort) {
if (runp->ai_family == AF_INET6) {
addresses_ipv6.emplace_back(runp);
} else {
addresses_ipv4.emplace_back(runp);
}
} else {
this->addresses.emplace_back(runp);
}
}
/* If we want to resort, make the list like IPv6 / IPv4 / IPv6 / IPv4 / ..
* for how ever many (round-robin) DNS entries we have. */
if (resort) {
while (!addresses_ipv4.empty() || !addresses_ipv6.empty()) {
if (!addresses_ipv6.empty()) {
this->addresses.push_back(addresses_ipv6.front());
addresses_ipv6.pop_front();
}
if (!addresses_ipv4.empty()) {
this->addresses.push_back(addresses_ipv4.front());
addresses_ipv4.pop_front();
}
}
}
if (_debug_net_level >= 6) {
Debug(net, 6, "{} resolved in:", this->connection_string);
for (const auto &address : this->addresses) {
Debug(net, 6, "- {}", NetworkAddress(address->ai_addr, (int)address->ai_addrlen).GetAddressAsString());
}
}
this->current_address = 0;
}
/**
* Start resolving the hostname.
*
* This function must change "status" to either Status::FAILURE
* or Status::CONNECTING before returning.
*/
void TCPConnecter::Resolve()
{
/* Port is already guaranteed part of the connection_string. */
NetworkAddress address = ParseConnectionString(this->connection_string, 0);
addrinfo hints;
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_flags = AI_ADDRCONFIG;
hints.ai_socktype = SOCK_STREAM;
char port_name[6];
seprintf(port_name, lastof(port_name), "%u", address.GetPort());
static bool getaddrinfo_timeout_error_shown = false;
auto start = std::chrono::steady_clock::now();
addrinfo *ai;
int error = getaddrinfo(address.GetHostname().c_str(), port_name, &hints, &ai);
auto end = std::chrono::steady_clock::now();
auto duration = std::chrono::duration_cast<std::chrono::seconds>(end - start);
if (!getaddrinfo_timeout_error_shown && duration >= std::chrono::seconds(5)) {
Debug(net, 0, "getaddrinfo() for address \"{}\" took {} seconds", this->connection_string, duration.count());
Debug(net, 0, " This is likely an issue in the DNS name resolver's configuration causing it to time out");
getaddrinfo_timeout_error_shown = true;
}
if (error != 0) {
Debug(net, 0, "Failed to resolve DNS for {}", this->connection_string);
this->status = Status::FAILURE;
return;
}
this->ai = ai;
this->OnResolved(ai);
this->status = Status::CONNECTING;
}
/**
* Thunk to start Resolve() on the right instance.
*/
/* static */ void TCPConnecter::ResolveThunk(TCPConnecter *connecter)
{
connecter->Resolve();
}
/**
* Check if there was activity for this connecter.
* @return True iff the TCPConnecter is done and can be cleaned up.
*/
bool TCPConnecter::CheckActivity()
{
if (this->killed) return true;
switch (this->status) {
case Status::INIT:
/* Start the thread delayed, so the vtable is loaded. This allows classes
* to overload functions used by Resolve() (in case threading is disabled). */
if (StartNewThread(&this->resolve_thread, "ottd:resolve", &TCPConnecter::ResolveThunk, this)) {
this->status = Status::RESOLVING;
return false;
}
/* No threads, do a blocking resolve. */
this->Resolve();
/* Continue as we are either failed or can start the first
* connection. The rest of this function handles exactly that. */
break;
case Status::RESOLVING:
/* Wait till Resolve() comes back with an answer (in case it runs threaded). */
return false;
case Status::FAILURE:
/* Ensure the OnFailure() is called from the game-thread instead of the
* resolve-thread, as otherwise we can get into some threading issues. */
this->OnFailure();
return true;
case Status::CONNECTING:
case Status::CONNECTED:
break;
}
/* If there are no attempts pending, connect to the next. */
if (this->sockets.empty()) {
if (!this->TryNextAddress()) {
/* There were no more addresses to try, so we failed. */
this->OnFailure();
return true;
}
return false;
}
fd_set write_fd;
FD_ZERO(&write_fd);
for (const auto &socket : this->sockets) {
FD_SET(socket, &write_fd);
}
timeval tv;
tv.tv_usec = 0;
tv.tv_sec = 0;
int n = select(FD_SETSIZE, nullptr, &write_fd, nullptr, &tv);
/* select() failed; hopefully next try it doesn't. */
if (n < 0) {
/* select() normally never fails; so hopefully it works next try! */
Debug(net, 1, "select() failed: {}", NetworkError::GetLast().AsString());
return false;
}
/* No socket updates. */
if (n == 0) {
/* Wait 250ms between attempting another address. */
if (std::chrono::steady_clock::now() < this->last_attempt + std::chrono::milliseconds(250)) return false;
/* Try the next address in the list. */
if (this->TryNextAddress()) return false;
/* Wait up to 3 seconds since the last connection we started. */
if (std::chrono::steady_clock::now() < this->last_attempt + std::chrono::milliseconds(3000)) return false;
/* More than 3 seconds no socket reported activity, and there are no
* more address to try. Timeout the attempt. */
Debug(net, 0, "Timeout while connecting to {}", this->connection_string);
for (const auto &socket : this->sockets) {
closesocket(socket);
}
this->sockets.clear();
this->sock_to_address.clear();
this->OnFailure();
return true;
}
/* Check for errors on any of the sockets. */
for (auto it = this->sockets.begin(); it != this->sockets.end(); /* nothing */) {
NetworkError socket_error = GetSocketError(*it);
if (socket_error.HasError()) {
Debug(net, 1, "Could not connect to {}: {}", this->sock_to_address[*it].GetAddressAsString(), socket_error.AsString());
closesocket(*it);
this->sock_to_address.erase(*it);
it = this->sockets.erase(it);
} else {
it++;
}
}
/* In case all sockets had an error, queue a new one. */
if (this->sockets.empty()) {
if (!this->TryNextAddress()) {
/* There were no more addresses to try, so we failed. */
this->OnFailure();
return true;
}
return false;
}
/* At least one socket is connected. The first one that does is the one
* we will be using, and we close all other sockets. */
SOCKET connected_socket = INVALID_SOCKET;
for (auto it = this->sockets.begin(); it != this->sockets.end(); /* nothing */) {
if (connected_socket == INVALID_SOCKET && FD_ISSET(*it, &write_fd)) {
connected_socket = *it;
} else {
closesocket(*it);
}
this->sock_to_address.erase(*it);
it = this->sockets.erase(it);
}
assert(connected_socket != INVALID_SOCKET);
Debug(net, 3, "Connected to {}", this->connection_string);
if (_debug_net_level >= 5) {
Debug(net, 5, "- using {}", NetworkAddress::GetPeerName(connected_socket));
}
this->OnConnect(connected_socket);
this->status = Status::CONNECTED;
return true;
}
/**
* Check if there was activity for this connecter.
* @return True iff the TCPConnecter is done and can be cleaned up.
*/
bool TCPServerConnecter::CheckActivity()
{
if (this->killed) return true;
switch (this->server_address.type) {
case SERVER_ADDRESS_DIRECT:
return TCPConnecter::CheckActivity();
case SERVER_ADDRESS_INVITE_CODE:
/* Check if a result has come in. */
switch (this->status) {
case Status::FAILURE:
this->OnFailure();
return true;
case Status::CONNECTED:
this->OnConnect(this->socket);
return true;
default:
break;
}
return false;
default:
NOT_REACHED();
}
}
/**
* The connection was successfully established.
* This socket is fully setup and ready to send/recv game protocol packets.
* @param sock The socket of the established connection.
*/
void TCPServerConnecter::SetConnected(SOCKET sock)
{
this->socket = sock;
this->status = Status::CONNECTED;
}
/**
* The connection couldn't be established.
*/
void TCPServerConnecter::SetFailure()
{
this->status = Status::FAILURE;
}
/**
* Check whether we need to call the callback, i.e. whether we
* have connected or aborted and call the appropriate callback
* for that. It's done this way to ease on the locking that
* would otherwise be needed everywhere.
*/
/* static */ void TCPConnecter::CheckCallbacks()
{
for (auto iter = _tcp_connecters.begin(); iter < _tcp_connecters.end(); /* nothing */) {
TCPConnecter *cur = *iter;
if (cur->CheckActivity()) {
iter = _tcp_connecters.erase(iter);
delete cur;
} else {
iter++;
}
}
}
/** Kill all connection attempts. */
/* static */ void TCPConnecter::KillAll()
{
for (auto iter = _tcp_connecters.begin(); iter < _tcp_connecters.end(); /* nothing */) {
TCPConnecter *cur = *iter;
iter = _tcp_connecters.erase(iter);
delete cur;
}
}
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