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Allow getting server port with DNS txt record (stk-server-port=)

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This commit is contained in:
Benau 2020-02-06 00:46:38 +08:00
parent 21cf075e41
commit 43cf39bdef
2 changed files with 132 additions and 19 deletions
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9
CMakeLists.txt
View File

@ -159,6 +159,12 @@ endif()
add_subdirectory("${PROJECT_SOURCE_DIR}/lib/bullet")
include_directories("${PROJECT_SOURCE_DIR}/lib/bullet/src")
if(WIN32)
set(LIBRESOLV_LIBRARY)
else()
find_library(LIBRESOLV_LIBRARY NAMES resolv libresolv)
endif()
# Find system ENet library or build it if missing
if((UNIX AND NOT APPLE) AND USE_SYSTEM_ENET AND NOT USE_IPV6)
pkg_check_modules(ENET libenet>=1.3.4)
@ -590,6 +596,7 @@ target_link_libraries(supertuxkart
stkirrlicht
${Angelscript_LIBRARIES}
${CURL_LIBRARIES}
${LIBRESOLV_LIBRARY}
mcpp
)
@ -676,7 +683,7 @@ if(MSVC OR MINGW)
endif()
if(MINGW)
target_link_libraries(supertuxkart -ldxguid -ldinput8)
target_link_libraries(supertuxkart -ldxguid -ldinput8 -ldnsapi)
if (NOT CMAKE_BUILD_TYPE MATCHES Debug)
target_link_libraries(supertuxkart -mwindows)
endif()

142
src/network/protocols/connect_to_server.cpp
View File

@ -41,9 +41,17 @@
#include "utils/translation.hpp"
#ifdef WIN32
# include <windns.h>
# include <ws2tcpip.h>
#ifndef __MINGW32__
# pragma comment(lib, "dnsapi.lib")
#endif
#else
# include <arpa/nameser.h>
# include <arpa/nameser_compat.h>
# include <netdb.h>
# include <netinet/in.h>
# include <resolv.h>
#endif
#include <algorithm>
@ -573,13 +581,94 @@ ENetAddress ConnectToServer::toENetAddress(uint32_t ip, uint16_t port)
// ----------------------------------------------------------------------------
bool ConnectToServer::detectPort()
{
// DNS txt record lookup, we will do stk-server-port server discovery port
// too to get an updated sever address, in case it's differ then the
// A / AAAA record (possible in LAN environment with multiple IPs assigned)
int port_from_dns = 0;
auto get_port = [](const std::string& txt_record)->int
{
const char* match = "stk-server-port=";
size_t len = strlen(match);
auto it = txt_record.find(match);
if (it != std::string::npos && it + len < txt_record.size())
{
const std::string& ss =
txt_record.substr(it + len, txt_record.size());
int result = atoi(ss.c_str());
if (result > 65535)
result = 0;
if (result != 0)
{
Log::info("ConnectToServer",
"Port %d found in DNS txt record %s", result,
txt_record.c_str());
return result;
}
}
return 0;
};
#ifdef WIN32
PDNS_RECORD dns_record = NULL;
DnsQuery(m_server->getName().c_str(), DNS_TYPE_TEXT,
DNS_QUERY_STANDARD, NULL, &dns_record, NULL);
if (dns_record)
{
for (PDNS_RECORD curr = dns_record; curr; curr = curr->pNext)
{
if (curr->wType == DNS_TYPE_TEXT)
{
for (unsigned i = 0; i < curr->Data.TXT.dwStringCount; i++)
{
std::string txt_record = StringUtils::wideToUtf8(
curr->Data.TXT.pStringArray[i]);
port_from_dns = get_port(txt_record);
if (port_from_dns != 0)
break;
}
}
if (port_from_dns != 0)
break;
}
DnsRecordListFree(dns_record, DnsFreeRecordListDeep);
}
#else
unsigned char response[512] = {};
const std::string& utf8name = StringUtils::wideToUtf8(m_server->getName());
int response_len = res_query(utf8name.c_str(), C_IN, T_TXT, response, 512);
if (response_len > 0)
{
ns_msg query;
if (ns_initparse(response, response_len, &query) >= 0)
{
unsigned msg_count = ns_msg_count(query, ns_s_an);
for (unsigned i = 0; i < msg_count; i++)
{
ns_rr rr;
if (ns_parserr(&query, ns_s_an, i, &rr) >= 0)
{
// obtain the record data
const unsigned char* rd = ns_rr_rdata(rr);
// the first byte is the length of the data
size_t length = rd[0];
if (length == 0)
continue;
std::string txt_record((char*)rd + 1, length);
port_from_dns = get_port(txt_record);
if (port_from_dns != 0)
break;
}
}
}
}
#endif
ENetAddress ea;
ea.host = STKHost::HOST_ANY;
ea.port = STKHost::PORT_ANY;
Network* nw = new Network(/*peer_count*/1,
std::unique_ptr<Network> nw(new Network(/*peer_count*/1,
/*channel_limit*/EVENT_CHANNEL_COUNT,
/*max_in_bandwidth*/0, /*max_out_bandwidth*/0, &ea,
true/*change_port_if_bound*/);
true/*change_port_if_bound*/));
BareNetworkString s(std::string("stk-server-port"));
SocketAddress address;
if (m_server->useIPV6Connection())
@ -592,30 +681,47 @@ bool ConnectToServer::detectPort()
const int LEN = 2048;
char buffer[LEN];
int len = nw->receiveRawPacket(buffer, LEN, &sender, 2000);
if (len != 2)
if (len == 2)
{
BareNetworkString server_port(buffer, len);
uint16_t port = server_port.getUInt16();
sender.setPort(port);
// Use the DNS detected port over direct socket one, because only
// one direct socket exists in a host even they have many stk servers
if (port_from_dns != 0)
sender.setPort((uint16_t)port_from_dns);
// We replace the server address with sender with the detected port
// completely, so we can use input like ff02::1 and then get the
// correct local link server address
if (m_server->useIPV6Connection())
m_server->setIPV6Address(sender);
else
m_server->setAddress(sender);
Log::info("ConnectToServer",
"Detected new address %s for server address: %s.",
sender.toString().c_str(), address.toString(false).c_str());
}
else if (port_from_dns != 0)
{
// Use only from dns record
if (m_server->useIPV6Connection())
m_server->getIPV6Address()->setPort(port_from_dns);
else
{
SocketAddress addr = m_server->getAddress();
addr.setPort(port_from_dns);
m_server->setAddress(addr);
}
}
else
{
const core::stringw& n = m_server->getName();
//I18N: Show the failed detect port server name
core::stringw e = _("Failed to detect port number for server %s.", n);
delete nw;
STKHost::get()->setErrorMessage(e);
STKHost::get()->requestShutdown();
m_state = EXITING;
return false;
}
BareNetworkString server_port(buffer, len);
uint16_t port = server_port.getUInt16();
sender.setPort(port);
// We replace the server address with sender with the detected port
// completely, so we can use input like ff02::1 and then get the correct
// local link server address
if (m_server->useIPV6Connection())
m_server->setIPV6Address(sender);
else
m_server->setAddress(sender);
Log::info("ConnectToServer",
"Detected new address %s for server address: %s.",
sender.toString().c_str(), address.toString(false).c_str());
delete nw;
return true;
} // detectPort