dolphin/Source/Core/Common/TraversalServer.cpp
Lioncache affe928987 Common/TraversalServer: Make use of fmt more
We can convert printf and fprintf over to the use of fmt as well,
given that we've converted the sprintf calls over.
2023-12-18 13:08:57 -05:00

531 lines
13 KiB
C++

// SPDX-License-Identifier: CC0-1.0
// The central server implementation.
#include <arpa/inet.h>
#include <cerrno>
#include <chrono>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fcntl.h>
#include <netinet/in.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <tuple>
#include <unistd.h>
#include <unordered_map>
#include <utility>
#include <vector>
#include <fmt/format.h>
#ifdef HAVE_LIBSYSTEMD
#include <systemd/sd-daemon.h>
#endif
#include "Common/Random.h"
#include "Common/TraversalProto.h"
#define DEBUG 0
#define NUMBER_OF_TRIES 5
#define PORT 6262
#define PORT_ALT 6226
static u64 currentTime;
struct OutgoingPacketInfo
{
Common::TraversalPacket packet;
Common::TraversalRequestId misc;
bool fromAlt;
sockaddr_in6 dest;
int tries;
u64 sendTime;
};
template <typename T>
struct EvictEntry
{
u64 updateTime;
T value;
};
template <typename V>
struct EvictFindResult
{
bool found;
V* value;
};
template <typename K, typename V>
EvictFindResult<V> EvictFind(std::unordered_map<K, EvictEntry<V>>& map, const K& key,
bool refresh = false)
{
retry:
const u64 expiryTime = 30 * 1000000; // 30s
EvictFindResult<V> result;
if (map.bucket_count())
{
auto bucket = map.bucket(key);
auto it = map.begin(bucket);
for (; it != map.end(bucket); ++it)
{
if (currentTime - it->second.updateTime > expiryTime)
{
map.erase(it->first);
goto retry;
}
if (it->first == key)
{
if (refresh)
it->second.updateTime = currentTime;
result.found = true;
result.value = &it->second.value;
return result;
}
}
}
#if DEBUG
fmt::print("failed to find key '");
for (size_t i = 0; i < sizeof(key); i++)
{
fmt::print("{:02x}", ((u8*)&key)[i]);
}
fmt::print("'\n");
#endif
result.found = false;
return result;
}
template <typename K, typename V>
V* EvictSet(std::unordered_map<K, EvictEntry<V>>& map, const K& key)
{
// can't use a local_iterator to emplace...
auto& result = map[key];
result.updateTime = currentTime;
return &result.value;
}
namespace std
{
template <>
struct hash<Common::TraversalHostId>
{
size_t operator()(const Common::TraversalHostId& id) const noexcept
{
auto p = (u32*)id.data();
return p[0] ^ ((p[1] << 13) | (p[1] >> 19));
}
};
} // namespace std
using ConnectedClients =
std::unordered_map<Common::TraversalHostId, EvictEntry<Common::TraversalInetAddress>>;
using OutgoingPackets = std::unordered_map<Common::TraversalRequestId, OutgoingPacketInfo>;
static int sock;
static int sockAlt;
static OutgoingPackets outgoingPackets;
static ConnectedClients connectedClients;
static Common::TraversalInetAddress MakeInetAddress(const sockaddr_in6& addr)
{
if (addr.sin6_family != AF_INET6)
{
fmt::print(stderr, "bad sockaddr_in6\n");
exit(1);
}
u32* words = (u32*)addr.sin6_addr.s6_addr;
Common::TraversalInetAddress result = {};
if (words[0] == 0 && words[1] == 0 && words[2] == 0xffff0000)
{
result.isIPV6 = false;
result.address[0] = words[3];
}
else
{
result.isIPV6 = true;
memcpy(result.address, words, sizeof(result.address));
}
result.port = addr.sin6_port;
return result;
}
static sockaddr_in6 MakeSinAddr(const Common::TraversalInetAddress& addr)
{
sockaddr_in6 result;
#ifdef SIN6_LEN
result.sin6_len = sizeof(result);
#endif
result.sin6_family = AF_INET6;
result.sin6_port = addr.port;
result.sin6_flowinfo = 0;
if (addr.isIPV6)
{
memcpy(&result.sin6_addr, addr.address, 16);
}
else
{
u32* words = (u32*)result.sin6_addr.s6_addr;
words[0] = 0;
words[1] = 0;
words[2] = 0xffff0000;
words[3] = addr.address[0];
}
result.sin6_scope_id = 0;
return result;
}
static void GetRandomHostId(Common::TraversalHostId* hostId)
{
char buf[9]{};
const u32 num = Common::Random::GenerateValue<u32>();
fmt::format_to_n(buf, sizeof(buf) - 1, "{:08x}", num);
memcpy(hostId->data(), buf, 8);
}
static const char* SenderName(sockaddr_in6* addr)
{
static char buf[INET6_ADDRSTRLEN + 10]{};
inet_ntop(PF_INET6, &addr->sin6_addr, buf, sizeof(buf));
fmt::format_to(buf + strlen(buf), ":{}", ntohs(addr->sin6_port));
return buf;
}
static void TrySend(const void* buffer, size_t size, sockaddr_in6* addr, bool fromAlt)
{
#if DEBUG
const auto* packet = static_cast<const Common::TraversalPacket*>(buffer);
fmt::print("{}-> {} {} {}\n", fromAlt ? "alt " : "", static_cast<int>(packet->type),
static_cast<long long>(packet->requestId), SenderName(addr));
#endif
if ((size_t)sendto(fromAlt ? sockAlt : sock, buffer, size, 0, (sockaddr*)addr, sizeof(*addr)) !=
size)
{
perror("sendto");
}
}
static Common::TraversalPacket* AllocPacket(const sockaddr_in6& dest, bool fromAlt,
Common::TraversalRequestId misc = 0)
{
Common::TraversalRequestId requestId{};
Common::Random::Generate(&requestId, sizeof(requestId));
OutgoingPacketInfo* info = &outgoingPackets[requestId];
info->fromAlt = fromAlt;
info->dest = dest;
info->misc = misc;
info->tries = 0;
info->sendTime = currentTime;
Common::TraversalPacket* result = &info->packet;
memset(result, 0, sizeof(*result));
result->requestId = requestId;
return result;
}
static void SendPacket(OutgoingPacketInfo* info)
{
info->tries++;
info->sendTime = currentTime;
TrySend(&info->packet, sizeof(info->packet), &info->dest, info->fromAlt);
}
static void ResendPackets()
{
std::vector<std::tuple<Common::TraversalInetAddress, bool, Common::TraversalRequestId>>
todoFailures;
todoFailures.clear();
for (auto it = outgoingPackets.begin(); it != outgoingPackets.end();)
{
OutgoingPacketInfo* info = &it->second;
if (currentTime - info->sendTime >= (u64)(300000 * info->tries))
{
if (info->tries >= NUMBER_OF_TRIES)
{
if (info->packet.type == Common::TraversalPacketType::PleaseSendPacket)
{
todoFailures.push_back(
std::make_tuple(info->packet.pleaseSendPacket.address, info->fromAlt, info->misc));
}
it = outgoingPackets.erase(it);
continue;
}
else
{
SendPacket(info);
}
}
++it;
}
for (const auto& p : todoFailures)
{
Common::TraversalPacket* fail = AllocPacket(MakeSinAddr(std::get<0>(p)), std::get<1>(p));
fail->type = Common::TraversalPacketType::ConnectFailed;
fail->connectFailed.requestId = std::get<2>(p);
fail->connectFailed.reason = Common::TraversalConnectFailedReason::ClientDidntRespond;
}
}
static void HandlePacket(Common::TraversalPacket* packet, sockaddr_in6* addr, bool toAlt)
{
#if DEBUG
fmt::print("<- {} {} {}\n", static_cast<int>(packet->type),
static_cast<long long>(packet->requestId), SenderName(addr));
#endif
bool packetOk = true;
switch (packet->type)
{
case Common::TraversalPacketType::Ack:
{
auto it = outgoingPackets.find(packet->requestId);
if (it == outgoingPackets.end())
break;
OutgoingPacketInfo* info = &it->second;
if (info->packet.type == Common::TraversalPacketType::PleaseSendPacket)
{
auto* ready = AllocPacket(MakeSinAddr(info->packet.pleaseSendPacket.address), toAlt);
if (packet->ack.ok)
{
ready->type = Common::TraversalPacketType::ConnectReady;
ready->connectReady.requestId = info->misc;
ready->connectReady.address = MakeInetAddress(info->dest);
}
else
{
ready->type = Common::TraversalPacketType::ConnectFailed;
ready->connectFailed.requestId = info->misc;
ready->connectFailed.reason = Common::TraversalConnectFailedReason::ClientFailure;
}
}
outgoingPackets.erase(it);
break;
}
case Common::TraversalPacketType::Ping:
{
auto r = EvictFind(connectedClients, packet->ping.hostId, true);
packetOk = r.found;
break;
}
case Common::TraversalPacketType::HelloFromClient:
{
u8 ok = packet->helloFromClient.protoVersion <= Common::TraversalProtoVersion;
Common::TraversalPacket* reply = AllocPacket(*addr, toAlt);
reply->type = Common::TraversalPacketType::HelloFromServer;
reply->helloFromServer.ok = ok;
if (ok)
{
Common::TraversalHostId hostId{};
Common::TraversalInetAddress* iaddr{};
// not that there is any significant change of
// duplication, but...
while (true)
{
GetRandomHostId(&hostId);
auto r = EvictFind(connectedClients, hostId);
if (!r.found)
{
iaddr = EvictSet(connectedClients, hostId);
break;
}
}
*iaddr = MakeInetAddress(*addr);
reply->helloFromServer.yourAddress = *iaddr;
reply->helloFromServer.yourHostId = hostId;
}
break;
}
case Common::TraversalPacketType::ConnectPlease:
{
Common::TraversalHostId& hostId = packet->connectPlease.hostId;
auto r = EvictFind(connectedClients, hostId);
if (!r.found)
{
Common::TraversalPacket* reply = AllocPacket(*addr, toAlt);
reply->type = Common::TraversalPacketType::ConnectFailed;
reply->connectFailed.requestId = packet->requestId;
reply->connectFailed.reason = Common::TraversalConnectFailedReason::NoSuchClient;
}
else
{
Common::TraversalPacket* please =
AllocPacket(MakeSinAddr(*r.value), toAlt, packet->requestId);
please->type = Common::TraversalPacketType::PleaseSendPacket;
please->pleaseSendPacket.address = MakeInetAddress(*addr);
}
break;
}
case Common::TraversalPacketType::TestPlease:
{
Common::TraversalHostId& hostId = packet->testPlease.hostId;
auto r = EvictFind(connectedClients, hostId);
if (r.found)
{
Common::TraversalPacket ack = {};
ack.type = Common::TraversalPacketType::Ack;
ack.requestId = packet->requestId;
ack.ack.ok = true;
sockaddr_in6 mainAddr = MakeSinAddr(*r.value);
TrySend(&ack, sizeof(ack), &mainAddr, toAlt);
}
break;
}
default:
fmt::print(stderr, "received unknown packet type {} from {}\n", static_cast<int>(packet->type),
SenderName(addr));
break;
}
if (packet->type != Common::TraversalPacketType::Ack)
{
Common::TraversalPacket ack = {};
ack.type = Common::TraversalPacketType::Ack;
ack.requestId = packet->requestId;
ack.ack.ok = packetOk;
TrySend(&ack, sizeof(ack), addr,
packet->type != Common::TraversalPacketType::TestPlease ? toAlt : !toAlt);
}
}
int main()
{
int rv;
sock = socket(PF_INET6, SOCK_DGRAM, 0);
if (sock == -1)
{
perror("socket");
return 1;
}
sockAlt = socket(PF_INET6, SOCK_DGRAM, 0);
if (sockAlt == -1)
{
perror("socket alt");
return 1;
}
int no = 0;
rv = setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &no, sizeof(no));
if (rv < 0)
{
perror("setsockopt IPV6_V6ONLY");
return 1;
}
rv = setsockopt(sockAlt, IPPROTO_IPV6, IPV6_V6ONLY, &no, sizeof(no));
if (rv < 0)
{
perror("setsockopt IPV6_V6ONLY alt");
return 1;
}
in6_addr any = IN6ADDR_ANY_INIT;
sockaddr_in6 addr;
#ifdef SIN6_LEN
addr.sin6_len = sizeof(addr);
#endif
addr.sin6_family = AF_INET6;
addr.sin6_port = htons(PORT);
addr.sin6_flowinfo = 0;
addr.sin6_addr = any;
addr.sin6_scope_id = 0;
rv = bind(sock, (sockaddr*)&addr, sizeof(addr));
if (rv < 0)
{
perror("bind");
return 1;
}
addr.sin6_port = htons(PORT_ALT);
rv = bind(sockAlt, (sockaddr*)&addr, sizeof(addr));
if (rv < 0)
{
perror("bind alt");
return 1;
}
timeval tv;
tv.tv_sec = 0;
tv.tv_usec = 300000;
rv = setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
if (rv < 0)
{
perror("setsockopt SO_RCVTIMEO");
return 1;
}
rv = setsockopt(sockAlt, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
if (rv < 0)
{
perror("setsockopt SO_RCVTIMEO alt");
return 1;
}
#ifdef HAVE_LIBSYSTEMD
sd_notifyf(0, "READY=1\nSTATUS=Listening on port %d (alt port: %d)", PORT, PORT_ALT);
#endif
while (true)
{
tv.tv_sec = 0;
tv.tv_usec = 300000;
fd_set readSet;
FD_ZERO(&readSet);
FD_SET(sock, &readSet);
FD_SET(sockAlt, &readSet);
rv = select(std::max(sock, sockAlt) + 1, &readSet, nullptr, nullptr, &tv);
if (rv < 0)
{
if (errno != EINTR && errno != EAGAIN)
{
perror("recvfrom");
return 1;
}
}
int recvsock;
if (FD_ISSET(sock, &readSet))
{
recvsock = sock;
}
else if (FD_ISSET(sockAlt, &readSet))
{
recvsock = sockAlt;
}
else
{
ResendPackets();
continue;
}
sockaddr_in6 raddr;
socklen_t addrLen = sizeof(raddr);
Common::TraversalPacket packet{};
// note: switch to recvmmsg (yes, mmsg) if this becomes
// expensive
rv = recvfrom(recvsock, &packet, sizeof(packet), 0, (sockaddr*)&raddr, &addrLen);
currentTime = std::chrono::duration_cast<std::chrono::microseconds>(
std::chrono::system_clock::now().time_since_epoch())
.count();
if (rv < 0)
{
if (errno != EINTR && errno != EAGAIN)
{
perror("recvfrom");
return 1;
}
}
else if ((size_t)rv < sizeof(packet))
{
fmt::print(stderr, "received short packet from {}\n", SenderName(&raddr));
}
else
{
HandlePacket(&packet, &raddr, recvsock == sockAlt);
}
ResendPackets();
#ifdef HAVE_LIBSYSTEMD
sd_notify(0, "WATCHDOG=1");
#endif
}
}