minetest/src/network/socket.cpp

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/*
Minetest
Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
This program 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "socket.h"
#include <cstdio>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cerrno>
#include <sstream>
#include <iomanip>
#include "util/string.h"
#include "util/numeric.h"
#include "constants.h"
#include "debug.h"
#include "settings.h"
#include "log.h"
#ifdef _WIN32
// Without this some of the network functions are not found on mingw
#ifndef _WIN32_WINNT
#define _WIN32_WINNT 0x0501
#endif
#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#define LAST_SOCKET_ERR() WSAGetLastError()
typedef SOCKET socket_t;
typedef int socklen_t;
#else
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <fcntl.h>
#include <netdb.h>
#include <unistd.h>
#include <arpa/inet.h>
#define LAST_SOCKET_ERR() (errno)
typedef int socket_t;
#endif
// Set to true to enable verbose debug output
bool socket_enable_debug_output = false; // yuck
static bool g_sockets_initialized = false;
// Initialize sockets
void sockets_init()
{
#ifdef _WIN32
// Windows needs sockets to be initialized before use
WSADATA WsaData;
if (WSAStartup(MAKEWORD(2, 2), &WsaData) != NO_ERROR)
throw SocketException("WSAStartup failed");
#endif
g_sockets_initialized = true;
}
void sockets_cleanup()
{
#ifdef _WIN32
// On Windows, cleanup sockets after use
WSACleanup();
#endif
}
/*
UDPSocket
*/
UDPSocket::UDPSocket(bool ipv6)
{
init(ipv6, false);
}
bool UDPSocket::init(bool ipv6, bool noExceptions)
{
if (!g_sockets_initialized) {
dstream << "Sockets not initialized" << std::endl;
return false;
}
// Use IPv6 if specified
m_addr_family = ipv6 ? AF_INET6 : AF_INET;
m_handle = socket(m_addr_family, SOCK_DGRAM, IPPROTO_UDP);
if (socket_enable_debug_output) {
dstream << "UDPSocket(" << (int)m_handle
<< ")::UDPSocket(): ipv6 = " << (ipv6 ? "true" : "false")
<< std::endl;
}
if (m_handle <= 0) {
if (noExceptions) {
return false;
}
throw SocketException(std::string("Failed to create socket: error ") +
itos(LAST_SOCKET_ERR()));
}
setTimeoutMs(0);
if (m_addr_family == AF_INET6) {
// Allow our socket to accept both IPv4 and IPv6 connections
// required on Windows:
// https://msdn.microsoft.com/en-us/library/windows/desktop/bb513665(v=vs.85).aspx
int value = 0;
setsockopt(m_handle, IPPROTO_IPV6, IPV6_V6ONLY,
reinterpret_cast<char *>(&value), sizeof(value));
}
return true;
}
UDPSocket::~UDPSocket()
{
if (socket_enable_debug_output) {
dstream << "UDPSocket( " << (int)m_handle << ")::~UDPSocket()"
<< std::endl;
}
#ifdef _WIN32
closesocket(m_handle);
#else
close(m_handle);
#endif
}
void UDPSocket::Bind(Address addr)
{
if (socket_enable_debug_output) {
dstream << "UDPSocket(" << (int)m_handle
<< ")::Bind(): " << addr.serializeString() << ":"
<< addr.getPort() << std::endl;
}
if (addr.getFamily() != m_addr_family) {
static const char *errmsg =
"Socket and bind address families do not match";
errorstream << "Bind failed: " << errmsg << std::endl;
throw SocketException(errmsg);
}
if (m_addr_family == AF_INET6) {
struct sockaddr_in6 address;
memset(&address, 0, sizeof(address));
address = addr.getAddress6();
address.sin6_family = AF_INET6;
address.sin6_port = htons(addr.getPort());
if (bind(m_handle, (const struct sockaddr *)&address,
sizeof(struct sockaddr_in6)) < 0) {
dstream << (int)m_handle << ": Bind failed: " << strerror(errno)
<< std::endl;
throw SocketException("Failed to bind socket");
}
} else {
struct sockaddr_in address;
memset(&address, 0, sizeof(address));
address = addr.getAddress();
address.sin_family = AF_INET;
address.sin_port = htons(addr.getPort());
if (bind(m_handle, (const struct sockaddr *)&address,
sizeof(struct sockaddr_in)) < 0) {
dstream << (int)m_handle << ": Bind failed: " << strerror(errno)
<< std::endl;
throw SocketException("Failed to bind socket");
}
}
}
void UDPSocket::Send(const Address &destination, const void *data, int size)
{
bool dumping_packet = false; // for INTERNET_SIMULATOR
if (INTERNET_SIMULATOR)
dumping_packet = myrand() % INTERNET_SIMULATOR_PACKET_LOSS == 0;
if (socket_enable_debug_output) {
// Print packet destination and size
dstream << (int)m_handle << " -> ";
destination.print(&dstream);
dstream << ", size=" << size;
// Print packet contents
dstream << ", data=";
for (int i = 0; i < size && i < 20; i++) {
if (i % 2 == 0)
dstream << " ";
unsigned int a = ((const unsigned char *)data)[i];
dstream << std::hex << std::setw(2) << std::setfill('0') << a;
}
if (size > 20)
dstream << "...";
if (dumping_packet)
dstream << " (DUMPED BY INTERNET_SIMULATOR)";
dstream << std::endl;
}
if (dumping_packet) {
// Lol let's forget it
dstream << "UDPSocket::Send(): INTERNET_SIMULATOR: dumping packet."
<< std::endl;
return;
}
if (destination.getFamily() != m_addr_family)
throw SendFailedException("Address family mismatch");
int sent;
if (m_addr_family == AF_INET6) {
struct sockaddr_in6 address = destination.getAddress6();
address.sin6_port = htons(destination.getPort());
sent = sendto(m_handle, (const char *)data, size, 0,
(struct sockaddr *)&address, sizeof(struct sockaddr_in6));
} else {
struct sockaddr_in address = destination.getAddress();
address.sin_port = htons(destination.getPort());
sent = sendto(m_handle, (const char *)data, size, 0,
(struct sockaddr *)&address, sizeof(struct sockaddr_in));
}
if (sent != size)
throw SendFailedException("Failed to send packet");
}
int UDPSocket::Receive(Address &sender, void *data, int size)
{
// Return on timeout
if (!WaitData(m_timeout_ms))
return -1;
int received;
if (m_addr_family == AF_INET6) {
struct sockaddr_in6 address;
memset(&address, 0, sizeof(address));
socklen_t address_len = sizeof(address);
received = recvfrom(m_handle, (char *)data, size, 0,
(struct sockaddr *)&address, &address_len);
if (received < 0)
return -1;
u16 address_port = ntohs(address.sin6_port);
IPv6AddressBytes bytes;
memcpy(bytes.bytes, address.sin6_addr.s6_addr, 16);
sender = Address(&bytes, address_port);
} else {
struct sockaddr_in address;
memset(&address, 0, sizeof(address));
socklen_t address_len = sizeof(address);
received = recvfrom(m_handle, (char *)data, size, 0,
(struct sockaddr *)&address, &address_len);
if (received < 0)
return -1;
u32 address_ip = ntohl(address.sin_addr.s_addr);
u16 address_port = ntohs(address.sin_port);
sender = Address(address_ip, address_port);
}
if (socket_enable_debug_output) {
// Print packet sender and size
dstream << (int)m_handle << " <- ";
sender.print(&dstream);
dstream << ", size=" << received;
// Print packet contents
dstream << ", data=";
for (int i = 0; i < received && i < 20; i++) {
if (i % 2 == 0)
dstream << " ";
unsigned int a = ((const unsigned char *)data)[i];
dstream << std::hex << std::setw(2) << std::setfill('0') << a;
}
if (received > 20)
dstream << "...";
dstream << std::endl;
}
return received;
}
int UDPSocket::GetHandle()
{
return m_handle;
}
void UDPSocket::setTimeoutMs(int timeout_ms)
{
m_timeout_ms = timeout_ms;
}
bool UDPSocket::WaitData(int timeout_ms)
{
fd_set readset;
int result;
// Initialize the set
FD_ZERO(&readset);
FD_SET(m_handle, &readset);
// Initialize time out struct
struct timeval tv;
tv.tv_sec = 0;
tv.tv_usec = timeout_ms * 1000;
// select()
result = select(m_handle + 1, &readset, NULL, NULL, &tv);
if (result == 0)
return false;
if (result < 0 && (errno == EINTR || errno == EBADF)) {
// N.B. select() fails when sockets are destroyed on Connection's dtor
// with EBADF. Instead of doing tricky synchronization, allow this
// thread to exit but don't throw an exception.
return false;
}
if (result < 0) {
dstream << m_handle << ": Select failed: " << strerror(errno)
<< std::endl;
#ifdef _WIN32
int e = WSAGetLastError();
dstream << (int)m_handle << ": WSAGetLastError()=" << e << std::endl;
if (e == 10004 /* WSAEINTR */ || e == 10009 /* WSAEBADF */) {
infostream << "Ignoring WSAEINTR/WSAEBADF." << std::endl;
return false;
}
#endif
throw SocketException("Select failed");
} else if (!FD_ISSET(m_handle, &readset)) {
// No data
return false;
}
// There is data
return true;
}