Socket-related cleanups

Improve error handling on Windows and reduce the size of the `Address` class

4 files changed, 100 insertions, 142 deletions

diff --git a/src/network/address.cpp b/src/network/address.cpp
index 05678aa62..90e561802 100644
--- a/src/network/address.cpp
+++ b/src/network/address.cpp
@@ -87,38 +87,31 @@ Address::Address(const IPv6AddressBytes *ipv6_bytes, u16 port)
 	setPort(port);
 }
 
-// Equality (address family, address and port must be equal)
-bool Address::operator==(const Address &address)
+// Equality (address family, IP and port must be equal)
+bool Address::operator==(const Address &other)
 {
-	if (address.m_addr_family != m_addr_family || address.m_port != m_port)
+	if (other.m_addr_family != m_addr_family || other.m_port != m_port)
 		return false;
 
 	if (m_addr_family == AF_INET) {
-		return m_address.ipv4.sin_addr.s_addr ==
-		       address.m_address.ipv4.sin_addr.s_addr;
+		return m_address.ipv4.s_addr == other.m_address.ipv4.s_addr;
 	}
 
 	if (m_addr_family == AF_INET6) {
-		return memcmp(m_address.ipv6.sin6_addr.s6_addr,
-				       address.m_address.ipv6.sin6_addr.s6_addr, 16) == 0;
+		return memcmp(m_address.ipv6.s6_addr,
+				other.m_address.ipv6.s6_addr, 16) == 0;
 	}
 
 	return false;
 }
 
-bool Address::operator!=(const Address &address)
-{
-	return !(*this == address);
-}
-
 void Address::Resolve(const char *name)
 {
 	if (!name || name[0] == 0) {
-		if (m_addr_family == AF_INET) {
-			setAddress((u32)0);
-		} else if (m_addr_family == AF_INET6) {
-			setAddress((IPv6AddressBytes *)0);
-		}
+		if (m_addr_family == AF_INET)
+			setAddress(static_cast<u32>(0));
+		else if (m_addr_family == AF_INET6)
+			setAddress(static_cast<IPv6AddressBytes*>(nullptr));
 		return;
 	}
 
@@ -126,9 +119,6 @@ void Address::Resolve(const char *name)
 	memset(&hints, 0, sizeof(hints));
 
 	// Setup hints
-	hints.ai_socktype = 0;
-	hints.ai_protocol = 0;
-	hints.ai_flags = 0;
 	if (g_settings->getBool("enable_ipv6")) {
 		// AF_UNSPEC allows both IPv6 and IPv4 addresses to be returned
 		hints.ai_family = AF_UNSPEC;
@@ -145,14 +135,13 @@ void Address::Resolve(const char *name)
 	if (resolved->ai_family == AF_INET) {
 		struct sockaddr_in *t = (struct sockaddr_in *)resolved->ai_addr;
 		m_addr_family = AF_INET;
-		m_address.ipv4 = *t;
+		m_address.ipv4 = t->sin_addr;
 	} else if (resolved->ai_family == AF_INET6) {
 		struct sockaddr_in6 *t = (struct sockaddr_in6 *)resolved->ai_addr;
 		m_addr_family = AF_INET6;
-		m_address.ipv6 = *t;
+		m_address.ipv6 = t->sin6_addr;
 	} else {
-		freeaddrinfo(resolved);
-		throw ResolveError("");
+		m_addr_family = 0;
 	}
 	freeaddrinfo(resolved);
 }
@@ -163,47 +152,37 @@ std::string Address::serializeString() const
 // windows XP doesnt have inet_ntop, maybe use better func
 #ifdef _WIN32
 	if (m_addr_family == AF_INET) {
-		u8 a, b, c, d;
-		u32 addr;
-		addr = ntohl(m_address.ipv4.sin_addr.s_addr);
-		a = (addr & 0xFF000000) >> 24;
-		b = (addr & 0x00FF0000) >> 16;
-		c = (addr & 0x0000FF00) >> 8;
-		d = (addr & 0x000000FF);
-		return itos(a) + "." + itos(b) + "." + itos(c) + "." + itos(d);
+		return inet_ntoa(m_address.ipv4);
 	} else if (m_addr_family == AF_INET6) {
 		std::ostringstream os;
+		os << std::hex;
 		for (int i = 0; i < 16; i += 2) {
-			u16 section = (m_address.ipv6.sin6_addr.s6_addr[i] << 8) |
-				      (m_address.ipv6.sin6_addr.s6_addr[i + 1]);
-			os << std::hex << section;
+			u16 section = (m_address.ipv6.s6_addr[i] << 8) |
+					(m_address.ipv6.s6_addr[i + 1]);
+			os << section;
 			if (i < 14)
 				os << ":";
 		}
 		return os.str();
-	} else
-		return std::string("");
+	} else {
+		return "";
+	}
 #else
 	char str[INET6_ADDRSTRLEN];
-	if (inet_ntop(m_addr_family,
-			    (m_addr_family == AF_INET)
-					    ? (void *)&(m_address.ipv4.sin_addr)
-					    : (void *)&(m_address.ipv6.sin6_addr),
-			    str, INET6_ADDRSTRLEN) == NULL) {
-		return std::string("");
-	}
-	return std::string(str);
+	if (inet_ntop(m_addr_family, (void*) &m_address, str, sizeof(str)) == nullptr)
+		return "";
+	return str;
 #endif
 }
 
-struct sockaddr_in Address::getAddress() const
+struct in_addr Address::getAddress() const
 {
-	return m_address.ipv4; // NOTE: NO PORT INCLUDED, use getPort()
+	return m_address.ipv4;
 }
 
-struct sockaddr_in6 Address::getAddress6() const
+struct in6_addr Address::getAddress6() const
 {
-	return m_address.ipv6; // NOTE: NO PORT INCLUDED, use getPort()
+	return m_address.ipv6;
 }
 
 u16 Address::getPort() const
@@ -211,52 +190,39 @@ u16 Address::getPort() const
 	return m_port;
 }
 
-int Address::getFamily() const
-{
-	return m_addr_family;
-}
-
-bool Address::isIPv6() const
-{
-	return m_addr_family == AF_INET6;
-}
-
 bool Address::isZero() const
 {
 	if (m_addr_family == AF_INET) {
-		return m_address.ipv4.sin_addr.s_addr == 0;
+		return m_address.ipv4.s_addr == 0;
 	}
 
 	if (m_addr_family == AF_INET6) {
 		static const char zero[16] = {0};
-		return memcmp(m_address.ipv6.sin6_addr.s6_addr, zero, 16) == 0;
+		return memcmp(m_address.ipv6.s6_addr, zero, 16) == 0;
 	}
+
 	return false;
 }
 
 void Address::setAddress(u32 address)
 {
 	m_addr_family = AF_INET;
-	m_address.ipv4.sin_family = AF_INET;
-	m_address.ipv4.sin_addr.s_addr = htonl(address);
+	m_address.ipv4.s_addr = htonl(address);
 }
 
 void Address::setAddress(u8 a, u8 b, u8 c, u8 d)
 {
-	m_addr_family = AF_INET;
-	m_address.ipv4.sin_family = AF_INET;
-	u32 addr = htonl((a << 24) | (b << 16) | (c << 8) | d);
-	m_address.ipv4.sin_addr.s_addr = addr;
+	u32 addr = (a << 24) | (b << 16) | (c << 8) | d;
+	setAddress(addr);
 }
 
 void Address::setAddress(const IPv6AddressBytes *ipv6_bytes)
 {
 	m_addr_family = AF_INET6;
-	m_address.ipv6.sin6_family = AF_INET6;
 	if (ipv6_bytes)
-		memcpy(m_address.ipv6.sin6_addr.s6_addr, ipv6_bytes->bytes, 16);
+		memcpy(m_address.ipv6.s6_addr, ipv6_bytes->bytes, 16);
 	else
-		memset(m_address.ipv6.sin6_addr.s6_addr, 0, 16);
+		memset(m_address.ipv6.s6_addr, 0, 16);
 }
 
 void Address::setPort(u16 port)
@@ -268,23 +234,26 @@ void Address::print(std::ostream *s) const
 {
 	if (m_addr_family == AF_INET6)
 		*s << "[" << serializeString() << "]:" << m_port;
-	else
+	else if (m_addr_family == AF_INET)
 		*s << serializeString() << ":" << m_port;
+	else
+		*s << "(undefined)";
 }
 
 bool Address::isLocalhost() const
 {
 	if (isIPv6()) {
-		static const unsigned char localhost_bytes[] = {
+		static const u8 localhost_bytes[] = {
 				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
-		static const unsigned char mapped_ipv4_localhost[] = {
+		static const u8 mapped_ipv4_localhost[] = {
 				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 0x7f, 0, 0, 0};
 
-		auto addr = m_address.ipv6.sin6_addr.s6_addr;
+		auto addr = m_address.ipv6.s6_addr;
 
 		return memcmp(addr, localhost_bytes, 16) == 0 ||
 			memcmp(addr, mapped_ipv4_localhost, 13) == 0;
 	}
 
-	return (m_address.ipv4.sin_addr.s_addr & 0xFF) == 0x7f;
+	auto addr = ntohl(m_address.ipv4.s_addr);
+	return (addr >> 24) == 0x7f;
 }
diff --git a/src/network/address.h b/src/network/address.h
index 4329c84a8..c2f5f2eef 100644
--- a/src/network/address.h
+++ b/src/network/address.h
@@ -36,9 +36,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "irrlichttypes.h"
 #include "networkexceptions.h"
 
-class IPv6AddressBytes
+struct IPv6AddressBytes
 {
-public:
 	u8 bytes[16];
 	IPv6AddressBytes() { memset(bytes, 0, 16); }
 };
@@ -50,30 +49,34 @@ public:
 	Address(u32 address, u16 port);
 	Address(u8 a, u8 b, u8 c, u8 d, u16 port);
 	Address(const IPv6AddressBytes *ipv6_bytes, u16 port);
+
 	bool operator==(const Address &address);
-	bool operator!=(const Address &address);
+	bool operator!=(const Address &address) { return !(*this == address); }
+
+	struct in_addr getAddress() const;
+	struct in6_addr getAddress6() const;
+	u16 getPort() const;
+	int getFamily() const { return m_addr_family; }
+	bool isIPv6() const { return m_addr_family == AF_INET6; }
+	bool isZero() const;
+	void print(std::ostream *s) const;
+	std::string serializeString() const;
+	bool isLocalhost() const;
+
 	// Resolve() may throw ResolveError (address is unchanged in this case)
 	void Resolve(const char *name);
-	struct sockaddr_in getAddress() const;
-	unsigned short getPort() const;
+
 	void setAddress(u32 address);
 	void setAddress(u8 a, u8 b, u8 c, u8 d);
 	void setAddress(const IPv6AddressBytes *ipv6_bytes);
-	struct sockaddr_in6 getAddress6() const;
-	int getFamily() const;
-	bool isIPv6() const;
-	bool isZero() const;
-	void setPort(unsigned short port);
-	void print(std::ostream *s) const;
-	std::string serializeString() const;
-	bool isLocalhost() const;
+	void setPort(u16 port);
 
 private:
-	unsigned int m_addr_family = 0;
+	unsigned short m_addr_family = 0;
 	union
 	{
-		struct sockaddr_in ipv4;
-		struct sockaddr_in6 ipv6;
+		struct in_addr ipv4;
+		struct in6_addr ipv6;
 	} m_address;
 	u16 m_port = 0; // Port is separate from sockaddr structures
 };
diff --git a/src/network/socket.cpp b/src/network/socket.cpp
index 94a9f4180..0bb7ea234 100644
--- a/src/network/socket.cpp
+++ b/src/network/socket.cpp
@@ -23,14 +23,11 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #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
@@ -42,9 +39,10 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <winsock2.h>
 #include <ws2tcpip.h>
 #define LAST_SOCKET_ERR() WSAGetLastError()
-typedef SOCKET socket_t;
+#define SOCKET_ERR_STR(e) itos(e)
 typedef int socklen_t;
 #else
+#include <cerrno>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
@@ -53,7 +51,7 @@ typedef int socklen_t;
 #include <unistd.h>
 #include <arpa/inet.h>
 #define LAST_SOCKET_ERR() (errno)
-typedef int socket_t;
+#define SOCKET_ERR_STR(e) strerror(e)
 #endif
 
 // Set to true to enable verbose debug output
@@ -113,7 +111,7 @@ bool UDPSocket::init(bool ipv6, bool noExceptions)
 		}
 
 		throw SocketException(std::string("Failed to create socket: error ") +
-				      itos(LAST_SOCKET_ERR()));
+				      SOCKET_ERR_STR(LAST_SOCKET_ERR()));
 	}
 
 	setTimeoutMs(0);
@@ -153,40 +151,40 @@ void UDPSocket::Bind(Address addr)
 	}
 
 	if (addr.getFamily() != m_addr_family) {
-		static const char *errmsg =
+		const char *errmsg =
 				"Socket and bind address families do not match";
 		errorstream << "Bind failed: " << errmsg << std::endl;
 		throw SocketException(errmsg);
 	}
 
+	int ret = 0;
+
 	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_addr = addr.getAddress6();
 		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");
-		}
+		ret = bind(m_handle, (const struct sockaddr *) &address,
+				sizeof(struct sockaddr_in6));
 	} else {
 		struct sockaddr_in address;
 		memset(&address, 0, sizeof(address));
 
-		address = addr.getAddress();
 		address.sin_family = AF_INET;
+		address.sin_addr = addr.getAddress();
 		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");
-		}
+		ret = bind(m_handle, (const struct sockaddr *) &address,
+			sizeof(struct sockaddr_in));
+	}
+
+	if (ret < 0) {
+		dstream << (int)m_handle << ": Bind failed: "
+			<< SOCKET_ERR_STR(LAST_SOCKET_ERR()) << std::endl;
+		throw SocketException("Failed to bind socket");
 	}
 }
 
@@ -233,13 +231,19 @@ void UDPSocket::Send(const Address &destination, const void *data, int size)
 
 	int sent;
 	if (m_addr_family == AF_INET6) {
-		struct sockaddr_in6 address = destination.getAddress6();
+		struct sockaddr_in6 address = {0};
+		address.sin6_family = AF_INET6;
+		address.sin6_addr = 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();
+		struct sockaddr_in address = {0};
+		address.sin_family = AF_INET;
+		address.sin_addr = destination.getAddress();
 		address.sin_port = htons(destination.getPort());
+
 		sent = sendto(m_handle, (const char *)data, size, 0,
 				(struct sockaddr *)&address, sizeof(struct sockaddr_in));
 	}
@@ -267,9 +271,9 @@ int UDPSocket::Receive(Address &sender, void *data, int size)
 			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);
+		const auto *bytes = reinterpret_cast<IPv6AddressBytes*>
+			(address.sin6_addr.s6_addr);
+		sender = Address(bytes, address_port);
 	} else {
 		struct sockaddr_in address;
 		memset(&address, 0, sizeof(address));
@@ -341,7 +345,12 @@ bool UDPSocket::WaitData(int timeout_ms)
 	if (result == 0)
 		return false;
 
-	if (result < 0 && (errno == EINTR || errno == EBADF)) {
+	int e = LAST_SOCKET_ERR();
+#ifdef _WIN32
+	if (result < 0 && (e == WSAEINTR || e == WSAEBADF)) {
+#else
+	if (result < 0 && (e == EINTR || e == EBADF)) {
+#endif
 		// 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.
@@ -349,18 +358,9 @@ bool UDPSocket::WaitData(int timeout_ms)
 	}
 
 	if (result < 0) {
-		dstream << m_handle << ": Select failed: " << strerror(errno)
+		dstream << (int)m_handle << ": Select failed: " << SOCKET_ERR_STR(e)
 			<< 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
diff --git a/src/network/socket.h b/src/network/socket.h
index e0e76f4c2..d34186b44 100644
--- a/src/network/socket.h
+++ b/src/network/socket.h
@@ -19,18 +19,6 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #pragma once
 
-#ifdef _WIN32
-#ifndef _WIN32_WINNT
-#define _WIN32_WINNT 0x0501
-#endif
-#include <windows.h>
-#include <winsock2.h>
-#include <ws2tcpip.h>
-#else
-#include <sys/socket.h>
-#include <netinet/in.h>
-#endif
-
 #include <ostream>
 #include <cstring>
 #include "address.h"
@@ -53,8 +41,6 @@ public:
 
 	bool init(bool ipv6, bool noExceptions = false);
 
-	// void Close();
-	// bool IsOpen();
 	void Send(const Address &destination, const void *data, int size);
 	// Returns -1 if there is no data
 	int Receive(Address &sender, void *data, int size);