net/IPv4Address: new class

Makefile.am

@@ -482,6 +482,7 @@ libnet_a_SOURCES = \
 	src/net/Resolver.cxx src/net/Resolver.hxx \
 	src/net/StaticSocketAddress.cxx src/net/StaticSocketAddress.hxx \
 	src/net/AllocatedSocketAddress.cxx src/net/AllocatedSocketAddress.hxx \
+	src/net/IPv4Address.cxx src/net/IPv4Address.hxx \
 	src/net/SocketAddress.cxx src/net/SocketAddress.hxx \
 	src/net/SocketUtil.cxx src/net/SocketUtil.hxx \
 	src/net/SocketDescriptor.cxx src/net/SocketDescriptor.hxx \

src/event/ServerSocket.cxx

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "ServerSocket.hxx"
+#include "net/IPv4Address.hxx"
 #include "net/StaticSocketAddress.hxx"
 #include "net/AllocatedSocketAddress.hxx"
 #include "net/SocketAddress.hxx"
@@ -48,7 +49,6 @@
 #include <ws2tcpip.h>
 #include <winsock.h>
 #else
-#include <netinet/in.h>
 #include <sys/socket.h>
 #include <netdb.h>
 #endif
@@ -310,13 +310,7 @@ ServerSocket::AddFD(int _fd)
 inline void
 ServerSocket::AddPortIPv4(unsigned port)
 {
-	struct sockaddr_in sin;
-	memset(&sin, 0, sizeof(sin));
-	sin.sin_port = htons(port);
-	sin.sin_family = AF_INET;
-	sin.sin_addr.s_addr = INADDR_ANY;
-
-	AddAddress({(const sockaddr *)&sin, sizeof(sin)});
+	AddAddress(IPv4Address(port));
 }
 
 #ifdef HAVE_IPV6

src/net/IPv4Address.cxx

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2012-2017 Max Kellermann <max.kellermann@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "IPv4Address.hxx"
+
+#include <assert.h>
+
+static const struct sockaddr_in *
+CastToIPv4(const struct sockaddr *p)
+{
+	assert(p->sa_family == AF_INET);
+
+	/* cast through void to work around the bogus alignment warning */
+	const void *q = reinterpret_cast<const void *>(p);
+	return reinterpret_cast<const struct sockaddr_in *>(q);
+}
+
+IPv4Address::IPv4Address(SocketAddress src)
+	:address(*CastToIPv4(src.GetAddress())) {}

src/net/IPv4Address.hxx

@@ -0,0 +1,147 @@
+/*
+ * Copyright (C) 2012-2017 Max Kellermann <max.kellermann@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef IPV4_ADDRESS_HXX
+#define IPV4_ADDRESS_HXX
+
+#include "SocketAddress.hxx"
+#include "system/ByteOrder.hxx"
+
+#include <stdint.h>
+
+#ifdef _WIN32
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#else
+#include <netinet/in.h>
+#endif
+
+/**
+ * An OO wrapper for struct sockaddr_in.
+ */
+class IPv4Address {
+	struct sockaddr_in address;
+
+#ifdef WIN32
+	static constexpr struct in_addr ConstructInAddr(uint8_t a, uint8_t b,
+							uint8_t c, uint8_t d) {
+		return {{{ a, b, c, d }}};
+	}
+
+	static constexpr struct in_addr ConstructInAddr(uint32_t x) {
+		return ConstructInAddr(x >> 24, x >> 16, x >> 8, x);
+	}
+#else
+
+#ifdef __BIONIC__
+	typedef uint32_t in_addr_t;
+#endif
+
+	static constexpr in_addr_t ConstructInAddrT(uint8_t a, uint8_t b,
+						    uint8_t c, uint8_t d) {
+		return ToBE32((a << 24) | (b << 16) | (c << 8) | d);
+	}
+
+	static constexpr struct in_addr ConstructInAddr(uint32_t x) {
+		return { ToBE32(x) };
+	}
+
+	static constexpr struct in_addr ConstructInAddr(uint8_t a, uint8_t b,
+							uint8_t c, uint8_t d) {
+		return { ConstructInAddrT(a, b, c, d) };
+	}
+#endif
+
+	static constexpr struct sockaddr_in Construct(struct in_addr address,
+						      uint16_t port) {
+		return {
+#if defined(__APPLE__)
+			sizeof(struct sockaddr_in),
+#endif
+			AF_INET,
+			ToBE16(port),
+			address,
+			{},
+		};
+	}
+
+	static constexpr struct sockaddr_in Construct(uint32_t address,
+						      uint16_t port) {
+		return Construct(ConstructInAddr(address), port);
+	}
+
+public:
+	IPv4Address() = default;
+
+	constexpr IPv4Address(struct in_addr _address, uint16_t port)
+		:address(Construct(_address, port)) {}
+
+	constexpr IPv4Address(uint8_t a, uint8_t b, uint8_t c,
+			      uint8_t d, uint16_t port)
+		:IPv4Address(ConstructInAddr(a, b, c, d), port) {}
+
+	constexpr explicit IPv4Address(uint16_t port)
+		:IPv4Address(ConstructInAddr(INADDR_ANY), port) {}
+
+	/**
+	 * Convert a #SocketAddress to a #IPv4Address.  Its address family must be AF_INET.
+	 */
+	explicit IPv4Address(SocketAddress src);
+
+	static constexpr struct in_addr Loopback() {
+		return ConstructInAddr(INADDR_LOOPBACK);
+	}
+
+	operator SocketAddress() const {
+		return SocketAddress(reinterpret_cast<const struct sockaddr *>(&address),
+				     sizeof(address));
+	}
+
+	SocketAddress::size_type GetSize() {
+		return sizeof(address);
+	}
+
+	constexpr bool IsDefined() const {
+		return address.sin_family != AF_UNSPEC;
+	}
+
+	constexpr uint16_t GetPort() const {
+		return FromBE16(address.sin_port);
+	}
+
+	void SetPort(uint16_t port) {
+		address.sin_port = ToBE16(port);
+	}
+
+	constexpr const struct in_addr &GetAddress() const {
+		return address.sin_addr;
+	}
+};
+
+#endif

src/system/EventPipe.cxx

@@ -28,9 +28,9 @@
 #include <unistd.h>
 
 #ifdef WIN32
-#include <ws2tcpip.h>
+#include "net/IPv4Address.hxx"
+
 #include <winsock2.h>
-#include <cstring> /* for memset() */
 #endif
 
 #ifdef WIN32
@@ -112,14 +112,10 @@ static bool PoorSocketPair(int fd[2])
 		closesocket(listen_socket);
 	};
 
-	sockaddr_in address;
-	std::memset(&address, 0, sizeof(address));
-	address.sin_family = AF_INET;
-	address.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+	IPv4Address address(IPv4Address::Loopback(), 0);
 
 	int ret = bind(listen_socket,
-		       reinterpret_cast<sockaddr*>(&address),
-		       sizeof(address));
+		       SocketAddress(address).GetAddress(), sizeof(address));
 
 	if (ret < 0)
 		return false;