net/SocketAddress: light wrapper for struct sockaddr

Makefile.am

@@ -421,6 +421,7 @@ libthread_a_SOURCES = \
 
 libnet_a_SOURCES = \
 	src/net/Resolver.cxx src/net/Resolver.hxx \
+	src/net/SocketAddress.cxx src/net/SocketAddress.hxx \
 	src/net/SocketUtil.cxx src/net/SocketUtil.hxx \
 	src/net/SocketError.cxx src/net/SocketError.hxx
 

src/Listen.cxx

@@ -23,6 +23,7 @@
 #include "config/Param.hxx"
 #include "config/ConfigGlobal.hxx"
 #include "config/ConfigOption.hxx"
+#include "net/SocketAddress.hxx"
 #include "event/ServerSocket.hxx"
 #include "util/Error.hxx"
 #include "util/Domain.hxx"
@@ -48,10 +49,9 @@ public:
 		:ServerSocket(_loop), partition(_partition) {}
 
 private:
-	void OnAccept(int fd, const sockaddr &address,
-		      size_t address_length, int uid) override {
+	void OnAccept(int fd, SocketAddress address, int uid) override {
 		client_new(GetEventLoop(), partition,
-			   fd, &address, address_length, uid);
+			   fd, address, uid);
 	}
 };
 

src/client/Client.hxx

@@ -36,7 +36,7 @@
 #include <stddef.h>
 #include <stdarg.h>
 
-struct sockaddr;
+class SocketAddress;
 class EventLoop;
 class Path;
 struct Partition;
@@ -204,7 +204,7 @@ void client_manager_init(void);
 
 void
 client_new(EventLoop &loop, Partition &partition,
-	   int fd, const sockaddr *sa, size_t sa_length, int uid);
+	   int fd, SocketAddress address, int uid);
 
 /**
  * Write a C string to the client.

src/client/ClientNew.cxx

@@ -23,6 +23,7 @@
 #include "Partition.hxx"
 #include "Instance.hxx"
 #include "system/fd_util.h"
+#include "net/SocketAddress.hxx"
 #include "net/Resolver.hxx"
 #include "Permission.hxx"
 #include "util/Error.hxx"
@@ -58,15 +59,15 @@ Client::Client(EventLoop &_loop, Partition &_partition,
 
 void
 client_new(EventLoop &loop, Partition &partition,
-	   int fd, const struct sockaddr *sa, size_t sa_length, int uid)
+	   int fd, SocketAddress address, int uid)
 {
 	static unsigned int next_client_num;
-	const auto remote = sockaddr_to_string(sa, sa_length);
+	const auto remote = sockaddr_to_string(address);
 
 	assert(fd >= 0);
 
 #ifdef HAVE_LIBWRAP
-	if (sa->sa_family != AF_UNIX) {
+	if (address.GetFamily() != AF_UNIX) {
 		// TODO: shall we obtain the program name from argv[0]?
 		const char *progname = "mpd";
 

src/event/ServerSocket.cxx

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "ServerSocket.hxx"
+#include "net/SocketAddress.hxx"
 #include "net/SocketUtil.hxx"
 #include "net/SocketError.hxx"
 #include "net/Resolver.hxx"
@@ -59,29 +60,28 @@ class OneServerSocket final : private SocketMonitor {
 
 	AllocatedPath path;
 
-	size_t address_length;
-	struct sockaddr *address;
+	SocketAddress address;
 
 public:
 	OneServerSocket(EventLoop &_loop, ServerSocket &_parent,
 			unsigned _serial,
-			const struct sockaddr *_address,
-			size_t _address_length)
+			SocketAddress _address)
 		:SocketMonitor(_loop),
 		 parent(_parent), serial(_serial),
 		 path(AllocatedPath::Null()),
-		 address_length(_address_length),
-		 address((sockaddr *)xmemdup(_address, _address_length))
+		 address((sockaddr *)xmemdup(_address.GetAddress(),
+					     _address.GetSize()),
+			 _address.GetSize())
 	{
-		assert(_address != nullptr);
-		assert(_address_length > 0);
+		assert(!_address.IsNull());
+		assert(_address.GetSize() > 0);
 	}
 
 	OneServerSocket(const OneServerSocket &other) = delete;
 	OneServerSocket &operator=(const OneServerSocket &other) = delete;
 
 	~OneServerSocket() {
-		free(address);
+		free(const_cast<struct sockaddr *>(address.GetAddress()));
 
 		if (IsDefined())
 			Close();
@@ -104,7 +104,7 @@ public:
 
 	gcc_pure
 	std::string ToString() const {
-		return sockaddr_to_string(address, address_length);
+		return sockaddr_to_string(address);
 	}
 
 	void SetFD(int _fd) {
@@ -168,8 +168,8 @@ OneServerSocket::Accept()
 	}
 
 	parent.OnAccept(peer_fd,
-			(const sockaddr &)peer_address,
-			peer_address_length, get_remote_uid(peer_fd));
+			{ (const sockaddr *)&peer_address, socklen_t(peer_address_length) },
+			get_remote_uid(peer_fd));
 }
 
 bool
@@ -184,9 +184,9 @@ OneServerSocket::Open(Error &error)
 {
 	assert(!IsDefined());
 
-	int _fd = socket_bind_listen(address->sa_family,
+	int _fd = socket_bind_listen(address.GetFamily(),
 				     SOCK_STREAM, 0,
-				     address, address_length, 5,
+				     address, 5,
 				     error);
 	if (_fd < 0)
 		return false;
@@ -280,10 +280,10 @@ ServerSocket::Close()
 }
 
 OneServerSocket &
-ServerSocket::AddAddress(const sockaddr &address, size_t address_length)
+ServerSocket::AddAddress(SocketAddress address)
 {
 	sockets.emplace_back(loop, *this, next_serial,
-			     &address, address_length);
+			     address);
 
 	return sockets.back();
 }
@@ -302,8 +302,7 @@ ServerSocket::AddFD(int fd, Error &error)
 		return false;
 	}
 
-	OneServerSocket &s = AddAddress((const sockaddr &)address,
-					address_length);
+	OneServerSocket &s = AddAddress({(const sockaddr *)&address, address_length});
 	s.SetFD(fd);
 
 	return true;
@@ -320,7 +319,7 @@ ServerSocket::AddPortIPv4(unsigned port)
 	sin.sin_family = AF_INET;
 	sin.sin_addr.s_addr = INADDR_ANY;
 
-	AddAddress((const sockaddr &)sin, sizeof(sin));
+	AddAddress({(const sockaddr *)&sin, sizeof(sin)});
 }
 
 #ifdef HAVE_IPV6
@@ -333,7 +332,7 @@ ServerSocket::AddPortIPv6(unsigned port)
 	sin.sin6_port = htons(port);
 	sin.sin6_family = AF_INET6;
 
-	AddAddress((const sockaddr &)sin, sizeof(sin));
+	AddAddress({(const sockaddr *)&sin, sizeof(sin)});
 }
 
 /**
@@ -392,7 +391,7 @@ ServerSocket::AddHost(const char *hostname, unsigned port, Error &error)
 		return false;
 
 	for (const struct addrinfo *i = ai; i != nullptr; i = i->ai_next)
-		AddAddress(*i->ai_addr, i->ai_addrlen);
+		AddAddress(SocketAddress(i->ai_addr, i->ai_addrlen));
 
 	freeaddrinfo(ai);
 
@@ -426,7 +425,7 @@ ServerSocket::AddPath(AllocatedPath &&path, Error &error)
 	s_un.sun_family = AF_UNIX;
 	memcpy(s_un.sun_path, path.c_str(), path_length + 1);
 
-	OneServerSocket &s = AddAddress((const sockaddr &)s_un, sizeof(s_un));
+	OneServerSocket &s = AddAddress({(const sockaddr *)&s_un, sizeof(s_un)});
 	s.SetPath(std::move(path));
 
 	return true;

src/event/ServerSocket.hxx

@@ -24,7 +24,7 @@
 
 #include <stddef.h>
 
-struct sockaddr;
+class SocketAddress;
 class EventLoop;
 class Error;
 class AllocatedPath;
@@ -51,7 +51,7 @@ public:
 	}
 
 private:
-	OneServerSocket &AddAddress(const sockaddr &address, size_t length);
+	OneServerSocket &AddAddress(SocketAddress address);
 
 	/**
 	 * Add a listener on a port on all IPv4 interfaces.
@@ -111,8 +111,7 @@ public:
 	void Close();
 
 protected:
-	virtual void OnAccept(int fd, const sockaddr &address,
-			      size_t address_length, int uid) = 0;
+	virtual void OnAccept(int fd, SocketAddress address, int uid) = 0;
 };
 
 #endif

src/net/Resolver.cxx

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "Resolver.hxx"
+#include "SocketAddress.hxx"
 #include "util/Error.hxx"
 #include "util/Domain.hxx"
 
@@ -43,13 +44,14 @@
 const Domain resolver_domain("resolver");
 
 std::string
-sockaddr_to_string(const struct sockaddr *sa, size_t length)
+sockaddr_to_string(SocketAddress address)
 {
 #ifdef HAVE_UN
-	if (sa->sa_family == AF_UNIX) {
+	if (address.GetFamily() == AF_UNIX) {
 		/* return path of UNIX domain sockets */
-		const sockaddr_un &s_un = *(const sockaddr_un *)sa;
-		if (length < sizeof(s_un) || s_un.sun_path[0] == 0)
+		const sockaddr_un &s_un = *(const sockaddr_un *)
+			address.GetAddress();
+		if (address.GetSize() < sizeof(s_un) || s_un.sun_path[0] == 0)
 			return "local";
 
 		return s_un.sun_path;
@@ -57,14 +59,15 @@ sockaddr_to_string(const struct sockaddr *sa, size_t length)
 #endif
 
 #if defined(HAVE_IPV6) && defined(IN6_IS_ADDR_V4MAPPED)
-	const struct sockaddr_in6 *a6 = (const struct sockaddr_in6 *)sa;
+	const struct sockaddr_in6 *a6 = (const struct sockaddr_in6 *)
+		address.GetAddress();
 	struct sockaddr_in a4;
 #endif
 	int ret;
 	char host[NI_MAXHOST], serv[NI_MAXSERV];
 
 #if defined(HAVE_IPV6) && defined(IN6_IS_ADDR_V4MAPPED)
-	if (sa->sa_family == AF_INET6 &&
+	if (address.GetFamily() == AF_INET6 &&
 	    IN6_IS_ADDR_V4MAPPED(&a6->sin6_addr)) {
 		/* convert "::ffff:127.0.0.1" to "127.0.0.1" */
 
@@ -74,12 +77,12 @@ sockaddr_to_string(const struct sockaddr *sa, size_t length)
 		       sizeof(a4.sin_addr));
 		a4.sin_port = a6->sin6_port;
 
-		sa = (const struct sockaddr *)&a4;
-		length = sizeof(a4);
+		address = { (const struct sockaddr *)&a4, sizeof(a4) };
 	}
 #endif
 
-	ret = getnameinfo(sa, length, host, sizeof(host), serv, sizeof(serv),
+	ret = getnameinfo(address.GetAddress(), address.GetSize(),
+			  host, sizeof(host), serv, sizeof(serv),
 			  NI_NUMERICHOST|NI_NUMERICSERV);
 	if (ret != 0)
 		return "unknown";

src/net/Resolver.hxx

@@ -26,10 +26,10 @@
 
 #include <stddef.h>
 
-struct sockaddr;
 struct addrinfo;
 class Error;
 class Domain;
+class SocketAddress;
 
 extern const Domain resolver_domain;
 
@@ -42,7 +42,7 @@ extern const Domain resolver_domain;
  */
 gcc_pure
 std::string
-sockaddr_to_string(const sockaddr *sa, size_t length);
+sockaddr_to_string(SocketAddress address);
 
 /**
  * Resolve a specification in the form "host", "host:port",

src/net/SocketAddress.cxx

+/*
+ * Copyright (C) 2012-2015 Max Kellermann <max@duempel.org>
+ *
+ * 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 "SocketAddress.hxx"
+
+#include <string.h>
+
+bool
+SocketAddress::operator==(SocketAddress other) const
+{
+	return size == other.size && memcmp(address, other.address, size) == 0;
+}

src/net/SocketAddress.hxx

+/*
+ * Copyright (C) 2012-2015 Max Kellermann <max@duempel.org>
+ *
+ * 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 SOCKET_ADDRESS_HXX
+#define SOCKET_ADDRESS_HXX
+
+#include "Compiler.h"
+
+#include <cstddef>
+
+#ifdef WIN32
+#include <winsock2.h>
+#else
+#include <sys/socket.h>
+#endif
+
+/**
+ * An OO wrapper for struct sockaddr.
+ */
+class SocketAddress {
+public:
+#ifdef WIN32
+	typedef int size_type;
+#else
+	typedef socklen_t size_type;
+#endif
+
+private:
+	const struct sockaddr *address;
+	size_type size;
+
+public:
+	SocketAddress() = default;
+
+	constexpr SocketAddress(std::nullptr_t):address(nullptr), size(0) {}
+
+	constexpr SocketAddress(const struct sockaddr *_address,
+				size_type _size)
+		:address(_address), size(_size) {}
+
+	static constexpr SocketAddress Null() {
+		return nullptr;
+	}
+
+	constexpr bool IsNull() const {
+		return address == nullptr;
+	}
+
+	const struct sockaddr *GetAddress() const {
+		return address;
+	}
+
+	constexpr size_type GetSize() const {
+		return size;
+	}
+
+	constexpr int GetFamily() const {
+		return address->sa_family;
+	}
+
+	/**
+	 * Does the object have a well-defined address?  Check !IsNull()
+	 * before calling this method.
+	 */
+	bool IsDefined() const {
+		return GetFamily() != AF_UNSPEC;
+	}
+
+	gcc_pure
+	bool operator==(const SocketAddress other) const;
+
+	bool operator!=(const SocketAddress other) const {
+		return !(*this == other);
+	}
+};
+
+#endif

src/net/SocketUtil.cxx

@@ -19,25 +19,19 @@
 
 #include "config.h"
 #include "SocketUtil.hxx"
+#include "SocketAddress.hxx"
 #include "SocketError.hxx"
 #include "system/fd_util.h"
 
 #include <unistd.h>
 
-#ifndef WIN32
-#include <sys/socket.h>
-#else
-#include <ws2tcpip.h>
-#include <winsock.h>
-#endif
-
 #ifdef HAVE_IPV6
 #include <string.h>
 #endif
 
 int
 socket_bind_listen(int domain, int type, int protocol,
-		   const struct sockaddr *address, size_t address_length,
+		   SocketAddress address,
 		   int backlog,
 		   Error &error)
 {
@@ -60,7 +54,7 @@ socket_bind_listen(int domain, int type, int protocol,
 		return -1;
 	}
 
-	ret = bind(fd, address, address_length);
+	ret = bind(fd, address.GetAddress(), address.GetSize());
 	if (ret < 0) {
 		SetSocketError(error);
 		close_socket(fd);

src/net/SocketUtil.hxx

@@ -26,9 +26,7 @@
 #ifndef MPD_SOCKET_UTIL_HXX
 #define MPD_SOCKET_UTIL_HXX
 
-#include <stddef.h>
-
-struct sockaddr;
+class SocketAddress;
 class Error;
 
 /**
@@ -47,7 +45,7 @@ class Error;
  */
 int
 socket_bind_listen(int domain, int type, int protocol,
-		   const struct sockaddr *address, size_t address_length,
+		   SocketAddress address,
 		   int backlog,
 		   Error &error);
 

src/output/plugins/httpd/HttpdInternal.hxx

@@ -259,8 +259,7 @@ public:
 private:
 	virtual void RunDeferred() override;
 
-	virtual void OnAccept(int fd, const sockaddr &address,
-			      size_t address_length, int uid) override;
+	void OnAccept(int fd, SocketAddress address, int uid) override;
 };
 
 extern const class Domain httpd_output_domain;

src/output/plugins/httpd/HttpdOutputPlugin.cxx

@@ -26,6 +26,7 @@
 #include "encoder/EncoderPlugin.hxx"
 #include "encoder/EncoderList.hxx"
 #include "net/Resolver.hxx"
+#include "net/SocketAddress.hxx"
 #include "Page.hxx"
 #include "IcyMetaDataServer.hxx"
 #include "system/fd_util.h"
@@ -201,16 +202,14 @@ HttpdOutput::RunDeferred()
 }
 
 void
-HttpdOutput::OnAccept(int fd, const sockaddr &address,
-		      size_t address_length, gcc_unused int uid)
+HttpdOutput::OnAccept(int fd, SocketAddress address, gcc_unused int uid)
 {
 	/* the listener socket has become readable - a client has
 	   connected */
 
 #ifdef HAVE_LIBWRAP
-	if (address.sa_family != AF_UNIX) {
-		const auto hostaddr = sockaddr_to_string(&address,
-							 address_length);
+	if (address.GetFamily() != AF_UNIX) {
+		const auto hostaddr = sockaddr_to_string(address);
 		// TODO: shall we obtain the program name from argv[0]?
 		const char *progname = "mpd";
 
@@ -230,7 +229,6 @@ HttpdOutput::OnAccept(int fd, const sockaddr &address,
 	}
 #else
 	(void)address;
-	(void)address_length;
 #endif	/* HAVE_WRAP */
 
 	const ScopeLock protect(mutex);

test/run_resolver.cxx

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "net/Resolver.hxx"
+#include "net/SocketAddress.hxx"
 #include "util/Error.hxx"
 #include "Log.hxx"
 
@@ -50,7 +51,7 @@ int main(int argc, char **argv)
 	}
 
 	for (const struct addrinfo *i = ai; i != NULL; i = i->ai_next) {
-		const auto s = sockaddr_to_string(i->ai_addr, i->ai_addrlen);
+		const auto s = sockaddr_to_string({i->ai_addr, i->ai_addrlen});
 		printf("%s\n", s.c_str());
 	}