net/StaticSocketAdress: new class wrapping struct sockaddr_storage

Makefile.am

@@ -421,6 +421,7 @@ libthread_a_SOURCES = \
 
 libnet_a_SOURCES = \
 	src/net/Resolver.cxx src/net/Resolver.hxx \
+	src/net/StaticSocketAddress.cxx src/net/StaticSocketAddress.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/event/ServerSocket.cxx

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "ServerSocket.hxx"
+#include "net/StaticSocketAddress.hxx"
 #include "net/SocketAddress.hxx"
 #include "net/SocketUtil.hxx"
 #include "net/SocketError.hxx"
@@ -148,10 +149,10 @@ get_remote_uid(int fd)
 inline void
 OneServerSocket::Accept()
 {
-	struct sockaddr_storage peer_address;
+	StaticSocketAddress peer_address;
 	size_t peer_address_length = sizeof(peer_address);
 	int peer_fd =
-		accept_cloexec_nonblock(Get(), (struct sockaddr*)&peer_address,
+		accept_cloexec_nonblock(Get(), peer_address,
 					&peer_address_length);
 	if (peer_fd < 0) {
 		const SocketErrorMessage msg;
@@ -160,6 +161,8 @@ OneServerSocket::Accept()
 		return;
 	}
 
+	peer_address.SetSize(peer_address_length);
+
 	if (socket_keepalive(peer_fd)) {
 		const SocketErrorMessage msg;
 		FormatError(server_socket_domain,
@@ -167,8 +170,7 @@ OneServerSocket::Accept()
 			    (const char *)msg);
 	}
 
-	parent.OnAccept(peer_fd,
-			{ (const sockaddr *)&peer_address, socklen_t(peer_address_length) },
+	parent.OnAccept(peer_fd, peer_address,
 			get_remote_uid(peer_fd));
 }
 
@@ -293,16 +295,18 @@ ServerSocket::AddFD(int fd, Error &error)
 {
 	assert(fd >= 0);
 
-	struct sockaddr_storage address;
+	StaticSocketAddress address;
 	socklen_t address_length = sizeof(address);
-	if (getsockname(fd, (struct sockaddr *)&address,
+	if (getsockname(fd, address,
 			&address_length) < 0) {
 		SetSocketError(error);
 		error.AddPrefix("Failed to get socket address: ");
 		return false;
 	}
 
-	OneServerSocket &s = AddAddress({(const sockaddr *)&address, address_length});
+	address.SetSize(address_length);
+
+	OneServerSocket &s = AddAddress(address);
 	s.SetFD(fd);
 
 	return true;

src/net/StaticSocketAddress.cxx

@@ -0,0 +1,78 @@
+/*
+ * 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 "StaticSocketAddress.hxx"
+
+#include <algorithm>
+
+#include <assert.h>
+#include <string.h>
+
+#ifdef WIN32
+#include <ws2tcpip.h>
+#else
+#include <sys/un.h>
+#include <sys/socket.h>
+#endif
+
+StaticSocketAddress &
+StaticSocketAddress::operator=(SocketAddress other)
+{
+	size = std::min(size_t(other.GetSize()), GetCapacity());
+	memcpy(&address, other.GetAddress(), size);
+	return *this;
+}
+
+bool
+StaticSocketAddress::operator==(const StaticSocketAddress &other) const
+{
+	return size == other.size &&
+		memcmp(&address, &other.address, size) == 0;
+}
+
+#ifdef HAVE_UN
+
+void
+StaticSocketAddress::SetLocal(const char *path)
+{
+	auto &sun = reinterpret_cast<struct sockaddr_un &>(address);
+
+	const size_t path_length = strlen(path);
+
+	// TODO: make this a runtime check
+	assert(path_length < sizeof(sun.sun_path));
+
+	sun.sun_family = AF_LOCAL;
+	memcpy(sun.sun_path, path, path_length + 1);
+
+	/* note: Bionic doesn't provide SUN_LEN() */
+	size = SUN_LEN(&sun);
+}
+
+#endif

src/net/StaticSocketAddress.hxx

@@ -0,0 +1,114 @@
+/*
+ * 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 STATIC_SOCKET_ADDRESS_HXX
+#define STATIC_SOCKET_ADDRESS_HXX
+
+#include "SocketAddress.hxx"
+#include "Compiler.h"
+
+#include <assert.h>
+#include <stdint.h>
+
+#ifdef WIN32
+#include <winsock2.h>
+#else
+#include <sys/socket.h>
+#endif
+
+struct ifaddrs;
+
+/**
+ * An OO wrapper for struct sockaddr_storage.
+ */
+class StaticSocketAddress {
+	size_t size;
+	struct sockaddr_storage address;
+
+public:
+	StaticSocketAddress() = default;
+
+	StaticSocketAddress &operator=(SocketAddress other);
+
+	operator SocketAddress() const {
+		return SocketAddress(reinterpret_cast<const struct sockaddr *>(&address),
+				     size);
+	}
+
+#ifdef HAVE_UN
+	/**
+	 * Make this a "local" address (UNIX domain socket).
+	 */
+	void SetLocal(const char *path);
+#endif
+
+	operator struct sockaddr *() {
+		return reinterpret_cast<struct sockaddr *>(&address);
+	}
+
+	operator const struct sockaddr *() const {
+		return reinterpret_cast<const struct sockaddr *>(&address);
+	}
+
+	constexpr size_t GetCapacity() const {
+		return sizeof(address);
+	}
+
+	size_t GetSize() const {
+		return size;
+	}
+
+	void SetSize(size_t _size) {
+		assert(_size > 0);
+		assert(_size <= sizeof(address));
+
+		size = _size;
+	}
+
+	int GetFamily() const {
+		return address.ss_family;
+	}
+
+	bool IsDefined() const {
+		return GetFamily() != AF_UNSPEC;
+	}
+
+	void Clear() {
+		address.ss_family = AF_UNSPEC;
+	}
+
+	gcc_pure
+	bool operator==(const StaticSocketAddress &other) const;
+
+	bool operator!=(const StaticSocketAddress &other) const {
+		return !(*this == other);
+	}
+};
+
+#endif