1 files changed, 438 insertions, 0 deletions
diff --git a/src/event/ServerSocket.cxx b/src/event/ServerSocket.cxx
new file mode 100644
index 00000000..119bfe1d
--- /dev/null
+++ b/src/event/ServerSocket.cxx
@@ -0,0 +1,438 @@
+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU 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 "config.h"
+
+#ifdef HAVE_STRUCT_UCRED
+#define _GNU_SOURCE 1
+#endif
+
+#include "ServerSocket.hxx"
+#include "SocketUtil.hxx"
+#include "SocketError.hxx"
+#include "event/SocketMonitor.hxx"
+#include "resolver.h"
+#include "fd_util.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#ifdef WIN32
+#include <ws2tcpip.h>
+#include <winsock.h>
+#else
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <netdb.h>
+#endif
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "listen"
+
+#define DEFAULT_PORT	6600
+
+class OneServerSocket final : private SocketMonitor {
+	ServerSocket &parent;
+
+	const unsigned serial;
+
+	char *path;
+
+	size_t address_length;
+	struct sockaddr *address;
+
+public:
+	OneServerSocket(EventLoop &_loop, ServerSocket &_parent,
+			unsigned _serial,
+			const struct sockaddr *_address,
+			size_t _address_length)
+		:SocketMonitor(_loop),
+		 parent(_parent), serial(_serial),
+		 path(nullptr),
+		 address_length(_address_length),
+		 address((sockaddr *)g_memdup(_address, _address_length))
+	{
+		assert(_address != nullptr);
+		assert(_address_length > 0);
+	}
+
+	OneServerSocket(const OneServerSocket &other) = delete;
+	OneServerSocket &operator=(const OneServerSocket &other) = delete;
+
+	~OneServerSocket() {
+		g_free(path);
+		g_free(address);
+	}
+
+	unsigned GetSerial() const {
+		return serial;
+	}
+
+	void SetPath(const char *_path) {
+		assert(path == nullptr);
+
+		path = g_strdup(_path);
+	}
+
+	bool Open(GError **error_r);
+
+	using SocketMonitor::IsDefined;
+	using SocketMonitor::Close;
+
+	char *ToString() const;
+
+	void SetFD(int _fd) {
+		SocketMonitor::Open(_fd);
+		SocketMonitor::ScheduleRead();
+	}
+
+	void Accept();
+
+private:
+	virtual bool OnSocketReady(unsigned flags) override;
+};
+
+static GQuark
+server_socket_quark(void)
+{
+	return g_quark_from_static_string("server_socket");
+}
+
+/**
+ * Wraper for sockaddr_to_string() which never fails.
+ */
+char *
+OneServerSocket::ToString() const
+{
+	char *p = sockaddr_to_string(address, address_length, nullptr);
+	if (p == nullptr)
+		p = g_strdup("[unknown]");
+	return p;
+}
+
+static int
+get_remote_uid(int fd)
+{
+#ifdef HAVE_STRUCT_UCRED
+	struct ucred cred;
+	socklen_t len = sizeof (cred);
+
+	if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cred, &len) < 0)
+		return 0;
+
+	return cred.uid;
+#else
+#ifdef HAVE_GETPEEREID
+	uid_t euid;
+	gid_t egid;
+
+	if (getpeereid(fd, &euid, &egid) == 0)
+		return euid;
+#else
+	(void)fd;
+#endif
+	return -1;
+#endif
+}
+
+inline void
+OneServerSocket::Accept()
+{
+	struct sockaddr_storage peer_address;
+	size_t peer_address_length = sizeof(peer_address);
+	int peer_fd =
+		accept_cloexec_nonblock(Get(), (struct sockaddr*)&peer_address,
+					&peer_address_length);
+	if (peer_fd < 0) {
+		const SocketErrorMessage msg;
+		g_warning("accept() failed: %s", (const char *)msg);
+		return;
+	}
+
+	if (socket_keepalive(peer_fd)) {
+		const SocketErrorMessage msg;
+		g_warning("Could not set TCP keepalive option: %s",
+			  (const char *)msg);
+	}
+
+	parent.OnAccept(peer_fd,
+			(const sockaddr &)peer_address,
+			peer_address_length, get_remote_uid(peer_fd));
+}
+
+bool
+OneServerSocket::OnSocketReady(gcc_unused unsigned flags)
+{
+	Accept();
+	return true;
+}
+
+inline bool
+OneServerSocket::Open(GError **error_r)
+{
+	assert(!IsDefined());
+
+	int _fd = socket_bind_listen(address->sa_family,
+				     SOCK_STREAM, 0,
+				     address, address_length, 5,
+				     error_r);
+	if (_fd < 0)
+		return false;
+
+	/* allow everybody to connect */
+
+	if (path != nullptr)
+		chmod(path, 0666);
+
+	/* register in the GLib main loop */
+
+	SetFD(_fd);
+
+	return true;
+}
+
+ServerSocket::ServerSocket(EventLoop &_loop)
+	:loop(_loop), next_serial(1) {}
+
+/* this is just here to allow the OneServerSocket forward
+   declaration */
+ServerSocket::~ServerSocket() {}
+
+bool
+ServerSocket::Open(GError **error_r)
+{
+	OneServerSocket *good = nullptr, *bad = nullptr;
+	GError *last_error = nullptr;
+
+	for (auto &i : sockets) {
+		assert(i.GetSerial() > 0);
+		assert(good == nullptr || i.GetSerial() <= good->GetSerial());
+
+		if (bad != nullptr && i.GetSerial() != bad->GetSerial()) {
+			Close();
+			g_propagate_error(error_r, last_error);
+			return false;
+		}
+
+		GError *error = nullptr;
+		if (!i.Open(&error)) {
+			if (good != nullptr && good->GetSerial() == i.GetSerial()) {
+				char *address_string = i.ToString();
+				char *good_string = good->ToString();
+				g_warning("bind to '%s' failed: %s "
+					  "(continuing anyway, because "
+					  "binding to '%s' succeeded)",
+					  address_string, error->message,
+					  good_string);
+				g_free(address_string);
+				g_free(good_string);
+				g_error_free(error);
+			} else if (bad == nullptr) {
+				bad = &i;
+
+				char *address_string = i.ToString();
+				g_propagate_prefixed_error(&last_error, error,
+							   "Failed to bind to '%s': ",
+							   address_string);
+				g_free(address_string);
+			} else
+				g_error_free(error);
+			continue;
+		}
+
+		/* mark this socket as "good", and clear previous
+		   errors */
+
+		good = &i;
+
+		if (bad != nullptr) {
+			bad = nullptr;
+			g_error_free(last_error);
+			last_error = nullptr;
+		}
+	}
+
+	if (bad != nullptr) {
+		Close();
+		g_propagate_error(error_r, last_error);
+		return false;
+	}
+
+	return true;
+}
+
+void
+ServerSocket::Close()
+{
+	for (auto &i : sockets)
+		if (i.IsDefined())
+			i.Close();
+}
+
+OneServerSocket &
+ServerSocket::AddAddress(const sockaddr &address, size_t address_length)
+{
+	sockets.emplace_front(loop, *this, next_serial,
+			      &address, address_length);
+
+	return sockets.front();
+}
+
+bool
+ServerSocket::AddFD(int fd, GError **error_r)
+{
+	assert(fd >= 0);
+
+	struct sockaddr_storage address;
+	socklen_t address_length = sizeof(address);
+	if (getsockname(fd, (struct sockaddr *)&address,
+			&address_length) < 0) {
+		SetSocketError(error_r);
+		g_prefix_error(error_r, "Failed to get socket address");
+		return false;
+	}
+
+	OneServerSocket &s = AddAddress((const sockaddr &)address,
+					address_length);
+	s.SetFD(fd);
+
+	return true;
+}
+
+#ifdef HAVE_TCP
+
+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));
+}
+
+#ifdef HAVE_IPV6
+inline void
+ServerSocket::AddPortIPv6(unsigned port)
+{
+	struct sockaddr_in6 sin;
+	memset(&sin, 0, sizeof(sin));
+	sin.sin6_port = htons(port);
+	sin.sin6_family = AF_INET6;
+
+	AddAddress((const sockaddr &)sin, sizeof(sin));
+}
+#endif /* HAVE_IPV6 */
+
+#endif /* HAVE_TCP */
+
+bool
+ServerSocket::AddPort(unsigned port, GError **error_r)
+{
+#ifdef HAVE_TCP
+	if (port == 0 || port > 0xffff) {
+		g_set_error(error_r, server_socket_quark(), 0,
+			    "Invalid TCP port");
+		return false;
+	}
+
+#ifdef HAVE_IPV6
+	AddPortIPv6(port);
+#endif
+	AddPortIPv4(port);
+
+	++next_serial;
+
+	return true;
+#else /* HAVE_TCP */
+	(void)port;
+
+	g_set_error(error_r, server_socket_quark(), 0,
+		    "TCP support is disabled");
+	return false;
+#endif /* HAVE_TCP */
+}
+
+bool
+ServerSocket::AddHost(const char *hostname, unsigned port, GError **error_r)
+{
+#ifdef HAVE_TCP
+	struct addrinfo *ai = resolve_host_port(hostname, port,
+						AI_PASSIVE, SOCK_STREAM,
+						error_r);
+	if (ai == nullptr)
+		return false;
+
+	for (const struct addrinfo *i = ai; i != nullptr; i = i->ai_next)
+		AddAddress(*i->ai_addr, i->ai_addrlen);
+
+	freeaddrinfo(ai);
+
+	++next_serial;
+
+	return true;
+#else /* HAVE_TCP */
+	(void)hostname;
+	(void)port;
+
+	g_set_error(error_r, server_socket_quark(), 0,
+		    "TCP support is disabled");
+	return false;
+#endif /* HAVE_TCP */
+}
+
+bool
+ServerSocket::AddPath(const char *path, GError **error_r)
+{
+#ifdef HAVE_UN
+	struct sockaddr_un s_un;
+
+	size_t path_length = strlen(path);
+	if (path_length >= sizeof(s_un.sun_path)) {
+		g_set_error(error_r, server_socket_quark(), 0,
+			    "UNIX socket path is too long");
+		return false;
+	}
+
+	unlink(path);
+
+	s_un.sun_family = AF_UNIX;
+	memcpy(s_un.sun_path, path, path_length + 1);
+
+	OneServerSocket &s = AddAddress((const sockaddr &)s_un, sizeof(s_un));
+	s.SetPath(path);
+
+	return true;
+#else /* !HAVE_UN */
+	(void)path;
+
+	g_set_error(error_r, server_socket_quark(), 0,
+		    "UNIX domain socket support is disabled");
+	return false;
+#endif /* !HAVE_UN */
+}
+