io: add QIOChannelSocket class

Implement a QIOChannel subclass that supports sockets I/O.
The implementation is able to manage a single socket file
descriptor, whether a TCP/UNIX listener, TCP/UNIX connection,
or a UDP datagram. It provides APIs which can listen and
connect either asynchronously or synchronously. Since there
is no asynchronous DNS lookup API available, it uses the
QIOTask helper for spawning a background thread to ensure
non-blocking operation.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

1 files changed, 244 insertions, 0 deletions

diff --git a/include/io/channel-socket.h b/include/io/channel-socket.h
new file mode 100644
index 0000000000..0719757b0f
--- /dev/null
+++ b/include/io/channel-socket.h
@@ -0,0 +1,244 @@
+/*
+ * QEMU I/O channels sockets driver
+ *
+ * Copyright (c) 2015 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef QIO_CHANNEL_SOCKET_H__
+#define QIO_CHANNEL_SOCKET_H__
+
+#include "io/channel.h"
+#include "io/task.h"
+#include "qemu/sockets.h"
+
+#define TYPE_QIO_CHANNEL_SOCKET "qio-channel-socket"
+#define QIO_CHANNEL_SOCKET(obj)                                     \
+    OBJECT_CHECK(QIOChannelSocket, (obj), TYPE_QIO_CHANNEL_SOCKET)
+
+typedef struct QIOChannelSocket QIOChannelSocket;
+
+/**
+ * QIOChannelSocket:
+ *
+ * The QIOChannelSocket class provides a channel implementation
+ * that can transport data over a UNIX socket or TCP socket.
+ * Beyond the core channel API, it also provides functionality
+ * for accepting client connections, tuning some socket
+ * parameters and getting socket address strings.
+ */
+
+struct QIOChannelSocket {
+    QIOChannel parent;
+    int fd;
+    struct sockaddr_storage localAddr;
+    socklen_t localAddrLen;
+    struct sockaddr_storage remoteAddr;
+    socklen_t remoteAddrLen;
+};
+
+
+/**
+ * qio_channel_socket_new:
+ *
+ * Create a channel for performing I/O on a socket
+ * connection, that is initially closed. After
+ * creating the socket, it must be setup as a client
+ * connection or server.
+ *
+ * Returns: the socket channel object
+ */
+QIOChannelSocket *
+qio_channel_socket_new(void);
+
+/**
+ * qio_channel_socket_new_fd:
+ * @fd: the socket file descriptor
+ * @errp: pointer to an uninitialized error object
+ *
+ * Create a channel for performing I/O on the socket
+ * connection represented by the file descriptor @fd.
+ *
+ * Returns: the socket channel object, or NULL on error
+ */
+QIOChannelSocket *
+qio_channel_socket_new_fd(int fd,
+                          Error **errp);
+
+
+/**
+ * qio_channel_socket_connect_sync:
+ * @ioc: the socket channel object
+ * @addr: the address to connect to
+ * @errp: pointer to an uninitialized error object
+ *
+ * Attempt to connect to the address @addr. This method
+ * will run in the foreground so the caller will not regain
+ * execution control until the connection is established or
+ * an error occurs.
+ */
+int qio_channel_socket_connect_sync(QIOChannelSocket *ioc,
+                                    SocketAddress *addr,
+                                    Error **errp);
+
+/**
+ * qio_channel_socket_connect_async:
+ * @ioc: the socket channel object
+ * @addr: the address to connect to
+ * @callback: the function to invoke on completion
+ * @opaque: user data to pass to @callback
+ * @destroy: the function to free @opaque
+ *
+ * Attempt to connect to the address @addr. This method
+ * will run in the background so the caller will regain
+ * execution control immediately. The function @callback
+ * will be invoked on completion or failure.
+ */
+void qio_channel_socket_connect_async(QIOChannelSocket *ioc,
+                                      SocketAddress *addr,
+                                      QIOTaskFunc callback,
+                                      gpointer opaque,
+                                      GDestroyNotify destroy);
+
+
+/**
+ * qio_channel_socket_listen_sync:
+ * @ioc: the socket channel object
+ * @addr: the address to listen to
+ * @errp: pointer to an uninitialized error object
+ *
+ * Attempt to listen to the address @addr. This method
+ * will run in the foreground so the caller will not regain
+ * execution control until the connection is established or
+ * an error occurs.
+ */
+int qio_channel_socket_listen_sync(QIOChannelSocket *ioc,
+                                   SocketAddress *addr,
+                                   Error **errp);
+
+/**
+ * qio_channel_socket_listen_async:
+ * @ioc: the socket channel object
+ * @addr: the address to listen to
+ * @callback: the function to invoke on completion
+ * @opaque: user data to pass to @callback
+ * @destroy: the function to free @opaque
+ *
+ * Attempt to listen to the address @addr. This method
+ * will run in the background so the caller will regain
+ * execution control immediately. The function @callback
+ * will be invoked on completion or failure.
+ */
+void qio_channel_socket_listen_async(QIOChannelSocket *ioc,
+                                     SocketAddress *addr,
+                                     QIOTaskFunc callback,
+                                     gpointer opaque,
+                                     GDestroyNotify destroy);
+
+
+/**
+ * qio_channel_socket_dgram_sync:
+ * @ioc: the socket channel object
+ * @localAddr: the address to local bind address
+ * @remoteAddr: the address to remote peer address
+ * @errp: pointer to an uninitialized error object
+ *
+ * Attempt to initialize a datagram socket bound to
+ * @localAddr and communicating with peer @remoteAddr.
+ * This method will run in the foreground so the caller
+ * will not regain execution control until the socket
+ * is established or an error occurs.
+ */
+int qio_channel_socket_dgram_sync(QIOChannelSocket *ioc,
+                                  SocketAddress *localAddr,
+                                  SocketAddress *remoteAddr,
+                                  Error **errp);
+
+/**
+ * qio_channel_socket_dgram_async:
+ * @ioc: the socket channel object
+ * @localAddr: the address to local bind address
+ * @remoteAddr: the address to remote peer address
+ * @callback: the function to invoke on completion
+ * @opaque: user data to pass to @callback
+ * @destroy: the function to free @opaque
+ *
+ * Attempt to initialize a datagram socket bound to
+ * @localAddr and communicating with peer @remoteAddr.
+ * This method will run in the background so the caller
+ * will regain execution control immediately. The function
+ * @callback will be invoked on completion or failure.
+ */
+void qio_channel_socket_dgram_async(QIOChannelSocket *ioc,
+                                    SocketAddress *localAddr,
+                                    SocketAddress *remoteAddr,
+                                    QIOTaskFunc callback,
+                                    gpointer opaque,
+                                    GDestroyNotify destroy);
+
+
+/**
+ * qio_channel_socket_get_local_address:
+ * @ioc: the socket channel object
+ * @errp: pointer to an uninitialized error object
+ *
+ * Get the string representation of the local socket
+ * address. A pointer to the allocated address information
+ * struct will be returned, which the caller is required to
+ * release with a call qapi_free_SocketAddress when no
+ * longer required.
+ *
+ * Returns: 0 on success, -1 on error
+ */
+SocketAddress *
+qio_channel_socket_get_local_address(QIOChannelSocket *ioc,
+                                     Error **errp);
+
+/**
+ * qio_channel_socket_get_remote_address:
+ * @ioc: the socket channel object
+ * @errp: pointer to an uninitialized error object
+ *
+ * Get the string representation of the local socket
+ * address. A pointer to the allocated address information
+ * struct will be returned, which the caller is required to
+ * release with a call qapi_free_SocketAddress when no
+ * longer required.
+ *
+ * Returns: the socket address struct, or NULL on error
+ */
+SocketAddress *
+qio_channel_socket_get_remote_address(QIOChannelSocket *ioc,
+                                      Error **errp);
+
+
+/**
+ * qio_channel_socket_accept:
+ * @ioc: the socket channel object
+ * @errp: pointer to an uninitialized error object
+ *
+ * If the socket represents a server, then this accepts
+ * a new client connection. The returned channel will
+ * represent the connected client socket.
+ *
+ * Returns: the new client channel, or NULL on error
+ */
+QIOChannelSocket *
+qio_channel_socket_accept(QIOChannelSocket *ioc,
+                          Error **errp);
+
+
+#endif /* QIO_CHANNEL_SOCKET_H__ */