Merge remote-tracking branch 'remotes/berrange/tags/pull-io-channel-base-2015-12-18-1' into staging

Merge I/O channels base classes

# gpg: Signature made Fri 18 Dec 2015 12:18:38 GMT using RSA key ID 15104FDF
# gpg: Good signature from "Daniel P. Berrange <dan@berrange.com>"
# gpg:                 aka "Daniel P. Berrange <berrange@redhat.com>"

* remotes/berrange/tags/pull-io-channel-base-2015-12-18-1:
  io: add QIOChannelBuffer class
  io: add QIOChannelCommand class
  io: add QIOChannelWebsock class
  io: add QIOChannelTLS class
  io: add QIOChannelFile class
  io: add QIOChannelSocket class
  io: add QIOTask class for async operations
  io: add helper module for creating watches on FDs
  io: add abstract QIOChannel classes
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

MAINTAINERS

@@ -1243,6 +1243,13 @@ S: Odd fixes
 F: util/buffer.c
 F: include/qemu/buffer.h
 
+I/O Channels
+M: Daniel P. Berrange <berrange@redhat.com>
+S: Maintained
+F: io/
+F: include/io/
+F: tests/test-io-*
+
 Usermode Emulation
 ------------------
 Overall

Makefile

@@ -159,6 +159,7 @@ dummy := $(call unnest-vars,, \
                 crypto-obj-y \
                 crypto-aes-obj-y \
                 qom-obj-y \
+                io-obj-y \
                 common-obj-y \
                 common-obj-m)
 
@@ -178,6 +179,7 @@ SOFTMMU_SUBDIR_RULES=$(filter %-softmmu,$(SUBDIR_RULES))
 
 $(SOFTMMU_SUBDIR_RULES): $(block-obj-y)
 $(SOFTMMU_SUBDIR_RULES): $(crypto-obj-y)
+$(SOFTMMU_SUBDIR_RULES): $(io-obj-y)
 $(SOFTMMU_SUBDIR_RULES): config-all-devices.mak
 
 subdir-%:

Makefile.objs

@@ -28,6 +28,11 @@ crypto-aes-obj-y = crypto/
 
 qom-obj-y = qom/
 
+#######################################################################
+# io-obj-y is code used by both qemu system emulation and qemu-img
+
+io-obj-y = io/
+
 ######################################################################
 # Target independent part of system emulation. The long term path is to
 # suppress *all* target specific code in case of system emulation, i.e. a

Makefile.target

@@ -176,6 +176,7 @@ dummy := $(call unnest-vars,.., \
                crypto-obj-y \
                crypto-aes-obj-y \
                qom-obj-y \
+               io-obj-y \
                common-obj-y \
                common-obj-m)
 target-obj-y := $(target-obj-y-save)
@@ -185,6 +186,7 @@ all-obj-y += $(qom-obj-y)
 all-obj-$(CONFIG_SOFTMMU) += $(block-obj-y)
 all-obj-$(CONFIG_USER_ONLY) += $(crypto-aes-obj-y)
 all-obj-$(CONFIG_SOFTMMU) += $(crypto-obj-y)
+all-obj-$(CONFIG_SOFTMMU) += $(io-obj-y)
 
 $(QEMU_PROG_BUILD): config-devices.mak
 

configure

@@ -2426,6 +2426,14 @@ else
 fi
 
 
+##########################################
+# getifaddrs (for tests/test-io-channel-socket )
+
+have_ifaddrs_h=yes
+if ! check_include "ifaddrs.h" ; then
+  have_ifaddrs_h=no
+fi
+
 ##########################################
 # VTE probe
 
@@ -5137,6 +5145,9 @@ fi
 if test "$tasn1" = "yes" ; then
   echo "CONFIG_TASN1=y" >> $config_host_mak
 fi
+if test "$have_ifaddrs_h" = "yes" ; then
+    echo "HAVE_IFADDRS_H=y" >> $config_host_mak
+fi
 if test "$vte" = "yes" ; then
   echo "CONFIG_VTE=y" >> $config_host_mak
   echo "VTE_CFLAGS=$vte_cflags" >> $config_host_mak

include/io/channel-buffer.h

+/*
+ * QEMU I/O channels memory buffer 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_BUFFER_H__
+#define QIO_CHANNEL_BUFFER_H__
+
+#include "io/channel.h"
+
+#define TYPE_QIO_CHANNEL_BUFFER "qio-channel-buffer"
+#define QIO_CHANNEL_BUFFER(obj)                                     \
+    OBJECT_CHECK(QIOChannelBuffer, (obj), TYPE_QIO_CHANNEL_BUFFER)
+
+typedef struct QIOChannelBuffer QIOChannelBuffer;
+
+/**
+ * QIOChannelBuffer:
+ *
+ * The QIOChannelBuffer object provides a channel implementation
+ * that is able to perform I/O to/from a memory buffer.
+ *
+ */
+
+struct QIOChannelBuffer {
+    QIOChannel parent;
+    size_t capacity; /* Total allocated memory */
+    size_t usage;    /* Current size of data */
+    size_t offset;   /* Offset for future I/O ops */
+    char *data;
+};
+
+
+/**
+ * qio_channel_buffer_new:
+ * @capacity: the initial buffer capacity to allocate
+ *
+ * Allocate a new buffer which is initially empty
+ *
+ * Returns: the new channel object
+ */
+QIOChannelBuffer *
+qio_channel_buffer_new(size_t capacity);
+
+#endif /* QIO_CHANNEL_BUFFER_H__ */

include/io/channel-command.h

+/*
+ * QEMU I/O channels external command 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_COMMAND_H__
+#define QIO_CHANNEL_COMMAND_H__
+
+#include "io/channel.h"
+
+#define TYPE_QIO_CHANNEL_COMMAND "qio-channel-command"
+#define QIO_CHANNEL_COMMAND(obj)                                     \
+    OBJECT_CHECK(QIOChannelCommand, (obj), TYPE_QIO_CHANNEL_COMMAND)
+
+typedef struct QIOChannelCommand QIOChannelCommand;
+
+
+/**
+ * QIOChannelCommand:
+ *
+ * The QIOChannelCommand class provides a channel implementation
+ * that can transport data with an externally running command
+ * via its stdio streams.
+ */
+
+struct QIOChannelCommand {
+    QIOChannel parent;
+    int writefd;
+    int readfd;
+    pid_t pid;
+};
+
+
+/**
+ * qio_channel_command_new_pid:
+ * @writefd: the FD connected to the command's stdin
+ * @readfd: the FD connected to the command's stdout
+ * @pid: the PID of the running child command
+ * @errp: pointer to an uninitialized error object
+ *
+ * Create a channel for performing I/O with the
+ * previously spawned command identified by @pid.
+ * The two file descriptors provide the connection
+ * to command's stdio streams, either one or which
+ * may be -1 to indicate that stream is not open.
+ *
+ * The channel will take ownership of the process
+ * @pid and will kill it when closing the channel.
+ * Similarly it will take responsibility for
+ * closing the file descriptors @writefd and @readfd.
+ *
+ * Returns: the command channel object, or NULL on error
+ */
+QIOChannelCommand *
+qio_channel_command_new_pid(int writefd,
+                            int readfd,
+                            pid_t pid);
+
+/**
+ * qio_channel_command_new_spawn:
+ * @argv: the NULL terminated list of command arguments
+ * @flags: the I/O mode, one of O_RDONLY, O_WRONLY, O_RDWR
+ * @errp: pointer to an uninitialized error object
+ *
+ * Create a channel for performing I/O with the
+ * command to be spawned with arguments @argv.
+ *
+ * Returns: the command channel object, or NULL on error
+ */
+QIOChannelCommand *
+qio_channel_command_new_spawn(const char *const argv[],
+                              int flags,
+                              Error **errp);
+
+
+#endif /* QIO_CHANNEL_COMMAND_H__ */

include/io/channel-file.h

+/*
+ * QEMU I/O channels files 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_FILE_H__
+#define QIO_CHANNEL_FILE_H__
+
+#include "io/channel.h"
+
+#define TYPE_QIO_CHANNEL_FILE "qio-channel-file"
+#define QIO_CHANNEL_FILE(obj)                                     \
+    OBJECT_CHECK(QIOChannelFile, (obj), TYPE_QIO_CHANNEL_FILE)
+
+typedef struct QIOChannelFile QIOChannelFile;
+
+/**
+ * QIOChannelFile:
+ *
+ * The QIOChannelFile object provides a channel implementation
+ * that is able to perform I/O on block devices, character
+ * devices, FIFOs, pipes and plain files. While it is technically
+ * able to work on sockets too on the UNIX platform, this is not
+ * portable to Windows and lacks some extra sockets specific
+ * functionality. So the QIOChannelSocket object is recommended
+ * for that use case.
+ *
+ */
+
+struct QIOChannelFile {
+    QIOChannel parent;
+    int fd;
+};
+
+
+/**
+ * qio_channel_file_new_fd:
+ * @fd: the file descriptor
+ *
+ * Create a new IO channel object for a file represented
+ * by the @fd parameter. @fd can be associated with a
+ * block device, character device, fifo, pipe, or a
+ * regular file. For sockets, the QIOChannelSocket class
+ * should be used instead, as this provides greater
+ * functionality and cross platform portability.
+ *
+ * The channel will own the passed in file descriptor
+ * and will take responsibility for closing it, so the
+ * caller must not close it. If appropriate the caller
+ * should dup() its FD before opening the channel.
+ *
+ * Returns: the new channel object
+ */
+QIOChannelFile *
+qio_channel_file_new_fd(int fd);
+
+/**
+ * qio_channel_file_new_path:
+ * @fd: the file descriptor
+ * @flags: the open flags (O_RDONLY|O_WRONLY|O_RDWR, etc)
+ * @mode: the file creation mode if O_WRONLY is set in @flags
+ * @errp: pointer to initialized error object
+ *
+ * Create a new IO channel object for a file represented
+ * by the @path parameter. @path can point to any
+ * type of file on which sequential I/O can be
+ * performed, whether it be a plain file, character
+ * device or block device.
+ *
+ * Returns: the new channel object
+ */
+QIOChannelFile *
+qio_channel_file_new_path(const char *path,
+                          int flags,
+                          mode_t mode,
+                          Error **errp);
+
+#endif /* QIO_CHANNEL_FILE_H__ */

include/io/channel-socket.h

+/*
+ * 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__ */

include/io/channel-tls.h

+/*
+ * QEMU I/O channels TLS 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_TLS_H__
+#define QIO_CHANNEL_TLS_H__
+
+#include "io/channel.h"
+#include "io/task.h"
+#include "crypto/tlssession.h"
+
+#define TYPE_QIO_CHANNEL_TLS "qio-channel-tls"
+#define QIO_CHANNEL_TLS(obj)                                     \
+    OBJECT_CHECK(QIOChannelTLS, (obj), TYPE_QIO_CHANNEL_TLS)
+
+typedef struct QIOChannelTLS QIOChannelTLS;
+
+/**
+ * QIOChannelTLS
+ *
+ * The QIOChannelTLS class provides a channel wrapper which
+ * can transparently run the TLS encryption protocol. It is
+ * usually used over a TCP socket, but there is actually no
+ * technical restriction on which type of master channel is
+ * used as the transport.
+ *
+ * This channel object is capable of running as either a
+ * TLS server or TLS client.
+ */
+
+struct QIOChannelTLS {
+    QIOChannel parent;
+    QIOChannel *master;
+    QCryptoTLSSession *session;
+};
+
+/**
+ * qio_channel_tls_new_server:
+ * @master: the underlying channel object
+ * @creds: the credentials to use for TLS handshake
+ * @aclname: the access control list for validating clients
+ * @errp: pointer to an uninitialized error object
+ *
+ * Create a new TLS channel that runs the server side of
+ * a TLS session. The TLS session handshake will use the
+ * credentials provided in @creds. If the @aclname parameter
+ * is non-NULL, then the client will have to provide
+ * credentials (ie a x509 client certificate) which will
+ * then be validated against the ACL.
+ *
+ * After creating the channel, it is mandatory to call
+ * the qio_channel_tls_handshake() method before attempting
+ * todo any I/O on the channel.
+ *
+ * Once the handshake has completed, all I/O should be done
+ * via the new TLS channel object and not the original
+ * master channel
+ *
+ * Returns: the new TLS channel object, or NULL
+ */
+QIOChannelTLS *
+qio_channel_tls_new_server(QIOChannel *master,
+                           QCryptoTLSCreds *creds,
+                           const char *aclname,
+                           Error **errp);
+
+/**
+ * qio_channel_tls_new_client:
+ * @master: the underlying channel object
+ * @creds: the credentials to use for TLS handshake
+ * @hostname: the user specified server hostname
+ * @errp: pointer to an uninitialized error object
+ *
+ * Create a new TLS channel that runs the client side of
+ * a TLS session. The TLS session handshake will use the
+ * credentials provided in @creds. The @hostname parameter
+ * should provide the user specified hostname of the server
+ * and will be validated against the server's credentials
+ * (ie CommonName of the x509 certificate)
+ *
+ * After creating the channel, it is mandatory to call
+ * the qio_channel_tls_handshake() method before attempting
+ * todo any I/O on the channel.
+ *
+ * Once the handshake has completed, all I/O should be done
+ * via the new TLS channel object and not the original
+ * master channel
+ *
+ * Returns: the new TLS channel object, or NULL
+ */
+QIOChannelTLS *
+qio_channel_tls_new_client(QIOChannel *master,
+                           QCryptoTLSCreds *creds,
+                           const char *hostname,
+                           Error **errp);
+
+/**
+ * qio_channel_tls_handshake:
+ * @ioc: the TLS channel object
+ * @func: the callback to invoke when completed
+ * @opaque: opaque data to pass to @func
+ * @destroy: optional callback to free @opaque
+ *
+ * Perform the TLS session handshake. This method
+ * will return immediately and the handshake will
+ * continue in the background, provided the main
+ * loop is running. When the handshake is complete,
+ * or fails, the @func callback will be invoked.
+ */
+void qio_channel_tls_handshake(QIOChannelTLS *ioc,
+                               QIOTaskFunc func,
+                               gpointer opaque,
+                               GDestroyNotify destroy);
+
+/**
+ * qio_channel_tls_get_session:
+ * @ioc: the TLS channel object
+ *
+ * Get the TLS session used by the channel.
+ *
+ * Returns: the TLS session
+ */
+QCryptoTLSSession *
+qio_channel_tls_get_session(QIOChannelTLS *ioc);
+
+#endif /* QIO_CHANNEL_TLS_H__ */

include/io/channel-watch.h

+/*
+ * QEMU I/O channels watch helper APIs
+ *
+ * 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_WATCH_H__
+#define QIO_CHANNEL_WATCH_H__
+
+#include "io/channel.h"
+
+/*
+ * This module provides helper functions that will be needed by
+ * the various QIOChannel implementations, for creating watches
+ * on file descriptors / sockets
+ */
+
+/**
+ * qio_channel_create_fd_watch:
+ * @ioc: the channel object
+ * @fd: the file descriptor
+ * @condition: the I/O condition
+ *
+ * Create a new main loop source that is able to
+ * monitor the file descriptor @fd for the
+ * I/O conditions in @condition. This is able
+ * monitor block devices, character devices,
+ * sockets, pipes but not plain files.
+ *
+ * Returns: the new main loop source
+ */
+GSource *qio_channel_create_fd_watch(QIOChannel *ioc,
+                                     int fd,
+                                     GIOCondition condition);
+
+/**
+ * qio_channel_create_fd_pair_watch:
+ * @ioc: the channel object
+ * @fdread: the file descriptor for reading
+ * @fdwrite: the file descriptor for writing
+ * @condition: the I/O condition
+ *
+ * Create a new main loop source that is able to
+ * monitor the pair of file descriptors @fdread
+ * and @fdwrite for the I/O conditions in @condition.
+ * This is intended for monitoring unidirectional
+ * file descriptors such as pipes, where a pair
+ * of descriptors is required for bidirectional
+ * I/O
+ *
+ * Returns: the new main loop source
+ */
+GSource *qio_channel_create_fd_pair_watch(QIOChannel *ioc,
+                                          int fdread,
+                                          int fdwrite,
+                                          GIOCondition condition);
+
+#endif /* QIO_CHANNEL_WATCH_H__ */

include/io/channel-websock.h

+/*
+ * QEMU I/O channels driver websockets
+ *
+ * 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_WEBSOCK_H__
+#define QIO_CHANNEL_WEBSOCK_H__
+
+#include "io/channel.h"
+#include "qemu/buffer.h"
+#include "io/task.h"
+
+#define TYPE_QIO_CHANNEL_WEBSOCK "qio-channel-websock"
+#define QIO_CHANNEL_WEBSOCK(obj)                                     \
+    OBJECT_CHECK(QIOChannelWebsock, (obj), TYPE_QIO_CHANNEL_WEBSOCK)
+
+typedef struct QIOChannelWebsock QIOChannelWebsock;
+typedef union QIOChannelWebsockMask QIOChannelWebsockMask;
+
+union QIOChannelWebsockMask {
+    char c[4];
+    uint32_t u;
+};
+
+/**
+ * QIOChannelWebsock
+ *
+ * The QIOChannelWebsock class provides a channel wrapper which
+ * can transparently run the HTTP websockets protocol. This is
+ * usually used over a TCP socket, but there is actually no
+ * technical restriction on which type of master channel is
+ * used as the transport.
+ *
+ * This channel object is currently only capable of running as
+ * a websocket server and is a pretty crude implementation
+ * of it, not supporting the full websockets protocol feature
+ * set. It is sufficient to use with a simple websockets
+ * client for encapsulating VNC for noVNC in-browser client.
+ */
+
+struct QIOChannelWebsock {
+    QIOChannel parent;
+    QIOChannel *master;
+    Buffer encinput;
+    Buffer encoutput;
+    Buffer rawinput;
+    Buffer rawoutput;
+    size_t payload_remain;
+    QIOChannelWebsockMask mask;
+    guint io_tag;
+    Error *io_err;
+    gboolean io_eof;
+};
+
+/**
+ * qio_channel_websock_new_server:
+ * @master: the underlying channel object
+ *
+ * Create a new websockets channel that runs the server
+ * side of the protocol.
+ *
+ * After creating the channel, it is mandatory to call
+ * the qio_channel_websock_handshake() method before attempting
+ * todo any I/O on the channel.
+ *
+ * Once the handshake has completed, all I/O should be done
+ * via the new websocket channel object and not the original
+ * master channel
+ *
+ * Returns: the new websockets channel object
+ */
+QIOChannelWebsock *
+qio_channel_websock_new_server(QIOChannel *master);
+
+/**
+ * qio_channel_websock_handshake:
+ * @ioc: the websocket channel object
+ * @func: the callback to invoke when completed
+ * @opaque: opaque data to pass to @func
+ * @destroy: optional callback to free @opaque
+ *
+ * Perform the websocket handshake. This method
+ * will return immediately and the handshake will
+ * continue in the background, provided the main
+ * loop is running. When the handshake is complete,
+ * or fails, the @func callback will be invoked.
+ */
+void qio_channel_websock_handshake(QIOChannelWebsock *ioc,
+                                   QIOTaskFunc func,
+                                   gpointer opaque,
+                                   GDestroyNotify destroy);
+
+#endif /* QIO_CHANNEL_WEBSOCK_H__ */

include/io/channel.h

+/*
+ * QEMU I/O channels
+ *
+ * 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_H__
+#define QIO_CHANNEL_H__
+
+#include "qemu-common.h"
+#include "qapi/error.h"
+#include "qom/object.h"
+
+#define TYPE_QIO_CHANNEL "qio-channel"
+#define QIO_CHANNEL(obj)                                    \
+    OBJECT_CHECK(QIOChannel, (obj), TYPE_QIO_CHANNEL)
+#define QIO_CHANNEL_CLASS(klass)                                    \
+    OBJECT_CLASS_CHECK(QIOChannelClass, klass, TYPE_QIO_CHANNEL)
+#define QIO_CHANNEL_GET_CLASS(obj)                                  \
+    OBJECT_GET_CLASS(QIOChannelClass, obj, TYPE_QIO_CHANNEL)
+
+typedef struct QIOChannel QIOChannel;
+typedef struct QIOChannelClass QIOChannelClass;
+
+#define QIO_CHANNEL_ERR_BLOCK -2
+
+typedef enum QIOChannelFeature QIOChannelFeature;
+
+enum QIOChannelFeature {
+    QIO_CHANNEL_FEATURE_FD_PASS  = (1 << 0),
+    QIO_CHANNEL_FEATURE_SHUTDOWN = (1 << 1),
+};
+
+
+typedef enum QIOChannelShutdown QIOChannelShutdown;
+
+enum QIOChannelShutdown {
+    QIO_CHANNEL_SHUTDOWN_BOTH,
+    QIO_CHANNEL_SHUTDOWN_READ,
+    QIO_CHANNEL_SHUTDOWN_WRITE,
+};
+
+typedef gboolean (*QIOChannelFunc)(QIOChannel *ioc,
+                                   GIOCondition condition,
+                                   gpointer data);
+
+/**
+ * QIOChannel:
+ *
+ * The QIOChannel defines the core API for a generic I/O channel
+ * class hierarchy. It is inspired by GIOChannel, but has the
+ * following differences
+ *
+ *  - Use QOM to properly support arbitrary subclassing
+ *  - Support use of iovecs for efficient I/O with multiple blocks
+ *  - None of the character set translation, binary data exclusively
+ *  - Direct support for QEMU Error object reporting
+ *  - File descriptor passing
+ *
+ * This base class is abstract so cannot be instantiated. There
+ * will be subclasses for dealing with sockets, files, and higher
+ * level protocols such as TLS, WebSocket, etc.
+ */
+
+struct QIOChannel {
+    Object parent;
+    unsigned int features; /* bitmask of QIOChannelFeatures */
+};
+
+/**
+ * QIOChannelClass:
+ *
+ * This class defines the contract that all subclasses
+ * must follow to provide specific channel implementations.
+ * The first five callbacks are mandatory to support, others
+ * provide additional optional features.
+ *
+ * Consult the corresponding public API docs for a description
+ * of the semantics of each callback
+ */
+struct QIOChannelClass {
+    ObjectClass parent;
+
+    /* Mandatory callbacks */
+    ssize_t (*io_writev)(QIOChannel *ioc,
+                         const struct iovec *iov,
+                         size_t niov,
+                         int *fds,
+                         size_t nfds,
+                         Error **errp);
+    ssize_t (*io_readv)(QIOChannel *ioc,
+                        const struct iovec *iov,
+                        size_t niov,
+                        int **fds,
+                        size_t *nfds,
+                        Error **errp);
+    int (*io_close)(QIOChannel *ioc,
+                    Error **errp);
+    GSource * (*io_create_watch)(QIOChannel *ioc,
+                                 GIOCondition condition);
+    int (*io_set_blocking)(QIOChannel *ioc,
+                           bool enabled,
+                           Error **errp);
+
+    /* Optional callbacks */
+    int (*io_shutdown)(QIOChannel *ioc,
+                       QIOChannelShutdown how,
+                       Error **errp);
+    void (*io_set_cork)(QIOChannel *ioc,
+                        bool enabled);
+    void (*io_set_delay)(QIOChannel *ioc,
+                         bool enabled);
+    off_t (*io_seek)(QIOChannel *ioc,
+                     off_t offset,
+                     int whence,
+                     Error **errp);
+};
+
+/* General I/O handling functions */
+
+/**
+ * qio_channel_has_feature:
+ * @ioc: the channel object
+ * @feature: the feature to check support of
+ *
+ * Determine whether the channel implementation supports
+ * the optional feature named in @feature.
+ *
+ * Returns: true if supported, false otherwise.
+ */
+bool qio_channel_has_feature(QIOChannel *ioc,
+                             QIOChannelFeature feature);
+
+/**
+ * qio_channel_readv_full:
+ * @ioc: the channel object
+ * @iov: the array of memory regions to read data into
+ * @niov: the length of the @iov array
+ * @fds: pointer to an array that will received file handles
+ * @nfds: pointer filled with number of elements in @fds on return
+ * @errp: pointer to an uninitialized error object
+ *
+ * Read data from the IO channel, storing it in the
+ * memory regions referenced by @iov. Each element
+ * in the @iov will be fully populated with data
+ * before the next one is used. The @niov parameter
+ * specifies the total number of elements in @iov.
+ *
+ * It is not required for all @iov to be filled with
+ * data. If the channel is in blocking mode, at least
+ * one byte of data will be read, but no more is
+ * guaranteed. If the channel is non-blocking and no
+ * data is available, it will return QIO_CHANNEL_ERR_BLOCK
+ *
+ * If the channel has passed any file descriptors,
+ * the @fds array pointer will be allocated and
+ * the elements filled with the received file
+ * descriptors. The @nfds pointer will be updated
+ * to indicate the size of the @fds array that
+ * was allocated. It is the callers responsibility
+ * to call close() on each file descriptor and to
+ * call g_free() on the array pointer in @fds.
+ *
+ * It is an error to pass a non-NULL @fds parameter
+ * unless qio_channel_has_feature() returns a true
+ * value for the QIO_CHANNEL_FEATURE_FD_PASS constant.
+ *
+ * Returns: the number of bytes read, or -1 on error,
+ * or QIO_CHANNEL_ERR_BLOCK if no data is available
+ * and the channel is non-blocking
+ */
+ssize_t qio_channel_readv_full(QIOChannel *ioc,
+                               const struct iovec *iov,
+                               size_t niov,
+                               int **fds,
+                               size_t *nfds,
+                               Error **errp);
+
+
+/**
+ * qio_channel_writev_full:
+ * @ioc: the channel object
+ * @iov: the array of memory regions to write data from
+ * @niov: the length of the @iov array
+ * @fds: an array of file handles to send
+ * @nfds: number of file handles in @fds
+ * @errp: pointer to an uninitialized error object
+ *
+ * Write data to the IO channel, reading it from the
+ * memory regions referenced by @iov. Each element
+ * in the @iov will be fully sent, before the next
+ * one is used. The @niov parameter specifies the
+ * total number of elements in @iov.
+ *
+ * It is not required for all @iov data to be fully
+ * sent. If the channel is in blocking mode, at least
+ * one byte of data will be sent, but no more is
+ * guaranteed. If the channel is non-blocking and no
+ * data can be sent, it will return QIO_CHANNEL_ERR_BLOCK
+ *
+ * If there are file descriptors to send, the @fds
+ * array should be non-NULL and provide the handles.
+ * All file descriptors will be sent if at least one
+ * byte of data was sent.
+ *
+ * It is an error to pass a non-NULL @fds parameter
+ * unless qio_channel_has_feature() returns a true
+ * value for the QIO_CHANNEL_FEATURE_FD_PASS constant.
+ *
+ * Returns: the number of bytes sent, or -1 on error,
+ * or QIO_CHANNEL_ERR_BLOCK if no data is can be sent
+ * and the channel is non-blocking
+ */
+ssize_t qio_channel_writev_full(QIOChannel *ioc,
+                                const struct iovec *iov,
+                                size_t niov,
+                                int *fds,
+                                size_t nfds,
+                                Error **errp);
+
+/**
+ * qio_channel_readv:
+ * @ioc: the channel object
+ * @iov: the array of memory regions to read data into
+ * @niov: the length of the @iov array
+ * @errp: pointer to an uninitialized error object
+ *
+ * Behaves as qio_channel_readv_full() but does not support
+ * receiving of file handles.
+ */
+ssize_t qio_channel_readv(QIOChannel *ioc,
+                          const struct iovec *iov,
+                          size_t niov,
+                          Error **errp);
+
+/**
+ * qio_channel_writev:
+ * @ioc: the channel object
+ * @iov: the array of memory regions to write data from
+ * @niov: the length of the @iov array
+ * @errp: pointer to an uninitialized error object
+ *
+ * Behaves as qio_channel_writev_full() but does not support
+ * sending of file handles.
+ */
+ssize_t qio_channel_writev(QIOChannel *ioc,
+                           const struct iovec *iov,
+                           size_t niov,
+                           Error **errp);
+
+/**
+ * qio_channel_readv:
+ * @ioc: the channel object
+ * @buf: the memory region to read data into
+ * @buflen: the length of @buf
+ * @errp: pointer to an uninitialized error object
+ *
+ * Behaves as qio_channel_readv_full() but does not support
+ * receiving of file handles, and only supports reading into
+ * a single memory region.
+ */
+ssize_t qio_channel_read(QIOChannel *ioc,
+                         char *buf,
+                         size_t buflen,
+                         Error **errp);
+
+/**
+ * qio_channel_writev:
+ * @ioc: the channel object
+ * @buf: the memory regions to send data from
+ * @buflen: the length of @buf
+ * @errp: pointer to an uninitialized error object
+ *
+ * Behaves as qio_channel_writev_full() but does not support
+ * sending of file handles, and only supports writing from a
+ * single memory region.
+ */
+ssize_t qio_channel_write(QIOChannel *ioc,
+                          const char *buf,
+                          size_t buflen,
+                          Error **errp);
+
+/**
+ * qio_channel_set_blocking:
+ * @ioc: the channel object
+ * @enabled: the blocking flag state
+ * @errp: pointer to an uninitialized error object
+ *
+ * If @enabled is true, then the channel is put into
+ * blocking mode, otherwise it will be non-blocking.
+ *
+ * In non-blocking mode, read/write operations may
+ * return QIO_CHANNEL_ERR_BLOCK if they would otherwise
+ * block on I/O
+ */
+int qio_channel_set_blocking(QIOChannel *ioc,
+                             bool enabled,
+                             Error **errp);
+
+/**
+ * qio_channel_close:
+ * @ioc: the channel object
+ * @errp: pointer to an uninitialized error object
+ *
+ * Close the channel, flushing any pending I/O
+ *
+ * Returns: 0 on success, -1 on error
+ */
+int qio_channel_close(QIOChannel *ioc,
+                      Error **errp);
+
+/**
+ * qio_channel_shutdown:
+ * @ioc: the channel object
+ * @how: the direction to shutdown
+ * @errp: pointer to an uninitialized error object
+ *
+ * Shutdowns transmission and/or receiving of data
+ * without closing the underlying transport.
+ *
+ * Not all implementations will support this facility,
+ * so may report an error. To avoid errors, the
+ * caller may check for the feature flag
+ * QIO_CHANNEL_FEATURE_SHUTDOWN prior to calling
+ * this method.
+ *
+ * Returns: 0 on success, -1 on error
+ */
+int qio_channel_shutdown(QIOChannel *ioc,
+                         QIOChannelShutdown how,
+                         Error **errp);
+
+/**
+ * qio_channel_set_delay:
+ * @ioc: the channel object
+ * @enabled: the new flag state
+ *
+ * Controls whether the underlying transport is
+ * permitted to delay writes in order to merge
+ * small packets. If @enabled is true, then the
+ * writes may be delayed in order to opportunistically
+ * merge small packets into larger ones. If @enabled
+ * is false, writes are dispatched immediately with
+ * no delay.
+ *
+ * When @enabled is false, applications may wish to
+ * use the qio_channel_set_cork() method to explicitly
+ * control write merging.
+ *
+ * On channels which are backed by a socket, this
+ * API corresponds to the inverse of TCP_NODELAY flag,
+ * controlling whether the Nagle algorithm is active.
+ *
+ * This setting is merely a hint, so implementations are
+ * free to ignore this without it being considered an
+ * error.
+ */
+void qio_channel_set_delay(QIOChannel *ioc,
+                           bool enabled);
+
+/**
+ * qio_channel_set_cork:
+ * @ioc: the channel object
+ * @enabled: the new flag state
+ *
+ * Controls whether the underlying transport is
+ * permitted to dispatch data that is written.
+ * If @enabled is true, then any data written will
+ * be queued in local buffers until @enabled is
+ * set to false once again.
+ *
+ * This feature is typically used when the automatic
+ * write coalescing facility is disabled via the
+ * qio_channel_set_delay() method.
+ *
+ * On channels which are backed by a socket, this
+ * API corresponds to the TCP_CORK flag.
+ *
+ * This setting is merely a hint, so implementations are
+ * free to ignore this without it being considered an
+ * error.
+ */
+void qio_channel_set_cork(QIOChannel *ioc,
+                          bool enabled);
+
+
+/**
+ * qio_channel_seek:
+ * @ioc: the channel object
+ * @offset: the position to seek to, relative to @whence
+ * @whence: one of the (POSIX) SEEK_* constants listed below
+ * @errp: pointer to an uninitialized error object
+ *
+ * Moves the current I/O position within the channel
+ * @ioc, to be @offset. The value of @offset is
+ * interpreted relative to @whence:
+ *
+ * SEEK_SET - the position is set to @offset bytes
+ * SEEK_CUR - the position is moved by @offset bytes
+ * SEEK_END - the position is set to end of the file plus @offset bytes
+ *
+ * Not all implementations will support this facility,
+ * so may report an error.
+ *
+ * Returns: the new position on success, (off_t)-1 on failure
+ */
+off_t qio_channel_io_seek(QIOChannel *ioc,
+                          off_t offset,
+                          int whence,
+                          Error **errp);
+
+
+/**
+ * qio_channel_create_watch:
+ * @ioc: the channel object
+ * @condition: the I/O condition to monitor
+ *
+ * Create a new main loop source that is used to watch
+ * for the I/O condition @condition. Typically the
+ * qio_channel_add_watch() method would be used instead
+ * of this, since it directly attaches a callback to
+ * the source
+ *
+ * Returns: the new main loop source.
+ */
+GSource *qio_channel_create_watch(QIOChannel *ioc,
+                                  GIOCondition condition);
+
+/**
+ * qio_channel_add_watch:
+ * @ioc: the channel object
+ * @condition: the I/O condition to monitor
+ * @func: callback to invoke when the source becomes ready
+ * @user_data: opaque data to pass to @func
+ * @notify: callback to free @user_data
+ *
+ * Create a new main loop source that is used to watch
+ * for the I/O condition @condition. The callback @func
+ * will be registered against the source, to be invoked
+ * when the source becomes ready. The optional @user_data
+ * will be passed to @func when it is invoked. The @notify
+ * callback will be used to free @user_data when the
+ * watch is deleted
+ *
+ * The returned source ID can be used with g_source_remove()
+ * to remove and free the source when no longer required.
+ * Alternatively the @func callback can return a FALSE
+ * value.
+ *
+ * Returns: the source ID
+ */
+guint qio_channel_add_watch(QIOChannel *ioc,
+                            GIOCondition condition,
+                            QIOChannelFunc func,
+                            gpointer user_data,
+                            GDestroyNotify notify);
+
+
+/**
+ * qio_channel_yield:
+ * @ioc: the channel object
+ * @condition: the I/O condition to wait for
+ *
+ * Yields execution from the current coroutine until
+ * the condition indicated by @condition becomes
+ * available.
+ *
+ * This must only be called from coroutine context
+ */
+void qio_channel_yield(QIOChannel *ioc,
+                       GIOCondition condition);
+
+/**
+ * qio_channel_wait:
+ * @ioc: the channel object
+ * @condition: the I/O condition to wait for
+ *
+ * Block execution from the current thread until
+ * the condition indicated by @condition becomes
+ * available.
+ *
+ * This will enter a nested event loop to perform
+ * the wait.
+ */
+void qio_channel_wait(QIOChannel *ioc,
+                      GIOCondition condition);
+
+#endif /* QIO_CHANNEL_H__ */

include/io/task.h

+/*
+ * QEMU I/O task
+ *
+ * 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_TASK_H__
+#define QIO_TASK_H__
+
+#include "qemu-common.h"
+#include "qapi/error.h"
+#include "qom/object.h"
+
+typedef struct QIOTask QIOTask;
+
+typedef void (*QIOTaskFunc)(Object *source,
+                            Error *err,
+                            gpointer opaque);
+
+typedef int (*QIOTaskWorker)(QIOTask *task,
+                             Error **errp,
+                             gpointer opaque);
+
+/**
+ * QIOTask:
+ *
+ * The QIOTask object provides a simple mechanism for reporting
+ * success / failure of long running background operations.
+ *
+ * A object on which the operation is to be performed could have
+ * a public API which accepts a task callback:
+ *
+ * <example>
+ *   <title>Task callback function signature</title>
+ *   <programlisting>
+ *  void myobject_operation(QMyObject *obj,
+ *                          QIOTaskFunc *func,
+ *                          gpointer opaque,
+ *                          GDestroyNotify *notify);
+ *   </programlisting>
+ * </example>
+ *
+ * The 'func' parameter is the callback to be invoked, and 'opaque'
+ * is data to pass to it. The optional 'notify' function is used
+ * to free 'opaque' when no longer needed.
+ *
+ * Now, lets say the implementation of this method wants to set
+ * a timer to run once a second checking for completion of some
+ * activity. It would do something like
+ *
+ * <example>
+ *   <title>Task callback function implementation</title>
+ *   <programlisting>
+ *    void myobject_operation(QMyObject *obj,
+ *                            QIOTaskFunc *func,
+ *                            gpointer opaque,
+ *                            GDestroyNotify *notify)
+ *    {
+ *      QIOTask *task;
+ *
+ *      task = qio_task_new(OBJECT(obj), func, opaque, notify);
+ *
+ *      g_timeout_add_full(G_PRIORITY_DEFAULT,
+ *                         1000,
+ *                         myobject_operation_timer,
+ *                         task,
+ *                         NULL);
+ *    }
+ *   </programlisting>
+ * </example>
+ *
+ * It could equally have setup a watch on a file descriptor or
+ * created a background thread, or something else entirely.
+ * Notice that the source object is passed to the task, and
+ * QIOTask will hold a reference on that. This ensure that
+ * the QMyObject instance cannot be garbage collected while
+ * the async task is still in progress.
+ *
+ * In this case, myobject_operation_timer will fire after
+ * 3 secs and do
+ *
+ * <example>
+ *   <title>Task timer function</title>
+ *   <programlisting>
+ *   gboolean myobject_operation_timer(gpointer opaque)
+ *   {
+ *      QIOTask *task = QIO_TASK(opaque);
+ *      Error *err;*
+ *
+ *      ...check something important...
+ *       if (err) {
+ *           qio_task_abort(task, err);
+ *           error_free(task);
+ *           return FALSE;
+ *       } else if (...work is completed ...) {
+ *           qio_task_complete(task);
+ *           return FALSE;
+ *       }
+ *       ...carry on polling ...
+ *       return TRUE;
+ *   }
+ *   </programlisting>
+ * </example>
+ *
+ * Once this function returns false, object_unref will be called
+ * automatically on the task causing it to be released and the
+ * ref on QMyObject dropped too.
+ *
+ * The QIOTask module can also be used to perform operations
+ * in a background thread context, while still reporting the
+ * results in the main event thread. This allows code which
+ * cannot easily be rewritten to be asychronous (such as DNS
+ * lookups) to be easily run non-blocking. Reporting the
+ * results in the main thread context means that the caller
+ * typically does not need to be concerned about thread
+ * safety wrt the QEMU global mutex.
+ *
+ * For example, the socket_listen() method will block the caller
+ * while DNS lookups take place if given a name, instead of IP
+ * address. The C library often do not provide a practical async
+ * DNS API, so the to get non-blocking DNS lookups in a portable
+ * manner requires use of a thread. So achieve a non-blocking
+ * socket listen using QIOTask would require:
+ *
+ * <example>
+ *    static int myobject_listen_worker(QIOTask *task,
+ *                                      Error **errp,
+ *                                      gpointer opaque)
+ *    {
+ *       QMyObject obj = QMY_OBJECT(qio_task_get_source(task));
+ *       SocketAddress *addr = opaque;
+ *
+ *       obj->fd = socket_listen(addr, errp);
+ *       if (obj->fd < 0) {
+ *          return -1;
+ *       }
+ *       return 0;
+ *    }
+ *
+ *    void myobject_listen_async(QMyObject *obj,
+ *                               SocketAddress *addr,
+ *                               QIOTaskFunc *func,
+ *                               gpointer opaque,
+ *                               GDestroyNotify *notify)
+ *    {
+ *      QIOTask *task;
+ *      SocketAddress *addrCopy;
+ *
+ *      qapi_copy_SocketAddress(&addrCopy, addr);
+ *      task = qio_task_new(OBJECT(obj), func, opaque, notify);
+ *
+ *      qio_task_run_in_thread(task, myobject_listen_worker,
+ *                             addrCopy,
+ *                             qapi_free_SocketAddress);
+ *    }
+ * </example>
+ *
+ * NB, The 'func' callback passed into myobject_listen_async
+ * will be invoked from the main event thread, despite the
+ * actual operation being performed in a different thread.
+ */
+
+/**
+ * qio_task_new:
+ * @source: the object on which the operation is invoked
+ * @func: the callback to invoke when the task completes
+ * @opaque: opaque data to pass to @func when invoked
+ * @destroy: optional callback to free @opaque
+ *
+ * Creates a new task struct to track completion of a
+ * background operation running on the object @source.
+ * When the operation completes or fails, the callback
+ * @func will be invoked. The callback can access the
+ * 'err' attribute in the task object to determine if
+ * the operation was successful or not.
+ *
+ * The returned task will be released when one of
+ * qio_task_abort() or qio_task_complete() are invoked.
+ *
+ * Returns: the task struct
+ */
+QIOTask *qio_task_new(Object *source,
+                      QIOTaskFunc func,
+                      gpointer opaque,
+                      GDestroyNotify destroy);
+
+/**
+ * qio_task_run_in_thread:
+ * @task: the task struct
+ * @worker: the function to invoke in a thread
+ * @opaque: opaque data to pass to @worker
+ * @destroy: function to free @opaque
+ *
+ * Run a task in a background thread. If @worker
+ * returns 0 it will call qio_task_complete() in
+ * the main event thread context. If @worker
+ * returns -1 it will call qio_task_abort() in
+ * the main event thread context.
+ */
+void qio_task_run_in_thread(QIOTask *task,
+                            QIOTaskWorker worker,
+                            gpointer opaque,
+                            GDestroyNotify destroy);
+
+/**
+ * qio_task_complete:
+ * @task: the task struct
+ *
+ * Mark the operation as succesfully completed
+ * and free the memory for @task.
+ */
+void qio_task_complete(QIOTask *task);
+
+/**
+ * qio_task_abort:
+ * @task: the task struct
+ * @err: the error to record for the operation
+ *
+ * Mark the operation as failed, with @err providing
+ * details about the failure. The @err may be freed
+ * afer the function returns, as the notification
+ * callback is invoked synchronously. The @task will
+ * be freed when this call completes.
+ */
+void qio_task_abort(QIOTask *task,
+                    Error *err);
+
+
+/**
+ * qio_task_get_source:
+ * @task: the task struct
+ *
+ * Get the source object associated with the background
+ * task. This returns a new reference to the object,
+ * which the caller must released with object_unref()
+ * when no longer required.
+ *
+ * Returns: the source object
+ */
+Object *qio_task_get_source(QIOTask *task);
+
+#endif /* QIO_TASK_H__ */

include/qemu/sockets.h

@@ -88,6 +88,25 @@ int socket_dgram(SocketAddress *remote, SocketAddress *local, Error **errp);
 int parse_host_port(struct sockaddr_in *saddr, const char *str);
 int socket_init(void);
 
+/**
+ * socket_sockaddr_to_address:
+ * @sa: socket address struct
+ * @salen: size of @sa struct
+ * @errp: pointer to uninitialized error object
+ *
+ * Get the string representation of the 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 *
+socket_sockaddr_to_address(struct sockaddr_storage *sa,
+                           socklen_t salen,
+                           Error **errp);
+
 /**
  * socket_local_address:
  * @fd: the socket file handle

io/Makefile.objs

+io-obj-y = channel.o
+io-obj-y += channel-buffer.o
+io-obj-y += channel-command.o
+io-obj-y += channel-file.o
+io-obj-y += channel-socket.o
+io-obj-y += channel-tls.o
+io-obj-y += channel-watch.o
+io-obj-y += channel-websock.o
+io-obj-y += task.o

io/channel-buffer.c

+/*
+ * QEMU I/O channels memory buffer 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/>.
+ *
+ */
+
+#include "io/channel-buffer.h"
+#include "io/channel-watch.h"
+#include "qemu/sockets.h"
+#include "trace.h"
+
+QIOChannelBuffer *
+qio_channel_buffer_new(size_t capacity)
+{
+    QIOChannelBuffer *ioc;
+
+    ioc = QIO_CHANNEL_BUFFER(object_new(TYPE_QIO_CHANNEL_BUFFER));
+
+    if (capacity) {
+        ioc->data = g_new0(char, capacity);
+        ioc->capacity = capacity;
+    }
+
+    return ioc;
+}
+
+
+static void qio_channel_buffer_finalize(Object *obj)
+{
+    QIOChannelBuffer *ioc = QIO_CHANNEL_BUFFER(obj);
+    g_free(ioc->data);
+    ioc->capacity = ioc->usage = ioc->offset = 0;
+}
+
+
+static ssize_t qio_channel_buffer_readv(QIOChannel *ioc,
+                                        const struct iovec *iov,
+                                        size_t niov,
+                                        int **fds,
+                                        size_t *nfds,
+                                        Error **errp)
+{
+    QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
+    ssize_t ret = 0;
+    size_t i;
+
+    for (i = 0; i < niov; i++) {
+        size_t want = iov[i].iov_len;
+        if (bioc->offset >= bioc->usage) {
+            break;
+        }
+        if ((bioc->offset + want) > bioc->usage)  {
+            want = bioc->usage - bioc->offset;
+        }
+        memcpy(iov[i].iov_base, bioc->data + bioc->offset, want);
+        ret += want;
+        bioc->offset += want;
+    }
+
+    return ret;
+}
+
+static ssize_t qio_channel_buffer_writev(QIOChannel *ioc,
+                                         const struct iovec *iov,
+                                         size_t niov,
+                                         int *fds,
+                                         size_t nfds,
+                                         Error **errp)
+{
+    QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
+    ssize_t ret = 0;
+    size_t i;
+    size_t towrite = 0;
+
+    for (i = 0; i < niov; i++) {
+        towrite += iov[i].iov_len;
+    }
+
+    if ((bioc->offset + towrite) > bioc->capacity) {
+        bioc->capacity = bioc->offset + towrite;
+        bioc->data = g_realloc(bioc->data, bioc->capacity);
+    }
+
+    if (bioc->offset > bioc->usage) {
+        memset(bioc->data, 0, bioc->offset - bioc->usage);
+        bioc->usage = bioc->offset;
+    }
+
+    for (i = 0; i < niov; i++) {
+        memcpy(bioc->data + bioc->usage,
+               iov[i].iov_base,
+               iov[i].iov_len);
+        bioc->usage += iov[i].iov_len;
+        bioc->offset += iov[i].iov_len;
+        ret += iov[i].iov_len;
+    }
+
+    return ret;
+}
+
+static int qio_channel_buffer_set_blocking(QIOChannel *ioc G_GNUC_UNUSED,
+                                           bool enabled G_GNUC_UNUSED,
+                                           Error **errp G_GNUC_UNUSED)
+{
+    return 0;
+}
+
+
+static off_t qio_channel_buffer_seek(QIOChannel *ioc,
+                                     off_t offset,
+                                     int whence,
+                                     Error **errp)
+{
+    QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
+
+    bioc->offset = offset;
+
+    return offset;
+}
+
+
+static int qio_channel_buffer_close(QIOChannel *ioc,
+                                    Error **errp)
+{
+    QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
+
+    g_free(bioc->data);
+    bioc->capacity = bioc->usage = bioc->offset = 0;
+
+    return 0;
+}
+
+
+typedef struct QIOChannelBufferSource QIOChannelBufferSource;
+struct QIOChannelBufferSource {
+    GSource parent;
+    QIOChannelBuffer *bioc;
+    GIOCondition condition;
+};
+
+static gboolean
+qio_channel_buffer_source_prepare(GSource *source,
+                                  gint *timeout)
+{
+    QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source;
+
+    *timeout = -1;
+
+    return (G_IO_IN | G_IO_OUT) & bsource->condition;
+}
+
+static gboolean
+qio_channel_buffer_source_check(GSource *source)
+{
+    QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source;
+
+    return (G_IO_IN | G_IO_OUT) & bsource->condition;
+}
+
+static gboolean
+qio_channel_buffer_source_dispatch(GSource *source,
+                                   GSourceFunc callback,
+                                   gpointer user_data)
+{
+    QIOChannelFunc func = (QIOChannelFunc)callback;
+    QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source;
+
+    return (*func)(QIO_CHANNEL(bsource->bioc),
+                   ((G_IO_IN | G_IO_OUT) & bsource->condition),
+                   user_data);
+}
+
+static void
+qio_channel_buffer_source_finalize(GSource *source)
+{
+    QIOChannelBufferSource *ssource = (QIOChannelBufferSource *)source;
+
+    object_unref(OBJECT(ssource->bioc));
+}
+
+GSourceFuncs qio_channel_buffer_source_funcs = {
+    qio_channel_buffer_source_prepare,
+    qio_channel_buffer_source_check,
+    qio_channel_buffer_source_dispatch,
+    qio_channel_buffer_source_finalize
+};
+
+static GSource *qio_channel_buffer_create_watch(QIOChannel *ioc,
+                                                GIOCondition condition)
+{
+    QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
+    QIOChannelBufferSource *ssource;
+    GSource *source;
+
+    source = g_source_new(&qio_channel_buffer_source_funcs,
+                          sizeof(QIOChannelBufferSource));
+    ssource = (QIOChannelBufferSource *)source;
+
+    ssource->bioc = bioc;
+    object_ref(OBJECT(bioc));
+
+    ssource->condition = condition;
+
+    return source;
+}
+
+
+static void qio_channel_buffer_class_init(ObjectClass *klass,
+                                          void *class_data G_GNUC_UNUSED)
+{
+    QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
+
+    ioc_klass->io_writev = qio_channel_buffer_writev;
+    ioc_klass->io_readv = qio_channel_buffer_readv;
+    ioc_klass->io_set_blocking = qio_channel_buffer_set_blocking;
+    ioc_klass->io_seek = qio_channel_buffer_seek;
+    ioc_klass->io_close = qio_channel_buffer_close;
+    ioc_klass->io_create_watch = qio_channel_buffer_create_watch;
+}
+
+static const TypeInfo qio_channel_buffer_info = {
+    .parent = TYPE_QIO_CHANNEL,
+    .name = TYPE_QIO_CHANNEL_BUFFER,
+    .instance_size = sizeof(QIOChannelBuffer),
+    .instance_finalize = qio_channel_buffer_finalize,
+    .class_init = qio_channel_buffer_class_init,
+};
+
+static void qio_channel_buffer_register_types(void)
+{
+    type_register_static(&qio_channel_buffer_info);
+}
+
+type_init(qio_channel_buffer_register_types);

io/channel-command.c

+/*
+ * QEMU I/O channels external command 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/>.
+ *
+ */
+
+#include "io/channel-command.h"
+#include "io/channel-watch.h"
+#include "qemu/sockets.h"
+#include "trace.h"
+
+
+QIOChannelCommand *
+qio_channel_command_new_pid(int writefd,
+                            int readfd,
+                            pid_t pid)
+{
+    QIOChannelCommand *ioc;
+
+    ioc = QIO_CHANNEL_COMMAND(object_new(TYPE_QIO_CHANNEL_COMMAND));
+
+    ioc->readfd = readfd;
+    ioc->writefd = writefd;
+    ioc->pid = pid;
+
+    trace_qio_channel_command_new_pid(ioc, writefd, readfd, pid);
+    return ioc;
+}
+
+
+#ifndef WIN32
+QIOChannelCommand *
+qio_channel_command_new_spawn(const char *const argv[],
+                              int flags,
+                              Error **errp)
+{
+    pid_t pid = -1;
+    int stdinfd[2] = { -1, -1 };
+    int stdoutfd[2] = { -1, -1 };
+    int devnull = -1;
+    bool stdinnull = false, stdoutnull = false;
+    QIOChannelCommand *ioc;
+
+    flags = flags & O_ACCMODE;
+
+    if (flags == O_RDONLY) {
+        stdinnull = true;
+    }
+    if (flags == O_WRONLY) {
+        stdoutnull = true;
+    }
+
+    if (stdinnull || stdoutnull) {
+        devnull = open("/dev/null", O_RDWR);
+        if (!devnull) {
+            error_setg_errno(errp, errno,
+                             "Unable to open /dev/null");
+            goto error;
+        }
+    }
+
+    if ((!stdinnull && pipe(stdinfd) < 0) ||
+        (!stdoutnull && pipe(stdoutfd) < 0)) {
+        error_setg_errno(errp, errno,
+                         "Unable to open pipe");
+        goto error;
+    }
+
+    pid = qemu_fork(errp);
+    if (pid < 0) {
+        goto error;
+    }
+
+    if (pid == 0) { /* child */
+        dup2(stdinnull ? devnull : stdinfd[0], STDIN_FILENO);
+        dup2(stdoutnull ? devnull : stdoutfd[1], STDOUT_FILENO);
+        /* Leave stderr connected to qemu's stderr */
+
+        if (!stdinnull) {
+            close(stdinfd[0]);
+            close(stdinfd[1]);
+        }
+        if (!stdoutnull) {
+            close(stdoutfd[0]);
+            close(stdoutfd[1]);
+        }
+
+        execv(argv[0], (char * const *)argv);
+        _exit(1);
+    }
+
+    if (!stdinnull) {
+        close(stdinfd[0]);
+    }
+    if (!stdoutnull) {
+        close(stdoutfd[1]);
+    }
+
+    ioc = qio_channel_command_new_pid(stdinnull ? devnull : stdinfd[1],
+                                      stdoutnull ? devnull : stdoutfd[0],
+                                      pid);
+    trace_qio_channel_command_new_spawn(ioc, argv[0], flags);
+    return ioc;
+
+ error:
+    if (stdinfd[0] != -1) {
+        close(stdinfd[0]);
+    }
+    if (stdinfd[1] != -1) {
+        close(stdinfd[1]);
+    }
+    if (stdoutfd[0] != -1) {
+        close(stdoutfd[0]);
+    }
+    if (stdoutfd[1] != -1) {
+        close(stdoutfd[1]);
+    }
+    return NULL;
+}
+
+#else /* WIN32 */
+QIOChannelCommand *
+qio_channel_command_new_spawn(const char *const argv[],
+                              int flags,
+                              Error **errp)
+{
+    error_setg_errno(errp, ENOSYS,
+                     "Command spawn not supported on this platform");
+    return NULL;
+}
+#endif /* WIN32 */
+
+#ifndef WIN32
+static int qio_channel_command_abort(QIOChannelCommand *ioc,
+                                     Error **errp)
+{
+    pid_t ret;
+    int status;
+    int step = 0;
+
+    /* See if intermediate process has exited; if not, try a nice
+     * SIGTERM followed by a more severe SIGKILL.
+     */
+ rewait:
+    trace_qio_channel_command_abort(ioc, ioc->pid);
+    ret = waitpid(ioc->pid, &status, WNOHANG);
+    trace_qio_channel_command_wait(ioc, ioc->pid, ret, status);
+    if (ret == (pid_t)-1) {
+        if (errno == EINTR) {
+            goto rewait;
+        } else {
+            error_setg_errno(errp, errno,
+                             "Cannot wait on pid %llu",
+                             (unsigned long long)ioc->pid);
+            return -1;
+        }
+    } else if (ret == 0) {
+        if (step == 0) {
+            kill(ioc->pid, SIGTERM);
+        } else if (step == 1) {
+            kill(ioc->pid, SIGKILL);
+        } else {
+            error_setg(errp,
+                       "Process %llu refused to die",
+                       (unsigned long long)ioc->pid);
+            return -1;
+        }
+        usleep(10 * 1000);
+        goto rewait;
+    }
+
+    return 0;
+}
+#endif /* ! WIN32 */
+
+
+static void qio_channel_command_init(Object *obj)
+{
+    QIOChannelCommand *ioc = QIO_CHANNEL_COMMAND(obj);
+    ioc->readfd = -1;
+    ioc->writefd = -1;
+    ioc->pid = -1;
+}
+
+static void qio_channel_command_finalize(Object *obj)
+{
+    QIOChannelCommand *ioc = QIO_CHANNEL_COMMAND(obj);
+    if (ioc->readfd != -1) {
+        close(ioc->readfd);
+        ioc->readfd = -1;
+    }
+    if (ioc->writefd != -1) {
+        close(ioc->writefd);
+        ioc->writefd = -1;
+    }
+    if (ioc->pid > 0) {
+#ifndef WIN32
+        qio_channel_command_abort(ioc, NULL);
+#endif
+    }
+}
+
+
+static ssize_t qio_channel_command_readv(QIOChannel *ioc,
+                                         const struct iovec *iov,
+                                         size_t niov,
+                                         int **fds,
+                                         size_t *nfds,
+                                         Error **errp)
+{
+    QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+    ssize_t ret;
+
+ retry:
+    ret = readv(cioc->readfd, iov, niov);
+    if (ret < 0) {
+        if (errno == EAGAIN ||
+            errno == EWOULDBLOCK) {
+            return QIO_CHANNEL_ERR_BLOCK;
+        }
+        if (errno == EINTR) {
+            goto retry;
+        }
+
+        error_setg_errno(errp, errno,
+                         "Unable to read from command");
+        return -1;
+    }
+
+    return ret;
+}
+
+static ssize_t qio_channel_command_writev(QIOChannel *ioc,
+                                          const struct iovec *iov,
+                                          size_t niov,
+                                          int *fds,
+                                          size_t nfds,
+                                          Error **errp)
+{
+    QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+    ssize_t ret;
+
+ retry:
+    ret = writev(cioc->writefd, iov, niov);
+    if (ret <= 0) {
+        if (errno == EAGAIN ||
+            errno == EWOULDBLOCK) {
+            return QIO_CHANNEL_ERR_BLOCK;
+        }
+        if (errno == EINTR) {
+            goto retry;
+        }
+        error_setg_errno(errp, errno, "%s",
+                         "Unable to write to command");
+        return -1;
+    }
+    return ret;
+}
+
+static int qio_channel_command_set_blocking(QIOChannel *ioc,
+                                            bool enabled,
+                                            Error **errp)
+{
+    QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+
+    if (enabled) {
+        qemu_set_block(cioc->writefd);
+        qemu_set_block(cioc->readfd);
+    } else {
+        qemu_set_nonblock(cioc->writefd);
+        qemu_set_nonblock(cioc->readfd);
+    }
+
+    return 0;
+}
+
+
+static int qio_channel_command_close(QIOChannel *ioc,
+                                     Error **errp)
+{
+    QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+    int rv = 0;
+
+    /* We close FDs before killing, because that
+     * gives a better chance of clean shutdown
+     */
+    if (close(cioc->writefd) < 0) {
+        rv = -1;
+    }
+    if (close(cioc->readfd) < 0) {
+        rv = -1;
+    }
+#ifndef WIN32
+    if (qio_channel_command_abort(cioc, errp) < 0) {
+        return -1;
+    }
+#endif
+    if (rv < 0) {
+        error_setg_errno(errp, errno, "%s",
+                         "Unable to close command");
+    }
+    return rv;
+}
+
+
+static GSource *qio_channel_command_create_watch(QIOChannel *ioc,
+                                                 GIOCondition condition)
+{
+    QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+    return qio_channel_create_fd_pair_watch(ioc,
+                                            cioc->readfd,
+                                            cioc->writefd,
+                                            condition);
+}
+
+
+static void qio_channel_command_class_init(ObjectClass *klass,
+                                           void *class_data G_GNUC_UNUSED)
+{
+    QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
+
+    ioc_klass->io_writev = qio_channel_command_writev;
+    ioc_klass->io_readv = qio_channel_command_readv;
+    ioc_klass->io_set_blocking = qio_channel_command_set_blocking;
+    ioc_klass->io_close = qio_channel_command_close;
+    ioc_klass->io_create_watch = qio_channel_command_create_watch;
+}
+
+static const TypeInfo qio_channel_command_info = {
+    .parent = TYPE_QIO_CHANNEL,
+    .name = TYPE_QIO_CHANNEL_COMMAND,
+    .instance_size = sizeof(QIOChannelCommand),
+    .instance_init = qio_channel_command_init,
+    .instance_finalize = qio_channel_command_finalize,
+    .class_init = qio_channel_command_class_init,
+};
+
+static void qio_channel_command_register_types(void)
+{
+    type_register_static(&qio_channel_command_info);
+}
+
+type_init(qio_channel_command_register_types);

io/channel-file.c

+/*
+ * QEMU I/O channels files 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/>.
+ *
+ */
+
+#include "io/channel-file.h"
+#include "io/channel-watch.h"
+#include "qemu/sockets.h"
+#include "trace.h"
+
+QIOChannelFile *
+qio_channel_file_new_fd(int fd)
+{
+    QIOChannelFile *ioc;
+
+    ioc = QIO_CHANNEL_FILE(object_new(TYPE_QIO_CHANNEL_FILE));
+
+    ioc->fd = fd;
+
+    trace_qio_channel_file_new_fd(ioc, fd);
+
+    return ioc;
+}
+
+
+QIOChannelFile *
+qio_channel_file_new_path(const char *path,
+                          int flags,
+                          mode_t mode,
+                          Error **errp)
+{
+    QIOChannelFile *ioc;
+
+    ioc = QIO_CHANNEL_FILE(object_new(TYPE_QIO_CHANNEL_FILE));
+
+    if (flags & O_WRONLY) {
+        ioc->fd = open(path, flags, mode);
+    } else {
+        ioc->fd = open(path, flags);
+    }
+    if (ioc->fd < 0) {
+        object_unref(OBJECT(ioc));
+        error_setg_errno(errp, errno,
+                         "Unable to open %s", path);
+        return NULL;
+    }
+
+    trace_qio_channel_file_new_path(ioc, path, flags, mode, ioc->fd);
+
+    return ioc;
+}
+
+
+static void qio_channel_file_init(Object *obj)
+{
+    QIOChannelFile *ioc = QIO_CHANNEL_FILE(obj);
+    ioc->fd = -1;
+}
+
+static void qio_channel_file_finalize(Object *obj)
+{
+    QIOChannelFile *ioc = QIO_CHANNEL_FILE(obj);
+    if (ioc->fd != -1) {
+        close(ioc->fd);
+        ioc->fd = -1;
+    }
+}
+
+
+static ssize_t qio_channel_file_readv(QIOChannel *ioc,
+                                      const struct iovec *iov,
+                                      size_t niov,
+                                      int **fds,
+                                      size_t *nfds,
+                                      Error **errp)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+    ssize_t ret;
+
+ retry:
+    ret = readv(fioc->fd, iov, niov);
+    if (ret < 0) {
+        if (errno == EAGAIN ||
+            errno == EWOULDBLOCK) {
+            return QIO_CHANNEL_ERR_BLOCK;
+        }
+        if (errno == EINTR) {
+            goto retry;
+        }
+
+        error_setg_errno(errp, errno,
+                         "Unable to read from file");
+        return -1;
+    }
+
+    return ret;
+}
+
+static ssize_t qio_channel_file_writev(QIOChannel *ioc,
+                                       const struct iovec *iov,
+                                       size_t niov,
+                                       int *fds,
+                                       size_t nfds,
+                                       Error **errp)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+    ssize_t ret;
+
+ retry:
+    ret = writev(fioc->fd, iov, niov);
+    if (ret <= 0) {
+        if (errno == EAGAIN ||
+            errno == EWOULDBLOCK) {
+            return QIO_CHANNEL_ERR_BLOCK;
+        }
+        if (errno == EINTR) {
+            goto retry;
+        }
+        error_setg_errno(errp, errno,
+                         "Unable to write to file");
+        return -1;
+    }
+    return ret;
+}
+
+static int qio_channel_file_set_blocking(QIOChannel *ioc,
+                                         bool enabled,
+                                         Error **errp)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+
+    if (enabled) {
+        qemu_set_block(fioc->fd);
+    } else {
+        qemu_set_nonblock(fioc->fd);
+    }
+    return 0;
+}
+
+
+static off_t qio_channel_file_seek(QIOChannel *ioc,
+                                   off_t offset,
+                                   int whence,
+                                   Error **errp)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+    off_t ret;
+
+    ret = lseek(fioc->fd, offset, whence);
+    if (ret == (off_t)-1) {
+        error_setg_errno(errp, errno,
+                         "Unable to seek to offset %lld whence %d in file",
+                         (long long int)offset, whence);
+        return -1;
+    }
+    return ret;
+}
+
+
+static int qio_channel_file_close(QIOChannel *ioc,
+                                  Error **errp)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+
+    if (close(fioc->fd) < 0) {
+        error_setg_errno(errp, errno,
+                         "Unable to close file");
+        return -1;
+    }
+    return 0;
+}
+
+
+static GSource *qio_channel_file_create_watch(QIOChannel *ioc,
+                                              GIOCondition condition)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+    return qio_channel_create_fd_watch(ioc,
+                                       fioc->fd,
+                                       condition);
+}
+
+static void qio_channel_file_class_init(ObjectClass *klass,
+                                        void *class_data G_GNUC_UNUSED)
+{
+    QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
+
+    ioc_klass->io_writev = qio_channel_file_writev;
+    ioc_klass->io_readv = qio_channel_file_readv;
+    ioc_klass->io_set_blocking = qio_channel_file_set_blocking;
+    ioc_klass->io_seek = qio_channel_file_seek;
+    ioc_klass->io_close = qio_channel_file_close;
+    ioc_klass->io_create_watch = qio_channel_file_create_watch;
+}
+
+static const TypeInfo qio_channel_file_info = {
+    .parent = TYPE_QIO_CHANNEL,
+    .name = TYPE_QIO_CHANNEL_FILE,
+    .instance_size = sizeof(QIOChannelFile),
+    .instance_init = qio_channel_file_init,
+    .instance_finalize = qio_channel_file_finalize,
+    .class_init = qio_channel_file_class_init,
+};
+
+static void qio_channel_file_register_types(void)
+{
+    type_register_static(&qio_channel_file_info);
+}
+
+type_init(qio_channel_file_register_types);

io/channel-tls.c

+/*
+ * QEMU I/O channels TLS 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/>.
+ *
+ */
+
+#include "io/channel-tls.h"
+#include "trace.h"
+
+
+static ssize_t qio_channel_tls_write_handler(const char *buf,
+                                             size_t len,
+                                             void *opaque)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(opaque);
+    ssize_t ret;
+
+    ret = qio_channel_write(tioc->master, buf, len, NULL);
+    if (ret == QIO_CHANNEL_ERR_BLOCK) {
+        errno = EAGAIN;
+        return -1;
+    } else if (ret < 0) {
+        errno = EIO;
+        return -1;
+    }
+    return ret;
+}
+
+static ssize_t qio_channel_tls_read_handler(char *buf,
+                                            size_t len,
+                                            void *opaque)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(opaque);
+    ssize_t ret;
+
+    ret = qio_channel_read(tioc->master, buf, len, NULL);
+    if (ret == QIO_CHANNEL_ERR_BLOCK) {
+        errno = EAGAIN;
+        return -1;
+    } else if (ret < 0) {
+        errno = EIO;
+        return -1;
+    }
+    return ret;
+}
+
+
+QIOChannelTLS *
+qio_channel_tls_new_server(QIOChannel *master,
+                           QCryptoTLSCreds *creds,
+                           const char *aclname,
+                           Error **errp)
+{
+    QIOChannelTLS *ioc;
+
+    ioc = QIO_CHANNEL_TLS(object_new(TYPE_QIO_CHANNEL_TLS));
+
+    ioc->master = master;
+    object_ref(OBJECT(master));
+
+    ioc->session = qcrypto_tls_session_new(
+        creds,
+        NULL,
+        aclname,
+        QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
+        errp);
+    if (!ioc->session) {
+        goto error;
+    }
+
+    qcrypto_tls_session_set_callbacks(
+        ioc->session,
+        qio_channel_tls_write_handler,
+        qio_channel_tls_read_handler,
+        ioc);
+
+    trace_qio_channel_tls_new_server(ioc, master, creds, aclname);
+    return ioc;
+
+ error:
+    object_unref(OBJECT(ioc));
+    return NULL;
+}
+
+QIOChannelTLS *
+qio_channel_tls_new_client(QIOChannel *master,
+                           QCryptoTLSCreds *creds,
+                           const char *hostname,
+                           Error **errp)
+{
+    QIOChannelTLS *tioc;
+    QIOChannel *ioc;
+
+    tioc = QIO_CHANNEL_TLS(object_new(TYPE_QIO_CHANNEL_TLS));
+    ioc = QIO_CHANNEL(tioc);
+
+    tioc->master = master;
+    if (master->features & (1 << QIO_CHANNEL_FEATURE_SHUTDOWN)) {
+        ioc->features |= (1 << QIO_CHANNEL_FEATURE_SHUTDOWN);
+    }
+    object_ref(OBJECT(master));
+
+    tioc->session = qcrypto_tls_session_new(
+        creds,
+        hostname,
+        NULL,
+        QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT,
+        errp);
+    if (!tioc->session) {
+        goto error;
+    }
+
+    qcrypto_tls_session_set_callbacks(
+        tioc->session,
+        qio_channel_tls_write_handler,
+        qio_channel_tls_read_handler,
+        tioc);
+
+    trace_qio_channel_tls_new_client(tioc, master, creds, hostname);
+    return tioc;
+
+ error:
+    object_unref(OBJECT(tioc));
+    return NULL;
+}
+
+
+static gboolean qio_channel_tls_handshake_io(QIOChannel *ioc,
+                                             GIOCondition condition,
+                                             gpointer user_data);
+
+static void qio_channel_tls_handshake_task(QIOChannelTLS *ioc,
+                                           QIOTask *task)
+{
+    Error *err = NULL;
+    QCryptoTLSSessionHandshakeStatus status;
+
+    if (qcrypto_tls_session_handshake(ioc->session, &err) < 0) {
+        trace_qio_channel_tls_handshake_fail(ioc);
+        qio_task_abort(task, err);
+        goto cleanup;
+    }
+
+    status = qcrypto_tls_session_get_handshake_status(ioc->session);
+    if (status == QCRYPTO_TLS_HANDSHAKE_COMPLETE) {
+        trace_qio_channel_tls_handshake_complete(ioc);
+        if (qcrypto_tls_session_check_credentials(ioc->session,
+                                                  &err) < 0) {
+            trace_qio_channel_tls_credentials_deny(ioc);
+            qio_task_abort(task, err);
+            goto cleanup;
+        }
+        trace_qio_channel_tls_credentials_allow(ioc);
+        qio_task_complete(task);
+    } else {
+        GIOCondition condition;
+        if (status == QCRYPTO_TLS_HANDSHAKE_SENDING) {
+            condition = G_IO_OUT;
+        } else {
+            condition = G_IO_IN;
+        }
+
+        trace_qio_channel_tls_handshake_pending(ioc, status);
+        qio_channel_add_watch(ioc->master,
+                              condition,
+                              qio_channel_tls_handshake_io,
+                              task,
+                              NULL);
+    }
+
+ cleanup:
+    error_free(err);
+}
+
+
+static gboolean qio_channel_tls_handshake_io(QIOChannel *ioc,
+                                             GIOCondition condition,
+                                             gpointer user_data)
+{
+    QIOTask *task = user_data;
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(
+        qio_task_get_source(task));
+
+    qio_channel_tls_handshake_task(
+       tioc, task);
+
+    object_unref(OBJECT(tioc));
+
+    return FALSE;
+}
+
+void qio_channel_tls_handshake(QIOChannelTLS *ioc,
+                               QIOTaskFunc func,
+                               gpointer opaque,
+                               GDestroyNotify destroy)
+{
+    QIOTask *task;
+
+    task = qio_task_new(OBJECT(ioc),
+                        func, opaque, destroy);
+
+    trace_qio_channel_tls_handshake_start(ioc);
+    qio_channel_tls_handshake_task(ioc, task);
+}
+
+
+static void qio_channel_tls_init(Object *obj G_GNUC_UNUSED)
+{
+}
+
+
+static void qio_channel_tls_finalize(Object *obj)
+{
+    QIOChannelTLS *ioc = QIO_CHANNEL_TLS(obj);
+
+    object_unref(OBJECT(ioc->master));
+    qcrypto_tls_session_free(ioc->session);
+}
+
+
+static ssize_t qio_channel_tls_readv(QIOChannel *ioc,
+                                     const struct iovec *iov,
+                                     size_t niov,
+                                     int **fds,
+                                     size_t *nfds,
+                                     Error **errp)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+    size_t i;
+    ssize_t got = 0;
+
+    for (i = 0 ; i < niov ; i++) {
+        ssize_t ret = qcrypto_tls_session_read(tioc->session,
+                                               iov[i].iov_base,
+                                               iov[i].iov_len);
+        if (ret < 0) {
+            if (errno == EAGAIN) {
+                if (got) {
+                    return got;
+                } else {
+                    return QIO_CHANNEL_ERR_BLOCK;
+                }
+            }
+
+            error_setg_errno(errp, errno,
+                             "Cannot read from TLS channel");
+            return -1;
+        }
+        got += ret;
+        if (ret < iov[i].iov_len) {
+            break;
+        }
+    }
+    return got;
+}
+
+
+static ssize_t qio_channel_tls_writev(QIOChannel *ioc,
+                                      const struct iovec *iov,
+                                      size_t niov,
+                                      int *fds,
+                                      size_t nfds,
+                                      Error **errp)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+    size_t i;
+    ssize_t done = 0;
+
+    for (i = 0 ; i < niov ; i++) {
+        ssize_t ret = qcrypto_tls_session_write(tioc->session,
+                                                iov[i].iov_base,
+                                                iov[i].iov_len);
+        if (ret <= 0) {
+            if (errno == EAGAIN) {
+                if (done) {
+                    return done;
+                } else {
+                    return QIO_CHANNEL_ERR_BLOCK;
+                }
+            }
+
+            error_setg_errno(errp, errno,
+                             "Cannot write to TLS channel");
+            return -1;
+        }
+        done += ret;
+        if (ret < iov[i].iov_len) {
+            break;
+        }
+    }
+    return done;
+}
+
+static int qio_channel_tls_set_blocking(QIOChannel *ioc,
+                                        bool enabled,
+                                        Error **errp)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+
+    return qio_channel_set_blocking(tioc->master, enabled, errp);
+}
+
+static void qio_channel_tls_set_delay(QIOChannel *ioc,
+                                      bool enabled)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+
+    qio_channel_set_delay(tioc->master, enabled);
+}
+
+static void qio_channel_tls_set_cork(QIOChannel *ioc,
+                                     bool enabled)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+
+    qio_channel_set_cork(tioc->master, enabled);
+}
+
+static int qio_channel_tls_shutdown(QIOChannel *ioc,
+                                    QIOChannelShutdown how,
+                                    Error **errp)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+
+    return qio_channel_shutdown(tioc->master, how, errp);
+}
+
+static int qio_channel_tls_close(QIOChannel *ioc,
+                                 Error **errp)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+
+    return qio_channel_close(tioc->master, errp);
+}
+
+static GSource *qio_channel_tls_create_watch(QIOChannel *ioc,
+                                             GIOCondition condition)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+
+    return qio_channel_create_watch(tioc->master, condition);
+}
+
+QCryptoTLSSession *
+qio_channel_tls_get_session(QIOChannelTLS *ioc)
+{
+    return ioc->session;
+}
+
+static void qio_channel_tls_class_init(ObjectClass *klass,
+                                       void *class_data G_GNUC_UNUSED)
+{
+    QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
+
+    ioc_klass->io_writev = qio_channel_tls_writev;
+    ioc_klass->io_readv = qio_channel_tls_readv;
+    ioc_klass->io_set_blocking = qio_channel_tls_set_blocking;
+    ioc_klass->io_set_delay = qio_channel_tls_set_delay;
+    ioc_klass->io_set_cork = qio_channel_tls_set_cork;
+    ioc_klass->io_close = qio_channel_tls_close;
+    ioc_klass->io_shutdown = qio_channel_tls_shutdown;
+    ioc_klass->io_create_watch = qio_channel_tls_create_watch;
+}
+
+static const TypeInfo qio_channel_tls_info = {
+    .parent = TYPE_QIO_CHANNEL,
+    .name = TYPE_QIO_CHANNEL_TLS,
+    .instance_size = sizeof(QIOChannelTLS),
+    .instance_init = qio_channel_tls_init,
+    .instance_finalize = qio_channel_tls_finalize,
+    .class_init = qio_channel_tls_class_init,
+};
+
+static void qio_channel_tls_register_types(void)
+{
+    type_register_static(&qio_channel_tls_info);
+}
+
+type_init(qio_channel_tls_register_types);

io/channel-watch.c

+/*
+ * QEMU I/O channels watch helper APIs
+ *
+ * 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/>.
+ *
+ */
+
+#include "io/channel-watch.h"
+
+typedef struct QIOChannelFDSource QIOChannelFDSource;
+struct QIOChannelFDSource {
+    GSource parent;
+    GPollFD fd;
+    QIOChannel *ioc;
+    GIOCondition condition;
+};
+
+
+typedef struct QIOChannelFDPairSource QIOChannelFDPairSource;
+struct QIOChannelFDPairSource {
+    GSource parent;
+    GPollFD fdread;
+    GPollFD fdwrite;
+    QIOChannel *ioc;
+    GIOCondition condition;
+};
+
+
+static gboolean
+qio_channel_fd_source_prepare(GSource *source G_GNUC_UNUSED,
+                              gint *timeout)
+{
+    *timeout = -1;
+
+    return FALSE;
+}
+
+
+static gboolean
+qio_channel_fd_source_check(GSource *source)
+{
+    QIOChannelFDSource *ssource = (QIOChannelFDSource *)source;
+
+    return ssource->fd.revents & ssource->condition;
+}
+
+
+static gboolean
+qio_channel_fd_source_dispatch(GSource *source,
+                               GSourceFunc callback,
+                               gpointer user_data)
+{
+    QIOChannelFunc func = (QIOChannelFunc)callback;
+    QIOChannelFDSource *ssource = (QIOChannelFDSource *)source;
+
+    return (*func)(ssource->ioc,
+                   ssource->fd.revents & ssource->condition,
+                   user_data);
+}
+
+
+static void
+qio_channel_fd_source_finalize(GSource *source)
+{
+    QIOChannelFDSource *ssource = (QIOChannelFDSource *)source;
+
+    object_unref(OBJECT(ssource->ioc));
+}
+
+
+static gboolean
+qio_channel_fd_pair_source_prepare(GSource *source G_GNUC_UNUSED,
+                                   gint *timeout)
+{
+    *timeout = -1;
+
+    return FALSE;
+}
+
+
+static gboolean
+qio_channel_fd_pair_source_check(GSource *source)
+{
+    QIOChannelFDPairSource *ssource = (QIOChannelFDPairSource *)source;
+    GIOCondition poll_condition = ssource->fdread.revents |
+        ssource->fdwrite.revents;
+
+    return poll_condition & ssource->condition;
+}
+
+
+static gboolean
+qio_channel_fd_pair_source_dispatch(GSource *source,
+                                    GSourceFunc callback,
+                                    gpointer user_data)
+{
+    QIOChannelFunc func = (QIOChannelFunc)callback;
+    QIOChannelFDPairSource *ssource = (QIOChannelFDPairSource *)source;
+    GIOCondition poll_condition = ssource->fdread.revents |
+        ssource->fdwrite.revents;
+
+    return (*func)(ssource->ioc,
+                   poll_condition & ssource->condition,
+                   user_data);
+}
+
+
+static void
+qio_channel_fd_pair_source_finalize(GSource *source)
+{
+    QIOChannelFDPairSource *ssource = (QIOChannelFDPairSource *)source;
+
+    object_unref(OBJECT(ssource->ioc));
+}
+
+
+GSourceFuncs qio_channel_fd_source_funcs = {
+    qio_channel_fd_source_prepare,
+    qio_channel_fd_source_check,
+    qio_channel_fd_source_dispatch,
+    qio_channel_fd_source_finalize
+};
+
+
+GSourceFuncs qio_channel_fd_pair_source_funcs = {
+    qio_channel_fd_pair_source_prepare,
+    qio_channel_fd_pair_source_check,
+    qio_channel_fd_pair_source_dispatch,
+    qio_channel_fd_pair_source_finalize
+};
+
+
+GSource *qio_channel_create_fd_watch(QIOChannel *ioc,
+                                     int fd,
+                                     GIOCondition condition)
+{
+    GSource *source;
+    QIOChannelFDSource *ssource;
+
+    source = g_source_new(&qio_channel_fd_source_funcs,
+                          sizeof(QIOChannelFDSource));
+    ssource = (QIOChannelFDSource *)source;
+
+    ssource->ioc = ioc;
+    object_ref(OBJECT(ioc));
+
+    ssource->condition = condition;
+
+    ssource->fd.fd = fd;
+    ssource->fd.events = condition;
+
+    g_source_add_poll(source, &ssource->fd);
+
+    return source;
+}
+
+
+GSource *qio_channel_create_fd_pair_watch(QIOChannel *ioc,
+                                          int fdread,
+                                          int fdwrite,
+                                          GIOCondition condition)
+{
+    GSource *source;
+    QIOChannelFDPairSource *ssource;
+
+    source = g_source_new(&qio_channel_fd_pair_source_funcs,
+                          sizeof(QIOChannelFDPairSource));
+    ssource = (QIOChannelFDPairSource *)source;
+
+    ssource->ioc = ioc;
+    object_ref(OBJECT(ioc));
+
+    ssource->condition = condition;
+
+    ssource->fdread.fd = fdread;
+    ssource->fdread.events = condition & G_IO_IN;
+
+    ssource->fdwrite.fd = fdwrite;
+    ssource->fdwrite.events = condition & G_IO_OUT;
+
+    g_source_add_poll(source, &ssource->fdread);
+    g_source_add_poll(source, &ssource->fdwrite);
+
+    return source;
+}

io/task.c

+/*
+ * QEMU I/O task
+ *
+ * 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/>.
+ *
+ */
+
+#include "io/task.h"
+#include "qemu/thread.h"
+#include "trace.h"
+
+struct QIOTask {
+    Object *source;
+    QIOTaskFunc func;
+    gpointer opaque;
+    GDestroyNotify destroy;
+};
+
+
+QIOTask *qio_task_new(Object *source,
+                      QIOTaskFunc func,
+                      gpointer opaque,
+                      GDestroyNotify destroy)
+{
+    QIOTask *task;
+
+    task = g_new0(QIOTask, 1);
+
+    task->source = source;
+    object_ref(source);
+    task->func = func;
+    task->opaque = opaque;
+    task->destroy = destroy;
+
+    trace_qio_task_new(task, source, func, opaque);
+
+    return task;
+}
+
+static void qio_task_free(QIOTask *task)
+{
+    if (task->destroy) {
+        task->destroy(task->opaque);
+    }
+    object_unref(task->source);
+
+    g_free(task);
+}
+
+
+struct QIOTaskThreadData {
+    QIOTask *task;
+    QIOTaskWorker worker;
+    gpointer opaque;
+    GDestroyNotify destroy;
+    Error *err;
+    int ret;
+};
+
+
+static gboolean gio_task_thread_result(gpointer opaque)
+{
+    struct QIOTaskThreadData *data = opaque;
+
+    trace_qio_task_thread_result(data->task);
+    if (data->ret == 0) {
+        qio_task_complete(data->task);
+    } else {
+        qio_task_abort(data->task, data->err);
+    }
+
+    error_free(data->err);
+    if (data->destroy) {
+        data->destroy(data->opaque);
+    }
+
+    g_free(data);
+
+    return FALSE;
+}
+
+
+static gpointer qio_task_thread_worker(gpointer opaque)
+{
+    struct QIOTaskThreadData *data = opaque;
+
+    trace_qio_task_thread_run(data->task);
+    data->ret = data->worker(data->task, &data->err, data->opaque);
+    if (data->ret < 0 && data->err == NULL) {
+        error_setg(&data->err, "Task worker failed but did not set an error");
+    }
+
+    /* We're running in the background thread, and must only
+     * ever report the task results in the main event loop
+     * thread. So we schedule an idle callback to report
+     * the worker results
+     */
+    trace_qio_task_thread_exit(data->task);
+    g_idle_add(gio_task_thread_result, data);
+    return NULL;
+}
+
+
+void qio_task_run_in_thread(QIOTask *task,
+                            QIOTaskWorker worker,
+                            gpointer opaque,
+                            GDestroyNotify destroy)
+{
+    struct QIOTaskThreadData *data = g_new0(struct QIOTaskThreadData, 1);
+    QemuThread thread;
+
+    data->task = task;
+    data->worker = worker;
+    data->opaque = opaque;
+    data->destroy = destroy;
+
+    trace_qio_task_thread_start(task, worker, opaque);
+    qemu_thread_create(&thread,
+                       "io-task-worker",
+                       qio_task_thread_worker,
+                       data,
+                       QEMU_THREAD_DETACHED);
+}
+
+
+void qio_task_complete(QIOTask *task)
+{
+    task->func(task->source, NULL, task->opaque);
+    trace_qio_task_complete(task);
+    qio_task_free(task);
+}
+
+void qio_task_abort(QIOTask *task,
+                    Error *err)
+{
+    task->func(task->source, err, task->opaque);
+    trace_qio_task_abort(task);
+    qio_task_free(task);
+}
+
+
+Object *qio_task_get_source(QIOTask *task)
+{
+    object_ref(task->source);
+    return task->source;
+}

scripts/create_config

@@ -61,6 +61,15 @@ case $line in
     value=${line#*=}
     echo "#define $name $value"
     ;;
+ HAVE_*=y) # configuration
+    name=${line%=*}
+    echo "#define $name 1"
+    ;;
+ HAVE_*=*) # configuration
+    name=${line%=*}
+    value=${line#*=}
+    echo "#define $name $value"
+    ;;
  ARCH=*) # configuration
     arch=${line#*=}
     arch_name=`echo $arch | LC_ALL=C tr '[a-z]' '[A-Z]'`

tests/.gitignore

@@ -24,6 +24,14 @@ test-cutils
 test-hbitmap
 test-int128
 test-iov
+test-io-channel-buffer
+test-io-channel-command
+test-io-channel-command.fifo
+test-io-channel-file
+test-io-channel-file.txt
+test-io-channel-socket
+test-io-channel-tls
+test-io-task
 test-mul64
 test-opts-visitor
 test-qapi-event.[ch]

util/qemu-sockets.c

@@ -1086,7 +1086,7 @@ socket_sockaddr_to_address_unix(struct sockaddr_storage *sa,
 }
 #endif /* WIN32 */
 
-static SocketAddress *
+SocketAddress *
 socket_sockaddr_to_address(struct sockaddr_storage *sa,
                            socklen_t salen,
                            Error **errp)