[Qemu-devel] [PATCH FYI 10/46] io: add QIOChannelSocket class

["Daniel P. Berrange" <berrange@redhat.com>]

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

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 configure                      |  11 +
 include/io/channel-socket.h    | 297 +++++++++++++++++
 io/Makefile.objs               |   1 +
 io/channel-socket.c            | 718 +++++++++++++++++++++++++++++++++++++++++
 scripts/create_config          |   9 +
 tests/.gitignore               |   1 +
 tests/Makefile                 |   3 +
 tests/io-channel-helpers.c     | 222 +++++++++++++
 tests/io-channel-helpers.h     |  30 ++
 tests/test-io-channel-socket.c | 349 ++++++++++++++++++++
 10 files changed, 1641 insertions(+)
 create mode 100644 include/io/channel-socket.h
 create mode 100644 io/channel-socket.c
 create mode 100644 tests/io-channel-helpers.c
 create mode 100644 tests/io-channel-helpers.h
 create mode 100644 tests/test-io-channel-socket.c

diff --git a/configure b/configure
index 3dbb18f..f53adcd 100755
--- a/configure
+++ b/configure
@@ -2259,6 +2259,14 @@ 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
 
 if test "$vte" != "no"; then
@@ -4901,6 +4909,9 @@ fi
 if test "$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
diff --git a/include/io/channel-socket.h b/include/io/channel-socket.h
new file mode 100644
index 0000000..2d1e86a
--- /dev/null
+++ b/include/io/channel-socket.h
@@ -0,0 +1,297 @@
+/*
+ * 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_set_nodelay:
+ * @ioc: the socket channel object
+ * @enabled: the new flag state
+ *
+ * Set the state of the TCP_NODELAY socket flag. If the
+ * @enabled parameter is true, then TCP_NODELAY will be
+ * set and data will be transmitted immediately. If
+ * @enabled is false, then data may be temporarily
+ * held for transmission to enable writes to be
+ * coallesced.
+ */
+void
+qio_channel_socket_set_nodelay(QIOChannelSocket *ioc,
+                               bool enabled);
+
+/**
+ * qio_channel_socket_set_cork:
+ * @ioc: the socket channel object
+ * @enabled: the new flag state
+ *
+ * Set the state of the TCP_CORK socket flag. If the
+ * @enabled parameter is true, then TCP_CORK will be
+ * set and data will be not be transmitted immediately.
+ * If @enabled is false, then any previously queued
+ * data is released for transmission. This method is
+ * useful when the TCP_NODELAY flag is enabled to have
+ * direct control over transmission times.
+ */
+void
+qio_channel_socket_set_cork(QIOChannelSocket *ioc,
+                            bool enabled);
+
+/**
+ * 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);
+
+typedef enum {
+    QIO_CHANNEL_SOCKET_SHUTDOWN_BOTH,
+    QIO_CHANNEL_SOCKET_SHUTDOWN_READ,
+    QIO_CHANNEL_SOCKET_SHUTDOWN_WRITE,
+} QIOChannelSocketShutdown;
+
+/**
+ * qio_channel_socket_shutdown:
+ * @ioc: the socket channel object
+ * @how: the direction to shutdown
+ * @errp: pointer to an uninitialized error object
+ *
+ * Shutdowns transmission or receiving on a socket
+ * without closing the socket file descriptor.
+ *
+ * Returns: 0 on success, -1 on error
+ */
+int
+qio_channel_socket_shutdown(QIOChannelSocket *ioc,
+                            QIOChannelSocketShutdown how,
+                            Error **errp);
+
+#endif /* QIO_CHANNEL_SOCKET_H__ */
diff --git a/io/Makefile.objs b/io/Makefile.objs
index bef2ca1..f12ec26 100644
--- a/io/Makefile.objs
+++ b/io/Makefile.objs
@@ -2,3 +2,4 @@ io-obj-y = buffer.o
 io-obj-y += task.o
 io-obj-y += channel.o
 io-obj-y += channel-watch.o
+io-obj-y += channel-socket.o
diff --git a/io/channel-socket.c b/io/channel-socket.c
new file mode 100644
index 0000000..0b28a00
--- /dev/null
+++ b/io/channel-socket.c
@@ -0,0 +1,718 @@
+/*
+ * 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/>.
+ *
+ */
+
+#include <glib/gi18n.h>
+
+#include "io/channel-socket.h"
+#include "io/channel-watch.h"
+
+#define SOCKET_MAX_FDS 16
+
+SocketAddress *
+qio_channel_socket_get_local_address(QIOChannelSocket *ioc,
+                                     Error **errp)
+{
+    return socket_local_address(ioc->fd, errp);
+}
+
+SocketAddress *
+qio_channel_socket_get_remote_address(QIOChannelSocket *ioc,
+                                      Error **errp)
+{
+    return socket_remote_address(ioc->fd, errp);
+}
+
+QIOChannelSocket *
+qio_channel_socket_new(void)
+{
+    QIOChannelSocket *ioc;
+
+    ioc = QIO_CHANNEL_SOCKET(object_new(TYPE_QIO_CHANNEL_SOCKET));
+    ioc->fd = -1;
+
+    return ioc;
+}
+
+
+static int
+qio_channel_socket_set_fd(QIOChannelSocket *ioc,
+                          int fd,
+                          Error **errp)
+{
+    if (ioc->fd != -1) {
+        error_setg(errp, _("Socket is already open"));
+        return -1;
+    }
+
+    ioc->fd = fd;
+    ioc->remoteAddrLen = sizeof(ioc->remoteAddr);
+    ioc->localAddrLen = sizeof(ioc->localAddr);
+
+    if (getpeername(fd, (struct sockaddr *)&ioc->remoteAddr,
+                    &ioc->remoteAddrLen) < 0) {
+        if (socket_error() == ENOTCONN) {
+            memset(&ioc->remoteAddr, 0, sizeof(ioc->remoteAddr));
+            ioc->remoteAddrLen = sizeof(ioc->remoteAddr);
+        } else {
+            error_setg_errno(errp, socket_error(), "%s",
+                             _("Unable to query remote socket address"));
+            goto error;
+        }
+    }
+
+    if (getsockname(fd, (struct sockaddr *)&ioc->localAddr,
+                    &ioc->localAddrLen) < 0) {
+        error_setg_errno(errp, socket_error(), "%s",
+                         _("Unable to query local socket address"));
+        goto error;
+    }
+
+    return 0;
+
+ error:
+    ioc->fd = -1; /* Let the caller close FD on failure */
+    return -1;
+}
+
+QIOChannelSocket *
+qio_channel_socket_new_fd(int fd,
+                          Error **errp)
+{
+    QIOChannelSocket *ioc;
+
+    ioc = qio_channel_socket_new();
+    if (qio_channel_socket_set_fd(ioc, fd, errp) < 0) {
+        object_unref(OBJECT(ioc));
+        return NULL;
+    }
+
+    return ioc;
+}
+
+
+int qio_channel_socket_connect_sync(QIOChannelSocket *ioc,
+                                    SocketAddress *addr,
+                                    Error **errp)
+{
+    int fd;
+
+    fd = socket_connect(addr, errp, NULL, NULL);
+    if (fd < 0) {
+        return -1;
+    }
+
+    if (qio_channel_socket_set_fd(ioc, fd, errp) < 0) {
+        close(fd);
+        return -1;
+    }
+
+    return 0;
+}
+
+
+static int qio_channel_socket_connect_worker(QIOTask *task,
+                                             Error **errp,
+                                             gpointer opaque)
+{
+    QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(qio_task_get_source(task));
+    SocketAddress *addr = opaque;
+
+    return qio_channel_socket_connect_sync(ioc,
+                                           addr,
+                                           errp);
+}
+
+
+void qio_channel_socket_connect_async(QIOChannelSocket *ioc,
+                                      SocketAddress *addr,
+                                      QIOTaskFunc callback,
+                                      gpointer opaque,
+                                      GDestroyNotify destroy)
+{
+    QIOTask *task = qio_task_new(
+        OBJECT(ioc), callback, opaque, destroy);
+    SocketAddress *addrCopy;
+
+    qapi_copy_SocketAddress(&addrCopy, addr);
+
+    /* socket_connect() does a non-blocking connect(), but it
+     * still blocks in DNS lookups, so we must use a thread */
+    qio_task_run_in_thread(task,
+                           qio_channel_socket_connect_worker,
+                           addrCopy,
+                           (GDestroyNotify)qapi_free_SocketAddress);
+}
+
+
+int qio_channel_socket_listen_sync(QIOChannelSocket *ioc,
+                                   SocketAddress *addr,
+                                   Error **errp)
+{
+    int fd;
+
+    fd = socket_listen(addr, errp);
+    if (fd < 0) {
+        return -1;
+    }
+
+    if (qio_channel_socket_set_fd(ioc, fd, errp) < 0) {
+        close(fd);
+        return -1;
+    }
+
+    return 0;
+}
+
+
+static int qio_channel_socket_listen_worker(QIOTask *task,
+                                            Error **errp,
+                                            gpointer opaque)
+{
+    QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(qio_task_get_source(task));
+    SocketAddress *addr = opaque;
+
+    return qio_channel_socket_listen_sync(ioc,
+                                          addr,
+                                          errp);
+}
+
+
+void qio_channel_socket_listen_async(QIOChannelSocket *ioc,
+                                     SocketAddress *addr,
+                                     QIOTaskFunc callback,
+                                     gpointer opaque,
+                                     GDestroyNotify destroy)
+{
+    QIOTask *task = qio_task_new(
+        OBJECT(ioc), callback, opaque, destroy);
+    SocketAddress *addrCopy;
+
+    qapi_copy_SocketAddress(&addrCopy, addr);
+
+    /* socket_listen() blocks in DNS lookups, so we must use a thread */
+    qio_task_run_in_thread(task,
+                           qio_channel_socket_listen_worker,
+                           addrCopy,
+                           (GDestroyNotify)qapi_free_SocketAddress);
+}
+
+
+int qio_channel_socket_dgram_sync(QIOChannelSocket *ioc,
+                                  SocketAddress *localAddr,
+                                  SocketAddress *remoteAddr,
+                                  Error **errp)
+{
+    int fd;
+
+    fd = socket_dgram(localAddr, remoteAddr, errp);
+    if (fd < 0) {
+        return -1;
+    }
+
+    if (qio_channel_socket_set_fd(ioc, fd, errp) < 0) {
+        close(fd);
+        return -1;
+    }
+
+    return 0;
+}
+
+
+struct QIOChannelSocketDGramWorkerData {
+    SocketAddress *localAddr;
+    SocketAddress *remoteAddr;
+};
+
+
+static void qio_channel_socket_dgram_worker_free(gpointer opaque)
+{
+    struct QIOChannelSocketDGramWorkerData *data = opaque;
+    qapi_free_SocketAddress(data->localAddr);
+    qapi_free_SocketAddress(data->remoteAddr);
+    g_free(data);
+}
+
+static int qio_channel_socket_dgram_worker(QIOTask *task,
+                                           Error **errp,
+                                           gpointer opaque)
+{
+    QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(qio_task_get_source(task));
+    struct QIOChannelSocketDGramWorkerData *data = opaque;
+
+    /* socket_dgram() blocks in DNS lookups, so we must use a thread */
+    return qio_channel_socket_dgram_sync(ioc,
+                                         data->localAddr,
+                                         data->remoteAddr,
+                                         errp);
+}
+
+
+void qio_channel_socket_dgram_async(QIOChannelSocket *ioc,
+                                    SocketAddress *localAddr,
+                                    SocketAddress *remoteAddr,
+                                    QIOTaskFunc callback,
+                                    gpointer opaque,
+                                    GDestroyNotify destroy)
+{
+    QIOTask *task = qio_task_new(
+        OBJECT(ioc), callback, opaque, destroy);
+    struct QIOChannelSocketDGramWorkerData *data = g_new0(
+        struct QIOChannelSocketDGramWorkerData, 1);
+
+    qapi_copy_SocketAddress(&data->localAddr, localAddr);
+    qapi_copy_SocketAddress(&data->remoteAddr, remoteAddr);
+
+    qio_task_run_in_thread(task,
+                           qio_channel_socket_dgram_worker,
+                           data,
+                           qio_channel_socket_dgram_worker_free);
+}
+
+
+QIOChannelSocket *
+qio_channel_socket_accept(QIOChannelSocket *ioc,
+                          Error **errp)
+{
+    QIOChannelSocket *cioc;
+
+    cioc = QIO_CHANNEL_SOCKET(object_new(TYPE_QIO_CHANNEL_SOCKET));
+    cioc->fd = -1;
+    cioc->remoteAddrLen = sizeof(ioc->remoteAddr);
+    cioc->localAddrLen = sizeof(ioc->localAddr);
+
+ retry:
+    cioc->fd = accept(ioc->fd, (struct sockaddr *)&cioc->remoteAddr,
+                      &cioc->remoteAddrLen);
+    if (cioc->fd < 0) {
+        if (socket_error() == EINTR) {
+            goto retry;
+        }
+        goto error;
+    }
+
+    if (getsockname(cioc->fd, (struct sockaddr *)&ioc->localAddr,
+                    &ioc->localAddrLen) < 0) {
+        error_setg_errno(errp, socket_error(), "%s",
+                         _("Unable to query local socket address"));
+        goto error;
+    }
+
+    return cioc;
+
+ error:
+    object_unref(OBJECT(cioc));
+    return NULL;
+}
+
+static void qio_channel_socket_init(Object *obj)
+{
+    QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(obj);
+    ioc->fd = -1;
+}
+
+static void qio_channel_socket_finalize(Object *obj)
+{
+    QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(obj);
+    if (ioc->fd != -1) {
+        close(ioc->fd);
+        ioc->fd = -1;
+    }
+}
+
+static bool qio_channel_socket_has_feature(QIOChannel *ioc,
+                                           QIOChannelFeature feature)
+{
+#ifndef WIN32
+    QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
+
+    switch (feature) {
+    case QIO_CHANNEL_FEATURE_FD_PASS:
+        if (sioc->localAddr.ss_family == AF_UNIX) {
+            return true;
+        } else {
+            return false;
+        }
+    default:
+        return false;
+    }
+#else
+    return false;
+#endif
+}
+
+
+#ifndef WIN32
+static void qio_channel_socket_copy_fds(struct msghdr *msg,
+                                        int **fds, size_t *nfds)
+{
+    struct cmsghdr *cmsg;
+
+    *nfds = 0;
+    *fds = NULL;
+
+    for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
+        int fd_size, i;
+        int gotfds;
+
+        if (cmsg->cmsg_len < CMSG_LEN(sizeof(int)) ||
+            cmsg->cmsg_level != SOL_SOCKET ||
+            cmsg->cmsg_type != SCM_RIGHTS) {
+            continue;
+        }
+
+        fd_size = cmsg->cmsg_len - CMSG_LEN(0);
+
+        if (!fd_size) {
+            continue;
+        }
+
+        gotfds = fd_size / sizeof(int);
+        *fds = g_renew(int, *fds, *nfds + gotfds);
+        memcpy(*fds + *nfds, CMSG_DATA(cmsg), fd_size);
+
+        for (i = 0; i < gotfds; i++) {
+            int fd = (*fds)[*nfds + i];
+            if (fd < 0) {
+                continue;
+            }
+
+            /* O_NONBLOCK is preserved across SCM_RIGHTS so reset it */
+            qemu_set_block(fd);
+
+#ifndef MSG_CMSG_CLOEXEC
+            qemu_set_cloexec(fd);
+#endif
+        }
+        *nfds += gotfds;
+    }
+}
+
+
+static ssize_t qio_channel_socket_readv(QIOChannel *ioc,
+                                        const struct iovec *iov,
+                                        size_t niov,
+                                        int **fds,
+                                        size_t *nfds,
+                                        Error **errp)
+{
+    QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
+    ssize_t ret;
+    struct msghdr msg = { NULL, };
+    char control[CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS)];
+    int sflags = 0;
+
+#ifdef MSG_CMSG_CLOEXEC
+    sflags |= MSG_CMSG_CLOEXEC;
+#endif
+
+    msg.msg_iov = (struct iovec *)iov;
+    msg.msg_iovlen = niov;
+    if (fds && nfds) {
+        msg.msg_control = control;
+        msg.msg_controllen = sizeof(control);
+    }
+
+ retry:
+    ret = recvmsg(sioc->fd, &msg, sflags);
+    if (ret < 0) {
+        if (socket_error() == EAGAIN ||
+            socket_error() == EWOULDBLOCK) {
+            return QIO_CHANNEL_ERR_BLOCK;
+        }
+        if (socket_error() == EINTR) {
+            goto retry;
+        }
+
+        error_setg_errno(errp, socket_error(), "%s",
+                         _("Unable to read from socket"));
+        return -1;
+    }
+
+    if (fds && nfds) {
+        qio_channel_socket_copy_fds(&msg, fds, nfds);
+    }
+
+    return ret;
+}
+
+static ssize_t qio_channel_socket_writev(QIOChannel *ioc,
+                                         const struct iovec *iov,
+                                         size_t niov,
+                                         int *fds,
+                                         size_t nfds,
+                                         Error **errp)
+{
+    QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
+    ssize_t ret;
+    struct msghdr msg = { NULL, };
+
+    msg.msg_iov = (struct iovec *)iov;
+    msg.msg_iovlen = niov;
+
+    if (nfds) {
+        char control[CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS)];
+        size_t fdsize = sizeof(int) * nfds;
+        struct cmsghdr *cmsg;
+
+        if (nfds > SOCKET_MAX_FDS) {
+            error_setg_errno(errp, -EINVAL,
+                             _("Only %d FDs can be sent, got %zu"),
+                             SOCKET_MAX_FDS, nfds);
+            return -1;
+        }
+
+        msg.msg_control = control;
+        msg.msg_controllen = CMSG_SPACE(sizeof(int) * nfds);
+
+        cmsg = CMSG_FIRSTHDR(&msg);
+        cmsg->cmsg_len = CMSG_LEN(fdsize);
+        cmsg->cmsg_level = SOL_SOCKET;
+        cmsg->cmsg_type = SCM_RIGHTS;
+        memcpy(CMSG_DATA(cmsg), fds, fdsize);
+    }
+
+ retry:
+    ret = sendmsg(sioc->fd, &msg, 0);
+    if (ret <= 0) {
+        if (socket_error() == EAGAIN ||
+            socket_error() == EWOULDBLOCK) {
+            return QIO_CHANNEL_ERR_BLOCK;
+        }
+        if (socket_error() == EINTR) {
+            goto retry;
+        }
+        error_setg_errno(errp, socket_error(), "%s",
+                         _("Unable to write to socket"));
+        return -1;
+    }
+    return ret;
+}
+#else /* WIN32 */
+static ssize_t qio_channel_socket_readv(QIOChannel *ioc,
+                                        const struct iovec *iov,
+                                        size_t niov,
+                                        int **fds,
+                                        size_t *nfds,
+                                        Error **errp)
+{
+    QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
+    ssize_t done = 0;
+    ssize_t i;
+
+    if (fds || nfds) {
+        error_setg_errno(errp, EINVAL, "%s",
+                         _("Channel does not support file descriptor passing"));
+        return -1;
+    }
+
+    for (i = 0; i < niov; i++) {
+        ssize_t ret;
+    retry:
+        ret = recv(sioc->fd,
+                   iov[i].iov_base,
+                   iov[i].iov_len,
+                   0);
+        if (ret < 0) {
+            if (socket_error() == EAGAIN) {
+                if (done) {
+                    return done;
+                } else {
+                    return QIO_CHANNEL_ERR_BLOCK;
+                }
+            } else if (socket_error() == EINTR) {
+                goto retry;
+            } else {
+                error_setg_errno(errp, socket_error(), "%s",
+                                 _("Unable to write to socket"));
+                return -1;
+            }
+        }
+        done += ret;
+        if (ret < iov[i].iov_len) {
+            return done;
+        }
+    }
+
+    return done;
+}
+
+static ssize_t qio_channel_socket_writev(QIOChannel *ioc,
+                                         const struct iovec *iov,
+                                         size_t niov,
+                                         int *fds,
+                                         size_t nfds,
+                                         Error **errp)
+{
+    QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
+    ssize_t done = 0;
+    ssize_t i;
+
+    if (fds || nfds) {
+        error_setg_errno(errp, EINVAL, "%s",
+                         _("Channel does not support file descriptor passing"));
+        return -1;
+    }
+
+    for (i = 0; i < niov; i++) {
+        ssize_t ret;
+    retry:
+        ret = send(sioc->fd,
+                   iov[i].iov_base,
+                   iov[i].iov_len,
+                   0);
+        if (ret < 0) {
+            if (socket_error() == EAGAIN) {
+                if (done) {
+                    return done;
+                } else {
+                    return QIO_CHANNEL_ERR_BLOCK;
+                }
+            } else if (socket_error() == EINTR) {
+                goto retry;
+            } else {
+                error_setg_errno(errp, socket_error(), "%s",
+                                 _("Unable to write to socket"));
+                return -1;
+            }
+        }
+        done += ret;
+        if (ret < iov[i].iov_len) {
+            return done;
+        }
+    }
+
+    return done;
+}
+#endif /* WIN32 */
+
+static void qio_channel_socket_set_blocking(QIOChannel *ioc,
+                                            bool enabled)
+{
+    QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
+
+    if (enabled) {
+        qemu_set_block(sioc->fd);
+    } else {
+        qemu_set_nonblock(sioc->fd);
+    }
+}
+
+
+void
+qio_channel_socket_set_nodelay(QIOChannelSocket *ioc,
+                               bool enabled)
+{
+    QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
+    int v = enabled ? 1 : 0;
+
+    qemu_setsockopt(sioc->fd, IPPROTO_TCP, TCP_NODELAY, &v, sizeof(v));
+}
+
+
+void
+qio_channel_socket_set_cork(QIOChannelSocket *ioc,
+                            bool enabled)
+{
+    QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
+    int v = enabled ? 1 : 0;
+
+    socket_set_cork(sioc->fd, v);
+}
+
+
+static int qio_channel_socket_close(QIOChannel *ioc,
+                                    Error **errp)
+{
+    QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
+
+    if (closesocket(sioc->fd) < 0) {
+        sioc->fd = -1;
+        error_setg_errno(errp, socket_error(), "%s",
+                         _("Unable to close socket"));
+        return -1;
+    }
+    sioc->fd = -1;
+    return 0;
+}
+
+int
+qio_channel_socket_shutdown(QIOChannelSocket *ioc,
+                            QIOChannelSocketShutdown how,
+                            Error **errp)
+{
+    int sockhow;
+    switch (how) {
+    case QIO_CHANNEL_SOCKET_SHUTDOWN_READ:
+        sockhow = SHUT_RD;
+        break;
+    case QIO_CHANNEL_SOCKET_SHUTDOWN_WRITE:
+        sockhow = SHUT_WR;
+        break;
+    case QIO_CHANNEL_SOCKET_SHUTDOWN_BOTH:
+    default:
+        sockhow = SHUT_RDWR;
+        break;
+    }
+
+    if (shutdown(ioc->fd, sockhow) < 0) {
+        error_setg_errno(errp, socket_error(), "%s",
+                         _("Unable to shutdown socket"));
+        return -1;
+    }
+    return 0;
+}
+
+static GSource *qio_channel_socket_create_watch(QIOChannel *ioc,
+                                                GIOCondition condition)
+{
+    QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
+    return qio_channel_create_fd_watch(ioc,
+                                       sioc->fd,
+                                       condition);
+}
+
+static void qio_channel_socket_class_init(ObjectClass *klass,
+                                          void *class_data G_GNUC_UNUSED)
+{
+    QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
+
+    ioc_klass->io_has_feature = qio_channel_socket_has_feature;
+    ioc_klass->io_writev = qio_channel_socket_writev;
+    ioc_klass->io_readv = qio_channel_socket_readv;
+    ioc_klass->io_set_blocking = qio_channel_socket_set_blocking;
+    ioc_klass->io_close = qio_channel_socket_close;
+    ioc_klass->io_create_watch = qio_channel_socket_create_watch;
+}
+
+static const TypeInfo qio_channel_socket_info = {
+    .parent = TYPE_QIO_CHANNEL,
+    .name = TYPE_QIO_CHANNEL_SOCKET,
+    .instance_size = sizeof(QIOChannelSocket),
+    .instance_init = qio_channel_socket_init,
+    .instance_finalize = qio_channel_socket_finalize,
+    .class_init = qio_channel_socket_class_init,
+};
+
+static void qio_channel_socket_register_types(void)
+{
+    type_register_static(&qio_channel_socket_info);
+}
+
+type_init(qio_channel_socket_register_types);
diff --git a/scripts/create_config b/scripts/create_config
index 546f889..9cb176f 100755
--- a/scripts/create_config
+++ b/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 $arch | LC_ALL=C tr '[a-z]' '[A-Z]'`
diff --git a/tests/.gitignore b/tests/.gitignore
index 6269480..ac891c6 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -23,6 +23,7 @@ test-cutils
 test-hbitmap
 test-int128
 test-iov
+test-io-channel-socket
 test-io-task
 test-mul64
 test-opts-visitor
diff --git a/tests/Makefile b/tests/Makefile
index 3b7f5a6..37bde1a 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -79,6 +79,7 @@ check-unit-y += tests/test-crypto-cipher$(EXESUF)
 check-unit-$(CONFIG_GNUTLS) += tests/test-crypto-tlscredsx509$(EXESUF)
 check-unit-$(CONFIG_GNUTLS) += tests/test-crypto-tlssession$(EXESUF)
 check-unit-y += tests/test-io-task$(EXESUF)
+check-unit-y += tests/test-io-channel-socket$(EXESUF)
 
 check-block-$(CONFIG_POSIX) += tests/qemu-iotests-quick.sh
 
@@ -360,6 +361,8 @@ tests/test-crypto-tlscredsx509$(EXESUF): tests/test-crypto-tlscredsx509.o \
 tests/test-crypto-tlssession$(EXESUF): tests/test-crypto-tlssession.o \
 	tests/crypto-tls-x509-helpers.o tests/pkix_asn1_tab.o $(test-crypto-obj-y)
 tests/test-io-task$(EXESUF): tests/test-io-task.o $(test-io-obj-y)
+tests/test-io-channel-socket$(EXESUF): tests/test-io-channel-socket.o \
+        tests/io-channel-helpers.o $(test-io-obj-y)
 
 libqos-obj-y = tests/libqos/pci.o tests/libqos/fw_cfg.o tests/libqos/malloc.o
 libqos-obj-y += tests/libqos/i2c.o tests/libqos/libqos.o
diff --git a/tests/io-channel-helpers.c b/tests/io-channel-helpers.c
new file mode 100644
index 0000000..946c9b9
--- /dev/null
+++ b/tests/io-channel-helpers.c
@@ -0,0 +1,222 @@
+/*
+ * QEMU I/O channel test helpers
+ *
+ * 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-helpers.h"
+
+struct TestIOData {
+    QIOChannel *src;
+    QIOChannel *dst;
+    bool blocking;
+    size_t len;
+    size_t niov;
+    char *input;
+    struct iovec *inputv;
+    char *output;
+    struct iovec *outputv;
+    Error *writeerr;
+    Error *readerr;
+};
+
+
+static void test_skip_iovec(struct iovec **iov,
+                            size_t *niov,
+                            size_t skip,
+                            struct iovec *old)
+{
+    size_t offset = 0;
+    size_t i;
+
+    for (i = 0; i < *niov; i++) {
+        if (skip < (*iov)[i].iov_len) {
+            old->iov_len = (*iov)[i].iov_len;
+            old->iov_base = (*iov)[i].iov_base;
+
+            (*iov)[i].iov_len -= skip;
+            (*iov)[i].iov_base += skip;
+            break;
+        } else {
+            skip -= (*iov)[i].iov_len;
+
+            if (i == 0 && old->iov_base) {
+                (*iov)[i].iov_len = old->iov_len;
+                (*iov)[i].iov_base = old->iov_base;
+                old->iov_len = 0;
+                old->iov_base = NULL;
+            }
+
+            offset++;
+        }
+    }
+
+    *iov = *iov + offset;
+    *niov -= offset;
+}
+
+
+/* This thread sends all data using iovecs */
+static gpointer test_io_thread_writer(gpointer opaque)
+{
+    struct TestIOData *data = opaque;
+    struct iovec *iov = data->inputv;
+    size_t niov = data->niov;
+    struct iovec old = { 0 };
+
+    qio_channel_set_blocking(data->src, data->blocking);
+
+    while (niov) {
+        ssize_t ret;
+        ret = qio_channel_writev(data->src,
+                                 iov,
+                                 niov,
+                                 &data->writeerr);
+        if (ret == QIO_CHANNEL_ERR_BLOCK) {
+            if (data->blocking) {
+                error_setg(&data->writeerr,
+                           "Unexpected I/O blocking");
+                break;
+            } else {
+                qio_channel_wait(data->src,
+                                 G_IO_OUT);
+                continue;
+            }
+        } else if (ret < 0) {
+            break;
+        } else if (ret == 0) {
+            error_setg(&data->writeerr,
+                       "Unexpected zero length write");
+            break;
+        }
+
+        test_skip_iovec(&iov, &niov, ret, &old);
+    }
+
+    return NULL;
+}
+
+
+/* This thread receives all data using iovecs */
+static gpointer test_io_thread_reader(gpointer opaque)
+{
+    struct TestIOData *data = opaque;
+    struct iovec *iov = data->outputv;
+    size_t niov = data->niov;
+    struct iovec old = { 0 };
+
+    qio_channel_set_blocking(data->dst, data->blocking);
+
+    while (niov) {
+        ssize_t ret;
+
+        ret = qio_channel_readv(data->dst,
+                                iov,
+                                niov,
+                                &data->readerr);
+
+        if (ret == QIO_CHANNEL_ERR_BLOCK) {
+            if (data->blocking) {
+                error_setg(&data->writeerr,
+                           "Unexpected I/O blocking");
+                break;
+            } else {
+                qio_channel_wait(data->dst,
+                                 G_IO_IN);
+                continue;
+            }
+        } else if (ret < 0) {
+            break;
+        } else if (ret == 0) {
+            break;
+        }
+
+        test_skip_iovec(&iov, &niov, ret, &old);
+    }
+
+    return NULL;
+}
+
+
+static struct TestIOData *test_load_io_data(const char *filename)
+{
+    struct TestIOData *data = g_new0(struct TestIOData, 1);
+    GError *err = NULL;
+    size_t offset;
+    size_t i;
+
+#define IOVEC_LEN (64 * 1024)
+
+    if (!g_file_get_contents(filename, &data->input, &data->len, &err)) {
+        g_printerr("Unable to load file: %s\n", err->message);
+        abort();
+    }
+    data->len++; /* So that we send the trailing \0 too */
+    data->output = g_new0(gchar, data->len);
+
+    data->niov = (data->len / IOVEC_LEN) + 1;
+    data->inputv = g_new0(struct iovec, data->niov);
+    data->outputv = g_new0(struct iovec, data->niov);
+
+    for (i = 0, offset = 0; i < data->niov; i++, offset += IOVEC_LEN) {
+        data->inputv[i].iov_base = data->input + offset;
+        data->outputv[i].iov_base = data->output + offset;
+        if ((data->len - offset) > IOVEC_LEN) {
+            data->inputv[i].iov_len = IOVEC_LEN;
+            data->outputv[i].iov_len = IOVEC_LEN;
+        } else {
+            data->inputv[i].iov_len = data->len - offset;
+            data->outputv[i].iov_len = data->len - offset;
+        }
+    }
+
+    return data;
+}
+
+
+void test_io_channel_comms(bool blocking,
+                           QIOChannel *src,
+                           QIOChannel *dst)
+{
+    struct TestIOData *data;
+    GThread *reader, *writer;
+
+    data = test_load_io_data("libqemuutil.a");
+    data->src = src;
+    data->dst = dst;
+    data->blocking = blocking;
+
+    reader = g_thread_new("reader",
+                          test_io_thread_reader,
+                          data);
+    writer = g_thread_new("writer",
+                          test_io_thread_writer,
+                          data);
+
+    g_thread_join(reader);
+    g_thread_join(writer);
+
+    g_assert_cmpint(memcmp(data->input,
+                           data->output,
+                           data->len), ==, 0);
+    g_assert(data->readerr == NULL);
+    g_assert(data->writeerr == NULL);
+
+    g_free(data->input);
+    g_free(data->output);
+    g_free(data);
+}
diff --git a/tests/io-channel-helpers.h b/tests/io-channel-helpers.h
new file mode 100644
index 0000000..d0085a2
--- /dev/null
+++ b/tests/io-channel-helpers.h
@@ -0,0 +1,30 @@
+/*
+ * QEMU I/O channel test helpers
+ *
+ * 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.h"
+
+#ifndef TEST_IO_CHANNEL_HELPERS
+#define TEST_IO_CHANNEL_HELPERS
+
+void test_io_channel_comms(bool blocking,
+                           QIOChannel *src,
+                           QIOChannel *dst);
+
+#endif /* TEST_IO_CHANNEL_HELPERS */
diff --git a/tests/test-io-channel-socket.c b/tests/test-io-channel-socket.c
new file mode 100644
index 0000000..338f816
--- /dev/null
+++ b/tests/test-io-channel-socket.c
@@ -0,0 +1,349 @@
+/*
+ * QEMU I/O channel sockets test
+ *
+ * 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-socket.h"
+#include "io-channel-helpers.h"
+#ifdef HAVE_IFADDRS_H
+#include <ifaddrs.h>
+#endif
+
+static int check_protocol_support(bool *has_ipv4, bool *has_ipv6)
+{
+#ifdef HAVE_IFADDRS_H
+    struct ifaddrs *ifaddr = NULL, *ifa;
+    struct addrinfo hints = { 0 };
+    struct addrinfo *ai = NULL;
+    int gaierr;
+
+    *has_ipv4 = *has_ipv6 = false;
+
+    if (getifaddrs(&ifaddr) < 0) {
+        g_printerr("Failed to lookup interface addresses: %s\n",
+                   strerror(errno));
+        return -1;
+    }
+
+    for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
+        if (!ifa->ifa_addr)
+            continue;
+
+        if (ifa->ifa_addr->sa_family == AF_INET)
+            *has_ipv4 = true;
+        if (ifa->ifa_addr->sa_family == AF_INET6)
+            *has_ipv6 = true;
+    }
+
+    freeifaddrs(ifaddr);
+
+    hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
+    hints.ai_family = AF_INET6;
+    hints.ai_socktype = SOCK_STREAM;
+
+    if ((gaierr = getaddrinfo("::1", NULL, &hints, &ai)) != 0) {
+        if (gaierr == EAI_ADDRFAMILY ||
+            gaierr == EAI_FAMILY ||
+            gaierr == EAI_NONAME) {
+            *has_ipv6 = false;
+        } else {
+            g_printerr("Failed to resolve ::1 address: %s\n",
+                       gai_strerror(gaierr));
+            return -1;
+        }
+    }
+
+    freeaddrinfo(ai);
+
+    return 0;
+#else
+    *has_ipv4 = *has_ipv6 = false;
+
+    return -1;
+#endif
+}
+
+
+static void test_io_channel_set_socket_bufs(QIOChannel *src,
+                                            QIOChannel *dst)
+{
+    int buflen = 64 * 1024;
+
+    /*
+     * Make the socket buffers small so that we see
+     * the effects of partial reads/writes
+     */
+    setsockopt(((QIOChannelSocket *)src)->fd,
+               SOL_SOCKET, SO_SNDBUF,
+               (char *)&buflen,
+               sizeof(buflen));
+
+    setsockopt(((QIOChannelSocket *)dst)->fd,
+               SOL_SOCKET, SO_SNDBUF,
+               (char *)&buflen,
+               sizeof(buflen));
+}
+
+
+static void test_io_channel_setup_sync(SocketAddress *listen_addr,
+                                       SocketAddress *connect_addr,
+                                       QIOChannel **src,
+                                       QIOChannel **dst)
+{
+    QIOChannelSocket *lioc;
+
+    lioc = qio_channel_socket_new();
+    qio_channel_socket_listen_sync(lioc, listen_addr, &error_abort);
+
+    if (listen_addr->kind == SOCKET_ADDRESS_KIND_INET) {
+        SocketAddress *laddr = qio_channel_socket_get_local_address(
+            lioc, &error_abort);
+
+        connect_addr->inet->port = g_strdup(laddr->inet->port);
+
+        qapi_free_SocketAddress(laddr);
+    }
+
+    *src = QIO_CHANNEL(qio_channel_socket_new());
+    qio_channel_socket_connect_sync(
+        QIO_CHANNEL_SOCKET(*src), connect_addr, &error_abort);
+    qio_channel_socket_set_nodelay(QIO_CHANNEL_SOCKET(*src), true);
+
+    *dst = QIO_CHANNEL(qio_channel_socket_accept(lioc, &error_abort));
+    g_assert(*dst);
+
+    test_io_channel_set_socket_bufs(*src, *dst);
+
+    object_unref(OBJECT(lioc));
+}
+
+
+struct TestIOChannelData {
+    bool err;
+    GMainLoop *loop;
+};
+
+
+static void test_io_channel_complete(Object *src,
+                                     Error *err,
+                                     gpointer opaque)
+{
+    struct TestIOChannelData *data = opaque;
+    data->err = err != NULL;
+    g_main_loop_quit(data->loop);
+}
+
+
+static void test_io_channel_setup_async(SocketAddress *listen_addr,
+                                        SocketAddress *connect_addr,
+                                        QIOChannel **src,
+                                        QIOChannel **dst)
+{
+    QIOChannelSocket *lioc;
+    struct TestIOChannelData data;
+
+    data.loop = g_main_loop_new(g_main_context_default(),
+                                TRUE);
+
+    lioc = qio_channel_socket_new();
+    qio_channel_socket_listen_async(
+        lioc, listen_addr,
+        test_io_channel_complete, &data, NULL);
+
+    g_main_loop_run(data.loop);
+
+    g_assert(!data.err);
+
+    if (listen_addr->kind == SOCKET_ADDRESS_KIND_INET) {
+        SocketAddress *laddr = qio_channel_socket_get_local_address(
+            lioc, &error_abort);
+
+        connect_addr->inet->port = g_strdup(laddr->inet->port);
+
+        qapi_free_SocketAddress(laddr);
+    }
+
+    *src = QIO_CHANNEL(qio_channel_socket_new());
+    qio_channel_socket_connect_async(
+        QIO_CHANNEL_SOCKET(*src), connect_addr,
+        test_io_channel_complete, &data, NULL);
+
+    g_main_loop_run(data.loop);
+
+    g_assert(!data.err);
+
+    *dst = QIO_CHANNEL(qio_channel_socket_accept(lioc, &error_abort));
+    g_assert(*dst);
+
+    qio_channel_socket_set_nodelay(QIO_CHANNEL_SOCKET(*src), true);
+    test_io_channel_set_socket_bufs(*src, *dst);
+
+    object_unref(OBJECT(lioc));
+}
+
+
+static void test_io_channel(bool async,
+                            SocketAddress *listen_addr,
+                            SocketAddress *connect_addr)
+{
+    QIOChannel *src, *dst;
+    if (async) {
+        test_io_channel_setup_async(listen_addr, connect_addr, &src, &dst);
+        test_io_channel_comms(true, src, dst);
+        object_unref(OBJECT(src));
+        object_unref(OBJECT(dst));
+
+        test_io_channel_setup_async(listen_addr, connect_addr, &src, &dst);
+        test_io_channel_comms(false, src, dst);
+        object_unref(OBJECT(src));
+        object_unref(OBJECT(dst));
+    } else {
+        test_io_channel_setup_sync(listen_addr, connect_addr, &src, &dst);
+        test_io_channel_comms(true, src, dst);
+        object_unref(OBJECT(src));
+        object_unref(OBJECT(dst));
+
+        test_io_channel_setup_sync(listen_addr, connect_addr, &src, &dst);
+        test_io_channel_comms(false, src, dst);
+        object_unref(OBJECT(src));
+        object_unref(OBJECT(dst));
+    }
+}
+
+
+static void test_io_channel_ipv4(bool async)
+{
+    SocketAddress *listen_addr = g_new0(SocketAddress, 1);
+    SocketAddress *connect_addr = g_new0(SocketAddress, 1);
+
+    listen_addr->kind = SOCKET_ADDRESS_KIND_INET;
+    listen_addr->inet = g_new0(InetSocketAddress, 1);
+    listen_addr->inet->host = g_strdup("0.0.0.0");
+    listen_addr->inet->port = NULL; /* Auto-select */
+
+    connect_addr->kind = SOCKET_ADDRESS_KIND_INET;
+    connect_addr->inet = g_new0(InetSocketAddress, 1);
+    connect_addr->inet->host = g_strdup("127.0.0.1");
+    connect_addr->inet->port = NULL; /* Filled in later */
+
+    test_io_channel(async, listen_addr, connect_addr);
+}
+
+
+static void test_io_channel_ipv4_sync(void)
+{
+    return test_io_channel_ipv4(false);
+}
+
+
+static void test_io_channel_ipv4_async(void)
+{
+    return test_io_channel_ipv4(true);
+}
+
+
+static void test_io_channel_ipv6(bool async)
+{
+    SocketAddress *listen_addr = g_new0(SocketAddress, 1);
+    SocketAddress *connect_addr = g_new0(SocketAddress, 1);
+
+    listen_addr->kind = SOCKET_ADDRESS_KIND_INET;
+    listen_addr->inet = g_new0(InetSocketAddress, 1);
+    listen_addr->inet->host = g_strdup("::");
+    listen_addr->inet->port = NULL; /* Auto-select */
+
+    connect_addr->kind = SOCKET_ADDRESS_KIND_INET;
+    connect_addr->inet = g_new0(InetSocketAddress, 1);
+    connect_addr->inet->host = g_strdup("::1");
+    connect_addr->inet->port = NULL; /* Filled in later */
+
+    test_io_channel(async, listen_addr, connect_addr);
+}
+
+
+static void test_io_channel_ipv6_sync(void)
+{
+    return test_io_channel_ipv6(false);
+}
+
+
+static void test_io_channel_ipv6_async(void)
+{
+    return test_io_channel_ipv6(true);
+}
+
+
+#ifndef _WIN32
+static void test_io_channel_unix(bool async)
+{
+    SocketAddress *listen_addr = g_new0(SocketAddress, 1);
+    SocketAddress *connect_addr = g_new0(SocketAddress, 1);
+
+    listen_addr->kind = SOCKET_ADDRESS_KIND_UNIX;
+    listen_addr->q_unix = g_new0(UnixSocketAddress, 1);
+    listen_addr->q_unix->path = g_strdup("test-io-channel-socket.sock");
+
+    connect_addr->kind = SOCKET_ADDRESS_KIND_UNIX;
+    connect_addr->q_unix = g_new0(UnixSocketAddress, 1);
+    connect_addr->q_unix->path = g_strdup("test-io-channel-socket.sock");
+
+    test_io_channel(async, listen_addr, connect_addr);
+}
+
+
+static void test_io_channel_unix_sync(void)
+{
+    return test_io_channel_unix(false);
+}
+
+
+static void test_io_channel_unix_async(void)
+{
+    return test_io_channel_unix(true);
+}
+#endif /* _WIN32 */
+
+
+int main(int argc, char **argv)
+{
+    bool has_ipv4, has_ipv6;
+
+    module_call_init(MODULE_INIT_QOM);
+
+    g_test_init(&argc, &argv, NULL);
+
+    if (check_protocol_support(&has_ipv4, &has_ipv6) < 0) {
+        return 1;
+    }
+
+    if (has_ipv4) {
+        g_test_add_func("/io/channel/socket/ipv4-sync", test_io_channel_ipv4_sync);
+        g_test_add_func("/io/channel/socket/ipv4-async", test_io_channel_ipv4_async);
+    }
+    if (has_ipv6) {
+        g_test_add_func("/io/channel/socket/ipv6-sync", test_io_channel_ipv6_sync);
+        g_test_add_func("/io/channel/socket/ipv6-async", test_io_channel_ipv6_async);
+    }
+
+#ifndef _WIN32
+    g_test_add_func("/io/channel/socket/unix-sync", test_io_channel_unix_sync);
+    g_test_add_func("/io/channel/socket/unix-async", test_io_channel_unix_async);
+#endif /* _WIN32 */
+
+    return g_test_run();
+}
-- 
2.4.3