new file mode 100644
@@ -0,0 +1,67 @@
+/*
+ * 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 "qemu:io-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.
+ *
+ * Returns: the new channel object
+ */
+QIOChannelFile *
+qio_channel_file_new_fd(int fd);
+
+#endif /* QIO_CHANNEL_FILE_H__ */
@@ -1,3 +1,4 @@
util-obj-y += channel.o
util-obj-y += channel-unix.o
util-obj-y += channel-socket.o
+util-obj-y += channel-file.o
new file mode 100644
@@ -0,0 +1,198 @@
+/*
+ * 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 <glib/gi18n.h>
+
+#include "io/channel-file.h"
+#include "io/channel-unix.h"
+#include "qemu/sockets.h"
+
+QIOChannelFile *
+qio_channel_file_new_fd(int fd)
+{
+ QIOChannelFile *ioc;
+
+ ioc = QIO_CHANNEL_FILE(object_new(TYPE_QIO_CHANNEL_FILE));
+
+ ioc->fd = 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,
+ int flags,
+ Error **errp)
+{
+ QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+ ssize_t ret;
+
+ if (flags) {
+ error_setg_errno(errp, EINVAL,
+ _("Flags %x are not supported"),
+ flags);
+ return -1;
+ }
+ if (fds || nfds) {
+ error_setg_errno(errp, EINVAL, "%s",
+ _("Channel does not support file descriptor passing"));
+ return -1;
+ }
+
+ retry:
+ ret = readv(fioc->fd, iov, niov);
+ if (ret < 0) {
+ if (errno == EAGAIN) {
+ return -2;
+ }
+ if (errno == EINTR) {
+ goto retry;
+ }
+
+ error_setg_errno(errp, errno, "%s",
+ _("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,
+ int flags G_GNUC_UNUSED,
+ Error **errp)
+{
+ QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+ ssize_t ret;
+
+ if (flags) {
+ error_setg_errno(errp, EINVAL,
+ _("Flags %x are not supported"),
+ flags);
+ return -1;
+ }
+ if (fds || nfds) {
+ error_setg_errno(errp, EINVAL, "%s",
+ _("Channel does not support file descriptor passing"));
+ return -1;
+ }
+
+ retry:
+ ret = writev(fioc->fd, iov, niov);
+ if (ret <= 0) {
+ if (errno == EAGAIN) {
+ return -2;
+ }
+ if (errno == EINTR) {
+ goto retry;
+ }
+ error_setg_errno(errp, errno, "%s",
+ _("Unable to write to file"));
+ return -1;
+ }
+ return ret;
+}
+
+static void qio_channel_file_set_blocking(QIOChannel *ioc,
+ bool enabled)
+{
+ QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+
+ if (enabled) {
+ qemu_set_block(fioc->fd);
+ } else {
+ qemu_set_nonblock(fioc->fd);
+ }
+}
+
+
+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, "%s",
+ _("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_unix_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_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);
Add a QIOChannel subclass that is capable of operating on things that are files, such as plain files, pipes, character/block devices, but notably not sockets. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> --- include/io/channel-file.h | 67 ++++++++++++++++ io/Makefile.objs | 1 + io/channel-file.c | 198 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 266 insertions(+) create mode 100644 include/io/channel-file.h create mode 100644 io/channel-file.c