qemu/io/channel-file.c

226 lines
6.0 KiB
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 "qemu/osdep.h"
#include "io/channel-file.h"
#include "io/channel-watch.h"
#include "qapi/error.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) {
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) {
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);