io: add QIOChannelFile class

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>
This commit is contained in:
Daniel P. Berrange 2015-02-27 18:25:25 +00:00
parent 559607ea17
commit d6e48869a4
7 changed files with 428 additions and 0 deletions

93
include/io/channel-file.h Normal file
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@ -0,0 +1,93 @@
/*
* 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__ */

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@ -1,4 +1,5 @@
io-obj-y = channel.o
io-obj-y += channel-file.o
io-obj-y += channel-socket.o
io-obj-y += channel-watch.o
io-obj-y += task.o

225
io/channel-file.c Normal file
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@ -0,0 +1,225 @@
/*
* 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);

2
tests/.gitignore vendored
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@ -24,6 +24,8 @@ test-cutils
test-hbitmap
test-int128
test-iov
test-io-channel-file
test-io-channel-file.txt
test-io-channel-socket
test-io-task
test-mul64

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@ -86,6 +86,7 @@ check-unit-$(CONFIG_LINUX) += tests/test-qga$(EXESUF)
check-unit-y += tests/test-timed-average$(EXESUF)
check-unit-y += tests/test-io-task$(EXESUF)
check-unit-y += tests/test-io-channel-socket$(EXESUF)
check-unit-y += tests/test-io-channel-file$(EXESUF)
check-block-$(CONFIG_POSIX) += tests/qemu-iotests-quick.sh
@ -475,6 +476,8 @@ tests/test-crypto-tlssession$(EXESUF): tests/test-crypto-tlssession.o \
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 $(test-io-obj-y)
tests/test-io-channel-file$(EXESUF): tests/test-io-channel-file.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

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@ -0,0 +1,100 @@
/*
* QEMU I/O channel file 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-file.h"
#include "io-channel-helpers.h"
static void test_io_channel_file(void)
{
QIOChannel *src, *dst;
QIOChannelTest *test;
#define TEST_FILE "tests/test-io-channel-file.txt"
unlink(TEST_FILE);
src = QIO_CHANNEL(qio_channel_file_new_path(
TEST_FILE,
O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0600,
&error_abort));
dst = QIO_CHANNEL(qio_channel_file_new_path(
TEST_FILE,
O_RDONLY | O_BINARY, 0,
&error_abort));
test = qio_channel_test_new();
qio_channel_test_run_writer(test, src);
qio_channel_test_run_reader(test, dst);
qio_channel_test_validate(test);
unlink(TEST_FILE);
object_unref(OBJECT(src));
object_unref(OBJECT(dst));
}
#ifndef _WIN32
static void test_io_channel_pipe(bool async)
{
QIOChannel *src, *dst;
QIOChannelTest *test;
int fd[2];
if (pipe(fd) < 0) {
perror("pipe");
abort();
}
src = QIO_CHANNEL(qio_channel_file_new_fd(fd[1]));
dst = QIO_CHANNEL(qio_channel_file_new_fd(fd[0]));
test = qio_channel_test_new();
qio_channel_test_run_threads(test, async, src, dst);
qio_channel_test_validate(test);
object_unref(OBJECT(src));
object_unref(OBJECT(dst));
}
static void test_io_channel_pipe_async(void)
{
test_io_channel_pipe(true);
}
static void test_io_channel_pipe_sync(void)
{
test_io_channel_pipe(false);
}
#endif /* ! _WIN32 */
int main(int argc, char **argv)
{
module_call_init(MODULE_INIT_QOM);
g_test_init(&argc, &argv, NULL);
g_test_add_func("/io/channel/file", test_io_channel_file);
#ifndef _WIN32
g_test_add_func("/io/channel/pipe/sync", test_io_channel_pipe_sync);
g_test_add_func("/io/channel/pipe/async", test_io_channel_pipe_async);
#endif
return g_test_run();
}

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@ -1836,3 +1836,7 @@ qio_channel_socket_dgram_complete(void *ioc, int fd) "Socket dgram complete ioc=
qio_channel_socket_accept(void *ioc) "Socket accept start ioc=%p"
qio_channel_socket_accept_fail(void *ioc) "Socket accept fail ioc=%p"
qio_channel_socket_accept_complete(void *ioc, void *cioc, int fd) "Socket accept complete ioc=%p cioc=%p fd=%d"
# io/channel-file.c
qio_channel_file_new_fd(void *ioc, int fd) "File new fd ioc=%p fd=%d"
qio_channel_file_new_path(void *ioc, const char *path, int flags, int mode, int fd) "File new fd ioc=%p path=%s flags=%d mode=%d fd=%d"