qemu/qemu-file-stdio.c

195 lines
4.9 KiB
C

/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu-common.h"
#include "block/coroutine.h"
#include "migration/qemu-file.h"
typedef struct QEMUFileStdio {
FILE *stdio_file;
QEMUFile *file;
} QEMUFileStdio;
static int stdio_get_fd(void *opaque)
{
QEMUFileStdio *s = opaque;
return fileno(s->stdio_file);
}
static int stdio_put_buffer(void *opaque, const uint8_t *buf, int64_t pos,
int size)
{
QEMUFileStdio *s = opaque;
int res;
res = fwrite(buf, 1, size, s->stdio_file);
if (res != size) {
return -errno;
}
return res;
}
static int stdio_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
{
QEMUFileStdio *s = opaque;
FILE *fp = s->stdio_file;
int bytes;
for (;;) {
clearerr(fp);
bytes = fread(buf, 1, size, fp);
if (bytes != 0 || !ferror(fp)) {
break;
}
if (errno == EAGAIN) {
yield_until_fd_readable(fileno(fp));
} else if (errno != EINTR) {
break;
}
}
return bytes;
}
static int stdio_pclose(void *opaque)
{
QEMUFileStdio *s = opaque;
int ret;
ret = pclose(s->stdio_file);
if (ret == -1) {
ret = -errno;
} else if (!WIFEXITED(ret) || WEXITSTATUS(ret) != 0) {
/* close succeeded, but non-zero exit code: */
ret = -EIO; /* fake errno value */
}
g_free(s);
return ret;
}
static int stdio_fclose(void *opaque)
{
QEMUFileStdio *s = opaque;
int ret = 0;
if (qemu_file_is_writable(s->file)) {
int fd = fileno(s->stdio_file);
struct stat st;
ret = fstat(fd, &st);
if (ret == 0 && S_ISREG(st.st_mode)) {
/*
* If the file handle is a regular file make sure the
* data is flushed to disk before signaling success.
*/
ret = fsync(fd);
if (ret != 0) {
ret = -errno;
return ret;
}
}
}
if (fclose(s->stdio_file) == EOF) {
ret = -errno;
}
g_free(s);
return ret;
}
static const QEMUFileOps stdio_pipe_read_ops = {
.get_fd = stdio_get_fd,
.get_buffer = stdio_get_buffer,
.close = stdio_pclose
};
static const QEMUFileOps stdio_pipe_write_ops = {
.get_fd = stdio_get_fd,
.put_buffer = stdio_put_buffer,
.close = stdio_pclose
};
QEMUFile *qemu_popen_cmd(const char *command, const char *mode)
{
FILE *stdio_file;
QEMUFileStdio *s;
if (mode == NULL || (mode[0] != 'r' && mode[0] != 'w') || mode[1] != 0) {
fprintf(stderr, "qemu_popen: Argument validity check failed\n");
return NULL;
}
stdio_file = popen(command, mode);
if (stdio_file == NULL) {
return NULL;
}
s = g_malloc0(sizeof(QEMUFileStdio));
s->stdio_file = stdio_file;
if (mode[0] == 'r') {
s->file = qemu_fopen_ops(s, &stdio_pipe_read_ops);
} else {
s->file = qemu_fopen_ops(s, &stdio_pipe_write_ops);
}
return s->file;
}
static const QEMUFileOps stdio_file_read_ops = {
.get_fd = stdio_get_fd,
.get_buffer = stdio_get_buffer,
.close = stdio_fclose
};
static const QEMUFileOps stdio_file_write_ops = {
.get_fd = stdio_get_fd,
.put_buffer = stdio_put_buffer,
.close = stdio_fclose
};
QEMUFile *qemu_fopen(const char *filename, const char *mode)
{
QEMUFileStdio *s;
if (qemu_file_mode_is_not_valid(mode)) {
return NULL;
}
s = g_malloc0(sizeof(QEMUFileStdio));
s->stdio_file = fopen(filename, mode);
if (!s->stdio_file) {
goto fail;
}
if (mode[0] == 'w') {
s->file = qemu_fopen_ops(s, &stdio_file_write_ops);
} else {
s->file = qemu_fopen_ops(s, &stdio_file_read_ops);
}
return s->file;
fail:
g_free(s);
return NULL;
}