qemu/qemu-file.c
Eduardo Habkost c54d1c0670 qemu-file: Move stdio implementation to qemu-file-stdio.c
Separate the QEMUFile interface from the stdio-specific implementation,
to reduce dependencies from code using QEMUFile.

The code that is being moved is similar to the one that was on savevm.c before
it was moved in commit 093c455a8c, except for
some changes done by Markus, Juan, and myself. So, I am using the copyright and
license header from savevm.c, but CCing Juan and Markus so they can review the
copyright/license header.

Cc: Markus Armbruster <armbru@redhat.com>
Cc: Juan Quintela <quintela@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2014-10-14 10:29:28 +02:00

996 lines
23 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 "qemu/iov.h"
#include "qemu/sockets.h"
#include "block/coroutine.h"
#include "migration/migration.h"
#include "migration/qemu-file.h"
#include "trace.h"
#define IO_BUF_SIZE 32768
#define MAX_IOV_SIZE MIN(IOV_MAX, 64)
struct QEMUFile {
const QEMUFileOps *ops;
void *opaque;
int64_t bytes_xfer;
int64_t xfer_limit;
int64_t pos; /* start of buffer when writing, end of buffer
when reading */
int buf_index;
int buf_size; /* 0 when writing */
uint8_t buf[IO_BUF_SIZE];
struct iovec iov[MAX_IOV_SIZE];
unsigned int iovcnt;
int last_error;
};
bool qemu_file_mode_is_not_valid(const char *mode)
{
if (mode == NULL ||
(mode[0] != 'r' && mode[0] != 'w') ||
mode[1] != 'b' || mode[2] != 0) {
fprintf(stderr, "qemu_fopen: Argument validity check failed\n");
return true;
}
return false;
}
QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops)
{
QEMUFile *f;
f = g_malloc0(sizeof(QEMUFile));
f->opaque = opaque;
f->ops = ops;
return f;
}
/*
* Get last error for stream f
*
* Return negative error value if there has been an error on previous
* operations, return 0 if no error happened.
*
*/
int qemu_file_get_error(QEMUFile *f)
{
return f->last_error;
}
void qemu_file_set_error(QEMUFile *f, int ret)
{
if (f->last_error == 0) {
f->last_error = ret;
}
}
bool qemu_file_is_writable(QEMUFile *f)
{
return f->ops->writev_buffer || f->ops->put_buffer;
}
/**
* Flushes QEMUFile buffer
*
* If there is writev_buffer QEMUFileOps it uses it otherwise uses
* put_buffer ops.
*/
void qemu_fflush(QEMUFile *f)
{
ssize_t ret = 0;
if (!qemu_file_is_writable(f)) {
return;
}
if (f->ops->writev_buffer) {
if (f->iovcnt > 0) {
ret = f->ops->writev_buffer(f->opaque, f->iov, f->iovcnt, f->pos);
}
} else {
if (f->buf_index > 0) {
ret = f->ops->put_buffer(f->opaque, f->buf, f->pos, f->buf_index);
}
}
if (ret >= 0) {
f->pos += ret;
}
f->buf_index = 0;
f->iovcnt = 0;
if (ret < 0) {
qemu_file_set_error(f, ret);
}
}
void ram_control_before_iterate(QEMUFile *f, uint64_t flags)
{
int ret = 0;
if (f->ops->before_ram_iterate) {
ret = f->ops->before_ram_iterate(f, f->opaque, flags);
if (ret < 0) {
qemu_file_set_error(f, ret);
}
}
}
void ram_control_after_iterate(QEMUFile *f, uint64_t flags)
{
int ret = 0;
if (f->ops->after_ram_iterate) {
ret = f->ops->after_ram_iterate(f, f->opaque, flags);
if (ret < 0) {
qemu_file_set_error(f, ret);
}
}
}
void ram_control_load_hook(QEMUFile *f, uint64_t flags)
{
int ret = -EINVAL;
if (f->ops->hook_ram_load) {
ret = f->ops->hook_ram_load(f, f->opaque, flags);
if (ret < 0) {
qemu_file_set_error(f, ret);
}
} else {
qemu_file_set_error(f, ret);
}
}
size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
ram_addr_t offset, size_t size, int *bytes_sent)
{
if (f->ops->save_page) {
int ret = f->ops->save_page(f, f->opaque, block_offset,
offset, size, bytes_sent);
if (ret != RAM_SAVE_CONTROL_DELAYED) {
if (bytes_sent && *bytes_sent > 0) {
qemu_update_position(f, *bytes_sent);
} else if (ret < 0) {
qemu_file_set_error(f, ret);
}
}
return ret;
}
return RAM_SAVE_CONTROL_NOT_SUPP;
}
/*
* Attempt to fill the buffer from the underlying file
* Returns the number of bytes read, or negative value for an error.
*
* Note that it can return a partially full buffer even in a not error/not EOF
* case if the underlying file descriptor gives a short read, and that can
* happen even on a blocking fd.
*/
static ssize_t qemu_fill_buffer(QEMUFile *f)
{
int len;
int pending;
assert(!qemu_file_is_writable(f));
pending = f->buf_size - f->buf_index;
if (pending > 0) {
memmove(f->buf, f->buf + f->buf_index, pending);
}
f->buf_index = 0;
f->buf_size = pending;
len = f->ops->get_buffer(f->opaque, f->buf + pending, f->pos,
IO_BUF_SIZE - pending);
if (len > 0) {
f->buf_size += len;
f->pos += len;
} else if (len == 0) {
qemu_file_set_error(f, -EIO);
} else if (len != -EAGAIN) {
qemu_file_set_error(f, len);
}
return len;
}
int qemu_get_fd(QEMUFile *f)
{
if (f->ops->get_fd) {
return f->ops->get_fd(f->opaque);
}
return -1;
}
void qemu_update_position(QEMUFile *f, size_t size)
{
f->pos += size;
}
/** Closes the file
*
* Returns negative error value if any error happened on previous operations or
* while closing the file. Returns 0 or positive number on success.
*
* The meaning of return value on success depends on the specific backend
* being used.
*/
int qemu_fclose(QEMUFile *f)
{
int ret;
qemu_fflush(f);
ret = qemu_file_get_error(f);
if (f->ops->close) {
int ret2 = f->ops->close(f->opaque);
if (ret >= 0) {
ret = ret2;
}
}
/* If any error was spotted before closing, we should report it
* instead of the close() return value.
*/
if (f->last_error) {
ret = f->last_error;
}
g_free(f);
trace_qemu_file_fclose();
return ret;
}
static void add_to_iovec(QEMUFile *f, const uint8_t *buf, int size)
{
/* check for adjacent buffer and coalesce them */
if (f->iovcnt > 0 && buf == f->iov[f->iovcnt - 1].iov_base +
f->iov[f->iovcnt - 1].iov_len) {
f->iov[f->iovcnt - 1].iov_len += size;
} else {
f->iov[f->iovcnt].iov_base = (uint8_t *)buf;
f->iov[f->iovcnt++].iov_len = size;
}
if (f->iovcnt >= MAX_IOV_SIZE) {
qemu_fflush(f);
}
}
void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, int size)
{
if (!f->ops->writev_buffer) {
qemu_put_buffer(f, buf, size);
return;
}
if (f->last_error) {
return;
}
f->bytes_xfer += size;
add_to_iovec(f, buf, size);
}
void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size)
{
int l;
if (f->last_error) {
return;
}
while (size > 0) {
l = IO_BUF_SIZE - f->buf_index;
if (l > size) {
l = size;
}
memcpy(f->buf + f->buf_index, buf, l);
f->bytes_xfer += l;
if (f->ops->writev_buffer) {
add_to_iovec(f, f->buf + f->buf_index, l);
}
f->buf_index += l;
if (f->buf_index == IO_BUF_SIZE) {
qemu_fflush(f);
}
if (qemu_file_get_error(f)) {
break;
}
buf += l;
size -= l;
}
}
void qemu_put_byte(QEMUFile *f, int v)
{
if (f->last_error) {
return;
}
f->buf[f->buf_index] = v;
f->bytes_xfer++;
if (f->ops->writev_buffer) {
add_to_iovec(f, f->buf + f->buf_index, 1);
}
f->buf_index++;
if (f->buf_index == IO_BUF_SIZE) {
qemu_fflush(f);
}
}
void qemu_file_skip(QEMUFile *f, int size)
{
if (f->buf_index + size <= f->buf_size) {
f->buf_index += size;
}
}
/*
* Read 'size' bytes from file (at 'offset') into buf without moving the
* pointer.
*
* It will return size bytes unless there was an error, in which case it will
* return as many as it managed to read (assuming blocking fd's which
* all current QEMUFile are)
*/
int qemu_peek_buffer(QEMUFile *f, uint8_t *buf, int size, size_t offset)
{
int pending;
int index;
assert(!qemu_file_is_writable(f));
assert(offset < IO_BUF_SIZE);
assert(size <= IO_BUF_SIZE - offset);
/* The 1st byte to read from */
index = f->buf_index + offset;
/* The number of available bytes starting at index */
pending = f->buf_size - index;
/*
* qemu_fill_buffer might return just a few bytes, even when there isn't
* an error, so loop collecting them until we get enough.
*/
while (pending < size) {
int received = qemu_fill_buffer(f);
if (received <= 0) {
break;
}
index = f->buf_index + offset;
pending = f->buf_size - index;
}
if (pending <= 0) {
return 0;
}
if (size > pending) {
size = pending;
}
memcpy(buf, f->buf + index, size);
return size;
}
/*
* Read 'size' bytes of data from the file into buf.
* 'size' can be larger than the internal buffer.
*
* It will return size bytes unless there was an error, in which case it will
* return as many as it managed to read (assuming blocking fd's which
* all current QEMUFile are)
*/
int qemu_get_buffer(QEMUFile *f, uint8_t *buf, int size)
{
int pending = size;
int done = 0;
while (pending > 0) {
int res;
res = qemu_peek_buffer(f, buf, MIN(pending, IO_BUF_SIZE), 0);
if (res == 0) {
return done;
}
qemu_file_skip(f, res);
buf += res;
pending -= res;
done += res;
}
return done;
}
/*
* Peeks a single byte from the buffer; this isn't guaranteed to work if
* offset leaves a gap after the previous read/peeked data.
*/
int qemu_peek_byte(QEMUFile *f, int offset)
{
int index = f->buf_index + offset;
assert(!qemu_file_is_writable(f));
assert(offset < IO_BUF_SIZE);
if (index >= f->buf_size) {
qemu_fill_buffer(f);
index = f->buf_index + offset;
if (index >= f->buf_size) {
return 0;
}
}
return f->buf[index];
}
int qemu_get_byte(QEMUFile *f)
{
int result;
result = qemu_peek_byte(f, 0);
qemu_file_skip(f, 1);
return result;
}
int64_t qemu_ftell(QEMUFile *f)
{
qemu_fflush(f);
return f->pos;
}
int qemu_file_rate_limit(QEMUFile *f)
{
if (qemu_file_get_error(f)) {
return 1;
}
if (f->xfer_limit > 0 && f->bytes_xfer > f->xfer_limit) {
return 1;
}
return 0;
}
int64_t qemu_file_get_rate_limit(QEMUFile *f)
{
return f->xfer_limit;
}
void qemu_file_set_rate_limit(QEMUFile *f, int64_t limit)
{
f->xfer_limit = limit;
}
void qemu_file_reset_rate_limit(QEMUFile *f)
{
f->bytes_xfer = 0;
}
void qemu_put_be16(QEMUFile *f, unsigned int v)
{
qemu_put_byte(f, v >> 8);
qemu_put_byte(f, v);
}
void qemu_put_be32(QEMUFile *f, unsigned int v)
{
qemu_put_byte(f, v >> 24);
qemu_put_byte(f, v >> 16);
qemu_put_byte(f, v >> 8);
qemu_put_byte(f, v);
}
void qemu_put_be64(QEMUFile *f, uint64_t v)
{
qemu_put_be32(f, v >> 32);
qemu_put_be32(f, v);
}
unsigned int qemu_get_be16(QEMUFile *f)
{
unsigned int v;
v = qemu_get_byte(f) << 8;
v |= qemu_get_byte(f);
return v;
}
unsigned int qemu_get_be32(QEMUFile *f)
{
unsigned int v;
v = qemu_get_byte(f) << 24;
v |= qemu_get_byte(f) << 16;
v |= qemu_get_byte(f) << 8;
v |= qemu_get_byte(f);
return v;
}
uint64_t qemu_get_be64(QEMUFile *f)
{
uint64_t v;
v = (uint64_t)qemu_get_be32(f) << 32;
v |= qemu_get_be32(f);
return v;
}
#define QSB_CHUNK_SIZE (1 << 10)
#define QSB_MAX_CHUNK_SIZE (16 * QSB_CHUNK_SIZE)
/**
* Create a QEMUSizedBuffer
* This type of buffer uses scatter-gather lists internally and
* can grow to any size. Any data array in the scatter-gather list
* can hold different amount of bytes.
*
* @buffer: Optional buffer to copy into the QSB
* @len: size of initial buffer; if @buffer is given, buffer must
* hold at least len bytes
*
* Returns a pointer to a QEMUSizedBuffer or NULL on allocation failure
*/
QEMUSizedBuffer *qsb_create(const uint8_t *buffer, size_t len)
{
QEMUSizedBuffer *qsb;
size_t alloc_len, num_chunks, i, to_copy;
size_t chunk_size = (len > QSB_MAX_CHUNK_SIZE)
? QSB_MAX_CHUNK_SIZE
: QSB_CHUNK_SIZE;
num_chunks = DIV_ROUND_UP(len ? len : QSB_CHUNK_SIZE, chunk_size);
alloc_len = num_chunks * chunk_size;
qsb = g_try_new0(QEMUSizedBuffer, 1);
if (!qsb) {
return NULL;
}
qsb->iov = g_try_new0(struct iovec, num_chunks);
if (!qsb->iov) {
g_free(qsb);
return NULL;
}
qsb->n_iov = num_chunks;
for (i = 0; i < num_chunks; i++) {
qsb->iov[i].iov_base = g_try_malloc0(chunk_size);
if (!qsb->iov[i].iov_base) {
/* qsb_free is safe since g_free can cope with NULL */
qsb_free(qsb);
return NULL;
}
qsb->iov[i].iov_len = chunk_size;
if (buffer) {
to_copy = (len - qsb->used) > chunk_size
? chunk_size : (len - qsb->used);
memcpy(qsb->iov[i].iov_base, &buffer[qsb->used], to_copy);
qsb->used += to_copy;
}
}
qsb->size = alloc_len;
return qsb;
}
/**
* Free the QEMUSizedBuffer
*
* @qsb: The QEMUSizedBuffer to free
*/
void qsb_free(QEMUSizedBuffer *qsb)
{
size_t i;
if (!qsb) {
return;
}
for (i = 0; i < qsb->n_iov; i++) {
g_free(qsb->iov[i].iov_base);
}
g_free(qsb->iov);
g_free(qsb);
}
/**
* Get the number of used bytes in the QEMUSizedBuffer
*
* @qsb: A QEMUSizedBuffer
*
* Returns the number of bytes currently used in this buffer
*/
size_t qsb_get_length(const QEMUSizedBuffer *qsb)
{
return qsb->used;
}
/**
* Set the length of the buffer; the primary usage of this
* function is to truncate the number of used bytes in the buffer.
* The size will not be extended beyond the current number of
* allocated bytes in the QEMUSizedBuffer.
*
* @qsb: A QEMUSizedBuffer
* @new_len: The new length of bytes in the buffer
*
* Returns the number of bytes the buffer was truncated or extended
* to.
*/
size_t qsb_set_length(QEMUSizedBuffer *qsb, size_t new_len)
{
if (new_len <= qsb->size) {
qsb->used = new_len;
} else {
qsb->used = qsb->size;
}
return qsb->used;
}
/**
* Get the iovec that holds the data for a given position @pos.
*
* @qsb: A QEMUSizedBuffer
* @pos: The index of a byte in the buffer
* @d_off: Pointer to an offset that this function will indicate
* at what position within the returned iovec the byte
* is to be found
*
* Returns the index of the iovec that holds the byte at the given
* index @pos in the byte stream; a negative number if the iovec
* for the given position @pos does not exist.
*/
static ssize_t qsb_get_iovec(const QEMUSizedBuffer *qsb,
off_t pos, off_t *d_off)
{
ssize_t i;
off_t curr = 0;
if (pos > qsb->used) {
return -1;
}
for (i = 0; i < qsb->n_iov; i++) {
if (curr + qsb->iov[i].iov_len > pos) {
*d_off = pos - curr;
return i;
}
curr += qsb->iov[i].iov_len;
}
return -1;
}
/*
* Convert the QEMUSizedBuffer into a flat buffer.
*
* Note: If at all possible, try to avoid this function since it
* may unnecessarily copy memory around.
*
* @qsb: pointer to QEMUSizedBuffer
* @start: offset to start at
* @count: number of bytes to copy
* @buf: a pointer to a buffer to write into (at least @count bytes)
*
* Returns the number of bytes copied into the output buffer
*/
ssize_t qsb_get_buffer(const QEMUSizedBuffer *qsb, off_t start,
size_t count, uint8_t *buffer)
{
const struct iovec *iov;
size_t to_copy, all_copy;
ssize_t index;
off_t s_off;
off_t d_off = 0;
char *s;
if (start > qsb->used) {
return 0;
}
all_copy = qsb->used - start;
if (all_copy > count) {
all_copy = count;
} else {
count = all_copy;
}
index = qsb_get_iovec(qsb, start, &s_off);
if (index < 0) {
return 0;
}
while (all_copy > 0) {
iov = &qsb->iov[index];
s = iov->iov_base;
to_copy = iov->iov_len - s_off;
if (to_copy > all_copy) {
to_copy = all_copy;
}
memcpy(&buffer[d_off], &s[s_off], to_copy);
d_off += to_copy;
all_copy -= to_copy;
s_off = 0;
index++;
}
return count;
}
/**
* Grow the QEMUSizedBuffer to the given size and allocate
* memory for it.
*
* @qsb: A QEMUSizedBuffer
* @new_size: The new size of the buffer
*
* Return:
* a negative error code in case of memory allocation failure
* or
* the new size of the buffer. The returned size may be greater or equal
* to @new_size.
*/
static ssize_t qsb_grow(QEMUSizedBuffer *qsb, size_t new_size)
{
size_t needed_chunks, i;
if (qsb->size < new_size) {
struct iovec *new_iov;
size_t size_diff = new_size - qsb->size;
size_t chunk_size = (size_diff > QSB_MAX_CHUNK_SIZE)
? QSB_MAX_CHUNK_SIZE : QSB_CHUNK_SIZE;
needed_chunks = DIV_ROUND_UP(size_diff, chunk_size);
new_iov = g_try_new(struct iovec, qsb->n_iov + needed_chunks);
if (new_iov == NULL) {
return -ENOMEM;
}
/* Allocate new chunks as needed into new_iov */
for (i = qsb->n_iov; i < qsb->n_iov + needed_chunks; i++) {
new_iov[i].iov_base = g_try_malloc0(chunk_size);
new_iov[i].iov_len = chunk_size;
if (!new_iov[i].iov_base) {
size_t j;
/* Free previously allocated new chunks */
for (j = qsb->n_iov; j < i; j++) {
g_free(new_iov[j].iov_base);
}
g_free(new_iov);
return -ENOMEM;
}
}
/*
* Now we can't get any allocation errors, copy over to new iov
* and switch.
*/
for (i = 0; i < qsb->n_iov; i++) {
new_iov[i] = qsb->iov[i];
}
qsb->n_iov += needed_chunks;
g_free(qsb->iov);
qsb->iov = new_iov;
qsb->size += (needed_chunks * chunk_size);
}
return qsb->size;
}
/**
* Write into the QEMUSizedBuffer at a given position and a given
* number of bytes. This function will automatically grow the
* QEMUSizedBuffer.
*
* @qsb: A QEMUSizedBuffer
* @source: A byte array to copy data from
* @pos: The position within the @qsb to write data to
* @size: The number of bytes to copy into the @qsb
*
* Returns @size or a negative error code in case of memory allocation failure,
* or with an invalid 'pos'
*/
ssize_t qsb_write_at(QEMUSizedBuffer *qsb, const uint8_t *source,
off_t pos, size_t count)
{
ssize_t rc = qsb_grow(qsb, pos + count);
size_t to_copy;
size_t all_copy = count;
const struct iovec *iov;
ssize_t index;
char *dest;
off_t d_off, s_off = 0;
if (rc < 0) {
return rc;
}
if (pos + count > qsb->used) {
qsb->used = pos + count;
}
index = qsb_get_iovec(qsb, pos, &d_off);
if (index < 0) {
return -EINVAL;
}
while (all_copy > 0) {
iov = &qsb->iov[index];
dest = iov->iov_base;
to_copy = iov->iov_len - d_off;
if (to_copy > all_copy) {
to_copy = all_copy;
}
memcpy(&dest[d_off], &source[s_off], to_copy);
s_off += to_copy;
all_copy -= to_copy;
d_off = 0;
index++;
}
return count;
}
/**
* Create a deep copy of the given QEMUSizedBuffer.
*
* @qsb: A QEMUSizedBuffer
*
* Returns a clone of @qsb or NULL on allocation failure
*/
QEMUSizedBuffer *qsb_clone(const QEMUSizedBuffer *qsb)
{
QEMUSizedBuffer *out = qsb_create(NULL, qsb_get_length(qsb));
size_t i;
ssize_t res;
off_t pos = 0;
if (!out) {
return NULL;
}
for (i = 0; i < qsb->n_iov; i++) {
res = qsb_write_at(out, qsb->iov[i].iov_base,
pos, qsb->iov[i].iov_len);
if (res < 0) {
qsb_free(out);
return NULL;
}
pos += res;
}
return out;
}
typedef struct QEMUBuffer {
QEMUSizedBuffer *qsb;
QEMUFile *file;
} QEMUBuffer;
static int buf_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
{
QEMUBuffer *s = opaque;
ssize_t len = qsb_get_length(s->qsb) - pos;
if (len <= 0) {
return 0;
}
if (len > size) {
len = size;
}
return qsb_get_buffer(s->qsb, pos, len, buf);
}
static int buf_put_buffer(void *opaque, const uint8_t *buf,
int64_t pos, int size)
{
QEMUBuffer *s = opaque;
return qsb_write_at(s->qsb, buf, pos, size);
}
static int buf_close(void *opaque)
{
QEMUBuffer *s = opaque;
qsb_free(s->qsb);
g_free(s);
return 0;
}
const QEMUSizedBuffer *qemu_buf_get(QEMUFile *f)
{
QEMUBuffer *p;
qemu_fflush(f);
p = f->opaque;
return p->qsb;
}
static const QEMUFileOps buf_read_ops = {
.get_buffer = buf_get_buffer,
.close = buf_close,
};
static const QEMUFileOps buf_write_ops = {
.put_buffer = buf_put_buffer,
.close = buf_close,
};
QEMUFile *qemu_bufopen(const char *mode, QEMUSizedBuffer *input)
{
QEMUBuffer *s;
if (mode == NULL || (mode[0] != 'r' && mode[0] != 'w') ||
mode[1] != '\0') {
error_report("qemu_bufopen: Argument validity check failed");
return NULL;
}
s = g_malloc0(sizeof(QEMUBuffer));
if (mode[0] == 'r') {
s->qsb = input;
}
if (s->qsb == NULL) {
s->qsb = qsb_create(NULL, 0);
}
if (!s->qsb) {
g_free(s);
error_report("qemu_bufopen: qsb_create failed");
return NULL;
}
if (mode[0] == 'r') {
s->file = qemu_fopen_ops(s, &buf_read_ops);
} else {
s->file = qemu_fopen_ops(s, &buf_write_ops);
}
return s->file;
}