qemu/fsdev/virtio-9p-marshal.c

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/*
* Virtio 9p backend
*
* Copyright IBM, Corp. 2010
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include <glib.h>
#include <glib/gprintf.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/time.h>
#include <utime.h>
#include <sys/uio.h>
#include <string.h>
#include <stdint.h>
#include <errno.h>
#include "compiler.h"
#include "virtio-9p-marshal.h"
#include "bswap.h"
void v9fs_string_free(V9fsString *str)
{
g_free(str->data);
str->data = NULL;
str->size = 0;
}
void v9fs_string_null(V9fsString *str)
{
v9fs_string_free(str);
}
void GCC_FMT_ATTR(2, 3)
v9fs_string_sprintf(V9fsString *str, const char *fmt, ...)
{
va_list ap;
v9fs_string_free(str);
va_start(ap, fmt);
str->size = g_vasprintf(&str->data, fmt, ap);
va_end(ap);
}
void v9fs_string_copy(V9fsString *lhs, V9fsString *rhs)
{
v9fs_string_free(lhs);
v9fs_string_sprintf(lhs, "%s", rhs->data);
}
static ssize_t v9fs_packunpack(void *addr, struct iovec *sg, int sg_count,
size_t offset, size_t size, int pack)
{
int i = 0;
size_t copied = 0;
size_t req_size = size;
for (i = 0; size && i < sg_count; i++) {
size_t len;
if (offset >= sg[i].iov_len) {
/* skip this sg */
offset -= sg[i].iov_len;
continue;
} else {
len = MIN(sg[i].iov_len - offset, size);
if (pack) {
memcpy(sg[i].iov_base + offset, addr, len);
} else {
memcpy(addr, sg[i].iov_base + offset, len);
}
size -= len;
copied += len;
addr += len;
if (size) {
offset = 0;
continue;
}
}
}
if (copied < req_size) {
/*
* We copied less that requested size. error out
*/
return -ENOBUFS;
}
return copied;
}
static ssize_t v9fs_unpack(void *dst, struct iovec *out_sg, int out_num,
size_t offset, size_t size)
{
return v9fs_packunpack(dst, out_sg, out_num, offset, size, 0);
}
ssize_t v9fs_pack(struct iovec *in_sg, int in_num, size_t offset,
const void *src, size_t size)
{
return v9fs_packunpack((void *)src, in_sg, in_num, offset, size, 1);
}
ssize_t v9fs_unmarshal(struct iovec *out_sg, int out_num, size_t offset,
int bswap, const char *fmt, ...)
{
int i;
va_list ap;
ssize_t copied = 0;
size_t old_offset = offset;
va_start(ap, fmt);
for (i = 0; fmt[i]; i++) {
switch (fmt[i]) {
case 'b': {
uint8_t *valp = va_arg(ap, uint8_t *);
copied = v9fs_unpack(valp, out_sg, out_num, offset, sizeof(*valp));
break;
}
case 'w': {
uint16_t val, *valp;
valp = va_arg(ap, uint16_t *);
copied = v9fs_unpack(&val, out_sg, out_num, offset, sizeof(val));
if (bswap) {
*valp = le16_to_cpu(val);
} else {
*valp = val;
}
break;
}
case 'd': {
uint32_t val, *valp;
valp = va_arg(ap, uint32_t *);
copied = v9fs_unpack(&val, out_sg, out_num, offset, sizeof(val));
if (bswap) {
*valp = le32_to_cpu(val);
} else {
*valp = val;
}
break;
}
case 'q': {
uint64_t val, *valp;
valp = va_arg(ap, uint64_t *);
copied = v9fs_unpack(&val, out_sg, out_num, offset, sizeof(val));
if (bswap) {
*valp = le64_to_cpu(val);
} else {
*valp = val;
}
break;
}
case 's': {
V9fsString *str = va_arg(ap, V9fsString *);
copied = v9fs_unmarshal(out_sg, out_num, offset, bswap,
"w", &str->size);
if (copied > 0) {
offset += copied;
str->data = g_malloc(str->size + 1);
copied = v9fs_unpack(str->data, out_sg, out_num, offset,
str->size);
if (copied > 0) {
str->data[str->size] = 0;
} else {
v9fs_string_free(str);
}
}
break;
}
case 'Q': {
V9fsQID *qidp = va_arg(ap, V9fsQID *);
copied = v9fs_unmarshal(out_sg, out_num, offset, bswap, "bdq",
&qidp->type, &qidp->version, &qidp->path);
break;
}
case 'S': {
V9fsStat *statp = va_arg(ap, V9fsStat *);
copied = v9fs_unmarshal(out_sg, out_num, offset, bswap,
"wwdQdddqsssssddd",
&statp->size, &statp->type, &statp->dev,
&statp->qid, &statp->mode, &statp->atime,
&statp->mtime, &statp->length,
&statp->name, &statp->uid, &statp->gid,
&statp->muid, &statp->extension,
&statp->n_uid, &statp->n_gid,
&statp->n_muid);
break;
}
case 'I': {
V9fsIattr *iattr = va_arg(ap, V9fsIattr *);
copied = v9fs_unmarshal(out_sg, out_num, offset, bswap,
"ddddqqqqq",
&iattr->valid, &iattr->mode,
&iattr->uid, &iattr->gid, &iattr->size,
&iattr->atime_sec, &iattr->atime_nsec,
&iattr->mtime_sec, &iattr->mtime_nsec);
break;
}
default:
break;
}
if (copied < 0) {
va_end(ap);
return copied;
}
offset += copied;
}
va_end(ap);
return offset - old_offset;
}
ssize_t v9fs_marshal(struct iovec *in_sg, int in_num, size_t offset,
int bswap, const char *fmt, ...)
{
int i;
va_list ap;
ssize_t copied = 0;
size_t old_offset = offset;
va_start(ap, fmt);
for (i = 0; fmt[i]; i++) {
switch (fmt[i]) {
case 'b': {
uint8_t val = va_arg(ap, int);
copied = v9fs_pack(in_sg, in_num, offset, &val, sizeof(val));
break;
}
case 'w': {
uint16_t val;
if (bswap) {
cpu_to_le16w(&val, va_arg(ap, int));
} else {
val = va_arg(ap, int);
}
copied = v9fs_pack(in_sg, in_num, offset, &val, sizeof(val));
break;
}
case 'd': {
uint32_t val;
if (bswap) {
cpu_to_le32w(&val, va_arg(ap, uint32_t));
} else {
val = va_arg(ap, uint32_t);
}
copied = v9fs_pack(in_sg, in_num, offset, &val, sizeof(val));
break;
}
case 'q': {
uint64_t val;
if (bswap) {
cpu_to_le64w(&val, va_arg(ap, uint64_t));
} else {
val = va_arg(ap, uint64_t);
}
copied = v9fs_pack(in_sg, in_num, offset, &val, sizeof(val));
break;
}
case 's': {
V9fsString *str = va_arg(ap, V9fsString *);
copied = v9fs_marshal(in_sg, in_num, offset, bswap,
"w", str->size);
if (copied > 0) {
offset += copied;
copied = v9fs_pack(in_sg, in_num, offset, str->data, str->size);
}
break;
}
case 'Q': {
V9fsQID *qidp = va_arg(ap, V9fsQID *);
copied = v9fs_marshal(in_sg, in_num, offset, bswap, "bdq",
qidp->type, qidp->version, qidp->path);
break;
}
case 'S': {
V9fsStat *statp = va_arg(ap, V9fsStat *);
copied = v9fs_marshal(in_sg, in_num, offset, bswap,
"wwdQdddqsssssddd",
statp->size, statp->type, statp->dev,
&statp->qid, statp->mode, statp->atime,
statp->mtime, statp->length, &statp->name,
&statp->uid, &statp->gid, &statp->muid,
&statp->extension, statp->n_uid,
statp->n_gid, statp->n_muid);
break;
}
case 'A': {
V9fsStatDotl *statp = va_arg(ap, V9fsStatDotl *);
copied = v9fs_marshal(in_sg, in_num, offset, bswap,
"qQdddqqqqqqqqqqqqqqq",
statp->st_result_mask,
&statp->qid, statp->st_mode,
statp->st_uid, statp->st_gid,
statp->st_nlink, statp->st_rdev,
statp->st_size, statp->st_blksize,
statp->st_blocks, statp->st_atime_sec,
statp->st_atime_nsec, statp->st_mtime_sec,
statp->st_mtime_nsec, statp->st_ctime_sec,
statp->st_ctime_nsec, statp->st_btime_sec,
statp->st_btime_nsec, statp->st_gen,
statp->st_data_version);
break;
}
default:
break;
}
if (copied < 0) {
va_end(ap);
return copied;
}
offset += copied;
}
va_end(ap);
return offset - old_offset;
}