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提交 a010fb58 编写于 作者: M Mark McLoughlin
浏览文件
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Move virStorageGetMetadataFromFD() to libvirt_util 

Finally, we get to the point of all this.

Move virStorageGetMetadataFromFD() to virStorageFileGetMetadataFromFD()
and move to src/util/storage_file.[ch]

There's no functional changes in this patch, just code movement

* src/storage/storage_backend_fs.c: move code from here ...

* src/util/storage_file.[ch]: ... to here

* src/libvirt_private.syms: export virStorageFileGetMetadataFromFD()
上级 5fede0a9
隐藏空白更改
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Showing with 380 addition and 367 deletion
src/libvirt_private.syms
浏览文件 @ a010fb58
...@@ -395,6 +395,7 @@ virStorageGenerateQcowPassphrase; ...@@ -395,6 +395,7 @@ virStorageGenerateQcowPassphrase;
# storage_file.h # storage_file.h
virStorageFileFormatTypeToString; virStorageFileFormatTypeToString;
virStorageFileFormatTypeFromString; virStorageFileFormatTypeFromString;
virStorageFileGetMetadataFromFD;
# threads.h # threads.h
virMutexInit; virMutexInit;
......
src/storage/storage_backend_fs.c
浏览文件 @ a010fb58
...@@ -46,374 +46,8 @@ ...@@ -46,374 +46,8 @@
#include "memory.h" #include "memory.h"
#include "xml.h" #include "xml.h"
enum lv_endian {
LV_LITTLE_ENDIAN = 1, /* 1234 */
LV_BIG_ENDIAN /* 4321 */
};
enum {
BACKING_STORE_OK,
BACKING_STORE_INVALID,
BACKING_STORE_ERROR,
};
static int cowGetBackingStore(virConnectPtr, char **,
const unsigned char *, size_t);
static int qcowXGetBackingStore(virConnectPtr, char **,
const unsigned char *, size_t);
static int vmdk4GetBackingStore(virConnectPtr, char **,
const unsigned char *, size_t);
/* Either 'magic' or 'extension' *must* be provided */
struct FileTypeInfo {
int type; /* One of the constants above */
const char *magic; /* Optional string of file magic
* to check at head of file */
const char *extension; /* Optional file extension to check */
enum lv_endian endian; /* Endianness of file format */
int versionOffset; /* Byte offset from start of file
* where we find version number,
* -1 to skip version test */
int versionNumber; /* Version number to validate */
int sizeOffset; /* Byte offset from start of file
* where we find capacity info,
* -1 to use st_size as capacity */
int sizeBytes; /* Number of bytes for size field */
int sizeMultiplier; /* A scaling factor if size is not in bytes */
/* Store a COW base image path (possibly relative),
* or NULL if there is no COW base image, to RES;
* return BACKING_STORE_* */
int qcowCryptOffset; /* Byte offset from start of file
* where to find encryption mode,
* -1 if encryption is not used */
int (*getBackingStore)(virConnectPtr conn, char **res,
const unsigned char *buf, size_t buf_size);
};
struct FileTypeInfo const fileTypeInfo[] = {
/* Bochs */
/* XXX Untested
{ VIR_STORAGE_FILE_BOCHS, "Bochs Virtual HD Image", NULL,
LV_LITTLE_ENDIAN, 64, 0x20000,
32+16+16+4+4+4+4+4, 8, 1, -1, NULL },*/
/* CLoop */
/* XXX Untested
{ VIR_STORAGE_VOL_CLOOP, "#!/bin/sh\n#V2.0 Format\nmodprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1\n", NULL,
LV_LITTLE_ENDIAN, -1, 0,
-1, 0, 0, -1, NULL }, */
/* Cow */
{ VIR_STORAGE_FILE_COW, "OOOM", NULL,
LV_BIG_ENDIAN, 4, 2,
4+4+1024+4, 8, 1, -1, cowGetBackingStore },
/* DMG */
/* XXX QEMU says there's no magic for dmg, but we should check... */
{ VIR_STORAGE_FILE_DMG, NULL, ".dmg",
0, -1, 0,
-1, 0, 0, -1, NULL },
/* XXX there's probably some magic for iso we can validate too... */
{ VIR_STORAGE_FILE_ISO, NULL, ".iso",
0, -1, 0,
-1, 0, 0, -1, NULL },
/* Parallels */
/* XXX Untested
{ VIR_STORAGE_FILE_PARALLELS, "WithoutFreeSpace", NULL,
LV_LITTLE_ENDIAN, 16, 2,
16+4+4+4+4, 4, 512, -1, NULL },
*/
/* QCow */
{ VIR_STORAGE_FILE_QCOW, "QFI", NULL,
LV_BIG_ENDIAN, 4, 1,
4+4+8+4+4, 8, 1, 4+4+8+4+4+8+1+1+2, qcowXGetBackingStore },
/* QCow 2 */
{ VIR_STORAGE_FILE_QCOW2, "QFI", NULL,
LV_BIG_ENDIAN, 4, 2,
4+4+8+4+4, 8, 1, 4+4+8+4+4+8, qcowXGetBackingStore },
/* VMDK 3 */
/* XXX Untested
{ VIR_STORAGE_FILE_VMDK, "COWD", NULL,
LV_LITTLE_ENDIAN, 4, 1,
4+4+4, 4, 512, -1, NULL },
*/
/* VMDK 4 */
{ VIR_STORAGE_FILE_VMDK, "KDMV", NULL,
LV_LITTLE_ENDIAN, 4, 1,
4+4+4, 8, 512, -1, vmdk4GetBackingStore },
/* Connectix / VirtualPC */
/* XXX Untested
{ VIR_STORAGE_FILE_VPC, "conectix", NULL,
LV_BIG_ENDIAN, -1, 0,
-1, 0, 0, -1, NULL},
*/
};
#define VIR_FROM_THIS VIR_FROM_STORAGE #define VIR_FROM_THIS VIR_FROM_STORAGE
static int
cowGetBackingStore(virConnectPtr conn,
char **res,
const unsigned char *buf,
size_t buf_size)
{
#define COW_FILENAME_MAXLEN 1024
*res = NULL;
if (buf_size < 4+4+ COW_FILENAME_MAXLEN)
return BACKING_STORE_INVALID;
if (buf[4+4] == '\0') /* cow_header_v2.backing_file[0] */
return BACKING_STORE_OK;
*res = strndup ((const char*)buf + 4+4, COW_FILENAME_MAXLEN);
if (*res == NULL) {
virReportOOMError(conn);
return BACKING_STORE_ERROR;
}
return BACKING_STORE_OK;
}
static int
qcowXGetBackingStore(virConnectPtr conn,
char **res,
const unsigned char *buf,
size_t buf_size)
{
unsigned long long offset;
unsigned long size;
*res = NULL;
if (buf_size < 4+4+8+4)
return BACKING_STORE_INVALID;
offset = (((unsigned long long)buf[4+4] << 56)
| ((unsigned long long)buf[4+4+1] << 48)
| ((unsigned long long)buf[4+4+2] << 40)
| ((unsigned long long)buf[4+4+3] << 32)
| ((unsigned long long)buf[4+4+4] << 24)
| ((unsigned long long)buf[4+4+5] << 16)
| ((unsigned long long)buf[4+4+6] << 8)
| buf[4+4+7]); /* QCowHeader.backing_file_offset */
if (offset > buf_size)
return BACKING_STORE_INVALID;
size = ((buf[4+4+8] << 24)
| (buf[4+4+8+1] << 16)
| (buf[4+4+8+2] << 8)
| buf[4+4+8+3]); /* QCowHeader.backing_file_size */
if (size == 0)
return BACKING_STORE_OK;
if (offset + size > buf_size || offset + size < offset)
return BACKING_STORE_INVALID;
if (size + 1 == 0)
return BACKING_STORE_INVALID;
if (VIR_ALLOC_N(*res, size + 1) < 0) {
virReportOOMError(conn);
return BACKING_STORE_ERROR;
}
memcpy(*res, buf + offset, size);
(*res)[size] = '\0';
return BACKING_STORE_OK;
}
static int
vmdk4GetBackingStore(virConnectPtr conn,
char **res,
const unsigned char *buf,
size_t buf_size)
{
static const char prefix[] = "parentFileNameHint=\"";
char desc[20*512 + 1], *start, *end;
size_t len;
*res = NULL;
if (buf_size <= 0x200)
return BACKING_STORE_INVALID;
len = buf_size - 0x200;
if (len > sizeof(desc) - 1)
len = sizeof(desc) - 1;
memcpy(desc, buf + 0x200, len);
desc[len] = '\0';
start = strstr(desc, prefix);
if (start == NULL)
return BACKING_STORE_OK;
start += strlen(prefix);
end = strchr(start, '"');
if (end == NULL)
return BACKING_STORE_INVALID;
if (end == start)
return BACKING_STORE_OK;
*end = '\0';
*res = strdup(start);
if (*res == NULL) {
virReportOOMError(conn);
return BACKING_STORE_ERROR;
}
return BACKING_STORE_OK;
}
/**
* Return an absolute path corresponding to PATH, which is absolute or relative
* to the directory containing BASE_FILE, or NULL on error
*/
static char *absolutePathFromBaseFile(const char *base_file, const char *path)
{
size_t base_size, path_size;
char *res, *p;
if (*path == '/')
return strdup(path);
base_size = strlen(base_file) + 1;
path_size = strlen(path) + 1;
if (VIR_ALLOC_N(res, base_size - 1 + path_size) < 0)
return NULL;
memcpy(res, base_file, base_size);
p = strrchr(res, '/');
if (p != NULL)
p++;
else
p = res;
memcpy(p, path, path_size);
if (VIR_REALLOC_N(res, (p + path_size) - res) < 0) {
/* Ignore failure */
}
return res;
}
/**
* Probe the header of a file to determine what type of disk image
* it is, and info about its capacity if available.
*/
static int
virStorageGetMetadataFromFD(virConnectPtr conn,
const char *path,
int fd,
virStorageFileMetadata *meta)
{
unsigned char head[20*512]; /* vmdk4GetBackingStore needs this much. */
int len, i;
/* If all else fails, call it a raw file */
meta->format = VIR_STORAGE_FILE_RAW;
if ((len = read(fd, head, sizeof(head))) < 0) {
virReportSystemError(conn, errno, _("cannot read header '%s'"), path);
return -1;
}
/* First check file magic */
for (i = 0 ; i < ARRAY_CARDINALITY(fileTypeInfo) ; i++) {
int mlen;
if (fileTypeInfo[i].magic == NULL)
continue;
/* Validate magic data */
mlen = strlen(fileTypeInfo[i].magic);
if (mlen > len)
continue;
if (memcmp(head, fileTypeInfo[i].magic, mlen) != 0)
continue;
/* Validate version number info */
if (fileTypeInfo[i].versionNumber != -1) {
int version;
if (fileTypeInfo[i].endian == LV_LITTLE_ENDIAN) {
version = (head[fileTypeInfo[i].versionOffset+3] << 24) |
(head[fileTypeInfo[i].versionOffset+2] << 16) |
(head[fileTypeInfo[i].versionOffset+1] << 8) |
head[fileTypeInfo[i].versionOffset];
} else {
version = (head[fileTypeInfo[i].versionOffset] << 24) |
(head[fileTypeInfo[i].versionOffset+1] << 16) |
(head[fileTypeInfo[i].versionOffset+2] << 8) |
head[fileTypeInfo[i].versionOffset+3];
}
if (version != fileTypeInfo[i].versionNumber)
continue;
}
/* Optionally extract capacity from file */
if (fileTypeInfo[i].sizeOffset != -1) {
if (fileTypeInfo[i].endian == LV_LITTLE_ENDIAN) {
meta->capacity =
((unsigned long long)head[fileTypeInfo[i].sizeOffset+7] << 56) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+6] << 48) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+5] << 40) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+4] << 32) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+3] << 24) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+2] << 16) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+1] << 8) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset]);
} else {
meta->capacity =
((unsigned long long)head[fileTypeInfo[i].sizeOffset] << 56) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+1] << 48) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+2] << 40) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+3] << 32) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+4] << 24) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+5] << 16) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+6] << 8) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+7]);
}
/* Avoid unlikely, but theoretically possible overflow */
if (meta->capacity > (ULLONG_MAX / fileTypeInfo[i].sizeMultiplier))
continue;
meta->capacity *= fileTypeInfo[i].sizeMultiplier;
}
if (fileTypeInfo[i].qcowCryptOffset != -1) {
int crypt_format;
crypt_format = (head[fileTypeInfo[i].qcowCryptOffset] << 24) |
(head[fileTypeInfo[i].qcowCryptOffset+1] << 16) |
(head[fileTypeInfo[i].qcowCryptOffset+2] << 8) |
head[fileTypeInfo[i].qcowCryptOffset+3];
meta->encrypted = crypt_format != 0;
}
/* Validation passed, we know the file format now */
meta->format = fileTypeInfo[i].type;
if (fileTypeInfo[i].getBackingStore != NULL) {
char *base;
switch (fileTypeInfo[i].getBackingStore(conn, &base, head, len)) {
case BACKING_STORE_OK:
break;
case BACKING_STORE_INVALID:
continue;
case BACKING_STORE_ERROR:
return -1;
}
if (base != NULL) {
meta->backingStore = absolutePathFromBaseFile(path, base);
VIR_FREE(base);
if (meta->backingStore == NULL) {
virReportOOMError(conn);
return -1;
}
}
}
return 0;
}
/* No magic, so check file extension */
for (i = 0 ; i < ARRAY_CARDINALITY(fileTypeInfo) ; i++) {
if (fileTypeInfo[i].extension == NULL)
continue;
if (!virFileHasSuffix(path, fileTypeInfo[i].extension))
continue;
meta->format = fileTypeInfo[i].type;
return 0;
}
return 0;
}
static int static int
virStorageBackendProbeTarget(virConnectPtr conn, virStorageBackendProbeTarget(virConnectPtr conn,
virStorageVolTargetPtr target, virStorageVolTargetPtr target,
...@@ -444,7 +78,7 @@ virStorageBackendProbeTarget(virConnectPtr conn, ...@@ -444,7 +78,7 @@ virStorageBackendProbeTarget(virConnectPtr conn,
memset(&meta, 0, sizeof(meta)); memset(&meta, 0, sizeof(meta));
if (virStorageGetMetadataFromFD(conn, target->path, fd, &meta) < 0) { if (virStorageFileGetMetadataFromFD(conn, target->path, fd, &meta) < 0) {
close(fd); close(fd);
return -1; return -1;
} }
......
src/util/storage_file.c
浏览文件 @ a010fb58
...@@ -24,8 +24,381 @@ ...@@ -24,8 +24,381 @@
#include <config.h> #include <config.h>
#include "storage_file.h" #include "storage_file.h"
#include <unistd.h>
#include "memory.h"
#include "virterror_internal.h"
#define VIR_FROM_THIS VIR_FROM_STORAGE
VIR_ENUM_IMPL(virStorageFileFormat, VIR_ENUM_IMPL(virStorageFileFormat,
VIR_STORAGE_FILE_LAST, VIR_STORAGE_FILE_LAST,
"raw", "dir", "bochs", "raw", "dir", "bochs",
"cloop", "cow", "dmg", "iso", "cloop", "cow", "dmg", "iso",
"qcow", "qcow2", "vmdk", "vpc") "qcow", "qcow2", "vmdk", "vpc")
enum lv_endian {
LV_LITTLE_ENDIAN = 1, /* 1234 */
LV_BIG_ENDIAN /* 4321 */
};
enum {
BACKING_STORE_OK,
BACKING_STORE_INVALID,
BACKING_STORE_ERROR,
};
/* Either 'magic' or 'extension' *must* be provided */
struct FileTypeInfo {
int type; /* One of the constants above */
const char *magic; /* Optional string of file magic
* to check at head of file */
const char *extension; /* Optional file extension to check */
enum lv_endian endian; /* Endianness of file format */
int versionOffset; /* Byte offset from start of file
* where we find version number,
* -1 to skip version test */
int versionNumber; /* Version number to validate */
int sizeOffset; /* Byte offset from start of file
* where we find capacity info,
* -1 to use st_size as capacity */
int sizeBytes; /* Number of bytes for size field */
int sizeMultiplier; /* A scaling factor if size is not in bytes */
/* Store a COW base image path (possibly relative),
* or NULL if there is no COW base image, to RES;
* return BACKING_STORE_* */
int qcowCryptOffset; /* Byte offset from start of file
* where to find encryption mode,
* -1 if encryption is not used */
int (*getBackingStore)(virConnectPtr conn, char **res,
const unsigned char *buf, size_t buf_size);
};
static int cowGetBackingStore(virConnectPtr, char **,
const unsigned char *, size_t);
static int qcowXGetBackingStore(virConnectPtr, char **,
const unsigned char *, size_t);
static int vmdk4GetBackingStore(virConnectPtr, char **,
const unsigned char *, size_t);
static struct FileTypeInfo const fileTypeInfo[] = {
/* Bochs */
/* XXX Untested
{ VIR_STORAGE_FILE_BOCHS, "Bochs Virtual HD Image", NULL,
LV_LITTLE_ENDIAN, 64, 0x20000,
32+16+16+4+4+4+4+4, 8, 1, -1, NULL },*/
/* CLoop */
/* XXX Untested
{ VIR_STORAGE_VOL_CLOOP, "#!/bin/sh\n#V2.0 Format\nmodprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1\n", NULL,
LV_LITTLE_ENDIAN, -1, 0,
-1, 0, 0, -1, NULL }, */
/* Cow */
{ VIR_STORAGE_FILE_COW, "OOOM", NULL,
LV_BIG_ENDIAN, 4, 2,
4+4+1024+4, 8, 1, -1, cowGetBackingStore },
/* DMG */
/* XXX QEMU says there's no magic for dmg, but we should check... */
{ VIR_STORAGE_FILE_DMG, NULL, ".dmg",
0, -1, 0,
-1, 0, 0, -1, NULL },
/* XXX there's probably some magic for iso we can validate too... */
{ VIR_STORAGE_FILE_ISO, NULL, ".iso",
0, -1, 0,
-1, 0, 0, -1, NULL },
/* Parallels */
/* XXX Untested
{ VIR_STORAGE_FILE_PARALLELS, "WithoutFreeSpace", NULL,
LV_LITTLE_ENDIAN, 16, 2,
16+4+4+4+4, 4, 512, -1, NULL },
*/
/* QCow */
{ VIR_STORAGE_FILE_QCOW, "QFI", NULL,
LV_BIG_ENDIAN, 4, 1,
4+4+8+4+4, 8, 1, 4+4+8+4+4+8+1+1+2, qcowXGetBackingStore },
/* QCow 2 */
{ VIR_STORAGE_FILE_QCOW2, "QFI", NULL,
LV_BIG_ENDIAN, 4, 2,
4+4+8+4+4, 8, 1, 4+4+8+4+4+8, qcowXGetBackingStore },
/* VMDK 3 */
/* XXX Untested
{ VIR_STORAGE_FILE_VMDK, "COWD", NULL,
LV_LITTLE_ENDIAN, 4, 1,
4+4+4, 4, 512, -1, NULL },
*/
/* VMDK 4 */
{ VIR_STORAGE_FILE_VMDK, "KDMV", NULL,
LV_LITTLE_ENDIAN, 4, 1,
4+4+4, 8, 512, -1, vmdk4GetBackingStore },
/* Connectix / VirtualPC */
/* XXX Untested
{ VIR_STORAGE_FILE_VPC, "conectix", NULL,
LV_BIG_ENDIAN, -1, 0,
-1, 0, 0, -1, NULL},
*/
};
static int
cowGetBackingStore(virConnectPtr conn,
char **res,
const unsigned char *buf,
size_t buf_size)
{
#define COW_FILENAME_MAXLEN 1024
*res = NULL;
if (buf_size < 4+4+ COW_FILENAME_MAXLEN)
return BACKING_STORE_INVALID;
if (buf[4+4] == '\0') /* cow_header_v2.backing_file[0] */
return BACKING_STORE_OK;
*res = strndup ((const char*)buf + 4+4, COW_FILENAME_MAXLEN);
if (*res == NULL) {
virReportOOMError(conn);
return BACKING_STORE_ERROR;
}
return BACKING_STORE_OK;
}
static int
qcowXGetBackingStore(virConnectPtr conn,
char **res,
const unsigned char *buf,
size_t buf_size)
{
unsigned long long offset;
unsigned long size;
*res = NULL;
if (buf_size < 4+4+8+4)
return BACKING_STORE_INVALID;
offset = (((unsigned long long)buf[4+4] << 56)
| ((unsigned long long)buf[4+4+1] << 48)
| ((unsigned long long)buf[4+4+2] << 40)
| ((unsigned long long)buf[4+4+3] << 32)
| ((unsigned long long)buf[4+4+4] << 24)
| ((unsigned long long)buf[4+4+5] << 16)
| ((unsigned long long)buf[4+4+6] << 8)
| buf[4+4+7]); /* QCowHeader.backing_file_offset */
if (offset > buf_size)
return BACKING_STORE_INVALID;
size = ((buf[4+4+8] << 24)
| (buf[4+4+8+1] << 16)
| (buf[4+4+8+2] << 8)
| buf[4+4+8+3]); /* QCowHeader.backing_file_size */
if (size == 0)
return BACKING_STORE_OK;
if (offset + size > buf_size || offset + size < offset)
return BACKING_STORE_INVALID;
if (size + 1 == 0)
return BACKING_STORE_INVALID;
if (VIR_ALLOC_N(*res, size + 1) < 0) {
virReportOOMError(conn);
return BACKING_STORE_ERROR;
}
memcpy(*res, buf + offset, size);
(*res)[size] = '\0';
return BACKING_STORE_OK;
}
static int
vmdk4GetBackingStore(virConnectPtr conn,
char **res,
const unsigned char *buf,
size_t buf_size)
{
static const char prefix[] = "parentFileNameHint=\"";
char desc[20*512 + 1], *start, *end;
size_t len;
*res = NULL;
if (buf_size <= 0x200)
return BACKING_STORE_INVALID;
len = buf_size - 0x200;
if (len > sizeof(desc) - 1)
len = sizeof(desc) - 1;
memcpy(desc, buf + 0x200, len);
desc[len] = '\0';
start = strstr(desc, prefix);
if (start == NULL)
return BACKING_STORE_OK;
start += strlen(prefix);
end = strchr(start, '"');
if (end == NULL)
return BACKING_STORE_INVALID;
if (end == start)
return BACKING_STORE_OK;
*end = '\0';
*res = strdup(start);
if (*res == NULL) {
virReportOOMError(conn);
return BACKING_STORE_ERROR;
}
return BACKING_STORE_OK;
}
/**
* Return an absolute path corresponding to PATH, which is absolute or relative
* to the directory containing BASE_FILE, or NULL on error
*/
static char *
absolutePathFromBaseFile(const char *base_file, const char *path)
{
size_t base_size, path_size;
char *res, *p;
if (*path == '/')
return strdup(path);
base_size = strlen(base_file) + 1;
path_size = strlen(path) + 1;
if (VIR_ALLOC_N(res, base_size - 1 + path_size) < 0)
return NULL;
memcpy(res, base_file, base_size);
p = strrchr(res, '/');
if (p != NULL)
p++;
else
p = res;
memcpy(p, path, path_size);
if (VIR_REALLOC_N(res, (p + path_size) - res) < 0) {
/* Ignore failure */
}
return res;
}
/**
* Probe the header of a file to determine what type of disk image
* it is, and info about its capacity if available.
*/
int
virStorageFileGetMetadataFromFD(virConnectPtr conn,
const char *path,
int fd,
virStorageFileMetadata *meta)
{
unsigned char head[20*512]; /* vmdk4GetBackingStore needs this much. */
int len, i;
/* If all else fails, call it a raw file */
meta->format = VIR_STORAGE_FILE_RAW;
if ((len = read(fd, head, sizeof(head))) < 0) {
virReportSystemError(conn, errno, _("cannot read header '%s'"), path);
return -1;
}
/* First check file magic */
for (i = 0 ; i < ARRAY_CARDINALITY(fileTypeInfo) ; i++) {
int mlen;
if (fileTypeInfo[i].magic == NULL)
continue;
/* Validate magic data */
mlen = strlen(fileTypeInfo[i].magic);
if (mlen > len)
continue;
if (memcmp(head, fileTypeInfo[i].magic, mlen) != 0)
continue;
/* Validate version number info */
if (fileTypeInfo[i].versionNumber != -1) {
int version;
if (fileTypeInfo[i].endian == LV_LITTLE_ENDIAN) {
version = (head[fileTypeInfo[i].versionOffset+3] << 24) |
(head[fileTypeInfo[i].versionOffset+2] << 16) |
(head[fileTypeInfo[i].versionOffset+1] << 8) |
head[fileTypeInfo[i].versionOffset];
} else {
version = (head[fileTypeInfo[i].versionOffset] << 24) |
(head[fileTypeInfo[i].versionOffset+1] << 16) |
(head[fileTypeInfo[i].versionOffset+2] << 8) |
head[fileTypeInfo[i].versionOffset+3];
}
if (version != fileTypeInfo[i].versionNumber)
continue;
}
/* Optionally extract capacity from file */
if (fileTypeInfo[i].sizeOffset != -1) {
if (fileTypeInfo[i].endian == LV_LITTLE_ENDIAN) {
meta->capacity =
((unsigned long long)head[fileTypeInfo[i].sizeOffset+7] << 56) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+6] << 48) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+5] << 40) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+4] << 32) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+3] << 24) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+2] << 16) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+1] << 8) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset]);
} else {
meta->capacity =
((unsigned long long)head[fileTypeInfo[i].sizeOffset] << 56) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+1] << 48) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+2] << 40) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+3] << 32) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+4] << 24) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+5] << 16) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+6] << 8) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+7]);
}
/* Avoid unlikely, but theoretically possible overflow */
if (meta->capacity > (ULLONG_MAX / fileTypeInfo[i].sizeMultiplier))
continue;
meta->capacity *= fileTypeInfo[i].sizeMultiplier;
}
if (fileTypeInfo[i].qcowCryptOffset != -1) {
int crypt_format;
crypt_format = (head[fileTypeInfo[i].qcowCryptOffset] << 24) |
(head[fileTypeInfo[i].qcowCryptOffset+1] << 16) |
(head[fileTypeInfo[i].qcowCryptOffset+2] << 8) |
head[fileTypeInfo[i].qcowCryptOffset+3];
meta->encrypted = crypt_format != 0;
}
/* Validation passed, we know the file format now */
meta->format = fileTypeInfo[i].type;
if (fileTypeInfo[i].getBackingStore != NULL) {
char *base;
switch (fileTypeInfo[i].getBackingStore(conn, &base, head, len)) {
case BACKING_STORE_OK:
break;
case BACKING_STORE_INVALID:
continue;
case BACKING_STORE_ERROR:
return -1;
}
if (base != NULL) {
meta->backingStore = absolutePathFromBaseFile(path, base);
VIR_FREE(base);
if (meta->backingStore == NULL) {
virReportOOMError(conn);
return -1;
}
}
}
return 0;
}
/* No magic, so check file extension */
for (i = 0 ; i < ARRAY_CARDINALITY(fileTypeInfo) ; i++) {
if (fileTypeInfo[i].extension == NULL)
continue;
if (!virFileHasSuffix(path, fileTypeInfo[i].extension))
continue;
meta->format = fileTypeInfo[i].type;
return 0;
}
return 0;
}
src/util/storage_file.h
浏览文件 @ a010fb58
...@@ -51,4 +51,9 @@ typedef struct _virStorageFileMetadata { ...@@ -51,4 +51,9 @@ typedef struct _virStorageFileMetadata {
bool encrypted; bool encrypted;
} virStorageFileMetadata; } virStorageFileMetadata;
int virStorageFileGetMetadataFromFD(virConnectPtr conn,
const char *path,
int fd,
virStorageFileMetadata *meta);
#endif /* __VIR_STORAGE_FILE_H__ */ #endif /* __VIR_STORAGE_FILE_H__ */
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