[libvirt] [PATCH 4/6] Move virStorageGetMetadataFromFD() to libvirt_util
Mark McLoughlin
markmc at redhat.com
Tue Sep 29 08:56:47 UTC 2009
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()
---
src/libvirt_private.syms | 1 +
src/storage/storage_backend_fs.c | 368 +-------------------------------------
src/util/storage_file.c | 373 ++++++++++++++++++++++++++++++++++++++
src/util/storage_file.h | 5 +
4 files changed, 380 insertions(+), 367 deletions(-)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index ddab21d..4890032 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -393,6 +393,7 @@ virStorageGenerateQcowPassphrase;
# storage_file.h
virStorageFileFormatTypeToString;
virStorageFileFormatTypeFromString;
+virStorageFileGetMetadataFromFD;
# threads.h
virMutexInit;
diff --git a/src/storage/storage_backend_fs.c b/src/storage/storage_backend_fs.c
index 7db73bf..6816da8 100644
--- a/src/storage/storage_backend_fs.c
+++ b/src/storage/storage_backend_fs.c
@@ -46,375 +46,9 @@
#include "memory.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
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
virStorageBackendProbeTarget(virConnectPtr conn,
virStorageVolTargetPtr target,
char **backingStore,
@@ -444,7 +78,7 @@ virStorageBackendProbeTarget(virConnectPtr conn,
memset(&meta, 0, sizeof(meta));
- if (virStorageGetMetadataFromFD(conn, target->path, fd, &meta) < 0) {
+ if (virStorageFileGetMetadataFromFD(conn, target->path, fd, &meta) < 0) {
close(fd);
return -1;
}
diff --git a/src/util/storage_file.c b/src/util/storage_file.c
index e66ec8a..e674713 100644
--- a/src/util/storage_file.c
+++ b/src/util/storage_file.c
@@ -24,8 +24,381 @@
#include <config.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_STORAGE_FILE_LAST,
"raw", "dir", "bochs",
"cloop", "cow", "dmg", "iso",
"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;
+}
diff --git a/src/util/storage_file.h b/src/util/storage_file.h
index b458c0e..e34d749 100644
--- a/src/util/storage_file.h
+++ b/src/util/storage_file.h
@@ -51,4 +51,9 @@ typedef struct _virStorageFileMetadata {
bool encrypted;
} virStorageFileMetadata;
+int virStorageFileGetMetadataFromFD(virConnectPtr conn,
+ const char *path,
+ int fd,
+ virStorageFileMetadata *meta);
+
#endif /* __VIR_STORAGE_FILE_H__ */
--
1.6.2.5
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