11:10 p.m.
This makes code easier to read, by avoiding lines longer than
80 columns and removing the repetition from the callers.
* src/util/virstoragefile.c (virRead64BE, virRead64LE)
(virRead32BE, virRead32LE): New helper functions.
(qedGetHeaderUL, qedGetHeaderULL): Delete in favor of more generic
name.
(qcow2GetBackingStoreFormat, qcowXGetBackingStore)
(qedGetBackingStore, virStorageFileMatchesVersion)
(virStorageFileGetMetadataInternal): Use them.
---
src/util/virstoragefile.c | 159 +++++++++++++++++++++-------------------------
1 file changed, 72 insertions(+), 87 deletions(-)
diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
index 6e2d61e..e7ab226 100644
--- a/src/util/virstoragefile.c
+++ b/src/util/virstoragefile.c
@@ -208,6 +208,58 @@ static struct FileTypeInfo const fileTypeInfo[] = {
};
verify(ARRAY_CARDINALITY(fileTypeInfo) == VIR_STORAGE_FILE_LAST);
+/* Read 8 bytes at BUF as a big-endian 64-bit number. Caller is
+ responsible to avoid reading beyond array bounds. */
+static unsigned long long
+virRead64BE(const unsigned char *buf)
+{
+ return (((uint64_t)buf[0] << 56) |
+ ((uint64_t)buf[1] << 48) |
+ ((uint64_t)buf[2] << 40) |
+ ((uint64_t)buf[3] << 32) |
+ ((uint64_t)buf[4] << 24) |
+ ((uint64_t)buf[5] << 16) |
+ ((uint64_t)buf[6] << 8) |
+ (uint64_t)buf[7]);
+}
+
+/* Read 8 bytes at BUF as a little-endian 64-bit number. Caller is
+ responsible to avoid reading beyond array bounds. */
+static unsigned long long
+virRead64LE(const unsigned char *buf)
+{
+ return ((uint64_t)buf[0] |
+ ((uint64_t)buf[1] << 8) |
+ ((uint64_t)buf[2] << 16) |
+ ((uint64_t)buf[3] << 24) |
+ ((uint64_t)buf[4] << 32) |
+ ((uint64_t)buf[5] << 40) |
+ ((uint64_t)buf[6] << 48) |
+ ((uint64_t)buf[7] << 56));
+}
+
+/* Read 4 bytes at BUF as a big-endian 32-bit number. Caller is
+ responsible to avoid reading beyond array bounds. */
+static unsigned int
+virRead32BE(const unsigned char *buf)
+{
+ return ((buf[0] << 24) |
+ (buf[1] << 16) |
+ (buf[2] << 8) |
+ buf[3]);
+}
+
+/* Read 4 bytes at BUF as a little-endian 32-bit number. Caller is
+ responsible to avoid reading beyond array bounds. */
+static unsigned int
+virRead32LE(const unsigned char *buf)
+{
+ return (buf[0] |
+ (buf[1] << 8) |
+ (buf[2] << 16) |
+ (buf[3] << 24));
+}
+
static int
cowGetBackingStore(char **res,
int *format,
@@ -255,16 +307,8 @@ qcow2GetBackingStoreFormat(int *format,
*/
while (offset < (buf_size-8) &&
offset < (extension_end-8)) {
- unsigned int magic =
- (buf[offset] << 24) +
- (buf[offset+1] << 16) +
- (buf[offset+2] << 8) +
- (buf[offset+3]);
- unsigned int len =
- (buf[offset+4] << 24) +
- (buf[offset+5] << 16) +
- (buf[offset+6] << 8) +
- (buf[offset+7]);
+ unsigned int magic = virRead32BE(buf + offset);
+ unsigned int len = virRead32BE(buf + offset + 4);
offset += 8;
@@ -312,20 +356,10 @@ qcowXGetBackingStore(char **res,
if (buf_size < QCOWX_HDR_BACKING_FILE_OFFSET+8+4)
return BACKING_STORE_INVALID;
- offset = (((unsigned long long)buf[QCOWX_HDR_BACKING_FILE_OFFSET] << 56)
- | ((unsigned long long)buf[QCOWX_HDR_BACKING_FILE_OFFSET+1] << 48)
- | ((unsigned long long)buf[QCOWX_HDR_BACKING_FILE_OFFSET+2] << 40)
- | ((unsigned long long)buf[QCOWX_HDR_BACKING_FILE_OFFSET+3] << 32)
- | ((unsigned long long)buf[QCOWX_HDR_BACKING_FILE_OFFSET+4] << 24)
- | ((unsigned long long)buf[QCOWX_HDR_BACKING_FILE_OFFSET+5] << 16)
- | ((unsigned long long)buf[QCOWX_HDR_BACKING_FILE_OFFSET+6] << 8)
- | buf[QCOWX_HDR_BACKING_FILE_OFFSET+7]); /* QCowHeader.backing_file_offset
*/
+ offset = virRead64BE(buf + QCOWX_HDR_BACKING_FILE_OFFSET);
if (offset > buf_size)
return BACKING_STORE_INVALID;
- size = ((buf[QCOWX_HDR_BACKING_FILE_SIZE] << 24)
- | (buf[QCOWX_HDR_BACKING_FILE_SIZE+1] << 16)
- | (buf[QCOWX_HDR_BACKING_FILE_SIZE+2] << 8)
- | buf[QCOWX_HDR_BACKING_FILE_SIZE+3]); /* QCowHeader.backing_file_size */
+ size = virRead32BE(buf + QCOWX_HDR_BACKING_FILE_SIZE);
if (size == 0) {
if (format)
*format = VIR_STORAGE_FILE_NONE;
@@ -468,28 +502,6 @@ cleanup:
return ret;
}
-static unsigned long
-qedGetHeaderUL(const unsigned char *loc)
-{
- return (((unsigned long)loc[3] << 24) |
- ((unsigned long)loc[2] << 16) |
- ((unsigned long)loc[1] << 8) |
- ((unsigned long)loc[0] << 0));
-}
-
-static unsigned long long
-qedGetHeaderULL(const unsigned char *loc)
-{
- return (((unsigned long long)loc[7] << 56) |
- ((unsigned long long)loc[6] << 48) |
- ((unsigned long long)loc[5] << 40) |
- ((unsigned long long)loc[4] << 32) |
- ((unsigned long long)loc[3] << 24) |
- ((unsigned long long)loc[2] << 16) |
- ((unsigned long long)loc[1] << 8) |
- ((unsigned long long)loc[0] << 0));
-}
-
static int
qedGetBackingStore(char **res,
int *format,
@@ -503,7 +515,7 @@ qedGetBackingStore(char **res,
/* Check if this image has a backing file */
if (buf_size < QED_HDR_FEATURES_OFFSET+8)
return BACKING_STORE_INVALID;
- flags = qedGetHeaderULL(buf + QED_HDR_FEATURES_OFFSET);
+ flags = virRead64LE(buf + QED_HDR_FEATURES_OFFSET);
if (!(flags & QED_F_BACKING_FILE)) {
*format = VIR_STORAGE_FILE_NONE;
return BACKING_STORE_OK;
@@ -512,10 +524,10 @@ qedGetBackingStore(char **res,
/* Parse the backing file */
if (buf_size < QED_HDR_BACKING_FILE_OFFSET+8)
return BACKING_STORE_INVALID;
- offset = qedGetHeaderUL(buf + QED_HDR_BACKING_FILE_OFFSET);
+ offset = virRead32LE(buf + QED_HDR_BACKING_FILE_OFFSET);
if (offset > buf_size)
return BACKING_STORE_INVALID;
- size = qedGetHeaderUL(buf + QED_HDR_BACKING_FILE_SIZE);
+ size = virRead32LE(buf + QED_HDR_BACKING_FILE_SIZE);
if (size == 0)
return BACKING_STORE_OK;
if (offset + size > buf_size || offset + size < offset)
@@ -633,19 +645,10 @@ virStorageFileMatchesVersion(int format,
if ((fileTypeInfo[format].versionOffset + 4) > buflen)
return false;
- if (fileTypeInfo[format].endian == LV_LITTLE_ENDIAN) {
- version =
- (buf[fileTypeInfo[format].versionOffset+3] << 24) |
- (buf[fileTypeInfo[format].versionOffset+2] << 16) |
- (buf[fileTypeInfo[format].versionOffset+1] << 8) |
- (buf[fileTypeInfo[format].versionOffset]);
- } else {
- version =
- (buf[fileTypeInfo[format].versionOffset] << 24) |
- (buf[fileTypeInfo[format].versionOffset+1] << 16) |
- (buf[fileTypeInfo[format].versionOffset+2] << 8) |
- (buf[fileTypeInfo[format].versionOffset+3]);
- }
+ if (fileTypeInfo[format].endian == LV_LITTLE_ENDIAN)
+ version = virRead32LE(buf + fileTypeInfo[format].versionOffset);
+ else
+ version = virRead32BE(buf + fileTypeInfo[format].versionOffset);
VIR_DEBUG("Compare detected version %d vs expected version %d",
version, fileTypeInfo[format].versionNumber);
@@ -687,29 +690,15 @@ virStorageFileGetMetadataFromBuf(int format,
if ((fileTypeInfo[format].sizeOffset + 8) > buflen)
return 1;
- if (fileTypeInfo[format].endian == LV_LITTLE_ENDIAN) {
- meta->capacity =
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset+7] << 56)
|
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset+6] << 48)
|
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset+5] << 40)
|
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset+4] << 32)
|
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset+3] << 24)
|
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset+2] << 16)
|
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset+1] << 8)
|
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset]);
- } else {
- meta->capacity =
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset] << 56) |
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset+1] << 48)
|
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset+2] << 40)
|
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset+3] << 32)
|
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset+4] << 24)
|
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset+5] << 16)
|
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset+6] << 8)
|
- ((unsigned long long)buf[fileTypeInfo[format].sizeOffset+7]);
- }
+ if (fileTypeInfo[format].endian == LV_LITTLE_ENDIAN)
+ meta->capacity = virRead64LE(buf +
+ fileTypeInfo[format].sizeOffset);
+ else
+ meta->capacity = virRead64BE(buf +
+ fileTypeInfo[format].sizeOffset);
/* Avoid unlikely, but theoretically possible overflow */
- if (meta->capacity > (ULLONG_MAX / fileTypeInfo[format].sizeMultiplier))
+ if (meta->capacity > (ULLONG_MAX /
+ fileTypeInfo[format].sizeMultiplier))
return 1;
meta->capacity *= fileTypeInfo[format].sizeMultiplier;
}
@@ -717,11 +706,7 @@ virStorageFileGetMetadataFromBuf(int format,
if (fileTypeInfo[format].qcowCryptOffset != -1) {
int crypt_format;
- crypt_format =
- (buf[fileTypeInfo[format].qcowCryptOffset] << 24) |
- (buf[fileTypeInfo[format].qcowCryptOffset+1] << 16) |
- (buf[fileTypeInfo[format].qcowCryptOffset+2] << 8) |
- (buf[fileTypeInfo[format].qcowCryptOffset+3]);
+ crypt_format = virRead32BE(buf + fileTypeInfo[format].qcowCryptOffset);
meta->encrypted = crypt_format != 0;
}
--
1.8.1