[libvirt] [PATCH 1/3] storage: use simpler 'char *'

'unsigned char *' makes sense if you are doing math on bytes and don't want to worry about wraparound from a signed 'char'; but since all we are doing is memcmp() or virReadBufInt*[LB]E(), which are both safe on either type of char, and since read() prefers to operate on 'char *', it's simpler to avoid casts by just typing things as 'char *' from the get-go. [Technically, read can operate on an 'unsigned char *' thanks to the C rule that any pointer can be implicitly converted to 'char *' for legacy K&R compatibility; but where this patch saves us is if we try to use virfile.h functions that take 'char **' in order to allocate the buffer, where the compiler would barf on type mismatch.] * src/util/virstoragefile.c (FileTypeInfo): Avoid unsigned char. (cowGetBackingStore, qcow2GetBackingStoreFormat) (qcowXGetBackingStore, qcow1GetBackingStore) (qcow2GetBackingStore, vmdk4GetBackingStore, qedGetBackingStore) (virStorageFileMatchesMagic, virStorageFileMatchesVersion) (virStorageFileProbeFormatFromBuf, qcow2GetFeatures) (virStorageFileGetMetadataInternal) (virStorageFileProbeFormatFromFD): Simplify clients. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- src/util/virstoragefile.c | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-) diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c index 8f04b78..589778c 100644 --- a/src/util/virstoragefile.c +++ b/src/util/virstoragefile.c @@ -102,23 +102,23 @@ struct FileTypeInfo { * where to find encryption mode, * -1 if encryption is not used */ int (*getBackingStore)(char **res, int *format, - const unsigned char *buf, size_t buf_size); + const char *buf, size_t buf_size); int (*getFeatures)(virBitmapPtr *features, int format, - unsigned char *buf, ssize_t len); + char *buf, ssize_t len); }; static int cowGetBackingStore(char **, int *, - const unsigned char *, size_t); + const char *, size_t); static int qcow1GetBackingStore(char **, int *, - const unsigned char *, size_t); + const char *, size_t); static int qcow2GetBackingStore(char **, int *, - const unsigned char *, size_t); + const char *, size_t); static int qcow2GetFeatures(virBitmapPtr *features, int format, - unsigned char *buf, ssize_t len); + char *buf, ssize_t len); static int vmdk4GetBackingStore(char **, int *, - const unsigned char *, size_t); + const char *, size_t); static int -qedGetBackingStore(char **, int *, const unsigned char *, size_t); +qedGetBackingStore(char **, int *, const char *, size_t); #define QCOWX_HDR_VERSION (4) #define QCOWX_HDR_BACKING_FILE_OFFSET (QCOWX_HDR_VERSION+4) @@ -252,7 +252,7 @@ verify(ARRAY_CARDINALITY(qcow2CompatibleFeatureArray) == static int cowGetBackingStore(char **res, int *format, - const unsigned char *buf, + const char *buf, size_t buf_size) { #define COW_FILENAME_MAXLEN 1024 @@ -274,7 +274,7 @@ cowGetBackingStore(char **res, static int qcow2GetBackingStoreFormat(int *format, - const unsigned char *buf, + const char *buf, size_t buf_size, size_t extension_start, size_t extension_end) @@ -329,7 +329,7 @@ done: static int qcowXGetBackingStore(char **res, int *format, - const unsigned char *buf, + const char *buf, size_t buf_size, bool isQCow2) { @@ -407,7 +407,7 @@ qcowXGetBackingStore(char **res, static int qcow1GetBackingStore(char **res, int *format, - const unsigned char *buf, + const char *buf, size_t buf_size) { int ret; @@ -424,7 +424,7 @@ qcow1GetBackingStore(char **res, static int qcow2GetBackingStore(char **res, int *format, - const unsigned char *buf, + const char *buf, size_t buf_size) { return qcowXGetBackingStore(res, format, buf, buf_size, true); @@ -434,7 +434,7 @@ qcow2GetBackingStore(char **res, static int vmdk4GetBackingStore(char **res, int *format, - const unsigned char *buf, + const char *buf, size_t buf_size) { static const char prefix[] = "parentFileNameHint=\""; @@ -495,7 +495,7 @@ cleanup: static int qedGetBackingStore(char **res, int *format, - const unsigned char *buf, + const char *buf, size_t buf_size) { unsigned long long flags; @@ -596,7 +596,7 @@ cleanup: static bool virStorageFileMatchesMagic(int format, - unsigned char *buf, + char *buf, size_t buflen) { int mlen; @@ -634,7 +634,7 @@ virStorageFileMatchesExtension(int format, static bool virStorageFileMatchesVersion(int format, - unsigned char *buf, + char *buf, size_t buflen) { int version; @@ -684,7 +684,7 @@ virBackingStoreIsFile(const char *backing) static int virStorageFileProbeFormatFromBuf(const char *path, - unsigned char *buf, + char *buf, size_t buflen) { int format = VIR_STORAGE_FILE_RAW; @@ -726,7 +726,7 @@ cleanup: static int qcow2GetFeatures(virBitmapPtr *features, int format, - unsigned char *buf, + char *buf, ssize_t len) { int version = -1; @@ -767,7 +767,7 @@ virStorageFileGetMetadataInternal(const char *path, int format) { virStorageFileMetadata *meta = NULL; - unsigned char *buf = NULL; + char *buf = NULL; ssize_t len = STORAGE_MAX_HEAD; virStorageFileMetadata *ret = NULL; struct stat sb; @@ -922,7 +922,7 @@ cleanup: int virStorageFileProbeFormatFromFD(const char *path, int fd) { - unsigned char *head; + char *head = NULL; ssize_t len = STORAGE_MAX_HEAD; int ret = -1; struct stat sb; -- 1.8.3.1