From 3872db0a227069d906614e5449833ca1d13e16c4 Mon Sep 17 00:00:00 2001

Message-Id: <3872db0a227069d906614e5449833ca1d13e16c4@dist-git>

From: Eric Blake <eblake@redhat.com>

Date: Wed, 26 Feb 2014 14:54:33 +0100

Subject: [PATCH] storage: use simpler 'char *'

https://bugzilla.redhat.com/show_bug.cgi?id=1032370

'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@redhat.com>

(cherry picked from commit 5717ee6ab871253c3e512ece7d59b754624e99c0)

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

---

 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 fc8aa90..bb27461 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;

@@ -679,7 +679,7 @@ virBackingStoreIsFile(const char *backing)

 static int

 virStorageFileProbeFormatFromBuf(const char *path,

-                                 unsigned char *buf,

+                                 char *buf,

                                  size_t buflen)

 {

     int format = VIR_STORAGE_FILE_RAW;

@@ -721,7 +721,7 @@ cleanup:

 static int

 qcow2GetFeatures(virBitmapPtr *features,

                  int format,

-                 unsigned char *buf,

+                 char *buf,

                  ssize_t len)

 {

     int version = -1;

@@ -762,7 +762,7 @@ 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;

@@ -914,7 +914,7 @@ 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;

-- 

1.9.0