probing fixes

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1425 c046a42c-6fe2-441c-8c8c-71466251a162

block-cow.c

@@ -54,7 +54,8 @@ static int cow_probe(const uint8_t *buf, int buf_size, const char *filename)
 {
     const struct cow_header_v2 *cow_header = (const void *)buf;
 
-    if (be32_to_cpu(cow_header->magic) == COW_MAGIC &&
+    if (buf_size >= sizeof(struct cow_header_v2) &&
+        be32_to_cpu(cow_header->magic) == COW_MAGIC &&
         be32_to_cpu(cow_header->version) == COW_VERSION) 
         return 100;
     else

block-qcow.c

@@ -80,8 +80,9 @@ static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset);
 static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
 {
     const QCowHeader *cow_header = (const void *)buf;
-
-    if (be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
+    
+    if (buf_size >= sizeof(QCowHeader) &&
+        be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
         be32_to_cpu(cow_header->version) == QCOW_VERSION) 
         return 100;
     else
@@ -551,9 +552,19 @@ static int qcow_create(const char *filename, int64_t total_size,
     header_size = sizeof(header);
     backing_filename_len = 0;
     if (backing_file) {
-        realpath(backing_file, backing_filename);
-        if (stat(backing_filename, &st) != 0) {
-            return -1;
+        const char *p;
+        /* XXX: this is a hack: we do not attempt to check for URL
+           like syntax */
+        p = strchr(backing_file, ':');
+        if (p && (p - backing_file) >= 2) {
+            /* URL like but exclude "c:" like filenames */
+            pstrcpy(backing_filename, sizeof(backing_filename),
+                    backing_file);
+        } else {
+            realpath(backing_file, backing_filename);
+            if (stat(backing_filename, &st) != 0) {
+                return -1;
+            }
         }
         header.mtime = cpu_to_be32(st.st_mtime);
         header.backing_file_offset = cpu_to_be64(header_size);

block-vpc.c

@@ -81,9 +81,8 @@ typedef struct BDRVVPCState {
 
 static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename)
 {
-    if (!strncmp(buf, "conectix", 8))
+    if (buf_size >= 8 && !strncmp(buf, "conectix", 8))
 	return 100;
-
     return 0;
 }
 

block.c

@@ -106,26 +106,29 @@ static BlockDriver *find_image_format(const char *filename)
     size_t bufsize = 1024;
 
     fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);
-    if (fd < 0)
-        return NULL;
+    if (fd < 0) {
+        buf = NULL;
+        ret = 0;
+    } else {
 #ifdef DIOCGSECTORSIZE
-    {
-        unsigned int sectorsize = 512;
-        if (!ioctl(fd, DIOCGSECTORSIZE, &sectorsize) &&
-            sectorsize > bufsize)
-            bufsize = sectorsize;
-    }
+        {
+            unsigned int sectorsize = 512;
+            if (!ioctl(fd, DIOCGSECTORSIZE, &sectorsize) &&
+                sectorsize > bufsize)
+                bufsize = sectorsize;
+        }
 #endif
-    buf = malloc(bufsize);
-    if (!buf)
-        return NULL;
-    ret = read(fd, buf, bufsize);
-    if (ret < 0) {
+        buf = qemu_malloc(bufsize);
+        if (!buf)
+            return NULL;
+        ret = read(fd, buf, bufsize);
+        if (ret < 0) {
+            close(fd);
+            qemu_free(buf);
+            return NULL;
+        }
         close(fd);
-        free(buf);
-        return NULL;
     }
-    close(fd);
     
     drv = NULL;
     score_max = 0;
@@ -136,7 +139,7 @@ static BlockDriver *find_image_format(const char *filename)
             drv = drv1;
         }
     }
-    free(buf);
+    qemu_free(buf);
     return drv;
 }
 
@@ -154,7 +157,7 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int snapshot,
     bs->read_only = 0;
     bs->is_temporary = 0;
     bs->encrypted = 0;
-    
+
     if (snapshot) {
         BlockDriverState *bs1;
         int64_t total_size;
@@ -183,7 +186,7 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int snapshot,
         filename = tmp_filename;
         bs->is_temporary = 1;
     }
-    
+
     pstrcpy(bs->filename, sizeof(bs->filename), filename);
     if (!drv) {
         drv = find_image_format(filename);
@@ -653,4 +656,5 @@ void bdrv_init(void)
     bdrv_register(&bdrv_dmg);
     bdrv_register(&bdrv_bochs);
     bdrv_register(&bdrv_vpc);
+    bdrv_register(&bdrv_vvfat);
 }