#include "wimlib/tagged_items.h"
#include "wimlib/util.h"
-#undef HAVE_XATTR_SUPPORT
+#undef HAVE_LINUX_XATTR_SUPPORT
#if defined(HAVE_SYS_XATTR_H) && \
defined(HAVE_LLISTXATTR) && defined(HAVE_LGETXATTR) && \
defined(HAVE_FSETXATTR) && defined(HAVE_LSETXATTR)
-# define HAVE_XATTR_SUPPORT 1
+# define HAVE_LINUX_XATTR_SUPPORT 1
#endif
+#define WIM_XATTR_NAME_MAX 255
+#define WIM_XATTR_SIZE_MAX 65535
+
+/*
+ * On-disk format of each extended attribute (xattr, or EA) entry in a metadata
+ * item tagged with TAG_XATTRS. This is the preferred xattr format, since it is
+ * also used by WIMGAPI and DISM starting in Windows 10 version 1607.
+ */
+struct wim_xattr_entry {
+
+ /* length of xattr value in bytes */
+ le16 value_len;
+
+ /* length of xattr name in bytes, excluding the null terminator */
+ u8 name_len;
+
+ /* flags: 0 or 0x80 (FILE_NEED_EA) */
+ u8 flags;
+
+ /* followed by the xattr name *with* a null terminator */
+ char name[0];
+
+ /* followed by the xattr value */
+ /* u8 value[0]; */
+
+ /* no padding at end! */
+} _packed_attribute;
+
+static inline size_t
+xattr_entry_size(const struct wim_xattr_entry *entry)
+{
+ STATIC_ASSERT(sizeof(*entry) == 4);
+
+ return sizeof(*entry) + entry->name_len + 1 +
+ le16_to_cpu(entry->value_len);
+}
+
+/* minimum is a 1-byte name (plus null terminator) and an empty value */
+#define XATTR_ENTRY_MIN_SIZE (sizeof(struct wim_xattr_entry) + 2)
+
+static inline struct wim_xattr_entry *
+xattr_entry_next(const struct wim_xattr_entry *entry)
+{
+ return (void *)entry + xattr_entry_size(entry);
+}
+
+static inline bool
+valid_xattr_entry(const struct wim_xattr_entry *entry, size_t avail)
+{
+ if (avail < sizeof(*entry))
+ return false;
+
+ return entry->name_len > 0 && entry->name_len <= WIM_XATTR_NAME_MAX &&
+ le16_to_cpu(entry->value_len) <= WIM_XATTR_SIZE_MAX &&
+ avail >= xattr_entry_size(entry) &&
+ memchr(entry->name, '\0', entry->name_len) == NULL &&
+ entry->name[entry->name_len] == '\0';
+}
+
/*
- * On-disk format of an entry in an extended attributes tagged item (wimlib
- * extension). An xattr item consists of a series of variable-length xattr
- * name/value pairs, each of which begins with this header.
- *
- * Currently this is only used for Linux-style xattrs, but in the future we may
- * use this for Windows-style xattrs too.
+ * On-disk format of each extended attribute entry in a metadata item tagged
+ * with TAG_WIMLIB_LINUX_XATTRS. This is a deprecated format which wimlib
+ * v1.11-v1.12 used to store extended attributes on Linux (predating the Windows
+ * xattr support in both WIMGAPI and wimlib). Now we use TAG_XATTRS for both
+ * Windows and Linux xattrs.
*/
-struct wimlib_xattr_entry {
+struct wimlib_xattr_entry_old {
- /* length of xattr name in bytes */
+ /* length of xattr name in bytes, excluding a null terminator */
le16 name_len;
/* reserved, must be 0 */
/* length of xattr value in bytes */
le32 value_len;
- /* followed by the xattr name with no terminating null */
+ /* followed by the xattr name *without* a null terminator */
char name[0];
- /* followed by the xattr value with no terminating null */
+ /* followed by the xattr value */
/* u8 value[0]; */
/* then zero-padded to a 4-byte boundary */
} _aligned_attribute(4);
static inline size_t
-xattr_entry_size(const struct wimlib_xattr_entry *entry)
+old_xattr_entry_size(const struct wimlib_xattr_entry_old *entry)
{
STATIC_ASSERT(sizeof(*entry) == 8);
le32_to_cpu(entry->value_len), 4);
}
-static inline struct wimlib_xattr_entry *
-xattr_entry_next(const struct wimlib_xattr_entry *entry)
+/* minimum is a 1-byte name and an empty value */
+#define OLD_XATTR_ENTRY_MIN_SIZE \
+ (ALIGN(sizeof(struct wimlib_xattr_entry_old) + 1, 4))
+
+static inline struct wimlib_xattr_entry_old *
+old_xattr_entry_next(const struct wimlib_xattr_entry_old *entry)
{
- return (void *)entry + xattr_entry_size(entry);
+ return (void *)entry + old_xattr_entry_size(entry);
}
-/* Currently we use the Linux limits when validating xattr names and values */
-#define XATTR_NAME_MAX 255
-#define XATTR_SIZE_MAX 65536
-
static inline bool
-valid_xattr_entry(const struct wimlib_xattr_entry *entry, size_t avail)
+old_valid_xattr_entry(const struct wimlib_xattr_entry_old *entry, size_t avail)
{
- if (avail < sizeof(*entry))
- return false;
-
- if (entry->name_len == 0 ||
- le16_to_cpu(entry->name_len) > XATTR_NAME_MAX)
- return false;
-
- if (entry->reserved != 0)
- return false;
+ u16 name_len;
- if (le32_to_cpu(entry->value_len) > XATTR_SIZE_MAX)
- return false;
-
- if (avail < xattr_entry_size(entry))
- return false;
-
- if (memchr(entry->name, '\0', le16_to_cpu(entry->name_len)))
+ if (avail < sizeof(*entry))
return false;
- return true;
+ name_len = le16_to_cpu(entry->name_len);
+ return name_len > 0 && name_len <= WIM_XATTR_NAME_MAX &&
+ le32_to_cpu(entry->value_len) <= WIM_XATTR_SIZE_MAX &&
+ avail >= old_xattr_entry_size(entry) &&
+ memchr(entry->name, '\0', name_len) == NULL;
}
-/* Is the xattr of the specified name security-related? */
+/* Is the xattr of the specified name security-related on Linux? */
static inline bool
-is_security_xattr(const char *name)
+is_linux_security_xattr(const char *name)
{
#define XATTR_SECURITY_PREFIX "security."
#define XATTR_SYSTEM_PREFIX "system."
}
static inline const void *
-inode_get_linux_xattrs(const struct wim_inode *inode, u32 *len_ret)
+inode_get_xattrs(const struct wim_inode *inode, u32 *len_ret)
+{
+ return inode_get_tagged_item(inode, TAG_XATTRS,
+ XATTR_ENTRY_MIN_SIZE, len_ret);
+}
+
+static inline const void *
+inode_get_xattrs_old(const struct wim_inode *inode, u32 *len_ret)
+{
+ return inode_get_tagged_item(inode, TAG_WIMLIB_LINUX_XATTRS,
+ OLD_XATTR_ENTRY_MIN_SIZE, len_ret);
+}
+
+static inline const void *
+inode_get_linux_xattrs(const struct wim_inode *inode, u32 *len_ret,
+ bool *is_old_format_ret)
{
- return inode_get_tagged_item(inode, TAG_WIMLIB_LINUX_XATTRS, 0,
- len_ret);
+ const void *entries;
+
+ entries = inode_get_xattrs(inode, len_ret);
+ if (entries) {
+ *is_old_format_ret = false;
+ return entries;
+ }
+ entries = inode_get_xattrs_old(inode, len_ret);
+ if (entries) {
+ *is_old_format_ret = true;
+ return entries;
+ }
+ return NULL;
}
static inline bool
-inode_has_linux_xattrs(const struct wim_inode *inode)
+inode_has_xattrs(const struct wim_inode *inode)
{
- return inode_get_linux_xattrs(inode, NULL) != NULL;
+ return inode_get_xattrs(inode, NULL) != NULL ||
+ inode_get_xattrs_old(inode, NULL) != NULL;
}
static inline bool
-inode_set_linux_xattrs(struct wim_inode *inode, const void *entries, u32 len)
+inode_set_xattrs(struct wim_inode *inode, const void *entries, u32 len)
{
- return inode_set_tagged_item(inode, TAG_WIMLIB_LINUX_XATTRS,
- entries, len);
+ return inode_set_tagged_item(inode, TAG_XATTRS, entries, len);
}
#endif /* _WIMLIB_XATTR_H */
git://wimlib.net / wimlib / blobdiff