system compression: try to attach WOF if compression fails

[wimlib] / include / wimlib / reparse.h

diff --git a/include/wimlib/reparse.h b/include/wimlib/reparse.h
index 43adbd5c87406913f300131b1c03feadebf0fbfa..7627ad41cca4ce7aff1db00f9781aebade2ca75f 100644 (file)
--- a/include/wimlib/reparse.h
+++ b/include/wimlib/reparse.h
@@ -1,17 +1,22 @@
 #ifndef _WIMLIB_REPARSE_H
 #define _WIMLIB_REPARSE_H
 
-#include <sys/types.h>
-
+#include "wimlib/inode.h" /* for reparse tag definitions */
 #include "wimlib/types.h"
 
-struct wim_inode;
-struct blob_table;
 struct blob_descriptor;
+struct blob_table;
 
-#define REPARSE_POINT_MAX_SIZE (16 * 1024)
+/* Windows enforces this limit on the size of a reparse point buffer.  */
+#define REPARSE_POINT_MAX_SIZE 16384
 
-/* On-disk format of reparse point buffer  */
+/*
+ * On-disk format of a reparse point buffer.  See:
+ *     https://msdn.microsoft.com/en-us/library/dd541671.aspx
+ *
+ * Note: we are not using _packed_attribute for this structure, so only cast to
+ * this if properly aligned!
+ */
 struct reparse_buffer_disk {
        le32 rptag;
        le16 rpdatalen;
@@ -24,72 +29,80 @@ struct reparse_buffer_disk {
                        le16 substitute_name_nbytes;
                        le16 print_name_offset;
                        le16 print_name_nbytes;
-                       le32 rpflags;
-                       u8 data[REPARSE_POINT_MAX_SIZE - 20];
-               } _packed_attribute symlink;
 
-               struct {
-                       le16 substitute_name_offset;
-                       le16 substitute_name_nbytes;
-                       le16 print_name_offset;
-                       le16 print_name_nbytes;
-                       u8 data[REPARSE_POINT_MAX_SIZE - 16];
-               } _packed_attribute junction;
+                       union {
+                               struct {
+                                       u8 data[REPARSE_POINT_MAX_SIZE - 16];
+                               } junction;
+
+                               struct {
+                                       le32 flags;
+                       #define SYMBOLIC_LINK_RELATIVE 0x00000001
+                                       u8 data[REPARSE_POINT_MAX_SIZE - 20];
+                               } symlink;
+                       };
+               } link;
        };
-} _packed_attribute;
+};
 
 #define REPARSE_DATA_OFFSET (offsetof(struct reparse_buffer_disk, rpdata))
 
 #define REPARSE_DATA_MAX_SIZE (REPARSE_POINT_MAX_SIZE - REPARSE_DATA_OFFSET)
 
+static inline void
+check_reparse_buffer_disk(void)
+{
+       STATIC_ASSERT(offsetof(struct reparse_buffer_disk, rpdata) == 8);
+       STATIC_ASSERT(offsetof(struct reparse_buffer_disk, link.junction.data) == 16);
+       STATIC_ASSERT(offsetof(struct reparse_buffer_disk, link.symlink.data) == 20);
+       STATIC_ASSERT(sizeof(struct reparse_buffer_disk) == REPARSE_POINT_MAX_SIZE);
+}
 
-/* Structured format for symbolic link, junction point, or mount point reparse
- * data. */
-struct reparse_data {
-       /* Reparse point tag (see WIM_IO_REPARSE_TAG_* values) */
-       u32 rptag;
-
-       /* Length of reparse data, not including the 8-byte header (ReparseTag,
-        * ReparseDataLength, ReparseReserved) */
-       u16 rpdatalen;
+/* Wrapper around a symbolic link or junction reparse point
+ * (WIM_IO_REPARSE_TAG_SYMLINK or WIM_IO_REPARSE_TAG_MOUNT_POINT)  */
+struct link_reparse_point {
 
-       /* ReparseReserved */
+       u32 rptag;
        u16 rpreserved;
 
-       /* Flags (only for WIM_IO_REPARSE_TAG_SYMLINK reparse points).
-        * SYMBOLIC_LINK_RELATIVE means this is a relative symbolic link;
-        * otherwise should be set to 0. */
-#define SYMBOLIC_LINK_RELATIVE 0x00000001
-       u32 rpflags;
+       /* Flags, valid for symbolic links only  */
+       u32 symlink_flags;
 
-       /* Pointer to the substitute name of the link (UTF-16LE). */
+       /* Pointers to the substitute name and print name of the link,
+        * potentially not null terminated  */
        utf16lechar *substitute_name;
-
-       /* Pointer to the print name of the link (UTF-16LE). */
        utf16lechar *print_name;
 
-       /* Number of bytes of the substitute name, not including null terminator
-        * if present */
-       u16 substitute_name_nbytes;
-
-       /* Number of bytes of the print name, not including null terminator if
-        * present */
-       u16 print_name_nbytes;
+       /* Lengths of the substitute and print names in bytes, not including
+        * their null terminators if present  */
+       size_t substitute_name_nbytes;
+       size_t print_name_nbytes;
 };
 
+static inline bool
+link_is_relative_symlink(const struct link_reparse_point *link)
+{
+       return link->rptag == WIM_IO_REPARSE_TAG_SYMLINK &&
+              (link->symlink_flags & SYMBOLIC_LINK_RELATIVE);
+}
+
+extern void
+complete_reparse_point(struct reparse_buffer_disk *rpbuf,
+                      const struct wim_inode *inode, u16 blob_size);
+
 extern int
-parse_reparse_data(const u8 * restrict rpbuf, u16 rpbuflen,
-                  struct reparse_data * restrict rpdata);
+parse_link_reparse_point(const struct reparse_buffer_disk *rpbuf, u16 rpbuflen,
+                        struct link_reparse_point *link);
 
 extern int
-make_reparse_buffer(const struct reparse_data * restrict rpdata,
-                   u8 * restrict rpbuf,
-                   u16 * restrict rpbuflen_ret);
+make_link_reparse_point(const struct link_reparse_point *link,
+                       struct reparse_buffer_disk *rpbuf, u16 *rpbuflen_ret);
 
 #ifndef __WIN32__
-ssize_t
-wim_inode_readlink(const struct wim_inode * restrict inode, char * restrict buf,
-                  size_t buf_len, struct blob_descriptor *blob);
+extern int
+wim_inode_readlink(const struct wim_inode *inode, char *buf, size_t bufsize,
+                  const struct blob_descriptor *blob,
+                  const char *altroot, size_t altroot_len);
 
 extern int
 wim_inode_set_symlink(struct wim_inode *inode, const char *target,