X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=include%2Fwimlib%2Freparse.h;h=dce19a22130087ec1cc9475a88b060aab513dbdb;hp=43adbd5c87406913f300131b1c03feadebf0fbfa;hb=37d9c3935130128901f6eee8d7531d8ae4b1bca6;hpb=3de1ec66f778edda19865482d685bc6f4e17faf7

diff --git a/include/wimlib/reparse.h b/include/wimlib/reparse.h
index 43adbd5c..dce19a22 100644
--- 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_OFFSET ((unsigned)offsetof(struct reparse_buffer_disk, rpdata))
 
 #define REPARSE_DATA_MAX_SIZE (REPARSE_POINT_MAX_SIZE - REPARSE_DATA_OFFSET)
 
+static _unused_attribute 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,