libntfs: add ntfs_index_root_get() which reads the index root of an attribute

ChangeLog

@@ -11,6 +11,8 @@ xx/xx/2006 - 1.13.1-WIP
 	  allocation entries.  (Szaka)
 	- libntfs: add ntfs_attr_readall() which reads the entire data 
 	  from an ntfs attribute.  (Szaka)
+	- libntfs: add ntfs_index_root_get() which reads the index root of 
+	  an attribute.  (Szaka)
 
 27/02/2006 - 1.13.0 - Lots and lots and lots of fixes and enhancements.
 

include/ntfs/index.h

@@ -101,6 +101,8 @@ extern int ntfs_index_add_filename(ntfs_inode *ni, FILE_NAME_ATTR *fn,
 		MFT_REF mref);
 extern int ntfs_index_rm(ntfs_index_context *ictx);
 
+extern INDEX_ROOT *ntfs_index_root_get(ntfs_inode *ni, ATTR_RECORD *attr);
+
 /**
  * ntfs_index_entry_mark_dirty - mark an index entry dirty
  * @ictx:	ntfs index context describing the index entry

libntfs/index.c

@@ -928,3 +928,49 @@ INDEX_ENTRY * ntfs_ie_remove_name(INDEX_ENTRY *ie)
 
 #endif /* NTFS_RICH */
 
+/**
+ * ntfs_index_root_get - read the index root of an attribute
+ * @ni:		open ntfs inode in which the ntfs attribute resides
+ * @attr:	attribute for which we want its index root 
+ *
+ * This function will read the related index root an ntfs attribute.
+ *
+ * On success a buffer is allocated with the content of the index root
+ * and which needs to be freed when it's not needed anymore.
+ *
+ * On error NULL is returned with errno set to the error code.
+ */
+INDEX_ROOT *ntfs_index_root_get(ntfs_inode *ni, ATTR_RECORD *attr)
+{
+	ntfs_attr_search_ctx *ctx;
+	ntfschar *name;
+	INDEX_ROOT *root = NULL;
+
+	name = (ntfschar *)((u8 *)attr + le16_to_cpu(attr->name_offset));
+
+	ctx = ntfs_attr_get_search_ctx(ni, NULL);
+	if (!ctx) {
+		ntfs_log_perror("ntfs_get_search_ctx failed");
+		return NULL;
+	}
+	
+	if (ntfs_attr_lookup(AT_INDEX_ROOT, name, attr->name_length, 0, 0, NULL,
+			     0, ctx)) {
+		ntfs_log_perror("ntfs_attr_lookup failed");
+		goto out;
+	}
+	
+	root = malloc(sizeof(INDEX_ROOT));
+	if (!root) {
+		ntfs_log_perror("malloc failed");
+		goto out;
+	}
+	
+	*root = *((INDEX_ROOT *)((u8 *)ctx->attr +
+				le16_to_cpu(ctx->attr->value_offset)));
+out:	
+	ntfs_attr_put_search_ctx(ctx);
+	return root;
+}
+
+

ntfsprogs/ntfsinfo.c

@@ -72,6 +72,7 @@
 #include "attrib.h"
 #include "layout.h"
 #include "inode.h"
+#include "index.h"
 #include "utils.h"
 #include "security.h"
 #include "mst.h"
@@ -1551,44 +1552,6 @@ static void ntfs_dump_attr_index_root(ATTR_RECORD *attr, ntfs_inode *ni)
 			ntfs_dump_index_entries(entry, type));
 }
 
-/**
- * get_index_root()
- *
- * determine size, type and the collation rule of INDX record
- */
-static INDEX_ROOT *get_index_root(ntfs_inode *ni, ATTR_RECORD *attr)
-{
-	ntfs_attr_search_ctx *ctx;
-	ntfschar *name;
-	INDEX_ROOT *root = NULL;
-
-	name = (ntfschar *)((u8 *)attr + le16_to_cpu(attr->name_offset));
-
-	ctx = ntfs_attr_get_search_ctx(ni, NULL);
-	if (!ctx) {
-		ntfs_log_perror("ntfs_get_search_ctx failed");
-		return NULL;
-	}
-	
-	if (ntfs_attr_lookup(AT_INDEX_ROOT, name, attr->name_length, 0, 0, NULL,
-			     0, ctx)) {
-		ntfs_log_perror("ntfs_attr_lookup failed");
-		goto out;
-	}
-	
-	root = malloc(sizeof(INDEX_ROOT));
-	if (!root) {
-		ntfs_log_perror("malloc failed");
-		goto out;
-	}
-	
-	*root = *((INDEX_ROOT *)((u8 *)ctx->attr +
-				le16_to_cpu(ctx->attr->value_offset)));
-out:	
-	ntfs_attr_put_search_ctx(ctx);
-	return root;
-}
-
 /**
  * ntfs_dump_attr_index_allocation()
  *
@@ -1608,7 +1571,7 @@ static void ntfs_dump_index_allocation(ATTR_RECORD *attr, ntfs_inode *ni)
 	u32 name_len;
 	s64 data_size;
 
-	index_root = get_index_root(ni, attr);
+	index_root = ntfs_index_root_get(ni, attr);
 	if (!index_root) {
 		ntfs_log_perror("Failed to read $INDEX_ROOT attribute");
 		return;