libntfs: add ntfs_attr_readall() which reads the entire data from an attribute

ChangeLog

@@ -7,8 +7,10 @@ xx/xx/2006 - 1.13.1-WIP
 	  in $Bitmap (useful to find potentially corrupted files). (Szaka)
 	- mkntfs: set the physical drive and the extended boot signature to
 	  0x80 in the Extended BPB which are needed to boot from disk. (Szaka)
-	- ntfsinfo: fix two freed memory usage when dumping $SDS and index
+	- ntfsinfo: fix two freed memory usages when dumping $SDS and index
 	  allocation entries.  (Szaka)
+	- libntfs: add ntfs_attr_readall() which reads the entire data 
+	  from an ntfs attribute.  (Szaka)
 
 27/02/2006 - 1.13.0 - Lots and lots and lots of fixes and enhancements.
 

include/ntfs/attrib.h

@@ -270,6 +270,9 @@ extern s64 ntfs_attr_pread(ntfs_attr *na, const s64 pos, s64 count,
 extern s64 ntfs_attr_pwrite(ntfs_attr *na, const s64 pos, s64 count,
 		const void *b);
 
+extern void *ntfs_attr_readall(ntfs_inode *ni, const ATTR_TYPES type,
+			       ntfschar *name, u32 name_len, s64 *data_size);
+
 extern s64 ntfs_attr_mst_pread(ntfs_attr *na, const s64 pos,
 		const s64 bk_cnt, const u32 bk_size, void *dst);
 extern s64 ntfs_attr_mst_pwrite(ntfs_attr *na, const s64 pos,

libntfs/attrib.c

@@ -4992,3 +4992,54 @@ int ntfs_attr_truncate(ntfs_attr *na, const s64 newsize)
 		ntfs_inode_update_time(na->ni);
 	return ret;
 }
+	
+/**
+ * ntfs_attr_readall - read the entire data from an ntfs attribute
+ * @ni:		open ntfs inode in which the ntfs attribute resides
+ * @type:	attribute type
+ * @name:	attribute name in little endian Unicode or AT_UNNAMED or NULL
+ * @name_len:	length of attribute @name in Unicode characters (if @name given)
+ * @data_size:	if non-NULL then store here the data size 
+ *
+ * This function will read the entire content of an ntfs attribute.
+ * If @name is AT_UNNAMED then look specifically for an unnamed attribute.
+ * If @name is NULL then the attribute could be either named or not. 
+ * In both those cases @name_len is not used at all.
+ *
+ * On success a buffer is allocated with the content of the attribute 
+ * and which needs to be freed when it's not needed anymore. If the
+ * @data_size parameter is non-NULL then the data size is set there.
+ *
+ * On error NULL is returned with errno set to the error code.
+ */
+void *ntfs_attr_readall(ntfs_inode *ni, const ATTR_TYPES type,
+			ntfschar *name, u32 name_len, s64 *data_size)
+{
+	ntfs_attr *na;
+	void *data, *ret = NULL;
+	s64 size;
+	
+	na = ntfs_attr_open(ni, type, name, name_len);
+	if (!na) {
+		ntfs_log_perror("ntfs_attr_open failed");
+		return NULL;
+	}
+	data = malloc(na->data_size);
+	if (!data) {
+		ntfs_log_perror("malloc failed");
+		goto out;
+	}
+	size = ntfs_attr_pread(na, 0, na->data_size, data);
+	if (size != na->data_size) {
+		ntfs_log_perror("ntfs_attr_pread failed");
+		free(data);
+		goto out;
+	}
+	ret = data;
+	if (data_size)
+		*data_size = size;
+out:
+	ntfs_attr_close(na);
+	return ret;
+}
+

ntfsprogs/ntfsinfo.c

@@ -1069,37 +1069,6 @@ static void ntfs_dump_sds_entry(SECURITY_DESCRIPTOR_HEADER *sds)
 	
 	ntfs_dump_security_descriptor(sd, "\t");
 }
-	
-static void *ntfs_attr_readall(ntfs_inode *ni, const ATTR_TYPES type, 
-			       ntfschar *name, u32 name_len, s64 *data_size)
-{
-	ntfs_attr *na;
-	void *data, *ret = NULL;
-	s64 size;
-	
-	na = ntfs_attr_open(ni, type, name, name_len);
-	if (!na) {
-		ntfs_log_perror("ntfs_attr_open failed");
-		return NULL;
-	}
-	data = malloc(na->data_size);
-	if (!data) {
-		ntfs_log_perror("malloc failed");
-		goto out;
-	}
-	size = ntfs_attr_pread(na, 0, na->data_size, data);
-	if (size != na->data_size) {
-		ntfs_log_perror("ntfs_attr_pread failed");
-		free(data);
-		goto out;
-	}
-	ret = data;
-	if (data_size)
-		*data_size = size;
-out:
-	ntfs_attr_close(na);
-	return ret;
-}
 
 static void ntfs_dump_sds(ATTR_RECORD *attr, ntfs_inode *ni)
 {
@@ -1125,8 +1094,10 @@ static void ntfs_dump_sds(ATTR_RECORD *attr, ntfs_inode *ni)
 		return;
 	
 	sd = sds = ntfs_attr_readall(ni, AT_DATA, name, name_len, &data_size);
-	if (!sd)
+	if (!sd) {
+		ntfs_log_perror("ntfs_attr_readall failed");
 		return;
+	}
 	/*
 	 * FIXME: The right way is based on the indexes, so we couldn't
 	 * miss real entries. For now, dump until it makes sense.
@@ -1650,12 +1621,15 @@ static void ntfs_dump_index_allocation(ATTR_RECORD *attr, ntfs_inode *ni)
 	name_len = attr->name_length;
 	
 	byte = bitmap = ntfs_attr_readall(ni, AT_BITMAP, name, name_len, NULL);
-	if (!byte)
+	if (!byte) {
+		ntfs_log_perror("ntfs_attr_readall failed");
 		return;
+	}
 
 	tmp_alloc = allocation = ntfs_attr_readall(ni, AT_INDEX_ALLOCATION, 
 						   name, name_len, &data_size);
 	if (!tmp_alloc) {
+		ntfs_log_perror("ntfs_attr_readall failed");
 		free(bitmap);
 		return;
 	}