Add support for '.' and '..' entries in sqfs_dir_reader_t

Two flags are added to the dir reader API, one for the create function
that the dir reader should report those entries and one to the open
function to suppress that if it was enabled.

To implement the feature, a mapping of visited directory inodes is
maintained internally, that mapps inode numbers to inode references.

When opening a directory, state is maintained to generate the fake
entries for '.' and '..'. Since all the other functions are based on
the open/read/rewind API, no alterations need to be made. The tree
scan function is modified, to use the suppress flag, so it does not
accidentally catch those entries.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 31 insertions, 0 deletions

diff --git a/lib/sqfs/dir_reader/internal.h b/lib/sqfs/dir_reader/internal.h
index ff162ff..cd20b69 100644
--- a/lib/sqfs/dir_reader/internal.h
+++ b/lib/sqfs/dir_reader/internal.h
@@ -17,11 +17,20 @@
 #include "sqfs/inode.h"
 #include "sqfs/error.h"
 #include "sqfs/dir.h"
+#include "rbtree.h"
 #include "util.h"
 
 #include <string.h>
 #include <stdlib.h>
 
+enum {
+	DIR_STATE_NONE = 0,
+	DIR_STATE_OPENED = 1,
+	DIR_STATE_DOT = 2,
+	DIR_STATE_DOT_DOT = 3,
+	DIR_STATE_ENTRIES = 4,
+};
+
 struct sqfs_dir_reader_t {
 	sqfs_object_t base;
 
@@ -37,6 +46,28 @@ struct sqfs_dir_reader_t {
 	size_t start_size;
 	sqfs_u16 dir_offset;
 	sqfs_u16 inode_offset;
+
+	sqfs_u32 flags;
+
+	int start_state;
+	int state;
+	sqfs_u64 parent_ref;
+	sqfs_u64 cur_ref;
+	rbtree_t dcache;
 };
 
+SQFS_INTERNAL int sqfs_dir_reader_dcache_init(sqfs_dir_reader_t *rd,
+					      sqfs_u32 flags);
+
+SQFS_INTERNAL int sqfs_dir_reader_dcache_init_copy(sqfs_dir_reader_t *copy,
+						   const sqfs_dir_reader_t *rd);
+
+SQFS_INTERNAL int sqfs_dir_reader_dcache_add(sqfs_dir_reader_t *rd,
+					     sqfs_u32 inode, sqfs_u64 ref);
+
+SQFS_INTERNAL int sqfs_dir_reader_dcache_find(sqfs_dir_reader_t *rd,
+					      sqfs_u32 inode, sqfs_u64 *ref);
+
+SQFS_INTERNAL void sqfs_dir_reader_dcache_cleanup(sqfs_dir_reader_t *rd);
+
 #endif /* DIR_READER_INTERNAL_H */