libsqfs: Add the path lookup function back to the dir reader

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

3 files changed, 99 insertions, 40 deletions

diff --git a/extras/browse.c b/extras/browse.c
index 00e5dbe..70537f2 100644
--- a/extras/browse.c
+++ b/extras/browse.c
@@ -34,55 +34,22 @@ static char *prompt;
 
 static int resolve_ref(const char *path, sqfs_u64 *out)
 {
-	sqfs_dir_reader_state_t state;
 	sqfs_inode_generic_t *inode;
-	sqfs_dir_node_t *ent;
-	const char *end;
 	sqfs_u64 ref;
-	size_t len;
 	int ret;
 
-	ref = *path == '/' ? super.root_inode_ref : working_dir;
-
-	while (path != NULL && *path != '\0') {
-		if (*path == '/') {
-			while (*path == '/')
-				++path;
-			continue;
-		}
-
-		end = strchr(path, '/');
-		len = (end == NULL) ? strlen(path) : (size_t)(end - path);
-
-		ret = sqfs_dir_reader_get_inode(dr, ref, &inode);
-		if (ret != 0)
-			return ret;
+	ref = (*path == '/') ? super.root_inode_ref : working_dir;
 
-		ret = sqfs_dir_reader_open_dir(dr, inode, &state, 0);
+	ret = sqfs_dir_reader_get_inode(dr, ref, &inode);
+	if (ret == 0) {
+		ret = sqfs_dir_reader_resolve_path(dr, path, inode, &ref);
 		sqfs_free(inode);
 
-		if (ret != 0)
-			return ret;
-
-		do {
-			ret = sqfs_dir_reader_read(dr, &state, &ent);
-			if (ret < 0)
-				return ret;
-			if (ret > 0)
-				return 1;
-
-			ret = strncmp((const char *)ent->name, path, len);
-			free(ent);
-			if (ret == 0 && ent->name[len] != '\0')
-				return 1;
-		} while (ret != 0);
-
-		ref = state.ent_ref;
-		path = end;
+		if (ret == 0)
+			*out = ref;
 	}
 
-	*out = ref;
-	return 0;
+	return ret;
 }
 
 static char *add_prefix(const char *pfx, size_t pfxlen, char *path)
diff --git a/include/sqfs/dir_reader.h b/include/sqfs/dir_reader.h
index ceac22b..50d3636 100644
--- a/include/sqfs/dir_reader.h
+++ b/include/sqfs/dir_reader.h
@@ -273,6 +273,23 @@ SQFS_API int sqfs_dir_reader_get_root_inode(sqfs_dir_reader_t *rd,
 SQFS_API int sqfs_dir_reader_resolve_inum(sqfs_dir_reader_t *rd,
 					  sqfs_u32 inode, sqfs_u64 *ref);
 
+/**
+ * @brief Try to resole a path into an inode reference
+ *
+ * @memberof sqfs_dir_reader_t
+ *
+ * @param rd A pointer to a directory reader.
+ * @param path A path to resolve, NULL is interpreted as empty path.
+ * @param root A directory inode to start from or NULL for the filesystem root.
+ * @param out Retrns an inode reference on success.
+ *
+ * @return Zero on success, a negative @ref SQFS_ERROR number on failure.
+ */
+SQFS_API int sqfs_dir_reader_resolve_path(sqfs_dir_reader_t *rd,
+					  const char *path,
+					  const sqfs_inode_generic_t *root,
+					  sqfs_u64 *out);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/sqfs/src/dir_reader.c b/lib/sqfs/src/dir_reader.c
index 6920a7d..29d7c33 100644
--- a/lib/sqfs/src/dir_reader.c
+++ b/lib/sqfs/src/dir_reader.c
@@ -296,3 +296,78 @@ int sqfs_dir_reader_resolve_inum(sqfs_dir_reader_t *rd,
 	*ref = *((sqfs_u64 *)rbtree_node_value(node));
 	return 0;
 }
+
+int sqfs_dir_reader_resolve_path(sqfs_dir_reader_t *rd, const char *path,
+				 const sqfs_inode_generic_t *root,
+				 sqfs_u64 *out)
+{
+	bool is_first = true;
+
+	while (path != NULL && *path != '\0') {
+		sqfs_dir_reader_state_t state;
+		int ret;
+
+		if (*path == '/') {
+			while (*path == '/')
+				++path;
+			continue;
+		}
+
+		if (is_first && root != NULL) {
+			ret = sqfs_dir_reader_open_dir(rd, root, &state, 0);
+		} else {
+			sqfs_inode_generic_t *inode = NULL;
+
+			if (is_first)
+				*out = rd->super.root_inode_ref;
+
+			ret = sqfs_dir_reader_get_inode(rd, *out, &inode);
+			if (ret == 0) {
+				ret = sqfs_dir_reader_open_dir(rd, inode,
+							       &state, 0);
+			}
+
+			sqfs_free(inode);
+		}
+
+		is_first = false;
+		if (ret != 0)
+			return ret;
+
+		for (;;) {
+			sqfs_dir_node_t *ent;
+			size_t len;
+
+			ret = sqfs_dir_reader_read(rd, &state, &ent);
+			if (ret < 0)
+				return ret;
+			if (ret > 0)
+				return SQFS_ERROR_NO_ENTRY;
+
+			len = ent->size + 1;
+			ret = strncmp((const char *)ent->name, path, len);
+			sqfs_free(ent);
+
+			if (ret == 0 &&
+			    (path[len] == '/' || path[len] == '\0')) {
+				path += len;
+				break;
+			}
+		}
+
+		*out = state.ent_ref;
+	}
+
+	if (is_first) {
+		if (root == NULL) {
+			*out = rd->super.root_inode_ref;
+			return 0;
+		}
+
+		return sqfs_dir_reader_resolve_inum(rd,
+						    root->base.inode_number,
+						    out);
+	}
+
+	return 0;
+}