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/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
* dir_tree.h
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#ifndef DIR_TREE_H
#define DIR_TREE_H
/**
* @enum SQFS_TREE_FILTER_FLAGS
*
* @brief Filter flags for @ref sqfs_dir_reader_get_full_hierarchy
*/
typedef enum {
/**
* @brief Omit device special files from the final tree.
*/
SQFS_TREE_NO_DEVICES = 0x01,
/**
* @brief Omit socket files from the final tree.
*/
SQFS_TREE_NO_SOCKETS = 0x02,
/**
* @brief Omit named pipes from the final tree.
*/
SQFS_TREE_NO_FIFO = 0x04,
/**
* @brief Omit symbolic links from the final tree.
*/
SQFS_TREE_NO_SLINKS = 0x08,
/**
* @brief Omit empty directories from the final tree.
*
* If a directory is not empty on-disk, but ends up empty after
* applying all the other filter rules, it is also omitted.
*/
SQFS_TREE_NO_EMPTY = 0x10,
/**
* @brief Do not recurse into sub directories.
*
* If the start node is a directory, the tree deserializer will still
* recurse into it, but it will not go beyond that.
*/
SQFS_TREE_NO_RECURSE = 0x20,
/**
* @brief Store the list of parent nodes all the way to the target node
*
* When traversing towards the selected node, also collect the chain
* of parent nodes with the subtree stored at the end.
*/
SQFS_TREE_STORE_PARENTS = 0x40,
SQFS_TREE_ALL_FLAGS = 0x7F,
} SQFS_TREE_FILTER_FLAGS;
/**
* @struct sqfs_tree_node_t
*
* @brief Encapsulates a node in the filesystem tree read by
* @ref sqfs_dir_reader_get_full_hierarchy.
*/
struct sqfs_tree_node_t {
/**
* @brief Pointer to parent, NULL for the root node
*/
sqfs_tree_node_t *parent;
/**
* @brief For directories, a linked list of children.
*/
sqfs_tree_node_t *children;
/**
* @brief Linked list next pointer for children list.
*/
sqfs_tree_node_t *next;
/**
* @brief Inode representing this element in the tree.
*/
sqfs_inode_generic_t *inode;
/**
* @brief Resolved 32 bit user ID from the inode
*/
sqfs_u32 uid;
/**
* @brief Resolved 32 bit group ID from the inode
*/
sqfs_u32 gid;
/**
* @brief null-terminated entry name.
*/
sqfs_u8 name[];
};
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Recursively destroy a tree of @ref sqfs_tree_node_t nodes
*
* This function can be used to clean up after
* @ref sqfs_dir_reader_get_full_hierarchy.
*
* @param root A pointer to the root node or NULL.
*/
SQFS_INTERNAL void sqfs_dir_tree_destroy(sqfs_tree_node_t *root);
/**
* @brief Recursively destroy a tree of @ref sqfs_tree_node_t nodes
*
* @memberof sqfs_tree_node_t
*
* This function can be used to assemble an absolute path from a tree
* node returned by @ref sqfs_dir_reader_get_full_hierarchy.
*
* The function recursively walks up the tree to assemble a path string. It
* returns "/" for the root node and assembles paths beginning with "/" for
* non-root nodes. The resulting path is slash separated, but (except for
* the root) never ends with a slash.
*
* While walking the node list, the function enforces various invariantes. It
* returns @ref SQFS_ERROR_LINK_LOOP if the list of parent pointers is cyclical,
* @ref SQFS_ERROR_CORRUPTED if any node has an empty name, or a name that
* contains '/' or equals ".." or ".". The function
* returns @ref SQFS_ERROR_ARG_INVALID if given NULL node or the root has a name
* set. Additionally, the function can return overflow or allocation failures
* while constructing the path.
*
* The returned string needs to be free'd with @ref sqfs_free.
*
* @param node A pointer to a tree node.
* @param out Returns a pointer to a string on success, set to NULL on failure.
*
* @return Zero on success, an @ref SQFS_ERROR value on failure.
*/
SQFS_INTERNAL int sqfs_tree_node_get_path(const sqfs_tree_node_t *node,
char **out);
/**
* @brief High level helper function for deserializing the entire file system
* hierarchy into an in-memory tree structure.
*
* @memberof sqfs_dir_reader_t
*
* This function internally navigates to a specified inode using
* @ref sqfs_dir_reader_find_by_path and starting from that recursively
* deserializes the entire hierarchy into a tree structure holding all inodes.
*
* @param rd A pointer to a directory reader.
* @param path A path to resolve into an inode. Forward or backward slashes can
* be used to separate path components. Resolving '.' or '..' is
* not supported. Can be set to NULL to get the root inode.
* @param flags A combination of @ref SQFS_TREE_FILTER_FLAGS flags.
* @param out Returns the top most tree node.
*
* @return Zero on success, an @ref SQFS_ERROR value on failure.
*/
SQFS_INTERNAL int sqfs_dir_reader_get_full_hierarchy(sqfs_dir_reader_t *rd,
const sqfs_id_table_t *idtbl,
const char *path,
sqfs_u32 flags,
sqfs_tree_node_t **out);
#ifdef __cplusplus
}
#endif
#endif /* DIR_TREE_H */
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