diff options
Diffstat (limited to 'lib/common/src/read_tree.c')
| -rw-r--r-- | lib/common/src/read_tree.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/lib/common/src/read_tree.c b/lib/common/src/read_tree.c new file mode 100644 index 0000000..5d089e5 --- /dev/null +++ b/lib/common/src/read_tree.c @@ -0,0 +1,273 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +/* + * read_tree.c + * + * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at> + */ +#include "util/util.h" +#include "common.h" + +#include <string.h> +#include <stdlib.h> + +static int should_skip(int type, unsigned int flags) +{ + switch (type) { + case SQFS_INODE_BDEV: + case SQFS_INODE_CDEV: + case SQFS_INODE_EXT_CDEV: + case SQFS_INODE_EXT_BDEV: + return (flags & SQFS_TREE_NO_DEVICES); + case SQFS_INODE_SLINK: + case SQFS_INODE_EXT_SLINK: + return (flags & SQFS_TREE_NO_SLINKS); + case SQFS_INODE_SOCKET: + case SQFS_INODE_EXT_SOCKET: + return(flags & SQFS_TREE_NO_SOCKETS); + case SQFS_INODE_FIFO: + case SQFS_INODE_EXT_FIFO: + return (flags & SQFS_TREE_NO_FIFO); + default: + break; + } + + return 0; +} + +static bool would_be_own_parent(sqfs_tree_node_t *parent, sqfs_tree_node_t *n) +{ + sqfs_u32 inum = n->inode->base.inode_number; + + while (parent != NULL) { + if (parent->inode->base.inode_number == inum) + return true; + + parent = parent->parent; + } + + return false; +} + +static sqfs_tree_node_t *create_node(sqfs_inode_generic_t *inode, + const char *name) +{ + sqfs_tree_node_t *n; + + n = alloc_flex(sizeof(*n), 1, strlen(name) + 1); + if (n == NULL) + return NULL; + + n->inode = inode; + strcpy((char *)n->name, name); + return n; +} + +static int fill_dir(sqfs_dir_reader_t *dr, sqfs_tree_node_t *root, + unsigned int flags) +{ + sqfs_tree_node_t *n, *prev, **tail; + sqfs_inode_generic_t *inode; + sqfs_dir_node_t *ent; + int err; + + tail = &root->children; + + for (;;) { + err = sqfs_dir_reader_read(dr, &ent); + if (err > 0) + break; + if (err < 0) + return err; + + if (should_skip(ent->type, flags)) { + free(ent); + continue; + } + + err = sqfs_dir_reader_get_inode(dr, &inode); + if (err) { + free(ent); + return err; + } + + n = create_node(inode, (const char *)ent->name); + free(ent); + + if (n == NULL) { + free(inode); + return SQFS_ERROR_ALLOC; + } + + if (would_be_own_parent(root, n)) { + free(n); + free(inode); + return SQFS_ERROR_LINK_LOOP; + } + + *tail = n; + tail = &n->next; + n->parent = root; + } + + n = root->children; + prev = NULL; + + while (n != NULL) { + if (n->inode->base.type == SQFS_INODE_DIR || + n->inode->base.type == SQFS_INODE_EXT_DIR) { + if (!(flags & SQFS_TREE_NO_RECURSE)) { + err = sqfs_dir_reader_open_dir(dr, n->inode, + SQFS_DIR_OPEN_NO_DOT_ENTRIES); + if (err) + return err; + + err = fill_dir(dr, n, flags); + if (err) + return err; + } + + if (n->children == NULL && + (flags & SQFS_TREE_NO_EMPTY)) { + free(n->inode); + if (prev == NULL) { + root->children = root->children->next; + free(n); + n = root->children; + } else { + prev->next = n->next; + free(n); + n = prev->next; + } + continue; + } + } + + prev = n; + n = n->next; + } + + return 0; +} + +static int resolve_ids(sqfs_tree_node_t *root, const sqfs_id_table_t *idtbl) +{ + sqfs_tree_node_t *it; + int err; + + for (it = root->children; it != NULL; it = it->next) + resolve_ids(it, idtbl); + + err = sqfs_id_table_index_to_id(idtbl, root->inode->base.uid_idx, + &root->uid); + if (err) + return err; + + return sqfs_id_table_index_to_id(idtbl, root->inode->base.gid_idx, + &root->gid); +} + +int sqfs_dir_reader_get_full_hierarchy(sqfs_dir_reader_t *rd, + const sqfs_id_table_t *idtbl, + const char *path, unsigned int flags, + sqfs_tree_node_t **out) +{ + sqfs_tree_node_t *root, *tail, *new; + sqfs_inode_generic_t *inode; + sqfs_dir_node_t *ent; + const char *ptr; + int ret; + + if (flags & ~SQFS_TREE_ALL_FLAGS) + return SQFS_ERROR_UNSUPPORTED; + + ret = sqfs_dir_reader_get_root_inode(rd, &inode); + if (ret) + return ret; + + root = tail = create_node(inode, ""); + if (root == NULL) { + free(inode); + return SQFS_ERROR_ALLOC; + } + inode = NULL; + + while (path != NULL && *path != '\0') { + if (*path == '/') { + while (*path == '/') + ++path; + continue; + } + + ret = sqfs_dir_reader_open_dir(rd, tail->inode, + SQFS_DIR_OPEN_NO_DOT_ENTRIES); + if (ret) + goto fail; + + ptr = strchrnul(path, '/'); + + for (;;) { + ret = sqfs_dir_reader_read(rd, &ent); + if (ret < 0) + goto fail; + if (ret > 0) { + ret = SQFS_ERROR_NO_ENTRY; + goto fail; + } + + ret = strncmp((const char *)ent->name, + path, ptr - path); + if (ret == 0 && ent->name[ptr - path] == '\0') + break; + free(ent); + } + + ret = sqfs_dir_reader_get_inode(rd, &inode); + if (ret) { + free(ent); + goto fail; + } + + new = create_node(inode, (const char *)ent->name); + free(ent); + + if (new == NULL) { + free(inode); + ret = SQFS_ERROR_ALLOC; + goto fail; + } + + inode = NULL; + path = ptr; + + if (flags & SQFS_TREE_STORE_PARENTS) { + tail->children = new; + new->parent = tail; + tail = new; + } else { + sqfs_dir_tree_destroy(root); + root = tail = new; + } + } + + if (tail->inode->base.type == SQFS_INODE_DIR || + tail->inode->base.type == SQFS_INODE_EXT_DIR) { + ret = sqfs_dir_reader_open_dir(rd, tail->inode, + SQFS_DIR_OPEN_NO_DOT_ENTRIES); + if (ret) + goto fail; + + ret = fill_dir(rd, tail, flags); + if (ret) + goto fail; + } + + ret = resolve_ids(root, idtbl); + if (ret) + goto fail; + + *out = root; + return 0; +fail: + sqfs_dir_tree_destroy(root); + return ret; +} |