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-rw-r--r--lib/sqfshelper/deserialize_fstree.c304
1 files changed, 304 insertions, 0 deletions
diff --git a/lib/sqfshelper/deserialize_fstree.c b/lib/sqfshelper/deserialize_fstree.c
new file mode 100644
index 0000000..11670e1
--- /dev/null
+++ b/lib/sqfshelper/deserialize_fstree.c
@@ -0,0 +1,304 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * deserialize_fstree.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include "xattr_reader.h"
+#include "meta_reader.h"
+#include "highlevel.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+static int should_skip(int type, int flags)
+{
+ switch (type) {
+ case SQFS_INODE_BDEV:
+ case SQFS_INODE_CDEV:
+ case SQFS_INODE_EXT_CDEV:
+ case SQFS_INODE_EXT_BDEV:
+ return (flags & RDTREE_NO_DEVICES);
+ case SQFS_INODE_SLINK:
+ case SQFS_INODE_EXT_SLINK:
+ return (flags & RDTREE_NO_SLINKS);
+ case SQFS_INODE_SOCKET:
+ case SQFS_INODE_EXT_SOCKET:
+ return(flags & RDTREE_NO_SOCKETS);
+ case SQFS_INODE_FIFO:
+ case SQFS_INODE_EXT_FIFO:
+ return (flags & RDTREE_NO_FIFO);
+ }
+ return 0;
+}
+
+static int restore_xattr(xattr_reader_t *xr, fstree_t *fs, tree_node_t *node,
+ sqfs_inode_generic_t *inode)
+{
+ uint32_t idx;
+
+ switch (inode->base.type) {
+ case SQFS_INODE_EXT_DIR:
+ idx = inode->data.dir_ext.xattr_idx;
+ break;
+ case SQFS_INODE_EXT_FILE:
+ idx = inode->data.file_ext.xattr_idx;
+ break;
+ case SQFS_INODE_EXT_SLINK:
+ idx = inode->data.slink_ext.xattr_idx;
+ break;
+ case SQFS_INODE_EXT_BDEV:
+ case SQFS_INODE_EXT_CDEV:
+ idx = inode->data.dev_ext.xattr_idx;
+ break;
+ case SQFS_INODE_EXT_FIFO:
+ case SQFS_INODE_EXT_SOCKET:
+ idx = inode->data.ipc_ext.xattr_idx;
+ break;
+ default:
+ return 0;
+ }
+
+ return xattr_reader_restore_node(xr, fs, node, idx);
+}
+
+static bool node_would_be_own_parent(tree_node_t *root, tree_node_t *n)
+{
+ while (root != NULL) {
+ if (root->inode_num == n->inode_num)
+ return true;
+
+ root = root->parent;
+ }
+
+ return false;
+}
+
+static int fill_dir(meta_reader_t *ir, meta_reader_t *dr, tree_node_t *root,
+ sqfs_super_t *super, id_table_t *idtbl, fstree_t *fs,
+ xattr_reader_t *xr, int flags)
+{
+ sqfs_inode_generic_t *inode;
+ sqfs_dir_header_t hdr;
+ sqfs_dir_entry_t *ent;
+ tree_node_t *n, *prev;
+ uint64_t block_start;
+ size_t size, diff;
+ uint32_t i;
+
+ size = root->data.dir->size;
+ if (size <= sizeof(hdr))
+ return 0;
+
+ block_start = root->data.dir->start_block;
+ block_start += super->directory_table_start;
+
+ if (meta_reader_seek(dr, block_start, root->data.dir->block_offset))
+ return -1;
+
+ while (size > sizeof(hdr)) {
+ if (meta_reader_read_dir_header(dr, &hdr))
+ return -1;
+
+ size -= sizeof(hdr);
+
+ for (i = 0; i <= hdr.count && size > sizeof(*ent); ++i) {
+ ent = meta_reader_read_dir_ent(dr);
+ if (ent == NULL)
+ return -1;
+
+ diff = sizeof(*ent) + strlen((char *)ent->name);
+ if (diff > size) {
+ free(ent);
+ break;
+ }
+ size -= diff;
+
+ if (should_skip(ent->type, flags)) {
+ free(ent);
+ continue;
+ }
+
+ inode = meta_reader_read_inode(ir, super,
+ hdr.start_block,
+ ent->offset);
+ if (inode == NULL) {
+ free(ent);
+ return -1;
+ }
+
+ n = tree_node_from_inode(inode, idtbl,
+ (char *)ent->name,
+ super->block_size);
+
+ if (n == NULL) {
+ free(ent);
+ free(inode);
+ return -1;
+ }
+
+ if (node_would_be_own_parent(root, n)) {
+ fputs("WARNING: Found a directory that "
+ "contains itself, skipping loop back "
+ "reference!\n", stderr);
+ free(n);
+ free(ent);
+ free(inode);
+ continue;
+ }
+
+ if (flags & RDTREE_READ_XATTR) {
+ if (restore_xattr(xr, fs, n, inode)) {
+ free(n);
+ free(ent);
+ free(inode);
+ return -1;
+ }
+ }
+
+ free(ent);
+ free(inode);
+
+ n->parent = root;
+ n->next = root->data.dir->children;
+ root->data.dir->children = n;
+ }
+ }
+
+ n = root->data.dir->children;
+ prev = NULL;
+
+ while (n != NULL) {
+ if (S_ISDIR(n->mode)) {
+ if (fill_dir(ir, dr, n, super, idtbl, fs, xr, flags))
+ return -1;
+
+ if (n->data.dir->children == NULL &&
+ (flags & RDTREE_NO_EMPTY)) {
+ if (prev == NULL) {
+ root->data.dir->children = n->next;
+ free(n);
+ n = root->data.dir->children;
+ } else {
+ prev->next = n->next;
+ free(n);
+ n = prev->next;
+ }
+ continue;
+ }
+ }
+
+ prev = n;
+ n = n->next;
+ }
+
+ return 0;
+}
+
+int deserialize_fstree(fstree_t *out, sqfs_super_t *super, compressor_t *cmp,
+ int fd, int flags)
+{
+ uint64_t block_start, limit;
+ sqfs_inode_generic_t *root;
+ meta_reader_t *ir, *dr;
+ xattr_reader_t *xr;
+ id_table_t idtbl;
+ int status = -1;
+ size_t offset;
+
+ ir = meta_reader_create(fd, cmp, super->inode_table_start,
+ super->directory_table_start);
+ if (ir == NULL)
+ return -1;
+
+ limit = super->id_table_start;
+ if (super->export_table_start < limit)
+ limit = super->export_table_start;
+ if (super->fragment_table_start < limit)
+ limit = super->fragment_table_start;
+
+ dr = meta_reader_create(fd, cmp, super->directory_table_start, limit);
+ if (dr == NULL)
+ goto out_ir;
+
+ if (id_table_init(&idtbl))
+ goto out_dr;
+
+ if (id_table_read(&idtbl, fd, super, cmp))
+ goto out_id;
+
+ xr = xattr_reader_create(fd, super, cmp);
+ if (xr == NULL)
+ goto out_id;
+
+ block_start = super->root_inode_ref >> 16;
+ offset = super->root_inode_ref & 0xFFFF;
+ root = meta_reader_read_inode(ir, super, block_start, offset);
+ if (root == NULL)
+ goto out_xr;
+
+ if (root->base.type != SQFS_INODE_DIR &&
+ root->base.type != SQFS_INODE_EXT_DIR) {
+ free(root);
+ fputs("File system root inode is not a directory inode!\n",
+ stderr);
+ goto out_xr;
+ }
+
+ memset(out, 0, sizeof(*out));
+ out->block_size = super->block_size;
+ out->defaults.st_uid = 0;
+ out->defaults.st_gid = 0;
+ out->defaults.st_mode = 0755;
+ out->defaults.st_mtime = super->modification_time;
+
+ out->root = tree_node_from_inode(root, &idtbl, "", super->block_size);
+
+ if (out->root == NULL) {
+ free(root);
+ goto out_xr;
+ }
+
+ if (flags & RDTREE_READ_XATTR) {
+ if (str_table_init(&out->xattr_keys,
+ FSTREE_XATTR_KEY_BUCKETS)) {
+ free(root);
+ goto fail_fs;
+ }
+
+ if (str_table_init(&out->xattr_values,
+ FSTREE_XATTR_VALUE_BUCKETS)) {
+ free(root);
+ goto fail_fs;
+ }
+
+ if (restore_xattr(xr, out, out->root, root)) {
+ free(root);
+ goto fail_fs;
+ }
+ }
+
+ free(root);
+
+ if (fill_dir(ir, dr, out->root, super, &idtbl, out, xr, flags))
+ goto fail_fs;
+
+ tree_node_sort_recursive(out->root);
+
+ status = 0;
+out_xr:
+ xattr_reader_destroy(xr);
+out_id:
+ id_table_cleanup(&idtbl);
+out_dr:
+ meta_reader_destroy(dr);
+out_ir:
+ meta_reader_destroy(ir);
+ return status;
+fail_fs:
+ fstree_cleanup(out);
+ goto out_xr;
+}