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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-05-02 08:46:40 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-05-03 21:45:46 +0200
commit03916fcbb453684fa13135e2b46f5a82d13d78a7 (patch)
treea0ef9caedfbbec98915b4675fccb8717ce58fd91 /unpack/read_fstree.c
parent83183717feca5c673d614e341bfca49fae9a8001 (diff)
unsquashfs: restore fstree from image
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'unpack/read_fstree.c')
-rw-r--r--unpack/read_fstree.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/unpack/read_fstree.c b/unpack/read_fstree.c
new file mode 100644
index 0000000..a6903b0
--- /dev/null
+++ b/unpack/read_fstree.c
@@ -0,0 +1,138 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "unsquashfs.h"
+
+
+static int fill_dir(meta_reader_t *ir, meta_reader_t *dr, tree_node_t *root,
+ sqfs_super_t *super, id_table_t *idtbl)
+{
+ sqfs_inode_generic_t *inode;
+ sqfs_dir_header_t hdr;
+ sqfs_dir_entry_t *ent;
+ uint64_t block_start;
+ size_t size, diff;
+ tree_node_t *n;
+ uint32_t i;
+
+ 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;
+
+ size = root->data.dir->size;
+
+ while (size != 0) {
+ if (meta_reader_read_dir_header(dr, &hdr))
+ return -1;
+
+ size -= sizeof(hdr) > size ? size : sizeof(hdr);
+
+ for (i = 0; i <= hdr.count; ++i) {
+ ent = meta_reader_read_dir_ent(dr);
+ if (ent == NULL)
+ return -1;
+
+ diff = sizeof(*ent) + strlen((char *)ent->name);
+ size -= diff > size ? size : diff;
+
+ 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);
+ free(ent);
+ free(inode);
+
+ if (n == NULL)
+ return -1;
+
+ n->parent = root;
+ n->next = root->data.dir->children;
+ root->data.dir->children = n;
+ }
+ }
+
+ for (n = root->data.dir->children; n != NULL; n = n->next) {
+ if (S_ISDIR(n->mode)) {
+ if (fill_dir(ir, dr, n, super, idtbl))
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+int read_fstree(fstree_t *out, int fd, sqfs_super_t *super, compressor_t *cmp)
+{
+ sqfs_inode_generic_t *root;
+ meta_reader_t *ir, *dr;
+ uint64_t block_start;
+ id_table_t idtbl;
+ int status = -1;
+ size_t offset;
+
+ ir = meta_reader_create(fd, cmp);
+ if (ir == NULL)
+ return -1;
+
+ dr = meta_reader_create(fd, cmp);
+ 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;
+
+ 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_id;
+
+ 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_id;
+ }
+
+ memset(out, 0, sizeof(*out));
+ out->block_size = super->block_size;
+ out->default_uid = 0;
+ out->default_gid = 0;
+ out->default_mode = 0755;
+ out->default_mtime = super->modification_time;
+
+ out->root = tree_node_from_inode(root, &idtbl, "", super->block_size);
+ free(root);
+ root = NULL;
+
+ if (out->root == NULL)
+ goto out_id;
+
+ if (fill_dir(ir, dr, out->root, super, &idtbl))
+ goto fail_fs;
+
+ fstree_sort(out);
+
+ status = 0;
+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_id;
+}