From 03916fcbb453684fa13135e2b46f5a82d13d78a7 Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Thu, 2 May 2019 08:46:40 +0200 Subject: unsquashfs: restore fstree from image Signed-off-by: David Oberhollenzer --- unpack/Makemodule.am | 2 +- unpack/read_fstree.c | 138 +++++++++++++++++++++++++++++++++++++++++++++++++++ unpack/unsquashfs.c | 10 ++-- unpack/unsquashfs.h | 3 ++ 4 files changed, 145 insertions(+), 8 deletions(-) create mode 100644 unpack/read_fstree.c diff --git a/unpack/Makemodule.am b/unpack/Makemodule.am index e21fd0c..2a08295 100644 --- a/unpack/Makemodule.am +++ b/unpack/Makemodule.am @@ -1,5 +1,5 @@ unsquashfs_SOURCES = unpack/unsquashfs.c unpack/tree_node_from_inode.c -unsquashfs_SOURCES += unpack/unsquashfs.h +unsquashfs_SOURCES += unpack/unsquashfs.h unpack/read_fstree.c unsquashfs_LDADD = libsquashfs.a libfstree.a libcompress.a libutil.a if WITH_LZMA 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; +} diff --git a/unpack/unsquashfs.c b/unpack/unsquashfs.c index 1493081..d332dee 100644 --- a/unpack/unsquashfs.c +++ b/unpack/unsquashfs.c @@ -8,7 +8,7 @@ int main(int argc, char **argv) int fd, status = EXIT_FAILURE; sqfs_super_t super; compressor_t *cmp; - id_table_t idtbl; + fstree_t fs; if (argc != 2) { fprintf(stderr, "Usage: %s \n", __progname); @@ -51,15 +51,11 @@ int main(int argc, char **argv) if (cmp == NULL) goto out; - if (id_table_init(&idtbl)) + if (read_fstree(&fs, fd, &super, cmp)) goto out_cmp; - if (id_table_read(&idtbl, fd, &super, cmp)) - goto out_idtbl; - status = EXIT_SUCCESS; -out_idtbl: - id_table_cleanup(&idtbl); + fstree_cleanup(&fs); out_cmp: cmp->destroy(cmp); out: diff --git a/unpack/unsquashfs.h b/unpack/unsquashfs.h index e50646d..5553012 100644 --- a/unpack/unsquashfs.h +++ b/unpack/unsquashfs.h @@ -2,6 +2,7 @@ #ifndef UNSQUASHFS_H #define UNSQUASHFS_H +#include "meta_reader.h" #include "squashfs.h" #include "compress.h" #include "id_table.h" @@ -18,4 +19,6 @@ tree_node_t *tree_node_from_inode(sqfs_inode_generic_t *inode, const char *name, size_t block_size); +int read_fstree(fstree_t *out, int fd, sqfs_super_t *super, compressor_t *cmp); + #endif /* UNSQUASHFS_H */ -- cgit v1.2.3