cleanup: move tree deserialization to libsqfs.a

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

3 files changed, 338 insertions, 0 deletions

diff --git a/lib/Makemodule.am b/lib/Makemodule.am
index ff63a7f..9496a9d 100644
--- a/lib/Makemodule.am
+++ b/lib/Makemodule.am
@@ -20,6 +20,8 @@ libsquashfs_a_SOURCES += lib/sqfs/id_table_read.c lib/sqfs/read_inode.c
 libsquashfs_a_SOURCES += lib/sqfs/readdir.c lib/sqfs/frag_reader.c
 libsquashfs_a_SOURCES += lib/sqfs/write_dir.c lib/sqfs/write_inode.c
 libsquashfs_a_SOURCES += lib/sqfs/serialize_fstree.c
+libsquashfs_a_SOURCES += lib/sqfs/tree_node_from_inode.c
+libsquashfs_a_SOURCES += lib/sqfs/deserialize_fstree.c
 libsquashfs_a_SOURCES += include/frag_reader.h
 
 libutil_a_SOURCES = lib/util/canonicalize_name.c lib/util/write_retry.c
diff --git a/lib/sqfs/deserialize_fstree.c b/lib/sqfs/deserialize_fstree.c
new file mode 100644
index 0000000..95dce98
--- /dev/null
+++ b/lib/sqfs/deserialize_fstree.c
@@ -0,0 +1,189 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#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 fill_dir(meta_reader_t *ir, meta_reader_t *dr, tree_node_t *root,
+		    sqfs_super_t *super, id_table_t *idtbl, 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;
+
+	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;
+
+			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);
+			free(ent);
+			free(inode);
+
+			if (n == NULL)
+				return -1;
+
+			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, 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)
+{
+	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, flags))
+		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/lib/sqfs/tree_node_from_inode.c b/lib/sqfs/tree_node_from_inode.c
new file mode 100644
index 0000000..f9a6599
--- /dev/null
+++ b/lib/sqfs/tree_node_from_inode.c
@@ -0,0 +1,147 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "highlevel.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+static size_t compute_size(sqfs_inode_generic_t *inode, const char *name,
+			   size_t block_size)
+{
+	size_t size = sizeof(tree_node_t) + strlen(name) + 1;
+	size_t block_count = 0;
+
+	switch (inode->base.type) {
+	case SQFS_INODE_DIR:
+	case SQFS_INODE_EXT_DIR:
+		size += sizeof(dir_info_t);
+		break;
+	case SQFS_INODE_FILE:
+		size += sizeof(file_info_t);
+		block_count = inode->data.file.file_size / block_size;
+		break;
+	case SQFS_INODE_EXT_FILE:
+		size += sizeof(file_info_t);
+		block_count = inode->data.file_ext.file_size / block_size;
+		break;
+	case SQFS_INODE_SLINK:
+	case SQFS_INODE_EXT_SLINK:
+		size += strlen(inode->slink_target) + 1;
+		break;
+	default:
+		break;
+	}
+
+	return size + block_count * sizeof(uint32_t);
+}
+
+static void copy_block_sizes(sqfs_inode_generic_t *inode, tree_node_t *out,
+			     size_t block_size)
+{
+	size_t block_count = out->data.file->size / block_size;
+
+	out->name += block_count * sizeof(uint32_t);
+
+	if (block_count) {
+		memcpy(out->data.file->blocksizes, inode->block_sizes,
+		       block_count * sizeof(uint32_t));
+	}
+}
+
+tree_node_t *tree_node_from_inode(sqfs_inode_generic_t *inode,
+				  const id_table_t *idtbl,
+				  const char *name,
+				  size_t block_size)
+{
+	tree_node_t *out;
+
+	if (inode->base.uid_idx >= idtbl->num_ids) {
+		fputs("converting inode to fs tree node: UID out of range\n",
+		      stderr);
+		return NULL;
+	}
+
+	if (inode->base.gid_idx >= idtbl->num_ids) {
+		fputs("converting inode to fs tree node: GID out of range\n",
+		      stderr);
+		return NULL;
+	}
+
+	out = calloc(1, compute_size(inode, name, block_size));
+	if (out == NULL) {
+		perror("converting inode to fs tree node");
+		return NULL;
+	}
+
+	out->uid = idtbl->ids[inode->base.uid_idx];
+	out->gid = idtbl->ids[inode->base.gid_idx];
+	out->mode = inode->base.mode;
+	out->inode_num = inode->base.inode_number;
+	out->name = (char *)out->payload;
+
+	switch (inode->base.type) {
+	case SQFS_INODE_DIR:
+		out->data.dir = (dir_info_t *)out->payload;
+		out->name += sizeof(dir_info_t);
+
+		out->data.dir->size = inode->data.dir.size;
+		out->data.dir->start_block = inode->data.dir.start_block;
+		out->data.dir->block_offset = inode->data.dir.offset;
+		break;
+	case SQFS_INODE_EXT_DIR:
+		out->data.dir = (dir_info_t *)out->payload;
+		out->name += sizeof(dir_info_t);
+
+		out->data.dir->size = inode->data.dir_ext.size;
+		out->data.dir->start_block = inode->data.dir_ext.start_block;
+		out->data.dir->block_offset = inode->data.dir_ext.offset;
+		break;
+	case SQFS_INODE_FILE:
+		out->data.file = (file_info_t *)out->payload;
+		out->name += sizeof(file_info_t);
+
+		out->data.file->size = inode->data.file.file_size;
+		out->data.file->startblock = inode->data.file.blocks_start;
+		out->data.file->fragment = inode->data.file.fragment_index;
+		out->data.file->fragment_offset =
+			inode->data.file.fragment_offset;
+
+		copy_block_sizes(inode, out, block_size);
+		break;
+	case SQFS_INODE_EXT_FILE:
+		out->data.file = (file_info_t *)out->payload;
+		out->name += sizeof(file_info_t);
+
+		out->data.file->size = inode->data.file_ext.file_size;
+		out->data.file->startblock = inode->data.file_ext.blocks_start;
+		out->data.file->fragment = inode->data.file_ext.fragment_idx;
+		out->data.file->fragment_offset =
+			inode->data.file_ext.fragment_offset;
+
+		copy_block_sizes(inode, out, block_size);
+		break;
+	case SQFS_INODE_SLINK:
+	case SQFS_INODE_EXT_SLINK:
+		out->data.slink_target = (char *)out->payload;
+		strcpy(out->data.slink_target, inode->slink_target);
+
+		out->name = (char *)out->payload +
+			strlen(inode->slink_target) + 1;
+		break;
+	case SQFS_INODE_BDEV:
+	case SQFS_INODE_CDEV:
+		out->name = (char *)out->payload;
+		out->data.devno = inode->data.dev.devno;
+		break;
+	case SQFS_INODE_EXT_BDEV:
+	case SQFS_INODE_EXT_CDEV:
+		out->name = (char *)out->payload;
+		out->data.devno = inode->data.dev_ext.devno;
+		break;
+	default:
+		break;
+	}
+
+	strcpy(out->name, name);
+	return out;
+}