Split fstree inode serialization, move independend part to libsquashfs.so

This commit adds a function to libsquashfs.so for writing generic inodes
to a meta writer and another function to libsqfshelper.a that turns a
tree node to an inode. That way, the tree serialization code can be
expressed in terms of those functions and a bulk of the independend code
can be moved over to libsquashfs.so

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

1 files changed, 228 insertions, 0 deletions

diff --git a/lib/sqfshelper/tree_node_to_inode.c b/lib/sqfshelper/tree_node_to_inode.c
new file mode 100644
index 0000000..21e30dd
--- /dev/null
+++ b/lib/sqfshelper/tree_node_to_inode.c
@@ -0,0 +1,228 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * write_inode.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include "highlevel.h"
+#include "sqfs/inode.h"
+#include "sqfs/dir.h"
+#include "util.h"
+
+#include <assert.h>
+#include <endian.h>
+#include <stdlib.h>
+#include <string.h>
+
+static size_t hard_link_count(tree_node_t *n)
+{
+	size_t count;
+
+	if (S_ISDIR(n->mode)) {
+		count = 2;
+
+		for (n = n->data.dir->children; n != NULL; n = n->next)
+			++count;
+
+		return count;
+	}
+
+	return 1;
+}
+
+static int get_type(tree_node_t *node)
+{
+	switch (node->mode & S_IFMT) {
+	case S_IFSOCK:
+		if (node->xattr != NULL)
+			return SQFS_INODE_EXT_SOCKET;
+		return SQFS_INODE_SOCKET;
+	case S_IFIFO:
+		if (node->xattr != NULL)
+			return SQFS_INODE_EXT_FIFO;
+		return SQFS_INODE_FIFO;
+	case S_IFLNK:
+		if (node->xattr != NULL)
+			return SQFS_INODE_EXT_SLINK;
+		return SQFS_INODE_SLINK;
+	case S_IFBLK:
+		if (node->xattr != NULL)
+			return SQFS_INODE_EXT_BDEV;
+		return SQFS_INODE_BDEV;
+	case S_IFCHR:
+		if (node->xattr != NULL)
+			return SQFS_INODE_EXT_CDEV;
+		return SQFS_INODE_CDEV;
+	case S_IFREG: {
+		file_info_t *fi = node->data.file;
+
+		if (node->xattr != NULL || fi->sparse > 0)
+			return SQFS_INODE_EXT_FILE;
+
+		if (fi->startblock > 0xFFFFFFFFUL || fi->size > 0xFFFFFFFFUL)
+			return SQFS_INODE_EXT_FILE;
+
+		return SQFS_INODE_FILE;
+	}
+	case S_IFDIR: {
+		dir_info_t *di = node->data.dir;
+
+		if (node->xattr != NULL)
+			return SQFS_INODE_EXT_DIR;
+
+		if (di->start_block > 0xFFFFFFFFUL || di->size > 0xFFFF)
+			return SQFS_INODE_EXT_DIR;
+
+		return SQFS_INODE_DIR;
+	}
+	}
+	assert(0);
+}
+
+sqfs_inode_generic_t *tree_node_to_inode(fstree_t *fs, id_table_t *idtbl,
+					 tree_node_t *node,
+					 size_t *file_num_blocks)
+{
+	size_t i, extra = 0, block_count = 0;
+	sqfs_inode_generic_t *inode;
+	uint16_t uid_idx, gid_idx;
+	uint32_t xattr = 0xFFFFFFFF;
+	file_info_t *fi = NULL;
+
+	if (S_ISLNK(node->mode)) {
+		extra = strlen(node->data.slink_target);
+	} else if (S_ISREG(node->mode)) {
+		fi = node->data.file;
+
+		block_count = fi->size / fs->block_size;
+
+		if ((fi->size % fs->block_size) != 0 &&
+		    !(fi->flags & FILE_FLAG_HAS_FRAGMENT)) {
+			++block_count;
+		}
+
+		extra = block_count * sizeof(uint32_t);
+	}
+
+	inode = alloc_flex(sizeof(*inode), 1, extra);
+	if (inode == NULL) {
+		perror("creating inode from file system tree node");
+		return NULL;
+	}
+
+	if (S_ISLNK(node->mode)) {
+		inode->slink_target = (char *)inode->extra;
+
+		memcpy(inode->extra, node->data.slink_target, extra);
+	} else if (S_ISREG(node->mode)) {
+		inode->block_sizes = (uint32_t *)inode->extra;
+
+		for (i = 0; i < block_count; ++i) {
+			inode->block_sizes[i] =
+				node->data.file->blocks[i].size;
+		}
+	}
+
+	if (id_table_id_to_index(idtbl, node->uid, &uid_idx))
+		goto fail;
+
+	if (id_table_id_to_index(idtbl, node->gid, &gid_idx))
+		goto fail;
+
+	if (node->xattr != NULL)
+		xattr = node->xattr->index;
+
+	inode->base.type = get_type(node);
+	inode->base.mode = node->mode;
+	inode->base.uid_idx = uid_idx;
+	inode->base.gid_idx = gid_idx;
+	inode->base.mod_time = node->mod_time;
+	inode->base.inode_number = node->inode_num;
+
+	switch (inode->base.type) {
+	case SQFS_INODE_FIFO:
+	case SQFS_INODE_SOCKET:
+		inode->data.ipc.nlink = hard_link_count(node);
+		break;
+	case SQFS_INODE_EXT_FIFO:
+	case SQFS_INODE_EXT_SOCKET:
+		inode->data.ipc_ext.nlink = hard_link_count(node);
+		inode->data.ipc_ext.xattr_idx = xattr;
+		break;
+	case SQFS_INODE_SLINK:
+		inode->data.slink.nlink = hard_link_count(node);
+		inode->data.slink.target_size = extra;
+		break;
+	case SQFS_INODE_EXT_SLINK:
+		inode->data.slink_ext.nlink = hard_link_count(node);
+		inode->data.slink_ext.target_size = extra;
+		inode->data.slink_ext.xattr_idx = xattr;
+		break;
+	case SQFS_INODE_BDEV:
+	case SQFS_INODE_CDEV:
+		inode->data.dev.nlink = hard_link_count(node);
+		inode->data.dev.devno = node->data.devno;
+		break;
+	case SQFS_INODE_EXT_BDEV:
+	case SQFS_INODE_EXT_CDEV:
+		inode->data.dev_ext.nlink = hard_link_count(node);
+		inode->data.dev_ext.devno = node->data.devno;
+		inode->data.dev_ext.xattr_idx = xattr;
+		break;
+	case SQFS_INODE_FILE:
+		inode->data.file.blocks_start = fi->startblock;
+		inode->data.file.fragment_index = 0xFFFFFFFF;
+		inode->data.file.fragment_offset = 0xFFFFFFFF;
+		inode->data.file.file_size = fi->size;
+
+		if ((fi->size % fs->block_size) != 0 &&
+		    (fi->flags & FILE_FLAG_HAS_FRAGMENT)) {
+			inode->data.file.fragment_index = fi->fragment;
+			inode->data.file.fragment_offset = fi->fragment_offset;
+		}
+		break;
+	case SQFS_INODE_EXT_FILE:
+		inode->data.file_ext.blocks_start = fi->startblock;
+		inode->data.file_ext.file_size = fi->size;
+		inode->data.file_ext.sparse = fi->sparse;
+		inode->data.file_ext.nlink = hard_link_count(node);
+		inode->data.file_ext.fragment_idx = 0xFFFFFFFF;
+		inode->data.file_ext.fragment_offset = 0xFFFFFFFF;
+		inode->data.file_ext.xattr_idx = xattr;
+
+		if ((fi->size % fs->block_size) != 0 &&
+		    (fi->flags & FILE_FLAG_HAS_FRAGMENT)) {
+			inode->data.file_ext.fragment_idx = fi->fragment;
+			inode->data.file_ext.fragment_offset =
+				fi->fragment_offset;
+		}
+		break;
+	case SQFS_INODE_DIR:
+		inode->data.dir.start_block = node->data.dir->start_block;
+		inode->data.dir.nlink = hard_link_count(node);
+		inode->data.dir.size = node->data.dir->size;
+		inode->data.dir.offset = node->data.dir->block_offset;
+		inode->data.dir.parent_inode = node->parent ?
+			node->parent->inode_num : 1;
+		break;
+	case SQFS_INODE_EXT_DIR:
+		inode->data.dir_ext.nlink = hard_link_count(node);
+		inode->data.dir_ext.size = node->data.dir->size;
+		inode->data.dir_ext.start_block = node->data.dir->start_block;
+		inode->data.dir_ext.parent_inode = node->parent ?
+			node->parent->inode_num : 1;
+		inode->data.dir_ext.offset = node->data.dir->block_offset;
+		inode->data.dir_ext.xattr_idx = xattr;
+		break;
+	default:
+		goto fail;
+	}
+
+	*file_num_blocks = block_count;
+	return inode;
+fail:
+	free(inode);
+	return NULL;
+}