Add helper functions for working with inodes

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

3 files changed, 298 insertions, 31 deletions

diff --git a/lib/sqfs/Makemodule.am b/lib/sqfs/Makemodule.am
index 16a07e9..44b5531 100644
--- a/lib/sqfs/Makemodule.am
+++ b/lib/sqfs/Makemodule.am
@@ -17,6 +17,7 @@ libsquashfs_la_SOURCES += lib/sqfs/dir_writer.c lib/sqfs/xattr_reader.c
 libsquashfs_la_SOURCES += lib/sqfs/read_table.c lib/sqfs/comp/compressor.c
 libsquashfs_la_SOURCES += lib/sqfs/io_stdin.c lib/sqfs/comp/internal.h
 libsquashfs_la_SOURCES += lib/sqfs/dir_reader.c lib/sqfs/read_tree.c
+libsquashfs_la_SOURCES += lib/sqfs/inode.c
 libsquashfs_la_SOURCES += lib/sqfs/blk_proc/process_block.c lib/sqfs/io.c
 libsquashfs_la_SOURCES += lib/sqfs/blk_proc/internal.h lib/sqfs/data_reader.c
 libsquashfs_la_CPPFLAGS = $(AM_CPPFLAGS)
diff --git a/lib/sqfs/data_reader.c b/lib/sqfs/data_reader.c
index 3de59ff..2603cfe 100644
--- a/lib/sqfs/data_reader.c
+++ b/lib/sqfs/data_reader.c
@@ -209,15 +209,8 @@ int sqfs_data_reader_get_block(sqfs_data_reader_t *data,
 	size_t i, unpacked_size;
 	uint64_t off, filesz;
 
-	if (inode->base.type == SQFS_INODE_FILE) {
-		off = inode->data.file.blocks_start;
-		filesz = inode->data.file.file_size;
-	} else if (inode->base.type == SQFS_INODE_EXT_FILE) {
-		off = inode->data.file_ext.blocks_start;
-		filesz = inode->data.file_ext.file_size;
-	} else {
-		return SQFS_ERROR_NOT_FILE;
-	}
+	sqfs_inode_get_file_block_start(inode, &off);
+	sqfs_inode_get_file_size(inode, &filesz);
 
 	if (index >= inode->num_file_blocks)
 		return SQFS_ERROR_OUT_OF_BOUNDS;
@@ -241,17 +234,8 @@ int sqfs_data_reader_get_fragment(sqfs_data_reader_t *data,
 	sqfs_block_t *blk;
 	uint64_t filesz;
 
-	if (inode->base.type == SQFS_INODE_EXT_FILE) {
-		filesz = inode->data.file_ext.file_size;
-		frag_idx = inode->data.file_ext.fragment_idx;
-		frag_off = inode->data.file_ext.fragment_offset;
-	} else if (inode->base.type == SQFS_INODE_FILE) {
-		filesz = inode->data.file.file_size;
-		frag_idx = inode->data.file.fragment_index;
-		frag_off = inode->data.file.fragment_offset;
-	} else {
-		return -1;
-	}
+	sqfs_inode_get_file_size(inode, &filesz);
+	sqfs_inode_get_frag_location(inode, &frag_idx, &frag_off);
 
 	if (inode->num_file_blocks * data->block_size >= filesz) {
 		*out = NULL;
@@ -287,17 +271,9 @@ ssize_t sqfs_data_reader_read(sqfs_data_reader_t *data,
 	char *ptr;
 
 	/* work out file location and size */
-	if (inode->base.type == SQFS_INODE_EXT_FILE) {
-		off = inode->data.file_ext.blocks_start;
-		filesz = inode->data.file_ext.file_size;
-		frag_idx = inode->data.file_ext.fragment_idx;
-		frag_off = inode->data.file_ext.fragment_offset;
-	} else {
-		off = inode->data.file.blocks_start;
-		filesz = inode->data.file.file_size;
-		frag_idx = inode->data.file.fragment_index;
-		frag_off = inode->data.file.fragment_offset;
-	}
+	sqfs_inode_get_file_size(inode, &filesz);
+	sqfs_inode_get_frag_location(inode, &frag_idx, &frag_off);
+	sqfs_inode_get_file_block_start(inode, &off);
 
 	/* find location of the first block */
 	i = 0;
diff --git a/lib/sqfs/inode.c b/lib/sqfs/inode.c
new file mode 100644
index 0000000..d6c013c
--- /dev/null
+++ b/lib/sqfs/inode.c
@@ -0,0 +1,290 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * inode.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "config.h"
+
+#include "sqfs/inode.h"
+#include "sqfs/error.h"
+
+static int inverse_type[] = {
+	[SQFS_INODE_DIR] = SQFS_INODE_EXT_DIR,
+	[SQFS_INODE_FILE] = SQFS_INODE_EXT_FILE,
+	[SQFS_INODE_SLINK] = SQFS_INODE_EXT_SLINK,
+	[SQFS_INODE_BDEV] = SQFS_INODE_EXT_BDEV,
+	[SQFS_INODE_CDEV] = SQFS_INODE_EXT_CDEV,
+	[SQFS_INODE_FIFO] = SQFS_INODE_EXT_FIFO,
+	[SQFS_INODE_SOCKET] = SQFS_INODE_EXT_SOCKET,
+	[SQFS_INODE_EXT_DIR] = SQFS_INODE_DIR,
+	[SQFS_INODE_EXT_FILE] = SQFS_INODE_FILE,
+	[SQFS_INODE_EXT_SLINK] = SQFS_INODE_SLINK,
+	[SQFS_INODE_EXT_BDEV] = SQFS_INODE_BDEV,
+	[SQFS_INODE_EXT_CDEV] = SQFS_INODE_CDEV,
+	[SQFS_INODE_EXT_FIFO] = SQFS_INODE_FIFO,
+	[SQFS_INODE_EXT_SOCKET] = SQFS_INODE_SOCKET,
+};
+
+int sqfs_inode_get_xattr_index(const sqfs_inode_generic_t *inode,
+			       uint32_t *out)
+{
+	switch (inode->base.type) {
+	case SQFS_INODE_DIR:
+	case SQFS_INODE_FILE:
+	case SQFS_INODE_SLINK:
+	case SQFS_INODE_BDEV:
+	case SQFS_INODE_CDEV:
+	case SQFS_INODE_FIFO:
+	case SQFS_INODE_SOCKET:
+		*out = 0xFFFFFFFF;
+		break;
+	case SQFS_INODE_EXT_DIR:
+		*out = inode->data.dir_ext.xattr_idx;
+		break;
+	case SQFS_INODE_EXT_FILE:
+		*out = inode->data.file_ext.xattr_idx;
+		break;
+	case SQFS_INODE_EXT_SLINK:
+		*out = inode->data.slink_ext.xattr_idx;
+		break;
+	case SQFS_INODE_EXT_BDEV:
+	case SQFS_INODE_EXT_CDEV:
+		*out = inode->data.dev_ext.xattr_idx;
+		break;
+	case SQFS_INODE_EXT_FIFO:
+	case SQFS_INODE_EXT_SOCKET:
+		*out = inode->data.ipc_ext.xattr_idx;
+		break;
+	default:
+		return SQFS_ERROR_CORRUPTED;
+	}
+
+	return 0;
+}
+
+int sqfs_inode_make_extended(sqfs_inode_generic_t *inode)
+{
+	switch (inode->base.type) {
+	case SQFS_INODE_DIR: {
+		sqfs_inode_dir_ext_t temp = {
+			.nlink = inode->data.dir.nlink,
+			.size = inode->data.dir.size,
+			.start_block = inode->data.dir.start_block,
+			.parent_inode = inode->data.dir.parent_inode,
+			.inodex_count = 0,
+			.offset = inode->data.dir.offset,
+			.xattr_idx = 0xFFFFFFFF,
+		};
+		inode->data.dir_ext = temp;
+		break;
+	}
+	case SQFS_INODE_FILE: {
+		sqfs_inode_file_ext_t temp = {
+			.blocks_start = inode->data.file.blocks_start,
+			.file_size = inode->data.file.file_size,
+			.sparse = 0,
+			.nlink = 1,
+			.fragment_idx = inode->data.file.fragment_index,
+			.fragment_offset = inode->data.file.fragment_offset,
+			.xattr_idx = 0xFFFFFFFF,
+		};
+		inode->data.file_ext = temp;
+		break;
+	}
+	case SQFS_INODE_SLINK:
+		inode->data.slink_ext.xattr_idx = 0xFFFFFFFF;
+		break;
+	case SQFS_INODE_BDEV:
+	case SQFS_INODE_CDEV:
+		inode->data.dev_ext.xattr_idx = 0xFFFFFFFF;
+		break;
+	case SQFS_INODE_FIFO:
+	case SQFS_INODE_SOCKET:
+		inode->data.dev_ext.xattr_idx = 0xFFFFFFFF;
+		break;
+	case SQFS_INODE_EXT_DIR:
+	case SQFS_INODE_EXT_FILE:
+	case SQFS_INODE_EXT_SLINK:
+	case SQFS_INODE_EXT_BDEV:
+	case SQFS_INODE_EXT_CDEV:
+	case SQFS_INODE_EXT_FIFO:
+	case SQFS_INODE_EXT_SOCKET:
+		return 0;
+	default:
+		return SQFS_ERROR_CORRUPTED;
+	}
+
+	inode->base.type = inverse_type[inode->base.type];
+	return 0;
+}
+
+int sqfs_inode_make_basic(sqfs_inode_generic_t *inode)
+{
+	uint32_t xattr;
+	int err;
+
+	err = sqfs_inode_get_xattr_index(inode, &xattr);
+	if (err != 0 || xattr != 0xFFFFFFFF)
+		return err;
+
+	switch (inode->base.type) {
+	case SQFS_INODE_DIR:
+	case SQFS_INODE_FILE:
+	case SQFS_INODE_SLINK:
+	case SQFS_INODE_BDEV:
+	case SQFS_INODE_CDEV:
+	case SQFS_INODE_FIFO:
+	case SQFS_INODE_SOCKET:
+		return 0;
+	case SQFS_INODE_EXT_DIR: {
+		sqfs_inode_dir_t temp = {
+			.start_block = inode->data.dir_ext.start_block,
+			.nlink = inode->data.dir_ext.nlink,
+			.size = inode->data.dir_ext.size,
+			.offset = inode->data.dir_ext.offset,
+			.parent_inode = inode->data.dir_ext.parent_inode,
+		};
+
+		if (inode->data.dir_ext.size > 0x0FFFF)
+			return 0;
+
+		inode->data.dir = temp;
+		break;
+	}
+	case SQFS_INODE_EXT_FILE: {
+		sqfs_inode_file_t temp = {
+			.blocks_start = inode->data.file_ext.blocks_start,
+			.fragment_index = inode->data.file_ext.fragment_idx,
+			.fragment_offset = inode->data.file_ext.fragment_offset,
+			.file_size = inode->data.file_ext.file_size,
+		};
+
+		if (inode->data.file_ext.blocks_start > 0x0FFFFFFFFUL)
+			return 0;
+		if (inode->data.file_ext.file_size > 0x0FFFFFFFFUL)
+			return 0;
+		if (inode->data.file_ext.sparse > 0)
+			return 0;
+		if (inode->data.file_ext.nlink > 1)
+			return 0;
+
+		inode->data.file = temp;
+		break;
+	}
+	case SQFS_INODE_EXT_SLINK:
+	case SQFS_INODE_EXT_BDEV:
+	case SQFS_INODE_EXT_CDEV:
+	case SQFS_INODE_EXT_FIFO:
+	case SQFS_INODE_EXT_SOCKET:
+		break;
+	default:
+		return SQFS_ERROR_CORRUPTED;
+	}
+
+	inode->base.type = inverse_type[inode->base.type];
+	return 0;
+}
+
+int sqfs_inode_set_file_size(sqfs_inode_generic_t *inode, uint64_t size)
+{
+	if (inode->base.type == SQFS_INODE_EXT_FILE) {
+		inode->data.file_ext.file_size = size;
+
+		if (size < 0x0FFFFFFFFUL)
+			sqfs_inode_make_basic(inode);
+	} else if (inode->base.type == SQFS_INODE_FILE) {
+		if (size > 0x0FFFFFFFFUL) {
+			sqfs_inode_make_extended(inode);
+			inode->data.file_ext.file_size = size;
+		} else {
+			inode->data.file.file_size = size;
+		}
+	} else {
+		return SQFS_ERROR_NOT_FILE;
+	}
+
+	return 0;
+}
+
+int sqfs_inode_set_frag_location(sqfs_inode_generic_t *inode,
+				 uint32_t index, uint32_t offset)
+{
+	if (inode->base.type == SQFS_INODE_EXT_FILE) {
+		inode->data.file_ext.fragment_idx = index;
+		inode->data.file_ext.fragment_offset = offset;
+	} else if (inode->base.type == SQFS_INODE_FILE) {
+		inode->data.file.fragment_index = index;
+		inode->data.file.fragment_offset = offset;
+	} else {
+		return SQFS_ERROR_NOT_FILE;
+	}
+
+	return 0;
+}
+
+int sqfs_inode_set_file_block_start(sqfs_inode_generic_t *inode,
+				    uint64_t location)
+{
+	if (inode->base.type == SQFS_INODE_EXT_FILE) {
+		inode->data.file_ext.blocks_start = location;
+
+		if (location < 0x0FFFFFFFFUL)
+			sqfs_inode_make_basic(inode);
+	} else if (inode->base.type == SQFS_INODE_FILE) {
+		if (location > 0x0FFFFFFFFUL) {
+			sqfs_inode_make_extended(inode);
+			inode->data.file_ext.blocks_start = location;
+		} else {
+			inode->data.file.blocks_start = location;
+		}
+	} else {
+		return SQFS_ERROR_NOT_FILE;
+	}
+
+	return 0;
+}
+
+int sqfs_inode_get_file_size(const sqfs_inode_generic_t *inode, uint64_t *size)
+{
+	if (inode->base.type == SQFS_INODE_EXT_FILE) {
+		*size = inode->data.file_ext.file_size;
+	} else if (inode->base.type == SQFS_INODE_FILE) {
+		*size = inode->data.file.file_size;
+	} else {
+		return SQFS_ERROR_NOT_FILE;
+	}
+
+	return 0;
+}
+
+int sqfs_inode_get_frag_location(const sqfs_inode_generic_t *inode,
+				 uint32_t *index, uint32_t *offset)
+{
+	if (inode->base.type == SQFS_INODE_EXT_FILE) {
+		*index = inode->data.file_ext.fragment_idx;
+		*offset = inode->data.file_ext.fragment_offset;
+	} else if (inode->base.type == SQFS_INODE_FILE) {
+		*index = inode->data.file.fragment_index;
+		*offset = inode->data.file.fragment_offset;
+	} else {
+		return SQFS_ERROR_NOT_FILE;
+	}
+
+	return 0;
+}
+
+int sqfs_inode_get_file_block_start(const sqfs_inode_generic_t *inode,
+				    uint64_t *location)
+{
+	if (inode->base.type == SQFS_INODE_EXT_FILE) {
+		*location = inode->data.file_ext.blocks_start;
+	} else if (inode->base.type == SQFS_INODE_FILE) {
+		*location = inode->data.file.blocks_start;
+	} else {
+		return SQFS_ERROR_NOT_FILE;
+	}
+
+	return 0;
+}