Cleanup directory structure of the binary programs

Instead of having the binary programs in randomly named subdirectories,
move all of them to a "bin" subdirectory, similar to the utility
libraries that have subdirectories within "lib" and give the
subdirectories the propper names (e.g. have gensquashfs source in a
directory *actually* named "gensquashfs").

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

5 files changed, 976 insertions, 0 deletions

diff --git a/bin/gensquashfs/dirscan.c b/bin/gensquashfs/dirscan.c
new file mode 100644
index 0000000..dbc862c
--- /dev/null
+++ b/bin/gensquashfs/dirscan.c
@@ -0,0 +1,321 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * fstree_from_dir.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "mkfs.h"
+
+#ifdef HAVE_SYS_XATTR_H
+static char *get_full_path(const char *prefix, tree_node_t *node)
+{
+	char *path = NULL, *new = NULL;
+	size_t path_len, prefix_len;
+	int ret;
+
+	path = fstree_get_path(node);
+	if (path == NULL)
+		goto fail;
+
+	ret = canonicalize_name(path);
+	assert(ret == 0);
+
+	path_len = strlen(path);
+	prefix_len = strlen(prefix);
+
+	while (prefix_len > 0 && prefix[prefix_len - 1] == '/')
+		--prefix_len;
+
+	if (prefix_len > 0) {
+		new = realloc(path, path_len + prefix_len + 2);
+		if (new == NULL)
+			goto fail;
+
+		path = new;
+
+		memmove(path + prefix_len + 1, path, path_len + 1);
+		memcpy(path, prefix, prefix_len);
+		path[prefix_len] = '/';
+	}
+
+	return path;
+fail:
+	perror("getting full path for xattr scan");
+	free(path);
+	return NULL;
+}
+
+static int xattr_from_path(sqfs_xattr_writer_t *xwr, const char *path)
+{
+	char *key, *value = NULL, *buffer = NULL;
+	ssize_t buflen, vallen, keylen;
+	int ret;
+
+	buflen = llistxattr(path, NULL, 0);
+	if (buflen < 0) {
+		fprintf(stderr, "llistxattr %s: %s", path, strerror(errno));
+		return -1;
+	}
+
+	if (buflen == 0)
+		return 0;
+
+	buffer = malloc(buflen);
+	if (buffer == NULL) {
+		perror("xattr name buffer");
+		return -1;
+	}
+
+	buflen = llistxattr(path, buffer, buflen);
+	if (buflen == -1) {
+		fprintf(stderr, "llistxattr %s: %s", path, strerror(errno));
+		goto fail;
+	}
+
+	key = buffer;
+	while (buflen > 0) {
+		vallen = lgetxattr(path, key, NULL, 0);
+		if (vallen == -1) {
+			fprintf(stderr, "lgetxattr %s: %s",
+				path, strerror(errno));
+			goto fail;
+		}
+
+		if (vallen > 0) {
+			value = calloc(1, vallen);
+			if (value == NULL) {
+				perror("allocating xattr value buffer");
+				goto fail;
+			}
+
+			vallen = lgetxattr(path, key, value, vallen);
+			if (vallen == -1) {
+				fprintf(stderr, "lgetxattr %s: %s\n",
+					path, strerror(errno));
+				goto fail;
+			}
+
+			ret = sqfs_xattr_writer_add(xwr, key, value, vallen);
+			if (ret) {
+				sqfs_perror(path,
+					    "storing xattr key-value pairs",
+					    ret);
+				goto fail;
+			}
+
+			free(value);
+			value = NULL;
+		}
+
+		keylen = strlen(key) + 1;
+		buflen -= keylen;
+		key += keylen;
+	}
+
+	free(buffer);
+	return 0;
+fail:
+	free(value);
+	free(buffer);
+	return -1;
+}
+#endif
+
+#ifdef _WIN32
+int fstree_from_dir(fstree_t *fs, const char *path, void *selinux_handle,
+		    sqfs_xattr_writer_t *xwr, unsigned int flags)
+{
+	(void)fs; (void)path; (void)selinux_handle; (void)xwr; (void)flags;
+	fputs("Packing a directory is not supported on Windows.\n", stderr);
+	return -1;
+}
+#else
+static int xattr_xcan_dfs(const char *path_prefix, void *selinux_handle,
+			  sqfs_xattr_writer_t *xwr, unsigned int flags,
+			  tree_node_t *node)
+{
+	char *path;
+	int ret;
+
+	ret = sqfs_xattr_writer_begin(xwr);
+	if (ret) {
+		sqfs_perror(node->name, "recoding xattr key-value pairs\n",
+			    ret);
+		return -1;
+	}
+
+#ifdef HAVE_SYS_XATTR_H
+	if (flags & DIR_SCAN_READ_XATTR) {
+		path = get_full_path(path_prefix, node);
+		if (path == NULL)
+			return -1;
+
+		ret = xattr_from_path(xwr, path);
+		free(path);
+
+		if (ret)
+			return -1;
+	}
+#else
+	(void)path_prefix;
+#endif
+
+	if (selinux_handle != NULL) {
+		path = fstree_get_path(node);
+		if (path == NULL) {
+			perror("reconstructing absolute path");
+			return -1;
+		}
+
+		ret = selinux_relable_node(selinux_handle, xwr, node, path);
+		free(path);
+
+		if (ret)
+			return -1;
+	}
+
+	if (sqfs_xattr_writer_end(xwr, &node->xattr_idx)) {
+		sqfs_perror(node->name, "completing xattr key-value pairs",
+			    ret);
+		return -1;
+	}
+
+	if (S_ISDIR(node->mode)) {
+		node = node->data.dir.children;
+
+		while (node != NULL) {
+			if (xattr_xcan_dfs(path_prefix, selinux_handle, xwr,
+					   flags, node)) {
+				return -1;
+			}
+
+			node = node->next;
+		}
+	}
+
+	return 0;
+}
+
+static int populate_dir(int dir_fd, fstree_t *fs, tree_node_t *root,
+			dev_t devstart, unsigned int flags)
+{
+	char *extra = NULL;
+	struct dirent *ent;
+	struct stat sb;
+	tree_node_t *n;
+	int childfd;
+	DIR *dir;
+
+	dir = fdopendir(dir_fd);
+	if (dir == NULL) {
+		perror("fdopendir");
+		close(dir_fd);
+		return -1;
+	}
+
+	/* XXX: fdopendir can dup and close dir_fd internally
+	   and still be compliant with the spec. */
+	dir_fd = dirfd(dir);
+
+	for (;;) {
+		errno = 0;
+		ent = readdir(dir);
+
+		if (ent == NULL) {
+			if (errno) {
+				perror("readdir");
+				goto fail;
+			}
+			break;
+		}
+
+		if (!strcmp(ent->d_name, "..") || !strcmp(ent->d_name, "."))
+			continue;
+
+		if (fstatat(dir_fd, ent->d_name, &sb, AT_SYMLINK_NOFOLLOW)) {
+			perror(ent->d_name);
+			goto fail;
+		}
+
+		if ((flags & DIR_SCAN_ONE_FILESYSTEM) && sb.st_dev != devstart)
+			continue;
+
+		if (S_ISLNK(sb.st_mode)) {
+			extra = calloc(1, sb.st_size + 1);
+			if (extra == NULL)
+				goto fail_rdlink;
+
+			if (readlinkat(dir_fd, ent->d_name,
+				       extra, sb.st_size) < 0) {
+				goto fail_rdlink;
+			}
+
+			extra[sb.st_size] = '\0';
+		}
+
+		if (!(flags & DIR_SCAN_KEEP_TIME))
+			sb.st_mtime = fs->defaults.st_mtime;
+
+		n = fstree_mknode(root, ent->d_name, strlen(ent->d_name),
+				  extra, &sb);
+		if (n == NULL) {
+			perror("creating tree node");
+			goto fail;
+		}
+
+		free(extra);
+		extra = NULL;
+
+		if (S_ISDIR(n->mode)) {
+			childfd = openat(dir_fd, n->name, O_DIRECTORY |
+					 O_RDONLY | O_CLOEXEC);
+			if (childfd < 0) {
+				perror(n->name);
+				goto fail;
+			}
+
+			if (populate_dir(childfd, fs, n, devstart, flags))
+				goto fail;
+		}
+	}
+
+	closedir(dir);
+	return 0;
+fail_rdlink:
+	perror("readlink");
+fail:
+	closedir(dir);
+	free(extra);
+	return -1;
+}
+
+int fstree_from_dir(fstree_t *fs, const char *path, void *selinux_handle,
+		    sqfs_xattr_writer_t *xwr, unsigned int flags)
+{
+	struct stat sb;
+	int fd;
+
+	fd = open(path, O_DIRECTORY | O_RDONLY | O_CLOEXEC);
+	if (fd < 0) {
+		perror(path);
+		return -1;
+	}
+
+	if (fstat(fd, &sb)) {
+		perror(path);
+		close(fd);
+		return -1;
+	}
+
+	if (populate_dir(fd, fs, fs->root, sb.st_dev, flags))
+		return -1;
+
+	if (xwr != NULL && (selinux_handle != NULL ||
+			    (flags & DIR_SCAN_READ_XATTR))) {
+		if (xattr_xcan_dfs(path, selinux_handle, xwr, flags, fs->root))
+			return -1;
+	}
+
+	return 0;
+}
+#endif
diff --git a/bin/gensquashfs/mkfs.c b/bin/gensquashfs/mkfs.c
new file mode 100644
index 0000000..9ffbb94
--- /dev/null
+++ b/bin/gensquashfs/mkfs.c
@@ -0,0 +1,216 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * mkfs.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "mkfs.h"
+
+static int set_working_dir(options_t *opt)
+{
+	const char *ptr;
+	char *path;
+
+	if (opt->packdir != NULL) {
+		if (chdir(opt->packdir)) {
+			perror(opt->packdir);
+			return -1;
+		}
+		return 0;
+	}
+
+	ptr = strrchr(opt->infile, '/');
+	if (ptr == NULL)
+		return 0;
+
+	path = strndup(opt->infile, ptr - opt->infile);
+	if (path == NULL) {
+		perror("constructing input directory path");
+		return -1;
+	}
+
+	if (chdir(path)) {
+		perror(path);
+		free(path);
+		return -1;
+	}
+
+	free(path);
+	return 0;
+}
+
+static int pack_files(sqfs_block_processor_t *data, fstree_t *fs,
+		      options_t *opt)
+{
+	sqfs_inode_generic_t **inode_ptr;
+	sqfs_u64 filesize;
+	sqfs_file_t *file;
+	tree_node_t *node;
+	const char *path;
+	char *node_path;
+	file_info_t *fi;
+	int flags;
+	int ret;
+
+	if (set_working_dir(opt))
+		return -1;
+
+	for (fi = fs->files; fi != NULL; fi = fi->next) {
+		if (fi->input_file == NULL) {
+			node = container_of(fi, tree_node_t, data.file);
+
+			node_path = fstree_get_path(node);
+			if (node_path == NULL) {
+				perror("reconstructing file path");
+				return -1;
+			}
+
+			ret = canonicalize_name(node_path);
+			assert(ret == 0);
+
+			path = node_path;
+		} else {
+			node_path = NULL;
+			path = fi->input_file;
+		}
+
+		if (!opt->cfg.quiet)
+			printf("packing %s\n", path);
+
+		file = sqfs_open_file(path, SQFS_FILE_OPEN_READ_ONLY);
+		if (file == NULL) {
+			perror(path);
+			free(node_path);
+			return -1;
+		}
+
+		flags = 0;
+		filesize = file->get_size(file);
+
+		if (opt->no_tail_packing && filesize > opt->cfg.block_size)
+			flags |= SQFS_BLK_DONT_FRAGMENT;
+
+		inode_ptr = (sqfs_inode_generic_t **)&fi->user_ptr;
+
+		ret = write_data_from_file(path, data, inode_ptr, file, flags);
+		sqfs_destroy(file);
+		free(node_path);
+
+		if (ret)
+			return -1;
+	}
+
+	return 0;
+}
+
+static int relabel_tree_dfs(const char *filename, sqfs_xattr_writer_t *xwr,
+			    tree_node_t *n, void *selinux_handle)
+{
+	char *path = fstree_get_path(n);
+	int ret;
+
+	if (path == NULL) {
+		perror("getting absolute node path for SELinux relabeling");
+		return -1;
+	}
+
+	ret = sqfs_xattr_writer_begin(xwr);
+	if (ret) {
+		sqfs_perror(filename, "recording xattr key-value pairs", ret);
+		return -1;
+	}
+
+	if (selinux_relable_node(selinux_handle, xwr, n, path)) {
+		free(path);
+		return -1;
+	}
+
+	ret = sqfs_xattr_writer_end(xwr, &n->xattr_idx);
+	if (ret) {
+		sqfs_perror(filename, "flushing completed key-value pairs",
+			    ret);
+		return -1;
+	}
+
+	free(path);
+
+	if (S_ISDIR(n->mode)) {
+		for (n = n->data.dir.children; n != NULL; n = n->next) {
+			if (relabel_tree_dfs(filename, xwr, n, selinux_handle))
+				return -1;
+		}
+	}
+
+	return 0;
+}
+
+static int read_fstree(fstree_t *fs, options_t *opt, sqfs_xattr_writer_t *xwr,
+		       void *selinux_handle)
+{
+	FILE *fp;
+	int ret;
+
+	if (opt->infile == NULL) {
+		return fstree_from_dir(fs, opt->packdir, selinux_handle,
+				       xwr, opt->dirscan_flags);
+	}
+
+	fp = fopen(opt->infile, "rb");
+	if (fp == NULL) {
+		perror(opt->infile);
+		return -1;
+	}
+
+	ret = fstree_from_file(fs, opt->infile, fp);
+	fclose(fp);
+
+	if (ret == 0 && selinux_handle != NULL)
+		ret = relabel_tree_dfs(opt->cfg.filename, xwr,
+				       fs->root, selinux_handle);
+
+	return ret;
+}
+
+int main(int argc, char **argv)
+{
+	int status = EXIT_FAILURE;
+	void *sehnd = NULL;
+	sqfs_writer_t sqfs;
+	options_t opt;
+
+	process_command_line(&opt, argc, argv);
+
+	if (sqfs_writer_init(&sqfs, &opt.cfg))
+		return EXIT_FAILURE;
+
+	if (opt.selinux != NULL) {
+		sehnd = selinux_open_context_file(opt.selinux);
+		if (sehnd == NULL)
+			goto out;
+	}
+
+	if (read_fstree(&sqfs.fs, &opt, sqfs.xwr, sehnd)) {
+		if (sehnd != NULL)
+			selinux_close_context_file(sehnd);
+		goto out;
+	}
+
+	if (sehnd != NULL) {
+		selinux_close_context_file(sehnd);
+		sehnd = NULL;
+	}
+
+	if (fstree_post_process(&sqfs.fs))
+		goto out;
+
+	if (pack_files(sqfs.data, &sqfs.fs, &opt))
+		goto out;
+
+	if (sqfs_writer_finish(&sqfs, &opt.cfg))
+		goto out;
+
+	status = EXIT_SUCCESS;
+out:
+	sqfs_writer_cleanup(&sqfs, status);
+	return status;
+}
diff --git a/bin/gensquashfs/mkfs.h b/bin/gensquashfs/mkfs.h
new file mode 100644
index 0000000..1b767aa
--- /dev/null
+++ b/bin/gensquashfs/mkfs.h
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * mkfs.h
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#ifndef MKFS_H
+#define MKFS_H
+
+#include "config.h"
+
+#include "common.h"
+#include "fstree.h"
+
+#ifdef HAVE_SYS_XATTR_H
+#include <sys/xattr.h>
+
+#if defined(__APPLE__) && defined(__MACH__)
+#define llistxattr(path, list, size) \
+	listxattr(path, list, size, XATTR_NOFOLLOW)
+
+#define lgetxattr(path, name, value, size) \
+	getxattr(path, name, value, size, 0, XATTR_NOFOLLOW)
+#endif
+#endif
+
+#ifdef WITH_SELINUX
+#include <selinux/selinux.h>
+#include <selinux/label.h>
+#endif
+
+#include <getopt.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <dirent.h>
+#include <stdio.h>
+#include <errno.h>
+#include <ctype.h>
+
+typedef struct {
+	sqfs_writer_cfg_t cfg;
+	unsigned int dirscan_flags;
+	const char *infile;
+	const char *packdir;
+	const char *selinux;
+	bool no_tail_packing;
+} options_t;
+
+enum {
+	DIR_SCAN_KEEP_TIME = 0x01,
+
+	DIR_SCAN_ONE_FILESYSTEM = 0x02,
+
+	DIR_SCAN_READ_XATTR = 0x04,
+};
+
+void process_command_line(options_t *opt, int argc, char **argv);
+
+int fstree_from_dir(fstree_t *fs, const char *path, void *selinux_handle,
+		    sqfs_xattr_writer_t *xwr, unsigned int flags);
+
+
+void *selinux_open_context_file(const char *filename);
+
+int selinux_relable_node(void *sehnd, sqfs_xattr_writer_t *xwr,
+			 tree_node_t *node, const char *path);
+
+void selinux_close_context_file(void *sehnd);
+
+#endif /* MKFS_H */
diff --git a/bin/gensquashfs/options.c b/bin/gensquashfs/options.c
new file mode 100644
index 0000000..2369787
--- /dev/null
+++ b/bin/gensquashfs/options.c
@@ -0,0 +1,289 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * options.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "mkfs.h"
+
+static struct option long_opts[] = {
+	{ "compressor", required_argument, NULL, 'c' },
+	{ "block-size", required_argument, NULL, 'b' },
+	{ "dev-block-size", required_argument, NULL, 'B' },
+	{ "defaults", required_argument, NULL, 'd' },
+	{ "comp-extra", required_argument, NULL, 'X' },
+	{ "pack-file", required_argument, NULL, 'F' },
+	{ "pack-dir", required_argument, NULL, 'D' },
+	{ "num-jobs", required_argument, NULL, 'j' },
+	{ "queue-backlog", required_argument, NULL, 'Q' },
+	{ "keep-time", no_argument, NULL, 'k' },
+#ifdef HAVE_SYS_XATTR_H
+	{ "keep-xattr", no_argument, NULL, 'x' },
+#endif
+	{ "one-file-system", no_argument, NULL, 'o' },
+	{ "exportable", no_argument, NULL, 'e' },
+	{ "no-tail-packing", no_argument, NULL, 'T' },
+	{ "force", no_argument, NULL, 'f' },
+	{ "quiet", no_argument, NULL, 'q' },
+#ifdef WITH_SELINUX
+	{ "selinux", required_argument, NULL, 's' },
+#endif
+	{ "version", no_argument, NULL, 'V' },
+	{ "help", no_argument, NULL, 'h' },
+	{ NULL, 0, NULL, 0 },
+};
+
+static const char *short_opts = "F:D:X:c:b:B:d:j:Q:kxoefqThV"
+#ifdef WITH_SELINUX
+"s:"
+#endif
+#ifdef HAVE_SYS_XATTR_H
+"x"
+#endif
+;
+
+static const char *help_string =
+"Usage: gensquashfs [OPTIONS...] <squashfs-file>\n"
+"\n"
+"Possible options:\n"
+"\n"
+"  --pack-file, -F <file>      Use a `gen_init_cpio` style description file.\n"
+"                              The file format is specified below.\n"
+"                              If --pack-dir is used, input file paths are\n"
+"                              relative to the pack directory, otherwise\n"
+"                              they are relative to the directory the pack\n"
+"                              file is in.\n"
+"  --pack-dir, -D <directory>  If --pack-file is used, this is the root path\n"
+"                              relative to which to read files. If no pack\n"
+"                              file is specified, pack the contents of the\n"
+"                              given directory into a SquashFS image. The\n"
+"                              directory becomes the root of the file\n"
+"                              system.\n"
+"\n"
+"  --compressor, -c <name>     Select the compressor to use.\n"
+"                              A list of available compressors is below.\n"
+"  --comp-extra, -X <options>  A comma separated list of extra options for\n"
+"                              the selected compressor. Specify 'help' to\n"
+"                              get a list of available options.\n"
+"  --num-jobs, -j <count>      Number of compressor jobs to create.\n"
+"  --queue-backlog, -Q <count> Maximum number of data blocks in the thread\n"
+"                              worker queue before the packer starts waiting\n"
+"                              for the block processors to catch up.\n"
+"                              Defaults to 10 times the number of jobs.\n"
+"  --block-size, -b <size>     Block size to use for Squashfs image.\n"
+"                              Defaults to %u.\n"
+"  --dev-block-size, -B <size> Device block size to padd the image to.\n"
+"                              Defaults to %u.\n"
+"  --defaults, -d <options>    A comma separated list of default values for\n"
+"                              implicitly created directories.\n"
+"\n"
+"                              Possible options:\n"
+"                                 uid=<value>    0 if not set.\n"
+"                                 gid=<value>    0 if not set.\n"
+"                                 mode=<value>   0755 if not set.\n"
+"                                 mtime=<value>  0 if not set.\n"
+"\n"
+#ifdef WITH_SELINUX
+"  --selinux, -s <file>        Specify an SELinux label file to get context\n"
+"                              attributes from.\n"
+#endif
+"  --keep-time, -k             When using --pack-dir only, use the timestamps\n"
+"                              from the input files instead of setting\n"
+"                              defaults on all input paths.\n"
+"  --keep-xattr, -x            When using --pack-dir only, read and pack the\n"
+"                              extended attributes from the input files.\n"
+"  --one-file-system, -o       When using --pack-dir only, stay in local file\n"
+"                              system and do not cross mount points.\n"
+"  --exportable, -e            Generate an export table for NFS support.\n"
+"  --no-tail-packing, -T       Do not perform tail end packing on files that\n"
+"                              are larger than block size.\n"
+"  --force, -f                 Overwrite the output file if it exists.\n"
+"  --quiet, -q                 Do not print out progress reports.\n"
+"  --help, -h                  Print help text and exit.\n"
+"  --version, -V               Print version information and exit.\n"
+"\n";
+
+const char *help_details =
+"When using the pack file option, the given file is expected to contain\n"
+"newline separated entries that describe the files to be included in the\n"
+"SquashFS image. The following entry types can be specified:\n"
+"\n"
+"# a comment\n"
+"file <path> <mode> <uid> <gid> [<location>]\n"
+"dir <path> <mode> <uid> <gid>\n"
+"nod <path> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
+"slink <path> <mode> <uid> <gid> <target>\n"
+"link <path> <dummy> <dummy> <dummy> <target>\n"
+"pipe <path> <mode> <uid> <gid>\n"
+"sock <path> <mode> <uid> <gid>\n"
+"\n"
+"<path>       Absolute path of the entry in the image. Can be put in quotes\n"
+"             if some components contain spaces.\n"
+"<location>   If given, location of the input file. Either absolute or relative\n"
+"             to the description file. If omitted, the image path is used,\n"
+"             relative to the description file.\n"
+"<target>     Symlink or hardlink target.\n"
+"<mode>       Mode/permissions of the entry.\n"
+"<uid>        Numeric user id.\n"
+"<gid>        Numeric group id.\n"
+"<dev_type>   Device type (b=block, c=character).\n"
+"<maj>        Major number of a device special file.\n"
+"<min>        Minor number of a device special file.\n"
+"\n"
+"Example:\n"
+"    # A simple squashfs image\n"
+"    dir /dev 0755 0 0\n"
+"    nod /dev/console 0600 0 0 c 5 1\n"
+"    dir /root 0700 0 0\n"
+"    dir /sbin 0755 0 0\n"
+"    \n"
+"    # Add a file. Input is relative to listing or pack dir.\n"
+"    file /sbin/init 0755 0 0 ../init/sbin/init\n"
+"    \n"
+"    # Read bin/bash, relative to listing or pack dir.\n"
+"    # Implicitly create /bin.\n"
+"    file /bin/bash 0755 0 0\n"
+"    \n"
+"    # file name with a space in it.\n"
+"    file \"/opt/my app/\\\"special\\\"/data\" 0600 0 0\n"
+"\n\n";
+
+void process_command_line(options_t *opt, int argc, char **argv)
+{
+	bool have_compressor;
+	int i, ret;
+
+	memset(opt, 0, sizeof(*opt));
+	sqfs_writer_cfg_init(&opt->cfg);
+
+	for (;;) {
+		i = getopt_long(argc, argv, short_opts, long_opts, NULL);
+		if (i == -1)
+			break;
+
+		switch (i) {
+		case 'T':
+			opt->no_tail_packing = true;
+			break;
+		case 'c':
+			have_compressor = true;
+			ret = sqfs_compressor_id_from_name(optarg);
+
+			if (ret < 0) {
+				have_compressor = false;
+#ifdef WITH_LZO
+				if (opt->cfg.comp_id == SQFS_COMP_LZO)
+					have_compressor = true;
+#endif
+			}
+
+			if (!have_compressor) {
+				fprintf(stderr, "Unsupported compressor '%s'\n",
+					optarg);
+				exit(EXIT_FAILURE);
+			}
+
+			opt->cfg.comp_id = ret;
+			break;
+		case 'b':
+			if (parse_size("Block size", &opt->cfg.block_size,
+				       optarg, 0)) {
+				exit(EXIT_FAILURE);
+			}
+			break;
+		case 'j':
+			opt->cfg.num_jobs = strtol(optarg, NULL, 0);
+			break;
+		case 'Q':
+			opt->cfg.max_backlog = strtol(optarg, NULL, 0);
+			break;
+		case 'B':
+			if (parse_size("Device block size",
+				       &opt->cfg.devblksize, optarg, 0)) {
+				exit(EXIT_FAILURE);
+			}
+			if (opt->cfg.devblksize < 1024) {
+				fputs("Device block size must be at "
+				      "least 1024\n", stderr);
+				exit(EXIT_FAILURE);
+			}
+			break;
+		case 'd':
+			opt->cfg.fs_defaults = optarg;
+			break;
+		case 'k':
+			opt->dirscan_flags |= DIR_SCAN_KEEP_TIME;
+			break;
+#ifdef HAVE_SYS_XATTR_H
+		case 'x':
+			opt->dirscan_flags |= DIR_SCAN_READ_XATTR;
+			break;
+#endif
+		case 'o':
+			opt->dirscan_flags |= DIR_SCAN_ONE_FILESYSTEM;
+			break;
+		case 'e':
+			opt->cfg.exportable = true;
+			break;
+		case 'f':
+			opt->cfg.outmode |= SQFS_FILE_OPEN_OVERWRITE;
+			break;
+		case 'q':
+			opt->cfg.quiet = true;
+			break;
+		case 'X':
+			opt->cfg.comp_extra = optarg;
+			break;
+		case 'F':
+			opt->infile = optarg;
+			break;
+		case 'D':
+			opt->packdir = optarg;
+			break;
+#ifdef WITH_SELINUX
+		case 's':
+			opt->selinux = optarg;
+			break;
+#endif
+		case 'h':
+			printf(help_string,
+			       SQFS_DEFAULT_BLOCK_SIZE, SQFS_DEVBLK_SIZE);
+			fputs(help_details, stdout);
+			compressor_print_available();
+			exit(EXIT_SUCCESS);
+		case 'V':
+			print_version("gensquashfs");
+			exit(EXIT_SUCCESS);
+		default:
+			goto fail_arg;
+		}
+	}
+
+	if (opt->cfg.num_jobs < 1)
+		opt->cfg.num_jobs = 1;
+
+	if (opt->cfg.max_backlog < 1)
+		opt->cfg.max_backlog = 10 * opt->cfg.num_jobs;
+
+	if (opt->cfg.comp_extra != NULL &&
+	    strcmp(opt->cfg.comp_extra, "help") == 0) {
+		compressor_print_help(opt->cfg.comp_id);
+		exit(EXIT_SUCCESS);
+	}
+
+	if (opt->infile == NULL && opt->packdir == NULL) {
+		fputs("No input file or directory specified.\n", stderr);
+		goto fail_arg;
+	}
+
+	if (optind >= argc) {
+		fputs("No output file specified.\n", stderr);
+		goto fail_arg;
+	}
+
+	opt->cfg.filename = argv[optind++];
+	return;
+fail_arg:
+	fputs("Try `gensquashfs --help' for more information.\n", stderr);
+	exit(EXIT_FAILURE);
+}
diff --git a/bin/gensquashfs/selinux.c b/bin/gensquashfs/selinux.c
new file mode 100644
index 0000000..678723b
--- /dev/null
+++ b/bin/gensquashfs/selinux.c
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * selinux.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "mkfs.h"
+
+#define XATTR_NAME_SELINUX "security.selinux"
+#define XATTR_VALUE_SELINUX "system_u:object_r:unlabeled_t:s0"
+
+#ifdef WITH_SELINUX
+int selinux_relable_node(void *sehnd, sqfs_xattr_writer_t *xwr,
+			 tree_node_t *node, const char *path)
+{
+	char *context = NULL;
+	int ret;
+
+	if (selabel_lookup(sehnd, &context, path, node->mode) < 0) {
+		context = strdup(XATTR_VALUE_SELINUX);
+		if (context == NULL)
+			goto fail;
+	}
+
+	ret = sqfs_xattr_writer_add(xwr, XATTR_NAME_SELINUX,
+				    context, strlen(context));
+	free(context);
+
+	if (ret)
+		sqfs_perror(node->name, "storing SELinux xattr", ret);
+
+	return ret;
+fail:
+	perror("relabeling files");
+	return -1;
+}
+
+void *selinux_open_context_file(const char *filename)
+{
+	struct selabel_handle *sehnd;
+	struct selinux_opt seopts[] = {
+		{ SELABEL_OPT_PATH, filename },
+	};
+
+	sehnd = selabel_open(SELABEL_CTX_FILE, seopts, 1);
+	if (sehnd == NULL)
+		perror(filename);
+
+	return sehnd;
+}
+
+void selinux_close_context_file(void *sehnd)
+{
+	selabel_close(sehnd);
+}
+#else
+int selinux_relable_node(void *sehnd, sqfs_xattr_writer_t *xwr,
+			 tree_node_t *node, const char *path)
+{
+	(void)sehnd; (void)xwr; (void)node; (void)path;
+	fputs("Built without SELinux support, cannot add SELinux labels\n",
+	      stderr);
+	return -1;
+}
+
+void *selinux_open_context_file(const char *filename)
+{
+	(void)filename;
+	fputs("Built without SELinux support, cannot open contexts file\n",
+	      stderr);
+	return NULL;
+}
+
+void selinux_close_context_file(void *sehnd)
+{
+	(void)sehnd;
+}
+#endif