path: root/mkfs/options.c

/* SPDX-License-Identifier: GPL-3.0-or-later */
#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' },
	{ "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' },
};

#ifdef WITH_SELINUX
static const char *short_opts = "s:F:D:X:c:b:B:d:fqhV";
#else
static const char *short_opts = "F:D:X:c:b:B:d:fqhV";
#endif

enum {
	DEF_UID = 0,
	DEF_GID,
	DEF_MODE,
	DEF_MTIME,
};

static const char *defaults[] = {
	[DEF_UID] = "uid",
	[DEF_GID] = "gid",
	[DEF_MODE] = "mode",
	[DEF_MTIME] = "mtime",
	NULL
};

extern char *__progname;

static const char *help_string =
"Usage: %s [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"
"                              Defaults to 'xz'.\n"
"  --comp-extra, -X <options>  A comma seperated list of extra options for\n"
"                              the selected compressor. Specify 'help' to\n"
"                              get a list of available options.\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 seperated 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
"  --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"
"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"
"pipe <path> <mode> <uid> <gid>\n"
"sock <path> <mode> <uid> <gid>\n"
"\n"
"<path>       Absolute path of the entry in the image.\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 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";

static const char *compressors[] = {
	[SQFS_COMP_GZIP] = "gzip",
	[SQFS_COMP_LZMA] = "lzma",
	[SQFS_COMP_LZO] = "lzo",
	[SQFS_COMP_XZ] = "xz",
	[SQFS_COMP_LZ4] = "lz4",
	[SQFS_COMP_ZSTD] = "zstd",
};

static long read_number(const char *name, const char *str, long min, long max)
{
	long base = 10, result = 0;
	int x;

	if (str[0] == '0') {
		if (str[1] == 'x' || str[1] == 'X') {
			base = 16;
			str += 2;
		} else {
			base = 8;
		}
	}

	if (!isxdigit(*str))
		goto fail_num;

	while (isxdigit(*str)) {
		x = *(str++);

		if (isupper(x)) {
			x = x - 'A' + 10;
		} else if (islower(x)) {
			x = x - 'a' + 10;
		} else {
			x -= '0';
		}

		if (x >= base)
			goto fail_num;

		if (result > (LONG_MAX - x) / base)
			goto fail_ov;

		result = result * base + x;
	}

	if (result < min)
		goto fail_uf;

	if (result > max)
		goto fail_ov;

	return result;
fail_num:
	fprintf(stderr, "%s: expected numeric value > 0\n", name);
	goto fail;
fail_uf:
	fprintf(stderr, "%s: number to small\n", name);
	goto fail;
fail_ov:
	fprintf(stderr, "%s: number to large\n", name);
	goto fail;
fail:
	exit(EXIT_FAILURE);
}

static void process_defaults(options_t *opt, char *subopts)
{
	char *value;
	int i;

	while (*subopts != '\0') {
		i = getsubopt(&subopts, (char *const *)defaults, &value);

		if (value == NULL) {
			fprintf(stderr, "Missing value for option %s\n",
				defaults[i]);
			exit(EXIT_FAILURE);
		}

		switch (i) {
		case DEF_UID:
			opt->def_uid = read_number("Default user ID", value,
						   0, 0xFFFFFFFF);
			break;
		case DEF_GID:
			opt->def_gid = read_number("Default group ID", value,
						   0, 0xFFFFFFFF);
			break;
		case DEF_MODE:
			opt->def_mode = read_number("Default permissions",
						    value, 0, 0xFFFFFFFF);
			break;
		case DEF_MTIME:
			opt->def_mtime = read_number("Default mtime", value,
						     0, 0xFFFFFFFF);
			break;
		default:
			fprintf(stderr, "Unknown option '%s'\n", value);
			exit(EXIT_FAILURE);
		}
	}
}

void process_command_line(options_t *opt, int argc, char **argv)
{
	bool have_compressor;
	int i;

	opt->def_uid = 0;
	opt->def_gid = 0;
	opt->def_mode = 0755;
	opt->def_mtime = 0;
	opt->outmode = O_WRONLY | O_CREAT | O_EXCL;
	opt->compressor = SQFS_COMP_XZ;
	opt->blksz = SQFS_DEFAULT_BLOCK_SIZE;
	opt->devblksz = SQFS_DEVBLK_SIZE;
	opt->quiet = false;
	opt->infile = NULL;
	opt->packdir = NULL;
	opt->outfile = NULL;
	opt->selinux = NULL;
	opt->comp_extra = NULL;

	for (;;) {
		i = getopt_long(argc, argv, short_opts, long_opts, NULL);
		if (i == -1)
			break;

		switch (i) {
		case 'c':
			have_compressor = false;

			for (i = SQFS_COMP_MIN; i <= SQFS_COMP_MAX; ++i) {
				if (strcmp(compressors[i], optarg) == 0) {
					if (compressor_exists(i)) {
						have_compressor = true;
						opt->compressor = i;
						break;
					}
				}
			}

			if (!have_compressor) {
				fprintf(stderr, "Unsupported compressor '%s'\n",
					optarg);
				exit(EXIT_FAILURE);
			}
			break;
		case 'b':
			opt->blksz = read_number("Block size", optarg,
						 4096, (1 << 20) - 1);
			break;
		case 'B':
			opt->devblksz = read_number("Device block size", optarg,
						    4096, 0xFFFFFFFF);
			break;
		case 'd':
			process_defaults(opt, optarg);
			break;
		case 'f':
			opt->outmode = O_WRONLY | O_CREAT | O_TRUNC;
			break;
		case 'q':
			opt->quiet = true;
			break;
		case 'X':
			opt->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, __progname,
			       SQFS_DEFAULT_BLOCK_SIZE, SQFS_DEVBLK_SIZE);

			fputs("Available compressors:\n", stdout);

			for (i = SQFS_COMP_MIN; i <= SQFS_COMP_MAX; ++i) {
				if (compressor_exists(i))
					printf("\t%s\n", compressors[i]);
			}

			exit(EXIT_SUCCESS);
		case 'V':
			print_version();
			exit(EXIT_SUCCESS);
		default:
			goto fail_arg;
		}
	}

	if (opt->comp_extra != NULL && strcmp(opt->comp_extra, "help") == 0) {
		compressor_print_help(opt->compressor);
		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->outfile = argv[optind++];
	return;
fail_arg:
	fprintf(stderr, "Try `%s --help' for more information.\n", __progname);
	exit(EXIT_FAILURE);
}