1 files changed, 544 insertions, 0 deletions

diff --git a/disk-utils/mkswap.c b/disk-utils/mkswap.c
new file mode 100644
index 0000000..28a139d
--- /dev/null
+++ b/disk-utils/mkswap.c
@@ -0,0 +1,544 @@
+/*
+ * mkswap.c - set up a linux swap device
+ *
+ * Copyright (C) 1991 Linus Torvalds
+ *               20.12.91 - time began. Got VM working yesterday by doing this by hand.
+ *
+ * Copyright (C) 1999 Jakub Jelinek <jj@ultra.linux.cz>
+ * Copyright (C) 2007-2014 Karel Zak <kzak@redhat.com>
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <sys/utsname.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <getopt.h>
+#include <assert.h>
+#ifdef HAVE_LIBSELINUX
+#include <selinux/selinux.h>
+#include <selinux/context.h>
+#endif
+
+#include "linux_version.h"
+#include "swapheader.h"
+#include "strutils.h"
+#include "nls.h"
+#include "blkdev.h"
+#include "pathnames.h"
+#include "all-io.h"
+#include "xalloc.h"
+#include "c.h"
+#include "closestream.h"
+#include "ismounted.h"
+
+#ifdef HAVE_LIBUUID
+# include <uuid.h>
+#endif
+
+#ifdef HAVE_LIBBLKID
+# include <blkid.h>
+#endif
+
+#define MIN_GOODPAGES	10
+
+#define SELINUX_SWAPFILE_TYPE	"swapfile_t"
+
+struct mkswap_control {
+	struct swap_header_v1_2	*hdr;		/* swap header */
+	void			*signature_page;/* buffer with swap header */
+
+	char			*devname;	/* device or file name */
+	struct stat		devstat;	/* stat() result */
+	int			fd;		/* swap file descriptor */
+
+	unsigned long long	npages;		/* number of pages */
+	unsigned long		nbadpages;	/* number of bad pages */
+
+	int			user_pagesize;	/* --pagesize */
+	int			pagesize;	/* final pagesize used for the header */
+
+	char			*opt_label;	/* LABEL as specified on command line */
+	unsigned char		*uuid;		/* UUID parsed by libbuuid */
+
+	unsigned int		check:1,	/* --check */
+				force:1;	/* --force */
+};
+
+static void init_signature_page(struct mkswap_control *ctl)
+{
+	const int kernel_pagesize = getpagesize();
+
+	if (ctl->user_pagesize) {
+		if (ctl->user_pagesize < 0 || !is_power_of_2(ctl->user_pagesize) ||
+		    (size_t) ctl->user_pagesize < sizeof(struct swap_header_v1_2) + 10)
+			errx(EXIT_FAILURE,
+			     _("Bad user-specified page size %u"),
+			       ctl->user_pagesize);
+		if (ctl->user_pagesize != kernel_pagesize)
+			warnx(_("Using user-specified page size %d, "
+				"instead of the system value %d"),
+				ctl->user_pagesize, kernel_pagesize);
+		ctl->pagesize = ctl->user_pagesize;
+	} else
+		ctl->pagesize = kernel_pagesize;
+
+	ctl->signature_page = xcalloc(1, ctl->pagesize);
+	ctl->hdr = (struct swap_header_v1_2 *) ctl->signature_page;
+}
+
+static void deinit_signature_page(struct mkswap_control *ctl)
+{
+	free(ctl->signature_page);
+
+	ctl->hdr = NULL;
+	ctl->signature_page = NULL;
+}
+
+static void set_signature(const struct mkswap_control *ctl)
+{
+	char *sp = (char *) ctl->signature_page;
+
+	assert(sp);
+	memcpy(sp + ctl->pagesize - SWAP_SIGNATURE_SZ, SWAP_SIGNATURE, SWAP_SIGNATURE_SZ);
+}
+
+static void set_uuid_and_label(const struct mkswap_control *ctl)
+{
+	assert(ctl);
+	assert(ctl->hdr);
+
+	/* set UUID */
+	if (ctl->uuid)
+		memcpy(ctl->hdr->uuid, ctl->uuid, sizeof(ctl->hdr->uuid));
+
+	/* set LABEL */
+	if (ctl->opt_label) {
+		xstrncpy(ctl->hdr->volume_name,
+			 ctl->opt_label, sizeof(ctl->hdr->volume_name));
+		if (strlen(ctl->opt_label) > strlen(ctl->hdr->volume_name))
+			warnx(_("Label was truncated."));
+	}
+
+	/* report results */
+	if (ctl->uuid || ctl->opt_label) {
+		if (ctl->opt_label)
+			printf("LABEL=%s, ", ctl->hdr->volume_name);
+		else
+			printf(_("no label, "));
+#ifdef HAVE_LIBUUID
+		if (ctl->uuid) {
+			char uuid_string[UUID_STR_LEN];
+			uuid_unparse(ctl->uuid, uuid_string);
+			printf("UUID=%s\n", uuid_string);
+		} else
+#endif
+			printf(_("no uuid\n"));
+	}
+}
+
+static void __attribute__((__noreturn__)) usage(void)
+{
+	FILE *out = stdout;
+	fprintf(out,
+		_("\nUsage:\n"
+		  " %s [options] device [size]\n"),
+		program_invocation_short_name);
+
+	fputs(USAGE_SEPARATOR, out);
+	fputs(_("Set up a Linux swap area.\n"), out);
+
+	fprintf(out, _(
+		"\nOptions:\n"
+		" -c, --check               check bad blocks before creating the swap area\n"
+		" -f, --force               allow swap size area be larger than device\n"
+		" -p, --pagesize SIZE       specify page size in bytes\n"
+		" -L, --label LABEL         specify label\n"
+		" -v, --swapversion NUM     specify swap-space version number\n"
+		" -U, --uuid UUID           specify the uuid to use\n"
+		));
+	printf(USAGE_HELP_OPTIONS(27));
+
+	printf(USAGE_MAN_TAIL("mkswap(8)"));
+	exit(EXIT_SUCCESS);
+}
+
+static void page_bad(struct mkswap_control *ctl, unsigned int page)
+{
+	const unsigned long max_badpages =
+		(ctl->pagesize - 1024 - 128 * sizeof(int) - 10) / sizeof(int);
+
+	if (ctl->nbadpages == max_badpages)
+		errx(EXIT_FAILURE, _("too many bad pages: %lu"), max_badpages);
+
+	ctl->hdr->badpages[ctl->nbadpages] = page;
+	ctl->nbadpages++;
+}
+
+static void check_blocks(struct mkswap_control *ctl)
+{
+	unsigned int current_page = 0;
+	int do_seek = 1;
+	char *buffer;
+
+	assert(ctl);
+	assert(ctl->fd > -1);
+
+	buffer = xmalloc(ctl->pagesize);
+	while (current_page < ctl->npages) {
+		ssize_t rc;
+
+		if (do_seek && lseek(ctl->fd, current_page * ctl->pagesize, SEEK_SET) !=
+		    current_page * ctl->pagesize)
+			errx(EXIT_FAILURE, _("seek failed in check_blocks"));
+
+		rc = read(ctl->fd, buffer, ctl->pagesize);
+		do_seek = (rc < 0 || rc != ctl->pagesize);
+		if (do_seek)
+			page_bad(ctl, current_page);
+		current_page++;
+	}
+	printf(P_("%lu bad page\n", "%lu bad pages\n", ctl->nbadpages), ctl->nbadpages);
+	free(buffer);
+}
+
+/* return size in pages */
+static unsigned long long get_size(const struct mkswap_control *ctl)
+{
+	int fd;
+	unsigned long long size;
+
+	fd = open(ctl->devname, O_RDONLY);
+	if (fd < 0)
+		err(EXIT_FAILURE, _("cannot open %s"), ctl->devname);
+	if (blkdev_get_size(fd, &size) == 0)
+		size /= ctl->pagesize;
+
+	close(fd);
+	return size;
+}
+
+#ifdef HAVE_LIBBLKID
+static blkid_probe new_prober(const struct mkswap_control *ctl)
+{
+	blkid_probe pr = blkid_new_probe();
+	if (!pr)
+		errx(EXIT_FAILURE, _("unable to alloc new libblkid probe"));
+	if (blkid_probe_set_device(pr, ctl->fd, 0, 0))
+		errx(EXIT_FAILURE, _("unable to assign device to libblkid probe"));
+	return pr;
+}
+#endif
+
+static void open_device(struct mkswap_control *ctl)
+{
+	assert(ctl);
+	assert(ctl->devname);
+
+	if (stat(ctl->devname, &ctl->devstat) < 0)
+		err(EXIT_FAILURE, _("stat of %s failed"), ctl->devname);
+	ctl->fd = open_blkdev_or_file(&ctl->devstat, ctl->devname, O_RDWR);
+	if (ctl->fd < 0)
+		err(EXIT_FAILURE, _("cannot open %s"), ctl->devname);
+	if (ctl->check && S_ISREG(ctl->devstat.st_mode)) {
+		ctl->check = 0;
+		warnx(_("warning: checking bad blocks from swap file is not supported: %s"),
+		       ctl->devname);
+	}
+}
+
+static void wipe_device(struct mkswap_control *ctl)
+{
+	char *type = NULL;
+	int zap = 1;
+#ifdef HAVE_LIBBLKID
+	blkid_probe pr = NULL;
+#endif
+	if (!ctl->force) {
+		const char *v = NULL;
+
+		if (lseek(ctl->fd, 0, SEEK_SET) != 0)
+			errx(EXIT_FAILURE, _("unable to rewind swap-device"));
+
+#ifdef HAVE_LIBBLKID
+		pr = new_prober(ctl);
+		blkid_probe_enable_partitions(pr, 1);
+		blkid_probe_enable_superblocks(pr, 0);
+
+		if (blkid_do_fullprobe(pr) == 0 &&
+		    blkid_probe_lookup_value(pr, "PTTYPE", &v, NULL) == 0 && v) {
+			type = xstrdup(v);
+			zap = 0;
+		}
+#else
+		/* don't zap if compiled without libblkid */
+		zap = 0;
+#endif
+	}
+
+	if (zap) {
+		/*
+		 * Wipe bootbits
+		 */
+		char buf[1024] = { '\0' };
+
+		if (lseek(ctl->fd, 0, SEEK_SET) != 0)
+			errx(EXIT_FAILURE, _("unable to rewind swap-device"));
+
+		if (write_all(ctl->fd, buf, sizeof(buf)))
+			errx(EXIT_FAILURE, _("unable to erase bootbits sectors"));
+#ifdef HAVE_LIBBLKID
+		/*
+		 * Wipe rest of the device
+		 */
+		if (!pr)
+			pr = new_prober(ctl);
+
+		blkid_probe_enable_superblocks(pr, 1);
+		blkid_probe_enable_partitions(pr, 0);
+		blkid_probe_set_superblocks_flags(pr, BLKID_SUBLKS_MAGIC|BLKID_SUBLKS_TYPE);
+
+		while (blkid_do_probe(pr) == 0) {
+			const char *data = NULL;
+
+			if (blkid_probe_lookup_value(pr, "TYPE", &data, NULL) == 0 && data)
+				warnx(_("%s: warning: wiping old %s signature."), ctl->devname, data);
+			blkid_do_wipe(pr, 0);
+		}
+#endif
+	} else {
+		warnx(_("%s: warning: don't erase bootbits sectors"),
+			ctl->devname);
+		if (type)
+			fprintf(stderr, _("        (%s partition table detected). "), type);
+		else
+			fprintf(stderr, _("        (compiled without libblkid). "));
+		fprintf(stderr, _("Use -f to force.\n"));
+	}
+	free(type);
+#ifdef HAVE_LIBBLKID
+	blkid_free_probe(pr);
+#endif
+}
+
+#define SIGNATURE_OFFSET	1024
+
+static void write_header_to_device(struct mkswap_control *ctl)
+{
+	assert(ctl);
+	assert(ctl->fd > -1);
+	assert(ctl->signature_page);
+
+	if (lseek(ctl->fd, SIGNATURE_OFFSET, SEEK_SET) != SIGNATURE_OFFSET)
+		errx(EXIT_FAILURE, _("unable to rewind swap-device"));
+
+	if (write_all(ctl->fd, (char *) ctl->signature_page + SIGNATURE_OFFSET,
+		      ctl->pagesize - SIGNATURE_OFFSET) == -1)
+		err(EXIT_FAILURE,
+			_("%s: unable to write signature page"),
+			ctl->devname);
+}
+
+int main(int argc, char **argv)
+{
+	struct mkswap_control ctl = { .fd = -1 };
+	int c, permMask;
+	uint64_t sz;
+	int version = SWAP_VERSION;
+	char *block_count = NULL, *strsz = NULL;
+#ifdef HAVE_LIBUUID
+	const char *opt_uuid = NULL;
+	uuid_t uuid_dat;
+#endif
+	static const struct option longopts[] = {
+		{ "check",       no_argument,       NULL, 'c' },
+		{ "force",       no_argument,       NULL, 'f' },
+		{ "pagesize",    required_argument, NULL, 'p' },
+		{ "label",       required_argument, NULL, 'L' },
+		{ "swapversion", required_argument, NULL, 'v' },
+		{ "uuid",        required_argument, NULL, 'U' },
+		{ "version",     no_argument,       NULL, 'V' },
+		{ "help",        no_argument,       NULL, 'h' },
+		{ NULL,          0, NULL, 0 }
+	};
+
+	setlocale(LC_ALL, "");
+	bindtextdomain(PACKAGE, LOCALEDIR);
+	textdomain(PACKAGE);
+	atexit(close_stdout);
+
+	while((c = getopt_long(argc, argv, "cfp:L:v:U:Vh", longopts, NULL)) != -1) {
+		switch (c) {
+		case 'c':
+			ctl.check = 1;
+			break;
+		case 'f':
+			ctl.force = 1;
+			break;
+		case 'p':
+			ctl.user_pagesize = strtou32_or_err(optarg, _("parsing page size failed"));
+			break;
+		case 'L':
+			ctl.opt_label = optarg;
+			break;
+		case 'v':
+			version = strtos32_or_err(optarg, _("parsing version number failed"));
+			if (version != SWAP_VERSION)
+				errx(EXIT_FAILURE,
+					_("swapspace version %d is not supported"), version);
+			break;
+		case 'U':
+#ifdef HAVE_LIBUUID
+			opt_uuid = optarg;
+#else
+			warnx(_("warning: ignoring -U (UUIDs are unsupported by %s)"),
+				program_invocation_short_name);
+#endif
+			break;
+		case 'V':
+			printf(UTIL_LINUX_VERSION);
+			exit(EXIT_SUCCESS);
+		case 'h':
+			usage();
+		default:
+			errtryhelp(EXIT_FAILURE);
+		}
+	}
+
+	if (optind < argc)
+		ctl.devname = argv[optind++];
+	if (optind < argc)
+		block_count = argv[optind++];
+	if (optind != argc) {
+		warnx(_("only one device argument is currently supported"));
+		errtryhelp(EXIT_FAILURE);
+	}
+
+#ifdef HAVE_LIBUUID
+	if(opt_uuid) {
+		if (uuid_parse(opt_uuid, uuid_dat) != 0)
+			errx(EXIT_FAILURE, _("error: parsing UUID failed"));
+	} else
+		uuid_generate(uuid_dat);
+	ctl.uuid = uuid_dat;
+#endif
+
+	init_signature_page(&ctl);	/* get pagesize and allocate signature page */
+
+	if (!ctl.devname) {
+		warnx(_("error: Nowhere to set up swap on?"));
+		errtryhelp(EXIT_FAILURE);
+	}
+	if (block_count) {
+		/* this silly user specified the number of blocks explicitly */
+		uint64_t blks = strtou64_or_err(block_count,
+					_("invalid block count argument"));
+		ctl.npages = blks / (ctl.pagesize / 1024);
+	}
+
+	sz = get_size(&ctl);
+	if (!ctl.npages)
+		ctl.npages = sz;
+	else if (ctl.npages > sz && !ctl.force)
+		errx(EXIT_FAILURE,
+			_("error: "
+			  "size %llu KiB is larger than device size %"PRIu64" KiB"),
+			ctl.npages * (ctl.pagesize / 1024), sz * (ctl.pagesize / 1024));
+
+	if (ctl.npages < MIN_GOODPAGES)
+		errx(EXIT_FAILURE,
+		     _("error: swap area needs to be at least %ld KiB"),
+		     (long)(MIN_GOODPAGES * ctl.pagesize / 1024));
+	if (ctl.npages > UINT32_MAX) {
+		/* true when swap is bigger than 17.59 terabytes */
+		ctl.npages = UINT32_MAX;
+		warnx(_("warning: truncating swap area to %llu KiB"),
+			ctl.npages * ctl.pagesize / 1024);
+	}
+
+	if (is_mounted(ctl.devname))
+		errx(EXIT_FAILURE, _("error: "
+			"%s is mounted; will not make swapspace"),
+			ctl.devname);
+
+	open_device(&ctl);
+	permMask = S_ISBLK(ctl.devstat.st_mode) ? 07007 : 07077;
+	if ((ctl.devstat.st_mode & permMask) != 0)
+		warnx(_("%s: insecure permissions %04o, %04o suggested."),
+			ctl.devname, ctl.devstat.st_mode & 07777,
+			~permMask & 0666);
+	if (getuid() == 0 && S_ISREG(ctl.devstat.st_mode) && ctl.devstat.st_uid != 0)
+		warnx(_("%s: insecure file owner %d, 0 (root) suggested."),
+			ctl.devname, ctl.devstat.st_uid);
+
+
+	if (ctl.check)
+		check_blocks(&ctl);
+
+	wipe_device(&ctl);
+
+	assert(ctl.hdr);
+	ctl.hdr->version = version;
+	ctl.hdr->last_page = ctl.npages - 1;
+	ctl.hdr->nr_badpages = ctl.nbadpages;
+
+	if ((ctl.npages - MIN_GOODPAGES) < ctl.nbadpages)
+		errx(EXIT_FAILURE, _("Unable to set up swap-space: unreadable"));
+
+	sz = (ctl.npages - ctl.nbadpages - 1) * ctl.pagesize;
+	strsz = size_to_human_string(SIZE_SUFFIX_SPACE | SIZE_SUFFIX_3LETTER, sz);
+
+	printf(_("Setting up swapspace version %d, size = %s (%"PRIu64" bytes)\n"),
+		version, strsz, sz);
+	free(strsz);
+
+	set_signature(&ctl);
+	set_uuid_and_label(&ctl);
+
+	write_header_to_device(&ctl);
+
+	deinit_signature_page(&ctl);
+
+#ifdef HAVE_LIBSELINUX
+	if (S_ISREG(ctl.devstat.st_mode) && is_selinux_enabled() > 0) {
+		security_context_t context_string;
+		security_context_t oldcontext;
+		context_t newcontext;
+
+		if (fgetfilecon(ctl.fd, &oldcontext) < 0) {
+			if (errno != ENODATA)
+				err(EXIT_FAILURE,
+					_("%s: unable to obtain selinux file label"),
+					ctl.devname);
+			if (matchpathcon(ctl.devname, ctl.devstat.st_mode, &oldcontext))
+				errx(EXIT_FAILURE, _("unable to matchpathcon()"));
+		}
+		if (!(newcontext = context_new(oldcontext)))
+			errx(EXIT_FAILURE, _("unable to create new selinux context"));
+		if (context_type_set(newcontext, SELINUX_SWAPFILE_TYPE))
+			errx(EXIT_FAILURE, _("couldn't compute selinux context"));
+
+		context_string = context_str(newcontext);
+
+		if (strcmp(context_string, oldcontext)!=0) {
+			if (fsetfilecon(ctl.fd, context_string) && errno != ENOTSUP)
+				err(EXIT_FAILURE, _("unable to relabel %s to %s"),
+						ctl.devname, context_string);
+		}
+		context_free(newcontext);
+		freecon(oldcontext);
+	}
+#endif
+	/*
+	 * A subsequent swapon() will fail if the signature
+	 * is not actually on disk. (This is a kernel bug.)
+	 * The fsync() in close_fd() will take care of writing.
+	 */
+	if (close_fd(ctl.fd) != 0)
+		err(EXIT_FAILURE, _("write failed"));
+	return EXIT_SUCCESS;
+}