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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 02:42:50 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 02:42:50 +0000 |
commit | 8cb83eee5a58b1fad74c34094ce3afb9e430b5a4 (patch) | |
tree | a9b2e7baeca1be40eb734371e3c8b11b02294497 /disk-utils/mkswap.c | |
parent | Initial commit. (diff) | |
download | util-linux-upstream.tar.xz util-linux-upstream.zip |
Adding upstream version 2.33.1.upstream/2.33.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | disk-utils/mkswap.c | 544 |
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; +} |