*
* Copyright 2006 Rob Landley <rob@landley.net>
*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPL version 2, see file LICENSE in this tarball for details.
*/
+#include "libbb.h"
-#include <busybox.h>
+#if ENABLE_SELINUX
+static void mkswap_selinux_setcontext(int fd, const char *path)
+{
+ struct stat stbuf;
+
+ if (!is_selinux_enabled())
+ return;
+
+ if (fstat(fd, &stbuf) < 0)
+ bb_perror_msg_and_die("fstat failed");
+ if (S_ISREG(stbuf.st_mode)) {
+ security_context_t newcon;
+ security_context_t oldcon = NULL;
+ context_t context;
-int mkswap_main(int argc, char *argv[])
+ if (fgetfilecon(fd, &oldcon) < 0) {
+ if (errno != ENODATA)
+ goto error;
+ if (matchpathcon(path, stbuf.st_mode, &oldcon) < 0)
+ goto error;
+ }
+ context = context_new(oldcon);
+ if (!context || context_type_set(context, "swapfile_t"))
+ goto error;
+ newcon = context_str(context);
+ if (!newcon)
+ goto error;
+ /* fsetfilecon_raw is hidden */
+ if (strcmp(oldcon, newcon) != 0 && fsetfilecon(fd, newcon) < 0)
+ goto error;
+ if (ENABLE_FEATURE_CLEAN_UP) {
+ context_free(context);
+ freecon(oldcon);
+ }
+ }
+ return;
+ error:
+ bb_perror_msg_and_die("SELinux relabeling failed");
+}
+#else
+# define mkswap_selinux_setcontext(fd, path) ((void)0)
+#endif
+
+/* from Linux 2.6.23 */
+/*
+ * Magic header for a swap area. ... Note that the first
+ * kilobyte is reserved for boot loader or disk label stuff.
+ */
+struct swap_header_v1 {
+/* char bootbits[1024]; Space for disklabel etc. */
+ uint32_t version; /* second kbyte, word 0 */
+ uint32_t last_page; /* 1 */
+ uint32_t nr_badpages; /* 2 */
+ char sws_uuid[16]; /* 3,4,5,6 */
+ char sws_volume[16]; /* 7,8,9,10 */
+ uint32_t padding[117]; /* 11..127 */
+ uint32_t badpages[1]; /* 128 */
+ /* total 129 32-bit words in 2nd kilobyte */
+} FIX_ALIASING;
+
+#define NWORDS 129
+#define hdr ((struct swap_header_v1*)bb_common_bufsiz1)
+
+struct BUG_sizes {
+ char swap_header_v1_wrong[sizeof(*hdr) != (NWORDS * 4) ? -1 : 1];
+ char bufsiz1_is_too_small[COMMON_BUFSIZE < (NWORDS * 4) ? -1 : 1];
+};
+
+/* Stored without terminating NUL */
+static const char SWAPSPACE2[sizeof("SWAPSPACE2")-1] ALIGN1 = "SWAPSPACE2";
+
+int mkswap_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int mkswap_main(int argc UNUSED_PARAM, char **argv)
{
- int fd, pagesize;
+ int fd;
+ unsigned pagesize;
off_t len;
- unsigned int hdr[129];
-
- // No options supported.
+ const char *label = "";
- if (argc!=2) bb_show_usage();
+ opt_complementary = "-1"; /* at least one param */
+ /* TODO: -p PAGESZ, -U UUID */
+ getopt32(argv, "L:", &label);
+ argv += optind;
- // Figure out how big the device is and announce our intentions.
+ fd = xopen(argv[0], O_WRONLY);
- fd = xopen(argv[1],O_RDWR);
- len = fdlength(fd);
+ /* Figure out how big the device is */
+ len = get_volume_size_in_bytes(fd, argv[1], 1024, /*extend:*/ 1);
pagesize = getpagesize();
- printf("Setting up swapspace version 1, size = %ld bytes\n", (long)(len-pagesize));
+ len -= pagesize;
- // Make a header.
+ /* Announce our intentions */
+ printf("Setting up swapspace version 1, size = %"OFF_FMT"u bytes\n", len);
+ mkswap_selinux_setcontext(fd, argv[0]);
- memset(hdr, 0, 129 * sizeof(unsigned int));
- hdr[0] = 1;
- hdr[1] = (len / pagesize) - 1;
+ /* Make a header. hdr is zero-filled so far... */
+ hdr->version = 1;
+ hdr->last_page = (uoff_t)len / pagesize;
- // Write the header. Sync to disk because some kernel versions check
- // signature on disk (not in cache) during swapon.
+ if (ENABLE_FEATURE_MKSWAP_UUID) {
+ char uuid_string[32];
+ generate_uuid((void*)hdr->sws_uuid);
+ bin2hex(uuid_string, hdr->sws_uuid, 16);
+ /* f.e. UUID=dfd9c173-be52-4d27-99a5-c34c6c2ff55f */
+ printf("UUID=%.8s" "-%.4s-%.4s-%.4s-%.12s\n",
+ uuid_string,
+ uuid_string+8,
+ uuid_string+8+4,
+ uuid_string+8+4+4,
+ uuid_string+8+4+4+4
+ );
+ }
+ safe_strncpy(hdr->sws_volume, label, 16);
+ /* Write the header. Sync to disk because some kernel versions check
+ * signature on disk (not in cache) during swapon. */
xlseek(fd, 1024, SEEK_SET);
- xwrite(fd, hdr, 129 * sizeof(unsigned int));
- xlseek(fd, pagesize-10, SEEK_SET);
- xwrite(fd, "SWAPSPACE2", 10);
+ xwrite(fd, hdr, NWORDS * 4);
+ xlseek(fd, pagesize - 10, SEEK_SET);
+ xwrite(fd, SWAPSPACE2, 10);
fsync(fd);
- if (ENABLE_FEATURE_CLEAN_UP) close(fd);
+ if (ENABLE_FEATURE_CLEAN_UP)
+ close(fd);
return 0;
}