# define mkswap_selinux_setcontext(fd, path) ((void)0)
#endif
-#if ENABLE_DESKTOP
-static void mkswap_generate_uuid(uint8_t *buf)
-{
- pid_t pid;
- unsigned i;
- char uuid_string[32];
-
- /* http://www.ietf.org/rfc/rfc4122.txt
- * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * | time_low |
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * | time_mid | time_hi_and_version |
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * |clk_seq__and_variant | node (0-1) |
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * | node (2-5) |
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * IOW, uuid has this layout:
- * uint32_t time_low (big endian)
- * uint16_t time_mid (big endian)
- * uint16_t time_hi_and_version (big endian)
- * version is a 4-bit field:
- * 1 Time-based version
- * 2 DCE Security version, with embedded POSIX UIDs
- * 3 Name-based version (MD5)
- * 4 Randomly generated version
- * 5 Name-based version (SHA-1)
- * uint16_t clk_seq_and_variant (big endian)
- * variant is a 3-bit field:
- * 0xx Reserved, NCS backward compatibility
- * 10x The variant specified in rfc4122
- * 110 Reserved, Microsoft backward compatibility
- * 111 Reserved for future definition
- * uint8_t node[6]
- *
- * For version 4, these bits are set/cleared:
- * time_hi_and_version & 0x0fff | 0x4000
- * clk_seq_and_variant & 0x3fff | 0x8000
- */
-
- i = open("/dev/urandom", O_RDONLY);
- if (i >= 0) {
- read(i, buf, 16);
- close(i);
- }
- /* Paranoia. /dev/urandom may be missing.
- * rand() is guaranteed to generate at least [0, 2^15) range,
- * but lowest bits in some libc are not so "random". */
- srand(monotonic_us());
- pid = getpid();
- while (1) {
- for (i = 0; i < 16; i++)
- buf[i] ^= rand() >> 5;
- if (pid == 0)
- break;
- srand(pid);
- pid = 0;
- }
-
- buf[4 + 2 ] = (buf[4 + 2 ] & 0x0f) | 0x40; /* time_hi_and_version */
- buf[4 + 2 + 2] = (buf[4 + 2 + 2] & 0x3f) | 0x80; /* clk_seq_and_variant */
-
- bin2hex(uuid_string, (void*) buf, 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
- );
-}
-#else
-# define mkswap_generate_uuid(buf) ((void)0)
-#endif
-
-#if 0 /* from Linux 2.6.23 */
+/* from Linux 2.6.23 */
/*
- * Magic header for a swap area. The first part of the union is
- * what the swap magic looks like for the old (limited to 128MB)
- * swap area format, the second part of the union adds - in the
- * old reserved area - some extra information. Note that the first
- * kilobyte is reserved for boot loader or disk label stuff...
+ * Magic header for a swap area. ... Note that the first
+ * kilobyte is reserved for boot loader or disk label stuff.
*/
-union swap_header {
- struct {
- char reserved[PAGE_SIZE - 10];
- char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */
- } magic;
- struct {
- char bootbits[1024]; /* Space for disklabel etc. */
- __u32 version; /* second kbyte, word 0 */
- __u32 last_page; /* 1 */
- __u32 nr_badpages; /* 2 */
- unsigned char sws_uuid[16]; /* 3,4,5,6 */
- unsigned char sws_volume[16]; /* 7,8,9,10 */
- __u32 padding[117]; /* 11..127 */
- __u32 badpages[1]; /* 128, total 129 32-bit words */
- } info;
-};
-#endif
+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 ((uint32_t*)(&bb_common_bufsiz1))
+#define hdr ((struct swap_header_v1*)bb_common_bufsiz1)
-struct BUG_bufsiz1_is_too_small {
- char BUG_bufsiz1_is_too_small[COMMON_BUFSIZE < (NWORDS * 4) ? -1 : 1];
+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, char **argv)
+int mkswap_main(int argc UNUSED_PARAM, char **argv)
{
- int fd, pagesize;
+ int fd;
+ unsigned pagesize;
off_t len;
+ const char *label = "";
- // No options supported.
+ opt_complementary = "-1"; /* at least one param */
+ /* TODO: -p PAGESZ, -U UUID */
+ getopt32(argv, "L:", &label);
+ argv += optind;
- if (argc != 2) bb_show_usage();
+ fd = xopen(argv[0], O_WRONLY);
- // Figure out how big the device is and announce our intentions.
-
- fd = xopen(argv[1], O_RDWR);
- /* fdlength was reported to be unreliable - use seek */
- len = xlseek(fd, 0, SEEK_END);
-#if ENABLE_SELINUX
- xlseek(fd, 0, SEEK_SET);
-#endif
+ /* 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 = %"OFF_FMT"u bytes\n",
- len - pagesize);
- mkswap_selinux_setcontext(fd, argv[1]);
-
- // Make a header. hdr is zero-filled so far...
- hdr[0] = 1;
- hdr[1] = (len / pagesize) - 1;
- mkswap_generate_uuid((void*) &hdr[3]);
+ len -= pagesize;
+
+ /* Announce our intentions */
+ printf("Setting up swapspace version 1, size = %"OFF_FMT"u bytes\n", len);
+ mkswap_selinux_setcontext(fd, argv[0]);
+
+ /* Make a header. hdr is zero-filled so far... */
+ hdr->version = 1;
+ hdr->last_page = (uoff_t)len / pagesize;
+
+ 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.
+ /* 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, 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;
}
projects / oweals / busybox.git / blobdiff