X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Fmkswap.c;h=7e32d91edba94396543a4b03471e83dfbaca0edc;hb=4f0408b5bc6ed726e7f98d6adedede41337b9b74;hp=c4e30fd922db050441652ea4f8565f6ec05b9d8b;hpb=e1e2273076b43a4535a139de21b9ead7835f7c79;p=oweals%2Fbusybox.git diff --git a/util-linux/mkswap.c b/util-linux/mkswap.c index c4e30fd92..7e32d91ed 100644 --- a/util-linux/mkswap.c +++ b/util-linux/mkswap.c @@ -50,156 +50,87 @@ static void mkswap_selinux_setcontext(int fd, const char *path) # 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; }