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Diffstat (limited to 'e2fsprogs/uuid/gen_uuid.c')
| -rw-r--r-- | e2fsprogs/uuid/gen_uuid.c | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/e2fsprogs/uuid/gen_uuid.c b/e2fsprogs/uuid/gen_uuid.c new file mode 100644 index 0000000..489cdd2 --- /dev/null +++ b/e2fsprogs/uuid/gen_uuid.c @@ -0,0 +1,310 @@ +/* + * gen_uuid.c --- generate a DCE-compatible uuid + * + * Copyright (C) 1996, 1997, 1998, 1999 Theodore Ts'o. + * + * %Begin-Header% + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, and the entire permission notice in its entirety, + * including the disclaimer of warranties. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote + * products derived from this software without specific prior + * written permission. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF + * WHICH ARE HEREBY DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE + * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * %End-Header% + */ + +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif +#ifdef HAVE_STDLIB_H +#include <stdlib.h> +#endif +#include <string.h> +#include <fcntl.h> +#include <errno.h> +#include <sys/types.h> +#include <sys/time.h> +#include <sys/stat.h> +#include <sys/file.h> +#ifdef HAVE_SYS_IOCTL_H +#include <sys/ioctl.h> +#endif +#ifdef HAVE_SYS_SOCKET_H +#include <sys/socket.h> +#endif +#ifdef HAVE_SYS_SOCKIO_H +#include <sys/sockio.h> +#endif +#ifdef HAVE_NET_IF_H +#include <net/if.h> +#endif +#ifdef HAVE_NETINET_IN_H +#include <netinet/in.h> +#endif +#ifdef HAVE_NET_IF_DL_H +#include <net/if_dl.h> +#endif + +#include "uuidP.h" + +#ifdef HAVE_SRANDOM +#define srand(x) srandom(x) +#define rand() random() +#endif + +static int get_random_fd(void) +{ + struct timeval tv; + static int fd = -2; + int i; + + if (fd == -2) { + gettimeofday(&tv, 0); + fd = open("/dev/urandom", O_RDONLY); + if (fd == -1) + fd = open("/dev/random", O_RDONLY | O_NONBLOCK); + srand((getpid() << 16) ^ getuid() ^ tv.tv_sec ^ tv.tv_usec); + } + /* Crank the random number generator a few times */ + gettimeofday(&tv, 0); + for (i = (tv.tv_sec ^ tv.tv_usec) & 0x1F; i > 0; i--) + rand(); + return fd; +} + + +/* + * Generate a series of random bytes. Use /dev/urandom if possible, + * and if not, use srandom/random. + */ +static void get_random_bytes(void *buf, int nbytes) +{ + int i, n = nbytes, fd = get_random_fd(); + int lose_counter = 0; + unsigned char *cp = (unsigned char *) buf; + + if (fd >= 0) { + while (n > 0) { + i = read(fd, cp, n); + if (i <= 0) { + if (lose_counter++ > 16) + break; + continue; + } + n -= i; + cp += i; + lose_counter = 0; + } + } + + /* + * We do this all the time, but this is the only source of + * randomness if /dev/random/urandom is out to lunch. + */ + for (cp = buf, i = 0; i < nbytes; i++) + *cp++ ^= (rand() >> 7) & 0xFF; + return; +} + +/* + * Get the ethernet hardware address, if we can find it... + */ +static int get_node_id(unsigned char *node_id) +{ +#ifdef HAVE_NET_IF_H + int sd; + struct ifreq ifr, *ifrp; + struct ifconf ifc; + char buf[1024]; + int n, i; + unsigned char *a; +#ifdef HAVE_NET_IF_DL_H + struct sockaddr_dl *sdlp; +#endif + +/* + * BSD 4.4 defines the size of an ifreq to be + * max(sizeof(ifreq), sizeof(ifreq.ifr_name)+ifreq.ifr_addr.sa_len + * However, under earlier systems, sa_len isn't present, so the size is + * just sizeof(struct ifreq) + */ +#ifdef HAVE_SA_LEN +#ifndef max +#define max(a,b) ((a) > (b) ? (a) : (b)) +#endif +#define ifreq_size(i) max(sizeof(struct ifreq),\ + sizeof((i).ifr_name)+(i).ifr_addr.sa_len) +#else +#define ifreq_size(i) sizeof(struct ifreq) +#endif /* HAVE_SA_LEN*/ + + sd = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP); + if (sd < 0) { + return -1; + } + memset(buf, 0, sizeof(buf)); + ifc.ifc_len = sizeof(buf); + ifc.ifc_buf = buf; + if (ioctl (sd, SIOCGIFCONF, (char *)&ifc) < 0) { + close(sd); + return -1; + } + n = ifc.ifc_len; + for (i = 0; i < n; i+= ifreq_size(*ifrp) ) { + ifrp = (struct ifreq *)((char *) ifc.ifc_buf+i); + strncpy(ifr.ifr_name, ifrp->ifr_name, IFNAMSIZ); +#ifdef SIOCGIFHWADDR + if (ioctl(sd, SIOCGIFHWADDR, &ifr) < 0) + continue; + a = (unsigned char *) &ifr.ifr_hwaddr.sa_data; +#else +#ifdef SIOCGENADDR + if (ioctl(sd, SIOCGENADDR, &ifr) < 0) + continue; + a = (unsigned char *) ifr.ifr_enaddr; +#else +#ifdef HAVE_NET_IF_DL_H + sdlp = (struct sockaddr_dl *) &ifrp->ifr_addr; + if ((sdlp->sdl_family != AF_LINK) || (sdlp->sdl_alen != 6)) + continue; + a = (unsigned char *) &sdlp->sdl_data[sdlp->sdl_nlen]; +#else + /* + * XXX we don't have a way of getting the hardware + * address + */ + close(sd); + return 0; +#endif /* HAVE_NET_IF_DL_H */ +#endif /* SIOCGENADDR */ +#endif /* SIOCGIFHWADDR */ + if (!a[0] && !a[1] && !a[2] && !a[3] && !a[4] && !a[5]) + continue; + if (node_id) { + memcpy(node_id, a, 6); + close(sd); + return 1; + } + } + close(sd); +#endif + return 0; +} + +/* Assume that the gettimeofday() has microsecond granularity */ +#define MAX_ADJUSTMENT 10 + +static int get_clock(uint32_t *clock_high, uint32_t *clock_low, uint16_t *ret_clock_seq) +{ + static int adjustment = 0; + static struct timeval last = {0, 0}; + static uint16_t clock_seq; + struct timeval tv; + unsigned long long clock_reg; + +try_again: + gettimeofday(&tv, 0); + if ((last.tv_sec == 0) && (last.tv_usec == 0)) { + get_random_bytes(&clock_seq, sizeof(clock_seq)); + clock_seq &= 0x3FFF; + last = tv; + last.tv_sec--; + } + if ((tv.tv_sec < last.tv_sec) || + ((tv.tv_sec == last.tv_sec) && + (tv.tv_usec < last.tv_usec))) { + clock_seq = (clock_seq+1) & 0x3FFF; + adjustment = 0; + last = tv; + } else if ((tv.tv_sec == last.tv_sec) && + (tv.tv_usec == last.tv_usec)) { + if (adjustment >= MAX_ADJUSTMENT) + goto try_again; + adjustment++; + } else { + adjustment = 0; + last = tv; + } + + clock_reg = tv.tv_usec*10 + adjustment; + clock_reg += ((unsigned long long) tv.tv_sec)*10000000; + clock_reg += (((unsigned long long) 0x01B21DD2) << 32) + 0x13814000; + + *clock_high = clock_reg >> 32; + *clock_low = clock_reg; + *ret_clock_seq = clock_seq; + return 0; +} + +void uuid_generate_time(uuid_t out) +{ + static unsigned char node_id[6]; + static int has_init = 0; + struct uuid uu; + uint32_t clock_mid; + + if (!has_init) { + if (get_node_id(node_id) <= 0) { + get_random_bytes(node_id, 6); + /* + * Set multicast bit, to prevent conflicts + * with IEEE 802 addresses obtained from + * network cards + */ + node_id[0] |= 0x01; + } + has_init = 1; + } + get_clock(&clock_mid, &uu.time_low, &uu.clock_seq); + uu.clock_seq |= 0x8000; + uu.time_mid = (uint16_t) clock_mid; + uu.time_hi_and_version = ((clock_mid >> 16) & 0x0FFF) | 0x1000; + memcpy(uu.node, node_id, 6); + uuid_pack(&uu, out); +} + +void uuid_generate_random(uuid_t out) +{ + uuid_t buf; + struct uuid uu; + + get_random_bytes(buf, sizeof(buf)); + uuid_unpack(buf, &uu); + + uu.clock_seq = (uu.clock_seq & 0x3FFF) | 0x8000; + uu.time_hi_and_version = (uu.time_hi_and_version & 0x0FFF) | 0x4000; + uuid_pack(&uu, out); +} + +/* + * This is the generic front-end to uuid_generate_random and + * uuid_generate_time. It uses uuid_generate_random only if + * /dev/urandom is available, since otherwise we won't have + * high-quality randomness. + */ +void uuid_generate(uuid_t out) +{ + if (get_random_fd() >= 0) + uuid_generate_random(out); + else + uuid_generate_time(out); +} |