/* * 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% */ #include #include #ifdef HAVE_UNISTD_H #include #endif #ifdef HAVE_STDLIB_H #include #endif #include #include #include #include #include #ifdef HAVE_SYS_TIME_H #include #endif #include #ifdef HAVE_SYS_FILE_H #include #endif #ifdef HAVE_SYS_IOCTL_H #include #endif #ifdef HAVE_SYS_SOCKET_H #include #endif #ifdef HAVE_SYS_UN_H #include #endif #ifdef HAVE_SYS_SOCKIO_H #include #endif #ifdef HAVE_NET_IF_H #include #endif #ifdef HAVE_NETINET_IN_H #include #endif #ifdef HAVE_NET_IF_DL_H #include #endif #if defined(__linux__) && defined(HAVE_SYS_SYSCALL_H) #include #endif #include "uuidP.h" #include "randutils.h" #define read_all(a,b,c) read(a,b,c) #ifdef HAVE_TLS #define THREAD_LOCAL static __thread #else #define THREAD_LOCAL static #endif /* index with UUID_VARIANT_xxx and shift 5 bits */ static unsigned char variant_bits[] = { 0x00, 0x04, 0x06, 0x07 }; /* * Get the ethernet hardware address, if we can find it... * * XXX for a windows version, probably should use GetAdaptersInfo: * http://www.codeguru.com/cpp/i-n/network/networkinformation/article.php/c5451 * commenting out get_node_id just to get gen_uuid to compile under windows * is not the right way to go! */ 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 #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); #if defined(SIOCGIFHWADDR) && !defined(__sun) 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 /* * Get clock from global sequence clock counter. * * Return -1 if the clock counter could not be opened/locked (in this case * pseudorandom value is returned in @ret_clock_seq), otherwise return 0. */ static int get_clock(uint32_t *clock_high, uint32_t *clock_low, uint16_t *ret_clock_seq, int *num) { THREAD_LOCAL int adjustment = 0; THREAD_LOCAL struct timeval last = {0, 0}; THREAD_LOCAL int state_fd = -2; THREAD_LOCAL FILE *state_f; THREAD_LOCAL uint16_t clock_seq; struct timeval tv; uint64_t clock_reg; mode_t save_umask; int len; int ret = 0; if (state_fd == -1) ret = -1; if (state_fd == -2) { save_umask = umask(0); state_fd = open(LIBUUID_CLOCK_FILE, O_RDWR|O_CREAT|O_CLOEXEC, 0660); (void) umask(save_umask); if (state_fd != -1) { state_f = fdopen(state_fd, "r+" UL_CLOEXECSTR); if (!state_f) { close(state_fd); state_fd = -1; ret = -1; } } else ret = -1; } if (state_fd >= 0) { rewind(state_f); while (flock(state_fd, LOCK_EX) < 0) { if ((errno == EAGAIN) || (errno == EINTR)) continue; fclose(state_f); close(state_fd); state_fd = -1; ret = -1; break; } } if (state_fd >= 0) { unsigned int cl; unsigned long tv1, tv2; int a; if (fscanf(state_f, "clock: %04x tv: %lu %lu adj: %d\n", &cl, &tv1, &tv2, &a) == 4) { clock_seq = cl & 0x3FFF; last.tv_sec = tv1; last.tv_usec = tv2; adjustment = a; } } if ((last.tv_sec == 0) && (last.tv_usec == 0)) { random_get_bytes(&clock_seq, sizeof(clock_seq)); clock_seq &= 0x3FFF; gettimeofday(&last, NULL); last.tv_sec--; } try_again: gettimeofday(&tv, NULL); 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 += ((uint64_t) tv.tv_sec)*10000000; clock_reg += (((uint64_t) 0x01B21DD2) << 32) + 0x13814000; if (num && (*num > 1)) { adjustment += *num - 1; last.tv_usec += adjustment / 10; adjustment = adjustment % 10; last.tv_sec += last.tv_usec / 1000000; last.tv_usec = last.tv_usec % 1000000; } if (state_fd >= 0) { rewind(state_f); len = fprintf(state_f, "clock: %04x tv: %016ld %08ld adj: %08d\n", clock_seq, (long)last.tv_sec, (long)last.tv_usec, adjustment); fflush(state_f); if (ftruncate(state_fd, len) < 0) { fprintf(state_f, " \n"); fflush(state_f); } rewind(state_f); flock(state_fd, LOCK_UN); } *clock_high = clock_reg >> 32; *clock_low = clock_reg; *ret_clock_seq = clock_seq; return ret; } static int __uuid_generate_time(uuid_t out, int *num) { static unsigned char node_id[6]; static int has_init = 0; struct uuid uu; uint32_t clock_mid; int ret; if (!has_init) { if (get_node_id(node_id) <= 0) { random_get_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; } ret = get_clock(&clock_mid, &uu.time_low, &uu.clock_seq, num); 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); return ret; } /* * Generate time-based UUID and store it to @out * * Tries to guarantee uniqueness of the generated UUIDs by obtaining them from the uuidd daemon, * or, if uuidd is not usable, by using the global clock state counter (see get_clock()). * If neither of these is possible (e.g. because of insufficient permissions), it generates * the UUID anyway, but returns -1. Otherwise, returns 0. */ static int uuid_generate_time_generic(uuid_t out) { return __uuid_generate_time(out, NULL); } /* * Generate time-based UUID and store it to @out. * * Discards return value from uuid_generate_time_generic() */ static void uuid_generate_time(uuid_t out) { (void)uuid_generate_time_generic(out); } static void __uuid_generate_random(uuid_t out, int *num) { uuid_t buf; struct uuid uu; int i, n; if (!num || !*num) n = 1; else n = *num; for (i = 0; i < n; i++) { random_get_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); out += sizeof(uuid_t); } } void uuid_generate_random(uuid_t out) { int num = 1; /* No real reason to use the daemon for random uuid's -- yet */ __uuid_generate_random(out, &num); } /* * Check whether good random source (/dev/random or /dev/urandom) * is available. */ static int have_random_source(void) { return (access("/dev/random", R_OK) == 0 || access("/dev/urandom", R_OK) == 0); } /* * 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 (have_random_source()) uuid_generate_random(out); else uuid_generate_time(out); }