diff options
Diffstat (limited to 'contrib/bind9/lib/isc/random.c')
| -rw-r--r-- | contrib/bind9/lib/isc/random.c | 27 |
1 files changed, 18 insertions, 9 deletions
diff --git a/contrib/bind9/lib/isc/random.c b/contrib/bind9/lib/isc/random.c index 0329abd..84ba6a0 100644 --- a/contrib/bind9/lib/isc/random.c +++ b/contrib/bind9/lib/isc/random.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") + * Copyright (C) 2004, 2005, 2007, 2009 Internet Systems Consortium, Inc. ("ISC") * Copyright (C) 1999-2003 Internet Software Consortium. * * Permission to use, copy, modify, and/or distribute this software for any @@ -15,7 +15,7 @@ * PERFORMANCE OF THIS SOFTWARE. */ -/* $Id: random.c,v 1.25 2007/06/19 23:47:17 tbox Exp $ */ +/* $Id: random.c,v 1.25.332.2 2009/07/16 23:47:17 tbox Exp $ */ /*! \file */ @@ -43,7 +43,7 @@ initialize_rand(void) { #ifndef HAVE_ARC4RANDOM unsigned int pid = getpid(); - + /* * The low bits of pid generally change faster. * Xor them with the high bits of time which change slowly. @@ -84,7 +84,16 @@ isc_random_get(isc_uint32_t *val) * rand()'s lower bits are not random. * rand()'s upper bit is zero. */ +#if RAND_MAX >= 0xfffff + /* We have at least 20 bits. Use lower 16 excluding lower most 4 */ *val = ((rand() >> 4) & 0xffff) | ((rand() << 12) & 0xffff0000); +#elif RAND_MAX >= 0x7fff + /* We have at least 15 bits. Use lower 10/11 excluding lower most 4 */ + *val = ((rand() >> 4) & 0x000007ff) | ((rand() << 7) & 0x003ff800) | + ((rand() << 18) & 0xffc00000); +#else +#error RAND_MAX is too small +#endif #else *val = arc4random(); #endif @@ -92,13 +101,13 @@ isc_random_get(isc_uint32_t *val) isc_uint32_t isc_random_jitter(isc_uint32_t max, isc_uint32_t jitter) { + isc_uint32_t rnd; + REQUIRE(jitter < max); + if (jitter == 0) return (max); - else -#ifndef HAVE_ARC4RANDOM - return (max - rand() % jitter); -#else - return (max - arc4random() % jitter); -#endif + + isc_random_get(&rnd); + return (max - rnd % jitter); } |
