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Diffstat (limited to 'lib/bind/isc/bitncmp.c')
-rw-r--r-- | lib/bind/isc/bitncmp.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/lib/bind/isc/bitncmp.c b/lib/bind/isc/bitncmp.c new file mode 100644 index 0000000..8764db1 --- /dev/null +++ b/lib/bind/isc/bitncmp.c @@ -0,0 +1,68 @@ +/* + * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") + * Copyright (c) 1996,1999 by Internet Software Consortium. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT + * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#if defined(LIBC_SCCS) && !defined(lint) +static const char rcsid[] = "$Id: bitncmp.c,v 1.2.18.1 2005/04/27 05:01:05 sra Exp $"; +#endif + +#include "port_before.h" + +#include <sys/types.h> + +#include <string.h> + +#include "port_after.h" + +#include <isc/misc.h> + +/*% + * int + * bitncmp(l, r, n) + * compare bit masks l and r, for n bits. + * return: + * -1, 1, or 0 in the libc tradition. + * note: + * network byte order assumed. this means 192.5.5.240/28 has + * 0x11110000 in its fourth octet. + * author: + * Paul Vixie (ISC), June 1996 + */ +int +bitncmp(const void *l, const void *r, int n) { + u_int lb, rb; + int x, b; + + b = n / 8; + x = memcmp(l, r, b); + if (x) + return (x); + + lb = ((const u_char *)l)[b]; + rb = ((const u_char *)r)[b]; + for (b = n % 8; b > 0; b--) { + if ((lb & 0x80) != (rb & 0x80)) { + if (lb & 0x80) + return (1); + return (-1); + } + lb <<= 1; + rb <<= 1; + } + return (0); +} + +/*! \file */ |