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Diffstat (limited to 'contrib/bind/lib/isc/bitncmp.c')
-rw-r--r-- | contrib/bind/lib/isc/bitncmp.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/contrib/bind/lib/isc/bitncmp.c b/contrib/bind/lib/isc/bitncmp.c new file mode 100644 index 0000000..473f4f7 --- /dev/null +++ b/contrib/bind/lib/isc/bitncmp.c @@ -0,0 +1,66 @@ +/* + * Copyright (c) 1996 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS + * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE + * CONSORTIUM 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 1.5 1996/11/18 09:09:48 vixie 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 = ((u_char *)l)[b]; + rb = ((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); +} |