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Diffstat (limited to 'freebsd/sbin/ping/utils.c')
| -rw-r--r-- | freebsd/sbin/ping/utils.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/freebsd/sbin/ping/utils.c b/freebsd/sbin/ping/utils.c new file mode 100644 index 00000000..3e0fe2b1 --- /dev/null +++ b/freebsd/sbin/ping/utils.c @@ -0,0 +1,100 @@ +#include <machine/rtems-bsd-user-space.h> + +/*- + * SPDX-License-Identifier: BSD-3-Clause + * + * Copyright (c) 1989, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Mike Muuss. + * + * 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, this list of conditions and the following disclaimer. + * 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. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS 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 ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#if 0 +#ifndef lint +static const char copyright[] = +"@(#) Copyright (c) 1989, 1993\n\ + The Regents of the University of California. All rights reserved.\n"; +#endif /* not lint */ + +#ifndef lint +static char sccsid[] = "@(#)ping.c 8.1 (Berkeley) 6/5/93"; +#endif /* not lint */ +#endif +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <string.h> + +#include "utils.h" + +/* + * in_cksum -- + * Checksum routine for Internet Protocol family headers (C Version) + */ +u_short +in_cksum(u_char *addr, int len) +{ + int nleft, sum; + u_char *w; + union { + u_short us; + u_char uc[2]; + } last; + u_short answer; + + nleft = len; + sum = 0; + w = addr; + + /* + * Our algorithm is simple, using a 32 bit accumulator (sum), we add + * sequential 16 bit words to it, and at the end, fold back all the + * carry bits from the top 16 bits into the lower 16 bits. + */ + while (nleft > 1) { + u_short data; + + memcpy(&data, w, sizeof(data)); + sum += data; + w += sizeof(data); + nleft -= sizeof(data); + } + + /* mop up an odd byte, if necessary */ + if (nleft == 1) { + last.uc[0] = *w; + last.uc[1] = 0; + sum += last.us; + } + + /* add back carry outs from top 16 bits to low 16 bits */ + sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */ + sum += (sum >> 16); /* add carry */ + answer = ~sum; /* truncate to 16 bits */ + return(answer); +} |