+++ /dev/null
-/*$Id: checksum.c,v 1.1 2005/12/12 18:14:22 nobunaga Exp $
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Lesser General Public
-License as published by the Free Software Foundation; either
-version 2.1 of the License, or (at your option) any later version.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-Lesser General Public License for more details.
-
-You should have received a copy of the GNU Lesser General Public
-License along with this library; if not, write to the Free Software
-Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-*/
-
-unsigned short
-in_cksum(unsigned short *addr, int len)
-{
- int nleft = len;
- int sum = 0;
- unsigned short *w = addr;
- unsigned short answer = 0;
-
- /*
- * 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) {
- sum += *w++;
- nleft -= 2;
- }
-
- /* mop up an odd byte, if necessary */
- if (nleft == 1) {
- *(unsigned char *)(&answer) = *(unsigned char *)w ;
- sum += answer;
- }
-
- /* 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);
-}