New IP header checksum code supplied by Anatoli Logvinski

diff --git a/common/packet.c b/common/packet.c
index 1fc9a0bbec66e3f5466326394d968c756f8973c5..b7752e234be3ba8d0ba4e712518544ab69b33ff5 100644 (file)
--- a/common/packet.c
+++ b/common/packet.c
@@ -40,9 +40,10 @@
  * Enterprises, see ``http://www.vix.com''.
  */
 
+
 #ifndef lint
 static char copyright[] =
-"$Id: packet.c,v 1.12 1997/02/18 14:32:51 mellon Exp $ Copyright (c) 1996 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: packet.c,v 1.13 1997/03/05 06:15:00 mellon Exp $ Copyright (c) 1996 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -75,7 +76,6 @@ static u_int32_t checksum (buf, nbytes, sum)
 #endif
                sum += (u_int16_t) ntohs(*((u_int16_t *)buf)++);
        }       
-
        /* If there's a single byte left over, checksum it, too.   Network
           byte order is big-endian, so the remaining byte is the high byte. */
        if (i < nbytes) {
@@ -97,26 +97,20 @@ static u_int32_t wrapsum (sum)
 #ifdef DEBUG_CHECKSUM
        debug ("wrapsum (%x)", sum);
 #endif
-
-       while (sum > 0x10000) {
-               sum = (sum >> 16) + (sum & 0xFFFF);
-#ifdef DEBUG_CHECKSUM_VERBOSE
-               debug ("sum = %x", sum);
-#endif
-               sum += (sum >> 16);
+       while (sum >> 16) {
 #ifdef DEBUG_CHECKSUM_VERBOSE
                debug ("sum = %x", sum);
 #endif
+               sum = (sum & 0xFFFF) + (sum >> 16);
        }
-       sum = sum ^ 0xFFFF;
 #ifdef DEBUG_CHECKSUM_VERBOSE
        debug ("sum = %x", sum);
 #endif
        
 #ifdef DEBUG_CHECKSUM
-       debug ("wrapsum returns %x", htons (sum));
+       debug ("wrapsum returns %x", htons (~sum));
 #endif
-       return htons(sum);
+       return htons(~sum);
 }
 #endif /* PACKET_ASSEMBLY || PACKET_DECODING */