Module Name:	src
Committed By:	mycroft
Date:		Tue Jan 19 21:58:41 UTC 1999

Modified Files:
	src/sys/netinet: ip_input.c tcp_input.c udp_usrreq.c
Log Message:
Don't overwrite the checksum fields when checking them.  There's no reason to
do this, and it screws up ICMP replies.
XXX The returned IP checksum and length are still wrong.