*BSD News Article 26883


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From: casper@fwi.uva.nl (Casper H.S. Dik)
Newsgroups: comp.unix.bsd
Subject: Re: UDP Checksum control
Date: 3 Feb 1994 18:50:04 GMT
Organization: FWI, University of Amsterdam
Lines: 29
Distribution: world
Message-ID: <2irh0s$76p@mail.fwi.uva.nl>
References: <1994Feb3.182545.16563@nenuphar.saclay.cea.fr>
NNTP-Posting-Host: adam.fwi.uva.nl

leroy@suisse.far.cea.fr (Christophe LEROY) writes:

>Some systems use a default configuration for UDP sockets with checksum control,
>and some don't...

>I am developping a application running over SunOS, that needs checksum control,
>because it has to receive datagrams coming from another system, using 
>a very unreliable media. 

>My question is:

>How can UDP sockets checksum control be enabled on SunOS ?


You need to change the kernel:

	either edit /usr/kvm/sys/netinet/in_proto.c
	change assignment to udp_cksum from 0 to 1
	(for all kernels configured afterwards)

	or use adb:

		adb -w -k /vmunix /dev/mem
	    for next and subsequent reboot
		udp_cksum?W1
	    for current kernel:
		udp_cksum/W1	

Casper