In the 3c59x.c, e1000, and other adapter drivers, ip_summed is what is being checked for value CHECKSUM_HW when sending a packet. > -----Original Message----- > From: Jeff Garzik [mailto:jgarzik@pobox.com] > Sent: Thursday, April 03, 2003 03:47 PM > To: Dennis Cook > Cc: linux-kernel@vger.kernel.org; kernelnewbies@nl.linux.org > Subject: Re: Deactivating TCP checksumming > > > Dennis Cook wrote: > > Based on various feedback, on my RH Linux 2.4.18 kernel I tried the > > following: > > > > Set "features" bit NETIF_F_IP_CSUM set (the only feature bit set). > > In my network driver start-transmit check for "CHECKSUM_HW" in > ip_summed. > > Using a small test program, use "sendfile" to copy a file to a network > > socket FD. > > Result is none of the packets presented to my network adapter > driver have > > ip_summed set to CHECKSUM_HW, so the SW IP stack has already > > computed checksums. > > CHECKSUM_HW is for receive, not transmit. Read the comments at the top > of include/linux/skbuff.h. > > > > Is this mechanism possibly broken on kernel 2.4? > > > it works quite well. > > Jeff > > > > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
