Read rfc793 page 15, carefully. I think you will have to recalculate the checksum. Because you are changing the destination address field. Perhaps the nat code pointed to by someone may help you find out how exactly to do it. -abhijit Amit Shah wrote : >Hi, > I have a function(in the kernel, ip_rcv_finish... before the ip >forwarding code.) that takes in packets, replaces the dest. ip:port, and >sends to that machine. (ip forwarding is enabled.) I need to recalculate >the checksum..... ip checksumming works fine(ip_fast_csum)... but, the tcp >checksum is shown as incorrect on ethereal. The packets are not delivered >to the new dest.... > >Also, what is the skb->csum, in case there is no data (e.g. for ACK or >FIN -only packets)? -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ IRC Channel: irc.openprojects.net / #kernelnewbies Web Page: http://www.kernelnewbies.org/
