http://lxr.oss.org.cn/source/lib/checksum.c 2012/7/16 Adel Kodmani <mpcadel@xxxxxxxxx>: > > > On Mon, Jul 16, 2012 at 1:30 PM, पारस <beparas@xxxxxxxxx> wrote: >> >> >> >> On Tue, Jul 10, 2012 at 11:42 AM, Adel Kodmani <mpcadel@xxxxxxxxx> wrote: >>> >>> I am writing a kernel module that actually modifies the TCP header(both >>> at sending and receiving) and I need to re-calculate the header because of >>> that. >>> I am capturing the packets using netfilter, so I have access to the whole >>> SKB, I am using Linux 2.6.35-22 >>> >>> Looking into the source code of the TCP/IP, I found this function >>> void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); >>> The comment above it says this routing computes the IPv4 TCP checksum >>> >>> Trying to use this function, I called it passing to it skb->sk and skb >>> With no success so far. >>> >>> So my question is, how do I correctly calculate the TCP checksum? I know >>> there's a psudoheader that must be created, and added to the calculation but >>> there must be a function in the kernel I can call that already does that. >>> >>> >>> Thanks in advance, >>> Adel >>> >>> _______________________________________________ >>> Kernelnewbies mailing list >>> Kernelnewbies@xxxxxxxxxxxxxxxxx >>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >>> >> I think this may be helpful to you >> http://www.thegeekstuff.com/2012/05/ip-header-checksum/ >> >> > > > Nope, what I need to calculate is the TCP checksum, not the IP checksum > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > -- Best Regards Lin _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
