On Tue, Feb 11, 2014 at 03:03:42PM -0500, Guibin(Bill) Tian wrote: > Hi, > I am looking for the code in linux kernel that verifies the checksum of TCP > header and IP header for inbound packet. The packet supposes to be dropped > if the checksum doesn't match. Here is some code that checks the TCP checksum. /* * Calculate(/check) TCP checksum */ static inline __sum16 tcp_v4_check(int len, __be32 saddr, __be32 daddr, __wsum base) { return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base); } from: include/net/tcp.h also, try searching for csum_error in net/ipv4/tcp_ipv4.c _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies