Building an http packet in libnet(tcp packet), Please help us as soon as posible. we are stuck!
- by Hila
we are building a NAT program,we change each packet that comes from our internal subnet,
change it's source IP address by libnet functions.( catch the packet with libpcap, put it
sniff structures and build the new packet with libnet)
over TCP, the syn/ack packets are good after the change, and when a HTTP-GET request is coming, we can see by wireshark that there is an error on the checksum field..
all the other fields are exactly the same as the original packet.
Is anyone knows what can cause this problem?
the new checksum in other packets is calculated as it should be..
but in the HTTP packet it doesn't..