Hi Jijiang, On 12/01/2014 03:30 AM, Liu, Jijiang wrote: >> After another thought, I think that the way you proposed is a better one. >> I gives us more flexibility: >> let's say for now we'll keep both l2_len and outer_l2_len as 7 bit fields, >> and upper >> layer would have to: >> mb->l2_len = eth_hdr_in + vxlan_hdr; > > A question, how to fill the mb->l2_len for IP in IP, IP in GRE tunneling > packet that is no inner L2 header? > What is the rule? > Or you think it should be mb->l2_len = 0 + l4_tun_len; ??
We could have the following rule: - the l2_len starts after the end of outer_l2_len + outer_l3_len (if they are not 0) - l2_len is the length of all headers up to the first ip or ipv6 header Examples: Ether/IP/UDP/xxx m->outer_l2_len = 0 m->outer_l3_len = 0 m->l2_len = sizeof(ether) m->l3_len = sizeof(ip) m->l4_len = sizeof(udp) Ether/IP/IP/UDP/xxx m->outer_l2_len = sizeof(ether) m->outer_l3_len = sizeof(ip) m->l2_len = 0 m->l3_len = sizeof(ip) m->l4_len = sizeof(udp) Ether/IP/GRE/IP/UDP/xxx m->outer_l2_len = sizeof(ether) m->outer_l3_len = sizeof(ip) m->l2_len = sizeof(gre) m->l3_len = sizeof(ip) m->l4_len = sizeof(udp) Ether/IP/UDP/vxlan/Ether/IP/UDP/xxx m->outer_l2_len = sizeof(ether) m->outer_l3_len = sizeof(ip) m->l2_len = sizeof(udp) + sizeof(vxlan) + sizeof(ether) m->l3_len = sizeof(ip) m->l4_len = sizeof(udp) Regards, Olivier