Change Details

Apparently the NAT module needs to track when the TCP checksum has to be recalculated using TSO capable hardware. It used to use the lowest bit of the tcphdr.th_x2 field. This now collides with the use of this TCP header flag as AccECN (AE) bit - and clearing it disables negotiation of AccECN across a NAT device. steal the highest bit (TH_RES1) for internal ipfw use, leave TH_AE alone. adjust TH_ flag for _x2 by shift to right check and clear the _x2 bitfield properly

Apparently the NAT module needs to track when the TCP checksum has to be recalculated using TSO capable hardware. It used to use the lowest bit of the tcphdr.th_x2 field. This now collides with the use of this TCP header flag as AccECN (AE) bit - and clearing it disables negotiation of AccECN across a NAT device.

Apparently the NAT module needs to track when the TCP checksum has to be recalculated using TSO capable hardware. It used to use the lowest bit of the tcphdr.th_x2 field. This now collides with the use of this TCP header flag as AccECN (AE) bit - and clearing it disables negotiation of AccECN across a NAT device. steal the highest bit (TH_RES1) for internal ipfw use, leave TH_AE alone. adjust TH_ flag for _x2 by shift to right check and clear the _x2 bitfield properly