Page MenuHomeFreeBSD

Fix TSO for TCP/IPv6

Authored by tuexen on Mar 18 2021, 7:59 PM.



The decision whether a TCP packet is sent over IPv4 or IPv6 was based on ethertype, which works correctly.
In D27926 the criteria was changed to checking if the CSUM_IP_TSO flag is set in the csum-flags and then considering it to be TCP/IPv4.

However, the TCP stack sets the flag to CSUM_TSO for IPv4 and IPv6, where CSUM_TSO is defined as CSUM_IP_TSO|CSUM_IP6_TSO.
Therefore TCP/IPv6 packets gets mis-classified as TCP/IPv4, which breaks TSO for TCP/IPv6.

This patch bases the check again on the ethertype.

This fixes the bug reported in PR254366.

Diff Detail

rG FreeBSD src repository
Automatic diff as part of commit; lint not applicable.
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

tuexen created this revision.
This revision was not accepted when it landed; it landed in state Needs Review.Mar 18 2021, 8:33 PM
This revision was automatically updated to reflect the committed changes.