Tethering/bpf_progs/offload - replace all TC_ACT_OK with TC_ACT_PIPE
The correct return code to keep on processing any further TC
attached programs is 'TC_ACT_PIPE' and not 'TC_ACT_OK' (which
is terminal).
Without this the ipv6 tether offload program causes termination
of processing and the ipv6 clatd offload program never actually
handles any packets (while tethering is active).
This results in lack of bpf xlat64 offloading for tethered ipv4
traffic on an ipv6-only (cellular) network.
This in turn means incoming TCP packets get GRO'ed, do not get
bpf offloaded, and get delivered to the clat daemon, which
due to them being bigger than the mtu (due to gro) cannot
handle them and discards them.
This results in poor performance, since tcp falls back to 1 mss/mtu
sized packet per rtt.
Tested via tethering a linux laptop on an ipv6-only cellular connection
and downloading the linux kernel from kernel.org via 'wget -6' and 'wget -4'.
Before:
IPv6: over 2MB/s, observed:
5805 packets, including 4 sackOK
IPv4: under 1MB/s, observed:
9300 packets, including 8 sackOK, 387 sack 1, 501 sack 2, 2310 sack 3
After:
IPv6: over 7MB/s, observed:
16702 packets, including 4 sackOK
IPv4: over 9MB/s, observed:
32755 packets, including 2 sackOK
Test: builds, TreeHugger, see above
Bug: 195624908
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I623dacb5a37dc689cea34499c3906c11fcaf946c
1 file changed