commit bc8517843581eab82e01c937b1c627ee68c24ffd
author Hungming Chen <nuccachen@google.com> Thu Aug 19 21:44:58 2021 +0800
committer Nucca Chen <nuccachen@google.com> Thu Aug 19 14:29:25 2021 +0000
tree 4e926b4442ac6fa5df7c2a3134717dc14cf6cf31
parent 73745baa380b372c3e0942d3ce22098da2574b4c

bpf: don't offload IPv4 packets with TCP port 21 (ftp) and 1723 (pptp)

Bypass the IPv4 TCP packets with port 21 (ftp) and 1723 (pptp) from
BPF offload because these packets need the netfilter conntrack helper.

Bug: 195914327
Test: manual test as the follows
1. Connect to ftp.slackware.com with port 21 in active mode.
2. Check the PORT command success.
   Command:  PORT 192,168,62,128,174,17
   Response: 200 PORT command successful.
3. Download a file.

Change-Id: I8e3b8d9323eb0e572f20c74442b55d4ee95abc2f