On Mon, 24 Jan 2022 at 15:13, Maxim Mikityanskiy <maximmi@xxxxxxxxxx> wrote: > > bpf_tcp_gen_syncookie and bpf_tcp_check_syncookie expect the full length > of the TCP header (with all extensions). Fix the documentation that says > it should be sizeof(struct tcphdr). I don't understand this change, sorry. Are you referring to the fact that the check is len < sizeof(*th) instead of len != sizeof(*th)? Your commit message makes me think that the helpers will access data in the extension headers, which isn't true as far as I can tell. That would be a problem in fact, since it could be used to read memory that the verifier hasn't deemed safe. -- Lorenz Bauer | Systems Engineer 6th Floor, County Hall/The Riverside Building, SE1 7PB, UK www.cloudflare.com
