From fc7478103c84af437ca3bfae71a82631f770bf7e Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Fri, 30 Jun 2017 20:02:51 -0700 Subject: bpf: Adds support for setting initial cwnd Adds a new bpf_setsockopt for TCP sockets, TCP_BPF_IW, which sets the initial congestion window. This can be used when the hosts are far apart (large RTTs) and it is safe to start with a large inital cwnd. Signed-off-by: Lawrence Brakmo Signed-off-by: David S. Miller --- net/core/filter.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'net/core') diff --git a/net/core/filter.c b/net/core/filter.c index 12df52711fe8..794be0a454f5 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2732,7 +2732,23 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock, tcp_reinit_congestion_control(sk, inet_csk(sk)->icsk_ca_ops); } else { - ret = -EINVAL; + struct tcp_sock *tp = tcp_sk(sk); + + if (optlen != sizeof(int)) + return -EINVAL; + + val = *((int *)optval); + /* Only some options are supported */ + switch (optname) { + case TCP_BPF_IW: + if (val <= 0 || tp->data_segs_out > 0) + ret = -EINVAL; + else + tp->snd_cwnd = val; + break; + default: + ret = -EINVAL; + } } #else ret = -EINVAL; -- cgit