bpf: Adds support for setting sndcwnd clamp

Adds a new bpf_setsockopt for TCP sockets, TCP_BPF_SNDCWND_CLAMP, which
sets the initial congestion window. It is useful to limit the sndcwnd
when the host are close to each other (small RTT).

Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Lawrence Brakmo 2017-06-30 20:02:53 -07:00 committed by David S. Miller
parent 7bc62e2854
commit 13bf96411a
2 changed files with 8 additions and 0 deletions

View File

@ -784,5 +784,6 @@ enum {
};
#define TCP_BPF_IW 1001 /* Set TCP initial congestion window */
#define TCP_BPF_SNDCWND_CLAMP 1002 /* Set sndcwnd_clamp */
#endif /* _UAPI__LINUX_BPF_H__ */

View File

@ -2746,6 +2746,13 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock,
else
tp->snd_cwnd = val;
break;
case TCP_BPF_SNDCWND_CLAMP:
if (val <= 0) {
ret = -EINVAL;
} else {
tp->snd_cwnd_clamp = val;
tp->snd_ssthresh = val;
}
default:
ret = -EINVAL;
}