[RFC PATCH net-next v2 14/15] bpf: Adds support for setting sndcwnd clamp
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STALE3410d
From: Lawrence Brakmo <hidden>
Date: 2017-06-15 20:08:51
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted> --- include/uapi/linux/bpf.h | 1 + net/core/filter.c | 7 +++++++ 2 files changed, 8 insertions(+)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index ecb28e2..4d033eb 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h@@ -782,5 +782,6 @@ 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__ */
diff --git a/net/core/filter.c b/net/core/filter.c
index a1d9214..f484fef 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -2733,6 +2733,13 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_socket_ops_kern *, bpf_socket, 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; }
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2.9.3