bpf: fix SO_MAX_PACING_RATE to support TCP internal pacing

yuchungcheng · borkmann · commit e224c390a625 · 2019-01-18T00:30:34.000+01:00
If sch_fq packet scheduler is not used, TCP can fallback to internal pacing, but this requires sk_pacing_status to be properly set. Fixes: 8c4b4c7 ("bpf: Add setsockopt helper function to bpf") Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Lawrence Brakmo <brakmo@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
diff --git a/net/core/filter.c b/net/core/filter.c
@@ -4119,6 +4119,10 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock,
 			sk->sk_sndbuf = max_t(int, val * 2, SOCK_MIN_SNDBUF);
 			break;
 		case SO_MAX_PACING_RATE: /* 32bit version */
+			if (val != ~0U)
+				cmpxchg(&sk->sk_pacing_status,
+					SK_PACING_NONE,
+					SK_PACING_NEEDED);
 			sk->sk_max_pacing_rate = (val == ~0U) ? ~0UL : val;
 			sk->sk_pacing_rate = min(sk->sk_pacing_rate,
 						 sk->sk_max_pacing_rate);
