From 6810c771d3165e6320f991220f0c92519e6bace7 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Wed, 19 Feb 2025 16:13:31 +0800 Subject: [PATCH 1/2] bpf: Support TCP_RTO_MAX_MS for bpf_setsockopt Some applications don't want to wait for too long because the time of retransmission increases exponentially and can reach more than 10 seconds, for example. Eric implements the core logic on supporting rto max feature in the stack previously. Based on that, we can support it for BPF use. This patch reuses the same logic of TCP_RTO_MAX_MS in do_tcp_setsockopt() and do_tcp_getsockopt(). BPF program can call bpf_{set/get}sockopt() to set/get the maximum value of RTO. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250219081333.56378-2-kerneljasonxing@gmail.com --- net/core/filter.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/core/filter.c b/net/core/filter.c index 2ec162dd83c4..ffec7b4357f9 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5382,6 +5382,7 @@ static int sol_tcp_sockopt(struct sock *sk, int optname, case TCP_USER_TIMEOUT: case TCP_NOTSENT_LOWAT: case TCP_SAVE_SYN: + case TCP_RTO_MAX_MS: if (*optlen != sizeof(int)) return -EINVAL; break; From 7a93ba804847c3257a2f116b7a0c978835813333 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Wed, 19 Feb 2025 16:13:32 +0800 Subject: [PATCH 2/2] selftests/bpf: Add rto max for bpf_setsockopt test Test the TCP_RTO_MAX_MS optname in the existing setget_sockopt test. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Link: https://patch.msgid.link/20250219081333.56378-3-kerneljasonxing@gmail.com --- tools/testing/selftests/bpf/progs/bpf_tracing_net.h | 1 + tools/testing/selftests/bpf/progs/setget_sockopt.c | 1 + 2 files changed, 2 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h index 59843b430f76..eb6ed1b7b2ef 100644 --- a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h +++ b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h @@ -49,6 +49,7 @@ #define TCP_SAVED_SYN 28 #define TCP_CA_NAME_MAX 16 #define TCP_NAGLE_OFF 1 +#define TCP_RTO_MAX_MS 44 #define TCP_ECN_OK 1 #define TCP_ECN_QUEUE_CWR 2 diff --git a/tools/testing/selftests/bpf/progs/setget_sockopt.c b/tools/testing/selftests/bpf/progs/setget_sockopt.c index 6dd4318debbf..106fe430f41b 100644 --- a/tools/testing/selftests/bpf/progs/setget_sockopt.c +++ b/tools/testing/selftests/bpf/progs/setget_sockopt.c @@ -61,6 +61,7 @@ static const struct sockopt_test sol_tcp_tests[] = { { .opt = TCP_NOTSENT_LOWAT, .new = 1314, .expected = 1314, }, { .opt = TCP_BPF_SOCK_OPS_CB_FLAGS, .new = BPF_SOCK_OPS_ALL_CB_FLAGS, .expected = BPF_SOCK_OPS_ALL_CB_FLAGS, }, + { .opt = TCP_RTO_MAX_MS, .new = 2000, .expected = 2000, }, { .opt = 0, }, };