From f89013f66d0f1a0dad44c513318efb706399a36b Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Thu, 25 Jan 2018 16:14:11 -0800 Subject: [PATCH] bpf: Add sock_ops RTO callback Adds an optional call to sock_ops BPF program based on whether the BPF_SOCK_OPS_RTO_CB_FLAG is set in bpf_sock_ops_flags. The BPF program is passed 2 arguments: icsk_retransmits and whether the RTO has expired. Signed-off-by: Lawrence Brakmo Signed-off-by: Alexei Starovoitov --- include/uapi/linux/bpf.h | 8 +++++++- net/ipv4/tcp_timer.c | 7 +++++++ 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index aa128407c44d..c8cecf9cf5bd 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -982,7 +982,8 @@ struct bpf_sock_ops { }; /* Definitions for bpf_sock_ops_cb_flags */ -#define BPF_SOCK_OPS_ALL_CB_FLAGS 0 /* Mask of all currently +#define BPF_SOCK_OPS_RTO_CB_FLAG (1<<0) +#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x1 /* Mask of all currently * supported cb flags */ @@ -1019,6 +1020,11 @@ enum { * a congestion threshold. RTTs above * this indicate congestion */ + BPF_SOCK_OPS_RTO_CB, /* Called when an RTO has triggered. + * Arg1: value of icsk_retransmits + * Arg2: value of icsk_rto + * Arg3: whether RTO has expired + */ }; #define TCP_BPF_IW 1001 /* Set TCP initial congestion window */ diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 6db3124cdbda..257abdde23b0 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -213,11 +213,18 @@ static int tcp_write_timeout(struct sock *sk) icsk->icsk_user_timeout); } tcp_fastopen_active_detect_blackhole(sk, expired); + + if (BPF_SOCK_OPS_TEST_FLAG(tp, BPF_SOCK_OPS_RTO_CB_FLAG)) + tcp_call_bpf_3arg(sk, BPF_SOCK_OPS_RTO_CB, + icsk->icsk_retransmits, + icsk->icsk_rto, (int)expired); + if (expired) { /* Has it gone just too far? */ tcp_write_err(sk); return 1; } + return 0; } -- 2.11.0