From 9872a4bde31b0b055448e9ac1f4c9ee62d978766 Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Fri, 30 Jun 2017 20:02:47 -0700 Subject: [PATCH] bpf: Add TCP connection BPF callbacks Added callbacks to BPF SOCK_OPS type program before an active connection is intialized and after a passive or active connection is established. The following patch demostrates how they can be used to set send and receive buffer sizes. Signed-off-by: Lawrence Brakmo Signed-off-by: David S. Miller --- include/uapi/linux/bpf.h | 11 +++++++++++ net/ipv4/tcp_fastopen.c | 1 + net/ipv4/tcp_input.c | 3 ++- net/ipv4/tcp_output.c | 1 + 4 files changed, 15 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index dd43b22..2405fe3 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -767,6 +767,17 @@ enum { * window (in packets) or -1 if default * value should be used */ + BPF_SOCK_OPS_TCP_CONNECT_CB, /* Calls BPF program right before an + * active connection is initialized + */ + BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB, /* Calls BPF program when an + * active connection is + * established + */ + BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB, /* Calls BPF program when a + * passive connection is + * established + */ }; #endif /* _UAPI__LINUX_BPF_H__ */ diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c index 8b1539e..ce9c7fe 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -221,6 +221,7 @@ static struct sock *tcp_fastopen_create_child(struct sock *sk, tcp_init_congestion_control(child); tcp_mtup_init(child); tcp_init_metrics(child); + tcp_call_bpf(child, BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB); tcp_init_buffer_space(child); tp->rcv_nxt = TCP_SKB_CB(skb)->seq + 1; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index bcc9665..664210e 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5571,7 +5571,7 @@ void tcp_finish_connect(struct sock *sk, struct sk_buff *skb) icsk->icsk_af_ops->rebuild_header(sk); tcp_init_metrics(sk); - + tcp_call_bpf(sk, BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB); tcp_init_congestion_control(sk); /* Prevent spurious tcp_cwnd_restart() on first data @@ -5977,6 +5977,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) } else { /* Make sure socket is routed, for correct metrics. */ icsk->icsk_af_ops->rebuild_header(sk); + tcp_call_bpf(sk, BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB); tcp_init_congestion_control(sk); tcp_mtup_init(sk); diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index ef80942..33b3e40 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3444,6 +3444,7 @@ int tcp_connect(struct sock *sk) struct sk_buff *buff; int err; + tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_CONNECT_CB); tcp_connect_init(sk); if (unlikely(tp->repair)) { -- 2.7.4