[PATCH bpf-next 10/11] bpf: Add BPF_SOCK_OPS_STATE_CB
From: Lawrence Brakmo <hidden>
Date: 2017-12-20 21:17:01
Subsystem:
bpf [general] (safe dynamic programs and tools), networking [general], networking [tcp], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Neal Cardwell, Linus Torvalds
Adds support for calling sock_ops BPF program when there is a TCP state change. Two arguments are used; one for the old state and another for the new state. New op: BPF_SOCK_OPS_STATE_CB. Signed-off-by: Lawrence Brakmo <redacted> --- include/uapi/linux/bpf.h | 4 ++++ include/uapi/linux/tcp.h | 1 + net/ipv4/tcp.c | 2 ++ 3 files changed, 7 insertions(+)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 415b951..14040e0 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h@@ -1024,6 +1024,10 @@ enum { * Arg1: sequence number of 1st byte * Arg2: # segments */ + BPF_SOCK_OPS_STATE_CB, /* Called when TCP changes state. + * Arg1: old_state + * Arg2: new_state + */ }; #define TCP_BPF_IW 1001 /* Set TCP initial congestion window */
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index dc36d3c..211322c 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h@@ -262,6 +262,7 @@ struct tcp_md5sig { /* Definitions for bpf_sock_ops_flags */ #define BPF_SOCK_OPS_RTO_CB_FLAG (1<<0) #define BPF_SOCK_OPS_RETRANS_CB_FLAG (1<<1) +#define BPF_SOCK_OPS_STATE_CB_FLAG (1<<2) /* INET_DIAG_MD5SIG */ struct tcp_diag_md5sig {
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 587d65c..f342f31 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c@@ -2041,6 +2041,8 @@ void tcp_set_state(struct sock *sk, int state) int oldstate = sk->sk_state; trace_tcp_set_state(sk, oldstate, state); + if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_STATE_CB_FLAG)) + tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_STATE_CB, oldstate, state); switch (state) { case TCP_ESTABLISHED:
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2.9.5