diff options
| author | Lawrence Brakmo <brakmo@fb.com> | 2018-01-25 16:14:14 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2018-01-25 16:41:14 -0800 |
| commit | a31ad29e6a30cb0b9084a9425b819cdcd97273ce (patch) | |
| tree | 33ed37e633027ebf8b53a289eaddc687b1756368 | |
| parent | 6f9bd3d731aac0d2ac21dd78a642af5df38fb5c5 (diff) | |
bpf: Add BPF_SOCK_OPS_RETRANS_CB
Adds support for calling sock_ops BPF program when there is a
retransmission. Three arguments are used; one for the sequence number,
another for the number of segments retransmitted, and the last one for
the return value of tcp_transmit_skb (0 => success).
Does not include syn-ack retransmissions.
New op: BPF_SOCK_OPS_RETRANS_CB.
Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | include/uapi/linux/bpf.h | 9 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 4 |
2 files changed, 12 insertions, 1 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 46520eae37fa..31c93a0bdbc2 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1005,7 +1005,8 @@ struct bpf_sock_ops { /* Definitions for bpf_sock_ops_cb_flags */ #define BPF_SOCK_OPS_RTO_CB_FLAG (1<<0) -#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x1 /* Mask of all currently +#define BPF_SOCK_OPS_RETRANS_CB_FLAG (1<<1) +#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x3 /* Mask of all currently * supported cb flags */ @@ -1047,6 +1048,12 @@ enum { * Arg2: value of icsk_rto * Arg3: whether RTO has expired */ + BPF_SOCK_OPS_RETRANS_CB, /* Called when skb is retransmitted. + * Arg1: sequence number of 1st byte + * Arg2: # segments + * Arg3: return value of + * tcp_transmit_skb (0 => success) + */ }; #define TCP_BPF_IW 1001 /* Set TCP initial congestion window */ diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index d12f7f71c1c4..e9f985e42405 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2905,6 +2905,10 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs) err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC); } + if (BPF_SOCK_OPS_TEST_FLAG(tp, BPF_SOCK_OPS_RETRANS_CB_FLAG)) + tcp_call_bpf_3arg(sk, BPF_SOCK_OPS_RETRANS_CB, + TCP_SKB_CB(skb)->seq, segs, err); + if (likely(!err)) { TCP_SKB_CB(skb)->sacked |= TCPCB_EVER_RETRANS; trace_tcp_retransmit_skb(sk, skb); |