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 <brakmo@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Lawrence Brakmo 2017-06-30 20:02:47 -07:00 коммит произвёл David S. Miller
Родитель 8c4b4c7e9f
Коммит 9872a4bde3
4 изменённых файлов: 15 добавлений и 1 удалений

Просмотреть файл

@ -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__ */

Просмотреть файл

@ -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;

Просмотреть файл

@ -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);

Просмотреть файл

@ -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)) {