@@ -2019,4 +2019,15 @@ static inline int tcp_call_bpf(struct sock *sk, bool is_req_sock, int op)
}
#endif
+static inline u32 tcp_timeout_init(struct sock *sk, bool is_req_sock)
+{
+ int timeout;
+
+ timeout = tcp_call_bpf(sk, is_req_sock, BPF_SOCKET_OPS_TIMEOUT_INIT);
+
+ if (timeout <= 0)
+ timeout = TCP_TIMEOUT_INIT;
+ return timeout;
+}
+
#endif /* _TCP_H */
@@ -699,6 +699,9 @@ struct bpf_socket_ops {
*/
enum {
BPF_SOCKET_OPS_VOID,
+ BPF_SOCKET_OPS_TIMEOUT_INIT, /* Should return SYN-RTO value to use or
+ * -1 if default value should be used
+ */
};
#endif /* _UAPI__LINUX_BPF_H__ */
@@ -6405,7 +6405,8 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
} else {
tcp_rsk(req)->tfo_listener = false;
if (!want_cookie)
- inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
+ inet_csk_reqsk_queue_hash_add(sk, req,
+ tcp_timeout_init((struct sock *)req, true));
af_ops->send_synack(sk, dst, &fl, req, &foc,
!want_cookie ? TCP_SYNACK_NORMAL :
TCP_SYNACK_COOKIE);
@@ -3326,7 +3326,7 @@ static void tcp_connect_init(struct sock *sk)
tp->rcv_wup = tp->rcv_nxt;
tp->copied_seq = tp->rcv_nxt;
- inet_csk(sk)->icsk_rto = TCP_TIMEOUT_INIT;
+ inet_csk(sk)->icsk_rto = tcp_timeout_init(sk, false);
inet_csk(sk)->icsk_retransmits = 0;
tcp_clear_retrans(tp);
}
This patch adds support for setting a per connection SYN and SYN_ACK RTOs from within a BPF_SOCKET_OPS program. For example, to set small RTOs when it is known both hosts are within a datacenter. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> --- include/net/tcp.h | 11 +++++++++++ include/uapi/linux/bpf.h | 3 +++ net/ipv4/tcp_input.c | 3 ++- net/ipv4/tcp_output.c | 2 +- 4 files changed, 17 insertions(+), 2 deletions(-)