[PATCH bpf-next v2 2/3] tcp: add keepalive_time_set helper

[Dmitry Yakunin]

This is preparation for usage in bpf_setsockopt.

v2:
  - change first parameter type to struct sock (Eric Dumazet)

Signed-off-by: Dmitry Yakunin <z...@yandex-team.ru>
Acked-by: Martin KaFai Lau <ka...@fb.com>
---
 include/net/tcp.h | 18 ++++++++++++++++++
 net/ipv4/tcp.c    | 15 ++-------------
 2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/include/net/tcp.h b/include/net/tcp.h
index b681338..e0a815f 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1465,6 +1465,24 @@ static inline u32 keepalive_time_elapsed(const struct 
tcp_sock *tp)
                          tcp_jiffies32 - tp->rcv_tstamp);
 }
 
+/* val must be validated at the top level function */
+static inline void keepalive_time_set(struct sock *sk, int val)
+{
+       struct tcp_sock *tp = tcp_sk(sk);
+
+       tp->keepalive_time = val * HZ;
+       if (sock_flag(sk, SOCK_KEEPOPEN) &&
+           !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
+               u32 elapsed = keepalive_time_elapsed(tp);
+
+               if (tp->keepalive_time > elapsed)
+                       elapsed = tp->keepalive_time - elapsed;
+               else
+                       elapsed = 0;
+               inet_csk_reset_keepalive_timer(sk, elapsed);
+       }
+}
+
 static inline int tcp_fin_time(const struct sock *sk)
 {
        int fin_timeout = tcp_sk(sk)->linger2 ? : 
sock_net(sk)->ipv4.sysctl_tcp_fin_timeout;
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 9700649..a366ab7 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3003,19 +3003,8 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
        case TCP_KEEPIDLE:
                if (val < 1 || val > MAX_TCP_KEEPIDLE)
                        err = -EINVAL;
-               else {
-                       tp->keepalive_time = val * HZ;
-                       if (sock_flag(sk, SOCK_KEEPOPEN) &&
-                           !((1 << sk->sk_state) &
-                             (TCPF_CLOSE | TCPF_LISTEN))) {
-                               u32 elapsed = keepalive_time_elapsed(tp);
-                               if (tp->keepalive_time > elapsed)
-                                       elapsed = tp->keepalive_time - elapsed;
-                               else
-                                       elapsed = 0;
-                               inet_csk_reset_keepalive_timer(sk, elapsed);
-                       }
-               }
+               else
+                       keepalive_time_set(sk, val);
                break;
        case TCP_KEEPINTVL:
                if (val < 1 || val > MAX_TCP_KEEPINTVL)
-- 
2.7.4