Commit b1964b5f authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller

tcp: constify tcp_openreq_init_rwin()

Soon, listener socket wont be locked when tcp_openreq_init_rwin()
is called. We need to read socket fields once, as their value
could change under us.
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b40cf18e
...@@ -1207,7 +1207,8 @@ static inline int tcp_full_space(const struct sock *sk) ...@@ -1207,7 +1207,8 @@ static inline int tcp_full_space(const struct sock *sk)
} }
extern void tcp_openreq_init_rwin(struct request_sock *req, extern void tcp_openreq_init_rwin(struct request_sock *req,
struct sock *sk, struct dst_entry *dst); const struct sock *sk_listener,
const struct dst_entry *dst);
void tcp_enter_memory_pressure(struct sock *sk); void tcp_enter_memory_pressure(struct sock *sk);
......
...@@ -362,27 +362,35 @@ void tcp_twsk_destructor(struct sock *sk) ...@@ -362,27 +362,35 @@ void tcp_twsk_destructor(struct sock *sk)
} }
EXPORT_SYMBOL_GPL(tcp_twsk_destructor); EXPORT_SYMBOL_GPL(tcp_twsk_destructor);
/* Warning : This function is called without sk_listener being locked.
* Be sure to read socket fields once, as their value could change under us.
*/
void tcp_openreq_init_rwin(struct request_sock *req, void tcp_openreq_init_rwin(struct request_sock *req,
struct sock *sk, struct dst_entry *dst) const struct sock *sk_listener,
const struct dst_entry *dst)
{ {
struct inet_request_sock *ireq = inet_rsk(req); struct inet_request_sock *ireq = inet_rsk(req);
struct tcp_sock *tp = tcp_sk(sk); const struct tcp_sock *tp = tcp_sk(sk_listener);
__u8 rcv_wscale; u16 user_mss = READ_ONCE(tp->rx_opt.user_mss);
int full_space = tcp_full_space(sk_listener);
int mss = dst_metric_advmss(dst); int mss = dst_metric_advmss(dst);
u32 window_clamp;
__u8 rcv_wscale;
if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss) if (user_mss && user_mss < mss)
mss = tp->rx_opt.user_mss; mss = user_mss;
window_clamp = READ_ONCE(tp->window_clamp);
/* Set this up on the first call only */ /* Set this up on the first call only */
req->window_clamp = tp->window_clamp ? : dst_metric(dst, RTAX_WINDOW); req->window_clamp = window_clamp ? : dst_metric(dst, RTAX_WINDOW);
/* limit the window selection if the user enforce a smaller rx buffer */ /* limit the window selection if the user enforce a smaller rx buffer */
if (sk->sk_userlocks & SOCK_RCVBUF_LOCK && if (sk_listener->sk_userlocks & SOCK_RCVBUF_LOCK &&
(req->window_clamp > tcp_full_space(sk) || req->window_clamp == 0)) (req->window_clamp > full_space || req->window_clamp == 0))
req->window_clamp = tcp_full_space(sk); req->window_clamp = full_space;
/* tcp_full_space because it is guaranteed to be the first packet */ /* tcp_full_space because it is guaranteed to be the first packet */
tcp_select_initial_window(tcp_full_space(sk), tcp_select_initial_window(full_space,
mss - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0), mss - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0),
&req->rcv_wnd, &req->rcv_wnd,
&req->window_clamp, &req->window_clamp,
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment