* [net-next 0/1] tcp: support window clamp mid-stream
@ 2021-08-18 21:23 Neil Spring
2021-08-18 21:23 ` [net 1/1] tcp: enable mid stream window clamp Neil Spring
0 siblings, 1 reply; 2+ messages in thread
From: Neil Spring @ 2021-08-18 21:23 UTC (permalink / raw)
To: davem, edumazet
Cc: yoshfuji, dsahern, kuba, netdev, ncardwell, ycheng, Neil Spring
The TCP_WINDOW_CLAMP socket option is defined in tcp(7) to "Bound the size of
the advertised window to this value." Window clamping is distributed across two
variables, window_clamp ("Maximal window to advertise" in tcp.h) and rcv_ssthresh
("Current window clamp").
This patch updates the function where the window clamp is set to also reduce the current
window clamp, rcv_sshthresh, if needed. With this, setting the TCP_WINDOW_CLAMP option
has the documented effect of limiting the window.
Neil Spring (1):
tcp: enable mid stream window clamp
net/ipv4/tcp.c | 2 ++
1 file changed, 2 insertions(+)
--
2.30.2
^ permalink raw reply [flat|nested] 2+ messages in thread
* [net 1/1] tcp: enable mid stream window clamp
2021-08-18 21:23 [net-next 0/1] tcp: support window clamp mid-stream Neil Spring
@ 2021-08-18 21:23 ` Neil Spring
0 siblings, 0 replies; 2+ messages in thread
From: Neil Spring @ 2021-08-18 21:23 UTC (permalink / raw)
To: davem, edumazet
Cc: yoshfuji, dsahern, kuba, netdev, ncardwell, ycheng, Neil Spring
Signed-off-by: Neil Spring <ntspring@fb.com>
---
net/ipv4/tcp.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index f931def6302e..2dc6212d5888 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3338,6 +3338,8 @@ int tcp_set_window_clamp(struct sock *sk, int val)
} else {
tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
SOCK_MIN_RCVBUF / 2 : val;
+ tp->rcv_ssthresh = min(tp->rcv_ssthresh,
+ tp->window_clamp);
}
return 0;
}
--
2.30.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
end of thread, other threads:[~2021-08-18 21:23 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-18 21:23 [net-next 0/1] tcp: support window clamp mid-stream Neil Spring
2021-08-18 21:23 ` [net 1/1] tcp: enable mid stream window clamp Neil Spring
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).