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authorLawrence Brakmo <brakmo@fb.com>2017-06-30 20:02:44 -0700
committerDavid S. Miller <davem@davemloft.net>2017-07-01 16:15:13 -0700
commit13d3b1ebe28762c79e981931a41914fae5d04386 (patch)
tree2ba5e7acc2245ff6296bc8b51e10d49559cdb928 /net/ipv4/tcp_minisocks.c
parent61bc4d8daa7af018d7ea084ea38648828a5a90d5 (diff)
download96b-common-13d3b1ebe28762c79e981931a41914fae5d04386.tar.gz
bpf: Support for setting initial receive window
This patch adds suppport for setting the initial advertized window from within a BPF_SOCK_OPS program. This can be used to support larger initial cwnd values in environments where it is known to be safe. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_minisocks.c')
-rw-r--r--net/ipv4/tcp_minisocks.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index d30ee31e94eb..0ff83c1637d8 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -351,6 +351,7 @@ void tcp_openreq_init_rwin(struct request_sock *req,
int full_space = tcp_full_space(sk_listener);
u32 window_clamp;
__u8 rcv_wscale;
+ u32 rcv_wnd;
int mss;
mss = tcp_mss_clamp(tp, dst_metric_advmss(dst));
@@ -363,6 +364,12 @@ void tcp_openreq_init_rwin(struct request_sock *req,
(req->rsk_window_clamp > full_space || req->rsk_window_clamp == 0))
req->rsk_window_clamp = full_space;
+ rcv_wnd = tcp_rwnd_init_bpf((struct sock *)req);
+ if (rcv_wnd == 0)
+ rcv_wnd = dst_metric(dst, RTAX_INITRWND);
+ else if (full_space < rcv_wnd * mss)
+ full_space = rcv_wnd * mss;
+
/* tcp_full_space because it is guaranteed to be the first packet */
tcp_select_initial_window(full_space,
mss - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0),
@@ -370,7 +377,7 @@ void tcp_openreq_init_rwin(struct request_sock *req,
&req->rsk_window_clamp,
ireq->wscale_ok,
&rcv_wscale,
- dst_metric(dst, RTAX_INITRWND));
+ rcv_wnd);
ireq->rcv_wscale = rcv_wscale;
}
EXPORT_SYMBOL(tcp_openreq_init_rwin);