author | Neal Cardwell <ncardwell@google.com> | |
Thu, 2 Apr 2015 00:26:46 +0000 (20:26 -0400) | ||
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
Wed, 29 Apr 2015 08:31:46 +0000 (10:31 +0200) | ||
commit | e6250f868ccc8a609c88524a785a6e0d915ad3cb | |
tree | a2bce9e1b6981ae2b6406fe0981d2d9f46b0d065 | tree | snapshot (tar.xz tar.gz zip) |
parent | 01f69adac109867f892f12057660d891b34182f6 | commit | diff |
tcp: fix FRTO undo on cumulative ACK of SACKed range
[ Upstream commit 666b805150efd62f05810ff0db08f44a2370c937 ]
On processing cumulative ACKs, the FRTO code was not checking the
SACKed bit, meaning that there could be a spurious FRTO undo on a
cumulative ACK of a previously SACKed skb.
The FRTO code should only consider a cumulative ACK to indicate that
an original/unretransmitted skb is newly ACKed if the skb was not yet
SACKed.
The effect of the spurious FRTO undo would typically be to make the
connection think that all previously-sent packets were in flight when
they really weren't, leading to a stall and an RTO.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Fixes: e33099f96d99c ("tcp: implement RFC5682 F-RTO")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 666b805150efd62f05810ff0db08f44a2370c937 ]
On processing cumulative ACKs, the FRTO code was not checking the
SACKed bit, meaning that there could be a spurious FRTO undo on a
cumulative ACK of a previously SACKed skb.
The FRTO code should only consider a cumulative ACK to indicate that
an original/unretransmitted skb is newly ACKed if the skb was not yet
SACKed.
The effect of the spurious FRTO undo would typically be to make the
connection think that all previously-sent packets were in flight when
they really weren't, leading to a stall and an RTO.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Fixes: e33099f96d99c ("tcp: implement RFC5682 F-RTO")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/ipv4/tcp_input.c | diff | blob | history |