forked from luck/tmp_suning_uos_patched
aa138efd2b
[ Upstream commit d9157f6806d1499e173770df1f1b234763de5c79 ]
Currently DSACK is regarded as a dupack, which may cause
F-RTO to incorrectly enter "loss was real" when receiving
DSACK.
Packetdrill to demonstrate:
// Enable F-RTO and TLP
0 `sysctl -q net.ipv4.tcp_frto=2`
0 `sysctl -q net.ipv4.tcp_early_retrans=3`
0 `sysctl -q net.ipv4.tcp_congestion_control=cubic`
// Establish a connection
+0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+0 bind(3, ..., ...) = 0
+0 listen(3, 1) = 0
// RTT 10ms, RTO 210ms
+.1 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7>
+0 > S. 0:0(0) ack 1 <...>
+.01 < . 1:1(0) ack 1 win 257
+0 accept(3, ..., ...) = 4
// Send 2 data segments
+0 write(4, ..., 2000) = 2000
+0 > P. 1:2001(2000) ack 1
// TLP
+.022 > P. 1001:2001(1000) ack 1
// Continue to send 8 data segments
+0 write(4, ..., 10000) = 10000
+0 > P. 2001:10001(8000) ack 1
// RTO
+.188 > . 1:1001(1000) ack 1
// The original data is acked and new data is sent(F-RTO step 2.b)
+0 < . 1:1(0) ack 2001 win 257
+0 > P. 10001:12001(2000) ack 1
// D-SACK caused by TLP is regarded as a dupack, this results in
// the incorrect judgment of "loss was real"(F-RTO step 3.a)
+.022 < . 1:1(0) ack 2001 win 257 <sack 1001:2001,nop,nop>
// Never-retransmitted data(3001:4001) are acked and
// expect to switch to open state(F-RTO step 3.b)
+0 < . 1:1(0) ack 4001 win 257
+0 %{ assert tcpi_ca_state == 0, tcpi_ca_state }%
Fixes:
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||
---|---|---|
arch | ||
block | ||
certs | ||
crypto | ||
Documentation | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
LICENSES | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.