a-lunev opened a new pull request #5341: URL: https://github.com/apache/incubator-nuttx/pull/5341
## Summary Transformed NET_TCP_FAST_RETRANSMIT_WATERMARK option from integer to boolean (to enable / disable the TCP Fast Retransmit algorithm). According to RFC 5681 (3.2) the TCP Fast Retransmit algorithm should start if the threshold of 3 duplicate ACKs is reached. Thus the threshold should be a constant, not an integer option. ## Impact TCP ## Testing Activate emulating packet loss on Linux host: `$ sudo iptables -A INPUT -p tcp --dport 31337 -m statistic --mode random --probability 0.01 -j DROP` Build NuttX: ``` $ ./tools/configure.sh -l sim:tcpblaster $ make menuconfig (enable/disable CONFIG_NETUTILS_NETCAT_SENDFILE, enable/disable CONFIG_NET_TCP_WRITE_BUFFERS) $ make ``` Enable TUN/TAP on Linux host: ``` $ sudo setcap cap_net_admin+ep ./nuttx $ sudo ./tools/simhostroute.sh wlan0 on ``` Run netcat server on Linux host: `$ netcat -l -p 31337` Run NuttX on Linux host: ``` $ ./nuttx NuttShell (NSH) NuttX-10.2.0 nsh> ifconfig eth0 10.0.1.2 nsh> ifup eth0 ifup eth0...OK ``` Start Wireshark (or tcpdump) and capture appeared tap0 interface. Run in NuttX: ``` nsh> dd if=/dev/zero of=/tmp/test.bin count=1000 nsh> netcat LINUX_HOST_IP_ADDRESS 31337 /tmp/test.bin ``` Observe packet loss -> duplicate ACKs -> Fast Retransmit in TCP dump. Shutdown NuttX: `nsh> poweroff` Disable TUN/TAP on Linux host: `$ sudo ./tools/simhostroute.sh wlan0 off` Deactivate emulating packet loss on Linux host: `$ sudo iptables -D INPUT -p tcp --dport 31337 -m statistic --mode random --probability 0.01 -j DROP` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
