# socks5 proxy on smtp transport, TCP Fast Open
#
+# NOTE: ensure that TFO is fully enabled in the kernel.
+# For linux: sysctl net.ipv4.tcp_fastopen=3
+#
munge loopback
#
#
# Disable TFO blackhole-detection as we seem to be running afoul of that
sudo perl
system ("ip tcp_metrics delete 127.0.0.1");
-system ("echo 0 > /proc/sys/net/ipv4/tcp_fastopen_blackhole_timeout_sec");
+system ("[ -e /proc/sys/net/ipv4/tcp_fastopen_blackhole_timeout_sec ] && echo 0 > /proc/sys/net/ipv4/tcp_fastopen_blackhole_timeout_sec");
****
#
# TFO both clients and server, no cookie yet
millisleep 500
#
sudo perl
-system ("echo 3600 > /proc/sys/net/ipv4/tcp_fastopen_blackhole_timeout_sec");
+system ("[ -e /proc/sys/net/ipv4/tcp_fastopen_blackhole_timeout_sec ] && echo 3600 > /proc/sys/net/ipv4/tcp_fastopen_blackhole_timeout_sec");
****
#
# Ends