This patch provides a tcp_bpf based eBPF sample. The test
- ncat(1) as the TCP client program to connect() to a port
with the intention of triggerring SYN retransmissions: we
first install an iptables DROP rule to make sure ncat SYNs are
resent (instead of aborting instantly after a TCP RST)
- has a bpf kernel module that sends a perf-event notification for
each TCP retransmit, and also tracks the number of such notifications
sent in the global_map
The test passes when the number of event notifications intercepted
in user-space matches the value in the global_map.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
435f90a338