testing: what happens when server crashes and restarts

[letoams]

add a test case for this. Use dpddelay=3s and dpdtimeout=10s and dpdaction=clear on the client.

does more traffic (ping) on the client re-trigger the connection ?

[Rishabh04-02]

The tests created (on swanling server) and found successful.
Client Output - https://pastebin.com/22abZXB3
Server Output - https://pastebin.com/wH8zJ1DK

When the server is crashed the client still shows the traffic status but it vanishes once the server is restarted. After that it re-establishes the connection.

51 road #                                                                          
 52  # check traffic status after crashing server                                  
 53 road #                                                                          
 54  ipsec whack --trafficstatus                                                    
 55 006 #2: "private-or-clear#192.1.2.0/24"[1] 10.0.10.1/32=== ...192.1.2.23, type=ESP, add_time=1234567890, inBytes=336, outBytes=336, id='C=CA, ST=Ontario, L=Toronto,     O=Libreswan, OU=Test Department, CN=east.testing.libreswan.org, E=user-east@testing.libreswan.org', lease=10.0.10.1/32
 56 road #                                                                          
 57  ipsec whack --shuntstatus                                                      
 58 000 Bare Shunt list:                                                            
 59 000                                                                            
 60 road #                                                                          
 61  # check ping and traffic status                                                
 62 road #                                                                          
 63  ping -n -c 5 -I 192.1.3.209 192.1.2.23                                        
 64 PING 192.1.2.23 (192.1.2.23) from 192.1.3.209 : 56(84) bytes of data.          
 65 --- 192.1.2.23 ping statistics ---                                              
 66 5 packets transmitted, 0 received, 100% packet loss, time XXXX                 

[Rishabh04-02]

Pull request - libreswan/libreswan#263