demo: add test to detect network mixing

A new test can be enabled in the demo with the option -t to perform
traceroute between every machines to verify that machines on the same
LAN but on a different re6st network don't communicate directly via
the local links, they must use their registry which act as their
border gateway.

demo/check_routes.py

+import argparse, subprocess, time
+'''
+This script logs the output of traceroute with ICMP to several machines
+passed as arguments, it is used to check if a machine from one re6st
+network contacts a machine from another re6st network via its BGP
+(its registry) and therefore internet or directly via a machine from
+its own re6st network (which is not ok).
+The log file 'traceroute.csv' follows this pattern:
+timestamp | first hop->...->last hop (destination) | ok OR error
+The script will fail traceroute while re6st initializes (~30s)
+'''
+parser = argparse.ArgumentParser()
+parser.add_argument('n', help = 'my machine name (m1,m2...)')
+parser.add_argument('a', nargs = '+', help = 'addresses to check routes to')
+args = parser.parse_args()
+me = args.n
+addrs = args.a
+
+csv = open(me + '/traceroute.csv','w')
+
+while True:
+    for add in addrs:
+        try:
+            hops = subprocess.check_output(['traceroute6', '-n', '-I',  add])
+            if '* * *' in hops:
+                break
+            hops = [ hop for hop in hops.split() if '2001' in hop ]
+            if hops:
+                #the first two occurences are verbose of traceroute
+                #that says who we want to reach, they're not hops
+                hops = '->'.join(hops[2:])
+            else:
+                break
+            csv.write('%r,%s,%s\n' % (time.time(), hops,
+                      'ok' if '2001:db8::1' in hops else 'error'))
+            csv.flush()
+            time.sleep(1)
+        except:
+            print('Traceroute failed, trying again in 10s')
+            time.sleep(10)

demo/demo

@@ -60,6 +60,8 @@ parser.add_argument('-d', '--duration', type = int,
     help = 'time of the demo execution in seconds')
 parser.add_argument('-p', '--ping', action = 'store_true',
     help = 'execute ping utility')
+parser.add_argument('-t', '--traceroute', action = 'store_true',
+    help = 'execute traceroute utility')
 args = parser.parse_args()
 
 def handler(signum, frame):
@@ -297,6 +299,23 @@ if args.ping:
         name = machine.name if machine.short[0] == 'R' else 'm' + machine.short
         machine.screen('python ping.py {} {}'.format(name, ' '.join(ips)))
 
+if args.traceroute:
+    for j, machine in enumerate(nodes):
+        ips = [
+            '2001:db8:42::1' if i == 0 else
+            '2001:db8:42:2::' if i == 2 else
+            # Only 1 address for machine2 because prefix_len = 80,+48 = 128
+            '2001:db8:42:%s::1' % i
+            for i in xrange(9)
+            if i != j] if j > 8 else ['2001:db8:43:1::1',' 2001:db8:43::1']
+        if machine.short == 'R':
+            name = 'registry'
+        elif machine.short == 'R2':
+            name = 'registry2'
+        else:
+            name = 'm' + machine.short
+        machine.screen('python check_routes.py %s %s' % (name, ' '.join(ips)))
+
 _ll = {}
 def node_by_ll(addr):
     try: