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Peer-to-peer IPv6 networking, secure and near-zero-conf.
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Bug with tools/traceroute nodejs tool #149

Closed yumitsu closed 5 years ago

yumitsu commented 7 years ago

Good day. I found that traceroute tool contains two bugs. The first one sometimes appears when you're trying to traceroute a host that in 1 HOP from you:

./traceroute exit.li
exit.li has ip address fcbd:5668:fe09:43a:d838:181:6b51:ba5e
v19.0000.0000.0000.0001.*.k *:*  1ms
v19.0000.0000.0000.08e3.9jkygq92fxg3bpm7bp466gfvzg2vff5gb68uxpkg386yq8rdd5b0.k d838:0181  76ms
  62ms
  60ms
  59ms
  89ms
  63ms
  62ms
  62ms
  61ms
  61ms
  62ms
  61ms
  104ms
  79ms
  61ms
^C

Looks like it happens because of loop in tracePath function. The second one appears on reverse trace due to timeout:

./traceroute h.cjdns.ca
h.cjdns.ca has ip address fcf4:e309:14b5:5498:cafd:4f59:4b9c:7f84
v19.0000.0000.0000.0001.*.k *:*  1ms
v19.0000.0000.0020.2263.2v6dt6f841hzhq2wsqwt263w2dswkt6fz82vcyxqptk88mtp8y50.k cafd:4f59  158ms
success, trying reverse trace
v19.0000.0000.0020.2263.2v6dt6f841hzhq2wsqwt263w2dswkt6fz82vcyxqptk88mtp8y50.k  158ms
v20.0000.0000.0320.2263.cmnkylz1dx8mx3bdxku80yw20gqmg0s9nsrusdv0psnxnfhqfmu0.k f1ad:12eb  279ms
v20.0000.0000.3320.2263.4x6hj8bk81nt6udk8h3wzsc01bl2unlytbvjj4b6vnhjzz7b8nw0.k ac89:bab9  3002ms
/Users/yumitsu/Work/opensource/cjdns/tools/traceroute:110
            if (ret.nodes.length === 0) {
                         ^

TypeError: Cannot read property 'length' of undefined
    at /Users/yumitsu/Work/opensource/cjdns/tools/traceroute:110:26
    at /Users/yumitsu/Work/opensource/cjdns/tools/traceroute:49:13
    at Object.callback (/Users/yumitsu/Work/opensource/cjdns/tools/lib/Semaphore.js:7:30)
    at Socket.<anonymous> (/Users/yumitsu/Work/opensource/cjdns/tools/lib/cjdnsadmin/cjdnsadmin.js:191:17)
    at emitTwo (events.js:106:13)
    at Socket.emit (events.js:194:7)
    at UDP.onMessage [as onmessage] (dgram.js:545:8)

That happens because cjdns.RouterModule_nextHop function returns object without nodes entry when stumbled upon timeout:

{ error: 'none',
  ms: '3000',
  result: 'timeout',
  txid: '3646868479',
  from: 'v20.0000.0000.3320.2263.*.k',
  fromIP6: '*' }

I made a fix and will commit it soon.