[linux/network] Tunnel information (#1104)

This gathers extra information on tunnel devices. Unfortunately iproute2 is a
little inconsistent as to how it prints these out, some are booleans some are
key values, but there's no way to tell them apart other than to know, so I parse
the ones I know about (from reading the source), and ignore anything else.

Note that I didn't add any ifconfig support to the tests. This is for a few
reasons:

1. the output in the tests from ifconfig is ancient, ifconfig on linux doesn't
look like that anymore, it looks like this:

```
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.1.1.2  netmask 255.255.255.0  broadcast 10.1.1.255
        inet6 2601:645:c001:56bb::2  prefixlen 64  scopeid 0x0<global>
        inet6 fe80::52e5:49ff:fe38:d761  prefixlen 64  scopeid 0x20<link>
        ether 50:e5:49:38:d7:61  txqueuelen 1000  (Ethernet)
        RX packets 203501353  bytes 98738916585 (91.9 GiB)
        RX errors 0  dropped 559  overruns 0  frame 0
        TX packets 1035989265  bytes 1458478887585 (1.3 TiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
```

And I couldn't find a machine old enough to generate the type of output in the
tests *and* have modern ip6tunnel drivers on it. So don't ask. :)

2. Only iproute2 shows the extra tunnel info anyway, so it's not really useful
to do have the interface in the ifconfig output.

Note I will backport this to Ohai 8 after this is merged.

Signed-off-by: Phil Dibowitz <phil@ipom.com>

2 files changed, 61 insertions, 1 deletions

diff --git a/lib/ohai/plugins/linux/network.rb b/lib/ohai/plugins/linux/network.rb
index 296941fb..3f1e0b4e 100644
--- a/lib/ohai/plugins/linux/network.rb
+++ b/lib/ohai/plugins/linux/network.rb
@@ -212,6 +212,31 @@ Ohai.plugin(:Network) do
         net_counters[tmp_int] = Mash.new unless net_counters[tmp_int]
       end
 
+      if line =~ /^\s+(ip6tnl|ipip)/
+        iface[tmp_int][:tunnel_info] = {}
+        words = line.split
+        words.each_with_index do |word, index|
+          case word
+          when "external"
+            iface[tmp_int][:tunnel_info][word] = true
+          when "any", "ipip6", "ip6ip6"
+            iface[tmp_int][:tunnel_info][:proto] = word
+          when "remote",
+               "local",
+               "encaplimit",
+               "hoplimit",
+               "tclass",
+               "flowlabel",
+               "addrgenmode",
+               "numtxqueues",
+               "numrxqueues",
+               "gso_max_size",
+               "gso_max_segs"
+            iface[tmp_int][:tunnel_info][word] = words[index + 1]
+          end
+        end
+      end
+
       if line =~ /(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)/
         int = on_rx ? :rx : :tx
         net_counters[tmp_int][int] = Mash.new unless net_counters[tmp_int][int]
diff --git a/spec/unit/plugins/linux/network_spec.rb b/spec/unit/plugins/linux/network_spec.rb
index b0c5ad06..a0574da0 100644
--- a/spec/unit/plugins/linux/network_spec.rb
+++ b/spec/unit/plugins/linux/network_spec.rb
@@ -234,6 +234,10 @@ EOM
        valid_lft forever preferred_lft forever
 13: fwdintf: <MULTICAST,NOARP,UP,LOWER_UP> mtu 1496 qdisc pfifo_fast state UNKNOWN group default qlen 1000
     link/ether 00:00:00:00:00:0a brd ff:ff:ff:ff:ff:ff
+14: ip6tnl0@NONE: <NOARP,UP,LOWER_UP> mtu 1452 qdisc noqueue state UNKNOWN group default qlen 1
+    link/tunnel6 :: brd ::
+    inet6 fe80::f47a:2aff:fef0:c6ef/64 scope link
+       valid_lft forever preferred_lft forever
 EOM
   end
 
@@ -294,6 +298,13 @@ EOM
     0          0        0       0       0       0
     TX: bytes  packets  errors  dropped carrier collsns
     140        2        0       1       0       0
+14: ip6tnl0@NONE: <NOARP> mtu 1452 qdisc noop state DOWN mode DEFAULT group default qlen 1
+    link/tunnel6 :: brd :: promiscuity 0
+    ip6tnl ip6ip6 remote :: local :: encaplimit 0 hoplimit 0 tclass 0x00 flowlabel 0x00000 (flowinfo 0x00000000) addrgenmode eui64 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
+    RX: bytes  packets  errors  dropped overrun mcast
+    0          0        0       0       0       0
+    TX: bytes  packets  errors  dropped carrier collsns
+    0          0        0       0       0       0
 EOM
   end
 
@@ -546,7 +557,11 @@ EOM
       end
 
       it "detects the interfaces" do
-        expect(plugin["network"]["interfaces"].keys.sort).to eq(["eth0", "eth0.11", "eth0.151", "eth0.152", "eth0.153", "eth0:5", "eth3", "foo:veth0@eth0", "fwdintf", "lo", "ovs-system", "tun0", "venet0", "venet0:0", "xapi1"])
+        if network_method == "iproute2"
+          expect(plugin["network"]["interfaces"].keys.sort).to eq(["eth0", "eth0.11", "eth0.151", "eth0.152", "eth0.153", "eth0:5", "eth3", "foo:veth0@eth0", "fwdintf", "ip6tnl0", "lo", "ovs-system", "tun0", "venet0", "venet0:0", "xapi1"])
+        else
+          expect(plugin["network"]["interfaces"].keys.sort).to eq(["eth0", "eth0.11", "eth0.151", "eth0.152", "eth0.153", "eth0:5", "eth3", "foo:veth0@eth0", "fwdintf", "lo", "ovs-system", "tun0", "venet0", "venet0:0", "xapi1"])
+        end
       end
 
       it "detects the layer one details of an ethernet interface" do
@@ -650,6 +665,26 @@ EOM
         expect(plugin["network"]["interfaces"]["eth0"]["arp"]["10.116.201.1"]).to eq("fe:ff:ff:ff:ff:ff")
       end
 
+      if network_method == "iproute2"
+        it "detects the tunnel information" do
+          expect(plugin["network"]["interfaces"]["ip6tnl0"]["tunnel_info"]).to eq(
+            {
+              "proto" => "ip6ip6",
+              "remote" => "::",
+              "local" => "::",
+              "encaplimit" => "0",
+              "hoplimit" => "0",
+              "tclass" => "0x00",
+              "flowlabel" => "0x00000",
+              "addrgenmode" => "eui64",
+              "numtxqueues" => "1",
+              "numrxqueues" => "1",
+              "gso_max_size" => "65536",
+              "gso_max_segs" => "65535",
+            }
+          )
+        end
+      end
     end
 
     describe "gathering interface counters via #{network_method}" do