expose ring parameters in the network plugin

2 files changed, 53 insertions, 1 deletions

diff --git a/lib/ohai/plugins/linux/network.rb b/lib/ohai/plugins/linux/network.rb
index 18f6dd31..edf779f2 100644
--- a/lib/ohai/plugins/linux/network.rb
+++ b/lib/ohai/plugins/linux/network.rb
@@ -171,6 +171,36 @@ Ohai.plugin(:Network) do
     iface
   end
 
+  # determine ring parameters for the interface using ethtool
+  def ethernet_ring_parameters(iface)
+    return iface unless ethtool_binary = find_ethtool_binary
+    iface.each_key do |tmp_int|
+      next unless iface[tmp_int][:encapsulation] == "Ethernet"
+      so = shell_out("#{ethtool_binary} -g #{tmp_int}")
+      Ohai::Log.debug("Parsing ethtool output: #{so.stdout}")
+      # Nasty, brittle regex to capture the ethtool output
+      nasty_regex =
+/Ring parameters for #{tmp_int}:
+Pre-set maximums:
+RX:\s+(\d+)
+.*
+TX:\s+(\d+)
+Current hardware settings:
+RX:\s+(\d+)
+.*
+TX:\s+(\d+)/m
+      if nasty_regex.match(so.stdout)
+        iface[tmp_int]["ring_params"] = {
+          "max_rx" => $1.to_i,
+          "max_tx" => $2.to_i,
+          "current_rx" => $3.to_i,
+          "current_tx" => $4.to_i,
+        }
+      end
+    end
+    iface
+  end
+
   # determine link stats, vlans, queue length, and state for an interface using ip
   def link_statistics(iface, net_counters)
     so = shell_out("ip -d -s link")
@@ -593,6 +623,7 @@ Ohai.plugin(:Network) do
     end # end "ip else net-tools" block
 
     iface = ethernet_layer_one(iface)
+    iface = ethernet_ring_parameters(iface)
     counters[:network][:interfaces] = net_counters
     network["interfaces"] = iface
   end
diff --git a/spec/unit/plugins/linux/network_spec.rb b/spec/unit/plugins/linux/network_spec.rb
index 40bbdc17..ea948deb 100644
--- a/spec/unit/plugins/linux/network_spec.rb
+++ b/spec/unit/plugins/linux/network_spec.rb
@@ -339,6 +339,22 @@ Settings for eth0:
 EOM
   }
 
+  let(:linux_ethtool_g) { <<-EOM
+Ring parameters for eth0:
+Pre-set maximums:
+RX:		8192
+RX Mini:	0
+RX Jumbo:	0
+TX:		8192
+Current hardware settings:
+RX:		8192
+RX Mini:	0
+RX Jumbo:	0
+TX:		8192
+
+EOM
+  }
+
   before(:each) do
     allow(plugin).to receive(:collect_os).and_return(:linux)
 
@@ -352,7 +368,8 @@ EOM
     allow(plugin).to receive(:shell_out).with("route -n").and_return(mock_shell_out(0, linux_route_n, ""))
     allow(plugin).to receive(:shell_out).with("ifconfig -a").and_return(mock_shell_out(0, linux_ifconfig, ""))
     allow(plugin).to receive(:shell_out).with("arp -an").and_return(mock_shell_out(0, linux_arp_an, ""))
-    allow(plugin).to receive(:shell_out).with(/ethtool/).and_return(mock_shell_out(0, linux_ethtool, ""))
+    allow(plugin).to receive(:shell_out).with(/ethtool -g/).and_return(mock_shell_out(0, linux_ethtool_g, ""))
+    allow(plugin).to receive(:shell_out).with(/ethtool [^\-]/).and_return(mock_shell_out(0, linux_ethtool, ""))
   end
 
   describe "#iproute2_binary_available?" do
@@ -554,6 +571,10 @@ EOM
         expect(plugin["network"]["interfaces"]["eth0"]["transceiver"]).to eq("external")
         expect(plugin["network"]["interfaces"]["eth0"]["auto_negotiation"]).to eq("on")
         expect(plugin["network"]["interfaces"]["eth0"]["mdi_x"]).to be_nil
+        expect(plugin["network"]["interfaces"]["eth0"]["ring_params"]["max_tx"]).to eq(8192)
+        expect(plugin["network"]["interfaces"]["eth0"]["ring_params"]["max_rx"]).to eq(8192)
+        expect(plugin["network"]["interfaces"]["eth0"]["ring_params"]["current_tx"]).to eq(8192)
+        expect(plugin["network"]["interfaces"]["eth0"]["ring_params"]["current_rx"]).to eq(8192)
       end
 
       it "detects the ipv4 addresses of the ethernet interface" do