ec2_metadata#expand_path private method rewritten to be more Windows friendly

2 files changed, 40 insertions, 4 deletions

diff --git a/lib/ohai/mixin/ec2_metadata.rb b/lib/ohai/mixin/ec2_metadata.rb
index 375b54fb..cf4bdb89 100644
--- a/lib/ohai/mixin/ec2_metadata.rb
+++ b/lib/ohai/mixin/ec2_metadata.rb
@@ -124,10 +124,12 @@ module Ohai
       private
 
       def expand_path(file_name)
-        path = File.expand_path(file_name.gsub(/\=.*$/, '/'), '/')
-        path[0] = '' # remove the initial "/"
-        path << '/' if file_name[-1..-1].eql?('/') # it was a directory
-        path
+        uri = URI.parse(file_name.gsub(/\=.*$/, '/'))
+        path = uri.normalize.to_s
+        # ignore "./" and "../"
+        path.gsub(%r{/\.\.?(?:/|$)}, '/').
+          sub(%r{^\.\.?(?:/|$)}, '').
+          sub(%r{^$}, '/')
       end
 
       def metadata_key(key)
diff --git a/spec/ohai/plugins/ec2_spec.rb b/spec/ohai/plugins/ec2_spec.rb
index e46dd12f..94ab8193 100644
--- a/spec/ohai/plugins/ec2_spec.rb
+++ b/spec/ohai/plugins/ec2_spec.rb
@@ -112,6 +112,40 @@ describe Ohai::System, "plugin ec2" do
       @ohai[:ec2]['iam']['security-credentials']['MyRole']['Code'].should eql 'Success'
       @ohai[:ec2]['iam']['security-credentials']['MyRole']['Token'].should eql '12345678'
     end
+
+    it "should ignore \"./\" and \"../\" on ec2 metadata paths to avoid infinity loops" do
+      @http_client.should_receive(:get).
+        with("/2012-01-12/meta-data/").
+        and_return(mock("Net::HTTP Response", :body => ".\n./\n..\n../\npath1/.\npath2/./\npath3/..\npath4/../"))
+
+      @http_client.should_not_receive(:get).
+        with("/2012-01-12/meta-data/.")
+      @http_client.should_not_receive(:get).
+        with("/2012-01-12/meta-data/./")
+      @http_client.should_not_receive(:get).
+        with("/2012-01-12/meta-data/..")
+      @http_client.should_not_receive(:get).
+        with("/2012-01-12/meta-data/../")
+      @http_client.should_not_receive(:get).
+        with("/2012-01-12/meta-data/path1/..")
+
+      @http_client.should_receive(:get).
+        with("/2012-01-12/meta-data/path1/").
+        and_return(mock("Net::HTTP Response", :body => ""))
+      @http_client.should_receive(:get).
+        with("/2012-01-12/meta-data/path2/").
+        and_return(mock("Net::HTTP Response", :body => ""))
+      @http_client.should_receive(:get).
+        with("/2012-01-12/meta-data/path3/").
+        and_return(mock("Net::HTTP Response", :body => ""))
+      @http_client.should_receive(:get).
+        with("/2012-01-12/meta-data/path4/").
+        and_return(mock("Net::HTTP Response", :body => ""))
+
+      @ohai._require_plugin("ec2")
+
+      @ohai[:ec2].should_not be_nil
+    end
   end
 
   describe "with ec2 mac and metadata address connected" do