proxy_pass: X-Forwarded-For appends to existing list

Ugh, this is a little slower, but some people will want to
forward through multiple proxies.

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/yahns/proxy_pass.rb b/lib/yahns/proxy_pass.rb
index 8e0b742..a30089d 100644
--- a/lib/yahns/proxy_pass.rb
+++ b/lib/yahns/proxy_pass.rb
@@ -59,9 +59,12 @@ class Yahns::ProxyPass # :nodoc:
       ver = 'HTTP/1.0'.freeze
     end
 
+    addr = env['REMOTE_ADDR']
+    xff = env['HTTP_X_FORWARDED_FOR']
+    xff = xff =~ /\S/ ? "#{xff}, #{addr}" : addr
     req = "#{env['REQUEST_METHOD']} #{req} #{ver}\r\n" \
           "X-Forwarded-Proto: #{env['rack.url_scheme']}\r\n" \
-          "X-Forwarded-For: #{env["REMOTE_ADDR"]}\r\n".dup
+          "X-Forwarded-For: #{xff}\r\n".dup
 
     # pass most HTTP_* headers through as-is
     chunked = false