[PATCH] http_response: drop bodies for non-compliant responses

[PATCH] http_response: drop bodies for non-compliant responses

[Eric Wong]

Rack::Lint-compliant applications wouldn't have this problem;
but apparently public-facing Rack servers (webrick/puma/thin)
all implement this; so there is precedence for implementing
this in yahns itself.
---
 lib/yahns/http_client.rb   |  9 ++++++---
 lib/yahns/http_response.rb | 12 +++++-------
 test/test_response.rb      | 42 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+), 10 deletions(-)

diff --git a/lib/yahns/http_client.rb b/lib/yahns/http_client.rb
index 1cdaa0f..873dd73 100644
--- a/lib/yahns/http_client.rb
+++ b/lib/yahns/http_client.rb
@@ -189,9 +189,11 @@ def r100_done
       mkinput_preread # keep looping (@state == :body)
       true
     else # :lazy, false
-      status, headers, body = k.app.call(env = @hs.env)
+      env = @hs.env
+      hdr_only = env['REQUEST_METHOD'] == 'HEAD'.freeze
+      status, headers, body = k.app.call(env)
       return :ignore if app_hijacked?(env, body)
-      http_response_write(status, headers, body)
+      http_response_write(status, headers, body, hdr_only)
     end
   end
 
@@ -220,6 +222,7 @@ def app_call(input)
       env['SERVER_PORT'] = '443'.freeze
     end
 
+    hdr_only = env['REQUEST_METHOD'] == 'HEAD'.freeze
     # run the rack app
     status, headers, body = k.app.call(env)
     return :ignore if app_hijacked?(env, body)
@@ -229,7 +232,7 @@ def app_call(input)
     end
 
     # this returns :wait_readable, :wait_writable, :ignore, or nil:
-    http_response_write(status, headers, body)
+    http_response_write(status, headers, body, hdr_only)
   end
 
   # called automatically by kgio_write
diff --git a/lib/yahns/http_response.rb b/lib/yahns/http_response.rb
index d957df6..88ff9f9 100644
--- a/lib/yahns/http_response.rb
+++ b/lib/yahns/http_response.rb
@@ -9,7 +9,7 @@
 # You use it by simply doing:
 #
 #   status, headers, body = rack_app.call(env)
-#   http_response_write(status, headers, body)
+#   http_response_write(status, headers, body, env['REQUEST_METHOD']=='HEAD')
 #
 # Most header correctness (including Content-Length and Content-Type)
 # is the job of Rack, with the exception of the "Date" header.
@@ -118,13 +118,9 @@ def kv_str(buf, key, value)
     end
   end
 
-  def have_more?(value)
-    value.to_i > 0 && @hs.env['REQUEST_METHOD'] != 'HEAD'.freeze
-  end
-
   # writes the rack_response to socket as an HTTP response
   # returns :wait_readable, :wait_writable, :forget, or nil
-  def http_response_write(status, headers, body)
+  def http_response_write(status, headers, body, hdr_only)
     offset = 0
     count = hijack = nil
     k = self.class
@@ -133,6 +129,7 @@ def http_response_write(status, headers, body)
 
     if @hs.headers?
       code = status.to_i
+      hdr_only ||= Rack::Utils::STATUS_WITH_NO_ENTITY_BODY.include?(code)
       msg = Rack::Utils::HTTP_STATUS_CODES[code]
       buf = "#{response_start}#{msg ? %Q(#{code} #{msg}) : status}\r\n" \
             "Date: #{httpdate}\r\n".dup
@@ -150,7 +147,7 @@ def http_response_write(status, headers, body)
           # allow Rack apps to tell us they want to drop the client
           alive = false if value =~ /\bclose\b/i
         when %r{\AContent-Length\z}i
-          flags |= MSG_MORE if have_more?(value)
+          flags |= MSG_MORE if value.to_i > 0 && !hdr_only
           kv_str(buf, key, value)
         when "rack.hijack"
           hijack = value
@@ -181,6 +178,7 @@ def http_response_write(status, headers, body)
     end
 
     return response_hijacked(hijack) if hijack
+    return http_response_done(alive) if hdr_only
 
     if body.respond_to?(:to_path)
       @state = body = Yahns::StreamFile.new(body, alive, offset, count)
diff --git a/test/test_response.rb b/test/test_response.rb
index a71fd65..34a4c90 100644
--- a/test/test_response.rb
+++ b/test/test_response.rb
@@ -9,6 +9,48 @@ class TestResponse < Testcase
   alias setup server_helper_setup
   alias teardown server_helper_teardown
 
+  def test_auto_head
+    err = @err
+    cfg = Yahns::Config.new
+    host, port = @srv.addr[3], @srv.addr[1]
+    str = "HELLO WORLD\n"
+    cfg.instance_eval do
+      GTL.synchronize do
+        app = Rack::Builder.new do
+          use Rack::ContentLength
+          use Rack::ContentType, "text/plain"
+          run(lambda do |env|
+            case env['PATH_INFO']
+            when '/'; return [ 200, {}, [ str ] ]
+            when '/304'; return [ 304, {}, [ str ] ]
+            else
+              abort 'unsupported'
+            end
+          end)
+        end
+        app(:rack, app) { listen "#{host}:#{port}" }
+      end
+      logger(Logger.new(err.path))
+    end
+    pid = mkserver(cfg)
+    s = TCPSocket.new(host, port)
+    s.write("HEAD / HTTP/1.0\r\n\r\n")
+    assert s.wait(30), "IO wait failed"
+    buf = s.read
+    assert_match %r{\r\n\r\n\z}, buf
+    s.close
+
+    s = TCPSocket.new(host, port)
+    s.write("GET /304 HTTP/1.0\r\n\r\n")
+    assert s.wait(30), "IO wait failed"
+    buf = s.read
+    assert_match %r{\r\n\r\n\z}, buf
+    assert_match %r{\b304\b}, buf
+    s.close
+  ensure
+    quit_wait(pid)
+  end
+
   def test_response_time_empty_body
     err = @err
     cfg = Yahns::Config.new
-- 
EW