Handling Expect-100 Continue header

lib/puma/client.rb

@@ -89,6 +89,8 @@ def initialize(io, env=nil)
       @http_content_length_limit = nil
       @http_content_length_limit_exceeded = false
 
+      @http_expect_100_continue_header_present = false
+
       @peerip = nil
       @peer_family = nil
       @listener = nil
@@ -104,7 +106,8 @@ def initialize(io, env=nil)
     end
 
     attr_reader :env, :to_io, :body, :io, :timeout_at, :ready, :hijacked,
-                :tempfile, :io_buffer, :http_content_length_limit_exceeded
+                :tempfile, :io_buffer, :http_content_length_limit_exceeded,
+                :http_expect_100_continue_header_present
 
     attr_writer :peerip, :http_content_length_limit
 
@@ -158,6 +161,7 @@ def reset(fast_check=true)
       @peerip = nil if @remote_addr_header
       @in_last_chunk = false
       @http_content_length_limit_exceeded = false
+      @http_expect_100_continue_header_present = false
 
       if @buffer
         return false unless try_to_parse_proxy_protocol
@@ -342,10 +346,7 @@ def setup_body
       @body_read_start = Process.clock_gettime(Process::CLOCK_MONOTONIC, :float_millisecond)
 
       if @env[HTTP_EXPECT] == CONTINUE
-        # TODO allow a hook here to check the headers before
-        # going forward
-        @io << HTTP_11_100
-        @io.flush
+        @http_expect_100_continue_header_present = true
       end
 
       @read_header = false

lib/puma/request.rb

@@ -158,6 +158,7 @@ def prepare_response(status, headers, res_body, requests, client)
       env = client.env
       socket = client.io
       io_buffer = client.io_buffer
+      expect_100_continue = client.http_expect_100_continue_header_present
 
       return false if closed_socket?(socket)
 
@@ -169,7 +170,7 @@ def prepare_response(status, headers, res_body, requests, client)
         @thread_pool.busy_threads < @max_threads ||
         !client.listener.to_io.wait_readable(0)
 
-      resp_info = str_headers(env, status, headers, res_body, io_buffer, force_keep_alive)
+      resp_info = str_headers(env, status, headers, res_body, io_buffer, force_keep_alive, expect_100_continue)
 
       close_body = false
       response_hijack = nil
@@ -568,8 +569,7 @@ def fetch_status_code(status)
     # @return [Hash] resp_info
     # @version 5.0.3
     #
-    def str_headers(env, status, headers, res_body, io_buffer, force_keep_alive)
-
+    def str_headers(env, status, headers, res_body, io_buffer, force_keep_alive, expect_100_continue)
       line_ending = LINE_END
       colon = COLON
 
@@ -581,6 +581,9 @@ def str_headers(env, status, headers, res_body, io_buffer, force_keep_alive)
         resp_info[:allow_chunked] = true
         resp_info[:keep_alive] = env.fetch(HTTP_CONNECTION, "").downcase != CLOSE
 
+        if expect_100_continue
+          io_buffer << HTTP_11_100
+        end
         # An optimization. The most common response is 200, so we can
         # reply with the proper 200 status without having to compute
         # the response header.
@@ -592,6 +595,7 @@ def str_headers(env, status, headers, res_body, io_buffer, force_keep_alive)
 
           resp_info[:no_body] ||= status < 200 || STATUS_WITH_NO_ENTITY_BODY[status]
         end
+
       else
         resp_info[:allow_chunked] = false
         resp_info[:keep_alive] = env.fetch(HTTP_CONNECTION, "").downcase == KEEP_ALIVE

test/test_web_server.rb

@@ -99,6 +99,14 @@ def test_nonexistent_http_method
     socket.close
   end
 
+  def test_expect_100_header
+    request = "POST /test HTTP/1.1\r\nHost: www.zedshaw.com\r\nContent-Type: text/plain\r\nExpect: 100-continue\r\nContent-Length: 5\r\n\r\nHello"
+    socket = do_test(request, request.length)
+    response = socket.read
+    assert_match "HTTP/1.1 100 Continue", response
+    socket.close
+  end
+
   private
 
   def do_test(string, chunk)