Bug #12890: Net::HTTP should treat unexpected 1XX responses as non-final. - Ruby master - Ruby Issue Tracking System

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Bug #12890

closed

Net::HTTP should treat unexpected 1XX responses as non-final.

Added by lukasa (Cory Benfield) about 8 years ago. Updated about 8 years ago.

Status:

Closed

Assignee:

Target version:

ruby -v:

ruby 2.3.0p0 (2015-12-25 revision 53290) [x86_64-darwin16]

Backport:

2.1: REQUIRED, 2.2: DONE, 2.3: DONE

[ruby-core:77866]

Description

Long story short

Net::HTTP's client does not tolerate non-100 status codes from the 1XX block in a sensible manner: it treats them as final responses, rather than as provisional ones.

Expected behaviour

When Net::HTTP receives a 1XX status code that it does not recognise, it should either surface these to a user in such a way that allows the user to access the subsequent final response, or it should ignore them and only show the user the eventual final status code. This is required by RFC 7231 Section 6.2 (Informational 1xx), which reads:

A client MUST be able to parse one or more 1xx responses received prior to a final response, even if the client does not expect one. A user agent MAY ignore unexpected 1xx responses.

Actual behaviour

Net::HTTP treats the 1XX status code as final. It parses the header block as though it were a response in the 2XX or higher range. Net::HTTP rightly assumes that 1XX responses have no body, which means that it leaves the following 2XX response unconsumed in the socket buffer, which will hide critical data from the user.

Steps to reproduce

The following Python "server" can demonstrate the issue:

import socket
import time

document = b'''<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <title>title</title>
    <link rel="stylesheet" href="/other/styles.css">
    <script src="/other/action.js"></script>
  </head>
  <body>
    <h1>Hello, world!</h1>
  </body>
</html>
'''

s = socket.socket()
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind(('localhost', 8080))
s.listen(5)

while True:
    new_socket, _ = s.accept()
    data = b''

    while not data.endswith(b'\r\n\r\n'):
        data += new_socket.recv(8192)

    new_socket.sendall(
        b'HTTP/1.1 103 Early Hints\r\n'
        b'Server: socketserver/1.0.0\r\n'
        b'Link: </other/styles.css>; rel=preload; as=style\r\n'
        b'Link: </other/action.js>; rel=preload; as=script\r\n'
        b'\r\n'
    )
    time.sleep(1)
    new_socket.sendall(
        b'HTTP/1.1 200 OK\r\n'
        b'Server: socketserver/1.0.0\r\n'
        b'Content-Type: text/html\r\n'
        b'Content-Length: %s\r\n'
        b'Link: </other/styles.css>; rel=preload; as=style\r\n'
        b'Link: </other/action.js>; rel=preload; as=script\r\n'
        b'Connection: close\r\n'
        b'\r\n' % len(document)
    )
    new_socket.sendall(document)
    new_socket.close()

If this server is run directly, the following client can be used to test it:

require 'net/http'

uri = URI('http://localhost:8080/')
res = Net::HTTP.get_response(uri)
puts "Status: #{res.code}"
puts "Body: #{res.body}"

This client will print

Status: 103
Body:

Note that the client has treated the 1XX response as final, and has left the 200 response unconsumed in the socket.

Files

patch1.diff (2.17 KB) patch1.diff

phluid61 (Matthew Kerwin), 11/02/2016 10:02 PM

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#1 [ruby-core:77867]

Updated by duerst (Martin Dürst) about 8 years ago

Subject changed from Net::HTTP treats unexpected 1XX responses as final. to Net::HTTP should treat unexpected 1XX responses as non-final.

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#2 [ruby-core:77870]

Updated by phluid61 (Matthew Kerwin) about 8 years ago

File patch1.diff patch1.diff added

I believe the fix is relatively simple; the main change is to lib/net/http.rb:

--- a/lib/net/http.rb
+++ b/lib/net/http.rb
@@ -1439,7 +1439,7 @@ def transport_request(req)
           begin
             res = HTTPResponse.read_new(@socket)
             res.decode_content = req.decode_content
-          end while res.kind_of?(HTTPContinue)
+          end while res.continue?
 
           res.uri = req.uri

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#3 [ruby-core:77883]

Updated by lukasa (Cory Benfield) about 8 years ago

Apologies, it was noted that it would be more helpful to provide the example server in Ruby instead:


require 'socket'

server = TCPServer.new 8080

loop do
    client = server.accept
    client.puts "HTTP/1.1 103 Early Hints\r\n" +
                "Server: socketserver/1.0.0\r\n" +
                "Link: </other/styles.css>; rel=preload; as=style\r\n" +
                "Link: </other/action.js>; rel=preload; as=script\r\n" +
                "\r\n"
    sleep 1
    client.puts "HTTP/1.1 200 OK\r\n" +
                "Server: socketserver/1.0.0\r\n" +
                "Content-Length: 0\r\n" +
                "Link: </other/styles.css>; rel=preload; as=style\r\n" +
                "Link: </other/action.js>; rel=preload; as=script\r\n" +
                "Connection: close\r\n" +
                "\r\n"
    client.close
end