SimpleXMLRPCServer cannot handle large requests

[morissette]

BPO	792570
Nosy	@akuchling, @birkenfeld, @noplay

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/akuchling'
closed_at = <Date 2005-12-04.15:38:47.000>
created_at = <Date 2003-08-21.15:37:31.000>
labels = ['library']
title = 'SimpleXMLRPCServer cannot handle large requests'
updated_at = <Date 2005-12-04.15:38:47.000>
user = 'https://bugs.python.org/morissette'

bugs.python.org fields:

activity = <Date 2005-12-04.15:38:47.000>
actor = 'akuchling'
assignee = 'akuchling'
closed = True
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2003-08-21.15:37:31.000>
creator = 'morissette'
dependencies = []
files = []
hgrepos = []
issue_num = 792570
keywords = []
message_count = 5.0
messages = ['17865', '17866', '17867', '17868', '17869']
nosy_count = 4.0
nosy_names = ['akuchling', 'georg.brandl', 'morissette', 'noplay']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue792570'
versions = ['Python 2.5']

[morissette]

SimpleXMLRPCServer throws a WSAEINTR ioerror on
large XML-RPC requests.

Under Windows, the socket.read() method cannot seem
to handle large (tens of megabytes) reads (could be a
Python specific problem). This means that very large
XML-RPC requests can cause the exception.

Here is a tentative patch against 2.2.3 to fix the
problem. It should be easy to port it to 2.3

---

 /cygdrive/c/Python22/Lib/SimpleXMLRPCServer.py      
2003-07-09 14:16:52.000000000 -0400
+++ /cygdrive/z/SimpleXMLRPCServer.py   2003-08-21 
11:01:19.000000000 -0400
@@ -73,6 +73,8 @@
 import SocketServer
 import BaseHTTPServer
 import sys
+import cStringIO

 class SimpleXMLRPCRequestHandler
(BaseHTTPServer.BaseHTTPRequestHandler):
     """Simple XML-RPC request handler class.
@@ -95,7 +97,14 @@

         try:
             # get arguments
-            data = self.rfile.read(int(self.headers["content-
length"]))
+            max_chunk_size = 10000000
+            content_length = int(self.headers["content-
length"])
+            buffer = cStringIO.StringIO()
+            for offset in range(0, content_length, 
max_chunk_size):
+                chunk_size = min(content_length - offset, 
max_chunk_size)
+                buffer.write(self.rfile.read(chunk_size))
+            data = buffer.getvalue()
+            buffer.close()
             params, method = xmlrpclib.loads(data)

         # generate response

[birkenfeld]

Logged In: YES
user_id=1188172

Marc-Andre, can you still reproduce this with Python 2.4?

[noplay]

Logged In: YES
user_id=446148

I have the same problem with Python2.4 with windows and
linux version.

If XML-RPC server reads to large buffer, it returns only a
part of the buffer.

[akuchling]

Logged In: YES
user_id=11375

Why does SimpleXMLRPCServer need to be fixed if
socket.read() is choking? Shouldn't socket.read() be fixed
instead?

noplay: do you mean you're seeing this bug happen on Linux?
I don't use Windows, so being able to reproduce the problem
on Linux would be very useful.

[akuchling]

Logged In: YES
user_id=11375

It turns out that on my Mac socket.read() runs into trouble
around 15Mb, so I could reproduce the problem. Fix committed
in rev 41586; it's the same principle as the suggested
change, but the code is rewritten for better scalability
(appending to a list instead of using a cStringIO). Thanks!