Access the html5 UI through reverse proxy cause exception when websocket is connecting

[totaam]

Issue migrated from trac ticket # 2160

component: html5 | priority: major | resolution: fixed

2019-02-21 09:32:10: tardyp created the issue

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Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/xpra/net/protocol.py", line 734, in _read_parse_thread_loop
    self.do_read_parse_thread_loop()
  File "/usr/lib/python2.7/dist-packages/xpra/net/protocol.py", line 767, in do_read_parse_thread_loop
    read_buffer = read_buffer + buf
TypeError: unsupported operand type(s) for +: 'memoryview' and 'memoryview'

This bug only happens when I go through reverse proxy (traefik in kubernetes) to access the xpra websocket service.

I have a patch for that in the 2.4.x branch:

diff --git a/tags/v2.4.x/src/xpra/net/protocol.py b/tags/v2.4.x/src/xpra/net/protocol.py
index 1c4f90bda..92459108d 100644
--- a/tags/v2.4.x/src/xpra/net/protocol.py
+++ b/tags/v2.4.x/src/xpra/net/protocol.py
@@ -764,7 +764,7 @@ class Protocol(object):
                 self.idle_add(self.close)
                 return
             if read_buffer:
-                read_buffer = read_buffer + buf
+                read_buffer = memoryview_to_bytes(read_buffer) + memoryview_to_bytes(buf)
             else:
                 read_buffer = buf
             bl = len(read_buffer

This part has heavily changed in trunk, and I have not tested if this bug happens on trunk as well.

[totaam]

2019-02-21 09:49:29: antoine uploaded file protocol-memoryview-merge.patch (0.6 KiB)

patch for trunk

[totaam]

Following the changes in #2121, I don't think that trunk needs the patch above: my guess is that your proxy must be slicing the websocket data using continuation frames, we already handle those by calling memoryview_to_bytes since r21542.
But please test to confirm as I do not have a proxy to use for testing, otherwise 2.5 will be released soon with this bug.

As for v2.4 (soon to be abandoned), I have applied a different fix in 21784 so as not to penalize the other transport protocol backends with the extra call to memoryview_to_bytes.
Unfortunately, it is still going to make things slower for all websocket users (despite the fact that very few users may be hitting this issue..). That's one of the reasons why #2121 was needed.

Please close if that works for you.

[totaam]

2019-02-21 10:32:51: tardyp commented

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fixed in latest 2.5 beta