Invalid packet format

[Alexei Volkov]

I am running linuxmint olivia amd64 and have a try xpra for a first time. apt-get install xpra installs me 0.10.1 version.

According to minimal instructions on first console i try to run

xpra start :100 --start-child=xterm --no-daemon --no-notifications --no-pulseaudio

and xpra attach :100
on second console that quickly ends with

xpra attach :100
xpra client version 0.10.1
2013-08-29 10:30:58,477 No OpenGL_accelerate module loaded: No module named OpenGL_accelerate
2013-08-29 10:30:58,635 OpenGL Version: 3.3.0 NVIDIA 313.30
2013-08-29 10:30:58,659 GL Extension GL_ARB_shader_objects available
2013-08-29 10:30:58,683 GL Extension GL_ARB_framebuffer_object available
2013-08-29 10:30:58,685 GL Extension GL_ARB_fragment_program available
2013-08-29 10:30:58,686 GL Extension GL_ARB_texture_rectangle available
2013-08-29 10:30:58,686 GL Extension GL_ARB_vertex_program available
2013-08-29 10:30:58,876 server requested disconnect: invalid packet format
2013-08-29 10:30:58,877 connection closed after 1 packets received (55 bytes) and 1 packets sent (25K bytes)
2013-08-29 10:30:58,978 Connection lost

on a server side i see an exception

2013-08-29 10:30:58,208 New connection received: SocketConnection(/home/kot/.xpra/volkovav-100)
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/xpra/net/bencode.py", line 72, in bdecode
    r, l = decode_func[x[0]](x, 0)
  File "/usr/lib/python2.7/dist-packages/xpra/net/bencode.py", line 45, in decode_list
    v, f = decode_func[x[f]](x, f)
  File "/usr/lib/python2.7/dist-packages/xpra/net/bencode.py", line 57, in decode_dict
    r[k], f = decode_func[x[f]](x, f)
IndexError: string index out of range
2013-08-29 10:30:58,845 value error reading packet: 
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/xpra/net/protocol.py", line 641, in do_read_parse_thread_loop
    packet, l = bdecode(data)
  File "/usr/lib/python2.7/dist-packages/xpra/net/bencode.py", line 76, in bdecode
    raise ValueError
ValueError

full log in attachment

[Alexei Volkov]

xpra start log

[Antoine Martin]

Hmmm, that's going to be difficult to diagnose.
Somehow the initial packet gets encoded but fails to decode..
And since logging network packets was slowing things down too much, I have removed it. So, to see the actual packet contents, you will have to use "-z 0" to turn off decompression, connect to a tcp socket ("xpra start --bind-tcp" + "xpra attach tcp:HOST:port") and use tcpdump or ngrep to capture it.

The encoder code has not changed at all in a very long time.
But the amount of data we include in the hello packet has, so downgrading to 0.9.x may help.

[Alexei Volkov]

tcpdump log

[Alexei Volkov]

ok.

xpra start :100 --start-child=xterm --no-daemon --no-notifications --no-pulseaudio -z 0 --bind-tcp 127.0.0.1:8888

xpra attach tcp:127.0.0.1:8888

tcpdump -w /tmp/xpra.pcap -s 2048 -i lo port 8888

and xpra.pcap​ in attachment

[Antoine Martin]

(only just saw your tcpdump as I was writing this)
I've tried reproducing the bug using the packet string from the bug, but the packet string sample isn't long enough:

s = "l5:hellod7:aliasesd4:belli11e9:challengei14e27:configure-override-redirecti7e15:connection-"+
    "losti22e6:cursori16e12:desktop_sizei12e10:disconnecti9e4:drawi8e9:gibberishi24e5:helloi15e13:info-
    "responsei2e11:lost-windowi6e21:new-override-redirecti13e8:new-trayi25e10:new-"+
    "windowi23e12:notify_closei10e11:notify_showi20e4:pingi3e9:ping_echoi5e11:set_deflatei18e10:sound-"+
    "datai1e16:startup-completei21e11:window-iconi26e15:window-metadatai19e14:window-"+
    "resizedi17ee18:auto_refresh_delayi250e4:belli1e9:build.bit5:64bit8:build.by8:buildbot9:build.cpu6:"+
    "x86_6410:build.date10:2013-08-2025:build.local_modifications1:08:build.on13:winswitch.org14"+
    ":build.revision4:419119:chunked_compressioni1e11:client_type11:Python/Gtk29:clipboardi1e16:"+
    "clipboard.greedyi0e23:clipboard.notificationsi1e22:clipboard.want_targetsi0e20:compressible_cursorsi1e7:"+
    "cursorsi1e12:desktop_sizeli1920ei1080ee3:dpii96e20:encoding.PIL.version5:1.1.724:encoding.avcodec.version11"+
    ":Lavc53.35.023:encoding.client_optionsi1e18:encoding.csc_atomsi1e18:encoding.csc_modesl7:YUV420P7:YUV422P7:"+
    "YUV444P4:BGRA4:BGRXe24:encoding.initial_qualityi50e20:encoding.min-qualityi50e18:encoding.min-speedi0e18:"+
    "encoding.rgb24zlibi1e23:encoding.supports_deltal3:png5:rgb245:rgb32e24:encoding.swscale.version8:SwS2.1.021:"+
    "encoding.transparencyi1e21:encoding.uses_swscalei1e22:encoding.video_scalingi1e20:encoding.vpx.versioni3e21:"+
    "encoding.webp.version5:0.2.226:encoding.x264.I420.profile6:high1029:encoding.x264.YUV420P.profile6:high1021:"+
    "encoding.x264.versioni123e23:encoding_client_optionsi1e9:encodingsl4:x2643:vpx4:webp3:png5:png/P5:png/L3:rgb4:jpege14:"+
    "encodings.corel5:rgb243:vpx4:x2644:webp3:png5:png/L5:png/P4:jpeg5:rgb32e21:encodings.rgb_formatsl3:RGB4:RGBAe21:"+
    "generic-rgb-encodingsi1e20:generic_window_typesi1e11:gtk.versionli2ei24ei17ee8:hostname8:volkovav10:key_repeatli500ei30ee13:"+
    "keyboard_synci1e9:mmap_file21:/tmp/xpra.3zOs4t.mmap10:mmap_tokeni244925642224448813989947185054562865453e9:"+
    "modifiersle4:name27:\xd0\x90\xd0\xbb\xd0\xb5\xd0\xba\xd1\x81\xd0\xb5\xd0\xb9 \xd0\x92\xd0\xbe\xd0\xbb\xd0\xba\xd0\xbe\xd0\xb213:"+
    "named_cursorsi1e9:namespacei1e13:notificationsi1e23:notify-startup-completei1e8:platform6:linux216:platform.machine6:"+
    "x86_6418:platform.processor6:x86_6416:platform.release16:3.8.0-19-generic13:pygtk.versionli2ei24ei0ee14:"+
    "python.versionli2ei7ei4ee12:randr_notifyi1e11:raw_packetsi1e16:raw_window_iconsi1e7:rencodei1e15:"+
    "rencode.version5:1.0.29:rgb24zlibi1e12:screen_sizesll4::0.0i1920ei1080ei483ei272ell7:"+
    "DVI-I-1i0ei0ei1920ei1080ei477ei268eeei0ei0ei1920ei1055eee20:server-window-resizei1e11:"+
    "server_uuid0:5:sharei0e14:sound.decodersl3:mp37:wavpack3:wav4:flac5:speexe14:"+
    "sound.encodersl3:mp37:wavpack3:wav4:flac5:speexe17:sound.gst.versionli0ei10ei36ee19:"+
    "sound.pulseaudio.id42:1000@2f6a9045c2bc8db6bf32b2d7517969bf/250423:sound.pulseaudio.server65:"+
    "{2f6a9045c2bc8db6bf32b2d7517969bf}unix:/run/user/kot/pulse/native19:sound.pygst.versionli0ei10ei22ee13:"+
    "sound.receivei1e10:sound.sendi1e11:system_trayi1e8:username3:kot4:uuid40:1b63a015423d830f6fc37"
from xpra.net.bencode import bdecode
bdecode(s)

[Antoine Martin]

Python and strings is a terrible mess...

I suspect that this has something to do with unicode characters in the hello packet, can you try temporarily setting your name (as found in /etc/passwd to a pure ascii string instead? Or even just as a newly created test user (say "test"). And anything else in your `env` that has non-ascii characters. Does this fix things?

[Alexei Volkov]

I have changed user name to latin only chars and it fixes an issue. Is it possible to override it with some environment variable instead of changing username in /etc/passwd ?

[Antoine Martin]

Is it possible to override it with some environment variable instead of changing username in /etc/passwd ?

No, we get it from the system's pwd API.
But I will cook up a fix today and release 0.10.2

[Alexei Volkov]

Thanks in advance!

[Antoine Martin]

I had done some work already on strings and unicode to try to revive the python3/gtk3 client support, see r4205, r4206, r4207 and r4209 (it was a bit messy as I messed up the commits..)

r4237 works for me even after changing my name in /etc/passwd

If you can, please confirm that r4237 (for trunk) or (r4238 for v0.10.x branch) fixes things for you too.
I will release 0.10.2 with the fix asap.

What is odd is that I get a different error from the one you posted, mine is client side:

error in write format loop
Traceback (most recent call last):
  File "/usr/lib64/python2.7/site-packages/xpra/net/protocol.py", line 270, in _write_format_thread_loop
    self._add_packet_to_queue(*self._get_packet_cb())
  File "/usr/lib64/python2.7/site-packages/xpra/net/protocol.py", line 280, in _add_packet_to_queue
    chunks, proto_flags = self.encode(packet)
  File "/usr/lib64/python2.7/site-packages/xpra/net/protocol.py", line 424, in encode
    data = zcompress(main_packet, level)
  File "/usr/lib64/python2.7/site-packages/xpra/net/protocol.py", line 54, in zcompress
    return compress(packet, level)
UnicodeEncodeError: 'ascii' codec can't encode characters in position 276-282: ordinal not in range(128)
connection lost: error in network packet write/format: 'ascii' codec can't encode characters in position 276-282: ordinal not in range(128)
connection closed after 0 packets received (0.0 bytes) and 0 packets sent (0.0 bytes)
Connection lost

Even without compression (-z 0):

error in write format loop
Traceback (most recent call last):
  File "/usr/lib64/python2.7/site-packages/xpra/net/protocol.py", line 270, in _write_format_thread_loop
    self._add_packet_to_queue(*self._get_packet_cb())
  File "/usr/lib64/python2.7/site-packages/xpra/net/protocol.py", line 284, in _add_packet_to_queue
    self._add_chunks_to_queue(chunks, proto_flags, start_send_cb, end_send_cb)
  File "/usr/lib64/python2.7/site-packages/xpra/net/protocol.py", line 317, in _add_chunks_to_queue
    data = str(data)
UnicodeEncodeError: 'ascii' codec can't encode characters in position 276-282: ordinal not in range(128)
connection lost: error in network packet write/format: 'ascii' codec can't encode characters in position 276-282: ordinal not in range(128)
connection closed after 0 packets received (0.0 bytes) and 0 packets sent (0.0 bytes)
Connection lost

[Alexei Volkov]

I confirm it works now just fine.

[Antoine Martin]

Closing. Thanks for your help!

v0.10.2 has been released with the fix, it is available in ​source form and ​binary packages will follow shortly.

[migration script]

this ticket has been moved to: ​https://github.com/Xpra-org/xpra/issues/424