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<p class=MsoNormal><span style='color:#1F497D'>It turns out that lftp expects
SSH_FXP_STATUS packets to include a language tag (which, looking at draft 3
[which I understand to be the one paramiko’s sftp support conforms to?],
does appear to be mandatory), and presently (prior to the 3.7.2 release), lftp
doesn’t play nice with servers which fail to do so.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>paramiko.sftp_server.SFTPServer._send_status
sends a text field ‘desc’, but no RFC-1766-compliant language
field. The attached patch resolves this, and fixes interoperability with lftp
3.7.1.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>-- <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'><br>
Charles Duffy<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>Systems Engineering<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'><a href="mailto:charles_duffy@messageone.com">charles_duffy@messageone.com</a><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Century Gothic","sans-serif";
color:#1F497D'><a href="http://www.messageone.com/"
title="http://www.messageone.com/"><span style='font-family:"Arial","sans-serif";
color:purple'>http://www.messageone.com</span></a><br>
<br>
</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>Dell MessageOne<br>
11044 Research Blvd<br>
Building C, Fifth Floor<br>
Austin, TX 78759</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif";
color:#1F497D'><o:p></o:p></span></p>
</div>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
paramiko-bounces@lag.net [mailto:paramiko-bounces@lag.net] <b>On Behalf Of </b>Charles
Duffy<br>
<b>Sent:</b> Tuesday, May 06, 2008 5:59 PM<br>
<b>To:</b> paramiko@lag.net<br>
<b>Subject:</b> Re: [paramiko] OpenSSH sftp server returns EOF after
directorylisting, paramiko does not.<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='color:#1F497D'>My initial diagnosis of this
issue was incorrect – paramiko is clearly sending back EOF where
it’s supposed to.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>I’m digging into lftp to
try to track this down.<o:p></o:p></span></p>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>-- <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'><br>
Charles Duffy<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>Systems Engineering<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'><a href="mailto:charles_duffy@messageone.com">charles_duffy@messageone.com</a><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Century Gothic","sans-serif";
color:#1F497D'><a href="http://www.messageone.com/"
title="http://www.messageone.com/"><span style='font-family:"Arial","sans-serif";
color:purple'>http://www.messageone.com</span></a><br>
<br>
</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>Dell MessageOne<br>
11044 Research Blvd<br>
Building C, Fifth Floor<br>
Austin, TX 78759</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif";
color:#1F497D'><o:p></o:p></span></p>
</div>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
paramiko-bounces@lag.net [mailto:paramiko-bounces@lag.net] <b>On Behalf Of </b>Charles
Duffy<br>
<b>Sent:</b> Monday, May 05, 2008 12:25 PM<br>
<b>To:</b> paramiko@lag.net<br>
<b>Subject:</b> [paramiko] OpenSSH sftp server returns EOF after directory
listing,paramiko does not.<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Per subject – if my interpretation of the behavior
described below is correct, lftp (even as current as 3.7.1) appears to be
relying on this behavior.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Running against my paramiko-based server, lftp hangs
indefinitely trying to run a directory listing:<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>---- path on wire is `/'<o:p></o:p></p>
<p class=MsoNormal>---> sending a packet, length=10, type=11(OPENDIR), id=4<o:p></o:p></p>
<p class=MsoNormal><--- got a packet, length=12, type=102(HANDLE), id=4<o:p></o:p></p>
<p class=MsoNormal>---- got file handle 687831 (3)<o:p></o:p></p>
<p class=MsoNormal>---> sending a packet, length=12, type=12(READDIR), id=5<o:p></o:p></p>
<p class=MsoNormal><--- got a packet, length=231, type=104(NAME), id=5<o:p></o:p></p>
<p class=MsoNormal>---- file name count=2<o:p></o:p></p>
<p class=MsoNormal>---> sending a packet, length=12, type=12(READDIR), id=6<o:p></o:p></p>
<p class=MsoNormal>---> sending a packet, length=12, type=12(READDIR), id=7<o:p></o:p></p>
<p class=MsoNormal><--- got a packet, length=24, type=101(STATUS), id=6<o:p></o:p></p>
<p class=MsoNormal><--- got a packet, length=24, type=101(STATUS), id=7 <o:p></o:p></p>
<p class=MsoNormal> ^^ hangs here until interrupted<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>…whereas when running against an OpenSSH server,
behavior is quite different:<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>---- path on wire is `//home/cduffy/tmp/a'<o:p></o:p></p>
<p class=MsoNormal>---> sending a packet, length=28, type=11(OPENDIR), id=4<o:p></o:p></p>
<p class=MsoNormal><--- got a packet, length=13, type=102(HANDLE), id=4<o:p></o:p></p>
<p class=MsoNormal>---- got file handle 00000000 (4)<o:p></o:p></p>
<p class=MsoNormal>---> sending a packet, length=13, type=12(READDIR), id=5<o:p></o:p></p>
<p class=MsoNormal><--- got a packet, length=501, type=104(NAME), id=5<o:p></o:p></p>
<p class=MsoNormal>---- file name count=5<o:p></o:p></p>
<p class=MsoNormal>---> sending a packet, length=13, type=12(READDIR), id=6<o:p></o:p></p>
<p class=MsoNormal>---> sending a packet, length=13, type=12(READDIR), id=7<o:p></o:p></p>
<p class=MsoNormal><--- got a packet, length=28, type=101(STATUS), id=6<o:p></o:p></p>
<p class=MsoNormal>---- status code=1(EOF), message=End of file<o:p></o:p></p>
<p class=MsoNormal>---- eof<o:p></o:p></p>
<p class=MsoNormal><--- got a packet, length=28, type=101(STATUS), id=7<o:p></o:p></p>
<p class=MsoNormal>---- status code=1(EOF), message=End of file<o:p></o:p></p>
<p class=MsoNormal>drwxr-xr-x 4 cduffy
cduffy 4096 May 4 17:48 .<o:p></o:p></p>
<p class=MsoNormal>drwxr-xr-x 4 cduffy
cduffy 4096 May 4 17:33 ..<o:p></o:p></p>
<p class=MsoNormal>-rw-r--r-- 1 cduffy
cduffy 0 May 4
17:48 A<o:p></o:p></p>
<p class=MsoNormal>drwxr-xr-x 3 cduffy
cduffy 4096 May 4 17:33 b<o:p></o:p></p>
<p class=MsoNormal>drwxr-xr-x 3 cduffy
cduffy 4096 May 4 17:33 d<o:p></o:p></p>
<p class=MsoNormal>---> sending a packet, length=13, type=4(CLOSE), id=8<o:p></o:p></p>
<p class=MsoNormal><--- got a packet, length=24, type=101(STATUS), id=8<o:p></o:p></p>
<p class=MsoNormal>---- status code=0(OK), message=Success<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>It appears that STATUS packets 6 and 7 from OpenSSH signal EOF,
while those from paramiko signal some other status (perhaps OK?) which lftp
doesn’t see fit to comment on, even on a maximal debug level.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Is this difference in behavior intentional? Is it within the
letter of the sftp standard? (Where *<b>is</b>* the sftp standard? I’ve
had a fair bit of trouble googling it up).<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Thanks!<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>--
<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'><br>
Charles Duffy<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Systems
Engineering<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'><a
href="mailto:charles_duffy@messageone.com">charles_duffy@messageone.com</a><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Century Gothic","sans-serif"'><a
href="http://www.messageone.com/" title="http://www.messageone.com/"><span
style='font-family:"Arial","sans-serif";color:purple'>http://www.messageone.com</span></a><br>
<br>
</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Dell
MessageOne<br>
11044 Research Blvd<br>
Building C, Fifth Floor<br>
Austin, TX 78759</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><o:p> </o:p></p>
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