Axway XFB sftp server & no-more-sessions at openssh.com

[Partenie, Sergiu]

Hello all,

First of all, thank you for such great software.

I have a bug (and a fix) to report for 5.1p:

The "Axway XFB.Gateway" SFTP server will drop sftp sessions initiated from the OpenSSH 5.1p (HP-UX) sftp if it receives the "no-more-sessions at openssh.com" flag.
It can be reproduced also with the sftp sessions initiated from a OpenSSH 5.1p sftp on a Linux machine.

As a workaround we are using now "-oControlMaster=yes" for each sftp connection in order to disable the sending of "no-more-sessions at openssh.com" flag.

Can you please add for future versions in "compat.c" that for connections to servers who identify themselves as "XFB.Gateway Unix" a flag should be set that "no-more-sessions at openssh.com" is not sent to that server ?

Thanks a lot !

excerpts from sftp -vvv (without "-oControlMaster=yes")
=========
...
debug1: Remote protocol version 2.0, remote software version XFB.Gateway Unix
debug1: no match: XFB.Gateway Unix
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.1p1+sftpfilecontrol-v1.2-hpn13v5
...
debug1: Authentication succeeded (publickey).
debug2: fd 5 setting O_NONBLOCK
debug2: fd 6 setting O_NONBLOCK
debug1: Final hpn_buffer_size = 2097152
debug1: HPN Disabled: 1, HPN Buffer Size: 2097152
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug1: Requesting no-more-sessions at openssh.com
debug1: Entering interactive session.
debug2: callback start
debug2: client_session2_setup: id 0
debug1: Sending subsystem: sftp
debug2: channel 0: request subsystem confirm 1
debug2: fd 4 setting TCP_NODELAY
debug2: callback done
debug2: channel 0: open confirm rwindow 32768 rmax 16384
debug1: channel 0: free: client-session, nchannels 1
debug3: channel 0: status: The following connections are open:
  #0 client-session (t4 r660 i0/9 o0/0 fd 5/6 cfd -1)
 
debug3: channel 0: close_fds r 5 w 6 e 7 c -1
debug1: fd 0 clearing O_NONBLOCK
debug1: fd 1 clearing O_NONBLOCK
Connection to XX.XX.XX.XX closed by remote host.
Transferred: sent 2152, received 1088 bytes, in 0.1 seconds
Bytes per second: sent 16388.3, received 8285.6
debug1: Exit status -1
Connection closed
===========