Message: previous - next
Month: April 2012

Re: [trinity-devel] sftp_kio - fix ssh port number read

From: "David C. Rankin" <drankinatty@...>
Date: Tue, 24 Apr 2012 13:38:23 -0500
On 04/24/2012 12:51 PM, Timothy Pearson wrote:
> I am not convinced that kio_sftp (or kio_fish) reads ANYTHING from
> ~/.ssh/config, rather I suspect it relies on implicit ssh behavior when
> ssh is invoked in the background.  Something probably changed there; I
> will look into the problem shortly.
> Tim

I'm looking too. I'm reading the ssh man pages. I'm guessing that there is a 
separate call to ssh somewhere that causes ssh to return the port number for 
the host or that there is a way that this information is read 'on-the-fly' 
when 'ssh hostname' is given.

When I'm in a directory in the code line tdebase/kioslave/sftp -- is there 
some c++ 'tool' I can run that will scan the code and give me a representation 
of how the files and functions are called? Kind of like a process diagram? 
Something that says 'this file is executed first, second, etc..' That would 
really help me find my way around.

Especially with things like bool KSshProcess::setOptions(const SshOptList& 
opts) -- what the heck is SshOptList and where is it filled? That's the type 
question that really hangs me up. I can grep it, but that doesn't help 90% of 
the time.

ksshprocess seems to talk the most about setting up the connection. eg:


  * To setup a SSH connection first create a list of options to use and tell
  * KSshProcess about your options. Then start the ssh connection. Once the
  * connection is setup use the  stdin, stdout, stderr, and pty file descriptors
  * to communicate with ssh. For a detailed example of how to use, see
  * ksshprocesstest.cpp.


  * To start ssh we take the arguments the user gave us
  * in the SshOptList and build the ssh command arguments based on the version
  * of ssh we are using.  This command and its arguments are  passed to
  * PTYProcess for execution.  Once ssh is started we scan each line of input
  * from stdin, stderr, and the pty for recognizable strings.  The recognizable
  * strings are taken from several string tables.  Each table contains a string
  * for each specific version of ssh we support and a string for a generic
  * version of OpenSSH and commercial SSH incase we don't recognized the
  * specific ssh version strings (as when a new SSH version is released after
  * a release of KSshProcess).  There are tables for ssh version strings,
  * password prompts, new host key errors, different host key errors,
  * messages than indicate a successful connect, authentication errors, etc.
  * If we find user interaction is necessary, for instance to provide a
  * password or passphrase, we return a err code to the user who can send
  * a message to KSshProcess, using one of several methods, to correct
  * the error.

I have no doubt you will find the key to unlock the chest far before I do...

David C. Rankin, J.D.,P.E.