Hello Greg and David,
I see that there is a great work done with Net::SSH::Perl. I am happy
since I was missing a functionnality, and I think that we can obtain result
with the additions you have done.
I want to be able to write something like (with an existing ssh object, login
done)
$ssh->scp_push($localfile,$remotefile);
or
$ssh->scp_get($remotefile,$localfile);
It is possible with the module Net::SSH2 that David have written, and it is
good enough for me, but ssh-agent si not supported with this module, and it
is a key point.
I didn't find the RFC where scp is described, so I had to analyze openssh and
libssh2 in order to understand why I need to do.
I have finally produce a protoype of what I want in Net/SSH/Perl/SSH2.pm
sub scp_push {
my $ssh = shift;
my ($filesrc, $filedest) = @_;
my ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,
$atime,$mtime,$ctime,$blksize,$blocks)
= stat($filesrc);
open( my $filehandle, "$filesrc" ) or croak("Cannot open file $filesrc $!");
binmode ($filehandle);
my @tmp=split("/",$filesrc);
my $filesrc_invocation=$tmp[$#tmp];
my $cmd = "scp -v -t $filedest";
my $cmgr = $ssh->channel_mgr;
my $channel = $ssh->_session_channel;
$channel->open;
$channel->register_handler( SSH2_MSG_CHANNEL_OPEN_CONFIRMATION,
sub {
my ( $channel, $packet ) = @_;
$channel->{ssh}->debug("Sending command: $cmd");
my $r_packet = $channel->request_start( "exec", 0 );
$r_packet->put_str("$cmd");
$r_packet->send;
if (defined $size) {
$channel->send_data("C0644 $size $filesrc_invocation\n");
use constant CHUNK_SIZE => 8192;
while (read ($filehandle, my $chunk, CHUNK_SIZE)){
$channel->send_data($chunk);
$channel->drain_outgoing;
$channel->{istate} = CHAN_INPUT_WAIT_DRAIN;
}
$channel->send_eof;
$channel->{istate} = CHAN_INPUT_CLOSED;
}
}
);
..... You know what is next better than me ...
( $stdout, $stderr, $exit );
}
As you can see, it is bad. My chunk_size is not large enough to have a good
rate transfer. I didn't even know if there is some kind of negociation
between client and server. I have write only a small small ;) subset of the
scp protocol. It is a proof-of-concept prototype.
My questions are:
- I just see in the new 1.31 that there is a Subsystem generic call. Should I
use it for this piece of code.
- are you interested by this approach ? Is there something I don't see that
is not allowing such functions to work ?
- do you know where I can find a formal description of scp (I find openssh
code not very documented) ?
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