Net::SSH::Perl::PacketUser Contributed Perl DocumentaNet::SSH::Perl::Packet(3)NAMENet::SSH::Perl::Packet - Packet layer of SSH protocol
SYNOPSIS
use Net::SSH::Perl::Packet;
# Send a packet to an ssh daemon.
my $pack = Net::SSH::Perl::Packet->new($ssh, type => SSH_MSG_NONE);
$pack->send;
# Receive a packet.
my $pack = Net::SSH::Perl::Packet->read($ssh);
DESCRIPTIONNet::SSH::Perl::Packet implements the packet-layer piece of the SSH
protocol. Messages between server and client are sent as binary data
packets, which are encrypted (once the two sides have agreed on the
encryption cipher, that is).
Packets are made up primarily of a packet type, which describes the
type of message and data contained therein, and the data itself. In
addition, each packet: indicates its length in a 32-bit unsigned
integer; contains padding to pad the length of the packet to a multiple
of 8 bytes; and is verified by a 32-bit crc checksum.
Refer to the SSH RFC for more details on the packet protocol and the
SSH protocol in general.
USAGE
Net::SSH::Perl::Packet->new($ssh, %params)
Creates/starts a new packet in memory. $ssh is a Net::SSH::Perl object,
which should already be connected to an ssh daemon. %params can contain
the following keys:
· type
The message type of this packet. This should be one of the values
exported by Net::SSH::Perl::Constants from the msg tag; for
example, SSH_MSG_NONE.
· data
A Net::SSH::Perl::Buffer object containing the data in this packet.
Realistically, there aren't many times you'll need to supply this
argument: when sending a packet, it will be created automatically;
and when receiving a packet, the read method (see below) will
create the buffer automatically, as well.
Net::SSH::Perl::Packet->read($ssh)
Reads a packet from the ssh daemon and returns that packet.
This method will block until an entire packet has been read. The
socket itself is non-blocking, but the method waits (using select) for
data on the incoming socket, then processes that data when it comes in.
If the data makes up a complete packet, the packet is returned to the
caller. Otherwise read continues to try to read more data.
Net::SSH::Perl::Packet->read_poll($ssh)
Checks the data that's been read from the sshd to see if that data
comprises a complete packet. If so, that packet is returned. If not,
returns "undef".
This method does not block.
Net::SSH::Perl::Packet->read_expect($ssh, $type)
Reads the next packet from the daemon and dies if the packet type does
not match $type. Otherwise returns the read packet.
$packet->send([ $data ])
Sends a packet to the ssh daemon. $data is optional, and if supplied
specifies the buffer to be sent in the packet (should be a
Net::SSH::Perl::Buffer object). In addition, $data, if specified, must
include the packed message type.
If $data is not specified, send sends the buffer internal to the
packet, which you've presumably filled by calling the put_* methods
(see below).
$packet->type
Returns the message type of the packet $packet.
$packet->data
Returns the message buffer from the packet $packet; a
Net::SSH::Perl::Buffer object.
Net::SSH::Perl::Buffer methods
Calling methods from the Net::SSH::Perl::Buffer class on your
Net::SSH::Perl::Packet object will automatically invoke those methods
on the buffer object internal to your packet object (which is created
when your object is constructed). For example, if you executed the
following code:
my $packet = Net::SSH::Perl::Packet->new($ssh, type => SSH_CMSG_USER);
$packet->put_str($user);
this would construct a new packet object $packet, then fill its
internal buffer by calling the put_str method on it.
Refer to the Net::SSH::Perl::Buffer documentation (the GET AND PUT
METHODS section) for more details on those methods.
AUTHOR & COPYRIGHTS
Please see the Net::SSH::Perl manpage for author, copyright, and
license information.
perl v5.14.1 2008-09-24 Net::SSH::Perl::Packet(3)
