class Net::SSH::Packet
A specialization of Buffer
that knows the format of certain common packet types. It auto-parses those packet types, and allows them to be accessed via the []
accessor.
data = some_channel_request_packet packet = Net::SSH::Packet.new(data) p packet.type #-> 98 (CHANNEL_REQUEST) p packet[:request] p packet[:want_reply]
This is used exclusively internally by Net::SSH
, and unless you’re doing protocol-level manipulation or are extending Net::SSH
in some way, you’ll never need to use this class directly.
Attributes
The (integer) type of this packet.
Public Class Methods
Create a new packet from the given payload. This will automatically parse the packet if it is one that has been previously registered with Packet.register
; otherwise, the packet will need to be manually parsed using the methods provided in the Net::SSH::Buffer
superclass.
Net::SSH::Buffer::new
# File lib/net/ssh/packet.rb, line 75 def initialize(payload) @named_elements = {} super @type = read_byte instantiate! end
Register a new packet type that should be recognized and auto-parsed by Net::SSH::Packet
. Note that any packet type that is not preregistered will not be autoparsed.
The pairs
parameter must be either empty, or an array of two-element tuples, where the first element of each tuple is the name of the field, and the second is the type.
register DISCONNECT, [:reason_code, :long], [:description, :string], [:language, :string]
# File lib/net/ssh/packet.rb, line 34 def self.register(type, *pairs) @@types[type] = pairs end
Public Instance Methods
Access one of the auto-parsed fields by name. Raises an error if no element by the given name exists.
# File lib/net/ssh/packet.rb, line 84 def [](name) name = name.to_sym raise ArgumentError, "no such element #{name}" unless @named_elements.key?(name) @named_elements[name] end
Private Instance Methods
Parse the packet’s contents and assign the named elements, as described by the registered format for the packet.
# File lib/net/ssh/packet.rb, line 95 def instantiate! (@@types[type] || []).each do |name, datatype| @named_elements[name.to_sym] = if datatype == :buffer remainder_as_buffer else send("read_#{datatype}") end end end