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

type[R]

The (integer) type of this packet.

Public Class Methods

new(payload) click to toggle source

Create a new packet from the given payload. This will automatically parse the packet if it is one that has been previously registered with ::register; otherwise, the packet will need to be manually parsed using the methods provided in the Net::SSH::Buffer superclass.

Calls superclass method Net::SSH::Buffer.new

# File lib/net/ssh/packet.rb, line 76
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 35
def self.register(type, *pairs)
  @@types[type] = pairs
end

Public Instance Methods

[](name) click to toggle source

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 85
def [](name)
  name = name.to_sym
  raise ArgumentError, "no such element #{name}" unless @named_elements.key?(name)
  @named_elements[name]
end