Class Net::SSH::Packet

  1. lib/net/ssh/packet.rb

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.

Methods

public class

  1. new
  2. register

public instance

  1. []

Attributes

type [R] The (integer) type of this packet.

Public class methods

new (payload)

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.

[show source]
    # File lib/net/ssh/packet.rb, line 73
73:     def initialize(payload)
74:       @named_elements = {}
75:       super
76:       @type = read_byte
77:       instantiate!
78:     end
register (type, *pairs)

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]
[show source]
    # File lib/net/ssh/packet.rb, line 34
34:     def self.register(type, *pairs)
35:       @@types[type] = pairs
36:     end

Public instance methods

[] (name)

Access one of the auto-parsed fields by name. Raises an error if no element by the given name exists.

[show source]
    # File lib/net/ssh/packet.rb, line 82
82:     def [](name)
83:       name = name.to_sym
84:       raise ArgumentError, "no such element #{name}" unless @named_elements.key?(name)
85:       @named_elements[name]
86:     end