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require 'net/ssh/connection/constants'
require 'net/ssh/transport/constants'
module Net
module SSH
module Test
# This is an abstract class, not to be instantiated directly, subclassed by
# Net::SSH::Test::LocalPacket and Net::SSH::Test::RemotePacket. It implements
# functionality common to those subclasses.
#
# These packets are not true packets, in that they don't represent what was
# actually sent between the hosst; rather, they represent what was expected
# to be sent, as dictated by the script (Net::SSH::Test::Script). Thus,
# though they are defined with data elements, these data elements are used
# to either validate data that was sent by the local host (Net::SSH::Test::LocalPacket)
# or to mimic the sending of data by the remote host (Net::SSH::Test::RemotePacket).
class Packet
include Net::SSH::Transport::Constants
include Net::SSH::Connection::Constants
# Register a custom channel request. extra_parts is an array of types
# of extra parameters
def self.register_channel_request(request, extra_parts)
@registered_requests ||= {}
@registered_requests[request] = { extra_parts: extra_parts }
end
def self.registered_channel_requests(request)
@registered_requests && @registered_requests[request]
end
# Ceate a new packet of the given +type+, and with +args+ being a list of
# data elements in the order expected for packets of the given +type+
# (see #types).
def initialize(type, *args)
@type = self.class.const_get(type.to_s.upcase)
@data = args
end
# The default for +remote?+ is false. Subclasses should override as necessary.
def remote?
false
end
# The default for +local?+ is false. Subclasses should override as necessary.
def local?
false
end
# Instantiates the packets data elements. When the packet was first defined,
# some elements may not have been fully realized, and were described as
# Proc objects rather than atomic types. This invokes those Proc objects
# and replaces them with their returned values. This allows for values
# like Net::SSH::Test::Channel#remote_id to be used in scripts before
# the remote_id is known (since it is only known after a channel has been
# confirmed open).
def instantiate!
@data.map! { |i| i.respond_to?(:call) ? i.call : i }
end
# Returns an array of symbols describing the data elements for packets of
# the same type as this packet. These types are used to either validate
# sent packets (Net::SSH::Test::LocalPacket) or build received packets
# (Net::SSH::Test::RemotePacket).
#
# Not all packet types are defined here. As new packet types are required
# (e.g., a unit test needs to test that the remote host sent a packet that
# is not implemented here), the description of that packet should be
# added. Unsupported packet types will otherwise raise an exception.
def types
@types ||= case @type
when KEXINIT
%i[long long long long
string string string string string string string string string string
bool]
when NEWKEYS then []
when CHANNEL_OPEN then %i[string long long long]
when CHANNEL_OPEN_CONFIRMATION then %i[long long long long]
when CHANNEL_DATA then %i[long string]
when CHANNEL_EXTENDED_DATA then %i[long long string]
when CHANNEL_EOF, CHANNEL_CLOSE, CHANNEL_SUCCESS, CHANNEL_FAILURE then [:long]
when CHANNEL_REQUEST
parts = %i[long string bool]
case @data[1]
when "exec", "subsystem","shell" then parts << :string
when "exit-status" then parts << :long
when "pty-req" then parts.concat(%i[string long long long long string])
when "env" then parts.contact(%i[string string])
else
request = Packet.registered_channel_requests(@data[1])
raise "don't know what to do about #{@data[1]} channel request" unless request
parts.concat(request[:extra_parts])
end
else raise "don't know how to parse packet type #{@type}"
end
end
end
end
end
end
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