144 lines
4.0 KiB
Ruby
144 lines
4.0 KiB
Ruby
require 'ffi'
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require 'mach/functions'
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module Mach
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# Michael Weber's "Some Fun with Mach Ports" was an indispensable
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# resource in learning the Mach ports API.
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#
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# @see http://www.foldr.org/~michaelw/log/computers/macosx/task-info-fun-with-mach
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class Port
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include Functions
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class SendRightMsg < FFI::Struct
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include Functions
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layout(:header, MsgHeader,
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:body, MsgBody,
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:port, MsgPortDescriptor)
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end
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class ReceiveRightMsg < FFI::Struct
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include Functions
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layout(:header, MsgHeader,
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:body, MsgBody,
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:port, MsgPortDescriptor,
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:trailer, MsgTrailer)
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end
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attr_reader :ipc_space, :port
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# @param [Hash] opts
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#
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# @option opts [Integer] :ipc_space defaults to +mach_task_self+
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#
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# @option opts [MachPortRight] :right defaults to +:receive+
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#
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# @option opts [Port, Integer] :port if given, the existing port
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# is wrapped in a new Port object; otherwise a new port is
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# allocated according to the other options
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def initialize(opts = {})
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@ipc_space = opts[:ipc_space] || mach_task_self
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right = opts[:right] || :receive
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@port = if opts[:port]
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opts[:port].to_i
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else
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mem = new_memory_pointer(:mach_port_right_t)
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mach_port_allocate(@ipc_space.to_i, right, mem)
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mem.get_uint(0)
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end
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end
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# With this alias, we can call #to_i on either bare Integer ports
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# or wrapped Port objects when passing the arg to a foreign
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# function.
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alias_method :to_i, :port
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def to_s
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"#<#{self.class} #{to_i}>"
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end
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def ==(other)
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(port == other.port) && (ipc_space == other.ipc_space)
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end
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def destroy(opts = {})
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ipc_space = opts[:ipc_space] || @ipc_space
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mach_port_destroy(ipc_space, @port)
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end
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def deallocate(opts = {})
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ipc_space = opts[:ipc_space] || @ipc_space
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mach_port_deallocate(ipc_space.to_i, @port)
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end
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# Insert +right+ into another ipc space. The current task must
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# have sufficient rights to insert the requested right.
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#
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# @param [MsgType] right
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#
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# @param [Hash] opts
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#
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# @option opts [Port,Integer] :ipc_space the space (task port) into which
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# +right+ will be inserted; defaults to this port's ipc_space
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#
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# @option opts [Port,Integer] :port the name the port right should
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# have in :ipc_space; defaults to the same name as this port
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def insert_right(right, opts = {})
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ipc_space = opts[:ipc_space] || @ipc_space
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port_name = opts[:port_name] || @port
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mach_port_insert_right(ipc_space.to_i, port_name.to_i, @port, right)
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end
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# Send +right+ on this Port to +remote_port+. The current task
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# must already have the requisite rights allowing it to send
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# +right+.
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def send_right(right, remote_port)
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msg = SendRightMsg.new
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msg[:header].tap do |h|
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h[:remote_port] = remote_port.to_i
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h[:local_port] = PORT_NULL
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h[:bits] =
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(MsgType[right] | (0 << 8)) | 0x80000000 # MACH_MSGH_BITS_COMPLEX
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h[:size] = 40 # msg.size
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end
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msg[:body][:descriptor_count] = 1
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msg[:port].tap do |p|
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p[:name] = port
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p[:disposition] = MsgType[right]
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p[:type] = 0 # MSG_PORT_DESCRIPTOR;
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end
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mach_msg_send msg
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end
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# Copy the send right on this port and send it in a message to
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# +remote_port+. The current task must have an existing send
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# right on this Port.
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def copy_send(remote_port)
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send_right(:copy_send, remote_port)
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end
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# Create a new Port by receiving a port right message on this
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# port.
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def receive_right
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msg = ReceiveRightMsg.new
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mach_msg(msg,
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2, # RCV_MSG,
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0,
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msg.size,
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port,
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MSG_TIMEOUT_NONE,
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PORT_NULL)
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self.class.new :port => msg[:port][:name]
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end
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end
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end
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