Current File : //opt/cpanel/ea-ruby27/root/usr/share/passenger/phusion_passenger/message_channel.rb
# encoding: binary
# Phusion Passenger - https://www.phusionpassenger.com/
# Copyright (c) 2010-2018 Phusion Holding B.V.
#
# "Passenger", "Phusion Passenger" and "Union Station" are registered
# trademarks of Phusion Holding B.V.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
module PhusionPassenger
# This class allows reading and writing structured messages over
# I/O channels. This is the Ruby implementation of src/cxx_supportlib/IOTools/MessageIO.h;
# see that file for more information.
class MessageChannel
HEADER_SIZE = 2 # :nodoc:
DELIMITER = "\0" # :nodoc:
DELIMITER_NAME = "null byte" # :nodoc:
UINT16_PACK_FORMAT = "n" # :nodoc:
UINT32_PACK_FORMAT = "N" # :nodoc:
class InvalidHashError < StandardError
end
# The wrapped IO object.
attr_accessor :io
# Create a new MessageChannel by wrapping the given IO object.
def initialize(io = nil)
@io = io
# Make it binary just in case.
@io.binmode if @io
end
# Read an array message from the underlying file descriptor.
# Returns the array message as an array, or nil when end-of-stream has
# been reached.
#
# Might raise SystemCallError, IOError or SocketError when something
# goes wrong.
def read
buffer = new_buffer
if !@io.read(HEADER_SIZE, buffer)
return nil
end
while buffer.size < HEADER_SIZE
tmp = @io.read(HEADER_SIZE - buffer.size)
if tmp.empty?
return nil
else
buffer << tmp
end
end
chunk_size = buffer.unpack(UINT16_PACK_FORMAT)[0]
if !@io.read(chunk_size, buffer)
return nil
end
while buffer.size < chunk_size
tmp = @io.read(chunk_size - buffer.size)
if tmp.empty?
return nil
else
buffer << tmp
end
end
message = []
offset = 0
delimiter_pos = buffer.index(DELIMITER, offset)
while !delimiter_pos.nil?
if delimiter_pos == 0
message << ""
else
message << buffer[offset .. delimiter_pos - 1]
end
offset = delimiter_pos + 1
delimiter_pos = buffer.index(DELIMITER, offset)
end
return message
rescue Errno::ECONNRESET
return nil
end
# Read an array message from the underlying file descriptor and return the
# result as a hash instead of an array. This assumes that the array message
# has an even number of elements.
# Returns nil when end-of-stream has been reached.
#
# Might raise SystemCallError, IOError or SocketError when something
# goes wrong.
def read_hash
buffer = new_buffer
if !@io.read(HEADER_SIZE, buffer)
return nil
end
while buffer.size < HEADER_SIZE
tmp = @io.read(HEADER_SIZE - buffer.size)
if tmp.empty?
return nil
else
buffer << tmp
end
end
chunk_size = buffer.unpack(UINT16_PACK_FORMAT)[0]
if !@io.read(chunk_size, buffer)
return nil
end
while buffer.size < chunk_size
tmp = @io.read(chunk_size - buffer.size)
if tmp.empty?
return nil
else
buffer << tmp
end
end
result = {}
offset = 0
delimiter_pos = buffer.index(DELIMITER, offset)
while !delimiter_pos.nil?
if delimiter_pos == 0
name = ""
else
name = buffer[offset .. delimiter_pos - 1]
end
offset = delimiter_pos + 1
delimiter_pos = buffer.index(DELIMITER, offset)
if delimiter_pos.nil?
raise InvalidHashError
elsif delimiter_pos == 0
value = ""
else
value = buffer[offset .. delimiter_pos - 1]
end
result[name] = value
offset = delimiter_pos + 1
delimiter_pos = buffer.index(DELIMITER, offset)
end
return result
rescue Errno::ECONNRESET
return nil
end
# Read a scalar message from the underlying IO object. Returns the
# read message, or nil on end-of-stream.
#
# Might raise SystemCallError, IOError or SocketError when something
# goes wrong.
#
# The +buffer+ argument specifies a buffer in which #read_scalar
# stores the read data. It is good practice to reuse existing buffers
# in order to minimize stress on the garbage collector.
#
# The +max_size+ argument allows one to specify the maximum allowed
# size for the scalar message. If the received scalar message's size
# is larger than +max_size+, then a SecurityError will be raised.
def read_scalar(buffer = new_buffer, max_size = nil)
if !@io.read(4, buffer)
return nil
end
while buffer.size < 4
tmp = @io.read(4 - buffer.size)
if tmp.empty?
return nil
else
buffer << tmp
end
end
size = buffer.unpack(UINT32_PACK_FORMAT)[0]
if size == 0
buffer.replace('')
return buffer
else
if !max_size.nil? && size > max_size
raise SecurityError, "Scalar message size (#{size}) " <<
"exceeds maximum allowed size (#{max_size})."
end
if !@io.read(size, buffer)
return nil
end
if buffer.size < size
tmp = ''
while buffer.size < size
if !@io.read(size - buffer.size, tmp)
return nil
else
buffer << tmp
end
end
end
return buffer
end
rescue Errno::ECONNRESET
return nil
end
# Send an array message, which consists of the given elements, over the underlying
# file descriptor. _name_ is the first element in the message, and _args_ are the
# other elements. These arguments will internally be converted to strings by calling
# to_s().
#
# Might raise SystemCallError, IOError or SocketError when something
# goes wrong.
def write(name, *args)
check_argument(name)
args.each do |arg|
check_argument(arg)
end
message = "#{name}#{DELIMITER}"
args.each do |arg|
message << arg.to_s << DELIMITER
end
if message.size > 2 ** 16 - 1
raise ArgumentError, 'Message size too large'
end
@io.write([message.size].pack('n') << message)
@io.flush
end
# Send a scalar message over the underlying IO object.
#
# Might raise SystemCallError, IOError or SocketError when something
# goes wrong.
def write_scalar(data)
@io.write([data.size].pack('N') << data)
@io.flush
end
# Receive an IO object (a file descriptor) from the channel. The other
# side must have sent an IO object by calling send_io(). Note that
# this only works on Unix sockets.
#
# Might raise SystemCallError, IOError or SocketError when something
# goes wrong.
def recv_io(klass = IO, negotiate = true)
write("pass IO") if negotiate
io = @io.recv_io(klass)
write("got IO") if negotiate
return io
end
# Send an IO object (a file descriptor) over the channel. The other
# side must receive the IO object by calling recv_io(). Note that
# this only works on Unix sockets.
#
# Might raise SystemCallError, IOError or SocketError when something
# goes wrong.
def send_io(io)
# We read a message before actually calling #send_io
# in order to prevent the other side from accidentally
# read()ing past the normal data and reading our file
# descriptor too.
#
# For example suppose that side A looks like this:
#
# read(fd, buf, 1024)
# read_io(fd)
#
# and side B:
#
# write(fd, buf, 100)
# send_io(fd_to_pass)
#
# If B completes both write() and send_io(), then A's read() call
# reads past the 100 bytes that B sent. On some platforms, like
# Linux, this will cause read_io() to fail. And it just so happens
# that Ruby's IO#read method slurps more than just the given amount
# of bytes.
result = read
if !result
raise EOFError, "End of stream"
elsif result != ["pass IO"]
raise IOError, "IO passing pre-negotiation header expected"
else
@io.send_io(io)
# Once you've sent the IO you expect to be able to close it on the
# sender's side, even if the other side hasn't read the IO yet.
# Not so: on some operating systems (I'm looking at you OS X) this
# can cause the receiving side to receive a bad file descriptor.
# The post negotiation protocol ensures that we block until the
# other side has really received the IO.
result = read
if !result
raise EOFError, "End of stream"
elsif result != ["got IO"]
raise IOError, "IO passing post-negotiation header expected"
end
end
end
# Return the file descriptor of the underlying IO object.
def fileno
return @io.fileno
end
# Close the underlying IO stream. Might raise SystemCallError or
# IOError when something goes wrong.
def close
@io.close
end
# Checks whether the underlying IO stream is closed.
def closed?
return @io.closed?
end
private
def check_argument(arg)
if arg.to_s.index(DELIMITER)
raise ArgumentError, "Message name and arguments may not contain #{DELIMITER_NAME}."
end
end
if defined?(ByteString)
def new_buffer
return ByteString.new
end
else
def new_buffer
return ""
end
end
end
end # module PhusionPassenger
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