Class: FTW::Connection

Inherits:
Object
  • Object
show all
Includes:
Cabin::Inspectable, Poolable
Defined in:
lib/ftw/connection.rb

Overview

A network connection. This is TCP.

You can use IO::select on this objects of this type. (at least, in MRI you can)

You can activate SSL/TLS on this connection by invoking FTW::Connection#secure

This class also implements buffering itself because some IO-like classes (OpenSSL::SSL::SSLSocket) do not support IO#ungetbyte

Defined Under Namespace

Classes: ConnectRefused, ConnectTimeout, ReadTimeout, SecureHandshakeTimeout, WriteTimeout

Instance Method Summary collapse

Methods included from Poolable

#available?, #mark, #release

Instance Method Details

#client? ⇒ Boolean

Is this a client connection?

Returns:

  • (Boolean) 


406
407
408
 
# File 'lib/ftw/connection.rb', line 406

def client?
  return @mode == :client
end

#connect(timeout = nil) ⇒ nil, StandardError or subclass

Connect now.

Timeout value is optional. If no timeout is given, this method blocks until a connection is successful or an error occurs.

You should check the return value of this method to determine if a connection was successful.

Possible return values are on error include:

  • FTW::Connection::ConnectRefused

  • FTW::Connection::ConnectTimeout

Returns:

  • (nil) —

    if the connection was successful

  • (StandardError or subclass) —

    if the connection failed



129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
 
# File 'lib/ftw/connection.rb', line 129

def connect(timeout=nil)
  # TODO(sissel): Raise if we're already connected?
  disconnect("reconnecting") if connected?
  host, port = @destinations.first.split(":")
  @destinations = @destinations.rotate # round-robin

  # Do dns resolution on the host. If there are multiple
  # addresses resolved, return one at random.
  addresses = FTW::DNS.singleton.resolve(host)

  addresses.each do |address|
    # Try each address until one works.
    @remote_address = address
    # Addresses with colon ':' in them are assumed to be IPv6
    family = @remote_address.include?(":") ? Socket::AF_INET6 : Socket::AF_INET
    @logger.debug("Connecting", :address => @remote_address,
                  :host => host, :port => port, :family => family)
    @socket = Socket.new(family, Socket::SOCK_STREAM, 0)
    @socket.setsockopt(Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1)

    # This api is terrible. pack_sockaddr_in? This isn't C, man...
    @logger.debug("packing", :data => [port.to_i, @remote_address])
    sockaddr = Socket.pack_sockaddr_in(port.to_i, @remote_address)
    # TODO(sissel): Support local address binding

    # Connect with timeout
    begin
      @socket.connect_nonblock(sockaddr)
    rescue IO::WaitWritable, Errno::EINPROGRESS
      # Ruby actually raises Errno::EINPROGRESS, but for some reason
      # the documentation says to use this IO::WaitWritable thing...
      # I don't get it, but whatever :(

      writable = writable?(timeout)

      # http://jira.codehaus.org/browse/JRUBY-6528; IO.select doesn't behave
      # correctly on JRuby < 1.7, so work around it.
      if writable || (RUBY_PLATFORM == "java" and JRUBY_VERSION < "1.7.0")
        begin
          @socket.connect_nonblock(sockaddr) # check connection failure
        rescue Errno::EISCONN 
          # Ignore, we're already connected.
        rescue Errno::ECONNREFUSED => e
          # Fire 'disconnected' event with reason :refused
          @socket.close
          return ConnectRefused.new("#{host}[#{@remote_address}]:#{port}")
        rescue Errno::ETIMEDOUT
          # This occurs when the system's TCP timeout hits, we have no
          # control over this, as far as I can tell. *maybe* setsockopt(2)
          # has a flag for this, but I haven't checked..
          # TODO(sissel): We should instead do 'retry' unless we've exceeded
          # the timeout.
          @socket.close
          return ConnectTimeout.new("#{host}[#{@remote_address}]:#{port}")
        rescue Errno::EINPROGRESS
          # If we get here, it's likely JRuby version < 1.7.0. EINPROGRESS at
          # this point in the code means that we have timed out.
          @socket.close
          return ConnectTimeout.new("#{host}[#{@remote_address}]:#{port}")
        end
      else
        # Connection timeout;
        return ConnectTimeout.new("#{host}[#{@remote_address}]:#{port}")
      end

      # If no error at this point, we're now connected.
      @connected = true
      break
    end # addresses.each
  end 
  return nil
end

#connected? ⇒ Boolean

Is this Connection connected?

Returns:

  • (Boolean) 


203
204
205
 
# File 'lib/ftw/connection.rb', line 203

def connected?
  return @connected
end

#disconnect(reason) ⇒ Object

End this connection, specifying why.



264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
 
# File 'lib/ftw/connection.rb', line 264

def disconnect(reason)
  if @socket.is_a?(OpenSSL::SSL::SSLSocket)
    @socket.sysclose()
  else
    begin 
      @socket.close_read
    rescue IOError => e
      # Ignore, perhaps we shouldn't ignore.
    end

    begin 
      @socket.close_write
    rescue IOError => e
      # Ignore, perhaps we shouldn't ignore.
    end
  end
end

#peer ⇒ Object

The host:port



301
302
303
 
# File 'lib/ftw/connection.rb', line 301

def peer
  return @remote_address
end

#pushback(data) ⇒ Object

Push back some data onto the connection’s read buffer.



259
260
261
 
# File 'lib/ftw/connection.rb', line 259

def pushback(data)
  @pushback_buffer << data
end

#read(length = 16384, timeout = nil) ⇒ Object

Read data from this connection This method blocks until the read succeeds unless a timeout is given.

This method is not guaranteed to read exactly ‘length’ bytes. See IO#sysread



227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
 
# File 'lib/ftw/connection.rb', line 227

def read(length=16384, timeout=nil)
  data = ""
  data.force_encoding("BINARY") if data.respond_to?(:force_encoding)
  have_pushback = !@pushback_buffer.empty?
  if have_pushback
    data << @pushback_buffer
    @pushback_buffer = ""
    # We have data 'now' so don't wait.
    timeout = 0
  end

  if readable?(timeout)
    begin
      # Read at most 'length' data, so read less from the socket
      # We'll read less than 'length' if the pushback buffer has
      # data in it already.
      @socket.sysread(length - data.length, @read_buffer)
      data << @read_buffer
      return data
    rescue EOFError => e
      raise e
    end
  else
    if have_pushback
      return data
    else
      raise ReadTimeout.new
    end
  end
end

#readable?(timeout) ⇒ Boolean

Is this connection readable? Returns true if it is readable within the timeout period. False otherwise.

The time out is in seconds. Fractional seconds are OK.

Returns:

  • (Boolean) 


295
296
297
298
 
# File 'lib/ftw/connection.rb', line 295

def readable?(timeout)
  readable, writable, errors = IO.select([@socket], nil, nil, timeout)
  return !readable.nil?
end

#secure(options = nil) ⇒ Object

Secure this connection with TLS.

Options:

  • :certificate_store, an OpenSSL::X509::Store

  • :timeout, a timeout threshold in seconds.



316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
 
# File 'lib/ftw/connection.rb', line 316

def secure(options=nil)
  # Skip this if we're already secure.
  return if secured?

  defaults = {
    :timeout => nil,
    #:certificate_store => OpenSSL::SSL::SSLContext::DEFAULT_CERT_STORE
  }
  settings = defaults.merge(options) unless options.nil?

  @logger.info("Securing this connection", :peer => peer, :options => settings)
  # Wrap this connection with TLS/SSL
  sslcontext = OpenSSL::SSL::SSLContext.new
  # If you use VERIFY_NONE, you are removing the trust feature of TLS. Don't do that.
  # Encryption without trust means you don't know who you are talking to.
  sslcontext.verify_mode = OpenSSL::SSL::VERIFY_PEER
  sslcontext.verify_callback = proc do |*args| 
    @logger.debug("Verify peer via FTW::Connection#secure", :callback => settings[:verify_callback])
    if settings[:verify_callback].respond_to?(:call)
      settings[:verify_callback].call(*args)
    end
  end
  sslcontext.ssl_version = :TLSv1
  sslcontext.cert_store = options[:certificate_store]
  @socket = OpenSSL::SSL::SSLSocket.new(@socket, sslcontext)

  # TODO(sissel): Set up local certificat/key stuff. This is required for
  # server-side ssl operation, I think.

  if client?
    do_secure(:connect_nonblock, options[:timeout])
  else
    do_secure(:accept_nonblock, options[:timeout])
  end
end

#secured? ⇒ Boolean

Has this connection been secured?

Returns:

  • (Boolean) 


401
402
403
 
# File 'lib/ftw/connection.rb', line 401

def secured?
  return @secure
end

#server? ⇒ Boolean

Is this a server connection?

Returns:

  • (Boolean) 


411
412
413
 
# File 'lib/ftw/connection.rb', line 411

def server?
  return @mode == :server
end

#to_io ⇒ Object

Support ‘to_io’ so you can use IO::select on this object.



306
307
308
 
# File 'lib/ftw/connection.rb', line 306

def to_io
  return @socket
end

#writable?(timeout) ⇒ Boolean

Is this connection writable? Returns true if it is writable within the timeout period. False otherwise.

The time out is in seconds. Fractional seconds are OK.

Returns:

  • (Boolean) 


286
287
288
289
 
# File 'lib/ftw/connection.rb', line 286

def writable?(timeout)
  readable, writable, errors = IO.select(nil, [@socket], nil, timeout)
  return !writable.nil?
end

#write(data, timeout = nil) ⇒ Object

Write data to this connection. This method blocks until the write succeeds unless a timeout is given.

This method is not guaranteed to have written the full data given.

Returns the number of bytes written (See also IO#syswrite)



213
214
215
216
217
218
219
220
 
# File 'lib/ftw/connection.rb', line 213

def write(data, timeout=nil)
  #connect if !connected?
  if writable?(timeout)
    return @socket.syswrite(data)
  else
    raise FTW::Connection::WriteTimeout.new(self.inspect)
  end
end