Class: LDAP::Server::Connection

Inherits:
Object
  • Object
show all
Defined in:
lib/ldap/server/connection.rb

Overview

An object which handles an LDAP connection. Note that LDAP allows requests and responses to be exchanged asynchronously: e.g. a client can send three requests, and the three responses can come back in any order. For that reason, we start a new thread for each request, and we need a mutex on the io object so that multiple responses don’t interfere with each other.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(io, opt = {}) ⇒ Connection

Returns a new instance of Connection.



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# File 'lib/ldap/server/connection.rb', line 18

def initialize(io, opt={})
  @io = io
  @opt = opt
  @mutex = Mutex.new
  @active_reqs = {}   # map message ID to thread object
  @binddn = nil
  @version = 3
  @logger = @opt[:logger] || $stderr
  @ssl = false

  startssl if @opt[:ssl_on_connect]
end

Instance Attribute Details

#binddn ⇒ Object (readonly)

Returns the value of attribute binddn.



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# File 'lib/ldap/server/connection.rb', line 16

def binddn
  @binddn
end

#opt ⇒ Object (readonly)

Returns the value of attribute opt.



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# File 'lib/ldap/server/connection.rb', line 16

def opt
  @opt
end

#version ⇒ Object (readonly)

Returns the value of attribute version.



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# File 'lib/ldap/server/connection.rb', line 16

def version
  @version
end

Instance Method Details

#abandon(messageID) ⇒ Object 



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# File 'lib/ldap/server/connection.rb', line 224

def abandon(messageID)
  @mutex.synchronize do
    thread = @active_reqs.delete(messageID)
    thread.raise LDAP::Abandon if thread and thread.alive?
  end
end

#abandon_all ⇒ Object 



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# File 'lib/ldap/server/connection.rb', line 231

def abandon_all
  return if @active_reqs.size == 0
  @mutex.synchronize do
    @active_reqs.each do |id, thread|
      thread.raise LDAP::Abandon if thread.alive?
    end
    @active_reqs = {}
  end
end

#ber_read(io) ⇒ Object

Read one ASN1 element from the given stream. Return String containing the raw element.



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# File 'lib/ldap/server/connection.rb', line 49

def ber_read(io)
  blk = io.read(2)		# minimum: short tag, short length
  throw(:close) if blk.nil?
  tag = blk[0] & 0x1f
  len = blk[1]

  if tag == 0x1f		# long form
    tag = 0
    while true
      ch = io.getc
      blk << ch
      tag = (tag << 7) | (ch & 0x7f)
      break if (ch & 0x80) == 0
    end
    len = io.getc
    blk << len
  end

  if (len & 0x80) != 0	# long form
    len = len & 0x7f
    raise LDAP::ResultError::ProtocolError, "Indefinite length encoding not supported" if len == 0
    offset = blk.length
    blk << io.read(len)
    # is there a more efficient way of doing this?
    len = 0
    blk[offset..-1].each_byte { |b| len = (len << 8) | b }
  end

  offset = blk.length
  blk << io.read(len)
  return blk
  # or if we wanted to keep the partial decoding we've done:
  # return blk, [blk[0] >> 6, tag], offset
end

#handle_requests ⇒ Object 



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# File 'lib/ldap/server/connection.rb', line 84

def handle_requests
  operationClass = @opt[:operation_class]
  ocArgs = @opt[:operation_args] || []
  catch(:close) do
    while true
      begin
        blk = ber_read(@io)
        asn1 = OpenSSL::ASN1::decode(blk)
        # Debugging:
        # puts "Request: #{blk.unpack("H*")}\n#{asn1.inspect}" if $debug

        raise LDAP::ResultError::ProtocolError, "LDAPMessage must be SEQUENCE" unless asn1.is_a?(OpenSSL::ASN1::Sequence)
        raise LDAP::ResultError::ProtocolError, "Bad Message ID" unless asn1.value[0].is_a?(OpenSSL::ASN1::Integer)
        messageId = asn1.value[0].value

        protocolOp = asn1.value[1]
        raise LDAP::ResultError::ProtocolError, "Bad protocolOp" unless protocolOp.is_a?(OpenSSL::ASN1::ASN1Data)
        raise LDAP::ResultError::ProtocolError, "Bad protocolOp tag class" unless protocolOp.tag_class == :APPLICATION

        # controls are not properly implemented
        c = asn1.value[2]
        if c.is_a?(OpenSSL::ASN1::ASN1Data) and c.tag_class == :APPLICATION and c.tag == 0
          controls = c.value
        end

        case protocolOp.tag
        when 0 # BindRequest
          abandon_all
          @binddn, @version = operationClass.new(self,messageId,*ocArgs).
                              do_bind(protocolOp, controls)

        when 2 # UnbindRequest
          throw(:close)

        when 3 # SearchRequest
          # Note: RFC 2251 4.4.4.1 says behaviour is undefined if
          # client sends an overlapping request with same message ID,
          # so we don't have to worry about the case where there is
          # already a thread with this id in @active_reqs.
          # However, to avoid a race we copy messageId/
          # protocolOp/controls into thread-local variables, because
          # they will change when the next request comes in.
          #
          # There is a theoretical race condition here: a client could
          # send an abandon request before Thread.current is assigned to
          # @active_reqs[thrm]. It's not a problem, because abandon isn't
          # guaranteed to work anyway. Doing it this way ensures that
          # @active_reqs does not leak memory on a long-lived connection.

          Thread.new(messageId,protocolOp,controls) do |thrm,thrp,thrc|
            begin
              @active_reqs[thrm] = Thread.current
              operationClass.new(self,thrm,*ocArgs).do_search(thrp, thrc)
            ensure
              @active_reqs.delete(thrm)
            end
          end

        when 6 # ModifyRequest
          Thread.new(messageId,protocolOp,controls) do |thrm,thrp,thrc|
            begin
              @active_reqs[thrm] = Thread.current
              operationClass.new(self,thrm,*ocArgs).do_modify(thrp, thrc)
            ensure
              @active_reqs.delete(thrm)
            end
          end

        when 8 # AddRequest
          Thread.new(messageId,protocolOp,controls) do |thrm,thrp,thrc|
            begin
              @active_reqs[thrm] = Thread.current
              operationClass.new(self,thrm,*ocArgs).do_add(thrp, thrc)
            ensure
              @active_reqs.delete(thrm)
            end
          end

        when 10 # DelRequest
          Thread.new(messageId,protocolOp,controls) do |thrm,thrp,thrc|
            begin
              @active_reqs[thrm] = Thread.current
              operationClass.new(self,thrm,*ocArgs).do_del(thrp, thrc)
            ensure
              @active_reqs.delete(thrm)
            end
          end

        when 12 # ModifyDNRequest
          Thread.new(messageId,protocolOp,controls) do |thrm,thrp,thrc|
            begin
              @active_reqs[thrm] = Thread.current
              operationClass.new(self,thrm,*ocArgs).do_modifydn(thrp, thrc)
            ensure
              @active_reqs.delete(thrm)
            end
          end

        when 14 # CompareRequest
          Thread.new(messageId,protocolOp,controls) do |thrm,thrp,thrc|
            begin
              @active_reqs[thrm] = Thread.current
              operationClass.new(self,thrm,*ocArgs).do_compare(thrp, thrc)
            ensure
              @active_reqs.delete(thrm)
            end
          end

        when 16 # AbandonRequest
          abandon(protocolOp.value)

        else
          raise LDAP::ResultError::ProtocolError, "Unrecognised protocolOp tag #{protocolOp.tag}"
        end

      rescue LDAP::ResultError::ProtocolError, OpenSSL::ASN1::ASN1Error => e
        send_notice_of_disconnection(LDAP::ResultError::ProtocolError.new.to_i, e.message)
        throw(:close)

      # all other exceptions propagate up and are caught by tcpserver
      end
    end
  end
  abandon_all
end

#log(msg) ⇒ Object 



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# File 'lib/ldap/server/connection.rb', line 31

def log(msg)
  @logger << "[#{@io.peeraddr[3]}]: #{msg}\n"
end

#send_notice_of_disconnection(resultCode, errorMessage = "") ⇒ Object 



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# File 'lib/ldap/server/connection.rb', line 265

def send_notice_of_disconnection(resultCode, errorMessage="")
  send_unsolicited_notification(resultCode,
    :errorMessage=>errorMessage,
    :responseName=>"1.3.6.1.4.1.1466.20036"
  )
end

#send_unsolicited_notification(resultCode, opt = {}) ⇒ Object 



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# File 'lib/ldap/server/connection.rb', line 241

def send_unsolicited_notification(resultCode, opt={})
  protocolOp = [
    OpenSSL::ASN1::Enumerated(resultCode),
    OpenSSL::ASN1::OctetString(opt[:matchedDN] || ""),
    OpenSSL::ASN1::OctetString(opt[:errorMessage] || ""),
  ]
  if opt[:referral]
    rs = opt[:referral].collect { |r| OpenSSL::ASN1::OctetString(r) }
    protocolOp << OpenSSL::ASN1::Sequence(rs, 3, :IMPLICIT, :APPLICATION)
  end
  if opt[:responseName]
    protocolOp << OpenSSL::ASN1::OctetString(opt[:responseName], 10, :IMPLICIT, :APPLICATION)
  end
  if opt[:response]
    protocolOp << OpenSSL::ASN1::OctetString(opt[:response], 11, :IMPLICIT, :APPLICATION)
  end
  message = [
    OpenSSL::ASN1::Integer(0),
    OpenSSL::ASN1::Sequence(protocolOp, 24, :IMPLICIT, :APPLICATION),
  ]
  message << opt[:controls] if opt[:controls]
  write(OpenSSL::ASN1::Sequence(message).to_der)
end

#startssl ⇒ Object

:yields:



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# File 'lib/ldap/server/connection.rb', line 35

def startssl # :yields:
  @mutex.synchronize do
    raise LDAP::ResultError::OperationsError if @ssl or @active_reqs.size > 0
    yield if block_given?
    @io = OpenSSL::SSL::SSLSocket.new(@io, @opt[:ssl_ctx])
    @io.sync_close = true
    @io.accept
    @ssl = true
  end
end

#write(data) ⇒ Object 



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# File 'lib/ldap/server/connection.rb', line 210

def write(data)
  @mutex.synchronize do
    @io.write(data)
    @io.flush
  end
end

#writelock ⇒ Object 



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# File 'lib/ldap/server/connection.rb', line 217

def writelock
  @mutex.synchronize do
    yield @io
    @io.flush
  end
end