Dynamic Source Routing

Requirements: The client will send a DSR fixed header with a Route Request option but with
only the target address sent. The server will reply by setting its own address also into
the header. Accept from user as command line argument how many messages should be sent from client to server. For every message, accept target address from the user.

Also, accept the server IP address as a command line argument.

Fixed Portion of DSR Options Header

   The fixed portion of the DSR Options header is used to carry
   information that must be present in any DSR Options header.  This
   fixed portion of the DSR Options header has the following format:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Next Header  |F|   Reserved  |        Payload Length         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   .                                                               .
   .                            Options                            .
   .                                                               .
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Next Header

         8-bit selector.  Identifies the type of header immediately
         following the DSR Options header.  Uses the same values as the
         IPv4 Protocol field [34]. 
NOTE: Accept input from user as to what the next header is and fill this field with 
      the IANA defined value for that protocol. Thus, UDP and TCP may be input by user
      and you need to use 17 and 6 respectively.

      Flow State Header (F)

         Flag bit.  MUST be set to 0 from client to server and to 1 from
         server to client.  

      Reserved

         MUST be sent as 0 and ignored on reception.

      Payload Length

         The length of the DSR Options header, excluding the 4-octet
         fixed portion.  The value of the Payload Length field defines
         the total length of all options carried in the DSR Options
         header.

      Options

         Variable-length field; the length of the Options field is
         specified by the Payload Length field in this DSR Options
         header.  Contains one or more pieces of optional information
         (DSR options), encoded in type-length-value (TLV) format.

Route Request Option

   The Route Request option in a DSR Options header is encoded as
   follows:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Option Type  |  Opt Data Len |         Identification        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Target Address                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                           Address[1]                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Option Type

         1 from client to server and 2 from server to client.  

      Opt Data Len

         8-bit unsigned integer.  Length of the option, in octets,
         excluding the Option Type and Opt Data Len fields.

      Identification

         A unique value generated by the initiator (original sender) of
         the Route Request.  Clients initiating a Route Request generate
         a new Identification value for each Route Request, for example
         based on a sequence number counter of all Route Requests
         initiated by the node.

      Target Address

         The address input by the user. Added by the client. It has no Address[1] field.

      Address[1]

         Address[1] is the address of the server. This is added by the server when replying
         to the client request.

Group 4:
Implement as a UDP server with select

Group 6:
Implement as an iterative TCP server with select

Group 10:
Implement as a concurrent TCP server with processes