• Part 1 [60 points total]: Construct a packet filtering tool. You will test your tool by filtering a set of IP datagrams captured during a set of test runs. The captured packets are stored as a sequence of records in a file with the format given below.

  
   0                             15                              31
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                          IP Header                           ...
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                            Data                              ...
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  ...                                                             |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                      IP Header (Packet 2)                    ...
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  ...
  

  The testing of your tool takes the form used by tcpdump. An example is the following.

  IP.port -> IP.port Proto TCPFlags Datalen

  Proto is either "TCP" or "UDP" depending on the protocol field. TCPFlags is a set of characters specifying the TCP flags that are set. These are U, A, P, R, S, or F. And Datalen is the length of the entire IP packet. An example would be:

  192.168.0.39.22 -> 192.168.0.28.7462 TCP S 40

  192.168.0.28.7462 -> 192.168.0.39.22 TCP S,A 40

  . . .

  The first packet would be an TCP packet with IP source address of 192.168.0.39 and source port of 22 going to IP destination address 192.168.0.28 and destination port 7462. The TCP flag that is set is SYN. Packet length is 40 bytes.
  • A [15 points]: Display only IP packets meeting specific IP address criteria. The Source IP address and/or the Destination IP address must match criteria given by the user. This criteria may include a netmask to apply to the IP address as well. This criteria may be given as command line arguments to the filter. With the -s argument specifying the Source IP address to look for and the -d argument specifying the Destination IP address to look for. e.g. $ pfilter -s 192.168.0.0/24 filename might only display information for IP packets that have a source IP address that falls in the 192.168.0.0/24 subnet. Both the Source IP address and Destination IP address may be given or just one of them may be given.
  • B [15 points]: Display only IP packets meeting specific TCP/UDP port criteria. The Source port and/or the Destination port must match criteria given by the user. This criteria may be given as command line arguments to the filter. With the -S argument specifying the Source port number to look for and the -D argument specifying the Destination port number to look for. Both the Source port and Destination port may be given or just one of them may be given.
  • C [15 points]: Display only IP packets meeting specific protocol criteria. The IP Protocol must match criteria given by the user. This criteria may be given as a command line argument to the filter. The choices are "UDP" or "TCP". The argument that may be used is -p.
  • D [15 points]: At the end of the file, display each individual unique UDP and TCP connection/session. Each session should include the IP addresses, TCP/UDP port numbers, number of bytes sent in each direction, and number of packets sent in each direction.
  • Example Input for Testing: Here is an example input file to begin testing with. Additional files will be used for submissions. The contents of the example input file can be found here.
• Part 2: Protocol Design [40 points total]: Design and document a protocol to handle the management of a calendar for users. Your protocol must provide the following features:
  • Account Management: login, logout, create, delete, authentication change, etc.
  • Event Scheduling: create event, delete event, edit event, etc.
  • Error Handling: sending messages to unknown accounts, not logged in accounts, events that collide for accounts, etc.
  An events must have a set of attributes. These must include, at least, date, time, and attendance list (list of accounts that are asked to attend). You may add additional functionality as you desire. You may use any existing protocols that you like. If you use HTTP or other application protocols, you will need to explain what you are adding to them in detail. You must provide reasoning why you chose specific options, architecture, etc. Your document should be in text or PDF. Word documents will NOT be accepted.

Notes: Your submissions must at least compile before any credit will be given. Submissions that do not compile will not be graded. Submissions submitted after the due date will not be graded. All work must be your own original work. To get partial credit for parts of the assignment, you must demonstrate that those pieces work by themselves. If you share code with others, you will be given a 0 for the assignment. This assignment set is worth 25% of your total grade.