nets-tcp-framed-echo

tcp echo with framing

Directory simple-demo includes a simple tcp echo server & client

Directory lib includes the params package required for many of the programs

Directory stammer-proxy includes stammerProxy, which is useful for demonstrating and testing framing

• stammerProxy.py forwards tcp streams. It may delay the transmission of data but ensures all data will be forwarded, eventually. By default, it listens on port 50000 and forwards to localhost:50001. Use the -? option for help.

Directory framed-echo includes code that implements framing described below

• framedClient.py and framedServer.py are a demonstration TCP client and server which exchange frames consisting of byte arrays in the form payload_length:payload where payload_length is in decimal.

• FramedForkServer uses fork() to handle multiple simultaneous clients.

• The -? (usage) option prints parameters and default values.

• framedSock.py holds the common code used in the client and server including framed send and receive.

Your assignment is to write fileClient.py and fileServer.py which can transfer a file ("put") from a client to the server. Your programs should:

• be in the file-transfer-lab subdir
• work with and without the proxy
• support multiple clients simultaneously using fork()
• gracefully deal with scenarios such as:
  • zero length files
  • user attempts to transmit a file which does not exist
  • file already exists on the server
  • the client or server unexpectedly disconnect
• optional (unless you're taking this course for grad credit): be able to request ("get") files from server