EEM $482$: Fundamentals of Data Network

Homework $1$: Design of Simple Query and Response Protocol $($SQRP$)$ Version $1\mathrm{.}0$

Overview:

This assignment involves the design of Version $1\mathrm{.}0$ of the Simple Query and Response Protocol $($SQRP$),($this is hypothetical protocol, don't check on Internet$)$ focusing on file search operations within a specified directory based on file extensions. The protocol must be capable of handling queries and responses between a client and server, facilitating checks for directory existence, file existence, file modification status, and identification of modified files with a specified extension. Version $1\mathrm{.}0$ is responsible only checking files in the server.

Objective:

Design the SQRP to enable searching for files with a given three$-$letter extension $($e$.$g$.,.$txt$,.$exe$)$ in the IhomelHW$1$ directory, incorporating the file extension into the protocol's header. The protocol must support the following operations with an $8-$byte header limit:

Verify directory existence.

Check file existence.

Determine if an existing file has been modified after a specified timestamp.

Identify files with a specified extension that have been modified after a given timestamp.

Protocol Design Requirements:

Header Structure:

Design an $8-$byte header for SQRP that includes the following fields:

MessageType: Distinguishes between a query $($QUERY$)$ and a response $($RESPONSE$).$

QueryType: Identifies the operation $($directory search or file search$).$

MessageID: Provides a unique identifier for tracking the message.

Timestamp: Embeds a compact representation of the "modified after" timestamp.

StatusCode $($for responses only$)$: Indicates the outcome of the operation $($e$.$g$.,200$ for success, $404$ for not found$).$

Reserved: Allocates bytes for future enhancements or additional details.

Message Body:

Utilize the message body to embed primary search parameters and convey search results. The body should list matching files, including their names, paths, and modification dates.

Task Descriptions:

Protocol Specification:

Define and document the SQRP$\text{'}$s operational behavior, including header field definitions, encoding schemes for the timestamp, and the handling process for different QueryTypes.

Specify the format and structure for request and response messages under each operation.