httpfromtcp

An HTTP/1.1 server built from raw TCP sockets in Go — no net/http on the server side.

What this is

A from-scratch implementation of the HTTP/1.1 protocol on top of TCP, including:

• Request parsing — a finite state machine that incrementally parses request lines, headers, and bodies from a TCP stream
• Response writing — status lines, headers, and body output with buffered I/O
• Header management — case-insensitive storage, multi-value support, validation per RFC token rules
• Chunked transfer encoding — streaming responses with trailers (SHA256 checksum, content length)
• Reverse proxy — proxies /httpbin/* routes to httpbin.org using chunked encoding
• Video streaming — serves binary files by streaming in 32KB chunks instead of loading into memory
• Concurrency — goroutine-per-connection model capped with a semaphore (100 max) and race-free shutdown via atomic.Bool

Project structure

cmd/
  httpserver/    HTTP server on port 42069
  tcplistener/   Raw TCP listener that prints parsed requests
  udpsender/     Interactive UDP client
internal/
  server/        TCP accept loop, connection handling, concurrency control
  request/       State machine HTTP request parser
  response/      Buffered HTTP response writer
  headers/       Header parsing, storage, and validation

Running

go run cmd/httpserver/main.go

Place a video at assets/video.mp4 for the /video endpoint.

Routes

Route	Description
/	200 OK
/yourproblem	400 Bad Request
/myproblem	500 Internal Server Error
/video	Streams assets/video.mp4
/httpbin/*	Proxies to httpbin.org with chunked encoding and SHA256 trailer