I think you can do it. Here I explain you, in a very simple form, the phases your web server needs to do to proccess a request1- Analyze the headers of the requests, this wil tell you what resource are the client looking for. A very simple example:
GET /index.html HTTP/1.1 -> This is the request method (GET or POST are the most common, but you can implement others like PUT or DELETEi)2- Write the response headers
Host: example.com -> This is the host that the client is connecting to, I think you won't need to analyze it, unless you want multiple domains in same ip, which are very complex to implement
Content-Type: text/html -> This obviously, is the content type, you usually will get this if your client wants an html page
Here you send the response headers. Here is an example:
HTTP/1.1 200 OK -> his is the code for an ok request, also there are other codes 404 Not Found, 403 Forbidden and 500 Internal Server Error are very simple codes3- Send two CRLF to separate the headers from the content4- Send the contents
Content-Type: text/html -> This you send what type of data are you sending, text/html for html, text/xml for xml or text/plan for a txt file.
Content-Length: number -> You here put the size of the data you want to send.
I hope you find this useful.
WOW, I have used OpenWRT, but didn't know that there are adapters with OpenWRT!