From 0c46f27f89ab5a11032a453379a40581e0e5d907 Mon Sep 17 00:00:00 2001
From: Skylar Hill <stellarskylark@posteo.net>
Date: Sun, 23 Jun 2024 03:02:27 -0500
Subject: [PATCH] Add basic URI parsing

It works with Lagrange, but gemget still causes the server to throw
"Operation would block"
---
 src/main.rs     |  3 ++-
 src/protocol.rs | 27 ++++++++++++++++++---------
 src/server.rs   | 35 ++++++++++++++++++++++++++---------
 3 files changed, 46 insertions(+), 19 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 517710d..4ee165b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -18,8 +18,9 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let config = rustls::ServerConfig::builder()
         .with_no_client_auth()
         .with_single_cert(certs, private_key)?;
+    let listener = TcpListener::bind(format!("[::]:{}", 1965)).unwrap();
     let srv = server::Server {
-        listener: TcpListener::bind(format!("[::]:{}", 1965)).unwrap(),
+        listener,
         tls_config: config,
     };
     match srv.listen() {
diff --git a/src/protocol.rs b/src/protocol.rs
index 9339b1d..a19a987 100644
--- a/src/protocol.rs
+++ b/src/protocol.rs
@@ -81,21 +81,39 @@ pub struct Request {
 
 #[derive(Debug)]
 pub enum RequestParseError {
+    NotTerminated,
+    Error(Box<dyn std::error::Error>),
     UserInfoGiven,
     TooLarge,
     FragmentGiven,
     BadScheme,
+    BadUrl(url::ParseError),
+}
+
+impl From<url::ParseError> for RequestParseError {
+    fn from(value: url::ParseError) -> Self {
+        RequestParseError::BadUrl(value)
+    }
+}
+
+impl From<std::io::Error> for RequestParseError {
+    fn from(value: std::io::Error) -> Self {
+        RequestParseError::Error(Box::new(value))
+    }
 }
 
 impl std::fmt::Display for RequestParseError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
+            RequestParseError::NotTerminated => write!(f, "Request not terminated with CRLF"),
+            RequestParseError::Error(e) => write!(f, "Request read error: {}", e),
             RequestParseError::UserInfoGiven => write!(f, "URI userinfo not permitted"),
             RequestParseError::TooLarge => write!(f, "URI larger than permitted 1024 bytes"),
             RequestParseError::FragmentGiven => write!(f, "URI fragments not permitted"),
             RequestParseError::BadScheme => {
                 write!(f, "URI schemes besides 'gemini' not supported")
             }
+            RequestParseError::BadUrl(e) => e.fmt(f),
         }
     }
 }
@@ -200,12 +218,3 @@ impl From<RequestParseError> for ErrorResponse {
         }
     }
 }
-
-impl From<url::ParseError> for ErrorResponse {
-    fn from(value: url::ParseError) -> Self {
-        ErrorResponse {
-            code: ErrorStatus::BadRequest,
-            error: value.to_string(),
-        }
-    }
-}
diff --git a/src/server.rs b/src/server.rs
index 37ef6c7..5b790d1 100644
--- a/src/server.rs
+++ b/src/server.rs
@@ -1,6 +1,6 @@
-use crate::protocol::{self, Response};
+use crate::protocol::*;
 use mime::Mime;
-use std::io::{Read, Write};
+use std::io::{self, BufRead, Read, Write};
 use std::{net, str::FromStr, sync::Arc};
 use url::Url;
 
@@ -12,24 +12,41 @@ pub struct Server {
 
 impl Server {
     pub fn listen(&self) -> Result<(), Box<dyn std::error::Error>> {
-        let (mut stream, _) = self.listener.accept().expect("15");
-        let mut conn =
-            rustls::ServerConnection::new(Arc::new(self.tls_config.clone())).expect("17");
+        let (mut stream, _) = self.listener.accept()?;
+        let mut conn = rustls::ServerConnection::new(Arc::new(self.tls_config.clone()))?;
 
-        let response = protocol::Request::try_from(Url::from_str("gemini://localhost")?)?.process();
+        conn.complete_io(&mut stream)?;
+        let response = read_request(conn.reader())?.process();
 
         conn.writer()
             .write_all(response.serialize().as_slice())
             .expect("23");
-        conn.complete_io(&mut stream).expect("24");
+        conn.complete_io(&mut stream)?;
 
         Ok(())
     }
 }
 
-impl protocol::Request {
+fn read_request(stream: rustls::Reader) -> Result<Request, RequestParseError> {
+    let mut reader = io::BufReader::new(stream);
+    let mut buf = String::new();
+    // The URI can be 1024 bytes long, plus \r\n
+    if reader.read_line(&mut buf)? > 1026 {
+        return Err(RequestParseError::TooLarge);
+    }
+    match buf.char_indices().rev().nth(1) {
+        Some((i, _)) if &buf[i..] != "\r\n" => Err(RequestParseError::NotTerminated),
+        None => Err(RequestParseError::NotTerminated),
+        Some(_) => Ok(()),
+    }?;
+
+    let url = Url::from_str(buf.trim())?;
+    Request::try_from(url)
+}
+
+impl Request {
     fn process(&self) -> impl Response {
-        protocol::SuccessResponse {
+        SuccessResponse {
             mime: Mime::from_str("text/gemini").expect("Hardcoded mime value failed??"),
             body: b"Hiiiiii im gay :>".to_vec(),
         }