//! Server handshake machine. use std::fmt::Write as FmtWrite; use std::io::{Read, Write}; use std::marker::PhantomData; use std::mem::replace; use httparse; use httparse::Status; use error::{Error, Result}; use protocol::{WebSocket, Role}; use super::headers::{Headers, FromHttparse, MAX_HEADERS}; use super::machine::{HandshakeMachine, StageResult, TryParse}; use super::{MidHandshake, HandshakeRole, ProcessingResult, convert_key}; /// Request from the client. pub struct Request { /// Path part of the URL. pub path: String, /// HTTP headers. pub headers: Headers, } impl Request { /// Reply to the response. pub fn reply(&self, extra_headers: Option>) -> Result> { let key = self.headers.find_first("Sec-WebSocket-Key") .ok_or_else(|| Error::Protocol("Missing Sec-WebSocket-Key".into()))?; let mut reply = format!( "\ HTTP/1.1 101 Switching Protocols\r\n\ Connection: Upgrade\r\n\ Upgrade: websocket\r\n\ Sec-WebSocket-Accept: {}\r\n", convert_key(key)? ); if let Some(eh) = extra_headers { for (k, v) in eh { write!(reply, "{}: {}\r\n", k, v).unwrap(); } } write!(reply, "\r\n").unwrap(); Ok(reply.into()) } } impl TryParse for Request { fn try_parse(buf: &[u8]) -> Result> { let mut hbuffer = [httparse::EMPTY_HEADER; MAX_HEADERS]; let mut req = httparse::Request::new(&mut hbuffer); Ok(match req.parse(buf)? { Status::Partial => None, Status::Complete(size) => Some((size, Request::from_httparse(req)?)), }) } } impl<'h, 'b: 'h> FromHttparse> for Request { fn from_httparse(raw: httparse::Request<'h, 'b>) -> Result { if raw.method.expect("Bug: no method in header") != "GET" { return Err(Error::Protocol("Method is not GET".into())); } if raw.version.expect("Bug: no HTTP version") < /*1.*/1 { return Err(Error::Protocol("HTTP version should be 1.1 or higher".into())); } Ok(Request { path: raw.path.expect("Bug: no path in header").into(), headers: Headers::from_httparse(raw.headers)? }) } } /// The callback type, the callback is called when the server receives an incoming WebSocket /// handshake request from the client, specifying a callback allows you to analyze incoming headers /// and add additional headers to the response that server sends to the client and/or reject the /// connection based on the incoming headers. Due to usability problems which are caused by a /// static dispatch when using callbacks in such places, the callback is boxed. /// /// The type uses `FnMut` instead of `FnOnce` as it is impossible to box `FnOnce` in the current /// Rust version, `FnBox` is still unstable, this code has to be updated for `FnBox` when it gets /// stable. pub type Callback = Box Result>>>; /// Server handshake role. #[allow(missing_copy_implementations)] pub struct ServerHandshake { /// Callback which is called whenever the server read the request from the client and is ready /// to reply to it. The callback returns an optional headers which will be added to the reply /// which the server sends to the user. callback: Option, /// Internal stream type. _marker: PhantomData, } impl ServerHandshake { /// Start server handshake. `callback` specifies a custom callback which the user can pass to /// the handshake, this callback will be called when the a websocket client connnects to the /// server, you can specify the callback if you want to add additional header to the client /// upon join based on the incoming headers. pub fn start(stream: S, callback: Option) -> MidHandshake { trace!("Server handshake initiated."); MidHandshake { machine: HandshakeMachine::start_read(stream), role: ServerHandshake { callback, _marker: PhantomData }, } } } impl HandshakeRole for ServerHandshake { type IncomingData = Request; type InternalStream = S; type FinalResult = WebSocket; fn stage_finished(&mut self, finish: StageResult) -> Result> { Ok(match finish { StageResult::DoneReading { stream, result, tail } => { if !tail.is_empty() { return Err(Error::Protocol("Junk after client request".into())) } let extra_headers = { if let Some(mut callback) = replace(&mut self.callback, None) { callback(&result)? } else { None } }; let response = result.reply(extra_headers)?; ProcessingResult::Continue(HandshakeMachine::start_write(stream, response)) } StageResult::DoneWriting(stream) => { debug!("Server handshake done."); ProcessingResult::Done(WebSocket::from_raw_socket(stream, Role::Server)) } }) } } #[cfg(test)] mod tests { use super::Request; use super::super::machine::TryParse; use super::super::client::Response; #[test] fn request_parsing() { const DATA: &'static [u8] = b"GET /script.ws HTTP/1.1\r\nHost: foo.com\r\n\r\n"; let (_, req) = Request::try_parse(DATA).unwrap().unwrap(); assert_eq!(req.path, "/script.ws"); assert_eq!(req.headers.find_first("Host"), Some(&b"foo.com"[..])); } #[test] fn request_replying() { const DATA: &'static [u8] = b"\ GET /script.ws HTTP/1.1\r\n\ Host: foo.com\r\n\ Connection: upgrade\r\n\ Upgrade: websocket\r\n\ Sec-WebSocket-Version: 13\r\n\ Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==\r\n\ \r\n"; let (_, req) = Request::try_parse(DATA).unwrap().unwrap(); let _ = req.reply(None).unwrap(); let extra_headers = Some(vec![(String::from("MyCustomHeader"), String::from("MyCustomValue")), (String::from("MyVersion"), String::from("LOL"))]); let reply = req.reply(extra_headers).unwrap(); let (_, req) = Response::try_parse(&reply).unwrap().unwrap(); assert_eq!(req.headers.find_first("MyCustomHeader"), Some(b"MyCustomValue".as_ref())); assert_eq!(req.headers.find_first("MyVersion"), Some(b"LOL".as_ref())); } }