renet/src/socket/tcp.rs

262 lines
8.4 KiB
Rust
Raw Normal View History

2016-12-21 03:51:52 +08:00
use Error;
2016-12-19 03:40:11 +08:00
use Managed;
2016-12-21 03:51:52 +08:00
use wire::{IpProtocol, IpAddress, IpEndpoint};
use wire::{TcpPacket, TcpRepr, TcpControl};
use socket::{Socket, PacketRepr};
2016-12-19 03:40:11 +08:00
/// A TCP stream ring buffer.
#[derive(Debug)]
pub struct StreamBuffer<'a> {
2016-12-19 03:40:11 +08:00
storage: Managed<'a, [u8]>,
read_at: usize,
length: usize
}
impl<'a> StreamBuffer<'a> {
2016-12-19 03:40:11 +08:00
/// Create a packet buffer with the given storage.
pub fn new<T>(storage: T) -> StreamBuffer<'a>
2016-12-19 03:40:11 +08:00
where T: Into<Managed<'a, [u8]>> {
StreamBuffer {
2016-12-19 03:40:11 +08:00
storage: storage.into(),
read_at: 0,
length: 0
}
}
/// Enqueue a slice of octets up to the given size into the buffer, and return a pointer
/// to the slice.
///
/// The returned slice may be shorter than requested, as short as an empty slice,
/// if there is not enough contiguous free space in the buffer.
pub fn enqueue(&mut self, mut size: usize) -> &mut [u8] {
let write_at = (self.read_at + self.length) % self.storage.len();
// We can't enqueue more than there is free space.
let free = self.storage.len() - self.length;
if size > free { size = free }
// We can't contiguously enqueue past the beginning of the storage.
let until_end = self.storage.len() - write_at;
if size > until_end { size = until_end }
self.length += size;
&mut self.storage[write_at..write_at + size]
}
/// Dequeue a slice of octets up to the given size from the buffer, and return a pointer
/// to the slice.
///
/// The returned slice may be shorter than requested, as short as an empty slice,
/// if there is not enough contiguous filled space in the buffer.
pub fn dequeue(&mut self, mut size: usize) -> &[u8] {
let read_at = self.read_at;
// We can't dequeue more than was queued.
if size > self.length { size = self.length }
// We can't contiguously dequeue past the end of the storage.
let until_end = self.storage.len() - self.read_at;
if size > until_end { size = until_end }
self.read_at = (self.read_at + size) % self.storage.len();
self.length -= size;
&self.storage[read_at..read_at + size]
}
}
impl<'a> Into<StreamBuffer<'a>> for Managed<'a, [u8]> {
fn into(self) -> StreamBuffer<'a> {
StreamBuffer::new(self)
}
}
/// A Transmission Control Protocol data stream.
#[derive(Debug)]
pub struct Stream<'a> {
local_end: IpEndpoint,
remote_end: IpEndpoint,
local_seq: i32,
remote_seq: i32,
rx_buffer: StreamBuffer<'a>,
tx_buffer: StreamBuffer<'a>
}
impl<'a> Stream<'a> {
/// Return the local endpoint.
#[inline(always)]
pub fn local_end(&self) -> IpEndpoint {
self.local_end
}
/// Return the remote endpoint.
#[inline(always)]
pub fn remote_end(&self) -> IpEndpoint {
self.remote_end
}
/// See [Socket::collect](enum.Socket.html#method.collect).
pub fn collect(&mut self, src_addr: &IpAddress, dst_addr: &IpAddress,
protocol: IpProtocol, payload: &[u8])
-> Result<(), Error> {
if protocol != IpProtocol::Tcp { return Err(Error::Rejected) }
let packet = try!(TcpPacket::new(payload));
let repr = try!(TcpRepr::parse(&packet, src_addr, dst_addr));
if self.local_end != IpEndpoint::new(*dst_addr, repr.dst_port) {
return Err(Error::Rejected)
}
if self.remote_end != IpEndpoint::new(*src_addr, repr.src_port) {
return Err(Error::Rejected)
}
// FIXME: process
Ok(())
}
/// See [Socket::dispatch](enum.Socket.html#method.dispatch).
pub fn dispatch(&mut self, _f: &mut FnMut(&IpAddress, &IpAddress,
IpProtocol, &PacketRepr) -> Result<(), Error>)
-> Result<(), Error> {
// FIXME: process
// f(&self.local_end.addr,
// &self.remote_end.addr,
// IpProtocol::Tcp,
// &TcpRepr {
// src_port: self.local_end.port,
// dst_port: self.remote_end.port,
// payload: &packet_buf.as_ref()[..]
// })
Ok(())
}
}
impl<'a> PacketRepr for TcpRepr<'a> {
fn buffer_len(&self) -> usize {
self.buffer_len()
}
fn emit(&self, src_addr: &IpAddress, dst_addr: &IpAddress, payload: &mut [u8]) {
let mut packet = TcpPacket::new(payload).expect("undersized payload");
self.emit(&mut packet, src_addr, dst_addr)
}
}
2016-12-21 03:51:52 +08:00
/// A description of incoming TCP connection.
#[derive(Debug)]
pub struct Incoming {
local_end: IpEndpoint,
remote_end: IpEndpoint,
local_seq: i32,
remote_seq: i32
2016-12-21 03:51:52 +08:00
}
impl Incoming {
/// Return the local endpoint.
#[inline(always)]
2016-12-21 03:51:52 +08:00
pub fn local_end(&self) -> IpEndpoint {
self.local_end
}
/// Return the remote endpoint.
#[inline(always)]
2016-12-21 03:51:52 +08:00
pub fn remote_end(&self) -> IpEndpoint {
self.remote_end
}
/// Convert into a data stream using the given buffers.
pub fn into_stream<'a, T>(self, rx_buffer: T, tx_buffer: T) -> Socket<'a, 'static>
where T: Into<StreamBuffer<'a>> {
Socket::TcpStream(Stream {
rx_buffer: rx_buffer.into(),
tx_buffer: tx_buffer.into(),
local_end: self.local_end,
remote_end: self.remote_end,
local_seq: self.local_seq,
remote_seq: self.remote_seq
})
}
2016-12-21 03:51:52 +08:00
}
/// A Transmission Control Protocol server socket.
#[derive(Debug)]
pub struct Listener<'a> {
endpoint: IpEndpoint,
backlog: Managed<'a, [Option<Incoming>]>,
accept_at: usize,
length: usize
}
impl<'a> Listener<'a> {
/// Create a server socket with the given backlog.
pub fn new<T>(endpoint: IpEndpoint, backlog: T) -> Socket<'a, 'static>
where T: Into<Managed<'a, [Option<Incoming>]>> {
Socket::TcpListener(Listener {
2016-12-21 03:51:52 +08:00
endpoint: endpoint,
backlog: backlog.into(),
accept_at: 0,
length: 0
})
}
/// Accept a connection from this server socket,
pub fn accept(&mut self) -> Option<Incoming> {
if self.length == 0 { return None }
let accept_at = self.accept_at;
self.accept_at = (self.accept_at + 1) % self.backlog.len();
self.length -= 1;
self.backlog[accept_at].take()
}
/// See [Socket::collect](enum.Socket.html#method.collect).
pub fn collect(&mut self, src_addr: &IpAddress, dst_addr: &IpAddress,
protocol: IpProtocol, payload: &[u8])
-> Result<(), Error> {
if protocol != IpProtocol::Tcp { return Err(Error::Rejected) }
let packet = try!(TcpPacket::new(payload));
let repr = try!(TcpRepr::parse(&packet, src_addr, dst_addr));
if repr.dst_port != self.endpoint.port { return Err(Error::Rejected) }
if !self.endpoint.addr.is_unspecified() {
if self.endpoint.addr != *dst_addr { return Err(Error::Rejected) }
}
match (repr.control, repr.ack_number) {
(TcpControl::Syn, None) => {
if self.length == self.backlog.len() { return Err(Error::Exhausted) }
let inject_at = (self.accept_at + self.length) % self.backlog.len();
self.length += 1;
assert!(self.backlog[inject_at].is_none());
self.backlog[inject_at] = Some(Incoming {
local_end: IpEndpoint::new(*dst_addr, repr.dst_port),
remote_end: IpEndpoint::new(*src_addr, repr.src_port),
// FIXME: choose something more secure?
local_seq: !repr.seq_number,
remote_seq: repr.seq_number
2016-12-21 03:51:52 +08:00
});
Ok(())
}
_ => Err(Error::Rejected)
}
}
}
2016-12-19 03:40:11 +08:00
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_buffer() {
let mut buffer = StreamBuffer::new(vec![0; 8]); // ........
2016-12-19 03:40:11 +08:00
buffer.enqueue(6).copy_from_slice(b"foobar"); // foobar..
assert_eq!(buffer.dequeue(3), b"foo"); // ...bar..
buffer.enqueue(6).copy_from_slice(b"ba"); // ...barba
buffer.enqueue(4).copy_from_slice(b"zho"); // zhobarba
assert_eq!(buffer.dequeue(6), b"barba"); // zho.....
assert_eq!(buffer.dequeue(8), b"zho"); // ........
buffer.enqueue(8).copy_from_slice(b"gefug"); // ...gefug
}
}