hypha: work in progress implementation of outbound internet access

network/src/lib.rs

@@ -1,30 +1,21 @@
-use std::os::fd::AsRawFd;
-use std::panic::UnwindSafe;
-use std::str::FromStr;
 use std::sync::{Arc, Mutex};
 use std::time::Duration;
-use std::{panic, thread};
 
-use advmac::MacAddr6;
 use anyhow::{anyhow, Result};
 use futures::TryStreamExt;
-use log::{error, info, warn};
+use ipstack::stream::IpStackStream;
+use log::{debug, error, info, warn};
 use netlink_packet_route::link::LinkAttribute;
-use smoltcp::iface::{Config, Interface, SocketSet};
-use smoltcp::phy::{self, RawSocket};
-use smoltcp::time::Instant;
-use smoltcp::wire::{EthernetAddress, HardwareAddress, IpCidr};
+use raw_socket::{AsyncRawSocket, RawSocket};
+use tokio::net::TcpStream;
 use tokio::time::sleep;
+use udp_stream::UdpStream;
+
+mod raw_socket;
 
 pub struct NetworkBackend {
     pub interface: String,
-    pub device: RawSocket,
-    pub addresses: Vec<IpCidr>,
 }
-
-unsafe impl Send for NetworkBackend {}
-impl UnwindSafe for NetworkBackend {}
-
 pub struct NetworkService {
     pub network: String,
 }
@@ -36,18 +27,9 @@ impl NetworkService {
 }
 
 impl NetworkBackend {
-    pub fn new(iface: &str, cidrs: &[&str]) -> Result<NetworkBackend> {
-        let device = RawSocket::new(iface, smoltcp::phy::Medium::Ethernet)?;
-        let mut addresses: Vec<IpCidr> = Vec::new();
-        for cidr in cidrs {
-            let address =
-                IpCidr::from_str(cidr).map_err(|_| anyhow!("failed to parse cidr: {}", *cidr))?;
-            addresses.push(address);
-        }
+    pub fn new(iface: &str) -> Result<NetworkBackend> {
         Ok(NetworkBackend {
             interface: iface.to_string(),
-            device,
-            addresses,
         })
     }
 
@@ -73,34 +55,56 @@ impl NetworkBackend {
         Ok(())
     }
 
-    pub fn run(mut self) -> Result<()> {
-        let result = panic::catch_unwind(move || self.run_maybe_panic());
+    pub async fn run(&mut self) -> Result<()> {
+        let mut config = ipstack::IpStackConfig::default();
+        config.mtu(1500);
+        config.tcp_timeout(std::time::Duration::from_secs(600)); // 10 minutes
+        config.udp_timeout(std::time::Duration::from_secs(10)); // 10 seconds
 
-        if result.is_err() {
-            return Err(anyhow!("network backend has terminated"));
+        let mut socket = RawSocket::new(&self.interface)?;
+        socket.bind_interface()?;
+        let socket = AsyncRawSocket::new(socket)?;
+        let mut stack = ipstack::IpStack::new(config, socket);
+
+        while let Ok(stream) = stack.accept().await {
+            self.process_stream(stream).await?
         }
-
-        result.unwrap()
+        Ok(())
     }
 
-    fn run_maybe_panic(&mut self) -> Result<()> {
-        let mac = MacAddr6::random();
-        let mac = HardwareAddress::Ethernet(EthernetAddress(mac.to_array()));
-        let config = Config::new(mac);
-        let mut iface = Interface::new(config, &mut self.device, Instant::now());
-        iface.update_ip_addrs(|addrs| {
-            addrs
-                .extend_from_slice(&self.addresses)
-                .expect("failed to set ip addresses");
-        });
+    async fn process_stream(&mut self, stream: IpStackStream) -> Result<()> {
+        match stream {
+            IpStackStream::Tcp(mut tcp) => {
+                debug!("tcp: {}", tcp.peer_addr());
+                tokio::spawn(async move {
+                    if let Ok(mut stream) = TcpStream::connect(tcp.peer_addr()).await {
+                        let _ = tokio::io::copy_bidirectional(&mut stream, &mut tcp).await;
+                    } else {
+                        warn!("failed to connect to tcp address: {}", tcp.peer_addr());
+                    }
+                });
+            }
 
-        let mut sockets = SocketSet::new(vec![]);
-        let fd = self.device.as_raw_fd();
-        loop {
-            let timestamp = Instant::now();
-            iface.poll(timestamp, &mut self.device, &mut sockets);
-            phy::wait(fd, iface.poll_delay(timestamp, &sockets))?;
+            IpStackStream::Udp(mut udp) => {
+                debug!("udp: {}", udp.peer_addr());
+                tokio::spawn(async move {
+                    if let Ok(mut stream) = UdpStream::connect(udp.peer_addr()).await {
+                        let _ = tokio::io::copy_bidirectional(&mut stream, &mut udp).await;
+                    } else {
+                        warn!("failed to connect to udp address: {}", udp.peer_addr());
+                    }
+                });
+            }
+
+            IpStackStream::UnknownTransport(u) => {
+                debug!("unknown transport: {}", u.dst_addr());
+            }
+
+            IpStackStream::UnknownNetwork(packet) => {
+                debug!("unknown network: {:?}", packet);
+            }
         }
+        Ok(())
     }
 }
 
@@ -156,15 +160,15 @@ impl NetworkService {
         spawned: Arc<Mutex<Vec<String>>>,
     ) -> Result<()> {
         let interface = interface.to_string();
-        let mut network = NetworkBackend::new(&interface, &[&self.network])?;
+        let mut network = NetworkBackend::new(&interface)?;
         info!("initializing network backend for interface {}", interface);
         network.init().await?;
         tokio::time::sleep(Duration::from_secs(1)).await;
         info!("spawning network backend for interface {}", interface);
-        thread::spawn(move || {
-            if let Err(error) = network.run() {
+        tokio::spawn(async move {
+            if let Err(error) = network.run().await {
                 error!(
-                    "failed to run network backend for interface {}: {}",
+                    "network backend for interface {} has been stopped: {}",
                     interface, error
                 );
             }

network/src/raw_socket.rs

@@ -0,0 +1,202 @@
+use futures::ready;
+use std::os::unix::io::{AsRawFd, RawFd};
+use std::pin::Pin;
+use std::task::{Context, Poll};
+use std::{io, mem};
+
+use anyhow::Result;
+use tokio::io::unix::AsyncFd;
+use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
+
+const SIOCGIFINDEX: libc::c_ulong = 0x8933;
+
+#[derive(Debug)]
+pub struct RawSocket {
+    protocol: libc::c_short,
+    lower: libc::c_int,
+    ifreq: Ifreq,
+}
+
+impl AsRawFd for RawSocket {
+    fn as_raw_fd(&self) -> RawFd {
+        self.lower
+    }
+}
+
+impl RawSocket {
+    pub fn new(name: &str) -> io::Result<RawSocket> {
+        let protocol: libc::c_short = 0x0003;
+        let lower = unsafe {
+            let lower = libc::socket(
+                libc::AF_PACKET,
+                libc::SOCK_RAW | libc::SOCK_NONBLOCK,
+                protocol.to_be() as i32,
+            );
+            if lower == -1 {
+                return Err(io::Error::last_os_error());
+            }
+            lower
+        };
+
+        Ok(RawSocket {
+            protocol,
+            lower,
+            ifreq: ifreq_for(name),
+        })
+    }
+
+    pub fn bind_interface(&mut self) -> io::Result<()> {
+        let sockaddr = libc::sockaddr_ll {
+            sll_family: libc::AF_PACKET as u16,
+            sll_protocol: self.protocol.to_be() as u16,
+            sll_ifindex: ifreq_ioctl(self.lower, &mut self.ifreq, SIOCGIFINDEX)?,
+            sll_hatype: 1,
+            sll_pkttype: 0,
+            sll_halen: 6,
+            sll_addr: [0; 8],
+        };
+
+        unsafe {
+            let res = libc::bind(
+                self.lower,
+                &sockaddr as *const libc::sockaddr_ll as *const libc::sockaddr,
+                mem::size_of::<libc::sockaddr_ll>() as libc::socklen_t,
+            );
+            if res == -1 {
+                return Err(io::Error::last_os_error());
+            }
+        }
+
+        Ok(())
+    }
+
+    pub fn recv(&self, buffer: &mut [u8]) -> io::Result<usize> {
+        unsafe {
+            let len = libc::recv(
+                self.lower,
+                buffer.as_mut_ptr() as *mut libc::c_void,
+                buffer.len(),
+                0,
+            );
+            if len == -1 {
+                return Err(io::Error::last_os_error());
+            }
+            Ok(len as usize)
+        }
+    }
+
+    pub fn send(&self, buffer: &[u8]) -> io::Result<usize> {
+        unsafe {
+            let len = libc::send(
+                self.lower,
+                buffer.as_ptr() as *const libc::c_void,
+                buffer.len(),
+                0,
+            );
+            if len == -1 {
+                return Err(io::Error::last_os_error());
+            }
+            Ok(len as usize)
+        }
+    }
+}
+
+impl Drop for RawSocket {
+    fn drop(&mut self) {
+        unsafe {
+            libc::close(self.lower);
+        }
+    }
+}
+
+#[repr(C)]
+#[derive(Debug)]
+struct Ifreq {
+    ifr_name: [libc::c_char; libc::IF_NAMESIZE],
+    ifr_data: libc::c_int, /* ifr_ifindex or ifr_mtu */
+}
+
+fn ifreq_for(name: &str) -> Ifreq {
+    let mut ifreq = Ifreq {
+        ifr_name: [0; libc::IF_NAMESIZE],
+        ifr_data: 0,
+    };
+    for (i, byte) in name.as_bytes().iter().enumerate() {
+        ifreq.ifr_name[i] = *byte as libc::c_char
+    }
+    ifreq
+}
+
+fn ifreq_ioctl(
+    lower: libc::c_int,
+    ifreq: &mut Ifreq,
+    cmd: libc::c_ulong,
+) -> io::Result<libc::c_int> {
+    unsafe {
+        let res = libc::ioctl(lower, cmd as _, ifreq as *mut Ifreq);
+        if res == -1 {
+            return Err(io::Error::last_os_error());
+        }
+    }
+
+    Ok(ifreq.ifr_data)
+}
+
+pub struct AsyncRawSocket {
+    inner: AsyncFd<RawSocket>,
+}
+
+impl AsyncRawSocket {
+    pub fn new(socket: RawSocket) -> Result<Self> {
+        Ok(Self {
+            inner: AsyncFd::new(socket)?,
+        })
+    }
+}
+
+impl AsyncRead for AsyncRawSocket {
+    fn poll_read(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &mut ReadBuf<'_>,
+    ) -> Poll<io::Result<()>> {
+        loop {
+            let mut guard = ready!(self.inner.poll_read_ready(cx))?;
+
+            let unfilled = buf.initialize_unfilled();
+            match guard.try_io(|inner| inner.get_ref().recv(unfilled)) {
+                Ok(Ok(len)) => {
+                    buf.advance(len);
+                    return Poll::Ready(Ok(()));
+                }
+                Ok(Err(err)) => return Poll::Ready(Err(err)),
+                Err(_would_block) => continue,
+            }
+        }
+    }
+}
+
+impl AsyncWrite for AsyncRawSocket {
+    fn poll_write(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &[u8],
+    ) -> Poll<io::Result<usize>> {
+        loop {
+            let mut guard = ready!(self.inner.poll_write_ready(cx))?;
+
+            match guard.try_io(|inner| inner.get_ref().send(buf)) {
+                Ok(result) => return Poll::Ready(result),
+                Err(_would_block) => continue,
+            }
+        }
+    }
+
+    fn poll_flush(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<()>> {
+        Poll::Ready(Ok(()))
+    }
+
+    fn poll_shutdown(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<()>> {
+        Poll::Ready(Ok(()))
+    }
+}