cdns-rs 1.2.2

A native Sync/Async Rust implementation of client DNS resolver.
Documentation
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pub mod async_intrf;

use std::io::ErrorKind;
use std::{sync::Arc, time::Duration};


use async_trait::async_trait;

use tokio::net::{TcpStream, UdpSocket};
use tokio::io::{AsyncWriteExt, AsyncReadExt};
use tokio::time::timeout;
use tokio::net::{TcpSocket};



use crate::a_sync::network::SocketTap;
use crate::network_common::SocketTapCommon;
use crate::{internal_error, internal_error_map, CDnsErrorType};
use crate::{a_sync::{network::{NetworkTap, NetworkTapType}, SocketTaps}, cfg_resolv_parser::ResolveConfEntry, CDnsResult};


#[derive(Clone, Debug)]
pub struct TokioSocketBase;

impl SocketTaps<TokioSocketBase> for TokioSocketBase
{
    type TcpSock = TcpStream;

    type UdpSock = UdpSocket;

    #[cfg(feature = "use_async_tokio_tls")]
    type TlsSock = self::with_tls::TcpTlsConnection;
    
    #[inline]
    fn new_tcp_socket(resolver: Arc<ResolveConfEntry>, timeout: Duration) -> CDnsResult<Box<NetworkTapType<TokioSocketBase>>>
    {
        return NetworkTap::<Self::TcpSock, TokioSocketBase>::new(resolver, timeout)
    }
    
    #[inline]
    fn new_udp_socket(resolver: Arc<ResolveConfEntry>, timeout: Duration) -> CDnsResult<Box<NetworkTapType<TokioSocketBase>>>
    {
        return NetworkTap::<Self::UdpSock, TokioSocketBase>::new(resolver, timeout)
    }
    
    #[cfg(feature = "use_async_tokio_tls")]
    #[inline]
    fn new_tls_socket(resolver: Arc<ResolveConfEntry>, timeout: Duration) -> CDnsResult<Box<NetworkTapType<TokioSocketBase>>> 
    {
        return NetworkTap::<Self::TlsSock, TokioSocketBase>::new(resolver, timeout)
    }
}

#[cfg(feature = "use_async_tokio_tls")]
pub mod with_tls
{
    use std::io::ErrorKind;
    use std::os::fd::{AsFd, BorrowedFd};
    use std::sync::Arc;
    use std::time::Duration;

    use async_trait::async_trait;
    use rustls::pki_types::ServerName;
    use rustls::RootCertStore;
    use tokio::io::{AsyncReadExt, AsyncWriteExt};
    use tokio::net::TcpStream;
    use tokio::time::timeout;
    use tokio_rustls::client::TlsStream;

    use crate::a_sync::network::{NetworkTap, SocketTap};
    use crate::a_sync::tokio_exc::new_tcp_stream;
    use crate::a_sync::TokioSocketBase;
    use crate::cfg_resolv_parser::ResolveConfEntry;
    use crate::network_common::SocketTapCommon;
    use crate::{internal_error, internal_error_map, CDnsErrorType, CDnsResult};

    #[derive(Debug)]
    pub struct TcpTlsConnection
    {
        stream: TlsStream<TcpStream>,
    }

    impl AsFd for TcpTlsConnection
    {
        fn as_fd(&self) -> BorrowedFd<'_> 
        {
            return self.stream.get_ref().0.as_fd();
        }
    }

    impl TcpTlsConnection
    {   async 
        fn connect(cfg: &ResolveConfEntry, conn_timeout: Option<Duration>) -> CDnsResult<Self> 
        {
            //&self.domain_name, self.cfg.get_resolver_sa(), 
            //self.cfg.get_adapter_ip()

            let domain_name = 
                if let Some(domainname) = cfg.get_tls_domain()
                {
                    //webpki::DnsNameRef::try_from_ascii_str(domainname).map_err(|e| internal_error_map!(CDnsErrorType::InternalError, "{}", e))?
                    ServerName::try_from(domainname.clone())
                        .map_err(|e| 
                            internal_error_map!(CDnsErrorType::InternalError, "{}", e)
                        )?
                }
                else
                {
                    internal_error!(CDnsErrorType::InternalError, "no domain is set for TLS conncection");
                };

            //let f = webpki::DnsNameRef::try_from_ascii_str(domainname).map_err(|e| internal_error_map!(CDnsErrorType::InternalError, "{}", e))?;

            let config = 
                rustls
                    ::ClientConfig
                    ::builder_with_protocol_versions(&[&rustls::version::TLS12])
                        .with_root_certificates(RootCertStore{roots: webpki_roots::TLS_SERVER_ROOTS.into()})
                        .with_no_client_auth();

            let conn = 
                tokio_rustls::TlsConnector::from(Arc::new(config));

            let socket =  new_tcp_stream(&cfg, conn_timeout).await?;

            
            let mut stream_tls = 
                conn
                    .connect(domain_name, socket)
                    .await
                    .map_err(|e|
                        internal_error_map!(CDnsErrorType::IoError, "{}", e)
                    )?;

            stream_tls.flush().await.map_err(|e| internal_error_map!(CDnsErrorType::IoError, "{}", e))?;

            return Ok( Self{ stream: stream_tls } );
        }

        async 
        fn internal_poll_read(&self, timeout_dur: Duration) -> CDnsResult<()>
        {
            timeout(timeout_dur, self.stream.get_ref().0.readable())
                .await
                .map_err(|e|
                    internal_error_map!(CDnsErrorType::IoError, "Timeout {}", e)
                )?
                .map_err(|e|
                    internal_error_map!(CDnsErrorType::IoError, "socket poll error {}", e)
                )
        }

    }


    #[async_trait]
    impl SocketTap<TokioSocketBase> for NetworkTap<TcpTlsConnection, TokioSocketBase>
    {
        async
        fn connect(&mut self, conn_timeout: Option<Duration>) -> CDnsResult<()>
        {
            if self.sock.is_some() == true
            {
                // ignore
                return Ok(());
            }

            let socket= 
                TcpTlsConnection::connect(self.cfg.as_ref(), conn_timeout).await?;

            self.sock = Some(socket);

            return Ok(());
        }

        fn is_encrypted(&self) -> bool 
        {
            return true;
        }

        fn is_tcp(&self) -> bool 
        {
            return true;
        }

        fn should_append_len(&self) -> bool
        {
            return true;
        }

        async 
        fn poll_read(&self) -> CDnsResult<()>
        {
            return self.sock.as_ref().unwrap().internal_poll_read(self.timeout).await;
        }

        async 
        fn send(&mut self, sndbuf: &[u8]) -> CDnsResult<usize>  
        {
            return 
                self
                    .sock
                    .as_mut()
                    .unwrap()
                    .stream
                    .write_all(sndbuf)
                    .await
                    .map_err(|e| internal_error_map!(CDnsErrorType::IoError, "{}", e))
                    .map(|_| sndbuf.len());
        }

        async
        fn recv(&mut self, rcvbuf: &mut [u8]) -> CDnsResult<usize> 
        {
            loop
            {
                match self.sock.as_mut().unwrap().stream.read(rcvbuf).await
                {
                    Ok(n) => 
                    {
                        return Ok(n);
                    },
                    Err(ref e) if e.kind() == ErrorKind::WouldBlock =>
                    {
                        internal_error!(CDnsErrorType::RequestTimeout, "request timeout from: '{}'", self.get_remote_addr()); 
                    },
                    Err(ref e) if e.kind() == ErrorKind::Interrupted =>
                    {
                        continue;
                    },
                    Err(e) =>
                    {
                        internal_error!(CDnsErrorType::IoError, "{}", e); 
                    }
                }
            }
        }
    }
} // with_tls

#[async_trait]
impl SocketTap<TokioSocketBase> for NetworkTap<UdpSocket, TokioSocketBase>
{
    async
    fn connect(&mut self, _conn_timeout: Option<Duration>) -> CDnsResult<()>
    {
        if self.sock.is_some() == true
        {
            // ignore
            return Ok(());
        }

        let socket = 
            UdpSocket::bind(self.cfg.get_adapter_ip())
                .await
                .map_err(|e| internal_error_map!(CDnsErrorType::InternalError, "{}", e))?;

        socket.connect(self.cfg.get_resolver_sa())
            .await
            .map_err(|e| internal_error_map!(CDnsErrorType::IoError, "{}", e))?;

        self.sock = Some(socket);

        return Ok(());
    }

    fn is_encrypted(&self) -> bool 
    {
        return false;
    }

    fn is_tcp(&self) -> bool 
    {
        return false;
    }

    fn should_append_len(&self) -> bool
    {
        return false;
    }

    async 
    fn poll_read(&self) -> CDnsResult<()>
    {
        timeout(self.timeout, self.sock.as_ref().unwrap().readable())
            .await
            .map_err(|e|
                internal_error_map!(CDnsErrorType::IoError, "Timeout {}", e)
            )?
            .map_err(|e|
                internal_error_map!(CDnsErrorType::IoError, "socket poll error {}", e)
            )
    }

    async
    fn send(&mut self, sndbuf: &[u8]) -> CDnsResult<usize> 
    {
        return 
            self.sock.as_mut()
                .unwrap()
                .send(sndbuf)
                .await
                .map_err(|e| internal_error_map!(CDnsErrorType::IoError, "{}", e));
    }

    async 
    fn recv(&mut self, rcvbuf: &mut [u8]) -> CDnsResult<usize> 
    {
        async 
        fn sub_recv(this: &mut NetworkTap<UdpSocket, TokioSocketBase>, rcvbuf: &mut [u8]) -> CDnsResult<usize> 
        {
            loop
            {
                match this.sock.as_mut().unwrap().recv_from(rcvbuf).await
                {
                    Ok((rcv_len, rcv_src)) =>
                    {
                        // this should not fail because socket is "connected"
                        if &rcv_src != this.get_remote_addr()
                        {
                            internal_error!(
                                CDnsErrorType::DnsResponse, 
                                "received answer from unknown host: '{}' exp: '{}'", 
                                this.get_remote_addr(), 
                                rcv_src
                            );
                        }

                        return Ok(rcv_len);
                    },
                    Err(ref e) if e.kind() == ErrorKind::WouldBlock =>
                    {
                        continue;
                    },
                    Err(ref e) if e.kind() == ErrorKind::Interrupted =>
                    {
                        continue;
                    },
                    Err(e) =>
                    {
                        internal_error!(CDnsErrorType::IoError, "{}", e); 
                    }
                } // match
            } // loop
            
        }

        // wait for timeout
        match timeout(self.timeout, sub_recv(self, rcvbuf)).await
        {
            Ok(r) => 
                return r,
            Err(e) => 
                internal_error!(CDnsErrorType::RequestTimeout, "{}", e)
        }
    }
}

async 
fn new_tcp_stream(cfg: &ResolveConfEntry, conn_timeout: Option<Duration>) -> CDnsResult<TcpStream> 
{
    // create socket
    let socket = 
        if cfg.get_resolver_ip().is_ipv4() == true
        {
            TcpSocket::new_v4()
        }
        else
        {
            TcpSocket::new_v6()
        }
        .map_err(|e| internal_error_map!(CDnsErrorType::IoError, "{}", e))?;

    // bind address
    socket.bind(*cfg.get_adapter_ip()).map_err(|e| internal_error_map!(CDnsErrorType::IoError, "{}", e))?;

    socket.set_keepalive(false).map_err(|e| internal_error_map!(CDnsErrorType::IoError, "{}", e))?;

    socket.set_nodelay(true).map_err(|e| internal_error_map!(CDnsErrorType::IoError, "{}", e))?;

    // connect
    let tcpstream = 
        if let Some(c_timeout) = conn_timeout
        {
            timeout(c_timeout, socket.connect(*cfg.get_resolver_sa()))
                .await
                .map_err(|e| internal_error_map!(CDnsErrorType::IoError, "{}", e))?
                .map_err(|e| internal_error_map!(CDnsErrorType::IoError, "{}", e))?
        }
        else
        {
            socket
                .connect(*cfg.get_resolver_sa())
                .await
                .map_err(|e| internal_error_map!(CDnsErrorType::IoError, "{}", e))?
        };

    return Ok(tcpstream);
}

#[async_trait]
impl SocketTap<TokioSocketBase> for NetworkTap<TcpStream, TokioSocketBase>
{
    async 
    fn connect(&mut self, conn_timeout: Option<Duration>) -> CDnsResult<()> 
    {
        if self.sock.is_some() == true
        {
            // ignore
            return Ok(());
        }

        // create socket
        let tcpstream = new_tcp_stream(&self.cfg, conn_timeout).await?;

        self.sock = Some(tcpstream);

        return Ok(());
    }

    fn is_encrypted(&self) -> bool 
    {
        return false;
    }

    fn is_tcp(&self) -> bool 
    {
        return true;
    }

    fn should_append_len(&self) -> bool
    {
        return true;
    }

    async 
    fn poll_read(&self) -> CDnsResult<()>
    {
        timeout(self.timeout, self.sock.as_ref().unwrap().readable())
            .await
            .map_err(|e|
                internal_error_map!(CDnsErrorType::IoError, "Timeout {}", e)
            )?
            .map_err(|e|
                internal_error_map!(CDnsErrorType::IoError, "socket poll error {}", e)
            )
    }

    async 
    fn send(&mut self, sndbuf: &[u8]) -> CDnsResult<usize>  
    {
        return 
            self
                .sock
                .as_mut()
                .unwrap()
                .write(sndbuf)
                .await
                .map_err(|e| internal_error_map!(CDnsErrorType::IoError, "{}", e));
    }

    async 
    fn recv(&mut self, rcvbuf: &mut [u8]) -> CDnsResult<usize> 
    {
        async 
        fn sub_recv(this: &mut NetworkTap<TcpStream, TokioSocketBase>, rcvbuf: &mut [u8]) -> CDnsResult<usize> 
        {
            loop
            {
                match this.sock.as_mut().unwrap().read(rcvbuf).await
                {
                    Ok(n) => 
                    {
                        return Ok(n);
                    },
                    Err(ref e) if e.kind() == ErrorKind::WouldBlock =>
                    {
                        continue;
                    },
                    Err(ref e) if e.kind() == ErrorKind::Interrupted =>
                    {
                        continue;
                    },
                    Err(e) =>
                    {
                        internal_error!(CDnsErrorType::IoError, "{}", e); 
                    }
                } // match
            } // loop
        }

        // wait for timeout
        match timeout(self.timeout, sub_recv(self, rcvbuf)).await
        {
            Ok(r) => return r,
            Err(e) => internal_error!(CDnsErrorType::RequestTimeout, "{}", e)
        }
    }
}



#[cfg(test)]
mod tests
{
    use std::{net::{IpAddr, SocketAddr}, sync::Arc, time::Duration};

    use tokio::net::UdpSocket;

    use crate::{a_sync::{network::NetworkTap, TokioSocketBase}, cfg_resolv_parser::ResolveConfEntry, common::IPV4_BIND_ALL};

    #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
    async fn test_struct()
    {
        
        let ip0: IpAddr = "127.0.0.1".parse().unwrap();
        let bind =  SocketAddr::from((IPV4_BIND_ALL, 0));
        let v = Arc::new(ResolveConfEntry::new(SocketAddr::new(ip0, 53), None, bind).unwrap());
        let res = NetworkTap::<UdpSocket, TokioSocketBase>::new(v, Duration::from_secs(5));

        assert_eq!(res.is_ok(), true, "{}", res.err().unwrap());

        let _res = res.unwrap();
    }
}