Crate tcp_handler

Tcp-Handler

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Description

More conveniently use tokio::net::TcpStream to transfer bytes::Bytes data chunks.

You may use extra crate to read and write data, such as serde, postcard and variable-len-reader.

See tcp-server and tcp-client for conveniently building your tcp application.

Features

• Based on tokio and bytes.
• Support ReadHalf and WriteHalf of tokio::net::TcpStream. (In fact anything impl AsyncRead/AsyncWrite and Unpin can be used.)
• Support bytes::Buf. So you can send discontinuous data chunks by calling chain.
• Support encryption (rsa and aes).
• Support compression (flate2).
• Complete API document and data model.

Usage

Add this to your Cargo.toml:

[dependencies]
tcp-handler = "~0.6"

Note

If client_init using encryption mode is extremely slow in debug mode, please add this to your Cargo.toml in client side:

[profile.dev.package.num-bigint-dig]
opt-level = 3 # Speed up rsa key gen.

This is an issue in rsa crate.

Example

Directly transfer data. Without encryption and compression:

use anyhow::Result;
use bytes::{Buf, BufMut, BytesMut};
use tcp_handler::raw::{client_init, client_start, recv, send, server_init, server_start};
use tokio::net::{TcpListener, TcpStream};
use variable_len_reader::{VariableReader, VariableWriter};

#[tokio::main]
async fn main() -> Result<()> {
    // Create tcp stream.
    let server = TcpListener::bind("localhost:0").await?;
    let mut client = TcpStream::connect(server.local_addr()?).await?;
    let (mut server, _) = server.accept().await?;
    
    // Prepare the protocol of tcp-handler.
    let client_init = client_init(&mut client, "test", "0.0.0").await;
    let server_init = server_init(&mut server, "test", |v| v == "0.0.0").await;
    server_start(&mut server, "test", "0.0.0", server_init).await?;
    client_start(&mut client, client_init).await?;
    
    // Send.
    let mut writer = BytesMut::new().writer();
    writer.write_string("hello server.")?;
    send(&mut client, &mut writer.into_inner()).await?;
    
    // Receive.
    let mut reader = recv(&mut server).await?.reader();
    let message = reader.read_string()?;
    assert_eq!("hello server.", message);
    
    Ok(())
}

Transfer message with encrypted protocol:

use anyhow::Result;
use bytes::{Buf, BufMut, BytesMut};
use tcp_handler::encrypt::{client_init, client_start, recv, send, server_init, server_start};
use tokio::net::{TcpListener, TcpStream};
use variable_len_reader::{VariableReader, VariableWriter};

#[tokio::main]
async fn main() -> Result<()> {
    // Create tcp stream.
    let server = TcpListener::bind("localhost:0").await?;
    let mut client = TcpStream::connect(server.local_addr()?).await?;
    let (mut server, _) = server.accept().await?;
    
    // Prepare the protocol of tcp-handler and the ciphers.
    let client_init = client_init(&mut client, "test", "0.0.0").await;
    let server_init = server_init(&mut server, "test", |v| v == "0.0.0").await;
  let (server_cipher, _protocol_version, _client_version) =
          server_start(&mut server, "test", "0.0.0", server_init).await?;
    let client_cipher = client_start(&mut client, client_init).await?;
    
    // Send.
    let mut writer = BytesMut::new().writer();
    writer.write_string("hello server.")?;
    send(&mut client, &mut writer.into_inner(), &client_cipher).await?;
    
    // Receive.
    let mut reader = recv(&mut server, &server_cipher).await?.reader();
    let message = reader.read_string()?;
    assert_eq!("hello server.", message);
    
    // Send.
    let mut writer = BytesMut::new().writer();
    writer.write_string("hello client.")?;
    send(&mut client, &mut writer.into_inner(), &server_cipher).await?;
    
    // Receive.
    let mut reader = recv(&mut server, &client_cipher).await?.reader();
    let message = reader.read_string()?;
    assert_eq!("hello client.", message);
    
    Ok(())
}

The transmission method for compressed messages is similar to the above two, please use methods in compress and compress_encrypt mod.

Send discontinuous data chunks:

use anyhow::Result;
use bytes::{Buf, Bytes};
use tcp_handler::raw::{client_init, client_start, recv, send, server_init, server_start};
use tokio::net::{TcpListener, TcpStream};

#[tokio::main]
async fn main() -> Result<()> {
    // Connect
    let server = TcpListener::bind("localhost:0").await?;
    let mut client = TcpStream::connect(server.local_addr()?).await?;
    let (mut server, _) = server.accept().await?;
    let client_init = client_init(&mut client, "chain", "0").await;
    let server_init = server_init(&mut server, "chain", |v| v == "0").await;
    server_start(&mut server, "chain", "0", server_init).await?;
    client_start(&mut client, client_init).await?;

    // Using chain
    let mut messages = Bytes::from("a").chain(Bytes::from("b")).chain(Bytes::from("c"));
    send(&mut client, &mut messages).await?;
    let message = recv(&mut server).await?;
    assert_eq!(b"abc", message.as_ref());
    Ok(())
}

Protocol Version

The protocol version code used internally. Note only when the server and client sides have the same code, they can connect normally.

crate version	protocol version
>=0.6.0	1
<0.6.0	0

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Re-exports

• pub extern crate bytes;

Modules

• common
  Common utilities for this crate.
• compresscompression
  Compression protocol. Without encryption.
• compress_encryptcompress_encryption
  Compression and encryption protocol.
• config
  Global configuration for this crate.
• encryptencryption
  Encryption protocol. Without compression.
• raw
  Raw protocol. Without encryption and compression.

Structs

• Compression
  When compressing data, the compression level can be specified by a value in this struct.