# dae

<img src="https://github.com/v2rayA/dae/blob/main/logo.png" border="0" width="25%">

***dae***, means goose, is a lightweight and high-performance transparent proxy solution.

In order to improve the traffic diversion performance as much as possible, dae runs the transparent proxy and traffic diversion suite in the linux kernel by eBPF. Therefore, we have the opportunity to make the direct traffic bypass the forwarding by proxy application and achieve true direct traffic through. Under such a magic trick, there is almost no performance loss and additional resource consumption for direct traffic.

As a successor of [v2rayA](https://github.com/v2rayA/v2rayA), dae abandoned v2ray-core to meet the needs of users more freely.

## Usage

Build:
```shell
git clone https://github.com/v2rayA/dae.git
cd dae
git submodule update --init
make
```

Run:
```shell
./dae run -c example.dae
```

See [example.dae](https://github.com/v2rayA/dae/blob/main/example.dae).

## Linux Kernel Requirement

### Kernel Version

Use `uname -r` to check the kernel version on your machine.

**Bind to LAN: >= 5.2**

You need bind dae to LAN interface, if you want to provide network service for LAN as an intermediate device.

This feature requires the kernel version of machine on which dae install >= 5.2.

Note that if you bind dae to LAN only, dae only provide network service for traffic from LAN, and not impact local programs.

**Bind to WAN: >= 5.5**

You need bind dae to WAN interface, if you want dae to provide network service for local programs.

This feature requires kernel version of the machine >= 5.5.

Note that if you bind dae to WAN only, dae only provide network service for local programs and not impact traffic coming in from other interfaces.

### Kernel Configuration Item

Usually, mainstream desktop distributions have these items turned on. But on embedded Linux distributions like OpenWRT, Armbian, etc, in order to reduce kernel size, some items are turned off by default. You need to re-compile the kernel and turn them on.

Use following commands to check the kernel configuration items on your machine.

```shell
zcat /proc/config.gz || cat /boot/config || cat /boot/config-$(uname -r)
```

**Bind to LAN**

```
CONFIG_DEBUG_INFO_BTF
```

**Bind to WAN**:

```
CONFIG_DEBUG_INFO_BTF

CONFIG_FUNCTION_TRACER
CONFIG_FUNCTION_GRAPH_TRACER
CONFIG_STACK_TRACER
CONFIG_DYNAMIC_FTRACE
```

Check them using command like:

```shell
(zcat /proc/config.gz || cat /boot/config || cat /boot/config-$(uname -r)) | grep -E '(CONFIG_DEBUG_INFO_BTF|CONFIG_STACK_TRACER|CONFIG_FUNCTION_TRACER|CONFIG_FUNCTION_GRAPH_TRACER|CONFIG_STACK_TRACER|CONFIG_DYNAMIC_FTRACE)='
```

## TODO

1. Check dns upstream and source loop (whether upstream is also a client of us) and remind the user to add sip rule.
1. Domain routing performance optimization.
1. DisableL4Checksum by link.
1. Handle the case that nodes do not support UDP.
1. L4Checksum problem.
1. MACv2 extension extraction.
1. ...