Loopback outbound: Add "sniffing"

[j2rong4cn]

为Loopback出站添加流量探测
示例：tun入站白名单

{
  "routing": {
    "rules": [
      {
        "inboundTag": ["tun-in"],
        "process": ["chrome", "firefox"],
        "outboundTag": "loopback-out"
      },
      {
        "inboundTag": ["tun-in"],
        "outboundTag": "direct"
      }
    ]
  },
  "inbounds": [
    {
      "protocol": "tun",
      "settings": {
        "name": "xray0",
        "mtu": 1500,
        "gateway": ["10.0.0.1/16", "fc00::1/64"],
        "dns": ["1.1.1.1"],
        "autoSystemRoutingTable": ["0.0.0.0/0", "::/0"],
        "autoOutboundsInterface": "auto"
      },
      "tag": "tun-in"
    }
  ],
  "outbounds": [
    {
      "protocol": "loopback",
      "settings": {
        "sniffing": {
          "destOverride": ["http", "tls", "quic"],
          "routeOnly": true,
          "enabled": true
        },
        "inboundTag": "loopback-in"
      },
      "tag": "loopback-out"
    }
  ]
}

[Fangliding]

tun也有嗅探功能啊 为什么要扔loopback上

[j2rong4cn]

tun也有嗅探功能啊 为什么要扔loopback上

减少不必要的嗅探开销呗

[Fangliding]

sniff能有多少开销 看开头一个包而已 有gvisor TUN零头吗

[patterniha]

@Fangliding
Apart from this, can you tell me another use for loopback? i thought about it a bit but couldn't find any use.

[Meo597]

routing.balancers.fallbackTag 只能是出站，但借由 loopback 可以到另一个 balancer

[Fangliding]

sniff能有多少开销 看开头一个包而已 有gvisor TUN零头吗

如果没有异议的话就算了 因为loopback出站再走一次dispatcher也不是零开销的 后续数据都要多倒一手