断网后软路由无法自行恢复

[Smoovsky]

iptables-save:

# /etc/iptables/rules.v4
# Generated by iptables-save v1.8.7 on Sat Oct 15 07:01:36 2022
*mangle
:PREROUTING ACCEPT [156809900:52656925516]
:INPUT ACCEPT [675033404:1415875841055]
:FORWARD ACCEPT [125783295:27297409244]
:OUTPUT ACCEPT [340421458:1073329309978]
:POSTROUTING ACCEPT [466203410:1100626884908]
:DIVERT - [0:0]
:V2RAY - [0:0]
:V2RAY_MASK - [0:0]
-A PREROUTING -p tcp -m socket -j DIVERT
-A PREROUTING -j V2RAY
-A OUTPUT -j V2RAY_MASK
-A DIVERT -j MARK --set-xmark 0x1/0xffffffff
-A DIVERT -j ACCEPT
-A V2RAY -m mark --mark 0xff -j RETURN
-A V2RAY -d 127.0.0.0/24 -j RETURN
-A V2RAY -d 224.0.0.0/4 -j RETURN
-A V2RAY -d 255.255.255.255/32 -j RETURN
-A V2RAY -d 192.168.0.0/24 -p tcp -j RETURN
-A V2RAY -d 192.168.0.0/24 -p udp -j RETURN
-A V2RAY -p udp -j TPROXY --on-port 1088 --on-ip 127.0.0.1 --tproxy-mark 0x1/0xffffffff
-A V2RAY -p tcp -j TPROXY --on-port 1088 --on-ip 127.0.0.1 --tproxy-mark 0x1/0xffffffff
-A V2RAY_MASK -m conntrack --ctdir REPLY -j RETURN
-A V2RAY_MASK -m mark --mark 0xff -j RETURN
-A V2RAY_MASK -d 127.0.0.0/24 -j RETURN
-A V2RAY_MASK -d 224.0.0.0/4 -j RETURN
-A V2RAY_MASK -d 255.255.255.255/32 -j RETURN
-A V2RAY_MASK -d 192.168.0.0/24 -p tcp -j RETURN
-A V2RAY_MASK -d 192.168.0.0/24 -p udp -j RETURN
-A V2RAY_MASK -p udp -j MARK --set-xmark 0x1/0xffffffff
-A V2RAY_MASK -p tcp -j MARK --set-xmark 0x1/0xffffffff
COMMIT
# Completed on Sat Oct 15 07:01:36 2022
# Generated by iptables-save v1.8.7 on Sat Oct 15 07:01:36 2022
*filter
:INPUT ACCEPT [675033404:1415875841055]
:FORWARD ACCEPT [125783295:27297409244]
:OUTPUT ACCEPT [340418255:1073329020894]
COMMIT
# Completed on Sat Oct 15 07:01:36 2022
# Generated by iptables-save v1.8.7 on Sat Oct 15 07:01:36 2022
*nat
:PREROUTING ACCEPT [1757418:345266538]
:INPUT ACCEPT [1716224:342048401]
:OUTPUT ACCEPT [2375548:183301655]
:POSTROUTING ACCEPT [1402108:97775739]
-A POSTROUTING -s 192.168.0.0/24 ! -d 192.168.0.0/24 -o eth0 -j MASQUERADE
COMMIT
# Completed on Sat Oct 15 07:01:36 2022

Service Unit:

# /etc/systemd/system/tproxyrule.service
[Unit]
Description=Tproxy Rule
After=network.target

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/sbin/ip rule add fwmark 1 table 100 ; /sbin/ip route add local 0.0.0.0/0 dev lo table 100 ; /sbin/iptables-restore /etc/iptables/rules.v4
ExecStop=/sbin/iptables -t mangle -F ; /sbin/iptables -t nat -F ; iptables -F ; iptables -X ; /sbin/ip route del local 0.0.0.0/0 dev lo table 100 ; /sbin/ip rule del fwmark 1 table 100

[Install]
WantedBy=multi-user.target

现在的问题是每次断网之后（例如主路由器重启，运营商断流等），软路由就无法恢复过来。
局域网的TCP/UDP转发完全失效，软路由自身的直连似乎没有问题，但是代理就挂了。
需要systemctl restart tproxyrule.service重启路由规则之后才能恢复。

请问可能是什么原因导致的呢？

[mydogshitgold]

I'm using TPROXY like you are, but I haven't been able to reproduce said issue. When I hard reset my router, V2Ray typically bounces back in under 5 seconds.

Could you post your V2Ray configuration, especially the values of the uplinkOnly and downlinkOnly policies, as V2Ray typically restarts the proxy connection following the uplinkOnly time?

[Smoovsky]

I'm using TPROXY like you are, but I haven't been able to reproduce said issue. When I hard reset my router, V2Ray typically bounces back in under 5 seconds.

Could you post your V2Ray configuration, especially the values of the uplinkOnly and downlinkOnly policies, as V2Ray typically restarts the proxy connection following the uplinkOnly time?

I left all policy config to default.

Just did a bit further investigation:

1. restarting v2ray won't help itself to recover from the disconnected state.
2. disabling the tproxy rule in iptables(i.e. the side router just forward all traffic to masquerade chain) won't trigger this problem. There must be something wrong with tproxy.

Anyway, I managed to get around this with networkd-dispatcher:

#!/bin/bash

# /etc/networkd-dispatcher/routable.d/restartTproxy.sh

if systemctl is-active --quiet tproxyrule.service; then
    systemctl restart tproxyrule.service
fi