socks5 udp连接 复用同一个连接时连接失败

[fanyiguang]

Operating system

Windows

System version

Windows 10 家庭中文版

Installation type

Original sing-box Command Line

If you are using a graphical client, please provide the version of the client.

无

Version

sing-box version 1.8.2

Environment: go1.21.5 windows/amd64
Tags: with_gvisor,with_dhcp,with_reality_server,with_clash_api,with_quic,with_ech,with_utls
Revision: 7fd0726ab8c5a4588f3710590b3bbb9cfca653f4
CGO: enabled

Description

配置udp dns detour为socks5 outbound并且设置disable_cache=true时，第一次dns解析成功后，第二次解析必定失败。

Reproduction

{
"log": {
"disabled": false,
"level": "debug",
"output": "",
"timestamp": true
},
"dns": {
"servers": [
{
"tag": "remote",
"address": "udp://114.114.114.114",
"detour": "socks-out"
}
],
"final": "remote",
"strategy": "ipv4_only",
"disable_cache": true
},
"inbounds": [
{
"type": "socks",
"tag": "socks-in",
"listen": "127.0.0.1",
"listen_port": 8989,
"domain_strategy": "ipv4_only",
"users": [
{
"username": "admin",
"password": "123"
}
]
}
],
"outbounds": [
{
"type": "direct",
"tag": "direct-out"
},
{
"type": "socks",
"tag": "socks-out",
"server": "127.0.0.1",
"server_port": 18882,
"username": "admin",
"password": "123",
"version": "5"
},
{
"type": "dns",
"tag": "dns-out"
},
{
"type": "block",
"tag": "block"
}
],
"route": {
"rules": [
{
"inbound": [
"socks-in"
],
"outbound": "direct-out"
}
]
}
}

Logs

+0800 2024-05-10 20:02:07 INFO router: updated default interface WLAN, index 4
+0800 2024-05-10 20:02:07 INFO inbound/socks[socks-in]: tcp server started at 127.0.0.1:8989
+0800 2024-05-10 20:02:07 INFO sing-box started (0.22s)
+0800 2024-05-10 20:02:51 INFO [2281251229 0ms] inbound/socks[socks-in]: inbound connection from 127.0.0.1:17467
+0800 2024-05-10 20:02:51 INFO [2281251229 0ms] inbound/socks[socks-in]: [admin] inbound connection to ipinfo.io:80
+0800 2024-05-10 20:02:51 DEBUG [2281251229 1ms] dns: lookup domain ipinfo.io
+0800 2024-05-10 20:02:55 INFO outbound/socks[socks-out]: outbound packet connection to 114.114.114.114:53
+0800 2024-05-10 20:03:00 DEBUG [2281251229 8.42s] dns: exchanged ipinfo.io NOERROR 34
+0800 2024-05-10 20:03:00 INFO [2281251229 8.42s] dns: exchanged ipinfo.io A ipinfo.io. 34 IN A 34.117.186.192
+0800 2024-05-10 20:03:00 INFO [2281251229 8.42s] dns: lookup succeed for ipinfo.io: 34.117.186.192
+0800 2024-05-10 20:03:00 DEBUG [2281251229 8.42s] dns: resolved [34.117.186.192]
+0800 2024-05-10 20:03:00 DEBUG [2281251229 8.42s] router: match[0] inbound=socks-in => direct-out
+0800 2024-05-10 20:03:00 INFO [2281251229 8.42s] outbound/direct[direct-out]: outbound connection to ipinfo.io:80
+0800 2024-05-10 20:03:07 INFO [1160678508 0ms] inbound/socks[socks-in]: inbound connection from 127.0.0.1:17473
+0800 2024-05-10 20:03:07 INFO [1160678508 0ms] inbound/socks[socks-in]: [admin] inbound connection to ipinfo.io:80
+0800 2024-05-10 20:03:07 DEBUG [1160678508 0ms] dns: lookup domain ipinfo.io
+0800 2024-05-10 20:03:17 ERROR [1160678508 10.1s] dns: lookup failed for ipinfo.io: context deadline exceeded

Supporter

• I am a sponsor

Integrity requirements

• I confirm that I have read the documentation, understand the meaning of all the configuration items I wrote, and did not pile up seemingly useful options or default values.
• I confirm that I have provided the server and client configuration files and process that can be reproduced locally, instead of a complicated client configuration file that has been stripped of sensitive data.
• I confirm that I have provided the simplest configuration that can be used to reproduce the error I reported, instead of depending on remote servers, TUN, graphical interface clients, or other closed-source software.
• I confirm that I have provided the complete configuration files and logs, rather than just providing parts I think are useful out of confidence in my own intelligence.

[nekohasekai]

SOCKS5 UDP ports are not designed to be reused by multiple clients

[dyhkwong]

I think this ia a valid issue. In the case of this issue, SOCKS5 UDP port is reused by sing-box itself . And it is okay to reuse UDP bind address (like STUN).
See SagerNet/sing#66 (comment).