[Bug] <代理的域名解析应考虑TTL>

kwokpia commented 8 months ago

先决条件

[X] 我了解这里是开源版 Clash.Rev 核心仓库
[X] 我要提交 Clash.Rev 核心的问题，并非 Clash.Meta / OpenClash / ClashX / Clash For Windows 或其他任何衍生版本的问题
[X] 我使用的是本仓库最新版本的 Clash.Rev 内核
[X] 我已经在 Issue Tracker 中找过我要提出的 bug，并且没有找到相关问题
[X] 我已经仔细阅读官方 Wiki 并无法自行解决问题

版本

clash.rev-linux-amd64-cgo-v1.0.2

适用的作业系统

Linux

适用的硬件架构

amd64

配置文件

proxy-providers:
  airportA:
    type: http
    url: https://xxx
    interval: 3600
    path: ./airportA.yaml
    health-check:
      enable: true
      interval: 36000
      url: http://www.gstatic.com/generate_204
dns:
  enable: true
  listen: 0.0.0.0:53
  ipv6: true
  default-nameserver:
    - 192.168.1.1
  enhanced-mode: fake-ip
  fake-ip-range: 198.18.0.1/16
  fake-ip-filter:
    - '+.lan'
    - '+.local'
    - '+.time.google.com'
    - '+.ntp.ubuntu.com'
    - '+.ntp.org'
    - '+.time.apple.com'
  nameserver:
    - 192.168.1.1
  fallback:
    - dot.pub
  fallback-filter:
    geoip: false
    ipcidr:
      - 240.0.0.0/4
      - 0.0.0.0/32
      - 127.0.0.1/32

airportA.yaml
proxies:
  - name: 香港-广东专线 DP 1
    type: trojan
    server: example.com
    port: xxx
    password: xxx
    udp: true
    sni: xxx
#假设代理的域名为example.com,

日志输出

curl --socks5 localhost:7890 twitter.com
DEBU[2023-11-17T20:37:08.55655162+08:00] [Rule] use default rules                     
DEBU[2023-11-17T20:37:08.556841049+08:00] [DNS] resolve example.com from udp://192.168.1.1:53 
DEBU[2023-11-17T20:37:08.556952185+08:00] [DNS] resolve example.com from udp://192.168.1.1:53 
DEBU[2023-11-17T20:37:08.564788831+08:00] [DNS] example.com --> [x.x.x.x] A from udp://192.168.1.1:53 
DEBU[2023-11-17T20:37:08.568433889+08:00] [DNS] example.com --> [] AAAA from udp://192.168.1.1:53 
DEBU[2023-11-17T20:37:08.568550605+08:00] [DNS] resolve example.com from udp://dot.pub:53 
DEBU[2023-11-17T20:37:08.56865657+08:00] [DNS] resolve dot.pub from udp://192.168.1.1:53 
DEBU[2023-11-17T20:37:08.577520333+08:00] [DNS] dot.pub --> [1.12.34.56] A from udp://192.168.1.1:53 
INFO[2023-11-17T20:37:08.712748267+08:00] [TCP] 127.0.0.1:34738 --> twitter.com:80 match RuleSet(proxy-domain) using common-S[🇭🇰 香港-广东专线 DP 1] 

curl --socks5 localhost:7890 facebook.com
DEBU[2023-11-17T20:37:30.743053713+08:00] [Rule] use default rules                     
DEBU[2023-11-17T20:37:30.743463835+08:00] [DNS] resolve example.com from udp://192.168.1.1:53 
DEBU[2023-11-17T20:37:30.744350285+08:00] [DNS] example.com --> [] AAAA from udp://192.168.1.1:53 
DEBU[2023-11-17T20:37:30.744432303+08:00] [DNS] resolve example.com from udp://dot.pub:53 
INFO[2023-11-17T20:37:31.007169327+08:00] [TCP] 127.0.0.1:48846 --> facebook.com:80 match RuleSet(proxy-domain) using common-S[🇭🇰 香港-广东专线 DP 1]

问题描述

每建立一个连接都会重新解析代理的域名,即使代理的域名的TTl还没到期. 如日志所示,连续的两次建立连接都去解析了example.com的DNS.

复现步骤

No response

MerlinKodo commented 8 months ago

@kwokpia

你好，Clash内部使用了In memory cache来缓存DNS解析结果，具体的缓存功能相关代码在

https://github.com/MerlinKodo/clash-rev/blob/dev/common/cache/lrucache.go https://github.com/MerlinKodo/clash-rev/blob/dev/dns/resolver.go

更具体的来说，resolver.go文件的ExchangeContext函数中实现了相关Cache查询功能

此外通过添加额外的debug日志可以看到如下记录：


time="2023-11-18T01:31:36.2150395-08:00" level=debug msg="[Rule] use default rules"

Time:  2023-11-18 01:31:36 Debug Query:  ;twitter.com.  IN       A
Time:  2023-11-18 01:31:36 Not hit cache for:  ;twitter.com.    IN       A     
Time:  2023-11-18 01:31:36 Debug Query:  ;twitter.com.  IN       AAAA
Time:  2023-11-18 01:31:36 Not hit cache for:  ;twitter.com.    IN       AAAA  

time="2023-11-18T01:31:36.2155446-08:00" level=debug msg="[DNS] resolve twitter.com from udp://x.x.x.x:53"
time="2023-11-18T01:31:36.2160711-08:00" level=debug msg="[DNS] resolve twitter.com from udp://x.x.x.x:53"
time="2023-11-18T01:31:36.2196092-08:00" level=debug msg="[DNS] twitter.com --> [x.x.x.x] A from udp://x.x.x.x:53"
time="2023-11-18T01:31:36.2229242-08:00" level=debug msg="[DNS] twitter.com --> [] AAAA from udp://x.x.x.x:53"
time="2023-11-18T01:31:36.2229242-08:00" level=debug msg="[DNS] twitter.com --> x.x.x.x"
time="2023-11-18T01:31:37.2951361-08:00" level=info msg="[TCP]  --> twitter.com:443 match Match using PROXY"

time="2023-11-18T01:32:27.4310225-08:00" level=debug msg="[Rule] use default rules"

Time:  2023-11-18 01:32:27 Debug Query:  ;www.twitter.com.      IN       A
Time:  2023-11-18 01:32:27 Hit cache for:  ;www.twitter.com.    IN       A
Time:  2023-11-18 01:32:27 Debug Query:  ;www.twitter.com.      IN       AAAA
Time:  2023-11-18 01:32:27 Hit cache for:  ;www.twitter.com.    IN       AAAA

time="2023-11-18T01:32:27.4315287-08:00" level=debug msg="[DNS] www.twitter.com --> x.x.x.x"
time="2023-11-18T01:32:28.4678944-08:00" level=info msg="[TCP]  --> www.twitter.com:443 match Match using PROXY"

可见第二次请求中使用了缓存结果，而没有发起新的DNS请求

kwokpia commented 8 months ago

@kwokpia

你好，Clash内部使用了In memory cache来缓存DNS解析结果，具体的缓存功能相关代码在

dev/common/cache/lrucache.go dev/dns/resolver.go

更具体的来说，resolver.go文件的ExchangeContext函数中实现了相关Cache查询功能

此外通过添加额外的debug日志可以看到如下记录：


time="2023-11-18T01:31:36.2150395-08:00" level=debug msg="[Rule] use default rules"

Time:  2023-11-18 01:31:36 Debug Query:  ;twitter.com.  IN       A
Time:  2023-11-18 01:31:36 Not hit cache for:  ;twitter.com.    IN       A     
Time:  2023-11-18 01:31:36 Debug Query:  ;twitter.com.  IN       AAAA
Time:  2023-11-18 01:31:36 Not hit cache for:  ;twitter.com.    IN       AAAA  

time="2023-11-18T01:31:36.2155446-08:00" level=debug msg="[DNS] resolve twitter.com from udp://x.x.x.x:53"
time="2023-11-18T01:31:36.2160711-08:00" level=debug msg="[DNS] resolve twitter.com from udp://x.x.x.x:53"
time="2023-11-18T01:31:36.2196092-08:00" level=debug msg="[DNS] twitter.com --> [x.x.x.x] A from udp://x.x.x.x:53"
time="2023-11-18T01:31:36.2229242-08:00" level=debug msg="[DNS] twitter.com --> [] AAAA from udp://x.x.x.x:53"
time="2023-11-18T01:31:36.2229242-08:00" level=debug msg="[DNS] twitter.com --> x.x.x.x"
time="2023-11-18T01:31:37.2951361-08:00" level=info msg="[TCP]  --> twitter.com:443 match Match using PROXY"

time="2023-11-18T01:32:27.4310225-08:00" level=debug msg="[Rule] use default rules"

Time:  2023-11-18 01:32:27 Debug Query:  ;www.twitter.com.      IN       A
Time:  2023-11-18 01:32:27 Hit cache for:  ;www.twitter.com.    IN       A
Time:  2023-11-18 01:32:27 Debug Query:  ;www.twitter.com.      IN       AAAA
Time:  2023-11-18 01:32:27 Hit cache for:  ;www.twitter.com.    IN       AAAA

time="2023-11-18T01:32:27.4315287-08:00" level=debug msg="[DNS] www.twitter.com --> x.x.x.x"
time="2023-11-18T01:32:28.4678944-08:00" level=info msg="[TCP]  --> www.twitter.com:443 match Match using PROXY"

可见第二次请求中使用了缓存结果，而没有发起新的DNS请求

感谢回复

MerlinKodo / clash-rev