Simon Zolin 579177fc70 Merge: * DNS: use "unrestricted" Quad9 servers; - dnsfilter: fix hanging on error
Close #1451

Squashed commit of the following:

commit 91e5c98d7543b7c8872cc494818d66bb823ec7c0
Author: Simon Zolin <s.zolin@adguard.com>
Date:   Thu Mar 5 13:09:01 2020 +0300

    fix

commit 4f80865e55f27206fa9cef1d72fb3652498da582
Author: Simon Zolin <s.zolin@adguard.com>
Date:   Thu Mar 5 13:08:31 2020 +0300

    * fix race-detector issue

commit 5513c6c12c112c8f9325dbc8a8d09e58fe7611e0
Author: Simon Zolin <s.zolin@adguard.com>
Date:   Thu Mar 5 13:01:46 2020 +0300

    - dnsfilter: fix hanging on error

commit c7b81286833a523349efb8ca972eba3540518944
Author: Simon Zolin <s.zolin@adguard.com>
Date:   Thu Mar 5 12:42:19 2020 +0300

    * DNS: use "unrestricted" Quad9 servers
2020-03-05 13:12:21 +03:00
..
2019-01-25 20:13:57 +03:00
2019-11-08 13:07:25 +03:00

AdGuard Home's DNS filtering go library

Example use:

[ -z "$GOPATH" ] && export GOPATH=$HOME/go
go get -d github.com/AdguardTeam/AdGuardHome/dnsfilter

Create file filter.go

package main

import (
    "github.com/AdguardTeam/AdGuardHome/dnsfilter"
    "log"
)

func main() {
    filter := dnsfilter.New()
    filter.AddRule("||dou*ck.net^")
    host := "www.doubleclick.net"
    res, err := filter.CheckHost(host)
    if err != nil {
        // temporary failure
        log.Fatalf("Failed to check host '%s': %s", host, err)
    }
    if res.IsFiltered {
        log.Printf("Host %s is filtered, reason - '%s', matched rule: '%s'", host, res.Reason, res.Rule)
    } else {
        log.Printf("Host %s is not filtered, reason - '%s'", host, res.Reason)
    }
}

And then run it:

go run filter.go

You will get:

2000/01/01 00:00:00 Host www.doubleclick.net is filtered, reason - 'FilteredBlackList', matched rule: '||dou*ck.net^'

You can also enable checking against AdGuard's SafeBrowsing:

package main

import (
    "github.com/AdguardTeam/AdGuardHome/dnsfilter"
    "log"
)

func main() {
    filter := dnsfilter.New()
    filter.EnableSafeBrowsing()
    host := "wmconvirus.narod.ru" // hostname for testing safebrowsing
    res, err := filter.CheckHost(host)
    if err != nil {
        // temporary failure
        log.Fatalf("Failed to check host '%s': %s", host, err)
    }
    if res.IsFiltered {
        log.Printf("Host %s is filtered, reason - '%s', matched rule: '%s'", host, res.Reason, res.Rule)
    } else {
        log.Printf("Host %s is not filtered, reason - '%s'", host, res.Reason)
    }
}