badguardhome/dnsfilter/helpers.go

79 lines
1.4 KiB
Go

package dnsfilter
import (
"fmt"
"os"
"path"
"runtime"
"strings"
"sync/atomic"
)
func isValidRule(rule string) bool {
if len(rule) < 4 {
return false
}
if rule[0] == '!' {
return false
}
if rule[0] == '#' {
return false
}
if strings.HasPrefix(rule, "[Adblock") {
return false
}
// Filter out all sorts of cosmetic rules:
// https://kb.adguard.com/en/general/how-to-create-your-own-ad-filters#cosmetic-rules
masks := []string{
"##",
"#@#",
"#?#",
"#@?#",
"#$#",
"#@$#",
"#?$#",
"#@?$#",
"$$",
"$@$",
"#%#",
"#@%#",
}
for _, mask := range masks {
if strings.Contains(rule, mask) {
return false
}
}
return true
}
func updateMax(valuePtr *int64, maxPtr *int64) {
for {
current := atomic.LoadInt64(valuePtr)
max := atomic.LoadInt64(maxPtr)
if current <= max {
break
}
swapped := atomic.CompareAndSwapInt64(maxPtr, max, current)
if swapped {
break
}
// swapping failed because value has changed after reading, try again
}
}
func trace(format string, args ...interface{}) {
pc := make([]uintptr, 10) // at least 1 entry needed
runtime.Callers(2, pc)
f := runtime.FuncForPC(pc[0])
var buf strings.Builder
buf.WriteString(fmt.Sprintf("%s(): ", path.Base(f.Name())))
text := fmt.Sprintf(format, args...)
buf.WriteString(text)
if len(text) == 0 || text[len(text)-1] != '\n' {
buf.WriteRune('\n')
}
fmt.Fprint(os.Stderr, buf.String())
}