some library updates and adds support for adblock lists

cmd/bind/parsing-adblock.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"regexp"
+
+	"github.com/asaskevich/govalidator"
+
+	"gitlab.smoothnet.org/nhyatt/bind-response-policy-zone-creator/internal/log"
+)
+
+func parseAdBlock(data []byte) []string {
+	var domains []string
+
+	// convert data to reader for line-by-line reading
+	r := bytes.NewReader(data)
+
+	// process combined files line-by-line
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		// skip lines with the AdBlock header
+		if regexp.MustCompile(`^\[Adblock Plus\]`).MatchString(line) {
+			continue
+		}
+
+		// skip lines where the first non-whitespace character is '#' or '//'
+		if regexp.MustCompile(`^(\s+)?(#|\/\/|\!)`).MatchString(line) {
+			continue
+		}
+
+		// skip lines with no characters and/or whitespace only
+		if regexp.MustCompile(`^(\s+)?$`).MatchString(line) {
+			continue
+		}
+
+		// remove line header
+		d := regexp.MustCompile(`^\|\|`).ReplaceAllString(line, "")
+
+		// remove line footer
+		d = regexp.MustCompile(`\^$`).ReplaceAllString(d, "")
+
+		if govalidator.IsDNSName(d) {
+			domains = append(domains, d)
+		} else {
+			log.Debug("host invalid", "host", d)
+		}
+	}
+
+	return domains
+}