Chore: optimizing IPtoPTR function implementation

fxzxmicah · Mar 7, 2024 · 0e66644 · 0e66644
1 parent 62020bc
commit 0e66644
Showing 1 changed file with 4 additions and 4 deletions.
diff --git a/dns/util.go b/dns/util.go
@@ -4,8 +4,8 @@ import (
 	"context"
 	"crypto/tls"
 	"errors"
-	"fmt"
 	"net"
+	"strcon"
 	"strings"
 	"time"
 	"unicode/utf8"
@@ -159,13 +159,13 @@ func containNonASCII(s string) bool {
 func IPtoPTR(ip net.IP) string {
 	if v4 := ip.To4(); v4 != nil {
 		// IPv4
-		return fmt.Sprintf("%d.%d.%d.%d.in-addr.arpa", v4[3], v4[2], v4[1], v4[0])
+		return strconv.Itoa(int(v4[3])) + "." + strconv.Itoa(int(v4[2])) + "." + strconv.Itoa(int(v4[1])) + "." + strconv.Itoa(int(v4[0])) + ".in-addr.arpa"
 	} else {
 		// IPv6
 		ptr := make([]string, len(ip)*2)
 		for i := 0; i < len(ip); i++ {
-			ptr[i*2] = fmt.Sprintf("%x", ip[len(ip)-i-1]&0xF)
-			ptr[i*2+1] = fmt.Sprintf("%x", ip[len(ip)-i-1]>>4)
+			ptr[i*2] = strconv.FormatInt(int64(ip[len(ip)-i-1]&0xF), 16)
+			ptr[i*2+1] = strconv.FormatInt(int64(ip[len(ip)-i-1]>>4), 16)
 		}
 		return strings.Join(ptr, ".") + ".ip6.arpa"
 	}