Optimized ip checking algorithm

internal/tools/ipparser.go

@@ -6,7 +6,6 @@ import (
 )
 
 var (
-	ipv4re0 *regexp.Regexp
 	ipv4re *regexp.Regexp
 
 	ipv6re0 *regexp.Regexp
@@ -14,21 +13,44 @@ var (
 )
 
 func init() {
-	ipv4re0 = regexp.MustCompile(`^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$`)
 	ipv4re = regexp.MustCompile(`(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}`)
 
 	ipv6re0 = regexp.MustCompile(`^fe80:(:[0-9a-fA-F]{1,4}){0,4}(%\w+)?|([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}|(([0-9a-fA-F]{1,4}:){0,6}[0-9a-fA-F]{1,4})?::(([0-9a-fA-F]{1,4}:){0,6}[0-9a-fA-F]{1,4})?$`)
 	ipv6re = regexp.MustCompile(`fe80:(:[0-9a-fA-F]{1,4}){0,4}(%\w+)?|([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}|(([0-9a-fA-F]{1,4}:){0,6}[0-9a-fA-F]{1,4})?::(([0-9a-fA-F]{1,4}:){0,6}[0-9a-fA-F]{1,4})?`)
 }
 
-func ValidIP4(str string) bool {
-	str = strings.Trim(str, " ")
-	return ipv4re0.MatchString(str)
+func ValidIP4(IP string) bool {
+	arr := strings.Split(IP, ".")
+	if len(arr) != 4 {
+		return false
+	}
+	for _, elem := range arr {
+		if elem == "" {
+			return false
+		}
+		if len(elem) > 1 && elem[0] == '0' {
+			return false
+		}
+		num := 0
+		for _, c := range elem {
+			if c >= '0' && c <= '9' {
+				num = num*10 + int(c-'0')
+			} else {
+				return false
+			}
+		}
+		if num > 255 {
+			return false
+		}
+	}
+	return true
 }
 
 func ValidIP6(str string) bool {
 	str = strings.Trim(str, " ")
 	return ipv6re0.MatchString(str)
+
+	//return isIPV6(str)
 }
 
 func GetIP4FromString(str string) []string {
@@ -40,3 +62,29 @@ func GetIP6FromString(str string) []string {
 	str = strings.Trim(str, " ")
 	return ipv6re.FindAllString(str, -1)
 }
+
+//IPV6地址的判断：
+//1. 用“：”分割字符串，若长度不等于8，则return Neither
+//2. 遍历每一个数组的每一个元素，若元素的长度大于4，则return Neither
+//3. 判断每一个元素的字符，若出现非0-9，A-F的字符，则return Neither
+func isIPV6(IP string) bool {
+	IP = strings.ToUpper(IP)
+	arr := strings.Split(IP, ":")
+	if len(arr) != 8 {
+		return false
+	}
+	for _, elem := range arr {
+		if elem == "" || len(elem) > 4 {
+			return false
+		}
+
+		for _, c := range elem {
+			if (c >= '0' && c <= '9') || (c >= 'A' && c <= 'F') {
+				continue
+			} else {
+				return false
+			}
+		}
+	}
+	return true
+}

internal/tools/iptools_test.go

@@ -10,3 +10,59 @@ func TestIP4Re(t *testing.T) {
 	fmt.Println(GetIP4FromString(str))
 	fmt.Println(ValidIP4(str))
 }
+
+func TestValidIP6(t *testing.T) {
+	ipv6Valid := []string{
+		"1:2:3:4:5:6:7::",
+		"1:2:3:4:5:6:7:8",
+
+		"1:2:3:4:5:6::",
+		"1:2:3:4:5:6::8",
+
+		"1:2:3:4:5::",
+		"1:2:3:4:5::8",
+
+		"1:2:3:4::",
+		"1:2:3:4::8",
+
+		"1:2:3::",
+		"1:2:3::8",
+
+		"1:2::",
+		"1:2::8",
+
+		"1::",
+		"1::8",
+
+		"::",
+		"::8",
+		"::7:8",
+		"::6:7:8",
+		"::5:6:7:8",
+		"::4:5:6:7:8",
+		"::3:4:5:6:7:8",
+		"::2:3:4:5:6:7:8",
+
+		"::192.168.1.1",
+		"::ffff:135.75.43.52",
+		"A:0f:0F:FFFF:5:6:7:8",
+	}
+
+	ipv6Invalid := []string{
+		"A:0f:0F:FFFF1:5:6:7:8",
+		"G:0f:0F:FFFF:5:6:7:8",
+		"2001::25de::cade",
+	}
+
+	for _, i := range ipv6Valid {
+		if !ValidIP6(i) {
+			t.Log("valid:", i)
+		}
+	}
+
+	for _, i := range ipv6Invalid {
+		if ValidIP6(i) {
+			t.Log("invalid:", i)
+		}
+	}
+}