Merge pull request #30 from watermelo/feature/netutils

Add: add net ip match function

net/net.go

@@ -18,7 +18,9 @@
 package gxnet
 
 import (
+	"log"
 	"net"
+	"strconv"
 	"strings"
 )
 
@@ -30,6 +32,13 @@ var (
 	privateBlocks []*net.IPNet
 )
 
+const (
+	// Ipv4SplitCharacter use for slipt Ipv4
+	Ipv4SplitCharacter = "."
+	// Ipv6SplitCharacter use for slipt Ipv6
+	Ipv6SplitCharacter = ":"
+)
+
 func init() {
 	for _, b := range []string{"10.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16"} {
 		if _, block, err := net.ParseCIDR(b); err == nil {
@@ -175,3 +184,131 @@ func ListenOnUDPRandomPort(ip string) (*net.UDPConn, error) {
 
 	return net.ListenUDP("udp4", &localAddr)
 }
+
+// MatchIP is used to determine whether @pattern and @host:@port match, It's supports subnet/range
+func MatchIP(pattern, host, port string) bool {
+	// if the pattern is subnet format, it will not be allowed to config port param in pattern.
+	if strings.Contains(pattern, "/") {
+		_, subnet, _ := net.ParseCIDR(pattern)
+		return subnet != nil && subnet.Contains(net.ParseIP(host))
+	}
+	return matchIPRange(pattern, host, port)
+}
+
+func matchIPRange(pattern, host, port string) bool {
+	if pattern == "" || host == "" {
+		log.Print("Illegal Argument pattern or hostName. Pattern:" + pattern + ", Host:" + host)
+		return false
+	}
+
+	pattern = strings.TrimSpace(pattern)
+	if "*.*.*.*" == pattern || "*" == pattern {
+		return true
+	}
+
+	isIpv4 := true
+	ip4 := net.ParseIP(host).To4()
+
+	if ip4 == nil {
+		isIpv4 = false
+	}
+
+	hostAndPort := getPatternHostAndPort(pattern, isIpv4)
+	if hostAndPort[1] != "" && hostAndPort[1] != port {
+		return false
+	}
+
+	pattern = hostAndPort[0]
+	splitCharacter := Ipv4SplitCharacter
+	if !isIpv4 {
+		splitCharacter = Ipv6SplitCharacter
+	}
+
+	mask := strings.Split(pattern, splitCharacter)
+	// check format of pattern
+	if err := checkHostPattern(pattern, mask, isIpv4); err != nil {
+		log.Printf("gost/net check host pattern error: %s", err.Error())
+		return false
+	}
+
+	if pattern == host {
+		return true
+	}
+
+	// short name condition
+	if !ipPatternContains(pattern) {
+		return pattern == host
+	}
+
+	ipAddress := strings.Split(host, splitCharacter)
+	for i := 0; i < len(mask); i++ {
+		if "*" == mask[i] || mask[i] == ipAddress[i] {
+			continue
+		} else if strings.Contains(mask[i], "-") {
+			rangeNumStrs := strings.Split(mask[i], "-")
+			if len(rangeNumStrs) != 2 {
+				log.Print("There is wrong format of ip Address: " + mask[i])
+				return false
+			}
+			min := getNumOfIPSegment(rangeNumStrs[0], isIpv4)
+			max := getNumOfIPSegment(rangeNumStrs[1], isIpv4)
+			ip := getNumOfIPSegment(ipAddress[i], isIpv4)
+			if ip < min || ip > max {
+				return false
+			}
+		} else if "0" == ipAddress[i] && "0" == mask[i] || "00" == mask[i] || "000" == mask[i] || "0000" == mask[i] {
+			continue
+		} else if mask[i] != ipAddress[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func ipPatternContains(pattern string) bool {
+	return strings.Contains(pattern, "*") || strings.Contains(pattern, "-")
+}
+
+func checkHostPattern(pattern string, mask []string, isIpv4 bool) error {
+	if !isIpv4 {
+		if len(mask) != 8 && ipPatternContains(pattern) {
+			return perrors.New("If you config ip expression that contains '*' or '-', please fill qualified ip pattern like 234e:0:4567:0:0:0:3d:*. ")
+		}
+		if len(mask) != 8 && !strings.Contains(pattern, "::") {
+			return perrors.New("The host is ipv6, but the pattern is not ipv6 pattern : " + pattern)
+		}
+	} else {
+		if len(mask) != 4 {
+			return perrors.New("The host is ipv4, but the pattern is not ipv4 pattern : " + pattern)
+		}
+	}
+	return nil
+}
+
+func getPatternHostAndPort(pattern string, isIpv4 bool) []string {
+	result := make([]string, 2)
+	if strings.HasPrefix(pattern, "[") && strings.Contains(pattern, "]:") {
+		end := strings.Index(pattern, "]:")
+		result[0] = pattern[1:end]
+		result[1] = pattern[end+2:]
+	} else if strings.HasPrefix(pattern, "[") && strings.HasSuffix(pattern, "]") {
+		result[0] = pattern[1 : len(pattern)-1]
+		result[1] = ""
+	} else if isIpv4 && strings.Contains(pattern, ":") {
+		end := strings.Index(pattern, ":")
+		result[0] = pattern[:end]
+		result[1] = pattern[end+1:]
+	} else {
+		result[0] = pattern
+	}
+	return result
+}
+
+func getNumOfIPSegment(ipSegment string, isIpv4 bool) int {
+	if isIpv4 {
+		ipSeg, _ := strconv.Atoi(ipSegment)
+		return ipSeg
+	}
+	ipSeg, _ := strconv.ParseInt(ipSegment, 0, 16)
+	return int(ipSeg)
+}

net/net_test.go

@@ -87,3 +87,45 @@ func TestListenOnUDPRandomPort(t *testing.T) {
 		l.Close()
 	}
 }
+
+func TestMatchIpIpv4Equal(t *testing.T) {
+	assert.True(t, MatchIP("192.168.0.1:8080", "192.168.0.1", "8080"))
+	assert.False(t, MatchIP("192.168.0.1:8081", "192.168.0.1", "8080"))
+	assert.True(t, MatchIP("*", "192.168.0.1", "8080"))
+	assert.True(t, MatchIP("*", "192.168.0.1", ""))
+	assert.True(t, MatchIP("*.*.*.*", "192.168.0.1", "8080"))
+	assert.False(t, MatchIP("*", "", ""))
+}
+
+func TestMatchIpIpv4Subnet(t *testing.T) {
+	assert.True(t, MatchIP("206.0.68.0/23", "206.0.68.123", "8080"))
+	assert.False(t, MatchIP("206.0.68.0/23", "207.0.69.123", "8080"))
+}
+
+func TestMatchIpIpv4Range(t *testing.T) {
+	assert.True(t, MatchIP("206.*.68.0", "206.0.68.0", "8080"))
+	assert.False(t, MatchIP("206.*.68.0", "206.0.69.0", "8080"))
+	assert.True(t, MatchIP("206.0.68-69.0", "206.0.68.0", "8080"))
+	assert.False(t, MatchIP("206.0.68-69.0", "206.0.70.0", "8080"))
+}
+
+func TestMatchIpIpv6Equal(t *testing.T) {
+	assert.True(t, MatchIP("[1fff:0:a88:85a3::ac1f]:8080", "1fff:0:a88:85a3::ac1f", "8080"))
+	assert.False(t, MatchIP("[1fff:0:a88:85a3::ac1f]:8081", "1fff:0:a88:85a3::ac1f", "8080"))
+	assert.True(t, MatchIP("*", "1fff:0:a88:85a3::ac1f", "8080"))
+	assert.True(t, MatchIP("*", "1fff:0:a88:85a3::ac1f", ""))
+	assert.True(t, MatchIP("*.*.*.*", "1fff:0:a88:85a3::ac1f", "8080"))
+	assert.False(t, MatchIP("*", "", ""))
+}
+
+func TestMatchIpIpv6Subnet(t *testing.T) {
+	assert.True(t, MatchIP("1fff:0:a88:85a3::ac1f/64", "1fff:0000:0a88:85a3:0000:0000:0000:0000", "8080"))
+	assert.False(t, MatchIP("1fff:0:a88:85a3::ac1f/64", "2fff:0000:0a88:85a3:0000:0000:0000:0000", "8080"))
+}
+
+func TestMatchIpIpv6Range(t *testing.T) {
+	assert.True(t, MatchIP("234e:0:4567:0:0:0:3d:*", "234e:0:4567:0:0:0:3d:4", "8080"))
+	assert.False(t, MatchIP("234e:0:4567:0:0:0:3d:*", "234e:0:4567:0:0:0:2d:4", "8080"))
+	assert.True(t, MatchIP("234e:0:4567:0:0:0:3d:1-2", "234e:0:4567:0:0:0:3d:1", "8080"))
+	assert.False(t, MatchIP("234e:0:4567:0:0:0:3d:1-2", "234e:0:4567:0:0:0:3d:3", "8080"))
+}