Merge pull request #470 from vr-varad/fix/add_random_functions

Fix: Add random functions (ipv4 and ipv6)

Author: j-baines

random/random.go

@@ -152,6 +152,44 @@ func RandIPv4() net.IP {
 	)
 }
 
+// RandIPv4Private Generates a random private IPv4 address.
+func RandIPv4Private() net.IP {
+	n, _ := rand.Int(rand.Reader, big.NewInt(3))
+	switch n.Int64() {
+	case 0:
+		return net.IPv4(
+			10,
+			byte(RandIntRange(1, 256)),
+			byte(RandIntRange(1, 256)),
+			byte(RandIntRange(1, 256)),
+		)
+	case 1:
+		return net.IPv4(
+			172,
+			byte(RandIntRange(16, 32)),
+			byte(RandIntRange(1, 256)),
+			byte(RandIntRange(1, 256)),
+		)
+	default:
+		return net.IPv4(
+			192,
+			168,
+			byte(RandIntRange(1, 256)),
+			byte(RandIntRange(1, 256)),
+		)
+	}
+}
+
+// RandomIPv4Loopback generates IPv4 Loopback address
+func RandIPv4Loopback() net.IP {
+	return net.IPv4(
+		127,
+		byte(RandIntRange(1, 256)),
+		byte(RandIntRange(1, 256)),
+		byte(RandIntRange(1, 256)),
+	)
+}
+
 // RandIPv6 generates a random IPv6 address.
 func RandIPv6() net.IP {
 	ip := make(net.IP, net.IPv6len)

random/random_test.go

@@ -192,3 +192,43 @@ func TestRandIPv6(t *testing.T) {
 		}
 	}
 }
+
+func TestRandIPv4Private(t *testing.T) {
+	for range 100 {
+		r := RandIPv4Private()
+		parsed := net.ParseIP(r.String())
+		if parsed == nil {
+			t.Error("Generated IP is nil: " + r.String())
+		}
+		if parsed.To4() == nil {
+			t.Error("Generated IP is not a valid IPv4 address: " + r.String())
+		}
+
+		// Check if the IP is private
+		isPrivate := r.IsPrivate()
+
+		if !isPrivate {
+			t.Error("Generated IP is not in a private range: " + r.String())
+		}
+	}
+}
+
+func TestRandIPv4Loopback(t *testing.T) {
+	for range 5 {
+		r := RandIPv4Loopback()
+		parsed := net.ParseIP(r.String())
+		if parsed == nil {
+			t.Error("Generated IP is nil: " + r.String())
+		}
+		if parsed.To4() == nil {
+			t.Error("Generated IP is not a valid IPv4 address: " + r.String())
+		}
+
+		// Check if the IP is loopback
+		isLoopback := r.IsLoopback()
+
+		if !isLoopback {
+			t.Error("Generated IP is not the expected loopback address:" + r.String())
+		}
+	}
+}