fix: exclude zero address as for inadmissable cases (#650)

* fix: exclude zero address as for inadmissable cases

* fix: review finding

stackit/internal/services/iaas/network/resource.go

@@ -200,7 +200,7 @@ func (r *networkResource) Schema(_ context.Context, _ resource.SchemaRequest, re
 				Optional:    true,
 				Computed:    true,
 				Validators: []validator.String{
-					validate.IP(),
+					validate.IP(false),
 				},
 			},
 			"ipv4_nameservers": schema.ListAttribute{
@@ -252,7 +252,7 @@ func (r *networkResource) Schema(_ context.Context, _ resource.SchemaRequest, re
 				Optional:    true,
 				Computed:    true,
 				Validators: []validator.String{
-					validate.IP(),
+					validate.IP(false),
 				},
 			},
 			"ipv6_nameservers": schema.ListAttribute{

stackit/internal/services/iaas/networkarearoute/resource.go

@@ -161,7 +161,7 @@ func (r *networkAreaRouteResource) Schema(_ context.Context, _ resource.SchemaRe
 					stringplanmodifier.RequiresReplace(),
 				},
 				Validators: []validator.String{
-					validate.IP(),
+					validate.IP(false),
 				},
 			},
 			"prefix": schema.StringAttribute{

stackit/internal/services/iaas/networkinterface/resource.go

@@ -200,7 +200,7 @@ func (r *networkInterfaceResource) Schema(_ context.Context, _ resource.SchemaRe
 				Optional:    true,
 				Computed:    true,
 				Validators: []validator.String{
-					validate.IP(),
+					validate.IP(false),
 				},
 				PlanModifiers: []planmodifier.String{
 					stringplanmodifier.RequiresReplace(),

stackit/internal/services/iaas/publicip/resource.go

@@ -147,7 +147,7 @@ func (r *publicIpResource) Schema(_ context.Context, _ resource.SchemaRequest, r
 					stringplanmodifier.UseStateForUnknown(),
 				},
 				Validators: []validator.String{
-					validate.IP(),
+					validate.IP(false),
 				},
 			},
 			"network_interface_id": schema.StringAttribute{

stackit/internal/services/iaas/publicipassociate/resource.go

@@ -155,7 +155,7 @@ func (r *publicIpAssociateResource) Schema(_ context.Context, _ resource.SchemaR
 					stringplanmodifier.UseStateForUnknown(),
 				},
 				Validators: []validator.String{
-					validate.IP(),
+					validate.IP(false),
 				},
 			},
 			"network_interface_id": schema.StringAttribute{

stackit/internal/validate/validate.go

@@ -67,13 +67,17 @@ func UUID() *Validator {
 	}
 }
 
-func IP() *Validator {
+// IP returns a validator that checks, if the given string is a valid IP address.
+// The allowZeroAddress parameter defines, if 0.0.0.0, resp. [::] should be considered valid.
+func IP(allowZeroAddress bool) *Validator {
 	description := "value must be an IP address"
 
 	return &Validator{
 		description: description,
 		validate: func(_ context.Context, req validator.StringRequest, resp *validator.StringResponse) {
-			if net.ParseIP(req.ConfigValue.ValueString()) == nil {
+			ip := net.ParseIP(req.ConfigValue.ValueString())
+			invalidZeroAddress := !allowZeroAddress && (net.IPv4zero.Equal(ip) || net.IPv6zero.Equal(ip))
+			if ip == nil || invalidZeroAddress {
 				resp.Diagnostics.Append(validatordiag.InvalidAttributeValueDiagnostic(
 					req.Path,
 					description,

stackit/internal/validate/validate_test.go

@@ -58,39 +58,87 @@ func TestUUID(t *testing.T) {
 func TestIP(t *testing.T) {
 	tests := []struct {
 		description string
+		invalidZero bool
 		input       string
 		isValid     bool
 	}{
 		{
 			"ok IP4",
+			false,
 			"111.222.111.222",
 			true,
 		},
 		{
 			"ok IP6",
+			false,
 			"2001:0db8:85a3:08d3::0370:7344",
 			true,
 		},
 		{
 			"too short",
+			false,
 			"0.1.2",
 			false,
 		},
 		{
 			"Empty",
+			false,
 			"",
 			false,
 		},
 		{
 			"Not an IP",
+			false,
 			"for-sure-not-an-IP",
 			false,
 		},
+		{
+			"valid ipv4 zero",
+			true,
+			"0.0.0.0",
+			true,
+		},
+		{
+			"invalid ipv4 zero",
+			false,
+			"0.0.0.0",
+			false,
+		},
+		{
+			"valid ipv6 zero",
+			true,
+			"::",
+			true,
+		},
+		{
+			"valid ipv6 zero short notation",
+			true,
+			"::0",
+			true,
+		},
+		{
+			"valid ipv6 zero long notation",
+			true,
+			"0000:0000:0000:0000:0000:0000:0000:0000",
+			true,
+		},
+		{
+			"invalid ipv6 zero short notation",
+			false,
+			"::",
+			false,
+		},
+		{
+			"invalid ipv6 zero long notation",
+			false,
+			"0000:0000:0000:0000:0000:0000:0000:0000",
+			false,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.description, func(t *testing.T) {
 			r := validator.StringResponse{}
-			IP().ValidateString(context.Background(), validator.StringRequest{
+			IP(tt.invalidZero).ValidateString(context.Background(), validator.StringRequest{
 				ConfigValue: types.StringValue(tt.input),
 			}, &r)