Allow managing IPv6 network settings

ZeroTier has a couple of settings related to IPv6 address assignment
options which distribute IPv6 addresses computed based on the network id
and the node id.

RFC4139 assigns an single IPv6 address for each of the nodes.

6PLANE assigns a whole /80 prefix for each node, which could be
redistributed by the member, such as a router or used for Docker
containers.

Both of them are deterministic values calculated based on the network id
and node id, and they are not returned on the response of the
controller, given that the client is capable of calculating it itself.

IPv6 Assignment distribute IPv6 from the the assignment pool for each
member. If there is no IPv6 assignment pool configured, no route will be
distributed. It is important to also include the route configuration for
that network, so there is traffic through ZeroTier.

This commit exposes this information on the member resource, as a
computed property, so we could reference this information on other
Terraform resources (such as DNS settings or provisioner scripts).

Given this is a calculated property that is always present, downstream
modules should check if the network has it configured before using it.
No errors will be thrown, it would only not route properly if the
network has not enabled it.

The commit also exposes the settings in the network to enable each of
the IPv6 address distribution toggles on the network resource.

There is also a bug fix, where the IPv4 configuration toggle was
hardcoded and not reading the value from the resource definition.

README.md

@@ -114,6 +114,53 @@ resource "zerotier_network" "your_network" {
 If you don't specify either an assignment pool or a managed route, while it's
 perfectly valid, your network won't be very useful, so try to do both.
 
+Full list of properties:
+
+```hcl
+resource "zerotier_network" "your_network" {
+    name = "your_network_name"
+
+    # Optional values
+    # description = "Managed by Terraform"
+    # rules_source = "Default rule pulled from ZeroTier"
+
+    # private = true
+
+    # Assign IPv4 addresses from the assignment_pool
+    # auto_assign_v4 = true
+
+    # Effectively assign IPv6 RFC4193 (/128) for members of the network
+    # auto_assign_rfc4193 = true
+
+    # Effectively assign IPv6 RFC4193 (/128) for members of the network
+    # auto_assign_6plane = false
+
+    # Assing IPv6 addresses from the assignment_pool
+    # auto_assign_v6 = false
+
+    # Multiple assignment pools allowed
+    # assignment_pool {
+    #     cidr = "IPv4 or IPv6 CIDR notation"
+    # }
+    # assignment_pool {
+    #     first  = "IPv4 or IPv6 address" # eg 10.96.0.2
+    #     last   = "IPv4 or IPv6 address" # eg 10.96.0.254
+    # }
+
+    # Multiple routes configuration allowed
+    # route {
+    #     target = "${var.zt_cidr}"
+    # }
+    # route {
+    #     target = "${var.other_network}"
+    #     via    = "${local.gateway_ip}"
+    # }
+
+    # Computed
+    # id: Network ID
+}
+```
+
 #### Multiple routes
 
 You can have more than one assignment pool, and more than one route. Multiple
@@ -251,6 +298,16 @@ resource "zerotier_member" "hector" {
   # see ZeroTier Manual section on L2/ethernet bridging
   allow_ethernet_bridging = true
 
+  # Computed properties available to interpolate
+
+  # rfc4193_address
+  # Computed RFC4193 (IPv6 /128) address based on the network and node id
+  # Always calculated, and determined if they are used by the network resource
+
+  # 6plane_address
+  # Computed 6PLANE (IPv6 /80) address based on the network and node id
+  # Always calculated, and determined if they are used by the network resource
+
 }
 ```
 

zerotier/client.go

@@ -31,12 +31,19 @@ type V4AssignModeConfig struct {
 	ZT bool `json:"zt"`
 }
 
+type V6AssignModeConfig struct {
+	ZT       bool `json:"zt"`
+	SixPLANE bool `json:"6plane"`
+	RFC4193  bool `json:"rfc4193"`
+}
+
 type Config struct {
 	Name              string             `json:"name"`
 	Private           bool               `json:"private"`
 	Routes            []Route            `json:"routes"`
 	IpAssignmentPools []IpRange          `json:"ipAssignmentPools"`
 	V4AssignMode      V4AssignModeConfig `json:"v4AssignMode"`
+	V6AssignMode      V6AssignModeConfig `json:"v6AssignMode"`
 }
 
 type ConfigReadOnly struct {

zerotier/resource_zerotier_member.go

@@ -65,12 +65,23 @@ func resourceZeroTierMember() *schema.Resource {
 				Default:  false,
 			},
 			"ip_assignments": {
-				Type:     schema.TypeList,
-				Optional: true,
+				Type:        schema.TypeSet,
+				Description: "List of IP routed and assigned byt ZeroTier controller assignment pool. Does not include RFC4193 nor 6PLANE addresses, only those from assignment pool or manually provided.",
+				Optional:    true,
 				Elem: &schema.Schema{
 					Type: schema.TypeString,
 				},
 			},
+			"rfc4193_address": {
+				Type:        schema.TypeString,
+				Description: "Computed RFC4193 (IPv6 /128) address. Always calculated and only actually assigned on the member if RFC4193 is configured on the network.",
+				Computed:    true,
+			},
+			"6plane_address": {
+				Type:        schema.TypeString,
+				Description: "Computed 6PLANE (IPv6 /60) address. Always calculated and only actually assigned on the member if 6PLANE is configured on the network.",
+				Computed:    true,
+			},
 			"capabilities": {
 				Type:     schema.TypeList,
 				Optional: true,
@@ -152,7 +163,7 @@ func memberFromResourceData(d *schema.ResourceData) (*Member, error) {
 	for i := range capsRaw {
 		caps[i] = capsRaw[i].(int)
 	}
-	ipsRaw := d.Get("ip_assignments").([]interface{})
+	ipsRaw := d.Get("ip_assignments").(*schema.Set).List()
 	ips := make([]string, len(ipsRaw))
 	for i := range ipsRaw {
 		ips[i] = ipsRaw[i].(string)
@@ -193,6 +204,33 @@ func resourceNetworkAndNodeIdentifiers(d *schema.ResourceData) (string, string)
 	return nwid, nodeID
 }
 
+// Receive a string and format every 4th element with a ":"
+func buildIPV6(data string) (result string) {
+	s := strings.SplitAfter(data, "")
+	end := len(s) - 1
+	result = ""
+	for i, s := range s {
+		result += s
+		if (i+1)%4 == 0 && i != end {
+			result += ":"
+		}
+	}
+	return
+}
+
+func sixPlaneAddress(d *schema.ResourceData) string {
+	nwid, nodeID := resourceNetworkAndNodeIdentifiers(d)
+	return buildIPV6("fd" + nwid + "9993" + nodeID)
+}
+
+func rfc4193Address(d *schema.ResourceData) string {
+	nwid, nodeID := resourceNetworkAndNodeIdentifiers(d)
+	nwidInt, _ := strconv.ParseUint(nwid, 16, 64)
+	networkMask := uint32((nwidInt >> 32) ^ nwidInt)
+	networkPrefix := strconv.FormatUint(uint64(networkMask), 16)
+	return buildIPV6("fc" + networkPrefix + nodeID + "000000000001")
+}
+
 func resourceMemberRead(d *schema.ResourceData, m interface{}) error {
 	client := m.(*ZeroTierClient)
 
@@ -221,6 +259,8 @@ func resourceMemberRead(d *schema.ResourceData, m interface{}) error {
 	d.Set("allow_ethernet_bridging", member.Config.ActiveBridge)
 	d.Set("no_auto_assign_ips", member.Config.NoAutoAssignIps)
 	d.Set("ip_assignments", member.Config.IpAssignments)
+	d.Set("rfc4193_address", rfc4193Address(d))
+	d.Set("6plane_address", sixPlaneAddress(d))
 	d.Set("capabilities", member.Config.Capabilities)
 	setTags(d, member)
 

zerotier/resource_zerotier_network.go

@@ -65,6 +65,24 @@ func resourceZeroTierNetwork() *schema.Resource {
 				Optional: true,
 				Default:  true,
 			},
+			"auto_assign_v6": &schema.Schema{
+				Type:        schema.TypeBool,
+				Description: "Auto assign IPv6 to members from ZeroTier assignment pool",
+				Optional:    true,
+				Default:     false,
+			},
+			"auto_assign_6plane": &schema.Schema{
+				Type:        schema.TypeBool,
+				Description: "Auto assign IPv6 /60 to members using 6PLANE adressing",
+				Optional:    true,
+				Default:     false,
+			},
+			"auto_assign_rfc4193": &schema.Schema{
+				Type:        schema.TypeBool,
+				Description: "Auto assign IPv6 /128 to members using RFC4193 adressing",
+				Optional:    true,
+				Default:     true,
+			},
 			"route": &schema.Schema{
 				Type:     schema.TypeList,
 				Optional: true,
@@ -145,9 +163,16 @@ func fromResourceData(d *schema.ResourceData) (*Network, error) {
 		RulesSource: d.Get("rules_source").(string),
 		Description: d.Get("description").(string),
 		Config: &Config{
-			Name:              d.Get("name").(string),
-			Private:           d.Get("private").(bool),
-			V4AssignMode:      V4AssignModeConfig{ZT: true},
+			Name:    d.Get("name").(string),
+			Private: d.Get("private").(bool),
+			V4AssignMode: V4AssignModeConfig{
+				ZT: d.Get("auto_assign_v4").(bool),
+			},
+			V6AssignMode: V6AssignModeConfig{
+				ZT:       d.Get("auto_assign_v6").(bool),
+				SixPLANE: d.Get("auto_assign_6plane").(bool),
+				RFC4193:  d.Get("auto_assign_rfc4193").(bool),
+			},
 			Routes:            routes,
 			IpAssignmentPools: pools,
 		},
@@ -190,6 +215,9 @@ func resourceNetworkRead(d *schema.ResourceData, m interface{}) error {
 	d.Set("description", net.Description)
 	d.Set("private", net.Config.Private)
 	d.Set("auto_assign_v4", net.Config.V4AssignMode.ZT)
+	d.Set("auto_assign_v6", net.Config.V6AssignMode.ZT)
+	d.Set("auto_assign_6plane", net.Config.V6AssignMode.SixPLANE)
+	d.Set("auto_assign_rfc4193", net.Config.V6AssignMode.RFC4193)
 	d.Set("rules_source", net.RulesSource)
 
 	setRoutes(d, net)