zones: allow iterators to terminate

Signed-off-by: Alejandro Mery <amery@jpi.io>

pkg/wireguard/config.go

@@ -1,7 +1,6 @@
 package wireguard
 
 import (
-	"encoding/base64"
 	"errors"
 	"fmt"
 	"io"
@@ -32,13 +31,13 @@ func (f *Config) Peers() int {
 // InterfaceConfig represents the [Interface] section
 type InterfaceConfig struct {
 	Address    netip.Addr
-	PrivateKey []byte
+	PrivateKey BinaryKey
 	ListenPort uint16
 }
 
 // PeerConfig represents a [Peer] section
 type PeerConfig struct {
-	PublicKey  []byte
+	PublicKey  BinaryKey
 	Endpoint   EndpointAddress
 	AllowedIPs []netip.Prefix
 }
@@ -129,19 +128,19 @@ type interfaceConfig struct {
 }
 
 func (p interfaceConfig) Export() (InterfaceConfig, error) {
+	var err error
+
 	out := InterfaceConfig{
 		Address:    p.Address,
 		ListenPort: p.ListenPort,
 	}
 
-	b, err := base64.StdEncoding.DecodeString(p.PrivateKey)
+	out.PrivateKey, err = BinaryKeyFromBase64(p.PrivateKey)
 	if err != nil {
 		err = core.Wrap(err, "PrivateKey")
 		return InterfaceConfig{}, err
 	}
 
-	out.PrivateKey = b
-
 	return out, nil
 }
 
@@ -163,8 +162,7 @@ func (v *intermediateConfig) ExportPeer(i int) (PeerConfig, error) {
 	}
 
 	// PublicKey
-	s = v.Peer.PublicKey[i]
-	out.PublicKey, err = base64.StdEncoding.DecodeString(s)
+	out.PublicKey, err = BinaryKeyFromBase64(v.Peer.PublicKey[i])
 	if err != nil {
 		err = core.Wrap(err, "PublicKey")
 		return out, err

pkg/wireguard/keys.go

@@ -0,0 +1,36 @@
+package wireguard
+
+import (
+	"bytes"
+	"encoding/base64"
+)
+
+// BinaryKey is a binary blob
+type BinaryKey []byte
+
+func (k BinaryKey) String() string {
+	return base64.StdEncoding.EncodeToString(k)
+}
+
+// IsZero tells if the key hasn't been set
+func (k BinaryKey) IsZero() bool {
+	return len(k) == 0
+}
+
+// Equal checks if two keys are identical
+func (k BinaryKey) Equal(alter BinaryKey) bool {
+	return bytes.Equal(k, alter)
+}
+
+// BinaryKeyFromBase64 decodes a base64-based string into
+// a [BinaryKey]
+func BinaryKeyFromBase64(data string) (BinaryKey, error) {
+	b, err := base64.StdEncoding.DecodeString(data)
+	return BinaryKey(b), err
+}
+
+// KeyPair holds a Key pair
+type KeyPair struct {
+	PrivateKey BinaryKey
+	PublicKey  BinaryKey
+}

pkg/zones/address.go

@@ -1,49 +0,0 @@
-package zones
-
-import "net/netip"
-
-// ParseRingZeroAddress extracts zone and node ID from a wg0 [netip.Addr]
-func ParseRingZeroAddress(addr netip.Addr) (zoneID int, nodeID int, ok bool) {
-	if addr.IsValid() {
-		a4 := addr.As4()
-
-		if a4[0] == 10 && a4[1] == 0 {
-			return int(a4[2]), int(a4[3]), true
-		}
-	}
-	return 0, 0, false
-}
-
-// RingZeroAddress returns a wg0 IP address
-func RingZeroAddress(zoneID, nodeID int) netip.Addr {
-	c := zoneID
-	d := nodeID
-
-	return netip.AddrFrom4([4]byte{
-		10, 0, uint8(c), uint8(d),
-	})
-}
-
-// ParseRingOneAddress extracts zone and node ID from a wg1 [netip.Addr]
-func ParseRingOneAddress(addr netip.Addr) (zoneID int, nodeID int, ok bool) {
-	if addr.IsValid() {
-		a4 := addr.As4()
-
-		if a4[0] == 10 && a4[2] == 0 {
-			zoneID = int(a4[1] >> 4)
-			nodeID = int(a4[3])
-			return zoneID, nodeID, true
-		}
-	}
-	return 0, 0, false
-}
-
-// RingOneAddress returns a wg1 IP address
-func RingOneAddress(zoneID, nodeID int) netip.Addr {
-	b := zoneID << 4
-	d := nodeID
-
-	return netip.AddrFrom4([4]byte{
-		10, uint8(b), 0, uint8(d),
-	})
-}

pkg/zones/machine.go

@@ -16,9 +16,10 @@ type Machine struct {
 
 	zone *Zone
 	id   int
-	Name string
+	Name string `toml:"name"`
 
-	PublicAddresses []netip.Addr
+	PublicAddresses []netip.Addr `toml:"public,omitempty"`
+	RingAddresses   []*RingInfo  `toml:"rings,omitempty"`
 }
 
 func (m *Machine) String() string {

pkg/zones/machine_rings.go

@@ -0,0 +1,66 @@
+package zones
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+
+	"darvaza.org/core"
+
+	"git.jpi.io/amery/jpictl/pkg/wireguard"
+)
+
+// GetWireguardConfig reads a wgN.conf file
+func (m *Machine) GetWireguardConfig(ring int) (*wireguard.Config, error) {
+	data, err := m.ReadFile("wg%v.conf", ring)
+	if err != nil {
+		return nil, err
+	}
+
+	r := bytes.NewReader(data)
+	return wireguard.NewConfigFromReader(r)
+}
+
+func (m *Machine) tryApplyWireguardConfig(ring int) error {
+	wg, err := m.GetWireguardConfig(ring)
+	switch {
+	case os.IsNotExist(err):
+		return nil
+	case err != nil:
+		return err
+	default:
+		return m.applyWireguardConfig(ring, wg)
+	}
+}
+
+func (m *Machine) applyWireguardConfig(ring int, wg *wireguard.Config) error {
+	addr := wg.GetAddress()
+	zoneID, nodeID, ok := Rings[ring].Decode(addr)
+	if !ok {
+		return fmt.Errorf("%s: invalid wg%v address: %s", m.Name, ring, addr)
+	}
+
+	if err := m.applyZoneNodeID(zoneID, nodeID); err != nil {
+		err = core.Wrapf(err, "%s: wg%v:%s", m.Name, ring, addr)
+		return err
+	}
+
+	return nil
+}
+
+func (m *Machine) applyZoneNodeID(zoneID, nodeID int) error {
+	switch {
+	case zoneID == 0:
+		return fmt.Errorf("invalid %s", "zoneID")
+	case nodeID == 0:
+		return fmt.Errorf("invalid %s", "nodeID")
+	case m.ID() != nodeID:
+		return fmt.Errorf("invalid %s: %v ≠ %v", "zoneID", m.ID(), nodeID)
+	case m.zone.ID != 0 && m.zone.ID != zoneID:
+		return fmt.Errorf("invalid %s: %v ≠ %v", "zoneID", m.zone.ID, zoneID)
+	case m.zone.ID == 0:
+		m.zone.ID = zoneID
+	}
+
+	return nil
+}

pkg/zones/machine_scan.go

@@ -26,5 +26,11 @@ func (m *Machine) updatePublicAddresses() error {
 }
 
 func (m *Machine) scan() error {
+	for i := 0; i < RingsCount; i++ {
+		if err := m.tryApplyWireguardConfig(i); err != nil {
+			return err
+		}
+	}
+
 	return m.updatePublicAddresses()
 }

pkg/zones/rings.go

@@ -0,0 +1,127 @@
+package zones
+
+import (
+	"net/netip"
+
+	"git.jpi.io/amery/jpictl/pkg/wireguard"
+)
+
+const (
+	// MaxZoneID indicates the highest ID allowed for a Zone
+	MaxZoneID = 0xf
+	// MaxNodeID indicates the highest Machine ID allowed within a Zone
+	MaxNodeID = 0xff - 1
+	// RingsCount indicates how many wireguard rings we have
+	RingsCount = 2
+)
+
+// RingInfo contains represents the Wireguard endpoint details
+// for a Machine on a particular ring
+type RingInfo struct {
+	Ring    int                `toml:"ring"`
+	Enabled bool               `toml:"enabled,omitempty"`
+	Keys    *wireguard.KeyPair `toml:"keys,omitempty"`
+	Address netip.Addr         `toml:"address,omitempty"`
+}
+
+// RingAddressEncoder provides encoder/decoder access for a particular
+// Wireguard ring
+type RingAddressEncoder struct {
+	ID     int
+	Encode func(zoneID, nodeID int) (netip.Addr, bool)
+	Decode func(addr netip.Addr) (zoneID, nodeID int, ok bool)
+}
+
+var (
+	// RingZero is a wg0 address encoder/decoder
+	RingZero = RingAddressEncoder{
+		ID:     0,
+		Decode: ParseRingZeroAddress,
+		Encode: RingZeroAddress,
+	}
+	// RingOne is a wg1 address encoder/decoder
+	RingOne = RingAddressEncoder{
+		ID:     1,
+		Decode: ParseRingOneAddress,
+		Encode: RingOneAddress,
+	}
+	// Rings provides indexed access to the ring address encoders
+	Rings = [RingsCount]RingAddressEncoder{
+		RingZero,
+		RingOne,
+	}
+)
+
+// ValidZoneID checks if the given zoneID is a valid 4 bit zone number.
+//
+// 0 is reserved, and only allowed when composing CIDRs.
+func ValidZoneID(zoneID int) bool {
+	switch {
+	case zoneID < 0 || zoneID > MaxZoneID:
+		return false
+	default:
+		return true
+	}
+}
+
+// ValidNodeID checks if the given nodeID is a valid 8 bit number.
+// nodeID is unique within a Zone.
+// 0 is reserved, and only allowed when composing CIDRs.
+func ValidNodeID(nodeID int) bool {
+	switch {
+	case nodeID < 0 || nodeID > MaxNodeID:
+		return false
+	default:
+		return true
+	}
+}
+
+// ParseRingZeroAddress extracts zone and node ID from a wg0 [netip.Addr]
+// wg0 addresses are of the form `10.0.{{zoneID}}.{{nodeID}}`
+func ParseRingZeroAddress(addr netip.Addr) (zoneID int, nodeID int, ok bool) {
+	if addr.IsValid() {
+		a4 := addr.As4()
+
+		if a4[0] == 10 && a4[1] == 0 {
+			return int(a4[2]), int(a4[3]), true
+		}
+	}
+	return 0, 0, false
+}
+
+// RingZeroAddress returns a wg0 IP address
+func RingZeroAddress(zoneID, nodeID int) (netip.Addr, bool) {
+	switch {
+	case !ValidZoneID(zoneID) || !ValidNodeID(nodeID):
+		return netip.Addr{}, false
+	default:
+		a4 := [4]uint8{10, 0, uint8(zoneID), uint8(nodeID)}
+		return netip.AddrFrom4(a4), true
+	}
+}
+
+// ParseRingOneAddress extracts zone and node ID from a wg1 [netip.Addr]
+// wg1 addresses are of the form `10.{{zoneID << 4}}.{{nodeID}}`
+func ParseRingOneAddress(addr netip.Addr) (zoneID int, nodeID int, ok bool) {
+	if addr.IsValid() {
+		a4 := addr.As4()
+
+		if a4[0] == 10 && a4[2] == 0 {
+			zoneID = int(a4[1] >> 4)
+			nodeID = int(a4[3])
+			return zoneID, nodeID, true
+		}
+	}
+	return 0, 0, false
+}
+
+// RingOneAddress returns a wg1 IP address
+func RingOneAddress(zoneID, nodeID int) (netip.Addr, bool) {
+	switch {
+	case !ValidZoneID(zoneID) || !ValidNodeID(nodeID):
+		return netip.Addr{}, false
+	default:
+		a4 := [4]uint8{10, 0, uint8(zoneID << 4), uint8(nodeID)}
+		return netip.AddrFrom4(a4), true
+	}
+}

pkg/zones/scan.go

@@ -31,10 +31,9 @@ func (m *Zones) scan() error {
 
 func (m *Zones) scanMachines() error {
 	var err error
-	m.ForEachMachine(func(p *Machine) {
-		if err == nil {
-			err = p.scan()
-		}
+	m.ForEachMachine(func(p *Machine) bool {
+		err = p.scan()
+		return err != nil
 	})
 	return err
 }

pkg/zones/zones.go

@@ -32,26 +32,34 @@ type Zones struct {
 }
 
 // ForEachMachine calls a function for each Machine in the cluster
-func (m *Zones) ForEachMachine(fn func(*Machine)) {
+func (m *Zones) ForEachMachine(fn func(*Machine) bool) {
 	for _, z := range m.Zones {
 		for _, p := range z.Machines {
-			fn(p)
+			if fn(p) {
+				// terminate
+				return
+			}
 		}
 	}
 }
 
 // ForEachZone calls a function for each Zone in the cluster
-func (m *Zones) ForEachZone(fn func(*Zone)) {
+func (m *Zones) ForEachZone(fn func(*Zone) bool) {
 	for _, p := range m.Zones {
-		fn(p)
+		if fn(p) {
+			// terminate
+			return
+		}
 	}
 }
 
 // NewFS builds a [Zones] tree using the given directory
 func NewFS(dir fs.FS, domain string) (*Zones, error) {
+	lockuper := resolver.NewCloudflareLookuper()
+
 	z := &Zones{
 		dir:      dir,
-		resolver: resolver.SystemResolver(true),
+		resolver: resolver.NewResolver(lockuper),
 		domain:   domain,
 	}