Merge 2e68455331 into a71a933705

hscontrol/app.go

@@ -30,6 +30,7 @@ import (
 	"github.com/juanfont/headscale/hscontrol/mapper"
 	"github.com/juanfont/headscale/hscontrol/notifier"
 	"github.com/juanfont/headscale/hscontrol/policy"
+	"github.com/juanfont/headscale/hscontrol/policyv2"
 	"github.com/juanfont/headscale/hscontrol/types"
 	"github.com/juanfont/headscale/hscontrol/util"
 	zerolog "github.com/philip-bui/grpc-zerolog"
@@ -89,6 +90,7 @@ type Headscale struct {
 	DERPServer *derpServer.DERPServer
 
 	ACLPolicy     *policy.ACLPolicy
+	PolicyManager *policyv2.PolicyManager
 
 	mapper       *mapper.Mapper
 	nodeNotifier *notifier.Notifier

hscontrol/policy/acls_test.go

@@ -1764,9 +1764,9 @@ var tsExitNodeDest = []tailcfg.NetPortRange{
 	},
 }
 
-// hsExitNodeDest is the list of destination IP ranges that are allowed when
+// hsExitNodeDestForTest is the list of destination IP ranges that are allowed when
 // we use headscale "autogroup:internet".
-var hsExitNodeDest = []tailcfg.NetPortRange{
+var hsExitNodeDestForTest = []tailcfg.NetPortRange{
 	{IP: "0.0.0.0/5", Ports: tailcfg.PortRangeAny},
 	{IP: "8.0.0.0/7", Ports: tailcfg.PortRangeAny},
 	{IP: "11.0.0.0/8", Ports: tailcfg.PortRangeAny},
@@ -1823,13 +1823,13 @@ func TestTheInternet(t *testing.T) {
 	internetPrefs := internetSet.Prefixes()
 
 	for i := range internetPrefs {
-		if internetPrefs[i].String() != hsExitNodeDest[i].IP {
+		if internetPrefs[i].String() != hsExitNodeDestForTest[i].IP {
-			t.Errorf("prefix from internet set %q != hsExit list %q", internetPrefs[i].String(), hsExitNodeDest[i].IP)
+			t.Errorf("prefix from internet set %q != hsExit list %q", internetPrefs[i].String(), hsExitNodeDestForTest[i].IP)
 		}
 	}
 
-	if len(internetPrefs) != len(hsExitNodeDest) {
+	if len(internetPrefs) != len(hsExitNodeDestForTest) {
-		t.Fatalf("expected same length of prefixes, internet: %d, hsExit: %d", len(internetPrefs), len(hsExitNodeDest))
+		t.Fatalf("expected same length of prefixes, internet: %d, hsExit: %d", len(internetPrefs), len(hsExitNodeDestForTest))
 	}
 }
 
@@ -1838,20 +1838,27 @@ func TestReduceFilterRules(t *testing.T) {
 		name  string
 		node  *types.Node
 		peers types.Nodes
-		pol   ACLPolicy
+		pol   string
 		want  []tailcfg.FilterRule
 	}{
 		{
 			name: "host1-can-reach-host2-no-rules",
-			pol: ACLPolicy{
+			pol: `
-				ACLs: []ACL{
+{
+  "acls": [
     {
-						Action:       "accept",
+      "action": "accept",
-						Sources:      []string{"100.64.0.1"},
+      "proto": "",
-						Destinations: []string{"100.64.0.2:*"},
+      "src": [
-					},
+        "100.64.0.1"
-				},
+      ],
-			},
+      "dst": [
+        "100.64.0.2:*"
+      ]
+    }
+  ],
+}
+`,
 			node: &types.Node{
 				IPv4: iap("100.64.0.1"),
 				IPv6: iap("fd7a:115c:a1e0:ab12:4843:2222:6273:2221"),
@@ -1868,23 +1875,37 @@ func TestReduceFilterRules(t *testing.T) {
 		},
 		{
 			name: "1604-subnet-routers-are-preserved",
-			pol: ACLPolicy{
+			pol: `
-				Groups: Groups{
+{
-					"group:admins": {"user1"},
+  "groups": {
+    "group:admins": [
+      "user1"
+    ]
   },
-				ACLs: []ACL{
+  "acls": [
     {
-						Action:       "accept",
+      "action": "accept",
-						Sources:      []string{"group:admins"},
+      "proto": "",
-						Destinations: []string{"group:admins:*"},
+      "src": [
+        "group:admins"
+      ],
+      "dst": [
+        "group:admins:*"
+      ]
     },
     {
-						Action:       "accept",
+      "action": "accept",
-						Sources:      []string{"group:admins"},
+      "proto": "",
-						Destinations: []string{"10.33.0.0/16:*"},
+      "src": [
-					},
+        "group:admins"
-				},
+      ],
-			},
+      "dst": [
+        "10.33.0.0/16:*"
+      ]
+    }
+  ],
+}
+`,
 			node: &types.Node{
 				IPv4: iap("100.64.0.1"),
 				IPv6: iap("fd7a:115c:a1e0::1"),
@@ -1939,31 +1960,42 @@ func TestReduceFilterRules(t *testing.T) {
 		},
 		{
 			name: "1786-reducing-breaks-exit-nodes-the-client",
-			pol: ACLPolicy{
+			pol: `
-				Hosts: Hosts{
+{
-					// Exit node
+  "groups": {
-					"internal": netip.MustParsePrefix("100.64.0.100/32"),
+    "group:team": [
+      "user3",
+      "user2",
+      "user1"
+    ]
   },
-				Groups: Groups{
+  "hosts": {
-					"group:team": {"user3", "user2", "user1"},
+    "internal": "100.64.0.100/32"
   },
-				ACLs: []ACL{
+  "acls": [
     {
-						Action:  "accept",
+      "action": "accept",
-						Sources: []string{"group:team"},
+      "proto": "",
-						Destinations: []string{
+      "src": [
-							"internal:*",
+        "group:team"
-						},
+      ],
+      "dst": [
+        "internal:*"
+      ]
     },
     {
-						Action:  "accept",
+      "action": "accept",
-						Sources: []string{"group:team"},
+      "proto": "",
-						Destinations: []string{
+      "src": [
-							"autogroup:internet:*",
+        "group:team"
-						},
+      ],
-					},
+      "dst": [
-				},
+        "autogroup:internet:*"
-			},
+      ]
+    }
+  ],
+}
+`,
 			node: &types.Node{
 				IPv4: iap("100.64.0.1"),
 				IPv6: iap("fd7a:115c:a1e0::1"),
@@ -1989,31 +2021,42 @@ func TestReduceFilterRules(t *testing.T) {
 		},
 		{
 			name: "1786-reducing-breaks-exit-nodes-the-exit",
-			pol: ACLPolicy{
+			pol: `
-				Hosts: Hosts{
+{
-					// Exit node
+  "groups": {
-					"internal": netip.MustParsePrefix("100.64.0.100/32"),
+    "group:team": [
+      "user3",
+      "user2",
+      "user1"
+    ]
   },
-				Groups: Groups{
+  "hosts": {
-					"group:team": {"user3", "user2", "user1"},
+    "internal": "100.64.0.100/32"
   },
-				ACLs: []ACL{
+  "acls": [
     {
-						Action:  "accept",
+      "action": "accept",
-						Sources: []string{"group:team"},
+      "proto": "",
-						Destinations: []string{
+      "src": [
-							"internal:*",
+        "group:team"
-						},
+      ],
+      "dst": [
+        "internal:*"
+      ]
     },
     {
-						Action:  "accept",
+      "action": "accept",
-						Sources: []string{"group:team"},
+      "proto": "",
-						Destinations: []string{
+      "src": [
-							"autogroup:internet:*",
+        "group:team"
-						},
+      ],
-					},
+      "dst": [
-				},
+        "autogroup:internet:*"
-			},
+      ]
+    }
+  ],
+}
+`,
 			node: &types.Node{
 				IPv4: iap("100.64.0.100"),
 				IPv6: iap("fd7a:115c:a1e0::100"),
@@ -2050,32 +2093,42 @@ func TestReduceFilterRules(t *testing.T) {
 				},
 				{
 					SrcIPs:   []string{"100.64.0.1/32", "100.64.0.2/32", "fd7a:115c:a1e0::1/128", "fd7a:115c:a1e0::2/128"},
-					DstPorts: hsExitNodeDest,
+					DstPorts: hsExitNodeDestForTest,
 				},
 			},
 		},
 		{
 			name: "1786-reducing-breaks-exit-nodes-the-example-from-issue",
-			pol: ACLPolicy{
+			pol: `
-				Hosts: Hosts{
+{
-					// Exit node
+  "groups": {
-					"internal": netip.MustParsePrefix("100.64.0.100/32"),
+    "group:team": [
+      "user3",
+      "user2",
+      "user1"
+    ]
   },
-				Groups: Groups{
+  "hosts": {
-					"group:team": {"user3", "user2", "user1"},
+    "internal": "100.64.0.100/32"
   },
-				ACLs: []ACL{
+  "acls": [
     {
-						Action:  "accept",
+      "action": "accept",
-						Sources: []string{"group:team"},
+      "proto": "",
-						Destinations: []string{
+      "src": [
-							"internal:*",
+        "group:team"
-						},
+      ],
+      "dst": [
+        "internal:*"
+      ]
     },
     {
-						Action:  "accept",
+      "action": "accept",
-						Sources: []string{"group:team"},
+      "proto": "",
-						Destinations: []string{
+      "src": [
+        "group:team"
+      ],
+      "dst": [
         "0.0.0.0/5:*",
         "8.0.0.0/7:*",
         "11.0.0.0/8:*",
@@ -2105,11 +2158,12 @@ func TestReduceFilterRules(t *testing.T) {
         "194.0.0.0/7:*",
         "196.0.0.0/6:*",
         "200.0.0.0/5:*",
-							"208.0.0.0/4:*",
+        "208.0.0.0/4:*"
-						},
+      ]
-					},
+    }
-				},
+  ],
-			},
+}
+`,
 			node: &types.Node{
 				IPv4: iap("100.64.0.100"),
 				IPv6: iap("fd7a:115c:a1e0::100"),
@@ -2186,32 +2240,43 @@ func TestReduceFilterRules(t *testing.T) {
 		},
 		{
 			name: "1786-reducing-breaks-exit-nodes-app-connector-like",
-			pol: ACLPolicy{
+			pol: `
-				Hosts: Hosts{
+{
-					// Exit node
+  "groups": {
-					"internal": netip.MustParsePrefix("100.64.0.100/32"),
+    "group:team": [
+      "user3",
+      "user2",
+      "user1"
+    ]
   },
-				Groups: Groups{
+  "hosts": {
-					"group:team": {"user3", "user2", "user1"},
+    "internal": "100.64.0.100/32"
   },
-				ACLs: []ACL{
+  "acls": [
     {
-						Action:  "accept",
+      "action": "accept",
-						Sources: []string{"group:team"},
+      "proto": "",
-						Destinations: []string{
+      "src": [
-							"internal:*",
+        "group:team"
-						},
+      ],
+      "dst": [
+        "internal:*"
+      ]
     },
     {
-						Action:  "accept",
+      "action": "accept",
-						Sources: []string{"group:team"},
+      "proto": "",
-						Destinations: []string{
+      "src": [
+        "group:team"
+      ],
+      "dst": [
         "8.0.0.0/8:*",
-							"16.0.0.0/8:*",
+        "16.0.0.0/8:*"
-						},
+      ]
-					},
+    }
-				},
+  ],
-			},
+}
+`,
 			node: &types.Node{
 				IPv4: iap("100.64.0.100"),
 				IPv6: iap("fd7a:115c:a1e0::100"),
@@ -2263,32 +2328,43 @@ func TestReduceFilterRules(t *testing.T) {
 		},
 		{
 			name: "1786-reducing-breaks-exit-nodes-app-connector-like2",
-			pol: ACLPolicy{
+			pol: `
-				Hosts: Hosts{
+{
-					// Exit node
+  "groups": {
-					"internal": netip.MustParsePrefix("100.64.0.100/32"),
+    "group:team": [
+      "user3",
+      "user2",
+      "user1"
+    ]
   },
-				Groups: Groups{
+  "hosts": {
-					"group:team": {"user3", "user2", "user1"},
+    "internal": "100.64.0.100/32"
   },
-				ACLs: []ACL{
+  "acls": [
     {
-						Action:  "accept",
+      "action": "accept",
-						Sources: []string{"group:team"},
+      "proto": "",
-						Destinations: []string{
+      "src": [
-							"internal:*",
+        "group:team"
-						},
+      ],
+      "dst": [
+        "internal:*"
+      ]
     },
     {
-						Action:  "accept",
+      "action": "accept",
-						Sources: []string{"group:team"},
+      "proto": "",
-						Destinations: []string{
+      "src": [
+        "group:team"
+      ],
+      "dst": [
         "8.0.0.0/16:*",
-							"16.0.0.0/16:*",
+        "16.0.0.0/16:*"
-						},
+      ]
-					},
+    }
-				},
+  ],
-			},
+}
+`,
 			node: &types.Node{
 				IPv4: iap("100.64.0.100"),
 				IPv6: iap("fd7a:115c:a1e0::100"),
@@ -2340,25 +2416,32 @@ func TestReduceFilterRules(t *testing.T) {
 		},
 		{
 			name: "1817-reduce-breaks-32-mask",
-			pol: ACLPolicy{
+			pol: `
-				Hosts: Hosts{
+{
-					"vlan1": netip.MustParsePrefix("172.16.0.0/24"),
+  "groups": {
-					"dns1":  netip.MustParsePrefix("172.16.0.21/32"),
+    "group:access": [
+      "user1"
+    ]
   },
-				Groups: Groups{
+  "hosts": {
-					"group:access": {"user1"},
+    "dns1": "172.16.0.21/32",
+    "vlan1": "172.16.0.0/24"
   },
-				ACLs: []ACL{
+  "acls": [
     {
-						Action:  "accept",
+      "action": "accept",
-						Sources: []string{"group:access"},
+      "proto": "",
-						Destinations: []string{
+      "src": [
+        "group:access"
+      ],
+      "dst": [
         "tag:access-servers:*",
-							"dns1:*",
+        "dns1:*"
-						},
+      ]
-					},
+    }
-				},
+  ],
-			},
+}
+`,
 			node: &types.Node{
 				IPv4: iap("100.64.0.100"),
 				IPv6: iap("fd7a:115c:a1e0::100"),
@@ -2399,7 +2482,11 @@ func TestReduceFilterRules(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got, _ := tt.pol.CompileFilterRules(
+			pol, err := LoadACLPolicyFromBytes([]byte(tt.pol))
+			if err != nil {
+				t.Fatalf("parsing policy: %s", err)
+			}
+			got, _ := pol.CompileFilterRules(
 				append(tt.peers, tt.node),
 			)
 

hscontrol/policyv2/filter.go

@@ -0,0 +1,180 @@
+package policyv2
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/juanfont/headscale/hscontrol/types"
+	"go4.org/netipx"
+	"tailscale.com/tailcfg"
+)
+
+var (
+	ErrInvalidAction = errors.New("invalid action")
+)
+
+// CompileFilterRules takes a set of nodes and an ACLPolicy and generates a
+// set of Tailscale compatible FilterRules used to allow traffic on clients.
+func (pol *Policy) CompileFilterRules(
+	users types.Users,
+	nodes types.Nodes,
+) ([]tailcfg.FilterRule, error) {
+	if pol == nil {
+		return tailcfg.FilterAllowAll, nil
+	}
+
+	var rules []tailcfg.FilterRule
+
+	for _, acl := range pol.ACLs {
+		if acl.Action != "accept" {
+			return nil, ErrInvalidAction
+		}
+
+		srcIPs, err := acl.Sources.Resolve(pol, users, nodes)
+		if err != nil {
+			return nil, fmt.Errorf("resolving source ips: %w", err)
+		}
+
+		// TODO(kradalby): integrate type into schema
+		// TODO(kradalby): figure out the _ is wildcard stuff
+		protocols, _, err := parseProtocol(acl.Protocol)
+		if err != nil {
+			return nil, fmt.Errorf("parsing policy, protocol err: %w ", err)
+		}
+
+		var destPorts []tailcfg.NetPortRange
+		for _, dest := range acl.Destinations {
+			ips, err := dest.Alias.Resolve(pol, users, nodes)
+			if err != nil {
+				return nil, err
+			}
+
+			for _, pref := range ips.Prefixes() {
+				for _, port := range dest.Ports {
+					pr := tailcfg.NetPortRange{
+						IP:    pref.String(),
+						Ports: port,
+					}
+					destPorts = append(destPorts, pr)
+				}
+			}
+		}
+
+		rules = append(rules, tailcfg.FilterRule{
+			SrcIPs:   ipSetToPrefixStringList(srcIPs),
+			DstPorts: destPorts,
+			IPProto:  protocols,
+		})
+	}
+
+	return rules, nil
+}
+
+func sshAction(accept bool, duration time.Duration) tailcfg.SSHAction {
+	return tailcfg.SSHAction{
+		Reject:                   !accept,
+		Accept:                   accept,
+		SessionDuration:          duration,
+		AllowAgentForwarding:     true,
+		AllowLocalPortForwarding: true,
+	}
+}
+
+func (pol *Policy) CompileSSHPolicy(
+	users types.Users,
+	node types.Node,
+	nodes types.Nodes,
+) (*tailcfg.SSHPolicy, error) {
+	if pol == nil {
+		return nil, nil
+	}
+
+	var rules []*tailcfg.SSHRule
+
+	for index, rule := range pol.SSHs {
+		var dest netipx.IPSetBuilder
+		for _, src := range rule.Destinations {
+			ips, err := src.Resolve(pol, users, nodes)
+			if err != nil {
+				return nil, err
+			}
+			dest.AddSet(ips)
+		}
+
+		destSet, err := dest.IPSet()
+		if err != nil {
+			return nil, err
+		}
+
+		if !node.InIPSet(destSet) {
+			continue
+		}
+
+		var action tailcfg.SSHAction
+		switch rule.Action {
+		case "accept":
+			action = sshAction(true, 0)
+		case "check":
+			action = sshAction(true, rule.CheckPeriod)
+		default:
+			return nil, fmt.Errorf("parsing SSH policy, unknown action %q, index: %d: %w", rule.Action, index, err)
+		}
+
+		var principals []*tailcfg.SSHPrincipal
+		for _, src := range rule.Sources {
+			if isWildcard(rawSrc) {
+				principals = append(principals, &tailcfg.SSHPrincipal{
+					Any: true,
+				})
+			} else if isGroup(rawSrc) {
+				users, err := pol.expandUsersFromGroup(rawSrc)
+				if err != nil {
+					return nil, fmt.Errorf("parsing SSH policy, expanding user from group, index: %d->%d: %w", index, innerIndex, err)
+				}
+
+				for _, user := range users {
+					principals = append(principals, &tailcfg.SSHPrincipal{
+						UserLogin: user,
+					})
+				}
+			} else {
+				expandedSrcs, err := pol.ExpandAlias(
+					peers,
+					rawSrc,
+				)
+				if err != nil {
+					return nil, fmt.Errorf("parsing SSH policy, expanding alias, index: %d->%d: %w", index, innerIndex, err)
+				}
+				for _, expandedSrc := range expandedSrcs.Prefixes() {
+					principals = append(principals, &tailcfg.SSHPrincipal{
+						NodeIP: expandedSrc.Addr().String(),
+					})
+				}
+			}
+		}
+
+		userMap := make(map[string]string, len(rule.Users))
+		for _, user := range rule.Users {
+			userMap[user] = "="
+		}
+		rules = append(rules, &tailcfg.SSHRule{
+			Principals: principals,
+			SSHUsers:   userMap,
+			Action:     &action,
+		})
+	}
+
+	return &tailcfg.SSHPolicy{
+		Rules: rules,
+	}, nil
+}
+
+func ipSetToPrefixStringList(ips *netipx.IPSet) []string {
+	var out []string
+
+	for _, pref := range ips.Prefixes() {
+		out = append(out, pref.String())
+	}
+	return out
+}

hscontrol/policyv2/policy.go

@@ -0,0 +1,80 @@
+package policyv2
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/juanfont/headscale/hscontrol/types"
+	"tailscale.com/tailcfg"
+)
+
+type PolicyManager struct {
+	mu    sync.Mutex
+	pol   *Policy
+	users []types.User
+	nodes types.Nodes
+
+	filter []tailcfg.FilterRule
+
+	// TODO(kradalby): Implement SSH policy
+	sshPolicy *tailcfg.SSHPolicy
+}
+
+// NewPolicyManager creates a new PolicyManager from a policy file and a list of users and nodes.
+// It returns an error if the policy file is invalid.
+// The policy manager will update the filter rules based on the users and nodes.
+func NewPolicyManager(b []byte, users []types.User, nodes types.Nodes) (*PolicyManager, error) {
+	policy, err := policyFromBytes(b)
+	if err != nil {
+		return nil, fmt.Errorf("parsing policy: %w", err)
+	}
+
+	pm := PolicyManager{
+		pol:   policy,
+		users: users,
+		nodes: nodes,
+	}
+
+	err = pm.updateLocked()
+	if err != nil {
+		return nil, err
+	}
+
+	return &pm, nil
+}
+
+// Filter returns the current filter rules for the entire tailnet.
+func (pm *PolicyManager) Filter() []tailcfg.FilterRule {
+	pm.mu.Lock()
+	defer pm.mu.Unlock()
+	return pm.filter
+}
+
+// updateLocked updates the filter rules based on the current policy and nodes.
+// It must be called with the lock held.
+func (pm *PolicyManager) updateLocked() error {
+	filter, err := pm.pol.CompileFilterRules(pm.users, pm.nodes)
+	if err != nil {
+		return fmt.Errorf("compiling filter rules: %w", err)
+	}
+
+	pm.filter = filter
+
+	return nil
+}
+
+// SetUsers updates the users in the policy manager and updates the filter rules.
+func (pm *PolicyManager) SetUsers(users []types.User) error {
+	pm.mu.Lock()
+	defer pm.mu.Unlock()
+	pm.users = users
+	return pm.updateLocked()
+}
+
+// SetNodes updates the nodes in the policy manager and updates the filter rules.
+func (pm *PolicyManager) SetNodes(nodes types.Nodes) error {
+	pm.mu.Lock()
+	defer pm.mu.Unlock()
+	pm.nodes = nodes
+	return pm.updateLocked()
+}

hscontrol/policyv2/policy_test.go

@@ -0,0 +1,58 @@
+package policyv2
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/juanfont/headscale/hscontrol/types"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm"
+	"tailscale.com/tailcfg"
+)
+
+func node(name, ipv4, ipv6 string, user types.User, hostinfo *tailcfg.Hostinfo) *types.Node {
+	return &types.Node{
+		ID:       0,
+		Hostname: name,
+		IPv4:     ap(ipv4),
+		IPv6:     ap(ipv6),
+		User:     user,
+		UserID:   user.ID,
+		Hostinfo: hostinfo,
+	}
+}
+
+func TestPolicyManager(t *testing.T) {
+	users := types.Users{
+		{Model: gorm.Model{ID: 1}, Name: "testuser", Email: "testuser@headscale.net"},
+		{Model: gorm.Model{ID: 2}, Name: "otheruser", Email: "otheruser@headscale.net"},
+	}
+
+	tests := []struct {
+		name       string
+		pol        string
+		nodes      types.Nodes
+		wantFilter []tailcfg.FilterRule
+	}{
+		{
+			name:       "empty-policy",
+			pol:        "{}",
+			nodes:      types.Nodes{},
+			wantFilter: nil,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			pm, err := NewPolicyManager([]byte(tt.pol), users, tt.nodes)
+			require.NoError(t, err)
+
+			filter := pm.Filter()
+			if diff := cmp.Diff(filter, tt.wantFilter); diff != "" {
+				t.Errorf("Filter() mismatch (-want +got):\n%s", diff)
+			}
+
+			// TODO(kradalby): Test SSH Policy
+		})
+	}
+}

hscontrol/policyv2/types.go

@@ -0,0 +1,821 @@
+package policyv2
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/netip"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/juanfont/headscale/hscontrol/types"
+	"github.com/juanfont/headscale/hscontrol/util"
+	"github.com/tailscale/hujson"
+	"go4.org/netipx"
+	"tailscale.com/net/tsaddr"
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/ptr"
+)
+
+var theInternetSet *netipx.IPSet
+
+// theInternet returns the IPSet for the Internet.
+// https://www.youtube.com/watch?v=iDbyYGrswtg
+func theInternet() *netipx.IPSet {
+	if theInternetSet != nil {
+		return theInternetSet
+	}
+
+	var internetBuilder netipx.IPSetBuilder
+	internetBuilder.AddPrefix(netip.MustParsePrefix("2000::/3"))
+	internetBuilder.AddPrefix(tsaddr.AllIPv4())
+
+	// Delete Private network addresses
+	// https://datatracker.ietf.org/doc/html/rfc1918
+	internetBuilder.RemovePrefix(netip.MustParsePrefix("fc00::/7"))
+	internetBuilder.RemovePrefix(netip.MustParsePrefix("10.0.0.0/8"))
+	internetBuilder.RemovePrefix(netip.MustParsePrefix("172.16.0.0/12"))
+	internetBuilder.RemovePrefix(netip.MustParsePrefix("192.168.0.0/16"))
+
+	// Delete Tailscale networks
+	internetBuilder.RemovePrefix(tsaddr.TailscaleULARange())
+	internetBuilder.RemovePrefix(tsaddr.CGNATRange())
+
+	// Delete "cant find DHCP networks"
+	internetBuilder.RemovePrefix(netip.MustParsePrefix("fe80::/10")) // link-loca
+	internetBuilder.RemovePrefix(netip.MustParsePrefix("169.254.0.0/16"))
+
+	theInternetSet, _ := internetBuilder.IPSet()
+	return theInternetSet
+}
+
+type Asterix int
+
+func (a Asterix) Validate() error {
+	return nil
+}
+
+func (a Asterix) String() string {
+	return "*"
+}
+
+func (a Asterix) UnmarshalJSON(b []byte) error {
+	return nil
+}
+
+func (a Asterix) Resolve(_ *Policy, _ types.Users, nodes types.Nodes) (*netipx.IPSet, error) {
+	var ips netipx.IPSetBuilder
+
+	ips.AddPrefix(tsaddr.AllIPv4())
+	ips.AddPrefix(tsaddr.AllIPv6())
+
+	return ips.IPSet()
+}
+
+// Username is a string that represents a username, it must contain an @.
+type Username string
+
+func (u Username) Validate() error {
+	if strings.Contains(string(u), "@") {
+		return nil
+	}
+	return fmt.Errorf("Username has to contain @, got: %q", u)
+}
+
+func (u *Username) String() string {
+	return string(*u)
+}
+
+func (u *Username) UnmarshalJSON(b []byte) error {
+	*u = Username(strings.Trim(string(b), `"`))
+	if err := u.Validate(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (u Username) CanBeTagOwner() bool {
+	return true
+}
+
+func (u Username) resolveUser(users types.Users) (*types.User, error) {
+	var potentialUsers types.Users
+	for _, user := range users {
+		if user.ProviderIdentifier == string(u) {
+			potentialUsers = append(potentialUsers, user)
+
+			break
+		}
+		if user.Email == string(u) {
+			potentialUsers = append(potentialUsers, user)
+		}
+		if user.Name == string(u) {
+			potentialUsers = append(potentialUsers, user)
+		}
+	}
+
+	if len(potentialUsers) > 1 {
+		return nil, fmt.Errorf("unable to resolve user identifier to distinct: %s matched multiple %s", u, potentialUsers)
+	} else if len(potentialUsers) == 0 {
+		return nil, fmt.Errorf("unable to resolve user identifier, no user found: %s not in %s", u, users)
+	}
+
+	user := potentialUsers[0]
+
+	return &user, nil
+}
+
+func (u Username) Resolve(_ *Policy, users types.Users, nodes types.Nodes) (*netipx.IPSet, error) {
+	var ips netipx.IPSetBuilder
+
+	user, err := u.resolveUser(users)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, node := range nodes {
+		if node.IsTagged() {
+			continue
+		}
+
+		if node.User.ID == user.ID {
+			node.AppendToIPSet(&ips)
+		}
+	}
+
+	return ips.IPSet()
+}
+
+// Group is a special string which is always prefixed with `group:`
+type Group string
+
+func (g Group) Validate() error {
+	if strings.HasPrefix(string(g), "group:") {
+		return nil
+	}
+	return fmt.Errorf(`Group has to start with "group:", got: %q`, g)
+}
+
+func (g *Group) UnmarshalJSON(b []byte) error {
+	*g = Group(strings.Trim(string(b), `"`))
+	if err := g.Validate(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (g Group) CanBeTagOwner() bool {
+	return true
+}
+
+func (g Group) Resolve(p *Policy, users types.Users, nodes types.Nodes) (*netipx.IPSet, error) {
+	var ips netipx.IPSetBuilder
+
+	for _, user := range p.Groups[g] {
+		uips, err := user.Resolve(nil, users, nodes)
+		if err != nil {
+			return nil, err
+		}
+
+		ips.AddSet(uips)
+	}
+
+	return ips.IPSet()
+}
+
+// Tag is a special string which is always prefixed with `tag:`
+type Tag string
+
+func (t Tag) Validate() error {
+	if strings.HasPrefix(string(t), "tag:") {
+		return nil
+	}
+	return fmt.Errorf(`tag has to start with "tag:", got: %q`, t)
+}
+
+func (t *Tag) UnmarshalJSON(b []byte) error {
+	*t = Tag(strings.Trim(string(b), `"`))
+	if err := t.Validate(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (t Tag) Resolve(p *Policy, _ types.Users, nodes types.Nodes) (*netipx.IPSet, error) {
+	var ips netipx.IPSetBuilder
+
+	for _, node := range nodes {
+		if node.HasTag(string(t)) {
+			node.AppendToIPSet(&ips)
+		}
+	}
+
+	return ips.IPSet()
+}
+
+// Host is a string that represents a hostname.
+type Host string
+
+func (h Host) Validate() error {
+	return nil
+}
+
+func (h *Host) UnmarshalJSON(b []byte) error {
+	*h = Host(strings.Trim(string(b), `"`))
+	if err := h.Validate(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (h Host) Resolve(p *Policy, _ types.Users, nodes types.Nodes) (*netipx.IPSet, error) {
+	var ips netipx.IPSetBuilder
+
+	pref, ok := p.Hosts[h]
+	if !ok {
+		return nil, fmt.Errorf("unable to resolve host: %q", h)
+	}
+	err := pref.Validate()
+	if err != nil {
+		return nil, err
+	}
+
+	// If the IP is a single host, look for a node to ensure we add all the IPs of
+	// the node to the IPSet.
+	appendIfNodeHasIP(nodes, &ips, pref)
+	ips.AddPrefix(netip.Prefix(pref))
+
+	return ips.IPSet()
+}
+
+func appendIfNodeHasIP(nodes types.Nodes, ips *netipx.IPSetBuilder, pref Prefix) {
+	if netip.Prefix(pref).IsSingleIP() {
+		addr := netip.Prefix(pref).Addr()
+		for _, node := range nodes {
+			if node.HasIP(addr) {
+				node.AppendToIPSet(ips)
+			}
+		}
+	}
+}
+
+type Prefix netip.Prefix
+
+func (p Prefix) Validate() error {
+	if !netip.Prefix(p).IsValid() {
+		return fmt.Errorf("Prefix %q is invalid", p)
+	}
+
+	return nil
+}
+
+func (p Prefix) String() string {
+	return netip.Prefix(p).String()
+}
+
+func (p *Prefix) parseString(addr string) error {
+	if !strings.Contains(addr, "/") {
+		addr, err := netip.ParseAddr(addr)
+		if err != nil {
+			return err
+		}
+		addrPref, err := addr.Prefix(addr.BitLen())
+		if err != nil {
+			return err
+		}
+
+		*p = Prefix(addrPref)
+		return nil
+	}
+
+	pref, err := netip.ParsePrefix(addr)
+	if err != nil {
+		return err
+	}
+	*p = Prefix(pref)
+	return nil
+}
+
+func (p *Prefix) UnmarshalJSON(b []byte) error {
+	err := p.parseString(strings.Trim(string(b), `"`))
+	if err != nil {
+		return err
+	}
+	if err := p.Validate(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (p Prefix) Resolve(_ *Policy, _ types.Users, nodes types.Nodes) (*netipx.IPSet, error) {
+	var ips netipx.IPSetBuilder
+
+	appendIfNodeHasIP(nodes, &ips, p)
+	ips.AddPrefix(netip.Prefix(p))
+
+	return ips.IPSet()
+}
+
+// AutoGroup is a special string which is always prefixed with `autogroup:`
+type AutoGroup string
+
+const (
+	AutoGroupInternet = "autogroup:internet"
+)
+
+var autogroups = []string{AutoGroupInternet}
+
+func (ag AutoGroup) Validate() error {
+	for _, valid := range autogroups {
+		if valid == string(ag) {
+			return nil
+		}
+	}
+
+	return fmt.Errorf("AutoGroup is invalid, got: %q, must be one of %v", ag, autogroups)
+}
+
+func (ag *AutoGroup) UnmarshalJSON(b []byte) error {
+	*ag = AutoGroup(strings.Trim(string(b), `"`))
+	if err := ag.Validate(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (ag AutoGroup) Resolve(_ *Policy, _ types.Users, _ types.Nodes) (*netipx.IPSet, error) {
+	switch ag {
+	case AutoGroupInternet:
+		return theInternet(), nil
+	}
+
+	return nil, nil
+}
+
+type Alias interface {
+	Validate() error
+	UnmarshalJSON([]byte) error
+	Resolve(*Policy, types.Users, types.Nodes) (*netipx.IPSet, error)
+}
+
+type AliasWithPorts struct {
+	Alias
+	Ports []tailcfg.PortRange
+}
+
+func (ve *AliasWithPorts) UnmarshalJSON(b []byte) error {
+	// TODO(kradalby): use encoding/json/v2 (go-json-experiment)
+	dec := json.NewDecoder(bytes.NewReader(b))
+	var v any
+	if err := dec.Decode(&v); err != nil {
+		return err
+	}
+
+	switch vs := v.(type) {
+	case string:
+		var portsPart string
+		var err error
+
+		if strings.Contains(vs, ":") {
+			vs, portsPart, err = splitDestination(vs)
+			if err != nil {
+				return err
+			}
+
+			ports, err := parsePorts(portsPart)
+			if err != nil {
+				return err
+			}
+			ve.Ports = ports
+		}
+
+		ve.Alias = parseAlias(vs)
+		if ve.Alias == nil {
+			return fmt.Errorf("could not determine the type of %q", vs)
+		}
+		if err := ve.Alias.Validate(); err != nil {
+			return err
+		}
+
+	default:
+		return fmt.Errorf("type %T not supported", vs)
+	}
+	return nil
+}
+
+func parseAlias(vs string) Alias {
+	// case netip.Addr:
+	// 	ve.Alias = Addr(val)
+	// case netip.Prefix:
+	// 	ve.Alias = Prefix(val)
+	var pref Prefix
+	err := pref.parseString(vs)
+	if err == nil {
+		return &pref
+	}
+
+	switch {
+	case vs == "*":
+		return Asterix(0)
+	case strings.Contains(vs, "@"):
+		return ptr.To(Username(vs))
+	case strings.HasPrefix(vs, "group:"):
+		return ptr.To(Group(vs))
+	case strings.HasPrefix(vs, "tag:"):
+		return ptr.To(Tag(vs))
+	case strings.HasPrefix(vs, "autogroup:"):
+		return ptr.To(AutoGroup(vs))
+	}
+
+	if !strings.Contains(vs, "@") && !strings.Contains(vs, ":") {
+		return ptr.To(Host(vs))
+	}
+
+	return nil
+}
+
+// AliasEnc is used to deserialize a Alias.
+type AliasEnc struct{ Alias }
+
+func (ve *AliasEnc) UnmarshalJSON(b []byte) error {
+	// TODO(kradalby): use encoding/json/v2 (go-json-experiment)
+	dec := json.NewDecoder(bytes.NewReader(b))
+	var v any
+	if err := dec.Decode(&v); err != nil {
+		return err
+	}
+	switch val := v.(type) {
+	case string:
+		ve.Alias = parseAlias(val)
+		if ve.Alias == nil {
+			return fmt.Errorf("could not determine the type of %q", val)
+		}
+		if err := ve.Alias.Validate(); err != nil {
+			return err
+		}
+	default:
+		return fmt.Errorf("type %T not supported", val)
+	}
+	return nil
+}
+
+type Aliases []Alias
+
+func (a *Aliases) UnmarshalJSON(b []byte) error {
+	var aliases []AliasEnc
+	err := json.Unmarshal(b, &aliases)
+	if err != nil {
+		return err
+	}
+
+	*a = make([]Alias, len(aliases))
+	for i, alias := range aliases {
+		(*a)[i] = alias.Alias
+	}
+	return nil
+}
+
+func (a Aliases) Resolve(p *Policy, users types.Users, nodes types.Nodes) (*netipx.IPSet, error) {
+	var ips netipx.IPSetBuilder
+
+	for _, alias := range a {
+		aips, err := alias.Resolve(p, users, nodes)
+		if err != nil {
+			return nil, err
+		}
+
+		ips.AddSet(aips)
+	}
+
+	return ips.IPSet()
+}
+
+type Owner interface {
+	CanBeTagOwner() bool
+	UnmarshalJSON([]byte) error
+}
+
+// OwnerEnc is used to deserialize a Owner.
+type OwnerEnc struct{ Owner }
+
+func (ve *OwnerEnc) UnmarshalJSON(b []byte) error {
+	// TODO(kradalby): use encoding/json/v2 (go-json-experiment)
+	dec := json.NewDecoder(bytes.NewReader(b))
+	var v any
+	if err := dec.Decode(&v); err != nil {
+		return err
+	}
+	switch val := v.(type) {
+	case string:
+
+		switch {
+		case strings.Contains(val, "@"):
+			ve.Owner = ptr.To(Username(val))
+		case strings.HasPrefix(val, "group:"):
+			ve.Owner = ptr.To(Group(val))
+		}
+	default:
+		return fmt.Errorf("type %T not supported", val)
+	}
+	return nil
+}
+
+type Owners []Owner
+
+func (o *Owners) UnmarshalJSON(b []byte) error {
+	var owners []OwnerEnc
+	err := json.Unmarshal(b, &owners)
+	if err != nil {
+		return err
+	}
+
+	*o = make([]Owner, len(owners))
+	for i, owner := range owners {
+		(*o)[i] = owner.Owner
+	}
+	return nil
+}
+
+type Usernames []Username
+
+// Groups are a map of Group to a list of Username.
+type Groups map[Group]Usernames
+
+// Hosts are alias for IP addresses or subnets.
+type Hosts map[Host]Prefix
+
+// TagOwners are a map of Tag to a list of the UserEntities that own the tag.
+type TagOwners map[Tag]Owners
+
+type AutoApprovers struct {
+	Routes   map[string][]string `json:"routes"`
+	ExitNode []string            `json:"exitNode"`
+}
+
+type ACL struct {
+	Action       string           `json:"action"`
+	Protocol     string           `json:"proto"`
+	Sources      Aliases          `json:"src"`
+	Destinations []AliasWithPorts `json:"dst"`
+}
+
+// Policy represents a Tailscale Network Policy.
+// TODO(kradalby):
+// Add validation method checking:
+// All users exists
+// All groups and users are valid tag TagOwners
+// Everything referred to in ACLs exists in other
+// entities.
+type Policy struct {
+	// validated is set if the policy has been validated.
+	// It is not safe to use before it is validated, and
+	// callers using it should panic if not
+	validated bool `json:"-"`
+
+	Groups        Groups        `json:"groups"`
+	Hosts         Hosts         `json:"hosts"`
+	TagOwners     TagOwners     `json:"tagOwners"`
+	ACLs          []ACL         `json:"acls"`
+	AutoApprovers AutoApprovers `json:"autoApprovers"`
+	SSHs          []SSH         `json:"ssh"`
+}
+
+// SSH controls who can ssh into which machines.
+type SSH struct {
+	Action       string        `json:"action"`
+	Sources      SSHSrcAliases `json:"src"`
+	Destinations SSHDstAliases `json:"dst"`
+	Users        []SSHUser     `json:"users"`
+	CheckPeriod  time.Duration `json:"checkPeriod,omitempty"`
+}
+
+// SSHSrcAliases is a list of aliases that can be used as sources in an SSH rule.
+// It can be a list of usernames, groups, tags or autogroups.
+type SSHSrcAliases []Alias
+
+func (a *SSHSrcAliases) UnmarshalJSON(b []byte) error {
+	var aliases []AliasEnc
+	err := json.Unmarshal(b, &aliases)
+	if err != nil {
+		return err
+	}
+
+	*a = make([]Alias, len(aliases))
+	for i, alias := range aliases {
+		switch alias.Alias.(type) {
+		case *Username, *Group, *Tag, *AutoGroup:
+			(*a)[i] = alias.Alias
+		default:
+			return fmt.Errorf("type %T not supported", alias.Alias)
+		}
+	}
+	return nil
+}
+
+// SSHDstAliases is a list of aliases that can be used as destinations in an SSH rule.
+// It can be a list of usernames, tags or autogroups.
+type SSHDstAliases []Alias
+
+func (a *SSHDstAliases) UnmarshalJSON(b []byte) error {
+	var aliases []AliasEnc
+	err := json.Unmarshal(b, &aliases)
+	if err != nil {
+		return err
+	}
+
+	*a = make([]Alias, len(aliases))
+	for i, alias := range aliases {
+		switch alias.Alias.(type) {
+		case *Username, *Tag, *AutoGroup:
+			(*a)[i] = alias.Alias
+		default:
+			return fmt.Errorf("type %T not supported", alias.Alias)
+		}
+	}
+	return nil
+}
+
+type SSHUser string
+
+func policyFromBytes(b []byte) (*Policy, error) {
+	var policy Policy
+	ast, err := hujson.Parse(b)
+	if err != nil {
+		return nil, fmt.Errorf("parsing HuJSON: %w", err)
+	}
+
+	ast.Standardize()
+	acl := ast.Pack()
+
+	err = json.Unmarshal(acl, &policy)
+	if err != nil {
+		return nil, fmt.Errorf("parsing policy from bytes: %w", err)
+	}
+
+	return &policy, nil
+}
+
+const (
+	expectedTokenItems = 2
+)
+
+// TODO(kradalby): copy tests from parseDestination in policy
+func splitDestination(dest string) (string, string, error) {
+	var tokens []string
+
+	// Check if there is a IPv4/6:Port combination, IPv6 has more than
+	// three ":".
+	tokens = strings.Split(dest, ":")
+	if len(tokens) < expectedTokenItems || len(tokens) > 3 {
+		port := tokens[len(tokens)-1]
+
+		maybeIPv6Str := strings.TrimSuffix(dest, ":"+port)
+
+		filteredMaybeIPv6Str := maybeIPv6Str
+		if strings.Contains(maybeIPv6Str, "/") {
+			networkParts := strings.Split(maybeIPv6Str, "/")
+			filteredMaybeIPv6Str = networkParts[0]
+		}
+
+		if maybeIPv6, err := netip.ParseAddr(filteredMaybeIPv6Str); err != nil && !maybeIPv6.Is6() {
+			return "", "", fmt.Errorf(
+				"failed to split destination: %v",
+				tokens,
+			)
+		} else {
+			tokens = []string{maybeIPv6Str, port}
+		}
+	}
+
+	var alias string
+	// We can have here stuff like:
+	// git-server:*
+	// 192.168.1.0/24:22
+	// fd7a:115c:a1e0::2:22
+	// fd7a:115c:a1e0::2/128:22
+	// tag:montreal-webserver:80,443
+	// tag:api-server:443
+	// example-host-1:*
+	if len(tokens) == expectedTokenItems {
+		alias = tokens[0]
+	} else {
+		alias = fmt.Sprintf("%s:%s", tokens[0], tokens[1])
+	}
+
+	return alias, tokens[len(tokens)-1], nil
+}
+
+// TODO(kradalby): write/copy tests from expandPorts in policy
+func parsePorts(portsStr string) ([]tailcfg.PortRange, error) {
+	if portsStr == "*" {
+		return []tailcfg.PortRange{
+			tailcfg.PortRangeAny,
+		}, nil
+	}
+
+	var ports []tailcfg.PortRange
+	for _, portStr := range strings.Split(portsStr, ",") {
+		rang := strings.Split(portStr, "-")
+		switch len(rang) {
+		case 1:
+			port, err := strconv.ParseUint(rang[0], util.Base10, util.BitSize16)
+			if err != nil {
+				return nil, err
+			}
+			ports = append(ports, tailcfg.PortRange{
+				First: uint16(port),
+				Last:  uint16(port),
+			})
+
+		case expectedTokenItems:
+			start, err := strconv.ParseUint(rang[0], util.Base10, util.BitSize16)
+			if err != nil {
+				return nil, err
+			}
+			last, err := strconv.ParseUint(rang[1], util.Base10, util.BitSize16)
+			if err != nil {
+				return nil, err
+			}
+			ports = append(ports, tailcfg.PortRange{
+				First: uint16(start),
+				Last:  uint16(last),
+			})
+
+		default:
+			return nil, errors.New("invalid ports")
+		}
+	}
+
+	return ports, nil
+}
+
+// For some reason golang.org/x/net/internal/iana is an internal package.
+const (
+	protocolICMP     = 1   // Internet Control Message
+	protocolIGMP     = 2   // Internet Group Management
+	protocolIPv4     = 4   // IPv4 encapsulation
+	protocolTCP      = 6   // Transmission Control
+	protocolEGP      = 8   // Exterior Gateway Protocol
+	protocolIGP      = 9   // any private interior gateway (used by Cisco for their IGRP)
+	protocolUDP      = 17  // User Datagram
+	protocolGRE      = 47  // Generic Routing Encapsulation
+	protocolESP      = 50  // Encap Security Payload
+	protocolAH       = 51  // Authentication Header
+	protocolIPv6ICMP = 58  // ICMP for IPv6
+	protocolSCTP     = 132 // Stream Control Transmission Protocol
+	ProtocolFC       = 133 // Fibre Channel
+)
+
+// parseProtocol reads the proto field of the ACL and generates a list of
+// protocols that will be allowed, following the IANA IP protocol number
+// https://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml
+//
+// If the ACL proto field is empty, it allows ICMPv4, ICMPv6, TCP, and UDP,
+// as per Tailscale behaviour (see tailcfg.FilterRule).
+//
+// Also returns a boolean indicating if the protocol
+// requires all the destinations to use wildcard as port number (only TCP,
+// UDP and SCTP support specifying ports).
+func parseProtocol(protocol string) ([]int, bool, error) {
+	switch protocol {
+	case "":
+		return nil, false, nil
+	case "igmp":
+		return []int{protocolIGMP}, true, nil
+	case "ipv4", "ip-in-ip":
+		return []int{protocolIPv4}, true, nil
+	case "tcp":
+		return []int{protocolTCP}, false, nil
+	case "egp":
+		return []int{protocolEGP}, true, nil
+	case "igp":
+		return []int{protocolIGP}, true, nil
+	case "udp":
+		return []int{protocolUDP}, false, nil
+	case "gre":
+		return []int{protocolGRE}, true, nil
+	case "esp":
+		return []int{protocolESP}, true, nil
+	case "ah":
+		return []int{protocolAH}, true, nil
+	case "sctp":
+		return []int{protocolSCTP}, false, nil
+	case "icmp":
+		return []int{protocolICMP, protocolIPv6ICMP}, true, nil
+
+	default:
+		protocolNumber, err := strconv.Atoi(protocol)
+		if err != nil {
+			return nil, false, fmt.Errorf("parsing protocol number: %w", err)
+		}
+
+		// TODO(kradalby): What is this?
+		needsWildcard := protocolNumber != protocolTCP &&
+			protocolNumber != protocolUDP &&
+			protocolNumber != protocolSCTP
+
+		return []int{protocolNumber}, needsWildcard, nil
+	}
+}

hscontrol/policyv2/types_test.go

@@ -0,0 +1,555 @@
+package policyv2
+
+import (
+	"net/netip"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
+	"github.com/juanfont/headscale/hscontrol/types"
+	"github.com/juanfont/headscale/hscontrol/util"
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/ptr"
+)
+
+func TestUnmarshalPolicy(t *testing.T) {
+	tests := []struct {
+		name    string
+		input   string
+		want    *Policy
+		wantErr string
+	}{
+		{
+			name:  "empty",
+			input: "{}",
+			want:  &Policy{},
+		},
+		{
+			name: "groups",
+			input: `
+{
+	"groups": {
+		"group:example": [
+			"derp@headscale.net",
+		],
+	},
+}
+`,
+			want: &Policy{
+				Groups: Groups{
+					Group("group:example"): []Username{Username("derp@headscale.net")},
+				},
+			},
+		},
+		{
+			name: "basic-types",
+			input: `
+{
+	"groups": {
+		"group:example": [
+			"testuser@headscale.net",
+		],
+		"group:other": [
+			"otheruser@headscale.net",
+		],
+	},
+
+	"tagOwners": {
+		"tag:user": ["testuser@headscale.net"],
+		"tag:group": ["group:other"],
+		"tag:userandgroup": ["testuser@headscale.net", "group:other"],
+	},
+
+	"hosts": {
+		"host-1": "100.100.100.100",
+		"subnet-1": "100.100.101.100/24",
+		"outside": "192.168.0.0/16",
+	},
+
+	"acls": [
+	    // All
+		{
+			"action": "accept",
+			"proto": "tcp",
+			"src": ["*"],
+			"dst": ["*:*"],
+		},
+		// Users
+		{
+			"action": "accept",
+			"proto": "tcp",
+			"src": ["testuser@headscale.net"],
+			"dst": ["otheruser@headscale.net:80"],
+		},
+		// Groups
+		{
+			"action": "accept",
+			"proto": "tcp",
+			"src": ["group:example"],
+			"dst": ["group:other:80"],
+		},
+		// Tailscale IP
+		{
+			"action": "accept",
+			"proto": "tcp",
+			"src": ["100.101.102.103"],
+			"dst": ["100.101.102.104:80"],
+		},
+		// Subnet
+		{
+			"action": "accept",
+			"proto": "udp",
+			"src": ["10.0.0.0/8"],
+			"dst": ["172.16.0.0/16:80"],
+		},
+		// Hosts
+		{
+			"action": "accept",
+			"proto": "tcp",
+			"src": ["subnet-1"],
+			"dst": ["host-1:80-88"],
+		},
+		// Tags
+		{
+			"action": "accept",
+			"proto": "tcp",
+			"src": ["tag:group"],
+			"dst": ["tag:user:80,443"],
+		},
+		// Autogroup
+		{
+			"action": "accept",
+			"proto": "tcp",
+			"src": ["tag:group"],
+			"dst": ["autogroup:internet:80"],
+		},
+	],
+}
+`,
+			want: &Policy{
+				Groups: Groups{
+					Group("group:example"): []Username{Username("testuser@headscale.net")},
+					Group("group:other"):   []Username{Username("otheruser@headscale.net")},
+				},
+				TagOwners: TagOwners{
+					Tag("tag:user"):         Owners{up("testuser@headscale.net")},
+					Tag("tag:group"):        Owners{gp("group:other")},
+					Tag("tag:userandgroup"): Owners{up("testuser@headscale.net"), gp("group:other")},
+				},
+				Hosts: Hosts{
+					"host-1":   Prefix(netip.MustParsePrefix("100.100.100.100/32")),
+					"subnet-1": Prefix(netip.MustParsePrefix("100.100.101.100/24")),
+					"outside":  Prefix(netip.MustParsePrefix("192.168.0.0/16")),
+				},
+				ACLs: []ACL{
+					{
+						Action:   "accept",
+						Protocol: "tcp",
+						Sources: Aliases{
+							// TODO(kradalby): Should this be host?
+							// It is:
+							// All traffic originating from Tailscale devices in your tailnet,
+							// any approved subnets and autogroup:shared.
+							// It does not allow traffic originating from
+							// non-tailscale devices (unless it is an approved route).
+							hp("*"),
+						},
+						Destinations: []AliasWithPorts{
+							{
+								// TODO(kradalby): Should this be host?
+								// It is:
+								// Includes any destination (no restrictions).
+								Alias: hp("*"),
+								Ports: []tailcfg.PortRange{tailcfg.PortRangeAny},
+							},
+						},
+					},
+					{
+						Action:   "accept",
+						Protocol: "tcp",
+						Sources: Aliases{
+							ptr.To(Username("testuser@headscale.net")),
+						},
+						Destinations: []AliasWithPorts{
+							{
+								Alias: ptr.To(Username("otheruser@headscale.net")),
+								Ports: []tailcfg.PortRange{{First: 80, Last: 80}},
+							},
+						},
+					},
+					{
+						Action:   "accept",
+						Protocol: "tcp",
+						Sources: Aliases{
+							gp("group:example"),
+						},
+						Destinations: []AliasWithPorts{
+							{
+								Alias: gp("group:other"),
+								Ports: []tailcfg.PortRange{{First: 80, Last: 80}},
+							},
+						},
+					},
+					{
+						Action:   "accept",
+						Protocol: "tcp",
+						Sources: Aliases{
+							pp("100.101.102.103/32"),
+						},
+						Destinations: []AliasWithPorts{
+							{
+								Alias: pp("100.101.102.104/32"),
+								Ports: []tailcfg.PortRange{{First: 80, Last: 80}},
+							},
+						},
+					},
+					{
+						Action:   "accept",
+						Protocol: "udp",
+						Sources: Aliases{
+							pp("10.0.0.0/8"),
+						},
+						Destinations: []AliasWithPorts{
+							{
+								Alias: pp("172.16.0.0/16"),
+								Ports: []tailcfg.PortRange{{First: 80, Last: 80}},
+							},
+						},
+					},
+					{
+						Action:   "accept",
+						Protocol: "tcp",
+						Sources: Aliases{
+							hp("subnet-1"),
+						},
+						Destinations: []AliasWithPorts{
+							{
+								Alias: hp("host-1"),
+								Ports: []tailcfg.PortRange{{First: 80, Last: 88}},
+							},
+						},
+					},
+					{
+						Action:   "accept",
+						Protocol: "tcp",
+						Sources: Aliases{
+							tp("tag:group"),
+						},
+						Destinations: []AliasWithPorts{
+							{
+								Alias: tp("tag:user"),
+								Ports: []tailcfg.PortRange{
+									{First: 80, Last: 80},
+									{First: 443, Last: 443},
+								},
+							},
+						},
+					},
+					{
+						Action:   "accept",
+						Protocol: "tcp",
+						Sources: Aliases{
+							tp("tag:group"),
+						},
+						Destinations: []AliasWithPorts{
+							{
+								Alias: agp("autogroup:internet"),
+								Ports: []tailcfg.PortRange{
+									{First: 80, Last: 80},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "invalid-username",
+			input: `
+{
+	"groups": {
+		"group:example": [
+			"valid@",
+			"invalid",
+		],
+	},
+}
+`,
+			wantErr: `Username has to contain @, got: "invalid"`,
+		},
+		{
+			name: "invalid-group",
+			input: `
+{
+	"groups": {
+		"grou:example": [
+			"valid@",
+		],
+	},
+}
+`,
+			wantErr: `Group has to start with "group:", got: "grou:example"`,
+		},
+		{
+			name: "group-in-group",
+			input: `
+{
+	"groups": {
+		"group:inner": [],
+		"group:example": [
+			"group:inner",
+		],
+	},
+}
+`,
+			wantErr: `Username has to contain @, got: "group:inner"`,
+		},
+		{
+			name: "invalid-prefix",
+			input: `
+{
+	"hosts": {
+		"derp": "10.0",
+	},
+}
+`,
+			wantErr: `ParseAddr("10.0"): IPv4 address too short`,
+		},
+		{
+			name: "invalid-auto-group",
+			input: `
+{
+	"acls": [
+		// Autogroup
+		{
+			"action": "accept",
+			"proto": "tcp",
+			"src": ["tag:group"],
+			"dst": ["autogroup:invalid:80"],
+		},
+	],
+}
+`,
+			wantErr: `AutoGroup is invalid, got: "autogroup:invalid", must be one of [autogroup:internet]`,
+		},
+	}
+
+	cmps := append(util.Comparers, cmp.Comparer(func(x, y Prefix) bool {
+		return x == y
+	}))
+	cmps = append(cmps, cmpopts.IgnoreUnexported(Policy{}))
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			policy, err := policyFromBytes([]byte(tt.input))
+			// TODO(kradalby): This error checking is broken,
+			// but so is my brain, #longflight
+			if err == nil {
+				if tt.wantErr == "" {
+					return
+				}
+				t.Fatalf("got success; wanted error %q", tt.wantErr)
+			}
+			if err.Error() != tt.wantErr {
+				t.Fatalf("got error %q; want %q", err, tt.wantErr)
+				// } else if err.Error() == tt.wantErr {
+				// 	return
+			}
+
+			if err != nil {
+				t.Fatalf("unexpected err: %q", err)
+			}
+
+			if diff := cmp.Diff(tt.want, &policy, cmps...); diff != "" {
+				t.Fatalf("unexpected policy (-want +got):\n%s", diff)
+			}
+		})
+	}
+}
+
+func gp(s string) *Group          { return ptr.To(Group(s)) }
+func up(s string) *Username       { return ptr.To(Username(s)) }
+func hp(s string) *Host           { return ptr.To(Host(s)) }
+func tp(s string) *Tag            { return ptr.To(Tag(s)) }
+func agp(s string) *AutoGroup     { return ptr.To(AutoGroup(s)) }
+func mp(pref string) netip.Prefix { return netip.MustParsePrefix(pref) }
+func ap(addr string) *netip.Addr  { return ptr.To(netip.MustParseAddr(addr)) }
+func pp(pref string) *Prefix      { return ptr.To(Prefix(netip.MustParsePrefix(pref))) }
+func p(pref string) Prefix        { return Prefix(netip.MustParsePrefix(pref)) }
+
+func TestResolvePolicy(t *testing.T) {
+	tests := []struct {
+		name      string
+		nodes     types.Nodes
+		pol       *Policy
+		toResolve Alias
+		want      []netip.Prefix
+	}{
+		{
+			name:      "prefix",
+			toResolve: pp("100.100.101.101/32"),
+			want:      []netip.Prefix{mp("100.100.101.101/32")},
+		},
+		{
+			name: "host",
+			pol: &Policy{
+				Hosts: Hosts{
+					"testhost": p("100.100.101.102/32"),
+				},
+			},
+			toResolve: hp("testhost"),
+			want:      []netip.Prefix{mp("100.100.101.102/32")},
+		},
+		{
+			name:      "username",
+			toResolve: ptr.To(Username("testuser")),
+			nodes: types.Nodes{
+				// Not matching other user
+				{
+					User: types.User{
+						Name: "notme",
+					},
+					IPv4: ap("100.100.101.1"),
+				},
+				// Not matching forced tags
+				{
+					User: types.User{
+						Name: "testuser",
+					},
+					ForcedTags: []string{"tag:anything"},
+					IPv4:       ap("100.100.101.2"),
+				},
+				// not matchin pak tag
+				{
+					User: types.User{
+						Name: "testuser",
+					},
+					AuthKey: &types.PreAuthKey{
+						Tags: []string{"alsotagged"},
+					},
+					IPv4: ap("100.100.101.3"),
+				},
+				{
+					User: types.User{
+						Name: "testuser",
+					},
+					IPv4: ap("100.100.101.103"),
+				},
+				{
+					User: types.User{
+						Name: "testuser",
+					},
+					IPv4: ap("100.100.101.104"),
+				},
+			},
+			want: []netip.Prefix{mp("100.100.101.103/32"), mp("100.100.101.104/32")},
+		},
+		{
+			name:      "group",
+			toResolve: ptr.To(Group("group:testgroup")),
+			nodes: types.Nodes{
+				// Not matching other user
+				{
+					User: types.User{
+						Name: "notmetoo",
+					},
+					IPv4: ap("100.100.101.4"),
+				},
+				// Not matching forced tags
+				{
+					User: types.User{
+						Name: "groupuser",
+					},
+					ForcedTags: []string{"tag:anything"},
+					IPv4:       ap("100.100.101.5"),
+				},
+				// not matchin pak tag
+				{
+					User: types.User{
+						Name: "groupuser",
+					},
+					AuthKey: &types.PreAuthKey{
+						Tags: []string{"tag:alsotagged"},
+					},
+					IPv4: ap("100.100.101.6"),
+				},
+				{
+					User: types.User{
+						Name: "groupuser",
+					},
+					IPv4: ap("100.100.101.203"),
+				},
+				{
+					User: types.User{
+						Name: "groupuser",
+					},
+					IPv4: ap("100.100.101.204"),
+				},
+			},
+			pol: &Policy{
+				Groups: Groups{
+					"group:testgroup":  Usernames{"groupuser"},
+					"group:othergroup": Usernames{"notmetoo"},
+				},
+			},
+			want: []netip.Prefix{mp("100.100.101.203/32"), mp("100.100.101.204/32")},
+		},
+		{
+			name:      "tag",
+			toResolve: tp("tag:test"),
+			nodes: types.Nodes{
+				// Not matching other user
+				{
+					User: types.User{
+						Name: "notmetoo",
+					},
+					IPv4: ap("100.100.101.9"),
+				},
+				// Not matching forced tags
+				{
+					ForcedTags: []string{"tag:anything"},
+					IPv4:       ap("100.100.101.10"),
+				},
+				// not matchin pak tag
+				{
+					AuthKey: &types.PreAuthKey{
+						Tags: []string{"tag:alsotagged"},
+					},
+					IPv4: ap("100.100.101.11"),
+				},
+				// Not matching forced tags
+				{
+					ForcedTags: []string{"tag:test"},
+					IPv4:       ap("100.100.101.234"),
+				},
+				// not matchin pak tag
+				{
+					AuthKey: &types.PreAuthKey{
+						Tags: []string{"tag:test"},
+					},
+					IPv4: ap("100.100.101.239"),
+				},
+			},
+			// TODO(kradalby): tests handling TagOwners + hostinfo
+			pol:  &Policy{},
+			want: []netip.Prefix{mp("100.100.101.234/32"), mp("100.100.101.239/32")},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ips, err := tt.toResolve.Resolve(tt.pol,
+				types.Users{},
+				tt.nodes)
+			if err != nil {
+				t.Fatalf("failed to resolve: %s", err)
+			}
+
+			prefs := ips.Prefixes()
+
+			if diff := cmp.Diff(tt.want, prefs, util.Comparers...); diff != "" {
+				t.Fatalf("unexpected prefs (-want +got):\n%s", diff)
+			}
+		})
+	}
+}

hscontrol/types/node.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"net/netip"
+	"slices"
 	"strconv"
 	"strings"
 	"time"
@@ -134,6 +135,60 @@ func (node *Node) IPs() []netip.Addr {
 	return ret
 }
 
+// HasIP reports if a node has a given IP address.
+func (node *Node) HasIP(i netip.Addr) bool {
+	for _, ip := range node.IPs() {
+		if ip.Compare(i) == 0 {
+			return true
+		}
+	}
+	return false
+}
+
+// IsTagged reports if a device is tagged
+// and therefore should not be treated as a
+// user owned device.
+// Currently, this function only handles tags set
+// via CLI ("forced tags" and preauthkeys)
+func (node *Node) IsTagged() bool {
+	if len(node.ForcedTags) > 0 {
+		return true
+	}
+
+	if node.AuthKey != nil && len(node.AuthKey.Tags) > 0 {
+		return true
+	}
+
+	if node.Hostinfo == nil {
+		return false
+	}
+
+	// TODO(kradalby): Figure out how tagging should work
+	// and hostinfo.requestedtags.
+	// Do this in other work.
+
+	return false
+}
+
+// HasTag reports if a node has a given tag.
+// Currently, this function only handles tags set
+// via CLI ("forced tags" and preauthkeys)
+func (node *Node) HasTag(tag string) bool {
+	if slices.Contains(node.ForcedTags, tag) {
+		return true
+	}
+
+	if node.AuthKey != nil && slices.Contains(node.AuthKey.Tags, tag) {
+		return true
+	}
+
+	// TODO(kradalby): Figure out how tagging should work
+	// and hostinfo.requestedtags.
+	// Do this in other work.
+
+	return false
+}
+
 func (node *Node) Prefixes() []netip.Prefix {
 	addrs := []netip.Prefix{}
 	for _, nodeAddress := range node.IPs() {

hscontrol/types/users.go

@@ -2,7 +2,9 @@ package types
 
 import (
 	"cmp"
+	"fmt"
 	"strconv"
+	"strings"
 
 	v1 "github.com/juanfont/headscale/gen/go/headscale/v1"
 	"github.com/juanfont/headscale/hscontrol/util"
@@ -13,6 +15,19 @@ import (
 
 type UserID uint64
 
+type Users []User
+
+func (u Users) String() string {
+	var sb strings.Builder
+	sb.WriteString("[ ")
+	for _, user := range u {
+		fmt.Fprintf(&sb, "%d: %s, ", user.ID, user.Name)
+	}
+	sb.WriteString(" ]")
+
+	return sb.String()
+}
+
 // User is the way Headscale implements the concept of users in Tailscale
 //
 // At the end of the day, users in Tailscale are some kind of 'bubbles' or users