loads

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

hscontrol/policyv2/filter.go

@@ -0,0 +1,79 @@
+package policyv2
+
+import (
+	"errors"
+	"fmt"
+
+	"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(
+	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, 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, 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 ipSetToPrefixStringList(ips *netipx.IPSet) []string {
+	var out []string
+
+	for _, pref := range ips.Prefixes() {
+		out = append(out, pref.String())
+	}
+	return out
+}

hscontrol/policyv2/filter_test.go

@@ -0,0 +1,378 @@
+package policyv2
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/juanfont/headscale/hscontrol/types"
+	"tailscale.com/tailcfg"
+)
+
+// TODO(kradalby):
+// Convert policy.TestReduceFilterRules to take JSON
+// Move it here, run it against both old and new CompileFilterRules
+
+func TestParsing(t *testing.T) {
+	tests := []struct {
+		name    string
+		format  string
+		acl     string
+		want    []tailcfg.FilterRule
+		wantErr bool
+	}{
+		{
+			name:   "invalid-hujson",
+			format: "hujson",
+			acl: `
+{
+		`,
+			want:    []tailcfg.FilterRule{},
+			wantErr: true,
+		},
+		// The new parser will ignore all that is irrelevant
+		// 		{
+		// 			name:   "valid-hujson-invalid-content",
+		// 			format: "hujson",
+		// 			acl: `
+		// {
+		//   "valid_json": true,
+		//   "but_a_policy_though": false
+		// }
+		// 				`,
+		// 			want:    []tailcfg.FilterRule{},
+		// 			wantErr: true,
+		// 		},
+		// 		{
+		// 			name:   "invalid-cidr",
+		// 			format: "hujson",
+		// 			acl: `
+		// {"example-host-1": "100.100.100.100/42"}
+		// 				`,
+		// 			want:    []tailcfg.FilterRule{},
+		// 			wantErr: true,
+		// 		},
+		{
+			name:   "basic-rule",
+			format: "hujson",
+			acl: `
+{
+	"hosts": {
+		"host-1": "100.100.100.100",
+		"subnet-1": "100.100.101.100/24",
+	},
+
+	"acls": [
+		{
+			"action": "accept",
+			"src": [
+				"subnet-1",
+				"192.168.1.0/24"
+			],
+			"dst": [
+				"*:22,3389",
+				"host-1:*",
+			],
+		},
+	],
+}
+		`,
+			want: []tailcfg.FilterRule{
+				{
+					SrcIPs: []string{"100.100.101.0/24", "192.168.1.0/24"},
+					DstPorts: []tailcfg.NetPortRange{
+						{IP: "0.0.0.0/0", Ports: tailcfg.PortRange{First: 22, Last: 22}},
+						{IP: "0.0.0.0/0", Ports: tailcfg.PortRange{First: 3389, Last: 3389}},
+						{IP: "::/0", Ports: tailcfg.PortRange{First: 22, Last: 22}},
+						{IP: "::/0", Ports: tailcfg.PortRange{First: 3389, Last: 3389}},
+						{IP: "100.100.100.100/32", Ports: tailcfg.PortRangeAny},
+					},
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name:   "parse-protocol",
+			format: "hujson",
+			acl: `
+{
+	"hosts": {
+		"host-1": "100.100.100.100",
+		"subnet-1": "100.100.101.100/24",
+	},
+
+	"acls": [
+		{
+			"Action": "accept",
+			"src": [
+				"*",
+			],
+			"proto": "tcp",
+			"dst": [
+				"host-1:*",
+			],
+		},
+		{
+			"Action": "accept",
+			"src": [
+				"*",
+			],
+			"proto": "udp",
+			"dst": [
+				"host-1:53",
+			],
+		},
+		{
+			"Action": "accept",
+			"src": [
+				"*",
+			],
+			"proto": "icmp",
+			"dst": [
+				"host-1:*",
+			],
+		},
+	],
+}`,
+			want: []tailcfg.FilterRule{
+				{
+					SrcIPs: []string{"0.0.0.0/0", "::/0"},
+					DstPorts: []tailcfg.NetPortRange{
+						{IP: "100.100.100.100/32", Ports: tailcfg.PortRangeAny},
+					},
+					IPProto: []int{protocolTCP},
+				},
+				{
+					SrcIPs: []string{"0.0.0.0/0", "::/0"},
+					DstPorts: []tailcfg.NetPortRange{
+						{IP: "100.100.100.100/32", Ports: tailcfg.PortRange{First: 53, Last: 53}},
+					},
+					IPProto: []int{protocolUDP},
+				},
+				{
+					SrcIPs: []string{"0.0.0.0/0", "::/0"},
+					DstPorts: []tailcfg.NetPortRange{
+						{IP: "100.100.100.100/32", Ports: tailcfg.PortRangeAny},
+					},
+					IPProto: []int{protocolICMP, protocolIPv6ICMP},
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name:   "port-wildcard",
+			format: "hujson",
+			acl: `
+{
+	"hosts": {
+		"host-1": "100.100.100.100",
+		"subnet-1": "100.100.101.100/24",
+	},
+
+	"acls": [
+		{
+			"Action": "accept",
+			"src": [
+				"*",
+			],
+			"dst": [
+				"host-1:*",
+			],
+		},
+	],
+}
+`,
+			want: []tailcfg.FilterRule{
+				{
+					SrcIPs: []string{"0.0.0.0/0", "::/0"},
+					DstPorts: []tailcfg.NetPortRange{
+						{IP: "100.100.100.100/32", Ports: tailcfg.PortRangeAny},
+					},
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name:   "port-range",
+			format: "hujson",
+			acl: `
+{
+	"hosts": {
+		"host-1": "100.100.100.100",
+		"subnet-1": "100.100.101.100/24",
+	},
+
+	"acls": [
+		{
+			"action": "accept",
+			"src": [
+				"subnet-1",
+			],
+			"dst": [
+				"host-1:5400-5500",
+			],
+		},
+	],
+}
+`,
+			want: []tailcfg.FilterRule{
+				{
+					SrcIPs: []string{"100.100.101.0/24"},
+					DstPorts: []tailcfg.NetPortRange{
+						{
+							IP:    "100.100.100.100/32",
+							Ports: tailcfg.PortRange{First: 5400, Last: 5500},
+						},
+					},
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name:   "port-group",
+			format: "hujson",
+			acl: `
+{
+	"groups": {
+		"group:example": [
+			"testuser@",
+		],
+	},
+
+	"hosts": {
+		"host-1": "100.100.100.100",
+		"subnet-1": "100.100.101.100/24",
+	},
+
+	"acls": [
+		{
+			"action": "accept",
+			"src": [
+				"group:example",
+			],
+			"dst": [
+				"host-1:*",
+			],
+		},
+	],
+}
+`,
+			want: []tailcfg.FilterRule{
+				{
+					SrcIPs: []string{"200.200.200.200/32"},
+					DstPorts: []tailcfg.NetPortRange{
+						{IP: "100.100.100.100/32", Ports: tailcfg.PortRangeAny},
+					},
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name:   "port-user",
+			format: "hujson",
+			acl: `
+{
+	"hosts": {
+		"host-1": "100.100.100.100",
+		"subnet-1": "100.100.101.100/24",
+	},
+
+	"acls": [
+		{
+			"action": "accept",
+			"src": [
+				"testuser@",
+			],
+			"dst": [
+				"host-1:*",
+			],
+		},
+	],
+}
+`,
+			want: []tailcfg.FilterRule{
+				{
+					SrcIPs: []string{"200.200.200.200/32"},
+					DstPorts: []tailcfg.NetPortRange{
+						{IP: "100.100.100.100/32", Ports: tailcfg.PortRangeAny},
+					},
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name:   "ipv6",
+			format: "hujson",
+			acl: `
+{
+	"hosts": {
+		"host-1": "100.100.100.100/32",
+		"subnet-1": "100.100.101.100/24",
+	},
+
+	"acls": [
+		{
+			"action": "accept",
+			"src": [
+				"*",
+			],
+			"dst": [
+				"host-1:*",
+			],
+		},
+	],
+}
+`,
+			want: []tailcfg.FilterRule{
+				{
+					SrcIPs: []string{"0.0.0.0/0", "::/0"},
+					DstPorts: []tailcfg.NetPortRange{
+						{IP: "100.100.100.100/32", Ports: tailcfg.PortRangeAny},
+					},
+				},
+			},
+			wantErr: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			pol, err := PolicyFromBytes([]byte(tt.acl))
+			if tt.wantErr && err == nil {
+				t.Errorf("parsing() error = %v, wantErr %v", err, tt.wantErr)
+
+				return
+			} else if !tt.wantErr && err != nil {
+				t.Errorf("parsing() error = %v, wantErr %v", err, tt.wantErr)
+
+				return
+			}
+
+			if err != nil {
+				return
+			}
+
+			rules, err := pol.CompileFilterRules(types.Nodes{
+				&types.Node{
+					IPv4: ap("100.100.100.100"),
+				},
+				&types.Node{
+					IPv4: ap("200.200.200.200"),
+					User: types.User{
+						Name: "testuser",
+					},
+					Hostinfo: &tailcfg.Hostinfo{},
+				},
+			})
+
+			if (err != nil) != tt.wantErr {
+				t.Errorf("parsing() error = %v, wantErr %v", err, tt.wantErr)
+
+				return
+			}
+
+			if diff := cmp.Diff(tt.want, rules); diff != "" {
+				t.Errorf("parsing() unexpected result (-want +got):\n%s", diff)
+			}
+		})
+	}
+}

hscontrol/policyv2/types.go

@@ -9,123 +9,293 @@ import (
 	"strconv"
 	"strings"
 
+	"github.com/juanfont/headscale/hscontrol/types"
 	"github.com/juanfont/headscale/hscontrol/util"
-	"github.com/rs/zerolog/log"
+	"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 string
+
+func (a Asterix) Validate() error {
+	if a == "*" {
+		return nil
+	}
+	return fmt.Errorf(`Asterix can only be "*", got: %s`, a)
+}
+
+func (a *Asterix) String() string {
+	return string(*a)
+}
+
+func (a *Asterix) UnmarshalJSON(b []byte) error {
+	*a = "*"
+	return nil
+}
+
 // Username is a string that represents a username, it must contain an @.
 type Username string
 
-func (u Username) Valid() bool {
+func (u Username) Validate() error {
-	return strings.Contains(string(u), "@")
+	if strings.Contains(string(u), "@") {
+		return nil
+	}
+	return fmt.Errorf("Username has to contain @, got: %q", u)
 }
 
-func (u Username) UnmarshalJSON(b []byte) error {
+func (u *Username) String() string {
-	u = Username(strings.Trim(string(b), `"`))
+	return string(*u)
-	if !u.Valid() {
+}
-		return fmt.Errorf("invalid username %q", 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) Resolve(_ *Policy, nodes types.Nodes) (*netipx.IPSet, error) {
+	var ips netipx.IPSetBuilder
+
+	for _, node := range nodes {
+		if node.IsTagged() {
+			continue
+		}
+
+		if node.User.Username() == string(u) {
+			node.AppendToIPSet(&ips)
+		}
+	}
+
+	return ips.IPSet()
+}
+
 // Group is a special string which is always prefixed with `group:`
 type Group string
 
-func (g Group) Valid() bool {
+func (g Group) Validate() error {
-	return strings.HasPrefix(string(g), "group:")
+	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 !g.Valid() {
+	if err := g.Validate(); err != nil {
-		return fmt.Errorf("invalid group %q", g)
+		return err
 	}
 	return nil
 }
 
+func (g Group) CanBeTagOwner() bool {
+	return true
+}
+
+func (g Group) Resolve(p *Policy, nodes types.Nodes) (*netipx.IPSet, error) {
+	var ips netipx.IPSetBuilder
+
+	for _, user := range p.Groups[g] {
+		uips, err := user.Resolve(nil, 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) Valid() bool {
+func (t Tag) Validate() error {
-	return strings.HasPrefix(string(t), "tag:")
+	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 !t.Valid() {
+	if err := t.Validate(); err != nil {
-		return fmt.Errorf("invalid tag %q", t)
+		return err
 	}
 	return nil
 }
 
+func (t Tag) Resolve(p *Policy, 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) Valid() bool {
+func (h Host) Validate() error {
-	return true
+	return nil
 }
 
 func (h Host) UnmarshalJSON(b []byte) error {
 	h = Host(strings.Trim(string(b), `"`))
-	if !h.Valid() {
+	if err := h.Validate(); err != nil {
-		return fmt.Errorf("invalid host %q", h)
-	}
-	return nil
-}
-
-type Addr netip.Addr
-
-func (a Addr) Valid() bool {
-	return netip.Addr(a).IsValid()
-}
-
-func (a Addr) UnmarshalJSON(b []byte) error {
-	a = Addr(netip.Addr{})
-	if err := json.Unmarshal(b, (netip.Addr)(a)); err != nil {
 		return err
 	}
-	if !a.Valid() {
-		return fmt.Errorf("invalid address %v", a)
-	}
 	return nil
 }
 
+func (h Host) Resolve(p *Policy, nodes types.Nodes) (*netipx.IPSet, error) {
+	var ips netipx.IPSetBuilder
+
+	ips.AddPrefix(netip.Prefix(p.Hosts[h]))
+
+	return ips.IPSet()
+}
+
 type Prefix netip.Prefix
 
-func (p Prefix) Valid() bool {
+func (p Prefix) Validate() error {
-	return netip.Prefix(p).IsValid()
+	if !netip.Prefix(p).IsValid() {
+		return fmt.Errorf("Prefix %q is invalid", p)
+	}
+
+	return nil
 }
 
-func (p Prefix) UnmarshalJSON(b []byte) error {
+func (p Prefix) String() string {
-	p = Prefix(netip.Prefix{})
+	return netip.Prefix(p).String()
-	if err := json.Unmarshal(b, (netip.Prefix)(p)); err != nil {
+}
+
+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
 	}
-	if !p.Valid() {
+	*p = Prefix(pref)
-		return fmt.Errorf("invalid prefix %v", p)
+	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.Nodes) (*netipx.IPSet, error) {
+	var ips netipx.IPSetBuilder
+
+	ips.AddPrefix(netip.Prefix(p))
+
+	return ips.IPSet()
+}
+
 // AutoGroup is a special string which is always prefixed with `autogroup:`
 type AutoGroup string
 
-func (ag AutoGroup) Valid() bool {
+const (
-	return strings.HasPrefix(string(ag), "autogroup:")
+	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 !ag.Valid() {
+	if err := ag.Validate(); err != nil {
-		return fmt.Errorf("invalid autogroup %q", ag)
+		return err
 	}
 	return nil
 }
 
+func (ag AutoGroup) Resolve(_ *Policy, _ types.Nodes) (*netipx.IPSet, error) {
+	switch ag {
+	case AutoGroupInternet:
+		return theInternet(), nil
+	}
+
+	return nil, nil
+}
+
 type Alias interface {
-	Valid() bool
+	Validate() error
 	UnmarshalJSON([]byte) error
+	Resolve(*Policy, types.Nodes) (*netipx.IPSet, error)
 }
 
 type AliasWithPorts struct {
@@ -160,6 +330,9 @@ func (ve *AliasWithPorts) UnmarshalJSON(b []byte) error {
 		}
 
 		ve.Alias = parseAlias(vs)
+		if err := ve.Alias.Validate(); err != nil {
+			return err
+		}
 
 	default:
 		return fmt.Errorf("type %T not supported", vs)
@@ -172,19 +345,19 @@ func parseAlias(vs string) Alias {
 	// 	ve.Alias = Addr(val)
 	// case netip.Prefix:
 	// 	ve.Alias = Prefix(val)
-	if addr, err := netip.ParseAddr(vs); err == nil {
+	var pref Prefix
-		return Addr(addr)
+	err := pref.parseString(vs)
-	}
+	if err == nil {
-
+		return &pref
-	if prefix, err := netip.ParsePrefix(vs); err == nil {
-		return Prefix(prefix)
 	}
 
 	switch {
+	case vs == "*":
+		return ptr.To(Asterix("*"))
 	case strings.Contains(vs, "@"):
-		return Username(vs)
+		return ptr.To(Username(vs))
 	case strings.HasPrefix(vs, "group:"):
-		return Group(vs)
+		ptr.To(Group(vs))
 	case strings.HasPrefix(vs, "tag:"):
 		return Tag(vs)
 	case strings.HasPrefix(vs, "autogroup:"):
@@ -206,6 +379,10 @@ func (ve *AliasEnc) UnmarshalJSON(b []byte) error {
 	switch val := v.(type) {
 	case string:
 		ve.Alias = parseAlias(val)
+		ve.Alias = parseAlias(val)
+		if err := ve.Alias.Validate(); err != nil {
+			return err
+		}
 	default:
 		return fmt.Errorf("type %T not supported", val)
 	}
@@ -228,24 +405,78 @@ func (a *Aliases) UnmarshalJSON(b []byte) error {
 	return nil
 }
 
-// UserEntity is an interface that represents something that can
+func (a Aliases) Resolve(p *Policy, nodes types.Nodes) (*netipx.IPSet, error) {
-// return a list of users:
+	var ips netipx.IPSetBuilder
-// - Username
+
-// - Group
+	for _, alias := range a {
-// - AutoGroup
+		aips, err := alias.Resolve(p, nodes)
-type UserEntity interface {
+		if err != nil {
-	Users() []Username
+			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, "@"):
+			u := Username(val)
+			ve.Owner = &u
+		case strings.HasPrefix(val, "group:"):
+			ve.Owner = 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][]Username
+type Groups map[Group]Usernames
 
 // Hosts are alias for IP addresses or subnets.
-type Hosts map[Host]netip.Prefix
+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][]UserEntity
+type TagOwners map[Tag]Owners
 
 type AutoApprovers struct {
 	Routes   map[string][]string `json:"routes"`
@@ -259,16 +490,45 @@ type ACL struct {
 	Destinations []AliasWithPorts `json:"dst"`
 }
 
-// ACLPolicy represents a Tailscale ACL Policy.
+// Policy represents a Tailscale Network Policy.
-type ACLPolicy struct {
+// TODO(kradalby):
-	Groups Groups `json:"groups"`
+// Add validation method checking:
-	// Hosts         Hosts         `json:"hosts"`
+// 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"`
 }
 
+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
 )
@@ -329,7 +589,6 @@ func parsePorts(portsStr string) ([]tailcfg.PortRange, error) {
 
 	var ports []tailcfg.PortRange
 	for _, portStr := range strings.Split(portsStr, ",") {
-		log.Trace().Msgf("parsing portstring: %s", portStr)
 		rang := strings.Split(portStr, "-")
 		switch len(rang) {
 		case 1:
@@ -363,3 +622,72 @@ func parsePorts(portsStr string) ([]tailcfg.PortRange, error) {
 
 	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

@@ -1,25 +1,45 @@
 package policyv2
 
 import (
-	"encoding/json"
+	"net/netip"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
-	"github.com/tailscale/hujson"
+	"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    *ACLPolicy
+		want    *Policy
-		wantErr error
+		wantErr string
 	}{
 		{
 			name:  "empty",
 			input: "{}",
-			want:  &ACLPolicy{},
+			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",
@@ -29,67 +49,500 @@ func TestUnmarshalPolicy(t *testing.T) {
 		"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",
-			"src": [
+			"proto": "tcp",
-				"group:example",
+			"src": ["*"],
-			],
+			"dst": ["*:*"],
-			"dst": [
+		},
-				"host-1:*",
+		// 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: &ACLPolicy{
+			want: &Policy{
 				Groups: Groups{
-					Group("group:example"): []Username{"testuser@headscale.net"},
+					Group("group:example"): []Username{Username("testuser@headscale.net")},
+					Group("group:other"):   []Username{Username("otheruser@headscale.net")},
+				},
+				TagOwners: TagOwners{
+					Tag("tag:user"):         Owners{ptr.To(Username("testuser@headscale.net"))},
+					Tag("tag:group"):        Owners{Group("group:other")},
+					Tag("tag:userandgroup"): Owners{ptr.To(Username("testuser@headscale.net")), Group("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",
+						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).
+							Host("*"),
+						},
+						Destinations: []AliasWithPorts{
+							{
+								// TODO(kradalby): Should this be host?
+								// It is:
+								// Includes any destination (no restrictions).
+								Alias: Host("*"),
+								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{tailcfg.PortRange{First: 80, Last: 80}},
+							},
+						},
+					},
+					{
+						Action:   "accept",
+						Protocol: "tcp",
 						Sources: Aliases{
 							Group("group:example"),
 						},
+						Destinations: []AliasWithPorts{
+							{
+								Alias: Group("group:other"),
+								Ports: []tailcfg.PortRange{tailcfg.PortRange{First: 80, Last: 80}},
+							},
+						},
+					},
+					{
+						Action:   "accept",
+						Protocol: "tcp",
+						Sources: Aliases{
+							ptr.To(Prefix(netip.MustParsePrefix("100.101.102.103/32"))),
+						},
+						Destinations: []AliasWithPorts{
+							{
+								Alias: ptr.To(Prefix(netip.MustParsePrefix("100.101.102.104/32"))),
+								Ports: []tailcfg.PortRange{tailcfg.PortRange{First: 80, Last: 80}},
+							},
+						},
+					},
+					{
+						Action:   "accept",
+						Protocol: "udp",
+						Sources: Aliases{
+							ptr.To(Prefix(netip.MustParsePrefix("10.0.0.0/8"))),
+						},
+						Destinations: []AliasWithPorts{
+							{
+								Alias: ptr.To(Prefix(netip.MustParsePrefix("172.16.0.0/16"))),
+								Ports: []tailcfg.PortRange{tailcfg.PortRange{First: 80, Last: 80}},
+							},
+						},
+					},
+					{
+						Action:   "accept",
+						Protocol: "tcp",
+						Sources: Aliases{
+							Host("subnet-1"),
+						},
 						Destinations: []AliasWithPorts{
 							{
 								Alias: Host("host-1"),
-								Ports: []tailcfg.PortRange{tailcfg.PortRangeAny},
+								Ports: []tailcfg.PortRange{tailcfg.PortRange{First: 80, Last: 88}},
+							},
+						},
+					},
+					{
+						Action:   "accept",
+						Protocol: "tcp",
+						Sources: Aliases{
+							Tag("tag:group"),
+						},
+						Destinations: []AliasWithPorts{
+							{
+								Alias: Tag("tag:user"),
+								Ports: []tailcfg.PortRange{
+									tailcfg.PortRange{First: 80, Last: 80},
+									tailcfg.PortRange{First: 443, Last: 443},
+								},
+							},
+						},
+					},
+					{
+						Action:   "accept",
+						Protocol: "tcp",
+						Sources: Aliases{
+							Tag("tag:group"),
+						},
+						Destinations: []AliasWithPorts{
+							{
+								Alias: AutoGroup("autogroup:internet"),
+								Ports: []tailcfg.PortRange{
+									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) {
-			var policy ACLPolicy
+			policy, err := PolicyFromBytes([]byte(tt.input))
-			ast, err := hujson.Parse([]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("parsing hujson: %s", err)
+				t.Fatalf("unexpected err: %q", err)
 			}
 
-			ast.Standardize()
+			if diff := cmp.Diff(tt.want, &policy, cmps...); diff != "" {
-			acl := ast.Pack()
-
-			if err := json.Unmarshal(acl, &policy); err != nil {
-				// TODO: check error type
-				t.Fatalf("unmarshaling json: %s", err)
-			}
-
-			if diff := cmp.Diff(tt.want, &policy); diff != "" {
 				t.Fatalf("unexpected policy (-want +got):\n%s", diff)
 			}
 		})
 	}
 }
+
+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: Host("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: Tag("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, 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 +135,50 @@ func (node *Node) IPs() []netip.Addr {
 	return ret
 }
 
+// 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() {