feat(machine): add ACLFilter if ACL's are enabled.

This commit change the default behaviour and remove the notion of namespaces between the hosts. It allows all namespaces to be only filtered by the ACLs. This behavior is closer to tailsnet.

machine.go

@@ -119,14 +119,21 @@ func (machine Machine) isExpired() bool {
 	return time.Now().UTC().After(*machine.Expiry)
 }
 
-// Our Pineapple fork of Headscale ignores namespaces when dealing with peers
-// and instead passes ALL peers across all namespaces to each client. Access between clients
-// is then enforced with ACL policies.
-func (h *Headscale) getAllPeers(machine *Machine) (Machines, error) {
+func containsAddresses(inputs []string, addrs MachineAddresses) bool {
+	for _, addr := range addrs.ToStringSlice() {
+		if containsString(inputs, addr) {
+			return true
+		}
+	}
+	return false
+}
+
+// getFilteredByACLPeerss should return the list of peers authorized to be accessed from machine.
+func (h *Headscale) getFilteredByACLPeers(machine *Machine) (Machines, error) {
 	log.Trace().
 		Caller().
 		Str("machine", machine.Name).
-		Msg("Finding all peers")
+		Msg("Finding peers filtered by ACLs")
 
 	machines := Machines{}
 	if err := h.db.Preload("Namespace").Where("machine_key <> ? AND registered",
@@ -135,15 +142,50 @@ func (h *Headscale) getAllPeers(machine *Machine) (Machines, error) {
 
 		return Machines{}, err
 	}
+	mMachines := make(map[uint64]Machine)
 
-	sort.Slice(machines, func(i, j int) bool { return machines[i].ID < machines[j].ID })
+	// Aclfilter peers here. We are itering through machines in all namespaces and search through the computed aclRules
+	// for match between rule SrcIPs and DstPorts. If the rule is a match we allow the machine to be viewable.
+
+	// FIXME: On official control plane if a rule allow user A to talk to user B but NO rule allows user B to talk to
+	// user A. The behaviour is the following
+	//
+	// On official tailscale control plane:
+	//   on first `tailscale status`` on node A we can see node B. The `tailscale status` command on node B doesn't show node A
+	//   We can successfully establish a communication from A to B. When it's done, if we run the `tailscale status` command
+	//   on node B again we can now see node A. It's not possible to establish a communication from node B to node A.
+	// On this implementation of the feature
+	//   on any `tailscale status` command on node A we can see node B. The `tailscale status` command on node B DOES show A.
+	//
+	// I couldn't find a way to not clutter the output of `tailscale status` with all nodes that we could be talking to.
+	// In order to do this we would need to be able to identify that node A want to talk to node B but that Node B doesn't know
+	// how to talk to node A and then add the peering resource.
+
+	for _, m := range machines {
+		for _, rule := range h.aclRules {
+			var dst []string
+			for _, d := range rule.DstPorts {
+				dst = append(dst, d.IP)
+			}
+			if (containsAddresses(rule.SrcIPs, machine.IPAddresses) && (containsAddresses(dst, m.IPAddresses) || containsString(dst, "*"))) ||
+				(containsAddresses(rule.SrcIPs, m.IPAddresses) && containsAddresses(dst, machine.IPAddresses)) {
+				mMachines[m.ID] = m
+			}
+		}
+	}
+
+	var authorizedMachines Machines
+	for _, m := range mMachines {
+		authorizedMachines = append(authorizedMachines, m)
+	}
+	sort.Slice(authorizedMachines, func(i, j int) bool { return authorizedMachines[i].ID < authorizedMachines[j].ID })
 
 	log.Trace().
 		Caller().
 		Str("machine", machine.Name).
-		Msgf("Found all machines: %s", machines.String())
+		Msgf("Found some machines: %s", machines.String())
 
-	return machines, nil
+	return authorizedMachines, nil
 }
 
 func (h *Headscale) getDirectPeers(machine *Machine) (Machines, error) {
@@ -233,47 +275,52 @@ func (h *Headscale) getSharedTo(machine *Machine) (Machines, error) {
 }
 
 func (h *Headscale) getPeers(machine *Machine) (Machines, error) {
-	// direct, err := h.getDirectPeers(machine)
-	// if err != nil {
-	// 	log.Error().
-	// 		Caller().
-	// 		Err(err).
-	// 		Msg("Cannot fetch peers")
+	var peers Machines
+	var err error
+	// If ACLs rules are defined, filter visible host list with the ACLs
+	// else use the classic namespace scope
+	if h.aclPolicy != nil {
+		peers, err = h.getFilteredByACLPeers(machine)
+		if err != nil {
+			log.Error().
+				Caller().
+				Err(err).
+				Msg("Cannot fetch peers")
 
-	// 	return Machines{}, err
-	// }
+			return Machines{}, err
+		}
+	} else {
+		direct, err := h.getDirectPeers(machine)
+		if err != nil {
+			log.Error().
+				Caller().
+				Err(err).
+				Msg("Cannot fetch peers")
 
-	// shared, err := h.getShared(machine)
-	// if err != nil {
-	// 	log.Error().
-	// 		Caller().
-	// 		Err(err).
-	// 		Msg("Cannot fetch peers")
+			return Machines{}, err
+		}
 
-	// 	return Machines{}, err
-	// }
+		shared, err := h.getShared(machine)
+		if err != nil {
+			log.Error().
+				Caller().
+				Err(err).
+				Msg("Cannot fetch peers")
 
-	// sharedTo, err := h.getSharedTo(machine)
-	// if err != nil {
-	// 	log.Error().
-	// 		Caller().
-	// 		Err(err).
-	// 		Msg("Cannot fetch peers")
+			return Machines{}, err
+		}
 
-	// 	return Machines{}, err
-	// }
+		sharedTo, err := h.getSharedTo(machine)
+		if err != nil {
+			log.Error().
+				Caller().
+				Err(err).
+				Msg("Cannot fetch peers")
 
-	// peers := append(direct, shared...)
-	// peers = append(peers, sharedTo...)
-
-	peers, err := h.getAllPeers(machine)
-	if err != nil {
-		log.Error().
-			Caller().
-			Err(err).
-			Msg("Cannot fetch peers")
-
-		return Machines{}, err
+			return Machines{}, err
+		}
+		peers = append(direct, shared...)
+		peers = append(peers, sharedTo...)
 	}
 
 	sort.Slice(peers, func(i, j int) bool { return peers[i].ID < peers[j].ID })

machine_test.go

@@ -1,6 +1,7 @@
 package headscale
 
 import (
+	"fmt"
 	"strconv"
 	"time"
 
@@ -154,6 +155,89 @@ func (s *Suite) TestGetDirectPeers(c *check.C) {
 	c.Assert(peersOfMachine0[8].Name, check.Equals, "testmachine10")
 }
 
+func (s *Suite) TestGetACLFilteredPeers(c *check.C) {
+	type base struct {
+		namespace *Namespace
+		key       *PreAuthKey
+	}
+
+	var stor []base
+
+	for _, name := range []string{"test", "admin"} {
+		namespace, err := app.CreateNamespace(name)
+		c.Assert(err, check.IsNil)
+		pak, err := app.CreatePreAuthKey(namespace.Name, false, false, nil)
+		c.Assert(err, check.IsNil)
+		stor = append(stor, base{namespace, pak})
+
+	}
+
+	_, err := app.GetMachineByID(0)
+	c.Assert(err, check.NotNil)
+
+	for index := 0; index <= 10; index++ {
+		machine := Machine{
+			ID:             uint64(index),
+			MachineKey:     "foo" + strconv.Itoa(index),
+			NodeKey:        "bar" + strconv.Itoa(index),
+			DiscoKey:       "faa" + strconv.Itoa(index),
+			IPAddress:      fmt.Sprintf("100.64.0.%v", strconv.Itoa(index+1)),
+			Name:           "testmachine" + strconv.Itoa(index),
+			NamespaceID:    stor[index%2].namespace.ID,
+			Registered:     true,
+			RegisterMethod: RegisterMethodAuthKey,
+			AuthKeyID:      uint(stor[index%2].key.ID),
+		}
+		app.db.Save(&machine)
+	}
+
+	app.aclPolicy = &ACLPolicy{
+		Groups: map[string][]string{
+			"group:test": {"admin"},
+		},
+		Hosts:     map[string]netaddr.IPPrefix{},
+		TagOwners: map[string][]string{},
+		ACLs: []ACL{
+			{Action: "accept", Users: []string{"admin"}, Ports: []string{"*:*"}},
+			{Action: "accept", Users: []string{"test"}, Ports: []string{"test:*"}},
+		},
+		Tests: []ACLTest{},
+	}
+
+	rules, err := app.generateACLRules()
+	c.Assert(err, check.IsNil)
+	app.aclRules = rules
+
+	adminMachine, err := app.GetMachineByID(1)
+	c.Logf("Machine(%v), namespace: %v", adminMachine.Name, adminMachine.Namespace)
+	c.Assert(err, check.IsNil)
+
+	testMachine, err := app.GetMachineByID(2)
+	c.Logf("Machine(%v), namespace: %v", testMachine.Name, testMachine.Namespace)
+	c.Assert(err, check.IsNil)
+
+	_, err = testMachine.GetHostInfo()
+	c.Assert(err, check.IsNil)
+
+	peersOfTestMachine, err := app.getFilteredByACLPeers(testMachine)
+	c.Assert(err, check.IsNil)
+
+	peersOfAdminMachine, err := app.getFilteredByACLPeers(adminMachine)
+	c.Assert(err, check.IsNil)
+
+	c.Log(peersOfTestMachine)
+	c.Assert(len(peersOfTestMachine), check.Equals, 4)
+	c.Assert(peersOfTestMachine[0].Name, check.Equals, "testmachine4")
+	c.Assert(peersOfTestMachine[1].Name, check.Equals, "testmachine6")
+	c.Assert(peersOfTestMachine[3].Name, check.Equals, "testmachine10")
+
+	c.Log(peersOfAdminMachine)
+	c.Assert(len(peersOfAdminMachine), check.Equals, 9)
+	c.Assert(peersOfAdminMachine[0].Name, check.Equals, "testmachine2")
+	c.Assert(peersOfAdminMachine[2].Name, check.Equals, "testmachine4")
+	c.Assert(peersOfAdminMachine[5].Name, check.Equals, "testmachine7")
+}
+
 func (s *Suite) TestExpireMachine(c *check.C) {
 	namespace, err := app.CreateNamespace("test")
 	c.Assert(err, check.IsNil)

utils.go

@@ -212,6 +212,15 @@ func (h *Headscale) getUsedIPs() ([]netaddr.IP, error) {
 	return ips, nil
 }
 
+func containsString(ss []string, s string) bool {
+	for _, v := range ss {
+		if v == s {
+			return true
+		}
+	}
+	return false
+}
+
 func containsIPs(ips []netaddr.IP, ip netaddr.IP) bool {
 	for _, v := range ips {
 		if v == ip {