Merge remote-tracking branch 'origin/main' into dmitri-event-aggregation

2026-07-17 12:09:58 +00:00 · 2026-06-15 10:50:14 +02:00
parent c875aa6b4b b19467e3af
commit fae5b7e007
41 changed files with 3677 additions and 288 deletions
--- a/client/internal/debug/debug.go
+++ b/client/internal/debug/debug.go
@@ -516,6 +516,14 @@ func (g *BundleGenerator) addConfig() error {
 		}
 	}

+	// Surface the set of MDM-enforced keys so a support engineer reading
+	// the bundle can tell which field values are user-set vs MDM-overridden.
+	// Same semantics as the mDMManagedFields list returned by the
+	// GetConfig RPC consumed by `netbird debug config`.
+	if managed := g.internalConfig.Policy().ManagedKeys(); len(managed) > 0 {
+		configContent.WriteString(fmt.Sprintf("MDMManagedFields: %v\n", managed))
+	}
+
 	configReader := strings.NewReader(configContent.String())
 	if err := g.addFileToZip(configReader, "config.txt"); err != nil {
 		return fmt.Errorf("add config file to zip: %w", err)
--- a/client/internal/debug/debug_test.go
+++ b/client/internal/debug/debug_test.go
@@ -843,6 +843,7 @@ func TestAddConfig_AllFieldsCovered(t *testing.T) {
 		"PreSharedKey":      "sensitive: WireGuard pre-shared key",
 		"SSHKey":            "sensitive: SSH private key",
 		"ClientCertKeyPair": "non-config: parsed cert pair, not serialized",
+		"policy":            "non-config: in-memory MDM policy snapshot, surfaced via Config.Policy() / GetConfigResponse.MDMManagedFields",
 	}

 	mURL, _ := url.Parse("https://api.example.com:443")
--- a/client/internal/dns/local/local.go
+++ b/client/internal/dns/local/local.go
@@ -482,7 +482,7 @@ func (d *Resolver) logDNSError(logger *log.Entry, hostname string, qtype uint16,
 // completely when every proxy peer is offline (the upstream may still
 // be reachable some other way, or the peerstore may be stale).
 func (d *Resolver) filterDisconnectedPeerAnswers(logger *log.Entry, question dns.Question, records []dns.RR) []dns.RR {
-	if len(records) == 0 {
+	if len(records) < 2 {
 		return records
 	}
 	d.mu.RLock()
--- a/client/internal/dns/local/local_test.go
+++ b/client/internal/dns/local/local_test.go
@@ -2738,6 +2738,17 @@ func TestLocalResolver_FilterDisconnectedPeerAnswers(t *testing.T) {
 			connByIP:    nil,
 			wantInOrder: []string{"100.64.0.10", "100.64.0.11"},
 		},
+		{
+			// A single answer is never filtered: dropping it would only
+			// trigger the empty-answer escape hatch, so the fast path
+			// returns it untouched.
+			name:    "single disconnected answer passes through",
+			records: []nbdns.SimpleRecord{disconnectedRec},
+			connByIP: map[string]ipState{
+				"100.64.0.11": {known: true, connected: false},
+			},
+			wantInOrder: []string{"100.64.0.11"},
+		},
 	}

 	for _, tc := range tests {
--- a/client/internal/dns/resutil/resolve.go
+++ b/client/internal/dns/resutil/resolve.go
@@ -14,6 +14,10 @@ import (
 	log "github.com/sirupsen/logrus"
 )

+// errNoSuitableAddress mirrors the unexported error string the net package
+// uses when a resolved host has no addresses of the requested family.
+const errNoSuitableAddress = "no suitable address found"
+
 // GenerateRequestID creates a random 8-character hex string for request tracing.
 func GenerateRequestID() string {
 	bytes := make([]byte, 4)
@@ -126,6 +130,14 @@ func LookupIP(ctx context.Context, r resolver, network, host string, qtype uint1
 }

 func getRcodeForError(ctx context.Context, r resolver, host string, qtype uint16, err error) int {
+	// The net package returns this AddrError when the host resolves but has
+	// no addresses of the requested family. The domain exists, so answer
+	// NODATA instead of SERVFAIL.
+	var addrErr *net.AddrError
+	if errors.As(err, &addrErr) && addrErr.Err == errNoSuitableAddress {
+		return dns.RcodeSuccess
+	}
+
 	var dnsErr *net.DNSError
 	if !errors.As(err, &dnsErr) {
 		return dns.RcodeServerFailure
--- a/client/internal/dns/resutil/resolve_test.go
+++ b/client/internal/dns/resutil/resolve_test.go
@@ -0,0 +1,122 @@
+package resutil
+
+import (
+	"context"
+	"errors"
+	"net"
+	"net/netip"
+	"testing"
+
+	"github.com/miekg/dns"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+type mockResolver struct {
+	// results maps network ("ip4"/"ip6") to the lookup outcome.
+	results map[string]mockLookup
+}
+
+type mockLookup struct {
+	ips []netip.Addr
+	err error
+}
+
+func (m *mockResolver) LookupNetIP(_ context.Context, network, _ string) ([]netip.Addr, error) {
+	res, ok := m.results[network]
+	if !ok {
+		return nil, errors.New("unexpected network: " + network)
+	}
+	return res.ips, res.err
+}
+
+func TestLookupIP_Success(t *testing.T) {
+	r := &mockResolver{results: map[string]mockLookup{
+		"ip4": {ips: []netip.Addr{netip.MustParseAddr("::ffff:192.0.2.1")}},
+	}}
+
+	result := LookupIP(context.Background(), r, "ip4", "example.com.", dns.TypeA)
+
+	assert.Equal(t, dns.RcodeSuccess, result.Rcode, "successful lookup should return NOERROR")
+	require.Len(t, result.IPs, 1, "should return the resolved address")
+	assert.Equal(t, netip.MustParseAddr("192.0.2.1"), result.IPs[0], "v4-mapped address should be unmapped")
+}
+
+func TestLookupIP_NoSuitableAddress(t *testing.T) {
+	// The net package returns this AddrError when the host resolves but has
+	// no addresses of the requested family (e.g. AAAA query for a v4-only
+	// hosts file entry). The domain exists, so this is NODATA, not SERVFAIL.
+	r := &mockResolver{results: map[string]mockLookup{
+		"ip6": {err: &net.AddrError{Err: "no suitable address found", Addr: "example.com."}},
+	}}
+
+	result := LookupIP(context.Background(), r, "ip6", "example.com.", dns.TypeAAAA)
+
+	assert.Equal(t, dns.RcodeSuccess, result.Rcode, "no suitable address should map to NODATA")
+	assert.Empty(t, result.IPs, "NODATA response should carry no addresses")
+}
+
+// TestErrNoSuitableAddressMatchesNetPackage pins our copy of the error string
+// to what the net package actually emits. A literal IP of the wrong family
+// takes the same filterAddrList path as a resolved hostname, without network
+// access.
+func TestErrNoSuitableAddressMatchesNetPackage(t *testing.T) {
+	_, err := (&net.Resolver{}).LookupNetIP(context.Background(), "ip6", "192.0.2.1")
+	require.Error(t, err)
+
+	var addrErr *net.AddrError
+	require.ErrorAs(t, err, &addrErr, "wrong-family lookup should return AddrError")
+	assert.Equal(t, errNoSuitableAddress, addrErr.Err, "net package error string should match our constant")
+}
+
+func TestLookupIP_OtherAddrError(t *testing.T) {
+	r := &mockResolver{results: map[string]mockLookup{
+		"ip4": {err: &net.AddrError{Err: "some other address problem", Addr: "example.com."}},
+	}}
+
+	result := LookupIP(context.Background(), r, "ip4", "example.com.", dns.TypeA)
+
+	assert.Equal(t, dns.RcodeServerFailure, result.Rcode, "unrecognized AddrError should map to SERVFAIL")
+}
+
+func TestLookupIP_NotFoundNXDomain(t *testing.T) {
+	r := &mockResolver{results: map[string]mockLookup{
+		"ip4": {err: &net.DNSError{Err: "no such host", Name: "example.com.", IsNotFound: true}},
+		"ip6": {err: &net.DNSError{Err: "no such host", Name: "example.com.", IsNotFound: true}},
+	}}
+
+	result := LookupIP(context.Background(), r, "ip4", "example.com.", dns.TypeA)
+
+	assert.Equal(t, dns.RcodeNameError, result.Rcode, "not found for both families should map to NXDOMAIN")
+}
+
+func TestLookupIP_NotFoundNoData(t *testing.T) {
+	r := &mockResolver{results: map[string]mockLookup{
+		"ip6": {err: &net.DNSError{Err: "no such host", Name: "example.com.", IsNotFound: true}},
+		"ip4": {ips: []netip.Addr{netip.MustParseAddr("192.0.2.1")}},
+	}}
+
+	result := LookupIP(context.Background(), r, "ip6", "example.com.", dns.TypeAAAA)
+
+	assert.Equal(t, dns.RcodeSuccess, result.Rcode, "not found with the other family present should map to NODATA")
+}
+
+func TestLookupIP_GenericError(t *testing.T) {
+	r := &mockResolver{results: map[string]mockLookup{
+		"ip4": {err: errors.New("connection refused")},
+	}}
+
+	result := LookupIP(context.Background(), r, "ip4", "example.com.", dns.TypeA)
+
+	assert.Equal(t, dns.RcodeServerFailure, result.Rcode, "generic error should map to SERVFAIL")
+}
+
+func TestLookupIP_DNSErrorNotIsNotFound(t *testing.T) {
+	r := &mockResolver{results: map[string]mockLookup{
+		"ip4": {err: &net.DNSError{Err: "server misbehaving", Name: "example.com.", IsTemporary: true}},
+	}}
+
+	result := LookupIP(context.Background(), r, "ip4", "example.com.", dns.TypeA)
+
+	assert.Equal(t, dns.RcodeServerFailure, result.Rcode, "upstream failure should map to SERVFAIL")
+}
--- a/client/internal/peer/conn_status.go
+++ b/client/internal/peer/conn_status.go
@@ -26,7 +26,6 @@ type connStatusInputs struct {
 	iceInProgress       bool // a negotiation is currently in flight
 }

-
 // ConnStatus describe the status of a peer's connection
 type ConnStatus int32

--- a/client/internal/peer/status.go
+++ b/client/internal/peer/status.go
@@ -193,6 +193,7 @@ func (s *StatusChangeSubscription) Events() chan map[string]RouterState {
 type Status struct {
 	mux                   sync.RWMutex
 	peers                 map[string]State
+	ipToKey               map[string]string
 	changeNotify          map[string]map[string]*StatusChangeSubscription // map[peerID]map[subscriptionID]*StatusChangeSubscription
 	signalState           bool
 	signalError           error
@@ -231,6 +232,7 @@ type Status struct {
 func NewRecorder(mgmAddress string) *Status {
 	return &Status{
 		peers:                 make(map[string]State),
+		ipToKey:               make(map[string]string),
 		changeNotify:          make(map[string]map[string]*StatusChangeSubscription),
 		eventStreams:          make(map[string]chan *proto.SystemEvent),
 		eventQueue:            NewEventQueue(eventQueueSize),
@@ -282,6 +284,12 @@ func (d *Status) AddPeer(peerPubKey string, fqdn string, ip string, ipv6 string)
 		Mux:        new(sync.RWMutex),
 	}
 	d.peerListChangedForNotification = true
+	if ipv6 != "" {
+		d.ipToKey[ipv6] = peerPubKey
+	}
+	if ip != "" {
+		d.ipToKey[ip] = peerPubKey
+	}
 	return nil
 }

@@ -311,28 +319,22 @@ func (d *Status) PeerByIP(ip string) (string, bool) {

 // PeerStateByIP returns the full peer State for the given tunnel IP.
 // Matches against either the IPv4 (State.IP) or IPv6 (State.IPv6) tunnel
-// address so dual-stack peers are reachable on either family. Searches
-// both d.peers and d.offlinePeers — peers that have been moved into
-// the offline slice by ReplaceOfflinePeers are still part of the
-// account's roster and callers (DNS filter, embed.Client.IdentityForIP)
-// need to recognise them rather than treating them as unknown. Returns
-// the zero State and false when no peer matches or the input is empty.
+// address so dual-stack peers are reachable on either family. Only
+// active peers are matched; peers moved into the offline slice by
+// ReplaceOfflinePeers are intentionally treated as unknown.
 func (d *Status) PeerStateByIP(ip string) (State, bool) {
 	if ip == "" {
 		return State{}, false
 	}
 	d.mux.RLock()
 	defer d.mux.RUnlock()
-
-	for _, state := range d.peers {
-		if (state.IP != "" && state.IP == ip) || (state.IPv6 != "" && state.IPv6 == ip) {
-			return state, true
-		}
+	key, ok := d.ipToKey[ip]
+	if !ok {
+		return State{}, false
 	}
-	for _, state := range d.offlinePeers {
-		if (state.IP != "" && state.IP == ip) || (state.IPv6 != "" && state.IPv6 == ip) {
-			return state, true
-		}
+	state, ok := d.peers[key]
+	if ok {
+		return state, true
 	}
 	return State{}, false
 }
@@ -342,12 +344,18 @@ func (d *Status) RemovePeer(peerPubKey string) error {
 	d.mux.Lock()
 	defer d.mux.Unlock()

-	_, ok := d.peers[peerPubKey]
+	p, ok := d.peers[peerPubKey]
 	if !ok {
 		return errors.New("no peer with to remove")
 	}

 	delete(d.peers, peerPubKey)
+	if mappedKey, exists := d.ipToKey[p.IP]; exists && mappedKey == peerPubKey {
+		delete(d.ipToKey, p.IP)
+	}
+	if mappedKey, exists := d.ipToKey[p.IPv6]; exists && mappedKey == peerPubKey {
+		delete(d.ipToKey, p.IPv6)
+	}
 	d.peerListChangedForNotification = true
 	return nil
 }
--- a/client/internal/peer/status_test.go
+++ b/client/internal/peer/status_test.go
@@ -90,12 +90,11 @@ func TestStatus_PeerStateByIP_MatchesIPv6(t *testing.T) {
 	req.Equal("pk-1", state.PubKey, "matching state must carry the right pub key")
 }

-// TestStatus_PeerStateByIP_MatchesOfflinePeers covers peers that have
-// been moved into the offline slice via ReplaceOfflinePeers. Callers
-// (DNS filter, embed.Client.IdentityForIP) need to treat them as known
-// rather than unknown — otherwise authentication / DNS filtering treats
-// known-but-offline peers as foreign IPs.
-func TestStatus_PeerStateByIP_MatchesOfflinePeers(t *testing.T) {
+// TestStatus_PeerStateByIP_IgnoresOfflinePeers documents that peers
+// moved into the offline slice via ReplaceOfflinePeers are intentionally
+// not resolvable by IP: only active peers can carry traffic, so callers
+// (DNS filter, embed.Client.IdentityForIP) treat them as unknown.
+func TestStatus_PeerStateByIP_IgnoresOfflinePeers(t *testing.T) {
 	status := NewRecorder("https://mgm")
 	req := require.New(t)

@@ -103,13 +102,31 @@ func TestStatus_PeerStateByIP_MatchesOfflinePeers(t *testing.T) {
 		{PubKey: "pk-offline", FQDN: "offline.netbird", IP: "100.64.0.20", IPv6: "fd00::20"},
 	})

-	state, ok := status.PeerStateByIP("100.64.0.20")
-	req.True(ok, "offline peer must resolve by IPv4 tunnel address")
-	req.Equal("pk-offline", state.PubKey, "matching state must carry the offline peer's pub key")
+	_, ok := status.PeerStateByIP("100.64.0.20")
+	req.False(ok, "offline peer must not resolve by IPv4 tunnel address")

-	state, ok = status.PeerStateByIP("fd00::20")
-	req.True(ok, "offline peer must resolve by IPv6 tunnel address")
-	req.Equal("pk-offline", state.PubKey, "IPv6 match must carry the offline peer's pub key")
+	_, ok = status.PeerStateByIP("fd00::20")
+	req.False(ok, "offline peer must not resolve by IPv6 tunnel address")
+}
+
+// TestStatus_PeerStateByIP_RemovedPeer verifies RemovePeer drops the
+// IP index entries for both address families.
+func TestStatus_PeerStateByIP_RemovedPeer(t *testing.T) {
+	status := NewRecorder("https://mgm")
+	req := require.New(t)
+
+	req.NoError(status.AddPeer("pk-1", "peer-1.netbird", "100.64.0.10", "fd00::1"))
+
+	_, ok := status.PeerStateByIP("100.64.0.10")
+	req.True(ok, "active peer must resolve before removal")
+
+	req.NoError(status.RemovePeer("pk-1"))
+
+	_, ok = status.PeerStateByIP("100.64.0.10")
+	req.False(ok, "removed peer must not resolve by IPv4 tunnel address")
+
+	_, ok = status.PeerStateByIP("fd00::1")
+	req.False(ok, "removed peer must not resolve by IPv6 tunnel address")
 }

 func TestStatus_UpdatePeerFQDN(t *testing.T) {
--- a/client/internal/profilemanager/config.go
+++ b/client/internal/profilemanager/config.go
@@ -22,6 +22,7 @@ import (

 	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/internal/routemanager/dynamic"
+	"github.com/netbirdio/netbird/client/mdm"
 	"github.com/netbirdio/netbird/client/ssh"
 	mgm "github.com/netbirdio/netbird/shared/management/client"
 	"github.com/netbirdio/netbird/shared/management/domain"
@@ -57,6 +58,10 @@ var DefaultInterfaceBlacklist = []string{
 	"Tailscale", "tailscale", "docker", "veth", "br-", "lo",
 }

+// loadMDMPolicy is the package-level indirection used by apply() to read the
+// active MDM policy. Tests override this to inject a fake policy.
+var loadMDMPolicy = mdm.LoadPolicy
+
 // ConfigInput carries configuration changes to the client
 type ConfigInput struct {
 	ManagementURL                 string
@@ -174,6 +179,23 @@ type Config struct {
 	LazyConnectionEnabled bool

 	MTU uint16
+
+	// policy is the MDM policy that produced the currently-set values for
+	// any MDM-enforced fields. Set by applyMDMPolicy at the tail of apply()
+	// and reset on every apply() invocation. Never persisted to disk.
+	// Callers query enforcement state via Policy() and the mdm.Policy API
+	// (HasKey, ManagedKeys, IsEmpty).
+	policy *mdm.Policy `json:"-"`
+}
+
+// Policy returns the MDM policy applied to this Config. Returns a non-nil
+// empty Policy when MDM enforcement is inactive; callers can always invoke
+// HasKey / ManagedKeys / IsEmpty without a nil check.
+func (config *Config) Policy() *mdm.Policy {
+	if config == nil || config.policy == nil {
+		return mdm.NewPolicy(nil)
+	}
+	return config.policy
 }

 var ConfigDirOverride string
@@ -612,10 +634,93 @@ func (config *Config) apply(input ConfigInput) (updated bool, err error) {
 		updated = true
 	}

+	// MDM is the last override layer: any key present in the policy
+	// supersedes defaults, on-disk config, env vars and CLI input.
+	config.applyMDMPolicy(loadMDMPolicy())
+
 	return updated, nil
 }

-// parseURL parses and validates a service URL
+// applyMDMPolicy overlays MDM-supplied values on top of the resolved Config.
+// The provided Policy is also stored on the Config so callers can later query
+// which fields are enforced. Invalid values (e.g. malformed URLs) are logged
+// and skipped to avoid bricking the client; the field keeps its previous
+// resolved value but is still marked as managed (Policy.HasKey returns true
+// for the key, so per-field rejection of user writes still applies).
+func (config *Config) applyMDMPolicy(policy *mdm.Policy) {
+	config.policy = policy
+	if policy.IsEmpty() {
+		return
+	}
+
+	// Helper: log the application of a single MDM-managed key. Values for
+	// keys in mdm.SecretKeys are redacted.
+	logApplied := func(key string, displayValue any) {
+		if _, secret := mdm.SecretKeys[key]; secret {
+			log.Infof("MDM override %s = ********** (secret)", key)
+			return
+		}
+		log.Infof("MDM override %s = %v", key, displayValue)
+	}
+
+	if v, ok := policy.GetString(mdm.KeyManagementURL); ok {
+		if u, err := parseURL("Management URL", v); err != nil {
+			log.Warnf("MDM management URL %q invalid: %v; keeping previous value", v, err)
+		} else {
+			config.ManagementURL = u
+			logApplied(mdm.KeyManagementURL, u.String())
+		}
+	}
+
+	if v, ok := policy.GetString(mdm.KeyPreSharedKey); ok {
+		// Defensive: refuse the redaction mask in case it round-tripped
+		// through a manifest by mistake.
+		if !isPreSharedKeyHidden(&v) {
+			config.PreSharedKey = v
+			logApplied(mdm.KeyPreSharedKey, "")
+		}
+	}
+
+	// applyBool collapses the per-key "read + set + log" boilerplate
+	// for every plain bool MDM key into a single helper. Keeps the
+	// outer function's cognitive complexity below SonarCube's
+	// threshold; functional behaviour is identical to the inlined
+	// branches it replaces.
+	applyBool := func(key string, setter func(bool)) {
+		v, ok := policy.GetBool(key)
+		if !ok {
+			return
+		}
+		setter(v)
+		logApplied(key, v)
+	}
+
+	applyBool(mdm.KeyAllowServerSSH, func(v bool) { bv := v; config.ServerSSHAllowed = &bv })
+	applyBool(mdm.KeyDisableClientRoutes, func(v bool) { config.DisableClientRoutes = v })
+	applyBool(mdm.KeyDisableServerRoutes, func(v bool) { config.DisableServerRoutes = v })
+	applyBool(mdm.KeyBlockInbound, func(v bool) { config.BlockInbound = v })
+	applyBool(mdm.KeyDisableAutoConnect, func(v bool) { config.DisableAutoConnect = v })
+	applyBool(mdm.KeyRosenpassEnabled, func(v bool) { config.RosenpassEnabled = v })
+	applyBool(mdm.KeyRosenpassPermissive, func(v bool) { config.RosenpassPermissive = v })
+
+	if v, ok := policy.GetInt(mdm.KeyWireguardPort); ok {
+		// REG_DWORD is 32-bit; UDP port range is 1-65535. Clamp at the
+		// upper bound and reject obviously-invalid values to avoid the
+		// engine binding to an unusable port if the admin pushes garbage.
+		if v >= 1 && v <= 65535 {
+			config.WgPort = int(v)
+			logApplied(mdm.KeyWireguardPort, v)
+		} else {
+			log.Warnf("MDM wireguard port %d out of range [1,65535]; keeping previous value", v)
+		}
+	}
+}
+
+// parseURL parses and validates the URL for the named service. The URL
+// must use the http or https scheme; if no port is present, ":443" is
+// appended for https or ":80" for http. The serviceName parameter is
+// used to contextualise error messages. On success returns the parsed
+// *url.URL; on failure returns a non-nil error.
 func parseURL(serviceName, serviceURL string) (*url.URL, error) {
 	parsedMgmtURL, err := url.ParseRequestURI(serviceURL)
 	if err != nil {
--- a/client/internal/profilemanager/config_mdm_test.go
+++ b/client/internal/profilemanager/config_mdm_test.go
@@ -0,0 +1,152 @@
+package profilemanager
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/mdm"
+)
+
+// withMDMPolicy temporarily overrides the package-level loadMDMPolicy hook so
+// apply() observes the supplied Policy. The original loader is restored at
+// test cleanup.
+func withMDMPolicy(t *testing.T, policy *mdm.Policy) {
+	t.Helper()
+	prev := loadMDMPolicy
+	loadMDMPolicy = func() *mdm.Policy { return policy }
+	t.Cleanup(func() { loadMDMPolicy = prev })
+}
+
+func TestApply_MDMEmpty_NoEnforcement(t *testing.T) {
+	withMDMPolicy(t, mdm.NewPolicy(nil))
+
+	cfg, err := UpdateOrCreateConfig(ConfigInput{
+		ConfigPath: filepath.Join(t.TempDir(), "config.json"),
+	})
+	require.NoError(t, err)
+	require.NotNil(t, cfg)
+
+	assert.True(t, cfg.Policy().IsEmpty(), "no MDM source ⇒ empty Policy")
+	assert.False(t, cfg.Policy().HasKey(mdm.KeyManagementURL))
+	assert.Empty(t, cfg.Policy().ManagedKeys())
+
+	// Default management URL still resolves.
+	assert.Equal(t, DefaultManagementURL, cfg.ManagementURL.String())
+}
+
+func TestApply_MDMOnly_OverridesDefaults(t *testing.T) {
+	const mdmURL = "https://corp.mdm.example.com:443"
+	withMDMPolicy(t, mdm.NewPolicy(map[string]any{
+		mdm.KeyManagementURL:       mdmURL,
+		mdm.KeyDisableClientRoutes: true,
+		mdm.KeyBlockInbound:        true,
+	}))
+
+	cfg, err := UpdateOrCreateConfig(ConfigInput{
+		ConfigPath: filepath.Join(t.TempDir(), "config.json"),
+	})
+	require.NoError(t, err)
+	require.NotNil(t, cfg)
+
+	assert.Equal(t, mdmURL, cfg.ManagementURL.String())
+	assert.True(t, cfg.DisableClientRoutes)
+	assert.True(t, cfg.BlockInbound)
+
+	assert.True(t, cfg.Policy().HasKey(mdm.KeyManagementURL))
+	assert.True(t, cfg.Policy().HasKey(mdm.KeyDisableClientRoutes))
+	assert.True(t, cfg.Policy().HasKey(mdm.KeyBlockInbound))
+	assert.False(t, cfg.Policy().HasKey(mdm.KeyAllowServerSSH))
+}
+
+func TestApply_MDMBeatsCLIInput(t *testing.T) {
+	const mdmURL = "https://mdm.example.com:443"
+	const cliURL = "https://cli.example.com:443"
+
+	withMDMPolicy(t, mdm.NewPolicy(map[string]any{
+		mdm.KeyManagementURL: mdmURL,
+	}))
+
+	cfg, err := UpdateOrCreateConfig(ConfigInput{
+		ConfigPath:    filepath.Join(t.TempDir(), "config.json"),
+		ManagementURL: cliURL,
+	})
+	require.NoError(t, err)
+	require.NotNil(t, cfg)
+
+	// MDM wins over CLI-supplied management URL.
+	assert.Equal(t, mdmURL, cfg.ManagementURL.String())
+	assert.True(t, cfg.Policy().HasKey(mdm.KeyManagementURL))
+}
+
+func TestApply_MDMInvalidURL_KeepsPreviousValue(t *testing.T) {
+	withMDMPolicy(t, mdm.NewPolicy(map[string]any{
+		mdm.KeyManagementURL: "not-a-url",
+	}))
+
+	cfg, err := UpdateOrCreateConfig(ConfigInput{
+		ConfigPath: filepath.Join(t.TempDir(), "config.json"),
+	})
+	require.NoError(t, err)
+	require.NotNil(t, cfg)
+
+	// Invalid MDM URL is logged and skipped: default URL stays in place
+	// to keep the client functional.
+	assert.Equal(t, DefaultManagementURL, cfg.ManagementURL.String())
+
+	// But the key is still considered MDM-managed (admin intent is to
+	// enforce, daemon rejects user writes to this field — phase-1 scaffolding
+	// reflects this by keeping Policy.HasKey true even on parse failure).
+	assert.True(t, cfg.Policy().HasKey(mdm.KeyManagementURL))
+}
+
+func TestApply_MDMBoolKeysOverrideOnDiskValue(t *testing.T) {
+	tmp := filepath.Join(t.TempDir(), "config.json")
+
+	// Seed without MDM.
+	withMDMPolicy(t, mdm.NewPolicy(nil))
+	_, err := UpdateOrCreateConfig(ConfigInput{
+		ConfigPath:          tmp,
+		DisableClientRoutes: boolPtr(false),
+		RosenpassEnabled:    boolPtr(false),
+	})
+	require.NoError(t, err)
+
+	// Now enable MDM enforcement for these keys.
+	withMDMPolicy(t, mdm.NewPolicy(map[string]any{
+		mdm.KeyDisableClientRoutes: true,
+		mdm.KeyRosenpassEnabled:    true,
+	}))
+
+	cfg, err := UpdateOrCreateConfig(ConfigInput{ConfigPath: tmp})
+	require.NoError(t, err)
+	require.NotNil(t, cfg)
+
+	assert.True(t, cfg.DisableClientRoutes, "MDM override should flip on-disk false to true")
+	assert.True(t, cfg.RosenpassEnabled)
+	assert.True(t, cfg.Policy().HasKey(mdm.KeyDisableClientRoutes))
+	assert.True(t, cfg.Policy().HasKey(mdm.KeyRosenpassEnabled))
+}
+
+func TestApply_MDMPreSharedKeyRedactionSentinelRejected(t *testing.T) {
+	const maskSentinel = "**********"
+
+	withMDMPolicy(t, mdm.NewPolicy(map[string]any{
+		mdm.KeyPreSharedKey: maskSentinel,
+	}))
+
+	cfg, err := UpdateOrCreateConfig(ConfigInput{
+		ConfigPath: filepath.Join(t.TempDir(), "config.json"),
+	})
+	require.NoError(t, err)
+	require.NotNil(t, cfg)
+
+	// Mask sentinel must not be persisted as the actual PSK.
+	assert.NotEqual(t, maskSentinel, cfg.PreSharedKey)
+	// Key still marked managed so user writes are still rejected.
+	assert.True(t, cfg.Policy().HasKey(mdm.KeyPreSharedKey))
+}
+
+func boolPtr(b bool) *bool { return &b }