cmd/tailscale,ipn: surface TKA-filtered peers in lock status command

Signed-off-by: Tom DNetto <tom@tailscale.com>

cmd/tailscale/cli/network-lock.go

@@ -213,6 +213,26 @@ func runNetworkLockStatus(ctx context.Context, args []string) error {
 		}
 	}
 
+	if st.Enabled && len(st.FilteredPeers) > 0 {
+		fmt.Println()
+		fmt.Println("The following peers are locked out by tailnet lock & do not have connectivity:")
+		for _, p := range st.FilteredPeers {
+			var line strings.Builder
+			line.WriteString("\t")
+			line.WriteString(p.Name)
+			line.WriteString("\t")
+			for i, addr := range p.TailscaleIPs {
+				line.WriteString(addr.String())
+				if i < len(p.TailscaleIPs)-1 {
+					line.WriteString(", ")
+				}
+			}
+			line.WriteString("\t")
+			line.WriteString(string(p.StableID))
+			fmt.Println(line.String())
+		}
+	}
+
 	return nil
 }
 

ipn/ipnlocal/network-lock.go

@@ -14,6 +14,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"net/netip"
 	"os"
 	"path/filepath"
 	"time"
@@ -21,6 +22,7 @@ import (
 	"tailscale.com/envknob"
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/ipnstate"
+	"tailscale.com/net/tsaddr"
 	"tailscale.com/tailcfg"
 	"tailscale.com/tka"
 	"tailscale.com/types/key"
@@ -41,6 +43,7 @@ type tkaState struct {
 	profile   ipn.ProfileID
 	authority *tka.Authority
 	storage   *tka.FS
+	filtered  []ipnstate.TKAFilteredPeer
 }
 
 // tkaFilterNetmapLocked checks the signatures on each node key, dropping
@@ -75,12 +78,30 @@ func (b *LocalBackend) tkaFilterNetmapLocked(nm *netmap.NetworkMap) {
 	// nm.Peers is ordered, so deletion must be order-preserving.
 	if len(toDelete) > 0 {
 		peers := make([]*tailcfg.Node, 0, len(nm.Peers))
+		filtered := make([]ipnstate.TKAFilteredPeer, 0, len(toDelete))
 		for i, p := range nm.Peers {
 			if !toDelete[i] {
 				peers = append(peers, p)
+			} else {
+				// Record information about the node we filtered out.
+				fp := ipnstate.TKAFilteredPeer{
+					Name:         p.Name,
+					ID:           p.ID,
+					StableID:     p.StableID,
+					TailscaleIPs: make([]netip.Addr, len(p.Addresses)),
+				}
+				for i, addr := range p.Addresses {
+					if addr.IsSingleIP() && tsaddr.IsTailscaleIP(addr.Addr()) {
+						fp.TailscaleIPs[i] = addr.Addr()
+					}
+				}
+				filtered = append(filtered, fp)
 			}
 		}
 		nm.Peers = peers
+		b.tka.filtered = filtered
+	} else {
+		b.tka.filtered = nil
 	}
 }
 
@@ -399,6 +420,11 @@ func (b *LocalBackend) NetworkLockStatus() *ipnstate.NetworkLockStatus {
 		}
 	}
 
+	filtered := make([]*ipnstate.TKAFilteredPeer, len(b.tka.filtered))
+	for i := 0; i < len(filtered); i++ {
+		filtered[i] = b.tka.filtered[i].Clone()
+	}
+
 	return &ipnstate.NetworkLockStatus{
 		Enabled:       true,
 		Head:          &head,
@@ -406,6 +432,7 @@ func (b *LocalBackend) NetworkLockStatus() *ipnstate.NetworkLockStatus {
 		NodeKey:       nodeKey,
 		NodeKeySigned: selfAuthorized,
 		TrustedKeys:   outKeys,
+		FilteredPeers: filtered,
 	}
 }
 

ipn/ipnstate/ipnstate.go

@@ -24,6 +24,8 @@ import (
 	"tailscale.com/util/dnsname"
 )
 
+//go:generate go run tailscale.com/cmd/cloner  -clonefunc=false -type=TKAFilteredPeer
+
 // Status represents the entire state of the IPN network.
 type Status struct {
 	// Version is the daemon's long version (see version.Long).
@@ -74,6 +76,16 @@ type TKAKey struct {
 	Votes    uint
 }
 
+// TKAFilteredPeer describes a peer which was removed from the netmap
+// (i.e. no connectivity) because it failed tailnet lock
+// checks.
+type TKAFilteredPeer struct {
+	Name         string // DNS
+	ID           tailcfg.NodeID
+	StableID     tailcfg.StableNodeID
+	TailscaleIPs []netip.Addr // Tailscale IP(s) assigned to this node
+}
+
 // NetworkLockStatus represents whether network-lock is enabled,
 // along with details about the locally-known state of the tailnet
 // key authority.
@@ -99,6 +111,11 @@ type NetworkLockStatus struct {
 	// TrustedKeys describes the keys currently trusted to make changes
 	// to network-lock.
 	TrustedKeys []TKAKey
+
+	// FilteredPeers describes peers which were removed from the netmap
+	// (i.e. no connectivity) because they failed tailnet lock
+	// checks.
+	FilteredPeers []*TKAFilteredPeer
 }
 
 // NetworkLockUpdate describes a change to network-lock state.

ipn/ipnstate/ipnstate_clone.go

@@ -0,0 +1,33 @@
+// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Code generated by tailscale.com/cmd/cloner; DO NOT EDIT.
+
+package ipnstate
+
+import (
+	"net/netip"
+
+	"tailscale.com/tailcfg"
+)
+
+// Clone makes a deep copy of TKAFilteredPeer.
+// The result aliases no memory with the original.
+func (src *TKAFilteredPeer) Clone() *TKAFilteredPeer {
+	if src == nil {
+		return nil
+	}
+	dst := new(TKAFilteredPeer)
+	*dst = *src
+	dst.TailscaleIPs = append(src.TailscaleIPs[:0:0], src.TailscaleIPs...)
+	return dst
+}
+
+// A compilation failure here means this code must be regenerated, with the command at the top of this file.
+var _TKAFilteredPeerCloneNeedsRegeneration = TKAFilteredPeer(struct {
+	Name         string
+	ID           tailcfg.NodeID
+	StableID     tailcfg.StableNodeID
+	TailscaleIPs []netip.Addr
+}{})