ipn/localapi: add localapi debug endpoints for packet filter/matches

For debugging #6423. This is easier than TS_DEBUG_MAP, as this means I
can pipe things into jq, etc.

Updates #6423

Change-Id: Ib3e7496b2eb3f47d4bed42e9b8045a441424b23c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

control/controlclient/map.go

@@ -16,6 +16,7 @@ import (
 	"tailscale.com/types/logger"
 	"tailscale.com/types/netmap"
 	"tailscale.com/types/opt"
+	"tailscale.com/types/views"
 	"tailscale.com/wgengine/filter"
 )
 
@@ -40,6 +41,7 @@ type mapSession struct {
 	lastDNSConfig          *tailcfg.DNSConfig
 	lastDERPMap            *tailcfg.DERPMap
 	lastUserProfile        map[tailcfg.UserID]tailcfg.UserProfile
+	lastPacketFilterRules  views.Slice[tailcfg.FilterRule]
 	lastParsedPacketFilter []filter.Match
 	lastSSHPolicy          *tailcfg.SSHPolicy
 	collectServices        bool
@@ -96,6 +98,7 @@ func (ms *mapSession) netmapForResponse(resp *tailcfg.MapResponse) *netmap.Netwo
 
 	if pf := resp.PacketFilter; pf != nil {
 		var err error
+		ms.lastPacketFilterRules = views.SliceOf(pf)
 		ms.lastParsedPacketFilter, err = filter.MatchesFromFilterRules(pf)
 		if err != nil {
 			ms.logf("parsePacketFilter: %v", err)
@@ -147,21 +150,22 @@ func (ms *mapSession) netmapForResponse(resp *tailcfg.MapResponse) *netmap.Netwo
 	}
 
 	nm := &netmap.NetworkMap{
-		NodeKey:          ms.privateNodeKey.Public(),
-		PrivateKey:       ms.privateNodeKey,
-		MachineKey:       ms.machinePubKey,
-		Peers:            resp.Peers,
-		UserProfiles:     make(map[tailcfg.UserID]tailcfg.UserProfile),
-		Domain:           ms.lastDomain,
-		DomainAuditLogID: ms.lastDomainAuditLogID,
-		DNS:              *ms.lastDNSConfig,
-		PacketFilter:     ms.lastParsedPacketFilter,
-		SSHPolicy:        ms.lastSSHPolicy,
-		CollectServices:  ms.collectServices,
-		DERPMap:          ms.lastDERPMap,
-		Debug:            debug,
-		ControlHealth:    ms.lastHealth,
-		TKAEnabled:       ms.lastTKAInfo != nil && !ms.lastTKAInfo.Disabled,
+		NodeKey:           ms.privateNodeKey.Public(),
+		PrivateKey:        ms.privateNodeKey,
+		MachineKey:        ms.machinePubKey,
+		Peers:             resp.Peers,
+		UserProfiles:      make(map[tailcfg.UserID]tailcfg.UserProfile),
+		Domain:            ms.lastDomain,
+		DomainAuditLogID:  ms.lastDomainAuditLogID,
+		DNS:               *ms.lastDNSConfig,
+		PacketFilter:      ms.lastParsedPacketFilter,
+		PacketFilterRules: ms.lastPacketFilterRules,
+		SSHPolicy:         ms.lastSSHPolicy,
+		CollectServices:   ms.collectServices,
+		DERPMap:           ms.lastDERPMap,
+		Debug:             debug,
+		ControlHealth:     ms.lastHealth,
+		TKAEnabled:        ms.lastTKAInfo != nil && !ms.lastTKAInfo.Disabled,
 	}
 	ms.netMapBuilding = nm
 

ipn/localapi/localapi.go

@@ -61,39 +61,41 @@ var handler = map[string]localAPIHandler{
 
 	// The other /localapi/v0/NAME handlers are exact matches and contain only NAME
 	// without a trailing slash:
-	"bugreport":               (*Handler).serveBugReport,
-	"check-ip-forwarding":     (*Handler).serveCheckIPForwarding,
-	"check-prefs":             (*Handler).serveCheckPrefs,
-	"component-debug-logging": (*Handler).serveComponentDebugLogging,
-	"debug":                   (*Handler).serveDebug,
-	"debug-derp-region":       (*Handler).serveDebugDERPRegion,
-	"derpmap":                 (*Handler).serveDERPMap,
-	"dev-set-state-store":     (*Handler).serveDevSetStateStore,
-	"dial":                    (*Handler).serveDial,
-	"file-targets":            (*Handler).serveFileTargets,
-	"goroutines":              (*Handler).serveGoroutines,
-	"id-token":                (*Handler).serveIDToken,
-	"login-interactive":       (*Handler).serveLoginInteractive,
-	"logout":                  (*Handler).serveLogout,
-	"metrics":                 (*Handler).serveMetrics,
-	"ping":                    (*Handler).servePing,
-	"prefs":                   (*Handler).servePrefs,
-	"pprof":                   (*Handler).servePprof,
-	"serve-config":            (*Handler).serveServeConfig,
-	"set-dns":                 (*Handler).serveSetDNS,
-	"set-expiry-sooner":       (*Handler).serveSetExpirySooner,
-	"start":                   (*Handler).serveStart,
-	"status":                  (*Handler).serveStatus,
-	"tka/init":                (*Handler).serveTKAInit,
-	"tka/log":                 (*Handler).serveTKALog,
-	"tka/modify":              (*Handler).serveTKAModify,
-	"tka/sign":                (*Handler).serveTKASign,
-	"tka/status":              (*Handler).serveTKAStatus,
-	"tka/disable":             (*Handler).serveTKADisable,
-	"tka/force-local-disable": (*Handler).serveTKALocalDisable,
-	"upload-client-metrics":   (*Handler).serveUploadClientMetrics,
-	"watch-ipn-bus":           (*Handler).serveWatchIPNBus,
-	"whois":                   (*Handler).serveWhoIs,
+	"bugreport":                   (*Handler).serveBugReport,
+	"check-ip-forwarding":         (*Handler).serveCheckIPForwarding,
+	"check-prefs":                 (*Handler).serveCheckPrefs,
+	"component-debug-logging":     (*Handler).serveComponentDebugLogging,
+	"debug":                       (*Handler).serveDebug,
+	"debug-derp-region":           (*Handler).serveDebugDERPRegion,
+	"debug-packet-filter-matches": (*Handler).serveDebugPacketFilterMatches,
+	"debug-packet-filter-rules":   (*Handler).serveDebugPacketFilterRules,
+	"derpmap":                     (*Handler).serveDERPMap,
+	"dev-set-state-store":         (*Handler).serveDevSetStateStore,
+	"dial":                        (*Handler).serveDial,
+	"file-targets":                (*Handler).serveFileTargets,
+	"goroutines":                  (*Handler).serveGoroutines,
+	"id-token":                    (*Handler).serveIDToken,
+	"login-interactive":           (*Handler).serveLoginInteractive,
+	"logout":                      (*Handler).serveLogout,
+	"metrics":                     (*Handler).serveMetrics,
+	"ping":                        (*Handler).servePing,
+	"prefs":                       (*Handler).servePrefs,
+	"pprof":                       (*Handler).servePprof,
+	"serve-config":                (*Handler).serveServeConfig,
+	"set-dns":                     (*Handler).serveSetDNS,
+	"set-expiry-sooner":           (*Handler).serveSetExpirySooner,
+	"start":                       (*Handler).serveStart,
+	"status":                      (*Handler).serveStatus,
+	"tka/init":                    (*Handler).serveTKAInit,
+	"tka/log":                     (*Handler).serveTKALog,
+	"tka/modify":                  (*Handler).serveTKAModify,
+	"tka/sign":                    (*Handler).serveTKASign,
+	"tka/status":                  (*Handler).serveTKAStatus,
+	"tka/disable":                 (*Handler).serveTKADisable,
+	"tka/force-local-disable":     (*Handler).serveTKALocalDisable,
+	"upload-client-metrics":       (*Handler).serveUploadClientMetrics,
+	"watch-ipn-bus":               (*Handler).serveWatchIPNBus,
+	"whois":                       (*Handler).serveWhoIs,
 }
 
 func randHex(n int) string {
@@ -506,6 +508,40 @@ func (h *Handler) serveDevSetStateStore(w http.ResponseWriter, r *http.Request)
 	io.WriteString(w, "done\n")
 }
 
+func (h *Handler) serveDebugPacketFilterRules(w http.ResponseWriter, r *http.Request) {
+	if !h.PermitWrite {
+		http.Error(w, "debug access denied", http.StatusForbidden)
+		return
+	}
+	nm := h.b.NetMap()
+	if nm == nil {
+		http.Error(w, "no netmap", http.StatusNotFound)
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+
+	enc := json.NewEncoder(w)
+	enc.SetIndent("", "\t")
+	enc.Encode(nm.PacketFilterRules)
+}
+
+func (h *Handler) serveDebugPacketFilterMatches(w http.ResponseWriter, r *http.Request) {
+	if !h.PermitWrite {
+		http.Error(w, "debug access denied", http.StatusForbidden)
+		return
+	}
+	nm := h.b.NetMap()
+	if nm == nil {
+		http.Error(w, "no netmap", http.StatusNotFound)
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+
+	enc := json.NewEncoder(w)
+	enc.SetIndent("", "\t")
+	enc.Encode(nm.PacketFilter)
+}
+
 func (h *Handler) serveComponentDebugLogging(w http.ResponseWriter, r *http.Request) {
 	if !h.PermitWrite {
 		http.Error(w, "debug access denied", http.StatusForbidden)

types/netmap/netmap.go

@@ -16,6 +16,7 @@ import (
 	"tailscale.com/tailcfg"
 	"tailscale.com/tka"
 	"tailscale.com/types/key"
+	"tailscale.com/types/views"
 	"tailscale.com/wgengine/filter"
 )
 
@@ -38,9 +39,10 @@ type NetworkMap struct {
 	Peers         []*tailcfg.Node // sorted by Node.ID
 	DNS           tailcfg.DNSConfig
 	// TODO(maisem) : replace with View.
-	Hostinfo     tailcfg.Hostinfo
-	PacketFilter []filter.Match
-	SSHPolicy    *tailcfg.SSHPolicy // or nil, if not enabled/allowed
+	Hostinfo          tailcfg.Hostinfo
+	PacketFilter      []filter.Match
+	PacketFilterRules views.Slice[tailcfg.FilterRule]
+	SSHPolicy         *tailcfg.SSHPolicy // or nil, if not enabled/allowed
 
 	// CollectServices reports whether this node's Tailnet has
 	// requested that info about services be included in HostInfo.