Update dependencies

2024-11-01 17:33:34 +00:00
parent 033ac0b400
commit 5cdfab398d
3596 changed files with 1033483 additions and 259 deletions
--- a/vendor/tailscale.com/appc/appconnector.go
+++ b/vendor/tailscale.com/appc/appconnector.go
@@ -0,0 +1,596 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Package appc implements App Connectors.
+// An AppConnector provides DNS domain oriented routing of traffic. An App
+// Connector becomes a DNS server for a peer, authoritative for the set of
+// configured domains. DNS resolution of the target domain triggers dynamic
+// publication of routes to ensure that traffic to the domain is routed through
+// the App Connector.
+package appc
+
+import (
+	"context"
+	"fmt"
+	"net/netip"
+	"slices"
+	"strings"
+	"sync"
+	"time"
+
+	xmaps "golang.org/x/exp/maps"
+	"golang.org/x/net/dns/dnsmessage"
+	"tailscale.com/types/logger"
+	"tailscale.com/types/views"
+	"tailscale.com/util/clientmetric"
+	"tailscale.com/util/dnsname"
+	"tailscale.com/util/execqueue"
+	"tailscale.com/util/mak"
+	"tailscale.com/util/slicesx"
+)
+
+// rateLogger responds to calls to update by adding a count for the current period and
+// calling the callback if any previous period has finished since update was last called
+type rateLogger struct {
+	interval    time.Duration
+	start       time.Time
+	periodStart time.Time
+	periodCount int64
+	now         func() time.Time
+	callback    func(int64, time.Time, int64)
+}
+
+func (rl *rateLogger) currentIntervalStart(now time.Time) time.Time {
+	millisSince := now.Sub(rl.start).Milliseconds() % rl.interval.Milliseconds()
+	return now.Add(-(time.Duration(millisSince)) * time.Millisecond)
+}
+
+func (rl *rateLogger) update(numRoutes int64) {
+	now := rl.now()
+	periodEnd := rl.periodStart.Add(rl.interval)
+	if periodEnd.Before(now) {
+		if rl.periodCount != 0 {
+			rl.callback(rl.periodCount, rl.periodStart, numRoutes)
+		}
+		rl.periodCount = 0
+		rl.periodStart = rl.currentIntervalStart(now)
+	}
+	rl.periodCount++
+}
+
+func newRateLogger(now func() time.Time, interval time.Duration, callback func(int64, time.Time, int64)) *rateLogger {
+	nowTime := now()
+	return &rateLogger{
+		callback:    callback,
+		now:         now,
+		interval:    interval,
+		start:       nowTime,
+		periodStart: nowTime,
+	}
+}
+
+// RouteAdvertiser is an interface that allows the AppConnector to advertise
+// newly discovered routes that need to be served through the AppConnector.
+type RouteAdvertiser interface {
+	// AdvertiseRoute adds one or more route advertisements skipping any that
+	// are already advertised.
+	AdvertiseRoute(...netip.Prefix) error
+
+	// UnadvertiseRoute removes any matching route advertisements.
+	UnadvertiseRoute(...netip.Prefix) error
+}
+
+var (
+	metricStoreRoutesRateBuckets = []int64{1, 2, 3, 4, 5, 10, 100, 1000}
+	metricStoreRoutesNBuckets    = []int64{1, 2, 3, 4, 5, 10, 100, 1000, 10000}
+	metricStoreRoutesRate        []*clientmetric.Metric
+	metricStoreRoutesN           []*clientmetric.Metric
+)
+
+func initMetricStoreRoutes() {
+	for _, n := range metricStoreRoutesRateBuckets {
+		metricStoreRoutesRate = append(metricStoreRoutesRate, clientmetric.NewCounter(fmt.Sprintf("appc_store_routes_rate_%d", n)))
+	}
+	metricStoreRoutesRate = append(metricStoreRoutesRate, clientmetric.NewCounter("appc_store_routes_rate_over"))
+	for _, n := range metricStoreRoutesNBuckets {
+		metricStoreRoutesN = append(metricStoreRoutesN, clientmetric.NewCounter(fmt.Sprintf("appc_store_routes_n_routes_%d", n)))
+	}
+	metricStoreRoutesN = append(metricStoreRoutesN, clientmetric.NewCounter("appc_store_routes_n_routes_over"))
+}
+
+func recordMetric(val int64, buckets []int64, metrics []*clientmetric.Metric) {
+	if len(buckets) < 1 {
+		return
+	}
+	// finds the first bucket where val <=, or len(buckets) if none match
+	// for bucket values of 1, 10, 100; 0-1 goes to [0], 2-10 goes to [1], 11-100 goes to [2], 101+ goes to [3]
+	bucket, _ := slices.BinarySearch(buckets, val)
+	metrics[bucket].Add(1)
+}
+
+func metricStoreRoutes(rate, nRoutes int64) {
+	if len(metricStoreRoutesRate) == 0 {
+		initMetricStoreRoutes()
+	}
+	recordMetric(rate, metricStoreRoutesRateBuckets, metricStoreRoutesRate)
+	recordMetric(nRoutes, metricStoreRoutesNBuckets, metricStoreRoutesN)
+}
+
+// RouteInfo is a data structure used to persist the in memory state of an AppConnector
+// so that we can know, even after a restart, which routes came from ACLs and which were
+// learned from domains.
+type RouteInfo struct {
+	// Control is the routes from the 'routes' section of an app connector acl.
+	Control []netip.Prefix `json:",omitempty"`
+	// Domains are the routes discovered by observing DNS lookups for configured domains.
+	Domains map[string][]netip.Addr `json:",omitempty"`
+	// Wildcards are the configured DNS lookup domains to observe. When a DNS query matches Wildcards,
+	// its result is added to Domains.
+	Wildcards []string `json:",omitempty"`
+}
+
+// AppConnector is an implementation of an AppConnector that performs
+// its function as a subsystem inside of a tailscale node. At the control plane
+// side App Connector routing is configured in terms of domains rather than IP
+// addresses.
+// The AppConnectors responsibility inside tailscaled is to apply the routing
+// and domain configuration as supplied in the map response.
+// DNS requests for configured domains are observed. If the domains resolve to
+// routes not yet served by the AppConnector the local node configuration is
+// updated to advertise the new route.
+type AppConnector struct {
+	logf            logger.Logf
+	routeAdvertiser RouteAdvertiser
+
+	// storeRoutesFunc will be called to persist routes if it is not nil.
+	storeRoutesFunc func(*RouteInfo) error
+
+	// mu guards the fields that follow
+	mu sync.Mutex
+
+	// domains is a map of lower case domain names with no trailing dot, to an
+	// ordered list of resolved IP addresses.
+	domains map[string][]netip.Addr
+
+	// controlRoutes is the list of routes that were last supplied by control.
+	controlRoutes []netip.Prefix
+
+	// wildcards is the list of domain strings that match subdomains.
+	wildcards []string
+
+	// queue provides ordering for update operations
+	queue execqueue.ExecQueue
+
+	writeRateMinute *rateLogger
+	writeRateDay    *rateLogger
+}
+
+// NewAppConnector creates a new AppConnector.
+func NewAppConnector(logf logger.Logf, routeAdvertiser RouteAdvertiser, routeInfo *RouteInfo, storeRoutesFunc func(*RouteInfo) error) *AppConnector {
+	ac := &AppConnector{
+		logf:            logger.WithPrefix(logf, "appc: "),
+		routeAdvertiser: routeAdvertiser,
+		storeRoutesFunc: storeRoutesFunc,
+	}
+	if routeInfo != nil {
+		ac.domains = routeInfo.Domains
+		ac.wildcards = routeInfo.Wildcards
+		ac.controlRoutes = routeInfo.Control
+	}
+	ac.writeRateMinute = newRateLogger(time.Now, time.Minute, func(c int64, s time.Time, l int64) {
+		ac.logf("routeInfo write rate: %d in minute starting at %v (%d routes)", c, s, l)
+		metricStoreRoutes(c, l)
+	})
+	ac.writeRateDay = newRateLogger(time.Now, 24*time.Hour, func(c int64, s time.Time, l int64) {
+		ac.logf("routeInfo write rate: %d in 24 hours starting at %v (%d routes)", c, s, l)
+	})
+	return ac
+}
+
+// ShouldStoreRoutes returns true if the appconnector was created with the controlknob on
+// and is storing its discovered routes persistently.
+func (e *AppConnector) ShouldStoreRoutes() bool {
+	return e.storeRoutesFunc != nil
+}
+
+// storeRoutesLocked takes the current state of the AppConnector and persists it
+func (e *AppConnector) storeRoutesLocked() error {
+	if !e.ShouldStoreRoutes() {
+		return nil
+	}
+
+	// log write rate and write size
+	numRoutes := int64(len(e.controlRoutes))
+	for _, rs := range e.domains {
+		numRoutes += int64(len(rs))
+	}
+	e.writeRateMinute.update(numRoutes)
+	e.writeRateDay.update(numRoutes)
+
+	return e.storeRoutesFunc(&RouteInfo{
+		Control:   e.controlRoutes,
+		Domains:   e.domains,
+		Wildcards: e.wildcards,
+	})
+}
+
+// ClearRoutes removes all route state from the AppConnector.
+func (e *AppConnector) ClearRoutes() error {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	e.controlRoutes = nil
+	e.domains = nil
+	e.wildcards = nil
+	return e.storeRoutesLocked()
+}
+
+// UpdateDomainsAndRoutes starts an asynchronous update of the configuration
+// given the new domains and routes.
+func (e *AppConnector) UpdateDomainsAndRoutes(domains []string, routes []netip.Prefix) {
+	e.queue.Add(func() {
+		// Add the new routes first.
+		e.updateRoutes(routes)
+		e.updateDomains(domains)
+	})
+}
+
+// UpdateDomains asynchronously replaces the current set of configured domains
+// with the supplied set of domains. Domains must not contain a trailing dot,
+// and should be lower case. If the domain contains a leading '*' label it
+// matches all subdomains of a domain.
+func (e *AppConnector) UpdateDomains(domains []string) {
+	e.queue.Add(func() {
+		e.updateDomains(domains)
+	})
+}
+
+// Wait waits for the currently scheduled asynchronous configuration changes to
+// complete.
+func (e *AppConnector) Wait(ctx context.Context) {
+	e.queue.Wait(ctx)
+}
+
+func (e *AppConnector) updateDomains(domains []string) {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	var oldDomains map[string][]netip.Addr
+	oldDomains, e.domains = e.domains, make(map[string][]netip.Addr, len(domains))
+	e.wildcards = e.wildcards[:0]
+	for _, d := range domains {
+		d = strings.ToLower(d)
+		if len(d) == 0 {
+			continue
+		}
+		if strings.HasPrefix(d, "*.") {
+			e.wildcards = append(e.wildcards, d[2:])
+			continue
+		}
+		e.domains[d] = oldDomains[d]
+		delete(oldDomains, d)
+	}
+
+	// Ensure that still-live wildcards addresses are preserved as well.
+	for d, addrs := range oldDomains {
+		for _, wc := range e.wildcards {
+			if dnsname.HasSuffix(d, wc) {
+				e.domains[d] = addrs
+				delete(oldDomains, d)
+				break
+			}
+		}
+	}
+
+	// Everything left in oldDomains is a domain we're no longer tracking
+	// and if we are storing route info we can unadvertise the routes
+	if e.ShouldStoreRoutes() {
+		toRemove := []netip.Prefix{}
+		for _, addrs := range oldDomains {
+			for _, a := range addrs {
+				toRemove = append(toRemove, netip.PrefixFrom(a, a.BitLen()))
+			}
+		}
+		if err := e.routeAdvertiser.UnadvertiseRoute(toRemove...); err != nil {
+			e.logf("failed to unadvertise routes on domain removal: %v: %v: %v", xmaps.Keys(oldDomains), toRemove, err)
+		}
+	}
+
+	e.logf("handling domains: %v and wildcards: %v", xmaps.Keys(e.domains), e.wildcards)
+}
+
+// updateRoutes merges the supplied routes into the currently configured routes. The routes supplied
+// by control for UpdateRoutes are supplemental to the routes discovered by DNS resolution, but are
+// also more often whole ranges. UpdateRoutes will remove any single address routes that are now
+// covered by new ranges.
+func (e *AppConnector) updateRoutes(routes []netip.Prefix) {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	// If there was no change since the last update, no work to do.
+	if slices.Equal(e.controlRoutes, routes) {
+		return
+	}
+
+	if err := e.routeAdvertiser.AdvertiseRoute(routes...); err != nil {
+		e.logf("failed to advertise routes: %v: %v", routes, err)
+		return
+	}
+
+	var toRemove []netip.Prefix
+
+	// If we're storing routes and know e.controlRoutes is a good
+	// representation of what should be in AdvertisedRoutes we can stop
+	// advertising routes that used to be in e.controlRoutes but are not
+	// in routes.
+	if e.ShouldStoreRoutes() {
+		toRemove = routesWithout(e.controlRoutes, routes)
+	}
+
+nextRoute:
+	for _, r := range routes {
+		for _, addr := range e.domains {
+			for _, a := range addr {
+				if r.Contains(a) && netip.PrefixFrom(a, a.BitLen()) != r {
+					pfx := netip.PrefixFrom(a, a.BitLen())
+					toRemove = append(toRemove, pfx)
+					continue nextRoute
+				}
+			}
+		}
+	}
+
+	if err := e.routeAdvertiser.UnadvertiseRoute(toRemove...); err != nil {
+		e.logf("failed to unadvertise routes: %v: %v", toRemove, err)
+	}
+
+	e.controlRoutes = routes
+	if err := e.storeRoutesLocked(); err != nil {
+		e.logf("failed to store route info: %v", err)
+	}
+}
+
+// Domains returns the currently configured domain list.
+func (e *AppConnector) Domains() views.Slice[string] {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	return views.SliceOf(xmaps.Keys(e.domains))
+}
+
+// DomainRoutes returns a map of domains to resolved IP
+// addresses.
+func (e *AppConnector) DomainRoutes() map[string][]netip.Addr {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	drCopy := make(map[string][]netip.Addr)
+	for k, v := range e.domains {
+		drCopy[k] = append(drCopy[k], v...)
+	}
+
+	return drCopy
+}
+
+// ObserveDNSResponse is a callback invoked by the DNS resolver when a DNS
+// response is being returned over the PeerAPI. The response is parsed and
+// matched against the configured domains, if matched the routeAdvertiser is
+// advised to advertise the discovered route.
+func (e *AppConnector) ObserveDNSResponse(res []byte) {
+	var p dnsmessage.Parser
+	if _, err := p.Start(res); err != nil {
+		return
+	}
+	if err := p.SkipAllQuestions(); err != nil {
+		return
+	}
+
+	// cnameChain tracks a chain of CNAMEs for a given query in order to reverse
+	// a CNAME chain back to the original query for flattening. The keys are
+	// CNAME record targets, and the value is the name the record answers, so
+	// for www.example.com CNAME example.com, the map would contain
+	// ["example.com"] = "www.example.com".
+	var cnameChain map[string]string
+
+	// addressRecords is a list of address records found in the response.
+	var addressRecords map[string][]netip.Addr
+
+	for {
+		h, err := p.AnswerHeader()
+		if err == dnsmessage.ErrSectionDone {
+			break
+		}
+		if err != nil {
+			return
+		}
+
+		if h.Class != dnsmessage.ClassINET {
+			if err := p.SkipAnswer(); err != nil {
+				return
+			}
+			continue
+		}
+
+		switch h.Type {
+		case dnsmessage.TypeCNAME, dnsmessage.TypeA, dnsmessage.TypeAAAA:
+		default:
+			if err := p.SkipAnswer(); err != nil {
+				return
+			}
+			continue
+
+		}
+
+		domain := strings.TrimSuffix(strings.ToLower(h.Name.String()), ".")
+		if len(domain) == 0 {
+			continue
+		}
+
+		if h.Type == dnsmessage.TypeCNAME {
+			res, err := p.CNAMEResource()
+			if err != nil {
+				return
+			}
+			cname := strings.TrimSuffix(strings.ToLower(res.CNAME.String()), ".")
+			if len(cname) == 0 {
+				continue
+			}
+			mak.Set(&cnameChain, cname, domain)
+			continue
+		}
+
+		switch h.Type {
+		case dnsmessage.TypeA:
+			r, err := p.AResource()
+			if err != nil {
+				return
+			}
+			addr := netip.AddrFrom4(r.A)
+			mak.Set(&addressRecords, domain, append(addressRecords[domain], addr))
+		case dnsmessage.TypeAAAA:
+			r, err := p.AAAAResource()
+			if err != nil {
+				return
+			}
+			addr := netip.AddrFrom16(r.AAAA)
+			mak.Set(&addressRecords, domain, append(addressRecords[domain], addr))
+		default:
+			if err := p.SkipAnswer(); err != nil {
+				return
+			}
+			continue
+		}
+	}
+
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	for domain, addrs := range addressRecords {
+		domain, isRouted := e.findRoutedDomainLocked(domain, cnameChain)
+
+		// domain and none of the CNAMEs in the chain are routed
+		if !isRouted {
+			continue
+		}
+
+		// advertise each address we have learned for the routed domain, that
+		// was not already known.
+		var toAdvertise []netip.Prefix
+		for _, addr := range addrs {
+			if !e.isAddrKnownLocked(domain, addr) {
+				toAdvertise = append(toAdvertise, netip.PrefixFrom(addr, addr.BitLen()))
+			}
+		}
+
+		if len(toAdvertise) > 0 {
+			e.logf("[v2] observed new routes for %s: %s", domain, toAdvertise)
+			e.scheduleAdvertisement(domain, toAdvertise...)
+		}
+	}
+}
+
+// starting from the given domain that resolved to an address, find it, or any
+// of the domains in the CNAME chain toward resolving it, that are routed
+// domains, returning the routed domain name and a bool indicating whether a
+// routed domain was found.
+// e.mu must be held.
+func (e *AppConnector) findRoutedDomainLocked(domain string, cnameChain map[string]string) (string, bool) {
+	var isRouted bool
+	for {
+		_, isRouted = e.domains[domain]
+		if isRouted {
+			break
+		}
+
+		// match wildcard domains
+		for _, wc := range e.wildcards {
+			if dnsname.HasSuffix(domain, wc) {
+				e.domains[domain] = nil
+				isRouted = true
+				break
+			}
+		}
+
+		next, ok := cnameChain[domain]
+		if !ok {
+			break
+		}
+		domain = next
+	}
+	return domain, isRouted
+}
+
+// isAddrKnownLocked returns true if the address is known to be associated with
+// the given domain. Known domain tables are updated for covered routes to speed
+// up future matches.
+// e.mu must be held.
+func (e *AppConnector) isAddrKnownLocked(domain string, addr netip.Addr) bool {
+	if e.hasDomainAddrLocked(domain, addr) {
+		return true
+	}
+	for _, route := range e.controlRoutes {
+		if route.Contains(addr) {
+			// record the new address associated with the domain for faster matching in subsequent
+			// requests and for diagnostic records.
+			e.addDomainAddrLocked(domain, addr)
+			return true
+		}
+	}
+	return false
+}
+
+// scheduleAdvertisement schedules an advertisement of the given address
+// associated with the given domain.
+func (e *AppConnector) scheduleAdvertisement(domain string, routes ...netip.Prefix) {
+	e.queue.Add(func() {
+		if err := e.routeAdvertiser.AdvertiseRoute(routes...); err != nil {
+			e.logf("failed to advertise routes for %s: %v: %v", domain, routes, err)
+			return
+		}
+		e.mu.Lock()
+		defer e.mu.Unlock()
+
+		for _, route := range routes {
+			if !route.IsSingleIP() {
+				continue
+			}
+			addr := route.Addr()
+			if !e.hasDomainAddrLocked(domain, addr) {
+				e.addDomainAddrLocked(domain, addr)
+				e.logf("[v2] advertised route for %v: %v", domain, addr)
+			}
+		}
+		if err := e.storeRoutesLocked(); err != nil {
+			e.logf("failed to store route info: %v", err)
+		}
+	})
+}
+
+// hasDomainAddrLocked returns true if the address has been observed in a
+// resolution of domain.
+func (e *AppConnector) hasDomainAddrLocked(domain string, addr netip.Addr) bool {
+	_, ok := slices.BinarySearchFunc(e.domains[domain], addr, compareAddr)
+	return ok
+}
+
+// addDomainAddrLocked adds the address to the list of addresses resolved for
+// domain and ensures the list remains sorted. Does not attempt to deduplicate.
+func (e *AppConnector) addDomainAddrLocked(domain string, addr netip.Addr) {
+	e.domains[domain] = append(e.domains[domain], addr)
+	slices.SortFunc(e.domains[domain], compareAddr)
+}
+
+func compareAddr(l, r netip.Addr) int {
+	return l.Compare(r)
+}
+
+// routesWithout returns a without b where a and b
+// are unsorted slices of netip.Prefix
+func routesWithout(a, b []netip.Prefix) []netip.Prefix {
+	m := make(map[netip.Prefix]bool, len(b))
+	for _, p := range b {
+		m[p] = true
+	}
+	return slicesx.Filter(make([]netip.Prefix, 0, len(a)), a, func(p netip.Prefix) bool {
+		return !m[p]
+	})
+}