mirror of
https://github.com/tailscale/tailscale.git
synced 2024-12-13 03:34:43 +00:00
f0347e841f
The io/ioutil package has been deprecated as of Go 1.16 [1]. This commit replaces the existing io/ioutil functions with their new definitions in io and os packages. Reference: https://golang.org/doc/go1.16#ioutil Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
1476 lines
39 KiB
Go
1476 lines
39 KiB
Go
// Copyright (c) 2020 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.
|
|
|
|
// Package netcheck checks the network conditions from the current host.
|
|
package netcheck
|
|
|
|
import (
|
|
"bufio"
|
|
"context"
|
|
"crypto/tls"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"log"
|
|
"net"
|
|
"net/http"
|
|
"net/netip"
|
|
"runtime"
|
|
"sort"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/tcnksm/go-httpstat"
|
|
"tailscale.com/derp/derphttp"
|
|
"tailscale.com/envknob"
|
|
"tailscale.com/net/interfaces"
|
|
"tailscale.com/net/netaddr"
|
|
"tailscale.com/net/neterror"
|
|
"tailscale.com/net/netns"
|
|
"tailscale.com/net/ping"
|
|
"tailscale.com/net/portmapper"
|
|
"tailscale.com/net/stun"
|
|
"tailscale.com/syncs"
|
|
"tailscale.com/tailcfg"
|
|
"tailscale.com/types/logger"
|
|
"tailscale.com/types/nettype"
|
|
"tailscale.com/types/opt"
|
|
"tailscale.com/util/clientmetric"
|
|
"tailscale.com/util/mak"
|
|
)
|
|
|
|
// Debugging and experimentation tweakables.
|
|
var (
|
|
debugNetcheck = envknob.RegisterBool("TS_DEBUG_NETCHECK")
|
|
)
|
|
|
|
// The various default timeouts for things.
|
|
const (
|
|
// overallProbeTimeout is the maximum amount of time netcheck will
|
|
// spend gathering a single report.
|
|
overallProbeTimeout = 5 * time.Second
|
|
// stunTimeout is the maximum amount of time netcheck will spend
|
|
// probing with STUN packets without getting a reply before
|
|
// switching to HTTP probing, on the assumption that outbound UDP
|
|
// is blocked.
|
|
stunProbeTimeout = 3 * time.Second
|
|
// icmpProbeTimeout is the maximum amount of time netcheck will spend
|
|
// probing with ICMP packets.
|
|
icmpProbeTimeout = 1 * time.Second
|
|
// hairpinCheckTimeout is the amount of time we wait for a
|
|
// hairpinned packet to come back.
|
|
hairpinCheckTimeout = 100 * time.Millisecond
|
|
// defaultActiveRetransmitTime is the retransmit interval we use
|
|
// for STUN probes when we're in steady state (not in start-up),
|
|
// but don't have previous latency information for a DERP
|
|
// node. This is a somewhat conservative guess because if we have
|
|
// no data, likely the DERP node is very far away and we have no
|
|
// data because we timed out the last time we probed it.
|
|
defaultActiveRetransmitTime = 200 * time.Millisecond
|
|
// defaultInitialRetransmitTime is the retransmit interval used
|
|
// when netcheck first runs. We have no past context to work with,
|
|
// and we want answers relatively quickly, so it's biased slightly
|
|
// more aggressive than defaultActiveRetransmitTime. A few extra
|
|
// packets at startup is fine.
|
|
defaultInitialRetransmitTime = 100 * time.Millisecond
|
|
)
|
|
|
|
type Report struct {
|
|
UDP bool // a UDP STUN round trip completed
|
|
IPv6 bool // an IPv6 STUN round trip completed
|
|
IPv4 bool // an IPv4 STUN round trip completed
|
|
IPv6CanSend bool // an IPv6 packet was able to be sent
|
|
IPv4CanSend bool // an IPv4 packet was able to be sent
|
|
OSHasIPv6 bool // could bind a socket to ::1
|
|
ICMPv4 bool // an ICMPv4 round trip completed
|
|
|
|
// MappingVariesByDestIP is whether STUN results depend which
|
|
// STUN server you're talking to (on IPv4).
|
|
MappingVariesByDestIP opt.Bool
|
|
|
|
// HairPinning is whether the router supports communicating
|
|
// between two local devices through the NATted public IP address
|
|
// (on IPv4).
|
|
HairPinning opt.Bool
|
|
|
|
// UPnP is whether UPnP appears present on the LAN.
|
|
// Empty means not checked.
|
|
UPnP opt.Bool
|
|
// PMP is whether NAT-PMP appears present on the LAN.
|
|
// Empty means not checked.
|
|
PMP opt.Bool
|
|
// PCP is whether PCP appears present on the LAN.
|
|
// Empty means not checked.
|
|
PCP opt.Bool
|
|
|
|
PreferredDERP int // or 0 for unknown
|
|
RegionLatency map[int]time.Duration // keyed by DERP Region ID
|
|
RegionV4Latency map[int]time.Duration // keyed by DERP Region ID
|
|
RegionV6Latency map[int]time.Duration // keyed by DERP Region ID
|
|
|
|
GlobalV4 string // ip:port of global IPv4
|
|
GlobalV6 string // [ip]:port of global IPv6
|
|
|
|
// TODO: update Clone when adding new fields
|
|
}
|
|
|
|
// AnyPortMappingChecked reports whether any of UPnP, PMP, or PCP are non-empty.
|
|
func (r *Report) AnyPortMappingChecked() bool {
|
|
return r.UPnP != "" || r.PMP != "" || r.PCP != ""
|
|
}
|
|
|
|
func (r *Report) Clone() *Report {
|
|
if r == nil {
|
|
return nil
|
|
}
|
|
r2 := *r
|
|
r2.RegionLatency = cloneDurationMap(r2.RegionLatency)
|
|
r2.RegionV4Latency = cloneDurationMap(r2.RegionV4Latency)
|
|
r2.RegionV6Latency = cloneDurationMap(r2.RegionV6Latency)
|
|
return &r2
|
|
}
|
|
|
|
func cloneDurationMap(m map[int]time.Duration) map[int]time.Duration {
|
|
if m == nil {
|
|
return nil
|
|
}
|
|
m2 := make(map[int]time.Duration, len(m))
|
|
for k, v := range m {
|
|
m2[k] = v
|
|
}
|
|
return m2
|
|
}
|
|
|
|
// Client generates a netcheck Report.
|
|
type Client struct {
|
|
// Verbose enables verbose logging.
|
|
Verbose bool
|
|
|
|
// Logf optionally specifies where to log to.
|
|
// If nil, log.Printf is used.
|
|
Logf logger.Logf
|
|
|
|
// TimeNow, if non-nil, is used instead of time.Now.
|
|
TimeNow func() time.Time
|
|
|
|
// GetSTUNConn4 optionally provides a func to return the
|
|
// connection to use for sending & receiving IPv4 packets. If
|
|
// nil, an emphemeral one is created as needed.
|
|
GetSTUNConn4 func() STUNConn
|
|
|
|
// GetSTUNConn6 is like GetSTUNConn4, but for IPv6.
|
|
GetSTUNConn6 func() STUNConn
|
|
|
|
// SkipExternalNetwork controls whether the client should not try
|
|
// to reach things other than localhost. This is set to true
|
|
// in tests to avoid probing the local LAN's router, etc.
|
|
SkipExternalNetwork bool
|
|
|
|
// UDPBindAddr, if non-empty, is the address to listen on for UDP.
|
|
// It defaults to ":0".
|
|
UDPBindAddr string
|
|
|
|
// PortMapper, if non-nil, is used for portmap queries.
|
|
// If nil, portmap discovery is not done.
|
|
PortMapper *portmapper.Client // lazily initialized on first use
|
|
|
|
mu sync.Mutex // guards following
|
|
nextFull bool // do a full region scan, even if last != nil
|
|
prev map[time.Time]*Report // some previous reports
|
|
last *Report // most recent report
|
|
lastFull time.Time // time of last full (non-incremental) report
|
|
curState *reportState // non-nil if we're in a call to GetReportn
|
|
}
|
|
|
|
// STUNConn is the interface required by the netcheck Client when
|
|
// reusing an existing UDP connection.
|
|
type STUNConn interface {
|
|
WriteToUDPAddrPort([]byte, netip.AddrPort) (int, error)
|
|
WriteTo([]byte, net.Addr) (int, error)
|
|
ReadFrom([]byte) (int, net.Addr, error)
|
|
}
|
|
|
|
func (c *Client) enoughRegions() int {
|
|
if c.Verbose {
|
|
// Abuse verbose a bit here so netcheck can show all region latencies
|
|
// in verbose mode.
|
|
return 100
|
|
}
|
|
return 3
|
|
}
|
|
|
|
func (c *Client) logf(format string, a ...any) {
|
|
if c.Logf != nil {
|
|
c.Logf(format, a...)
|
|
} else {
|
|
log.Printf(format, a...)
|
|
}
|
|
}
|
|
|
|
func (c *Client) vlogf(format string, a ...any) {
|
|
if c.Verbose || debugNetcheck() {
|
|
c.logf(format, a...)
|
|
}
|
|
}
|
|
|
|
// handleHairSTUN reports whether pkt (from src) was our magic hairpin
|
|
// probe packet that we sent to ourselves.
|
|
func (c *Client) handleHairSTUNLocked(pkt []byte, src netip.AddrPort) bool {
|
|
rs := c.curState
|
|
if rs == nil {
|
|
return false
|
|
}
|
|
if tx, err := stun.ParseBindingRequest(pkt); err == nil && tx == rs.hairTX {
|
|
select {
|
|
case rs.gotHairSTUN <- src:
|
|
default:
|
|
}
|
|
return true
|
|
}
|
|
return false
|
|
}
|
|
|
|
// MakeNextReportFull forces the next GetReport call to be a full
|
|
// (non-incremental) probe of all DERP regions.
|
|
func (c *Client) MakeNextReportFull() {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
c.nextFull = true
|
|
}
|
|
|
|
func (c *Client) ReceiveSTUNPacket(pkt []byte, src netip.AddrPort) {
|
|
c.vlogf("received STUN packet from %s", src)
|
|
|
|
if src.Addr().Is4() {
|
|
metricSTUNRecv4.Add(1)
|
|
} else if src.Addr().Is6() {
|
|
metricSTUNRecv6.Add(1)
|
|
}
|
|
|
|
c.mu.Lock()
|
|
if c.handleHairSTUNLocked(pkt, src) {
|
|
c.mu.Unlock()
|
|
return
|
|
}
|
|
rs := c.curState
|
|
c.mu.Unlock()
|
|
|
|
if rs == nil {
|
|
return
|
|
}
|
|
|
|
tx, addrPort, err := stun.ParseResponse(pkt)
|
|
if err != nil {
|
|
if _, err := stun.ParseBindingRequest(pkt); err == nil {
|
|
// This was probably our own netcheck hairpin
|
|
// check probe coming in late. Ignore.
|
|
return
|
|
}
|
|
c.logf("netcheck: received unexpected STUN message response from %v: %v", src, err)
|
|
return
|
|
}
|
|
|
|
rs.mu.Lock()
|
|
onDone, ok := rs.inFlight[tx]
|
|
if ok {
|
|
delete(rs.inFlight, tx)
|
|
}
|
|
rs.mu.Unlock()
|
|
if ok {
|
|
onDone(addrPort)
|
|
}
|
|
}
|
|
|
|
// probeProto is the protocol used to time a node's latency.
|
|
type probeProto uint8
|
|
|
|
const (
|
|
probeIPv4 probeProto = iota // STUN IPv4
|
|
probeIPv6 // STUN IPv6
|
|
probeHTTPS // HTTPS
|
|
)
|
|
|
|
type probe struct {
|
|
// delay is when the probe is started, relative to the time
|
|
// that GetReport is called. One probe in each probePlan
|
|
// should have a delay of 0. Non-zero values are for retries
|
|
// on UDP loss or timeout.
|
|
delay time.Duration
|
|
|
|
// node is the name of the node name. DERP node names are globally
|
|
// unique so there's no region ID.
|
|
node string
|
|
|
|
// proto is how the node should be probed.
|
|
proto probeProto
|
|
|
|
// wait is how long to wait until the probe is considered failed.
|
|
// 0 means to use a default value.
|
|
wait time.Duration
|
|
}
|
|
|
|
// probePlan is a set of node probes to run.
|
|
// The map key is a descriptive name, only used for tests.
|
|
//
|
|
// The values are logically an unordered set of tests to run concurrently.
|
|
// In practice there's some order to them based on their delay fields,
|
|
// but multiple probes can have the same delay time or be running concurrently
|
|
// both within and between sets.
|
|
//
|
|
// A set of probes is done once either one of the probes completes, or
|
|
// the next probe to run wouldn't yield any new information not
|
|
// already discovered by any previous probe in any set.
|
|
type probePlan map[string][]probe
|
|
|
|
// sortRegions returns the regions of dm first sorted
|
|
// from fastest to slowest (based on the 'last' report),
|
|
// end in regions that have no data.
|
|
func sortRegions(dm *tailcfg.DERPMap, last *Report) (prev []*tailcfg.DERPRegion) {
|
|
prev = make([]*tailcfg.DERPRegion, 0, len(dm.Regions))
|
|
for _, reg := range dm.Regions {
|
|
if reg.Avoid {
|
|
continue
|
|
}
|
|
prev = append(prev, reg)
|
|
}
|
|
sort.Slice(prev, func(i, j int) bool {
|
|
da, db := last.RegionLatency[prev[i].RegionID], last.RegionLatency[prev[j].RegionID]
|
|
if db == 0 && da != 0 {
|
|
// Non-zero sorts before zero.
|
|
return true
|
|
}
|
|
if da == 0 {
|
|
// Zero can't sort before anything else.
|
|
return false
|
|
}
|
|
return da < db
|
|
})
|
|
return prev
|
|
}
|
|
|
|
// numIncrementalRegions is the number of fastest regions to
|
|
// periodically re-query during incremental netcheck reports. (During
|
|
// a full report, all regions are scanned.)
|
|
const numIncrementalRegions = 3
|
|
|
|
// makeProbePlan generates the probe plan for a DERPMap, given the most
|
|
// recent report and whether IPv6 is configured on an interface.
|
|
func makeProbePlan(dm *tailcfg.DERPMap, ifState *interfaces.State, last *Report) (plan probePlan) {
|
|
if last == nil || len(last.RegionLatency) == 0 {
|
|
return makeProbePlanInitial(dm, ifState)
|
|
}
|
|
have6if := ifState.HaveV6
|
|
have4if := ifState.HaveV4
|
|
plan = make(probePlan)
|
|
if !have4if && !have6if {
|
|
return plan
|
|
}
|
|
had4 := len(last.RegionV4Latency) > 0
|
|
had6 := len(last.RegionV6Latency) > 0
|
|
hadBoth := have6if && had4 && had6
|
|
for ri, reg := range sortRegions(dm, last) {
|
|
if ri == numIncrementalRegions {
|
|
break
|
|
}
|
|
var p4, p6 []probe
|
|
do4 := have4if
|
|
do6 := have6if
|
|
|
|
// By default, each node only gets one STUN packet sent,
|
|
// except the fastest two from the previous round.
|
|
tries := 1
|
|
isFastestTwo := ri < 2
|
|
|
|
if isFastestTwo {
|
|
tries = 2
|
|
} else if hadBoth {
|
|
// For dual stack machines, make the 3rd & slower nodes alternate
|
|
// between.
|
|
if ri%2 == 0 {
|
|
do4, do6 = true, false
|
|
} else {
|
|
do4, do6 = false, true
|
|
}
|
|
}
|
|
if !isFastestTwo && !had6 {
|
|
do6 = false
|
|
}
|
|
|
|
if reg.RegionID == last.PreferredDERP {
|
|
// But if we already had a DERP home, try extra hard to
|
|
// make sure it's there so we don't flip flop around.
|
|
tries = 4
|
|
}
|
|
|
|
for try := 0; try < tries; try++ {
|
|
if len(reg.Nodes) == 0 {
|
|
// Shouldn't be possible.
|
|
continue
|
|
}
|
|
if try != 0 && !had6 {
|
|
do6 = false
|
|
}
|
|
n := reg.Nodes[try%len(reg.Nodes)]
|
|
prevLatency := last.RegionLatency[reg.RegionID] * 120 / 100
|
|
if prevLatency == 0 {
|
|
prevLatency = defaultActiveRetransmitTime
|
|
}
|
|
delay := time.Duration(try) * prevLatency
|
|
if try > 1 {
|
|
delay += time.Duration(try) * 50 * time.Millisecond
|
|
}
|
|
if do4 {
|
|
p4 = append(p4, probe{delay: delay, node: n.Name, proto: probeIPv4})
|
|
}
|
|
if do6 {
|
|
p6 = append(p6, probe{delay: delay, node: n.Name, proto: probeIPv6})
|
|
}
|
|
}
|
|
if len(p4) > 0 {
|
|
plan[fmt.Sprintf("region-%d-v4", reg.RegionID)] = p4
|
|
}
|
|
if len(p6) > 0 {
|
|
plan[fmt.Sprintf("region-%d-v6", reg.RegionID)] = p6
|
|
}
|
|
}
|
|
return plan
|
|
}
|
|
|
|
func makeProbePlanInitial(dm *tailcfg.DERPMap, ifState *interfaces.State) (plan probePlan) {
|
|
plan = make(probePlan)
|
|
|
|
for _, reg := range dm.Regions {
|
|
var p4 []probe
|
|
var p6 []probe
|
|
for try := 0; try < 3; try++ {
|
|
n := reg.Nodes[try%len(reg.Nodes)]
|
|
delay := time.Duration(try) * defaultInitialRetransmitTime
|
|
if ifState.HaveV4 && nodeMight4(n) {
|
|
p4 = append(p4, probe{delay: delay, node: n.Name, proto: probeIPv4})
|
|
}
|
|
if ifState.HaveV6 && nodeMight6(n) {
|
|
p6 = append(p6, probe{delay: delay, node: n.Name, proto: probeIPv6})
|
|
}
|
|
}
|
|
if len(p4) > 0 {
|
|
plan[fmt.Sprintf("region-%d-v4", reg.RegionID)] = p4
|
|
}
|
|
if len(p6) > 0 {
|
|
plan[fmt.Sprintf("region-%d-v6", reg.RegionID)] = p6
|
|
}
|
|
}
|
|
return plan
|
|
}
|
|
|
|
// nodeMight6 reports whether n might reply to STUN over IPv6 based on
|
|
// its config alone, without DNS lookups. It only returns false if
|
|
// it's not explicitly disabled.
|
|
func nodeMight6(n *tailcfg.DERPNode) bool {
|
|
if n.IPv6 == "" {
|
|
return true
|
|
}
|
|
ip, _ := netip.ParseAddr(n.IPv6)
|
|
return ip.Is6()
|
|
|
|
}
|
|
|
|
// nodeMight4 reports whether n might reply to STUN over IPv4 based on
|
|
// its config alone, without DNS lookups. It only returns false if
|
|
// it's not explicitly disabled.
|
|
func nodeMight4(n *tailcfg.DERPNode) bool {
|
|
if n.IPv4 == "" {
|
|
return true
|
|
}
|
|
ip, _ := netip.ParseAddr(n.IPv4)
|
|
return ip.Is4()
|
|
}
|
|
|
|
// readPackets reads STUN packets from pc until there's an error or ctx is done.
|
|
// In either case, it closes pc.
|
|
func (c *Client) readPackets(ctx context.Context, pc net.PacketConn) {
|
|
done := make(chan struct{})
|
|
defer close(done)
|
|
|
|
go func() {
|
|
select {
|
|
case <-ctx.Done():
|
|
case <-done:
|
|
}
|
|
pc.Close()
|
|
}()
|
|
|
|
var buf [64 << 10]byte
|
|
for {
|
|
n, addr, err := pc.ReadFrom(buf[:])
|
|
if err != nil {
|
|
if ctx.Err() != nil {
|
|
return
|
|
}
|
|
c.logf("ReadFrom: %v", err)
|
|
return
|
|
}
|
|
ua, ok := addr.(*net.UDPAddr)
|
|
if !ok {
|
|
c.logf("ReadFrom: unexpected addr %T", addr)
|
|
continue
|
|
}
|
|
pkt := buf[:n]
|
|
if !stun.Is(pkt) {
|
|
continue
|
|
}
|
|
if ap := netaddr.Unmap(ua.AddrPort()); ap.IsValid() {
|
|
c.ReceiveSTUNPacket(pkt, ap)
|
|
}
|
|
}
|
|
}
|
|
|
|
// reportState holds the state for a single invocation of Client.GetReport.
|
|
type reportState struct {
|
|
c *Client
|
|
hairTX stun.TxID
|
|
gotHairSTUN chan netip.AddrPort
|
|
hairTimeout chan struct{} // closed on timeout
|
|
pc4 STUNConn
|
|
pc6 STUNConn
|
|
pc4Hair nettype.PacketConn
|
|
incremental bool // doing a lite, follow-up netcheck
|
|
stopProbeCh chan struct{}
|
|
waitPortMap sync.WaitGroup
|
|
|
|
mu sync.Mutex
|
|
sentHairCheck bool
|
|
report *Report // to be returned by GetReport
|
|
inFlight map[stun.TxID]func(netip.AddrPort) // called without c.mu held
|
|
gotEP4 string
|
|
timers []*time.Timer
|
|
}
|
|
|
|
func (rs *reportState) anyUDP() bool {
|
|
rs.mu.Lock()
|
|
defer rs.mu.Unlock()
|
|
return rs.report.UDP
|
|
}
|
|
|
|
func (rs *reportState) haveRegionLatency(regionID int) bool {
|
|
rs.mu.Lock()
|
|
defer rs.mu.Unlock()
|
|
_, ok := rs.report.RegionLatency[regionID]
|
|
return ok
|
|
}
|
|
|
|
// probeWouldHelp reports whether executing the given probe would
|
|
// yield any new information.
|
|
// The given node is provided just because the sole caller already has it
|
|
// and it saves a lookup.
|
|
func (rs *reportState) probeWouldHelp(probe probe, node *tailcfg.DERPNode) bool {
|
|
rs.mu.Lock()
|
|
defer rs.mu.Unlock()
|
|
|
|
// If the probe is for a region we don't yet know about, that
|
|
// would help.
|
|
if _, ok := rs.report.RegionLatency[node.RegionID]; !ok {
|
|
return true
|
|
}
|
|
|
|
// If the probe is for IPv6 and we don't yet have an IPv6
|
|
// report, that would help.
|
|
if probe.proto == probeIPv6 && len(rs.report.RegionV6Latency) == 0 {
|
|
return true
|
|
}
|
|
|
|
// For IPv4, we need at least two IPv4 results overall to
|
|
// determine whether we're behind a NAT that shows us as
|
|
// different source IPs and/or ports depending on who we're
|
|
// talking to. If we don't yet have two results yet
|
|
// (MappingVariesByDestIP is blank), then another IPv4 probe
|
|
// would be good.
|
|
if probe.proto == probeIPv4 && rs.report.MappingVariesByDestIP == "" {
|
|
return true
|
|
}
|
|
|
|
// Otherwise not interesting.
|
|
return false
|
|
}
|
|
|
|
func (rs *reportState) startHairCheckLocked(dst netip.AddrPort) {
|
|
if rs.sentHairCheck || rs.incremental {
|
|
return
|
|
}
|
|
rs.sentHairCheck = true
|
|
rs.pc4Hair.WriteToUDPAddrPort(stun.Request(rs.hairTX), dst)
|
|
rs.c.vlogf("sent haircheck to %v", dst)
|
|
time.AfterFunc(hairpinCheckTimeout, func() { close(rs.hairTimeout) })
|
|
}
|
|
|
|
func (rs *reportState) waitHairCheck(ctx context.Context) {
|
|
rs.mu.Lock()
|
|
defer rs.mu.Unlock()
|
|
ret := rs.report
|
|
if rs.incremental {
|
|
if rs.c.last != nil {
|
|
ret.HairPinning = rs.c.last.HairPinning
|
|
}
|
|
return
|
|
}
|
|
if !rs.sentHairCheck {
|
|
return
|
|
}
|
|
|
|
select {
|
|
case <-rs.gotHairSTUN:
|
|
ret.HairPinning.Set(true)
|
|
case <-rs.hairTimeout:
|
|
rs.c.vlogf("hairCheck timeout")
|
|
ret.HairPinning.Set(false)
|
|
default:
|
|
select {
|
|
case <-rs.gotHairSTUN:
|
|
ret.HairPinning.Set(true)
|
|
case <-rs.hairTimeout:
|
|
ret.HairPinning.Set(false)
|
|
case <-ctx.Done():
|
|
}
|
|
}
|
|
}
|
|
|
|
func (rs *reportState) stopTimers() {
|
|
rs.mu.Lock()
|
|
defer rs.mu.Unlock()
|
|
for _, t := range rs.timers {
|
|
t.Stop()
|
|
}
|
|
}
|
|
|
|
// addNodeLatency updates rs to note that node's latency is d. If ipp
|
|
// is non-zero (for all but HTTPS replies), it's recorded as our UDP
|
|
// IP:port.
|
|
func (rs *reportState) addNodeLatency(node *tailcfg.DERPNode, ipp netip.AddrPort, d time.Duration) {
|
|
var ipPortStr string
|
|
if ipp != (netip.AddrPort{}) {
|
|
ipPortStr = net.JoinHostPort(ipp.Addr().String(), fmt.Sprint(ipp.Port()))
|
|
}
|
|
|
|
rs.mu.Lock()
|
|
defer rs.mu.Unlock()
|
|
ret := rs.report
|
|
|
|
ret.UDP = true
|
|
updateLatency(ret.RegionLatency, node.RegionID, d)
|
|
|
|
// Once we've heard from enough regions (3), start a timer to
|
|
// give up on the other ones. The timer's duration is a
|
|
// function of whether this is our initial full probe or an
|
|
// incremental one. For incremental ones, wait for the
|
|
// duration of the slowest region. For initial ones, double
|
|
// that.
|
|
if len(ret.RegionLatency) == rs.c.enoughRegions() {
|
|
timeout := maxDurationValue(ret.RegionLatency)
|
|
if !rs.incremental {
|
|
timeout *= 2
|
|
}
|
|
rs.timers = append(rs.timers, time.AfterFunc(timeout, rs.stopProbes))
|
|
}
|
|
|
|
switch {
|
|
case ipp.Addr().Is6():
|
|
updateLatency(ret.RegionV6Latency, node.RegionID, d)
|
|
ret.IPv6 = true
|
|
ret.GlobalV6 = ipPortStr
|
|
// TODO: track MappingVariesByDestIP for IPv6
|
|
// too? Would be sad if so, but who knows.
|
|
case ipp.Addr().Is4():
|
|
updateLatency(ret.RegionV4Latency, node.RegionID, d)
|
|
ret.IPv4 = true
|
|
if rs.gotEP4 == "" {
|
|
rs.gotEP4 = ipPortStr
|
|
ret.GlobalV4 = ipPortStr
|
|
rs.startHairCheckLocked(ipp)
|
|
} else {
|
|
if rs.gotEP4 != ipPortStr {
|
|
ret.MappingVariesByDestIP.Set(true)
|
|
} else if ret.MappingVariesByDestIP == "" {
|
|
ret.MappingVariesByDestIP.Set(false)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
func (rs *reportState) stopProbes() {
|
|
select {
|
|
case rs.stopProbeCh <- struct{}{}:
|
|
default:
|
|
}
|
|
}
|
|
|
|
func (rs *reportState) setOptBool(b *opt.Bool, v bool) {
|
|
rs.mu.Lock()
|
|
defer rs.mu.Unlock()
|
|
b.Set(v)
|
|
}
|
|
|
|
func (rs *reportState) probePortMapServices() {
|
|
defer rs.waitPortMap.Done()
|
|
|
|
rs.setOptBool(&rs.report.UPnP, false)
|
|
rs.setOptBool(&rs.report.PMP, false)
|
|
rs.setOptBool(&rs.report.PCP, false)
|
|
|
|
res, err := rs.c.PortMapper.Probe(context.Background())
|
|
if err != nil {
|
|
if !errors.Is(err, portmapper.ErrGatewayRange) {
|
|
// "skipping portmap; gateway range likely lacks support"
|
|
// is not very useful, and too spammy on cloud systems.
|
|
// If there are other errors, we want to log those.
|
|
rs.c.logf("probePortMapServices: %v", err)
|
|
}
|
|
return
|
|
}
|
|
|
|
rs.setOptBool(&rs.report.UPnP, res.UPnP)
|
|
rs.setOptBool(&rs.report.PMP, res.PMP)
|
|
rs.setOptBool(&rs.report.PCP, res.PCP)
|
|
}
|
|
|
|
func newReport() *Report {
|
|
return &Report{
|
|
RegionLatency: make(map[int]time.Duration),
|
|
RegionV4Latency: make(map[int]time.Duration),
|
|
RegionV6Latency: make(map[int]time.Duration),
|
|
}
|
|
}
|
|
|
|
func (c *Client) udpBindAddr() string {
|
|
if v := c.UDPBindAddr; v != "" {
|
|
return v
|
|
}
|
|
return ":0"
|
|
}
|
|
|
|
// GetReport gets a report.
|
|
//
|
|
// It may not be called concurrently with itself.
|
|
func (c *Client) GetReport(ctx context.Context, dm *tailcfg.DERPMap) (_ *Report, reterr error) {
|
|
defer func() {
|
|
if reterr != nil {
|
|
metricNumGetReportError.Add(1)
|
|
}
|
|
}()
|
|
metricNumGetReport.Add(1)
|
|
// Mask user context with ours that we guarantee to cancel so
|
|
// we can depend on it being closed in goroutines later.
|
|
// (User ctx might be context.Background, etc)
|
|
ctx, cancel := context.WithTimeout(ctx, overallProbeTimeout)
|
|
defer cancel()
|
|
|
|
if dm == nil {
|
|
return nil, errors.New("netcheck: GetReport: DERP map is nil")
|
|
}
|
|
|
|
c.mu.Lock()
|
|
if c.curState != nil {
|
|
c.mu.Unlock()
|
|
return nil, errors.New("invalid concurrent call to GetReport")
|
|
}
|
|
rs := &reportState{
|
|
c: c,
|
|
report: newReport(),
|
|
inFlight: map[stun.TxID]func(netip.AddrPort){},
|
|
hairTX: stun.NewTxID(), // random payload
|
|
gotHairSTUN: make(chan netip.AddrPort, 1),
|
|
hairTimeout: make(chan struct{}),
|
|
stopProbeCh: make(chan struct{}, 1),
|
|
}
|
|
c.curState = rs
|
|
last := c.last
|
|
now := c.timeNow()
|
|
if c.nextFull || now.Sub(c.lastFull) > 5*time.Minute {
|
|
last = nil // causes makeProbePlan below to do a full (initial) plan
|
|
c.nextFull = false
|
|
c.lastFull = now
|
|
metricNumGetReportFull.Add(1)
|
|
}
|
|
rs.incremental = last != nil
|
|
c.mu.Unlock()
|
|
|
|
defer func() {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
c.curState = nil
|
|
}()
|
|
|
|
if runtime.GOOS == "js" {
|
|
if err := c.runHTTPOnlyChecks(ctx, last, rs, dm); err != nil {
|
|
return nil, err
|
|
}
|
|
return c.finishAndStoreReport(rs, dm), nil
|
|
}
|
|
|
|
ifState, err := interfaces.GetState()
|
|
if err != nil {
|
|
c.logf("[v1] interfaces: %v", err)
|
|
return nil, err
|
|
}
|
|
|
|
// See if IPv6 works at all, or if it's been hard disabled at the
|
|
// OS level.
|
|
v6udp, err := nettype.MakePacketListenerWithNetIP(netns.Listener(c.logf)).ListenPacket(ctx, "udp6", "[::1]:0")
|
|
if err == nil {
|
|
rs.report.OSHasIPv6 = true
|
|
v6udp.Close()
|
|
}
|
|
|
|
// Create a UDP4 socket used for sending to our discovered IPv4 address.
|
|
rs.pc4Hair, err = nettype.MakePacketListenerWithNetIP(netns.Listener(c.logf)).ListenPacket(ctx, "udp4", ":0")
|
|
if err != nil {
|
|
c.logf("udp4: %v", err)
|
|
return nil, err
|
|
}
|
|
defer rs.pc4Hair.Close()
|
|
|
|
if !c.SkipExternalNetwork && c.PortMapper != nil {
|
|
rs.waitPortMap.Add(1)
|
|
go rs.probePortMapServices()
|
|
}
|
|
|
|
// At least the Apple Airport Extreme doesn't allow hairpin
|
|
// sends from a private socket until it's seen traffic from
|
|
// that src IP:port to something else out on the internet.
|
|
//
|
|
// See https://github.com/tailscale/tailscale/issues/188#issuecomment-600728643
|
|
//
|
|
// And it seems that even sending to a likely-filtered RFC 5737
|
|
// documentation-only IPv4 range is enough to set up the mapping.
|
|
// So do that for now. In the future we might want to classify networks
|
|
// that do and don't require this separately. But for now help it.
|
|
const documentationIP = "203.0.113.1"
|
|
rs.pc4Hair.WriteTo([]byte("tailscale netcheck; see https://github.com/tailscale/tailscale/issues/188"), &net.UDPAddr{IP: net.ParseIP(documentationIP), Port: 12345})
|
|
|
|
if f := c.GetSTUNConn4; f != nil {
|
|
rs.pc4 = f()
|
|
} else {
|
|
u4, err := nettype.MakePacketListenerWithNetIP(netns.Listener(c.logf)).ListenPacket(ctx, "udp4", c.udpBindAddr())
|
|
if err != nil {
|
|
c.logf("udp4: %v", err)
|
|
return nil, err
|
|
}
|
|
rs.pc4 = u4
|
|
go c.readPackets(ctx, u4)
|
|
}
|
|
|
|
if ifState.HaveV6 {
|
|
if f := c.GetSTUNConn6; f != nil {
|
|
rs.pc6 = f()
|
|
} else {
|
|
u6, err := nettype.MakePacketListenerWithNetIP(netns.Listener(c.logf)).ListenPacket(ctx, "udp6", c.udpBindAddr())
|
|
if err != nil {
|
|
c.logf("udp6: %v", err)
|
|
} else {
|
|
rs.pc6 = u6
|
|
go c.readPackets(ctx, u6)
|
|
}
|
|
}
|
|
}
|
|
|
|
plan := makeProbePlan(dm, ifState, last)
|
|
|
|
wg := syncs.NewWaitGroupChan()
|
|
wg.Add(len(plan))
|
|
for _, probeSet := range plan {
|
|
setCtx, cancelSet := context.WithCancel(ctx)
|
|
go func(probeSet []probe) {
|
|
for _, probe := range probeSet {
|
|
go rs.runProbe(setCtx, dm, probe, cancelSet)
|
|
}
|
|
<-setCtx.Done()
|
|
wg.Decr()
|
|
}(probeSet)
|
|
}
|
|
|
|
stunTimer := time.NewTimer(stunProbeTimeout)
|
|
defer stunTimer.Stop()
|
|
|
|
select {
|
|
case <-stunTimer.C:
|
|
case <-ctx.Done():
|
|
case <-wg.DoneChan():
|
|
case <-rs.stopProbeCh:
|
|
// Saw enough regions.
|
|
c.vlogf("saw enough regions; not waiting for rest")
|
|
}
|
|
|
|
rs.waitHairCheck(ctx)
|
|
c.vlogf("hairCheck done")
|
|
if !c.SkipExternalNetwork && c.PortMapper != nil {
|
|
rs.waitPortMap.Wait()
|
|
c.vlogf("portMap done")
|
|
}
|
|
rs.stopTimers()
|
|
|
|
// Try HTTPS and ICMP latency check if all STUN probes failed due to
|
|
// UDP presumably being blocked.
|
|
// TODO: this should be moved into the probePlan, using probeProto probeHTTPS.
|
|
if !rs.anyUDP() && ctx.Err() == nil {
|
|
var wg sync.WaitGroup
|
|
var need []*tailcfg.DERPRegion
|
|
for rid, reg := range dm.Regions {
|
|
if !rs.haveRegionLatency(rid) && regionHasDERPNode(reg) {
|
|
need = append(need, reg)
|
|
}
|
|
}
|
|
if len(need) > 0 {
|
|
// Kick off ICMP in parallel to HTTPS checks; we don't
|
|
// reuse the same WaitGroup for those probes because we
|
|
// need to close the underlying Pinger after a timeout
|
|
// or when all ICMP probes are done, regardless of
|
|
// whether the HTTPS probes have finished.
|
|
wg.Add(1)
|
|
go func() {
|
|
defer wg.Done()
|
|
if err := c.measureAllICMPLatency(ctx, rs, need); err != nil {
|
|
c.logf("[v1] measureAllICMPLatency: %v", err)
|
|
}
|
|
}()
|
|
|
|
wg.Add(len(need))
|
|
c.logf("netcheck: UDP is blocked, trying HTTPS")
|
|
}
|
|
for _, reg := range need {
|
|
go func(reg *tailcfg.DERPRegion) {
|
|
defer wg.Done()
|
|
if d, ip, err := c.measureHTTPSLatency(ctx, reg); err != nil {
|
|
c.logf("[v1] netcheck: measuring HTTPS latency of %v (%d): %v", reg.RegionCode, reg.RegionID, err)
|
|
} else {
|
|
rs.mu.Lock()
|
|
if l, ok := rs.report.RegionLatency[reg.RegionID]; !ok {
|
|
mak.Set(&rs.report.RegionLatency, reg.RegionID, d)
|
|
} else if l >= d {
|
|
rs.report.RegionLatency[reg.RegionID] = d
|
|
}
|
|
// We set these IPv4 and IPv6 but they're not really used
|
|
// and we don't necessarily set them both. If UDP is blocked
|
|
// and both IPv4 and IPv6 are available over TCP, it's basically
|
|
// random which fields end up getting set here.
|
|
// Since they're not needed, that's fine for now.
|
|
if ip.Is4() {
|
|
rs.report.IPv4 = true
|
|
}
|
|
if ip.Is6() {
|
|
rs.report.IPv6 = true
|
|
}
|
|
rs.mu.Unlock()
|
|
}
|
|
}(reg)
|
|
}
|
|
wg.Wait()
|
|
}
|
|
|
|
return c.finishAndStoreReport(rs, dm), nil
|
|
}
|
|
|
|
func (c *Client) finishAndStoreReport(rs *reportState, dm *tailcfg.DERPMap) *Report {
|
|
rs.mu.Lock()
|
|
report := rs.report.Clone()
|
|
rs.mu.Unlock()
|
|
|
|
c.addReportHistoryAndSetPreferredDERP(report)
|
|
c.logConciseReport(report, dm)
|
|
|
|
return report
|
|
}
|
|
|
|
// runHTTPOnlyChecks is the netcheck done by environments that can
|
|
// only do HTTP requests, such as ws/wasm.
|
|
func (c *Client) runHTTPOnlyChecks(ctx context.Context, last *Report, rs *reportState, dm *tailcfg.DERPMap) error {
|
|
var regions []*tailcfg.DERPRegion
|
|
if rs.incremental && last != nil {
|
|
for rid := range last.RegionLatency {
|
|
if dr, ok := dm.Regions[rid]; ok {
|
|
regions = append(regions, dr)
|
|
}
|
|
}
|
|
}
|
|
if len(regions) == 0 {
|
|
for _, dr := range dm.Regions {
|
|
regions = append(regions, dr)
|
|
}
|
|
}
|
|
c.logf("running HTTP-only netcheck against %v regions", len(regions))
|
|
|
|
var wg sync.WaitGroup
|
|
for _, rg := range regions {
|
|
if len(rg.Nodes) == 0 {
|
|
continue
|
|
}
|
|
wg.Add(1)
|
|
rg := rg
|
|
go func() {
|
|
defer wg.Done()
|
|
node := rg.Nodes[0]
|
|
req, _ := http.NewRequestWithContext(ctx, "HEAD", "https://"+node.HostName+"/derp/probe", nil)
|
|
// One warm-up one to get HTTP connection set
|
|
// up and get a connection from the browser's
|
|
// pool.
|
|
if r, err := http.DefaultClient.Do(req); err != nil || r.StatusCode > 299 {
|
|
if err != nil {
|
|
c.logf("probing %s: %v", node.HostName, err)
|
|
} else {
|
|
c.logf("probing %s: unexpected status %s", node.HostName, r.Status)
|
|
}
|
|
return
|
|
}
|
|
t0 := c.timeNow()
|
|
if r, err := http.DefaultClient.Do(req); err != nil || r.StatusCode > 299 {
|
|
if err != nil {
|
|
c.logf("probing %s: %v", node.HostName, err)
|
|
} else {
|
|
c.logf("probing %s: unexpected status %s", node.HostName, r.Status)
|
|
}
|
|
return
|
|
}
|
|
d := c.timeNow().Sub(t0)
|
|
rs.addNodeLatency(node, netip.AddrPort{}, d)
|
|
}()
|
|
}
|
|
wg.Wait()
|
|
return nil
|
|
}
|
|
|
|
func (c *Client) measureHTTPSLatency(ctx context.Context, reg *tailcfg.DERPRegion) (time.Duration, netip.Addr, error) {
|
|
metricHTTPSend.Add(1)
|
|
var result httpstat.Result
|
|
ctx, cancel := context.WithTimeout(httpstat.WithHTTPStat(ctx, &result), overallProbeTimeout)
|
|
defer cancel()
|
|
|
|
var ip netip.Addr
|
|
|
|
dc := derphttp.NewNetcheckClient(c.logf)
|
|
tlsConn, tcpConn, node, err := dc.DialRegionTLS(ctx, reg)
|
|
if err != nil {
|
|
return 0, ip, err
|
|
}
|
|
defer tcpConn.Close()
|
|
|
|
if ta, ok := tlsConn.RemoteAddr().(*net.TCPAddr); ok {
|
|
ip, _ = netip.AddrFromSlice(ta.IP)
|
|
ip = ip.Unmap()
|
|
}
|
|
if ip == (netip.Addr{}) {
|
|
return 0, ip, fmt.Errorf("no unexpected RemoteAddr %#v", tlsConn.RemoteAddr())
|
|
}
|
|
|
|
connc := make(chan *tls.Conn, 1)
|
|
connc <- tlsConn
|
|
|
|
tr := &http.Transport{
|
|
DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
|
|
return nil, errors.New("unexpected DialContext dial")
|
|
},
|
|
DialTLSContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
|
|
select {
|
|
case nc := <-connc:
|
|
return nc, nil
|
|
default:
|
|
return nil, errors.New("only one conn expected")
|
|
}
|
|
},
|
|
}
|
|
hc := &http.Client{Transport: tr}
|
|
|
|
req, err := http.NewRequestWithContext(ctx, "GET", "https://"+node.HostName+"/derp/latency-check", nil)
|
|
if err != nil {
|
|
return 0, ip, err
|
|
}
|
|
|
|
resp, err := hc.Do(req)
|
|
if err != nil {
|
|
return 0, ip, err
|
|
}
|
|
defer resp.Body.Close()
|
|
|
|
// DERPs should give us a nominal status code, so anything else is probably
|
|
// an access denied by a MITM proxy (or at the very least a signal not to
|
|
// trust this latency check).
|
|
if resp.StatusCode > 299 {
|
|
return 0, ip, fmt.Errorf("unexpected status code: %d (%s)", resp.StatusCode, resp.Status)
|
|
}
|
|
|
|
_, err = io.Copy(io.Discard, io.LimitReader(resp.Body, 8<<10))
|
|
if err != nil {
|
|
return 0, ip, err
|
|
}
|
|
result.End(c.timeNow())
|
|
|
|
// TODO: decide best timing heuristic here.
|
|
// Maybe the server should return the tcpinfo_rtt?
|
|
return result.ServerProcessing, ip, nil
|
|
}
|
|
|
|
func (c *Client) measureAllICMPLatency(ctx context.Context, rs *reportState, need []*tailcfg.DERPRegion) error {
|
|
if len(need) == 0 {
|
|
return nil
|
|
}
|
|
ctx, done := context.WithTimeout(ctx, icmpProbeTimeout)
|
|
defer done()
|
|
|
|
p, err := ping.New(ctx, c.logf)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer p.Close()
|
|
|
|
c.logf("UDP is blocked, trying ICMP")
|
|
|
|
var wg sync.WaitGroup
|
|
wg.Add(len(need))
|
|
for _, reg := range need {
|
|
go func(reg *tailcfg.DERPRegion) {
|
|
defer wg.Done()
|
|
if d, err := c.measureICMPLatency(ctx, reg, p); err != nil {
|
|
c.logf("[v1] measuring ICMP latency of %v (%d): %v", reg.RegionCode, reg.RegionID, err)
|
|
} else {
|
|
c.logf("[v1] ICMP latency of %v (%d): %v", reg.RegionCode, reg.RegionID, d)
|
|
rs.mu.Lock()
|
|
if l, ok := rs.report.RegionLatency[reg.RegionID]; !ok {
|
|
mak.Set(&rs.report.RegionLatency, reg.RegionID, d)
|
|
} else if l >= d {
|
|
rs.report.RegionLatency[reg.RegionID] = d
|
|
}
|
|
|
|
// We only send IPv4 ICMP right now
|
|
rs.report.IPv4 = true
|
|
rs.report.ICMPv4 = true
|
|
|
|
rs.mu.Unlock()
|
|
}
|
|
}(reg)
|
|
}
|
|
|
|
wg.Wait()
|
|
return nil
|
|
}
|
|
|
|
func (c *Client) measureICMPLatency(ctx context.Context, reg *tailcfg.DERPRegion, p *ping.Pinger) (time.Duration, error) {
|
|
if len(reg.Nodes) == 0 {
|
|
return 0, fmt.Errorf("no nodes for region %d (%v)", reg.RegionID, reg.RegionCode)
|
|
}
|
|
|
|
// Try pinging the first node in the region
|
|
node := reg.Nodes[0]
|
|
|
|
// Get the IPAddr by asking for the UDP address that we would use for
|
|
// STUN and then using that IP.
|
|
//
|
|
// TODO(andrew-d): this is a bit ugly
|
|
nodeAddr := c.nodeAddr(ctx, node, probeIPv4)
|
|
if !nodeAddr.IsValid() {
|
|
return 0, fmt.Errorf("no address for node %v", node.Name)
|
|
}
|
|
addr := &net.IPAddr{
|
|
IP: net.IP(nodeAddr.Addr().AsSlice()),
|
|
Zone: nodeAddr.Addr().Zone(),
|
|
}
|
|
|
|
// Use the unique node.Name field as the packet data to reduce the
|
|
// likelihood that we get a mismatched echo response.
|
|
return p.Send(ctx, addr, []byte(node.Name))
|
|
}
|
|
|
|
func (c *Client) logConciseReport(r *Report, dm *tailcfg.DERPMap) {
|
|
c.logf("[v1] report: %v", logger.ArgWriter(func(w *bufio.Writer) {
|
|
fmt.Fprintf(w, "udp=%v", r.UDP)
|
|
if !r.IPv4 {
|
|
fmt.Fprintf(w, " v4=%v", r.IPv4)
|
|
}
|
|
if !r.UDP {
|
|
fmt.Fprintf(w, " icmpv4=%v", r.ICMPv4)
|
|
}
|
|
|
|
fmt.Fprintf(w, " v6=%v", r.IPv6)
|
|
fmt.Fprintf(w, " mapvarydest=%v", r.MappingVariesByDestIP)
|
|
fmt.Fprintf(w, " hair=%v", r.HairPinning)
|
|
if r.AnyPortMappingChecked() {
|
|
fmt.Fprintf(w, " portmap=%v%v%v", conciseOptBool(r.UPnP, "U"), conciseOptBool(r.PMP, "M"), conciseOptBool(r.PCP, "C"))
|
|
} else {
|
|
fmt.Fprintf(w, " portmap=?")
|
|
}
|
|
if r.GlobalV4 != "" {
|
|
fmt.Fprintf(w, " v4a=%v", r.GlobalV4)
|
|
}
|
|
if r.GlobalV6 != "" {
|
|
fmt.Fprintf(w, " v6a=%v", r.GlobalV6)
|
|
}
|
|
fmt.Fprintf(w, " derp=%v", r.PreferredDERP)
|
|
if r.PreferredDERP != 0 {
|
|
fmt.Fprintf(w, " derpdist=")
|
|
needComma := false
|
|
for _, rid := range dm.RegionIDs() {
|
|
if d := r.RegionV4Latency[rid]; d != 0 {
|
|
if needComma {
|
|
w.WriteByte(',')
|
|
}
|
|
fmt.Fprintf(w, "%dv4:%v", rid, d.Round(time.Millisecond))
|
|
needComma = true
|
|
}
|
|
if d := r.RegionV6Latency[rid]; d != 0 {
|
|
if needComma {
|
|
w.WriteByte(',')
|
|
}
|
|
fmt.Fprintf(w, "%dv6:%v", rid, d.Round(time.Millisecond))
|
|
needComma = true
|
|
}
|
|
}
|
|
}
|
|
}))
|
|
}
|
|
|
|
func (c *Client) timeNow() time.Time {
|
|
if c.TimeNow != nil {
|
|
return c.TimeNow()
|
|
}
|
|
return time.Now()
|
|
}
|
|
|
|
// addReportHistoryAndSetPreferredDERP adds r to the set of recent Reports
|
|
// and mutates r.PreferredDERP to contain the best recent one.
|
|
func (c *Client) addReportHistoryAndSetPreferredDERP(r *Report) {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
|
|
var prevDERP int
|
|
if c.last != nil {
|
|
prevDERP = c.last.PreferredDERP
|
|
}
|
|
if c.prev == nil {
|
|
c.prev = map[time.Time]*Report{}
|
|
}
|
|
now := c.timeNow()
|
|
c.prev[now] = r
|
|
c.last = r
|
|
|
|
const maxAge = 5 * time.Minute
|
|
|
|
// region ID => its best recent latency in last maxAge
|
|
bestRecent := map[int]time.Duration{}
|
|
|
|
for t, pr := range c.prev {
|
|
if now.Sub(t) > maxAge {
|
|
delete(c.prev, t)
|
|
continue
|
|
}
|
|
for regionID, d := range pr.RegionLatency {
|
|
if bd, ok := bestRecent[regionID]; !ok || d < bd {
|
|
bestRecent[regionID] = d
|
|
}
|
|
}
|
|
}
|
|
|
|
// Then, pick which currently-alive DERP server from the
|
|
// current report has the best latency over the past maxAge.
|
|
var bestAny time.Duration
|
|
var oldRegionCurLatency time.Duration
|
|
for regionID, d := range r.RegionLatency {
|
|
if regionID == prevDERP {
|
|
oldRegionCurLatency = d
|
|
}
|
|
best := bestRecent[regionID]
|
|
if r.PreferredDERP == 0 || best < bestAny {
|
|
bestAny = best
|
|
r.PreferredDERP = regionID
|
|
}
|
|
}
|
|
|
|
// If we're changing our preferred DERP but the old one's still
|
|
// accessible and the new one's not much better, just stick with
|
|
// where we are.
|
|
if prevDERP != 0 &&
|
|
r.PreferredDERP != prevDERP &&
|
|
oldRegionCurLatency != 0 &&
|
|
bestAny > oldRegionCurLatency/3*2 {
|
|
r.PreferredDERP = prevDERP
|
|
}
|
|
}
|
|
|
|
func updateLatency(m map[int]time.Duration, regionID int, d time.Duration) {
|
|
if prev, ok := m[regionID]; !ok || d < prev {
|
|
m[regionID] = d
|
|
}
|
|
}
|
|
|
|
func namedNode(dm *tailcfg.DERPMap, nodeName string) *tailcfg.DERPNode {
|
|
if dm == nil {
|
|
return nil
|
|
}
|
|
for _, r := range dm.Regions {
|
|
for _, n := range r.Nodes {
|
|
if n.Name == nodeName {
|
|
return n
|
|
}
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (rs *reportState) runProbe(ctx context.Context, dm *tailcfg.DERPMap, probe probe, cancelSet func()) {
|
|
c := rs.c
|
|
node := namedNode(dm, probe.node)
|
|
if node == nil {
|
|
c.logf("netcheck.runProbe: named node %q not found", probe.node)
|
|
return
|
|
}
|
|
|
|
if probe.delay > 0 {
|
|
delayTimer := time.NewTimer(probe.delay)
|
|
select {
|
|
case <-delayTimer.C:
|
|
case <-ctx.Done():
|
|
delayTimer.Stop()
|
|
return
|
|
}
|
|
}
|
|
|
|
if !rs.probeWouldHelp(probe, node) {
|
|
cancelSet()
|
|
return
|
|
}
|
|
|
|
addr := c.nodeAddr(ctx, node, probe.proto)
|
|
if !addr.IsValid() {
|
|
return
|
|
}
|
|
|
|
txID := stun.NewTxID()
|
|
req := stun.Request(txID)
|
|
|
|
sent := time.Now() // after DNS lookup above
|
|
|
|
rs.mu.Lock()
|
|
rs.inFlight[txID] = func(ipp netip.AddrPort) {
|
|
rs.addNodeLatency(node, ipp, time.Since(sent))
|
|
cancelSet() // abort other nodes in this set
|
|
}
|
|
rs.mu.Unlock()
|
|
|
|
switch probe.proto {
|
|
case probeIPv4:
|
|
metricSTUNSend4.Add(1)
|
|
n, err := rs.pc4.WriteToUDPAddrPort(req, addr)
|
|
if n == len(req) && err == nil || neterror.TreatAsLostUDP(err) {
|
|
rs.mu.Lock()
|
|
rs.report.IPv4CanSend = true
|
|
rs.mu.Unlock()
|
|
}
|
|
case probeIPv6:
|
|
metricSTUNSend6.Add(1)
|
|
n, err := rs.pc6.WriteToUDPAddrPort(req, addr)
|
|
if n == len(req) && err == nil || neterror.TreatAsLostUDP(err) {
|
|
rs.mu.Lock()
|
|
rs.report.IPv6CanSend = true
|
|
rs.mu.Unlock()
|
|
}
|
|
default:
|
|
panic("bad probe proto " + fmt.Sprint(probe.proto))
|
|
}
|
|
c.vlogf("sent to %v", addr)
|
|
}
|
|
|
|
// proto is 4 or 6
|
|
// If it returns nil, the node is skipped.
|
|
func (c *Client) nodeAddr(ctx context.Context, n *tailcfg.DERPNode, proto probeProto) (ap netip.AddrPort) {
|
|
port := n.STUNPort
|
|
if port == 0 {
|
|
port = 3478
|
|
}
|
|
if port < 0 || port > 1<<16-1 {
|
|
return
|
|
}
|
|
if n.STUNTestIP != "" {
|
|
ip, err := netip.ParseAddr(n.STUNTestIP)
|
|
if err != nil {
|
|
return
|
|
}
|
|
if proto == probeIPv4 && ip.Is6() {
|
|
return
|
|
}
|
|
if proto == probeIPv6 && ip.Is4() {
|
|
return
|
|
}
|
|
return netip.AddrPortFrom(ip, uint16(port))
|
|
}
|
|
|
|
switch proto {
|
|
case probeIPv4:
|
|
if n.IPv4 != "" {
|
|
ip, _ := netip.ParseAddr(n.IPv4)
|
|
if !ip.Is4() {
|
|
return
|
|
}
|
|
return netip.AddrPortFrom(ip, uint16(port))
|
|
}
|
|
case probeIPv6:
|
|
if n.IPv6 != "" {
|
|
ip, _ := netip.ParseAddr(n.IPv6)
|
|
if !ip.Is6() {
|
|
return
|
|
}
|
|
return netip.AddrPortFrom(ip, uint16(port))
|
|
}
|
|
default:
|
|
return
|
|
}
|
|
|
|
// TODO(bradfitz): add singleflight+dnscache here.
|
|
addrs, _ := net.DefaultResolver.LookupIPAddr(ctx, n.HostName)
|
|
for _, a := range addrs {
|
|
if (a.IP.To4() != nil) == (proto == probeIPv4) {
|
|
na, _ := netip.AddrFromSlice(a.IP.To4())
|
|
return netip.AddrPortFrom(na.Unmap(), uint16(port))
|
|
}
|
|
}
|
|
return
|
|
}
|
|
|
|
func regionHasDERPNode(r *tailcfg.DERPRegion) bool {
|
|
for _, n := range r.Nodes {
|
|
if !n.STUNOnly {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
func maxDurationValue(m map[int]time.Duration) (max time.Duration) {
|
|
for _, v := range m {
|
|
if v > max {
|
|
max = v
|
|
}
|
|
}
|
|
return max
|
|
}
|
|
|
|
func conciseOptBool(b opt.Bool, trueVal string) string {
|
|
if b == "" {
|
|
return "_"
|
|
}
|
|
v, ok := b.Get()
|
|
if !ok {
|
|
return "x"
|
|
}
|
|
if v {
|
|
return trueVal
|
|
}
|
|
return ""
|
|
}
|
|
|
|
var (
|
|
metricNumGetReport = clientmetric.NewCounter("netcheck_report")
|
|
metricNumGetReportFull = clientmetric.NewCounter("netcheck_report_full")
|
|
metricNumGetReportError = clientmetric.NewCounter("netcheck_report_error")
|
|
|
|
metricSTUNSend4 = clientmetric.NewCounter("netcheck_stun_send_ipv4")
|
|
metricSTUNSend6 = clientmetric.NewCounter("netcheck_stun_send_ipv6")
|
|
metricSTUNRecv4 = clientmetric.NewCounter("netcheck_stun_recv_ipv4")
|
|
metricSTUNRecv6 = clientmetric.NewCounter("netcheck_stun_recv_ipv6")
|
|
metricHTTPSend = clientmetric.NewCounter("netcheck_https_measure")
|
|
)
|