mirror of
https://github.com/tailscale/tailscale.git
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3114a1c88d
Co-authored-by: Val <valerie@tailscale.com> Signed-off-by: Anton Tolchanov <anton@tailscale.com>
156 lines
3.9 KiB
Go
156 lines
3.9 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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package derphttp
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import (
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"context"
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"net/netip"
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"sync"
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"time"
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"tailscale.com/derp"
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"tailscale.com/types/key"
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"tailscale.com/types/logger"
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)
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var retryInterval = 5 * time.Second
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// RunWatchConnectionLoop loops until ctx is done, sending
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// WatchConnectionChanges and subscribing to connection changes.
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//
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// If the server's public key is ignoreServerKey, RunWatchConnectionLoop
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// returns.
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//
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// Otherwise, the add and remove funcs are called as clients come & go.
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//
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// infoLogf, if non-nil, is the logger to write periodic status updates about
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// how many peers are on the server. Error log output is set to the c's logger,
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// regardless of infoLogf's value.
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//
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// To force RunWatchConnectionLoop to return quickly, its ctx needs to be
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// closed, and c itself needs to be closed.
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//
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// It is a fatal error to call this on an already-started Client withoutq having
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// initialized Client.WatchConnectionChanges to true.
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func (c *Client) RunWatchConnectionLoop(ctx context.Context, ignoreServerKey key.NodePublic, infoLogf logger.Logf, add func(key.NodePublic, netip.AddrPort), remove func(key.NodePublic)) {
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if !c.WatchConnectionChanges {
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if c.isStarted() {
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panic("invalid use of RunWatchConnectionLoop on already-started Client without setting Client.RunWatchConnectionLoop")
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}
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c.WatchConnectionChanges = true
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}
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if infoLogf == nil {
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infoLogf = logger.Discard
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}
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logf := c.logf
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const statusInterval = 10 * time.Second
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var (
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mu sync.Mutex
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present = map[key.NodePublic]bool{}
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loggedConnected = false
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)
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clear := func() {
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mu.Lock()
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defer mu.Unlock()
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if len(present) == 0 {
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return
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}
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logf("reconnected; clearing %d forwarding mappings", len(present))
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for k := range present {
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remove(k)
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}
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present = map[key.NodePublic]bool{}
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}
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lastConnGen := 0
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lastStatus := c.clock.Now()
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logConnectedLocked := func() {
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if loggedConnected {
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return
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}
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infoLogf("connected; %d peers", len(present))
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loggedConnected = true
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}
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const logConnectedDelay = 200 * time.Millisecond
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timer := c.clock.AfterFunc(2*time.Second, func() {
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mu.Lock()
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defer mu.Unlock()
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logConnectedLocked()
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})
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defer timer.Stop()
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updatePeer := func(k key.NodePublic, ipPort netip.AddrPort, isPresent bool) {
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if isPresent {
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add(k, ipPort)
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} else {
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remove(k)
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}
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mu.Lock()
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defer mu.Unlock()
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if isPresent {
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present[k] = true
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if !loggedConnected {
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timer.Reset(logConnectedDelay)
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}
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} else {
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// If we got a peerGone message, that means the initial connection's
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// flood of peerPresent messages is done, so we can log already:
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logConnectedLocked()
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delete(present, k)
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}
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}
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sleep := func(d time.Duration) {
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t, tChannel := c.clock.NewTimer(d)
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select {
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case <-ctx.Done():
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t.Stop()
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case <-tChannel:
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}
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}
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for ctx.Err() == nil {
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if c.ServerPublicKey() == ignoreServerKey {
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logf("detected self-connect; ignoring host")
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return
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}
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for {
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m, connGen, err := c.RecvDetail()
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if err != nil {
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clear()
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logf("Recv: %v", err)
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sleep(retryInterval)
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break
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}
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if connGen != lastConnGen {
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lastConnGen = connGen
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clear()
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}
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switch m := m.(type) {
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case derp.PeerPresentMessage:
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updatePeer(m.Key, m.IPPort, true)
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case derp.PeerGoneMessage:
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switch m.Reason {
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case derp.PeerGoneReasonDisconnected:
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// Normal case, log nothing
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case derp.PeerGoneReasonNotHere:
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logf("Recv: peer %s not connected to %s",
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key.NodePublic(m.Peer).ShortString(), c.ServerPublicKey().ShortString())
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default:
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logf("Recv: peer %s not at server %s for unknown reason %v",
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key.NodePublic(m.Peer).ShortString(), c.ServerPublicKey().ShortString(), m.Reason)
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}
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updatePeer(key.NodePublic(m.Peer), netip.AddrPort{}, false)
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default:
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continue
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}
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if now := c.clock.Now(); now.Sub(lastStatus) > statusInterval {
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lastStatus = now
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infoLogf("%d peers", len(present))
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}
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}
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}
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}
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