mirror of
https://github.com/juanfont/headscale
synced 2026-04-25 17:15:33 +02:00
842f36225e
Blocked callers waiting on a pingTracker response channel would hang forever if the server Close()d mid-probe. Drain the pending map on Close so those goroutines unblock and exit cleanly. Updates #3157
112 lines
2.7 KiB
Go
112 lines
2.7 KiB
Go
package state
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import (
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"sync"
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"time"
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"github.com/juanfont/headscale/hscontrol/types"
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"github.com/juanfont/headscale/hscontrol/util"
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)
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const pingIDLength = 16
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// pingTracker correlates outgoing PingRequests with incoming HEAD
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// callbacks. Entries have no server-side TTL: callers are responsible
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// for cleaning up via CancelPing or by reading from the response channel
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// within their own timeout.
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type pingTracker struct {
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mu sync.Mutex
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pending map[string]*pendingPing
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}
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type pendingPing struct {
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nodeID types.NodeID
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startTime time.Time
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responseCh chan time.Duration
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}
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func newPingTracker() *pingTracker {
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return &pingTracker{
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pending: make(map[string]*pendingPing),
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}
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}
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// register creates a pending ping and returns a unique ping ID and a
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// channel that receives the round-trip latency once the response
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// arrives.
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func (pt *pingTracker) register(nodeID types.NodeID) (string, <-chan time.Duration) {
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pingID, _ := util.GenerateRandomStringDNSSafe(pingIDLength)
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ch := make(chan time.Duration, 1)
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pt.mu.Lock()
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pt.pending[pingID] = &pendingPing{
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nodeID: nodeID,
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startTime: time.Now(),
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responseCh: ch,
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}
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pt.mu.Unlock()
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return pingID, ch
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}
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// complete sends the measured latency on the response channel and
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// returns true. Returns false if the pingID is unknown (already
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// completed or cancelled).
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func (pt *pingTracker) complete(pingID string) bool {
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pt.mu.Lock()
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pp, ok := pt.pending[pingID]
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if ok {
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delete(pt.pending, pingID)
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}
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pt.mu.Unlock()
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if ok {
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pp.responseCh <- time.Since(pp.startTime)
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close(pp.responseCh)
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return true
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}
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return false
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}
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// cancel removes a pending ping without completing it. Idempotent.
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func (pt *pingTracker) cancel(pingID string) {
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pt.mu.Lock()
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delete(pt.pending, pingID)
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pt.mu.Unlock()
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}
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// drain closes every outstanding response channel and clears the map.
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// Called from State.Close to unblock any caller still waiting on a
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// channel that will never receive.
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func (pt *pingTracker) drain() {
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pt.mu.Lock()
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defer pt.mu.Unlock()
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for id, pp := range pt.pending {
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close(pp.responseCh)
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delete(pt.pending, id)
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}
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}
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// RegisterPing tracks a pending ping and returns its ID and a channel
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// for the latency. Callers must defer CancelPing or read the channel
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// within their own timeout; there is no server-side TTL.
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func (s *State) RegisterPing(nodeID types.NodeID) (string, <-chan time.Duration) {
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return s.pings.register(nodeID)
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}
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// CompletePing signals that a ping response arrived. Returns true if
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// the ID was known, false otherwise.
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func (s *State) CompletePing(pingID string) bool {
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return s.pings.complete(pingID)
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}
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// CancelPing removes a pending ping. Idempotent.
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func (s *State) CancelPing(pingID string) {
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s.pings.cancel(pingID)
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}
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