fixed the issue of sending on closed channel

This commit fixes the issue of headscale crashing after sending on a
closed channel by moving the channel close to the sender side, instead
of the creator. closeChanWithLog is also implemented with generics now.

Fixes: https://github.com/juanfont/headscale/issues/342
Signed-off-by: Moritz Poldrack <git@moritz.sh>
This commit is contained in:
Moritz Poldrack 2022-04-10 00:37:13 +02:00
parent a92f6abc6e
commit 22dd61d849
No known key found for this signature in database
GPG key ID: 6A88F42508AB4FC6

68
poll.go
View file

@ -175,32 +175,13 @@ func (h *Headscale) PollNetMapHandler(ctx *gin.Context) {
Str("machine", machine.Name).
Msg("Loading or creating update channel")
// TODO: could probably remove all that duplication once generics land.
closeChanWithLog := func(channel interface{}, name string) {
log.Trace().
Str("handler", "PollNetMap").
Str("machine", machine.Name).
Str("channel", "Done").
Msg(fmt.Sprintf("Closing %s channel", name))
switch c := channel.(type) {
case (chan struct{}):
close(c)
case (chan []byte):
close(c)
}
}
const chanSize = 8
updateChan := make(chan struct{}, chanSize)
defer closeChanWithLog(updateChan, "updateChan")
pollDataChan := make(chan []byte, chanSize)
defer closeChanWithLog(pollDataChan, "pollDataChan")
defer closeChanWithLog(pollDataChan, machine.Name, "pollDataChan")
keepAliveChan := make(chan []byte)
defer closeChanWithLog(keepAliveChan, "keepAliveChan")
if req.OmitPeers && !req.Stream {
log.Info().
@ -273,7 +254,27 @@ func (h *Headscale) PollNetMapStream(
updateChan chan struct{},
) {
{
ctx, cancel := context.WithCancel(ctx.Request.Context())
machine, err := h.GetMachineByMachineKey(machineKey)
if err != nil {
if errors.Is(err, gorm.ErrRecordNotFound) {
log.Warn().
Str("handler", "PollNetMap").
Msgf("Ignoring request, cannot find machine with key %s", machineKey.String())
ctx.String(http.StatusUnauthorized, "")
return
}
log.Error().
Str("handler", "PollNetMap").
Msgf("Failed to fetch machine from the database with Machine key: %s", machineKey.String())
ctx.String(http.StatusInternalServerError, "")
return
}
ctx := context.WithValue(ctx.Request.Context(), "machineName", machine.Name)
ctx, cancel := context.WithCancel(ctx)
defer cancel()
go h.scheduledPollWorker(
@ -564,8 +565,8 @@ func (h *Headscale) PollNetMapStream(
func (h *Headscale) scheduledPollWorker(
ctx context.Context,
updateChan chan<- struct{},
keepAliveChan chan<- []byte,
updateChan chan struct{},
keepAliveChan chan []byte,
machineKey key.MachinePublic,
mapRequest tailcfg.MapRequest,
machine *Machine,
@ -573,6 +574,17 @@ func (h *Headscale) scheduledPollWorker(
keepAliveTicker := time.NewTicker(keepAliveInterval)
updateCheckerTicker := time.NewTicker(updateCheckInterval)
defer closeChanWithLog(
updateChan,
fmt.Sprint(ctx.Value("machineName")),
"updateChan",
)
defer closeChanWithLog(
keepAliveChan,
fmt.Sprint(ctx.Value("machineName")),
"updateChan",
)
for {
select {
case <-ctx.Done():
@ -606,3 +618,13 @@ func (h *Headscale) scheduledPollWorker(
}
}
}
func closeChanWithLog[C chan []byte | chan struct{}](channel C, machine, name string) {
log.Trace().
Str("handler", "PollNetMap").
Str("machine", machine).
Str("channel", "Done").
Msg(fmt.Sprintf("Closing %s channel", name))
close(channel)
}