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package l2tp
import (
"fmt"
"sync"
"time"
"github.com/go-kit/kit/log"
"github.com/go-kit/kit/log/level"
"golang.org/x/sys/unix"
)
type quiescentTunnel struct {
*baseTunnel
sal, sap unix.Sockaddr
cp *controlPlane
xport *transport
dp TunnelDataPlane
closeChan chan bool
wg sync.WaitGroup
}
func (qt *quiescentTunnel) NewSession(name string, cfg *SessionConfig) (Session, error) {
// Must have configuration
if cfg == nil {
return nil, fmt.Errorf("invalid nil config")
}
// Duplicate the configuration so we don't modify the user's copy
myCfg := *cfg
if _, ok := qt.findSessionByName(name); ok {
return nil, fmt.Errorf("already have session %q", name)
}
if _, ok := qt.findSessionByID(cfg.SessionID); ok {
return nil, fmt.Errorf("already have session %q", cfg.SessionID)
}
s, err := newStaticSession(name, qt, &myCfg)
if err != nil {
return nil, err
}
qt.linkSession(s)
return s, nil
}
func (qt *quiescentTunnel) Close() {
if qt != nil {
close(qt.closeChan)
qt.wg.Wait()
qt.close()
}
}
func (qt *quiescentTunnel) close() {
if qt != nil {
qt.baseTunnel.closeAllSessions()
if qt.xport != nil {
qt.xport.close()
}
if qt.cp != nil {
qt.cp.close()
}
if qt.dp != nil {
err := qt.dp.Down()
level.Error(qt.logger).Log("message", "dataplane down failed", "error", err)
}
qt.parent.unlinkTunnel(qt)
level.Info(qt.logger).Log("message", "close")
}
}
func (qt *quiescentTunnel) xportReader() {
// Although we're not running the control protocol we do need
// to drain messages from the transport to avoid the receive
// path blocking.
defer qt.wg.Done()
for {
select {
case <-qt.closeChan:
return
case _, ok := <-qt.xport.recvChan:
if !ok {
qt.close()
return
}
}
}
}
func newQuiescentTunnel(name string, parent *Context, sal, sap unix.Sockaddr, cfg *TunnelConfig) (qt *quiescentTunnel, err error) {
qt = &quiescentTunnel{
baseTunnel: newBaseTunnel(
log.With(parent.logger, "tunnel_name", name),
name,
parent,
cfg),
sal: sal,
sap: sap,
closeChan: make(chan bool),
}
// Initialise the control plane.
// We bind/connect immediately since we're not runnning most of the control protocol.
qt.cp, err = newL2tpControlPlane(sal, sap)
if err != nil {
qt.Close()
return nil, err
}
err = qt.cp.bind()
if err != nil {
qt.Close()
return nil, err
}
err = qt.cp.connect()
if err != nil {
qt.Close()
return nil, err
}
qt.dp, err = parent.dp.NewTunnel(qt.cfg, qt.sal, qt.sap, qt.cp.fd)
if err != nil {
qt.Close()
return nil, err
}
qt.xport, err = newTransport(qt.logger, qt.cp, transportConfig{
HelloTimeout: qt.cfg.HelloTimeout,
TxWindowSize: qt.cfg.WindowSize,
MaxRetries: qt.cfg.MaxRetries,
RetryTimeout: qt.cfg.RetryTimeout,
AckTimeout: time.Millisecond * 100,
Version: qt.cfg.Version,
PeerControlConnID: qt.cfg.PeerTunnelID,
})
if err != nil {
qt.Close()
return nil, err
}
qt.wg.Add(1)
go qt.xportReader()
level.Info(qt.logger).Log(
"message", "new quiescent tunnel",
"version", qt.cfg.Version,
"encap", qt.cfg.Encap,
"local", qt.cfg.Local,
"peer", qt.cfg.Peer,
"tunnel_id", qt.cfg.TunnelID,
"peer_tunnel_id", qt.cfg.PeerTunnelID)
return
}
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