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TUN/TAP addr/subnet to Conn mappings, other fixes

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This commit is contained in:
Neil Alexander 2019-04-22 20:06:39 +01:00
parent 9778f5d2b8
commit ea8948f378
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GPG Key ID: A02A2019A2BB0944
3 changed files with 101 additions and 89 deletions
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67
src/tuntap/tun.go
View File

@ -39,7 +39,8 @@ type TunAdapter struct {
mtu int
iface *water.Interface
mutex sync.RWMutex // Protects the below
conns map[crypto.NodeID]*yggdrasil.Conn
addrToConn map[address.Address]*yggdrasil.Conn
subnetToConn map[address.Subnet]*yggdrasil.Conn
isOpen bool
}
@ -102,7 +103,8 @@ func (tun *TunAdapter) Init(config *config.NodeState, log *log.Logger, listener
tun.log = log
tun.listener = listener
tun.dialer = dialer
tun.conns = make(map[crypto.NodeID]*yggdrasil.Conn)
tun.addrToConn = make(map[address.Address]*yggdrasil.Conn)
tun.subnetToConn = make(map[address.Subnet]*yggdrasil.Conn)
}
// Start the setup process for the TUN/TAP adapter. If successful, starts the
@ -181,23 +183,40 @@ func (tun *TunAdapter) handler() error {
func (tun *TunAdapter) connReader(conn *yggdrasil.Conn) error {
remoteNodeID := conn.RemoteAddr()
tun.mutex.Lock()
if _, isIn := tun.conns[remoteNodeID]; isIn {
tun.mutex.Unlock()
return errors.New("duplicate connection")
remoteAddr := address.AddrForNodeID(&remoteNodeID)
remoteSubnet := address.SubnetForNodeID(&remoteNodeID)
err := func() error {
tun.mutex.RLock()
defer tun.mutex.RUnlock()
if _, isIn := tun.addrToConn[*remoteAddr]; isIn {
return errors.New("duplicate connection for address " + net.IP(remoteAddr[:]).String())
}
tun.conns[remoteNodeID] = conn
if _, isIn := tun.subnetToConn[*remoteSubnet]; isIn {
return errors.New("duplicate connection for subnet " + net.IP(remoteSubnet[:]).String())
}
return nil
}()
if err != nil {
//return err
panic(err)
}
// Store the connection mapped to address and subnet
tun.mutex.Lock()
tun.addrToConn[*remoteAddr] = conn
tun.subnetToConn[*remoteSubnet] = conn
tun.mutex.Unlock()
// Make sure to clean those up later when the connection is closed
defer func() {
tun.mutex.Lock()
delete(tun.conns, remoteNodeID)
delete(tun.addrToConn, *remoteAddr)
delete(tun.subnetToConn, *remoteSubnet)
tun.mutex.Unlock()
}()
b := make([]byte, 65535)
for {
n, err := conn.Read(b)
if err != nil {
tun.log.Errorln(conn.String(), "TUN/TAP conn read error:", err)
//tun.log.Errorln(conn.String(), "TUN/TAP conn read error:", err)
continue
}
if n == 0 {
@ -261,21 +280,28 @@ func (tun *TunAdapter) ifaceReader() error {
// For now don't deal with any non-Yggdrasil ranges
continue
}
dstNodeID, dstNodeIDMask = dstAddr.GetNodeIDandMask()
// Do we have an active connection for this node ID?
// Do we have an active connection for this node address?
tun.mutex.RLock()
conn, isIn := tun.conns[*dstNodeID]
conn, isIn := tun.addrToConn[dstAddr]
if !isIn || conn == nil {
conn, isIn = tun.subnetToConn[dstSnet]
if !isIn || conn == nil {
// Neither an address nor a subnet mapping matched, therefore populate
// the node ID and mask to commence a search
dstNodeID, dstNodeIDMask = dstAddr.GetNodeIDandMask()
}
}
tun.mutex.RUnlock()
// If we don't have a connection then we should open one
if !isIn {
if !isIn || conn == nil {
// Check we haven't been given empty node ID, really this shouldn't ever
// happen but just to be sure...
if dstNodeID == nil || dstNodeIDMask == nil {
panic("Given empty dstNodeID and dstNodeIDMask - this shouldn't happen")
}
// Dial to the remote node
if c, err := tun.dialer.DialByNodeIDandMask(dstNodeID, dstNodeIDMask); err == nil {
// We've been given a connection, so save it in our connections so we
// can refer to it the next time we send a packet to this destination
tun.mutex.Lock()
tun.conns[*dstNodeID] = &c
tun.mutex.Unlock()
// Start the connection reader goroutine
// We've been given a connection so start the connection reader goroutine
go tun.connReader(&c)
// Then update our reference to the connection
conn, isIn = &c, true
@ -285,9 +311,10 @@ func (tun *TunAdapter) ifaceReader() error {
continue
}
}
// If we have a connection now, try writing to it
if conn != nil {
// If we have an open connection, either because we already had one or
// because we opened one above, try writing the packet to it
if isIn && conn != nil {
w, err := conn.Write(bs[:n])
if err != nil {
tun.log.Errorln(conn.String(), "TUN/TAP conn write error:", err)

58
src/yggdrasil/conn.go
View File

@ -20,7 +20,6 @@ type Conn struct {
session *sessionInfo
readDeadline atomic.Value // time.Time // TODO timer
writeDeadline atomic.Value // time.Time // TODO timer
expired atomic.Value // bool
searching atomic.Value // bool
}
@ -30,39 +29,58 @@ func (c *Conn) String() string {
// This method should only be called from the router goroutine
func (c *Conn) startSearch() {
// The searchCompleted callback is given to the search
searchCompleted := func(sinfo *sessionInfo, err error) {
// Update the connection with the fact that the search completed, which
// allows another search to be triggered if necessary
c.searching.Store(false)
c.mutex.Lock()
defer c.mutex.Unlock()
// If the search failed for some reason, e.g. it hit a dead end or timed
// out, then do nothing
if err != nil {
c.core.log.Debugln(c.String(), "DHT search failed:", err)
c.expired.Store(true)
return
}
// Take the connection mutex
c.mutex.Lock()
defer c.mutex.Unlock()
// Were we successfully given a sessionInfo pointeR?
if sinfo != nil {
// Store it, and update the nodeID and nodeMask (which may have been
// wildcarded before now) with their complete counterparts
c.core.log.Debugln(c.String(), "DHT search completed")
c.session = sinfo
c.nodeID, c.nodeMask = sinfo.theirAddr.GetNodeIDandMask()
c.expired.Store(false)
c.nodeID = crypto.GetNodeID(&sinfo.theirPermPub)
for i := range c.nodeMask {
c.nodeMask[i] = 0xFF
}
} else {
c.core.log.Debugln(c.String(), "DHT search failed: no session returned")
c.expired.Store(true)
return
// No session was returned - this shouldn't really happen because we
// should always return an error reason if we don't return a session
panic("DHT search didn't return an error or a sessionInfo")
}
}
// doSearch will be called below in response to one or more conditions
doSearch := func() {
// Store the fact that we're searching, so that we don't start additional
// searches until this one has completed
c.searching.Store(true)
// Check to see if there is a search already matching the destination
sinfo, isIn := c.core.searches.searches[*c.nodeID]
if !isIn {
// Nothing was found, so create a new search
sinfo = c.core.searches.newIterSearch(c.nodeID, c.nodeMask, searchCompleted)
c.core.log.Debugf("%s DHT search started: %p", c.String(), sinfo)
}
// Continue the search
c.core.searches.continueSearch(sinfo)
}
// Take a copy of the session object, in case it changes later
c.mutex.RLock()
sinfo := c.session
c.mutex.RUnlock()
if c.session == nil {
// No session object is present so previous searches, if we ran any, have
// not yielded a useful result (dead end, remote host not found)
doSearch()
} else {
sinfo.worker <- func() {
@ -83,10 +101,6 @@ func (c *Conn) startSearch() {
}
func (c *Conn) Read(b []byte) (int, error) {
// If the session is marked as expired then do nothing at this point
if e, ok := c.expired.Load().(bool); ok && e {
return 0, errors.New("session is closed")
}
// Take a copy of the session object
c.mutex.RLock()
sinfo := c.session
@ -95,17 +109,15 @@ func (c *Conn) Read(b []byte) (int, error) {
// in a write, we would trigger a new session, but it doesn't make sense for
// us to block forever here if the session will not reopen.
// TODO: should this return an error or just a zero-length buffer?
if !sinfo.init {
if sinfo == nil || !sinfo.init {
return 0, errors.New("session is closed")
}
// Wait for some traffic to come through from the session
select {
// TODO...
case p, ok := <-c.recv:
// If the channel was closed then mark the connection as expired, this will
// mean that the next write will start a new search and reopen the session
// If the session is closed then do nothing
if !ok {
c.expired.Store(true)
return 0, errors.New("session is closed")
}
defer util.PutBytes(p.Payload)
@ -155,13 +167,9 @@ func (c *Conn) Write(b []byte) (bytesWritten int, err error) {
c.mutex.RLock()
sinfo := c.session
c.mutex.RUnlock()
// Check whether the connection is expired, if it is we can start a new
// search to revive it
expired, eok := c.expired.Load().(bool)
// If the session doesn't exist, or isn't initialised (which probably means
// that the session was never set up or it closed by timeout), or the conn
// is marked as expired, then see if we can start a new search
if sinfo == nil || !sinfo.init || (eok && expired) {
// that the search didn't complete successfully) then try to search again
if sinfo == nil || !sinfo.init {
// Is a search already taking place?
if searching, sok := c.searching.Load().(bool); !sok || (sok && !searching) {
// No search was already taking place so start a new one
@ -197,11 +205,9 @@ func (c *Conn) Write(b []byte) (bytesWritten int, err error) {
}
func (c *Conn) Close() error {
// Mark the connection as expired, so that a future read attempt will fail
// and a future write attempt will start a new search
c.expired.Store(true)
// Close the session, if it hasn't been closed already
c.session.close()
c.session = nil
// This can't fail yet - TODO?
return nil
}

35
src/yggdrasil/session.go
View File

@ -107,15 +107,6 @@ func (s *sessionInfo) update(p *sessionPing) bool {
return true
}
// Returns true if the session has been idle for longer than the allowed timeout.
func (s *sessionInfo) timedout() bool {
var timedout bool
s.doWorker(func() {
timedout = time.Since(s.time) > time.Minute
})
return timedout
}
// Struct of all active sessions.
// Sessions are indexed by handle.
// Additionally, stores maps of address/subnet onto keys, and keys onto handles.
@ -233,10 +224,6 @@ func (ss *sessions) isSessionAllowed(pubkey *crypto.BoxPubKey, initiator bool) b
// Gets the session corresponding to a given handle.
func (ss *sessions) getSessionForHandle(handle *crypto.Handle) (*sessionInfo, bool) {
sinfo, isIn := ss.sinfos[*handle]
if isIn && sinfo.timedout() {
// We have a session, but it has timed out
return nil, false
}
return sinfo, isIn
}
@ -280,8 +267,9 @@ func (ss *sessions) getByTheirSubnet(snet *address.Subnet) (*sessionInfo, bool)
return sinfo, isIn
}
// Creates a new session and lazily cleans up old/timedout existing sessions.
// This includse initializing session info to sane defaults (e.g. lowest supported MTU).
// Creates a new session and lazily cleans up old existing sessions. This
// includse initializing session info to sane defaults (e.g. lowest supported
// MTU).
func (ss *sessions) createSession(theirPermKey *crypto.BoxPubKey) *sessionInfo {
if !ss.isSessionAllowed(theirPermKey, true) {
return nil
@ -341,11 +329,6 @@ func (ss *sessions) cleanup() {
if time.Since(ss.lastCleanup) < time.Minute {
return
}
for _, s := range ss.sinfos {
if s.timedout() {
s.close()
}
}
permShared := make(map[crypto.BoxPubKey]*crypto.BoxSharedKey, len(ss.permShared))
for k, v := range ss.permShared {
permShared[k] = v
@ -387,7 +370,6 @@ func (sinfo *sessionInfo) close() {
delete(sinfo.core.sessions.addrToPerm, sinfo.theirAddr)
delete(sinfo.core.sessions.subnetToPerm, sinfo.theirSubnet)
close(sinfo.worker)
sinfo.init = false
}
// Returns a session ping appropriate for the given session info.
@ -465,17 +447,16 @@ func (ss *sessions) handlePing(ping *sessionPing) {
return
}
}
if !isIn || sinfo.timedout() {
if isIn {
sinfo.close()
}
if !isIn {
ss.createSession(&ping.SendPermPub)
sinfo, isIn = ss.getByTheirPerm(&ping.SendPermPub)
if !isIn {
panic("This should not happen")
}
ss.listenerMutex.Lock()
if ss.listener != nil {
// Check and see if there's a Listener waiting to accept connections
// TODO: this should not block if nothing is accepting
if !ping.IsPong && ss.listener != nil {
conn := &Conn{
core: ss.core,
session: sinfo,
@ -488,8 +469,6 @@ func (ss *sessions) handlePing(ping *sessionPing) {
conn.nodeMask[i] = 0xFF
}
ss.listener.conn <- conn
} else {
ss.core.log.Debugln("Received new session but there is no listener, ignoring")
}
ss.listenerMutex.Unlock()
}