Skip to content

Two Handhake initiation releated race-conditions fixed #48

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 2 commits into
base: master
Choose a base branch
from
Open

Two Handhake initiation releated race-conditions fixed #48

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
d164cb3
An attemt to fix handshakeAttempts atomic counter:
May 20, 2021
425aa97
Do not flood new HandshakeInitiations, if some is already in progress
May 20, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 9 additions & 3 deletions device/send.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -89,7 +89,7 @@ func (peer *Peer) SendKeepalive() {

func (peer *Peer) SendHandshakeInitiation(isRetry bool) error {
if !isRetry {
atomic.StoreUint32(&peer.timers.handshakeAttempts, 0)
atomic.StoreUint32(&peer.timers.handshakeAttempts, 1)
}

peer.handshake.mutex.RLock()
Expand Down Expand Up @@ -193,7 +193,10 @@ func (peer *Peer) keepKeyFreshSending() {
}
nonce := atomic.LoadUint64(&keypair.sendNonce)
if nonce > RekeyAfterMessages || (keypair.isInitiator && time.Since(keypair.created) > RekeyAfterTime) {
peer.SendHandshakeInitiation(false)
// Do not send new HandshakeInitiation, if handshake retry is already in progress
if !peer.handshakeInProgress() {
peer.SendHandshakeInitiation(false)
}
}
}

Expand Down Expand Up @@ -298,7 +301,10 @@ top:

keypair := peer.keypairs.Current()
if keypair == nil || atomic.LoadUint64(&keypair.sendNonce) >= RejectAfterMessages || time.Since(keypair.created) >= RejectAfterTime {
peer.SendHandshakeInitiation(false)
// Do not send new HandshakeInitiation, if handshake retry is already in progress
if !peer.handshakeInProgress() {
peer.SendHandshakeInitiation(false)
}
return
}

Expand Down
15 changes: 13 additions & 2 deletions device/timers.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -78,6 +78,9 @@ func expiredRetransmitHandshake(peer *Peer) {
if atomic.LoadUint32(&peer.timers.handshakeAttempts) > MaxTimerHandshakes {
peer.device.log.Verbosef("%s - Handshake did not complete after %d attempts, giving up", peer, MaxTimerHandshakes+2)

// Reset attempts count
atomic.StoreUint32(&peer.timers.handshakeAttempts, 0)

if peer.timersActive() {
peer.timers.sendKeepalive.Del()
}
Expand All @@ -95,7 +98,7 @@ func expiredRetransmitHandshake(peer *Peer) {
}
} else {
atomic.AddUint32(&peer.timers.handshakeAttempts, 1)
peer.device.log.Verbosef("%s - Handshake did not complete after %d seconds, retrying (try %d)", peer, int(RekeyTimeout.Seconds()), atomic.LoadUint32(&peer.timers.handshakeAttempts)+1)
peer.device.log.Verbosef("%s - Handshake did not complete after %d seconds, retrying (try %d)", peer, int(RekeyTimeout.Seconds()), atomic.LoadUint32(&peer.timers.handshakeAttempts))

/* We clear the endpoint address src address, in case this is the cause of trouble. */
peer.Lock()
Expand Down Expand Up @@ -141,10 +144,18 @@ func expiredPersistentKeepalive(peer *Peer) {
}
}

/* Returns true if HandshakeInitiation is already started (and not yet finished) */
func (peer *Peer) handshakeInProgress() bool {
return atomic.LoadUint32(&peer.timers.handshakeAttempts) > 0
}

/* Should be called after an authenticated data packet is sent. */
func (peer *Peer) timersDataSent() {
if peer.timersActive() && !peer.timers.newHandshake.IsPending() {
peer.timers.newHandshake.Mod(KeepaliveTimeout + RekeyTimeout + time.Millisecond*time.Duration(rand.Int31n(RekeyTimeoutJitterMaxMs)))
// Do not restart handshake because of staled data traffic, if it is already in progress
if !peer.handshakeInProgress() {
peer.timers.newHandshake.Mod(KeepaliveTimeout + RekeyTimeout + time.Millisecond*time.Duration(rand.Int31n(RekeyTimeoutJitterMaxMs)))
}
}
}

Expand Down