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TLS: Avoid accessing non-atomic listener socket flags during HS

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This commit ensures that the non-atomic flags inside a TLS listener
socket object (and associated worker) are accessed when doing
handshake for a connection only from within the context of the
dedicated thread, but not other worker threads.

The purpose of this commit is to avoid TSAN errors during
isc__nmsocket_closing() calls. It is a continuation of
4b5559cd8f.
This commit is contained in:
Artem Boldariev 2022-12-01 22:42:54 +02:00
parent fc991fa79d
commit 4d0c226375
1 changed files with 24 additions and 1 deletions
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25
lib/isc/netmgr/tlsstream.c
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@ -351,7 +351,30 @@ tls_try_handshake(isc_nmsocket_t *sock, isc_result_t *presult) {
tlshandle = isc__nmhandle_get(sock, &sock->peer, &sock->iface);
tls_read_stop(sock);
if (sock->tlsstream.server) {
if (isc__nmsocket_closing(sock->listener)) {
/*
* We need to check for 'sock->listener->closing' to
* make sure that we are not breaking the contract by
* calling an accept callback after the listener socket
* was shot down. Also, in this case the accept callback
* can be 'NULL'. That can happen as calling the accept
* callback in TLS is deferred until handshake is done.
* There is a possibility for that to happen *after* the
* underlying TCP connection was accepted. That is, a
* situation possible when the underlying TCP connection
* was accepted, handshake related data transmission
* took place, but in the middle of that the socket is
* being shot down before the TLS accept callback could
* have been called.
*
* Also see 'isc__nmsocket_stop()' - the function used
* to shut down the listening TLS socket - for more
* details.
*/
if (isc__nm_closing(sock->worker)) {
result = ISC_R_SHUTTINGDOWN;
} else if (isc__nmsocket_closing(sock) ||
atomic_load(&sock->listener->closing))
{
result = ISC_R_CANCELED;
} else {
result = sock->listener->accept_cb(