*** CID 358434: Null pointer dereferences (REVERSE_INULL)
/src/Cedar/Proto.c: 451 in ProtoHandleDatagrams()
445 void ProtoHandleDatagrams(UDPLISTENER *listener, LIST *datagrams)
446 {
447 UINT i;
448 HASH_LIST *sessions;
449 PROTO *proto = listener->Param;
450
>>> CID 358434: Null pointer dereferences (REVERSE_INULL)
>>> Null-checking "listener" suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
451 if (proto == NULL || listener == NULL || datagrams == NULL)
452 {
453 return;
454 }
455
456 sessions = proto->Sessions;
As a side effect, the DH parameter is now applied to the TCP server as well.
Previously, the default value was always used, ignoring the one from the configuration.
When a datagram is received, the matching session is looked up in a hash list; if it's not found, a new session is created.
This method allows to use a single UDP port for multiple protocols, as we do with TCP.
Also, each session has its own dedicated thread, used to process the received datagrams and generate the ones that are then sent through the UDP listener.
In addition to guaranteeing constant performance, separate threads also prevent a single one from blocking all sessions.
This allows to stop a UDP listener without deleting it.
It's especially useful when no datagrams should be received anymore, but there are other threads accessing the listener.
- An additional parameter is added to IsPacketForMe(), used to specify the protocol type (currently either TCP or UDP).
- SupportedModes() is dropped because it's now redundant.
- IsOk() and EstablishedSessions() are dropped because error checking should be handled by the implementation.
- ProtoImplDetect() now takes a buffer and its size rather than a SOCK, so that it can be used to detect UDP protocols.
- The OpenVPN toggle check is moved to ProtoImplDetect(), so that we don't have to duplicate it once UDP support is implemented.
The PROTO structure is now used to identify the system as a whole, rather than a single protocol. It's stored and initialized in Server.
ProtoCompare(), ProtoAdd() and ProtoDetected() are renamed to make the difference between PROTO and PROTO_IMPL more clear.
ProtoGet() and ProtoNum() are removed because the related list can now be accessed directly by Server.
From https://community.openvpn.net/openvpn/wiki/Openvpn23ManPage:
--block-outside-dns
Block DNS servers on other network adapters to prevent DNS leaks.
This option prevents any application from accessing TCP or UDP port 53 except one inside the tunnel.
It uses Windows Filtering Platform (WFP) and works on Windows Vista or later.
This option is considered unknown on non-Windows platforms and unsupported on Windows XP, resulting in fatal error.
You may want to use --setenv opt or --ignore-unknown-option (not suitable for Windows XP) to ignore said error.
Note that pushing unknown options from server does not trigger fatal errors.
