SoftEther VPN originally created the NIC in the UP state and never changed it, even when the the client was not connected.
The behavior was changed in 59e1483dbf, which also added the NicDownOnDisconnect option
The option was disabled by default for backwards compatibility with scripts that don't check whether the NIC is down, but it's not ideal.
This commit forces the correct behavior and removes the commands "TUNDownOnDisconnectEnable", "TUNDownOnDisconnectDisable" and "TUNDownOnDisconnectGet".
PortsUDPSet: This command can be used to specify a single or multiple UDP ports the server should listen on. "0" can be specified to disable the UDP listener.
Administrator privileges are required to execute the command.
PortsUDPGet: This command can be used to retrieve the UDP ports the server is listening on.
The two commands replace the functionality that was previously provided by OpenVpnEnable and OpenVpnGet, respectively.
Originally, StrToPortList() returned NULL when it encountered a number equal to 0 or higher than 65535.
This commit adds a new parameter to the function called "limit_range":
- When its value is true, the function retains the original behavior.
- When its value is false, the function doesn't check whether the number is in the network port number range (1-65535).
The change is required because the command to set the UDP ports will allow to remove all ports by specifying "0" as the port number.
Now that Proto supports UDP, the server can handle multiple protocols on each UDP port.
The UDP ports are specified by the "OpenVPN_UdpPortList" configuration setting, because:
- OpenVPN is currently the only UDP protocol supported by SoftEther VPN to allow a custom port number.
- Before Proto was introduced, a unified interface for the protocols didn't exist; each protocol implementation had to create its own listener.
In preparation for the upcoming WireGuard implementation, this commit renames "OpenVPN_UdpPortList" to "PortsUDP", which should clarify that the setting is global.
The change is reflected in the code. Also, the ports are now stored in a LIST rather than a string. The conversion between string and LIST only happens when loading/saving the configuration.
The default UDP ports are now the same as the TCP ones (443, 992, 1194, 5555).
*** 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.
