NOTE: This driver has not been ported from
4.4BSD yet.
The
vv interface provides access to a 10 Mb/s Proteon proNET ring network.
The network address of the interface must be specified with an
SIOCSIFADDR ioctl(2) before data can be transmitted or received. It is only permissible to change the network address while the interface is marked “down”.
The host's hardware address is discovered by putting the interface in digital loopback mode (not joining the ring) and sending a broadcast packet from which the hardware address is extracted.
Transmit timeouts are detected through use of a watchdog routine. Lost input interrupts are checked for when packets are sent out.
If the installation is running CTL boards which use the old broadcast address of ‘0' instead of the new address of ‘0xff', the define
OLD_BROADCAST should be specified in the driver.
The driver can use “trailer” encapsulation to minimize copying data on input and output. This may be disabled, on a per-interface basis, by setting the
IFF_NOTRAILERS flag with an
SIOCSIFFLAGS ioctl(2).