IOCINFO (Describe Device) tokioctl Token-Ring Device Handler Operation

Kernel and Subsystems Technical Reference, Volume 2

IOCINFO (Describe Device) tokioctl Token-Ring Device Handler Operation

Purpose

Returns a structure that describes the token-ring device.

Description

The IOCINFO tokioctl operation returns a structure that describes the token-ring device. For this operation, the arg parameter points to the devinfo structure. This structure is defined in the /usr/include/sys/devinfo.h file and contains the following fields:

`devtype`	Identifies the device type. The token-ring device type is DD_NET_DH. This value is defined in the /usr/include/sys/devinfo.h file.
`devsubtype`	Identifies the device subtype. The token-ring device subtype is DD_TR. This value is defined in the /usr/include/sys/devinfo.h file.
`speed`	Specifies the capabilities of the token-ring device. This is equal to TOK_4M when the token-ring device is configured with a data rate of 4 Mbps. The capabilities are TOK_16M when the token-ring device is configured with a data rate of 16 Mbps. The TOK_4M and TOK_16M labels are defined in the /usr/include/sys/tokuser.h file.
`broad_wrap`	Specifies whether the wrapping of broadcast packets is supported by the device.
`rdto`	Specifies the configured receive data transfer offset (RDTO) value.
`haddr`	Specifies the 6-byte hardware address of the token-ring adapter card.
`net_addr`	Specifies the 6-byte network address currently used by the token-ring device handler.

The parameter block is filled in with the appropriate values upon return.

Execution Environment

The IOCINFO tokioctl operation can be called from the process environment only.

Return Values

EFAULT	Indicates the specified address is not valid.
EINVAL	Indicates a parameter is not valid.
ENXIO	Indicates the specified minor number is not valid.

Implementation Specifics

The IOCINFO operation functions with a Token-Ring High-Performance Network Adapter that has been correctly configured for use on a qualified network. Consult adapter specifications for more information on configuring the adapter and network qualifications.

Related Information

The tokioctl entry point.