HDK Technical Reference

MDI ioctls

MDI ioctls are used to change the operation of and get information about the network adapter being driven by the MDI driver. They are sent by the MAC user in STREAMS messages of type M_IOCTL(D7str). For more information about STREAMS ioctl messages, see ``STREAMS ioctls''.

How a MDI ioctl is contained within STREAMS messages

The ioc_cmd member of the iocblk(D4str) structure conveys the IOCTL command to be processed.

When the MDI driver has finished processing the MDI ioctl, it must respond with either an M_IOCACK(D7str) or a M_IOCNAK(D7str) message type. If the processing was successful, then the MDI driver should respond by changing the original MDI ioctl request message in the following ways:

Change the db_type member of the first dblk_t to M_IOCACK
Set the ioc_error member to zero
Unless stated below, set the ioc_rval field to zero
Send the message upstream (back to the MAC user) Do not call freemsg(D3str) on the original M_IOCTL message because this causes important data identifying the M_IOCTL to be lost.

If the processing did not complete successfully, then the MDI driver should respond by changing the original MDI ioctl request in the following ways:

Change the db_type member of the first dblk_t to M_IOCNAK
Set the ioc_rval member to -1

Set the ioc_error member to an appropriate error value from those listed on errnos(D5).

Recommended values for ioc_error and their meanings

ioc_error Description

ENOSR Out of STREAMS resources

EINVAL parameter in the ioctl request was invalid

ENOSPC The multicast address table was full

EPERM Process does not have proper credentials to access this device

Send the message upstream (back to the MAC user)

ioc_error	Description
ENOSR	Out of STREAMS resources
EINVAL	parameter in the ioctl request was invalid
ENOSPC	The multicast address table was full
EPERM	Process does not have proper credentials to access this device

The following ioctls and associated processing are described in Section 7mdi manual pages. This manual page section documents the ioctls used in MDI drivers on both SVR5 and SCO OpenServer 5 systems. Check the manual pages for details about supported versions for each.

MACIOC_DELALLMCA(7mdi)

Only send frames sent upstream to a group address that is explicitly set with MACIOC_SETMCA (SVR5 only).

MACIOC_DELMCA(7mdi)

Requests that the MDI driver stop receiving frames sent to a multicast address. This is issued when the last DLS user issues the DL_DISABMULTI_REQ primitive.

MACIOC_GETADDR(7mdi)

Requests that the MDI driver return the current MAC address.

MACIOC_GETRADDR(7mdi)

Requests that the MDI driver return the factory MAC address.

MACIOC_GETMCA(7mdi)

Requests that the MDI driver return the active multicast address (SCO OpenServer 5 only).

MACIOC_GETMCSIZ(7mdi)

Requests that the MDI driver return the multicast address table size (SCO OpenServer 5 only).

MACIOC_GETSTAT(7mdi)

Requests that the MDI driver return media-specific statistics that contain information about the MDI driver, the network adapter and the network itself. Statistics structures are provided for:

Ethernet: mac_stats_eth(D4mdi)
Token Ring: mac_stats_tr(D4mdi)
FDDI: mac_stats_fddi(D4mdi)
ISDN: mac_stats_isdn(D4mdi)

MACIOC_PROMISC(7mdi)

Requests that the MDI driver enable promiscuous mode on the adapter.

MACIOC_SETADDR(7mdi)

Requests that the MDI driver set the MAC address (SCO OpenServer 5 only).

MACIOC_SETALLMCA(7mdi)

Receive/send frames sent to any group address upstream (SVR5 only).

MACIOC_SETMCA(7mdi)

Requests that the MDI driver begin receiving frames sent to the requested multicast address in addition to the adapter's unicast MAC address, broadcast address and existing multicast addresses.

MACIOC_SETSTAT(7mdi)

Requests that the MDI driver modify the MIB settable attributes related to the MDI driver, the network adapter and the network itself.

MACIOC_CLRSTAT(7mdi)

Requests that the MDI driver clear all the information collected in its statistics structure.