The mac_register() and mac_unregister() Functions

int mac_register(mac_register_t *mregp, mac_handle_t *mhp);

To register a new instance with the MAC layer, a GLDv3 driver must invoke the mac_register(9F) function in its attach(9E) entry point. The mregp argument is a pointer to a mac_register registration information structure. On success, the mhp argument is a pointer to a MAC handle for the new MAC instance. This handle is needed by other routines such as mac_tx_update(), mac_link_update(), and mac_rx().

Example 19–2 The mac_alloc(), mac_register(), and mac_free() Functions and mac_register Structure

int
xx_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
        mac_register_t        *macp;

/* ... */

        if ((macp = mac_alloc(MAC_VERSION)) == NULL) {
                xx_error(dip, "mac_alloc failed");
                goto failed;
        }

        macp->m_type_ident = MAC_PLUGIN_IDENT_ETHER;
        macp->m_driver = xxp;
        macp->m_dip = dip;
        macp->m_src_addr = xxp->xx_curraddr;
        macp->m_callbacks = &xx_m_callbacks;
        macp->m_min_sdu = 0;
        macp->m_max_sdu = ETHERMTU;
        macp->m_margin = VLAN_TAGSZ;

        if (mac_register(macp, &xxp->xx_mh) == DDI_SUCCESS) {
                mac_free(macp);
                return (DDI_SUCCESS);
        }

/* failed to register with MAC */
        mac_free(macp);
failed:
        /* ... */
}

int mac_unregister(mac_handle_t mh);

The mac_unregister(9F) function unregisters a MAC instance that was previously registered with mac_register(). The mh argument is the MAC handle that was allocated by mac_register(). Invoke mac_unregister() from the detach(9E) entry point.

Example 19–3 The mac_unregister() Function

int
xx_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
        xx_t        *xxp; /* driver soft state */

        /* ... */

        switch (cmd) {
        case DDI_DETACH:

                if (mac_unregister(xxp->xx_mh) != 0) {
                        return (DDI_FAILURE);
                }
        /* ... */
}