MAC_REGISTER(9S) Data Structures for Drivers MAC_REGISTER(9S)

mac_register, mac_register_t
networking device driver registration structure

#include <sys/mac_provider.h>
#include <sys/mac_ether.h>

illumos DDI specific

The mac_register structure is used by GLDv3 networking device drivers implementing the mac(9E) interface.

The structure is allocated by a call to mac_alloc(9F) after which the various structure members should be set. Once they have been set, the structure can be used by a GLDv3 device driver to register with the MAC framework by calling the mac_register(9F) function. Once mac_register(9F) has been called, the structure can be freed through a call to mac_free(9F).

uint_t                  m_version;
const char              *m_type_ident;
void                    *m_driver;
dev_info_t              *m_dip;
uint_t                  m_instance;
uint8_t                 *m_src_addr;
uint8_t                 *m_dst_addr;
mac_callbacks_t         *m_callbacks;
uint_t                  m_min_sdu;
uint_t                  m_max_sdu;
void                    *m_pdata;
size_t                  m_pdata_size;
char                    **m_priv_props;
uint32_t                m_margin;

The m_version member is set during a call to mac_alloc(9F). Device drivers should not modify this field.

The m_type_ident member identifies the kind of networking device that this driver represents. The following constants should be used to identify the device type:

MAC_PLUGIN_IDENT_ETHER
The device driver implements IEEE 802.3 Ethernet.

The m_driver value is a private value that the device driver may set and will be provided as an argument in many of the mac(9E) callbacks. Most often this is set to the driver's soft state for a specific instance.

The m_dip member should point to the device driver's dev_info structure for that specific instance. This structure is provided during the driver's attach(9E) entry point.

The m_instance member should be set to zero. The GLDv3 framework will determine the appropriate instance.

The m_src_addr member should be set to a byte array that describes the source MAC address of the device. This is usually the default MAC address as programmed by the device manufacturer in that instance of the device.

The m_dst_addr member is an optional property and should be set to NULL by most device drivers. If set, this address will be the destination for outgoing frames.

The m_callbacks member contains the GLDv3 entry points implemented by the device driver. See mac_callbacks(9S) for a full explanation of the structure, its members, and their responsibilities. See mac(9E) for a broader picture of how the entry points are used.

The m_min_sdu property is the minimum service data unit. It represents the minimum size packet that the device can transmit, ignoring its own headers. Thus for an Ethernet device, this value would exclude the Ethernet header and any VLAN headers. If this is set to zero, then that means that either the MAC protocol does not require a minimum size or that the device driver and hardware will ensure that any minimum size is taken care of.

The m_max_sdu property is the maximum service data unit. It represents the maximum size packet that the device can transmit, ignoring its own headers. For an Ethernet based device, this would exclude the size of the Ethernet header and a VLAN headers. This value is often called the maximum transmission unit (MTU).

The m_pdata member is used for data specific to the type specified in the m_type_ident member. For all devices of type MAC_PLUGIN_IDENT_ETHER, this should be set to NULL.

The m_pdata_size member indicates the size of the member m_pdata. For all devices of type MAC_PLUGIN_IDENT_ETHER, this should be set to 0.

The m_priv_props member is an optional member that lists device-specific properties. These properties will be queried through functions like mc_getprop(9E), mc_propinfo(9E), and mc_setprop(9E). If the driver does not have any private properties, it should be set to NULL. Otherwise, it should be set to a NULL-terminated array of character strings where each entry is the name of a distinct property. See mac(9E) for more information on private properties.

The m_margin property indicates the amount of additional bytes of information that may be included beyond the basic MAC header. For example, with an Ethernet device, if the hardware supports a VLAN tag, then this property would be set to the size of a VLAN tag, indicating that it supported the additional bytes in a single packet beyond the Ethernet header and the m_max_sdu.

attach(9E), mac(9E), mac_alloc(9F), mac_free(9F), mac_register(9F), mac_callbacks(9S)
May 10, 2016 OmniOS