device driversnetwork drivers GLDdrivers network driversusing GLD Solaris network drivers are STREAMS-based. These types of drivers are covered in depth in the STREAMS Programming Guide. This chapter discusses the Generic LAN driver (GLD), which is a kernel module encapsulating features common to most network drivers. The GLD implements much of the STREAMS and Data Link Provider Interface (DLPI) functionality for a Solaris network driver.The GLD module is available for Solaris network drivers for the SPARC platform and for both 32-bit and 64-bit x86 platforms.This chapter provides information on the following subjects:Generic LAN Driver Overview Declarations and Data Structures GLD Arguments GLD Entry Points GLD Service Routines For more information on GLDs, see the gld7D, dlpi7P, gld9E, gld9F, gld_mac_info9S, and gld_stats9S man pages. STREAMSsupport for network driverGLD is a multi-threaded, clonable, loadable kernel module providing support to device drivers for local area networks. Local area network (LAN) device drivers in the Solaris OS are STREAMS-based drivers that use DLPI to communicate with network protocol stacks. These protocol stacks use the network drivers to send and receive packets on a local area network.A network device driver must implement and conform to these requirements:DDI/DKI specification STREAMS specification DLPI specification programmatic interface for the device GLD implements most STREAMS and DLPI functionality required of a Solaris LAN driver. Several Solaris network drivers are implemented using GLD.attach entry pointnetwork driversgld9E entry pointnetwork drivergld_mac_info structurenetwork driversgld9F functionA Solaris network driver that is implemented using GLD is made up of two distinct parts: a generic component that deals with STREAMS and DLPI interfaces, and a device-specific component that deals with the particular hardware device. The device-specific module indicates its dependency on the GLD module, which is found at /kernel/misc/gld. The device-specific module then registers with GLD from within the driver's attach9E function. After the device-specific module is successfully loaded, the driver is DLPI-compliant. The device-specific part of the driver calls gld9F functions when that part receives data or needs some service from GLD. When the device-specific driver registers with the GLD, the driver provides pointers to the entry points for later use by GLD. GLD makes calls into the gld9E using these pointers. The gld_mac_info9S structure is the main data interface between GLD and the device-specific driver.The GLD facility currently supports the following types of devices:DL_ETHER, that is, ISO 8802-3, IEEE 802.3 protocol DL_TPR, that is, IEEE 802.5, Token Passing Ring DL_FDDI, that is, ISO 9314-2, Fibre Distributed Data Interface GLDdevice types supported byDL_ETHERGLD supportDL_TPRGLD supportDL_FDDIGLD supportIEEE 802.3DL_ETHERIEEE 802.5DL_TPRISO 8802-3DL_ETHERISO 9314-2DL_TPRGLD drivers are expected to process fully formed MAC-layer packets and should not perform logical link control (LLC) handling.In some cases, a full DLPI-compliant driver can be implemented without using the GLD facility. One case would be devices that are not ISO 8802-style, that is, IEEE 802, LAN devices. Another case would be devices or services that are not supported by GLD.DL_ETHERGLD support DL_ETHEREthernet V2 packet processing packet processingEthernet V2 DL_ETHERISO 8802-3 (IEEE 802.3) packet processing packet processingISO 8802-3 (IEEE 802.3) SAPdefinition ofFor devices designated type DL_ETHER, GLD provides support for both Ethernet V2 and ISO 8802-3 (IEEE 802.3) packet processing. Ethernet V2 enables a user to access a conforming provider of data link services without special knowledge of the provider's protocol. A service access point (SAP) is the point through which the user communicates with the service provider.Streams bound to SAP values in the range [0-255] are treated as equivalent and denote that the user wants to use 8802-3 mode. If the SAP value of the DL_BIND_REQ is within this range, GLD computes the length of each subsequent DL_UNITDATA_REQ message on that stream. The length does not include the 14-byte media access control (MAC) header. GLD then transmits 8802-3 frames that have those lengths in the MAC frame header type fields. Such lengths never exceed 1500.All frames that are received from the media that have a type field in the range [0-1500] are assumed to be 8802-3 frames. These frames are routed up all open streams in 8802-3 mode. Those streams with SAP values in the [0-255] range are considered to be in 8802-3 mode. If more than one stream is in 8802-3 mode, the incoming frame is duplicated and routed up these streams.Those streams that are bound to SAP values that are greater than 1500 are assumed to be in Ethernet V2 mode. These streams receive incoming packets whose Ethernet MAC header type value exactly matches the value of the SAP to which the stream is bound. DL_TPRGLD support DL_FDDIGLD support DL_TPRSNAP processing DL_FDDISNAP processing SNAPdefinition ofSNAPDL_TPRSNAPDL_FDDIFor media types DL_TPR and DL_FDDI, GLD implements minimal SNAP (Sub-Net Access Protocol) processing. This processing is for any stream that is bound to a SAP value that is greater than 255. SAP values in the range [0-255] are LLC SAP values. Such values are carried naturally by the media packet format. SAP values that are greater than 255 require a SNAP header, subordinate to the LLC header, to carry the 16-bit Ethernet V2-style SAP value.SNAP headers are carried under LLC headers with destination SAP 0xAA. Outbound packets with SAP values that are greater than 255 require an LLC+SNAP header take the following form:AA AA 03 00 00 00 XX XX``XX XX'' represents the 16-bit SAP, corresponding to the Ethernet V2 style ``type.'' This header is unique in supporting non-zero organizational unique identifier fields. LLC control fields other than 03 are considered to be LLC packets with SAP 0xAA. Clients wanting to use SNAP formats other than this format must use LLC and bind to SAP 0xAA.Incoming packets are checked for conformance with the above format. Packets that conform are matched to any streams that have been bound to the packet's 16-bit SNAP type. In addition, these packets are considered to match the LLC SNAP SAP 0xAA.Packets received for any LLC SAP are passed up all streams that are bound to an LLC SAP, as described for media type DL_ETHER. DL_TPRGLD support DL_TPRsource routing For type DL_TPR devices, GLD implements minimal support for source routing. Source routing support includes the following items:Specify routing information for a packet to be sent across a bridged medium. The routing information is stored in the MAC header. This information is used to determine the route. Learn routes. Solicit and respond to requests for information about possible multiple routes Select among available routes. Source routing adds routing information fields to the MAC headers of outgoing packets. In addition, this support recognizes such fields in incoming packets.GLD's source routing support does not implement the full route determination entity (RDE) specified in Section 9 of ISO 8802-2 (IEEE 802.2). However, this support can interoperate with any RDE implementations that might exist in the same or a bridged network. DLPI providers Style 1 DLPI provider Style 2 DLPI provider open entry pointnetwork driversDLPI primitivesDL_ATTACH_REQGLD implements both Style 1 and Style 2 DLPI providers. A physical point of attachment (PPA) is the point at which a system attaches itself to a physical communication medium. All communication on that physical medium funnels through the PPA. The Style 1 provider attaches the streams to a particular PPA based on the major or minor device that has been opened. The Style 2 provider requires the DLS, that is, the data link service, user to explicitly identify the desired PPA using DL_ATTACH_REQ. In this case, open9E creates a stream between the user and GLD, and DL_ATTACH_REQ subsequently associates a particular PPA with that stream. Style 2 is denoted by a minor number of zero. If a device node whose minor number is not zero is opened, Style 1 is indicated and the associated PPA is the minor number minus 1. In both Style 1 and Style 2 opens, the device is cloned. DLPI primitives DLPI primitivesDL_INFO_REQDLPI primitivesDL_INFO_ACKGLD implements several DLPI primitives. The DL_INFO_REQ primitive requests information about the DLPI streams. The message consists of one M_PROTO message block. GLD returns device-dependent values in the DL_INFO_ACK response to this request. These values are based on information that the GLD-based driver specified in the gldm_mac_info9S structure that was passed to gld_register.GLD returns the following values on behalf of all GLD-based drivers:DLPI symbolsDL_VERSION_2DL_VERSION_2DLPI symbolsVersion is DL_VERSION_2 DLPI symbolsDL_CLDLSDL_CLDLSDLPI symbolsService mode is DL_CLDLS, GLD implements connectionless-mode service. DLPI symbolsDL_STYLE1DL_STYLE1DLPI symbolsDLPI symbolsDL_STYLE2DL_STYLE2DLPI symbolsProvider style is DL_STYLE1 or DL_STYLE2, depending on how the stream was opened. No optional Quality of Service (QOS) support is present. The QOS fields are zero. Contrary to the DLPI specification, GLD returns the device's correct address length and broadcast address in DL_INFO_ACK even before the stream has been attached to a PPA. DLPI primitivesDL_ATTACH_REQDLPI primitivesDL_UNATTACHED_REQThe DL_ATTACH_REQ primitive is used to associate a PPA with a stream. This request is needed for Style 2 DLS providers to identify the physical medium over which the communication is sent. Upon completion, the state changes from DL_UNATTACHED to DL_UNBOUND. The message consists of one M_PROTO message block. This request is not allowed when Style 1 mode is used. Streams that are opened using Style 1 are already attached to a PPA by the time the open completes.DLPI primitivesDL_DETACH_REQDLPI primitivesDL_DETACH_REQThe DL_DETACH_REQ primitive requests to detach the PPA from the stream. This detachment is allowed only if the stream was opened using Style 2.DLPI primitivesDL_BIND_REQDLPI primitivesDL_UNBIND_REQDLPI primitivesDL_BIND_REQDLPI primitivesDL_UNBIND_REQThe DL_BIND_REQ and DL_UNBIND_REQ primitives bind and unbind a DLSAP (data link service access point) to the stream. The PPA that is associated with a stream completes initialization before the completion of the processing of the DL_BIND_REQ on that stream. You can bind multiple streams to the same SAP. Each stream in this case receives a copy of any packets that were received for that SAP.DLPI primitivesDL_ENABMULTI_REQDLPI primitivesDL_DISABMULTI_REQDLPI primitivesDL_ENABMULTI_REQDLPI primitivesDL_DISABMULTI_REQThe DL_ENABMULTI_REQ and DL_DISABMULTI_REQ primitives enable and disable reception of individual multicast group addresses. Through iterative use of these primitives, an application or other DLS user can create or modify a set of multicast addresses. The streams must be attached to a PPA for these primitives to be accepted.DLPI primitivesDL_PROMISCON_REQDLPI primitivesDL_PROMISCOFF_REQDLPI primitivesDL_PROMISCON_REQDLPI primitivesDL_PROMISCOFF_REQThe DL_PROMISCON_REQ and DL_PROMISCOFF_REQ primitives turn promiscuous mode on or off on a per-stream basis. These controls operate at either at a physical level or at the SAP level. The DL Provider routes all received messages on the media to the DLS user. Routing continues until a DL_DETACH_REQ is received, a DL_PROMISCOFF_REQ is received, or the stream is closed. You can specify physical level promiscuous reception of all packets on the medium or of multicast packets only.The streams must be attached to a PPA for these promiscuous mode primitives to be accepted. DLPI primitivesDL_UNITDATA_REQThe DL_UNITDATA_REQ primitive is used to send data in a connectionless transfer. Because this service is not acknowledged, delivery is not guaranteed. The message consists of one M_PROTO message block followed by one or more M_DATA blocks containing at least one byte of data.DLPI primitivesDL_UNITDATA_INDThe DL_UNITDATA_IND type is used when a packet is to be passed on upstream. The packet is put into an M_PROTO message with the primitive set to DL_UNITDATA_IND.DLPI primitivesDL_PHYS_ADDR_REQDLPI primitivesDL_PHYS_ADDR_ACKThe DL_PHYS_ADDR_REQ primitive requests the MAC address currently associated with the PPA attached to the streams. The address is returned by the DL_PHYS_ADDR_ACK primitive. When using Style 2, this primitive is only valid following a successful DL_ATTACH_REQ.DLPI primitivesDL_SET_PHYS_ADDR_REQDLPI primitivesDL_SET_PHYS_ADDR_REQThe DL_SET_PHYS_ADDR_REQ primitive changes the MAC address currently associated with the PPA attached to the streams. This primitive affects all other current and future streams attached to this device. Once changed, all streams currently or subsequently opened and attached to this device obtain this new physical address. The new physical address remains in effect until this primitive changes the physical address again or the driver is reloaded.The superuser is allowed to change the physical address of a PPA while other streams are bound to the same PPA. DLPI primitivesDL_GET_STATISTICS_REQDLPI primitivesDL_GET_STATISTICS_ACKDLPI primitivesDL_GET_STATISTICS_ACKDLPI primitivesDL_GET_STATISTICS_REQThe DL_GET_STATISTICS_REQ primitive requests a DL_GET_STATISTICS_ACK response containing statistics information associated with the PPA attached to the stream. Style 2 Streams must be attached to a particular PPA using DL_ATTACH_REQ before this primitive can succeed. GLD ioctl functions GLD implements the ioctl ioc_cmd function described below. If GLD receives an unrecognizable ioctl command, GLD passes the command to the device-specific driver's gldm_ioctl routine, as described in gld9E.snoop commandnetwork driversDLIOCRAWioctl functionioctl functionDLIOCRAWThe DLIOCRAW ioctl function is used by some DLPI applications, most notably the snoop1M command. The DLIOCRAW command puts the stream into a raw mode. In raw mode, the driver passes full MAC-level incoming packets upstream in M_DATA messages instead of transforming the packets into the DL_UNITDATA_IND form. The DL_UNITDATA_IND form is normally used for reporting incoming packets. Packet SAP filtering is still performed on streams that are in raw mode. If a stream user wants to receive all incoming packets, the user must also select the appropriate promiscuous modes. After successfully selecting raw mode, the application is also allowed to send fully formatted packets to the driver as M_DATA messages for transmission. DLIOCRAW takes no arguments. Once enabled, the stream remains in this mode until closed. GLD-based drivers must include the header file <sys/gld.h>.GLD-based drivers must be linked with the N“misc/gld” option:%ld -r -N"misc/gld" xx.o -o xxGLD implements the following functions on behalf of the device-specific driver:open9E close9E put9E, required for STREAMS srv9E, required for STREAMS getinfo9E module_info structurenetwork driversThe mi_idname element of the module_info9S structure is a string that specifies the name of the driver. This string must exactly match the name of the driver module as defined in the file system.The read-side qinit9S structure should specify the following elements:qi_putpNULL qi_srvpgld_rsrv qi_qopengld_open qi_qclosegld_close The write-side qinit9S structure should specify these elements:qi_putpgld_wput qi_srvpgld_wsrv qi_qopenNULL qi_qcloseNULL The devo_getinfo element of the dev_ops9S structure should specify gld_getinfo as the getinfo9E routine.The driver's attach9E function associates the hardware-specific device driver with the GLD facility. attach then prepares the device and driver for use.gld_mac_info structurenetwork driversinterruptsnetwork driversThe attach9E function allocates a gld_mac_info9S structure using gld_mac_alloc. The driver usually needs to save more information per device than is defined in the macinfo structure. The driver should allocate the additional required data structure and save a pointer to the structure in the gldm_private member of the gld_mac_info9S structure.The attach9E routine must initialize the macinfo structure as described in the gld_mac_info9S man page. The attach routine should then call gld_register to link the driver with the GLD module. The driver should map registers if necessary and be fully initialized and prepared to accept interrupts before calling gld_register. The attach9E function should add interrupts but should not enable the device to generate these interrupts. The driver should reset the hardware before calling gld_register to ensure the hardware is quiescent. A device must not be put into a state where the device might generate an interrupt before gld_register is called. The device is started later when GLD calls the driver's gldm_start entry point, which is described in the gld9E man page. After gld_register succeeds, the gld9E entry points might be called by GLD at any time.The attach9E routine should return DDI_SUCCESS if gld_register succeeds. If gld_register fails, DDI_FAILURE is returned. If a failure occurs, the attach9E routine should deallocate any resources that were allocated before gld_register was called. The attach routine should then also return DDI_FAILURE. A failed macinfo structure should never be reused. Such a structure should be deallocated using gld_mac_free.gld9F functionnetwork driverddi_get_driver_private functionThe detach9Efunction should attempt to unregister the driver from GLD by calling gld_unregister. For more information about gld_unregister, see the gld9F man page. The detach9E routine can get a pointer to the needed gld_mac_info9S structure from the device's private data using ddi_get_driver_private9F. gld_unregister checks certain conditions that could require that the driver not be detached. If the checks fail, gld_unregister returns DDI_FAILURE, in which case the driver's detach9E routine must leave the device operational and return DDI_FAILURE.If the checks succeed, gld_unregister ensures that the device interrupts are stopped. The driver's gldm_stop routine is called if necessary. The driver is unlinked from the GLD framework. gld_unregister then returns DDI_SUCCESS. In this case, the detach9E routine should remove interrupts and use gld_mac_free to deallocate any macinfo data structures that were allocated in the attach9E routine. The detach routine should then return DDI_SUCCESS. The routine must remove the interrupt before calling gld_mac_free. GLD network statistics kstatsnetwork statisticsnetwork statisticskstat structuresDLPI primitivesDL_GET_STATISTICS_REQSolaris network drivers must implement statistics variables. GLD tallies some network statistics, but other statistics must be counted by each GLD-based driver. GLD provides support for GLD-based drivers to report a standard set of network driver statistics. Statistics are reported by GLD using the kstat7D and kstat9S mechanisms. The DL_GET_STATISTICS_REQ DLPI command can also be used to retrieve the current statistics counters. All statistics are maintained as unsigned. The statistics are 32 bits unless otherwise noted.GLD maintains and reports the following statistics.rbytes64Total bytes successfully received on the interface. Stores 64-bit statistics. rbytesTotal bytes successfully received on the interface obytes64Total bytes that have requested transmission on the interface. Stores 64-bit statistics. obytesTotal bytes that have requested transmission on the interface. ipackets64Total packets successfully received on the interface. Stores 64-bit statistics. ipacketsTotal packets successfully received on the interface. opackets64Total packets that have requested transmission on the interface. Stores 64-bit statistics. opacketsTotal packets that have requested transmission on the interface. multircvMulticast packets successfully received, including group and functional addresses (long). multixmtMulticast packets requested to be transmitted, including group and functional addresses (long). brdcstrcvBroadcast packets successfully received (long). brdcstxmtBroadcast packets that have requested transmission (long). unknownsValid received packets not accepted by any stream (long). noxmtbufPackets discarded on output because transmit buffer was busy, or no buffer could be allocated for transmit (long). blockedNumber of times a received packet could not be put up a stream because the queue was flow-controlled (long). xmtretryTimes transmit was retried after having been delayed due to lack of resources (long). promiscCurrent “promiscuous” state of the interface (string). network statisticsgldm_get_statsgldm_get_statsdescription ofgld_stats structurenetwork drivernetwork statisticsgld_statsThe device-dependent driver tracks the following statistics in a private per-instance structure. To report statistics, GLD calls the driver's gldm_get_stats entry point. gldm_get_stats then updates device-specific statistics in the gld_stats9S structure. See the gldm_get_stats9E man page for more information. GLD then reports the updated statistics using the named statistics variables that are shown below.ifspeedCurrent estimated bandwidth of the interface in bits per second. Stores 64-bit statistics. mediaCurrent media type in use by the device (string). intrNumber of times that the interrupt handler was called, causing an interrupt (long). norcvbufNumber of times a valid incoming packet was known to have been discarded because no buffer could be allocated for receive (long). ierrorsTotal number of packets that were received but could not be processed due to errors (long). oerrorsTotal packets that were not successfully transmitted because of errors (long). missedPackets known to have been dropped by the hardware on receive (long). ufloTimes FIFO underflowed on transmit (long). ofloTimes receiver overflowed during receive (long). network statisticsDL_ETHERDL_ETHERnetwork statisticsEthernet V2DL_ETHERfibre distributed data interfaceDL_FDDIThe following group of statistics applies to networks of type DL_ETHER. These statistics are maintained by device-specific drivers of that type, as shown previously.align_errorsPackets that were received with framing errors, that is, the packets did not contain an integral number of octets (long). fcs_errorsPackets received with CRC errors (long). duplexCurrent duplex mode of the interface (string). carrier_errorsNumber of times carrier was lost or never detected on a transmission attempt (long). collisionsEthernet collisions during transmit (long). ex_collisionsFrames where excess collisions occurred on transmit, causing transmit failure (long). tx_late_collisionsNumber of times a transmit collision occurred late, that is, after 512 bit times (long). defer_xmtsPackets without collisions where first transmit attempt was delayed because the medium was busy (long). first_collisionsPackets successfully transmitted with exactly one collision. multi_collisionsPackets successfully transmitted with multiple collisions. sqe_errorsNumber of times that SQE test error was reported. macxmt_errorsPackets encountering transmit MAC failures, except carrier and collision failures. macrcv_errorsPackets received with MAC errors, except align_errors, fcs_errors, and toolong_errors. toolong_errorsPackets received larger than the maximum allowed length. runt_errorsPackets received smaller than the minimum allowed length (long). The following group of statistics applies to networks of type DL_TPR. These statistics are maintained by device-specific drivers of that type, as shown above.line_errorsPackets received with non-data bits or FCS errors. burst_errorsNumber of times an absence of transitions for five half-bit timers was detected. signal_lossesNumber of times loss of signal condition on the ring was detected. ace_errorsNumber of times that an AMP or SMP frame, in which A is equal to C is equal to 0, is followed by another SMP frame without an intervening AMP frame. internal_errorsNumber of times the station recognized an internal error. lost_frame_errorsNumber of times the TRR timer expired during transmit. frame_copied_errorsNumber of times a frame addressed to this station was received with the FS field `A' bit set to 1. token_errorsNumber of times the station acting as the active monitor recognized an error condition that needed a token transmitted. freq_errorsNumber of times the frequency of the incoming signal differed from the expected frequency. The following group of statistics applies to networks of type DL_FDDI. These statistics are maintained by device-specific drivers of that type, as shown above.mac_errorsFrames detected in error by this MAC that had not been detected in error by another MAC. mac_lost_errorsFrames received with format errors such that the frame was stripped. mac_tokensNumber of tokens that were received, that is, the total of non-restricted and restricted tokens. mac_tvx_expiredNumber of times that TVX has expired. mac_lateNumber of TRT expirations since either this MAC was reset or a token was received. mac_ring_opsNumber of times the ring has entered the “Ring Operational” state from the “Ring Not Operational” state. data structuresGLDThis section describes the gld_mac_info9S and gld_stats structures.GLD data structuresgld_mac_info gld_mac_info structuredescription of The GLD MAC information (gld_mac_info) structure is the main data interface that links the device-specific driver with GLD. This structure contains data required by GLD and a pointer to an optional additional driver-specific information structure.Allocate the gld_mac_info structure using gld_mac_alloc. Deallocate the structure using gld_mac_free. Drivers must not make any assumptions about the length of this structure, which might vary in different releases of the Solaris OS, GLD, or both. Structure members private to GLD, not documented here, should neither be set nor be read by the device-specific driver.The gld_mac_info9S structure contains the following fields.caddr_t gldm_private; /* Driver private data */ int (*gldm_reset)(); /* Reset device */ int (*gldm_start)(); /* Start device */ int (*gldm_stop)(); /* Stop device */ int (*gldm_set_mac_addr)(); /* Set device phys addr */ int (*gldm_set_multicast)(); /* Set/delete multicast addr */ int (*gldm_set_promiscuous)(); /* Set/reset promiscuous mode */ int (*gldm_send)(); /* Transmit routine */ uint_t (*gldm_intr)(); /* Interrupt handler */ int (*gldm_get_stats)(); /* Get device statistics */ int (*gldm_ioctl)(); /* Driver-specific ioctls */ char *gldm_ident; /* Driver identity string */ uint32_t gldm_type; /* Device type */ uint32_t gldm_minpkt; /* Minimum packet size */ /* accepted by driver */ uint32_t gldm_maxpkt; /* Maximum packet size */ /* accepted by driver */ uint32_t gldm_addrlen; /* Physical address length */ int32_t gldm_saplen; /* SAP length for DL_INFO_ACK */ unsigned char *gldm_broadcast_addr; /* Physical broadcast addr */ unsigned char *gldm_vendor_addr; /* Factory MAC address */ t_uscalar_t gldm_ppa; /* Physical Point of */ /* Attachment (PPA) number */ dev_info_t *gldm_devinfo; /* Pointer to device's */ /* dev_info node */ ddi_iblock_cookie_t gldm_cookie; /* Device's interrupt */ /* block cookie */The gldm_private structure member is visible to the device driver. gldm_private is also private to the device-specific driver. gldm_private is not used or modified by GLD. Conventionally, gldm_private is used as a pointer to private data, pointing to a per-instance data structure that is both defined and allocated by the driver.gldm_private structureThe following group of structure members must be set by the driver before calling gld_register, and should not thereafter be modified by the driver. Because gld_register might use or cache the values of structure members, changes made by the driver after calling gld_register might cause unpredictable results. For more information on these structures, see the gld9E man page.gldm_resetPointer to driver entry point. gldm_startPointer to driver entry point. gldm_stopPointer to driver entry point. gldm_set_mac_addrPointer to driver entry point. gldm_set_multicastPointer to driver entry point. gldm_set_promiscuousPointer to driver entry point. gldm_sendPointer to driver entry point. gldm_intrPointer to driver entry point. gldm_get_statsPointer to driver entry point. gldm_ioctlPointer to driver entry point. This pointer is allowed to be null. gldm_identPointer to a string that contains a short description of the device. This pointer is used to identify the device in system messages. gldm_typeType of device the driver handles. GLD currently supports the following values:DL_ETHER (ISO 8802-3 (IEEE 802.3) and Ethernet Bus) DL_TPR (IEEE 802.5 Token Passing Ring) DL_FDDI (ISO 9314-2 Fibre Distributed Data Interface) This structure member must be correctly set for GLD to function properly. gldm_minpktMinimum Service Data Unit size: the minimum packet size, not including the MAC header, that the device can transmit. This size is allowed to be zero if the device-specific driver handles any required padding. gldm_maxpktMaximum Service Data Unit size: the maximum size of packet, not including the MAC header, that can be transmitted by the device. For Ethernet, this number is 1500. gldm_addrlenThe length in bytes of physical addresses handled by the device. For Ethernet, Token Ring, and FDDI, the value of this structure member should be 6. gldm_saplenThe length in bytes of the SAP address used by the driver. For GLD-based drivers, the length should always be set to -2. A length of -2 indicates that 2-byte SAP values are supported and that the SAP appears after the physical address in a DLSAP address. See Appendix A.2, “Message DL_INFO_ACK,” in the DLPI specification for more details. gldm_broadcast_addrPointer to an array of bytes of length gldm_addrlen containing the broadcast address to be used for transmit. The driver must provide space to hold the broadcast address, fill the space with the appropriate value, and set gldm_broadcast_addr to point to the address. For Ethernet, Token Ring, and FDDI, the broadcast address is normally 0xFF-FF-FF-FF-FF-FF. gldm_vendor_addrPointer to an array of bytes of length gldm_addrlen that contains the vendor-provided network physical address of the device. The driver must provide space to hold the address, fill the space with information from the device, and set gldm_vendor_addr to point to the address. gldm_ppaddi_get_instance functionPPA number for this instance of the device. The PPA number should always be set to the instance number that is returned from ddi_get_instance9F. gldm_devinfoPointer to the dev_info node for this device. gldm_cookieInterrupt block cookie returned by one of the following routines:ddi_get_iblock_cookie9F ddi_add_intr9F ddi_get_soft_iblock_cookie9F ddi_add_softintr9F This cookie must correspond to the device's receive-interrupt, from which gld_recv is called. data structuresGLD GLD data structuresgld_stats After calling gldm_get_stats, a GLD-based driver uses the (gld_stats) structure to communicate statistics and state information to GLD. See the gld9E and gld7D man pages. The members of this structure, having been filled in by the GLD-based driver, are used when GLD reports the statistics. In the tables below, the name of the statistics variable reported by GLD is noted in the comments. See the gld7D man page for a more detailed description of the meaning of each statistic.Drivers must not make any assumptions about the length of this structure. The structure length might vary in different releases of the Solaris OS, GLD, or both. Structure members private to GLD, which are not documented here, should not be set or be read by the device-specific driver.The following structure members are defined for all media types:uint64_t glds_speed; /* ifspeed */ uint32_t glds_media; /* media */ uint32_t glds_intr; /* intr */ uint32_t glds_norcvbuf; /* norcvbuf */ uint32_t glds_errrcv; /* ierrors */ uint32_t glds_errxmt; /* oerrors */ uint32_t glds_missed; /* missed */ uint32_t glds_underflow; /* uflo */ uint32_t glds_overflow; /* oflo */The following structure members are defined for media type DL_ETHER:uint32_t glds_frame; /* align_errors */ uint32_t glds_crc; /* fcs_errors */ uint32_t glds_duplex; /* duplex */ uint32_t glds_nocarrier; /* carrier_errors */ uint32_t glds_collisions; /* collisions */ uint32_t glds_excoll; /* ex_collisions */ uint32_t glds_xmtlatecoll; /* tx_late_collisions */ uint32_t glds_defer; /* defer_xmts */ uint32_t glds_dot3_first_coll; /* first_collisions */ uint32_t glds_dot3_multi_coll; /* multi_collisions */ uint32_t glds_dot3_sqe_error; /* sqe_errors */ uint32_t glds_dot3_mac_xmt_error; /* macxmt_errors */ uint32_t glds_dot3_mac_rcv_error; /* macrcv_errors */ uint32_t glds_dot3_frame_too_long; /* toolong_errors */ uint32_t glds_short; /* runt_errors */The following structure members are defined for media type DL_TPR:uint32_t glds_dot5_line_error /* line_errors */ uint32_t glds_dot5_burst_error /* burst_errors */ uint32_t glds_dot5_signal_loss /* signal_losses */ uint32_t glds_dot5_ace_error /* ace_errors */ uint32_t glds_dot5_internal_error /* internal_errors */ uint32_t glds_dot5_lost_frame_error /* lost_frame_errors */ uint32_t glds_dot5_frame_copied_error /* frame_copied_errors */ uint32_t glds_dot5_token_error /* token_errors */ uint32_t glds_dot5_freq_error /* freq_errors */The following structure members are defined for media type DL_FDDI:uint32_t glds_fddi_mac_error; /* mac_errors */ uint32_t glds_fddi_mac_lost; /* mac_lost_errors */ uint32_t glds_fddi_mac_token; /* mac_tokens */ uint32_t glds_fddi_mac_tvx_expired; /* mac_tvx_expired */ uint32_t glds_fddi_mac_late; /* mac_late */ uint32_t glds_fddi_mac_ring_op; /* mac_ring_ops */Most of the above statistics variables are counters that denote the number of times that the particular event was observed. The following statistics do not represent the number of times:glds_speedEstimate of the interface's current bandwidth in bits per second. This object should contain the nominal bandwidth for those interfaces that do not vary in bandwidth or where an accurate estimate cannot be made. glds_mediaType of media (wiring) or connector used by the hardware. The following media names are supported:GLDM_AUI GLDM_BNC GLDM_TP GLDM_10BT GLDM_100BT GLDM_100BTX GLDM_100BT4 GLDM_RING4 GLDM_RING16 GLDM_FIBER GLDM_PHYMII GLDM_UNKNOWN glds_duplexCurrent duplex state of the interface. Supported values are GLD_DUPLEX_HALF and GLD_DUPLEX_FULL. GLD_DUPLEX_UNKNOWN is also allowed. The following arguments are used by the GLD routines.macinfogld_mac_info structureGLD argumentsPointer to a gld_mac_info9S structure. macaddrPointer to the beginning of a character array that contains a valid MAC address. The array is of the length specified by the driver in the gldm_addrlen element of the gld_mac_info9S structure. multicastaddrPointer to the beginning of a character array that contains a multicast, group, or functional address. The array is of the length specified by the driver in the gldm_addrlen element of the gld_mac_info9S structure. multiflagFlag indicating whether to enable or disable reception of the multicast address. This argument is specified as GLD_MULTI_ENABLE or GLD_MULTI_DISABLE. promiscflagGLD symbolsGLD_MAC_PROMISC_PHYSGLD symbolsGLD_MAC_PROMISC_MULTIGLD symbolsGLD_MAC_PROMISC_NONEFlag indicating what type of promiscuous mode, if any, is to be enabled. This argument is specified as GLD_MAC_PROMISC_PHYS, GLD_MAC_PROMISC_MULTI, or GLD_MAC_PROMISC_NONE. mpgld_ioctl uses mp as a pointer to a STREAMS message block containing the ioctl to be executed. gldm_send uses mp as a pointer to a STREAMS message block containing the packet to be transmitted. gld_recv uses mp as a pointer to a message block containing a received packet. statsPointer to a gld_stats9S structure to be filled in with the current values of statistics counters. qPointer to the queue9S structure to be used in the reply to the ioctl. dipPointer to the device's dev_info structure. nameDevice interface name. entry pointsfor network drivers Entry points must be implemented by a device-specific network driver that has been designed to interface with GLD.The gld_mac_info9S structure is the main structure for communication between the device-specific driver and the GLD module. See the gld7D man page. Some elements in that structure are function pointers to the entry points that are described here. The device-specific driver must, in its attach9E routine, initialize these function pointers before calling gld_register.int prefix_reset(gld_mac_info_t *macinfo);GLD entry pointsgldm_resetgldm_reset resets the hardware to its initial state. int prefix_start(gld_mac_info_t *macinfo);GLD entry pointsgldm_startgldm_start enables the device to generate interrupts. gldm_start also prepares the driver to call gld_recv to deliver received data packets to GLD. GLD entry pointsgldm_stop int prefix_stop(gld_mac_info_t *macinfo);gldm_stop disables the device from generating any interrupts and stops the driver from calling gld_recv for delivering data packets to GLD. GLD depends on the gldm_stop routine to ensure that the device will no longer interrupt. gldm_stop must do so without fail. This function should always return GLD_SUCCESS. GLD entry pointsgldm_set_mac_addr int prefix_set_mac_addr(gld_mac_info_t *macinfo, unsigned char *macaddr);GLD symbolsGLD_NOTSUPPORTEDgldm_set_mac_addr sets the physical address that the hardware is to use for receiving data. This function enables the device to be programmed through the passed MAC address macaddr. If sufficient resources are currently not available to carry out the request, gldm_set_mac_add should return GLD_NORESOURCES. If the requested function is not supported, gldm_set_mac_add should return GLD_NOTSUPPORTED. GLD entry pointsgldm_set_multicast int prefix_set_multicast(gld_mac_info_t *macinfo, unsigned char *multicastaddr, int multiflag);GLD symbolsGLD_MULTI_ENABLEGLD symbolsGLD_MULTI_DISABLEgldm_set_multicast enables and disables device-level reception of specific multicast addresses. If the third argument multiflag is set to GLD_MULTI_ENABLE, then gldm_set_multicast sets the interface to receive packets with the multicast address. gldm_set_multicast uses the multicast address that is pointed to by the second argument. If multiflag is set to GLD_MULTI_DISABLE, the driver is allowed to disable reception of the specified multicast address.This function is called whenever GLD wants to enable or disable reception of a multicast, group, or functional address. GLD makes no assumptions about how the device does multicast support and calls this function to enable or disable a specific multicast address. Some devices might use a hash algorithm and a bitmask to enable collections of multicast addresses. This procedure is allowed, and GLD filters out any superfluous packets. If disabling an address could result in disabling more than one address at the device level, the device driver should keep any necessary information. This approach avoids disabling an address that GLD has enabled but not disabled.gldm_set_multicast is not called to enable a particular multicast address that is already enabled. Similarly, gldm_set_multicast is not called to disable an address that is not currently enabled. GLD keeps track of multiple requests for the same multicast address. GLD only calls the driver's entry point when the first request to enable, or the last request to disable, a particular multicast address is made. If sufficient resources are currently not available to carry out the request, the function should return GLD_NORESOURCES. The function should return GLD_NOTSUPPORTED if the requested function is not supported. GLD entry pointsgldm_set_promiscuous int prefix_set_promiscuous(gld_mac_info_t *macinfo, int promiscflag);gldm_set_promiscuous enables and disables promiscuous mode. This function is called whenever GLD wants to enable or disable the reception of all packets on the medium. The function can also be limited to multicast packets on the medium. If the second argument promiscflag is set to the value of GLD_MAC_PROMISC_PHYS, then the function enables physical-level promiscuous mode. Physical-level promiscuous mode causes the reception of all packets on the medium. If promiscflag is set to GLD_MAC_PROMISC_MULTI, then reception of all multicast packets are enabled. If promiscflag is set to GLD_MAC_PROMISC_NONE, then promiscuous mode is disabled.In promiscuous multicast mode, drivers for devices without multicast-only promiscuous mode must set the device to physical promiscuous mode. This approach ensures that all multicast packets are received. In this case, the routine should return GLD_SUCCESS. The GLD software filters out any superfluous packets. If sufficient resources are currently not available to carry out the request, the function should return GLD_NORESOURCES. gld_set_promiscuous should return GLD_NOTSUPPORTED if the requested function is not supported.For forward compatibility, gldm_set_promiscuous routines should treat any unrecognized values for promiscflag as though these values were GLD_MAC_PROMISC_PHYS. GLD entry pointsgldm_send int prefix_send(gld_mac_info_t *macinfo, mblk_t *mp);gldm_send queues a packet to the device for transmission. This routine is passed a STREAMS message containing the packet to be sent. The message might include multiple message blocks. The send routine must traverse all the message blocks in the message to access the entire packet to be sent. The driver should be prepared to handle and skip over any zero-length message continuation blocks in the chain. The driver should also check that the packet does not exceed the maximum allowable packet size. The driver must pad the packet, if necessary, to the minimum allowable packet size. If the send routine successfully transmits or queues the packet, GLD_SUCCESS should be returned.The send routine should return GLD_NORESOURCES if the packet for transmission cannot be immediately accepted. In this case, GLD retries later. If gldm_send ever returns GLD_NORESOURCES, the driver must call gld_sched at a later time when resources have become available. This call to gld_sched informs GLD to retry packets that the driver previously failed to queue for transmission. (If the driver's gldm_stop routine is called, the driver is absolved from this obligation until the driver returns GLD_NORESOURCES from the gldm_send routine. However, extra calls to gld_sched do not cause incorrect operation.)GLD symbolsGLD_NOLINKIf the driver's send routine returns GLD_SUCCESS, then the driver is responsible for freeing the message when the message is no longer needed. If the hardware uses DMA to read the data directly, the driver must not free the message until the hardware has completely read the data. In this case, the driver can free the message in the interrupt routine. Alternatively, the driver can reclaim the buffer at the start of a future send operation. If the send routine returns anything other than GLD_SUCCESS, then the driver must not free the message. Return GLD_NOLINK if gldm_send is called when there is no physical connection to the network or link partner. GLD entry pointsgldm_intr int prefix_intr(gld_mac_info_t *macinfo);gldm_intr is called when the device might have interrupted. Because interrupts can be shared with other devices, the driver must check the device status to determine whether that device actually caused the interrupt. If the device that the driver controls did not cause the interrupt, then this routine must return DDI_INTR_UNCLAIMED. Otherwise, the driver must service the interrupt and return DDI_INTR_CLAIMED. If the interrupt was caused by successful receipt of a packet, this routine should put the received packet into a STREAMS message of type M_DATA and pass that message to gld_recv.gld_recv passes the inbound packet upstream to the appropriate next layer of the network protocol stack. The routine must correctly set the b_rptr and b_wptr members of the STREAMS message before calling gld_recv.The driver should avoid holding mutex or other locks during the call to gld_recv. In particular, locks that could be taken by a transmit thread must not be held during a call to gld_recv. In some cases, the interrupt thread that calls gld_recv sends an outgoing packet, which results in a call to the driver's gldm_send routine. If gldm_send tries to acquire a mutex that is held by gldm_intr when gld_recv is called, a panic occurs due to recursive mutex entry. If other driver entry points attempt to acquire a mutex that the driver holds across a call to gld_recv, deadlock can result.The interrupt code should increment statistics counters for any errors. Errors include the failure to allocate a buffer that is needed for the received data and any hardware-specific errors, such as CRC errors or framing errors. GLD entry pointsgldm_get_stats int prefix_get_stats(gld_mac_info_t *macinfo, struct gld_stats *stats);gldm_get_stats gathers statistics from the hardware, driver private counters, or both, and updates the gld_stats9S structure pointed to by stats. This routine is called by GLD for statistics requests. GLD uses the gldm_get_stats mechanism to acquire device-dependent statistics from the driver before GLD composes the reply to the statistics request. See the gld_stats9S, gld7D, and qreply9F man pages for more information about defined statistics counters. GLD entry pointsgldm_ioctl int prefix_ioctl(gld_mac_info_t *macinfo, queue_t *q, mblk_t *mp);gldm_ioctl implements any device-specific ioctl commands. This element is allowed to be null if the driver does not implement any ioctl functions. The driver is responsible for converting the message block into an ioctl reply message and calling the qreply9F function before returning GLD_SUCCESS. This function should always return GLD_SUCCESS. The driver should report any errors as needed in a message to be passed to qreply9F. If the gldm_ioctl element is specified as NULL, GLD returns a message of type M_IOCNAK with an error of EINVAL. Some entry point functions in GLD can return the following values, subject to the restrictions above:GLD_BADARGGLD symbolsGLD_BADARGIf the function detected an unsuitable argument, for example, a bad multicast address, a bad MAC address, or a bad packet GLD_FAILUREGLD symbolsGLD_FAILUREOn hardware failure GLD_SUCCESSGLD symbolsGLD_SUCCESSOn success This section provides the syntax and description for the GLD service routines.GLD service routinesgld_mac_alloc function gld_mac_alloc function gld_mac_info_t *gld_mac_alloc(dev_info_t *dip);gld_mac_alloc allocates a new gld_mac_info9S structure and returns a pointer to the structure. Some of the GLD-private elements of the structure might be initialized before gld_mac_alloc returns. All other elements are initialized to zero. The device driver must initialize some structure members, as described in the gld_mac_info9S man page, before passing the pointer to the gld_mac_info structure to gld_register. GLD service routinesgld_mac_free function gld_mac_free function void gld_mac_free(gld_mac_info_t *macinfo);gld_mac_free frees a gld_mac_info9S structure previously allocated by gld_mac_alloc. GLD service routinesgld_register function gld_register function int gld_register(dev_info_t *dip, char *name, gld_mac_info_t *macinfo);gld_register is called from the device driver's attach9E routine. gld_register links the GLD-based device driver with the GLD framework. Before calling gld_register, the device driver's attach9E routine uses gld_mac_alloc to allocate a gld_mac_info9S structure, and then initializes several structure elements. See gld_mac_info9S for more information. A successful call to gld_register performs the following actions:Links the device-specific driver with the GLD system Sets the device-specific driver's private data pointer, using ddi_set_driver_private9F to point to the macinfo structure Creates the minor device node Returns DDI_SUCCESS The device interface name passed to gld_register must exactly match the name of the driver module as that name exists in the file system.The driver's attach9E routine should return DDI_SUCCESS if gld_register succeeds. If gld_register does not return DDI_SUCCESS, the attach9E routine should deallocate any allocated resources before calling gld_register, and then return DDI_FAILURE. GLD service routinesgld_unregister function gld_unregister function int gld_unregister(gld_mac_info_t *macinfo);gld_unregister is called by the device driver's detach9E function, and if successful, performs the following tasks:Ensures that the device's interrupts are stopped, calling the driver's gldm_stop routine if necessary Removes the minor device node Unlinks the device-specific driver from the GLD system Returns DDI_SUCCESS If gld_unregister returns DDI_SUCCESS, the detach9E routine should deallocate any data structures allocated in the attach9E routine, using gld_mac_free to deallocate the macinfo structure, and return DDI_SUCCESS. If gld_unregister does not return DDI_SUCCESS, the driver's detach9E routine must leave the device operational and return DDI_FAILURE. GLD service routinesgld_recv function gld_recv function void gld_recv(gld_mac_info_t *macinfo, mblk_t *mp);gld_recv is called by the driver's interrupt handler to pass a received packet upstream. The driver must construct and pass a STREAMS M_DATA message containing the raw packet. gld_recv determines which STREAMS queues should receive a copy of the packet, duplicating the packet if necessary. gld_recv then formats a DL_UNITDATA_IND message, if required, and passes the data up all appropriate streams.The driver should avoid holding mutex or other locks during the call to gld_recv. In particular, locks that could be taken by a transmit thread must not be held during a call to gld_recv. The interrupt thread that calls gld_recv in some cases carries out processing that includes sending an outgoing packet. Transmission of the packet results in a call to the driver's gldm_send routine. If gldm_send tries to acquire a mutex that is held by gldm_intr when gld_recv is called, a panic occurs due to a recursive mutex entry. If other driver entry points attempt to acquire a mutex that the driver holds across a call to gld_recv, deadlock can result. GLD service routinesgld_sched function gld_sched function void gld_sched(gld_mac_info_t *macinfo);GLD symbolsGLD_NORESOURCESgld_sched is called by the device driver to reschedule stalled outbound packets. Whenever the driver's gldm_send routine returns GLD_NORESOURCES, the driver must call gld_sched to inform the GLD framework to retry previously unsendable packets. gld_sched should be called as soon as possible after resources become available so that GLD resumes passing outbound packets to the driver's gldm_send routine. (If the driver's gldm_stop routine is called, the driver need not retry until GLD_NORESOURCES is returned from gldm_send. However, extra calls to gld_sched do not cause incorrect operation.) GLD service routinesgld_intr function gld_intr function interrupt handlinggld_intr function uint_t gld_intr(caddr_t);gld_mac_info structureused in gld_intr functiongld_intr is GLD's main interrupt handler. Normally, gld_intr is specified as the interrupt routine in the device driver's call to ddi_add_intr9F. The argument to the interrupt handler is specified as int_handler_arg in the call to ddi_add_intr9F. This argument must be a pointer to the gld_mac_info9S structure. gld_intr, when appropriate, calls the device driver's gldm_intr function, passing that pointer to the gld_mac_info9S structure. However, to use a high-level interrupt, the driver must provide its own high-level interrupt handler and trigger a soft interrupt from within the handler. In this case, gld_intr would normally be specified as the soft interrupt handler in the call to ddi_add_softintr. gld_intr returns a value that is appropriate for an interrupt handler.