man Pages(7):Device and Network Interfaces

lebuffer(7D)

NAME

le, lebuffer, ledma- Am7990 (LANCE) Ethernet device driver

SYNOPSIS

/dev/le

DESCRIPTION

The Am7990 (LANCE) Ethernet driver is a multi-threaded, loadable, clonable, STREAMS hardware driver supporting the connectionless Data Link Provider Interface, dlpi(7P) , over a LANCE Ethernet controller. The motherboard and add-in SBus LANCE controllers of several varieties are supported. Multiple LANCE controllers installed within the system are supported by the driver. The le driver provides basic support for the LANCE hardware. Functions include chip initialization, frame transmit and receive, multicast and promiscuous support, and error recovery and reporting.

APPLICATION PROGRAMMING INTERFACE

The cloning character-special device /dev/le is used to access all LANCE controllers installed within the system.

The lebuffer and ledma device drivers are bus nexus drivers which cooperate with the le leaf driver in supporting the LANCE hardware functions over several distinct slave-only and DVMA LANCE -based Ethernet controllers. The lebuffer and ledma bus nexi drivers are not directly accessible to the user.

le and DLPI

The le driver is a "style 2" Data Link Service provider. All M_PROTO and M_PCPROTO type messages are interpreted as DLPI primitives. Valid DLPI primitives are defined in <sys/dlpi.h> . Refer to dlpi(7P) for more information. An explicit DL_ATTACH_REQ message by the user is required to associate the opened stream with a particular device ( ppa ). The ppa ID is interpreted as an unsigned long data type and indicates the corresponding device instance (unit) number. An error ( DL_ERROR_ACK ) is returned by the driver if the ppa field value does not correspond to a valid device instance number for this system. The device is initialized on first attach and de-initialized (stopped) on last detach.

The values returned by the driver in the DL_INFO_ACK primitive in response to the DL_INFO_REQ from the user are as follows:

The maximum SDU is 1500 ( ETHERMTU - defined in <sys/ethernet.h> ).
The minimum SDU is 0 .
The dlsap address length is 8 .
The MAC type is DL_ETHER.
The sap length value is -2 meaning the physical address component is followed immediately by a 2 byte sap component within the DLSAP address.
The service mode is DL_CLDLS.
No optional quality of service (QOS) support is included at present so the QOS fields are 0 .
The provider style is DL_STYLE2.
The version is DL_VERSION_2.
The broadcast address value is Ethernet/IEEE broadcast address ( 0xFFFFFF ).

Once in the DL_ATTACHED state, the user must send a DL_BIND_REQ to associate a particular SAP (Service Access Pointer) with the stream. The le driver interprets the sap field within the DL_BIND_REQ as an Ethernet "type" therefore valid values for the sap field are in the [ 0 - 0xFFFF ] range. Only one Ethernet type can be bound to the stream at any time.

If the user selects a sap with a value of 0 , the receiver will be in "802.3 mode". All frames received from the media having a "type" field in the range [ 0 - 1500 ] are assumed to be 802.3 frames and are routed up all open Streams which are bound to sap value 0 . If more than one Stream is in "802.3 mode" then the frame will be duplicated and routed up multiple Streams as DL_UNITDATA_IND messages.

In transmission, the driver checks the sap field of the DL_BIND_REQ if the sap value is 0 , and if the destination type field is in the range [ 0 - 1500 ]. If either is true, the driver computes the length of the message, not including initial M_PROTO mblk (message block), of all subsequent DL_UNITDATA_REQ messages and transmits 802.3 frames that have this value in the MAC frame header length field.

The le driver DLSAP address format consists of the 6 byte physical (Ethernet) address component followed immediately by the 2 byte sap (type) component producing an 8 byte DLSAP address. Applications should not hardcode to this particular implementation-specific DLSAP address format but use information returned in the DL_INFO_ACK primitive to compose and decompose DLSAP addresses. The sap length, full DLSAP length, and sap /physical ordering are included within the DL_INFO_ACK. The physical address length can be computed by subtracting the sap length from the full DLSAP address length or by issuing the DL_PHYS_ADDR_REQ to obtain the current physical address associated with the stream.

Once in the DL_BOUND state, the user may transmit frames on the Ethernet by sending DL_UNITDATA_REQ messages to the le driver. The le driver will route received Ethernet frames up all those open and bound streams having a sap which matches the Ethernet type as DL_UNITDATA_IND messages. Received Ethernet frames are duplicated and routed up multiple open streams if necessary. The DLSAP address contained within the DL_UNITDATA_REQ and DL_UNITDATA_IND messages consists of both the sap (type) and physical (Ethernet) components.

In addition to the mandatory connectionless DLPI message set the driver additionally supports the following primitives.

le Primitives

The DL_ENABMULTI_REQ and DL_DISABMULTI_REQ primitives enable/disable reception of individual multicast group addresses. A set of multicast addresses may be iteratively created and modified on a per-stream basis using these primitives. These primitives are accepted by the driver in any state following DL_ATTACHED.

The DL_PROMISCON_REQ and DL_PROMISCOFF_REQ primitives with the DL_PROMISC_PHYS flag set in the dl_level field enables/disables reception of all ("promiscuous mode") frames on the media including frames generated by the local host. When used with the DL_PROMISC_SAP flag set this enables/disables reception of all sap (Ethernet type) values. When used with the DL_PROMISC_MULTI flag set this enables/disables reception of all multicast group addresses. The effect of each is always on a per-stream basis and independent of the other sap and physical level configurations on this stream or other streams.

The DL_PHYS_ADDR_REQ primitive returns the 6 octet Ethernet address currently associated (attached) to the stream in the DL_PHYS_ADDR_ACK primitive. This primitive is valid only in states following a successful DL_ATTACH_REQ.

The DL_SET_PHYS_ADDR_REQ primitive changes the 6 octet Ethernet address currently associated (attached) to this stream. The credentials of the process which originally opened this stream must be superuser. Otherwise EPERM is returned in the DL_ERROR_ACK. This primitive is destructive in that it affects all other current and future streams attached to this device. An M_ERROR is sent up all other streams attached to this device when this primitive is successful on this stream. Once changed, all streams subsequently opened and attached to this device will obtain this new physical address. Once changed, the physical address will remain until this primitive is used to change the physical address again or the system is rebooted, whichever comes first.

FILES

/dev/le: le special character device.
/kernel/drv/options.conf: System wide default device driver properties

DIAGNOSTICS

le%d: msg too big: %d: The message length exceeded ETHERMAX .
le%d: Babble error - sent a packet longer than 1518 bytes: While transmitting a packet, the LANCE chip has noticed that the packet's length exceeds the maximum allowed for Ethernet. This error indicates a kernel bug.
le%d: No carrier - transceiver cable problem?: The LANCE chip has lost input to its carrier detect pin while trying to transmit a packet.
le%d: Memory Error!: The LANCE chip timed out while trying to acquire the bus for a DVMA transfer.

NOTES

If you are using twisted pair Ethernet (TPE), you need to be aware of the link test feature. The IEEE 10Base-T specification states that the link test should always be enabled at the host and the hub. Complications may arise because:

Some older hubs do not provide link pulses
Some hubs are configured to not send link pulses

Under either of these two conditions the host translates the lack of link pulses into a link failure unless it is programmed to ignore link pulses. To program your system to ignore link pulses (also known as disabling the link test) do the following at the OpenBoot PROM prompt:

 <#0> ok setenv tpe-link-test? false
        tpe-link-test? = false

The above command will work for SPARCstation-10, SPARCstation-20 and SPARCclassic systems that come with built in twisted pair Ethernet ports. For other systems and for add-on boards with twisted pair Ethernet refer to the documentation that came with the system or board for information on disabling the link test.

SPARCstation-10, SPARCstation-20 and SPARCclassic systems come with a choice of built in AUI (using an adapter cable) and TPE ports. In Solaris 2.2 an auto-selection scheme was implemented in the le driver that will switch between AUI and TPE depending on which interface is active. Auto-selection uses the presence or absence of the link test on the TPE interface as one indication of whether that interface is active. In the special case where you wish to use TPE with the link-test disabled you should manually override auto-selection so that the system will use only the twisted pair port.

This override can be performed by defining the cable-selection property in the options.conf file to force the system to use TPE or AUI as appropriate. The example below sets the cable selection to TPE.

example# cd /kernel/drv
example# echo 'cable-selection="tpe";' >> options.conf

Note that the standard options.conf file contains important information; the only change to the file should be the addition of the cable-selection property. Be careful to type this line exactly as shown above, ensuring that you append to the existing file, and include the terminating semi-colon. Alternatively you can use a text editor to append the line

cable-selection="tpe";

to the end of the file.

Please refer to the SPARCstation 10 Twisted-Pair Ethernet Link Test (801-2481-10), Twisted-Pair Ethernet Link Test (801-6184-10) and the driver.conf(4) man page for details of the syntax of driver configuration files.

SunOS 5.7 Last Revised 23 Aug 1994