scman(7D) (man pages section 7: Device and Network Interfaces)

man pages section 7: Device and Network Interfaces

scman(7D)

NAME

scman– SUNW,scman Sun Fire high-end server management network device driver

SYNOPSIS

/dev/scman

DESCRIPTION

The scman (7D) network device driver is a loadable, clonable, STREAMS hardware driver that supports the dlpi connectionless data link provider interface over the SUNW,scman network controller. The scman controller provides a highly available, secure communication channel between the dynamic system domains and the Sun Fire high-end system controller.

The scman driver provides basic support for the SUNW,scman controller. Driver functions include network initialization, frame transit and receive, multicast and promiscuous support, and error recovery and reporting.

The scman controller is physically located in each Sun Fire high-end server dynamic system domain and connects to SUNWdman controllers found in each active dynamic system domain in the Sun Fire high-end chassis. See dman(7D). All links are point-to-point and are internal to the Sun Fire high-end server chassis. Traffic between the system controller and the dynamic system domains is not accessible by any third party; for example, another system domain within the Sun Fire high-end chassis. All system domains are accessible through the scman controller.

The link layer frame format is identical to that used by Ethernet (sys/ethernet.h).

APPLICATION PROGRAMMING INTERFACE

The /dev/scman cloning character-special device is used to access the SUNW,scman controller installed on the system.

DLPI

The scman driver is a style 2 data link provider interface. 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 or physical point of attachment (PPA).

The PPA ID is interpreted as an unsigned long data type and indicates the corresponding device instance (unit) number. The only valid unit number is 0. 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 the first attach and deinitialized (stopped) upon the last detach.

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

Maximum service data units (SDU) are 1500.
Minimum SDU is 0.
Data link service access point (DLSAP) address length is 8.
Media access control (MAC) type is DL_ETHER.
Service access point (SAP) length value is -2, meaning the physical address component is followed immediately by a two-byte SAP component within the DLSAP address.
Service mode is DL_CLDLS.
Optional quality of service (QOS) support is not included; the QOS fields are 0.
Provider style is DL_STYLE2.
Version is DL_VERSION_2.
Broadcast address value is Ethernet/IEEE broadcast address (0xFFFFFF).

Once in the DL_ATTACHED state, you can transmit DL_BIND_REQ to associate a particular SAP with the stream. The scman driver interprets the SAP field within the DL_BIND_REQ as an Ethernet type; as a result, valid values for the SAP field are in the 0 through 0xFFFF range. Only one Ethernet type can be bound to the stream at any time.

If you select the 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 from 0 through 1500 are assumed to be 802.3 frames and are routed up all open streams that are bound to SAP value 0. If more than one stream is in 802.3 mode, then the frame is duplicated and routed up multiple streams as DL_UNITDATA_IND messages.

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

The scman driver DLSAP address format consists of the six-byte physical (Ethernet) address component followed immediately by the two-byte SAP (type) component producing an eight-byte DLSAP address. Applications should not be hard-coded to this implementation-specific DLSAP address format, but instead 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, you can transmit frames on the Ethernet by sending DL_UNITDATA_REQ messages to the scman driver. The scman driver routes received Ethernet frames as DL_UNITDATA_IND messages up all open and bound streams having a SAP matching the Ethernet type. 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.

PRIMITIVES

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

The DL_ENABMULTI_REQ and DL_DISABMULTI_REQ primitives enable or 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 or 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 or disables reception of all SAP (Ethernet type) values. When used with the DL_PROMISC_MULTI flag set, this enables or disables reception of all multicast group addresses. The effect of each is always on a per-stream basis and independent of other SAP and physical level configurations on this stream or other streams.

The DL_PHYS_ADDR_REQ primitive returns the six-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 is not supported.

scman DRIVER

The scman driver operates at 10 Mbps, full-duplex.

PARAMETER LIST

The scman driver allows you to set and get various parameters for the SUNW,scman device. The parameter list includes current transceiver status, current link status, interpacket gap, local transceiver capabilities, and link partner capabilities.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Architecture	Sun Fire high-end systems
Availability	SUNWscdvr

FILES

The scman driver utilizes the following files:

/dev/scman: Special character device
/platform/sun4u/kernel/drv/scman.conf: System-wide default device driver properties