NIO CommKit Host Interface Installation and System Administration Manual
DKHS(7) DKHS(7)
E-84 CommKit Host Interface, Release 4.0
M_DATA Outbound data for transmission should be sent to the driver encapsulated in M_DATA
messages.
The message chain is transmitted on the circuit using URP GOS5 as zero or more
intermediate BOTM blocks followed by a single BOT block.
M_DELAY The appropriate combination of URP Level–D DELAY control codes is transmitted on
the circuit associated with the Stream when this message is received. The one or more
control codes are transmitted within a single URP block.
M_FLUSH Standard STREAMS support for M_FLUSH messages is provided.
M_IOCTL A number of commands may be sent from user-level to the driver in the form of
M_IOCTL messages.
M_PROTO The transmission of URP Level–D control codes may be requested via appropriately
formatted M_PROTO messages.
M_START Starts the previously halted transmitter associated with the Stream so user data
transmission on the circuit may resume.
M_STARTI Releases the previously flow controlled receiver associated with the Stream so
incoming data may be sent upstream.
M_STOP Halts the transmitter associated with the Stream so no new user data blocks are
transmitted on the circuit until a subsequent M_START is received.
M_STOPI Flow controls the receiver associated with the Stream so no M_DATA messages are sent
upstream until a subsequent M_STARTI is received.
FILES
/dev/dk/ctlX Common Signaling Channel device for interface X
/dev/dk/diagX diagnostic device for interface X
/dev/dk/dial default dialing device
/dev/dk/dialX clone device for interface X
/dev/dk/intf.chan individual raw channel devices
SEE ALSO
dkdaemon(1M), dkdiag(1M), dkitrc(1M), dkmaint(1M), dkserver(1M), dkleveld(3X), dktli(7), dkty(7),
dkux(7)
getmsg(2), putmsg(2), read(2) in the UNIX System V Programmer’s Reference Manual.
DIAGNOSTICS
Several error values have different or uncommon meanings when received from the dkhs driver. The errors
returned by dkhs are:
EBADMSG A read(2) system call will return this error when a M_PROTO message containing an
URP Level–D control code reaches the head of the Stream. Use isdkleveld() (see
dkleveld(3X)) or getmsg(2) to retrieve the message containing the Level–D code.
EBUSY All attempts to open a device that is marked EXCLUSIVE , or attempts to open the
diagnostic device while the interface is active will be failed with an EBUSY error return
code.