NIO CommKit Host Interface Installation and System Administration Manual

DKTY(7) DKTY(7)
E-88 CommKit Host Interface, Release 4.0
NAME
dkty – host tty interface module
DESCRIPTION
dkty is a STREAMS module that provides an interface between the ldterm(7) standard terminal STREAMS
module and the CommKit Host Interface STREAMS driver dkhs(7). Its primary function is to intercept and
translate write-side terminal ioctls(2) and read-side URP level-D code messages.
The functions in the c_cflag field of the termio(7)/termios(2) structure that are performed by the dkty
module are PARENB, PARODD and B0. The other functions are ignored by the dkty module. (Note that
the default flags set by the dkserver(1M) are B9600, CS7, CREAD and HUPCL. Therefore, the default is that
the parity generation is disabled.) If parity generation is enabled and CS8 is not set, the PARODD flag
specifies odd parity if set; otherwise, even parity is used. If the baud rate field CBAUD is set to zero (B0),
the dkty module will disconnect the line by sending an M_HANGUP message to the Stream-head.
The dkty module does not perform the functions specified by the INGPAR, PARMRK, and INPCK flags in
the c_iflag word of the termio(7)/termios(2) structure. In general, input parity is ignored and all eight bits are
passed up to the STREAM module above (such as, ldterm).
Read-side Behavior
The dkty module scans all upstream M_PROTO messages for URP Level–D codes and translates them
appropriately. All other messages and M_PROTO messages that do not contain Level–D codes are passed
upstream unchanged.
M_PROTO Messages containing an URP Level–D BREAK code are converted into an upstream
M_BREAK message. Messages containing a URP Level–D EOF code are converted into a
zero length upstream M_DATA message. M_PROTO messages containing any other URP
Level–D codes are squelched.
Write-side Behavior
Two downstream STREAMS messages are recognized and processed by the dkty module:
M_CTL All downstream M_CTL messages are silently freed.
M_IOCTL A number of commands may be sent from user-level processes to the module in the form
of M_IOCTL messages. These commands and requests are described below.
IOCTLS
The following ioctls(2) are processed by the dkty module. All other ioctls(2) are forwarded downstream.
These ioctls(2) are provided for compatibility with the standard terminal interface.
TCGETS The argument is a pointer to a termios(2) structure. The current value of the c_cflag is set
and returned.
TCSETS The argument is a pointer to a termios(2) structure. The value of the c_cflag is used to set
the terminal parameters. If the value of CBAUD is zero, an M_HANGUP message is sent
upstream.
TCSETSW The argument is a pointer to a termios(2) structure. The value of the c_cflag is used to set
the terminal parameters. If the value of CBAUD is zero, an M_HANGUP message is sent
upstream.
TCSETSF The argument is a pointer to a termios(2) structure. An M_FLUSH message is sent
downstream and the value of the c_cflag is used to set the terminal parameters. If the value
of CBAUD is zero, an M_HANGUP message is sent upstream.
TCGETA The argument is a pointer to a termio(7) structure. The current value of the c_cflag is set
and returned.