/*
* flowstat
*
* Check for changes to flow control
*/
void
flowstat(void)
{
if (his_state_is_will(TELOPT_LFLOW)) {
if (tty_flowmode() != flowmode) {
flowmode = tty_flowmode();
output_data("%c%c%c%c%c%c",
IAC, SB, TELOPT_LFLOW,
flowmode ? LFLOW_ON : LFLOW_OFF,
IAC, SE);
}
if (tty_restartany() != restartany) {
restartany = tty_restartany();
output_data("%c%c%c%c%c%c",
IAC, SB, TELOPT_LFLOW,
restartany ? LFLOW_RESTART_ANY
: LFLOW_RESTART_XON,
IAC, SE);
}
}
}
/*
* flowstat
*
* Check for changes to flow control
*/
void
flowstat()
{
if (his_state_is_will(TELOPT_LFLOW)) {
if (tty_flowmode() != flowmode) {
flowmode = tty_flowmode();
(void) sprintf(nfrontp, "%c%c%c%c%c%c",
IAC, SB, TELOPT_LFLOW,
flowmode ? LFLOW_ON : LFLOW_OFF,
IAC, SE);
nfrontp += 6;
}
if (tty_restartany() != restartany) {
restartany = tty_restartany();
(void) sprintf(nfrontp, "%c%c%c%c%c%c",
IAC, SB, TELOPT_LFLOW,
restartany ? LFLOW_RESTART_ANY
: LFLOW_RESTART_XON,
IAC, SE);
nfrontp += 6;
}
}
}
/*
* localstat
*
* This function handles all management of linemode.
*
* Linemode allows the client to do the local editing of data
* and send only complete lines to the server. Linemode state is
* based on the state of the pty driver. If the pty is set for
* external processing, then we can use linemode. Further, if we
* can use real linemode, then we can look at the edit control bits
* in the pty to determine what editing the client should do.
*
* Linemode support uses the following state flags to keep track of
* current and desired linemode state.
* alwayslinemode : true if -l was specified on the telnetd
* command line. It means to have linemode on as much as
* possible.
*
* lmodetype: signifies whether the client can
* handle real linemode, or if use of kludgeomatic linemode
* is preferred. It will be set to one of the following:
* REAL_LINEMODE : use linemode option
* KLUDGE_LINEMODE : use kludge linemode
* NO_LINEMODE : client is ignorant of linemode
*
* linemode, uselinemode : linemode is true if linemode
* is currently on, uselinemode is the state that we wish
* to be in. If another function wishes to turn linemode
* on or off, it sets or clears uselinemode.
*
* editmode, useeditmode : like linemode/uselinemode, but
* these contain the edit mode states (edit and trapsig).
*
* The state variables correspond to some of the state information
* in the pty.
* linemode:
* In real linemode, this corresponds to whether the pty
* expects external processing of incoming data.
* In kludge linemode, this more closely corresponds to the
* whether normal processing is on or not. (ICANON in
* system V, or COOKED mode in BSD.)
* If the -l option was specified (alwayslinemode), then
* an attempt is made to force external processing on at
* all times.
*
* The following heuristics are applied to determine linemode
* handling within the server.
* 1) Early on in starting up the server, an attempt is made
* to negotiate the linemode option. If this succeeds
* then lmodetype is set to REAL_LINEMODE and all linemode
* processing occurs in the context of the linemode option.
* 2) If the attempt to negotiate the linemode option failed,
* then we try to use kludge linemode. We test for this
* capability by sending "do Timing Mark". If a positive
* response comes back, then we assume that the client
* understands kludge linemode (ech!) and the
* lmodetype flag is set to KLUDGE_LINEMODE.
* 3) Otherwise, linemode is not supported at all and
* lmodetype remains set to NO_LINEMODE (which happens
* to be 0 for convenience).
* 4) At any time a command arrives that implies a higher
* state of linemode support in the client, we move to that
* linemode support.
*
* A short explanation of kludge linemode is in order here.
* 1) The heuristic to determine support for kludge linemode
* is to send a do timing mark. We assume that a client
* that supports timing marks also supports kludge linemode.
* A risky proposition at best.
* 2) Further negotiation of linemode is done by changing the
* the server's state regarding SGA. If server will SGA,
* then linemode is off, if server won't SGA, then linemode
* is on.
*/
void localstat()
{
void netflush();
int need_will_echo = 0;
/*
* Check for state of BINARY options.
*/
if (tty_isbinaryin()) {
if (his_want_state_is_wont(TELOPT_BINARY))
send_do(TELOPT_BINARY, 1);
}
else {
if (his_want_state_is_will(TELOPT_BINARY))
send_dont(TELOPT_BINARY, 1);
}
if (tty_isbinaryout()) {
if (my_want_state_is_wont(TELOPT_BINARY))
send_will(TELOPT_BINARY, 1);
}
else {
if (my_want_state_is_will(TELOPT_BINARY))
send_wont(TELOPT_BINARY, 1);
}
/*
* Check for changes to flow control if client supports it.
*/
if (his_state_is_will(TELOPT_LFLOW)) {
if (tty_flowmode() != flowmode) {
flowmode = tty_flowmode();
(void)netoprintf("%c%c%c%c%c%c", IAC, SB,
TELOPT_LFLOW, flowmode, IAC, SE);
}
}
/*
* Check linemode on/off state
*/
uselinemode = tty_linemode();
/*
* If alwayslinemode is on, and pty is changing to turn it off, then
* force linemode back on.
*/
if (alwayslinemode && linemode && !uselinemode) {
uselinemode = 1;
tty_setlinemode(uselinemode);
}
/*
* Do echo mode handling as soon as we know what the
* linemode is going to be.
* If the pty has echo turned off, then tell the client that
* the server will echo. If echo is on, then the server
* will echo if in character mode, but in linemode the
* client should do local echoing. The state machine will
* not send anything if it is unnecessary, so don't worry
* about that here.
*
* If we need to send the WILL ECHO (because echo is off),
* then delay that until after we have changed the MODE.
* This way, when the user is turning off both editing
* and echo, the client will get editing turned off first.
* This keeps the client from going into encryption mode
* and then right back out if it is doing auto-encryption
* when passwords are being typed.
*/
if (uselinemode) {
if (tty_isecho())
send_wont(TELOPT_ECHO, 1);
else
need_will_echo = 1;
}
/*
* If linemode is being turned off, send appropriate
* command and then we're all done.
*/
if (!uselinemode && linemode) {
#ifdef KLUDGELINEMODE
if (lmodetype == REAL_LINEMODE) {
#endif /* KLUDGELINEMODE */
send_dont(TELOPT_LINEMODE, 1);
#ifdef KLUDGELINEMODE
}
else if (lmodetype == KLUDGE_LINEMODE)
send_will(TELOPT_SGA, 1);
#endif /* KLUDGELINEMODE */
send_will(TELOPT_ECHO, 1);
linemode = uselinemode;
goto done;
}
#ifdef KLUDGELINEMODE
/*
* If using real linemode check edit modes for possible later use.
* If we are in kludge linemode, do the SGA negotiation.
*/
if (lmodetype == REAL_LINEMODE) {
#endif /* KLUDGELINEMODE */
useeditmode = 0;
if (tty_isediting())
useeditmode |= MODE_EDIT;
if (tty_istrapsig())
useeditmode |= MODE_TRAPSIG;
if (tty_issofttab())
useeditmode |= MODE_SOFT_TAB;
if (tty_islitecho())
useeditmode |= MODE_LIT_ECHO;
#ifdef KLUDGELINEMODE
}
else if (lmodetype == KLUDGE_LINEMODE) {
if (tty_isediting() && uselinemode)
send_wont(TELOPT_SGA, 1);
else
send_will(TELOPT_SGA, 1);
}
#endif /* KLUDGELINEMODE */
/*
* Negotiate linemode on if pty state has changed to turn it on.
* Send appropriate command and send along edit mode, then all done.
*/
if (uselinemode && !linemode) {
#ifdef KLUDGELINEMODE
if (lmodetype == KLUDGE_LINEMODE) {
send_wont(TELOPT_SGA, 1);
}
else if (lmodetype == REAL_LINEMODE) {
#endif /* KLUDGELINEMODE */
send_do(TELOPT_LINEMODE, 1);
/* send along edit modes */
(void)netoprintf("%c%c%c%c%c%c%c", IAC, SB,
TELOPT_LINEMODE, LM_MODE, useeditmode,
IAC, SE);
editmode = useeditmode;
#ifdef KLUDGELINEMODE
}
#endif /* KLUDGELINEMODE */
linemode = uselinemode;
goto done;
}
#ifdef KLUDGELINEMODE
/*
* None of what follows is of any value if not using
* real linemode.
*/
if (lmodetype < REAL_LINEMODE)
goto done;
#endif /* KLUDGELINEMODE */
if (linemode && his_state_is_will(TELOPT_LINEMODE)) {
/*
* If edit mode changed, send edit mode.
*/
if (useeditmode != editmode) {
/*
* Send along appropriate edit mode mask.
*/
(void)netoprintf("%c%c%c%c%c%c%c", IAC, SB,
TELOPT_LINEMODE, LM_MODE, useeditmode,
IAC, SE);
editmode = useeditmode;
}
/*
* Check for changes to special characters in use.
*/
start_slc(0);
check_slc();
(void)end_slc(0);
}
done:
if (need_will_echo)
send_will(TELOPT_ECHO, 1);
/*
* Some things should be deferred until after the pty state has
* been set by the local process. Do those things that have been
* deferred now. This only happens once.
*/
if (_terminit == 0) {
_terminit = 1;
defer_terminit();
}
netflush();
set_termbuf();
return;
} /* end of localstat */
