/*
* check_slc
*
* Check the special characters in use and notify the client if any have
* changed. Only those characters that are capable of being changed are
* likely to have changed. If a local change occurs, kick the support level
* and flags up to the defaults.
*/
void check_slc(void) {
int i;
for (i = 1; i <= NSLC; i++) {
#if defined(USE_TERMIO) && (VEOF == VMIN)
/*
* In a perfect world this would be a neat little
* function. But in this world, we should not notify
* client of changes to the VEOF char when
* ICANON is off, because it is not representing
* a special character.
*/
if (i == SLC_EOF) {
if (!tty_isediting()) continue;
else if (slctab[i].sptr) oldeofc = *(slctab[i].sptr);
}
#endif /* USE_TERMIO and VEOF==VMIN */
if (slctab[i].sptr && (*(slctab[i].sptr) != slctab[i].current.val)) {
slctab[i].current.val = *(slctab[i].sptr);
if (*(slctab[i].sptr) == (cc_t)_POSIX_VDISABLE) {
slctab[i].current.flag = SLC_NOSUPPORT;
}
else {
slctab[i].current.flag = slctab[i].defset.flag;
}
add_slc((unsigned char)i, slctab[i].current.flag,
slctab[i].current.val);
}
}
}
/*
* process_slc
*
* Figure out what to do about the client's slc
*/
void process_slc(unsigned char func, unsigned char flag, cc_t val)
{
register int hislevel, mylevel, ack;
/*
* Ensure that we know something about this function
*/
if (func > NSLC) {
add_slc(func, SLC_NOSUPPORT, 0);
return;
}
/*
* Process the special case requests of 0 SLC_DEFAULT 0
* and 0 SLC_VARIABLE 0. Be a little forgiving here, don't
* worry about whether the value is actually 0 or not.
*/
if (func == 0) {
if ((flag = flag & SLC_LEVELBITS) == SLC_DEFAULT) {
default_slc();
send_slc();
}
else if (flag == SLC_VARIABLE) {
send_slc();
}
return;
}
/*
* Appears to be a function that we know something about. So
* get on with it and see what we know.
*/
hislevel = flag & SLC_LEVELBITS;
mylevel = slctab[func].current.flag & SLC_LEVELBITS;
ack = flag & SLC_ACK;
/*
* ignore the command if:
* the function value and level are the same as what we already have;
* or the level is the same and the ack bit is set
*/
if (hislevel == mylevel && (val == slctab[func].current.val || ack)) {
return;
}
else if (ack) {
/*
* If we get here, we got an ack, but the levels don't match.
* This shouldn't happen. If it does, it is probably because
* we have sent two requests to set a variable without getting
* a response between them, and this is the first response.
* So, ignore it, and wait for the next response.
*/
return;
}
else {
change_slc(func, flag, val);
}
}
/*
* send_slc
*
* Write out the current special characters to the client.
*/
void send_slc(void) {
int i;
/*
* Send out list of triplets of special characters
* to client. We only send info on the characters
* that are currently supported.
*/
for (i = 1; i <= NSLC; i++) {
if ((slctab[i].defset.flag & SLC_LEVELBITS) == SLC_NOSUPPORT)
continue;
add_slc((unsigned char)i, slctab[i].current.flag,
slctab[i].current.val);
}
}
/*
* check_slc
*
* Check the special characters in use and notify the client if any have
* changed. Only those characters that are capable of being changed are
* likely to have changed. If a local change occurs, kick the support level
* and flags up to the defaults.
*/
void
check_slc ()
{
register int i;
for (i = 1; i <= NSLC; i++)
{
if (i == SLC_EOF && term_change_eof ())
continue;
if (slctab[i].sptr && (*(slctab[i].sptr) != slctab[i].current.val))
{
slctab[i].current.val = *(slctab[i].sptr);
if (*(slctab[i].sptr) == (cc_t) _POSIX_VDISABLE)
slctab[i].current.flag = SLC_NOSUPPORT;
else
slctab[i].current.flag = slctab[i].defset.flag;
add_slc ((unsigned char) i, slctab[i].current.flag,
slctab[i].current.val);
}
}
} /* check_slc */
/*
* change_slc
*
* Process a request to change one of our special characters.
* Compare client's request with what we are capable of supporting.
*/
void
change_slc (register char func_c, register char flag, register cc_t val)
{
register int func = func_c;
register int hislevel, mylevel;
hislevel = flag & SLC_LEVELBITS;
mylevel = slctab[func].defset.flag & SLC_LEVELBITS;
/*
* If client is setting a function to NOSUPPORT
* or DEFAULT, then we can easily and directly
* accomodate the request.
*/
if (hislevel == SLC_NOSUPPORT)
{
slctab[func].current.flag = flag;
slctab[func].current.val = (cc_t) _POSIX_VDISABLE;
flag |= SLC_ACK;
add_slc (func, flag, val);
return;
}
if (hislevel == SLC_DEFAULT)
{
/*
* Special case here. If client tells us to use
* the default on a function we don't support, then
* return NOSUPPORT instead of what we may have as a
* default level of DEFAULT.
*/
if (mylevel == SLC_DEFAULT)
{
slctab[func].current.flag = SLC_NOSUPPORT;
}
else
{
slctab[func].current.flag = slctab[func].defset.flag;
}
slctab[func].current.val = slctab[func].defset.val;
add_slc (func, slctab[func].current.flag, slctab[func].current.val);
return;
}
/*
* Client wants us to change to a new value or he
* is telling us that he can't change to our value.
* Some of the slc's we support and can change,
* some we do support but can't change,
* and others we don't support at all.
* If we can change it then we have a pointer to
* the place to put the new value, so change it,
* otherwise, continue the negotiation.
*/
if (slctab[func].sptr)
{
/*
* We can change this one.
*/
slctab[func].current.val = val;
*(slctab[func].sptr) = val;
slctab[func].current.flag = flag;
flag |= SLC_ACK;
slcchange = 1;
add_slc (func, flag, val);
}
else
{
/*
* It is not possible for us to support this
* request as he asks.
*
* If our level is DEFAULT, then just ack whatever was
* sent.
*
* If he can't change and we can't change,
* then degenerate to NOSUPPORT.
*
* Otherwise we send our level back to him, (CANTCHANGE
* or NOSUPPORT) and if CANTCHANGE, send
* our value as well.
*/
if (mylevel == SLC_DEFAULT)
{
slctab[func].current.flag = flag;
slctab[func].current.val = val;
flag |= SLC_ACK;
}
else if (hislevel == SLC_CANTCHANGE && mylevel == SLC_CANTCHANGE)
{
flag &= ~SLC_LEVELBITS;
flag |= SLC_NOSUPPORT;
slctab[func].current.flag = flag;
}
else
{
flag &= ~SLC_LEVELBITS;
flag |= mylevel;
slctab[func].current.flag = flag;
if (mylevel == SLC_CANTCHANGE)
{
slctab[func].current.val = slctab[func].defset.val;
val = slctab[func].current.val;
}
}
add_slc (func, flag, val);
}
} /* end of change_slc */
