4.3BSD-Reno/src/libexec/telnetd/state.c
/*
* Copyright (c) 1989 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted provided
* that: (1) source distributions retain this entire copyright notice and
* comment, and (2) distributions including binaries display the following
* acknowledgement: ``This product includes software developed by the
* University of California, Berkeley and its contributors'' in the
* documentation or other materials provided with the distribution and in
* all advertising materials mentioning features or use of this software.
* Neither the name of the University nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef lint
static char sccsid[] = "@(#)state.c 5.7 (Berkeley) 6/28/90";
#endif /* not lint */
#include "telnetd.h"
char doopt[] = { IAC, DO, '%', 'c', 0 };
char dont[] = { IAC, DONT, '%', 'c', 0 };
char will[] = { IAC, WILL, '%', 'c', 0 };
char wont[] = { IAC, WONT, '%', 'c', 0 };
int not42 = 1;
/*
* Buffer for sub-options, and macros
* for suboptions buffer manipulations
*/
char subbuffer[100], *subpointer= subbuffer, *subend= subbuffer;
#define SB_CLEAR() subpointer = subbuffer;
#define SB_TERM() { subend = subpointer; SB_CLEAR(); }
#define SB_ACCUM(c) if (subpointer < (subbuffer+sizeof subbuffer)) { \
*subpointer++ = (c); \
}
#define SB_GET() ((*subpointer++)&0xff)
#define SB_EOF() (subpointer >= subend)
#define SB_LEN() (subend - subpointer)
/*
* State for recv fsm
*/
#define TS_DATA 0 /* base state */
#define TS_IAC 1 /* look for double IAC's */
#define TS_CR 2 /* CR-LF ->'s CR */
#define TS_SB 3 /* throw away begin's... */
#define TS_SE 4 /* ...end's (suboption negotiation) */
#define TS_WILL 5 /* will option negotiation */
#define TS_WONT 6 /* wont " */
#define TS_DO 7 /* do " */
#define TS_DONT 8 /* dont " */
telrcv()
{
register int c;
static int state = TS_DATA;
#if defined(CRAY2) && defined(UNICOS5)
char *opfrontp = pfrontp;
#endif
while (ncc > 0) {
if ((&ptyobuf[BUFSIZ] - pfrontp) < 2)
break;
c = *netip++ & 0377, ncc--;
switch (state) {
case TS_CR:
state = TS_DATA;
/* Strip off \n or \0 after a \r */
if ((c == 0) || (c == '\n')) {
break;
}
/* FALL THROUGH */
case TS_DATA:
if (c == IAC) {
state = TS_IAC;
break;
}
/*
* We now map \r\n ==> \r for pragmatic reasons.
* Many client implementations send \r\n when
* the user hits the CarriageReturn key.
*
* We USED to map \r\n ==> \n, since \r\n says
* that we want to be in column 1 of the next
* printable line, and \n is the standard
* unix way of saying that (\r is only good
* if CRMOD is set, which it normally is).
*/
if ((c == '\r') && his_state_is_wont(TELOPT_BINARY)) {
/*
* If we are operating in linemode,
* convert to local end-of-line.
*/
if ((linemode) && (ncc > 0)&&('\n' == *netip)) {
netip++; ncc--;
c = '\n';
} else {
state = TS_CR;
}
}
*pfrontp++ = c;
break;
case TS_IAC:
gotiac: switch (c) {
/*
* Send the process on the pty side an
* interrupt. Do this with a NULL or
* interrupt char; depending on the tty mode.
*/
case IP:
#ifdef DIAGNOSTICS
if (diagnostic & TD_OPTIONS)
printoption("td: recv IAC", c);
#endif /* DIAGNOSTICS */
interrupt();
break;
case BREAK:
#ifdef DIAGNOSTICS
if (diagnostic & TD_OPTIONS)
printoption("td: recv IAC", c);
#endif /* DIAGNOSTICS */
sendbrk();
break;
/*
* Are You There?
*/
case AYT:
#ifdef DIAGNOSTICS
if (diagnostic & TD_OPTIONS)
printoption("td: recv IAC", c);
#endif /* DIAGNOSTICS */
(void) strcpy(nfrontp, "\r\n[Yes]\r\n");
nfrontp += 9;
break;
/*
* Abort Output
*/
case AO:
{
#ifdef DIAGNOSTICS
if (diagnostic & TD_OPTIONS)
printoption("td: recv IAC", c);
#endif /* DIAGNOSTICS */
ptyflush(); /* half-hearted */
init_termbuf();
if (slctab[SLC_AO].sptr &&
*slctab[SLC_AO].sptr != (cc_t)-1) {
*pfrontp++ =
(unsigned char)*slctab[SLC_AO].sptr;
}
netclear(); /* clear buffer back */
*nfrontp++ = IAC;
*nfrontp++ = DM;
neturg = nfrontp-1; /* off by one XXX */
#ifdef DIAGNOSTICS
if (diagnostic & TD_OPTIONS)
printoption("td: send IAC", DM);
#endif /* DIAGNOSTICS */
break;
}
/*
* Erase Character and
* Erase Line
*/
case EC:
case EL:
{
cc_t ch;
#ifdef DIAGNOSTICS
if (diagnostic & TD_OPTIONS)
printoption("td: recv IAC", c);
#endif /* DIAGNOSTICS */
ptyflush(); /* half-hearted */
init_termbuf();
if (c == EC)
ch = *slctab[SLC_EC].sptr;
else
ch = *slctab[SLC_EL].sptr;
if (ch != (cc_t)-1)
*pfrontp++ = (unsigned char)ch;
break;
}
/*
* Check for urgent data...
*/
case DM:
#ifdef DIAGNOSTICS
if (diagnostic & TD_OPTIONS)
printoption("td: recv IAC", c);
#endif /* DIAGNOSTICS */
SYNCHing = stilloob(net);
settimer(gotDM);
break;
/*
* Begin option subnegotiation...
*/
case SB:
state = TS_SB;
SB_CLEAR();
continue;
case WILL:
state = TS_WILL;
continue;
case WONT:
state = TS_WONT;
continue;
case DO:
state = TS_DO;
continue;
case DONT:
state = TS_DONT;
continue;
case EOR:
if (his_state_is_will(TELOPT_EOR))
doeof();
break;
/*
* Handle RFC 10xx Telnet linemode option additions
* to command stream (EOF, SUSP, ABORT).
*/
case xEOF:
doeof();
break;
case SUSP:
sendsusp();
break;
case ABORT:
sendbrk();
break;
case IAC:
*pfrontp++ = c;
break;
}
state = TS_DATA;
break;
case TS_SB:
if (c == IAC) {
state = TS_SE;
} else {
SB_ACCUM(c);
}
break;
case TS_SE:
if (c != SE) {
if (c != IAC) {
/*
* bad form of suboption negotiation.
* handle it in such a way as to avoid
* damage to local state. Parse
* suboption buffer found so far,
* then treat remaining stream as
* another command sequence.
*/
#ifdef DIAGNOSTICS
SB_ACCUM(IAC);
SB_ACCUM(c);
subpointer -= 2;
#endif
SB_TERM();
suboption();
state = TS_IAC;
goto gotiac;
}
SB_ACCUM(c);
state = TS_SB;
} else {
#ifdef DIAGNOSTICS
SB_ACCUM(IAC);
SB_ACCUM(SE);
subpointer -= 2;
#endif
SB_TERM();
suboption(); /* handle sub-option */
state = TS_DATA;
}
break;
case TS_WILL:
willoption(c);
state = TS_DATA;
continue;
case TS_WONT:
wontoption(c);
state = TS_DATA;
continue;
case TS_DO:
dooption(c);
state = TS_DATA;
continue;
case TS_DONT:
dontoption(c);
state = TS_DATA;
continue;
default:
syslog(LOG_ERR, "telnetd: panic state=%d\n", state);
printf("telnetd: panic state=%d\n", state);
exit(1);
}
}
#if defined(CRAY2) && defined(UNICOS5)
if (!linemode) {
char xptyobuf[BUFSIZ+NETSLOP];
char xbuf2[BUFSIZ];
register char *cp;
int n = pfrontp - opfrontp, oc;
bcopy(opfrontp, xptyobuf, n);
pfrontp = opfrontp;
pfrontp += term_input(xptyobuf, pfrontp, n, BUFSIZ+NETSLOP,
xbuf2, &oc, BUFSIZ);
for (cp = xbuf2; oc > 0; --oc)
if ((*nfrontp++ = *cp++) == IAC)
*nfrontp++ = IAC;
}
#endif /* defined(CRAY2) && defined(UNICOS5) */
} /* end of telrcv */
/*
* The will/wont/do/dont state machines are based on Dave Borman's
* Telnet option processing state machine.
*
* These correspond to the following states:
* my_state = the last negotiated state
* want_state = what I want the state to go to
* want_resp = how many requests I have sent
* All state defaults are negative, and resp defaults to 0.
*
* When initiating a request to change state to new_state:
*
* if ((want_resp == 0 && new_state == my_state) || want_state == new_state) {
* do nothing;
* } else {
* want_state = new_state;
* send new_state;
* want_resp++;
* }
*
* When receiving new_state:
*
* if (want_resp) {
* want_resp--;
* if (want_resp && (new_state == my_state))
* want_resp--;
* }
* if ((want_resp == 0) && (new_state != want_state)) {
* if (ok_to_switch_to new_state)
* want_state = new_state;
* else
* want_resp++;
* send want_state;
* }
* my_state = new_state;
*
* Note that new_state is implied in these functions by the function itself.
* will and do imply positive new_state, wont and dont imply negative.
*
* Finally, there is one catch. If we send a negative response to a
* positive request, my_state will be the positive while want_state will
* remain negative. my_state will revert to negative when the negative
* acknowlegment arrives from the peer. Thus, my_state generally tells
* us not only the last negotiated state, but also tells us what the peer
* wants to be doing as well. It is important to understand this difference
* as we may wish to be processing data streams based on our desired state
* (want_state) or based on what the peer thinks the state is (my_state).
*
* This all works fine because if the peer sends a positive request, the data
* that we receive prior to negative acknowlegment will probably be affected
* by the positive state, and we can process it as such (if we can; if we
* can't then it really doesn't matter). If it is that important, then the
* peer probably should be buffering until this option state negotiation
* is complete.
*
*/
send_do(option, init)
int option, init;
{
if (init) {
if ((do_dont_resp[option] == 0 && his_state_is_will(option)) ||
his_want_state_is_will(option))
return;
/*
* Special case for TELOPT_TM: We send a DO, but pretend
* that we sent a DONT, so that we can send more DOs if
* we want to.
*/
if (option == TELOPT_TM)
set_his_want_state_wont(option);
else
set_his_want_state_will(option);
do_dont_resp[option]++;
}
(void) sprintf(nfrontp, doopt, option);
nfrontp += sizeof (dont) - 2;
#ifdef DIAGNOSTICS
/*
* Report sending option to other side.
*/
if (diagnostic & TD_OPTIONS) {
printoption("td: send do", option);
}
#endif /* DIAGNOSTICS */
}
willoption(option)
int option;
{
int changeok = 0;
/*
* process input from peer.
*/
#ifdef DIAGNOSTICS
/*
* Report receiving option from other side.
*/
if (diagnostic & TD_OPTIONS) {
printoption("td: recv will", option);
}
#endif /* DIAGNOSTICS */
if (do_dont_resp[option]) {
do_dont_resp[option]--;
if (do_dont_resp[option] && his_state_is_will(option))
do_dont_resp[option]--;
}
if (do_dont_resp[option] == 0) {
if (his_want_state_is_wont(option)) {
switch (option) {
case TELOPT_BINARY:
init_termbuf();
tty_binaryin(1);
set_termbuf();
changeok++;
break;
case TELOPT_ECHO:
/*
* See comments below for more info.
*/
not42 = 0; /* looks like a 4.2 system */
break;
case TELOPT_TM:
#if defined(LINEMODE) && defined(KLUDGELINEMODE)
/*
* This telnetd implementation does not really
* support timing marks, it just uses them to
* support the kludge linemode stuff. If we
* receive a will or wont TM in response to our
* do TM request that may have been sent to
* determine kludge linemode support, process
* it, otherwise TM should get a negative
* response back.
*/
/*
* Handle the linemode kludge stuff.
* If we are not currently supporting any
* linemode at all, then we assume that this
* is the client telling us to use kludge
* linemode in response to our query. Set the
* linemode type that is to be supported, note
* that the client wishes to use linemode, and
* eat the will TM as though it never arrived.
*/
if (lmodetype < KLUDGE_LINEMODE) {
lmodetype = KLUDGE_LINEMODE;
clientstat(TELOPT_LINEMODE, WILL, 0);
send_wont(TELOPT_SGA, 1);
}
#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
/*
* We never respond to a WILL TM, and
* we leave the state WONT.
*/
return;
case TELOPT_LFLOW:
/*
* If we are going to support flow control
* option, then don't worry peer that we can't
* change the flow control characters.
*/
slctab[SLC_XON].defset.flag &= ~SLC_LEVELBITS;
slctab[SLC_XON].defset.flag |= SLC_DEFAULT;
slctab[SLC_XOFF].defset.flag &= ~SLC_LEVELBITS;
slctab[SLC_XOFF].defset.flag |= SLC_DEFAULT;
case TELOPT_TTYPE:
case TELOPT_SGA:
case TELOPT_NAWS:
case TELOPT_TSPEED:
case TELOPT_XDISPLOC:
case TELOPT_ENVIRON:
changeok++;
break;
#ifdef LINEMODE
case TELOPT_LINEMODE:
/*
* Local processing of 'will linemode' should
* occur after placing 'do linemode' in the data
* stream, because we may wish to send other
* linemode related messages. So, we duplicate
* the other three lines of code here, and then
* return.
*/
set_his_want_state_will(option);
send_do(option, 0);
set_his_state_will(option);
# ifdef KLUDGELINEMODE
/*
* Note client's desire to use linemode.
*/
lmodetype = REAL_LINEMODE;
# endif /* KLUDGELINEMODE */
clientstat(TELOPT_LINEMODE, WILL, 0);
return;
#endif /* LINEMODE */
default:
break;
}
if (changeok) {
set_his_want_state_will(option);
send_do(option, 0);
} else {
do_dont_resp[option]++;
send_dont(option, 0);
}
} else {
/*
* Option processing that should happen when
* we receive conformation of a change in
* state that we had requested.
*/
switch (option) {
case TELOPT_ECHO:
not42 = 0; /* looks like a 4.2 system */
/*
* Egads, he responded "WILL ECHO". Turn
* it off right now!
*/
send_dont(option, 1);
/*
* "WILL ECHO". Kludge upon kludge!
* A 4.2 client is now echoing user input at
* the tty. This is probably undesireable and
* it should be stopped. The client will
* respond WONT TM to the DO TM that we send to
* check for kludge linemode. When the WONT TM
* arrives, linemode will be turned off and a
* change propogated to the pty. This change
* will cause us to process the new pty state
* in localstat(), which will notice that
* linemode is off and send a WILL ECHO
* so that we are properly in character mode and
* all is well.
*/
break;
#ifdef LINEMODE
case TELOPT_LINEMODE:
# ifdef KLUDGELINEMODE
/*
* Note client's desire to use linemode.
*/
lmodetype = REAL_LINEMODE;
# endif /* KLUDGELINEMODE */
clientstat(TELOPT_LINEMODE, WILL, 0);
#endif /* LINEMODE */
}
}
}
set_his_state_will(option);
} /* end of willoption */
send_dont(option, init)
int option, init;
{
if (init) {
if ((do_dont_resp[option] == 0 && his_state_is_wont(option)) ||
his_want_state_is_wont(option))
return;
set_his_want_state_wont(option);
do_dont_resp[option]++;
}
(void) sprintf(nfrontp, dont, option);
nfrontp += sizeof (doopt) - 2;
#ifdef DIAGNOSTICS
/*
* Report sending option to other side.
*/
if (diagnostic & TD_OPTIONS) {
printoption("td: send dont", option);
}
#endif /* DIAGNOSTICS */
}
wontoption(option)
int option;
{
/*
* Process client input.
*/
#ifdef DIAGNOSTICS
/*
* Report receiving option from other side.
*/
if (diagnostic & TD_OPTIONS) {
printoption("td: recv wont", option);
}
#endif /* DIAGNOSTICS */
if (do_dont_resp[option]) {
do_dont_resp[option]--;
if (do_dont_resp[option] && his_state_is_wont(option))
do_dont_resp[option]--;
}
if (do_dont_resp[option] == 0) {
if (his_want_state_is_will(option)) {
/* it is always ok to change to negative state */
switch (option) {
case TELOPT_ECHO:
not42 = 1; /* doesn't seem to be a 4.2 system */
break;
case TELOPT_BINARY:
init_termbuf();
tty_binaryin(0);
set_termbuf();
break;
#ifdef LINEMODE
case TELOPT_LINEMODE:
# ifdef KLUDGELINEMODE
/*
* If real linemode is supported, then client is
* asking to turn linemode off.
*/
if (lmodetype != REAL_LINEMODE)
break;
lmodetype = KLUDGE_LINEMODE;
# endif /* KLUDGELINEMODE */
clientstat(TELOPT_LINEMODE, WONT, 0);
break;
#endif LINEMODE
case TELOPT_TM:
/*
* If we get a WONT TM, and had sent a DO TM,
* don't respond with a DONT TM, just leave it
* as is. Short circut the state machine to
* achive this.
*/
set_his_want_state_wont(TELOPT_TM);
return;
case TELOPT_LFLOW:
/*
* If we are not going to support flow control
* option, then let peer know that we can't
* change the flow control characters.
*/
slctab[SLC_XON].defset.flag &= ~SLC_LEVELBITS;
slctab[SLC_XON].defset.flag |= SLC_CANTCHANGE;
slctab[SLC_XOFF].defset.flag &= ~SLC_LEVELBITS;
slctab[SLC_XOFF].defset.flag |= SLC_CANTCHANGE;
break;
/*
* For options that we might spin waiting for
* sub-negotiation, if the client turns off the
* option rather than responding to the request,
* we have to treat it here as if we got a response
* to the sub-negotiation, (by updating the timers)
* so that we'll break out of the loop.
*/
case TELOPT_TTYPE:
settimer(ttypesubopt);
break;
case TELOPT_TSPEED:
settimer(tspeedsubopt);
break;
case TELOPT_XDISPLOC:
settimer(xdisplocsubopt);
break;
case TELOPT_ENVIRON:
settimer(environsubopt);
break;
default:
break;
}
set_his_want_state_wont(option);
if (his_state_is_will(option))
send_dont(option, 0);
} else {
switch (option) {
case TELOPT_TM:
#if defined(LINEMODE) && defined(KLUDGELINEMODE)
if (lmodetype < REAL_LINEMODE) {
lmodetype = NO_LINEMODE;
clientstat(TELOPT_LINEMODE, WONT, 0);
send_will(TELOPT_SGA, 1);
/*@*/ send_will(TELOPT_ECHO, 1);
}
#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
default:
break;
}
}
}
set_his_state_wont(option);
} /* end of wontoption */
send_will(option, init)
int option, init;
{
if (init) {
if ((will_wont_resp[option] == 0 && my_state_is_will(option))||
my_want_state_is_will(option))
return;
set_my_want_state_will(option);
will_wont_resp[option]++;
}
(void) sprintf(nfrontp, will, option);
nfrontp += sizeof (doopt) - 2;
#ifdef DIAGNOSTICS
/*
* Report sending option to other side.
*/
if (diagnostic & TD_OPTIONS) {
printoption("td: send will", option);
}
#endif /* DIAGNOSTICS */
}
dooption(option)
int option;
{
int changeok = 0;
/*
* Process client input.
*/
#ifdef DIAGNOSTICS
/*
* Report receiving option from other side.
*/
if (diagnostic & TD_OPTIONS) {
printoption("td: recv do", option);
}
#endif /* DIAGNOSTICS */
if (will_wont_resp[option]) {
will_wont_resp[option]--;
if (will_wont_resp[option] && my_state_is_will(option))
will_wont_resp[option]--;
}
if ((will_wont_resp[option] == 0) && (my_want_state_is_wont(option))) {
switch (option) {
case TELOPT_ECHO:
#ifdef LINEMODE
if (lmodetype == NO_LINEMODE) {
#endif
init_termbuf();
tty_setecho(1);
set_termbuf();
#ifdef LINEMODE
}
#endif
changeok++;
break;
case TELOPT_BINARY:
init_termbuf();
tty_binaryout(1);
set_termbuf();
changeok++;
break;
case TELOPT_SGA:
#if defined(LINEMODE) && defined(KLUDGELINEMODE)
/*
* If kludge linemode is in use, then we must
* process an incoming do SGA for linemode
* purposes.
*/
if (lmodetype == KLUDGE_LINEMODE) {
/*
* Receipt of "do SGA" in kludge
* linemode is the peer asking us to
* turn off linemode. Make note of
* the request.
*/
clientstat(TELOPT_LINEMODE, WONT, 0);
/*
* If linemode did not get turned off
* then don't tell peer that we did.
* Breaking here forces a wont SGA to
* be returned.
*/
if (linemode)
break;
}
#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
changeok++;
break;
case TELOPT_STATUS:
changeok++;
break;
case TELOPT_TM:
/*
* Special case for TM. We send a WILL, but
* pretend we sent a WONT.
*/
send_will(option, 0);
set_my_want_state_wont(option);
set_my_state_wont(option);
return;
case TELOPT_LINEMODE:
case TELOPT_TTYPE:
case TELOPT_NAWS:
case TELOPT_TSPEED:
case TELOPT_LFLOW:
case TELOPT_XDISPLOC:
case TELOPT_ENVIRON:
default:
break;
}
if (changeok) {
set_my_want_state_will(option);
send_will(option, 0);
} else {
will_wont_resp[option]++;
send_wont(option, 0);
}
}
set_my_state_will(option);
} /* end of dooption */
send_wont(option, init)
int option, init;
{
if (init) {
if ((will_wont_resp[option] == 0 && my_state_is_wont(option)) ||
my_want_state_is_wont(option))
return;
set_my_want_state_wont(option);
will_wont_resp[option]++;
}
(void) sprintf(nfrontp, wont, option);
nfrontp += sizeof (wont) - 2;
#ifdef DIAGNOSTICS
/*
* Report sending option to other side.
*/
if (diagnostic & TD_OPTIONS) {
printoption("td: send wont", option);
}
#endif /* DIAGNOSTICS */
}
dontoption(option)
int option;
{
/*
* Process client input.
*/
#ifdef DIAGNOSTICS
/*
* Report receiving option from other side.
*/
if (diagnostic & TD_OPTIONS) {
printoption("td: recv dont", option);
}
#endif /* DIAGNOSTICS */
if (will_wont_resp[option]) {
will_wont_resp[option]--;
if (will_wont_resp[option] && my_state_is_wont(option))
will_wont_resp[option]--;
}
if ((will_wont_resp[option] == 0) && (my_want_state_is_will(option))) {
switch (option) {
case TELOPT_BINARY:
init_termbuf();
tty_binaryout(0);
set_termbuf();
break;
case TELOPT_ECHO: /* we should stop echoing */
#ifdef LINEMODE
if (lmodetype == NO_LINEMODE) {
#endif
init_termbuf();
tty_setecho(0);
set_termbuf();
#ifdef LINEMODE
}
#endif
break;
case TELOPT_SGA:
#if defined(LINEMODE) && defined(KLUDGELINEMODE)
/*
* If kludge linemode is in use, then we
* must process an incoming do SGA for
* linemode purposes.
*/
if (lmodetype == KLUDGE_LINEMODE) {
/*
* The client is asking us to turn
* linemode on.
*/
clientstat(TELOPT_LINEMODE, WILL, 0);
/*
* If we did not turn line mode on,
* then what do we say? Will SGA?
* This violates design of telnet.
* Gross. Very Gross.
*/
}
#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
default:
break;
}
set_my_want_state_wont(option);
if (my_state_is_will(option))
send_wont(option, 0);
}
set_my_state_wont(option);
} /* end of dontoption */
/*
* suboption()
*
* Look at the sub-option buffer, and try to be helpful to the other
* side.
*
* Currently we recognize:
*
* Terminal type is
* Linemode
* Window size
* Terminal speed
*/
suboption()
{
register int subchar;
extern void unsetenv();
#ifdef DIAGNOSTICS
/*
* Report receiving option from other side.
*/
if (diagnostic & TD_OPTIONS) {
netflush(); /* get rid of anything waiting to go out */
printsub("td: recv", subpointer, SB_LEN()+2);
}
#endif DIAGNOSTIC
subchar = SB_GET();
switch (subchar) {
case TELOPT_TSPEED: {
register int xspeed, rspeed;
if (his_state_is_wont(TELOPT_TSPEED)) /* Ignore if option disabled */
break;
settimer(tspeedsubopt);
if (SB_EOF() || SB_GET() != TELQUAL_IS)
return;
xspeed = atoi(subpointer);
while (SB_GET() != ',' && !SB_EOF());
if (SB_EOF())
return;
rspeed = atoi(subpointer);
clientstat(TELOPT_TSPEED, xspeed, rspeed);
break;
} /* end of case TELOPT_TSPEED */
case TELOPT_TTYPE: { /* Yaaaay! */
static char terminalname[41];
if (his_state_is_wont(TELOPT_TTYPE)) /* Ignore if option disabled */
break;
settimer(ttypesubopt);
if (SB_GET() != TELQUAL_IS) {
return; /* ??? XXX but, this is the most robust */
}
terminaltype = terminalname;
while ((terminaltype < (terminalname + sizeof terminalname-1)) &&
!SB_EOF()) {
register int c;
c = SB_GET();
if (isupper(c)) {
c = tolower(c);
}
*terminaltype++ = c; /* accumulate name */
}
*terminaltype = 0;
terminaltype = terminalname;
break;
} /* end of case TELOPT_TTYPE */
case TELOPT_NAWS: {
register int xwinsize, ywinsize;
if (his_state_is_wont(TELOPT_NAWS)) /* Ignore if option disabled */
break;
if (SB_EOF())
return;
xwinsize = SB_GET() << 8;
if (SB_EOF())
return;
xwinsize |= SB_GET();
if (SB_EOF())
return;
ywinsize = SB_GET() << 8;
if (SB_EOF())
return;
ywinsize |= SB_GET();
clientstat(TELOPT_NAWS, xwinsize, ywinsize);
break;
} /* end of case TELOPT_NAWS */
#ifdef LINEMODE
case TELOPT_LINEMODE: {
register int request;
if (his_state_is_wont(TELOPT_LINEMODE)) /* Ignore if option disabled */
break;
/*
* Process linemode suboptions.
*/
if (SB_EOF()) break; /* garbage was sent */
request = SB_GET(); /* get will/wont */
if (SB_EOF()) break; /* another garbage check */
if (request == LM_SLC) { /* SLC is not preceeded by WILL or WONT */
/*
* Process suboption buffer of slc's
*/
start_slc(1);
do_opt_slc(subpointer, subend - subpointer);
end_slc(0);
} else if (request == LM_MODE) {
useeditmode = SB_GET(); /* get mode flag */
clientstat(LM_MODE, 0, 0);
}
switch (SB_GET()) { /* what suboption? */
case LM_FORWARDMASK:
/*
* According to spec, only server can send request for
* forwardmask, and client can only return a positive response.
* So don't worry about it.
*/
default:
break;
}
break;
} /* end of case TELOPT_LINEMODE */
#endif
case TELOPT_STATUS: {
int mode;
mode = SB_GET();
switch (mode) {
case TELQUAL_SEND:
if (my_state_is_will(TELOPT_STATUS))
send_status();
break;
case TELQUAL_IS:
break;
default:
break;
}
break;
} /* end of case TELOPT_STATUS */
case TELOPT_XDISPLOC: {
if (SB_EOF() || SB_GET() != TELQUAL_IS)
return;
settimer(xdisplocsubopt);
subpointer[SB_LEN()] = '\0';
setenv("DISPLAY", subpointer, 1);
break;
} /* end of case TELOPT_XDISPLOC */
case TELOPT_ENVIRON: {
register int c;
register char *cp, *varp, *valp;
if (SB_EOF())
return;
c = SB_GET();
if (c == TELQUAL_IS)
settimer(environsubopt);
else if (c != TELQUAL_INFO)
return;
while (!SB_EOF() && SB_GET() != ENV_VAR)
;
if (SB_EOF())
return;
cp = varp = subpointer;
valp = 0;
while (!SB_EOF()) {
switch (c = SB_GET()) {
case ENV_VALUE:
*cp = '\0';
cp = valp = subpointer;
break;
case ENV_VAR:
*cp = '\0';
if (valp)
setenv(varp, valp, 1);
else
unsetenv(varp);
cp = varp = subpointer;
valp = 0;
break;
case ENV_ESC:
if (SB_EOF())
break;
c = SB_GET();
/* FALL THROUGH */
default:
*cp++ = c;
break;
}
}
*cp = '\0';
if (valp)
setenv(varp, valp, 1);
else
unsetenv(varp);
break;
} /* end of case TELOPT_ENVIRON */
default:
break;
} /* end of switch */
} /* end of suboption */
#define ADD(c) *ncp++ = c;
#define ADD_DATA(c) { *ncp++ = c; if (c == SE) *ncp++ = c; }
send_status()
{
unsigned char statusbuf[256];
register unsigned char *ncp;
register unsigned char i;
ncp = statusbuf;
netflush(); /* get rid of anything waiting to go out */
ADD(IAC);
ADD(SB);
ADD(TELOPT_STATUS);
ADD(TELQUAL_IS);
for (i = 0; i < NTELOPTS; i++) {
if (my_state_is_will(i)) {
ADD(WILL);
ADD_DATA(i);
if (i == IAC)
ADD(IAC);
}
if (his_state_is_will(i)) {
ADD(DO);
ADD_DATA(i);
if (i == IAC)
ADD(IAC);
}
}
#ifdef LINEMODE
if (his_state_is_will(TELOPT_LINEMODE)) {
unsigned char *cp, *cpe;
int len;
ADD(SB);
ADD(TELOPT_LINEMODE);
ADD(LM_MODE);
ADD_DATA(editmode);
if (editmode == IAC)
ADD(IAC);
ADD(SE);
ADD(SB);
ADD(TELOPT_LINEMODE);
ADD(LM_SLC);
start_slc(0);
send_slc();
len = end_slc(&cp);
for (cpe = cp + len; cp < cpe; cp++)
ADD_DATA(*cp);
ADD(SE);
}
#endif /* LINEMODE */
ADD(IAC);
ADD(SE);
writenet(statusbuf, ncp - statusbuf);
netflush(); /* Send it on its way */
#ifdef DIAGNOSTICS
/*
* Report sending status suboption.
*/
if (diagnostic & TD_OPTIONS) {
printsub("td: send", statusbuf, ncp - statusbuf);
netflush(); /* Send it on its way */
}
#endif DIAGNOSTIC
}
#ifdef NO_SETENV
#include "setenv.c"
#endif