/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char sccsid[] = "@(#)state.c 8.5 (Berkeley) 5/30/95";
#endif /* not lint */
#include "telnetd.h"
#include <stdarg.h>
/* Format lines for corresponing commands */
unsigned char doopt[] = {IAC, DO, '%', 'c', 0};
unsigned char dont[] = {IAC, DONT, '%', 'c', 0};
unsigned char will[] = {IAC, WILL, '%', 'c', 0};
unsigned char wont[] = {IAC, WONT, '%', 'c', 0};
int not42 = 1;
/*
* Buffer for sub-options, and macros
* for suboptions buffer manipulations
*/
unsigned char subbuffer[512], *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)
#ifdef ENV_HACK
unsigned char *subsave;
#define SB_SAVE() subsave = subpointer;
#define SB_RESTORE() subpointer = subsave;
#endif
/*
* 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 " */
static void
send_eof ()
{
init_termbuf ();
term_send_eof ();
pty_output_byte (slctab[SLC_EOF].sptr ?
(unsigned char) *slctab[SLC_EOF].sptr : '\004');
}
/*
* When we get an AYT, if ^T is enabled, use that. Otherwise,
* just send back "[Yes]".
*/
static void
recv_ayt ()
{
#if defined(SIGINFO) && defined(TCSIG)
if (slctab[SLC_AYT].sptr && *slctab[SLC_AYT].sptr != _POSIX_VDISABLE)
{
ioctl (pty, TCSIG, (char *) SIGINFO);
return;
}
#endif
net_output_data ("\r\n[Yes]\r\n");
}
static void
send_susp ()
{
#ifdef SIGTSTP
ptyflush (); /* half-hearted */
#ifdef TCSIG
ioctl (pty, TCSIG, (char *) SIGTSTP);
#else /* TCSIG */
pty_output_byte (slctab[SLC_SUSP].sptr ?
(unsigned char) *slctab[SLC_SUSP].sptr : '\032');
#endif /* TCSIG */
#endif /* SIGTSTP */
}
/*
* Send quit to process on other side of pty.
* If it is in raw mode, just write NULL;
* otherwise, write quit char.
*/
static void
send_brk ()
{
ptyflush (); /* half-hearted */
#ifdef TCSIG
ioctl (pty, TCSIG, (char *) SIGQUIT);
#else /* TCSIG */
init_termbuf ();
pty_output_byte (slctab[SLC_ABORT].sptr ?
(unsigned char) *slctab[SLC_ABORT].sptr : '\034');
#endif /* TCSIG */
}
/*
* Send interrupt to process on other side of pty.
* If it is in raw mode, just write NULL;
* otherwise, write intr char.
*/
static void
send_intr ()
{
ptyflush (); /* half-hearted */
#if defined(HAVE_STREAMSPTY) && defined(TIOCSIGNAL)
/* Streams PTY style ioctl to post a signal */
{
int sig = SIGINT;
ioctl (pty, TIOCSIGNAL, &sig);
ioctl (pty, I_FLUSH, FLUSHR);
}
#else
#ifdef TCSIG
ioctl (pty, TCSIG, (char *) SIGINT);
#else /* TCSIG */
init_termbuf ();
pty_output_byte (slctab[SLC_IP].sptr ?
(unsigned char) *slctab[SLC_IP].sptr : '\177');
#endif /* TCSIG */
#endif
}
void
telrcv ()
{
register int c;
static int state = TS_DATA;
while (net_input_level () > 0 & !pty_buffer_is_full () )
{
c = net_get_char (0);
#ifdef ENCRYPTION
if (decrypt_input)
c = (*decrypt_input) (c);
#endif /* ENCRYPTION */
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))
{
int nc = net_get_char (1);
#ifdef ENCRYPTION
if (decrypt_input)
nc = (*decrypt_input) (nc & 0xff);
#endif /* ENCRYPTION */
/*
* If we are operating in linemode,
* convert to local end-of-line.
*/
if (linemode
&& net_input_level () > 0
&& (('\n' == nc) || (!nc && tty_iscrnl ())))
{
net_get_char (0); /* Remove from the buffer */
c = '\n';
}
else
{
#ifdef ENCRYPTION
if (decrypt_input)
(*decrypt_input) (-1);
#endif /* ENCRYPTION */
state = TS_CR;
}
}
pty_output_byte (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:
DEBUG (debug_options, 1,
printoption ("td: recv IAC", c));
send_intr ();
break;
case BREAK:
DEBUG (debug_options, 1,
printoption ("td: recv IAC", c));
send_brk ();
break;
/*
* Are You There?
*/
case AYT:
DEBUG (debug_options, 1,
printoption ("td: recv IAC", c));
recv_ayt ();
break;
/*
* Abort Output
*/
case AO:
{
DEBUG (debug_options, 1,
printoption ("td: recv IAC", c));
ptyflush (); /* half-hearted */
init_termbuf ();
if (slctab[SLC_AO].sptr
&& *slctab[SLC_AO].sptr != (cc_t) (_POSIX_VDISABLE))
pty_output_byte (*slctab[SLC_AO].sptr);
netclear (); /* clear buffer back */
net_output_data ("%c%c", IAC, DM);
set_neturg ();
DEBUG(debug_options, 1,
printoption ("td: send IAC", DM));
break;
}
/*
* Erase Character and
* Erase Line
*/
case EC:
case EL:
{
cc_t ch;
DEBUG(debug_options, 1,
printoption ("td: recv IAC", c));
ptyflush (); /* half-hearted */
init_termbuf ();
if (c == EC)
ch = *slctab[SLC_EC].sptr;
else
ch = *slctab[SLC_EL].sptr;
if (ch != (cc_t) (_POSIX_VDISABLE))
pty_output_byte ((unsigned char)ch);
break;
}
/*
* Check for urgent data...
*/
case DM:
DEBUG(debug_options, 1,
printoption ("td: recv IAC", c));
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))
send_eof ();
break;
/*
* Handle RFC 10xx Telnet linemode option additions
* to command stream (EOF, SUSP, ABORT).
*/
case xEOF:
send_eof ();
break;
case SUSP:
send_susp ();
break;
case ABORT:
send_brk ();
break;
case IAC:
pty_output_byte (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.
*/
/* for DIAGNOSTICS */
SB_ACCUM (IAC);
SB_ACCUM (c);
subpointer -= 2;
SB_TERM ();
suboption ();
state = TS_IAC;
goto gotiac;
}
SB_ACCUM (c);
state = TS_SB;
}
else
{
/* for DIAGNOSTICS */
SB_ACCUM (IAC);
SB_ACCUM (SE);
subpointer -= 2;
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);
}
}
} /* 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.
*
*/
void
send_do (int option, int 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]++;
}
net_output_data (doopt, option);
DEBUG(debug_options, 1, printoption ("td: send do", option));
}
#ifdef AUTHENTICATION
extern void auth_request ();
#endif
extern void doclientstat ();
#ifdef ENCRYPTION
extern void encrypt_send_support ();
#endif /* ENCRYPTION */
void
willoption (int option)
{
int changeok = 0;
void (*func) () = 0;
/*
* process input from peer.
*/
DEBUG(debug_options, 1, printoption ("td: recv will", option));
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:
/*
* 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);
}
else if (lmodetype == NO_AUTOKLUDGE)
lmodetype = KLUDGE_OK;
/*
* 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_NEW_ENVIRON:
case TELOPT_OLD_ENVIRON:
changeok++;
break;
case TELOPT_LINEMODE:
/*
* Note client's desire to use linemode.
*/
lmodetype = REAL_LINEMODE;
func = doclientstat;
changeok++;
break;
#ifdef AUTHENTICATION
case TELOPT_AUTHENTICATION:
func = auth_request;
changeok++;
break;
#endif
#ifdef ENCRYPTION
case TELOPT_ENCRYPT:
func = encrypt_send_support;
changeok++;
break;
#endif /* ENCRYPTION */
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;
case TELOPT_LINEMODE:
/*
* Note client's desire to use linemode.
*/
lmodetype = REAL_LINEMODE;
func = doclientstat;
break;
#ifdef AUTHENTICATION
case TELOPT_AUTHENTICATION:
func = auth_request;
break;
#endif
#ifdef ENCRYPTION
case TELOPT_ENCRYPT:
func = encrypt_send_support;
break;
#endif /* ENCRYPTION */
case TELOPT_LFLOW:
func = flowstat;
break;
}
}
}
set_his_state_will (option);
if (func)
(*func) ();
} /* end of willoption */
void
send_dont (int option, int 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]++;
}
net_output_data (dont, option);
DEBUG(debug_options, 1, printoption ("td: send dont", option));
}
void
wontoption (int option)
{
/*
* Process client input.
*/
DEBUG(debug_options, 1, printoption ("td: recv wont", option));
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;
case TELOPT_LINEMODE:
/*
* If real linemode is supported, then client is
* asking to turn linemode off.
*/
if (lmodetype != REAL_LINEMODE)
break;
clientstat (TELOPT_LINEMODE, WONT, 0);
break;
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;
#if defined(AUTHENTICATION)
case TELOPT_AUTHENTICATION:
auth_finished (0, AUTH_REJECT);
break;
#endif
/*
* 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_OLD_ENVIRON:
settimer (oenvironsubopt);
break;
case TELOPT_NEW_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 (lmodetype < NO_AUTOKLUDGE)
{
lmodetype = NO_LINEMODE;
clientstat (TELOPT_LINEMODE, WONT, 0);
send_will (TELOPT_SGA, 1);
send_will (TELOPT_ECHO, 1);
}
break;
#if defined(AUTHENTICATION)
case TELOPT_AUTHENTICATION:
auth_finished (0, AUTH_REJECT);
break;
#endif
default:
break;
}
}
}
set_his_state_wont (option);
} /* end of wontoption */
void
send_will (int option, int 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]++;
}
net_output_data (will, option);
DEBUG(debug_options, 1,printoption ("td: send will", option));
}
void
dooption (int option)
{
int changeok = 0;
/*
* Process client input.
*/
DEBUG(debug_options, 1, printoption ("td: recv do", option));
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:
if (lmodetype == NO_LINEMODE)
{
init_termbuf ();
tty_setecho (1);
set_termbuf ();
}
changeok++;
break;
case TELOPT_BINARY:
init_termbuf ();
tty_binaryout (1);
set_termbuf ();
changeok++;
break;
case TELOPT_SGA:
/*
* 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;
}
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_LOGOUT:
/*
* When we get a LOGOUT option, respond
* with a WILL LOGOUT, make sure that
* it gets written out to the network,
* and then just go away...
*/
set_my_want_state_will (TELOPT_LOGOUT);
send_will (TELOPT_LOGOUT, 0);
set_my_state_will (TELOPT_LOGOUT);
netflush ();
cleanup (0);
/* NOT REACHED */
break;
#ifdef ENCRYPTION
case TELOPT_ENCRYPT:
changeok++;
break;
#endif /* ENCRYPTION */
case TELOPT_LINEMODE:
case TELOPT_TTYPE:
case TELOPT_NAWS:
case TELOPT_TSPEED:
case TELOPT_LFLOW:
case TELOPT_XDISPLOC:
#ifdef TELOPT_ENVIRON
case TELOPT_NEW_ENVIRON:
#endif
case TELOPT_OLD_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 */
void
send_wont (int option, int 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]++;
}
net_output_data (wont, option);
DEBUG(debug_options, 1, printoption ("td: send wont", option));
}
void
dontoption (int option)
{
/*
* Process client input.
*/
DEBUG(debug_options, 1,printoption ("td: recv dont", option));
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 */
if ((lmodetype != REAL_LINEMODE) &&
(lmodetype != KLUDGE_LINEMODE))
{
init_termbuf ();
tty_setecho (0);
set_termbuf ();
}
break;
case TELOPT_SGA:
/*
* If kludge linemode is in use, then we
* must process an incoming do SGA for
* linemode purposes.
*/
if ((lmodetype == KLUDGE_LINEMODE) ||
(lmodetype == KLUDGE_OK))
{
/*
* The client is asking us to turn
* linemode on.
*/
lmodetype = KLUDGE_LINEMODE;
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.
*/
}
break;
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 */
#ifdef ENV_HACK
int env_ovar = -1;
int env_ovalue = -1;
#else /* ENV_HACK */
#define env_ovar OLD_ENV_VAR
#define env_ovalue OLD_ENV_VALUE
#endif /* ENV_HACK */
/*
* 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
*/
void
suboption ()
{
register int subchar;
DEBUG(debug_options, 1, printsub ('<', subpointer, SB_LEN () + 2));
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 ((char *) subpointer);
while (SB_GET () != ',' && !SB_EOF ());
if (SB_EOF ())
return;
rspeed = atoi ((char *) subpointer);
clientstat (TELOPT_TSPEED, xspeed, rspeed);
break;
} /* end of case TELOPT_TSPEED */
case TELOPT_TTYPE:
{
static struct obstack stk;
char *p;
if (his_state_is_wont (TELOPT_TTYPE)) /* Ignore if option disabled */
break;
settimer (ttypesubopt);
if (SB_EOF () || SB_GET () != TELQUAL_IS)
return; /* ??? XXX but, this is the most robust */
if (terminaltype)
free (terminaltype);
obstack_init (&stk);
while (!SB_EOF ())
{
int c = tolower (SB_GET ());
obstack_1grow (&stk, c);
}
obstack_1grow (&stk, 0);
p = obstack_finish (&stk);
terminaltype = xstrdup (p);
obstack_free (&stk, NULL);
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 */
case TELOPT_LINEMODE:
{
register int request;
/* Ignore if option disabled */
if (his_state_is_wont (TELOPT_LINEMODE))
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);
break;
}
else if (request == LM_MODE)
{
if (SB_EOF ())
return;
useeditmode = SB_GET (); /* get mode flag */
clientstat (LM_MODE, 0, 0);
break;
}
if (SB_EOF ())
break;
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 */
case TELOPT_STATUS:
{
int mode;
if (SB_EOF ())
break;
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", (char *) subpointer, 1);
break;
} /* end of case TELOPT_XDISPLOC */
#ifdef TELOPT_NEW_ENVIRON
case TELOPT_NEW_ENVIRON:
#endif
case TELOPT_OLD_ENVIRON:
{
register int c;
register char *cp, *varp, *valp;
if (SB_EOF ())
return;
c = SB_GET ();
if (c == TELQUAL_IS)
{
if (subchar == TELOPT_OLD_ENVIRON)
settimer (oenvironsubopt);
else
settimer (environsubopt);
}
else if (c != TELQUAL_INFO)
return;
#ifdef TELOPT_NEW_ENVIRON
if (subchar == TELOPT_NEW_ENVIRON)
{
while (!SB_EOF ())
{
c = SB_GET ();
if ((c == NEW_ENV_VAR) || (c == ENV_USERVAR))
break;
}
}
else
#endif
{
#ifdef ENV_HACK
/*
* We only want to do this if we haven't already decided
* whether or not the other side has its VALUE and VAR
* reversed.
*/
if (env_ovar < 0)
{
register int last = -1; /* invalid value */
int empty = 0;
int got_var = 0, got_value = 0, got_uservar = 0;
/*
* The other side might have its VALUE and VAR values
* reversed. To be interoperable, we need to determine
* which way it is. If the first recognized character
* is a VAR or VALUE, then that will tell us what
* type of client it is. If the fist recognized
* character is a USERVAR, then we continue scanning
* the suboption looking for two consecutive
* VAR or VALUE fields. We should not get two
* consecutive VALUE fields, so finding two
* consecutive VALUE or VAR fields will tell us
* what the client is.
*/
SB_SAVE ();
while (!SB_EOF ())
{
c = SB_GET ();
switch (c)
{
case OLD_ENV_VAR:
if (last < 0 || last == OLD_ENV_VAR
|| (empty && (last == OLD_ENV_VALUE)))
goto env_ovar_ok;
got_var++;
last = OLD_ENV_VAR;
break;
case OLD_ENV_VALUE:
if (last < 0 || last == OLD_ENV_VALUE
|| (empty && (last == OLD_ENV_VAR)))
goto env_ovar_wrong;
got_value++;
last = OLD_ENV_VALUE;
break;
case ENV_USERVAR:
/* count strings of USERVAR as one */
if (last != ENV_USERVAR)
got_uservar++;
if (empty)
{
if (last == OLD_ENV_VALUE)
goto env_ovar_ok;
if (last == OLD_ENV_VAR)
goto env_ovar_wrong;
}
last = ENV_USERVAR;
break;
case ENV_ESC:
if (!SB_EOF ())
c = SB_GET ();
/* FALL THROUGH */
default:
empty = 0;
continue;
}
empty = 1;
}
if (empty)
{
if (last == OLD_ENV_VALUE)
goto env_ovar_ok;
if (last == OLD_ENV_VAR)
goto env_ovar_wrong;
}
/*
* Ok, the first thing was a USERVAR, and there
* are not two consecutive VAR or VALUE commands,
* and none of the VAR or VALUE commands are empty.
* If the client has sent us a well-formed option,
* then the number of VALUEs received should always
* be less than or equal to the number of VARs and
* USERVARs received.
*
* If we got exactly as many VALUEs as VARs and
* USERVARs, the client has the same definitions.
*
* If we got exactly as many VARs as VALUEs and
* USERVARS, the client has reversed definitions.
*/
if (got_uservar + got_var == got_value)
{
env_ovar_ok:
env_ovar = OLD_ENV_VAR;
env_ovalue = OLD_ENV_VALUE;
}
else if (got_uservar + got_value == got_var)
{
env_ovar_wrong:
env_ovar = OLD_ENV_VALUE;
env_ovalue = OLD_ENV_VAR;
DEBUG(debug_options, 1,
debug_output_data (
"ENVIRON VALUE and VAR are reversed!\r\n"));
}
}
SB_RESTORE ();
#endif
while (!SB_EOF ())
{
c = SB_GET ();
if ((c == env_ovar) || (c == ENV_USERVAR))
break;
}
}
if (SB_EOF ())
return;
cp = varp = (char *) subpointer;
valp = 0;
while (!SB_EOF ())
{
c = SB_GET ();
if (subchar == TELOPT_OLD_ENVIRON)
{
if (c == env_ovar)
c = NEW_ENV_VAR;
else if (c == env_ovalue)
c = NEW_ENV_VALUE;
}
switch (c)
{
case NEW_ENV_VALUE:
*cp = '\0';
cp = valp = (char *) subpointer;
break;
case NEW_ENV_VAR:
case ENV_USERVAR:
*cp = '\0';
if (valp)
(void) setenv (varp, valp, 1);
else
unsetenv (varp);
cp = varp = (char *) subpointer;
valp = 0;
break;
case ENV_ESC:
if (SB_EOF ())
break;
c = SB_GET ();
/* FALL THROUGH */
default:
*cp++ = c;
break;
}
}
*cp = '\0';
if (valp)
(void) setenv (varp, valp, 1);
else
unsetenv (varp);
break;
} /* end of case TELOPT_NEW_ENVIRON */
#if defined(AUTHENTICATION)
case TELOPT_AUTHENTICATION:
if (SB_EOF ())
break;
switch (SB_GET ())
{
case TELQUAL_SEND:
case TELQUAL_REPLY:
/*
* These are sent by us and cannot be sent by
* the client.
*/
break;
case TELQUAL_IS:
auth_is (subpointer, SB_LEN ());
break;
case TELQUAL_NAME:
auth_name (subpointer, SB_LEN ());
break;
}
break;
#endif
#ifdef ENCRYPTION
case TELOPT_ENCRYPT:
if (SB_EOF ())
break;
switch (SB_GET ())
{
case ENCRYPT_SUPPORT:
encrypt_support (subpointer, SB_LEN ());
break;
case ENCRYPT_IS:
encrypt_is (subpointer, SB_LEN ());
break;
case ENCRYPT_REPLY:
encrypt_reply (subpointer, SB_LEN ());
break;
case ENCRYPT_START:
encrypt_start (subpointer, SB_LEN ());
break;
case ENCRYPT_END:
encrypt_end ();
break;
case ENCRYPT_REQSTART:
encrypt_request_start (subpointer, SB_LEN ());
break;
case ENCRYPT_REQEND:
/*
* We can always send an REQEND so that we cannot
* get stuck encrypting. We should only get this
* if we have been able to get in the correct mode
* anyhow.
*/
encrypt_request_end ();
break;
case ENCRYPT_ENC_KEYID:
encrypt_enc_keyid (subpointer, SB_LEN ());
break;
case ENCRYPT_DEC_KEYID:
encrypt_dec_keyid (subpointer, SB_LEN ());
break;
default:
break;
}
break;
#endif /* ENCRYPTION */
default:
break;
} /* end of switch */
} /* end of suboption */
void
doclientstat ()
{
clientstat (TELOPT_LINEMODE, WILL, 0);
}
void
send_status ()
{
#define ADD(c) \
do { \
if (ep > ncp) \
*ncp++ = c; \
else \
goto trunc; \
} while (0)
#define ADD_DATA(c) \
do { \
ADD(c); if (c == SE || c == IAC) ADD(c); \
} while (0)
unsigned char statusbuf[256];
unsigned char *ep;
register unsigned char *ncp;
register unsigned char i;
ncp = statusbuf;
ep = statusbuf + sizeof (statusbuf);
netflush (); /* get rid of anything waiting to go out */
ADD (IAC);
ADD (SB);
ADD (TELOPT_STATUS);
ADD (TELQUAL_IS);
/*
* We check the want_state rather than the current state,
* because if we received a DO/WILL for an option that we
* don't support, and the other side didn't send a DONT/WONT
* in response to our WONT/DONT, then the "state" will be
* WILL/DO, and the "want_state" will be WONT/DONT. We
* need to go by the latter.
*/
for (i = 0; i < (unsigned char) NTELOPTS; i++)
{
if (my_want_state_is_will (i))
{
ADD (WILL);
ADD_DATA (i);
}
if (his_want_state_is_will (i))
{
ADD (DO);
ADD_DATA (i);
}
}
if (his_want_state_is_will (TELOPT_LFLOW))
{
ADD (SB);
ADD (TELOPT_LFLOW);
if (flowmode)
ADD (LFLOW_ON);
else
ADD (LFLOW_OFF);
ADD (SE);
if (restartany >= 0)
{
ADD (SB);
ADD (TELOPT_LFLOW);
if (restartany)
ADD (LFLOW_RESTART_ANY);
else
ADD (LFLOW_RESTART_XON);
ADD (SE);
}
}
if (his_want_state_is_will (TELOPT_LINEMODE))
{
unsigned char *cp, *cpe;
int len;
ADD (SB);
ADD (TELOPT_LINEMODE);
ADD (LM_MODE);
ADD_DATA (editmode);
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);
}
ADD (IAC);
ADD (SE);
net_output_datalen (statusbuf, ncp - statusbuf);
netflush (); /* Send it on its way */
DEBUG(debug_options, 1, printsub ('>', statusbuf, ncp - statusbuf));
return;
trunc:
/* XXX bark? */
return;
#undef ADD
#undef ADD_DATA
}