/* * 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. * 3. 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. */ #if 0 #ifndef lint static const char sccsid[] = "@(#)termstat.c 8.2 (Berkeley) 5/30/95"; #endif #endif #include <sys/cdefs.h> __FBSDID("$FreeBSD$"); #include "telnetd.h" #ifdef ENCRYPTION #include <libtelnet/encrypt.h> #endif /* * local variables */ int def_tspeed = -1, def_rspeed = -1; #ifdef TIOCSWINSZ int def_row = 0, def_col = 0; #endif #ifdef LINEMODE static int _terminit = 0; #endif /* LINEMODE */ #ifdef LINEMODE /* * 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 * NO_KLUDGE : don't initiate kludge linemode. * 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, * and the "-k" (don't initiate kludge linemode) isn't set, * 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) { int need_will_echo = 0; /* * Check for changes to flow control if client supports it. */ flowstat(); /* * 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); } if (uselinemode) { /* * Check for state of BINARY options. * * We only need to do the binary dance if we are actually going * to use linemode. As this confuses some telnet clients * that don't support linemode, and doesn't gain us * anything, we don't do it unless we're doing linemode. * -Crh (henrich@msu.edu) */ 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); } } #ifdef ENCRYPTION /* * If the terminal is not echoing, but editing is enabled, * something like password input is going to happen, so * if we the other side is not currently sending encrypted * data, ask the other side to start encrypting. */ if (his_state_is_will(TELOPT_ENCRYPT)) { static int enc_passwd = 0; if (uselinemode && !tty_isecho() && tty_isediting() && (enc_passwd == 0) && !decrypt_input) { encrypt_send_request_start(); enc_passwd = 1; } else if (enc_passwd) { encrypt_send_request_end(); enc_passwd = 0; } } #endif /* ENCRYPTION */ /* * 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; #ifdef KLUDGELINEMODE if (lmodetype == KLUDGE_OK) lmodetype = KLUDGE_LINEMODE; #endif } /* * 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 */ output_data("%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. */ output_data("%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 */ #endif /* LINEMODE */ /* * 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); } } } /* * clientstat * * Process linemode related requests from the client. * Client can request a change to only one of linemode, editmode or slc's * at a time, and if using kludge linemode, then only linemode may be * affected. */ void clientstat(int code, int parm1, int parm2) { /* * Get a copy of terminal characteristics. */ init_termbuf(); /* * Process request from client. code tells what it is. */ switch (code) { #ifdef LINEMODE case TELOPT_LINEMODE: /* * Don't do anything unless client is asking us to change * modes. */ uselinemode = (parm1 == WILL); if (uselinemode != linemode) { # ifdef KLUDGELINEMODE /* * If using kludge linemode, make sure that * we can do what the client asks. * We can not turn off linemode if alwayslinemode * and the ICANON bit is set. */ if (lmodetype == KLUDGE_LINEMODE) { if (alwayslinemode && tty_isediting()) { uselinemode = 1; } } /* * Quit now if we can't do it. */ if (uselinemode == linemode) return; /* * If using real linemode and linemode is being * turned on, send along the edit mode mask. */ if (lmodetype == REAL_LINEMODE && uselinemode) # else /* KLUDGELINEMODE */ if (uselinemode) # 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; output_data("%c%c%c%c%c%c%c", IAC, SB, TELOPT_LINEMODE, LM_MODE, useeditmode, IAC, SE); editmode = useeditmode; } tty_setlinemode(uselinemode); linemode = uselinemode; if (!linemode) send_will(TELOPT_ECHO, 1); } break; case LM_MODE: { int ack, changed; /* * Client has sent along a mode mask. If it agrees with * what we are currently doing, ignore it; if not, it could * be viewed as a request to change. Note that the server * will change to the modes in an ack if it is different from * what we currently have, but we will not ack the ack. */ useeditmode &= MODE_MASK; ack = (useeditmode & MODE_ACK); useeditmode &= ~MODE_ACK; if ((changed = (useeditmode ^ editmode))) { /* * This check is for a timing problem. If the * state of the tty has changed (due to the user * application) we need to process that info * before we write in the state contained in the * ack!!! This gets out the new MODE request, * and when the ack to that command comes back * we'll set it and be in the right mode. */ if (ack) localstat(); if (changed & MODE_EDIT) tty_setedit(useeditmode & MODE_EDIT); if (changed & MODE_TRAPSIG) tty_setsig(useeditmode & MODE_TRAPSIG); if (changed & MODE_SOFT_TAB) tty_setsofttab(useeditmode & MODE_SOFT_TAB); if (changed & MODE_LIT_ECHO) tty_setlitecho(useeditmode & MODE_LIT_ECHO); set_termbuf(); if (!ack) { output_data("%c%c%c%c%c%c%c", IAC, SB, TELOPT_LINEMODE, LM_MODE, useeditmode|MODE_ACK, IAC, SE); } editmode = useeditmode; } break; } /* end of case LM_MODE */ #endif /* LINEMODE */ case TELOPT_NAWS: #ifdef TIOCSWINSZ { struct winsize ws; def_col = parm1; def_row = parm2; #ifdef LINEMODE /* * Defer changing window size until after terminal is * initialized. */ if (terminit() == 0) return; #endif /* LINEMODE */ /* * Change window size as requested by client. */ ws.ws_col = parm1; ws.ws_row = parm2; (void) ioctl(pty, TIOCSWINSZ, (char *)&ws); } #endif /* TIOCSWINSZ */ break; case TELOPT_TSPEED: { def_tspeed = parm1; def_rspeed = parm2; #ifdef LINEMODE /* * Defer changing the terminal speed. */ if (terminit() == 0) return; #endif /* LINEMODE */ /* * Change terminal speed as requested by client. * We set the receive speed first, so that if we can't * store separate receive and transmit speeds, the transmit * speed will take precedence. */ tty_rspeed(parm2); tty_tspeed(parm1); set_termbuf(); break; } /* end of case TELOPT_TSPEED */ default: /* What? */ break; } /* end of switch */ netflush(); } /* end of clientstat */ #ifdef LINEMODE /* * defer_terminit * * Some things should not be done until after the login process has started * and all the pty modes are set to what they are supposed to be. This * function is called when the pty state has been processed for the first time. * It calls other functions that do things that were deferred in each module. */ void defer_terminit(void) { /* * local stuff that got deferred. */ if (def_tspeed != -1) { clientstat(TELOPT_TSPEED, def_tspeed, def_rspeed); def_tspeed = def_rspeed = 0; } #ifdef TIOCSWINSZ if (def_col || def_row) { struct winsize ws; memset((char *)&ws, 0, sizeof(ws)); ws.ws_col = def_col; ws.ws_row = def_row; (void) ioctl(pty, TIOCSWINSZ, (char *)&ws); } #endif /* * The only other module that currently defers anything. */ deferslc(); } /* end of defer_terminit */ /* * terminit * * Returns true if the pty state has been processed yet. */ int terminit(void) { return(_terminit); } /* end of terminit */ #endif /* LINEMODE */
