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ckctel.c
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ckctel.c
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char *cktelv = "Telnet support, 10.0.281, 23 Sep 2022";
#define CKCTEL_C
int sstelnet = 0; /* Do server-side Telnet negotiation */
/* C K C T E L -- Telnet support */
/*
Authors:
Telnet protocol by Frank da Cruz and Jeffrey Altman.
Telnet Forward X by Jeffrey Altman
Telnet START_TLS support by Jeffrey Altman
Telnet AUTH and ENCRYPT support by Jeffrey Altman
Telnet COMPORT support by Jeffrey Altman
Telnet NEW-ENVIRONMENT support by Jeffrey Altman
Telnet NAWS support by Frank da Cruz and Jeffrey Altman
Telnet TERMTYPE support by Jeffrey Altman
Telnet KERMIT support by Jeffrey Altman
Other contributions as indicated in the code.
Copyright (C) 1985, 2021,
Trustees of Columbia University in the City of New York.
All rights reserved. See the C-Kermit COPYING.TXT file or the
copyright text in the ckcmai.c module for disclaimer and permissions.
Latest update: 27 Jan 2022
*/
/*
NOTE TO CONTRIBUTORS: This file, and all the other shared (ckc and cku)
C-Kermit source files, must be compatible with C preprocessors that support
only #ifdef, #else, #endif, #define, and #undef. Please do not use #if,
logical operators, or other preprocessor features in this module. Also,
don't use any ANSI C constructs except within #ifdef CK_ANSIC..#endif.
*/
#ifndef NONET
#ifndef NOTCPIP
#include "ckcsym.h"
#include "ckcdeb.h"
#ifdef TIMEH
#include <time.h> /* fdc 2012-12-17 */
#else
#ifdef SYSTIMH
#include <sys/time.h>
#endif /* SYSTIMH */
#endif /* TIMEH */
#ifdef TNCODE
#include "ckcker.h"
#define TELCMDS /* to define name array */
#define TELOPTS /* to define name array */
#define SLC_NAMES /* to define name array */
#define ENCRYPT_NAMES
#define AUTH_NAMES
#define TELOPT_STATES
#define TELOPT_MODES
#define TNC_NAMES
#include "ckcnet.h"
#include "ckctel.h"
#ifdef CK_AUTHENTICATION
#include "ckuath.h"
#endif /* CK_AUTHENTICATION */
#ifdef CK_SSL
#include "ck_ssl.h"
#endif /* CK_SSL */
#ifndef NOTERM
#ifdef OS2 /* For terminal type name string */
#include "ckuusr.h"
#ifndef NT
#define INCL_DOSSEMAPHORES
#include <os2.h>
#undef COMMENT
#else
#ifndef __WATCOMC__
#define isascii __isascii
#endif /* __WATCOMC__ */
#endif /* NT */
#include "ckocon.h"
extern int tt_type, max_tt;
extern struct tt_info_rec tt_info[];
#endif /* OS2 */
#endif /* NOTERM */
#ifdef OS2
#include <assert.h>
#ifdef NT
#include <setjmpex.h>
#else /* NT */
#include <setjmp.h>
#endif /* NT */
#include <signal.h>
#include "ckcsig.h"
#include "ckosyn.h"
#endif /* OS2 */
#ifdef CK_NAWS /* Negotiate About Window Size */
#ifdef RLOGCODE
_PROTOTYP( int rlog_naws, (void) );
#endif /* RLOGCODE */
#endif /* CK_NAWS */
int tn_init = 0; /* Telnet protocol initialized flag */
int tn_begun = 0; /* Telnet protocol started flag */
static int tn_first = 1; /* First time init flag */
extern int tn_exit; /* Exit on disconnect */
extern int nettype;
extern int inserver; /* Running as IKSD */
char *tn_term = NULL; /* Terminal type override */
#ifdef CK_SNDLOC
char *tn_loc = NULL; /* Location override */
#endif /* CK_SNDLOC */
int tn_nlm = TNL_CRLF; /* Telnet CR -> CR LF mode */
int tn_b_nlm = TNL_CR; /* Telnet Binary CR RAW mode */
int tn_b_meu = 0; /* Telnet Binary ME means U too */
int tn_b_ume = 0; /* Telnet Binary U means ME too */
int tn_wait_flg = 1; /* Telnet Wait for Negotiations */
int tn_infinite = 0; /* Telnet Bug Infinite-Loop-Check */
int tn_rem_echo = 1; /* We will echo if WILL ECHO */
int tn_b_xfer = 0; /* Telnet Binary for Xfers? */
int tn_sb_bug = 1; /* Telnet BUG - SB w/o WILL or DO */
int tn_auth_krb5_des_bug = 1; /* Telnet BUG - AUTH KRB5 DES */
/* truncates long keys */
int tn_no_encrypt_xfer = 0; /* Turn off Telnet Encrypt? */
int tn_delay_sb = 1; /* Delay SBs until safe */
int tn_auth_how = TN_AUTH_HOW_ANY;
int tn_auth_enc = TN_AUTH_ENC_ANY;
int tn_deb = 0; /* Telnet Debug mode */
int tn_sfu = 0; /* Microsoft SFU compatibility */
#ifdef CK_FORWARD_X
char * tn_fwdx_xauthority = NULL; /* Xauthority File */
int fwdx_no_encrypt = 0; /* Forward-X requires encryption */
#endif /* CK_FORWARD_X */
#ifdef OS2
int ttnum = -1; /* Last Telnet Terminal Type sent */
int ttnumend = 0; /* Has end of list been found */
#endif /* OS2 */
char tn_msg[TN_MSG_LEN]; /* Telnet data can be rather long */
char hexbuf[TN_MSG_LEN];
char tn_msg_out[TN_MSG_LEN];
#ifdef CK_FORWARD_X
CHAR fwdx_msg_out[TN_MSG_LEN];
#endif /* CK_FORWARD_X */
/*
In order to prevent an infinite telnet negotiation loop we maintain a
count of the number of times the same telnet negotiation message is
sent. When this count hits MAXTNCNT, we do not send any more of the
message. The count is stored in the tncnts[][] array.
The tncnts[][] array is indexed by negotiation option (SUPPRESS GO AHEAD,
TERMINAL TYPE, NAWS, etc. - see the tnopts[] array) and the four
negotiation message types (WILL, WONT, DO, DONT). All telnet negotiations
are kept track of in this way.
The count for a message is zeroed when the "opposite" message is sent.
WILL is the opposite of WONT, and DO is the opposite of DONT.
For example sending "WILL SGA" increments tncnts[TELOPT_SGA][0]
and zeroes tncnts[TELOPT_SGA][1].
The code that does this is in tn_sopt().
[email protected], 18/3/1995
8/16/1998 - with the recent rewrite of the telnet state machine I don't
think this code is necessary anymore. However, it can't do any harm so
I am leaving it in. - Jeff
12/28/1998 - all references to tncnts[] must be done with TELOPT_INDEX(opt)
because the Telnet option list is no longer contiguous. We also must
allocate NTELOPTS + 1 because the TELOPT_INDEX() macro returns NTELOPTS
for an invalid option number.
*/
#define MAXTNCNT 4 /* Permits 4 intermediate telnet firewalls/gateways */
char tncnts[NTELOPTS+1][4]; /* Counts */
char tnopps[4] = { 1,0,3,2 }; /* Opposites */
#ifdef CK_ENVIRONMENT
#ifdef CK_FORWARD_X
#define TSBUFSIZ 2056
#else /* CK_FORWARD_X */
#define TSBUFSIZ 1024
#endif /* CK_FORWARD_X */
char tn_env_acct[64];
char tn_env_disp[64];
char tn_env_job[64];
char tn_env_prnt[64];
char tn_env_sys[64];
char * tn_env_uservar[8][2];
int tn_env_flg = 1;
#else /* CK_ENVIRONMENT */
#define TSBUFSIZ 41
int tn_env_flg = 0;
#endif /* CK_ENVIRONMENT */
#ifdef COMMENT
/* SIGWINCH handler moved to ckuusx.c */
#ifndef NOSIGWINCH
#ifdef CK_NAWS /* Window size business */
#ifdef UNIX
#include <signal.h>
#endif /* UNIX */
#endif /* CK_NAWS */
#endif /* NOSIGWINCH */
#endif /* COMMENT */
CHAR sb[TSBUFSIZ]; /* Buffer - incoming subnegotiations */
CHAR sb_out[TSBUFSIZ]; /* Buffer - outgoing subnegotiations */
int tn_duplex = 1; /* Local echo */
extern char uidbuf[]; /* User ID buffer */
extern int quiet, ttnet, ttnproto, debses, what, duplex, oldplex, local;
extern int seslog, sessft, whyclosed;
#ifdef OS2
#ifndef NOTERM
extern int tt_rows[], tt_cols[];
extern int tt_status[VNUM];
extern int scrninitialized[];
#endif /* NOTERM */
#else /* OS2 */
extern int tt_rows, tt_cols; /* Everybody has this */
#endif /* OS2 */
extern int cmd_cols, cmd_rows;
extern char namecopy[];
extern char myipaddr[]; /* Global copy of my IP address */
#ifndef TELOPT_MACRO
int
telopt_index(opt) int opt; {
if (opt >= 0 && opt <= TELOPT_STDERR)
return(opt);
else if (opt >= TELOPT_PRAGMA_LOGON && opt <= TELOPT_PRAGMA_HEARTBEAT)
return(opt-88);
else if (opt == TELOPT_IBM_SAK)
return(opt-147);
else
return(NTELOPTS);
}
int
telopt_ok(opt) int opt; {
return((opt >= TELOPT_BINARY && opt <= TELOPT_STDERR) ||
(opt >= TELOPT_PRAGMA_LOGON && opt <= TELOPT_PRAGMA_HEARTBEAT) ||
(opt == TELOPT_IBM_SAK));
}
CHAR *
telopt(opt) int opt; {
if (telopt_ok(opt))
return((CHAR *)telopts[telopt_index(opt)]);
else
return((CHAR *)"UNKNOWN");
}
int
telopt_mode_ok(opt) int opt; {
return((unsigned int)(opt) <= TN_NG_MU);
}
CHAR *
telopt_mode(opt) int opt; {
if (telopt_mode_ok(opt))
return((CHAR *)telopt_modes[opt-TN_NG_RF]);
else
return((CHAR *)"UNKNOWN");
}
#endif /* TELOPT_MACRO */
static int
tn_outst(notquiet) int notquiet; {
int outstanding = 0;
int x = 0;
#ifdef CK_ENCRYPTION
int e = 0;
int d = 0;
#endif /* CK_ENCRYPTION */
if (tn_wait_flg) {
for (x = TELOPT_FIRST; x <= TELOPT_LAST; x++) {
if (TELOPT_OK(x)) {
if (TELOPT_UNANSWERED_WILL(x)) {
if ( notquiet )
printf("?Telnet waiting for response to WILL %s\r\n",
TELOPT(x));
debug(F111,"tn_outst","unanswered WILL",x);
outstanding = 1;
if ( !notquiet )
break;
}
if (TELOPT_UNANSWERED_DO(x)) {
if ( notquiet )
printf("?Telnet waiting for response to DO %s\r\n",
TELOPT(x));
debug(F111,"tn_outst","unanswered DO",x);
outstanding = 1;
if ( !notquiet )
break;
}
if (TELOPT_UNANSWERED_WONT(x)) {
if ( notquiet )
printf("?Telnet waiting for response to WONT %s\r\n",
TELOPT(x));
debug(F111,"tn_outst","unanswered WONT",x);
outstanding = 1;
if ( !notquiet )
break;
}
if (TELOPT_UNANSWERED_DONT(x)) {
if ( notquiet )
printf("?Telnet waiting for response to DONT %s\r\n",
TELOPT(x));
debug(F111,"tn_outst","unanswered DONT",x);
outstanding = 1;
if ( !notquiet )
break;
}
if (TELOPT_UNANSWERED_SB(x)) {
if ( notquiet )
printf("?Telnet waiting for response to SB %s\r\n",
TELOPT(x));
debug(F111,"tn_outst","unanswered SB",x);
outstanding = 1;
if ( !notquiet )
break;
}
}
}
#ifdef CK_AUTHENTICATION
if (ck_tn_auth_in_progress()) {
if (TELOPT_ME(TELOPT_AUTHENTICATION)) {
if (notquiet)
printf("?Telnet waiting for WILL %s subnegotiation\r\n",
TELOPT(TELOPT_AUTHENTICATION));
debug(F111,
"tn_outst",
"ME authentication in progress",
TELOPT_AUTHENTICATION
);
outstanding = 1;
} else if (TELOPT_U(TELOPT_AUTHENTICATION)) {
if (notquiet)
printf("?Telnet waiting for DO %s subnegotiation\r\n",
TELOPT(TELOPT_AUTHENTICATION));
debug(F111,
"tn_outst",
"U authentication in progress",
TELOPT_AUTHENTICATION
);
outstanding = 1;
}
}
#endif /* CK_AUTHENTICATION */
#ifdef CK_ENCRYPTION
if (!outstanding) {
e = ck_tn_encrypting();
d = ck_tn_decrypting();
if (TELOPT_ME(TELOPT_ENCRYPTION)) {
if (TELOPT_SB(TELOPT_ENCRYPTION).encrypt.stop && e ||
!TELOPT_SB(TELOPT_ENCRYPTION).encrypt.stop && !e
) {
if ( notquiet )
printf("?Telnet waiting for WILL %s subnegotiation\r\n",
TELOPT(TELOPT_ENCRYPTION));
debug(F111,
"tn_outst",
"encryption mode switch",
TELOPT_ENCRYPTION
);
outstanding = 1;
}
}
if (TELOPT_U(TELOPT_ENCRYPTION)) {
if (TELOPT_SB(TELOPT_ENCRYPTION).encrypt.stop && d ||
!TELOPT_SB(TELOPT_ENCRYPTION).encrypt.stop && !d
) {
if ( notquiet )
printf("?Telnet waiting for DO %s subnegotiation\r\n",
TELOPT(TELOPT_ENCRYPTION));
debug(F111,
"tn_outst",
"decryption mode switch",
TELOPT_ENCRYPTION
);
outstanding = 1;
}
}
}
#endif /* CK_ENCRYPTION */
} /* if (tn_wait_flg) */
#ifdef IKS_OPTION
/* Even if we are not waiting for Telnet options we must wait for */
/* Kermit Telnet Subnegotiations if we have sent a request to the */
/* other guy. Otherwise we will get out of sync. */
if (!outstanding) {
if (TELOPT_U(TELOPT_KERMIT) &&
(TELOPT_SB(TELOPT_KERMIT).kermit.me_req_start ||
TELOPT_SB(TELOPT_KERMIT).kermit.me_req_stop ||
!TELOPT_SB(TELOPT_KERMIT).kermit.sop)
) {
if ( notquiet )
printf("?Telnet waiting for SB %s negotiation\r\n",
TELOPT(TELOPT_KERMIT));
debug(F111,"tn_outst","U kermit in progress",TELOPT_KERMIT);
outstanding = 1;
}
}
#endif /* IKS_OPTION */
#ifdef TN_COMPORT
if (!outstanding) {
if (TELOPT_ME(TELOPT_COMPORT)) {
if (TELOPT_SB(TELOPT_COMPORT).comport.wait_for_sb) {
if (notquiet)
printf("?Telnet waiting for SB %s negotiation\r\n",
TELOPT(TELOPT_COMPORT));
debug(F111,"tn_outst","ComPort SB in progress",TELOPT_COMPORT);
outstanding = 1;
}
if (TELOPT_SB(TELOPT_COMPORT).comport.wait_for_ms) {
if (notquiet)
printf("?Telnet waiting for SB %s MODEM_STATUS negotiation\r\n",
TELOPT(TELOPT_COMPORT));
debug(F111,"tn_outst","ComPort SB MS in progress",TELOPT_COMPORT);
outstanding = 1;
}
}
}
#endif /* TN_COMPORT */
return(outstanding);
}
int
istncomport() {
#ifdef TN_COMPORT
if (!local) return(0);
if (ttnet != NET_TCPB) return(0);
if (ttnproto != NP_TELNET) return(0);
if (TELOPT_ME(TELOPT_COMPORT))
return(1);
else
#endif /* TN_COMPORT */
return(0);
}
/* tn_wait() -- Wait for response to Telnet negotiation. */
/*
Wait for up to <timeout> seconds for the response to arrive.
Place all non-telnet data into Telnet Wait Buffer.
If response does arrive return 1, else return 0.
*/
#ifndef TN_WAIT_BUF_SZ
#define TN_WAIT_BUF_SZ 4096
#endif /* TN_WAIT_BUF_SZ */
static char tn_wait_buf[TN_WAIT_BUF_SZ];
static int tn_wait_idx = 0;
#ifndef TN_TIMEOUT
#define TN_TIMEOUT 120
#endif /* TN_TIMEOUT */
static int tn_wait_tmo = TN_TIMEOUT;
#ifdef CKSPINNER
VOID
prtwait(state) int state; {
switch (state % 4) {
case 0:
printf("/");
break;
case 1:
printf("-");
break;
case 2:
printf("\\");
break;
case 3:
printf("|");
break;
}
}
#endif /* CKSPINNER */
static int nflag = 0;
int
#ifdef CK_ANSIC
tn_wait(char * where)
#else
tn_wait(where) char * where;
#endif /* CK_ANSIC */
/* tn_wait */ {
extern int ckxech, local;
int ch = 0, count = 0;
#ifndef NOHINTS
int nohintgiven = 1;
extern int hints;
#endif /* NOHINTS */
int outstanding;
#ifdef TN_COMPORT
int savcarr;
extern int ttcarr;
#endif /* TN_COMPORT */
/* if (!IS_TELNET()) return(1); */
rtimer();
debug(F110,"tn_wait waiting for",where,0);
tn_wait_tmo = TN_TIMEOUT;
debug(F111,"tn_wait","timeout",tn_wait_tmo);
outstanding = tn_outst(0);
debug(F111,"tn_wait","outstanding",outstanding);
debug(F111,"tn_wait","tn_wait_flg",tn_wait_flg);
/* The following is meant to be !(||). We only want to return */
/* immediately if both the tn_wait_flg && tn_outst() are false */
if (!(outstanding || tn_wait_flg)) /* If no need to wait */
return(1); /* Don't. */
if (tn_deb || debses) tn_debug("<wait for outstanding negotiations>");
#ifdef CKSPINNER
if (!sstelnet && !quiet)
prtwait(0);
#endif /* CKSPINNER */
/* Wait up to TN_TIMEOUT sec for responses to outstanding telnet negs */
do {
#ifdef NTSIG
ck_ih();
#endif /* NTSIG */
ch = ttinc(1);
if (ch == -1) { /* Timed out */
if (!sstelnet && !quiet) { /* Let user know... */
#ifdef CKSPINNER
printf("\b");
prtwait(gtimer());
#else
if (nflag == 0) {
printf(" Negotiations.");
nflag++;
}
if (nflag > 0) {
printf(".");
nflag++;
fflush(stdout);
}
#endif /* CKSPINNER */
}
} else if (ch < -1) {
printf("\r\n?Connection closed by peer.\r\n");
if (tn_deb || debses) tn_debug("<connection closed by peer>");
return(-1);
} else
switch (ch) {
case IAC:
#ifdef CKSPINNER
if (!sstelnet && !quiet)
printf("\b");
#endif /* CKSPINNER */
ch = tn_doop((CHAR)(ch & 0xff),inserver?ckxech:duplex,ttinc);
#ifdef CKSPINNER
if (!sstelnet && !quiet) {
prtwait(gtimer());
}
#endif /* CKSPINNER */
debug(F101,"tn_wait tn_doop","",ch);
switch (ch) {
case 1:
duplex = 1; /* Turn on echoing */
if (inserver)
ckxech = 1;
break;
case 2:
duplex = 0; /* Turn off echoing */
if (inserver)
ckxech = 0;
break;
case 3:
tn_wait_buf[tn_wait_idx++] = IAC;
break;
case 4: /* IKS event */
case 6: /* Logout */
break;
case -1:
if (!quiet)
printf("?Telnet Option negotiation error.\n");
if (tn_deb || debses)
tn_debug("<Telnet Option negotiation error>");
return(-1);
case -2:
printf("?Connection closed by peer.\n");
if (tn_deb || debses) tn_debug("<Connection closed by peer>");
ttclos(0);
return(-2);
default:
if (ch < 0) {
if (tn_deb || debses) tn_debug("<Unknown connection error>");
return(ch);
}
} /* switch */
break;
default:
#ifdef CKSPINNER
if (!sstelnet && !quiet) {
printf("\b");
prtwait(gtimer());
}
#endif /* CKSPINNER */
tn_wait_buf[tn_wait_idx++] = (CHAR)(ch & 0xff);
} /* switch */
outstanding = tn_outst(0);
if ( outstanding && ch != IAC ) {
int timer = gtimer();
if ( timer > tn_wait_tmo ) {
if (!sstelnet) {
printf(
"\r\n?Telnet Protocol Timeout - connection closed\r\n");
if (tn_deb || debses)
tn_debug(
"<telnet protocol timeout - connection closed>");
tn_outst(1);
}
/* if we do not close the connection, then we will block */
/* the next time we hit a wait. and if we don't we will */
/* do the wrong thing if the host sends 0xFF and does */
/* not intend it to be an IAC. */
ttclos(0);
whyclosed = WC_TELOPT;
return(-1);
}
#ifndef NOHINTS
else if ( hints && timer > 30 && nohintgiven && !inserver ) {
#ifdef CKSPINNER
printf("\b");
#else /* CKSPINNER */
printf("\r\n");
#endif /* CKSPINNER */
printf("*************************\r\n");
printf("The Telnet %s is not sending required responses.\r\n\r\n",
sstelnet?"client":"server");
tn_outst(1);
printf("\nYou can continue to wait or you can cancel with Ctrl-C.\r\n");
printf("In case the Telnet server never responds as required,\r\n");
printf("you can try connecting to this host with TELNET /NOWAIT.\r\n");
printf("Use SET HINTS OFF to suppress further hints.\r\n");
printf("*************************\r\n");
nohintgiven = 0;
}
#endif /* NOHINTS */
}
#ifdef TN_COMPORT
/* Must disable carrier detect check if we are using Telnet Comport */
savcarr = ttcarr;
ttscarr(CAR_OFF);
count = ttchk();
ttscarr(savcarr);
#else /* TN_COMPORT */
count = ttchk();
#endif /* TN_COMPORT */
} while ((tn_wait_idx < TN_WAIT_BUF_SZ) &&
(outstanding && count >= 0));
if (tn_wait_idx == TN_WAIT_BUF_SZ) {
if (tn_deb || debses) tn_debug("<Telnet Wait Buffer filled>");
return(0);
}
if (!sstelnet && !quiet) {
#ifdef CKSPINNER
printf("\b \b");
#else
if (nflag > 0) {
printf(" (OK)\n");
nflag = -1;
}
#endif /* CKSPINNER */
}
if (tn_deb || debses) tn_debug("<no outstanding negotiations>");
return(0);
}
/* Push data from the Telnet Wait Buffer into the I/O Queue */
/* Return 1 on success */
int
tn_push() {
#ifdef NETLEBUF
extern int tt_push_inited;
#endif /* NETLEBUF */
/* if (!IS_TELNET()) return(1); */
if (tn_wait_idx) {
ckhexdump((CHAR *)"tn_push",tn_wait_buf,tn_wait_idx);
#ifdef NETLEBUF
if (!tt_push_inited) /* Local handling */
le_init();
le_puts((CHAR *)tn_wait_buf,tn_wait_idx);
#else /* External handling... */
#ifdef OS2 /* K95 has its own way */
le_puts((CHAR *)tn_wait_buf,tn_wait_idx);
#else
#ifdef TTLEBUF /* UNIX, etc */
le_puts((CHAR *)tn_wait_buf,tn_wait_idx);
#else
/*
If you see this message in AOS/VS, OS-9, VOS, etc, you need to copy
the #ifdef TTLEBUF..#endif code from ckutio.c to the corresponding
places in your ck?tio.c module.
*/
printf("tn_push called but not implemented - data lost.\n");
#endif /* TTLEBUF */
#endif /* OS2 */
#endif /* NETLEBUF */
tn_wait_idx = 0;
}
tn_wait_tmo = TN_TIMEOUT; /* Reset wait timer stats */
return(1);
}
/* T N _ S O P T */
/*
Sends a telnet option, avoids loops.
Returns 1 if command was sent, 0 if not, -1 on error.
*/
int
tn_sopt(cmd,opt) int cmd, opt; { /* TELNET SEND OPTION */
CHAR buf[5];
char msg[128];
int rc;
if (ttnet != NET_TCPB) return(-1); /* Must be TCP/IP */
if (ttnproto != NP_TELNET) return(-1); /* Must be telnet protocol */
if (!TELCMD_OK(cmd)) return(-1);
if (TELOPT_OK(opt)) {
if (cmd == DO && TELOPT_UNANSWERED_DO(opt)) return(0);
if (cmd == WILL && TELOPT_UNANSWERED_WILL(opt)) return(0);
if (cmd == DONT && TELOPT_UNANSWERED_DONT(opt)) return(0);
if (cmd == WONT && TELOPT_UNANSWERED_WONT(opt)) return(0);
}
#ifdef CK_SSL
if (TELOPT_SB(TELOPT_START_TLS).start_tls.me_follows) {
return(0);
}
#endif /* CK_SSL */
if (cmd == DO && opt == TELOPT_AUTHENTICATION)
buf[0] = 0;
if (tn_infinite && TELOPT_OK(opt)) { /* See comment above about */
int index = TELOPT_INDEX(opt); /* preventing infinite loops */
int m = cmd - WILL;
if (tncnts[index][m] > MAXTNCNT) {
#ifdef DEBUG
if (tn_deb || debses || deblog) {
ckmakmsg(msg,sizeof(msg),
"TELNET negotiation loop ",
TELCMD(cmd), " ",
TELOPT(opt));
debug(F101,msg,"",opt);
if (tn_deb || debses) tn_debug(msg);
}
#endif /* DEBUG */
return(0);
}
tncnts[index][m]++;
tncnts[index][tnopps[m]] = 0;
}
buf[0] = (CHAR) IAC;
buf[1] = (CHAR) (cmd & 0xff);
buf[2] = (CHAR) (opt & 0xff);
buf[3] = (CHAR) 0;
#ifdef DEBUG
if ((tn_deb || debses || deblog) && cmd != SB)
ckmakmsg(msg,sizeof(msg),"TELNET SENT ",TELCMD(cmd)," ",
TELOPT(opt));
#endif /* DEBUG */
#ifdef OS2
RequestTelnetMutex( SEM_INDEFINITE_WAIT );
#endif
debug(F101,msg,"",opt);
if ((tn_deb || debses) && cmd != SB)
tn_debug(msg);
rc = (ttol(buf,3) < 3);
#ifdef OS2
ReleaseTelnetMutex();
#endif
if (rc)
return(-1);
if (TELOPT_OK(opt)) {
if (cmd == DONT && TELOPT_UNANSWERED_DO(opt))
TELOPT_UNANSWERED_DO(opt) = 0;
if (cmd == WONT && TELOPT_UNANSWERED_WILL(opt))
TELOPT_UNANSWERED_WILL(opt) = 0;
if (cmd == DO && TELOPT_UNANSWERED_DONT(opt))
TELOPT_UNANSWERED_DONT(opt) = 0;
if (cmd == WILL && TELOPT_UNANSWERED_WONT(opt))
TELOPT_UNANSWERED_WONT(opt) = 0;
}
return(1);
}
/* Send a telnet sub-option */
/* Returns 1 if command was sent, 0 if not, -1 on error */
int
tn_ssbopt(opt,sub,data,len) int opt, sub; CHAR * data; int len; {
CHAR buf[256];
int n,m,rc;
if (ttnet != NET_TCPB) return(0); /* Must be TCP/IP */
if (ttnproto != NP_TELNET) return(0); /* Must be telnet protocol */
if (!TELOPT_OK(opt)) return(-1);
if (len < 0 || len > 250) {
debug(F111,"Unable to Send TELNET SB - data too long","len",len);
return(-1); /* Data too long */
}
#ifdef CK_SSL
if (TELOPT_SB(TELOPT_START_TLS).start_tls.me_follows) {
if (ttchk() < 0)
return(-1);
else
return(1);
}
#endif /* CK_SSL */
if (!data) len = 0;
buf[0] = (CHAR) IAC;
buf[1] = (CHAR) (SB & 0xff);
buf[2] = (CHAR) (opt & 0xff);
buf[3] = (CHAR) (sub & 0xff);
if (data && len > 0) {
memcpy(&buf[4],data,len);
}
buf[4+len] = (CHAR) IAC;
buf[5+len] = (CHAR) SE;
#ifdef DEBUG
if (tn_deb || debses || deblog) {
if (opt == TELOPT_START_TLS && sub == 1)
ckmakmsg(tn_msg_out,TN_MSG_LEN,"TELNET SENT SB ",
TELOPT(opt)," FOLLOWS IAC SE",NULL);
else if (opt == TELOPT_TTYPE && sub == 1)
ckmakmsg(tn_msg_out,TN_MSG_LEN,"TELNET SENT SB ", TELOPT(opt),
" SEND IAC SE",NULL);
else if (opt == TELOPT_TTYPE && sub == 0)
ckmakxmsg(tn_msg_out,TN_MSG_LEN,"TELNET SENT SB ",TELOPT(opt)," IS ",
(char *)data," IAC SE",NULL,NULL,NULL,NULL,NULL,NULL,NULL);
else if (opt == TELOPT_NEWENVIRON) {
int i, quote;
ckmakmsg(tn_msg_out,TN_MSG_LEN,"TELNET SENT SB ",
TELOPT(TELOPT_NEWENVIRON)," ",
sub == TELQUAL_SEND ? "SEND" :
sub == TELQUAL_IS ? "IS" :
sub == TELQUAL_INFO ?"INFO" : "UNKNOWN" );
for (i = 0, quote = 0; i < len; i++) {
if (quote) {
sprintf(hexbuf,"%02x",data[i]); /* safe but ugly */
ckstrncat(tn_msg_out,hexbuf,TN_MSG_LEN);
quote = 0;
} else {
switch (data[i]) {
case TEL_ENV_USERVAR:
ckstrncat(tn_msg_out," USERVAR ",TN_MSG_LEN);
break;
case TEL_ENV_VAR:
ckstrncat(tn_msg_out," VAR ",TN_MSG_LEN);
break;
case TEL_ENV_VALUE:
ckstrncat(tn_msg_out," VALUE ",TN_MSG_LEN);
break;
case TEL_ENV_ESC:
ckstrncat(tn_msg_out," ESC ",TN_MSG_LEN);
quote = 1;
break;
case IAC:
ckstrncat(tn_msg_out," IAC ",TN_MSG_LEN);
break;
default:
sprintf(hexbuf,"%c",data[i]); /* safe but ugly */
ckstrncat(tn_msg_out,hexbuf,TN_MSG_LEN);
}
}
}
ckstrncat(tn_msg_out," IAC SE",TN_MSG_LEN);
} else {
sprintf(hexbuf,"%02x",sub); /* safe but ugly */
ckmakxmsg(tn_msg_out,TN_MSG_LEN,
"TELNET SENT SB ",TELOPT(opt),
" ",
hexbuf,
" <data> IAC SE",
NULL,NULL,NULL,NULL,NULL,NULL,NULL
);
}
}
#endif /* DEBUG */
#ifdef OS2
RequestTelnetMutex( SEM_INDEFINITE_WAIT );
#endif /* OS2 */
#ifdef DEBUG
debug(F101,tn_msg_out,"",opt);
if (tn_deb || debses)
tn_debug(tn_msg_out);
#endif /* DEBUG */
rc = (ttol(buf,6+len) < 6+len);
#ifdef OS2
ReleaseTelnetMutex();
#endif
if (rc)
return(-1);
return(1);
}
/*
tn_flui() -- Processes all waiting data for Telnet commands.
All non-Telnet data is to be stored into the Telnet Wait Buffer.
Returns 1 on success.
*/
int
tn_flui() {
extern int ckxech;
int x = 0;
/* if (!IS_TELNET()) return(0); */
/* Wait up to 5 sec for responses to outstanding telnet negotiations */
while (x >= 0 && ttchk() > 0 && tn_wait_idx < TN_WAIT_BUF_SZ) {
x = ttinc(1);
switch (x) {
case IAC:
x = tn_doop((CHAR)(x & 0xff),inserver?ckxech:duplex,ttinc);
debug(F101,"tn_flui tn_doop","",x);
switch (x) {
case 1: /* Turn on echoing */
duplex = 1;
if (inserver)
ckxech = 1;
break;
case 2: /* Turn off echoing */
duplex = 0;
if (inserver)
ckxech = 0;
break;
case 3:
tn_wait_buf[tn_wait_idx++] = IAC;
break;
case 4: /* IKS event */
case 6: /* Logout */
break;
}
break;
default:
if (x >= 0)
tn_wait_buf[tn_wait_idx++] = x;
}
}
return(1);
}
unsigned char *
tn_get_display()
{
char * disp = NULL;
static char tmploc[256];
/* Must compute the DISPLAY string we are going to send to the host */
/* If one is not assigned, do not send a string unless the user has */
/* explicitedly requested we try to send one via X-Display Location */
/* But do not send a string at all if FORWARD_X is in use. */
/* if (!IS_TELNET()) return(0); */
debug(F110,"tn_get_display() myipaddr",myipaddr,0);
#ifdef CK_ENVIRONMENT
debug(F110,"tn_get_display() tn_env_disp",tn_env_disp,0);
if (tn_env_disp[0]) {
int colon = ckindex(":",tn_env_disp,0,0,1);
if ( !colon ) {
ckmakmsg(tmploc,256,myipaddr,":",tn_env_disp,NULL);
disp = tmploc;
} else if ( ckindex("localhost:",tn_env_disp,0,0,0) ||
ckindex("unix:",tn_env_disp,0,0,0) ||
ckindex("127.0.0.1:",tn_env_disp,0,0,0) ||
!ckstrcmp("0:",tn_env_disp,2,1) ||
tn_env_disp[0] == ':' ) {
ckmakmsg(tmploc,256,myipaddr,":",&tn_env_disp[colon],NULL);