391 lines
8.9 KiB
C
391 lines
8.9 KiB
C
/*****************************************************************************
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*
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* $Id$
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* Purpose ...............: Fidonet telnet proxy
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*
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*****************************************************************************
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* Copyright (C) 1997-2003
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*
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* Michiel Broek FIDO: 2:280/2802
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* Beekmansbos 10
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* 1971 BV IJmuiden
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* the Netherlands
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*
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* This file is part of MBSE BBS.
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*
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* This BBS is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2, or (at your option) any
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* later version.
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*
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* MBSE BBS is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with MBSE BBS; see the file COPYING. If not, write to the Free
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* Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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*****************************************************************************/
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/*
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Simple proxy daemon for ifcico to work with SIO/VMODEM.
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========================================================
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Written by: Vadim Zaliva, lord@crocodile.kiev.ua, 2:463/80
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This software is provided ``as is'' without express or implied warranty.
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Feel free to distribute it.
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Feel free to contact me with improovments request
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and bug reports.
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Some parts of this code are taken from
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1. serge terekhov, 2:5000/13@fidonet path for ifmail
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2. Vadim Kurland, vadim@gu.kiev.ua transl daemon.
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Thanks them.
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*/
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#include "../config.h"
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#include "../lib/libs.h"
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#include "../lib/structs.h"
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#include "../lib/users.h"
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#include "../lib/records.h"
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#include "../lib/common.h"
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#include "../lib/clcomm.h"
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#include "../lib/dbcfg.h"
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#include "../lib/mberrors.h"
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#include "mbtelnetd.h"
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#define MBT_BUFSIZ 8192
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#define MBT_TIMEOUT 3600
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void die(int);
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int init_telnet(void);
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void answer(int, int);
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int read0(char *, int);
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int write1(char *, int);
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void com_gw(int);
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#define WILL 251
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#define WONT 252
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#define DO 253
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#define DONT 254
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#define IAC 255
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#define TN_TRANSMIT_BINARY 0
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#define TN_ECHO 1
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#define TN_SUPPRESS_GA 3
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static int tellen;
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char *envptr = NULL;
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time_t t_start, t_end;
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void die(int onsig)
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{
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signal(onsig, SIG_IGN);
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if (onsig) {
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if (onsig <= NSIG)
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WriteError("Terminated on signal %d (%s)", onsig, SigName[onsig]);
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else
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Syslog('+', "Terminated with error %d", onsig);
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}
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t_end = time(NULL);
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Syslog(' ', "MBTELNETD finished in %s", t_elapsed(t_start, t_end));
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if (envptr)
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free(envptr);
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ExitClient(onsig);
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}
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int main(int ac, char **av)
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{
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struct sockaddr_in peeraddr;
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int addrlen = sizeof(struct sockaddr_in);
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char *remote_name = NULL;
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char *remote_port = NULL;
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int s; /* socket to remote*/
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int i;
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struct hostent *hp;
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struct servent *sp;
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struct sockaddr_in server;
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char *tmp = NULL;
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struct passwd *pw;
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/*
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* The next trick is to supply a fake environment variable
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* MBSE_ROOT in case we are started from inetd or mgetty,
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* this will setup the variable so InitConfig() will work.
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* The /etc/passwd must point to the correct homedirectory.
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*/
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pw = getpwuid(getuid());
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if (getenv("MBSE_ROOT") == NULL) {
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envptr = xstrcpy((char *)"MBSE_ROOT=");
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envptr = xstrcat(envptr, pw->pw_dir);
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putenv(envptr);
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}
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InitConfig();
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t_start = time(NULL);
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InitClient(pw->pw_name, (char *)"mbtelnetd", CFG.location, CFG.logfile,
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CFG.util_loglevel, CFG.error_log, CFG.mgrlog, CFG.debuglog);
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Syslog(' ', " ");
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Syslog(' ', "MBTELNETDv%s", VERSION);
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/*
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* Catch all signals we can, and ignore the rest.
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*/
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for (i = 0; i < NSIG; i++) {
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if ((i == SIGINT) || (i == SIGBUS) || (i == SIGILL) || (i == SIGSEGV) || (i == SIGTERM) || (i == SIGKILL)) {
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signal(i, (void (*))die);
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} else {
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signal(i, SIG_IGN);
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}
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}
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remote_name = xstrcpy((char *)"localhost");
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remote_port = xstrcpy((char *)"fido");
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if (getpeername(0,(struct sockaddr*)&peeraddr,&addrlen) == 0) {
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tmp = strdup(inet_ntoa(peeraddr.sin_addr));
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Syslog('+', "Incoming TCP connection from %s", tmp ? tmp : "Unknown");
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Syslog('+', "Rerouting to %s:%s", remote_name, remote_port);
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}
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if (tmp)
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free(tmp);
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if ((sp = getservbyname(remote_port, "tcp")) == NULL) {
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WriteError("Can't find service: %s", remote_port);
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free(remote_name);
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free(remote_port);
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die(MBERR_INIT_ERROR);
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}
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if ((s = socket(AF_INET,SOCK_STREAM,0)) == -1) {
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WriteError("Can't create Internet domain socket");
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free(remote_name);
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free(remote_port);
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die(MBERR_INIT_ERROR);
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}
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if ((hp = gethostbyname(remote_name)) == NULL) {
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WriteError("%s - Unknown host", remote_name);
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free(remote_name);
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free(remote_port);
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die(MBERR_INIT_ERROR);
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}
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memset(&server,0,sizeof(server));
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memcpy((char *)&server.sin_addr,hp->h_addr,hp->h_length);
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server.sin_family=hp->h_addrtype;
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server.sin_port = sp->s_port;
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if (connect(s,(struct sockaddr *)&server,sizeof(server)) == -1) {
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WriteError("Can't connect %s", remote_name);
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free(remote_name);
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free(remote_port);
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die(MBERR_INIT_ERROR);
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}
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init_telnet();
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tmp = calloc(81, sizeof(char ));
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sprintf(tmp, "mbtelnetd v%s\r\n", VERSION);
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write1(tmp, strlen(tmp));
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free(tmp);
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com_gw(s);
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free(remote_name);
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free(remote_port);
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close(s);
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die(0);
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return 0;
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}
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/* --- This is an artwork of serge terekhov, 2:5000/13@fidonet :) --- */
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void answer (int tag, int opt)
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{
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char buf[3];
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char *r = (char *)"???";
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switch (tag) {
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case WILL:
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r = (char *)"WILL";
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break;
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case WONT:
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r = (char *)"WONT";
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break;
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case DO:
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r = (char *)"DO";
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break;
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case DONT:
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r = (char *)"DONT";
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break;
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}
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Syslog('s', "TELNET send %s %d", r, opt);
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buf[0] = IAC;
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buf[1] = tag;
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buf[2] = opt;
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if (write (1, buf, 3) != 3)
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WriteError("$answer cant send");
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}
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int init_telnet(void)
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{
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tellen = 0;
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answer (DO, TN_SUPPRESS_GA);
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answer (WILL, TN_SUPPRESS_GA);
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answer (DO, TN_TRANSMIT_BINARY);
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answer (WILL, TN_TRANSMIT_BINARY);
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answer (DO, TN_ECHO);
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answer (WILL, TN_ECHO);
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return 1;
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}
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int read0 (char *buf, int len)
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{
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int n = 0, m;
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char *q, *p;
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static char telbuf[4];
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while ((n == 0) && (n = read (0, buf + tellen, MBT_BUFSIZ - tellen)) > 0) {
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if (tellen) {
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memcpy(buf, telbuf, tellen);
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n += tellen;
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tellen = 0;
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}
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if (memchr (buf, IAC, n)) {
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for (p = q = buf; n--; )
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if ((m = (unsigned char)*q++) != IAC)
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*p++ = m;
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else {
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if (n < 2) {
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memcpy (telbuf, q - 1, tellen = n + 1);
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break;
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}
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--n;
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switch (m = (unsigned char)*q++) {
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case WILL: m = (unsigned char)*q++; --n;
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Syslog('s', "TELNET: recv WILL %d", m);
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if (m != TN_TRANSMIT_BINARY && m != TN_SUPPRESS_GA && m != TN_ECHO)
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answer (DONT, m);
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break;
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case WONT: m = *q++;
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--n;
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Syslog('s', "TELNET: recv WONT %d", m);
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break;
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case DO: m = (unsigned char)*q++;
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--n;
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Syslog('s', "TELNET: recv DO %d", m);
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if (m != TN_TRANSMIT_BINARY && m != TN_SUPPRESS_GA && m != TN_ECHO)
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answer (WONT, m);
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break;
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case DONT: m = (unsigned char)*q++;
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--n;
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Syslog('s', "TELNET: recv DONT %d", m);
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break;
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case IAC: *p++ = IAC;
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break;
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default: Syslog('s', "TELNET: recv IAC %d", m);
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break;
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}
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}
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n = p - buf;
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}
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}
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return n;
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}
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int write1 (char *buf, int len)
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{
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char *q;
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int k, l;
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l = len;
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while ((len > 0) && (q = memchr(buf, IAC, len))) {
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k = (q - buf) + 1;
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if ((write (1, buf, k) != k) || (write (1, q, 1) != 1)) {
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return -1;
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}
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buf += k;
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len -= k;
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}
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if ((len > 0) && write (1, buf, len) != len) {
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return -1;
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}
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return l;
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}
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void com_gw(int in)
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{
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fd_set fds;
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int n, fdsbits;
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static struct timeval tout = { MBT_TIMEOUT, 0 };
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unsigned char buf[MBT_BUFSIZ];
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alarm(0);
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fdsbits = in + 1;
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while (TRUE) {
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FD_ZERO(& fds);
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FD_SET (in, &fds);
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FD_SET (0 , &fds);
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FD_SET (1 , &fds);
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tout.tv_sec = MBT_TIMEOUT;
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tout.tv_usec = 0;
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if ((n = select(fdsbits, &fds, NULL, NULL, &tout)) > 0) {
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if (FD_ISSET(in, &fds)) {
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if ((n = read(in, buf, sizeof buf)) > 0) {
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if (write1(buf, n) < 0) {
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goto bad;
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}
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} else {
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goto bad;
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}
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}
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if (FD_ISSET(0, &fds)) {
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if ((n = read0(buf, sizeof buf)) > 0) {
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if (write(in, buf, n) < 0) goto bad;
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} else {
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goto bad;
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}
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}
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} else {
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goto bad;
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}
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}
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bad: ;
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}
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