1156 lines
28 KiB
C
1156 lines
28 KiB
C
/* $NetBSD: telnetd.c,v 1.56 2019/08/15 01:15:21 kamil Exp $ */
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/*
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* Copyright (C) 1997 and 1998 WIDE Project.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the project nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/*
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* Copyright (c) 1989, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
|
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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#ifndef lint
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__COPYRIGHT("@(#) Copyright (c) 1989, 1993\
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The Regents of the University of California. All rights reserved.");
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#if 0
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static char sccsid[] = "@(#)telnetd.c 8.4 (Berkeley) 5/30/95";
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#else
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__RCSID("$NetBSD: telnetd.c,v 1.56 2019/08/15 01:15:21 kamil Exp $");
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#endif
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#endif /* not lint */
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#include "telnetd.h"
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#include "pathnames.h"
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#include <arpa/inet.h>
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#include <err.h>
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#include <termcap.h>
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#include <limits.h>
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#ifdef KRB5
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#define Authenticator k5_Authenticator
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#include <krb5.h>
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#undef Authenticator
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#include <krb5/com_err.h>
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#endif
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#if defined(AUTHENTICATION) || defined(ENCRYPTION)
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#include <libtelnet/misc.h>
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#endif
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extern int require_hwpreauth;
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#ifdef KRB5
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extern krb5_context telnet_context;
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#endif
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int registerd_host_only = 0;
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/*
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* I/O data buffers,
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* pointers, and counters.
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*/
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char ptyibuf[BUFSIZ], *ptyip = ptyibuf;
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char ptyibuf2[BUFSIZ];
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int hostinfo = 1; /* do we print login banner? */
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static int debug = 0;
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int keepalive = 1;
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const char *gettyname = "default";
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char *progname;
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void usage(void) __dead;
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int getterminaltype(char *, size_t);
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int getent(char *, const char *);
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static void doit(struct sockaddr *) __dead;
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void _gettermname(void);
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int terminaltypeok(char *);
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char *getstr(const char *, char **);
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/*
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* The string to pass to getopt(). We do it this way so
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* that only the actual options that we support will be
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* passed off to getopt().
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*/
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char valid_opts[] = {
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'd', ':', 'g', ':', 'h', 'k', 'n', 'S', ':', 'u', ':', 'U',
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'4', '6',
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#ifdef AUTHENTICATION
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'a', ':', 'X', ':',
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#endif
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#ifdef ENCRYPTION
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'e', ':',
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#endif
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#ifdef DIAGNOSTICS
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'D', ':',
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#endif
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#ifdef LINEMODE
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'l',
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#endif
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#ifdef SECURELOGIN
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's',
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#endif
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#ifdef KRB5
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'R', ':', 'H',
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#endif
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'\0'
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};
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int family = AF_INET;
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struct sockaddr_storage from;
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int
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main(int argc, char *argv[])
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{
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static char Xline[] = NULL16STR;
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socklen_t fromlen;
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int on = 1;
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int ch;
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#if defined(IPPROTO_IP) && defined(IP_TOS)
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int tos = -1;
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#endif
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line = Xline;
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pfrontp = pbackp = ptyobuf;
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netip = netibuf;
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nfrontp = nbackp = netobuf;
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#ifdef ENCRYPTION
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nclearto = 0;
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#endif /* ENCRYPTION */
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progname = *argv;
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while ((ch = getopt(argc, argv, valid_opts)) != -1) {
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switch (ch) {
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#ifdef AUTHENTICATION
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case 'a':
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/*
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* Check for required authentication level
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*/
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if (strcmp(optarg, "debug") == 0) {
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auth_debug_mode = 1;
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} else if (strcasecmp(optarg, "none") == 0) {
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auth_level = 0;
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} else if (strcasecmp(optarg, "other") == 0) {
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auth_level = AUTH_OTHER;
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} else if (strcasecmp(optarg, "user") == 0) {
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auth_level = AUTH_USER;
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} else if (strcasecmp(optarg, "valid") == 0) {
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auth_level = AUTH_VALID;
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} else if (strcasecmp(optarg, "off") == 0) {
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/*
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* This hack turns off authentication
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*/
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auth_level = -1;
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} else {
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fprintf(stderr,
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"telnetd: unknown authorization level for -a\n");
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}
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break;
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#endif /* AUTHENTICATION */
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case 'd':
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if (strcmp(optarg, "ebug") == 0) {
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debug++;
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break;
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}
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usage();
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/* NOTREACHED */
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break;
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#ifdef DIAGNOSTICS
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case 'D':
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/*
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* Check for desired diagnostics capabilities.
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*/
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if (!strcmp(optarg, "report")) {
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diagnostic |= TD_REPORT|TD_OPTIONS;
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} else if (!strcmp(optarg, "exercise")) {
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diagnostic |= TD_EXERCISE;
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} else if (!strcmp(optarg, "netdata")) {
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diagnostic |= TD_NETDATA;
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} else if (!strcmp(optarg, "ptydata")) {
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diagnostic |= TD_PTYDATA;
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} else if (!strcmp(optarg, "options")) {
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diagnostic |= TD_OPTIONS;
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} else {
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usage();
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/* NOT REACHED */
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}
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break;
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#endif /* DIAGNOSTICS */
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#ifdef ENCRYPTION
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case 'e':
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if (strcmp(optarg, "debug") == 0) {
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encrypt_debug_mode = 1;
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break;
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}
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usage();
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/* NOTREACHED */
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break;
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#endif /* ENCRYPTION */
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case 'g':
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gettyname = optarg;
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break;
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case 'h':
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hostinfo = 0;
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break;
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#ifdef KRB5
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case 'H':
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{
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require_hwpreauth = 1;
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break;
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}
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#endif /* KRB5 */
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#ifdef LINEMODE
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case 'l':
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alwayslinemode = 1;
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break;
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#endif /* LINEMODE */
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case 'k':
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#if defined(LINEMODE) && defined(KLUDGELINEMODE)
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lmodetype = NO_AUTOKLUDGE;
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#else
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/* ignore -k option if built without kludge linemode */
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#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
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break;
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case 'n':
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keepalive = 0;
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break;
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#ifdef KRB5
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case 'R':
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{
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krb5_error_code retval;
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if (telnet_context == 0) {
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retval = krb5_init_context(&telnet_context);
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if (retval) {
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com_err("telnetd", retval,
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"while initializing krb5");
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exit(1);
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}
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}
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krb5_set_default_realm(telnet_context, optarg);
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break;
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}
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#endif /* KRB5 */
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#ifdef SECURELOGIN
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case 's':
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/* Secure login required */
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require_secure_login = 1;
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break;
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#endif /* SECURELOGIN */
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case 'S':
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fprintf(stderr, "%s%s\n", "TOS option unavailable; ",
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"-S flag not supported\n");
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break;
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case 'u':
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fprintf(stderr, "telnetd: -u option unneeded\n");
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break;
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case 'U':
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registerd_host_only = 1;
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break;
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#ifdef AUTHENTICATION
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case 'X':
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/*
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* Check for invalid authentication types
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*/
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auth_disable_name(optarg);
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break;
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#endif /* AUTHENTICATION */
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case '4':
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family = AF_INET;
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break;
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case '6':
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family = AF_INET6;
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break;
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default:
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fprintf(stderr, "telnetd: %c: unknown option\n", ch);
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/* FALLTHROUGH */
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case '?':
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usage();
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/* NOTREACHED */
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}
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}
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argc -= optind;
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argv += optind;
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if (debug) {
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int s, ns, error;
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socklen_t foo;
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const char *service = "telnet";
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struct addrinfo hints, *res;
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if (argc > 1) {
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usage();
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/* NOT REACHED */
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} else if (argc == 1)
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service = *argv;
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memset(&hints, 0, sizeof(hints));
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hints.ai_flags = AI_PASSIVE;
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hints.ai_family = family;
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hints.ai_socktype = SOCK_STREAM;
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hints.ai_protocol = 0;
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error = getaddrinfo(NULL, service, &hints, &res);
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if (error) {
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fprintf(stderr, "tcp/%s: %s\n", service, gai_strerror(error));
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exit(1);
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}
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s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
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if (s < 0) {
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perror("telnetd: socket");
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exit(1);
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}
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(void) setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
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(char *)&on, sizeof(on));
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if (bind(s, res->ai_addr, res->ai_addrlen) < 0) {
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perror("bind");
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exit(1);
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}
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if (listen(s, 1) < 0) {
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perror("listen");
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exit(1);
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}
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foo = res->ai_addrlen;
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ns = accept(s, res->ai_addr, &foo);
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if (ns < 0) {
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perror("accept");
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exit(1);
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}
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(void) dup2(ns, 0);
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(void) close(ns);
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(void) close(s);
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} else if (argc > 0) {
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usage();
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/* NOT REACHED */
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}
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openlog("telnetd", LOG_PID, LOG_DAEMON);
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fromlen = sizeof (from);
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if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) {
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fprintf(stderr, "%s: ", progname);
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perror("getpeername");
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_exit(1);
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}
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if (keepalive &&
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setsockopt(0, SOL_SOCKET, SO_KEEPALIVE,
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(char *)&on, sizeof (on)) < 0) {
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syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
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}
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#if defined(IPPROTO_IP) && defined(IP_TOS)
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if (((struct sockaddr *)&from)->sa_family == AF_INET) {
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if (tos < 0)
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tos = 020; /* Low Delay bit */
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if (tos
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&& (setsockopt(0, IPPROTO_IP, IP_TOS,
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(char *)&tos, sizeof(tos)) < 0)
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&& (errno != ENOPROTOOPT) )
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syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
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}
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#endif /* defined(IPPROTO_IP) && defined(IP_TOS) */
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net = 0;
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doit((struct sockaddr *)&from);
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/* NOTREACHED */
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#ifdef __GNUC__
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exit(0);
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#endif
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} /* end of main */
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void
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usage(void)
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{
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fprintf(stderr, "Usage: telnetd");
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#ifdef AUTHENTICATION
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fprintf(stderr, " [-a (debug|other|user|valid|off|none)]\n\t");
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#endif
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fprintf(stderr, " [-debug]");
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#ifdef DIAGNOSTICS
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fprintf(stderr, " [-D (options|report|exercise|netdata|ptydata)]\n\t");
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#endif
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#ifdef ENCRYPTION
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fprintf(stderr, " [-edebug]");
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#endif
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fprintf(stderr, " [-h]");
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#if defined(LINEMODE) && defined(KLUDGELINEMODE)
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fprintf(stderr, " [-k]");
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#endif
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#ifdef LINEMODE
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fprintf(stderr, " [-l]");
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#endif
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fprintf(stderr, " [-n]");
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fprintf(stderr, "\n\t");
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#ifdef SECURELOGIN
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fprintf(stderr, " [-s]");
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#endif
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#ifdef AUTHENTICATION
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fprintf(stderr, " [-X auth-type]");
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#endif
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fprintf(stderr, " [-u utmp_hostname_length] [-U]");
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fprintf(stderr, " [port]\n");
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exit(1);
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}
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|
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/*
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* getterminaltype
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|
*
|
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* Ask the other end to send along its terminal type and speed.
|
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* Output is the variable terminaltype filled in.
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*/
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static unsigned char ttytype_sbbuf[] = {
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IAC, SB, TELOPT_TTYPE, TELQUAL_SEND, IAC, SE
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};
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|
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int
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getterminaltype(char *name, size_t l)
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{
|
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int retval = -1;
|
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|
|
settimer(baseline);
|
|
#ifdef AUTHENTICATION
|
|
/*
|
|
* Handle the Authentication option before we do anything else.
|
|
*/
|
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send_do(TELOPT_AUTHENTICATION, 1);
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while (his_will_wont_is_changing(TELOPT_AUTHENTICATION))
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ttloop();
|
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if (his_state_is_will(TELOPT_AUTHENTICATION)) {
|
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retval = auth_wait(name, l);
|
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}
|
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#endif
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|
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#ifdef ENCRYPTION
|
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send_will(TELOPT_ENCRYPT, 1);
|
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#endif /* ENCRYPTION */
|
|
send_do(TELOPT_TTYPE, 1);
|
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send_do(TELOPT_TSPEED, 1);
|
|
send_do(TELOPT_XDISPLOC, 1);
|
|
send_do(TELOPT_NEW_ENVIRON, 1);
|
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send_do(TELOPT_OLD_ENVIRON, 1);
|
|
while (
|
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#ifdef ENCRYPTION
|
|
his_do_dont_is_changing(TELOPT_ENCRYPT) ||
|
|
#endif /* ENCRYPTION */
|
|
his_will_wont_is_changing(TELOPT_TTYPE) ||
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his_will_wont_is_changing(TELOPT_TSPEED) ||
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his_will_wont_is_changing(TELOPT_XDISPLOC) ||
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his_will_wont_is_changing(TELOPT_NEW_ENVIRON) ||
|
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his_will_wont_is_changing(TELOPT_OLD_ENVIRON)) {
|
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ttloop();
|
|
}
|
|
if (his_state_is_will(TELOPT_TSPEED)) {
|
|
static unsigned char sb[] =
|
|
{ IAC, SB, TELOPT_TSPEED, TELQUAL_SEND, IAC, SE };
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|
|
output_datalen((const char *)sb, sizeof sb);
|
|
DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
|
|
}
|
|
#ifdef ENCRYPTION
|
|
/*
|
|
* Wait for the negotiation of what type of encryption we can
|
|
* send with. If autoencrypt is not set, this will just return.
|
|
*/
|
|
if (his_state_is_will(TELOPT_ENCRYPT)) {
|
|
encrypt_wait();
|
|
}
|
|
#endif /* ENCRYPTION */
|
|
if (his_state_is_will(TELOPT_XDISPLOC)) {
|
|
static unsigned char sb[] =
|
|
{ IAC, SB, TELOPT_XDISPLOC, TELQUAL_SEND, IAC, SE };
|
|
|
|
output_datalen((const char *)sb, sizeof sb);
|
|
DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
|
|
}
|
|
if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
|
|
static unsigned char sb[] =
|
|
{ IAC, SB, TELOPT_NEW_ENVIRON, TELQUAL_SEND, IAC, SE };
|
|
|
|
output_datalen((const char *)sb, sizeof sb);
|
|
DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
|
|
}
|
|
else if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
|
|
static unsigned char sb[] =
|
|
{ IAC, SB, TELOPT_OLD_ENVIRON, TELQUAL_SEND, IAC, SE };
|
|
|
|
output_datalen((const char *)sb, sizeof sb);
|
|
DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
|
|
}
|
|
if (his_state_is_will(TELOPT_TTYPE)) {
|
|
|
|
output_datalen((const char *)ttytype_sbbuf, sizeof ttytype_sbbuf);
|
|
DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
|
|
sizeof ttytype_sbbuf - 2););
|
|
}
|
|
if (his_state_is_will(TELOPT_TSPEED)) {
|
|
while (sequenceIs(tspeedsubopt, baseline))
|
|
ttloop();
|
|
}
|
|
if (his_state_is_will(TELOPT_XDISPLOC)) {
|
|
while (sequenceIs(xdisplocsubopt, baseline))
|
|
ttloop();
|
|
}
|
|
if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
|
|
while (sequenceIs(environsubopt, baseline))
|
|
ttloop();
|
|
}
|
|
if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
|
|
while (sequenceIs(oenvironsubopt, baseline))
|
|
ttloop();
|
|
}
|
|
if (his_state_is_will(TELOPT_TTYPE)) {
|
|
char first[256], last[256];
|
|
|
|
while (sequenceIs(ttypesubopt, baseline))
|
|
ttloop();
|
|
|
|
/*
|
|
* If the other side has already disabled the option, then
|
|
* we have to just go with what we (might) have already gotten.
|
|
*/
|
|
if (his_state_is_will(TELOPT_TTYPE) && !terminaltypeok(terminaltype)) {
|
|
(void) strlcpy(first, terminaltype, sizeof(first));
|
|
for(;;) {
|
|
/*
|
|
* Save the unknown name, and request the next name.
|
|
*/
|
|
(void) strlcpy(last, terminaltype, sizeof(last));
|
|
_gettermname();
|
|
if (terminaltypeok(terminaltype))
|
|
break;
|
|
if ((strncmp(last, terminaltype, sizeof(last)) == 0) ||
|
|
his_state_is_wont(TELOPT_TTYPE)) {
|
|
/*
|
|
* We've hit the end. If this is the same as
|
|
* the first name, just go with it.
|
|
*/
|
|
if (strncmp(first, terminaltype, sizeof(first)) == 0)
|
|
break;
|
|
/*
|
|
* Get the terminal name one more time, so that
|
|
* RFC1091 compliant telnets will cycle back to
|
|
* the start of the list.
|
|
*/
|
|
_gettermname();
|
|
if (strncmp(first, terminaltype, sizeof(first)) != 0) {
|
|
(void) strlcpy(terminaltype, first, sizeof(terminaltype));
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return(retval);
|
|
} /* end of getterminaltype */
|
|
|
|
void
|
|
_gettermname(void)
|
|
{
|
|
/*
|
|
* If the client turned off the option,
|
|
* we can't send another request, so we
|
|
* just return.
|
|
*/
|
|
if (his_state_is_wont(TELOPT_TTYPE))
|
|
return;
|
|
settimer(baseline);
|
|
output_datalen((const char *)ttytype_sbbuf, sizeof ttytype_sbbuf);
|
|
DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
|
|
sizeof ttytype_sbbuf - 2););
|
|
while (sequenceIs(ttypesubopt, baseline))
|
|
ttloop();
|
|
}
|
|
|
|
int
|
|
terminaltypeok(char *s)
|
|
{
|
|
char buf[1024];
|
|
|
|
/*
|
|
* tgetent() will return 1 if the type is known, and
|
|
* 0 if it is not known. If it returns -1, it couldn't
|
|
* open the database. But if we can't open the database,
|
|
* it won't help to say we failed, because we won't be
|
|
* able to verify anything else. So, we treat -1 like 1.
|
|
*/
|
|
if (tgetent(buf, s) == 0)
|
|
return(0);
|
|
return(1);
|
|
}
|
|
|
|
char *hostname;
|
|
char host_name[MAXHOSTNAMELEN + 1];
|
|
char remote_host_name[MAXHOSTNAMELEN + 1];
|
|
|
|
static void telnet(int, int) __dead;
|
|
|
|
/*
|
|
* Get a pty, scan input lines.
|
|
*/
|
|
static void
|
|
doit(struct sockaddr *who)
|
|
{
|
|
char *host;
|
|
int error;
|
|
int level;
|
|
int ptynum;
|
|
int flags;
|
|
char user_name[256];
|
|
|
|
/*
|
|
* Find an available pty to use.
|
|
*/
|
|
pty = getpty(&ptynum);
|
|
if (pty < 0)
|
|
fatal(net, "All network ports in use");
|
|
|
|
flags = registerd_host_only ? NI_NAMEREQD : 0;
|
|
|
|
/* get name of connected client */
|
|
error = getnameinfo(who, who->sa_len, remote_host_name,
|
|
sizeof(remote_host_name), NULL, 0, flags);
|
|
|
|
if (error) {
|
|
fatal(net, "Couldn't resolve your address into a host name.\r\n\
|
|
Please contact your net administrator");
|
|
#ifdef __GNUC__
|
|
host = NULL; /* XXX gcc */
|
|
#endif
|
|
}
|
|
|
|
remote_host_name[sizeof(remote_host_name)-1] = 0;
|
|
host = remote_host_name;
|
|
|
|
(void)gethostname(host_name, sizeof(host_name));
|
|
host_name[sizeof(host_name) - 1] = '\0';
|
|
hostname = host_name;
|
|
|
|
#if defined(AUTHENTICATION) || defined(ENCRYPTION)
|
|
auth_encrypt_init(hostname, host, "TELNETD", 1);
|
|
#endif
|
|
|
|
init_env();
|
|
/*
|
|
* get terminal type.
|
|
*/
|
|
*user_name = 0;
|
|
level = getterminaltype(user_name, sizeof(user_name));
|
|
setenv("TERM", terminaltype[0] ? terminaltype : "network", 1);
|
|
|
|
/*
|
|
* Start up the login process on the slave side of the terminal
|
|
*/
|
|
startslave(host, level, user_name);
|
|
|
|
telnet(net, pty); /* begin server processing */
|
|
/*NOTREACHED*/
|
|
} /* end of doit */
|
|
|
|
|
|
/*
|
|
* Main loop. Select from pty and network, and
|
|
* hand data to telnet receiver finite state machine.
|
|
*/
|
|
static void
|
|
telnet(int f, int p)
|
|
{
|
|
int on = 1;
|
|
#define TABBUFSIZ 512
|
|
char defent[TABBUFSIZ];
|
|
char defstrs[TABBUFSIZ];
|
|
#undef TABBUFSIZ
|
|
char *HE, *HN, *IF, *ptyibuf2ptr;
|
|
const char *IM;
|
|
struct pollfd set[2];
|
|
|
|
/*
|
|
* Initialize the slc mapping table.
|
|
*/
|
|
get_slc_defaults();
|
|
|
|
/*
|
|
* Do some tests where it is desireable to wait for a response.
|
|
* Rather than doing them slowly, one at a time, do them all
|
|
* at once.
|
|
*/
|
|
if (my_state_is_wont(TELOPT_SGA))
|
|
send_will(TELOPT_SGA, 1);
|
|
/*
|
|
* Is the client side a 4.2 (NOT 4.3) system? We need to know this
|
|
* because 4.2 clients are unable to deal with TCP urgent data.
|
|
*
|
|
* To find out, we send out a "DO ECHO". If the remote system
|
|
* answers "WILL ECHO" it is probably a 4.2 client, and we note
|
|
* that fact ("WILL ECHO" ==> that the client will echo what
|
|
* WE, the server, sends it; it does NOT mean that the client will
|
|
* echo the terminal input).
|
|
*/
|
|
send_do(TELOPT_ECHO, 1);
|
|
|
|
#ifdef LINEMODE
|
|
if (his_state_is_wont(TELOPT_LINEMODE)) {
|
|
/* Query the peer for linemode support by trying to negotiate
|
|
* the linemode option.
|
|
*/
|
|
linemode = 0;
|
|
editmode = 0;
|
|
send_do(TELOPT_LINEMODE, 1); /* send do linemode */
|
|
}
|
|
#endif /* LINEMODE */
|
|
|
|
/*
|
|
* Send along a couple of other options that we wish to negotiate.
|
|
*/
|
|
send_do(TELOPT_NAWS, 1);
|
|
send_will(TELOPT_STATUS, 1);
|
|
flowmode = 1; /* default flow control state */
|
|
restartany = -1; /* uninitialized... */
|
|
send_do(TELOPT_LFLOW, 1);
|
|
|
|
/*
|
|
* Spin, waiting for a response from the DO ECHO. However,
|
|
* some REALLY DUMB telnets out there might not respond
|
|
* to the DO ECHO. So, we spin looking for NAWS, (most dumb
|
|
* telnets so far seem to respond with WONT for a DO that
|
|
* they don't understand...) because by the time we get the
|
|
* response, it will already have processed the DO ECHO.
|
|
* Kludge upon kludge.
|
|
*/
|
|
while (his_will_wont_is_changing(TELOPT_NAWS))
|
|
ttloop();
|
|
|
|
/*
|
|
* But...
|
|
* The client might have sent a WILL NAWS as part of its
|
|
* startup code; if so, we'll be here before we get the
|
|
* response to the DO ECHO. We'll make the assumption
|
|
* that any implementation that understands about NAWS
|
|
* is a modern enough implementation that it will respond
|
|
* to our DO ECHO request; hence we'll do another spin
|
|
* waiting for the ECHO option to settle down, which is
|
|
* what we wanted to do in the first place...
|
|
*/
|
|
if (his_want_state_is_will(TELOPT_ECHO) &&
|
|
his_state_is_will(TELOPT_NAWS)) {
|
|
while (his_will_wont_is_changing(TELOPT_ECHO))
|
|
ttloop();
|
|
}
|
|
/*
|
|
* On the off chance that the telnet client is broken and does not
|
|
* respond to the DO ECHO we sent, (after all, we did send the
|
|
* DO NAWS negotiation after the DO ECHO, and we won't get here
|
|
* until a response to the DO NAWS comes back) simulate the
|
|
* receipt of a will echo. This will also send a WONT ECHO
|
|
* to the client, since we assume that the client failed to
|
|
* respond because it believes that it is already in DO ECHO
|
|
* mode, which we do not want.
|
|
*/
|
|
if (his_want_state_is_will(TELOPT_ECHO)) {
|
|
DIAG(TD_OPTIONS,
|
|
{output_data("td: simulating recv\r\n");});
|
|
willoption(TELOPT_ECHO);
|
|
}
|
|
|
|
/*
|
|
* Finally, to clean things up, we turn on our echo. This
|
|
* will break stupid 4.2 telnets out of local terminal echo.
|
|
*/
|
|
|
|
if (my_state_is_wont(TELOPT_ECHO))
|
|
send_will(TELOPT_ECHO, 1);
|
|
|
|
/*
|
|
* Turn on packet mode
|
|
*/
|
|
(void) ioctl(p, TIOCPKT, (char *)&on);
|
|
|
|
#if defined(LINEMODE) && defined(KLUDGELINEMODE)
|
|
/*
|
|
* Continuing line mode support. If client does not support
|
|
* real linemode, attempt to negotiate kludge linemode by sending
|
|
* the do timing mark sequence.
|
|
*/
|
|
if (lmodetype < REAL_LINEMODE)
|
|
send_do(TELOPT_TM, 1);
|
|
#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
|
|
|
|
/*
|
|
* Call telrcv() once to pick up anything received during
|
|
* terminal type negotiation, 4.2/4.3 determination, and
|
|
* linemode negotiation.
|
|
*/
|
|
telrcv();
|
|
|
|
(void) ioctl(f, FIONBIO, (char *)&on);
|
|
(void) ioctl(p, FIONBIO, (char *)&on);
|
|
|
|
(void) setsockopt(f, SOL_SOCKET, SO_OOBINLINE, (char *)&on, sizeof on);
|
|
|
|
(void) signal(SIGTSTP, SIG_IGN);
|
|
/*
|
|
* Ignoring SIGTTOU keeps the kernel from blocking us
|
|
* in ttioct() in /sys/tty.c.
|
|
*/
|
|
(void) signal(SIGTTOU, SIG_IGN);
|
|
|
|
(void) signal(SIGCHLD, cleanup);
|
|
|
|
|
|
{
|
|
int t;
|
|
t = open(_PATH_TTY, O_RDWR);
|
|
if (t >= 0) {
|
|
(void) ioctl(t, TIOCNOTTY, (char *)0);
|
|
(void) close(t);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Show banner that getty never gave.
|
|
*
|
|
* We put the banner in the pty input buffer. This way, it
|
|
* gets carriage return null processing, etc., just like all
|
|
* other pty --> client data.
|
|
*/
|
|
|
|
if (getent(defent, gettyname) == 1) {
|
|
char *cp=defstrs;
|
|
|
|
HE = getstr("he", &cp);
|
|
HN = getstr("hn", &cp);
|
|
IM = getstr("im", &cp);
|
|
IF = getstr("if", &cp);
|
|
if (HN && *HN)
|
|
(void)strlcpy(host_name, HN, sizeof(host_name));
|
|
if (IM == 0)
|
|
IM = "";
|
|
} else {
|
|
IM = DEFAULT_IM;
|
|
HE = 0;
|
|
IF = NULL;
|
|
}
|
|
edithost(HE, host_name);
|
|
ptyibuf2ptr = ptyibuf2;
|
|
if (hostinfo) {
|
|
if (IF) {
|
|
char buf[_POSIX2_LINE_MAX];
|
|
FILE *fd;
|
|
|
|
if ((fd = fopen(IF, "r")) != NULL) {
|
|
while (fgets(buf, sizeof(buf) - 1, fd) != NULL)
|
|
ptyibuf2ptr = putf(buf, ptyibuf2ptr);
|
|
fclose(fd);
|
|
}
|
|
}
|
|
if (*IM)
|
|
ptyibuf2ptr = putf(IM, ptyibuf2ptr);
|
|
}
|
|
|
|
if (pcc)
|
|
strncpy(ptyibuf2ptr, ptyip, pcc+1);
|
|
ptyip = ptyibuf2;
|
|
pcc = strlen(ptyip);
|
|
#ifdef LINEMODE
|
|
/*
|
|
* Last check to make sure all our states are correct.
|
|
*/
|
|
init_termbuf();
|
|
localstat();
|
|
#endif /* LINEMODE */
|
|
|
|
DIAG(TD_REPORT,
|
|
{output_data("td: Entering processing loop\r\n");});
|
|
|
|
|
|
set[0].fd = f;
|
|
set[1].fd = p;
|
|
for (;;) {
|
|
int c;
|
|
|
|
if (ncc < 0 && pcc < 0)
|
|
break;
|
|
|
|
/*
|
|
* Never look for input if there's still
|
|
* stuff in the corresponding output buffer
|
|
*/
|
|
set[0].events = 0;
|
|
set[1].events = 0;
|
|
if (nfrontp - nbackp || pcc > 0)
|
|
set[0].events |= POLLOUT;
|
|
else
|
|
set[1].events |= POLLIN;
|
|
if (pfrontp - pbackp || ncc > 0)
|
|
set[1].events |= POLLOUT;
|
|
else
|
|
set[0].events |= POLLIN;
|
|
if (!SYNCHing)
|
|
set[0].events |= POLLPRI;
|
|
|
|
if ((c = poll(set, 2, INFTIM)) < 1) {
|
|
if (c == -1) {
|
|
if (errno == EINTR) {
|
|
continue;
|
|
}
|
|
}
|
|
sleep(5);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Any urgent data?
|
|
*/
|
|
if (set[0].revents & POLLPRI) {
|
|
SYNCHing = 1;
|
|
}
|
|
|
|
/*
|
|
* Something to read from the network...
|
|
*/
|
|
if (set[0].revents & POLLIN) {
|
|
ncc = read(f, netibuf, sizeof (netibuf));
|
|
if (ncc < 0 && errno == EWOULDBLOCK)
|
|
ncc = 0;
|
|
else {
|
|
if (ncc <= 0) {
|
|
break;
|
|
}
|
|
netip = netibuf;
|
|
}
|
|
DIAG((TD_REPORT | TD_NETDATA),
|
|
{output_data("td: netread %d chars\r\n", ncc);});
|
|
DIAG(TD_NETDATA, printdata("nd", netip, ncc));
|
|
}
|
|
|
|
/*
|
|
* Something to read from the pty...
|
|
*/
|
|
if (set[1].revents & POLLIN) {
|
|
pcc = read(p, ptyibuf, BUFSIZ);
|
|
/*
|
|
* On some systems, if we try to read something
|
|
* off the master side before the slave side is
|
|
* opened, we get EIO.
|
|
*/
|
|
if (pcc < 0 && (errno == EWOULDBLOCK ||
|
|
errno == EAGAIN ||
|
|
errno == EIO)) {
|
|
pcc = 0;
|
|
} else {
|
|
if (pcc <= 0)
|
|
break;
|
|
#ifdef LINEMODE
|
|
/*
|
|
* If ioctl from pty, pass it through net
|
|
*/
|
|
if (ptyibuf[0] & TIOCPKT_IOCTL) {
|
|
copy_termbuf(ptyibuf+1, pcc-1);
|
|
localstat();
|
|
pcc = 1;
|
|
}
|
|
#endif /* LINEMODE */
|
|
if (ptyibuf[0] & TIOCPKT_FLUSHWRITE) {
|
|
netclear(); /* clear buffer back */
|
|
/*
|
|
* There are client telnets on some
|
|
* operating systems get screwed up
|
|
* royally if we send them urgent
|
|
* mode data.
|
|
*/
|
|
output_data("%c%c", IAC, DM);
|
|
neturg = nfrontp - 1; /* off by one XXX */
|
|
DIAG(TD_OPTIONS,
|
|
printoption("td: send IAC", DM));
|
|
}
|
|
if (his_state_is_will(TELOPT_LFLOW) &&
|
|
(ptyibuf[0] &
|
|
(TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))) {
|
|
int newflow =
|
|
ptyibuf[0] & TIOCPKT_DOSTOP ? 1 : 0;
|
|
if (newflow != flowmode) {
|
|
flowmode = newflow;
|
|
(void) output_data(
|
|
"%c%c%c%c%c%c",
|
|
IAC, SB, TELOPT_LFLOW,
|
|
flowmode ? LFLOW_ON
|
|
: LFLOW_OFF,
|
|
IAC, SE);
|
|
DIAG(TD_OPTIONS, printsub('>',
|
|
(unsigned char *)nfrontp - 4,
|
|
4););
|
|
}
|
|
}
|
|
pcc--;
|
|
ptyip = ptyibuf+1;
|
|
}
|
|
}
|
|
|
|
while (pcc > 0) {
|
|
if ((&netobuf[BUFSIZ] - nfrontp) < 2)
|
|
break;
|
|
c = *ptyip++ & 0377, pcc--;
|
|
if (c == IAC)
|
|
output_data("%c", c);
|
|
output_data("%c", c);
|
|
if ((c == '\r') && (my_state_is_wont(TELOPT_BINARY))) {
|
|
if (pcc > 0 && ((*ptyip & 0377) == '\n')) {
|
|
output_data("%c", *ptyip++ & 0377);
|
|
pcc--;
|
|
} else
|
|
output_datalen("\0", 1);
|
|
}
|
|
}
|
|
|
|
if ((set[0].revents & POLLOUT) && (nfrontp - nbackp) > 0)
|
|
netflush();
|
|
if (ncc > 0)
|
|
telrcv();
|
|
if ((set[1].revents & POLLOUT) && (pfrontp - pbackp) > 0)
|
|
ptyflush();
|
|
}
|
|
cleanup(0);
|
|
} /* end of telnet */
|
|
|
|
/*
|
|
* Send interrupt to process on other side of pty.
|
|
* If it is in raw mode, just write NULL;
|
|
* otherwise, write intr char.
|
|
*/
|
|
void
|
|
interrupt(void)
|
|
{
|
|
ptyflush(); /* half-hearted */
|
|
|
|
(void) ioctl(pty, TIOCSIG, (char *)SIGINT);
|
|
}
|
|
|
|
/*
|
|
* Send quit to process on other side of pty.
|
|
* If it is in raw mode, just write NULL;
|
|
* otherwise, write quit char.
|
|
*/
|
|
void
|
|
sendbrk(void)
|
|
{
|
|
ptyflush(); /* half-hearted */
|
|
(void) ioctl(pty, TIOCSIG, (char *)SIGQUIT);
|
|
}
|
|
|
|
void
|
|
sendsusp(void)
|
|
{
|
|
ptyflush(); /* half-hearted */
|
|
(void) ioctl(pty, TIOCSIG, (char *)SIGTSTP);
|
|
}
|
|
|
|
/*
|
|
* When we get an AYT, if ^T is enabled, use that. Otherwise,
|
|
* just send back "[Yes]".
|
|
*/
|
|
void
|
|
recv_ayt(void)
|
|
{
|
|
if (slctab[SLC_AYT].sptr && *slctab[SLC_AYT].sptr != _POSIX_VDISABLE) {
|
|
(void) ioctl(pty, TIOCSIG, (char *)SIGINFO);
|
|
return;
|
|
}
|
|
(void) output_data("\r\n[Yes]\r\n");
|
|
}
|
|
|
|
void
|
|
doeof(void)
|
|
{
|
|
init_termbuf();
|
|
|
|
#if defined(LINEMODE) && (VEOF == VMIN)
|
|
if (!tty_isediting()) {
|
|
extern char oldeofc;
|
|
*pfrontp++ = oldeofc;
|
|
return;
|
|
}
|
|
#endif
|
|
*pfrontp++ = slctab[SLC_EOF].sptr ?
|
|
(unsigned char)*slctab[SLC_EOF].sptr : '\004';
|
|
}
|