network_cmds-245.15.tar.gz

[apple/network_cmds.git] / telnet.tproj / commands.c

/*
 * Copyright (c) 1988, 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>

#ifdef __FBSDID
__FBSDID("$FreeBSD: src/crypto/telnet/telnet/commands.c,v 1.12.2.5 2002/04/13 10:59:08 markm Exp $");
#endif

#ifndef __unused
#define __unused        __attribute__((__unused__))
#endif

#ifndef lint
static const char sccsid[] = "@(#)commands.c    8.4 (Berkeley) 5/30/95";
#endif

#include <sys/param.h>
#include <sys/un.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <netinet/in.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <netdb.h>
#include <pwd.h>
#include <signal.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <arpa/telnet.h>
#include <arpa/inet.h>

#include "general.h"

#include "ring.h"

#include "externs.h"
#include "defines.h"
#include "types.h"
#include "misc.h"

#ifdef  AUTHENTICATION
#include <libtelnet/auth.h>
#endif
#ifdef  ENCRYPTION
#include <libtelnet/encrypt.h>
#endif

#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>

#ifndef       MAXHOSTNAMELEN
#define       MAXHOSTNAMELEN 256
#endif        MAXHOSTNAMELEN

typedef int (*intrtn_t)(int, char **);

#ifdef  AUTHENTICATION
extern int auth_togdebug(int);
#endif
#ifdef  ENCRYPTION
extern int EncryptAutoEnc(int);
extern int EncryptAutoDec(int);
extern int EncryptDebug(int);
extern int EncryptVerbose(int);
#endif  /* ENCRYPTION */
#if     defined(IPPROTO_IP) && defined(IP_TOS)
int tos = -1;
#endif  /* defined(IPPROTO_IP) && defined(IP_TOS) */

char    *hostname;
static char _hostname[MAXHOSTNAMELEN];

static int help(int, char **);
static int call(intrtn_t, ...);
static void cmdrc(char *, char *);
#ifdef INET6
static int switch_af(struct addrinfo **);
#endif
static int togglehelp(void);
static int send_tncmd(void (*)(int, int), const char *, char *);
static int setmod(int);
static int clearmode(int);
static int modehelp(void);
static int sourceroute(struct addrinfo *, char *, char **, int *, int *, int *);

typedef struct {
        const char *name;       /* command name */
        const char *help;       /* help string (NULL for no help) */
        int     (*handler)(int, char **); /* routine which executes command */
        int     needconnect;    /* Do we need to be connected to execute? */
} Command;

static char line[256];
static char saveline[256];
static int margc;
static char *margv[20];

#ifdef OPIE
#include <sys/wait.h>
#define PATH_OPIEKEY    "/usr/bin/opiekey"
static int
opie_calc(int argc, char *argv[])
{
        int status;

        if(argc != 3) {
                printf("%s sequence challenge\n", argv[0]);
                return (0);
        }

        switch(fork()) {
        case 0:
                execv(PATH_OPIEKEY, argv);
                exit (1);
        case -1:
                perror("fork");
                break;
        default:
                (void) wait(&status);
                if (WIFEXITED(status))
                        return (WEXITSTATUS(status));
        }
        return (0);
}
#endif

static void
makeargv(void)
{
    char *cp, *cp2, c;
    char **argp = margv;

    margc = 0;
    cp = line;
    if (*cp == '!') {           /* Special case shell escape */
        strcpy(saveline, line); /* save for shell command */
        *argp++ = strdup("!");          /* No room in string to get this */
        margc++;
        cp++;
    }
    while ((c = *cp)) {
        int inquote = 0;
        while (isspace(c))
            c = *++cp;
        if (c == '\0')
            break;
        *argp++ = cp;
        margc += 1;
        for (cp2 = cp; c != '\0'; c = *++cp) {
            if (inquote) {
                if (c == inquote) {
                    inquote = 0;
                    continue;
                }
            } else {
                if (c == '\\') {
                    if ((c = *++cp) == '\0')
                        break;
                } else if (c == '"') {
                    inquote = '"';
                    continue;
                } else if (c == '\'') {
                    inquote = '\'';
                    continue;
                } else if (isspace(c))
                    break;
            }
            *cp2++ = c;
        }
        *cp2 = '\0';
        if (c == '\0')
            break;
        cp++;
    }
    *argp++ = 0;
}

/*
 * Make a character string into a number.
 *
 * Todo:  1.  Could take random integers (12, 0x12, 012, 0b1).
 */

static int
special(char *s)
{
        char c;
        char b;

        switch (*s) {
        case '^':
                b = *++s;
                if (b == '?') {
                    c = b | 0x40;               /* DEL */
                } else {
                    c = b & 0x1f;
                }
                break;
        default:
                c = *s;
                break;
        }
        return c;
}

/*
 * Construct a control character sequence
 * for a special character.
 */
static const char *
control(cc_t c)
{
        static char buf[5];
        /*
         * The only way I could get the Sun 3.5 compiler
         * to shut up about
         *      if ((unsigned int)c >= 0x80)
         * was to assign "c" to an unsigned int variable...
         * Arggg....
         */
        unsigned int uic = (unsigned int)c;

        if (uic == 0x7f)
                return ("^?");
        if (c == (cc_t)_POSIX_VDISABLE) {
                return "off";
        }
        if (uic >= 0x80) {
                buf[0] = '\\';
                buf[1] = ((c>>6)&07) + '0';
                buf[2] = ((c>>3)&07) + '0';
                buf[3] = (c&07) + '0';
                buf[4] = 0;
        } else if (uic >= 0x20) {
                buf[0] = c;
                buf[1] = 0;
        } else {
                buf[0] = '^';
                buf[1] = '@'+c;
                buf[2] = 0;
        }
        return (buf);
}

/*
 *      The following are data structures and routines for
 *      the "send" command.
 *
 */

struct sendlist {
    const char  *name;          /* How user refers to it (case independent) */
    const char  *help;          /* Help information (0 ==> no help) */
    int         needconnect;    /* Need to be connected */
    int         narg;           /* Number of arguments */
    int         (*handler)(char *, ...); /* Routine to perform (for special ops) */
    int         nbyte;          /* Number of bytes to send this command */
    int         what;           /* Character to be sent (<0 ==> special) */
};
\f

static int
        send_esc(void),
        send_help(void),
        send_docmd(char *),
        send_dontcmd(char *),
        send_willcmd(char *),
        send_wontcmd(char *);

static struct sendlist Sendlist[] = {
    { "ao",     "Send Telnet Abort output",     1, 0, NULL, 2, AO },
    { "ayt",    "Send Telnet 'Are You There'",  1, 0, NULL, 2, AYT },
    { "brk",    "Send Telnet Break",            1, 0, NULL, 2, BREAK },
    { "break",  NULL,                           1, 0, NULL, 2, BREAK },
    { "ec",     "Send Telnet Erase Character",  1, 0, NULL, 2, EC },
    { "el",     "Send Telnet Erase Line",       1, 0, NULL, 2, EL },
    { "escape", "Send current escape character",1, 0, (int (*)(char *, ...))send_esc, 1, 0 },
    { "ga",     "Send Telnet 'Go Ahead' sequence", 1, 0, NULL, 2, GA },
    { "ip",     "Send Telnet Interrupt Process",1, 0, NULL, 2, IP },
    { "intp",   NULL,                           1, 0, NULL, 2, IP },
    { "interrupt", NULL,                        1, 0, NULL, 2, IP },
    { "intr",   NULL,                           1, 0, NULL, 2, IP },
    { "nop",    "Send Telnet 'No operation'",   1, 0, NULL, 2, NOP },
    { "eor",    "Send Telnet 'End of Record'",  1, 0, NULL, 2, EOR },
    { "abort",  "Send Telnet 'Abort Process'",  1, 0, NULL, 2, ABORT },
    { "susp",   "Send Telnet 'Suspend Process'",1, 0, NULL, 2, SUSP },
    { "eof",    "Send Telnet End of File Character", 1, 0, NULL, 2, xEOF },
    { "synch",  "Perform Telnet 'Synch operation'", 1, 0, (int (*)(char *, ...))dosynch, 2, 0 },
    { "getstatus", "Send request for STATUS",   1, 0, (int (*)(char *, ...))get_status, 6, 0 },
    { "?",      "Display send options",         0, 0, (int (*)(char *, ...))send_help, 0, 0 },
    { "help",   NULL,                           0, 0, (int (*)(char *, ...))send_help, 0, 0 },
    { "do",     NULL,                           0, 1, (int (*)(char *, ...))send_docmd, 3, 0 },
    { "dont",   NULL,                           0, 1, (int (*)(char *, ...))send_dontcmd, 3, 0 },
    { "will",   NULL,                           0, 1, (int (*)(char *, ...))send_willcmd, 3, 0 },
    { "wont",   NULL,                           0, 1, (int (*)(char *, ...))send_wontcmd, 3, 0 },
    { NULL,     NULL,                           0, 0, NULL, 0, 0 }
};

#define GETSEND(name) ((struct sendlist *) genget(name, (char **) Sendlist, \
                                sizeof(struct sendlist)))

static int
sendcmd(int argc, char *argv[])
{
    int count;          /* how many bytes we are going to need to send */
    int i;
    struct sendlist *s; /* pointer to current command */
    int success = 0;
    int needconnect = 0;

    if (argc < 2) {
        printf("need at least one argument for 'send' command\n");
        printf("'send ?' for help\n");
        return 0;
    }
    /*
     * First, validate all the send arguments.
     * In addition, we see how much space we are going to need, and
     * whether or not we will be doing a "SYNCH" operation (which
     * flushes the network queue).
     */
    count = 0;
    for (i = 1; i < argc; i++) {
        s = GETSEND(argv[i]);
        if (s == 0) {
            printf("Unknown send argument '%s'\n'send ?' for help.\n",
                        argv[i]);
            return 0;
        } else if (Ambiguous((void *)s)) {
            printf("Ambiguous send argument '%s'\n'send ?' for help.\n",
                        argv[i]);
            return 0;
        }
        if (i + s->narg >= argc) {
            fprintf(stderr,
            "Need %d argument%s to 'send %s' command.  'send %s ?' for help.\n",
                s->narg, s->narg == 1 ? "" : "s", s->name, s->name);
            return 0;
        }
        count += s->nbyte;
        if ((void *)s->handler == (void *)send_help) {
            send_help();
            return 0;
        }

        i += s->narg;
        needconnect += s->needconnect;
    }
    if (!connected && needconnect) {
        printf("?Need to be connected first.\n");
        printf("'send ?' for help\n");
        return 0;
    }
    /* Now, do we have enough room? */
    if (NETROOM() < count) {
        printf("There is not enough room in the buffer TO the network\n");
        printf("to process your request.  Nothing will be done.\n");
        printf("('send synch' will throw away most data in the network\n");
        printf("buffer, if this might help.)\n");
        return 0;
    }
    /* OK, they are all OK, now go through again and actually send */
    count = 0;
    for (i = 1; i < argc; i++) {
        if ((s = GETSEND(argv[i])) == 0) {
            fprintf(stderr, "Telnet 'send' error - argument disappeared!\n");
            quit();
            /*NOTREACHED*/
        }
        if (s->handler) {
            count++;
            success += (*s->handler)((s->narg > 0) ? argv[i+1] : 0,
                                  (s->narg > 1) ? argv[i+2] : 0);
            i += s->narg;
        } else {
            NET2ADD(IAC, s->what);
            printoption("SENT", IAC, s->what);
        }
    }
    return (count == success);
}

static int
send_esc(void)
{
    NETADD(escape);
    return 1;
}

static int
send_docmd(char *name)
{
    return(send_tncmd(send_do, "do", name));
}

static int
send_dontcmd(name)
    char *name;
{
    return(send_tncmd(send_dont, "dont", name));
}

static int
send_willcmd(char *name)
{
    return(send_tncmd(send_will, "will", name));
}

static int
send_wontcmd(char *name)
{
    return(send_tncmd(send_wont, "wont", name));
}

static int
send_tncmd(void (*func)(int, int), const char *cmd, char *name)
{
    char **cpp;
    extern char *telopts[];
    int val = 0;

    if (isprefix(name, "help") || isprefix(name, "?")) {
        int col, len;

        printf("Usage: send %s <value|option>\n", cmd);
        printf("\"value\" must be from 0 to 255\n");
        printf("Valid options are:\n\t");

        col = 8;
        for (cpp = telopts; *cpp; cpp++) {
            len = strlen(*cpp) + 3;
            if (col + len > 65) {
                printf("\n\t");
                col = 8;
            }
            printf(" \"%s\"", *cpp);
            col += len;
        }
        printf("\n");
        return 0;
    }
    cpp = (char **)genget(name, telopts, sizeof(char *));
    if (Ambiguous(cpp)) {
        fprintf(stderr,"'%s': ambiguous argument ('send %s ?' for help).\n",
                                        name, cmd);
        return 0;
    }
    if (cpp) {
        val = cpp - telopts;
    } else {
        char *cp = name;

        while (*cp >= '0' && *cp <= '9') {
            val *= 10;
            val += *cp - '0';
            cp++;
        }
        if (*cp != 0) {
            fprintf(stderr, "'%s': unknown argument ('send %s ?' for help).\n",
                                        name, cmd);
            return 0;
        } else if (val < 0 || val > 255) {
            fprintf(stderr, "'%s': bad value ('send %s ?' for help).\n",
                                        name, cmd);
            return 0;
        }
    }
    if (!connected) {
        printf("?Need to be connected first.\n");
        return 0;
    }
    (*func)(val, 1);
    return 1;
}

static int
send_help(void)
{
    struct sendlist *s; /* pointer to current command */
    for (s = Sendlist; s->name; s++) {
        if (s->help)
            printf("%-15s %s\n", s->name, s->help);
    }
    return(0);
}
\f
/*
 * The following are the routines and data structures referred
 * to by the arguments to the "toggle" command.
 */

static int
lclchars(void)
{
    donelclchars = 1;
    return 1;
}

static int
togdebug(void)
{
#ifndef NOT43
    if (net > 0 &&
        (SetSockOpt(net, SOL_SOCKET, SO_DEBUG, debug)) < 0) {
            perror("setsockopt (SO_DEBUG)");
    }
#else   /* NOT43 */
    if (debug) {
        if (net > 0 && SetSockOpt(net, SOL_SOCKET, SO_DEBUG, 1) < 0)
            perror("setsockopt (SO_DEBUG)");
    } else
        printf("Cannot turn off socket debugging\n");
#endif  /* NOT43 */
    return 1;
}


static int
togcrlf(void)
{
    if (crlf) {
        printf("Will send carriage returns as telnet <CR><LF>.\n");
    } else {
        printf("Will send carriage returns as telnet <CR><NUL>.\n");
    }
    return 1;
}

int binmode;

static int
togbinary(int val)
{
    donebinarytoggle = 1;

    if (val >= 0) {
        binmode = val;
    } else {
        if (my_want_state_is_will(TELOPT_BINARY) &&
                                my_want_state_is_do(TELOPT_BINARY)) {
            binmode = 1;
        } else if (my_want_state_is_wont(TELOPT_BINARY) &&
                                my_want_state_is_dont(TELOPT_BINARY)) {
            binmode = 0;
        }
        val = binmode ? 0 : 1;
    }

    if (val == 1) {
        if (my_want_state_is_will(TELOPT_BINARY) &&
                                        my_want_state_is_do(TELOPT_BINARY)) {
            printf("Already operating in binary mode with remote host.\n");
        } else {
            printf("Negotiating binary mode with remote host.\n");
            tel_enter_binary(3);
        }
    } else {
        if (my_want_state_is_wont(TELOPT_BINARY) &&
                                        my_want_state_is_dont(TELOPT_BINARY)) {
            printf("Already in network ascii mode with remote host.\n");
        } else {
            printf("Negotiating network ascii mode with remote host.\n");
            tel_leave_binary(3);
        }
    }
    return 1;
}

static int
togrbinary(int val)
{
    donebinarytoggle = 1;

    if (val == -1)
        val = my_want_state_is_do(TELOPT_BINARY) ? 0 : 1;

    if (val == 1) {
        if (my_want_state_is_do(TELOPT_BINARY)) {
            printf("Already receiving in binary mode.\n");
        } else {
            printf("Negotiating binary mode on input.\n");
            tel_enter_binary(1);
        }
    } else {
        if (my_want_state_is_dont(TELOPT_BINARY)) {
            printf("Already receiving in network ascii mode.\n");
        } else {
            printf("Negotiating network ascii mode on input.\n");
            tel_leave_binary(1);
        }
    }
    return 1;
}

static int
togxbinary(int val)
{
    donebinarytoggle = 1;

    if (val == -1)
        val = my_want_state_is_will(TELOPT_BINARY) ? 0 : 1;

    if (val == 1) {
        if (my_want_state_is_will(TELOPT_BINARY)) {
            printf("Already transmitting in binary mode.\n");
        } else {
            printf("Negotiating binary mode on output.\n");
            tel_enter_binary(2);
        }
    } else {
        if (my_want_state_is_wont(TELOPT_BINARY)) {
            printf("Already transmitting in network ascii mode.\n");
        } else {
            printf("Negotiating network ascii mode on output.\n");
            tel_leave_binary(2);
        }
    }
    return 1;
}

struct togglelist {
    const char  *name;          /* name of toggle */
    const char  *help;          /* help message */
    int         (*handler)(int); /* routine to do actual setting */
    int         *variable;
    const char  *actionexplanation;
};

static struct togglelist Togglelist[] = {
    { "autoflush",
        "flushing of output when sending interrupt characters",
            0,
                &autoflush,
                    "flush output when sending interrupt characters" },
    { "autosynch",
        "automatic sending of interrupt characters in urgent mode",
            0,
                &autosynch,
                    "send interrupt characters in urgent mode" },
#ifdef  AUTHENTICATION
    { "autologin",
        "automatic sending of login and/or authentication info",
            0,
                &autologin,
                    "send login name and/or authentication information" },
    { "authdebug",
        "Toggle authentication debugging",
            auth_togdebug,
                0,
                     "print authentication debugging information" },
#endif
#ifdef  ENCRYPTION
    { "autoencrypt",
        "automatic encryption of data stream",
            EncryptAutoEnc,
                0,
                    "automatically encrypt output" },
    { "autodecrypt",
        "automatic decryption of data stream",
            EncryptAutoDec,
                0,
                    "automatically decrypt input" },
    { "verbose_encrypt",
        "Toggle verbose encryption output",
            EncryptVerbose,
                0,
                    "print verbose encryption output" },
    { "encdebug",
        "Toggle encryption debugging",
            EncryptDebug,
                0,
                    "print encryption debugging information" },
#endif  /* ENCRYPTION */
    { "skiprc",
        "don't read ~/.telnetrc file",
            0,
                &skiprc,
                    "skip reading of ~/.telnetrc file" },
    { "binary",
        "sending and receiving of binary data",
            togbinary,
                0,
                    0 },
    { "inbinary",
        "receiving of binary data",
            togrbinary,
                0,
                    0 },
    { "outbinary",
        "sending of binary data",
            togxbinary,
                0,
                    0 },
    { "crlf",
        "sending carriage returns as telnet <CR><LF>",
            (int (*)(int))togcrlf,
                &crlf,
                    0 },
    { "crmod",
        "mapping of received carriage returns",
            0,
                &crmod,
                    "map carriage return on output" },
    { "localchars",
        "local recognition of certain control characters",
            (int (*)(int))lclchars,
                &localchars,
                    "recognize certain control characters" },
    { " ", "", NULL, NULL, NULL },              /* empty line */
    { "debug",
        "debugging",
            (int (*)(int))togdebug,
                &debug,
                    "turn on socket level debugging" },
    { "netdata",
        "printing of hexadecimal network data (debugging)",
            0,
                &netdata,
                    "print hexadecimal representation of network traffic" },
    { "prettydump",
        "output of \"netdata\" to user readable format (debugging)",
            0,
                &prettydump,
                    "print user readable output for \"netdata\"" },
    { "options",
        "viewing of options processing (debugging)",
            0,
                &showoptions,
                    "show option processing" },
    { "termdata",
        "(debugging) toggle printing of hexadecimal terminal data",
            0,
                &termdata,
                    "print hexadecimal representation of terminal traffic" },
    { "?",
        NULL,
            (int (*)(int))togglehelp,
                NULL,
                    NULL },
    { NULL, NULL, NULL, NULL, NULL },
    { "help",
        NULL,
            (int (*)(int))togglehelp,
                NULL,
                    NULL },
    { NULL, NULL, NULL, NULL, NULL }
};

static int
togglehelp(void)
{
    struct togglelist *c;

    for (c = Togglelist; c->name; c++) {
        if (c->help) {
            if (*c->help)
                printf("%-15s toggle %s\n", c->name, c->help);
            else
                printf("\n");
        }
    }
    printf("\n");
    printf("%-15s %s\n", "?", "display help information");
    return 0;
}

static void
settogglehelp(int set)
{
    struct togglelist *c;

    for (c = Togglelist; c->name; c++) {
        if (c->help) {
            if (*c->help)
                printf("%-15s %s %s\n", c->name, set ? "enable" : "disable",
                                                c->help);
            else
                printf("\n");
        }
    }
}

#define GETTOGGLE(name) (struct togglelist *) \
                genget(name, (char **) Togglelist, sizeof(struct togglelist))

static int
toggle(int argc, char *argv[])
{
    int retval = 1;
    char *name;
    struct togglelist *c;

    if (argc < 2) {
        fprintf(stderr,
            "Need an argument to 'toggle' command.  'toggle ?' for help.\n");
        return 0;
    }
    argc--;
    argv++;
    while (argc--) {
        name = *argv++;
        c = GETTOGGLE(name);
        if (Ambiguous((void *)c)) {
            fprintf(stderr, "'%s': ambiguous argument ('toggle ?' for help).\n",
                                        name);
            return 0;
        } else if (c == 0) {
            fprintf(stderr, "'%s': unknown argument ('toggle ?' for help).\n",
                                        name);
            return 0;
        } else {
            if (c->variable) {
                *c->variable = !*c->variable;           /* invert it */
                if (c->actionexplanation) {
                    printf("%s %s.\n", *c->variable? "Will" : "Won't",
                                                        c->actionexplanation);
                }
            }
            if (c->handler) {
                retval &= (*c->handler)(-1);
            }
        }
    }
    return retval;
}
\f
/*
 * The following perform the "set" command.
 */

#ifdef  USE_TERMIO
struct termio new_tc = { 0, 0, 0, 0, {}, 0, 0 };
#endif

struct setlist {
    const char *name;                   /* name */
    const char *help;                   /* help information */
    void (*handler)(char *);
    cc_t *charp;                        /* where it is located at */
};

static struct setlist Setlist[] = {
#ifdef  KLUDGELINEMODE
    { "echo",   "character to toggle local echoing on/off", NULL, &echoc },
#endif
    { "escape", "character to escape back to telnet command mode", NULL, &escape },
    { "rlogin", "rlogin escape character", 0, &rlogin },
    { "tracefile", "file to write trace information to", SetNetTrace, (cc_t *)NetTraceFile},
    { " ", "", NULL, NULL },
    { " ", "The following need 'localchars' to be toggled true", NULL, NULL },
    { "flushoutput", "character to cause an Abort Output", NULL, termFlushCharp },
    { "interrupt", "character to cause an Interrupt Process", NULL, termIntCharp },
    { "quit",   "character to cause an Abort process", NULL, termQuitCharp },
    { "eof",    "character to cause an EOF ", NULL, termEofCharp },
    { " ", "", NULL, NULL },
    { " ", "The following are for local editing in linemode", NULL, NULL },
    { "erase",  "character to use to erase a character", NULL, termEraseCharp },
    { "kill",   "character to use to erase a line", NULL, termKillCharp },
    { "lnext",  "character to use for literal next", NULL, termLiteralNextCharp },
    { "susp",   "character to cause a Suspend Process", NULL, termSuspCharp },
    { "reprint", "character to use for line reprint", NULL, termRprntCharp },
    { "worderase", "character to use to erase a word", NULL, termWerasCharp },
    { "start",  "character to use for XON", NULL, termStartCharp },
    { "stop",   "character to use for XOFF", NULL, termStopCharp },
    { "forw1",  "alternate end of line character", NULL, termForw1Charp },
    { "forw2",  "alternate end of line character", NULL, termForw2Charp },
    { "ayt",    "alternate AYT character", NULL, termAytCharp },
    { NULL, NULL, NULL, NULL }
};

static struct setlist *
getset(char *name)
{
    return (struct setlist *)
                genget(name, (char **) Setlist, sizeof(struct setlist));
}

void
set_escape_char(char *s)
{
        if (rlogin != _POSIX_VDISABLE) {
                rlogin = (s && *s) ? special(s) : _POSIX_VDISABLE;
                printf("Telnet rlogin escape character is '%s'.\n",
                                        control(rlogin));
        } else {
                escape = (s && *s) ? special(s) : _POSIX_VDISABLE;
                printf("Telnet escape character is '%s'.\n", control(escape));
        }
}

static int
setcmd(int argc, char *argv[])
{
    int value;
    struct setlist *ct;
    struct togglelist *c;

    if (argc < 2 || argc > 3) {
        printf("Format is 'set Name Value'\n'set ?' for help.\n");
        return 0;
    }
    if ((argc == 2) && (isprefix(argv[1], "?") || isprefix(argv[1], "help"))) {
        for (ct = Setlist; ct->name; ct++)
            printf("%-15s %s\n", ct->name, ct->help);
        printf("\n");
        settogglehelp(1);
        printf("%-15s %s\n", "?", "display help information");
        return 0;
    }

    ct = getset(argv[1]);
    if (ct == 0) {
        c = GETTOGGLE(argv[1]);
        if (c == 0) {
            fprintf(stderr, "'%s': unknown argument ('set ?' for help).\n",
                        argv[1]);
            return 0;
        } else if (Ambiguous((void *)c)) {
            fprintf(stderr, "'%s': ambiguous argument ('set ?' for help).\n",
                        argv[1]);
            return 0;
        }
        if (c->variable) {
            if ((argc == 2) || (strcmp("on", argv[2]) == 0))
                *c->variable = 1;
            else if (strcmp("off", argv[2]) == 0)
                *c->variable = 0;
            else {
                printf("Format is 'set togglename [on|off]'\n'set ?' for help.\n");
                return 0;
            }
            if (c->actionexplanation) {
                printf("%s %s.\n", *c->variable? "Will" : "Won't",
                                                        c->actionexplanation);
            }
        }
        if (c->handler)
            (*c->handler)(1);
    } else if (argc != 3) {
        printf("Format is 'set Name Value'\n'set ?' for help.\n");
        return 0;
    } else if (Ambiguous((void *)ct)) {
        fprintf(stderr, "'%s': ambiguous argument ('set ?' for help).\n",
                        argv[1]);
        return 0;
    } else if (ct->handler) {
        (*ct->handler)(argv[2]);
        printf("%s set to \"%s\".\n", ct->name, (char *)ct->charp);
    } else {
        if (strcmp("off", argv[2])) {
            value = special(argv[2]);
        } else {
            value = _POSIX_VDISABLE;
        }
        *(ct->charp) = (cc_t)value;
        printf("%s character is '%s'.\n", ct->name, control(*(ct->charp)));
    }
    slc_check();
    return 1;
}

static int
unsetcmd(int argc, char *argv[])
{
    struct setlist *ct;
    struct togglelist *c;
    char *name;

    if (argc < 2) {
        fprintf(stderr,
            "Need an argument to 'unset' command.  'unset ?' for help.\n");
        return 0;
    }
    if (isprefix(argv[1], "?") || isprefix(argv[1], "help")) {
        for (ct = Setlist; ct->name; ct++)
            printf("%-15s %s\n", ct->name, ct->help);
        printf("\n");
        settogglehelp(0);
        printf("%-15s %s\n", "?", "display help information");
        return 0;
    }

    argc--;
    argv++;
    while (argc--) {
        name = *argv++;
        ct = getset(name);
        if (ct == 0) {
            c = GETTOGGLE(name);
            if (c == 0) {
                fprintf(stderr, "'%s': unknown argument ('unset ?' for help).\n",
                        name);
                return 0;
            } else if (Ambiguous((void *)c)) {
                fprintf(stderr, "'%s': ambiguous argument ('unset ?' for help).\n",
                        name);
                return 0;
            }
            if (c->variable) {
                *c->variable = 0;
                if (c->actionexplanation) {
                    printf("%s %s.\n", *c->variable? "Will" : "Won't",
                                                        c->actionexplanation);
                }
            }
            if (c->handler)
                (*c->handler)(0);
        } else if (Ambiguous((void *)ct)) {
            fprintf(stderr, "'%s': ambiguous argument ('unset ?' for help).\n",
                        name);
            return 0;
        } else if (ct->handler) {
            (*ct->handler)(0);
            printf("%s reset to \"%s\".\n", ct->name, (char *)ct->charp);
        } else {
            *(ct->charp) = _POSIX_VDISABLE;
            printf("%s character is '%s'.\n", ct->name, control(*(ct->charp)));
        }
    }
    return 1;
}
\f
/*
 * The following are the data structures and routines for the
 * 'mode' command.
 */
#ifdef  KLUDGELINEMODE
extern int kludgelinemode;

static int
dokludgemode(void)
{
    kludgelinemode = 1;
    send_wont(TELOPT_LINEMODE, 1);
    send_dont(TELOPT_SGA, 1);
    send_dont(TELOPT_ECHO, 1);
    return 1;
}
#endif

static int
dolinemode(void)
{
#ifdef  KLUDGELINEMODE
    if (kludgelinemode)
        send_dont(TELOPT_SGA, 1);
#endif
    send_will(TELOPT_LINEMODE, 1);
    send_dont(TELOPT_ECHO, 1);
    return 1;
}

static int
docharmode(void)
{
#ifdef  KLUDGELINEMODE
    if (kludgelinemode)
        send_do(TELOPT_SGA, 1);
    else
#endif
    send_wont(TELOPT_LINEMODE, 1);
    send_do(TELOPT_ECHO, 1);
    return 1;
}

static int
dolmmode(int bit, int on)
{
    unsigned char c;
    extern int linemode;

    if (my_want_state_is_wont(TELOPT_LINEMODE)) {
        printf("?Need to have LINEMODE option enabled first.\n");
        printf("'mode ?' for help.\n");
        return 0;
    }

    if (on)
        c = (linemode | bit);
    else
        c = (linemode & ~bit);
    lm_mode(&c, 1, 1);
    return 1;
}

static int
setmod(int bit)
{
    return dolmmode(bit, 1);
}

static int
clearmode(int bit)
{
    return dolmmode(bit, 0);
}

struct modelist {
        const char      *name;  /* command name */
        const char      *help;  /* help string */
        int     (*handler)(int);/* routine which executes command */
        int     needconnect;    /* Do we need to be connected to execute? */
        int     arg1;
};

static struct modelist ModeList[] = {
    { "character", "Disable LINEMODE option",   (int (*)(int))docharmode, 1, 0 },
#ifdef  KLUDGELINEMODE
    { "",       "(or disable obsolete line-by-line mode)", NULL, 0, 0 },
#endif
    { "line",   "Enable LINEMODE option",       (int (*)(int))dolinemode, 1, 0 },
#ifdef  KLUDGELINEMODE
    { "",       "(or enable obsolete line-by-line mode)", NULL, 0, 0 },
#endif
    { "", "", NULL, 0, 0 },
    { "",       "These require the LINEMODE option to be enabled", NULL, 0, 0 },
    { "isig",   "Enable signal trapping",       setmod, 1, MODE_TRAPSIG },
    { "+isig",  0,                              setmod, 1, MODE_TRAPSIG },
    { "-isig",  "Disable signal trapping",      clearmode, 1, MODE_TRAPSIG },
    { "edit",   "Enable character editing",     setmod, 1, MODE_EDIT },
    { "+edit",  0,                              setmod, 1, MODE_EDIT },
    { "-edit",  "Disable character editing",    clearmode, 1, MODE_EDIT },
    { "softtabs", "Enable tab expansion",       setmod, 1, MODE_SOFT_TAB },
    { "+softtabs", 0,                           setmod, 1, MODE_SOFT_TAB },
    { "-softtabs", "Disable character editing", clearmode, 1, MODE_SOFT_TAB },
    { "litecho", "Enable literal character echo", setmod, 1, MODE_LIT_ECHO },
    { "+litecho", 0,                            setmod, 1, MODE_LIT_ECHO },
    { "-litecho", "Disable literal character echo", clearmode, 1, MODE_LIT_ECHO },
    { "help",   0,                              (int (*)(int))modehelp, 0, 0 },
#ifdef  KLUDGELINEMODE
    { "kludgeline", 0,                          (int (*)(int))dokludgemode, 1, 0 },
#endif
    { "", "", NULL, 0, 0 },
    { "?",      "Print help information",       (int (*)(int))modehelp, 0, 0 },
    { NULL, NULL, NULL, 0, 0 },
};


static int
modehelp(void)
{
    struct modelist *mt;

    printf("format is:  'mode Mode', where 'Mode' is one of:\n\n");
    for (mt = ModeList; mt->name; mt++) {
        if (mt->help) {
            if (*mt->help)
                printf("%-15s %s\n", mt->name, mt->help);
            else
                printf("\n");
        }
    }
    return 0;
}

#define GETMODECMD(name) (struct modelist *) \
                genget(name, (char **) ModeList, sizeof(struct modelist))

static int
modecmd(int argc, char *argv[])
{
    struct modelist *mt;

    if (argc != 2) {
        printf("'mode' command requires an argument\n");
        printf("'mode ?' for help.\n");
    } else if ((mt = GETMODECMD(argv[1])) == 0) {
        fprintf(stderr, "Unknown mode '%s' ('mode ?' for help).\n", argv[1]);
    } else if (Ambiguous((void *)mt)) {
        fprintf(stderr, "Ambiguous mode '%s' ('mode ?' for help).\n", argv[1]);
    } else if (mt->needconnect && !connected) {
        printf("?Need to be connected first.\n");
        printf("'mode ?' for help.\n");
    } else if (mt->handler) {
        return (*mt->handler)(mt->arg1);
    }
    return 0;
}
\f
/*
 * The following data structures and routines implement the
 * "display" command.
 */

static int
display(int argc, char *argv[])
{
    struct togglelist *tl;
    struct setlist *sl;

#define dotog(tl)       if (tl->variable && tl->actionexplanation) { \
                            if (*tl->variable) { \
                                printf("will"); \
                            } else { \
                                printf("won't"); \
                            } \
                            printf(" %s.\n", tl->actionexplanation); \
                        }

#define doset(sl)   if (sl->name && *sl->name != ' ') { \
                        if (sl->handler == 0) \
                            printf("%-15s [%s]\n", sl->name, control(*sl->charp)); \
                        else \
                            printf("%-15s \"%s\"\n", sl->name, (char *)sl->charp); \
                    }

    if (argc == 1) {
        for (tl = Togglelist; tl->name; tl++) {
            dotog(tl);
        }
        printf("\n");
        for (sl = Setlist; sl->name; sl++) {
            doset(sl);
        }
    } else {
        int i;

        for (i = 1; i < argc; i++) {
            sl = getset(argv[i]);
            tl = GETTOGGLE(argv[i]);
            if (Ambiguous((void *)sl) || Ambiguous((void *)tl)) {
                printf("?Ambiguous argument '%s'.\n", argv[i]);
                return 0;
            } else if (!sl && !tl) {
                printf("?Unknown argument '%s'.\n", argv[i]);
                return 0;
            } else {
                if (tl) {
                    dotog(tl);
                }
                if (sl) {
                    doset(sl);
                }
            }
        }
    }
/*@*/optionstatus();
#ifdef  ENCRYPTION
    EncryptStatus();
#endif  /* ENCRYPTION */
    return 1;
#undef  doset
#undef  dotog
}
\f
/*
 * The following are the data structures, and many of the routines,
 * relating to command processing.
 */

/*
 * Set the escape character.
 */
static int
setescape(int argc, char *argv[])
{
        char *arg;
        char buf[50];

        printf(
            "Deprecated usage - please use 'set escape%s%s' in the future.\n",
                                (argc > 2)? " ":"", (argc > 2)? argv[1]: "");
        if (argc > 2)
                arg = argv[1];
        else {
                printf("new escape character: ");
                (void) fgets(buf, sizeof(buf), stdin);
                arg = buf;
        }
        if (arg[0] != '\0')
                escape = arg[0];
        (void) fflush(stdout);
        return 1;
}

static int
togcrmod(void)
{
    crmod = !crmod;
    printf("Deprecated usage - please use 'toggle crmod' in the future.\n");
    printf("%s map carriage return on output.\n", crmod ? "Will" : "Won't");
    (void) fflush(stdout);
    return 1;
}

static int
suspend(void)
{
#ifdef  SIGTSTP
    setcommandmode();
    {
        long oldrows, oldcols, newrows, newcols, err_;

        err_ = (TerminalWindowSize(&oldrows, &oldcols) == 0) ? 1 : 0;
        (void) kill(0, SIGTSTP);
        /*
         * If we didn't get the window size before the SUSPEND, but we
         * can get them now (?), then send the NAWS to make sure that
         * we are set up for the right window size.
         */
        if (TerminalWindowSize(&newrows, &newcols) && connected &&
            (err_ || ((oldrows != newrows) || (oldcols != newcols)))) {
                sendnaws();
        }
    }
    /* reget parameters in case they were changed */
    TerminalSaveState();
    setconnmode(0);
#else
    printf("Suspend is not supported.  Try the '!' command instead\n");
#endif
    return 1;
}

static int
shell(int argc, char *argv[] __unused)
{
    long oldrows, oldcols, newrows, newcols, err_;

    setcommandmode();

    err_ = (TerminalWindowSize(&oldrows, &oldcols) == 0) ? 1 : 0;
    switch(vfork()) {
    case -1:
        perror("Fork failed\n");
        break;

    case 0:
        {
            /*
             * Fire up the shell in the child.
             */
            const char *shellp, *shellname;

            shellp = getenv("SHELL");
            if (shellp == NULL)
                shellp = "/bin/sh";
            if ((shellname = strrchr(shellp, '/')) == 0)
                shellname = shellp;
            else
                shellname++;
            if (argc > 1)
                execl(shellp, shellname, "-c", &saveline[1], (char *)0);
            else
                execl(shellp, shellname, (char *)0);
            perror("Execl");
            _exit(1);
        }
    default:
            (void)wait((int *)0);       /* Wait for the shell to complete */

            if (TerminalWindowSize(&newrows, &newcols) && connected &&
                (err_ || ((oldrows != newrows) || (oldcols != newcols)))) {
                    sendnaws();
            }
            break;
    }
    return 1;
}

static int
bye(int argc, char *argv[])
{
    extern int resettermname;

    if (connected) {
        (void) shutdown(net, 2);
        printf("Connection closed.\n");
        (void) NetClose(net);
        connected = 0;
        resettermname = 1;
#ifdef  AUTHENTICATION
#ifdef  ENCRYPTION
        auth_encrypt_connect(connected);
#endif
#endif
        /* reset options */
        tninit();
    }
    if ((argc != 2) || (strcmp(argv[1], "fromquit") != 0)) {
        longjmp(toplevel, 1);
        /* NOTREACHED */
    }
    return 1;                   /* Keep lint, etc., happy */
}

void
quit(void)
{
        (void) call(bye, "bye", "fromquit", 0);
        Exit(0);
}

static int
logout(void)
{
        send_do(TELOPT_LOGOUT, 1);
        (void) netflush();
        return 1;
}

\f
/*
 * The SLC command.
 */

struct slclist {
        const char      *name;
        const char      *help;
        void    (*handler)(int);
        int     arg;
};

static void slc_help(void);

struct slclist SlcList[] = {
    { "export", "Use local special character definitions",
                                                (void (*)(int))slc_mode_export, 0 },
    { "import", "Use remote special character definitions",
                                                slc_mode_import,        1 },
    { "check",  "Verify remote special character definitions",
                                                slc_mode_import,        0 },
    { "help",   NULL,                           (void (*)(int))slc_help,                0 },
    { "?",      "Print help information",       (void (*)(int))slc_help,                0 },
    { NULL, NULL, NULL, 0 },
};

static void
slc_help(void)
{
    struct slclist *c;

    for (c = SlcList; c->name; c++) {
        if (c->help) {
            if (*c->help)
                printf("%-15s %s\n", c->name, c->help);
            else
                printf("\n");
        }
    }
}

static struct slclist *
getslc(char *name)
{
    return (struct slclist *)
                genget(name, (char **) SlcList, sizeof(struct slclist));
}

static int
slccmd(int argc, char *argv[])
{
    struct slclist *c;

    if (argc != 2) {
        fprintf(stderr,
            "Need an argument to 'slc' command.  'slc ?' for help.\n");
        return 0;
    }
    c = getslc(argv[1]);
    if (c == 0) {
        fprintf(stderr, "'%s': unknown argument ('slc ?' for help).\n",
                                argv[1]);
        return 0;
    }
    if (Ambiguous((void *)c)) {
        fprintf(stderr, "'%s': ambiguous argument ('slc ?' for help).\n",
                                argv[1]);
        return 0;
    }
    (*c->handler)(c->arg);
    slcstate();
    return 1;
}
\f
/*
 * The ENVIRON command.
 */

struct envlist {
        const char      *name;
        const char      *help;
        void    (*handler)(unsigned char *, unsigned char *);
        int     narg;
};

extern struct env_lst *
        env_define(const unsigned char *, unsigned char *);
extern void
        env_undefine(unsigned char *),
        env_export(const unsigned char *),
        env_unexport(const unsigned char *),
        env_send(unsigned char *),
#if defined(OLD_ENVIRON) && defined(ENV_HACK)
        env_varval(unsigned char *),
#endif
        env_list(void);
static void
        env_help(void);

struct envlist EnvList[] = {
    { "define", "Define an environment variable",
                                                (void (*)(unsigned char *, unsigned char *))env_define, 2 },
    { "undefine", "Undefine an environment variable",
                                                (void (*)(unsigned char *, unsigned char *))env_undefine,       1 },
    { "export", "Mark an environment variable for automatic export",
                                                (void (*)(unsigned char *, unsigned char *))env_export, 1 },
    { "unexport", "Don't mark an environment variable for automatic export",
                                                (void (*)(unsigned char *, unsigned char *))env_unexport,       1 },
    { "send",   "Send an environment variable", (void (*)(unsigned char *, unsigned char *))env_send,   1 },
    { "list",   "List the current environment variables",
                                                (void (*)(unsigned char *, unsigned char *))env_list,   0 },
#if defined(OLD_ENVIRON) && defined(ENV_HACK)
    { "varval", "Reverse VAR and VALUE (auto, right, wrong, status)",
                                                (void (*)(unsigned char *, unsigned char *))env_varval,    1 },
#endif
    { "help",   NULL,                           (void (*)(unsigned char *, unsigned char *))env_help,           0 },
    { "?",      "Print help information",       (void (*)(unsigned char *, unsigned char *))env_help,           0 },
    { NULL, NULL, NULL, 0 },
};

static void
env_help(void)
{
    struct envlist *c;

    for (c = EnvList; c->name; c++) {
        if (c->help) {
            if (*c->help)
                printf("%-15s %s\n", c->name, c->help);
            else
                printf("\n");
        }
    }
}

static struct envlist *
getenvcmd(char *name)
{
    return (struct envlist *)
                genget(name, (char **) EnvList, sizeof(struct envlist));
}

static int
env_cmd(int argc, char *argv[])
{
    struct envlist *c;

    if (argc < 2) {
        fprintf(stderr,
            "Need an argument to 'environ' command.  'environ ?' for help.\n");
        return 0;
    }
    c = getenvcmd(argv[1]);
    if (c == 0) {
        fprintf(stderr, "'%s': unknown argument ('environ ?' for help).\n",
                                argv[1]);
        return 0;
    }
    if (Ambiguous((void *)c)) {
        fprintf(stderr, "'%s': ambiguous argument ('environ ?' for help).\n",
                                argv[1]);
        return 0;
    }
    if (c->narg + 2 != argc && strcasecmp(argv[1],"define")==0 && c->narg + 1 != argc) {
        fprintf(stderr,
            "Need %s%d argument%s to 'environ %s' command.  'environ ?' for help.\n",
                c->narg < argc + 2 ? "only " : "",
                c->narg, c->narg == 1 ? "" : "s", c->name);
        return 0;
    }
    (*c->handler)(argv[2], argv[3]);
    return 1;
}

struct env_lst {
        struct env_lst *next;   /* pointer to next structure */
        struct env_lst *prev;   /* pointer to previous structure */
        unsigned char *var;     /* pointer to variable name */
        unsigned char *value;   /* pointer to variable value */
        int export;             /* 1 -> export with default list of variables */
        int welldefined;        /* A well defined variable */
};

struct env_lst envlisthead;

static struct env_lst *
env_find(const unsigned char *var)
{
        struct env_lst *ep;

        for (ep = envlisthead.next; ep; ep = ep->next) {
                if (strcmp(ep->var, var) == 0)
                        return(ep);
        }
        return(NULL);
}

void
env_init(void)
{
        char *ev;
        struct env_lst *ep;
        int i;

        const char *safe_vars[]=
          {"USER", "PRINTER", "DISPLAY", "TERM", "COLUMNS", "LINES"};
        
        for(i=0;i<sizeof(safe_vars)/sizeof(const char *);i++) {
            if(ev=getenv(safe_vars[i])) {
              ep=env_define((unsigned char *)safe_vars[i],(unsigned char *)ev);
                ep->export=0;
            }
        }

        /*
         * Special case for DISPLAY variable.  If it is ":0.0" or
         * "unix:0.0", we have to get rid of "unix" and insert our
         * hostname.
         */
        if ((ep = env_find("DISPLAY"))
            && ((*ep->value == ':')
                || (strncmp((char *)ep->value, "unix:", 5) == 0))) {
                char hbuf[256+1];
                char *cp, *cp2 = strchr((char *)ep->value, ':');

                gethostname(hbuf, 256);
                hbuf[256] = '\0';
                cp = (char *)malloc(strlen(hbuf) + strlen(cp2) + 1);
                sprintf((char *)cp, "%s%s", hbuf, cp2);
                free(ep->value);
                ep->value = (unsigned char *)cp;
        }
        /*
         * If USER is not defined, but LOGNAME is, then add
         * USER with the value from LOGNAME.  By default, we
         * don't export the USER variable.
         */
        if ((env_find("USER") == NULL) && (ep = env_find("LOGNAME"))) {
                env_define("USER", ep->value);
                env_unexport("USER");
        }
        env_export("DISPLAY");
        env_export("PRINTER");
}

struct env_lst *
env_define(const unsigned char *var, unsigned char *value)
{
        char *ev;
        struct env_lst *ep;

        if ((ep = env_find(var))) {
                if (ep->var)
                        free(ep->var);
                if (ep->value)
                        free(ep->value);
        } else {
                ep = (struct env_lst *)malloc(sizeof(struct env_lst));
                ep->next = envlisthead.next;
                envlisthead.next = ep;
                ep->prev = &envlisthead;
                if (ep->next)
                        ep->next->prev = ep;
        }

        ep->welldefined = opt_welldefined((const char *)var);
        ep->export = 1;
        ep->var = (unsigned char *)strdup((const char *)var);

        if(value) 
                  ep->value = (unsigned char *)strdup((const char *)value);
        else if(ev=getenv((const char *)var))
                  ep->value = (unsigned char *)strdup(ev);
        else      ep->value = (unsigned char *)strdup("");
        return(ep);
}

void
env_undefine(unsigned char *var)
{
        struct env_lst *ep;

        if ((ep = env_find(var))) {
                ep->prev->next = ep->next;
                if (ep->next)
                        ep->next->prev = ep->prev;
                if (ep->var)
                        free(ep->var);
                if (ep->value)
                        free(ep->value);
                free(ep);
        }
}

void
env_export(const unsigned char *var)
{
        struct env_lst *ep;

        if ((ep = env_find(var)))
                ep->export = 1;
}

void
env_unexport(const unsigned char *var)
{
        struct env_lst *ep;

        if ((ep = env_find(var)))
                ep->export = 0;
}

void
env_send(unsigned char *var)
{
        struct env_lst *ep;

        if (my_state_is_wont(TELOPT_NEW_ENVIRON)
#ifdef  OLD_ENVIRON
           && my_state_is_wont(TELOPT_OLD_ENVIRON)
#endif
                ) {
                fprintf(stderr,
                    "Cannot send '%s': Telnet ENVIRON option not enabled\n",
                                                                        var);
                return;
        }
        ep = env_find(var);
        if (ep == 0) {
                fprintf(stderr, "Cannot send '%s': variable not defined\n",
                                                                        var);
                return;
        }
        env_opt_start_info();
        env_opt_add(ep->var);
        env_opt_end(0);
}

void
env_list(void)
{
        struct env_lst *ep;

        for (ep = envlisthead.next; ep; ep = ep->next) {
                printf("%c %-20s %s\n", ep->export ? '*' : ' ',
                                        ep->var, ep->value);
        }
}

unsigned char *
env_default(int init, int welldefined)
{
        static struct env_lst *nep = NULL;

        if (init) {
                nep = &envlisthead;
                return(NULL);
        }
        if (nep) {
                while ((nep = nep->next)) {
                        if (nep->export && (nep->welldefined == welldefined))
                                return(nep->var);
                }
        }
        return(NULL);
}

unsigned char *
env_getvalue(const unsigned char *var)
{
        struct env_lst *ep;

        if ((ep = env_find(var)))
                return(ep->value);
        return(NULL);
}

#if defined(OLD_ENVIRON) && defined(ENV_HACK)
void
env_varval(unsigned char *what)
{
        extern int old_env_var, old_env_value, env_auto;
        int len = strlen((char *)what);

        if (len == 0)
                goto unknown;

        if (strncasecmp((char *)what, "status", len) == 0) {
                if (env_auto)
                        printf("%s%s", "VAR and VALUE are/will be ",
                                        "determined automatically\n");
                if (old_env_var == OLD_ENV_VAR)
                        printf("VAR and VALUE set to correct definitions\n");
                else
                        printf("VAR and VALUE definitions are reversed\n");
        } else if (strncasecmp((char *)what, "auto", len) == 0) {
                env_auto = 1;
                old_env_var = OLD_ENV_VALUE;
                old_env_value = OLD_ENV_VAR;
        } else if (strncasecmp((char *)what, "right", len) == 0) {
                env_auto = 0;
                old_env_var = OLD_ENV_VAR;
                old_env_value = OLD_ENV_VALUE;
        } else if (strncasecmp((char *)what, "wrong", len) == 0) {
                env_auto = 0;
                old_env_var = OLD_ENV_VALUE;
                old_env_value = OLD_ENV_VAR;
        } else {
unknown:
                printf("Unknown \"varval\" command. (\"auto\", \"right\", \"wrong\", \"status\")\n");
        }
}
#endif

#ifdef  AUTHENTICATION
/*
 * The AUTHENTICATE command.
 */

struct authlist {
        const char      *name;
        const char      *help;
        int     (*handler)(char *);
        int     narg;
};

extern int
        auth_enable(char *),
        auth_disable(char *),
        auth_status(void);
static int
        auth_help(void);

struct authlist AuthList[] = {
    { "status", "Display current status of authentication information",
                                                (int (*)(char *))auth_status,   0 },
    { "disable", "Disable an authentication type ('auth disable ?' for more)",
                                                auth_disable,   1 },
    { "enable", "Enable an authentication type ('auth enable ?' for more)",
                                                auth_enable,    1 },
    { "help",   NULL,                           (int (*)(char *))auth_help,             0 },
    { "?",      "Print help information",       (int (*)(char *))auth_help,             0 },
    { NULL, NULL, NULL, 0 },
};

static int
auth_help(void)
{
    struct authlist *c;

    for (c = AuthList; c->name; c++) {
        if (c->help) {
            if (*c->help)
                printf("%-15s %s\n", c->name, c->help);
            else
                printf("\n");
        }
    }
    return 0;
}

int
auth_cmd(int argc, char *argv[])
{
    struct authlist *c;

    if (argc < 2) {
        fprintf(stderr,
            "Need an argument to 'auth' command.  'auth ?' for help.\n");
        return 0;
    }

    c = (struct authlist *)
                genget(argv[1], (char **) AuthList, sizeof(struct authlist));
    if (c == 0) {
        fprintf(stderr, "'%s': unknown argument ('auth ?' for help).\n",
                                argv[1]);
        return 0;
    }
    if (Ambiguous((void *)c)) {
        fprintf(stderr, "'%s': ambiguous argument ('auth ?' for help).\n",
                                argv[1]);
        return 0;
    }
    if (c->narg + 2 != argc) {
        fprintf(stderr,
            "Need %s%d argument%s to 'auth %s' command.  'auth ?' for help.\n",
                c->narg < argc + 2 ? "only " : "",
                c->narg, c->narg == 1 ? "" : "s", c->name);
        return 0;
    }
    return((*c->handler)(argv[2]));
}
#endif

#ifdef  ENCRYPTION
/*
 * The ENCRYPT command.
 */

struct encryptlist {
        const char      *name;
        const char      *help;
        int     (*handler)(char *, char *);
        int     needconnect;
        int     minarg;
        int     maxarg;
};

extern int
        EncryptEnable(char *, char *),
        EncryptDisable(char *, char *),
        EncryptType(char *, char *),
        EncryptStart(char *),
        EncryptStartInput(void),
        EncryptStartOutput(void),
        EncryptStop(char *),
        EncryptStopInput(void),
        EncryptStopOutput(void),
        EncryptStatus(void);
static int
        EncryptHelp(void);

struct encryptlist EncryptList[] = {
    { "enable", "Enable encryption. ('encrypt enable ?' for more)",
                                                EncryptEnable, 1, 1, 2 },
    { "disable", "Disable encryption. ('encrypt enable ?' for more)",
                                                EncryptDisable, 0, 1, 2 },
    { "type", "Set encryption type. ('encrypt type ?' for more)",
                                                EncryptType, 0, 1, 1 },
    { "start", "Start encryption. ('encrypt start ?' for more)",
                                                (int (*)(char *, char *))EncryptStart, 1, 0, 1 },
    { "stop", "Stop encryption. ('encrypt stop ?' for more)",
                                                (int (*)(char *, char *))EncryptStop, 1, 0, 1 },
    { "input", "Start encrypting the input stream",
                                                (int (*)(char *, char *))EncryptStartInput, 1, 0, 0 },
    { "-input", "Stop encrypting the input stream",
                                                (int (*)(char *, char *))EncryptStopInput, 1, 0, 0 },
    { "output", "Start encrypting the output stream",
                                                (int (*)(char *, char *))EncryptStartOutput, 1, 0, 0 },
    { "-output", "Stop encrypting the output stream",
                                                (int (*)(char *, char *))EncryptStopOutput, 1, 0, 0 },

    { "status", "Display current status of authentication information",
                                                (int (*)(char *, char *))EncryptStatus, 0, 0, 0 },
    { "help",   NULL,                           (int (*)(char *, char *))EncryptHelp,   0, 0, 0 },
    { "?",      "Print help information",       (int (*)(char *, char *))EncryptHelp,   0, 0, 0 },
    { NULL, NULL, NULL, 0, 0, 0 },
};

static int
EncryptHelp(void)
{
    struct encryptlist *c;

    for (c = EncryptList; c->name; c++) {
        if (c->help) {
            if (*c->help)
                printf("%-15s %s\n", c->name, c->help);
            else
                printf("\n");
        }
    }
    return 0;
}

static int
encrypt_cmd(int argc, char *argv[])
{
    struct encryptlist *c;

    if (argc < 2) {
        fprintf(stderr,
            "Need an argument to 'encrypt' command.  'encrypt ?' for help.\n");
        return 0;
    }

    c = (struct encryptlist *)
                genget(argv[1], (char **) EncryptList, sizeof(struct encryptlist));
    if (c == 0) {
        fprintf(stderr, "'%s': unknown argument ('encrypt ?' for help).\n",
                                argv[1]);
        return 0;
    }
    if (Ambiguous((void *)c)) {
        fprintf(stderr, "'%s': ambiguous argument ('encrypt ?' for help).\n",
                                argv[1]);
        return 0;
    }
    argc -= 2;
    if (argc < c->minarg || argc > c->maxarg) {
        if (c->minarg == c->maxarg) {
            fprintf(stderr, "Need %s%d argument%s ",
                c->minarg < argc ? "only " : "", c->minarg,
                c->minarg == 1 ? "" : "s");
        } else {
            fprintf(stderr, "Need %s%d-%d arguments ",
                c->maxarg < argc ? "only " : "", c->minarg, c->maxarg);
        }
        fprintf(stderr, "to 'encrypt %s' command.  'encrypt ?' for help.\n",
                c->name);
        return 0;
    }
    if (c->needconnect && !connected) {
        if (!(argc && (isprefix(argv[2], "help") || isprefix(argv[2], "?")))) {
            printf("?Need to be connected first.\n");
            return 0;
        }
    }
    return ((*c->handler)(argc > 0 ? argv[2] : 0,
                        argc > 1 ? argv[3] : 0));
}
#endif  /* ENCRYPTION */

/*
 * Print status about the connection.
 */
/*ARGSUSED*/
static int
status(int argc, char *argv[])
{
    if (connected) {
        printf("Connected to %s.\n", hostname);
        if ((argc < 2) || strcmp(argv[1], "notmuch")) {
            int mode = getconnmode();

            if (my_want_state_is_will(TELOPT_LINEMODE)) {
                printf("Operating with LINEMODE option\n");
                printf("%s line editing\n", (mode&MODE_EDIT) ? "Local" : "No");
                printf("%s catching of signals\n",
                                        (mode&MODE_TRAPSIG) ? "Local" : "No");
                slcstate();
#ifdef  KLUDGELINEMODE
            } else if (kludgelinemode && my_want_state_is_dont(TELOPT_SGA)) {
                printf("Operating in obsolete linemode\n");
#endif
            } else {
                printf("Operating in single character mode\n");
                if (localchars)
                    printf("Catching signals locally\n");
            }
            printf("%s character echo\n", (mode&MODE_ECHO) ? "Local" : "Remote");
            if (my_want_state_is_will(TELOPT_LFLOW))
                printf("%s flow control\n", (mode&MODE_FLOW) ? "Local" : "No");
#ifdef  ENCRYPTION
            encrypt_display();
#endif  /* ENCRYPTION */
        }
    } else {
        printf("No connection.\n");
    }
    printf("Escape character is '%s'.\n", control(escape));
    (void) fflush(stdout);
    return 1;
}

#ifdef  SIGINFO
/*
 * Function that gets called when SIGINFO is received.
 */
void
ayt_status(void)
{
    (void) call(status, "status", "notmuch", 0);
}
#endif

static const char *
sockaddr_ntop(struct sockaddr *sa)
{
    void *addr;
    static char addrbuf[INET6_ADDRSTRLEN];

    switch (sa->sa_family) {
    case AF_INET:
        addr = &((struct sockaddr_in *)sa)->sin_addr;
        break;
    case AF_UNIX:
        addr = &((struct sockaddr_un *)sa)->sun_path;
        break;
#ifdef INET6
    case AF_INET6:
        addr = &((struct sockaddr_in6 *)sa)->sin6_addr;
        break;
#endif
    default:
        return NULL;
    }
    inet_ntop(sa->sa_family, addr, addrbuf, sizeof(addrbuf));
    return addrbuf;
}

#if defined(IPSEC) && defined(IPSEC_POLICY_IPSEC)
static int
setpolicy(int lnet, struct addrinfo *res, char *policy)
{
        char *buf;
        int level;
        int optname;

        if (policy == NULL)
                return 0;

        buf = ipsec_set_policy(policy, strlen(policy));
        if (buf == NULL) {
                printf("%s\n", ipsec_strerror());
                return -1;
        }
        level = res->ai_family == AF_INET ? IPPROTO_IP : IPPROTO_IPV6;
        optname = res->ai_family == AF_INET ? IP_IPSEC_POLICY : IPV6_IPSEC_POLICY;
        if (setsockopt(lnet, level, optname, buf, ipsec_get_policylen(buf)) < 0){
                perror("setsockopt");
                return -1;
        }

        free(buf);
        return 0;
}
#endif

#ifdef INET6
/*
 * When an Address Family related error happend, check if retry with
 * another AF is possible or not.
 * Return 1, if retry with another af is OK. Else, return 0.
 */
static int
switch_af(struct addrinfo **aip)
{
    int nextaf;
    struct addrinfo *ai;

    ai = *aip;
    nextaf = (ai->ai_family == AF_INET) ? AF_INET6 : AF_INET;
    do
        ai=ai->ai_next;
    while (ai != NULL && ai->ai_family != nextaf);
    *aip = ai;
    if (*aip != NULL) {
        return 1;
    }
    return 0;
}
#endif

int
tn(int argc, char *argv[])
{
    char *srp = 0;
    int proto, opt;
    int srlen;
    int srcroute = 0, result;
    char *cmd, *hostp = 0, *portp = 0, *user = 0;
    char *src_addr = NULL;
    struct addrinfo hints, *res, *res0 = NULL, *src_res, *src_res0 = NULL;
    int error = 0, af_error = 0;

    if (connected) {
        printf("?Already connected to %s\n", hostname);
        setuid(getuid());
        return 0;
    }
    if (argc < 2) {
        (void) strcpy(line, "open ");
        printf("(to) ");
        (void) fgets(&line[strlen(line)], sizeof(line) - strlen(line), stdin);
        makeargv();
        argc = margc;
        argv = margv;
    }
    cmd = *argv;
    --argc; ++argv;
    while (argc) {
        if (strcmp(*argv, "help") == 0 || isprefix(*argv, "?"))
            goto usage;
        if (strcmp(*argv, "-l") == 0) {
            --argc; ++argv;
            if (argc == 0)
                goto usage;
            user = *argv++;
            --argc;
            continue;
        }
        if (strcmp(*argv, "-a") == 0) {
            --argc; ++argv;
            autologin = 1;
            continue;
        }
        if (strcmp(*argv, "-s") == 0) {
            --argc; ++argv;
            if (argc == 0)
                goto usage;
            src_addr = *argv++;
            --argc;
            continue;
        }
        if (hostp == 0) {
            hostp = *argv++;
            --argc;
            continue;
        }
        if (portp == 0) {
            portp = *argv++;
            --argc;
            continue;
        }
    usage:
        printf("usage: %s [-l user] [-a] [-s src_addr] host-name [port]\n", cmd);
        setuid(getuid());
        return 0;
    }
    if (hostp == 0)
        goto usage;

    if (src_addr != NULL) {
        memset(&hints, 0, sizeof(hints));
        hints.ai_flags = AI_NUMERICHOST;
        hints.ai_family = family;
        hints.ai_socktype = SOCK_STREAM;
        error = getaddrinfo(src_addr, 0, &hints, &src_res);
        if (error == EAI_NODATA) {
                hints.ai_flags = 0;
                error = getaddrinfo(src_addr, 0, &hints, &src_res);
        }
        if (error != 0) {
                fprintf(stderr, "%s: %s\n", src_addr, gai_strerror(error));
                if (error == EAI_SYSTEM)
                        fprintf(stderr, "%s: %s\n", src_addr, strerror(errno));
                setuid(getuid());
                return 0;
        }
        src_res0 = src_res;
    }
    if (hostp[0] == '/') {
        struct sockaddr_un su;
        
        if (strlen(hostp) >= sizeof(su.sun_path)) {
            fprintf(stderr, "hostname too long for unix domain socket: %s",
                    hostp);
                goto fail;
        }
        memset(&su, 0, sizeof su);
        su.sun_family = AF_UNIX;
        strncpy(su.sun_path, hostp, sizeof su.sun_path);
        printf("Trying %s...\n", hostp);
        net = socket(PF_UNIX, SOCK_STREAM, 0);
        if ( net < 0) {
            perror("socket");
            goto fail;
        }
        if (connect(net, (struct sockaddr *)&su, sizeof su) == -1) {
            perror(su.sun_path);
            (void) NetClose(net);
            goto fail;
        }
        goto af_unix;
    } else if (hostp[0] == '@' || hostp[0] == '!') {
        if (
#ifdef INET6
            family == AF_INET6 ||
#endif
            (hostname = strrchr(hostp, ':')) == NULL)
            hostname = strrchr(hostp, '@');
        if (hostname == NULL) {
            hostname = hostp;
        } else {
            hostname++;
            srcroute = 1;
        }
    } else
        hostname = hostp;
    if (!portp) {
      telnetport = 1;
      portp = strdup("telnet");
    } else if (*portp == '-') {
      portp++;
      telnetport = 1;
    } else
      telnetport = 0;

    memset(&hints, 0, sizeof(hints));
    hints.ai_flags = AI_NUMERICHOST;
    hints.ai_family = family;
    hints.ai_socktype = SOCK_STREAM;
    error = getaddrinfo(hostname, portp, &hints, &res);
    if (error) {
        hints.ai_flags = AI_CANONNAME;
        error = getaddrinfo(hostname, portp, &hints, &res);
    }
    if (error != 0) {
        fprintf(stderr, "%s: %s\n", hostname, gai_strerror(error));
        if (error == EAI_SYSTEM)
            fprintf(stderr, "%s: %s\n", hostname, strerror(errno));
        setuid(getuid());
        goto fail;
    }
    if (hints.ai_flags == AI_NUMERICHOST) {
        /* hostname has numeric */
        int gni_err = 1;

        if (doaddrlookup)
            gni_err = getnameinfo(res->ai_addr, res->ai_addr->sa_len,
                                  _hostname, sizeof(_hostname) - 1, NULL, 0,
                                  NI_NAMEREQD);
        if (gni_err != 0)
            (void) strncpy(_hostname, hostp, sizeof(_hostname) - 1);
        _hostname[sizeof(_hostname)-1] = '\0';
        hostname = _hostname;
    } else {
        /* hostname has FQDN */
        if (srcroute != 0)
            (void) strncpy(_hostname, hostname, sizeof(_hostname) - 1);
        else if (res->ai_canonname != NULL)
          strcpy(_hostname, res->ai_canonname);
        else
          (void) strncpy(_hostname, hostp, sizeof(_hostname) - 1);
        _hostname[sizeof(_hostname)-1] = '\0';
        hostname = _hostname;
    }
    res0 = res;
 #ifdef INET6
 af_again:
 #endif
    if (srcroute != 0) {
        static char hostbuf[BUFSIZ];

        if (af_error == 0) { /* save intermediate hostnames for retry */
                strncpy(hostbuf, hostp, BUFSIZ - 1);
                hostbuf[BUFSIZ - 1] = '\0';
        } else
                hostp = hostbuf;
        srp = 0;
        result = sourceroute(res, hostp, &srp, &srlen, &proto, &opt);
        if (result == 0) {
#ifdef INET6
            if (family == AF_UNSPEC && af_error == 0 &&
                switch_af(&res) == 1) {
                af_error = 1;
                goto af_again;
            }
#endif
            setuid(getuid());
            goto fail;
        } else if (result == -1) {
            printf("Bad source route option: %s\n", hostp);
            setuid(getuid());
            goto fail;
        }
    }
    do {
        printf("Trying %s...\n", sockaddr_ntop(res->ai_addr));
        net = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
        setuid(getuid());
        if (net < 0) {
#ifdef INET6
            if (family == AF_UNSPEC && af_error == 0 &&
                switch_af(&res) == 1) {
                af_error = 1;
                goto af_again;
            }
#endif
            perror("telnet: socket");
            goto fail;
        }
        if (srp && setsockopt(net, proto, opt, (char *)srp, srlen) < 0)
                perror("setsockopt (source route)");
#if     defined(IPPROTO_IP) && defined(IP_TOS)
        if (res->ai_family == PF_INET) {
# if    defined(HAS_GETTOS)
            struct tosent *tp;
            if (tos < 0 && (tp = gettosbyname("telnet", "tcp")))
                tos = tp->t_tos;
# endif
            if (tos < 0)
                tos = IPTOS_LOWDELAY;
            if (tos
                && (setsockopt(net, IPPROTO_IP, IP_TOS,
                    (char *)&tos, sizeof(int)) < 0)
                && (errno != ENOPROTOOPT))
                    perror("telnet: setsockopt (IP_TOS) (ignored)");
        }
#endif  /* defined(IPPROTO_IP) && defined(IP_TOS) */

        if (debug && SetSockOpt(net, SOL_SOCKET, SO_DEBUG, 1) < 0) {
                perror("setsockopt (SO_DEBUG)");
        }

        if (src_addr != NULL) {
            for (src_res = src_res0; src_res != 0; src_res = src_res->ai_next)
                if (src_res->ai_family == res->ai_family)
                    break;
            if (src_res == NULL)
                src_res = src_res0;
            if (bind(net, src_res->ai_addr, src_res->ai_addrlen) == -1) {
#ifdef INET6
                if (family == AF_UNSPEC && af_error == 0 &&
                    switch_af(&res) == 1) {
                    af_error = 1;
                    (void) NetClose(net);
                    goto af_again;
                }
#endif
                perror("bind");
                (void) NetClose(net);
                goto fail;
            }
        }
#if defined(IPSEC) && defined(IPSEC_POLICY_IPSEC)
        if (setpolicy(net, res, ipsec_policy_in) < 0) {
                (void) NetClose(net);
                goto fail;
        }
        if (setpolicy(net, res, ipsec_policy_out) < 0) {
                (void) NetClose(net);
                goto fail;
        }
#endif

        if (connect(net, res->ai_addr, res->ai_addrlen) < 0) {
            struct addrinfo *next;

            next = res->ai_next;
            /* If already an af failed, only try same af. */
            if (af_error != 0)
                while (next != NULL && next->ai_family != res->ai_family)
                    next = next->ai_next;
            warn("connect to address %s", sockaddr_ntop(res->ai_addr));
            if (next != NULL) {
                res = next;
                (void) NetClose(net);
                continue;
            }
            warnx("Unable to connect to remote host");
            (void) NetClose(net);
            goto fail;
        }
        connected++;
#ifdef  AUTHENTICATION
#ifdef  ENCRYPTION
        auth_encrypt_connect(connected);
#endif
#endif
    } while (connected == 0);
    freeaddrinfo(res0);
    if (src_res0 != NULL)
        freeaddrinfo(src_res0);
    cmdrc(hostp, hostname);
 af_unix:    
    if (autologin && user == NULL) {
        struct passwd *pw;

        user = getenv("USER");
        if (user == NULL ||
            ((pw = getpwnam(user)) && pw->pw_uid != getuid())) {
                if ((pw = getpwuid(getuid())))
                        user = pw->pw_name;
                else
                        user = NULL;
        }
    }
    if (user) {
        env_define("USER", user);
        env_export("USER");
    }
    (void) call(status, "status", "notmuch", 0);
    if (setjmp(peerdied) == 0)
        telnet(user);
    (void) NetClose(net);
    ExitString("Connection closed by foreign host.\n",1);
    /*NOTREACHED*/
 fail:
    if (res0 != NULL)
        freeaddrinfo(res0);
    if (src_res0 != NULL)
        freeaddrinfo(src_res0);
    return 0;
}

#define HELPINDENT (sizeof ("connect"))

static char
        openhelp[] =    "connect to a site",
        closehelp[] =   "close current connection",
        logouthelp[] =  "forcibly logout remote user and close the connection",
        quithelp[] =    "exit telnet",
        statushelp[] =  "print status information",
        helphelp[] =    "print help information",
        sendhelp[] =    "transmit special characters ('send ?' for more)",
        sethelp[] =     "set operating parameters ('set ?' for more)",
        unsethelp[] =   "unset operating parameters ('unset ?' for more)",
        togglestring[] ="toggle operating parameters ('toggle ?' for more)",
        slchelp[] =     "change state of special charaters ('slc ?' for more)",
        displayhelp[] = "display operating parameters",
#ifdef  AUTHENTICATION
        authhelp[] =    "turn on (off) authentication ('auth ?' for more)",
#endif
#ifdef  ENCRYPTION
        encrypthelp[] = "turn on (off) encryption ('encrypt ?' for more)",
#endif  /* ENCRYPTION */
        zhelp[] =       "suspend telnet",
#ifdef OPIE
        opiehelp[] =    "compute response to OPIE challenge",
#endif
        shellhelp[] =   "invoke a subshell",
        envhelp[] =     "change environment variables ('environ ?' for more)",
        modestring[] = "try to enter line or character mode ('mode ?' for more)";

static Command cmdtab[] = {
        { "close",      closehelp,      bye,            1 },
        { "logout",     logouthelp,     (int (*)(int, char **))logout,          1 },
        { "display",    displayhelp,    display,        0 },
        { "mode",       modestring,     modecmd,        0 },
        { "telnet",     openhelp,       tn,             0 },
        { "open",       openhelp,       tn,             0 },
        { "quit",       quithelp,       (int (*)(int, char **))quit,            0 },
        { "send",       sendhelp,       sendcmd,        0 },
        { "set",        sethelp,        setcmd,         0 },
        { "unset",      unsethelp,      unsetcmd,       0 },
        { "status",     statushelp,     status,         0 },
        { "toggle",     togglestring,   toggle,         0 },
        { "slc",        slchelp,        slccmd,         0 },
#ifdef  AUTHENTICATION
        { "auth",       authhelp,       auth_cmd,       0 },
#endif
#ifdef  ENCRYPTION
        { "encrypt",    encrypthelp,    encrypt_cmd,    0 },
#endif  /* ENCRYPTION */
        { "z",          zhelp,          (int (*)(int, char **))suspend, 0 },
        { "!",          shellhelp,      shell,          1 },
        { "environ",    envhelp,        env_cmd,        0 },
        { "?",          helphelp,       help,           0 },
#ifdef OPIE
        { "opie",       opiehelp,       opie_calc,      0 },
#endif          
        { NULL, NULL, NULL, 0 }
};

static char     crmodhelp[] =   "deprecated command -- use 'toggle crmod' instead";
static char     escapehelp[] =  "deprecated command -- use 'set escape' instead";

static Command cmdtab2[] = {
        { "help",       0,              help,           0 },
        { "escape",     escapehelp,     setescape,      0 },
        { "crmod",      crmodhelp,      (int (*)(int, char **))togcrmod,        0 },
        { NULL, NULL, NULL, 0 }
};


/*
 * Call routine with argc, argv set from args (terminated by 0).
 */

static int
call(intrtn_t routine, ...)
{
    va_list ap;
    char *args[100];
    int argno = 0;

    va_start(ap, routine);
    while ((args[argno++] = va_arg(ap, char *)) != 0);
    va_end(ap);
    return (*routine)(argno-1, args);
}


static Command *
getcmd(char *name)
{
    Command *cm;

    if ((cm = (Command *) genget(name, (char **) cmdtab, sizeof(Command))))
        return cm;
    return (Command *) genget(name, (char **) cmdtab2, sizeof(Command));
}

void
command(int top, const char *tbuf, int cnt)
{
    Command *c;

    setcommandmode();
    if (!top) {
        putchar('\n');
    } else {
        (void) signal(SIGINT, SIG_DFL);
        (void) signal(SIGQUIT, SIG_DFL);
    }
    for (;;) {
        if (rlogin == _POSIX_VDISABLE)
                printf("%s> ", prompt);
        if (tbuf) {
            char *cp;
            cp = line;
            while (cnt > 0 && (*cp++ = *tbuf++) != '\n')
                cnt--;
            tbuf = 0;
            if (cp == line || *--cp != '\n' || cp == line)
                goto getline;
            *cp = '\0';
            if (rlogin == _POSIX_VDISABLE)
                printf("%s\n", line);
        } else {
        getline:
            if (rlogin != _POSIX_VDISABLE)
                printf("%s> ", prompt);
            if (fgets(line, sizeof(line), stdin) == NULL) {
                if (feof(stdin) || ferror(stdin)) {
                    (void) quit();
                    /*NOTREACHED*/
                }
                break;
            }
        }
        if (line[0] == 0)
            break;
        makeargv();
        if (margv[0] == 0) {
            break;
        }
        c = getcmd(margv[0]);
        if (Ambiguous((void *)c)) {
            printf("?Ambiguous command\n");
            continue;
        }
        if (c == 0) {
            printf("?Invalid command\n");
            continue;
        }
        if (c->needconnect && !connected) {
            printf("?Need to be connected first.\n");
            continue;
        }
        if ((*c->handler)(margc, margv)) {
            break;
        }
    }
    if (!top) {
        if (!connected) {
            longjmp(toplevel, 1);
            /*NOTREACHED*/
        }
        setconnmode(0);
    }
}
\f
/*
 * Help command.
 */
static int
help(int argc, char *argv[])
{
        Command *c;

        if (argc == 1) {
                printf("Commands may be abbreviated.  Commands are:\n\n");
                for (c = cmdtab; c->name; c++)
                        if (c->help) {
                                printf("%-*s\t%s\n", (int)HELPINDENT, c->name,
                                                                    c->help);
                        }
                return 0;
        }
        else while (--argc > 0) {
                char *arg;
                arg = *++argv;
                c = getcmd(arg);
                if (Ambiguous((void *)c))
                        printf("?Ambiguous help command %s\n", arg);
                else if (c == (Command *)0)
                        printf("?Invalid help command %s\n", arg);
                else
                        printf("%s\n", c->help);
        }
        return 0;
}

static char *rcname = 0;
static char rcbuf[128];

void
cmdrc(char *m1, char *m2)
{
    Command *c;
    FILE *rcfile;
    int gotmachine = 0;
    int l1 = strlen(m1);
    int l2 = strlen(m2);
    char m1save[MAXHOSTNAMELEN];

    if (skiprc)
        return;

    strlcpy(m1save, m1, sizeof(m1save));
    m1 = m1save;

    if (rcname == 0) {
        rcname = getenv("HOME");
        if (rcname && (strlen(rcname) + 10) < sizeof(rcbuf))
            strcpy(rcbuf, rcname);
        else
            rcbuf[0] = '\0';
        strcat(rcbuf, "/.telnetrc");
        rcname = rcbuf;
    }

    if ((rcfile = fopen(rcname, "r")) == 0) {
        return;
    }

    for (;;) {
        if (fgets(line, sizeof(line), rcfile) == NULL)
            break;
        if (line[0] == 0)
            break;
        if (line[0] == '#')
            continue;
        if (gotmachine) {
            if (!isspace(line[0]))
                gotmachine = 0;
        }
        if (gotmachine == 0) {
            if (isspace(line[0]))
                continue;
            if (strncasecmp(line, m1, l1) == 0)
                strncpy(line, &line[l1], sizeof(line) - l1);
            else if (strncasecmp(line, m2, l2) == 0)
                strncpy(line, &line[l2], sizeof(line) - l2);
            else if (strncasecmp(line, "DEFAULT", 7) == 0)
                strncpy(line, &line[7], sizeof(line) - 7);
            else
                continue;
            if (line[0] != ' ' && line[0] != '\t' && line[0] != '\n')
                continue;
            gotmachine = 1;
        }
        makeargv();
        if (margv[0] == 0)
            continue;
        c = getcmd(margv[0]);
        if (Ambiguous((void *)c)) {
            printf("?Ambiguous command: %s\n", margv[0]);
            continue;
        }
        if (c == 0) {
            printf("?Invalid command: %s\n", margv[0]);
            continue;
        }
        /*
         * This should never happen...
         */
        if (c->needconnect && !connected) {
            printf("?Need to be connected first for %s.\n", margv[0]);
            continue;
        }
        (*c->handler)(margc, margv);
    }
    fclose(rcfile);
}

/*
 * Source route is handed in as
 *      [!]@hop1@hop2...[@|:]dst
 * If the leading ! is present, it is a
 * strict source route, otherwise it is
 * assmed to be a loose source route.
 *
 * We fill in the source route option as
 *      hop1,hop2,hop3...dest
 * and return a pointer to hop1, which will
 * be the address to connect() to.
 *
 * Arguments:
 *
 *      res:    ponter to addrinfo structure which contains sockaddr to
 *              the host to connect to.
 *
 *      arg:    pointer to route list to decipher
 *
 *      cpp:    If *cpp is not equal to NULL, this is a
 *              pointer to a pointer to a character array
 *              that should be filled in with the option.
 *
 *      lenp:   pointer to an integer that contains the
 *              length of *cpp if *cpp != NULL.
 *
 *      protop: pointer to an integer that should be filled in with
 *              appropriate protocol for setsockopt, as socket 
 *              protocol family.
 *
 *      optp:   pointer to an integer that should be filled in with
 *              appropriate option for setsockopt, as socket protocol
 *              family.
 *
 * Return values:
 *
 *      If the return value is 1, then all operations are
 *      successful. If the
 *      return value is -1, there was a syntax error in the
 *      option, either unknown characters, or too many hosts.
 *      If the return value is 0, one of the hostnames in the
 *      path is unknown, and *cpp is set to point to the bad
 *      hostname.
 *
 *      *cpp:   If *cpp was equal to NULL, it will be filled
 *              in with a pointer to our static area that has
 *              the option filled in.  This will be 32bit aligned.
 *
 *      *lenp:  This will be filled in with how long the option
 *              pointed to by *cpp is.
 *
 *      *protop: This will be filled in with appropriate protocol for
 *               setsockopt, as socket protocol family.
 *
 *      *optp:  This will be filled in with appropriate option for
 *              setsockopt, as socket protocol family.
 */
static int
sourceroute(struct addrinfo *ai, char *arg, char **cpp, int *lenp, int *protop, int *optp)
{
        static char buf[1024 + ALIGNBYTES];     /*XXX*/
        char *cp, *cp2, *lsrp, *ep;
        struct sockaddr_in *_sin;
#ifdef INET6
        struct sockaddr_in6 *sin6;
        struct cmsghdr *cmsg;
#endif
        struct addrinfo hints, *res;
        int error;
        char c;

        /*
         * Verify the arguments, and make sure we have
         * at least 7 bytes for the option.
         */
        if (cpp == NULL || lenp == NULL)
                return -1;
        if (*cpp != NULL) {
                switch (res->ai_family) {
                case AF_INET:
                        if (*lenp < 7)
                                return -1;
                        break;
#ifdef INET6
                case AF_INET6:
                        if (*lenp < (int)CMSG_SPACE(sizeof(struct ip6_rthdr) +
                                               sizeof(struct in6_addr)))
                                return -1;
                        break;
#endif
                }
        }
        /*
         * Decide whether we have a buffer passed to us,
         * or if we need to use our own static buffer.
         */
        if (*cpp) {
                lsrp = *cpp;
                ep = lsrp + *lenp;
        } else {
                *cpp = lsrp = (char *)ALIGN(buf);
                ep = lsrp + 1024;
        }

        cp = arg;

#ifdef INET6
        if (ai->ai_family == AF_INET6) {
                cmsg = inet6_rthdr_init(*cpp, IPV6_RTHDR_TYPE_0);
                if (*cp != '@')
                        return -1;
                *protop = IPPROTO_IPV6;
                *optp = IPV6_PKTOPTIONS;
        } else
#endif
      {
        /*
         * Next, decide whether we have a loose source
         * route or a strict source route, and fill in
         * the begining of the option.
         */
        if (*cp == '!') {
                cp++;
                *lsrp++ = IPOPT_SSRR;
        } else
                *lsrp++ = IPOPT_LSRR;

        if (*cp != '@')
                return -1;

        lsrp++;         /* skip over length, we'll fill it in later */
        *lsrp++ = 4;
        *protop = IPPROTO_IP;
        *optp = IP_OPTIONS;
      }

        cp++;
        memset(&hints, 0, sizeof(hints));
        hints.ai_family = ai->ai_family;
        hints.ai_socktype = SOCK_STREAM;
        for (c = 0;;) {
                if (
#ifdef INET6
                    ai->ai_family != AF_INET6 &&
#endif
                    c == ':')
                        cp2 = 0;
                else for (cp2 = cp; (c = *cp2); cp2++) {
                        if (c == ',') {
                                *cp2++ = '\0';
                                if (*cp2 == '@')
                                        cp2++;
                        } else if (c == '@') {
                                *cp2++ = '\0';
                        } else if (
#ifdef INET6
                                   ai->ai_family != AF_INET6 &&
#endif
                                   c == ':') {
                                *cp2++ = '\0';
                        } else
                                continue;
                        break;
                }
                if (!c)
                        cp2 = 0;

                hints.ai_flags = AI_NUMERICHOST;
                error = getaddrinfo(cp, NULL, &hints, &res);
                if (error == EAI_NODATA) {
                        hints.ai_flags = 0;
                        error = getaddrinfo(cp, NULL, &hints, &res);
                }
                if (error != 0) {
                        fprintf(stderr, "%s: %s\n", cp, gai_strerror(error));
                        if (error == EAI_SYSTEM)
                                fprintf(stderr, "%s: %s\n", cp,
                                        strerror(errno));
                        *cpp = cp;
                        return(0);
                }
#ifdef INET6
                if (res->ai_family == AF_INET6) {
                        sin6 = (struct sockaddr_in6 *)res->ai_addr;
                        inet6_rthdr_add(cmsg, &sin6->sin6_addr,
                                        IPV6_RTHDR_LOOSE);
                } else
#endif
              {
                _sin = (struct sockaddr_in *)res->ai_addr;
                memcpy(lsrp, (char *)&_sin->sin_addr, 4);
                lsrp += 4;
              }
                if (cp2)
                        cp = cp2;
                else
                        break;
                /*
                 * Check to make sure there is space for next address
                 */
#ifdef INET6
                if (res->ai_family == AF_INET6) {
                        if (((char *)CMSG_DATA(cmsg) +
                             sizeof(struct ip6_rthdr) +
                             ((inet6_rthdr_segments(cmsg) + 1) *
                              sizeof(struct in6_addr))) > ep)
                        return -1;
                } else
#endif
                if (lsrp + 4 > ep)
                        return -1;
                freeaddrinfo(res);
        }
#ifdef INET6
        if (res->ai_family == AF_INET6) {
                inet6_rthdr_lasthop(cmsg, IPV6_RTHDR_LOOSE);
                *lenp = cmsg->cmsg_len;
        } else
#endif
      {
        if ((*(*cpp+IPOPT_OLEN) = lsrp - *cpp) <= 7) {
                *cpp = 0;
                *lenp = 0;
                return -1;
        }
        *lsrp++ = IPOPT_NOP; /* 32 bit word align it */
        *lenp = lsrp - *cpp;
      }
        freeaddrinfo(res);
        return 1;
}