/*
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. 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.
 */

#define PRINTOPTIONS
#include "telnetd.h"

RCSID("$Id$");

/*
 * utility functions performing io related tasks
 */

/*
 * ttloop
 *
 * A small subroutine to flush the network output buffer, get some
 * data from the network, and pass it through the telnet state
 * machine.  We also flush the pty input buffer (by dropping its data)
 * if it becomes too full.
 *
 * return 0 if OK or 1 if interrupted by a signal.
 */

int
ttloop(void)
{
    DIAG(TD_REPORT, {
        output_data("td: ttloop\r\n");
    });
    if (nfrontp-nbackp)
        netflush();
    ncc = read(net, netibuf, sizeof netibuf);
    if (ncc < 0) {
        if (errno == EINTR)
            return 1;
        syslog(LOG_INFO, "ttloop:  read: %m\n");
        exit(1);
    } else if (ncc == 0) {
        syslog(LOG_INFO, "ttloop:  peer died\n");
        exit(1);
    }
    DIAG(TD_REPORT, {
        output_data("td: ttloop read %d chars\r\n", ncc);
    });
    netip = netibuf;
    telrcv();                   /* state machine */
    if (ncc > 0) {
        pfrontp = pbackp = ptyobuf;
        telrcv();
    }
    return 0;
}  /* end of ttloop */

/*
 * Check a descriptor to see if out of band data exists on it.
 */
int
stilloob(int s)
{
    static struct timeval timeout = { 0 };
    fd_set      excepts;
    int value;

    if (s >= FD_SETSIZE)
        fatal(ourpty, "fd too large");

    do {
        FD_ZERO(&excepts);
        FD_SET(s, &excepts);
        value = select(s+1, 0, 0, &excepts, &timeout);
    } while ((value == -1) && (errno == EINTR));

    if (value < 0) {
        fatalperror(ourpty, "select");
    }
    if (FD_ISSET(s, &excepts)) {
        return 1;
    } else {
        return 0;
    }
}

void
ptyflush(void)
{
    int n;

    if ((n = pfrontp - pbackp) > 0) {
        DIAG((TD_REPORT | TD_PTYDATA), {
            output_data("td: ptyflush %d chars\r\n", n);
        });
        DIAG(TD_PTYDATA, printdata("pd", pbackp, n));
        n = write(ourpty, pbackp, n);
    }
    if (n < 0) {
        if (errno == EWOULDBLOCK || errno == EINTR)
            return;
        cleanup(0);
    }
    pbackp += n;
    if (pbackp == pfrontp)
        pbackp = pfrontp = ptyobuf;
}

/*
 * nextitem()
 *
 *      Return the address of the next "item" in the TELNET data
 * stream.  This will be the address of the next character if
 * the current address is a user data character, or it will
 * be the address of the character following the TELNET command
 * if the current address is a TELNET IAC ("I Am a Command")
 * character.
 */
char *
nextitem(char *current)
{
    if ((*current&0xff) != IAC) {
        return current+1;
    }
    switch (*(current+1)&0xff) {
    case DO:
    case DONT:
    case WILL:
    case WONT:
        return current+3;
    case SB:{
        /* loop forever looking for the SE */
        char *look = current+2;

        for (;;) {
            if ((*look++&0xff) == IAC) {
                if ((*look++&0xff) == SE) {
                    return look;
                }
            }
        }
    }
    default:
        return current+2;
    }
}


/*
 * netclear()
 *
 *      We are about to do a TELNET SYNCH operation.  Clear
 * the path to the network.
 *
 *      Things are a bit tricky since we may have sent the first
 * byte or so of a previous TELNET command into the network.
 * So, we have to scan the network buffer from the beginning
 * until we are up to where we want to be.
 *
 *      A side effect of what we do, just to keep things
 * simple, is to clear the urgent data pointer.  The principal
 * caller should be setting the urgent data pointer AFTER calling
 * us in any case.
 */
void
netclear(void)
{
    char *thisitem, *next;
    char *good;
#define wewant(p)       ((nfrontp > p) && ((*p&0xff) == IAC) && \
                         ((*(p+1)&0xff) != EC) && ((*(p+1)&0xff) != EL))

#ifdef ENCRYPTION
        thisitem = nclearto > netobuf ? nclearto : netobuf;
#else
        thisitem = netobuf;
#endif

        while ((next = nextitem(thisitem)) <= nbackp) {
            thisitem = next;
        }

        /* Now, thisitem is first before/at boundary. */

#ifdef ENCRYPTION
        good = nclearto > netobuf ? nclearto : netobuf;
#else
        good = netobuf; /* where the good bytes go */
#endif

        while (nfrontp > thisitem) {
            if (wewant(thisitem)) {
                int length;

                next = thisitem;
                do {
                    next = nextitem(next);
                } while (wewant(next) && (nfrontp > next));
                length = next-thisitem;
                memmove(good, thisitem, length);
                good += length;
                thisitem = next;
            } else {
                thisitem = nextitem(thisitem);
            }
        }

        nbackp = netobuf;
        nfrontp = good;         /* next byte to be sent */
        neturg = 0;
}  /* end of netclear */

extern int not42;

/*
 *  netflush
 *              Send as much data as possible to the network,
 *      handling requests for urgent data.
 */
void
netflush(void)
{
    int n;

    if ((n = nfrontp - nbackp) > 0) {
        DIAG(TD_REPORT,
             { n += output_data("td: netflush %d chars\r\n", n);
             });
#ifdef ENCRYPTION
        if (encrypt_output) {
            char *s = nclearto ? nclearto : nbackp;
            if (nfrontp - s > 0) {
                (*encrypt_output)((unsigned char *)s, nfrontp-s);
                nclearto = nfrontp;
            }
        }
#endif
        /*
         * if no urgent data, or if the other side appears to be an
         * old 4.2 client (and thus unable to survive TCP urgent data),
         * write the entire buffer in non-OOB mode.
         */
#if 1 /* remove this to make it work between solaris 2.6 and linux */
        if ((neturg == 0) || (not42 == 0)) {
#endif
            n = write(net, nbackp, n);  /* normal write */
#if 1 /* remove this to make it work between solaris 2.6 and linux */
        } else {
            n = neturg - nbackp;
            /*
             * In 4.2 (and 4.3) systems, there is some question about
             * what byte in a sendOOB operation is the "OOB" data.
             * To make ourselves compatible, we only send ONE byte
             * out of band, the one WE THINK should be OOB (though
             * we really have more the TCP philosophy of urgent data
             * rather than the Unix philosophy of OOB data).
             */
            if (n > 1) {
                n = send(net, nbackp, n-1, 0);  /* send URGENT all by itself */
            } else {
                n = send(net, nbackp, n, MSG_OOB);      /* URGENT data */
            }
        }
#endif
    }
    if (n < 0) {
        if (errno == EWOULDBLOCK || errno == EINTR)
            return;
        cleanup(0);
    }
    nbackp += n;
#ifdef ENCRYPTION
    if (nbackp > nclearto)
        nclearto = 0;
#endif
    if (nbackp >= neturg) {
        neturg = 0;
    }
    if (nbackp == nfrontp) {
        nbackp = nfrontp = netobuf;
#ifdef ENCRYPTION
        nclearto = 0;
#endif
    }
    return;
}


/*
 * writenet
 *
 * Just a handy little function to write a bit of raw data to the net.
 * It will force a transmit of the buffer if necessary
 *
 * arguments
 *    ptr - A pointer to a character string to write
 *    len - How many bytes to write
 */
void
writenet(const void *ptr, size_t len)
{
    /* flush buffer if no room for new data) */
    while ((&netobuf[BUFSIZ] - nfrontp) < len) {
        /* if this fails, don't worry, buffer is a little big */
        netflush();
    }
    if ((&netobuf[BUFSIZ] - nfrontp) < len)
        abort();

    memmove(nfrontp, ptr, len);
    nfrontp += len;
}


/*
 * miscellaneous functions doing a variety of little jobs follow ...
 */


void fatal(int f, char *msg)
{
    char buf[BUFSIZ];

    snprintf(buf, sizeof(buf), "telnetd: %s.\r\n", msg);
#ifdef ENCRYPTION
    if (encrypt_output) {
        /*
         * Better turn off encryption first....
         * Hope it flushes...
         */
        encrypt_send_end();
        netflush();
    }
#endif
    write(f, buf, (int)strlen(buf));
    sleep(1);   /*XXX*/
    exit(1);
}

void
fatalperror_errno(int f, const char *msg, int error)
{
    char buf[BUFSIZ];

    snprintf(buf, sizeof(buf), "%s: %s", msg, strerror(error));
    fatal(f, buf);
}

void
fatalperror(int f, const char *msg)
{
    fatalperror_errno(f, msg, errno);
}

char editedhost[32];

void edithost(char *pat, char *host)
{
    char *res = editedhost;

    if (!pat)
        pat = "";
    while (*pat) {
        switch (*pat) {

        case '#':
            if (*host)
                host++;
            break;

        case '@':
            if (*host)
                *res++ = *host++;
            break;

        default:
            *res++ = *pat;
            break;
        }
        if (res == &editedhost[sizeof editedhost - 1]) {
            *res = '\0';
            return;
        }
        pat++;
    }
    if (*host)
        strlcpy (res, host,
                         sizeof editedhost - (res - editedhost));
    else
        *res = '\0';
    editedhost[sizeof editedhost - 1] = '\0';
}

static char *putlocation;

void
putstr(char *s)
{

    while (*s)
        putchr(*s++);
}

void
putchr(int cc)
{
    *putlocation++ = cc;
}

static char fmtstr[] = { "%l:%M%P on %A, %d %B %Y" };

void putf(char *cp, char *where)
{
#ifdef HAVE_UNAME
    struct utsname name;
#endif
    char *slash;
    time_t t;
    char db[100];

    /* if we don't have uname, set these to sensible values */
    char *sysname = "Unix",
        *machine = "",
        *release = "",
        *version = "";

#ifdef HAVE_UNAME
    uname(&name);
    sysname=name.sysname;
    machine=name.machine;
    release=name.release;
    version=name.version;
#endif

    putlocation = where;

    while (*cp) {
        if (*cp != '%') {
            putchr(*cp++);
            continue;
        }
        switch (*++cp) {

        case 't':
            slash = strchr(line+1, '/');
            if (slash == (char *) 0)
                putstr(line);
            else
                putstr(&slash[1]);
            break;

        case 'h':
            putstr(editedhost);
            break;

        case 's':
            putstr(sysname);
            break;

        case 'm':
            putstr(machine);
            break;

        case 'r':
            putstr(release);
            break;

        case 'v':
            putstr(version);
            break;

        case 'd':
            time(&t);
            strftime(db, sizeof(db), fmtstr, localtime(&t));
            putstr(db);
            break;

        case '%':
            putchr('%');
            break;
        }
        cp++;
    }
}

#ifdef DIAGNOSTICS
/*
 * Print telnet options and commands in plain text, if possible.
 */
void
printoption(char *fmt, int option)
{
    if (TELOPT_OK(option))
        output_data("%s %s\r\n",
                    fmt,
                    TELOPT(option));
    else if (TELCMD_OK(option))
        output_data("%s %s\r\n",
                    fmt,
                    TELCMD(option));
    else
        output_data("%s %d\r\n",
                    fmt,
                    option);
    return;
}

void
printsub(int direction, unsigned char *pointer, size_t length)
                                        /* '<' or '>' */
                                        /* where suboption data sits */
                                        /* length of suboption data */
{
    int i = 0;
    unsigned char buf[512];

    if (!(diagnostic & TD_OPTIONS))
        return;

    if (direction) {
        output_data("td: %s suboption ",
                    direction == '<' ? "recv" : "send");
        if (length >= 3) {
            int j;

            i = pointer[length-2];
            j = pointer[length-1];

            if (i != IAC || j != SE) {
                output_data("(terminated by ");
                if (TELOPT_OK(i))
                    output_data("%s ",
                                TELOPT(i));
                else if (TELCMD_OK(i))
                    output_data("%s ",
                                TELCMD(i));
                else
                    output_data("%d ",
                                i);
                if (TELOPT_OK(j))
                    output_data("%s",
                                TELOPT(j));
                else if (TELCMD_OK(j))
                    output_data("%s",
                                TELCMD(j));
                else
                    output_data("%d",
                                j);
                output_data(", not IAC SE!) ");
            }
        }
        length -= 2;
    }
    if (length < 1) {
        output_data("(Empty suboption??\?)");
        return;
    }
    switch (pointer[0]) {
    case TELOPT_TTYPE:
        output_data("TERMINAL-TYPE ");
        switch (pointer[1]) {
        case TELQUAL_IS:
            output_data("IS \"%.*s\"",
                        (int)(length-2),
                        (char *)pointer+2);
            break;
        case TELQUAL_SEND:
            output_data("SEND");
            break;
        default:
            output_data("- unknown qualifier %d (0x%x).",
                        pointer[1], pointer[1]);
        }
        break;
    case TELOPT_TSPEED:
        output_data("TERMINAL-SPEED");
        if (length < 2) {
            output_data(" (empty suboption??\?)");
            break;
        }
        switch (pointer[1]) {
        case TELQUAL_IS:
            output_data(" IS %.*s", (int)(length-2), (char *)pointer+2);
            break;
        default:
            if (pointer[1] == 1)
                output_data(" SEND");
            else
                output_data(" %d (unknown)", pointer[1]);
            for (i = 2; i < length; i++) {
                output_data(" ?%d?", pointer[i]);
            }
            break;
        }
        break;

    case TELOPT_LFLOW:
        output_data("TOGGLE-FLOW-CONTROL");
        if (length < 2) {
            output_data(" (empty suboption??\?)");
            break;
        }
        switch (pointer[1]) {
        case LFLOW_OFF:
            output_data(" OFF");
            break;
        case LFLOW_ON:
            output_data(" ON");
            break;
        case LFLOW_RESTART_ANY:
            output_data(" RESTART-ANY");
            break;
        case LFLOW_RESTART_XON:
            output_data(" RESTART-XON");
            break;
        default:
            output_data(" %d (unknown)",
                        pointer[1]);
        }
        for (i = 2; i < length; i++) {
            output_data(" ?%d?",
                        pointer[i]);
        }
        break;

    case TELOPT_NAWS:
        output_data("NAWS");
        if (length < 2) {
            output_data(" (empty suboption??\?)");
            break;
        }
        if (length == 2) {
            output_data(" ?%d?",
                        pointer[1]);
            break;
        }
        output_data(" %u %u(%u)",
                    pointer[1],
                    pointer[2],
                    (((unsigned int)pointer[1])<<8) + pointer[2]);
        if (length == 4) {
            output_data(" ?%d?",
                        pointer[3]);
            break;
        }
        output_data(" %u %u(%u)",
                    pointer[3],
                    pointer[4],
                    (((unsigned int)pointer[3])<<8) + pointer[4]);
        for (i = 5; i < length; i++) {
            output_data(" ?%d?",
                        pointer[i]);
        }
        break;

    case TELOPT_LINEMODE:
        output_data("LINEMODE ");
        if (length < 2) {
            output_data(" (empty suboption??\?)");
            break;
        }
        switch (pointer[1]) {
        case WILL:
            output_data("WILL ");
            goto common;
        case WONT:
            output_data("WONT ");
            goto common;
        case DO:
            output_data("DO ");
            goto common;
        case DONT:
            output_data("DONT ");
        common:
            if (length < 3) {
                output_data("(no option??\?)");
                break;
            }
            switch (pointer[2]) {
            case LM_FORWARDMASK:
                output_data("Forward Mask");
                for (i = 3; i < length; i++) {
                    output_data(" %x", pointer[i]);
                }
                break;
            default:
                output_data("%d (unknown)",
                            pointer[2]);
                for (i = 3; i < length; i++) {
                    output_data(" %d",
                                pointer[i]);
                }
                break;
            }
            break;

        case LM_SLC:
            output_data("SLC");
            for (i = 2; i < length - 2; i += 3) {
                if (SLC_NAME_OK(pointer[i+SLC_FUNC]))
                    output_data(" %s",
                                SLC_NAME(pointer[i+SLC_FUNC]));
                else
                    output_data(" %d",
                                pointer[i+SLC_FUNC]);
                switch (pointer[i+SLC_FLAGS]&SLC_LEVELBITS) {
                case SLC_NOSUPPORT:
                    output_data(" NOSUPPORT");
                    break;
                case SLC_CANTCHANGE:
                    output_data(" CANTCHANGE");
                    break;
                case SLC_VARIABLE:
                    output_data(" VARIABLE");
                    break;
                case SLC_DEFAULT:
                    output_data(" DEFAULT");
                    break;
                }
                output_data("%s%s%s",
                            pointer[i+SLC_FLAGS]&SLC_ACK ? "|ACK" : "",
                            pointer[i+SLC_FLAGS]&SLC_FLUSHIN ? "|FLUSHIN" : "",
                            pointer[i+SLC_FLAGS]&SLC_FLUSHOUT ? "|FLUSHOUT" : "");
                if (pointer[i+SLC_FLAGS]& ~(SLC_ACK|SLC_FLUSHIN|
                                            SLC_FLUSHOUT| SLC_LEVELBITS)) {
                    output_data("(0x%x)",
                                pointer[i+SLC_FLAGS]);
                }
                output_data(" %d;",
                            pointer[i+SLC_VALUE]);
                if ((pointer[i+SLC_VALUE] == IAC) &&
                    (pointer[i+SLC_VALUE+1] == IAC))
                    i++;
            }
            for (; i < length; i++) {
                output_data(" ?%d?",
                            pointer[i]);
            }
            break;

        case LM_MODE:
            output_data("MODE ");
            if (length < 3) {
                output_data("(no mode??\?)");
                break;
            }
            {
                char tbuf[32];
                snprintf(tbuf,
                         sizeof(tbuf),
                         "%s%s%s%s%s",
                         pointer[2]&MODE_EDIT ? "|EDIT" : "",
                         pointer[2]&MODE_TRAPSIG ? "|TRAPSIG" : "",
                         pointer[2]&MODE_SOFT_TAB ? "|SOFT_TAB" : "",
                         pointer[2]&MODE_LIT_ECHO ? "|LIT_ECHO" : "",
                         pointer[2]&MODE_ACK ? "|ACK" : "");
                output_data("%s",
                            tbuf[1] ? &tbuf[1] : "0");
            }
            if (pointer[2]&~(MODE_EDIT|MODE_TRAPSIG|MODE_ACK)) {
                output_data(" (0x%x)",
                            pointer[2]);
            }
            for (i = 3; i < length; i++) {
                output_data(" ?0x%x?",
                         pointer[i]);
            }
            break;
        default:
            output_data("%d (unknown)",
                        pointer[1]);
            for (i = 2; i < length; i++) {
                output_data(" %d", pointer[i]);
            }
        }
        break;

    case TELOPT_STATUS: {
        char *cp;
        int j, k;

        output_data("STATUS");

        switch (pointer[1]) {
        default:
            if (pointer[1] == TELQUAL_SEND)
                output_data(" SEND");
            else
                output_data(" %d (unknown)",
                            pointer[1]);
            for (i = 2; i < length; i++) {
                output_data(" ?%d?",
                            pointer[i]);
            }
            break;
        case TELQUAL_IS:
            output_data(" IS\r\n");

            for (i = 2; i < length; i++) {
                switch(pointer[i]) {
                case DO:        cp = "DO"; goto common2;
                case DONT:      cp = "DONT"; goto common2;
                case WILL:      cp = "WILL"; goto common2;
                case WONT:      cp = "WONT"; goto common2;
                common2:
                i++;
                if (TELOPT_OK(pointer[i]))
                    output_data(" %s %s",
                                cp,
                                TELOPT(pointer[i]));
                else
                    output_data(" %s %d",
                                cp,
                                pointer[i]);

                output_data("\r\n");
                break;

                case SB:
                    output_data(" SB ");
                    i++;
                    j = k = i;
                    while (j < length) {
                        if (pointer[j] == SE) {
                            if (j+1 == length)
                                break;
                            if (pointer[j+1] == SE)
                                j++;
                            else
                                break;
                        }
                        pointer[k++] = pointer[j++];
                    }
                    printsub(0, &pointer[i], k - i);
                    if (i < length) {
                        output_data(" SE");
                        i = j;
                    } else
                        i = j - 1;

                    output_data("\r\n");

                    break;

                default:
                    output_data(" %d",
                                pointer[i]);
                    break;
                }
            }
            break;
        }
        break;
    }

    case TELOPT_XDISPLOC:
        output_data("X-DISPLAY-LOCATION ");
        switch (pointer[1]) {
        case TELQUAL_IS:
            output_data("IS \"%.*s\"",
                        (int)(length-2),
                        (char *)pointer+2);
            break;
        case TELQUAL_SEND:
            output_data("SEND");
            break;
        default:
            output_data("- unknown qualifier %d (0x%x).",
                        pointer[1], pointer[1]);
        }
        break;

    case TELOPT_NEW_ENVIRON:
        output_data("NEW-ENVIRON ");
        goto env_common1;
    case TELOPT_OLD_ENVIRON:
        output_data("OLD-ENVIRON");
    env_common1:
        switch (pointer[1]) {
        case TELQUAL_IS:
            output_data("IS ");
            goto env_common;
        case TELQUAL_SEND:
            output_data("SEND ");
            goto env_common;
        case TELQUAL_INFO:
            output_data("INFO ");
        env_common:
            {
                int quote = 0;
                for (i = 2; i < length; i++ ) {
                    switch (pointer[i]) {
                    case NEW_ENV_VAR:
                        if (quote)
                            output_data("\" ");
                        output_data("VAR ");
                        quote = 0;
                        break;

                    case NEW_ENV_VALUE:
                        if (quote)
                            output_data("\" ");
                        output_data("VALUE ");
                        quote = 0;
                        break;

                    case ENV_ESC:
                        if (quote)
                            output_data("\" ");
                        output_data("ESC ");
                        quote = 0;
                        break;

                    case ENV_USERVAR:
                        if (quote)
                            output_data("\" ");
                        output_data("USERVAR ");
                        quote = 0;
                        break;

                    default:
                        if (isprint(pointer[i]) && pointer[i] != '"') {
                            if (!quote) {
                                output_data("\"");
                                quote = 1;
                            }
                            output_data("%c", pointer[i]);
                        } else {
                            output_data("%03o ", pointer[i]);
                            quote = 0;
                        }
                        break;
                    }
                }
                if (quote)
                    output_data("\"");
                break;
            }
        }
        break;

#ifdef AUTHENTICATION
    case TELOPT_AUTHENTICATION:
        output_data("AUTHENTICATION");

        if (length < 2) {
            output_data(" (empty suboption??\?)");
            break;
        }
        switch (pointer[1]) {
        case TELQUAL_REPLY:
        case TELQUAL_IS:
            output_data(" %s ",
                        (pointer[1] == TELQUAL_IS) ?
                        "IS" : "REPLY");
            if (AUTHTYPE_NAME_OK(pointer[2]))
                output_data("%s ",
                            AUTHTYPE_NAME(pointer[2]));
            else
                output_data("%d ",
                            pointer[2]);
            if (length < 3) {
                output_data("(partial suboption??\?)");
                break;
            }
            output_data("%s|%s",
                        ((pointer[3] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
                        "CLIENT" : "SERVER",
                        ((pointer[3] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
                        "MUTUAL" : "ONE-WAY");

            auth_printsub(&pointer[1], length - 1, buf, sizeof(buf));
            output_data("%s",
                        buf);
            break;

        case TELQUAL_SEND:
            i = 2;
            output_data(" SEND ");
            while (i < length) {
                if (AUTHTYPE_NAME_OK(pointer[i]))
                    output_data("%s ",
                                AUTHTYPE_NAME(pointer[i]));
                else
                    output_data("%d ",
                                pointer[i]);
                if (++i >= length) {
                    output_data("(partial suboption??\?)");
                    break;
                }
                output_data("%s|%s ",
                            ((pointer[i] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
                            "CLIENT" : "SERVER",
                            ((pointer[i] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
                            "MUTUAL" : "ONE-WAY");
                ++i;
            }
            break;

        case TELQUAL_NAME:
            i = 2;
            output_data(" NAME \"%.*s\"",
                        (int)(length - 2),
                        pointer);
            break;

        default:
            for (i = 2; i < length; i++) {
                output_data(" ?%d?",
                            pointer[i]);
            }
            break;
        }
        break;
#endif

#ifdef ENCRYPTION
    case TELOPT_ENCRYPT:
        output_data("ENCRYPT");
        if (length < 2) {
            output_data(" (empty suboption?)");
            break;
        }
        switch (pointer[1]) {
        case ENCRYPT_START:
            output_data(" START");
            break;

        case ENCRYPT_END:
            output_data(" END");
            break;

        case ENCRYPT_REQSTART:
            output_data(" REQUEST-START");
            break;

        case ENCRYPT_REQEND:
            output_data(" REQUEST-END");
            break;

        case ENCRYPT_IS:
        case ENCRYPT_REPLY:
            output_data(" %s ",
                        (pointer[1] == ENCRYPT_IS) ?
                        "IS" : "REPLY");
            if (length < 3) {
                output_data(" (partial suboption?)");
                break;
            }
            if (ENCTYPE_NAME_OK(pointer[2]))
                output_data("%s ",
                            ENCTYPE_NAME(pointer[2]));
            else
                output_data(" %d (unknown)",
                            pointer[2]);

            encrypt_printsub(&pointer[1], length - 1, buf, sizeof(buf));
            output_data("%s",
                        buf);
            break;

        case ENCRYPT_SUPPORT:
            i = 2;
            output_data(" SUPPORT ");
            while (i < length) {
                if (ENCTYPE_NAME_OK(pointer[i]))
                    output_data("%s ",
                                ENCTYPE_NAME(pointer[i]));
                else
                    output_data("%d ",
                                pointer[i]);
                i++;
            }
            break;

        case ENCRYPT_ENC_KEYID:
            output_data(" ENC_KEYID %d", pointer[1]);
            goto encommon;

        case ENCRYPT_DEC_KEYID:
            output_data(" DEC_KEYID %d", pointer[1]);
            goto encommon;

        default:
            output_data(" %d (unknown)", pointer[1]);
        encommon:
            for (i = 2; i < length; i++) {
                output_data(" %d", pointer[i]);
            }
            break;
        }
        break;
#endif

    default:
        if (TELOPT_OK(pointer[0]))
            output_data("%s (unknown)",
                        TELOPT(pointer[0]));
        else
            output_data("%d (unknown)",
                        pointer[i]);
        for (i = 1; i < length; i++) {
            output_data(" %d", pointer[i]);
        }
        break;
    }
    output_data("\r\n");
}

/*
 * Dump a data buffer in hex and ascii to the output data stream.
 */
void
printdata(char *tag, char *ptr, size_t cnt)
{
    size_t i;
    char xbuf[30];

    while (cnt) {
        /* flush net output buffer if no room for new data) */
        if ((&netobuf[BUFSIZ] - nfrontp) < 80) {
            netflush();
        }

        /* add a line of output */
        output_data("%s: ", tag);
        for (i = 0; i < 20 && cnt; i++) {
            output_data("%02x", *ptr);
            if (isprint((unsigned char)*ptr)) {
                xbuf[i] = *ptr;
            } else {
                xbuf[i] = '.';
            }
            if (i % 2) {
                output_data(" ");
            }
            cnt--;
            ptr++;
        }
        xbuf[i] = '\0';
        output_data(" %s\r\n", xbuf);
    }
}
#endif /* DIAGNOSTICS */