/*
 * 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. 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.
 */

#if 0
#ifndef lint
static const char sccsid[] = "@(#)utility.c     8.4 (Berkeley) 5/30/95";
#endif /* not lint */
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#ifdef __FreeBSD__
#include <locale.h>
#include <sys/utsname.h>
#endif
#include <string.h>
#define PRINTOPTIONS
#include "telnetd.h"

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

/*
 * 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.
 */

    void
ttloop()
{

    DIAG(TD_REPORT, output_data("td: ttloop\r\n"));
    if (nfrontp - nbackp > 0) {
        netflush();
    }
    ncc = read(net, netibuf, sizeof netibuf);
    if (ncc < 0) {
        syslog(LOG_INFO, "ttloop:  read: %m");
        exit(1);
    } else if (ncc == 0) {
        syslog(LOG_INFO, "ttloop:  peer died: %m");
        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();
    }
}  /* 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, 0 };
    fd_set      excepts;
    int value;

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

    if (value < 0) {
        fatalperror(pty, "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(pty, 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.
 */
static char *
nextitem(char *current, const char *endp)
{
    if (current >= endp) {
        return NULL;
    }
    if ((*current&0xff) != IAC) {
        return current+1;
    }
    if (current+1 >= endp) {
        return NULL;
    }
    switch (*(current+1)&0xff) {
    case DO:
    case DONT:
    case WILL:
    case WONT:
        return current+3 <= endp ? current+3 : NULL;
    case SB:            /* loop forever looking for the SE */
        {
            char *look = current+2;

            while (look < endp) {
                if ((*look++&0xff) == IAC) {
                    if (look < endp && (*look++&0xff) == SE) {
                        return look;
                    }
                }
            }
            return NULL;
        }
    default:
        return current+2 <= endp ? current+2 : NULL;
    }
}  /* end of nextitem */

/*
 * 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) && \
                                (nfrontp > p+1) && ((*(p+1)&0xff) != EC) && ((*(p+1)&0xff) != EL))

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

    while ((next = nextitem(thisitem, nbackp)) != NULL && (next <= nbackp)) {
        thisitem = next;
    }

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

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

    while ((thisitem != NULL) && (nfrontp > thisitem)) {
        if (wewant(thisitem)) {
            int length;

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

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

/*
 *  netflush
 *              Send as much data as possible to the network,
 *      handling requests for urgent data.
 */
void
netflush(void)
{
    int n;
    extern int not42;

    while ((n = nfrontp - nbackp) > 0) {
#if 0
        /* XXX This causes output_data() to recurse and die */
        DIAG(TD_REPORT, {
            n += output_data("td: netflush %d chars\r\n", n);
        });
#endif
#ifdef  ENCRYPTION
        if (encrypt_output) {
                char *s = nclearto ? nclearto : nbackp;
                if (nfrontp - s > 0) {
                        (*encrypt_output)((unsigned char *)s, nfrontp-s);
                        nclearto = nfrontp;
                }
        }
#endif  /* ENCRYPTION */
        /*
         * 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 ((neturg == 0) || (not42 == 0)) {
            n = write(net, nbackp, n);  /* normal write */
        } 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 */
            }
        }
        if (n == -1) {
            if (errno == EWOULDBLOCK || errno == EINTR)
                continue;
            cleanup(0);
            /* NOTREACHED */
        }
        nbackp += n;
#ifdef  ENCRYPTION
        if (nbackp > nclearto)
            nclearto = 0;
#endif  /* ENCRYPTION */
        if (nbackp >= neturg) {
            neturg = 0;
        }
        if (nbackp == nfrontp) {
            nbackp = nfrontp = netobuf;
#ifdef  ENCRYPTION
            nclearto = 0;
#endif  /* ENCRYPTION */
        }
    }
    return;
}  /* end of netflush */


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


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

        (void) 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  /* ENCRYPTION */
        (void) write(f, buf, (int)strlen(buf));
        sleep(1);       /*XXX*/
        exit(1);
}

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

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

char editedhost[32];

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

        if (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)
                (void) strncpy(res, host,
                                sizeof editedhost - (res - editedhost) -1);
        else
                *res = '\0';
        editedhost[sizeof editedhost - 1] = '\0';
}

static char *putlocation;

static void
putstr(const char *s)
{

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

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

#ifdef __FreeBSD__
static char fmtstr[] = { "%+" };
#else
static char fmtstr[] = { "%l:%M%P on %A, %d %B %Y" };
#endif

void
putf(char *cp, char *where)
{
        char *slash;
        time_t t;
        char db[100];
#ifdef __FreeBSD__
        static struct utsname kerninfo;

        if (!*kerninfo.sysname)
                uname(&kerninfo);
#endif

        putlocation = where;

        while (*cp) {
                if (*cp =='\n') {
                        putstr("\r\n");
                        cp++;
                        continue;
                } else if (*cp != '%') {
                        putchr(*cp++);
                        continue;
                }
                switch (*++cp) {

                case 't':
#ifdef  STREAMSPTY
                        /* names are like /dev/pts/2 -- we want pts/2 */
                        slash = strchr(line+1, '/');
#else
                        slash = strrchr(line, '/');
#endif
                        if (slash == (char *) 0)
                                putstr(line);
                        else
                                putstr(&slash[1]);
                        break;

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

                case 'd':
#ifdef __FreeBSD__
                        setlocale(LC_TIME, "");
#endif
                        (void)time(&t);
                        (void)strftime(db, sizeof(db), fmtstr, localtime(&t));
                        putstr(db);
                        break;

#ifdef __FreeBSD__
                case 's':
                        putstr(kerninfo.sysname);
                        break;

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

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

                case 'v':
                        putstr(kerninfo.version);
                        break;
#endif

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

#ifdef DIAGNOSTICS
/*
 * Print telnet options and commands in plain text, if possible.
 */
void
printoption(const 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(char direction, unsigned char *pointer, int length)
{
    int i = 0;

        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\"", 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", 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(" %d %d (%d)",
                pointer[1], pointer[2],
                (int)((((unsigned int)pointer[1])<<8)|((unsigned int)pointer[2])));
            if (length == 4) {
                output_data(" ?%d?", pointer[3]);
                break;
            }
            output_data(" %d %d (%d)",
                pointer[3], pointer[4],
                (int)((((unsigned int)pointer[3])<<8)|((unsigned int)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];
                    sprintf(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: {
            const 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\"", 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 noquote = 2;
                    for (i = 2; i < length; i++ ) {
                        switch (pointer[i]) {
                        case NEW_ENV_VAR:
                            output_data("%s", "\" VAR " + noquote);
                            noquote = 2;
                            break;

                        case NEW_ENV_VALUE:
                            output_data("%s", "\" VALUE " + noquote);
                            noquote = 2;
                            break;

                        case ENV_ESC:
                            output_data("%s", "\" ESC " + noquote);
                            noquote = 2;
                            break;

                        case ENV_USERVAR:
                            output_data("%s", "\" USERVAR " + noquote);
                            noquote = 2;
                            break;

                        default:
                            if (isprint(pointer[i]) && pointer[i] != '"') {
                                if (noquote) {
                                    output_data("\"");
                                    noquote = 0;
                                }
                                output_data("%c", pointer[i]);
                            } else {
                                output_data("\" %03o " + noquote,
                                                        pointer[i]);
                                noquote = 2;
                            }
                            break;
                        }
                    }
                    if (!noquote)
                        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");

                {
                    char buf[512];
                    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:
                output_data(" NAME \"%.*s\"", length - 2, pointer + 2);
                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]);

                {
                    char buf[512];
                    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");
                goto encommon;

            case ENCRYPT_DEC_KEYID:
                output_data(" DEC_KEYID");
                goto encommon;

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

        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(const char *tag, char *ptr, int cnt)
{
        int 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(*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 */