/*
 * 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.
 */

#include "telnetd.h"

RCSID("$Id$");

#ifdef _SC_CRAY_SECURE_SYS
#include <sys/sysv.h>
#include <sys/secdev.h>
#include <sys/secparm.h>
#include <sys/usrv.h>
int     secflag;
char    tty_dev[16];
struct  secdev dv;
struct  sysv sysv;
struct  socksec ss;
#endif  /* _SC_CRAY_SECURE_SYS */

#ifdef AUTHENTICATION
int     auth_level = 0;
#endif

#ifdef KRB5
#define Authenticator k5_Authenticator
#include <krb5.h>
#undef Authenticator
#endif

extern  int utmp_len;
int     registerd_host_only = 0;
#ifdef ENCRYPTION
int     require_encryption = 0;
#endif

#ifdef STREAMSPTY

#ifdef _AIX
#include <sys/termio.h>
#endif
# ifdef HAVE_SYS_STRTTY_H
# include <sys/strtty.h>
# endif
# ifdef HAVE_SYS_STR_TTY_H
# include <sys/str_tty.h>
# endif
/* make sure we don't get the bsd version */
/* what is this here for? solaris? /joda */
# ifdef HAVE_SYS_TTY_H
# include "/usr/include/sys/tty.h"
# endif
# ifdef HAVE_SYS_PTYVAR_H
# include <sys/ptyvar.h>
# endif

/*
 * Because of the way ptyibuf is used with streams messages, we need
 * ptyibuf+1 to be on a full-word boundary.  The following wierdness
 * is simply to make that happen.
 */
long    ptyibufbuf[BUFSIZ/sizeof(long)+1];
char    *ptyibuf = ((char *)&ptyibufbuf[1])-1;
char    *ptyip = ((char *)&ptyibufbuf[1])-1;
char    ptyibuf2[BUFSIZ];
unsigned char ctlbuf[BUFSIZ];
struct  strbuf strbufc, strbufd;

int readstream(int, char*, int);

#else   /* ! STREAMPTY */

/*
 * I/O data buffers,
 * pointers, and counters.
 */
char    ptyibuf[BUFSIZ], *ptyip = ptyibuf;
char    ptyibuf2[BUFSIZ];

#endif /* ! STREAMPTY */

int     hostinfo = 1;                   /* do we print login banner? */

#ifdef  _CRAY
extern int      newmap; /* nonzero if \n maps to ^M^J */
int     lowpty = 0, highpty;    /* low, high pty numbers */
#endif /* CRAY */

int debug = 0;
int keepalive = 1;
char *progname;

static void usage (int error_code);

/*
 * The string to pass to getopt().  We do it this way so
 * that only the actual options that we support will be
 * passed off to getopt().
 */
char valid_opts[] = "Bd:hklnS:u:UL:y"
#ifdef AUTHENTICATION
                    "a:X:z"
#endif
#ifdef ENCRYPTION
                     "e"
#endif
#ifdef DIAGNOSTICS
                    "D:"
#endif
#ifdef _CRAY
                    "r:"
#endif
                    ;

static void doit(struct sockaddr*, int);

int
main(int argc, char **argv)
{
    struct sockaddr_storage __ss;
    struct sockaddr *sa = (struct sockaddr *)&__ss;
    int on = 1;
    socklen_t sa_size;
    int ch;
#if     defined(IPPROTO_IP) && defined(IP_TOS)
    int tos = -1;
#endif
    pfrontp = pbackp = ptyobuf;
    netip = netibuf;
    nfrontp = nbackp = netobuf;

    setprogname(argv[0]);

    progname = *argv;
#ifdef ENCRYPTION
    nclearto = 0;
#endif

#ifdef _CRAY
    /*
     * Get number of pty's before trying to process options,
     * which may include changing pty range.
     */
    highpty = getnpty();
#endif /* CRAY */

    if (argc == 2 && strcmp(argv[1], "--version") == 0) {
        print_version(NULL);
        exit(0);
    }
    if (argc == 2 && strcmp(argv[1], "--help") == 0)
        usage(0);

    while ((ch = getopt(argc, argv, valid_opts)) != -1) {
        switch(ch) {

#ifdef  AUTHENTICATION
        case 'a':
            /*
             * Check for required authentication level
             */
            if (strcmp(optarg, "debug") == 0) {
                auth_debug_mode = 1;
            } else if (strcasecmp(optarg, "none") == 0) {
                auth_level = 0;
            } else if (strcasecmp(optarg, "otp") == 0) {
                auth_level = 0;
                require_otp = 1;
            } else if (strcasecmp(optarg, "other") == 0) {
                auth_level = AUTH_OTHER;
            } else if (strcasecmp(optarg, "user") == 0) {
                auth_level = AUTH_USER;
            } else if (strcasecmp(optarg, "valid") == 0) {
                auth_level = AUTH_VALID;
            } else if (strcasecmp(optarg, "off") == 0) {
                /*
                 * This hack turns off authentication
                 */
                auth_level = -1;
            } else {
                fprintf(stderr,
                        "telnetd: unknown authorization level for -a\n");
            }
            break;
#endif  /* AUTHENTICATION */

        case 'B': /* BFTP mode is not supported any more */
            break;
        case 'd':
            if (strcmp(optarg, "ebug") == 0) {
                debug++;
                break;
            }
            usage(1);
            /* NOTREACHED */
            break;

#ifdef DIAGNOSTICS
        case 'D':
            /*
             * Check for desired diagnostics capabilities.
             */
            if (!strcmp(optarg, "report")) {
                diagnostic |= TD_REPORT|TD_OPTIONS;
            } else if (!strcmp(optarg, "exercise")) {
                diagnostic |= TD_EXERCISE;
            } else if (!strcmp(optarg, "netdata")) {
                diagnostic |= TD_NETDATA;
            } else if (!strcmp(optarg, "ptydata")) {
                diagnostic |= TD_PTYDATA;
            } else if (!strcmp(optarg, "options")) {
                diagnostic |= TD_OPTIONS;
            } else {
                usage(1);
                /* NOT REACHED */
            }
            break;
#endif /* DIAGNOSTICS */

#ifdef ENCRYPTION
        case 'e':
            require_encryption = 1;
            break;
#endif

        case 'h':
            hostinfo = 0;
            break;

        case 'k': /* Linemode is not supported any more */
        case 'l':
            break;

        case 'n':
            keepalive = 0;
            break;

#ifdef _CRAY
        case 'r':
            {
                char *strchr();
                char *c;

                /*
                 * Allow the specification of alterations
                 * to the pty search range.  It is legal to
                 * specify only one, and not change the
                 * other from its default.
                 */
                c = strchr(optarg, '-');
                if (c) {
                    *c++ = '\0';
                    highpty = atoi(c);
                }
                if (*optarg != '\0')
                    lowpty = atoi(optarg);
                if ((lowpty > highpty) || (lowpty < 0) ||
                    (highpty > 32767)) {
                    usage(1);
                    /* NOT REACHED */
                }
                break;
            }
#endif  /* CRAY */

        case 'S':
#ifdef  HAVE_PARSETOS
            if ((tos = parsetos(optarg, "tcp")) < 0)
                fprintf(stderr, "%s%s%s\n",
                        "telnetd: Bad TOS argument '", optarg,
                        "'; will try to use default TOS");
#else
            fprintf(stderr, "%s%s\n", "TOS option unavailable; ",
                    "-S flag not supported\n");
#endif
            break;

        case 'u': {
            char *eptr;

            utmp_len = strtol(optarg, &eptr, 0);
            if (optarg == eptr)
                fprintf(stderr, "telnetd: unknown utmp len (%s)\n", optarg);
            break;
        }

        case 'U':
            registerd_host_only = 1;
            break;

#ifdef  AUTHENTICATION
        case 'X':
            /*
             * Check for invalid authentication types
             */
            auth_disable_name(optarg);
            break;
#endif
        case 'y':
            no_warn = 1;
            break;
#ifdef AUTHENTICATION
        case 'z':
            log_unauth = 1;
            break;

#endif  /* AUTHENTICATION */

        case 'L':
            new_login = optarg;
            break;

        default:
            fprintf(stderr, "telnetd: %c: unknown option\n", ch);
            /* FALLTHROUGH */
        case '?':
            usage(0);
            /* NOTREACHED */
        }
    }

    argc -= optind;
    argv += optind;

    if (debug) {
        int port = 0;
        struct servent *sp;

        if (argc > 1) {
            usage (1);
        } else if (argc == 1) {
            sp = roken_getservbyname (*argv, "tcp");
            if (sp)
                port = sp->s_port;
            else
                port = htons(atoi(*argv));
        } else {
#ifdef KRB5
            port = krb5_getportbyname (NULL, "telnet", "tcp", 23);
#else
            port = k_getportbyname("telnet", "tcp", htons(23));
#endif
        }
        mini_inetd (port, NULL);
    } else if (argc > 0) {
        usage(1);
        /* NOT REACHED */
    }

#ifdef _SC_CRAY_SECURE_SYS
    secflag = sysconf(_SC_CRAY_SECURE_SYS);

    /*
     *  Get socket's security label
     */
    if (secflag)  {
        socklen_t szss = sizeof(ss);
        int sock_multi;
        socklen_t szi = sizeof(int);

        memset(&dv, 0, sizeof(dv));

        if (getsysv(&sysv, sizeof(struct sysv)) != 0)
            fatalperror(net, "getsysv");

        /*
         *      Get socket security label and set device values
         *         {security label to be set on ttyp device}
         */
#ifdef SO_SEC_MULTI                     /* 8.0 code */
        if ((getsockopt(0, SOL_SOCKET, SO_SECURITY,
                        (void *)&ss, &szss) < 0) ||
            (getsockopt(0, SOL_SOCKET, SO_SEC_MULTI,
                        (void *)&sock_multi, &szi) < 0))
            fatalperror(net, "getsockopt");
        else {
            dv.dv_actlvl = ss.ss_actlabel.lt_level;
            dv.dv_actcmp = ss.ss_actlabel.lt_compart;
            if (!sock_multi) {
                dv.dv_minlvl = dv.dv_maxlvl = dv.dv_actlvl;
                dv.dv_valcmp = dv.dv_actcmp;
            } else {
                dv.dv_minlvl = ss.ss_minlabel.lt_level;
                dv.dv_maxlvl = ss.ss_maxlabel.lt_level;
                dv.dv_valcmp = ss.ss_maxlabel.lt_compart;
            }
            dv.dv_devflg = 0;
        }
#else /* SO_SEC_MULTI */                /* 7.0 code */
        if (getsockopt(0, SOL_SOCKET, SO_SECURITY,
                       (void *)&ss, &szss) >= 0) {
            dv.dv_actlvl = ss.ss_slevel;
            dv.dv_actcmp = ss.ss_compart;
            dv.dv_minlvl = ss.ss_minlvl;
            dv.dv_maxlvl = ss.ss_maxlvl;
            dv.dv_valcmp = ss.ss_maxcmp;
        }
#endif /* SO_SEC_MULTI */
    }
#endif  /* _SC_CRAY_SECURE_SYS */

    roken_openlog("telnetd", LOG_PID | LOG_ODELAY, LOG_DAEMON);
    sa_size = sizeof (__ss);
    if (getpeername(STDIN_FILENO, sa, &sa_size) < 0) {
        fprintf(stderr, "%s: ", progname);
        perror("getpeername");
        _exit(1);
    }
    if (keepalive &&
        setsockopt(STDIN_FILENO, SOL_SOCKET, SO_KEEPALIVE,
                   (void *)&on, sizeof (on)) < 0) {
        syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
    }

#if     defined(IPPROTO_IP) && defined(IP_TOS) && defined(HAVE_SETSOCKOPT)
    {
# ifdef HAVE_GETTOSBYNAME
        struct tosent *tp;
        if (tos < 0 && (tp = gettosbyname("telnet", "tcp")))
            tos = tp->t_tos;
# endif
        if (tos < 0)
            tos = 020;  /* Low Delay bit */
        if (tos
            && sa->sa_family == AF_INET
            && (setsockopt(STDIN_FILENO, IPPROTO_IP, IP_TOS,
                           (void *)&tos, sizeof(tos)) < 0)
            && (errno != ENOPROTOOPT) )
            syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
    }
#endif  /* defined(IPPROTO_IP) && defined(IP_TOS) */
    net = STDIN_FILENO;
    doit(sa, sa_size);
    /* NOTREACHED */
    return 0;
}  /* end of main */

static void
usage(int exit_code)
{
    fprintf(stderr, "Usage: telnetd");
    fprintf(stderr, " [--help]");
    fprintf(stderr, " [--version]");
#ifdef  AUTHENTICATION
    fprintf(stderr, " [-a (debug|other|otp|user|valid|off|none)]\n\t");
#endif
    fprintf(stderr, " [-debug]");
#ifdef DIAGNOSTICS
    fprintf(stderr, " [-D (options|report|exercise|netdata|ptydata)]\n\t");
#endif
#ifdef  AUTHENTICATION
    fprintf(stderr, " [-edebug]");
#endif
    fprintf(stderr, " [-h]");
    fprintf(stderr, " [-L login]");
    fprintf(stderr, " [-n]");
#ifdef  _CRAY
    fprintf(stderr, " [-r[lowpty]-[highpty]]");
#endif
    fprintf(stderr, "\n\t");
#ifdef  HAVE_GETTOSBYNAME
    fprintf(stderr, " [-S tos]");
#endif
#ifdef  AUTHENTICATION
    fprintf(stderr, " [-X auth-type] [-y] [-z]");
#endif
    fprintf(stderr, " [-u utmp_hostname_length] [-U]");
    fprintf(stderr, " [port]\n");
    exit(exit_code);
}

/*
 * getterminaltype
 *
 *      Ask the other end to send along its terminal type and speed.
 * Output is the variable terminaltype filled in.
 */
static unsigned char ttytype_sbbuf[] = {
    IAC, SB, TELOPT_TTYPE, TELQUAL_SEND, IAC, SE
};

int
getterminaltype(char *name, size_t name_sz)
{
    int retval = -1;

    settimer(baseline);
#ifdef AUTHENTICATION
    /*
     * Handle the Authentication option before we do anything else.
     */
    send_do(TELOPT_AUTHENTICATION, 1);
    while (his_will_wont_is_changing(TELOPT_AUTHENTICATION))
        ttloop();
    if (his_state_is_will(TELOPT_AUTHENTICATION)) {
        retval = auth_wait(name, name_sz);
    }
#endif

#ifdef ENCRYPTION
    send_will(TELOPT_ENCRYPT, 1);
    send_do(TELOPT_ENCRYPT, 1); /* esc@magic.fi */
#endif
    send_do(TELOPT_TTYPE, 1);
    send_do(TELOPT_TSPEED, 1);
    send_do(TELOPT_XDISPLOC, 1);
    send_do(TELOPT_NEW_ENVIRON, 1);
    send_do(TELOPT_OLD_ENVIRON, 1);
    while (
#ifdef ENCRYPTION
           his_do_dont_is_changing(TELOPT_ENCRYPT) ||
#endif
           his_will_wont_is_changing(TELOPT_TTYPE) ||
           his_will_wont_is_changing(TELOPT_TSPEED) ||
           his_will_wont_is_changing(TELOPT_XDISPLOC) ||
           his_will_wont_is_changing(TELOPT_NEW_ENVIRON) ||
           his_will_wont_is_changing(TELOPT_OLD_ENVIRON)) {
        ttloop();
    }
#ifdef ENCRYPTION
    /*
     * Wait for the negotiation of what type of encryption we can
     * send with.  If autoencrypt is not set, this will just return.
     */
    if (his_state_is_will(TELOPT_ENCRYPT)) {
        encrypt_wait();
    }
    if (require_encryption) {

        while (encrypt_delay())
            if (telnet_spin())
                fatal(net, "Failed while waiting for encryption");

        if (!encrypt_is_encrypting())
            fatal(net, "Encryption required but not turned on by client");
    }
#endif
    if (his_state_is_will(TELOPT_TSPEED)) {
        static unsigned char sb[] =
        { IAC, SB, TELOPT_TSPEED, TELQUAL_SEND, IAC, SE };

        telnet_net_write (sb, sizeof sb);
        DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
    }
    if (his_state_is_will(TELOPT_XDISPLOC)) {
        static unsigned char sb[] =
        { IAC, SB, TELOPT_XDISPLOC, TELQUAL_SEND, IAC, SE };

        telnet_net_write (sb, sizeof sb);
        DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
    }
    if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
        static unsigned char sb[] =
        { IAC, SB, TELOPT_NEW_ENVIRON, TELQUAL_SEND, IAC, SE };

        telnet_net_write (sb, sizeof sb);
        DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
    }
    else if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
        static unsigned char sb[] =
        { IAC, SB, TELOPT_OLD_ENVIRON, TELQUAL_SEND, IAC, SE };

        telnet_net_write (sb, sizeof sb);
        DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
    }
    if (his_state_is_will(TELOPT_TTYPE)) {

        telnet_net_write (ttytype_sbbuf, sizeof ttytype_sbbuf);
        DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
                                  sizeof ttytype_sbbuf - 2););
    }
    if (his_state_is_will(TELOPT_TSPEED)) {
        while (sequenceIs(tspeedsubopt, baseline))
            ttloop();
    }
    if (his_state_is_will(TELOPT_XDISPLOC)) {
        while (sequenceIs(xdisplocsubopt, baseline))
            ttloop();
    }
    if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
        while (sequenceIs(environsubopt, baseline))
            ttloop();
    }
    if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
        while (sequenceIs(oenvironsubopt, baseline))
            ttloop();
    }
    if (his_state_is_will(TELOPT_TTYPE)) {
        char first[256], last[256];

        while (sequenceIs(ttypesubopt, baseline))
            ttloop();

        /*
         * If the other side has already disabled the option, then
         * we have to just go with what we (might) have already gotten.
         */
        if (his_state_is_will(TELOPT_TTYPE) && !terminaltypeok(terminaltype)) {
            strlcpy(first, terminaltype, sizeof(first));
            for(;;) {
                /*
                 * Save the unknown name, and request the next name.
                 */
                strlcpy(last, terminaltype, sizeof(last));
                _gettermname();
                if (terminaltypeok(terminaltype))
                    break;
                if ((strncmp(last, terminaltype, sizeof(last)) == 0) ||
                    his_state_is_wont(TELOPT_TTYPE)) {
                    /*
                     * We've hit the end.  If this is the same as
                     * the first name, just go with it.
                     */
                    if (strncmp(first, terminaltype, sizeof(first)) == 0)
                        break;
                    /*
                     * Get the terminal name one more time, so that
                     * RFC1091 compliant telnets will cycle back to
                     * the start of the list.
                     */
                    _gettermname();
                    if (strncmp(first, terminaltype, sizeof(first)) != 0)
                        strlcpy(terminaltype, first, sizeof(terminaltype));
                    break;
                }
            }
        }
    }
    return(retval);
}  /* end of getterminaltype */

void
_gettermname(void)
{
    /*
     * If the client turned off the option,
     * we can't send another request, so we
     * just return.
     */
    if (his_state_is_wont(TELOPT_TTYPE))
        return;
    settimer(baseline);
    telnet_net_write (ttytype_sbbuf, sizeof ttytype_sbbuf);
    DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
                              sizeof ttytype_sbbuf - 2););
    while (sequenceIs(ttypesubopt, baseline))
        ttloop();
}

int
terminaltypeok(char *s)
{
    return 1;
}


char host_name[MaxHostNameLen];
char remote_host_name[MaxHostNameLen];
char remote_utmp_name[MaxHostNameLen];

/*
 * Get a pty, scan input lines.
 */
static void
doit(struct sockaddr *who, int who_len)
{
    int level;
    int ptynum;
    char user_name[256];
    int error;

    /*
     * Find an available pty to use.
     */
    ourpty = getpty(&ptynum);
    if (ourpty < 0)
        fatal(net, "All network ports in use");

#ifdef _SC_CRAY_SECURE_SYS
    /*
     *  set ttyp line security label
     */
    if (secflag) {
        char slave_dev[16];

        snprintf(tty_dev, sizeof(tty_dev), "/dev/pty/%03d", ptynum);
        if (setdevs(tty_dev, &dv) < 0)
            fatal(net, "cannot set pty security");
        snprintf(slave_dev, sizeof(slave_dev), "/dev/ttyp%03d", ptynum);
        if (setdevs(slave_dev, &dv) < 0)
            fatal(net, "cannot set tty security");
    }
#endif  /* _SC_CRAY_SECURE_SYS */

    error = getnameinfo_verified (who, who_len,
                                  remote_host_name,
                                  sizeof(remote_host_name),
                                  NULL, 0,
                                  registerd_host_only ? NI_NAMEREQD : 0);
    if (error)
        fatal(net, "Couldn't resolve your address into a host name.\r\n\
Please contact your net administrator");

    gethostname(host_name, sizeof (host_name));

    strlcpy (remote_utmp_name, remote_host_name, sizeof(remote_utmp_name));

    /* Only trim if too long (and possible) */
    if (strlen(remote_utmp_name) > utmp_len) {
        char *domain = strchr(host_name, '.');
        char *p = strchr(remote_utmp_name, '.');
        if (domain != NULL && p != NULL && (strcmp(p, domain) == 0))
            *p = '\0'; /* remove domain part */
    }

    /*
     * If hostname still doesn't fit utmp, use ipaddr.
     */
    if (strlen(remote_utmp_name) > utmp_len) {
        error = getnameinfo (who, who_len,
                             remote_utmp_name,
                             sizeof(remote_utmp_name),
                             NULL, 0,
                             NI_NUMERICHOST);
        if (error)
            fatal(net, "Couldn't get numeric address\r\n");
    }

#ifdef AUTHENTICATION
    auth_encrypt_init(host_name, remote_host_name, "TELNETD", 1);
#endif

    init_env();

    /* begin server processing */

    /*
     * Initialize the slc mapping table.
     */

    get_slc_defaults();

    /*
     * get terminal type.
     */
    *user_name = 0;
    level = getterminaltype(user_name, sizeof(user_name));
    esetenv("TERM", terminaltype[0] ? terminaltype : "network", 1);

#ifdef _SC_CRAY_SECURE_SYS
    if (secflag) {
        if (setulvl(dv.dv_actlvl) < 0)
            fatal(net,"cannot setulvl()");
        if (setucmp(dv.dv_actcmp) < 0)
            fatal(net, "cannot setucmp()");
    }
#endif  /* _SC_CRAY_SECURE_SYS */

    my_telnet(net, ourpty, remote_host_name, remote_utmp_name,
              level, user_name);
    /*NOTREACHED*/
}  /* end of doit */

/* output contents of /etc/issue.net, or /etc/issue */
static void
show_issue(void)
{
    FILE *f;
    char buf[128];
    f = fopen(SYSCONFDIR "/issue.net", "r");
    if(f == NULL)
        f = fopen(SYSCONFDIR "/issue", "r");
    if(f){
        while(fgets(buf, sizeof(buf), f) != NULL) {
            size_t len = strcspn(buf, "\r\n");
            if(len == strlen(buf)) {
                /* there's no newline */
                writenet(buf, len);
            } else {
                /* replace newline with \r\n */
                buf[len] = '\0';
                writenet(buf, len);
                writenet("\r\n", 2);
            }
        }
        fclose(f);
    }
}

/*
 * Main loop.  Select from pty and network, and
 * hand data to telnet receiver finite state machine.
 */
void
my_telnet(int f, int p, const char *host, const char *utmp_host,
          int level, char *autoname)
{
    int on = 1;
    char *he;
    char *IM;
    int nfd;
    int startslave_called = 0;
    time_t timeout;

    /*
     * Do some tests where it is desireable to wait for a response.
     * Rather than doing them slowly, one at a time, do them all
     * at once.
     */
    if (my_state_is_wont(TELOPT_SGA))
        send_will(TELOPT_SGA, 1);
    /*
     * Is the client side a 4.2 (NOT 4.3) system?  We need to know this
     * because 4.2 clients are unable to deal with TCP urgent data.
     *
     * To find out, we send out a "DO ECHO".  If the remote system
     * answers "WILL ECHO" it is probably a 4.2 client, and we note
     * that fact ("WILL ECHO" ==> that the client will echo what
     * WE, the server, sends it; it does NOT mean that the client will
     * echo the terminal input).
     */
    send_do(TELOPT_ECHO, 1);

    /*
     * Send along a couple of other options that we wish to negotiate.
     */
    send_do(TELOPT_NAWS, 1);
    send_will(TELOPT_STATUS, 1);
    flowmode = 1;               /* default flow control state */
    restartany = -1;    /* uninitialized... */
    send_do(TELOPT_LFLOW, 1);

    /*
     * Spin, waiting for a response from the DO ECHO.  However,
     * some REALLY DUMB telnets out there might not respond
     * to the DO ECHO.  So, we spin looking for NAWS, (most dumb
     * telnets so far seem to respond with WONT for a DO that
     * they don't understand...) because by the time we get the
     * response, it will already have processed the DO ECHO.
     * Kludge upon kludge.
     */
    while (his_will_wont_is_changing(TELOPT_NAWS))
        ttloop();

    /*
     * But...
     * The client might have sent a WILL NAWS as part of its
     * startup code; if so, we'll be here before we get the
     * response to the DO ECHO.  We'll make the assumption
     * that any implementation that understands about NAWS
     * is a modern enough implementation that it will respond
     * to our DO ECHO request; hence we'll do another spin
     * waiting for the ECHO option to settle down, which is
     * what we wanted to do in the first place...
     */
    if (his_want_state_is_will(TELOPT_ECHO) &&
        his_state_is_will(TELOPT_NAWS)) {
        while (his_will_wont_is_changing(TELOPT_ECHO))
            ttloop();
    }
    /*
     * On the off chance that the telnet client is broken and does not
     * respond to the DO ECHO we sent, (after all, we did send the
     * DO NAWS negotiation after the DO ECHO, and we won't get here
     * until a response to the DO NAWS comes back) simulate the
     * receipt of a will echo.  This will also send a WONT ECHO
     * to the client, since we assume that the client failed to
     * respond because it believes that it is already in DO ECHO
     * mode, which we do not want.
     */
    if (his_want_state_is_will(TELOPT_ECHO)) {
        DIAG(TD_OPTIONS,
             {output_data("td: simulating recv\r\n");
             });
        willoption(TELOPT_ECHO);
    }

    /*
     * Finally, to clean things up, we turn on our echo.  This
     * will break stupid 4.2 telnets out of local terminal echo.
     */

    if (my_state_is_wont(TELOPT_ECHO))
        send_will(TELOPT_ECHO, 1);

#ifdef TIOCPKT
#ifdef  STREAMSPTY
    if (!really_stream)
#endif
        /*
         * Turn on packet mode
         */
        ioctl(p, TIOCPKT, (char *)&on);
#endif


    /*
     * Call telrcv() once to pick up anything received during
     * terminal type negotiation, 4.2/4.3 determination, and
     * linemode negotiation.
     */
    telrcv();

    ioctl(f, FIONBIO, (char *)&on);
    ioctl(p, FIONBIO, (char *)&on);

#if     defined(SO_OOBINLINE) && defined(HAVE_SETSOCKOPT)
    setsockopt(net, SOL_SOCKET, SO_OOBINLINE,
               (void *)&on, sizeof on);
#endif  /* defined(SO_OOBINLINE) */

#ifdef  SIGTSTP
    signal(SIGTSTP, SIG_IGN);
#endif
#ifdef  SIGTTOU
    /*
     * Ignoring SIGTTOU keeps the kernel from blocking us
     * in ttioct() in /sys/tty.c.
     */
    signal(SIGTTOU, SIG_IGN);
#endif

    signal(SIGCHLD, cleanup);

#ifdef  TIOCNOTTY
    {
        int t;
        t = open(_PATH_TTY, O_RDWR);
        if (t >= 0) {
            ioctl(t, TIOCNOTTY, (char *)0);
            close(t);
        }
    }
#endif

    show_issue();
    /*
     * Show banner that getty never gave.
     *
     * We put the banner in the pty input buffer.  This way, it
     * gets carriage return null processing, etc., just like all
     * other pty --> client data.
     */

    if (getenv("USER"))
        hostinfo = 0;

    IM = DEFAULT_IM;
    he = 0;
    edithost(he, host_name);
    if (hostinfo && *IM)
        putf(IM, ptyibuf2);

    if (pcc)
        strncat(ptyibuf2, ptyip, pcc+1);
    ptyip = ptyibuf2;
    pcc = strlen(ptyip);

    DIAG(TD_REPORT, {
        output_data("td: Entering processing loop\r\n");
    });


    nfd = ((f > p) ? f : p) + 1;
    timeout = time(NULL) + 5;
    for (;;) {
        fd_set ibits, obits, xbits;
        int c;

        /* wait for encryption to be turned on, but don't wait
           indefinitely */
        if(!startslave_called && (!encrypt_delay() || timeout > time(NULL))){
            startslave_called = 1;
            startslave(host, utmp_host, level, autoname);
        }

        if (ncc < 0 && pcc < 0)
            break;

        FD_ZERO(&ibits);
        FD_ZERO(&obits);
        FD_ZERO(&xbits);

        if (f >= FD_SETSIZE
            || p >= FD_SETSIZE)
            fatal(net, "fd too large");

        /*
         * Never look for input if there's still
         * stuff in the corresponding output buffer
         */
        if (nfrontp - nbackp || pcc > 0) {
            FD_SET(f, &obits);
        } else {
            FD_SET(p, &ibits);
        }
        if (pfrontp - pbackp || ncc > 0) {
            FD_SET(p, &obits);
        } else {
            FD_SET(f, &ibits);
        }
        if (!SYNCHing) {
            FD_SET(f, &xbits);
        }
        if ((c = select(nfd, &ibits, &obits, &xbits,
                        (struct timeval *)0)) < 1) {
            if (c == -1) {
                if (errno == EINTR) {
                    continue;
                }
            }
            sleep(5);
            continue;
        }

        /*
         * Any urgent data?
         */
        if (FD_ISSET(net, &xbits)) {
            SYNCHing = 1;
        }

        /*
         * Something to read from the network...
         */
        if (FD_ISSET(net, &ibits)) {
#ifndef SO_OOBINLINE
            /*
             * In 4.2 (and 4.3 beta) systems, the
             * OOB indication and data handling in the kernel
             * is such that if two separate TCP Urgent requests
             * come in, one byte of TCP data will be overlaid.
             * This is fatal for Telnet, but we try to live
             * with it.
             *
             * In addition, in 4.2 (and...), a special protocol
             * is needed to pick up the TCP Urgent data in
             * the correct sequence.
             *
             * What we do is:  if we think we are in urgent
             * mode, we look to see if we are "at the mark".
             * If we are, we do an OOB receive.  If we run
             * this twice, we will do the OOB receive twice,
             * but the second will fail, since the second
             * time we were "at the mark", but there wasn't
             * any data there (the kernel doesn't reset
             * "at the mark" until we do a normal read).
             * Once we've read the OOB data, we go ahead
             * and do normal reads.
             *
             * There is also another problem, which is that
             * since the OOB byte we read doesn't put us
             * out of OOB state, and since that byte is most
             * likely the TELNET DM (data mark), we would
             * stay in the TELNET SYNCH (SYNCHing) state.
             * So, clocks to the rescue.  If we've "just"
             * received a DM, then we test for the
             * presence of OOB data when the receive OOB
             * fails (and AFTER we did the normal mode read
             * to clear "at the mark").
             */
            if (SYNCHing) {
                int atmark;

                ioctl(net, SIOCATMARK, (char *)&atmark);
                if (atmark) {
                    ncc = recv(net, netibuf, sizeof (netibuf), MSG_OOB);
                    if ((ncc == -1) && (errno == EINVAL)) {
                        ncc = read(net, netibuf, sizeof (netibuf));
                        if (sequenceIs(didnetreceive, gotDM)) {
                            SYNCHing = stilloob(net);
                        }
                    }
                } else {
                    ncc = read(net, netibuf, sizeof (netibuf));
                }
            } else {
                ncc = read(net, netibuf, sizeof (netibuf));
            }
            settimer(didnetreceive);
#else   /* !defined(SO_OOBINLINE)) */
            ncc = read(net, netibuf, sizeof (netibuf));
#endif  /* !defined(SO_OOBINLINE)) */
            if (ncc < 0 && errno == EWOULDBLOCK)
                ncc = 0;
            else {
                if (ncc <= 0) {
                    break;
                }
                netip = netibuf;
            }
            DIAG((TD_REPORT | TD_NETDATA), {
                output_data("td: netread %d chars\r\n", ncc);
                });
            DIAG(TD_NETDATA, printdata("nd", netip, ncc));
        }

        /*
         * Something to read from the pty...
         */
        if (FD_ISSET(p, &ibits)) {
#ifdef STREAMSPTY
            if (really_stream)
                pcc = readstream(p, ptyibuf, BUFSIZ);
            else
#endif
                pcc = read(p, ptyibuf, BUFSIZ);

            /*
             * On some systems, if we try to read something
             * off the master side before the slave side is
             * opened, we get EIO.
             */
            if (pcc < 0 && (errno == EWOULDBLOCK ||
#ifdef  EAGAIN
                            errno == EAGAIN ||
#endif
                            errno == EIO)) {
                pcc = 0;
            } else {
                if (pcc <= 0)
                    break;
                if (ptyibuf[0] & TIOCPKT_FLUSHWRITE) {
                    netclear(); /* clear buffer back */
#ifndef NO_URGENT
                    /*
                     * There are client telnets on some
                     * operating systems get screwed up
                     * royally if we send them urgent
                     * mode data.
                     */
                    output_data ("%c%c", IAC, DM);

                    neturg = nfrontp-1; /* off by one XXX */
                    DIAG(TD_OPTIONS,
                         printoption("td: send IAC", DM));

#endif
                }
                if (his_state_is_will(TELOPT_LFLOW) &&
                    (ptyibuf[0] &
                     (TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))) {
                    int newflow =
                        ptyibuf[0] & TIOCPKT_DOSTOP ? 1 : 0;
                    if (newflow != flowmode) {
                        flowmode = newflow;
                        output_data("%c%c%c%c%c%c",
                                    IAC, SB, TELOPT_LFLOW,
                                    flowmode ? LFLOW_ON
                                    : LFLOW_OFF,
                                    IAC, SE);
                        DIAG(TD_OPTIONS, printsub('>',
                                                  (unsigned char *)nfrontp-4,
                                                  4););
                    }
                }
                pcc--;
                ptyip = ptyibuf+1;
            }
        }

        while (pcc > 0) {
            if ((&netobuf[BUFSIZ] - nfrontp) < 3)
                break;
            c = *ptyip++ & 0377, pcc--;
            if (c == IAC)
                *nfrontp++ = c;
            *nfrontp++ = c;
            if ((c == '\r') && (my_state_is_wont(TELOPT_BINARY))) {
                if (pcc > 0 && ((*ptyip & 0377) == '\n')) {
                    *nfrontp++ = *ptyip++ & 0377;
                    pcc--;
                } else
                    *nfrontp++ = '\0';
            }
        }

        if (FD_ISSET(f, &obits) && (nfrontp - nbackp) > 0)
            netflush();
        if (ncc > 0)
            telrcv();
        if (FD_ISSET(p, &obits) && (pfrontp - pbackp) > 0)
            ptyflush();
    }
    cleanup(0);
}

#ifndef TCSIG
# ifdef TIOCSIG
#  define TCSIG TIOCSIG
# endif
#endif

#ifdef  STREAMSPTY

    int flowison = -1;  /* current state of flow: -1 is unknown */

int
readstream(int p, char *ibuf, int bufsize)
{
    int flags = 0;
    int ret = 0;
    struct termios *tsp;
#if 0
    struct termio *tp;
#endif
    struct iocblk *ip;
    char vstop, vstart;
    int ixon;
    int newflow;

    strbufc.maxlen = BUFSIZ;
    strbufc.buf = (char *)ctlbuf;
    strbufd.maxlen = bufsize-1;
    strbufd.len = 0;
    strbufd.buf = ibuf+1;
    ibuf[0] = 0;

    ret = getmsg(p, &strbufc, &strbufd, &flags);
    if (ret < 0)  /* error of some sort -- probably EAGAIN */
        return(-1);

    if (strbufc.len <= 0 || ctlbuf[0] == M_DATA) {
        /* data message */
        if (strbufd.len > 0) {                  /* real data */
            return(strbufd.len + 1);    /* count header char */
        } else {
            /* nothing there */
            errno = EAGAIN;
            return(-1);
        }
    }

    /*
     * It's a control message.  Return 1, to look at the flag we set
     */

    switch (ctlbuf[0]) {
    case M_FLUSH:
        if (ibuf[1] & FLUSHW)
            ibuf[0] = TIOCPKT_FLUSHWRITE;
        return(1);

    case M_IOCTL:
        ip = (struct iocblk *) (ibuf+1);

        switch (ip->ioc_cmd) {
#ifdef TCSETS
        case TCSETS:
        case TCSETSW:
        case TCSETSF:
            tsp = (struct termios *)
                (ibuf+1 + sizeof(struct iocblk));
            vstop = tsp->c_cc[VSTOP];
            vstart = tsp->c_cc[VSTART];
            ixon = tsp->c_iflag & IXON;
            break;
#endif
#if 0
        case TCSETA:
        case TCSETAW:
        case TCSETAF:
            tp = (struct termio *) (ibuf+1 + sizeof(struct iocblk));
            vstop = tp->c_cc[VSTOP];
            vstart = tp->c_cc[VSTART];
            ixon = tp->c_iflag & IXON;
            break;
#endif
        default:
            errno = EAGAIN;
            return(-1);
        }

        newflow =  (ixon && (vstart == 021) && (vstop == 023)) ? 1 : 0;
        if (newflow != flowison) {  /* it's a change */
            flowison = newflow;
            ibuf[0] = newflow ? TIOCPKT_DOSTOP : TIOCPKT_NOSTOP;
            return(1);
        }
    }

    /* nothing worth doing anything about */
    errno = EAGAIN;
    return(-1);
}
#endif /* STREAMSPTY */

/*
 * Send interrupt to process on other side of pty.
 * If it is in raw mode, just write NULL;
 * otherwise, write intr char.
 */
void
interrupt()
{
    ptyflush(); /* half-hearted */

#if defined(STREAMSPTY) && defined(TIOCSIGNAL)
    /* Streams PTY style ioctl to post a signal */
    if (really_stream)
        {
            int sig = SIGINT;
            ioctl(ourpty, TIOCSIGNAL, &sig);
            ioctl(ourpty, I_FLUSH, FLUSHR);
        }
#else
#ifdef  TCSIG
    ioctl(ourpty, TCSIG, (char *)SIGINT);
#else   /* TCSIG */
    init_termbuf();
    *pfrontp++ = slctab[SLC_IP].sptr ?
        (unsigned char)*slctab[SLC_IP].sptr : '\177';
#endif  /* TCSIG */
#endif
}

/*
 * Send quit to process on other side of pty.
 * If it is in raw mode, just write NULL;
 * otherwise, write quit char.
 */
void
sendbrk()
{
    ptyflush(); /* half-hearted */
#ifdef  TCSIG
    ioctl(ourpty, TCSIG, (char *)SIGQUIT);
#else   /* TCSIG */
    init_termbuf();
    *pfrontp++ = slctab[SLC_ABORT].sptr ?
        (unsigned char)*slctab[SLC_ABORT].sptr : '\034';
#endif  /* TCSIG */
}

void
sendsusp()
{
#ifdef  SIGTSTP
    ptyflush(); /* half-hearted */
# ifdef TCSIG
    ioctl(ourpty, TCSIG, (char *)SIGTSTP);
# else  /* TCSIG */
    *pfrontp++ = slctab[SLC_SUSP].sptr ?
        (unsigned char)*slctab[SLC_SUSP].sptr : '\032';
# endif /* TCSIG */
#endif  /* SIGTSTP */
}

/*
 * When we get an AYT, if ^T is enabled, use that.  Otherwise,
 * just send back "[Yes]".
 */
void
recv_ayt()
{
#if     defined(SIGINFO) && defined(TCSIG)
    if (slctab[SLC_AYT].sptr && *slctab[SLC_AYT].sptr != _POSIX_VDISABLE) {
        ioctl(ourpty, TCSIG, (char *)SIGINFO);
        return;
    }
#endif
    output_data("\r\n[Yes]\r\n");
}

void
doeof()
{
    init_termbuf();

    *pfrontp++ = slctab[SLC_EOF].sptr ?
        (unsigned char)*slctab[SLC_EOF].sptr : '\004';
}