Logo Search packages:      
Sourcecode: heimdal version File versions

telnetd.c

/*
 * 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: telnetd.c,v 1.69.6.1 2004/03/22 18:17:25 lha Exp $");

#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

extern      int utmp_len;
int   registerd_host_only = 0;

#undef NOERROR

#ifdef      STREAMSPTY
# include <stropts.h>
# include <termios.h>
#ifdef HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif /* HAVE_SYS_UIO_H */
#ifdef HAVE_SYS_STREAM_H
#include <sys/stream.h>
#endif

#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 (void);

/*
 * 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 DIAGNOSTICS
                "D:"
#endif
#ifdef _CRAY
                "r:"
#endif
                ;

static void doit(struct sockaddr*, int);

#ifdef ENCRYPTION
extern int des_check_key;
#endif

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
#ifdef ENCRYPTION
    des_check_key = 1;  /* Kludge for Mac NCSA telnet 2.6 /bg */
#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);
    }

    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();
          /* 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();
            /* NOT REACHED */
          }
          break;
#endif /* DIAGNOSTICS */


      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();
                /* 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();
          /* NOTREACHED */
      }
    }

    argc -= optind;
    argv += optind;

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

      if (argc > 1) {
          usage ();
      } 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);
    } else if (argc > 0) {
      usage();
      /* 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(void)
{
    fprintf(stderr, "Usage: telnetd");
#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(1);
}

/*
 * 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();
    }
#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)
                  strcpy(terminaltype, first);
                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();
    /*
     * get terminal type.
     */
    *user_name = 0;
    level = getterminaltype(user_name, sizeof(user_name));
    esetenv("TERM", terminaltype ? 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 */

    /* begin server processing */
    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)-2, f)){
          strcpy(buf + strcspn(buf, "\r\n"), "\r\n");
          writenet((unsigned char*)buf, strlen(buf));
      }
      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;

    /*
     * Initialize the slc mapping table.
     */
    get_slc_defaults();

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

    /*
     * 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';
}

Generated by  Doxygen 1.6.0   Back to index