Columbia Kermit/kermit.zip/archives/ckc190.zip/ckvtio.c

C/C++ Source or Header | 1994-10-03 | 98KB | 3,047 lines

#ifndef VMS
# error -- CKVTIO.C is used only on the VMS(tm) or OpenVMS(tm) Operating System
#endif /* VMS */

#ifdef __ALPHA
# define CKVTIO_OS_ARCH_STRING " OpenVMS(tm) AXP(tm)";
#else
# ifdef VAX
#  module ckvtio "2.0-077"
#  define CKVTIO_OS_ARCH_STRING " OpenVMS(tm) VAX(tm)";
# else
#  ifdef __GNUC__
#   define CKVTIO_OS_ARCH_STRING " OpenVMS(tm) VAX(tm) (GCC)";
#  else
#   error -- CKVTIO.C unknown architecture, neither VAX(tm) nor AXP(tm)
#  endif /* __GNUC__ */
# endif /* VAX */
#endif /* __ALPHA */
/*
  Module version number and date.
  Also update the module number above accordingly.
*/
char *ckxv = "Communications I/O 2.0(077), 22 Sep 94";
/*
  This is the default architecture and operating system herald string.
  It is redetermined dynamically in sysinit() below.
*/
char *ckxsys = CKVTIO_OS_ARCH_STRING;

/*  C K V T I O  --  Terminal and Interrupt Functions for VAX/VMS  */

/* C-Kermit interrupt, terminal control & i/o functions for VMS systems */

/*
  Author: Frank da Cruz ([e-mail], [e-mail]),
  Columbia University Academic Information Systems, New York City.

  Copyright (C) 1985, 1994, Trustees of Columbia University in the City of New
  York.  The C-Kermit software may not be, in whole or in part, licensed or
  sold for profit as a software product itself, nor may it be included in or
  distributed with commercial products or otherwise distributed by commercial
  concerns to their clients or customers without written permission of the
  Office of Kermit Development and Distribution, Columbia University.  This
  copyright notice must not be removed, altered, or obscured.
*/

/* Edit History
 *
 * Originally adapted to VMS by:
 * Stew Rubenstein, Harvard University Chemical Labs, 1985.
 *
 * Cast of characters:
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * wb  William Bader     Lehigh University
 * mab Mark Buda         Digital (DEC)
 * fdc Frank da Cruz     Columbia U
 * HG  Hunter Goatley    Western Kentucky University
 * jh  James Harvey      Indiana / Purdue University
 * ttj Tarjei T. Jensen  Norwegian Hydrographic Service
 * tmk Terry Kennedy     Saint Peters College
 * MM  Martin Minow      Digital
 * mlo Mike O'Malley     Digital
 * DS  Dan Schullman     Digital
 * js  James Sturdevant
 * LT  Lee Tibbert       Digital
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * 006  8-May-85 MM   Got rid of "typeahead buffer" code as it didn't
 *              solve the problem of data overruns at 4800 Baud.
 *              Added vms "read a char" routine that checks for
 *              CTRL/C, CTRL/Z, etc.
 * 007 16-May-85 fdc  Changed calling convention of ttopen(), make it
 *                    set value of its argument "lcl", to tell whether
 *                    C-Kermit is in local or remote mode.
 * 008 11 Jun 85 MM   Fix definition of CTTNAM
 * 009 18 Jun 85 fdc  Move def of CTTNAM to ckcdeb.h so it can be shared.
 * 010 25 Jun 85 MM   Added sysinit() to open console.
 * 011  5 Jul 85 DS   Treat hangup of closed line as success.
 * 012 11 Jul 85 fdc  Add gtimer(), rtimer() for timing statistics.
 * 013 14 Sep 87 fdc  Add parity strip to ttinl(), add syscleanup().
 * 014 14 Feb 89 mab  Make break REALLY work.  Add IOSB's to all QIO's.
 * 015 26 Feb 89 mab  Add dcl exit handler and minor cleanup
 * 016 23-Mar-89 mab  Add IO$M_BREAKTHRU to IO$_WRITEVBLK.
 *              Add zchkspd() function to check for valid speed.
 * 017 04-Apr-89 mab  Fix some minor bugs to local/remote code
 * 018 23-Apr-89 mab  Add some of Valerie Mates' parity changes.
 * 019 25-Apr-89 mab  Change baud to 110 for V4.x break routine as
 *               50 baud is not supported on most Muxes by VMS.
 * 020 13-Jun-89 mab  Fix on exquota problem on qiow(readvblk)
 * 021 08-Jul-89 mab  Add ^C/^Y abort server mode code.
 * 022 11-May-90 mab  Add V5A code
 * 023 20-Jul-90 wb   Add support for old VAX C and VMS versions
 * 024 22-Sep-90 wb   Fixes to cps/bps confusion
 * 025 26-Sep-90 tmk  Fix the ztime() function
 * 026 29-Sep-90 tmk  Edit 024 cause a server command to give some blither-
 *              ings about unsupported line speeds.  Added a simple hack
 *              to exit quietly if the passed speed is 0.  Adventurous
 *              maintainers may want to look in ttpkt(), where ttsspd()
 *              is being called with a value of -1/10.
 * 027 11-Oct-90 fdc  Made ttol return number of chars successfully written.
 *                    Made ztime() use ctime() in all cases.
 *                    Another fix (from tmk) for bps/cps confusion.
 *                    Wrapped source lines longer than 80 characters.
 * 028 18-Oct-90 fdc  Added comments to concb() and vms_getchar() to show
 *                    how to make Ctrl-C trap work.  Didn't actually do it,
 *                    though, because Ctrl-Y apparently still can't be caught.
 *                    Also, more minor reformatting.  Adjust time() declare.
 *                    Added support for automatic parity sense in ttinl(),
 *                    within #ifdef PARSENSE conditionals.  Built with PARSENSE
 *                    defined, works ok.
 * 029  5-Apr-91 fdc  Extensive reworking of many routines to allow for
 *              network connections, addition of TGV MultiNet support.
 * 030 31-Aug-91 tmk  Fix problem with INPUT statements not timing out due to
 *              extraneous rtimer() inside gtimer().
 * 032  6-Nov-91 fdc  Correct parity problem.
 * 032  6-Nov-91 fdc  Cosmetic cleanup in sysinit().
 * 033 14-Jan-91 fdc  Fix to get_qio_maxbuf_size to prevent crashes:
 *                    remove "&" from "!test_qio(ttychn,max,&tmpbuf)",
 *                    from John Schultz at 3M.
 * 034  8-Feb-92 fdc  Don't change EIGHTBIT setting in ttvt, concb, or conbin.
 *                    Set EIGHTBIT in ttpkt only if parity is not NONE.  From
 *                    Alan Robiette, Oxford U, UK.
 * 035 10-Jun-92 fdc  Added code from Ray Hunter of The Wollongong Group to
 *                    support both WIN/TCP and TGV Multinet.  Network section
 *                    of contti() redone to eliminate polling loop.  It's
 *                    infinitely faster.
 * 036 11-Jun-92 tmk  Fixed up edit 034 so 8-bit characters could be passed
 *                    in connect mode.
 * 037 19-Jun-92 fdc  Totally rewrote all the serial input and mode-setting
 *                    routines in this module to use nonblocking, fully
 *                    buffered input and to share a common buffer.  All
 *                    serial-line input is localized to a single routine,
 *                    txbufr(), which, in turn is known only to ttinc().  The
 *                    other input routines, ttxin() and ttinl(), simply call
 *                    ttinc().  ttchk() and ttflui() are totally cognizant of
 *                    the buffer.  ttinl() now recognizes packets with
 *                    printable start characters and/or lacking terminators,
 *                    so VMS C-Kermit can now engage in "Doomsday Kermit"
 *                    protocol.  ttvt() and ttpkt() were merged into a single
 *                    new (static) routine, ttbin(), which no longer puts the
 *                    device into PASALL mode (which defeats flow control).
 *                    Added ttsndlb() to send a Long BREAK.  Much fine-tuning,
 *                    testing, and filling-in remains to be done, including
 *                    (a) make ttopen() and ttclos() aware of LAT devices; (b)
 *                    check remaining BYTLM quota before issuing a read, (c)
 *                    integrate network and serial buffers, and much more.
 *                    Anyway, this code seems to run faster than ever before,
 *                    and for the first time I can actually use sliding
 *                    windows AND long packets on my 8-year old MicroVAX-II.
 * 038 28-Jun-92 tmk  Additional work on edit 37, general cleanup of old defs.
 * 039  1-Jul-92 wb   Changes for VMS 4.4.
 * 040  4-Jul-92 tmk  Add modem signal support (ttgmdm routine).
 * 041  4-Jul-92 tmk  Add tgetent(), worker routine for el-cheapo curses.
 * 042  4-Jul-92 jh   Enable typeahead in ttbin().
 * 043 21-Aug-92 fdc  Make default flow control be KEEP instead of Xon/Xoff.
 * 044  6-Sep-92 fdc  Put default flow back to Xon/Xoff, but allow KEEP to be
 *                    used to restore device's original flow-control setting.
 * 045 23-Sep-92 fdc  Add sleep(1) to tthang().  Seems to fix HANGUP command.
 *                    Suggested by Lee Tibbert.  Change ttbin() to use global
 *                    flow variable rather than its flow parameter for setting
 *                    flow control, to ensure the desired type of flow control
 *                    is used during DIAL operations.
 * 046 26-Sep-92 fdc  Change sleep(1) in tthang() to sleep(3).  Annoying but
 *                    necessary.  IO$M_HANGUP takes about 3 seconds, but the
 *                    sys$qiow() function returns immediately instead of
 *                    waiting for the action to complete.
 * 047 08-Oct-92 HG   Add call to sys$alloc in ttopen() to prevent user with
 *              SHARE from getting port in use.  Some add'l cleanup.
 * 048 12-Oct-92 LT   Minor changes to support DEC TCP/IP (nee UCX).
 * 049 25-Oct-92 fdc  Adapt cancio() to DEC TCP/IP.
 *                    Remove superfluous ttflui() call from ttpkt().
 *                    Add code from Lee Tibbert to sysinit() to figure out OS
 *                    and architecture name at runtime.
 * 050 18-Nov-92 fdc  Read from comm device in 1024-byte chunks, rather than
 *                    trusting the qio_maxbuf_size.  This should reduce BYTLM
 *                    quota-exceeded errors.  Suggested by tmk as a temporary
 *                    workaround.
 * 051 10-May-93 fdc  Add support for SET TRANSFER CANCELLATION.
 * 052 16-May-93 fdc  Change VMSTCPIP to TCPIPLIB to agree with new CKCNET.H.
 * 053 16-May-93 fdc  ANSIfication for GNU CC, from James Sturdevant.
 * 054 08-Jun-83 fdc  Add TT$M_LOCALECHO and TT$M_ESCAPE to the terminal modes
 *                    we handle, to prevent "getty babble" with modems, VAX
 *                    PSI, etc.
 * 055 16-Jun-93 fdc  Edit 054 only affected ttbin().  This edit does the same
 *                    for conbin() and concb().  Fixes double echoing in
 *                    command mode when coming in via VAX PSI.
 * 056  8-Aug-93 fdc  Add types to all function declarations.
 * 057 17-Aug-93 fdc  Add GET_SDC macro as in CKVIOC.C, accounting for GCC.
 *                    From Tarjei T. Jensen <[e-mail]>.
 * 058 27-Sep-93 HG   Fix for real the SHARE issue when allocating terminal
 *              by dropping SHARE before trying to assign the channel.
 * 059  7-Oct-93 mlo  Added support for CMU-OpenVMS/IP ("CMU/Tek").  Requires
 *                    CMU-OpenVMS/IP sockets library, also by mlo.
 * 060  9-Oct-93 HG   Fix improper call to vms_assign_channel in edit 058,
 *                    noticed by [e-mail].
 * 061  9-Oct-93 fdc  For some reason, conbin() was turning off flow control.
 *                    This caused massive data loss during CONNECT mode when
 *                    running C-Kermit from a low-speed connection through
 *                    a DECserver.  Now conbin() leaves the console flow
 *                    control setting alone.
 * 062 10-Oct-93 ttj  Change parameters to time() and ctime() from long to
 *                    time_t (pointers).  Made prototype for vms_assign_channel
 *                    and caught an erroneous function call.
 * 063  9-Nov-93 fdc  In sysinit(), don't run sys$getdviw() on the "console"
 *                    if the console is not a terminal (from [e-mail]).
 *                    And (blame this one on me) _never_ set the backgrd flag.
 * 064 25-Nov-93 fdc  Fixed coninc(n) to return -1 on timeout.
 * 065  9-Dec-93 fdc  Fix transfer cancellation to account for parity, and
 *                    allow it only in remote mode.
 * 066 13-Dec-93 fdc  Make debug logging in ttol() show why packet writes fail.
 * 067 15-Dec-93 fdc  New, MAXBUF-proof ttol() recovers from failures by
 *                    writing the packet in chunks, whose size is computed
 *                    dynamically.  This seems to cause no noticable slowdown
 *                    in the transfer rate.
 * 068 31-Dec-93 fdc  Fix bug in parity-detection code in ttinl().
 * 069 14-Dec-93 fdc  Add ttgwsiz() routine, code from John Berryman.
 * 070 14-MAR-94 mlo  CMU_TCPIP modifications: contti - return error (-1)
 *                    if number of characters read is zero; cancio - pass
 *                    correct i/o channel for ttyfd to sys$cancel.
 * 071 15-MAR-94 mlo  ttol() - add #ifdef DEBUG for compiles with NODEBUG
 * 072 27-Mar-94 fdc  Straighten out some ttsspd()/ttgspd() confusion.
 * 073 11-AUG-94 fdc  Make conoll() return a proper return code.
 * 074 12-AUG-94 fdc  Make syscleanup() handle conres() error.  Make
 * 075 20-AUG-94 js   Make congm() get terminal type, etc, to remove annoying
 *                    "Sorry, terminal type not supported" messages when
 *                    running from a .COM file, etc.
 * 076 02-Sep-94 fdc  Call con_cancel() in syscleanup() to cancel any pending
 *                    console i/o, hopefully eliminating zombies after
 *                    after disconnection, etc.
 * 077 22-Sep-94 mlo  Don't call sys$cancel() in cancio() on CMU/Tek network
 *                    connections - it breaks the connection.
 */

/*
 Variables available to outside world:

   dftty  -- Pointer to default tty name string, like "/dev/tty".
   dfloc  -- 0 if dftty is console(remote), 1 if external line(local).
   dfprty -- Default parity
   dfflow -- Default flow control
   ckxech -- Flag for who echoes console typein:
     1 - The program (system echo is turned off)
     0 - The system (or front end, or terminal).
   functions that want to do their own echoing should check this flag
   before doing so.

   backgrd
     Flag indicating program not executing interactively.
     Used to ignore INT and QUIT signals, suppress messages, etc.
   vms_status
     Status returned by most recent VMS system service,
     can be used for error reporting.

 Functions for assigned communication line (either external or console tty):

   ttopen(ttname,local,mdmtyp) -- Open the named tty for exclusive access.
   ttclos()                -- Close & reset the tty, releasing any access lock.
   ttpkt(speed,flow)       -- Put the tty in packet mode and set the speed.
   ttvt(speed,flow)        -- Put the tty in virtual terminal mode.
                or in DIALING or CONNECTED modem control state.
   ttinl(dest,max,timo)    -- Timed read line from the tty.
   ttinc(timo)             -- Timed read character from tty.
   ttchk()                 -- See how many characters in tty input buffer.
   ttxin(n,buf)            -- Read n characters from tty (untimed).
   ttol(string,length)     -- Write a string to the tty.
   ttoc(c)                 -- Write a character to the tty.
   ttflui()                -- Flush tty input buffer.
   tt_cancel()           -- Cancel any asynch I/O to tty
*/

/*
Functions for console terminal:
   congm()   -- Get console terminal modes.
   concb(esc) -- Put the console in single-character wakeup mode with no echo.
   conbin(esc) -- Put the console in binary (raw) mode.
   conres()  -- Restore the console to mode obtained by congm().
   conoc(c)  -- Unbuffered output, one character to console.
   conol(s)  -- Unbuffered output, null-terminated string to the console.
   conola(s) -- Unbuffered output, array of lines to the console, CRLFs added.
   conxo(n,s) -- Unbuffered output, n characters to the console.
   conchk()  -- Check if characters available at console (bsd 4.2).
        Check if escape char (^\) typed at console (System III/V).
   coninc(timo)  -- Timed get a character from the console.
   conint()  -- Enable terminal interrupts on the console if not background.
   connoi()  -- Disable terminal interrupts on the console if not background.
   contti()  -- Get a character from either console or tty, whichever is first.

Time functions

   msleep(m) -- Millisecond sleep
   ztime(&s) -- Return pointer to date/time string
   rtimer()  -- Reset elapsed time counter
   gtimer()  -- Get elapsed time
*/

/* Includes */
#include "ckcdeb.h"            /* Formats for debug() */
#include "ckcasc.h"
#include "ckcker.h"

#include "ckvvms.h"

#include <stdio.h>            /* Unix Standard i/o */
#include <signal.h>            /* Interrupts */
#include <setjmp.h>            /* Longjumps */
#include <iodef.h>
#include <ttdef.h>
#include <tt2def.h>
#include <ssdef.h>
#include <descrip.h>
#include <dvidef.h>
#include <dcdef.h>
#include <devdef.h>
#include <time.h>
#include <syidef.h>
#include <prvdef.h>

/* lt 1992-10-08 Begin
 */
#ifndef __ALPHA
# ifndef __GNUC__
#  define void int
# endif /* __GNUC__ */
#endif /* __ALPHA */
/* lt 1992-10-08 End
 */

#if defined(VMS_V40) || defined(VMS_V42) || defined(VMS_V44) /* No starlet */
#define IO$_TTY_PORT 41
#else
#include <starlet.h>
#endif /* (Old VMS) */

/* Macros */

#define xx_inc(timo) (--ttxbn>=0?ttxbuf[ttxbp++]:txbufr(timo))

/* Declarations */

#ifndef __ALPHA
#ifndef MULTINET
    time_t time();
#endif
#endif
    char *ctime();            /* Convert to asctime() string */

    void dcl_exit_h();            /* Exit handler */
    unsigned short vms_assign_channel(struct dsc$descriptor_s *ttname);
    VOID tt_cancel();

/*
  This is the device name for the console.
  When we use SYS$INPUT, it prevents CONNECT from working in DCL
  procedures that do not "$ DEFINE SYS$INPUT SYS$COMMAND".
  When we use SYS$COMMAND, it allows CONNECT to work in DCL procedures,
  but it forces the command parser to read from the terminal, and therefore
  prevents inclusion of Kermit commands as "image data" in DCL procedures.
*/
#define CONDEVICE    "SYS$INPUT"
#define CONDEV_COLON "SYS$INPUT:"

/* dftty is the device name of the default device for file transfer */
/* dfloc is 1 if dftty is the user's console terminal, 0 if an external line */

    char *dftty = CTTNAM;
    int dfloc = 0;            /* Default location is local */
    int dfprty = 0;            /* Parity (0 = none) */
    int ttprty = 0;            /* Parity in use */
    int ttpflg = 0;            /* Parity not sensed yet. */
    int backgrd = 0;            /* Running in "background" (no tty) */
    static int ttpmsk = 0377;        /* Communication device parity mask */
    int ttmdm = 0;                      /* Modem in use. */
    int dfflow = FLO_XONX;        /* Default flow control is Xon/Xoff */
    int batch = 0;            /* Assume interactive */
    int ttcarr = CAR_AUT;        /* Carrier Handling Mode */
    int tvtflg = 0;            /* Flag that ttvt has been called */
    long ttspeed = -1;            /* For saving speed */
    int ttflow = -9;            /* For saving flow */

int ckxech = 0; /* 0 if system normally echoes console characters, else 1 */

unsigned int vms_status;        /* Used for system service return status */

/* Structures used within this module */

#ifndef TT$C_BAUD_38400
#define TT$C_BAUD_38400    0x11
#endif /* TT$C_BAUD_38400 */

static struct {
    unsigned char dec;
    unsigned short int line;
    } ttspeeds[] = {
    {TT$C_BAUD_50,       5},
    {TT$C_BAUD_75,       7},
    {TT$C_BAUD_110,     11},
    {TT$C_BAUD_134,     13},
        {TT$C_BAUD_150,     15},
    {TT$C_BAUD_300,     30},
    {TT$C_BAUD_600,     60},
    {TT$C_BAUD_1200,   120},
    {TT$C_BAUD_1800,   180},
    {TT$C_BAUD_2000,   200},
    {TT$C_BAUD_2400,   240},
    {TT$C_BAUD_3600,   360},
    {TT$C_BAUD_4800,   480},
    {TT$C_BAUD_7200,   720},
    {TT$C_BAUD_9600,   960},
    {TT$C_BAUD_19200, 1920},
    {TT$C_BAUD_38400, 3840},
    {0,                   0} };

/* Declarations of variables global within this module */

/* was long... */
#define TIME_T time_t
#ifdef __ALPHA
#ifdef WINTCP
#undef TIME_T
#define TIME_T long
#endif /* WINTCP */
#endif /* __ALPHA */

static TIME_T tcount = 0;        /* For timing statistics */

static char brkarray[] = {        /* For simulating BREAK */

 '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0',
 '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0',
 '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0',
 '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0'
};

int ttyfd = -1;                /* TTY file descriptor */

#ifdef COMMENT /* old */
static int conif = 0,            /* Console interrupts on/off flag */
    conclass = 0,            /* Console device type */
    cgmf = 0,                /* Flag that console modes saved */
    xlocal = 0,                         /* Flag for tty local or remote */
    ttychn = 0,                /* TTY i/o channe; */
    conchn = 0,                /* Console i/o channel */
    con_queued = 0,            /* console i/o queued in contti() */
    tt_queued = 0,            /* tty i/o queued in contti() */
    conch,                /* console input character buffer  */
    curcarr = 0,            /* Carrier mode: require/ignore */
    ttch;                /* tty input character buffer */
#else /* new */
static unsigned short
    ttychn = 0,                /* TTY i/o channe; */
    conchn = 0,                /* Console i/o channel */
    con_queued = 0,            /* console i/o queued in contti() */
    tt_queued = 0;            /* tty i/o queued in contti() */

static int conif = 0,            /* Console interrupts on/off flag */
    conclass = 0,            /* Console device type */
    cgmf = 0,                /* Flag that console modes saved */
    xlocal = 0,                         /* Flag for tty local or remote */
    conch,                /* console input character buffer  */
    curcarr = 0,            /* Carrier mode: require/ignore */
    ttch;                /* tty input character buffer */
#endif /* COMMENT */

static unsigned char escchr;        /* Escape or attn character */
static char ttnmsv[80];              /* copy of open path for tthang */
static char lclnam[80];            /* Local device name */

static char tt_fulldevnam[65];
static struct dsc$descriptor_s tt_fulldevnam_d;    /* Descriptor for line name */

static long int qio_maxbuf_size;    /* Maximum size of QIO to succeed */
static unsigned long dclexh_status;    /* Exit status for DCL exit handler */
static struct iosb_struct coniosb, ttiosb, wrk_iosb;
static struct tt_mode
    ttold, ttraw, tttvt,        /* for communication line */
    ccold, ccraw, cccbrk,        /* and for console */
    cctmp;

/* Network support */

#include "ckcnet.h"            /* Network type symbols */
extern int ttnet;            /* Network type */
static int network = 0;            /* 1 if network connection */
extern int xfrcan, xfrchr, xfrnum;    /* Transfer cancellation */

/*
  Select proper library function for getting socket device channel.
*/
#ifdef TCPIPLIB
#if defined (__DECC)
# define GET_SDC (short)decc$get_sdc
#elif (defined (VAXC) || defined (__VAXC) || defined (__GNUC__))
# define GET_SDC vaxc$get_sdc
#else
# error unknown compiler, not DECC and not VAXC
#endif /* __DECC */
#endif /* TCPIPLIB */

/* Needed for parity fixes in edit 036 */
extern int parity;            /* current parity setting */

/*
  New buffered input scheme.
*/
#define TTXBUF

#ifdef TTXBUF
#define TTXBUFL RBSIZ            /* Internal buffer size */

CHAR     ttxbuf[TTXBUFL+1];        /* The buffer */
int     ttxbp = 0, ttxbn = 0;        /* Buffer pointer and count */

/*
  T X B U F R

  Read bytes from communication device into internal buffer ttxbuf[].
  To be called only when input buffer is empty, i.e. when ttxbn == 0.

  Other comm-device reading routines, like ttinc, ttinl, ttxin, should check
  the internal buffer first, and call this routine for a refill if necessary.

  When data is read successfully, the first character is returned and
  the global buffer count, ttxbn, is set to the number of characters remaining
  in ttxbuf after it, and the global buffer offset, ttxbp, is set to 1.

  When data is not read successfully, -1 is returned indicating a timeout,
  or -2 indicating disconnection.
*/
int
txbufr(timo) int timo; {        /* TT Buffer Read */
    int count;
    int func;                /* Read function code */
    int mask;                /* Event mask */
    int vms_status;            /* Read QIO return code */
    static int trmmsk[2] = {0,0};    /* Terminal read break mask */
    static int trmlong[8] = {0,0,0,0,0,0,0,0}; /* Break on nothing */

    debug(F101,"txbufr entry, ttxbn","",ttxbn);
    if (ttxbn > 0) {            /* Should not be called */
    debug(F101,"txbufr called with ttxbn","",ttxbn); /* if ttxbn > 0! */
    ttxbn--;
    return(ttxbuf[ttxbp++] & 0xff);
    }
    ttxbp = ttxbn = 0;            /* Reset buffer pointer and count */
    ttxbuf[0] = NUL;

    if (timo < 0)            /* Be safe */
      timo = 0;
    debug(F101,"txbufr timo","",timo);

    func = IO$_READVBLK | IO$M_NOFILTR;    /* Read virtual block, no filtering */
    trmmsk[0] = sizeof(trmlong);    /* No terminators */
    trmmsk[1] = (int)&trmlong;        /* Keep all characters */

/*
  We try to scoop up as many as we can in a nonblocking read (timed, but with
  timeout value of 0).  This is supposed to return immediately with up to
  "count" characters placed in our buffer.
*/
    count = TTXBUFL;            /* Maximum characters to read */

#ifdef COMMENT
/*
  This causes problems because we are not adjusting according to the CURRENT
  BYTLM quota, but rather to the one that was obtained when Kermit started.
  Since the quota is dynamic, it might have been reduced since then.
*/
    if (count > qio_maxbuf_size)
    count = qio_maxbuf_size;
#else
/*
  So for now we use 1024, which tends to be smaller than the value obtained
  above.  Later, this should be changed to find out the remaining BYTLM quota
  and use that instead.  This size can be overridden at compile time by
  defining the symbol...
*/
#ifndef CKV_IO_SIZE
#define CKV_IO_SIZE 1024
#endif /* CKV_IO_SIZE */

    if (count > CKV_IO_SIZE)
    count = CKV_IO_SIZE;
#endif /* COMMENT */

    debug(F101,"txbufr 1 read","",count);
    vms_status = sys$qiow(QIOW_EFN, ttychn, func|IO$M_TIMED, &wrk_iosb, 0, 0,
              ttxbuf, count, 0, &trmmsk, 0, 0);
/*
 * Did something _really_ bad happen?
 */
    if (vms_status != SS$_NORMAL) {
    debug(F101,"txbufr 1 serious error, status","",vms_status);
    return(-2);
    }
    debug(F101,"txbufr 1 size","",wrk_iosb.size);
    debug(F101,"txbufr 1 iosb","",wrk_iosb.status);
    debug(F110,"txbufr 1 ttxbuf",ttxbuf,0);
/*
 * How about a hangup?
 */
    if (wrk_iosb.status == SS$_HANGUP) { /* Check for disconnection */
    debug(F100,"txbufr 1 hangup","",0);
    return(-2);
    }
/*
 * Did anything useful happen?
 */
    if (wrk_iosb.size > 0) {
    ttxbn = wrk_iosb.size;        /* Set buffer count. */
    ttxbn--;            /* Less one for the one we return */
    return(ttxbuf[ttxbp++] & 0xff);    /* Return it, bump offset */
    }
/*
 * An unexpected status?
 */
    if (wrk_iosb.status != SS$_TIMEOUT) {
    debug(F101, "txbufr 1 unexpected iosb status", "", wrk_iosb.status);
    return(-2);            /* Call it a hangup */
    }
/*
 * If we didn't get any characters, then try a blocking, possibly timed,
 * read for a single character.  Since this routine will be called again very
 * soon, the first read with a zero timeout will have the rest of the user
 * data in it.  Thus, this isn't as inefficient as it first appears.
 */
    if (timo > 0)
      func |= IO$M_TIMED;
    debug(F101,"txbufr 2 read","",count);
    vms_status = sys$qiow(QIOW_EFN, ttychn, func, &wrk_iosb, 0, 0,
              ttxbuf, 1, timo, &trmmsk, 0, 0);
    debug(F101,"txbufr 2 vms_status", "",vms_status);
    debug(F101,"txbufr 2 iosb status","",wrk_iosb.status);
/*
 * Did something _really_ bad happen?
 */
    if (vms_status != SS$_NORMAL) {
    debug(F101,"txbufr fails","",-2);
    return(-2);
    }
    debug(F101,"txbufr 2 size","",wrk_iosb.size);
    debug(F101,"txbufr 2 iosb","",wrk_iosb.status);
    debug(F110,"txbufr 2 ttxbuf",ttxbuf,0);

/*
 * How about a hangup?
 */
    if (wrk_iosb.status == SS$_HANGUP) { /* Check for disconnection */
    debug(F100,"txbufr 2 hangup","",0);
    return(-2);
    }

/*
 * Did anything useful happen?
 */
    if(wrk_iosb.size > 0) {
    ttxbn = wrk_iosb.size;        /* Set buffer count. */
    ttxbn--;            /* Less one for the one we return */
    return(ttxbuf[ttxbp++] & 0xff);    /* Return it, bump offset */
    }

/*
 * An unexpected status?
 */
    if (wrk_iosb.status != SS$_TIMEOUT) {
    debug(F101, "txbufr 2 unexpected iosb status", "", wrk_iosb.status);
    return(-2);            /* Call it a hangup */
    }

/*
 * Otherwise it's a timeout
 */
    debug(F100, "txbufr 2 returning timeout", "", 0);
    return(-1);
}

/*  T T I N C  --  Read a character from the communication device  */
/*
  ttinc() maintains an internal buffer to minimize system calls.
  Returns the next character, or -1 if there is a timeout, or -2
  on communications disconnect.  Calls txbufr() to refill its buffer
  when necessary.
*/
int
ttinc(timo) int timo; {
    int x; unsigned char c;

#ifdef NETCONN
    if (network)
      return(netinc(timo));
#endif /* NETCONN */

    debug(F101,"ttinc ttxbn","",ttxbn);
    if (--ttxbn >= 0) {            /* Something in internal buffer? */
    c = ttxbuf[ttxbp++];        /* Yes, return next character. */
    debug(F101,"ttinc returns c","",c);
    return(c & 0xff);
    } else if ((x = txbufr(timo)) < 0) { /* No, fill buffer */
    debug(F101,"ttinc timed out","",x); /* Pass along failure. */
    return(x);
    } else {                /* Success. */
    debug(F101,"ttinc returns x","",x);
    return(x & 0xff);        /* Return the character */
    }
}

/*  T T X I N  --  Get n bytes from tty input buffer  */
/*
  Call with n = number of bytes to get, buf = where to put them.

  This routine assumes that the given number of bytes is available
  and will not return until they are gotten.  You should only call this
  routine after calling ttchk to find out how many bytes are waiting to
  to be read.

  Returns:
  -1 on error, number of chars gotten on success.
*/
int
ttxin(n,buf) int n; CHAR *buf; {
    int i, x;

    debug(F101,"ttxin","",n);

#ifdef NETCONN
    if (network) {
    for (i = 0; i < n; i++) {
        if ((x = ttinc(0)) < 0) return(-1);
        buf[i] = (char) x;
    }
    } else {
#endif /* NETCONN */
/* xx_inc() is a macro */
    for (i = 0; i < n; i++) {
        if ((x = xx_inc(0)) < 0) return(-1);
        buf[i] = (char) x;
    }
#ifdef NETCONN
    }
#endif /* NETCONN */
    buf[i] = NUL;
    return(i);
}

/*  T T F L U I  --  Flush communication device input buffer  */

int
ttflui() {
    int n;
    debug(F100,"ttflui","",0);
#ifdef NETCONN
    if (network)
      return(netflui());
#endif /* NETCONN */

    ttxbn = ttxbp = 0;            /* Flush internal buffer *FIRST* */
    if ((n = ttchk()) > 0) {
    debug(F101,"ttflui count","",n);
#ifdef NETCONN
    if (network)
      while ((n--) && ttinc(2) > -1) ; /* Don't worry, it's buffered. */
    else
#endif /* NETCONN */
      while ((n--) && xx_inc(2) > -1) ; /* Don't worry, it's buffered. */
    }
    return(0);
}

/*  T T C H K  --  Check how many bytes are waiting to be read */
/*
  Returns number of bytes waiting, or -1 if connection has been dropped.
  The number of bytes waiting includes those in our internal buffer plus
  those in VMS's internal input buffer.
*/
int                    /* Check how many bytes are ready */
ttchk() {                /* for reading from network */
    static struct {
    unsigned short count;
    unsigned char first;
    unsigned char reserved1;
    long reserved2; } ttchk_struct;

#ifdef NETCONN
    if (network)            /* If network connection active... */
      return(nettchk());        /* Check real network. */
#endif /* NETCONN */

    CHECK_ERR("ttchk: sys$qiow",
    sys$qiow(QIOW_EFN, ttychn, IO$_SENSEMODE|IO$M_TYPEAHDCNT, &wrk_iosb,
         0, 0, &ttchk_struct, sizeof(ttchk_struct), 0, 0, 0, 0));
#ifdef DEBUG
    debug(F101,"ttchk count","",(int)ttchk_struct.count);
    if (ttchk_struct.count)
      debug(F101,"ttchk first","",(int)ttchk_struct.first);
#endif /* DEBUG */
    return(vms_status & 1 ? ttchk_struct.count + ttxbn : ttxbn);
}

#ifdef CTRLC
#undef CTRLC
#endif /* CTRLC */
#define CTRLC '\03'

/*  T T I N L  --  Read a record (up to break character) from comm line.  */
/*
  Reads up to "max" characters from the communication line, terminating on:

    (a) the packet length field if the "turn" argument is zero, or
    (b) on the packet-end character (eol) if the "turn" argument is nonzero
    (c) two Ctrl-C's in a row

  and returns the number of characters read upon success, or if "max" was
  exceeded or the timeout interval expired before (a) or (b), returns -1.

  The characters that were input are copied into "dest" with their parity bits
  stripped if parity was selected.  Returns the number of characters read.
  Characters after the eol are available upon the next call to this function.

  Since this function has grown to have its fingers so deeply into the
  protocol, it is slated for removal: rpack() will take care of everything.
*/

int
#ifdef CK_ANSIC
ttinl(CHAR *dest, int max, int timo, CHAR eol, CHAR start, int turn)
#else
ttinl(dest,max,timo,eol,start,turn) int max,timo,turn; CHAR *dest,eol,start;
#endif /* CK_ANSIC */
/* ttinl */ {
    int x, y, c, i, j;
    int ccn = 0;        /* Control C counter */
    int flag;
    int cc;
    unsigned char *cp;
    int pktlen = -1;
    int lplen = 0;
    int havelen = 0;

    debug(F101,"ttinl start","",start);
    debug(F101,"ttinl turn","",turn);
    i = j = flag = 0;
    ttpmsk = (ttprty) ? 0177 : 0377;    /* Set parity stripping mask. */
    while (i < max) {
    cc = network ? ttinc(timo) : xx_inc(timo); /* Read a byte */
    if (cc < 0)            /* Check for error */
      return(-1);
    /* Check for cancellation */
    if (!xlocal && xfrcan && ((cc & ttpmsk) == xfrchr)) {
        if (++ccn >= xfrnum) {    /* If xfrnum in a row, bail out. */
        fprintf(stderr,"^C...\r\n"); /* Echo Ctrl-C */
        return(-2);
        }
    } else ccn = 0;            /* No cancel, so reset counter, */

    if ((flag == 0) && ((cc & 0x7f) == start)) {
        debug(F100,"ttinl got start","",0);
        flag = 1;            /* Got packet start. */
    }
    if (flag) {            /* If we're in a packet... */
        dest[i++] = cc & ttpmsk;
        if ((cc & 0x7f) == eol) { /* Stop at eol. */
        debug(F101,"ttinl got eol, i","",i);
        break;
        }
    }
/*
  If we have not been instructed to wait for a turnaround character, we
  can go by the packet length field.  If turn != 0, we must wait for the
  end of line (eol) character before returning.
*/
#ifndef xunchar
#define xunchar(ch) (((ch) - 32 ) & 0xFF )    /* Character to number */
#endif /* xunchar */

    if (i == 2) {
        pktlen = xunchar(dest[1] & 0x7f);
        havelen = (pktlen > 1);
        debug(F101,"ttinl length","",pktlen);
    } else if (i == 5 && pktlen == 0) {
        lplen = xunchar(dest[4] & 0x7f);
    } else if (i == 6 && pktlen == 0) {
        pktlen = lplen * 95 + xunchar(dest[5] & 0x7f) + 5;
        havelen = 1;
        debug(F101,"ttinl length","",pktlen);
    }
    if (havelen && !turn && (i > pktlen+1)) { /* Use length field */
        debug(F101,"ttinl break on length","",i);
        break;
    }
    }
    dest[i] = '\0';            /* Terminate the string */
    debug(F101,"ttinl loop done, i","",i);
    debug(F101,"ttinl max","",max);
    debug(F101,"ttinl dest[i-1]","",dest[i-1]);
    debug(F101,"ttinl eol","",eol);

    if (i >= max) {
    debug(F100,"ttinl buffer overflow","",0);
    return(-1);    /* Overflowed dest buffer without getting eol */
    }
    x = i;                /* Size. */
    debug(F111,"ttinl got packet",dest,x);

    debug(F101,"ttinl size","",x);    /* Log the size */
    dest[x] = '\0';            /* Terminate with null */

    if (ttpflg++ == 0 && ttprty == 0) {    /* Check and adjust the parity. */
        if ((ttprty = parchk(dest,start,x)) > 0) {
        debug(F000,"ttinl parchk senses parity","",ttprty);
        ttpmsk = 0x7f;
        for (i = 0; i < x; i++)    /* Strip parity from this packet */
          dest[i] &= 0x7f;
    }
    if (ttprty < 0) ttprty = 0;    /* Restore if parchk error */
    }
    return(x);                /* Return length */
}

#endif /* TTXBUF */

SIGTYP (*saval)() = NULL;        /* For saving alarm handler */

VOID
ttimoff() {                /* Turn off any timer interrupts */
    alarm(0);
    if (saval) {
    signal(SIGALRM,saval);
    saval = NULL;
    } else {
    signal(SIGALRM,SIG_IGN);    /* (was SIG_DFL) */
    }
}

/*  P R I N T _ M S G  --  Log an error message from VMS  */

int
print_msg(s) char *s; {
    long int blen = 0;
    char buf[PMSG_BUF_SIZE], msg[PMSG_MSG_SIZE];
    struct dsc$descriptor_s b = {
    PMSG_BUF_SIZE-1,
    DSC$K_DTYPE_T,
    DSC$K_CLASS_S,(char *)&buf
    };

    if (!((vms_status = sys$getmsg(vms_status, &blen, &b, 0, 0)) & 1)) {
    fprintf(stderr,"print_msg; sys$getmsg\n");
    return(-1);
    }
    buf[blen] = '\0';
    sprintf(msg, "%s: %s\n", s, buf);
    debug(F100,s,"",0);
    ermsg(msg);
    return(0);
}

/*  S Y S I N I T  --  System-dependent program initialization.  */

#ifndef DVI$_FULLDEVNAM
#define DVI$_FULLDEVNAM 232
#endif /* DVI$_FULLDEVNAM */

#ifndef DVI$_STS
#define DVI$_STS 226
#endif /* DVI$_STS */

int
ttgwsiz() {                /* Get console window (screen) size */
    int x = -1;
    extern int tt_rows, tt_cols;
    typedef struct {            /* define an item list struct */
    short length;            /* length of buffer */
    short code;            /* item code */
    void *ptr;            /* ptr to buffer */
    void *retlen;            /* ptr to return length */
    } item_list;
    int status, iosb[2];
    item_list tt_dvi[] = {        /* Item list for GETDVI */
    {4,DVI$_DEVBUFSIZ,&tt_cols,0},
    {4,DVI$_TT_PAGE,&tt_rows,0},
    {0,0,0,0}
    };
    $DESCRIPTOR(sysin,CONDEVICE);
    status = sys$getdviw(0,0,&sysin,&tt_dvi,&iosb,0,0,0);
    if ((status & 1) == 0)
      return(-1);
    if (tt_rows < 1 || tt_cols < 1) return(0);
    return(1);
}

int
sysinit() {
    extern int speed;
    extern char ttname[];
    extern char *ckzsys;
    struct itmlst dviitm[] = {{64,DVI$_FULLDEVNAM,(char *)&lclnam,0},
            {sizeof(conclass),DVI$_DEVCLASS,(char *)&conclass,0},
                {0,0,0,0}};

    static struct desblk {
    long int *fl;            /* Forward link.  Used by VMS only */
    void (*fncpnt)();        /* Function to call */
    unsigned char argcnt;        /* Only one arg allowed */
    unsigned char filler[3];    /* Filler.  Must be zero */
    long int *sts;            /* Address of sts (written by VMS) */
    } dclexh_ = {0,dcl_exit_h,1,{0,0,0},&dclexh_status};

#define GETCKXSYS
/*
  Get architecture and operating system name.
*/
#ifdef GETCKXSYS

#if defined(__ALPHA)

    ckxsys = " OpenVMS AXP";

#elif !(defined(__VAX) || defined (VAX) || defined (__GNUC__))
# error Unknown Hardware type, not VAX(tm) and not AXP (TM)
#else /* VAX */

/* OK, we have a VAX so what is the name of the OS? */

#ifndef SYI$_ARCH_NAME    /* Should be in syidef.h but is not there yet */
# define SYI$_ARCH_NAME 4454
#endif /* SYI$_ARCH_NAME */

    struct iosb_t {
    short int status;        /* System service status */
    short int unused[3];
    } iosb;

    struct itmlst_t {
    short unsigned int buffer_len;    /* Buffer length */
    short unsigned int item_code;    /* Item code */
    char*buffer;            /* Where to write SYI info */
    long unsigned int *ret_len;    /* Pointer to returned length */
    long unsigned int mbz;        /* Must Be Zero */

    } itmlst;

    char arch_name[sizeof ("Alpha") - 1]; /* Architecture name */
    long unsigned int ret_len;        /* Returned length */
/*
  $getsyi of "hw_arch" will fail prior to VMS 5.5.  This failure indicates that
  the OS name is "VAX/VMS" (sic).  Use success or failure or $getsyi "hw_arch"
  rather than the more straight forward $getsyi "node_swvers" because latter
  is defined as four (4) characters and will get strange representing VMS
  10.0.
*/

/*  Default -- Not strictly correct but traditional & familiar... */
    ckxsys = " VAX/VMS";

    itmlst.buffer_len = sizeof (arch_name);
    itmlst.item_code = SYI$_ARCH_NAME;
    itmlst.buffer = arch_name;
    itmlst.ret_len = &ret_len;
    itmlst.mbz = 0;

    if ((sys$getsyiw (0, 0, 0,
            &itmlst,
            &iosb,
            0, 0) & 1) == 1)
    if ((iosb.status & 1) == 1)
        ckxsys = " OpenVMS VAX";

    ckzsys = ckxsys;            /* Same deal for file module */

#endif /* OS Type */
#endif /* GETCKXSYS */

/*
 * Set up DCL Exit handler.  This allows us to reset terminal
 * and any other modifications we have done.
 */
    debug(F101,"sysinit ttychn","",ttychn);
    debug(F101,"sysinit conchn","",conchn);
    if (!CHECK_ERR("sysinit: sys$dclexh",
           sys$dclexh(&dclexh_))) {
        debug(F100,"sysinit failed to declare exit handler","",0);
#ifdef COMMENT
    return(0);
#endif /* COMMENT */
    }
    if (ttychn)                         /* if comms line already opened */
      return(0);            /* (how could it be???) */

    if (!conchn) {            /* Get console channel */
#ifdef CMU_TCPIP
      /* need to open console using libcmu routine to enable `select' call on
       * file descriptor zero.
       */
      cmu_stdin_open(dftty);
      conchn = cmu_get_sdc(0);
#else
      struct dsc$descriptor_s devnam =
        {sizeof(dftty)-1,DSC$K_DTYPE_T,DSC$K_CLASS_S,dftty};
      conchn = vms_assign_channel(&devnam);
#endif /* CMU_TCPIP */
    }
    congm();                /* Get and save its modes */
/*
 * Parse console terminal device name.
 */
    if (isatty(0)) {             /* So following won't fail under batch */
    CHECK_ERR("sysinit: sys$getdviw",
          sys$getdviw(0, conchn, 0, &dviitm, &wrk_iosb, 0, 0, 0));
    debug(F111,"sysinit","lclnam",lclnam);

    if (!CHECK_ERR("sysinit: sys$qiow",
               sys$qiow(QIOW_EFN, conchn, IO$_SENSEMODE,
                &wrk_iosb, 0, 0,
                &ccold, sizeof(ccold), 0, 0, 0, 0)))
      return(-1);
    ttspeed = speed = ttispd((unsigned char) wrk_iosb.size);
    debug(F111,"sysinit speed",lclnam,speed);
    strncpy(ttname,lclnam,80);
    }

    /* Initialize descriptor */
    tt_fulldevnam_d.dsc$b_dtype = DSC$K_DTYPE_T;
    tt_fulldevnam_d.dsc$b_class = DSC$K_CLASS_S;

    debug(F100,"sysinit done","",0);
    return(0);
}

/*
 * DCL Exit handler.  This is the cleanup handler for program.
 * Any final cleanup (closing channels etc) should be done at this
 * point.
 */
VOID
dcl_exit_h(sts) unsigned long int *sts; {
    syscleanup();
    return;
}

/*  S Y S C L E A N U P -- System-dependent program epilog.  */


int
syscleanup() {
    int x;
    extern zclosf();
    void con_cancel();
    debug(F101,"syscleanup entry","",ttyfd);
    con_cancel();        /* Cancel pending console i/o. */
    ttclos(ttyfd);        /* Do the cleanup no matter what... */
    zclosf(ZSYSFN);        /* Close various files and kill child procs */
#ifdef COMMENT
    /* This is a bit extreme... */
    if ((x = conres()) < 0) exit(SS$_ABORT);
#else
    conres();
#endif /* COMMENT */
    debug(F101,"syscleanup conres","",x);
    printf("\r");
    return(0);
}

/*  T T O P E N  --  Open a tty for exclusive access.  */

/*  Returns 0 on success, -1 on failure.  */
/*
  If called with lcl < 0, sets value of lcl as follows:
  0: the terminal named by ttname is the job's controlling terminal.
  1: the terminal named by ttname is not the job's controlling terminal.
  But watch out: if a line is already open, or if requested line can't
  be opened, then lcl remains (and is returned as) -1.
*/
int
ttopen(ttname,lcl,modem,timo) char *ttname; int *lcl, modem, timo; {
    extern int speed;
    int s, x;
    unsigned long int no_share_priv[2], prev_privs[2];
    unsigned long int devchar, devclass, devsts;
/*    char dvibuf[65]; */
    struct dsc$descriptor_s devnam = {0,DSC$K_DTYPE_T,DSC$K_CLASS_S,0};
    struct itmlst dviitm[] = {{64,DVI$_FULLDEVNAM,(char *)&tt_fulldevnam,0},
            {sizeof(devchar),DVI$_DEVCHAR,(char *)&devchar,0},
            {sizeof(devclass),DVI$_DEVCLASS,(char *)&devclass,0},
            {sizeof(devsts),DVI$_STS,(char *)&devsts,0},
            {0,0,0,0}};

#ifdef NETCONN
    if (network && ttyfd > -1) {    /* if device already opened */
        if (strncmp(ttname,ttnmsv,80))    /* are new & old names equal? */
          ttclos(ttyfd);        /* no, close old ttname, open new */
        else                 /* else same, ignore this call, */
      return(0);            /* and return. */
    }
    if (modem < 0) {            /* modem < 0 = special code for net */
    int x;
    ttmdm = modem;
    modem = -modem;            /* Positive network type number */
    debug(F111,"ttopen net",ttname,modem);
    x = netopen(ttname, lcl, modem); /* (see ckcnet.h) */
    if (x > -1) {
        strncpy(ttnmsv,ttname,DEVNAMLEN);
        network = 1;
#ifdef COMMENT
/* Let netopen() handle this. */
        x = tn_ini();        /* Initialize telnet protocol. */
#endif /* COMMENT */
        ttnet = modem;
    } else network = 0;
        return(x);
    }
#endif /* NETCONN */

    if (ttychn) return(0);        /* Close channel if open */

    devnam.dsc$w_length  = strlen(ttname);
    devnam.dsc$a_pointer = ttname;
    sys$getdviw(0, 0, &devnam, &dviitm, &wrk_iosb, 0, 0, 0);
    tt_fulldevnam[65] = '\0';        /* Make sure it has an end.... */

    if (devclass != DC$_TERM) {        /* Is it a terminal? */
    fprintf(stderr,
        "%%CKERMIT-W-NOTTERM, %s is not a terminal\n",ttname);
    return(-1);
    }
    if (!(devchar & DEV$M_AVL)) {    /* Is it available? */
    fprintf(stderr,
        "%%CKERMIT-W-NOTAVAL, %s is not available\n",tt_fulldevnam);
    return(-5);
    }
    if (!(devsts & UCB$M_ONLINE)) {    /* Is it online? */
    fprintf(stderr,
        "%%CKERMIT-W-OFFLINE, %s is not online\n",tt_fulldevnam);
    return(-5);
    }
    ttmdm = modem;            /* Make this available to other fns */
    xlocal = *lcl;            /* Make this available to other fns */

/*
 *  Set up the tt_fulldevnam_d descriptor for use by ttclos() later.
 */
    tt_fulldevnam_d.dsc$w_length  = strlen(tt_fulldevnam);
    tt_fulldevnam_d.dsc$a_pointer = tt_fulldevnam;

/*
 *  Assume the user has SHARE privilege enabled and turn it off.  This is
 *  necessary to prevent a privileged user from assigning a channel to
 *  a device already in use by another process.
 */
    no_share_priv[0] = PRV$M_SHARE;
    sys$setprv (0, &no_share_priv, 0, &prev_privs);

    ttychn = vms_assign_channel(&devnam); /* Get a channel for it. */

    sys$setprv (1, &prev_privs, 0, 0);    /* Re-enable the old privs */

    debug(F111,"ttopen","modem",modem);
    debug(F101," ttychn","",ttychn);

    if (!ttychn) return(-1);        /* If couldn't open, fail. */
/*
 * Check for maximum size of QIO, so as to not get the dreaded quota exceeded
 * status returned.  When doing a QIO that has a larger buffer than
 * MAXBUF, exceeded quota wil be returned.
 *
 * Example: MAXBUF = 2048, QIO = 1936, overhead is 112 will succeed.
 *        QIO of 1937 will fail.
 *
 * This can change for different versions of VMS.
 */
    qio_maxbuf_size = get_qio_maxbuf_size(ttychn);

    strncpy(ttname,tt_fulldevnam,80);    /* Copy true name back to main pgm  */

    strcpy(ttnmsv,ttname);        /* Open, keep copy of name locally. */
    ttxbn = ttxbp = 0;            /* Initialize input buffer */

/* Caller wants us to figure out if line is controlling tty */

    debug(F111,"ttopen ok",ttname,*lcl);
    if (*lcl < 0) {
    if (conclass == DC$_TERM)
      xlocal = (strncmp(ttname,lclnam,80) == 0) ? 0 : 1;
    else
      xlocal = 1;             /* If not a term, then we must be local */
    debug(F111,"ttyname",lclnam,xlocal);
    }
    if (!CHECK_ERR("ttopen: sys$qiow",
    sys$qiow(QIOW_EFN, ttychn, IO$_SENSEMODE, &wrk_iosb, 0, 0,
         &ttold, sizeof(ttold), 0, 0, 0, 0))) return(-1);

    ttspeed = speed = ttispd((unsigned char) wrk_iosb.size);

/* Got the line, now set the desired value for local. */

    if (*lcl) *lcl = xlocal;

    tttvt = ttold;
    ttraw = ttold;
    debug(F101," lcl","",*lcl);
    return(0);
}

#ifdef COMMENT
/*
  Old version.
*/
unsigned long int
vms_assign_channel(ttname) char *ttname;  {
    unsigned int channel = 0;
    struct dsc$descriptor_s d = {0,DSC$K_DTYPE_T,DSC$K_CLASS_S,0};

    d.dsc$w_length  = strlen(ttname);
    d.dsc$a_pointer = ttname;
    if (!CHECK_ERR("vms_assign_channel: sys$assign",
    sys$assign(&d, &channel, 0, 0))) return(0);
    return(channel);
}
#else
/*
  New version from Hunter Goatley.
*/
unsigned short int
vms_assign_channel(ttname) struct dsc$descriptor_s *ttname; {
    unsigned short channel = 0;

#ifdef COMMENT
/* what's all this then ... */
    struct dsc$descriptor_s d = {0,DSC$K_DTYPE_T,DSC$K_CLASS_S,0};
    d.dsc$w_length  = strlen(ttname);
    d.dsc$a_pointer = ttname;
#endif /* COMMENT */

    if (!CHECK_ERR("vms_assign_channel: sys$assign",
    sys$assign(ttname, &channel, 0, 0))) return(0);

#ifdef NEW_STUFF_FROM_BRUCE_DAY
/*
  Which is not presently defined...
  This is supposed to allow C-Kermit to go into protocol mode on an LTA
  device without a prior CONNECT command.
*/
#ifdef IO$M_LT_CONNECT
    vms_status = sys$qiow(QIOW_EFN, channel, IO$_TTY_PORT|IO$M_LT_CONNECT,
                          &wrk_iosb, 0, 0, 0, 0, 0, 0, 0, 0);
    debug(F101, "vms_assign_channel LAT connect status","",vms_status);
    debug(F101, "vms_assign_channel LAT connect iosb","",wrk_iosb.status);
#endif /* IO$M_LT_CONNECT */
#endif /* NEW_STUFF_FROM_BRUCE_DAY */

    return(channel);
}
#endif /* COMMENT */

/*  T T C L O S  --  Close the communication device.  */

int
ttclos(ttyfd) int ttyfd; {
#ifdef NETCONN
    if (network) {            /* Network connection. */
    debug(F100,"ttclos closing net","",0);
    netclos();            /* Close it. */
    network = 0;
    return(0);
    }
#endif /* NETCONN */
    if (!ttychn) return(0);        /* Wasn't open. */
/*
  Observations indicate that it can take 20-30 seconds for DTR to drop
  after closing the device.  Perhaps a call to tthang() should go here.
*/
    ttres();                /* Reset modes. */

/*
  Assume it's a LAT device and try to do a LAT disconnect on it.
  If it fails, then it's not a LAT device and no harm is done.
*/
#ifdef IO$M_LT_DISCON
    vms_status = sys$qiow(QIOW_EFN, ttychn, IO$_TTY_PORT|IO$M_LT_DISCON,
              &wrk_iosb, 0, 0, 0, 0, 0, 0, 0, 0);
    debug(F101, "ttclos LAT disconnect, status", "", vms_status);
    debug(F101, "ttclos LAT disconnect, iosb", "", wrk_iosb.status);
#else
    debug(F100, "ttclos LAT disconnect not supported", "", 0);
#endif /* IO$M_LT_DISCON */
    if (!CHECK_ERR("ttclos: sys$dassgn",
    sys$dassgn(ttychn))) return(-1);
    ttychn = 0;                /* Mark it as closed. */
    return(0);
}


/*  T T R E S  --  Restore terminal to its original modes.  */

int
ttres() {                /* Restore the tty to normal. */
#ifdef NETCONN
    if (network) return (0);        /* Network connection, do nothing */
#endif /* NETCONN */

    if (!ttychn) return(-1);        /* Not open. */

    tt_cancel();            /* Cancel outstanding I/O */
    msleep(250);            /* Wait for pending i/o to finish. */
    debug(F101,"ttres, ttychn","",ttychn);
    if (!CHECK_ERR("ttres: sys$qiow",
    sys$qiow(QIOW_EFN, ttychn, IO$_SETMODE, &wrk_iosb, 0, 0,
             &ttold, sizeof(ttold), 0, 0, 0, 0))) return(-1);
    return(0);
}

/*  T T B I N  --  Code shared by ttpkt() and ttvt()  */
/*
  Puts communication device in "binary" mode.  In VMS there's no distinction
  between device modes for terminal connection, packet operation, and dialing.
*/
static int
ttbin(speed, xflow, xparity) int speed, xflow, xparity; {
    int s;
    extern int flow;            /* Global flow control variable */

#ifdef NETCONN
    if (network) return(0);        /* Nothing to do on net connections */
#endif /* NETCONN */
    if (!ttychn) return(-1);        /* Not open. */

    ttspeed = speed;            /* Keep local copies of arguments */
    if (xflow != FLO_DIAL && ttflow != FLO_DIAX)
      ttflow = xflow;            /* for other CKVTIO routines. */
    if (xparity > -1) {
    ttprty  = xparity;
    ttpflg  = 0;            /* Parity not sensed yet */
    ttpmsk  = ttprty ? 0177 : 0377;    /* Parity stripping mask */
    debug(F101,"ttbin ttprty","",ttprty);
    }
    ttraw = ttold;            /* Get a fresh copy of this */

    if ((s = ttsspd(speed/10)) < 0)    /* Get internal speed code */
      s = 0;

/*
 * Log original terminal settings for debugging purposes
 */
    debug(F101, "original ttraw.basic", "", ttraw.basic);
    debug(F101, "original ttraw.extended", "", ttraw.extended);

/*
 * Settings based on call parameters flow-control and parity...
 * NOTE: we are using the GLOBAL copy of flow, not our parameter here.
 * This is because the parameter might be FLO_DIAL or FLO_DIALX, which
 * is not flow control at all.
 */
    if (flow == FLO_XONX) {                /* FLOW = XON/XOFF */
    ttraw.basic |=  (TT$M_HOSTSYNC|TT$M_TTSYNC);
    } else if (flow == FLO_NONE) {            /* FLOW = NONE */
    ttraw.basic &= ~(TT$M_HOSTSYNC|TT$M_TTSYNC);
    } else if (flow == FLO_KEEP) {            /* FLOW = KEEP */
/*
 * Put flow-control paramaters back the way we found them when
 * the device was first opened.
 */
    if (ttold.basic & TT$M_HOSTSYNC)
      ttraw.basic |= TT$M_HOSTSYNC;
    else
      ttraw.basic &= ~TT$M_HOSTSYNC;
    if (ttold.basic & TT$M_TTSYNC)
      ttraw.basic |= TT$M_TTSYNC;
    else
      ttraw.basic &= ~TT$M_TTSYNC;
/*
  NOTE: any other FLOW-related parameters should also be handled here.
  READSYNC?  And especially if DEC ever implements RTS/CTS or other
  hardware flow control for (Open)VMS.
*/
    }

/*
  EIGHTBIT setting depends on GLOBAL copy of parity variable, not our
  parameter.
*/
    if (parity == 0)
      ttraw.basic  |= TT$M_EIGHTBIT;    /* Allow 8-bit data if no parity */
    else                /* Otherwise */
      ttraw.basic  &= ~TT$M_EIGHTBIT;    /* 7-bit data. */

    ttraw.basic |= TT$M_NOECHO;        /* Turn off echo */
    ttraw.basic |= TT$M_NOBRDCST;    /* Turn off broadcasts */
    ttraw.basic &= ~TT$M_NOTYPEAHD;    /* Enable type-ahead */
    ttraw.basic &= ~TT$M_ESCAPE;    /* Disable escape-seq processing */
    ttraw.extended &= ~TT2$M_LOCALECHO;    /* Disable local echo */
    ttraw.extended |= TT2$M_PASTHRU;    /* Enable pass-through mode */
    ttraw.extended |= TT2$M_ALTYPEAHD;    /* Use big type-ahead buffers */

/*
 * Report what we did so we can check for problems
 */
    debug(F101, "ttraw.basic", "", ttraw.basic);
    debug(F101, "ttraw.extended", "", ttraw.extended);

    vms_status = sys$qiow(QIOW_EFN, ttychn, IO$_SETMODE, &wrk_iosb, 0, 0,
             &ttraw, sizeof(ttraw), s, 0, 0, 0);

    if (vms_status != SS$_NORMAL) {    /* Error queuing request */
    print_msg("ttbin: sys$qiow");
    return(-1);
    }
    if (wrk_iosb.status != SS$_NORMAL) { /* Error executing request */
    vms_status = wrk_iosb.status;
    print_msg("ttbin: sys$qiow(iosb)");
    return(-1);
    }
    debug(F100,"ttbin ok","",0);
    return(0);                /* All OK */
}

/*  T T P K T  --  Condition the communication device for packets. */

#ifdef COMMENT
#define DIALING    4        /* Flags (via flow) for modem handling */
#define CONNECT 5        /* NOT YET IMPLEMENTED IN VMS! */
#endif /* COMMENT */

/*  Returns 0 on success, -1 on failure.  */

int
ttpkt(speed,flow,parity) long speed; int flow, parity; {
    int x;
    debug(F101,"ttpkt flow","",flow);
    x = ttbin(speed,flow,parity);    /* Put device in binary mode */
    debug(F101,"ttpkt ttbin","",x);
    return(x);
}

/*  T T V T  --  Condition communication device terminal connection. */

int
ttvt(speed,flow) long speed; int flow; {
    int x;
    debug(F101,"ttvt flow","",flow);
    if ((x = ttbin(speed,flow,-1)) > -1) /* Put device in binary mode */
      tvtflg = 1;
    debug(F101,"ttvt ttbin","",x);
    return(x);
}

/* T T I S P D  -- Return binary baud rate for internal coded speed */

int
ttispd(ispeed) unsigned char ispeed; {
    int s;

#ifdef NETCONN
    if (network) return(-1);
#endif /* NETCONN */

/* When the line is set, grab the line speed  and save it */

    for (s = 0;  ttspeeds[s].dec &&
    (ttspeeds[s].dec != ispeed);  s++)
        ;

/* If speed is zero, then no match.  Set speed to -1 so it is undefined */

    return(ttspeeds[s].line ? (int) ttspeeds[s].line * 10 : -1);
}


/*  T T S S P D  --  Return the internal baud rate code for 'speed'.  */

int
ttsspd(cps) int cps; {
    int s;
    char msg[50];

#ifdef    NETCONN
    if (network) return(0);
#endif    /* NETCONN */

    if (cps <= 0)            /* 026 Unknown cps fails */
      return (-1);
    for (s = 0;  ttspeeds[s].line && (ttspeeds[s].line != cps);  s++) ;
    if (ttspeeds[s].line) {
        ttspeed = cps * 10L;        /* Make a copy global to this module */
    if (ttspeed == 70L)        /* ... in bits per second, not cps, */
      ttspeed = 75L;        /* because ttgspd() uses it! */
    return(ttspeeds[s].dec);
    } else {
    sprintf(msg,"Unsupported line speed - %d\n",cps*10);
    ermsg(msg);
    ermsg("Current speed not changed\n");
    return(-1);
    }
}


/* Interrupt Functions */


/*  C O N I N T  --  Console Interrupt setter  */

static int (*cctrap)();

VOID
#ifdef CK_ANSIC
conint(SIGTYP (*f)(int), SIGTYP (*s)(int))
#else
conint(f,s) int (*f)(int), (*s)(int);
#endif /* CK_ANSIC */
/* conint */ {                /* Set an interrupt trap. */

    cctrap = f;                /* Make a global copy */
    debug(F101,"conint batch","",batch);
    if (batch) return;            /* Ignore signals in background. */

#ifdef COMMENT
/*
   Forget this whole thing.
   The batch flag should be set in only one place: congm().
*/

/*
  Check if invoked in background -- if so signals set to be ignored.
  But VMS has no notion of background, so no worries, right?
*/
    if (!isatty(0)) {
    debug(F100,"conint isatty diagnoses batch","",0);
#ifdef COMMENT
    batch = backgrd = 1;
#else
/*
  But we still might need to know whether we are running under batch.
  In which case, the test above is probably inadequate.  According to Carl
  Friedberg <[e-mail]>, "I believe this can be done unambiguously by
  checking that (1) SYS$GETJPI returns a null string as the terminal; and
  (2) the current process is NOT a subprocess (a subprocess ALWAYS has a null
  string as its terminal ID). The real test is if PCB$L_STS has the
  PCB$M_BATCH bit set.  If the current process is a subprocess, then the test
  must be repeated for the MASTER (root) process in the job tree.  It is legal
  to run Kermit in a subprocess from within a batch job... and in that case,
  it should still behave like a batch job (no terminal input; must execute a
  SET LINE command).
*/
    batch = 1;
    backgrd = 0;
#endif /* COMMENT */
    return;
    }
#endif /* COMMENT */
    signal(SIGINT,f);            /* Function to trap to. */
    conif = 1;                /* Flag console interrupts on. */
}

/*  C O N N O I  --  Reset console terminal interrupts */

VOID
connoi() {                /* Console-no-interrupts */

    if (batch) return;            /* must ignore signals in bkgrd */

#ifdef COMMENT
/* wrong... */
    signal(SIGINT,SIG_DFL);
#else
/* right?.. */
    signal(SIGINT,SIG_IGN);
#endif /* COMMENT */
    conif = 0;
}

/*  T T O L  --  Write string s, length n, to communication device.  */

#ifndef IO$M_BREAKTHRU
#define IO$M_BREAKTHRU    0x0200
#endif /* IO$M_BREAKTHRU */

#ifndef SS$_EXQUOTA
#define SS$_EXQUOTA 28
#endif /* SS$_EXQUOTA */

int
ttol(s,n) int n; CHAR *s; {
    int
      remaining,            /* Amount left to write */
      size;                /* How much to write this time */
    static int max = 0;            /* Chunk size for writing */

#ifdef NETCONN
    debug(F101,"ttol network","",network);
    if (network)            /* If SET HOST connection, */
    return(nettol(s,n));        /* call network package. */
#endif /* NETCONN */

/* It's not a SET HOST connection. */

    debug(F101,"ttol ttychn","",ttychn);
    if (!ttychn) return(-1);        /* Not open. */
    debug(F101,"ttol length","",n);
    debug(F101,"ttol max","",max);

/* Have we already calculated a chunk size? */

    if (max == 0) {            /* No, try to send whole packet. */
    vms_status = sys$qiow(QIOW_EFN, ttychn, IO$_WRITEVBLK|IO$M_BREAKTHRU,
                  &wrk_iosb, 0, 0, s, n, 0, 0, 0, 0);
    if (vms_status == SS$_NORMAL) {
        debug(F101,"ttol 1 ok","",n);
        return(n);
    }
#ifdef DEBUG
    if (deblog) {            /* Failed. */
        debug(F101,"ttol 1 error, vms_status","",vms_status);
        debug(F101,"ttol 1 iosb size","",wrk_iosb.size);
        debug(F101,"ttol 1 iosb status","",wrk_iosb.status);
    }
#endif
    if (vms_status != SS$_EXQUOTA)    /* "Quota exceeded"? */
      return(-3);            /* No, something else, give up. */
/*
  Here we should find out what MAXBUF is (not to mention BYTLM, BIOLM, and
  friends), and chop up the packet into pieces accordingly.  But reportedly
  this information, and how to use it (percent overhead, etc), is highly
  VMS-version-dependent.  So instead we just try different numbers.  Our first
  attempt keeps dividing it in half until it works, down to about 70.
*/
    do {
        max = (max == 0) ? n / 2 : max / 2;
        debug(F101,"ttol 2 max","",max);
        vms_status = sys$qiow(QIOW_EFN, ttychn,
                  IO$_WRITEVBLK|IO$M_BREAKTHRU,
                  &wrk_iosb, 0, 0, s, max, 0, 0, 0, 0);
          debug(F101,"ttol 2 vms_status","",vms_status);
        if (vms_status == SS$_NORMAL)
          break;
    } while (max > 70);        /* 70 is the minimum. */

    if (vms_status != SS$_NORMAL)    /* Loop exhausted, fail. */
      return(-3);

    } else {                /* We already calculated max. */

    size = (max > n) ? n : max;      /* Write 1st chunk, but not too much */
    vms_status = sys$qiow(QIOW_EFN, ttychn, IO$_WRITEVBLK|IO$M_BREAKTHRU,
                  &wrk_iosb, 0, 0, s, size, 0, 0, 0, 0);
    debug(F101,"ttol 3 vms_status","",vms_status);
    if (vms_status != SS$_NORMAL)
      return(-3);
    if (size == n) {        /* (Not strictly necessary) */
        debug(F101,"ttol 3 done","",n);
          return(n);
    }
    }
/*
  We have written the first chunk successfully, now write the remaining
  max-sized chunks, plus the (usually) less-than-max-sized last chunk.
*/
    remaining = n;
    while (1) {
    s += max;            /* Where to start */
    remaining -= max;        /* How much left to write */
    size = (remaining < max) ?    /* How much to write this time */
      remaining : max;
    if (size < 1)            /* Done? */
      break;

      debug(F101,"ttol 4 size","",size);
      vms_status = sys$qiow(QIOW_EFN, ttychn, IO$_WRITEVBLK|IO$M_BREAKTHRU,
                  &wrk_iosb, 0, 0, s, size, 0, 0, 0, 0);
    debug(F101,"ttol 4 vms_status","",vms_status);
    if (vms_status != SS$_NORMAL)
      return(-3);
    }
    debug(F101,"ttol 5 done","",n);
    return(n);
}

/*  T T O C  --  Output a character to the communication line  */

int
#ifdef CK_ANSIC
ttoc(char c)
#else
ttoc(c) char c;
#endif    /* CK_ANSIC */
/* ttoc */ {
#ifdef NETCONN
    if (network) {
    return(nettoc(c));
    } else {
#endif /* NETCONN */
    debug(F101,"ttoc char","",c);
    if (!ttychn) {
        debug(F100,"ttoc ttychn not open","",0);
        return(-1);            /* Not open. */
    }
    if (CHECK_ERR("ttoc: sys$qiow",
              sys$qiow(QIOW_EFN, ttychn, IO$_WRITEVBLK|IO$M_BREAKTHRU,
                   &wrk_iosb, 0, 0, &c, 1, 0, 0, 0, 0)))
      return(0);
#ifdef NETCONN
    }
#endif /* NETCONN */
    return(-1);
}

/*  T T _ C A N C E L  --  Cancel i/o on tty channel if not complete  */

VOID
tt_cancel() {
    int mask;
#ifdef NETCONN
    if (network) return;
#endif /* NETCONN */
    CHECK_ERR("tt_cancel: sys$cancel",sys$cancel(ttychn));
    tt_queued = 0;
}

/*  C O N _ C A N C E L  --  Cancel i/o on console channel if not complete  */

VOID
con_cancel() {
    int mask;

    CHECK_ERR("con_cancel: sys$cancel",sys$cancel(conchn));
    con_queued = 0;
}

/*  S N D B R K  --  Send a BREAK signal of the given length.  */

int
sndbrk(msec) int msec; {
    int long x = 0;
    int brklen;
    struct iosb_struct  tmp_ttiosb;
    struct tt_mode ttchr;
#ifndef TT$M_BREAK            /* For old VMS with no BREAK... */
/*
  Note: 110 is used instead of 50, because 50 is not supported by all
  VAX serial port controllers.
*/
#define BRKSPD = 110            /* Speed for simulating BREAK */
#define BRKSYM = TT$C_BAUD_110;        /* VMS symbol for this speed */
#endif /* TT$M_BREAK */

#ifdef NETCONN
    if (network)             /* Send network BREAK */
      return(netbreak());        /* Length doesn't matter */
#endif /* NETCONN */

    if (!ttychn) return(-1);        /* SET LINE not done. */
    debug(F101,"sndbrk msec","",msec);

    tt_cancel();            /* Cancel I/O */

#ifndef TT$M_BREAK            /* VMS doesn't have BREAK function */

/* Send the right number of NULs at BREAK-simulation speed... */

    brklen = ( BRKSPD * 1000 ) / ( msec * 10 ); /* Calculate number of chars */
    if (brklen > sizeof(brkarray)) brklen = sizeof(brkarray);
    debug(F101,"sndbrk speed","",BRKSPD);
    debug(F101,"sndbrk brklen","",brklen);
    if (!CHECK_ERR("ttsndb: SENSEMODE",
    sys$qiow(QIOW_EFN, ttychn, IO$_SENSEMODE, &wrk_iosb, 0, 0,
        &ttchr, sizeof(ttchr), 0, 0, 0, 0))) return(-1);
    if (!CHECK_ERR("ttsndb: SETMODE(1)",
    sys$qiow(QIOW_EFN, ttychn, IO$_SETMODE, &tmp_ttiosb, 0, 0,
        &ttchr, sizeof(ttchr), BRKSYM, 0, 0, 0))) return(-1);
    if (!CHECK_ERR("ttsndb: writing nulls",
    sys$qiow(QIOW_EFN, ttychn, IO$_WRITEVBLK|IO$M_BREAKTHRU, &tmp_ttiosb,
         0, 0, (char *) brkarray, brklen, 0, 0, 0, 0))) return(-1);
    if (!CHECK_ERR("ttsndb: SETMODE(2)",
    sys$qiow(QIOW_EFN, ttychn, IO$_SETMODE, &tmp_ttiosb, 0, 0,
        &ttchr, sizeof(ttchr), wrk_iosb.size, 0, 0, 0))) return(-1);
#else
    if (!CHECK_ERR("ttsndb: SENSEMODE",
    sys$qiow(QIOW_EFN, ttychn, IO$_SENSEMODE, &wrk_iosb, 0, 0,
        &ttchr, sizeof(ttchr), 0, 0, 0, 0))) return(-1);
    x = TT$M_BREAK;            /* Break signal on */
    if (!CHECK_ERR("ttsndb: SETMODE(1)",
    sys$qiow(QIOW_EFN, ttychn, IO$_SETMODE, &wrk_iosb, 0, 0,
        &ttchr, sizeof(ttchr), 0, 0, x, 0))) return(-1);
    msleep(msec);            /* Sleep requested amount of time */
    x = 0;                /* Break signal off */
    if (!CHECK_ERR("ttsndb: SETMODE(2)",
    sys$qiow(QIOW_EFN, ttychn, IO$_SETMODE, &wrk_iosb, 0, 0,
        &ttchr, sizeof(ttchr), 0, 0, x, 0))) return(-1);
#endif /* TT$M_BREAK */
    return(0);
}

/*  T T S N D B  --  Send a BREAK signal  */

int
ttsndb() {
    return(sndbrk(275));
}

/*  T T S N D L B  --  Send a Long BREAK signal  */

int
ttsndlb() {
    return(sndbrk(1500));
}

/*  T T H A N G  --  Hang up the communications line  */
/*
  Warning: As written, this function DOES NOT WORK on terminal server
  ports.  This is a shortcoming of VMS, confirmed by the Digital Diagnostic
  Center (or whatever DDC stands for).  Someone should add code here to test
  if the ttychn device is not a real terminal, and if so to handle it some
  other way, like set the speed to zero for a sec, or close and reopen the
  device.
*/
int
tthang() {
    if (!xlocal) return(0);        /* Only on local connections. */

#ifdef NETCONN
    if (network) {            /* Network connection. */
    int x;
    if (netclos() < 0) return(-1);    /* Close it */
        tvtflg = 0;
        x = 1;
    netopen(ttnmsv, &x, ttmdm);    /* Open it again */
        return(1);
    }
#endif /* NETCONN */

    if (!ttychn) return(0);        /* Not open. */

    tt_cancel();            /* Cancel pending i/o. */
/*
  This is NOT listed in the VMS Terminal Driver as one of the functions
  that does NOT work with LAT devices.
*/
    debug(F101,"tthang 1","",gtimer());
    if (!CHECK_ERR("tthang: sys$qiow",
    sys$qiow(QIOW_EFN, ttychn, IO$_SETMODE|IO$M_HANGUP, &wrk_iosb, 0, 0,
        0, 0, 0, 0, 0, 0))) return(-1);
/*
  The following 3-second sleep is required because the sys$qiow() returns
  immediately, about 2.5 seconds before VMS brings DTR back up.  Without this
  sleep(), DIAL does not work at all if DIAL HANGUP is ON, and, worse,
  subsequent operations on the device can hang the Kermit process
  uninterruptibly.
*/
    sleep(3);
    debug(F101,"tthang 2","",gtimer());
    return(1);
}

/*  M S L E E P  --  Millisecond version of sleep().  */

/*
 Handles intervals up to about 7 minutes (2**32 / 10**7 seconds)
*/
int
msleep(m) int m; {

    struct time_struct {
    long int hi, lo;
    } t;

    if (m <= 0) return(0);
    t.hi = -10000 * m;  /*  Time in 100-nanosecond units  */
    t.lo = -1;
    if (!CHECK_ERR("msleep: sys$schdwk",
    sys$schdwk(0, 0, &t, 0))) return(-1);
    sys$hiber();
    debug(F101,"msleep ok","",m);
    return(0);
}

/*  R T I M E R --  Reset elapsed time counter  */

VOID
rtimer() {
    tcount = time( (TIME_T *) 0);
}


/*  G T I M E R --  Get current value of elapsed time counter in seconds  */

int
gtimer() {
    int x;
    x = (int) (time( (TIME_T *) 0 ) - tcount);
    return( (x < 0) ? 0 : x );
}

/*  Z T I M E  --  Return date/time string  */

VOID
ztime(s) char **s; {
    static TIME_T clock;
#ifdef COMMENT
#ifdef bogus
    static char time_string[24];
    struct dsc$descriptor_s t =
    {sizeof(time_string)-1,DSC$K_DTYPE_T,DSC$K_CLASS_S,&time_string};

    if (!CHECK_ERR("ztime: sys$asctim",
    sys$asctim(0, &t, 0, 0))) return(-1);
    time_string[t.dsc$w_length] = '\0';
    *s = &time_string;
#else
    char *asctime();
    struct tm *tp;

    time(&clock);
    tp = localtime(&clock);
    *s = asctime(tp);
#endif /* bogus */
#else /* not COMMENT */
/*
 Apparently ctime() is available in old C libraries, even though asctime()
 is not.  Let's use the same method for all versions.
*/
    time(&clock);
    *s = ctime(&clock);
#endif /* COMMENT */
}

/*  C O N G M  --  Get console terminal modes.  */

/*
 Saves current console mode, and establishes variables for switching between
 current (presumably normal) mode and other modes.
*/
int
congm() {
    char s[] = CONDEV_COLON;
    struct itmlst dviitm[] = { {4,DVI$_DEVCLASS,(char *)&dviitm[0].adr,0},
            {0,0,0,0}};
#ifdef COMMENT /* old */
    struct dsc$descriptor_s
      r = {sizeof(s),DSC$K_DTYPE_T,DSC$K_CLASS_S,(char *)&s};
#else /* from ttj */
    struct dsc$descriptor_s
      devnam = {sizeof(s)-1,DSC$K_DTYPE_T,DSC$K_CLASS_S,s};
#endif /* COMMENT */

    debug(F101,"congm cgmf","",cgmf);
    if (cgmf) return(-1);        /* If called already, then nop */

    if (!CHECK_ERR("congm: sys$getdviw",
    sys$getdviw(0, 0, &devnam, &dviitm, &wrk_iosb, 0, 0, 0))) return(-1);
    debug(F101, "congm: devclass", "", (unsigned long int) dviitm[0].adr);
    if ((unsigned long int) dviitm[0].adr != DC$_TERM) {
    batch = 1;
    }
#ifdef COMMENT                /* Let's try it anyway... */
      else {
#endif /* COMMENT */
    /*
       NOTE: Reportedly, when C-Kermit is run from a .COM file
           it complains "Sorry, terminal type not supported: vt300-80".
           Reportedly, the cure is to execute the following code always,
           not just when the if condition above is false; i.e. just get
           rid of {, } else {, and }.  But some of the following system
           calls look like they might be dangerous on non-terminals,
           so widespread testing would be needed.  Better safe than sorry.
        */
        debug(F101, "congm: conchn", "", conchn);
    if (!conchn) {            /* Get console channel */
        $DESCRIPTOR(sys_input, CONDEV_COLON);
        conchn = vms_assign_channel(&devnam);
    }
    if (!conchn)
      return(-1);
        if (!CHECK_ERR("congm: sys$qiow",
        sys$qiow(QIOW_EFN, conchn, IO$_SENSEMODE, &wrk_iosb, 0, 0,
                 &ccold, sizeof(ccold), 0, 0, 0, 0))) return(-1);
        ccraw = cccbrk = ccold;
#ifdef COMMENT
    }
#endif /* COMMENT */
    cgmf = 1;                /* Flag that we got them. */
    return(0);
}

/*  C O N C B --  Put console in cbreak mode.  */

/*  Returns 0 if ok, -1 if not  */

int
#ifdef CK_ANSIC
concb(char esc)
#else
concb(esc) char esc;
#endif /* CK_ANSIC */
/* concb */ {
    int x;

    debug(F101,"concb batch","",batch);
    if (batch) return(0);
    if (!cgmf) congm();            /* Get modes if necessary. */
    escchr = esc;            /* Make this available to other fns */
    ckxech = 1;                /* Program can echo characters */
/*
  Note: PASTHRU / PASSALL is what is preventing the Ctrl-C trap in the
  main program from working.  This business can be removed without any effect
  at all on the command parser -- everything still works: completion, ?-help,
  editing, etc.  The only problem is that Ctrl-Y is not trapped, so the
  program dies and leaves the terminal in no-echo mode.
*/
    cccbrk.extended |= TT2$M_PASTHRU | TT2$M_ALTYPEAHD;
    if (parity)
      cccbrk.basic |= TT$M_NOECHO;
    else
      cccbrk.basic |= TT$M_NOECHO | TT$M_EIGHTBIT;
    cccbrk.basic &= ~TT$M_ESCAPE;    /* Disable escape-seq processing */
    cccbrk.extended &= ~TT2$M_LOCALECHO; /* and local echoing */
    if (!CHECK_ERR("concb: sys$qiow",
    sys$qiow(QIOW_EFN, conchn, IO$_SETMODE, &wrk_iosb, 0, 0,
                 &cccbrk, sizeof(cccbrk), 0, 0, 0, 0))) return(-1);
    debug(F100,"concb ok","",0);
    return(0);
}

/*  C O N B I N  --  Put console in binary mode  */

/*  Returns 0 if ok, -1 if not  */

int
#ifdef CK_ANSIC
conbin(char esc)
#else
conbin(esc) char esc;
#endif /* CK_ANSIC */
/* conbin */ {

    debug(F101,"conbin batch","",batch);
    if (batch) return(0);
    if (!cgmf) congm();            /* Get modes if necessary. */
    escchr = esc;            /* Make this available to other fns */
    ckxech = 1;                /* Program can echo characters */
    ccraw.extended |= TT2$M_PASTHRU | TT2$M_ALTYPEAHD;
    ccraw.basic &= ~TT$M_ESCAPE;    /* Disable escape-seq processing */
    ccraw.extended &= ~TT2$M_LOCALECHO;    /* and local echoing */
    if (parity)
      ccraw.basic |= TT$M_NOECHO;
    else
      ccraw.basic |= TT$M_NOECHO | TT$M_EIGHTBIT;
#ifdef COMMENT
    ccraw.basic &= ~(TT$M_HOSTSYNC | TT$M_TTSYNC);
#endif /* COMMENT */
    if (!CHECK_ERR("conbin: sys$qiow",
    sys$qiow(QIOW_EFN, conchn, IO$_SETMODE, &wrk_iosb, 0, 0,
                 &ccraw, sizeof(ccraw), 0, 0, 0, 0))) return(-1);
    return(0);
}


/*  C O N R E S  --  Restore the console terminal  */

int
conres() {
    debug(F101,"conres cgmf","",cgmf);
    if (!cgmf) return(0);        /* Do nothing if modes unknown */
    if (batch) return(0);

    msleep(250);
    ckxech = 0;                /* System should echo chars */
    if (!CHECK_ERR("conres: sys$qiow",
    sys$qiow(QIOW_EFN, conchn, IO$_SETMODE, &wrk_iosb, 0, 0,
    &ccold, sizeof(ccold), 0, 0, 0, 0))) return(-1);
    debug(F100,"conres ok","",0);
    return(0);
}


/*  C O N R E S N E --  Restore the console terminal with No Echo */

int
conresne() {
    debug(F101,"conresne cgmf","",cgmf);
    if (!cgmf) return(0);        /* Don't do anything if modes unk */
    if (batch) return(0);

    msleep(250);
    ckxech = 1;                /* Program should echo chars */

    cctmp = ccold;
    cctmp.basic |= TT$M_NOECHO;
    if (!CHECK_ERR("conres: sys$qiow",
    sys$qiow(QIOW_EFN, conchn, IO$_SETMODE, &wrk_iosb, 0, 0,
    &cctmp, sizeof(cctmp), 0, 0, 0, 0))) return(-1);
    debug(F100,"conresne ok","",0);
    return(0);
}

/*  C O N O C  --  Output a character to the console terminal  */

int
#ifdef CK_ANSIC
conoc(char c)
#else
conoc(c) char c;
#endif /* CK_ANSIC */
/* conoc */ {
    if (batch) putchar(c);
    else
    if (!CHECK_ERR("conoc: sys$qiow",
        sys$qiow(QIOW_EFN, conchn, IO$_WRITEVBLK|IO$M_BREAKTHRU,
             &wrk_iosb, 0, 0, &c, 1, 0, 0, 0, 0))) return(-1);
    return(1);
}

/*  C O N X O  --  Write x characters to the console terminal  */

int
conxo(x,s) char *s; int x; {
    if (batch) fprintf(stdout, "%.*s", x, s);
    else if (!CHECK_ERR("conxo: sys$qiow",
    sys$qiow(QIOW_EFN, conchn, IO$_WRITEVBLK|IO$M_BREAKTHRU,
         &wrk_iosb, 0, 0, s, x, 0, 0, 0, 0))) return(-1);
    return(0);
}

/*  C O N O L  --  Write a line to the console terminal  */

int
conol(s) char *s; {
    int len;

    if (batch) fputs(s, stdout);
    else {
    len = strlen(s);
    if (!CHECK_ERR("conol: sys$qiow",
        sys$qiow(QIOW_EFN, conchn, IO$_WRITEVBLK|IO$M_BREAKTHRU, &wrk_iosb,
             0, 0, s, len, 0, 0, 0, 0))) return(-1);
    }
    return(1);
}

/*  C O N O L A  --  Write an array of lines to console, with CRLFs added */

int
conola(s) char *s[]; {
    int i;
    char t[100], *cp;

    for (i=0 ; *s[i] ; i++) {
    strncpy(t,s[i],100);
    for (cp = t + strlen(t); --cp >= t;) {
        if (*cp != '\n' && *cp != '\r') {
        cp++;
        *cp++ = '\r'; *cp++ = '\n'; *cp++ = '\0';
        break;
        }
    }
    if (conol(t) < 0) return(-1);
    }
    return(0);
}

/*  C O N O L L  --  Output a string followed by CRLF  */

int
conoll(s) char *s; {
    int x;
    x = conol(s);
    if (x > -1)
      x = conol("\r\n");
    return(x);
}


/*  C O N C H K  --  Check if characters available at console  */

int
conchk() {
    struct {
    unsigned short count;
    unsigned char first;
    unsigned char reserved1;
    long reserved2;
    } t;

    if (batch) return(0);
    return(CHECK_ERR("conchk: sys$qiow",
    sys$qiow(QIOW_EFN, conchn, IO$_SENSEMODE|IO$M_TYPEAHDCNT, &wrk_iosb,
         0, 0, &t, sizeof(t), 0, 0, 0, 0)) ? t.count : 0);
}

/*  C O N I N C  --  Get a character from the console  */

int
coninc(timo) int timo; {        /* Timo > 0 = timeout in seconds. */
    int n = 0;
    unsigned char ch;
    int func, mask;

    debug(F101,"coninc timo","",timo);
    debug(F101,"coninc con_queued","",con_queued);

    if (batch)
      return(getchar());

    mask = 1 << CON_EFN;

    if (con_queued) {        /* If a console read was already posted... */
                /* e.g. by contti() ... */
    if (timo > 0) {                /* If a timeout was specified... */
        struct { int hi, lo; } qtime;   /* Set a timer... */
        qtime.hi = -10*1000*1000*timo;  /* in VMS "delta-time" notation. */
/*
  If the timo value is big enough to make the delta-time overflow an integer,
  substitute something useful.
*/
        if (qtime.hi > 0)        /* Did it go positive? */
          qtime.hi = -0x7fffffff;    /* Yes, so fudge it. */
        qtime.lo = -1;
        sys$setimr(TIM_EFN, &qtime, 0, 0, 0); /* Specify event flag. */
        mask |= TIM_EFN;        /* And add it to read mask. */
    }
    sys$wflor(CON_EFN, mask);    /* Wait for SETIMR to complete. */
    sys$readef(CON_EFN, &mask);    /* Read event flags. */
    if (mask & (1 << CON_EFN)) {    /* We got a console event? */
        ch = (unsigned char) conch;    /* (see contti() about this...) */
        CHECK_ERR("coninc: coniosb.status", coniosb.status);
        con_queued = 0;
    } else {            /* We didn't */
        ch = -1;            /* So indicate that coninc() ... */
        vms_status = SS$_TIMEOUT;    /*  timed out. */
    }
    } else {                /* Console read not already posted */
    func = IO$_READVBLK | IO$M_NOFILTR;
    if (timo > 0) func |= IO$M_TIMED;
    CHECK_ERR("coninc: sys$qiow",
      sys$qiow(QIOW_EFN, conchn, func, &wrk_iosb,0,0,&ch,1,timo,0,0,0));
    }
    if (vms_status & 1) {
    if (wrk_iosb.status == SS$_TIMEOUT)
      return(-1);
    else return( (ch == '\r') ? '\n' : ch );
    } else return(-1);
}


/*  V M S _ G E T C H A R -- get a character from the console (no echo).
 *    Since we use raw reads, we must check for ctrl/c, ctrl/y and
 *    ctrl/z ourselves.  We probably should post a "mailbox" for
 *    ctrl/c and ctrl/y so the poor user can abort a runaway Kermit.
 *    Note: this routine intends for ctrl/z (eof) to be "permanent".
 *    Currently, no kermit routine calls "clearerror".  If this
 *    changes, the following code must be rewritten.
 */

int
vms_getchar() {
    register unsigned int ch;
    static int ateof = 0;

    if (ateof)
      return (EOF);
    ch = coninc(0);
    switch (ch) {
      case ('Y' - 64):
      case ('C' - 64):
#ifndef COMMENT
/*
  Just call the same handler that signal(SIGINT,xxx) would have invoked
  if Ctrl-C had been trapped.  The pointer to the handler was saved in
  cctrap by conint().
*/
    if (cctrap)
      (*cctrap)(SIGINT,0);
#else
    ttclos(ttyfd);            /* Close down other terminal    */
    conres();            /* And cleanup console modes    */
    exit(SS$_ABORT);        /* Fatal exit.            */
#endif /* COMMENT */
      case ('Z' - 64):
    ateof = 1;
    return (EOF);

      default:
    return (ch);
    }
}

/*  C O N T T I  --  Get character from console then from tty  */
/*
  This is used in conect() when NO_FORK is defined.
  src is returned with 1 if the character came from the comm. line,
  0 if it was from the console, and with -1 if there was any error.
*/
#ifdef TCPIPLIB
/*
 * Network/console read posted?
 */
static int    nettty_queued    = 0;
static int    netcon_queued    = 0;
#endif /* TCPIPLIB */

int
contti(c, src) int *c, *src; {

#ifndef TCPIPLIB
    int mask = 1<<CON_EFN | 1<<TTY_EFN;
    int x; unsigned char cc;

#else /* TCPIPLIB */

#ifdef CMU_TCPIP
    int s;                    /* select status */
    fd_set exceptfds;                /* select exceptions */
    static struct timeval timeout;        /* for non-blocking select */
#endif /* CMU_TCPIP */

#define NET_EFN 7                /* Network event flag */

    int                mask;        /* Event flag mask */

    static CHAR            concc;        /* Console and network data */
    static CHAR            netcc;

    static struct iosb_struct    net_iosb;
    static struct iosb_struct    con_iosb;    /* IO status blocks */

/*
  Buffered network data, count, next character.  Declared in CKCNET.C ...
*/
    extern CHAR            ttibuf[];
    extern int            ttibn;
    extern int            ttibp;
#endif /* TCPIPLIB */

    *src = -1;                /* Assume there was an error */

#ifdef TCPIPLIB
    if (network) {            /* For active network connections */
    debug(F100,"contti network","",0);

    if (ttibn > 0) {
        /*
         * Handle the case where data remains in our "internal" buffer.
         * We need to:
         *
         *    -- Handle the console keyboard (is a character ready?)
         *    -- Return one character from the network buffer if not
         *
         * Post a new console read if necessary
         */
            if (!netcon_queued) {
#ifdef CMU_TCPIP
            cmu_stdin_read(IO$_READVBLK, &concc, 1, 0, 0);
#else
                if (!CHECK_ERR("contti: console sys$qio",
                            sys$qio(CON_EFN, conchn, IO$_READVBLK,
                    &con_iosb, 0, 0, &concc, 1,
                    0, 0, 0, 0))) return(-1);
#endif /* CMU_TCPIP */
                    netcon_queued = 1;
        }
        /*
         * Console character ready?
         */
#ifdef CMU_TCPIP
        exceptfds = mask = 1;
        if (select(1, &mask, 0, &exceptfds, &timeout) == 1) {
            /*
             * check for error
             */
            if (FD_ISSET(0,&exceptfds)) {
                return(-1);
            }
#else
               (void) sys$readef(CON_EFN, &mask);

            if (mask & (1 << CON_EFN)) {
#endif /* CMU_TCPIP */
            /*
             * Yes, return it
             */
            netcon_queued = 0;
#ifndef CMU_TCPIP
             if (!CHECK_ERR("contti: con_iosb.status",
                    con_iosb.status)) return(-1);
#endif /* CMU_TCPIP */
            *c   = concc & 0xff;
                *src = 0;
                return(1);
        }
        /*
         * No console data; return buffered network character
         */
        ttibn--;
        *c   = ttibuf[ttibp++];
        *src = 1;
        return(1);
    }
    /*
     * No buffered data; post network and console reads
     */
        if (!nettty_queued) {
#ifdef CMU_TCPIP
        /*
         * network read is always posted
         */
#else
/*     -lt.  1992-09-14  begin */
/* All the event flag numbers should be obtained using lib$get_ef().
 * Using hard coded numbers, especially < 31 is tres dangereuse!!!
 * Be careful, one must also change the event flag cluster used by
 * sys$readef. It is *not* just a simple matter of changing a few #defines.
 *
 * At least for DEC TCP/IP Services, socket calls return a proper file
 * descriptor (fd).  OpenVMS system services require a channel
 * (from sys$assign).  The two are *not* the same.  The call vaxc$get_sdc()
 * maps from a DEC TCP/IP fd to a channel.
 *
 * This is "gag me with a spoon" code, but it gets thing up and running.
 *
 */
#ifdef DEC_TCPIP

    {
       static int last_ttyfd = -1;
       static short int net_chan = -1;

    if (ttyfd != last_ttyfd){
        last_ttyfd = ttyfd;
#ifdef COMMENT
#ifdef __DECC
        net_chan = (short) decc$get_sdc(last_ttyfd);
#else
#ifdef VAXC
        net_chan = vaxc$get_sdc(last_ttyfd);
#else
#        error CALL TO GET_SDC requires DECC or VAXC compiler!
#endif    /* VAXC */
# endif    /* DECC */
#else /* COMMENT */
        net_chan = GET_SDC(last_ttyfd);
#endif /* COMMENT */
            }

            if (!CHECK_ERR("contti: network sys$qio",
                    sys$qio(NET_EFN, net_chan, IO$_READVBLK, &net_iosb, 0, 0,
                            &netcc, 1, 0, 0, 0, 0))) return(-1);
        }

#else /* Not DEC_TCPIP */

            if (!CHECK_ERR("contti: network sys$qio",
                    sys$qio(NET_EFN, ttyfd, IO$_READVBLK, &net_iosb, 0, 0,
                            &netcc, 1, 0, 0, 0, 0))) return(-1);
#endif /* DEC_TCPIP */
#endif /* CMU_TCPIP */
        nettty_queued = 1;
    }

        if (!netcon_queued) {
#ifdef CMU_TCPIP
        cmu_stdin_read(IO$_READVBLK, &concc, 1, 0, 0);
#else
            if (!CHECK_ERR("contti: console sys$qio",
                    sys$qio(CON_EFN, conchn, IO$_READVBLK, &con_iosb,
                0, 0, &concc, 1, 0, 0, 0, 0))) return(-1);
#endif /* CMU_TCPIP */
            netcon_queued = 1;
    }
    /*
     * Wait for a character
     */
#ifdef CMU_TCPIP
    exceptfds = mask = (1 | (1<<ttyfd));
    s = select(ttyfd, &mask, 0, &exceptfds, 0); /*a blocking select*/

    if (FD_ISSET(0,&exceptfds))
        return(-1);

    if (FD_ISSET(ttyfd,&exceptfds))
        return(-1);

    if (FD_ISSET(0,&mask)) {
        *c         = concc & 0xff;
        *src       = 0;
        netcon_queued = 0;
    }
    else {
        if (FD_ISSET(ttyfd,&mask)) {
        s = cmu_read(ttyfd, &netcc, 1);
        if (s <= 0)
            return(-1);
        *c         = netcc & 0xff;
        *src       = 1;
        nettty_queued = 0;
            }
    }
#else
        mask = (1 << CON_EFN) | (1 << NET_EFN);

        if (!CHECK_ERR("contti: sys$wflor",
                    sys$wflor(CON_EFN, mask))) return(-1);

        if (!CHECK_ERR("contti: sys$readef",
                    sys$readef(CON_EFN, &mask))) return(-1);

        if (mask & (1 << CON_EFN)) {
        /*
         * Console
         */
            if (!CHECK_ERR("contti: con_iosb.status",
                con_iosb.status)) return(-1);

            *c         = concc & 0xff;
        *src       = 0;
            netcon_queued = 0;

        } else if (mask & (1 << NET_EFN)) {
        /*
         * Network
         */
        if (!(net_iosb.status & 1)) {
        /*
         * Network read error
         */
#ifdef WINTCP
        _$set_vaxc_error(SS$_NORMAL, net_iosb.status);
        win$perror("contti: net_iosb.status");
#else
#ifdef MULTINET
#ifdef COMMENT
/*
  When user hangs up, this prints an unnecessary scary message,
  like "Operation would block."
*/
        socket_perror("contti: net_iosb.status");
#endif /* COMMENT */
#endif /* MULTINET */
#endif /* WINTCP */
        return(-1);
        }

        if (net_iosb.size == 0) {
        /*
         * Handle reset from remote
         */
        return(-1);
        }
        *c         = netcc & 0xff;
        *src       = 1;
            nettty_queued = 0;
        }
#endif /* CMU_TCPIP */
    } else                /* Not network */
#endif /* TCPIPLIB */

/*
  Should we worry about a network connection that's running under BATCH ?
*/
    if (batch) {            /* Batch? */
    debug(F100,"contti batch","",0);
    if ((*c = getchar()) != EOF) {
        *src = 0;
    } else {
        *src = 1;
        *c = ttinc(0);
    }
    } else {                /* Interactive but not network */

#ifdef TTXBUF
    if (ttxbn > 0) {        /* Buffered port chars available */

/* Post a read on the console if one is not posted already */

        if (!con_queued) {
        if (!CHECK_ERR("contti: console sys$qio",
                 sys$qio(CON_EFN, conchn, IO$_READVBLK,
                     &coniosb, 0, 0,
                     &conch, 1, 0, 0, 0, 0)))
          return(-1);
        con_queued = 1;
        }

/* See if a console character has been read and if so, return it.  */

        (void) sys$readef(CON_EFN, &mask);
        if (mask & (1 << CON_EFN)) {
        con_queued = 0;
        if (!CHECK_ERR("contti: coniosb.status",
                   coniosb.status))
          return(-1);
        *c   = conch & 0xff;
        *src = 0;
        return(1);
        }

/* No console character, so return buffered port character */

        *c = ttinc(0);
        *src = 1;
        return(1);
    }

/* No buffered port data; post both network and console reads... */

#endif /* TTXBUF */

        mask = 1<<CON_EFN | 1<<TTY_EFN;    /* Event mask */

    debug(F101,"contti interactive mask","",mask);

        if (!con_queued) {        /* Console read not queued... */
            if (!CHECK_ERR("contti: console sys$qio",
            sys$qio(CON_EFN, conchn, IO$_READVBLK, &coniosb, 0, 0,
                    &conch, 1, 0, 0, 0, 0))) return(-1);
        con_queued = 1;
        debug(F100,"contti con_queued","",0);
    }
        if (!tt_queued) {        /* Port read not queued */
            if (!CHECK_ERR("contti: tty sys$qio",
            sys$qio(TTY_EFN, ttychn, IO$_READVBLK, &ttiosb, 0, 0,
                    &ttch, 1, 0, 0, 0, 0))) return(-1);
        tt_queued = 1;
        debug(F100,"contti tt_queued","",0);
    }

/* Wait for one of the queued reads to complete */

        if (!CHECK_ERR("contti: sys$wflor",
            sys$wflor(CON_EFN, mask))) return(-1);
    debug(F100,"contti sys$wflor ok","",0);

/* Read the event flags to see which read was completed */

        if (!CHECK_ERR("contti: sys$readef",
            sys$readef(CON_EFN, &mask))) return(-1);
    debug(F100,"contti sys$readef ok","",0);


/* Return the character with the appropriate source (src) indicator */

        if (!(*src = ((mask & 1<<CON_EFN) ? 0 : 1))) {
            *c = conch;
            CHECK_ERR("contti: coniosb.status", coniosb.status);
            con_queued = 0;
        } else {
            *c = (ttprty ? ttch & 0177 : ttch);
        if (ttiosb.status == SS$_HANGUP) {
        fprintf(stderr,"\n%%CKERMIT-F-HANGUP, data set hang-up");
        *src = -1;
        return(1);
        }
            CHECK_ERR("contti: ttiosb.status", ttiosb.status);
            tt_queued = 0;
        }
        if (!(vms_status & 1)) *src = -1;
    }
    debug(F101,"contti *src","",*src);
    return((*src > -1) ? 1 : 0);
}

/*
  C A N C I O
  Cancel pending I/O requests on console and communication device.
*/
VOID
cancio()  {
#ifdef NETCONN
    if (network) {
#ifdef TCPIPLIB
#ifdef DEC_TCPIP
    short int net_chan = -1;
#ifdef COMMENT
#ifdef __DECC
    net_chan = (short) decc$get_sdc(ttyfd);
#else  /* !__DECC */
#ifdef VAXC
    net_chan = vaxc$get_sdc(ttyfd);
#else  /* !VAXC */
# error CALL TO GET_SDC requires DECC or VAXC compiler!
#endif /* VAXC */
#endif /* __DECC */
#else  /* COMMENT */
    net_chan = GET_SDC(ttyfd);
#endif /* COMMENT */
        if (nettty_queued) (void) sys$cancel(net_chan);
#else  /* DEC_TCPIP */
#ifdef CMU_TCPIP
    /* not going to do this when CMU is the network transport.
     * the sys$cancel will cause the channel to shutdown
     *
     * if (nettty_queued) (void) sys$cancel(cmu_get_sdc(ttyfd));
     */
#else  /* !CMU_TCPIP */
       if (nettty_queued) (void) sys$cancel(ttyfd);
#endif /* CMU_TCPIP */
#endif /* DEC_TCPIP */
        if (netcon_queued) (void) sys$cancel(conchn);

        netcon_queued = 0;
        nettty_queued = 0;
    return;
#else /* Not TCPIPLIB */
    return;
#endif /* TCPIPLIB */
    }
#endif /* NETCONN */

    if (!batch) {
        CHECK_ERR("cancio: console sys$cancel",
            sys$cancel(conchn));
        CHECK_ERR("cancio: tty sys$cancel",
            sys$cancel(ttychn));
        con_queued = 0;
        tt_queued = 0;
    }
}

/* get_qio_maxbuf_size()
 *
 * Get maximum size of QIO that can occur without getting the dreaded
 * exceeded quota status.
 */

#ifndef SYI$_MAXBUF
#define SYI$_MAXBUF 4175
#endif /* SYI$_MAXBUF */

int
get_qio_maxbuf_size(ttychn) unsigned long int ttychn; {
    unsigned char *tmpbuf;
    int unsigned long max=0;
    struct itmlst syiitm[] = { {2,SYI$_MAXBUF,(char *)&max,0},
            {0,0,0,0}};

    if (!ttychn) return(-1);

    if (!CHECK_ERR("get_qio_maxbuf_size: sys$getsyiw",
    sys$getsyiw(     0    /* efn */
            ,0    /* csidadr */
            ,0    /* nodename */
            ,&syiitm /* itmlst */
            ,&wrk_iosb /* iosb */
            ,0    /* astadr */
            ,0)))    /* astprm */
        exit(SS$_ABORT);        /* Fatal exit */

    if (!(tmpbuf = malloc(max)))
    return(0);

    for (; max > 0; max -= 16) {
    if (!test_qio(ttychn,max,tmpbuf)) /* (was &tmpbuf, caused crash) */
    {
        free(tmpbuf);
        return(max);
    }
    }

    free(tmpbuf);
    printf("\n%%CKERMIT-F-get_qio_maxbuf_size, Could not get maxbuf size\n");
    exit(SS$_ABORT);        /* Fatal exit */
}

int
test_qio(ttychn,max,dest)
unsigned long int ttychn;
long int max;
unsigned char *dest;
{
    static int trmmsk[2] = {0,0};

/*    trmmsk[1] = 1 << eol; */

    vms_status = sys$qiow(QIOW_EFN, ttychn, IO$_READVBLK|IO$M_TIMED,
              &wrk_iosb, 0, 0, dest, max, 0, &trmmsk, 0, 0);
    return( !(vms_status & 1) ||
    (!(wrk_iosb.status & 1)) && wrk_iosb.status != SS$_TIMEOUT);
}


/*
 * Flush tt output buffer
 */

int
ttfluo() {

    long n=0;

#ifdef NETCONN
    if (network) return(0);
#endif /* NETCONN */

    if (!ttychn) return(-1);        /* Not open. */

    if (!CHECK_ERR("ttfluo: sys$qiow",
    sys$qiow(QIOW_EFN, ttychn, IO$_READVBLK|IO$M_TIMED|IO$M_PURGE,
         &wrk_iosb, 0, 0, &n, 0, 0, 0, 0, 0))) {
    perror("flush failed");
    return(-1);
    }
    return(0);
}

/*  T T G M D M  --  Get modem signals  */
/*
 Looks for the modem signals CTS, DSR, and CTS, and returns those that are
 on in as its return value, in a bit mask as described for ttwmdm.  Returns:
 -3 Not implemented
 -2 if the line does not have modem control
 -1 on error.
 >= 0 on success, with a bit mask containing the modem signals that are on.
*/
int
ttgmdm() {
    struct {
    unsigned char type;
    unsigned char spare1;
    unsigned char modem;
    unsigned char spare2;
    unsigned long filler;
    } mdminfo;
    int retval;

#ifdef NETCONN
    if (network) return(-2);
#endif /* NETCONN */
    vms_status = sys$qiow(QIOW_EFN, ttychn, IO$_SENSEMODE|IO$M_RD_MODEM,
              &wrk_iosb, 0, 0, &mdminfo, 0, 0, 0, 0, 0);

    if (vms_status != SS$_NORMAL) {
    debug(F101,"ttgmdm serious error, status","",vms_status);
    return(-1);
    }

    debug(F101,"ttgmdm iosb","",wrk_iosb.status);
    debug(F101,"ttgmdm type","",mdminfo.type);
    debug(F101,"ttgmdm modem","",mdminfo.modem);

    if (wrk_iosb.status != SS$_NORMAL) {
    debug(F101,"ttgmdm iosb error, status","",wrk_iosb.status);
    return(-1);
    }

#ifdef DT$_LAT
    if (mdminfo.type == DT$_LAT) {
    debug(F101,"ttgmdm LAT port, no modem control","",0);
    return(-2);
    }
#endif /* DT$_LAT */

    if (mdminfo.type == 0) {
    debug(F101,"ttgmdm unknown driver, modem","",mdminfo.modem);
    return(-2);
    }

    retval = BM_DTR | BM_RTS;        /* Not visible, set by TTDRIVER */
    if (mdminfo.modem & TT$M_DS_CTS)
    retval |= BM_CTS;
    if (mdminfo.modem & TT$M_DS_DSR)
    retval |= BM_DSR;
    if (mdminfo.modem & TT$M_DS_CARRIER)
    retval |= BM_DCD;
    if (mdminfo.modem & TT$M_DS_RING)
    retval |= BM_RNG;
    return(retval);
}

/*
  Return serial communication device speed.  Speed is retreived from a qiow
  initially.  It is then changed only at user request.  (Yes, but it would
  still be better to do another qiow here to actually read the speed from the
  device so we know it is what we think it should be!)
*/
long
ttgspd() {
    extern int speed;
#ifdef NETCONN
    if (network) return(-1);        /* -1 if network connection */
#endif /* NETCONN */
    return(ttspeed);
}


/*  T T S C A R R  --  Set ttcarr variable, controlling carrier handling.
 *
 *  0 = Off: Always ignore carrier. E.g. you can connect without carrier.
 *  1 = On: Heed carrier, except during dialing. Carrier loss gives disconnect.
 *  2 = Auto: For "modem direct": The same as "Off".
 *            For real modem types: Heed carrier during connect, but ignore
 *                it anytime else.  Compatible with pre-5A C-Kermit versions.
 *
 * As you can see, this setting does not affect dialing, which always ignores
 * carrier (unless there is some special exception for some modem type).  It
 * does affect ttopen() if it is set before ttopen() is used.  This setting
 * takes effect on the next call to ttopen()/ttpkt()/ttvt().  And they are
 * (or should be) always called before any communications is tried, which
 * means that, practically speaking, the effect is immediate.
 *
 * Of course, nothing of this applies to remote mode (xlocal = 0).
 *
 * Someone has yet to uncover how to manipulate the carrier in the BSD
 * environment (or any non-termio using environment).  Until that time, this
 * will simply be a no-op for BSD.
 *
 * Note that in previous versions, the carrier was most often left unchanged
 * in ttpkt()/ttvt() unless they were called with DIALING or CONNECT.  This
 * has changed.  Now it is controlled by ttcarr in conjunction with these
 * modes.
 */
int
ttscarr(carrier) int carrier; {

    return(-1);
}

int
psuspend(x) int x; {

    return(-1);
}

#ifdef CK_CURSES
/*
  tgetent() support for VMS curses emulation.
  Used by all three VMS fullscreen methods.
  Called from "SET FILE DISPLAY FULLSCREEN" in ckuus7.c.
*/
int isvt52 = 0;                /* VT52/VT1xx flag */

int
tgetent(lp, term) char *lp, *term; {
    debug(F101,"tgetent terminal type","",ccold.type);
    debug(F101,"tgetent terminal extended","",ccold.extended);

    if ((ccold.type == DT$_VT5X) || (ccold.type == DT$_VT55)) {
    debug(F100,"tgetent VT5x","",0);
    isvt52 = 1;
    return(1);
    }
    if ((ccold.extended & TT2$M_ANSICRT) == TT2$M_ANSICRT) {
    debug(F100,"tgetent ANSICRT","",0);
    isvt52 = 0;
    return(1);
    }
    if ((ccold.extended & TT2$M_DECCRT) == TT2$M_DECCRT) {
    debug(F100,"tgetent DECCRT","",0);
    isvt52 = 0;
    return(1);
    }
    return(0);                /* Not a supported terminal type */
}
#endif /* CK_CURSES */