xtrn.cpp

/* Synchronet external program support routines */

/****************************************************************************
 * @format.tab-size 4		(Plain Text/Source Code File Header)			*
 * @format.use-tabs true	(see http://www.synchro.net/ptsc_hdr.html)		*
 *																			*
 * Copyright Rob Swindell - http://www.synchro.net/copyright.html			*
 *																			*
 * This program is free software; you can redistribute it and/or			*
 * modify it under the terms of the GNU General Public License				*
 * as published by the Free Software Foundation; either version 2			*
 * of the License, or (at your option) any later version.					*
 * See the GNU General Public License for more details: gpl.txt or			*
 * http://www.fsf.org/copyleft/gpl.html										*
 *																			*
 * For Synchronet coding style and modification guidelines, see				*
 * http://www.synchro.net/source.html										*
 *																			*
 * Note: If this box doesn't appear square, then you need to fix your tabs.	*
 ****************************************************************************/

#include "sbbs.h"
#include "cmdshell.h"
#include "telnet.h"

#include <signal.h>			// kill()

#ifdef __unix__
	#include <sys/wait.h>	// WEXITSTATUS

	#define TTYDEFCHARS		// needed for ttydefchars definition
	#include <sys/ttydefaults.h>	// Linux - it's motherfucked.
#if defined(__FreeBSD__)
	#include <libutil.h>	// forkpty()
#elif defined(__OpenBSD__) || defined(__NetBSD__) || defined(__DARWIN__)
	#include <util.h>
#elif defined(__linux__)
	#include <pty.h>
#elif defined(__QNX__)
#if 0
	#include <unix.h>
#else
	#define NEEDS_FORKPTY
#endif
#endif

	#ifdef NEEDS_FORKPTY
	#include <grp.h>
	#endif

	#include <termios.h>

/*
 * Control Character Defaults
 */
#ifndef CTRL
	#define CTRL(x)	(x&037)
#endif
#ifndef CEOF
	#define	CEOF		CTRL('d')
#endif
#ifndef CEOL
	#define	CEOL		0xff		/* XXX avoid _POSIX_VDISABLE */
#endif
#ifndef CERASE
	#define	CERASE		0177
#endif
#ifndef CERASE2
	#define	CERASE2		CTRL('h')
#endif
#ifndef CINTR
	#define	CINTR		CTRL('c')
#endif
#ifndef CSTATUS
	#define	CSTATUS		CTRL('t')
#endif
#ifndef CKILL
	#define	CKILL		CTRL('u')
#endif
#ifndef CMIN
	#define	CMIN		1
#endif
#ifndef CQUIT
	#define	CQUIT		034		/* FS, ^\ */
#endif
#ifndef CSUSP
	#define	CSUSP		CTRL('z')
#endif
#ifndef CTIME
	#define	CTIME		0
#endif
#ifndef CDSUSP
	#define	CDSUSP		CTRL('y')
#endif
#ifndef CSTART
	#define	CSTART		CTRL('q')
#endif
#ifndef CSTOP
	#define	CSTOP		CTRL('s')
#endif
#ifndef CLNEXT
	#define	CLNEXT		CTRL('v')
#endif
#ifndef CDISCARD
	#define	CDISCARD 	CTRL('o')
#endif
#ifndef CWERASE
	#define	CWERASE 	CTRL('w')
#endif
#ifndef CREPRINT
	#define	CREPRINT 	CTRL('r')
#endif
#ifndef CEOT
	#define	CEOT		CEOF
#endif
/* compat */
#ifndef CBRK
	#define	CBRK		CEOL
#endif
#ifndef CRPRNT
	#define CRPRNT		CREPRINT
#endif
#ifndef CFLUSH
	#define	CFLUSH		CDISCARD
#endif

#ifndef TTYDEF_IFLAG
	#define TTYDEF_IFLAG    (BRKINT | ICRNL | IMAXBEL | IXON | IXANY)
#endif
#ifndef TTYDEF_OFLAG
	#define TTYDEF_OFLAG    (OPOST | ONLCR)
#endif
#ifndef TTYDEF_LFLAG
	#define TTYDEF_LFLAG    (ECHO | ICANON | ISIG | IEXTEN | ECHOE|ECHOKE|ECHOCTL)
#endif
#ifndef TTYDEF_CFLAG
	#define TTYDEF_CFLAG    (CREAD | CS8 | HUPCL)
#endif
#if defined(__QNX__) || defined(__solaris__) || defined(__NetBSD__)
	static cc_t     ttydefchars[NCCS] = {
        CEOF,   CEOL,   CEOL,   CERASE, CWERASE, CKILL, CREPRINT,
        CERASE2, CINTR, CQUIT,  CSUSP,  CDSUSP, CSTART, CSTOP,  CLNEXT,
        CDISCARD, CMIN, CTIME,  CSTATUS
#ifndef __solaris__
	, _POSIX_VDISABLE
#endif
	};
#endif

#endif	/* __unix__ */

#define XTRN_IO_BUF_LEN 10000	/* 50% of IO_THREAD_BUF_SIZE */

/*****************************************************************************/
/* Interrupt routine to expand WWIV Ctrl-C# codes into ANSI escape sequences */
/*****************************************************************************/
BYTE* wwiv_expand(BYTE* buf, ulong buflen, BYTE* outbuf, ulong& newlen
	,ulong user_misc, bool& ctrl_c)
{
    char	ansi_seq[32];
	ulong 	i,j,k;

    for(i=j=0;i<buflen;i++) {
        if(buf[i]==CTRL_C) {	/* WWIV color escape char */
            ctrl_c=true;
            continue;
        }
        if(!ctrl_c) {
            outbuf[j++]=buf[i];
            continue;
        }
        ctrl_c=false;
        if(user_misc&ANSI) {
            switch(buf[i]) {
                default:
                    strcpy(ansi_seq,"\x1b[0m");          /* low grey */
                    break;
                case '1':
                    strcpy(ansi_seq,"\x1b[0;1;36m");     /* high cyan */
                    break;
                case '2':
                    strcpy(ansi_seq,"\x1b[0;1;33m");     /* high yellow */
                    break;
                case '3':
                    strcpy(ansi_seq,"\x1b[0;35m");       /* low magenta */
                    break;
                case '4':
                    strcpy(ansi_seq,"\x1b[0;1;44m");     /* white on blue */
                    break;
                case '5':
                    strcpy(ansi_seq,"\x1b[0;32m");       /* low green */
                    break;
                case '6':
                    strcpy(ansi_seq,"\x1b[0;1;5;31m");   /* high blinking red */
                    break;
                case '7':
                    strcpy(ansi_seq,"\x1b[0;1;34m");     /* high blue */
                    break;
                case '8':
                    strcpy(ansi_seq,"\x1b[0;34m");       /* low blue */
                    break;
                case '9':
                    strcpy(ansi_seq,"\x1b[0;36m");       /* low cyan */
                    break;
            }
            for(k=0;ansi_seq[k];k++)
                outbuf[j++]=ansi_seq[k];
        }
    }
    newlen=j;
    return(outbuf);
}

static void petscii_convert(BYTE* buf, ulong len)
{
    for(ulong i=0; i<len; i++) {
		buf[i] = cp437_to_petscii(buf[i]);
	}
}

static bool native_executable(scfg_t* cfg, const char* cmdline, long mode)
{
	char*	p;
	char	str[MAX_PATH+1];
	char	name[64];
	char	base[64];
	unsigned i;

	if(mode&EX_NATIVE)
		return true;

	if(*cmdline == '?' || *cmdline == '*')
		return true;

    SAFECOPY(str,cmdline);				/* Set str to program name only */
	truncstr(str," ");
    SAFECOPY(name,getfname(str));
	SAFECOPY(base,name);
	if((p=getfext(base))!=NULL)
		*p=0;

    for(i=0;i<cfg->total_natvpgms;i++)
        if(stricmp(name,cfg->natvpgm[i]->name)==0
		|| stricmp(base,cfg->natvpgm[i]->name)==0)
            break;
    return(i<cfg->total_natvpgms);
}

#define XTRN_LOADABLE_MODULE(cmdline,startup_dir)			\
	if(cmdline[0]=='*')		/* Baja module or JavaScript */	\
		return(exec_bin(cmdline+1,&main_csi,startup_dir));
#ifdef JAVASCRIPT
	#define XTRN_LOADABLE_JS_MODULE(cmdline,mode,startup_dir)	\
	if(cmdline[0]=='?' && (mode&EX_SH))						\
		return(js_execxtrn(cmdline+1, startup_dir));		\
	if(cmdline[0]=='?')										\
		return(js_execfile(cmdline+1,startup_dir));
#else
	#define XTRN_LOADABLE_JS_MODULE
#endif

#ifdef _WIN32

#include "execvxd.h"	/* DOSXTRN.EXE API */

extern SOCKET node_socket[];

/*****************************************************************************/
// Expands Single CR to CRLF
/*****************************************************************************/
BYTE* cr_expand(BYTE* inbuf, ulong inlen, BYTE* outbuf, ulong& newlen)
{
	ulong	i,j;

	for(i=j=0;i<inlen;i++) {
		outbuf[j++]=inbuf[i];
		if(inbuf[i]=='\r')
			outbuf[j++]='\n';
	}
	newlen=j;
    return(outbuf);
}

static void add_env_var(str_list_t* list, const char* var, const char* val)
{
	char	str[MAX_PATH*2];
	SetEnvironmentVariable(var,NULL);	/* Delete in current process env */
	SAFEPRINTF2(str,"%s=%s",var,val);
	strListPush(list,str);
}

/* Clean-up resources while preserving current LastError value */
#define XTRN_CLEANUP												\
	last_error=GetLastError();										\
    if(vxd!=INVALID_HANDLE_VALUE)		CloseHandle(vxd);			\
	if(rdslot!=INVALID_HANDLE_VALUE)	CloseHandle(rdslot);		\
	if(wrslot!=INVALID_HANDLE_VALUE)	CloseHandle(wrslot);		\
	if(start_event!=NULL)				CloseHandle(start_event);	\
	if(hungup_event!=NULL)				CloseHandle(hungup_event);	\
	if(hangup_event!=NULL)				CloseHandle(hangup_event);	\
	SetLastError(last_error)

/****************************************************************************/
/* Runs an external program 												*/
/****************************************************************************/
int sbbs_t::external(const char* cmdline, long mode, const char* startup_dir)
{
	char	str[MAX_PATH+1];
	char*	env_block=NULL;
	char*	env_strings;
	const char* p_startup_dir;
	char	path[MAX_PATH+1];
    char	fullcmdline[MAX_PATH+1];
	char	realcmdline[MAX_PATH+1];
	char	comspec_str[MAX_PATH+1];
	char	title[MAX_PATH+1];
	BYTE	buf[XTRN_IO_BUF_LEN],*bp;
    BYTE 	telnet_buf[XTRN_IO_BUF_LEN*2];
    BYTE 	output_buf[XTRN_IO_BUF_LEN*2];
    BYTE 	wwiv_buf[XTRN_IO_BUF_LEN*2];
    bool	wwiv_flag=false;
    bool	native=false;			// DOS program by default
    bool	was_online=true;
	bool	rio_abortable_save=rio_abortable;
	bool	use_pipes=false;	// NT-compatible console redirection
	BOOL	success;
	BOOL	processTerminated=false;
	uint	i;
    time_t	hungup=0;
	HANDLE	vxd=INVALID_HANDLE_VALUE;
	HANDLE	rdslot=INVALID_HANDLE_VALUE;
	HANDLE	wrslot=INVALID_HANDLE_VALUE;
	HANDLE  start_event=NULL;
	HANDLE	hungup_event=NULL;
	HANDLE	hangup_event=NULL;
	HANDLE	rdoutpipe;
	HANDLE	wrinpipe;
    PROCESS_INFORMATION process_info;
	unsigned long	rd;
    unsigned long	wr;
    unsigned long	len;
    DWORD	avail;
	unsigned long	msglen;
	unsigned long	retval;
	DWORD	last_error;
	DWORD	loop_since_io=0;
	struct	tm tm;
	str_list_t	env_list;

	xtrn_mode = mode;
	lprintf(LOG_DEBUG,"Executing external: %s",cmdline);

	if(startup_dir!=NULL && startup_dir[0] && !isdir(startup_dir)) {
		errormsg(WHERE, ERR_CHK, startup_dir, 0);
		return -1;
	}

	XTRN_LOADABLE_MODULE(cmdline,startup_dir);
	XTRN_LOADABLE_JS_MODULE(cmdline,mode,startup_dir);

	attr(cfg.color[clr_external]);		/* setup default attributes */

	native = native_executable(&cfg, cmdline, mode);

	if(!native && (startup->options&BBS_OPT_NO_DOS)) {
		lprintf((mode&EX_OFFLINE) ? LOG_ERR : LOG_WARNING, "DOS programs not supported: %s", cmdline);
		bprintf("Sorry, DOS programs are not supported on this node.\r\n");
		return -1;
	}

	if(mode&EX_SH || strcspn(cmdline,"<>|")!=strlen(cmdline))
		sprintf(comspec_str,"%s /C ", comspec);
	else
		comspec_str[0]=0;

    if(startup_dir && cmdline[1]!=':' && cmdline[0]!='/'
    	&& cmdline[0]!='\\' && cmdline[0]!='.')
       	SAFEPRINTF3(fullcmdline, "%s%s%s", comspec_str, startup_dir, cmdline);
    else
    	SAFEPRINTF2(fullcmdline, "%s%s", comspec_str, cmdline);

	SAFECOPY(realcmdline, fullcmdline);	// for errormsg if failed to execute

	now=time(NULL);
	if(localtime_r(&now,&tm)==NULL)
		memset(&tm,0,sizeof(tm));

	if(native && mode&EX_STDOUT && !(mode&EX_OFFLINE))
		use_pipes=true;

 	if(native) { // Native (not MS-DOS) external

		if((env_list=strListInit())==NULL) {
			XTRN_CLEANUP;
        	errormsg(WHERE, ERR_CREATE, "env_list", 0);
            return(errno);
		}

		// Current environment passed to child process
		sprintf(str,"%sprotocol.log",cfg.node_dir);
		add_env_var(&env_list,"DSZLOG",str);
		add_env_var(&env_list,"SBBSNODE",cfg.node_dir);
		add_env_var(&env_list,"SBBSCTRL",cfg.ctrl_dir);
		add_env_var(&env_list,"SBBSDATA",cfg.data_dir);
		add_env_var(&env_list,"SBBSEXEC",cfg.exec_dir);
		sprintf(str,"%d",cfg.node_num);
		add_env_var(&env_list,"SBBSNNUM",str);
		/* date/time env vars */
		sprintf(str,"%02u",tm.tm_mday);
		add_env_var(&env_list,"DAY",str);
		add_env_var(&env_list,"WEEKDAY",wday[tm.tm_wday]);
		add_env_var(&env_list,"MONTHNAME",mon[tm.tm_mon]);
		sprintf(str,"%02u",tm.tm_mon+1);
		add_env_var(&env_list,"MONTH",str);
		sprintf(str,"%u",1900+tm.tm_year);
		add_env_var(&env_list,"YEAR",str);

		env_strings=GetEnvironmentStrings();
		env_block=strListCopyBlock(env_strings);
		if(env_strings!=NULL)
			FreeEnvironmentStrings(env_strings);
		env_block=strListAppendBlock(env_block,env_list);
		strListFree(&env_list);
		if(env_block==NULL) {
			XTRN_CLEANUP;
        	errormsg(WHERE, ERR_CREATE, "env_block", 0);
            return(errno);
		}

    } else { // DOS external

		// DOS-compatible (short) paths
		char node_dir[MAX_PATH+1];
		char ctrl_dir[MAX_PATH+1];
		char data_dir[MAX_PATH+1];
		char exec_dir[MAX_PATH+1];

		// in case GetShortPathName fails
		SAFECOPY(node_dir,cfg.node_dir);
		SAFECOPY(ctrl_dir,cfg.ctrl_dir);
		SAFECOPY(data_dir,cfg.data_dir);
		SAFECOPY(exec_dir,cfg.exec_dir);

		GetShortPathName(cfg.node_dir,node_dir,sizeof(node_dir));
		GetShortPathName(cfg.ctrl_dir,ctrl_dir,sizeof(node_dir));
		GetShortPathName(cfg.data_dir,data_dir,sizeof(data_dir));
		GetShortPathName(cfg.exec_dir,exec_dir,sizeof(exec_dir));

		SAFEPRINTF(path,"%sDOSXTRN.RET", cfg.node_dir);
		(void)remove(path);

    	// Create temporary environment file
    	SAFEPRINTF(path,"%sDOSXTRN.ENV", node_dir);
        FILE* fp=fopen(path,"w");
        if(fp==NULL) {
			XTRN_CLEANUP;
        	errormsg(WHERE, ERR_CREATE, path, 0);
            return(errno);
        }
        fprintf(fp, "%s\n", fullcmdline);
		fprintf(fp, "DSZLOG=%sPROTOCOL.LOG\n", node_dir);
        fprintf(fp, "SBBSNODE=%s\n", node_dir);
        fprintf(fp, "SBBSCTRL=%s\n", ctrl_dir);
		fprintf(fp, "SBBSDATA=%s\n", data_dir);
		fprintf(fp, "SBBSEXEC=%s\n", exec_dir);
        fprintf(fp, "SBBSNNUM=%d\n", cfg.node_num);
		fprintf(fp, "PCBNODE=%d\n", cfg.node_num);
		fprintf(fp, "PCBDRIVE=%.2s\n", node_dir);
		fprintf(fp, "PCBDIR=%s\n", node_dir + 2);
		/* date/time env vars */
		fprintf(fp, "DAY=%02u\n", tm.tm_mday);
		fprintf(fp, "WEEKDAY=%s\n",wday[tm.tm_wday]);
		fprintf(fp, "MONTHNAME=%s\n",mon[tm.tm_mon]);
		fprintf(fp, "MONTH=%02u\n",tm.tm_mon+1);
		fprintf(fp, "YEAR=%u\n",1900+tm.tm_year);
        fclose(fp);

        SAFEPRINTF2(fullcmdline, "%sDOSXTRN.EXE %s", cfg.exec_dir, path);

		if(!(mode&EX_OFFLINE)) {
			i=SBBSEXEC_MODE_FOSSIL;
			if(mode&EX_STDIN)
           		i|=SBBSEXEC_MODE_DOS_IN;
			if(mode&EX_STDOUT)
        		i|=SBBSEXEC_MODE_DOS_OUT;
			sprintf(str," NT %u %u"
				,cfg.node_num,i);
			strcat(fullcmdline,str);

			sprintf(str,"sbbsexec_hungup%d",cfg.node_num);
			if((hungup_event=CreateEvent(
				 NULL	// pointer to security attributes
				,TRUE	// flag for manual-reset event
				,FALSE  // flag for initial state
				,str	// pointer to event-object name
				))==NULL) {
				XTRN_CLEANUP;
				errormsg(WHERE, ERR_CREATE, str, 0);
				return(GetLastError());
			}

			sprintf(str,"sbbsexec_hangup%d",cfg.node_num);
			if((hangup_event=CreateEvent(
				 NULL	// pointer to security attributes
				,TRUE	// flag for manual-reset event
				,FALSE  // flag for initial state
				,str	// pointer to event-object name
				))==NULL) {
				XTRN_CLEANUP;
				errormsg(WHERE, ERR_CREATE, str, 0);
				return(GetLastError());
			}

			sprintf(str,"\\\\.\\mailslot\\sbbsexec\\rd%d"
				,cfg.node_num);
			rdslot=CreateMailslot(str
				,sizeof(buf)/2			// Maximum message size (0=unlimited)
				,0						// Read time-out
				,NULL);                 // Security
			if(rdslot==INVALID_HANDLE_VALUE) {
				XTRN_CLEANUP;
				errormsg(WHERE, ERR_CREATE, str, 0);
				return(GetLastError());
			}
		}
    }

	if(startup_dir!=NULL && startup_dir[0])
		p_startup_dir=startup_dir;
	else
		p_startup_dir=NULL;
    STARTUPINFO startup_info={0};
    startup_info.cb=sizeof(startup_info);
	if(mode&EX_OFFLINE)
		startup_info.lpTitle=NULL;
	else {
		SAFEPRINTF3(title,"%s running %s on node %d"
			,useron.number ? useron.alias : "Event"
			,realcmdline
			,cfg.node_num);
		startup_info.lpTitle=title;
	}
    if(startup->options&BBS_OPT_XTRN_MINIMIZED) {
    	startup_info.wShowWindow=SW_SHOWMINNOACTIVE;
        startup_info.dwFlags|=STARTF_USESHOWWINDOW;
    }
	if(use_pipes) {
		// Set up the security attributes struct.
		SECURITY_ATTRIBUTES sa;
		memset(&sa,0,sizeof(sa));
		sa.nLength= sizeof(SECURITY_ATTRIBUTES);
		sa.lpSecurityDescriptor = NULL;
		sa.bInheritHandle = TRUE;

		// Create the child output pipe (override default 4K buffer size)
		if(!CreatePipe(&rdoutpipe,&startup_info.hStdOutput,&sa,sizeof(buf))) {
			errormsg(WHERE,ERR_CREATE,"stdout pipe",0);
			strListFreeBlock(env_block);
			return(GetLastError());
		}
		startup_info.hStdError=startup_info.hStdOutput;

		// Create the child input pipe.
		if(!CreatePipe(&startup_info.hStdInput,&wrinpipe,&sa,sizeof(buf))) {
			errormsg(WHERE,ERR_CREATE,"stdin pipe",0);
			CloseHandle(rdoutpipe);
			strListFreeBlock(env_block);
			return(GetLastError());
		}

		DuplicateHandle(
			GetCurrentProcess(), rdoutpipe,
			GetCurrentProcess(), &rdslot, 0, FALSE, DUPLICATE_SAME_ACCESS);

		DuplicateHandle(
			GetCurrentProcess(), wrinpipe,
			GetCurrentProcess(), &wrslot, 0, FALSE, DUPLICATE_SAME_ACCESS);

		CloseHandle(rdoutpipe);
		CloseHandle(wrinpipe);

		startup_info.dwFlags|=STARTF_USESTDHANDLES|STARTF_USESHOWWINDOW;
    	startup_info.wShowWindow=SW_HIDE;
	}
	if(native && !(mode&EX_OFFLINE)) {

		if(!(mode&EX_STDIN)) {
			if(passthru_thread_running)
				passthru_socket_activate(true);
			else
				pthread_mutex_lock(&input_thread_mutex);
		}
	}

    success=CreateProcess(
		NULL,			// pointer to name of executable module
		fullcmdline,  	// pointer to command line string
		NULL,  			// process security attributes
		NULL,   		// thread security attributes
		native && !(mode&EX_OFFLINE),	 			// handle inheritance flag
		CREATE_NEW_CONSOLE/*|CREATE_SEPARATE_WOW_VDM*/, // creation flags
        env_block, 		// pointer to new environment block
		p_startup_dir,	// pointer to current directory name
		&startup_info,  // pointer to STARTUPINFO
		&process_info  	// pointer to PROCESS_INFORMATION
		);

	strListFreeBlock(env_block);

	if(!success) {
		XTRN_CLEANUP;
		if(!(mode&EX_STDIN)) {
			if(passthru_thread_running)
				passthru_socket_activate(false);
			else
				pthread_mutex_unlock(&input_thread_mutex);
		}
		SetLastError(last_error);	/* Restore LastError */
        errormsg(WHERE, ERR_EXEC, realcmdline, mode);
		SetLastError(last_error);	/* Restore LastError */
        return(GetLastError());
    }

#if 0
	char dbgstr[256];
	sprintf(dbgstr,"Node %d created: hProcess %X hThread %X processID %X threadID %X\n"
		,cfg.node_num
		,process_info.hProcess
		,process_info.hThread
		,process_info.dwProcessId
		,process_info.dwThreadId);
	OutputDebugString(dbgstr);
#endif

	CloseHandle(process_info.hThread);

	/* Disable Ctrl-C checking */
	if(!(mode&EX_OFFLINE))
		rio_abortable=false;

    // Executing app in foreground?, monitor
    retval=STILL_ACTIVE;
    while(!(mode&EX_BG)) {
		if(mode&EX_CHKTIME)
			gettimeleft();
        if(!online && !(mode&EX_OFFLINE)) { // Tell VXD/VDD and external that user hung-up
        	if(was_online) {
				logline(LOG_NOTICE,"X!","hung-up in external program");
            	hungup=time(NULL);
				if(!native) {
					SetEvent(hungup_event);
				}
	            was_online=false;
            }
            if(hungup && time(NULL)-hungup>5 && !processTerminated) {
				lprintf(LOG_INFO,"Terminating process from line %d", __LINE__);
				processTerminated=TerminateProcess(process_info.hProcess, 2112);
			}
        }
		if((native && !use_pipes) || mode&EX_OFFLINE) {
			/* Monitor for process termination only */
			if(WaitForSingleObject(process_info.hProcess,1000)==WAIT_OBJECT_0)
				break;
		} else {

			/* Write to VDD */

			wr=RingBufPeek(&inbuf,buf,sizeof(buf));
			if(wr) {
				if(!use_pipes && wrslot==INVALID_HANDLE_VALUE) {
					sprintf(str,"\\\\.\\mailslot\\sbbsexec\\wr%d"
						,cfg.node_num);
					wrslot=CreateFile(str
						,GENERIC_WRITE
						,FILE_SHARE_READ
						,NULL
						,OPEN_EXISTING
						,FILE_ATTRIBUTE_NORMAL
						,(HANDLE) NULL);
					if(wrslot==INVALID_HANDLE_VALUE)
						lprintf(LOG_DEBUG,"!ERROR %u (%s) opening %s", GetLastError(), strerror(errno), str);
					else
						lprintf(LOG_DEBUG,"CreateFile(%s)=0x%x", str, wrslot);
				}

				/* CR expansion */
				if(use_pipes)
					bp=cr_expand(buf,wr,output_buf,wr);
				else
					bp=buf;

				len=0;
				if(wrslot==INVALID_HANDLE_VALUE)
					lprintf(LOG_WARNING,"VDD Open failed (not loaded yet?)");
				else if(!WriteFile(wrslot,bp,wr,&len,NULL)) {
					lprintf(LOG_ERR,"!VDD WriteFile(0x%x, %u) FAILURE (Error=%u)", wrslot, wr, GetLastError());
					if(GetMailslotInfo(wrslot,&wr,NULL,NULL,NULL))
						lprintf(LOG_DEBUG,"!VDD MailSlot max_msg_size=%u", wr);
					else
						lprintf(LOG_DEBUG,"!GetMailslotInfo(0x%x)=%u", wrslot, GetLastError());
				} else {
					if(len!=wr)
						lprintf(LOG_WARNING,"VDD short write (%u instead of %u)", len,wr);
					RingBufRead(&inbuf, NULL, len);
					if(use_pipes && !(mode&EX_NOECHO)) {
						/* echo */
						RingBufWrite(&outbuf, bp, len);
					}
				}
				wr=len;
			}

			/* Read from VDD */

			rd=0;
			len=sizeof(buf);
			avail=RingBufFree(&outbuf)/2;	// leave room for wwiv/telnet expansion
#if 0
			if(avail==0)
				lprintf("Node %d !output buffer full (%u bytes)"
					,cfg.node_num,RingBufFull(&outbuf));
#endif
			if(len>avail)
            	len=avail;

			while(rd<len) {
				unsigned long waiting=0;

				if(use_pipes)
					PeekNamedPipe(
						rdslot,             // handle to pipe to copy from
						NULL,               // pointer to data buffer
						0,					// size, in bytes, of data buffer
						NULL,				// pointer to number of bytes read
						&waiting,			// pointer to total number of bytes available
						NULL				// pointer to unread bytes in this message
						);
				else
					GetMailslotInfo(
						rdslot,				// mailslot handle
 						NULL,				// address of maximum message size
						NULL,				// address of size of next message
						&waiting,			// address of number of messages
 						NULL				// address of read time-out
						);
				if(!waiting)
					break;
				if(ReadFile(rdslot,buf+rd,len-rd,&msglen,NULL)==FALSE || msglen<1)
					break;
				rd+=msglen;
			}

			if(rd) {
				if(mode&EX_WWIV) {
                	bp=wwiv_expand(buf, rd, wwiv_buf, rd, useron.misc, wwiv_flag);
					if(rd>sizeof(wwiv_buf))
						lprintf(LOG_ERR,"WWIV_BUF OVERRUN");
				} else if(telnet_mode&TELNET_MODE_OFF) {
					bp=buf;
				} else {
                	rd = telnet_expand(buf, rd, telnet_buf, sizeof(telnet_buf), /* expand_cr: */false, &bp);
				}
				if(rd>RingBufFree(&outbuf)) {
					lprintf(LOG_ERR,"output buffer overflow");
					rd=RingBufFree(&outbuf);
				}
				if(mode&EX_BIN)
					RingBufWrite(&outbuf, bp, rd);
				else
					rputs((char*)bp, rd);
			}
#if defined(_DEBUG) && 0
			if(rd>1) {
				sprintf(str,"Node %d read %5d bytes from xtrn", cfg.node_num, rd);
				OutputDebugString(str);
			}
#endif
            if((!rd && !wr) || hungup) {

				loop_since_io++;	/* number of loop iterations with no I/O */

				/* only check process termination after 300 milliseconds of no I/O */
				/* to allow for last minute reception of output from DOS programs */
				if(loop_since_io>=3) {

					if(online && hangup_event!=NULL
						&& WaitForSingleObject(hangup_event,0)==WAIT_OBJECT_0) {
						lprintf(LOG_NOTICE,"Node %d External program requested hangup (dropped DTR)"
							,cfg.node_num);
						hangup();
					}

					if(WaitForSingleObject(process_info.hProcess,0)==WAIT_OBJECT_0)
						break;	/* Process Terminated */
				}

				/* only check node for interrupt flag every 3 seconds of no I/O */
				if((loop_since_io%30)==0) {
					// Check if the node has been interrupted
					getnodedat(cfg.node_num,&thisnode,0);
					if(thisnode.misc&NODE_INTR)
						break;
				}

				/* only send telnet GA every 30 seconds of no I/O */
				if((loop_since_io%300)==0) {
#if defined(_DEBUG)
					sprintf(str,"Node %d xtrn idle\n",cfg.node_num);
					OutputDebugString(str);
#endif
					// Let's make sure the socket is up
					// Sending will trigger a socket d/c detection
					if(!(startup->options&BBS_OPT_NO_TELNET_GA))
						send_telnet_cmd(TELNET_GA,0);
				}
				sem_trywait_block(&inbuf.sem,100);
            } else
				loop_since_io=0;
        }
	}

    if(!(mode&EX_BG)) {			/* !background execution */

        if(GetExitCodeProcess(process_info.hProcess, &retval)==FALSE)
            errormsg(WHERE, ERR_CHK, "ExitCodeProcess",(DWORD)process_info.hProcess);

		if(retval==STILL_ACTIVE) {
			lprintf(LOG_INFO,"Node %d Terminating process from line %d",cfg.node_num,__LINE__);
			TerminateProcess(process_info.hProcess, GetLastError());
		}

	 	// Get return value
		if(!native) {
    		sprintf(str,"%sDOSXTRN.RET", cfg.node_dir);
			FILE* fp=fopen(str,"r");
			if(fp!=NULL) {
				if(fscanf(fp,"%d",&retval) != 1) {
					lprintf(LOG_ERR, "Node %d Error reading return value from %s", cfg.node_num, str);
					retval = -1;
				}
				fclose(fp);
			}
		}
	}

	XTRN_CLEANUP;
	CloseHandle(process_info.hProcess);

	if(!(mode&EX_OFFLINE)) {	/* !off-line execution */

		if(native) {
			if(!(mode&EX_STDIN)) {
				if(passthru_thread_running)
					passthru_socket_activate(false);
				else
					pthread_mutex_unlock(&input_thread_mutex);
			}
		}

		curatr=~0;			// Can't guarantee current attributes
		attr(LIGHTGRAY);	// Force to "normal"

		rio_abortable=rio_abortable_save;	// Restore abortable state

		/* Got back to Text/NVT mode */
		request_telnet_opt(TELNET_DONT,TELNET_BINARY_TX);
	}

//	lprintf("%s returned %d",realcmdline, retval);

	errorlevel = retval; // Baja or JS retrievable error value

	return(retval);
}

#else	/* !WIN32 */

/*****************************************************************************/
// Expands Unix LF to CRLF
/*****************************************************************************/
BYTE* lf_expand(BYTE* inbuf, ulong inlen, BYTE* outbuf, ulong& newlen)
{
	ulong	i,j;

	for(i=j=0;i<inlen;i++) {
		if(inbuf[i]=='\n' && (!i || inbuf[i-1]!='\r'))
			outbuf[j++]='\r';
		outbuf[j++]=inbuf[i];
	}
	newlen=j;
    return(outbuf);
}

#define MAX_ARGS 1000

#ifdef NEEDS_SETENV
static int setenv(const char *name, const char *value, int overwrite)
{
	char *envstr;
	char *oldenv;
	if(overwrite || getenv(name)==NULL) {
		envstr=(char *)malloc(strlen(name)+strlen(value)+2);
		if(envstr==NULL) {
			errno=ENOMEM;
			return(-1);
		}
		/* Note, on some platforms, this can be free()d... */
		sprintf(envstr,"%s=%s",name,value);
		putenv(envstr);
	}
	return(0);
}
#endif

#ifdef NEEDS_CFMAKERAW
void
cfmakeraw(struct termios *t)
{
	t->c_iflag &= ~(IMAXBEL|IGNBRK|BRKINT|PARMRK|ISTRIP|INLCR|IGNCR|ICRNL|IXON);
	t->c_oflag &= ~OPOST;
	t->c_lflag &= ~(ECHO|ECHONL|ICANON|ISIG|IEXTEN);
	t->c_cflag &= ~(CSIZE|PARENB);
	t->c_cflag |= CS8;
}
#endif

#ifdef NEEDS_FORKPTY
static int login_tty(int fd)
{
	(void) setsid();
	if (!isatty(fd))
		return (-1);
	(void) dup2(fd, 0);
	(void) dup2(fd, 1);
	(void) dup2(fd, 2);
	if (fd > 2)
		(void) close(fd);
	return (0);
}

#ifdef NEEDS_DAEMON
/****************************************************************************/
/* Daemonizes the process                                                   */
/****************************************************************************/
int
daemon(int nochdir, int noclose)
{
    int fd;

    switch (fork()) {
    case -1:
        return (-1);
    case 0:
        break;
    default:
        _exit(0);
    }

    if (setsid() == -1)
        return (-1);

    if (!nochdir)
        (void)chdir("/");

    if (!noclose && (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
        (void)dup2(fd, STDIN_FILENO);
        (void)dup2(fd, STDOUT_FILENO);
        (void)dup2(fd, STDERR_FILENO);
        if (fd > 2)
            (void)close(fd);
    }
    return (0);
}
#endif

static int openpty(int *amaster, int *aslave, char *name, struct termios *termp, winsize *winp)
{
	char line[] = "/dev/ptyXX";
	const char *cp1, *cp2;
	int master, slave, ttygid;
	struct group *gr;

	if ((gr = getgrnam("tty")) != NULL)
		ttygid = gr->gr_gid;
	else
		ttygid = -1;

	for (cp1 = "pqrsPQRS"; *cp1; cp1++) {
		line[8] = *cp1;
		for (cp2 = "0123456789abcdefghijklmnopqrstuv"; *cp2; cp2++) {
			line[5] = 'p';
			line[9] = *cp2;
			if ((master = open(line, O_RDWR, 0)) == -1) {
				if (errno == ENOENT)
					break; /* try the next pty group */
			} else {
				line[5] = 't';
				(void) chown(line, getuid(), ttygid);
				(void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP);
				/* Hrm... SunOS doesn't seem to have revoke