;<TITLE>AUTOLOGIN.MAR og in a specified username to a specified terminal </TITLE>
;From: deleyd@netcom.com
;Subj: Re: UIC of detached proc. using LOGINOUT? (Ive RTFM and am puzzled)
;Date: Wed, 5 Oct 1994 04:01:38 GMT
;
;> However, the real problem is that if I detach a process using LOGINOUT,
;> despite specifying a different UIC, the UIC of the detached process is
;> still the UIC of process creating the detached process.
;
;You'll need DETACH privilege to specify a different UIC.  As for the username,
;we solve the problem by temporarily changing the username to what you
;want the detached process to be, creating the detached process, and
;then resetting the username back to our own username.  The sample
;MACRO32 code below does this.  Maybe it will give some ideas.  Maybe
;someone else has a better example that's not in MACRO32.
;
;Another idea is to create a batch job which starts the detached process,
;and then use $ SUBMIT/NAME=username 
;to submit the batch job.  This requires CMKRNL priv.  There's probably
;some other good ideas someone else will come up with.
;
;-David Deley
;deleyd@netcom.com
;
;Below is a sample program in MACRO:
;   This code requires CMKRNL privilege.  It has been tested on VAX/VMS.
;I don't know how to do this yet on an AXP/OpenVMS system.
;
;[DAVID.AUTOLOGIN]                       (VAX/VMS. Concept has not been tested
;                                                  on AXP/OpenVMS systems)
;
;This example MACRO program will log in a specified username to a
;specified terminal as if someone had entered their username and password
;interactively at the terminal.  The terminal will "jump to life" by
;itself.
;
;This example program as set up here logs in username VISIT to terminal
;TXF4: with process name "sys_immoVAULT"
;
;Change  NEW_USRNAM: to the username you want to login
;Change  TERMINAL:   to the terminal you want username to log into
;Change  PROC_NAME:  to the process name you want username to use
;
;(Leave PRIVS: as is.  Privileges and all other process details are set
;                      by LOGINOUT.EXE according to username listing in
;                      SYSUAF.DAT as set by AUTHORIZE.)
;
;
;This program executes some code in kernel mode.  As you know errors in
;kernel mode can crash the system, so test it gingerly keeping that in
;mind.  It does establish a crash handler so if an error should occur it
;should terminate the image with a stack dump rather than crash the whole
;system.
;
;The key to this program is the use of the flag PRC$M_NOPASSWORD in the
;call to $CREPRC.  See the VAX/VMS System Service Reference Manual
;documentation of the $CREPRC system service for further information. 
;This program has been tested on VMS 4.4 and VMS 5.3 .
;
;David W. Deley
;
;$!Compile and link AUTOLOGIN program
;$ MACRO AUTOLOGIN
;$ LINK AUTOLOGIN
;$ EXIT
;
         .TITLE AUTOLOGIN
	.LIBRARY	/SYS$LIBRARY:LIB/
	.LINK		'SYS$SYSTEM:SYS.STB'	/SELECTIVE_SEARCH

        .PSECT  DATA, WRT, NOEXE, RD

	$CHFDEF
	$JIBDEF
	$PCBDEF
	$PRCDEF

PRIVS:		.LONG	^xFFFFFFFF
		.LONG	^xFFFFFFFF
IMGNAM:		.ASCID  /SYS$SYSTEM:LOGINOUT.EXE/  ;Creprc runs LOGINOUT
;TERMINAL:	.ASCID  /TXF4:/
TERMINAL:	.ASCID  /LTA28:/
PROC_NAME:	.ASCID  /sys_immoVAULT/
OLD_USRNAM:	.BLKB	12
NEW_USRNAM:	.ASCII	/VISIT/
NEW_USRNAMLEN=.-NEW_USRNAM
ERRMSG:		.ASCIZ	/AUTOLOGIN KERNEL MODE ERROR/
;------------------------------------------------------------------------------

        .PSECT  CODE, NOWRT, EXE
        .ENTRY AUTOLOGIN, ^M<>

	$CMKRNL_S routin=SAVE_USERNAME	;Save our username
	BLBC R0,EXIT

	$CMKRNL_S routin=SET_USERNAME	;Set new username
	BLBC R0,EXIT

        $CREPRC_S -                     ;AUTOLOGIN PROCESS
		image=imgnam, -         ;run LOGINOUT.EXE
		input=terminal, -       ;assign SYS$INPUT
		output=terminal, -      ;assign SYS$OUTPUT
		error=terminal, -	;assign SYS$ERROR
		prvadr=privs, -		;Privs get set by loginout according to UAF
		prcnam=proc_name, -	;Set process name
		baspri=#4, -		;Set base priority
		STSFLG=#<PRC$M_INTER!PRC$M_DETACH!PRC$M_NOPASSWORD>
	BLBC R0,EXIT

	$CMKRNL_S routin=RESTORE_USERNAME
EXIT:	$EXIT_S R0

;------------------------------------------------------------------------------
	.ENTRY	SAVE_USERNAME, ^M<>	; R4 contains PCB address (supplied by CMKRNL)
	MOVAL	HANDLER,(FP)		; Establish crash handler
	MOVL	PCB$L_JIB(R4), R4
	MOVC3	#12, JIB$T_USERNAME(R4), OLD_USRNAM
	MOVL	#SS$_NORMAL,R0
	RET

	.ENTRY	SET_USERNAME, ^M<>	; R4 contains PCB address (supplied by CMKRNL)
	MOVAL	HANDLER,(FP)		; Establish crash handler
	MOVL	PCB$L_JIB(R4), R4
	MOVC5	#NEW_USRNAMLEN, NEW_USRNAM, #32, #12, JIB$T_USERNAME(R4)
	MOVL	#SS$_NORMAL,R0
	RET

	.ENTRY	RESTORE_USERNAME, ^M<>	; R4 contains PCB address (supplied by CMKRNL)
	MOVAL	HANDLER,(FP)		; Establish crash handler
	MOVL	PCB$L_JIB(R4), R4
	MOVC3	#12, OLD_USRNAM, JIB$T_USERNAME(R4)
	MOVL	#SS$_NORMAL,R0
	RET

	.ENTRY	HANDLER ^M<>
	MOVL	CHF$L_SIGARGLST(AP),R0	;Get address of signal args
	CMPL	#SS$_UNWIND,-		;Check for unwind operation
		CHF$L_SIG_NAME(R0)
	BEQL	1$			;Return if unwinding
	PUSHL	AP			;Address of sigargs
	PUSHAL	ERRMSG			;Address of ASCIZ string
	CALLS	#2,G^EXE$EXCMSG		;Dump error message
	CALLG	(AP),G^LIB$SIG_TO_RET	;Unwind stack and return to caller
1$:	RET

	.END	AUTOLOGIN