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Path: utzoo!mnetor!seismo!rutgers!im4u!swrinde!petro!tness1!mechjgh
From: mechjgh@tness1.UUCP (8753)
Newsgroups: comp.unix.wizards
Subject: Re: watch-dog program
Message-ID: <191@tness1.UUCP>
Date: Mon, 11-May-87 22:22:32 EDT
Article-I.D.: tness1.191
Posted: Mon May 11 22:22:32 1987
Date-Received: Sat, 16-May-87 01:12:53 EDT
References: <7305@brl-adm.ARPA>
Organization: Southwestern Bell, Texas
Lines: 190
Summary: source to hogs.c

In article <7305@brl-adm.ARPA>, rachiele@nadc.arpa writes:
> 
> I am in need of an automatic logout program for unix sys V (2.2) running on
> a VAX785.  By this I mean, some software which will logout inactive
> users after some set amount of idle time.  Can anyone help me out?
>         Thanks.
>              Jim
>            rachiele@nadc.arpa


Here is the source for hogs.c which I wrote specifically for our VAX 785
with S5R2. It ignores the root login, handles users that are
on sxt pseudo ports, and has an anti-logoff file for special users.

The code isn't state-of-the-art, but neither am I ! It's your's
to try.

Greg Hackney

-----<cut here>-----
/* hogs.c  Greg Hackney 8-16-86  ihnp4!tness1!mechjgh
 *         Southwestern Bell Telephone Co. (713+521-8753)
 *         3100 Main, Room 1009
 *         Houston, Texas 77001
 *
 * to compile: make hogs
 *
 * run as root in cron to kill idle users
 * as often as desired (tested on AT&T S5R2 only)
 *
 * Usage:  hogs -t time-in-minutes [ -f Anti_Kill_File ]    
 * i.e.: hogs -t 30 -f /etc/antikill (to kill users idle for 30 minutes or more)
 *
 * Typical crontab entry:
 *      0,15,30,45 * * * * /etc/hogs -t 30 -f /etc/antikill
 *
 * optional Anti_Kill_File may contain a vertical list of
 * lognames to be made exempt from the kill
 *
 *
 * This is considered public domain software and not for resale
 */
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <utmp.h>
#include <string.h>
#include <termio.h>
#include <fcntl.h>
#define USAGE "Usage: hogs -t time-in-mins [ -f Anti_Kill_File ]"
extern char *optarg;
FILE	*anti;
int	DEV,
	DEBUG;
#define YES 1
#define NO 0
char *malloc();
time_t	ktime;  /*minutes of grace allowed before kill*/
long	now;    /*number of clock ticks since 1-1-70 AD (after dec)*/
struct utmp *getutent();
struct utmp *READ;
struct stat statbuf;
struct termio term;
char	*string;
char	antifile[40],  /*pathname to antikill exemption file*/
	Device[20];    /*pathname to users tty*/
int aflag;
main(argc,argv)
int argc;
char *argv[];
{
	int c;
	DEBUG=NO;
	if(argc < 2){
		fprintf(stderr,"%s\n",USAGE);
		exit(1);
		}
	while((c=getopt(argc,argv,"dt:f:"))!=EOF){
		switch(c){
		case 'f':
			aflag=YES;
			strcpy(antifile,optarg);
			break;
		case 't':
			/*get cutoff time*/
			ktime=atol(optarg);
			break;
		case 'd':
			DEBUG = YES;
			break;
		default:
			fprintf(stderr,"%s\n",USAGE);
			exit(1);
			break;
			}
		}
	if((string=malloc(512))==NULL){
		fprintf(stderr,"Memory allocation error\n");
		exit(1);
		}
	if(aflag==YES){  /*if antikill file requested with -f option*/
		if((anti=fopen(antifile,"r"))==NULL)
			aflag=NO;
		}

	/*get current time*/
	now=time((long *)0);

	while((READ = getutent() )!=NULL){
		   if(READ->ut_type != USER_PROCESS) /*look for user process*/
			continue;

		/*get idle time for the device*/
		strcpy(Device,"/dev/");
		strcat(Device,READ->ut_line);
		stat(Device,&statbuf);

		if(((now - statbuf.st_mtime)/60) < ktime)  /*skip active users*/
			continue;
		if(aflag == YES)  /*if antikill file is open*/
			if(nokill() == YES)
				continue;  /*an exempt user*/

		/*don't ever kill console*/
		if((strcmp("root",READ->ut_user))==0)
			continue;

		/* sxt devices */
		if((strncmp("sxt\0",READ->ut_line,3))==0){
			if((kill(READ->ut_pid,1)) != -1)
			  if((kill(READ->ut_pid,0)) != -1)
				if((kill(READ->ut_pid,9)) != -1)
					;
			continue;
			}

		/*hang up modem*/
		if((DEV=open(Device,O_RDWR))==-1)
			continue;
		if((ioctl(DEV,TCGETA,&term))==-1){
			close(DEV);
			continue;
			}
		if(DEBUG == NO){  /*initiate hangup*/
			term.c_cflag &= ~CBAUD;
			term.c_cflag |= B0 & CBAUD;
			}
		if((ioctl(DEV,TCSETAW,&term))==-1){
			close(DEV);
			continue;
			}
		close(DEV);
		KILLALL();  /*obliterate the hog's processes !!!*/
		}
	fclose(anti); /*be neat and tidy*/
	exit(0);
}
nokill() /*if user is exempt, return YES, else NO */
{
	rewind(anti);
	while((fgets(string,512,anti))!=NULL){
		string=strtok(string,"\n");
		if((strcmp(string,READ->ut_user))==0)
			return(YES);
		}
	return(NO);
}

KILLALL() /* kill all processes associated with a given tty*/
{
	FILE *ps;
	char buf[512];

	sprintf(buf,"/bin/nohup /bin/ps -t %s\0",READ->ut_line);

	if((ps=popen(buf,"r"))==NULL)
		return(1);
	fgets(buf,512,ps);
	while((fgets(buf,512,ps))!=NULL){
		string=strtok(buf," ");
		if(DEBUG == YES)
			printf("kill process %s\n",string);
		else
		kill(atoi(string),1);
		if((kill(READ->ut_pid,0))==0)
			kill(READ->ut_pid,9);
		}
	pclose(ps);
}
----<cut here>-----