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/* Networked */
/* */
/* Written by: Glenn Machin 2931 */
/* Originated: Nov 12, 1990 */
/* Description: */
/* */
/* This program/routine exits/returns with a status 1 if */
/* the terminal associated with the current process is */
/* connected from a remote host, otherwise exits/returns */
/* with a value of 0. */
/* */
/* This program/routine makes some basic assumptions about */
/* utmp: */
/* *The login process, rcmd, or window application */
/* makes an entry into utmp for all currents */
/* users. */
/* *For entries in which the users have logged in */
/* locally. The line name is not a pseudo tty */
/* device. */
/* *For X window application in which */
/* the device is a pseudo tty device but the */
/* display is the local system, then the ut_host */
/* has the format system_name:0.0 or :0.0. */
/* All other entries will be assumed to be */
/* networked. */
/* */
/* Changes: 11/15/90 Check for file /etc/krb.secure. */
/* If it exists then perform network */
/* check, otherwise return 0. */
/****************************************************************/
/*
* Sandia National Laboratories also makes no representations about the
* suitability of the modifications, or additions to this software for
* any purpose. It is provided "as is" without express or implied warranty.
*/
#ifndef _TYPES_
#include <sys/types.h>
#ifndef _TYPES_
#define _TYPES_
#endif
#endif
#include <utmp.h>
#include <pwd.h>
#ifndef MAXHOSTNAME
#define MAXHOSTNAME 64
#endif
#if defined(HAVE_GETUTENT) && !defined(NO_UT_PID)
static int utfile;
#include <fcntl.h>
static void kadmin_setutent()
{
utfile = open("/etc/utmp",O_RDONLY);
}
static struct utmp * kadmin_getutline(utmpent)
struct utmp *utmpent;
{
static struct utmp tmputmpent;
int found = 0;
while ( read(utfile,&tmputmpent,sizeof(struct utmp)) > 0 ){
if ( strcmp(tmputmpent.ut_line,utmpent->ut_line) == 0){
#ifdef NO_UT_HOST
if ( ( 1) &&
#else
if ( (strcmp(tmputmpent.ut_host,"") == 0) &&
#endif
(strcmp(tmputmpent.ut_name,"") == 0)) continue;
found = 1;
break;
}
}
if (found)
return(&tmputmpent);
return((struct utmp *) 0);
}
static void kadmin_endutent()
{
close(utfile);
}
#else
#define kadmin_setutent setutent
#define kadmin_getutline getutline
#define kadmin_endutent endutent
#endif /* defined(HAVE_GETUTENT) && !defined(NO_UT_PID) */
int network_connected()
{
struct utmp utmpent;
struct utmp retutent, *tmpptr;
char *display_indx;
char currenthost[MAXHOSTNAME];
char *username,*tmpname;
/* Macro for pseudo_tty */
#define pseudo_tty(ut) \
((strncmp((ut).ut_line, "tty", 3) == 0 && ((ut).ut_line[3] == 'p' \
|| (ut).ut_line[3] == 'q' \
|| (ut).ut_line[3] == 'r' \
|| (ut).ut_line[3] == 's'))\
|| (strncmp((ut).ut_line, "pty", 3) == 0))
/* Check to see if getlogin returns proper name */
if ( (tmpname = (char *) getlogin()) == (char *) 0) return(1);
username = (char *) malloc(strlen(tmpname) + 1);
if ( username == (char *) 0) return(1);
strcpy(username,tmpname);
/* Obtain tty device for controlling tty of current process.*/
strncpy(utmpent.ut_line,ttyname(0) + strlen("/dev/"),
sizeof(utmpent.ut_line));
/* See if this device is currently listed in /etc/utmp under
calling user */
#ifndef NO_UT_TYPE
utmpent.ut_type = USER_PROCESS;
#define ut_name ut_user
#endif
kadmin_setutent();
while ( (tmpptr = (struct utmp *) kadmin_getutline(&utmpent))
!= ( struct utmp *) 0) {
/* If logged out name and host will be empty */
if ((strcmp(tmpptr->ut_name,"") == 0) &&
#ifdef NO_UT_HOST
( 1)) continue;
#else
(strcmp(tmpptr->ut_host,"") == 0)) continue;
#endif
else break;
}
if ( tmpptr == (struct utmp *) 0) {
kadmin_endutent();
return(1);
}
byte_copy((char *)tmpptr,(char *)&retutent,sizeof(struct utmp));
kadmin_endutent();
#ifdef DEBUG
#ifdef NO_UT_HOST
printf("User %s on line %s :\n",
retutent.ut_name,retutent.ut_line);
#else
printf("User %s on line %s connected from host :%s:\n",
retutent.ut_name,retutent.ut_line,retutent.ut_host);
#endif
#endif
if (strcmp(retutent.ut_name,username) != 0) {
return(1);
}
/* If this is not a pseudo tty then everything is OK */
if (! pseudo_tty(retutent)) return(0);
/* OK now the work begins there is an entry in utmp and
the device is a pseudo tty. */
/* Check if : is in hostname if so this is xwindow display */
if (gethostname(currenthost,sizeof(currenthost))) return(1);
#ifdef NO_UT_HOST
display_indx = (char *) 0;
#else
display_indx = (char *) strchr(retutent.ut_host,':');
#endif
if ( display_indx != (char *) 0) {
/*
We have X window application here. The host field should have
the form => local_system_name:0.0 or :0.0
if the window is being displayed on the local system.
*/
#ifdef NO_UT_HOST
return(1);
#else
if (strncmp(currenthost,retutent.ut_host,
(display_indx - retutent.ut_host)) != 0) return(1);
else return(0);
#endif
}
/* Host field is empty or is not X window entry. At this point
we can't trust that the pseudo tty is not connected to a
networked process so let's return 1.
*/
return(1);
}
byte_copy(str1,str2,len)
char *str1, *str2;
int len;
{
int i;
for (i=0;i < len; i++) *(str2 + i) = *(str1 + i);
return;
}
#ifdef NOTKERBEROS
main(argc,argv)
int argc;
char **argv;
{
if (network_connected()){
#ifdef DEBUG
printf("Networked\n");
#endif
exit(1);
}
else {
#ifdef DEBUG
printf("Not networked\n");
#endif
exit(0);
}
}
#else
int networked()
{
return(network_connected());
}
#endif
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