/*
  $Id: suex.c,v 1.2 1994/02/07 04:48:33 jaw Exp jaw $

  portions adapted from BSD su
  
*/

#include <stdio.h>
#include <syslog.h>
#include <sys/types.h>
#include <sys/time.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <grp.h>
#include <pwd.h>

#define SUPER_GROUP_NAME	"super-users"

char *mytty(void);

main(int argc, char **argv){
		
	int retcode;
	char string[260];
	int gids[NGROUPS_MAX],gidval;
	int i=0,uid, super_gid;
	struct passwd *pwd;
	struct group *grp;
	char *username;

	if ((pwd=getpwuid(uid = getuid()))==NULL){
		/* you have no entry in pw file */
		fprintf(stderr, "suex: who are you\n");
		exit(-1);
	}

	if ( (grp=getgrnam(SUPER_GROUP_NAME))==NULL){
		/* no super user group in group file */
		fprintf(stderr, "suex: super user group non-existant\n");
		exit(-1);
	}
	
	username = strdup(pwd->pw_name);
	openlog("suex:", LOG_PID|LOG_CONS, LOG_AUTH);	/* tell syslog all about it */


	gidval = getgroups(NGROUPS_MAX, gids); /* check if in group super-user */
	while ( (i<=gidval)&&(gids[i] != grp->gr_gid) ) i++;
	if ( gids[i] != grp->gr_gid ){
		syslog(LOG_AUTH|LOG_NOTICE, "suex failed for %s (%d) on %s", username, uid, mytty());
		fprintf(stderr,"You are not authorized to use this command\nSorry!\n");
		exit(-1);
	}

	setuid( geteuid() );	/* become root */
	setgid( getegid() ); 	/* become daemon group */
	syslog(LOG_AUTH|LOG_INFO, "suex succeded for %s (%d) on %s", username, uid, mytty());
	
	if (argc >1 ){
		execvp( argv[1], &argv[1] );
		fprintf(stderr, "%s: %s failed\r\n",argv[0],argv[1]);
		exit(-1);
	}else{
		printf("%s: exec. what?: ",argv[0]);
		fflush(stdout);
		retcode=system( gets(string) );
		if (retcode )
			fprintf(stderr,"%s: %s failed with error %d\r\n",argv[0],string,retcode);
		exit(retcode);
	}
}

char *mytty(void){
	char *p;
	return((p=ttyname(STDERR_FILENO))?p:"Unknown tty");
}