dm/dm.c

   1 /*      $NetBSD: dm.c,v 1.4 1995/03/21 15:09:05 cgd Exp $       */
   2
   3 /*
   4  * Copyright (c) 1987, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #ifndef lint
  37 static char copyright[] =
  38 "@(#) Copyright (c) 1987, 1993\n\
  39         The Regents of the University of California.  All rights reserved.\n";
  40 #endif /* not lint */
  41
  42 #ifndef lint
  43 #if 0
  44 static char sccsid[] = "@(#)dm.c        8.1 (Berkeley) 5/31/93";
  45 #else
  46 static char rcsid[] = "$NetBSD: dm.c,v 1.4 1995/03/21 15:09:05 cgd Exp $";
  47 #endif
  48 #endif /* not lint */
  49
  50 #include <sys/param.h>
  51 #include <sys/file.h>
  52 #include <sys/time.h>
  53 #include <sys/resource.h>
  54
  55 #include <ctype.h>
  56 #include <nlist.h>
  57 #include <pwd.h>
  58 #include <stdio.h>
  59 #include <string.h>
  60 #include <time.h>
  61 #include <unistd.h>
  62 #include <utmp.h>
  63
  64 #include "pathnames.h"
  65
  66 extern int errno;
  67 static time_t   now;                    /* current time value */
  68 static int      priority = 0;           /* priority game runs at */
  69 static char     *game,                  /* requested game */
  70                 *gametty;               /* from tty? */
  71
  72 int
  73 main(argc, argv)
  74         int argc;
  75         char *argv[];
  76 {
  77         char *cp;
  78
  79         nogamefile();
  80         game = (cp = rindex(*argv, '/')) ? ++cp : *argv;
  81
  82         if (!strcmp(game, "dm"))
  83                 exit(0);
  84
  85         gametty = ttyname(0);
  86         (void)time(&now);
  87         read_config();
  88 #ifdef LOG
  89         logfile();
  90 #endif
  91         play(argv);
  92         /*NOTREACHED*/
  93 }
  94
  95 /*
  96  * play --
  97  *      play the game
  98  */
  99 play(args)
 100         char **args;
 101 {
 102         char pbuf[MAXPATHLEN];
 103
 104         (void)strcpy(pbuf, _PATH_HIDE);
 105         (void)strcpy(pbuf + sizeof(_PATH_HIDE) - 1, game);
 106         if (priority > 0)       /* < 0 requires root */
 107                 (void)setpriority(PRIO_PROCESS, 0, priority);
 108         setgid(getgid());       /* we run setgid kmem; lose it */
 109         execv(pbuf, args);
 110         (void)fprintf(stderr, "dm: %s: %s\n", pbuf, strerror(errno));
 111         exit(1);
 112 }
 113
 114 /*
 115  * read_config --
 116  *      read through config file, looking for key words.
 117  */
 118 read_config()
 119 {
 120         FILE *cfp;
 121         char lbuf[BUFSIZ], f1[40], f2[40], f3[40], f4[40], f5[40];
 122
 123         if (!(cfp = fopen(_PATH_CONFIG, "r")))
 124                 return;
 125         while (fgets(lbuf, sizeof(lbuf), cfp))
 126                 switch(*lbuf) {
 127                 case 'b':               /* badtty */
 128                         if (sscanf(lbuf, "%s%s", f1, f2) != 2 ||
 129                             strcasecmp(f1, "badtty"))
 130                                 break;
 131                         c_tty(f2);
 132                         break;
 133                 case 'g':               /* game */
 134                         if (sscanf(lbuf, "%s%s%s%s%s",
 135                             f1, f2, f3, f4, f5) != 5 || strcasecmp(f1, "game"))
 136                                 break;
 137                         c_game(f2, f3, f4, f5);
 138                         break;
 139                 case 't':               /* time */
 140                         if (sscanf(lbuf, "%s%s%s%s", f1, f2, f3, f4) != 4 ||
 141                             strcasecmp(f1, "time"))
 142                                 break;
 143                         c_day(f2, f3, f4);
 144                 }
 145         (void)fclose(cfp);
 146 }
 147
 148 /*
 149  * c_day --
 150  *      if day is today, see if okay to play
 151  */
 152 c_day(s_day, s_start, s_stop)
 153         char *s_day, *s_start, *s_stop;
 154 {
 155         static char *days[] = {
 156                 "sunday", "monday", "tuesday", "wednesday",
 157                 "thursday", "friday", "saturday",
 158         };
 159         static struct tm *ct;
 160         int start, stop;
 161
 162         if (!ct)
 163                 ct = localtime(&now);
 164         if (strcasecmp(s_day, days[ct->tm_wday]))
 165                 return;
 166         if (!isdigit(*s_start) || !isdigit(*s_stop))
 167                 return;
 168         start = atoi(s_start);
 169         stop = atoi(s_stop);
 170         if (ct->tm_hour >= start && ct->tm_hour < stop) {
 171                 fputs("dm: Sorry, games are not available from ", stderr);
 172                 hour(start);
 173                 fputs(" to ", stderr);
 174                 hour(stop);
 175                 fputs(" today.\n", stderr);
 176                 exit(0);
 177         }
 178 }
 179
 180 /*
 181  * c_tty --
 182  *      decide if this tty can be used for games.
 183  */
 184 c_tty(tty)
 185         char *tty;
 186 {
 187         static int first = 1;
 188         static char *p_tty;
 189
 190         if (first) {
 191                 p_tty = rindex(gametty, '/');
 192                 first = 0;
 193         }
 194
 195         if (!strcmp(gametty, tty) || p_tty && !strcmp(p_tty, tty)) {
 196                 fprintf(stderr, "dm: Sorry, you may not play games on %s.\n", gametty);
 197                 exit(0);
 198         }
 199 }
 200
 201 /*
 202  * c_game --
 203  *      see if game can be played now.
 204  */
 205 c_game(s_game, s_load, s_users, s_priority)
 206         char *s_game, *s_load, *s_users, *s_priority;
 207 {
 208         static int found;
 209         double load();
 210
 211         if (found)
 212                 return;
 213         if (strcmp(game, s_game) && strcasecmp("default", s_game))
 214                 return;
 215         ++found;
 216         if (isdigit(*s_load) && atoi(s_load) < load()) {
 217                 fputs("dm: Sorry, the load average is too high right now.\n", stderr);
 218                 exit(0);
 219         }
 220         if (isdigit(*s_users) && atoi(s_users) <= users()) {
 221                 fputs("dm: Sorry, there are too many users logged on right now.\n", stderr);
 222                 exit(0);
 223         }
 224         if (isdigit(*s_priority))
 225                 priority = atoi(s_priority);
 226 }
 227
 228 /*
 229  * load --
 230  *      return 15 minute load average
 231  */
 232 double
 233 load()
 234 {
 235         double avenrun[3];
 236
 237         if (getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0])) < 0) {
 238                 fputs("dm: getloadavg() failed.\n", stderr);
 239                 exit(1);
 240         }
 241         return(avenrun[2]);
 242 }
 243
 244 /*
 245  * users --
 246  *      return current number of users
 247  *      todo: check idle time; if idle more than X minutes, don't
 248  *      count them.
 249  */
 250 users()
 251 {
 252
 253         register int nusers, utmp;
 254         struct utmp buf;
 255
 256         if ((utmp = open(_PATH_UTMP, O_RDONLY, 0)) < 0) {
 257                 (void)fprintf(stderr, "dm: %s: %s\n",
 258                     _PATH_UTMP, strerror(errno));
 259                 exit(1);
 260         }
 261         for (nusers = 0; read(utmp, (char *)&buf, sizeof(struct utmp)) > 0;)
 262                 if (buf.ut_name[0] != '\0')
 263                         ++nusers;
 264         return(nusers);
 265 }
 266
 267 nogamefile()
 268 {
 269         register int fd, n;
 270         char buf[BUFSIZ];
 271
 272         if ((fd = open(_PATH_NOGAMES, O_RDONLY, 0)) >= 0) {
 273 #define MESG    "Sorry, no games right now.\n\n"
 274                 (void)write(2, MESG, sizeof(MESG) - 1);
 275                 while ((n = read(fd, buf, sizeof(buf))) > 0)
 276                         (void)write(2, buf, n);
 277                 exit(1);
 278         }
 279 }
 280
 281 /*
 282  * hour --
 283  *      print out the hour in human form
 284  */
 285 hour(h)
 286         int h;
 287 {
 288         switch(h) {
 289         case 0:
 290                 fputs("midnight", stderr);
 291                 break;
 292         case 12:
 293                 fputs("noon", stderr);
 294                 break;
 295         default:
 296                 if (h > 12)
 297                         fprintf(stderr, "%dpm", h - 12);
 298                 else
 299                         fprintf(stderr, "%dam", h);
 300         }
 301 }
 302
 303 #ifdef LOG
 304 /*
 305  * logfile --
 306  *      log play of game
 307  */
 308 logfile()
 309 {
 310         struct passwd *pw;
 311         FILE *lp;
 312         uid_t uid;
 313         int lock_cnt;
 314
 315         if (lp = fopen(_PATH_LOG, "a")) {
 316                 for (lock_cnt = 0;; ++lock_cnt) {
 317                         if (!flock(fileno(lp), LOCK_EX))
 318                                 break;
 319                         if (lock_cnt == 4) {
 320                                 perror("dm: log lock");
 321                                 (void)fclose(lp);
 322                                 return;
 323                         }
 324                         sleep((u_int)1);
 325                 }
 326                 if (pw = getpwuid(uid = getuid()))
 327                         fputs(pw->pw_name, lp);
 328                 else
 329                         fprintf(lp, "%u", uid);
 330                 fprintf(lp, "\t%s\t%s\t%s", game, gametty, ctime(&now));
 331                 (void)fclose(lp);
 332                 (void)flock(fileno(lp), LOCK_UN);
 333         }
 334 }
 335 #endif /* LOG */