games/dm/dm.c

   1 /*
   2  * Copyright (c) 1987, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#) Copyright (c) 1987, 1993 The Regents of the University of California.  All rights reserved.
  34  * @(#)dm.c     8.1 (Berkeley) 5/31/93
  35  * $FreeBSD: src/games/dm/dm.c,v 1.8 1999/12/10 02:54:18 billf Exp $
  36  * $DragonFly: src/games/dm/dm.c,v 1.3 2003/11/12 14:53:52 eirikn Exp $
  37  */
  38
  39 #include <sys/param.h>
  40 #include <sys/file.h>
  41 #include <sys/time.h>
  42 #include <sys/resource.h>
  43
  44 #include <ctype.h>
  45 #include <errno.h>
  46 #include <nlist.h>
  47 #include <pwd.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <time.h>
  52 #include <unistd.h>
  53 #include <utmp.h>
  54
  55 #include "pathnames.h"
  56
  57 static time_t   now;                    /* current time value */
  58 static int      priority = 0;           /* priority game runs at */
  59 static char     *game,                  /* requested game */
  60                 *gametty;               /* from tty? */
  61
  62 void c_day (char *, char *, char *);
  63 void c_tty (char *);
  64 void c_game (char *, char *, char *, char *);
  65 void hour (int);
  66 double load (void);
  67 void nogamefile (void);
  68 void play (char **);
  69 void read_config (void);
  70 int users (void);
  71
  72 int
  73 main(argc, argv)
  74         int argc;
  75         char *argv[];
  76 {
  77         char *cp;
  78
  79         nogamefile();
  80         game = (cp = strrchr(*argv, '/')) ? ++cp : *argv;
  81
  82         if (!strcmp(game, "dm"))
  83                 exit(0);
  84
  85         gametty = ttyname(0);
  86         unsetenv("TZ");
  87         (void)time(&now);
  88         read_config();
  89 #ifdef LOG
  90         logfile();
  91 #endif
  92         play(argv);
  93         /*NOTREACHED*/
  94         exit(EXIT_FAILURE);
  95 }
  96
  97 /*
  98  * play --
  99  *      play the game
 100  */
 101 void
 102 play(args)
 103         char **args;
 104 {
 105         char pbuf[MAXPATHLEN];
 106
 107         if (sizeof(_PATH_HIDE) + strlen(game) > sizeof(pbuf)) {
 108                 (void)fprintf(stderr, "dm: %s/%s: %s\n", _PATH_HIDE, game,
 109                         strerror(ENAMETOOLONG));
 110                 exit(1);
 111         }
 112         (void)strcpy(pbuf, _PATH_HIDE);
 113         (void)strcpy(pbuf + sizeof(_PATH_HIDE) - 1, game);
 114         if (priority > 0)       /* < 0 requires root */
 115                 (void)setpriority(PRIO_PROCESS, 0, priority);
 116         execv(pbuf, args);
 117         (void)fprintf(stderr, "dm: %s: %s\n", pbuf, strerror(errno));
 118         exit(1);
 119 }
 120
 121 /*
 122  * read_config --
 123  *      read through config file, looking for key words.
 124  */
 125 void
 126 read_config()
 127 {
 128         FILE *cfp;
 129         char lbuf[BUFSIZ], f1[40], f2[40], f3[40], f4[40], f5[40];
 130
 131         if (!(cfp = fopen(_PATH_CONFIG, "r")))
 132                 return;
 133         while (fgets(lbuf, sizeof(lbuf), cfp))
 134                 switch(*lbuf) {
 135                 case 'b':               /* badtty */
 136                         if (sscanf(lbuf, "%s%s", f1, f2) != 2 ||
 137                             strcasecmp(f1, "badtty"))
 138                                 break;
 139                         c_tty(f2);
 140                         break;
 141                 case 'g':               /* game */
 142                         if (sscanf(lbuf, "%s%s%s%s%s",
 143                             f1, f2, f3, f4, f5) != 5 || strcasecmp(f1, "game"))
 144                                 break;
 145                         c_game(f2, f3, f4, f5);
 146                         break;
 147                 case 't':               /* time */
 148                         if (sscanf(lbuf, "%s%s%s%s", f1, f2, f3, f4) != 4 ||
 149                             strcasecmp(f1, "time"))
 150                                 break;
 151                         c_day(f2, f3, f4);
 152                 }
 153         (void)fclose(cfp);
 154 }
 155
 156 /*
 157  * c_day --
 158  *      if day is today, see if okay to play
 159  */
 160 void
 161 c_day(s_day, s_start, s_stop)
 162         char *s_day, *s_start, *s_stop;
 163 {
 164         static const char *days[] = {
 165                 "sunday", "monday", "tuesday", "wednesday",
 166                 "thursday", "friday", "saturday",
 167         };
 168         static struct tm *ct;
 169         int start, stop;
 170
 171         if (!ct)
 172                 ct = localtime(&now);
 173         if (strcasecmp(s_day, days[ct->tm_wday]))
 174                 return;
 175         if (!isdigit(*s_start) || !isdigit(*s_stop))
 176                 return;
 177         start = atoi(s_start);
 178         stop = atoi(s_stop);
 179         if (ct->tm_hour >= start && ct->tm_hour < stop) {
 180                 (void)fputs("dm: Sorry, games are not available from ", stderr);
 181                 hour(start);
 182                 (void)fputs(" to ", stderr);
 183                 hour(stop);
 184                 (void)fputs(" today.\n", stderr);
 185                 exit(0);
 186         }
 187 }
 188
 189 /*
 190  * c_tty --
 191  *      decide if this tty can be used for games.
 192  */
 193 void
 194 c_tty(tty)
 195         char *tty;
 196 {
 197         static int first = 1;
 198         static char *p_tty;
 199
 200         if (first) {
 201                 p_tty = strrchr(gametty, '/');
 202                 first = 0;
 203         }
 204
 205         if (!strcmp(gametty, tty) || (p_tty && !strcmp(p_tty, tty))) {
 206                 (void)fprintf(stderr, "dm: Sorry, you may not play games on %s.\n", gametty);
 207                 exit(0);
 208         }
 209 }
 210
 211 /*
 212  * c_game --
 213  *      see if game can be played now.
 214  */
 215 void
 216 c_game(s_game, s_load, s_users, s_priority)
 217         char *s_game, *s_load, *s_users, *s_priority;
 218 {
 219         static int found;
 220
 221         if (found)
 222                 return;
 223         if (strcmp(game, s_game) && strcasecmp("default", s_game))
 224                 return;
 225         ++found;
 226         if (isdigit(*s_load) && atoi(s_load) < load()) {
 227                 (void)fputs("dm: Sorry, the load average is too high right now.\n", stderr);
 228                 exit(0);
 229         }
 230         if (isdigit(*s_users) && atoi(s_users) <= users()) {
 231                 (void)fputs("dm: Sorry, there are too many users logged on right now.\n", stderr);
 232                 exit(0);
 233         }
 234         if (isdigit(*s_priority))
 235                 priority = atoi(s_priority);
 236 }
 237
 238 /*
 239  * load --
 240  *      return 15 minute load average
 241  */
 242 double
 243 load()
 244 {
 245         double avenrun[3];
 246
 247         if (getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0])) < 0) {
 248                 (void)fputs("dm: getloadavg() failed.\n", stderr);
 249                 exit(1);
 250         }
 251         return(avenrun[2]);
 252 }
 253
 254 /*
 255  * users --
 256  *      return current number of users
 257  *      todo: check idle time; if idle more than X minutes, don't
 258  *      count them.
 259  */
 260 int
 261 users()
 262 {
 263
 264         int nusers, utmp;
 265         struct utmp buf;
 266
 267         if ((utmp = open(_PATH_UTMP, O_RDONLY, 0)) < 0) {
 268                 (void)fprintf(stderr, "dm: %s: %s\n",
 269                     _PATH_UTMP, strerror(errno));
 270                 exit(1);
 271         }
 272         for (nusers = 0; read(utmp, (char *)&buf, sizeof(struct utmp)) > 0;)
 273                 if (buf.ut_name[0] != '\0')
 274                         ++nusers;
 275         return(nusers);
 276 }
 277
 278 void
 279 nogamefile()
 280 {
 281         int fd, n;
 282         char buf[BUFSIZ];
 283
 284         if ((fd = open(_PATH_NOGAMES, O_RDONLY, 0)) >= 0) {
 285 #define MESG    "Sorry, no games right now.\n\n"
 286                 (void)write(2, MESG, sizeof(MESG) - 1);
 287                 while ((n = read(fd, buf, sizeof(buf))) > 0)
 288                         (void)write(2, buf, n);
 289                 exit(1);
 290         }
 291 }
 292
 293 /*
 294  * hour --
 295  *      print out the hour in human form
 296  */
 297 void
 298 hour(h)
 299         int h;
 300 {
 301         switch(h) {
 302         case 0:
 303                 (void)fputs("midnight", stderr);
 304                 break;
 305         case 12:
 306                 (void)fputs("noon", stderr);
 307                 break;
 308         default:
 309                 if (h > 12)
 310                         (void)fprintf(stderr, "%dpm", h - 12);
 311                 else
 312                         (void)fprintf(stderr, "%dam", h);
 313         }
 314 }
 315
 316 #ifdef LOG
 317 /*
 318  * logfile --
 319  *      log play of game
 320  */
 321 logfile()
 322 {
 323         struct passwd *pw;
 324         FILE *lp;
 325         uid_t uid;
 326         int lock_cnt;
 327
 328         if (lp = fopen(_PATH_LOG, "a")) {
 329                 for (lock_cnt = 0;; ++lock_cnt) {
 330                         if (!flock(fileno(lp), LOCK_EX))
 331                                 break;
 332                         if (lock_cnt == 4) {
 333                                 perror("dm: log lock");
 334                                 (void)fclose(lp);
 335                                 return;
 336                         }
 337                         sleep((u_int)1);
 338                 }
 339                 if (pw = getpwuid(uid = getuid()))
 340                         fputs(pw->pw_name, lp);
 341                 else
 342                         fprintf(lp, "%u", uid);
 343                 fprintf(lp, "\t%s\t%s\t%s", game, gametty, ctime(&now));
 344                 (void)fclose(lp);
 345                 (void)flock(fileno(lp), LOCK_UN);
 346         }
 347 }
 348 #endif /* LOG */