games/dm/dm.c

   1 /*      $NetBSD: dm.c,v 1.28 2009/08/12 05:51:59 dholland 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. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 __COPYRIGHT("@(#) Copyright (c) 1987, 1993\
  35  The Regents of the University of California.  All rights reserved.");
  36 #endif /* not lint */
  37
  38 #ifndef lint
  39 #if 0
  40 static char sccsid[] = "@(#)dm.c        8.1 (Berkeley) 5/31/93";
  41 #else
  42 __RCSID("$NetBSD: dm.c,v 1.28 2009/08/12 05:51:59 dholland Exp $");
  43 #endif
  44 #endif /* not lint */
  45
  46 #include <sys/param.h>
  47 #include <sys/file.h>
  48 #include <sys/time.h>
  49 #include <sys/resource.h>
  50
  51 #include <err.h>
  52 #include <ctype.h>
  53 #include <errno.h>
  54 #include <pwd.h>
  55 #include <stdio.h>
  56 #include <stdlib.h>
  57 #include <string.h>
  58 #include <time.h>
  59 #include <unistd.h>
  60
  61 #include "utmpentry.h"
  62 #include "pathnames.h"
  63
  64 static time_t   now;                    /* current time value */
  65 static int      priority = 0;           /* priority game runs at */
  66 static char     *game,                  /* requested game */
  67                 *gametty;               /* from tty? */
  68
  69 static void c_day(const char *, const char *, const char *);
  70 static void c_game(const char *, const char  *, const char *, const char *);
  71 static void c_tty(const char *);
  72 static const char *hour(int);
  73 static double load(void);
  74 static void nogamefile(void);
  75 static void play(char **) __dead;
  76 static void read_config(void);
  77 static int users(void);
  78
  79 #ifdef LOG
  80 static void logfile(void);
  81 #endif
  82
  83 int
  84 main(int argc __unused, char *argv[])
  85 {
  86         char *cp;
  87
  88         nogamefile();
  89         game = (cp = strrchr(*argv, '/')) ? ++cp : *argv;
  90
  91         if (!strcmp(game, "dm"))
  92                 exit(0);
  93
  94         gametty = ttyname(0);
  95         unsetenv("TZ");
  96         (void)time(&now);
  97         read_config();
  98 #ifdef LOG
  99         logfile();
 100 #endif
 101         play(argv);
 102         /*NOTREACHED*/
 103         return (0);
 104 }
 105
 106 /*
 107  * play --
 108  *      play the game
 109  */
 110 static void
 111 play(char **args)
 112 {
 113         char pbuf[MAXPATHLEN];
 114
 115         snprintf(pbuf, sizeof(pbuf), "%s%s", _PATH_HIDE, game);
 116         if (priority > 0)       /* < 0 requires root */
 117                 (void)setpriority(PRIO_PROCESS, 0, priority);
 118         execv(pbuf, args);
 119         err(1, "%s", pbuf);
 120 }
 121
 122 /*
 123  * read_config --
 124  *      read through config file, looking for key words.
 125  */
 126 static void
 127 read_config(void)
 128 {
 129         FILE *cfp;
 130         char lbuf[BUFSIZ], f1[40], f2[40], f3[40], f4[40], f5[40];
 131
 132         if (!(cfp = fopen(_PATH_CONFIG, "r")))
 133                 return;
 134         while (fgets(lbuf, sizeof(lbuf), cfp))
 135                 switch (*lbuf) {
 136                 case 'b':               /* badtty */
 137                         if (sscanf(lbuf, "%39s%39s", f1, f2) != 2 ||
 138                             strcasecmp(f1, "badtty"))
 139                                 break;
 140                         c_tty(f2);
 141                         break;
 142                 case 'g':               /* game */
 143                         if (sscanf(lbuf, "%39s%39s%39s%39s%39s",
 144                             f1, f2, f3, f4, f5) != 5 || strcasecmp(f1, "game"))
 145                                 break;
 146                         c_game(f2, f3, f4, f5);
 147                         break;
 148                 case 't':               /* time */
 149                         if (sscanf(lbuf, "%39s%39s%39s%39s", f1, f2, f3, f4) != 4 ||
 150                             strcasecmp(f1, "time"))
 151                                 break;
 152                         c_day(f2, f3, f4);
 153                 }
 154         (void)fclose(cfp);
 155 }
 156
 157 /*
 158  * c_day --
 159  *      if day is today, see if okay to play
 160  */
 161 static void
 162 c_day(const char *s_day, const char *s_start, const char *s_stop)
 163 {
 164         static const char *const 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((unsigned char)*s_start) ||
 176             !isdigit((unsigned char)*s_stop))
 177                 return;
 178         start = atoi(s_start);
 179         stop = atoi(s_stop);
 180         if (ct->tm_hour >= start && ct->tm_hour < stop) {
 181                 if (start == 0 && stop == 24)
 182                         errx(0, "Sorry, games are not available today.");
 183                 else
 184                         errx(0, "Sorry, games are not available from %s to %s today.",
 185                              hour(start), hour(stop));
 186         }
 187 }
 188
 189 /*
 190  * c_tty --
 191  *      decide if this tty can be used for games.
 192  */
 193 static void
 194 c_tty(const char *tty)
 195 {
 196         static int first = 1;
 197         static char *p_tty;
 198
 199         if (first) {
 200                 p_tty = strrchr(gametty, '/');
 201                 first = 0;
 202         }
 203
 204         if (!strcmp(gametty, tty) || (p_tty && !strcmp(p_tty, tty)))
 205                 errx(1, "Sorry, you may not play games on %s.", gametty);
 206 }
 207
 208 /*
 209  * c_game --
 210  *      see if game can be played now.
 211  */
 212 static void
 213 c_game(const char *s_game, const char *s_load, const char *s_users,
 214        const char *s_priority)
 215 {
 216         static int found;
 217
 218         if (found)
 219                 return;
 220         if (strcmp(game, s_game) && strcasecmp("default", s_game))
 221                 return;
 222         ++found;
 223         if (isdigit((unsigned char)*s_load) && atoi(s_load) < load())
 224                 errx(0, "Sorry, the load average is too high right now.");
 225         if (isdigit((unsigned char)*s_users) && atoi(s_users) <= users())
 226                 errx(0, "Sorry, there are too many users logged on right now.");
 227         if (isdigit((unsigned char)*s_priority))
 228                 priority = atoi(s_priority);
 229 }
 230
 231 /*
 232  * load --
 233  *      return 15 minute load average
 234  */
 235 static double
 236 load(void)
 237 {
 238         double avenrun[3];
 239
 240         if (getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0])) < 0)
 241                 err(1, "getloadavg() failed");
 242         return (avenrun[2]);
 243 }
 244
 245 /*
 246  * users --
 247  *      return current number of users
 248  *      todo: check idle time; if idle more than X minutes, don't
 249  *      count them.
 250  */
 251 static int
 252 users(void)
 253 {
 254         struct utmpentry *ep;
 255         int nusers;
 256
 257         nusers = getutentries(NULL, &ep);
 258         return nusers;
 259 }
 260
 261 static void
 262 nogamefile(void)
 263 {
 264         int fd, n;
 265         char buf[BUFSIZ];
 266
 267         if ((fd = open(_PATH_NOGAMES, O_RDONLY, 0)) >= 0) {
 268 #define MESG    "Sorry, no games right now.\n\n"
 269                 (void)write(2, MESG, sizeof(MESG) - 1);
 270                 while ((n = read(fd, buf, sizeof(buf))) > 0)
 271                         (void)write(2, buf, n);
 272                 exit(1);
 273         }
 274 }
 275
 276 /*
 277  * hour --
 278  *      print out the hour in human form
 279  */
 280 static const char *
 281 hour(int h)
 282 {
 283         static const char *const hours[] = {
 284             "midnight", "1am", "2am", "3am", "4am", "5am",
 285             "6am", "7am", "8am", "9am", "10am", "11am",
 286             "noon", "1pm", "2pm", "3pm", "4pm", "5pm",
 287             "6pm", "7pm", "8pm", "9pm", "10pm", "11pm", "midnight" };
 288
 289         if (h < 0 || h > 24)
 290                 return ("BAD TIME");
 291         else
 292                 return (hours[h]);
 293 }
 294
 295 #ifdef LOG
 296 /*
 297  * logfile --
 298  *      log play of game
 299  */
 300 static void
 301 logfile(void)
 302 {
 303         struct passwd *pw;
 304         FILE *lp;
 305         uid_t uid;
 306         int lock_cnt;
 307
 308         if (lp = fopen(_PATH_LOG, "a")) {
 309                 for (lock_cnt = 0;; ++lock_cnt) {
 310                         if (!flock(fileno(lp), LOCK_EX))
 311                                 break;
 312                         if (lock_cnt == 4) {
 313                                 warnx("log lock");
 314                                 (void)fclose(lp);
 315                                 return;
 316                         }
 317                         sleep(1);
 318                 }
 319                 if (pw = getpwuid(uid = getuid()))
 320                         fputs(pw->pw_name, lp);
 321                 else
 322                         fprintf(lp, "%u", uid);
 323                 fprintf(lp, "\t%s\t%s\t%s", game, gametty, ctime(&now));
 324                 (void)flock(fileno(lp), LOCK_UN);
 325                 (void)fclose(lp);
 326         }
 327 }
 328 #endif /* LOG */