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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#) Copyright (c) 1987, 1993 The Regents of the University of California.  All rights reserved.
  30  * @(#)dm.c     8.1 (Berkeley) 5/31/93
  31  * $FreeBSD: src/games/dm/dm.c,v 1.8 1999/12/10 02:54:18 billf Exp $
  32  * $DragonFly: src/games/dm/dm.c,v 1.4 2006/08/08 17:05:14 pavalos Exp $
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/file.h>
  37 #include <sys/time.h>
  38 #include <sys/resource.h>
  39
  40 #include <ctype.h>
  41 #include <errno.h>
  42 #include <nlist.h>
  43 #include <pwd.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <time.h>
  48 #include <unistd.h>
  49 #include "utmpentry.h"
  50
  51 #include "pathnames.h"
  52
  53 static time_t   now;                    /* current time value */
  54 static int      priority = 0;           /* priority game runs at */
  55 static char     *game,                  /* requested game */
  56                 *gametty;               /* from tty? */
  57
  58 static void     c_day(char *, char *, char *);
  59 static void     c_tty(char *);
  60 static void     c_game(char *, char *, char *, char *);
  61 static void     hour(int);
  62 static double   load(void);
  63 static void     nogamefile(void);
  64 static void     play(char **);
  65 static void     read_config(void);
  66 static int      users(void);
  67 #ifdef LOG
  68 static void     logfile(void);
  69 #endif
  70
  71 int
  72 main(__unused int argc, char *argv[])
  73 {
  74         char *cp;
  75
  76         nogamefile();
  77         game = (cp = strrchr(*argv, '/')) ? ++cp : *argv;
  78
  79         if (!strcmp(game, "dm"))
  80                 exit(0);
  81
  82         gametty = ttyname(0);
  83         unsetenv("TZ");
  84         time(&now);
  85         read_config();
  86 #ifdef LOG
  87         logfile();
  88 #endif
  89         play(argv);
  90         /*NOTREACHED*/
  91         exit(EXIT_FAILURE);
  92 }
  93
  94 /*
  95  * play --
  96  *      play the game
  97  */
  98 static void
  99 play(char **args)
 100 {
 101         char pbuf[MAXPATHLEN];
 102
 103         if (sizeof(_PATH_HIDE) + strlen(game) > sizeof(pbuf)) {
 104                 fprintf(stderr, "dm: %s/%s: %s\n", _PATH_HIDE, game,
 105                         strerror(ENAMETOOLONG));
 106                 exit(1);
 107         }
 108         strcpy(pbuf, _PATH_HIDE);
 109         strcpy(pbuf + sizeof(_PATH_HIDE) - 1, game);
 110         if (priority > 0)       /* < 0 requires root */
 111                 setpriority(PRIO_PROCESS, 0, priority);
 112         execv(pbuf, args);
 113         fprintf(stderr, "dm: %s: %s\n", pbuf, strerror(errno));
 114         exit(1);
 115 }
 116
 117 /*
 118  * read_config --
 119  *      read through config file, looking for key words.
 120  */
 121 static void
 122 read_config(void)
 123 {
 124         FILE *cfp;
 125         char lbuf[BUFSIZ], f1[40], f2[40], f3[40], f4[40], f5[40];
 126
 127         if (!(cfp = fopen(_PATH_CONFIG, "r")))
 128                 return;
 129         while (fgets(lbuf, sizeof(lbuf), cfp))
 130                 switch(*lbuf) {
 131                 case 'b':               /* badtty */
 132                         if (sscanf(lbuf, "%s%s", f1, f2) != 2 ||
 133                             strcasecmp(f1, "badtty"))
 134                                 break;
 135                         c_tty(f2);
 136                         break;
 137                 case 'g':               /* game */
 138                         if (sscanf(lbuf, "%s%s%s%s%s",
 139                             f1, f2, f3, f4, f5) != 5 || strcasecmp(f1, "game"))
 140                                 break;
 141                         c_game(f2, f3, f4, f5);
 142                         break;
 143                 case 't':               /* time */
 144                         if (sscanf(lbuf, "%s%s%s%s", f1, f2, f3, f4) != 4 ||
 145                             strcasecmp(f1, "time"))
 146                                 break;
 147                         c_day(f2, f3, f4);
 148                 }
 149         fclose(cfp);
 150 }
 151
 152 /*
 153  * c_day --
 154  *      if day is today, see if okay to play
 155  */
 156 static void
 157 c_day(char *s_day, char *s_start, char *s_stop)
 158 {
 159         static const char *days[] = {
 160                 "sunday", "monday", "tuesday", "wednesday",
 161                 "thursday", "friday", "saturday",
 162         };
 163         static struct tm *ct;
 164         int start, stop;
 165
 166         if (!ct)
 167                 ct = localtime(&now);
 168         if (strcasecmp(s_day, days[ct->tm_wday]))
 169                 return;
 170         if (!isdigit(*s_start) || !isdigit(*s_stop))
 171                 return;
 172         start = atoi(s_start);
 173         stop = atoi(s_stop);
 174         if (ct->tm_hour >= start && ct->tm_hour < stop) {
 175                 fputs("dm: Sorry, games are not available from ", stderr);
 176                 hour(start);
 177                 fputs(" to ", stderr);
 178                 hour(stop);
 179                 fputs(" today.\n", stderr);
 180                 exit(0);
 181         }
 182 }
 183
 184 /*
 185  * c_tty --
 186  *      decide if this tty can be used for games.
 187  */
 188 static void
 189 c_tty(char *tty)
 190 {
 191         static int first = 1;
 192         static char *p_tty;
 193
 194         if (first) {
 195                 p_tty = strrchr(gametty, '/');
 196                 first = 0;
 197         }
 198
 199         if (!strcmp(gametty, tty) || (p_tty && !strcmp(p_tty, tty))) {
 200                 fprintf(stderr, "dm: Sorry, you may not play games on %s.\n", gametty);
 201                 exit(0);
 202         }
 203 }
 204
 205 /*
 206  * c_game --
 207  *      see if game can be played now.
 208  */
 209 static void
 210 c_game(char *s_game, char *s_load, char *s_users, char *s_priority)
 211 {
 212         static int found;
 213
 214         if (found)
 215                 return;
 216         if (strcmp(game, s_game) && strcasecmp("default", s_game))
 217                 return;
 218         ++found;
 219         if (isdigit(*s_load) && atoi(s_load) < load()) {
 220                 fputs("dm: Sorry, the load average is too high right now.\n", stderr);
 221                 exit(0);
 222         }
 223         if (isdigit(*s_users) && atoi(s_users) <= users()) {
 224                 fputs("dm: Sorry, there are too many users logged on right now.\n", stderr);
 225                 exit(0);
 226         }
 227         if (isdigit(*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                 fputs("dm: getloadavg() failed.\n", stderr);
 242                 exit(1);
 243         }
 244         return(avenrun[2]);
 245 }
 246
 247 /*
 248  * users --
 249  *      return current number of users
 250  *      todo: check idle time; if idle more than X minutes, don't
 251  *      count them.
 252  */
 253 static int
 254 users(void)
 255 {
 256         struct utmpentry *ep = NULL;    /* avoid gcc warnings */
 257         int nusers = 0;
 258
 259         getutentries(NULL, &ep);
 260         for (; ep; ep = ep->next)
 261                 ++nusers;
 262
 263         return(nusers);
 264 }
 265
 266 static void
 267 nogamefile(void)
 268 {
 269         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                 write(2, MESG, sizeof(MESG) - 1);
 275                 while ((n = read(fd, buf, sizeof(buf))) > 0)
 276                         write(2, buf, n);
 277                 exit(1);
 278         }
 279 }
 280
 281 /*
 282  * hour --
 283  *      print out the hour in human form
 284  */
 285 static void
 286 hour(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 static void
 309 logfile(void)
 310 {
 311         struct passwd *pw;
 312         FILE *lp;
 313         uid_t uid;
 314         int lock_cnt;
 315
 316         if (lp = fopen(_PATH_LOG, "a")) {
 317                 for (lock_cnt = 0;; ++lock_cnt) {
 318                         if (!flock(fileno(lp), LOCK_EX))
 319                                 break;
 320                         if (lock_cnt == 4) {
 321                                 perror("dm: log lock");
 322                                 fclose(lp);
 323                                 return;
 324                         }
 325                         sleep((u_int)1);
 326                 }
 327                 if (pw = getpwuid(uid = getuid()))
 328                         fputs(pw->pw_name, lp);
 329                 else
 330                         fprintf(lp, "%u", uid);
 331                 fprintf(lp, "\t%s\t%s\t%s", game, gametty, ctime(&now));
 332                 fclose(lp);
 333                 flock(fileno(lp), LOCK_UN);
 334         }
 335 }
 336 #endif /* LOG */