dm/dm.c

   1 /*      $NetBSD: dm.c,v 1.13 1999/09/19 18:13:41 jsm 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 #include <sys/cdefs.h>
  37 #ifndef lint
  38 __COPYRIGHT("@(#) 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 __RCSID("$NetBSD: dm.c,v 1.13 1999/09/19 18:13:41 jsm 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 <err.h>
  56 #include <ctype.h>
  57 #include <errno.h>
  58 #include <nlist.h>
  59 #include <pwd.h>
  60 #include <stdio.h>
  61 #include <stdlib.h>
  62 #include <string.h>
  63 #include <time.h>
  64 #include <unistd.h>
  65 #include <utmp.h>
  66
  67 #include "pathnames.h"
  68
  69 static time_t   now;                    /* current time value */
  70 static int      priority = 0;           /* priority game runs at */
  71 static char     *game,                  /* requested game */
  72                 *gametty;               /* from tty? */
  73
  74 void    c_day __P((const char *, const char *, const char *));
  75 void    c_game __P((const char *, const char  *, const char *, const char *));
  76 void    c_tty __P((const char *));
  77 const char *hour __P((int));
  78 double  load __P((void));
  79 int     main __P((int, char *[]));
  80 void    nogamefile __P((void));
  81 void    play __P((char **)) __attribute__((__noreturn__));
  82 void    read_config __P((void));
  83 int     users __P((void));
  84
  85 int
  86 main(argc, argv)
  87         int argc;
  88         char *argv[];
  89 {
  90         char *cp;
  91
  92         nogamefile();
  93         game = (cp = strrchr(*argv, '/')) ? ++cp : *argv;
  94
  95         if (!strcmp(game, "dm"))
  96                 exit(0);
  97
  98         gametty = ttyname(0);
  99         unsetenv("TZ");
 100         (void)time(&now);
 101         read_config();
 102 #ifdef LOG
 103         logfile();
 104 #endif
 105         play(argv);
 106         /*NOTREACHED*/
 107         return (0);
 108 }
 109
 110 /*
 111  * play --
 112  *      play the game
 113  */
 114 void
 115 play(args)
 116         char **args;
 117 {
 118         char pbuf[MAXPATHLEN];
 119
 120         (void)strncpy(pbuf, _PATH_HIDE, sizeof(pbuf) - 1);
 121         (void)strncpy(pbuf + sizeof(_PATH_HIDE) - 1, game,
 122             sizeof(pbuf) - sizeof(_PATH_HIDE) - 1);
 123         pbuf[sizeof(pbuf) - 1] = '\0';
 124         if (priority > 0)       /* < 0 requires root */
 125                 (void)setpriority(PRIO_PROCESS, 0, priority);
 126         execv(pbuf, args);
 127         err(1, "%s", pbuf);
 128 }
 129
 130 /*
 131  * read_config --
 132  *      read through config file, looking for key words.
 133  */
 134 void
 135 read_config()
 136 {
 137         FILE *cfp;
 138         char lbuf[BUFSIZ], f1[40], f2[40], f3[40], f4[40], f5[40];
 139
 140         if (!(cfp = fopen(_PATH_CONFIG, "r")))
 141                 return;
 142         while (fgets(lbuf, sizeof(lbuf), cfp))
 143                 switch (*lbuf) {
 144                 case 'b':               /* badtty */
 145                         if (sscanf(lbuf, "%s%s", f1, f2) != 2 ||
 146                             strcasecmp(f1, "badtty"))
 147                                 break;
 148                         c_tty(f2);
 149                         break;
 150                 case 'g':               /* game */
 151                         if (sscanf(lbuf, "%s%s%s%s%s",
 152                             f1, f2, f3, f4, f5) != 5 || strcasecmp(f1, "game"))
 153                                 break;
 154                         c_game(f2, f3, f4, f5);
 155                         break;
 156                 case 't':               /* time */
 157                         if (sscanf(lbuf, "%s%s%s%s", f1, f2, f3, f4) != 4 ||
 158                             strcasecmp(f1, "time"))
 159                                 break;
 160                         c_day(f2, f3, f4);
 161                 }
 162         (void)fclose(cfp);
 163 }
 164
 165 /*
 166  * c_day --
 167  *      if day is today, see if okay to play
 168  */
 169 void
 170 c_day(s_day, s_start, s_stop)
 171         const char *s_day, *s_start, *s_stop;
 172 {
 173         static const char *const days[] = {
 174                 "sunday", "monday", "tuesday", "wednesday",
 175                 "thursday", "friday", "saturday",
 176         };
 177         static struct tm *ct;
 178         int start, stop;
 179
 180         if (!ct)
 181                 ct = localtime(&now);
 182         if (strcasecmp(s_day, days[ct->tm_wday]))
 183                 return;
 184         if (!isdigit(*s_start) || !isdigit(*s_stop))
 185                 return;
 186         start = atoi(s_start);
 187         stop = atoi(s_stop);
 188         if (ct->tm_hour >= start && ct->tm_hour < stop) {
 189                 if (start == 0 && stop == 24)
 190                         errx(0, "Sorry, games are not available today.");
 191                 else
 192                         errx(0, "Sorry, games are not available from %s to %s today.",
 193                              hour(start), hour(stop));
 194         }
 195 }
 196
 197 /*
 198  * c_tty --
 199  *      decide if this tty can be used for games.
 200  */
 201 void
 202 c_tty(tty)
 203         const char *tty;
 204 {
 205         static int first = 1;
 206         static char *p_tty;
 207
 208         if (first) {
 209                 p_tty = strrchr(gametty, '/');
 210                 first = 0;
 211         }
 212
 213         if (!strcmp(gametty, tty) || (p_tty && !strcmp(p_tty, tty)))
 214                 errx(1, "Sorry, you may not play games on %s.", gametty);
 215 }
 216
 217 /*
 218  * c_game --
 219  *      see if game can be played now.
 220  */
 221 void
 222 c_game(s_game, s_load, s_users, s_priority)
 223         const char *s_game, *s_load, *s_users, *s_priority;
 224 {
 225         static int found;
 226
 227         if (found)
 228                 return;
 229         if (strcmp(game, s_game) && strcasecmp("default", s_game))
 230                 return;
 231         ++found;
 232         if (isdigit(*s_load) && atoi(s_load) < load())
 233                 errx(0, "Sorry, the load average is too high right now.");
 234         if (isdigit(*s_users) && atoi(s_users) <= users())
 235                 errx(0, "Sorry, there are too many users logged on right now.");
 236         if (isdigit(*s_priority))
 237                 priority = atoi(s_priority);
 238 }
 239
 240 /*
 241  * load --
 242  *      return 15 minute load average
 243  */
 244 double
 245 load()
 246 {
 247         double avenrun[3];
 248
 249         if (getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0])) < 0)
 250                 err(1, "getloadavg() failed.");
 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                 err(1, "%s", _PATH_UTMP);
 269         for (nusers = 0; read(utmp, (char *)&buf, sizeof(struct utmp)) > 0;)
 270                 if (buf.ut_name[0] != '\0')
 271                         ++nusers;
 272         return (nusers);
 273 }
 274
 275 void
 276 nogamefile()
 277 {
 278         int fd, n;
 279         char buf[BUFSIZ];
 280
 281         if ((fd = open(_PATH_NOGAMES, O_RDONLY, 0)) >= 0) {
 282 #define MESG    "Sorry, no games right now.\n\n"
 283                 (void)write(2, MESG, sizeof(MESG) - 1);
 284                 while ((n = read(fd, buf, sizeof(buf))) > 0)
 285                         (void)write(2, buf, n);
 286                 exit(1);
 287         }
 288 }
 289
 290 /*
 291  * hour --
 292  *      print out the hour in human form
 293  */
 294 const char *
 295 hour(h)
 296         int h;
 297 {
 298         static const char *const hours[] = {
 299             "midnight", "1am", "2am", "3am", "4am", "5am",
 300             "6am", "7am", "8am", "9am", "10am", "11am",
 301             "noon", "1pm", "2pm", "3pm", "4pm", "5pm",
 302             "6pm", "7pm", "8pm", "9pm", "10pm", "11pm", "midnight" };
 303
 304         if (h < 0 || h > 24)
 305                 return ("BAD TIME");
 306         else
 307                 return (hours[h]);
 308 }
 309
 310 #ifdef LOG
 311 /*
 312  * logfile --
 313  *      log play of game
 314  */
 315 logfile()
 316 {
 317         struct passwd *pw;
 318         FILE *lp;
 319         uid_t uid;
 320         int lock_cnt;
 321
 322         if (lp = fopen(_PATH_LOG, "a")) {
 323                 for (lock_cnt = 0;; ++lock_cnt) {
 324                         if (!flock(fileno(lp), LOCK_EX))
 325                                 break;
 326                         if (lock_cnt == 4) {
 327                                 warnx("log lock");
 328                                 (void)fclose(lp);
 329                                 return;
 330                         }
 331                         sleep((u_int)1);
 332                 }
 333                 if (pw = getpwuid(uid = getuid()))
 334                         fputs(pw->pw_name, lp);
 335                 else
 336                         fprintf(lp, "%u", uid);
 337                 fprintf(lp, "\t%s\t%s\t%s", game, gametty, ctime(&now));
 338                 (void)fclose(lp);
 339                 (void)flock(fileno(lp), LOCK_UN);
 340         }
 341 }
 342 #endif /* LOG */