dm/dm.c

   1 /*      $NetBSD: dm.c,v 1.8 1997/11/19 08:24:09 mrg 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 1.8 1997/11/19 08:24:09 mrg 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((char *, char *, char *));
  75 void    c_game __P((char *, char  *, char *, char *));
  76 void    c_tty __P((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 **));
  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         (void)time(&now);
 100         read_config();
 101 #ifdef LOG
 102         logfile();
 103 #endif
 104         play(argv);
 105         /*NOTREACHED*/
 106         return(0);
 107 }
 108
 109 /*
 110  * play --
 111  *      play the game
 112  */
 113 void
 114 play(args)
 115         char **args;
 116 {
 117         char pbuf[MAXPATHLEN];
 118
 119         (void)strncpy(pbuf, _PATH_HIDE, sizeof(pbuf) - 1);
 120         (void)strncpy(pbuf + sizeof(_PATH_HIDE) - 1, game,
 121             sizeof(pbuf) - sizeof(_PATH_HIDE) - 1);
 122         pbuf[sizeof(pbuf) - 1] = '\0';
 123         if (priority > 0)       /* < 0 requires root */
 124                 (void)setpriority(PRIO_PROCESS, 0, priority);
 125         execv(pbuf, args);
 126         err(1, "%s", pbuf);
 127 }
 128
 129 /*
 130  * read_config --
 131  *      read through config file, looking for key words.
 132  */
 133 void
 134 read_config()
 135 {
 136         FILE *cfp;
 137         char lbuf[BUFSIZ], f1[40], f2[40], f3[40], f4[40], f5[40];
 138
 139         if (!(cfp = fopen(_PATH_CONFIG, "r")))
 140                 return;
 141         while (fgets(lbuf, sizeof(lbuf), cfp))
 142                 switch(*lbuf) {
 143                 case 'b':               /* badtty */
 144                         if (sscanf(lbuf, "%s%s", f1, f2) != 2 ||
 145                             strcasecmp(f1, "badtty"))
 146                                 break;
 147                         c_tty(f2);
 148                         break;
 149                 case 'g':               /* game */
 150                         if (sscanf(lbuf, "%s%s%s%s%s",
 151                             f1, f2, f3, f4, f5) != 5 || strcasecmp(f1, "game"))
 152                                 break;
 153                         c_game(f2, f3, f4, f5);
 154                         break;
 155                 case 't':               /* time */
 156                         if (sscanf(lbuf, "%s%s%s%s", f1, f2, f3, f4) != 4 ||
 157                             strcasecmp(f1, "time"))
 158                                 break;
 159                         c_day(f2, f3, f4);
 160                 }
 161         (void)fclose(cfp);
 162 }
 163
 164 /*
 165  * c_day --
 166  *      if day is today, see if okay to play
 167  */
 168 void
 169 c_day(s_day, s_start, s_stop)
 170         char *s_day, *s_start, *s_stop;
 171 {
 172         static char *days[] = {
 173                 "sunday", "monday", "tuesday", "wednesday",
 174                 "thursday", "friday", "saturday",
 175         };
 176         static struct tm *ct;
 177         int start, stop;
 178
 179         if (!ct)
 180                 ct = localtime(&now);
 181         if (strcasecmp(s_day, days[ct->tm_wday]))
 182                 return;
 183         if (!isdigit(*s_start) || !isdigit(*s_stop))
 184                 return;
 185         start = atoi(s_start);
 186         stop = atoi(s_stop);
 187         if (ct->tm_hour >= start && ct->tm_hour < stop)
 188                 errx(0, "Sorry, games are not available from %s to %s today.",
 189                     hour(start), hour(stop));
 190 }
 191
 192 /*
 193  * c_tty --
 194  *      decide if this tty can be used for games.
 195  */
 196 void
 197 c_tty(tty)
 198         char *tty;
 199 {
 200         static int first = 1;
 201         static char *p_tty;
 202
 203         if (first) {
 204                 p_tty = strrchr(gametty, '/');
 205                 first = 0;
 206         }
 207
 208         if (!strcmp(gametty, tty) || (p_tty && !strcmp(p_tty, tty)))
 209                 errx(1, "Sorry, you may not play games on %s.", gametty);
 210 }
 211
 212 /*
 213  * c_game --
 214  *      see if game can be played now.
 215  */
 216 void
 217 c_game(s_game, s_load, s_users, s_priority)
 218         char *s_game, *s_load, *s_users, *s_priority;
 219 {
 220         static int found;
 221
 222         if (found)
 223                 return;
 224         if (strcmp(game, s_game) && strcasecmp("default", s_game))
 225                 return;
 226         ++found;
 227         if (isdigit(*s_load) && atoi(s_load) < load())
 228                 errx(0, "Sorry, the load average is too high right now.");
 229         if (isdigit(*s_users) && atoi(s_users) <= users())
 230                 errx(0, "Sorry, there are too many users logged on right now.");
 231         if (isdigit(*s_priority))
 232                 priority = atoi(s_priority);
 233 }
 234
 235 /*
 236  * load --
 237  *      return 15 minute load average
 238  */
 239 double
 240 load()
 241 {
 242         double avenrun[3];
 243
 244         if (getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0])) < 0)
 245                 err(1, "getloadavg() failed.");
 246         return(avenrun[2]);
 247 }
 248
 249 /*
 250  * users --
 251  *      return current number of users
 252  *      todo: check idle time; if idle more than X minutes, don't
 253  *      count them.
 254  */
 255 int
 256 users()
 257 {
 258
 259         int nusers, utmp;
 260         struct utmp buf;
 261
 262         if ((utmp = open(_PATH_UTMP, O_RDONLY, 0)) < 0)
 263                 err(1, "%s", _PATH_UTMP);
 264         for (nusers = 0; read(utmp, (char *)&buf, sizeof(struct utmp)) > 0;)
 265                 if (buf.ut_name[0] != '\0')
 266                         ++nusers;
 267         return(nusers);
 268 }
 269
 270 void
 271 nogamefile()
 272 {
 273         int fd, n;
 274         char buf[BUFSIZ];
 275
 276         if ((fd = open(_PATH_NOGAMES, O_RDONLY, 0)) >= 0) {
 277 #define MESG    "Sorry, no games right now.\n\n"
 278                 (void)write(2, MESG, sizeof(MESG) - 1);
 279                 while ((n = read(fd, buf, sizeof(buf))) > 0)
 280                         (void)write(2, buf, n);
 281                 exit(1);
 282         }
 283 }
 284
 285 /*
 286  * hour --
 287  *      print out the hour in human form
 288  */
 289 const char *
 290 hour(h)
 291         int h;
 292 {
 293         static char *hours[] = {
 294             "midnight", "1am", "2am", "3am", "4am", "5am",
 295             "6am", "7am", "8am", "9am", "10am", "11am",
 296             "noon", "1pm", "2pm", "3pm", "4pm", "5pm",
 297             "6pm", "7pm", "8pm", "9pm", "10pm", "11pm" };
 298
 299         if (h < 0 || h > 23)
 300                 return "BAD TIME";
 301         else
 302                 return hours[h];
 303 }
 304
 305 #ifdef LOG
 306 /*
 307  * logfile --
 308  *      log play of game
 309  */
 310 logfile()
 311 {
 312         struct passwd *pw;
 313         FILE *lp;
 314         uid_t uid;
 315         int lock_cnt;
 316
 317         if (lp = fopen(_PATH_LOG, "a")) {
 318                 for (lock_cnt = 0;; ++lock_cnt) {
 319                         if (!flock(fileno(lp), LOCK_EX))
 320                                 break;
 321                         if (lock_cnt == 4) {
 322                                 warnx("log lock");
 323                                 (void)fclose(lp);
 324                                 return;
 325                         }
 326                         sleep((u_int)1);
 327                 }
 328                 if (pw = getpwuid(uid = getuid()))
 329                         fputs(pw->pw_name, lp);
 330                 else
 331                         fprintf(lp, "%u", uid);
 332                 fprintf(lp, "\t%s\t%s\t%s", game, gametty, ctime(&now));
 333                 (void)fclose(lp);
 334                 (void)flock(fileno(lp), LOCK_UN);
 335         }
 336 }
 337 #endif /* LOG */