dm/dm.c

   1 /*      $NetBSD: dm.c,v 1.17 2002/08/02 03:06:24 christos 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 1.17 2002/08/02 03:06:24 christos 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 <pwd.h>
  59 #include <stdio.h>
  60 #include <stdlib.h>
  61 #include <string.h>
  62 #include <time.h>
  63 #include <unistd.h>
  64
  65 #include "utmpentry.h"
  66 #include "pathnames.h"
  67
  68 static time_t   now;                    /* current time value */
  69 static int      priority = 0;           /* priority game runs at */
  70 static char     *game,                  /* requested game */
  71                 *gametty;               /* from tty? */
  72
  73 void    c_day __P((const char *, const char *, const char *));
  74 void    c_game __P((const char *, const char  *, const char *, const char *));
  75 void    c_tty __P((const char *));
  76 const char *hour __P((int));
  77 double  load __P((void));
  78 int     main __P((int, char *[]));
  79 void    nogamefile __P((void));
  80 void    play __P((char **)) __attribute__((__noreturn__));
  81 void    read_config __P((void));
  82 int     users __P((void));
  83
  84 int
  85 main(argc, argv)
  86         int argc;
  87         char *argv[];
  88 {
  89         char *cp;
  90
  91         nogamefile();
  92         game = (cp = strrchr(*argv, '/')) ? ++cp : *argv;
  93
  94         if (!strcmp(game, "dm"))
  95                 exit(0);
  96
  97         gametty = ttyname(0);
  98         unsetenv("TZ");
  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         snprintf(pbuf, sizeof(pbuf), "%s%s", _PATH_HIDE, game);
 120         if (priority > 0)       /* < 0 requires root */
 121                 (void)setpriority(PRIO_PROCESS, 0, priority);
 122         execv(pbuf, args);
 123         err(1, "%s", pbuf);
 124 }
 125
 126 /*
 127  * read_config --
 128  *      read through config file, looking for key words.
 129  */
 130 void
 131 read_config()
 132 {
 133         FILE *cfp;
 134         char lbuf[BUFSIZ], f1[40], f2[40], f3[40], f4[40], f5[40];
 135
 136         if (!(cfp = fopen(_PATH_CONFIG, "r")))
 137                 return;
 138         while (fgets(lbuf, sizeof(lbuf), cfp))
 139                 switch (*lbuf) {
 140                 case 'b':               /* badtty */
 141                         if (sscanf(lbuf, "%s%s", f1, f2) != 2 ||
 142                             strcasecmp(f1, "badtty"))
 143                                 break;
 144                         c_tty(f2);
 145                         break;
 146                 case 'g':               /* game */
 147                         if (sscanf(lbuf, "%s%s%s%s%s",
 148                             f1, f2, f3, f4, f5) != 5 || strcasecmp(f1, "game"))
 149                                 break;
 150                         c_game(f2, f3, f4, f5);
 151                         break;
 152                 case 't':               /* time */
 153                         if (sscanf(lbuf, "%s%s%s%s", f1, f2, f3, f4) != 4 ||
 154                             strcasecmp(f1, "time"))
 155                                 break;
 156                         c_day(f2, f3, f4);
 157                 }
 158         (void)fclose(cfp);
 159 }
 160
 161 /*
 162  * c_day --
 163  *      if day is today, see if okay to play
 164  */
 165 void
 166 c_day(s_day, s_start, s_stop)
 167         const char *s_day, *s_start, *s_stop;
 168 {
 169         static const char *const days[] = {
 170                 "sunday", "monday", "tuesday", "wednesday",
 171                 "thursday", "friday", "saturday",
 172         };
 173         static struct tm *ct;
 174         int start, stop;
 175
 176         if (!ct)
 177                 ct = localtime(&now);
 178         if (strcasecmp(s_day, days[ct->tm_wday]))
 179                 return;
 180         if (!isdigit(*s_start) || !isdigit(*s_stop))
 181                 return;
 182         start = atoi(s_start);
 183         stop = atoi(s_stop);
 184         if (ct->tm_hour >= start && ct->tm_hour < stop) {
 185                 if (start == 0 && stop == 24)
 186                         errx(0, "Sorry, games are not available today.");
 187                 else
 188                         errx(0, "Sorry, games are not available from %s to %s today.",
 189                              hour(start), hour(stop));
 190         }
 191 }
 192
 193 /*
 194  * c_tty --
 195  *      decide if this tty can be used for games.
 196  */
 197 void
 198 c_tty(tty)
 199         const char *tty;
 200 {
 201         static int first = 1;
 202         static char *p_tty;
 203
 204         if (first) {
 205                 p_tty = strrchr(gametty, '/');
 206                 first = 0;
 207         }
 208
 209         if (!strcmp(gametty, tty) || (p_tty && !strcmp(p_tty, tty)))
 210                 errx(1, "Sorry, you may not play games on %s.", gametty);
 211 }
 212
 213 /*
 214  * c_game --
 215  *      see if game can be played now.
 216  */
 217 void
 218 c_game(s_game, s_load, s_users, s_priority)
 219         const char *s_game, *s_load, *s_users, *s_priority;
 220 {
 221         static int found;
 222
 223         if (found)
 224                 return;
 225         if (strcmp(game, s_game) && strcasecmp("default", s_game))
 226                 return;
 227         ++found;
 228         if (isdigit(*s_load) && atoi(s_load) < load())
 229                 errx(0, "Sorry, the load average is too high right now.");
 230         if (isdigit(*s_users) && atoi(s_users) <= users())
 231                 errx(0, "Sorry, there are too many users logged on right now.");
 232         if (isdigit(*s_priority))
 233                 priority = atoi(s_priority);
 234 }
 235
 236 /*
 237  * load --
 238  *      return 15 minute load average
 239  */
 240 double
 241 load()
 242 {
 243         double avenrun[3];
 244
 245         if (getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0])) < 0)
 246                 err(1, "getloadavg() failed");
 247         return (avenrun[2]);
 248 }
 249
 250 /*
 251  * users --
 252  *      return current number of users
 253  *      todo: check idle time; if idle more than X minutes, don't
 254  *      count them.
 255  */
 256 int
 257 users()
 258 {
 259         static struct utmpentry *ohead = NULL;
 260         struct utmpentry *ep;
 261         int nusers;
 262
 263         nusers = getutentries(NULL, &ep);
 264         if (ep != ohead) {
 265                 freeutentries(ep);
 266                 ohead = ep;
 267         }
 268         return nusers;
 269 }
 270
 271 void
 272 nogamefile()
 273 {
 274         int fd, n;
 275         char buf[BUFSIZ];
 276
 277         if ((fd = open(_PATH_NOGAMES, O_RDONLY, 0)) >= 0) {
 278 #define MESG    "Sorry, no games right now.\n\n"
 279                 (void)write(2, MESG, sizeof(MESG) - 1);
 280                 while ((n = read(fd, buf, sizeof(buf))) > 0)
 281                         (void)write(2, buf, n);
 282                 exit(1);
 283         }
 284 }
 285
 286 /*
 287  * hour --
 288  *      print out the hour in human form
 289  */
 290 const char *
 291 hour(h)
 292         int h;
 293 {
 294         static const char *const hours[] = {
 295             "midnight", "1am", "2am", "3am", "4am", "5am",
 296             "6am", "7am", "8am", "9am", "10am", "11am",
 297             "noon", "1pm", "2pm", "3pm", "4pm", "5pm",
 298             "6pm", "7pm", "8pm", "9pm", "10pm", "11pm", "midnight" };
 299
 300         if (h < 0 || h > 24)
 301                 return ("BAD TIME");
 302         else
 303                 return (hours[h]);
 304 }
 305
 306 #ifdef LOG
 307 /*
 308  * logfile --
 309  *      log play of game
 310  */
 311 logfile()
 312 {
 313         struct passwd *pw;
 314         FILE *lp;
 315         uid_t uid;
 316         int lock_cnt;
 317
 318         if (lp = fopen(_PATH_LOG, "a")) {
 319                 for (lock_cnt = 0;; ++lock_cnt) {
 320                         if (!flock(fileno(lp), LOCK_EX))
 321                                 break;
 322                         if (lock_cnt == 4) {
 323                                 warnx("log lock");
 324                                 (void)fclose(lp);
 325                                 return;
 326                         }
 327                         sleep((u_int)1);
 328                 }
 329                 if (pw = getpwuid(uid = getuid()))
 330                         fputs(pw->pw_name, lp);
 331                 else
 332                         fprintf(lp, "%u", uid);
 333                 fprintf(lp, "\t%s\t%s\t%s", game, gametty, ctime(&now));
 334                 (void)fclose(lp);
 335                 (void)flock(fileno(lp), LOCK_UN);
 336         }
 337 }
 338 #endif /* LOG */