dm/dm.c

   1 /*      $NetBSD: dm.c,v 1.26 2008/07/20 01:03:21 lukem 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 1.26 2008/07/20 01:03:21 lukem 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 void    c_day(const char *, const char *, const char *);
  70 void    c_game(const char *, const char  *, const char *, const char *);
  71 void    c_tty(const char *);
  72 const char *hour(int);
  73 double  load(void);
  74 void    nogamefile(void);
  75 void    play(char **) __dead;
  76 void    read_config(void);
  77 int     users(void);
  78
  79 int
  80 main(int argc __unused, char *argv[])
  81 {
  82         char *cp;
  83
  84         nogamefile();
  85         game = (cp = strrchr(*argv, '/')) ? ++cp : *argv;
  86
  87         if (!strcmp(game, "dm"))
  88                 exit(0);
  89
  90         gametty = ttyname(0);
  91         unsetenv("TZ");
  92         (void)time(&now);
  93         read_config();
  94 #ifdef LOG
  95         logfile();
  96 #endif
  97         play(argv);
  98         /*NOTREACHED*/
  99         return (0);
 100 }
 101
 102 /*
 103  * play --
 104  *      play the game
 105  */
 106 void
 107 play(char **args)
 108 {
 109         char pbuf[MAXPATHLEN];
 110
 111         snprintf(pbuf, sizeof(pbuf), "%s%s", _PATH_HIDE, game);
 112         if (priority > 0)       /* < 0 requires root */
 113                 (void)setpriority(PRIO_PROCESS, 0, priority);
 114         execv(pbuf, args);
 115         err(1, "%s", pbuf);
 116 }
 117
 118 /*
 119  * read_config --
 120  *      read through config file, looking for key words.
 121  */
 122 void
 123 read_config(void)
 124 {
 125         FILE *cfp;
 126         char lbuf[BUFSIZ], f1[40], f2[40], f3[40], f4[40], f5[40];
 127
 128         if (!(cfp = fopen(_PATH_CONFIG, "r")))
 129                 return;
 130         while (fgets(lbuf, sizeof(lbuf), cfp))
 131                 switch (*lbuf) {
 132                 case 'b':               /* badtty */
 133                         if (sscanf(lbuf, "%39s%39s", f1, f2) != 2 ||
 134                             strcasecmp(f1, "badtty"))
 135                                 break;
 136                         c_tty(f2);
 137                         break;
 138                 case 'g':               /* game */
 139                         if (sscanf(lbuf, "%39s%39s%39s%39s%39s",
 140                             f1, f2, f3, f4, f5) != 5 || strcasecmp(f1, "game"))
 141                                 break;
 142                         c_game(f2, f3, f4, f5);
 143                         break;
 144                 case 't':               /* time */
 145                         if (sscanf(lbuf, "%39s%39s%39s%39s", f1, f2, f3, f4) != 4 ||
 146                             strcasecmp(f1, "time"))
 147                                 break;
 148                         c_day(f2, f3, f4);
 149                 }
 150         (void)fclose(cfp);
 151 }
 152
 153 /*
 154  * c_day --
 155  *      if day is today, see if okay to play
 156  */
 157 void
 158 c_day(const char *s_day, const char *s_start, const char *s_stop)
 159 {
 160         static const char *const days[] = {
 161                 "sunday", "monday", "tuesday", "wednesday",
 162                 "thursday", "friday", "saturday",
 163         };
 164         static struct tm *ct;
 165         int start, stop;
 166
 167         if (!ct)
 168                 ct = localtime(&now);
 169         if (strcasecmp(s_day, days[ct->tm_wday]))
 170                 return;
 171         if (!isdigit((unsigned char)*s_start) ||
 172             !isdigit((unsigned char)*s_stop))
 173                 return;
 174         start = atoi(s_start);
 175         stop = atoi(s_stop);
 176         if (ct->tm_hour >= start && ct->tm_hour < stop) {
 177                 if (start == 0 && stop == 24)
 178                         errx(0, "Sorry, games are not available today.");
 179                 else
 180                         errx(0, "Sorry, games are not available from %s to %s today.",
 181                              hour(start), hour(stop));
 182         }
 183 }
 184
 185 /*
 186  * c_tty --
 187  *      decide if this tty can be used for games.
 188  */
 189 void
 190 c_tty(const char *tty)
 191 {
 192         static int first = 1;
 193         static char *p_tty;
 194
 195         if (first) {
 196                 p_tty = strrchr(gametty, '/');
 197                 first = 0;
 198         }
 199
 200         if (!strcmp(gametty, tty) || (p_tty && !strcmp(p_tty, tty)))
 201                 errx(1, "Sorry, you may not play games on %s.", gametty);
 202 }
 203
 204 /*
 205  * c_game --
 206  *      see if game can be played now.
 207  */
 208 void
 209 c_game(const char *s_game, const char *s_load, const char *s_users,
 210        const 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((unsigned char)*s_load) && atoi(s_load) < load())
 220                 errx(0, "Sorry, the load average is too high right now.");
 221         if (isdigit((unsigned char)*s_users) && atoi(s_users) <= users())
 222                 errx(0, "Sorry, there are too many users logged on right now.");
 223         if (isdigit((unsigned char)*s_priority))
 224                 priority = atoi(s_priority);
 225 }
 226
 227 /*
 228  * load --
 229  *      return 15 minute load average
 230  */
 231 double
 232 load(void)
 233 {
 234         double avenrun[3];
 235
 236         if (getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0])) < 0)
 237                 err(1, "getloadavg() failed");
 238         return (avenrun[2]);
 239 }
 240
 241 /*
 242  * users --
 243  *      return current number of users
 244  *      todo: check idle time; if idle more than X minutes, don't
 245  *      count them.
 246  */
 247 int
 248 users(void)
 249 {
 250         struct utmpentry *ep;
 251         int nusers;
 252
 253         nusers = getutentries(NULL, &ep);
 254         return nusers;
 255 }
 256
 257 void
 258 nogamefile(void)
 259 {
 260         int fd, n;
 261         char buf[BUFSIZ];
 262
 263         if ((fd = open(_PATH_NOGAMES, O_RDONLY, 0)) >= 0) {
 264 #define MESG    "Sorry, no games right now.\n\n"
 265                 (void)write(2, MESG, sizeof(MESG) - 1);
 266                 while ((n = read(fd, buf, sizeof(buf))) > 0)
 267                         (void)write(2, buf, n);
 268                 exit(1);
 269         }
 270 }
 271
 272 /*
 273  * hour --
 274  *      print out the hour in human form
 275  */
 276 const char *
 277 hour(int h)
 278 {
 279         static const char *const hours[] = {
 280             "midnight", "1am", "2am", "3am", "4am", "5am",
 281             "6am", "7am", "8am", "9am", "10am", "11am",
 282             "noon", "1pm", "2pm", "3pm", "4pm", "5pm",
 283             "6pm", "7pm", "8pm", "9pm", "10pm", "11pm", "midnight" };
 284
 285         if (h < 0 || h > 24)
 286                 return ("BAD TIME");
 287         else
 288                 return (hours[h]);
 289 }
 290
 291 #ifdef LOG
 292 /*
 293  * logfile --
 294  *      log play of game
 295  */
 296 logfile(void)
 297 {
 298         struct passwd *pw;
 299         FILE *lp;
 300         uid_t uid;
 301         int lock_cnt;
 302
 303         if (lp = fopen(_PATH_LOG, "a")) {
 304                 for (lock_cnt = 0;; ++lock_cnt) {
 305                         if (!flock(fileno(lp), LOCK_EX))
 306                                 break;
 307                         if (lock_cnt == 4) {
 308                                 warnx("log lock");
 309                                 (void)fclose(lp);
 310                                 return;
 311                         }
 312                         sleep((u_int)1);
 313                 }
 314                 if (pw = getpwuid(uid = getuid()))
 315                         fputs(pw->pw_name, lp);
 316                 else
 317                         fprintf(lp, "%u", uid);
 318                 fprintf(lp, "\t%s\t%s\t%s", game, gametty, ctime(&now));
 319                 (void)fclose(lp);
 320                 (void)flock(fileno(lp), LOCK_UN);
 321         }
 322 }
 323 #endif /* LOG */