dm/dm.c

   1 /*      $NetBSD: dm.c,v 1.21 2004/11/05 21:30:32 dsl 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\n\
  35         The Regents of the University of California.  All rights reserved.\n");
  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 1.21 2004/11/05 21:30:32 dsl 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 int     main(int, char *[]);
  75 void    nogamefile(void);
  76 void    play(char **) __attribute__((__noreturn__));
  77 void    read_config(void);
  78 int     users(void);
  79
  80 int
  81 main(argc, argv)
  82         int argc __attribute__((__unused__));
  83         char *argv[];
  84 {
  85         char *cp;
  86
  87         nogamefile();
  88         game = (cp = strrchr(*argv, '/')) ? ++cp : *argv;
  89
  90         if (!strcmp(game, "dm"))
  91                 exit(0);
  92
  93         gametty = ttyname(0);
  94         unsetenv("TZ");
  95         (void)time(&now);
  96         read_config();
  97 #ifdef LOG
  98         logfile();
  99 #endif
 100         play(argv);
 101         /*NOTREACHED*/
 102         return (0);
 103 }
 104
 105 /*
 106  * play --
 107  *      play the game
 108  */
 109 void
 110 play(args)
 111         char **args;
 112 {
 113         char pbuf[MAXPATHLEN];
 114
 115         snprintf(pbuf, sizeof(pbuf), "%s%s", _PATH_HIDE, game);
 116         if (priority > 0)       /* < 0 requires root */
 117                 (void)setpriority(PRIO_PROCESS, 0, priority);
 118         execv(pbuf, args);
 119         err(1, "%s", pbuf);
 120 }
 121
 122 /*
 123  * read_config --
 124  *      read through config file, looking for key words.
 125  */
 126 void
 127 read_config()
 128 {
 129         FILE *cfp;
 130         char lbuf[BUFSIZ], f1[40], f2[40], f3[40], f4[40], f5[40];
 131
 132         if (!(cfp = fopen(_PATH_CONFIG, "r")))
 133                 return;
 134         while (fgets(lbuf, sizeof(lbuf), cfp))
 135                 switch (*lbuf) {
 136                 case 'b':               /* badtty */
 137                         if (sscanf(lbuf, "%s%s", f1, f2) != 2 ||
 138                             strcasecmp(f1, "badtty"))
 139                                 break;
 140                         c_tty(f2);
 141                         break;
 142                 case 'g':               /* game */
 143                         if (sscanf(lbuf, "%s%s%s%s%s",
 144                             f1, f2, f3, f4, f5) != 5 || strcasecmp(f1, "game"))
 145                                 break;
 146                         c_game(f2, f3, f4, f5);
 147                         break;
 148                 case 't':               /* time */
 149                         if (sscanf(lbuf, "%s%s%s%s", f1, f2, f3, f4) != 4 ||
 150                             strcasecmp(f1, "time"))
 151                                 break;
 152                         c_day(f2, f3, f4);
 153                 }
 154         (void)fclose(cfp);
 155 }
 156
 157 /*
 158  * c_day --
 159  *      if day is today, see if okay to play
 160  */
 161 void
 162 c_day(s_day, s_start, s_stop)
 163         const char *s_day, *s_start, *s_stop;
 164 {
 165         static const char *const days[] = {
 166                 "sunday", "monday", "tuesday", "wednesday",
 167                 "thursday", "friday", "saturday",
 168         };
 169         static struct tm *ct;
 170         int start, stop;
 171
 172         if (!ct)
 173                 ct = localtime(&now);
 174         if (strcasecmp(s_day, days[ct->tm_wday]))
 175                 return;
 176         if (!isdigit((unsigned char)*s_start) || !isdigit((unsigned char)*s_stop))
 177                 return;
 178         start = atoi(s_start);
 179         stop = atoi(s_stop);
 180         if (ct->tm_hour >= start && ct->tm_hour < stop) {
 181                 if (start == 0 && stop == 24)
 182                         errx(0, "Sorry, games are not available today.");
 183                 else
 184                         errx(0, "Sorry, games are not available from %s to %s today.",
 185                              hour(start), hour(stop));
 186         }
 187 }
 188
 189 /*
 190  * c_tty --
 191  *      decide if this tty can be used for games.
 192  */
 193 void
 194 c_tty(tty)
 195         const char *tty;
 196 {
 197         static int first = 1;
 198         static char *p_tty;
 199
 200         if (first) {
 201                 p_tty = strrchr(gametty, '/');
 202                 first = 0;
 203         }
 204
 205         if (!strcmp(gametty, tty) || (p_tty && !strcmp(p_tty, tty)))
 206                 errx(1, "Sorry, you may not play games on %s.", gametty);
 207 }
 208
 209 /*
 210  * c_game --
 211  *      see if game can be played now.
 212  */
 213 void
 214 c_game(s_game, s_load, s_users, s_priority)
 215         const char *s_game, *s_load, *s_users, *s_priority;
 216 {
 217         static int found;
 218
 219         if (found)
 220                 return;
 221         if (strcmp(game, s_game) && strcasecmp("default", s_game))
 222                 return;
 223         ++found;
 224         if (isdigit((unsigned char)*s_load) && atoi(s_load) < load())
 225                 errx(0, "Sorry, the load average is too high right now.");
 226         if (isdigit((unsigned char)*s_users) && atoi(s_users) <= users())
 227                 errx(0, "Sorry, there are too many users logged on right now.");
 228         if (isdigit((unsigned char)*s_priority))
 229                 priority = atoi(s_priority);
 230 }
 231
 232 /*
 233  * load --
 234  *      return 15 minute load average
 235  */
 236 double
 237 load()
 238 {
 239         double avenrun[3];
 240
 241         if (getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0])) < 0)
 242                 err(1, "getloadavg() failed");
 243         return (avenrun[2]);
 244 }
 245
 246 /*
 247  * users --
 248  *      return current number of users
 249  *      todo: check idle time; if idle more than X minutes, don't
 250  *      count them.
 251  */
 252 int
 253 users()
 254 {
 255         static struct utmpentry *ohead = NULL;
 256         struct utmpentry *ep;
 257         int nusers;
 258
 259         nusers = getutentries(NULL, &ep);
 260         if (ep != ohead) {
 261                 freeutentries(ep);
 262                 ohead = ep;
 263         }
 264         return nusers;
 265 }
 266
 267 void
 268 nogamefile()
 269 {
 270         int fd, n;
 271         char buf[BUFSIZ];
 272
 273         if ((fd = open(_PATH_NOGAMES, O_RDONLY, 0)) >= 0) {
 274 #define MESG    "Sorry, no games right now.\n\n"
 275                 (void)write(2, MESG, sizeof(MESG) - 1);
 276                 while ((n = read(fd, buf, sizeof(buf))) > 0)
 277                         (void)write(2, buf, n);
 278                 exit(1);
 279         }
 280 }
 281
 282 /*
 283  * hour --
 284  *      print out the hour in human form
 285  */
 286 const char *
 287 hour(h)
 288         int h;
 289 {
 290         static const char *const hours[] = {
 291             "midnight", "1am", "2am", "3am", "4am", "5am",
 292             "6am", "7am", "8am", "9am", "10am", "11am",
 293             "noon", "1pm", "2pm", "3pm", "4pm", "5pm",
 294             "6pm", "7pm", "8pm", "9pm", "10pm", "11pm", "midnight" };
 295
 296         if (h < 0 || h > 24)
 297                 return ("BAD TIME");
 298         else
 299                 return (hours[h]);
 300 }
 301
 302 #ifdef LOG
 303 /*
 304  * logfile --
 305  *      log play of game
 306  */
 307 logfile()
 308 {
 309         struct passwd *pw;
 310         FILE *lp;
 311         uid_t uid;
 312         int lock_cnt;
 313
 314         if (lp = fopen(_PATH_LOG, "a")) {
 315                 for (lock_cnt = 0;; ++lock_cnt) {
 316                         if (!flock(fileno(lp), LOCK_EX))
 317                                 break;
 318                         if (lock_cnt == 4) {
 319                                 warnx("log lock");
 320                                 (void)fclose(lp);
 321                                 return;
 322                         }
 323                         sleep((u_int)1);
 324                 }
 325                 if (pw = getpwuid(uid = getuid()))
 326                         fputs(pw->pw_name, lp);
 327                 else
 328                         fprintf(lp, "%u", uid);
 329                 fprintf(lp, "\t%s\t%s\t%s", game, gametty, ctime(&now));
 330                 (void)fclose(lp);
 331                 (void)flock(fileno(lp), LOCK_UN);
 332         }
 333 }
 334 #endif /* LOG */