Neale Pickett
·
2013-07-18
find.c
1/*
2 * Various installation dependent routines
3 *
4 * @(#)find.c 4.37 (Berkeley) 05/23/83
5 */
6
7/*
8 * The various tuneable defines are:
9 *
10 * SCOREFILE Where/if the score file should live.
11 * ALLSCORES Score file is top ten scores, not top ten
12 * players. This is only useful when only a few
13 * people will be playing; otherwise the score file
14 * gets hogged by just a few people.
15 * NUMSCORES Number of scores in the score file (default 10).
16 * NUMNAME String version of NUMSCORES (first character
17 * should be capitalized) (default "Ten").
18 * MAXLOAD What (if any) the maximum load average should be
19 * when people are playing. Since it is divided
20 * by 10, to specify a load limit of 4.0, MAXLOAD
21 * should be "40". If defined, then
22 * LOADAV Should it use it's own routine to get
23 * the load average?
24 * NAMELIST If so, where does the system namelist
25 * hide?
26 * MAXUSERS What (if any) the maximum user count should be
27 * when people are playing. If defined, then
28 * UCOUNT Should it use it's own routine to count
29 * users?
30 * UTMP If so, where does the user list hide?
31 * CHECKTIME How often/if it should check during the game
32 * for high load average.
33 */
34
35#include <curses.h>
36#include "network.h"
37#include <signal.h>
38#include <sys/types.h>
39#include <sys/stat.h>
40#include <sys/ioctl.h>
41
42#include <fcntl.h>
43
44#ifdef SCOREFILE
45
46static char *Lockfile = "/tmp/.fredlock";
47
48# ifndef NUMSCORES
49# define NUMSCORES 10
50# define NUMNAME "Ten"
51# endif
52
53unsigned int numscores = NUMSCORES;
54char *Numname = NUMNAME;
55
56# ifdef ALLSCORES
57bool Allscore = TRUE;
58# else ALLSCORES
59bool Allscore = FALSE;
60# endif ALLSCORES
61
62#endif SCOREFILE
63
64#ifdef CHECKTIME
65static int Num_checks; /* times we've gone over in checkout() */
66#endif CHECKTIME
67
68/*
69 * init_check:
70 * Check out too see if it is proper to play the game now
71 */
72void
73init_check(void)
74{
75#if defined(MAXLOAD) || defined(MAXUSERS)
76 if (too_much())
77 {
78 printf("Sorry, %s, but the system is too loaded now.\n", Whoami);
79 printf("Try again later. Meanwhile, why not enjoy a%s %s?\n",
80 vowelstr(Fruit), Fruit);
81 if (author())
82 printf("However, since you're a good guy, it's up to you\n");
83 else
84 exit(1);
85 }
86#endif
87}
88
89/*
90 * open_score:
91 * Open up the score file for future use, and then
92 * setuid(getuid()) in case we are running setuid.
93 */
94void
95open_score(void)
96{
97#ifdef SCOREFILE
98 Fd = open(SCOREFILE, O_RDWR);
99#else
100 Fd = -1;
101#endif
102 setuid(getuid());
103 setgid(getgid());
104}
105
106/*
107 * setup:
108 * Get starting setup for all games
109 */
110void
111setup(void)
112{
113#ifdef CHECKTIME
114 int checkout();
115#endif
116
117 signal(SIGHUP, auto_save);
118#ifndef DUMP
119 signal(SIGILL, auto_save);
120 signal(SIGTRAP, auto_save);
121 signal(SIGIOT, auto_save);
122 signal(SIGFPE, auto_save);
123 signal(SIGBUS, auto_save);
124 signal(SIGSEGV, auto_save);
125 signal(SIGSYS, auto_save);
126 signal(SIGTERM, auto_save);
127#endif
128
129 signal(SIGINT, quit);
130#ifndef DUMP
131 signal(SIGQUIT, endit);
132#endif
133#ifdef CHECKTIME
134 signal(SIGALRM, checkout);
135 alarm(CHECKTIME * 60);
136 Num_checks = 0;
137#endif
138 crmode(); /* Cbreak mode */
139 noecho(); /* Echo off */
140#ifdef TIOCGLTC
141 getltchars(); /* get the local tty chars */
142#endif
143}
144
145/*
146 * getltchars:
147 * Get the local tty chars for later use
148 */
149void
150getltchars(void)
151{
152#ifdef TIOCGLTC
153 ioctl(1, TIOCGLTC, &Ltc);
154 Got_ltc = TRUE;
155 Orig_dsusp = Ltc.t_dsuspc;
156 Ltc.t_dsuspc = Ltc.t_suspc;
157 ioctl(1, TIOCSLTC, &Ltc);
158#endif
159}
160
161/*
162 * resetltchars:
163 * Reset the local tty chars to original values.
164 */
165void
166resetltchars(void)
167{
168#ifdef TIOCGLTC
169 if (Got_ltc) {
170 Ltc.t_dsuspc = Orig_dsusp;
171 ioctl(1, TIOCSLTC, &Ltc);
172 }
173#endif
174}
175
176/*
177 * playltchars:
178 * Set local tty chars to the values we use when playing.
179 */
180void
181playltchars(void)
182{
183#ifdef TIOCGLTC
184 if (Got_ltc) {
185 Ltc.t_dsuspc = Ltc.t_suspc;
186 ioctl(1, TIOCSLTC, &Ltc);
187 }
188#endif
189}
190
191/*
192 * start_score:
193 * Start the scoring sequence
194 */
195void
196start_score(void)
197{
198#ifdef CHECKTIME
199 signal(SIGALRM, SIG_IGN);
200#endif
201}
202
203/*
204 * is_symlink:
205 * See if the file has a symbolic link
206 */
207bool
208is_symlink(char *sp)
209{
210#ifdef S_IFLNK
211 struct stat sbuf2;
212
213 if (lstat(sp, &sbuf2) < 0)
214 return FALSE;
215 else
216 return ((sbuf2.st_mode & S_IFMT) != S_IFREG);
217#else
218 return FALSE;
219#endif
220}
221
222#if defined(MAXLOAD) || defined(MAXUSERS)
223/*
224 * too_much:
225 * See if the system is being used too much for this game
226 */
227bool
228too_much(void)
229{
230#ifdef MAXLOAD
231 double avec[3];
232#else
233 int cnt;
234#endif
235
236#ifdef MAXLOAD
237 loadav(avec);
238 if (avec[1] > (MAXLOAD / 10.0))
239 return TRUE;
240#endif
241#ifdef MAXUSERS
242 if (ucount() > MAXUSERS)
243 return TRUE;
244#endif
245 return FALSE;
246}
247
248/*
249 * author:
250 * See if a user is an author of the program
251 */
252bool
253author(void)
254{
255#ifdef MASTER
256 if (Wizard)
257 return TRUE;
258#endif
259 switch (getuid())
260 {
261 case -1:
262 return TRUE;
263 default:
264 return FALSE;
265 }
266}
267#endif
268
269#ifdef CHECKTIME
270/*
271 * checkout:
272 * Check each CHECKTIME seconds to see if the load is too high
273 */
274void
275checkout(int sig)
276{
277 static char *msgs[] = {
278 "The load is too high to be playing. Please leave in %0.1f minutes",
279 "Please save your game. You have %0.1f minutes",
280 "Last warning. You have %0.1f minutes to leave",
281 };
282 int checktime;
283
284 signal(SIGALRM, checkout);
285 if (too_much())
286 {
287 if (author())
288 {
289 Num_checks = 1;
290 chmsg("The load is rather high, O exaulted one");
291 }
292 else if (Num_checks++ == 3)
293 fatal("Sorry. You took too long. You are dead\n");
294 checktime = (CHECKTIME * 60) / Num_checks;
295 alarm(checktime);
296 chmsg(msgs[Num_checks - 1], ((double) checktime / 60.0));
297 }
298 else
299 {
300 if (Num_checks)
301 {
302 Num_checks = 0;
303 chmsg("The load has dropped back down. You have a reprieve");
304 }
305 alarm(CHECKTIME * 60);
306 }
307}
308
309/*
310 * chmsg:
311 * checkout()'s version of msg. If we are in the middle of a
312 * shell, do a printf instead of a msg to avoid the refresh.
313 */
314/* VARARGS1 */
315void
316chmsg(char *fmt, int arg)
317{
318 if (!In_shell)
319 msg(fmt, arg);
320 else
321 {
322 printf(fmt, arg);
323 putchar('\n');
324 fflush(stdout);
325 }
326}
327#endif
328
329#ifdef LOADAV
330/*
331 * loadav:
332 * Looking up load average in core (for system where the loadav()
333 * system call isn't defined
334 */
335
336#include <nlist.h>
337
338struct nlist avenrun = {
339 "_avenrun"
340};
341
342void
343loadav(double *avg)
344{
345 int kmem;
346
347 if ((kmem = open("/dev/kmem", 0)) < 0)
348 goto bad;
349 nlist(NAMELIST, &avenrun);
350 if (avenrun.n_type == 0)
351 {
352 close(kmem);
353bad:
354 avg[0] = 0.0;
355 avg[1] = 0.0;
356 avg[2] = 0.0;
357 return;
358 }
359
360 lseek(kmem, (long) avenrun.n_value, 0);
361 read(kmem, (char *) avg, 3 * sizeof (double));
362 close(kmem);
363}
364#endif
365
366#ifdef UCOUNT
367/*
368 * ucount:
369 * Count number of users on the system
370 */
371#include <utmp.h>
372
373struct utmp buf;
374
375int
376ucount(void)
377{
378 struct utmp *up;
379 FILE *utmp;
380 int count;
381
382 if ((utmp = fopen(UTMP, "r")) == NULL)
383 return 0;
384
385 up = &buf;
386 count = 0;
387
388 while (fread(up, 1, sizeof (*up), utmp) > 0)
389 if (buf.ut_name[0] != '\0')
390 count++;
391 fclose(utmp);
392 return count;
393}
394#endif
395
396/*
397 * lock_sc:
398 * lock the score file. If it takes too long, ask the user if
399 * they care to wait. Return TRUE if the lock is successful.
400 */
401bool
402lock_sc(void)
403{
404#ifdef SCOREFILE
405 int cnt;
406 static struct stat sbuf;
407 time_t time();
408
409over:
410 close(8); /* just in case there are no files left */
411 if (creat(Lockfile, 0000) >= 0)
412 return TRUE;
413 for (cnt = 0; cnt < 5; cnt++)
414 {
415 sleep(1);
416 if (creat(Lockfile, 0000) >= 0)
417 return TRUE;
418 }
419 if (stat(Lockfile, &sbuf) < 0)
420 {
421 creat(Lockfile, 0000);
422 return TRUE;
423 }
424 if (time(NULL) - sbuf.st_mtime > 10)
425 {
426 if (unlink(Lockfile) < 0)
427 return FALSE;
428 goto over;
429 }
430 else
431 {
432 printf("The score file is very busy. Do you want to wait longer\n");
433 printf("for it to become free so your score can get posted?\n");
434 printf("If so, type \"y\"\n");
435 fgets(Prbuf, MAXSTR, stdin);
436 if (Prbuf[0] == 'y')
437 for (;;)
438 {
439 if (creat(Lockfile, 0000) >= 0)
440 return TRUE;
441 if (stat(Lockfile, &sbuf) < 0)
442 {
443 creat(Lockfile, 0000);
444 return TRUE;
445 }
446 if (time(NULL) - sbuf.st_mtime > 10)
447 {
448 if (unlink(Lockfile) < 0)
449 return FALSE;
450 }
451 sleep(1);
452 }
453 else
454 return FALSE;
455 }
456#endif
457}
458
459/*
460 * unlock_sc:
461 * Unlock the score file
462 */
463void
464unlock_sc(void)
465{
466#ifdef SCOREFILE
467 unlink(Lockfile);
468#endif
469}
470
471/*
472 * flush_type:
473 * Flush typeahead for traps, etc.
474 */
475void
476flush_type(void)
477{
478 crmode();
479}