Commit | Line | Data |
---|---|---|
2f1de3dd | 1 | /* update-game-score.c --- Update a score file |
294981c7 | 2 | |
73b0cd50 | 3 | Copyright (C) 2002-2011 |
294981c7 GM |
4 | Free Software Foundation, Inc. |
5 | ||
6 | Author: Colin Walters <walters@debian.org> | |
2f1de3dd CW |
7 | |
8 | This file is part of GNU Emacs. | |
9 | ||
294981c7 | 10 | GNU Emacs is free software: you can redistribute it and/or modify |
2f1de3dd | 11 | it under the terms of the GNU General Public License as published by |
294981c7 GM |
12 | the Free Software Foundation, either version 3 of the License, or |
13 | (at your option) any later version. | |
2f1de3dd CW |
14 | |
15 | GNU Emacs is distributed in the hope that it will be useful, | |
16 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | GNU General Public License for more details. | |
19 | ||
20 | You should have received a copy of the GNU General Public License | |
294981c7 GM |
21 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
22 | ||
2f1de3dd | 23 | |
89cc1591 | 24 | /* This program allows a game to securely and atomically update a |
8eec804f CW |
25 | score file. It should be installed setuid, owned by an appropriate |
26 | user like `games'. | |
27 | ||
28 | Alternatively, it can be compiled without HAVE_SHARED_GAME_DIR | |
29 | defined, and in that case it will store scores in the user's home | |
30 | directory (it should NOT be setuid). | |
2f1de3dd | 31 | |
294981c7 | 32 | Created 2002/03/22. |
2f1de3dd CW |
33 | */ |
34 | ||
c42d6dbd EZ |
35 | #include <config.h> |
36 | ||
2f1de3dd CW |
37 | #include <unistd.h> |
38 | #include <errno.h> | |
5b400482 | 39 | #ifdef HAVE_STRING_H |
2f1de3dd | 40 | #include <string.h> |
5b400482 DL |
41 | #endif |
42 | #ifdef HAVE_STDLIB_H | |
2f1de3dd | 43 | #include <stdlib.h> |
5b400482 | 44 | #endif |
2f1de3dd CW |
45 | #include <stdio.h> |
46 | #include <time.h> | |
cd553ffb | 47 | #include <pwd.h> |
2f1de3dd | 48 | #include <ctype.h> |
5b400482 | 49 | #ifdef HAVE_FCNTL_H |
2f1de3dd | 50 | #include <fcntl.h> |
5b400482 DL |
51 | #endif |
52 | #ifdef STDC_HEADERS | |
8eec804f | 53 | #include <stdarg.h> |
5b400482 | 54 | #endif |
2f1de3dd | 55 | #include <sys/stat.h> |
2f1de3dd | 56 | |
5b400482 DL |
57 | /* Needed for SunOS4, for instance. */ |
58 | extern char *optarg; | |
59 | extern int optind, opterr; | |
60 | ||
68441b90 DN |
61 | int usage (int err) NO_RETURN; |
62 | ||
2f1de3dd | 63 | #define MAX_ATTEMPTS 5 |
8eec804f CW |
64 | #define MAX_SCORES 200 |
65 | #define MAX_DATA_LEN 1024 | |
5795b420 | 66 | |
1d28afaf DL |
67 | #ifndef HAVE_DIFFTIME |
68 | /* OK on POSIX (time_t is arithmetic type) modulo overflow in subtraction. */ | |
69 | #define difftime(t1, t0) (double)((t1) - (t0)) | |
70 | #endif | |
71 | ||
2f1de3dd | 72 | int |
873fbd0b | 73 | usage (int err) |
2f1de3dd | 74 | { |
a5d107f3 RS |
75 | fprintf (stdout, "Usage: update-game-score [-m MAX ] [ -r ] game/scorefile SCORE DATA\n"); |
76 | fprintf (stdout, " update-game-score -h\n"); | |
77 | fprintf (stdout, " -h\t\tDisplay this help.\n"); | |
78 | fprintf (stdout, " -m MAX\t\tLimit the maximum number of scores to MAX.\n"); | |
79 | fprintf (stdout, " -r\t\tSort the scores in increasing order.\n"); | |
80 | fprintf (stdout, " -d DIR\t\tStore scores in DIR (only if not setuid).\n"); | |
81 | exit (err); | |
2f1de3dd CW |
82 | } |
83 | ||
f57e2426 J |
84 | int lock_file (const char *filename, void **state); |
85 | int unlock_file (const char *filename, void *state); | |
2f1de3dd CW |
86 | |
87 | struct score_entry | |
88 | { | |
89 | long score; | |
cd553ffb | 90 | char *username; |
2f1de3dd CW |
91 | char *data; |
92 | }; | |
93 | ||
f57e2426 J |
94 | int read_scores (const char *filename, struct score_entry **scores, |
95 | int *count); | |
96 | int push_score (struct score_entry **scores, int *count, | |
97 | int newscore, char *username, char *newdata); | |
98 | void sort_scores (struct score_entry *scores, int count, int reverse); | |
99 | int write_scores (const char *filename, const struct score_entry *scores, | |
100 | int count); | |
cf398788 | 101 | |
f57e2426 | 102 | void lose (const char *msg) NO_RETURN; |
cf398788 | 103 | |
a5d107f3 | 104 | void |
873fbd0b | 105 | lose (const char *msg) |
cf398788 | 106 | { |
a5d107f3 | 107 | fprintf (stderr, "%s\n", msg); |
65396510 | 108 | exit (EXIT_FAILURE); |
cf398788 | 109 | } |
2f1de3dd | 110 | |
f57e2426 | 111 | void lose_syserr (const char *msg) NO_RETURN; |
d99fabf0 | 112 | |
1d28afaf DL |
113 | /* Taken from sysdep.c. */ |
114 | #ifndef HAVE_STRERROR | |
115 | #ifndef WINDOWSNT | |
116 | char * | |
117 | strerror (errnum) | |
118 | int errnum; | |
119 | { | |
120 | extern char *sys_errlist[]; | |
121 | extern int sys_nerr; | |
122 | ||
123 | if (errnum >= 0 && errnum < sys_nerr) | |
124 | return sys_errlist[errnum]; | |
125 | return (char *) "Unknown error"; | |
126 | } | |
127 | #endif /* not WINDOWSNT */ | |
128 | #endif /* ! HAVE_STRERROR */ | |
129 | ||
a5d107f3 | 130 | void |
873fbd0b | 131 | lose_syserr (const char *msg) |
d99fabf0 | 132 | { |
a5d107f3 | 133 | fprintf (stderr, "%s: %s\n", msg, strerror (errno)); |
65396510 | 134 | exit (EXIT_FAILURE); |
d99fabf0 CW |
135 | } |
136 | ||
cd553ffb | 137 | char * |
f57e2426 | 138 | get_user_id (void) |
cd553ffb CW |
139 | { |
140 | char *name; | |
a5d107f3 | 141 | struct passwd *buf = getpwuid (getuid ()); |
cd553ffb CW |
142 | if (!buf) |
143 | { | |
144 | int count = 1; | |
a5d107f3 | 145 | int uid = (int) getuid (); |
8eec804f CW |
146 | int tuid = uid; |
147 | while (tuid /= 10) | |
cd553ffb | 148 | count++; |
a5d107f3 | 149 | name = malloc (count+1); |
d99fabf0 CW |
150 | if (!name) |
151 | return NULL; | |
a5d107f3 | 152 | sprintf (name, "%d", uid); |
cd553ffb CW |
153 | return name; |
154 | } | |
155 | return buf->pw_name; | |
156 | } | |
157 | ||
988e88ab J |
158 | const char * |
159 | get_prefix (int running_suid, const char *user_prefix) | |
8eec804f | 160 | { |
d99fabf0 | 161 | if (!running_suid && user_prefix == NULL) |
a5d107f3 | 162 | lose ("Not using a shared game directory, and no prefix given."); |
d99fabf0 CW |
163 | if (running_suid) |
164 | { | |
165 | #ifdef HAVE_SHARED_GAME_DIR | |
166 | return HAVE_SHARED_GAME_DIR; | |
167 | #else | |
a5d107f3 | 168 | lose ("This program was compiled without HAVE_SHARED_GAME_DIR,\n and should not be suid."); |
d99fabf0 CW |
169 | #endif |
170 | } | |
171 | return user_prefix; | |
8eec804f CW |
172 | } |
173 | ||
2f1de3dd | 174 | int |
873fbd0b | 175 | main (int argc, char **argv) |
2f1de3dd | 176 | { |
d99fabf0 | 177 | int c, running_suid; |
2f1de3dd | 178 | void *lockstate; |
988e88ab J |
179 | char *user_id, *scorefile; |
180 | const char *prefix, *user_prefix = NULL; | |
2f1de3dd CW |
181 | struct stat buf; |
182 | struct score_entry *scores; | |
8eec804f | 183 | int newscore, scorecount, reverse = 0, max = MAX_SCORES; |
2f1de3dd CW |
184 | char *newdata; |
185 | ||
a5d107f3 | 186 | srand (time (0)); |
2f1de3dd | 187 | |
a5d107f3 | 188 | while ((c = getopt (argc, argv, "hrm:d:")) != -1) |
2f1de3dd CW |
189 | switch (c) |
190 | { | |
191 | case 'h': | |
65396510 | 192 | usage (EXIT_SUCCESS); |
2f1de3dd | 193 | break; |
d99fabf0 CW |
194 | case 'd': |
195 | user_prefix = optarg; | |
196 | break; | |
2f1de3dd CW |
197 | case 'r': |
198 | reverse = 1; | |
199 | break; | |
200 | case 'm': | |
a5d107f3 | 201 | max = atoi (optarg); |
8eec804f CW |
202 | if (max > MAX_SCORES) |
203 | max = MAX_SCORES; | |
2f1de3dd CW |
204 | break; |
205 | default: | |
65396510 | 206 | usage (EXIT_FAILURE); |
2f1de3dd CW |
207 | } |
208 | ||
209 | if (optind+3 != argc) | |
65396510 | 210 | usage (EXIT_FAILURE); |
5795b420 | 211 | |
a5d107f3 | 212 | running_suid = (getuid () != geteuid ()); |
5795b420 | 213 | |
a5d107f3 | 214 | prefix = get_prefix (running_suid, user_prefix); |
8eec804f | 215 | |
a5d107f3 | 216 | scorefile = malloc (strlen (prefix) + strlen (argv[optind]) + 2); |
2f1de3dd | 217 | if (!scorefile) |
a5d107f3 | 218 | lose_syserr ("Couldn't allocate score file"); |
8eec804f | 219 | |
a5d107f3 RS |
220 | strcpy (scorefile, prefix); |
221 | strcat (scorefile, "/"); | |
222 | strcat (scorefile, argv[optind]); | |
223 | newscore = atoi (argv[optind+1]); | |
2f1de3dd | 224 | newdata = argv[optind+2]; |
a5d107f3 | 225 | if (strlen (newdata) > MAX_DATA_LEN) |
8eec804f | 226 | newdata[MAX_DATA_LEN] = '\0'; |
d99fabf0 | 227 | |
00a7e408 RS |
228 | user_id = get_user_id (); |
229 | if (user_id == NULL) | |
a5d107f3 | 230 | lose_syserr ("Couldn't determine user id"); |
177c0ea7 | 231 | |
a5d107f3 RS |
232 | if (stat (scorefile, &buf) < 0) |
233 | lose_syserr ("Failed to access scores file"); | |
177c0ea7 | 234 | |
a5d107f3 RS |
235 | if (lock_file (scorefile, &lockstate) < 0) |
236 | lose_syserr ("Failed to lock scores file"); | |
177c0ea7 | 237 | |
a5d107f3 | 238 | if (read_scores (scorefile, &scores, &scorecount) < 0) |
2f1de3dd | 239 | { |
a5d107f3 RS |
240 | unlock_file (scorefile, lockstate); |
241 | lose_syserr ("Failed to read scores file"); | |
2f1de3dd | 242 | } |
a5d107f3 | 243 | push_score (&scores, &scorecount, newscore, user_id, newdata); |
24e9e996 | 244 | sort_scores (scores, scorecount, reverse); |
8eec804f CW |
245 | /* Limit the number of scores. If we're using reverse sorting, then |
246 | we should increment the beginning of the array, to skip over the | |
247 | *smallest* scores. Otherwise, we just decrement the number of | |
248 | scores, since the smallest will be at the end. */ | |
249 | if (scorecount > MAX_SCORES) | |
250 | scorecount -= (scorecount - MAX_SCORES); | |
24e9e996 SM |
251 | if (reverse) |
252 | scores += (scorecount - MAX_SCORES); | |
a5d107f3 | 253 | if (write_scores (scorefile, scores, scorecount) < 0) |
2f1de3dd | 254 | { |
a5d107f3 RS |
255 | unlock_file (scorefile, lockstate); |
256 | lose_syserr ("Failed to write scores file"); | |
2f1de3dd | 257 | } |
a5d107f3 | 258 | unlock_file (scorefile, lockstate); |
65396510 | 259 | exit (EXIT_SUCCESS); |
2f1de3dd CW |
260 | } |
261 | ||
262 | int | |
873fbd0b | 263 | read_score (FILE *f, struct score_entry *score) |
2f1de3dd CW |
264 | { |
265 | int c; | |
a5d107f3 | 266 | if (feof (f)) |
2f1de3dd | 267 | return 1; |
a5d107f3 RS |
268 | while ((c = getc (f)) != EOF |
269 | && isdigit (c)) | |
cd553ffb CW |
270 | { |
271 | score->score *= 10; | |
272 | score->score += (c-48); | |
273 | } | |
a5d107f3 RS |
274 | while ((c = getc (f)) != EOF |
275 | && isspace (c)) | |
cd553ffb CW |
276 | ; |
277 | if (c == EOF) | |
278 | return -1; | |
a5d107f3 | 279 | ungetc (c, f); |
cd553ffb CW |
280 | #ifdef HAVE_GETDELIM |
281 | { | |
7605f1bd | 282 | size_t count = 0; |
a5d107f3 | 283 | if (getdelim (&score->username, &count, ' ', f) < 1 |
cd553ffb CW |
284 | || score->username == NULL) |
285 | return -1; | |
1d4328ff | 286 | /* Trim the space */ |
a5d107f3 | 287 | score->username[strlen (score->username)-1] = '\0'; |
2f1de3dd | 288 | } |
cd553ffb CW |
289 | #else |
290 | { | |
291 | int unameread = 0; | |
292 | int unamelen = 30; | |
a5d107f3 | 293 | char *username = malloc (unamelen); |
f5bceaf8 CW |
294 | if (!username) |
295 | return -1; | |
177c0ea7 | 296 | |
a5d107f3 RS |
297 | while ((c = getc (f)) != EOF |
298 | && !isspace (c)) | |
cd553ffb | 299 | { |
8eec804f | 300 | if (unameread >= unamelen-1) |
a5d107f3 | 301 | if (!(username = realloc (username, unamelen *= 2))) |
8eec804f | 302 | return -1; |
cd553ffb CW |
303 | username[unameread] = c; |
304 | unameread++; | |
305 | } | |
177c0ea7 | 306 | if (c == EOF) |
f5bceaf8 CW |
307 | return -1; |
308 | username[unameread] = '\0'; | |
cd553ffb CW |
309 | score->username = username; |
310 | } | |
311 | #endif | |
2f1de3dd CW |
312 | #ifdef HAVE_GETLINE |
313 | score->data = NULL; | |
7605f1bd | 314 | errno = 0; |
2f1de3dd | 315 | { |
7605f1bd | 316 | size_t len; |
a5d107f3 | 317 | if (getline (&score->data, &len, f) < 0) |
2f1de3dd | 318 | return -1; |
a5d107f3 | 319 | score->data[strlen (score->data)-1] = '\0'; |
2f1de3dd CW |
320 | } |
321 | #else | |
cd553ffb CW |
322 | { |
323 | int cur = 0; | |
324 | int len = 16; | |
a5d107f3 | 325 | char *buf = malloc (len); |
cd553ffb CW |
326 | if (!buf) |
327 | return -1; | |
a5d107f3 | 328 | while ((c = getc (f)) != EOF |
f5bceaf8 | 329 | && c != '\n') |
cd553ffb CW |
330 | { |
331 | if (cur >= len-1) | |
332 | { | |
a5d107f3 | 333 | if (!(buf = realloc (buf, len *= 2))) |
cd553ffb CW |
334 | return -1; |
335 | } | |
336 | buf[cur] = c; | |
337 | cur++; | |
338 | } | |
339 | score->data = buf; | |
5795b420 | 340 | score->data[cur] = '\0'; |
cd553ffb | 341 | } |
2f1de3dd | 342 | #endif |
2f1de3dd CW |
343 | return 0; |
344 | } | |
345 | ||
346 | int | |
873fbd0b | 347 | read_scores (const char *filename, struct score_entry **scores, int *count) |
2f1de3dd CW |
348 | { |
349 | int readval, scorecount, cursize; | |
350 | struct score_entry *ret; | |
a5d107f3 | 351 | FILE *f = fopen (filename, "r"); |
177c0ea7 | 352 | if (!f) |
2f1de3dd CW |
353 | return -1; |
354 | scorecount = 0; | |
355 | cursize = 16; | |
00a7e408 | 356 | ret = (struct score_entry *) malloc (sizeof (struct score_entry) * cursize); |
177c0ea7 | 357 | if (!ret) |
2f1de3dd | 358 | return -1; |
a5d107f3 | 359 | while ((readval = read_score (f, &ret[scorecount])) == 0) |
2f1de3dd CW |
360 | { |
361 | /* We encoutered an error */ | |
362 | if (readval < 0) | |
363 | return -1; | |
364 | scorecount++; | |
365 | if (scorecount >= cursize) | |
366 | { | |
ee435bae JB |
367 | cursize *= 2; |
368 | ret = (struct score_entry *) | |
369 | realloc (ret, (sizeof (struct score_entry) * cursize)); | |
2f1de3dd CW |
370 | if (!ret) |
371 | return -1; | |
372 | } | |
373 | } | |
374 | *count = scorecount; | |
375 | *scores = ret; | |
376 | return 0; | |
377 | } | |
378 | ||
379 | int | |
873fbd0b | 380 | score_compare (const void *a, const void *b) |
2f1de3dd CW |
381 | { |
382 | const struct score_entry *sa = (const struct score_entry *) a; | |
383 | const struct score_entry *sb = (const struct score_entry *) b; | |
384 | return (sb->score > sa->score) - (sb->score < sa->score); | |
385 | } | |
386 | ||
387 | int | |
873fbd0b | 388 | score_compare_reverse (const void *a, const void *b) |
2f1de3dd CW |
389 | { |
390 | const struct score_entry *sa = (const struct score_entry *) a; | |
391 | const struct score_entry *sb = (const struct score_entry *) b; | |
392 | return (sa->score > sb->score) - (sa->score < sb->score); | |
393 | } | |
394 | ||
395 | int | |
873fbd0b | 396 | push_score (struct score_entry **scores, int *count, int newscore, char *username, char *newdata) |
2f1de3dd | 397 | { |
a5d107f3 | 398 | struct score_entry *newscores |
00a7e408 RS |
399 | = (struct score_entry *) realloc (*scores, |
400 | sizeof (struct score_entry) * ((*count) + 1)); | |
2f1de3dd CW |
401 | if (!newscores) |
402 | return -1; | |
403 | newscores[*count].score = newscore; | |
cd553ffb | 404 | newscores[*count].username = username; |
2f1de3dd CW |
405 | newscores[*count].data = newdata; |
406 | (*count) += 1; | |
407 | *scores = newscores; | |
408 | return 0; | |
409 | } | |
177c0ea7 | 410 | |
2f1de3dd | 411 | void |
873fbd0b | 412 | sort_scores (struct score_entry *scores, int count, int reverse) |
2f1de3dd | 413 | { |
a5d107f3 | 414 | qsort (scores, count, sizeof (struct score_entry), |
2f1de3dd CW |
415 | reverse ? score_compare_reverse : score_compare); |
416 | } | |
417 | ||
418 | int | |
873fbd0b | 419 | write_scores (const char *filename, const struct score_entry *scores, int count) |
2f1de3dd | 420 | { |
177c0ea7 | 421 | FILE *f; |
2f1de3dd | 422 | int i; |
a5d107f3 | 423 | char *tempfile = malloc (strlen (filename) + strlen (".tempXXXXXX") + 1); |
2f1de3dd CW |
424 | if (!tempfile) |
425 | return -1; | |
a5d107f3 RS |
426 | strcpy (tempfile, filename); |
427 | strcat (tempfile, ".tempXXXXXX"); | |
8eec804f | 428 | #ifdef HAVE_MKSTEMP |
a5d107f3 | 429 | if (mkstemp (tempfile) < 0 |
8eec804f | 430 | #else |
a5d107f3 | 431 | if (mktemp (tempfile) != tempfile |
8eec804f | 432 | #endif |
a5d107f3 | 433 | || !(f = fopen (tempfile, "w"))) |
2f1de3dd CW |
434 | return -1; |
435 | for (i = 0; i < count; i++) | |
a5d107f3 | 436 | if (fprintf (f, "%ld %s %s\n", scores[i].score, scores[i].username, |
cd553ffb | 437 | scores[i].data) < 0) |
2f1de3dd | 438 | return -1; |
a5d107f3 RS |
439 | fclose (f); |
440 | if (rename (tempfile, filename) < 0) | |
2f1de3dd | 441 | return -1; |
a5d107f3 | 442 | if (chmod (filename, 0644) < 0) |
2f1de3dd | 443 | return -1; |
8eec804f | 444 | return 0; |
2f1de3dd | 445 | } |
177c0ea7 | 446 | |
2f1de3dd | 447 | int |
873fbd0b | 448 | lock_file (const char *filename, void **state) |
2f1de3dd CW |
449 | { |
450 | int fd; | |
7c4f6873 | 451 | struct stat buf; |
2f1de3dd | 452 | int attempts = 0; |
988e88ab | 453 | const char *lockext = ".lockfile"; |
a5d107f3 | 454 | char *lockpath = malloc (strlen (filename) + strlen (lockext) + 60); |
2f1de3dd CW |
455 | if (!lockpath) |
456 | return -1; | |
a5d107f3 RS |
457 | strcpy (lockpath, filename); |
458 | strcat (lockpath, lockext); | |
2f1de3dd CW |
459 | *state = lockpath; |
460 | trylock: | |
461 | attempts++; | |
7c4f6873 | 462 | /* If the lock is over an hour old, delete it. */ |
a5d107f3 RS |
463 | if (stat (lockpath, &buf) == 0 |
464 | && (difftime (buf.st_ctime, time (NULL) > 60*60))) | |
465 | unlink (lockpath); | |
00a7e408 RS |
466 | fd = open (lockpath, O_CREAT | O_EXCL, 0600); |
467 | if (fd < 0) | |
2f1de3dd CW |
468 | { |
469 | if (errno == EEXIST) | |
470 | { | |
471 | /* Break the lock; we won't corrupt the file, but we might | |
472 | lose some scores. */ | |
473 | if (attempts > MAX_ATTEMPTS) | |
7c4f6873 | 474 | { |
a5d107f3 | 475 | unlink (lockpath); |
7c4f6873 CW |
476 | attempts = 0; |
477 | } | |
a5d107f3 | 478 | sleep ((rand () % 2)+1); |
2f1de3dd CW |
479 | goto trylock; |
480 | } | |
481 | else | |
482 | return -1; | |
483 | } | |
a5d107f3 | 484 | close (fd); |
2f1de3dd CW |
485 | return 0; |
486 | } | |
177c0ea7 | 487 | |
2f1de3dd | 488 | int |
873fbd0b | 489 | unlock_file (const char *filename, void *state) |
2f1de3dd CW |
490 | { |
491 | char *lockpath = (char *) state; | |
a5d107f3 | 492 | int ret = unlink (lockpath); |
2f1de3dd | 493 | int saved_errno = errno; |
a5d107f3 | 494 | free (lockpath); |
2f1de3dd CW |
495 | errno = saved_errno; |
496 | return ret; | |
497 | } | |
ab5796a9 | 498 | |
65396510 TTN |
499 | |
500 | /* update-game-score.c ends here */ |