Commit | Line | Data |
---|---|---|
2f1de3dd | 1 | /* update-game-score.c --- Update a score file |
294981c7 | 2 | |
95df8112 | 3 | Copyright (C) 2002-2011 Free Software Foundation, Inc. |
294981c7 GM |
4 | |
5 | Author: Colin Walters <walters@debian.org> | |
2f1de3dd CW |
6 | |
7 | This file is part of GNU Emacs. | |
8 | ||
294981c7 | 9 | GNU Emacs is free software: you can redistribute it and/or modify |
2f1de3dd | 10 | it under the terms of the GNU General Public License as published by |
294981c7 GM |
11 | the Free Software Foundation, either version 3 of the License, or |
12 | (at your option) any later version. | |
2f1de3dd CW |
13 | |
14 | GNU Emacs is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
294981c7 GM |
20 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
21 | ||
2f1de3dd | 22 | |
89cc1591 | 23 | /* This program allows a game to securely and atomically update a |
8eec804f CW |
24 | score file. It should be installed setuid, owned by an appropriate |
25 | user like `games'. | |
26 | ||
27 | Alternatively, it can be compiled without HAVE_SHARED_GAME_DIR | |
28 | defined, and in that case it will store scores in the user's home | |
29 | directory (it should NOT be setuid). | |
2f1de3dd | 30 | |
294981c7 | 31 | Created 2002/03/22. |
2f1de3dd CW |
32 | */ |
33 | ||
c42d6dbd EZ |
34 | #include <config.h> |
35 | ||
2f1de3dd CW |
36 | #include <unistd.h> |
37 | #include <errno.h> | |
0c6d656d | 38 | #include <limits.h> |
2f1de3dd CW |
39 | #include <string.h> |
40 | #include <stdlib.h> | |
41 | #include <stdio.h> | |
42 | #include <time.h> | |
cd553ffb | 43 | #include <pwd.h> |
2f1de3dd | 44 | #include <ctype.h> |
5b400482 | 45 | #ifdef HAVE_FCNTL_H |
2f1de3dd | 46 | #include <fcntl.h> |
5b400482 | 47 | #endif |
2f1de3dd | 48 | #include <sys/stat.h> |
2f1de3dd | 49 | |
5b400482 DL |
50 | /* Needed for SunOS4, for instance. */ |
51 | extern char *optarg; | |
52 | extern int optind, opterr; | |
53 | ||
b23b5a5b | 54 | static int usage (int err) NO_RETURN; |
68441b90 | 55 | |
2f1de3dd | 56 | #define MAX_ATTEMPTS 5 |
8eec804f CW |
57 | #define MAX_SCORES 200 |
58 | #define MAX_DATA_LEN 1024 | |
5795b420 | 59 | |
1d28afaf DL |
60 | #ifndef HAVE_DIFFTIME |
61 | /* OK on POSIX (time_t is arithmetic type) modulo overflow in subtraction. */ | |
62 | #define difftime(t1, t0) (double)((t1) - (t0)) | |
63 | #endif | |
64 | ||
b23b5a5b | 65 | static int |
873fbd0b | 66 | usage (int err) |
2f1de3dd | 67 | { |
ec3b5374 | 68 | fprintf (stdout, "Usage: update-game-score [-m MAX] [-r] [-d DIR] game/scorefile SCORE DATA\n"); |
a5d107f3 RS |
69 | fprintf (stdout, " update-game-score -h\n"); |
70 | fprintf (stdout, " -h\t\tDisplay this help.\n"); | |
71 | fprintf (stdout, " -m MAX\t\tLimit the maximum number of scores to MAX.\n"); | |
72 | fprintf (stdout, " -r\t\tSort the scores in increasing order.\n"); | |
73 | fprintf (stdout, " -d DIR\t\tStore scores in DIR (only if not setuid).\n"); | |
74 | exit (err); | |
2f1de3dd CW |
75 | } |
76 | ||
b23b5a5b PE |
77 | static int lock_file (const char *filename, void **state); |
78 | static int unlock_file (const char *filename, void *state); | |
2f1de3dd CW |
79 | |
80 | struct score_entry | |
81 | { | |
82 | long score; | |
cd553ffb | 83 | char *username; |
2f1de3dd CW |
84 | char *data; |
85 | }; | |
86 | ||
b23b5a5b PE |
87 | static int read_scores (const char *filename, struct score_entry **scores, |
88 | int *count); | |
89 | static int push_score (struct score_entry **scores, int *count, | |
90 | int newscore, char *username, char *newdata); | |
91 | static void sort_scores (struct score_entry *scores, int count, int reverse); | |
92 | static int write_scores (const char *filename, | |
93 | const struct score_entry *scores, int count); | |
cf398788 | 94 | |
b23b5a5b | 95 | static void lose (const char *msg) NO_RETURN; |
cf398788 | 96 | |
b23b5a5b | 97 | static void |
873fbd0b | 98 | lose (const char *msg) |
cf398788 | 99 | { |
a5d107f3 | 100 | fprintf (stderr, "%s\n", msg); |
65396510 | 101 | exit (EXIT_FAILURE); |
cf398788 | 102 | } |
2f1de3dd | 103 | |
b23b5a5b | 104 | static void lose_syserr (const char *msg) NO_RETURN; |
d99fabf0 | 105 | |
1d28afaf DL |
106 | /* Taken from sysdep.c. */ |
107 | #ifndef HAVE_STRERROR | |
108 | #ifndef WINDOWSNT | |
109 | char * | |
ec3b5374 | 110 | strerror (int errnum) |
1d28afaf DL |
111 | { |
112 | extern char *sys_errlist[]; | |
113 | extern int sys_nerr; | |
114 | ||
115 | if (errnum >= 0 && errnum < sys_nerr) | |
116 | return sys_errlist[errnum]; | |
117 | return (char *) "Unknown error"; | |
118 | } | |
119 | #endif /* not WINDOWSNT */ | |
120 | #endif /* ! HAVE_STRERROR */ | |
121 | ||
b23b5a5b | 122 | static void |
873fbd0b | 123 | lose_syserr (const char *msg) |
d99fabf0 | 124 | { |
a5d107f3 | 125 | fprintf (stderr, "%s: %s\n", msg, strerror (errno)); |
65396510 | 126 | exit (EXIT_FAILURE); |
d99fabf0 CW |
127 | } |
128 | ||
b23b5a5b | 129 | static char * |
f57e2426 | 130 | get_user_id (void) |
cd553ffb | 131 | { |
a5d107f3 | 132 | struct passwd *buf = getpwuid (getuid ()); |
cd553ffb CW |
133 | if (!buf) |
134 | { | |
0c6d656d PE |
135 | long uid = getuid (); |
136 | char *name = malloc (sizeof uid * CHAR_BIT / 3 + 1); | |
137 | if (name) | |
138 | sprintf (name, "%ld", uid); | |
cd553ffb CW |
139 | return name; |
140 | } | |
141 | return buf->pw_name; | |
142 | } | |
143 | ||
b23b5a5b | 144 | static const char * |
988e88ab | 145 | get_prefix (int running_suid, const char *user_prefix) |
8eec804f | 146 | { |
d99fabf0 | 147 | if (!running_suid && user_prefix == NULL) |
a5d107f3 | 148 | lose ("Not using a shared game directory, and no prefix given."); |
d99fabf0 CW |
149 | if (running_suid) |
150 | { | |
151 | #ifdef HAVE_SHARED_GAME_DIR | |
152 | return HAVE_SHARED_GAME_DIR; | |
153 | #else | |
a5d107f3 | 154 | lose ("This program was compiled without HAVE_SHARED_GAME_DIR,\n and should not be suid."); |
d99fabf0 CW |
155 | #endif |
156 | } | |
157 | return user_prefix; | |
8eec804f CW |
158 | } |
159 | ||
2f1de3dd | 160 | int |
873fbd0b | 161 | main (int argc, char **argv) |
2f1de3dd | 162 | { |
d99fabf0 | 163 | int c, running_suid; |
2f1de3dd | 164 | void *lockstate; |
988e88ab J |
165 | char *user_id, *scorefile; |
166 | const char *prefix, *user_prefix = NULL; | |
2f1de3dd CW |
167 | struct stat buf; |
168 | struct score_entry *scores; | |
8eec804f | 169 | int newscore, scorecount, reverse = 0, max = MAX_SCORES; |
2f1de3dd CW |
170 | char *newdata; |
171 | ||
a5d107f3 | 172 | srand (time (0)); |
2f1de3dd | 173 | |
a5d107f3 | 174 | while ((c = getopt (argc, argv, "hrm:d:")) != -1) |
2f1de3dd CW |
175 | switch (c) |
176 | { | |
177 | case 'h': | |
65396510 | 178 | usage (EXIT_SUCCESS); |
2f1de3dd | 179 | break; |
d99fabf0 CW |
180 | case 'd': |
181 | user_prefix = optarg; | |
182 | break; | |
2f1de3dd CW |
183 | case 'r': |
184 | reverse = 1; | |
185 | break; | |
186 | case 'm': | |
a5d107f3 | 187 | max = atoi (optarg); |
8eec804f CW |
188 | if (max > MAX_SCORES) |
189 | max = MAX_SCORES; | |
2f1de3dd CW |
190 | break; |
191 | default: | |
65396510 | 192 | usage (EXIT_FAILURE); |
2f1de3dd CW |
193 | } |
194 | ||
195 | if (optind+3 != argc) | |
65396510 | 196 | usage (EXIT_FAILURE); |
5795b420 | 197 | |
a5d107f3 | 198 | running_suid = (getuid () != geteuid ()); |
5795b420 | 199 | |
a5d107f3 | 200 | prefix = get_prefix (running_suid, user_prefix); |
8eec804f | 201 | |
a5d107f3 | 202 | scorefile = malloc (strlen (prefix) + strlen (argv[optind]) + 2); |
2f1de3dd | 203 | if (!scorefile) |
a5d107f3 | 204 | lose_syserr ("Couldn't allocate score file"); |
8eec804f | 205 | |
a5d107f3 RS |
206 | strcpy (scorefile, prefix); |
207 | strcat (scorefile, "/"); | |
208 | strcat (scorefile, argv[optind]); | |
209 | newscore = atoi (argv[optind+1]); | |
2f1de3dd | 210 | newdata = argv[optind+2]; |
a5d107f3 | 211 | if (strlen (newdata) > MAX_DATA_LEN) |
8eec804f | 212 | newdata[MAX_DATA_LEN] = '\0'; |
d99fabf0 | 213 | |
00a7e408 RS |
214 | user_id = get_user_id (); |
215 | if (user_id == NULL) | |
a5d107f3 | 216 | lose_syserr ("Couldn't determine user id"); |
177c0ea7 | 217 | |
a5d107f3 RS |
218 | if (stat (scorefile, &buf) < 0) |
219 | lose_syserr ("Failed to access scores file"); | |
177c0ea7 | 220 | |
a5d107f3 RS |
221 | if (lock_file (scorefile, &lockstate) < 0) |
222 | lose_syserr ("Failed to lock scores file"); | |
177c0ea7 | 223 | |
a5d107f3 | 224 | if (read_scores (scorefile, &scores, &scorecount) < 0) |
2f1de3dd | 225 | { |
a5d107f3 RS |
226 | unlock_file (scorefile, lockstate); |
227 | lose_syserr ("Failed to read scores file"); | |
2f1de3dd | 228 | } |
a5d107f3 | 229 | push_score (&scores, &scorecount, newscore, user_id, newdata); |
24e9e996 | 230 | sort_scores (scores, scorecount, reverse); |
8eec804f | 231 | /* Limit the number of scores. If we're using reverse sorting, then |
f0d80d43 PE |
232 | also increment the beginning of the array, to skip over the |
233 | *smallest* scores. Otherwise, just decrementing the number of | |
234 | scores suffices, since the smallest is at the end. */ | |
8eec804f | 235 | if (scorecount > MAX_SCORES) |
f0d80d43 PE |
236 | { |
237 | if (reverse) | |
238 | scores += (scorecount - MAX_SCORES); | |
239 | scorecount = MAX_SCORES; | |
240 | } | |
a5d107f3 | 241 | if (write_scores (scorefile, scores, scorecount) < 0) |
2f1de3dd | 242 | { |
a5d107f3 RS |
243 | unlock_file (scorefile, lockstate); |
244 | lose_syserr ("Failed to write scores file"); | |
2f1de3dd | 245 | } |
a5d107f3 | 246 | unlock_file (scorefile, lockstate); |
65396510 | 247 | exit (EXIT_SUCCESS); |
2f1de3dd CW |
248 | } |
249 | ||
b23b5a5b | 250 | static int |
873fbd0b | 251 | read_score (FILE *f, struct score_entry *score) |
2f1de3dd CW |
252 | { |
253 | int c; | |
a5d107f3 | 254 | if (feof (f)) |
2f1de3dd | 255 | return 1; |
a5d107f3 RS |
256 | while ((c = getc (f)) != EOF |
257 | && isdigit (c)) | |
cd553ffb CW |
258 | { |
259 | score->score *= 10; | |
260 | score->score += (c-48); | |
261 | } | |
a5d107f3 RS |
262 | while ((c = getc (f)) != EOF |
263 | && isspace (c)) | |
cd553ffb CW |
264 | ; |
265 | if (c == EOF) | |
266 | return -1; | |
a5d107f3 | 267 | ungetc (c, f); |
cd553ffb CW |
268 | #ifdef HAVE_GETDELIM |
269 | { | |
7605f1bd | 270 | size_t count = 0; |
a5d107f3 | 271 | if (getdelim (&score->username, &count, ' ', f) < 1 |
cd553ffb CW |
272 | || score->username == NULL) |
273 | return -1; | |
1d4328ff | 274 | /* Trim the space */ |
a5d107f3 | 275 | score->username[strlen (score->username)-1] = '\0'; |
2f1de3dd | 276 | } |
cd553ffb CW |
277 | #else |
278 | { | |
279 | int unameread = 0; | |
280 | int unamelen = 30; | |
a5d107f3 | 281 | char *username = malloc (unamelen); |
f5bceaf8 CW |
282 | if (!username) |
283 | return -1; | |
177c0ea7 | 284 | |
a5d107f3 RS |
285 | while ((c = getc (f)) != EOF |
286 | && !isspace (c)) | |
cd553ffb | 287 | { |
8eec804f | 288 | if (unameread >= unamelen-1) |
a5d107f3 | 289 | if (!(username = realloc (username, unamelen *= 2))) |
8eec804f | 290 | return -1; |
cd553ffb CW |
291 | username[unameread] = c; |
292 | unameread++; | |
293 | } | |
177c0ea7 | 294 | if (c == EOF) |
f5bceaf8 CW |
295 | return -1; |
296 | username[unameread] = '\0'; | |
cd553ffb CW |
297 | score->username = username; |
298 | } | |
299 | #endif | |
2f1de3dd CW |
300 | #ifdef HAVE_GETLINE |
301 | score->data = NULL; | |
7605f1bd | 302 | errno = 0; |
2f1de3dd | 303 | { |
7605f1bd | 304 | size_t len; |
a5d107f3 | 305 | if (getline (&score->data, &len, f) < 0) |
2f1de3dd | 306 | return -1; |
a5d107f3 | 307 | score->data[strlen (score->data)-1] = '\0'; |
2f1de3dd CW |
308 | } |
309 | #else | |
cd553ffb CW |
310 | { |
311 | int cur = 0; | |
312 | int len = 16; | |
a5d107f3 | 313 | char *buf = malloc (len); |
cd553ffb CW |
314 | if (!buf) |
315 | return -1; | |
a5d107f3 | 316 | while ((c = getc (f)) != EOF |
f5bceaf8 | 317 | && c != '\n') |
cd553ffb CW |
318 | { |
319 | if (cur >= len-1) | |
320 | { | |
a5d107f3 | 321 | if (!(buf = realloc (buf, len *= 2))) |
cd553ffb CW |
322 | return -1; |
323 | } | |
324 | buf[cur] = c; | |
325 | cur++; | |
326 | } | |
327 | score->data = buf; | |
5795b420 | 328 | score->data[cur] = '\0'; |
cd553ffb | 329 | } |
2f1de3dd | 330 | #endif |
2f1de3dd CW |
331 | return 0; |
332 | } | |
333 | ||
b23b5a5b | 334 | static int |
873fbd0b | 335 | read_scores (const char *filename, struct score_entry **scores, int *count) |
2f1de3dd CW |
336 | { |
337 | int readval, scorecount, cursize; | |
338 | struct score_entry *ret; | |
a5d107f3 | 339 | FILE *f = fopen (filename, "r"); |
177c0ea7 | 340 | if (!f) |
2f1de3dd CW |
341 | return -1; |
342 | scorecount = 0; | |
343 | cursize = 16; | |
00a7e408 | 344 | ret = (struct score_entry *) malloc (sizeof (struct score_entry) * cursize); |
177c0ea7 | 345 | if (!ret) |
2f1de3dd | 346 | return -1; |
a5d107f3 | 347 | while ((readval = read_score (f, &ret[scorecount])) == 0) |
2f1de3dd CW |
348 | { |
349 | /* We encoutered an error */ | |
350 | if (readval < 0) | |
351 | return -1; | |
352 | scorecount++; | |
353 | if (scorecount >= cursize) | |
354 | { | |
ee435bae JB |
355 | cursize *= 2; |
356 | ret = (struct score_entry *) | |
357 | realloc (ret, (sizeof (struct score_entry) * cursize)); | |
2f1de3dd CW |
358 | if (!ret) |
359 | return -1; | |
360 | } | |
361 | } | |
362 | *count = scorecount; | |
363 | *scores = ret; | |
364 | return 0; | |
365 | } | |
366 | ||
b23b5a5b | 367 | static int |
873fbd0b | 368 | score_compare (const void *a, const void *b) |
2f1de3dd CW |
369 | { |
370 | const struct score_entry *sa = (const struct score_entry *) a; | |
371 | const struct score_entry *sb = (const struct score_entry *) b; | |
372 | return (sb->score > sa->score) - (sb->score < sa->score); | |
373 | } | |
374 | ||
b23b5a5b | 375 | static int |
873fbd0b | 376 | score_compare_reverse (const void *a, const void *b) |
2f1de3dd CW |
377 | { |
378 | const struct score_entry *sa = (const struct score_entry *) a; | |
379 | const struct score_entry *sb = (const struct score_entry *) b; | |
380 | return (sa->score > sb->score) - (sa->score < sb->score); | |
381 | } | |
382 | ||
383 | int | |
873fbd0b | 384 | push_score (struct score_entry **scores, int *count, int newscore, char *username, char *newdata) |
2f1de3dd | 385 | { |
a5d107f3 | 386 | struct score_entry *newscores |
00a7e408 RS |
387 | = (struct score_entry *) realloc (*scores, |
388 | sizeof (struct score_entry) * ((*count) + 1)); | |
2f1de3dd CW |
389 | if (!newscores) |
390 | return -1; | |
391 | newscores[*count].score = newscore; | |
cd553ffb | 392 | newscores[*count].username = username; |
2f1de3dd CW |
393 | newscores[*count].data = newdata; |
394 | (*count) += 1; | |
395 | *scores = newscores; | |
396 | return 0; | |
397 | } | |
177c0ea7 | 398 | |
b23b5a5b | 399 | static void |
873fbd0b | 400 | sort_scores (struct score_entry *scores, int count, int reverse) |
2f1de3dd | 401 | { |
a5d107f3 | 402 | qsort (scores, count, sizeof (struct score_entry), |
2f1de3dd CW |
403 | reverse ? score_compare_reverse : score_compare); |
404 | } | |
405 | ||
b23b5a5b | 406 | static int |
873fbd0b | 407 | write_scores (const char *filename, const struct score_entry *scores, int count) |
2f1de3dd | 408 | { |
177c0ea7 | 409 | FILE *f; |
2f1de3dd | 410 | int i; |
a5d107f3 | 411 | char *tempfile = malloc (strlen (filename) + strlen (".tempXXXXXX") + 1); |
2f1de3dd CW |
412 | if (!tempfile) |
413 | return -1; | |
a5d107f3 RS |
414 | strcpy (tempfile, filename); |
415 | strcat (tempfile, ".tempXXXXXX"); | |
8eec804f | 416 | #ifdef HAVE_MKSTEMP |
a5d107f3 | 417 | if (mkstemp (tempfile) < 0 |
8eec804f | 418 | #else |
a5d107f3 | 419 | if (mktemp (tempfile) != tempfile |
8eec804f | 420 | #endif |
a5d107f3 | 421 | || !(f = fopen (tempfile, "w"))) |
2f1de3dd CW |
422 | return -1; |
423 | for (i = 0; i < count; i++) | |
a5d107f3 | 424 | if (fprintf (f, "%ld %s %s\n", scores[i].score, scores[i].username, |
cd553ffb | 425 | scores[i].data) < 0) |
2f1de3dd | 426 | return -1; |
a5d107f3 RS |
427 | fclose (f); |
428 | if (rename (tempfile, filename) < 0) | |
2f1de3dd | 429 | return -1; |
a5d107f3 | 430 | if (chmod (filename, 0644) < 0) |
2f1de3dd | 431 | return -1; |
8eec804f | 432 | return 0; |
2f1de3dd | 433 | } |
177c0ea7 | 434 | |
b23b5a5b | 435 | static int |
873fbd0b | 436 | lock_file (const char *filename, void **state) |
2f1de3dd CW |
437 | { |
438 | int fd; | |
7c4f6873 | 439 | struct stat buf; |
2f1de3dd | 440 | int attempts = 0; |
988e88ab | 441 | const char *lockext = ".lockfile"; |
a5d107f3 | 442 | char *lockpath = malloc (strlen (filename) + strlen (lockext) + 60); |
2f1de3dd CW |
443 | if (!lockpath) |
444 | return -1; | |
a5d107f3 RS |
445 | strcpy (lockpath, filename); |
446 | strcat (lockpath, lockext); | |
2f1de3dd CW |
447 | *state = lockpath; |
448 | trylock: | |
449 | attempts++; | |
7c4f6873 | 450 | /* If the lock is over an hour old, delete it. */ |
a5d107f3 RS |
451 | if (stat (lockpath, &buf) == 0 |
452 | && (difftime (buf.st_ctime, time (NULL) > 60*60))) | |
453 | unlink (lockpath); | |
00a7e408 RS |
454 | fd = open (lockpath, O_CREAT | O_EXCL, 0600); |
455 | if (fd < 0) | |
2f1de3dd CW |
456 | { |
457 | if (errno == EEXIST) | |
458 | { | |
459 | /* Break the lock; we won't corrupt the file, but we might | |
460 | lose some scores. */ | |
461 | if (attempts > MAX_ATTEMPTS) | |
7c4f6873 | 462 | { |
a5d107f3 | 463 | unlink (lockpath); |
7c4f6873 CW |
464 | attempts = 0; |
465 | } | |
a5d107f3 | 466 | sleep ((rand () % 2)+1); |
2f1de3dd CW |
467 | goto trylock; |
468 | } | |
469 | else | |
470 | return -1; | |
471 | } | |
a5d107f3 | 472 | close (fd); |
2f1de3dd CW |
473 | return 0; |
474 | } | |
177c0ea7 | 475 | |
b23b5a5b | 476 | static int |
873fbd0b | 477 | unlock_file (const char *filename, void *state) |
2f1de3dd CW |
478 | { |
479 | char *lockpath = (char *) state; | |
a5d107f3 | 480 | int ret = unlink (lockpath); |
2f1de3dd | 481 | int saved_errno = errno; |
a5d107f3 | 482 | free (lockpath); |
2f1de3dd CW |
483 | errno = saved_errno; |
484 | return ret; | |
485 | } | |
ab5796a9 | 486 | |
65396510 TTN |
487 | |
488 | /* update-game-score.c ends here */ |