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> | |
5b400482 | 38 | #ifdef HAVE_STRING_H |
2f1de3dd | 39 | #include <string.h> |
5b400482 DL |
40 | #endif |
41 | #ifdef HAVE_STDLIB_H | |
2f1de3dd | 42 | #include <stdlib.h> |
5b400482 | 43 | #endif |
2f1de3dd CW |
44 | #include <stdio.h> |
45 | #include <time.h> | |
cd553ffb | 46 | #include <pwd.h> |
2f1de3dd | 47 | #include <ctype.h> |
5b400482 | 48 | #ifdef HAVE_FCNTL_H |
2f1de3dd | 49 | #include <fcntl.h> |
5b400482 DL |
50 | #endif |
51 | #ifdef STDC_HEADERS | |
8eec804f | 52 | #include <stdarg.h> |
5b400482 | 53 | #endif |
2f1de3dd | 54 | #include <sys/stat.h> |
2f1de3dd | 55 | |
5b400482 DL |
56 | /* Needed for SunOS4, for instance. */ |
57 | extern char *optarg; | |
58 | extern int optind, opterr; | |
59 | ||
b23b5a5b | 60 | static int usage (int err) NO_RETURN; |
68441b90 | 61 | |
2f1de3dd | 62 | #define MAX_ATTEMPTS 5 |
8eec804f CW |
63 | #define MAX_SCORES 200 |
64 | #define MAX_DATA_LEN 1024 | |
5795b420 | 65 | |
1d28afaf DL |
66 | #ifndef HAVE_DIFFTIME |
67 | /* OK on POSIX (time_t is arithmetic type) modulo overflow in subtraction. */ | |
68 | #define difftime(t1, t0) (double)((t1) - (t0)) | |
69 | #endif | |
70 | ||
b23b5a5b | 71 | static int |
873fbd0b | 72 | usage (int err) |
2f1de3dd | 73 | { |
a5d107f3 RS |
74 | fprintf (stdout, "Usage: update-game-score [-m MAX ] [ -r ] game/scorefile SCORE DATA\n"); |
75 | fprintf (stdout, " update-game-score -h\n"); | |
76 | fprintf (stdout, " -h\t\tDisplay this help.\n"); | |
77 | fprintf (stdout, " -m MAX\t\tLimit the maximum number of scores to MAX.\n"); | |
78 | fprintf (stdout, " -r\t\tSort the scores in increasing order.\n"); | |
79 | fprintf (stdout, " -d DIR\t\tStore scores in DIR (only if not setuid).\n"); | |
80 | exit (err); | |
2f1de3dd CW |
81 | } |
82 | ||
b23b5a5b PE |
83 | static int lock_file (const char *filename, void **state); |
84 | static int unlock_file (const char *filename, void *state); | |
2f1de3dd CW |
85 | |
86 | struct score_entry | |
87 | { | |
88 | long score; | |
cd553ffb | 89 | char *username; |
2f1de3dd CW |
90 | char *data; |
91 | }; | |
92 | ||
b23b5a5b PE |
93 | static int read_scores (const char *filename, struct score_entry **scores, |
94 | int *count); | |
95 | static int push_score (struct score_entry **scores, int *count, | |
96 | int newscore, char *username, char *newdata); | |
97 | static void sort_scores (struct score_entry *scores, int count, int reverse); | |
98 | static int write_scores (const char *filename, | |
99 | const struct score_entry *scores, int count); | |
cf398788 | 100 | |
b23b5a5b | 101 | static void lose (const char *msg) NO_RETURN; |
cf398788 | 102 | |
b23b5a5b | 103 | static void |
873fbd0b | 104 | lose (const char *msg) |
cf398788 | 105 | { |
a5d107f3 | 106 | fprintf (stderr, "%s\n", msg); |
65396510 | 107 | exit (EXIT_FAILURE); |
cf398788 | 108 | } |
2f1de3dd | 109 | |
b23b5a5b | 110 | static void lose_syserr (const char *msg) NO_RETURN; |
d99fabf0 | 111 | |
1d28afaf DL |
112 | /* Taken from sysdep.c. */ |
113 | #ifndef HAVE_STRERROR | |
114 | #ifndef WINDOWSNT | |
115 | char * | |
116 | strerror (errnum) | |
117 | int errnum; | |
118 | { | |
119 | extern char *sys_errlist[]; | |
120 | extern int sys_nerr; | |
121 | ||
122 | if (errnum >= 0 && errnum < sys_nerr) | |
123 | return sys_errlist[errnum]; | |
124 | return (char *) "Unknown error"; | |
125 | } | |
126 | #endif /* not WINDOWSNT */ | |
127 | #endif /* ! HAVE_STRERROR */ | |
128 | ||
b23b5a5b | 129 | static void |
873fbd0b | 130 | lose_syserr (const char *msg) |
d99fabf0 | 131 | { |
a5d107f3 | 132 | fprintf (stderr, "%s: %s\n", msg, strerror (errno)); |
65396510 | 133 | exit (EXIT_FAILURE); |
d99fabf0 CW |
134 | } |
135 | ||
b23b5a5b | 136 | static char * |
f57e2426 | 137 | get_user_id (void) |
cd553ffb CW |
138 | { |
139 | char *name; | |
a5d107f3 | 140 | struct passwd *buf = getpwuid (getuid ()); |
cd553ffb CW |
141 | if (!buf) |
142 | { | |
143 | int count = 1; | |
a5d107f3 | 144 | int uid = (int) getuid (); |
8eec804f CW |
145 | int tuid = uid; |
146 | while (tuid /= 10) | |
cd553ffb | 147 | count++; |
a5d107f3 | 148 | name = malloc (count+1); |
d99fabf0 CW |
149 | if (!name) |
150 | return NULL; | |
a5d107f3 | 151 | sprintf (name, "%d", uid); |
cd553ffb CW |
152 | return name; |
153 | } | |
154 | return buf->pw_name; | |
155 | } | |
156 | ||
b23b5a5b | 157 | static const char * |
988e88ab | 158 | get_prefix (int running_suid, const char *user_prefix) |
8eec804f | 159 | { |
d99fabf0 | 160 | if (!running_suid && user_prefix == NULL) |
a5d107f3 | 161 | lose ("Not using a shared game directory, and no prefix given."); |
d99fabf0 CW |
162 | if (running_suid) |
163 | { | |
164 | #ifdef HAVE_SHARED_GAME_DIR | |
165 | return HAVE_SHARED_GAME_DIR; | |
166 | #else | |
a5d107f3 | 167 | lose ("This program was compiled without HAVE_SHARED_GAME_DIR,\n and should not be suid."); |
d99fabf0 CW |
168 | #endif |
169 | } | |
170 | return user_prefix; | |
8eec804f CW |
171 | } |
172 | ||
2f1de3dd | 173 | int |
873fbd0b | 174 | main (int argc, char **argv) |
2f1de3dd | 175 | { |
d99fabf0 | 176 | int c, running_suid; |
2f1de3dd | 177 | void *lockstate; |
988e88ab J |
178 | char *user_id, *scorefile; |
179 | const char *prefix, *user_prefix = NULL; | |
2f1de3dd CW |
180 | struct stat buf; |
181 | struct score_entry *scores; | |
8eec804f | 182 | int newscore, scorecount, reverse = 0, max = MAX_SCORES; |
2f1de3dd CW |
183 | char *newdata; |
184 | ||
a5d107f3 | 185 | srand (time (0)); |
2f1de3dd | 186 | |
a5d107f3 | 187 | while ((c = getopt (argc, argv, "hrm:d:")) != -1) |
2f1de3dd CW |
188 | switch (c) |
189 | { | |
190 | case 'h': | |
65396510 | 191 | usage (EXIT_SUCCESS); |
2f1de3dd | 192 | break; |
d99fabf0 CW |
193 | case 'd': |
194 | user_prefix = optarg; | |
195 | break; | |
2f1de3dd CW |
196 | case 'r': |
197 | reverse = 1; | |
198 | break; | |
199 | case 'm': | |
a5d107f3 | 200 | max = atoi (optarg); |
8eec804f CW |
201 | if (max > MAX_SCORES) |
202 | max = MAX_SCORES; | |
2f1de3dd CW |
203 | break; |
204 | default: | |
65396510 | 205 | usage (EXIT_FAILURE); |
2f1de3dd CW |
206 | } |
207 | ||
208 | if (optind+3 != argc) | |
65396510 | 209 | usage (EXIT_FAILURE); |
5795b420 | 210 | |
a5d107f3 | 211 | running_suid = (getuid () != geteuid ()); |
5795b420 | 212 | |
a5d107f3 | 213 | prefix = get_prefix (running_suid, user_prefix); |
8eec804f | 214 | |
a5d107f3 | 215 | scorefile = malloc (strlen (prefix) + strlen (argv[optind]) + 2); |
2f1de3dd | 216 | if (!scorefile) |
a5d107f3 | 217 | lose_syserr ("Couldn't allocate score file"); |
8eec804f | 218 | |
a5d107f3 RS |
219 | strcpy (scorefile, prefix); |
220 | strcat (scorefile, "/"); | |
221 | strcat (scorefile, argv[optind]); | |
222 | newscore = atoi (argv[optind+1]); | |
2f1de3dd | 223 | newdata = argv[optind+2]; |
a5d107f3 | 224 | if (strlen (newdata) > MAX_DATA_LEN) |
8eec804f | 225 | newdata[MAX_DATA_LEN] = '\0'; |
d99fabf0 | 226 | |
00a7e408 RS |
227 | user_id = get_user_id (); |
228 | if (user_id == NULL) | |
a5d107f3 | 229 | lose_syserr ("Couldn't determine user id"); |
177c0ea7 | 230 | |
a5d107f3 RS |
231 | if (stat (scorefile, &buf) < 0) |
232 | lose_syserr ("Failed to access scores file"); | |
177c0ea7 | 233 | |
a5d107f3 RS |
234 | if (lock_file (scorefile, &lockstate) < 0) |
235 | lose_syserr ("Failed to lock scores file"); | |
177c0ea7 | 236 | |
a5d107f3 | 237 | if (read_scores (scorefile, &scores, &scorecount) < 0) |
2f1de3dd | 238 | { |
a5d107f3 RS |
239 | unlock_file (scorefile, lockstate); |
240 | lose_syserr ("Failed to read scores file"); | |
2f1de3dd | 241 | } |
a5d107f3 | 242 | push_score (&scores, &scorecount, newscore, user_id, newdata); |
24e9e996 | 243 | sort_scores (scores, scorecount, reverse); |
8eec804f CW |
244 | /* Limit the number of scores. If we're using reverse sorting, then |
245 | we should increment the beginning of the array, to skip over the | |
246 | *smallest* scores. Otherwise, we just decrement the number of | |
247 | scores, since the smallest will be at the end. */ | |
248 | if (scorecount > MAX_SCORES) | |
249 | scorecount -= (scorecount - MAX_SCORES); | |
24e9e996 SM |
250 | if (reverse) |
251 | scores += (scorecount - MAX_SCORES); | |
a5d107f3 | 252 | if (write_scores (scorefile, scores, scorecount) < 0) |
2f1de3dd | 253 | { |
a5d107f3 RS |
254 | unlock_file (scorefile, lockstate); |
255 | lose_syserr ("Failed to write scores file"); | |
2f1de3dd | 256 | } |
a5d107f3 | 257 | unlock_file (scorefile, lockstate); |
65396510 | 258 | exit (EXIT_SUCCESS); |
2f1de3dd CW |
259 | } |
260 | ||
b23b5a5b | 261 | static int |
873fbd0b | 262 | read_score (FILE *f, struct score_entry *score) |
2f1de3dd CW |
263 | { |
264 | int c; | |
a5d107f3 | 265 | if (feof (f)) |
2f1de3dd | 266 | return 1; |
a5d107f3 RS |
267 | while ((c = getc (f)) != EOF |
268 | && isdigit (c)) | |
cd553ffb CW |
269 | { |
270 | score->score *= 10; | |
271 | score->score += (c-48); | |
272 | } | |
a5d107f3 RS |
273 | while ((c = getc (f)) != EOF |
274 | && isspace (c)) | |
cd553ffb CW |
275 | ; |
276 | if (c == EOF) | |
277 | return -1; | |
a5d107f3 | 278 | ungetc (c, f); |
cd553ffb CW |
279 | #ifdef HAVE_GETDELIM |
280 | { | |
7605f1bd | 281 | size_t count = 0; |
a5d107f3 | 282 | if (getdelim (&score->username, &count, ' ', f) < 1 |
cd553ffb CW |
283 | || score->username == NULL) |
284 | return -1; | |
1d4328ff | 285 | /* Trim the space */ |
a5d107f3 | 286 | score->username[strlen (score->username)-1] = '\0'; |
2f1de3dd | 287 | } |
cd553ffb CW |
288 | #else |
289 | { | |
290 | int unameread = 0; | |
291 | int unamelen = 30; | |
a5d107f3 | 292 | char *username = malloc (unamelen); |
f5bceaf8 CW |
293 | if (!username) |
294 | return -1; | |
177c0ea7 | 295 | |
a5d107f3 RS |
296 | while ((c = getc (f)) != EOF |
297 | && !isspace (c)) | |
cd553ffb | 298 | { |
8eec804f | 299 | if (unameread >= unamelen-1) |
a5d107f3 | 300 | if (!(username = realloc (username, unamelen *= 2))) |
8eec804f | 301 | return -1; |
cd553ffb CW |
302 | username[unameread] = c; |
303 | unameread++; | |
304 | } | |
177c0ea7 | 305 | if (c == EOF) |
f5bceaf8 CW |
306 | return -1; |
307 | username[unameread] = '\0'; | |
cd553ffb CW |
308 | score->username = username; |
309 | } | |
310 | #endif | |
2f1de3dd CW |
311 | #ifdef HAVE_GETLINE |
312 | score->data = NULL; | |
7605f1bd | 313 | errno = 0; |
2f1de3dd | 314 | { |
7605f1bd | 315 | size_t len; |
a5d107f3 | 316 | if (getline (&score->data, &len, f) < 0) |
2f1de3dd | 317 | return -1; |
a5d107f3 | 318 | score->data[strlen (score->data)-1] = '\0'; |
2f1de3dd CW |
319 | } |
320 | #else | |
cd553ffb CW |
321 | { |
322 | int cur = 0; | |
323 | int len = 16; | |
a5d107f3 | 324 | char *buf = malloc (len); |
cd553ffb CW |
325 | if (!buf) |
326 | return -1; | |
a5d107f3 | 327 | while ((c = getc (f)) != EOF |
f5bceaf8 | 328 | && c != '\n') |
cd553ffb CW |
329 | { |
330 | if (cur >= len-1) | |
331 | { | |
a5d107f3 | 332 | if (!(buf = realloc (buf, len *= 2))) |
cd553ffb CW |
333 | return -1; |
334 | } | |
335 | buf[cur] = c; | |
336 | cur++; | |
337 | } | |
338 | score->data = buf; | |
5795b420 | 339 | score->data[cur] = '\0'; |
cd553ffb | 340 | } |
2f1de3dd | 341 | #endif |
2f1de3dd CW |
342 | return 0; |
343 | } | |
344 | ||
b23b5a5b | 345 | static int |
873fbd0b | 346 | read_scores (const char *filename, struct score_entry **scores, int *count) |
2f1de3dd CW |
347 | { |
348 | int readval, scorecount, cursize; | |
349 | struct score_entry *ret; | |
a5d107f3 | 350 | FILE *f = fopen (filename, "r"); |
177c0ea7 | 351 | if (!f) |
2f1de3dd CW |
352 | return -1; |
353 | scorecount = 0; | |
354 | cursize = 16; | |
00a7e408 | 355 | ret = (struct score_entry *) malloc (sizeof (struct score_entry) * cursize); |
177c0ea7 | 356 | if (!ret) |
2f1de3dd | 357 | return -1; |
a5d107f3 | 358 | while ((readval = read_score (f, &ret[scorecount])) == 0) |
2f1de3dd CW |
359 | { |
360 | /* We encoutered an error */ | |
361 | if (readval < 0) | |
362 | return -1; | |
363 | scorecount++; | |
364 | if (scorecount >= cursize) | |
365 | { | |
ee435bae JB |
366 | cursize *= 2; |
367 | ret = (struct score_entry *) | |
368 | realloc (ret, (sizeof (struct score_entry) * cursize)); | |
2f1de3dd CW |
369 | if (!ret) |
370 | return -1; | |
371 | } | |
372 | } | |
373 | *count = scorecount; | |
374 | *scores = ret; | |
375 | return 0; | |
376 | } | |
377 | ||
b23b5a5b | 378 | static int |
873fbd0b | 379 | score_compare (const void *a, const void *b) |
2f1de3dd CW |
380 | { |
381 | const struct score_entry *sa = (const struct score_entry *) a; | |
382 | const struct score_entry *sb = (const struct score_entry *) b; | |
383 | return (sb->score > sa->score) - (sb->score < sa->score); | |
384 | } | |
385 | ||
b23b5a5b | 386 | static int |
873fbd0b | 387 | score_compare_reverse (const void *a, const void *b) |
2f1de3dd CW |
388 | { |
389 | const struct score_entry *sa = (const struct score_entry *) a; | |
390 | const struct score_entry *sb = (const struct score_entry *) b; | |
391 | return (sa->score > sb->score) - (sa->score < sb->score); | |
392 | } | |
393 | ||
394 | int | |
873fbd0b | 395 | push_score (struct score_entry **scores, int *count, int newscore, char *username, char *newdata) |
2f1de3dd | 396 | { |
a5d107f3 | 397 | struct score_entry *newscores |
00a7e408 RS |
398 | = (struct score_entry *) realloc (*scores, |
399 | sizeof (struct score_entry) * ((*count) + 1)); | |
2f1de3dd CW |
400 | if (!newscores) |
401 | return -1; | |
402 | newscores[*count].score = newscore; | |
cd553ffb | 403 | newscores[*count].username = username; |
2f1de3dd CW |
404 | newscores[*count].data = newdata; |
405 | (*count) += 1; | |
406 | *scores = newscores; | |
407 | return 0; | |
408 | } | |
177c0ea7 | 409 | |
b23b5a5b | 410 | static void |
873fbd0b | 411 | sort_scores (struct score_entry *scores, int count, int reverse) |
2f1de3dd | 412 | { |
a5d107f3 | 413 | qsort (scores, count, sizeof (struct score_entry), |
2f1de3dd CW |
414 | reverse ? score_compare_reverse : score_compare); |
415 | } | |
416 | ||
b23b5a5b | 417 | static int |
873fbd0b | 418 | write_scores (const char *filename, const struct score_entry *scores, int count) |
2f1de3dd | 419 | { |
177c0ea7 | 420 | FILE *f; |
2f1de3dd | 421 | int i; |
a5d107f3 | 422 | char *tempfile = malloc (strlen (filename) + strlen (".tempXXXXXX") + 1); |
2f1de3dd CW |
423 | if (!tempfile) |
424 | return -1; | |
a5d107f3 RS |
425 | strcpy (tempfile, filename); |
426 | strcat (tempfile, ".tempXXXXXX"); | |
8eec804f | 427 | #ifdef HAVE_MKSTEMP |
a5d107f3 | 428 | if (mkstemp (tempfile) < 0 |
8eec804f | 429 | #else |
a5d107f3 | 430 | if (mktemp (tempfile) != tempfile |
8eec804f | 431 | #endif |
a5d107f3 | 432 | || !(f = fopen (tempfile, "w"))) |
2f1de3dd CW |
433 | return -1; |
434 | for (i = 0; i < count; i++) | |
a5d107f3 | 435 | if (fprintf (f, "%ld %s %s\n", scores[i].score, scores[i].username, |
cd553ffb | 436 | scores[i].data) < 0) |
2f1de3dd | 437 | return -1; |
a5d107f3 RS |
438 | fclose (f); |
439 | if (rename (tempfile, filename) < 0) | |
2f1de3dd | 440 | return -1; |
a5d107f3 | 441 | if (chmod (filename, 0644) < 0) |
2f1de3dd | 442 | return -1; |
8eec804f | 443 | return 0; |
2f1de3dd | 444 | } |
177c0ea7 | 445 | |
b23b5a5b | 446 | static int |
873fbd0b | 447 | lock_file (const char *filename, void **state) |
2f1de3dd CW |
448 | { |
449 | int fd; | |
7c4f6873 | 450 | struct stat buf; |
2f1de3dd | 451 | int attempts = 0; |
988e88ab | 452 | const char *lockext = ".lockfile"; |
a5d107f3 | 453 | char *lockpath = malloc (strlen (filename) + strlen (lockext) + 60); |
2f1de3dd CW |
454 | if (!lockpath) |
455 | return -1; | |
a5d107f3 RS |
456 | strcpy (lockpath, filename); |
457 | strcat (lockpath, lockext); | |
2f1de3dd CW |
458 | *state = lockpath; |
459 | trylock: | |
460 | attempts++; | |
7c4f6873 | 461 | /* If the lock is over an hour old, delete it. */ |
a5d107f3 RS |
462 | if (stat (lockpath, &buf) == 0 |
463 | && (difftime (buf.st_ctime, time (NULL) > 60*60))) | |
464 | unlink (lockpath); | |
00a7e408 RS |
465 | fd = open (lockpath, O_CREAT | O_EXCL, 0600); |
466 | if (fd < 0) | |
2f1de3dd CW |
467 | { |
468 | if (errno == EEXIST) | |
469 | { | |
470 | /* Break the lock; we won't corrupt the file, but we might | |
471 | lose some scores. */ | |
472 | if (attempts > MAX_ATTEMPTS) | |
7c4f6873 | 473 | { |
a5d107f3 | 474 | unlink (lockpath); |
7c4f6873 CW |
475 | attempts = 0; |
476 | } | |
a5d107f3 | 477 | sleep ((rand () % 2)+1); |
2f1de3dd CW |
478 | goto trylock; |
479 | } | |
480 | else | |
481 | return -1; | |
482 | } | |
a5d107f3 | 483 | close (fd); |
2f1de3dd CW |
484 | return 0; |
485 | } | |
177c0ea7 | 486 | |
b23b5a5b | 487 | static int |
873fbd0b | 488 | unlock_file (const char *filename, void *state) |
2f1de3dd CW |
489 | { |
490 | char *lockpath = (char *) state; | |
a5d107f3 | 491 | int ret = unlink (lockpath); |
2f1de3dd | 492 | int saved_errno = errno; |
a5d107f3 | 493 | free (lockpath); |
2f1de3dd CW |
494 | errno = saved_errno; |
495 | return ret; | |
496 | } | |
ab5796a9 | 497 | |
65396510 TTN |
498 | |
499 | /* update-game-score.c ends here */ |