author | Lars Hjemli <hjemli@gmail.com> | 2006-12-11 08:57:58 (UTC) |
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committer | Lars Hjemli <hjemli@gmail.com> | 2006-12-11 08:57:58 (UTC) |
commit | f5069d88dff7a7ed2f4665904b03e906cca75a7c (patch) (unidiff) | |
tree | 4c9bfa3aaf931af4a345ffb9563b19825c38b628 | |
parent | 76827d8679d1d2bd46e8cddf7da2ce4178e1d676 (diff) | |
download | cgit-f5069d88dff7a7ed2f4665904b03e906cca75a7c.zip cgit-f5069d88dff7a7ed2f4665904b03e906cca75a7c.tar.gz cgit-f5069d88dff7a7ed2f4665904b03e906cca75a7c.tar.bz2 |
Fix cache algorithm loophole
This closes the door for unneccessary calls to cgit_fill_cache().
Noticed by Linus.
Signed-off-by: Lars Hjemli <hjemli@gmail.com>
-rw-r--r-- | cache.c | 6 | ||||
-rw-r--r-- | cgit.c | 18 | ||||
-rw-r--r-- | cgit.h | 3 |
3 files changed, 16 insertions, 11 deletions
@@ -1,80 +1,84 @@ | |||
1 | /* cache.c: cache management | 1 | /* cache.c: cache management |
2 | * | 2 | * |
3 | * Copyright (C) 2006 Lars Hjemli | 3 | * Copyright (C) 2006 Lars Hjemli |
4 | * | 4 | * |
5 | * Licensed under GNU General Public License v2 | 5 | * Licensed under GNU General Public License v2 |
6 | * (see COPYING for full license text) | 6 | * (see COPYING for full license text) |
7 | */ | 7 | */ |
8 | 8 | ||
9 | #include "cgit.h" | 9 | #include "cgit.h" |
10 | 10 | ||
11 | const int NOLOCK = -1; | 11 | const int NOLOCK = -1; |
12 | 12 | ||
13 | int cache_lookup(struct cacheitem *item) | 13 | void cache_prepare(struct cacheitem *item) |
14 | { | 14 | { |
15 | if (!cgit_query_repo) { | 15 | if (!cgit_query_repo) { |
16 | item->name = xstrdup(fmt("%s/index.html", cgit_cache_root)); | 16 | item->name = xstrdup(fmt("%s/index.html", cgit_cache_root)); |
17 | item->ttl = cgit_cache_root_ttl; | 17 | item->ttl = cgit_cache_root_ttl; |
18 | } else if (!cgit_query_page) { | 18 | } else if (!cgit_query_page) { |
19 | item->name = xstrdup(fmt("%s/%s/index.html", cgit_cache_root, | 19 | item->name = xstrdup(fmt("%s/%s/index.html", cgit_cache_root, |
20 | cgit_query_repo)); | 20 | cgit_query_repo)); |
21 | item->ttl = cgit_cache_repo_ttl; | 21 | item->ttl = cgit_cache_repo_ttl; |
22 | } else { | 22 | } else { |
23 | item->name = xstrdup(fmt("%s/%s/%s/%s.html", cgit_cache_root, | 23 | item->name = xstrdup(fmt("%s/%s/%s/%s.html", cgit_cache_root, |
24 | cgit_query_repo, cgit_query_page, | 24 | cgit_query_repo, cgit_query_page, |
25 | cgit_querystring)); | 25 | cgit_querystring)); |
26 | if (cgit_query_has_symref) | 26 | if (cgit_query_has_symref) |
27 | item->ttl = cgit_cache_dynamic_ttl; | 27 | item->ttl = cgit_cache_dynamic_ttl; |
28 | else if (cgit_query_has_sha1) | 28 | else if (cgit_query_has_sha1) |
29 | item->ttl = cgit_cache_static_ttl; | 29 | item->ttl = cgit_cache_static_ttl; |
30 | else | 30 | else |
31 | item->ttl = cgit_cache_repo_ttl; | 31 | item->ttl = cgit_cache_repo_ttl; |
32 | } | 32 | } |
33 | } | ||
34 | |||
35 | int cache_exist(struct cacheitem *item) | ||
36 | { | ||
33 | if (stat(item->name, &item->st)) { | 37 | if (stat(item->name, &item->st)) { |
34 | item->st.st_mtime = 0; | 38 | item->st.st_mtime = 0; |
35 | return 0; | 39 | return 0; |
36 | } | 40 | } |
37 | return 1; | 41 | return 1; |
38 | } | 42 | } |
39 | 43 | ||
40 | int cache_create_dirs() | 44 | int cache_create_dirs() |
41 | { | 45 | { |
42 | char *path; | 46 | char *path; |
43 | 47 | ||
44 | if (!cgit_query_repo) | 48 | if (!cgit_query_repo) |
45 | return 0; | 49 | return 0; |
46 | 50 | ||
47 | path = fmt("%s/%s", cgit_cache_root, cgit_query_repo); | 51 | path = fmt("%s/%s", cgit_cache_root, cgit_query_repo); |
48 | if (mkdir(path, S_IRWXU) && errno!=EEXIST) | 52 | if (mkdir(path, S_IRWXU) && errno!=EEXIST) |
49 | return 0; | 53 | return 0; |
50 | 54 | ||
51 | if (cgit_query_page) { | 55 | if (cgit_query_page) { |
52 | path = fmt("%s/%s/%s", cgit_cache_root, cgit_query_repo, | 56 | path = fmt("%s/%s/%s", cgit_cache_root, cgit_query_repo, |
53 | cgit_query_page); | 57 | cgit_query_page); |
54 | if (mkdir(path, S_IRWXU) && errno!=EEXIST) | 58 | if (mkdir(path, S_IRWXU) && errno!=EEXIST) |
55 | return 0; | 59 | return 0; |
56 | } | 60 | } |
57 | return 1; | 61 | return 1; |
58 | } | 62 | } |
59 | 63 | ||
60 | int cache_lock(struct cacheitem *item) | 64 | int cache_lock(struct cacheitem *item) |
61 | { | 65 | { |
62 | int ret; | 66 | int ret; |
63 | char *lockfile = fmt("%s.lock", item->name); | 67 | char *lockfile = fmt("%s.lock", item->name); |
64 | 68 | ||
65 | top: | 69 | top: |
66 | item->fd = open(lockfile, O_WRONLY | O_CREAT | O_EXCL, S_IRUSR|S_IWUSR); | 70 | item->fd = open(lockfile, O_WRONLY | O_CREAT | O_EXCL, S_IRUSR|S_IWUSR); |
67 | if (item->fd == NOLOCK && errno == ENOENT && cache_create_dirs()) | 71 | if (item->fd == NOLOCK && errno == ENOENT && cache_create_dirs()) |
68 | goto top; | 72 | goto top; |
69 | if (item->fd == NOLOCK && errno == EEXIST) { | 73 | if (item->fd == NOLOCK && errno == EEXIST) { |
70 | struct stat st; | 74 | struct stat st; |
71 | time_t t; | 75 | time_t t; |
72 | if (stat(lockfile, &st)) | 76 | if (stat(lockfile, &st)) |
73 | return ret; | 77 | return ret; |
74 | t = time(NULL); | 78 | t = time(NULL); |
75 | if (t-st.st_mtime > cgit_cache_max_create_time && | 79 | if (t-st.st_mtime > cgit_cache_max_create_time && |
76 | !unlink(lockfile)) | 80 | !unlink(lockfile)) |
77 | goto top; | 81 | goto top; |
78 | return 0; | 82 | return 0; |
79 | } | 83 | } |
80 | return (item->fd > 0); | 84 | return (item->fd > 0); |
@@ -420,89 +420,89 @@ static void cgit_print_object(char *hex) | |||
420 | } | 420 | } |
421 | 421 | ||
422 | buf[size] = '\0'; | 422 | buf[size] = '\0'; |
423 | html("<h2>Object view</h2>"); | 423 | html("<h2>Object view</h2>"); |
424 | htmlf("sha1=%s<br/>type=%s<br/>size=%i<br/>", hex, type, size); | 424 | htmlf("sha1=%s<br/>type=%s<br/>size=%i<br/>", hex, type, size); |
425 | html("<pre>"); | 425 | html("<pre>"); |
426 | html_txt(buf); | 426 | html_txt(buf); |
427 | html("</pre>"); | 427 | html("</pre>"); |
428 | } | 428 | } |
429 | 429 | ||
430 | static void cgit_print_repo_page() | 430 | static void cgit_print_repo_page() |
431 | { | 431 | { |
432 | if (chdir(fmt("%s/%s", cgit_root, cgit_query_repo)) || | 432 | if (chdir(fmt("%s/%s", cgit_root, cgit_query_repo)) || |
433 | cgit_read_config("info/cgit", cgit_repo_config_cb)) { | 433 | cgit_read_config("info/cgit", cgit_repo_config_cb)) { |
434 | char *title = fmt("%s - %s", cgit_root_title, "Bad request"); | 434 | char *title = fmt("%s - %s", cgit_root_title, "Bad request"); |
435 | cgit_print_docstart(title); | 435 | cgit_print_docstart(title); |
436 | cgit_print_pageheader(title); | 436 | cgit_print_pageheader(title); |
437 | htmlf(cgit_lib_error, "Unable to scan repository", | 437 | htmlf(cgit_lib_error, "Unable to scan repository", |
438 | strerror(errno)); | 438 | strerror(errno)); |
439 | cgit_print_docend(); | 439 | cgit_print_docend(); |
440 | return; | 440 | return; |
441 | } | 441 | } |
442 | setenv("GIT_DIR", fmt("%s/%s", cgit_root, cgit_query_repo), 1); | 442 | setenv("GIT_DIR", fmt("%s/%s", cgit_root, cgit_query_repo), 1); |
443 | char *title = fmt("%s - %s", cgit_repo_name, cgit_repo_desc); | 443 | char *title = fmt("%s - %s", cgit_repo_name, cgit_repo_desc); |
444 | cgit_print_docstart(title); | 444 | cgit_print_docstart(title); |
445 | cgit_print_pageheader(title); | 445 | cgit_print_pageheader(title); |
446 | if (!cgit_query_page) | 446 | if (!cgit_query_page) |
447 | cgit_print_repo_summary(); | 447 | cgit_print_repo_summary(); |
448 | else if (!strcmp(cgit_query_page, "log")) { | 448 | else if (!strcmp(cgit_query_page, "log")) { |
449 | cgit_print_log(cgit_query_head, 0, 100); | 449 | cgit_print_log(cgit_query_head, 0, 100); |
450 | } else if (!strcmp(cgit_query_page, "view")) { | 450 | } else if (!strcmp(cgit_query_page, "view")) { |
451 | cgit_print_object(cgit_query_sha1); | 451 | cgit_print_object(cgit_query_sha1); |
452 | } | 452 | } |
453 | cgit_print_docend(); | 453 | cgit_print_docend(); |
454 | } | 454 | } |
455 | 455 | ||
456 | static void cgit_fill_cache(struct cacheitem *item) | 456 | static void cgit_fill_cache(struct cacheitem *item) |
457 | { | 457 | { |
458 | htmlfd = item->fd; | 458 | htmlfd = item->fd; |
459 | item->st.st_mtime = time(NULL); | 459 | item->st.st_mtime = time(NULL); |
460 | if (cgit_query_repo) | 460 | if (cgit_query_repo) |
461 | cgit_print_repo_page(); | 461 | cgit_print_repo_page(); |
462 | else | 462 | else |
463 | cgit_print_repolist(); | 463 | cgit_print_repolist(); |
464 | } | 464 | } |
465 | 465 | ||
466 | static void cgit_refresh_cache(struct cacheitem *item) | 466 | static void cgit_refresh_cache(struct cacheitem *item) |
467 | { | 467 | { |
468 | cache_prepare(item); | ||
468 | top: | 469 | top: |
469 | if (!cache_lookup(item)) { | 470 | if (!cache_exist(item)) { |
470 | if (cache_lock(item)) { | 471 | if (!cache_lock(item)) { |
471 | cgit_fill_cache(item); | ||
472 | cache_unlock(item); | ||
473 | } else { | ||
474 | sched_yield(); | 472 | sched_yield(); |
475 | goto top; | 473 | goto top; |
476 | } | 474 | } |
477 | } else if (cache_expired(item)) { | 475 | if (!cache_exist(item)) |
478 | if (cache_lock(item)) { | ||
479 | cgit_fill_cache(item); | 476 | cgit_fill_cache(item); |
480 | cache_unlock(item); | 477 | cache_unlock(item); |
481 | } | 478 | } else if (cache_expired(item) && cache_lock(item)) { |
479 | if (cache_expired(item)) | ||
480 | cgit_fill_cache(item); | ||
481 | cache_unlock(item); | ||
482 | } | 482 | } |
483 | } | 483 | } |
484 | 484 | ||
485 | static void cgit_print_cache(struct cacheitem *item) | 485 | static void cgit_print_cache(struct cacheitem *item) |
486 | { | 486 | { |
487 | static char buf[4096]; | 487 | static char buf[4096]; |
488 | ssize_t i; | 488 | ssize_t i; |
489 | 489 | ||
490 | int fd = open(item->name, O_RDONLY); | 490 | int fd = open(item->name, O_RDONLY); |
491 | if (fd<0) | 491 | if (fd<0) |
492 | die("Unable to open cached file %s", item->name); | 492 | die("Unable to open cached file %s", item->name); |
493 | 493 | ||
494 | while((i=read(fd, buf, sizeof(buf))) > 0) | 494 | while((i=read(fd, buf, sizeof(buf))) > 0) |
495 | write(STDOUT_FILENO, buf, i); | 495 | write(STDOUT_FILENO, buf, i); |
496 | 496 | ||
497 | close(fd); | 497 | close(fd); |
498 | } | 498 | } |
499 | 499 | ||
500 | int main(int argc, const char **argv) | 500 | int main(int argc, const char **argv) |
501 | { | 501 | { |
502 | cgit_read_config("/etc/cgitrc", cgit_global_config_cb); | 502 | cgit_read_config("/etc/cgitrc", cgit_global_config_cb); |
503 | cgit_querystring = xstrdup(getenv("QUERY_STRING")); | 503 | cgit_querystring = xstrdup(getenv("QUERY_STRING")); |
504 | cgit_parse_query(cgit_querystring, cgit_querystring_cb); | 504 | cgit_parse_query(cgit_querystring, cgit_querystring_cb); |
505 | cgit_refresh_cache(&cacheitem); | 505 | cgit_refresh_cache(&cacheitem); |
506 | cgit_print_cache(&cacheitem); | 506 | cgit_print_cache(&cacheitem); |
507 | return 0; | 507 | return 0; |
508 | } | 508 | } |
@@ -11,54 +11,55 @@ typedef void (*configfn)(const char *name, const char *value); | |||
11 | struct cacheitem { | 11 | struct cacheitem { |
12 | char *name; | 12 | char *name; |
13 | struct stat st; | 13 | struct stat st; |
14 | int ttl; | 14 | int ttl; |
15 | int fd; | 15 | int fd; |
16 | }; | 16 | }; |
17 | 17 | ||
18 | extern char *cgit_root; | 18 | extern char *cgit_root; |
19 | extern char *cgit_root_title; | 19 | extern char *cgit_root_title; |
20 | extern char *cgit_css; | 20 | extern char *cgit_css; |
21 | extern char *cgit_logo; | 21 | extern char *cgit_logo; |
22 | extern char *cgit_logo_link; | 22 | extern char *cgit_logo_link; |
23 | extern char *cgit_virtual_root; | 23 | extern char *cgit_virtual_root; |
24 | extern char *cgit_cache_root; | 24 | extern char *cgit_cache_root; |
25 | 25 | ||
26 | extern int cgit_cache_root_ttl; | 26 | extern int cgit_cache_root_ttl; |
27 | extern int cgit_cache_repo_ttl; | 27 | extern int cgit_cache_repo_ttl; |
28 | extern int cgit_cache_dynamic_ttl; | 28 | extern int cgit_cache_dynamic_ttl; |
29 | extern int cgit_cache_static_ttl; | 29 | extern int cgit_cache_static_ttl; |
30 | extern int cgit_cache_max_create_time; | 30 | extern int cgit_cache_max_create_time; |
31 | 31 | ||
32 | extern char *cgit_repo_name; | 32 | extern char *cgit_repo_name; |
33 | extern char *cgit_repo_desc; | 33 | extern char *cgit_repo_desc; |
34 | extern char *cgit_repo_owner; | 34 | extern char *cgit_repo_owner; |
35 | 35 | ||
36 | extern int cgit_query_has_symref; | 36 | extern int cgit_query_has_symref; |
37 | extern int cgit_query_has_sha1; | 37 | extern int cgit_query_has_sha1; |
38 | 38 | ||
39 | extern char *cgit_querystring; | 39 | extern char *cgit_querystring; |
40 | extern char *cgit_query_repo; | 40 | extern char *cgit_query_repo; |
41 | extern char *cgit_query_page; | 41 | extern char *cgit_query_page; |
42 | extern char *cgit_query_head; | 42 | extern char *cgit_query_head; |
43 | extern char *cgit_query_sha1; | 43 | extern char *cgit_query_sha1; |
44 | 44 | ||
45 | extern int htmlfd; | 45 | extern int htmlfd; |
46 | 46 | ||
47 | extern char *fmt(const char *format,...); | 47 | extern char *fmt(const char *format,...); |
48 | 48 | ||
49 | extern void html(const char *txt); | 49 | extern void html(const char *txt); |
50 | extern void htmlf(const char *format,...); | 50 | extern void htmlf(const char *format,...); |
51 | extern void html_txt(char *txt); | 51 | extern void html_txt(char *txt); |
52 | extern void html_attr(char *txt); | 52 | extern void html_attr(char *txt); |
53 | extern void html_link_open(char *url, char *title, char *class); | 53 | extern void html_link_open(char *url, char *title, char *class); |
54 | extern void html_link_close(void); | 54 | extern void html_link_close(void); |
55 | 55 | ||
56 | 56 | ||
57 | extern int cgit_read_config(const char *filename, configfn fn); | 57 | extern int cgit_read_config(const char *filename, configfn fn); |
58 | 58 | ||
59 | extern int cache_lookup(struct cacheitem *item); | 59 | extern void cache_prepare(struct cacheitem *item); |
60 | extern int cache_lock(struct cacheitem *item); | 60 | extern int cache_lock(struct cacheitem *item); |
61 | extern int cache_unlock(struct cacheitem *item); | 61 | extern int cache_unlock(struct cacheitem *item); |
62 | extern int cache_exist(struct cacheitem *item); | ||
62 | extern int cache_expired(struct cacheitem *item); | 63 | extern int cache_expired(struct cacheitem *item); |
63 | 64 | ||
64 | #endif /* CGIT_H */ | 65 | #endif /* CGIT_H */ |