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Commit | Line | Data |
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1 | /* | |
2 | * I'm tired of doing "vsnprintf()" etc just to open a | |
3 | * file, so here's a "return static buffer with printf" | |
4 | * interface for paths. | |
5 | * | |
6 | * It's obviously not thread-safe. Sue me. But it's quite | |
7 | * useful for doing things like | |
8 | * | |
9 | * f = open(mkpath("%s/%s.git", base, name), O_RDONLY); | |
10 | * | |
11 | * which is what it's designed for. | |
12 | */ | |
13 | #include "cache.h" | |
14 | ||
15 | static char bad_path[] = "/bad-path/"; | |
16 | ||
17 | static char *get_pathname(void) | |
18 | { | |
19 | static char pathname_array[4][PATH_MAX]; | |
20 | static int index; | |
21 | return pathname_array[3 & ++index]; | |
22 | } | |
23 | ||
24 | static char *cleanup_path(char *path) | |
25 | { | |
26 | /* Clean it up */ | |
27 | if (!memcmp(path, "./", 2)) { | |
28 | path += 2; | |
29 | while (*path == '/') | |
30 | path++; | |
31 | } | |
32 | return path; | |
33 | } | |
34 | ||
35 | char *mksnpath(char *buf, size_t n, const char *fmt, ...) | |
36 | { | |
37 | va_list args; | |
38 | unsigned len; | |
39 | ||
40 | va_start(args, fmt); | |
41 | len = vsnprintf(buf, n, fmt, args); | |
42 | va_end(args); | |
43 | if (len >= n) { | |
44 | strlcpy(buf, bad_path, n); | |
45 | return buf; | |
46 | } | |
47 | return cleanup_path(buf); | |
48 | } | |
49 | ||
50 | static char *git_vsnpath(char *buf, size_t n, const char *fmt, va_list args) | |
51 | { | |
52 | const char *git_dir = get_git_dir(); | |
53 | size_t len; | |
54 | ||
55 | len = strlen(git_dir); | |
56 | if (n < len + 1) | |
57 | goto bad; | |
58 | memcpy(buf, git_dir, len); | |
59 | if (len && !is_dir_sep(git_dir[len-1])) | |
60 | buf[len++] = '/'; | |
61 | len += vsnprintf(buf + len, n - len, fmt, args); | |
62 | if (len >= n) | |
63 | goto bad; | |
64 | return cleanup_path(buf); | |
65 | bad: | |
66 | strlcpy(buf, bad_path, n); | |
67 | return buf; | |
68 | } | |
69 | ||
70 | char *git_snpath(char *buf, size_t n, const char *fmt, ...) | |
71 | { | |
72 | va_list args; | |
73 | va_start(args, fmt); | |
74 | (void)git_vsnpath(buf, n, fmt, args); | |
75 | va_end(args); | |
76 | return buf; | |
77 | } | |
78 | ||
79 | char *git_pathdup(const char *fmt, ...) | |
80 | { | |
81 | char path[PATH_MAX]; | |
82 | va_list args; | |
83 | va_start(args, fmt); | |
84 | (void)git_vsnpath(path, sizeof(path), fmt, args); | |
85 | va_end(args); | |
86 | return xstrdup(path); | |
87 | } | |
88 | ||
89 | char *mkpath(const char *fmt, ...) | |
90 | { | |
91 | va_list args; | |
92 | unsigned len; | |
93 | char *pathname = get_pathname(); | |
94 | ||
95 | va_start(args, fmt); | |
96 | len = vsnprintf(pathname, PATH_MAX, fmt, args); | |
97 | va_end(args); | |
98 | if (len >= PATH_MAX) | |
99 | return bad_path; | |
100 | return cleanup_path(pathname); | |
101 | } | |
102 | ||
103 | char *git_path(const char *fmt, ...) | |
104 | { | |
105 | const char *git_dir = get_git_dir(); | |
106 | char *pathname = get_pathname(); | |
107 | va_list args; | |
108 | unsigned len; | |
109 | ||
110 | len = strlen(git_dir); | |
111 | if (len > PATH_MAX-100) | |
112 | return bad_path; | |
113 | memcpy(pathname, git_dir, len); | |
114 | if (len && git_dir[len-1] != '/') | |
115 | pathname[len++] = '/'; | |
116 | va_start(args, fmt); | |
117 | len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args); | |
118 | va_end(args); | |
119 | if (len >= PATH_MAX) | |
120 | return bad_path; | |
121 | return cleanup_path(pathname); | |
122 | } | |
123 | ||
124 | ||
125 | /* git_mkstemp() - create tmp file honoring TMPDIR variable */ | |
126 | int git_mkstemp(char *path, size_t len, const char *template) | |
127 | { | |
128 | const char *tmp; | |
129 | size_t n; | |
130 | ||
131 | tmp = getenv("TMPDIR"); | |
132 | if (!tmp) | |
133 | tmp = "/tmp"; | |
134 | n = snprintf(path, len, "%s/%s", tmp, template); | |
135 | if (len <= n) { | |
136 | errno = ENAMETOOLONG; | |
137 | return -1; | |
138 | } | |
139 | return mkstemp(path); | |
140 | } | |
141 | ||
142 | ||
143 | int validate_headref(const char *path) | |
144 | { | |
145 | struct stat st; | |
146 | char *buf, buffer[256]; | |
147 | unsigned char sha1[20]; | |
148 | int fd; | |
149 | ssize_t len; | |
150 | ||
151 | if (lstat(path, &st) < 0) | |
152 | return -1; | |
153 | ||
154 | /* Make sure it is a "refs/.." symlink */ | |
155 | if (S_ISLNK(st.st_mode)) { | |
156 | len = readlink(path, buffer, sizeof(buffer)-1); | |
157 | if (len >= 5 && !memcmp("refs/", buffer, 5)) | |
158 | return 0; | |
159 | return -1; | |
160 | } | |
161 | ||
162 | /* | |
163 | * Anything else, just open it and try to see if it is a symbolic ref. | |
164 | */ | |
165 | fd = open(path, O_RDONLY); | |
166 | if (fd < 0) | |
167 | return -1; | |
168 | len = read_in_full(fd, buffer, sizeof(buffer)-1); | |
169 | close(fd); | |
170 | ||
171 | /* | |
172 | * Is it a symbolic ref? | |
173 | */ | |
174 | if (len < 4) | |
175 | return -1; | |
176 | if (!memcmp("ref:", buffer, 4)) { | |
177 | buf = buffer + 4; | |
178 | len -= 4; | |
179 | while (len && isspace(*buf)) | |
180 | buf++, len--; | |
181 | if (len >= 5 && !memcmp("refs/", buf, 5)) | |
182 | return 0; | |
183 | } | |
184 | ||
185 | /* | |
186 | * Is this a detached HEAD? | |
187 | */ | |
188 | if (!get_sha1_hex(buffer, sha1)) | |
189 | return 0; | |
190 | ||
191 | return -1; | |
192 | } | |
193 | ||
194 | static char *user_path(char *buf, char *path, int sz) | |
195 | { | |
196 | struct passwd *pw; | |
197 | char *slash; | |
198 | int len, baselen; | |
199 | ||
200 | if (!path || path[0] != '~') | |
201 | return NULL; | |
202 | path++; | |
203 | slash = strchr(path, '/'); | |
204 | if (path[0] == '/' || !path[0]) { | |
205 | pw = getpwuid(getuid()); | |
206 | } | |
207 | else { | |
208 | if (slash) { | |
209 | *slash = 0; | |
210 | pw = getpwnam(path); | |
211 | *slash = '/'; | |
212 | } | |
213 | else | |
214 | pw = getpwnam(path); | |
215 | } | |
216 | if (!pw || !pw->pw_dir || sz <= strlen(pw->pw_dir)) | |
217 | return NULL; | |
218 | baselen = strlen(pw->pw_dir); | |
219 | memcpy(buf, pw->pw_dir, baselen); | |
220 | while ((1 < baselen) && (buf[baselen-1] == '/')) { | |
221 | buf[baselen-1] = 0; | |
222 | baselen--; | |
223 | } | |
224 | if (slash && slash[1]) { | |
225 | len = strlen(slash); | |
226 | if (sz <= baselen + len) | |
227 | return NULL; | |
228 | memcpy(buf + baselen, slash, len + 1); | |
229 | } | |
230 | return buf; | |
231 | } | |
232 | ||
233 | /* | |
234 | * First, one directory to try is determined by the following algorithm. | |
235 | * | |
236 | * (0) If "strict" is given, the path is used as given and no DWIM is | |
237 | * done. Otherwise: | |
238 | * (1) "~/path" to mean path under the running user's home directory; | |
239 | * (2) "~user/path" to mean path under named user's home directory; | |
240 | * (3) "relative/path" to mean cwd relative directory; or | |
241 | * (4) "/absolute/path" to mean absolute directory. | |
242 | * | |
243 | * Unless "strict" is given, we try access() for existence of "%s.git/.git", | |
244 | * "%s/.git", "%s.git", "%s" in this order. The first one that exists is | |
245 | * what we try. | |
246 | * | |
247 | * Second, we try chdir() to that. Upon failure, we return NULL. | |
248 | * | |
249 | * Then, we try if the current directory is a valid git repository. | |
250 | * Upon failure, we return NULL. | |
251 | * | |
252 | * If all goes well, we return the directory we used to chdir() (but | |
253 | * before ~user is expanded), avoiding getcwd() resolving symbolic | |
254 | * links. User relative paths are also returned as they are given, | |
255 | * except DWIM suffixing. | |
256 | */ | |
257 | char *enter_repo(char *path, int strict) | |
258 | { | |
259 | static char used_path[PATH_MAX]; | |
260 | static char validated_path[PATH_MAX]; | |
261 | ||
262 | if (!path) | |
263 | return NULL; | |
264 | ||
265 | if (!strict) { | |
266 | static const char *suffix[] = { | |
267 | ".git/.git", "/.git", ".git", "", NULL, | |
268 | }; | |
269 | int len = strlen(path); | |
270 | int i; | |
271 | while ((1 < len) && (path[len-1] == '/')) { | |
272 | path[len-1] = 0; | |
273 | len--; | |
274 | } | |
275 | if (PATH_MAX <= len) | |
276 | return NULL; | |
277 | if (path[0] == '~') { | |
278 | if (!user_path(used_path, path, PATH_MAX)) | |
279 | return NULL; | |
280 | strcpy(validated_path, path); | |
281 | path = used_path; | |
282 | } | |
283 | else if (PATH_MAX - 10 < len) | |
284 | return NULL; | |
285 | else { | |
286 | path = strcpy(used_path, path); | |
287 | strcpy(validated_path, path); | |
288 | } | |
289 | len = strlen(path); | |
290 | for (i = 0; suffix[i]; i++) { | |
291 | strcpy(path + len, suffix[i]); | |
292 | if (!access(path, F_OK)) { | |
293 | strcat(validated_path, suffix[i]); | |
294 | break; | |
295 | } | |
296 | } | |
297 | if (!suffix[i] || chdir(path)) | |
298 | return NULL; | |
299 | path = validated_path; | |
300 | } | |
301 | else if (chdir(path)) | |
302 | return NULL; | |
303 | ||
304 | if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 && | |
305 | validate_headref("HEAD") == 0) { | |
306 | setenv(GIT_DIR_ENVIRONMENT, ".", 1); | |
307 | check_repository_format(); | |
308 | return path; | |
309 | } | |
310 | ||
311 | return NULL; | |
312 | } | |
313 | ||
314 | int adjust_shared_perm(const char *path) | |
315 | { | |
316 | struct stat st; | |
317 | int mode; | |
318 | ||
319 | if (!shared_repository) | |
320 | return 0; | |
321 | if (lstat(path, &st) < 0) | |
322 | return -1; | |
323 | mode = st.st_mode; | |
324 | ||
325 | if (shared_repository) { | |
326 | int tweak = shared_repository; | |
327 | if (!(mode & S_IWUSR)) | |
328 | tweak &= ~0222; | |
329 | mode |= tweak; | |
330 | } else { | |
331 | /* Preserve old PERM_UMASK behaviour */ | |
332 | if (mode & S_IWUSR) | |
333 | mode |= S_IWGRP; | |
334 | } | |
335 | ||
336 | if (S_ISDIR(mode)) { | |
337 | mode |= FORCE_DIR_SET_GID; | |
338 | ||
339 | /* Copy read bits to execute bits */ | |
340 | mode |= (shared_repository & 0444) >> 2; | |
341 | } | |
342 | ||
343 | if ((mode & st.st_mode) != mode && chmod(path, mode) < 0) | |
344 | return -2; | |
345 | return 0; | |
346 | } | |
347 | ||
348 | const char *make_relative_path(const char *abs, const char *base) | |
349 | { | |
350 | static char buf[PATH_MAX + 1]; | |
351 | int baselen; | |
352 | if (!base) | |
353 | return abs; | |
354 | baselen = strlen(base); | |
355 | if (prefixcmp(abs, base)) | |
356 | return abs; | |
357 | if (abs[baselen] == '/') | |
358 | baselen++; | |
359 | else if (base[baselen - 1] != '/') | |
360 | return abs; | |
361 | strcpy(buf, abs + baselen); | |
362 | return buf; | |
363 | } | |
364 | ||
365 | /* | |
366 | * path = absolute path | |
367 | * buf = buffer of at least max(2, strlen(path)+1) bytes | |
368 | * It is okay if buf == path, but they should not overlap otherwise. | |
369 | * | |
370 | * Performs the following normalizations on path, storing the result in buf: | |
371 | * - Removes trailing slashes. | |
372 | * - Removes empty components. | |
373 | * - Removes "." components. | |
374 | * - Removes ".." components, and the components the precede them. | |
375 | * "" and paths that contain only slashes are normalized to "/". | |
376 | * Returns the length of the output. | |
377 | * | |
378 | * Note that this function is purely textual. It does not follow symlinks, | |
379 | * verify the existence of the path, or make any system calls. | |
380 | */ | |
381 | int normalize_absolute_path(char *buf, const char *path) | |
382 | { | |
383 | const char *comp_start = path, *comp_end = path; | |
384 | char *dst = buf; | |
385 | int comp_len; | |
386 | assert(buf); | |
387 | assert(path); | |
388 | ||
389 | while (*comp_start) { | |
390 | assert(*comp_start == '/'); | |
391 | while (*++comp_end && *comp_end != '/') | |
392 | ; /* nothing */ | |
393 | comp_len = comp_end - comp_start; | |
394 | ||
395 | if (!strncmp("/", comp_start, comp_len) || | |
396 | !strncmp("/.", comp_start, comp_len)) | |
397 | goto next; | |
398 | ||
399 | if (!strncmp("/..", comp_start, comp_len)) { | |
400 | while (dst > buf && *--dst != '/') | |
401 | ; /* nothing */ | |
402 | goto next; | |
403 | } | |
404 | ||
405 | memmove(dst, comp_start, comp_len); | |
406 | dst += comp_len; | |
407 | next: | |
408 | comp_start = comp_end; | |
409 | } | |
410 | ||
411 | if (dst == buf) | |
412 | *dst++ = '/'; | |
413 | ||
414 | *dst = '\0'; | |
415 | return dst - buf; | |
416 | } | |
417 | ||
418 | /* | |
419 | * path = Canonical absolute path | |
420 | * prefix_list = Colon-separated list of absolute paths | |
421 | * | |
422 | * Determines, for each path in prefix_list, whether the "prefix" really | |
423 | * is an ancestor directory of path. Returns the length of the longest | |
424 | * ancestor directory, excluding any trailing slashes, or -1 if no prefix | |
425 | * is an ancestor. (Note that this means 0 is returned if prefix_list is | |
426 | * "/".) "/foo" is not considered an ancestor of "/foobar". Directories | |
427 | * are not considered to be their own ancestors. path must be in a | |
428 | * canonical form: empty components, or "." or ".." components are not | |
429 | * allowed. prefix_list may be null, which is like "". | |
430 | */ | |
431 | int longest_ancestor_length(const char *path, const char *prefix_list) | |
432 | { | |
433 | char buf[PATH_MAX+1]; | |
434 | const char *ceil, *colon; | |
435 | int len, max_len = -1; | |
436 | ||
437 | if (prefix_list == NULL || !strcmp(path, "/")) | |
438 | return -1; | |
439 | ||
440 | for (colon = ceil = prefix_list; *colon; ceil = colon+1) { | |
441 | for (colon = ceil; *colon && *colon != ':'; colon++); | |
442 | len = colon - ceil; | |
443 | if (len == 0 || len > PATH_MAX || !is_absolute_path(ceil)) | |
444 | continue; | |
445 | strlcpy(buf, ceil, len+1); | |
446 | len = normalize_absolute_path(buf, buf); | |
447 | /* Strip "trailing slashes" from "/". */ | |
448 | if (len == 1) | |
449 | len = 0; | |
450 | ||
451 | if (!strncmp(path, buf, len) && | |
452 | path[len] == '/' && | |
453 | len > max_len) { | |
454 | max_len = len; | |
455 | } | |
456 | } | |
457 | ||
458 | return max_len; | |
459 | } |