]>
Commit | Line | Data |
---|---|---|
95fc7512 DB |
1 | #include "refs.h" |
2 | #include "cache.h" | |
3 | ||
4 | #include <errno.h> | |
5 | ||
ca8db142 LT |
6 | /* We allow "recursive" symbolic refs. Only within reason, though */ |
7 | #define MAXDEPTH 5 | |
8 | ||
8098a178 JH |
9 | #ifndef USE_SYMLINK_HEAD |
10 | #define USE_SYMLINK_HEAD 1 | |
11 | #endif | |
12 | ||
a876ed83 | 13 | const char *resolve_ref(const char *path, unsigned char *sha1, int reading) |
8a65ff76 | 14 | { |
a876ed83 JH |
15 | int depth = MAXDEPTH, len; |
16 | char buffer[256]; | |
ca8db142 | 17 | |
a876ed83 JH |
18 | for (;;) { |
19 | struct stat st; | |
20 | char *buf; | |
21 | int fd; | |
8a65ff76 | 22 | |
a876ed83 JH |
23 | if (--depth < 0) |
24 | return NULL; | |
ca8db142 | 25 | |
a876ed83 JH |
26 | /* Special case: non-existing file. |
27 | * Not having the refs/heads/new-branch is OK | |
28 | * if we are writing into it, so is .git/HEAD | |
29 | * that points at refs/heads/master still to be | |
30 | * born. It is NOT OK if we are resolving for | |
31 | * reading. | |
32 | */ | |
33 | if (lstat(path, &st) < 0) { | |
34 | if (reading || errno != ENOENT) | |
35 | return NULL; | |
36 | memset(sha1, 0, 20); | |
37 | return path; | |
38 | } | |
ca8db142 | 39 | |
a876ed83 JH |
40 | /* Follow "normalized" - ie "refs/.." symlinks by hand */ |
41 | if (S_ISLNK(st.st_mode)) { | |
42 | len = readlink(path, buffer, sizeof(buffer)-1); | |
43 | if (len >= 5 && !memcmp("refs/", buffer, 5)) { | |
44 | path = git_path("%.*s", len, buffer); | |
45 | continue; | |
46 | } | |
ca8db142 | 47 | } |
a876ed83 JH |
48 | |
49 | /* | |
50 | * Anything else, just open it and try to use it as | |
51 | * a ref | |
52 | */ | |
53 | fd = open(path, O_RDONLY); | |
54 | if (fd < 0) | |
55 | return NULL; | |
56 | len = read(fd, buffer, sizeof(buffer)-1); | |
57 | close(fd); | |
58 | ||
59 | /* | |
60 | * Is it a symbolic ref? | |
61 | */ | |
62 | if (len < 4 || memcmp("ref:", buffer, 4)) | |
63 | break; | |
64 | buf = buffer + 4; | |
65 | len -= 4; | |
66 | while (len && isspace(*buf)) | |
67 | buf++, len--; | |
68 | while (len && isspace(buf[len-1])) | |
69 | buf[--len] = 0; | |
70 | path = git_path("%.*s", len, buf); | |
8a65ff76 | 71 | } |
a876ed83 JH |
72 | if (len < 40 || get_sha1_hex(buffer, sha1)) |
73 | return NULL; | |
74 | return path; | |
75 | } | |
76 | ||
8098a178 JH |
77 | int create_symref(const char *git_HEAD, const char *refs_heads_master) |
78 | { | |
8098a178 JH |
79 | const char *lockpath; |
80 | char ref[1000]; | |
81 | int fd, len, written; | |
82 | ||
303958dc | 83 | #if USE_SYMLINK_HEAD |
f8348be3 JS |
84 | if (!only_use_symrefs) { |
85 | unlink(git_HEAD); | |
86 | if (!symlink(refs_heads_master, git_HEAD)) | |
87 | return 0; | |
88 | fprintf(stderr, "no symlink - falling back to symbolic ref\n"); | |
89 | } | |
303958dc JS |
90 | #endif |
91 | ||
8098a178 JH |
92 | len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master); |
93 | if (sizeof(ref) <= len) { | |
94 | error("refname too long: %s", refs_heads_master); | |
95 | return -1; | |
96 | } | |
97 | lockpath = mkpath("%s.lock", git_HEAD); | |
98 | fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666); | |
99 | written = write(fd, ref, len); | |
100 | close(fd); | |
101 | if (written != len) { | |
102 | unlink(lockpath); | |
103 | error("Unable to write to %s", lockpath); | |
104 | return -2; | |
105 | } | |
106 | if (rename(lockpath, git_HEAD) < 0) { | |
107 | unlink(lockpath); | |
108 | error("Unable to create %s", git_HEAD); | |
109 | return -3; | |
110 | } | |
111 | return 0; | |
8098a178 JH |
112 | } |
113 | ||
a876ed83 JH |
114 | int read_ref(const char *filename, unsigned char *sha1) |
115 | { | |
116 | if (resolve_ref(filename, sha1, 1)) | |
117 | return 0; | |
118 | return -1; | |
8a65ff76 LT |
119 | } |
120 | ||
944d8589 | 121 | static int do_for_each_ref(const char *base, int (*fn)(const char *path, const unsigned char *sha1)) |
8a65ff76 LT |
122 | { |
123 | int retval = 0; | |
4ec99bf0 | 124 | DIR *dir = opendir(git_path("%s", base)); |
8a65ff76 LT |
125 | |
126 | if (dir) { | |
127 | struct dirent *de; | |
128 | int baselen = strlen(base); | |
129 | char *path = xmalloc(baselen + 257); | |
6cada6a9 LT |
130 | |
131 | if (!strncmp(base, "./", 2)) { | |
132 | base += 2; | |
133 | baselen -= 2; | |
134 | } | |
8a65ff76 | 135 | memcpy(path, base, baselen); |
944d8589 LT |
136 | if (baselen && base[baselen-1] != '/') |
137 | path[baselen++] = '/'; | |
8a65ff76 LT |
138 | |
139 | while ((de = readdir(dir)) != NULL) { | |
140 | unsigned char sha1[20]; | |
141 | struct stat st; | |
142 | int namelen; | |
143 | ||
144 | if (de->d_name[0] == '.') | |
145 | continue; | |
146 | namelen = strlen(de->d_name); | |
147 | if (namelen > 255) | |
148 | continue; | |
149 | memcpy(path + baselen, de->d_name, namelen+1); | |
a7e66ae3 | 150 | if (stat(git_path("%s", path), &st) < 0) |
8a65ff76 LT |
151 | continue; |
152 | if (S_ISDIR(st.st_mode)) { | |
8a65ff76 LT |
153 | retval = do_for_each_ref(path, fn); |
154 | if (retval) | |
155 | break; | |
156 | continue; | |
157 | } | |
ca8db142 | 158 | if (read_ref(git_path("%s", path), sha1) < 0) |
8a65ff76 LT |
159 | continue; |
160 | if (!has_sha1_file(sha1)) | |
161 | continue; | |
162 | retval = fn(path, sha1); | |
163 | if (retval) | |
164 | break; | |
165 | } | |
166 | free(path); | |
167 | closedir(dir); | |
168 | } | |
169 | return retval; | |
170 | } | |
171 | ||
723c31fe LT |
172 | int head_ref(int (*fn)(const char *path, const unsigned char *sha1)) |
173 | { | |
174 | unsigned char sha1[20]; | |
ca8db142 | 175 | if (!read_ref(git_path("HEAD"), sha1)) |
99a0a6e0 | 176 | return fn("HEAD", sha1); |
2f34ba32 | 177 | return 0; |
723c31fe LT |
178 | } |
179 | ||
944d8589 | 180 | int for_each_ref(int (*fn)(const char *path, const unsigned char *sha1)) |
8a65ff76 | 181 | { |
99a0a6e0 | 182 | return do_for_each_ref("refs", fn); |
8a65ff76 LT |
183 | } |
184 | ||
95fc7512 DB |
185 | static char *ref_file_name(const char *ref) |
186 | { | |
187 | char *base = get_refs_directory(); | |
188 | int baselen = strlen(base); | |
189 | int reflen = strlen(ref); | |
190 | char *ret = xmalloc(baselen + 2 + reflen); | |
191 | sprintf(ret, "%s/%s", base, ref); | |
192 | return ret; | |
193 | } | |
194 | ||
195 | static char *ref_lock_file_name(const char *ref) | |
196 | { | |
197 | char *base = get_refs_directory(); | |
198 | int baselen = strlen(base); | |
199 | int reflen = strlen(ref); | |
200 | char *ret = xmalloc(baselen + 7 + reflen); | |
201 | sprintf(ret, "%s/%s.lock", base, ref); | |
202 | return ret; | |
203 | } | |
204 | ||
95fc7512 DB |
205 | int get_ref_sha1(const char *ref, unsigned char *sha1) |
206 | { | |
ca8db142 LT |
207 | const char *filename; |
208 | ||
95fc7512 DB |
209 | if (check_ref_format(ref)) |
210 | return -1; | |
ca8db142 LT |
211 | filename = git_path("refs/%s", ref); |
212 | return read_ref(filename, sha1); | |
95fc7512 DB |
213 | } |
214 | ||
215 | static int lock_ref_file(const char *filename, const char *lock_filename, | |
216 | const unsigned char *old_sha1) | |
217 | { | |
218 | int fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666); | |
219 | unsigned char current_sha1[20]; | |
220 | int retval; | |
221 | if (fd < 0) { | |
222 | return error("Couldn't open lock file for %s: %s", | |
223 | filename, strerror(errno)); | |
224 | } | |
ca8db142 | 225 | retval = read_ref(filename, current_sha1); |
95fc7512 DB |
226 | if (old_sha1) { |
227 | if (retval) { | |
228 | close(fd); | |
229 | unlink(lock_filename); | |
230 | return error("Could not read the current value of %s", | |
231 | filename); | |
232 | } | |
233 | if (memcmp(current_sha1, old_sha1, 20)) { | |
234 | close(fd); | |
235 | unlink(lock_filename); | |
236 | error("The current value of %s is %s", | |
237 | filename, sha1_to_hex(current_sha1)); | |
238 | return error("Expected %s", | |
239 | sha1_to_hex(old_sha1)); | |
240 | } | |
241 | } else { | |
242 | if (!retval) { | |
243 | close(fd); | |
244 | unlink(lock_filename); | |
245 | return error("Unexpectedly found a value of %s for %s", | |
246 | sha1_to_hex(current_sha1), filename); | |
247 | } | |
248 | } | |
249 | return fd; | |
250 | } | |
251 | ||
252 | int lock_ref_sha1(const char *ref, const unsigned char *old_sha1) | |
253 | { | |
254 | char *filename; | |
255 | char *lock_filename; | |
256 | int retval; | |
257 | if (check_ref_format(ref)) | |
258 | return -1; | |
259 | filename = ref_file_name(ref); | |
260 | lock_filename = ref_lock_file_name(ref); | |
261 | retval = lock_ref_file(filename, lock_filename, old_sha1); | |
262 | free(filename); | |
263 | free(lock_filename); | |
264 | return retval; | |
265 | } | |
266 | ||
267 | static int write_ref_file(const char *filename, | |
268 | const char *lock_filename, int fd, | |
269 | const unsigned char *sha1) | |
270 | { | |
271 | char *hex = sha1_to_hex(sha1); | |
272 | char term = '\n'; | |
273 | if (write(fd, hex, 40) < 40 || | |
274 | write(fd, &term, 1) < 1) { | |
275 | error("Couldn't write %s\n", filename); | |
276 | close(fd); | |
277 | return -1; | |
278 | } | |
279 | close(fd); | |
280 | rename(lock_filename, filename); | |
281 | return 0; | |
282 | } | |
283 | ||
284 | int write_ref_sha1(const char *ref, int fd, const unsigned char *sha1) | |
285 | { | |
286 | char *filename; | |
287 | char *lock_filename; | |
288 | int retval; | |
289 | if (fd < 0) | |
290 | return -1; | |
291 | if (check_ref_format(ref)) | |
292 | return -1; | |
293 | filename = ref_file_name(ref); | |
294 | lock_filename = ref_lock_file_name(ref); | |
64224caf JH |
295 | if (safe_create_leading_directories(filename)) |
296 | die("unable to create leading directory for %s", filename); | |
95fc7512 DB |
297 | retval = write_ref_file(filename, lock_filename, fd, sha1); |
298 | free(filename); | |
299 | free(lock_filename); | |
300 | return retval; | |
301 | } | |
302 | ||
03feddd6 JH |
303 | /* |
304 | * Make sure "ref" is something reasonable to have under ".git/refs/"; | |
305 | * We do not like it if: | |
306 | * | |
307 | * - any path component of it begins with ".", or | |
308 | * - it has double dots "..", or | |
309 | * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or | |
310 | * - it ends with a "/". | |
311 | */ | |
312 | ||
313 | static inline int bad_ref_char(int ch) | |
314 | { | |
315 | return (((unsigned) ch) <= ' ' || | |
68283999 JH |
316 | ch == '~' || ch == '^' || ch == ':' || |
317 | /* 2.13 Pattern Matching Notation */ | |
318 | ch == '?' || ch == '*' || ch == '['); | |
03feddd6 JH |
319 | } |
320 | ||
95fc7512 DB |
321 | int check_ref_format(const char *ref) |
322 | { | |
03feddd6 JH |
323 | int ch, level; |
324 | const char *cp = ref; | |
325 | ||
326 | level = 0; | |
327 | while (1) { | |
328 | while ((ch = *cp++) == '/') | |
329 | ; /* tolerate duplicated slashes */ | |
330 | if (!ch) | |
331 | return -1; /* should not end with slashes */ | |
332 | ||
333 | /* we are at the beginning of the path component */ | |
334 | if (ch == '.' || bad_ref_char(ch)) | |
335 | return -1; | |
336 | ||
337 | /* scan the rest of the path component */ | |
338 | while ((ch = *cp++) != 0) { | |
339 | if (bad_ref_char(ch)) | |
340 | return -1; | |
341 | if (ch == '/') | |
342 | break; | |
343 | if (ch == '.' && *cp == '.') | |
344 | return -1; | |
345 | } | |
346 | level++; | |
347 | if (!ch) { | |
348 | if (level < 2) | |
349 | return -1; /* at least of form "heads/blah" */ | |
350 | return 0; | |
351 | } | |
352 | } | |
95fc7512 DB |
353 | } |
354 | ||
355 | int write_ref_sha1_unlocked(const char *ref, const unsigned char *sha1) | |
356 | { | |
357 | char *filename; | |
358 | char *lock_filename; | |
359 | int fd; | |
360 | int retval; | |
361 | if (check_ref_format(ref)) | |
362 | return -1; | |
363 | filename = ref_file_name(ref); | |
364 | lock_filename = ref_lock_file_name(ref); | |
64224caf JH |
365 | if (safe_create_leading_directories(filename)) |
366 | die("unable to create leading directory for %s", filename); | |
95fc7512 DB |
367 | fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666); |
368 | if (fd < 0) { | |
369 | error("Writing %s", lock_filename); | |
370 | perror("Open"); | |
371 | } | |
372 | retval = write_ref_file(filename, lock_filename, fd, sha1); | |
373 | free(filename); | |
374 | free(lock_filename); | |
375 | return retval; | |
376 | } |