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