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Commit | Line | Data |
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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 | ||
a876ed83 | 9 | const char *resolve_ref(const char *path, unsigned char *sha1, int reading) |
8a65ff76 | 10 | { |
a876ed83 JH |
11 | int depth = MAXDEPTH, len; |
12 | char buffer[256]; | |
ca8db142 | 13 | |
a876ed83 JH |
14 | for (;;) { |
15 | struct stat st; | |
16 | char *buf; | |
17 | int fd; | |
8a65ff76 | 18 | |
a876ed83 JH |
19 | if (--depth < 0) |
20 | return NULL; | |
ca8db142 | 21 | |
a876ed83 JH |
22 | /* Special case: non-existing file. |
23 | * Not having the refs/heads/new-branch is OK | |
24 | * if we are writing into it, so is .git/HEAD | |
25 | * that points at refs/heads/master still to be | |
26 | * born. It is NOT OK if we are resolving for | |
27 | * reading. | |
28 | */ | |
29 | if (lstat(path, &st) < 0) { | |
30 | if (reading || errno != ENOENT) | |
31 | return NULL; | |
32 | memset(sha1, 0, 20); | |
33 | return path; | |
34 | } | |
ca8db142 | 35 | |
a876ed83 JH |
36 | /* Follow "normalized" - ie "refs/.." symlinks by hand */ |
37 | if (S_ISLNK(st.st_mode)) { | |
38 | len = readlink(path, buffer, sizeof(buffer)-1); | |
39 | if (len >= 5 && !memcmp("refs/", buffer, 5)) { | |
40 | path = git_path("%.*s", len, buffer); | |
41 | continue; | |
42 | } | |
ca8db142 | 43 | } |
a876ed83 JH |
44 | |
45 | /* | |
46 | * Anything else, just open it and try to use it as | |
47 | * a ref | |
48 | */ | |
49 | fd = open(path, O_RDONLY); | |
50 | if (fd < 0) | |
51 | return NULL; | |
52 | len = read(fd, buffer, sizeof(buffer)-1); | |
53 | close(fd); | |
54 | ||
55 | /* | |
56 | * Is it a symbolic ref? | |
57 | */ | |
58 | if (len < 4 || memcmp("ref:", buffer, 4)) | |
59 | break; | |
60 | buf = buffer + 4; | |
61 | len -= 4; | |
62 | while (len && isspace(*buf)) | |
63 | buf++, len--; | |
64 | while (len && isspace(buf[len-1])) | |
65 | buf[--len] = 0; | |
66 | path = git_path("%.*s", len, buf); | |
8a65ff76 | 67 | } |
a876ed83 JH |
68 | if (len < 40 || get_sha1_hex(buffer, sha1)) |
69 | return NULL; | |
70 | return path; | |
71 | } | |
72 | ||
8098a178 JH |
73 | int create_symref(const char *git_HEAD, const char *refs_heads_master) |
74 | { | |
8098a178 JH |
75 | const char *lockpath; |
76 | char ref[1000]; | |
77 | int fd, len, written; | |
78 | ||
2fabd217 | 79 | #ifdef USE_SYMLINK_HEAD |
f8348be3 JS |
80 | if (!only_use_symrefs) { |
81 | unlink(git_HEAD); | |
82 | if (!symlink(refs_heads_master, git_HEAD)) | |
83 | return 0; | |
84 | fprintf(stderr, "no symlink - falling back to symbolic ref\n"); | |
85 | } | |
303958dc JS |
86 | #endif |
87 | ||
8098a178 JH |
88 | len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master); |
89 | if (sizeof(ref) <= len) { | |
90 | error("refname too long: %s", refs_heads_master); | |
91 | return -1; | |
92 | } | |
93 | lockpath = mkpath("%s.lock", git_HEAD); | |
94 | fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666); | |
95 | written = write(fd, ref, len); | |
96 | close(fd); | |
97 | if (written != len) { | |
98 | unlink(lockpath); | |
99 | error("Unable to write to %s", lockpath); | |
100 | return -2; | |
101 | } | |
102 | if (rename(lockpath, git_HEAD) < 0) { | |
103 | unlink(lockpath); | |
104 | error("Unable to create %s", git_HEAD); | |
105 | return -3; | |
106 | } | |
107 | return 0; | |
8098a178 JH |
108 | } |
109 | ||
a876ed83 JH |
110 | int read_ref(const char *filename, unsigned char *sha1) |
111 | { | |
112 | if (resolve_ref(filename, sha1, 1)) | |
113 | return 0; | |
114 | return -1; | |
8a65ff76 LT |
115 | } |
116 | ||
944d8589 | 117 | static int do_for_each_ref(const char *base, int (*fn)(const char *path, const unsigned char *sha1)) |
8a65ff76 LT |
118 | { |
119 | int retval = 0; | |
4ec99bf0 | 120 | DIR *dir = opendir(git_path("%s", base)); |
8a65ff76 LT |
121 | |
122 | if (dir) { | |
123 | struct dirent *de; | |
124 | int baselen = strlen(base); | |
125 | char *path = xmalloc(baselen + 257); | |
6cada6a9 LT |
126 | |
127 | if (!strncmp(base, "./", 2)) { | |
128 | base += 2; | |
129 | baselen -= 2; | |
130 | } | |
8a65ff76 | 131 | memcpy(path, base, baselen); |
944d8589 LT |
132 | if (baselen && base[baselen-1] != '/') |
133 | path[baselen++] = '/'; | |
8a65ff76 LT |
134 | |
135 | while ((de = readdir(dir)) != NULL) { | |
136 | unsigned char sha1[20]; | |
137 | struct stat st; | |
138 | int namelen; | |
139 | ||
140 | if (de->d_name[0] == '.') | |
141 | continue; | |
142 | namelen = strlen(de->d_name); | |
143 | if (namelen > 255) | |
144 | continue; | |
145 | memcpy(path + baselen, de->d_name, namelen+1); | |
a7e66ae3 | 146 | if (stat(git_path("%s", path), &st) < 0) |
8a65ff76 LT |
147 | continue; |
148 | if (S_ISDIR(st.st_mode)) { | |
8a65ff76 LT |
149 | retval = do_for_each_ref(path, fn); |
150 | if (retval) | |
151 | break; | |
152 | continue; | |
153 | } | |
c401cb48 | 154 | if (read_ref(git_path("%s", path), sha1) < 0) { |
f61c2c97 | 155 | error("%s points nowhere!", path); |
8a65ff76 | 156 | continue; |
c401cb48 JS |
157 | } |
158 | if (!has_sha1_file(sha1)) { | |
f61c2c97 JH |
159 | error("%s does not point to a valid " |
160 | "commit object!", path); | |
8a65ff76 | 161 | continue; |
c401cb48 | 162 | } |
8a65ff76 LT |
163 | retval = fn(path, sha1); |
164 | if (retval) | |
165 | break; | |
166 | } | |
167 | free(path); | |
168 | closedir(dir); | |
169 | } | |
170 | return retval; | |
171 | } | |
172 | ||
723c31fe LT |
173 | int head_ref(int (*fn)(const char *path, const unsigned char *sha1)) |
174 | { | |
175 | unsigned char sha1[20]; | |
ca8db142 | 176 | if (!read_ref(git_path("HEAD"), sha1)) |
99a0a6e0 | 177 | return fn("HEAD", sha1); |
2f34ba32 | 178 | return 0; |
723c31fe LT |
179 | } |
180 | ||
944d8589 | 181 | int for_each_ref(int (*fn)(const char *path, const unsigned char *sha1)) |
8a65ff76 | 182 | { |
99a0a6e0 | 183 | return do_for_each_ref("refs", fn); |
8a65ff76 LT |
184 | } |
185 | ||
95fc7512 DB |
186 | static char *ref_file_name(const char *ref) |
187 | { | |
188 | char *base = get_refs_directory(); | |
189 | int baselen = strlen(base); | |
190 | int reflen = strlen(ref); | |
191 | char *ret = xmalloc(baselen + 2 + reflen); | |
192 | sprintf(ret, "%s/%s", base, ref); | |
193 | return ret; | |
194 | } | |
195 | ||
196 | static char *ref_lock_file_name(const char *ref) | |
197 | { | |
198 | char *base = get_refs_directory(); | |
199 | int baselen = strlen(base); | |
200 | int reflen = strlen(ref); | |
201 | char *ret = xmalloc(baselen + 7 + reflen); | |
202 | sprintf(ret, "%s/%s.lock", base, ref); | |
203 | return ret; | |
204 | } | |
205 | ||
95fc7512 DB |
206 | int get_ref_sha1(const char *ref, unsigned char *sha1) |
207 | { | |
ca8db142 LT |
208 | const char *filename; |
209 | ||
95fc7512 DB |
210 | if (check_ref_format(ref)) |
211 | return -1; | |
ca8db142 LT |
212 | filename = git_path("refs/%s", ref); |
213 | return read_ref(filename, sha1); | |
95fc7512 DB |
214 | } |
215 | ||
216 | static int lock_ref_file(const char *filename, const char *lock_filename, | |
217 | const unsigned char *old_sha1) | |
218 | { | |
219 | int fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666); | |
220 | unsigned char current_sha1[20]; | |
221 | int retval; | |
222 | if (fd < 0) { | |
223 | return error("Couldn't open lock file for %s: %s", | |
224 | filename, strerror(errno)); | |
225 | } | |
ca8db142 | 226 | retval = read_ref(filename, current_sha1); |
95fc7512 DB |
227 | if (old_sha1) { |
228 | if (retval) { | |
229 | close(fd); | |
230 | unlink(lock_filename); | |
231 | return error("Could not read the current value of %s", | |
232 | filename); | |
233 | } | |
234 | if (memcmp(current_sha1, old_sha1, 20)) { | |
235 | close(fd); | |
236 | unlink(lock_filename); | |
237 | error("The current value of %s is %s", | |
238 | filename, sha1_to_hex(current_sha1)); | |
239 | return error("Expected %s", | |
240 | sha1_to_hex(old_sha1)); | |
241 | } | |
242 | } else { | |
243 | if (!retval) { | |
244 | close(fd); | |
245 | unlink(lock_filename); | |
246 | return error("Unexpectedly found a value of %s for %s", | |
247 | sha1_to_hex(current_sha1), filename); | |
248 | } | |
249 | } | |
250 | return fd; | |
251 | } | |
252 | ||
253 | int lock_ref_sha1(const char *ref, const unsigned char *old_sha1) | |
254 | { | |
255 | char *filename; | |
256 | char *lock_filename; | |
257 | int retval; | |
258 | if (check_ref_format(ref)) | |
259 | return -1; | |
260 | filename = ref_file_name(ref); | |
261 | lock_filename = ref_lock_file_name(ref); | |
262 | retval = lock_ref_file(filename, lock_filename, old_sha1); | |
263 | free(filename); | |
264 | free(lock_filename); | |
265 | return retval; | |
266 | } | |
267 | ||
268 | static int write_ref_file(const char *filename, | |
269 | const char *lock_filename, int fd, | |
270 | const unsigned char *sha1) | |
271 | { | |
272 | char *hex = sha1_to_hex(sha1); | |
273 | char term = '\n'; | |
274 | if (write(fd, hex, 40) < 40 || | |
275 | write(fd, &term, 1) < 1) { | |
bd2afde8 | 276 | error("Couldn't write %s", filename); |
95fc7512 DB |
277 | close(fd); |
278 | return -1; | |
279 | } | |
280 | close(fd); | |
281 | rename(lock_filename, filename); | |
282 | return 0; | |
283 | } | |
284 | ||
285 | int write_ref_sha1(const char *ref, int fd, const unsigned char *sha1) | |
286 | { | |
287 | char *filename; | |
288 | char *lock_filename; | |
289 | int retval; | |
290 | if (fd < 0) | |
291 | return -1; | |
292 | if (check_ref_format(ref)) | |
293 | return -1; | |
294 | filename = ref_file_name(ref); | |
295 | lock_filename = ref_lock_file_name(ref); | |
64224caf JH |
296 | if (safe_create_leading_directories(filename)) |
297 | die("unable to create leading directory for %s", filename); | |
95fc7512 DB |
298 | retval = write_ref_file(filename, lock_filename, fd, sha1); |
299 | free(filename); | |
300 | free(lock_filename); | |
301 | return retval; | |
302 | } | |
303 | ||
03feddd6 JH |
304 | /* |
305 | * Make sure "ref" is something reasonable to have under ".git/refs/"; | |
306 | * We do not like it if: | |
307 | * | |
308 | * - any path component of it begins with ".", or | |
309 | * - it has double dots "..", or | |
310 | * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or | |
311 | * - it ends with a "/". | |
312 | */ | |
313 | ||
314 | static inline int bad_ref_char(int ch) | |
315 | { | |
316 | return (((unsigned) ch) <= ' ' || | |
68283999 JH |
317 | ch == '~' || ch == '^' || ch == ':' || |
318 | /* 2.13 Pattern Matching Notation */ | |
319 | ch == '?' || ch == '*' || ch == '['); | |
03feddd6 JH |
320 | } |
321 | ||
95fc7512 DB |
322 | int check_ref_format(const char *ref) |
323 | { | |
03feddd6 JH |
324 | int ch, level; |
325 | const char *cp = ref; | |
326 | ||
327 | level = 0; | |
328 | while (1) { | |
329 | while ((ch = *cp++) == '/') | |
330 | ; /* tolerate duplicated slashes */ | |
331 | if (!ch) | |
332 | return -1; /* should not end with slashes */ | |
333 | ||
334 | /* we are at the beginning of the path component */ | |
335 | if (ch == '.' || bad_ref_char(ch)) | |
336 | return -1; | |
337 | ||
338 | /* scan the rest of the path component */ | |
339 | while ((ch = *cp++) != 0) { | |
340 | if (bad_ref_char(ch)) | |
341 | return -1; | |
342 | if (ch == '/') | |
343 | break; | |
344 | if (ch == '.' && *cp == '.') | |
345 | return -1; | |
346 | } | |
347 | level++; | |
348 | if (!ch) { | |
349 | if (level < 2) | |
350 | return -1; /* at least of form "heads/blah" */ | |
351 | return 0; | |
352 | } | |
353 | } | |
95fc7512 DB |
354 | } |
355 | ||
356 | int write_ref_sha1_unlocked(const char *ref, const unsigned char *sha1) | |
357 | { | |
358 | char *filename; | |
359 | char *lock_filename; | |
360 | int fd; | |
361 | int retval; | |
362 | if (check_ref_format(ref)) | |
363 | return -1; | |
364 | filename = ref_file_name(ref); | |
365 | lock_filename = ref_lock_file_name(ref); | |
64224caf JH |
366 | if (safe_create_leading_directories(filename)) |
367 | die("unable to create leading directory for %s", filename); | |
95fc7512 DB |
368 | fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666); |
369 | if (fd < 0) { | |
370 | error("Writing %s", lock_filename); | |
371 | perror("Open"); | |
372 | } | |
373 | retval = write_ref_file(filename, lock_filename, fd, sha1); | |
374 | free(filename); | |
375 | free(lock_filename); | |
376 | return retval; | |
377 | } |