6 /* We allow "recursive" symbolic refs. Only within reason, though */
9 #ifndef USE_SYMLINK_HEAD
10 #define USE_SYMLINK_HEAD 1
13 int validate_symref(const char *path)
16 char *buf, buffer[256];
19 if (lstat(path, &st) < 0)
22 /* Make sure it is a "refs/.." symlink */
23 if (S_ISLNK(st.st_mode)) {
24 len = readlink(path, buffer, sizeof(buffer)-1);
25 if (len >= 5 && !memcmp("refs/", buffer, 5))
31 * Anything else, just open it and try to see if it is a symbolic ref.
33 fd = open(path, O_RDONLY);
36 len = read(fd, buffer, sizeof(buffer)-1);
40 * Is it a symbolic ref?
42 if (len < 4 || memcmp("ref:", buffer, 4))
46 while (len && isspace(*buf))
48 if (len >= 5 && !memcmp("refs/", buf, 5))
53 const char *resolve_ref(const char *path, unsigned char *sha1, int reading)
55 int depth = MAXDEPTH, len;
66 /* Special case: non-existing file.
67 * Not having the refs/heads/new-branch is OK
68 * if we are writing into it, so is .git/HEAD
69 * that points at refs/heads/master still to be
70 * born. It is NOT OK if we are resolving for
73 if (lstat(path, &st) < 0) {
74 if (reading || errno != ENOENT)
80 /* Follow "normalized" - ie "refs/.." symlinks by hand */
81 if (S_ISLNK(st.st_mode)) {
82 len = readlink(path, buffer, sizeof(buffer)-1);
83 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
84 path = git_path("%.*s", len, buffer);
90 * Anything else, just open it and try to use it as
93 fd = open(path, O_RDONLY);
96 len = read(fd, buffer, sizeof(buffer)-1);
100 * Is it a symbolic ref?
102 if (len < 4 || memcmp("ref:", buffer, 4))
106 while (len && isspace(*buf))
108 while (len && isspace(buf[len-1]))
110 path = git_path("%.*s", len, buf);
112 if (len < 40 || get_sha1_hex(buffer, sha1))
117 int create_symref(const char *git_HEAD, const char *refs_heads_master)
121 return symlink(refs_heads_master, git_HEAD);
123 const char *lockpath;
125 int fd, len, written;
127 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
128 if (sizeof(ref) <= len) {
129 error("refname too long: %s", refs_heads_master);
132 lockpath = mkpath("%s.lock", git_HEAD);
133 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
134 written = write(fd, ref, len);
136 if (written != len) {
138 error("Unable to write to %s", lockpath);
141 if (rename(lockpath, git_HEAD) < 0) {
143 error("Unable to create %s", git_HEAD);
150 int read_ref(const char *filename, unsigned char *sha1)
152 if (resolve_ref(filename, sha1, 1))
157 static int do_for_each_ref(const char *base, int (*fn)(const char *path, const unsigned char *sha1))
160 DIR *dir = opendir(git_path("%s", base));
164 int baselen = strlen(base);
165 char *path = xmalloc(baselen + 257);
167 if (!strncmp(base, "./", 2)) {
171 memcpy(path, base, baselen);
172 if (baselen && base[baselen-1] != '/')
173 path[baselen++] = '/';
175 while ((de = readdir(dir)) != NULL) {
176 unsigned char sha1[20];
180 if (de->d_name[0] == '.')
182 namelen = strlen(de->d_name);
185 memcpy(path + baselen, de->d_name, namelen+1);
186 if (stat(git_path("%s", path), &st) < 0)
188 if (S_ISDIR(st.st_mode)) {
189 retval = do_for_each_ref(path, fn);
194 if (read_ref(git_path("%s", path), sha1) < 0)
196 if (!has_sha1_file(sha1))
198 retval = fn(path, sha1);
208 int head_ref(int (*fn)(const char *path, const unsigned char *sha1))
210 unsigned char sha1[20];
211 if (!read_ref(git_path("HEAD"), sha1))
212 return fn("HEAD", sha1);
216 int for_each_ref(int (*fn)(const char *path, const unsigned char *sha1))
218 return do_for_each_ref("refs", fn);
221 static char *ref_file_name(const char *ref)
223 char *base = get_refs_directory();
224 int baselen = strlen(base);
225 int reflen = strlen(ref);
226 char *ret = xmalloc(baselen + 2 + reflen);
227 sprintf(ret, "%s/%s", base, ref);
231 static char *ref_lock_file_name(const char *ref)
233 char *base = get_refs_directory();
234 int baselen = strlen(base);
235 int reflen = strlen(ref);
236 char *ret = xmalloc(baselen + 7 + reflen);
237 sprintf(ret, "%s/%s.lock", base, ref);
241 int get_ref_sha1(const char *ref, unsigned char *sha1)
243 const char *filename;
245 if (check_ref_format(ref))
247 filename = git_path("refs/%s", ref);
248 return read_ref(filename, sha1);
251 static int lock_ref_file(const char *filename, const char *lock_filename,
252 const unsigned char *old_sha1)
254 int fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
255 unsigned char current_sha1[20];
258 return error("Couldn't open lock file for %s: %s",
259 filename, strerror(errno));
261 retval = read_ref(filename, current_sha1);
265 unlink(lock_filename);
266 return error("Could not read the current value of %s",
269 if (memcmp(current_sha1, old_sha1, 20)) {
271 unlink(lock_filename);
272 error("The current value of %s is %s",
273 filename, sha1_to_hex(current_sha1));
274 return error("Expected %s",
275 sha1_to_hex(old_sha1));
280 unlink(lock_filename);
281 return error("Unexpectedly found a value of %s for %s",
282 sha1_to_hex(current_sha1), filename);
288 int lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
293 if (check_ref_format(ref))
295 filename = ref_file_name(ref);
296 lock_filename = ref_lock_file_name(ref);
297 retval = lock_ref_file(filename, lock_filename, old_sha1);
303 static int write_ref_file(const char *filename,
304 const char *lock_filename, int fd,
305 const unsigned char *sha1)
307 char *hex = sha1_to_hex(sha1);
309 if (write(fd, hex, 40) < 40 ||
310 write(fd, &term, 1) < 1) {
311 error("Couldn't write %s\n", filename);
316 rename(lock_filename, filename);
320 int write_ref_sha1(const char *ref, int fd, const unsigned char *sha1)
327 if (check_ref_format(ref))
329 filename = ref_file_name(ref);
330 lock_filename = ref_lock_file_name(ref);
331 retval = write_ref_file(filename, lock_filename, fd, sha1);
338 * Make sure "ref" is something reasonable to have under ".git/refs/";
339 * We do not like it if:
341 * - any path component of it begins with ".", or
342 * - it has double dots "..", or
343 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
344 * - it ends with a "/".
347 static inline int bad_ref_char(int ch)
349 return (((unsigned) ch) <= ' ' ||
350 ch == '~' || ch == '^' || ch == ':');
353 int check_ref_format(const char *ref)
356 const char *cp = ref;
360 while ((ch = *cp++) == '/')
361 ; /* tolerate duplicated slashes */
363 return -1; /* should not end with slashes */
365 /* we are at the beginning of the path component */
366 if (ch == '.' || bad_ref_char(ch))
369 /* scan the rest of the path component */
370 while ((ch = *cp++) != 0) {
371 if (bad_ref_char(ch))
375 if (ch == '.' && *cp == '.')
381 return -1; /* at least of form "heads/blah" */
387 int write_ref_sha1_unlocked(const char *ref, const unsigned char *sha1)
393 if (check_ref_format(ref))
395 filename = ref_file_name(ref);
396 lock_filename = ref_lock_file_name(ref);
397 fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
399 error("Writing %s", lock_filename);
402 retval = write_ref_file(filename, lock_filename, fd, sha1);