#include <errno.h>
-static int read_ref(const char *refname, unsigned char *sha1)
+/* We allow "recursive" symbolic refs. Only within reason, though */
+#define MAXDEPTH 5
+
+#ifndef USE_SYMLINK_HEAD
+#define USE_SYMLINK_HEAD 1
+#endif
+
+const char *resolve_ref(const char *path, unsigned char *sha1, int reading)
{
- int ret = -1;
- int fd = open(git_path("%s", refname), O_RDONLY);
+ int depth = MAXDEPTH, len;
+ char buffer[256];
+
+ for (;;) {
+ struct stat st;
+ char *buf;
+ int fd;
+
+ if (--depth < 0)
+ return NULL;
- if (fd >= 0) {
- char buffer[60];
- if (read(fd, buffer, sizeof(buffer)) >= 40)
- ret = get_sha1_hex(buffer, sha1);
+ /* Special case: non-existing file.
+ * Not having the refs/heads/new-branch is OK
+ * if we are writing into it, so is .git/HEAD
+ * that points at refs/heads/master still to be
+ * born. It is NOT OK if we are resolving for
+ * reading.
+ */
+ if (lstat(path, &st) < 0) {
+ if (reading || errno != ENOENT)
+ return NULL;
+ memset(sha1, 0, 20);
+ return path;
+ }
+
+ /* Follow "normalized" - ie "refs/.." symlinks by hand */
+ if (S_ISLNK(st.st_mode)) {
+ len = readlink(path, buffer, sizeof(buffer)-1);
+ if (len >= 5 && !memcmp("refs/", buffer, 5)) {
+ path = git_path("%.*s", len, buffer);
+ continue;
+ }
+ }
+
+ /*
+ * Anything else, just open it and try to use it as
+ * a ref
+ */
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return NULL;
+ len = read(fd, buffer, sizeof(buffer)-1);
close(fd);
+
+ /*
+ * Is it a symbolic ref?
+ */
+ if (len < 4 || memcmp("ref:", buffer, 4))
+ break;
+ buf = buffer + 4;
+ len -= 4;
+ while (len && isspace(*buf))
+ buf++, len--;
+ while (len && isspace(buf[len-1]))
+ buf[--len] = 0;
+ path = git_path("%.*s", len, buf);
}
- return ret;
+ if (len < 40 || get_sha1_hex(buffer, sha1))
+ return NULL;
+ return path;
+}
+
+int create_symref(const char *git_HEAD, const char *refs_heads_master)
+{
+ const char *lockpath;
+ char ref[1000];
+ int fd, len, written;
+
+#if USE_SYMLINK_HEAD
+ if (!only_use_symrefs) {
+ unlink(git_HEAD);
+ if (!symlink(refs_heads_master, git_HEAD))
+ return 0;
+ fprintf(stderr, "no symlink - falling back to symbolic ref\n");
+ }
+#endif
+
+ len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
+ if (sizeof(ref) <= len) {
+ error("refname too long: %s", refs_heads_master);
+ return -1;
+ }
+ lockpath = mkpath("%s.lock", git_HEAD);
+ fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
+ written = write(fd, ref, len);
+ close(fd);
+ if (written != len) {
+ unlink(lockpath);
+ error("Unable to write to %s", lockpath);
+ return -2;
+ }
+ if (rename(lockpath, git_HEAD) < 0) {
+ unlink(lockpath);
+ error("Unable to create %s", git_HEAD);
+ return -3;
+ }
+ return 0;
+}
+
+int read_ref(const char *filename, unsigned char *sha1)
+{
+ if (resolve_ref(filename, sha1, 1))
+ return 0;
+ return -1;
}
static int do_for_each_ref(const char *base, int (*fn)(const char *path, const unsigned char *sha1))
break;
continue;
}
- if (read_ref(path, sha1) < 0)
+ if (read_ref(git_path("%s", path), sha1) < 0)
continue;
if (!has_sha1_file(sha1))
continue;
int head_ref(int (*fn)(const char *path, const unsigned char *sha1))
{
unsigned char sha1[20];
- if (!read_ref("HEAD", sha1))
+ if (!read_ref(git_path("HEAD"), sha1))
return fn("HEAD", sha1);
return 0;
}
return ret;
}
-static int read_ref_file(const char *filename, unsigned char *sha1) {
- int fd = open(filename, O_RDONLY);
- char hex[41];
- if (fd < 0) {
- return error("Couldn't open %s\n", filename);
- }
- if ((read(fd, hex, 41) < 41) ||
- (hex[40] != '\n') ||
- get_sha1_hex(hex, sha1)) {
- error("Couldn't read a hash from %s\n", filename);
- close(fd);
- return -1;
- }
- close(fd);
- return 0;
-}
-
int get_ref_sha1(const char *ref, unsigned char *sha1)
{
- char *filename;
- int retval;
+ const char *filename;
+
if (check_ref_format(ref))
return -1;
- filename = ref_file_name(ref);
- retval = read_ref_file(filename, sha1);
- free(filename);
- return retval;
+ filename = git_path("refs/%s", ref);
+ return read_ref(filename, sha1);
}
static int lock_ref_file(const char *filename, const char *lock_filename,
return error("Couldn't open lock file for %s: %s",
filename, strerror(errno));
}
- retval = read_ref_file(filename, current_sha1);
+ retval = read_ref(filename, current_sha1);
if (old_sha1) {
if (retval) {
close(fd);
return retval;
}
+/*
+ * Make sure "ref" is something reasonable to have under ".git/refs/";
+ * We do not like it if:
+ *
+ * - any path component of it begins with ".", or
+ * - it has double dots "..", or
+ * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
+ * - it ends with a "/".
+ */
+
+static inline int bad_ref_char(int ch)
+{
+ return (((unsigned) ch) <= ' ' ||
+ ch == '~' || ch == '^' || ch == ':');
+}
+
int check_ref_format(const char *ref)
{
- char *middle;
- if (ref[0] == '.' || ref[0] == '/')
- return -1;
- middle = strchr(ref, '/');
- if (!middle || !middle[1])
- return -1;
- if (strchr(middle + 1, '/'))
- return -1;
- return 0;
+ int ch, level;
+ const char *cp = ref;
+
+ level = 0;
+ while (1) {
+ while ((ch = *cp++) == '/')
+ ; /* tolerate duplicated slashes */
+ if (!ch)
+ return -1; /* should not end with slashes */
+
+ /* we are at the beginning of the path component */
+ if (ch == '.' || bad_ref_char(ch))
+ return -1;
+
+ /* scan the rest of the path component */
+ while ((ch = *cp++) != 0) {
+ if (bad_ref_char(ch))
+ return -1;
+ if (ch == '/')
+ break;
+ if (ch == '.' && *cp == '.')
+ return -1;
+ }
+ level++;
+ if (!ch) {
+ if (level < 2)
+ return -1; /* at least of form "heads/blah" */
+ return 0;
+ }
+ }
}
int write_ref_sha1_unlocked(const char *ref, const unsigned char *sha1)