int tweak = shared_repository;
if (!(mode & S_IWUSR))
tweak &= ~0222;
- mode = (mode & ~0777) | tweak;
+ mode |= tweak;
} else {
/* Preserve old PERM_UMASK behaviour */
if (mode & S_IWUSR)
return 0;
}
-static const char *get_pwd_cwd(void)
-{
- static char cwd[PATH_MAX + 1];
- char *pwd;
- struct stat cwd_stat, pwd_stat;
- if (getcwd(cwd, PATH_MAX) == NULL)
- return NULL;
- pwd = getenv("PWD");
- if (pwd && strcmp(pwd, cwd)) {
- stat(cwd, &cwd_stat);
- if (!stat(pwd, &pwd_stat) &&
- pwd_stat.st_dev == cwd_stat.st_dev &&
- pwd_stat.st_ino == cwd_stat.st_ino) {
- strlcpy(cwd, pwd, PATH_MAX);
- }
- }
- return cwd;
-}
-
-const char *make_nonrelative_path(const char *path)
-{
- static char buf[PATH_MAX + 1];
-
- if (is_absolute_path(path)) {
- if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
- die ("Too long path: %.*s", 60, path);
- } else {
- const char *cwd = get_pwd_cwd();
- if (!cwd)
- die("Cannot determine the current working directory");
- if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
- die ("Too long path: %.*s", 60, path);
- }
- return buf;
-}
-
const char *make_relative_path(const char *abs, const char *base)
{
static char buf[PATH_MAX + 1];
strcpy(buf, abs + baselen);
return buf;
}
+
+/*
+ * path = absolute path
+ * buf = buffer of at least max(2, strlen(path)+1) bytes
+ * It is okay if buf == path, but they should not overlap otherwise.
+ *
+ * Performs the following normalizations on path, storing the result in buf:
+ * - Removes trailing slashes.
+ * - Removes empty components.
+ * - Removes "." components.
+ * - Removes ".." components, and the components the precede them.
+ * "" and paths that contain only slashes are normalized to "/".
+ * Returns the length of the output.
+ *
+ * Note that this function is purely textual. It does not follow symlinks,
+ * verify the existence of the path, or make any system calls.
+ */
+int normalize_absolute_path(char *buf, const char *path)
+{
+ const char *comp_start = path, *comp_end = path;
+ char *dst = buf;
+ int comp_len;
+ assert(buf);
+ assert(path);
+
+ while (*comp_start) {
+ assert(*comp_start == '/');
+ while (*++comp_end && *comp_end != '/')
+ ; /* nothing */
+ comp_len = comp_end - comp_start;
+
+ if (!strncmp("/", comp_start, comp_len) ||
+ !strncmp("/.", comp_start, comp_len))
+ goto next;
+
+ if (!strncmp("/..", comp_start, comp_len)) {
+ while (dst > buf && *--dst != '/')
+ ; /* nothing */
+ goto next;
+ }
+
+ memcpy(dst, comp_start, comp_len);
+ dst += comp_len;
+ next:
+ comp_start = comp_end;
+ }
+
+ if (dst == buf)
+ *dst++ = '/';
+
+ *dst = '\0';
+ return dst - buf;
+}
+
+/*
+ * path = Canonical absolute path
+ * prefix_list = Colon-separated list of absolute paths
+ *
+ * Determines, for each path in prefix_list, whether the "prefix" really
+ * is an ancestor directory of path. Returns the length of the longest
+ * ancestor directory, excluding any trailing slashes, or -1 if no prefix
+ * is an ancestor. (Note that this means 0 is returned if prefix_list is
+ * "/".) "/foo" is not considered an ancestor of "/foobar". Directories
+ * are not considered to be their own ancestors. path must be in a
+ * canonical form: empty components, or "." or ".." components are not
+ * allowed. prefix_list may be null, which is like "".
+ */
+int longest_ancestor_length(const char *path, const char *prefix_list)
+{
+ char buf[PATH_MAX+1];
+ const char *ceil, *colon;
+ int len, max_len = -1;
+
+ if (prefix_list == NULL || !strcmp(path, "/"))
+ return -1;
+
+ for (colon = ceil = prefix_list; *colon; ceil = colon+1) {
+ for (colon = ceil; *colon && *colon != ':'; colon++);
+ len = colon - ceil;
+ if (len == 0 || len > PATH_MAX || !is_absolute_path(ceil))
+ continue;
+ strlcpy(buf, ceil, len+1);
+ len = normalize_absolute_path(buf, buf);
+ /* Strip "trailing slashes" from "/". */
+ if (len == 1)
+ len = 0;
+
+ if (!strncmp(path, buf, len) &&
+ path[len] == '/' &&
+ len > max_len) {
+ max_len = len;
+ }
+ }
+
+ return max_len;
+}