basic: add readdir_no_dot and safe_glob functions

safe_glob filters out "." and "..".

This converts all users of glob_extend() and glob_exists() to safe_glob.

1 files changed, 40 insertions, 24 deletions

diff --git a/src/basic/glob-util.c b/src/basic/glob-util.c
index 007198c269..f611c42e4c 100644
--- a/src/basic/glob-util.c
+++ b/src/basic/glob-util.c
@@ -17,54 +17,70 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <dirent.h>
 #include <errno.h>
 #include <glob.h>
+#include <sys/types.h>
 
+#include "dirent-util.h"
 #include "glob-util.h"
 #include "macro.h"
+#include "path-util.h"
 #include "strv.h"
 
-int glob_exists(const char *path) {
-        _cleanup_globfree_ glob_t g = {};
+int safe_glob(const char *path, int flags, glob_t *pglob) {
         int k;
 
-        assert(path);
+        /* We want to set GLOB_ALTDIRFUNC ourselves, don't allow it to be set. */
+        assert(!(flags & GLOB_ALTDIRFUNC));
+
+        if (!pglob->gl_closedir)
+                pglob->gl_closedir = (void (*)(void *)) closedir;
+        if (!pglob->gl_readdir)
+                pglob->gl_readdir = (struct dirent *(*)(void *)) readdir_no_dot;
+        if (!pglob->gl_opendir)
+                pglob->gl_opendir = (void *(*)(const char *)) opendir;
+        if (!pglob->gl_lstat)
+                pglob->gl_lstat = lstat;
+        if (!pglob->gl_stat)
+                pglob->gl_stat = stat;
 
         errno = 0;
-        k = glob(path, GLOB_NOSORT|GLOB_BRACE, NULL, &g);
+        k = glob(path, flags | GLOB_ALTDIRFUNC, NULL, pglob);
 
         if (k == GLOB_NOMATCH)
-                return 0;
+                return -ENOENT;
         if (k == GLOB_NOSPACE)
                 return -ENOMEM;
         if (k != 0)
                 return errno > 0 ? -errno : -EIO;
+        if (strv_isempty(pglob->gl_pathv))
+                return -ENOENT;
 
-        return !strv_isempty(g.gl_pathv);
+        return 0;
 }
 
-int glob_extend(char ***strv, const char *path) {
+int glob_exists(const char *path) {
         _cleanup_globfree_ glob_t g = {};
         int k;
-        char **p;
 
-        errno = 0;
-        k = glob(path, GLOB_NOSORT|GLOB_BRACE, NULL, &g);
+        assert(path);
 
-        if (k == GLOB_NOMATCH)
-                return -ENOENT;
-        if (k == GLOB_NOSPACE)
-                return -ENOMEM;
-        if (k != 0)
-                return errno > 0 ? -errno : -EIO;
-        if (strv_isempty(g.gl_pathv))
-                return -ENOENT;
+        k = safe_glob(path, GLOB_NOSORT|GLOB_BRACE, &g);
+        if (k == -ENOENT)
+                return false;
+        if (k < 0)
+                return k;
+        return true;
+}
+
+int glob_extend(char ***strv, const char *path) {
+        _cleanup_globfree_ glob_t g = {};
+        int k;
 
-        STRV_FOREACH(p, g.gl_pathv) {
-                k = strv_extend(strv, *p);
-                if (k < 0)
-                        return k;
-        }
+        k = safe_glob(path, GLOB_NOSORT|GLOB_BRACE, &g);
+        if (k < 0)
+                return k;
 
-        return 0;
+        return strv_extend_strv(strv, g.gl_pathv, false);
 }