From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 22 Aug 2022 09:36:12 +0000 (+0200)
Subject: chase-symlinks: add chase_symlinks_and_access() helper
X-Git-Tag: v252-rc1~377^2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2b2caea21df4f5c2b91888c037b9bc04da40dec3;p=thirdparty%2Fsystemd.git

chase-symlinks: add chase_symlinks_and_access() helper

This is similar to chase_symlinks_and_access() but wraps access() rather
than stat()
---

diff --git a/src/basic/chase-symlinks.c b/src/basic/chase-symlinks.c
index 2561da0e8c1..a5d89e13497 100644
--- a/src/basic/chase-symlinks.c
+++ b/src/basic/chase-symlinks.c
@@ -530,6 +530,49 @@ int chase_symlinks_and_stat(
         return 1;
 }
 
+int chase_symlinks_and_access(
+                const char *path,
+                const char *root,
+                ChaseSymlinksFlags chase_flags,
+                int access_mode,
+                char **ret_path,
+                int *ret_fd) {
+
+        _cleanup_close_ int path_fd = -1;
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        assert(path);
+
+        if (chase_flags & (CHASE_NONEXISTENT|CHASE_STEP))
+                return -EINVAL;
+
+        if (empty_or_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0 && !ret_fd) {
+                /* Shortcut this call if none of the special features of this call are requested */
+
+                if (faccessat(AT_FDCWD, path, access_mode, FLAGS_SET(chase_flags, CHASE_NOFOLLOW) ? AT_SYMLINK_NOFOLLOW : 0) < 0)
+                        return -errno;
+
+                return 1;
+        }
+
+        r = chase_symlinks(path, root, chase_flags, ret_path ? &p : NULL, &path_fd);
+        if (r < 0)
+                return r;
+        assert(path_fd >= 0);
+
+        r = access_fd(path_fd, access_mode);
+        if (r < 0)
+                return r;
+
+        if (ret_path)
+                *ret_path = TAKE_PTR(p);
+        if (ret_fd)
+                *ret_fd = TAKE_FD(path_fd);
+
+        return 1;
+}
+
 int chase_symlinks_and_fopen_unlocked(
                 const char *path,
                 const char *root,
diff --git a/src/basic/chase-symlinks.h b/src/basic/chase-symlinks.h
index 491138a698b..7e45b0cbab5 100644
--- a/src/basic/chase-symlinks.h
+++ b/src/basic/chase-symlinks.h
@@ -28,5 +28,5 @@ int chase_symlinks(const char *path_with_prefix, const char *root, ChaseSymlinks
 int chase_symlinks_and_open(const char *path, const char *root, ChaseSymlinksFlags chase_flags, int open_flags, char **ret_path);
 int chase_symlinks_and_opendir(const char *path, const char *root, ChaseSymlinksFlags chase_flags, char **ret_path, DIR **ret_dir);
 int chase_symlinks_and_stat(const char *path, const char *root, ChaseSymlinksFlags chase_flags, char **ret_path, struct stat *ret_stat, int *ret_fd);
-
+int chase_symlinks_and_access(const char *path, const char *root, ChaseSymlinksFlags chase_flags, int access_mode, char **ret_path, int *ret_fd);
 int chase_symlinks_and_fopen_unlocked(const char *path, const char *root, ChaseSymlinksFlags chase_flags, const char *open_flags, char **ret_path, FILE **ret_file);