From 0b924c5c23a89760ddecf8d8f6baa19333f9b667 Mon Sep 17 00:00:00 2001
From: Paul Cristian Sarbu <paul.cristian.sarbu@huawei.com>
Date: Tue, 30 May 2023 17:57:21 +0200
Subject: filesystem: Add logic for handling (non-upwards) symlinks

---
 src/utils/cpp/path.hpp | 13 +++++++++++++
 1 file changed, 13 insertions(+)

(limited to 'src/utils/cpp/path.hpp')

diff --git a/src/utils/cpp/path.hpp b/src/utils/cpp/path.hpp
index d872535e..a9fb08e5 100644
--- a/src/utils/cpp/path.hpp
+++ b/src/utils/cpp/path.hpp
@@ -16,6 +16,7 @@
 #define INCLUDED_SRC_UTILS_CPP_PATH_HPP
 
 #include <filesystem>
+#include <sstream>
 
 [[nodiscard]] static inline auto ToNormalPath(std::filesystem::path const& p)
     -> std::filesystem::path {
@@ -29,4 +30,16 @@
     return n;
 }
 
+/// \brief Perform a non-upwards condition check on the given path.
+/// A path is non-upwards if it is relative and it never references any other
+/// path on a higher level in the directory tree than itself.
+[[nodiscard]] static auto PathIsNonUpwards(
+    std::filesystem::path const& path) noexcept -> bool {
+    if (path.is_absolute()) {
+        return false;
+    }
+    // check non-upwards condition
+    return *path.lexically_normal().begin() != "..";
+}
+
 #endif
-- 
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