1 files changed, 62 insertions, 0 deletions
diff --git a/Kernel/Syscalls/realpath.cpp b/Kernel/Syscalls/realpath.cpp
new file mode 100644
index 0000000000..5dbbb103db
--- /dev/null
+++ b/Kernel/Syscalls/realpath.cpp
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/StringView.h>
+#include <Kernel/FileSystem/Custody.h>
+#include <Kernel/FileSystem/VirtualFileSystem.h>
+#include <Kernel/Process.h>
+
+namespace Kernel {
+
+int Process::sys$realpath(const Syscall::SC_realpath_params* user_params)
+{
+    REQUIRE_PROMISE(rpath);
+
+    Syscall::SC_realpath_params params;
+    if (!validate_read_and_copy_typed(&params, user_params))
+        return -EFAULT;
+
+    if (!validate_write(params.buffer.data, params.buffer.size))
+        return -EFAULT;
+
+    auto path = get_syscall_path_argument(params.path);
+    if (path.is_error())
+        return path.error();
+
+    auto custody_or_error = VFS::the().resolve_path(path.value(), current_directory());
+    if (custody_or_error.is_error())
+        return custody_or_error.error();
+    auto& custody = custody_or_error.value();
+    auto absolute_path = custody->absolute_path();
+
+    if (absolute_path.length() + 1 > params.buffer.size)
+        return -ENAMETOOLONG;
+
+    copy_to_user(params.buffer.data, absolute_path.characters(), absolute_path.length() + 1);
+    return 0;
+};
+
+}