ladybird/Kernel/Syscalls/readlink.cpp
2021-09-05 17:55:43 +02:00

32 lines
1 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/StringView.h>
#include <Kernel/FileSystem/VirtualFileSystem.h>
#include <Kernel/Process.h>
namespace Kernel {
KResultOr<FlatPtr> Process::sys$readlink(Userspace<const Syscall::SC_readlink_params*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
REQUIRE_PROMISE(rpath);
auto params = TRY(copy_typed_from_user(user_params));
auto path = TRY(get_syscall_path_argument(params.path));
auto description = TRY(VirtualFileSystem::the().open(path->view(), O_RDONLY | O_NOFOLLOW_NOERROR, 0, current_directory()));
if (!description->metadata().is_symlink())
return EINVAL;
auto link_target = TRY(description->read_entire_file());
auto size_to_copy = min(link_target->size(), params.buffer.size);
TRY(copy_to_user(params.buffer.data, link_target->data(), size_to_copy));
// Note: we return the whole size here, not the copied size.
return link_target->size();
}
}