mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-08-17 09:20:28 +03:00
To ensure this happens without duplicating code, we allow forcing a StringBuilder object to only use the inline buffer, so the code in the AK/Format.cpp file doesn't need to deal with different underlying storage types (expandable or inline-fixed) at all.
117 lines
4.2 KiB
C++
117 lines
4.2 KiB
C++
/*
|
|
* Copyright (c) 2023, Liav A. <liavalb@hotmail.co.il>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <AK/Array.h>
|
|
#include <AK/StringBuilder.h>
|
|
#include <AK/StringView.h>
|
|
#include <AK/TypedTransfer.h>
|
|
#include <AK/Userspace.h>
|
|
|
|
#ifdef KERNEL
|
|
# include <Kernel/Arch/SafeMem.h>
|
|
# include <Kernel/Arch/SmapDisabler.h>
|
|
# include <Kernel/Memory/MemorySections.h>
|
|
#endif
|
|
|
|
namespace AK {
|
|
|
|
template<size_t Size>
|
|
class FixedStringBuffer {
|
|
public:
|
|
[[nodiscard]] static ErrorOr<FixedStringBuffer<Size>> vformatted(StringView fmtstr, AK::TypeErasedFormatParams& params)
|
|
requires(Size < StringBuilder::inline_capacity)
|
|
{
|
|
StringBuilder builder { StringBuilder::UseInlineCapacityOnly::Yes };
|
|
TRY(AK::vformat(builder, fmtstr, params));
|
|
FixedStringBuffer<Size> buffer {};
|
|
buffer.store_characters(builder.string_view());
|
|
return buffer;
|
|
}
|
|
|
|
template<typename... Parameters>
|
|
[[nodiscard]] static ErrorOr<FixedStringBuffer<Size>> formatted(CheckedFormatString<Parameters...>&& fmtstr, Parameters const&... parameters)
|
|
requires(Size < StringBuilder::inline_capacity)
|
|
{
|
|
AK::VariadicFormatParams<AK::AllowDebugOnlyFormatters::No, Parameters...> variadic_format_parameters { parameters... };
|
|
return vformatted(fmtstr.view(), variadic_format_parameters);
|
|
}
|
|
|
|
void store_characters(StringView characters)
|
|
{
|
|
// NOTE: Only store the characters up to the first null terminator
|
|
// because we don't care about any further characters.
|
|
// This matches some expected behavior in the Kernel code, because
|
|
// technically userspace programs could send a syscall argument with
|
|
// multiple null terminators - we only care about the *first* chunk up to
|
|
// the first null terminator, if present at all.
|
|
size_t stored_length = 0;
|
|
for (; stored_length < min(Size, characters.length()); stored_length++) {
|
|
if (characters[stored_length] == '\0')
|
|
break;
|
|
m_storage[stored_length] = characters[stored_length];
|
|
}
|
|
m_stored_length = stored_length;
|
|
// NOTE: Fill the rest of the array bytes with zeroes, just to be
|
|
// on the safe side.
|
|
// Technically, it means that a sent StringView could occupy the
|
|
// entire storage without any null terminators and that's OK as well.
|
|
for (size_t index = m_stored_length; index < Size; index++)
|
|
m_storage[index] = '\0';
|
|
}
|
|
|
|
#ifdef KERNEL
|
|
ErrorOr<void> copy_characters_from_user(Userspace<char const*> user_str, size_t user_str_size)
|
|
{
|
|
if (user_str_size > Size)
|
|
return EFAULT;
|
|
bool is_user = Kernel::Memory::is_user_range(user_str.vaddr(), user_str_size);
|
|
if (!is_user)
|
|
return EFAULT;
|
|
Kernel::SmapDisabler disabler;
|
|
void* fault_at;
|
|
ssize_t length = Kernel::safe_strnlen(user_str.unsafe_userspace_ptr(), user_str_size, fault_at);
|
|
if (length < 0) {
|
|
dbgln("FixedStringBuffer::copy_characters_into_storage({:p}, {}) failed at {} (strnlen)", static_cast<void const*>(user_str.unsafe_userspace_ptr()), user_str_size, VirtualAddress { fault_at });
|
|
return EFAULT;
|
|
}
|
|
if (!Kernel::safe_memcpy(m_storage.data(), user_str.unsafe_userspace_ptr(), (size_t)length, fault_at)) {
|
|
dbgln("FixedStringBuffer::copy_characters_into_storage({:p}, {}) failed at {} (memcpy)", static_cast<void const*>(user_str.unsafe_userspace_ptr()), user_str_size, VirtualAddress { fault_at });
|
|
return EFAULT;
|
|
}
|
|
m_stored_length = (size_t)length;
|
|
for (size_t index = m_stored_length; index < Size; index++)
|
|
m_storage[index] = '\0';
|
|
return {};
|
|
}
|
|
#endif
|
|
|
|
Span<u8> storage()
|
|
{
|
|
return m_storage.span();
|
|
}
|
|
StringView representable_view() const { return StringView(m_storage.data(), m_stored_length); }
|
|
|
|
size_t fixed_length() const { return Size; }
|
|
size_t stored_length() const { return m_stored_length; }
|
|
|
|
FixedStringBuffer()
|
|
{
|
|
m_storage.fill(0);
|
|
}
|
|
|
|
private:
|
|
Array<u8, Size> m_storage;
|
|
size_t m_stored_length { 0 };
|
|
};
|
|
|
|
}
|
|
|
|
#if USING_AK_GLOBALLY
|
|
using AK::FixedStringBuffer;
|
|
#endif
|