citra/src/core/hle/kernel/ipc.cpp
Subv 7cf7999e02 Kernel/IPC: Added a function to translate the IPC command buffer from one process to another.
Currently only CopyHandle, MoveHandle and CallingPid descriptors are implemented.
2017-11-06 10:46:12 -05:00

93 lines
3.6 KiB
C++

// Copyright 2017 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include "core/hle/ipc.h"
#include "core/hle/kernel/handle_table.h"
#include "core/hle/kernel/ipc.h"
#include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/memory.h"
#include "core/hle/kernel/process.h"
#include "core/hle/kernel/thread.h"
#include "core/memory.h"
namespace Kernel {
ResultCode TranslateCommandBuffer(SharedPtr<Thread> src_thread, SharedPtr<Thread> dst_thread,
VAddr src_address, VAddr dst_address) {
auto& src_process = src_thread->owner_process;
IPC::Header header;
// TODO(Subv): Replace by Memory::Read32 when possible.
Memory::ReadBlock(*src_process, src_address, &header.raw, sizeof(header.raw));
size_t untranslated_size = 1u + header.normal_params_size;
size_t command_size = untranslated_size + header.translate_params_size;
// Note: The real kernel does not check that the command length fits into the IPC buffer area.
ASSERT(command_size <= IPC::COMMAND_BUFFER_LENGTH);
std::array<u32, IPC::COMMAND_BUFFER_LENGTH> cmd_buf;
Memory::ReadBlock(*src_process, src_address, cmd_buf.data(), command_size * sizeof(u32));
size_t i = untranslated_size;
while (i < command_size) {
u32 descriptor = cmd_buf[i];
i += 1;
switch (IPC::GetDescriptorType(descriptor)) {
case IPC::DescriptorType::CopyHandle:
case IPC::DescriptorType::MoveHandle: {
u32 num_handles = IPC::HandleNumberFromDesc(descriptor);
// Note: The real kernel does not check that the number of handles fits into the command
// buffer before writing them, only after finishing.
if (i + num_handles > command_size) {
return ResultCode(ErrCodes::CommandTooLarge, ErrorModule::OS,
ErrorSummary::InvalidState, ErrorLevel::Status);
}
for (u32 j = 0; j < num_handles; ++j) {
Handle handle = cmd_buf[i];
SharedPtr<Object> object = nullptr;
// Perform pseudo-handle detection here because by the time this function is called,
// the current thread and process are no longer the ones which created this IPC
// request, but the ones that are handling it.
if (handle == CurrentThread) {
object = src_thread;
} else if (handle == CurrentProcess) {
object = src_process;
} else if (handle != 0) {
object = g_handle_table.GetGeneric(handle);
if (descriptor == IPC::DescriptorType::MoveHandle) {
g_handle_table.Close(handle);
}
}
if (object == nullptr) {
// Note: The real kernel sets invalid translated handles to 0 in the target
// command buffer.
cmd_buf[i++] = 0;
continue;
}
auto result = g_handle_table.Create(std::move(object));
cmd_buf[i++] = result.ValueOr(0);
}
break;
}
case IPC::DescriptorType::CallingPid: {
cmd_buf[i++] = src_process->process_id;
break;
}
default:
UNIMPLEMENTED_MSG("Unsupported handle translation: 0x%08X", descriptor);
}
}
Memory::WriteBlock(*dst_thread->owner_process, dst_address, cmd_buf.data(),
command_size * sizeof(u32));
return RESULT_SUCCESS;
}
} // namespace Kernel