skyline/app/src/main/cpp/skyline/kernel/ipc.cpp

#include "ipc.h"
#include "types/KProcess.h"

namespace skyline::kernel::ipc {
    IpcBuffer::IpcBuffer(u64 address, size_t size, IpcBufferType type) : address(address), size(size), type(type) {}

    InputBuffer::InputBuffer(kernel::ipc::BufferDescriptorX *xBuf) : IpcBuffer(xBuf->Address(), xBuf->size, IpcBufferType::X) {}

    InputBuffer::InputBuffer(kernel::ipc::BufferDescriptorABW *aBuf, IpcBufferType type) : IpcBuffer(aBuf->Address(), aBuf->Size(), type) {}

    OutputBuffer::OutputBuffer(kernel::ipc::BufferDescriptorABW *bBuf, IpcBufferType type) : IpcBuffer(bBuf->Address(), bBuf->Size(), type) {}

    OutputBuffer::OutputBuffer(kernel::ipc::BufferDescriptorC *cBuf) : IpcBuffer(cBuf->address, cBuf->size, IpcBufferType::C) {}

    IpcRequest::IpcRequest(bool isDomain, const DeviceState &state) : isDomain(isDomain), state(state) {
        u8 *tls = state.process->GetPointer<u8>(state.thread->tls);
        u8 *pointer = tls;

        header = reinterpret_cast<CommandHeader *>(pointer);
        pointer += sizeof(CommandHeader);

        if (header->handleDesc) {
            handleDesc = reinterpret_cast<HandleDescriptor *>(pointer);
            pointer += sizeof(HandleDescriptor) + (handleDesc->sendPid ? sizeof(u64) : 0);
            for (uint index = 0; handleDesc->copyCount > index; index++) {
                copyHandles.push_back(*reinterpret_cast<KHandle *>(pointer));
                pointer += sizeof(KHandle);
            }
            for (uint index = 0; handleDesc->moveCount > index; index++) {
                moveHandles.push_back(*reinterpret_cast<KHandle *>(pointer));
                pointer += sizeof(KHandle);
            }
        }

        for (uint index = 0; header->xNo > index; index++) {
            auto bufX = reinterpret_cast<BufferDescriptorX *>(pointer);
            if (bufX->Address()) {
                inputBuf.emplace_back(bufX);
                state.logger->Debug("Buf X #{} AD: 0x{:X} SZ: 0x{:X} CTR: {}", index, u64(bufX->Address()), u16(bufX->size), u16(bufX->Counter()));
            }
            pointer += sizeof(BufferDescriptorX);
        }

        for (uint index = 0; header->aNo > index; index++) {
            auto bufA = reinterpret_cast<BufferDescriptorABW *>(pointer);
            if (bufA->Address()) {
                inputBuf.emplace_back(bufA);
                state.logger->Debug("Buf A #{} AD: 0x{:X} SZ: 0x{:X}", index, u64(bufA->Address()), u64(bufA->Size()));
            }
            pointer += sizeof(BufferDescriptorABW);
        }

        for (uint index = 0; header->bNo > index; index++) {
            auto bufB = reinterpret_cast<BufferDescriptorABW *>(pointer);
            if (bufB->Address()) {
                outputBuf.emplace_back(bufB);
                state.logger->Debug("Buf B #{} AD: 0x{:X} SZ: 0x{:X}", index, u64(bufB->Address()), u64(bufB->Size()));
            }
            pointer += sizeof(BufferDescriptorABW);
        }

        for (uint index = 0; header->wNo > index; index++) {
            auto bufW = reinterpret_cast<BufferDescriptorABW *>(pointer);
            if (bufW->Address()) {
                inputBuf.emplace_back(bufW, IpcBufferType::W);
                outputBuf.emplace_back(bufW, IpcBufferType::W);
                state.logger->Debug("Buf W #{} AD: 0x{:X} SZ: 0x{:X}", index, u64(bufW->Address()), u16(bufW->Size()));
            }
            pointer += sizeof(BufferDescriptorABW);
        }

        constexpr auto ipcPaddingSum = 0x10; // The sum of the padding surrounding the data payload

        u64 padding = ((((reinterpret_cast<u64>(pointer) - reinterpret_cast<u64>(tls)) - 1U) & ~(ipcPaddingSum - 1U)) + ipcPaddingSum + (reinterpret_cast<u64>(tls) - reinterpret_cast<u64>(pointer))); // Calculate the amount of padding at the front
        pointer += padding;

        if (isDomain && (header->type == CommandType::Request)) {
            domain = reinterpret_cast<DomainHeaderRequest *>(pointer);
            pointer += sizeof(DomainHeaderRequest);

            payload = reinterpret_cast<PayloadHeader *>(pointer);
            pointer += sizeof(PayloadHeader);

            cmdArg = pointer;
            cmdArgSz = domain->payloadSz - sizeof(PayloadHeader);
            pointer += domain->payloadSz;

            for (uint index = 0; domain->inputCount > index; index++) {
                domainObjects.push_back(*reinterpret_cast<KHandle *>(pointer));
                pointer += sizeof(KHandle);
            }
        } else {
            payload = reinterpret_cast<PayloadHeader *>(pointer);
            pointer += sizeof(PayloadHeader);

            cmdArg = pointer;
            cmdArgSz = (header->rawSize * sizeof(u32)) - (ipcPaddingSum + sizeof(PayloadHeader));
            pointer += cmdArgSz;
        }

        payloadOffset = cmdArg;

        constexpr auto sfciMagic = 0x49434653; //!< SFCI in reverse, present in received IPC messages

        if (payload->magic != sfciMagic && header->type != CommandType::Control)
            state.logger->Debug("Unexpected Magic in PayloadHeader: 0x{:X}", u32(payload->magic));

        pointer += ipcPaddingSum - padding;

        if (header->cFlag == BufferCFlag::SingleDescriptor) {
            auto bufC = reinterpret_cast<BufferDescriptorC *>(pointer);
            if (bufC->address) {
                outputBuf.emplace_back(bufC);
                state.logger->Debug("Buf C: AD: 0x{:X} SZ: 0x{:X}", u64(bufC->address), u16(bufC->size));
            }
        } else if (header->cFlag > BufferCFlag::SingleDescriptor) {
            for (uint index = 0; (static_cast<u8>(header->cFlag) - 2) > index; index++) { // (cFlag - 2) C descriptors are present
                auto bufC = reinterpret_cast<BufferDescriptorC *>(pointer);
                if (bufC->address) {
                    outputBuf.emplace_back(bufC);
                    state.logger->Debug("Buf C #{} AD: 0x{:X} SZ: 0x{:X}", index, u64(bufC->address), u16(bufC->size));
                }
                pointer += sizeof(BufferDescriptorC);
            }
        }

        if (header->type == CommandType::Request) {
            state.logger->Debug("Header: Input No: {}, Output No: {}, Raw Size: {}", inputBuf.size(), outputBuf.size(), u64(cmdArgSz));
            if (header->handleDesc)
                state.logger->Debug("Handle Descriptor: Send PID: {}, Copy Count: {}, Move Count: {}", bool(handleDesc->sendPid), u32(handleDesc->copyCount), u32(handleDesc->moveCount));
            if (isDomain)
                state.logger->Debug("Domain Header: Command: {}, Input Object Count: {}, Object ID: 0x{:X}", domain->command, domain->inputCount, domain->objectId);
            state.logger->Debug("Command ID: 0x{:X}", u32(payload->value));
        }
    }

    IpcResponse::IpcResponse(bool isDomain, const DeviceState &state) : isDomain(isDomain), state(state) {}

    void IpcResponse::WriteResponse() {
        auto tls = state.process->GetPointer<u8>(state.thread->tls);
        u8 *pointer = tls;

        constexpr auto tlsIpcSize = 0x100; // The size of the IPC command buffer in a TLS slot
        memset(tls, 0, tlsIpcSize);

        constexpr auto ipcPaddingSum = 0x10; // The sum of the padding surrounding the data payload

        auto header = reinterpret_cast<CommandHeader *>(pointer);
        header->rawSize = static_cast<u32>((sizeof(PayloadHeader) + argVec.size() + (domainObjects.size() * sizeof(KHandle)) + ipcPaddingSum + (isDomain ? sizeof(DomainHeaderRequest) : 0)) / sizeof(u32)); // Size is in 32-bit units because Nintendo
        header->handleDesc = (!copyHandles.empty() || !moveHandles.empty());
        pointer += sizeof(CommandHeader);

        if (header->handleDesc) {
            auto handleDesc = reinterpret_cast<HandleDescriptor *>(pointer);
            handleDesc->copyCount = static_cast<u8>(copyHandles.size());
            handleDesc->moveCount = static_cast<u8>(moveHandles.size());
            pointer += sizeof(HandleDescriptor);

            for (unsigned int copyHandle : copyHandles) {
                *reinterpret_cast<KHandle *>(pointer) = copyHandle;
                pointer += sizeof(KHandle);
            }

            for (unsigned int moveHandle : moveHandles) {
                *reinterpret_cast<KHandle *>(pointer) = moveHandle;
                pointer += sizeof(KHandle);
            }
        }

        u64 padding = ((((reinterpret_cast<u64>(pointer) - reinterpret_cast<u64>(tls)) - 1U) & ~(ipcPaddingSum - 1U)) + ipcPaddingSum + (reinterpret_cast<u64>(tls) - reinterpret_cast<u64>(pointer))); // Calculate the amount of padding at the front
        pointer += padding;

        if (isDomain) {
            auto domain = reinterpret_cast<DomainHeaderResponse *>(pointer);
            domain->outputCount = static_cast<u32>(domainObjects.size());
            pointer += sizeof(DomainHeaderResponse);
        }

        constexpr auto sfcoMagic = 0x4F434653; // SFCO in reverse, IPC Response Magic

        auto payload = reinterpret_cast<PayloadHeader *>(pointer);
        payload->magic = sfcoMagic;
        payload->version = 1;
        payload->value = errorCode;
        pointer += sizeof(PayloadHeader);

        if (!argVec.empty())
            memcpy(pointer, argVec.data(), argVec.size());
        pointer += argVec.size();

        if (isDomain) {
            for (auto &domainObject : domainObjects) {
                *reinterpret_cast<KHandle *>(pointer) = domainObject;
                pointer += sizeof(KHandle);
            }
        }

        state.logger->Debug("Output: Raw Size: {}, Command ID: 0x{:X}, Copy Handles: {}, Move Handles: {}", u32(header->rawSize), u32(payload->value), copyHandles.size(), moveHandles.size());
    }
}