Simple IPC for external control (#3345)

* add simple IPC protocol

to allow communication via stdin/stdout

* ipc: add PATCH_MEMORY command

enables patches & cheates

CMakeLists.txt

@@ -760,6 +760,8 @@ set(CORE src/core/aerolib/stubs.cpp
          src/core/file_format/trp.h
          src/core/file_sys/fs.cpp
          src/core/file_sys/fs.h
+         src/core/ipc/ipc.cpp
+         src/core/ipc/ipc.h
          src/core/loader/dwarf.cpp
          src/core/loader/dwarf.h
          src/core/loader/elf.cpp

src/common/memory_patcher.cpp

@@ -29,6 +29,7 @@ EXPORT uintptr_t g_eboot_address;
 uint64_t g_eboot_image_size;
 std::string g_game_serial;
 std::string patchFile;
+bool patches_applied = false;
 std::vector<patchInfo> pending_patches;
 
 std::string toHex(u64 value, size_t byteSize) {
@@ -119,6 +120,8 @@ std::string convertValueToHex(const std::string type, const std::string valueStr
     return result;
 }
 
+void ApplyPendingPatches();
+
 void OnGameLoaded() {
 
     if (!patchFile.empty()) {
@@ -377,20 +380,26 @@ void OnGameLoaded() {
 }
 
 void AddPatchToQueue(patchInfo patchToAdd) {
+    if (patches_applied) {
+        PatchMemory(patchToAdd.modNameStr, patchToAdd.offsetStr, patchToAdd.valueStr,
+                    patchToAdd.targetStr, patchToAdd.sizeStr, patchToAdd.isOffset,
+                    patchToAdd.littleEndian, patchToAdd.patchMask, patchToAdd.maskOffset);
+        return;
+    }
     pending_patches.push_back(patchToAdd);
 }
 
 void ApplyPendingPatches() {
-
+    patches_applied = true;
     for (size_t i = 0; i < pending_patches.size(); ++i) {
-        patchInfo currentPatch = pending_patches[i];
+        const patchInfo& currentPatch = pending_patches[i];
 
-        if (currentPatch.gameSerial != g_game_serial)
+        if (currentPatch.gameSerial != "*" && currentPatch.gameSerial != g_game_serial)
             continue;
 
-        PatchMemory(currentPatch.modNameStr, currentPatch.offsetStr, currentPatch.valueStr, "", "",
+        PatchMemory(currentPatch.modNameStr, currentPatch.offsetStr, currentPatch.valueStr,
-                    currentPatch.isOffset, currentPatch.littleEndian, currentPatch.patchMask,
+                    currentPatch.targetStr, currentPatch.sizeStr, currentPatch.isOffset,
-                    currentPatch.maskOffset);
+                    currentPatch.littleEndian, currentPatch.patchMask, currentPatch.maskOffset);
     }
 
     pending_patches.clear();

src/common/memory_patcher.h

@@ -30,19 +30,18 @@ struct patchInfo {
     std::string modNameStr;
     std::string offsetStr;
     std::string valueStr;
+    std::string targetStr;
+    std::string sizeStr;
     bool isOffset;
     bool littleEndian;
     PatchMask patchMask;
     int maskOffset;
 };
 
-extern std::vector<patchInfo> pending_patches;
-
 std::string convertValueToHex(const std::string type, const std::string valueStr);
 
 void OnGameLoaded();
 void AddPatchToQueue(patchInfo patchToAdd);
-void ApplyPendingPatches();
 
 void PatchMemory(std::string modNameStr, std::string offsetStr, std::string valueStr,
                  std::string targetStr, std::string sizeStr, bool isOffset, bool littleEndian,

src/core/ipc/ipc.cpp

@@ -0,0 +1,113 @@
+//  SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+//  SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "ipc.h"
+
+#include <iostream>
+#include <string>
+
+#include "common/memory_patcher.h"
+#include "common/thread.h"
+#include "common/types.h"
+
+/**
+ * Protocol summary:
+ * - IPC is enabled by setting the SHADPS4_ENABLE_IPC environment variable to "true"
+ * - Input will be stdin & output stderr
+ * - Strings are sent as UTF8
+ * - Each communication line is terminated by a newline character ('\n')
+ * - Each command parameter will be separated by a newline character ('\n'),
+ *   variadic commands will start sending the number of parameters after the cmd word.
+ *   Any ('\n') in the parameter must be escaped by a backslash ('\\n')
+ * - Numbers can be sent with any base. Must prefix the number with '0x' for hex,
+ *   '0b' for binary, or '0' for octal. Decimal numbers
+ *   will be sent without any prefix.
+ * - Output will be started by (';')
+ * - The IPC server(this) will send a block started by
+ *   #IPC_ENABLED
+ *   and ended by
+ *   #IPC_END
+ *   In between, it will send the current capabilities and commands before the emulator start
+ * - The IPC client(e.g., launcher) will send RUN then START to conintue the execution
+ **/
+
+/**
+ * Command list:
+ * - CAPABILITIES:
+ *   - ENABLE_MEMORY_PATCH: enables PATCH_MEMORY command
+ * - INPUT CMD:
+ *   - RUN: start the emulator execution
+ *   - START: start the game execution
+ *   - PATCH_MEMORY(
+ *       modName: str, offset: str, value: str,
+ *       target: str, size: str, isOffset: number, littleEndian: number,
+ *       patchMask: number, maskOffset: number
+ *     ): add a memory patch, check @ref MemoryPatcher::PatchMemory for details
+ * - OUTPUT CMD:
+ *   - N/A
+ **/
+
+void IPC::Init() {
+    const char* enabledEnv = std::getenv("SHADPS4_ENABLE_IPC");
+    enabled = enabledEnv && strcmp(enabledEnv, "true") == 0;
+    if (!enabled) {
+        return;
+    }
+
+    input_thread = std::jthread([this] {
+        Common::SetCurrentThreadName("IPC Read thread");
+        this->InputLoop();
+    });
+
+    std::cerr << ";#IPC_ENABLED\n";
+    std::cerr << ";ENABLE_MEMORY_PATCH\n";
+    std::cerr << ";#IPC_END\n";
+    std::cerr.flush();
+
+    const auto ok = run_semaphore.try_acquire_for(std::chrono::seconds(5));
+    if (!ok) {
+        std::cerr << "IPC: Failed to acquire run semaphore, closing process.\n";
+        exit(1);
+    }
+}
+
+void IPC::InputLoop() {
+    auto next_str = [&] -> const std::string& {
+        static std::string line_buffer;
+        do {
+            std::getline(std::cin, line_buffer, '\n');
+        } while (!line_buffer.empty() && line_buffer.back() == '\\');
+        return line_buffer;
+    };
+    auto next_u64 = [&] -> u64 {
+        auto& str = next_str();
+        return std::stoull(str, nullptr, 0);
+    };
+
+    while (true) {
+        auto& cmd = next_str();
+        if (cmd.empty()) {
+            continue;
+        }
+        if (cmd == "RUN") {
+            run_semaphore.release();
+        } else if (cmd == "START") {
+            start_semaphore.release();
+        } else if (cmd == "PATCH_MEMORY") {
+            MemoryPatcher::patchInfo entry;
+            entry.gameSerial = "*";
+            entry.modNameStr = next_str();
+            entry.offsetStr = next_str();
+            entry.valueStr = next_str();
+            entry.targetStr = next_str();
+            entry.sizeStr = next_str();
+            entry.isOffset = next_u64() != 0;
+            entry.littleEndian = next_u64() != 0;
+            entry.patchMask = static_cast<MemoryPatcher::PatchMask>(next_u64());
+            entry.maskOffset = static_cast<int>(next_u64());
+            MemoryPatcher::AddPatchToQueue(entry);
+        } else {
+            std::cerr << "UNKNOWN CMD: " << cmd << std::endl;
+        }
+    }
+}

src/core/ipc/ipc.h

@@ -0,0 +1,39 @@
+//  SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+//  SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "common/singleton.h"
+
+#include <semaphore>
+#include <thread>
+
+class IPC {
+    bool enabled{false};
+    std::jthread input_thread{};
+
+    std::binary_semaphore run_semaphore{0};
+    std::binary_semaphore start_semaphore{0};
+
+public:
+    static IPC& Instance() {
+        return *Common::Singleton<IPC>::Instance();
+    }
+
+    void Init();
+
+    operator bool() const {
+        return enabled;
+    }
+
+    [[nodiscard]] bool IsEnabled() const {
+        return enabled;
+    }
+
+    void WaitForStart() {
+        start_semaphore.acquire();
+    }
+
+private:
+    [[noreturn]] void InputLoop();
+};

src/core/linker.cpp

@@ -18,6 +18,7 @@
 #include "core/linker.h"
 #include "core/memory.h"
 #include "core/tls.h"
+#include "ipc/ipc.h"
 
 namespace Core {
 
@@ -115,6 +116,10 @@ void Linker::Execute(const std::vector<std::string> args) {
 
     main_thread.Run([this, module, args](std::stop_token) {
         Common::SetCurrentThreadName("GAME_MainThread");
+        if (auto& ipc = IPC::Instance()) {
+            ipc.WaitForStart();
+        }
+
         LoadSharedLibraries();
 
         // Simulate libSceGnmDriver initialization, which maps a chunk of direct memory.

src/main.cpp

@@ -12,6 +12,7 @@
 #include "common/memory_patcher.h"
 #include "common/path_util.h"
 #include "core/file_sys/fs.h"
+#include "core/ipc/ipc.h"
 #include "emulator.h"
 
 #ifdef _WIN32
@@ -22,6 +23,7 @@ int main(int argc, char* argv[]) {
 #ifdef _WIN32
     SetConsoleOutputCP(CP_UTF8);
 #endif
+    IPC::Instance().Init();
 
     // Load configurations
     const auto user_dir = Common::FS::GetUserPath(Common::FS::PathType::UserDir);
@@ -169,13 +171,12 @@ int main(int argc, char* argv[]) {
             break;
         } else {
             std::cerr << "Unknown argument: " << cur_arg << ", see --help for info.\n";
-            return 1;
         }
     }
 
     // If no game directory is set and no command line argument, prompt for it
     if (Config::getGameInstallDirs().empty()) {
-        std::cout << "Warning: No game folder set, please set it by calling shadps4"
+        std::cerr << "Warning: No game folder set, please set it by calling shadps4"
                      " with the --add-game-folder <folder_name> argument\n";
     }