Cross-Platform Service Programming Diary Ep.2 - Inter-Process Communication (IPC) Previously The previous article implemented unified log management. This article implements inter-process message communication, i.e., IPC. Analysis Windows On Windows, inter-process communication is primarily achieved through Pipes. Pipes are further divided into Named Pipes and Anonymous Pipes. Anonymous pipes are unidirectional and are typically used for communication between a parent and child process[2]. Named pipes, however, can be unidirectional or duplex and support one-to-many communication[3]. As the name implies, the only way to identify a named pipe is by its name, so two processes can communicate as long as they connect to the named pipe with the same name. We need to achieve bidirectional communication between processes, so we use named pipes. The general idea is: a process starts in server mode (receiver), creates a thread, creates a named pipe, and listens for messages within the pipe. When the pipe is connected, it reads data from it; when a process starts as a sender, it attempts to connect to a pipe with the same name and writes the message content. Linux On Linux, sockets are typically used for inter-process communication. However, unlike listening on a port, IPC usually involves listening on a sock file[5]. Common service applications like the Docker daemon and MySQL use this method. Thus, the general idea is as follows: a process started in server mode creates a socket listener and waits to receive messages from it; the sender connects to the socket and sends a message. Similar to the name of the named pipe mentioned above, the socket maps to a unique .sock file. The sender just needs to open this file to send the message. (In practice, it's not opened in the conventional file manner but using socket-specific methods[5].) Code Implementation Initialization To use a common main codebase, I used the same approach as the previous article, differentiating system types via macro definitions, placing the Windows and Linux code in the header files service-windows.h and service-linux.h respectively: #ifdef _WIN32 #include "service-windows.h" #elif defined(__linux__) #include "service-linux.h" #endif When the receiver process starts, it creates a thread to handle message reception (using std::thread as the multithreading library): thread_bind = std::thread(bind_thread_main); Listener Section Windows On Windows, we simply attempt to read data from a named pipe with a specified name. Because the pipe is set to blocking mode (i.e., PIPE_WAIT is set in the DWORD dwPipeMode parameter of CreateNamedPipe below), ConnectNamedPipe will be blocking, so there's no need to worry about performance loss from constant looping. void bind_thread_main() { while (!exit_requested.load()) { HANDLE hPipe = CreateNamedPipe( PIPE_NAME, PIPE_ACCESS_DUPLEX, PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT, PIPE_UNLIMITED_INSTANCES, 1024, // Output buffer size 1024, // Input buffer size 0, // Default timeout NULL); if (hPipe == INVALID_HANDLE_VALUE) { service_log.push(LEVEL_WARN, "Failed to create pipe: %d", GetLastError()); continue; } if (ConnectNamedPipe(hPipe, NULL) || GetLastError() == ERROR_PIPE_CONNECTED) { char buffer[1024]; DWORD bytesRead; if (ReadFile(hPipe, buffer, sizeof(buffer) - 1, &bytesRead, NULL)) { buffer[bytesRead] = '\0'; m_queueMsg.push(buffer); service_log.push(LEVEL_VERBOSE, "Message received: %s", buffer); } FlushFileBuffers(hPipe); DisconnectNamedPipe(hPipe); CloseHandle(hPipe); } else { CloseHandle(hPipe); } } } Linux To prevent creation failure, the code attempts to delete any leftover sock file that wasn't cleaned up before creation, i.e., unlink(SOCKET_PATH) in the code. SOCKET_PATH is a global variable defining the path to the socket file. When creating the socket, the family is specified as AF_UNIX, indicating a UNIX socket (the .sock file type; for network sockets it would be AF_INET). The timeval code sets a timeout limit. If the accept function waits longer than the set SOCKET_TIMEOUT (in seconds), it will automatically stop blocking and return an error. After creating the socket, proceed with the normal setup for binding and listening. void bind_thread_main() { unlink(SOCKET_PATH); int server_fd = socket(AF_UNIX, SOCK_STREAM, 0); if (server_fd == -1) { service_log.push(LEVEL_FATAL, "Failed to create socket"); exit_requested.store(true); return; } struct timeval tv; tv.tv_sec = SOCKET_TIMEOUT; tv.tv_usec = 0; setsockopt(server_fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)); sockaddr_un addr{}; addr.sun_family = AF_UNIX; strncpy(addr.sun_path, SOCKET_PATH, sizeof(addr.sun_path) - 1); if (bind(server_fd, (sockaddr*)&addr, sizeof(addr)) == -1) { service_log.push(LEVEL_FATAL, "Bind failed"); close(server_fd); exit_requested.store(true); return; } if (listen(server_fd, 5) == -1) { service_log.push(LEVEL_FATAL, "Listen failed"); close(server_fd); exit_requested.store(true); return; } while (!exit_requested.load()) { int client_fd = accept(server_fd, nullptr, nullptr); if (client_fd != -1) { char buffer[1024]; int bytes_read = read(client_fd, buffer, sizeof(buffer) - 1); if (bytes_read > 0) { buffer[bytes_read] = '\0'; m_queueMsg.push(buffer); service_log.push(LEVEL_VERBOSE, "Message received: %s", buffer); } close(client_fd); } else { if (errno == EWOULDBLOCK || errno == EAGAIN) { continue; } service_log.push(LEVEL_WARN, "Failed to accept socket connection"); } } } After reading a message, both code versions save the message to the blocking queue m_queueMsg. Sender Section Windows Open the specified pipe and write the message content: bool send_message(const std::string& msg) { if (!WaitNamedPipe(PIPE_NAME, NMPWAIT_WAIT_FOREVER)) { service_log.push(LEVEL_ERROR, "Failed to find valid pipe: %d", GetLastError()); return false; } HANDLE hPipe = CreateFile( PIPE_NAME, GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL); if (hPipe == INVALID_HANDLE_VALUE) { service_log.push(LEVEL_ERROR, "Failed to connect: %d", GetLastError()); return false; } DWORD bytesWritten; if (WriteFile(hPipe, msg.c_str(), (DWORD)msg.size(), &bytesWritten, NULL)) { service_log.push(LEVEL_VERBOSE, "Message sent: %s", msg.c_str()); CloseHandle(hPipe); return true; } else { service_log.push(LEVEL_ERROR, "Message (%s) send failed: %d", msg.c_str(),GetLastError()); CloseHandle(hPipe); return false; } } Linux Similarly, connect to the socket and send the data: bool send_message(const std::string& msg) { int sock = socket(AF_UNIX, SOCK_STREAM, 0); if (sock == -1) { service_log.push(LEVEL_ERROR, "Failed to create socket"); return false; } sockaddr_un addr{}; addr.sun_family = AF_UNIX; strncpy(addr.sun_path, SOCKET_PATH, sizeof(addr.sun_path) - 1); if (connect(sock, (sockaddr*)&addr, sizeof(addr)) == -1) { service_log.push(LEVEL_ERROR, "Connect failed"); close(sock); return false; } if (write(sock, msg.c_str(), msg.size()) == -1) { service_log.push(LEVEL_ERROR, "Message send failed: %s", msg.c_str()); close(sock); return false; } else { service_log.push(LEVEL_VERBOSE, "Message sent success: %s", msg.c_str()); close(sock); return true; } } Cleanup There's little to clean up on Windows, but on Linux, the socket file needs to be deleted: unlink(SOCKET_PATH); Demo Screenshots Windows Linux Sample code download: IPCTest.zip References: https://learn.microsoft.com/zh-cn/windows/win32/ipc/pipes https://learn.microsoft.com/zh-cn/windows/win32/ipc/anonymous-pipes https://learn.microsoft.com/zh-cn/windows/win32/ipc/named-pipes https://www.cnblogs.com/alantu2018/p/8493809.html https://blog.csdn.net/dog250/article/details/100998838

Cross-Platform Service Programming Diary Ep.1 - Unified Logging Management A while ago, on a whim, I decided to write my own management program for a cross-platform console service-class application I was using, in order to add some features. Thus, I designed a simple service operation flow. {alert type="warning"} The views and solutions in this series of articles are designed by me based on my existing knowledge combined with assistance from DeepSeek. They have not been rigorously tested and do not guarantee feasibility or stability for use in production environments. {/alert} General Approach Roughly divided into several threads, used for: Logging Target application instance management (potentially more than one thread) Listening for IPC messages Processing received IPC messages (main process) This article focuses on the logging part. Design Rationale Why dedicate a separate thread to logging? My consideration is that since it's inherently a multi-threaded architecture, a unified logging module is necessary. If each thread prints independently, it's highly likely that two threads could write to the file or output to the console simultaneously, causing log chaos. Therefore, the general idea for logging is: Define a queue to store log content and level. Create a thread that continuously takes elements from the queue, deciding whether to print to the console or output to a file based on the set log level. External components push log content to the queue. Some Detailed Considerations Ensure portability by using the STL library as much as possible, e.g., using std::thread instead of pthread. Ensure thread safety, requiring protection of relevant variables with mutexes or similar mechanisms. Make the thread wait when the log queue is empty; thought of writing a blocking queue similar to Java's BlockingQueue. Specify a log level; only logs with a level meeting or exceeding this threshold will be saved or printed. Implement variadic arguments via va_list to give the logging function a usage experience similar to sprintf. Start Coding With the above approach, the overall coding becomes quite simple. BlockingQueue Got lazy here, let DeepSeek write this part directly To implement a multi-thread-safe blocking queue where calling front() blocks until another thread adds an element, we can combine a mutex (std::mutex) and a condition variable (std::condition_variable) to synchronize thread operations. Code Implementation Mutex (std::mutex) All operations on the queue (push、front、pop、empty) need to acquire the lock first, ensuring only one thread can modify the queue at a time and avoiding data races. Condition Variable (std::condition_variable) When front() is called and the queue is empty, the thread releases the lock and blocks via cv_.wait(), until another thread calls push() to add an element and wakes up one waiting thread via cv_.notify_one(). cv_.wait() needs to be used with std::unique_lock and automatically releases the lock while waiting to avoid deadlocks. Uses a predicate check ([this] { return !queue_.empty(); }) to prevent spurious wakeups. Element Retrieval and Removal front() returns a copy of the front element (not a reference), ensuring the caller gets the data after the queue's lock is released, avoiding dangling references. pop() must be called explicitly to remove the element, ensuring controllable queue state. #include <queue> // queue #include <mutex> // mutex #include <condition_variable> // condition_variable template<typename T> class BlockingQueue { public: // Add an element to the queue void push(const T& item) { std::lock_guard<std::mutex> lock(mtx_); queue_.push(item); cv_.notify_one(); // Notify one waiting thread } // Get the front element (blocks until queue is not empty) T front() { std::unique_lock<std::mutex> lock(mtx_); cv_.wait(lock, [this] { return !queue_.empty(); }); // Block until queue not empty return queue_.front(); } // Get and remove the front element T take() { std::unique_lock<std::mutex> lock(mtx_); cv_.wait(lock, [this] { return !queue_.empty(); }); T item = std::move(queue_.front()); // Use move semantics to avoid copy queue_.pop(); return item; } // Remove the front element (requires external call, non-blocking) void pop() { std::lock_guard<std::mutex> lock(mtx_); if (!queue_.empty()) { queue_.pop(); } } // Check if the queue is empty bool empty() const { std::lock_guard<std::mutex> lock(mtx_); return queue_.empty(); } private: mutable std::mutex mtx_; // Mutex std::condition_variable cv_; // Condition variable std::queue<T> queue_; // Internal queue }; Log Class Log.h #pragma once #include <iostream> #include <fstream> #include <cstring> #include <thread> #include <chrono> #include <mutex> #include <cstdio> #include <cstdarg> #include <atomic> #include "BlockingQueue.h" enum LogLevel { LEVEL_VERBOSE,LEVEL_INFO,LEVEL_WARN,LEVEL_ERROR,LEVEL_FATAL,LEVEL_OFF }; struct LogMsg { short m_LogLevel; std::string m_strTimestamp; std::string m_strLogMsg; }; class Log { private: std::ofstream m_ofLogFile; // Log file output stream std::mutex m_lockFile; // File operation mutex std::thread m_threadMain; // Background log processing thread BlockingQueue<LogMsg> m_msgQueue; // Thread-safe blocking queue short m_levelLog, m_levelPrint; // File and console log level thresholds std::atomic<bool> m_exit_requested{ false }; // Thread exit flag std::string getTime(); // Get current timestamp std::string level2str(short level, bool character_only); // Level to string void logThread(); // Background thread function public: Log(short default_loglevel = LEVEL_WARN, short default_printlevel = LEVEL_INFO); ~Log(); void push(short level, const char* msg, ...); // Add log (supports formatting) void set_level(short loglevel, short printlevel); // Set log levels bool open(std::string filename); // Open log file bool close(); // Close log file }; Log.cpp #include "Log.h" std::string Log::getTime() { using sc = std::chrono::system_clock; std::time_t t = sc::to_time_t(sc::now()); char buf[20]; #ifdef _WIN32 std::tm timeinfo; localtime_s(&timeinfo,&t); sprintf_s(buf, "%04d.%02d.%02d-%02d:%02d:%02d", timeinfo.tm_year + 1900, timeinfo.tm_mon + 1, timeinfo.tm_mday, timeinfo.tm_hour, timeinfo.tm_min, timeinfo.tm_sec ); #else strftime(buf, 20, "%Y.%m.%d-%H:%M:%S", localtime(&t)); #endif return buf; } std::string Log::level2str(short level, bool character_only) { switch (level) { case LEVEL_VERBOSE: return character_only ? "V" : "Verbose"; case LEVEL_WARN: return character_only ? "W" : "Warning"; case LEVEL_ERROR: return character_only ? "E" : "Error"; case LEVEL_FATAL: return character_only ? "F" : "Fatal"; } return character_only ? "I" : "Info"; } void Log::logThread() { while (true) { LogMsg front = m_msgQueue.take(); // Block until a message arrives // Handle file writing if (front.m_LogLevel >= m_levelLog) { std::lock_guard<std::mutex> lock(m_lockFile); // RAII manage lock if (m_ofLogFile) { m_ofLogFile << front.m_strTimestamp << ' ' << level2str(front.m_LogLevel, true) << ": " << front.m_strLogMsg << std::endl; } } // Handle console printing if (front.m_LogLevel >= m_levelPrint) { printf("%s %s: %s\n", front.m_strTimestamp.c_str(), level2str(front.m_LogLevel, true).c_str(), front.m_strLogMsg.c_str()); } // Check exit condition: queue is empty and flag is true if (m_exit_requested.load() && m_msgQueue.empty()) break; } return; } Log::Log(short default_loglevel, short default_printlevel) { set_level(default_loglevel, default_printlevel); m_threadMain = std::thread(&Log::logThread, this); } Log::~Log() { m_exit_requested.store(true); m_msgQueue.push({ LEVEL_INFO, getTime(), "Exit." }); // Wake potentially blocked thread if (m_threadMain.joinable()) m_threadMain.join(); close(); // Ensure file is closed } void Log::push(short level, const char* msg, ...) { va_list args; va_start(args, msg); const int len = vsnprintf(nullptr, 0, msg, args); va_end(args); if (len < 0) return; std::vector<char> buf(len + 1); va_start(args, msg); vsnprintf(buf.data(), buf.size(), msg, args); va_end(args); m_msgQueue.push({level,getTime(),buf.data()}); } void Log::set_level(short loglevel, short printlevel) { m_levelLog = loglevel; m_levelPrint = printlevel; } bool Log::open(std::string filename) { m_lockFile.lock(); m_ofLogFile.open(filename.c_str(), std::ios::out); m_lockFile.unlock(); return (bool)m_ofLogFile; } bool Log::close() { m_lockFile.lock(); m_ofLogFile.close(); m_lockFile.unlock(); return false; } Explanation Class/Structure Explanation LogLevel Enum Defines log levels: VERBOSE, INFO, WARN, ERROR, FATAL, OFF。 OFF should not be used as a level for recorded logs, only for setting the threshold when needing to disable all logging. LogMsg Struct Encapsulates a log message: m_LogLevel: The log level. m_strTimestamp: Timestamp string. m_strLogMsg: The log content. Member Variable Explanation Variable Explanation m_ofLogFile File output stream for writing to the log file. m_lockFile Mutex protecting file operations. m_threadMain Background thread handling consumption of log messages. m_msgQueue Blocking queue storing pending log messages. m_levelLog Minimum log level for writing to file (messages with level >= this are recorded). m_levelPrint Minimum log level for printing to console. m_exit_requested Atomic flag controlling log thread exit. Function Explanation Function Explanation getTime Gets the current timestamp string (cross-platform implementation). level2str Converts log level to string (e.g., LEVEL_INFO → "I" or "Info"). logThread Background thread function: consumes queue messages, writes to file or prints. Constructor Initializes log levels, starts the background thread. Destructor Sets exit flag, waits for thread to finish, ensures remaining messages are processed. push Formats log message (supports variadic arguments) and pushes to the queue. set_level Dynamically sets the log and print levels. open/close Opens/closes the log file. Complete code and test sample download: demo.zip

Querying DNS Records Using WINAPI in C++ This article has been migrated from an old blog (a kind of cyber reincarnation). Corrections are welcome if any errors are found. Background Multiple access endpoints were configured for an API to handle service unavailability in certain regions where access might be blocked. Initially, I considered creating a file within the website to store node information, but this approach proved unfeasible because regions with connectivity issues couldn't retrieve information about other endpoints. Then, the idea emerged to use DNS resolution records - specifically, a TXT record - to store the relevant node data for querying. Implementation Research After searching on Bing, I found that most existing articles use sockets to directly send query packets. However, these methods typically only retrieve A and CNAME records, which wasn't suitable for my needs. Finally, I focused on the DnsQuery function mentioned in MSDN and found a sample article: Use DnsQuery to Resolve Host Names. Function Analysis According to the official documentation, the function requires the header windns.h and needs to link against the libraries Ws2_32.lib and Dnsapi.lib. The function parameters are as follows: DNS_STATUS DnsQuery_A( [in] PCSTR pszName, [in] WORD wType, [in] DWORD Options, [in, out, optional] PVOID pExtra, [out, optional] PDNS_RECORD *ppQueryResults, [out, optional] PVOID *pReserved ); Parameter Explanation: pszName is the hostname to query. wType is the query type, such as A record, CNAME, TXT, etc. Specific constants are documented by MSDN: DNS Constants. Options literally means the query method. I used DNS_QUERY_STANDARD directly. Details can also be found in the documentation: DNS Constants. pExtra and pReserved can simply be set to NULL. ppQueryResultsis a pointer to the query results, of type PDNS_RECORD*. This requires passing a reference to the variable's value. Return value: The DNS_STATUS type. If the query fails, it returns the corresponding error code from Winerror.h. Usage Understanding the usage method made it straightforward: My TXT record domain is test.iyoroy.cn. The query code is as follows: PDNS_RECORD pDnsRecord; DNS_STATUS QueryRet = DnsQuery(L"test.iyoroy.cn", DNS_TYPE_TEXT, DNS_QUERY_STANDARD, NULL, &pDnsRecord, NULL); if (QueryRet) { MessageBox(GhWnd, L"DNS query failed!\r\nWill use the default node.", L"Warning", MB_ICONERROR | MB_OK); } std::wstring strQueryRes = *pDnsRecord->Data.TXT.pStringArray; // This is the query result. Successfully implemented the functionality. Postscript TXT records automatically filter out spaces and line breaks. Therefore, I chose to store Base64 encoded data in the record, decode it when used, and then split it using stringstream. For Base64 decoding, I adapted the code from this article: Base64 Encoding and Decoding in C++. Below is the rewritten decoding function using wide characters: {collapse} {collapse-item label="Expand Code"} //Function: Base64 Decryption static const std::wstring base64_chars = L"ABCDEFGHIJKLMNOPQRSTUVWXYZ" L"abcdefghijklmnopqrstuvwxyz" L"0123456789+/"; static inline bool is_base64(wchar_t c) { return (isalnum(c) || (c == L'+') || (c == L'/')); } std::wstring base64_decode(std::wstring const& encoded_string) { int in_len = encoded_string.size(); int i = 0; int j = 0; int in_ = 0; wchar_t char_array_4[4], char_array_3[3]; std::wstring ret; while (in_len-- && (encoded_string[in_] != L'=') && is_base64(encoded_string[in_])) { char_array_4[i++] = encoded_string[in_]; in_++; if (i == 4) { for (i = 0; i < 4; i++) char_array_4[i] = base64_chars.find(char_array_4[i]); char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4); char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2); char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3]; for (i = 0; (i < 3); i++) ret += char_array_3[i]; i = 0; } } if (i) { for (j = i; j < 4; j++) char_array_4[j] = 0; for (j = 0; j < 4; j++) char_array_4[j] = base64_chars.find(char_array_4[j]); char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4); char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2); char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3]; for (j = 0; (j < i - 1); j++) ret += char_array_3[j]; } return ret; } Splitting the decoded string: wstringstream wDnsRec(base64_decode(*pDnsRecord->Data.TXT.pStringArray)); wstring wNodes[16]; unsigned int nNodes = 0; while (wDnsRec >> wNodes[nNodes]) nNodes++; {/collapse-item} {/collapse} After that, selecting an available node becomes possible. Reference Articles: https://learn.microsoft.com/en-us/previous-versions/troubleshoot/windows/win32/use-dnsquery-resolve-host-names https://learn.microsoft.com/en-us/windows/win32/dns/dns-constants https://blog.csdn.net/sky04/article/details/6881649

Adding KernelSU Support to Android 4.9 Kernel Introduction KernelSU has been available for a while. Officially, it only supports GKI kernels, but the project provides integration guidelines for non-GKI kernels. The Xiaomi Mi 8 Pro, which I use, is based on the Android 4.9 kernel. Testing showed that directly using KernelSU's integration script caused issues, so I'm documenting the process here. Special thanks to: Developer Tomsec for providing the 4.9 kernel fix. Prerequisites Android Kernel source code. Here, we use LineageOS/android_kernel_xiaomi_sdm845 Network access to GitHub AnyKernel3 source code. You can refer to this repository: YoriInstitute/AnyKernel3-equuleus Cross-compiler. You can refer to this repository: https://github.com/YoriInstitute/AnyKernel3-equuleus/blob/13/.github/workflows/build.yml#L21-L23 A build server Let's Start Configuring the build environment won't be detailed here. You can integrate it directly into the boot.img when building the ROM, or compile it separately as an AnyKernel3 flashable zip. This guide uses the AnyKernel3 approach. Download Kernel Source Code and Cross-Compiler git clone https://github.com/KaguraiYoRoy/android_kernel_xiaomi_sdm845 -b lineage-20 sdm845 #Kernel source git clone https://android.googlesource.com/platform/prebuilts/clang/host/linux-x86 --depth=1 -b android-13.0.0_r43 clang #Clang git clone https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9 -b android-10.0.0_r32 --depth=1 #aarch64 GCC git clone https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9 -b android-10.0.0_r32 --depth=1 #arm GCC Different kernels might require different cross-compilers. Please adjust according to your specific case. {alert type="info"} When cloning the kernel source, --depth=1 wasn't used initially to facilitate easier cherry-picking later. If you plan to manually modify the kernel source instead of using cherry-pick, you can add this parameter to significantly reduce download time. {/alert} Modify Kernel Source Refer to the following two commits: https://github.com/OnlyTomInSecond/android_kernel_xiaomi_sdm845/commit/7862fd2c14b69a1a346b7c699f8370e2de423eef commit b5853fb7cefdc8a2e160cb73512dc6b51569fa66 Author: OnlyTomInSecond <[email protected]> Date: Wed Apr 5 11:05:12 2023 +0800 kernelsu: allow init exec ksud under nosuid Change-Id: I8aa6e6d3cbee1addd5da9bb48b4c08ce91f9db81 diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 4abba0e1674d..693f2ac03352 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2320,7 +2320,10 @@ static int check_nnp_nosuid(const struct linux_binprm *bprm, { int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS); int nosuid = !mnt_may_suid(bprm->file->f_path.mnt); - int rc; + int rc, error; + static u32 ksu_sid; + char *secdata; + u32 seclen; if (!nnp && !nosuid) return 0; /* neither NNP nor nosuid */ @@ -2328,6 +2331,18 @@ static int check_nnp_nosuid(const struct linux_binprm *bprm, if (new_tsec->sid == old_tsec->sid) return 0; /* No change in credentials */ + if(!ksu_sid){ + security_secctx_to_secid("u:r:su:s0", strlen("u:r:su:s0"), &ksu_sid); + } + error = security_secid_to_secctx(old_tsec->sid, &secdata, &seclen); + if (!error) { + rc = strcmp("u:r:init:s0",secdata); + security_release_secctx(secdata, seclen); + if(rc == 0 && new_tsec->sid == ksu_sid){ + return 0; + } + } + /* * The only transitions we permit under NNP or nosuid * are transitions to bounded SIDs, i.e. SIDs that are https://github.com/OnlyTomInSecond/android_kernel_xiaomi_sdm845/commit/81d7168f2f01e6aba0932a4787119fbc541eba58 commit 8bfe4d4de25650505798cba0a5a20db4b2ab7dd6 Author: OnlyTomInSecond <[email protected]> Date: Thu Oct 19 17:55:23 2023 +0800 Kernelsu: add path_umount implementation. Change-Id: I3b0273e9857c51cc3215afab0d2cebe0dff38cfb diff --git a/fs/namespace.c b/fs/namespace.c index 21fd423b19cf..219a501337b0 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1711,6 +1711,38 @@ static inline bool may_mandlock(void) } #endif +static int can_umount(const struct path *path, int flags) +{ + struct mount *mnt = real_mount(path->mnt); + + if (!may_mount()) + return -EPERM; + if (path->dentry != path->mnt->mnt_root) + return -EINVAL; + if (!check_mnt(mnt)) + return -EINVAL; + if (mnt->mnt.mnt_flags & MNT_LOCKED) /* Check optimistically */ + return -EINVAL; + if (flags & MNT_FORCE && !capable(CAP_SYS_ADMIN)) + return -EPERM; + return 0; +} + +// caller is responsible for flags being sane +int path_umount(struct path *path, int flags) +{ + struct mount *mnt = real_mount(path->mnt); + int ret; + + ret = can_umount(path, flags); + if (!ret) + ret = do_umount(mnt, flags); + + /* we mustn't call path_put() as that would clear mnt_expiry_mark */ + dput(path->dentry); + mntput_no_expire(mnt); + return ret; +} /* * Now umount can handle mount points as well as block devices. * This is important for filesystems which use unnamed block devices. Solution Source: Tomsec Enable KPROBE Support Open your kernel's defconfig file and add the following three lines: CONFIG_KPROBES=y CONFIG_HAVE_KPROBES=y CONFIG_KPROBE_EVENTS=y Integrate KernelSU This step is the same as the official ksu guide. Execute the following command in the kernel root directory: curl -LSs "https://raw.githubusercontent.com/tiann/KernelSU/main/kernel/setup.sh" | bash -s v0.9.5 {alert type="warning"} Note: The highest version of KernelSU supporting non-GKI kernels is v0.9.5. Do not use a higher version tag, or the build will fail. {/alert} Write the AnyKernel3 Script Download AnyKernel3 and modify anykernel.sh according to the README. You can refer to my repository for modifications: Repository: https://github.com/iYoRoy-AOSP-Institute/AnyKernel3-equuleus/blob/14/anykernel.sh {collapse} {collapse-item label="Expand Code"} commit 3b46e03e0ffdd52bbb3f51b45b0ff649a407d1a5 Author: KaguraiYoRoy <[email protected]> Date: Sat Sep 9 02:41:54 2023 +0000 anykernel.sh: modify for equuleus diff --git a/anykernel.sh b/anykernel.sh old mode 100755 new mode 100644 index 367d29f..c950ce7 --- a/anykernel.sh +++ b/anykernel.sh @@ -4,23 +4,17 @@ ### AnyKernel setup # global properties properties() { ' -kernel.string=ExampleKernel by osm0sis @ xda-developers +kernel.string=Xiaomi 8 Pro Kernel by Kagura iYoRoy @ iYoRoy Studio do.devicecheck=1 do.modules=0 -do.systemless=1 +do.systemless=0 do.cleanup=1 do.cleanuponabort=0 -device.name1=maguro -device.name2=toro -device.name3=toroplus -device.name4=tuna -device.name5= -supported.versions= +device.name1=equuleus +supported.versions=13 supported.patchlevels= -supported.vendorpatchlevels= '; } # end properties - ### AnyKernel install ## boot files attributes boot_attributes() { @@ -29,7 +23,7 @@ set_perm_recursive 0 0 750 750 $ramdisk/init* $ramdisk/sbin; } # end attributes # boot shell variables -block=/dev/block/platform/omap/omap_hsmmc.0/by-name/boot; +block=/dev/block/bootdevice/by-name/boot; is_slot_device=0; ramdisk_compression=auto; patch_vbmeta_flag=auto; @@ -41,32 +35,26 @@ patch_vbmeta_flag=auto; dump_boot; # use split_boot to skip ramdisk unpack, e.g. for devices with init_boot ramdisk # init.rc -backup_file init.rc; -replace_string init.rc "cpuctl cpu,timer_slack" "mount cgroup none /dev/cpuctl cpu" "mount cgroup none /dev/cpuctl cpu,timer_slack"; +#backup_file init.rc; +#replace_string init.rc "cpuctl cpu,timer_slack" "mount cgroup none /dev/cpuctl cpu" "mount cgroup none /dev/cpuctl cpu,timer_slack"; # init.tuna.rc -backup_file init.tuna.rc; -insert_line init.tuna.rc "nodiratime barrier=0" after "mount_all /fstab.tuna" "\tmount ext4 /dev/block/platform/omap/omap_hsmmc.0/by-name/userdata /data remount nosuid nodev noatime nodiratime barrier=0"; -append_file init.tuna.rc "bootscript" init.tuna; +#backup_file init.tuna.rc; +#insert_line init.tuna.rc "nodiratime barrier=0" after "mount_all /fstab.tuna" "\tmount ext4 /dev/block/platform/omap/omap_hsmmc.0/by-name/userdata /data remount nosuid nodev noatime nodiratime barrier=0"; +#append_file init.tuna.rc "bootscript" init.tuna; # fstab.tuna -backup_file fstab.tuna; -patch_fstab fstab.tuna /system ext4 options "noatime,barrier=1" "noatime,nodiratime,barrier=0"; -patch_fstab fstab.tuna /cache ext4 options "barrier=1" "barrier=0,nomblk_io_submit"; -patch_fstab fstab.tuna /data ext4 options "data=ordered" "nomblk_io_submit,data=writeback"; -append_file fstab.tuna "usbdisk" fstab; +#backup_file fstab.tuna; +#patch_fstab fstab.tuna /system ext4 options "noatime,barrier=1" "noatime,nodiratime,barrier=0"; +#patch_fstab fstab.tuna /cache ext4 options "barrier=1" "barrier=0,nomblk_io_submit"; +#patch_fstab fstab.tuna /data ext4 options "data=ordered" "nomblk_io_submit,data=writeback"; +#append_file fstab.tuna "usbdisk" fstab; write_boot; # use flash_boot to skip ramdisk repack, e.g. for devices with init_boot ramdisk ## end boot install -## init_boot files attributes -#init_boot_attributes() { -#set_perm_recursive 0 0 755 644 $ramdisk/*; -#set_perm_recursive 0 0 750 750 $ramdisk/init* $ramdisk/sbin; -#} # end attributes - -# init_boot shell variables +## init_boot shell variables #block=init_boot; #is_slot_device=1; #ramdisk_compression=auto; @@ -98,13 +86,7 @@ write_boot; # use flash_boot to skip ramdisk repack, e.g. for devices with init_ ## end vendor_kernel_boot install -## vendor_boot files attributes -#vendor_boot_attributes() { -#set_perm_recursive 0 0 755 644 $ramdisk/*; -#set_perm_recursive 0 0 750 750 $ramdisk/init* $ramdisk/sbin; -#} # end attributes - -# vendor_boot shell variables +## vendor_boot shell variables #block=vendor_boot; #is_slot_device=1; #ramdisk_compression=auto; @@ -118,4 +100,3 @@ write_boot; # use flash_boot to skip ramdisk repack, e.g. for devices with init_ #write_boot; # use flash_boot to skip ramdisk repack, e.g. for dtb on devices with hdr v4 but no vendor_kernel_boot ## end vendor_boot install - {/collapse-item} {/collapse} Compile the Kernel It's recommended to refer to online tutorials for this step, as compilation parameter settings can vary for different kernels. I've packaged the compilation process into a shell script for reference: {alert type="info"} Please replace $WORKSPACE below with your own working directory. {/alert} #!/bin/bash ARCH="arm64" CLANG_DIR="$WORKSPACE/clang/clang-r450784d" #Clang directory CC="$CLANG_DIR/bin/clang" export PATH="$CLANG_DIR/bin:$PATH" OUT_DIR="./out" CLANG_TRIPLE="aarch64-linux-gnu-" CROSS_COMPILE="$WORKSPACE/aarch64-linux-android-4.9/bin/aarch64-linux-androidkernel-" #aarch64 GCC CROSS_COMPILE_ARM32="$WORKSPACE/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel-" #arm GCC CC_ADDITION_FLAGS="AR=llvm-ar NM=llvm-nm OBJCOPY=llvm-objcopy OBJDUMP=llvm-objdump STRIP=llvm-strip LLVM_IAS=1 LLVM=1 LD=ld.lld" ANYKERNEL_DIR="$WORKSPACE/AnyKernel3" #Location of your prepared AnyKernel3 directory THREAD=$(nproc --all) args="-j$THREAD O=$OUT_DIR ARCH=$ARCH CROSS_COMPILE=$CROSS_COMPILE CROSS_COMPILE_ARM32=$CROSS_COMPILE_ARM32 CC=$CC CLANG_TRIPLE=$CLANG_TRIPLE $CC_ADDITION_FLAGS" ### Compile Kernel ### echo "[+]Args: $args" echo "[+}Generate .config" make equuleus_user_defconfig $args #Here 'equuleus_user_defconfig' is the defconfig file for the equuleus kernel. Replace it with your kernel's config file name. echo "[+]Begin Build" make $args ### Compilation Complete ### ### Create AnyKernel3 Zip ### cd $WORKSPACE/sdm845/KernelSU KSU_VERSION='v0.9.5' TARGET_KERNEL="Mi8Pro-LineageKernel-KernelSU$KSU_VERSION" #Kernel filename echo "[+]KernelSU Version: $KSU_VERSION" echo "[+]Target file: $TARGET_KERNEL" cd $WORKSPACE/AnyKernel3 cp $WORKSPACE/sdm845/out/arch/arm64/boot/Image . cp $WORKSPACE/sdm845/out/arch/arm64/boot/Image.gz . cp $WORKSPACE/sdm845/out/arch/arm64/boot/Image.gz-dtb . OUTPUT_FILE=${TARGET_KERNEL}-$(date +"%y.%m.%d").zip echo "[+]Output: $OUTPUT_FILE" zip -r $OUTPUT_FILE * mv $OUTPUT_FILE $WORKSPACE Flashing Use a recovery like TWRP to flash the zip. Automatically Compile the Kernel using GitHub Actions Refer to this YAML file for workflow setup: https://github.com/iYoRoy-AOSP-Institute/AnyKernel3-equuleus/blob/13/.github/workflows/build.yml {collapse} {collapse-item label="Expand Code"} name: Build AnyKernel on: push: schedule: - cron: '0 0 * * 0' jobs: build: runs-on: ubuntu-latest steps: - name: Download run: | echo "Free space:" df -h cd $GITHUB_WORKSPACE echo "[+]Install packages:" sudo apt update sudo apt install zip bc bison build-essential ccache curl flex g++-multilib gcc-multilib git gnupg gperf imagemagick lib32ncurses5-dev lib32readline-dev lib32z1-dev liblz4-tool libncurses5-dev libncurses5 libsdl1.2-dev libssl-dev libwxgtk3.0-gtk3-dev libxml2 libxml2-utils lzop pngcrush rsync schedtool squashfs-tools xsltproc zip zlib1g-dev make unzip python-is-python3 echo "[+]Clone dependencies:" git clone https://github.com/KaguraiYoRoy/android_kernel_xiaomi_sdm845 -b lineage-20 sdm845 git clone https://android.googlesource.com/platform/prebuilts/clang/host/linux-x86 --depth=1 -b android-13.0.0_r43 clang git clone https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9 -b android-10.0.0_r32 --depth=1 git clone https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9 -b android-10.0.0_r32 --depth=1 git clone https://github.com/KaguraiYoRoy/AnyKernel3-equuleus AnyKernel3 --depth=1 - name: Setup KernelSU run: | cd $GITHUB_WORKSPACE/sdm845 curl -LSs "https://raw.githubusercontent.com/tiann/KernelSU/main/kernel/setup.sh" | bash -s main - name: Build Kernel run: | cd $GITHUB_WORKSPACE/sdm845 ARCH="arm64" CLANG_DIR="$GITHUB_WORKSPACE/clang/clang-r450784d" CC="$CLANG_DIR/bin/clang" export PATH="$CLANG_DIR/bin:$PATH" OUT_DIR="./out" CLANG_TRIPLE="aarch64-linux-gnu-" CROSS_COMPILE="$GITHUB_WORKSPACE/aarch64-linux-android-4.9/bin/aarch64-linux-androidkernel-" CROSS_COMPILE_ARM32="$GITHUB_WORKSPACE/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel-" CC_ADDITION_FLAGS="AR=llvm-ar NM=llvm-nm OBJCOPY=llvm-objcopy OBJDUMP=llvm-objdump STRIP=llvm-strip LLVM_IAS=1 LLVM=1 LD=ld.lld" THREAD=$(nproc --all) ANYKERNEL_DIR="$GITHUB_WORKSPACE/AnyKernel3" args="-j$THREAD O=$OUT_DIR ARCH=$ARCH CROSS_COMPILE=$CROSS_COMPILE CROSS_COMPILE_ARM32=$CROSS_COMPILE_ARM32 CC=$CC CLANG_TRIPLE=$CLANG_TRIPLE $CC_ADDITION_FLAGS" echo "[+]Args: $args" echo "[+}Generate .config" make equuleus_user_defconfig $args echo "[+]Begin Build" make $args - name: Compress run: | cd $GITHUB_WORKSPACE/sdm845/KernelSU KSU_VERSION=`expr 10000 + \`git rev-list --count HEAD\` + 200` TARGET_KERNEL="Mi8Pro-LineageKernel-KernelSU$KSU_VERSION" echo "[+]KernelSU Version: $KSU_VERSION" echo "[+]Target file: $TARGET_KERNEL" cd $GITHUB_WORKSPACE/AnyKernel3 cp $GITHUB_WORKSPACE/sdm845/out/arch/arm64/boot/Image . cp $GITHUB_WORKSPACE/sdm845/out/arch/arm64/boot/Image.gz . cp $GITHUB_WORKSPACE/sdm845/out/arch/arm64/boot/Image.gz-dtb . OUTPUT_FILE=${TARGET_KERNEL}-$(date +"%y.%m.%d").zip echo "[+]Output: $OUTPUT_FILE" zip -r $OUTPUT_FILE * mv $OUTPUT_FILE $GITHUB_WORKSPACE - name: Release uses: softprops/action-gh-release@v1 with: tag_name: Android13 files: | Mi8Pro*.zip I definitely won't tell you that the script above was also extracted from here x {/collapse-item} {/collapse}