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| 1 | +#include "monitordir.hpp" |
| 2 | + |
| 3 | +#include <cassert> |
| 4 | +#include <climits> |
| 5 | +#include <cstring> |
| 6 | +#include <fcntl.h> |
| 7 | +#include <iostream> |
| 8 | +#include <string> |
| 9 | +#include <sys/fanotify.h> |
| 10 | +#include <sys/stat.h> |
| 11 | +#include <thread> |
| 12 | +#include <unistd.h> |
| 13 | + |
| 14 | +#define BUF_SIZE 256 |
| 15 | + |
| 16 | +std::string getPathFromFd(int fd) |
| 17 | +{ |
| 18 | + char path[PATH_MAX]; |
| 19 | + char procfd_path[PATH_MAX]; |
| 20 | + snprintf(procfd_path, sizeof(procfd_path), "/proc/self/fd/%d", fd); |
| 21 | + ssize_t len = readlink(procfd_path, path, sizeof(path) - 1); |
| 22 | + if (len >= 0) { |
| 23 | + path[len] = '\0'; // 确保字符串以空字符结尾 |
| 24 | + return std::string(path); |
| 25 | + } |
| 26 | + return "Unknown"; // 读取失败时的处理 |
| 27 | +} |
| 28 | + |
| 29 | +std::string maskToString(unsigned long long mask) |
| 30 | +{ |
| 31 | + if ((mask & FAN_ACCESS) != 0U) { |
| 32 | + return "FAN_ACCESS: "; |
| 33 | + } |
| 34 | + if ((mask & FAN_MODIFY) != 0U) { |
| 35 | + return "FAN_MODIFY: "; |
| 36 | + } |
| 37 | + if ((mask & FAN_ATTRIB) != 0U) { |
| 38 | + return "FAN_ATTRIB: "; |
| 39 | + } |
| 40 | + if ((mask & FAN_CLOSE_WRITE) != 0U) { |
| 41 | + return "FAN_CLOSE_WRITE: "; |
| 42 | + } |
| 43 | + if ((mask & FAN_CLOSE_NOWRITE) != 0U) { |
| 44 | + return "FAN_CLOSE_NOWRITE: "; |
| 45 | + } |
| 46 | + if ((mask & FAN_OPEN) != 0U) { |
| 47 | + return "FAN_OPEN: "; |
| 48 | + } |
| 49 | + if ((mask & FAN_MOVED_FROM) != 0U) { |
| 50 | + return "FAN_MOVED_FROM: "; |
| 51 | + } |
| 52 | + if ((mask & FAN_MOVED_TO) != 0U) { |
| 53 | + return "FAN_MOVED_TO: "; |
| 54 | + } |
| 55 | + if ((mask & FAN_CREATE) != 0U) { |
| 56 | + return "FAN_CREATE: "; |
| 57 | + } |
| 58 | + if ((mask & FAN_DELETE) != 0U) { |
| 59 | + return "FAN_DELETE: "; |
| 60 | + } |
| 61 | + if ((mask & FAN_DELETE_SELF) != 0U) { |
| 62 | + return "FAN_DELETE_SELF: "; |
| 63 | + } |
| 64 | + if ((mask & FAN_MOVE_SELF) != 0U) { |
| 65 | + return "FAN_MOVE_SELF: "; |
| 66 | + } |
| 67 | + if ((mask & FAN_OPEN_EXEC) != 0U) { |
| 68 | + return "FAN_OPEN_EXEC: "; |
| 69 | + } |
| 70 | + if ((mask & FAN_Q_OVERFLOW) != 0U) { |
| 71 | + return "FAN_Q_OVERFLOW: "; |
| 72 | + } |
| 73 | + if ((mask & FAN_FS_ERROR) != 0U) { |
| 74 | + return "FAN_FS_ERROR: "; |
| 75 | + } |
| 76 | + if ((mask & FAN_OPEN_PERM) != 0U) { |
| 77 | + return "FAN_OPEN_PERM: "; |
| 78 | + } |
| 79 | + if ((mask & FAN_ACCESS_PERM) != 0U) { |
| 80 | + return "FAN_ACCESS_PERM: "; |
| 81 | + } |
| 82 | + if ((mask & FAN_OPEN_EXEC_PERM) != 0U) { |
| 83 | + return "FAN_OPEN_EXEC_PERM: "; |
| 84 | + } |
| 85 | + if ((mask & FAN_EVENT_ON_CHILD) != 0U) { |
| 86 | + return "FAN_EVENT_ON_CHILD: "; |
| 87 | + } |
| 88 | + if ((mask & FAN_RENAME) != 0U) { |
| 89 | + return "FAN_RENAME: "; |
| 90 | + } |
| 91 | + if ((mask & FAN_ONDIR) != 0U) { |
| 92 | + return "FAN_ONDIR: "; |
| 93 | + } |
| 94 | + if ((mask & FAN_CLOSE) != 0U) { |
| 95 | + return "FAN_CLOSE: "; |
| 96 | + } |
| 97 | + if ((mask & FAN_MOVE) != 0U) { |
| 98 | + return "FAN_MOVE: "; |
| 99 | + } |
| 100 | + return "Unknown mask " + std::to_string(mask) + ": "; |
| 101 | +} |
| 102 | + |
| 103 | +class MonitorDir::MonitorDirPrivate |
| 104 | +{ |
| 105 | +public: |
| 106 | + explicit MonitorDirPrivate(MonitorDir *q) |
| 107 | + : q_ptr(q) |
| 108 | + {} |
| 109 | + |
| 110 | + ~MonitorDirPrivate() = default; |
| 111 | + |
| 112 | + auto createFd() -> bool |
| 113 | + { |
| 114 | + mountFd = open(dir.c_str(), O_DIRECTORY | O_RDONLY); |
| 115 | + if (mountFd == -1) { |
| 116 | + perror("open"); |
| 117 | + exit(EXIT_FAILURE); |
| 118 | + } |
| 119 | + std::cout << "mountFd: " << mountFd << std::endl; |
| 120 | + |
| 121 | + unsigned int flags = FAN_CLASS_NOTIF | FAN_CLOEXEC | FAN_UNLIMITED_QUEUE |
| 122 | + | FAN_UNLIMITED_MARKS | FAN_ENABLE_AUDIT | FAN_REPORT_FID |
| 123 | + | FAN_REPORT_DFID_NAME; |
| 124 | + unsigned int event_f_flags = O_RDONLY | O_LARGEFILE | O_CLOEXEC; |
| 125 | + // 普通用户级别flags |
| 126 | + // flags = FAN_CLASS_NOTIF | FAN_CLOEXEC | FAN_REPORT_FID | FAN_REPORT_DFID_NAME; |
| 127 | + fanotifyFd = fanotify_init(flags, event_f_flags); |
| 128 | + if (fanotifyFd == -1) { |
| 129 | + perror("fanotify_init"); |
| 130 | + exit(EXIT_FAILURE); |
| 131 | + } |
| 132 | + std::cout << "fanotifyFd: " << fanotifyFd << std::endl; |
| 133 | + return true; |
| 134 | + } |
| 135 | + |
| 136 | + void closeFd() |
| 137 | + { |
| 138 | + if (mountFd != -1) { |
| 139 | + close(mountFd); |
| 140 | + mountFd = -1; |
| 141 | + } |
| 142 | + if (fanotifyFd != -1) { |
| 143 | + close(fanotifyFd); |
| 144 | + fanotifyFd = -1; |
| 145 | + } |
| 146 | + } |
| 147 | + |
| 148 | + auto addWatch() -> bool |
| 149 | + { |
| 150 | + // FAN_MARK_FILESYSTEM 全局监控，需要 CAP_SYS_ADMIN 能力，即 root 权限 |
| 151 | + unsigned int flags = FAN_MARK_ADD | FAN_MARK_FILESYSTEM; |
| 152 | + unsigned int mask = FAN_ACCESS | FAN_MODIFY | FAN_ATTRIB | FAN_CLOSE_WRITE | FAN_MOVED_FROM |
| 153 | + | FAN_MOVED_TO | FAN_CREATE | FAN_DELETE | FAN_DELETE_SELF |
| 154 | + | FAN_MOVE_SELF | FAN_OPEN_EXEC | FAN_EVENT_ON_CHILD | FAN_RENAME |
| 155 | + | FAN_ONDIR | FAN_MOVE; |
| 156 | + if (fanotify_mark(fanotifyFd, flags, mask, AT_FDCWD, dir.c_str()) == -1) { |
| 157 | + perror("fanotify_mark"); |
| 158 | + exit(EXIT_FAILURE); |
| 159 | + } |
| 160 | + std::cout << "add watch: " << dir << std::endl; |
| 161 | + |
| 162 | + return true; |
| 163 | + } |
| 164 | + |
| 165 | + void monitor() |
| 166 | + { |
| 167 | + char buf[BUF_SIZE]; |
| 168 | + auto len = read(fanotifyFd, buf, sizeof(buf)); |
| 169 | + if (!isRunning.load()) { |
| 170 | + return; |
| 171 | + } |
| 172 | + if (len <= 0) { |
| 173 | + std::cerr << "read failed" << std::endl; |
| 174 | + return; |
| 175 | + } |
| 176 | + |
| 177 | + fanotify_event_metadata *event = nullptr; |
| 178 | + for (event = reinterpret_cast<struct fanotify_event_metadata *>(buf); |
| 179 | + FAN_EVENT_OK(event, len); |
| 180 | + event = FAN_EVENT_NEXT(event, len)) { |
| 181 | + if (!isRunning.load()) { |
| 182 | + return; // 全局监控，会产生大量事件，需要及时处理退出事件 |
| 183 | + } |
| 184 | + |
| 185 | + const auto *fid = reinterpret_cast<const struct fanotify_event_info_fid *>(event + 1); |
| 186 | + auto *file_handle = (struct file_handle *) fid->handle; |
| 187 | + |
| 188 | + std::string path; |
| 189 | + auto event_fd = open_by_handle_at(mountFd, file_handle, O_RDONLY); |
| 190 | + if (event_fd >= 0) { |
| 191 | + path = getPathFromFd(event_fd); |
| 192 | + close(event_fd); |
| 193 | + if (path.find(dir.string()) == std::string::npos) { |
| 194 | + continue; // 全局监控，不在目标目录下的文件不处理 |
| 195 | + } |
| 196 | + } else { |
| 197 | + if (errno == ESTALE) { |
| 198 | + std::cerr << "File handle is no longer valid. File has been deleted" |
| 199 | + << std::endl; |
| 200 | + continue; |
| 201 | + } |
| 202 | + perror("open_by_handle_at"); |
| 203 | + // exit(EXIT_FAILURE); |
| 204 | + } |
| 205 | + |
| 206 | + std::string filename; |
| 207 | + if (fid->hdr.info_type == FAN_EVENT_INFO_TYPE_DFID_NAME) { |
| 208 | + auto *file_name = file_handle->f_handle + file_handle->handle_bytes; |
| 209 | + filename = std::string(file_name, |
| 210 | + file_name |
| 211 | + + strlen(reinterpret_cast<const char *>(file_name))); |
| 212 | + } else { |
| 213 | + std::cerr << "Received unexpected event info type: " |
| 214 | + << std::to_string(fid->hdr.info_type) << std::endl; |
| 215 | + } |
| 216 | + |
| 217 | + auto fileEvent = maskToString(event->mask) + path; |
| 218 | + if (!filename.empty()) { |
| 219 | + fileEvent += "/" + filename; |
| 220 | + } |
| 221 | + std::cout << fileEvent << std::endl; |
| 222 | + } |
| 223 | + } |
| 224 | + |
| 225 | + void run() |
| 226 | + { |
| 227 | + if (!createFd()) { |
| 228 | + return; |
| 229 | + } |
| 230 | + |
| 231 | + if (!addWatch()) { |
| 232 | + closeFd(); |
| 233 | + return; |
| 234 | + } |
| 235 | + isRunning.store(true); |
| 236 | + while (isRunning.load()) { |
| 237 | + monitor(); |
| 238 | + } |
| 239 | + |
| 240 | + closeFd(); |
| 241 | + } |
| 242 | + |
| 243 | + MonitorDir *q_ptr; |
| 244 | + |
| 245 | + int mountFd = -1; |
| 246 | + int fanotifyFd = -1; |
| 247 | + |
| 248 | + std::filesystem::path dir; |
| 249 | + std::atomic_bool isRunning; |
| 250 | + std::thread monitorThread; |
| 251 | +}; |
| 252 | + |
| 253 | +MonitorDir::MonitorDir(const std::filesystem::path &dir) |
| 254 | + : d_ptr(std::make_unique<MonitorDirPrivate>(this)) |
| 255 | + , m_dir(dir) |
| 256 | + , m_isRunning(false) |
| 257 | +{ |
| 258 | + assert(std::filesystem::is_directory(dir) && std::filesystem::exists(dir)); |
| 259 | + d_ptr->dir = dir; |
| 260 | +} |
| 261 | + |
| 262 | +MonitorDir::~MonitorDir() |
| 263 | +{ |
| 264 | + stop(); |
| 265 | +} |
| 266 | + |
| 267 | +auto MonitorDir::start() -> bool |
| 268 | +{ |
| 269 | + if (m_isRunning) { |
| 270 | + std::cerr << "MonitorDir is already running" << std::endl; |
| 271 | + return false; |
| 272 | + } |
| 273 | + |
| 274 | + m_isRunning.store(true); |
| 275 | + d_ptr->monitorThread = std::thread([this] { |
| 276 | + d_ptr->run(); |
| 277 | + m_isRunning.store(false); |
| 278 | + }); |
| 279 | + |
| 280 | + return true; |
| 281 | +} |
| 282 | + |
| 283 | +void MonitorDir::stop() |
| 284 | +{ |
| 285 | + if (!m_isRunning.load()) { |
| 286 | + std::cerr << "MonitorDir is not running" << std::endl; |
| 287 | + return; |
| 288 | + } |
| 289 | + d_ptr->isRunning.store(false); |
| 290 | + if (d_ptr->monitorThread.joinable()) { |
| 291 | + d_ptr->monitorThread.join(); |
| 292 | + } |
| 293 | +} |
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