/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Copyright (C) 2019, Google Inc. * * main.cpp - cam - The libcamera swiss army knife */ #include #include #include #include #include #include #include #include "camera_session.h" #include "event_loop.h" #include "main.h" #include "options.h" #include "stream_options.h" using namespace libcamera; class CamApp { public: CamApp(); static CamApp *instance(); int init(int argc, char **argv); void cleanup(); int exec(); void quit(); private: void cameraAdded(std::shared_ptr cam); void cameraRemoved(std::shared_ptr cam); void captureDone(); int parseOptions(int argc, char *argv[]); int run(); static std::string cameraName(const Camera *camera); static CamApp *app_; OptionsParser::Options options_; std::unique_ptr cm_; std::atomic_uint loopUsers_; EventLoop loop_; }; CamApp *CamApp::app_ = nullptr; CamApp::CamApp() : loopUsers_(0) { CamApp::app_ = this; } CamApp *CamApp::instance() { return CamApp::app_; } int CamApp::init(int argc, char **argv) { int ret; ret = parseOptions(argc, argv); if (ret < 0) return ret; cm_ = std::make_unique(); ret = cm_->start(); if (ret) { std::cout << "Failed to start camera manager: " << strerror(-ret) << std::endl; return ret; } return 0; } void CamApp::cleanup() { cm_->stop(); } int CamApp::exec() { int ret; ret = run(); cleanup(); return ret; } void CamApp::quit() { loop_.exit(); } int CamApp::parseOptions(int argc, char *argv[]) { StreamKeyValueParser streamKeyValue; OptionsParser parser; parser.addOption(OptCamera, OptionString, "Specify which camera to operate on, by id or by index", "camera", ArgumentRequired, "camera", true); parser.addOption(OptHelp, OptionNone, "Display this help message", "help"); parser.addOption(OptInfo, OptionNone, "Display information about stream(s)", "info"); parser.addOption(OptList, OptionNone, "List all cameras", "list"); parser.addOption(OptListControls, OptionNone, "List cameras controls", "list-controls"); parser.addOption(OptListProperties, OptionNone, "List cameras properties", "list-properties"); parser.addOption(OptMonitor, OptionNone, "Monitor for hotplug and unplug camera events", "monitor"); /* Sub-options of OptCamera: */ parser.addOption(OptCapture, OptionInteger, "Capture until interrupted by user or until frames captured", "capture", ArgumentOptional, "count", false, OptCamera); #ifdef HAVE_KMS parser.addOption(OptDisplay, OptionString, "Display viewfinder through DRM/KMS on specified connector", "display", ArgumentOptional, "connector", false, OptCamera); #endif parser.addOption(OptFile, OptionString, "Write captured frames to disk\n" "If the file name ends with a '/', it sets the directory in which\n" "to write files, using the default file name. Otherwise it sets the\n" "full file path and name. The first '#' character in the file name\n" "is expanded to the camera index, stream name and frame sequence number.\n" "The default file name is 'frame-#.bin'.", "file", ArgumentOptional, "filename", false, OptCamera); parser.addOption(OptStream, &streamKeyValue, "Set configuration of a camera stream", "stream", true, OptCamera); parser.addOption(OptStrictFormats, OptionNone, "Do not allow requested stream format(s) to be adjusted", "strict-formats", ArgumentNone, nullptr, false, OptCamera); parser.addOption(OptMetadata, OptionNone, "Print the metadata for completed requests", "metadata", ArgumentNone, nullptr, false, OptCamera); options_ = parser.parse(argc, argv); if (!options_.valid()) return -EINVAL; if (options_.empty() || options_.isSet(OptHelp)) { parser.usage(); return options_.empty() ? -EINVAL : -EINTR; } return 0; } void CamApp::cameraAdded(std::shared_ptr cam) { std::cout << "Camera Added: " << cam->id() << std::endl; } void CamApp::cameraRemoved(std::shared_ptr cam) { std::cout << "Camera Removed: " << cam->id() << std::endl; } void CamApp::captureDone() { if (--loopUsers_ == 0) EventLoop::instance()->exit(0); } int CamApp::run() { int ret; /* 1. List all cameras. */ if (options_.isSet(OptList)) { std::cout << "Available cameras:" << std::endl; unsigned int index = 1; for (const std::shared_ptr &cam : cm_->cameras()) { std::cout << index << ": " << cameraName(cam.get()) << std::endl; index++; } } /* 2. Create the camera sessions. */ std::vector> sessions; if (options_.isSet(OptCamera)) { unsigned int index = 0; for (const OptionValue &camera : options_[OptCamera].toArray()) { std::unique_ptr session = std::make_unique(cm_.get(), camera.toString(), index, camera.children()); if (!session->isValid()) { std::cout << "Failed to create camera session" << std::endl; return -EINVAL; } std::cout << "Using camera " << session->camera()->id() << " as cam" << index << std::endl; session->captureDone.connect(this, &CamApp::captureDone); sessions.push_back(std::move(session)); index++; } } /* 3. Print camera information. */ if (options_.isSet(OptListControls) || options_.isSet(OptListProperties) || options_.isSet(OptInfo)) { for (const auto &session : sessions) { if (options_.isSet(OptListControls)) session->listControls(); if (options_.isSet(OptListProperties)) session->listProperties(); if (options_.isSet(OptInfo)) session->infoConfiguration(); } } /* 4. Start capture. */ for (const auto &session : sessions) { if (!session->options().isSet(OptCapture)) continue; ret = session->start(); if (ret) { std::cout << "Failed to start camera session" << std::endl; return ret; } loopUsers_++; } /* 5. Enable hotplug monitoring. */ if (options_.isSet(OptMonitor)) { std::cout << "Monitoring new hotplug and unplug events" << std::endl; std::cout << "Press Ctrl-C to interrupt" << std::endl; cm_->cameraAdded.connect(this, &CamApp::cameraAdded); cm_->cameraRemoved.connect(this, &CamApp::cameraRemoved); loopUsers_++; } if (loopUsers_) loop_.exec(); /* 6. Stop capture. */ for (const auto &session : sessions) { if (!session->options().isSet(OptCapture)) continue; session->stop(); } return 0; } std::string CamApp::cameraName(const Camera *camera) { const ControlList &props = camera->properties(); bool addModel = true; std::string name; /* * Construct the name from the camera location, model and ID. The model * is only used if the location isn't present or is set to External. */ if (props.contains(properties::Location)) { switch (props.get(properties::Location)) { case properties::CameraLocationFront: addModel = false; name = "Internal front camera "; break; case properties::CameraLocationBack: addModel = false; name = "Internal back camera "; break; case properties::CameraLocationExternal: name = "External camera "; break; } } if (addModel && props.contains(properties::Model)) { /* * If the camera location is not availble use the camera model * to build the camera name. */ name = "'" + props.get(properties::Model) + "' "; } name += "(" + camera->id() + ")"; return name; } void signalHandler([[maybe_unused]] int signal) { std::cout << "Exiting" << std::endl; CamApp::instance()->quit(); } int main(int argc, char **argv) { CamApp app; int ret; ret = app.init(argc, argv); if (ret) return ret == -EINTR ? 0 : EXIT_FAILURE; struct sigaction sa = {}; sa.sa_handler = &signalHandler; sigaction(SIGINT, &sa, nullptr); if (app.exec()) return EXIT_FAILURE; return 0; } 8'>148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379

/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2019, Google Inc.
 *
 * process.cpp - Process object
 */

#include "process.h"

#include <algorithm>
#include <dirent.h>
#include <fcntl.h>
#include <iostream>
#include <list>
#include <signal.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <vector>

#include <libcamera/event_notifier.h>

#include "log.h"
#include "utils.h"

/**
 * \file process.h
 * \brief Process object
 */

namespace libcamera {

LOG_DEFINE_CATEGORY(Process)

/**
 * \class ProcessManager
 * \brief Manager of processes
 *
 * The ProcessManager singleton keeps track of all created Process instances,
 * and manages the signal handling involved in terminating processes.
 */
class ProcessManager
{
public:
	void registerProcess(Process *proc);

	static ProcessManager *instance();

	int writePipe() const;

	const struct sigaction &oldsa() const;

private:
	void sighandler(EventNotifier *notifier);
	ProcessManager();
	~ProcessManager();

	std::list<Process *> processes_;

	struct sigaction oldsa_;
	EventNotifier *sigEvent_;
	int pipe_[2];
};

namespace {

void sigact(int signal, siginfo_t *info, void *ucontext)
{
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-result"
	/*
	 * We're in a signal handler so we can't log any message, and we need
	 * to continue anyway.
	 */
	char data = 0;
	write(ProcessManager::instance()->writePipe(), &data, sizeof(data));
#pragma GCC diagnostic pop

	const struct sigaction &oldsa = ProcessManager::instance()->oldsa();
	if (oldsa.sa_flags & SA_SIGINFO) {
		oldsa.sa_sigaction(signal, info, ucontext);
	} else {
		if (oldsa.sa_handler != SIG_IGN && oldsa.sa_handler != SIG_DFL)
			oldsa.sa_handler(signal);
	}
}

} /* namespace */

void ProcessManager::sighandler(EventNotifier *notifier)
{
	char data;
	ssize_t ret = read(pipe_[0], &data, sizeof(data));
	if (ret < 0) {
		LOG(Process, Error)
			<< "Failed to read byte from signal handler pipe";
		return;
	}

	for (auto it = processes_.begin(); it != processes_.end(); ) {
		Process *process = *it;

		int wstatus;
		pid_t pid = waitpid(process->pid_, &wstatus, WNOHANG);
		if (process->pid_ != pid) {
			++it;
			continue;
		}

		it = processes_.erase(it);
		process->died(wstatus);
	}
}

/**
 * \brief Register process with process manager
 * \param[in] proc Process to register
 *
 * This method registers the \a proc with the process manager. It
 * shall be called by the parent process after successfully forking, in
 * order to let the parent signal process termination.
 */
void ProcessManager::registerProcess(Process *proc)
{
	processes_.push_back(proc);
}

ProcessManager::ProcessManager()
{
	sigaction(SIGCHLD, NULL, &oldsa_);

	struct sigaction sa;
	memset(&sa, 0, sizeof(sa));
	sa.sa_sigaction = &sigact;
	memcpy(&sa.sa_mask, &oldsa_.sa_mask, sizeof(sa.sa_mask));
	sigaddset(&sa.sa_mask, SIGCHLD);
	sa.sa_flags = oldsa_.sa_flags | SA_SIGINFO;

	sigaction(SIGCHLD, &sa, NULL);

	if (pipe2(pipe_, O_CLOEXEC | O_DIRECT | O_NONBLOCK))
		LOG(Process, Fatal)
			<< "Failed to initialize pipe for signal handling";
	sigEvent_ = new EventNotifier(pipe_[0], EventNotifier::Read);
	sigEvent_->activated.connect(this, &ProcessManager::sighandler);
}

ProcessManager::~ProcessManager()
{
	sigaction(SIGCHLD, &oldsa_, NULL);
	delete sigEvent_;
	close(pipe_[0]);
	close(pipe_[1]);
}

/**
 * \brief Retrieve the Process manager instance
 *
 * The ProcessManager is a singleton and can't be constructed manually. This
 * method shall instead be used to retrieve the single global instance of the
 * manager.
 *
 * \return The Process manager instance
 */
ProcessManager *ProcessManager::instance()
{
	static ProcessManager processManager;
	return &processManager;
}

/**
 * \brief Retrieve the Process manager's write pipe
 *
 * This method is meant only to be used by the static signal handler.
 *
 * \return Pipe for writing
 */
int ProcessManager::writePipe() const
{
	return pipe_[1];
}

/**
 * \brief Retrive the old signal action data
 *
 * This method is meant only to be used by the static signal handler.
 *
 * \return The old signal action data
 */
const struct sigaction &ProcessManager::oldsa() const
{
	return oldsa_;
}


/**
 * \class Process
 * \brief Process object
 *
 * The Process class models a process, and simplifies spawning new processes
 * and monitoring the exiting of a process.
 */

/**
 * \enum Process::ExitStatus
 * \brief Exit status of process
 * \var Process::NotExited
 * The process hasn't exited yet
 * \var Process::NormalExit
 * The process exited normally, either via exit() or returning from main
 * \var Process::SignalExit
 * The process was terminated by a signal (this includes crashing)
 */

Process::Process()
	: pid_(-1), running_(false), exitStatus_(NotExited), exitCode_(0)
{
}

Process::~Process()
{
	kill();
	/* \todo wait for child process to exit */
}

/**
 * \brief Fork and exec a process, and close fds
 * \param[in] path Path to executable
 * \param[in] args Arguments to pass to executable (optional)
 * \param[in] fds Vector of file descriptors to keep open (optional)
 *
 * Fork a process, and exec the executable specified by path. Prior to
 * exec'ing, but after forking, all file descriptors except for those
 * specified in fds will be closed.
 *
 * All indexes of args will be incremented by 1 before being fed to exec(),
 * so args[0] should not need to be equal to path.
 *
 * \return Zero on successful fork, exec, and closing the file descriptors,
 * or a negative error code otherwise
 */
int Process::start(const std::string &path,
		   const std::vector<std::string> &args,
		   const std::vector<int> &fds)
{
	int ret;

	if (running_)
		return 0;

	int childPid = fork();
	if (childPid == -1) {
		ret = -errno;
		LOG(Process, Error) << "Failed to fork: " << strerror(-ret);
		return ret;
	} else if (childPid) {
		pid_ = childPid;
		ProcessManager::instance()->registerProcess(this);

		running_ = true;

		return 0;
	} else {
		if (isolate())
			_exit(EXIT_FAILURE);

		closeAllFdsExcept(fds);

		unsetenv("LIBCAMERA_LOG_FILE");

		const char **argv = new const char *[args.size() + 2];
		unsigned int len = args.size();
		argv[0] = path.c_str();
		for (unsigned int i = 0; i < len; i++)
			argv[i+1] = args[i].c_str();
		argv[len+1] = nullptr;

		execv(path.c_str(), (char **)argv);

		exit(EXIT_FAILURE);
	}
}

void Process::closeAllFdsExcept(const std::vector<int> &fds)
{
	std::vector<int> v(fds);
	sort(v.begin(), v.end());

	DIR *dir = opendir("/proc/self/fd");
	if (!dir)
		return;

	int dfd = dirfd(dir);

	struct dirent *ent;
	while ((ent = readdir(dir)) != nullptr) {
		char *endp;
		int fd = strtoul(ent->d_name, &endp, 10);
		if (*endp)
			continue;

		if (fd >= 0 && fd != dfd &&
		    !std::binary_search(v.begin(), v.end(), fd))
			close(fd);
	}

	closedir(dir);
}

int Process::isolate()
{
	int ret = unshare(CLONE_NEWUSER | CLONE_NEWNET);
	if (ret) {
		ret = -errno;
		LOG(Process, Error) << "Failed to unshare execution context: "
				    << strerror(-ret);
		return ret;
	}

	return 0;
}

/**