serenity/Userland/Services/CrashDaemon/main.cpp

/*
 * Copyright (c) 2020, Itamar S. <itamar8910@gmail.com>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <AK/LexicalPath.h>
#include <Kernel/API/InodeWatcherEvent.h>
#include <LibCore/FileWatcher.h>
#include <LibCore/MappedFile.h>
#include <LibCore/System.h>
#include <LibMain/Main.h>
#include <serenity.h>
#include <spawn.h>
#include <sys/stat.h>
#include <time.h>
#include <unistd.h>

static void wait_until_coredump_is_ready(const String& coredump_path)
{
    while (true) {
        struct stat statbuf;
        if (stat(coredump_path.characters(), &statbuf) < 0) {
            perror("stat");
            VERIFY_NOT_REACHED();
        }
        if (statbuf.st_mode & 0400) // Check if readable
            break;

        usleep(10000); // sleep for 10ms
    }
}

static void launch_crash_reporter(const String& coredump_path, bool unlink_on_exit)
{
    pid_t child;
    const char* argv[4] = { "CrashReporter" };
    if (unlink_on_exit) {
        argv[1] = "--unlink";
        argv[2] = coredump_path.characters();
        argv[3] = nullptr;
    } else {
        argv[1] = coredump_path.characters();
        argv[2] = nullptr;
    }
    if ((errno = posix_spawn(&child, "/bin/CrashReporter", nullptr, nullptr, const_cast<char**>(argv), environ))) {
        perror("posix_spawn");
    } else {
        if (disown(child) < 0)
            perror("disown");
    }
}

ErrorOr<int> serenity_main(Main::Arguments)
{
    TRY(Core::System::pledge("stdio rpath wpath cpath proc exec"));

    Core::BlockingFileWatcher watcher;
    TRY(watcher.add_watch("/tmp/coredump", Core::FileWatcherEvent::Type::ChildCreated));

    while (true) {
        auto event = watcher.wait_for_event();
        VERIFY(event.has_value());
        if (event.value().type != Core::FileWatcherEvent::Type::ChildCreated)
            continue;
        auto& coredump_path = event.value().event_path;
        dbgln("New coredump file: {}", coredump_path);
        wait_until_coredump_is_ready(coredump_path);

        auto file_or_error = Core::MappedFile::map(coredump_path);
        if (file_or_error.is_error()) {
            dbgln("Unable to map coredump {}: {}", coredump_path, file_or_error.error());
            continue;
        }

        launch_crash_reporter(coredump_path, true);
    }
}