Services: Move to Userland/Services/

Author: https://github.com/awesomekling
Commit: c7ac7e6eaf

Userland/Services/SystemServer/main.cpp

@@ -0,0 +1,242 @@
+/*
+ * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "Service.h"
+#include <AK/Assertions.h>
+#include <AK/ByteBuffer.h>
+#include <LibCore/ConfigFile.h>
+#include <LibCore/Event.h>
+#include <LibCore/EventLoop.h>
+#include <LibCore/File.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+String g_boot_mode = "graphical";
+
+static void sigchld_handler(int)
+{
+    for (;;) {
+        int status = 0;
+        pid_t pid = waitpid(-1, &status, WNOHANG);
+        if (pid < 0) {
+            perror("waitpid");
+            break;
+        }
+        if (pid == 0)
+            break;
+
+#ifdef SYSTEMSERVER_DEBUG
+        dbg() << "Reaped child with pid " << pid << ", exit status " << status;
+#endif
+
+        Service* service = Service::find_by_pid(pid);
+        if (service == nullptr) {
+            // This can happen for multi-instance services.
+            continue;
+        }
+
+        service->did_exit(status);
+    }
+}
+
+static void parse_boot_mode()
+{
+    auto f = Core::File::construct("/proc/cmdline");
+    if (!f->open(Core::IODevice::ReadOnly)) {
+        dbg() << "Failed to read command line: " << f->error_string();
+        return;
+    }
+    const String cmdline = String::copy(f->read_all(), Chomp);
+    dbg() << "Read command line: " << cmdline;
+
+    for (auto& part : cmdline.split_view(' ')) {
+        auto pair = part.split_view('=', 2);
+        if (pair.size() == 2 && pair[0] == "boot_mode")
+            g_boot_mode = pair[1];
+    }
+    dbg() << "Booting in " << g_boot_mode << " mode";
+}
+
+static void prepare_devfs()
+{
+    // FIXME: Find a better way to all of this stuff, without hardcoding all of this!
+
+    int rc = mount(-1, "/dev", "dev", 0);
+    if (rc != 0) {
+        ASSERT_NOT_REACHED();
+    }
+
+    rc = mkdir("/dev/pts", 0755);
+    if (rc != 0) {
+        ASSERT_NOT_REACHED();
+    }
+
+    rc = mount(-1, "/dev/pts", "devpts", 0);
+    if (rc != 0) {
+        ASSERT_NOT_REACHED();
+    }
+
+    rc = symlink("/dev/random", "/dev/urandom");
+    if (rc < 0) {
+        ASSERT_NOT_REACHED();
+    }
+
+    // FIXME: Find a better way to chown without hardcoding the gid!
+    // This will fail with ENOENT in text mode.
+    rc = chown("/dev/fb0", 0, 3);
+    if (rc < 0 && errno != ENOENT) {
+        ASSERT_NOT_REACHED();
+    }
+
+    // FIXME: Find a better way to chown without hardcoding the gid!
+    rc = chown("/dev/keyboard", 0, 3);
+    if (rc < 0) {
+        ASSERT_NOT_REACHED();
+    }
+
+    // FIXME: Find a better way to chown without hardcoding the gid!
+    rc = chown("/dev/mouse", 0, 3);
+    if (rc < 0) {
+        ASSERT_NOT_REACHED();
+    }
+
+    for (size_t index = 0; index < 4; index++) {
+        // FIXME: Find a better way to chown without hardcoding the gid!
+        rc = chown(String::formatted("/dev/tty{}", index).characters(), 0, 2);
+        if (rc < 0) {
+            ASSERT_NOT_REACHED();
+        }
+    }
+
+    for (size_t index = 0; index < 4; index++) {
+        // FIXME: Find a better way to chown without hardcoding the gid!
+        rc = chown(String::formatted("/dev/ttyS{}", index).characters(), 0, 2);
+        if (rc < 0) {
+            ASSERT_NOT_REACHED();
+        }
+    }
+
+    // FIXME: Find a better way to chown without hardcoding the gid!
+    rc = chown("/dev/audio", 0, 4);
+    if (rc < 0) {
+        ASSERT_NOT_REACHED();
+    }
+
+    rc = symlink("/proc/self/fd/0", "/dev/stdin");
+    if (rc < 0) {
+        ASSERT_NOT_REACHED();
+    }
+    rc = symlink("/proc/self/fd/1", "/dev/stdout");
+    if (rc < 0) {
+        ASSERT_NOT_REACHED();
+    }
+    rc = symlink("/proc/self/fd/2", "/dev/stderr");
+    if (rc < 0) {
+        ASSERT_NOT_REACHED();
+    }
+}
+
+static void mount_all_filesystems()
+{
+    dbgln("Spawning mount -a to mount all filesystems.");
+    pid_t pid = fork();
+
+    if (pid < 0) {
+        perror("fork");
+        ASSERT_NOT_REACHED();
+    } else if (pid == 0) {
+        execl("/bin/mount", "mount", "-a", nullptr);
+        perror("exec");
+        ASSERT_NOT_REACHED();
+    } else {
+        wait(nullptr);
+    }
+}
+
+static void create_tmp_rpc_directory()
+{
+    dbgln("Creating /tmp/rpc directory");
+    auto old_umask = umask(0);
+    auto rc = mkdir("/tmp/rpc", 01777);
+    if (rc < 0) {
+        perror("mkdir(/tmp/rpc)");
+        ASSERT_NOT_REACHED();
+    }
+    umask(old_umask);
+}
+
+static void create_tmp_coredump_directory()
+{
+    dbgln("Creating /tmp/coredump directory");
+    auto old_umask = umask(0);
+    auto rc = mkdir("/tmp/coredump", 0755);
+    if (rc < 0) {
+        perror("mkdir(/tmp/coredump)");
+        ASSERT_NOT_REACHED();
+    }
+    umask(old_umask);
+}
+
+int main(int, char**)
+{
+    prepare_devfs();
+
+    if (pledge("stdio proc exec tty accept unix rpath wpath cpath chown fattr id sigaction", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+
+    mount_all_filesystems();
+    create_tmp_rpc_directory();
+    create_tmp_coredump_directory();
+    parse_boot_mode();
+
+    Core::EventLoop event_loop;
+
+    event_loop.register_signal(SIGCHLD, sigchld_handler);
+
+    // Read our config and instantiate services.
+    // This takes care of setting up sockets.
+    NonnullRefPtrVector<Service> services;
+    auto config = Core::ConfigFile::get_for_system("SystemServer");
+    for (auto name : config->groups()) {
+        auto service = Service::construct(*config, name);
+        if (service->is_enabled())
+            services.append(service);
+    }
+
+    // After we've set them all up, activate them!
+    dbg() << "Activating " << services.size() << " services...";
+    for (auto& service : services)
+        service.activate();
+
+    return event_loop.exec();
+}