Merge pull request #138 from wkz/boot-refactor

Bootstrap refactor

configure.ac

@@ -101,6 +101,7 @@ AC_ARG_ENABLE(contrib,
 enable_all_plugins=auto
 AC_PLUGIN([alsa-utils],    [no],  [Save and restore ALSA sound settings using alsactl])
 AC_PLUGIN([dbus],          [no],  [Setup and start system message bus, D-Bus])
+AC_PLUGIN([hotplug],       [yes], [Setup and start udev or mdev hotplug daemon])
 AC_PLUGIN([inetd-echo],    [no],  [Inetd plugin: echo server, RFC862])
 AC_PLUGIN([inetd-chargen], [no],  [Inetd plugin: character generator, RFC864])
 AC_PLUGIN([inetd-daytime], [no],  [Inetd plugin: daytime server, RFC867])

contrib/fstab.bb

@@ -0,0 +1,15 @@
+# This is a basic /etc/fstab that mounts up all of the virtual filesystems
+# that older versions of Finit used to mount internally. It can serve as a
+# starting point for systems running Busybox's mount implementation. Make
+# sure that CONFIG_FEATURE_MOUNT_HELPERS enabled; as this is required
+# create the /dev/{pts,shm} directories.
+
+devtmpfs	/dev		devtmpfs	defaults		0	0
+mkdir#-p	/dev/pts	helper		none			0	0
+devpts		/dev/pts	devpts		mode=620,ptmxmode=0666	0	0
+mkdir#-p	/dev/shm	helper		none			0	0
+tmpfs		/dev/shm	tmpfs		mode=0777		0	0
+proc		/proc		proc		defaults		0	0
+tmpfs		/tmp		tmpfs		mode=1777,nosuid,nodev	0	0
+tmpfs		/run		tmpfs		mode=0755,nosuid,nodev	0	0
+sysfs		/sys		sysfs		defaults		0	0

doc/plugins.md

@@ -42,6 +42,9 @@ For your convenience a set of *optional* plugins are available:
 
 * *discard.so*: RFC 863 plugin.  Start as inetd service, like time below.
 
+* *hotplug.so*: Setup and start either udev or mdev hotplug daemon, if
+  available.
+
 * *rtc.so*: Restore and save system clock from/to RTC on boot/halt.
 
 * *initctl.so*: Extends finit with a traditional `initctl` functionality.

plugins/Makefile.am

@@ -17,6 +17,10 @@ if BUILD_DBUS_PLUGIN
 libplug_la_SOURCES += dbus.c
 endif
 
+if BUILD_HOTPLUG_PLUGIN
+libplug_la_SOURCES += hotplug.c
+endif
+
 if INETD
 if BUILD_INETD_ECHO_PLUGIN
 libplug_la_SOURCES += echo.c
@@ -62,6 +66,10 @@ if BUILD_DBUS_PLUGIN
 pkglib_LTLIBRARIES += dbus.la
 endif
 
+if BUILD_HOTPLUG_PLUGIN
+pkglib_LTLIBRARIES += hotplug.la
+endif
+
 if INETD
 if BUILD_INETD_ECHO_PLUGIN
 pkglib_LTLIBRARIES += echo.la

plugins/hotplug.c

@@ -0,0 +1,110 @@
+/* Heuristically find and initialize a suitable hotplug daemon
+ *
+ * Copyright (c) 2012-2020 Joachim Wiberg <troglobit@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include <stdio.h>
+
+#include "config.h"
+#include "conf.h"
+#include "finit.h"
+#include "helpers.h"
+#include "plugin.h"
+#include "service.h"
+
+static void setup(void *arg)
+{
+	char cmd[256];
+	char *path;
+
+	/*
+	 * Populate /dev and prepare for runtime events from kernel.
+	 * Prefer udev if mdev is also available on the system.
+	 */
+	path = which("udevd");
+	if (!path)
+		path = which("/lib/systemd/systemd-udevd");
+	if (path) {
+		/* Register udevd as a monitored service */
+		snprintf(cmd, sizeof(cmd), "[S12345789] pid:udevd %s "
+			 "-- Device event managing daemon", path);
+		if (service_register(SVC_TYPE_SERVICE, cmd, global_rlimit, NULL)) {
+			_pe("Failed registering %s", path);
+		} else {
+			snprintf(cmd, sizeof(cmd), ":1 [S] <svc%s> "
+				 "udevadm trigger -c add -t devices "
+				 "-- Requesting device events", path);
+			service_register(SVC_TYPE_RUN, cmd, global_rlimit, NULL);
+
+			snprintf(cmd, sizeof(cmd), ":2 [S] <svc%s> "
+				 "udevadm trigger -c add -t subsystems "
+				 "-- Requesting subsystem events", path);
+			service_register(SVC_TYPE_RUN, cmd, global_rlimit, NULL);
+		}
+
+		free(path);
+
+		/* Debian has this little script to copy generated
+		 * rules while the system was read-only. TODO: When
+		 * this functionality was hardcoded in finit.c, this
+		 * call was made in crank_worker(). Now that
+		 * filesystems are mounted earlier we should be able
+		 * to make this call directly after the triggers have
+		 * run, but this has not been tested AT ALL. */
+		if (fexist("/lib/udev/udev-finish"))
+			run_interactive("/lib/udev/udev-finish", "Finalizing udev");
+	} else {
+		path = which("mdev");
+		if (path) {
+			/* Embedded Linux systems usually have BusyBox mdev */
+			if (log_is_debug())
+				touch("/dev/mdev.log");
+
+			snprintf(cmd, sizeof(cmd), "%s -s", path);
+			free(path);
+
+			run_interactive(cmd, "Populating device tree");
+		}
+	}
+}
+
+static plugin_t plugin = {
+	.name = __FILE__,
+	.hook[HOOK_BASEFS_UP] = {
+		.cb  = setup
+	},
+};
+
+PLUGIN_INIT(plugin_init)
+{
+	plugin_register(&plugin);
+}
+
+PLUGIN_EXIT(plugin_exit)
+{
+	plugin_unregister(&plugin);
+}
+
+/**
+ * Local Variables:
+ *  indent-tabs-mode: t
+ *  c-file-style: "linux"
+ * End:
+ */

src/conf.c

@@ -59,6 +59,22 @@ static TAILQ_HEAD(head, conf_change) conf_change_list = TAILQ_HEAD_INITIALIZER(c
 static int parse_conf(char *file);
 static void drop_changes(void);
 
+static void hide_args(int argc, char *argv[])
+{
+	/*
+	 * Hide command line arguments from ps (in particular for
+	 * forked children that don't execv()).  This is an ugly
+	 * hack that only works on Linux.
+	 * https://web.archive.org/web/20110227041321/http://netsplit.com/2007/01/10/hiding-arguments-from-ps/
+	 */
+	if (argc > 1) {
+		char *arg_end;
+
+		arg_end = argv[argc-1] + strlen (argv[argc-1]);
+		*arg_end = ' ';
+	}
+}
+
 static void parse_arg(char *arg, int *dbg)
 {
 	/* Catches finit_debug (deprecated), --debug, and debug */
@@ -84,6 +100,8 @@ void conf_parse_cmdline(int argc, char *argv[])
 	for (int i = 1; i < argc; i++)
 		parse_arg(argv[i], &dbg);
 
+	hide_args(argc, argv);
+
 	fp = fopen("/proc/cmdline", "r");
 	if (!fp)
 		goto done;

src/finit.c

@@ -66,18 +66,13 @@ char *runparts  = NULL;
 uev_ctx_t *ctx  = NULL;		/* Main loop context */
 svc_t *wdog     = NULL;		/* No watchdog by default */
 
-static int udev = 0;		/* Runtime detection of udev */
-
 
 /*
  * Show user configured banner before service bootstrap progress
  */
 static void banner(void)
 {
-	if (plugin_exists(HOOK_BANNER)) {
-		plugin_run_hooks(HOOK_BANNER);
-		return;
-	}
+	plugin_run_hooks(HOOK_BANNER);
 
 	if (log_is_silent())
 		return;
@@ -91,7 +86,6 @@ static void banner(void)
 static int fsck(int pass)
 {
 	struct fstab *fs;
-//	int save;
 	int rc = 0;
 
 	if (!setfsent()) {
@@ -99,9 +93,6 @@ static int fsck(int pass)
 		return 1;
 	}
 
-//	if ((save = log_is_debug()))
-//		log_debug();
-
 	while ((fs = getfsent())) {
 		char cmd[80];
 		struct stat st;
@@ -126,13 +117,85 @@ static int fsck(int pass)
 		rc += run_interactive(cmd, "Checking filesystem %.13s", fs->fs_spec);
 	}
 
-//	if (save)
-//		log_debug();
 	endfsent();
 
 	return rc;
 }
 
+static int fsck_all(void)
+{
+	int pass, rc = 0;
+
+	for (pass = 1; pass < 10; pass++) {
+		rc = fsck(pass);
+		if (rc)
+			break;
+	}
+
+	return rc;
+}
+
+#ifndef SYSROOT
+static void fs_remount_root(int fsckerr)
+{
+	struct fstab *fs;
+
+	if (!setfsent())
+		return;
+
+	while ((fs = getfsent())) {
+		if (!strcmp(fs->fs_file, "/"))
+			break;
+	}
+
+	/* If / is not listed in fstab, or listed as 'ro', leave it
+	 * alone. */
+	if (!fs || !strcmp(fs->fs_type, "ro"))
+		goto out;
+
+	if (fsckerr)
+		print(1, "Cannot remount / as read-write, fsck failed before");
+	else
+		run_interactive("mount -n -o remount,rw /",
+				"Remounting / as read-write");
+
+out:
+	endfsent();
+}
+#else
+static void fs_remount_root(int fsckerr)
+{
+	/*
+	 * XXX: Untested, in the initramfs age we should
+	 *      probably use switch_root instead.
+	 */
+	rc = mount(SYSROOT, "/", NULL, MS_MOVE, NULL);
+}
+#endif	/* SYSROOT */
+
+static void fs_init(void)
+{
+	int fsckerr;
+
+	if (!rescue) {
+		fsckerr = fsck_all();
+		fs_remount_root(fsckerr);
+	}
+
+
+	_d("Root FS up, calling hooks ...");
+	plugin_run_hooks(HOOK_ROOTFS_UP);
+
+	if (run_interactive("mount -na", "Mounting filesystems"))
+		plugin_run_hooks(HOOK_MOUNT_ERROR);
+
+	_d("Calling extra mount hook, after mount -a ...");
+	plugin_run_hooks(HOOK_MOUNT_POST);
+
+	run("swapon -ea");
+	umask(0022);
+}
+
 /*
  * If everything goes south we can use this to give the operator an
  * emergency shell to debug the problem -- Finit should not crash!
@@ -239,10 +302,6 @@ static void crank_worker(void *unused)
 	 */
 	sm_init(&sm);
 	sm_step(&sm);
-
-	/* Debian has this little script to copy generated rules while the system was read-only */
-	if (udev && fexist("/lib/udev/udev-finish"))
-		run_interactive("/lib/udev/udev-finish", "Finalizing udev");
 }
 
 /*
@@ -281,9 +340,6 @@ int main(int argc, char *argv[])
 		.delay = 1000
 	};
 	uev_ctx_t loop;
-	char cmd[256];
-	char *path;
-	int rc = 0;
 
 	/*
 	 * finit/init/telinit client tool uses /dev/initctl pipe
@@ -298,19 +354,6 @@ int main(int argc, char *argv[])
 	 */
 	conf_parse_cmdline(argc, argv);
 
-	/*
-	 * Hide command line arguments from ps (in particular for
-	 * forked children that don't execv()).  This is an ugly
-	 * hack that only works on Linux.
-	 * https://web.archive.org/web/20110227041321/http://netsplit.com/2007/01/10/hiding-arguments-from-ps/
-	 */
-	if (argc > 1) {
-		char *arg_end;
-
-		arg_end = argv[argc-1] + strlen (argv[argc-1]);
-		*arg_end = ' ';
-	}
-
 	/*
 	 * Initalize event context.
 	 */
@@ -335,23 +378,8 @@ int main(int argc, char *argv[])
 	 */
 	emergency_shell();
 
-	/*
-	 * Initial setup of signals, ignore all until we're up.
-	 */
-	sig_init();
-
-	/*
-	 * Mount base file system
-	 */
-	if (!fismnt("/proc") && mount("none", "/proc", "proc", 0, NULL))
-		_pe("Failed mounting /proc");
-	if (fisdir("/proc/bus/usb"))
-		mount("none", "/proc/bus/usb", "usbfs", 0, NULL);
-
-	/*
-	 * Load plugins early, finit.conf may contain references to
-	 * features implemented by plugins.
-	 */
+	/* Load plugins early, the first hook is in banner(), so we
+	 * need plugins loaded before calling it. */
 	plugin_init(&loop);
 
 	/*
@@ -360,178 +388,37 @@ int main(int argc, char *argv[])
 	banner();
 
 	/*
-	 * Check file systems listed with pass > 0 in /etc/fstab
+	 * Initial setup of signals, ignore all until we're up.
 	 */
-	rc = 0;
-	for (int pass = 1; pass < 10 && !rescue; pass++) {
-		rc = fsck(pass);
-		if (rc)
-			break;
-	}
-
-	/*
-	 * Mount filesystems
-	 */
-	if (!rescue) {
-#ifndef SYSROOT
-		/*
-		 * Remount / read-write if it exists in fstab is not 'ro'.
-		 * This is what the Debian sysv initscripts does.
-		 */
-		if (setfsent()) {
-			struct fstab *fs;
-
-			while ((fs = getfsent())) {
-				if (strcmp(fs->fs_file, "/"))
-					continue;
-
-				if (strcmp(fs->fs_type, "ro")) {
-					if (rc)
-						print(1, "Cannot remount / as read-write, fsck failed before");
-					else
-						rc = run_interactive("mount -n -o remount,rw /", "Remounting / as read-write");
-				}
-				break;
-			}
-
-			endfsent();
-		}
-#else
-		/*
-		 * XXX: Untested, in the initramfs age we should
-		 *      probably use switch_root instead.
-		 */
-		rc = mount(SYSROOT, "/", NULL, MS_MOVE, NULL);
-#endif
-	}
-
-	/* Create /sys if missing, some systems don't include it in their rootfs skeleton */
-	if (!rc && !fisdir("/sys"))
-		mkdir("/sys", 0755);
-
-	/* Only mount /sys if it's not already mounted */
-	if (!fismnt("/sys") && mount("none", "/sys", "sysfs", 0, NULL)) {
-		print(1, "Cannot mount /sys, your system may behave unusually");
-		_pe("Failed mounting /sys");
-	}
+	sig_init();
 
 	/*
 	 * Initialize default control groups, if available
 	 */
 	cgroup_init();
 
+
+	/* Check and mount filesystems. */
+	fs_init();
+
 	/*
-	 * Initialize .conf system and load static /etc/finit.conf
-	 * Also initializes global_rlimit[] for udevd, below.
+	 * Initialize .conf system and load static /etc/finit.conf.
 	 */
 	conf_init();
 
-	/*
-	 * Some non-embedded systems without an initramfs may not have /dev mounted yet
-	 * If they do, check if system has udevadm and perform cleanup from initramfs
-	 */
-	if (!fismnt("/dev"))
-		mount("udev", "/dev", "devtmpfs", MS_RELATIME, "size=10%,nr_inodes=61156,mode=755");
-	else if (whichp("udevadm"))
-		run_interactive("udevadm info --cleanup-db", "Cleaning up udev db");
-
-	/* Modern systems use /dev/pts */
-	makedir("/dev/pts", 0755);
-	mount("devpts", "/dev/pts", "devpts", 0, "gid=5,mode=620,ptmxmode=0666");
-
-	/*
-	 * Some systems rely on us to both create /dev/shm and, to mount
-	 * a tmpfs there.  Any system with dbus needs shared memory, so
-	 * mount it, unless its already mounted, but not if listed in
-	 * the /etc/fstab file already.
-	 */
-	makedir("/dev/shm", 0755);
-	if (!fismnt("/dev/shm") && !ismnt("/etc/fstab", "/dev/shm", NULL))
-		mount("shm", "/dev/shm", "tmpfs", 0, "mode=0777");
-
-	/*
-	 * New tmpfs based /run for volatile runtime data
-	 * For details, see http://lwn.net/Articles/436012/
-	 */
-	if (fisdir("/run") && !fismnt("/run"))
-		mount("tmpfs", "/run", "tmpfs", MS_NODEV | MS_NOSUID | MS_NOEXEC, "mode=0755,size=10%");
-	umask(022);
-
 	/* Bootstrap conditions, needed for hooks */
 	cond_init();
 
-	/*
-	 * Populate /dev and prepare for runtime events from kernel.
-	 * Prefer udev if mdev is also available on the system.
-	 */
-	path = which("udevd");
-	if (!path)
-		path = which("/lib/systemd/systemd-udevd");
-	if (path) {
-		/* Desktop and server distros usually have a variant of udev */
-		udev = 1;
-
-		/* Register udevd as a monitored service */
-		snprintf(cmd, sizeof(cmd), "[S12345789] pid:udevd %s -- Device event managing daemon", path);
-		if (service_register(SVC_TYPE_SERVICE, cmd, global_rlimit, NULL)) {
-			_pe("Failed registering %s", path);
-			udev = 0;
-		} else {
-			snprintf(cmd, sizeof(cmd), ":1 [S] <svc%s> "
-				 "udevadm trigger -c add -t devices "
-				 "-- Requesting device events", path);
-			service_register(SVC_TYPE_RUN, cmd, global_rlimit, NULL);
-
-			snprintf(cmd, sizeof(cmd), ":2 [S] <svc%s> "
-				 "udevadm trigger -c add -t subsystems "
-				 "-- Requesting subsystem events", path);
-			service_register(SVC_TYPE_RUN, cmd, global_rlimit, NULL);
-		}
-		free(path);
-	} else {
-		path = which("mdev");
-		if (path) {
-			/* Embedded Linux systems usually have BusyBox mdev */
-			if (log_is_debug())
-				touch("/dev/mdev.log");
-
-			snprintf(cmd, sizeof(cmd), "%s -s", path);
-			free(path);
-
-			run_interactive(cmd, "Populating device tree");
-		}
-	}
-
-	/*
-	 * Start bundled watchdogd as soon as possible, if enabled
-	 */
-	if (which(FINIT_LIBPATH_ "/watchdogd")) {
-		service_register(SVC_TYPE_SERVICE, FINIT_LIBPATH_ "/watchdogd -- Finit watchdog daemon", global_rlimit, NULL);
-		wdog = svc_find(FINIT_LIBPATH_ "/watchdogd", NULL);
-	}
-
-	if (!rescue) {
-		_d("Root FS up, calling hooks ...");
-		plugin_run_hooks(HOOK_ROOTFS_UP);
-
-		umask(0);
-		if (run_interactive("mount -na", "Mounting filesystems"))
-			plugin_run_hooks(HOOK_MOUNT_ERROR);
-
-		_d("Calling extra mount hook, after mount -a ...");
-		plugin_run_hooks(HOOK_MOUNT_POST);
-
-		run("swapon -ea");
-		umask(0022);
-	}
+	/* Emit conditions for early hooks that ran before the
+	 * condition system was initialized in case anyone . */
+	cond_set_oneshot(plugin_hook_str(HOOK_BANNER));
+	cond_set_oneshot(plugin_hook_str(HOOK_ROOTFS_UP));
 
 	/* Base FS up, enable standard SysV init signals */
 	sig_setup(&loop);
 
-	if (!rescue) {
-		_d("Base FS up, calling hooks ...");
-		plugin_run_hooks(HOOK_BASEFS_UP);
-	}
+	_d("Base FS up, calling hooks ...");
+	plugin_run_hooks(HOOK_BASEFS_UP);
 
 	/*
 	 * Set up inotify watcher for /etc/finit.d and read all .conf

src/plugin.c

@@ -201,7 +201,12 @@ void plugin_run_hook(hook_point_t no, void *arg)
 		}
 	}
 
-	cond_set_oneshot(hook_cond[no]);
+	/* Conditions are stored in /run, so don't try to signal
+	 * conditions for any hooks before filesystems have been
+	 * mounted. */
+	if (no >= HOOK_MOUNT_ERROR)
+		cond_set_oneshot(hook_cond[no]);
+
 	service_step_all(SVC_TYPE_RUNTASK);
 }