openrc/src/librc.c

/*
   librc 
   core RC functions
   Copyright 2007 Gentoo Foundation
   Released under the GPLv2
   */

#include "librc.h"

/* usecs to wait while we poll the fifo */
#define WAIT_INTERVAL	20000000

/* max nsecs to wait until a service comes up */
#define WAIT_MAX	60000000000

#define SOFTLEVEL	RC_SVCDIR "/softlevel"

#ifndef S_IXUGO
# define S_IXUGO (S_IXUSR | S_IXGRP | S_IXOTH)
#endif

/* File stream used for plugins to write environ vars to */
FILE *rc_environ_fd = NULL;

typedef struct rc_service_state_name {
	rc_service_state_t state;
	const char *name;
} rc_service_state_name_t;

/* We MUST list the states below 0x10 first
 * The rest can be in any order */
static const rc_service_state_name_t rc_service_state_names[] = {
	{ RC_SERVICE_STARTED,     "started" },
	{ RC_SERVICE_STOPPED,     "stopped" },
	{ RC_SERVICE_STARTING,    "starting" },
	{ RC_SERVICE_STOPPING,    "stopping" },
	{ RC_SERVICE_INACTIVE,    "inactive" },
	{ RC_SERVICE_WASINACTIVE, "wasinactive" },
	{ RC_SERVICE_COLDPLUGGED, "coldplugged" },
	{ RC_SERVICE_FAILED,      "failed" },
	{ RC_SERVICE_SCHEDULED,   "scheduled"},
	{ 0, NULL}
};


#define LS_INITD	0x01
#define LS_DIR   0x02
static char **ls_dir (const char *dir, int options)
{
	DIR *dp;
	struct dirent *d;
	char **list = NULL;

	if ((dp = opendir (dir)) == NULL) 
		return (NULL);

	errno = 0;
	while (((d = readdir (dp)) != NULL) && errno == 0) {
		if (d->d_name[0] != '.') {
			if (options & LS_INITD) {
				int l = strlen (d->d_name);
				char *init = rc_strcatpaths (RC_INITDIR, d->d_name,
											 (char *) NULL);
				bool ok = rc_exists (init);
				free (init);
				if (! ok)
					continue;

				/* .sh files are not init scripts */
				if (l > 2 && d->d_name[l - 3] == '.' &&
					d->d_name[l - 2] == 's' &&
					d->d_name[l - 1] == 'h')
					continue;
			}
			if (options & LS_DIR) {
				struct stat buf;

				if (stat (d->d_name, &buf) == 0 && ! S_ISDIR (buf.st_mode))
					continue;
			}
			rc_strlist_addsort (&list, d->d_name);
		}
	}
	closedir (dp);

	return (list);
}

static bool rm_dir (const char *pathname, bool top)
{
	DIR *dp;
	struct dirent *d;

	if ((dp = opendir (pathname)) == NULL)
		return (false);

	errno = 0;
	while (((d = readdir (dp)) != NULL) && errno == 0) {
		if (strcmp (d->d_name, ".") != 0 && strcmp (d->d_name, "..") != 0) {
			char *tmp = rc_strcatpaths (pathname, d->d_name, (char *) NULL);
			if (d->d_type == DT_DIR) {
				if (! rm_dir (tmp, true))
				{
					free (tmp);
					closedir (dp);
					return (false);
				}
			} else {
				if (unlink (tmp)) {
					free (tmp);
					closedir (dp);
					return (false);
				}
			}
			free (tmp);
		}
	}
	closedir (dp);

	if (top && rmdir (pathname) != 0)
		return (false);

	return (true);
}

static const char *rc_parse_service_state (rc_service_state_t state)
{
	int i;

	for (i = 0; rc_service_state_names[i].name; i++) {
		if (rc_service_state_names[i].state == state)
			return (rc_service_state_names[i].name);
	}

	return (NULL);
}

bool rc_runlevel_starting (void)
{
	return (rc_exists (RC_STARTING));
}
librc_hidden_def(rc_runlevel_starting)

bool rc_runlevel_stopping (void)
{
	return (rc_exists (RC_STOPPING));
}
librc_hidden_def(rc_runlevel_stopping)

char **rc_runlevel_list (void)
{
	return (ls_dir (RC_RUNLEVELDIR, LS_DIR));
}
librc_hidden_def(rc_runlevel_list)

char *rc_runlevel_get (void)
{
	FILE *fp;
	char buffer[RC_LINEBUFFER];
	char *runlevel = NULL;

	if ((fp = fopen (SOFTLEVEL, "r"))) {
		if (fgets (buffer, PATH_MAX, fp)) {
			int i = strlen (buffer) - 1;
			if (buffer[i] == '\n')
				buffer[i] = 0;
			runlevel = rc_xstrdup (buffer);
		}
		fclose (fp);
	}

	if (! runlevel)
		runlevel = rc_xstrdup (RC_LEVEL_SYSINIT);

	return (runlevel);
}
librc_hidden_def(rc_runlevel_get)

bool rc_runlevel_set (const char *runlevel)
{
	FILE *fp = fopen (SOFTLEVEL, "w");

	if (! fp)
		return (false);
	fprintf (fp, "%s", runlevel);
	fclose (fp);
	return (true);
}
librc_hidden_def(rc_runlevel_set)

bool rc_runlevel_exists (const char *runlevel)
{
	char *path;
	struct stat buf;
	bool retval = false;

	if (! runlevel)
		return (false);

	path = rc_strcatpaths (RC_RUNLEVELDIR, runlevel, (char *) NULL);
	if (stat (path, &buf) == 0 && S_ISDIR (buf.st_mode))
		retval = true;
	free (path);
	return (retval);
}
librc_hidden_def(rc_runlevel_exists)

/* Resolve a service name to it's full path */
char *rc_service_resolve (const char *service)
{
	char buffer[PATH_MAX];
	char *file;
	int r = 0;
	struct stat buf;

	if (! service)
		return (NULL);

	if (service[0] == '/')
		return (rc_xstrdup (service));

	file = rc_strcatpaths (RC_SVCDIR, "started", service, (char *) NULL);
	if (lstat (file, &buf) || ! S_ISLNK (buf.st_mode)) {
		free (file);
		file = rc_strcatpaths (RC_SVCDIR, "inactive", service, (char *) NULL);
		if (lstat (file, &buf) || ! S_ISLNK (buf.st_mode)) {
			free (file);
			file = NULL;
		}
	}

	memset (buffer, 0, sizeof (buffer));
	if (file) {
		r = readlink (file, buffer, sizeof (buffer));
		free (file);
		if (r > 0)
			return (rc_xstrdup (buffer));
	}

	snprintf (buffer, sizeof (buffer), RC_INITDIR "/%s", service);
	return (rc_xstrdup (buffer));
}
librc_hidden_def(rc_service_resolve)

bool rc_service_exists (const char *service)
{
	char *file;
	bool retval = false;
	int len;
	struct stat buf;

	if (! service)
		return (false);

	len = strlen (service);

	/* .sh files are not init scripts */
	if (len > 2 && service[len - 3] == '.' &&
		service[len - 2] == 's' &&
		service[len - 1] == 'h')
		return (false);

	file = rc_service_resolve (service);
	if (stat (file, &buf) == 0 && buf.st_mode & S_IXUGO)
		retval = true;
	free (file);
	return (retval);
}
librc_hidden_def(rc_service_exists)

char **rc_service_options (const char *service)
{
	char *svc;
	char cmd[PATH_MAX];
	char buffer[RC_LINEBUFFER];
	char **opts = NULL;
	char *token;
	char *p = buffer;
	FILE *fp;

	if (! (svc = rc_service_resolve (service)))
		return (NULL);

	snprintf (cmd, sizeof (cmd), ". '%s'; echo \"${opts}\"",  svc);
	free (svc);
	if (! (fp = popen (cmd, "r")))
		return (NULL);

	if (fgets (buffer, RC_LINEBUFFER, fp)) {
		if (buffer[strlen (buffer) - 1] == '\n')
			buffer[strlen (buffer) - 1] = '\0';
		while ((token = strsep (&p, " ")))
			rc_strlist_addsort (&opts, token);
	}
	pclose (fp);
	return (opts);
}
librc_hidden_def(rc_service_options)

char *rc_service_description (const char *service, const char *option)
{
	char *svc;
	char cmd[PATH_MAX];
	char buffer[RC_LINEBUFFER];
	char *desc = NULL;
	FILE *fp;
	int i;

	if (! (svc = rc_service_resolve (service)))
		return (NULL);

	if (! option)
		option = "";

	snprintf (cmd, sizeof (cmd), ". '%s'; echo \"${description%s%s}\"",
			  svc, option ? "_" : "", option);
	free (svc);
	if (! (fp = popen (cmd, "r")))
		return (NULL);

	while (fgets (buffer, RC_LINEBUFFER, fp)) {
		if (! desc) {
			desc = rc_xmalloc (strlen (buffer) + 1);
			*desc = '\0';
		} else {
			desc = rc_xrealloc (desc, strlen (desc) + strlen (buffer) + 1);
		}
		i = strlen (desc);
		memcpy (desc + i, buffer, strlen (buffer));
		memset (desc + i + strlen (buffer), 0, 1);
	}

	pclose (fp);
	return (desc);
}
librc_hidden_def(rc_service_description)

bool rc_service_in_runlevel (const char *service, const char *runlevel)
{
	char *file;
	bool retval;
	char *svc;

	if (! runlevel || ! service)
		return (false);

	svc = rc_xstrdup (service);
	file = rc_strcatpaths (RC_RUNLEVELDIR, runlevel, basename (svc),
						   (char *) NULL);
	free (svc);
	retval = rc_exists (file);
	free (file);

	return (retval);
}
librc_hidden_def(rc_service_in_runlevel)

bool rc_service_mark (const char *service, const rc_service_state_t state)
{
	char *file;
	int i = 0;
	int skip_state = -1;
	char *base;
	char *svc;
	char *init = rc_service_resolve (service);
	bool skip_wasinactive = false;

	if (! service)
		return (false);

	svc = rc_xstrdup (service);
	base = basename (svc);

	if (state != RC_SERVICE_STOPPED) {
		if (! rc_exists (init)) {
			free (init);
			free (svc);
			return (false);
		}

		file = rc_strcatpaths (RC_SVCDIR, rc_parse_service_state (state), base,
							   (char *) NULL);
		if (rc_exists (file))
			unlink (file);
		i = symlink (init, file);
		if (i != 0)	{
			free (file);
			free (init);
			free (svc);
			return (false);
		}

		free (file);
		skip_state = state;
	}

	if (state == RC_SERVICE_COLDPLUGGED) {
		free (init);
		free (svc);
		return (true);
	}

	/* Remove any old states now */
	for (i = 0; rc_service_state_names[i].name; i++) {
		int s = rc_service_state_names[i].state;

		if ((s != skip_state &&
			 s != RC_SERVICE_STOPPED &&
			 s != RC_SERVICE_COLDPLUGGED &&
			 s != RC_SERVICE_SCHEDULED) &&
			(! skip_wasinactive || s != RC_SERVICE_WASINACTIVE))
		{
			file = rc_strcatpaths (RC_SVCDIR, rc_parse_service_state(s), base,
								   (char *) NULL);
			if (rc_exists (file)) {
				if ((state == RC_SERVICE_STARTING ||
					 state == RC_SERVICE_STOPPING) &&
					s == RC_SERVICE_INACTIVE)
				{
					char *wasfile = rc_strcatpaths (RC_SVCDIR,
													rc_parse_service_state (RC_SERVICE_WASINACTIVE),
													base, (char *) NULL);

					symlink (init, wasfile);
					skip_wasinactive = true;
					free (wasfile);
				}
				unlink (file);
			}
			free (file);
		}
	}

	/* Remove the exclusive state if we're inactive */
	if (state == RC_SERVICE_STARTED ||
		state == RC_SERVICE_STOPPED ||
		state == RC_SERVICE_INACTIVE)
	{
		file = rc_strcatpaths (RC_SVCDIR, "exclusive", base, (char *) NULL);
		unlink (file); 
		free (file);
	}

	/* Remove any options and daemons the service may have stored */
	if (state == RC_SERVICE_STOPPED) {
		char *dir = rc_strcatpaths (RC_SVCDIR, "options", base, (char *) NULL);
		rm_dir (dir, true);
		free (dir);

		dir = rc_strcatpaths (RC_SVCDIR, "daemons", base, (char *) NULL);
		rm_dir (dir, true);
		free (dir);

		rc_service_schedule_clear (service);
	}

	/* These are final states, so remove us from scheduled */
	if (state == RC_SERVICE_STARTED || state == RC_SERVICE_STOPPED) {
		char *sdir = rc_strcatpaths (RC_SVCDIR, "scheduled", (char *) NULL);
		char **dirs = ls_dir (sdir, 0);
		char *dir;
		int serrno;

		STRLIST_FOREACH (dirs, dir, i) {
			char *bdir = rc_strcatpaths (sdir, dir, (char *) NULL);
			file = rc_strcatpaths (bdir, base, (char *) NULL);
			unlink (file);
			free (file);

			/* Try and remove the dir - we don't care about errors */
			serrno = errno;
			rmdir (bdir);
			errno = serrno;
			free (bdir);
		}
		rc_strlist_free (dirs);
		free (sdir);
	}

	free (svc);
	free (init);
	return (true);
}
librc_hidden_def(rc_service_mark)

rc_service_state_t rc_service_state (const char *service)
{
	int i;
	int state = RC_SERVICE_STOPPED;
	char *svc = rc_xstrdup (service);

	for (i = 0; rc_service_state_names[i].name; i++) {
		char *file = rc_strcatpaths (RC_SVCDIR, rc_service_state_names[i].name,
									 basename (svc), (char*) NULL);
		if (rc_exists (file)) {
			if (rc_service_state_names[i].state <= 0x10)
				state = rc_service_state_names[i].state;
			else
				state |= rc_service_state_names[i].state;
		}
		free (file);
	}
	free (svc);

	if (state & RC_SERVICE_STOPPED) {
		char **services = rc_services_scheduled_by (service);
		if (services) {
			state |= RC_SERVICE_SCHEDULED;
			free (services);
		}
	}

	return (state);
}
librc_hidden_def(rc_service_state)

char *rc_service_value_get (const char *service, const char *option)
{
	FILE *fp;
	char buffer[RC_LINEBUFFER];
	char *file = rc_strcatpaths (RC_SVCDIR, "options", service, option,
								 (char *) NULL);
	char *value = NULL;

	if ((fp = fopen (file, "r"))) {
		memset (buffer, 0, sizeof (buffer));
		if (fgets (buffer, RC_LINEBUFFER, fp)) 
			value = rc_xstrdup (buffer);
		fclose (fp);
	}
	free (file);

	return (value);
}
librc_hidden_def(rc_service_value_get)

bool rc_service_value_set (const char *service, const char *option,
						   const char *value)
{
	FILE *fp;
	char *path = rc_strcatpaths (RC_SVCDIR, "options", service, (char *) NULL);
	char *file = rc_strcatpaths (path, option, (char *) NULL);
	bool retval = false;

	if (mkdir (path, 0755) != 0 && errno != EEXIST) {
		free (path);
		free (file);
		return (false);
	}

	if ((fp = fopen (file, "w"))) {
		if (value)
			fprintf (fp, "%s", value);
		fclose (fp);
		retval = true;
	}

	free (path);
	free (file);
	return (retval);
}
librc_hidden_def(rc_service_value_set)

static pid_t _exec_service (const char *service, const char *arg)
{
	char *file;
	char *fifo;
	pid_t pid = -1;
	char *svc;

	file = rc_service_resolve (service);
	if (! rc_exists (file)) {
		rc_service_mark (service, RC_SERVICE_STOPPED);
		free (file);
		return (0);
	}

	/* We create a fifo so that other services can wait until we complete */
	svc = rc_xstrdup (service);
	fifo = rc_strcatpaths (RC_SVCDIR, "exclusive", basename (svc),
						   (char *) NULL);
	free (svc);

	if (mkfifo (fifo, 0600) != 0 && errno != EEXIST) {
		free (fifo);
		free (file);
		return (-1);
	}

	if ((pid = vfork ()) == 0) {
		execl (file, file, arg, (char *) NULL);
		fprintf (stderr, "unable to exec `%s': %s\n", file, strerror (errno));
		unlink (fifo);
		_exit (EXIT_FAILURE);
	}

	free (fifo);
	free (file);

	if (pid == -1)
		fprintf (stderr, "vfork: %s\n", strerror (errno));

	return (pid);
}

pid_t rc_service_stop (const char *service)
{
	if (rc_service_state (service) & RC_SERVICE_STOPPED)
		return (0);

	return (_exec_service (service, "stop"));
}
librc_hidden_def(rc_service_stop)

pid_t rc_service_start (const char *service)
{
	if (! rc_service_state (service) & RC_SERVICE_STOPPED)
		return (0);

	return (_exec_service (service, "start"));
}
librc_hidden_def(rc_service_start)

bool rc_service_schedule_start (const char *service,
								const char *service_to_start)
{
	char *dir;
	char *init;
	char *file;
	char *svc;
	bool retval;

	/* service may be a provided service, like net */
	if (! service || ! rc_service_exists (service_to_start))
		return (false);

	svc = rc_xstrdup (service);
	dir = rc_strcatpaths (RC_SVCDIR, "scheduled", basename (svc),
						  (char *) NULL);
	free (svc);
	if (mkdir (dir, 0755) != 0 && errno != EEXIST) {
		free (dir);
		return (false);
	}

	init = rc_service_resolve (service_to_start);
	svc = rc_xstrdup (service_to_start);
	file = rc_strcatpaths (dir, basename (svc), (char *) NULL);
	free (svc);
	retval = (rc_exists (file) || symlink (init, file) == 0);
	free (init);
	free (file);
	free (dir);

	return (retval);
}
librc_hidden_def(rc_service_schedule_start)

bool rc_service_schedule_clear (const char *service)
{
	char *svc  = rc_xstrdup (service);
	char *dir = rc_strcatpaths (RC_SVCDIR, "scheduled", basename (svc),
								(char *) NULL);
	bool retval;

	free (svc);
	if (! (retval = rm_dir (dir, true)) && errno == ENOENT)
		retval = true;
	free (dir);
	return (retval);
}
librc_hidden_def(rc_service_schedule_clear)

bool rc_service_wait (const char *service)
{
	char *svc;
	char *base;
	char *fifo;
	struct timespec ts;
	int nloops = WAIT_MAX / WAIT_INTERVAL;
	bool retval = false;
	bool forever = false;

	if (! service)
		return (false);

	svc = rc_xstrdup (service);
	base = basename (svc);
	fifo = rc_strcatpaths (RC_SVCDIR, "exclusive", base, (char *) NULL);
	/* FIXME: find a better way of doing this
	 * Maybe a setting in the init script? */
	if (strcmp (base, "checkfs") == 0 || strcmp (base, "checkroot") == 0)
		forever = true;
	free (svc);

	ts.tv_sec = 0;
	ts.tv_nsec = WAIT_INTERVAL;

	while (nloops) {
		if (! rc_exists (fifo)) {
			retval = true;
			break;
		}

		if (nanosleep (&ts, NULL) == -1) {
			if (errno != EINTR)
				break;
		}

		if (! forever)
			nloops --;
	}

	free (fifo);
	return (retval);
}
librc_hidden_def(rc_service_wait)

char **rc_services_in_runlevel (const char *runlevel)
{
	char *dir;
	char **list = NULL;

	if (! runlevel)
		return (ls_dir (RC_INITDIR, LS_INITD));

	/* These special levels never contain any services */
	if (strcmp (runlevel, RC_LEVEL_SYSINIT) == 0 ||
		strcmp (runlevel, RC_LEVEL_SINGLE) == 0)
		return (NULL);

	dir = rc_strcatpaths (RC_RUNLEVELDIR, runlevel, (char *) NULL);
	list = ls_dir (dir, LS_INITD);
	free (dir);
	return (list);
}
librc_hidden_def(rc_services_in_runlevel)

char **rc_services_in_state (rc_service_state_t state)
{
	char *dir = rc_strcatpaths (RC_SVCDIR, rc_parse_service_state (state),
								(char *) NULL);
	char **list = NULL;

	if (state == RC_SERVICE_SCHEDULED) {
		char **dirs = ls_dir (dir, 0);
		char *d;
		int i;

		STRLIST_FOREACH (dirs, d, i) {
			char *p = rc_strcatpaths (dir, d, (char *) NULL);
			char **entries = ls_dir (p, LS_INITD);
			char *e;
			int j;

			STRLIST_FOREACH (entries, e, j)
				rc_strlist_addsortu (&list, e);

			if (entries)
				free (entries);
		}

		if (dirs)
			free (dirs);
	} else {
		list = ls_dir (dir, LS_INITD);
	}

	free (dir);
	return (list);
}
librc_hidden_def(rc_services_in_state)

bool rc_service_add (const char *runlevel, const char *service)
{
	bool retval;
	char *init;
	char *file;
	char *svc;

	if (! rc_runlevel_exists (runlevel)) {
		errno = ENOENT;
		return (false);
	}

	if (rc_service_in_runlevel (service, runlevel)) {
		errno = EEXIST;
		return (false);
	}

	init = rc_service_resolve (service);
	svc = rc_xstrdup (service);
	file = rc_strcatpaths (RC_RUNLEVELDIR, runlevel, basename (svc),
						   (char *) NULL);
	free (svc);
	retval = (symlink (init, file) == 0);
	free (init);
	free (file);
	return (retval);
}
librc_hidden_def(rc_service_add)

bool rc_service_delete (const char *runlevel, const char *service)
{
	char *file;
	char *svc;
	bool retval = false;

	if (! runlevel || ! service)
		return (false);

	svc = rc_xstrdup (service);
	file = rc_strcatpaths (RC_RUNLEVELDIR, runlevel, basename (svc),
						   (char *) NULL);
	free (svc);
	if (unlink (file) == 0)
		retval = true;

	free (file);
	return (retval);
}
librc_hidden_def(rc_service_delete)

char **rc_services_scheduled_by (const char *service)
{
	char **dirs = ls_dir (RC_SVCDIR "/scheduled", 0);
	char **list = NULL;
	char *dir;
	int i;

	STRLIST_FOREACH (dirs, dir, i) {
		char *file = rc_strcatpaths (RC_SVCDIR, "scheduled", dir, service,
									 (char *) NULL);
		if (rc_exists (file))
			rc_strlist_add (&list, file);
		free (file);
	}
	rc_strlist_free (dirs);

	return (list);
}
librc_hidden_def(rc_services_scheduled_by)

char **rc_services_scheduled (const char *service)
{
	char *svc = rc_xstrdup (service);
	char *dir = rc_strcatpaths (RC_SVCDIR, "scheduled", basename (svc),
								(char *) NULL);
	char **list = NULL;

	free (svc);
	list = ls_dir (dir, LS_INITD);
	free (dir);
	return (list);
}
librc_hidden_def(rc_services_scheduled)

bool rc_service_plugable (char *service)
{
	char *list;
	char *p;
	char *star;
	char *token;
	bool allow = true;
	char *match = getenv ("RC_PLUG_SERVICES");
	if (! match)
		return true;

	list = rc_xstrdup (match);
	p = list;
	while ((token = strsep (&p, " "))) {
		bool truefalse = true;
		if (token[0] == '!') {
			truefalse = false;
			token++;
		}

		star = strchr (token, '*');
		if (star) {
			if (strncmp (service, token, star - token) == 0) {
				allow = truefalse;
				break;
			}
		} else {
			if (strcmp (service, token) == 0) {
				allow = truefalse;
				break;
			}
		}
	}

	free (list);
	return (allow);
}
librc_hidden_def(rc_service_plugable)