support for dynamic multiplexing of services

man/openrc-run.8

@@ -547,6 +547,9 @@ sets the following environment variables for use in the service scripts:
 Name of the service.
 .It Va RC_SERVICE
 Full path to the service.
+.It Va RC_SCRIPTDIR
+Full path to the system directory the service lives in. For multiplexed
+services, it is the directory the main service live in.
 .It Va RC_RUNLEVEL
 Current runlevel that OpenRC is in. Note that, in OpenRC, the reboot
 runlevel is mapped to the shutdown runlevel. This was done because most
@@ -584,14 +587,14 @@ should not be unmounted.
 .El
 .Sh FILES
 .Pp
-Configuration files, relative to the location of the service.
+Configuration files, relative to RC_SYSCONFDIR.
 If a file ending with .${RC_RUNLEVEL} exists then we use that instead.
 .Bl -ohang
-.It Pa ../conf.d/${RC_SVCNAME%%.*}
+.It Pa ${RC_SCRIPTDIR}/conf.d/${RC_SVCNAME%%.*}
 multiplexed configuration file.
 Example: if ${RC_SVCNAME} is net.eth1 then look for
-.Pa ../conf.d/net .
-.It Pa ../conf.d/${RC_SVCNAME}
+.Pa ${RC_SCRIPTDIR}/conf.d/net .
+.It Pa ${RC_SCRIPTDIR}/conf.d/${RC_SVCNAME}
 service configuration file.
 .It Pa /etc/rc.conf
 host configuration file.

sh/openrc-run.sh.in

@@ -220,7 +220,7 @@ if [ -d "@SYSCONFDIR@/rc.conf.d" ]; then
 	done
 fi
 
-_conf_d=${RC_SERVICE%/*}/../conf.d
+_conf_d="${RC_SCRIPTDIR}/conf.d"
 # If we're net.eth0 or openvpn.work then load net or openvpn config
 _c=${RC_SVCNAME%%.*}
 if [ -n "$_c" -a "$_c" != "$RC_SVCNAME" ]; then

src/librc/librc-depend.c

@@ -697,6 +697,7 @@ static const char *const depdirs[] =
 	RC_SVCDIR "/wasinactive",
 	RC_SVCDIR "/failed",
 	RC_SVCDIR "/hotplugged",
+	RC_SVCDIR "/multiplexed",
 	RC_SVCDIR "/daemons",
 	RC_SVCDIR "/options",
 	RC_SVCDIR "/exclusive",

src/librc/librc.c

@@ -636,6 +636,12 @@ rc_service_resolve(const char *service)
 		return file;
 #endif
 
+	/* Check dynamically multiplexed services last */
+	free(file);
+	xasprintf(&file, "%s/multiplexed/%s", RC_SVCDIR, service);
+	if (stat(file, &buf) == 0)
+		return file;
+
 	free(file);
 	return NULL;
 }
@@ -933,6 +939,32 @@ rc_service_state(const char *service)
 	return state;
 }
 
+char *
+rc_service_multiplex(const char *base, const char *variant)
+{
+	char *service = rc_service_resolve(base);
+	char *target;
+	char *name;
+
+	if (!service)
+		return NULL;
+
+	if (base[0] == '/')
+		base = basename_c(base);
+
+	xasprintf(&name, "%s.%s", base, variant);
+
+	xasprintf(&target, "%s/multiplexed/%s", RC_SVCDIR, name);
+	if (!exists(target) && symlink(service, target) == -1) {
+		free(target);
+		target = NULL;
+	}
+
+	free(name);
+	free(service);
+	return target;
+}
+
 char *
 rc_service_value_get(const char *service, const char *option)
 {
@@ -1119,6 +1151,8 @@ rc_service_add(const char *runlevel, const char *service)
 	char *path;
 	char *binit = NULL;
 	char *i;
+	char *multiplex_dir;
+	int len;
 
 	if (!rc_runlevel_exists(runlevel)) {
 		errno = ENOENT;
@@ -1151,10 +1185,20 @@ rc_service_add(const char *runlevel, const char *service)
 		i = binit;
 	}
 
-	xasprintf(&file, "%s/%s/%s", RC_RUNLEVELDIR, runlevel,
-		basename_c(service));
+	/* We shouldn't add any dynamically multiplexed service to a runlevel */
+	len = xasprintf(&multiplex_dir, "%s/multiplexed", RC_SVCDIR);
+	if (strncmp(i, multiplex_dir, len) == 0) {
+		errno = ENOENT;
+		retval = false;
+		goto out;
+	}
+
+	xasprintf(&file, "%s/%s/%s", RC_RUNLEVELDIR, runlevel, basename_c(service));
 	retval = (symlink(i, file) == 0);
 	free(file);
+
+out:
+	free(multiplex_dir);
 	free(binit);
 	free(init);
 	return retval;

src/librc/rc.h.in

@@ -267,6 +267,11 @@ bool rc_service_schedule_clear(const char *);
  * @return state of the service */
 RC_SERVICE rc_service_state(const char *);
 
+/*! Dynamically multiplexes a base service into a variant as basename.variant
+ * @param basename or full path of service being multiplexed
+ * @param variant to dynamically multiplex */
+char *rc_service_multiplex(const char *, const char *);
+
 /*! Check if the service started the daemon
  * @param service to check
  * @param exec to check

src/openrc-run/openrc-run.c

@@ -21,6 +21,7 @@
 #include <fnmatch.h>
 #include <getopt.h>
 #include <libgen.h>
+#include <limits.h>
 #include <poll.h>
 #include <signal.h>
 #include <stdio.h>
@@ -209,21 +210,21 @@ restore_state(void)
 
 	if (rc_in_plugin || exclusive_fd == -1)
 		return;
-	state = rc_service_state(applet);
+	state = rc_service_state(service);
 	if (state & RC_SERVICE_STOPPING) {
 		if (state & RC_SERVICE_WASINACTIVE)
-			rc_service_mark(applet, RC_SERVICE_INACTIVE);
+			rc_service_mark(service, RC_SERVICE_INACTIVE);
 		else
-			rc_service_mark(applet, RC_SERVICE_STARTED);
+			rc_service_mark(service, RC_SERVICE_STARTED);
 		if (rc_runlevel_stopping())
-			rc_service_mark(applet, RC_SERVICE_FAILED);
+			rc_service_mark(service, RC_SERVICE_FAILED);
 	} else if (state & RC_SERVICE_STARTING) {
 		if (state & RC_SERVICE_WASINACTIVE)
-			rc_service_mark(applet, RC_SERVICE_INACTIVE);
+			rc_service_mark(service, RC_SERVICE_INACTIVE);
 		else
-			rc_service_mark(applet, RC_SERVICE_STOPPED);
+			rc_service_mark(service, RC_SERVICE_STOPPED);
 		if (rc_runlevel_starting())
-			rc_service_mark(applet, RC_SERVICE_FAILED);
+			rc_service_mark(service, RC_SERVICE_FAILED);
 	}
 	exclusive_fd = svc_unlock(applet, exclusive_fd);
 }
@@ -1094,17 +1095,73 @@ service_plugable(void)
 	return allow;
 }
 
+static char *
+normalize_path(const char *src)
+{
+	char *path;
+	size_t path_len;
+	size_t src_len = strlen(src);
+
+	if (src_len == 0 || src[0] != '/') {
+		char pwd[PATH_MAX];
+		size_t pwd_len;
+
+		if (getcwd(pwd, sizeof(pwd)) == NULL)
+			return NULL;
+
+		pwd_len = strlen(pwd);
+		path = xmalloc(pwd_len + 1 + src_len + 1);
+		memcpy(path, pwd, pwd_len);
+		path_len = pwd_len;
+	} else {
+		path = xmalloc((src_len > 0 ? src_len : 1) + 1);
+		path_len = 0;
+	}
+
+	for (const char *ptr = src, *next; ptr < src + src_len; ptr = next + 1) {
+		size_t len;
+		next = strchr(ptr, '/');
+		if (!next)
+			next = src + src_len;
+		len = next - ptr;
+		switch (len) {
+			case 2:
+				if (ptr[0] == '.' && ptr[1] == '.') {
+					const char *slash = strrchr(path, '/');
+					if (slash)
+						path_len = slash - path;
+					continue;
+				}
+				break;
+			case 1:
+				if (ptr[0] == '.')
+					continue;
+				break;
+			case 0:
+				continue;
+		}
+		path[path_len++] = '/';
+		memcpy(&path[path_len], ptr, len);
+		path_len += len;
+	}
+
+	if (path_len == 0)
+		path[path_len++] = '/';
+
+	path[path_len] = '\0';
+	return path;
+}
+
 int main(int argc, char **argv)
 {
 	bool doneone = false;
 	int retval, opt, depoptions = RC_DEP_TRACE;
 	RC_STRING *svc;
-	char *path = NULL;
-	char *lnk = NULL;
-	char *dir, *save = NULL, *saveLnk = NULL;
+	char service_path[PATH_MAX];
+	char *initdir, *scriptdir;
+	char *save;
 	char *pidstr = NULL;
 	size_t l = 0, ll;
-	const char *file;
 	struct stat stbuf;
 
 	/* Show help if insufficient args */
@@ -1113,53 +1170,30 @@ int main(int argc, char **argv)
 		exit(EXIT_FAILURE);
 	}
 
-	applet = basename_c(argv[0]);
-
 	if (stat(argv[1], &stbuf) != 0) {
-		fprintf(stderr, "openrc-run `%s': %s\n",
-		    argv[1], strerror(errno));
+		fprintf(stderr, "openrc-run '%s': %s\n", argv[1], strerror(errno));
 		exit(EXIT_FAILURE);
 	}
 
-	atexit(cleanup);
-
 	/* We need to work out the real full path to our service.
-	 * This works fine, provided that we ONLY allow multiplexed services
-	 * to exist in the same directory as the master link.
-	 * Also, the master link as to be a real file in the init dir. */
-	path = realpath(argv[1], NULL);
-	if (!path) {
+	 * multiplexed services must point to a target in a init dir. */
+	if (!realpath(argv[1], service_path)) {
 		fprintf(stderr, "realpath: %s\n", strerror(errno));
 		exit(EXIT_FAILURE);
 	}
-	lnk = xmalloc(4096);
-	memset(lnk, 0, 4096);
-	if (readlink(argv[1], lnk, 4096-1)) {
-		dir = dirname(path);
-		if (strchr(lnk, '/')) {
-			save = xstrdup(dir);
-			saveLnk = xstrdup(lnk);
-			dir = dirname(saveLnk);
-			if (strcmp(dir, save) == 0)
-				file = basename_c(argv[1]);
-			else
-				file = basename_c(lnk);
-			dir = save;
-		} else
-			file = basename_c(argv[1]);
-		xasprintf(&service, "%s/%s", dir, file);
-		if (stat(service, &stbuf) != 0) {
-			free(service);
-			service = xstrdup(lnk);
-		}
-		free(save);
-		free(saveLnk);
+	scriptdir = dirname(service_path);
+	initdir = strrchr(scriptdir, '/');
+	if (!initdir || strcmp(initdir, "/init.d") != 0) {
+		fprintf(stderr, "%s is not an init dir", service_path);
+		exit(EXIT_FAILURE);
 	}
-	free(lnk);
-	if (!service)
-		service = xstrdup(path);
+	*initdir = '\0';
+
+	service = normalize_path(argv[1]);
 	applet = basename_c(service);
 
+	atexit(cleanup);
+
 	if (argc < 3)
 		usage(EXIT_FAILURE);
 
@@ -1175,6 +1209,7 @@ int main(int argc, char **argv)
 
 	setenv("EINFO_LOG", service, 1);
 	setenv("RC_SVCNAME", applet, 1);
+	setenv("RC_SCRIPTDIR", scriptdir, true);
 
 	/* Set an env var so that we always know our pid regardless of any
 	   subshells the init script may create so that our mark_service_*
@@ -1392,7 +1427,7 @@ int main(int argc, char **argv)
 			} else if (strcmp(optarg, "zap") == 0) {
 				einfo("Manually resetting %s to stopped state",
 				    applet);
-				if (!rc_service_mark(applet,
+				if (!rc_service_mark(service,
 					RC_SERVICE_STOPPED))
 					eerrorx("rc_service_mark: %s",
 					    strerror(errno));