Convert finit to use libev and fix so plugin ctors runs on dlopen().

Lots of cleanup and simplification of the main code in this commit.
Most notably libev has been added to take care of the main loop and
monitor services. Still TODO is migrating to use the libev signal
handling.

Convert initctl.c:listen_initctl() to a plugin instead.  This also
meant introducing a new form of I/O plugin to finit, also handled
by libev.

Load plugins *after* we've setup the base filesystem (BASEFS) in case
plugins reside on a filesystem not reachable before "mount -a" has run.
This also has the side effect of lining up nicely with the first level
plugin hooks.

If a plugin wants to hook up with a loded service we connect them by
their respective numeric IDs in plugin_register().  I.e., the service
monitor checks if a service has a registered callback, which in turn
decides if a service should be started, stopped or reloaded.

Rip out old EeePC distribution defines from finit.h, none of it really
applies anymore.  If you need distribution specific settings this is
the place to put them.

Make hookpoint names (#defines) clearer: after BASEFS, after networking,
after all setup, etc.

Use #inlude_next <signal.h> in signal.h to include system header file!

Simplify service monitor: move essential code to svc.c and rip out
the TIPC dependency. Write your own service.so plugin, or wait for
a more complete example of how to extend service monitoring using
the primitives in svc.c

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

plugin.c

@@ -24,11 +24,14 @@
 #include <errno.h>
 #include <dlfcn.h>		/* dlopen() et al */
 #include <dirent.h>		/* readdir() et al */
-#include <stdio.h>
 #include <string.h>
 #include <sys/queue.h>		/* BSD sys/queue.h API */
 
+#include "finit.h"
+#include "private.h"
+#include "helpers.h"
 #include "plugin.h"
+#include "svc.h"
 
 static LIST_HEAD(, plugin) plugins = LIST_HEAD_INITIALIZER();
 
@@ -45,8 +48,20 @@ int plugin_register(plugin_t *plugin)
 		if (!dladdr(plugin, &info) || !info.dli_fname)
 			plugin->name = "unknown";
 		else
-			plugin->name = info.dli_fname;
+			plugin->name = (char *)info.dli_fname;
 	}
+
+	if (plugin->svc.cb) {
+		svc_t *svc = svc_find_by_name(plugin->name);
+
+		if (!svc) {
+			_e("No service \"%s\" loaded, skipping plugin.", basename(plugin->name));
+			return 1;
+		}
+		plugin->svc.id = svc_id(svc);
+		svc->plugin    = &plugin->svc;
+	}
+
 	LIST_INSERT_HEAD(&plugins, plugin, link);
 
 	return 0;
@@ -59,13 +74,14 @@ int plugin_unregister(plugin_t *plugin)
 	return 0;
 }
 
+/* Private daemon API *******************************************************/
 void run_hooks(hook_point_t no)
 {
 	plugin_t *p;
 
 	PLUGIN_ITERATOR(p) {
 		if (p->hook[no].cb) {
-			printf("Calling %s hook n:o %d from runloop...\n", p->name, no);
+			_d("Calling %s hook n:o %d from runloop...", basename(p->name), no);
 			p->hook[no].cb(p->hook[no].arg);
 		}
 	}
@@ -77,20 +93,57 @@ void run_services(void)
 
 	PLUGIN_ITERATOR(p) {
 		if (p->svc.cb) {
-			printf("Calling svc %s from runloop...\n", p->name);
-			p->svc.cb(p->svc.arg);
+			_d("Calling svc %s from runloop...", basename(p->name));
+			p->svc.cb(p->svc.arg, 0);
 		}
 	}
 }
 
-int load_plugins(char *path)
+/* Generic libev I/O callback, looks up correct plugin and calls its callback */
+static void generic_io_cb(struct ev_loop *loop, ev_io *w, int revents)
+{
+	plugin_t *p;
+
+	ev_io_stop(loop, w);
+
+	/* Find matching plugin, pick first matching fd */
+	PLUGIN_ITERATOR(p) {
+		if (p->io.cb && p->io.fd == w->fd) {
+			p->io.cb(p->io.arg, w->fd, revents);
+			break;
+		}
+	}
+
+	ev_io_start(loop, w);
+}
+
+/* Setup any I/O callbacks for plugins that use them */
+static void init_plugins(struct ev_loop *loop)
+{
+	plugin_t *p;
+
+	PLUGIN_ITERATOR(p) {
+		if (p->io.cb && p->io.fd >= 0) {
+			ev_io *w = calloc(1, sizeof(ev_io));
+
+			_d("Initializing plugin %s for I/O", basename(p->name));
+			if (!w) {
+				_e("Failed setting up plugin %s: Out of memory", basename(p->name));
+				continue;
+			}
+			ev_io_init(w, generic_io_cb, p->io.fd, p->io.flags);
+			ev_io_start(loop, w);
+		}
+	}
+}
+
+int load_plugins(struct ev_loop *loop, char *path)
 {
 	DIR *dp = opendir(path);
 	struct dirent *entry;
 
 	if (!dp) {
-		fprintf(stderr, "Failed, cannot open plugin directory %s: %s\n",
-			path, strerror(errno));
+		_e("Failed, cannot open plugin directory %s: %s", path, strerror(errno));
 		return 1;
 	}
 
@@ -102,17 +155,19 @@ int load_plugins(char *path)
 			char filename[1024];
 
 			snprintf(filename, sizeof(filename), "%s/%s", path, entry->d_name);
-			printf("Loading plugin %s ...\n", filename);
+			print_descr("   Loading plugin ", basename(filename));
 			handle = dlopen(filename, RTLD_LAZY);
 			if (!handle) {
-				fprintf(stderr,
-					"Failed loading plugin %s: %s\n", filename, dlerror());
+				_d("Failed loading plugin %s: %s", filename, dlerror());
+				print_result(1);
 				return 1;
 			}
+			print_result(0);
 		}
 	}
 
 	closedir(dp);
+	init_plugins(loop);
 
 	return 0;
 }