plugins: add and install built-in plugin dir, add clear and disable options.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Makefile

@@ -401,6 +401,7 @@ exec_prefix = $(prefix)
 bindir = $(exec_prefix)/bin
 libexecdir = $(exec_prefix)/libexec
 pkglibexecdir = $(libexecdir)/$(PKGNAME)
+plugindir = $(pkglibexecdir)/plugins
 datadir = $(prefix)/share
 docdir = $(datadir)/doc/$(PKGNAME)
 mandir = $(datadir)/man
@@ -427,6 +428,7 @@ installdirs:
 	@$(NORMAL_INSTALL)
 	$(MKDIR_P) $(DESTDIR)$(bindir)
 	$(MKDIR_P) $(DESTDIR)$(pkglibexecdir)
+	$(MKDIR_P) $(DESTDIR)$(plugindir)
 	$(MKDIR_P) $(DESTDIR)$(man1dir)
 	$(MKDIR_P) $(DESTDIR)$(man5dir)
 	$(MKDIR_P) $(DESTDIR)$(man7dir)
@@ -446,11 +448,13 @@ PKGLIBEXEC_PROGRAMS = \
 	       lightningd/lightning_hsmd \
 	       lightningd/lightning_onchaind \
 	       lightningd/lightning_openingd
+PLUGINS=
 
 install-program: installdirs $(BIN_PROGRAMS) $(PKGLIBEXEC_PROGRAMS)
 	@$(NORMAL_INSTALL)
 	$(INSTALL_PROGRAM) $(BIN_PROGRAMS) $(DESTDIR)$(bindir)
 	$(INSTALL_PROGRAM) $(PKGLIBEXEC_PROGRAMS) $(DESTDIR)$(pkglibexecdir)
+	[ -z "$(PLUGINS)" ] || $(INSTALL_PROGRAM) $(PLUGINS) $(DESTDIR)$(plugindir)
 
 MAN1PAGES = $(filter %.1,$(MANPAGES))
 MAN5PAGES = $(filter %.5,$(MANPAGES))
@@ -472,6 +476,10 @@ uninstall:
 	  echo rm -f $(DESTDIR)$(bindir)/`basename $$f`; \
 	  rm -f $(DESTDIR)$(bindir)/`basename $$f`; \
 	done
+	@for f in $(PLUGINS); do \
+	  echo rm -f $(DESTDIR)$(plugindir)/`basename $$f`; \
+	  rm -f $(DESTDIR)$(plugindir)/`basename $$f`; \
+	done
 	@for f in $(PKGLIBEXEC_PROGRAMS); do \
 	  echo rm -f $(DESTDIR)$(pkglibexecdir)/`basename $$f`; \
 	  rm -f $(DESTDIR)$(pkglibexecdir)/`basename $$f`; \

lightningd/lightningd.c

@@ -339,7 +339,7 @@ static const char *find_my_directory(const tal_t *ctx, const char *argv0)
  *
  * TAKES is only a convention unfortunately, and ignored by the compiler.
  */
-static const char *find_my_pkglibexec_path(const tal_t *ctx,
+static const char *find_my_pkglibexec_path(struct lightningd *ld,
 					   const char *my_path TAKES)
 {
 	const char *pkglibexecdir;
@@ -352,23 +352,34 @@ static const char *find_my_pkglibexec_path(const tal_t *ctx,
 	 * So, as we promised with 'TAKES' in our own declaration, if the
 	 * caller has called `take()` the `my_path` parameter, path_join()
 	 * will free it. */
-	pkglibexecdir = path_join(ctx, my_path, BINTOPKGLIBEXECDIR);
+	pkglibexecdir = path_join(NULL, my_path, BINTOPKGLIBEXECDIR);
+
+	/*~ The plugin dir is in ../libexec/c-lightning/plugins, which (unlike
+	 * those given on the command line) does not need to exist. */
+	add_plugin_dir(ld->plugins,
+		       path_join(tmpctx, pkglibexecdir, "plugins"),
+		       true);
 
 	/*~ Sometimes take() can be more efficient, since the routine can
 	 * manipulate the string in place.  This is the case here. */
-	return path_simplify(ctx, take(pkglibexecdir));
+	return path_simplify(ld, take(pkglibexecdir));
 }
 
 /* Determine the correct daemon dir. */
-static const char *find_daemon_dir(const tal_t *ctx, const char *argv0)
+static const char *find_daemon_dir(struct lightningd *ld, const char *argv0)
 {
-	const char *my_path = find_my_directory(ctx, argv0);
+	const char *my_path = find_my_directory(ld, argv0);
 	/* If we're running in-tree, all the subdaemons are with lightningd. */
-	if (has_all_subdaemons(my_path))
+	if (has_all_subdaemons(my_path)) {
+		/* In this case, look in ../plugins */
+		add_plugin_dir(ld->plugins,
+			       path_join(tmpctx, my_path, "../plugins"),
+			       true);
 		return my_path;
+	}
 
 	/* Otherwise we assume they're in the installed dir. */
-	return find_my_pkglibexec_path(ctx, take(my_path));
+	return find_my_pkglibexec_path(ld, take(my_path));
 }
 
 /*~ We like to free everything on exit, so valgrind doesn't complain (valgrind

lightningd/options.c

@@ -293,9 +293,22 @@ static char *opt_add_plugin(const char *arg, struct lightningd *ld)
 	return NULL;
 }
 
+static char *opt_disable_plugin(const char *arg, struct lightningd *ld)
+{
+	if (plugin_remove(ld->plugins, arg))
+		return NULL;
+	return tal_fmt(NULL, "Could not find plugin %s", arg);
+}
+
 static char *opt_add_plugin_dir(const char *arg, struct lightningd *ld)
 {
-	return add_plugin_dir(ld->plugins, arg);
+	return add_plugin_dir(ld->plugins, arg, false);
+}
+
+static char *opt_clear_plugins(struct lightningd *ld)
+{
+	clear_plugins(ld->plugins);
+	return NULL;
 }
 
 static void config_register_opts(struct lightningd *ld)
@@ -304,13 +317,19 @@ static void config_register_opts(struct lightningd *ld)
 		&ld->config_filename,
 		"Specify configuration file. Relative paths will be prefixed by lightning-dir location. (default: config)");
 
-	/* Register plugins as an early argc, so we can initialize them and have
+	/* Register plugins as an early args, so we can initialize them and have
 	 * them register more command line options */
 	opt_register_early_arg("--plugin", opt_add_plugin, NULL, ld,
 			       "Add a plugin to be run (can be used multiple times)");
 	opt_register_early_arg("--plugin-dir", opt_add_plugin_dir,
 			       NULL, ld,
 			       "Add a directory to load plugins from (can be used multiple times)");
+	opt_register_early_noarg("--clear-plugins", opt_clear_plugins,
+				 ld,
+				 "Remove all plugins added before this option");
+	opt_register_early_arg("--disable-plugin", opt_disable_plugin,
+			       NULL, ld,
+			       "Disable a particular plugin by filename/name");
 
 	opt_register_noarg("--daemon", opt_set_bool, &ld->daemon,
 			 "Run in the background, suppress stdout/stderr");
@@ -924,7 +943,9 @@ static void add_config(struct lightningd *ld,
 		    || opt->cb == (void *)opt_set_testnet
 		    || opt->cb == (void *)opt_set_mainnet
 		    || opt->cb == (void *)opt_lightningd_usage
-		    || opt->cb == (void *)test_subdaemons_and_exit) {
+		    || opt->cb == (void *)test_subdaemons_and_exit
+		    /* FIXME: we can't recover this. */
+		    || opt->cb == (void *)opt_clear_plugins) {
 			/* These are not important */
 		} else if (opt->cb == (void *)opt_set_bool) {
 			const bool *b = opt->u.carg;
@@ -997,9 +1018,10 @@ static void add_config(struct lightningd *ld,
 				answer = fmt_wireaddr(name0, ld->proxyaddr);
 		} else if (opt->cb_arg == (void *)opt_add_plugin) {
 			json_add_opt_plugins(response, ld->plugins);
-		} else if (opt->cb_arg == (void *)opt_add_plugin_dir) {
+		} else if (opt->cb_arg == (void *)opt_add_plugin_dir
+			   || opt->cb_arg == (void *)opt_disable_plugin) {
 			/* FIXME: We actually treat it as if they specified
-			 * --plugin for each one, so ignore this */
+			 * --plugin for each one, so ignore these */
 #if DEVELOPER
 		} else if (strstarts(name, "dev-")) {
 			/* Ignore dev settings */

lightningd/plugin.c

@@ -134,6 +134,41 @@ void plugin_register(struct plugins *plugins, const char* path TAKES)
 	list_head_init(&p->plugin_opts);
 }
 
+static bool paths_match(const char *cmd, const char *name)
+{
+	if (strchr(name, PATH_SEP)) {
+		const char *cmd_canon, *name_canon;
+
+		if (streq(cmd, name))
+			return true;
+
+		/* These return NULL path doesn't exist */
+		cmd_canon = path_canon(tmpctx, cmd);
+		name_canon = path_canon(tmpctx, name);
+		return cmd_canon && name_canon && streq(name_canon, cmd_canon);
+	} else {
+		/* No path separator means a basename match. */
+		const char *base = path_basename(tmpctx, cmd);
+
+		return streq(base, name);
+	}
+}
+
+bool plugin_remove(struct plugins *plugins, const char *name)
+{
+	struct plugin *p, *next;
+	bool removed = false;
+
+	list_for_each_safe(&plugins->plugins, p, next, list) {
+		if (paths_match(p->cmd, name)) {
+			list_del_from(&plugins->plugins, &p->list);
+			tal_free(p);
+			removed = true;
+		}
+	}
+	return removed;
+}
+
 /**
  * Kill a plugin process, with an error message.
  */
@@ -638,13 +673,16 @@ static const char *plugin_fullpath(const tal_t *ctx, const char *dir,
 	return fullname;
 }
 
-char *add_plugin_dir(struct plugins *plugins, const char *dir)
+char *add_plugin_dir(struct plugins *plugins, const char *dir, bool nonexist_ok)
 {
 	struct dirent *di;
 	DIR *d = opendir(dir);
-	if (!d)
+	if (!d) {
+		if (nonexist_ok && errno == ENOENT)
+			return NULL;
 		return tal_fmt("Failed to open plugin-dir %s: %s",
 			       dir, strerror(errno));
+	}
 
 	while ((di = readdir(d)) != NULL) {
 		const char *fullpath;
@@ -658,6 +696,15 @@ char *add_plugin_dir(struct plugins *plugins, const char *dir)
 	return NULL;
 }
 
+void clear_plugins(struct plugins *plugins)
+{
+	struct plugin *p;
+
+	log_info(plugins->log, "clear-plugins removing all plugins");
+	while ((p = list_pop(&plugins->plugins, struct plugin, list)) != NULL)
+		tal_free(p);
+}
+
 void plugins_init(struct plugins *plugins)
 {
 	struct plugin *p;

lightningd/plugin.h

@@ -38,6 +38,15 @@ void plugins_init(struct plugins *plugins);
  */
 void plugin_register(struct plugins *plugins, const char* path TAKES);
 
+
+/**
+ * Remove a plugin registered for initialization.
+ *
+ * @param plugins: Plugin context
+ * @param arg: The basename or fullname of the executable for this plugin
+ */
+bool plugin_remove(struct plugins *plugins, const char *name);
+
 /**
  * Send the configure message to all plugins.
  *
@@ -60,6 +69,12 @@ void json_add_opt_plugins(struct json_stream *response,
 /**
  * Add a directory to the plugin path to automatically load plugins.
  */
-char *add_plugin_dir(struct plugins *plugins, const char *dir);
+char *add_plugin_dir(struct plugins *plugins, const char *dir,
+		     bool nonexist_ok);
+
+/**
+ * Clear all plugins registered so far.
+ */
+void clear_plugins(struct plugins *plugins);
 
 #endif /* LIGHTNING_LIGHTNINGD_PLUGIN_H */

lightningd/test/run-find_my_abspath.c

@@ -9,6 +9,10 @@ int unused_main(int argc, char *argv[]);
 /* Generated stub for activate_peers */
 void activate_peers(struct lightningd *ld UNNEEDED)
 { fprintf(stderr, "activate_peers called!\n"); abort(); }
+/* Generated stub for add_plugin_dir */
+char *add_plugin_dir(struct plugins *plugins UNNEEDED, const char *dir UNNEEDED,
+		     bool nonexist_ok UNNEEDED)
+{ fprintf(stderr, "add_plugin_dir called!\n"); abort(); }
 /* Generated stub for begin_topology */
 void begin_topology(struct chain_topology *topo UNNEEDED)
 { fprintf(stderr, "begin_topology called!\n"); abort(); }

plugins/README.md

@@ -0,0 +1,6 @@
+# Plugin Directory
+
+Anything file in this directory which is executable and doesn't start
+and doesn't contain ASCII symbols other than '.', '-' or '_' will be
+automatically loaded when lightningd starts (unless suppressed with
+commandline options).

tests/test_plugin.py

@@ -1,3 +1,4 @@
+from collections import OrderedDict
 from fixtures import *  # noqa: F401,F403
 from lightning import RpcError
 
@@ -57,3 +58,22 @@ def test_plugin_dir(node_factory):
     """--plugin-dir works"""
     plugin_dir = 'contrib/plugins'
     node_factory.get_node(options={'plugin-dir': plugin_dir, 'greeting': 'Mars'})
+
+
+def test_plugin_disable(node_factory):
+    """--disable-plugin works"""
+    plugin_dir = 'contrib/plugins'
+    # We need plugin-dir before disable-plugin!
+    n = node_factory.get_node(options=OrderedDict([('plugin-dir', plugin_dir),
+                                                   ('disable-plugin',
+                                                    '{}/helloworld.py'
+                                                    .format(plugin_dir))]))
+    with pytest.raises(RpcError):
+        n.rpc.hello(name='Sun')
+
+    # Also works by basename.
+    n = node_factory.get_node(options=OrderedDict([('plugin-dir', plugin_dir),
+                                                   ('disable-plugin',
+                                                    'helloworld.py')]))
+    with pytest.raises(RpcError):
+        n.rpc.hello(name='Sun')