lightningd: add --plugin-dir option to load directory full of plugins.

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

lightningd/options.c

@@ -293,6 +293,11 @@ static char *opt_add_plugin(const char *arg, struct lightningd *ld)
 	return NULL;
 }
 
+static char *opt_add_plugin_dir(const char *arg, struct lightningd *ld)
+{
+	return add_plugin_dir(ld->plugins, arg);
+}
+
 static void config_register_opts(struct lightningd *ld)
 {
 	opt_register_early_arg("--conf=<file>", opt_set_talstr, NULL,
@@ -302,7 +307,10 @@ static void config_register_opts(struct lightningd *ld)
 	/* Register plugins as an early argc, 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.");
+			       "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_noarg("--daemon", opt_set_bool, &ld->daemon,
 			 "Run in the background, suppress stdout/stderr");
@@ -989,6 +997,9 @@ 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) {
+			/* FIXME: We actually treat it as if they specified
+			 * --plugin for each one, so ignore this */
 #if DEVELOPER
 		} else if (strstarts(name, "dev-")) {
 			/* Ignore dev settings */

lightningd/plugin.c

@@ -5,13 +5,18 @@
 #include <ccan/list/list.h>
 #include <ccan/opt/opt.h>
 #include <ccan/pipecmd/pipecmd.h>
+#include <ccan/tal/path/path.h>
 #include <ccan/tal/str/str.h>
+#include <ccan/utf8/utf8.h>
 #include <common/memleak.h>
+#include <dirent.h>
 #include <errno.h>
 #include <lightningd/json.h>
 #include <lightningd/jsonrpc_errors.h>
 #include <lightningd/lightningd.h>
 #include <signal.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 #include <unistd.h>
 
 struct plugin {
@@ -22,6 +27,7 @@ struct plugin {
 	struct io_conn *stdin_conn, *stdout_conn;
 	bool stop;
 	struct plugins *plugins;
+	const char **plugin_path;
 
 	/* Stuff we read */
 	char *buffer;
@@ -602,6 +608,56 @@ static void plugin_manifest_cb(const struct plugin_request *req, struct plugin *
 		plugin_kill(plugin, "Failed to register options or methods");
 }
 
+/* If this is a valid plugin return full path name, otherwise NULL */
+static const char *plugin_fullpath(const tal_t *ctx, const char *dir,
+				   const char *basename)
+{
+	struct stat st;
+	const char *fullname;
+	struct utf8_state utf8 = UTF8_STATE_INIT;
+
+	for (size_t i = 0; basename[i]; i++) {
+		if (!utf8_decode(&utf8, basename[i]))
+			continue;
+		/* Not valid UTF8?  Let's not go there... */
+		if (errno != 0)
+			return NULL;
+		if (utf8.used_len != 1)
+			continue;
+		if (!cispunct(utf8.c))
+			continue;
+		if (utf8.c != '-' && utf8.c != '_' && utf8.c != '.')
+			return NULL;
+	}
+
+	fullname = path_join(ctx, dir, basename);
+	if (stat(fullname, &st) != 0)
+		return tal_free(fullname);
+	if (!(st.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)))
+		return tal_free(fullname);
+	return fullname;
+}
+
+char *add_plugin_dir(struct plugins *plugins, const char *dir)
+{
+	struct dirent *di;
+	DIR *d = opendir(dir);
+	if (!d)
+		return tal_fmt("Failed to open plugin-dir %s: %s",
+			       dir, strerror(errno));
+
+	while ((di = readdir(d)) != NULL) {
+		const char *fullpath;
+
+		if (streq(di->d_name, ".") || streq(di->d_name, ".."))
+			continue;
+		fullpath = plugin_fullpath(NULL, dir, di->d_name);
+		if (fullpath)
+			plugin_register(plugins, take(fullpath));
+	}
+	return NULL;
+}
+
 void plugins_init(struct plugins *plugins)
 {
 	struct plugin *p;

lightningd/plugin.h

@@ -56,4 +56,10 @@ void plugins_config(struct plugins *plugins);
 void json_add_opt_plugins(struct json_stream *response,
 			  const struct plugins *plugins);
 
+
+/**
+ * Add a directory to the plugin path to automatically load plugins.
+ */
+char *add_plugin_dir(struct plugins *plugins, const char *dir);
+
 #endif /* LIGHTNING_LIGHTNINGD_PLUGIN_H */

tests/test_plugin.py

@@ -51,3 +51,9 @@ def test_rpc_passthrough(node_factory):
     assert(greet == "Hello Sun")
     with pytest.raises(RpcError):
         n.rpc.fail()
+
+
+def test_plugin_dir(node_factory):
+    """--plugin-dir works"""
+    plugin_dir = 'contrib/plugins'
+    node_factory.get_node(options={'plugin-dir': plugin_dir, 'greeting': 'Mars'})