From b6a1735929bf99f6619eea0d66fd57502ad0c2f9 Mon Sep 17 00:00:00 2001
From: Christian Decker <decker.christian@gmail.com>
Date: Wed, 19 Sep 2018 22:19:51 +0200
Subject: [PATCH] plugin: Basic scaffolding for the plugin subsystem

---
 lightningd/Makefile |  1 +
 lightningd/plugin.c | 35 +++++++++++++++++++++++++++++++++++
 lightningd/plugin.h | 38 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 74 insertions(+)
 create mode 100644 lightningd/plugin.c
 create mode 100644 lightningd/plugin.h

diff --git a/lightningd/Makefile b/lightningd/Makefile
index 8ff4cdd91..a3fdfa09d 100644
--- a/lightningd/Makefile
+++ b/lightningd/Makefile
@@ -78,6 +78,7 @@ LIGHTNINGD_SRC :=				\
 	lightningd/peer_control.c		\
 	lightningd/peer_htlcs.c			\
 	lightningd/ping.c			\
+	lightningd/plugin.c			\
 	lightningd/subd.c			\
 	lightningd/watch.c
 
diff --git a/lightningd/plugin.c b/lightningd/plugin.c
new file mode 100644
index 000000000..f7c8f95f2
--- /dev/null
+++ b/lightningd/plugin.c
@@ -0,0 +1,35 @@
+#include "lightningd/plugin.h"
+
+#include <ccan/list/list.h>
+#include <ccan/tal/str/str.h>
+
+struct plugin {
+	int stdin, stdout;
+	pid_t pid;
+	char *cmd;
+};
+
+struct plugins {
+	struct plugin **plugins;
+};
+
+struct plugins *plugins_new(const tal_t *ctx){
+	struct plugins *p;
+	p = tal(ctx, struct plugins);
+	p->plugins = tal_arr(p, struct plugin *, 0);
+	return p;
+}
+
+void plugin_register(struct plugins *plugins, const char* path TAKES)
+{
+	struct plugin *p;
+	size_t n = tal_count(plugins->plugins);
+	tal_resize(&plugins->plugins, n+1);
+	p = tal(plugins, struct plugin);
+	plugins->plugins[n] = p;
+	p->cmd = tal_strdup(p, path);
+}
+
+void plugins_init(struct plugins *plugins)
+{
+}
diff --git a/lightningd/plugin.h b/lightningd/plugin.h
new file mode 100644
index 000000000..60bf3da67
--- /dev/null
+++ b/lightningd/plugin.h
@@ -0,0 +1,38 @@
+#ifndef LIGHTNING_LIGHTNINGD_PLUGIN_H
+#define LIGHTNING_LIGHTNINGD_PLUGIN_H
+#include "config.h"
+#include <ccan/take/take.h>
+#include <ccan/tal/tal.h>
+
+/**
+ * A collection of plugins, and some associated information.
+ *
+ * Mainly used as root context for calls in the plugin subsystem.
+ */
+struct plugins;
+
+/**
+ * Create a new plugins context.
+ */
+struct plugins *plugins_new(const tal_t *ctx);
+
+/**
+ * Initialize the registered plugins.
+ *
+ * Initialization includes spinning up the plugins, reading their
+ * manifest, and registering the JSON-RPC passthrough and command line
+ * arguments. In order to read the getmanifest reply from the plugins
+ * we spin up our own io_loop that exits once all plugins have
+ * responded.
+ */
+void plugins_init(struct plugins *plugins);
+
+/**
+ * Register a plugin for initialization and execution.
+ *
+ * @param plugins: Plugin context
+ * @param path: The path of the executable for this plugin
+ */
+void plugin_register(struct plugins *plugins, const char* path TAKES);
+
+#endif /* LIGHTNING_LIGHTNINGD_PLUGIN_H */