From cdf12d06bab6053c4e31d155a777fe2a2d90407d Mon Sep 17 00:00:00 2001
From: Simon Vrouwe <s_github@protonmail.com>
Date: Mon, 20 Jun 2022 10:52:37 +0300
Subject: [PATCH] lightningd: Make sure plugins don't register the same option
"name"
The extra entry in opt_table would never be called, leaving plugins
clueless why options keep defaulting.
Note that option registration outside startup does nothing.
Instead, dynamic plugins can use `plugin start [second_parameter]` to pass options.
---
lightningd/plugin.c | 29 ++++++++++++++++++++---------
1 file changed, 20 insertions(+), 9 deletions(-)
diff --git a/lightningd/plugin.c b/lightningd/plugin.c
index b8564817b..07bb6fa01 100644
--- a/lightningd/plugin.c
+++ b/lightningd/plugin.c
@@ -886,10 +886,24 @@ char *plugin_opt_set(const char *arg, struct plugin_opt *popt)
return NULL;
}
+/* Returns true if "name" was already registered and now overwritten. */
+static bool plugin_opt_register(struct plugin_opt *popt)
+{
+ bool was_registered = opt_unregister(popt->name);
+ if (streq(popt->type, "flag"))
+ opt_register_noarg(popt->name, plugin_opt_flag_set, popt,
+ popt->description);
+ else
+ opt_register_arg(popt->name, plugin_opt_set, NULL, popt,
+ popt->description);
+
+ return was_registered;
+}
+
static void destroy_plugin_opt(struct plugin_opt *opt)
{
- if (!opt_unregister(opt->name))
- fatal("Could not unregister %s", opt->name);
+ /* does nothing when "name" registration replaced its double */
+ opt_unregister(opt->name);
list_del(&opt->list);
}
@@ -978,13 +992,10 @@ static const char *plugin_opt_add(struct plugin *plugin, const char *buffer,
list_add_tail(&plugin->plugin_opts, &popt->list);
- if (streq(popt->type, "flag"))
- opt_register_noarg(popt->name, plugin_opt_flag_set, popt,
- popt->description);
-
- else
- opt_register_arg(popt->name, plugin_opt_set, NULL, popt,
- popt->description);
+ /* Command line options are parsed only during ld's startup and each "name"
+ * only once. Always registers to satisfy destructor */
+ if (plugin_opt_register(popt) && plugin->plugins->startup)
+ fatal("error starting plugin '%s': option name '%s' is already taken", plugin->cmd, popt->name);
tal_add_destructor(popt, destroy_plugin_opt);
return NULL;