Plugins: Add recover plugin which'd identify if we've lost some state…

… and try to recover the node by entering mode.

plugins/.gitignore

@@ -15,3 +15,4 @@ chanbackup
 commando
 sql
 cln-renepay
+recover

plugins/Makefile

@@ -57,6 +57,9 @@ PLUGIN_SPENDER_HEADER :=			\
 	plugins/spender/openchannel.h
 PLUGIN_SPENDER_OBJS := $(PLUGIN_SPENDER_SRC:.c=.o)
 
+PLUGIN_RECOVER_SRC := plugins/recover.c
+PLUGIN_RECOVER_OBJS := $(PLUGIN_RECOVER_SRC:.c=.o)
+
 PLUGIN_FUNDER_SRC :=				\
 	plugins/funder.c			\
 	plugins/funder_policy.c
@@ -78,7 +81,8 @@ PLUGIN_ALL_SRC :=				\
 	$(PLUGIN_OFFERS_SRC)			\
 	$(PLUGIN_PAY_LIB_SRC)			\
 	$(PLUGIN_PAY_SRC)			\
-	$(PLUGIN_SPENDER_SRC)
+	$(PLUGIN_SPENDER_SRC)			\
+	$(PLUGIN_RECOVER_SRC)
 
 PLUGIN_ALL_HEADER :=				\
 	$(PLUGIN_PAY_HEADER)			\
@@ -99,6 +103,7 @@ C_PLUGINS :=					\
 	plugins/keysend				\
 	plugins/offers				\
 	plugins/pay				\
+	plugins/recover				\
 	plugins/txprepare			\
 	plugins/cln-renepay			\
 	plugins/spenderp
@@ -216,6 +221,8 @@ plugins/fetchinvoice: $(PLUGIN_FETCHINVOICE_OBJS) $(PLUGIN_LIB_OBJS) $(PLUGIN_CO
 
 plugins/funder: bitcoin/psbt.o common/psbt_open.o $(PLUGIN_FUNDER_OBJS) $(PLUGIN_LIB_OBJS) $(PLUGIN_COMMON_OBJS) $(JSMN_OBJS)
 
+plugins/recover:  common/gossmap.o common/fp16.o $(PLUGIN_RECOVER_OBJS) $(PLUGIN_LIB_OBJS) $(PLUGIN_COMMON_OBJS) $(JSMN_OBJS)
+
 # This covers all the low-level list RPCs which return simple arrays
 SQL_LISTRPCS := listchannels listforwards listhtlcs listinvoices listnodes listoffers listpeers listpeerchannels listclosedchannels listtransactions listsendpays bkpr-listaccountevents bkpr-listincome
 SQL_LISTRPCS_SCHEMAS := $(foreach l,$(SQL_LISTRPCS),doc/schemas/$l.schema.json)

plugins/recover.c

@@ -0,0 +1,23 @@
+#include "config.h"
+#include <ccan/array_size/array_size.h>
+#include <common/features.h>
+#include <common/gossmap.h>
+#include <common/hsm_encryption.h>
+#include <common/json_param.h>
+#include <common/json_stream.h>
+#include <common/type_to_string.h>
+#include <errno.h>
+#include <plugins/libplugin.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[])
+{
+        setup_locale();
+
+	plugin_main(argv, init, PLUGIN_STATIC, true, NULL,
+		    NULL, 0,
+		    NULL, 0, NULL, 0,
+		    NULL, 0,  /* Notification topics we publish */
+		    NULL);
+}
+