From 85c9179f77b25f4b859a846619a6c3729da9b973 Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Mon, 16 Feb 2026 17:34:33 +1030
Subject: [PATCH] askrene: expose additional_costs htable so child can access
 it.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 plugins/askrene/Makefile                 |  2 +-
 plugins/askrene/askrene.c                | 26 +------------------
 plugins/askrene/child/additional_costs.h | 32 ++++++++++++++++++++++++
 3 files changed, 34 insertions(+), 26 deletions(-)
 create mode 100644 plugins/askrene/child/additional_costs.h

diff --git a/plugins/askrene/Makefile b/plugins/askrene/Makefile
index fd8e9f516..d870b0a5b 100644
--- a/plugins/askrene/Makefile
+++ b/plugins/askrene/Makefile
@@ -17,7 +17,7 @@ PLUGIN_ASKRENE_CHILD_SRC := \
 	plugins/askrene/child/child_log.c \
 
 PLUGIN_ASKRENE_SRC := $(PLUGIN_ASKRENE_PARENT_SRC) $(PLUGIN_ASKRENE_CHILD_SRC)
-PLUGIN_ASKRENE_HEADER := $(PLUGIN_ASKRENE_SRC:.c=.h)
+PLUGIN_ASKRENE_HEADER := $(PLUGIN_ASKRENE_SRC:.c=.h) plugins/askrene/child/additional_costs.h
 
 PLUGIN_ASKRENE_OBJS := $(PLUGIN_ASKRENE_SRC:.c=.o)
 
diff --git a/plugins/askrene/askrene.c b/plugins/askrene/askrene.c
index b1384299c..ef6d3a712 100644
--- a/plugins/askrene/askrene.c
+++ b/plugins/askrene/askrene.c
@@ -22,6 +22,7 @@
 #include <inttypes.h>
 #include <math.h>
 #include <plugins/askrene/askrene.h>
+#include <plugins/askrene/child/additional_costs.h>
 #include <plugins/askrene/child/child_log.h>
 #include <plugins/askrene/child/entry.h>
 #include <plugins/askrene/layer.h>
@@ -29,31 +30,6 @@
 #include <sys/wait.h>
 #include <wire/wire_sync.h>
 
-/* "spendable" for a channel assumes a single HTLC: for additional HTLCs,
- * the need to pay for fees (if we're the owner) reduces it */
-struct per_htlc_cost {
-	struct short_channel_id_dir scidd;
-	struct amount_msat per_htlc_cost;
-};
-
-static const struct short_channel_id_dir *
-per_htlc_cost_key(const struct per_htlc_cost *phc)
-{
-	return &phc->scidd;
-}
-
-static inline bool per_htlc_cost_eq_key(const struct per_htlc_cost *phc,
-					const struct short_channel_id_dir *scidd)
-{
-	return short_channel_id_dir_eq(scidd, &phc->scidd);
-}
-
-HTABLE_DEFINE_NODUPS_TYPE(struct per_htlc_cost,
-			  per_htlc_cost_key,
-			  hash_scidd,
-			  per_htlc_cost_eq_key,
-			  additional_cost_htable);
-
 static bool have_layer(const char **layers, const char *name)
 {
 	for (size_t i = 0; i < tal_count(layers); i++) {
diff --git a/plugins/askrene/child/additional_costs.h b/plugins/askrene/child/additional_costs.h
new file mode 100644
index 000000000..44eb0971f
--- /dev/null
+++ b/plugins/askrene/child/additional_costs.h
@@ -0,0 +1,32 @@
+#ifndef LIGHTNING_PLUGINS_ASKRENE_CHILD_ADDITIONAL_COSTS_H
+#define LIGHTNING_PLUGINS_ASKRENE_CHILD_ADDITIONAL_COSTS_H
+#include "config.h"
+#include <ccan/htable/htable_type.h>
+#include <ccan/tal/tal.h>
+
+/* "spendable" for a channel assumes a single HTLC: for additional HTLCs,
+ * the need to pay for fees (if we're the owner) reduces it */
+struct per_htlc_cost {
+	struct short_channel_id_dir scidd;
+	struct amount_msat per_htlc_cost;
+};
+
+static inline const struct short_channel_id_dir *
+per_htlc_cost_key(const struct per_htlc_cost *phc)
+{
+	return &phc->scidd;
+}
+
+static inline bool per_htlc_cost_eq_key(const struct per_htlc_cost *phc,
+					const struct short_channel_id_dir *scidd)
+{
+	return short_channel_id_dir_eq(scidd, &phc->scidd);
+}
+
+HTABLE_DEFINE_NODUPS_TYPE(struct per_htlc_cost,
+			  per_htlc_cost_key,
+			  hash_scidd,
+			  per_htlc_cost_eq_key,
+			  additional_cost_htable);
+
+#endif /* LIGHTNING_PLUGINS_ASKRENE_CHILD_ADDITIONAL_COSTS_H */