fuzz: target for update_fee

Fuzz the decoding and encoding of update_fee.

tests/fuzz/fuzz-wire-update_fee.c

@@ -0,0 +1,36 @@
+#include "config.h"
+#include <common/channel_id.h>
+#include <tests/fuzz/libfuzz.h>
+#include <tests/fuzz/wire.h>
+#include <wire/peer_wire.h>
+
+struct update_fee {
+	struct channel_id channel_id;
+	u32 feerate_per_kw;
+};
+
+static void *encode(const tal_t *ctx, const struct update_fee *s)
+{
+	return towire_update_fee(ctx, &s->channel_id, s->feerate_per_kw);
+}
+
+static struct update_fee *decode(const tal_t *ctx, const void *p)
+{
+	struct update_fee *s = tal(ctx, struct update_fee);
+
+	if (fromwire_update_fee(p, &s->channel_id, &s->feerate_per_kw))
+		return s;
+	return tal_free(s);
+}
+
+static bool equal(const struct update_fee *x, const struct update_fee *y)
+{
+	if (!channel_id_eq(&x->channel_id, &y->channel_id))
+		return false;
+	return x->feerate_per_kw == y->feerate_per_kw;
+}
+
+void run(const u8 *data, size_t size)
+{
+	test_decode_encode(data, size, WIRE_UPDATE_FEE, struct update_fee);
+}