fuzz: target for update_fulfill_htlc

Fuzz the decoding and encoding of update_fulfill_htlc.

tests/fuzz/fuzz-wire-update_fulfill_htlc.c

@@ -0,0 +1,38 @@
+#include "config.h"
+#include <tests/fuzz/libfuzz.h>
+#include <tests/fuzz/wire.h>
+#include <wire/peer_wire.h>
+
+struct update_fulfill_htlc {
+	struct channel_id channel_id;
+	u64 id;
+	struct preimage payment_preimage;
+};
+
+static void *encode(const tal_t *ctx, const struct update_fulfill_htlc *s)
+{
+	return towire_update_fulfill_htlc(ctx, &s->channel_id, s->id,
+					  &s->payment_preimage);
+}
+
+static struct update_fulfill_htlc *decode(const tal_t *ctx, const void *p)
+{
+	struct update_fulfill_htlc *s = tal(ctx, struct update_fulfill_htlc);
+
+	if (fromwire_update_fulfill_htlc(p, &s->channel_id, &s->id,
+					 &s->payment_preimage))
+		return s;
+	return tal_free(s);
+}
+
+static bool equal(const struct update_fulfill_htlc *x,
+		  const struct update_fulfill_htlc *y)
+{
+	return memcmp(x, y, sizeof(*x)) == 0;
+}
+
+void run(const u8 *data, size_t size)
+{
+	test_decode_encode(data, size, WIRE_UPDATE_FULFILL_HTLC,
+			   struct update_fulfill_htlc);
+}