fuzz: target for channel_update

Fuzz the decoding and encoding of channel_update.

tests/fuzz/fuzz-wire-channel_update.c

@@ -0,0 +1,52 @@
+#include "config.h"
+#include <tests/fuzz/libfuzz.h>
+#include <tests/fuzz/wire.h>
+#include <wire/peer_wire.h>
+
+struct channel_update {
+	secp256k1_ecdsa_signature signature;
+	struct bitcoin_blkid chain_hash;
+	struct short_channel_id short_channel_id;
+	u32 timestamp;
+	u8 message_flags;
+	u8 channel_flags;
+	u16 cltv_expiry_delta;
+	struct amount_msat htlc_minimum_msat;
+	u32 fee_base_msat;
+	u32 fee_proportional_millionths;
+	struct amount_msat htlc_maximum_msat;
+};
+
+static void *encode(const tal_t *ctx, const struct channel_update *s)
+{
+	return towire_channel_update(
+	    ctx, &s->signature, &s->chain_hash, &s->short_channel_id,
+	    s->timestamp, s->message_flags, s->channel_flags,
+	    s->cltv_expiry_delta, s->htlc_minimum_msat, s->fee_base_msat,
+	    s->fee_proportional_millionths, s->htlc_maximum_msat);
+}
+
+static struct channel_update *decode(const tal_t *ctx, const void *p)
+{
+	struct channel_update *s = tal(ctx, struct channel_update);
+
+	if (fromwire_channel_update(
+		p, &s->signature, &s->chain_hash, &s->short_channel_id,
+		&s->timestamp, &s->message_flags, &s->channel_flags,
+		&s->cltv_expiry_delta, &s->htlc_minimum_msat, &s->fee_base_msat,
+		&s->fee_proportional_millionths, &s->htlc_maximum_msat))
+		return s;
+	return tal_free(s);
+}
+
+static bool equal(const struct channel_update *x,
+		  const struct channel_update *y)
+{
+	return memcmp(x, y, sizeof(*x)) == 0;
+}
+
+void run(const u8 *data, size_t size)
+{
+	test_decode_encode(data, size, WIRE_CHANNEL_UPDATE,
+			   struct channel_update);
+}