fuzz: target for tx_init_rbf

Fuzz the decoding and encoding of tx_init_rbf.

tests/fuzz/fuzz-wire-tx_init_rbf.c

@@ -0,0 +1,48 @@
+#include "config.h"
+#include <assert.h>
+#include <ccan/mem/mem.h>
+#include <stdint.h>
+#include <tests/fuzz/libfuzz.h>
+#include <tests/fuzz/wire.h>
+#include <wire/peer_wire.h>
+
+struct tx_init_rbf {
+	struct channel_id channel_id;
+	u32 locktime;
+	u32 feerate;
+	struct tlv_tx_init_rbf_tlvs *tlvs;
+};
+
+static void *encode(const tal_t *ctx, const struct tx_init_rbf *s)
+{
+	return towire_tx_init_rbf(ctx, &s->channel_id, s->locktime, s->feerate,
+				  s->tlvs);
+}
+
+static struct tx_init_rbf *decode(const tal_t *ctx, const void *p)
+{
+	struct tx_init_rbf *s = tal(ctx, struct tx_init_rbf);
+
+	if (fromwire_tx_init_rbf(s, p, &s->channel_id, &s->locktime,
+				 &s->feerate, &s->tlvs))
+		return s;
+	return tal_free(s);
+}
+
+static bool equal(const struct tx_init_rbf *x, const struct tx_init_rbf *y)
+{
+	size_t upto_tlvs = (uintptr_t)&x->tlvs - (uintptr_t)x;
+	if (memcmp(x, y, upto_tlvs) != 0)
+		return false;
+
+	assert(x->tlvs && y->tlvs);
+	return memeq(x->tlvs->funding_output_contribution,
+		     tal_bytelen(x->tlvs->funding_output_contribution),
+		     y->tlvs->funding_output_contribution,
+		     tal_bytelen(y->tlvs->funding_output_contribution));
+}
+
+void run(const u8 *data, size_t size)
+{
+	test_decode_encode(data, size, WIRE_TX_INIT_RBF, struct tx_init_rbf);
+}