From 1b32cc1c731675a36e9926f4fbed1fa0b6b3c65d Mon Sep 17 00:00:00 2001
From: Christian Decker <decker.christian@gmail.com>
Date: Wed, 8 Apr 2020 20:51:27 +0200
Subject: [PATCH] wire: Add a function to serialize a raw set of TLV fields

The generated wrappers will ignore the raw fields and will only consider the
shortcut fields. This function takes the raw fields and serializes them
instead.
---
 plugins/Makefile |  2 +-
 wire/tlvstream.c | 21 +++++++++++++++++++++
 wire/tlvstream.h |  3 +++
 3 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 wire/tlvstream.c

diff --git a/plugins/Makefile b/plugins/Makefile
index fce5bfd3e..b3cb29d4d 100644
--- a/plugins/Makefile
+++ b/plugins/Makefile
@@ -59,7 +59,7 @@ plugins/fundchannel: common/addr.o $(PLUGIN_FUNDCHANNEL_OBJS) $(PLUGIN_LIB_OBJS)
 
 plugins/bcli: bitcoin/chainparams.o $(PLUGIN_BCLI_OBJS) $(PLUGIN_LIB_OBJS) $(PLUGIN_COMMON_OBJS) $(JSMN_OBJS) $(CCAN_OBJS)
 
-plugins/keysend: bitcoin/chainparams.o wire/gen_onion_wire.o $(PLUGIN_KEYSEND_OBJS) $(PLUGIN_LIB_OBJS) $(PLUGIN_COMMON_OBJS) $(JSMN_OBJS) $(CCAN_OBJS)
+plugins/keysend: bitcoin/chainparams.o wire/tlvstream.o wire/gen_onion_wire.o $(PLUGIN_KEYSEND_OBJS) $(PLUGIN_LIB_OBJS) $(PLUGIN_COMMON_OBJS) $(JSMN_OBJS) $(CCAN_OBJS)
 
 $(PLUGIN_PAY_OBJS) $(PLUGIN_AUTOCLEAN_OBJS) $(PLUGIN_FUNDCHANNEL_OBJS) $(PLUGIN_BCLI_OBJS) $(PLUGIN_LIB_OBJS): $(PLUGIN_LIB_HEADER)
 
diff --git a/wire/tlvstream.c b/wire/tlvstream.c
new file mode 100644
index 000000000..257b53f0c
--- /dev/null
+++ b/wire/tlvstream.c
@@ -0,0 +1,21 @@
+#include <wire/tlvstream.h>
+#include <wire/wire.h>
+
+void towire_tlvstream_raw(u8 **pptr, const struct tlv_field *fields)
+{
+	if (!fields)
+		return;
+
+	for (size_t i = 0; i < tal_count(fields); i++) {
+		const struct tlv_field *field = &fields[i];
+		/* BOLT #1:
+		 *
+		 * The sending node:
+		 ...
+		 *  - MUST minimally encode `type` and `length`.
+		 */
+		towire_bigsize(pptr, field->numtype);
+		towire_bigsize(pptr, field->length);
+		towire(pptr, field->value, field->length);
+	}
+}
diff --git a/wire/tlvstream.h b/wire/tlvstream.h
index 256feb5e8..5ec9939a7 100644
--- a/wire/tlvstream.h
+++ b/wire/tlvstream.h
@@ -34,4 +34,7 @@ void towire_tlvs(u8 **pptr,
 		 size_t num_types,
 		 const void *record);
 
+/* Given any tlvstream serialize the raw fields (untyped ones). */
+void towire_tlvstream_raw(u8 **pptr, const struct tlv_field *fields);
+
 #endif /* LIGHTNING_WIRE_TLVSTREAM_H */