decode: print unknown fields in bolt12 strings.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

doc/lightning-decode.7.md

@@ -60,6 +60,10 @@ If **type** is "bolt12 offer", and **valid** is *true*:
       - **seconds\_before** (u32): seconds prior to period start
       - **seconds\_after** (u32): seconds after to period start
       - **proportional\_amount** (boolean, optional): amount should be scaled if payed after period start (always *true*)
+  - **unknown\_offer\_tlvs** (array of objects, optional): Any extra fields we didn't know how to parse:
+    - **type** (u64): The type
+    - **length** (u64): The length
+    - **value** (hex): The value
   - the following warnings are possible:
     - **warning\_unknown\_offer\_currency**: The currency code is unknown (so no `currency_minor_unit`)
 
@@ -115,6 +119,10 @@ If **type** is "bolt12 invoice_request", and **valid** is *true*:
   - **invreq\_payer\_note** (string, optional): a note attached by the payer
   - **invreq\_recurrence\_counter** (u32, optional): which number request this is for the same invoice
   - **invreq\_recurrence\_start** (u32, optional): when we're requesting to start an invoice at a non-zero period
+  - **unknown\_invoice\_request\_tlvs** (array of objects, optional): Any extra fields we didn't know how to parse:
+    - **type** (u64): The type
+    - **length** (u64): The length
+    - **value** (hex): The value
   - the following warnings are possible:
     - **warning\_unknown\_offer\_currency**: The currency code is unknown (so no `currency_minor_unit`)
 
@@ -195,6 +203,10 @@ If **type** is "bolt12 invoice", and **valid** is *true*:
   - **invoice\_features** (hex, optional): the feature bits of the invoice
   - **invoice\_node\_id** (pubkey, optional): the id to pay (usually the same as offer_node_id)
   - **invoice\_recurrence\_basetime** (u64, optional): the UNIX timestamp to base the invoice periods on
+  - **unknown\_invoice\_tlvs** (array of objects, optional): Any extra fields we didn't know how to parse:
+    - **type** (u64): The type
+    - **length** (u64): The length
+    - **value** (hex): The value
   - the following warnings are possible:
     - **warning\_unknown\_offer\_currency**: The currency code is unknown (so no `currency_minor_unit`)
 
@@ -290,4 +302,4 @@ RESOURCES
 
 Main web site: <https://github.com/ElementsProject/lightning>
 
-[comment]: # ( SHA256STAMP:e5791741d8b466b2f080dcde3e5a7770ce3a820d0b7e5635e6b6cfd1f104c09d)
+[comment]: # ( SHA256STAMP:1d13c0e0619d05d8c49cf9fbed90f0baf260d59fd8c16bd283d3b211e8be9878)

doc/schemas/decode.schema.json

@@ -221,6 +221,33 @@
                 }
               }
             }
+          },
+          "unknown_offer_tlvs": {
+            "type": "array",
+            "description": "Any extra fields we didn't know how to parse",
+            "items": {
+              "type": "object",
+              "required": [
+                "type",
+                "length",
+                "value"
+              ],
+              "additionalProperties": false,
+              "properties": {
+                "type": {
+                  "type": "u64",
+                  "description": "The type"
+                },
+                "length": {
+                  "type": "u64",
+                  "description": "The length"
+                },
+                "value": {
+                  "type": "hex",
+                  "description": "The value"
+                }
+              }
+            }
           }
         }
       }
@@ -264,6 +291,7 @@
           "absolute_expiry": {},
           "paths": {},
           "quantity_max": {},
+          "unknown_offer_tlvs": {},
           "recurrence": {},
           "warning_missing_offer_node_id": {
             "type": "string",
@@ -530,6 +558,33 @@
           "signature": {
             "type": "bip340sig",
             "description": "BIP-340 signature of the `invreq_payer_id` on this invoice_request"
+          },
+          "unknown_invoice_request_tlvs": {
+            "type": "array",
+            "description": "Any extra fields we didn't know how to parse",
+            "items": {
+              "type": "object",
+              "required": [
+                "type",
+                "length",
+                "value"
+              ],
+              "additionalProperties": false,
+              "properties": {
+                "type": {
+                  "type": "u64",
+                  "description": "The type"
+                },
+                "length": {
+                  "type": "u64",
+                  "description": "The length"
+                },
+                "value": {
+                  "type": "hex",
+                  "description": "The value"
+                }
+              }
+            }
           }
         }
       }
@@ -984,6 +1039,33 @@
           "signature": {
             "type": "bip340sig",
             "description": "BIP-340 signature of the `offer_node_id` on this invoice"
+          },
+          "unknown_invoice_tlvs": {
+            "type": "array",
+            "description": "Any extra fields we didn't know how to parse",
+            "items": {
+              "type": "object",
+              "required": [
+                "type",
+                "length",
+                "value"
+              ],
+              "additionalProperties": false,
+              "properties": {
+                "type": {
+                  "type": "u64",
+                  "description": "The type"
+                },
+                "length": {
+                  "type": "u64",
+                  "description": "The length"
+                },
+                "value": {
+                  "type": "hex",
+                  "description": "The value"
+                }
+              }
+            }
           }
         }
       }

plugins/offers.c

@@ -432,6 +432,29 @@ static bool json_add_offer_fields(struct json_stream *js,
 	return valid;
 }
 
+static void json_add_extra_fields(struct json_stream *js,
+				  const char *fieldname,
+				  const struct tlv_field *fields)
+{
+	bool have_extra = false;
+
+	for (size_t i = 0; i < tal_count(fields); i++) {
+		if (fields[i].meta)
+			continue;
+		if (!have_extra) {
+			json_array_start(js, fieldname);
+			have_extra = true;
+		}
+		json_object_start(js, NULL);
+		json_add_u64(js, "type", fields[i].numtype);
+		json_add_u64(js, "length", fields[i].length);
+		json_add_hex(js, "value",
+			     fields[i].value, fields[i].length);
+	}
+	if (have_extra)
+		json_array_end(js);
+}
+
 static void json_add_offer(struct json_stream *js, const struct tlv_offer *offer)
 {
 	struct sha256 offer_id;
@@ -465,6 +488,7 @@ static void json_add_offer(struct json_stream *js, const struct tlv_offer *offer
 				"offers without a node_id are invalid");
 		valid = false;
 	}
+	json_add_extra_fields(js, "unknown_offer_tlvs", offer->fields);
 	json_add_bool(js, "valid", valid);
 }
 
@@ -665,6 +689,7 @@ static void json_add_invoice_request(struct json_stream *js,
 		valid = false;
 	}
 
+	json_add_extra_fields(js, "unknown_invoice_request_tlvs", invreq->fields);
 	json_add_bool(js, "valid", valid);
 }
 
@@ -815,6 +840,7 @@ static void json_add_b12_invoice(struct json_stream *js,
 	/* invoice_decode checked this */
 	json_add_bip340sig(js, "signature", invoice->signature);
 
+	json_add_extra_fields(js, "unknown_invoice_tlvs", invoice->fields);
 	json_add_bool(js, "valid", valid);
 }