wallet: add invoice features into db.

In a future version, we will use features to insist that payers
provide the secret.  In transition, we may have old invoices which
didn't insist on that, so we need to know this on a per-invoice basis.

Not sure if I got the right syntax for adding an empty blob though!

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

lightningd/invoice.c

@@ -502,6 +502,7 @@ static void gossipd_incoming_channels_reply(struct subd *gossipd,
 				   info->b11->expiry,
 				   b11enc,
 				   info->b11->description,
+				   info->b11->features,
 				   &info->payment_preimage,
 				   &info->b11->payment_hash)) {
 		was_pending(command_fail(info->cmd, INVOICE_LABEL_ALREADY_EXISTS,

lightningd/test/run-invoice-select-inchan.c

@@ -510,6 +510,7 @@ bool wallet_invoice_create(struct wallet *wallet UNNEEDED,
 			   u64 expiry UNNEEDED,
 			   const char *b11enc UNNEEDED,
 			   const char *description UNNEEDED,
+			   const u8 *features UNNEEDED,
 			   const struct preimage *r UNNEEDED,
 			   const struct sha256 *rhash UNNEEDED)
 { fprintf(stderr, "wallet_invoice_create called!\n"); abort(); }

wallet/db.c

@@ -480,6 +480,7 @@ static struct migration dbmigrations[] = {
     /* See https://github.com/ElementsProject/lightning/issues/3189 */
     {SQL("UPDATE forwarded_payments SET received_time=0 WHERE received_time IS NULL;"),
 	 NULL},
+    {SQL("ALTER TABLE invoices ADD COLUMN features BLOB DEFAULT '';"), NULL},
 };
 
 /* Leak tracking. */

wallet/invoices.c

@@ -116,6 +116,9 @@ static struct invoice_details *wallet_stmt2invoice_details(const tal_t *ctx,
 	else
 		dtl->description = NULL;
 
+	dtl->features = tal_dup_arr(dtl, u8,
+				    db_column_blob(stmt, 11),
+				    db_column_bytes(stmt, 11), 0);
 	return dtl;
 }
 
@@ -253,6 +256,7 @@ bool invoices_create(struct invoices *invoices,
 		     u64 expiry,
 		     const char *b11enc,
 		     const char *description,
+		     const u8 *features,
 		     const struct preimage *r,
 		     const struct sha256 *rhash)
 {
@@ -279,11 +283,11 @@ bool invoices_create(struct invoices *invoices,
 		"            ( payment_hash, payment_key, state"
 		"            , msatoshi, label, expiry_time"
 		"            , pay_index, msatoshi_received"
-		"            , paid_timestamp, bolt11, description)"
+		"            , paid_timestamp, bolt11, description, features)"
 		"     VALUES ( ?, ?, ?"
 		"            , ?, ?, ?"
 		"            , NULL, NULL"
-		"            , NULL, ?, ?);"));
+		"            , NULL, ?, ?, ?);"));
 
 	db_bind_sha256(stmt, 0, rhash);
 	db_bind_preimage(stmt, 1, r);
@@ -296,6 +300,7 @@ bool invoices_create(struct invoices *invoices,
 	db_bind_u64(stmt, 5, expiry_time);
 	db_bind_text(stmt, 6, b11enc);
 	db_bind_text(stmt, 7, description);
+	db_bind_blob(stmt, 8, features, tal_bytelen(features));
 
 	db_exec_prepared_v2(stmt);
 
@@ -435,6 +440,7 @@ bool invoices_iterate(struct invoices *invoices,
 						       ", paid_timestamp"
 						       ", bolt11"
 						       ", description"
+						       ", features"
 						       " FROM invoices;"));
 		db_query_prepared(stmt);
 		it->p = stmt;
@@ -622,6 +628,7 @@ const struct invoice_details *invoices_get_details(const tal_t *ctx,
 					       ", paid_timestamp"
 					       ", bolt11"
 					       ", description"
+					       ", features"
 					       " FROM invoices"
 					       " WHERE id = ?;"));
 	db_bind_u64(stmt, 0, invoice.id);

wallet/invoices.h

@@ -50,6 +50,7 @@ bool invoices_create(struct invoices *invoices,
 		     u64 expiry,
 		     const char *b11enc,
 		     const char *description,
+		     const u8 *features,
 		     const struct preimage *r,
 		     const struct sha256 *rhash);
 

wallet/test/run-wallet.c

@@ -138,6 +138,7 @@ bool invoices_create(struct invoices *invoices UNNEEDED,
 		     u64 expiry UNNEEDED,
 		     const char *b11enc UNNEEDED,
 		     const char *description UNNEEDED,
+		     const u8 *features UNNEEDED,
 		     const struct preimage *r UNNEEDED,
 		     const struct sha256 *rhash UNNEEDED)
 { fprintf(stderr, "invoices_create called!\n"); abort(); }

wallet/wallet.c

@@ -1931,10 +1931,11 @@ bool wallet_invoice_create(struct wallet *wallet,
 			   u64 expiry,
 			   const char *b11enc,
 			   const char *description,
+			   const u8 *features,
 			   const struct preimage *r,
 			   const struct sha256 *rhash)
 {
-	return invoices_create(wallet->invoices, pinvoice, msat, label, expiry, b11enc, description, r, rhash);
+	return invoices_create(wallet->invoices, pinvoice, msat, label, expiry, b11enc, description, features, r, rhash);
 }
 bool wallet_invoice_find_by_label(struct wallet *wallet,
 				  struct invoice *pinvoice,

wallet/wallet.h

@@ -673,6 +673,8 @@ struct invoice_details {
 
 	/* The description of the payment. */
 	char *description;
+	/* The features, if any (tal_arr) */
+	u8 *features;
 };
 
 /* An object that handles iteration over the set of invoices */
@@ -713,6 +715,7 @@ bool wallet_invoice_create(struct wallet *wallet,
 			   u64 expiry,
 			   const char *b11enc,
 			   const char *description,
+			   const u8 *features,
 			   const struct preimage *r,
 			   const struct sha256 *rhash);