lightningd: remove support for legacy onion format.

As per proposal in lightning/bolts#962

Signed-off-by: Rusty Russell <[email protected]>
Changelog-Removed: protocol: support for legacy onion format removed, since everyone supports the new one.

common/onion.h

@@ -6,14 +6,7 @@
 
 struct route_step;
 
-enum onion_payload_type {
-	ONION_V0_PAYLOAD = 0,
-	ONION_TLV_PAYLOAD = 1,
-};
-
 struct onion_payload {
-	enum onion_payload_type type;
-
 	struct amount_msat amt_to_forward;
 	u32 outgoing_cltv;
 	struct amount_msat *total_msat;
@@ -29,7 +22,6 @@ struct onion_payload {
 };
 
 u8 *onion_nonfinal_hop(const tal_t *ctx,
-		       bool use_tlv,
 		       const struct short_channel_id *scid,
 		       struct amount_msat forward,
 		       u32 outgoing_cltv,
@@ -38,7 +30,6 @@ u8 *onion_nonfinal_hop(const tal_t *ctx,
 
 /* Note that this can fail if we supply payment_secret and !use_tlv! */
 u8 *onion_final_hop(const tal_t *ctx,
-		    bool use_tlv,
 		    struct amount_msat forward,
 		    u32 outgoing_cltv,
 		    struct amount_msat total_msat,
@@ -52,16 +43,14 @@ u8 *onion_final_hop(const tal_t *ctx,
  * @len: length of @raw_payload in bytes.
  * @has_realm: used for HTLCs, where first byte 0 is magical.
  * @valid: set to true if it is valid, false otherwise.
- * @type: if non-NULL, set to type of payload if *@valid is true.
  *
  * If @valid is set, there is room for the HMAC immediately following,
  * as the return value is <= ROUTING_INFO_SIZE - HMAC_SIZE.  Otherwise,
  * the return value is @len (i.e. the entire payload).
  */
 size_t onion_payload_length(const u8 *raw_payload, size_t len,
 			    bool has_realm,
-			    bool *valid,
-			    enum onion_payload_type *type);
+			    bool *valid);
 
 /**
  * onion_decode: decode payload from a decrypted onion.

common/route.c

@@ -101,12 +101,6 @@ static bool dijkstra_to_hops(struct route_hop **hops,
 	/* Find other end of channel. */
 	next = gossmap_nth_node(gossmap, c, !(*hops)[num_hops].direction);
 	gossmap_node_get_id(gossmap, next, &(*hops)[num_hops].node_id);
-	/* If we don't have a node_announcement, we *assume* modern */
-	if (next->nann_off == 0
-	    || gossmap_node_get_feature(gossmap, next, OPT_VAR_ONION) != -1)
-		(*hops)[num_hops].style = ROUTE_HOP_TLV;
-	else
-		(*hops)[num_hops].style = ROUTE_HOP_LEGACY;
 
 	/* These are (ab)used by others. */
 	(*hops)[num_hops].blinding = NULL;

common/route.h

@@ -11,11 +11,6 @@ struct gossmap;
 struct gossmap_chan;
 struct gossmap_node;
 
-enum route_hop_style {
-	ROUTE_HOP_LEGACY = 1,
-	ROUTE_HOP_TLV = 2,
-};
-
 /**
  * struct route_hop: a hop in a route.
  *
@@ -26,7 +21,6 @@ enum route_hop_style {
  * @delay: total cltv delay at this hop.
  * @blinding: blinding key for this hop (if any)
  * @enctlv: encrypted TLV for this hop (if any)
- * @style: onion encoding style for this hop.
  */
 struct route_hop {
 	struct short_channel_id scid;
@@ -36,7 +30,6 @@ struct route_hop {
 	u32 delay;
 	struct pubkey *blinding;
 	u8 *enctlv;
-	enum route_hop_style style;
 };
 
 /* Can c carry amount in dir? */

common/sphinx.c

@@ -627,7 +627,7 @@ struct route_step *process_onionpacket(
 	payload_size = onion_payload_length(paddedheader,
 					    tal_bytelen(msg->routinginfo),
 					    has_realm,
-					    &valid, NULL);
+					    &valid);
 
 	/* Can't decode?  Treat it as terminal. */
 	if (!valid) {

common/test/run-sphinx-xor_cipher_stream.c

@@ -91,8 +91,7 @@ struct onionreply *new_onionreply(const tal_t *ctx UNNEEDED, const u8 *contents
 /* Generated stub for onion_payload_length */
 size_t onion_payload_length(const u8 *raw_payload UNNEEDED, size_t len UNNEEDED,
 			    bool has_realm UNNEEDED,
-			    bool *valid UNNEEDED,
-			    enum onion_payload_type *type UNNEEDED)
+			    bool *valid UNNEEDED)
 { fprintf(stderr, "onion_payload_length called!\n"); abort(); }
 /* Generated stub for pubkey_from_node_id */
 bool pubkey_from_node_id(struct pubkey *key UNNEEDED, const struct node_id *id UNNEEDED)

devtools/onion.c

@@ -71,22 +71,19 @@ static void do_generate(int argc, char **argv,
 		} else {
 			struct short_channel_id scid;
 			struct amount_msat amt;
-			bool use_tlv = streq(argv[1 + i] + klen, "/tlv");
 
 			/* FIXME: support secret and and total_msat */
 			memset(&scid, i, sizeof(scid));
 			amt = amount_msat(i);
 			if (i == num_hops - 1)
 				sphinx_add_hop(sp, &path[i],
 					       take(onion_final_hop(NULL,
-								    use_tlv,
 								    amt, i, amt,
 								    NULL, NULL,
 								    NULL)));
 			else
 				sphinx_add_hop(sp, &path[i],
 					       take(onion_nonfinal_hop(NULL,
-								       use_tlv,
 								       &scid,
 								       amt, i,
 								       NULL,
@@ -273,7 +270,6 @@ static void runtest(const char *filename)
 	decodetok = json_get_member(buffer, toks, "decode");
 
 	json_for_each_arr(i, hop, decodetok) {
-		enum onion_payload_type type;
 		bool valid;
 
 		hexprivkey = json_strdup(ctx, buffer, hop);
@@ -284,9 +280,8 @@ static void runtest(const char *filename)
 			errx(1, "Error serializing message.");
 		onion_payload_length(step->raw_payload,
 				     tal_bytelen(step->raw_payload),
-				     true, &valid, &type);
+				     true, &valid);
 		assert(valid);
-		printf("  Type: %d\n", type);
 		printf("  Payload: %s\n", tal_hex(ctx, step->raw_payload));
 		printf("  Next onion: %s\n", tal_hex(ctx, serialized));
 		printf("  Next HMAC: %s\n",

lightningd/invoice.c

@@ -175,14 +175,12 @@ static void invoice_payment_add_tlvs(struct json_stream *stream,
 				     struct htlc_set *hset)
 {
 	struct htlc_in *hin;
-	struct tlv_tlv_payload *tlvs;
+	const struct tlv_tlv_payload *tlvs;
 	assert(tal_count(hset->htlcs) > 0);
 
 	/* Pick the first HTLC as representative for the entire set. */
 	hin = hset->htlcs[0];
 
-	if (hin->payload->type != ONION_TLV_PAYLOAD)
-		return;
 	tlvs = hin->payload->tlv;
 
 	json_array_start(stream, "extratlvs");

lightningd/pay.c

@@ -751,18 +751,6 @@ static struct command_result *wait_payment(struct lightningd *ld,
 	abort();
 }
 
-static bool should_use_tlv(enum route_hop_style style)
-{
-	switch (style) {
-	case ROUTE_HOP_TLV:
-		return true;
-		/* Otherwise fall thru */
-	case ROUTE_HOP_LEGACY:
-		return false;
-	}
-	abort();
-}
-
 /* Returns failmsg on failure, tallocated off ctx */
 static const u8 *send_onion(const tal_t *ctx, struct lightningd *ld,
 			    const struct onionpacket *packet,
@@ -1126,7 +1114,7 @@ send_payment(struct lightningd *ld,
 	struct short_channel_id *channels;
 	struct sphinx_path *path;
 	struct pubkey pubkey;
-	bool final_tlv, ret;
+	bool ret;
 	u8 *onion;
 
 	/* Expiry for HTLCs is absolute.  And add one to give some margin. */
@@ -1144,7 +1132,6 @@ send_payment(struct lightningd *ld,
 
 		sphinx_add_hop(path, &pubkey,
 			       take(onion_nonfinal_hop(NULL,
-					should_use_tlv(route[i].style),
 					&route[i + 1].scid,
 					route[i + 1].amount,
 					base_expiry + route[i + 1].delay,
@@ -1157,25 +1144,15 @@ send_payment(struct lightningd *ld,
 	ret = pubkey_from_node_id(&pubkey, &ids[i]);
 	assert(ret);
 
-	final_tlv = should_use_tlv(route[i].style);
 	/* BOLT #4:
 	 * - Unless `node_announcement`, `init` message or the
 	 *   [BOLT #11](11-payment-encoding.md#tagged-fields) offers feature
 	 *   `var_onion_optin`:
 	 *    - MUST use the legacy payload format instead.
 	 */
-	/* In our case, we don't use it unless we also have a payment_secret;
-	 * everyone should support this eventually */
-	if (!final_tlv && payment_secret)
-		final_tlv = true;
-
-	/* Parallel payments are invalid for legacy. */
-	if (partid && !final_tlv)
-		return command_fail(cmd, PAY_DESTINATION_PERM_FAIL,
-				    "Cannot do parallel payments to legacy node");
+	/* FIXME: This requirement is now obsolete, and we should remove it! */
 
 	onion = onion_final_hop(cmd,
-				final_tlv,
 				route[i].amount,
 				base_expiry + route[i].delay,
 				total_msat, route[i].blinding, route[i].enctlv,
@@ -1326,23 +1303,19 @@ AUTODATA(json_command, &sendonion_command);
 JSON-RPC sendpay interface
 -----------------------------------------------------------------------------*/
 
+/* FIXME: We accept his parameter for now, will deprecate eventually */
 static struct command_result *param_route_hop_style(struct command *cmd,
 						    const char *name,
 						    const char *buffer,
 						    const jsmntok_t *tok,
-						    enum route_hop_style **style)
+						    int **unused)
 {
-	*style = tal(cmd, enum route_hop_style);
-	if (json_tok_streq(buffer, tok, "legacy")) {
-		**style = ROUTE_HOP_LEGACY;
-		return NULL;
-	} else if (json_tok_streq(buffer, tok, "tlv")) {
-		**style = ROUTE_HOP_TLV;
+	if (json_tok_streq(buffer, tok, "tlv")) {
 		return NULL;
 	}
 
 	return command_fail_badparam(cmd, name, buffer, tok,
-			    "should be 'legacy' or 'tlv'");
+			    "should be 'tlv' ('legacy' not supported)");
 }
 
 static struct command_result *param_route_hops(struct command *cmd,
@@ -1366,7 +1339,7 @@ static struct command_result *param_route_hops(struct command *cmd,
 		unsigned *delay, *direction;
 		struct pubkey *blinding;
 		u8 *enctlv;
-		enum route_hop_style *style, default_style;
+		int *ignored;
 
 		if (!param(cmd, buffer, t,
 			   /* Only *one* of these is required */
@@ -1378,7 +1351,7 @@ static struct command_result *param_route_hops(struct command *cmd,
 			   p_opt("channel", param_short_channel_id, &channel),
 			   /* Allowed (getroute supplies it) but ignored */
 			   p_opt("direction", param_number, &direction),
-			   p_opt("style", param_route_hop_style, &style),
+			   p_opt("style", param_route_hop_style, &ignored),
 			   p_opt("blinding", param_pubkey, &blinding),
 			   p_opt("encrypted_recipient_data", param_bin_from_hex, &enctlv),
 			   NULL))
@@ -1405,21 +1378,12 @@ static struct command_result *param_route_hops(struct command *cmd,
 		if (!msat)
 			msat = amount_msat;
 
-		if (blinding || enctlv) {
-			if (style && *style == ROUTE_HOP_LEGACY)
-				return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-						    "%s[%zi]: Can't have blinding or enctlv with legacy", name, i);
-			default_style = ROUTE_HOP_TLV;
-		} else
-			default_style = ROUTE_HOP_LEGACY;
-
 		(*hops)[i].amount = *msat;
 		(*hops)[i].node_id = *id;
 		(*hops)[i].delay = *delay;
 		(*hops)[i].scid = *channel;
 		(*hops)[i].blinding = blinding;
 		(*hops)[i].enctlv = enctlv;
-		(*hops)[i].style = style ? *style : default_style;
 	}
 
 	return NULL;

lightningd/peer_htlcs.c

@@ -945,15 +945,7 @@ static void htlc_accepted_hook_serialize(struct htlc_accepted_hook_payload *p,
 
 	json_add_hex_talarr(s, "payload", rs->raw_payload);
 	if (p->payload) {
-		switch (p->payload->type) {
-		case ONION_V0_PAYLOAD:
-			json_add_string(s, "type", "legacy");
-			break;
-
-		case ONION_TLV_PAYLOAD:
-			json_add_string(s, "type", "tlv");
-			break;
-		}
+		json_add_string(s, "type", "tlv");
 
 		if (p->payload->forward_channel)
 			json_add_short_channel_id(s, "short_channel_id",

plugins/keysend.c

@@ -63,14 +63,7 @@ static void keysend_cb(struct keysend_data *d, struct payment *p) {
 	size_t hopcount;
 
 	/* On the root payment we perform the featurebit check. */
-	if (p->parent == NULL && p->step == PAYMENT_STEP_INITIALIZED) {
-		if (!payment_root(p)->destination_has_tlv)
-			return payment_fail(
-			    p,
-			    "Recipient %s does not support keysend payments "
-			    "(no TLV support)",
-			    node_id_to_hexstr(tmpctx, p->destination));
-	} else if (p->step == PAYMENT_STEP_FAILED) {
+	if (p->step == PAYMENT_STEP_FAILED) {
 		/* Now we can look at the error, and the failing node,
 		   and determine whether they didn't like our
 		   attempt. This is required since most nodes don't
@@ -184,7 +177,6 @@ static struct command_result *json_keysend(struct command *cmd, const char *buf,
 	p->json_buffer = tal_dup_talarr(p, const char, buf);
 	p->json_toks = params;
 	p->destination = tal_steal(p, destination);
-	p->destination_has_tlv = true;
 	p->payment_secret = NULL;
 	p->amount = *msat;
 	p->routes = tal_steal(p, hints);