connectd: add network to init message

This implements lightning/bolts#682.

Changelog-Added: protocol: We now signal the network we are running on at init.

Author: darosior

connectd/peer_exchange_initmsg.c

@@ -27,6 +27,15 @@ struct peer {
 	u8 *msg;
 };
 
+static bool contains_common_chain(struct bitcoin_blkid *chains)
+{
+	for (size_t i = 0; i < tal_count(chains); i++) {
+		if (bitcoin_blkid_eq(&chains[0], &chainparams->genesis_blockhash))
+			return true;
+	}
+	return false;
+}
+
 /* Here in case we need to read another message. */
 static struct io_plan *read_init(struct io_conn *conn, struct peer *peer);
 
@@ -36,6 +45,7 @@ static struct io_plan *peer_init_received(struct io_conn *conn,
 	u8 *msg = cryptomsg_decrypt_body(tmpctx, &peer->cs, peer->msg);
 	u8 *globalfeatures, *features;
 	int unsup;
+	struct tlv_init_tlvs *tlvs = tlv_init_tlvs_new(msg);
 
 	if (!msg)
 		return io_close(conn);
@@ -51,13 +61,34 @@ static struct io_plan *peer_init_received(struct io_conn *conn,
 	if (unlikely(is_unknown_msg_discardable(msg)))
 		return read_init(conn, peer);
 
-	if (!fromwire_init(tmpctx, msg, &globalfeatures, &features)) {
+	if (!fromwire_init(tmpctx, msg, &globalfeatures, &features, tlvs)) {
 		status_peer_debug(&peer->id,
 				  "bad fromwire_init '%s', closing",
 				  tal_hex(tmpctx, msg));
 		return io_close(conn);
 	}
 
+	/* BOLT-ef7c97c02b6fa67a1df1af30b3843eb576100ebd #1:
+	 * The receiving node:
+	 * ...
+	 *  - upon receiving `networks` containing no common chains
+	 *    - MAY fail the connection.
+	 */
+	if (tlvs->networks) {
+		if (!tlvs->networks->chains) {
+			status_peer_debug(&peer->id,
+			                  "bad networks TLV in init '%s', closing",
+			                  tal_hex(tmpctx, msg));
+			return io_close(conn);
+		}
+		if (!contains_common_chain(tlvs->networks->chains)) {
+			status_peer_debug(&peer->id,
+			                  "No common chain with this peer '%s', closing",
+			                  tal_hex(tmpctx, msg));
+			return io_close(conn);
+		}
+	}
+
 	/* The globalfeatures field is now unused, but there was a
 	 * window where it was: combine the two. */
 	for (size_t i = 0; i < tal_bytelen(globalfeatures) * 8; i++) {
@@ -136,18 +167,27 @@ struct io_plan *peer_exchange_initmsg(struct io_conn *conn,
 	/* If conn is closed, forget peer */
 	struct peer *peer = tal(conn, struct peer);
 	struct io_plan *(*next)(struct io_conn *, struct peer *);
+	struct tlv_init_tlvs *tlvs;
 
 	peer->daemon = daemon;
 	peer->id = *id;
 	peer->addr = *addr;
 	peer->cs = *cs;
 
-	/* BOLT #1:
+	/* BOLT-ef7c97c02b6fa67a1df1af30b3843eb576100ebd #1:
 	 *
 	 * The sending node:
 	 *   - MUST send `init` as the first Lightning message for any
 	 *     connection.
+	 *  ...
+	 *   - SHOULD set `networks` to all chains it will gossip or open
+	 *     channels for.
 	 */
+	tlvs = tlv_init_tlvs_new(tmpctx);
+	tlvs->networks = tal(tlvs, struct tlv_init_tlvs_networks);
+	tlvs->networks->chains = tal_arr(tlvs->networks, struct bitcoin_blkid, 1);
+	tlvs->networks->chains[0] = chainparams->genesis_blockhash;
+
 	/* Initially, there were two sets of feature bits: global and local.
 	 * Local affected peer nodes only, global affected everyone.  Both were
 	 * sent in the `init` message, but node_announcement only advertized
@@ -167,7 +207,8 @@ struct io_plan *peer_exchange_initmsg(struct io_conn *conn,
 	 * from now on they'll all go in initfeatures. */
 	peer->msg = towire_init(NULL,
 				get_offered_globalinitfeatures(tmpctx),
-				get_offered_initfeatures(tmpctx));
+				get_offered_initfeatures(tmpctx),
+				tlvs);
 	status_peer_io(LOG_IO_OUT, &peer->id, peer->msg);
 	peer->msg = cryptomsg_encrypt_msg(peer, &peer->cs, take(peer->msg));
 

devtools/gossipwith.c

@@ -137,7 +137,7 @@ static struct io_plan *handshake_success(struct io_conn *conn,
 				OPTIONAL_FEATURE(OPT_INITIAL_ROUTING_SYNC));
 
 	if (!no_init) {
-		msg = towire_init(NULL, NULL, features);
+		msg = towire_init(NULL, NULL, features, NULL);
 
 		sync_crypto_write(pps, take(msg));
 		/* Ignore their init message. */

lightningd/connect_control.c

@@ -361,7 +361,8 @@ int connectd_init(struct lightningd *ld)
 	}
 
 	msg = towire_connectctl_init(
-	    tmpctx, &ld->id,
+	    tmpctx, chainparams,
+	    &ld->id,
 	    wireaddrs,
 	    listen_announce,
 	    ld->proxyaddr, ld->use_proxy_always || ld->pure_tor_setup,

wire/extracted_peer_wire_csv

@@ -3,6 +3,9 @@ msgdata,init,gflen,u16,
 msgdata,init,globalfeatures,byte,gflen
 msgdata,init,lflen,u16,
 msgdata,init,localfeatures,byte,lflen
+msgdata,init,tlvs,init_tlvs,
+tlvtype,init_tlvs,networks,1
+tlvdata,init_tlvs,networks,chains,chain_hash,...
 msgtype,error,17
 msgdata,error,channel_id,channel_id,
 msgdata,error,len,u16,

wire/test/Makefile

@@ -21,3 +21,4 @@ ALL_TEST_PROGRAMS += $(WIRE_TEST_PROGRAMS)
 
 wire-tests: $(WIRE_TEST_PROGRAMS:%=unittest/%)
 
+wire/test/run-peer-wire: wire/gen_peer_wire.o wire/tlvstream.o common/bigsize.o

wire/test/run-peer-wire.c

@@ -1,13 +1,16 @@
-#include "../gen_peer_wire.c"
-
 #include "../towire.c"
 #include "../fromwire.c"
 #include "../peer_wire.c"
 
 #include <assert.h>
 #include <stdio.h>
+
+#include <ccan/str/hex/hex.h>
 #include <common/amount.h>
+#include <common/bigsize.h>
+#include <bitcoin/chainparams.h>
 #include <common/sphinx.h>
+#include <wire/gen_peer_wire.h>
 
 secp256k1_context *secp256k1_ctx;
 
@@ -31,24 +34,6 @@ bool amount_sat_eq(struct amount_sat a UNNEEDED, struct amount_sat b UNNEEDED)
 				       struct amount_sat a UNNEEDED,
 				       struct amount_sat b UNNEEDED)
 { fprintf(stderr, "amount_sat_sub called!\n"); abort(); }
-/* Generated stub for bigsize_get */
-size_t bigsize_get(const u8 *p UNNEEDED, size_t max UNNEEDED, bigsize_t *val UNNEEDED)
-{ fprintf(stderr, "bigsize_get called!\n"); abort(); }
-/* Generated stub for bigsize_put */
-size_t bigsize_put(u8 buf[BIGSIZE_MAX_LEN] UNNEEDED, bigsize_t v UNNEEDED)
-{ fprintf(stderr, "bigsize_put called!\n"); abort(); }
-/* Generated stub for fromwire_tlvs */
-bool fromwire_tlvs(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
-		   const struct tlv_record_type types[] UNNEEDED,
-		   size_t num_types UNNEEDED,
-		   void *record UNNEEDED)
-{ fprintf(stderr, "fromwire_tlvs called!\n"); abort(); }
-/* Generated stub for towire_tlvs */
-void towire_tlvs(u8 **pptr UNNEEDED,
-		 const struct tlv_record_type types[] UNNEEDED,
-		 size_t num_types UNNEEDED,
-		 const void *record UNNEEDED)
-{ fprintf(stderr, "towire_tlvs called!\n"); abort(); }
 /* AUTOGENERATED MOCKS END */
 
 /* memsetting pubkeys doesn't work */
@@ -236,6 +221,7 @@ struct msg_channel_announcement {
 struct msg_init {
 	u8 *globalfeatures;
 	u8 *localfeatures;
+	struct tlv_init_tlvs *tlvs;
 };
 struct msg_update_add_htlc {
 	struct channel_id channel_id;
@@ -761,16 +747,19 @@ static void *towire_struct_init(const tal_t *ctx,
 {
 	return towire_init(ctx,
 			   s->globalfeatures,
-			   s->localfeatures);
+			   s->localfeatures,
+			   s->tlvs);
 }
 
 static struct msg_init *fromwire_struct_init(const tal_t *ctx, const void *p)
 {
 	struct msg_init *s = tal(ctx, struct msg_init);
+	s->tlvs = tlv_init_tlvs_new(s);
 
 	if (!fromwire_init(s, p,
 			  &s->globalfeatures,
-			  &s->localfeatures))
+			  &s->localfeatures,
+			  s->tlvs))
 		return tal_free(s);
 
 	return s;
@@ -844,6 +833,9 @@ static bool error_eq(const struct msg_error *a,
 static bool init_eq(const struct msg_init *a,
 		    const struct msg_init *b)
 {
+	for (size_t i = 0; i < tal_count(a->tlvs->networks->chains); i++)
+		assert(bitcoin_blkid_eq(&a->tlvs->networks->chains[i],
+		                        &b->tlvs->networks->chains[i]));
 	return eq_var(a, b, globalfeatures)
 		&& eq_var(a, b, localfeatures);
 }
@@ -959,6 +951,7 @@ int main(void)
 	void *ctx = tal(NULL, char);
 	size_t i;
 	u8 *msg;
+	const struct chainparams **chains;
 
 	secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
 						 | SECP256K1_CONTEXT_SIGN);
@@ -1039,16 +1032,21 @@ int main(void)
 	assert(error_eq(&e, e2));
 	test_corruption(&e, e2, error);
 
-	memset(&init, 2, sizeof(init));
-	init.globalfeatures = tal_arr(ctx, u8, 2);
-	memset(init.globalfeatures, 2, 2);
-	init.localfeatures = tal_arr(ctx, u8, 2);
-	memset(init.localfeatures, 2, 2);
-
-	msg = towire_struct_init(ctx, &init);
-	init2 = fromwire_struct_init(ctx, msg);
-	assert(init_eq(&init, init2));
-	test_corruption(&init, init2, init);
+	chains = chainparams_for_networks(ctx);
+	for (i = 0; i < tal_count(chains); i++) {
+		memset(&init, 2, sizeof(init));
+		init.globalfeatures = tal_arr(ctx, u8, 2);
+		memset(init.globalfeatures, 2, 2);
+		init.localfeatures = tal_arr(ctx, u8, 2);
+		memset(init.localfeatures, 2, 2);
+		init.tlvs = tlv_init_tlvs_new(ctx);
+		init.tlvs->networks = tal(init.tlvs, struct tlv_init_tlvs_networks);
+		init.tlvs->networks->chains = tal_arr(ctx, struct bitcoin_blkid, 1);
+		init.tlvs->networks->chains[0] = chains[i]->genesis_blockhash;
+		msg = towire_struct_init(ctx, &init);
+		init2 = fromwire_struct_init(ctx, msg);
+		assert(init_eq(&init, init2));
+	}
 
 	memset(&uf, 2, sizeof(uf));