common: generalize extract_channel_id().

connectd is going to end up using this do demux; make it fast and complete.

Fixing this reveals a problem in openingd: it now extracts the channel_id
from funding_signed (which is where we transition off the temporary), and
gets upset.  So fix that.

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

channeld/test/run-commit_tx.c

@@ -24,7 +24,7 @@ static bool print_superverbose;
 bigsize_t fromwire_bigsize(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bigsize called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */

cli/test/run-human-mode.c

@@ -70,7 +70,7 @@ struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UN
 bigsize_t fromwire_bigsize(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bigsize called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */

cli/test/run-large-input.c

@@ -70,7 +70,7 @@ struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UN
 bigsize_t fromwire_bigsize(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bigsize called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */

cli/test/run-remove-hint.c

@@ -73,7 +73,7 @@ struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UN
 bigsize_t fromwire_bigsize(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bigsize called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */

common/channel_id.c

@@ -88,10 +88,10 @@ void towire_channel_id(u8 **pptr, const struct channel_id *channel_id)
 	towire(pptr, channel_id, sizeof(*channel_id));
 }
 
-void fromwire_channel_id(const u8 **cursor, size_t *max,
+bool fromwire_channel_id(const u8 **cursor, size_t *max,
 			 struct channel_id *channel_id)
 {
-	fromwire(cursor, max, channel_id, sizeof(*channel_id));
+	return fromwire(cursor, max, channel_id, sizeof(*channel_id)) != NULL;
 }
 
 REGISTER_TYPE_TO_HEXSTR(channel_id);

common/channel_id.h

@@ -38,6 +38,6 @@ void derive_tmp_channel_id(struct channel_id *channel_id,
 
 /* Marshalling/unmarshalling functions */
 void towire_channel_id(u8 **pptr, const struct channel_id *channel_id);
-void fromwire_channel_id(const u8 **cursor, size_t *max,
+bool fromwire_channel_id(const u8 **cursor, size_t *max,
 			 struct channel_id *channel_id);
 #endif /* LIGHTNING_COMMON_CHANNEL_ID_H */

common/read_peer_msg.c

@@ -103,6 +103,9 @@ bool is_peer_error(const tal_t *ctx, const u8 *msg,
 bool is_wrong_channel(const u8 *msg, const struct channel_id *expected,
 		      struct channel_id *actual)
 {
+	if (!expected)
+		return false;
+
 	if (!extract_channel_id(msg, actual))
 		return false;
 

common/test/run-blindedpath_enctlv.c

@@ -50,7 +50,7 @@ struct amount_msat fromwire_amount_msat(const u8 **cursor UNNEEDED, size_t *max
 struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_amount_sat called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */

common/test/run-blindedpath_onion.c

@@ -56,7 +56,7 @@ struct amount_msat fromwire_amount_msat(const u8 **cursor UNNEEDED, size_t *max
 struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_amount_sat called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */

common/test/run-bolt12_merkle-json.c

@@ -19,7 +19,7 @@
 
 /* AUTOGENERATED MOCKS START */
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */

common/test/run-bolt12_merkle.c

@@ -22,7 +22,7 @@ int features_unsupported(const struct feature_set *our_features UNNEEDED,
 			 enum feature_place p UNNEEDED)
 { fprintf(stderr, "features_unsupported called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_onionmsg_path */

common/test/run-gossmap_local.c

@@ -16,7 +16,7 @@
 bigsize_t fromwire_bigsize(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bigsize called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for towire_bigsize */

common/test/run-route-specific.c

@@ -25,7 +25,7 @@
 bigsize_t fromwire_bigsize(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bigsize called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_tlv */

common/test/run-route.c

@@ -18,7 +18,7 @@
 bigsize_t fromwire_bigsize(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bigsize called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_tlv */

common/test/run-route_blinding_override_test.c

@@ -63,7 +63,7 @@ struct amount_msat fromwire_amount_msat(const u8 **cursor UNNEEDED, size_t *max
 struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_amount_sat called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */

common/test/run-route_blinding_test.c

@@ -63,7 +63,7 @@ struct amount_msat fromwire_amount_msat(const u8 **cursor UNNEEDED, size_t *max
 struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_amount_sat called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */

lightningd/test/run-find_my_abspath.c

@@ -73,7 +73,7 @@ void free_htlcs(struct lightningd *ld UNNEEDED, const struct channel *channel UN
 bigsize_t fromwire_bigsize(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bigsize called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */

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

@@ -203,7 +203,7 @@ void fixup_htlcs_out(struct lightningd *ld UNNEEDED)
 bigsize_t fromwire_bigsize(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bigsize called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_channeld_dev_memleak_reply */

lightningd/test/run-jsonrpc.c

@@ -22,7 +22,7 @@ const char *feerate_name(enum feerate feerate UNNEEDED)
 bigsize_t fromwire_bigsize(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bigsize called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */

lightningd/test/run-log-pruning.c

@@ -21,7 +21,7 @@ struct command_result *command_success(struct command *cmd UNNEEDED,
 bigsize_t fromwire_bigsize(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bigsize called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */

lightningd/test/run-shuffle_fds.c

@@ -57,7 +57,7 @@ void   fatal(const char *fmt UNNEEDED, ...)
 bigsize_t fromwire_bigsize(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bigsize called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */

openingd/openingd.c

@@ -177,7 +177,8 @@ static void set_reserve(struct state *state, const struct amount_sat dust_limit)
 /*~ Handle random messages we might get during opening negotiation, (eg. gossip)
  * returning the first non-handled one, or NULL if we aborted negotiation. */
 static u8 *opening_negotiate_msg(const tal_t *ctx, struct state *state,
-				 bool am_opener)
+				 bool am_opener,
+				 const struct channel_id *alternate)
 {
 	/* This is an event loop of its own.  That's generally considered poor
 	 * form, but we use it in a very limited way. */
@@ -250,7 +251,8 @@ static u8 *opening_negotiate_msg(const tal_t *ctx, struct state *state,
 		 * keeps things simple: if we wanted to change this, we would
 		 * probably be best with another daemon to de-multiplex them;
 		 * this could be connectd itself, in fact. */
-		if (is_wrong_channel(msg, &state->channel_id, &actual)) {
+		if (is_wrong_channel(msg, &state->channel_id, &actual)
+		    && is_wrong_channel(msg, alternate, &actual)) {
 			status_debug("Rejecting %s for unknown channel_id %s",
 				     peer_wire_name(fromwire_peektype(msg)),
 				     type_to_string(tmpctx, struct channel_id,
@@ -401,7 +403,7 @@ static u8 *funder_channel_start(struct state *state, u8 channel_flags)
 		       "Funding channel start: offered, now waiting for accept_channel");
 
 	/* ... since their reply should be immediate. */
-	msg = opening_negotiate_msg(tmpctx, state, true);
+	msg = opening_negotiate_msg(tmpctx, state, true, NULL);
 	if (!msg)
 		return NULL;
 
@@ -652,8 +654,10 @@ static bool funder_finalize_channel_setup(struct state *state,
 		       "Funding channel: create first tx, now waiting for their signature");
 
 	/* Now they send us their signature for that first commitment
-	 * transaction. */
-	msg = opening_negotiate_msg(tmpctx, state, true);
+	 * transaction.  Note that errors may refer to the temporary channel
+	 * id (state->channel_id), but success should refer to the new
+	 * "cid" */
+	msg = opening_negotiate_msg(tmpctx, state, true, &cid);
 	if (!msg)
 		goto fail;
 
@@ -1052,7 +1056,7 @@ static u8 *fundee_channel(struct state *state, const u8 *open_channel_msg)
 		       "Incoming channel: accepted, now waiting for them to create funding tx");
 
 	/* This is a loop which handles gossip until we get a non-gossip msg */
-	msg = opening_negotiate_msg(tmpctx, state, false);
+	msg = opening_negotiate_msg(tmpctx, state, false, NULL);
 	if (!msg)
 		return NULL;
 

plugins/test/run-funder_policy.c

@@ -9,7 +9,7 @@
 bigsize_t fromwire_bigsize(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bigsize called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */

plugins/test/run-route-overlong.c

@@ -21,7 +21,7 @@ bool feature_offered(const u8 *features UNNEEDED, size_t f UNNEEDED)
 bigsize_t fromwire_bigsize(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bigsize called!\n"); abort(); }
 /* Generated stub for fromwire_channel_id */
-void fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
+bool fromwire_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			 struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "fromwire_channel_id called!\n"); abort(); }
 /* Generated stub for json_add_amount_msat_compat */