channeld_fakenet: fake channeld to simulate network given a gossmap_store.

Our gossmap_store uncompresser generates nodeids with well-known
privkeys, so we can decrypt and respond to HTLCs sent to such nodes.
By replacing channeld with a fake, we can connect a node to another
node, but then once the channel is established, allow payments to be
sent into the generated network, and respond appropriately.

This minimal version handles MPP timeouts, but doesn't insert any
delays or runtime capacity for channels.

Signed-off-by: Rusty Russell <[email protected]>
Changelog-None: Testing only

Author: rustyrussell

Makefile

@@ -840,6 +840,7 @@ install: install-program install-data
 TESTBINS = \
 	$(CLN_PLUGIN_EXAMPLES) \
 	tests/plugins/test_libplugin \
+	tests/plugins/channeld_fakenet \
 	tests/plugins/test_selfdisable_after_getmanifest \
 	tools/hsmtool
 

tests/plugins/Makefile

@@ -10,6 +10,90 @@ PLUGIN_TESTSELFDISABLE_AFTER_GETMANIFEST_OBJS := $(PLUGIN_TESTSELFDISABLE_AFTER_
 
 tests/plugins/test_selfdisable_after_getmanifest: bitcoin/chainparams.o $(PLUGIN_TESTSELFDISABLE_AFTER_GETMANIFEST_OBJS) common/autodata.o common/json_parse_simple.o common/setup.o common/utils.o $(JSMN_OBJS)
 
+tests/plugins/channeld_fakenet:			\
+	tests/plugins/channeld_fakenet.o	\
+	channeld/channeld_wiregen.o		\
+	channeld/commit_tx.o			\
+	bitcoin/block.o				\
+	bitcoin/chainparams.o			\
+	bitcoin/pubkey.o			\
+	bitcoin/short_channel_id.o		\
+	bitcoin/locktime.o			\
+	bitcoin/preimage.o			\
+	bitcoin/privkey.o			\
+	bitcoin/psbt.o				\
+	bitcoin/signature.o			\
+	bitcoin/tx.o				\
+	bitcoin/script.o			\
+	bitcoin/shadouble.o			\
+	bitcoin/varint.o			\
+	channeld/full_channel.o			\
+	channeld/inflight.o			\
+	common/amount.o				\
+	common/autodata.o			\
+	common/base32.o				\
+	common/bigsize.o			\
+	common/billboard.o			\
+	common/bip32.o				\
+	common/blinding.o			\
+	common/blindedpath.o			\
+	common/blockheight_states.o		\
+	common/channel_config.o			\
+	common/channel_id.o			\
+	common/channel_type.o			\
+	common/daemon.o				\
+	common/daemon_conn.o			\
+	common/derive_basepoints.o		\
+	common/features.o			\
+	common/fee_states.o			\
+	common/peer_io.o			\
+	common/peer_status_wiregen.o		\
+	common/status_wiregen.o			\
+	common/gossip_store.o			\
+	common/gossmap.o			\
+	common/hmac.o				\
+	common/htlc_state.o			\
+	common/htlc_trim.o			\
+	common/htlc_tx.o			\
+	common/htlc_wire.o			\
+	common/initial_channel.o		\
+	common/initial_commit_tx.o		\
+	common/keyset.o				\
+	common/key_derive.o			\
+	common/memleak.o			\
+	common/msg_queue.o			\
+	common/node_id.o			\
+	common/onion_decode.o			\
+	common/onionreply.o			\
+	common/peer_billboard.o			\
+	common/peer_failed.o			\
+	common/penalty_base.o			\
+	common/per_peer_state.o			\
+	common/permute_tx.o			\
+	common/pseudorand.o			\
+	common/setup.o				\
+	common/sphinx.o				\
+	common/status.o				\
+	common/status_wire.o			\
+	common/subdaemon.o			\
+	common/timeout.o			\
+	common/utils.o				\
+	common/version.o			\
+	common/wire_error.o			\
+	common/wireaddr.o			\
+	common/fp16.o				\
+	common/sciddir_or_pubkey.o		\
+	wire/fromwire.o				\
+	wire/wire_io.o				\
+	wire/peer_wire.o			\
+	wire/peer_wiregen.o			\
+	wire/onion_wiregen.o			\
+	wire/towire.o				\
+	wire/channel_type_wiregen.o		\
+	wire/tlvstream.o			\
+	wire/wire_sync.o
+
+
 # Make sure these depend on everything.
-ALL_TEST_PROGRAMS += tests/plugins/test_libplugin tests/plugins/test_selfdisable_after_getmanifest
-ALL_C_SOURCES += $(PLUGIN_TESTLIBPLUGIN_SRC) $(PLUGIN_TESTSELFDISABLE_AFTER_GETMANIFEST_SRC)
+ALL_TEST_PROGRAMS += tests/plugins/test_libplugin tests/plugins/test_selfdisable_after_getmanifest tests/plugins/channeld_fakenet
+ALL_C_SOURCES += $(PLUGIN_TESTLIBPLUGIN_SRC) $(PLUGIN_TESTSELFDISABLE_AFTER_GETMANIFEST_SRC) $(PLUGIN_CHANNELD_FAKENET)