experimental-websocket: option to enable autodetection of WebSocket transport.

Signed-off-by: Rusty Russell <[email protected]>
Changelog-EXPERIMENTAL: Protocol: `experimental-websocket` allows Websocket connections to the Lightning port.

Author: rustyrussell

common/features.c

@@ -90,6 +90,8 @@ static const struct feature_style feature_styles[] = {
 	  .copy_style = { [INIT_FEATURE] = FEATURE_REPRESENT,
 			  [NODE_ANNOUNCE_FEATURE] = FEATURE_REPRESENT,
 			  [CHANNEL_FEATURE] = FEATURE_DONT_REPRESENT } },
+	{ OPT_WEBSOCKET,
+	  .copy_style = { [NODE_ANNOUNCE_FEATURE] = FEATURE_REPRESENT } },
 };
 
 struct dependency {
@@ -399,7 +401,7 @@ static const char *feature_name(const tal_t *ctx, size_t f)
 		NULL,
 		"option_onion_messages", /* 38/39 */
 		NULL, /* 40/41 */
-		NULL,
+		"option_websocket",
 		NULL,
 		NULL,
 		NULL,

common/features.h

@@ -135,4 +135,10 @@ const char *fmt_featurebits(const tal_t *ctx, const u8 *featurebits);
 
 #define OPT_SHUTDOWN_WRONG_FUNDING		104
 
+/* BOLT-websocket #9:
+ *
+ * | 42/43 | `option_websocket` |... N ...
+ */
+#define OPT_WEBSOCKET				42
+
 #endif /* LIGHTNING_COMMON_FEATURES_H */

doc/lightning-listconfigs.7

@@ -56,6 +56,7 @@ On success, an object is returned, containing:
 - **experimental-onion-messages** (boolean, optional): `experimental-onion-messages` field from config or cmdline, or default
 - **experimental-offers** (boolean, optional): `experimental-offers` field from config or cmdline, or default
 - **experimental-shutdown-wrong-funding** (boolean, optional): `experimental-shutdown-wrong-funding` field from config or cmdline, or default
+- **experimental-websocket** (boolean, optional): `experimental-websocket` field from config or cmdline, or default
 - **rgb** (hex, optional): `rgb` field from config or cmdline, or default (always 6 characters)
 - **alias** (string, optional): `alias` field from config or cmdline, or default
 - **pid-file** (string, optional): `pid-file` field from config or cmdline, or default
@@ -84,7 +85,7 @@ On success, an object is returned, containing:
 - **log-prefix** (string, optional): `log-prefix` field from config or cmdline, or default
 - **log-file** (string, optional): `log-file` field from config or cmdline, or default
 - **log-timestamps** (boolean, optional): `log-timestamps` field from config or cmdline, or default
-- **force-feerates** (string, optional): `force-feerates` field from config or cmdline, if any
+- **force-feerates** (string, optional): force-feerate configuration setting, if any
 - **subdaemon** (string, optional): `subdaemon` fields from config or cmdline if any (can be more than one)
 - **tor-service-password** (string, optional): `tor-service-password` field from config or cmdline, if any
 [comment]: # (GENERATE-FROM-SCHEMA-END)
@@ -204,4 +205,4 @@ RESOURCES
 ---------
 
 Main web site: <https://github.com/ElementsProject/lightning>
-[comment]: # ( SHA256STAMP:ad98179a7b6254a936d4fde179918b6a975e186adcbc396917a0c2ed2888519e)
+[comment]: # ( SHA256STAMP:6083722fadd8b5724326fc2685f05b5d056c0a6ab0752af64b10294173d1f9a2)

doc/lightning-listconfigs.7.md

@@ -145,7 +145,6 @@ What log level to print out: options are io, debug, info, unusual,
 broken\.  If \fISUBSYSTEM\fR is supplied, this sets the logging level
 for any subsystem containing that string\.  Subsystems include:
 
-
 .RS
 .IP \[bu]
 \fIlightningd\fR: The main lightning daemon
@@ -171,7 +170,6 @@ for any subsystem containing that string\.  Subsystems include:
   The following subsystems exist for each channel, where N is an incrementing
 internal integer id assigned for the lifetime of the channel:
 
-
 .RS
 .IP \[bu]
 \fIopeningd-chan#N\fR: Each opening / idling daemon
@@ -627,6 +625,14 @@ about whether to add funds or not to a proposed channel is handled
 automatically by a plugin that implements the appropriate logic for
 your needs\. The default behavior is to not contribute funds\.
 
+
+ \fBexperimental-websocket\fR
+
+
+Specifying this enables support for accepting incoming WebSocket
+connections: the normal protocol is expected to be sent over
+WebSocket binary frames once the connection is upgraded\.
+
 .SH BUGS
 
 You should report bugs on our github issues page, and maybe submit a fix
@@ -652,4 +658,4 @@ Main web site: \fIhttps://github.com/ElementsProject/lightning\fR
 Note: the modules in the ccan/ directory have their own licenses, but
 the rest of the code is covered by the BSD-style MIT license\.
 
-\" SHA256STAMP:1c392f3fee66dc6c1fc2c34200204a9be1d79e53fd5fb1720ad169fc671f71c0
+\" SHA256STAMP:114b4e458af6112500f2f01210760f1577f9e82fc74e03b6d821f669287c93b2

doc/lightningd-config.5

@@ -517,6 +517,12 @@ about whether to add funds or not to a proposed channel is handled
 automatically by a plugin that implements the appropriate logic for
 your needs. The default behavior is to not contribute funds.
 
+ **experimental-websocket**
+
+Specifying this enables support for accepting incoming WebSocket
+connections: the normal protocol is expected to be sent over
+WebSocket binary frames once the connection is upgraded.
+
 BUGS
 ----
 

doc/lightningd-config.5.md

@@ -121,6 +121,10 @@
 	    "type": "boolean",
 	    "description": "`experimental-shutdown-wrong-funding` field from config or cmdline, or default"
 	},
+	"experimental-websocket": {
+	    "type": "boolean",
+	    "description": "`experimental-websocket` field from config or cmdline, or default"
+	},
 	"rgb": {
 	    "type": "hex",
 	    "description": "`rgb` field from config or cmdline, or default",

doc/schemas/listconfigs.schema.json

@@ -363,7 +363,14 @@ int connectd_init(struct lightningd *ld)
 	int hsmfd;
 	struct wireaddr_internal *wireaddrs = ld->proposed_wireaddr;
 	enum addr_listen_announce *listen_announce = ld->proposed_listen_announce;
-	const char *websocket_helper_path = NULL;
+	const char *websocket_helper_path;
+
+	if (feature_offered(ld->our_features->bits[NODE_ANNOUNCE_FEATURE],
+			    OPT_WEBSOCKET))
+		websocket_helper_path = subdaemon_path(tmpctx, ld,
+						       "lightning_websocketd");
+	else
+		websocket_helper_path = NULL;
 
 	if (socketpair(AF_LOCAL, SOCK_STREAM, 0, fds) != 0)
 		fatal("Could not socketpair for connectd<->gossipd");

lightningd/connect_control.c

@@ -861,6 +861,14 @@ static char *opt_set_wumbo(struct lightningd *ld)
 	return NULL;
 }
 
+static char *opt_set_websocket(struct lightningd *ld)
+{
+	feature_set_or(ld->our_features,
+		       take(feature_set_for_feature(NULL,
+						    OPTIONAL_FEATURE(OPT_WEBSOCKET))));
+	return NULL;
+}
+
 static char *opt_set_dual_fund(struct lightningd *ld)
 {
 	/* Dual funding implies anchor outputs */
@@ -942,6 +950,10 @@ static void register_opts(struct lightningd *ld)
 				 " and allow peers to establish channels"
 				 " via v2 channel open protocol.");
 
+	opt_register_early_noarg("--experimental-websocket",
+				 opt_set_websocket, ld,
+				 "experimental: allow peers to connect using"
+				 " WebSockets (RFC6455)");
 	/* This affects our features, so set early. */
 	opt_register_early_noarg("--experimental-onion-messages",
 				 opt_set_onion_messages, ld,
@@ -1386,6 +1398,11 @@ static void add_config(struct lightningd *ld,
 				      feature_offered(ld->our_features
 						      ->bits[INIT_FEATURE],
 						      OPT_DUAL_FUND));
+		} else if (opt->cb == (void *)opt_set_websocket) {
+			json_add_bool(response, name0,
+				      feature_offered(ld->our_features
+						      ->bits[NODE_ANNOUNCE_FEATURE],
+						      OPT_WEBSOCKET));
 		} else if (opt->cb == (void *)opt_set_onion_messages) {
 			json_add_bool(response, name0,
 				      feature_offered(ld->our_features

lightningd/options.c

@@ -2,6 +2,7 @@
 mrkd ~= 0.1.6
 Mako ~= 1.1.3
 flake8 ~= 3.7.8
+websocket
 
 ./contrib/pyln-client
 ./contrib/pyln-proto

requirements.txt

@@ -3,6 +3,7 @@
 from fixtures import TEST_NETWORK
 from flaky import flaky  # noqa: F401
 from pyln.client import RpcError, Millisatoshi
+import pyln.proto.wire as wire
 from utils import (
     only_one, wait_for, sync_blockheight, TIMEOUT,
     expected_peer_features, expected_node_features,
@@ -20,6 +21,7 @@
 import shutil
 import time
 import unittest
+import websocket
 
 
 def test_connect(node_factory):
@@ -3734,3 +3736,51 @@ def test_old_feerate(node_factory):
 
     # This will timeout if l2 didn't accept fee.
     l1.pay(l2, 1000)
+
+
+def test_websocket(node_factory):
+    l1 = node_factory.get_node(options={'experimental-websocket': None, 'log-level': 'io'})
+    assert l1.rpc.listconfigs()['experimental-websocket']
+
+    # Adapter to turn websocket into a stream "connection"
+    class BinWebSocket(object):
+        def __init__(self, hostname, port):
+            self.ws = websocket.WebSocket()
+            self.ws.connect("ws://" + hostname + ":" + str(port))
+            self.recvbuf = bytes()
+
+        def send(self, data):
+            self.ws.send(data, websocket.ABNF.OPCODE_BINARY)
+
+        def recv(self, maxlen):
+            while len(self.recvbuf) < maxlen:
+                self.recvbuf += self.ws.recv()
+
+            ret = self.recvbuf[:maxlen]
+            self.recvbuf = self.recvbuf[maxlen:]
+            return ret
+
+    ws = BinWebSocket('localhost', l1.port)
+    lconn = wire.LightningConnection(ws,
+                                     wire.PublicKey(bytes.fromhex(l1.info['id'])),
+                                     wire.PrivateKey(bytes([1] * 32)),
+                                     is_initiator=True)
+    # Perform handshake.
+    lconn.shake()
+
+    # Expect to receive init msg.
+    msg = lconn.read_message()
+    assert int.from_bytes(msg[0:2], 'big') == 16
+
+    # Echo same message back.
+    lconn.send_message(msg)
+
+    # Now try sending a ping, ask for 50 bytes
+    msg = bytes((0, 18, 0, 50, 0, 0))
+    lconn.send_message(msg)
+
+    # Could actually reply with some gossip msg!
+    while True:
+        msg = lconn.read_message()
+        if int.from_bytes(msg[0:2], 'big') == 19:
+            break