lightningd_gossip: daemon to look after peers which don't a channel (yet)

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

lightningd/Makefile

@@ -4,7 +4,7 @@
 lightningd-wrongdir:
 	$(MAKE) -C .. lightningd-all
 
-lightningd-all: lightningd/lightningd lightningd/lightningd_hsm lightningd/lightningd_handshake
+lightningd-all: lightningd/lightningd lightningd/lightningd_hsm lightningd/lightningd_handshake lightningd/lightningd_gossip
 
 default: lightningd-all
 
@@ -51,6 +51,7 @@ $(LIGHTNINGD_OBJS) $(LIGHTNINGD_LIB_OBJS): $(LIGHTNINGD_HEADERS) $(LIGHTNINGD_JS
 
 include lightningd/hsm/Makefile
 include lightningd/handshake/Makefile
+include lightningd/gossip/Makefile
 
 check-source: $(LIGHTNINGD_SRC:%=check-src-include-order/%)
 check-source: $(LIGHTNINGD_LIB_SRC:%=check-src-include-order/%)

lightningd/gossip/Makefile

@@ -0,0 +1,55 @@
+#! /usr/bin/make
+
+# Designed to be run one level up
+lightningd/gossip-wrongdir:
+	$(MAKE) -C .. lightningd/gossip-all
+
+default: lightningd/gossip-all
+
+# Control daemon uses this:
+LIGHTNINGD_GOSSIP_CONTROL_HEADERS := lightningd/gossip/gen_gossip_control_wire.h \
+	lightningd/gossip/gen_gossip_status_wire.h
+LIGHTNINGD_GOSSIP_CONTROL_SRC := lightningd/gossip/gen_gossip_control_wire.c \
+	lightningd/gossip/gen_gossip_status_wire.c
+LIGHTNINGD_GOSSIP_CONTROL_OBJS := $(LIGHTNINGD_GOSSIP_CONTROL_SRC:.c=.o)
+
+# lightningd/gossip needs these:
+LIGHTNINGD_GOSSIP_HEADERS := lightningd/gossip/gen_gossip_control_wire.h \
+	lightningd/gossip/gen_gossip_status_wire.h
+LIGHTNINGD_GOSSIP_SRC := lightningd/gossip/gossip.c	\
+	$(LIGHTNINGD_GOSSIP_HEADERS:.h=.c)
+LIGHTNINGD_GOSSIP_OBJS := $(LIGHTNINGD_GOSSIP_SRC:.c=.o)
+
+# For checking
+LIGHTNINGD_GOSSIP_ALLSRC_NOGEN := $(filter-out lightningd/gossip/gen_%, $(LIGHTNINGD_GOSSIP_CLIENT_SRC) $(LIGHTNINGD_GOSSIP_SRC))
+LIGHTNINGD_GOSSIP_ALLHEADERS_NOGEN := $(filter-out lightningd/gossip/gen_%, $(LIGHTNINGD_GOSSIP_CLIENT_HEADERS) $(LIGHTNINGD_GOSSIP_HEADERS))
+
+$(LIGHTNINGD_GOSSIP_OBJS) $(LIGHTNINGD_GOSSIP_CLIENT_OBJS): $(CCAN_HEADERS) $(CORE_HEADERS) $(BITCOIN_HEADERS) $(GEN_HEADERS) $(WIRE_HEADERS) $(LIGHTNINGD_GOSSIP_HEADERS) $(LIGHTNINGD_GOSSIP_GEN_HEADERS) $(LIGHTNINGD_LIB_HEADERS) $(LIBBASE58_HEADERS)
+
+lightningd/gossip-all: lightningd/lightningd_gossip $(LIGHTNINGD_GOSSIP_CLIENT_OBJS)
+
+lightningd/lightningd_gossip: $(LIGHTNINGD_GOSSIP_OBJS) $(CORE_OBJS) $(BITCOIN_OBJS) $(WIRE_OBJS) $(CCAN_OBJS) $(LIGHTNINGD_LIB_OBJS) $(LIBBASE58_OBJS) libsecp256k1.a
+	$(CC) $(CFLAGS) -o $@ $^ $(LDLIBS)
+
+lightningd/gossip/gen_gossip_control_wire.h: $(WIRE_GEN) lightningd/gossip/gossip_control_wire_csv
+	$(WIRE_GEN) --header $@ gossip_control_wire_type < lightningd/gossip/gossip_control_wire_csv > $@
+
+lightningd/gossip/gen_gossip_control_wire.c: $(WIRE_GEN) lightningd/gossip/gossip_control_wire_csv
+	$(WIRE_GEN) ${@:.c=.h} gossip_control_wire_type < lightningd/gossip/gossip_control_wire_csv > $@
+
+lightningd/gossip/gen_gossip_status_wire.h: $(WIRE_GEN) lightningd/gossip/gossip_status_wire_csv
+	$(WIRE_GEN) --header $@ gossip_status_wire_type < lightningd/gossip/gossip_status_wire_csv > $@
+
+lightningd/gossip/gen_gossip_status_wire.c: $(WIRE_GEN) lightningd/gossip/gossip_status_wire_csv
+	$(WIRE_GEN) ${@:.c=.h} gossip_status_wire_type < lightningd/gossip/gossip_status_wire_csv > $@
+
+check-source: $(LIGHTNINGD_GOSSIP_ALLSRC_NOGEN:%=check-src-include-order/%) $(LIGHTNINGD_GOSSIP_ALLHEADERS_NOGEN:%=check-hdr-include-order/%)
+check-source-bolt: $(LIGHTNINGD_GOSSIP_SRC:%=bolt-check/%) $(LIGHTNINGD_GOSSIP_HEADERS:%=bolt-check/%)
+check-whitespace: $(LIGHTNINGD_GOSSIP_ALLSRC_NOGEN:%=check-whitespace/%) $(LIGHTNINGD_GOSSIP_ALLHEADERS_NOGEN:%=check-whitespace/%)
+
+clean: lightningd/gossip-clean
+
+lightningd/gossip-clean:
+	$(RM) $(LIGHTNINGD_GOSSIP_OBJS) gen_*
+
+-include lightningd/gossip/test/Makefile 

lightningd/gossip/gossip.c

@@ -0,0 +1,323 @@
+#include <ccan/breakpoint/breakpoint.h>
+#include <ccan/container_of/container_of.h>
+#include <ccan/crypto/hkdf_sha256/hkdf_sha256.h>
+#include <ccan/endian/endian.h>
+#include <ccan/fdpass/fdpass.h>
+#include <ccan/io/fdpass/fdpass.h>
+#include <ccan/io/io.h>
+#include <ccan/list/list.h>
+#include <ccan/noerr/noerr.h>
+#include <ccan/read_write_all/read_write_all.h>
+#include <ccan/tal/str/str.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <lightningd/gossip/gen_gossip_control_wire.h>
+#include <lightningd/gossip/gen_gossip_status_wire.h>
+#include <secp256k1_ecdh.h>
+#include <sodium/randombytes.h>
+#include <status.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <utils.h>
+#include <version.h>
+#include <wire/gen_peer_wire.h>
+#include <wire/wire_io.h>
+
+struct daemon {
+	struct list_head peers;
+	u8 *msg_in;
+};
+
+struct peer {
+	struct daemon *daemon;
+	/* daemon->peers */
+	struct list_node list;
+
+	u64 unique_id;
+	struct crypto_state *cs;
+
+	/* File descriptor corresponding to conn. */
+	int fd;
+	/* Our connection (and owner) */
+	struct io_conn *conn;
+
+	/* If this is non-NULL, it means we failed. */
+	const char *error;
+};
+
+static void destroy_peer(struct peer *peer)
+{
+	list_del_from(&peer->daemon->peers, &peer->list);
+	if (peer->error)
+		status_send(towire_gossipstatus_peer_bad_msg(peer,
+							     peer->unique_id,
+							     (u8 *)peer->error));
+}
+
+static struct peer *setup_new_peer(struct daemon *daemon, const u8 *msg)
+{
+	struct peer *peer = tal(daemon, struct peer);
+	if (!fromwire_gossipctl_new_peer(peer, msg, NULL,
+					 &peer->unique_id, &peer->cs))
+		return tal_free(peer);
+	peer->daemon = daemon;
+	peer->error = NULL;
+	list_add_tail(&daemon->peers, &peer->list);
+	tal_add_destructor(peer, destroy_peer);
+	return peer;
+}
+
+static struct io_plan *peer_msgin(struct io_conn *conn,
+				  struct peer *peer, u8 *msg)
+{
+	u8 *s;
+	enum wire_type t = fromwire_peektype(msg);
+
+	switch (t) {
+	case WIRE_ERROR:
+		/* FIXME: Report error from msg. */
+		peer->error = "ERROR message received";
+		return io_close(conn);
+
+	case WIRE_CHANNEL_ANNOUNCEMENT:
+	case WIRE_NODE_ANNOUNCEMENT:
+	case WIRE_CHANNEL_UPDATE:
+		/* FIXME: Handle gossip! */
+		return peer_read_message(conn, peer->cs, peer_msgin);
+
+	case WIRE_INIT:
+		peer->error = "Duplicate INIT message received";
+		return io_close(conn);
+
+	case WIRE_OPEN_CHANNEL:
+	case WIRE_ACCEPT_CHANNEL:
+	case WIRE_FUNDING_CREATED:
+	case WIRE_FUNDING_SIGNED:
+	case WIRE_FUNDING_LOCKED:
+	case WIRE_UPDATE_FEE:
+	case WIRE_SHUTDOWN:
+	case WIRE_CLOSING_SIGNED:
+	case WIRE_UPDATE_ADD_HTLC:
+	case WIRE_UPDATE_FULFILL_HTLC:
+	case WIRE_UPDATE_FAIL_HTLC:
+	case WIRE_UPDATE_FAIL_MALFORMED_HTLC:
+	case WIRE_COMMIT_SIG:
+	case WIRE_REVOKE_AND_ACK:
+		/* Not our place to handle this, so we punt */
+		s = towire_gossipstatus_peer_nongossip(msg, peer->unique_id,
+						       peer->cs, msg);
+		status_send(s);
+		status_send_fd(io_conn_fd(conn));
+		return io_close(conn);
+	}
+
+	/* BOLT #1:
+	 *
+	 * The type follows the _it's ok to be odd_ rule, so nodes MAY send
+	 * odd-numbered types without ascertaining that the recipient
+	 * understands it. */
+	if (t & 1) {
+		status_trace("Peer %"PRIu64" sent unknown packet %u, ignoring",
+			     peer->unique_id, t);
+		return peer_read_message(conn, peer->cs, peer_msgin);
+	}
+	peer->error = tal_fmt(peer, "Unknown packet %u", t);
+	return io_close(conn);
+}
+
+static struct io_plan *peer_dump_gossip(struct io_conn *conn, struct peer *peer)
+{
+	/* FIXME: Dump gossip here, then when done... */
+	return peer_read_message(conn, peer->cs, peer_msgin);
+}
+
+static bool has_even_bit(const u8 *bitmap)
+{
+	size_t len = tal_count(bitmap);
+
+	while (len) {
+		if (*bitmap & 0xAA)
+			return true;
+		len--;
+		bitmap++;
+	}
+	return false;
+}
+
+static struct io_plan *peer_parse_init(struct io_conn *conn,
+				       struct peer *peer, u8 *msg)
+{
+	u8 *gfeatures, *lfeatures;
+
+	if (!fromwire_init(msg, msg, NULL, &gfeatures, &lfeatures)) {
+		peer->error = tal_fmt(msg, "Bad init: %s", tal_hex(msg, msg));
+		return io_close(conn);
+	}
+
+	/* BOLT #1:
+	 *
+	 * The receiving node MUST fail the channels if it receives a
+	 * `globalfeatures` or `localfeatures` with an even bit set which it
+	 * does not understand.
+	 */
+	if (has_even_bit(gfeatures)) {
+		peer->error = tal_fmt(msg, "Bad globalfeatures: %s",
+				      tal_hex(msg, gfeatures));
+		return io_close(conn);
+	}
+
+	if (has_even_bit(lfeatures)) {
+		peer->error = tal_fmt(msg, "Bad localfeatures: %s",
+				      tal_hex(msg, lfeatures));
+		return io_close(conn);
+	}
+
+	/* BOLT #1:
+	 *
+	 * Each node MUST wait to receive `init` before sending any other
+	 * messages.
+	 */
+	status_send(towire_gossipstatus_peer_ready(msg, peer->unique_id));
+
+	return peer_dump_gossip(conn, peer);
+}
+
+static struct io_plan *peer_init_sent(struct io_conn *conn, struct peer *peer)
+{
+	return peer_read_message(conn, peer->cs, peer_parse_init);
+}
+
+static struct io_plan *peer_send_init(struct io_conn *conn, struct peer *peer)
+{
+	/* BOLT #1:
+	 *
+	 * The sending node SHOULD use the minimum lengths required to
+	 * represent the feature fields.  The sending node MUST set feature
+	 * bits corresponding to features it requires the peer to support, and
+	 * SHOULD set feature bits corresponding to features it optionally
+	 * supports.
+	 */
+	return peer_write_message(conn, peer->cs, towire_init(peer, NULL, NULL),
+				  peer_init_sent);
+}
+
+static struct io_plan *next_req_in(struct io_conn *conn, struct daemon *daemon);
+
+static struct io_plan *new_peer_got_fd(struct io_conn *conn, struct peer *peer)
+{
+	peer->conn = io_new_conn(conn, peer->fd, peer_send_init, peer);
+	if (!peer->conn) {
+		peer->error = "Could not create connection";
+		tal_free(peer);
+	} else
+		/* Free peer if conn closed. */
+		tal_steal(peer->conn, peer);
+
+	return next_req_in(conn, peer->daemon);
+}
+
+static struct io_plan *new_peer(struct io_conn *conn, struct daemon *daemon,
+				const u8 *msg)
+{
+	struct peer *peer = setup_new_peer(daemon, msg);
+	if (!peer)
+		status_failed(WIRE_GOSSIPSTATUS_BAD_NEW_PEER_REQUEST,
+			      "%s", tal_hex(trc, msg));
+	return io_recv_fd(conn, &peer->fd, new_peer_got_fd, peer);
+}
+
+static struct io_plan *release_peer_fd(struct io_conn *conn, struct peer *peer)
+{
+	int fd = peer->fd;
+	struct daemon *daemon = peer->daemon;
+
+	tal_free(peer);
+	return io_send_fd(conn, fd, next_req_in, daemon);
+}
+
+static struct io_plan *release_peer(struct io_conn *conn, struct daemon *daemon,
+				    const u8 *msg)
+{
+	u64 unique_id;
+	struct peer *peer;
+
+	if (!fromwire_gossipctl_release_peer(msg, NULL, &unique_id))
+		status_failed(WIRE_GOSSIPSTATUS_BAD_RELEASE_REQUEST,
+			      "%s", tal_hex(trc, msg));
+
+	list_for_each(&daemon->peers, peer, list) {
+		if (peer->unique_id == unique_id) {
+			u8 *out;
+
+			/* Don't talk to this peer any more. */
+			peer->fd = io_conn_fd(peer->conn);
+			tal_steal(daemon, peer);
+			io_close_taken_fd(peer->conn);
+
+			out = towire_gossipctl_release_peer_response(msg,
+								     unique_id,
+								     peer->cs);
+			return io_write_wire(conn, out, release_peer_fd, peer);
+		}
+	}
+	status_failed(WIRE_GOSSIPSTATUS_BAD_RELEASE_REQUEST,
+		      "Unknown peer %"PRIu64, unique_id);
+}
+
+static struct io_plan *recv_req(struct io_conn *conn, struct daemon *daemon)
+{
+	enum gossip_control_wire_type t = fromwire_peektype(daemon->msg_in);
+
+	status_trace("req: type %s len %zu",
+		     gossip_control_wire_type_name(t),
+		     tal_count(daemon->msg_in));
+
+	switch (t) {
+	case WIRE_GOSSIPCTL_NEW_PEER:
+		return new_peer(conn, daemon, daemon->msg_in);
+	case WIRE_GOSSIPCTL_RELEASE_PEER:
+		return release_peer(conn, daemon, daemon->msg_in);
+
+	case WIRE_GOSSIPCTL_RELEASE_PEER_RESPONSE:
+		break;
+	}
+
+	/* Control shouldn't give bad requests. */
+	status_failed(WIRE_GOSSIPSTATUS_BAD_REQUEST, "%i", t);
+}
+
+static struct io_plan *next_req_in(struct io_conn *conn, struct daemon *daemon)
+{
+	daemon->msg_in = tal_free(daemon->msg_in);
+	return io_read_wire(conn, daemon, &daemon->msg_in, recv_req, daemon);
+}
+
+#ifndef TESTING
+int main(int argc, char *argv[])
+{
+	struct daemon *daemon;
+
+	breakpoint();
+
+	if (argc == 2 && streq(argv[1], "--version")) {
+		printf("%s\n", version());
+		exit(0);
+	}
+
+	daemon = tal(NULL, struct daemon);
+	list_head_init(&daemon->peers);
+	daemon->msg_in = NULL;
+
+	/* Stdout == status, stdin == requests */
+	status_setup(STDOUT_FILENO);
+
+	io_new_conn(NULL, STDIN_FILENO, next_req_in, daemon);
+	io_loop(NULL, NULL);
+
+	tal_free(daemon);
+	return 0;
+}
+#endif

lightningd/gossip/gossip_control_wire_csv

@@ -0,0 +1,16 @@
+#include <lightningd/cryptomsg.h>
+
+# These take an fd, but have no response
+# (if it is to move onto a channel, we get a status msg).
+gossipctl_new_peer,1
+gossipctl_new_peer,0,unique_id,8
+gossipctl_new_peer,8,crypto_state,144,struct crypto_state
+
+# Tell it to release a peer which has initialized.
+gossipctl_release_peer,2
+gossipctl_release_peer,0,unique_id,8
+
+# This releases the peer and returns the cryptostate (followed by fd)
+gossipctl_release_peer_response,102
+gossipctl_release_peer_response,0,unique_id,8
+gossipctl_release_peer_response,8,crypto_state,144,struct crypto_state

lightningd/gossip/gossip_status_wire_csv

@@ -0,0 +1,33 @@
+#include <lightningd/cryptomsg.h>
+
+# These are fatal.
+gossipstatus_init_failed,0x8000
+gossipstatus_bad_new_peer_request,0x8001
+gossipstatus_bad_release_request,0x8002
+gossipstatus_bad_request,0x8003
+gossipstatus_fdpass_failed,0x8004
+
+# Peers can give a bad message, we close their fd, but no harm done.
+gossipstatus_peer_bad_msg,100
+gossipstatus_peer_bad_msg,0,unique_id,8
+gossipstatus_peer_bad_msg,8,len,2
+gossipstatus_peer_bad_msg,10,err,len,u8
+
+# This is where we save a peer's features.
+#gossipstatus_peer_features,1
+#gossipstatus_peer_features,0,unique_id,8
+#gossipstatus_peer_features,8,gflen,2
+#gossipstatus_peer_features,10,globalfeatures,gflen
+#gossipstatus_peer_features,10+gflen,lflen,2
+#gossipstatus_peer_features,12+gflen,localfeatures,lflen
+
+# Peer init handshake complete (now you can release_peer if you want)
+gossipstatus_peer_ready,2
+gossipstatus_peer_ready,0,unique_id,8
+
+# Peer can send non-gossip packet (usually an open_channel) (followed by fd)
+gossipstatus_peer_nongossip,3
+gossipstatus_peer_nongossip,0,unique_id,8
+gossipstatus_peer_nongossip,10,crypto_state,144,struct crypto_state
+gossipstatus_peer_nongossip,154,len,2
+gossipstatus_peer_nongossip,156,msg,len,u8

lightningd/lightningd.c

@@ -101,7 +101,8 @@ static struct lightningd *new_lightningd(const tal_t *ctx)
 static const char *daemons[] = {
 	"lightningd",
 	"lightningd_hsm",
-	"lightningd_handshake"
+	"lightningd_handshake",
+	"lightningd_gossip"
 };
 
 /* Check we can run them, and check their versions */