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gossipd.c
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/*~ Welcome to the gossip daemon: keeper of maps!
*
* This is the last "global" daemon; it has three purposes.
*
* 1. To determine routes for payments when lightningd asks.
* 2. The second purpose is to receive gossip from peers (via their
* per-peer daemons) and send it out to them.
* 3. Talk to `connectd` to to answer address queries for nodes.
*
* The gossip protocol itself is fairly simple, but has some twists which
* add complexity to this daemon.
*/
#include <bitcoin/chainparams.h>
#include <ccan/array_size/array_size.h>
#include <ccan/build_assert/build_assert.h>
#include <ccan/cast/cast.h>
#include <ccan/container_of/container_of.h>
#include <ccan/crypto/hkdf_sha256/hkdf_sha256.h>
#include <ccan/crypto/siphash24/siphash24.h>
#include <ccan/endian/endian.h>
#include <ccan/fdpass/fdpass.h>
#include <ccan/io/fdpass/fdpass.h>
#include <ccan/io/io.h>
#include <ccan/mem/mem.h>
#include <ccan/noerr/noerr.h>
#include <ccan/take/take.h>
#include <ccan/tal/str/str.h>
#include <common/bech32.h>
#include <common/bech32_util.h>
#include <common/cryptomsg.h>
#include <common/daemon_conn.h>
#include <common/features.h>
#include <common/memleak.h>
#include <common/ping.h>
#include <common/pseudorand.h>
#include <common/status.h>
#include <common/subdaemon.h>
#include <common/timeout.h>
#include <common/type_to_string.h>
#include <common/utils.h>
#include <common/version.h>
#include <common/wire_error.h>
#include <common/wireaddr.h>
#include <connectd/gen_connect_gossip_wire.h>
#include <errno.h>
#include <fcntl.h>
#include <gossipd/broadcast.h>
#include <gossipd/gen_gossip_peerd_wire.h>
#include <gossipd/gen_gossip_wire.h>
#include <gossipd/gossip_generation.h>
#include <gossipd/gossipd.h>
#include <gossipd/queries.h>
#include <gossipd/routing.h>
#include <gossipd/seeker.h>
#include <inttypes.h>
#include <lightningd/gossip_msg.h>
#include <netdb.h>
#include <netinet/in.h>
#include <secp256k1_ecdh.h>
#include <sodium/randombytes.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/un.h>
#include <unistd.h>
#include <wire/gen_peer_wire.h>
#include <wire/wire_io.h>
#include <wire/wire_sync.h>
/*~ A channel consists of a `struct half_chan` for each direction, each of
* which has a `flags` word from the `channel_update`; bit 1 is
* ROUTING_FLAGS_DISABLED in the `channel_update`. But we also keep a local
* whole-channel flag which indicates it's not available; we use this when a
* peer disconnects, and generate a `channel_update` to tell the world lazily
* when someone asks. */
static void peer_disable_channels(struct daemon *daemon, struct node *node)
{
/* If this peer had a channel with us, mark it disabled. */
struct chan_map_iter i;
struct chan *c;
for (c = first_chan(node, &i); c; c = next_chan(node, &i)) {
if (node_id_eq(&other_node(node, c)->id, &daemon->id))
local_disable_chan(daemon->rstate, c);
}
}
/*~ Destroy a peer, usually because the per-peer daemon has exited.
*
* Were you wondering why we call this "destroy_peer" and not "peer_destroy"?
* I thought not! But while CCAN modules are required to keep to their own
* prefix namespace, leading to unnatural word order, we couldn't stomach that
* for our own internal use. We use 'find_foo', 'destroy_foo' and 'new_foo'.
*/
static void destroy_peer(struct peer *peer)
{
struct node *node;
/* Remove it from the peers list */
list_del_from(&peer->daemon->peers, &peer->list);
/* If we have a channel with this peer, disable it. */
node = get_node(peer->daemon->rstate, &peer->id);
if (node)
peer_disable_channels(peer->daemon, node);
/* This is tricky: our lifetime is tied to the daemon_conn; it's our
* parent, so we are freed if it is, but we need to free it if we're
* freed manually. tal_free() treats this as a noop if it's already
* being freed */
tal_free(peer->dc);
}
/* Search for a peer. */
struct peer *find_peer(struct daemon *daemon, const struct node_id *id)
{
struct peer *peer;
list_for_each(&daemon->peers, peer, list)
if (node_id_eq(&peer->id, id))
return peer;
return NULL;
}
/* Increase a peer's gossip_counter, if peer not NULL */
void peer_supplied_good_gossip(struct peer *peer, size_t amount)
{
if (peer)
peer->gossip_counter += amount;
}
/* Queue a gossip message for the peer: the subdaemon on the other end simply
* forwards it to the peer. */
void queue_peer_msg(struct peer *peer, const u8 *msg TAKES)
{
daemon_conn_send(peer->dc, msg);
}
/*~ We have a helper for messages from the store. */
void queue_peer_from_store(struct peer *peer,
const struct broadcastable *bcast)
{
struct gossip_store *gs = peer->daemon->rstate->gs;
queue_peer_msg(peer, take(gossip_store_get(NULL, gs, bcast->index)));
}
/*~ We don't actually keep node_announcements in memory; we keep them in
* a file called `gossip_store`. If we need some node details, we reload
* and reparse. It's slow, but generally rare. */
static bool get_node_announcement(const tal_t *ctx,
struct daemon *daemon,
const struct node *n,
u8 rgb_color[3],
u8 alias[32],
u8 **features,
struct wireaddr **wireaddrs)
{
const u8 *msg;
struct node_id id;
secp256k1_ecdsa_signature signature;
u32 timestamp;
u8 *addresses;
if (!n->bcast.index)
return false;
msg = gossip_store_get(tmpctx, daemon->rstate->gs, n->bcast.index);
/* Note: validity of node_id is already checked. */
if (!fromwire_node_announcement(ctx, msg,
&signature, features,
×tamp,
&id, rgb_color, alias,
&addresses)) {
status_broken("Bad local node_announcement @%u: %s",
n->bcast.index, tal_hex(tmpctx, msg));
return false;
}
if (!node_id_eq(&id, &n->id) || timestamp != n->bcast.timestamp) {
status_broken("Wrong node_announcement @%u:"
" expected %s timestamp %u "
" got %s timestamp %u",
n->bcast.index,
type_to_string(tmpctx, struct node_id, &n->id),
timestamp,
type_to_string(tmpctx, struct node_id, &id),
n->bcast.timestamp);
return false;
}
*wireaddrs = read_addresses(ctx, addresses);
tal_free(addresses);
return true;
}
/* Version which also does nodeid lookup */
static bool get_node_announcement_by_id(const tal_t *ctx,
struct daemon *daemon,
const struct node_id *node_id,
u8 rgb_color[3],
u8 alias[32],
u8 **features,
struct wireaddr **wireaddrs)
{
struct node *n = get_node(daemon->rstate, node_id);
if (!n)
return false;
return get_node_announcement(ctx, daemon, n, rgb_color, alias,
features, wireaddrs);
}
/*~Routines to handle gossip messages from peer, forwarded by subdaemons.
*-----------------------------------------------------------------------
*
* It's not the subdaemon's fault if they're malformed or invalid; so these
* all return an error packet which gets sent back to the subdaemon in that
* case.
*/
/* The routing code checks that it's basically valid, returning an
* error message for the peer or NULL. NULL means it's OK, but the
* message might be redundant, in which case scid is also NULL.
* Otherwise `scid` gives us the short_channel_id claimed by the
* message, and puts the announcemnt on an internal 'pending'
* queue. We'll send a request to lightningd to look it up, and continue
* processing in `handle_txout_reply`. */
static const u8 *handle_channel_announcement_msg(struct peer *peer,
const u8 *msg)
{
const struct short_channel_id *scid;
const u8 *err;
/* If it's OK, tells us the short_channel_id to lookup; it notes
* if this is the unknown channel the peer was looking for (in
* which case, it frees and NULLs that ptr) */
err = handle_channel_announcement(peer->daemon->rstate, msg,
peer->daemon->current_blockheight,
&scid, peer);
if (err)
return err;
else if (scid) {
/* We give them some grace period, in case we don't know about
* block yet. */
if (peer->daemon->current_blockheight == 0
|| !is_scid_depth_announceable(scid,
peer->daemon->current_blockheight)) {
tal_arr_expand(&peer->daemon->deferred_txouts, *scid);
} else {
daemon_conn_send(peer->daemon->master,
take(towire_gossip_get_txout(NULL,
scid)));
}
}
return NULL;
}
static u8 *handle_channel_update_msg(struct peer *peer, const u8 *msg)
{
struct short_channel_id unknown_scid;
/* Hand the channel_update to the routing code */
u8 *err;
unknown_scid.u64 = 0;
err = handle_channel_update(peer->daemon->rstate, msg, peer,
&unknown_scid);
if (err) {
if (unknown_scid.u64 != 0)
query_unknown_channel(peer->daemon, peer, &unknown_scid);
return err;
}
/*~ As a nasty compromise in the spec, we only forward `channel_announce`
* once we have a `channel_update`; the channel isn't *usable* for
* routing until you have both anyway. For this reason, we might have
* just sent out our own channel_announce, so we check if it's time to
* send a node_announcement too. */
maybe_send_own_node_announce(peer->daemon);
return NULL;
}
/*~ When we compact the gossip store, all the broadcast indexs move.
* We simply offset everyone, which means in theory they could retransmit
* some, but that's a lesser evil than skipping some. */
void update_peers_broadcast_index(struct list_head *peers, u32 offset)
{
struct peer *peer, *next;
list_for_each_safe(peers, peer, next, list) {
int gs_fd;
/*~ Since store has been compacted, they need a new fd for the
* new store. We also tell them how much this is shrunk, so
* they can (approximately) tell where to start in the new store.
*/
gs_fd = gossip_store_readonly_fd(peer->daemon->rstate->gs);
if (gs_fd < 0) {
status_broken("Can't get read-only gossip store fd:"
" killing peer");
tal_free(peer);
} else {
u8 *msg = towire_gossipd_new_store_fd(NULL, offset);
daemon_conn_send(peer->dc, take(msg));
daemon_conn_send_fd(peer->dc, gs_fd);
}
}
}
/*~ For simplicity, all pings and pongs are forwarded to us here in gossipd. */
static u8 *handle_ping(struct peer *peer, const u8 *ping)
{
u8 *pong;
/* This checks the ping packet and makes a pong reply if needed; peer
* can specify it doesn't want a response, to simulate traffic. */
if (!check_ping_make_pong(NULL, ping, &pong))
return towire_errorfmt(peer, NULL, "Bad ping");
if (pong)
queue_peer_msg(peer, take(pong));
return NULL;
}
/*~ When we get a pong, we tell lightningd about it (it's probably a response
* to the `ping` JSON RPC command). */
static const u8 *handle_pong(struct peer *peer, const u8 *pong)
{
const char *err = got_pong(pong, &peer->num_pings_outstanding);
if (err)
return towire_errorfmt(peer, NULL, "%s", err);
daemon_conn_send(peer->daemon->master,
take(towire_gossip_ping_reply(NULL, &peer->id, true,
tal_count(pong))));
return NULL;
}
/*~ This is when channeld asks us for a channel_update for a local channel.
* It does that to fill in the error field when lightningd fails an HTLC and
* sets the UPDATE bit in the error type. lightningd is too important to
* fetch this itself, so channeld does it (channeld has to talk to us for
* other things anyway, so why not?). */
static bool handle_get_local_channel_update(struct peer *peer, const u8 *msg)
{
struct short_channel_id scid;
struct local_chan *local_chan;
struct chan *chan;
const u8 *update;
struct routing_state *rstate = peer->daemon->rstate;
if (!fromwire_gossipd_get_update(msg, &scid)) {
status_broken("peer %s sent bad gossip_get_update %s",
type_to_string(tmpctx, struct node_id, &peer->id),
tal_hex(tmpctx, msg));
return false;
}
/* It's possible that the channel has just closed (though v. unlikely) */
local_chan = local_chan_map_get(&rstate->local_chan_map, &scid);
if (!local_chan) {
status_unusual("peer %s scid %s: unknown channel",
type_to_string(tmpctx, struct node_id, &peer->id),
type_to_string(tmpctx, struct short_channel_id,
&scid));
update = NULL;
goto out;
}
chan = local_chan->chan;
/* Since we're going to send it out, make sure it's up-to-date. */
refresh_local_channel(peer->daemon, local_chan, false);
/* It's possible this is zero, if we've never sent a channel_update
* for that channel. */
if (!is_halfchan_defined(&chan->half[local_chan->direction]))
update = NULL;
else
update = gossip_store_get(tmpctx, rstate->gs,
chan->half[local_chan->direction].bcast.index);
out:
status_peer_debug(&peer->id, "schanid %s: %s update",
type_to_string(tmpctx, struct short_channel_id, &scid),
update ? "got" : "no");
msg = towire_gossipd_get_update_reply(NULL, update);
daemon_conn_send(peer->dc, take(msg));
return true;
}
static u8 *handle_node_announce(struct peer *peer, const u8 *msg)
{
bool was_unknown = false;
u8 *err;
err = handle_node_announcement(peer->daemon->rstate, msg, peer,
&was_unknown);
if (was_unknown)
query_unknown_node(peer->daemon->seeker, peer);
return err;
}
static bool handle_local_channel_announcement(struct daemon *daemon,
struct peer *peer,
const u8 *msg)
{
u8 *cannouncement;
const u8 *err;
if (!fromwire_gossipd_local_channel_announcement(msg, msg,
&cannouncement)) {
status_broken("peer %s bad local_channel_announcement %s",
type_to_string(tmpctx, struct node_id, &peer->id),
tal_hex(tmpctx, msg));
return false;
}
err = handle_channel_announcement_msg(peer, cannouncement);
if (err) {
status_broken("peer %s invalid local_channel_announcement %s (%s)",
type_to_string(tmpctx, struct node_id, &peer->id),
tal_hex(tmpctx, msg),
tal_hex(tmpctx, err));
return false;
}
return true;
}
/*~ This is where the per-peer daemons send us messages. It's either forwarded
* gossip, or a request for information. We deliberately use non-overlapping
* message types so we can distinguish them. */
static struct io_plan *peer_msg_in(struct io_conn *conn,
const u8 *msg,
struct peer *peer)
{
const u8 *err;
bool ok;
/* These are messages relayed from peer */
switch ((enum wire_type)fromwire_peektype(msg)) {
case WIRE_CHANNEL_ANNOUNCEMENT:
err = handle_channel_announcement_msg(peer, msg);
goto handled_relay;
case WIRE_CHANNEL_UPDATE:
err = handle_channel_update_msg(peer, msg);
goto handled_relay;
case WIRE_NODE_ANNOUNCEMENT:
err = handle_node_announce(peer, msg);
goto handled_relay;
case WIRE_QUERY_CHANNEL_RANGE:
err = handle_query_channel_range(peer, msg);
goto handled_relay;
case WIRE_REPLY_CHANNEL_RANGE:
err = handle_reply_channel_range(peer, msg);
goto handled_relay;
case WIRE_QUERY_SHORT_CHANNEL_IDS:
err = handle_query_short_channel_ids(peer, msg);
goto handled_relay;
case WIRE_REPLY_SHORT_CHANNEL_IDS_END:
err = handle_reply_short_channel_ids_end(peer, msg);
goto handled_relay;
case WIRE_PING:
err = handle_ping(peer, msg);
goto handled_relay;
case WIRE_PONG:
err = handle_pong(peer, msg);
goto handled_relay;
/* These are non-gossip messages (!is_msg_for_gossipd()) */
case WIRE_INIT:
case WIRE_ERROR:
case WIRE_OPEN_CHANNEL:
case WIRE_ACCEPT_CHANNEL:
case WIRE_FUNDING_CREATED:
case WIRE_FUNDING_SIGNED:
case WIRE_FUNDING_LOCKED:
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_COMMITMENT_SIGNED:
case WIRE_REVOKE_AND_ACK:
case WIRE_UPDATE_FEE:
case WIRE_CHANNEL_REESTABLISH:
case WIRE_ANNOUNCEMENT_SIGNATURES:
case WIRE_GOSSIP_TIMESTAMP_FILTER:
#if EXPERIMENTAL_FEATURES
case WIRE_ONION_MESSAGE:
#endif
status_broken("peer %s: relayed unexpected msg of type %s",
type_to_string(tmpctx, struct node_id, &peer->id),
wire_type_name(fromwire_peektype(msg)));
return io_close(conn);
}
/* Must be a gossip_peerd_wire_type asking us to do something. */
switch ((enum gossip_peerd_wire_type)fromwire_peektype(msg)) {
case WIRE_GOSSIPD_GET_UPDATE:
ok = handle_get_local_channel_update(peer, msg);
goto handled_cmd;
case WIRE_GOSSIPD_LOCAL_ADD_CHANNEL:
ok = handle_local_add_channel(peer->daemon->rstate, peer,
msg, 0);
goto handled_cmd;
case WIRE_GOSSIPD_LOCAL_CHANNEL_UPDATE:
ok = handle_local_channel_update(peer->daemon, &peer->id, msg);
goto handled_cmd;
case WIRE_GOSSIPD_LOCAL_CHANNEL_ANNOUNCEMENT:
ok = handle_local_channel_announcement(peer->daemon, peer, msg);
goto handled_cmd;
/* These are the ones we send, not them */
case WIRE_GOSSIPD_GET_UPDATE_REPLY:
case WIRE_GOSSIPD_NEW_STORE_FD:
break;
}
/* Anything else should not have been sent to us: close on it */
status_peer_broken(&peer->id, "unexpected cmd of type %i %s",
fromwire_peektype(msg),
gossip_peerd_wire_type_name(fromwire_peektype(msg)));
return io_close(conn);
/* Commands should always be OK. */
handled_cmd:
if (!ok)
return io_close(conn);
goto done;
/* Forwarded messages may be bad, so we have error which the per-peer
* daemon will forward to the peer. */
handled_relay:
if (err)
queue_peer_msg(peer, take(err));
done:
return daemon_conn_read_next(conn, peer->dc);
}
/*~ This is where connectd tells us about a new peer, and we hand back an fd for
* it to send us messages via peer_msg_in above */
static struct io_plan *connectd_new_peer(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
struct peer *peer = tal(conn, struct peer);
int fds[2];
int gossip_store_fd;
struct gossip_state *gs;
if (!fromwire_gossip_new_peer(msg, &peer->id,
&peer->gossip_queries_feature,
&peer->initial_routing_sync_feature)) {
status_broken("Bad new_peer msg from connectd: %s",
tal_hex(tmpctx, msg));
return io_close(conn);
}
gossip_store_fd = gossip_store_readonly_fd(daemon->rstate->gs);;
if (gossip_store_fd < 0) {
status_broken("Failed to get readonly store fd: %s",
strerror(errno));
daemon_conn_send(daemon->connectd,
take(towire_gossip_new_peer_reply(NULL,
false,
NULL)));
goto done;
}
/* This can happen: we handle it gracefully, returning a `failed` msg. */
if (socketpair(AF_LOCAL, SOCK_STREAM, 0, fds) != 0) {
status_broken("Failed to create socketpair: %s",
strerror(errno));
close(gossip_store_fd);
daemon_conn_send(daemon->connectd,
take(towire_gossip_new_peer_reply(NULL,
false,
NULL)));
goto done;
}
/* We might not have noticed old peer is dead; kill it now. */
tal_free(find_peer(daemon, &peer->id));
/* Populate the rest of the peer info. */
peer->daemon = daemon;
peer->gossip_counter = 0;
peer->scid_queries = NULL;
peer->scid_query_idx = 0;
peer->scid_query_nodes = NULL;
peer->scid_query_nodes_idx = 0;
peer->scid_query_outstanding = false;
peer->query_channel_blocks = NULL;
peer->query_channel_range_cb = NULL;
peer->num_pings_outstanding = 0;
/* We keep a list so we can find peer by id */
list_add_tail(&peer->daemon->peers, &peer->list);
tal_add_destructor(peer, destroy_peer);
/* This is the new connection: calls maybe_send_query_responses when
* nothing else to send. */
peer->dc = daemon_conn_new(daemon, fds[0],
peer_msg_in,
maybe_send_query_responses, peer);
/* Free peer if conn closed (destroy_peer closes conn if peer freed) */
tal_steal(peer->dc, peer);
/* This sends the initial timestamp filter. */
seeker_setup_peer_gossip(daemon->seeker, peer);
/* BOLT #7:
*
* A node:
* - if the `gossip_queries` feature is negotiated:
* - MUST NOT relay any gossip messages it did not generate itself,
* unless explicitly requested.
*/
if (peer->gossip_queries_feature) {
gs = NULL;
} else {
/* BOLT #7:
*
* - upon receiving an `init` message with the
* `initial_routing_sync` flag set to 1:
* - SHOULD send gossip messages for all known channels and
* nodes, as if they were just received.
* - if the `initial_routing_sync` flag is set to 0, OR if the
* initial sync was completed:
* - SHOULD resume normal operation, as specified in the
* following [Rebroadcasting](#rebroadcasting) section.
*/
gs = tal(tmpctx, struct gossip_state);
gs->timestamp_min = 0;
gs->timestamp_max = UINT32_MAX;
/* If they don't want initial sync, start at end of store */
if (!peer->initial_routing_sync_feature)
lseek(gossip_store_fd, 0, SEEK_END);
gs->next_gossip = time_mono();
}
/* Reply with success, and the new fd and gossip_state. */
daemon_conn_send(daemon->connectd,
take(towire_gossip_new_peer_reply(NULL, true, gs)));
daemon_conn_send_fd(daemon->connectd, fds[1]);
daemon_conn_send_fd(daemon->connectd, gossip_store_fd);
done:
return daemon_conn_read_next(conn, daemon->connectd);
}
/*~ connectd can also ask us if we know any addresses for a given id. */
static struct io_plan *connectd_get_address(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
struct node_id id;
u8 rgb_color[3];
u8 alias[32];
u8 *features;
struct wireaddr *addrs;
if (!fromwire_gossip_get_addrs(msg, &id)) {
status_broken("Bad gossip_get_addrs msg from connectd: %s",
tal_hex(tmpctx, msg));
return io_close(conn);
}
if (!get_node_announcement_by_id(tmpctx, daemon, &id,
rgb_color, alias, &features, &addrs))
addrs = NULL;
daemon_conn_send(daemon->connectd,
take(towire_gossip_get_addrs_reply(NULL, addrs)));
return daemon_conn_read_next(conn, daemon->connectd);
}
/*~ connectd's input handler is very simple. */
static struct io_plan *connectd_req(struct io_conn *conn,
const u8 *msg,
struct daemon *daemon)
{
enum connect_gossip_wire_type t = fromwire_peektype(msg);
switch (t) {
case WIRE_GOSSIP_NEW_PEER:
return connectd_new_peer(conn, daemon, msg);
case WIRE_GOSSIP_GET_ADDRS:
return connectd_get_address(conn, daemon, msg);
/* We send these, don't receive them. */
case WIRE_GOSSIP_NEW_PEER_REPLY:
case WIRE_GOSSIP_GET_ADDRS_REPLY:
break;
}
status_broken("Bad msg from connectd: %s",
tal_hex(tmpctx, msg));
return io_close(conn);
}
/*~ This is our 13-day timer callback for refreshing our channels. This
* was added to the spec because people abandoned their channels without
* closing them. */
static void gossip_send_keepalive_update(struct daemon *daemon,
struct local_chan *local_chan)
{
status_debug("Sending keepalive channel_update for %s/%u",
type_to_string(tmpctx, struct short_channel_id,
&local_chan->chan->scid),
local_chan->direction);
/* As a side-effect, this will create an update which matches the
* local_disabled state */
refresh_local_channel(daemon, local_chan, true);
}
/* BOLT #7:
*
* A node:
* - if a channel's latest `channel_update`s `timestamp` is older than two weeks
* (1209600 seconds):
* - MAY prune the channel.
* - MAY ignore the channel.
*/
static void gossip_refresh_network(struct daemon *daemon)
{
u64 now = gossip_time_now(daemon->rstate).ts.tv_sec;
s64 highwater;
struct node *n;
/* Send out 1 day before deadline */
highwater = now - (GOSSIP_PRUNE_INTERVAL(daemon->rstate->dev_fast_gossip)
- GOSSIP_BEFORE_DEADLINE(daemon->rstate->dev_fast_gossip_prune));
/* Schedule next run now */
notleak(new_reltimer(&daemon->timers, daemon,
time_from_sec(GOSSIP_PRUNE_INTERVAL(daemon->rstate->dev_fast_gossip_prune)/4),
gossip_refresh_network, daemon));
/* Find myself in the network */
n = get_node(daemon->rstate, &daemon->id);
if (n) {
/* Iterate through all outgoing connection and check whether
* it's time to re-announce */
struct chan_map_iter i;
struct chan *c;
for (c = first_chan(n, &i); c; c = next_chan(n, &i)) {
struct local_chan *local_chan;
struct half_chan *hc;
local_chan = is_local_chan(daemon->rstate, c);
hc = &c->half[local_chan->direction];
if (!is_halfchan_defined(hc)) {
/* Connection is not announced yet, so don't even
* try to re-announce it */
continue;
}
if (hc->bcast.timestamp > highwater) {
/* No need to send a keepalive update message */
continue;
}
if (!is_halfchan_enabled(hc)) {
/* Only send keepalives for active connections */
continue;
}
gossip_send_keepalive_update(daemon, local_chan);
}
}
/* Now we've refreshed our channels, we can prune without clobbering
* them */
route_prune(daemon->rstate);
}
/* Disables all channels connected to our node. */
static void gossip_disable_local_channels(struct daemon *daemon)
{
struct node *local_node = get_node(daemon->rstate, &daemon->id);
struct chan_map_iter i;
struct chan *c;
/* We don't have a local_node, so we don't have any channels yet
* either */
if (!local_node)
return;
for (c = first_chan(local_node, &i); c; c = next_chan(local_node, &i))
local_disable_chan(daemon->rstate, c);
}
struct peer *random_peer(struct daemon *daemon,
bool (*check_peer)(const struct peer *peer))
{
u64 target = UINT64_MAX;
struct peer *best = NULL, *i;
/* Reservoir sampling */
list_for_each(&daemon->peers, i, list) {
u64 r;
if (!check_peer(i))
continue;
r = pseudorand_u64();
if (r <= target) {
best = i;
target = r;
}
}
return best;
}
/*~ Parse init message from lightningd: starts the daemon properly. */
static struct io_plan *gossip_init(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
u32 *dev_gossip_time;
bool dev_fast_gossip, dev_fast_gossip_prune;
u32 timestamp;
if (!fromwire_gossipctl_init(daemon, msg,
&chainparams,
&daemon->our_features,
&daemon->id,
daemon->rgb,
daemon->alias,
&daemon->announcable,
&dev_gossip_time,
&dev_fast_gossip,
&dev_fast_gossip_prune)) {
master_badmsg(WIRE_GOSSIPCTL_INIT, msg);
}
daemon->rstate = new_routing_state(daemon,
&daemon->id,
&daemon->peers,
&daemon->timers,
take(dev_gossip_time),
dev_fast_gossip,
dev_fast_gossip_prune);
/* Load stored gossip messages, get last modified time of file */
timestamp = gossip_store_load(daemon->rstate, daemon->rstate->gs);
/* If last_timestamp was > modified time of file, reduce it.
* Usually it's capped to "now", but in the reload case it needs to
* be the gossip_store mtime. */
if (daemon->rstate->last_timestamp > timestamp)
daemon->rstate->last_timestamp = timestamp;
/* Now disable all local channels, they can't be connected yet. */
gossip_disable_local_channels(daemon);
/* If that announced channels, we can announce ourselves (options
* or addresses might have changed!) */
maybe_send_own_node_announce(daemon);
/* Start the twice- weekly refresh timer. */
notleak(new_reltimer(&daemon->timers, daemon,
time_from_sec(GOSSIP_PRUNE_INTERVAL(daemon->rstate->dev_fast_gossip_prune) / 4),
gossip_refresh_network, daemon));
/* Fire up the seeker! */
daemon->seeker = new_seeker(daemon);
return daemon_conn_read_next(conn, daemon->master);
}
/*~ lightningd can ask for a route between nodes. */
static struct io_plan *getroute_req(struct io_conn *conn, struct daemon *daemon,
const u8 *msg)
{
struct node_id *source, destination;
struct amount_msat msat;
u32 final_cltv;
/* risk factor 12.345% -> riskfactor_millionths = 12345000 */
u64 riskfactor_millionths;
u32 max_hops;
u8 *out;
struct route_hop **hops;
/* fuzz 12.345% -> fuzz_millionths = 12345000 */
u64 fuzz_millionths;
struct exclude_entry **excluded;
/* To choose between variations, we need to know how much we're
* sending (eliminates too-small channels, and also effects the fees
* we'll pay), how to trade off more locktime vs. more fees, and how
* much cltv we need a the final node to give exact values for each
* intermediate hop, as well as how much random fuzz to inject to
* avoid being too predictable.
*
* We also treat routing slightly differently if we're asking
* for a route from ourselves (the usual case): in that case,
* we don't have to consider fees on our own outgoing channels.
*/
if (!fromwire_gossip_getroute_request(
msg, msg, &source, &destination, &msat, &riskfactor_millionths,
&final_cltv, &fuzz_millionths, &excluded, &max_hops))
master_badmsg(WIRE_GOSSIP_GETROUTE_REQUEST, msg);
status_debug("Trying to find a route from %s to %s for %s",
source
? type_to_string(tmpctx, struct node_id, source) : "(me)",
type_to_string(tmpctx, struct node_id, &destination),
type_to_string(tmpctx, struct amount_msat, &msat));
/* routing.c does all the hard work; can return NULL. */
hops = get_route(tmpctx, daemon->rstate, source, &destination, msat,
riskfactor_millionths / 1000000.0, final_cltv,
fuzz_millionths / 1000000.0, pseudorand_u64(),
excluded, max_hops);
out = towire_gossip_getroute_reply(NULL,
cast_const2(const struct route_hop **,
hops));
daemon_conn_send(daemon->master, take(out));
return daemon_conn_read_next(conn, daemon->master);
}
/*~ When someone asks lightningd to `listchannels`, gossipd does the work:
* marshalling the channel information for all channels into an array of
* gossip_getchannels_entry, which lightningd converts to JSON. Each channel
* is represented by two half_chan; one in each direction.
*/
static struct gossip_halfchannel_entry *hc_entry(const tal_t *ctx,
const struct chan *chan,
int idx)
{
/* Our 'struct chan' contains two nodes: they are in pubkey_cmp order
* (ie. chan->nodes[0] is the lesser pubkey) and this is the same as
* the direction bit in `channel_update`s `channel_flags`.
*
* The halfchans are arranged so that half[0] src == nodes[0], and we
* use that here. */
const struct half_chan *c = &chan->half[idx];
struct gossip_halfchannel_entry *e;
/* If we've never seen a channel_update for this direction... */
if (!is_halfchan_defined(c))
return NULL;
e = tal(ctx, struct gossip_halfchannel_entry);
e->channel_flags = c->channel_flags;
e->message_flags = c->message_flags;
e->last_update_timestamp = c->bcast.timestamp;
e->base_fee_msat = c->base_fee;
e->fee_per_millionth = c->proportional_fee;
e->delay = c->delay;
e->min = c->htlc_minimum;
e->max = c->htlc_maximum;
return e;
}
/*~ We don't keep channel features in memory; they're rarely used. So we
* remember if it exists, and load it off disk when needed. */
static u8 *get_channel_features(const tal_t *ctx,
struct gossip_store *gs,
const struct chan *chan)
{
secp256k1_ecdsa_signature sig;
u8 *features;
struct bitcoin_blkid chain_hash;
struct short_channel_id short_channel_id;
struct node_id node_id;
struct pubkey bitcoin_key;
struct amount_sat sats;
const u8 *ann;
/* This is where we stash a flag to indicate it exists. */
if (!chan->half[0].any_features)
return NULL;
/* Could be a channel_announcement, could be a local_add_channel */
ann = gossip_store_get(tmpctx, gs, chan->bcast.index);
if (!fromwire_channel_announcement(ctx, ann, &sig, &sig, &sig, &sig,
&features, &chain_hash,
&short_channel_id,
&node_id, &node_id,
&bitcoin_key, &bitcoin_key)
&& !fromwire_gossipd_local_add_channel(ctx, ann, &short_channel_id,
&node_id, &sats, &features))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"bad channel_announcement / local_add_channel at %u: %s",
chan->bcast.index, tal_hex(tmpctx, ann));