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core-lightning/gossipd/gossipd.c
Rusty Russell 4cfd0524eb gossipd: simplify duplicate node_announcement check. 
Write helpers to split it into non-timestamp, non-signature parts,
and simply compare those.  We extract a helper to do channel_update, too.

This is more generic than our previous approach, and simpler.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2019-09-20 06:55:00 +00:00

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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/asort/asort.h>
#include <ccan/bitmap/bitmap.h>
#include <ccan/build_assert/build_assert.h>
#include <ccan/cast/cast.h>
#include <ccan/container_of/container_of.h>
#include <ccan/crc32c/crc32c.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/list/list.h>
#include <ccan/mem/mem.h>
#include <ccan/noerr/noerr.h>
#include <ccan/take/take.h>
#include <ccan/tal/str/str.h>
#include <ccan/timer/timer.h>
#include <common/bech32.h>
#include <common/bech32_util.h>
#include <common/cryptomsg.h>
#include <common/daemon_conn.h>
#include <common/decode_short_channel_ids.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/routing.h>
#include <hsmd/gen_hsm_wire.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>
#include <zlib.h>
/* We talk to `hsmd` to sign our gossip messages with the node key */
#define HSM_FD 3
/* connectd asks us for help finding nodes, and gossip fds for new peers */
#define CONNECTD_FD 4
/* In developer mode we provide hooks for whitebox testing */
#if DEVELOPER
static u32 max_encoding_bytes = -1U;
static bool suppress_gossip = false;
#endif
#if EXPERIMENTAL_FEATURES == 0
/* We want these definitions for convenience, even if we never encode/decode
* them when not EXPERIMENTAL_FEATURES */
struct tlv_reply_channel_range_tlvs_timestamps_tlv {
u8 encoding_type;
u8 *encoded_timestamps;
};
struct tlv_reply_channel_range_tlvs_checksums_tlv {
struct channel_update_checksums *checksums;
};
struct channel_update_timestamps {
u32 timestamp_node_id_1;
u32 timestamp_node_id_2;
};
struct channel_update_checksums {
u32 checksum_node_id_1;
u32 checksum_node_id_2;
};
static void towire_channel_update_timestamps(u8 **p,
const struct channel_update_timestamps *channel_update_timestamps)
{
abort();
}
#endif
/*~ The core daemon structure: */
struct daemon {
/* Who am I? Helps us find ourself in the routing map. */
struct node_id id;
/* Peers we are gossiping to: id is unique */
struct list_head peers;
/* Connection to lightningd. */
struct daemon_conn *master;
/* Connection to connect daemon. */
struct daemon_conn *connectd;
/* Routing information */
struct routing_state *rstate;
/* chainhash for checking/making gossip msgs */
struct bitcoin_blkid chain_hash;
/* Timers: we batch gossip, and also refresh announcements */
struct timers timers;
/* Global features to list in node_announcement. */
u8 *globalfeatures;
/* Alias (not NUL terminated) and favorite color for node_announcement */
u8 alias[32];
u8 rgb[3];
/* What addresses we can actually announce. */
struct wireaddr *announcable;
/* Do we think we're missing gossip? Contains timer to re-check */
struct oneshot *gossip_missing;
/* Channels we've heard about, but don't know. */
struct short_channel_id *unknown_scids;
};
/*~ How gossipy do we ask a peer to be? */
enum gossip_level {
/* Give us everything since epoch */
GOSSIP_HIGH,
/* Give us everything from 24 hours ago. */
GOSSIP_MEDIUM,
/* Give us everything from now. */
GOSSIP_LOW,
/* Give us nothing. */
GOSSIP_NONE,
};
/* What are our targets for each gossip level? (including levels above).
*
* If we're missing gossip: 3 high.
* Otherwise, 2 medium, and 8 low. Rest no limit..
*/
static const size_t gossip_level_targets[] = { 3, 2, 8, SIZE_MAX };
/* This represents each peer we're gossiping with */
struct peer {
/* daemon->peers */
struct list_node list;
/* parent pointer. */
struct daemon *daemon;
/* The ID of the peer (always unique) */
struct node_id id;
/* The two features gossip cares about (so far) */
bool gossip_queries_feature, initial_routing_sync_feature;
/* Are there outstanding responses for queries on short_channel_ids? */
const struct short_channel_id *scid_queries;
const bigsize_t *scid_query_flags;
size_t scid_query_idx;
/* Are there outstanding node_announcements from scid_queries? */
struct node_id *scid_query_nodes;
size_t scid_query_nodes_idx;
/* Do we have an scid_query outstanding? Was it internal? */
bool scid_query_outstanding;
bool scid_query_was_internal;
/* How many pongs are we expecting? */
size_t num_pings_outstanding;
/* Map of outstanding channel_range requests. */
bitmap *query_channel_blocks;
/* What we're querying: [range_first_blocknum, range_end_blocknum) */
u32 range_first_blocknum, range_end_blocknum;
u32 range_blocks_remaining;
struct short_channel_id *query_channel_scids;
/* Are we asking this peer to give us lot of gossip? */
enum gossip_level gossip_level;
/* The daemon_conn used to queue messages to/from the peer. */
struct daemon_conn *dc;
};
/*~ 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. */
static 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;
}
/* Queue a gossip message for the peer: the subdaemon on the other end simply
* forwards it to the peer. */
static 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. */
static 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)));
}
/* BOLT #7:
*
* There are several messages which contain a long array of
* `short_channel_id`s (called `encoded_short_ids`) so we utilize a
* simple compression scheme: the first byte indicates the encoding, the
* rest contains the data.
*/
static u8 *encoding_start(const tal_t *ctx)
{
return tal_arr(ctx, u8, 0);
}
/* Marshal a single short_channel_id */
static void encoding_add_short_channel_id(u8 **encoded,
const struct short_channel_id *scid)
{
towire_short_channel_id(encoded, scid);
}
/* Marshal a single channel_update_timestamps */
static void encoding_add_timestamps(u8 **encoded,
const struct channel_update_timestamps *ts)
{
towire_channel_update_timestamps(encoded, ts);
}
/* Marshal a single query flag (we don't query, so not currently used) */
static UNNEEDED void encoding_add_query_flag(u8 **encoded, bigsize_t flag)
{
towire_bigsize(encoded, flag);
}
/* Greg Maxwell asked me privately about using zlib for communicating a set,
* and suggested that we'd be better off using Golomb-Rice coding a-la BIP
* 158. However, naively using Rice encoding isn't a win: we have to get
* more complex and use separate streams. The upside is that it's between
* 2 and 5 times smaller (assuming optimal Rice encoding + gzip). We can add
* that later. */
static u8 *zencode(const tal_t *ctx, const u8 *scids, size_t len)
{
u8 *z;
int err;
unsigned long compressed_len = len;
#ifdef ZLIB_EVEN_IF_EXPANDS
/* Needed for test vectors */
compressed_len = 128 * 1024;
#endif
/* Prefer to fail if zlib makes it larger */
z = tal_arr(ctx, u8, compressed_len);
err = compress2(z, &compressed_len, scids, len, Z_DEFAULT_COMPRESSION);
if (err == Z_OK) {
status_debug("compressed %zu into %lu",
len, compressed_len);
tal_resize(&z, compressed_len);
return z;
}
status_debug("compress %zu returned %i:"
" not compresssing", len, err);
return NULL;
}
/* Try compressing *encoded: fails if result would be longer.
* @off is offset to place result in *encoded.
*/
static bool encoding_end_zlib(u8 **encoded, size_t off)
{
u8 *z;
size_t len = tal_count(*encoded);
z = zencode(tmpctx, *encoded, len);
if (!z)
return false;
/* Successful: copy over and trim */
tal_resize(encoded, off + tal_count(z));
memcpy(*encoded + off, z, tal_count(z));
tal_free(z);
return true;
}
static void encoding_end_no_compress(u8 **encoded, size_t off)
{
size_t len = tal_count(*encoded);
tal_resize(encoded, off + len);
memmove(*encoded + off, *encoded, len);
}
/* Once we've assembled it, try compressing.
* Prepends encoding type to @encoding. */
static bool encoding_end_prepend_type(u8 **encoded, size_t max_bytes)
{
if (encoding_end_zlib(encoded, 1))
**encoded = SHORTIDS_ZLIB;
else {
encoding_end_no_compress(encoded, 1);
**encoded = SHORTIDS_UNCOMPRESSED;
}
#if DEVELOPER
if (tal_count(*encoded) > max_encoding_bytes)
return false;
#endif
return tal_count(*encoded) <= max_bytes;
}
/* Try compressing, leaving type external */
static UNNEEDED bool encoding_end_external_type(u8 **encoded, u8 *type, size_t max_bytes)
{
if (encoding_end_zlib(encoded, 0))
*type = SHORTIDS_ZLIB;
else {
encoding_end_no_compress(encoded, 0);
*type = SHORTIDS_UNCOMPRESSED;
}
return tal_count(*encoded) <= max_bytes;
}
/*~ We have different levels of gossipiness, depending on our needs. */
static u32 gossip_start(const struct routing_state *rstate,
enum gossip_level gossip_level)
{
switch (gossip_level) {
case GOSSIP_HIGH:
return 0;
case GOSSIP_MEDIUM:
return gossip_time_now(rstate).ts.tv_sec - 24 * 3600;
case GOSSIP_LOW:
return gossip_time_now(rstate).ts.tv_sec;
case GOSSIP_NONE:
return UINT32_MAX;
}
abort();
}
/* BOLT #7:
*
* A node:
* - if the `gossip_queries` feature is negotiated:
* - MUST NOT relay any gossip messages unless explicitly requested.
*/
static void setup_gossip_range(struct peer *peer)
{
u8 *msg;
/*~ Without the `gossip_queries` feature, gossip flows automatically. */
if (!peer->gossip_queries_feature) {
/* This peer is gossipy whether we want it or not! */
return;
}
status_debug("Setting peer %s to gossip level %s",
type_to_string(tmpctx, struct node_id, &peer->id),
peer->gossip_level == GOSSIP_HIGH ? "HIGH"
: peer->gossip_level == GOSSIP_MEDIUM ? "MEDIUM"
: peer->gossip_level == GOSSIP_LOW ? "LOW"
: peer->gossip_level == GOSSIP_NONE ? "NONE"
: "INVALID");
/*~ We need to ask for something to start the gossip flowing. */
msg = towire_gossip_timestamp_filter(peer,
&peer->daemon->chain_hash,
gossip_start(peer->daemon->rstate,
peer->gossip_level),
UINT32_MAX);
queue_peer_msg(peer, take(msg));
}
/*~ Create a node_announcement with the given signature. It may be NULL in the
* case we need to create a provisional announcement for the HSM to sign.
* This is called twice: once with the dummy signature to get it signed and a
* second time to build the full packet with the signature. The timestamp is
* handed in rather than using time_now() internally, since that could change
* between the dummy creation and the call with a signature. */
static u8 *create_node_announcement(const tal_t *ctx, struct daemon *daemon,
const secp256k1_ecdsa_signature *sig,
u32 timestamp)
{
u8 *addresses = tal_arr(tmpctx, u8, 0);
u8 *announcement;
size_t i;
if (!sig)
sig = talz(tmpctx, secp256k1_ecdsa_signature);
for (i = 0; i < tal_count(daemon->announcable); i++)
towire_wireaddr(&addresses, &daemon->announcable[i]);
announcement =
towire_node_announcement(ctx, sig, daemon->globalfeatures, timestamp,
&daemon->id, daemon->rgb, daemon->alias,
addresses);
return announcement;
}
/* Helper to get non-signature, non-timestamp parts of (valid!) channel_update */
static void get_cupdate_parts(const u8 *channel_update,
const u8 *parts[2],
size_t sizes[2])
{
/* BOLT #7:
*
* 1. type: 258 (`channel_update`)
* 2. data:
* * [`signature`:`signature`]
* * [`chain_hash`:`chain_hash`]
* * [`short_channel_id`:`short_channel_id`]
* * [`u32`:`timestamp`]
*...
*/
/* Note: 2 bytes for `type` field */
/* We already checked it's valid before accepting */
assert(tal_count(channel_update) > 2 + 64 + 32 + 8 + 4);
parts[0] = channel_update + 2 + 64;
sizes[0] = 32 + 8;
parts[1] = channel_update + 2 + 64 + 32 + 8 + 4;
sizes[1] = tal_count(channel_update) - (64 + 2 + 32 + 8 + 4);
}
/* Get non-signature, non-timestamp parts of (valid!) node_announcement */
static void get_nannounce_parts(const u8 *node_announcement,
const u8 *parts[2],
size_t sizes[2])
{
size_t len;
const u8 *flen;
/* BOLT #7:
*
* 1. type: 257 (`node_announcement`)
* 2. data:
* * [`signature`:`signature`]
* * [`u16`:`flen`]
* * [`flen*byte`:`features`]
* * [`u32`:`timestamp`]
*...
*/
/* Note: 2 bytes for `type` field */
/* We already checked it's valid before accepting */
assert(tal_count(node_announcement) > 2 + 64);
parts[0] = node_announcement + 2 + 64;
/* Read flen to get size */
flen = parts[0];
len = tal_count(node_announcement) - (2 + 64);
sizes[0] = 2 + fromwire_u16(&flen, &len);
assert(flen != NULL && len >= 4);
parts[1] = node_announcement + 2 + 64 + sizes[0] + 4;
sizes[1] = tal_count(node_announcement) - (2 + 64 + sizes[0] + 4);
}
/*~ Is this node_announcement different from prev (not sigs and timestamps)? */
static bool nannounce_different(struct gossip_store *gs,
const struct node *node,
const u8 *nannounce)
{
const u8 *oparts[2], *nparts[2];
size_t osizes[2], nsizes[2];
const u8 *orig;
/* Get last one we have. */
orig = gossip_store_get(tmpctx, gs, node->bcast.index);
get_nannounce_parts(orig, oparts, osizes);
get_nannounce_parts(nannounce, nparts, nsizes);
return !memeq(oparts[0], osizes[0], nparts[0], nsizes[0])
|| !memeq(oparts[1], osizes[1], nparts[1], nsizes[1]);
}
/*~ This routine created a `node_announcement` for our node, and hands it to
* the routing.c code like any other `node_announcement`. Such announcements
* are only accepted if there is an announced channel associated with that node
* (to prevent spam), so we only call this once we've announced a channel. */
static void update_own_node_announcement(struct daemon *daemon)
{
u32 timestamp = gossip_time_now(daemon->rstate).ts.tv_sec;
secp256k1_ecdsa_signature sig;
u8 *msg, *nannounce, *err;
struct node *self = get_node(daemon->rstate, &daemon->id);
/* BOLT #7:
*
* The origin node:
* - MUST set `timestamp` to be greater than that of any previous
* `node_announcement` it has previously created.
*/
if (self && self->bcast.index && timestamp <= self->bcast.timestamp)
timestamp = self->bcast.timestamp + 1;
/* Make unsigned announcement. */
nannounce = create_node_announcement(tmpctx, daemon, NULL, timestamp);
/* If it's the same as the previous, nothing to do. */
if (self && self->bcast.index) {
if (!nannounce_different(daemon->rstate->gs, self, nannounce))
return;
}
/* Ask hsmd to sign it (synchronous) */
if (!wire_sync_write(HSM_FD, take(towire_hsm_node_announcement_sig_req(NULL, nannounce))))
status_failed(STATUS_FAIL_MASTER_IO, "Could not write to HSM: %s", strerror(errno));
msg = wire_sync_read(tmpctx, HSM_FD);
if (!fromwire_hsm_node_announcement_sig_reply(msg, &sig))
status_failed(STATUS_FAIL_MASTER_IO, "HSM returned an invalid node_announcement sig");
/* We got the signature for our provisional node_announcement back
* from the HSM, create the real announcement and forward it to
* gossipd so it can take care of forwarding it. */
nannounce = create_node_announcement(NULL, daemon, &sig, timestamp);
/* This injects it into the routing code in routing.c; it should not
* reject it! */
err = handle_node_announcement(daemon->rstate, take(nannounce));
if (err)
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"rejected own node announcement: %s",
tal_hex(tmpctx, err));
}
/*~ 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,
&timestamp,
&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);
}
/* Should we announce our own node? Called at strategic places. */
static void maybe_send_own_node_announce(struct daemon *daemon)
{
/* We keep an internal flag in the routing code to say we've announced
* a local channel. The alternative would be to have it make a
* callback, but when we start up we don't want to make multiple
* announcments, so we use this approach for now. */
if (!daemon->rstate->local_channel_announced)
return;
update_own_node_announcement(daemon);
daemon->rstate->local_channel_announced = false;
}
/* Query this peer for these short-channel-ids. */
static bool query_short_channel_ids(struct daemon *daemon,
struct peer *peer,
const struct short_channel_id *scids,
bool internal)
{
u8 *encoded, *msg;
/* BOLT #7:
*
* 1. type: 261 (`query_short_channel_ids`) (`gossip_queries`)
* 2. data:
* * [`chain_hash`:`chain_hash`]
* * [`u16`:`len`]
* * [`len*byte`:`encoded_short_ids`]
*/
const size_t reply_overhead = 32 + 2;
const size_t max_encoded_bytes = 65535 - 2 - reply_overhead;
/* Can't query if they don't have gossip_queries_feature */
if (!peer->gossip_queries_feature)
return false;
/* BOLT #7:
*
* The sender:
* - MUST NOT send `query_short_channel_ids` if it has sent a previous
* `query_short_channel_ids` to this peer and not received
* `reply_short_channel_ids_end`.
*/
if (peer->scid_query_outstanding)
return false;
encoded = encoding_start(tmpctx);
for (size_t i = 0; i < tal_count(scids); i++)
encoding_add_short_channel_id(&encoded, &scids[i]);
if (!encoding_end_prepend_type(&encoded, max_encoded_bytes)) {
status_broken("query_short_channel_ids: %zu is too many",
tal_count(scids));
return false;
}
#if EXPERIMENTAL_FEATURES
msg = towire_query_short_channel_ids(NULL, &daemon->chain_hash,
encoded, NULL);
#else
msg = towire_query_short_channel_ids(NULL, &daemon->chain_hash,
encoded);
#endif
queue_peer_msg(peer, take(msg));
peer->scid_query_outstanding = true;
peer->scid_query_was_internal = internal;
status_debug("%s: sending query for %zu scids",
type_to_string(tmpctx, struct node_id, &peer->id),
tal_count(scids));
return true;
}
/*~ This peer told us about an update to an unknown channel. Ask it for
* a channel_announcement. */
static void query_unknown_channel(struct daemon *daemon,
struct peer *peer,
const struct short_channel_id *id)
{
/* Don't go overboard if we're already asking for a lot. */
if (tal_count(daemon->unknown_scids) > 1000)
return;
/* Check we're not already getting this one. */
for (size_t i = 0; i < tal_count(daemon->unknown_scids); i++)
if (short_channel_id_eq(&daemon->unknown_scids[i], id))
return;
tal_arr_expand(&daemon->unknown_scids, *id);
/* This is best effort: if peer is busy, we'll try next time. */
query_short_channel_ids(daemon, peer, daemon->unknown_scids, true);
}
/*~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, &scid);
if (err)
return err;
else if (scid)
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, "subdaemon",
&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;
}
/*~ The peer can ask about an array of short channel ids: we don't assemble the
* reply immediately but process them one at a time in dump_gossip which is
* called when there's nothing more important to send. */
static const u8 *handle_query_short_channel_ids(struct peer *peer, const u8 *msg)
{
struct bitcoin_blkid chain;
u8 *encoded;
struct short_channel_id *scids;
bigsize_t *flags;
#if EXPERIMENTAL_FEATURES
struct tlv_query_short_channel_ids_tlvs *tlvs
= tlv_query_short_channel_ids_tlvs_new(tmpctx);
if (!fromwire_query_short_channel_ids(tmpctx, msg, &chain, &encoded,
tlvs)) {
return towire_errorfmt(peer, NULL,
"Bad query_short_channel_ids w/tlvs %s",
tal_hex(tmpctx, msg));
}
if (tlvs->query_flags) {
flags = decode_scid_query_flags(tmpctx, tlvs->query_flags);
if (!flags) {
return towire_errorfmt(peer, NULL,
"Bad query_short_channel_ids query_flags %s",
tal_hex(tmpctx, msg));
}
} else
flags = NULL;
#else
if (!fromwire_query_short_channel_ids(tmpctx, msg, &chain, &encoded)) {
return towire_errorfmt(peer, NULL,
"Bad query_short_channel_ids %s",
tal_hex(tmpctx, msg));
}
flags = NULL;
#endif
if (!bitcoin_blkid_eq(&peer->daemon->chain_hash, &chain)) {
status_debug("%s sent query_short_channel_ids chainhash %s",
type_to_string(tmpctx, struct node_id, &peer->id),
type_to_string(tmpctx, struct bitcoin_blkid, &chain));
return NULL;
}
/* BOLT #7:
*
* - if it has not sent `reply_short_channel_ids_end` to a
* previously received `query_short_channel_ids` from this
* sender:
* - MAY fail the connection.
*/
if (peer->scid_queries || peer->scid_query_nodes) {
return towire_errorfmt(peer, NULL,
"Bad concurrent query_short_channel_ids");
}
scids = decode_short_ids(tmpctx, encoded);
if (!scids) {
return towire_errorfmt(peer, NULL,
"Bad query_short_channel_ids encoding %s",
tal_hex(tmpctx, encoded));
}
/* BOLT-61a1365a45cc8b463ddbbe3429d350f8eac787dd #7:
*
* The receiver:
*...
* - if the incoming message includes `query_short_channel_ids_tlvs`:
* - if `encoded_query_flags` does not decode to exactly one flag per
* `short_channel_id`:
* - MAY fail the connection.
*/
if (!flags) {
/* Pretend they asked for everything. */
flags = tal_arr(tmpctx, bigsize_t, tal_count(scids));
memset(flags, 0xFF, tal_bytelen(flags));
} else {
if (tal_count(flags) != tal_count(scids)) {
return towire_errorfmt(peer, NULL,
"Bad query_short_channel_ids flags count %zu scids %zu",
tal_count(flags), tal_count(scids));
}
}
/* BOLT #7:
*
* - MUST respond to each known `short_channel_id` with a `channel_announcement`
* and the latest `channel_update` for each end
* - SHOULD NOT wait for the next outgoing gossip flush to send
* these.
*/
peer->scid_queries = tal_steal(peer, scids);
peer->scid_query_flags = tal_steal(peer, flags);
peer->scid_query_idx = 0;
peer->scid_query_nodes = tal_arr(peer, struct node_id, 0);
/* Notify the daemon_conn-write loop to invoke create_next_scid_reply */
daemon_conn_wake(peer->dc);
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);
}
}
}
/*~ We can send multiple replies when the peer queries for all channels in
* a given range of blocks; each one indicates the range of blocks it covers. */
static void reply_channel_range(struct peer *peer,
u32 first_blocknum, u32 number_of_blocks,
const u8 *encoded_scids,
struct tlv_reply_channel_range_tlvs_timestamps_tlv *timestamps,
struct tlv_reply_channel_range_tlvs_checksums_tlv *checksums)
{
/* BOLT #7:
*
* - For each `reply_channel_range`:
* - MUST set with `chain_hash` equal to that of `query_channel_range`,
* - MUST encode a `short_channel_id` for every open channel it
* knows in blocks `first_blocknum` to `first_blocknum` plus
* `number_of_blocks` minus one.
* - MUST limit `number_of_blocks` to the maximum number of blocks
* whose results could fit in `encoded_short_ids`
* - if does not maintain up-to-date channel information for
* `chain_hash`:
* - MUST set `complete` to 0.
* - otherwise:
* - SHOULD set `complete` to 1.
*/
#if EXPERIMENTAL_FEATURES
struct tlv_reply_channel_range_tlvs *tlvs
= tlv_reply_channel_range_tlvs_new(tmpctx);
tlvs->timestamps_tlv = timestamps;
tlvs->checksums_tlv = checksums;
u8 *msg = towire_reply_channel_range(NULL,
&peer->daemon->chain_hash,
first_blocknum,
number_of_blocks,
1, encoded_scids, tlvs);
#else
u8 *msg = towire_reply_channel_range(NULL,
&peer->daemon->chain_hash,
first_blocknum,
number_of_blocks,
1, encoded_scids);
#endif
queue_peer_msg(peer, take(msg));
}
/* BOLT-61a1365a45cc8b463ddbbe3429d350f8eac787dd #7:
*
* `query_option_flags` is a bitfield represented as a minimally-encoded varint.
* Bits have the following meaning:
*
* | Bit Position | Meaning |
* | ------------- | ----------------------- |
* | 0 | Sender wants timestamps |
* | 1 | Sender wants checksums |
*/
enum query_option_flags {
QUERY_ADD_TIMESTAMPS = 0x1,
QUERY_ADD_CHECKSUMS = 0x2,
};
/* BOLT-61a1365a45cc8b463ddbbe3429d350f8eac787dd #7:
*
* The checksum of a `channel_update` is the CRC32C checksum as specified in
* [RFC3720](https://tools.ietf.org/html/rfc3720#appendix-B.4) of this
* `channel_update` without its `signature` and `timestamp` fields.
*/
static u32 crc32_of_update(const u8 *channel_update)
{
u32 sum;
const u8 *parts[2];
size_t sizes[ARRAY_SIZE(parts)];
get_cupdate_parts(channel_update, parts, sizes);
sum = 0;
for (size_t i = 0; i < ARRAY_SIZE(parts); i++)
sum = crc32c(sum, parts[i], sizes[i]);
return sum;
}
static void get_checksum_and_timestamp(struct routing_state *rstate,
const struct chan *chan,
int direction,
u32 *tstamp, u32 *csum)
{
const struct half_chan *hc = &chan->half[direction];
if (!is_chan_public(chan) || !is_halfchan_defined(hc)) {
*tstamp = *csum = 0;
} else {
const u8 *update = gossip_store_get(tmpctx, rstate->gs,
hc->bcast.index);
*tstamp = hc->bcast.timestamp;
*csum = crc32_of_update(update);
}
}
/* FIXME: This assumes that the tlv type encodes into 1 byte! */
static size_t tlv_len(const tal_t *msg)
{
return 1 + bigsize_len(tal_count(msg)) + tal_count(msg);
}
/*~ When we need to send an array of channels, it might go over our 64k packet
* size. If it doesn't, we recurse, splitting in two, etc. Each message
* indicates what blocks it contains, so the recipient knows when we're
* finished.
*
* tail_blocks is the empty blocks at the end, in case they asked for all
* blocks to 4 billion.
*/
static bool queue_channel_ranges(struct peer *peer,
u32 first_blocknum, u32 number_of_blocks,
u32 tail_blocks,
enum query_option_flags query_option_flags)
{
struct routing_state *rstate = peer->daemon->rstate;
u8 *encoded_scids = encoding_start(tmpctx);
struct tlv_reply_channel_range_tlvs_timestamps_tlv *tstamps;
struct tlv_reply_channel_range_tlvs_checksums_tlv *csums;
struct short_channel_id scid;
bool scid_ok;
/* BOLT #7:
*
* 1. type: 264 (`reply_channel_range`) (`gossip_queries`)
* 2. data:
* * [`chain_hash`:`chain_hash`]
* * [`u32`:`first_blocknum`]
* * [`u32`:`number_of_blocks`]
* * [`byte`:`complete`]
* * [`u16`:`len`]
* * [`len*byte`:`encoded_short_ids`]
*/
const size_t reply_overhead = 32 + 4 + 4 + 1 + 2;
const size_t max_encoded_bytes = 65535 - 2 - reply_overhead;
size_t extension_bytes;
if (query_option_flags & QUERY_ADD_TIMESTAMPS) {
tstamps = tal(tmpctx,
struct tlv_reply_channel_range_tlvs_timestamps_tlv);
tstamps->encoded_timestamps = encoding_start(tstamps);
} else
tstamps = NULL;
if (query_option_flags & QUERY_ADD_CHECKSUMS) {
csums = tal(tmpctx,
struct tlv_reply_channel_range_tlvs_checksums_tlv);
csums->checksums
= tal_arr(csums, struct channel_update_checksums, 0);
} else
csums = NULL;
/* Avoid underflow: we don't use block 0 anyway */
if (first_blocknum == 0)
scid_ok = mk_short_channel_id(&scid, 1, 0, 0);
else
scid_ok = mk_short_channel_id(&scid, first_blocknum, 0, 0);
scid.u64--;
if (!scid_ok)
return false;
/* We keep a `uintmap` of `short_channel_id` to `struct chan *`.
* Unlike a htable, it's efficient to iterate through, but it only
* works because each short_channel_id is basically a 64-bit unsigned
* integer.
*
* First we iterate and gather all the short channel ids. */
while (uintmap_after(&rstate->chanmap, &scid.u64)) {
struct chan *chan;
struct channel_update_timestamps ts;
struct channel_update_checksums cs;
u32 blocknum = short_channel_id_blocknum(&scid);
if (blocknum >= first_blocknum + number_of_blocks)
break;
encoding_add_short_channel_id(&encoded_scids, &scid);
/* FIXME: Store csum in header. */
chan = get_channel(rstate, &scid);
get_checksum_and_timestamp(rstate, chan, 0,
&ts.timestamp_node_id_1,
&cs.checksum_node_id_1);
get_checksum_and_timestamp(rstate, chan, 1,
&ts.timestamp_node_id_2,
&cs.checksum_node_id_2);
if (csums)
tal_arr_expand(&csums->checksums, cs);
if (tstamps)
encoding_add_timestamps(&tstamps->encoded_timestamps,
&ts);
}
extension_bytes = 0;
/* If either of these can't fit in max_encoded_bytes by itself,
* it's over. */
if (csums) {
extension_bytes += tlv_len(csums->checksums);
}
if (tstamps) {
if (!encoding_end_external_type(&tstamps->encoded_timestamps,
&tstamps->encoding_type,
max_encoded_bytes))
goto wont_fit;
/* 1 byte for encoding_type, too */
extension_bytes += 1 + tlv_len(tstamps->encoded_timestamps);
}
/* If we can encode that, fine: send it */
if (extension_bytes <= max_encoded_bytes
&& encoding_end_prepend_type(&encoded_scids,
max_encoded_bytes - extension_bytes)) {
reply_channel_range(peer, first_blocknum,
number_of_blocks + tail_blocks,
encoded_scids,
tstamps, csums);
return true;
}
wont_fit:
/* It wouldn't all fit: divide in half */
/* We assume we can always send one block! */
if (number_of_blocks <= 1) {
/* We always assume we can send 1 blocks worth */
status_broken("Could not fit scids for single block %u",
first_blocknum);
return false;
}
status_debug("queue_channel_ranges full: splitting %u+%u and %u+%u(+%u)",
first_blocknum,
number_of_blocks / 2,
first_blocknum + number_of_blocks / 2,
number_of_blocks - number_of_blocks / 2,
tail_blocks);
return queue_channel_ranges(peer, first_blocknum, number_of_blocks / 2,
0, query_option_flags)
&& queue_channel_ranges(peer, first_blocknum + number_of_blocks / 2,
number_of_blocks - number_of_blocks / 2,
tail_blocks, query_option_flags);
}
/*~ The peer can ask for all channels is a series of blocks. We reply with one
* or more messages containing the short_channel_ids. */
static u8 *handle_query_channel_range(struct peer *peer, const u8 *msg)
{
struct routing_state *rstate = peer->daemon->rstate;
struct bitcoin_blkid chain_hash;
u32 first_blocknum, number_of_blocks, tail_blocks;
struct short_channel_id last_scid;
enum query_option_flags query_option_flags;
#if EXPERIMENTAL_FEATURES
struct tlv_query_channel_range_tlvs *tlvs
= tlv_query_channel_range_tlvs_new(msg);
if (!fromwire_query_channel_range(msg, &chain_hash,
&first_blocknum, &number_of_blocks,
tlvs)) {
return towire_errorfmt(peer, NULL,
"Bad query_channel_range w/tlvs %s",
tal_hex(tmpctx, msg));
}
if (tlvs->query_option)
query_option_flags = tlvs->query_option->query_option_flags;
else
query_option_flags = 0;
#else
if (!fromwire_query_channel_range(msg, &chain_hash,
&first_blocknum, &number_of_blocks)) {
return towire_errorfmt(peer, NULL,
"Bad query_channel_range %s",
tal_hex(tmpctx, msg));
}
query_option_flags = 0;
#endif
/* If they ask for the wrong chain, we give an empty response
* with the `complete` flag unset */
if (!bitcoin_blkid_eq(&peer->daemon->chain_hash, &chain_hash)) {
status_debug("%s sent query_channel_range chainhash %s",
type_to_string(tmpctx, struct node_id, &peer->id),
type_to_string(tmpctx, struct bitcoin_blkid,
&chain_hash));
#if EXPERIMENTAL_FEATURES
u8 *end = towire_reply_channel_range(NULL, &chain_hash, first_blocknum,
number_of_blocks, false, NULL, NULL);
#else
u8 *end = towire_reply_channel_range(NULL, &chain_hash, first_blocknum,
number_of_blocks, false, NULL);
#endif
queue_peer_msg(peer, take(end));
return NULL;
}
/* If they ask for number_of_blocks UINTMAX, and we have to divide
* and conquer, we'll do a lot of unnecessary work. Cap it at the
* last value we have, then send an empty reply. */
if (uintmap_last(&rstate->chanmap, &last_scid.u64)) {
u32 last_block = short_channel_id_blocknum(&last_scid);
/* u64 here avoids overflow on number_of_blocks
UINTMAX for example */
if ((u64)first_blocknum + number_of_blocks > last_block) {
tail_blocks = first_blocknum + number_of_blocks
- last_block - 1;
number_of_blocks -= tail_blocks;
} else
tail_blocks = 0;
} else
tail_blocks = 0;
if (!queue_channel_ranges(peer, first_blocknum, number_of_blocks,
tail_blocks, query_option_flags))
return towire_errorfmt(peer, NULL,
"Invalid query_channel_range %u+%u",
first_blocknum, number_of_blocks + tail_blocks);
return NULL;
}
/*~ This is the reply we get when we send query_channel_range; we keep
* expecting them until the entire range we asked for is covered. */
static const u8 *handle_reply_channel_range(struct peer *peer, const u8 *msg)
{
struct bitcoin_blkid chain;
u8 complete;
u32 first_blocknum, number_of_blocks, start, end;
u8 *encoded;
struct short_channel_id *scids;
size_t n;
unsigned long b;
#if EXPERIMENTAL_FEATURES
struct tlv_reply_channel_range_tlvs *tlvs
= tlv_reply_channel_range_tlvs_new(tmpctx);
if (!fromwire_reply_channel_range(tmpctx, msg, &chain, &first_blocknum,
&number_of_blocks, &complete,
&encoded, tlvs)) {
return towire_errorfmt(peer, NULL,
"Bad reply_channel_range w/tlvs %s",
tal_hex(tmpctx, msg));
}
#else
if (!fromwire_reply_channel_range(tmpctx, msg, &chain, &first_blocknum,
&number_of_blocks, &complete,
&encoded)) {
return towire_errorfmt(peer, NULL,
"Bad reply_channel_range %s",
tal_hex(tmpctx, msg));
}
#endif
if (!bitcoin_blkid_eq(&peer->daemon->chain_hash, &chain)) {
return towire_errorfmt(peer, NULL,
"reply_channel_range for bad chain: %s",
tal_hex(tmpctx, msg));
}
if (!peer->query_channel_blocks) {
return towire_errorfmt(peer, NULL,
"reply_channel_range without query: %s",
tal_hex(tmpctx, msg));
}
/* Beware overflow! */
if (first_blocknum + number_of_blocks < first_blocknum) {
return towire_errorfmt(peer, NULL,
"reply_channel_range invalid %u+%u",
first_blocknum, number_of_blocks);
}
scids = decode_short_ids(tmpctx, encoded);
if (!scids) {
return towire_errorfmt(peer, NULL,
"Bad reply_channel_range encoding %s",
tal_hex(tmpctx, encoded));
}
status_debug("peer %s reply_channel_range %u+%u (of %u+%u) %zu scids",
type_to_string(tmpctx, struct node_id, &peer->id),
first_blocknum, number_of_blocks,
peer->range_first_blocknum,
peer->range_end_blocknum - peer->range_first_blocknum,
tal_count(scids));
/* BOLT #7:
*
* The receiver of `query_channel_range`:
*...
* - MUST respond with one or more `reply_channel_range` whose
* combined range cover the requested `first_blocknum` to
* `first_blocknum` plus `number_of_blocks` minus one.
*/
/* ie. They can be outside range we asked, but they must overlap! */
if (first_blocknum + number_of_blocks <= peer->range_first_blocknum
|| first_blocknum >= peer->range_end_blocknum) {
return towire_errorfmt(peer, NULL,
"reply_channel_range invalid %u+%u for query %u+%u",
first_blocknum, number_of_blocks,
peer->range_first_blocknum,
peer->range_end_blocknum
- peer->range_first_blocknum);
}
start = first_blocknum;
end = first_blocknum + number_of_blocks;
/* Trim to make it a subset of what we want. */
if (start < peer->range_first_blocknum)
start = peer->range_first_blocknum;
if (end > peer->range_end_blocknum)
end = peer->range_end_blocknum;
/* We keep a bitmap of what blocks have been covered by replies: bit 0
* represents block peer->range_first_blocknum */
b = bitmap_ffs(peer->query_channel_blocks,
start - peer->range_first_blocknum,
end - peer->range_first_blocknum);
if (b != end - peer->range_first_blocknum) {
return towire_errorfmt(peer, NULL,
"reply_channel_range %u+%u already have block %lu",
first_blocknum, number_of_blocks,
peer->range_first_blocknum + b);
}
/* Mark that short_channel_ids for this block have been received */
bitmap_fill_range(peer->query_channel_blocks,
start - peer->range_first_blocknum,
end - peer->range_first_blocknum);
peer->range_blocks_remaining -= end - start;
/* Add scids */
n = tal_count(peer->query_channel_scids);
tal_resize(&peer->query_channel_scids, n + tal_count(scids));
memcpy(peer->query_channel_scids + n, scids, tal_bytelen(scids));
/* Still more to go? */
if (peer->range_blocks_remaining)
return NULL;
/* All done, send reply to lightningd: that's currently the only thing
* which triggers this (for testing). Eventually we might start probing
* for gossip information on our own. */
msg = towire_gossip_query_channel_range_reply(NULL,
first_blocknum,
number_of_blocks,
complete,
peer->query_channel_scids);
daemon_conn_send(peer->daemon->master, take(msg));
peer->query_channel_scids = tal_free(peer->query_channel_scids);
peer->query_channel_blocks = tal_free(peer->query_channel_blocks);
return NULL;
}
/*~ 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;
}
/*~ When we ask about an array of short_channel_ids, we get all channel &
* node announcements and channel updates which the peer knows. There's an
* explicit end packet; this is needed to differentiate between 'I'm slow'
* and 'I don't know those channels'. */
static u8 *handle_reply_short_channel_ids_end(struct peer *peer, const u8 *msg)
{
struct bitcoin_blkid chain;
u8 complete;
if (!fromwire_reply_short_channel_ids_end(msg, &chain, &complete)) {
return towire_errorfmt(peer, NULL,
"Bad reply_short_channel_ids_end %s",
tal_hex(tmpctx, msg));
}
if (!bitcoin_blkid_eq(&peer->daemon->chain_hash, &chain)) {
return towire_errorfmt(peer, NULL,
"reply_short_channel_ids_end for bad chain: %s",
tal_hex(tmpctx, msg));
}
if (!peer->scid_query_outstanding) {
return towire_errorfmt(peer, NULL,
"unexpected reply_short_channel_ids_end: %s",
tal_hex(tmpctx, msg));
}
peer->scid_query_outstanding = false;
/* If it wasn't generated by us, it's the dev interface from lightningd
*/
if (!peer->scid_query_was_internal) {
msg = towire_gossip_scids_reply(msg, true, complete);
daemon_conn_send(peer->daemon->master, take(msg));
}
/* All good, no error. */
return NULL;
}
/*~ Arbitrary ordering function of pubkeys.
*
* Note that we could use memcmp() here: even if they had somehow different
* bitwise representations for the same key, we copied them all from struct
* node which should make them unique. Even if not (say, a node vanished
* and reappeared) we'd just end up sending two node_announcement for the
* same node.
*/
static int pubkey_order(const struct node_id *k1,
const struct node_id *k2,
void *unused UNUSED)
{
return node_id_cmp(k1, k2);
}
static void uniquify_node_ids(struct node_id **ids)
{
size_t dst, src;
/* BOLT #7:
*
* - MUST follow with any `node_announcement`s for each
* `channel_announcement`
*
* - SHOULD avoid sending duplicate `node_announcements` in
* response to a single `query_short_channel_ids`.
*/
/* ccan/asort is a typesafe qsort wrapper: like most ccan modules
* it eschews exposing 'void *' pointers and ensures that the
* callback function and its arguments match types correctly. */
asort(*ids, tal_count(*ids), pubkey_order, NULL);
/* Compact the array */
for (dst = 0, src = 0; src < tal_count(*ids); src++) {
if (dst && node_id_eq(&(*ids)[dst-1], &(*ids)[src]))
continue;
(*ids)[dst++] = (*ids)[src];
}
/* And trim to length, so tal_count() gives correct answer. */
tal_resize(ids, dst);
}
/*~ We are fairly careful to avoid the peer DoSing us with channel queries:
* this routine sends information about a single short_channel_id, unless
* it's finished all of them. */
static void maybe_create_next_scid_reply(struct peer *peer)
{
struct routing_state *rstate = peer->daemon->rstate;
size_t i, num;
bool sent = false;
/* BOLT #7:
*
* - MUST respond to each known `short_channel_id` with a
* `channel_announcement` and the latest `channel_update` for each end
* - SHOULD NOT wait for the next outgoing gossip flush
* to send these.
*/
/* Search for next short_channel_id we know about. */
num = tal_count(peer->scid_queries);
for (i = peer->scid_query_idx; !sent && i < num; i++) {
struct chan *chan;
chan = get_channel(rstate, &peer->scid_queries[i]);
if (!chan || !is_chan_public(chan))
continue;
/* BOLT-61a1365a45cc8b463ddbbe3429d350f8eac787dd #7:
* - if bit 0 of `query_flag` is set:
* - MUST reply with a `channel_announcement`
*/
if (peer->scid_query_flags[i] & SCID_QF_ANNOUNCE) {
queue_peer_from_store(peer, &chan->bcast);
sent = true;
}
/* BOLT-61a1365a45cc8b463ddbbe3429d350f8eac787dd #7:
* - if bit 1 of `query_flag` is set and it has received a
* `channel_update` from `node_id_1`:
* - MUST reply with the latest `channel_update` for
* `node_id_1`
* - if bit 2 of `query_flag` is set and it has received a
* `channel_update` from `node_id_2`:
* - MUST reply with the latest `channel_update` for
* `node_id_2` */
if ((peer->scid_query_flags[i] & SCID_QF_UPDATE1)
&& is_halfchan_defined(&chan->half[0])) {
queue_peer_from_store(peer, &chan->half[0].bcast);
sent = true;
}
if ((peer->scid_query_flags[i] & SCID_QF_UPDATE2)
&& is_halfchan_defined(&chan->half[1])) {
queue_peer_from_store(peer, &chan->half[1].bcast);
sent = true;
}
/* BOLT-61a1365a45cc8b463ddbbe3429d350f8eac787dd #7:
* - if bit 3 of `query_flag` is set and it has received
* a `node_announcement` from `node_id_1`:
* - MUST reply with the latest `node_announcement` for
* `node_id_1`
* - if bit 4 of `query_flag` is set and it has received a
* `node_announcement` from `node_id_2`:
* - MUST reply with the latest `node_announcement` for
* `node_id_2` */
/* Save node ids for later transmission of node_announcement */
if (peer->scid_query_flags[i] & SCID_QF_NODE1)
tal_arr_expand(&peer->scid_query_nodes,
chan->nodes[0]->id);
if (peer->scid_query_flags[i] & SCID_QF_NODE2)
tal_arr_expand(&peer->scid_query_nodes,
chan->nodes[1]->id);
}
/* Just finished channels? Remove duplicate nodes. */
if (peer->scid_query_idx != num && i == num)
uniquify_node_ids(&peer->scid_query_nodes);
/* Update index for next time we're called. */
peer->scid_query_idx = i;
/* BOLT #7:
*
* - MUST follow with any `node_announcement`s for each
* `channel_announcement`
* - SHOULD avoid sending duplicate `node_announcements` in response
* to a single `query_short_channel_ids`.
*/
/* If we haven't sent anything above, we look for the next
* node_announcement to send. */
num = tal_count(peer->scid_query_nodes);
for (i = peer->scid_query_nodes_idx; !sent && i < num; i++) {
const struct node *n;
/* Not every node announces itself (we know it exists because
* of a channel_announcement, however) */
n = get_node(rstate, &peer->scid_query_nodes[i]);
if (!n || !n->bcast.index)
continue;
queue_peer_from_store(peer, &n->bcast);
sent = true;
}
peer->scid_query_nodes_idx = i;
/* All finished? */
if (peer->scid_queries
&& peer->scid_query_idx == tal_count(peer->scid_queries)
&& peer->scid_query_nodes_idx == num) {
/* BOLT #7:
*
* - MUST follow these responses with
* `reply_short_channel_ids_end`.
* - if does not maintain up-to-date channel information for
* `chain_hash`:
* - MUST set `complete` to 0.
* - otherwise:
* - SHOULD set `complete` to 1.
*/
/* FIXME: We consider ourselves to have complete knowledge. */
u8 *end = towire_reply_short_channel_ids_end(peer,
&peer->daemon->chain_hash,
true);
queue_peer_msg(peer, take(end));
/* We're done! Clean up so we simply pass-through next time. */
peer->scid_queries = tal_free(peer->scid_queries);
peer->scid_query_flags = tal_free(peer->scid_query_flags);
peer->scid_query_idx = 0;
peer->scid_query_nodes = tal_free(peer->scid_query_nodes);
peer->scid_query_nodes_idx = 0;
}
}
/*~ This is called when the outgoing queue is empty; gossip has lower priority
* than just about anything else. */
static void dump_gossip(struct peer *peer)
{
/* Do we have scid query replies to send? */
maybe_create_next_scid_reply(peer);
}
/*~ This generates a `channel_update` message for one of our channels. We do
* this here, rather than in `channeld` because we (may) need to do it
* ourselves anyway if channeld dies, or when we refresh it once a week. */
static void update_local_channel(struct daemon *daemon,
const struct chan *chan,
int direction,
bool disable,
u16 cltv_expiry_delta,
struct amount_msat htlc_minimum,
u32 fee_base_msat,
u32 fee_proportional_millionths,
struct amount_msat htlc_maximum,
const char *caller)
{
secp256k1_ecdsa_signature dummy_sig;
u8 *update, *msg;
u32 timestamp = gossip_time_now(daemon->rstate).ts.tv_sec;
u8 message_flags, channel_flags;
/* So valgrind doesn't complain */
memset(&dummy_sig, 0, sizeof(dummy_sig));
/* BOLT #7:
*
* The origin node:
*...
* - MUST set `timestamp` to greater than 0, AND to greater than any
* previously-sent `channel_update` for this `short_channel_id`.
* - SHOULD base `timestamp` on a UNIX timestamp.
*/
if (is_halfchan_defined(&chan->half[direction])
&& timestamp == chan->half[direction].bcast.timestamp)
timestamp++;
/* BOLT #7:
*
* The `channel_flags` bitfield is used to indicate the direction of
* the channel: it identifies the node that this update originated
* from and signals various options concerning the channel. The
* following table specifies the meaning of its individual bits:
*
* | Bit Position | Name | Meaning |
* | ------------- | ----------- | -------------------------------- |
* | 0 | `direction` | Direction this update refers to. |
* | 1 | `disable` | Disable the channel. |
*/
channel_flags = direction;
if (disable)
channel_flags |= ROUTING_FLAGS_DISABLED;
/* BOLT #7:
*
* The `message_flags` bitfield is used to indicate the presence of
* optional fields in the `channel_update` message:
*
*| Bit Position | Name | Field |
*...
*| 0 | `option_channel_htlc_max` | `htlc_maximum_msat` |
*/
message_flags = 0 | ROUTING_OPT_HTLC_MAX_MSAT;
/* We create an update with a dummy signature, and hand to hsmd to get
* it signed. */
update = towire_channel_update_option_channel_htlc_max(tmpctx, &dummy_sig,
&daemon->chain_hash,
&chan->scid,
timestamp,
message_flags, channel_flags,
cltv_expiry_delta,
htlc_minimum,
fee_base_msat,
fee_proportional_millionths,
htlc_maximum);
/* Note that we treat the hsmd as synchronous. This is simple (no
* callback hell)!, but may need to change to async if we ever want
* remote HSMs */
if (!wire_sync_write(HSM_FD,
towire_hsm_cupdate_sig_req(tmpctx, update))) {
status_failed(STATUS_FAIL_HSM_IO, "Writing cupdate_sig_req: %s",
strerror(errno));
}
msg = wire_sync_read(tmpctx, HSM_FD);
if (!msg || !fromwire_hsm_cupdate_sig_reply(NULL, msg, &update)) {
status_failed(STATUS_FAIL_HSM_IO,
"Reading cupdate_sig_req: %s",
strerror(errno));
}
/* BOLT #7:
*
* The origin node:
* - MAY create a `channel_update` to communicate the channel parameters to the
* channel peer, even though the channel has not yet been announced (i.e. the
* `announce_channel` bit was not set).
*/
if (!is_chan_public(chan)) {
/* handle_channel_update will not put private updates in the
* broadcast list, but we send it direct to the peer (if we
* have one connected) now */
struct peer *peer = find_peer(daemon,
&chan->nodes[!direction]->id);
if (peer)
queue_peer_msg(peer, update);
}
/* We feed it into routing.c like any other channel_update; it may
* discard it (eg. non-public channel), but it should not complain
* about it being invalid! */
msg = handle_channel_update(daemon->rstate, take(update), caller, NULL);
if (msg)
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"%s: rejected local channel update %s: %s",
caller,
/* Normally we must not touch something taken()
* but we're in deep trouble anyway, and
* handle_channel_update only tal_steals onto
* tmpctx, so it's actually OK. */
tal_hex(tmpctx, update),
tal_hex(tmpctx, msg));
}
/*~ We generate local channel updates lazily; most of the time we simply
* toggle the `local_disabled` flag so we don't use it to route. We never
* change anything else after startup (yet!) */
static void maybe_update_local_channel(struct daemon *daemon,
struct chan *chan, int direction)
{
const struct half_chan *hc = &chan->half[direction];
bool local_disabled;
/* Don't generate a channel_update for an uninitialized channel. */
if (!is_halfchan_defined(hc))
return;
/* Nothing to update? */
local_disabled = is_chan_local_disabled(daemon->rstate, chan);
/*~ Note the inversions here on both sides, which is cheap conversion to
* boolean for the RHS! */
if (!local_disabled == !(hc->channel_flags & ROUTING_FLAGS_DISABLED))
return;
update_local_channel(daemon, chan, direction,
local_disabled,
hc->delay,
hc->htlc_minimum,
hc->base_fee,
hc->proportional_fee,
hc->htlc_maximum,
/* Note this magic C macro which expands to the
* function name, for debug messages */
__func__);
}
/*~ This helper figures out which direction of the channel is from-us; if
* neither, it returns false. This meets Linus' rule "Always return the error",
* without doing some horrible 0/1/-1 return. */
static bool local_direction(struct daemon *daemon,
const struct chan *chan,
int *direction)
{
for (*direction = 0; *direction < 2; (*direction)++) {
if (node_id_eq(&chan->nodes[*direction]->id, &daemon->id))
return true;
}
return false;
}
/*~ 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_update(struct peer *peer, const u8 *msg)
{
struct short_channel_id scid;
struct chan *chan;
const u8 *update;
struct routing_state *rstate = peer->daemon->rstate;
int direction;
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) */
chan = get_channel(rstate, &scid);
if (!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;
}
/* We want the update that comes from our end. */
if (!local_direction(peer->daemon, chan, &direction)) {
status_unusual("peer %s scid %s: not our channel?",
type_to_string(tmpctx, struct node_id, &peer->id),
type_to_string(tmpctx,
struct short_channel_id,
&scid));
update = NULL;
goto out;
}
/* Since we're going to send it out, make sure it's up-to-date. */
maybe_update_local_channel(peer->daemon, chan, direction);
/* It's possible this is zero, if we've never sent a channel_update
* for that channel. */
if (!is_halfchan_defined(&chan->half[direction]))
update = NULL;
else
update = gossip_store_get(tmpctx, rstate->gs,
chan->half[direction].bcast.index);
out:
status_debug("peer %s schanid %s: %s update",
type_to_string(tmpctx, struct node_id, &peer->id),
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;
}
/*~ Return true if the channel information has changed. This can only
* currently happen if the user restarts with different fee options, but we
* don't assume that. */
static bool halfchan_new_info(const struct half_chan *hc,
u16 cltv_delta, struct amount_msat htlc_minimum,
u32 fee_base_msat, u32 fee_proportional_millionths,
struct amount_msat htlc_maximum)
{
if (!is_halfchan_defined(hc))
return true;
return hc->delay != cltv_delta
|| !amount_msat_eq(hc->htlc_minimum, htlc_minimum)
|| hc->base_fee != fee_base_msat
|| hc->proportional_fee != fee_proportional_millionths
|| !amount_msat_eq(hc->htlc_maximum, htlc_maximum);
}
/*~ channeld asks us to update the local channel. */
static bool handle_local_channel_update(struct peer *peer, const u8 *msg)
{
struct chan *chan;
struct short_channel_id scid;
bool disable;
u16 cltv_expiry_delta;
struct amount_msat htlc_minimum, htlc_maximum;
u32 fee_base_msat;
u32 fee_proportional_millionths;
int direction;
/* FIXME: We should get scid from lightningd when setting up the
* connection, so no per-peer daemon can mess with channels other than
* its own! */
if (!fromwire_gossipd_local_channel_update(msg,
&scid,
&disable,
&cltv_expiry_delta,
&htlc_minimum,
&fee_base_msat,
&fee_proportional_millionths,
&htlc_maximum)) {
status_broken("peer %s bad local_channel_update %s",
type_to_string(tmpctx, struct node_id, &peer->id),
tal_hex(tmpctx, msg));
return false;
}
/* Can theoretically happen if channel just closed. */
chan = get_channel(peer->daemon->rstate, &scid);
if (!chan) {
status_debug("peer %s local_channel_update for unknown %s",
type_to_string(tmpctx, struct node_id, &peer->id),
type_to_string(tmpctx, struct short_channel_id,
&scid));
return true;
}
/* You shouldn't be asking for a non-local channel though. */
if (!local_direction(peer->daemon, chan, &direction)) {
status_broken("peer %s bad local_channel_update for non-local %s",
type_to_string(tmpctx, struct node_id, &peer->id),
type_to_string(tmpctx, struct short_channel_id,
&scid));
return false;
}
/* We could change configuration on restart; update immediately.
* Or, if we're *enabling* an announced-disabled channel.
* Or, if it's an unannounced channel (only sending to peer). */
if (halfchan_new_info(&chan->half[direction],
cltv_expiry_delta, htlc_minimum,
fee_base_msat, fee_proportional_millionths,
htlc_maximum)
|| ((chan->half[direction].channel_flags & ROUTING_FLAGS_DISABLED)
&& !disable)
|| !is_chan_public(chan)) {
update_local_channel(peer->daemon, chan, direction,
disable,
cltv_expiry_delta,
htlc_minimum,
fee_base_msat,
fee_proportional_millionths,
htlc_maximum,
__func__);
}
/* Normal case: just toggle local_disabled, and generate broadcast in
* maybe_update_local_channel when/if someone asks about it. */
if (disable)
local_disable_chan(peer->daemon->rstate, chan);
else
local_enable_chan(peer->daemon->rstate, chan);
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_announcement(peer->daemon->rstate, 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:
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_update(peer, msg);
goto handled_cmd;
case WIRE_GOSSIPD_LOCAL_ADD_CHANNEL:
ok = handle_local_add_channel(peer->daemon->rstate, msg, 0);
goto handled_cmd;
case WIRE_GOSSIPD_LOCAL_CHANNEL_UPDATE:
ok = handle_local_channel_update(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_broken("peer %s: unexpected cmd of type %i %s",
type_to_string(tmpctx, struct node_id, &peer->id),
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);
}
/* What gossip level do we set for this to meet our target? */
static enum gossip_level peer_gossip_level(const struct daemon *daemon,
bool gossip_queries_feature)
{
struct peer *peer;
size_t gossip_levels[ARRAY_SIZE(gossip_level_targets)];
enum gossip_level glevel;
/* Old peers always give us a flood. */
if (!gossip_queries_feature)
return GOSSIP_HIGH;
/* Figure out how many we have at each level. */
memset(gossip_levels, 0, sizeof(gossip_levels));
list_for_each(&daemon->peers, peer, list)
gossip_levels[peer->gossip_level]++;
/* If we're missing gossip, try to fill GOSSIP_HIGH */
if (daemon->gossip_missing != NULL)
glevel = GOSSIP_HIGH;
else
glevel = GOSSIP_MEDIUM;
while (gossip_levels[glevel] >= gossip_level_targets[glevel])
glevel++;
return glevel;
}
/*~ 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->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->num_pings_outstanding = 0;
peer->gossip_level = peer_gossip_level(daemon,
peer->gossip_queries_feature);
/* 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 dump_gossip when nothing else to
* send. */
peer->dc = daemon_conn_new(daemon, fds[0],
peer_msg_in, dump_gossip, peer);
/* Free peer if conn closed (destroy_peer closes conn if peer freed) */
tal_steal(peer->dc, peer);
/* This sends the initial timestamp filter. */
setup_gossip_range(peer);
/* BOLT #7:
*
* A node:
* - if the `gossip_queries` feature is negotiated:
* - MUST NOT relay any gossip messages 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 twice-weekly 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,
const struct chan *chan,
const struct half_chan *hc)
{
status_debug("Sending keepalive channel_update for %s",
type_to_string(tmpctx, struct short_channel_id,
&chan->scid));
/* As a side-effect, this will create an update which matches the
* local_disabled state */
update_local_channel(daemon, chan,
hc->channel_flags & ROUTING_FLAGS_DIRECTION,
is_chan_local_disabled(daemon->rstate, chan),
hc->delay,
hc->htlc_minimum,
hc->base_fee,
hc->proportional_fee,
hc->htlc_maximum,
__func__);
}
/* 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;
/* Anything below this highwater mark could be pruned if not refreshed */
s64 highwater = now - daemon->rstate->prune_timeout / 2;
struct node *n;
/* Schedule next run now (prune_timeout is 2 weeks) */
notleak(new_reltimer(&daemon->timers, daemon,
time_from_sec(daemon->rstate->prune_timeout/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 half_chan *hc = half_chan_from(n, c);
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, c, hc);
}
}
/* 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);
}
/* Mutual recursion, so we pre-declare this. */
static void gossip_not_missing(struct daemon *daemon);
/* Pick a random peer which is not already GOSSIP_HIGH. */
static struct peer *random_peer_to_gossip(struct daemon *daemon)
{
u64 target = UINT64_MAX;
struct peer *best = NULL, *i;
/* Reservoir sampling */
list_for_each(&daemon->peers, i, list) {
u64 r = pseudorand_u64();
if (i->gossip_level != GOSSIP_HIGH && r <= target) {
best = i;
target = r;
}
}
return best;
}
/*~ We've found gossip is missing. */
static void gossip_missing(struct daemon *daemon)
{
if (!daemon->gossip_missing) {
status_info("We seem to be missing gossip messages");
/* FIXME: we could use query_channel_range. */
/* Make some peers gossip harder. */
for (size_t i = 0; i < gossip_level_targets[GOSSIP_HIGH]; i++) {
struct peer *peer = random_peer_to_gossip(daemon);
if (!peer)
break;
status_info("%s: gossip harder!",
type_to_string(tmpctx, struct node_id,
&peer->id));
peer->gossip_level = GOSSIP_HIGH;
setup_gossip_range(peer);
}
}
tal_free(daemon->gossip_missing);
/* Check again in 10 minutes. */
daemon->gossip_missing = new_reltimer(&daemon->timers, daemon,
time_from_sec(600),
gossip_not_missing, daemon);
}
/*~ This is a timer, which goes off 10 minutes after the last time we noticed
* that gossip was missing. */
static void gossip_not_missing(struct daemon *daemon)
{
/* Corner case: no peers, try again! */
if (list_empty(&daemon->peers))
gossip_missing(daemon);
else {
struct peer *peer;
daemon->gossip_missing = tal_free(daemon->gossip_missing);
status_info("We seem to be caught up on gossip messages");
/* Free any lagging/stale unknown scids. */
daemon->unknown_scids = tal_free(daemon->unknown_scids);
/* Reset peers we marked as HIGH */
list_for_each(&daemon->peers, peer, list) {
if (peer->gossip_level != GOSSIP_HIGH)
continue;
if (!peer->gossip_queries_feature)
continue;
peer->gossip_level = peer_gossip_level(daemon, true);
setup_gossip_range(peer);
}
}
}
/*~ 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 update_channel_interval;
u32 *dev_gossip_time;
if (!fromwire_gossipctl_init(daemon, msg,
&daemon->chain_hash,
&daemon->id, &daemon->globalfeatures,
daemon->rgb,
daemon->alias,
/* 1 week in seconds
* (unless --dev-channel-update-interval) */
&update_channel_interval,
&daemon->announcable,
&dev_gossip_time)) {
master_badmsg(WIRE_GOSSIPCTL_INIT, msg);
}
/* Prune time (usually 2 weeks) is twice update time */
daemon->rstate = new_routing_state(daemon,
chainparams_by_chainhash(&daemon->chain_hash),
&daemon->id,
update_channel_interval * 2,
&daemon->peers,
take(dev_gossip_time));
/* Load stored gossip messages */
if (!gossip_store_load(daemon->rstate, daemon->rstate->gs))
gossip_missing(daemon);
/* 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 weekly refresh timer. */
notleak(new_reltimer(&daemon->timers, daemon,
time_from_sec(daemon->rstate->prune_timeout/4),
gossip_refresh_network, 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;
u64 riskfactor_by_million;
u32 max_hops;
u8 *out;
struct route_hop *hops;
double fuzz;
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_by_million,
&final_cltv, &fuzz,
&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_by_million / 1000000.0, final_cltv,
fuzz, pseudorand_u64(), excluded, max_hops);
out = towire_gossip_getroute_reply(NULL, 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;
}
/*~ Marshal (possibly) both channel directions into entries. */
static void append_channel(struct routing_state *rstate,
const struct gossip_getchannels_entry ***entries,
const struct chan *chan,
const struct node_id *srcfilter)
{
struct gossip_getchannels_entry *e = tal(*entries, struct gossip_getchannels_entry);
e->node[0] = chan->nodes[0]->id;
e->node[1] = chan->nodes[1]->id;
e->sat = chan->sat;
e->local_disabled = is_chan_local_disabled(rstate, chan);
e->public = is_chan_public(chan);
e->short_channel_id = chan->scid;
if (!srcfilter || node_id_eq(&e->node[0], srcfilter))
e->e[0] = hc_entry(*entries, chan, 0);
else
e->e[0] = NULL;
if (!srcfilter || node_id_eq(&e->node[1], srcfilter))
e->e[1] = hc_entry(*entries, chan, 1);
else
e->e[1] = NULL;
/* We choose not to tell lightningd about channels with no updates,
* as they're unusable and can't be represented in the listchannels
* JSON output we use anyway. */
if (e->e[0] || e->e[1])
tal_arr_expand(entries, e);
}
/*~ This is where lightningd asks for all channels we know about. */
static struct io_plan *getchannels_req(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
u8 *out;
const struct gossip_getchannels_entry **entries;
struct chan *chan;
struct short_channel_id *scid, *prev;
struct node_id *source;
bool complete = true;
/* Note: scid is marked optional in gossip_wire.csv */
if (!fromwire_gossip_getchannels_request(msg, msg, &scid, &source,
&prev))
master_badmsg(WIRE_GOSSIP_GETCHANNELS_REQUEST, msg);
entries = tal_arr(tmpctx, const struct gossip_getchannels_entry *, 0);
/* They can ask about a particular channel by short_channel_id */
if (scid) {
chan = get_channel(daemon->rstate, scid);
if (chan)
append_channel(daemon->rstate, &entries, chan, NULL);
} else if (source) {
struct node *s = get_node(daemon->rstate, source);
if (s) {
struct chan_map_iter i;
struct chan *c;
for (c = first_chan(s, &i); c; c = next_chan(s, &i)) {
append_channel(daemon->rstate,
&entries, c, source);
}
}
} else {
u64 idx;
/* For the more general case, we just iterate through every
* short channel id, starting with previous if any (there is
* no scid 0). */
idx = prev ? prev->u64 : 0;
while ((chan = uintmap_after(&daemon->rstate->chanmap, &idx))) {
append_channel(daemon->rstate, &entries, chan, NULL);
/* Limit how many we do at once. */
if (tal_count(entries) == 4096) {
complete = false;
break;
}
}
}
out = towire_gossip_getchannels_reply(NULL, complete, entries);
daemon_conn_send(daemon->master, take(out));
return daemon_conn_read_next(conn, daemon->master);
}
/*~ Similarly, lightningd asks us for all nodes when it gets `listnodes` */
/* We keep pointers into n, assuming it won't change. */
static void add_node_entry(const tal_t *ctx,
struct daemon *daemon,
const struct node *n,
struct gossip_getnodes_entry *e)
{
e->nodeid = n->id;
if (get_node_announcement(ctx, daemon, n,
e->color, e->alias,
&e->globalfeatures,
&e->addresses)) {
e->last_timestamp = n->bcast.timestamp;
} else {
/* Timestamp on wire is an unsigned 32 bit: we use a 64-bit
* signed, so -1 means "we never received a
* channel_update". */
e->last_timestamp = -1;
}
}
/* Simply routine when they ask for `listnodes` */
static struct io_plan *getnodes(struct io_conn *conn, struct daemon *daemon,
const u8 *msg)
{
u8 *out;
struct node *n;
const struct gossip_getnodes_entry **nodes;
struct gossip_getnodes_entry *node_arr;
struct node_id *id;
if (!fromwire_gossip_getnodes_request(tmpctx, msg, &id))
master_badmsg(WIRE_GOSSIP_GETNODES_REQUEST, msg);
/* Format of reply is the same whether they ask for a specific node
* (0 or one responses) or all nodes (0 or more) */
if (id) {
n = get_node(daemon->rstate, id);
if (n) {
node_arr = tal_arr(tmpctx,
struct gossip_getnodes_entry,
1);
add_node_entry(node_arr, daemon, n, &node_arr[0]);
} else {
nodes = NULL;
node_arr = NULL;
}
} else {
struct node_map_iter it;
size_t i = 0;
node_arr = tal_arr(tmpctx, struct gossip_getnodes_entry,
node_map_count(daemon->rstate->nodes));
n = node_map_first(daemon->rstate->nodes, &it);
while (n != NULL) {
add_node_entry(node_arr, daemon, n, &node_arr[i++]);
n = node_map_next(daemon->rstate->nodes, &it);
}
assert(i == node_map_count(daemon->rstate->nodes));
}
/* FIXME: towire wants array of pointers. */
nodes = tal_arr(node_arr, const struct gossip_getnodes_entry *,
tal_count(node_arr));
for (size_t i = 0; i < tal_count(node_arr); i++)
nodes[i] = &node_arr[i];
out = towire_gossip_getnodes_reply(NULL, nodes);
daemon_conn_send(daemon->master, take(out));
return daemon_conn_read_next(conn, daemon->master);
}
/*~ We currently have a JSON command to ping a peer: it ends up here, where
* gossipd generates the actual ping and sends it like any other gossip. */
static struct io_plan *ping_req(struct io_conn *conn, struct daemon *daemon,
const u8 *msg)
{
struct node_id id;
u16 num_pong_bytes, len;
struct peer *peer;
u8 *ping;
if (!fromwire_gossip_ping(msg, &id, &num_pong_bytes, &len))
master_badmsg(WIRE_GOSSIP_PING, msg);
/* Even if lightningd were to check for valid ids, there's a race
* where it might vanish before we read this command; cleaner to
* handle it here with 'sent' = false. */
peer = find_peer(daemon, &id);
if (!peer) {
daemon_conn_send(daemon->master,
take(towire_gossip_ping_reply(NULL, &id,
false, 0)));
goto out;
}
/* It should never ask for an oversize ping. */
ping = make_ping(peer, num_pong_bytes, len);
if (tal_count(ping) > 65535)
status_failed(STATUS_FAIL_MASTER_IO, "Oversize ping");
queue_peer_msg(peer, take(ping));
status_debug("sending ping expecting %sresponse",
num_pong_bytes >= 65532 ? "no " : "");
/* BOLT #1:
*
* A node receiving a `ping` message:
*...
* - if `num_pong_bytes` is less than 65532:
* - MUST respond by sending a `pong` message, with `byteslen` equal
* to `num_pong_bytes`.
* - otherwise (`num_pong_bytes` is **not** less than 65532):
* - MUST ignore the `ping`.
*/
if (num_pong_bytes >= 65532)
daemon_conn_send(daemon->master,
take(towire_gossip_ping_reply(NULL, &id,
true, 0)));
else
/* We'll respond to lightningd once the pong comes in */
peer->num_pings_outstanding++;
out:
return daemon_conn_read_next(conn, daemon->master);
}
/*~ If a node has no public channels (other than the one to us), it's not
* a very useful route to tell anyone about. */
static bool node_has_public_channels(const struct node *peer,
const struct chan *exclude)
{
struct chan_map_iter i;
struct chan *c;
for (c = first_chan(peer, &i); c; c = next_chan(peer, &i)) {
if (c == exclude)
continue;
if (is_chan_public(c))
return true;
}
return false;
}
/*~ The `exposeprivate` flag is a trinary: NULL == dynamic, otherwise
* value decides. Thus, we provide two wrappers for clarity: */
static bool never_expose(bool *exposeprivate)
{
return exposeprivate && !*exposeprivate;
}
static bool always_expose(bool *exposeprivate)
{
return exposeprivate && *exposeprivate;
}
/*~ For routeboost, we offer payers a hint of what incoming channels might
* have capacity for their payment. To do this, lightningd asks for the
* information about all channels to this node; but gossipd doesn't know about
* current capacities, so lightningd selects which to use. */
static struct io_plan *get_incoming_channels(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
struct node *node;
struct route_info *public = tal_arr(tmpctx, struct route_info, 0);
struct route_info *private = tal_arr(tmpctx, struct route_info, 0);
bool has_public;
bool *exposeprivate;
if (!fromwire_gossip_get_incoming_channels(tmpctx, msg, &exposeprivate))
master_badmsg(WIRE_GOSSIP_GET_INCOMING_CHANNELS, msg);
status_debug("exposeprivate = %s",
exposeprivate ? (*exposeprivate ? "TRUE" : "FALSE") : "NULL");
status_debug("msg = %s", tal_hex(tmpctx, msg));
status_debug("always_expose = %u, never_expose = %u",
always_expose(exposeprivate), never_expose(exposeprivate));
has_public = always_expose(exposeprivate);
node = get_node(daemon->rstate, &daemon->rstate->local_id);
if (node) {
struct chan_map_iter i;
struct chan *c;
for (c = first_chan(node, &i); c; c = next_chan(node, &i)) {
const struct half_chan *hc;
struct route_info ri;
hc = &c->half[half_chan_to(node, c)];
if (!is_halfchan_enabled(hc))
continue;
ri.pubkey = other_node(node, c)->id;
ri.short_channel_id = c->scid;
ri.fee_base_msat = hc->base_fee;
ri.fee_proportional_millionths = hc->proportional_fee;
ri.cltv_expiry_delta = hc->delay;
has_public |= is_chan_public(c);
/* If peer doesn't have other public channels,
* no point giving route */
if (!node_has_public_channels(other_node(node, c), c))
continue;
if (always_expose(exposeprivate) || is_chan_public(c))
tal_arr_expand(&public, ri);
else
tal_arr_expand(&private, ri);
}
}
/* If no public channels (even deadend ones!), share private ones. */
if (!has_public && !never_expose(exposeprivate))
msg = towire_gossip_get_incoming_channels_reply(NULL, private);
else
msg = towire_gossip_get_incoming_channels_reply(NULL, public);
daemon_conn_send(daemon->master, take(msg));
return daemon_conn_read_next(conn, daemon->master);
}
#if DEVELOPER
static struct io_plan *query_scids_req(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
struct node_id id;
struct short_channel_id *scids;
struct peer *peer;
if (!fromwire_gossip_query_scids(msg, msg, &id, &scids))
master_badmsg(WIRE_GOSSIP_QUERY_SCIDS, msg);
peer = find_peer(daemon, &id);
if (!peer) {
status_broken("query_scids: unknown peer %s",
type_to_string(tmpctx, struct node_id, &id));
daemon_conn_send(daemon->master,
take(towire_gossip_scids_reply(NULL,
false, false)));
} else if (!query_short_channel_ids(daemon, peer, scids, false))
daemon_conn_send(daemon->master,
take(towire_gossip_scids_reply(NULL,
false, false)));
return daemon_conn_read_next(conn, daemon->master);
}
/* BOLT #7:
*
* ### The `gossip_timestamp_filter` Message
*...
* This message allows a node to constrain future gossip messages to
* a specific range. A node which wants any gossip messages would have
* to send this, otherwise `gossip_queries` negotiation means no gossip
* messages would be received.
*
* Note that this filter replaces any previous one, so it can be used
* multiple times to change the gossip from a peer. */
/* This is the entry point for dev_send_timestamp_filter testing. */
static struct io_plan *send_timestamp_filter(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
struct node_id id;
u32 first, range;
struct peer *peer;
if (!fromwire_gossip_send_timestamp_filter(msg, &id, &first, &range))
master_badmsg(WIRE_GOSSIP_SEND_TIMESTAMP_FILTER, msg);
peer = find_peer(daemon, &id);
if (!peer) {
status_broken("send_timestamp_filter: unknown peer %s",
type_to_string(tmpctx, struct node_id, &id));
goto out;
}
if (!peer->gossip_queries_feature) {
status_broken("send_timestamp_filter: no gossip_query support in peer %s",
type_to_string(tmpctx, struct node_id, &id));
goto out;
}
msg = towire_gossip_timestamp_filter(NULL, &daemon->chain_hash,
first, range);
queue_peer_msg(peer, take(msg));
out:
return daemon_conn_read_next(conn, daemon->master);
}
/* FIXME: One day this will be called internally; for now it's just for
* testing with dev_query_channel_range. */
static struct io_plan *query_channel_range(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
struct node_id id;
u32 first_blocknum, number_of_blocks;
struct peer *peer;
if (!fromwire_gossip_query_channel_range(msg, &id, &first_blocknum,
&number_of_blocks))
master_badmsg(WIRE_GOSSIP_QUERY_SCIDS, msg);
peer = find_peer(daemon, &id);
if (!peer) {
status_broken("query_channel_range: unknown peer %s",
type_to_string(tmpctx, struct node_id, &id));
goto fail;
}
if (!peer->gossip_queries_feature) {
status_broken("query_channel_range: no gossip_query support in peer %s",
type_to_string(tmpctx, struct node_id, &id));
goto fail;
}
if (peer->query_channel_blocks) {
status_broken("query_channel_range: previous query active");
goto fail;
}
/* Check for overflow on 32-bit machines! */
if (BITMAP_NWORDS(number_of_blocks) < number_of_blocks / BITMAP_WORD_BITS) {
status_broken("query_channel_range: huge number_of_blocks (%u) not supported",
number_of_blocks);
goto fail;
}
status_debug("sending query_channel_range for blocks %u+%u",
first_blocknum, number_of_blocks);
#if EXPERIMENTAL_FEATURES
msg = towire_query_channel_range(NULL, &daemon->chain_hash,
first_blocknum, number_of_blocks,
NULL);
#else
msg = towire_query_channel_range(NULL, &daemon->chain_hash,
first_blocknum, number_of_blocks);
#endif
queue_peer_msg(peer, take(msg));
peer->range_first_blocknum = first_blocknum;
peer->range_end_blocknum = first_blocknum + number_of_blocks;
peer->range_blocks_remaining = number_of_blocks;
peer->query_channel_blocks = tal_arrz(peer, bitmap,
BITMAP_NWORDS(number_of_blocks));
peer->query_channel_scids = tal_arr(peer, struct short_channel_id, 0);
out:
return daemon_conn_read_next(conn, daemon->master);
fail:
daemon_conn_send(daemon->master,
take(towire_gossip_query_channel_range_reply(NULL,
0, 0,
false,
NULL)));
goto out;
}
/* This is a testing hack to allow us to artificially lower the maximum bytes
* of short_channel_ids we'll encode, using dev_set_max_scids_encode_size. */
static struct io_plan *dev_set_max_scids_encode_size(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
if (!fromwire_gossip_dev_set_max_scids_encode_size(msg,
&max_encoding_bytes))
master_badmsg(WIRE_GOSSIP_DEV_SET_MAX_SCIDS_ENCODE_SIZE, msg);
status_debug("Set max_scids_encode_bytes to %u", max_encoding_bytes);
return daemon_conn_read_next(conn, daemon->master);
}
/* Another testing hack */
static struct io_plan *dev_gossip_suppress(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
if (!fromwire_gossip_dev_suppress(msg))
master_badmsg(WIRE_GOSSIP_DEV_SUPPRESS, msg);
status_unusual("Suppressing all gossip");
suppress_gossip = true;
return daemon_conn_read_next(conn, daemon->master);
}
static struct io_plan *dev_gossip_memleak(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
struct htable *memtable;
bool found_leak;
memtable = memleak_enter_allocations(tmpctx, msg, msg);
/* Now delete daemon and those which it has pointers to. */
memleak_remove_referenced(memtable, daemon);
found_leak = dump_memleak(memtable);
daemon_conn_send(daemon->master,
take(towire_gossip_dev_memleak_reply(NULL,
found_leak)));
return daemon_conn_read_next(conn, daemon->master);
}
static struct io_plan *dev_compact_store(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
bool done = gossip_store_compact(daemon->rstate->gs);
daemon_conn_send(daemon->master,
take(towire_gossip_dev_compact_store_reply(NULL,
done)));
return daemon_conn_read_next(conn, daemon->master);
}
static struct io_plan *dev_gossip_set_time(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
u32 time;
if (!fromwire_gossip_dev_set_time(msg, &time))
master_badmsg(WIRE_GOSSIP_DEV_SET_TIME, msg);
if (!daemon->rstate->gossip_time)
daemon->rstate->gossip_time = tal(daemon->rstate, struct timeabs);
daemon->rstate->gossip_time->ts.tv_sec = time;
daemon->rstate->gossip_time->ts.tv_nsec = 0;
return daemon_conn_read_next(conn, daemon->master);
}
#endif /* DEVELOPER */
/*~ lightningd: so, tell me about this channel, so we can forward to it. */
static struct io_plan *get_channel_peer(struct io_conn *conn,
struct daemon *daemon, const u8 *msg)
{
struct short_channel_id scid;
struct chan *chan;
const struct node_id *key;
int direction;
if (!fromwire_gossip_get_channel_peer(msg, &scid))
master_badmsg(WIRE_GOSSIP_GET_CHANNEL_PEER, msg);
chan = get_channel(daemon->rstate, &scid);
if (!chan) {
status_debug("Failed to resolve channel %s",
type_to_string(tmpctx, struct short_channel_id, &scid));
key = NULL;
} else if (local_direction(daemon, chan, &direction)) {
key = &chan->nodes[!direction]->id;
} else {
status_debug("Resolved channel %s was not local",
type_to_string(tmpctx, struct short_channel_id,
&scid));
key = NULL;
}
daemon_conn_send(daemon->master,
take(towire_gossip_get_channel_peer_reply(NULL, key)));
return daemon_conn_read_next(conn, daemon->master);
}
/*~ We queue incoming channel_announcement pending confirmation from lightningd
* that it really is an unspent output. Here's its reply. */
static struct io_plan *handle_txout_reply(struct io_conn *conn,
struct daemon *daemon, const u8 *msg)
{
struct short_channel_id scid;
u8 *outscript;
struct amount_sat sat;
bool was_unknown;
if (!fromwire_gossip_get_txout_reply(msg, msg, &scid, &sat, &outscript))
master_badmsg(WIRE_GOSSIP_GET_TXOUT_REPLY, msg);
/* Were we looking specifically for this? */
was_unknown = false;
for (size_t i = 0; i < tal_count(daemon->unknown_scids); i++) {
if (short_channel_id_eq(&daemon->unknown_scids[i], &scid)) {
was_unknown = true;
tal_arr_remove(&daemon->unknown_scids, i);
break;
}
}
/* Outscript is NULL if it's not an unspent output */
if (handle_pending_cannouncement(daemon->rstate, &scid, sat, outscript)
&& was_unknown) {
/* It was real: we're missing gossip. */
gossip_missing(daemon);
}
/* Anywhere we might have announced a channel, we check if it's time to
* announce ourselves (ie. if we just announced our own first channel) */
maybe_send_own_node_announce(daemon);
return daemon_conn_read_next(conn, daemon->master);
}
/* Fix up the channel_update to include the type if it doesn't currently have
* one. See ElementsProject/lightning#1730 and lightningnetwork/lnd#1599 for the
* in-depth discussion on why we break message parsing here... */
static u8 *patch_channel_update(const tal_t *ctx, u8 *channel_update TAKES)
{
u8 *fixed;
if (channel_update != NULL &&
fromwire_peektype(channel_update) != WIRE_CHANNEL_UPDATE) {
/* This should be a channel_update, prefix with the
* WIRE_CHANNEL_UPDATE type, but isn't. Let's prefix it. */
fixed = tal_arr(ctx, u8, 0);
towire_u16(&fixed, WIRE_CHANNEL_UPDATE);
towire(&fixed, channel_update, tal_bytelen(channel_update));
if (taken(channel_update))
tal_free(channel_update);
return fixed;
} else {
return tal_dup_arr(ctx, u8,
channel_update, tal_count(channel_update), 0);
}
}
/* Return NULL if the wrapped onion error message has no channel_update field,
* or return the embedded channel_update message otherwise. */
static u8 *channel_update_from_onion_error(const tal_t *ctx,
const u8 *onion_message)
{
u8 *channel_update = NULL;
struct amount_msat unused_msat;
u32 unused32;
/* Identify failcodes that have some channel_update.
*
* TODO > BOLT 1.0: Add new failcodes when updating to a
* new BOLT version. */
if (!fromwire_temporary_channel_failure(ctx,
onion_message,
&channel_update) &&
!fromwire_amount_below_minimum(ctx,
onion_message, &unused_msat,
&channel_update) &&
!fromwire_fee_insufficient(ctx,
onion_message, &unused_msat,
&channel_update) &&
!fromwire_incorrect_cltv_expiry(ctx,
onion_message, &unused32,
&channel_update) &&
!fromwire_expiry_too_soon(ctx,
onion_message,
&channel_update))
/* No channel update. */
return NULL;
return patch_channel_update(ctx, take(channel_update));
}
/*~ lightningd tells us when a payment has failed; we mark the channel (or
* node) unusable here if it's a permanent failure, and unpack any
* channel_update contained in the error. */
static struct io_plan *handle_payment_failure(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
struct node_id erring_node;
struct short_channel_id erring_channel;
u8 erring_channel_direction;
u8 *error;
enum onion_type failcode;
u8 *channel_update;
if (!fromwire_gossip_payment_failure(msg, msg,
&erring_node,
&erring_channel,
&erring_channel_direction,
&error))
master_badmsg(WIRE_GOSSIP_PAYMENT_FAILURE, msg);
failcode = fromwire_peektype(error);
channel_update = channel_update_from_onion_error(tmpctx, error);
if (channel_update)
status_debug("Extracted channel_update %s from onionreply %s",
tal_hex(tmpctx, channel_update),
tal_hex(tmpctx, error));
routing_failure(daemon->rstate,
&erring_node,
&erring_channel,
erring_channel_direction,
failcode,
channel_update);
return daemon_conn_read_next(conn, daemon->master);
}
/*~ This is where lightningd tells us that a channel's funding transaction has
* been spent. */
static struct io_plan *handle_outpoint_spent(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
struct short_channel_id scid;
struct chan *chan;
struct routing_state *rstate = daemon->rstate;
if (!fromwire_gossip_outpoint_spent(msg, &scid))
master_badmsg(WIRE_GOSSIP_OUTPOINT_SPENT, msg);
chan = get_channel(rstate, &scid);
if (chan) {
status_debug(
"Deleting channel %s due to the funding outpoint being "
"spent",
type_to_string(msg, struct short_channel_id, &scid));
remove_channel_from_store(rstate, chan);
/* Freeing is sufficient since everything else is allocated off
* of the channel and this takes care of unregistering
* the channel */
free_chan(rstate, chan);
}
return daemon_conn_read_next(conn, daemon->master);
}
/*~ This is sent by lightningd when it kicks off 'closingd': we disable it
* in both directions.
*
* We'll leave it to handle_outpoint_spent to delete the channel from our view
* once the close gets confirmed. This avoids having strange states in which the
* channel is list in our peer list but won't be returned when listing public
* channels. This does not send out updates since that's triggered by the peer
* connection closing.
*/
static struct io_plan *handle_local_channel_close(struct io_conn *conn,
struct daemon *daemon,
const u8 *msg)
{
struct short_channel_id scid;
struct chan *chan;
struct routing_state *rstate = daemon->rstate;
if (!fromwire_gossip_local_channel_close(msg, &scid))
master_badmsg(WIRE_GOSSIP_LOCAL_CHANNEL_CLOSE, msg);
chan = get_channel(rstate, &scid);
if (chan)
local_disable_chan(rstate, chan);
return daemon_conn_read_next(conn, daemon->master);
}
/*~ This routine handles all the commands from lightningd. */
static struct io_plan *recv_req(struct io_conn *conn,
const u8 *msg,
struct daemon *daemon)
{
enum gossip_wire_type t = fromwire_peektype(msg);
switch (t) {
case WIRE_GOSSIPCTL_INIT:
return gossip_init(conn, daemon, msg);
case WIRE_GOSSIP_GETNODES_REQUEST:
return getnodes(conn, daemon, msg);
case WIRE_GOSSIP_GETROUTE_REQUEST:
return getroute_req(conn, daemon, msg);
case WIRE_GOSSIP_GETCHANNELS_REQUEST:
return getchannels_req(conn, daemon, msg);
case WIRE_GOSSIP_GET_CHANNEL_PEER:
return get_channel_peer(conn, daemon, msg);
case WIRE_GOSSIP_GET_TXOUT_REPLY:
return handle_txout_reply(conn, daemon, msg);
case WIRE_GOSSIP_PAYMENT_FAILURE:
return handle_payment_failure(conn, daemon, msg);
case WIRE_GOSSIP_OUTPOINT_SPENT:
return handle_outpoint_spent(conn, daemon, msg);
case WIRE_GOSSIP_LOCAL_CHANNEL_CLOSE:
return handle_local_channel_close(conn, daemon, msg);
case WIRE_GOSSIP_PING:
return ping_req(conn, daemon, msg);
case WIRE_GOSSIP_GET_INCOMING_CHANNELS:
return get_incoming_channels(conn, daemon, msg);
#if DEVELOPER
case WIRE_GOSSIP_QUERY_SCIDS:
return query_scids_req(conn, daemon, msg);
case WIRE_GOSSIP_SEND_TIMESTAMP_FILTER:
return send_timestamp_filter(conn, daemon, msg);
case WIRE_GOSSIP_QUERY_CHANNEL_RANGE:
return query_channel_range(conn, daemon, msg);
case WIRE_GOSSIP_DEV_SET_MAX_SCIDS_ENCODE_SIZE:
return dev_set_max_scids_encode_size(conn, daemon, msg);
case WIRE_GOSSIP_DEV_SUPPRESS:
return dev_gossip_suppress(conn, daemon, msg);
case WIRE_GOSSIP_DEV_MEMLEAK:
return dev_gossip_memleak(conn, daemon, msg);
case WIRE_GOSSIP_DEV_COMPACT_STORE:
return dev_compact_store(conn, daemon, msg);
case WIRE_GOSSIP_DEV_SET_TIME:
return dev_gossip_set_time(conn, daemon, msg);
#else
case WIRE_GOSSIP_QUERY_SCIDS:
case WIRE_GOSSIP_SEND_TIMESTAMP_FILTER:
case WIRE_GOSSIP_QUERY_CHANNEL_RANGE:
case WIRE_GOSSIP_DEV_SET_MAX_SCIDS_ENCODE_SIZE:
case WIRE_GOSSIP_DEV_SUPPRESS:
case WIRE_GOSSIP_DEV_MEMLEAK:
case WIRE_GOSSIP_DEV_COMPACT_STORE:
case WIRE_GOSSIP_DEV_SET_TIME:
break;
#endif /* !DEVELOPER */
/* We send these, we don't receive them */
case WIRE_GOSSIP_GETNODES_REPLY:
case WIRE_GOSSIP_GETROUTE_REPLY:
case WIRE_GOSSIP_GETCHANNELS_REPLY:
case WIRE_GOSSIP_PING_REPLY:
case WIRE_GOSSIP_SCIDS_REPLY:
case WIRE_GOSSIP_QUERY_CHANNEL_RANGE_REPLY:
case WIRE_GOSSIP_GET_CHANNEL_PEER_REPLY:
case WIRE_GOSSIP_GET_INCOMING_CHANNELS_REPLY:
case WIRE_GOSSIP_GET_TXOUT:
case WIRE_GOSSIP_DEV_MEMLEAK_REPLY:
case WIRE_GOSSIP_DEV_COMPACT_STORE_REPLY:
break;
}
/* Master shouldn't give bad requests. */
status_failed(STATUS_FAIL_MASTER_IO, "%i: %s",
t, tal_hex(tmpctx, msg));
}
/* This is called when lightningd closes its connection to us. We simply
* exit. */
static void master_gone(struct daemon_conn *master UNUSED)
{
daemon_shutdown();
/* Can't tell master, it's gone. */
exit(2);
}
int main(int argc, char *argv[])
{
setup_locale();
struct daemon *daemon;
subdaemon_setup(argc, argv);
daemon = tal(NULL, struct daemon);
list_head_init(&daemon->peers);
daemon->unknown_scids = tal_arr(daemon, struct short_channel_id, 0);
daemon->gossip_missing = NULL;
/* Note the use of time_mono() here. That's a monotonic clock, which
* is really useful: it can only be used to measure relative events
* (there's no correspondence to time-since-Ken-grew-a-beard or
* anything), but unlike time_now(), this will never jump backwards by
* half a second and leave me wondering how my tests failed CI! */
timers_init(&daemon->timers, time_mono());
/* Our daemons always use STDIN for commands from lightningd. */
daemon->master = daemon_conn_new(daemon, STDIN_FILENO,
recv_req, NULL, daemon);
tal_add_destructor(daemon->master, master_gone);
status_setup_async(daemon->master);
/* connectd is already started, and uses this fd to ask us things. */
daemon->connectd = daemon_conn_new(daemon, CONNECTD_FD,
connectd_req, NULL, daemon);
/* This loop never exits. io_loop() only returns if a timer has
* expired, or io_break() is called, or all fds are closed. We don't
* use io_break and closing the lightningd fd calls master_gone()
* which exits. */
for (;;) {
struct timer *expired = NULL;
io_loop(&daemon->timers, &expired);
timer_expired(daemon, expired);
}
}
/*~ Note that the actual routing stuff is in routing.c; you might want to
* check that out later.
*
* But that's the last of the global daemons. We now move on to the first of
* the per-peer daemons: openingd/openingd.c.
*/
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