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#include "routing.h"
#include <arpa/inet.h>
#include <bitcoin/block.h>
#include <bitcoin/script.h>
#include <ccan/array_size/array_size.h>
#include <ccan/endian/endian.h>
#include <ccan/structeq/structeq.h>
#include <ccan/tal/str/str.h>
#include <common/features.h>
#include <common/pseudorand.h>
#include <common/status.h>
#include <common/type_to_string.h>
#include <common/wire_error.h>
#include <common/wireaddr.h>
#include <gossipd/gen_gossip_wire.h>
#include <inttypes.h>
#include <wire/gen_peer_wire.h>
#ifndef SUPERVERBOSE
#define SUPERVERBOSE(...)
#endif
/* 365.25 * 24 * 60 / 10 */
#define BLOCKS_PER_YEAR 52596
/* For overflow avoidance, we never deal with msatoshi > 40 bits. */
#define MAX_MSATOSHI (1ULL << 40)
/* Proportional fee must be less than 24 bits, so never overflows. */
#define MAX_PROPORTIONAL_FEE (1 << 24)
/* We've unpacked and checked its signatures, now we wait for master to tell
* us the txout to check */
struct pending_cannouncement {
/* Off routing_state->pending_cannouncement */
struct list_node list;
/* Unpacked fields here */
struct short_channel_id short_channel_id;
struct pubkey node_id_1;
struct pubkey node_id_2;
struct pubkey bitcoin_key_1;
struct pubkey bitcoin_key_2;
/* The raw bits */
const u8 *announce;
/* Deferred updates, if we received them while waiting for
* this (one for each direction) */
const u8 *updates[2];
/* Only ever replace with newer updates */
u32 update_timestamps[2];
};
struct pending_node_announce {
struct pubkey nodeid;
u8 *node_announcement;
u32 timestamp;
};
static const secp256k1_pubkey *
pending_node_announce_keyof(const struct pending_node_announce *a)
{
return &a->nodeid.pubkey;
}
static bool pending_node_announce_eq(const struct pending_node_announce *pna,
const secp256k1_pubkey *key)
{
return structeq(&pna->nodeid.pubkey, key);
}
HTABLE_DEFINE_TYPE(struct pending_node_announce, pending_node_announce_keyof,
node_map_hash_key, pending_node_announce_eq,
pending_node_map);
static struct node_map *empty_node_map(const tal_t *ctx)
{
struct node_map *map = tal(ctx, struct node_map);
node_map_init(map);
tal_add_destructor(map, node_map_clear);
return map;
}
struct routing_state *new_routing_state(const tal_t *ctx,
const struct bitcoin_blkid *chain_hash,
const struct pubkey *local_id,
u32 prune_timeout)
{
struct routing_state *rstate = tal(ctx, struct routing_state);
rstate->nodes = empty_node_map(rstate);
rstate->broadcasts = new_broadcast_state(rstate);
rstate->chain_hash = *chain_hash;
rstate->local_id = *local_id;
rstate->prune_timeout = prune_timeout;
rstate->store = gossip_store_new(rstate);
list_head_init(&rstate->pending_cannouncement);
uintmap_init(&rstate->chanmap);
rstate->pending_node_map = tal(ctx, struct pending_node_map);
pending_node_map_init(rstate->pending_node_map);
return rstate;
}
const secp256k1_pubkey *node_map_keyof_node(const struct node *n)
{
return &n->id.pubkey;
}
size_t node_map_hash_key(const secp256k1_pubkey *key)
{
return siphash24(siphash_seed(), key, sizeof(*key));
}
bool node_map_node_eq(const struct node *n, const secp256k1_pubkey *key)
{
return structeq(&n->id.pubkey, key);
}
static void destroy_node(struct node *node, struct routing_state *rstate)
{
node_map_del(rstate->nodes, node);
/* These remove themselves from the array. */
while (tal_count(node->chans))
tal_free(node->chans[0]);
}
struct node *get_node(struct routing_state *rstate, const struct pubkey *id)
{
return node_map_get(rstate->nodes, &id->pubkey);
}
static struct node *new_node(struct routing_state *rstate,
const struct pubkey *id)
{
struct node *n;
assert(!get_node(rstate, id));
n = tal(rstate, struct node);
n->id = *id;
n->chans = tal_arr(n, struct chan *, 0);
n->alias = NULL;
n->node_announce_msgidx = 0;
n->last_timestamp = -1;
n->addresses = tal_arr(n, struct wireaddr, 0);
node_map_add(rstate->nodes, n);
tal_add_destructor2(n, destroy_node, rstate);
return n;
}
static bool remove_channel_from_array(struct chan ***chans, struct chan *c)
{
size_t i, n;
n = tal_count(*chans);
for (i = 0; i < n; i++) {
if ((*chans)[i] != c)
continue;
n--;
memmove(*chans + i, *chans + i + 1, sizeof(**chans) * (n - i));
tal_resize(chans, n);
return true;
}
return false;
}
static void destroy_chan(struct chan *chan, struct routing_state *rstate)
{
if (!remove_channel_from_array(&chan->nodes[0]->chans, chan)
|| !remove_channel_from_array(&chan->nodes[1]->chans, chan))
/* FIXME! */
abort();
uintmap_del(&rstate->chanmap, chan->scid.u64);
if (tal_count(chan->nodes[0]->chans) == 0)
tal_free(chan->nodes[0]);
if (tal_count(chan->nodes[1]->chans) == 0)
tal_free(chan->nodes[1]);
}
static void init_half_chan(struct routing_state *rstate,
struct chan *chan,
int idx)
{
struct half_chan *c = &chan->half[idx];
c->channel_update_msgidx = 0;
c->unroutable_until = 0;
c->active = false;
c->flags = idx;
/* We haven't seen channel_update: make it halfway to prune time,
* which should be older than any update we'd see. */
c->last_timestamp = time_now().ts.tv_sec - rstate->prune_timeout/2;
}
struct chan *new_chan(struct routing_state *rstate,
const struct short_channel_id *scid,
const struct pubkey *id1,
const struct pubkey *id2)
{
struct chan *chan = tal(rstate, struct chan);
int n1idx = pubkey_idx(id1, id2);
size_t n;
struct node *n1, *n2;
/* We should never add a channel twice */
assert(!uintmap_get(&rstate->chanmap, scid->u64));
/* Create nodes on demand */
n1 = get_node(rstate, id1);
if (!n1)
n1 = new_node(rstate, id1);
n2 = get_node(rstate, id2);
if (!n2)
n2 = new_node(rstate, id2);
chan->scid = *scid;
chan->nodes[n1idx] = n1;
chan->nodes[!n1idx] = n2;
chan->txout_script = NULL;
chan->channel_announce_msgidx = 0;
chan->public = false;
chan->satoshis = 0;
n = tal_count(n2->chans);
tal_resize(&n2->chans, n+1);
n2->chans[n] = chan;
n = tal_count(n1->chans);
tal_resize(&n1->chans, n+1);
n1->chans[n] = chan;
/* Populate with (inactive) connections */
init_half_chan(rstate, chan, n1idx);
init_half_chan(rstate, chan, !n1idx);
uintmap_add(&rstate->chanmap, scid->u64, chan);
tal_add_destructor2(chan, destroy_chan, rstate);
return chan;
}
/* Too big to reach, but don't overflow if added. */
#define INFINITE 0x3FFFFFFFFFFFFFFFULL
static void clear_bfg(struct node_map *nodes)
{
struct node *n;
struct node_map_iter it;
for (n = node_map_first(nodes, &it); n; n = node_map_next(nodes, &it)) {
size_t i;
for (i = 0; i < ARRAY_SIZE(n->bfg); i++) {
n->bfg[i].total = INFINITE;
n->bfg[i].risk = 0;
}
}
}
static u64 connection_fee(const struct half_chan *c, u64 msatoshi)
{
u64 fee;
assert(msatoshi < MAX_MSATOSHI);
assert(c->proportional_fee < MAX_PROPORTIONAL_FEE);
fee = (c->proportional_fee * msatoshi) / 1000000;
/* This can't overflow: c->base_fee is a u32 */
return c->base_fee + fee;
}
/* Risk of passing through this channel. We insert a tiny constant here
* in order to prefer shorter routes, all things equal. */
static u64 risk_fee(u64 amount, u32 delay, double riskfactor)
{
return 1 + amount * delay * riskfactor;
}
/* We track totals, rather than costs. That's because the fee depends
* on the current amount passing through. */
static void bfg_one_edge(struct node *node,
struct chan *chan, int idx,
double riskfactor,
double fuzz, const struct siphash_seed *base_seed)
{
size_t h;
double fee_scale = 1.0;
const struct half_chan *c = &chan->half[idx];
if (fuzz != 0.0) {
u64 h = siphash24(base_seed, &chan->scid, sizeof(chan->scid));
/* Scale fees for this channel */
/* rand = (h / UINT64_MAX) random number between 0.0 -> 1.0
* 2*fuzz*rand random number between 0.0 -> 2*fuzz
* 2*fuzz*rand - fuzz random number between -fuzz -> +fuzz
*/
fee_scale = 1.0 + (2.0 * fuzz * h / UINT64_MAX) - fuzz;
}
for (h = 0; h < ROUTING_MAX_HOPS; h++) {
struct node *src;
/* FIXME: Bias against smaller channels. */
u64 fee;
u64 risk;
if (node->bfg[h].total == INFINITE)
continue;
fee = connection_fee(c, node->bfg[h].total) * fee_scale;
risk = node->bfg[h].risk + risk_fee(node->bfg[h].total + fee,
c->delay, riskfactor);
if (node->bfg[h].total + fee + risk >= MAX_MSATOSHI) {
SUPERVERBOSE("...extreme %"PRIu64
" + fee %"PRIu64
" + risk %"PRIu64" ignored",
node->bfg[h].total, fee, risk);
continue;
}
/* nodes[0] is src for connections[0] */
src = chan->nodes[idx];
if (node->bfg[h].total + fee + risk
< src->bfg[h+1].total + src->bfg[h+1].risk) {
SUPERVERBOSE("...%s can reach here in hoplen %zu total %"PRIu64,
type_to_string(trc, struct pubkey,
&src->id),
h, node->bfg[h].total + fee);
src->bfg[h+1].total = node->bfg[h].total + fee;
src->bfg[h+1].risk = risk;
src->bfg[h+1].prev = chan;
}
}
}
/* Determine if the given half_chan is routable */
static bool hc_is_routable(const struct half_chan *hc, time_t now)
{
return hc->active && hc->unroutable_until < now;
}
/* riskfactor is already scaled to per-block amount */
static struct chan **
find_route(const tal_t *ctx, struct routing_state *rstate,
const struct pubkey *from, const struct pubkey *to, u64 msatoshi,
double riskfactor,
double fuzz, const struct siphash_seed *base_seed,
u64 *fee)
{
struct chan **route;
struct node *n, *src, *dst;
struct node_map_iter it;
int runs, i, best;
/* Call time_now() once at the start, so that our tight loop
* does not keep calling into operating system for the
* current time */
time_t now = time_now().ts.tv_sec;
/* Note: we map backwards, since we know the amount of satoshi we want
* at the end, and need to derive how much we need to send. */
dst = get_node(rstate, from);
src = get_node(rstate, to);
if (!src) {
status_info("find_route: cannot find %s",
type_to_string(tmpctx, struct pubkey, to));
return NULL;
} else if (!dst) {
status_info("find_route: cannot find myself (%s)",
type_to_string(tmpctx, struct pubkey, to));
return NULL;
} else if (dst == src) {
status_info("find_route: this is %s, refusing to create empty route",
type_to_string(tmpctx, struct pubkey, to));
return NULL;
}
if (msatoshi >= MAX_MSATOSHI) {
status_info("find_route: can't route huge amount %"PRIu64,
msatoshi);
return NULL;
}
/* Reset all the information. */
clear_bfg(rstate->nodes);
/* Bellman-Ford-Gibson: like Bellman-Ford, but keep values for
* every path length. */
src->bfg[0].total = msatoshi;
src->bfg[0].risk = 0;
for (runs = 0; runs < ROUTING_MAX_HOPS; runs++) {
SUPERVERBOSE("Run %i", runs);
/* Run through every edge. */
for (n = node_map_first(rstate->nodes, &it);
n;
n = node_map_next(rstate->nodes, &it)) {
size_t num_edges = tal_count(n->chans);
for (i = 0; i < num_edges; i++) {
struct chan *chan = n->chans[i];
int idx = half_chan_to(n, chan);
SUPERVERBOSE("Node %s edge %i/%zu",
type_to_string(tmpctx, struct pubkey,
&n->id),
i, num_edges);
if (!hc_is_routable(&chan->half[idx], now)) {
SUPERVERBOSE("...unroutable");
continue;
}
bfg_one_edge(n, chan, idx,
riskfactor, fuzz, base_seed);
SUPERVERBOSE("...done");
}
}
}
best = 0;
for (i = 1; i <= ROUTING_MAX_HOPS; i++) {
if (dst->bfg[i].total < dst->bfg[best].total)
best = i;
}
/* No route? */
if (dst->bfg[best].total >= INFINITE) {
status_trace("find_route: No route to %s",
type_to_string(tmpctx, struct pubkey, to));
return NULL;
}
/* We (dst) don't charge ourselves fees, so skip first hop */
n = other_node(dst, dst->bfg[best].prev);
*fee = n->bfg[best-1].total - msatoshi;
/* Lay out route */
route = tal_arr(ctx, struct chan *, best);
for (i = 0, n = dst;
i < best;
n = other_node(n, n->bfg[best-i].prev), i++) {
route[i] = n->bfg[best-i].prev;
}
assert(n == src);
return route;
}
/* Verify the signature of a channel_update message */
static u8 *check_channel_update(const tal_t *ctx,
const struct pubkey *node_key,
const secp256k1_ecdsa_signature *node_sig,
const u8 *update)
{
/* 2 byte msg type + 64 byte signatures */
int offset = 66;
struct sha256_double hash;
sha256_double(&hash, update + offset, tal_len(update) - offset);
if (!check_signed_hash(&hash, node_sig, node_key))
return towire_errorfmt(ctx, NULL,
"Bad signature for %s hash %s"
" on channel_update %s",
type_to_string(ctx,
secp256k1_ecdsa_signature,
node_sig),
type_to_string(ctx,
struct sha256_double,
&hash),
tal_hex(ctx, update));
return NULL;
}
static u8 *check_channel_announcement(const tal_t *ctx,
const struct pubkey *node1_key, const struct pubkey *node2_key,
const struct pubkey *bitcoin1_key, const struct pubkey *bitcoin2_key,
const secp256k1_ecdsa_signature *node1_sig,
const secp256k1_ecdsa_signature *node2_sig,
const secp256k1_ecdsa_signature *bitcoin1_sig,
const secp256k1_ecdsa_signature *bitcoin2_sig, const u8 *announcement)
{
/* 2 byte msg type + 256 byte signatures */
int offset = 258;
struct sha256_double hash;
sha256_double(&hash, announcement + offset,
tal_len(announcement) - offset);
if (!check_signed_hash(&hash, node1_sig, node1_key)) {
return towire_errorfmt(ctx, NULL,
"Bad node_signature_1 %s hash %s"
" on node_announcement %s",
type_to_string(ctx,
secp256k1_ecdsa_signature,
node1_sig),
type_to_string(ctx,
struct sha256_double,
&hash),
tal_hex(ctx, announcement));
}
if (!check_signed_hash(&hash, node2_sig, node2_key)) {
return towire_errorfmt(ctx, NULL,
"Bad node_signature_2 %s hash %s"
" on node_announcement %s",
type_to_string(ctx,
secp256k1_ecdsa_signature,
node2_sig),
type_to_string(ctx,
struct sha256_double,
&hash),
tal_hex(ctx, announcement));
}
if (!check_signed_hash(&hash, bitcoin1_sig, bitcoin1_key)) {
return towire_errorfmt(ctx, NULL,
"Bad bitcoin_signature_1 %s hash %s"
" on node_announcement %s",
type_to_string(ctx,
secp256k1_ecdsa_signature,
bitcoin1_sig),
type_to_string(ctx,
struct sha256_double,
&hash),
tal_hex(ctx, announcement));
}
if (!check_signed_hash(&hash, bitcoin2_sig, bitcoin2_key)) {
return towire_errorfmt(ctx, NULL,
"Bad bitcoin_signature_2 %s hash %s"
" on node_announcement %s",
type_to_string(ctx,
secp256k1_ecdsa_signature,
bitcoin2_sig),
type_to_string(ctx,
struct sha256_double,
&hash),
tal_hex(ctx, announcement));
}
return NULL;
}
static void add_pending_node_announcement(struct routing_state *rstate, struct pubkey *nodeid)
{
struct pending_node_announce *pna = tal(rstate, struct pending_node_announce);
pna->nodeid = *nodeid;
pna->node_announcement = NULL;
pna->timestamp = 0;
pending_node_map_add(rstate->pending_node_map, pna);
}
static void process_pending_node_announcement(struct routing_state *rstate,
struct pubkey *nodeid)
{
struct pending_node_announce *pna = pending_node_map_get(rstate->pending_node_map, &nodeid->pubkey);
if (!pna)
return;
if (pna->node_announcement) {
u8 *err;
SUPERVERBOSE(
"Processing deferred node_announcement for node %s",
type_to_string(pna, struct pubkey, nodeid));
/* Should not error, since we processed it before */
err = handle_node_announcement(rstate, pna->node_announcement);
if (err)
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"pending node_announcement %s malformed %s?",
tal_hex(tmpctx, pna->node_announcement),
sanitize_error(tmpctx, err, NULL));
}
pending_node_map_del(rstate->pending_node_map, pna);
tal_free(pna);
}
static struct pending_cannouncement *
find_pending_cannouncement(struct routing_state *rstate,
const struct short_channel_id *scid)
{
struct pending_cannouncement *i;
list_for_each(&rstate->pending_cannouncement, i, list) {
if (structeq(scid, &i->short_channel_id))
return i;
}
return NULL;
}
static void destroy_pending_cannouncement(struct pending_cannouncement *pending,
struct routing_state *rstate)
{
list_del_from(&rstate->pending_cannouncement, &pending->list);
}
bool routing_add_channel_announcement(struct routing_state *rstate,
const u8 *msg TAKES, u64 satoshis)
{
struct chan *chan;
secp256k1_ecdsa_signature node_signature_1, node_signature_2;
secp256k1_ecdsa_signature bitcoin_signature_1, bitcoin_signature_2;
u8 *features;
struct bitcoin_blkid chain_hash;
struct short_channel_id scid;
struct pubkey node_id_1;
struct pubkey node_id_2;
struct pubkey bitcoin_key_1;
struct pubkey bitcoin_key_2;
bool old_chan, old_public;
u64 old_msgidx;
fromwire_channel_announcement(
tmpctx, msg, &node_signature_1, &node_signature_2,
&bitcoin_signature_1, &bitcoin_signature_2, &features, &chain_hash,
&scid, &node_id_1, &node_id_2, &bitcoin_key_1, &bitcoin_key_2);
/* The channel may already exist if it was non-public from
* local_add_channel(); normally we don't accept new
* channel_announcements. See handle_channel_announcement. */
chan = get_channel(rstate, &scid);
old_chan = chan;
if (!chan)
chan = new_chan(rstate, &scid, &node_id_1, &node_id_2);
old_public = chan->public;
old_msgidx = chan->channel_announce_msgidx;
/* Channel is now public. */
chan->public = true;
chan->satoshis = satoshis;
if (replace_broadcast(chan, rstate->broadcasts,
&chan->channel_announce_msgidx, msg)) {
status_broken("Announcement %s was replaced: %s, %s, msgidx was %"PRIu64" now %"PRIu64"?",
tal_hex(tmpctx, msg),
old_chan ? "preexisting" : "new channel",
old_public ? "public" : "not public",
old_msgidx, chan->channel_announce_msgidx);
return false;
}
return true;
}
u8 *handle_channel_announcement(struct routing_state *rstate,
const u8 *announce TAKES,
const struct short_channel_id **scid)
{
struct pending_cannouncement *pending;
struct bitcoin_blkid chain_hash;
u8 *features, *err;
secp256k1_ecdsa_signature node_signature_1, node_signature_2;
secp256k1_ecdsa_signature bitcoin_signature_1, bitcoin_signature_2;
struct chan *chan;
pending = tal(rstate, struct pending_cannouncement);
pending->updates[0] = NULL;
pending->updates[1] = NULL;
pending->announce = tal_dup_arr(pending, u8,
announce, tal_len(announce), 0);
pending->update_timestamps[0] = pending->update_timestamps[1] = 0;
if (!fromwire_channel_announcement(pending, pending->announce,
&node_signature_1,
&node_signature_2,
&bitcoin_signature_1,
&bitcoin_signature_2,
&features,
&chain_hash,
&pending->short_channel_id,
&pending->node_id_1,
&pending->node_id_2,
&pending->bitcoin_key_1,
&pending->bitcoin_key_2)) {
err = towire_errorfmt(rstate, NULL,
"Malformed channel_announcement %s",
tal_hex(pending, pending->announce));
goto malformed;
}
/* Check if we know the channel already (no matter in what
* state, we stop here if yes). */
chan = get_channel(rstate, &pending->short_channel_id);
if (chan != NULL && chan->public) {
SUPERVERBOSE("%s: %s already has public channel",
__func__,
type_to_string(tmpctx, struct short_channel_id,
&pending->short_channel_id));
goto ignored;
}
/* We don't replace previous ones, since we might validate that and
* think this one is OK! */
if (find_pending_cannouncement(rstate, &pending->short_channel_id)) {
SUPERVERBOSE("%s: %s already has pending cannouncement",
__func__,
type_to_string(tmpctx, struct short_channel_id,
&pending->short_channel_id));
goto ignored;
}
/* FIXME: Handle duplicates as per BOLT #7 */
/* BOLT #7:
*
* If there is an unknown even bit in the `features` field the
* receiving node MUST NOT parse the remainder of the message
* and MUST NOT add the channel to its local network view, and
* SHOULD NOT forward the announcement.
*/
if (!features_supported(features, NULL)) {
status_trace("Ignoring channel announcement, unsupported features %s.",
tal_hex(pending, features));
goto ignored;
}
/* BOLT #7:
*
* The receiving node MUST ignore the message if the specified
* `chain_hash` is unknown to the receiver.
*/
if (!structeq(&chain_hash, &rstate->chain_hash)) {
status_trace(
"Received channel_announcement %s for unknown chain %s",
type_to_string(pending, struct short_channel_id,
&pending->short_channel_id),
type_to_string(pending, struct bitcoin_blkid, &chain_hash));
goto ignored;
}
err = check_channel_announcement(rstate,
&pending->node_id_1,
&pending->node_id_2,
&pending->bitcoin_key_1,
&pending->bitcoin_key_2,
&node_signature_1,
&node_signature_2,
&bitcoin_signature_1,
&bitcoin_signature_2,
pending->announce);
if (err) {
/* BOLT #7:
*
* - if `bitcoin_signature_1`, `bitcoin_signature_2`,
* `node_signature_1` OR `node_signature_2` are invalid OR NOT
* correct:
* - SHOULD fail the connection.
*/
goto malformed;
}
status_trace("Received channel_announcement for channel %s",
type_to_string(pending, struct short_channel_id,
&pending->short_channel_id));
/* Add both endpoints to the pending_node_map so we can stash
* node_announcements while we wait for the txout check */
add_pending_node_announcement(rstate, &pending->node_id_1);
add_pending_node_announcement(rstate, &pending->node_id_2);
list_add_tail(&rstate->pending_cannouncement, &pending->list);
tal_add_destructor2(pending, destroy_pending_cannouncement, rstate);
/* Success */
*scid = &pending->short_channel_id;
return NULL;
malformed:
tal_free(pending);
*scid = NULL;
return err;
ignored:
tal_free(pending);
*scid = NULL;
return NULL;
}
static void process_pending_channel_update(struct routing_state *rstate,
const struct short_channel_id *scid,
const u8 *cupdate)
{
u8 *err;
if (!cupdate)
return;
/* FIXME: We don't remember who sent us updates, so can't error them */
err = handle_channel_update(rstate, cupdate);
if (err) {
status_trace("Pending channel_update for %s: %s",
type_to_string(tmpctx, struct short_channel_id, scid),
sanitize_error(tmpctx, err, NULL));
tal_free(err);
}
}
bool handle_pending_cannouncement(struct routing_state *rstate,
const struct short_channel_id *scid,
const u64 satoshis,
const u8 *outscript)
{
bool local;
const u8 *s;
struct pending_cannouncement *pending;
pending = find_pending_cannouncement(rstate, scid);
if (!pending)
return false;
/* BOLT #7:
*
* The receiving node MUST ignore the message if this output is spent.
*/
if (tal_len(outscript) == 0) {
status_trace("channel_announcement: no unspent txout %s",
type_to_string(pending, struct short_channel_id,
scid));
tal_free(pending);
return false;
}
/* BOLT #7:
*
* The receiving node MUST ignore the message if the output
* specified by `short_channel_id` does not correspond to a
* P2WSH using `bitcoin_key_1` and `bitcoin_key_2` as
* specified in [BOLT
* #3](03-transactions.md#funding-transaction-output).
*/
s = scriptpubkey_p2wsh(pending,
bitcoin_redeem_2of2(pending,
&pending->bitcoin_key_1,
&pending->bitcoin_key_2));
if (!scripteq(s, outscript)) {
status_trace("channel_announcement: txout %s expectes %s, got %s",
type_to_string(pending, struct short_channel_id,
scid),
tal_hex(tmpctx, s), tal_hex(tmpctx, outscript));
tal_free(pending);
return false;
}
if (!routing_add_channel_announcement(rstate, pending->announce, satoshis))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Could not add channel_announcement");
gossip_store_add_channel_announcement(rstate->store, pending->announce, satoshis);
local = pubkey_eq(&pending->node_id_1, &rstate->local_id) ||
pubkey_eq(&pending->node_id_2, &rstate->local_id);
/* Did we have an update waiting? If so, apply now. */
process_pending_channel_update(rstate, scid, pending->updates[0]);
process_pending_channel_update(rstate, scid, pending->updates[1]);
process_pending_node_announcement(rstate, &pending->node_id_1);
process_pending_node_announcement(rstate, &pending->node_id_2);
tal_free(pending);
return local;
}
static void update_pending(struct pending_cannouncement *pending,
u32 timestamp, const u8 *update,
const u8 direction)
{
SUPERVERBOSE("Deferring update for pending channel %s(%d)",
type_to_string(tmpctx, struct short_channel_id,
&pending->short_channel_id), direction);
if (pending->update_timestamps[direction] < timestamp) {
if (pending->updates[direction]) {
status_trace("Replacing existing update");
tal_free(pending->updates[direction]);
}
pending->updates[direction] = tal_dup_arr(pending, u8, update, tal_len(update), 0);
pending->update_timestamps[direction] = timestamp;
}
}
void set_connection_values(struct chan *chan,
int idx,
u32 base_fee,
u32 proportional_fee,
u32 delay,
bool active,
u64 timestamp,
u32 htlc_minimum_msat)
{
struct half_chan *c = &chan->half[idx];
c->delay = delay;
c->htlc_minimum_msat = htlc_minimum_msat;
c->base_fee = base_fee;
c->proportional_fee = proportional_fee;
c->active = active;
c->last_timestamp = timestamp;
assert((c->flags & 0x1) == idx);
/* If it was temporarily unroutable, re-enable */
c->unroutable_until = 0;
SUPERVERBOSE("Channel %s(%d) was updated.",
type_to_string(tmpctx, struct short_channel_id, &chan->scid),
idx);
if (c->proportional_fee >= MAX_PROPORTIONAL_FEE) {
status_trace("Channel %s(%d) massive proportional fee %u:"
" disabling.",
type_to_string(tmpctx, struct short_channel_id,
&chan->scid),
idx,
c->proportional_fee);
c->active = false;
}
}
bool routing_add_channel_update(struct routing_state *rstate,
const u8 *update TAKES)
{
secp256k1_ecdsa_signature signature;
struct short_channel_id short_channel_id;
u32 timestamp;
u16 flags;
u16 expiry;
u64 htlc_minimum_msat;
u32 fee_base_msat;
u32 fee_proportional_millionths;
struct bitcoin_blkid chain_hash;
struct chan *chan;
u8 direction;
if (!fromwire_channel_update(update, &signature, &chain_hash,
&short_channel_id, &timestamp, &flags,
&expiry, &htlc_minimum_msat, &fee_base_msat,
&fee_proportional_millionths))
return false;
chan = get_channel(rstate, &short_channel_id);
if (!chan)
return false;
direction = flags & 0x1;
set_connection_values(chan, direction, fee_base_msat,
fee_proportional_millionths, expiry,
(flags & ROUTING_FLAGS_DISABLED) == 0, timestamp,
htlc_minimum_msat);
replace_broadcast(chan, rstate->broadcasts,
&chan->half[direction].channel_update_msgidx,
update);
return true;
}
u8 *handle_channel_update(struct routing_state *rstate, const u8 *update)
{
u8 *serialized;
struct half_chan *c;
secp256k1_ecdsa_signature signature;
struct short_channel_id short_channel_id;
u32 timestamp;
u16 flags;
u16 expiry;
u64 htlc_minimum_msat;
u32 fee_base_msat;
u32 fee_proportional_millionths;
struct bitcoin_blkid chain_hash;
struct chan *chan;
u8 direction;
size_t len = tal_len(update);
u8 *err;
serialized = tal_dup_arr(tmpctx, u8, update, len, 0);
if (!fromwire_channel_update(serialized, &signature,
&chain_hash, &short_channel_id,
&timestamp, &flags, &expiry,
&htlc_minimum_msat, &fee_base_msat,
&fee_proportional_millionths)) {
err = towire_errorfmt(rstate, NULL,
"Malformed channel_update %s",
tal_hex(tmpctx, serialized));
return err;
}
direction = flags & 0x1;
/* BOLT #7:
*
* The receiving node MUST ignore the channel update if the specified
* `chain_hash` value is unknown, meaning it isn't active on the
* specified chain. */
if (!structeq(&chain_hash, &rstate->chain_hash)) {
status_trace("Received channel_update for unknown chain %s",
type_to_string(tmpctx, struct bitcoin_blkid,
&chain_hash));
return NULL;
}
chan = get_channel(rstate, &short_channel_id);
/* Optimization: only check for pending if not public */
if (!chan || !chan->public) {
struct pending_cannouncement *pending;
pending = find_pending_cannouncement(rstate, &short_channel_id);
if (pending) {
update_pending(pending,
timestamp, serialized, direction);
return NULL;
}
if (!chan) {
SUPERVERBOSE("Ignoring update for unknown channel %s",
type_to_string(tmpctx, struct short_channel_id,
&short_channel_id));
return NULL;
}
}
c = &chan->half[direction];
if (c->last_timestamp >= timestamp) {
SUPERVERBOSE("Ignoring outdated update.");
return NULL;
}
err = check_channel_update(rstate, &chan->nodes[direction]->id,
&signature, serialized);
if (err) {
/* BOLT #7:
*
* - if `signature` is not a valid signature, using `node_id`
* of the double-SHA256 of the entire message following the
* `signature` field (including unknown fields following
* `fee_proportional_millionths`):
* - MUST NOT process the message further.
* - SHOULD fail the connection.
*/
return err;
}
status_trace("Received channel_update for channel %s(%d) now %s",
type_to_string(tmpctx, struct short_channel_id,
&short_channel_id),
flags & 0x01,
flags & ROUTING_FLAGS_DISABLED ? "DISABLED" : "ACTIVE");
if (!routing_add_channel_update(rstate, serialized))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Failed adding channel_update");
/* Store the channel_update for both public and non-public channels
* (non-public ones may just be the incoming direction). We'd have
* dropped invalid ones earlier. */
gossip_store_add_channel_update(rstate->store, serialized);
return NULL;
}
static struct wireaddr *read_addresses(const tal_t *ctx, const u8 *ser)
{
const u8 *cursor = ser;
size_t max = tal_len(ser);
struct wireaddr *wireaddrs = tal_arr(ctx, struct wireaddr, 0);
int numaddrs = 0;
while (cursor && cursor < ser + max) {
struct wireaddr wireaddr;
/* Skip any padding */
while (max && cursor[0] == ADDR_TYPE_PADDING)
fromwire_u8(&cursor, &max);
/* BOLT #7:
*
* The receiving node SHOULD ignore the first `address
* descriptor` which does not match the types defined
* above.
*/
if (!fromwire_wireaddr(&cursor, &max, &wireaddr)) {
if (!cursor)
/* Parsing address failed */
return tal_free(wireaddrs);
/* Unknown type, stop there. */
break;
}
tal_resize(&wireaddrs, numaddrs+1);
wireaddrs[numaddrs] = wireaddr;
numaddrs++;
}
return wireaddrs;
}
bool routing_add_node_announcement(struct routing_state *rstate, const u8 *msg TAKES)
{
struct node *node;
secp256k1_ecdsa_signature signature;
u32 timestamp;
struct pubkey node_id;
u8 rgb_color[3];
u8 alias[32];
u8 *features, *addresses;
struct wireaddr *wireaddrs;
fromwire_node_announcement(tmpctx, msg,
&signature, &features, &timestamp,
&node_id, rgb_color, alias,
&addresses);
node = get_node(rstate, &node_id);
/* May happen if we accepted the node_announcement due to a local
* channel, for which we didn't have the announcement hust yet. */
if (node == NULL)
return false;
wireaddrs = read_addresses(tmpctx, addresses);
tal_free(node->addresses);
node->addresses = tal_steal(node, wireaddrs);
node->last_timestamp = timestamp;
memcpy(node->rgb_color, rgb_color, 3);
tal_free(node->alias);
node->alias = tal_dup_arr(node, u8, alias, 32, 0);
replace_broadcast(node, rstate->broadcasts,
&node->node_announce_msgidx,
msg);
return true;
}
static bool node_has_public_channels(struct node *node)
{
for (size_t i = 0; i < tal_count(node->chans); i++)
if (node->chans[i]->public)
return true;
return false;
}
u8 *handle_node_announcement(struct routing_state *rstate, const u8 *node_ann)
{
u8 *serialized;
struct sha256_double hash;
struct node *node;
secp256k1_ecdsa_signature signature;
u32 timestamp;
struct pubkey node_id;
u8 rgb_color[3];
u8 alias[32];
u8 *features, *addresses;
struct wireaddr *wireaddrs;
struct pending_node_announce *pna;
size_t len = tal_len(node_ann);
bool applied;
serialized = tal_dup_arr(tmpctx, u8, node_ann, len, 0);
if (!fromwire_node_announcement(tmpctx, serialized,
&signature, &features, &timestamp,
&node_id, rgb_color, alias,
&addresses)) {
/* BOLT #7:
*
* - if `node_id` is NOT a valid compressed public key:
* - SHOULD fail the connection.
* - MUST NOT process the message further.
*/
u8 *err = towire_errorfmt(rstate, NULL,
"Malformed node_announcement %s",
tal_hex(tmpctx, node_ann));
return err;
}
/* BOLT #7:
*
* If the `features` field contains unknown even bits the
* receiving node MUST NOT parse the remainder of the message
* and MAY discard the message altogether.
*/
if (!features_supported(features, NULL)) {
status_trace("Ignoring node announcement for node %s, unsupported features %s.",
type_to_string(tmpctx, struct pubkey, &node_id),
tal_hex(tmpctx, features));
return NULL;
}
sha256_double(&hash, serialized + 66, tal_count(serialized) - 66);
if (!check_signed_hash(&hash, &signature, &node_id)) {
/* BOLT #7:
*
* - if `signature` is NOT a valid signature (using `node_id`
* of the double-SHA256 of the entire message following the
* `signature` field, including unknown fields following
* `alias`):
* - SHOULD fail the connection.
* - MUST NOT process the message further.
*/
u8 *err = towire_errorfmt(rstate, NULL,
"Bad signature for %s hash %s"
" on node_announcement %s",
type_to_string(tmpctx,
secp256k1_ecdsa_signature,
&signature),
type_to_string(tmpctx,
struct sha256_double,
&hash),
tal_hex(tmpctx, node_ann));
return err;
}
wireaddrs = read_addresses(tmpctx, addresses);
if (!wireaddrs) {
/* BOLT #7:
*
* - if `addrlen` is insufficient to hold the address
* descriptors of the known types:
* - SHOULD fail the connection.
*/
u8 *err = towire_errorfmt(rstate, NULL,
"Malformed wireaddrs %s in %s.",
tal_hex(tmpctx, wireaddrs),
tal_hex(tmpctx, node_ann));
return err;
}
/* Beyond this point it's not malformed, so safe if we make it
* pending and requeue later. */
node = get_node(rstate, &node_id);
/* BOLT #7:
*
* - if `node_id` is NOT previously known from a `channel_announcement`
* message, OR if `timestamp` is NOT greater than the last-received
* `node_announcement` from this `node_id`:
* - SHOULD ignore the message.
*/
if (!node || !node_has_public_channels(node)) {
/* Check if we are currently verifying the txout for a
* matching channel */
pna = pending_node_map_get(rstate->pending_node_map,
&node_id.pubkey);
if (!pna) {
SUPERVERBOSE("Node not found, was the node_announcement "
"for node %s preceded by at least "
"channel_announcement?",
type_to_string(tmpctx, struct pubkey,
&node_id));
} else if (pna->timestamp < timestamp) {
SUPERVERBOSE(
"Deferring node_announcement for node %s",
type_to_string(tmpctx, struct pubkey, &node_id));
pna->timestamp = timestamp;
tal_free(pna->node_announcement);
pna->node_announcement = tal_dup_arr(pna, u8, node_ann,
tal_len(node_ann),
0);
}
return NULL;
}
if (node->last_timestamp >= timestamp) {
SUPERVERBOSE("Ignoring node announcement, it's outdated.");
return NULL;
}
status_trace("Received node_announcement for node %s",
type_to_string(tmpctx, struct pubkey, &node_id));
applied = routing_add_node_announcement(rstate, serialized);
assert(applied);
gossip_store_add_node_announcement(rstate->store, serialized);
return NULL;
}
struct route_hop *get_route(const tal_t *ctx, struct routing_state *rstate,
const struct pubkey *source,
const struct pubkey *destination,
const u64 msatoshi, double riskfactor,
u32 final_cltv,
double fuzz, const struct siphash_seed *base_seed)
{
struct chan **route;
u64 total_amount;
unsigned int total_delay;
u64 fee;
struct route_hop *hops;
int i;
struct node *n;
route = find_route(ctx, rstate, source, destination, msatoshi,
riskfactor / BLOCKS_PER_YEAR / 10000,
fuzz, base_seed, &fee);
if (!route) {
return NULL;
}
/* Fees, delays need to be calculated backwards along route. */
hops = tal_arr(ctx, struct route_hop, tal_count(route));
total_amount = msatoshi;
total_delay = final_cltv;
/* Start at destination node. */
n = get_node(rstate, destination);
for (i = tal_count(route) - 1; i >= 0; i--) {
const struct half_chan *c;
int idx = half_chan_to(n, route[i]);
c = &route[i]->half[idx];
hops[i].channel_id = route[i]->scid;
hops[i].nodeid = n->id;
hops[i].amount = total_amount;
hops[i].delay = total_delay;
total_amount += connection_fee(c, total_amount);
total_delay += c->delay;
n = other_node(n, route[i]);
}
assert(pubkey_eq(&n->id, source));
/* FIXME: Shadow route! */
return hops;
}
/**
* routing_failure_channel_out - Handle routing failure on a specific channel
*
* If we want to delete the channel, we reparent it to disposal_context.
*/
static void routing_failure_channel_out(const tal_t *disposal_context,
struct node *node,
enum onion_type failcode,
struct chan *chan,
time_t now)
{
struct half_chan *hc = half_chan_from(node, chan);
/* BOLT #4:
*
* - if the PERM bit is NOT set:
* - SHOULD restore the channels as it receives new `channel_update`s.
*/
if (!(failcode & PERM))
/* Prevent it for 20 seconds. */
hc->unroutable_until = now + 20;
else
/* Set it up to be pruned. */
tal_steal(disposal_context, chan);
}
void routing_failure(struct routing_state *rstate,
const struct pubkey *erring_node_pubkey,
const struct short_channel_id *scid,
enum onion_type failcode,
const u8 *channel_update)
{
struct node *node;
time_t now = time_now().ts.tv_sec;
status_trace("Received routing failure 0x%04x (%s), "
"erring node %s, "
"channel %s",
(int) failcode, onion_type_name(failcode),
type_to_string(tmpctx, struct pubkey, erring_node_pubkey),
type_to_string(tmpctx, struct short_channel_id, scid));
node = get_node(rstate, erring_node_pubkey);
if (!node) {
status_unusual("routing_failure: Erring node %s not in map",
type_to_string(tmpctx, struct pubkey,
erring_node_pubkey));
/* No node, so no channel, so any channel_update
* can also be ignored. */
return;
}
/* BOLT #4:
*
* - if the NODE bit is set:
* - SHOULD remove all channels connected with the erring node from
* consideration.
*
*/
if (failcode & NODE) {
for (int i = 0; i < tal_count(node->chans); ++i) {
routing_failure_channel_out(tmpctx, node, failcode,
node->chans[i],
now);
}
} else {
struct chan *chan = get_channel(rstate, scid);
if (!chan)
status_unusual("routing_failure: "
"Channel %s unknown",
type_to_string(tmpctx,
struct short_channel_id,
scid));
else if (chan->nodes[0] != node && chan->nodes[1] != node)
status_unusual("routing_failure: "
"Channel %s does not connect to %s",
type_to_string(tmpctx,
struct short_channel_id,
scid),
type_to_string(tmpctx, struct pubkey,
erring_node_pubkey));
else
routing_failure_channel_out(tmpctx,
node, failcode, chan, now);
}
/* Update the channel if UPDATE failcode. Do
* this after deactivating, so that if the
* channel_update is newer it will be
* reactivated. */
if (failcode & UPDATE) {
u8 *err;
if (tal_len(channel_update) == 0) {
/* Suppress UNUSUAL log if local failure */
if (structeq(&erring_node_pubkey->pubkey,
&rstate->local_id.pubkey))
return;
status_unusual("routing_failure: "
"UPDATE bit set, no channel_update. "
"failcode: 0x%04x",
(int) failcode);
return;
}
err = handle_channel_update(rstate, channel_update);
if (err) {
status_unusual("routing_failure: "
"bad channel_update %s",
sanitize_error(err, err, NULL));
tal_free(err);
return;
}
} else {
if (tal_len(channel_update) != 0)
status_unusual("routing_failure: "
"UPDATE bit clear, channel_update given. "
"failcode: 0x%04x",
(int) failcode);
}
}
void mark_channel_unroutable(struct routing_state *rstate,
const struct short_channel_id *channel)
{
struct chan *chan;
time_t now = time_now().ts.tv_sec;
const char *scid = type_to_string(tmpctx, struct short_channel_id,
channel);
status_trace("Received mark_channel_unroutable channel %s",
scid);
chan = get_channel(rstate, channel);
if (!chan) {
status_unusual("mark_channel_unroutable: "
"channel %s not in routemap",
scid);
return;
}
chan->half[0].unroutable_until = now + 20;
chan->half[1].unroutable_until = now + 20;
}
void route_prune(struct routing_state *rstate)
{
u64 now = time_now().ts.tv_sec;
/* Anything below this highwater mark ought to be pruned */
const s64 highwater = now - rstate->prune_timeout;
const tal_t *pruned = tal(NULL, char);
struct chan *chan;
u64 idx;
/* Now iterate through all channels and see if it is still alive */
for (chan = uintmap_first(&rstate->chanmap, &idx);
chan;
chan = uintmap_after(&rstate->chanmap, &idx)) {
/* Local-only? Don't prune. */
if (!chan->public)
continue;
if (chan->half[0].last_timestamp < highwater
&& chan->half[1].last_timestamp < highwater) {
status_trace(
"Pruning channel %s from network view (ages %"PRIu64" and %"PRIu64"s)",
type_to_string(tmpctx, struct short_channel_id,
&chan->scid),
now - chan->half[0].last_timestamp,
now - chan->half[1].last_timestamp);
/* This may perturb iteration so do outside loop. */
tal_steal(pruned, chan);
}
}
/* This frees all the chans and maybe even nodes. */
tal_free(pruned);
}
void handle_local_add_channel(struct routing_state *rstate, u8 *msg)
{
struct short_channel_id scid;
struct bitcoin_blkid chain_hash;
struct pubkey remote_node_id;
u16 cltv_expiry_delta;
u32 fee_base_msat, fee_proportional_millionths;
u64 htlc_minimum_msat;
int idx;
struct chan *chan;
if (!fromwire_gossip_local_add_channel(
msg, &scid, &chain_hash, &remote_node_id,
&cltv_expiry_delta, &htlc_minimum_msat, &fee_base_msat,
&fee_proportional_millionths)) {
status_broken("Unable to parse local_add_channel message: %s", tal_hex(msg, msg));
return;
}
if (!structeq(&chain_hash, &rstate->chain_hash)) {
status_broken("Received local_add_channel for unknown chain %s",
type_to_string(msg, struct bitcoin_blkid,
&chain_hash));
return;
}
/* Can happen on channeld restart. */
if (get_channel(rstate, &scid)) {
status_trace("Attempted to local_add_channel a known channel");
return;
}
/* Create new channel */
chan = new_chan(rstate, &scid, &rstate->local_id, &remote_node_id);
idx = pubkey_idx(&rstate->local_id, &remote_node_id),
/* Activate the half_chan from us to them. */
set_connection_values(chan, idx,
fee_base_msat,
fee_proportional_millionths,
cltv_expiry_delta,
true,
0,
htlc_minimum_msat);
/* Designed to match msg in handle_channel_update, for easy testing */
status_trace("Received local update for channel %s(%d) now ACTIVE",
type_to_string(msg, struct short_channel_id, &scid),
idx);
}