rgb-cln/lightningd/chaintopology.c

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#include "bitcoin/block.h"
#include "bitcoin/feerate.h"
#include "bitcoin/script.h"
#include "bitcoin/tx.h"
#include "bitcoind.h"
#include "chaintopology.h"
#include "jsonrpc.h"
#include "lightningd.h"
#include "log.h"
#include "watch.h"
#include <ccan/array_size/array_size.h>
#include <ccan/asort/asort.h>
#include <ccan/build_assert/build_assert.h>
#include <ccan/io/io.h>
#include <ccan/tal/str/str.h>
#include <common/memleak.h>
#include <common/timeout.h>
#include <common/utils.h>
#include <inttypes.h>
#include <lightningd/channel_control.h>
#include <lightningd/gossip_control.h>
#include <lightningd/json.h>
#include <lightningd/param.h>
/* Mutual recursion via timer. */
static void try_extend_tip(struct chain_topology *topo);
/* get_init_blockhash sets topo->root, start_fee_estimate clears
* feerate_uninitialized (even if unsuccessful) */
static void maybe_completed_init(struct chain_topology *topo)
{
if (topo->feerate_uninitialized)
return;
if (!topo->root)
return;
io_break(topo);
}
static void next_topology_timer(struct chain_topology *topo)
{
/* This takes care of its own lifetime. */
notleak(new_reltimer(topo->timers, topo,
time_from_sec(topo->poll_seconds),
try_extend_tip, topo));
}
static bool we_broadcast(const struct chain_topology *topo,
const struct bitcoin_txid *txid)
{
const struct outgoing_tx *otx;
list_for_each(&topo->outgoing_txs, otx, list) {
if (bitcoin_txid_eq(&otx->txid, txid))
return true;
}
return false;
}
static void filter_block_txs(struct chain_topology *topo, struct block *b)
{
size_t i;
u64 satoshi_owned;
/* Now we see if any of those txs are interesting. */
for (i = 0; i < tal_count(b->full_txs); i++) {
const struct bitcoin_tx *tx = b->full_txs[i];
struct bitcoin_txid txid;
size_t j;
/* Tell them if it spends a txo we care about. */
for (j = 0; j < tal_count(tx->input); j++) {
struct txwatch_output out;
struct txowatch *txo;
out.txid = tx->input[j].txid;
out.index = tx->input[j].index;
txo = txowatch_hash_get(&topo->txowatches, &out);
if (txo) {
wallet_transaction_add(topo->wallet, tx, b->height, i);
txowatch_fire(txo, tx, j, b);
}
}
satoshi_owned = 0;
if (txfilter_match(topo->bitcoind->ld->owned_txfilter, tx)) {
wallet_extract_owned_outputs(topo->bitcoind->ld->wallet,
tx, &b->height,
&satoshi_owned);
}
/* We did spends first, in case that tells us to watch tx. */
bitcoin_txid(tx, &txid);
if (watching_txid(topo, &txid) || we_broadcast(topo, &txid) ||
satoshi_owned != 0) {
wallet_transaction_add(topo->wallet, tx, b->height, i);
}
}
b->full_txs = tal_free(b->full_txs);
}
size_t get_tx_depth(const struct chain_topology *topo,
const struct bitcoin_txid *txid)
{
u32 blockheight = wallet_transaction_height(topo->wallet, txid);
if (blockheight == 0)
return 0;
return topo->tip->height - blockheight + 1;
}
struct txs_to_broadcast {
/* We just sent txs[cursor] */
size_t cursor;
/* These are hex encoded already, for bitcoind_sendrawtx */
const char **txs;
/* Command to complete when we're done, if and only if dev-broadcast triggered */
struct command *cmd;
};
/* We just sent the last entry in txs[]. Shrink and send the next last. */
static void broadcast_remainder(struct bitcoind *bitcoind,
int exitstatus, const char *msg,
struct txs_to_broadcast *txs)
{
/* These are expected. */
if (strstr(msg, "txn-mempool-conflict")
|| strstr(msg, "transaction already in block chain"))
log_debug(bitcoind->log,
"Expected error broadcasting tx %s: %s",
txs->txs[txs->cursor], msg);
else if (exitstatus)
log_unusual(bitcoind->log, "Broadcasting tx %s: %i %s",
txs->txs[txs->cursor], exitstatus, msg);
txs->cursor++;
if (txs->cursor == tal_count(txs->txs)) {
if (txs->cmd)
command_success(txs->cmd, null_response(txs->cmd));
tal_free(txs);
return;
}
/* Broadcast next one. */
bitcoind_sendrawtx(bitcoind, txs->txs[txs->cursor],
broadcast_remainder, txs);
}
/* FIXME: This is dumb. We can group txs and avoid bothering bitcoind
* if any one tx is in the main chain. */
static void rebroadcast_txs(struct chain_topology *topo, struct command *cmd)
{
/* Copy txs now (peers may go away, and they own txs). */
size_t num_txs = 0;
struct txs_to_broadcast *txs;
struct outgoing_tx *otx;
txs = tal(topo, struct txs_to_broadcast);
txs->cmd = cmd;
/* Put any txs we want to broadcast in ->txs. */
txs->txs = tal_arr(txs, const char *, 0);
list_for_each(&topo->outgoing_txs, otx, list) {
if (wallet_transaction_height(topo->wallet, &otx->txid))
continue;
tal_resize(&txs->txs, num_txs+1);
txs->txs[num_txs] = tal_strdup(txs, otx->hextx);
num_txs++;
}
/* Let this do the dirty work. */
txs->cursor = (size_t)-1;
broadcast_remainder(topo->bitcoind, 0, "", txs);
}
static void destroy_outgoing_tx(struct outgoing_tx *otx)
{
list_del(&otx->list);
}
static void clear_otx_channel(struct channel *channel, struct outgoing_tx *otx)
{
if (otx->channel != channel)
fatal("channel %p, otx %p has channel %p", channel, otx, otx->channel);
otx->channel = NULL;
}
static void broadcast_done(struct bitcoind *bitcoind,
int exitstatus, const char *msg,
struct outgoing_tx *otx)
{
/* Channel gone? Stop. */
if (!otx->channel) {
tal_free(otx);
return;
}
/* No longer needs to be disconnected if channel dies. */
tal_del_destructor2(otx->channel, clear_otx_channel, otx);
if (otx->failed && exitstatus != 0) {
otx->failed(otx->channel, exitstatus, msg);
tal_free(otx);
} else {
/* For continual rebroadcasting, until channel freed. */
tal_steal(otx->channel, otx);
list_add_tail(&bitcoind->ld->topology->outgoing_txs, &otx->list);
tal_add_destructor(otx, destroy_outgoing_tx);
}
}
void broadcast_tx(struct chain_topology *topo,
struct channel *channel, const struct bitcoin_tx *tx,
void (*failed)(struct channel *channel,
int exitstatus, const char *err))
{
/* Channel might vanish: topo owns it to start with. */
struct outgoing_tx *otx = tal(topo, struct outgoing_tx);
const u8 *rawtx = linearize_tx(otx, tx);
otx->channel = channel;
bitcoin_txid(tx, &otx->txid);
otx->hextx = tal_hex(otx, rawtx);
otx->failed = failed;
tal_free(rawtx);
tal_add_destructor2(channel, clear_otx_channel, otx);
log_add(topo->log, " (tx %s)",
type_to_string(tmpctx, struct bitcoin_txid, &otx->txid));
wallet_transaction_add(topo->wallet, tx, 0, 0);
bitcoind_sendrawtx(topo->bitcoind, otx->hextx, broadcast_done, otx);
}
static enum watch_result closeinfo_txid_confirmed(struct lightningd *ld,
struct channel *channel,
const struct bitcoin_txid *txid,
unsigned int depth)
{
/* We delete ourselves first time, so should not be reorged out!! */
assert(depth > 0);
/* Subtle: depth 1 == current block. */
wallet_confirm_tx(ld->wallet, txid,
get_block_height(ld->topology) + 1 - depth);
return DELETE_WATCH;
}
/* We need to know if close_info UTXOs (which the wallet doesn't natively know
* how to spend, so is not in the normal path) get reconfirmed.
*
* This can happen on startup (where we manually unwind 100 blocks) or on a
* reorg. The db NULLs out the confirmation_height, so we can't easily figure
* out just the new ones (and removing the ON DELETE SET NULL clause is
* non-trivial).
*
* So every time, we just set a notification for every tx in this class we're
* not already watching: there are not usually many, nor many reorgs, so the
* redundancy is OK.
*/
static void watch_for_utxo_reconfirmation(struct chain_topology *topo,
struct wallet *wallet)
{
struct utxo **unconfirmed;
unconfirmed = wallet_get_unconfirmed_closeinfo_utxos(tmpctx, wallet);
for (size_t i = 0; i < tal_count(unconfirmed); i++) {
assert(unconfirmed[i]->close_info != NULL);
assert(unconfirmed[i]->blockheight == NULL);
if (find_txwatch(topo, &unconfirmed[i]->txid, NULL))
continue;
notleak(watch_txid(topo, topo, NULL, &unconfirmed[i]->txid,
closeinfo_txid_confirmed));
}
}
static const char *feerate_name(enum feerate feerate)
{
return feerate == FEERATE_IMMEDIATE ? "Immediate"
: feerate == FEERATE_NORMAL ? "Normal" : "Slow";
}
/* Mutual recursion via timer. */
static void next_updatefee_timer(struct chain_topology *topo);
/* We sanitize feerates if necessary to put them in descending order. */
static void update_feerates(struct bitcoind *bitcoind,
const u32 *satoshi_per_kw,
struct chain_topology *topo)
{
u32 old_feerates[NUM_FEERATES];
bool changed = false;
/* Smoothing factor alpha for simple exponential smoothing. The goal is to
* have the feerate account for 90 percent of the values polled in the last
* 2 minutes. The following will do that in a polling interval
* independent manner. */
double alpha = 1 - pow(0.1,(double)topo->poll_seconds / 120);
for (size_t i = 0; i < NUM_FEERATES; i++) {
u32 feerate = satoshi_per_kw[i];
/* Takes into account override_fee_rate */
old_feerates[i] = try_get_feerate(topo, i);
/* If estimatefee failed, don't do anything. */
if (!feerate)
continue;
/* Initial smoothed feerate is the polled feerate */
if (!old_feerates[i]) {
old_feerates[i] = feerate;
log_debug(topo->log,
"Smoothed feerate estimate for %s initialized to polled estimate %u",
feerate_name(i), feerate);
}
/* Smooth the feerate to avoid spikes. */
u32 feerate_smooth = feerate * alpha + old_feerates[i] * (1 - alpha);
/* But to avoid updating forever, only apply smoothing when its
* effect is more then 10 percent */
if (abs((int)feerate - (int)feerate_smooth) > (0.1 * feerate)) {
feerate = feerate_smooth;
log_debug(topo->log,
"... polled feerate estimate for %s (%u) smoothed to %u (alpha=%.2f)",
feerate_name(i), satoshi_per_kw[i],
feerate, alpha);
}
if (feerate < feerate_floor()) {
feerate = feerate_floor();
log_debug(topo->log,
"... feerate estimate for %s hit floor %u",
feerate_name(i), feerate);
}
if (feerate != topo->feerate[i]) {
log_debug(topo->log, "Feerate estimate for %s set to %u (was %u)",
feerate_name(i),
feerate, topo->feerate[i]);
}
topo->feerate[i] = feerate;
}
if (topo->feerate_uninitialized) {
/* This doesn't mean we *have* a fee estimate, but it does
* mean we tried. */
topo->feerate_uninitialized = false;
maybe_completed_init(topo);
}
/* Make sure fee rates are in order. */
for (size_t i = 0; i < NUM_FEERATES; i++) {
for (size_t j = 0; j < i; j++) {
if (topo->feerate[j] < topo->feerate[i]) {
log_debug(topo->log,
"Feerate estimate for %s (%u) above %s (%u)",
feerate_name(i), topo->feerate[i],
feerate_name(j), topo->feerate[j]);
topo->feerate[j] = topo->feerate[i];
}
}
if (try_get_feerate(topo, i) != old_feerates[i])
changed = true;
}
if (changed)
notify_feerate_change(bitcoind->ld);
next_updatefee_timer(topo);
}
static void start_fee_estimate(struct chain_topology *topo)
{
/* FEERATE_IMMEDIATE, FEERATE_NORMAL, FEERATE_SLOW */
const char *estmodes[] = { "CONSERVATIVE", "ECONOMICAL", "ECONOMICAL" };
const u32 blocks[] = { 2, 4, 100 };
BUILD_ASSERT(ARRAY_SIZE(blocks) == NUM_FEERATES);
/* Once per new block head, update fee estimates. */
bitcoind_estimate_fees(topo->bitcoind, blocks, estmodes, NUM_FEERATES,
update_feerates, topo);
}
static void next_updatefee_timer(struct chain_topology *topo)
{
/* This takes care of its own lifetime. */
notleak(new_reltimer(topo->timers, topo,
time_from_sec(topo->poll_seconds),
start_fee_estimate, topo));
}
/* Once we're run out of new blocks to add, call this. */
static void updates_complete(struct chain_topology *topo)
{
if (topo->tip != topo->prev_tip) {
/* Tell lightningd about new block. */
notify_new_block(topo->bitcoind->ld, topo->tip->height);
/* Tell watch code to re-evaluate all txs. */
watch_topology_changed(topo);
/* Maybe need to rebroadcast. */
rebroadcast_txs(topo, NULL);
/* We've processed these UTXOs */
db_set_intvar(topo->bitcoind->ld->wallet->db,
"last_processed_block", topo->tip->height);
topo->prev_tip = topo->tip;
}
/* Try again soon. */
next_topology_timer(topo);
}
/**
* topo_update_spends -- Tell the wallet about all spent outpoints
*/
static void topo_update_spends(struct chain_topology *topo, struct block *b)
{
const struct short_channel_id *scid;
for (size_t i = 0; i < tal_count(b->full_txs); i++) {
const struct bitcoin_tx *tx = b->full_txs[i];
for (size_t j = 0; j < tal_count(tx->input); j++) {
const struct bitcoin_tx_input *input = &tx->input[j];
scid = wallet_outpoint_spend(topo->wallet, tmpctx,
b->height, &input->txid,
input->index);
if (scid) {
gossipd_notify_spend(topo->bitcoind->ld, scid);
tal_free(scid);
}
}
}
}
static void topo_add_utxos(struct chain_topology *topo, struct block *b)
{
for (size_t i = 0; i < tal_count(b->full_txs); i++) {
const struct bitcoin_tx *tx = b->full_txs[i];
for (size_t j = 0; j < tal_count(tx->output); j++) {
const struct bitcoin_tx_output *output = &tx->output[j];
if (is_p2wsh(output->script, NULL)) {
wallet_utxoset_add(topo->wallet, tx, j,
b->height, i, output->script,
output->amount);
}
}
}
}
static void add_tip(struct chain_topology *topo, struct block *b)
{
/* Attach to tip; b is now the tip. */
assert(b->height == topo->tip->height + 1);
b->prev = topo->tip;
topo->tip->next = b;
topo->tip = b;
wallet_block_add(topo->wallet, b);
topo_add_utxos(topo, b);
topo_update_spends(topo, b);
/* Only keep the transactions we care about. */
filter_block_txs(topo, b);
block_map_add(&topo->block_map, b);
topo->max_blockheight = b->height;
}
static struct block *new_block(struct chain_topology *topo,
struct bitcoin_block *blk,
unsigned int height)
{
struct block *b = tal(topo, struct block);
sha256_double(&b->blkid.shad, &blk->hdr, sizeof(blk->hdr));
log_debug(topo->log, "Adding block %u: %s",
height,
type_to_string(tmpctx, struct bitcoin_blkid, &b->blkid));
assert(!block_map_get(&topo->block_map, &b->blkid));
b->next = NULL;
b->prev = NULL;
b->height = height;
b->hdr = blk->hdr;
b->txnums = tal_arr(b, u32, 0);
b->full_txs = tal_steal(b, blk->tx);
return b;
}
static void remove_tip(struct chain_topology *topo)
{
struct block *b = topo->tip;
struct bitcoin_txid *txs;
size_t i, n;
/* Move tip back one. */
topo->tip = b->prev;
if (!topo->tip)
fatal("Initial block %u (%s) reorganized out!",
b->height,
type_to_string(tmpctx, struct bitcoin_blkid, &b->blkid));
txs = wallet_transactions_by_height(b, topo->wallet, b->height);
n = tal_count(txs);
/* Notify that txs are kicked out. */
for (i = 0; i < n; i++)
txwatch_fire(topo, &txs[i], 0);
wallet_block_remove(topo->wallet, b);
/* This may have unconfirmed txs: reconfirm as we add blocks. */
watch_for_utxo_reconfirmation(topo, topo->wallet);
block_map_del(&topo->block_map, b);
tal_free(b);
}
static void have_new_block(struct bitcoind *bitcoind UNUSED,
struct bitcoin_block *blk,
struct chain_topology *topo)
{
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/* Unexpected predecessor? Free predecessor, refetch it. */
if (!bitcoin_blkid_eq(&topo->tip->blkid, &blk->hdr.prev_hash))
remove_tip(topo);
else
add_tip(topo, new_block(topo, blk, topo->tip->height + 1));
/* Try for next one. */
try_extend_tip(topo);
}
static void get_new_block(struct bitcoind *bitcoind,
const struct bitcoin_blkid *blkid,
struct chain_topology *topo)
{
if (!blkid) {
/* No such block, we're done. */
updates_complete(topo);
return;
}
bitcoind_getrawblock(bitcoind, blkid, have_new_block, topo);
}
static void try_extend_tip(struct chain_topology *topo)
{
bitcoind_getblockhash(topo->bitcoind, topo->tip->height + 1,
get_new_block, topo);
}
static void init_topo(struct bitcoind *bitcoind UNUSED,
struct bitcoin_block *blk,
struct chain_topology *topo)
{
topo->root = new_block(topo, blk, topo->max_blockheight);
block_map_add(&topo->block_map, topo->root);
topo->tip = topo->prev_tip = topo->root;
/* In case we don't get all the way to updates_complete */
db_set_intvar(topo->bitcoind->ld->wallet->db,
"last_processed_block", topo->tip->height);
maybe_completed_init(topo);
}
static void get_init_block(struct bitcoind *bitcoind,
const struct bitcoin_blkid *blkid,
struct chain_topology *topo)
{
bitcoind_getrawblock(bitcoind, blkid, init_topo, topo);
}
static void get_init_blockhash(struct bitcoind *bitcoind, u32 blockcount,
struct chain_topology *topo)
{
/* If bitcoind's current blockheight is below the requested height, just
* go back to that height. This might be a new node catching up, or
* bitcoind is processing a reorg. */
if (blockcount < topo->max_blockheight) {
if (topo->max_blockheight == UINT32_MAX) {
/* Relative rescan, but we didn't know the blockheight */
/* Protect against underflow in subtraction.
* Possible in regtest mode. */
if (blockcount < bitcoind->ld->config.rescan)
topo->max_blockheight = 0;
else
topo->max_blockheight = blockcount - bitcoind->ld->config.rescan;
} else {
/* Absolute blockheight, but bitcoind's blockheight isn't there yet */
/* Protect against underflow in subtraction.
* Possible in regtest mode. */
if (blockcount < 1)
topo->max_blockheight = 0;
else
topo->max_blockheight = blockcount - 1;
}
}
/* Rollback to the given blockheight, so we start track
* correctly again */
wallet_blocks_rollback(topo->wallet, topo->max_blockheight);
/* This may have unconfirmed txs: reconfirm as we add blocks. */
watch_for_utxo_reconfirmation(topo, topo->wallet);
/* Get up to speed with topology. */
bitcoind_getblockhash(bitcoind, topo->max_blockheight,
get_init_block, topo);
}
u32 get_block_height(const struct chain_topology *topo)
{
return topo->tip->height;
}
u32 try_get_feerate(const struct chain_topology *topo, enum feerate feerate)
{
return topo->feerate[feerate];
}
/* On shutdown, channels get deleted last. That frees from our list, so
* do it now instead. */
static void destroy_chain_topology(struct chain_topology *topo)
{
struct outgoing_tx *otx;
while ((otx = list_pop(&topo->outgoing_txs, struct outgoing_tx, list)))
tal_free(otx);
}
struct chain_topology *new_topology(struct lightningd *ld, struct log *log)
{
struct chain_topology *topo = tal(ld, struct chain_topology);
block_map_init(&topo->block_map);
list_head_init(&topo->outgoing_txs);
txwatch_hash_init(&topo->txwatches);
txowatch_hash_init(&topo->txowatches);
topo->log = log;
memset(topo->feerate, 0, sizeof(topo->feerate));
topo->bitcoind = new_bitcoind(topo, ld, log);
topo->wallet = ld->wallet;
topo->poll_seconds = 30;
topo->feerate_uninitialized = true;
topo->root = NULL;
return topo;
}
void setup_topology(struct chain_topology *topo,
struct timers *timers,
u32 min_blockheight, u32 max_blockheight)
{
memset(&topo->feerate, 0, sizeof(topo->feerate));
topo->timers = timers;
topo->min_blockheight = min_blockheight;
topo->max_blockheight = max_blockheight;
/* Make sure bitcoind is started, and ready */
wait_for_bitcoind(topo->bitcoind);
bitcoind_getblockcount(topo->bitcoind, get_init_blockhash, topo);
tal_add_destructor(topo, destroy_chain_topology);
start_fee_estimate(topo);
/* Once it gets initial block, it calls io_break() and we return. */
io_loop(NULL, NULL);
}
void begin_topology(struct chain_topology *topo)
{
try_extend_tip(topo);
}