core-lightning/daemon/chaintopology.c
Christian Decker f4568e5c1c routing: Added IRC announcement glue
Added channel announcement serialization and parsing, as well as the
entrypoints for the IRC peer discovery. Announcements are signed by the
sending endpoint and signatures are verified before adding the channels
to the local view of the topology. We do not yet verify the existence of
the anchor transaction.
2016-09-07 23:49:39 +02:00

530 lines
12 KiB
C

#include "bitcoin/block.h"
#include "bitcoin/tx.h"
#include "bitcoind.h"
#include "chaintopology.h"
#include "lightningd.h"
#include "log.h"
#include "peer.h"
#include "timeout.h"
#include "utils.h"
#include "watch.h"
#include <ccan/array_size/array_size.h>
#include <ccan/asort/asort.h>
#include <ccan/io/io.h>
#include <ccan/structeq/structeq.h>
#include <inttypes.h>
struct block {
int height;
/* Actual header. */
struct bitcoin_block_hdr hdr;
/* Previous block (if any). */
struct block *prev;
/* Next block (if any). */
struct block *next;
/* Key for hash table */
struct sha256_double blkid;
/* 0 if not enough predecessors. */
u32 mediantime;
/* Transactions in this block we care about */
struct sha256_double *txids;
/* Full copy of txs (trimmed to txs list in connect_block) */
struct bitcoin_tx **full_txs;
};
/* Hash blocks by sha */
static const struct sha256_double *keyof_block_map(const struct block *b)
{
return &b->blkid;
}
static size_t hash_sha(const struct sha256_double *key)
{
size_t ret;
memcpy(&ret, key, sizeof(ret));
return ret;
}
static bool block_eq(const struct block *b, const struct sha256_double *key)
{
return structeq(&b->blkid, key);
}
HTABLE_DEFINE_TYPE(struct block, keyof_block_map, hash_sha, block_eq, block_map);
struct topology {
struct block *root;
struct block *tip;
struct block_map block_map;
u64 feerate;
bool startup;
};
static void start_poll_chaintip(struct lightningd_state *dstate);
static void next_topology_timer(struct lightningd_state *dstate)
{
if (dstate->topology->startup) {
dstate->topology->startup = false;
io_break(dstate);
}
new_reltimer(dstate, dstate, dstate->config.poll_time,
start_poll_chaintip, dstate);
}
static int cmp_times(const u32 *a, const u32 *b, void *unused)
{
if (*a > *b)
return -1;
else if (*b > * a)
return 1;
return 0;
}
/* Mediantime is median of this and previous 10 blocks. */
static u32 get_mediantime(const struct topology *topo, const struct block *b)
{
unsigned int i;
u32 times[11];
for (i = 0; i < ARRAY_SIZE(times); i++) {
if (!b)
return 0;
times[i] = le32_to_cpu(b->hdr.timestamp);
b = b->prev;
}
asort(times, ARRAY_SIZE(times), cmp_times, NULL);
return times[ARRAY_SIZE(times) / 2];
}
/* FIXME: Remove tx from block when peer done. */
static void add_tx_to_block(struct block *b, const struct sha256_double *txid)
{
size_t n = tal_count(b->txids);
tal_resize(&b->txids, n+1);
b->txids[n] = *txid;
}
static bool we_broadcast(struct lightningd_state *dstate,
const struct sha256_double *txid)
{
struct peer *peer;
list_for_each(&dstate->peers, peer, list) {
struct outgoing_tx *otx;
list_for_each(&peer->outgoing_txs, otx, list) {
if (structeq(&otx->txid, txid))
return true;
}
}
return false;
}
/* Fills in prev, height, mediantime. */
static void connect_block(struct lightningd_state *dstate,
struct block *prev,
struct block *b)
{
struct topology *topo = dstate->topology;
size_t i;
assert(b->height == -1);
assert(b->mediantime == 0);
assert(b->prev == NULL);
assert(prev->next == b);
b->prev = prev;
b->height = b->prev->height + 1;
b->mediantime = get_mediantime(topo, b);
block_map_add(&topo->block_map, b);
/* Now we see if any of those txs are interesting. */
for (i = 0; i < tal_count(b->full_txs); i++) {
struct bitcoin_tx *tx = b->full_txs[i];
struct sha256_double txid;
size_t j;
/* Tell them if it spends a txo we care about. */
for (j = 0; j < tx->input_count; j++) {
struct txwatch_output out;
struct txowatch *txo;
out.txid = tx->input[j].txid;
out.index = tx->input[j].index;
txo = txowatch_hash_get(&dstate->txowatches, &out);
if (txo)
txowatch_fire(dstate, txo, tx, j);
}
/* We did spends first, in case that tells us to watch tx. */
bitcoin_txid(tx, &txid);
if (watching_txid(dstate, &txid) || we_broadcast(dstate, &txid))
add_tx_to_block(b, &txid);
}
b->full_txs = tal_free(b->full_txs);
}
static bool tx_in_block(const struct block *b,
const struct sha256_double *txid)
{
size_t i, n = tal_count(b->txids);
for (i = 0; i < n; i++) {
if (structeq(&b->txids[i], txid))
return true;
}
return false;
}
/* FIXME: Use hash table. */
static struct block *block_for_tx(struct lightningd_state *dstate,
const struct sha256_double *txid)
{
struct topology *topo = dstate->topology;
struct block *b;
for (b = topo->tip; b; b = b->prev) {
if (tx_in_block(b, txid))
return b;
}
return NULL;
}
size_t get_tx_depth(struct lightningd_state *dstate,
const struct sha256_double *txid)
{
struct topology *topo = dstate->topology;
const struct block *b;
b = block_for_tx(dstate, txid);
if (!b)
return 0;
return topo->tip->height - b->height + 1;
}
static void try_broadcast(struct lightningd_state *dstate,
const char *msg, char **txs)
{
size_t num_txs = tal_count(txs);
const char *this_tx;
/* These are expected. */
if (strstr(msg, "txn-mempool-conflict")
|| strstr(msg, "transaction already in block chain"))
log_debug(dstate->base_log,
"Expected error broadcasting tx %s: %s",
txs[num_txs-1], msg);
else
log_unusual(dstate->base_log, "Broadcasting tx %s: %s",
txs[num_txs-1], msg);
if (num_txs == 1) {
tal_free(txs);
return;
}
/* Strip off last one. */
this_tx = txs[num_txs-1];
tal_resize(&txs, num_txs-1);
bitcoind_sendrawtx(dstate, this_tx, try_broadcast, 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 lightningd_state *dstate)
{
/* Copy txs now (peers may go away, and they own txs). */
size_t num_txs = 0;
char **txs = tal_arr(dstate, char *, 0);
struct peer *peer;
list_for_each(&dstate->peers, peer, list) {
struct outgoing_tx *otx;
list_for_each(&peer->outgoing_txs, otx, list) {
u8 *rawtx;
if (block_for_tx(dstate, &otx->txid))
continue;
tal_resize(&txs, num_txs+1);
rawtx = linearize_tx(txs, otx->tx);
txs[num_txs] = tal_hexstr(txs, rawtx, tal_count(rawtx));
num_txs++;
}
}
if (num_txs)
bitcoind_sendrawtx(dstate, txs[num_txs-1], try_broadcast, txs);
else
tal_free(txs);
}
static void destroy_outgoing_tx(struct outgoing_tx *otx)
{
list_del(&otx->list);
}
void broadcast_tx(struct peer *peer, const struct bitcoin_tx *tx)
{
struct outgoing_tx *otx = tal(peer, struct outgoing_tx);
char **txs = tal_arr(peer->dstate, char *, 1);
u8 *rawtx;
otx->tx = tal_steal(otx, tx);
bitcoin_txid(otx->tx, &otx->txid);
list_add_tail(&peer->outgoing_txs, &otx->list);
tal_add_destructor(otx, destroy_outgoing_tx);
log_add_struct(peer->log, " (tx %s)", struct sha256_double, &otx->txid);
rawtx = linearize_tx(txs, otx->tx);
txs[0] = tal_hexstr(txs, rawtx, tal_count(rawtx));
bitcoind_sendrawtx(peer->dstate, txs[0], try_broadcast, txs);
}
static void free_blocks(struct lightningd_state *dstate, struct block *b)
{
struct block *next;
while (b) {
size_t i, n = tal_count(b->txids);
/* Notify that txs are kicked out. */
for (i = 0; i < n; i++)
txwatch_fire(dstate, &b->txids[i], 0);
next = b->next;
tal_free(b);
b = next;
}
}
static void update_fee(struct lightningd_state *dstate, u64 rate, u64 *feerate)
{
log_debug(dstate->base_log, "Feerate %"PRIu64" -> %"PRIu64,
rate, *feerate);
*feerate = rate;
}
/* B is the new chain (linked by ->next); update topology */
static void topology_changed(struct lightningd_state *dstate,
struct block *prev,
struct block *b)
{
/* Eliminate any old chain. */
if (prev->next)
free_blocks(dstate, prev->next);
prev->next = b;
do {
connect_block(dstate, prev, b);
dstate->topology->tip = prev = b;
b = b->next;
} while (b);
/* Tell watch code to re-evaluate all txs. */
watch_topology_changed(dstate);
/* Maybe need to rebroadcast. */
rebroadcast_txs(dstate);
/* Once per new block head, update fee estimate. */
bitcoind_estimate_fee(dstate, update_fee, &dstate->topology->feerate);
}
static struct block *new_block(struct lightningd_state *dstate,
struct bitcoin_block *blk,
struct block *next)
{
struct topology *topo = dstate->topology;
struct block *b = tal(topo, struct block);
sha256_double(&b->blkid, &blk->hdr, sizeof(blk->hdr));
log_debug_struct(dstate->base_log, "Adding block %s",
struct sha256_double, &b->blkid);
assert(!block_map_get(&topo->block_map, &b->blkid));
b->next = next;
/* We fill these out in topology_changed */
b->height = -1;
b->mediantime = 0;
b->prev = NULL;
b->hdr = blk->hdr;
b->txids = tal_arr(b, struct sha256_double, 0);
b->full_txs = tal_steal(b, blk->tx);
return b;
}
static void gather_blocks(struct lightningd_state *dstate,
struct bitcoin_block *blk,
struct block *next)
{
struct topology *topo = dstate->topology;
struct block *b, *prev;
b = new_block(dstate, blk, next);
/* Recurse if we need prev. */
prev = block_map_get(&topo->block_map, &blk->hdr.prev_hash);
if (!prev) {
bitcoind_getrawblock(dstate, &blk->hdr.prev_hash,
gather_blocks, b);
return;
}
/* All done. */
topology_changed(dstate, prev, b);
next_topology_timer(dstate);
}
static void check_chaintip(struct lightningd_state *dstate,
const struct sha256_double *tipid,
void *arg)
{
struct topology *topo = dstate->topology;
/* 0 is the main tip. */
if (!structeq(tipid, &topo->tip->blkid))
bitcoind_getrawblock(dstate, tipid, gather_blocks,
(struct block *)NULL);
else
/* Next! */
next_topology_timer(dstate);
}
static void start_poll_chaintip(struct lightningd_state *dstate)
{
if (!list_empty(&dstate->bitcoin_req)) {
log_unusual(dstate->base_log,
"Delaying start poll: commands in progress");
next_topology_timer(dstate);
} else
bitcoind_get_chaintip(dstate, check_chaintip, NULL);
}
static void init_topo(struct lightningd_state *dstate,
struct bitcoin_block *blk,
ptrint_t *p)
{
struct topology *topo = dstate->topology;
topo->root = new_block(dstate, blk, NULL);
topo->root->height = ptr2int(p);
block_map_add(&topo->block_map, topo->root);
topo->tip = topo->root;
/* Now grab chaintip immediately. */
bitcoind_get_chaintip(dstate, check_chaintip, NULL);
}
static void get_init_block(struct lightningd_state *dstate,
const struct sha256_double *blkid,
ptrint_t *blknum)
{
bitcoind_getrawblock(dstate, blkid, init_topo, blknum);
}
static void get_init_blockhash(struct lightningd_state *dstate, u32 blockcount,
void *unused)
{
u32 start;
struct peer *peer;
if (blockcount < 100)
start = 0;
else
start = blockcount - 100;
/* If loaded from database, go back to earliest possible peer anchor. */
list_for_each(&dstate->peers, peer, list) {
if (peer->anchor.min_depth && peer->anchor.min_depth < start)
start = peer->anchor.min_depth;
}
/* Start topology from 100 blocks back. */
bitcoind_getblockhash(dstate, start, get_init_block, int2ptr(start));
}
u32 get_tx_mediantime(struct lightningd_state *dstate,
const struct sha256_double *txid)
{
struct block *b;
b = block_for_tx(dstate, txid);
if (b)
return b->mediantime;
fatal("Tx %s not found for get_tx_mediantime",
tal_hexstr(dstate, txid, sizeof(*txid)));
}
u32 get_tip_mediantime(struct lightningd_state *dstate)
{
return dstate->topology->tip->mediantime;
}
u32 get_block_height(struct lightningd_state *dstate)
{
return dstate->topology->tip->height;
}
u64 get_feerate(struct lightningd_state *dstate)
{
if (dstate->topology->feerate == 0) {
log_info(dstate->base_log,
"No fee estimate: using default fee rate");
return dstate->config.default_fee_rate;
}
return dstate->topology->feerate;
}
struct txlocator *locate_tx(const void *ctx, struct lightningd_state *dstate,
const struct sha256_double *txid)
{
struct block *block = block_for_tx(dstate, txid);
if (block == NULL) {
return NULL;
}
struct txlocator *loc = talz(ctx, struct txlocator);
loc->blkheight = block->height;
size_t i, n = tal_count(block->txids);
for (i = 0; i < n; i++) {
if (structeq(&block->txids[i], txid)){
loc->index = i;
break;
}
}
return loc;
}
void setup_topology(struct lightningd_state *dstate)
{
dstate->topology = tal(dstate, struct topology);
block_map_init(&dstate->topology->block_map);
dstate->topology->startup = true;
dstate->topology->feerate = 0;
bitcoind_getblockcount(dstate, get_init_blockhash, NULL);
/* Once it gets topology, it calls io_break() and we return. */
io_loop(NULL, NULL);
assert(!dstate->topology->startup);
}