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#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/structeq/structeq.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;
};
static void start_poll_chaintips(struct lightningd_state *dstate);
static void next_topology_timer(struct lightningd_state *dstate)
{
new_reltimer(dstate, dstate, dstate->config.poll_time,
start_poll_chaintips, 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;
}
}
/* 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);
}
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_chaintips(struct lightningd_state *dstate,
struct sha256_double *blockids,
void *arg)
{
struct topology *topo = dstate->topology;
/* 0 is the main tip. */
if (!topo->tip || !structeq(&blockids[0], &topo->tip->blkid))
bitcoind_getrawblock(dstate, &blockids[0], gather_blocks,
(struct block *)NULL);
else
/* Next! */
next_topology_timer(dstate);
}
static void start_poll_chaintips(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_chaintips(dstate, check_chaintips, 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);
/* Now grab chaintips immediately. */
bitcoind_get_chaintips(dstate, check_chaintips, 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;
if (blockcount < 100)
start = 0;
else
start = blockcount - 100;
/* 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;
}
void setup_topology(struct lightningd_state *dstate)
{
dstate->topology = tal(dstate, struct topology);
dstate->topology->tip = NULL;
block_map_init(&dstate->topology->block_map);
bitcoind_getblockcount(dstate, get_init_blockhash, NULL);
}