core-lightning/wallet/wallet.c

#include "wallet.h"

#include <bitcoin/script.h>
#include <ccan/tal/str/str.h>
#include <inttypes.h>
#include <lightningd/lightningd.h>
#include <lightningd/log.h>
#include <lightningd/peer_control.h>
#include <lightningd/peer_htlcs.h>

#define SQLITE_MAX_UINT 0x7FFFFFFFFFFFFFFF
#define DIRECTION_INCOMING 0
#define DIRECTION_OUTGOING 1

struct wallet *wallet_new(const tal_t *ctx, struct log *log)
{
	struct wallet *wallet = tal(ctx, struct wallet);
	wallet->db = db_setup(wallet);
	wallet->log = log;
	wallet->bip32_base = NULL;
	return wallet;
}

/* We actually use the db constraints to uniquify, so OK if this fails. */
bool wallet_add_utxo(struct wallet *w, struct utxo *utxo,
		     enum wallet_output_type type)
{
	sqlite3_stmt *stmt;

	stmt = db_prepare(w->db, "INSERT INTO outputs (prev_out_tx, prev_out_index, value, type, status, keyindex) VALUES (?, ?, ?, ?, ?, ?);");
	sqlite3_bind_blob(stmt, 1, &utxo->txid, sizeof(utxo->txid), SQLITE_TRANSIENT);
	sqlite3_bind_int(stmt, 2, utxo->outnum);
	sqlite3_bind_int64(stmt, 3, utxo->amount);
	sqlite3_bind_int(stmt, 4, type);
	sqlite3_bind_int(stmt, 5, output_state_available);
	sqlite3_bind_int(stmt, 6, utxo->keyindex);
	return db_exec_prepared_mayfail(w->db, stmt);
}

/**
 * wallet_stmt2output - Extract data from stmt and fill a utxo
 *
 * Returns true on success.
 */
static bool wallet_stmt2output(sqlite3_stmt *stmt, struct utxo *utxo)
{
	memcpy(&utxo->txid, sqlite3_column_blob(stmt, 0), sqlite3_column_bytes(stmt, 0));
	utxo->outnum = sqlite3_column_int(stmt, 1);
	utxo->amount = sqlite3_column_int(stmt, 2);
	utxo->is_p2sh = sqlite3_column_int(stmt, 3) == p2sh_wpkh;
	utxo->status = sqlite3_column_int(stmt, 4);
	utxo->keyindex = sqlite3_column_int(stmt, 5);
	return true;
}

bool wallet_update_output_status(struct wallet *w,
				 const struct sha256_double *txid,
				 const u32 outnum, enum output_status oldstatus,
				 enum output_status newstatus)
{
	sqlite3_stmt *stmt;
	if (oldstatus != output_state_any) {
		stmt = db_prepare(
			w->db, "UPDATE outputs SET status=? WHERE status=? AND prev_out_tx=? AND prev_out_index=?");
		sqlite3_bind_int(stmt, 1, newstatus);
		sqlite3_bind_int(stmt, 2, oldstatus);
		sqlite3_bind_blob(stmt, 3, txid, sizeof(*txid), SQLITE_TRANSIENT);
		sqlite3_bind_int(stmt, 4, outnum);
	} else {
		stmt = db_prepare(
			w->db, "UPDATE outputs SET status=? WHERE prev_out_tx=? AND prev_out_index=?");
		sqlite3_bind_int(stmt, 1, newstatus);
		sqlite3_bind_blob(stmt, 2, txid, sizeof(*txid), SQLITE_TRANSIENT);
		sqlite3_bind_int(stmt, 3, outnum);
	}
	db_exec_prepared(w->db, stmt);
	return sqlite3_changes(w->db->sql) > 0;
}

struct utxo **wallet_get_utxos(const tal_t *ctx, struct wallet *w, const enum output_status state)
{
	struct utxo **results;
	int i;

	sqlite3_stmt *stmt = db_prepare(
		w->db, "SELECT prev_out_tx, prev_out_index, value, type, status, keyindex "
		"FROM outputs WHERE status=?1 OR ?1=255");
	sqlite3_bind_int(stmt, 1, state);

       	results = tal_arr(ctx, struct utxo*, 0);
	for (i=0; sqlite3_step(stmt) == SQLITE_ROW; i++) {
		tal_resize(&results, i+1);
		results[i] = tal(results, struct utxo);
		wallet_stmt2output(stmt, results[i]);
	}
	sqlite3_finalize(stmt);

	return results;
}

/**
 * unreserve_utxo - Mark a reserved UTXO as available again
 */
static void unreserve_utxo(struct wallet *w, const struct utxo *unres)
{
	if (!wallet_update_output_status(w, &unres->txid, unres->outnum,
					 output_state_reserved,
					 output_state_available)) {
		fatal("Unable to unreserve output: %s", w->db->err);
	}
}

/**
 * destroy_utxos - Destructor for an array of pointers to utxo
 */
static void destroy_utxos(const struct utxo **utxos, struct wallet *w)
{
	for (size_t i = 0; i < tal_count(utxos); i++)
		unreserve_utxo(w, utxos[i]);
}

void wallet_confirm_utxos(struct wallet *w, const struct utxo **utxos)
{
	tal_del_destructor2(utxos, destroy_utxos, w);
	for (size_t i = 0; i < tal_count(utxos); i++) {
		if (!wallet_update_output_status(
			w, &utxos[i]->txid, utxos[i]->outnum,
			output_state_reserved, output_state_spent)) {
			fatal("Unable to mark output as spent: %s", w->db->err);
		}
	}
}

const struct utxo **wallet_select_coins(const tal_t *ctx, struct wallet *w,
					const u64 value,
					const u32 feerate_per_kw,
					u64 *fee_estimate, u64 *changesatoshi)
{
	size_t i = 0;
	bool should_commit;
	struct utxo **available;
	const struct utxo **utxos = tal_arr(ctx, const struct utxo *, 0);
	*fee_estimate = 0;

	/* We assume two outputs for the weight. */
	u64 satoshi_in = 0, weight = (4 + (8 + 22) * 2 + 4) * 4;
	tal_add_destructor2(utxos, destroy_utxos, w);

	should_commit = db_begin_transaction(w->db);

	available = wallet_get_utxos(ctx, w, output_state_available);

	for (i = 0; i < tal_count(available); i++) {
		tal_resize(&utxos, i + 1);
		utxos[i] = tal_steal(utxos, available[i]);

		if (!wallet_update_output_status(
			w, &available[i]->txid, available[i]->outnum,
			output_state_available, output_state_reserved))
			fatal("Unable to reserve output: %s", w->db->err);

		weight += (32 + 4 + 4) * 4;
		if (utxos[i]->is_p2sh)
			weight += 22 * 4;

		/* Account for witness (1 byte count + sig + key */
		weight += 1 + (1 + 73 + 1 + 33);
		*fee_estimate = weight * feerate_per_kw / 1000;
		satoshi_in += utxos[i]->amount;
		if (satoshi_in >= *fee_estimate + value)
			break;
	}
	tal_free(available);

	if (satoshi_in < *fee_estimate + value) {
		/* Could not collect enough inputs, cleanup and bail */
		utxos = tal_free(utxos);
		if (should_commit)
			db_rollback_transaction(w->db);
	} else {
		/* Commit the db transaction to persist markings */
		if (should_commit)
			db_commit_transaction(w->db);
		*changesatoshi = satoshi_in - value - *fee_estimate;

	}
	return utxos;
}

bool wallet_can_spend(struct wallet *w, const u8 *script,
		      u32 *index, bool *output_is_p2sh)
{
	struct ext_key ext;
	u64 bip32_max_index = db_get_intvar(w->db, "bip32_max_index", 0);
	u32 i;

	/* If not one of these, can't be for us. */
	if (is_p2sh(script, NULL))
		*output_is_p2sh = true;
	else if (is_p2wpkh(script, NULL))
		*output_is_p2sh = false;
	else
		return false;

	for (i = 0; i <= bip32_max_index; i++) {
		u8 *s;

		if (bip32_key_from_parent(w->bip32_base, i,
					  BIP32_FLAG_KEY_PUBLIC, &ext)
		    != WALLY_OK) {
			abort();
		}
		s = scriptpubkey_p2wpkh_derkey(w, ext.pub_key);
		if (*output_is_p2sh) {
			u8 *p2sh = scriptpubkey_p2sh(w, s);
			tal_free(s);
			s = p2sh;
		}
		if (scripteq(s, script)) {
			tal_free(s);
			*index = i;
			return true;
		}
		tal_free(s);
	}
	return false;
}

s64 wallet_get_newindex(struct lightningd *ld)
{
	u64 newidx = db_get_intvar(ld->wallet->db, "bip32_max_index", 0) + 1;

	if (newidx == BIP32_INITIAL_HARDENED_CHILD)
		return -1;

	db_set_intvar(ld->wallet->db, "bip32_max_index", newidx);
	return newidx;
}

bool wallet_shachain_init(struct wallet *wallet, struct wallet_shachain *chain)
{
	sqlite3_stmt *stmt;
	/* Create shachain */
	shachain_init(&chain->chain);
	stmt = db_prepare(wallet->db, "INSERT INTO shachains (min_index, num_valid) VALUES (?, 0);");
	sqlite3_bind_int64(stmt, 1, chain->chain.min_index);
	if (!db_exec_prepared(wallet->db, stmt)) {
		return false;
	}

	chain->id = sqlite3_last_insert_rowid(wallet->db->sql);
	return true;
}

/* TODO(cdecker) Stolen from shachain, move to some appropriate location */
static unsigned int count_trailing_zeroes(uint64_t index)
{
#if HAVE_BUILTIN_CTZLL
	return index ? (unsigned int)__builtin_ctzll(index) : SHACHAIN_BITS;
#else
	unsigned int i;

	for (i = 0; i < SHACHAIN_BITS; i++) {
		if (index & (1ULL << i))
			break;
	}
	return i;
#endif
}

bool wallet_shachain_add_hash(struct wallet *wallet,
			      struct wallet_shachain *chain,
			      uint64_t index,
			      const struct sha256 *hash)
{
	sqlite3_stmt *stmt;
	bool should_commit;
	bool ok = true;
	u32 pos = count_trailing_zeroes(index);
	assert(index < SQLITE_MAX_UINT);
	if (!shachain_add_hash(&chain->chain, index, hash)) {
		return false;
	}

	should_commit = db_begin_transaction(wallet->db);

	stmt = db_prepare(wallet->db, "UPDATE shachains SET num_valid=?, min_index=? WHERE id=?");
	sqlite3_bind_int(stmt, 1, chain->chain.num_valid);
	sqlite3_bind_int64(stmt, 2, index);
	sqlite3_bind_int64(stmt, 3, chain->id);
	ok &= db_exec_prepared(wallet->db, stmt);

	stmt = db_prepare(
		wallet->db,
		"REPLACE INTO shachain_known (shachain_id, pos, idx, hash) VALUES (?, ?, ?, ?);");
	sqlite3_bind_int64(stmt, 1, chain->id);
	sqlite3_bind_int(stmt, 2, pos);
	sqlite3_bind_int64(stmt, 3, index);
	sqlite3_bind_blob(stmt, 4, hash, sizeof(*hash), SQLITE_TRANSIENT);
	ok &= db_exec_prepared(wallet->db, stmt);

	if (should_commit) {
		if (ok)
			ok &= db_commit_transaction(wallet->db);
		else
			db_rollback_transaction(wallet->db);
	}
	return ok;
}

bool wallet_shachain_load(struct wallet *wallet, u64 id,
			  struct wallet_shachain *chain)
{
	int err;
	sqlite3_stmt *stmt;
	chain->id = id;
	shachain_init(&chain->chain);

	/* Load shachain metadata */
	stmt = db_prepare(wallet->db, "SELECT min_index, num_valid FROM shachains WHERE id=?");
	sqlite3_bind_int64(stmt, 1, id);

	err = sqlite3_step(stmt);
	if (err != SQLITE_ROW) {
		sqlite3_finalize(stmt);
		return false;
	}

	chain->chain.min_index = sqlite3_column_int64(stmt, 0);
	chain->chain.num_valid = sqlite3_column_int64(stmt, 1);
	sqlite3_finalize(stmt);

	/* Load shachain known entries */
	stmt = db_prepare(wallet->db, "SELECT idx, hash, pos FROM shachain_known WHERE shachain_id=?");
	sqlite3_bind_int64(stmt, 1, id);

	while (sqlite3_step(stmt) == SQLITE_ROW) {
		int pos = sqlite3_column_int(stmt, 2);
		chain->chain.known[pos].index = sqlite3_column_int64(stmt, 0);
		memcpy(&chain->chain.known[pos].hash, sqlite3_column_blob(stmt, 1), sqlite3_column_bytes(stmt, 1));
	}

	sqlite3_finalize(stmt);
	return true;
}

static bool wallet_peer_load(struct wallet *w, const u64 id, struct peer *peer)
{
	bool ok = true;
	sqlite3_stmt *stmt = db_query(__func__, w->db, "SELECT id, node_id FROM peers WHERE id=%"PRIu64";", id);
	if (!stmt || sqlite3_step(stmt) != SQLITE_ROW) {
		sqlite3_finalize(stmt);
		return false;
	}
	peer->dbid = sqlite3_column_int64(stmt, 0);
	ok &= sqlite3_column_pubkey(stmt, 1, &peer->id);
	sqlite3_finalize(stmt);
	return ok;
}

bool wallet_peer_by_nodeid(struct wallet *w, const struct pubkey *nodeid,
			   struct peer *peer)
{
	bool ok;
	tal_t *tmpctx = tal_tmpctx(w);
	sqlite3_stmt *stmt = db_prepare(w->db, "SELECT id, node_id FROM peers WHERE node_id=?;");
	sqlite3_bind_pubkey(stmt, 1, nodeid);

	ok = stmt != NULL && sqlite3_step(stmt) == SQLITE_ROW;
	if (ok) {
		peer->dbid = sqlite3_column_int64(stmt, 0);
		ok &= sqlite3_column_pubkey(stmt, 1, &peer->id);
	} else {
		/* Make sure we mark this as a new peer */
		peer->dbid = 0;
	}
	sqlite3_finalize(stmt);
	tal_free(tmpctx);
	return ok;
}

/**
 * wallet_stmt2channel - Helper to populate a wallet_channel from a sqlite3_stmt
 *
 * Returns true on success.
 */
static bool wallet_stmt2channel(struct wallet *w, sqlite3_stmt *stmt,
				struct wallet_channel *chan)
{
	bool ok = true;
	int col = 0;
	struct channel_info *channel_info;
	u64 remote_config_id;

	if (!chan->peer) {
		chan->peer = talz(chan, struct peer);
	}
	chan->id = sqlite3_column_int64(stmt, col++);
	chan->peer->dbid = sqlite3_column_int64(stmt, col++);
	wallet_peer_load(w, chan->peer->dbid, chan->peer);

	if (sqlite3_column_type(stmt, col) != SQLITE_NULL) {
		chan->peer->scid = tal(chan->peer, struct short_channel_id);
		sqlite3_column_short_channel_id(stmt, col++, chan->peer->scid);
	} else {
		chan->peer->scid = NULL;
		col++;
	}

	chan->peer->our_config.id = sqlite3_column_int64(stmt, col++);
	wallet_channel_config_load(w, chan->peer->our_config.id, &chan->peer->our_config);
	remote_config_id = sqlite3_column_int64(stmt, col++);

	chan->peer->state = sqlite3_column_int(stmt, col++);
	chan->peer->funder = sqlite3_column_int(stmt, col++);
	chan->peer->channel_flags = sqlite3_column_int(stmt, col++);
	chan->peer->minimum_depth = sqlite3_column_int(stmt, col++);
	chan->peer->next_index[LOCAL] = sqlite3_column_int64(stmt, col++);
	chan->peer->next_index[REMOTE] = sqlite3_column_int64(stmt, col++);
	chan->peer->next_htlc_id = sqlite3_column_int64(stmt, col++);

	if (sqlite3_column_type(stmt, col) != SQLITE_NULL) {
		assert(sqlite3_column_bytes(stmt, col) == 32);
		chan->peer->funding_txid = tal(chan->peer, struct sha256_double);
		memcpy(chan->peer->funding_txid, sqlite3_column_blob(stmt, col), 32);
	} else {
		chan->peer->funding_txid = NULL;
	}
	col++;

	chan->peer->funding_outnum = sqlite3_column_int(stmt, col++);
	chan->peer->funding_satoshi = sqlite3_column_int64(stmt, col++);
	chan->peer->remote_funding_locked =
	    sqlite3_column_int(stmt, col++) != 0;
	chan->peer->push_msat = sqlite3_column_int64(stmt, col++);

	if (sqlite3_column_type(stmt, col) != SQLITE_NULL) {
		chan->peer->our_msatoshi = tal(chan->peer, u64);
		*chan->peer->our_msatoshi = sqlite3_column_int64(stmt, col);
	}else {
		chan->peer->our_msatoshi = tal_free(chan->peer->our_msatoshi);
	}
	col++;

	/* See if we have a valid commit_sig indicating the presence
	 * of channel_info */
	if (sqlite3_column_type(stmt, col) != SQLITE_NULL) {
		/* OK, so we have a valid sig, instantiate and/or fill
		 * in channel_info */
		if (!chan->peer->channel_info)
			chan->peer->channel_info = tal(chan->peer, struct channel_info);
		channel_info = chan->peer->channel_info;

		/* Populate channel_info */
		ok &= sqlite3_column_pubkey(stmt, col++, &chan->peer->channel_info->remote_fundingkey);
		ok &= sqlite3_column_pubkey(stmt, col++, &channel_info->theirbase.revocation);
		ok &= sqlite3_column_pubkey(stmt, col++, &channel_info->theirbase.payment);
		ok &= sqlite3_column_pubkey(stmt, col++, &channel_info->theirbase.delayed_payment);
		ok &= sqlite3_column_pubkey(stmt, col++, &channel_info->remote_per_commit);
		ok &= sqlite3_column_pubkey(stmt, col++, &channel_info->old_remote_per_commit);
		channel_info->feerate_per_kw = sqlite3_column_int64(stmt, col++);
		wallet_channel_config_load(w, remote_config_id, &chan->peer->channel_info->their_config);
	} else {
		/* No channel_info, skip positions in the result */
		col += 7;
	}

	/* Load shachain */
	u64 shachain_id = sqlite3_column_int64(stmt, col++);
	ok &= wallet_shachain_load(w, shachain_id, &chan->peer->their_shachain);

	/* Do we have a non-null remote_shutdown_scriptpubkey? */
	if (sqlite3_column_type(stmt, col) != SQLITE_NULL) {
		chan->peer->remote_shutdown_scriptpubkey = tal_arr(chan->peer, u8, sqlite3_column_bytes(stmt, col));
		memcpy(chan->peer->remote_shutdown_scriptpubkey, sqlite3_column_blob(stmt, col), sqlite3_column_bytes(stmt, col));
		chan->peer->local_shutdown_idx = sqlite3_column_int64(stmt, col++);
	} else {
		chan->peer->remote_shutdown_scriptpubkey = tal_free(chan->peer->remote_shutdown_scriptpubkey);
		chan->peer->local_shutdown_idx = -1;
		col += 2;
	}

	/* Do we have a last_sent_commit, if yes, populate */
	if (sqlite3_column_type(stmt, col) != SQLITE_NULL) {
		if (!chan->peer->last_sent_commit) {
			chan->peer->last_sent_commit = tal(chan->peer, struct changed_htlc);
		}
		chan->peer->last_sent_commit->newstate = sqlite3_column_int64(stmt, col++);
		chan->peer->last_sent_commit->id = sqlite3_column_int64(stmt, col++);
	} else {
		chan->peer->last_sent_commit = tal_free(chan->peer->last_sent_commit);
		col += 2;
	}

	/* Do we have last_tx?  If so, populate. */
	if (sqlite3_column_type(stmt, col) != SQLITE_NULL) {
		chan->peer->last_tx = sqlite3_column_tx(chan->peer, stmt, col++);
		chan->peer->last_sig = tal(chan->peer, secp256k1_ecdsa_signature);
		sqlite3_column_signature(stmt, col++, chan->peer->last_sig);
	} else {
		chan->peer->last_tx = tal_free(chan->peer->last_tx);
		chan->peer->last_sig = tal_free(chan->peer->last_sig);
		col += 2;
	}

	assert(col == 32);

	chan->peer->channel = chan;

	return ok;
}

/* List of fields to retrieve from the channels DB table, in the order
 * that wallet_stmt2channel understands and will parse correctly */
const char *channel_fields =
    "id, peer_id, short_channel_id, channel_config_local, "
    "channel_config_remote, state, funder, channel_flags, "
    "minimum_depth, "
    "next_index_local, next_index_remote, "
    "next_htlc_id, funding_tx_id, funding_tx_outnum, funding_satoshi, "
    "funding_locked_remote, push_msatoshi, msatoshi_local, "
    "fundingkey_remote, revocation_basepoint_remote, "
    "payment_basepoint_remote, "
    "delayed_payment_basepoint_remote, per_commit_remote, "
    "old_per_commit_remote, feerate_per_kw, shachain_remote_id, "
    "shutdown_scriptpubkey_remote, shutdown_keyidx_local, "
    "last_sent_commit_state, last_sent_commit_id, "
    "last_tx, last_sig";

bool wallet_channel_load(struct wallet *w, const u64 id,
			 struct wallet_channel *chan)
{
	bool ok;
	/* The explicit query that matches the columns and their order in
	 * wallet_stmt2channel. */
	sqlite3_stmt *stmt = db_query(
	    __func__, w->db, "SELECT %s FROM channels WHERE id=%" PRIu64 ";",
	    channel_fields, id);

	if (!stmt || sqlite3_step(stmt) != SQLITE_ROW) {
		sqlite3_finalize(stmt);
		return false;
	}

	ok = wallet_stmt2channel(w, stmt, chan);

	sqlite3_finalize(stmt);
	return ok;
}

bool wallet_channels_load_active(struct wallet *w, struct list_head *peers)
{
	bool ok = true;
	/* Channels are active if they have reached at least the
	 * opening state and they are not marked as complete */
	sqlite3_stmt *stmt = db_query(
	    __func__, w->db, "SELECT %s FROM channels WHERE state >= %d AND state != %d;",
	    channel_fields, OPENINGD, CLOSINGD_COMPLETE);

	int count = 0;
	while (ok && stmt && sqlite3_step(stmt) == SQLITE_ROW) {
		struct wallet_channel *c = talz(w, struct wallet_channel);
		ok &= wallet_stmt2channel(w, stmt, c);
		list_add(peers, &c->peer->list);
		count++;
	}
	log_debug(w->log, "Loaded %d channels from DB", count);
	sqlite3_finalize(stmt);
	return ok;
}

bool wallet_channel_config_save(struct wallet *w, struct channel_config *cc)
{
	bool ok = true;
	sqlite3_stmt *stmt;
	/* Is this an update? If not insert a stub first */
	if (!cc->id) {
		stmt = db_prepare(
			w->db,"INSERT INTO channel_configs DEFAULT VALUES;");
		ok &= db_exec_prepared(w->db, stmt);
		cc->id = sqlite3_last_insert_rowid(w->db->sql);
	}

	stmt = db_prepare(w->db, "UPDATE channel_configs SET"
			  "  dust_limit_satoshis=?,"
			  "  max_htlc_value_in_flight_msat=?,"
			  "  channel_reserve_satoshis=?,"
			  "  htlc_minimum_msat=?,"
			  "  to_self_delay=?,"
			  "  max_accepted_htlcs=?"
			  " WHERE id=?;");
	sqlite3_bind_int64(stmt, 1, cc->dust_limit_satoshis);
	sqlite3_bind_int64(stmt, 2, cc->max_htlc_value_in_flight_msat);
	sqlite3_bind_int64(stmt, 3, cc->channel_reserve_satoshis);
	sqlite3_bind_int64(stmt, 4, cc->htlc_minimum_msat);
	sqlite3_bind_int(stmt, 5, cc->to_self_delay);
	sqlite3_bind_int(stmt, 6, cc->max_accepted_htlcs);
	sqlite3_bind_int64(stmt, 7, cc->id);
	ok &= db_exec_prepared(w->db, stmt);

	return ok;
}

bool wallet_channel_config_load(struct wallet *w, const u64 id,
				struct channel_config *cc)
{
	bool ok = true;
	int col = 1;
	const char *query =
	    "SELECT id, dust_limit_satoshis, max_htlc_value_in_flight_msat, "
	    "channel_reserve_satoshis, htlc_minimum_msat, to_self_delay, "
	    "max_accepted_htlcs FROM channel_configs WHERE id=%" PRIu64 ";";
	sqlite3_stmt *stmt = db_query(__func__, w->db, query, id);
	if (!stmt || sqlite3_step(stmt) != SQLITE_ROW) {
		sqlite3_finalize(stmt);
		return false;
	}
	cc->id = id;
	cc->dust_limit_satoshis = sqlite3_column_int64(stmt, col++);
	cc->max_htlc_value_in_flight_msat = sqlite3_column_int64(stmt, col++);
	cc->channel_reserve_satoshis = sqlite3_column_int64(stmt, col++);
	cc->htlc_minimum_msat = sqlite3_column_int64(stmt, col++);
	cc->to_self_delay = sqlite3_column_int(stmt, col++);
	cc->max_accepted_htlcs = sqlite3_column_int(stmt, col++);
	assert(col == 7);
	sqlite3_finalize(stmt);
	return ok;
}

bool wallet_channel_save(struct wallet *w, struct wallet_channel *chan){
	bool should_commit, ok = true;
	struct peer *p = chan->peer;
	tal_t *tmpctx = tal_tmpctx(w);
	sqlite3_stmt *stmt;

	should_commit = db_begin_transaction(w->db);

	if (p->dbid == 0) {
		/* Need to store the peer first */
		stmt = db_prepare(w->db, "INSERT INTO peers (node_id) VALUES (?);");
		sqlite3_bind_pubkey(stmt, 1, &chan->peer->id);
		db_exec_prepared(w->db, stmt);
		p->dbid = sqlite3_last_insert_rowid(w->db->sql);
	}

	/* Insert a stub, that we can update, unifies INSERT and UPDATE paths */
	if (chan->id == 0) {
		stmt = db_prepare(w->db, "INSERT INTO channels (peer_id) VALUES (?);");
		sqlite3_bind_int64(stmt, 1, p->dbid);
		db_exec_prepared(w->db, stmt);
		chan->id = sqlite3_last_insert_rowid(w->db->sql);
	}

	/* Need to initialize the shachain first so we get an id */
	if (p->their_shachain.id == 0) {
		ok &= wallet_shachain_init(w, &p->their_shachain);
	}

	ok &= wallet_channel_config_save(w, &p->our_config);

	/* Now do the real update */
	stmt = db_prepare(w->db, tal_fmt(w, "UPDATE channels SET"
					 "  shachain_remote_id=?,"
					 "  short_channel_id=?,"
					 "  state=?,"
					 "  funder=?,"
					 "  channel_flags=?,"
					 "  minimum_depth=?,"
					 "  next_index_local=?,"
					 "  next_index_remote=?,"
					 "  next_htlc_id=?,"
					 "  funding_tx_id=?,"
					 "  funding_tx_outnum=?,"
					 "  funding_satoshi=?,"
					 "  funding_locked_remote=?,"
					 "  push_msatoshi=?,"
					 "  msatoshi_local=?,"
					 "  shutdown_scriptpubkey_remote=?,"
					 "  shutdown_keyidx_local=?,"
					 "  channel_config_local=?,"
					 "  last_tx=?, last_sig=?"
					 " WHERE id=?"));
	sqlite3_bind_int64(stmt, 1, p->their_shachain.id);
	if (p->scid)
		sqlite3_bind_short_channel_id(stmt, 2, p->scid);
	sqlite3_bind_int(stmt, 3, p->state);
	sqlite3_bind_int(stmt, 4, p->funder);
	sqlite3_bind_int(stmt, 5, p->channel_flags);
	sqlite3_bind_int(stmt, 6, p->minimum_depth);

	sqlite3_bind_int64(stmt, 7, p->next_index[LOCAL]);
	sqlite3_bind_int64(stmt, 8, p->next_index[REMOTE]);
	sqlite3_bind_int64(stmt, 9, p->next_htlc_id);

	if (p->funding_txid)
		sqlite3_bind_blob(stmt, 10, p->funding_txid, sizeof(*p->funding_txid), SQLITE_TRANSIENT);

	sqlite3_bind_int(stmt, 11, p->funding_outnum);
	sqlite3_bind_int64(stmt, 12, p->funding_satoshi);
	sqlite3_bind_int(stmt, 13, p->remote_funding_locked);
	sqlite3_bind_int64(stmt, 14, p->push_msat);

	if (p->our_msatoshi)
		sqlite3_bind_int64(stmt, 15, *p->our_msatoshi);

	if (p->remote_shutdown_scriptpubkey)
		sqlite3_bind_blob(stmt, 16, p->remote_shutdown_scriptpubkey,
				  tal_len(p->remote_shutdown_scriptpubkey),
				  SQLITE_TRANSIENT);

	sqlite3_bind_int64(stmt, 17, p->local_shutdown_idx);
	sqlite3_bind_int64(stmt, 18, p->our_config.id);
	if (p->last_tx)
		sqlite3_bind_tx(stmt, 19, p->last_tx);
	if (p->last_sig)
		sqlite3_bind_signature(stmt, 20, p->last_sig);
	sqlite3_bind_int64(stmt, 21, chan->id);
	db_exec_prepared(w->db, stmt);

	if (chan->peer->channel_info) {
		ok &= wallet_channel_config_save(w, &p->channel_info->their_config);
		stmt = db_prepare(w->db, "UPDATE channels SET"
				  "  fundingkey_remote=?,"
				  "  revocation_basepoint_remote=?,"
				  "  payment_basepoint_remote=?,"
				  "  delayed_payment_basepoint_remote=?,"
				  "  per_commit_remote=?,"
				  "  old_per_commit_remote=?,"
				  "  feerate_per_kw=?,"
				  "  channel_config_remote=?"
				  " WHERE id=?");
		sqlite3_bind_pubkey(stmt, 1,  &p->channel_info->remote_fundingkey);
		sqlite3_bind_pubkey(stmt, 2,  &p->channel_info->theirbase.revocation);
		sqlite3_bind_pubkey(stmt, 3,  &p->channel_info->theirbase.payment);
		sqlite3_bind_pubkey(stmt, 4,  &p->channel_info->theirbase.delayed_payment);
		sqlite3_bind_pubkey(stmt, 5,  &p->channel_info->remote_per_commit);
		sqlite3_bind_pubkey(stmt, 6,  &p->channel_info->old_remote_per_commit);
		sqlite3_bind_int(stmt, 7, p->channel_info->feerate_per_kw);
		sqlite3_bind_int64(stmt, 8, p->channel_info->their_config.id);
		sqlite3_bind_int64(stmt, 9, chan->id);
		ok &= db_exec_prepared(w->db, stmt);
	}

	/* If we have a last_sent_commit, store it */
	if (chan->peer->last_sent_commit) {
		stmt = db_prepare(w->db,
				  "UPDATE channels SET"
				  "  last_sent_commit_state=?,"
				  "  last_sent_commit_id=?"
				  " WHERE id=?");
		sqlite3_bind_int(stmt, 1, p->last_sent_commit->newstate);
		sqlite3_bind_int64(stmt, 2, p->last_sent_commit->id);
		sqlite3_bind_int64(stmt, 3, chan->id);
		ok &= db_exec_prepared(w->db, stmt);
	}

	if (should_commit) {
		if (ok)
			ok &= db_commit_transaction(w->db);
		else
			db_rollback_transaction(w->db);
	}
	tal_free(tmpctx);
      	return ok;
}

int wallet_extract_owned_outputs(struct wallet *w, const struct bitcoin_tx *tx,
				 u64 *total_satoshi)
{
	int num_utxos = 0;
	for (size_t output = 0; output < tal_count(tx->output); output++) {
		struct utxo *utxo;
		u32 index;
		bool is_p2sh;

		if (!wallet_can_spend(w, tx->output[output].script, &index,
				      &is_p2sh))
			continue;

		utxo = tal(w, struct utxo);
		utxo->keyindex = index;
		utxo->is_p2sh = is_p2sh;
		utxo->amount = tx->output[output].amount;
		utxo->status = output_state_available;
		bitcoin_txid(tx, &utxo->txid);
		utxo->outnum = output;
		log_debug(w->log, "Owning output %zu %"PRIu64" (%s) txid %s",
			  output, tx->output[output].amount,
			  is_p2sh ? "P2SH" : "SEGWIT",
			  type_to_string(ltmp, struct sha256_double,
					 &utxo->txid));

		if (!wallet_add_utxo(w, utxo, is_p2sh ? p2sh_wpkh : our_change)) {
			tal_free(utxo);
			return -1;
		}
		*total_satoshi += utxo->amount;
		num_utxos++;
	}
	return num_utxos;
}

bool wallet_htlc_save_in(struct wallet *wallet,
			 const struct wallet_channel *chan, struct htlc_in *in)
{
	bool ok = true;
	tal_t *tmpctx = tal_tmpctx(wallet);
	sqlite3_stmt *stmt;

	stmt = db_prepare(
		wallet->db,
		"INSERT INTO channel_htlcs ("
		" channel_id,"
		" channel_htlc_id, "
		" direction,"
		" msatoshi,"
		" cltv_expiry,"
		" payment_hash, "
		" payment_key,"
		" hstate,"
		" shared_secret,"
		" routing_onion) VALUES "
		"(?, ?, ?, ?, ?, ?, ?, ?, ?, ?);");

	sqlite3_bind_int64(stmt, 1, chan->id);
	sqlite3_bind_int64(stmt, 2, in->key.id);
	sqlite3_bind_int(stmt, 3, DIRECTION_INCOMING);
	sqlite3_bind_int64(stmt, 4, in->msatoshi);
	sqlite3_bind_int(stmt, 5, in->cltv_expiry);
	sqlite3_bind_sha256(stmt, 6, &in->payment_hash);

	if (in->preimage)
		sqlite3_bind_preimage(stmt, 7, in->preimage);
	sqlite3_bind_int(stmt, 8, in->hstate);

	sqlite3_bind_blob(stmt, 9, &in->shared_secret,
			  sizeof(in->shared_secret), SQLITE_TRANSIENT);

	sqlite3_bind_blob(stmt, 10, &in->onion_routing_packet,
			  sizeof(in->onion_routing_packet), SQLITE_TRANSIENT);

	ok = db_exec_prepared(wallet->db, stmt);
	tal_free(tmpctx);
	if (ok) {
		in->dbid = sqlite3_last_insert_rowid(wallet->db->sql);
	}
	return ok;
}

bool wallet_htlc_save_out(struct wallet *wallet,
			  const struct wallet_channel *chan,
			  struct htlc_out *out)
{
	bool ok = true;
	tal_t *tmpctx = tal_tmpctx(wallet);
	sqlite3_stmt *stmt;

	/* We absolutely need the incoming HTLC to be persisted before
	 * we can persist it's dependent */
	assert(out->in == NULL || out->in->dbid != 0);
	out->origin_htlc_id = out->in?out->in->dbid:0;

	stmt = db_prepare(
	    wallet->db,
	    "INSERT INTO channel_htlcs ("
	    " channel_id,"
	    " channel_htlc_id,"
	    " direction,"
	    " origin_htlc,"
	    " msatoshi,"
	    " cltv_expiry,"
	    " payment_hash,"
	    " payment_key,"
	    " hstate,"
	    " routing_onion) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?);");

	sqlite3_bind_int64(stmt, 1, chan->id);
	sqlite3_bind_int64(stmt, 2, out->key.id);
	sqlite3_bind_int(stmt, 3, DIRECTION_OUTGOING);
	if (out->in)
		sqlite3_bind_int64(stmt, 4, out->in->dbid);
	sqlite3_bind_int64(stmt, 5, out->msatoshi);
	sqlite3_bind_int(stmt, 6, out->cltv_expiry);
	sqlite3_bind_sha256(stmt, 7, &out->payment_hash);

	if (out->preimage)
		sqlite3_bind_preimage(stmt, 8,out->preimage);
	sqlite3_bind_int(stmt, 9, out->hstate);

	sqlite3_bind_blob(stmt, 10, &out->onion_routing_packet,
			  sizeof(out->onion_routing_packet), SQLITE_TRANSIENT);

	ok = db_exec_prepared(wallet->db, stmt);

	tal_free(tmpctx);
	if (ok) {
		out->dbid = sqlite3_last_insert_rowid(wallet->db->sql);
	}
	return ok;
}

bool wallet_htlc_update(struct wallet *wallet, const u64 htlc_dbid,
			const enum htlc_state new_state,
			const struct preimage *payment_key)
{
	bool ok = true;
	sqlite3_stmt *stmt;

	/* The database ID must be set by a previous call to
	 * `wallet_htlc_save_*` */
	assert(htlc_dbid);
	stmt = db_prepare(
		wallet->db,
		"UPDATE channel_htlcs SET hstate=?, payment_key=? WHERE id=?");

	sqlite3_bind_int(stmt, 1, new_state);
	sqlite3_bind_int64(stmt, 3, htlc_dbid);

	if (payment_key)
		sqlite3_bind_preimage(stmt, 2, payment_key);

	ok = db_exec_prepared(wallet->db, stmt);
	return ok;
}

static bool wallet_stmt2htlc_in(const struct wallet_channel *channel,
				sqlite3_stmt *stmt, struct htlc_in *in)
{
	bool ok = true;
	in->dbid = sqlite3_column_int64(stmt, 0);
	in->key.id = sqlite3_column_int64(stmt, 1);
	in->key.peer = channel->peer;
	in->msatoshi = sqlite3_column_int64(stmt, 2);
	in->cltv_expiry = sqlite3_column_int(stmt, 3);
	in->hstate = sqlite3_column_int(stmt, 4);

	sqlite3_column_sha256(stmt, 5, &in->payment_hash);

	assert(sqlite3_column_bytes(stmt, 6) == sizeof(struct secret));
	memcpy(&in->shared_secret, sqlite3_column_blob(stmt, 6),
	       sizeof(struct secret));

	if (sqlite3_column_type(stmt, 7) != SQLITE_NULL) {
		in->preimage = tal(in, struct preimage);
		sqlite3_column_preimage(stmt, 7, in->preimage);
	} else {
		in->preimage = NULL;
	}

	assert(sqlite3_column_bytes(stmt, 8) == sizeof(in->onion_routing_packet));
	memcpy(&in->onion_routing_packet, sqlite3_column_blob(stmt, 8),
	       sizeof(in->onion_routing_packet));

	in->failuremsg = NULL;
	in->malformed = 0;

	return ok;
}
static bool wallet_stmt2htlc_out(const struct wallet_channel *channel,
				sqlite3_stmt *stmt, struct htlc_out *out)
{
	bool ok = true;
	out->dbid = sqlite3_column_int64(stmt, 0);
	out->key.id = sqlite3_column_int64(stmt, 1);
	out->key.peer = channel->peer;
	out->msatoshi = sqlite3_column_int64(stmt, 2);
	out->cltv_expiry = sqlite3_column_int(stmt, 3);
	out->hstate = sqlite3_column_int(stmt, 4);
	sqlite3_column_sha256(stmt, 5, &out->payment_hash);

	if (sqlite3_column_type(stmt, 6) != SQLITE_NULL) {
		out->origin_htlc_id = sqlite3_column_int64(stmt, 6);
	} else {
		out->origin_htlc_id = 0;
	}

	if (sqlite3_column_type(stmt, 7) != SQLITE_NULL) {
		out->preimage = tal(out, struct preimage);
		sqlite3_column_preimage(stmt, 7, out->preimage);
	} else {
		out->preimage = NULL;
	}

	assert(sqlite3_column_bytes(stmt, 8) == sizeof(out->onion_routing_packet));
	memcpy(&out->onion_routing_packet, sqlite3_column_blob(stmt, 8),
	       sizeof(out->onion_routing_packet));

	out->failuremsg = NULL;
	out->malformed = 0;

	/* Need to defer wiring until we can look up all incoming
	 * htlcs, will wire using origin_htlc_id */
	out->in = NULL;

	return ok;
}

bool wallet_htlcs_load_for_channel(struct wallet *wallet,
				   struct wallet_channel *chan,
				   struct htlc_in_map *htlcs_in,
				   struct htlc_out_map *htlcs_out)
{
	bool ok = true;
	int incount = 0, outcount = 0;

	log_debug(wallet->log, "Loading HTLCs for channel %"PRIu64, chan->id);
	sqlite3_stmt *stmt = db_query(
	    __func__, wallet->db,
	    "SELECT id, channel_htlc_id, msatoshi, cltv_expiry, hstate, "
	    "payment_hash, shared_secret, payment_key, routing_onion FROM channel_htlcs WHERE "
	    "direction=%d AND channel_id=%" PRIu64 " AND hstate != %d",
	    DIRECTION_INCOMING, chan->id, SENT_REMOVE_ACK_REVOCATION);

	if (!stmt) {
		log_broken(wallet->log, "Could not select htlc_ins: %s", wallet->db->err);
		return false;
	}

	while (ok && stmt && sqlite3_step(stmt) == SQLITE_ROW) {
		struct htlc_in *in = tal(chan, struct htlc_in);
		ok &= wallet_stmt2htlc_in(chan, stmt, in);
		connect_htlc_in(htlcs_in, in);
		ok &=  htlc_in_check(in, "wallet_htlcs_load") != NULL;
		incount++;
	}
	sqlite3_finalize(stmt);

	stmt = db_query(
	    __func__, wallet->db,
	    "SELECT id, channel_htlc_id, msatoshi, cltv_expiry, hstate, "
	    "payment_hash, origin_htlc, payment_key, routing_onion FROM channel_htlcs WHERE "
	    "direction=%d AND channel_id=%" PRIu64 " AND hstate != %d",
	    DIRECTION_OUTGOING, chan->id, RCVD_REMOVE_ACK_REVOCATION);

	if (!stmt) {
		log_broken(wallet->log, "Could not select htlc_outs: %s", wallet->db->err);
		return false;
	}

	while (ok && stmt && sqlite3_step(stmt) == SQLITE_ROW) {
		struct htlc_out *out = tal(chan, struct htlc_out);
		ok &= wallet_stmt2htlc_out(chan, stmt, out);
		connect_htlc_out(htlcs_out, out);
		/* Cannot htlc_out_check because we haven't wired the
		 * dependencies in yet */
		outcount++;
	}
	sqlite3_finalize(stmt);
	log_debug(wallet->log, "Restored %d incoming and %d outgoing HTLCS", incount, outcount);

	return ok;
}

bool wallet_htlcs_reconnect(struct wallet *wallet,
			    struct htlc_in_map *htlcs_in,
			    struct htlc_out_map *htlcs_out)
{
	struct htlc_in_map_iter ini;
	struct htlc_out_map_iter outi;
	struct htlc_in *hin;
	struct htlc_out *hout;

	for (hout = htlc_out_map_first(htlcs_out, &outi); hout;
	     hout = htlc_out_map_next(htlcs_out, &outi)) {

		if (hout->origin_htlc_id == 0) {
			continue;
		}

		for (hin = htlc_in_map_first(htlcs_in, &ini); hin;
		     hin = htlc_in_map_next(htlcs_in, &ini)) {
			if (hout->origin_htlc_id == hin->dbid) {
				log_debug(wallet->log,
					  "Found corresponding htlc_in %" PRIu64
					  " for htlc_out %" PRIu64,
					  hin->dbid, hout->dbid);
				hout->in = hin;
				break;
			}
		}

		if (!hout->in) {
			log_broken(
			    wallet->log,
			    "Unable to find corresponding htlc_in %"PRIu64" for htlc_out %"PRIu64,
			    hout->origin_htlc_id, hout->dbid);
		}

	}
	return true;
}

bool wallet_invoice_save(struct wallet *wallet, struct invoice *inv)
{
	/* Need to use the lower level API of sqlite3 to bind
	 * label. Otherwise we'd need to implement sanitization of
	 * that string for sql injections... */
	sqlite3_stmt *stmt;
	if (!inv->id) {
		stmt = db_prepare(wallet->db,
			"INSERT INTO invoices (payment_hash, payment_key, state, msatoshi, label) VALUES (?, ?, ?, ?, ?);");
		if (!stmt) {
			log_broken(wallet->log, "Could not prepare statement: %s", wallet->db->err);
			return false;
		}

		sqlite3_bind_blob(stmt, 1, &inv->rhash, sizeof(inv->rhash), SQLITE_TRANSIENT);
		sqlite3_bind_blob(stmt, 2, &inv->r, sizeof(inv->r), SQLITE_TRANSIENT);
		sqlite3_bind_int(stmt, 3, inv->state);
		sqlite3_bind_int64(stmt, 4, inv->msatoshi);
		sqlite3_bind_text(stmt, 5, inv->label, strlen(inv->label), SQLITE_TRANSIENT);

		if (!db_exec_prepared(wallet->db, stmt)) {
			log_broken(wallet->log, "Could not exec prepared statement: %s", wallet->db->err);
			return false;
		}

		inv->id = sqlite3_last_insert_rowid(wallet->db->sql);
		return true;
	} else {
		stmt = db_prepare(wallet->db, "UPDATE invoices SET state=? WHERE id=?;");

		if (!stmt) {
			log_broken(wallet->log, "Could not prepare statement: %s", wallet->db->err);
			return false;
		}

		sqlite3_bind_int(stmt, 1, inv->state);
		sqlite3_bind_int64(stmt, 2, inv->id);

		if (!db_exec_prepared(wallet->db, stmt)) {
			log_broken(wallet->log, "Could not exec prepared statement: %s", wallet->db->err);
			return false;
		} else {
			return true;
		}
	}
}

static bool wallet_stmt2invoice(sqlite3_stmt *stmt, struct invoice *inv)
{
	inv->id = sqlite3_column_int64(stmt, 0);
	inv->state = sqlite3_column_int(stmt, 1);

	assert(sqlite3_column_bytes(stmt, 2) == sizeof(struct preimage));
	memcpy(&inv->r, sqlite3_column_blob(stmt, 2), sqlite3_column_bytes(stmt, 2));

	assert(sqlite3_column_bytes(stmt, 3) == sizeof(struct sha256));
	memcpy(&inv->rhash, sqlite3_column_blob(stmt, 3), sqlite3_column_bytes(stmt, 3));

	inv->label = tal_strndup(inv, sqlite3_column_blob(stmt, 4), sqlite3_column_bytes(stmt, 4));
	inv->msatoshi = sqlite3_column_int64(stmt, 5);
	return true;
}

bool wallet_invoices_load(struct wallet *wallet, struct invoices *invs)
{
	struct invoice *i;
	int count = 0;
	sqlite3_stmt *stmt = db_query(__func__, wallet->db,
				"SELECT id, state, payment_key, payment_hash, "
				"label, msatoshi FROM invoices;");
	if (!stmt) {
		log_broken(wallet->log, "Could not load invoices: %s", wallet->db->err);
		return false;
	}

	while (sqlite3_step(stmt) == SQLITE_ROW) {
		i = tal(invs, struct invoice);
		if (!wallet_stmt2invoice(stmt, i)) {
			log_broken(wallet->log, "Error deserializing invoice");
			return false;
		}
		invoice_add(invs, i);
		count++;
	}

	log_debug(wallet->log, "Loaded %d invoices from DB", count);
	return true;
}

bool wallet_invoice_remove(struct wallet *wallet, struct invoice *inv)
{
	sqlite3_stmt *stmt = db_prepare(wallet->db, "DELETE FROM invoices WHERE id=?");
	sqlite3_bind_int64(stmt, 1, inv->id);
	return db_exec_prepared(wallet->db, stmt) && sqlite3_changes(wallet->db->sql) == 1;
}

struct htlc_stub *wallet_htlc_stubs(tal_t *ctx, struct wallet *wallet,
				    struct wallet_channel *chan)
{
	struct htlc_stub *stubs;
	struct sha256 payment_hash;
	sqlite3_stmt *stmt = db_prepare(wallet->db,
		"SELECT channel_id, direction, cltv_expiry, payment_hash "
		"FROM channel_htlcs WHERE channel_id = ?;");

	if (!stmt) {
		log_broken(wallet->log, "Error preparing select: %s", wallet->db->err);
		return NULL;
	}
	sqlite3_bind_int64(stmt, 1, chan->id);

	stubs = tal_arr(ctx, struct htlc_stub, 0);

	while (sqlite3_step(stmt) == SQLITE_ROW) {
		int n = tal_count(stubs);
		tal_resize(&stubs, n+1);

		assert(sqlite3_column_int64(stmt, 0) == chan->id);

		/* FIXME: merge these two enums */
		stubs[n].owner = sqlite3_column_int(stmt, 1)==DIRECTION_INCOMING?REMOTE:LOCAL;
		stubs[n].cltv_expiry = sqlite3_column_int(stmt, 2);

		sqlite3_column_sha256(stmt, 3, &payment_hash);
		ripemd160(&stubs[n].ripemd, payment_hash.u.u8, sizeof(payment_hash.u));
	}
	sqlite3_finalize(stmt);
	return stubs;
}