From 667a7636595b31e8fdc3eff6d2b8dba0bd9c4221 Mon Sep 17 00:00:00 2001
From: Christian Decker <decker.christian@gmail.com>
Date: Thu, 7 May 2020 10:12:40 +0930
Subject: [PATCH] db: Add a table to track the penalty_bases for revocations

---
 wallet/db.c     |  8 +++++++
 wallet/wallet.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++
 wallet/wallet.h | 25 ++++++++++++++++++++
 3 files changed, 94 insertions(+)

diff --git a/wallet/db.c b/wallet/db.c
index 673d4d88a..ff1423802 100644
--- a/wallet/db.c
+++ b/wallet/db.c
@@ -599,6 +599,14 @@ static struct migration dbmigrations[] = {
     {SQL("ALTER TABLE channel_htlcs ADD localfailmsg BLOB;"), NULL},
     {SQL("UPDATE channel_htlcs SET localfailmsg=decode('2002', 'hex') WHERE malformed_onion != 0 AND direction = 1;"), NULL},
     {SQL("ALTER TABLE channels ADD our_funding_satoshi BIGINT DEFAULT 0;"), migrate_our_funding},
+    {SQL("CREATE TABLE penalty_bases ("
+	 "  channel_id BIGINT REFERENCES channels(id) ON DELETE CASCADE"
+	 ", commitnum BIGINT"
+	 ", txid BLOB"
+	 ", outnum INTEGER"
+	 ", amount BIGINT"
+	 ", PRIMARY KEY (channel_id, commitnum)"
+	 ");"), NULL},
 };
 
 /* Leak tracking. */
diff --git a/wallet/wallet.c b/wallet/wallet.c
index 662a4f10f..1a3532860 100644
--- a/wallet/wallet.c
+++ b/wallet/wallet.c
@@ -3786,3 +3786,64 @@ struct wallet_transaction *wallet_transactions_get(struct wallet *w, const tal_t
 	tal_free(stmt);
 	return txs;
 }
+
+void wallet_penalty_base_add(struct wallet *w, u64 chan_id,
+			     const struct penalty_base *pb)
+{
+	struct db_stmt *stmt;
+	stmt = db_prepare_v2(w->db,
+			     SQL("INSERT INTO penalty_bases ("
+				 "  channel_id"
+				 ", commitnum"
+				 ", txid"
+				 ", outnum"
+				 ", amount"
+				 ") VALUES (?, ?, ?, ?, ?);"));
+
+	db_bind_u64(stmt, 0, chan_id);
+	db_bind_u64(stmt, 1, pb->commitment_num);
+	db_bind_txid(stmt, 2, &pb->txid);
+	db_bind_int(stmt, 3, pb->outnum);
+	db_bind_amount_sat(stmt, 4, &pb->amount);
+
+	db_exec_prepared_v2(take(stmt));
+}
+
+struct penalty_base *wallet_penalty_base_load_for_channel(const tal_t *ctx,
+							  struct wallet *w,
+							  u64 chan_id)
+{
+	struct db_stmt *stmt;
+	struct penalty_base *res = tal_arr(ctx, struct penalty_base, 0);
+	stmt = db_prepare_v2(
+		w->db,
+		SQL("SELECT commitnum, txid, outnum, amount "
+		    "FROM penalty_bases "
+		    "WHERE channel_id = ?"));
+
+	db_bind_u64(stmt, 0, chan_id);
+	db_query_prepared(stmt);
+
+	while (db_step(stmt)) {
+		struct penalty_base pb;
+		pb.commitment_num = db_column_u64(stmt, 0);
+		db_column_txid(stmt, 1, &pb.txid);
+		pb.outnum = db_column_int(stmt, 2);
+		db_column_amount_sat(stmt, 3, &pb.amount);
+		tal_arr_expand(&res, pb);
+	}
+	tal_free(stmt);
+	return res;
+}
+
+void wallet_penalty_base_delete(struct wallet *w, u64 chan_id, u64 commitnum)
+{
+	struct db_stmt *stmt;
+	stmt = db_prepare_v2(
+		w->db,
+		SQL("DELETE FROM penalty_bases "
+		    "WHERE channel_id = ? AND commitnum = ?"));
+	db_bind_u64(stmt, 0, chan_id);
+	db_bind_u64(stmt, 1, commitnum);
+	db_exec_prepared_v2(take(stmt));
+}
diff --git a/wallet/wallet.h b/wallet/wallet.h
index 40aead5ca..911367deb 100644
--- a/wallet/wallet.h
+++ b/wallet/wallet.h
@@ -10,6 +10,7 @@
 #include <ccan/list/list.h>
 #include <ccan/tal/tal.h>
 #include <common/channel_config.h>
+#include <common/penalty_base.h>
 #include <common/utxo.h>
 #include <common/wallet.h>
 #include <lightningd/bitcoind.h>
@@ -1251,4 +1252,28 @@ struct wallet_transaction *wallet_transactions_get(struct wallet *w, const tal_t
  */
 void wallet_filteredblock_add(struct wallet *w, const struct filteredblock *fb);
 
+/**
+ * Store a penalty base in the database.
+ *
+ * Required to eventually create a penalty transaction when we get a
+ * revocation.
+ */
+void wallet_penalty_base_add(struct wallet *w, u64 chan_id,
+			     const struct penalty_base *pb);
+
+/**
+ * Retrieve all pending penalty bases for a given channel.
+ *
+ * This list should stay relatively small since we remove items from it as we
+ * get revocations. We retrieve this list whenever we start a new `channeld`.
+ */
+struct penalty_base *wallet_penalty_base_load_for_channel(const tal_t *ctx,
+							  struct wallet *w,
+							  u64 chan_id);
+
+/**
+ * Delete a penalty_base, after we created and delivered it to the hook.
+ */
+void wallet_penalty_base_delete(struct wallet *w, u64 chan_id, u64 commitnum);
+
 #endif /* LIGHTNING_WALLET_WALLET_H */