Merge #957: Get genesis timestamp from bitcoind

f2c418f79a6fe8f1d6138b12af9fdc7303b4725d get genesis timestamp from bitcoind (pythcoiner)

Pull request description:

  fixes #904

ACKs for top commit:
  jp1ac4:
    ACK f2c418f79a.

Tree-SHA512: 7b1b7c13c21b657109ab0aab0d89deb47f5f6693f95687b86c219fc109ee304c38e3ebe865d071ebbbfa890a6a754c615f5dd70f2fe8c492bdea35d0394f36eb

src/bitcoin/mod.rs

@@ -40,6 +40,8 @@ impl fmt::Display for BlockChainTip {
 
 /// Our Bitcoin backend.
 pub trait BitcoinInterface: Send {
+    fn genesis_block_timestamp(&self) -> u32;
+
     fn genesis_block(&self) -> BlockChainTip;
 
     /// Get the progress of the block chain synchronization.
@@ -124,6 +126,15 @@ pub trait BitcoinInterface: Send {
 }
 
 impl BitcoinInterface for d::BitcoinD {
+    fn genesis_block_timestamp(&self) -> u32 {
+        self.get_block_stats(
+            self.get_block_hash(0)
+                .expect("Genesis block hash must always be there"),
+        )
+        .expect("Genesis block must always be there")
+        .time
+    }
+
     fn genesis_block(&self) -> BlockChainTip {
         let height = 0;
         let hash = self
@@ -379,6 +390,10 @@ impl BitcoinInterface for d::BitcoinD {
 
 // FIXME: do we need to repeat the entire trait implemenation? Isn't there a nicer way?
 impl BitcoinInterface for sync::Arc<sync::Mutex<dyn BitcoinInterface + 'static>> {
+    fn genesis_block_timestamp(&self) -> u32 {
+        self.lock().unwrap().genesis_block_timestamp()
+    }
+
     fn genesis_block(&self) -> BlockChainTip {
         self.lock().unwrap().genesis_block()
     }

src/commands/mod.rs

@@ -33,9 +33,6 @@ use miniscript::{
 };
 use serde::{Deserialize, Serialize};
 
-// Timestamp in the header of the genesis block. Used for sanity checks.
-const MAINNET_GENESIS_TIME: u32 = 1231006505;
-
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum CommandError {
     NoOutpointForSelfSend,
@@ -953,13 +950,14 @@ impl DaemonControl {
     /// The date must be after the genesis block time and before the current tip blocktime.
     pub fn start_rescan(&self, timestamp: u32) -> Result<(), CommandError> {
         let mut db_conn = self.db.connection();
+        let genesis_timestamp = self.bitcoin.genesis_block_timestamp();
 
         let future_timestamp = self
             .bitcoin
             .tip_time()
             .map(|t| timestamp >= t)
             .unwrap_or(false);
-        if timestamp < MAINNET_GENESIS_TIME || future_timestamp {
+        if timestamp < genesis_timestamp || future_timestamp {
             return Err(CommandError::InsaneRescanTimestamp(timestamp));
         }
         if db_conn.rescan_timestamp().is_some() || self.bitcoin.rescan_progress().is_some() {

src/testutils.rs

@@ -34,6 +34,10 @@ impl DummyBitcoind {
 }
 
 impl BitcoinInterface for DummyBitcoind {
+    fn genesis_block_timestamp(&self) -> u32 {
+        1231006505
+    }
+
     fn genesis_block(&self) -> BlockChainTip {
         let hash = bitcoin::BlockHash::from_str(
             "000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f",

tests/test_rpc.py

@@ -628,10 +628,15 @@ def test_start_rescan(lianad, bitcoind):
     with pytest.raises(RpcError, match="Insane timestamp.*"):
         lianad.rpc.startrescan(future_timestamp)
     assert lianad.rpc.getinfo()["rescan_progress"] is None
-    prebitcoin_timestamp = 1231006505 - 1
+    block_hash = bitcoind.rpc.getblockhash(0)
+    genesis_timestamp = bitcoind.rpc.getblock(block_hash)["time"]
+    prebitcoin_timestamp = genesis_timestamp - 1
     with pytest.raises(RpcError, match="Insane timestamp."):
         lianad.rpc.startrescan(prebitcoin_timestamp)
     assert lianad.rpc.getinfo()["rescan_progress"] is None
+    # we can rescan from genesis block
+    lianad.rpc.startrescan(genesis_timestamp)
+    wait_for(lambda: lianad.rpc.getinfo()["rescan_progress"] is None)
 
     # First, get some coins
     for _ in range(10):