monerod can now sync from pruned blocks

If the peer (whether pruned or not itself) supports sending pruned blocks
to syncing nodes, the pruned version will be sent along with the hash
of the pruned data and the block weight. The original tx hashes can be
reconstructed from the pruned txes and theur prunable data hash. Those
hashes and the block weights are hashes and checked against the set of
precompiled hashes, ensuring the data we received is the original data.
It is currently not possible to use this system when not using the set
of precompiled hashes, since block weights can not otherwise be checked
for validity.

This is off by default for now, and is enabled by --sync-pruned-blocks

1 files changed, 24 insertions, 8 deletions

diff --git a/src/cryptonote_core/blockchain.h b/src/cryptonote_core/blockchain.h
index f58059a6d..fff564d24 100644
--- a/src/cryptonote_core/blockchain.h
+++ b/src/cryptonote_core/blockchain.h
@@ -381,13 +381,14 @@ namespace cryptonote
      *
      * @param qblock_ids the foreign chain's "short history" (see get_short_chain_history)
      * @param hashes the hashes to be returned, return-by-reference
+     * @param weights the block weights to be returned, return-by-reference
      * @param start_height the start height, return-by-reference
      * @param current_height the current blockchain height, return-by-reference
      * @param clip_pruned whether to constrain results to unpruned data
      *
      * @return true if a block found in common, else false
      */
-    bool find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, std::vector<crypto::hash>& hashes, uint64_t& start_height, uint64_t& current_height, bool clip_pruned) const;
+    bool find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, std::vector<crypto::hash>& hashes, std::vector<uint64_t>* weights, uint64_t& start_height, uint64_t& current_height, bool clip_pruned) const;
 
     /**
      * @brief get recent block hashes for a foreign chain
@@ -397,11 +398,12 @@ namespace cryptonote
      * BLOCKS_IDS_SYNCHRONIZING_DEFAULT_COUNT additional (more recent) hashes.
      *
      * @param qblock_ids the foreign chain's "short history" (see get_short_chain_history)
+     * @param clip_pruned clip pruned blocks if true, include them otherwise
      * @param resp return-by-reference the split height and subsequent blocks' hashes
      *
      * @return true if a block found in common, else false
      */
-    bool find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, NOTIFY_RESPONSE_CHAIN_ENTRY::request& resp) const;
+    bool find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, bool clip_pruned, NOTIFY_RESPONSE_CHAIN_ENTRY::request& resp) const;
 
     /**
      * @brief find the most recent common point between ours and a foreign chain
@@ -675,8 +677,8 @@ namespace cryptonote
      *
      * @return false if an unexpected exception occurs, else true
      */
-    template<class t_ids_container, class t_tx_container, class t_missed_container>
-    bool get_transactions_blobs(const t_ids_container& txs_ids, t_tx_container& txs, t_missed_container& missed_txs, bool pruned = false) const;
+    bool get_transactions_blobs(const std::vector<crypto::hash>& txs_ids, std::vector<cryptonote::blobdata>& txs, std::vector<crypto::hash>& missed_txs, bool pruned = false) const;
+    bool get_transactions_blobs(const std::vector<crypto::hash>& txs_ids, std::vector<tx_blob_entry>& txs, std::vector<crypto::hash>& missed_txs, bool pruned = false) const;
     template<class t_ids_container, class t_tx_container, class t_missed_container>
     bool get_split_transactions_blobs(const t_ids_container& txs_ids, t_tx_container& txs, t_missed_container& missed_txs) const;
     template<class t_ids_container, class t_tx_container, class t_missed_container>
@@ -963,9 +965,8 @@ namespace cryptonote
     cryptonote::blobdata get_txpool_tx_blob(const crypto::hash& txid) const;
     bool for_all_txpool_txes(std::function<bool(const crypto::hash&, const txpool_tx_meta_t&, const cryptonote::blobdata*)>, bool include_blob = false, bool include_unrelayed_txes = true) const;
 
-    bool is_within_compiled_block_hash_area(uint64_t height) const;
     bool is_within_compiled_block_hash_area() const { return is_within_compiled_block_hash_area(m_db->height()); }
-    uint64_t prevalidate_block_hashes(uint64_t height, const std::vector<crypto::hash> &hashes);
+    uint64_t prevalidate_block_hashes(uint64_t height, const std::vector<crypto::hash> &hashes, const std::vector<uint64_t> &weights);
     uint32_t get_blockchain_pruning_seed() const { return m_db->get_blockchain_pruning_seed(); }
     bool prune_blockchain(uint32_t pruning_seed = 0);
     bool update_blockchain_pruning();
@@ -995,6 +996,21 @@ namespace cryptonote
      */
     void pop_blocks(uint64_t nblocks);
 
+    /**
+     * @brief checks whether a given block height is included in the precompiled block hash area
+     *
+     * @param height the height to check for
+     */
+    bool is_within_compiled_block_hash_area(uint64_t height) const;
+
+    /**
+     * @brief checks whether we have known weights for the given block heights
+     *
+     * @param height the start height to check for
+     * @param nblocks how many blocks to check from that height
+     */
+    bool has_block_weights(uint64_t height, uint64_t nblocks) const;
+
 #ifndef IN_UNIT_TESTS
   private:
 #endif
@@ -1022,8 +1038,8 @@ namespace cryptonote
     std::unordered_map<crypto::hash, crypto::hash> m_blocks_longhash_table;
 
     // SHA-3 hashes for each block and for fast pow checking
-    std::vector<crypto::hash> m_blocks_hash_of_hashes;
-    std::vector<crypto::hash> m_blocks_hash_check;
+    std::vector<std::pair<crypto::hash, crypto::hash>> m_blocks_hash_of_hashes;
+    std::vector<std::pair<crypto::hash, uint64_t>> m_blocks_hash_check;
     std::vector<crypto::hash> m_blocks_txs_check;
 
     blockchain_db_sync_mode m_db_sync_mode;