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, 46 insertions, 2 deletions

diff --git a/src/cryptonote_protocol/cryptonote_protocol_defs.h b/src/cryptonote_protocol/cryptonote_protocol_defs.h
index b2f8da399..3d594bf83 100644
--- a/src/cryptonote_protocol/cryptonote_protocol_defs.h
+++ b/src/cryptonote_protocol/cryptonote_protocol_defs.h
@@ -116,14 +116,51 @@ namespace cryptonote
   /************************************************************************/
   /*                                                                      */
   /************************************************************************/
+  struct tx_blob_entry
+  {
+    blobdata blob;
+    crypto::hash prunable_hash;
+    BEGIN_KV_SERIALIZE_MAP()
+      KV_SERIALIZE(blob)
+      KV_SERIALIZE_VAL_POD_AS_BLOB(prunable_hash)
+    END_KV_SERIALIZE_MAP()
+
+    tx_blob_entry(const blobdata &bd = {}, const crypto::hash &h = crypto::null_hash): blob(bd), prunable_hash(h) {}
+  };
   struct block_complete_entry
   {
+    bool pruned;
     blobdata block;
-    std::vector<blobdata> txs;
+    uint64_t block_weight;
+    std::vector<tx_blob_entry> txs;
     BEGIN_KV_SERIALIZE_MAP()
+      KV_SERIALIZE_OPT(pruned, false)
       KV_SERIALIZE(block)
-      KV_SERIALIZE(txs)
+      KV_SERIALIZE_OPT(block_weight, (uint64_t)0)
+      if (this_ref.pruned)
+      {
+        KV_SERIALIZE(txs)
+      }
+      else
+      {
+        std::vector<blobdata> txs;
+        if (is_store)
+        {
+          txs.reserve(this_ref.txs.size());
+          for (const auto &e: this_ref.txs) txs.push_back(e.blob);
+        }
+        epee::serialization::selector<is_store>::serialize(txs, stg, hparent_section, "txs");
+        if (!is_store)
+        {
+          block_complete_entry &self = const_cast<block_complete_entry&>(this_ref);
+          self.txs.clear();
+          self.txs.reserve(txs.size());
+          for (auto &e: txs) self.txs.push_back({std::move(e), crypto::null_hash});
+        }
+      }
     END_KV_SERIALIZE_MAP()
+
+    block_complete_entry(): pruned(false) {}
   };
 
 
@@ -176,8 +213,11 @@ namespace cryptonote
     struct request_t
     {
       std::vector<crypto::hash> blocks;
+      bool prune;
+
       BEGIN_KV_SERIALIZE_MAP()
         KV_SERIALIZE_CONTAINER_POD_AS_BLOB(blocks)
+        KV_SERIALIZE_OPT(prune, false)
       END_KV_SERIALIZE_MAP()
     };
     typedef epee::misc_utils::struct_init<request_t> request;
@@ -229,9 +269,11 @@ namespace cryptonote
     struct request_t
     {
       std::list<crypto::hash> block_ids; /*IDs of the first 10 blocks are sequential, next goes with pow(2,n) offset, like 2, 4, 8, 16, 32, 64 and so on, and the last one is always genesis block */
+      bool prune;
 
       BEGIN_KV_SERIALIZE_MAP()
         KV_SERIALIZE_CONTAINER_POD_AS_BLOB(block_ids)
+        KV_SERIALIZE_OPT(prune, false)
       END_KV_SERIALIZE_MAP()
     };
     typedef epee::misc_utils::struct_init<request_t> request;
@@ -248,6 +290,7 @@ namespace cryptonote
       uint64_t cumulative_difficulty;
       uint64_t cumulative_difficulty_top64;
       std::vector<crypto::hash> m_block_ids;
+      std::vector<uint64_t> m_block_weights;
 
       BEGIN_KV_SERIALIZE_MAP()
         KV_SERIALIZE(start_height)
@@ -255,6 +298,7 @@ namespace cryptonote
         KV_SERIALIZE(cumulative_difficulty)
         KV_SERIALIZE(cumulative_difficulty_top64)
         KV_SERIALIZE_CONTAINER_POD_AS_BLOB(m_block_ids)
+        KV_SERIALIZE_CONTAINER_POD_AS_BLOB(m_block_weights)
       END_KV_SERIALIZE_MAP()
     };
     typedef epee::misc_utils::struct_init<request_t> request;