rpc: Expose ProcessNewBlockHeaders

3 files changed, 54 insertions, 1 deletions

diff --git a/src/core_io.h b/src/core_io.h
index ee323a22ee..d53a45c0cb 100644
--- a/src/core_io.h
+++ b/src/core_io.h
@@ -11,6 +11,7 @@
 #include <vector>
 
 class CBlock;
+class CBlockHeader;
 class CScript;
 class CTransaction;
 struct CMutableTransaction;
@@ -23,6 +24,7 @@ CScript ParseScript(const std::string& s);
 std::string ScriptToAsmStr(const CScript& script, const bool fAttemptSighashDecode = false);
 bool DecodeHexTx(CMutableTransaction& tx, const std::string& hex_tx, bool try_no_witness = false, bool try_witness = true);
 bool DecodeHexBlk(CBlock&, const std::string& strHexBlk);
+bool DecodeHexBlockHeader(CBlockHeader&, const std::string& hex_header);
 uint256 ParseHashStr(const std::string&, const std::string& strName);
 std::vector<unsigned char> ParseHexUV(const UniValue& v, const std::string& strName);
 bool DecodePSBT(PartiallySignedTransaction& psbt, const std::string& base64_tx, std::string& error);
diff --git a/src/core_read.cpp b/src/core_read.cpp
index a5df45aba1..b02016c014 100644
--- a/src/core_read.cpp
+++ b/src/core_read.cpp
@@ -145,6 +145,20 @@ bool DecodeHexTx(CMutableTransaction& tx, const std::string& hex_tx, bool try_no
     return false;
 }
 
+bool DecodeHexBlockHeader(CBlockHeader& header, const std::string& hex_header)
+{
+    if (!IsHex(hex_header)) return false;
+
+    const std::vector<unsigned char> header_data{ParseHex(hex_header)};
+    CDataStream ser_header(header_data, SER_NETWORK, PROTOCOL_VERSION);
+    try {
+        ser_header >> header;
+    } catch (const std::exception&) {
+        return false;
+    }
+    return true;
+}
+
 bool DecodeHexBlk(CBlock& block, const std::string& strHexBlk)
 {
     if (!IsHex(strHexBlk))
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index e751587dc7..623b0bd86a 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -10,7 +10,6 @@
 #include <consensus/params.h>
 #include <consensus/validation.h>
 #include <core_io.h>
-#include <validation.h>
 #include <key_io.h>
 #include <miner.h>
 #include <net.h>
@@ -23,6 +22,7 @@
 #include <txmempool.h>
 #include <util.h>
 #include <utilstrencodings.h>
+#include <validation.h>
 #include <validationinterface.h>
 #include <warnings.h>
 
@@ -763,6 +763,42 @@ static UniValue submitblock(const JSONRPCRequest& request)
     return BIP22ValidationResult(sc.state);
 }
 
+static UniValue submitheader(const JSONRPCRequest& request)
+{
+    if (request.fHelp || request.params.size() != 1) {
+        throw std::runtime_error(
+            "submitheader \"hexdata\"\n"
+            "\nDecode the given hexdata as a header and submit it as a candidate chain tip if valid."
+            "\nThrows when the header is invalid.\n"
+            "\nArguments\n"
+            "1. \"hexdata\"        (string, required) the hex-encoded block header data\n"
+            "\nResult:\n"
+            "None"
+            "\nExamples:\n" +
+            HelpExampleCli("submitheader", "\"aabbcc\"") +
+            HelpExampleRpc("submitheader", "\"aabbcc\""));
+    }
+
+    CBlockHeader h;
+    if (!DecodeHexBlockHeader(h, request.params[0].get_str())) {
+        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block header decode failed");
+    }
+    {
+        LOCK(cs_main);
+        if (!LookupBlockIndex(h.hashPrevBlock)) {
+            throw JSONRPCError(RPC_VERIFY_ERROR, "Must submit previous header (" + h.hashPrevBlock.GetHex() + ") first");
+        }
+    }
+
+    CValidationState state;
+    ProcessNewBlockHeaders({h}, state, Params(), /* ppindex */ nullptr, /* first_invalid */ nullptr);
+    if (state.IsValid()) return NullUniValue;
+    if (state.IsError()) {
+        throw JSONRPCError(RPC_VERIFY_ERROR, FormatStateMessage(state));
+    }
+    throw JSONRPCError(RPC_VERIFY_ERROR, state.GetRejectReason());
+}
+
 static UniValue estimatefee(const JSONRPCRequest& request)
 {
     throw JSONRPCError(RPC_METHOD_DEPRECATED, "estimatefee was removed in v0.17.\n"
@@ -940,6 +976,7 @@ static const CRPCCommand commands[] =
     { "mining",             "prioritisetransaction",  &prioritisetransaction,  {"txid","dummy","fee_delta"} },
     { "mining",             "getblocktemplate",       &getblocktemplate,       {"template_request"} },
     { "mining",             "submitblock",            &submitblock,            {"hexdata","dummy"} },
+    { "mining",             "submitheader",           &submitheader,           {"hexdata"} },
 
 
     { "generating",         "generatetoaddress",      &generatetoaddress,      {"nblocks","address","maxtries"} },