Merge bitcoin/bitcoin#30793: rpc: add getorphantxs

98c1536852d1de9a978b11046e7414e79ed40b46 test: add getorphantxs tests (tdb3)
93f48fceb7dd332ef980ce890ff7750b995d6077 test: add tx_in_orphanage() (tdb3)
34a9c10e8cdb3e9cd40fc3a420df8f73e0208a48 rpc: add getorphantxs (tdb3)
f511ff3654d999951a64098c8a9f2f8e29771dad refactor: move verbosity parsing to rpc/util (tdb3)
532491faf1aa90053af52cbedce403b9eccf0bc3 net: add GetOrphanTransactions() to PeerManager (tdb3)
91b65adff2aaf16f42c5ccca6e16b951e0e84f9a refactor: add OrphanTxBase for external use (tdb3)

Pull request description:

  This PR adds a new hidden rpc, `getorphantxs`, that provides the caller with a list of orphan transactions.  This rpc may be helpful when checking orphan behavior/scenarios (e.g. in tests like `p2p_orphan_handling`) or providing additional data for statistics/visualization.

  ```
  getorphantxs ( verbosity )

  Shows transactions in the tx orphanage.

  EXPERIMENTAL warning: this call may be changed in future releases.

  Arguments:
  1. verbosity    (numeric, optional, default=0) 0 for an array of txids (may contain duplicates), 1 for an array of objects with tx details, and 2 for details from (1) and tx hex

  Result (for verbose = 0):
  [           (json array)
    "hex",    (string) The transaction hash in hex
    ...
  ]

  Result (for verbose = 1):
  [                          (json array)
    {                        (json object)
      "txid" : "hex",        (string) The transaction hash in hex
      "wtxid" : "hex",       (string) The transaction witness hash in hex
      "bytes" : n,           (numeric) The serialized transaction size in bytes
      "vsize" : n,           (numeric) The virtual transaction size as defined in BIP 141. This is different from actual serialized size for witness transactions as witness data is discounted.
      "weight" : n,          (numeric) The transaction weight as defined in BIP 141.
      "expiration" : xxx,    (numeric) The orphan expiration time expressed in UNIX epoch time
      "from" : [             (json array)
        n,                   (numeric) Peer ID
        ...
      ]
    },
    ...
  ]

  Result (for verbose = 2):
  [                          (json array)
    {                        (json object)
      "txid" : "hex",        (string) The transaction hash in hex
      "wtxid" : "hex",       (string) The transaction witness hash in hex
      "bytes" : n,           (numeric) The serialized transaction size in bytes
      "vsize" : n,           (numeric) The virtual transaction size as defined in BIP 141. This is different from actual serialized size for witness transactions as witness data is discounted.
      "weight" : n,          (numeric) The transaction weight as defined in BIP 141.
      "expiration" : xxx,    (numeric) The orphan expiration time expressed in UNIX epoch time
      "from" : [             (json array)
        n,                   (numeric) Peer ID
        ...
      ],
      "hex" : "hex"          (string) The serialized, hex-encoded transaction data
    },
    ...
  ]

  Examples:
  > bitcoin-cli getorphantxs 2
  > curl --user myusername --data-binary '{"jsonrpc": "2.0", "id": "curltest", "method": "getorphantxs", "params": [2]}' -H 'content-type: application/json' http://127.0.0.1:8332/
  ```
  ```
  $ build/src/bitcoin-cli getorphantxs 2
  [
    {
      "txid": "50128aac5deab548228d74d846675ad4def91cd92453d81a2daa778df12a63f2",
      "wtxid": "bb61659336f59fcf23acb47c05dc4bbea63ab533a98c412f3a12cb813308d52c",
      "bytes": 133,
      "vsize": 104,
      "weight": 415,
      "expiration": 1725663854,
      "from": [
        1
      ],
      "hex": "020000000001010b992959eaa2018bbf31a4a3f9aa30896a8144dbd5cfaf263bf07c0845a3a6620000000000000000000140fe042a010000002251202913b252fe537830f843bfdc5fa7d20ba48639a87c86ff837b92d083c55ad7c102015121c0000000000000000000000000000000000000000000000000000000000000000100000000"
    },
    {
      "txid": "330bb7f701604a40ade20aa129e9a3eb8a7bf024e599084ca1026d3222b9f8a1",
      "wtxid": "b7651f7d4c1a40c4d01f6a1e43a121967091fa0f56bb460146c1c5c068e824f6",
      "bytes": 133,
      "vsize": 104,
      "weight": 415,
      "expiration": 1725663854,
      "from": [
        2
      ],
      "hex": "020000000001013600adfe41e0ebd2454838963d270916d2b47239c9eebb93a992b720d3589a080000000000000000000140fe042a010000002251202913b252fe537830f843bfdc5fa7d20ba48639a87c86ff837b92d083c55ad7c102015121c0000000000000000000000000000000000000000000000000000000000000000100000000"
    }
  ]
  ```

ACKs for top commit:
  glozow:
    reACK 98c1536852d
  hodlinator:
    re-ACK 98c1536852d1de9a978b11046e7414e79ed40b46
  danielabrozzoni:
    ACK 98c1536852d1de9a978b11046e7414e79ed40b46
  pablomartin4btc:
    tACK 98c1536852d1de9a978b11046e7414e79ed40b46
  itornaza:
    reACK 98c1536852d1de9a978b11046e7414e79ed40b46

Tree-SHA512: 66075f9faa83748350b87397302100d08af92cbef5fadb27f2b4903f028c08020bf34a23e17262b41abb3f379ca9f46cf6cd5459b8681f2b83bffbbaf3c03ff9

11 files changed, 157 insertions, 20 deletions

diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index b7d0f5360d..be16884011 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -515,6 +515,7 @@ public:
     std::optional<std::string> FetchBlock(NodeId peer_id, const CBlockIndex& block_index) override
         EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
     bool GetNodeStateStats(NodeId nodeid, CNodeStateStats& stats) const override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
+    std::vector<TxOrphanage::OrphanTxBase> GetOrphanTransactions() override EXCLUSIVE_LOCKS_REQUIRED(!m_tx_download_mutex);
     PeerManagerInfo GetInfo() const override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
     void SendPings() override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
     void RelayTransaction(const uint256& txid, const uint256& wtxid) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
@@ -1917,6 +1918,12 @@ bool PeerManagerImpl::GetNodeStateStats(NodeId nodeid, CNodeStateStats& stats) c
     return true;
 }
 
+std::vector<TxOrphanage::OrphanTxBase> PeerManagerImpl::GetOrphanTransactions()
+{
+    LOCK(m_tx_download_mutex);
+    return m_orphanage.GetOrphanTransactions();
+}
+
 PeerManagerInfo PeerManagerImpl::GetInfo() const
 {
     return PeerManagerInfo{
diff --git a/src/net_processing.h b/src/net_processing.h
index ccacd15e42..0d2dc59c5a 100644
--- a/src/net_processing.h
+++ b/src/net_processing.h
@@ -7,6 +7,7 @@
 #define BITCOIN_NET_PROCESSING_H
 
 #include <net.h>
+#include <txorphanage.h>
 #include <validationinterface.h>
 
 #include <chrono>
@@ -99,6 +100,8 @@ public:
     /** Get statistics from node state */
     virtual bool GetNodeStateStats(NodeId nodeid, CNodeStateStats& stats) const = 0;
 
+    virtual std::vector<TxOrphanage::OrphanTxBase> GetOrphanTransactions() = 0;
+
     /** Get peer manager info. */
     virtual PeerManagerInfo GetInfo() const = 0;
 
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index c4fc06b34e..360f24ec55 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -766,14 +766,7 @@ static RPCHelpMan getblock()
 {
     uint256 hash(ParseHashV(request.params[0], "blockhash"));
 
-    int verbosity = 1;
-    if (!request.params[1].isNull()) {
-        if (request.params[1].isBool()) {
-            verbosity = request.params[1].get_bool() ? 1 : 0;
-        } else {
-            verbosity = request.params[1].getInt<int>();
-        }
-    }
+    int verbosity{ParseVerbosity(request.params[1], /*default_verbosity=*/1)};
 
     const CBlockIndex* pblockindex;
     const CBlockIndex* tip;
diff --git a/src/rpc/client.cpp b/src/rpc/client.cpp
index 0112a261ce..601e4fa7bf 100644
--- a/src/rpc/client.cpp
+++ b/src/rpc/client.cpp
@@ -254,6 +254,8 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "keypoolrefill", 0, "newsize" },
     { "getrawmempool", 0, "verbose" },
     { "getrawmempool", 1, "mempool_sequence" },
+    { "getorphantxs", 0, "verbosity" },
+    { "getorphantxs", 0, "verbose" },
     { "estimatesmartfee", 0, "conf_target" },
     { "estimaterawfee", 0, "conf_target" },
     { "estimaterawfee", 1, "threshold" },
diff --git a/src/rpc/mempool.cpp b/src/rpc/mempool.cpp
index d61898260b..27a00c5d91 100644
--- a/src/rpc/mempool.cpp
+++ b/src/rpc/mempool.cpp
@@ -8,8 +8,10 @@
 #include <node/mempool_persist.h>
 
 #include <chainparams.h>
+#include <consensus/validation.h>
 #include <core_io.h>
 #include <kernel/mempool_entry.h>
+#include <net_processing.h>
 #include <node/mempool_persist_args.h>
 #include <node/types.h>
 #include <policy/rbf.h>
@@ -24,6 +26,7 @@
 #include <util/moneystr.h>
 #include <util/strencodings.h>
 #include <util/time.h>
+#include <util/vector.h>
 
 #include <utility>
 
@@ -812,6 +815,104 @@ static RPCHelpMan savemempool()
     };
 }
 
+static std::vector<RPCResult> OrphanDescription()
+{
+    return {
+        RPCResult{RPCResult::Type::STR_HEX, "txid", "The transaction hash in hex"},
+        RPCResult{RPCResult::Type::STR_HEX, "wtxid", "The transaction witness hash in hex"},
+        RPCResult{RPCResult::Type::NUM, "bytes", "The serialized transaction size in bytes"},
+        RPCResult{RPCResult::Type::NUM, "vsize", "The virtual transaction size as defined in BIP 141. This is different from actual serialized size for witness transactions as witness data is discounted."},
+        RPCResult{RPCResult::Type::NUM, "weight", "The transaction weight as defined in BIP 141."},
+        RPCResult{RPCResult::Type::NUM_TIME, "expiration", "The orphan expiration time expressed in " + UNIX_EPOCH_TIME},
+        RPCResult{RPCResult::Type::ARR, "from", "",
+        {
+            RPCResult{RPCResult::Type::NUM, "peer_id", "Peer ID"},
+        }},
+    };
+}
+
+static UniValue OrphanToJSON(const TxOrphanage::OrphanTxBase& orphan)
+{
+    UniValue o(UniValue::VOBJ);
+    o.pushKV("txid", orphan.tx->GetHash().ToString());
+    o.pushKV("wtxid", orphan.tx->GetWitnessHash().ToString());
+    o.pushKV("bytes", orphan.tx->GetTotalSize());
+    o.pushKV("vsize", GetVirtualTransactionSize(*orphan.tx));
+    o.pushKV("weight", GetTransactionWeight(*orphan.tx));
+    o.pushKV("expiration", int64_t{TicksSinceEpoch<std::chrono::seconds>(orphan.nTimeExpire)});
+    UniValue from(UniValue::VARR);
+    from.push_back(orphan.fromPeer); // only one fromPeer for now
+    o.pushKV("from", from);
+    return o;
+}
+
+static RPCHelpMan getorphantxs()
+{
+    return RPCHelpMan{"getorphantxs",
+        "\nShows transactions in the tx orphanage.\n"
+        "\nEXPERIMENTAL warning: this call may be changed in future releases.\n",
+        {
+            {"verbosity|verbose", RPCArg::Type::NUM, RPCArg::Default{0}, "0 for an array of txids (may contain duplicates), 1 for an array of objects with tx details, and 2 for details from (1) and tx hex",
+             RPCArgOptions{.skip_type_check = true}},
+        },
+        {
+            RPCResult{"for verbose = 0",
+                RPCResult::Type::ARR, "", "",
+                {
+                    {RPCResult::Type::STR_HEX, "txid", "The transaction hash in hex"},
+                }},
+            RPCResult{"for verbose = 1",
+                RPCResult::Type::ARR, "", "",
+                {
+                    {RPCResult::Type::OBJ, "", "", OrphanDescription()},
+                }},
+            RPCResult{"for verbose = 2",
+                RPCResult::Type::ARR, "", "",
+                {
+                    {RPCResult::Type::OBJ, "", "",
+                        Cat<std::vector<RPCResult>>(
+                            OrphanDescription(),
+                            {{RPCResult::Type::STR_HEX, "hex", "The serialized, hex-encoded transaction data"}}
+                        )
+                    },
+                }},
+        },
+        RPCExamples{
+            HelpExampleCli("getorphantxs", "2")
+            + HelpExampleRpc("getorphantxs", "2")
+        },
+        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
+        {
+            const NodeContext& node = EnsureAnyNodeContext(request.context);
+            PeerManager& peerman = EnsurePeerman(node);
+            std::vector<TxOrphanage::OrphanTxBase> orphanage = peerman.GetOrphanTransactions();
+
+            int verbosity{ParseVerbosity(request.params[0], /*default_verbosity=*/0)};
+
+            UniValue ret(UniValue::VARR);
+
+            if (verbosity <= 0) {
+                for (auto const& orphan : orphanage) {
+                    ret.push_back(orphan.tx->GetHash().ToString());
+                }
+            } else if (verbosity == 1) {
+                for (auto const& orphan : orphanage) {
+                    ret.push_back(OrphanToJSON(orphan));
+                }
+            } else {
+                // >= 2
+                for (auto const& orphan : orphanage) {
+                    UniValue o{OrphanToJSON(orphan)};
+                    o.pushKV("hex", EncodeHexTx(*orphan.tx));
+                    ret.push_back(o);
+                }
+            }
+
+            return ret;
+        },
+    };
+}
+
 static RPCHelpMan submitpackage()
 {
     return RPCHelpMan{"submitpackage",
@@ -1027,6 +1128,7 @@ void RegisterMempoolRPCCommands(CRPCTable& t)
         {"blockchain", &getrawmempool},
         {"blockchain", &importmempool},
         {"blockchain", &savemempool},
+        {"hidden", &getorphantxs},
         {"rawtransactions", &submitpackage},
     };
     for (const auto& c : commands) {
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index bb072370ce..65e6e40b0d 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -338,15 +338,7 @@ static RPCHelpMan getrawtransaction()
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "The genesis block coinbase is not considered an ordinary transaction and cannot be retrieved");
     }
 
-    // Accept either a bool (true) or a num (>=0) to indicate verbosity.
-    int verbosity{0};
-    if (!request.params[1].isNull()) {
-        if (request.params[1].isBool()) {
-            verbosity = request.params[1].get_bool();
-        } else {
-            verbosity = request.params[1].getInt<int>();
-        }
-    }
+    int verbosity{ParseVerbosity(request.params[1], /*default_verbosity=*/0)};
 
     if (!request.params[2].isNull()) {
         LOCK(cs_main);
diff --git a/src/rpc/util.cpp b/src/rpc/util.cpp
index 678bac7a18..7757c258fd 100644
--- a/src/rpc/util.cpp
+++ b/src/rpc/util.cpp
@@ -81,6 +81,18 @@ void RPCTypeCheckObj(const UniValue& o,
     }
 }
 
+int ParseVerbosity(const UniValue& arg, int default_verbosity)
+{
+    if (!arg.isNull()) {
+        if (arg.isBool()) {
+            return arg.get_bool(); // true = 1
+        } else {
+            return arg.getInt<int>();
+        }
+    }
+    return default_verbosity;
+}
+
 CAmount AmountFromValue(const UniValue& value, int decimals)
 {
     if (!value.isNum() && !value.isStr())
diff --git a/src/rpc/util.h b/src/rpc/util.h
index 23024376e0..b8e6759768 100644
--- a/src/rpc/util.h
+++ b/src/rpc/util.h
@@ -101,6 +101,15 @@ std::vector<unsigned char> ParseHexV(const UniValue& v, std::string_view name);
 std::vector<unsigned char> ParseHexO(const UniValue& o, std::string_view strKey);
 
 /**
+ * Parses verbosity from provided UniValue.
+ *
+ * @param[in] arg The verbosity argument as a bool (true) or int (0, 1, 2,...)
+ * @param[in] default_verbosity The value to return if verbosity argument is null
+ * @returns An integer describing the verbosity level (e.g. 0, 1, 2, etc.)
+ */
+int ParseVerbosity(const UniValue& arg, int default_verbosity);
+
+/**
  * Validate and return a CAmount from a UniValue number or string.
  *
  * @param[in] value     UniValue number or string to parse.
diff --git a/src/test/fuzz/rpc.cpp b/src/test/fuzz/rpc.cpp
index 9122617e46..4db37ab7b7 100644
--- a/src/test/fuzz/rpc.cpp
+++ b/src/test/fuzz/rpc.cpp
@@ -143,6 +143,7 @@ const std::vector<std::string> RPC_COMMANDS_SAFE_FOR_FUZZING{
     "getnetworkhashps",
     "getnetworkinfo",
     "getnodeaddresses",
+    "getorphantxs",
     "getpeerinfo",
     "getprioritisedtransactions",
     "getrawaddrman",
diff --git a/src/txorphanage.cpp b/src/txorphanage.cpp
index 35a215c88a..ba4ba6c3b6 100644
--- a/src/txorphanage.cpp
+++ b/src/txorphanage.cpp
@@ -33,7 +33,7 @@ bool TxOrphanage::AddTx(const CTransactionRef& tx, NodeId peer)
         return false;
     }
 
-    auto ret = m_orphans.emplace(wtxid, OrphanTx{tx, peer, Now<NodeSeconds>() + ORPHAN_TX_EXPIRE_TIME, m_orphan_list.size()});
+    auto ret = m_orphans.emplace(wtxid, OrphanTx{{tx, peer, Now<NodeSeconds>() + ORPHAN_TX_EXPIRE_TIME}, m_orphan_list.size()});
     assert(ret.second);
     m_orphan_list.push_back(ret.first);
     for (const CTxIn& txin : tx->vin) {
@@ -277,3 +277,13 @@ std::vector<std::pair<CTransactionRef, NodeId>> TxOrphanage::GetChildrenFromDiff
     }
     return children_found;
 }
+
+std::vector<TxOrphanage::OrphanTxBase> TxOrphanage::GetOrphanTransactions() const
+{
+    std::vector<OrphanTxBase> ret;
+    ret.reserve(m_orphans.size());
+    for (auto const& o : m_orphans) {
+        ret.push_back({o.second.tx, o.second.fromPeer, o.second.nTimeExpire});
+    }
+    return ret;
+}
diff --git a/src/txorphanage.h b/src/txorphanage.h
index 2c53d1d40f..5501d10922 100644
--- a/src/txorphanage.h
+++ b/src/txorphanage.h
@@ -72,11 +72,17 @@ public:
         return m_orphans.size();
     }
 
-protected:
-    struct OrphanTx {
+    /** Allows providing orphan information externally */
+    struct OrphanTxBase {
         CTransactionRef tx;
         NodeId fromPeer;
         NodeSeconds nTimeExpire;
+    };
+
+    std::vector<OrphanTxBase> GetOrphanTransactions() const;
+
+protected:
+    struct OrphanTx : public OrphanTxBase {
         size_t list_pos;
     };