rpc: getrawaddrman for addrman entries

Exposing address manager table entries in a hidden RPC allows to introspect
addrman tables in tests and during development.

As response JSON object the following FORMAT1 is choosen:
{
  "table": {
    "<bucket>/<position>": { "address": "..", "port": .., ... },
    "<bucket>/<position>": { "address": "..", "port": .., ... },
    "<bucket>/<position>": { "address": "..", "port": .., ... },
    ...
  }
}

An alternative would be FORMAT2
{
  "table": {
    "bucket": {
      "position": { "address": "..", "port": .., ... },
      "position": { "address": "..", "port": .., ... },
      ..
    },
    "bucket": {
      "position": { "address": "..", "port": .., ... },
      ..
    },
  }
}

FORMAT1 and FORMAT2 have different encodings for the location of the
address in the address manager. While FORMAT2 might be easier to process
for downstream tools, it also mimics internal addrman mappings, which
might change at some point. Users not interested in the address location
can ignore the location key. They don't have to adapt to a new RPC
response format, when the internal addrman layout changes. Additionally,
FORMAT1 is also slightly easier to to iterate in downstream tools. The
RPC response-building implemenation complexcity is lower with FORMAT1
as we can more easily build a "<bucket>/<position>" key than a multiple
"bucket" objects with multiple "position" objects (FORMAT2).

5 files changed, 127 insertions, 1 deletions

diff --git a/src/addrman.cpp b/src/addrman.cpp
index 212baab9d4..6ce9c81c63 100644
--- a/src/addrman.cpp
+++ b/src/addrman.cpp
@@ -838,6 +838,30 @@ std::vector<CAddress> AddrManImpl::GetAddr_(size_t max_addresses, size_t max_pct
     return addresses;
 }
 
+std::vector<std::pair<AddrInfo, AddressPosition>> AddrManImpl::GetEntries_(bool from_tried) const
+{
+    AssertLockHeld(cs);
+
+    const int bucket_count = from_tried ? ADDRMAN_TRIED_BUCKET_COUNT : ADDRMAN_NEW_BUCKET_COUNT;
+    std::vector<std::pair<AddrInfo, AddressPosition>> infos;
+    for (int bucket = 0; bucket < bucket_count; ++bucket) {
+        for (int position = 0; position < ADDRMAN_BUCKET_SIZE; ++position) {
+            int id = GetEntry(from_tried, bucket, position);
+            if (id >= 0) {
+                AddrInfo info = mapInfo.at(id);
+                AddressPosition location = AddressPosition(
+                    from_tried,
+                    /*multiplicity_in=*/from_tried ? 1 : info.nRefCount,
+                    bucket,
+                    position);
+                infos.push_back(std::make_pair(info, location));
+            }
+        }
+    }
+
+    return infos;
+}
+
 void AddrManImpl::Connected_(const CService& addr, NodeSeconds time)
 {
     AssertLockHeld(cs);
@@ -1199,6 +1223,15 @@ std::vector<CAddress> AddrManImpl::GetAddr(size_t max_addresses, size_t max_pct,
     return addresses;
 }
 
+std::vector<std::pair<AddrInfo, AddressPosition>> AddrManImpl::GetEntries(bool from_tried) const
+{
+    LOCK(cs);
+    Check();
+    auto addrInfos = GetEntries_(from_tried);
+    Check();
+    return addrInfos;
+}
+
 void AddrManImpl::Connected(const CService& addr, NodeSeconds time)
 {
     LOCK(cs);
@@ -1289,6 +1322,11 @@ std::vector<CAddress> AddrMan::GetAddr(size_t max_addresses, size_t max_pct, std
     return m_impl->GetAddr(max_addresses, max_pct, network);
 }
 
+std::vector<std::pair<AddrInfo, AddressPosition>> AddrMan::GetEntries(bool use_tried) const
+{
+    return m_impl->GetEntries(use_tried);
+}
+
 void AddrMan::Connected(const CService& addr, NodeSeconds time)
 {
     m_impl->Connected(addr, time);
diff --git a/src/addrman.h b/src/addrman.h
index f41687dcff..4d44c943ac 100644
--- a/src/addrman.h
+++ b/src/addrman.h
@@ -25,11 +25,12 @@ public:
 };
 
 class AddrManImpl;
+class AddrInfo;
 
 /** Default for -checkaddrman */
 static constexpr int32_t DEFAULT_ADDRMAN_CONSISTENCY_CHECKS{0};
 
-/** Test-only struct, capturing info about an address in AddrMan */
+/** Location information for an address in AddrMan */
 struct AddressPosition {
     // Whether the address is in the new or tried table
     const bool tried;
@@ -168,6 +169,17 @@ public:
      */
     std::vector<CAddress> GetAddr(size_t max_addresses, size_t max_pct, std::optional<Network> network) const;
 
+    /**
+     * Returns an information-location pair for all addresses in the selected addrman table.
+     * If an address appears multiple times in the new table, an information-location pair
+     * is returned for each occurence. Addresses only ever appear once in the tried table.
+     *
+     * @param[in] from_tried     Selects which table to return entries from.
+     *
+     * @return                   A vector consisting of pairs of AddrInfo and AddressPosition.
+     */
+    std::vector<std::pair<AddrInfo, AddressPosition>> GetEntries(bool from_tried) const;
+
     /** We have successfully connected to this peer. Calling this function
      *  updates the CAddress's nTime, which is used in our IsTerrible()
      *  decisions and gossiped to peers. Callers should be careful that updating
diff --git a/src/addrman_impl.h b/src/addrman_impl.h
index 1cfaca04a3..512f085a21 100644
--- a/src/addrman_impl.h
+++ b/src/addrman_impl.h
@@ -132,6 +132,9 @@ public:
     std::vector<CAddress> GetAddr(size_t max_addresses, size_t max_pct, std::optional<Network> network) const
         EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
+    std::vector<std::pair<AddrInfo, AddressPosition>> GetEntries(bool from_tried) const
+        EXCLUSIVE_LOCKS_REQUIRED(!cs);
+
     void Connected(const CService& addr, NodeSeconds time)
         EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
@@ -260,6 +263,8 @@ private:
 
     std::vector<CAddress> GetAddr_(size_t max_addresses, size_t max_pct, std::optional<Network> network) const EXCLUSIVE_LOCKS_REQUIRED(cs);
 
+    std::vector<std::pair<AddrInfo, AddressPosition>> GetEntries_(bool from_tried) const EXCLUSIVE_LOCKS_REQUIRED(cs);
+
     void Connected_(const CService& addr, NodeSeconds time) EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     void SetServices_(const CService& addr, ServiceFlags nServices) EXCLUSIVE_LOCKS_REQUIRED(cs);
diff --git a/src/rpc/net.cpp b/src/rpc/net.cpp
index 6af62641bd..8ebc6a73cf 100644
--- a/src/rpc/net.cpp
+++ b/src/rpc/net.cpp
@@ -5,6 +5,7 @@
 #include <rpc/server.h>
 
 #include <addrman.h>
+#include <addrman_impl.h>
 #include <banman.h>
 #include <chainparams.h>
 #include <clientversion.h>
@@ -1063,6 +1064,74 @@ static RPCHelpMan getaddrmaninfo()
     };
 }
 
+UniValue AddrmanEntryToJSON(const AddrInfo& info)
+{
+    UniValue ret(UniValue::VOBJ);
+    ret.pushKV("address", info.ToStringAddr());
+    ret.pushKV("port", info.GetPort());
+    ret.pushKV("services", (uint64_t)info.nServices);
+    ret.pushKV("time", int64_t{TicksSinceEpoch<std::chrono::seconds>(info.nTime)});
+    ret.pushKV("network", GetNetworkName(info.GetNetClass()));
+    ret.pushKV("source", info.source.ToStringAddr());
+    ret.pushKV("source_network", GetNetworkName(info.source.GetNetClass()));
+    return ret;
+}
+
+UniValue AddrmanTableToJSON(const std::vector<std::pair<AddrInfo, AddressPosition>>& tableInfos)
+{
+    UniValue table(UniValue::VOBJ);
+    for (const auto& e : tableInfos) {
+        AddrInfo info = e.first;
+        AddressPosition location = e.second;
+        std::ostringstream key;
+        key << location.bucket << "/" << location.position;
+        // Address manager tables have unique entries so there is no advantage
+        // in using UniValue::pushKV, which checks if the key already exists
+        // in O(N). UniValue::pushKVEnd is used instead which currently is O(1).
+        table.pushKVEnd(key.str(), AddrmanEntryToJSON(info));
+    }
+    return table;
+}
+
+static RPCHelpMan getrawaddrman()
+{
+    return RPCHelpMan{"getrawaddrman",
+        "EXPERIMENTAL warning: this call may be changed in future releases.\n"
+        "\nReturns information on all address manager entries for the new and tried tables.\n",
+        {},
+        RPCResult{
+            RPCResult::Type::OBJ_DYN, "", "", {
+                {RPCResult::Type::OBJ_DYN, "table", "buckets with addresses in the address manager table ( new, tried )", {
+                    {RPCResult::Type::OBJ, "bucket/position", "the location in the address manager table (<bucket>/<position>)", {
+                        {RPCResult::Type::STR, "address", "The address of the node"},
+                        {RPCResult::Type::NUM, "port", "The port number of the node"},
+                        {RPCResult::Type::STR, "network", "The network (" + Join(GetNetworkNames(), ", ") + ") of the address"},
+                        {RPCResult::Type::NUM, "services", "The services offered by the node"},
+                        {RPCResult::Type::NUM_TIME, "time", "The " + UNIX_EPOCH_TIME + " when the node was last seen"},
+                        {RPCResult::Type::STR, "source", "The address that relayed the address to us"},
+                        {RPCResult::Type::STR, "source_network", "The network (" + Join(GetNetworkNames(), ", ") + ") of the source address"},
+                    }}
+                }}
+            }
+        },
+        RPCExamples{
+            HelpExampleCli("getrawaddrman", "")
+            + HelpExampleRpc("getrawaddrman", "")
+        },
+        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue {
+            NodeContext& node = EnsureAnyNodeContext(request.context);
+            if (!node.addrman) {
+                throw JSONRPCError(RPC_CLIENT_P2P_DISABLED, "Error: Address manager functionality missing or disabled");
+            }
+
+            UniValue ret(UniValue::VOBJ);
+            ret.pushKV("new", AddrmanTableToJSON(node.addrman->GetEntries(false)));
+            ret.pushKV("tried", AddrmanTableToJSON(node.addrman->GetEntries(true)));
+            return ret;
+        },
+    };
+}
+
 void RegisterNetRPCCommands(CRPCTable& t)
 {
     static const CRPCCommand commands[]{
@@ -1083,6 +1152,7 @@ void RegisterNetRPCCommands(CRPCTable& t)
         {"hidden", &addpeeraddress},
         {"hidden", &sendmsgtopeer},
         {"hidden", &getaddrmaninfo},
+        {"hidden", &getrawaddrman},
     };
     for (const auto& c : commands) {
         t.appendCommand(c.name, &c);
diff --git a/src/test/fuzz/rpc.cpp b/src/test/fuzz/rpc.cpp
index 7e9a18e1d0..cffda751df 100644
--- a/src/test/fuzz/rpc.cpp
+++ b/src/test/fuzz/rpc.cpp
@@ -140,6 +140,7 @@ const std::vector<std::string> RPC_COMMANDS_SAFE_FOR_FUZZING{
     "getnodeaddresses",
     "getpeerinfo",
     "getprioritisedtransactions",
+    "getrawaddrman",
     "getrawmempool",
     "getrawtransaction",
     "getrpcinfo",