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).

1 files changed, 13 insertions, 1 deletions

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