net: recognize TORv3/I2P/CJDNS networks

Recognizing addresses from those networks allows us to accept and gossip
them, even though we don't know how to connect to them (yet).

Co-authored-by: eriknylund <erik@daychanged.com>

1 files changed, 32 insertions, 5 deletions

diff --git a/src/netaddress.h b/src/netaddress.h
index 08857ae729..59f1b87ad3 100644
--- a/src/netaddress.h
+++ b/src/netaddress.h
@@ -51,9 +51,15 @@ enum Network
     /// IPv6
     NET_IPV6,
 
-    /// TORv2
+    /// TOR (v2 or v3)
     NET_ONION,
 
+    /// I2P
+    NET_I2P,
+
+    /// CJDNS
+    NET_CJDNS,
+
     /// A set of addresses that represent the hash of a string or FQDN. We use
     /// them in CAddrMan to keep track of which DNS seeds were used.
     NET_INTERNAL,
@@ -94,6 +100,16 @@ static constexpr size_t ADDR_IPV6_SIZE = 16;
 /// Size of TORv2 address (in bytes).
 static constexpr size_t ADDR_TORV2_SIZE = 10;
 
+/// Size of TORv3 address (in bytes). This is the length of just the address
+/// as used in BIP155, without the checksum and the version byte.
+static constexpr size_t ADDR_TORV3_SIZE = 32;
+
+/// Size of I2P address (in bytes).
+static constexpr size_t ADDR_I2P_SIZE = 32;
+
+/// Size of CJDNS address (in bytes).
+static constexpr size_t ADDR_CJDNS_SIZE = 16;
+
 /// Size of "internal" (NET_INTERNAL) address (in bytes).
 static constexpr size_t ADDR_INTERNAL_SIZE = 10;
 
@@ -151,6 +167,8 @@ class CNetAddr
         bool IsRFC6145() const; // IPv6 IPv4-translated address (::FFFF:0:0:0/96) (actually defined in RFC2765)
         bool IsHeNet() const;   // IPv6 Hurricane Electric - https://he.net (2001:0470::/36)
         bool IsTor() const;
+        bool IsI2P() const;
+        bool IsCJDNS() const;
         bool IsLocal() const;
         bool IsRoutable() const;
         bool IsInternal() const;
@@ -219,6 +237,9 @@ class CNetAddr
             IPV4 = 1,
             IPV6 = 2,
             TORV2 = 3,
+            TORV3 = 4,
+            I2P = 5,
+            CJDNS = 6,
         };
 
         /**
@@ -245,13 +266,12 @@ class CNetAddr
          * @retval true the network was recognized, is valid and `m_net` was set
          * @retval false not recognised (from future?) and should be silently ignored
          * @throws std::ios_base::failure if the network is one of the BIP155 founding
-         * networks recognized by this software (id 1..3) and has wrong address size.
+         * networks (id 1..6) with wrong address size.
          */
         bool SetNetFromBIP155Network(uint8_t possible_bip155_net, size_t address_size);
 
         /**
          * Serialize in pre-ADDRv2/BIP155 format to an array.
-         * Some addresses (e.g. TORv3) cannot be serialized in pre-BIP155 format.
          */
         void SerializeV1Array(uint8_t (&arr)[V1_SERIALIZATION_SIZE]) const
         {
@@ -269,6 +289,9 @@ class CNetAddr
                 memcpy(arr + prefix_size, m_addr.data(), m_addr.size());
                 return;
             case NET_ONION:
+                if (m_addr.size() == ADDR_TORV3_SIZE) {
+                    break;
+                }
                 prefix_size = sizeof(TORV2_IN_IPV6_PREFIX);
                 assert(prefix_size + m_addr.size() == sizeof(arr));
                 memcpy(arr, TORV2_IN_IPV6_PREFIX.data(), prefix_size);
@@ -280,17 +303,21 @@ class CNetAddr
                 memcpy(arr, INTERNAL_IN_IPV6_PREFIX.data(), prefix_size);
                 memcpy(arr + prefix_size, m_addr.data(), m_addr.size());
                 return;
+            case NET_I2P:
+                break;
+            case NET_CJDNS:
+                break;
             case NET_UNROUTABLE:
             case NET_MAX:
                 assert(false);
             } // no default case, so the compiler can warn about missing cases
 
-            assert(false);
+            // Serialize TORv3, I2P and CJDNS as all-zeros.
+            memset(arr, 0x0, V1_SERIALIZATION_SIZE);
         }
 
         /**
          * Serialize in pre-ADDRv2/BIP155 format to a stream.
-         * Some addresses (e.g. TORv3) cannot be serialized in pre-BIP155 format.
          */
         template <typename Stream>
         void SerializeV1Stream(Stream& s) const