1 files changed, 59 insertions, 2 deletions

diff --git a/src/netaddress.h b/src/netaddress.h
index f2daad7fb6..0365907d44 100644
--- a/src/netaddress.h
+++ b/src/netaddress.h
@@ -16,21 +16,50 @@
 #include <string>
 #include <vector>
 
+/**
+ * A network type.
+ * @note An address may belong to more than one network, for example `10.0.0.1`
+ * belongs to both `NET_UNROUTABLE` and `NET_IPV4`.
+ * Keep these sequential starting from 0 and `NET_MAX` as the last entry.
+ * We have loops like `for (int i = 0; i < NET_MAX; i++)` that expect to iterate
+ * over all enum values and also `GetExtNetwork()` "extends" this enum by
+ * introducing standalone constants starting from `NET_MAX`.
+ */
 enum Network
 {
+    /// Addresses from these networks are not publicly routable on the global Internet.
     NET_UNROUTABLE = 0,
+
+    /// IPv4
     NET_IPV4,
+
+    /// IPv6
     NET_IPV6,
+
+    /// TORv2
     NET_ONION,
+
+    /// A set of dummy addresses that map a name to an IPv6 address. These
+    /// addresses belong to RFC4193's fc00::/7 subnet (unique-local addresses).
+    /// We use them to map a string or FQDN to an IPv6 address in CAddrMan to
+    /// keep track of which DNS seeds were used.
     NET_INTERNAL,
 
+    /// Dummy value to indicate the number of NET_* constants.
     NET_MAX,
 };
 
-/** IP address (IPv6, or IPv4 using mapped IPv6 range (::FFFF:0:0/96)) */
+/**
+ * Network address.
+ */
 class CNetAddr
 {
     protected:
+        /**
+         * Network to which this address belongs.
+         */
+        Network m_net{NET_IPV6};
+
         unsigned char ip[16]; // in network byte order
         uint32_t scopeId{0}; // for scoped/link-local ipv6 addresses
 
@@ -40,6 +69,14 @@ class CNetAddr
         void SetIP(const CNetAddr& ip);
 
         /**
+         * Set from a legacy IPv6 address.
+         * Legacy IPv6 address may be a normal IPv6 address, or another address
+         * (e.g. IPv4) disguised as IPv6. This encoding is used in the legacy
+         * `addr` encoding.
+         */
+        void SetLegacyIPv6(const uint8_t ipv6[16]);
+
+        /**
          * Set raw IPv4 or IPv6 address (in network byte order)
          * @note Only NET_IPV4 and NET_IPV6 are allowed for network.
          */
@@ -100,7 +137,27 @@ class CNetAddr
         friend bool operator!=(const CNetAddr& a, const CNetAddr& b) { return !(a == b); }
         friend bool operator<(const CNetAddr& a, const CNetAddr& b);
 
-        SERIALIZE_METHODS(CNetAddr, obj) { READWRITE(obj.ip); }
+        /**
+         * Serialize to a stream.
+         */
+        template <typename Stream>
+        void Serialize(Stream& s) const
+        {
+            s << ip;
+        }
+
+        /**
+         * Unserialize from a stream.
+         */
+        template <typename Stream>
+        void Unserialize(Stream& s)
+        {
+            unsigned char ip_temp[sizeof(ip)];
+            s >> ip_temp;
+            // Use SetLegacyIPv6() so that m_net is set correctly. For example
+            // ::FFFF:0102:0304 should be set as m_net=NET_IPV4 (1.2.3.4).
+            SetLegacyIPv6(ip_temp);
+        }
 
         friend class CSubNet;
 };