Switch ConnKey storage in Connecton class to a smart pointer.

The class previously kept a full copy, preventing virtualization.

There are 3 remaining uses of the existing Connection object constructor, all in
C++ unit tests. Since Connection isn't in the detail namespace we can't
immediately change its API, but we could deprecate the existing constructor at
this time.

src/Conn.cc

@@ -27,7 +27,7 @@ namespace zeek {
 uint64_t Connection::total_connections = 0;
 uint64_t Connection::current_connections = 0;
 
-Connection::Connection(const detail::ConnKey& k, double t, const ConnTuple* id, uint32_t flow, const Packet* pkt)
+Connection::Connection(const detail::ConnKeyPtr k, double t, const ConnTuple* id, uint32_t flow, const Packet* pkt)
     : Session(t, connection_timeout, connection_status_update, detail::connection_status_update_interval), key(k) {
     orig_addr = id->src_addr;
     resp_addr = id->dst_addr;
@@ -75,6 +75,9 @@ Connection::Connection(const detail::ConnKey& k, double t, const ConnTuple* id,
     encapsulation = pkt->encap;
 }
 
+Connection::Connection(const detail::ConnKey& k, double t, const ConnTuple* id, uint32_t flow, const Packet* pkt)
+    : Connection(std::make_shared<zeek::detail::ConnKey>(k), t, id, flow, pkt) {}
+
 Connection::~Connection() {
     if ( ! finished )
         reporter->InternalError("Done() not called before destruction of Connection");
@@ -89,6 +92,8 @@ Connection::~Connection() {
     --current_connections;
 }
 
+session::detail::Key Connection::SessionKey(bool copy) const { return key->SessionKey(); }
+
 void Connection::CheckEncapsulation(const std::shared_ptr<EncapsulationStack>& arg_encap) {
     if ( encapsulation && arg_encap ) {
         if ( *encapsulation != *arg_encap ) {

src/Conn.h

@@ -73,6 +73,7 @@ static inline int addr_port_canon_lt(const IPAddr& addr1, uint32_t p1, const IPA
 
 class Connection final : public session::Session {
 public:
+    Connection(const detail::ConnKeyPtr k, double t, const ConnTuple* id, uint32_t flow, const Packet* pkt);
     Connection(const detail::ConnKey& k, double t, const ConnTuple* id, uint32_t flow, const Packet* pkt);
     ~Connection() override;
 
@@ -110,10 +111,8 @@ public:
     // Keys are only considered valid for a connection when a
     // connection is in the session map. If it is removed, the key
     // should be marked invalid.
-    const detail::ConnKey& Key() const { return key; }
+    const detail::ConnKey& Key() const { return *key; }
-    session::detail::Key SessionKey(bool copy) const override {
+    session::detail::Key SessionKey(bool copy) const override;
-        return session::detail::Key{&key, sizeof(key), session::detail::Key::CONNECTION_KEY_TYPE, copy};
-    }
 
     const IPAddr& OrigAddr() const { return orig_addr; }
     const IPAddr& RespAddr() const { return resp_addr; }
@@ -139,7 +138,7 @@ public:
             return "unknown";
     }
 
-    uint8_t KeyProto() const { return key.transport; }
+    uint8_t KeyProto() const { return key->transport; }
 
     // Returns true if the packet reflects a reuse of this
     // connection (i.e., not a continuation but the beginning of
@@ -220,7 +219,7 @@ private:
     std::shared_ptr<EncapsulationStack> encapsulation; // tunnels
     uint8_t tunnel_changes = 0;
 
-    detail::ConnKey key;
+    detail::ConnKeyPtr key;
 
     unsigned int weird : 1;
     unsigned int finished : 1;

src/IPAddr.h

@@ -37,6 +37,7 @@ public:
     ConnKey(const IPAddr& src, const IPAddr& dst, uint16_t src_port, uint16_t dst_port, uint16_t proto, bool one_way);
     ConnKey(const ConnTuple& conn);
     ConnKey(Val* v);
+    virtual ~ConnKey() {};
 
     session::detail::Key SessionKey() const;
     virtual size_t PackedSize() const;