[Spice-devel] [PATCH migration 18/19] client: support semi-seamless migration between spice servers with different protocols.

[Yonit Halperin]

It can't actually happen right now, since switch-host migration scheme will take
place if the src/target server has protocol 1.
(cherry picked from commit 4b2bf4d88c253502003aa5e4b93a045742eec9b4 branch 0.8)

Signed-off-by: Yonit Halperin <yhalperi at redhat.com>
---
 client/red_channel.cpp |   20 ++++++++++++++++++++
 client/red_channel.h   |    2 ++
 client/red_client.cpp  |   21 ++++++++++++++++-----
 client/red_client.h    |    3 ++-
 4 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/client/red_channel.cpp b/client/red_channel.cpp
index d85265b..e8c058c 100644
--- a/client/red_channel.cpp
+++ b/client/red_channel.cpp
@@ -298,6 +298,20 @@ bool RedChannelBase::test_capability(uint32_t cap)
     return test_capability(_remote_caps, cap);
 }
 
+void RedChannelBase::swap(RedChannelBase* other)
+{
+    int tmp_ver;
+
+    RedPeer::swap(other);
+    tmp_ver = _remote_major;
+    _remote_major = other->_remote_major;
+    other->_remote_major = tmp_ver;
+
+    tmp_ver = _remote_minor;
+    _remote_minor = other->_remote_minor;
+    other->_remote_minor = tmp_ver;
+}
+
 SendTrigger::SendTrigger(RedChannel& channel)
     : _channel (channel)
 {
@@ -493,6 +507,12 @@ void RedChannel::do_migration_disconnect_src()
 void RedChannel::do_migration_connect_target()
 {
     LOG_INFO("");
+    ASSERT(get_client().get_protocol() != 0);
+    if (get_client().get_protocol() == 1) {
+        _marshallers = spice_message_marshallers_get1();
+    } else {
+        _marshallers = spice_message_marshallers_get();
+    }
     _loop.add_socket(*this);
     _socket_in_loop = true;
     on_connect_mig_target();
diff --git a/client/red_channel.h b/client/red_channel.h
index ba78acc..ee5b185 100644
--- a/client/red_channel.h
+++ b/client/red_channel.h
@@ -66,6 +66,8 @@ public:
      uint32_t get_peer_major() { return _remote_major;}
      uint32_t get_peer_minor() { return _remote_minor;}
 
+     virtual void swap(RedChannelBase* other);
+
 protected:
     void set_common_capability(uint32_t cap);
     void set_capability(uint32_t cap);
diff --git a/client/red_client.cpp b/client/red_client.cpp
index 4fc442f..2f6c6ce 100644
--- a/client/red_client.cpp
+++ b/client/red_client.cpp
@@ -136,6 +136,7 @@ Migrate::Migrate(RedClient& client)
     , _connected (false)
     , _thread (NULL)
     , _pending_con (0)
+    , _protocol (0)
 {
 }
 
@@ -192,7 +193,7 @@ void Migrate::swap_peer(RedChannelBase& other)
                 curr->set_valid(false);
                 if (!--_pending_con) {
                     lock.unlock();
-                    _client.set_target(_host.c_str(), _port, _sport);
+                    _client.set_target(_host.c_str(), _port, _sport, _protocol);
                     abort();
                 }
                 return;
@@ -215,6 +216,13 @@ void Migrate::connect_one(MigChannel& channel, const RedPeer::ConnectionOptions&
     channel.connect(options, connection_id, _host.c_str(), _password);
     ++_pending_con;
     channel.set_valid(true);
+    if (_protocol == 0) {
+        if (channel.get_peer_major() == 1) {
+            _protocol = 1;
+        } else {
+            _protocol = 2;
+        }
+    }
 }
 
 void Migrate::run()
@@ -235,7 +243,7 @@ void Migrate::run()
         for (++iter; iter != _channels.end(); ++iter) {
             conn_type = _client.get_connection_options((*iter)->get_type());
             con_opt = RedPeer::ConnectionOptions(conn_type, _port, _sport,
-						 _client.get_protocol(),
+                                                 _protocol,
                                                  _auth_options, _con_ciphers);
             connect_one(**iter, con_opt, connection_id);
         }
@@ -445,11 +453,16 @@ RedClient::~RedClient()
     delete[] _agent_caps;
 }
 
-void RedClient::set_target(const std::string& host, int port, int sport)
+void RedClient::set_target(const std::string& host, int port, int sport, int protocol)
 {
+    if (protocol != get_protocol()) {
+        LOG_INFO("old protocol %d, new protocol %d", get_protocol(), protocol);
+    }
+
     _port = port;
     _sport = sport;
     _host.assign(host);
+    set_protocol(protocol);
 }
 
 void RedClient::push_event(Event* event)
@@ -684,10 +697,8 @@ void RedClient::on_channel_disconnect_mig_src_completed(RedChannel& channel)
         _pixmap_cache.clear();
         _glz_window.clear();
         memset(_sync_info, 0, sizeof(_sync_info));
-
         LOG_INFO("calling main to connect and wait for handle_init to tell all the other channels to connect");
         RedChannel::connect_migration_target();
-
         AutoRef<MigrateEndEvent> mig_end_event(new MigrateEndEvent());
         get_process_loop().push_event(*mig_end_event);
     }
diff --git a/client/red_client.h b/client/red_client.h
index 20d5ffb..f4cd46b 100644
--- a/client/red_client.h
+++ b/client/red_client.h
@@ -82,6 +82,7 @@ private:
     Mutex _lock;
     Condition _cond;
     int _pending_con;
+    int _protocol;
 };
 
 class ChannelFactory {
@@ -238,7 +239,7 @@ public:
     void activate_interval_timer(Timer* timer, unsigned int millisec);
     void deactivate_interval_timer(Timer* timer);
 
-    void set_target(const std::string& host, int port, int sport);
+    void set_target(const std::string& host, int port, int sport, int protocol = 0);
     void set_password(const std::string& password) { _password = password;}
     void set_auto_display_res(bool auto_display_res) { _auto_display_res = auto_display_res;}
     void set_display_setting(DisplaySetting& setting) { _display_setting = setting;}
-- 
1.7.6.4