dev-libs/glib: fix CVE-2020-6750 (proxy settings sometimes ignored)

Package-Manager: Portage-2.3.84, Repoman-2.3.20
Signed-off-by: Mart Raudsepp <leio@gentoo.org>

1 files changed, 763 insertions, 0 deletions

diff --git a/dev-libs/glib/files/CVE-2020-6750.patch b/dev-libs/glib/files/CVE-2020-6750.patch
new file mode 100644
index 000000000000..fe39914f9204
--- /dev/null
+++ b/dev-libs/glib/files/CVE-2020-6750.patch
@@ -0,0 +1,763 @@
+From cc3cf6b8b2ad12d54f3474113f0ccfa7dcf66b7b Mon Sep 17 00:00:00 2001
+From: Michael Catanzaro <mcatanzaro@gnome.org>
+Date: Sat, 4 Jan 2020 20:46:25 -0600
+Subject: [PATCH] gsocketclient: run timeout source on the task's main context
+
+This shouldn't make any difference, because this code should only ever
+be running in the main context that was thread-default at the time the
+task was created, so it should already match the task's context. But
+let's make sure, just in case.
+---
+ gio/gsocketclient.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/gio/gsocketclient.c b/gio/gsocketclient.c
+index 6adeee299..81721795b 100644
+--- a/gio/gsocketclient.c
++++ b/gio/gsocketclient.c
+@@ -1794,7 +1794,7 @@ g_socket_client_enumerator_callback (GObject      *object,
+   attempt->connection = (GIOStream *)g_socket_connection_factory_create_connection (socket);
+   attempt->timeout_source = g_timeout_source_new (HAPPY_EYEBALLS_CONNECTION_ATTEMPT_TIMEOUT_MS);
+   g_source_set_callback (attempt->timeout_source, on_connection_attempt_timeout, attempt, NULL);
+-  g_source_attach (attempt->timeout_source, g_main_context_get_thread_default ());
++  g_source_attach (attempt->timeout_source, g_task_get_context (data->task));
+   data->connection_attempts = g_slist_append (data->connection_attempts, attempt);
+ 
+   if (g_task_get_cancellable (data->task))
+-- 
+2.24.1
+
+From d4fcf91460696b09bb2b55c352a023f6dd71c7fe Mon Sep 17 00:00:00 2001
+From: Patrick Griffis <tingping@tingping.se>
+Date: Thu, 23 Jan 2020 19:58:41 -0800
+Subject: [PATCH] Refactor g_socket_client_connect_async()
+
+This is a fairly large refactoring. The highlights are:
+
+- Removing in-progress connections/addresses from GSocketClientAsyncConnectData:
+
+  This caused issues where multiple ConnectionAttempt's would step over eachother
+  and modify shared state causing bugs like accidentally bypassing a set proxy.
+
+  Fixes #1871
+  Fixes #1989
+  Fixes #1902
+
+- Cancelling address enumeration on error/completion
+
+- Queuing successful TCP connections and doing application layer work serially:
+
+  This is more in the spirit of Happy Eyeballs but it also greatly simplifies
+  the flow of connection handling so fewer tasks are happening in parallel
+  when they don't need to be.
+
+  The behavior also should more closely match that of g_socket_client_connect().
+
+- Better track the state of address enumeration:
+
+  Previously we were over eager to treat enumeration finishing as an error.
+
+  Fixes #1872
+  See also #1982
+
+- Add more detailed documentation and logging.
+
+Closes #1995
+---
+ gio/gsocketclient.c | 459 ++++++++++++++++++++++++++++----------------
+ 1 file changed, 296 insertions(+), 163 deletions(-)
+
+diff --git a/gio/gsocketclient.c b/gio/gsocketclient.c
+index 81721795b..c9943309c 100644
+--- a/gio/gsocketclient.c
++++ b/gio/gsocketclient.c
+@@ -1337,13 +1337,15 @@ typedef struct
+ 
+   GSocketConnectable *connectable;
+   GSocketAddressEnumerator *enumerator;
+-  GProxyAddress *proxy_addr;
+-  GSocket *socket;
+-  GIOStream *connection;
++  GCancellable *enumeration_cancellable;
+ 
+   GSList *connection_attempts;
++  GSList *successful_connections;
+   GError *last_error;
+ 
++  gboolean enumerated_at_least_once;
++  gboolean enumeration_completed;
++  gboolean connection_in_progress;
+   gboolean completed;
+ } GSocketClientAsyncConnectData;
+ 
+@@ -1355,10 +1357,9 @@ g_socket_client_async_connect_data_free (GSocketClientAsyncConnectData *data)
+   data->task = NULL;
+   g_clear_object (&data->connectable);
+   g_clear_object (&data->enumerator);
+-  g_clear_object (&data->proxy_addr);
+-  g_clear_object (&data->socket);
+-  g_clear_object (&data->connection);
++  g_clear_object (&data->enumeration_cancellable);
+   g_slist_free_full (data->connection_attempts, connection_attempt_unref);
++  g_slist_free_full (data->successful_connections, connection_attempt_unref);
+ 
+   g_clear_error (&data->last_error);
+ 
+@@ -1370,6 +1371,7 @@ typedef struct
+   GSocketAddress *address;
+   GSocket *socket;
+   GIOStream *connection;
++  GProxyAddress *proxy_addr;
+   GSocketClientAsyncConnectData *data; /* unowned */
+   GSource *timeout_source;
+   GCancellable *cancellable;
+@@ -1401,6 +1403,7 @@ connection_attempt_unref (gpointer pointer)
+       g_clear_object (&attempt->socket);
+       g_clear_object (&attempt->connection);
+       g_clear_object (&attempt->cancellable);
++      g_clear_object (&attempt->proxy_addr);
+       if (attempt->timeout_source)
+         {
+           g_source_destroy (attempt->timeout_source);
+@@ -1418,37 +1421,59 @@ connection_attempt_remove (ConnectionAttempt *attempt)
+ }
+ 
+ static void
+-g_socket_client_async_connect_complete (GSocketClientAsyncConnectData *data)
++cancel_all_attempts (GSocketClientAsyncConnectData *data)
+ {
+-  g_assert (data->connection);
++  GSList *l;
+ 
+-  if (!G_IS_SOCKET_CONNECTION (data->connection))
++  for (l = data->connection_attempts; l; l = g_slist_next (l))
+     {
+-      GSocketConnection *wrapper_connection;
+-
+-      wrapper_connection = g_tcp_wrapper_connection_new (data->connection, data->socket);
+-      g_object_unref (data->connection);
+-      data->connection = (GIOStream *)wrapper_connection;
++      ConnectionAttempt *attempt_entry = l->data;
++      g_cancellable_cancel (attempt_entry->cancellable);
++      connection_attempt_unref (attempt_entry);
+     }
++  g_slist_free (data->connection_attempts);
++  data->connection_attempts = NULL;
+ 
+-  if (!data->completed)
++  g_slist_free_full (data->successful_connections, connection_attempt_unref);
++  data->successful_connections = NULL;
++
++  g_cancellable_cancel (data->enumeration_cancellable);
++}
++
++static void
++g_socket_client_async_connect_complete (ConnectionAttempt *attempt)
++{
++  GSocketClientAsyncConnectData *data = attempt->data;
++  GError *error = NULL;
++  g_assert (attempt->connection);
++  g_assert (!data->completed);
++
++  if (!G_IS_SOCKET_CONNECTION (attempt->connection))
+     {
+-      GError *error = NULL;
++      GSocketConnection *wrapper_connection;
+ 
+-      if (g_cancellable_set_error_if_cancelled (g_task_get_cancellable (data->task), &error))
+-        {
+-          g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_COMPLETE, data->connectable, NULL);
+-          g_task_return_error (data->task, g_steal_pointer (&error));
+-        }
+-      else
+-        {
+-          g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_COMPLETE, data->connectable, data->connection);
+-          g_task_return_pointer (data->task, g_steal_pointer (&data->connection), g_object_unref);
+-        }
++      wrapper_connection = g_tcp_wrapper_connection_new (attempt->connection, attempt->socket);
++      g_object_unref (attempt->connection);
++      attempt->connection = (GIOStream *)wrapper_connection;
++    }
+ 
+-      data->completed = TRUE;
++  data->completed = TRUE;
++  cancel_all_attempts (data);
++
++  if (g_cancellable_set_error_if_cancelled (g_task_get_cancellable (data->task), &error))
++    {
++      g_debug ("GSocketClient: Connection cancelled!");
++      g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_COMPLETE, data->connectable, NULL);
++      g_task_return_error (data->task, g_steal_pointer (&error));
++    }
++  else
++    {
++      g_debug ("GSocketClient: Connection successful!");
++      g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_COMPLETE, data->connectable, attempt->connection);
++      g_task_return_pointer (data->task, g_steal_pointer (&attempt->connection), g_object_unref);
+     }
+ 
++  connection_attempt_unref (attempt);
+   g_object_unref (data->task);
+ }
+ 
+@@ -1470,59 +1495,63 @@ static void
+ enumerator_next_async (GSocketClientAsyncConnectData *data,
+                        gboolean                       add_task_ref)
+ {
+-  /* We need to cleanup the state */
+-  g_clear_object (&data->socket);
+-  g_clear_object (&data->proxy_addr);
+-  g_clear_object (&data->connection);
+-
+   /* Each enumeration takes a ref. This arg just avoids repeated unrefs when
+      an enumeration starts another enumeration */
+   if (add_task_ref)
+     g_object_ref (data->task);
+ 
+   g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_RESOLVING, data->connectable, NULL);
++  g_debug ("GSocketClient: Starting new address enumeration");
+   g_socket_address_enumerator_next_async (data->enumerator,
+-					  g_task_get_cancellable (data->task),
++					  data->enumeration_cancellable,
+ 					  g_socket_client_enumerator_callback,
+ 					  data);
+ }
+ 
++static void try_next_connection_or_finish (GSocketClientAsyncConnectData *, gboolean);
++
+ static void
+ g_socket_client_tls_handshake_callback (GObject      *object,
+ 					GAsyncResult *result,
+ 					gpointer      user_data)
+ {
+-  GSocketClientAsyncConnectData *data = user_data;
++  ConnectionAttempt *attempt = user_data;
++  GSocketClientAsyncConnectData *data = attempt->data;
+ 
+   if (g_tls_connection_handshake_finish (G_TLS_CONNECTION (object),
+ 					 result,
+ 					 &data->last_error))
+     {
+-      g_object_unref (data->connection);
+-      data->connection = G_IO_STREAM (object);
++      g_object_unref (attempt->connection);
++      attempt->connection = G_IO_STREAM (object);
+ 
+-      g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_TLS_HANDSHAKED, data->connectable, data->connection);
+-      g_socket_client_async_connect_complete (data);
++      g_debug ("GSocketClient: TLS handshake succeeded");
++      g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_TLS_HANDSHAKED, data->connectable, attempt->connection);
++      g_socket_client_async_connect_complete (attempt);
+     }
+   else
+     {
+       g_object_unref (object);
+-      enumerator_next_async (data, FALSE);
++      connection_attempt_unref (attempt);
++      g_debug ("GSocketClient: TLS handshake failed: %s", data->last_error->message);
++      try_next_connection_or_finish (data, TRUE);
+     }
+ }
+ 
+ static void
+-g_socket_client_tls_handshake (GSocketClientAsyncConnectData *data)
++g_socket_client_tls_handshake (ConnectionAttempt *attempt)
+ {
++  GSocketClientAsyncConnectData *data = attempt->data;
+   GIOStream *tlsconn;
+ 
+   if (!data->client->priv->tls)
+     {
+-      g_socket_client_async_connect_complete (data);
++      g_socket_client_async_connect_complete (attempt);
+       return;
+     }
+ 
+-  tlsconn = g_tls_client_connection_new (data->connection,
++  g_debug ("GSocketClient: Starting TLS handshake");
++  tlsconn = g_tls_client_connection_new (attempt->connection,
+ 					 data->connectable,
+ 					 &data->last_error);
+   if (tlsconn)
+@@ -1534,11 +1563,12 @@ g_socket_client_tls_handshake (GSocketClientAsyncConnectData *data)
+ 					G_PRIORITY_DEFAULT,
+ 					g_task_get_cancellable (data->task),
+ 					g_socket_client_tls_handshake_callback,
+-					data);
++					attempt);
+     }
+   else
+     {
+-      enumerator_next_async (data, FALSE);
++      connection_attempt_unref (attempt);
++      try_next_connection_or_finish (data, TRUE);
+     }
+ }
+ 
+@@ -1547,23 +1577,38 @@ g_socket_client_proxy_connect_callback (GObject      *object,
+ 					GAsyncResult *result,
+ 					gpointer      user_data)
+ {
+-  GSocketClientAsyncConnectData *data = user_data;
++  ConnectionAttempt *attempt = user_data;
++  GSocketClientAsyncConnectData *data = attempt->data;
+ 
+-  g_object_unref (data->connection);
+-  data->connection = g_proxy_connect_finish (G_PROXY (object),
+-					     result,
+-					     &data->last_error);
+-  if (data->connection)
++  g_object_unref (attempt->connection);
++  attempt->connection = g_proxy_connect_finish (G_PROXY (object),
++                                                result,
++                                                &data->last_error);
++  if (attempt->connection)
+     {
+-      g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_PROXY_NEGOTIATED, data->connectable, data->connection);
++      g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_PROXY_NEGOTIATED, data->connectable, attempt->connection);
+     }
+   else
+     {
+-      enumerator_next_async (data, FALSE);
++      connection_attempt_unref (attempt);
++      try_next_connection_or_finish (data, TRUE);
+       return;
+     }
+ 
+-  g_socket_client_tls_handshake (data);
++  g_socket_client_tls_handshake (attempt);
++}
++
++static void
++complete_connection_with_error (GSocketClientAsyncConnectData *data,
++                                GError                        *error)
++{
++  g_debug ("GSocketClient: Connection failed: %s", error->message);
++  g_assert (!data->completed);
++
++  g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_COMPLETE, data->connectable, NULL);
++  data->completed = TRUE;
++  cancel_all_attempts (data);
++  g_task_return_error (data->task, error);
+ }
+ 
+ static gboolean
+@@ -1577,15 +1622,114 @@ task_completed_or_cancelled (GSocketClientAsyncConnectData *data)
+     return TRUE;
+   else if (g_cancellable_set_error_if_cancelled (cancellable, &error))
+     {
+-      g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_COMPLETE, data->connectable, NULL);
+-      g_task_return_error (task, g_steal_pointer (&error));
+-      data->completed = TRUE;
++      complete_connection_with_error (data, g_steal_pointer (&error));
+       return TRUE;
+     }
+   else
+     return FALSE;
+ }
+ 
++static gboolean
++try_next_successful_connection (GSocketClientAsyncConnectData *data)
++{
++  ConnectionAttempt *attempt;
++  const gchar *protocol;
++  GProxy *proxy;
++
++  if (data->connection_in_progress)
++    return FALSE;
++
++  g_assert (data->successful_connections != NULL);
++  attempt = data->successful_connections->data;
++  g_assert (attempt != NULL);
++  data->successful_connections = g_slist_remove (data->successful_connections, attempt);
++  data->connection_in_progress = TRUE;
++
++  g_debug ("GSocketClient: Starting application layer connection");
++
++  if (!attempt->proxy_addr)
++    {
++      g_socket_client_tls_handshake (g_steal_pointer (&attempt));
++      return TRUE;
++    }
++
++  protocol = g_proxy_address_get_protocol (attempt->proxy_addr);
++
++  /* The connection should not be anything other than TCP,
++   * but let's put a safety guard in case
++   */
++  if (!G_IS_TCP_CONNECTION (attempt->connection))
++    {
++      g_critical ("Trying to proxy over non-TCP connection, this is "
++          "most likely a bug in GLib IO library.");
++
++      g_set_error_literal (&data->last_error,
++          G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
++          _("Proxying over a non-TCP connection is not supported."));
++    }
++  else if (g_hash_table_contains (data->client->priv->app_proxies, protocol))
++    {
++      /* Simply complete the connection, we don't want to do TLS handshake
++       * as the application proxy handling may need proxy handshake first */
++      g_socket_client_async_connect_complete (g_steal_pointer (&attempt));
++      return TRUE;
++    }
++  else if ((proxy = g_proxy_get_default_for_protocol (protocol)))
++    {
++      GIOStream *connection = attempt->connection;
++      GProxyAddress *proxy_addr = attempt->proxy_addr;
++
++      g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_PROXY_NEGOTIATING, data->connectable, attempt->connection);
++      g_debug ("GSocketClient: Starting proxy connection");
++      g_proxy_connect_async (proxy,
++                             connection,
++                             proxy_addr,
++                             g_task_get_cancellable (data->task),
++                             g_socket_client_proxy_connect_callback,
++                             g_steal_pointer (&attempt));
++      g_object_unref (proxy);
++      return TRUE;
++    }
++  else
++    {
++      g_clear_error (&data->last_error);
++
++      g_set_error (&data->last_error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
++          _("Proxy protocol “%s” is not supported."),
++          protocol);
++    }
++
++  data->connection_in_progress = FALSE;
++  g_clear_pointer (&attempt, connection_attempt_unref);
++  return FALSE; /* All non-return paths are failures */
++}
++
++static void
++try_next_connection_or_finish (GSocketClientAsyncConnectData *data,
++                               gboolean                       end_current_connection)
++{
++  if (end_current_connection)
++    data->connection_in_progress = FALSE;
++
++  if (data->connection_in_progress)
++    return;
++
++  /* Keep trying successful connections until one works, each iteration pops one */
++  while (data->successful_connections)
++    {
++      if (try_next_successful_connection (data))
++        return;
++    }
++
++  if (!data->enumeration_completed)
++    {
++      enumerator_next_async (data, FALSE);
++      return;
++    }
++
++  complete_connection_with_error (data, data->last_error);
++}
++
+ static void
+ g_socket_client_connected_callback (GObject      *source,
+ 				    GAsyncResult *result,
+@@ -1593,10 +1737,7 @@ g_socket_client_connected_callback (GObject      *source,
+ {
+   ConnectionAttempt *attempt = user_data;
+   GSocketClientAsyncConnectData *data = attempt->data;
+-  GSList *l;
+   GError *error = NULL;
+-  GProxy *proxy;
+-  const gchar *protocol;
+ 
+   if (task_completed_or_cancelled (data) || g_cancellable_is_cancelled (attempt->cancellable))
+     {
+@@ -1618,11 +1759,12 @@ g_socket_client_connected_callback (GObject      *source,
+         {
+           clarify_connect_error (error, data->connectable, attempt->address);
+           set_last_error (data, error);
++          g_debug ("GSocketClient: Connection attempt failed: %s", error->message);
+           connection_attempt_remove (attempt);
+-          enumerator_next_async (data, FALSE);
+           connection_attempt_unref (attempt);
++          try_next_connection_or_finish (data, FALSE);
+         }
+-      else
++      else /* Silently ignore cancelled attempts */
+         {
+           g_clear_error (&error);
+           g_object_unref (data->task);
+@@ -1632,74 +1774,21 @@ g_socket_client_connected_callback (GObject      *source,
+       return;
+     }
+ 
+-  data->socket = g_steal_pointer (&attempt->socket);
+-  data->connection = g_steal_pointer (&attempt->connection);
+-
+-  for (l = data->connection_attempts; l; l = g_slist_next (l))
+-    {
+-      ConnectionAttempt *attempt_entry = l->data;
+-      g_cancellable_cancel (attempt_entry->cancellable);
+-      connection_attempt_unref (attempt_entry);
+-    }
+-  g_slist_free (data->connection_attempts);
+-  data->connection_attempts = NULL;
+-  connection_attempt_unref (attempt);
+-
+-  g_socket_connection_set_cached_remote_address ((GSocketConnection*)data->connection, NULL);
+-  g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_CONNECTED, data->connectable, data->connection);
++  g_socket_connection_set_cached_remote_address ((GSocketConnection*)attempt->connection, NULL);
++  g_debug ("GSocketClient: TCP connection successful");
++  g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_CONNECTED, data->connectable, attempt->connection);
+ 
+   /* wrong, but backward compatible */
+-  g_socket_set_blocking (data->socket, TRUE);
++  g_socket_set_blocking (attempt->socket, TRUE);
+ 
+-  if (!data->proxy_addr)
+-    {
+-      g_socket_client_tls_handshake (data);
+-      return;
+-    }
+-
+-  protocol = g_proxy_address_get_protocol (data->proxy_addr);
+-
+-  /* The connection should not be anything other than TCP,
+-   * but let's put a safety guard in case
++  /* This ends the parallel "happy eyeballs" portion of connecting.
++     Now that we have a successful tcp connection we will attempt to connect
++     at the TLS/Proxy layer. If those layers fail we will move on to the next
++     connection.
+    */
+-  if (!G_IS_TCP_CONNECTION (data->connection))
+-    {
+-      g_critical ("Trying to proxy over non-TCP connection, this is "
+-          "most likely a bug in GLib IO library.");
+-
+-      g_set_error_literal (&data->last_error,
+-          G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+-          _("Proxying over a non-TCP connection is not supported."));
+-
+-      enumerator_next_async (data, FALSE);
+-    }
+-  else if (g_hash_table_contains (data->client->priv->app_proxies, protocol))
+-    {
+-      /* Simply complete the connection, we don't want to do TLS handshake
+-       * as the application proxy handling may need proxy handshake first */
+-      g_socket_client_async_connect_complete (data);
+-    }
+-  else if ((proxy = g_proxy_get_default_for_protocol (protocol)))
+-    {
+-      g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_PROXY_NEGOTIATING, data->connectable, data->connection);
+-      g_proxy_connect_async (proxy,
+-                             data->connection,
+-                             data->proxy_addr,
+-                             g_task_get_cancellable (data->task),
+-                             g_socket_client_proxy_connect_callback,
+-                             data);
+-      g_object_unref (proxy);
+-    }
+-  else
+-    {
+-      g_clear_error (&data->last_error);
+-
+-      g_set_error (&data->last_error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+-          _("Proxy protocol “%s” is not supported."),
+-          protocol);
+-
+-      enumerator_next_async (data, FALSE);
+-    }
++  connection_attempt_remove (attempt);
++  data->successful_connections = g_slist_append (data->successful_connections, g_steal_pointer (&attempt));
++  try_next_connection_or_finish (data, FALSE);
+ }
+ 
+ static gboolean
+@@ -1707,7 +1796,11 @@ on_connection_attempt_timeout (gpointer data)
+ {
+   ConnectionAttempt *attempt = data;
+ 
+-  enumerator_next_async (attempt->data, TRUE);
++  if (!attempt->data->enumeration_completed)
++    {
++      g_debug ("GSocketClient: Timeout reached, trying another enumeration");
++      enumerator_next_async (attempt->data, TRUE);
++    }
+ 
+   g_clear_pointer (&attempt->timeout_source, g_source_unref);
+   return G_SOURCE_REMOVE;
+@@ -1717,9 +1810,9 @@ static void
+ on_connection_cancelled (GCancellable *cancellable,
+                          gpointer      data)
+ {
+-  GCancellable *attempt_cancellable = data;
++  GCancellable *linked_cancellable = G_CANCELLABLE (data);
+ 
+-  g_cancellable_cancel (attempt_cancellable);
++  g_cancellable_cancel (linked_cancellable);
+ }
+ 
+ static void
+@@ -1743,39 +1836,49 @@ g_socket_client_enumerator_callback (GObject      *object,
+ 						     result, &error);
+   if (address == NULL)
+     {
+-      if (data->connection_attempts)
++      if (G_UNLIKELY (data->enumeration_completed))
++        return;
++
++      data->enumeration_completed = TRUE;
++      g_debug ("GSocketClient: Address enumeration completed (out of addresses)");
++
++      /* As per API docs: We only care about error if its the first call,
++         after that the enumerator is done.
++
++         Note that we don't care about cancellation errors because
++         task_completed_or_cancelled() above should handle that.
++
++         If this fails and nothing is in progress then we will complete task here.
++       */
++      if ((data->enumerated_at_least_once && !data->connection_attempts && !data->connection_in_progress) ||
++          !data->enumerated_at_least_once)
+         {
+-          g_object_unref (data->task);
+-          return;
++          g_debug ("GSocketClient: Address enumeration failed: %s", error ? error->message : NULL);
++          if (data->last_error)
++            {
++              g_clear_error (&error);
++              error = data->last_error;
++              data->last_error = NULL;
++            }
++          else if (!error)
++            {
++              g_set_error_literal (&error, G_IO_ERROR, G_IO_ERROR_FAILED,
++                _("Unknown error on connect"));
++            }
++
++          complete_connection_with_error (data, error);
+         }
+ 
+-      g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_COMPLETE, data->connectable, NULL);
+-      data->completed = TRUE;
+-      if (!error)
+-	{
+-	  if (data->last_error)
+-	    {
+-	      error = data->last_error;
+-	      data->last_error = NULL;
+-	    }
+-	  else
+-	    {
+-	      g_set_error_literal (&error, G_IO_ERROR, G_IO_ERROR_FAILED,
+-				   _("Unknown error on connect"));
+-	    }
+-	}
+-      g_task_return_error (data->task, error);
++      /* Enumeration should never trigger again, drop our ref */
+       g_object_unref (data->task);
+       return;
+     }
+ 
++  data->enumerated_at_least_once = TRUE;
++  g_debug ("GSocketClient: Address enumeration succeeded");
+   g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_RESOLVED,
+ 			      data->connectable, NULL);
+ 
+-  if (G_IS_PROXY_ADDRESS (address) &&
+-      data->client->priv->enable_proxy)
+-    data->proxy_addr = g_object_ref (G_PROXY_ADDRESS (address));
+-
+   g_clear_error (&data->last_error);
+ 
+   socket = create_socket (data->client, address, &data->last_error);
+@@ -1793,6 +1896,10 @@ g_socket_client_enumerator_callback (GObject      *object,
+   attempt->cancellable = g_cancellable_new ();
+   attempt->connection = (GIOStream *)g_socket_connection_factory_create_connection (socket);
+   attempt->timeout_source = g_timeout_source_new (HAPPY_EYEBALLS_CONNECTION_ATTEMPT_TIMEOUT_MS);
++
++  if (G_IS_PROXY_ADDRESS (address) && data->client->priv->enable_proxy)
++    attempt->proxy_addr = g_object_ref (G_PROXY_ADDRESS (address));
++
+   g_source_set_callback (attempt->timeout_source, on_connection_attempt_timeout, attempt, NULL);
+   g_source_attach (attempt->timeout_source, g_task_get_context (data->task));
+   data->connection_attempts = g_slist_append (data->connection_attempts, attempt);
+@@ -1802,6 +1909,7 @@ g_socket_client_enumerator_callback (GObject      *object,
+                            g_object_ref (attempt->cancellable), g_object_unref);
+ 
+   g_socket_connection_set_cached_remote_address ((GSocketConnection *)attempt->connection, address);
++  g_debug ("GSocketClient: Starting TCP connection attempt");
+   g_socket_client_emit_event (data->client, G_SOCKET_CLIENT_CONNECTING, data->connectable, attempt->connection);
+   g_socket_connection_connect_async (G_SOCKET_CONNECTION (attempt->connection),
+ 				     address,
+@@ -1854,24 +1962,48 @@ g_socket_client_connect_async (GSocketClient       *client,
+   else
+     data->enumerator = g_socket_connectable_enumerate (connectable);
+ 
+-  /* The flow and ownership here isn't quite obvious:
+-    - The task starts an async attempt to connect.
+-      - Each attempt holds a single ref on task.
+-      - Each attempt may create new attempts by timing out (not a failure) so
+-        there are multiple attempts happening in parallel.
+-      - Upon failure an attempt will start a new attempt that steals its ref
+-        until there are no more attempts left and it drops its ref.
+-      - Upon success it will cancel all other attempts and continue on
+-        to the rest of the connection (tls, proxies, etc) which do not
+-        happen in parallel and at the very end drop its ref.
+-      - Upon cancellation an attempt drops its ref.
+-   */
++  /* This function tries to match the behavior of g_socket_client_connect ()
++     which is simple enough but much of it is done in parallel to be as responsive
++     as possible as per Happy Eyeballs (RFC 8305). This complicates flow quite a
++     bit but we can describe it in 3 sections:
++
++     Firstly we have address enumeration (DNS):
++       - This may be triggered multiple times by enumerator_next_async().
++       - It also has its own cancellable (data->enumeration_cancellable).
++       - Enumeration is done lazily because GNetworkAddressAddressEnumerator
++         also does work in parallel and may lazily add new addresses.
++       - If the first enumeration errors then the task errors. Otherwise all enumerations
++         will potentially be used (until task or enumeration is cancelled).
++
++      Then we start attempting connections (TCP):
++        - Each connection is independent and kept in a ConnectionAttempt object.
++          - They each hold a ref on the main task and have their own cancellable.
++        - Multiple attempts may happen in parallel as per Happy Eyeballs.
++        - Upon failure or timeouts more connection attempts are made.
++          - If no connections succeed the task errors.
++        - Upon success they are kept in a list of successful connections.
++
++      Lastly we connect at the application layer (TLS, Proxies):
++        - These are done in serial.
++          - The reasoning here is that Happy Eyeballs is about making bad connections responsive
++            at the IP/TCP layers. Issues at the application layer are generally not due to
++            connectivity issues but rather misconfiguration.
++        - Upon failure it will try the next TCP connection until it runs out and
++          the task errors.
++        - Upon success it cancels everything remaining (enumeration and connections)
++          and returns the connection.
++  */
+ 
+   data->task = g_task_new (client, cancellable, callback, user_data);
+   g_task_set_check_cancellable (data->task, FALSE); /* We handle this manually */
+   g_task_set_source_tag (data->task, g_socket_client_connect_async);
+   g_task_set_task_data (data->task, data, (GDestroyNotify)g_socket_client_async_connect_data_free);
+ 
++  data->enumeration_cancellable = g_cancellable_new ();
++  if (cancellable)
++    g_cancellable_connect (cancellable, G_CALLBACK (on_connection_cancelled),
++                           g_object_ref (data->enumeration_cancellable), g_object_unref);
++
+   enumerator_next_async (data, FALSE);
+ }
+ 
+@@ -1990,6 +2122,7 @@ g_socket_client_connect_to_uri_async (GSocketClient        *client,
+     }
+   else
+     {
++      g_debug("g_socket_client_connect_to_uri_async");
+       g_socket_client_connect_async (client,
+ 				     connectable, cancellable,
+ 				     callback, user_data);
+-- 
+2.24.1
+