Re: [PATCH v13 17/17] net: stream: add QAPI events to report connection state

[Markus Armbruster <armbru@xxxxxxxxxx>]

Laurent Vivier <lvivier@xxxxxxxxxx> writes:

> The netdev reports NETDEV_STREAM_CONNECTED event when the backend
> is connected, and NETDEV_STREAM_DISCONNECTED when it is disconnected.

Use cases?

Could similar event signalling be useful for other kinds of netdev
backends?

> The NETDEV_STREAM_CONNECTED event includes the URI of the destination
> address.

No more.  Easy fix: scratch "the URI of".

> Signed-off-by: Laurent Vivier <lvivier@xxxxxxxxxx>
> Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> ---
>  net/stream.c  |  9 +++++++--
>  qapi/net.json | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 56 insertions(+), 2 deletions(-)
>
> diff --git a/net/stream.c b/net/stream.c
> index 95d6b910407d..cac01d4d792a 100644
> --- a/net/stream.c
> +++ b/net/stream.c
> @@ -38,6 +38,7 @@
>  #include "io/channel.h"
>  #include "io/channel-socket.h"
>  #include "io/net-listener.h"
> +#include "qapi/qapi-events-net.h"
>  
>  typedef struct NetStreamState {
>      NetClientState nc;
> @@ -168,6 +169,8 @@ static gboolean net_stream_send(QIOChannel *ioc,
>          s->nc.link_down = true;
>          qemu_set_info_str(&s->nc, "");
>  
> +        qapi_event_send_netdev_stream_disconnected(s->nc.name);
> +
>          return G_SOURCE_REMOVE;
>      }
>      buf = buf1;
> @@ -244,8 +247,8 @@ static void net_stream_listen(QIONetListener *listener,
>      uri = socket_uri(addr);
>      qemu_set_info_str(&s->nc, uri);
>      g_free(uri);
> +    qapi_event_send_netdev_stream_connected(s->nc.name, addr);
>      qapi_free_SocketAddress(addr);
> -

Don't add this blank line in PATCH 15, please.

>  }
>  
>  static void net_stream_server_listening(QIOTask *task, gpointer opaque)
> @@ -327,7 +330,6 @@ static void net_stream_client_connected(QIOTask *task, 
> gpointer opaque)
>          goto error;
>      }
>      g_assert(ret == 0);
> -    qapi_free_SocketAddress(addr);
>  
>      net_socket_rs_init(&s->rs, net_stream_rs_finalize, false);
>  
> @@ -338,6 +340,9 @@ static void net_stream_client_connected(QIOTask *task, 
> gpointer opaque)
>                                              s, NULL);
>      s->nc.link_down = false;
>  
> +    qapi_event_send_netdev_stream_connected(s->nc.name, addr);
> +    qapi_free_SocketAddress(addr);
> +
>      return;
>  error:
>      object_unref(OBJECT(s->ioc));

Could put the qapi_free_SocketAddress() in its final place in PATCH 15
already to reduce churn.  Up to you.

> diff --git a/qapi/net.json b/qapi/net.json
> index 39388b1b6c41..c37b24717382 100644
> --- a/qapi/net.json
> +++ b/qapi/net.json
> @@ -895,3 +895,52 @@
>  ##
>  { 'event': 'FAILOVER_NEGOTIATED',
>    'data': {'device-id': 'str'} }
> +
> +##
> +# @NETDEV_STREAM_CONNECTED:
> +#
> +# Emitted when the netdev stream backend is connected
> +#
> +# @netdev-id: QEMU netdev id that is connected
> +# @addr: The destination address
> +#
> +# Since: 7.2
> +#
> +# Example:
> +#
> +# <- { "event": "NETDEV_STREAM_CONNECTED",
> +#      "data": { "netdev-id": "netdev0",
> +#                "addr": { "port": "47666", "ipv6": true,
> +#                          "host": "::1", "type": "inet" } },
> +#      "timestamp": { "seconds": 1666269863, "microseconds": 311222 } }
> +#
> +# or
> +#
> +# <- { "event": "NETDEV_STREAM_CONNECTED",
> +#      "data": { "netdev-id": "netdev0",
> +#                "addr": { "path": "/tmp/qemu0", "type": "unix" } },
> +#      "timestamp": { "seconds": 1666269706, "microseconds": 413651 } }
> +#
> +##
> +{ 'event': 'NETDEV_STREAM_CONNECTED',
> +  'data': { 'netdev-id': 'str',
> +            'addr': 'SocketAddress' } }
> +
> +##
> +# @NETDEV_STREAM_DISCONNECTED:
> +#
> +# Emitted when the netdev stream backend is disconnected
> +#
> +# @netdev-id: QEMU netdev id that is disconnected
> +#
> +# Since: 7.2
> +#
> +# Example:
> +#
> +# <- { 'event': 'NETDEV_STREAM_DISCONNECTED',
> +#      'data': {'netdev-id': 'netdev0'},
> +#      'timestamp': {'seconds': 1663330937, 'microseconds': 526695} }
> +#
> +##
> +{ 'event': 'NETDEV_STREAM_DISCONNECTED',
> +  'data': { 'netdev-id': 'str' } }

Schema looks good to me.