Re: [PATCH v11 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_EOC when it is disconnected.
>
> The NETDEV_STREAM_CONNECTED event includes the URI of the destination
> address.
>
> Signed-off-by: Laurent Vivier <lvivier@xxxxxxxxxx>
> Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> ---
>  net/stream.c  | 11 +++++++++--
>  qapi/net.json | 46 ++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 55 insertions(+), 2 deletions(-)
>
> diff --git a/net/stream.c b/net/stream.c
> index 0293e38e5b57..821ae3265356 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_eoc(s->nc.name);
> +
>          return G_SOURCE_REMOVE;
>      }
>      buf = buf1;
> @@ -243,9 +246,10 @@ static void net_stream_listen(QIONetListener *listener,
>      g_assert(addr != NULL);
>      uri = socket_uri(addr);
>      qemu_set_info_str(&s->nc, uri);
> -    g_free(uri);
>      qapi_free_SocketAddress(addr);
>  
> +    qapi_event_send_netdev_stream_connected(s->nc.name, uri);
> +    g_free(uri);
>  }
>  
>  static void net_stream_server_listening(QIOTask *task, gpointer opaque)
> @@ -317,12 +321,12 @@ static void net_stream_client_connected(QIOTask *task, 
> gpointer opaque)
>      g_assert(addr != NULL);
>      uri = socket_uri(addr);
>      qemu_set_info_str(&s->nc, uri);
> -    g_free(uri);
>  
>      ret = qemu_socket_try_set_nonblock(sioc->fd);
>      if (addr->type == SOCKET_ADDRESS_TYPE_FD && ret < 0) {
>          qemu_set_info_str(&s->nc, "can't use file descriptor %s (errno %d)",
>                            addr->u.fd.str, -ret);
> +        g_free(uri);
>          qapi_free_SocketAddress(addr);
>          goto error;
>      }
> @@ -338,6 +342,9 @@ 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, uri);
> +    g_free(uri);
> +
>      return;
>  error:
>      object_unref(OBJECT(s->ioc));
> diff --git a/qapi/net.json b/qapi/net.json
> index 6a1a49749294..69f83bceff3f 100644
> --- a/qapi/net.json
> +++ b/qapi/net.json
> @@ -895,3 +895,49 @@
>  ##
>  { '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
> +# @uri: The Uniform Resource Identifier identifying the destination address

Is an URI the appropriate representation here?  It's not how we specify
such addresses elsewhere in QAPI/QMP...

> +#
> +# Since: 7.2
> +#
> +# Example:
> +#
> +# <- { 'event': 'NETDEV_STREAM_CONNECTED',
> +#      'data': {'uri': 'tcp:::1:1234', 'netdev-id': 'netdev0'},
> +#      'timestamp': {'seconds': 1663330564, 'microseconds': 804317} }
> +#
> +# or
> +#
> +# <- { 'event': 'NETDEV_STREAM_CONNECTED',
> +#      'data': {'uri': ''unix:/tmp/qemu0', 'netdev-id': 'netdev0'},
> +#      'timestamp': {'seconds': 1663330564, 'microseconds': 804317} }
> +#
> +##
> +{ 'event': 'NETDEV_STREAM_CONNECTED',
> +  'data': { 'netdev-id': 'str',
> +            'uri': 'str' } }
> +
> +##
> +# @NETDEV_STREAM_EOC:

What does "EOC" mean?

Could this be named NETDEV_STREAM_DISCONNECTED, for symmetry with
NETDEV_STREAM_CONNECTED?

> +#
> +# Emitted when the netdev stream backend is disconnected
> +#
> +# @netdev-id: QEMU netdev id that is disconnected
> +#
> +# Since: 7.2
> +#
> +# Example:
> +#
> +# <- { 'event': 'NETDEV_STREAM_EOC',
> +#      'data': {'netdev-id': 'netdev0'},
> +#      'timestamp': {'seconds': 1663330937, 'microseconds': 526695} }
> +#
> +##
> +{ 'event': 'NETDEV_STREAM_EOC',
> +  'data': { 'netdev-id': 'str' } }