Re: [PATCH v12 17/17] net: stream: add QAPI events to report connection state

[Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>]

On 20/10/22 11:16, Laurent Vivier wrote:
> The netdev reports NETDEV_STREAM_CONNECTED event when the backend
> is connected, and NETDEV_STREAM_DISCONNECTED 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 95d6b910407d..8ad757cefbdf 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;
> @@ -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);
Maybe worth converting to g_autofree.

>   }
>   
>   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 39388b1b6c41..569ab7fd37e3 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
> +#
> +# Since: 7.2
> +#
> +# Example:
> +#
> +# <- { 'event': 'NETDEV_STREAM_CONNECTED',
> +#      'data': {'uri': 'tcp:::1:1234', 'netdev-id': 'netdev0'},
Unrelated, but interesting. The URI should be 'tcp:[::1]:1234', we miss
this IPv6 case when parsing SOCKET_ADDRESS_TYPE_INET in socket_uri().

> +#      '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_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' } }