Re: [PATCH] hmp: Changed hmp_netdev_add() using qmp_marshal_netdev_add()

[Eric Blake <eblake@redhat.com>]

On 11/24/20 7:36 AM, Markus Armbruster wrote:
> Markus Armbruster <armbru@redhat.com> writes:
> 
>> Yuri Benditovich <yuri.benditovich@daynix.com> writes:
>>
>>> Please confirm that this patch is intended to solve only the problem with
>>> hmp (and disallow duplicated ids)
>>
>> The intent is to reject duplicate ID and to accept non-duplicate ID, no
>> matter how the device is created (CLI, HMP, QMP) or a prior instance was
>> deleted (HMP, QMP).
>>
>>> With it the netdev that was added from qemu's command line and was deleted
>>> (for example by hmp) still can't be created, correct?
>>
>> Yet another case; back to the drawing board...
> 
> Next try.  Hope this is one holds water :)
> 
> 
> diff --git a/net/net.c b/net/net.c
> index 794c652282..c1dc75fc37 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -978,6 +978,7 @@ static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
>  static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp)
>  {
>      NetClientState *peer = NULL;
> +    NetClientState *nc;
>  
>      if (is_netdev) {
>          if (netdev->type == NET_CLIENT_DRIVER_NIC ||
> @@ -1005,6 +1006,12 @@ static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp)
>          }
>      }
>  
> +    nc = qemu_find_netdev(netdev->id);
> +    if (nc) {
> +        error_setg(errp, "Duplicate ID '%s'", netdev->id);
> +        return -1;
> +    }

Here, we fail if qemu_find_netdev() succeeded, regardless of whether
is_netdev was set...

> +
>      if (net_client_init_fun[netdev->type](netdev, netdev->id, peer, errp) < 0) {
>          /* FIXME drop when all init functions store an Error */
>          if (errp && !*errp) {
> @@ -1015,8 +1022,6 @@ static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp)
>      }
>  
>      if (is_netdev) {
> -        NetClientState *nc;
> -
>          nc = qemu_find_netdev(netdev->id);
>          assert(nc);

and here, when is_netdev is set, we expect qemu_find_netdev() to
succeed.  Does the first hunk need to be 'if (nc && !is_netdev)' ?

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org