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;
+    }
+
     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);
         nc->is_netdev = true;
@@ -1137,6 +1142,7 @@ void qmp_netdev_add(Netdev *netdev, Error **errp)
 void qmp_netdev_del(const char *id, Error **errp)
 {
     NetClientState *nc;
+    QemuOpts *opts;

     nc = qemu_find_netdev(id);
     if (!nc) {
@@ -1151,6 +1157,16 @@ void qmp_netdev_del(const char *id, Error **errp)
     }

     qemu_del_net_client(nc);
+
+    /*
+     * Wart: we need to delete the QemuOpts associated with netdevs
+     * created via CLI or HMP, to avoid bogus "Duplicate ID" errors in
+     * HMP netdev_add.
+     */
+    opts = qemu_opts_find(qemu_find_opts("netdev"), id);
+    if (opts) {
+        qemu_opts_del(opts);
+    }
 }

 static void netfilter_print_info(Monitor *mon, NetFilterState *nf)
--
2.26.2