net: Drop the NetLegacy structure, always use Netdev instead

Now that the "name" parameter is gone, there is hardly any difference
between NetLegacy and Netdev anymore, so we can drop NetLegacy and always
use Netdev to simplify the code quite a bit.

The only two differences that were really left between Netdev and NetLegacy:

1) NetLegacy does not allow a "hubport" type. We can continue to block
   this with a simple check in net_client_init1() for this type.

2) The "id" parameter was optional in NetLegacy (and an internal id
   was chosen via assign_name() during initialization), but it is mandatory
   for Netdev. To avoid that the visitor code bails out here, we have to
   add an internal id to the QemuOpts already earlier now.

Signed-off-by: Thomas Huth <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
Signed-off-by: Jason Wang <[email protected]>

Author: huth

net/net.c

@@ -965,72 +965,23 @@ static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
 };
 
 
-static int net_client_init1(const void *object, bool is_netdev, Error **errp)
+static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp)
 {
-    Netdev legacy = {0};
-    const Netdev *netdev;
     NetClientState *peer = NULL;
 
     if (is_netdev) {
-        netdev = object;
-
         if (netdev->type == NET_CLIENT_DRIVER_NIC ||
             !net_client_init_fun[netdev->type]) {
             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
                        "a netdev backend type");
             return -1;
         }
     } else {
-        const NetLegacy *net = object;
-        const NetLegacyOptions *opts = net->opts;
-        legacy.id = net->id;
-        netdev = &legacy;
-
-        /* Map the old options to the new flat type */
-        switch (opts->type) {
-        case NET_LEGACY_OPTIONS_TYPE_NONE:
+        if (netdev->type == NET_CLIENT_DRIVER_NONE) {
             return 0; /* nothing to do */
-        case NET_LEGACY_OPTIONS_TYPE_NIC:
-            legacy.type = NET_CLIENT_DRIVER_NIC;
-            legacy.u.nic = opts->u.nic;
-            break;
-        case NET_LEGACY_OPTIONS_TYPE_USER:
-            legacy.type = NET_CLIENT_DRIVER_USER;
-            legacy.u.user = opts->u.user;
-            break;
-        case NET_LEGACY_OPTIONS_TYPE_TAP:
-            legacy.type = NET_CLIENT_DRIVER_TAP;
-            legacy.u.tap = opts->u.tap;
-            break;
-        case NET_LEGACY_OPTIONS_TYPE_L2TPV3:
-            legacy.type = NET_CLIENT_DRIVER_L2TPV3;
-            legacy.u.l2tpv3 = opts->u.l2tpv3;
-            break;
-        case NET_LEGACY_OPTIONS_TYPE_SOCKET:
-            legacy.type = NET_CLIENT_DRIVER_SOCKET;
-            legacy.u.socket = opts->u.socket;
-            break;
-        case NET_LEGACY_OPTIONS_TYPE_VDE:
-            legacy.type = NET_CLIENT_DRIVER_VDE;
-            legacy.u.vde = opts->u.vde;
-            break;
-        case NET_LEGACY_OPTIONS_TYPE_BRIDGE:
-            legacy.type = NET_CLIENT_DRIVER_BRIDGE;
-            legacy.u.bridge = opts->u.bridge;
-            break;
-        case NET_LEGACY_OPTIONS_TYPE_NETMAP:
-            legacy.type = NET_CLIENT_DRIVER_NETMAP;
-            legacy.u.netmap = opts->u.netmap;
-            break;
-        case NET_LEGACY_OPTIONS_TYPE_VHOST_USER:
-            legacy.type = NET_CLIENT_DRIVER_VHOST_USER;
-            legacy.u.vhost_user = opts->u.vhost_user;
-            break;
-        default:
-            abort();
         }
-
-        if (!net_client_init_fun[netdev->type]) {
+        if (netdev->type == NET_CLIENT_DRIVER_HUBPORT ||
+            !net_client_init_fun[netdev->type]) {
             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
                        "a net backend type (maybe it is not compiled "
                        "into this binary)");
@@ -1039,7 +990,7 @@ static int net_client_init1(const void *object, bool is_netdev, Error **errp)
 
         /* Do not add to a hub if it's a nic with a netdev= parameter. */
         if (netdev->type != NET_CLIENT_DRIVER_NIC ||
-            !opts->u.nic.has_netdev) {
+            !netdev->u.nic.has_netdev) {
             peer = net_hub_add_port(0, NULL, NULL);
         }
     }
@@ -1100,7 +1051,7 @@ static void show_netdevs(void)
 static int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
 {
     gchar **substrings = NULL;
-    void *object = NULL;
+    Netdev *object = NULL;
     Error *err = NULL;
     int ret = -1;
     Visitor *v = opts_visitor_new(opts);
@@ -1143,21 +1094,19 @@ static int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
         }
     }
 
-    if (is_netdev) {
-        visit_type_Netdev(v, NULL, (Netdev **)&object, &err);
-    } else {
-        visit_type_NetLegacy(v, NULL, (NetLegacy **)&object, &err);
+    /* Create an ID for -net if the user did not specify one */
+    if (!is_netdev && !qemu_opts_id(opts)) {
+        static int idx;
+        qemu_opts_set_id(opts, g_strdup_printf("__org.qemu.net%i", idx++));
     }
 
+    visit_type_Netdev(v, NULL, &object, &err);
+
     if (!err) {
         ret = net_client_init1(object, is_netdev, &err);
     }
 
-    if (is_netdev) {
-        qapi_free_Netdev(object);
-    } else {
-        qapi_free_NetLegacy(object);
-    }
+    qapi_free_Netdev(object);
 
 out:
     error_propagate(errp, err);

qapi/net.json

@@ -467,52 +467,6 @@
     'netmap':   'NetdevNetmapOptions',
     'vhost-user': 'NetdevVhostUserOptions' } }
 
-##
-# @NetLegacy:
-#
-# Captures the configuration of a network device; legacy.
-#
-# @id: identifier for monitor commands
-#
-# @opts: device type specific properties (legacy)
-#
-# Since: 1.2
-##
-{ 'struct': 'NetLegacy',
-  'data': {
-    '*id':   'str',
-    'opts':  'NetLegacyOptions' } }
-
-##
-# @NetLegacyOptionsType:
-#
-# Since: 1.2
-##
-{ 'enum': 'NetLegacyOptionsType',
-  'data': ['none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'vde',
-           'bridge', 'netmap', 'vhost-user'] }
-
-##
-# @NetLegacyOptions:
-#
-# Like Netdev, but for use only by the legacy command line options
-#
-# Since: 1.2
-##
-{ 'union': 'NetLegacyOptions',
-  'base': { 'type': 'NetLegacyOptionsType' },
-  'discriminator': 'type',
-  'data': {
-    'nic':      'NetLegacyNicOptions',
-    'user':     'NetdevUserOptions',
-    'tap':      'NetdevTapOptions',
-    'l2tpv3':   'NetdevL2TPv3Options',
-    'socket':   'NetdevSocketOptions',
-    'vde':      'NetdevVdeOptions',
-    'bridge':   'NetdevBridgeOptions',
-    'netmap':   'NetdevNetmapOptions',
-    'vhost-user': 'NetdevVhostUserOptions' } }
-
 ##
 # @NetFilterDirection:
 #