qapi: Change Netdev into a flat union

This is a mostly-mechanical conversion that creates a new flat
union 'Netdev' QAPI type that covers all the branches of the
former 'NetClientOptions' simple union, where the branches are
now listed in a new 'NetClientDriver' enum rather than generated
from the simple union.  The existence of a flat union has no
change to the command line syntax accepted for new code, and
will make it possible for a future patch to switch the QMP
command to parse a boxed union for no change to valid QMP; but
it does have some ripple effect on the C code when dealing with
the new types.

While making the conversion, note that the 'NetLegacy' type
remains unchanged: it applies only to legacy command line options,
and will not be ported to QMP, so it should remain a wrapper
around a simple union; to avoid confusion, the type named
'NetClientOptions' is now gone, and we introduce 'NetLegacyOptions'
in its place.  Then, in the C code, we convert from NetLegacy to
Netdev as soon as possible, so that the bulk of the net stack
only has to deal with one QAPI type, not two.  Note that since
the old legacy code always rejected 'hubport', we can just omit
that branch from the new 'NetLegacyOptions' simple union.

Based on an idea originally by Zoltán Kővágó <DirtY.iCE.hu@gmail.com>:
Message-Id: <01a527fbf1a5de880091f98cf011616a78adeeee.1441627176.git.DirtY.iCE.hu@gmail.com>
although the sed script in that patch no longer applies due to
other changes in the tree since then, and I also did some manual
cleanups (such as fixing whitespace to keep checkpatch happy).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1468468228-27827-13-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Fixup from Eric squashed in]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

1 files changed, 85 insertions, 48 deletions

diff --git a/net/net.c b/net/net.c
index d80fd82210..4a7f392baf 100644
--- a/net/net.c
+++ b/net/net.c
@@ -289,7 +289,7 @@ NICState *qemu_new_nic(NetClientInfo *info,
     NICState *nic;
     int i, queues = MAX(1, conf->peers.queues);
 
-    assert(info->type == NET_CLIENT_OPTIONS_KIND_NIC);
+    assert(info->type == NET_CLIENT_DRIVER_NIC);
     assert(info->size >= sizeof(NICState));
 
     nic = g_malloc0(info->size + sizeof(NetClientState) * queues);
@@ -360,13 +360,13 @@ void qemu_del_net_client(NetClientState *nc)
     int queues, i;
     NetFilterState *nf, *next;
 
-    assert(nc->info->type != NET_CLIENT_OPTIONS_KIND_NIC);
+    assert(nc->info->type != NET_CLIENT_DRIVER_NIC);
 
     /* If the NetClientState belongs to a multiqueue backend, we will change all
      * other NetClientStates also.
      */
     queues = qemu_find_net_clients_except(nc->name, ncs,
-                                          NET_CLIENT_OPTIONS_KIND_NIC,
+                                          NET_CLIENT_DRIVER_NIC,
                                           MAX_QUEUE_NUM);
     assert(queues != 0);
 
@@ -375,7 +375,7 @@ void qemu_del_net_client(NetClientState *nc)
     }
 
     /* If there is a peer NIC, delete and cleanup client, but do not free. */
-    if (nc->peer && nc->peer->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
+    if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
         NICState *nic = qemu_get_nic(nc->peer);
         if (nic->peer_deleted) {
             return;
@@ -431,7 +431,7 @@ void qemu_foreach_nic(qemu_nic_foreach func, void *opaque)
     NetClientState *nc;
 
     QTAILQ_FOREACH(nc, &net_clients, next) {
-        if (nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
+        if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
             if (nc->queue_index == 0) {
                 func(qemu_get_nic(nc), opaque);
             }
@@ -603,7 +603,7 @@ void qemu_flush_or_purge_queued_packets(NetClientState *nc, bool purge)
 {
     nc->receive_disabled = 0;
 
-    if (nc->peer && nc->peer->info->type == NET_CLIENT_OPTIONS_KIND_HUBPORT) {
+    if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_HUBPORT) {
         if (net_hub_flush(nc->peer)) {
             qemu_notify_event();
         }
@@ -777,7 +777,7 @@ NetClientState *qemu_find_netdev(const char *id)
     NetClientState *nc;
 
     QTAILQ_FOREACH(nc, &net_clients, next) {
-        if (nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC)
+        if (nc->info->type == NET_CLIENT_DRIVER_NIC)
             continue;
         if (!strcmp(nc->name, id)) {
             return nc;
@@ -788,7 +788,7 @@ NetClientState *qemu_find_netdev(const char *id)
 }
 
 int qemu_find_net_clients_except(const char *id, NetClientState **ncs,
-                                 NetClientOptionsKind type, int max)
+                                 NetClientDriver type, int max)
 {
     NetClientState *nc;
     int ret = 0;
@@ -869,8 +869,8 @@ static int net_init_nic(const Netdev *netdev, const char *name,
     NICInfo *nd;
     const NetLegacyNicOptions *nic;
 
-    assert(netdev->opts->type == NET_CLIENT_OPTIONS_KIND_NIC);
-    nic = netdev->opts->u.nic.data;
+    assert(netdev->type == NET_CLIENT_DRIVER_NIC);
+    nic = &netdev->u.nic;
 
     idx = nic_get_free_idx();
     if (idx == -1 || nb_nics >= MAX_NICS) {
@@ -930,39 +930,38 @@ static int net_init_nic(const Netdev *netdev, const char *name,
 }
 
 
-static int (* const net_client_init_fun[NET_CLIENT_OPTIONS_KIND__MAX])(
+static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
     const Netdev *netdev,
     const char *name,
     NetClientState *peer, Error **errp) = {
-        [NET_CLIENT_OPTIONS_KIND_NIC]       = net_init_nic,
+        [NET_CLIENT_DRIVER_NIC]       = net_init_nic,
 #ifdef CONFIG_SLIRP
-        [NET_CLIENT_OPTIONS_KIND_USER]      = net_init_slirp,
+        [NET_CLIENT_DRIVER_USER]      = net_init_slirp,
 #endif
-        [NET_CLIENT_OPTIONS_KIND_TAP]       = net_init_tap,
-        [NET_CLIENT_OPTIONS_KIND_SOCKET]    = net_init_socket,
+        [NET_CLIENT_DRIVER_TAP]       = net_init_tap,
+        [NET_CLIENT_DRIVER_SOCKET]    = net_init_socket,
 #ifdef CONFIG_VDE
-        [NET_CLIENT_OPTIONS_KIND_VDE]       = net_init_vde,
+        [NET_CLIENT_DRIVER_VDE]       = net_init_vde,
 #endif
 #ifdef CONFIG_NETMAP
-        [NET_CLIENT_OPTIONS_KIND_NETMAP]    = net_init_netmap,
+        [NET_CLIENT_DRIVER_NETMAP]    = net_init_netmap,
 #endif
-        [NET_CLIENT_OPTIONS_KIND_DUMP]      = net_init_dump,
+        [NET_CLIENT_DRIVER_DUMP]      = net_init_dump,
 #ifdef CONFIG_NET_BRIDGE
-        [NET_CLIENT_OPTIONS_KIND_BRIDGE]    = net_init_bridge,
+        [NET_CLIENT_DRIVER_BRIDGE]    = net_init_bridge,
 #endif
-        [NET_CLIENT_OPTIONS_KIND_HUBPORT]   = net_init_hubport,
+        [NET_CLIENT_DRIVER_HUBPORT]   = net_init_hubport,
 #ifdef CONFIG_VHOST_NET_USED
-        [NET_CLIENT_OPTIONS_KIND_VHOST_USER] = net_init_vhost_user,
+        [NET_CLIENT_DRIVER_VHOST_USER] = net_init_vhost_user,
 #endif
 #ifdef CONFIG_L2TPV3
-        [NET_CLIENT_OPTIONS_KIND_L2TPV3]    = net_init_l2tpv3,
+        [NET_CLIENT_DRIVER_L2TPV3]    = net_init_l2tpv3,
 #endif
 };
 
 
 static int net_client_init1(const void *object, int is_netdev, Error **errp)
 {
-    const NetClientOptions *opts;
     Netdev legacy = {0};
     const Netdev *netdev;
     const char *name;
@@ -970,34 +969,72 @@ static int net_client_init1(const void *object, int is_netdev, Error **errp)
 
     if (is_netdev) {
         netdev = object;
-        opts = netdev->opts;
         name = netdev->id;
 
-        if (opts->type == NET_CLIENT_OPTIONS_KIND_DUMP ||
-            opts->type == NET_CLIENT_OPTIONS_KIND_NIC ||
-            !net_client_init_fun[opts->type]) {
+        if (netdev->type == NET_CLIENT_DRIVER_DUMP ||
+            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;
-        opts = legacy.opts = net->opts;
         netdev = &legacy;
         /* missing optional values have been initialized to "all bits zero" */
         name = net->has_id ? net->id : net->name;
 
-        if (opts->type == NET_CLIENT_OPTIONS_KIND_NONE) {
+        /* Map the old options to the new flat type */
+        switch (opts->type) {
+        case NET_LEGACY_OPTIONS_KIND_NONE:
             return 0; /* nothing to do */
-        }
-        if (opts->type == NET_CLIENT_OPTIONS_KIND_HUBPORT) {
-            error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
-                       "a net type");
-            return -1;
+        case NET_LEGACY_OPTIONS_KIND_NIC:
+            legacy.type = NET_CLIENT_DRIVER_NIC;
+            legacy.u.nic = *opts->u.nic.data;
+            break;
+        case NET_LEGACY_OPTIONS_KIND_USER:
+            legacy.type = NET_CLIENT_DRIVER_USER;
+            legacy.u.user = *opts->u.user.data;
+            break;
+        case NET_LEGACY_OPTIONS_KIND_TAP:
+            legacy.type = NET_CLIENT_DRIVER_TAP;
+            legacy.u.tap = *opts->u.tap.data;
+            break;
+        case NET_LEGACY_OPTIONS_KIND_L2TPV3:
+            legacy.type = NET_CLIENT_DRIVER_L2TPV3;
+            legacy.u.l2tpv3 = *opts->u.l2tpv3.data;
+            break;
+        case NET_LEGACY_OPTIONS_KIND_SOCKET:
+            legacy.type = NET_CLIENT_DRIVER_SOCKET;
+            legacy.u.socket = *opts->u.socket.data;
+            break;
+        case NET_LEGACY_OPTIONS_KIND_VDE:
+            legacy.type = NET_CLIENT_DRIVER_VDE;
+            legacy.u.vde = *opts->u.vde.data;
+            break;
+        case NET_LEGACY_OPTIONS_KIND_DUMP:
+            legacy.type = NET_CLIENT_DRIVER_DUMP;
+            legacy.u.dump = *opts->u.dump.data;
+            break;
+        case NET_LEGACY_OPTIONS_KIND_BRIDGE:
+            legacy.type = NET_CLIENT_DRIVER_BRIDGE;
+            legacy.u.bridge = *opts->u.bridge.data;
+            break;
+        case NET_LEGACY_OPTIONS_KIND_NETMAP:
+            legacy.type = NET_CLIENT_DRIVER_NETMAP;
+            legacy.u.netmap = *opts->u.netmap.data;
+            break;
+        case NET_LEGACY_OPTIONS_KIND_VHOST_USER:
+            legacy.type = NET_CLIENT_DRIVER_VHOST_USER;
+            legacy.u.vhost_user = *opts->u.vhost_user.data;
+            break;
+        default:
+            abort();
         }
 
-        if (!net_client_init_fun[opts->type]) {
+        if (!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)");
@@ -1005,17 +1042,17 @@ static int net_client_init1(const void *object, int is_netdev, Error **errp)
         }
 
         /* Do not add to a vlan if it's a nic with a netdev= parameter. */
-        if (opts->type != NET_CLIENT_OPTIONS_KIND_NIC ||
+        if (netdev->type != NET_CLIENT_DRIVER_NIC ||
             !opts->u.nic.data->has_netdev) {
             peer = net_hub_add_port(net->has_vlan ? net->vlan : 0, NULL);
         }
     }
 
-    if (net_client_init_fun[opts->type](netdev, name, peer, errp) < 0) {
+    if (net_client_init_fun[netdev->type](netdev, name, peer, errp) < 0) {
         /* FIXME drop when all init functions store an Error */
         if (errp && !*errp) {
             error_setg(errp, QERR_DEVICE_INIT_FAILED,
-                       NetClientOptionsKind_lookup[opts->type]);
+                       NetClientDriver_lookup[netdev->type]);
         }
         return -1;
     }
@@ -1135,7 +1172,7 @@ void hmp_host_net_remove(Monitor *mon, const QDict *qdict)
                      device, vlan_id);
         return;
     }
-    if (nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
+    if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
         error_report("invalid host network device '%s'", device);
         return;
     }
@@ -1226,7 +1263,7 @@ void print_net_client(Monitor *mon, NetClientState *nc)
 
     monitor_printf(mon, "%s: index=%d,type=%s,%s\n", nc->name,
                    nc->queue_index,
-                   NetClientOptionsKind_lookup[nc->info->type],
+                   NetClientDriver_lookup[nc->info->type],
                    nc->info_str);
     if (!QTAILQ_EMPTY(&nc->filters)) {
         monitor_printf(mon, "filters:\n");
@@ -1256,7 +1293,7 @@ RxFilterInfoList *qmp_query_rx_filter(bool has_name, const char *name,
         }
 
         /* only query rx-filter information of NIC */
-        if (nc->info->type != NET_CLIENT_OPTIONS_KIND_NIC) {
+        if (nc->info->type != NET_CLIENT_DRIVER_NIC) {
             if (has_name) {
                 error_setg(errp, "net client(%s) isn't a NIC", name);
                 return NULL;
@@ -1302,7 +1339,7 @@ RxFilterInfoList *qmp_query_rx_filter(bool has_name, const char *name,
 void hmp_info_network(Monitor *mon, const QDict *qdict)
 {
     NetClientState *nc, *peer;
-    NetClientOptionsKind type;
+    NetClientDriver type;
 
     net_hub_info(mon);
 
@@ -1315,10 +1352,10 @@ void hmp_info_network(Monitor *mon, const QDict *qdict)
             continue;
         }
 
-        if (!peer || type == NET_CLIENT_OPTIONS_KIND_NIC) {
+        if (!peer || type == NET_CLIENT_DRIVER_NIC) {
             print_net_client(mon, nc);
         } /* else it's a netdev connected to a NIC, printed with the NIC */
-        if (peer && type == NET_CLIENT_OPTIONS_KIND_NIC) {
+        if (peer && type == NET_CLIENT_DRIVER_NIC) {
             monitor_printf(mon, " \\ ");
             print_net_client(mon, peer);
         }
@@ -1332,7 +1369,7 @@ void qmp_set_link(const char *name, bool up, Error **errp)
     int queues, i;
 
     queues = qemu_find_net_clients_except(name, ncs,
-                                          NET_CLIENT_OPTIONS_KIND__MAX,
+                                          NET_CLIENT_DRIVER__MAX,
                                           MAX_QUEUE_NUM);
 
     if (queues == 0) {
@@ -1359,7 +1396,7 @@ void qmp_set_link(const char *name, bool up, Error **errp)
          * multiple clients that can still communicate with each other in
          * disconnected mode. For now maintain this compatibility.
          */
-        if (nc->peer->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
+        if (nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
             for (i = 0; i < queues; i++) {
                 ncs[i]->peer->link_down = !up;
             }
@@ -1400,7 +1437,7 @@ void net_cleanup(void)
      */
     while (!QTAILQ_EMPTY(&net_clients)) {
         nc = QTAILQ_FIRST(&net_clients);
-        if (nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
+        if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
             qemu_del_nic(qemu_get_nic(nc));
         } else {
             qemu_del_net_client(nc);
@@ -1420,7 +1457,7 @@ void net_check_clients(void)
     QTAILQ_FOREACH(nc, &net_clients, next) {
         if (!nc->peer) {
             fprintf(stderr, "Warning: %s %s has no peer\n",
-                    nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC ?
+                    nc->info->type == NET_CLIENT_DRIVER_NIC ?
                     "nic" : "netdev", nc->name);
         }
     }