net: allow NICs to be connected to netdevs

Introduce a 'peer' member to VLANClientState as an alternative
to a vlan. The idea being that packets are transfered directly
from peer clients rather than going through a vlan.

Patchworks-ID: 35516
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/net.c b/net.c
index 3f997cc..5d78f04 100644
--- a/net.c
+++ b/net.c
@@ -302,6 +302,7 @@
 }
 
 VLANClientState *qemu_new_vlan_client(VLANState *vlan,
+                                      VLANClientState *peer,
                                       const char *model,
                                       const char *name,
                                       NetCanReceive *can_receive,
@@ -326,9 +327,14 @@
     vc->opaque = opaque;
 
     if (vlan) {
+        assert(!peer);
         vc->vlan = vlan;
         QTAILQ_INSERT_TAIL(&vc->vlan->clients, vc, next);
     } else {
+        if (peer) {
+            vc->peer = peer;
+            peer->peer = vc;
+        }
         QTAILQ_INSERT_TAIL(&non_vlan_clients, vc, next);
     }
 
@@ -341,6 +347,9 @@
         QTAILQ_REMOVE(&vc->vlan->clients, vc, next);
     } else {
         QTAILQ_REMOVE(&non_vlan_clients, vc, next);
+        if (vc->peer) {
+            vc->peer->peer = NULL;
+        }
     }
 
     if (vc->cleanup) {
@@ -866,7 +875,8 @@
     }
 #endif
 
-    s->vc = qemu_new_vlan_client(vlan, model, name, NULL, slirp_receive, NULL,
+    s->vc = qemu_new_vlan_client(vlan, NULL, model, name, NULL,
+                                 slirp_receive, NULL,
                                  net_slirp_cleanup, s);
     snprintf(s->vc->info_str, sizeof(s->vc->info_str),
              "net=%s, restricted=%c", inet_ntoa(net), restricted ? 'y' : 'n');
@@ -1426,8 +1436,9 @@
 
     s = qemu_mallocz(sizeof(TAPState));
     s->fd = fd;
-    s->vc = qemu_new_vlan_client(vlan, model, name, NULL, tap_receive,
-                                 tap_receive_iov, tap_cleanup, s);
+    s->vc = qemu_new_vlan_client(vlan, NULL, model, name, NULL,
+                                 tap_receive, tap_receive_iov,
+                                 tap_cleanup, s);
     tap_read_poll(s, 1);
     snprintf(s->vc->info_str, sizeof(s->vc->info_str), "fd=%d", fd);
     return s;
@@ -1760,8 +1771,9 @@
         free(s);
         return -1;
     }
-    s->vc = qemu_new_vlan_client(vlan, model, name, NULL, vde_receive,
-                                 NULL, vde_cleanup, s);
+    s->vc = qemu_new_vlan_client(vlan, NULL, model, name, NULL,
+                                 vde_receive, NULL,
+                                 vde_cleanup, s);
     qemu_set_fd_handler(vde_datafd(s->vde), vde_to_qemu, NULL, s);
     snprintf(s->vc->info_str, sizeof(s->vc->info_str), "sock=%s,fd=%d",
              sock, vde_datafd(s->vde));
@@ -1999,8 +2011,9 @@
     s = qemu_mallocz(sizeof(NetSocketState));
     s->fd = fd;
 
-    s->vc = qemu_new_vlan_client(vlan, model, name, NULL, net_socket_receive_dgram,
-                                 NULL, net_socket_cleanup, s);
+    s->vc = qemu_new_vlan_client(vlan, NULL, model, name, NULL,
+                                 net_socket_receive_dgram, NULL,
+                                 net_socket_cleanup, s);
     qemu_set_fd_handler(s->fd, net_socket_send_dgram, NULL, s);
 
     /* mcast: save bound address as dst */
@@ -2027,8 +2040,9 @@
     NetSocketState *s;
     s = qemu_mallocz(sizeof(NetSocketState));
     s->fd = fd;
-    s->vc = qemu_new_vlan_client(vlan, model, name, NULL, net_socket_receive,
-                                 NULL, net_socket_cleanup, s);
+    s->vc = qemu_new_vlan_client(vlan, NULL, model, name, NULL,
+                                 net_socket_receive, NULL,
+                                 net_socket_cleanup, s);
     snprintf(s->vc->info_str, sizeof(s->vc->info_str),
              "socket: fd=%d", fd);
     if (is_connected) {
@@ -2308,7 +2322,8 @@
         return -1;
     }
 
-    s->pcap_vc = qemu_new_vlan_client(vlan, device, name, NULL, dump_receive, NULL,
+    s->pcap_vc = qemu_new_vlan_client(vlan, NULL, device, name, NULL,
+                                      dump_receive, NULL,
                                       net_dump_cleanup, s);
     snprintf(s->pcap_vc->info_str, sizeof(s->pcap_vc->info_str),
              "dump to %s (len=%d)", filename, len);