net: fix vnet_hdr handling in solaris tap code

Print an error if the user specifies vnet_hdr=1 on the cmdline.
Signed-off-by: NMark McLoughlin <markmc@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

net/tap-solaris.c

@@ -180,6 +180,17 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required
        return -1;
     }
     pstrcpy(ifname, ifname_size, dev);
+    if (*vnet_hdr) {
+        /* Solaris doesn't have IFF_VNET_HDR */
+        *vnet_hdr = 0;
+
+        if (vnet_hdr_required && !*vnet_hdr) {
+            qemu_error("vnet_hdr=1 requested, but no kernel "
+                       "support for IFF_VNET_HDR available");
+            close(fd);
+            return -1;
+        }
+    }
     fcntl(fd, F_SETFL, O_NONBLOCK);
     return fd;
 }