VSOCK: Add vsockmon tap functions

Add tap functions that can be used by the vsock transports to
deliver packets to vsockmon virtual network devices.

Signed-off-by: Gerard Garcia <ggarcia@deic.uab.cat>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/MAINTAINERS b/MAINTAINERS
index b283d5e..fdab4f9 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13317,6 +13317,7 @@ L:      netdev@vger.kernel.org
 S:     Maintained
 F:     include/linux/virtio_vsock.h
 F:     include/uapi/linux/virtio_vsock.h
+F:     net/vmw_vsock/af_vsock_tap.c
 F:     net/vmw_vsock/virtio_transport_common.c
 F:     net/vmw_vsock/virtio_transport.c
 F:     drivers/vhost/vsock.c

diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index f32ed9a..f9fb566 100644 (file)
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -188,4 +188,17 @@ struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
 void vsock_remove_sock(struct vsock_sock *vsk);
 void vsock_for_each_connected_socket(void (*fn)(struct sock *sk));
 
+/**** TAP ****/
+
+struct vsock_tap {
+       struct net_device *dev;
+       struct module *module;
+       struct list_head list;
+};
+
+int vsock_init_tap(void);
+int vsock_add_tap(struct vsock_tap *vt);
+int vsock_remove_tap(struct vsock_tap *vt);
+void vsock_deliver_tap(struct sk_buff *build_skb(void *opaque), void *opaque);
+
 #endif /* __AF_VSOCK_H__ */

diff --git a/include/uapi/linux/if_arp.h b/include/uapi/linux/if_arp.h
index 4d024d7..cf73510 100644 (file)
--- a/include/uapi/linux/if_arp.h
+++ b/include/uapi/linux/if_arp.h
@@ -95,6 +95,7 @@
 #define ARPHRD_IP6GRE  823             /* GRE over IPv6                */
 #define ARPHRD_NETLINK 824             /* Netlink header               */
 #define ARPHRD_6LOWPAN 825             /* IPv6 over LoWPAN             */
+#define ARPHRD_VSOCKMON        826             /* Vsock monitor header         */
 
 #define ARPHRD_VOID      0xFFFF        /* Void type, nothing is known */
 #define ARPHRD_NONE      0xFFFE        /* zero header length */

diff --git a/net/vmw_vsock/Makefile b/net/vmw_vsock/Makefile
index bc27c70..09fc2eb 100644 (file)
--- a/net/vmw_vsock/Makefile
+++ b/net/vmw_vsock/Makefile
@@ -3,7 +3,7 @@ obj-$(CONFIG_VMWARE_VMCI_VSOCKETS) += vmw_vsock_vmci_transport.o
 obj-$(CONFIG_VIRTIO_VSOCKETS) += vmw_vsock_virtio_transport.o
 obj-$(CONFIG_VIRTIO_VSOCKETS_COMMON) += vmw_vsock_virtio_transport_common.o
 
-vsock-y += af_vsock.o vsock_addr.o
+vsock-y += af_vsock.o af_vsock_tap.o vsock_addr.o
 
 vmw_vsock_vmci_transport-y += vmci_transport.o vmci_transport_notify.o \
        vmci_transport_notify_qstate.o

diff --git a/net/vmw_vsock/af_vsock_tap.c b/net/vmw_vsock/af_vsock_tap.c
new file mode 100644 (file)
index 0000000..98f09b5
--- /dev/null
+++ b/net/vmw_vsock/af_vsock_tap.c
@@ -0,0 +1,114 @@
+/*
+ * Tap functions for AF_VSOCK sockets.
+ *
+ * Code based on net/netlink/af_netlink.c tap functions.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <net/sock.h>
+#include <net/af_vsock.h>
+#include <linux/if_arp.h>
+
+static DEFINE_SPINLOCK(vsock_tap_lock);
+static struct list_head vsock_tap_all __read_mostly =
+                               LIST_HEAD_INIT(vsock_tap_all);
+
+int vsock_add_tap(struct vsock_tap *vt)
+{
+       if (unlikely(vt->dev->type != ARPHRD_VSOCKMON))
+               return -EINVAL;
+
+       __module_get(vt->module);
+
+       spin_lock(&vsock_tap_lock);
+       list_add_rcu(&vt->list, &vsock_tap_all);
+       spin_unlock(&vsock_tap_lock);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(vsock_add_tap);
+
+int vsock_remove_tap(struct vsock_tap *vt)
+{
+       struct vsock_tap *tmp;
+       bool found = false;
+
+       spin_lock(&vsock_tap_lock);
+
+       list_for_each_entry(tmp, &vsock_tap_all, list) {
+               if (vt == tmp) {
+                       list_del_rcu(&vt->list);
+                       found = true;
+                       goto out;
+               }
+       }
+
+       pr_warn("vsock_remove_tap: %p not found\n", vt);
+out:
+       spin_unlock(&vsock_tap_lock);
+
+       synchronize_net();
+
+       if (found)
+               module_put(vt->module);
+
+       return found ? 0 : -ENODEV;
+}
+EXPORT_SYMBOL_GPL(vsock_remove_tap);
+
+static int __vsock_deliver_tap_skb(struct sk_buff *skb,
+                                  struct net_device *dev)
+{
+       int ret = 0;
+       struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
+
+       if (nskb) {
+               dev_hold(dev);
+
+               nskb->dev = dev;
+               ret = dev_queue_xmit(nskb);
+               if (unlikely(ret > 0))
+                       ret = net_xmit_errno(ret);
+
+               dev_put(dev);
+       }
+
+       return ret;
+}
+
+static void __vsock_deliver_tap(struct sk_buff *skb)
+{
+       int ret;
+       struct vsock_tap *tmp;
+
+       list_for_each_entry_rcu(tmp, &vsock_tap_all, list) {
+               ret = __vsock_deliver_tap_skb(skb, tmp->dev);
+               if (unlikely(ret))
+                       break;
+       }
+}
+
+void vsock_deliver_tap(struct sk_buff *build_skb(void *opaque), void *opaque)
+{
+       struct sk_buff *skb;
+
+       rcu_read_lock();
+
+       if (likely(list_empty(&vsock_tap_all)))
+               goto out;
+
+       skb = build_skb(opaque);
+       if (skb) {
+               __vsock_deliver_tap(skb);
+               consume_skb(skb);
+       }
+
+out:
+       rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(vsock_deliver_tap);