1/*
  2 * Copyright (c) 2007-2012 Nicira, Inc.
  3 *
  4 * This program is free software; you can redistribute it and/or
  5 * modify it under the terms of version 2 of the GNU General Public
  6 * License as published by the Free Software Foundation.
  7 *
  8 * This program is distributed in the hope that it will be useful, but
  9 * WITHOUT ANY WARRANTY; without even the implied warranty of
 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 11 * General Public License for more details.
 12 *
 13 * You should have received a copy of the GNU General Public License
 14 * along with this program; if not, write to the Free Software
 15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 16 * 02110-1301, USA
 17 */
 18
 19#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 20
 21#include <linux/if_arp.h>
 22#include <linux/if_bridge.h>
 23#include <linux/if_vlan.h>
 24#include <linux/kernel.h>
 25#include <linux/llc.h>
 26#include <linux/rtnetlink.h>
 27#include <linux/skbuff.h>
 28#include <linux/openvswitch.h>
 29#include <linux/export.h>
 30
 31#include <net/ip_tunnels.h>
 32#include <net/rtnetlink.h>
 33
 34#include "datapath.h"
 35#include "vport.h"
 36#include "vport-internal_dev.h"
 37#include "vport-netdev.h"
 38
 39static struct vport_ops ovs_netdev_vport_ops;
 40
 41/* Must be called with rcu_read_lock. */
 42static void netdev_port_receive(struct sk_buff *skb)
 43{
 44	struct vport *vport;
 45
 46	vport = ovs_netdev_get_vport(skb->dev);
 47	if (unlikely(!vport))
 48		goto error;
 49
 50	if (unlikely(skb_warn_if_lro(skb)))
 51		goto error;
 52
 53	/* Make our own copy of the packet.  Otherwise we will mangle the
 54	 * packet for anyone who came before us (e.g. tcpdump via AF_PACKET).
 55	 */
 56	skb = skb_share_check(skb, GFP_ATOMIC);
 57	if (unlikely(!skb))
 58		return;
 59
 60	if (skb->dev->type == ARPHRD_ETHER) {
 61		skb_push(skb, ETH_HLEN);
 62		skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
 63	}
 64	ovs_vport_receive(vport, skb, skb_tunnel_info(skb));
 65	return;
 66error:
 67	kfree_skb(skb);
 68}
 69
 70/* Called with rcu_read_lock and bottom-halves disabled. */
 71static rx_handler_result_t netdev_frame_hook(struct sk_buff **pskb)
 72{
 73	struct sk_buff *skb = *pskb;
 74
 75	if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
 76		return RX_HANDLER_PASS;
 77
 78	netdev_port_receive(skb);
 79	return RX_HANDLER_CONSUMED;
 80}
 81
 82static struct net_device *get_dpdev(const struct datapath *dp)
 83{
 84	struct vport *local;
 85
 86	local = ovs_vport_ovsl(dp, OVSP_LOCAL);
 87	BUG_ON(!local);
 88	return local->dev;
 89}
 90
 91struct vport *ovs_netdev_link(struct vport *vport, const char *name)
 92{
 93	int err;
 94
 95	vport->dev = dev_get_by_name(ovs_dp_get_net(vport->dp), name);
 96	if (!vport->dev) {
 97		err = -ENODEV;
 98		goto error_free_vport;
 99	}
100
101	if (vport->dev->flags & IFF_LOOPBACK ||
102	    (vport->dev->type != ARPHRD_ETHER &&
103	     vport->dev->type != ARPHRD_NONE) ||
104	    ovs_is_internal_dev(vport->dev)) {
105		err = -EINVAL;
106		goto error_put;
107	}
108
109	rtnl_lock();
110	err = netdev_master_upper_dev_link(vport->dev,
111					   get_dpdev(vport->dp), NULL, NULL);
112	if (err)
113		goto error_unlock;
114
115	err = netdev_rx_handler_register(vport->dev, netdev_frame_hook,
116					 vport);
117	if (err)
118		goto error_master_upper_dev_unlink;
119
120	dev_disable_lro(vport->dev);
121	dev_set_promiscuity(vport->dev, 1);
122	vport->dev->priv_flags |= IFF_OVS_DATAPATH;
123	rtnl_unlock();
124
125	return vport;
126
127error_master_upper_dev_unlink:
128	netdev_upper_dev_unlink(vport->dev, get_dpdev(vport->dp));
129error_unlock:
130	rtnl_unlock();
131error_put:
132	dev_put(vport->dev);
133error_free_vport:
134	ovs_vport_free(vport);
135	return ERR_PTR(err);
136}
137EXPORT_SYMBOL_GPL(ovs_netdev_link);
138
139static struct vport *netdev_create(const struct vport_parms *parms)
140{
141	struct vport *vport;
142
143	vport = ovs_vport_alloc(0, &ovs_netdev_vport_ops, parms);
144	if (IS_ERR(vport))
145		return vport;
146
147	return ovs_netdev_link(vport, parms->name);
148}
149
150static void vport_netdev_free(struct rcu_head *rcu)
151{
152	struct vport *vport = container_of(rcu, struct vport, rcu);
153
154	if (vport->dev)
155		dev_put(vport->dev);
156	ovs_vport_free(vport);
157}
158
159void ovs_netdev_detach_dev(struct vport *vport)
160{
161	ASSERT_RTNL();
162	vport->dev->priv_flags &= ~IFF_OVS_DATAPATH;
163	netdev_rx_handler_unregister(vport->dev);
164	netdev_upper_dev_unlink(vport->dev,
165				netdev_master_upper_dev_get(vport->dev));
166	dev_set_promiscuity(vport->dev, -1);
167}
168
169static void netdev_destroy(struct vport *vport)
170{
171	rtnl_lock();
172	if (vport->dev->priv_flags & IFF_OVS_DATAPATH)
173		ovs_netdev_detach_dev(vport);
174	rtnl_unlock();
175
176	call_rcu(&vport->rcu, vport_netdev_free);
177}
178
179void ovs_netdev_tunnel_destroy(struct vport *vport)
180{
181	rtnl_lock();
182	if (vport->dev->priv_flags & IFF_OVS_DATAPATH)
183		ovs_netdev_detach_dev(vport);
184
185	/* We can be invoked by both explicit vport deletion and
186	 * underlying netdev deregistration; delete the link only
187	 * if it's not already shutting down.
188	 */
189	if (vport->dev->reg_state == NETREG_REGISTERED)
190		rtnl_delete_link(vport->dev);
191	dev_put(vport->dev);
192	vport->dev = NULL;
193	rtnl_unlock();
194
195	call_rcu(&vport->rcu, vport_netdev_free);
196}
197EXPORT_SYMBOL_GPL(ovs_netdev_tunnel_destroy);
198
199/* Returns null if this device is not attached to a datapath. */
200struct vport *ovs_netdev_get_vport(struct net_device *dev)
201{
202	if (likely(dev->priv_flags & IFF_OVS_DATAPATH))
203		return (struct vport *)
204			rcu_dereference_rtnl(dev->rx_handler_data);
205	else
206		return NULL;
207}
208
209static struct vport_ops ovs_netdev_vport_ops = {
210	.type		= OVS_VPORT_TYPE_NETDEV,
211	.create		= netdev_create,
212	.destroy	= netdev_destroy,
213	.send		= dev_queue_xmit,
214};
215
216int __init ovs_netdev_init(void)
217{
218	return ovs_vport_ops_register(&ovs_netdev_vport_ops);
219}
220
221void ovs_netdev_exit(void)
222{
223	ovs_vport_ops_unregister(&ovs_netdev_vport_ops);
224}