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	skb_push(skb, ETH_HLEN);
61	skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
62	ovs_vport_receive(vport, skb, skb_tunnel_info(skb));
63	return;
64error:
65	kfree_skb(skb);
66}
67
68/* Called with rcu_read_lock and bottom-halves disabled. */
69static rx_handler_result_t netdev_frame_hook(struct sk_buff **pskb)
70{
71	struct sk_buff *skb = *pskb;
72
73	if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
74		return RX_HANDLER_PASS;
75
76	netdev_port_receive(skb);
77	return RX_HANDLER_CONSUMED;
78}
79
80static struct net_device *get_dpdev(const struct datapath *dp)
81{
82	struct vport *local;
83
84	local = ovs_vport_ovsl(dp, OVSP_LOCAL);
85	BUG_ON(!local);
86	return local->dev;
87}
88
89struct vport *ovs_netdev_link(struct vport *vport, const char *name)
90{
91	int err;
92
93	vport->dev = dev_get_by_name(ovs_dp_get_net(vport->dp), name);
94	if (!vport->dev) {
95		err = -ENODEV;
96		goto error_free_vport;
97	}
98
99	if (vport->dev->flags & IFF_LOOPBACK ||
100	    vport->dev->type != ARPHRD_ETHER ||
101	    ovs_is_internal_dev(vport->dev)) {
102		err = -EINVAL;
103		goto error_put;
104	}
105
106	rtnl_lock();
107	err = netdev_master_upper_dev_link(vport->dev,
108					   get_dpdev(vport->dp));
109	if (err)
110		goto error_unlock;
111
112	err = netdev_rx_handler_register(vport->dev, netdev_frame_hook,
113					 vport);
114	if (err)
115		goto error_master_upper_dev_unlink;
116
117	dev_disable_lro(vport->dev);
118	dev_set_promiscuity(vport->dev, 1);
119	vport->dev->priv_flags |= IFF_OVS_DATAPATH;
120	rtnl_unlock();
121
122	return vport;
123
124error_master_upper_dev_unlink:
125	netdev_upper_dev_unlink(vport->dev, get_dpdev(vport->dp));
126error_unlock:
127	rtnl_unlock();
128error_put:
129	dev_put(vport->dev);
130error_free_vport:
131	ovs_vport_free(vport);
132	return ERR_PTR(err);
133}
134EXPORT_SYMBOL_GPL(ovs_netdev_link);
135
136static struct vport *netdev_create(const struct vport_parms *parms)
137{
138	struct vport *vport;
139
140	vport = ovs_vport_alloc(0, &ovs_netdev_vport_ops, parms);
141	if (IS_ERR(vport))
142		return vport;
143
144	return ovs_netdev_link(vport, parms->name);
145}
146
147static void vport_netdev_free(struct rcu_head *rcu)
148{
149	struct vport *vport = container_of(rcu, struct vport, rcu);
150
151	if (vport->dev)
152		dev_put(vport->dev);
153	ovs_vport_free(vport);
154}
155
156void ovs_netdev_detach_dev(struct vport *vport)
157{
158	ASSERT_RTNL();
159	vport->dev->priv_flags &= ~IFF_OVS_DATAPATH;
160	netdev_rx_handler_unregister(vport->dev);
161	netdev_upper_dev_unlink(vport->dev,
162				netdev_master_upper_dev_get(vport->dev));
163	dev_set_promiscuity(vport->dev, -1);
164}
165EXPORT_SYMBOL_GPL(ovs_netdev_detach_dev);
166
167static void netdev_destroy(struct vport *vport)
168{
169	rtnl_lock();
170	if (vport->dev->priv_flags & IFF_OVS_DATAPATH)
171		ovs_netdev_detach_dev(vport);
172	rtnl_unlock();
173
174	call_rcu(&vport->rcu, vport_netdev_free);
175}
176
177void ovs_netdev_tunnel_destroy(struct vport *vport)
178{
179	rtnl_lock();
180	if (vport->dev->priv_flags & IFF_OVS_DATAPATH)
181		ovs_netdev_detach_dev(vport);
182
183	/* We can be invoked by both explicit vport deletion and
184	 * underlying netdev deregistration; delete the link only
185	 * if it's not already shutting down.
186	 */
187	if (vport->dev->reg_state == NETREG_REGISTERED)
188		rtnl_delete_link(vport->dev);
189	dev_put(vport->dev);
190	vport->dev = NULL;
191	rtnl_unlock();
192
193	call_rcu(&vport->rcu, vport_netdev_free);
194}
195EXPORT_SYMBOL_GPL(ovs_netdev_tunnel_destroy);
196
197/* Returns null if this device is not attached to a datapath. */
198struct vport *ovs_netdev_get_vport(struct net_device *dev)
199{
200	if (likely(dev->priv_flags & IFF_OVS_DATAPATH))
201		return (struct vport *)
202			rcu_dereference_rtnl(dev->rx_handler_data);
203	else
204		return NULL;
205}
206
207static struct vport_ops ovs_netdev_vport_ops = {
208	.type		= OVS_VPORT_TYPE_NETDEV,
209	.create		= netdev_create,
210	.destroy	= netdev_destroy,
211	.send		= dev_queue_xmit,
212};
213
214int __init ovs_netdev_init(void)
215{
216	return ovs_vport_ops_register(&ovs_netdev_vport_ops);
217}
218
219void ovs_netdev_exit(void)
220{
221	ovs_vport_ops_unregister(&ovs_netdev_vport_ops);
222}
223