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
30#include <net/llc.h>
31
32#include "datapath.h"
33#include "vport-internal_dev.h"
34#include "vport-netdev.h"
35
36static struct vport_ops ovs_netdev_vport_ops;
37
38/* Must be called with rcu_read_lock. */
39static void netdev_port_receive(struct vport *vport, struct sk_buff *skb)
40{
41	if (unlikely(!vport))
42		goto error;
43
44	if (unlikely(skb_warn_if_lro(skb)))
45		goto error;
46
47	/* Make our own copy of the packet.  Otherwise we will mangle the
48	 * packet for anyone who came before us (e.g. tcpdump via AF_PACKET).
49	 */
50	skb = skb_share_check(skb, GFP_ATOMIC);
51	if (unlikely(!skb))
52		return;
53
54	skb_push(skb, ETH_HLEN);
55	ovs_skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
56
57	ovs_vport_receive(vport, skb, NULL);
58	return;
59
60error:
61	kfree_skb(skb);
62}
63
64/* Called with rcu_read_lock and bottom-halves disabled. */
65static rx_handler_result_t netdev_frame_hook(struct sk_buff **pskb)
66{
67	struct sk_buff *skb = *pskb;
68	struct vport *vport;
69
70	if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
71		return RX_HANDLER_PASS;
72
73	vport = ovs_netdev_get_vport(skb->dev);
74
75	netdev_port_receive(vport, skb);
76
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 netdev_vport_priv(local)->dev;
87}
88
89static struct vport *netdev_create(const struct vport_parms *parms)
90{
91	struct vport *vport;
92	struct netdev_vport *netdev_vport;
93	int err;
94
95	vport = ovs_vport_alloc(sizeof(struct netdev_vport),
96				&ovs_netdev_vport_ops, parms);
97	if (IS_ERR(vport)) {
98		err = PTR_ERR(vport);
99		goto error;
100	}
101
102	netdev_vport = netdev_vport_priv(vport);
103
104	netdev_vport->dev = dev_get_by_name(ovs_dp_get_net(vport->dp), parms->name);
105	if (!netdev_vport->dev) {
106		err = -ENODEV;
107		goto error_free_vport;
108	}
109
110	if (netdev_vport->dev->flags & IFF_LOOPBACK ||
111	    netdev_vport->dev->type != ARPHRD_ETHER ||
112	    ovs_is_internal_dev(netdev_vport->dev)) {
113		err = -EINVAL;
114		goto error_put;
115	}
116
117	rtnl_lock();
118	err = netdev_master_upper_dev_link(netdev_vport->dev,
119					   get_dpdev(vport->dp));
120	if (err)
121		goto error_unlock;
122
123	err = netdev_rx_handler_register(netdev_vport->dev, netdev_frame_hook,
124					 vport);
125	if (err)
126		goto error_master_upper_dev_unlink;
127
128	dev_disable_lro(netdev_vport->dev);
129	dev_set_promiscuity(netdev_vport->dev, 1);
130	netdev_vport->dev->priv_flags |= IFF_OVS_DATAPATH;
131	rtnl_unlock();
132
133	return vport;
134
135error_master_upper_dev_unlink:
136	netdev_upper_dev_unlink(netdev_vport->dev, get_dpdev(vport->dp));
137error_unlock:
138	rtnl_unlock();
139error_put:
140	dev_put(netdev_vport->dev);
141error_free_vport:
142	ovs_vport_free(vport);
143error:
144	return ERR_PTR(err);
145}
146
147static void free_port_rcu(struct rcu_head *rcu)
148{
149	struct netdev_vport *netdev_vport = container_of(rcu,
150					struct netdev_vport, rcu);
151
152	dev_put(netdev_vport->dev);
153	ovs_vport_free(vport_from_priv(netdev_vport));
154}
155
156void ovs_netdev_detach_dev(struct vport *vport)
157{
158	struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
159
160	ASSERT_RTNL();
161	netdev_vport->dev->priv_flags &= ~IFF_OVS_DATAPATH;
162	netdev_rx_handler_unregister(netdev_vport->dev);
163	netdev_upper_dev_unlink(netdev_vport->dev,
164				netdev_master_upper_dev_get(netdev_vport->dev));
165	dev_set_promiscuity(netdev_vport->dev, -1);
166}
167
168static void netdev_destroy(struct vport *vport)
169{
170	struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
171
172	rtnl_lock();
173	if (netdev_vport->dev->priv_flags & IFF_OVS_DATAPATH)
174		ovs_netdev_detach_dev(vport);
175	rtnl_unlock();
176
177	call_rcu(&netdev_vport->rcu, free_port_rcu);
178}
179
180const char *ovs_netdev_get_name(const struct vport *vport)
181{
182	const struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
183	return netdev_vport->dev->name;
184}
185
186static unsigned int packet_length(const struct sk_buff *skb)
187{
188	unsigned int length = skb->len - ETH_HLEN;
189
190	if (skb->protocol == htons(ETH_P_8021Q))
191		length -= VLAN_HLEN;
192
193	return length;
194}
195
196static int netdev_send(struct vport *vport, struct sk_buff *skb)
197{
198	struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
199	int mtu = netdev_vport->dev->mtu;
200	int len;
201
202	if (unlikely(packet_length(skb) > mtu && !skb_is_gso(skb))) {
203		net_warn_ratelimited("%s: dropped over-mtu packet: %d > %d\n",
204				     netdev_vport->dev->name,
205				     packet_length(skb), mtu);
206		goto drop;
207	}
208
209	skb->dev = netdev_vport->dev;
210	len = skb->len;
211	dev_queue_xmit(skb);
212
213	return len;
214
215drop:
216	kfree_skb(skb);
217	return 0;
218}
219
220/* Returns null if this device is not attached to a datapath. */
221struct vport *ovs_netdev_get_vport(struct net_device *dev)
222{
223	if (likely(dev->priv_flags & IFF_OVS_DATAPATH))
224		return (struct vport *)
225			rcu_dereference_rtnl(dev->rx_handler_data);
226	else
227		return NULL;
228}
229
230static struct vport_ops ovs_netdev_vport_ops = {
231	.type		= OVS_VPORT_TYPE_NETDEV,
232	.create		= netdev_create,
233	.destroy	= netdev_destroy,
234	.get_name	= ovs_netdev_get_name,
235	.send		= netdev_send,
236};
237
238int __init ovs_netdev_init(void)
239{
240	return ovs_vport_ops_register(&ovs_netdev_vport_ops);
241}
242
243void ovs_netdev_exit(void)
244{
245	ovs_vport_ops_unregister(&ovs_netdev_vport_ops);
246}
247