xref: /linux/net/openvswitch/vport-netdev.c (revision 93df8a1ed6231727c5db94a80b1a6bd5ee67cec3)
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 
36 static struct vport_ops ovs_netdev_vport_ops;
37 
38 /* Must be called with rcu_read_lock. */
39 static 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 
60 error:
61 	kfree_skb(skb);
62 }
63 
64 /* Called with rcu_read_lock and bottom-halves disabled. */
65 static 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 
80 static 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 
89 static 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 
135 error_master_upper_dev_unlink:
136 	netdev_upper_dev_unlink(netdev_vport->dev, get_dpdev(vport->dp));
137 error_unlock:
138 	rtnl_unlock();
139 error_put:
140 	dev_put(netdev_vport->dev);
141 error_free_vport:
142 	ovs_vport_free(vport);
143 error:
144 	return ERR_PTR(err);
145 }
146 
147 static 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 
156 void 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 
168 static 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 
180 const 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 
186 static 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 
196 static 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 
215 drop:
216 	kfree_skb(skb);
217 	return 0;
218 }
219 
220 /* Returns null if this device is not attached to a datapath. */
221 struct 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 
230 static 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 
238 int __init ovs_netdev_init(void)
239 {
240 	return ovs_vport_ops_register(&ovs_netdev_vport_ops);
241 }
242 
243 void ovs_netdev_exit(void)
244 {
245 	ovs_vport_ops_unregister(&ovs_netdev_vport_ops);
246 }
247