xref: /linux/net/openvswitch/vport-netdev.c (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
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_set_promiscuity(netdev_vport->dev, 1);
129 	netdev_vport->dev->priv_flags |= IFF_OVS_DATAPATH;
130 	rtnl_unlock();
131 
132 	return vport;
133 
134 error_master_upper_dev_unlink:
135 	netdev_upper_dev_unlink(netdev_vport->dev, get_dpdev(vport->dp));
136 error_unlock:
137 	rtnl_unlock();
138 error_put:
139 	dev_put(netdev_vport->dev);
140 error_free_vport:
141 	ovs_vport_free(vport);
142 error:
143 	return ERR_PTR(err);
144 }
145 
146 static void free_port_rcu(struct rcu_head *rcu)
147 {
148 	struct netdev_vport *netdev_vport = container_of(rcu,
149 					struct netdev_vport, rcu);
150 
151 	dev_put(netdev_vport->dev);
152 	ovs_vport_free(vport_from_priv(netdev_vport));
153 }
154 
155 void ovs_netdev_detach_dev(struct vport *vport)
156 {
157 	struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
158 
159 	ASSERT_RTNL();
160 	netdev_vport->dev->priv_flags &= ~IFF_OVS_DATAPATH;
161 	netdev_rx_handler_unregister(netdev_vport->dev);
162 	netdev_upper_dev_unlink(netdev_vport->dev,
163 				netdev_master_upper_dev_get(netdev_vport->dev));
164 	dev_set_promiscuity(netdev_vport->dev, -1);
165 }
166 
167 static void netdev_destroy(struct vport *vport)
168 {
169 	struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
170 
171 	rtnl_lock();
172 	if (netdev_vport->dev->priv_flags & IFF_OVS_DATAPATH)
173 		ovs_netdev_detach_dev(vport);
174 	rtnl_unlock();
175 
176 	call_rcu(&netdev_vport->rcu, free_port_rcu);
177 }
178 
179 const char *ovs_netdev_get_name(const struct vport *vport)
180 {
181 	const struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
182 	return netdev_vport->dev->name;
183 }
184 
185 static unsigned int packet_length(const struct sk_buff *skb)
186 {
187 	unsigned int length = skb->len - ETH_HLEN;
188 
189 	if (skb->protocol == htons(ETH_P_8021Q))
190 		length -= VLAN_HLEN;
191 
192 	return length;
193 }
194 
195 static int netdev_send(struct vport *vport, struct sk_buff *skb)
196 {
197 	struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
198 	int mtu = netdev_vport->dev->mtu;
199 	int len;
200 
201 	if (unlikely(packet_length(skb) > mtu && !skb_is_gso(skb))) {
202 		net_warn_ratelimited("%s: dropped over-mtu packet: %d > %d\n",
203 				     netdev_vport->dev->name,
204 				     packet_length(skb), mtu);
205 		goto drop;
206 	}
207 
208 	skb->dev = netdev_vport->dev;
209 	len = skb->len;
210 	dev_queue_xmit(skb);
211 
212 	return len;
213 
214 drop:
215 	kfree_skb(skb);
216 	return 0;
217 }
218 
219 /* Returns null if this device is not attached to a datapath. */
220 struct vport *ovs_netdev_get_vport(struct net_device *dev)
221 {
222 	if (likely(dev->priv_flags & IFF_OVS_DATAPATH))
223 		return (struct vport *)
224 			rcu_dereference_rtnl(dev->rx_handler_data);
225 	else
226 		return NULL;
227 }
228 
229 static struct vport_ops ovs_netdev_vport_ops = {
230 	.type		= OVS_VPORT_TYPE_NETDEV,
231 	.create		= netdev_create,
232 	.destroy	= netdev_destroy,
233 	.get_name	= ovs_netdev_get_name,
234 	.send		= netdev_send,
235 };
236 
237 int __init ovs_netdev_init(void)
238 {
239 	return ovs_vport_ops_register(&ovs_netdev_vport_ops);
240 }
241 
242 void ovs_netdev_exit(void)
243 {
244 	ovs_vport_ops_unregister(&ovs_netdev_vport_ops);
245 }
246