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 
39 static struct vport_ops ovs_netdev_vport_ops;
40 
41 /* Must be called with rcu_read_lock. */
42 static 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;
66 error:
67 	kfree_skb(skb);
68 }
69 
70 /* Called with rcu_read_lock and bottom-halves disabled. */
71 static 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 
82 static 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 
91 struct 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 
127 error_master_upper_dev_unlink:
128 	netdev_upper_dev_unlink(vport->dev, get_dpdev(vport->dp));
129 error_unlock:
130 	rtnl_unlock();
131 error_put:
132 	dev_put(vport->dev);
133 error_free_vport:
134 	ovs_vport_free(vport);
135 	return ERR_PTR(err);
136 }
137 EXPORT_SYMBOL_GPL(ovs_netdev_link);
138 
139 static 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 
150 static 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 
159 void 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 
169 static 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 
179 void 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 }
197 EXPORT_SYMBOL_GPL(ovs_netdev_tunnel_destroy);
198 
199 /* Returns null if this device is not attached to a datapath. */
200 struct 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 
209 static 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 
216 int __init ovs_netdev_init(void)
217 {
218 	return ovs_vport_ops_register(&ovs_netdev_vport_ops);
219 }
220 
221 void ovs_netdev_exit(void)
222 {
223 	ovs_vport_ops_unregister(&ovs_netdev_vport_ops);
224 }
225