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 	skb_push(skb, ETH_HLEN);
61 	ovs_skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
62 	ovs_vport_receive(vport, skb, skb_tunnel_info(skb));
63 	return;
64 error:
65 	kfree_skb(skb);
66 }
67 
68 /* Called with rcu_read_lock and bottom-halves disabled. */
69 static 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 
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 local->dev;
87 }
88 
89 struct 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 
124 error_master_upper_dev_unlink:
125 	netdev_upper_dev_unlink(vport->dev, get_dpdev(vport->dp));
126 error_unlock:
127 	rtnl_unlock();
128 error_put:
129 	dev_put(vport->dev);
130 error_free_vport:
131 	ovs_vport_free(vport);
132 	return ERR_PTR(err);
133 }
134 EXPORT_SYMBOL_GPL(ovs_netdev_link);
135 
136 static 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 
147 static 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 
156 void 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 }
165 EXPORT_SYMBOL_GPL(ovs_netdev_detach_dev);
166 
167 static 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 
177 void 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 }
195 EXPORT_SYMBOL_GPL(ovs_netdev_tunnel_destroy);
196 
197 /* Returns null if this device is not attached to a datapath. */
198 struct 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 
207 static 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 
214 int __init ovs_netdev_init(void)
215 {
216 	return ovs_vport_ops_register(&ovs_netdev_vport_ops);
217 }
218 
219 void ovs_netdev_exit(void)
220 {
221 	ovs_vport_ops_unregister(&ovs_netdev_vport_ops);
222 }
223