1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2007-2012 Nicira, Inc.
4  */
5 
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7 
8 #include <linux/if_arp.h>
9 #include <linux/if_bridge.h>
10 #include <linux/if_vlan.h>
11 #include <linux/kernel.h>
12 #include <linux/llc.h>
13 #include <linux/rtnetlink.h>
14 #include <linux/skbuff.h>
15 #include <linux/openvswitch.h>
16 #include <linux/export.h>
17 
18 #include <net/ip_tunnels.h>
19 #include <net/rtnetlink.h>
20 
21 #include "datapath.h"
22 #include "vport.h"
23 #include "vport-internal_dev.h"
24 #include "vport-netdev.h"
25 
26 static struct vport_ops ovs_netdev_vport_ops;
27 
28 /* Must be called with rcu_read_lock. */
29 static void netdev_port_receive(struct sk_buff *skb)
30 {
31 	struct vport *vport;
32 
33 	vport = ovs_netdev_get_vport(skb->dev);
34 	if (unlikely(!vport))
35 		goto error;
36 
37 	if (unlikely(skb_warn_if_lro(skb)))
38 		goto error;
39 
40 	/* Make our own copy of the packet.  Otherwise we will mangle the
41 	 * packet for anyone who came before us (e.g. tcpdump via AF_PACKET).
42 	 */
43 	skb = skb_share_check(skb, GFP_ATOMIC);
44 	if (unlikely(!skb))
45 		return;
46 
47 	if (skb->dev->type == ARPHRD_ETHER) {
48 		skb_push(skb, ETH_HLEN);
49 		skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
50 	}
51 	ovs_vport_receive(vport, skb, skb_tunnel_info(skb));
52 	return;
53 error:
54 	kfree_skb(skb);
55 }
56 
57 /* Called with rcu_read_lock and bottom-halves disabled. */
58 static rx_handler_result_t netdev_frame_hook(struct sk_buff **pskb)
59 {
60 	struct sk_buff *skb = *pskb;
61 
62 	if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
63 		return RX_HANDLER_PASS;
64 
65 	netdev_port_receive(skb);
66 	return RX_HANDLER_CONSUMED;
67 }
68 
69 static struct net_device *get_dpdev(const struct datapath *dp)
70 {
71 	struct vport *local;
72 
73 	local = ovs_vport_ovsl(dp, OVSP_LOCAL);
74 	return local->dev;
75 }
76 
77 struct vport *ovs_netdev_link(struct vport *vport, const char *name)
78 {
79 	int err;
80 
81 	vport->dev = dev_get_by_name(ovs_dp_get_net(vport->dp), name);
82 	if (!vport->dev) {
83 		err = -ENODEV;
84 		goto error_free_vport;
85 	}
86 
87 	if (vport->dev->flags & IFF_LOOPBACK ||
88 	    (vport->dev->type != ARPHRD_ETHER &&
89 	     vport->dev->type != ARPHRD_NONE) ||
90 	    ovs_is_internal_dev(vport->dev)) {
91 		err = -EINVAL;
92 		goto error_put;
93 	}
94 
95 	rtnl_lock();
96 	err = netdev_master_upper_dev_link(vport->dev,
97 					   get_dpdev(vport->dp),
98 					   NULL, NULL, NULL);
99 	if (err)
100 		goto error_unlock;
101 
102 	err = netdev_rx_handler_register(vport->dev, netdev_frame_hook,
103 					 vport);
104 	if (err)
105 		goto error_master_upper_dev_unlink;
106 
107 	dev_disable_lro(vport->dev);
108 	dev_set_promiscuity(vport->dev, 1);
109 	vport->dev->priv_flags |= IFF_OVS_DATAPATH;
110 	rtnl_unlock();
111 
112 	return vport;
113 
114 error_master_upper_dev_unlink:
115 	netdev_upper_dev_unlink(vport->dev, get_dpdev(vport->dp));
116 error_unlock:
117 	rtnl_unlock();
118 error_put:
119 	dev_put(vport->dev);
120 error_free_vport:
121 	ovs_vport_free(vport);
122 	return ERR_PTR(err);
123 }
124 EXPORT_SYMBOL_GPL(ovs_netdev_link);
125 
126 static struct vport *netdev_create(const struct vport_parms *parms)
127 {
128 	struct vport *vport;
129 
130 	vport = ovs_vport_alloc(0, &ovs_netdev_vport_ops, parms);
131 	if (IS_ERR(vport))
132 		return vport;
133 
134 	return ovs_netdev_link(vport, parms->name);
135 }
136 
137 static void vport_netdev_free(struct rcu_head *rcu)
138 {
139 	struct vport *vport = container_of(rcu, struct vport, rcu);
140 
141 	if (vport->dev)
142 		dev_put(vport->dev);
143 	ovs_vport_free(vport);
144 }
145 
146 void ovs_netdev_detach_dev(struct vport *vport)
147 {
148 	ASSERT_RTNL();
149 	vport->dev->priv_flags &= ~IFF_OVS_DATAPATH;
150 	netdev_rx_handler_unregister(vport->dev);
151 	netdev_upper_dev_unlink(vport->dev,
152 				netdev_master_upper_dev_get(vport->dev));
153 	dev_set_promiscuity(vport->dev, -1);
154 }
155 
156 static void netdev_destroy(struct vport *vport)
157 {
158 	rtnl_lock();
159 	if (vport->dev->priv_flags & IFF_OVS_DATAPATH)
160 		ovs_netdev_detach_dev(vport);
161 	rtnl_unlock();
162 
163 	call_rcu(&vport->rcu, vport_netdev_free);
164 }
165 
166 void ovs_netdev_tunnel_destroy(struct vport *vport)
167 {
168 	rtnl_lock();
169 	if (vport->dev->priv_flags & IFF_OVS_DATAPATH)
170 		ovs_netdev_detach_dev(vport);
171 
172 	/* We can be invoked by both explicit vport deletion and
173 	 * underlying netdev deregistration; delete the link only
174 	 * if it's not already shutting down.
175 	 */
176 	if (vport->dev->reg_state == NETREG_REGISTERED)
177 		rtnl_delete_link(vport->dev);
178 	dev_put(vport->dev);
179 	vport->dev = NULL;
180 	rtnl_unlock();
181 
182 	call_rcu(&vport->rcu, vport_netdev_free);
183 }
184 EXPORT_SYMBOL_GPL(ovs_netdev_tunnel_destroy);
185 
186 /* Returns null if this device is not attached to a datapath. */
187 struct vport *ovs_netdev_get_vport(struct net_device *dev)
188 {
189 	if (likely(dev->priv_flags & IFF_OVS_DATAPATH))
190 		return (struct vport *)
191 			rcu_dereference_rtnl(dev->rx_handler_data);
192 	else
193 		return NULL;
194 }
195 
196 static struct vport_ops ovs_netdev_vport_ops = {
197 	.type		= OVS_VPORT_TYPE_NETDEV,
198 	.create		= netdev_create,
199 	.destroy	= netdev_destroy,
200 	.send		= dev_queue_xmit,
201 };
202 
203 int __init ovs_netdev_init(void)
204 {
205 	return ovs_vport_ops_register(&ovs_netdev_vport_ops);
206 }
207 
208 void ovs_netdev_exit(void)
209 {
210 	ovs_vport_ops_unregister(&ovs_netdev_vport_ops);
211 }
212