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vport-netdev.c
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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 
29 #include <net/llc.h>
30 
31 #include "datapath.h"
32 #include "vport-internal_dev.h"
33 #include "vport-netdev.h"
34 
35 /* Must be called with rcu_read_lock. */
36 static void netdev_port_receive(struct vport *vport, struct sk_buff *skb)
37 {
38  if (unlikely(!vport)) {
39  kfree_skb(skb);
40  return;
41  }
42 
43  /* Make our own copy of the packet. Otherwise we will mangle the
44  * packet for anyone who came before us (e.g. tcpdump via AF_PACKET).
45  * (No one comes after us, since we tell handle_bridge() that we took
46  * the packet.) */
47  skb = skb_share_check(skb, GFP_ATOMIC);
48  if (unlikely(!skb))
49  return;
50 
51  skb_push(skb, ETH_HLEN);
52  ovs_vport_receive(vport, skb);
53 }
54 
55 /* Called with rcu_read_lock and bottom-halves disabled. */
56 static rx_handler_result_t netdev_frame_hook(struct sk_buff **pskb)
57 {
58  struct sk_buff *skb = *pskb;
59  struct vport *vport;
60 
61  if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
62  return RX_HANDLER_PASS;
63 
64  vport = ovs_netdev_get_vport(skb->dev);
65 
66  netdev_port_receive(vport, skb);
67 
68  return RX_HANDLER_CONSUMED;
69 }
70 
71 static struct vport *netdev_create(const struct vport_parms *parms)
72 {
73  struct vport *vport;
74  struct netdev_vport *netdev_vport;
75  int err;
76 
77  vport = ovs_vport_alloc(sizeof(struct netdev_vport),
78  &ovs_netdev_vport_ops, parms);
79  if (IS_ERR(vport)) {
80  err = PTR_ERR(vport);
81  goto error;
82  }
83 
84  netdev_vport = netdev_vport_priv(vport);
85 
86  netdev_vport->dev = dev_get_by_name(ovs_dp_get_net(vport->dp), parms->name);
87  if (!netdev_vport->dev) {
88  err = -ENODEV;
89  goto error_free_vport;
90  }
91 
92  if (netdev_vport->dev->flags & IFF_LOOPBACK ||
93  netdev_vport->dev->type != ARPHRD_ETHER ||
94  ovs_is_internal_dev(netdev_vport->dev)) {
95  err = -EINVAL;
96  goto error_put;
97  }
98 
99  err = netdev_rx_handler_register(netdev_vport->dev, netdev_frame_hook,
100  vport);
101  if (err)
102  goto error_put;
103 
104  dev_set_promiscuity(netdev_vport->dev, 1);
105  netdev_vport->dev->priv_flags |= IFF_OVS_DATAPATH;
106 
107  return vport;
108 
109 error_put:
110  dev_put(netdev_vport->dev);
111 error_free_vport:
112  ovs_vport_free(vport);
113 error:
114  return ERR_PTR(err);
115 }
116 
117 static void netdev_destroy(struct vport *vport)
118 {
119  struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
120 
121  netdev_vport->dev->priv_flags &= ~IFF_OVS_DATAPATH;
122  netdev_rx_handler_unregister(netdev_vport->dev);
123  dev_set_promiscuity(netdev_vport->dev, -1);
124 
125  synchronize_rcu();
126 
127  dev_put(netdev_vport->dev);
128  ovs_vport_free(vport);
129 }
130 
131 const char *ovs_netdev_get_name(const struct vport *vport)
132 {
133  const struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
134  return netdev_vport->dev->name;
135 }
136 
137 int ovs_netdev_get_ifindex(const struct vport *vport)
138 {
139  const struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
140  return netdev_vport->dev->ifindex;
141 }
142 
143 static unsigned int packet_length(const struct sk_buff *skb)
144 {
145  unsigned int length = skb->len - ETH_HLEN;
146 
147  if (skb->protocol == htons(ETH_P_8021Q))
148  length -= VLAN_HLEN;
149 
150  return length;
151 }
152 
153 static int netdev_send(struct vport *vport, struct sk_buff *skb)
154 {
155  struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
156  int mtu = netdev_vport->dev->mtu;
157  int len;
158 
159  if (unlikely(packet_length(skb) > mtu && !skb_is_gso(skb))) {
160  net_warn_ratelimited("%s: dropped over-mtu packet: %d > %d\n",
161  netdev_vport->dev->name,
162  packet_length(skb), mtu);
163  goto error;
164  }
165 
166  if (unlikely(skb_warn_if_lro(skb)))
167  goto error;
168 
169  skb->dev = netdev_vport->dev;
170  len = skb->len;
171  dev_queue_xmit(skb);
172 
173  return len;
174 
175 error:
176  kfree_skb(skb);
178  return 0;
179 }
180 
181 /* Returns null if this device is not attached to a datapath. */
182 struct vport *ovs_netdev_get_vport(struct net_device *dev)
183 {
184  if (likely(dev->priv_flags & IFF_OVS_DATAPATH))
185  return (struct vport *)
187  else
188  return NULL;
189 }
190 
192  .type = OVS_VPORT_TYPE_NETDEV,
193  .create = netdev_create,
194  .destroy = netdev_destroy,
195  .get_name = ovs_netdev_get_name,
196  .get_ifindex = ovs_netdev_get_ifindex,
197  .send = netdev_send,
198 };