net/openvswitch/vport-netdev.c

   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 local->dev;
  87 }
  88
  89 static struct vport *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
 135 static struct vport *netdev_create(const struct vport_parms *parms)
 136 {
 137         struct vport *vport;
 138
 139         vport = ovs_vport_alloc(0, &ovs_netdev_vport_ops, parms);
 140         if (IS_ERR(vport))
 141                 return vport;
 142
 143         return netdev_link(vport, parms->name);
 144 }
 145
 146 static void free_port_rcu(struct rcu_head *rcu)
 147 {
 148         struct vport *vport = container_of(rcu, struct vport, rcu);
 149
 150         dev_put(vport->dev);
 151         ovs_vport_free(vport);
 152 }
 153
 154 void ovs_netdev_detach_dev(struct vport *vport)
 155 {
 156         ASSERT_RTNL();
 157         vport->dev->priv_flags &= ~IFF_OVS_DATAPATH;
 158         netdev_rx_handler_unregister(vport->dev);
 159         netdev_upper_dev_unlink(vport->dev,
 160                                 netdev_master_upper_dev_get(vport->dev));
 161         dev_set_promiscuity(vport->dev, -1);
 162 }
 163
 164 static void netdev_destroy(struct vport *vport)
 165 {
 166         rtnl_lock();
 167         if (vport->dev->priv_flags & IFF_OVS_DATAPATH)
 168                 ovs_netdev_detach_dev(vport);
 169         rtnl_unlock();
 170
 171         call_rcu(&vport->rcu, free_port_rcu);
 172 }
 173
 174 static unsigned int packet_length(const struct sk_buff *skb)
 175 {
 176         unsigned int length = skb->len - ETH_HLEN;
 177
 178         if (skb->protocol == htons(ETH_P_8021Q))
 179                 length -= VLAN_HLEN;
 180
 181         return length;
 182 }
 183
 184 static int netdev_send(struct vport *vport, struct sk_buff *skb)
 185 {
 186         int mtu = vport->dev->mtu;
 187         int len;
 188
 189         if (unlikely(packet_length(skb) > mtu && !skb_is_gso(skb))) {
 190                 net_warn_ratelimited("%s: dropped over-mtu packet: %d > %d\n",
 191                                      vport->dev->name,
 192                                      packet_length(skb), mtu);
 193                 goto drop;
 194         }
 195
 196         skb->dev = vport->dev;
 197         len = skb->len;
 198         dev_queue_xmit(skb);
 199
 200         return len;
 201
 202 drop:
 203         kfree_skb(skb);
 204         return 0;
 205 }
 206
 207 /* Returns null if this device is not attached to a datapath. */
 208 struct vport *ovs_netdev_get_vport(struct net_device *dev)
 209 {
 210         if (likely(dev->priv_flags & IFF_OVS_DATAPATH))
 211                 return (struct vport *)
 212                         rcu_dereference_rtnl(dev->rx_handler_data);
 213         else
 214                 return NULL;
 215 }
 216
 217 static struct vport_ops ovs_netdev_vport_ops = {
 218         .type           = OVS_VPORT_TYPE_NETDEV,
 219         .create         = netdev_create,
 220         .destroy        = netdev_destroy,
 221         .send           = netdev_send,
 222 };
 223
 224 int __init ovs_netdev_init(void)
 225 {
 226         return ovs_vport_ops_register(&ovs_netdev_vport_ops);
 227 }
 228
 229 void ovs_netdev_exit(void)
 230 {
 231         ovs_vport_ops_unregister(&ovs_netdev_vport_ops);
 232 }