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 /* Must be called with rcu_read_lock. */
  37 static void netdev_port_receive(struct vport *vport, struct sk_buff *skb)
  38 {
  39         if (unlikely(!vport))
  40                 goto error;
  41
  42         if (unlikely(skb_warn_if_lro(skb)))
  43                 goto error;
  44
  45         /* Make our own copy of the packet.  Otherwise we will mangle the
  46          * packet for anyone who came before us (e.g. tcpdump via AF_PACKET).
  47          */
  48         skb = skb_share_check(skb, GFP_ATOMIC);
  49         if (unlikely(!skb))
  50                 return;
  51
  52         skb_push(skb, ETH_HLEN);
  53         ovs_skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
  54
  55         ovs_vport_receive(vport, skb, NULL);
  56         return;
  57
  58 error:
  59         kfree_skb(skb);
  60 }
  61
  62 /* Called with rcu_read_lock and bottom-halves disabled. */
  63 static rx_handler_result_t netdev_frame_hook(struct sk_buff **pskb)
  64 {
  65         struct sk_buff *skb = *pskb;
  66         struct vport *vport;
  67
  68         if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
  69                 return RX_HANDLER_PASS;
  70
  71         vport = ovs_netdev_get_vport(skb->dev);
  72
  73         netdev_port_receive(vport, skb);
  74
  75         return RX_HANDLER_CONSUMED;
  76 }
  77
  78 static struct net_device *get_dpdev(struct datapath *dp)
  79 {
  80         struct vport *local;
  81
  82         local = ovs_vport_ovsl(dp, OVSP_LOCAL);
  83         BUG_ON(!local);
  84         return netdev_vport_priv(local)->dev;
  85 }
  86
  87 static struct vport *netdev_create(const struct vport_parms *parms)
  88 {
  89         struct vport *vport;
  90         struct netdev_vport *netdev_vport;
  91         int err;
  92
  93         vport = ovs_vport_alloc(sizeof(struct netdev_vport),
  94                                 &ovs_netdev_vport_ops, parms);
  95         if (IS_ERR(vport)) {
  96                 err = PTR_ERR(vport);
  97                 goto error;
  98         }
  99
 100         netdev_vport = netdev_vport_priv(vport);
 101
 102         netdev_vport->dev = dev_get_by_name(ovs_dp_get_net(vport->dp), parms->name);
 103         if (!netdev_vport->dev) {
 104                 err = -ENODEV;
 105                 goto error_free_vport;
 106         }
 107
 108         if (netdev_vport->dev->flags & IFF_LOOPBACK ||
 109             netdev_vport->dev->type != ARPHRD_ETHER ||
 110             ovs_is_internal_dev(netdev_vport->dev)) {
 111                 err = -EINVAL;
 112                 goto error_put;
 113         }
 114
 115         rtnl_lock();
 116         err = netdev_master_upper_dev_link(netdev_vport->dev,
 117                                            get_dpdev(vport->dp));
 118         if (err)
 119                 goto error_unlock;
 120
 121         err = netdev_rx_handler_register(netdev_vport->dev, netdev_frame_hook,
 122                                          vport);
 123         if (err)
 124                 goto error_master_upper_dev_unlink;
 125
 126         dev_set_promiscuity(netdev_vport->dev, 1);
 127         netdev_vport->dev->priv_flags |= IFF_OVS_DATAPATH;
 128         rtnl_unlock();
 129
 130         return vport;
 131
 132 error_master_upper_dev_unlink:
 133         netdev_upper_dev_unlink(netdev_vport->dev, get_dpdev(vport->dp));
 134 error_unlock:
 135         rtnl_unlock();
 136 error_put:
 137         dev_put(netdev_vport->dev);
 138 error_free_vport:
 139         ovs_vport_free(vport);
 140 error:
 141         return ERR_PTR(err);
 142 }
 143
 144 static void free_port_rcu(struct rcu_head *rcu)
 145 {
 146         struct netdev_vport *netdev_vport = container_of(rcu,
 147                                         struct netdev_vport, rcu);
 148
 149         dev_put(netdev_vport->dev);
 150         ovs_vport_free(vport_from_priv(netdev_vport));
 151 }
 152
 153 void ovs_netdev_detach_dev(struct vport *vport)
 154 {
 155         struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
 156
 157         ASSERT_RTNL();
 158         netdev_vport->dev->priv_flags &= ~IFF_OVS_DATAPATH;
 159         netdev_rx_handler_unregister(netdev_vport->dev);
 160         netdev_upper_dev_unlink(netdev_vport->dev,
 161                                 netdev_master_upper_dev_get(netdev_vport->dev));
 162         dev_set_promiscuity(netdev_vport->dev, -1);
 163 }
 164
 165 static void netdev_destroy(struct vport *vport)
 166 {
 167         struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
 168
 169         rtnl_lock();
 170         if (netdev_vport->dev->priv_flags & IFF_OVS_DATAPATH)
 171                 ovs_netdev_detach_dev(vport);
 172         rtnl_unlock();
 173
 174         call_rcu(&netdev_vport->rcu, free_port_rcu);
 175 }
 176
 177 const char *ovs_netdev_get_name(const struct vport *vport)
 178 {
 179         const struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
 180         return netdev_vport->dev->name;
 181 }
 182
 183 static unsigned int packet_length(const struct sk_buff *skb)
 184 {
 185         unsigned int length = skb->len - ETH_HLEN;
 186
 187         if (skb->protocol == htons(ETH_P_8021Q))
 188                 length -= VLAN_HLEN;
 189
 190         return length;
 191 }
 192
 193 static int netdev_send(struct vport *vport, struct sk_buff *skb)
 194 {
 195         struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
 196         int mtu = netdev_vport->dev->mtu;
 197         int len;
 198
 199         if (unlikely(packet_length(skb) > mtu && !skb_is_gso(skb))) {
 200                 net_warn_ratelimited("%s: dropped over-mtu packet: %d > %d\n",
 201                                      netdev_vport->dev->name,
 202                                      packet_length(skb), mtu);
 203                 goto drop;
 204         }
 205
 206         skb->dev = netdev_vport->dev;
 207         len = skb->len;
 208         dev_queue_xmit(skb);
 209
 210         return len;
 211
 212 drop:
 213         kfree_skb(skb);
 214         return 0;
 215 }
 216
 217 /* Returns null if this device is not attached to a datapath. */
 218 struct vport *ovs_netdev_get_vport(struct net_device *dev)
 219 {
 220         if (likely(dev->priv_flags & IFF_OVS_DATAPATH))
 221                 return (struct vport *)
 222                         rcu_dereference_rtnl(dev->rx_handler_data);
 223         else
 224                 return NULL;
 225 }
 226
 227 const struct vport_ops ovs_netdev_vport_ops = {
 228         .type           = OVS_VPORT_TYPE_NETDEV,
 229         .create         = netdev_create,
 230         .destroy        = netdev_destroy,
 231         .get_name       = ovs_netdev_get_name,
 232         .send           = netdev_send,
 233 };