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