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