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          * (No one comes after us, since we tell handle_bridge() that we took
  47          * the packet.) */
  48         skb = skb_share_check(skb, GFP_ATOMIC);
  49         if (unlikely(!skb))
  50                 return;
  51
  52         skb_push(skb, ETH_HLEN);
  53         ovs_vport_receive(vport, skb);
  54         return;
  55
  56 error:
  57         kfree_skb(skb);
  58 }
  59
  60 /* Called with rcu_read_lock and bottom-halves disabled. */
  61 static rx_handler_result_t netdev_frame_hook(struct sk_buff **pskb)
  62 {
  63         struct sk_buff *skb = *pskb;
  64         struct vport *vport;
  65
  66         if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
  67                 return RX_HANDLER_PASS;
  68
  69         vport = ovs_netdev_get_vport(skb->dev);
  70
  71         netdev_port_receive(vport, skb);
  72
  73         return RX_HANDLER_CONSUMED;
  74 }
  75
  76 static struct vport *netdev_create(const struct vport_parms *parms)
  77 {
  78         struct vport *vport;
  79         struct netdev_vport *netdev_vport;
  80         int err;
  81
  82         vport = ovs_vport_alloc(sizeof(struct netdev_vport),
  83                                 &ovs_netdev_vport_ops, parms);
  84         if (IS_ERR(vport)) {
  85                 err = PTR_ERR(vport);
  86                 goto error;
  87         }
  88
  89         netdev_vport = netdev_vport_priv(vport);
  90
  91         netdev_vport->dev = dev_get_by_name(ovs_dp_get_net(vport->dp), parms->name);
  92         if (!netdev_vport->dev) {
  93                 err = -ENODEV;
  94                 goto error_free_vport;
  95         }
  96
  97         if (netdev_vport->dev->flags & IFF_LOOPBACK ||
  98             netdev_vport->dev->type != ARPHRD_ETHER ||
  99             ovs_is_internal_dev(netdev_vport->dev)) {
 100                 err = -EINVAL;
 101                 goto error_put;
 102         }
 103
 104         err = netdev_rx_handler_register(netdev_vport->dev, netdev_frame_hook,
 105                                          vport);
 106         if (err)
 107                 goto error_put;
 108
 109         dev_set_promiscuity(netdev_vport->dev, 1);
 110         netdev_vport->dev->priv_flags |= IFF_OVS_DATAPATH;
 111
 112         return vport;
 113
 114 error_put:
 115         dev_put(netdev_vport->dev);
 116 error_free_vport:
 117         ovs_vport_free(vport);
 118 error:
 119         return ERR_PTR(err);
 120 }
 121
 122 static void free_port_rcu(struct rcu_head *rcu)
 123 {
 124         struct netdev_vport *netdev_vport = container_of(rcu,
 125                                         struct netdev_vport, rcu);
 126
 127         dev_put(netdev_vport->dev);
 128         ovs_vport_free(vport_from_priv(netdev_vport));
 129 }
 130
 131 static void netdev_destroy(struct vport *vport)
 132 {
 133         struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
 134
 135         netdev_vport->dev->priv_flags &= ~IFF_OVS_DATAPATH;
 136         netdev_rx_handler_unregister(netdev_vport->dev);
 137         dev_set_promiscuity(netdev_vport->dev, -1);
 138
 139         call_rcu(&netdev_vport->rcu, free_port_rcu);
 140 }
 141
 142 const char *ovs_netdev_get_name(const struct vport *vport)
 143 {
 144         const struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
 145         return netdev_vport->dev->name;
 146 }
 147
 148 int ovs_netdev_get_ifindex(const struct vport *vport)
 149 {
 150         const struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
 151         return netdev_vport->dev->ifindex;
 152 }
 153
 154 static unsigned int packet_length(const struct sk_buff *skb)
 155 {
 156         unsigned int length = skb->len - ETH_HLEN;
 157
 158         if (skb->protocol == htons(ETH_P_8021Q))
 159                 length -= VLAN_HLEN;
 160
 161         return length;
 162 }
 163
 164 static int netdev_send(struct vport *vport, struct sk_buff *skb)
 165 {
 166         struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
 167         int mtu = netdev_vport->dev->mtu;
 168         int len;
 169
 170         if (unlikely(packet_length(skb) > mtu && !skb_is_gso(skb))) {
 171                 net_warn_ratelimited("%s: dropped over-mtu packet: %d > %d\n",
 172                                      netdev_vport->dev->name,
 173                                      packet_length(skb), mtu);
 174                 goto error;
 175         }
 176
 177         skb->dev = netdev_vport->dev;
 178         len = skb->len;
 179         dev_queue_xmit(skb);
 180
 181         return len;
 182
 183 error:
 184         kfree_skb(skb);
 185         ovs_vport_record_error(vport, VPORT_E_TX_DROPPED);
 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         .get_ifindex    = ovs_netdev_get_ifindex,
 205         .send           = netdev_send,
 206 };