net/openvswitch/vport-netdev.c

   1 /*
   2  * Copyright (c) 2007-2011 Nicira Networks.
   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                 kfree_skb(skb);
  40                 return;
  41         }
  42
  43         /* Make our own copy of the packet.  Otherwise we will mangle the
  44          * packet for anyone who came before us (e.g. tcpdump via AF_PACKET).
  45          * (No one comes after us, since we tell handle_bridge() that we took
  46          * the packet.) */
  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 }
  54
  55 /* Called with rcu_read_lock and bottom-halves disabled. */
  56 static rx_handler_result_t netdev_frame_hook(struct sk_buff **pskb)
  57 {
  58         struct sk_buff *skb = *pskb;
  59         struct vport *vport;
  60
  61         if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
  62                 return RX_HANDLER_PASS;
  63
  64         vport = ovs_netdev_get_vport(skb->dev);
  65
  66         netdev_port_receive(vport, skb);
  67
  68         return RX_HANDLER_CONSUMED;
  69 }
  70
  71 static struct vport *netdev_create(const struct vport_parms *parms)
  72 {
  73         struct vport *vport;
  74         struct netdev_vport *netdev_vport;
  75         int err;
  76
  77         vport = ovs_vport_alloc(sizeof(struct netdev_vport),
  78                                 &ovs_netdev_vport_ops, parms);
  79         if (IS_ERR(vport)) {
  80                 err = PTR_ERR(vport);
  81                 goto error;
  82         }
  83
  84         netdev_vport = netdev_vport_priv(vport);
  85
  86         netdev_vport->dev = dev_get_by_name(&init_net, parms->name);
  87         if (!netdev_vport->dev) {
  88                 err = -ENODEV;
  89                 goto error_free_vport;
  90         }
  91
  92         if (netdev_vport->dev->flags & IFF_LOOPBACK ||
  93             netdev_vport->dev->type != ARPHRD_ETHER ||
  94             ovs_is_internal_dev(netdev_vport->dev)) {
  95                 err = -EINVAL;
  96                 goto error_put;
  97         }
  98
  99         err = netdev_rx_handler_register(netdev_vport->dev, netdev_frame_hook,
 100                                          vport);
 101         if (err)
 102                 goto error_put;
 103
 104         dev_set_promiscuity(netdev_vport->dev, 1);
 105         netdev_vport->dev->priv_flags |= IFF_OVS_DATAPATH;
 106
 107         return vport;
 108
 109 error_put:
 110         dev_put(netdev_vport->dev);
 111 error_free_vport:
 112         ovs_vport_free(vport);
 113 error:
 114         return ERR_PTR(err);
 115 }
 116
 117 static void netdev_destroy(struct vport *vport)
 118 {
 119         struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
 120
 121         netdev_vport->dev->priv_flags &= ~IFF_OVS_DATAPATH;
 122         netdev_rx_handler_unregister(netdev_vport->dev);
 123         dev_set_promiscuity(netdev_vport->dev, -1);
 124
 125         synchronize_rcu();
 126
 127         dev_put(netdev_vport->dev);
 128         ovs_vport_free(vport);
 129 }
 130
 131 const char *ovs_netdev_get_name(const struct vport *vport)
 132 {
 133         const struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
 134         return netdev_vport->dev->name;
 135 }
 136
 137 int ovs_netdev_get_ifindex(const struct vport *vport)
 138 {
 139         const struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
 140         return netdev_vport->dev->ifindex;
 141 }
 142
 143 static unsigned int packet_length(const struct sk_buff *skb)
 144 {
 145         unsigned int length = skb->len - ETH_HLEN;
 146
 147         if (skb->protocol == htons(ETH_P_8021Q))
 148                 length -= VLAN_HLEN;
 149
 150         return length;
 151 }
 152
 153 static int netdev_send(struct vport *vport, struct sk_buff *skb)
 154 {
 155         struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
 156         int mtu = netdev_vport->dev->mtu;
 157         int len;
 158
 159         if (unlikely(packet_length(skb) > mtu && !skb_is_gso(skb))) {
 160                 if (net_ratelimit())
 161                         pr_warn("%s: dropped over-mtu packet: %d > %d\n",
 162                                 ovs_dp_name(vport->dp), packet_length(skb), mtu);
 163                 goto error;
 164         }
 165
 166         if (unlikely(skb_warn_if_lro(skb)))
 167                 goto error;
 168
 169         skb->dev = netdev_vport->dev;
 170         len = skb->len;
 171         dev_queue_xmit(skb);
 172
 173         return len;
 174
 175 error:
 176         kfree_skb(skb);
 177         ovs_vport_record_error(vport, VPORT_E_TX_DROPPED);
 178         return 0;
 179 }
 180
 181 /* Returns null if this device is not attached to a datapath. */
 182 struct vport *ovs_netdev_get_vport(struct net_device *dev)
 183 {
 184         if (likely(dev->priv_flags & IFF_OVS_DATAPATH))
 185                 return (struct vport *)
 186                         rcu_dereference_rtnl(dev->rx_handler_data);
 187         else
 188                 return NULL;
 189 }
 190
 191 const struct vport_ops ovs_netdev_vport_ops = {
 192         .type           = OVS_VPORT_TYPE_NETDEV,
 193         .create         = netdev_create,
 194         .destroy        = netdev_destroy,
 195         .get_name       = ovs_netdev_get_name,
 196         .get_ifindex    = ovs_netdev_get_ifindex,
 197         .send           = netdev_send,
 198 };