datapath/vport-vxlan.c

   1 /*
   2  * Copyright (c) 2011 Nicira, Inc.
   3  * Copyright (c) 2012 Cisco Systems, Inc.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA
  18  */
  19
  20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  21
  22 #include <linux/version.h>
  23 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
  24
  25 #include <linux/in.h>
  26 #include <linux/ip.h>
  27 #include <linux/net.h>
  28 #include <linux/rculist.h>
  29 #include <linux/udp.h>
  30
  31 #include <net/icmp.h>
  32 #include <net/ip.h>
  33 #include <net/udp.h>
  34 #include <net/ip_tunnels.h>
  35 #include <net/udp.h>
  36 #include <net/rtnetlink.h>
  37 #include <net/route.h>
  38 #include <net/dsfield.h>
  39 #include <net/inet_ecn.h>
  40 #include <net/net_namespace.h>
  41 #include <net/netns/generic.h>
  42 #include <net/vxlan.h>
  43
  44 #include "datapath.h"
  45 #include "tunnel.h"
  46 #include "vport.h"
  47
  48 #define OVS_VXLAN_RCV_PRIORITY          8
  49
  50 /**
  51  * struct vxlan_port - Keeps track of open UDP ports
  52  * @vh: vxlan_handler created for the port.
  53  * @name: vport name.
  54  */
  55 struct vxlan_port {
  56         struct vxlan_handler *vh;
  57         char name[IFNAMSIZ];
  58 };
  59
  60 static inline struct vxlan_port *vxlan_vport(const struct vport *vport)
  61 {
  62         return vport_priv(vport);
  63 }
  64
  65 /* Called with rcu_read_lock and BH disabled. */
  66 static int vxlan_rcv(struct vxlan_handler *vh, struct sk_buff *skb, __be32 vx_vni)
  67 {
  68         struct vport *vport = vh->data;
  69         struct iphdr *iph;
  70         struct ovs_key_ipv4_tunnel tun_key;
  71         __be64 key;
  72
  73         /* Save outer tunnel values */
  74         iph = ip_hdr(skb);
  75         key = cpu_to_be64(ntohl(vx_vni) >> 8);
  76         tnl_tun_key_init(&tun_key, iph, key, TUNNEL_KEY);
  77
  78         ovs_vport_receive(vport, skb, &tun_key);
  79         return PACKET_RCVD;
  80 }
  81
  82 static int vxlan_get_options(const struct vport *vport, struct sk_buff *skb)
  83 {
  84         struct vxlan_port *vxlan_port = vxlan_vport(vport);
  85         __be16 dst_port = inet_sport(vxlan_port->vh->vs->sock->sk);
  86
  87         if (nla_put_u16(skb, OVS_TUNNEL_ATTR_DST_PORT, ntohs(dst_port)))
  88                 return -EMSGSIZE;
  89         return 0;
  90 }
  91
  92 static void vxlan_tnl_destroy(struct vport *vport)
  93 {
  94         struct vxlan_port *vxlan_port = vxlan_vport(vport);
  95
  96         vxlan_handler_put(vxlan_port->vh);
  97
  98         ovs_vport_deferred_free(vport);
  99 }
 100
 101 static struct vport *vxlan_tnl_create(const struct vport_parms *parms)
 102 {
 103         struct net *net = ovs_dp_get_net(parms->dp);
 104         struct nlattr *options = parms->options;
 105         struct vxlan_port *vxlan_port;
 106         struct vxlan_handler *vh;
 107         struct vport *vport;
 108         struct nlattr *a;
 109         u16 dst_port;
 110         int err;
 111
 112         if (!options) {
 113                 err = -EINVAL;
 114                 goto error;
 115         }
 116         a = nla_find_nested(options, OVS_TUNNEL_ATTR_DST_PORT);
 117         if (a && nla_len(a) == sizeof(u16)) {
 118                 dst_port = nla_get_u16(a);
 119         } else {
 120                 /* Require destination port from userspace. */
 121                 err = -EINVAL;
 122                 goto error;
 123         }
 124
 125         vport = ovs_vport_alloc(sizeof(struct vxlan_port),
 126                                 &ovs_vxlan_vport_ops, parms);
 127         if (IS_ERR(vport))
 128                 return vport;
 129
 130         vxlan_port = vxlan_vport(vport);
 131         strncpy(vxlan_port->name, parms->name, IFNAMSIZ);
 132
 133         vh = vxlan_handler_add(net, htons(dst_port), vxlan_rcv,
 134                                vport, OVS_VXLAN_RCV_PRIORITY, true);
 135         if (IS_ERR(vh)) {
 136                 ovs_vport_free(vport);
 137                 return (void *)vh;
 138         }
 139         vxlan_port->vh = vh;
 140
 141         return vport;
 142
 143 error:
 144         return ERR_PTR(err);
 145 }
 146
 147 static int vxlan_tnl_send(struct vport *vport, struct sk_buff *skb)
 148 {
 149         struct vxlan_port *vxlan_port = vxlan_vport(vport);
 150         __be16 dst_port = inet_sport(vxlan_port->vh->vs->sock->sk);
 151         struct net *net = ovs_dp_get_net(vport->dp);
 152         struct rtable *rt;
 153         __be16 src_port;
 154         __be32 saddr;
 155         __be16 df;
 156         int port_min;
 157         int port_max;
 158         int err;
 159
 160         if (unlikely(!OVS_CB(skb)->tun_key)) {
 161                 err = -EINVAL;
 162                 goto error;
 163         }
 164
 165         forward_ip_summed(skb, true);
 166
 167         /* Route lookup */
 168         saddr = OVS_CB(skb)->tun_key->ipv4_src;
 169         rt = find_route(ovs_dp_get_net(vport->dp),
 170                         &saddr,
 171                         OVS_CB(skb)->tun_key->ipv4_dst,
 172                         IPPROTO_UDP,
 173                         OVS_CB(skb)->tun_key->ipv4_tos,
 174                         skb_get_mark(skb));
 175         if (IS_ERR(rt)) {
 176                 err = PTR_ERR(rt);
 177                 goto error;
 178         }
 179
 180         df = OVS_CB(skb)->tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ?
 181                 htons(IP_DF) : 0;
 182
 183         skb->local_df = 1;
 184
 185         inet_get_local_port_range(&port_min, &port_max);
 186         src_port = vxlan_src_port(port_min, port_max, skb);
 187
 188         err = vxlan_xmit_skb(net, vxlan_port->vh, rt, skb,
 189                              saddr, OVS_CB(skb)->tun_key->ipv4_dst,
 190                              OVS_CB(skb)->tun_key->ipv4_tos,
 191                              OVS_CB(skb)->tun_key->ipv4_ttl, df,
 192                              src_port, dst_port,
 193                              htonl(be64_to_cpu(OVS_CB(skb)->tun_key->tun_id) << 8));
 194         if (err < 0)
 195                 ip_rt_put(rt);
 196 error:
 197         return err;
 198 }
 199
 200 static const char *vxlan_get_name(const struct vport *vport)
 201 {
 202         struct vxlan_port *vxlan_port = vxlan_vport(vport);
 203         return vxlan_port->name;
 204 }
 205
 206 const struct vport_ops ovs_vxlan_vport_ops = {
 207         .type           = OVS_VPORT_TYPE_VXLAN,
 208         .create         = vxlan_tnl_create,
 209         .destroy        = vxlan_tnl_destroy,
 210         .get_name       = vxlan_get_name,
 211         .get_options    = vxlan_get_options,
 212         .send           = vxlan_tnl_send,
 213 };
 214 #else
 215 #warning VXLAN tunneling will not be available on kernels before 2.6.26
 216 #endif /* Linux kernel < 2.6.26 */