net/openvswitch/vport-vxlan.c

   1 /*
   2  * Copyright (c) 2013 Nicira, Inc.
   3  * Copyright (c) 2013 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/in.h>
  23 #include <linux/ip.h>
  24 #include <linux/net.h>
  25 #include <linux/rculist.h>
  26 #include <linux/udp.h>
  27
  28 #include <net/icmp.h>
  29 #include <net/ip.h>
  30 #include <net/udp.h>
  31 #include <net/ip_tunnels.h>
  32 #include <net/rtnetlink.h>
  33 #include <net/route.h>
  34 #include <net/dsfield.h>
  35 #include <net/inet_ecn.h>
  36 #include <net/net_namespace.h>
  37 #include <net/netns/generic.h>
  38 #include <net/vxlan.h>
  39
  40 #include "datapath.h"
  41 #include "vport.h"
  42
  43 /**
  44  * struct vxlan_port - Keeps track of open UDP ports
  45  * @vs: vxlan_sock created for the port.
  46  * @name: vport name.
  47  */
  48 struct vxlan_port {
  49         struct vxlan_sock *vs;
  50         char name[IFNAMSIZ];
  51 };
  52
  53 static inline struct vxlan_port *vxlan_vport(const struct vport *vport)
  54 {
  55         return vport_priv(vport);
  56 }
  57
  58 /* Called with rcu_read_lock and BH disabled. */
  59 static void vxlan_rcv(struct vxlan_sock *vs, struct sk_buff *skb, __be32 vx_vni)
  60 {
  61         struct ovs_key_ipv4_tunnel tun_key;
  62         struct vport *vport = vs->data;
  63         struct iphdr *iph;
  64         __be64 key;
  65
  66         /* Save outer tunnel values */
  67         iph = ip_hdr(skb);
  68         key = cpu_to_be64(ntohl(vx_vni) >> 8);
  69         ovs_flow_tun_key_init(&tun_key, iph, key, TUNNEL_KEY);
  70
  71         ovs_vport_receive(vport, skb, &tun_key);
  72 }
  73
  74 static int vxlan_get_options(const struct vport *vport, struct sk_buff *skb)
  75 {
  76         struct vxlan_port *vxlan_port = vxlan_vport(vport);
  77         __be16 dst_port = inet_sk(vxlan_port->vs->sock->sk)->inet_sport;
  78
  79         if (nla_put_u16(skb, OVS_TUNNEL_ATTR_DST_PORT, ntohs(dst_port)))
  80                 return -EMSGSIZE;
  81         return 0;
  82 }
  83
  84 static void vxlan_tnl_destroy(struct vport *vport)
  85 {
  86         struct vxlan_port *vxlan_port = vxlan_vport(vport);
  87
  88         vxlan_sock_release(vxlan_port->vs);
  89
  90         ovs_vport_deferred_free(vport);
  91 }
  92
  93 static struct vport *vxlan_tnl_create(const struct vport_parms *parms)
  94 {
  95         struct net *net = ovs_dp_get_net(parms->dp);
  96         struct nlattr *options = parms->options;
  97         struct vxlan_port *vxlan_port;
  98         struct vxlan_sock *vs;
  99         struct vport *vport;
 100         struct nlattr *a;
 101         u16 dst_port;
 102         int err;
 103
 104         if (!options) {
 105                 err = -EINVAL;
 106                 goto error;
 107         }
 108         a = nla_find_nested(options, OVS_TUNNEL_ATTR_DST_PORT);
 109         if (a && nla_len(a) == sizeof(u16)) {
 110                 dst_port = nla_get_u16(a);
 111         } else {
 112                 /* Require destination port from userspace. */
 113                 err = -EINVAL;
 114                 goto error;
 115         }
 116
 117         vport = ovs_vport_alloc(sizeof(struct vxlan_port),
 118                                 &ovs_vxlan_vport_ops, parms);
 119         if (IS_ERR(vport))
 120                 return vport;
 121
 122         vxlan_port = vxlan_vport(vport);
 123         strncpy(vxlan_port->name, parms->name, IFNAMSIZ);
 124
 125         vs = vxlan_sock_add(net, htons(dst_port), vxlan_rcv, vport, true, 0);
 126         if (IS_ERR(vs)) {
 127                 ovs_vport_free(vport);
 128                 return (void *)vs;
 129         }
 130         vxlan_port->vs = vs;
 131
 132         return vport;
 133
 134 error:
 135         return ERR_PTR(err);
 136 }
 137
 138 static int vxlan_tnl_send(struct vport *vport, struct sk_buff *skb)
 139 {
 140         struct net *net = ovs_dp_get_net(vport->dp);
 141         struct vxlan_port *vxlan_port = vxlan_vport(vport);
 142         __be16 dst_port = inet_sk(vxlan_port->vs->sock->sk)->inet_sport;
 143         struct rtable *rt;
 144         struct flowi4 fl;
 145         __be16 src_port;
 146         __be16 df;
 147         int err;
 148
 149         if (unlikely(!OVS_CB(skb)->tun_key)) {
 150                 err = -EINVAL;
 151                 goto error;
 152         }
 153
 154         /* Route lookup */
 155         memset(&fl, 0, sizeof(fl));
 156         fl.daddr = OVS_CB(skb)->tun_key->ipv4_dst;
 157         fl.saddr = OVS_CB(skb)->tun_key->ipv4_src;
 158         fl.flowi4_tos = RT_TOS(OVS_CB(skb)->tun_key->ipv4_tos);
 159         fl.flowi4_mark = skb->mark;
 160         fl.flowi4_proto = IPPROTO_UDP;
 161
 162         rt = ip_route_output_key(net, &fl);
 163         if (IS_ERR(rt)) {
 164                 err = PTR_ERR(rt);
 165                 goto error;
 166         }
 167
 168         df = OVS_CB(skb)->tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ?
 169                 htons(IP_DF) : 0;
 170
 171         skb->ignore_df = 1;
 172
 173         src_port = udp_flow_src_port(net, skb, 0, 0, true);
 174
 175         err = vxlan_xmit_skb(vxlan_port->vs, rt, skb,
 176                              fl.saddr, OVS_CB(skb)->tun_key->ipv4_dst,
 177                              OVS_CB(skb)->tun_key->ipv4_tos,
 178                              OVS_CB(skb)->tun_key->ipv4_ttl, df,
 179                              src_port, dst_port,
 180                              htonl(be64_to_cpu(OVS_CB(skb)->tun_key->tun_id) << 8),
 181                              false);
 182         if (err < 0)
 183                 ip_rt_put(rt);
 184 error:
 185         return err;
 186 }
 187
 188 static const char *vxlan_get_name(const struct vport *vport)
 189 {
 190         struct vxlan_port *vxlan_port = vxlan_vport(vport);
 191         return vxlan_port->name;
 192 }
 193
 194 const struct vport_ops ovs_vxlan_vport_ops = {
 195         .type           = OVS_VPORT_TYPE_VXLAN,
 196         .create         = vxlan_tnl_create,
 197         .destroy        = vxlan_tnl_destroy,
 198         .get_name       = vxlan_get_name,
 199         .get_options    = vxlan_get_options,
 200         .send           = vxlan_tnl_send,
 201 };