net/openvswitch/vport-vxlan.c

   1 /*
   2  * Copyright (c) 2014 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 #include <linux/module.h>
  28
  29 #include <net/icmp.h>
  30 #include <net/ip.h>
  31 #include <net/udp.h>
  32 #include <net/ip_tunnels.h>
  33 #include <net/rtnetlink.h>
  34 #include <net/route.h>
  35 #include <net/dsfield.h>
  36 #include <net/inet_ecn.h>
  37 #include <net/net_namespace.h>
  38 #include <net/netns/generic.h>
  39 #include <net/vxlan.h>
  40
  41 #include "datapath.h"
  42 #include "vport.h"
  43 #include "vport-vxlan.h"
  44
  45 /**
  46  * struct vxlan_port - Keeps track of open UDP ports
  47  * @vs: vxlan_sock created for the port.
  48  * @name: vport name.
  49  */
  50 struct vxlan_port {
  51         struct vxlan_sock *vs;
  52         char name[IFNAMSIZ];
  53         u32 exts; /* VXLAN_F_* in <net/vxlan.h> */
  54 };
  55
  56 static struct vport_ops ovs_vxlan_vport_ops;
  57
  58 static inline struct vxlan_port *vxlan_vport(const struct vport *vport)
  59 {
  60         return vport_priv(vport);
  61 }
  62
  63 /* Called with rcu_read_lock and BH disabled. */
  64 static void vxlan_rcv(struct vxlan_sock *vs, struct sk_buff *skb,
  65                       struct vxlan_metadata *md)
  66 {
  67         struct ovs_tunnel_info tun_info;
  68         struct vxlan_port *vxlan_port;
  69         struct vport *vport = vs->data;
  70         struct iphdr *iph;
  71         struct ovs_vxlan_opts opts = {
  72                 .gbp = md->gbp,
  73         };
  74         __be64 key;
  75         __be16 flags;
  76
  77         flags = TUNNEL_KEY | (udp_hdr(skb)->check != 0 ? TUNNEL_CSUM : 0);
  78         vxlan_port = vxlan_vport(vport);
  79         if (vxlan_port->exts & VXLAN_F_GBP && md->gbp)
  80                 flags |= TUNNEL_VXLAN_OPT;
  81
  82         /* Save outer tunnel values */
  83         iph = ip_hdr(skb);
  84         key = cpu_to_be64(ntohl(md->vni) >> 8);
  85         ovs_flow_tun_info_init(&tun_info, iph,
  86                                udp_hdr(skb)->source, udp_hdr(skb)->dest,
  87                                key, flags, &opts, sizeof(opts));
  88
  89         ovs_vport_receive(vport, skb, &tun_info);
  90 }
  91
  92 static int vxlan_get_options(const struct vport *vport, struct sk_buff *skb)
  93 {
  94         struct vxlan_port *vxlan_port = vxlan_vport(vport);
  95         __be16 dst_port = inet_sk(vxlan_port->vs->sock->sk)->inet_sport;
  96
  97         if (nla_put_u16(skb, OVS_TUNNEL_ATTR_DST_PORT, ntohs(dst_port)))
  98                 return -EMSGSIZE;
  99
 100         if (vxlan_port->exts) {
 101                 struct nlattr *exts;
 102
 103                 exts = nla_nest_start(skb, OVS_TUNNEL_ATTR_EXTENSION);
 104                 if (!exts)
 105                         return -EMSGSIZE;
 106
 107                 if (vxlan_port->exts & VXLAN_F_GBP &&
 108                     nla_put_flag(skb, OVS_VXLAN_EXT_GBP))
 109                         return -EMSGSIZE;
 110
 111                 nla_nest_end(skb, exts);
 112         }
 113
 114         return 0;
 115 }
 116
 117 static void vxlan_tnl_destroy(struct vport *vport)
 118 {
 119         struct vxlan_port *vxlan_port = vxlan_vport(vport);
 120
 121         vxlan_sock_release(vxlan_port->vs);
 122
 123         ovs_vport_deferred_free(vport);
 124 }
 125
 126 static const struct nla_policy exts_policy[OVS_VXLAN_EXT_MAX+1] = {
 127         [OVS_VXLAN_EXT_GBP]     = { .type = NLA_FLAG, },
 128 };
 129
 130 static int vxlan_configure_exts(struct vport *vport, struct nlattr *attr)
 131 {
 132         struct nlattr *exts[OVS_VXLAN_EXT_MAX+1];
 133         struct vxlan_port *vxlan_port;
 134         int err;
 135
 136         if (nla_len(attr) < sizeof(struct nlattr))
 137                 return -EINVAL;
 138
 139         err = nla_parse_nested(exts, OVS_VXLAN_EXT_MAX, attr, exts_policy);
 140         if (err < 0)
 141                 return err;
 142
 143         vxlan_port = vxlan_vport(vport);
 144
 145         if (exts[OVS_VXLAN_EXT_GBP])
 146                 vxlan_port->exts |= VXLAN_F_GBP;
 147
 148         return 0;
 149 }
 150
 151 static struct vport *vxlan_tnl_create(const struct vport_parms *parms)
 152 {
 153         struct net *net = ovs_dp_get_net(parms->dp);
 154         struct nlattr *options = parms->options;
 155         struct vxlan_port *vxlan_port;
 156         struct vxlan_sock *vs;
 157         struct vport *vport;
 158         struct nlattr *a;
 159         u16 dst_port;
 160         int err;
 161
 162         if (!options) {
 163                 err = -EINVAL;
 164                 goto error;
 165         }
 166         a = nla_find_nested(options, OVS_TUNNEL_ATTR_DST_PORT);
 167         if (a && nla_len(a) == sizeof(u16)) {
 168                 dst_port = nla_get_u16(a);
 169         } else {
 170                 /* Require destination port from userspace. */
 171                 err = -EINVAL;
 172                 goto error;
 173         }
 174
 175         vport = ovs_vport_alloc(sizeof(struct vxlan_port),
 176                                 &ovs_vxlan_vport_ops, parms);
 177         if (IS_ERR(vport))
 178                 return vport;
 179
 180         vxlan_port = vxlan_vport(vport);
 181         strncpy(vxlan_port->name, parms->name, IFNAMSIZ);
 182
 183         a = nla_find_nested(options, OVS_TUNNEL_ATTR_EXTENSION);
 184         if (a) {
 185                 err = vxlan_configure_exts(vport, a);
 186                 if (err) {
 187                         ovs_vport_free(vport);
 188                         goto error;
 189                 }
 190         }
 191
 192         vs = vxlan_sock_add(net, htons(dst_port), vxlan_rcv, vport, true,
 193                             vxlan_port->exts);
 194         if (IS_ERR(vs)) {
 195                 ovs_vport_free(vport);
 196                 return (void *)vs;
 197         }
 198         vxlan_port->vs = vs;
 199
 200         return vport;
 201
 202 error:
 203         return ERR_PTR(err);
 204 }
 205
 206 static int vxlan_ext_gbp(struct sk_buff *skb)
 207 {
 208         const struct ovs_tunnel_info *tun_info;
 209         const struct ovs_vxlan_opts *opts;
 210
 211         tun_info = OVS_CB(skb)->egress_tun_info;
 212         opts = tun_info->options;
 213
 214         if (tun_info->tunnel.tun_flags & TUNNEL_VXLAN_OPT &&
 215             tun_info->options_len >= sizeof(*opts))
 216                 return opts->gbp;
 217         else
 218                 return 0;
 219 }
 220
 221 static int vxlan_tnl_send(struct vport *vport, struct sk_buff *skb)
 222 {
 223         struct net *net = ovs_dp_get_net(vport->dp);
 224         struct vxlan_port *vxlan_port = vxlan_vport(vport);
 225         __be16 dst_port = inet_sk(vxlan_port->vs->sock->sk)->inet_sport;
 226         const struct ovs_key_ipv4_tunnel *tun_key;
 227         struct vxlan_metadata md = {0};
 228         struct rtable *rt;
 229         struct flowi4 fl;
 230         __be16 src_port;
 231         __be16 df;
 232         int err;
 233         u32 vxflags;
 234
 235         if (unlikely(!OVS_CB(skb)->egress_tun_info)) {
 236                 err = -EINVAL;
 237                 goto error;
 238         }
 239
 240         tun_key = &OVS_CB(skb)->egress_tun_info->tunnel;
 241         rt = ovs_tunnel_route_lookup(net, tun_key, skb->mark, &fl, IPPROTO_UDP);
 242         if (IS_ERR(rt)) {
 243                 err = PTR_ERR(rt);
 244                 goto error;
 245         }
 246
 247         df = tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ?
 248                 htons(IP_DF) : 0;
 249
 250         skb->ignore_df = 1;
 251
 252         src_port = udp_flow_src_port(net, skb, 0, 0, true);
 253         md.vni = htonl(be64_to_cpu(tun_key->tun_id) << 8);
 254         md.gbp = vxlan_ext_gbp(skb);
 255         vxflags = vxlan_port->exts |
 256                       (tun_key->tun_flags & TUNNEL_CSUM ? VXLAN_F_UDP_CSUM : 0);
 257
 258         err = vxlan_xmit_skb(rt, skb, fl.saddr, tun_key->ipv4_dst,
 259                              tun_key->ipv4_tos, tun_key->ipv4_ttl, df,
 260                              src_port, dst_port,
 261                              &md, false, vxflags);
 262         if (err < 0)
 263                 ip_rt_put(rt);
 264         return err;
 265 error:
 266         kfree_skb(skb);
 267         return err;
 268 }
 269
 270 static int vxlan_get_egress_tun_info(struct vport *vport, struct sk_buff *skb,
 271                                      struct ovs_tunnel_info *egress_tun_info)
 272 {
 273         struct net *net = ovs_dp_get_net(vport->dp);
 274         struct vxlan_port *vxlan_port = vxlan_vport(vport);
 275         __be16 dst_port = inet_sk(vxlan_port->vs->sock->sk)->inet_sport;
 276         __be16 src_port;
 277         int port_min;
 278         int port_max;
 279
 280         inet_get_local_port_range(net, &port_min, &port_max);
 281         src_port = udp_flow_src_port(net, skb, 0, 0, true);
 282
 283         return ovs_tunnel_get_egress_info(egress_tun_info, net,
 284                                           OVS_CB(skb)->egress_tun_info,
 285                                           IPPROTO_UDP, skb->mark,
 286                                           src_port, dst_port);
 287 }
 288
 289 static const char *vxlan_get_name(const struct vport *vport)
 290 {
 291         struct vxlan_port *vxlan_port = vxlan_vport(vport);
 292         return vxlan_port->name;
 293 }
 294
 295 static struct vport_ops ovs_vxlan_vport_ops = {
 296         .type           = OVS_VPORT_TYPE_VXLAN,
 297         .create         = vxlan_tnl_create,
 298         .destroy        = vxlan_tnl_destroy,
 299         .get_name       = vxlan_get_name,
 300         .get_options    = vxlan_get_options,
 301         .send           = vxlan_tnl_send,
 302         .get_egress_tun_info    = vxlan_get_egress_tun_info,
 303         .owner          = THIS_MODULE,
 304 };
 305
 306 static int __init ovs_vxlan_tnl_init(void)
 307 {
 308         return ovs_vport_ops_register(&ovs_vxlan_vport_ops);
 309 }
 310
 311 static void __exit ovs_vxlan_tnl_exit(void)
 312 {
 313         ovs_vport_ops_unregister(&ovs_vxlan_vport_ops);
 314 }
 315
 316 module_init(ovs_vxlan_tnl_init);
 317 module_exit(ovs_vxlan_tnl_exit);
 318
 319 MODULE_DESCRIPTION("OVS: VXLAN switching port");
 320 MODULE_LICENSE("GPL");
 321 MODULE_ALIAS("vport-type-4");