datapath/vport-geneve.c

   1 /*
   2  * Copyright (c) 2014 Nicira, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version
   7  * 2 of the License, or (at your option) any later version.
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/in.h>
  13 #include <linux/ip.h>
  14 #include <linux/net.h>
  15 #include <linux/rculist.h>
  16 #include <linux/udp.h>
  17 #include <linux/if_vlan.h>
  18 #include <linux/module.h>
  19
  20 #include <net/geneve.h>
  21 #include <net/icmp.h>
  22 #include <net/ip.h>
  23 #include <net/route.h>
  24 #include <net/udp.h>
  25 #include <net/xfrm.h>
  26
  27 #include "datapath.h"
  28 #include "vport.h"
  29
  30 /**
  31  * struct geneve_port - Keeps track of open UDP ports
  32  * @gs: The socket created for this port number.
  33  * @name: vport name.
  34  */
  35 struct geneve_port {
  36         struct geneve_sock *gs;
  37         char name[IFNAMSIZ];
  38 };
  39
  40 static LIST_HEAD(geneve_ports);
  41
  42 static inline struct geneve_port *geneve_vport(const struct vport *vport)
  43 {
  44         return vport_priv(vport);
  45 }
  46
  47 static inline struct genevehdr *geneve_hdr(const struct sk_buff *skb)
  48 {
  49         return (struct genevehdr *)(udp_hdr(skb) + 1);
  50 }
  51
  52 /* Convert 64 bit tunnel ID to 24 bit VNI. */
  53 static void tunnel_id_to_vni(__be64 tun_id, __u8 *vni)
  54 {
  55 #ifdef __BIG_ENDIAN
  56         vni[0] = (__force __u8)(tun_id >> 16);
  57         vni[1] = (__force __u8)(tun_id >> 8);
  58         vni[2] = (__force __u8)tun_id;
  59 #else
  60         vni[0] = (__force __u8)((__force u64)tun_id >> 40);
  61         vni[1] = (__force __u8)((__force u64)tun_id >> 48);
  62         vni[2] = (__force __u8)((__force u64)tun_id >> 56);
  63 #endif
  64 }
  65
  66 /* Convert 24 bit VNI to 64 bit tunnel ID. */
  67 static __be64 vni_to_tunnel_id(const __u8 *vni)
  68 {
  69 #ifdef __BIG_ENDIAN
  70         return (vni[0] << 16) | (vni[1] << 8) | vni[2];
  71 #else
  72         return (__force __be64)(((__force u64)vni[0] << 40) |
  73                                 ((__force u64)vni[1] << 48) |
  74                                 ((__force u64)vni[2] << 56));
  75 #endif
  76 }
  77
  78 static void geneve_rcv(struct geneve_sock *gs, struct sk_buff *skb)
  79 {
  80         struct vport *vport = gs->rcv_data;
  81         struct genevehdr *geneveh = geneve_hdr(skb);
  82         int opts_len;
  83         struct ovs_tunnel_info tun_info;
  84         __be64 key;
  85         __be16 flags;
  86
  87         opts_len = geneveh->opt_len * 4;
  88
  89         flags = TUNNEL_KEY | TUNNEL_GENEVE_OPT |
  90                 (udp_hdr(skb)->check != 0 ? TUNNEL_CSUM : 0) |
  91                 (geneveh->oam ? TUNNEL_OAM : 0) |
  92                 (geneveh->critical ? TUNNEL_CRIT_OPT : 0);
  93
  94         key = vni_to_tunnel_id(geneveh->vni);
  95
  96         ovs_flow_tun_info_init(&tun_info, ip_hdr(skb),
  97                                udp_hdr(skb)->source, udp_hdr(skb)->dest,
  98                                key, flags,
  99                                geneveh->options, opts_len);
 100
 101         ovs_vport_receive(vport, skb, &tun_info);
 102 }
 103
 104 static int geneve_get_options(const struct vport *vport,
 105                               struct sk_buff *skb)
 106 {
 107         struct geneve_port *geneve_port = geneve_vport(vport);
 108         __be16 dst_port = inet_sport(geneve_port->gs->sock->sk);
 109
 110         if (nla_put_u16(skb, OVS_TUNNEL_ATTR_DST_PORT, ntohs(dst_port)))
 111                 return -EMSGSIZE;
 112         return 0;
 113 }
 114
 115 static void geneve_tnl_destroy(struct vport *vport)
 116 {
 117         struct geneve_port *geneve_port = geneve_vport(vport);
 118
 119         geneve_sock_release(geneve_port->gs);
 120
 121         ovs_vport_deferred_free(vport);
 122 }
 123
 124 static struct vport *geneve_tnl_create(const struct vport_parms *parms)
 125 {
 126         struct net *net = ovs_dp_get_net(parms->dp);
 127         struct nlattr *options = parms->options;
 128         struct geneve_port *geneve_port;
 129         struct geneve_sock *gs;
 130         struct vport *vport;
 131         struct nlattr *a;
 132         int err;
 133         u16 dst_port;
 134
 135         if (!options) {
 136                 err = -EINVAL;
 137                 goto error;
 138         }
 139
 140         a = nla_find_nested(options, OVS_TUNNEL_ATTR_DST_PORT);
 141         if (a && nla_len(a) == sizeof(u16)) {
 142                 dst_port = nla_get_u16(a);
 143         } else {
 144                 /* Require destination port from userspace. */
 145                 err = -EINVAL;
 146                 goto error;
 147         }
 148
 149         vport = ovs_vport_alloc(sizeof(struct geneve_port),
 150                                 &ovs_geneve_vport_ops, parms);
 151         if (IS_ERR(vport))
 152                 return vport;
 153
 154         geneve_port = geneve_vport(vport);
 155         strncpy(geneve_port->name, parms->name, IFNAMSIZ);
 156
 157         gs = geneve_sock_add(net, htons(dst_port), geneve_rcv, vport, true, 0);
 158         if (IS_ERR(gs)) {
 159                 ovs_vport_free(vport);
 160                 return (void *)gs;
 161         }
 162         geneve_port->gs = gs;
 163
 164         return vport;
 165 error:
 166         return ERR_PTR(err);
 167 }
 168
 169 static int geneve_tnl_send(struct vport *vport, struct sk_buff *skb)
 170 {
 171         const struct ovs_key_ipv4_tunnel *tun_key;
 172         struct ovs_tunnel_info *tun_info;
 173         struct net *net = ovs_dp_get_net(vport->dp);
 174         struct geneve_port *geneve_port = geneve_vport(vport);
 175         __be16 dport = inet_sport(geneve_port->gs->sock->sk);
 176         __be16 sport;
 177         __be32 saddr;
 178         struct rtable *rt;
 179         u8 vni[3], opts_len, *opts;
 180         __be16 df;
 181         int err;
 182
 183         tun_info = OVS_CB(skb)->egress_tun_info;
 184         if (unlikely(!tun_info)) {
 185                 err = -EINVAL;
 186                 goto error;
 187         }
 188
 189         tun_key = &tun_info->tunnel;
 190
 191         saddr = tun_key->ipv4_src;
 192         rt = find_route(ovs_dp_get_net(vport->dp),
 193                         &saddr, tun_key->ipv4_dst,
 194                         IPPROTO_UDP, tun_key->ipv4_tos,
 195                         skb->mark);
 196         if (IS_ERR(rt)) {
 197                 err = PTR_ERR(rt);
 198                 goto error;
 199         }
 200
 201         df = tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
 202         sport = udp_flow_src_port(net, skb, 1, USHRT_MAX, true);
 203         tunnel_id_to_vni(tun_key->tun_id, vni);
 204         skb->ignore_df = 1;
 205
 206         if (tun_key->tun_flags & TUNNEL_GENEVE_OPT) {
 207                 opts = (u8 *)tun_info->options;
 208                 opts_len = tun_info->options_len;
 209         } else {
 210                 opts = NULL;
 211                 opts_len = 0;
 212         }
 213
 214         err = geneve_xmit_skb(geneve_port->gs, rt, skb, saddr,
 215                               tun_key->ipv4_dst, tun_key->ipv4_tos,
 216                               tun_key->ipv4_ttl, df, sport, dport,
 217                               tun_key->tun_flags, vni, opts_len, opts,
 218                               !!(tun_key->tun_flags & TUNNEL_CSUM), false);
 219         if (err < 0)
 220                 ip_rt_put(rt);
 221         return err;
 222
 223 error:
 224         kfree_skb(skb);
 225         return err;
 226 }
 227
 228 static const char *geneve_get_name(const struct vport *vport)
 229 {
 230         struct geneve_port *geneve_port = geneve_vport(vport);
 231
 232         return geneve_port->name;
 233 }
 234
 235 static int geneve_get_egress_tun_info(struct vport *vport, struct sk_buff *skb,
 236                                       struct ovs_tunnel_info *egress_tun_info)
 237 {
 238         struct geneve_port *geneve_port = geneve_vport(vport);
 239         struct net *net = ovs_dp_get_net(vport->dp);
 240         __be16 dport = inet_sport(geneve_port->gs->sock->sk);
 241         __be16 sport = udp_flow_src_port(net, skb, 1, USHRT_MAX, true);
 242
 243         /* Get tp_src and tp_dst, refert to geneve_build_header().
 244          */
 245         return ovs_tunnel_get_egress_info(egress_tun_info,
 246                                           ovs_dp_get_net(vport->dp),
 247                                           OVS_CB(skb)->egress_tun_info,
 248                                           IPPROTO_UDP, skb->mark, sport, dport);
 249 }
 250
 251 const struct vport_ops ovs_geneve_vport_ops = {
 252         .type                   = OVS_VPORT_TYPE_GENEVE,
 253         .create                 = geneve_tnl_create,
 254         .destroy                = geneve_tnl_destroy,
 255         .get_name               = geneve_get_name,
 256         .get_options            = geneve_get_options,
 257         .send                   = geneve_tnl_send,
 258         .get_egress_tun_info    = geneve_get_egress_tun_info,
 259 };