target/linux/generic/patches-3.18/666-Add-support-for-MAP-E-FMRs-mesh-mode.patch

   1 From 775d6fe74d1eaec2ba387535b068dde2dc89de9e Mon Sep 17 00:00:00 2001
   2 From: Steven Barth <steven@midlink.org>
   3 Date: Thu, 22 May 2014 09:49:05 +0200
   4 Subject: [PATCH] Add support for MAP-E FMRs (mesh mode)
   5
   6 MAP-E FMRs (draft-ietf-softwire-map-10) are rules for IPv4-communication
   7 between MAP CEs (mesh mode) without the need to forward such data to a
   8 border relay. This is similar to how 6rd works but for IPv4 over IPv6.
   9
  10 Signed-off-by: Steven Barth <cyrus@openwrt.org>
  11 ---
  12  include/net/ip6_tunnel.h       |  13 ++
  13  include/uapi/linux/if_tunnel.h |  13 ++
  14  net/ipv6/ip6_tunnel.c          | 276 +++++++++++++++++++++++++++++++++++++++--
  15  3 files changed, 291 insertions(+), 11 deletions(-)
  16
  17 --- a/include/net/ip6_tunnel.h
  18 +++ b/include/net/ip6_tunnel.h
  19 @@ -15,6 +15,18 @@
  20  /* determine capability on a per-packet basis */
  21  #define IP6_TNL_F_CAP_PER_PACKET 0x40000
  22
  23 +/* IPv6 tunnel FMR */
  24 +struct __ip6_tnl_fmr {
  25 +       struct __ip6_tnl_fmr *next; /* next fmr in list */
  26 +       struct in6_addr ip6_prefix;
  27 +       struct in_addr ip4_prefix;
  28 +
  29 +       __u8 ip6_prefix_len;
  30 +       __u8 ip4_prefix_len;
  31 +       __u8 ea_len;
  32 +       __u8 offset;
  33 +};
  34 +
  35  struct __ip6_tnl_parm {
  36         char name[IFNAMSIZ];    /* name of tunnel device */
  37         int link;               /* ifindex of underlying L2 interface */
  38 @@ -25,6 +37,7 @@ struct __ip6_tnl_parm {
  39         __u32 flags;            /* tunnel flags */
  40         struct in6_addr laddr;  /* local tunnel end-point address */
  41         struct in6_addr raddr;  /* remote tunnel end-point address */
  42 +       struct __ip6_tnl_fmr *fmrs;     /* FMRs */
  43
  44         __be16                  i_flags;
  45         __be16                  o_flags;
  46 --- a/include/uapi/linux/if_tunnel.h
  47 +++ b/include/uapi/linux/if_tunnel.h
  48 @@ -57,10 +57,23 @@ enum {
  49         IFLA_IPTUN_ENCAP_FLAGS,
  50         IFLA_IPTUN_ENCAP_SPORT,
  51         IFLA_IPTUN_ENCAP_DPORT,
  52 +       IFLA_IPTUN_FMRS,
  53         __IFLA_IPTUN_MAX,
  54  };
  55  #define IFLA_IPTUN_MAX (__IFLA_IPTUN_MAX - 1)
  56
  57 +enum {
  58 +       IFLA_IPTUN_FMR_UNSPEC,
  59 +       IFLA_IPTUN_FMR_IP6_PREFIX,
  60 +       IFLA_IPTUN_FMR_IP4_PREFIX,
  61 +       IFLA_IPTUN_FMR_IP6_PREFIX_LEN,
  62 +       IFLA_IPTUN_FMR_IP4_PREFIX_LEN,
  63 +       IFLA_IPTUN_FMR_EA_LEN,
  64 +       IFLA_IPTUN_FMR_OFFSET,
  65 +       __IFLA_IPTUN_FMR_MAX,
  66 +};
  67 +#define IFLA_IPTUN_FMR_MAX (__IFLA_IPTUN_FMR_MAX - 1)
  68 +
  69  enum tunnel_encap_types {
  70         TUNNEL_ENCAP_NONE,
  71         TUNNEL_ENCAP_FOU,
  72 --- a/net/ipv6/ip6_tunnel.c
  73 +++ b/net/ipv6/ip6_tunnel.c
  74 @@ -16,6 +16,8 @@
  75   *      as published by the Free Software Foundation; either version
  76   *      2 of the License, or (at your option) any later version.
  77   *
  78 + *     Changes:
  79 + * Steven Barth <cyrus@openwrt.org>:           MAP-E FMR support
  80   */
  81
  82  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  83 @@ -77,11 +79,9 @@ static bool log_ecn_error = true;
  84  module_param(log_ecn_error, bool, 0644);
  85  MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  86
  87 -static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
  88 +static u32 HASH(const struct in6_addr *addr)
  89  {
  90 -       u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
  91 -
  92 -       return hash_32(hash, HASH_SIZE_SHIFT);
  93 +       return hash_32(ipv6_addr_hash(addr), HASH_SIZE_SHIFT);
  94  }
  95
  96  static int ip6_tnl_dev_init(struct net_device *dev);
  97 @@ -180,15 +180,24 @@ EXPORT_SYMBOL_GPL(ip6_tnl_dst_store);
  98  static struct ip6_tnl *
  99  ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
 100  {
 101 -       unsigned int hash = HASH(remote, local);
 102 +       unsigned int hash = HASH(local);
 103         struct ip6_tnl *t;
 104         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 105 +       struct __ip6_tnl_fmr *fmr;
 106
 107         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 108 -               if (ipv6_addr_equal(local, &t->parms.laddr) &&
 109 -                   ipv6_addr_equal(remote, &t->parms.raddr) &&
 110 -                   (t->dev->flags & IFF_UP))
 111 +               if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 112 +                               !(t->dev->flags & IFF_UP))
 113 +                       continue;
 114 +
 115 +               if (ipv6_addr_equal(remote, &t->parms.raddr))
 116                         return t;
 117 +
 118 +               for (fmr = t->parms.fmrs; fmr; fmr = fmr->next) {
 119 +                       if (ipv6_prefix_equal(remote, &fmr->ip6_prefix,
 120 +                                       fmr->ip6_prefix_len))
 121 +                               return t;
 122 +               }
 123         }
 124         t = rcu_dereference(ip6n->tnls_wc[0]);
 125         if (t && (t->dev->flags & IFF_UP))
 126 @@ -218,7 +227,7 @@ ip6_tnl_bucket(struct ip6_tnl_net *ip6n,
 127
 128         if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
 129                 prio = 1;
 130 -               h = HASH(remote, local);
 131 +               h = HASH(local);
 132         }
 133         return &ip6n->tnls[prio][h];
 134  }
 135 @@ -388,6 +397,12 @@ ip6_tnl_dev_uninit(struct net_device *de
 136         struct net *net = t->net;
 137         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 138
 139 +       while (t->parms.fmrs) {
 140 +               struct __ip6_tnl_fmr *next = t->parms.fmrs->next;
 141 +               kfree(t->parms.fmrs);
 142 +               t->parms.fmrs = next;
 143 +       }
 144 +
 145         if (dev == ip6n->fb_tnl_dev)
 146                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
 147         else
 148 @@ -781,6 +796,108 @@ int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
 149  }
 150  EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
 151
 152 +
 153 +/**
 154 + * ip4ip6_fmr_calc - calculate target / source IPv6-address based on FMR
 155 + *   @dest: destination IPv6 address buffer
 156 + *   @skb: received socket buffer
 157 + *   @fmr: MAP FMR
 158 + *   @xmit: Calculate for xmit or rcv
 159 + **/
 160 +static void ip4ip6_fmr_calc(struct in6_addr *dest,
 161 +               const struct iphdr *iph, const uint8_t *end,
 162 +               const struct __ip6_tnl_fmr *fmr, bool xmit)
 163 +{
 164 +       int psidlen = fmr->ea_len - (32 - fmr->ip4_prefix_len);
 165 +       u8 *portp = NULL;
 166 +       bool use_dest_addr;
 167 +       const struct iphdr *dsth = iph;
 168 +
 169 +       if ((u8*)dsth >= end)
 170 +               return;
 171 +
 172 +       /* find significant IP header */
 173 +       if (iph->protocol == IPPROTO_ICMP) {
 174 +               struct icmphdr *ih = (struct icmphdr*)(((u8*)dsth) + dsth->ihl * 4);
 175 +               if (ih && ((u8*)&ih[1]) <= end && (
 176 +                       ih->type == ICMP_DEST_UNREACH ||
 177 +                       ih->type == ICMP_SOURCE_QUENCH ||
 178 +                       ih->type == ICMP_TIME_EXCEEDED ||
 179 +                       ih->type == ICMP_PARAMETERPROB ||
 180 +                       ih->type == ICMP_REDIRECT))
 181 +                               dsth = (const struct iphdr*)&ih[1];
 182 +       }
 183 +
 184 +       /* in xmit-path use dest port by default and source port only if
 185 +               this is an ICMP reply to something else; vice versa in rcv-path */
 186 +       use_dest_addr = (xmit && dsth == iph) || (!xmit && dsth != iph);
 187 +
 188 +       /* get dst port */
 189 +       if (((u8*)&dsth[1]) <= end && (
 190 +               dsth->protocol == IPPROTO_UDP ||
 191 +               dsth->protocol == IPPROTO_TCP ||
 192 +               dsth->protocol == IPPROTO_SCTP ||
 193 +               dsth->protocol == IPPROTO_DCCP)) {
 194 +                       /* for UDP, TCP, SCTP and DCCP source and dest port
 195 +                       follow IPv4 header directly */
 196 +                       portp = ((u8*)dsth) + dsth->ihl * 4;
 197 +
 198 +                       if (use_dest_addr)
 199 +                               portp += sizeof(u16);
 200 +       } else if (iph->protocol == IPPROTO_ICMP) {
 201 +               struct icmphdr *ih = (struct icmphdr*)(((u8*)dsth) + dsth->ihl * 4);
 202 +
 203 +               /* use icmp identifier as port */
 204 +               if (((u8*)&ih) <= end && (
 205 +                   (use_dest_addr && (
 206 +                   ih->type == ICMP_ECHOREPLY ||
 207 +                       ih->type == ICMP_TIMESTAMPREPLY ||
 208 +                       ih->type == ICMP_INFO_REPLY ||
 209 +                       ih->type == ICMP_ADDRESSREPLY)) ||
 210 +                       (!use_dest_addr && (
 211 +                       ih->type == ICMP_ECHO ||
 212 +                       ih->type == ICMP_TIMESTAMP ||
 213 +                       ih->type == ICMP_INFO_REQUEST ||
 214 +                       ih->type == ICMP_ADDRESS)
 215 +                       )))
 216 +                               portp = (u8*)&ih->un.echo.id;
 217 +       }
 218 +
 219 +       if ((portp && &portp[2] <= end) || psidlen == 0) {
 220 +               int frombyte = fmr->ip6_prefix_len / 8;
 221 +               int fromrem = fmr->ip6_prefix_len % 8;
 222 +               int bytes = sizeof(struct in6_addr) - frombyte;
 223 +               const u32 *addr = (use_dest_addr) ? &iph->daddr : &iph->saddr;
 224 +               u64 eabits = ((u64)ntohl(*addr)) << (32 + fmr->ip4_prefix_len);
 225 +               u64 t = 0;
 226 +
 227 +               /* extract PSID from port and add it to eabits */
 228 +               u16 psidbits = 0;
 229 +               if (psidlen > 0) {
 230 +                       psidbits = ((u16)portp[0]) << 8 | ((u16)portp[1]);
 231 +                       psidbits >>= 16 - psidlen - fmr->offset;
 232 +                       psidbits = (u16)(psidbits << (16 - psidlen));
 233 +                       eabits |= ((u64)psidbits) << (48 - (fmr->ea_len - psidlen));
 234 +               }
 235 +
 236 +               /* rewrite destination address */
 237 +               *dest = fmr->ip6_prefix;
 238 +               memcpy(&dest->s6_addr[10], addr, sizeof(*addr));
 239 +               dest->s6_addr16[7] = htons(psidbits >> (16 - psidlen));
 240 +
 241 +               if (bytes > sizeof(u64))
 242 +                       bytes = sizeof(u64);
 243 +
 244 +               /* insert eabits */
 245 +               memcpy(&t, &dest->s6_addr[frombyte], bytes);
 246 +               t = be64_to_cpu(t) & ~(((((u64)1) << fmr->ea_len) - 1)
 247 +                       << (64 - fmr->ea_len - fromrem));
 248 +               t = cpu_to_be64(t | (eabits >> fromrem));
 249 +               memcpy(&dest->s6_addr[frombyte], &t, bytes);
 250 +       }
 251 +}
 252 +
 253 +
 254  /**
 255   * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally
 256   *   @skb: received socket buffer
 257 @@ -825,6 +942,26 @@ static int ip6_tnl_rcv(struct sk_buff *s
 258                 skb_reset_network_header(skb);
 259                 skb->protocol = htons(protocol);
 260                 memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 261 +               if (protocol == ETH_P_IP &&
 262 +                       !ipv6_addr_equal(&ipv6h->saddr, &t->parms.raddr)) {
 263 +                               /* Packet didn't come from BR, so lookup FMR */
 264 +                               struct __ip6_tnl_fmr *fmr;
 265 +                               struct in6_addr expected = t->parms.raddr;
 266 +                               for (fmr = t->parms.fmrs; fmr; fmr = fmr->next)
 267 +                                       if (ipv6_prefix_equal(&ipv6h->saddr,
 268 +                                               &fmr->ip6_prefix, fmr->ip6_prefix_len))
 269 +                                                       break;
 270 +
 271 +                               /* Check that IPv6 matches IPv4 source to prevent spoofing */
 272 +                               if (fmr)
 273 +                                       ip4ip6_fmr_calc(&expected, ip_hdr(skb),
 274 +                                                       skb_tail_pointer(skb), fmr, false);
 275 +
 276 +                               if (!ipv6_addr_equal(&ipv6h->saddr, &expected)) {
 277 +                                       rcu_read_unlock();
 278 +                                       goto discard;
 279 +                               }
 280 +               }
 281
 282                 __skb_tunnel_rx(skb, t->dev, t->net);
 283
 284 @@ -1086,6 +1223,7 @@ ip4ip6_tnl_xmit(struct sk_buff *skb, str
 285         __u8 dsfield;
 286         __u32 mtu;
 287         int err;
 288 +       struct __ip6_tnl_fmr *fmr;
 289
 290         if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) ||
 291             !ip6_tnl_xmit_ctl(t))
 292 @@ -1105,6 +1243,18 @@ ip4ip6_tnl_xmit(struct sk_buff *skb, str
 293         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 294                 fl6.flowi6_mark = skb->mark;
 295
 296 +       /* try to find matching FMR */
 297 +       for (fmr = t->parms.fmrs; fmr; fmr = fmr->next) {
 298 +               unsigned mshift = 32 - fmr->ip4_prefix_len;
 299 +               if (ntohl(fmr->ip4_prefix.s_addr) >> mshift ==
 300 +                               ntohl(iph->daddr) >> mshift)
 301 +                       break;
 302 +       }
 303 +
 304 +       /* change dstaddr according to FMR */
 305 +       if (fmr)
 306 +               ip4ip6_fmr_calc(&fl6.daddr, iph, skb_tail_pointer(skb), fmr, true);
 307 +
 308         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 309         if (err != 0) {
 310                 /* XXX: send ICMP error even if DF is not set. */
 311 @@ -1273,6 +1423,14 @@ ip6_tnl_change(struct ip6_tnl *t, const
 312         t->parms.flowinfo = p->flowinfo;
 313         t->parms.link = p->link;
 314         t->parms.proto = p->proto;
 315 +
 316 +       while (t->parms.fmrs) {
 317 +               struct __ip6_tnl_fmr *next = t->parms.fmrs->next;
 318 +               kfree(t->parms.fmrs);
 319 +               t->parms.fmrs = next;
 320 +       }
 321 +       t->parms.fmrs = p->fmrs;
 322 +
 323         ip6_tnl_dst_reset(t);
 324         ip6_tnl_link_config(t);
 325         return 0;
 326 @@ -1303,6 +1461,7 @@ ip6_tnl_parm_from_user(struct __ip6_tnl_
 327         p->flowinfo = u->flowinfo;
 328         p->link = u->link;
 329         p->proto = u->proto;
 330 +       p->fmrs = NULL;
 331         memcpy(p->name, u->name, sizeof(u->name));
 332  }
 333
 334 @@ -1578,6 +1737,15 @@ static int ip6_tnl_validate(struct nlatt
 335         return 0;
 336  }
 337
 338 +static const struct nla_policy ip6_tnl_fmr_policy[IFLA_IPTUN_FMR_MAX + 1] = {
 339 +       [IFLA_IPTUN_FMR_IP6_PREFIX] = { .len = sizeof(struct in6_addr) },
 340 +       [IFLA_IPTUN_FMR_IP4_PREFIX] = { .len = sizeof(struct in_addr) },
 341 +       [IFLA_IPTUN_FMR_IP6_PREFIX_LEN] = { .type = NLA_U8 },
 342 +       [IFLA_IPTUN_FMR_IP4_PREFIX_LEN] = { .type = NLA_U8 },
 343 +       [IFLA_IPTUN_FMR_EA_LEN] = { .type = NLA_U8 },
 344 +       [IFLA_IPTUN_FMR_OFFSET] = { .type = NLA_U8 }
 345 +};
 346 +
 347  static void ip6_tnl_netlink_parms(struct nlattr *data[],
 348                                   struct __ip6_tnl_parm *parms)
 349  {
 350 @@ -1611,6 +1779,46 @@ static void ip6_tnl_netlink_parms(struct
 351
 352         if (data[IFLA_IPTUN_PROTO])
 353                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
 354 +
 355 +       if (data[IFLA_IPTUN_FMRS]) {
 356 +               unsigned rem;
 357 +               struct nlattr *fmr;
 358 +               nla_for_each_nested(fmr, data[IFLA_IPTUN_FMRS], rem) {
 359 +                       struct nlattr *fmrd[IFLA_IPTUN_FMR_MAX + 1], *c;
 360 +                       struct __ip6_tnl_fmr *nfmr;
 361 +
 362 +                       nla_parse_nested(fmrd, IFLA_IPTUN_FMR_MAX,
 363 +                               fmr, ip6_tnl_fmr_policy);
 364 +
 365 +                       if (!(nfmr = kzalloc(sizeof(*nfmr), GFP_KERNEL)))
 366 +                               continue;
 367 +
 368 +                       nfmr->offset = 6;
 369 +
 370 +                       if ((c = fmrd[IFLA_IPTUN_FMR_IP6_PREFIX]))
 371 +                               nla_memcpy(&nfmr->ip6_prefix, fmrd[IFLA_IPTUN_FMR_IP6_PREFIX],
 372 +                                       sizeof(nfmr->ip6_prefix));
 373 +
 374 +                       if ((c = fmrd[IFLA_IPTUN_FMR_IP4_PREFIX]))
 375 +                               nla_memcpy(&nfmr->ip4_prefix, fmrd[IFLA_IPTUN_FMR_IP4_PREFIX],
 376 +                                       sizeof(nfmr->ip4_prefix));
 377 +
 378 +                       if ((c = fmrd[IFLA_IPTUN_FMR_IP6_PREFIX_LEN]))
 379 +                               nfmr->ip6_prefix_len = nla_get_u8(c);
 380 +
 381 +                       if ((c = fmrd[IFLA_IPTUN_FMR_IP4_PREFIX_LEN]))
 382 +                               nfmr->ip4_prefix_len = nla_get_u8(c);
 383 +
 384 +                       if ((c = fmrd[IFLA_IPTUN_FMR_EA_LEN]))
 385 +                               nfmr->ea_len = nla_get_u8(c);
 386 +
 387 +                       if ((c = fmrd[IFLA_IPTUN_FMR_OFFSET]))
 388 +                               nfmr->offset = nla_get_u8(c);
 389 +
 390 +                       nfmr->next = parms->fmrs;
 391 +                       parms->fmrs = nfmr;
 392 +               }
 393 +       }
 394  }
 395
 396  static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
 397 @@ -1663,6 +1871,12 @@ static void ip6_tnl_dellink(struct net_d
 398
 399  static size_t ip6_tnl_get_size(const struct net_device *dev)
 400  {
 401 +       const struct ip6_tnl *t = netdev_priv(dev);
 402 +       struct __ip6_tnl_fmr *c;
 403 +       int fmrs = 0;
 404 +       for (c = t->parms.fmrs; c; c = c->next)
 405 +               ++fmrs;
 406 +
 407         return
 408                 /* IFLA_IPTUN_LINK */
 409                 nla_total_size(4) +
 410 @@ -1680,6 +1894,24 @@ static size_t ip6_tnl_get_size(const str
 411                 nla_total_size(4) +
 412                 /* IFLA_IPTUN_PROTO */
 413                 nla_total_size(1) +
 414 +               /* IFLA_IPTUN_FMRS */
 415 +               nla_total_size(0) +
 416 +               (
 417 +                       /* nest */
 418 +                       nla_total_size(0) +
 419 +                       /* IFLA_IPTUN_FMR_IP6_PREFIX */
 420 +                       nla_total_size(sizeof(struct in6_addr)) +
 421 +                       /* IFLA_IPTUN_FMR_IP4_PREFIX */
 422 +                       nla_total_size(sizeof(struct in_addr)) +
 423 +                       /* IFLA_IPTUN_FMR_EA_LEN */
 424 +                       nla_total_size(1) +
 425 +                       /* IFLA_IPTUN_FMR_IP6_PREFIX_LEN */
 426 +                       nla_total_size(1) +
 427 +                       /* IFLA_IPTUN_FMR_IP4_PREFIX_LEN */
 428 +                       nla_total_size(1) +
 429 +                       /* IFLA_IPTUN_FMR_OFFSET */
 430 +                       nla_total_size(1)
 431 +               ) * fmrs +
 432                 0;
 433  }
 434
 435 @@ -1687,6 +1919,9 @@ static int ip6_tnl_fill_info(struct sk_b
 436  {
 437         struct ip6_tnl *tunnel = netdev_priv(dev);
 438         struct __ip6_tnl_parm *parm = &tunnel->parms;
 439 +       struct __ip6_tnl_fmr *c;
 440 +       int fmrcnt = 0;
 441 +       struct nlattr *fmrs;
 442
 443         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
 444             nla_put(skb, IFLA_IPTUN_LOCAL, sizeof(struct in6_addr),
 445 @@ -1697,8 +1932,27 @@ static int ip6_tnl_fill_info(struct sk_b
 446             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
 447             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
 448             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
 449 -           nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto))
 450 +           nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
 451 +           !(fmrs = nla_nest_start(skb, IFLA_IPTUN_FMRS)))
 452                 goto nla_put_failure;
 453 +
 454 +       for (c = parm->fmrs; c; c = c->next) {
 455 +               struct nlattr *fmr = nla_nest_start(skb, ++fmrcnt);
 456 +               if (!fmr ||
 457 +                       nla_put(skb, IFLA_IPTUN_FMR_IP6_PREFIX,
 458 +                               sizeof(c->ip6_prefix), &c->ip6_prefix) ||
 459 +                       nla_put(skb, IFLA_IPTUN_FMR_IP4_PREFIX,
 460 +                               sizeof(c->ip4_prefix), &c->ip4_prefix) ||
 461 +                       nla_put_u8(skb, IFLA_IPTUN_FMR_IP6_PREFIX_LEN, c->ip6_prefix_len) ||
 462 +                       nla_put_u8(skb, IFLA_IPTUN_FMR_IP4_PREFIX_LEN, c->ip4_prefix_len) ||
 463 +                       nla_put_u8(skb, IFLA_IPTUN_FMR_EA_LEN, c->ea_len) ||
 464 +                       nla_put_u8(skb, IFLA_IPTUN_FMR_OFFSET, c->offset))
 465 +                               goto nla_put_failure;
 466 +
 467 +               nla_nest_end(skb, fmr);
 468 +       }
 469 +       nla_nest_end(skb, fmrs);
 470 +
 471         return 0;
 472
 473  nla_put_failure:
 474 @@ -1714,6 +1968,7 @@ static const struct nla_policy ip6_tnl_p
 475         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
 476         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
 477         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
 478 +       [IFLA_IPTUN_FMRS]               = { .type = NLA_NESTED },
 479  };
 480
 481  static struct rtnl_link_ops ip6_link_ops __read_mostly = {