linux/net/ipv6/ip6_gre.c
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   1/*
   2 *      GRE over IPv6 protocol decoder.
   3 *
   4 *      Authors: Dmitry Kozlov (xeb@mail.ru)
   5 *
   6 *      This program is free software; you can redistribute it and/or
   7 *      modify it under the terms of the GNU General Public License
   8 *      as published by the Free Software Foundation; either version
   9 *      2 of the License, or (at your option) any later version.
  10 *
  11 */
  12
  13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15#include <linux/capability.h>
  16#include <linux/module.h>
  17#include <linux/types.h>
  18#include <linux/kernel.h>
  19#include <linux/slab.h>
  20#include <linux/uaccess.h>
  21#include <linux/skbuff.h>
  22#include <linux/netdevice.h>
  23#include <linux/in.h>
  24#include <linux/tcp.h>
  25#include <linux/udp.h>
  26#include <linux/if_arp.h>
  27#include <linux/init.h>
  28#include <linux/in6.h>
  29#include <linux/inetdevice.h>
  30#include <linux/igmp.h>
  31#include <linux/netfilter_ipv4.h>
  32#include <linux/etherdevice.h>
  33#include <linux/if_ether.h>
  34#include <linux/hash.h>
  35#include <linux/if_tunnel.h>
  36#include <linux/ip6_tunnel.h>
  37
  38#include <net/sock.h>
  39#include <net/ip.h>
  40#include <net/ip_tunnels.h>
  41#include <net/icmp.h>
  42#include <net/protocol.h>
  43#include <net/addrconf.h>
  44#include <net/arp.h>
  45#include <net/checksum.h>
  46#include <net/dsfield.h>
  47#include <net/inet_ecn.h>
  48#include <net/xfrm.h>
  49#include <net/net_namespace.h>
  50#include <net/netns/generic.h>
  51#include <net/rtnetlink.h>
  52
  53#include <net/ipv6.h>
  54#include <net/ip6_fib.h>
  55#include <net/ip6_route.h>
  56#include <net/ip6_tunnel.h>
  57#include <net/gre.h>
  58
  59
  60static bool log_ecn_error = true;
  61module_param(log_ecn_error, bool, 0644);
  62MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  63
  64#define IP6_GRE_HASH_SIZE_SHIFT  5
  65#define IP6_GRE_HASH_SIZE (1 << IP6_GRE_HASH_SIZE_SHIFT)
  66
  67static unsigned int ip6gre_net_id __read_mostly;
  68struct ip6gre_net {
  69        struct ip6_tnl __rcu *tunnels[4][IP6_GRE_HASH_SIZE];
  70
  71        struct net_device *fb_tunnel_dev;
  72};
  73
  74static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
  75static struct rtnl_link_ops ip6gre_tap_ops __read_mostly;
  76static int ip6gre_tunnel_init(struct net_device *dev);
  77static void ip6gre_tunnel_setup(struct net_device *dev);
  78static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
  79static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
  80
  81/* Tunnel hash table */
  82
  83/*
  84   4 hash tables:
  85
  86   3: (remote,local)
  87   2: (remote,*)
  88   1: (*,local)
  89   0: (*,*)
  90
  91   We require exact key match i.e. if a key is present in packet
  92   it will match only tunnel with the same key; if it is not present,
  93   it will match only keyless tunnel.
  94
  95   All keysless packets, if not matched configured keyless tunnels
  96   will match fallback tunnel.
  97 */
  98
  99#define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(IP6_GRE_HASH_SIZE - 1))
 100static u32 HASH_ADDR(const struct in6_addr *addr)
 101{
 102        u32 hash = ipv6_addr_hash(addr);
 103
 104        return hash_32(hash, IP6_GRE_HASH_SIZE_SHIFT);
 105}
 106
 107#define tunnels_r_l     tunnels[3]
 108#define tunnels_r       tunnels[2]
 109#define tunnels_l       tunnels[1]
 110#define tunnels_wc      tunnels[0]
 111
 112/* Given src, dst and key, find appropriate for input tunnel. */
 113
 114static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 115                const struct in6_addr *remote, const struct in6_addr *local,
 116                __be32 key, __be16 gre_proto)
 117{
 118        struct net *net = dev_net(dev);
 119        int link = dev->ifindex;
 120        unsigned int h0 = HASH_ADDR(remote);
 121        unsigned int h1 = HASH_KEY(key);
 122        struct ip6_tnl *t, *cand = NULL;
 123        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 124        int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
 125                       ARPHRD_ETHER : ARPHRD_IP6GRE;
 126        int score, cand_score = 4;
 127
 128        for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
 129                if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 130                    !ipv6_addr_equal(remote, &t->parms.raddr) ||
 131                    key != t->parms.i_key ||
 132                    !(t->dev->flags & IFF_UP))
 133                        continue;
 134
 135                if (t->dev->type != ARPHRD_IP6GRE &&
 136                    t->dev->type != dev_type)
 137                        continue;
 138
 139                score = 0;
 140                if (t->parms.link != link)
 141                        score |= 1;
 142                if (t->dev->type != dev_type)
 143                        score |= 2;
 144                if (score == 0)
 145                        return t;
 146
 147                if (score < cand_score) {
 148                        cand = t;
 149                        cand_score = score;
 150                }
 151        }
 152
 153        for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
 154                if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
 155                    key != t->parms.i_key ||
 156                    !(t->dev->flags & IFF_UP))
 157                        continue;
 158
 159                if (t->dev->type != ARPHRD_IP6GRE &&
 160                    t->dev->type != dev_type)
 161                        continue;
 162
 163                score = 0;
 164                if (t->parms.link != link)
 165                        score |= 1;
 166                if (t->dev->type != dev_type)
 167                        score |= 2;
 168                if (score == 0)
 169                        return t;
 170
 171                if (score < cand_score) {
 172                        cand = t;
 173                        cand_score = score;
 174                }
 175        }
 176
 177        for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
 178                if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
 179                          (!ipv6_addr_equal(local, &t->parms.raddr) ||
 180                                 !ipv6_addr_is_multicast(local))) ||
 181                    key != t->parms.i_key ||
 182                    !(t->dev->flags & IFF_UP))
 183                        continue;
 184
 185                if (t->dev->type != ARPHRD_IP6GRE &&
 186                    t->dev->type != dev_type)
 187                        continue;
 188
 189                score = 0;
 190                if (t->parms.link != link)
 191                        score |= 1;
 192                if (t->dev->type != dev_type)
 193                        score |= 2;
 194                if (score == 0)
 195                        return t;
 196
 197                if (score < cand_score) {
 198                        cand = t;
 199                        cand_score = score;
 200                }
 201        }
 202
 203        for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
 204                if (t->parms.i_key != key ||
 205                    !(t->dev->flags & IFF_UP))
 206                        continue;
 207
 208                if (t->dev->type != ARPHRD_IP6GRE &&
 209                    t->dev->type != dev_type)
 210                        continue;
 211
 212                score = 0;
 213                if (t->parms.link != link)
 214                        score |= 1;
 215                if (t->dev->type != dev_type)
 216                        score |= 2;
 217                if (score == 0)
 218                        return t;
 219
 220                if (score < cand_score) {
 221                        cand = t;
 222                        cand_score = score;
 223                }
 224        }
 225
 226        if (cand)
 227                return cand;
 228
 229        dev = ign->fb_tunnel_dev;
 230        if (dev->flags & IFF_UP)
 231                return netdev_priv(dev);
 232
 233        return NULL;
 234}
 235
 236static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
 237                const struct __ip6_tnl_parm *p)
 238{
 239        const struct in6_addr *remote = &p->raddr;
 240        const struct in6_addr *local = &p->laddr;
 241        unsigned int h = HASH_KEY(p->i_key);
 242        int prio = 0;
 243
 244        if (!ipv6_addr_any(local))
 245                prio |= 1;
 246        if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
 247                prio |= 2;
 248                h ^= HASH_ADDR(remote);
 249        }
 250
 251        return &ign->tunnels[prio][h];
 252}
 253
 254static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
 255                const struct ip6_tnl *t)
 256{
 257        return __ip6gre_bucket(ign, &t->parms);
 258}
 259
 260static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
 261{
 262        struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
 263
 264        rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 265        rcu_assign_pointer(*tp, t);
 266}
 267
 268static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
 269{
 270        struct ip6_tnl __rcu **tp;
 271        struct ip6_tnl *iter;
 272
 273        for (tp = ip6gre_bucket(ign, t);
 274             (iter = rtnl_dereference(*tp)) != NULL;
 275             tp = &iter->next) {
 276                if (t == iter) {
 277                        rcu_assign_pointer(*tp, t->next);
 278                        break;
 279                }
 280        }
 281}
 282
 283static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
 284                                           const struct __ip6_tnl_parm *parms,
 285                                           int type)
 286{
 287        const struct in6_addr *remote = &parms->raddr;
 288        const struct in6_addr *local = &parms->laddr;
 289        __be32 key = parms->i_key;
 290        int link = parms->link;
 291        struct ip6_tnl *t;
 292        struct ip6_tnl __rcu **tp;
 293        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 294
 295        for (tp = __ip6gre_bucket(ign, parms);
 296             (t = rtnl_dereference(*tp)) != NULL;
 297             tp = &t->next)
 298                if (ipv6_addr_equal(local, &t->parms.laddr) &&
 299                    ipv6_addr_equal(remote, &t->parms.raddr) &&
 300                    key == t->parms.i_key &&
 301                    link == t->parms.link &&
 302                    type == t->dev->type)
 303                        break;
 304
 305        return t;
 306}
 307
 308static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
 309                const struct __ip6_tnl_parm *parms, int create)
 310{
 311        struct ip6_tnl *t, *nt;
 312        struct net_device *dev;
 313        char name[IFNAMSIZ];
 314        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 315
 316        t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
 317        if (t && create)
 318                return NULL;
 319        if (t || !create)
 320                return t;
 321
 322        if (parms->name[0])
 323                strlcpy(name, parms->name, IFNAMSIZ);
 324        else
 325                strcpy(name, "ip6gre%d");
 326
 327        dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 328                           ip6gre_tunnel_setup);
 329        if (!dev)
 330                return NULL;
 331
 332        dev_net_set(dev, net);
 333
 334        nt = netdev_priv(dev);
 335        nt->parms = *parms;
 336        dev->rtnl_link_ops = &ip6gre_link_ops;
 337
 338        nt->dev = dev;
 339        nt->net = dev_net(dev);
 340        ip6gre_tnl_link_config(nt, 1);
 341
 342        if (register_netdevice(dev) < 0)
 343                goto failed_free;
 344
 345        /* Can use a lockless transmit, unless we generate output sequences */
 346        if (!(nt->parms.o_flags & TUNNEL_SEQ))
 347                dev->features |= NETIF_F_LLTX;
 348
 349        dev_hold(dev);
 350        ip6gre_tunnel_link(ign, nt);
 351        return nt;
 352
 353failed_free:
 354        free_netdev(dev);
 355        return NULL;
 356}
 357
 358static void ip6gre_tunnel_uninit(struct net_device *dev)
 359{
 360        struct ip6_tnl *t = netdev_priv(dev);
 361        struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
 362
 363        ip6gre_tunnel_unlink(ign, t);
 364        dst_cache_reset(&t->dst_cache);
 365        dev_put(dev);
 366}
 367
 368
 369static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 370                       u8 type, u8 code, int offset, __be32 info)
 371{
 372        const struct gre_base_hdr *greh;
 373        const struct ipv6hdr *ipv6h;
 374        int grehlen = sizeof(*greh);
 375        struct ip6_tnl *t;
 376        int key_off = 0;
 377        __be16 flags;
 378        __be32 key;
 379
 380        if (!pskb_may_pull(skb, offset + grehlen))
 381                return;
 382        greh = (const struct gre_base_hdr *)(skb->data + offset);
 383        flags = greh->flags;
 384        if (flags & (GRE_VERSION | GRE_ROUTING))
 385                return;
 386        if (flags & GRE_CSUM)
 387                grehlen += 4;
 388        if (flags & GRE_KEY) {
 389                key_off = grehlen + offset;
 390                grehlen += 4;
 391        }
 392
 393        if (!pskb_may_pull(skb, offset + grehlen))
 394                return;
 395        ipv6h = (const struct ipv6hdr *)skb->data;
 396        greh = (const struct gre_base_hdr *)(skb->data + offset);
 397        key = key_off ? *(__be32 *)(skb->data + key_off) : 0;
 398
 399        t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
 400                                 key, greh->protocol);
 401        if (!t)
 402                return;
 403
 404        switch (type) {
 405                __u32 teli;
 406                struct ipv6_tlv_tnl_enc_lim *tel;
 407                __u32 mtu;
 408        case ICMPV6_DEST_UNREACH:
 409                net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
 410                                    t->parms.name);
 411                break;
 412        case ICMPV6_TIME_EXCEED:
 413                if (code == ICMPV6_EXC_HOPLIMIT) {
 414                        net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 415                                            t->parms.name);
 416                }
 417                break;
 418        case ICMPV6_PARAMPROB:
 419                teli = 0;
 420                if (code == ICMPV6_HDR_FIELD)
 421                        teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 422
 423                if (teli && teli == be32_to_cpu(info) - 2) {
 424                        tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 425                        if (tel->encap_limit == 0) {
 426                                net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 427                                                    t->parms.name);
 428                        }
 429                } else {
 430                        net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 431                                            t->parms.name);
 432                }
 433                break;
 434        case ICMPV6_PKT_TOOBIG:
 435                mtu = be32_to_cpu(info) - offset;
 436                if (mtu < IPV6_MIN_MTU)
 437                        mtu = IPV6_MIN_MTU;
 438                t->dev->mtu = mtu;
 439                break;
 440        }
 441
 442        if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
 443                t->err_count++;
 444        else
 445                t->err_count = 1;
 446        t->err_time = jiffies;
 447}
 448
 449static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
 450{
 451        const struct ipv6hdr *ipv6h;
 452        struct ip6_tnl *tunnel;
 453
 454        ipv6h = ipv6_hdr(skb);
 455        tunnel = ip6gre_tunnel_lookup(skb->dev,
 456                                      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
 457                                      tpi->proto);
 458        if (tunnel) {
 459                ip6_tnl_rcv(tunnel, skb, tpi, NULL, false);
 460
 461                return PACKET_RCVD;
 462        }
 463
 464        return PACKET_REJECT;
 465}
 466
 467static int gre_rcv(struct sk_buff *skb)
 468{
 469        struct tnl_ptk_info tpi;
 470        bool csum_err = false;
 471        int hdr_len;
 472
 473        hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
 474        if (hdr_len < 0)
 475                goto drop;
 476
 477        if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
 478                goto drop;
 479
 480        if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
 481                return 0;
 482
 483        icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 484drop:
 485        kfree_skb(skb);
 486        return 0;
 487}
 488
 489static int gre_handle_offloads(struct sk_buff *skb, bool csum)
 490{
 491        return iptunnel_handle_offloads(skb,
 492                                        csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
 493}
 494
 495static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
 496                               struct net_device *dev, __u8 dsfield,
 497                               struct flowi6 *fl6, int encap_limit,
 498                               __u32 *pmtu, __be16 proto)
 499{
 500        struct ip6_tnl *tunnel = netdev_priv(dev);
 501        __be16 protocol = (dev->type == ARPHRD_ETHER) ?
 502                          htons(ETH_P_TEB) : proto;
 503
 504        if (dev->type == ARPHRD_ETHER)
 505                IPCB(skb)->flags = 0;
 506
 507        if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
 508                fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
 509        else
 510                fl6->daddr = tunnel->parms.raddr;
 511
 512        if (tunnel->parms.o_flags & TUNNEL_SEQ)
 513                tunnel->o_seqno++;
 514
 515        /* Push GRE header. */
 516        gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
 517                         protocol, tunnel->parms.o_key, htonl(tunnel->o_seqno));
 518
 519        return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
 520                            NEXTHDR_GRE);
 521}
 522
 523static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 524{
 525        struct ip6_tnl *t = netdev_priv(dev);
 526        const struct iphdr  *iph = ip_hdr(skb);
 527        int encap_limit = -1;
 528        struct flowi6 fl6;
 529        __u8 dsfield;
 530        __u32 mtu;
 531        int err;
 532
 533        memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 534
 535        if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 536                encap_limit = t->parms.encap_limit;
 537
 538        memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 539
 540        if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 541                dsfield = ipv4_get_dsfield(iph);
 542        else
 543                dsfield = ip6_tclass(t->parms.flowinfo);
 544        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 545                fl6.flowi6_mark = skb->mark;
 546        else
 547                fl6.flowi6_mark = t->parms.fwmark;
 548
 549        fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
 550
 551        err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
 552        if (err)
 553                return -1;
 554
 555        err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
 556                          skb->protocol);
 557        if (err != 0) {
 558                /* XXX: send ICMP error even if DF is not set. */
 559                if (err == -EMSGSIZE)
 560                        icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 561                                  htonl(mtu));
 562                return -1;
 563        }
 564
 565        return 0;
 566}
 567
 568static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 569{
 570        struct ip6_tnl *t = netdev_priv(dev);
 571        struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 572        int encap_limit = -1;
 573        __u16 offset;
 574        struct flowi6 fl6;
 575        __u8 dsfield;
 576        __u32 mtu;
 577        int err;
 578
 579        if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
 580                return -1;
 581
 582        offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 583        /* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
 584        ipv6h = ipv6_hdr(skb);
 585
 586        if (offset > 0) {
 587                struct ipv6_tlv_tnl_enc_lim *tel;
 588                tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 589                if (tel->encap_limit == 0) {
 590                        icmpv6_send(skb, ICMPV6_PARAMPROB,
 591                                    ICMPV6_HDR_FIELD, offset + 2);
 592                        return -1;
 593                }
 594                encap_limit = tel->encap_limit - 1;
 595        } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 596                encap_limit = t->parms.encap_limit;
 597
 598        memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 599
 600        if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 601                dsfield = ipv6_get_dsfield(ipv6h);
 602        else
 603                dsfield = ip6_tclass(t->parms.flowinfo);
 604
 605        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 606                fl6.flowlabel |= ip6_flowlabel(ipv6h);
 607        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 608                fl6.flowi6_mark = skb->mark;
 609        else
 610                fl6.flowi6_mark = t->parms.fwmark;
 611
 612        fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
 613
 614        if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
 615                return -1;
 616
 617        err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
 618                          &mtu, skb->protocol);
 619        if (err != 0) {
 620                if (err == -EMSGSIZE)
 621                        icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 622                return -1;
 623        }
 624
 625        return 0;
 626}
 627
 628/**
 629 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 630 *   @t: the outgoing tunnel device
 631 *   @hdr: IPv6 header from the incoming packet
 632 *
 633 * Description:
 634 *   Avoid trivial tunneling loop by checking that tunnel exit-point
 635 *   doesn't match source of incoming packet.
 636 *
 637 * Return:
 638 *   1 if conflict,
 639 *   0 else
 640 **/
 641
 642static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
 643        const struct ipv6hdr *hdr)
 644{
 645        return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 646}
 647
 648static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 649{
 650        struct ip6_tnl *t = netdev_priv(dev);
 651        int encap_limit = -1;
 652        struct flowi6 fl6;
 653        __u32 mtu;
 654        int err;
 655
 656        if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 657                encap_limit = t->parms.encap_limit;
 658
 659        memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 660
 661        err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
 662        if (err)
 663                return err;
 664
 665        err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
 666
 667        return err;
 668}
 669
 670static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 671        struct net_device *dev)
 672{
 673        struct ip6_tnl *t = netdev_priv(dev);
 674        struct net_device_stats *stats = &t->dev->stats;
 675        int ret;
 676
 677        if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
 678                goto tx_err;
 679
 680        switch (skb->protocol) {
 681        case htons(ETH_P_IP):
 682                ret = ip6gre_xmit_ipv4(skb, dev);
 683                break;
 684        case htons(ETH_P_IPV6):
 685                ret = ip6gre_xmit_ipv6(skb, dev);
 686                break;
 687        default:
 688                ret = ip6gre_xmit_other(skb, dev);
 689                break;
 690        }
 691
 692        if (ret < 0)
 693                goto tx_err;
 694
 695        return NETDEV_TX_OK;
 696
 697tx_err:
 698        stats->tx_errors++;
 699        stats->tx_dropped++;
 700        kfree_skb(skb);
 701        return NETDEV_TX_OK;
 702}
 703
 704static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
 705{
 706        struct net_device *dev = t->dev;
 707        struct __ip6_tnl_parm *p = &t->parms;
 708        struct flowi6 *fl6 = &t->fl.u.ip6;
 709        int t_hlen;
 710
 711        if (dev->type != ARPHRD_ETHER) {
 712                memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
 713                memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
 714        }
 715
 716        /* Set up flowi template */
 717        fl6->saddr = p->laddr;
 718        fl6->daddr = p->raddr;
 719        fl6->flowi6_oif = p->link;
 720        fl6->flowlabel = 0;
 721        fl6->flowi6_proto = IPPROTO_GRE;
 722
 723        if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
 724                fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
 725        if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
 726                fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
 727
 728        p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
 729        p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
 730
 731        if (p->flags&IP6_TNL_F_CAP_XMIT &&
 732                        p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
 733                dev->flags |= IFF_POINTOPOINT;
 734        else
 735                dev->flags &= ~IFF_POINTOPOINT;
 736
 737        t->tun_hlen = gre_calc_hlen(t->parms.o_flags);
 738
 739        t->hlen = t->encap_hlen + t->tun_hlen;
 740
 741        t_hlen = t->hlen + sizeof(struct ipv6hdr);
 742
 743        if (p->flags & IP6_TNL_F_CAP_XMIT) {
 744                int strict = (ipv6_addr_type(&p->raddr) &
 745                              (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
 746
 747                struct rt6_info *rt = rt6_lookup(t->net,
 748                                                 &p->raddr, &p->laddr,
 749                                                 p->link, strict);
 750
 751                if (!rt)
 752                        return;
 753
 754                if (rt->dst.dev) {
 755                        dev->hard_header_len = rt->dst.dev->hard_header_len +
 756                                               t_hlen;
 757
 758                        if (set_mtu) {
 759                                dev->mtu = rt->dst.dev->mtu - t_hlen;
 760                                if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 761                                        dev->mtu -= 8;
 762                                if (dev->type == ARPHRD_ETHER)
 763                                        dev->mtu -= ETH_HLEN;
 764
 765                                if (dev->mtu < IPV6_MIN_MTU)
 766                                        dev->mtu = IPV6_MIN_MTU;
 767                        }
 768                }
 769                ip6_rt_put(rt);
 770        }
 771}
 772
 773static int ip6gre_tnl_change(struct ip6_tnl *t,
 774        const struct __ip6_tnl_parm *p, int set_mtu)
 775{
 776        t->parms.laddr = p->laddr;
 777        t->parms.raddr = p->raddr;
 778        t->parms.flags = p->flags;
 779        t->parms.hop_limit = p->hop_limit;
 780        t->parms.encap_limit = p->encap_limit;
 781        t->parms.flowinfo = p->flowinfo;
 782        t->parms.link = p->link;
 783        t->parms.proto = p->proto;
 784        t->parms.i_key = p->i_key;
 785        t->parms.o_key = p->o_key;
 786        t->parms.i_flags = p->i_flags;
 787        t->parms.o_flags = p->o_flags;
 788        t->parms.fwmark = p->fwmark;
 789        dst_cache_reset(&t->dst_cache);
 790        ip6gre_tnl_link_config(t, set_mtu);
 791        return 0;
 792}
 793
 794static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
 795        const struct ip6_tnl_parm2 *u)
 796{
 797        p->laddr = u->laddr;
 798        p->raddr = u->raddr;
 799        p->flags = u->flags;
 800        p->hop_limit = u->hop_limit;
 801        p->encap_limit = u->encap_limit;
 802        p->flowinfo = u->flowinfo;
 803        p->link = u->link;
 804        p->i_key = u->i_key;
 805        p->o_key = u->o_key;
 806        p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
 807        p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
 808        memcpy(p->name, u->name, sizeof(u->name));
 809}
 810
 811static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
 812        const struct __ip6_tnl_parm *p)
 813{
 814        u->proto = IPPROTO_GRE;
 815        u->laddr = p->laddr;
 816        u->raddr = p->raddr;
 817        u->flags = p->flags;
 818        u->hop_limit = p->hop_limit;
 819        u->encap_limit = p->encap_limit;
 820        u->flowinfo = p->flowinfo;
 821        u->link = p->link;
 822        u->i_key = p->i_key;
 823        u->o_key = p->o_key;
 824        u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
 825        u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
 826        memcpy(u->name, p->name, sizeof(u->name));
 827}
 828
 829static int ip6gre_tunnel_ioctl(struct net_device *dev,
 830        struct ifreq *ifr, int cmd)
 831{
 832        int err = 0;
 833        struct ip6_tnl_parm2 p;
 834        struct __ip6_tnl_parm p1;
 835        struct ip6_tnl *t = netdev_priv(dev);
 836        struct net *net = t->net;
 837        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 838
 839        memset(&p1, 0, sizeof(p1));
 840
 841        switch (cmd) {
 842        case SIOCGETTUNNEL:
 843                if (dev == ign->fb_tunnel_dev) {
 844                        if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
 845                                err = -EFAULT;
 846                                break;
 847                        }
 848                        ip6gre_tnl_parm_from_user(&p1, &p);
 849                        t = ip6gre_tunnel_locate(net, &p1, 0);
 850                        if (!t)
 851                                t = netdev_priv(dev);
 852                }
 853                memset(&p, 0, sizeof(p));
 854                ip6gre_tnl_parm_to_user(&p, &t->parms);
 855                if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
 856                        err = -EFAULT;
 857                break;
 858
 859        case SIOCADDTUNNEL:
 860        case SIOCCHGTUNNEL:
 861                err = -EPERM;
 862                if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 863                        goto done;
 864
 865                err = -EFAULT;
 866                if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 867                        goto done;
 868
 869                err = -EINVAL;
 870                if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
 871                        goto done;
 872
 873                if (!(p.i_flags&GRE_KEY))
 874                        p.i_key = 0;
 875                if (!(p.o_flags&GRE_KEY))
 876                        p.o_key = 0;
 877
 878                ip6gre_tnl_parm_from_user(&p1, &p);
 879                t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
 880
 881                if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
 882                        if (t) {
 883                                if (t->dev != dev) {
 884                                        err = -EEXIST;
 885                                        break;
 886                                }
 887                        } else {
 888                                t = netdev_priv(dev);
 889
 890                                ip6gre_tunnel_unlink(ign, t);
 891                                synchronize_net();
 892                                ip6gre_tnl_change(t, &p1, 1);
 893                                ip6gre_tunnel_link(ign, t);
 894                                netdev_state_change(dev);
 895                        }
 896                }
 897
 898                if (t) {
 899                        err = 0;
 900
 901                        memset(&p, 0, sizeof(p));
 902                        ip6gre_tnl_parm_to_user(&p, &t->parms);
 903                        if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
 904                                err = -EFAULT;
 905                } else
 906                        err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
 907                break;
 908
 909        case SIOCDELTUNNEL:
 910                err = -EPERM;
 911                if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 912                        goto done;
 913
 914                if (dev == ign->fb_tunnel_dev) {
 915                        err = -EFAULT;
 916                        if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 917                                goto done;
 918                        err = -ENOENT;
 919                        ip6gre_tnl_parm_from_user(&p1, &p);
 920                        t = ip6gre_tunnel_locate(net, &p1, 0);
 921                        if (!t)
 922                                goto done;
 923                        err = -EPERM;
 924                        if (t == netdev_priv(ign->fb_tunnel_dev))
 925                                goto done;
 926                        dev = t->dev;
 927                }
 928                unregister_netdevice(dev);
 929                err = 0;
 930                break;
 931
 932        default:
 933                err = -EINVAL;
 934        }
 935
 936done:
 937        return err;
 938}
 939
 940static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
 941                        unsigned short type,
 942                        const void *daddr, const void *saddr, unsigned int len)
 943{
 944        struct ip6_tnl *t = netdev_priv(dev);
 945        struct ipv6hdr *ipv6h = skb_push(skb, t->hlen);
 946        __be16 *p = (__be16 *)(ipv6h+1);
 947
 948        ip6_flow_hdr(ipv6h, 0,
 949                     ip6_make_flowlabel(dev_net(dev), skb,
 950                                        t->fl.u.ip6.flowlabel, true,
 951                                        &t->fl.u.ip6));
 952        ipv6h->hop_limit = t->parms.hop_limit;
 953        ipv6h->nexthdr = NEXTHDR_GRE;
 954        ipv6h->saddr = t->parms.laddr;
 955        ipv6h->daddr = t->parms.raddr;
 956
 957        p[0]            = t->parms.o_flags;
 958        p[1]            = htons(type);
 959
 960        /*
 961         *      Set the source hardware address.
 962         */
 963
 964        if (saddr)
 965                memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
 966        if (daddr)
 967                memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
 968        if (!ipv6_addr_any(&ipv6h->daddr))
 969                return t->hlen;
 970
 971        return -t->hlen;
 972}
 973
 974static const struct header_ops ip6gre_header_ops = {
 975        .create = ip6gre_header,
 976};
 977
 978static const struct net_device_ops ip6gre_netdev_ops = {
 979        .ndo_init               = ip6gre_tunnel_init,
 980        .ndo_uninit             = ip6gre_tunnel_uninit,
 981        .ndo_start_xmit         = ip6gre_tunnel_xmit,
 982        .ndo_do_ioctl           = ip6gre_tunnel_ioctl,
 983        .ndo_change_mtu         = ip6_tnl_change_mtu,
 984        .ndo_get_stats64        = ip_tunnel_get_stats64,
 985        .ndo_get_iflink         = ip6_tnl_get_iflink,
 986};
 987
 988static void ip6gre_dev_free(struct net_device *dev)
 989{
 990        struct ip6_tnl *t = netdev_priv(dev);
 991
 992        dst_cache_destroy(&t->dst_cache);
 993        free_percpu(dev->tstats);
 994}
 995
 996static void ip6gre_tunnel_setup(struct net_device *dev)
 997{
 998        dev->netdev_ops = &ip6gre_netdev_ops;
 999        dev->needs_free_netdev = true;
1000        dev->priv_destructor = ip6gre_dev_free;
1001
1002        dev->type = ARPHRD_IP6GRE;
1003
1004        dev->flags |= IFF_NOARP;
1005        dev->addr_len = sizeof(struct in6_addr);
1006        netif_keep_dst(dev);
1007        /* This perm addr will be used as interface identifier by IPv6 */
1008        dev->addr_assign_type = NET_ADDR_RANDOM;
1009        eth_random_addr(dev->perm_addr);
1010}
1011
1012static int ip6gre_tunnel_init_common(struct net_device *dev)
1013{
1014        struct ip6_tnl *tunnel;
1015        int ret;
1016        int t_hlen;
1017
1018        tunnel = netdev_priv(dev);
1019
1020        tunnel->dev = dev;
1021        tunnel->net = dev_net(dev);
1022        strcpy(tunnel->parms.name, dev->name);
1023
1024        dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1025        if (!dev->tstats)
1026                return -ENOMEM;
1027
1028        ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1029        if (ret) {
1030                free_percpu(dev->tstats);
1031                dev->tstats = NULL;
1032                return ret;
1033        }
1034
1035        tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1036        tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1037        t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1038
1039        dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1040        dev->mtu = ETH_DATA_LEN - t_hlen;
1041        if (dev->type == ARPHRD_ETHER)
1042                dev->mtu -= ETH_HLEN;
1043        if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1044                dev->mtu -= 8;
1045
1046        return 0;
1047}
1048
1049static int ip6gre_tunnel_init(struct net_device *dev)
1050{
1051        struct ip6_tnl *tunnel;
1052        int ret;
1053
1054        ret = ip6gre_tunnel_init_common(dev);
1055        if (ret)
1056                return ret;
1057
1058        tunnel = netdev_priv(dev);
1059
1060        memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1061        memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1062
1063        if (ipv6_addr_any(&tunnel->parms.raddr))
1064                dev->header_ops = &ip6gre_header_ops;
1065
1066        return 0;
1067}
1068
1069static void ip6gre_fb_tunnel_init(struct net_device *dev)
1070{
1071        struct ip6_tnl *tunnel = netdev_priv(dev);
1072
1073        tunnel->dev = dev;
1074        tunnel->net = dev_net(dev);
1075        strcpy(tunnel->parms.name, dev->name);
1076
1077        tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
1078
1079        dev_hold(dev);
1080}
1081
1082
1083static struct inet6_protocol ip6gre_protocol __read_mostly = {
1084        .handler     = gre_rcv,
1085        .err_handler = ip6gre_err,
1086        .flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1087};
1088
1089static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1090{
1091        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1092        struct net_device *dev, *aux;
1093        int prio;
1094
1095        for_each_netdev_safe(net, dev, aux)
1096                if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1097                    dev->rtnl_link_ops == &ip6gre_tap_ops)
1098                        unregister_netdevice_queue(dev, head);
1099
1100        for (prio = 0; prio < 4; prio++) {
1101                int h;
1102                for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1103                        struct ip6_tnl *t;
1104
1105                        t = rtnl_dereference(ign->tunnels[prio][h]);
1106
1107                        while (t) {
1108                                /* If dev is in the same netns, it has already
1109                                 * been added to the list by the previous loop.
1110                                 */
1111                                if (!net_eq(dev_net(t->dev), net))
1112                                        unregister_netdevice_queue(t->dev,
1113                                                                   head);
1114                                t = rtnl_dereference(t->next);
1115                        }
1116                }
1117        }
1118}
1119
1120static int __net_init ip6gre_init_net(struct net *net)
1121{
1122        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1123        int err;
1124
1125        ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1126                                          NET_NAME_UNKNOWN,
1127                                          ip6gre_tunnel_setup);
1128        if (!ign->fb_tunnel_dev) {
1129                err = -ENOMEM;
1130                goto err_alloc_dev;
1131        }
1132        dev_net_set(ign->fb_tunnel_dev, net);
1133        /* FB netdevice is special: we have one, and only one per netns.
1134         * Allowing to move it to another netns is clearly unsafe.
1135         */
1136        ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1137
1138
1139        ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1140        ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1141
1142        err = register_netdev(ign->fb_tunnel_dev);
1143        if (err)
1144                goto err_reg_dev;
1145
1146        rcu_assign_pointer(ign->tunnels_wc[0],
1147                           netdev_priv(ign->fb_tunnel_dev));
1148        return 0;
1149
1150err_reg_dev:
1151        free_netdev(ign->fb_tunnel_dev);
1152err_alloc_dev:
1153        return err;
1154}
1155
1156static void __net_exit ip6gre_exit_net(struct net *net)
1157{
1158        LIST_HEAD(list);
1159
1160        rtnl_lock();
1161        ip6gre_destroy_tunnels(net, &list);
1162        unregister_netdevice_many(&list);
1163        rtnl_unlock();
1164}
1165
1166static struct pernet_operations ip6gre_net_ops = {
1167        .init = ip6gre_init_net,
1168        .exit = ip6gre_exit_net,
1169        .id   = &ip6gre_net_id,
1170        .size = sizeof(struct ip6gre_net),
1171};
1172
1173static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1174                                  struct netlink_ext_ack *extack)
1175{
1176        __be16 flags;
1177
1178        if (!data)
1179                return 0;
1180
1181        flags = 0;
1182        if (data[IFLA_GRE_IFLAGS])
1183                flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1184        if (data[IFLA_GRE_OFLAGS])
1185                flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1186        if (flags & (GRE_VERSION|GRE_ROUTING))
1187                return -EINVAL;
1188
1189        return 0;
1190}
1191
1192static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1193                               struct netlink_ext_ack *extack)
1194{
1195        struct in6_addr daddr;
1196
1197        if (tb[IFLA_ADDRESS]) {
1198                if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1199                        return -EINVAL;
1200                if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1201                        return -EADDRNOTAVAIL;
1202        }
1203
1204        if (!data)
1205                goto out;
1206
1207        if (data[IFLA_GRE_REMOTE]) {
1208                daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1209                if (ipv6_addr_any(&daddr))
1210                        return -EINVAL;
1211        }
1212
1213out:
1214        return ip6gre_tunnel_validate(tb, data, extack);
1215}
1216
1217
1218static void ip6gre_netlink_parms(struct nlattr *data[],
1219                                struct __ip6_tnl_parm *parms)
1220{
1221        memset(parms, 0, sizeof(*parms));
1222
1223        if (!data)
1224                return;
1225
1226        if (data[IFLA_GRE_LINK])
1227                parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1228
1229        if (data[IFLA_GRE_IFLAGS])
1230                parms->i_flags = gre_flags_to_tnl_flags(
1231                                nla_get_be16(data[IFLA_GRE_IFLAGS]));
1232
1233        if (data[IFLA_GRE_OFLAGS])
1234                parms->o_flags = gre_flags_to_tnl_flags(
1235                                nla_get_be16(data[IFLA_GRE_OFLAGS]));
1236
1237        if (data[IFLA_GRE_IKEY])
1238                parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1239
1240        if (data[IFLA_GRE_OKEY])
1241                parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1242
1243        if (data[IFLA_GRE_LOCAL])
1244                parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1245
1246        if (data[IFLA_GRE_REMOTE])
1247                parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1248
1249        if (data[IFLA_GRE_TTL])
1250                parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1251
1252        if (data[IFLA_GRE_ENCAP_LIMIT])
1253                parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1254
1255        if (data[IFLA_GRE_FLOWINFO])
1256                parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1257
1258        if (data[IFLA_GRE_FLAGS])
1259                parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1260
1261        if (data[IFLA_GRE_FWMARK])
1262                parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1263}
1264
1265static int ip6gre_tap_init(struct net_device *dev)
1266{
1267        struct ip6_tnl *tunnel;
1268        int ret;
1269
1270        ret = ip6gre_tunnel_init_common(dev);
1271        if (ret)
1272                return ret;
1273
1274        dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1275
1276        tunnel = netdev_priv(dev);
1277
1278        ip6gre_tnl_link_config(tunnel, 1);
1279
1280        return 0;
1281}
1282
1283static const struct net_device_ops ip6gre_tap_netdev_ops = {
1284        .ndo_init = ip6gre_tap_init,
1285        .ndo_uninit = ip6gre_tunnel_uninit,
1286        .ndo_start_xmit = ip6gre_tunnel_xmit,
1287        .ndo_set_mac_address = eth_mac_addr,
1288        .ndo_validate_addr = eth_validate_addr,
1289        .ndo_change_mtu = ip6_tnl_change_mtu,
1290        .ndo_get_stats64 = ip_tunnel_get_stats64,
1291        .ndo_get_iflink = ip6_tnl_get_iflink,
1292};
1293
1294#define GRE6_FEATURES (NETIF_F_SG |             \
1295                       NETIF_F_FRAGLIST |       \
1296                       NETIF_F_HIGHDMA |                \
1297                       NETIF_F_HW_CSUM)
1298
1299static void ip6gre_tap_setup(struct net_device *dev)
1300{
1301
1302        ether_setup(dev);
1303
1304        dev->netdev_ops = &ip6gre_tap_netdev_ops;
1305        dev->needs_free_netdev = true;
1306        dev->priv_destructor = ip6gre_dev_free;
1307
1308        dev->features |= NETIF_F_NETNS_LOCAL;
1309        dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1310        dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1311}
1312
1313static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1314                                       struct ip_tunnel_encap *ipencap)
1315{
1316        bool ret = false;
1317
1318        memset(ipencap, 0, sizeof(*ipencap));
1319
1320        if (!data)
1321                return ret;
1322
1323        if (data[IFLA_GRE_ENCAP_TYPE]) {
1324                ret = true;
1325                ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1326        }
1327
1328        if (data[IFLA_GRE_ENCAP_FLAGS]) {
1329                ret = true;
1330                ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1331        }
1332
1333        if (data[IFLA_GRE_ENCAP_SPORT]) {
1334                ret = true;
1335                ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1336        }
1337
1338        if (data[IFLA_GRE_ENCAP_DPORT]) {
1339                ret = true;
1340                ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1341        }
1342
1343        return ret;
1344}
1345
1346static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1347                          struct nlattr *tb[], struct nlattr *data[],
1348                          struct netlink_ext_ack *extack)
1349{
1350        struct ip6_tnl *nt;
1351        struct net *net = dev_net(dev);
1352        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1353        struct ip_tunnel_encap ipencap;
1354        int err;
1355
1356        nt = netdev_priv(dev);
1357
1358        if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1359                int err = ip6_tnl_encap_setup(nt, &ipencap);
1360
1361                if (err < 0)
1362                        return err;
1363        }
1364
1365        ip6gre_netlink_parms(data, &nt->parms);
1366
1367        if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1368                return -EEXIST;
1369
1370        if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1371                eth_hw_addr_random(dev);
1372
1373        nt->dev = dev;
1374        nt->net = dev_net(dev);
1375        ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1376
1377        dev->features           |= GRE6_FEATURES;
1378        dev->hw_features        |= GRE6_FEATURES;
1379
1380        if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
1381                /* TCP offload with GRE SEQ is not supported, nor
1382                 * can we support 2 levels of outer headers requiring
1383                 * an update.
1384                 */
1385                if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
1386                    (nt->encap.type == TUNNEL_ENCAP_NONE)) {
1387                        dev->features    |= NETIF_F_GSO_SOFTWARE;
1388                        dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1389                }
1390
1391                /* Can use a lockless transmit, unless we generate
1392                 * output sequences
1393                 */
1394                dev->features |= NETIF_F_LLTX;
1395        }
1396
1397        err = register_netdevice(dev);
1398        if (err)
1399                goto out;
1400
1401        dev_hold(dev);
1402        ip6gre_tunnel_link(ign, nt);
1403
1404out:
1405        return err;
1406}
1407
1408static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1409                             struct nlattr *data[],
1410                             struct netlink_ext_ack *extack)
1411{
1412        struct ip6_tnl *t, *nt = netdev_priv(dev);
1413        struct net *net = nt->net;
1414        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1415        struct __ip6_tnl_parm p;
1416        struct ip_tunnel_encap ipencap;
1417
1418        if (dev == ign->fb_tunnel_dev)
1419                return -EINVAL;
1420
1421        if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1422                int err = ip6_tnl_encap_setup(nt, &ipencap);
1423
1424                if (err < 0)
1425                        return err;
1426        }
1427
1428        ip6gre_netlink_parms(data, &p);
1429
1430        t = ip6gre_tunnel_locate(net, &p, 0);
1431
1432        if (t) {
1433                if (t->dev != dev)
1434                        return -EEXIST;
1435        } else {
1436                t = nt;
1437        }
1438
1439        ip6gre_tunnel_unlink(ign, t);
1440        ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1441        ip6gre_tunnel_link(ign, t);
1442        return 0;
1443}
1444
1445static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1446{
1447        struct net *net = dev_net(dev);
1448        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1449
1450        if (dev != ign->fb_tunnel_dev)
1451                unregister_netdevice_queue(dev, head);
1452}
1453
1454static size_t ip6gre_get_size(const struct net_device *dev)
1455{
1456        return
1457                /* IFLA_GRE_LINK */
1458                nla_total_size(4) +
1459                /* IFLA_GRE_IFLAGS */
1460                nla_total_size(2) +
1461                /* IFLA_GRE_OFLAGS */
1462                nla_total_size(2) +
1463                /* IFLA_GRE_IKEY */
1464                nla_total_size(4) +
1465                /* IFLA_GRE_OKEY */
1466                nla_total_size(4) +
1467                /* IFLA_GRE_LOCAL */
1468                nla_total_size(sizeof(struct in6_addr)) +
1469                /* IFLA_GRE_REMOTE */
1470                nla_total_size(sizeof(struct in6_addr)) +
1471                /* IFLA_GRE_TTL */
1472                nla_total_size(1) +
1473                /* IFLA_GRE_ENCAP_LIMIT */
1474                nla_total_size(1) +
1475                /* IFLA_GRE_FLOWINFO */
1476                nla_total_size(4) +
1477                /* IFLA_GRE_FLAGS */
1478                nla_total_size(4) +
1479                /* IFLA_GRE_ENCAP_TYPE */
1480                nla_total_size(2) +
1481                /* IFLA_GRE_ENCAP_FLAGS */
1482                nla_total_size(2) +
1483                /* IFLA_GRE_ENCAP_SPORT */
1484                nla_total_size(2) +
1485                /* IFLA_GRE_ENCAP_DPORT */
1486                nla_total_size(2) +
1487                /* IFLA_GRE_FWMARK */
1488                nla_total_size(4) +
1489                0;
1490}
1491
1492static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1493{
1494        struct ip6_tnl *t = netdev_priv(dev);
1495        struct __ip6_tnl_parm *p = &t->parms;
1496
1497        if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1498            nla_put_be16(skb, IFLA_GRE_IFLAGS,
1499                         gre_tnl_flags_to_gre_flags(p->i_flags)) ||
1500            nla_put_be16(skb, IFLA_GRE_OFLAGS,
1501                         gre_tnl_flags_to_gre_flags(p->o_flags)) ||
1502            nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1503            nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1504            nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
1505            nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
1506            nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1507            nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1508            nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1509            nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
1510            nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark))
1511                goto nla_put_failure;
1512
1513        if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
1514                        t->encap.type) ||
1515            nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
1516                         t->encap.sport) ||
1517            nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
1518                         t->encap.dport) ||
1519            nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
1520                        t->encap.flags))
1521                goto nla_put_failure;
1522
1523        return 0;
1524
1525nla_put_failure:
1526        return -EMSGSIZE;
1527}
1528
1529static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1530        [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1531        [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1532        [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1533        [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1534        [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1535        [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1536        [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1537        [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1538        [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1539        [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1540        [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1541        [IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
1542        [IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
1543        [IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
1544        [IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
1545        [IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
1546};
1547
1548static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1549        .kind           = "ip6gre",
1550        .maxtype        = IFLA_GRE_MAX,
1551        .policy         = ip6gre_policy,
1552        .priv_size      = sizeof(struct ip6_tnl),
1553        .setup          = ip6gre_tunnel_setup,
1554        .validate       = ip6gre_tunnel_validate,
1555        .newlink        = ip6gre_newlink,
1556        .changelink     = ip6gre_changelink,
1557        .dellink        = ip6gre_dellink,
1558        .get_size       = ip6gre_get_size,
1559        .fill_info      = ip6gre_fill_info,
1560        .get_link_net   = ip6_tnl_get_link_net,
1561};
1562
1563static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1564        .kind           = "ip6gretap",
1565        .maxtype        = IFLA_GRE_MAX,
1566        .policy         = ip6gre_policy,
1567        .priv_size      = sizeof(struct ip6_tnl),
1568        .setup          = ip6gre_tap_setup,
1569        .validate       = ip6gre_tap_validate,
1570        .newlink        = ip6gre_newlink,
1571        .changelink     = ip6gre_changelink,
1572        .get_size       = ip6gre_get_size,
1573        .fill_info      = ip6gre_fill_info,
1574        .get_link_net   = ip6_tnl_get_link_net,
1575};
1576
1577/*
1578 *      And now the modules code and kernel interface.
1579 */
1580
1581static int __init ip6gre_init(void)
1582{
1583        int err;
1584
1585        pr_info("GRE over IPv6 tunneling driver\n");
1586
1587        err = register_pernet_device(&ip6gre_net_ops);
1588        if (err < 0)
1589                return err;
1590
1591        err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1592        if (err < 0) {
1593                pr_info("%s: can't add protocol\n", __func__);
1594                goto add_proto_failed;
1595        }
1596
1597        err = rtnl_link_register(&ip6gre_link_ops);
1598        if (err < 0)
1599                goto rtnl_link_failed;
1600
1601        err = rtnl_link_register(&ip6gre_tap_ops);
1602        if (err < 0)
1603                goto tap_ops_failed;
1604
1605out:
1606        return err;
1607
1608tap_ops_failed:
1609        rtnl_link_unregister(&ip6gre_link_ops);
1610rtnl_link_failed:
1611        inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1612add_proto_failed:
1613        unregister_pernet_device(&ip6gre_net_ops);
1614        goto out;
1615}
1616
1617static void __exit ip6gre_fini(void)
1618{
1619        rtnl_link_unregister(&ip6gre_tap_ops);
1620        rtnl_link_unregister(&ip6gre_link_ops);
1621        inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1622        unregister_pernet_device(&ip6gre_net_ops);
1623}
1624
1625module_init(ip6gre_init);
1626module_exit(ip6gre_fini);
1627MODULE_LICENSE("GPL");
1628MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1629MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1630MODULE_ALIAS_RTNL_LINK("ip6gre");
1631MODULE_ALIAS_RTNL_LINK("ip6gretap");
1632MODULE_ALIAS_NETDEV("ip6gre0");
1633