linux/net/ipv6/sit.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *      IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
   4 *      Linux INET6 implementation
   5 *
   6 *      Authors:
   7 *      Pedro Roque             <roque@di.fc.ul.pt>
   8 *      Alexey Kuznetsov        <kuznet@ms2.inr.ac.ru>
   9 *
  10 *      Changes:
  11 * Roger Venning <r.venning@telstra.com>:       6to4 support
  12 * Nate Thompson <nate@thebog.net>:             6to4 support
  13 * Fred Templin <fred.l.templin@boeing.com>:    isatap support
  14 */
  15
  16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17
  18#include <linux/module.h>
  19#include <linux/capability.h>
  20#include <linux/errno.h>
  21#include <linux/types.h>
  22#include <linux/socket.h>
  23#include <linux/sockios.h>
  24#include <linux/net.h>
  25#include <linux/in6.h>
  26#include <linux/netdevice.h>
  27#include <linux/if_arp.h>
  28#include <linux/icmp.h>
  29#include <linux/slab.h>
  30#include <linux/uaccess.h>
  31#include <linux/init.h>
  32#include <linux/netfilter_ipv4.h>
  33#include <linux/if_ether.h>
  34
  35#include <net/sock.h>
  36#include <net/snmp.h>
  37
  38#include <net/ipv6.h>
  39#include <net/protocol.h>
  40#include <net/transp_v6.h>
  41#include <net/ip6_fib.h>
  42#include <net/ip6_route.h>
  43#include <net/ndisc.h>
  44#include <net/addrconf.h>
  45#include <net/ip.h>
  46#include <net/udp.h>
  47#include <net/icmp.h>
  48#include <net/ip_tunnels.h>
  49#include <net/inet_ecn.h>
  50#include <net/xfrm.h>
  51#include <net/dsfield.h>
  52#include <net/net_namespace.h>
  53#include <net/netns/generic.h>
  54
  55/*
  56   This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
  57
  58   For comments look at net/ipv4/ip_gre.c --ANK
  59 */
  60
  61#define IP6_SIT_HASH_SIZE  16
  62#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
  63
  64static bool log_ecn_error = true;
  65module_param(log_ecn_error, bool, 0644);
  66MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  67
  68static int ipip6_tunnel_init(struct net_device *dev);
  69static void ipip6_tunnel_setup(struct net_device *dev);
  70static void ipip6_dev_free(struct net_device *dev);
  71static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
  72                      __be32 *v4dst);
  73static struct rtnl_link_ops sit_link_ops __read_mostly;
  74
  75static unsigned int sit_net_id __read_mostly;
  76struct sit_net {
  77        struct ip_tunnel __rcu *tunnels_r_l[IP6_SIT_HASH_SIZE];
  78        struct ip_tunnel __rcu *tunnels_r[IP6_SIT_HASH_SIZE];
  79        struct ip_tunnel __rcu *tunnels_l[IP6_SIT_HASH_SIZE];
  80        struct ip_tunnel __rcu *tunnels_wc[1];
  81        struct ip_tunnel __rcu **tunnels[4];
  82
  83        struct net_device *fb_tunnel_dev;
  84};
  85
  86/*
  87 * Must be invoked with rcu_read_lock
  88 */
  89static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
  90                                             struct net_device *dev,
  91                                             __be32 remote, __be32 local,
  92                                             int sifindex)
  93{
  94        unsigned int h0 = HASH(remote);
  95        unsigned int h1 = HASH(local);
  96        struct ip_tunnel *t;
  97        struct sit_net *sitn = net_generic(net, sit_net_id);
  98        int ifindex = dev ? dev->ifindex : 0;
  99
 100        for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
 101                if (local == t->parms.iph.saddr &&
 102                    remote == t->parms.iph.daddr &&
 103                    (!dev || !t->parms.link || ifindex == t->parms.link ||
 104                     sifindex == t->parms.link) &&
 105                    (t->dev->flags & IFF_UP))
 106                        return t;
 107        }
 108        for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) {
 109                if (remote == t->parms.iph.daddr &&
 110                    (!dev || !t->parms.link || ifindex == t->parms.link ||
 111                     sifindex == t->parms.link) &&
 112                    (t->dev->flags & IFF_UP))
 113                        return t;
 114        }
 115        for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
 116                if (local == t->parms.iph.saddr &&
 117                    (!dev || !t->parms.link || ifindex == t->parms.link ||
 118                     sifindex == t->parms.link) &&
 119                    (t->dev->flags & IFF_UP))
 120                        return t;
 121        }
 122        t = rcu_dereference(sitn->tunnels_wc[0]);
 123        if (t && (t->dev->flags & IFF_UP))
 124                return t;
 125        return NULL;
 126}
 127
 128static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
 129                struct ip_tunnel_parm *parms)
 130{
 131        __be32 remote = parms->iph.daddr;
 132        __be32 local = parms->iph.saddr;
 133        unsigned int h = 0;
 134        int prio = 0;
 135
 136        if (remote) {
 137                prio |= 2;
 138                h ^= HASH(remote);
 139        }
 140        if (local) {
 141                prio |= 1;
 142                h ^= HASH(local);
 143        }
 144        return &sitn->tunnels[prio][h];
 145}
 146
 147static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
 148                struct ip_tunnel *t)
 149{
 150        return __ipip6_bucket(sitn, &t->parms);
 151}
 152
 153static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
 154{
 155        struct ip_tunnel __rcu **tp;
 156        struct ip_tunnel *iter;
 157
 158        for (tp = ipip6_bucket(sitn, t);
 159             (iter = rtnl_dereference(*tp)) != NULL;
 160             tp = &iter->next) {
 161                if (t == iter) {
 162                        rcu_assign_pointer(*tp, t->next);
 163                        break;
 164                }
 165        }
 166}
 167
 168static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
 169{
 170        struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
 171
 172        rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 173        rcu_assign_pointer(*tp, t);
 174}
 175
 176static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
 177{
 178#ifdef CONFIG_IPV6_SIT_6RD
 179        struct ip_tunnel *t = netdev_priv(dev);
 180
 181        if (dev == sitn->fb_tunnel_dev || !sitn->fb_tunnel_dev) {
 182                ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
 183                t->ip6rd.relay_prefix = 0;
 184                t->ip6rd.prefixlen = 16;
 185                t->ip6rd.relay_prefixlen = 0;
 186        } else {
 187                struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
 188                memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
 189        }
 190#endif
 191}
 192
 193static int ipip6_tunnel_create(struct net_device *dev)
 194{
 195        struct ip_tunnel *t = netdev_priv(dev);
 196        struct net *net = dev_net(dev);
 197        struct sit_net *sitn = net_generic(net, sit_net_id);
 198        int err;
 199
 200        memcpy(dev->dev_addr, &t->parms.iph.saddr, 4);
 201        memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
 202
 203        if ((__force u16)t->parms.i_flags & SIT_ISATAP)
 204                dev->priv_flags |= IFF_ISATAP;
 205
 206        dev->rtnl_link_ops = &sit_link_ops;
 207
 208        err = register_netdevice(dev);
 209        if (err < 0)
 210                goto out;
 211
 212        ipip6_tunnel_clone_6rd(dev, sitn);
 213
 214        dev_hold(dev);
 215
 216        ipip6_tunnel_link(sitn, t);
 217        return 0;
 218
 219out:
 220        return err;
 221}
 222
 223static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
 224                struct ip_tunnel_parm *parms, int create)
 225{
 226        __be32 remote = parms->iph.daddr;
 227        __be32 local = parms->iph.saddr;
 228        struct ip_tunnel *t, *nt;
 229        struct ip_tunnel __rcu **tp;
 230        struct net_device *dev;
 231        char name[IFNAMSIZ];
 232        struct sit_net *sitn = net_generic(net, sit_net_id);
 233
 234        for (tp = __ipip6_bucket(sitn, parms);
 235            (t = rtnl_dereference(*tp)) != NULL;
 236             tp = &t->next) {
 237                if (local == t->parms.iph.saddr &&
 238                    remote == t->parms.iph.daddr &&
 239                    parms->link == t->parms.link) {
 240                        if (create)
 241                                return NULL;
 242                        else
 243                                return t;
 244                }
 245        }
 246        if (!create)
 247                goto failed;
 248
 249        if (parms->name[0]) {
 250                if (!dev_valid_name(parms->name))
 251                        goto failed;
 252                strlcpy(name, parms->name, IFNAMSIZ);
 253        } else {
 254                strcpy(name, "sit%d");
 255        }
 256        dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 257                           ipip6_tunnel_setup);
 258        if (!dev)
 259                return NULL;
 260
 261        dev_net_set(dev, net);
 262
 263        nt = netdev_priv(dev);
 264
 265        nt->parms = *parms;
 266        if (ipip6_tunnel_create(dev) < 0)
 267                goto failed_free;
 268
 269        return nt;
 270
 271failed_free:
 272        free_netdev(dev);
 273failed:
 274        return NULL;
 275}
 276
 277#define for_each_prl_rcu(start)                 \
 278        for (prl = rcu_dereference(start);      \
 279             prl;                               \
 280             prl = rcu_dereference(prl->next))
 281
 282static struct ip_tunnel_prl_entry *
 283__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
 284{
 285        struct ip_tunnel_prl_entry *prl;
 286
 287        for_each_prl_rcu(t->prl)
 288                if (prl->addr == addr)
 289                        break;
 290        return prl;
 291
 292}
 293
 294static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
 295                                struct ip_tunnel_prl __user *a)
 296{
 297        struct ip_tunnel_prl kprl, *kp;
 298        struct ip_tunnel_prl_entry *prl;
 299        unsigned int cmax, c = 0, ca, len;
 300        int ret = 0;
 301
 302        if (copy_from_user(&kprl, a, sizeof(kprl)))
 303                return -EFAULT;
 304        cmax = kprl.datalen / sizeof(kprl);
 305        if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
 306                cmax = 1;
 307
 308        /* For simple GET or for root users,
 309         * we try harder to allocate.
 310         */
 311        kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
 312                kcalloc(cmax, sizeof(*kp), GFP_KERNEL | __GFP_NOWARN) :
 313                NULL;
 314
 315        rcu_read_lock();
 316
 317        ca = t->prl_count < cmax ? t->prl_count : cmax;
 318
 319        if (!kp) {
 320                /* We don't try hard to allocate much memory for
 321                 * non-root users.
 322                 * For root users, retry allocating enough memory for
 323                 * the answer.
 324                 */
 325                kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
 326                if (!kp) {
 327                        ret = -ENOMEM;
 328                        goto out;
 329                }
 330        }
 331
 332        c = 0;
 333        for_each_prl_rcu(t->prl) {
 334                if (c >= cmax)
 335                        break;
 336                if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
 337                        continue;
 338                kp[c].addr = prl->addr;
 339                kp[c].flags = prl->flags;
 340                c++;
 341                if (kprl.addr != htonl(INADDR_ANY))
 342                        break;
 343        }
 344out:
 345        rcu_read_unlock();
 346
 347        len = sizeof(*kp) * c;
 348        ret = 0;
 349        if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
 350                ret = -EFAULT;
 351
 352        kfree(kp);
 353
 354        return ret;
 355}
 356
 357static int
 358ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
 359{
 360        struct ip_tunnel_prl_entry *p;
 361        int err = 0;
 362
 363        if (a->addr == htonl(INADDR_ANY))
 364                return -EINVAL;
 365
 366        ASSERT_RTNL();
 367
 368        for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
 369                if (p->addr == a->addr) {
 370                        if (chg) {
 371                                p->flags = a->flags;
 372                                goto out;
 373                        }
 374                        err = -EEXIST;
 375                        goto out;
 376                }
 377        }
 378
 379        if (chg) {
 380                err = -ENXIO;
 381                goto out;
 382        }
 383
 384        p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
 385        if (!p) {
 386                err = -ENOBUFS;
 387                goto out;
 388        }
 389
 390        p->next = t->prl;
 391        p->addr = a->addr;
 392        p->flags = a->flags;
 393        t->prl_count++;
 394        rcu_assign_pointer(t->prl, p);
 395out:
 396        return err;
 397}
 398
 399static void prl_list_destroy_rcu(struct rcu_head *head)
 400{
 401        struct ip_tunnel_prl_entry *p, *n;
 402
 403        p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
 404        do {
 405                n = rcu_dereference_protected(p->next, 1);
 406                kfree(p);
 407                p = n;
 408        } while (p);
 409}
 410
 411static int
 412ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
 413{
 414        struct ip_tunnel_prl_entry *x;
 415        struct ip_tunnel_prl_entry __rcu **p;
 416        int err = 0;
 417
 418        ASSERT_RTNL();
 419
 420        if (a && a->addr != htonl(INADDR_ANY)) {
 421                for (p = &t->prl;
 422                     (x = rtnl_dereference(*p)) != NULL;
 423                     p = &x->next) {
 424                        if (x->addr == a->addr) {
 425                                *p = x->next;
 426                                kfree_rcu(x, rcu_head);
 427                                t->prl_count--;
 428                                goto out;
 429                        }
 430                }
 431                err = -ENXIO;
 432        } else {
 433                x = rtnl_dereference(t->prl);
 434                if (x) {
 435                        t->prl_count = 0;
 436                        call_rcu(&x->rcu_head, prl_list_destroy_rcu);
 437                        t->prl = NULL;
 438                }
 439        }
 440out:
 441        return err;
 442}
 443
 444static int
 445isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
 446{
 447        struct ip_tunnel_prl_entry *p;
 448        int ok = 1;
 449
 450        rcu_read_lock();
 451        p = __ipip6_tunnel_locate_prl(t, iph->saddr);
 452        if (p) {
 453                if (p->flags & PRL_DEFAULT)
 454                        skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
 455                else
 456                        skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
 457        } else {
 458                const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
 459
 460                if (ipv6_addr_is_isatap(addr6) &&
 461                    (addr6->s6_addr32[3] == iph->saddr) &&
 462                    ipv6_chk_prefix(addr6, t->dev))
 463                        skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
 464                else
 465                        ok = 0;
 466        }
 467        rcu_read_unlock();
 468        return ok;
 469}
 470
 471static void ipip6_tunnel_uninit(struct net_device *dev)
 472{
 473        struct ip_tunnel *tunnel = netdev_priv(dev);
 474        struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
 475
 476        if (dev == sitn->fb_tunnel_dev) {
 477                RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
 478        } else {
 479                ipip6_tunnel_unlink(sitn, tunnel);
 480                ipip6_tunnel_del_prl(tunnel, NULL);
 481        }
 482        dst_cache_reset(&tunnel->dst_cache);
 483        dev_put(dev);
 484}
 485
 486static int ipip6_err(struct sk_buff *skb, u32 info)
 487{
 488        const struct iphdr *iph = (const struct iphdr *)skb->data;
 489        const int type = icmp_hdr(skb)->type;
 490        const int code = icmp_hdr(skb)->code;
 491        unsigned int data_len = 0;
 492        struct ip_tunnel *t;
 493        int sifindex;
 494        int err;
 495
 496        switch (type) {
 497        default:
 498        case ICMP_PARAMETERPROB:
 499                return 0;
 500
 501        case ICMP_DEST_UNREACH:
 502                switch (code) {
 503                case ICMP_SR_FAILED:
 504                        /* Impossible event. */
 505                        return 0;
 506                default:
 507                        /* All others are translated to HOST_UNREACH.
 508                           rfc2003 contains "deep thoughts" about NET_UNREACH,
 509                           I believe they are just ether pollution. --ANK
 510                         */
 511                        break;
 512                }
 513                break;
 514        case ICMP_TIME_EXCEEDED:
 515                if (code != ICMP_EXC_TTL)
 516                        return 0;
 517                data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
 518                break;
 519        case ICMP_REDIRECT:
 520                break;
 521        }
 522
 523        err = -ENOENT;
 524
 525        sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
 526        t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 527                                iph->daddr, iph->saddr, sifindex);
 528        if (!t)
 529                goto out;
 530
 531        if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
 532                ipv4_update_pmtu(skb, dev_net(skb->dev), info,
 533                                 t->parms.link, iph->protocol);
 534                err = 0;
 535                goto out;
 536        }
 537        if (type == ICMP_REDIRECT) {
 538                ipv4_redirect(skb, dev_net(skb->dev), t->parms.link,
 539                              iph->protocol);
 540                err = 0;
 541                goto out;
 542        }
 543
 544        err = 0;
 545        if (__in6_dev_get(skb->dev) &&
 546            !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
 547                goto out;
 548
 549        if (t->parms.iph.daddr == 0)
 550                goto out;
 551
 552        if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
 553                goto out;
 554
 555        if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
 556                t->err_count++;
 557        else
 558                t->err_count = 1;
 559        t->err_time = jiffies;
 560out:
 561        return err;
 562}
 563
 564static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
 565                                  const struct in6_addr *v6addr)
 566{
 567        __be32 v4embed = 0;
 568        if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
 569                return true;
 570        return false;
 571}
 572
 573/* Checks if an address matches an address on the tunnel interface.
 574 * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
 575 * Long story:
 576 * This function is called after we considered the packet as spoofed
 577 * in is_spoofed_6rd.
 578 * We may have a router that is doing NAT for proto 41 packets
 579 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
 580 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
 581 * function will return true, dropping the packet.
 582 * But, we can still check if is spoofed against the IP
 583 * addresses associated with the interface.
 584 */
 585static bool only_dnatted(const struct ip_tunnel *tunnel,
 586        const struct in6_addr *v6dst)
 587{
 588        int prefix_len;
 589
 590#ifdef CONFIG_IPV6_SIT_6RD
 591        prefix_len = tunnel->ip6rd.prefixlen + 32
 592                - tunnel->ip6rd.relay_prefixlen;
 593#else
 594        prefix_len = 48;
 595#endif
 596        return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
 597}
 598
 599/* Returns true if a packet is spoofed */
 600static bool packet_is_spoofed(struct sk_buff *skb,
 601                              const struct iphdr *iph,
 602                              struct ip_tunnel *tunnel)
 603{
 604        const struct ipv6hdr *ipv6h;
 605
 606        if (tunnel->dev->priv_flags & IFF_ISATAP) {
 607                if (!isatap_chksrc(skb, iph, tunnel))
 608                        return true;
 609
 610                return false;
 611        }
 612
 613        if (tunnel->dev->flags & IFF_POINTOPOINT)
 614                return false;
 615
 616        ipv6h = ipv6_hdr(skb);
 617
 618        if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
 619                net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
 620                                     &iph->saddr, &ipv6h->saddr,
 621                                     &iph->daddr, &ipv6h->daddr);
 622                return true;
 623        }
 624
 625        if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
 626                return false;
 627
 628        if (only_dnatted(tunnel, &ipv6h->daddr))
 629                return false;
 630
 631        net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
 632                             &iph->saddr, &ipv6h->saddr,
 633                             &iph->daddr, &ipv6h->daddr);
 634        return true;
 635}
 636
 637static int ipip6_rcv(struct sk_buff *skb)
 638{
 639        const struct iphdr *iph = ip_hdr(skb);
 640        struct ip_tunnel *tunnel;
 641        int sifindex;
 642        int err;
 643
 644        sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
 645        tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 646                                     iph->saddr, iph->daddr, sifindex);
 647        if (tunnel) {
 648                struct pcpu_sw_netstats *tstats;
 649
 650                if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
 651                    tunnel->parms.iph.protocol != 0)
 652                        goto out;
 653
 654                skb->mac_header = skb->network_header;
 655                skb_reset_network_header(skb);
 656                IPCB(skb)->flags = 0;
 657                skb->dev = tunnel->dev;
 658
 659                if (packet_is_spoofed(skb, iph, tunnel)) {
 660                        tunnel->dev->stats.rx_errors++;
 661                        goto out;
 662                }
 663
 664                if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
 665                    !net_eq(tunnel->net, dev_net(tunnel->dev))))
 666                        goto out;
 667
 668                /* skb can be uncloned in iptunnel_pull_header, so
 669                 * old iph is no longer valid
 670                 */
 671                iph = (const struct iphdr *)skb_mac_header(skb);
 672                err = IP_ECN_decapsulate(iph, skb);
 673                if (unlikely(err)) {
 674                        if (log_ecn_error)
 675                                net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
 676                                                     &iph->saddr, iph->tos);
 677                        if (err > 1) {
 678                                ++tunnel->dev->stats.rx_frame_errors;
 679                                ++tunnel->dev->stats.rx_errors;
 680                                goto out;
 681                        }
 682                }
 683
 684                tstats = this_cpu_ptr(tunnel->dev->tstats);
 685                u64_stats_update_begin(&tstats->syncp);
 686                tstats->rx_packets++;
 687                tstats->rx_bytes += skb->len;
 688                u64_stats_update_end(&tstats->syncp);
 689
 690                netif_rx(skb);
 691
 692                return 0;
 693        }
 694
 695        /* no tunnel matched,  let upstream know, ipsec may handle it */
 696        return 1;
 697out:
 698        kfree_skb(skb);
 699        return 0;
 700}
 701
 702static const struct tnl_ptk_info ipip_tpi = {
 703        /* no tunnel info required for ipip. */
 704        .proto = htons(ETH_P_IP),
 705};
 706
 707#if IS_ENABLED(CONFIG_MPLS)
 708static const struct tnl_ptk_info mplsip_tpi = {
 709        /* no tunnel info required for mplsip. */
 710        .proto = htons(ETH_P_MPLS_UC),
 711};
 712#endif
 713
 714static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
 715{
 716        const struct iphdr *iph;
 717        struct ip_tunnel *tunnel;
 718        int sifindex;
 719
 720        sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
 721
 722        iph = ip_hdr(skb);
 723        tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 724                                     iph->saddr, iph->daddr, sifindex);
 725        if (tunnel) {
 726                const struct tnl_ptk_info *tpi;
 727
 728                if (tunnel->parms.iph.protocol != ipproto &&
 729                    tunnel->parms.iph.protocol != 0)
 730                        goto drop;
 731
 732                if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
 733                        goto drop;
 734#if IS_ENABLED(CONFIG_MPLS)
 735                if (ipproto == IPPROTO_MPLS)
 736                        tpi = &mplsip_tpi;
 737                else
 738#endif
 739                        tpi = &ipip_tpi;
 740                if (iptunnel_pull_header(skb, 0, tpi->proto, false))
 741                        goto drop;
 742                return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
 743        }
 744
 745        return 1;
 746
 747drop:
 748        kfree_skb(skb);
 749        return 0;
 750}
 751
 752static int ipip_rcv(struct sk_buff *skb)
 753{
 754        return sit_tunnel_rcv(skb, IPPROTO_IPIP);
 755}
 756
 757#if IS_ENABLED(CONFIG_MPLS)
 758static int mplsip_rcv(struct sk_buff *skb)
 759{
 760        return sit_tunnel_rcv(skb, IPPROTO_MPLS);
 761}
 762#endif
 763
 764/*
 765 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
 766 * stores the embedded IPv4 address in v4dst and returns true.
 767 */
 768static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
 769                      __be32 *v4dst)
 770{
 771#ifdef CONFIG_IPV6_SIT_6RD
 772        if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
 773                              tunnel->ip6rd.prefixlen)) {
 774                unsigned int pbw0, pbi0;
 775                int pbi1;
 776                u32 d;
 777
 778                pbw0 = tunnel->ip6rd.prefixlen >> 5;
 779                pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
 780
 781                d = tunnel->ip6rd.relay_prefixlen < 32 ?
 782                        (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
 783                    tunnel->ip6rd.relay_prefixlen : 0;
 784
 785                pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
 786                if (pbi1 > 0)
 787                        d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
 788                             (32 - pbi1);
 789
 790                *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
 791                return true;
 792        }
 793#else
 794        if (v6dst->s6_addr16[0] == htons(0x2002)) {
 795                /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
 796                memcpy(v4dst, &v6dst->s6_addr16[1], 4);
 797                return true;
 798        }
 799#endif
 800        return false;
 801}
 802
 803static inline __be32 try_6rd(struct ip_tunnel *tunnel,
 804                             const struct in6_addr *v6dst)
 805{
 806        __be32 dst = 0;
 807        check_6rd(tunnel, v6dst, &dst);
 808        return dst;
 809}
 810
 811/*
 812 *      This function assumes it is being called from dev_queue_xmit()
 813 *      and that skb is filled properly by that function.
 814 */
 815
 816static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 817                                     struct net_device *dev)
 818{
 819        struct ip_tunnel *tunnel = netdev_priv(dev);
 820        const struct iphdr  *tiph = &tunnel->parms.iph;
 821        const struct ipv6hdr *iph6 = ipv6_hdr(skb);
 822        u8     tos = tunnel->parms.iph.tos;
 823        __be16 df = tiph->frag_off;
 824        struct rtable *rt;              /* Route to the other host */
 825        struct net_device *tdev;        /* Device to other host */
 826        unsigned int max_headroom;      /* The extra header space needed */
 827        __be32 dst = tiph->daddr;
 828        struct flowi4 fl4;
 829        int    mtu;
 830        const struct in6_addr *addr6;
 831        int addr_type;
 832        u8 ttl;
 833        u8 protocol = IPPROTO_IPV6;
 834        int t_hlen = tunnel->hlen + sizeof(struct iphdr);
 835
 836        if (tos == 1)
 837                tos = ipv6_get_dsfield(iph6);
 838
 839        /* ISATAP (RFC4214) - must come before 6to4 */
 840        if (dev->priv_flags & IFF_ISATAP) {
 841                struct neighbour *neigh = NULL;
 842                bool do_tx_error = false;
 843
 844                if (skb_dst(skb))
 845                        neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 846
 847                if (!neigh) {
 848                        net_dbg_ratelimited("nexthop == NULL\n");
 849                        goto tx_error;
 850                }
 851
 852                addr6 = (const struct in6_addr *)&neigh->primary_key;
 853                addr_type = ipv6_addr_type(addr6);
 854
 855                if ((addr_type & IPV6_ADDR_UNICAST) &&
 856                     ipv6_addr_is_isatap(addr6))
 857                        dst = addr6->s6_addr32[3];
 858                else
 859                        do_tx_error = true;
 860
 861                neigh_release(neigh);
 862                if (do_tx_error)
 863                        goto tx_error;
 864        }
 865
 866        if (!dst)
 867                dst = try_6rd(tunnel, &iph6->daddr);
 868
 869        if (!dst) {
 870                struct neighbour *neigh = NULL;
 871                bool do_tx_error = false;
 872
 873                if (skb_dst(skb))
 874                        neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 875
 876                if (!neigh) {
 877                        net_dbg_ratelimited("nexthop == NULL\n");
 878                        goto tx_error;
 879                }
 880
 881                addr6 = (const struct in6_addr *)&neigh->primary_key;
 882                addr_type = ipv6_addr_type(addr6);
 883
 884                if (addr_type == IPV6_ADDR_ANY) {
 885                        addr6 = &ipv6_hdr(skb)->daddr;
 886                        addr_type = ipv6_addr_type(addr6);
 887                }
 888
 889                if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
 890                        dst = addr6->s6_addr32[3];
 891                else
 892                        do_tx_error = true;
 893
 894                neigh_release(neigh);
 895                if (do_tx_error)
 896                        goto tx_error;
 897        }
 898
 899        flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark,
 900                           RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
 901                           0, dst, tiph->saddr, 0, 0,
 902                           sock_net_uid(tunnel->net, NULL));
 903
 904        rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr);
 905        if (!rt) {
 906                rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
 907                if (IS_ERR(rt)) {
 908                        dev->stats.tx_carrier_errors++;
 909                        goto tx_error_icmp;
 910                }
 911                dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr);
 912        }
 913
 914        if (rt->rt_type != RTN_UNICAST) {
 915                ip_rt_put(rt);
 916                dev->stats.tx_carrier_errors++;
 917                goto tx_error_icmp;
 918        }
 919        tdev = rt->dst.dev;
 920
 921        if (tdev == dev) {
 922                ip_rt_put(rt);
 923                dev->stats.collisions++;
 924                goto tx_error;
 925        }
 926
 927        if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
 928                ip_rt_put(rt);
 929                goto tx_error;
 930        }
 931
 932        if (df) {
 933                mtu = dst_mtu(&rt->dst) - t_hlen;
 934
 935                if (mtu < 68) {
 936                        dev->stats.collisions++;
 937                        ip_rt_put(rt);
 938                        goto tx_error;
 939                }
 940
 941                if (mtu < IPV6_MIN_MTU) {
 942                        mtu = IPV6_MIN_MTU;
 943                        df = 0;
 944                }
 945
 946                if (tunnel->parms.iph.daddr)
 947                        skb_dst_update_pmtu(skb, mtu);
 948
 949                if (skb->len > mtu && !skb_is_gso(skb)) {
 950                        icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 951                        ip_rt_put(rt);
 952                        goto tx_error;
 953                }
 954        }
 955
 956        if (tunnel->err_count > 0) {
 957                if (time_before(jiffies,
 958                                tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
 959                        tunnel->err_count--;
 960                        dst_link_failure(skb);
 961                } else
 962                        tunnel->err_count = 0;
 963        }
 964
 965        /*
 966         * Okay, now see if we can stuff it in the buffer as-is.
 967         */
 968        max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
 969
 970        if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 971            (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 972                struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
 973                if (!new_skb) {
 974                        ip_rt_put(rt);
 975                        dev->stats.tx_dropped++;
 976                        kfree_skb(skb);
 977                        return NETDEV_TX_OK;
 978                }
 979                if (skb->sk)
 980                        skb_set_owner_w(new_skb, skb->sk);
 981                dev_kfree_skb(skb);
 982                skb = new_skb;
 983                iph6 = ipv6_hdr(skb);
 984        }
 985        ttl = tiph->ttl;
 986        if (ttl == 0)
 987                ttl = iph6->hop_limit;
 988        tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
 989
 990        if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) {
 991                ip_rt_put(rt);
 992                goto tx_error;
 993        }
 994
 995        skb_set_inner_ipproto(skb, IPPROTO_IPV6);
 996
 997        iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
 998                      df, !net_eq(tunnel->net, dev_net(dev)));
 999        return NETDEV_TX_OK;
1000
1001tx_error_icmp:
1002        dst_link_failure(skb);
1003tx_error:
1004        kfree_skb(skb);
1005        dev->stats.tx_errors++;
1006        return NETDEV_TX_OK;
1007}
1008
1009static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
1010                                     struct net_device *dev, u8 ipproto)
1011{
1012        struct ip_tunnel *tunnel = netdev_priv(dev);
1013        const struct iphdr  *tiph = &tunnel->parms.iph;
1014
1015        if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
1016                goto tx_error;
1017
1018        skb_set_inner_ipproto(skb, ipproto);
1019
1020        ip_tunnel_xmit(skb, dev, tiph, ipproto);
1021        return NETDEV_TX_OK;
1022tx_error:
1023        kfree_skb(skb);
1024        dev->stats.tx_errors++;
1025        return NETDEV_TX_OK;
1026}
1027
1028static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1029                                   struct net_device *dev)
1030{
1031        if (!pskb_inet_may_pull(skb))
1032                goto tx_err;
1033
1034        switch (skb->protocol) {
1035        case htons(ETH_P_IP):
1036                sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
1037                break;
1038        case htons(ETH_P_IPV6):
1039                ipip6_tunnel_xmit(skb, dev);
1040                break;
1041#if IS_ENABLED(CONFIG_MPLS)
1042        case htons(ETH_P_MPLS_UC):
1043                sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
1044                break;
1045#endif
1046        default:
1047                goto tx_err;
1048        }
1049
1050        return NETDEV_TX_OK;
1051
1052tx_err:
1053        dev->stats.tx_errors++;
1054        kfree_skb(skb);
1055        return NETDEV_TX_OK;
1056
1057}
1058
1059static void ipip6_tunnel_bind_dev(struct net_device *dev)
1060{
1061        struct net_device *tdev = NULL;
1062        struct ip_tunnel *tunnel;
1063        const struct iphdr *iph;
1064        struct flowi4 fl4;
1065
1066        tunnel = netdev_priv(dev);
1067        iph = &tunnel->parms.iph;
1068
1069        if (iph->daddr) {
1070                struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1071                                                          NULL,
1072                                                          iph->daddr, iph->saddr,
1073                                                          0, 0,
1074                                                          IPPROTO_IPV6,
1075                                                          RT_TOS(iph->tos),
1076                                                          tunnel->parms.link);
1077
1078                if (!IS_ERR(rt)) {
1079                        tdev = rt->dst.dev;
1080                        ip_rt_put(rt);
1081                }
1082                dev->flags |= IFF_POINTOPOINT;
1083        }
1084
1085        if (!tdev && tunnel->parms.link)
1086                tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1087
1088        if (tdev && !netif_is_l3_master(tdev)) {
1089                int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1090
1091                dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
1092                dev->mtu = tdev->mtu - t_hlen;
1093                if (dev->mtu < IPV6_MIN_MTU)
1094                        dev->mtu = IPV6_MIN_MTU;
1095        }
1096}
1097
1098static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p,
1099                                __u32 fwmark)
1100{
1101        struct net *net = t->net;
1102        struct sit_net *sitn = net_generic(net, sit_net_id);
1103
1104        ipip6_tunnel_unlink(sitn, t);
1105        synchronize_net();
1106        t->parms.iph.saddr = p->iph.saddr;
1107        t->parms.iph.daddr = p->iph.daddr;
1108        memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
1109        memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1110        ipip6_tunnel_link(sitn, t);
1111        t->parms.iph.ttl = p->iph.ttl;
1112        t->parms.iph.tos = p->iph.tos;
1113        t->parms.iph.frag_off = p->iph.frag_off;
1114        if (t->parms.link != p->link || t->fwmark != fwmark) {
1115                t->parms.link = p->link;
1116                t->fwmark = fwmark;
1117                ipip6_tunnel_bind_dev(t->dev);
1118        }
1119        dst_cache_reset(&t->dst_cache);
1120        netdev_state_change(t->dev);
1121}
1122
1123#ifdef CONFIG_IPV6_SIT_6RD
1124static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1125                                   struct ip_tunnel_6rd *ip6rd)
1126{
1127        struct in6_addr prefix;
1128        __be32 relay_prefix;
1129
1130        if (ip6rd->relay_prefixlen > 32 ||
1131            ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1132                return -EINVAL;
1133
1134        ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1135        if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1136                return -EINVAL;
1137        if (ip6rd->relay_prefixlen)
1138                relay_prefix = ip6rd->relay_prefix &
1139                               htonl(0xffffffffUL <<
1140                                     (32 - ip6rd->relay_prefixlen));
1141        else
1142                relay_prefix = 0;
1143        if (relay_prefix != ip6rd->relay_prefix)
1144                return -EINVAL;
1145
1146        t->ip6rd.prefix = prefix;
1147        t->ip6rd.relay_prefix = relay_prefix;
1148        t->ip6rd.prefixlen = ip6rd->prefixlen;
1149        t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1150        dst_cache_reset(&t->dst_cache);
1151        netdev_state_change(t->dev);
1152        return 0;
1153}
1154#endif
1155
1156static bool ipip6_valid_ip_proto(u8 ipproto)
1157{
1158        return ipproto == IPPROTO_IPV6 ||
1159                ipproto == IPPROTO_IPIP ||
1160#if IS_ENABLED(CONFIG_MPLS)
1161                ipproto == IPPROTO_MPLS ||
1162#endif
1163                ipproto == 0;
1164}
1165
1166static int
1167ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1168{
1169        int err = 0;
1170        struct ip_tunnel_parm p;
1171        struct ip_tunnel_prl prl;
1172        struct ip_tunnel *t = netdev_priv(dev);
1173        struct net *net = t->net;
1174        struct sit_net *sitn = net_generic(net, sit_net_id);
1175#ifdef CONFIG_IPV6_SIT_6RD
1176        struct ip_tunnel_6rd ip6rd;
1177#endif
1178
1179        switch (cmd) {
1180        case SIOCGETTUNNEL:
1181#ifdef CONFIG_IPV6_SIT_6RD
1182        case SIOCGET6RD:
1183#endif
1184                if (dev == sitn->fb_tunnel_dev) {
1185                        if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1186                                err = -EFAULT;
1187                                break;
1188                        }
1189                        t = ipip6_tunnel_locate(net, &p, 0);
1190                        if (!t)
1191                                t = netdev_priv(dev);
1192                }
1193
1194                err = -EFAULT;
1195                if (cmd == SIOCGETTUNNEL) {
1196                        memcpy(&p, &t->parms, sizeof(p));
1197                        if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
1198                                         sizeof(p)))
1199                                goto done;
1200#ifdef CONFIG_IPV6_SIT_6RD
1201                } else {
1202                        ip6rd.prefix = t->ip6rd.prefix;
1203                        ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1204                        ip6rd.prefixlen = t->ip6rd.prefixlen;
1205                        ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1206                        if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
1207                                         sizeof(ip6rd)))
1208                                goto done;
1209#endif
1210                }
1211                err = 0;
1212                break;
1213
1214        case SIOCADDTUNNEL:
1215        case SIOCCHGTUNNEL:
1216                err = -EPERM;
1217                if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1218                        goto done;
1219
1220                err = -EFAULT;
1221                if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1222                        goto done;
1223
1224                err = -EINVAL;
1225                if (!ipip6_valid_ip_proto(p.iph.protocol))
1226                        goto done;
1227                if (p.iph.version != 4 ||
1228                    p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
1229                        goto done;
1230                if (p.iph.ttl)
1231                        p.iph.frag_off |= htons(IP_DF);
1232
1233                t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1234
1235                if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1236                        if (t) {
1237                                if (t->dev != dev) {
1238                                        err = -EEXIST;
1239                                        break;
1240                                }
1241                        } else {
1242                                if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
1243                                    (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
1244                                        err = -EINVAL;
1245                                        break;
1246                                }
1247                                t = netdev_priv(dev);
1248                        }
1249
1250                        ipip6_tunnel_update(t, &p, t->fwmark);
1251                }
1252
1253                if (t) {
1254                        err = 0;
1255                        if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1256                                err = -EFAULT;
1257                } else
1258                        err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1259                break;
1260
1261        case SIOCDELTUNNEL:
1262                err = -EPERM;
1263                if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1264                        goto done;
1265
1266                if (dev == sitn->fb_tunnel_dev) {
1267                        err = -EFAULT;
1268                        if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1269                                goto done;
1270                        err = -ENOENT;
1271                        t = ipip6_tunnel_locate(net, &p, 0);
1272                        if (!t)
1273                                goto done;
1274                        err = -EPERM;
1275                        if (t == netdev_priv(sitn->fb_tunnel_dev))
1276                                goto done;
1277                        dev = t->dev;
1278                }
1279                unregister_netdevice(dev);
1280                err = 0;
1281                break;
1282
1283        case SIOCGETPRL:
1284                err = -EINVAL;
1285                if (dev == sitn->fb_tunnel_dev)
1286                        goto done;
1287                err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1288                break;
1289
1290        case SIOCADDPRL:
1291        case SIOCDELPRL:
1292        case SIOCCHGPRL:
1293                err = -EPERM;
1294                if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1295                        goto done;
1296                err = -EINVAL;
1297                if (dev == sitn->fb_tunnel_dev)
1298                        goto done;
1299                err = -EFAULT;
1300                if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1301                        goto done;
1302
1303                switch (cmd) {
1304                case SIOCDELPRL:
1305                        err = ipip6_tunnel_del_prl(t, &prl);
1306                        break;
1307                case SIOCADDPRL:
1308                case SIOCCHGPRL:
1309                        err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1310                        break;
1311                }
1312                dst_cache_reset(&t->dst_cache);
1313                netdev_state_change(dev);
1314                break;
1315
1316#ifdef CONFIG_IPV6_SIT_6RD
1317        case SIOCADD6RD:
1318        case SIOCCHG6RD:
1319        case SIOCDEL6RD:
1320                err = -EPERM;
1321                if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1322                        goto done;
1323
1324                err = -EFAULT;
1325                if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1326                                   sizeof(ip6rd)))
1327                        goto done;
1328
1329                if (cmd != SIOCDEL6RD) {
1330                        err = ipip6_tunnel_update_6rd(t, &ip6rd);
1331                        if (err < 0)
1332                                goto done;
1333                } else
1334                        ipip6_tunnel_clone_6rd(dev, sitn);
1335
1336                err = 0;
1337                break;
1338#endif
1339
1340        default:
1341                err = -EINVAL;
1342        }
1343
1344done:
1345        return err;
1346}
1347
1348static const struct net_device_ops ipip6_netdev_ops = {
1349        .ndo_init       = ipip6_tunnel_init,
1350        .ndo_uninit     = ipip6_tunnel_uninit,
1351        .ndo_start_xmit = sit_tunnel_xmit,
1352        .ndo_do_ioctl   = ipip6_tunnel_ioctl,
1353        .ndo_get_stats64 = ip_tunnel_get_stats64,
1354        .ndo_get_iflink = ip_tunnel_get_iflink,
1355};
1356
1357static void ipip6_dev_free(struct net_device *dev)
1358{
1359        struct ip_tunnel *tunnel = netdev_priv(dev);
1360
1361        dst_cache_destroy(&tunnel->dst_cache);
1362        free_percpu(dev->tstats);
1363}
1364
1365#define SIT_FEATURES (NETIF_F_SG           | \
1366                      NETIF_F_FRAGLIST     | \
1367                      NETIF_F_HIGHDMA      | \
1368                      NETIF_F_GSO_SOFTWARE | \
1369                      NETIF_F_HW_CSUM)
1370
1371static void ipip6_tunnel_setup(struct net_device *dev)
1372{
1373        struct ip_tunnel *tunnel = netdev_priv(dev);
1374        int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1375
1376        dev->netdev_ops         = &ipip6_netdev_ops;
1377        dev->needs_free_netdev  = true;
1378        dev->priv_destructor    = ipip6_dev_free;
1379
1380        dev->type               = ARPHRD_SIT;
1381        dev->hard_header_len    = LL_MAX_HEADER + t_hlen;
1382        dev->mtu                = ETH_DATA_LEN - t_hlen;
1383        dev->min_mtu            = IPV6_MIN_MTU;
1384        dev->max_mtu            = IP6_MAX_MTU - t_hlen;
1385        dev->flags              = IFF_NOARP;
1386        netif_keep_dst(dev);
1387        dev->addr_len           = 4;
1388        dev->features           |= NETIF_F_LLTX;
1389        dev->features           |= SIT_FEATURES;
1390        dev->hw_features        |= SIT_FEATURES;
1391}
1392
1393static int ipip6_tunnel_init(struct net_device *dev)
1394{
1395        struct ip_tunnel *tunnel = netdev_priv(dev);
1396        int err;
1397
1398        tunnel->dev = dev;
1399        tunnel->net = dev_net(dev);
1400        strcpy(tunnel->parms.name, dev->name);
1401
1402        ipip6_tunnel_bind_dev(dev);
1403        dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1404        if (!dev->tstats)
1405                return -ENOMEM;
1406
1407        err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1408        if (err) {
1409                free_percpu(dev->tstats);
1410                dev->tstats = NULL;
1411                return err;
1412        }
1413
1414        return 0;
1415}
1416
1417static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1418{
1419        struct ip_tunnel *tunnel = netdev_priv(dev);
1420        struct iphdr *iph = &tunnel->parms.iph;
1421        struct net *net = dev_net(dev);
1422        struct sit_net *sitn = net_generic(net, sit_net_id);
1423
1424        iph->version            = 4;
1425        iph->protocol           = IPPROTO_IPV6;
1426        iph->ihl                = 5;
1427        iph->ttl                = 64;
1428
1429        dev_hold(dev);
1430        rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1431}
1432
1433static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[],
1434                          struct netlink_ext_ack *extack)
1435{
1436        u8 proto;
1437
1438        if (!data || !data[IFLA_IPTUN_PROTO])
1439                return 0;
1440
1441        proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1442        if (!ipip6_valid_ip_proto(proto))
1443                return -EINVAL;
1444
1445        return 0;
1446}
1447
1448static void ipip6_netlink_parms(struct nlattr *data[],
1449                                struct ip_tunnel_parm *parms,
1450                                __u32 *fwmark)
1451{
1452        memset(parms, 0, sizeof(*parms));
1453
1454        parms->iph.version = 4;
1455        parms->iph.protocol = IPPROTO_IPV6;
1456        parms->iph.ihl = 5;
1457        parms->iph.ttl = 64;
1458
1459        if (!data)
1460                return;
1461
1462        if (data[IFLA_IPTUN_LINK])
1463                parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1464
1465        if (data[IFLA_IPTUN_LOCAL])
1466                parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1467
1468        if (data[IFLA_IPTUN_REMOTE])
1469                parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1470
1471        if (data[IFLA_IPTUN_TTL]) {
1472                parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1473                if (parms->iph.ttl)
1474                        parms->iph.frag_off = htons(IP_DF);
1475        }
1476
1477        if (data[IFLA_IPTUN_TOS])
1478                parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1479
1480        if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1481                parms->iph.frag_off = htons(IP_DF);
1482
1483        if (data[IFLA_IPTUN_FLAGS])
1484                parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1485
1486        if (data[IFLA_IPTUN_PROTO])
1487                parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1488
1489        if (data[IFLA_IPTUN_FWMARK])
1490                *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1491}
1492
1493/* This function returns true when ENCAP attributes are present in the nl msg */
1494static bool ipip6_netlink_encap_parms(struct nlattr *data[],
1495                                      struct ip_tunnel_encap *ipencap)
1496{
1497        bool ret = false;
1498
1499        memset(ipencap, 0, sizeof(*ipencap));
1500
1501        if (!data)
1502                return ret;
1503
1504        if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1505                ret = true;
1506                ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1507        }
1508
1509        if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1510                ret = true;
1511                ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1512        }
1513
1514        if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1515                ret = true;
1516                ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1517        }
1518
1519        if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1520                ret = true;
1521                ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1522        }
1523
1524        return ret;
1525}
1526
1527#ifdef CONFIG_IPV6_SIT_6RD
1528/* This function returns true when 6RD attributes are present in the nl msg */
1529static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1530                                    struct ip_tunnel_6rd *ip6rd)
1531{
1532        bool ret = false;
1533        memset(ip6rd, 0, sizeof(*ip6rd));
1534
1535        if (!data)
1536                return ret;
1537
1538        if (data[IFLA_IPTUN_6RD_PREFIX]) {
1539                ret = true;
1540                ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1541        }
1542
1543        if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1544                ret = true;
1545                ip6rd->relay_prefix =
1546                        nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1547        }
1548
1549        if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1550                ret = true;
1551                ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1552        }
1553
1554        if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1555                ret = true;
1556                ip6rd->relay_prefixlen =
1557                        nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1558        }
1559
1560        return ret;
1561}
1562#endif
1563
1564static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1565                         struct nlattr *tb[], struct nlattr *data[],
1566                         struct netlink_ext_ack *extack)
1567{
1568        struct net *net = dev_net(dev);
1569        struct ip_tunnel *nt;
1570        struct ip_tunnel_encap ipencap;
1571#ifdef CONFIG_IPV6_SIT_6RD
1572        struct ip_tunnel_6rd ip6rd;
1573#endif
1574        int err;
1575
1576        nt = netdev_priv(dev);
1577
1578        if (ipip6_netlink_encap_parms(data, &ipencap)) {
1579                err = ip_tunnel_encap_setup(nt, &ipencap);
1580                if (err < 0)
1581                        return err;
1582        }
1583
1584        ipip6_netlink_parms(data, &nt->parms, &nt->fwmark);
1585
1586        if (ipip6_tunnel_locate(net, &nt->parms, 0))
1587                return -EEXIST;
1588
1589        err = ipip6_tunnel_create(dev);
1590        if (err < 0)
1591                return err;
1592
1593        if (tb[IFLA_MTU]) {
1594                u32 mtu = nla_get_u32(tb[IFLA_MTU]);
1595
1596                if (mtu >= IPV6_MIN_MTU &&
1597                    mtu <= IP6_MAX_MTU - dev->hard_header_len)
1598                        dev->mtu = mtu;
1599        }
1600
1601#ifdef CONFIG_IPV6_SIT_6RD
1602        if (ipip6_netlink_6rd_parms(data, &ip6rd))
1603                err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1604#endif
1605
1606        return err;
1607}
1608
1609static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1610                            struct nlattr *data[],
1611                            struct netlink_ext_ack *extack)
1612{
1613        struct ip_tunnel *t = netdev_priv(dev);
1614        struct ip_tunnel_parm p;
1615        struct ip_tunnel_encap ipencap;
1616        struct net *net = t->net;
1617        struct sit_net *sitn = net_generic(net, sit_net_id);
1618#ifdef CONFIG_IPV6_SIT_6RD
1619        struct ip_tunnel_6rd ip6rd;
1620#endif
1621        __u32 fwmark = t->fwmark;
1622        int err;
1623
1624        if (dev == sitn->fb_tunnel_dev)
1625                return -EINVAL;
1626
1627        if (ipip6_netlink_encap_parms(data, &ipencap)) {
1628                err = ip_tunnel_encap_setup(t, &ipencap);
1629                if (err < 0)
1630                        return err;
1631        }
1632
1633        ipip6_netlink_parms(data, &p, &fwmark);
1634
1635        if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1636            (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1637                return -EINVAL;
1638
1639        t = ipip6_tunnel_locate(net, &p, 0);
1640
1641        if (t) {
1642                if (t->dev != dev)
1643                        return -EEXIST;
1644        } else
1645                t = netdev_priv(dev);
1646
1647        ipip6_tunnel_update(t, &p, fwmark);
1648
1649#ifdef CONFIG_IPV6_SIT_6RD
1650        if (ipip6_netlink_6rd_parms(data, &ip6rd))
1651                return ipip6_tunnel_update_6rd(t, &ip6rd);
1652#endif
1653
1654        return 0;
1655}
1656
1657static size_t ipip6_get_size(const struct net_device *dev)
1658{
1659        return
1660                /* IFLA_IPTUN_LINK */
1661                nla_total_size(4) +
1662                /* IFLA_IPTUN_LOCAL */
1663                nla_total_size(4) +
1664                /* IFLA_IPTUN_REMOTE */
1665                nla_total_size(4) +
1666                /* IFLA_IPTUN_TTL */
1667                nla_total_size(1) +
1668                /* IFLA_IPTUN_TOS */
1669                nla_total_size(1) +
1670                /* IFLA_IPTUN_PMTUDISC */
1671                nla_total_size(1) +
1672                /* IFLA_IPTUN_FLAGS */
1673                nla_total_size(2) +
1674                /* IFLA_IPTUN_PROTO */
1675                nla_total_size(1) +
1676#ifdef CONFIG_IPV6_SIT_6RD
1677                /* IFLA_IPTUN_6RD_PREFIX */
1678                nla_total_size(sizeof(struct in6_addr)) +
1679                /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1680                nla_total_size(4) +
1681                /* IFLA_IPTUN_6RD_PREFIXLEN */
1682                nla_total_size(2) +
1683                /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1684                nla_total_size(2) +
1685#endif
1686                /* IFLA_IPTUN_ENCAP_TYPE */
1687                nla_total_size(2) +
1688                /* IFLA_IPTUN_ENCAP_FLAGS */
1689                nla_total_size(2) +
1690                /* IFLA_IPTUN_ENCAP_SPORT */
1691                nla_total_size(2) +
1692                /* IFLA_IPTUN_ENCAP_DPORT */
1693                nla_total_size(2) +
1694                /* IFLA_IPTUN_FWMARK */
1695                nla_total_size(4) +
1696                0;
1697}
1698
1699static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1700{
1701        struct ip_tunnel *tunnel = netdev_priv(dev);
1702        struct ip_tunnel_parm *parm = &tunnel->parms;
1703
1704        if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1705            nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1706            nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1707            nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1708            nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1709            nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1710                       !!(parm->iph.frag_off & htons(IP_DF))) ||
1711            nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1712            nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) ||
1713            nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
1714                goto nla_put_failure;
1715
1716#ifdef CONFIG_IPV6_SIT_6RD
1717        if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1718                             &tunnel->ip6rd.prefix) ||
1719            nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1720                            tunnel->ip6rd.relay_prefix) ||
1721            nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1722                        tunnel->ip6rd.prefixlen) ||
1723            nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1724                        tunnel->ip6rd.relay_prefixlen))
1725                goto nla_put_failure;
1726#endif
1727
1728        if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1729                        tunnel->encap.type) ||
1730            nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1731                        tunnel->encap.sport) ||
1732            nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1733                        tunnel->encap.dport) ||
1734            nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1735                        tunnel->encap.flags))
1736                goto nla_put_failure;
1737
1738        return 0;
1739
1740nla_put_failure:
1741        return -EMSGSIZE;
1742}
1743
1744static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1745        [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
1746        [IFLA_IPTUN_LOCAL]              = { .type = NLA_U32 },
1747        [IFLA_IPTUN_REMOTE]             = { .type = NLA_U32 },
1748        [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
1749        [IFLA_IPTUN_TOS]                = { .type = NLA_U8 },
1750        [IFLA_IPTUN_PMTUDISC]           = { .type = NLA_U8 },
1751        [IFLA_IPTUN_FLAGS]              = { .type = NLA_U16 },
1752        [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
1753#ifdef CONFIG_IPV6_SIT_6RD
1754        [IFLA_IPTUN_6RD_PREFIX]         = { .len = sizeof(struct in6_addr) },
1755        [IFLA_IPTUN_6RD_RELAY_PREFIX]   = { .type = NLA_U32 },
1756        [IFLA_IPTUN_6RD_PREFIXLEN]      = { .type = NLA_U16 },
1757        [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1758#endif
1759        [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
1760        [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
1761        [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
1762        [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
1763        [IFLA_IPTUN_FWMARK]             = { .type = NLA_U32 },
1764};
1765
1766static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1767{
1768        struct net *net = dev_net(dev);
1769        struct sit_net *sitn = net_generic(net, sit_net_id);
1770
1771        if (dev != sitn->fb_tunnel_dev)
1772                unregister_netdevice_queue(dev, head);
1773}
1774
1775static struct rtnl_link_ops sit_link_ops __read_mostly = {
1776        .kind           = "sit",
1777        .maxtype        = IFLA_IPTUN_MAX,
1778        .policy         = ipip6_policy,
1779        .priv_size      = sizeof(struct ip_tunnel),
1780        .setup          = ipip6_tunnel_setup,
1781        .validate       = ipip6_validate,
1782        .newlink        = ipip6_newlink,
1783        .changelink     = ipip6_changelink,
1784        .get_size       = ipip6_get_size,
1785        .fill_info      = ipip6_fill_info,
1786        .dellink        = ipip6_dellink,
1787        .get_link_net   = ip_tunnel_get_link_net,
1788};
1789
1790static struct xfrm_tunnel sit_handler __read_mostly = {
1791        .handler        =       ipip6_rcv,
1792        .err_handler    =       ipip6_err,
1793        .priority       =       1,
1794};
1795
1796static struct xfrm_tunnel ipip_handler __read_mostly = {
1797        .handler        =       ipip_rcv,
1798        .err_handler    =       ipip6_err,
1799        .priority       =       2,
1800};
1801
1802#if IS_ENABLED(CONFIG_MPLS)
1803static struct xfrm_tunnel mplsip_handler __read_mostly = {
1804        .handler        =       mplsip_rcv,
1805        .err_handler    =       ipip6_err,
1806        .priority       =       2,
1807};
1808#endif
1809
1810static void __net_exit sit_destroy_tunnels(struct net *net,
1811                                           struct list_head *head)
1812{
1813        struct sit_net *sitn = net_generic(net, sit_net_id);
1814        struct net_device *dev, *aux;
1815        int prio;
1816
1817        for_each_netdev_safe(net, dev, aux)
1818                if (dev->rtnl_link_ops == &sit_link_ops)
1819                        unregister_netdevice_queue(dev, head);
1820
1821        for (prio = 1; prio < 4; prio++) {
1822                int h;
1823                for (h = 0; h < IP6_SIT_HASH_SIZE; h++) {
1824                        struct ip_tunnel *t;
1825
1826                        t = rtnl_dereference(sitn->tunnels[prio][h]);
1827                        while (t) {
1828                                /* If dev is in the same netns, it has already
1829                                 * been added to the list by the previous loop.
1830                                 */
1831                                if (!net_eq(dev_net(t->dev), net))
1832                                        unregister_netdevice_queue(t->dev,
1833                                                                   head);
1834                                t = rtnl_dereference(t->next);
1835                        }
1836                }
1837        }
1838}
1839
1840static int __net_init sit_init_net(struct net *net)
1841{
1842        struct sit_net *sitn = net_generic(net, sit_net_id);
1843        struct ip_tunnel *t;
1844        int err;
1845
1846        sitn->tunnels[0] = sitn->tunnels_wc;
1847        sitn->tunnels[1] = sitn->tunnels_l;
1848        sitn->tunnels[2] = sitn->tunnels_r;
1849        sitn->tunnels[3] = sitn->tunnels_r_l;
1850
1851        if (!net_has_fallback_tunnels(net))
1852                return 0;
1853
1854        sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1855                                           NET_NAME_UNKNOWN,
1856                                           ipip6_tunnel_setup);
1857        if (!sitn->fb_tunnel_dev) {
1858                err = -ENOMEM;
1859                goto err_alloc_dev;
1860        }
1861        dev_net_set(sitn->fb_tunnel_dev, net);
1862        sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1863        /* FB netdevice is special: we have one, and only one per netns.
1864         * Allowing to move it to another netns is clearly unsafe.
1865         */
1866        sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1867
1868        err = register_netdev(sitn->fb_tunnel_dev);
1869        if (err)
1870                goto err_reg_dev;
1871
1872        ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1873        ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1874
1875        t = netdev_priv(sitn->fb_tunnel_dev);
1876
1877        strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1878        return 0;
1879
1880err_reg_dev:
1881        ipip6_dev_free(sitn->fb_tunnel_dev);
1882        free_netdev(sitn->fb_tunnel_dev);
1883err_alloc_dev:
1884        return err;
1885}
1886
1887static void __net_exit sit_exit_batch_net(struct list_head *net_list)
1888{
1889        LIST_HEAD(list);
1890        struct net *net;
1891
1892        rtnl_lock();
1893        list_for_each_entry(net, net_list, exit_list)
1894                sit_destroy_tunnels(net, &list);
1895
1896        unregister_netdevice_many(&list);
1897        rtnl_unlock();
1898}
1899
1900static struct pernet_operations sit_net_ops = {
1901        .init = sit_init_net,
1902        .exit_batch = sit_exit_batch_net,
1903        .id   = &sit_net_id,
1904        .size = sizeof(struct sit_net),
1905};
1906
1907static void __exit sit_cleanup(void)
1908{
1909        rtnl_link_unregister(&sit_link_ops);
1910        xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1911        xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1912#if IS_ENABLED(CONFIG_MPLS)
1913        xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1914#endif
1915
1916        unregister_pernet_device(&sit_net_ops);
1917        rcu_barrier(); /* Wait for completion of call_rcu()'s */
1918}
1919
1920static int __init sit_init(void)
1921{
1922        int err;
1923
1924        pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
1925
1926        err = register_pernet_device(&sit_net_ops);
1927        if (err < 0)
1928                return err;
1929        err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1930        if (err < 0) {
1931                pr_info("%s: can't register ip6ip4\n", __func__);
1932                goto xfrm_tunnel_failed;
1933        }
1934        err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1935        if (err < 0) {
1936                pr_info("%s: can't register ip4ip4\n", __func__);
1937                goto xfrm_tunnel4_failed;
1938        }
1939#if IS_ENABLED(CONFIG_MPLS)
1940        err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
1941        if (err < 0) {
1942                pr_info("%s: can't register mplsip\n", __func__);
1943                goto xfrm_tunnel_mpls_failed;
1944        }
1945#endif
1946        err = rtnl_link_register(&sit_link_ops);
1947        if (err < 0)
1948                goto rtnl_link_failed;
1949
1950out:
1951        return err;
1952
1953rtnl_link_failed:
1954#if IS_ENABLED(CONFIG_MPLS)
1955        xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1956xfrm_tunnel_mpls_failed:
1957#endif
1958        xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1959xfrm_tunnel4_failed:
1960        xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1961xfrm_tunnel_failed:
1962        unregister_pernet_device(&sit_net_ops);
1963        goto out;
1964}
1965
1966module_init(sit_init);
1967module_exit(sit_cleanup);
1968MODULE_LICENSE("GPL");
1969MODULE_ALIAS_RTNL_LINK("sit");
1970MODULE_ALIAS_NETDEV("sit0");
1971