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/mroute.h>
  28#include <linux/init.h>
  29#include <linux/in6.h>
  30#include <linux/inetdevice.h>
  31#include <linux/igmp.h>
  32#include <linux/netfilter_ipv4.h>
  33#include <linux/etherdevice.h>
  34#include <linux/if_ether.h>
  35#include <linux/hash.h>
  36#include <linux/if_tunnel.h>
  37#include <linux/ip6_tunnel.h>
  38
  39#include <net/sock.h>
  40#include <net/ip.h>
  41#include <net/ip_tunnels.h>
  42#include <net/icmp.h>
  43#include <net/protocol.h>
  44#include <net/addrconf.h>
  45#include <net/arp.h>
  46#include <net/checksum.h>
  47#include <net/dsfield.h>
  48#include <net/inet_ecn.h>
  49#include <net/xfrm.h>
  50#include <net/net_namespace.h>
  51#include <net/netns/generic.h>
  52#include <net/rtnetlink.h>
  53
  54#include <net/ipv6.h>
  55#include <net/ip6_fib.h>
  56#include <net/ip6_route.h>
  57#include <net/ip6_tunnel.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 IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
  65#define IPV6_TCLASS_SHIFT 20
  66
  67#define HASH_SIZE_SHIFT  5
  68#define HASH_SIZE (1 << HASH_SIZE_SHIFT)
  69
  70static int ip6gre_net_id __read_mostly;
  71struct ip6gre_net {
  72        struct ip6_tnl __rcu *tunnels[4][HASH_SIZE];
  73
  74        struct net_device *fb_tunnel_dev;
  75};
  76
  77static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
  78static int ip6gre_tunnel_init(struct net_device *dev);
  79static void ip6gre_tunnel_setup(struct net_device *dev);
  80static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
  81static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
  82
  83/* Tunnel hash table */
  84
  85/*
  86   4 hash tables:
  87
  88   3: (remote,local)
  89   2: (remote,*)
  90   1: (*,local)
  91   0: (*,*)
  92
  93   We require exact key match i.e. if a key is present in packet
  94   it will match only tunnel with the same key; if it is not present,
  95   it will match only keyless tunnel.
  96
  97   All keysless packets, if not matched configured keyless tunnels
  98   will match fallback tunnel.
  99 */
 100
 101#define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(HASH_SIZE - 1))
 102static u32 HASH_ADDR(const struct in6_addr *addr)
 103{
 104        u32 hash = ipv6_addr_hash(addr);
 105
 106        return hash_32(hash, HASH_SIZE_SHIFT);
 107}
 108
 109#define tunnels_r_l     tunnels[3]
 110#define tunnels_r       tunnels[2]
 111#define tunnels_l       tunnels[1]
 112#define tunnels_wc      tunnels[0]
 113
 114/* Given src, dst and key, find appropriate for input tunnel. */
 115
 116static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 117                const struct in6_addr *remote, const struct in6_addr *local,
 118                __be32 key, __be16 gre_proto)
 119{
 120        struct net *net = dev_net(dev);
 121        int link = dev->ifindex;
 122        unsigned int h0 = HASH_ADDR(remote);
 123        unsigned int h1 = HASH_KEY(key);
 124        struct ip6_tnl *t, *cand = NULL;
 125        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 126        int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
 127                       ARPHRD_ETHER : ARPHRD_IP6GRE;
 128        int score, cand_score = 4;
 129
 130        for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
 131                if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 132                    !ipv6_addr_equal(remote, &t->parms.raddr) ||
 133                    key != t->parms.i_key ||
 134                    !(t->dev->flags & IFF_UP))
 135                        continue;
 136
 137                if (t->dev->type != ARPHRD_IP6GRE &&
 138                    t->dev->type != dev_type)
 139                        continue;
 140
 141                score = 0;
 142                if (t->parms.link != link)
 143                        score |= 1;
 144                if (t->dev->type != dev_type)
 145                        score |= 2;
 146                if (score == 0)
 147                        return t;
 148
 149                if (score < cand_score) {
 150                        cand = t;
 151                        cand_score = score;
 152                }
 153        }
 154
 155        for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
 156                if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
 157                    key != t->parms.i_key ||
 158                    !(t->dev->flags & IFF_UP))
 159                        continue;
 160
 161                if (t->dev->type != ARPHRD_IP6GRE &&
 162                    t->dev->type != dev_type)
 163                        continue;
 164
 165                score = 0;
 166                if (t->parms.link != link)
 167                        score |= 1;
 168                if (t->dev->type != dev_type)
 169                        score |= 2;
 170                if (score == 0)
 171                        return t;
 172
 173                if (score < cand_score) {
 174                        cand = t;
 175                        cand_score = score;
 176                }
 177        }
 178
 179        for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
 180                if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
 181                          (!ipv6_addr_equal(local, &t->parms.raddr) ||
 182                                 !ipv6_addr_is_multicast(local))) ||
 183                    key != t->parms.i_key ||
 184                    !(t->dev->flags & IFF_UP))
 185                        continue;
 186
 187                if (t->dev->type != ARPHRD_IP6GRE &&
 188                    t->dev->type != dev_type)
 189                        continue;
 190
 191                score = 0;
 192                if (t->parms.link != link)
 193                        score |= 1;
 194                if (t->dev->type != dev_type)
 195                        score |= 2;
 196                if (score == 0)
 197                        return t;
 198
 199                if (score < cand_score) {
 200                        cand = t;
 201                        cand_score = score;
 202                }
 203        }
 204
 205        for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
 206                if (t->parms.i_key != key ||
 207                    !(t->dev->flags & IFF_UP))
 208                        continue;
 209
 210                if (t->dev->type != ARPHRD_IP6GRE &&
 211                    t->dev->type != dev_type)
 212                        continue;
 213
 214                score = 0;
 215                if (t->parms.link != link)
 216                        score |= 1;
 217                if (t->dev->type != dev_type)
 218                        score |= 2;
 219                if (score == 0)
 220                        return t;
 221
 222                if (score < cand_score) {
 223                        cand = t;
 224                        cand_score = score;
 225                }
 226        }
 227
 228        if (cand != NULL)
 229                return cand;
 230
 231        dev = ign->fb_tunnel_dev;
 232        if (dev->flags & IFF_UP)
 233                return netdev_priv(dev);
 234
 235        return NULL;
 236}
 237
 238static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
 239                const struct __ip6_tnl_parm *p)
 240{
 241        const struct in6_addr *remote = &p->raddr;
 242        const struct in6_addr *local = &p->laddr;
 243        unsigned int h = HASH_KEY(p->i_key);
 244        int prio = 0;
 245
 246        if (!ipv6_addr_any(local))
 247                prio |= 1;
 248        if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
 249                prio |= 2;
 250                h ^= HASH_ADDR(remote);
 251        }
 252
 253        return &ign->tunnels[prio][h];
 254}
 255
 256static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
 257                const struct ip6_tnl *t)
 258{
 259        return __ip6gre_bucket(ign, &t->parms);
 260}
 261
 262static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
 263{
 264        struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
 265
 266        rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 267        rcu_assign_pointer(*tp, t);
 268}
 269
 270static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
 271{
 272        struct ip6_tnl __rcu **tp;
 273        struct ip6_tnl *iter;
 274
 275        for (tp = ip6gre_bucket(ign, t);
 276             (iter = rtnl_dereference(*tp)) != NULL;
 277             tp = &iter->next) {
 278                if (t == iter) {
 279                        rcu_assign_pointer(*tp, t->next);
 280                        break;
 281                }
 282        }
 283}
 284
 285static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
 286                                           const struct __ip6_tnl_parm *parms,
 287                                           int type)
 288{
 289        const struct in6_addr *remote = &parms->raddr;
 290        const struct in6_addr *local = &parms->laddr;
 291        __be32 key = parms->i_key;
 292        int link = parms->link;
 293        struct ip6_tnl *t;
 294        struct ip6_tnl __rcu **tp;
 295        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 296
 297        for (tp = __ip6gre_bucket(ign, parms);
 298             (t = rtnl_dereference(*tp)) != NULL;
 299             tp = &t->next)
 300                if (ipv6_addr_equal(local, &t->parms.laddr) &&
 301                    ipv6_addr_equal(remote, &t->parms.raddr) &&
 302                    key == t->parms.i_key &&
 303                    link == t->parms.link &&
 304                    type == t->dev->type)
 305                        break;
 306
 307        return t;
 308}
 309
 310static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
 311                const struct __ip6_tnl_parm *parms, int create)
 312{
 313        struct ip6_tnl *t, *nt;
 314        struct net_device *dev;
 315        char name[IFNAMSIZ];
 316        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 317
 318        t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
 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, ip6gre_tunnel_setup);
 328        if (!dev)
 329                return NULL;
 330
 331        dev_net_set(dev, net);
 332
 333        nt = netdev_priv(dev);
 334        nt->parms = *parms;
 335        dev->rtnl_link_ops = &ip6gre_link_ops;
 336
 337        nt->dev = dev;
 338        nt->net = dev_net(dev);
 339        ip6gre_tnl_link_config(nt, 1);
 340
 341        if (register_netdevice(dev) < 0)
 342                goto failed_free;
 343
 344        /* Can use a lockless transmit, unless we generate output sequences */
 345        if (!(nt->parms.o_flags & GRE_SEQ))
 346                dev->features |= NETIF_F_LLTX;
 347
 348        dev_hold(dev);
 349        ip6gre_tunnel_link(ign, nt);
 350        return nt;
 351
 352failed_free:
 353        free_netdev(dev);
 354        return NULL;
 355}
 356
 357static void ip6gre_tunnel_uninit(struct net_device *dev)
 358{
 359        struct net *net = dev_net(dev);
 360        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 361
 362        ip6gre_tunnel_unlink(ign, netdev_priv(dev));
 363        dev_put(dev);
 364}
 365
 366
 367static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 368                u8 type, u8 code, int offset, __be32 info)
 369{
 370        const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 371        __be16 *p = (__be16 *)(skb->data + offset);
 372        int grehlen = offset + 4;
 373        struct ip6_tnl *t;
 374        __be16 flags;
 375
 376        flags = p[0];
 377        if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
 378                if (flags&(GRE_VERSION|GRE_ROUTING))
 379                        return;
 380                if (flags&GRE_KEY) {
 381                        grehlen += 4;
 382                        if (flags&GRE_CSUM)
 383                                grehlen += 4;
 384                }
 385        }
 386
 387        /* If only 8 bytes returned, keyed message will be dropped here */
 388        if (!pskb_may_pull(skb, grehlen))
 389                return;
 390        ipv6h = (const struct ipv6hdr *)skb->data;
 391        p = (__be16 *)(skb->data + offset);
 392
 393        t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
 394                                flags & GRE_KEY ?
 395                                *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
 396                                p[1]);
 397        if (t == NULL)
 398                return;
 399
 400        switch (type) {
 401                __u32 teli;
 402                struct ipv6_tlv_tnl_enc_lim *tel;
 403                __u32 mtu;
 404        case ICMPV6_DEST_UNREACH:
 405                net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
 406                                     t->parms.name);
 407                break;
 408        case ICMPV6_TIME_EXCEED:
 409                if (code == ICMPV6_EXC_HOPLIMIT) {
 410                        net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 411                                             t->parms.name);
 412                }
 413                break;
 414        case ICMPV6_PARAMPROB:
 415                teli = 0;
 416                if (code == ICMPV6_HDR_FIELD)
 417                        teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 418
 419                if (teli && teli == info - 2) {
 420                        tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 421                        if (tel->encap_limit == 0) {
 422                                net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 423                                                     t->parms.name);
 424                        }
 425                } else {
 426                        net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 427                                             t->parms.name);
 428                }
 429                break;
 430        case ICMPV6_PKT_TOOBIG:
 431                mtu = info - offset;
 432                if (mtu < IPV6_MIN_MTU)
 433                        mtu = IPV6_MIN_MTU;
 434                t->dev->mtu = mtu;
 435                break;
 436        }
 437
 438        if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
 439                t->err_count++;
 440        else
 441                t->err_count = 1;
 442        t->err_time = jiffies;
 443}
 444
 445static int ip6gre_rcv(struct sk_buff *skb)
 446{
 447        const struct ipv6hdr *ipv6h;
 448        u8     *h;
 449        __be16    flags;
 450        __sum16   csum = 0;
 451        __be32 key = 0;
 452        u32    seqno = 0;
 453        struct ip6_tnl *tunnel;
 454        int    offset = 4;
 455        __be16 gre_proto;
 456        int err;
 457
 458        if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
 459                goto drop;
 460
 461        ipv6h = ipv6_hdr(skb);
 462        h = skb->data;
 463        flags = *(__be16 *)h;
 464
 465        if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
 466                /* - Version must be 0.
 467                   - We do not support routing headers.
 468                 */
 469                if (flags&(GRE_VERSION|GRE_ROUTING))
 470                        goto drop;
 471
 472                if (flags&GRE_CSUM) {
 473                        switch (skb->ip_summed) {
 474                        case CHECKSUM_COMPLETE:
 475                                csum = csum_fold(skb->csum);
 476                                if (!csum)
 477                                        break;
 478                                /* fall through */
 479                        case CHECKSUM_NONE:
 480                                skb->csum = 0;
 481                                csum = __skb_checksum_complete(skb);
 482                                skb->ip_summed = CHECKSUM_COMPLETE;
 483                        }
 484                        offset += 4;
 485                }
 486                if (flags&GRE_KEY) {
 487                        key = *(__be32 *)(h + offset);
 488                        offset += 4;
 489                }
 490                if (flags&GRE_SEQ) {
 491                        seqno = ntohl(*(__be32 *)(h + offset));
 492                        offset += 4;
 493                }
 494        }
 495
 496        gre_proto = *(__be16 *)(h + 2);
 497
 498        tunnel = ip6gre_tunnel_lookup(skb->dev,
 499                                          &ipv6h->saddr, &ipv6h->daddr, key,
 500                                          gre_proto);
 501        if (tunnel) {
 502                struct pcpu_tstats *tstats;
 503
 504                if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 505                        goto drop;
 506
 507                if (!ip6_tnl_rcv_ctl(tunnel, &ipv6h->daddr, &ipv6h->saddr)) {
 508                        tunnel->dev->stats.rx_dropped++;
 509                        goto drop;
 510                }
 511
 512                skb->protocol = gre_proto;
 513                /* WCCP version 1 and 2 protocol decoding.
 514                 * - Change protocol to IP
 515                 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
 516                 */
 517                if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
 518                        skb->protocol = htons(ETH_P_IP);
 519                        if ((*(h + offset) & 0xF0) != 0x40)
 520                                offset += 4;
 521                }
 522
 523                skb->mac_header = skb->network_header;
 524                __pskb_pull(skb, offset);
 525                skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
 526
 527                if (((flags&GRE_CSUM) && csum) ||
 528                    (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
 529                        tunnel->dev->stats.rx_crc_errors++;
 530                        tunnel->dev->stats.rx_errors++;
 531                        goto drop;
 532                }
 533                if (tunnel->parms.i_flags&GRE_SEQ) {
 534                        if (!(flags&GRE_SEQ) ||
 535                            (tunnel->i_seqno &&
 536                                        (s32)(seqno - tunnel->i_seqno) < 0)) {
 537                                tunnel->dev->stats.rx_fifo_errors++;
 538                                tunnel->dev->stats.rx_errors++;
 539                                goto drop;
 540                        }
 541                        tunnel->i_seqno = seqno + 1;
 542                }
 543
 544                /* Warning: All skb pointers will be invalidated! */
 545                if (tunnel->dev->type == ARPHRD_ETHER) {
 546                        if (!pskb_may_pull(skb, ETH_HLEN)) {
 547                                tunnel->dev->stats.rx_length_errors++;
 548                                tunnel->dev->stats.rx_errors++;
 549                                goto drop;
 550                        }
 551
 552                        ipv6h = ipv6_hdr(skb);
 553                        skb->protocol = eth_type_trans(skb, tunnel->dev);
 554                        skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 555                }
 556
 557                __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 558
 559                skb_reset_network_header(skb);
 560
 561                err = IP6_ECN_decapsulate(ipv6h, skb);
 562                if (unlikely(err)) {
 563                        if (log_ecn_error)
 564                                net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
 565                                                     &ipv6h->saddr,
 566                                                     ipv6_get_dsfield(ipv6h));
 567                        if (err > 1) {
 568                                ++tunnel->dev->stats.rx_frame_errors;
 569                                ++tunnel->dev->stats.rx_errors;
 570                                goto drop;
 571                        }
 572                }
 573
 574                tstats = this_cpu_ptr(tunnel->dev->tstats);
 575                u64_stats_update_begin(&tstats->syncp);
 576                tstats->rx_packets++;
 577                tstats->rx_bytes += skb->len;
 578                u64_stats_update_end(&tstats->syncp);
 579
 580                netif_rx(skb);
 581
 582                return 0;
 583        }
 584        icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 585
 586drop:
 587        kfree_skb(skb);
 588        return 0;
 589}
 590
 591struct ipv6_tel_txoption {
 592        struct ipv6_txoptions ops;
 593        __u8 dst_opt[8];
 594};
 595
 596static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 597{
 598        memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 599
 600        opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 601        opt->dst_opt[3] = 1;
 602        opt->dst_opt[4] = encap_limit;
 603        opt->dst_opt[5] = IPV6_TLV_PADN;
 604        opt->dst_opt[6] = 1;
 605
 606        opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 607        opt->ops.opt_nflen = 8;
 608}
 609
 610static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
 611                         struct net_device *dev,
 612                         __u8 dsfield,
 613                         struct flowi6 *fl6,
 614                         int encap_limit,
 615                         __u32 *pmtu)
 616{
 617        struct net *net = dev_net(dev);
 618        struct ip6_tnl *tunnel = netdev_priv(dev);
 619        struct net_device *tdev;    /* Device to other host */
 620        struct ipv6hdr  *ipv6h;     /* Our new IP header */
 621        unsigned int max_headroom = 0; /* The extra header space needed */
 622        int    gre_hlen;
 623        struct ipv6_tel_txoption opt;
 624        int    mtu;
 625        struct dst_entry *dst = NULL, *ndst = NULL;
 626        struct net_device_stats *stats = &tunnel->dev->stats;
 627        int err = -1;
 628        u8 proto;
 629        struct sk_buff *new_skb;
 630
 631        if (dev->type == ARPHRD_ETHER)
 632                IPCB(skb)->flags = 0;
 633
 634        if (dev->header_ops && dev->type == ARPHRD_IP6GRE) {
 635                gre_hlen = 0;
 636                ipv6h = (struct ipv6hdr *)skb->data;
 637                fl6->daddr = ipv6h->daddr;
 638        } else {
 639                gre_hlen = tunnel->hlen;
 640                fl6->daddr = tunnel->parms.raddr;
 641        }
 642
 643        if (!fl6->flowi6_mark)
 644                dst = ip6_tnl_dst_check(tunnel);
 645
 646        if (!dst) {
 647                ndst = ip6_route_output(net, NULL, fl6);
 648
 649                if (ndst->error)
 650                        goto tx_err_link_failure;
 651                ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
 652                if (IS_ERR(ndst)) {
 653                        err = PTR_ERR(ndst);
 654                        ndst = NULL;
 655                        goto tx_err_link_failure;
 656                }
 657                dst = ndst;
 658        }
 659
 660        tdev = dst->dev;
 661
 662        if (tdev == dev) {
 663                stats->collisions++;
 664                net_warn_ratelimited("%s: Local routing loop detected!\n",
 665                                     tunnel->parms.name);
 666                goto tx_err_dst_release;
 667        }
 668
 669        mtu = dst_mtu(dst) - sizeof(*ipv6h);
 670        if (encap_limit >= 0) {
 671                max_headroom += 8;
 672                mtu -= 8;
 673        }
 674        if (mtu < IPV6_MIN_MTU)
 675                mtu = IPV6_MIN_MTU;
 676        if (skb_dst(skb))
 677                skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 678        if (skb->len > mtu) {
 679                *pmtu = mtu;
 680                err = -EMSGSIZE;
 681                goto tx_err_dst_release;
 682        }
 683
 684        if (tunnel->err_count > 0) {
 685                if (time_before(jiffies,
 686                                tunnel->err_time + IP6TUNNEL_ERR_TIMEO)) {
 687                        tunnel->err_count--;
 688
 689                        dst_link_failure(skb);
 690                } else
 691                        tunnel->err_count = 0;
 692        }
 693
 694        skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
 695
 696        max_headroom += LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
 697
 698        if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 699            (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 700                new_skb = skb_realloc_headroom(skb, max_headroom);
 701                if (max_headroom > dev->needed_headroom)
 702                        dev->needed_headroom = max_headroom;
 703                if (!new_skb)
 704                        goto tx_err_dst_release;
 705
 706                if (skb->sk)
 707                        skb_set_owner_w(new_skb, skb->sk);
 708                consume_skb(skb);
 709                skb = new_skb;
 710        }
 711
 712        if (fl6->flowi6_mark) {
 713                skb_dst_set(skb, dst);
 714                ndst = NULL;
 715        } else {
 716                skb_dst_set_noref(skb, dst);
 717        }
 718
 719        proto = NEXTHDR_GRE;
 720        if (encap_limit >= 0) {
 721                init_tel_txopt(&opt, encap_limit);
 722                ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
 723        }
 724
 725        if (likely(!skb->encapsulation)) {
 726                skb_reset_inner_headers(skb);
 727                skb->encapsulation = 1;
 728        }
 729
 730        skb_push(skb, gre_hlen);
 731        skb_reset_network_header(skb);
 732        skb_set_transport_header(skb, sizeof(*ipv6h));
 733
 734        /*
 735         *      Push down and install the IP header.
 736         */
 737        ipv6h = ipv6_hdr(skb);
 738        ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), fl6->flowlabel);
 739        ipv6h->hop_limit = tunnel->parms.hop_limit;
 740        ipv6h->nexthdr = proto;
 741        ipv6h->saddr = fl6->saddr;
 742        ipv6h->daddr = fl6->daddr;
 743
 744        ((__be16 *)(ipv6h + 1))[0] = tunnel->parms.o_flags;
 745        ((__be16 *)(ipv6h + 1))[1] = (dev->type == ARPHRD_ETHER) ?
 746                                   htons(ETH_P_TEB) : skb->protocol;
 747
 748        if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
 749                __be32 *ptr = (__be32 *)(((u8 *)ipv6h) + tunnel->hlen - 4);
 750
 751                if (tunnel->parms.o_flags&GRE_SEQ) {
 752                        ++tunnel->o_seqno;
 753                        *ptr = htonl(tunnel->o_seqno);
 754                        ptr--;
 755                }
 756                if (tunnel->parms.o_flags&GRE_KEY) {
 757                        *ptr = tunnel->parms.o_key;
 758                        ptr--;
 759                }
 760                if (tunnel->parms.o_flags&GRE_CSUM) {
 761                        *ptr = 0;
 762                        *(__sum16 *)ptr = ip_compute_csum((void *)(ipv6h+1),
 763                                skb->len - sizeof(struct ipv6hdr));
 764                }
 765        }
 766
 767        ip6tunnel_xmit(skb, dev);
 768        if (ndst)
 769                ip6_tnl_dst_store(tunnel, ndst);
 770        return 0;
 771tx_err_link_failure:
 772        stats->tx_carrier_errors++;
 773        dst_link_failure(skb);
 774tx_err_dst_release:
 775        dst_release(ndst);
 776        return err;
 777}
 778
 779static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 780{
 781        struct ip6_tnl *t = netdev_priv(dev);
 782        const struct iphdr  *iph = ip_hdr(skb);
 783        int encap_limit = -1;
 784        struct flowi6 fl6;
 785        __u8 dsfield;
 786        __u32 mtu;
 787        int err;
 788
 789        if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 790                encap_limit = t->parms.encap_limit;
 791
 792        memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 793        fl6.flowi6_proto = IPPROTO_IPIP;
 794
 795        dsfield = ipv4_get_dsfield(iph);
 796
 797        if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 798                fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
 799                                          & IPV6_TCLASS_MASK;
 800        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 801                fl6.flowi6_mark = skb->mark;
 802
 803        err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 804        if (err != 0) {
 805                /* XXX: send ICMP error even if DF is not set. */
 806                if (err == -EMSGSIZE)
 807                        icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 808                                  htonl(mtu));
 809                return -1;
 810        }
 811
 812        return 0;
 813}
 814
 815static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 816{
 817        struct ip6_tnl *t = netdev_priv(dev);
 818        struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 819        int encap_limit = -1;
 820        __u16 offset;
 821        struct flowi6 fl6;
 822        __u8 dsfield;
 823        __u32 mtu;
 824        int err;
 825
 826        if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
 827                return -1;
 828
 829        offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 830        if (offset > 0) {
 831                struct ipv6_tlv_tnl_enc_lim *tel;
 832                tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 833                if (tel->encap_limit == 0) {
 834                        icmpv6_send(skb, ICMPV6_PARAMPROB,
 835                                    ICMPV6_HDR_FIELD, offset + 2);
 836                        return -1;
 837                }
 838                encap_limit = tel->encap_limit - 1;
 839        } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 840                encap_limit = t->parms.encap_limit;
 841
 842        memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 843        fl6.flowi6_proto = IPPROTO_IPV6;
 844
 845        dsfield = ipv6_get_dsfield(ipv6h);
 846        if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 847                fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
 848        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 849                fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);
 850        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 851                fl6.flowi6_mark = skb->mark;
 852
 853        err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 854        if (err != 0) {
 855                if (err == -EMSGSIZE)
 856                        icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 857                return -1;
 858        }
 859
 860        return 0;
 861}
 862
 863/**
 864 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 865 *   @t: the outgoing tunnel device
 866 *   @hdr: IPv6 header from the incoming packet
 867 *
 868 * Description:
 869 *   Avoid trivial tunneling loop by checking that tunnel exit-point
 870 *   doesn't match source of incoming packet.
 871 *
 872 * Return:
 873 *   1 if conflict,
 874 *   0 else
 875 **/
 876
 877static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
 878        const struct ipv6hdr *hdr)
 879{
 880        return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 881}
 882
 883static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 884{
 885        struct ip6_tnl *t = netdev_priv(dev);
 886        int encap_limit = -1;
 887        struct flowi6 fl6;
 888        __u32 mtu;
 889        int err;
 890
 891        if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 892                encap_limit = t->parms.encap_limit;
 893
 894        memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 895        fl6.flowi6_proto = skb->protocol;
 896
 897        err = ip6gre_xmit2(skb, dev, 0, &fl6, encap_limit, &mtu);
 898
 899        return err;
 900}
 901
 902static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 903        struct net_device *dev)
 904{
 905        struct ip6_tnl *t = netdev_priv(dev);
 906        struct net_device_stats *stats = &t->dev->stats;
 907        int ret;
 908
 909        if (!ip6_tnl_xmit_ctl(t))
 910                goto tx_err;
 911
 912        switch (skb->protocol) {
 913        case htons(ETH_P_IP):
 914                ret = ip6gre_xmit_ipv4(skb, dev);
 915                break;
 916        case htons(ETH_P_IPV6):
 917                ret = ip6gre_xmit_ipv6(skb, dev);
 918                break;
 919        default:
 920                ret = ip6gre_xmit_other(skb, dev);
 921                break;
 922        }
 923
 924        if (ret < 0)
 925                goto tx_err;
 926
 927        return NETDEV_TX_OK;
 928
 929tx_err:
 930        stats->tx_errors++;
 931        stats->tx_dropped++;
 932        kfree_skb(skb);
 933        return NETDEV_TX_OK;
 934}
 935
 936static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
 937{
 938        struct net_device *dev = t->dev;
 939        struct __ip6_tnl_parm *p = &t->parms;
 940        struct flowi6 *fl6 = &t->fl.u.ip6;
 941        int addend = sizeof(struct ipv6hdr) + 4;
 942
 943        if (dev->type != ARPHRD_ETHER) {
 944                memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
 945                memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
 946        }
 947
 948        /* Set up flowi template */
 949        fl6->saddr = p->laddr;
 950        fl6->daddr = p->raddr;
 951        fl6->flowi6_oif = p->link;
 952        fl6->flowlabel = 0;
 953
 954        if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
 955                fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
 956        if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
 957                fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
 958
 959        p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
 960        p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
 961
 962        if (p->flags&IP6_TNL_F_CAP_XMIT &&
 963                        p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
 964                dev->flags |= IFF_POINTOPOINT;
 965        else
 966                dev->flags &= ~IFF_POINTOPOINT;
 967
 968        dev->iflink = p->link;
 969
 970        /* Precalculate GRE options length */
 971        if (t->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
 972                if (t->parms.o_flags&GRE_CSUM)
 973                        addend += 4;
 974                if (t->parms.o_flags&GRE_KEY)
 975                        addend += 4;
 976                if (t->parms.o_flags&GRE_SEQ)
 977                        addend += 4;
 978        }
 979        t->hlen = addend;
 980
 981        if (p->flags & IP6_TNL_F_CAP_XMIT) {
 982                int strict = (ipv6_addr_type(&p->raddr) &
 983                              (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
 984
 985                struct rt6_info *rt = rt6_lookup(dev_net(dev),
 986                                                 &p->raddr, &p->laddr,
 987                                                 p->link, strict);
 988
 989                if (rt == NULL)
 990                        return;
 991
 992                if (rt->dst.dev) {
 993                        dev->hard_header_len = rt->dst.dev->hard_header_len + addend;
 994
 995                        if (set_mtu) {
 996                                dev->mtu = rt->dst.dev->mtu - addend;
 997                                if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 998                                        dev->mtu -= 8;
 999
1000                                if (dev->mtu < IPV6_MIN_MTU)
1001                                        dev->mtu = IPV6_MIN_MTU;
1002                        }
1003                }
1004                ip6_rt_put(rt);
1005        }
1006}
1007
1008static int ip6gre_tnl_change(struct ip6_tnl *t,
1009        const struct __ip6_tnl_parm *p, int set_mtu)
1010{
1011        t->parms.laddr = p->laddr;
1012        t->parms.raddr = p->raddr;
1013        t->parms.flags = p->flags;
1014        t->parms.hop_limit = p->hop_limit;
1015        t->parms.encap_limit = p->encap_limit;
1016        t->parms.flowinfo = p->flowinfo;
1017        t->parms.link = p->link;
1018        t->parms.proto = p->proto;
1019        t->parms.i_key = p->i_key;
1020        t->parms.o_key = p->o_key;
1021        t->parms.i_flags = p->i_flags;
1022        t->parms.o_flags = p->o_flags;
1023        ip6_tnl_dst_reset(t);
1024        ip6gre_tnl_link_config(t, set_mtu);
1025        return 0;
1026}
1027
1028static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1029        const struct ip6_tnl_parm2 *u)
1030{
1031        p->laddr = u->laddr;
1032        p->raddr = u->raddr;
1033        p->flags = u->flags;
1034        p->hop_limit = u->hop_limit;
1035        p->encap_limit = u->encap_limit;
1036        p->flowinfo = u->flowinfo;
1037        p->link = u->link;
1038        p->i_key = u->i_key;
1039        p->o_key = u->o_key;
1040        p->i_flags = u->i_flags;
1041        p->o_flags = u->o_flags;
1042        memcpy(p->name, u->name, sizeof(u->name));
1043}
1044
1045static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1046        const struct __ip6_tnl_parm *p)
1047{
1048        u->proto = IPPROTO_GRE;
1049        u->laddr = p->laddr;
1050        u->raddr = p->raddr;
1051        u->flags = p->flags;
1052        u->hop_limit = p->hop_limit;
1053        u->encap_limit = p->encap_limit;
1054        u->flowinfo = p->flowinfo;
1055        u->link = p->link;
1056        u->i_key = p->i_key;
1057        u->o_key = p->o_key;
1058        u->i_flags = p->i_flags;
1059        u->o_flags = p->o_flags;
1060        memcpy(u->name, p->name, sizeof(u->name));
1061}
1062
1063static int ip6gre_tunnel_ioctl(struct net_device *dev,
1064        struct ifreq *ifr, int cmd)
1065{
1066        int err = 0;
1067        struct ip6_tnl_parm2 p;
1068        struct __ip6_tnl_parm p1;
1069        struct ip6_tnl *t;
1070        struct net *net = dev_net(dev);
1071        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1072
1073        switch (cmd) {
1074        case SIOCGETTUNNEL:
1075                t = NULL;
1076                if (dev == ign->fb_tunnel_dev) {
1077                        if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1078                                err = -EFAULT;
1079                                break;
1080                        }
1081                        ip6gre_tnl_parm_from_user(&p1, &p);
1082                        t = ip6gre_tunnel_locate(net, &p1, 0);
1083                }
1084                if (t == NULL)
1085                        t = netdev_priv(dev);
1086                memset(&p, 0, sizeof(p));
1087                ip6gre_tnl_parm_to_user(&p, &t->parms);
1088                if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1089                        err = -EFAULT;
1090                break;
1091
1092        case SIOCADDTUNNEL:
1093        case SIOCCHGTUNNEL:
1094                err = -EPERM;
1095                if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1096                        goto done;
1097
1098                err = -EFAULT;
1099                if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1100                        goto done;
1101
1102                err = -EINVAL;
1103                if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1104                        goto done;
1105
1106                if (!(p.i_flags&GRE_KEY))
1107                        p.i_key = 0;
1108                if (!(p.o_flags&GRE_KEY))
1109                        p.o_key = 0;
1110
1111                ip6gre_tnl_parm_from_user(&p1, &p);
1112                t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1113
1114                if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1115                        if (t != NULL) {
1116                                if (t->dev != dev) {
1117                                        err = -EEXIST;
1118                                        break;
1119                                }
1120                        } else {
1121                                t = netdev_priv(dev);
1122
1123                                ip6gre_tunnel_unlink(ign, t);
1124                                synchronize_net();
1125                                ip6gre_tnl_change(t, &p1, 1);
1126                                ip6gre_tunnel_link(ign, t);
1127                                netdev_state_change(dev);
1128                        }
1129                }
1130
1131                if (t) {
1132                        err = 0;
1133
1134                        memset(&p, 0, sizeof(p));
1135                        ip6gre_tnl_parm_to_user(&p, &t->parms);
1136                        if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1137                                err = -EFAULT;
1138                } else
1139                        err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1140                break;
1141
1142        case SIOCDELTUNNEL:
1143                err = -EPERM;
1144                if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1145                        goto done;
1146
1147                if (dev == ign->fb_tunnel_dev) {
1148                        err = -EFAULT;
1149                        if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1150                                goto done;
1151                        err = -ENOENT;
1152                        ip6gre_tnl_parm_from_user(&p1, &p);
1153                        t = ip6gre_tunnel_locate(net, &p1, 0);
1154                        if (t == NULL)
1155                                goto done;
1156                        err = -EPERM;
1157                        if (t == netdev_priv(ign->fb_tunnel_dev))
1158                                goto done;
1159                        dev = t->dev;
1160                }
1161                unregister_netdevice(dev);
1162                err = 0;
1163                break;
1164
1165        default:
1166                err = -EINVAL;
1167        }
1168
1169done:
1170        return err;
1171}
1172
1173static int ip6gre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1174{
1175        if (new_mtu < 68 ||
1176            new_mtu > 0xFFF8 - dev->hard_header_len)
1177                return -EINVAL;
1178        dev->mtu = new_mtu;
1179        return 0;
1180}
1181
1182static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1183                        unsigned short type,
1184                        const void *daddr, const void *saddr, unsigned int len)
1185{
1186        struct ip6_tnl *t = netdev_priv(dev);
1187        struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
1188        __be16 *p = (__be16 *)(ipv6h+1);
1189
1190        ip6_flow_hdr(ipv6h, 0, t->fl.u.ip6.flowlabel);
1191        ipv6h->hop_limit = t->parms.hop_limit;
1192        ipv6h->nexthdr = NEXTHDR_GRE;
1193        ipv6h->saddr = t->parms.laddr;
1194        ipv6h->daddr = t->parms.raddr;
1195
1196        p[0]            = t->parms.o_flags;
1197        p[1]            = htons(type);
1198
1199        /*
1200         *      Set the source hardware address.
1201         */
1202
1203        if (saddr)
1204                memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1205        if (daddr)
1206                memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1207        if (!ipv6_addr_any(&ipv6h->daddr))
1208                return t->hlen;
1209
1210        return -t->hlen;
1211}
1212
1213static const struct header_ops ip6gre_header_ops = {
1214        .create = ip6gre_header,
1215};
1216
1217static const struct net_device_ops ip6gre_netdev_ops = {
1218        .ndo_init               = ip6gre_tunnel_init,
1219        .ndo_uninit             = ip6gre_tunnel_uninit,
1220        .ndo_start_xmit         = ip6gre_tunnel_xmit,
1221        .ndo_do_ioctl           = ip6gre_tunnel_ioctl,
1222        .ndo_change_mtu         = ip6gre_tunnel_change_mtu,
1223        .ndo_get_stats64        = ip_tunnel_get_stats64,
1224};
1225
1226static void ip6gre_dev_free(struct net_device *dev)
1227{
1228        free_percpu(dev->tstats);
1229        free_netdev(dev);
1230}
1231
1232static void ip6gre_tunnel_setup(struct net_device *dev)
1233{
1234        struct ip6_tnl *t;
1235
1236        dev->netdev_ops = &ip6gre_netdev_ops;
1237        dev->destructor = ip6gre_dev_free;
1238
1239        dev->type = ARPHRD_IP6GRE;
1240        dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr) + 4;
1241        dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr) - 4;
1242        t = netdev_priv(dev);
1243        if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1244                dev->mtu -= 8;
1245        dev->flags |= IFF_NOARP;
1246        dev->iflink = 0;
1247        dev->addr_len = sizeof(struct in6_addr);
1248        dev->features |= NETIF_F_NETNS_LOCAL;
1249        dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1250}
1251
1252static int ip6gre_tunnel_init(struct net_device *dev)
1253{
1254        struct ip6_tnl *tunnel;
1255        int i;
1256
1257        tunnel = netdev_priv(dev);
1258
1259        tunnel->dev = dev;
1260        tunnel->net = dev_net(dev);
1261        strcpy(tunnel->parms.name, dev->name);
1262
1263        memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1264        memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1265
1266        if (ipv6_addr_any(&tunnel->parms.raddr))
1267                dev->header_ops = &ip6gre_header_ops;
1268
1269        dev->tstats = alloc_percpu(struct pcpu_tstats);
1270        if (!dev->tstats)
1271                return -ENOMEM;
1272
1273        for_each_possible_cpu(i) {
1274                struct pcpu_tstats *ip6gre_tunnel_stats;
1275                ip6gre_tunnel_stats = per_cpu_ptr(dev->tstats, i);
1276                u64_stats_init(&ip6gre_tunnel_stats->syncp);
1277        }
1278
1279
1280        return 0;
1281}
1282
1283static void ip6gre_fb_tunnel_init(struct net_device *dev)
1284{
1285        struct ip6_tnl *tunnel = netdev_priv(dev);
1286
1287        tunnel->dev = dev;
1288        tunnel->net = dev_net(dev);
1289        strcpy(tunnel->parms.name, dev->name);
1290
1291        tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
1292
1293        dev_hold(dev);
1294}
1295
1296
1297static struct inet6_protocol ip6gre_protocol __read_mostly = {
1298        .handler     = ip6gre_rcv,
1299        .err_handler = ip6gre_err,
1300        .flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1301};
1302
1303static void ip6gre_destroy_tunnels(struct ip6gre_net *ign,
1304        struct list_head *head)
1305{
1306        int prio;
1307
1308        for (prio = 0; prio < 4; prio++) {
1309                int h;
1310                for (h = 0; h < HASH_SIZE; h++) {
1311                        struct ip6_tnl *t;
1312
1313                        t = rtnl_dereference(ign->tunnels[prio][h]);
1314
1315                        while (t != NULL) {
1316                                unregister_netdevice_queue(t->dev, head);
1317                                t = rtnl_dereference(t->next);
1318                        }
1319                }
1320        }
1321}
1322
1323static int __net_init ip6gre_init_net(struct net *net)
1324{
1325        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1326        int err;
1327
1328        ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1329                                           ip6gre_tunnel_setup);
1330        if (!ign->fb_tunnel_dev) {
1331                err = -ENOMEM;
1332                goto err_alloc_dev;
1333        }
1334        dev_net_set(ign->fb_tunnel_dev, net);
1335
1336        ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1337        ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1338
1339        err = register_netdev(ign->fb_tunnel_dev);
1340        if (err)
1341                goto err_reg_dev;
1342
1343        rcu_assign_pointer(ign->tunnels_wc[0],
1344                           netdev_priv(ign->fb_tunnel_dev));
1345        return 0;
1346
1347err_reg_dev:
1348        ip6gre_dev_free(ign->fb_tunnel_dev);
1349err_alloc_dev:
1350        return err;
1351}
1352
1353static void __net_exit ip6gre_exit_net(struct net *net)
1354{
1355        struct ip6gre_net *ign;
1356        LIST_HEAD(list);
1357
1358        ign = net_generic(net, ip6gre_net_id);
1359        rtnl_lock();
1360        ip6gre_destroy_tunnels(ign, &list);
1361        unregister_netdevice_many(&list);
1362        rtnl_unlock();
1363}
1364
1365static struct pernet_operations ip6gre_net_ops = {
1366        .init = ip6gre_init_net,
1367        .exit = ip6gre_exit_net,
1368        .id   = &ip6gre_net_id,
1369        .size = sizeof(struct ip6gre_net),
1370};
1371
1372static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1373{
1374        __be16 flags;
1375
1376        if (!data)
1377                return 0;
1378
1379        flags = 0;
1380        if (data[IFLA_GRE_IFLAGS])
1381                flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1382        if (data[IFLA_GRE_OFLAGS])
1383                flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1384        if (flags & (GRE_VERSION|GRE_ROUTING))
1385                return -EINVAL;
1386
1387        return 0;
1388}
1389
1390static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1391{
1392        struct in6_addr daddr;
1393
1394        if (tb[IFLA_ADDRESS]) {
1395                if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1396                        return -EINVAL;
1397                if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1398                        return -EADDRNOTAVAIL;
1399        }
1400
1401        if (!data)
1402                goto out;
1403
1404        if (data[IFLA_GRE_REMOTE]) {
1405                nla_memcpy(&daddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1406                if (ipv6_addr_any(&daddr))
1407                        return -EINVAL;
1408        }
1409
1410out:
1411        return ip6gre_tunnel_validate(tb, data);
1412}
1413
1414
1415static void ip6gre_netlink_parms(struct nlattr *data[],
1416                                struct __ip6_tnl_parm *parms)
1417{
1418        memset(parms, 0, sizeof(*parms));
1419
1420        if (!data)
1421                return;
1422
1423        if (data[IFLA_GRE_LINK])
1424                parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1425
1426        if (data[IFLA_GRE_IFLAGS])
1427                parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1428
1429        if (data[IFLA_GRE_OFLAGS])
1430                parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1431
1432        if (data[IFLA_GRE_IKEY])
1433                parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1434
1435        if (data[IFLA_GRE_OKEY])
1436                parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1437
1438        if (data[IFLA_GRE_LOCAL])
1439                nla_memcpy(&parms->laddr, data[IFLA_GRE_LOCAL], sizeof(struct in6_addr));
1440
1441        if (data[IFLA_GRE_REMOTE])
1442                nla_memcpy(&parms->raddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1443
1444        if (data[IFLA_GRE_TTL])
1445                parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1446
1447        if (data[IFLA_GRE_ENCAP_LIMIT])
1448                parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1449
1450        if (data[IFLA_GRE_FLOWINFO])
1451                parms->flowinfo = nla_get_u32(data[IFLA_GRE_FLOWINFO]);
1452
1453        if (data[IFLA_GRE_FLAGS])
1454                parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1455}
1456
1457static int ip6gre_tap_init(struct net_device *dev)
1458{
1459        struct ip6_tnl *tunnel;
1460        int i;
1461
1462        tunnel = netdev_priv(dev);
1463
1464        tunnel->dev = dev;
1465        tunnel->net = dev_net(dev);
1466        strcpy(tunnel->parms.name, dev->name);
1467
1468        ip6gre_tnl_link_config(tunnel, 1);
1469
1470        dev->tstats = alloc_percpu(struct pcpu_tstats);
1471        if (!dev->tstats)
1472                return -ENOMEM;
1473
1474        for_each_possible_cpu(i) {
1475                struct pcpu_tstats *ip6gre_tap_stats;
1476                ip6gre_tap_stats = per_cpu_ptr(dev->tstats, i);
1477                u64_stats_init(&ip6gre_tap_stats->syncp);
1478        }
1479
1480        return 0;
1481}
1482
1483static const struct net_device_ops ip6gre_tap_netdev_ops = {
1484        .ndo_init = ip6gre_tap_init,
1485        .ndo_uninit = ip6gre_tunnel_uninit,
1486        .ndo_start_xmit = ip6gre_tunnel_xmit,
1487        .ndo_set_mac_address = eth_mac_addr,
1488        .ndo_validate_addr = eth_validate_addr,
1489        .ndo_change_mtu = ip6gre_tunnel_change_mtu,
1490        .ndo_get_stats64 = ip_tunnel_get_stats64,
1491};
1492
1493static void ip6gre_tap_setup(struct net_device *dev)
1494{
1495
1496        ether_setup(dev);
1497
1498        dev->netdev_ops = &ip6gre_tap_netdev_ops;
1499        dev->destructor = ip6gre_dev_free;
1500
1501        dev->iflink = 0;
1502        dev->features |= NETIF_F_NETNS_LOCAL;
1503}
1504
1505static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1506        struct nlattr *tb[], struct nlattr *data[])
1507{
1508        struct ip6_tnl *nt;
1509        struct net *net = dev_net(dev);
1510        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1511        int err;
1512
1513        nt = netdev_priv(dev);
1514        ip6gre_netlink_parms(data, &nt->parms);
1515
1516        if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1517                return -EEXIST;
1518
1519        if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1520                eth_hw_addr_random(dev);
1521
1522        nt->dev = dev;
1523        nt->net = dev_net(dev);
1524        ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1525
1526        /* Can use a lockless transmit, unless we generate output sequences */
1527        if (!(nt->parms.o_flags & GRE_SEQ))
1528                dev->features |= NETIF_F_LLTX;
1529
1530        err = register_netdevice(dev);
1531        if (err)
1532                goto out;
1533
1534        dev_hold(dev);
1535        ip6gre_tunnel_link(ign, nt);
1536
1537out:
1538        return err;
1539}
1540
1541static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1542                            struct nlattr *data[])
1543{
1544        struct ip6_tnl *t, *nt;
1545        struct net *net = dev_net(dev);
1546        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1547        struct __ip6_tnl_parm p;
1548
1549        if (dev == ign->fb_tunnel_dev)
1550                return -EINVAL;
1551
1552        nt = netdev_priv(dev);
1553        ip6gre_netlink_parms(data, &p);
1554
1555        t = ip6gre_tunnel_locate(net, &p, 0);
1556
1557        if (t) {
1558                if (t->dev != dev)
1559                        return -EEXIST;
1560        } else {
1561                t = nt;
1562
1563                ip6gre_tunnel_unlink(ign, t);
1564                ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1565                ip6gre_tunnel_link(ign, t);
1566                netdev_state_change(dev);
1567        }
1568
1569        return 0;
1570}
1571
1572static size_t ip6gre_get_size(const struct net_device *dev)
1573{
1574        return
1575                /* IFLA_GRE_LINK */
1576                nla_total_size(4) +
1577                /* IFLA_GRE_IFLAGS */
1578                nla_total_size(2) +
1579                /* IFLA_GRE_OFLAGS */
1580                nla_total_size(2) +
1581                /* IFLA_GRE_IKEY */
1582                nla_total_size(4) +
1583                /* IFLA_GRE_OKEY */
1584                nla_total_size(4) +
1585                /* IFLA_GRE_LOCAL */
1586                nla_total_size(sizeof(struct in6_addr)) +
1587                /* IFLA_GRE_REMOTE */
1588                nla_total_size(sizeof(struct in6_addr)) +
1589                /* IFLA_GRE_TTL */
1590                nla_total_size(1) +
1591                /* IFLA_GRE_TOS */
1592                nla_total_size(1) +
1593                /* IFLA_GRE_ENCAP_LIMIT */
1594                nla_total_size(1) +
1595                /* IFLA_GRE_FLOWINFO */
1596                nla_total_size(4) +
1597                /* IFLA_GRE_FLAGS */
1598                nla_total_size(4) +
1599                0;
1600}
1601
1602static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1603{
1604        struct ip6_tnl *t = netdev_priv(dev);
1605        struct __ip6_tnl_parm *p = &t->parms;
1606
1607        if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1608            nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1609            nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1610            nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1611            nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1612            nla_put(skb, IFLA_GRE_LOCAL, sizeof(struct in6_addr), &p->laddr) ||
1613            nla_put(skb, IFLA_GRE_REMOTE, sizeof(struct in6_addr), &p->raddr) ||
1614            nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1615            /*nla_put_u8(skb, IFLA_GRE_TOS, t->priority) ||*/
1616            nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1617            nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1618            nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1619                goto nla_put_failure;
1620        return 0;
1621
1622nla_put_failure:
1623        return -EMSGSIZE;
1624}
1625
1626static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1627        [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1628        [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1629        [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1630        [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1631        [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1632        [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1633        [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1634        [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1635        [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1636        [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1637        [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1638};
1639
1640static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1641        .kind           = "ip6gre",
1642        .maxtype        = IFLA_GRE_MAX,
1643        .policy         = ip6gre_policy,
1644        .priv_size      = sizeof(struct ip6_tnl),
1645        .setup          = ip6gre_tunnel_setup,
1646        .validate       = ip6gre_tunnel_validate,
1647        .newlink        = ip6gre_newlink,
1648        .changelink     = ip6gre_changelink,
1649        .get_size       = ip6gre_get_size,
1650        .fill_info      = ip6gre_fill_info,
1651};
1652
1653static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1654        .kind           = "ip6gretap",
1655        .maxtype        = IFLA_GRE_MAX,
1656        .policy         = ip6gre_policy,
1657        .priv_size      = sizeof(struct ip6_tnl),
1658        .setup          = ip6gre_tap_setup,
1659        .validate       = ip6gre_tap_validate,
1660        .newlink        = ip6gre_newlink,
1661        .changelink     = ip6gre_changelink,
1662        .get_size       = ip6gre_get_size,
1663        .fill_info      = ip6gre_fill_info,
1664};
1665
1666/*
1667 *      And now the modules code and kernel interface.
1668 */
1669
1670static int __init ip6gre_init(void)
1671{
1672        int err;
1673
1674        pr_info("GRE over IPv6 tunneling driver\n");
1675
1676        err = register_pernet_device(&ip6gre_net_ops);
1677        if (err < 0)
1678                return err;
1679
1680        err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1681        if (err < 0) {
1682                pr_info("%s: can't add protocol\n", __func__);
1683                goto add_proto_failed;
1684        }
1685
1686        err = rtnl_link_register(&ip6gre_link_ops);
1687        if (err < 0)
1688                goto rtnl_link_failed;
1689
1690        err = rtnl_link_register(&ip6gre_tap_ops);
1691        if (err < 0)
1692                goto tap_ops_failed;
1693
1694out:
1695        return err;
1696
1697tap_ops_failed:
1698        rtnl_link_unregister(&ip6gre_link_ops);
1699rtnl_link_failed:
1700        inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1701add_proto_failed:
1702        unregister_pernet_device(&ip6gre_net_ops);
1703        goto out;
1704}
1705
1706static void __exit ip6gre_fini(void)
1707{
1708        rtnl_link_unregister(&ip6gre_tap_ops);
1709        rtnl_link_unregister(&ip6gre_link_ops);
1710        inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1711        unregister_pernet_device(&ip6gre_net_ops);
1712}
1713
1714module_init(ip6gre_init);
1715module_exit(ip6gre_fini);
1716MODULE_LICENSE("GPL");
1717MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1718MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1719MODULE_ALIAS_RTNL_LINK("ip6gre");
1720MODULE_ALIAS_NETDEV("ip6gre0");
1721