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