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/icmp.h>
  42#include <net/protocol.h>
  43#include <net/addrconf.h>
  44#include <net/arp.h>
  45#include <net/checksum.h>
  46#include <net/dsfield.h>
  47#include <net/inet_ecn.h>
  48#include <net/xfrm.h>
  49#include <net/net_namespace.h>
  50#include <net/netns/generic.h>
  51#include <net/rtnetlink.h>
  52
  53#include <net/ipv6.h>
  54#include <net/ip6_fib.h>
  55#include <net/ip6_route.h>
  56#include <net/ip6_tunnel.h>
  57
  58
  59static bool log_ecn_error = true;
  60module_param(log_ecn_error, bool, 0644);
  61MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  62
  63#define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
  64#define IPV6_TCLASS_SHIFT 20
  65
  66#define HASH_SIZE_SHIFT  5
  67#define HASH_SIZE (1 << HASH_SIZE_SHIFT)
  68
  69static int ip6gre_net_id __read_mostly;
  70struct ip6gre_net {
  71        struct ip6_tnl __rcu *tunnels[4][HASH_SIZE];
  72
  73        struct net_device *fb_tunnel_dev;
  74};
  75
  76static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
  77static int ip6gre_tunnel_init(struct net_device *dev);
  78static void ip6gre_tunnel_setup(struct net_device *dev);
  79static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
  80static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
  81
  82/* Tunnel hash table */
  83
  84/*
  85   4 hash tables:
  86
  87   3: (remote,local)
  88   2: (remote,*)
  89   1: (*,local)
  90   0: (*,*)
  91
  92   We require exact key match i.e. if a key is present in packet
  93   it will match only tunnel with the same key; if it is not present,
  94   it will match only keyless tunnel.
  95
  96   All keysless packets, if not matched configured keyless tunnels
  97   will match fallback tunnel.
  98 */
  99
 100#define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(HASH_SIZE - 1))
 101static u32 HASH_ADDR(const struct in6_addr *addr)
 102{
 103        u32 hash = ipv6_addr_hash(addr);
 104
 105        return hash_32(hash, HASH_SIZE_SHIFT);
 106}
 107
 108#define tunnels_r_l     tunnels[3]
 109#define tunnels_r       tunnels[2]
 110#define tunnels_l       tunnels[1]
 111#define tunnels_wc      tunnels[0]
 112/*
 113 * Locking : hash tables are protected by RCU and RTNL
 114 */
 115
 116#define for_each_ip_tunnel_rcu(start) \
 117        for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
 118
 119/* often modified stats are per cpu, other are shared (netdev->stats) */
 120struct pcpu_tstats {
 121        u64     rx_packets;
 122        u64     rx_bytes;
 123        u64     tx_packets;
 124        u64     tx_bytes;
 125        struct u64_stats_sync   syncp;
 126};
 127
 128static struct rtnl_link_stats64 *ip6gre_get_stats64(struct net_device *dev,
 129                struct rtnl_link_stats64 *tot)
 130{
 131        int i;
 132
 133        for_each_possible_cpu(i) {
 134                const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
 135                u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
 136                unsigned int start;
 137
 138                do {
 139                        start = u64_stats_fetch_begin_bh(&tstats->syncp);
 140                        rx_packets = tstats->rx_packets;
 141                        tx_packets = tstats->tx_packets;
 142                        rx_bytes = tstats->rx_bytes;
 143                        tx_bytes = tstats->tx_bytes;
 144                } while (u64_stats_fetch_retry_bh(&tstats->syncp, start));
 145
 146                tot->rx_packets += rx_packets;
 147                tot->tx_packets += tx_packets;
 148                tot->rx_bytes   += rx_bytes;
 149                tot->tx_bytes   += tx_bytes;
 150        }
 151
 152        tot->multicast = dev->stats.multicast;
 153        tot->rx_crc_errors = dev->stats.rx_crc_errors;
 154        tot->rx_fifo_errors = dev->stats.rx_fifo_errors;
 155        tot->rx_length_errors = dev->stats.rx_length_errors;
 156        tot->rx_frame_errors = dev->stats.rx_frame_errors;
 157        tot->rx_errors = dev->stats.rx_errors;
 158
 159        tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
 160        tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
 161        tot->tx_dropped = dev->stats.tx_dropped;
 162        tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
 163        tot->tx_errors = dev->stats.tx_errors;
 164
 165        return tot;
 166}
 167
 168/* Given src, dst and key, find appropriate for input tunnel. */
 169
 170static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 171                const struct in6_addr *remote, const struct in6_addr *local,
 172                __be32 key, __be16 gre_proto)
 173{
 174        struct net *net = dev_net(dev);
 175        int link = dev->ifindex;
 176        unsigned int h0 = HASH_ADDR(remote);
 177        unsigned int h1 = HASH_KEY(key);
 178        struct ip6_tnl *t, *cand = NULL;
 179        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 180        int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
 181                       ARPHRD_ETHER : ARPHRD_IP6GRE;
 182        int score, cand_score = 4;
 183
 184        for_each_ip_tunnel_rcu(ign->tunnels_r_l[h0 ^ h1]) {
 185                if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 186                    !ipv6_addr_equal(remote, &t->parms.raddr) ||
 187                    key != t->parms.i_key ||
 188                    !(t->dev->flags & IFF_UP))
 189                        continue;
 190
 191                if (t->dev->type != ARPHRD_IP6GRE &&
 192                    t->dev->type != dev_type)
 193                        continue;
 194
 195                score = 0;
 196                if (t->parms.link != link)
 197                        score |= 1;
 198                if (t->dev->type != dev_type)
 199                        score |= 2;
 200                if (score == 0)
 201                        return t;
 202
 203                if (score < cand_score) {
 204                        cand = t;
 205                        cand_score = score;
 206                }
 207        }
 208
 209        for_each_ip_tunnel_rcu(ign->tunnels_r[h0 ^ h1]) {
 210                if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
 211                    key != t->parms.i_key ||
 212                    !(t->dev->flags & IFF_UP))
 213                        continue;
 214
 215                if (t->dev->type != ARPHRD_IP6GRE &&
 216                    t->dev->type != dev_type)
 217                        continue;
 218
 219                score = 0;
 220                if (t->parms.link != link)
 221                        score |= 1;
 222                if (t->dev->type != dev_type)
 223                        score |= 2;
 224                if (score == 0)
 225                        return t;
 226
 227                if (score < cand_score) {
 228                        cand = t;
 229                        cand_score = score;
 230                }
 231        }
 232
 233        for_each_ip_tunnel_rcu(ign->tunnels_l[h1]) {
 234                if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
 235                          (!ipv6_addr_equal(local, &t->parms.raddr) ||
 236                                 !ipv6_addr_is_multicast(local))) ||
 237                    key != t->parms.i_key ||
 238                    !(t->dev->flags & IFF_UP))
 239                        continue;
 240
 241                if (t->dev->type != ARPHRD_IP6GRE &&
 242                    t->dev->type != dev_type)
 243                        continue;
 244
 245                score = 0;
 246                if (t->parms.link != link)
 247                        score |= 1;
 248                if (t->dev->type != dev_type)
 249                        score |= 2;
 250                if (score == 0)
 251                        return t;
 252
 253                if (score < cand_score) {
 254                        cand = t;
 255                        cand_score = score;
 256                }
 257        }
 258
 259        for_each_ip_tunnel_rcu(ign->tunnels_wc[h1]) {
 260                if (t->parms.i_key != key ||
 261                    !(t->dev->flags & IFF_UP))
 262                        continue;
 263
 264                if (t->dev->type != ARPHRD_IP6GRE &&
 265                    t->dev->type != dev_type)
 266                        continue;
 267
 268                score = 0;
 269                if (t->parms.link != link)
 270                        score |= 1;
 271                if (t->dev->type != dev_type)
 272                        score |= 2;
 273                if (score == 0)
 274                        return t;
 275
 276                if (score < cand_score) {
 277                        cand = t;
 278                        cand_score = score;
 279                }
 280        }
 281
 282        if (cand != NULL)
 283                return cand;
 284
 285        dev = ign->fb_tunnel_dev;
 286        if (dev->flags & IFF_UP)
 287                return netdev_priv(dev);
 288
 289        return NULL;
 290}
 291
 292static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
 293                const struct __ip6_tnl_parm *p)
 294{
 295        const struct in6_addr *remote = &p->raddr;
 296        const struct in6_addr *local = &p->laddr;
 297        unsigned int h = HASH_KEY(p->i_key);
 298        int prio = 0;
 299
 300        if (!ipv6_addr_any(local))
 301                prio |= 1;
 302        if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
 303                prio |= 2;
 304                h ^= HASH_ADDR(remote);
 305        }
 306
 307        return &ign->tunnels[prio][h];
 308}
 309
 310static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
 311                const struct ip6_tnl *t)
 312{
 313        return __ip6gre_bucket(ign, &t->parms);
 314}
 315
 316static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
 317{
 318        struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
 319
 320        rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 321        rcu_assign_pointer(*tp, t);
 322}
 323
 324static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
 325{
 326        struct ip6_tnl __rcu **tp;
 327        struct ip6_tnl *iter;
 328
 329        for (tp = ip6gre_bucket(ign, t);
 330             (iter = rtnl_dereference(*tp)) != NULL;
 331             tp = &iter->next) {
 332                if (t == iter) {
 333                        rcu_assign_pointer(*tp, t->next);
 334                        break;
 335                }
 336        }
 337}
 338
 339static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
 340                                           const struct __ip6_tnl_parm *parms,
 341                                           int type)
 342{
 343        const struct in6_addr *remote = &parms->raddr;
 344        const struct in6_addr *local = &parms->laddr;
 345        __be32 key = parms->i_key;
 346        int link = parms->link;
 347        struct ip6_tnl *t;
 348        struct ip6_tnl __rcu **tp;
 349        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 350
 351        for (tp = __ip6gre_bucket(ign, parms);
 352             (t = rtnl_dereference(*tp)) != NULL;
 353             tp = &t->next)
 354                if (ipv6_addr_equal(local, &t->parms.laddr) &&
 355                    ipv6_addr_equal(remote, &t->parms.raddr) &&
 356                    key == t->parms.i_key &&
 357                    link == t->parms.link &&
 358                    type == t->dev->type)
 359                        break;
 360
 361        return t;
 362}
 363
 364static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
 365                const struct __ip6_tnl_parm *parms, int create)
 366{
 367        struct ip6_tnl *t, *nt;
 368        struct net_device *dev;
 369        char name[IFNAMSIZ];
 370        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 371
 372        t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
 373        if (t || !create)
 374                return t;
 375
 376        if (parms->name[0])
 377                strlcpy(name, parms->name, IFNAMSIZ);
 378        else
 379                strcpy(name, "ip6gre%d");
 380
 381        dev = alloc_netdev(sizeof(*t), name, ip6gre_tunnel_setup);
 382        if (!dev)
 383                return NULL;
 384
 385        dev_net_set(dev, net);
 386
 387        nt = netdev_priv(dev);
 388        nt->parms = *parms;
 389        dev->rtnl_link_ops = &ip6gre_link_ops;
 390
 391        nt->dev = dev;
 392        ip6gre_tnl_link_config(nt, 1);
 393
 394        if (register_netdevice(dev) < 0)
 395                goto failed_free;
 396
 397        /* Can use a lockless transmit, unless we generate output sequences */
 398        if (!(nt->parms.o_flags & GRE_SEQ))
 399                dev->features |= NETIF_F_LLTX;
 400
 401        dev_hold(dev);
 402        ip6gre_tunnel_link(ign, nt);
 403        return nt;
 404
 405failed_free:
 406        free_netdev(dev);
 407        return NULL;
 408}
 409
 410static void ip6gre_tunnel_uninit(struct net_device *dev)
 411{
 412        struct net *net = dev_net(dev);
 413        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 414
 415        ip6gre_tunnel_unlink(ign, netdev_priv(dev));
 416        dev_put(dev);
 417}
 418
 419
 420static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 421                u8 type, u8 code, int offset, __be32 info)
 422{
 423        const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 424        __be16 *p = (__be16 *)(skb->data + offset);
 425        int grehlen = offset + 4;
 426        struct ip6_tnl *t;
 427        __be16 flags;
 428
 429        flags = p[0];
 430        if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
 431                if (flags&(GRE_VERSION|GRE_ROUTING))
 432                        return;
 433                if (flags&GRE_KEY) {
 434                        grehlen += 4;
 435                        if (flags&GRE_CSUM)
 436                                grehlen += 4;
 437                }
 438        }
 439
 440        /* If only 8 bytes returned, keyed message will be dropped here */
 441        if (!pskb_may_pull(skb, grehlen))
 442                return;
 443        ipv6h = (const struct ipv6hdr *)skb->data;
 444        p = (__be16 *)(skb->data + offset);
 445
 446        t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
 447                                flags & GRE_KEY ?
 448                                *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
 449                                p[1]);
 450        if (t == NULL)
 451                return;
 452
 453        switch (type) {
 454                __u32 teli;
 455                struct ipv6_tlv_tnl_enc_lim *tel;
 456                __u32 mtu;
 457        case ICMPV6_DEST_UNREACH:
 458                net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
 459                                     t->parms.name);
 460                break;
 461        case ICMPV6_TIME_EXCEED:
 462                if (code == ICMPV6_EXC_HOPLIMIT) {
 463                        net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 464                                             t->parms.name);
 465                }
 466                break;
 467        case ICMPV6_PARAMPROB:
 468                teli = 0;
 469                if (code == ICMPV6_HDR_FIELD)
 470                        teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 471
 472                if (teli && teli == info - 2) {
 473                        tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 474                        if (tel->encap_limit == 0) {
 475                                net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 476                                                     t->parms.name);
 477                        }
 478                } else {
 479                        net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 480                                             t->parms.name);
 481                }
 482                break;
 483        case ICMPV6_PKT_TOOBIG:
 484                mtu = info - offset;
 485                if (mtu < IPV6_MIN_MTU)
 486                        mtu = IPV6_MIN_MTU;
 487                t->dev->mtu = mtu;
 488                break;
 489        }
 490
 491        if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
 492                t->err_count++;
 493        else
 494                t->err_count = 1;
 495        t->err_time = jiffies;
 496}
 497
 498static int ip6gre_rcv(struct sk_buff *skb)
 499{
 500        const struct ipv6hdr *ipv6h;
 501        u8     *h;
 502        __be16    flags;
 503        __sum16   csum = 0;
 504        __be32 key = 0;
 505        u32    seqno = 0;
 506        struct ip6_tnl *tunnel;
 507        int    offset = 4;
 508        __be16 gre_proto;
 509        int err;
 510
 511        if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
 512                goto drop;
 513
 514        ipv6h = ipv6_hdr(skb);
 515        h = skb->data;
 516        flags = *(__be16 *)h;
 517
 518        if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
 519                /* - Version must be 0.
 520                   - We do not support routing headers.
 521                 */
 522                if (flags&(GRE_VERSION|GRE_ROUTING))
 523                        goto drop;
 524
 525                if (flags&GRE_CSUM) {
 526                        switch (skb->ip_summed) {
 527                        case CHECKSUM_COMPLETE:
 528                                csum = csum_fold(skb->csum);
 529                                if (!csum)
 530                                        break;
 531                                /* fall through */
 532                        case CHECKSUM_NONE:
 533                                skb->csum = 0;
 534                                csum = __skb_checksum_complete(skb);
 535                                skb->ip_summed = CHECKSUM_COMPLETE;
 536                        }
 537                        offset += 4;
 538                }
 539                if (flags&GRE_KEY) {
 540                        key = *(__be32 *)(h + offset);
 541                        offset += 4;
 542                }
 543                if (flags&GRE_SEQ) {
 544                        seqno = ntohl(*(__be32 *)(h + offset));
 545                        offset += 4;
 546                }
 547        }
 548
 549        gre_proto = *(__be16 *)(h + 2);
 550
 551        tunnel = ip6gre_tunnel_lookup(skb->dev,
 552                                          &ipv6h->saddr, &ipv6h->daddr, key,
 553                                          gre_proto);
 554        if (tunnel) {
 555                struct pcpu_tstats *tstats;
 556
 557                if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 558                        goto drop;
 559
 560                if (!ip6_tnl_rcv_ctl(tunnel, &ipv6h->daddr, &ipv6h->saddr)) {
 561                        tunnel->dev->stats.rx_dropped++;
 562                        goto drop;
 563                }
 564
 565                secpath_reset(skb);
 566
 567                skb->protocol = gre_proto;
 568                /* WCCP version 1 and 2 protocol decoding.
 569                 * - Change protocol to IP
 570                 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
 571                 */
 572                if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
 573                        skb->protocol = htons(ETH_P_IP);
 574                        if ((*(h + offset) & 0xF0) != 0x40)
 575                                offset += 4;
 576                }
 577
 578                skb->mac_header = skb->network_header;
 579                __pskb_pull(skb, offset);
 580                skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
 581                skb->pkt_type = PACKET_HOST;
 582
 583                if (((flags&GRE_CSUM) && csum) ||
 584                    (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
 585                        tunnel->dev->stats.rx_crc_errors++;
 586                        tunnel->dev->stats.rx_errors++;
 587                        goto drop;
 588                }
 589                if (tunnel->parms.i_flags&GRE_SEQ) {
 590                        if (!(flags&GRE_SEQ) ||
 591                            (tunnel->i_seqno &&
 592                                        (s32)(seqno - tunnel->i_seqno) < 0)) {
 593                                tunnel->dev->stats.rx_fifo_errors++;
 594                                tunnel->dev->stats.rx_errors++;
 595                                goto drop;
 596                        }
 597                        tunnel->i_seqno = seqno + 1;
 598                }
 599
 600                /* Warning: All skb pointers will be invalidated! */
 601                if (tunnel->dev->type == ARPHRD_ETHER) {
 602                        if (!pskb_may_pull(skb, ETH_HLEN)) {
 603                                tunnel->dev->stats.rx_length_errors++;
 604                                tunnel->dev->stats.rx_errors++;
 605                                goto drop;
 606                        }
 607
 608                        ipv6h = ipv6_hdr(skb);
 609                        skb->protocol = eth_type_trans(skb, tunnel->dev);
 610                        skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 611                }
 612
 613                __skb_tunnel_rx(skb, tunnel->dev);
 614
 615                skb_reset_network_header(skb);
 616
 617                err = IP6_ECN_decapsulate(ipv6h, skb);
 618                if (unlikely(err)) {
 619                        if (log_ecn_error)
 620                                net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
 621                                                     &ipv6h->saddr,
 622                                                     ipv6_get_dsfield(ipv6h));
 623                        if (err > 1) {
 624                                ++tunnel->dev->stats.rx_frame_errors;
 625                                ++tunnel->dev->stats.rx_errors;
 626                                goto drop;
 627                        }
 628                }
 629
 630                tstats = this_cpu_ptr(tunnel->dev->tstats);
 631                u64_stats_update_begin(&tstats->syncp);
 632                tstats->rx_packets++;
 633                tstats->rx_bytes += skb->len;
 634                u64_stats_update_end(&tstats->syncp);
 635
 636                netif_rx(skb);
 637
 638                return 0;
 639        }
 640        icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 641
 642drop:
 643        kfree_skb(skb);
 644        return 0;
 645}
 646
 647struct ipv6_tel_txoption {
 648        struct ipv6_txoptions ops;
 649        __u8 dst_opt[8];
 650};
 651
 652static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 653{
 654        memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 655
 656        opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 657        opt->dst_opt[3] = 1;
 658        opt->dst_opt[4] = encap_limit;
 659        opt->dst_opt[5] = IPV6_TLV_PADN;
 660        opt->dst_opt[6] = 1;
 661
 662        opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 663        opt->ops.opt_nflen = 8;
 664}
 665
 666static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
 667                         struct net_device *dev,
 668                         __u8 dsfield,
 669                         struct flowi6 *fl6,
 670                         int encap_limit,
 671                         __u32 *pmtu)
 672{
 673        struct net *net = dev_net(dev);
 674        struct ip6_tnl *tunnel = netdev_priv(dev);
 675        struct net_device *tdev;    /* Device to other host */
 676        struct ipv6hdr  *ipv6h;     /* Our new IP header */
 677        unsigned int max_headroom;  /* The extra header space needed */
 678        int    gre_hlen;
 679        struct ipv6_tel_txoption opt;
 680        int    mtu;
 681        struct dst_entry *dst = NULL, *ndst = NULL;
 682        struct net_device_stats *stats = &tunnel->dev->stats;
 683        int err = -1;
 684        u8 proto;
 685        int pkt_len;
 686        struct sk_buff *new_skb;
 687
 688        if (dev->type == ARPHRD_ETHER)
 689                IPCB(skb)->flags = 0;
 690
 691        if (dev->header_ops && dev->type == ARPHRD_IP6GRE) {
 692                gre_hlen = 0;
 693                ipv6h = (struct ipv6hdr *)skb->data;
 694                fl6->daddr = ipv6h->daddr;
 695        } else {
 696                gre_hlen = tunnel->hlen;
 697                fl6->daddr = tunnel->parms.raddr;
 698        }
 699
 700        if (!fl6->flowi6_mark)
 701                dst = ip6_tnl_dst_check(tunnel);
 702
 703        if (!dst) {
 704                ndst = ip6_route_output(net, NULL, fl6);
 705
 706                if (ndst->error)
 707                        goto tx_err_link_failure;
 708                ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
 709                if (IS_ERR(ndst)) {
 710                        err = PTR_ERR(ndst);
 711                        ndst = NULL;
 712                        goto tx_err_link_failure;
 713                }
 714                dst = ndst;
 715        }
 716
 717        tdev = dst->dev;
 718
 719        if (tdev == dev) {
 720                stats->collisions++;
 721                net_warn_ratelimited("%s: Local routing loop detected!\n",
 722                                     tunnel->parms.name);
 723                goto tx_err_dst_release;
 724        }
 725
 726        mtu = dst_mtu(dst) - sizeof(*ipv6h);
 727        if (encap_limit >= 0) {
 728                max_headroom += 8;
 729                mtu -= 8;
 730        }
 731        if (mtu < IPV6_MIN_MTU)
 732                mtu = IPV6_MIN_MTU;
 733        if (skb_dst(skb))
 734                skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 735        if (skb->len > mtu) {
 736                *pmtu = mtu;
 737                err = -EMSGSIZE;
 738                goto tx_err_dst_release;
 739        }
 740
 741        if (tunnel->err_count > 0) {
 742                if (time_before(jiffies,
 743                                tunnel->err_time + IP6TUNNEL_ERR_TIMEO)) {
 744                        tunnel->err_count--;
 745
 746                        dst_link_failure(skb);
 747                } else
 748                        tunnel->err_count = 0;
 749        }
 750
 751        max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
 752
 753        if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 754            (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 755                new_skb = skb_realloc_headroom(skb, max_headroom);
 756                if (max_headroom > dev->needed_headroom)
 757                        dev->needed_headroom = max_headroom;
 758                if (!new_skb)
 759                        goto tx_err_dst_release;
 760
 761                if (skb->sk)
 762                        skb_set_owner_w(new_skb, skb->sk);
 763                consume_skb(skb);
 764                skb = new_skb;
 765        }
 766
 767        skb_dst_drop(skb);
 768
 769        if (fl6->flowi6_mark) {
 770                skb_dst_set(skb, dst);
 771                ndst = NULL;
 772        } else {
 773                skb_dst_set_noref(skb, dst);
 774        }
 775
 776        skb->transport_header = skb->network_header;
 777
 778        proto = NEXTHDR_GRE;
 779        if (encap_limit >= 0) {
 780                init_tel_txopt(&opt, encap_limit);
 781                ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
 782        }
 783
 784        skb_push(skb, gre_hlen);
 785        skb_reset_network_header(skb);
 786
 787        /*
 788         *      Push down and install the IP header.
 789         */
 790        ipv6h = ipv6_hdr(skb);
 791        *(__be32 *)ipv6h = fl6->flowlabel | htonl(0x60000000);
 792        dsfield = INET_ECN_encapsulate(0, dsfield);
 793        ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield);
 794        ipv6h->hop_limit = tunnel->parms.hop_limit;
 795        ipv6h->nexthdr = proto;
 796        ipv6h->saddr = fl6->saddr;
 797        ipv6h->daddr = fl6->daddr;
 798
 799        ((__be16 *)(ipv6h + 1))[0] = tunnel->parms.o_flags;
 800        ((__be16 *)(ipv6h + 1))[1] = (dev->type == ARPHRD_ETHER) ?
 801                                   htons(ETH_P_TEB) : skb->protocol;
 802
 803        if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
 804                __be32 *ptr = (__be32 *)(((u8 *)ipv6h) + tunnel->hlen - 4);
 805
 806                if (tunnel->parms.o_flags&GRE_SEQ) {
 807                        ++tunnel->o_seqno;
 808                        *ptr = htonl(tunnel->o_seqno);
 809                        ptr--;
 810                }
 811                if (tunnel->parms.o_flags&GRE_KEY) {
 812                        *ptr = tunnel->parms.o_key;
 813                        ptr--;
 814                }
 815                if (tunnel->parms.o_flags&GRE_CSUM) {
 816                        *ptr = 0;
 817                        *(__sum16 *)ptr = ip_compute_csum((void *)(ipv6h+1),
 818                                skb->len - sizeof(struct ipv6hdr));
 819                }
 820        }
 821
 822        nf_reset(skb);
 823        pkt_len = skb->len;
 824        err = ip6_local_out(skb);
 825
 826        if (net_xmit_eval(err) == 0) {
 827                struct pcpu_tstats *tstats = this_cpu_ptr(tunnel->dev->tstats);
 828
 829                tstats->tx_bytes += pkt_len;
 830                tstats->tx_packets++;
 831        } else {
 832                stats->tx_errors++;
 833                stats->tx_aborted_errors++;
 834        }
 835
 836        if (ndst)
 837                ip6_tnl_dst_store(tunnel, ndst);
 838
 839        return 0;
 840tx_err_link_failure:
 841        stats->tx_carrier_errors++;
 842        dst_link_failure(skb);
 843tx_err_dst_release:
 844        dst_release(ndst);
 845        return err;
 846}
 847
 848static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 849{
 850        struct ip6_tnl *t = netdev_priv(dev);
 851        const struct iphdr  *iph = ip_hdr(skb);
 852        int encap_limit = -1;
 853        struct flowi6 fl6;
 854        __u8 dsfield;
 855        __u32 mtu;
 856        int err;
 857
 858        if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 859                encap_limit = t->parms.encap_limit;
 860
 861        memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 862        fl6.flowi6_proto = IPPROTO_IPIP;
 863
 864        dsfield = ipv4_get_dsfield(iph);
 865
 866        if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 867                fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
 868                                          & IPV6_TCLASS_MASK;
 869        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 870                fl6.flowi6_mark = skb->mark;
 871
 872        err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 873        if (err != 0) {
 874                /* XXX: send ICMP error even if DF is not set. */
 875                if (err == -EMSGSIZE)
 876                        icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 877                                  htonl(mtu));
 878                return -1;
 879        }
 880
 881        return 0;
 882}
 883
 884static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 885{
 886        struct ip6_tnl *t = netdev_priv(dev);
 887        struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 888        int encap_limit = -1;
 889        __u16 offset;
 890        struct flowi6 fl6;
 891        __u8 dsfield;
 892        __u32 mtu;
 893        int err;
 894
 895        if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
 896                return -1;
 897
 898        offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 899        if (offset > 0) {
 900                struct ipv6_tlv_tnl_enc_lim *tel;
 901                tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 902                if (tel->encap_limit == 0) {
 903                        icmpv6_send(skb, ICMPV6_PARAMPROB,
 904                                    ICMPV6_HDR_FIELD, offset + 2);
 905                        return -1;
 906                }
 907                encap_limit = tel->encap_limit - 1;
 908        } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 909                encap_limit = t->parms.encap_limit;
 910
 911        memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 912        fl6.flowi6_proto = IPPROTO_IPV6;
 913
 914        dsfield = ipv6_get_dsfield(ipv6h);
 915        if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 916                fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
 917        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 918                fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);
 919        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 920                fl6.flowi6_mark = skb->mark;
 921
 922        err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 923        if (err != 0) {
 924                if (err == -EMSGSIZE)
 925                        icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 926                return -1;
 927        }
 928
 929        return 0;
 930}
 931
 932/**
 933 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 934 *   @t: the outgoing tunnel device
 935 *   @hdr: IPv6 header from the incoming packet
 936 *
 937 * Description:
 938 *   Avoid trivial tunneling loop by checking that tunnel exit-point
 939 *   doesn't match source of incoming packet.
 940 *
 941 * Return:
 942 *   1 if conflict,
 943 *   0 else
 944 **/
 945
 946static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
 947        const struct ipv6hdr *hdr)
 948{
 949        return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 950}
 951
 952static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 953{
 954        struct ip6_tnl *t = netdev_priv(dev);
 955        int encap_limit = -1;
 956        struct flowi6 fl6;
 957        __u32 mtu;
 958        int err;
 959
 960        if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 961                encap_limit = t->parms.encap_limit;
 962
 963        memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 964        fl6.flowi6_proto = skb->protocol;
 965
 966        err = ip6gre_xmit2(skb, dev, 0, &fl6, encap_limit, &mtu);
 967
 968        return err;
 969}
 970
 971static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 972        struct net_device *dev)
 973{
 974        struct ip6_tnl *t = netdev_priv(dev);
 975        struct net_device_stats *stats = &t->dev->stats;
 976        int ret;
 977
 978        if (!ip6_tnl_xmit_ctl(t))
 979                return -1;
 980
 981        switch (skb->protocol) {
 982        case htons(ETH_P_IP):
 983                ret = ip6gre_xmit_ipv4(skb, dev);
 984                break;
 985        case htons(ETH_P_IPV6):
 986                ret = ip6gre_xmit_ipv6(skb, dev);
 987                break;
 988        default:
 989                ret = ip6gre_xmit_other(skb, dev);
 990                break;
 991        }
 992
 993        if (ret < 0)
 994                goto tx_err;
 995
 996        return NETDEV_TX_OK;
 997
 998tx_err:
 999        stats->tx_errors++;
1000        stats->tx_dropped++;
1001        kfree_skb(skb);
1002        return NETDEV_TX_OK;
1003}
1004
1005static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
1006{
1007        struct net_device *dev = t->dev;
1008        struct __ip6_tnl_parm *p = &t->parms;
1009        struct flowi6 *fl6 = &t->fl.u.ip6;
1010        int addend = sizeof(struct ipv6hdr) + 4;
1011
1012        if (dev->type != ARPHRD_ETHER) {
1013                memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1014                memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1015        }
1016
1017        /* Set up flowi template */
1018        fl6->saddr = p->laddr;
1019        fl6->daddr = p->raddr;
1020        fl6->flowi6_oif = p->link;
1021        fl6->flowlabel = 0;
1022
1023        if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1024                fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1025        if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1026                fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1027
1028        p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1029        p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1030
1031        if (p->flags&IP6_TNL_F_CAP_XMIT &&
1032                        p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
1033                dev->flags |= IFF_POINTOPOINT;
1034        else
1035                dev->flags &= ~IFF_POINTOPOINT;
1036
1037        dev->iflink = p->link;
1038
1039        /* Precalculate GRE options length */
1040        if (t->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
1041                if (t->parms.o_flags&GRE_CSUM)
1042                        addend += 4;
1043                if (t->parms.o_flags&GRE_KEY)
1044                        addend += 4;
1045                if (t->parms.o_flags&GRE_SEQ)
1046                        addend += 4;
1047        }
1048
1049        if (p->flags & IP6_TNL_F_CAP_XMIT) {
1050                int strict = (ipv6_addr_type(&p->raddr) &
1051                              (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1052
1053                struct rt6_info *rt = rt6_lookup(dev_net(dev),
1054                                                 &p->raddr, &p->laddr,
1055                                                 p->link, strict);
1056
1057                if (rt == NULL)
1058                        return;
1059
1060                if (rt->dst.dev) {
1061                        dev->hard_header_len = rt->dst.dev->hard_header_len + addend;
1062
1063                        if (set_mtu) {
1064                                dev->mtu = rt->dst.dev->mtu - addend;
1065                                if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1066                                        dev->mtu -= 8;
1067
1068                                if (dev->mtu < IPV6_MIN_MTU)
1069                                        dev->mtu = IPV6_MIN_MTU;
1070                        }
1071                }
1072                dst_release(&rt->dst);
1073        }
1074
1075        t->hlen = addend;
1076}
1077
1078static int ip6gre_tnl_change(struct ip6_tnl *t,
1079        const struct __ip6_tnl_parm *p, int set_mtu)
1080{
1081        t->parms.laddr = p->laddr;
1082        t->parms.raddr = p->raddr;
1083        t->parms.flags = p->flags;
1084        t->parms.hop_limit = p->hop_limit;
1085        t->parms.encap_limit = p->encap_limit;
1086        t->parms.flowinfo = p->flowinfo;
1087        t->parms.link = p->link;
1088        t->parms.proto = p->proto;
1089        t->parms.i_key = p->i_key;
1090        t->parms.o_key = p->o_key;
1091        t->parms.i_flags = p->i_flags;
1092        t->parms.o_flags = p->o_flags;
1093        ip6_tnl_dst_reset(t);
1094        ip6gre_tnl_link_config(t, set_mtu);
1095        return 0;
1096}
1097
1098static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1099        const struct ip6_tnl_parm2 *u)
1100{
1101        p->laddr = u->laddr;
1102        p->raddr = u->raddr;
1103        p->flags = u->flags;
1104        p->hop_limit = u->hop_limit;
1105        p->encap_limit = u->encap_limit;
1106        p->flowinfo = u->flowinfo;
1107        p->link = u->link;
1108        p->i_key = u->i_key;
1109        p->o_key = u->o_key;
1110        p->i_flags = u->i_flags;
1111        p->o_flags = u->o_flags;
1112        memcpy(p->name, u->name, sizeof(u->name));
1113}
1114
1115static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1116        const struct __ip6_tnl_parm *p)
1117{
1118        u->proto = IPPROTO_GRE;
1119        u->laddr = p->laddr;
1120        u->raddr = p->raddr;
1121        u->flags = p->flags;
1122        u->hop_limit = p->hop_limit;
1123        u->encap_limit = p->encap_limit;
1124        u->flowinfo = p->flowinfo;
1125        u->link = p->link;
1126        u->i_key = p->i_key;
1127        u->o_key = p->o_key;
1128        u->i_flags = p->i_flags;
1129        u->o_flags = p->o_flags;
1130        memcpy(u->name, p->name, sizeof(u->name));
1131}
1132
1133static int ip6gre_tunnel_ioctl(struct net_device *dev,
1134        struct ifreq *ifr, int cmd)
1135{
1136        int err = 0;
1137        struct ip6_tnl_parm2 p;
1138        struct __ip6_tnl_parm p1;
1139        struct ip6_tnl *t;
1140        struct net *net = dev_net(dev);
1141        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1142
1143        switch (cmd) {
1144        case SIOCGETTUNNEL:
1145                t = NULL;
1146                if (dev == ign->fb_tunnel_dev) {
1147                        if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1148                                err = -EFAULT;
1149                                break;
1150                        }
1151                        ip6gre_tnl_parm_from_user(&p1, &p);
1152                        t = ip6gre_tunnel_locate(net, &p1, 0);
1153                }
1154                if (t == NULL)
1155                        t = netdev_priv(dev);
1156                ip6gre_tnl_parm_to_user(&p, &t->parms);
1157                if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1158                        err = -EFAULT;
1159                break;
1160
1161        case SIOCADDTUNNEL:
1162        case SIOCCHGTUNNEL:
1163                err = -EPERM;
1164                if (!capable(CAP_NET_ADMIN))
1165                        goto done;
1166
1167                err = -EFAULT;
1168                if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1169                        goto done;
1170
1171                err = -EINVAL;
1172                if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1173                        goto done;
1174
1175                if (!(p.i_flags&GRE_KEY))
1176                        p.i_key = 0;
1177                if (!(p.o_flags&GRE_KEY))
1178                        p.o_key = 0;
1179
1180                ip6gre_tnl_parm_from_user(&p1, &p);
1181                t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1182
1183                if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1184                        if (t != NULL) {
1185                                if (t->dev != dev) {
1186                                        err = -EEXIST;
1187                                        break;
1188                                }
1189                        } else {
1190                                t = netdev_priv(dev);
1191
1192                                ip6gre_tunnel_unlink(ign, t);
1193                                synchronize_net();
1194                                ip6gre_tnl_change(t, &p1, 1);
1195                                ip6gre_tunnel_link(ign, t);
1196                                netdev_state_change(dev);
1197                        }
1198                }
1199
1200                if (t) {
1201                        err = 0;
1202
1203                        ip6gre_tnl_parm_to_user(&p, &t->parms);
1204                        if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1205                                err = -EFAULT;
1206                } else
1207                        err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1208                break;
1209
1210        case SIOCDELTUNNEL:
1211                err = -EPERM;
1212                if (!capable(CAP_NET_ADMIN))
1213                        goto done;
1214
1215                if (dev == ign->fb_tunnel_dev) {
1216                        err = -EFAULT;
1217                        if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1218                                goto done;
1219                        err = -ENOENT;
1220                        ip6gre_tnl_parm_from_user(&p1, &p);
1221                        t = ip6gre_tunnel_locate(net, &p1, 0);
1222                        if (t == NULL)
1223                                goto done;
1224                        err = -EPERM;
1225                        if (t == netdev_priv(ign->fb_tunnel_dev))
1226                                goto done;
1227                        dev = t->dev;
1228                }
1229                unregister_netdevice(dev);
1230                err = 0;
1231                break;
1232
1233        default:
1234                err = -EINVAL;
1235        }
1236
1237done:
1238        return err;
1239}
1240
1241static int ip6gre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1242{
1243        struct ip6_tnl *tunnel = netdev_priv(dev);
1244        if (new_mtu < 68 ||
1245            new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
1246                return -EINVAL;
1247        dev->mtu = new_mtu;
1248        return 0;
1249}
1250
1251static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1252                        unsigned short type,
1253                        const void *daddr, const void *saddr, unsigned int len)
1254{
1255        struct ip6_tnl *t = netdev_priv(dev);
1256        struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
1257        __be16 *p = (__be16 *)(ipv6h+1);
1258
1259        *(__be32 *)ipv6h = t->fl.u.ip6.flowlabel | htonl(0x60000000);
1260        ipv6h->hop_limit = t->parms.hop_limit;
1261        ipv6h->nexthdr = NEXTHDR_GRE;
1262        ipv6h->saddr = t->parms.laddr;
1263        ipv6h->daddr = t->parms.raddr;
1264
1265        p[0]            = t->parms.o_flags;
1266        p[1]            = htons(type);
1267
1268        /*
1269         *      Set the source hardware address.
1270         */
1271
1272        if (saddr)
1273                memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1274        if (daddr)
1275                memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1276        if (!ipv6_addr_any(&ipv6h->daddr))
1277                return t->hlen;
1278
1279        return -t->hlen;
1280}
1281
1282static const struct header_ops ip6gre_header_ops = {
1283        .create = ip6gre_header,
1284};
1285
1286static const struct net_device_ops ip6gre_netdev_ops = {
1287        .ndo_init               = ip6gre_tunnel_init,
1288        .ndo_uninit             = ip6gre_tunnel_uninit,
1289        .ndo_start_xmit         = ip6gre_tunnel_xmit,
1290        .ndo_do_ioctl           = ip6gre_tunnel_ioctl,
1291        .ndo_change_mtu         = ip6gre_tunnel_change_mtu,
1292        .ndo_get_stats64        = ip6gre_get_stats64,
1293};
1294
1295static void ip6gre_dev_free(struct net_device *dev)
1296{
1297        free_percpu(dev->tstats);
1298        free_netdev(dev);
1299}
1300
1301static void ip6gre_tunnel_setup(struct net_device *dev)
1302{
1303        struct ip6_tnl *t;
1304
1305        dev->netdev_ops = &ip6gre_netdev_ops;
1306        dev->destructor = ip6gre_dev_free;
1307
1308        dev->type = ARPHRD_IP6GRE;
1309        dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr) + 4;
1310        dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr) - 4;
1311        t = netdev_priv(dev);
1312        if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1313                dev->mtu -= 8;
1314        dev->flags |= IFF_NOARP;
1315        dev->iflink = 0;
1316        dev->addr_len = sizeof(struct in6_addr);
1317        dev->features |= NETIF_F_NETNS_LOCAL;
1318        dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1319}
1320
1321static int ip6gre_tunnel_init(struct net_device *dev)
1322{
1323        struct ip6_tnl *tunnel;
1324
1325        tunnel = netdev_priv(dev);
1326
1327        tunnel->dev = dev;
1328        strcpy(tunnel->parms.name, dev->name);
1329
1330        memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1331        memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1332
1333        if (ipv6_addr_any(&tunnel->parms.raddr))
1334                dev->header_ops = &ip6gre_header_ops;
1335
1336        dev->tstats = alloc_percpu(struct pcpu_tstats);
1337        if (!dev->tstats)
1338                return -ENOMEM;
1339
1340        return 0;
1341}
1342
1343static void ip6gre_fb_tunnel_init(struct net_device *dev)
1344{
1345        struct ip6_tnl *tunnel = netdev_priv(dev);
1346
1347        tunnel->dev = dev;
1348        strcpy(tunnel->parms.name, dev->name);
1349
1350        tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
1351
1352        dev_hold(dev);
1353}
1354
1355
1356static struct inet6_protocol ip6gre_protocol __read_mostly = {
1357        .handler     = ip6gre_rcv,
1358        .err_handler = ip6gre_err,
1359        .flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1360};
1361
1362static void ip6gre_destroy_tunnels(struct ip6gre_net *ign,
1363        struct list_head *head)
1364{
1365        int prio;
1366
1367        for (prio = 0; prio < 4; prio++) {
1368                int h;
1369                for (h = 0; h < HASH_SIZE; h++) {
1370                        struct ip6_tnl *t;
1371
1372                        t = rtnl_dereference(ign->tunnels[prio][h]);
1373
1374                        while (t != NULL) {
1375                                unregister_netdevice_queue(t->dev, head);
1376                                t = rtnl_dereference(t->next);
1377                        }
1378                }
1379        }
1380}
1381
1382static int __net_init ip6gre_init_net(struct net *net)
1383{
1384        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1385        int err;
1386
1387        ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1388                                           ip6gre_tunnel_setup);
1389        if (!ign->fb_tunnel_dev) {
1390                err = -ENOMEM;
1391                goto err_alloc_dev;
1392        }
1393        dev_net_set(ign->fb_tunnel_dev, net);
1394
1395        ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1396        ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1397
1398        err = register_netdev(ign->fb_tunnel_dev);
1399        if (err)
1400                goto err_reg_dev;
1401
1402        rcu_assign_pointer(ign->tunnels_wc[0],
1403                           netdev_priv(ign->fb_tunnel_dev));
1404        return 0;
1405
1406err_reg_dev:
1407        ip6gre_dev_free(ign->fb_tunnel_dev);
1408err_alloc_dev:
1409        return err;
1410}
1411
1412static void __net_exit ip6gre_exit_net(struct net *net)
1413{
1414        struct ip6gre_net *ign;
1415        LIST_HEAD(list);
1416
1417        ign = net_generic(net, ip6gre_net_id);
1418        rtnl_lock();
1419        ip6gre_destroy_tunnels(ign, &list);
1420        unregister_netdevice_many(&list);
1421        rtnl_unlock();
1422}
1423
1424static struct pernet_operations ip6gre_net_ops = {
1425        .init = ip6gre_init_net,
1426        .exit = ip6gre_exit_net,
1427        .id   = &ip6gre_net_id,
1428        .size = sizeof(struct ip6gre_net),
1429};
1430
1431static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1432{
1433        __be16 flags;
1434
1435        if (!data)
1436                return 0;
1437
1438        flags = 0;
1439        if (data[IFLA_GRE_IFLAGS])
1440                flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1441        if (data[IFLA_GRE_OFLAGS])
1442                flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1443        if (flags & (GRE_VERSION|GRE_ROUTING))
1444                return -EINVAL;
1445
1446        return 0;
1447}
1448
1449static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1450{
1451        struct in6_addr daddr;
1452
1453        if (tb[IFLA_ADDRESS]) {
1454                if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1455                        return -EINVAL;
1456                if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1457                        return -EADDRNOTAVAIL;
1458        }
1459
1460        if (!data)
1461                goto out;
1462
1463        if (data[IFLA_GRE_REMOTE]) {
1464                nla_memcpy(&daddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1465                if (ipv6_addr_any(&daddr))
1466                        return -EINVAL;
1467        }
1468
1469out:
1470        return ip6gre_tunnel_validate(tb, data);
1471}
1472
1473
1474static void ip6gre_netlink_parms(struct nlattr *data[],
1475                                struct __ip6_tnl_parm *parms)
1476{
1477        memset(parms, 0, sizeof(*parms));
1478
1479        if (!data)
1480                return;
1481
1482        if (data[IFLA_GRE_LINK])
1483                parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1484
1485        if (data[IFLA_GRE_IFLAGS])
1486                parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1487
1488        if (data[IFLA_GRE_OFLAGS])
1489                parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1490
1491        if (data[IFLA_GRE_IKEY])
1492                parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1493
1494        if (data[IFLA_GRE_OKEY])
1495                parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1496
1497        if (data[IFLA_GRE_LOCAL])
1498                nla_memcpy(&parms->laddr, data[IFLA_GRE_LOCAL], sizeof(struct in6_addr));
1499
1500        if (data[IFLA_GRE_REMOTE])
1501                nla_memcpy(&parms->raddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1502
1503        if (data[IFLA_GRE_TTL])
1504                parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1505
1506        if (data[IFLA_GRE_ENCAP_LIMIT])
1507                parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1508
1509        if (data[IFLA_GRE_FLOWINFO])
1510                parms->flowinfo = nla_get_u32(data[IFLA_GRE_FLOWINFO]);
1511
1512        if (data[IFLA_GRE_FLAGS])
1513                parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1514}
1515
1516static int ip6gre_tap_init(struct net_device *dev)
1517{
1518        struct ip6_tnl *tunnel;
1519
1520        tunnel = netdev_priv(dev);
1521
1522        tunnel->dev = dev;
1523        strcpy(tunnel->parms.name, dev->name);
1524
1525        ip6gre_tnl_link_config(tunnel, 1);
1526
1527        dev->tstats = alloc_percpu(struct pcpu_tstats);
1528        if (!dev->tstats)
1529                return -ENOMEM;
1530
1531        return 0;
1532}
1533
1534static const struct net_device_ops ip6gre_tap_netdev_ops = {
1535        .ndo_init = ip6gre_tap_init,
1536        .ndo_uninit = ip6gre_tunnel_uninit,
1537        .ndo_start_xmit = ip6gre_tunnel_xmit,
1538        .ndo_set_mac_address = eth_mac_addr,
1539        .ndo_validate_addr = eth_validate_addr,
1540        .ndo_change_mtu = ip6gre_tunnel_change_mtu,
1541        .ndo_get_stats64 = ip6gre_get_stats64,
1542};
1543
1544static void ip6gre_tap_setup(struct net_device *dev)
1545{
1546
1547        ether_setup(dev);
1548
1549        dev->netdev_ops = &ip6gre_tap_netdev_ops;
1550        dev->destructor = ip6gre_dev_free;
1551
1552        dev->iflink = 0;
1553        dev->features |= NETIF_F_NETNS_LOCAL;
1554}
1555
1556static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1557        struct nlattr *tb[], struct nlattr *data[])
1558{
1559        struct ip6_tnl *nt;
1560        struct net *net = dev_net(dev);
1561        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1562        int err;
1563
1564        nt = netdev_priv(dev);
1565        ip6gre_netlink_parms(data, &nt->parms);
1566
1567        if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1568                return -EEXIST;
1569
1570        if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1571                eth_hw_addr_random(dev);
1572
1573        nt->dev = dev;
1574        ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1575
1576        /* Can use a lockless transmit, unless we generate output sequences */
1577        if (!(nt->parms.o_flags & GRE_SEQ))
1578                dev->features |= NETIF_F_LLTX;
1579
1580        err = register_netdevice(dev);
1581        if (err)
1582                goto out;
1583
1584        dev_hold(dev);
1585        ip6gre_tunnel_link(ign, nt);
1586
1587out:
1588        return err;
1589}
1590
1591static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1592                            struct nlattr *data[])
1593{
1594        struct ip6_tnl *t, *nt;
1595        struct net *net = dev_net(dev);
1596        struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1597        struct __ip6_tnl_parm p;
1598
1599        if (dev == ign->fb_tunnel_dev)
1600                return -EINVAL;
1601
1602        nt = netdev_priv(dev);
1603        ip6gre_netlink_parms(data, &p);
1604
1605        t = ip6gre_tunnel_locate(net, &p, 0);
1606
1607        if (t) {
1608                if (t->dev != dev)
1609                        return -EEXIST;
1610        } else {
1611                t = nt;
1612
1613                ip6gre_tunnel_unlink(ign, t);
1614                ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1615                ip6gre_tunnel_link(ign, t);
1616                netdev_state_change(dev);
1617        }
1618
1619        return 0;
1620}
1621
1622static size_t ip6gre_get_size(const struct net_device *dev)
1623{
1624        return
1625                /* IFLA_GRE_LINK */
1626                nla_total_size(4) +
1627                /* IFLA_GRE_IFLAGS */
1628                nla_total_size(2) +
1629                /* IFLA_GRE_OFLAGS */
1630                nla_total_size(2) +
1631                /* IFLA_GRE_IKEY */
1632                nla_total_size(4) +
1633                /* IFLA_GRE_OKEY */
1634                nla_total_size(4) +
1635                /* IFLA_GRE_LOCAL */
1636                nla_total_size(sizeof(struct in6_addr)) +
1637                /* IFLA_GRE_REMOTE */
1638                nla_total_size(sizeof(struct in6_addr)) +
1639                /* IFLA_GRE_TTL */
1640                nla_total_size(1) +
1641                /* IFLA_GRE_TOS */
1642                nla_total_size(1) +
1643                /* IFLA_GRE_ENCAP_LIMIT */
1644                nla_total_size(1) +
1645                /* IFLA_GRE_FLOWINFO */
1646                nla_total_size(4) +
1647                /* IFLA_GRE_FLAGS */
1648                nla_total_size(4) +
1649                0;
1650}
1651
1652static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1653{
1654        struct ip6_tnl *t = netdev_priv(dev);
1655        struct __ip6_tnl_parm *p = &t->parms;
1656
1657        if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1658            nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1659            nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1660            nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1661            nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1662            nla_put(skb, IFLA_GRE_LOCAL, sizeof(struct in6_addr), &p->laddr) ||
1663            nla_put(skb, IFLA_GRE_REMOTE, sizeof(struct in6_addr), &p->raddr) ||
1664            nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1665            /*nla_put_u8(skb, IFLA_GRE_TOS, t->priority) ||*/
1666            nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1667            nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1668            nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1669                goto nla_put_failure;
1670        return 0;
1671
1672nla_put_failure:
1673        return -EMSGSIZE;
1674}
1675
1676static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1677        [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1678        [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1679        [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1680        [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1681        [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1682        [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1683        [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1684        [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1685        [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1686        [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1687        [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1688};
1689
1690static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1691        .kind           = "ip6gre",
1692        .maxtype        = IFLA_GRE_MAX,
1693        .policy         = ip6gre_policy,
1694        .priv_size      = sizeof(struct ip6_tnl),
1695        .setup          = ip6gre_tunnel_setup,
1696        .validate       = ip6gre_tunnel_validate,
1697        .newlink        = ip6gre_newlink,
1698        .changelink     = ip6gre_changelink,
1699        .get_size       = ip6gre_get_size,
1700        .fill_info      = ip6gre_fill_info,
1701};
1702
1703static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1704        .kind           = "ip6gretap",
1705        .maxtype        = IFLA_GRE_MAX,
1706        .policy         = ip6gre_policy,
1707        .priv_size      = sizeof(struct ip6_tnl),
1708        .setup          = ip6gre_tap_setup,
1709        .validate       = ip6gre_tap_validate,
1710        .newlink        = ip6gre_newlink,
1711        .changelink     = ip6gre_changelink,
1712        .get_size       = ip6gre_get_size,
1713        .fill_info      = ip6gre_fill_info,
1714};
1715
1716/*
1717 *      And now the modules code and kernel interface.
1718 */
1719
1720static int __init ip6gre_init(void)
1721{
1722        int err;
1723
1724        pr_info("GRE over IPv6 tunneling driver\n");
1725
1726        err = register_pernet_device(&ip6gre_net_ops);
1727        if (err < 0)
1728                return err;
1729
1730        err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1731        if (err < 0) {
1732                pr_info("%s: can't add protocol\n", __func__);
1733                goto add_proto_failed;
1734        }
1735
1736        err = rtnl_link_register(&ip6gre_link_ops);
1737        if (err < 0)
1738                goto rtnl_link_failed;
1739
1740        err = rtnl_link_register(&ip6gre_tap_ops);
1741        if (err < 0)
1742                goto tap_ops_failed;
1743
1744out:
1745        return err;
1746
1747tap_ops_failed:
1748        rtnl_link_unregister(&ip6gre_link_ops);
1749rtnl_link_failed:
1750        inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1751add_proto_failed:
1752        unregister_pernet_device(&ip6gre_net_ops);
1753        goto out;
1754}
1755
1756static void __exit ip6gre_fini(void)
1757{
1758        rtnl_link_unregister(&ip6gre_tap_ops);
1759        rtnl_link_unregister(&ip6gre_link_ops);
1760        inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1761        unregister_pernet_device(&ip6gre_net_ops);
1762}
1763
1764module_init(ip6gre_init);
1765module_exit(ip6gre_fini);
1766MODULE_LICENSE("GPL");
1767MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1768MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1769MODULE_ALIAS_RTNL_LINK("ip6gre");
1770MODULE_ALIAS_NETDEV("ip6gre0");
1771
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