linux/net/ipv6/ip6_tunnel.c
<<
>>
Prefs
   1/*
   2 *      IPv6 tunneling device
   3 *      Linux INET6 implementation
   4 *
   5 *      Authors:
   6 *      Ville Nuorvala          <vnuorval@tcs.hut.fi>
   7 *      Yasuyuki Kozakai        <kozakai@linux-ipv6.org>
   8 *
   9 *      Based on:
  10 *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
  11 *
  12 *      RFC 2473
  13 *
  14 *      This program is free software; you can redistribute it and/or
  15 *      modify it under the terms of the GNU General Public License
  16 *      as published by the Free Software Foundation; either version
  17 *      2 of the License, or (at your option) any later version.
  18 *
  19 */
  20
  21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  22
  23#include <linux/module.h>
  24#include <linux/capability.h>
  25#include <linux/errno.h>
  26#include <linux/types.h>
  27#include <linux/sockios.h>
  28#include <linux/icmp.h>
  29#include <linux/if.h>
  30#include <linux/in.h>
  31#include <linux/ip.h>
  32#include <linux/if_tunnel.h>
  33#include <linux/net.h>
  34#include <linux/in6.h>
  35#include <linux/netdevice.h>
  36#include <linux/if_arp.h>
  37#include <linux/icmpv6.h>
  38#include <linux/init.h>
  39#include <linux/route.h>
  40#include <linux/rtnetlink.h>
  41#include <linux/netfilter_ipv6.h>
  42#include <linux/slab.h>
  43#include <linux/hash.h>
  44
  45#include <asm/uaccess.h>
  46#include <linux/atomic.h>
  47
  48#include <net/icmp.h>
  49#include <net/ip.h>
  50#include <net/ipv6.h>
  51#include <net/ip6_route.h>
  52#include <net/addrconf.h>
  53#include <net/ip6_tunnel.h>
  54#include <net/xfrm.h>
  55#include <net/dsfield.h>
  56#include <net/inet_ecn.h>
  57#include <net/net_namespace.h>
  58#include <net/netns/generic.h>
  59
  60MODULE_AUTHOR("Ville Nuorvala");
  61MODULE_DESCRIPTION("IPv6 tunneling device");
  62MODULE_LICENSE("GPL");
  63MODULE_ALIAS_NETDEV("ip6tnl0");
  64
  65#ifdef IP6_TNL_DEBUG
  66#define IP6_TNL_TRACE(x...) pr_debug("%s:" x "\n", __func__)
  67#else
  68#define IP6_TNL_TRACE(x...) do {;} while(0)
  69#endif
  70
  71#define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
  72#define IPV6_TCLASS_SHIFT 20
  73
  74#define HASH_SIZE_SHIFT  5
  75#define HASH_SIZE (1 << HASH_SIZE_SHIFT)
  76
  77static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
  78{
  79        u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
  80
  81        return hash_32(hash, HASH_SIZE_SHIFT);
  82}
  83
  84static int ip6_tnl_dev_init(struct net_device *dev);
  85static void ip6_tnl_dev_setup(struct net_device *dev);
  86
  87static int ip6_tnl_net_id __read_mostly;
  88struct ip6_tnl_net {
  89        /* the IPv6 tunnel fallback device */
  90        struct net_device *fb_tnl_dev;
  91        /* lists for storing tunnels in use */
  92        struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE];
  93        struct ip6_tnl __rcu *tnls_wc[1];
  94        struct ip6_tnl __rcu **tnls[2];
  95};
  96
  97/* often modified stats are per cpu, other are shared (netdev->stats) */
  98struct pcpu_tstats {
  99        unsigned long   rx_packets;
 100        unsigned long   rx_bytes;
 101        unsigned long   tx_packets;
 102        unsigned long   tx_bytes;
 103} __attribute__((aligned(4*sizeof(unsigned long))));
 104
 105static struct net_device_stats *ip6_get_stats(struct net_device *dev)
 106{
 107        struct pcpu_tstats sum = { 0 };
 108        int i;
 109
 110        for_each_possible_cpu(i) {
 111                const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
 112
 113                sum.rx_packets += tstats->rx_packets;
 114                sum.rx_bytes   += tstats->rx_bytes;
 115                sum.tx_packets += tstats->tx_packets;
 116                sum.tx_bytes   += tstats->tx_bytes;
 117        }
 118        dev->stats.rx_packets = sum.rx_packets;
 119        dev->stats.rx_bytes   = sum.rx_bytes;
 120        dev->stats.tx_packets = sum.tx_packets;
 121        dev->stats.tx_bytes   = sum.tx_bytes;
 122        return &dev->stats;
 123}
 124
 125/*
 126 * Locking : hash tables are protected by RCU and RTNL
 127 */
 128
 129static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
 130{
 131        struct dst_entry *dst = t->dst_cache;
 132
 133        if (dst && dst->obsolete &&
 134            dst->ops->check(dst, t->dst_cookie) == NULL) {
 135                t->dst_cache = NULL;
 136                dst_release(dst);
 137                return NULL;
 138        }
 139
 140        return dst;
 141}
 142
 143static inline void ip6_tnl_dst_reset(struct ip6_tnl *t)
 144{
 145        dst_release(t->dst_cache);
 146        t->dst_cache = NULL;
 147}
 148
 149static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst)
 150{
 151        struct rt6_info *rt = (struct rt6_info *) dst;
 152        t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
 153        dst_release(t->dst_cache);
 154        t->dst_cache = dst;
 155}
 156
 157/**
 158 * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
 159 *   @remote: the address of the tunnel exit-point
 160 *   @local: the address of the tunnel entry-point
 161 *
 162 * Return:
 163 *   tunnel matching given end-points if found,
 164 *   else fallback tunnel if its device is up,
 165 *   else %NULL
 166 **/
 167
 168#define for_each_ip6_tunnel_rcu(start) \
 169        for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
 170
 171static struct ip6_tnl *
 172ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
 173{
 174        unsigned int hash = HASH(remote, local);
 175        struct ip6_tnl *t;
 176        struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 177
 178        for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 179                if (ipv6_addr_equal(local, &t->parms.laddr) &&
 180                    ipv6_addr_equal(remote, &t->parms.raddr) &&
 181                    (t->dev->flags & IFF_UP))
 182                        return t;
 183        }
 184        t = rcu_dereference(ip6n->tnls_wc[0]);
 185        if (t && (t->dev->flags & IFF_UP))
 186                return t;
 187
 188        return NULL;
 189}
 190
 191/**
 192 * ip6_tnl_bucket - get head of list matching given tunnel parameters
 193 *   @p: parameters containing tunnel end-points
 194 *
 195 * Description:
 196 *   ip6_tnl_bucket() returns the head of the list matching the
 197 *   &struct in6_addr entries laddr and raddr in @p.
 198 *
 199 * Return: head of IPv6 tunnel list
 200 **/
 201
 202static struct ip6_tnl __rcu **
 203ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct ip6_tnl_parm *p)
 204{
 205        const struct in6_addr *remote = &p->raddr;
 206        const struct in6_addr *local = &p->laddr;
 207        unsigned int h = 0;
 208        int prio = 0;
 209
 210        if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
 211                prio = 1;
 212                h = HASH(remote, local);
 213        }
 214        return &ip6n->tnls[prio][h];
 215}
 216
 217/**
 218 * ip6_tnl_link - add tunnel to hash table
 219 *   @t: tunnel to be added
 220 **/
 221
 222static void
 223ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 224{
 225        struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
 226
 227        rcu_assign_pointer(t->next , rtnl_dereference(*tp));
 228        rcu_assign_pointer(*tp, t);
 229}
 230
 231/**
 232 * ip6_tnl_unlink - remove tunnel from hash table
 233 *   @t: tunnel to be removed
 234 **/
 235
 236static void
 237ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 238{
 239        struct ip6_tnl __rcu **tp;
 240        struct ip6_tnl *iter;
 241
 242        for (tp = ip6_tnl_bucket(ip6n, &t->parms);
 243             (iter = rtnl_dereference(*tp)) != NULL;
 244             tp = &iter->next) {
 245                if (t == iter) {
 246                        rcu_assign_pointer(*tp, t->next);
 247                        break;
 248                }
 249        }
 250}
 251
 252static void ip6_dev_free(struct net_device *dev)
 253{
 254        free_percpu(dev->tstats);
 255        free_netdev(dev);
 256}
 257
 258/**
 259 * ip6_tnl_create - create a new tunnel
 260 *   @p: tunnel parameters
 261 *   @pt: pointer to new tunnel
 262 *
 263 * Description:
 264 *   Create tunnel matching given parameters.
 265 *
 266 * Return:
 267 *   created tunnel or NULL
 268 **/
 269
 270static struct ip6_tnl *ip6_tnl_create(struct net *net, struct ip6_tnl_parm *p)
 271{
 272        struct net_device *dev;
 273        struct ip6_tnl *t;
 274        char name[IFNAMSIZ];
 275        int err;
 276        struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 277
 278        if (p->name[0])
 279                strlcpy(name, p->name, IFNAMSIZ);
 280        else
 281                sprintf(name, "ip6tnl%%d");
 282
 283        dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup);
 284        if (dev == NULL)
 285                goto failed;
 286
 287        dev_net_set(dev, net);
 288
 289        t = netdev_priv(dev);
 290        t->parms = *p;
 291        err = ip6_tnl_dev_init(dev);
 292        if (err < 0)
 293                goto failed_free;
 294
 295        if ((err = register_netdevice(dev)) < 0)
 296                goto failed_free;
 297
 298        strcpy(t->parms.name, dev->name);
 299
 300        dev_hold(dev);
 301        ip6_tnl_link(ip6n, t);
 302        return t;
 303
 304failed_free:
 305        ip6_dev_free(dev);
 306failed:
 307        return NULL;
 308}
 309
 310/**
 311 * ip6_tnl_locate - find or create tunnel matching given parameters
 312 *   @p: tunnel parameters
 313 *   @create: != 0 if allowed to create new tunnel if no match found
 314 *
 315 * Description:
 316 *   ip6_tnl_locate() first tries to locate an existing tunnel
 317 *   based on @parms. If this is unsuccessful, but @create is set a new
 318 *   tunnel device is created and registered for use.
 319 *
 320 * Return:
 321 *   matching tunnel or NULL
 322 **/
 323
 324static struct ip6_tnl *ip6_tnl_locate(struct net *net,
 325                struct ip6_tnl_parm *p, int create)
 326{
 327        const struct in6_addr *remote = &p->raddr;
 328        const struct in6_addr *local = &p->laddr;
 329        struct ip6_tnl __rcu **tp;
 330        struct ip6_tnl *t;
 331        struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 332
 333        for (tp = ip6_tnl_bucket(ip6n, p);
 334             (t = rtnl_dereference(*tp)) != NULL;
 335             tp = &t->next) {
 336                if (ipv6_addr_equal(local, &t->parms.laddr) &&
 337                    ipv6_addr_equal(remote, &t->parms.raddr))
 338                        return t;
 339        }
 340        if (!create)
 341                return NULL;
 342        return ip6_tnl_create(net, p);
 343}
 344
 345/**
 346 * ip6_tnl_dev_uninit - tunnel device uninitializer
 347 *   @dev: the device to be destroyed
 348 *
 349 * Description:
 350 *   ip6_tnl_dev_uninit() removes tunnel from its list
 351 **/
 352
 353static void
 354ip6_tnl_dev_uninit(struct net_device *dev)
 355{
 356        struct ip6_tnl *t = netdev_priv(dev);
 357        struct net *net = dev_net(dev);
 358        struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 359
 360        if (dev == ip6n->fb_tnl_dev)
 361                RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
 362        else
 363                ip6_tnl_unlink(ip6n, t);
 364        ip6_tnl_dst_reset(t);
 365        dev_put(dev);
 366}
 367
 368/**
 369 * parse_tvl_tnl_enc_lim - handle encapsulation limit option
 370 *   @skb: received socket buffer
 371 *
 372 * Return:
 373 *   0 if none was found,
 374 *   else index to encapsulation limit
 375 **/
 376
 377static __u16
 378parse_tlv_tnl_enc_lim(struct sk_buff *skb, __u8 * raw)
 379{
 380        const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw;
 381        __u8 nexthdr = ipv6h->nexthdr;
 382        __u16 off = sizeof (*ipv6h);
 383
 384        while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
 385                __u16 optlen = 0;
 386                struct ipv6_opt_hdr *hdr;
 387                if (raw + off + sizeof (*hdr) > skb->data &&
 388                    !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
 389                        break;
 390
 391                hdr = (struct ipv6_opt_hdr *) (raw + off);
 392                if (nexthdr == NEXTHDR_FRAGMENT) {
 393                        struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
 394                        if (frag_hdr->frag_off)
 395                                break;
 396                        optlen = 8;
 397                } else if (nexthdr == NEXTHDR_AUTH) {
 398                        optlen = (hdr->hdrlen + 2) << 2;
 399                } else {
 400                        optlen = ipv6_optlen(hdr);
 401                }
 402                if (nexthdr == NEXTHDR_DEST) {
 403                        __u16 i = off + 2;
 404                        while (1) {
 405                                struct ipv6_tlv_tnl_enc_lim *tel;
 406
 407                                /* No more room for encapsulation limit */
 408                                if (i + sizeof (*tel) > off + optlen)
 409                                        break;
 410
 411                                tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
 412                                /* return index of option if found and valid */
 413                                if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
 414                                    tel->length == 1)
 415                                        return i;
 416                                /* else jump to next option */
 417                                if (tel->type)
 418                                        i += tel->length + 2;
 419                                else
 420                                        i++;
 421                        }
 422                }
 423                nexthdr = hdr->nexthdr;
 424                off += optlen;
 425        }
 426        return 0;
 427}
 428
 429/**
 430 * ip6_tnl_err - tunnel error handler
 431 *
 432 * Description:
 433 *   ip6_tnl_err() should handle errors in the tunnel according
 434 *   to the specifications in RFC 2473.
 435 **/
 436
 437static int
 438ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 439            u8 *type, u8 *code, int *msg, __u32 *info, int offset)
 440{
 441        const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
 442        struct ip6_tnl *t;
 443        int rel_msg = 0;
 444        u8 rel_type = ICMPV6_DEST_UNREACH;
 445        u8 rel_code = ICMPV6_ADDR_UNREACH;
 446        __u32 rel_info = 0;
 447        __u16 len;
 448        int err = -ENOENT;
 449
 450        /* If the packet doesn't contain the original IPv6 header we are
 451           in trouble since we might need the source address for further
 452           processing of the error. */
 453
 454        rcu_read_lock();
 455        if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr,
 456                                        &ipv6h->saddr)) == NULL)
 457                goto out;
 458
 459        if (t->parms.proto != ipproto && t->parms.proto != 0)
 460                goto out;
 461
 462        err = 0;
 463
 464        switch (*type) {
 465                __u32 teli;
 466                struct ipv6_tlv_tnl_enc_lim *tel;
 467                __u32 mtu;
 468        case ICMPV6_DEST_UNREACH:
 469                net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
 470                                     t->parms.name);
 471                rel_msg = 1;
 472                break;
 473        case ICMPV6_TIME_EXCEED:
 474                if ((*code) == ICMPV6_EXC_HOPLIMIT) {
 475                        net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 476                                             t->parms.name);
 477                        rel_msg = 1;
 478                }
 479                break;
 480        case ICMPV6_PARAMPROB:
 481                teli = 0;
 482                if ((*code) == ICMPV6_HDR_FIELD)
 483                        teli = parse_tlv_tnl_enc_lim(skb, skb->data);
 484
 485                if (teli && teli == *info - 2) {
 486                        tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 487                        if (tel->encap_limit == 0) {
 488                                net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 489                                                     t->parms.name);
 490                                rel_msg = 1;
 491                        }
 492                } else {
 493                        net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 494                                             t->parms.name);
 495                }
 496                break;
 497        case ICMPV6_PKT_TOOBIG:
 498                mtu = *info - offset;
 499                if (mtu < IPV6_MIN_MTU)
 500                        mtu = IPV6_MIN_MTU;
 501                t->dev->mtu = mtu;
 502
 503                if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) {
 504                        rel_type = ICMPV6_PKT_TOOBIG;
 505                        rel_code = 0;
 506                        rel_info = mtu;
 507                        rel_msg = 1;
 508                }
 509                break;
 510        }
 511
 512        *type = rel_type;
 513        *code = rel_code;
 514        *info = rel_info;
 515        *msg = rel_msg;
 516
 517out:
 518        rcu_read_unlock();
 519        return err;
 520}
 521
 522static int
 523ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 524           u8 type, u8 code, int offset, __be32 info)
 525{
 526        int rel_msg = 0;
 527        u8 rel_type = type;
 528        u8 rel_code = code;
 529        __u32 rel_info = ntohl(info);
 530        int err;
 531        struct sk_buff *skb2;
 532        const struct iphdr *eiph;
 533        struct rtable *rt;
 534        struct flowi4 fl4;
 535
 536        err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
 537                          &rel_msg, &rel_info, offset);
 538        if (err < 0)
 539                return err;
 540
 541        if (rel_msg == 0)
 542                return 0;
 543
 544        switch (rel_type) {
 545        case ICMPV6_DEST_UNREACH:
 546                if (rel_code != ICMPV6_ADDR_UNREACH)
 547                        return 0;
 548                rel_type = ICMP_DEST_UNREACH;
 549                rel_code = ICMP_HOST_UNREACH;
 550                break;
 551        case ICMPV6_PKT_TOOBIG:
 552                if (rel_code != 0)
 553                        return 0;
 554                rel_type = ICMP_DEST_UNREACH;
 555                rel_code = ICMP_FRAG_NEEDED;
 556                break;
 557        case NDISC_REDIRECT:
 558                rel_type = ICMP_REDIRECT;
 559                rel_code = ICMP_REDIR_HOST;
 560        default:
 561                return 0;
 562        }
 563
 564        if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
 565                return 0;
 566
 567        skb2 = skb_clone(skb, GFP_ATOMIC);
 568        if (!skb2)
 569                return 0;
 570
 571        skb_dst_drop(skb2);
 572
 573        skb_pull(skb2, offset);
 574        skb_reset_network_header(skb2);
 575        eiph = ip_hdr(skb2);
 576
 577        /* Try to guess incoming interface */
 578        rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 579                                   eiph->saddr, 0,
 580                                   0, 0,
 581                                   IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 582        if (IS_ERR(rt))
 583                goto out;
 584
 585        skb2->dev = rt->dst.dev;
 586
 587        /* route "incoming" packet */
 588        if (rt->rt_flags & RTCF_LOCAL) {
 589                ip_rt_put(rt);
 590                rt = NULL;
 591                rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 592                                           eiph->daddr, eiph->saddr,
 593                                           0, 0,
 594                                           IPPROTO_IPIP,
 595                                           RT_TOS(eiph->tos), 0);
 596                if (IS_ERR(rt) ||
 597                    rt->dst.dev->type != ARPHRD_TUNNEL) {
 598                        if (!IS_ERR(rt))
 599                                ip_rt_put(rt);
 600                        goto out;
 601                }
 602                skb_dst_set(skb2, &rt->dst);
 603        } else {
 604                ip_rt_put(rt);
 605                if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
 606                                   skb2->dev) ||
 607                    skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
 608                        goto out;
 609        }
 610
 611        /* change mtu on this route */
 612        if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
 613                if (rel_info > dst_mtu(skb_dst(skb2)))
 614                        goto out;
 615
 616                skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info);
 617        }
 618        if (rel_type == ICMP_REDIRECT)
 619                skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2);
 620
 621        icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 622
 623out:
 624        kfree_skb(skb2);
 625        return 0;
 626}
 627
 628static int
 629ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 630           u8 type, u8 code, int offset, __be32 info)
 631{
 632        int rel_msg = 0;
 633        u8 rel_type = type;
 634        u8 rel_code = code;
 635        __u32 rel_info = ntohl(info);
 636        int err;
 637
 638        err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
 639                          &rel_msg, &rel_info, offset);
 640        if (err < 0)
 641                return err;
 642
 643        if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
 644                struct rt6_info *rt;
 645                struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 646
 647                if (!skb2)
 648                        return 0;
 649
 650                skb_dst_drop(skb2);
 651                skb_pull(skb2, offset);
 652                skb_reset_network_header(skb2);
 653
 654                /* Try to guess incoming interface */
 655                rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
 656                                NULL, 0, 0);
 657
 658                if (rt && rt->dst.dev)
 659                        skb2->dev = rt->dst.dev;
 660
 661                icmpv6_send(skb2, rel_type, rel_code, rel_info);
 662
 663                if (rt)
 664                        dst_release(&rt->dst);
 665
 666                kfree_skb(skb2);
 667        }
 668
 669        return 0;
 670}
 671
 672static void ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 673                                        const struct ipv6hdr *ipv6h,
 674                                        struct sk_buff *skb)
 675{
 676        __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
 677
 678        if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 679                ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
 680
 681        if (INET_ECN_is_ce(dsfield))
 682                IP_ECN_set_ce(ip_hdr(skb));
 683}
 684
 685static void ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 686                                        const struct ipv6hdr *ipv6h,
 687                                        struct sk_buff *skb)
 688{
 689        if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 690                ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
 691
 692        if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6h)))
 693                IP6_ECN_set_ce(ipv6_hdr(skb));
 694}
 695
 696static __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
 697                             const struct in6_addr *laddr,
 698                             const struct in6_addr *raddr)
 699{
 700        struct ip6_tnl_parm *p = &t->parms;
 701        int ltype = ipv6_addr_type(laddr);
 702        int rtype = ipv6_addr_type(raddr);
 703        __u32 flags = 0;
 704
 705        if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
 706                flags = IP6_TNL_F_CAP_PER_PACKET;
 707        } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 708                   rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 709                   !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
 710                   (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
 711                if (ltype&IPV6_ADDR_UNICAST)
 712                        flags |= IP6_TNL_F_CAP_XMIT;
 713                if (rtype&IPV6_ADDR_UNICAST)
 714                        flags |= IP6_TNL_F_CAP_RCV;
 715        }
 716        return flags;
 717}
 718
 719/* called with rcu_read_lock() */
 720static inline int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
 721                                  const struct in6_addr *laddr,
 722                                  const struct in6_addr *raddr)
 723{
 724        struct ip6_tnl_parm *p = &t->parms;
 725        int ret = 0;
 726        struct net *net = dev_net(t->dev);
 727
 728        if ((p->flags & IP6_TNL_F_CAP_RCV) ||
 729            ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
 730             (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
 731                struct net_device *ldev = NULL;
 732
 733                if (p->link)
 734                        ldev = dev_get_by_index_rcu(net, p->link);
 735
 736                if ((ipv6_addr_is_multicast(laddr) ||
 737                     likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&
 738                    likely(!ipv6_chk_addr(net, raddr, NULL, 0)))
 739                        ret = 1;
 740        }
 741        return ret;
 742}
 743
 744/**
 745 * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally
 746 *   @skb: received socket buffer
 747 *   @protocol: ethernet protocol ID
 748 *   @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN
 749 *
 750 * Return: 0
 751 **/
 752
 753static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
 754                       __u8 ipproto,
 755                       void (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 756                                                    const struct ipv6hdr *ipv6h,
 757                                                    struct sk_buff *skb))
 758{
 759        struct ip6_tnl *t;
 760        const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 761
 762        rcu_read_lock();
 763
 764        if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr,
 765                                        &ipv6h->daddr)) != NULL) {
 766                struct pcpu_tstats *tstats;
 767
 768                if (t->parms.proto != ipproto && t->parms.proto != 0) {
 769                        rcu_read_unlock();
 770                        goto discard;
 771                }
 772
 773                if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
 774                        rcu_read_unlock();
 775                        goto discard;
 776                }
 777
 778                if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
 779                        t->dev->stats.rx_dropped++;
 780                        rcu_read_unlock();
 781                        goto discard;
 782                }
 783                secpath_reset(skb);
 784                skb->mac_header = skb->network_header;
 785                skb_reset_network_header(skb);
 786                skb->protocol = htons(protocol);
 787                skb->pkt_type = PACKET_HOST;
 788                memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 789
 790                tstats = this_cpu_ptr(t->dev->tstats);
 791                tstats->rx_packets++;
 792                tstats->rx_bytes += skb->len;
 793
 794                __skb_tunnel_rx(skb, t->dev);
 795
 796                dscp_ecn_decapsulate(t, ipv6h, skb);
 797
 798                netif_rx(skb);
 799
 800                rcu_read_unlock();
 801                return 0;
 802        }
 803        rcu_read_unlock();
 804        return 1;
 805
 806discard:
 807        kfree_skb(skb);
 808        return 0;
 809}
 810
 811static int ip4ip6_rcv(struct sk_buff *skb)
 812{
 813        return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP,
 814                           ip4ip6_dscp_ecn_decapsulate);
 815}
 816
 817static int ip6ip6_rcv(struct sk_buff *skb)
 818{
 819        return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6,
 820                           ip6ip6_dscp_ecn_decapsulate);
 821}
 822
 823struct ipv6_tel_txoption {
 824        struct ipv6_txoptions ops;
 825        __u8 dst_opt[8];
 826};
 827
 828static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 829{
 830        memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 831
 832        opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 833        opt->dst_opt[3] = 1;
 834        opt->dst_opt[4] = encap_limit;
 835        opt->dst_opt[5] = IPV6_TLV_PADN;
 836        opt->dst_opt[6] = 1;
 837
 838        opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 839        opt->ops.opt_nflen = 8;
 840}
 841
 842/**
 843 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 844 *   @t: the outgoing tunnel device
 845 *   @hdr: IPv6 header from the incoming packet
 846 *
 847 * Description:
 848 *   Avoid trivial tunneling loop by checking that tunnel exit-point
 849 *   doesn't match source of incoming packet.
 850 *
 851 * Return:
 852 *   1 if conflict,
 853 *   0 else
 854 **/
 855
 856static inline bool
 857ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
 858{
 859        return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 860}
 861
 862static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
 863{
 864        struct ip6_tnl_parm *p = &t->parms;
 865        int ret = 0;
 866        struct net *net = dev_net(t->dev);
 867
 868        if (p->flags & IP6_TNL_F_CAP_XMIT) {
 869                struct net_device *ldev = NULL;
 870
 871                rcu_read_lock();
 872                if (p->link)
 873                        ldev = dev_get_by_index_rcu(net, p->link);
 874
 875                if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0)))
 876                        pr_warn("%s xmit: Local address not yet configured!\n",
 877                                p->name);
 878                else if (!ipv6_addr_is_multicast(&p->raddr) &&
 879                         unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0)))
 880                        pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
 881                                p->name);
 882                else
 883                        ret = 1;
 884                rcu_read_unlock();
 885        }
 886        return ret;
 887}
 888/**
 889 * ip6_tnl_xmit2 - encapsulate packet and send
 890 *   @skb: the outgoing socket buffer
 891 *   @dev: the outgoing tunnel device
 892 *   @dsfield: dscp code for outer header
 893 *   @fl: flow of tunneled packet
 894 *   @encap_limit: encapsulation limit
 895 *   @pmtu: Path MTU is stored if packet is too big
 896 *
 897 * Description:
 898 *   Build new header and do some sanity checks on the packet before sending
 899 *   it.
 900 *
 901 * Return:
 902 *   0 on success
 903 *   -1 fail
 904 *   %-EMSGSIZE message too big. return mtu in this case.
 905 **/
 906
 907static int ip6_tnl_xmit2(struct sk_buff *skb,
 908                         struct net_device *dev,
 909                         __u8 dsfield,
 910                         struct flowi6 *fl6,
 911                         int encap_limit,
 912                         __u32 *pmtu)
 913{
 914        struct net *net = dev_net(dev);
 915        struct ip6_tnl *t = netdev_priv(dev);
 916        struct net_device_stats *stats = &t->dev->stats;
 917        struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 918        struct ipv6_tel_txoption opt;
 919        struct dst_entry *dst = NULL, *ndst = NULL;
 920        struct net_device *tdev;
 921        int mtu;
 922        unsigned int max_headroom = sizeof(struct ipv6hdr);
 923        u8 proto;
 924        int err = -1;
 925        int pkt_len;
 926
 927        if (!fl6->flowi6_mark)
 928                dst = ip6_tnl_dst_check(t);
 929        if (!dst) {
 930                ndst = ip6_route_output(net, NULL, fl6);
 931
 932                if (ndst->error)
 933                        goto tx_err_link_failure;
 934                ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
 935                if (IS_ERR(ndst)) {
 936                        err = PTR_ERR(ndst);
 937                        ndst = NULL;
 938                        goto tx_err_link_failure;
 939                }
 940                dst = ndst;
 941        }
 942
 943        tdev = dst->dev;
 944
 945        if (tdev == dev) {
 946                stats->collisions++;
 947                net_warn_ratelimited("%s: Local routing loop detected!\n",
 948                                     t->parms.name);
 949                goto tx_err_dst_release;
 950        }
 951        mtu = dst_mtu(dst) - sizeof (*ipv6h);
 952        if (encap_limit >= 0) {
 953                max_headroom += 8;
 954                mtu -= 8;
 955        }
 956        if (mtu < IPV6_MIN_MTU)
 957                mtu = IPV6_MIN_MTU;
 958        if (skb_dst(skb))
 959                skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 960        if (skb->len > mtu) {
 961                *pmtu = mtu;
 962                err = -EMSGSIZE;
 963                goto tx_err_dst_release;
 964        }
 965
 966        /*
 967         * Okay, now see if we can stuff it in the buffer as-is.
 968         */
 969        max_headroom += LL_RESERVED_SPACE(tdev);
 970
 971        if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 972            (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 973                struct sk_buff *new_skb;
 974
 975                if (!(new_skb = skb_realloc_headroom(skb, max_headroom)))
 976                        goto tx_err_dst_release;
 977
 978                if (skb->sk)
 979                        skb_set_owner_w(new_skb, skb->sk);
 980                consume_skb(skb);
 981                skb = new_skb;
 982        }
 983        skb_dst_drop(skb);
 984        if (fl6->flowi6_mark) {
 985                skb_dst_set(skb, dst);
 986                ndst = NULL;
 987        } else {
 988                skb_dst_set_noref(skb, dst);
 989        }
 990        skb->transport_header = skb->network_header;
 991
 992        proto = fl6->flowi6_proto;
 993        if (encap_limit >= 0) {
 994                init_tel_txopt(&opt, encap_limit);
 995                ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
 996        }
 997        skb_push(skb, sizeof(struct ipv6hdr));
 998        skb_reset_network_header(skb);
 999        ipv6h = ipv6_hdr(skb);
1000        *(__be32*)ipv6h = fl6->flowlabel | htonl(0x60000000);
1001        dsfield = INET_ECN_encapsulate(0, dsfield);
1002        ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield);
1003        ipv6h->hop_limit = t->parms.hop_limit;
1004        ipv6h->nexthdr = proto;
1005        ipv6h->saddr = fl6->saddr;
1006        ipv6h->daddr = fl6->daddr;
1007        nf_reset(skb);
1008        pkt_len = skb->len;
1009        err = ip6_local_out(skb);
1010
1011        if (net_xmit_eval(err) == 0) {
1012                struct pcpu_tstats *tstats = this_cpu_ptr(t->dev->tstats);
1013
1014                tstats->tx_bytes += pkt_len;
1015                tstats->tx_packets++;
1016        } else {
1017                stats->tx_errors++;
1018                stats->tx_aborted_errors++;
1019        }
1020        if (ndst)
1021                ip6_tnl_dst_store(t, ndst);
1022        return 0;
1023tx_err_link_failure:
1024        stats->tx_carrier_errors++;
1025        dst_link_failure(skb);
1026tx_err_dst_release:
1027        dst_release(ndst);
1028        return err;
1029}
1030
1031static inline int
1032ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1033{
1034        struct ip6_tnl *t = netdev_priv(dev);
1035        const struct iphdr  *iph = ip_hdr(skb);
1036        int encap_limit = -1;
1037        struct flowi6 fl6;
1038        __u8 dsfield;
1039        __u32 mtu;
1040        int err;
1041
1042        if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) ||
1043            !ip6_tnl_xmit_ctl(t))
1044                return -1;
1045
1046        if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1047                encap_limit = t->parms.encap_limit;
1048
1049        memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6));
1050        fl6.flowi6_proto = IPPROTO_IPIP;
1051
1052        dsfield = ipv4_get_dsfield(iph);
1053
1054        if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1055                fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
1056                                          & IPV6_TCLASS_MASK;
1057        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1058                fl6.flowi6_mark = skb->mark;
1059
1060        err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1061        if (err != 0) {
1062                /* XXX: send ICMP error even if DF is not set. */
1063                if (err == -EMSGSIZE)
1064                        icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1065                                  htonl(mtu));
1066                return -1;
1067        }
1068
1069        return 0;
1070}
1071
1072static inline int
1073ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1074{
1075        struct ip6_tnl *t = netdev_priv(dev);
1076        struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1077        int encap_limit = -1;
1078        __u16 offset;
1079        struct flowi6 fl6;
1080        __u8 dsfield;
1081        __u32 mtu;
1082        int err;
1083
1084        if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
1085            !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h))
1086                return -1;
1087
1088        offset = parse_tlv_tnl_enc_lim(skb, skb_network_header(skb));
1089        if (offset > 0) {
1090                struct ipv6_tlv_tnl_enc_lim *tel;
1091                tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
1092                if (tel->encap_limit == 0) {
1093                        icmpv6_send(skb, ICMPV6_PARAMPROB,
1094                                    ICMPV6_HDR_FIELD, offset + 2);
1095                        return -1;
1096                }
1097                encap_limit = tel->encap_limit - 1;
1098        } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1099                encap_limit = t->parms.encap_limit;
1100
1101        memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6));
1102        fl6.flowi6_proto = IPPROTO_IPV6;
1103
1104        dsfield = ipv6_get_dsfield(ipv6h);
1105        if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1106                fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
1107        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1108                fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);
1109        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1110                fl6.flowi6_mark = skb->mark;
1111
1112        err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1113        if (err != 0) {
1114                if (err == -EMSGSIZE)
1115                        icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1116                return -1;
1117        }
1118
1119        return 0;
1120}
1121
1122static netdev_tx_t
1123ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1124{
1125        struct ip6_tnl *t = netdev_priv(dev);
1126        struct net_device_stats *stats = &t->dev->stats;
1127        int ret;
1128
1129        switch (skb->protocol) {
1130        case htons(ETH_P_IP):
1131                ret = ip4ip6_tnl_xmit(skb, dev);
1132                break;
1133        case htons(ETH_P_IPV6):
1134                ret = ip6ip6_tnl_xmit(skb, dev);
1135                break;
1136        default:
1137                goto tx_err;
1138        }
1139
1140        if (ret < 0)
1141                goto tx_err;
1142
1143        return NETDEV_TX_OK;
1144
1145tx_err:
1146        stats->tx_errors++;
1147        stats->tx_dropped++;
1148        kfree_skb(skb);
1149        return NETDEV_TX_OK;
1150}
1151
1152static void ip6_tnl_link_config(struct ip6_tnl *t)
1153{
1154        struct net_device *dev = t->dev;
1155        struct ip6_tnl_parm *p = &t->parms;
1156        struct flowi6 *fl6 = &t->fl.u.ip6;
1157
1158        memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1159        memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1160
1161        /* Set up flowi template */
1162        fl6->saddr = p->laddr;
1163        fl6->daddr = p->raddr;
1164        fl6->flowi6_oif = p->link;
1165        fl6->flowlabel = 0;
1166
1167        if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1168                fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1169        if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1170                fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1171
1172        p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1173        p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1174
1175        if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1176                dev->flags |= IFF_POINTOPOINT;
1177        else
1178                dev->flags &= ~IFF_POINTOPOINT;
1179
1180        dev->iflink = p->link;
1181
1182        if (p->flags & IP6_TNL_F_CAP_XMIT) {
1183                int strict = (ipv6_addr_type(&p->raddr) &
1184                              (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1185
1186                struct rt6_info *rt = rt6_lookup(dev_net(dev),
1187                                                 &p->raddr, &p->laddr,
1188                                                 p->link, strict);
1189
1190                if (rt == NULL)
1191                        return;
1192
1193                if (rt->dst.dev) {
1194                        dev->hard_header_len = rt->dst.dev->hard_header_len +
1195                                sizeof (struct ipv6hdr);
1196
1197                        dev->mtu = rt->dst.dev->mtu - sizeof (struct ipv6hdr);
1198                        if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1199                                dev->mtu-=8;
1200
1201                        if (dev->mtu < IPV6_MIN_MTU)
1202                                dev->mtu = IPV6_MIN_MTU;
1203                }
1204                dst_release(&rt->dst);
1205        }
1206}
1207
1208/**
1209 * ip6_tnl_change - update the tunnel parameters
1210 *   @t: tunnel to be changed
1211 *   @p: tunnel configuration parameters
1212 *
1213 * Description:
1214 *   ip6_tnl_change() updates the tunnel parameters
1215 **/
1216
1217static int
1218ip6_tnl_change(struct ip6_tnl *t, struct ip6_tnl_parm *p)
1219{
1220        t->parms.laddr = p->laddr;
1221        t->parms.raddr = p->raddr;
1222        t->parms.flags = p->flags;
1223        t->parms.hop_limit = p->hop_limit;
1224        t->parms.encap_limit = p->encap_limit;
1225        t->parms.flowinfo = p->flowinfo;
1226        t->parms.link = p->link;
1227        t->parms.proto = p->proto;
1228        ip6_tnl_dst_reset(t);
1229        ip6_tnl_link_config(t);
1230        return 0;
1231}
1232
1233/**
1234 * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1235 *   @dev: virtual device associated with tunnel
1236 *   @ifr: parameters passed from userspace
1237 *   @cmd: command to be performed
1238 *
1239 * Description:
1240 *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1241 *   from userspace.
1242 *
1243 *   The possible commands are the following:
1244 *     %SIOCGETTUNNEL: get tunnel parameters for device
1245 *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1246 *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1247 *     %SIOCDELTUNNEL: delete tunnel
1248 *
1249 *   The fallback device "ip6tnl0", created during module
1250 *   initialization, can be used for creating other tunnel devices.
1251 *
1252 * Return:
1253 *   0 on success,
1254 *   %-EFAULT if unable to copy data to or from userspace,
1255 *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1256 *   %-EINVAL if passed tunnel parameters are invalid,
1257 *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1258 *   %-ENODEV if attempting to change or delete a nonexisting device
1259 **/
1260
1261static int
1262ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1263{
1264        int err = 0;
1265        struct ip6_tnl_parm p;
1266        struct ip6_tnl *t = NULL;
1267        struct net *net = dev_net(dev);
1268        struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1269
1270        switch (cmd) {
1271        case SIOCGETTUNNEL:
1272                if (dev == ip6n->fb_tnl_dev) {
1273                        if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) {
1274                                err = -EFAULT;
1275                                break;
1276                        }
1277                        t = ip6_tnl_locate(net, &p, 0);
1278                }
1279                if (t == NULL)
1280                        t = netdev_priv(dev);
1281                memcpy(&p, &t->parms, sizeof (p));
1282                if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) {
1283                        err = -EFAULT;
1284                }
1285                break;
1286        case SIOCADDTUNNEL:
1287        case SIOCCHGTUNNEL:
1288                err = -EPERM;
1289                if (!capable(CAP_NET_ADMIN))
1290                        break;
1291                err = -EFAULT;
1292                if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1293                        break;
1294                err = -EINVAL;
1295                if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1296                    p.proto != 0)
1297                        break;
1298                t = ip6_tnl_locate(net, &p, cmd == SIOCADDTUNNEL);
1299                if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
1300                        if (t != NULL) {
1301                                if (t->dev != dev) {
1302                                        err = -EEXIST;
1303                                        break;
1304                                }
1305                        } else
1306                                t = netdev_priv(dev);
1307
1308                        ip6_tnl_unlink(ip6n, t);
1309                        synchronize_net();
1310                        err = ip6_tnl_change(t, &p);
1311                        ip6_tnl_link(ip6n, t);
1312                        netdev_state_change(dev);
1313                }
1314                if (t) {
1315                        err = 0;
1316                        if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof (p)))
1317                                err = -EFAULT;
1318
1319                } else
1320                        err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1321                break;
1322        case SIOCDELTUNNEL:
1323                err = -EPERM;
1324                if (!capable(CAP_NET_ADMIN))
1325                        break;
1326
1327                if (dev == ip6n->fb_tnl_dev) {
1328                        err = -EFAULT;
1329                        if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1330                                break;
1331                        err = -ENOENT;
1332                        if ((t = ip6_tnl_locate(net, &p, 0)) == NULL)
1333                                break;
1334                        err = -EPERM;
1335                        if (t->dev == ip6n->fb_tnl_dev)
1336                                break;
1337                        dev = t->dev;
1338                }
1339                err = 0;
1340                unregister_netdevice(dev);
1341                break;
1342        default:
1343                err = -EINVAL;
1344        }
1345        return err;
1346}
1347
1348/**
1349 * ip6_tnl_change_mtu - change mtu manually for tunnel device
1350 *   @dev: virtual device associated with tunnel
1351 *   @new_mtu: the new mtu
1352 *
1353 * Return:
1354 *   0 on success,
1355 *   %-EINVAL if mtu too small
1356 **/
1357
1358static int
1359ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1360{
1361        if (new_mtu < IPV6_MIN_MTU) {
1362                return -EINVAL;
1363        }
1364        dev->mtu = new_mtu;
1365        return 0;
1366}
1367
1368
1369static const struct net_device_ops ip6_tnl_netdev_ops = {
1370        .ndo_uninit     = ip6_tnl_dev_uninit,
1371        .ndo_start_xmit = ip6_tnl_xmit,
1372        .ndo_do_ioctl   = ip6_tnl_ioctl,
1373        .ndo_change_mtu = ip6_tnl_change_mtu,
1374        .ndo_get_stats  = ip6_get_stats,
1375};
1376
1377
1378/**
1379 * ip6_tnl_dev_setup - setup virtual tunnel device
1380 *   @dev: virtual device associated with tunnel
1381 *
1382 * Description:
1383 *   Initialize function pointers and device parameters
1384 **/
1385
1386static void ip6_tnl_dev_setup(struct net_device *dev)
1387{
1388        struct ip6_tnl *t;
1389
1390        dev->netdev_ops = &ip6_tnl_netdev_ops;
1391        dev->destructor = ip6_dev_free;
1392
1393        dev->type = ARPHRD_TUNNEL6;
1394        dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr);
1395        dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr);
1396        t = netdev_priv(dev);
1397        if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1398                dev->mtu-=8;
1399        dev->flags |= IFF_NOARP;
1400        dev->addr_len = sizeof(struct in6_addr);
1401        dev->features |= NETIF_F_NETNS_LOCAL;
1402        dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1403}
1404
1405
1406/**
1407 * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1408 *   @dev: virtual device associated with tunnel
1409 **/
1410
1411static inline int
1412ip6_tnl_dev_init_gen(struct net_device *dev)
1413{
1414        struct ip6_tnl *t = netdev_priv(dev);
1415
1416        t->dev = dev;
1417        dev->tstats = alloc_percpu(struct pcpu_tstats);
1418        if (!dev->tstats)
1419                return -ENOMEM;
1420        return 0;
1421}
1422
1423/**
1424 * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1425 *   @dev: virtual device associated with tunnel
1426 **/
1427
1428static int ip6_tnl_dev_init(struct net_device *dev)
1429{
1430        struct ip6_tnl *t = netdev_priv(dev);
1431        int err = ip6_tnl_dev_init_gen(dev);
1432
1433        if (err)
1434                return err;
1435        ip6_tnl_link_config(t);
1436        return 0;
1437}
1438
1439/**
1440 * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1441 *   @dev: fallback device
1442 *
1443 * Return: 0
1444 **/
1445
1446static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1447{
1448        struct ip6_tnl *t = netdev_priv(dev);
1449        struct net *net = dev_net(dev);
1450        struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1451        int err = ip6_tnl_dev_init_gen(dev);
1452
1453        if (err)
1454                return err;
1455
1456        t->parms.proto = IPPROTO_IPV6;
1457        dev_hold(dev);
1458
1459        ip6_tnl_link_config(t);
1460
1461        rcu_assign_pointer(ip6n->tnls_wc[0], t);
1462        return 0;
1463}
1464
1465static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
1466        .handler        = ip4ip6_rcv,
1467        .err_handler    = ip4ip6_err,
1468        .priority       =       1,
1469};
1470
1471static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
1472        .handler        = ip6ip6_rcv,
1473        .err_handler    = ip6ip6_err,
1474        .priority       =       1,
1475};
1476
1477static void __net_exit ip6_tnl_destroy_tunnels(struct ip6_tnl_net *ip6n)
1478{
1479        int h;
1480        struct ip6_tnl *t;
1481        LIST_HEAD(list);
1482
1483        for (h = 0; h < HASH_SIZE; h++) {
1484                t = rtnl_dereference(ip6n->tnls_r_l[h]);
1485                while (t != NULL) {
1486                        unregister_netdevice_queue(t->dev, &list);
1487                        t = rtnl_dereference(t->next);
1488                }
1489        }
1490
1491        t = rtnl_dereference(ip6n->tnls_wc[0]);
1492        unregister_netdevice_queue(t->dev, &list);
1493        unregister_netdevice_many(&list);
1494}
1495
1496static int __net_init ip6_tnl_init_net(struct net *net)
1497{
1498        struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1499        struct ip6_tnl *t = NULL;
1500        int err;
1501
1502        ip6n->tnls[0] = ip6n->tnls_wc;
1503        ip6n->tnls[1] = ip6n->tnls_r_l;
1504
1505        err = -ENOMEM;
1506        ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
1507                                      ip6_tnl_dev_setup);
1508
1509        if (!ip6n->fb_tnl_dev)
1510                goto err_alloc_dev;
1511        dev_net_set(ip6n->fb_tnl_dev, net);
1512
1513        err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
1514        if (err < 0)
1515                goto err_register;
1516
1517        err = register_netdev(ip6n->fb_tnl_dev);
1518        if (err < 0)
1519                goto err_register;
1520
1521        t = netdev_priv(ip6n->fb_tnl_dev);
1522
1523        strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
1524        return 0;
1525
1526err_register:
1527        ip6_dev_free(ip6n->fb_tnl_dev);
1528err_alloc_dev:
1529        return err;
1530}
1531
1532static void __net_exit ip6_tnl_exit_net(struct net *net)
1533{
1534        struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1535
1536        rtnl_lock();
1537        ip6_tnl_destroy_tunnels(ip6n);
1538        rtnl_unlock();
1539}
1540
1541static struct pernet_operations ip6_tnl_net_ops = {
1542        .init = ip6_tnl_init_net,
1543        .exit = ip6_tnl_exit_net,
1544        .id   = &ip6_tnl_net_id,
1545        .size = sizeof(struct ip6_tnl_net),
1546};
1547
1548/**
1549 * ip6_tunnel_init - register protocol and reserve needed resources
1550 *
1551 * Return: 0 on success
1552 **/
1553
1554static int __init ip6_tunnel_init(void)
1555{
1556        int  err;
1557
1558        err = register_pernet_device(&ip6_tnl_net_ops);
1559        if (err < 0)
1560                goto out_pernet;
1561
1562        err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
1563        if (err < 0) {
1564                pr_err("%s: can't register ip4ip6\n", __func__);
1565                goto out_ip4ip6;
1566        }
1567
1568        err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
1569        if (err < 0) {
1570                pr_err("%s: can't register ip6ip6\n", __func__);
1571                goto out_ip6ip6;
1572        }
1573
1574        return 0;
1575
1576out_ip6ip6:
1577        xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
1578out_ip4ip6:
1579        unregister_pernet_device(&ip6_tnl_net_ops);
1580out_pernet:
1581        return err;
1582}
1583
1584/**
1585 * ip6_tunnel_cleanup - free resources and unregister protocol
1586 **/
1587
1588static void __exit ip6_tunnel_cleanup(void)
1589{
1590        if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
1591                pr_info("%s: can't deregister ip4ip6\n", __func__);
1592
1593        if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
1594                pr_info("%s: can't deregister ip6ip6\n", __func__);
1595
1596        unregister_pernet_device(&ip6_tnl_net_ops);
1597}
1598
1599module_init(ip6_tunnel_init);
1600module_exit(ip6_tunnel_cleanup);
1601
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.