linux/net/xfrm/xfrm_policy.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * xfrm_policy.c
   4 *
   5 * Changes:
   6 *      Mitsuru KANDA @USAGI
   7 *      Kazunori MIYAZAWA @USAGI
   8 *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
   9 *              IPv6 support
  10 *      Kazunori MIYAZAWA @USAGI
  11 *      YOSHIFUJI Hideaki
  12 *              Split up af-specific portion
  13 *      Derek Atkins <derek@ihtfp.com>          Add the post_input processor
  14 *
  15 */
  16
  17#include <linux/err.h>
  18#include <linux/slab.h>
  19#include <linux/kmod.h>
  20#include <linux/list.h>
  21#include <linux/spinlock.h>
  22#include <linux/workqueue.h>
  23#include <linux/notifier.h>
  24#include <linux/netdevice.h>
  25#include <linux/netfilter.h>
  26#include <linux/module.h>
  27#include <linux/cache.h>
  28#include <linux/cpu.h>
  29#include <linux/audit.h>
  30#include <linux/rhashtable.h>
  31#include <linux/if_tunnel.h>
  32#include <net/dst.h>
  33#include <net/flow.h>
  34#include <net/xfrm.h>
  35#include <net/ip.h>
  36#if IS_ENABLED(CONFIG_IPV6_MIP6)
  37#include <net/mip6.h>
  38#endif
  39#ifdef CONFIG_XFRM_STATISTICS
  40#include <net/snmp.h>
  41#endif
  42#ifdef CONFIG_XFRM_ESPINTCP
  43#include <net/espintcp.h>
  44#endif
  45
  46#include "xfrm_hash.h"
  47
  48#define XFRM_QUEUE_TMO_MIN ((unsigned)(HZ/10))
  49#define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ))
  50#define XFRM_MAX_QUEUE_LEN      100
  51
  52struct xfrm_flo {
  53        struct dst_entry *dst_orig;
  54        u8 flags;
  55};
  56
  57/* prefixes smaller than this are stored in lists, not trees. */
  58#define INEXACT_PREFIXLEN_IPV4  16
  59#define INEXACT_PREFIXLEN_IPV6  48
  60
  61struct xfrm_pol_inexact_node {
  62        struct rb_node node;
  63        union {
  64                xfrm_address_t addr;
  65                struct rcu_head rcu;
  66        };
  67        u8 prefixlen;
  68
  69        struct rb_root root;
  70
  71        /* the policies matching this node, can be empty list */
  72        struct hlist_head hhead;
  73};
  74
  75/* xfrm inexact policy search tree:
  76 * xfrm_pol_inexact_bin = hash(dir,type,family,if_id);
  77 *  |
  78 * +---- root_d: sorted by daddr:prefix
  79 * |                 |
  80 * |        xfrm_pol_inexact_node
  81 * |                 |
  82 * |                 +- root: sorted by saddr/prefix
  83 * |                 |              |
  84 * |                 |         xfrm_pol_inexact_node
  85 * |                 |              |
  86 * |                 |              + root: unused
  87 * |                 |              |
  88 * |                 |              + hhead: saddr:daddr policies
  89 * |                 |
  90 * |                 +- coarse policies and all any:daddr policies
  91 * |
  92 * +---- root_s: sorted by saddr:prefix
  93 * |                 |
  94 * |        xfrm_pol_inexact_node
  95 * |                 |
  96 * |                 + root: unused
  97 * |                 |
  98 * |                 + hhead: saddr:any policies
  99 * |
 100 * +---- coarse policies and all any:any policies
 101 *
 102 * Lookups return four candidate lists:
 103 * 1. any:any list from top-level xfrm_pol_inexact_bin
 104 * 2. any:daddr list from daddr tree
 105 * 3. saddr:daddr list from 2nd level daddr tree
 106 * 4. saddr:any list from saddr tree
 107 *
 108 * This result set then needs to be searched for the policy with
 109 * the lowest priority.  If two results have same prio, youngest one wins.
 110 */
 111
 112struct xfrm_pol_inexact_key {
 113        possible_net_t net;
 114        u32 if_id;
 115        u16 family;
 116        u8 dir, type;
 117};
 118
 119struct xfrm_pol_inexact_bin {
 120        struct xfrm_pol_inexact_key k;
 121        struct rhash_head head;
 122        /* list containing '*:*' policies */
 123        struct hlist_head hhead;
 124
 125        seqcount_spinlock_t count;
 126        /* tree sorted by daddr/prefix */
 127        struct rb_root root_d;
 128
 129        /* tree sorted by saddr/prefix */
 130        struct rb_root root_s;
 131
 132        /* slow path below */
 133        struct list_head inexact_bins;
 134        struct rcu_head rcu;
 135};
 136
 137enum xfrm_pol_inexact_candidate_type {
 138        XFRM_POL_CAND_BOTH,
 139        XFRM_POL_CAND_SADDR,
 140        XFRM_POL_CAND_DADDR,
 141        XFRM_POL_CAND_ANY,
 142
 143        XFRM_POL_CAND_MAX,
 144};
 145
 146struct xfrm_pol_inexact_candidates {
 147        struct hlist_head *res[XFRM_POL_CAND_MAX];
 148};
 149
 150static DEFINE_SPINLOCK(xfrm_if_cb_lock);
 151static struct xfrm_if_cb const __rcu *xfrm_if_cb __read_mostly;
 152
 153static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
 154static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1]
 155                                                __read_mostly;
 156
 157static struct kmem_cache *xfrm_dst_cache __ro_after_init;
 158static __read_mostly seqcount_mutex_t xfrm_policy_hash_generation;
 159
 160static struct rhashtable xfrm_policy_inexact_table;
 161static const struct rhashtable_params xfrm_pol_inexact_params;
 162
 163static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr);
 164static int stale_bundle(struct dst_entry *dst);
 165static int xfrm_bundle_ok(struct xfrm_dst *xdst);
 166static void xfrm_policy_queue_process(struct timer_list *t);
 167
 168static void __xfrm_policy_link(struct xfrm_policy *pol, int dir);
 169static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
 170                                                int dir);
 171
 172static struct xfrm_pol_inexact_bin *
 173xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family, u8 dir,
 174                           u32 if_id);
 175
 176static struct xfrm_pol_inexact_bin *
 177xfrm_policy_inexact_lookup_rcu(struct net *net,
 178                               u8 type, u16 family, u8 dir, u32 if_id);
 179static struct xfrm_policy *
 180xfrm_policy_insert_list(struct hlist_head *chain, struct xfrm_policy *policy,
 181                        bool excl);
 182static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
 183                                            struct xfrm_policy *policy);
 184
 185static bool
 186xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
 187                                    struct xfrm_pol_inexact_bin *b,
 188                                    const xfrm_address_t *saddr,
 189                                    const xfrm_address_t *daddr);
 190
 191static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy)
 192{
 193        return refcount_inc_not_zero(&policy->refcnt);
 194}
 195
 196static inline bool
 197__xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
 198{
 199        const struct flowi4 *fl4 = &fl->u.ip4;
 200
 201        return  addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
 202                addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
 203                !((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
 204                !((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
 205                (fl4->flowi4_proto == sel->proto || !sel->proto) &&
 206                (fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
 207}
 208
 209static inline bool
 210__xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
 211{
 212        const struct flowi6 *fl6 = &fl->u.ip6;
 213
 214        return  addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
 215                addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
 216                !((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
 217                !((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
 218                (fl6->flowi6_proto == sel->proto || !sel->proto) &&
 219                (fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
 220}
 221
 222bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
 223                         unsigned short family)
 224{
 225        switch (family) {
 226        case AF_INET:
 227                return __xfrm4_selector_match(sel, fl);
 228        case AF_INET6:
 229                return __xfrm6_selector_match(sel, fl);
 230        }
 231        return false;
 232}
 233
 234static const struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
 235{
 236        const struct xfrm_policy_afinfo *afinfo;
 237
 238        if (unlikely(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
 239                return NULL;
 240        rcu_read_lock();
 241        afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
 242        if (unlikely(!afinfo))
 243                rcu_read_unlock();
 244        return afinfo;
 245}
 246
 247/* Called with rcu_read_lock(). */
 248static const struct xfrm_if_cb *xfrm_if_get_cb(void)
 249{
 250        return rcu_dereference(xfrm_if_cb);
 251}
 252
 253struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos, int oif,
 254                                    const xfrm_address_t *saddr,
 255                                    const xfrm_address_t *daddr,
 256                                    int family, u32 mark)
 257{
 258        const struct xfrm_policy_afinfo *afinfo;
 259        struct dst_entry *dst;
 260
 261        afinfo = xfrm_policy_get_afinfo(family);
 262        if (unlikely(afinfo == NULL))
 263                return ERR_PTR(-EAFNOSUPPORT);
 264
 265        dst = afinfo->dst_lookup(net, tos, oif, saddr, daddr, mark);
 266
 267        rcu_read_unlock();
 268
 269        return dst;
 270}
 271EXPORT_SYMBOL(__xfrm_dst_lookup);
 272
 273static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x,
 274                                                int tos, int oif,
 275                                                xfrm_address_t *prev_saddr,
 276                                                xfrm_address_t *prev_daddr,
 277                                                int family, u32 mark)
 278{
 279        struct net *net = xs_net(x);
 280        xfrm_address_t *saddr = &x->props.saddr;
 281        xfrm_address_t *daddr = &x->id.daddr;
 282        struct dst_entry *dst;
 283
 284        if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
 285                saddr = x->coaddr;
 286                daddr = prev_daddr;
 287        }
 288        if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
 289                saddr = prev_saddr;
 290                daddr = x->coaddr;
 291        }
 292
 293        dst = __xfrm_dst_lookup(net, tos, oif, saddr, daddr, family, mark);
 294
 295        if (!IS_ERR(dst)) {
 296                if (prev_saddr != saddr)
 297                        memcpy(prev_saddr, saddr,  sizeof(*prev_saddr));
 298                if (prev_daddr != daddr)
 299                        memcpy(prev_daddr, daddr,  sizeof(*prev_daddr));
 300        }
 301
 302        return dst;
 303}
 304
 305static inline unsigned long make_jiffies(long secs)
 306{
 307        if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
 308                return MAX_SCHEDULE_TIMEOUT-1;
 309        else
 310                return secs*HZ;
 311}
 312
 313static void xfrm_policy_timer(struct timer_list *t)
 314{
 315        struct xfrm_policy *xp = from_timer(xp, t, timer);
 316        time64_t now = ktime_get_real_seconds();
 317        time64_t next = TIME64_MAX;
 318        int warn = 0;
 319        int dir;
 320
 321        read_lock(&xp->lock);
 322
 323        if (unlikely(xp->walk.dead))
 324                goto out;
 325
 326        dir = xfrm_policy_id2dir(xp->index);
 327
 328        if (xp->lft.hard_add_expires_seconds) {
 329                time64_t tmo = xp->lft.hard_add_expires_seconds +
 330                        xp->curlft.add_time - now;
 331                if (tmo <= 0)
 332                        goto expired;
 333                if (tmo < next)
 334                        next = tmo;
 335        }
 336        if (xp->lft.hard_use_expires_seconds) {
 337                time64_t tmo = xp->lft.hard_use_expires_seconds +
 338                        (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 339                if (tmo <= 0)
 340                        goto expired;
 341                if (tmo < next)
 342                        next = tmo;
 343        }
 344        if (xp->lft.soft_add_expires_seconds) {
 345                time64_t tmo = xp->lft.soft_add_expires_seconds +
 346                        xp->curlft.add_time - now;
 347                if (tmo <= 0) {
 348                        warn = 1;
 349                        tmo = XFRM_KM_TIMEOUT;
 350                }
 351                if (tmo < next)
 352                        next = tmo;
 353        }
 354        if (xp->lft.soft_use_expires_seconds) {
 355                time64_t tmo = xp->lft.soft_use_expires_seconds +
 356                        (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 357                if (tmo <= 0) {
 358                        warn = 1;
 359                        tmo = XFRM_KM_TIMEOUT;
 360                }
 361                if (tmo < next)
 362                        next = tmo;
 363        }
 364
 365        if (warn)
 366                km_policy_expired(xp, dir, 0, 0);
 367        if (next != TIME64_MAX &&
 368            !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
 369                xfrm_pol_hold(xp);
 370
 371out:
 372        read_unlock(&xp->lock);
 373        xfrm_pol_put(xp);
 374        return;
 375
 376expired:
 377        read_unlock(&xp->lock);
 378        if (!xfrm_policy_delete(xp, dir))
 379                km_policy_expired(xp, dir, 1, 0);
 380        xfrm_pol_put(xp);
 381}
 382
 383/* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
 384 * SPD calls.
 385 */
 386
 387struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
 388{
 389        struct xfrm_policy *policy;
 390
 391        policy = kzalloc(sizeof(struct xfrm_policy), gfp);
 392
 393        if (policy) {
 394                write_pnet(&policy->xp_net, net);
 395                INIT_LIST_HEAD(&policy->walk.all);
 396                INIT_HLIST_NODE(&policy->bydst_inexact_list);
 397                INIT_HLIST_NODE(&policy->bydst);
 398                INIT_HLIST_NODE(&policy->byidx);
 399                rwlock_init(&policy->lock);
 400                refcount_set(&policy->refcnt, 1);
 401                skb_queue_head_init(&policy->polq.hold_queue);
 402                timer_setup(&policy->timer, xfrm_policy_timer, 0);
 403                timer_setup(&policy->polq.hold_timer,
 404                            xfrm_policy_queue_process, 0);
 405        }
 406        return policy;
 407}
 408EXPORT_SYMBOL(xfrm_policy_alloc);
 409
 410static void xfrm_policy_destroy_rcu(struct rcu_head *head)
 411{
 412        struct xfrm_policy *policy = container_of(head, struct xfrm_policy, rcu);
 413
 414        security_xfrm_policy_free(policy->security);
 415        kfree(policy);
 416}
 417
 418/* Destroy xfrm_policy: descendant resources must be released to this moment. */
 419
 420void xfrm_policy_destroy(struct xfrm_policy *policy)
 421{
 422        BUG_ON(!policy->walk.dead);
 423
 424        if (del_timer(&policy->timer) || del_timer(&policy->polq.hold_timer))
 425                BUG();
 426
 427        call_rcu(&policy->rcu, xfrm_policy_destroy_rcu);
 428}
 429EXPORT_SYMBOL(xfrm_policy_destroy);
 430
 431/* Rule must be locked. Release descendant resources, announce
 432 * entry dead. The rule must be unlinked from lists to the moment.
 433 */
 434
 435static void xfrm_policy_kill(struct xfrm_policy *policy)
 436{
 437        write_lock_bh(&policy->lock);
 438        policy->walk.dead = 1;
 439        write_unlock_bh(&policy->lock);
 440
 441        atomic_inc(&policy->genid);
 442
 443        if (del_timer(&policy->polq.hold_timer))
 444                xfrm_pol_put(policy);
 445        skb_queue_purge(&policy->polq.hold_queue);
 446
 447        if (del_timer(&policy->timer))
 448                xfrm_pol_put(policy);
 449
 450        xfrm_pol_put(policy);
 451}
 452
 453static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
 454
 455static inline unsigned int idx_hash(struct net *net, u32 index)
 456{
 457        return __idx_hash(index, net->xfrm.policy_idx_hmask);
 458}
 459
 460/* calculate policy hash thresholds */
 461static void __get_hash_thresh(struct net *net,
 462                              unsigned short family, int dir,
 463                              u8 *dbits, u8 *sbits)
 464{
 465        switch (family) {
 466        case AF_INET:
 467                *dbits = net->xfrm.policy_bydst[dir].dbits4;
 468                *sbits = net->xfrm.policy_bydst[dir].sbits4;
 469                break;
 470
 471        case AF_INET6:
 472                *dbits = net->xfrm.policy_bydst[dir].dbits6;
 473                *sbits = net->xfrm.policy_bydst[dir].sbits6;
 474                break;
 475
 476        default:
 477                *dbits = 0;
 478                *sbits = 0;
 479        }
 480}
 481
 482static struct hlist_head *policy_hash_bysel(struct net *net,
 483                                            const struct xfrm_selector *sel,
 484                                            unsigned short family, int dir)
 485{
 486        unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 487        unsigned int hash;
 488        u8 dbits;
 489        u8 sbits;
 490
 491        __get_hash_thresh(net, family, dir, &dbits, &sbits);
 492        hash = __sel_hash(sel, family, hmask, dbits, sbits);
 493
 494        if (hash == hmask + 1)
 495                return NULL;
 496
 497        return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
 498                     lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
 499}
 500
 501static struct hlist_head *policy_hash_direct(struct net *net,
 502                                             const xfrm_address_t *daddr,
 503                                             const xfrm_address_t *saddr,
 504                                             unsigned short family, int dir)
 505{
 506        unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 507        unsigned int hash;
 508        u8 dbits;
 509        u8 sbits;
 510
 511        __get_hash_thresh(net, family, dir, &dbits, &sbits);
 512        hash = __addr_hash(daddr, saddr, family, hmask, dbits, sbits);
 513
 514        return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
 515                     lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
 516}
 517
 518static void xfrm_dst_hash_transfer(struct net *net,
 519                                   struct hlist_head *list,
 520                                   struct hlist_head *ndsttable,
 521                                   unsigned int nhashmask,
 522                                   int dir)
 523{
 524        struct hlist_node *tmp, *entry0 = NULL;
 525        struct xfrm_policy *pol;
 526        unsigned int h0 = 0;
 527        u8 dbits;
 528        u8 sbits;
 529
 530redo:
 531        hlist_for_each_entry_safe(pol, tmp, list, bydst) {
 532                unsigned int h;
 533
 534                __get_hash_thresh(net, pol->family, dir, &dbits, &sbits);
 535                h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
 536                                pol->family, nhashmask, dbits, sbits);
 537                if (!entry0) {
 538                        hlist_del_rcu(&pol->bydst);
 539                        hlist_add_head_rcu(&pol->bydst, ndsttable + h);
 540                        h0 = h;
 541                } else {
 542                        if (h != h0)
 543                                continue;
 544                        hlist_del_rcu(&pol->bydst);
 545                        hlist_add_behind_rcu(&pol->bydst, entry0);
 546                }
 547                entry0 = &pol->bydst;
 548        }
 549        if (!hlist_empty(list)) {
 550                entry0 = NULL;
 551                goto redo;
 552        }
 553}
 554
 555static void xfrm_idx_hash_transfer(struct hlist_head *list,
 556                                   struct hlist_head *nidxtable,
 557                                   unsigned int nhashmask)
 558{
 559        struct hlist_node *tmp;
 560        struct xfrm_policy *pol;
 561
 562        hlist_for_each_entry_safe(pol, tmp, list, byidx) {
 563                unsigned int h;
 564
 565                h = __idx_hash(pol->index, nhashmask);
 566                hlist_add_head(&pol->byidx, nidxtable+h);
 567        }
 568}
 569
 570static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
 571{
 572        return ((old_hmask + 1) << 1) - 1;
 573}
 574
 575static void xfrm_bydst_resize(struct net *net, int dir)
 576{
 577        unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 578        unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 579        unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 580        struct hlist_head *ndst = xfrm_hash_alloc(nsize);
 581        struct hlist_head *odst;
 582        int i;
 583
 584        if (!ndst)
 585                return;
 586
 587        spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 588        write_seqcount_begin(&xfrm_policy_hash_generation);
 589
 590        odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
 591                                lockdep_is_held(&net->xfrm.xfrm_policy_lock));
 592
 593        for (i = hmask; i >= 0; i--)
 594                xfrm_dst_hash_transfer(net, odst + i, ndst, nhashmask, dir);
 595
 596        rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst);
 597        net->xfrm.policy_bydst[dir].hmask = nhashmask;
 598
 599        write_seqcount_end(&xfrm_policy_hash_generation);
 600        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 601
 602        synchronize_rcu();
 603
 604        xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
 605}
 606
 607static void xfrm_byidx_resize(struct net *net, int total)
 608{
 609        unsigned int hmask = net->xfrm.policy_idx_hmask;
 610        unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 611        unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 612        struct hlist_head *oidx = net->xfrm.policy_byidx;
 613        struct hlist_head *nidx = xfrm_hash_alloc(nsize);
 614        int i;
 615
 616        if (!nidx)
 617                return;
 618
 619        spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 620
 621        for (i = hmask; i >= 0; i--)
 622                xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
 623
 624        net->xfrm.policy_byidx = nidx;
 625        net->xfrm.policy_idx_hmask = nhashmask;
 626
 627        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 628
 629        xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
 630}
 631
 632static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
 633{
 634        unsigned int cnt = net->xfrm.policy_count[dir];
 635        unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 636
 637        if (total)
 638                *total += cnt;
 639
 640        if ((hmask + 1) < xfrm_policy_hashmax &&
 641            cnt > hmask)
 642                return 1;
 643
 644        return 0;
 645}
 646
 647static inline int xfrm_byidx_should_resize(struct net *net, int total)
 648{
 649        unsigned int hmask = net->xfrm.policy_idx_hmask;
 650
 651        if ((hmask + 1) < xfrm_policy_hashmax &&
 652            total > hmask)
 653                return 1;
 654
 655        return 0;
 656}
 657
 658void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
 659{
 660        si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
 661        si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
 662        si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
 663        si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
 664        si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
 665        si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
 666        si->spdhcnt = net->xfrm.policy_idx_hmask;
 667        si->spdhmcnt = xfrm_policy_hashmax;
 668}
 669EXPORT_SYMBOL(xfrm_spd_getinfo);
 670
 671static DEFINE_MUTEX(hash_resize_mutex);
 672static void xfrm_hash_resize(struct work_struct *work)
 673{
 674        struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
 675        int dir, total;
 676
 677        mutex_lock(&hash_resize_mutex);
 678
 679        total = 0;
 680        for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 681                if (xfrm_bydst_should_resize(net, dir, &total))
 682                        xfrm_bydst_resize(net, dir);
 683        }
 684        if (xfrm_byidx_should_resize(net, total))
 685                xfrm_byidx_resize(net, total);
 686
 687        mutex_unlock(&hash_resize_mutex);
 688}
 689
 690/* Make sure *pol can be inserted into fastbin.
 691 * Useful to check that later insert requests will be sucessful
 692 * (provided xfrm_policy_lock is held throughout).
 693 */
 694static struct xfrm_pol_inexact_bin *
 695xfrm_policy_inexact_alloc_bin(const struct xfrm_policy *pol, u8 dir)
 696{
 697        struct xfrm_pol_inexact_bin *bin, *prev;
 698        struct xfrm_pol_inexact_key k = {
 699                .family = pol->family,
 700                .type = pol->type,
 701                .dir = dir,
 702                .if_id = pol->if_id,
 703        };
 704        struct net *net = xp_net(pol);
 705
 706        lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
 707
 708        write_pnet(&k.net, net);
 709        bin = rhashtable_lookup_fast(&xfrm_policy_inexact_table, &k,
 710                                     xfrm_pol_inexact_params);
 711        if (bin)
 712                return bin;
 713
 714        bin = kzalloc(sizeof(*bin), GFP_ATOMIC);
 715        if (!bin)
 716                return NULL;
 717
 718        bin->k = k;
 719        INIT_HLIST_HEAD(&bin->hhead);
 720        bin->root_d = RB_ROOT;
 721        bin->root_s = RB_ROOT;
 722        seqcount_spinlock_init(&bin->count, &net->xfrm.xfrm_policy_lock);
 723
 724        prev = rhashtable_lookup_get_insert_key(&xfrm_policy_inexact_table,
 725                                                &bin->k, &bin->head,
 726                                                xfrm_pol_inexact_params);
 727        if (!prev) {
 728                list_add(&bin->inexact_bins, &net->xfrm.inexact_bins);
 729                return bin;
 730        }
 731
 732        kfree(bin);
 733
 734        return IS_ERR(prev) ? NULL : prev;
 735}
 736
 737static bool xfrm_pol_inexact_addr_use_any_list(const xfrm_address_t *addr,
 738                                               int family, u8 prefixlen)
 739{
 740        if (xfrm_addr_any(addr, family))
 741                return true;
 742
 743        if (family == AF_INET6 && prefixlen < INEXACT_PREFIXLEN_IPV6)
 744                return true;
 745
 746        if (family == AF_INET && prefixlen < INEXACT_PREFIXLEN_IPV4)
 747                return true;
 748
 749        return false;
 750}
 751
 752static bool
 753xfrm_policy_inexact_insert_use_any_list(const struct xfrm_policy *policy)
 754{
 755        const xfrm_address_t *addr;
 756        bool saddr_any, daddr_any;
 757        u8 prefixlen;
 758
 759        addr = &policy->selector.saddr;
 760        prefixlen = policy->selector.prefixlen_s;
 761
 762        saddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
 763                                                       policy->family,
 764                                                       prefixlen);
 765        addr = &policy->selector.daddr;
 766        prefixlen = policy->selector.prefixlen_d;
 767        daddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
 768                                                       policy->family,
 769                                                       prefixlen);
 770        return saddr_any && daddr_any;
 771}
 772
 773static void xfrm_pol_inexact_node_init(struct xfrm_pol_inexact_node *node,
 774                                       const xfrm_address_t *addr, u8 prefixlen)
 775{
 776        node->addr = *addr;
 777        node->prefixlen = prefixlen;
 778}
 779
 780static struct xfrm_pol_inexact_node *
 781xfrm_pol_inexact_node_alloc(const xfrm_address_t *addr, u8 prefixlen)
 782{
 783        struct xfrm_pol_inexact_node *node;
 784
 785        node = kzalloc(sizeof(*node), GFP_ATOMIC);
 786        if (node)
 787                xfrm_pol_inexact_node_init(node, addr, prefixlen);
 788
 789        return node;
 790}
 791
 792static int xfrm_policy_addr_delta(const xfrm_address_t *a,
 793                                  const xfrm_address_t *b,
 794                                  u8 prefixlen, u16 family)
 795{
 796        unsigned int pdw, pbi;
 797        int delta = 0;
 798
 799        switch (family) {
 800        case AF_INET:
 801                if (sizeof(long) == 4 && prefixlen == 0)
 802                        return ntohl(a->a4) - ntohl(b->a4);
 803                return (ntohl(a->a4) & ((~0UL << (32 - prefixlen)))) -
 804                       (ntohl(b->a4) & ((~0UL << (32 - prefixlen))));
 805        case AF_INET6:
 806                pdw = prefixlen >> 5;
 807                pbi = prefixlen & 0x1f;
 808
 809                if (pdw) {
 810                        delta = memcmp(a->a6, b->a6, pdw << 2);
 811                        if (delta)
 812                                return delta;
 813                }
 814                if (pbi) {
 815                        u32 mask = ~0u << (32 - pbi);
 816
 817                        delta = (ntohl(a->a6[pdw]) & mask) -
 818                                (ntohl(b->a6[pdw]) & mask);
 819                }
 820                break;
 821        default:
 822                break;
 823        }
 824
 825        return delta;
 826}
 827
 828static void xfrm_policy_inexact_list_reinsert(struct net *net,
 829                                              struct xfrm_pol_inexact_node *n,
 830                                              u16 family)
 831{
 832        unsigned int matched_s, matched_d;
 833        struct xfrm_policy *policy, *p;
 834
 835        matched_s = 0;
 836        matched_d = 0;
 837
 838        list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
 839                struct hlist_node *newpos = NULL;
 840                bool matches_s, matches_d;
 841
 842                if (!policy->bydst_reinsert)
 843                        continue;
 844
 845                WARN_ON_ONCE(policy->family != family);
 846
 847                policy->bydst_reinsert = false;
 848                hlist_for_each_entry(p, &n->hhead, bydst) {
 849                        if (policy->priority > p->priority)
 850                                newpos = &p->bydst;
 851                        else if (policy->priority == p->priority &&
 852                                 policy->pos > p->pos)
 853                                newpos = &p->bydst;
 854                        else
 855                                break;
 856                }
 857
 858                if (newpos)
 859                        hlist_add_behind_rcu(&policy->bydst, newpos);
 860                else
 861                        hlist_add_head_rcu(&policy->bydst, &n->hhead);
 862
 863                /* paranoia checks follow.
 864                 * Check that the reinserted policy matches at least
 865                 * saddr or daddr for current node prefix.
 866                 *
 867                 * Matching both is fine, matching saddr in one policy
 868                 * (but not daddr) and then matching only daddr in another
 869                 * is a bug.
 870                 */
 871                matches_s = xfrm_policy_addr_delta(&policy->selector.saddr,
 872                                                   &n->addr,
 873                                                   n->prefixlen,
 874                                                   family) == 0;
 875                matches_d = xfrm_policy_addr_delta(&policy->selector.daddr,
 876                                                   &n->addr,
 877                                                   n->prefixlen,
 878                                                   family) == 0;
 879                if (matches_s && matches_d)
 880                        continue;
 881
 882                WARN_ON_ONCE(!matches_s && !matches_d);
 883                if (matches_s)
 884                        matched_s++;
 885                if (matches_d)
 886                        matched_d++;
 887                WARN_ON_ONCE(matched_s && matched_d);
 888        }
 889}
 890
 891static void xfrm_policy_inexact_node_reinsert(struct net *net,
 892                                              struct xfrm_pol_inexact_node *n,
 893                                              struct rb_root *new,
 894                                              u16 family)
 895{
 896        struct xfrm_pol_inexact_node *node;
 897        struct rb_node **p, *parent;
 898
 899        /* we should not have another subtree here */
 900        WARN_ON_ONCE(!RB_EMPTY_ROOT(&n->root));
 901restart:
 902        parent = NULL;
 903        p = &new->rb_node;
 904        while (*p) {
 905                u8 prefixlen;
 906                int delta;
 907
 908                parent = *p;
 909                node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
 910
 911                prefixlen = min(node->prefixlen, n->prefixlen);
 912
 913                delta = xfrm_policy_addr_delta(&n->addr, &node->addr,
 914                                               prefixlen, family);
 915                if (delta < 0) {
 916                        p = &parent->rb_left;
 917                } else if (delta > 0) {
 918                        p = &parent->rb_right;
 919                } else {
 920                        bool same_prefixlen = node->prefixlen == n->prefixlen;
 921                        struct xfrm_policy *tmp;
 922
 923                        hlist_for_each_entry(tmp, &n->hhead, bydst) {
 924                                tmp->bydst_reinsert = true;
 925                                hlist_del_rcu(&tmp->bydst);
 926                        }
 927
 928                        node->prefixlen = prefixlen;
 929
 930                        xfrm_policy_inexact_list_reinsert(net, node, family);
 931
 932                        if (same_prefixlen) {
 933                                kfree_rcu(n, rcu);
 934                                return;
 935                        }
 936
 937                        rb_erase(*p, new);
 938                        kfree_rcu(n, rcu);
 939                        n = node;
 940                        goto restart;
 941                }
 942        }
 943
 944        rb_link_node_rcu(&n->node, parent, p);
 945        rb_insert_color(&n->node, new);
 946}
 947
 948/* merge nodes v and n */
 949static void xfrm_policy_inexact_node_merge(struct net *net,
 950                                           struct xfrm_pol_inexact_node *v,
 951                                           struct xfrm_pol_inexact_node *n,
 952                                           u16 family)
 953{
 954        struct xfrm_pol_inexact_node *node;
 955        struct xfrm_policy *tmp;
 956        struct rb_node *rnode;
 957
 958        /* To-be-merged node v has a subtree.
 959         *
 960         * Dismantle it and insert its nodes to n->root.
 961         */
 962        while ((rnode = rb_first(&v->root)) != NULL) {
 963                node = rb_entry(rnode, struct xfrm_pol_inexact_node, node);
 964                rb_erase(&node->node, &v->root);
 965                xfrm_policy_inexact_node_reinsert(net, node, &n->root,
 966                                                  family);
 967        }
 968
 969        hlist_for_each_entry(tmp, &v->hhead, bydst) {
 970                tmp->bydst_reinsert = true;
 971                hlist_del_rcu(&tmp->bydst);
 972        }
 973
 974        xfrm_policy_inexact_list_reinsert(net, n, family);
 975}
 976
 977static struct xfrm_pol_inexact_node *
 978xfrm_policy_inexact_insert_node(struct net *net,
 979                                struct rb_root *root,
 980                                xfrm_address_t *addr,
 981                                u16 family, u8 prefixlen, u8 dir)
 982{
 983        struct xfrm_pol_inexact_node *cached = NULL;
 984        struct rb_node **p, *parent = NULL;
 985        struct xfrm_pol_inexact_node *node;
 986
 987        p = &root->rb_node;
 988        while (*p) {
 989                int delta;
 990
 991                parent = *p;
 992                node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
 993
 994                delta = xfrm_policy_addr_delta(addr, &node->addr,
 995                                               node->prefixlen,
 996                                               family);
 997                if (delta == 0 && prefixlen >= node->prefixlen) {
 998                        WARN_ON_ONCE(cached); /* ipsec policies got lost */
 999                        return node;
1000                }
1001
1002                if (delta < 0)
1003                        p = &parent->rb_left;
1004                else
1005                        p = &parent->rb_right;
1006
1007                if (prefixlen < node->prefixlen) {
1008                        delta = xfrm_policy_addr_delta(addr, &node->addr,
1009                                                       prefixlen,
1010                                                       family);
1011                        if (delta)
1012                                continue;
1013
1014                        /* This node is a subnet of the new prefix. It needs
1015                         * to be removed and re-inserted with the smaller
1016                         * prefix and all nodes that are now also covered
1017                         * by the reduced prefixlen.
1018                         */
1019                        rb_erase(&node->node, root);
1020
1021                        if (!cached) {
1022                                xfrm_pol_inexact_node_init(node, addr,
1023                                                           prefixlen);
1024                                cached = node;
1025                        } else {
1026                                /* This node also falls within the new
1027                                 * prefixlen. Merge the to-be-reinserted
1028                                 * node and this one.
1029                                 */
1030                                xfrm_policy_inexact_node_merge(net, node,
1031                                                               cached, family);
1032                                kfree_rcu(node, rcu);
1033                        }
1034
1035                        /* restart */
1036                        p = &root->rb_node;
1037                        parent = NULL;
1038                }
1039        }
1040
1041        node = cached;
1042        if (!node) {
1043                node = xfrm_pol_inexact_node_alloc(addr, prefixlen);
1044                if (!node)
1045                        return NULL;
1046        }
1047
1048        rb_link_node_rcu(&node->node, parent, p);
1049        rb_insert_color(&node->node, root);
1050
1051        return node;
1052}
1053
1054static void xfrm_policy_inexact_gc_tree(struct rb_root *r, bool rm)
1055{
1056        struct xfrm_pol_inexact_node *node;
1057        struct rb_node *rn = rb_first(r);
1058
1059        while (rn) {
1060                node = rb_entry(rn, struct xfrm_pol_inexact_node, node);
1061
1062                xfrm_policy_inexact_gc_tree(&node->root, rm);
1063                rn = rb_next(rn);
1064
1065                if (!hlist_empty(&node->hhead) || !RB_EMPTY_ROOT(&node->root)) {
1066                        WARN_ON_ONCE(rm);
1067                        continue;
1068                }
1069
1070                rb_erase(&node->node, r);
1071                kfree_rcu(node, rcu);
1072        }
1073}
1074
1075static void __xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b, bool net_exit)
1076{
1077        write_seqcount_begin(&b->count);
1078        xfrm_policy_inexact_gc_tree(&b->root_d, net_exit);
1079        xfrm_policy_inexact_gc_tree(&b->root_s, net_exit);
1080        write_seqcount_end(&b->count);
1081
1082        if (!RB_EMPTY_ROOT(&b->root_d) || !RB_EMPTY_ROOT(&b->root_s) ||
1083            !hlist_empty(&b->hhead)) {
1084                WARN_ON_ONCE(net_exit);
1085                return;
1086        }
1087
1088        if (rhashtable_remove_fast(&xfrm_policy_inexact_table, &b->head,
1089                                   xfrm_pol_inexact_params) == 0) {
1090                list_del(&b->inexact_bins);
1091                kfree_rcu(b, rcu);
1092        }
1093}
1094
1095static void xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b)
1096{
1097        struct net *net = read_pnet(&b->k.net);
1098
1099        spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1100        __xfrm_policy_inexact_prune_bin(b, false);
1101        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1102}
1103
1104static void __xfrm_policy_inexact_flush(struct net *net)
1105{
1106        struct xfrm_pol_inexact_bin *bin, *t;
1107
1108        lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1109
1110        list_for_each_entry_safe(bin, t, &net->xfrm.inexact_bins, inexact_bins)
1111                __xfrm_policy_inexact_prune_bin(bin, false);
1112}
1113
1114static struct hlist_head *
1115xfrm_policy_inexact_alloc_chain(struct xfrm_pol_inexact_bin *bin,
1116                                struct xfrm_policy *policy, u8 dir)
1117{
1118        struct xfrm_pol_inexact_node *n;
1119        struct net *net;
1120
1121        net = xp_net(policy);
1122        lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1123
1124        if (xfrm_policy_inexact_insert_use_any_list(policy))
1125                return &bin->hhead;
1126
1127        if (xfrm_pol_inexact_addr_use_any_list(&policy->selector.daddr,
1128                                               policy->family,
1129                                               policy->selector.prefixlen_d)) {
1130                write_seqcount_begin(&bin->count);
1131                n = xfrm_policy_inexact_insert_node(net,
1132                                                    &bin->root_s,
1133                                                    &policy->selector.saddr,
1134                                                    policy->family,
1135                                                    policy->selector.prefixlen_s,
1136                                                    dir);
1137                write_seqcount_end(&bin->count);
1138                if (!n)
1139                        return NULL;
1140
1141                return &n->hhead;
1142        }
1143
1144        /* daddr is fixed */
1145        write_seqcount_begin(&bin->count);
1146        n = xfrm_policy_inexact_insert_node(net,
1147                                            &bin->root_d,
1148                                            &policy->selector.daddr,
1149                                            policy->family,
1150                                            policy->selector.prefixlen_d, dir);
1151        write_seqcount_end(&bin->count);
1152        if (!n)
1153                return NULL;
1154
1155        /* saddr is wildcard */
1156        if (xfrm_pol_inexact_addr_use_any_list(&policy->selector.saddr,
1157                                               policy->family,
1158                                               policy->selector.prefixlen_s))
1159                return &n->hhead;
1160
1161        write_seqcount_begin(&bin->count);
1162        n = xfrm_policy_inexact_insert_node(net,
1163                                            &n->root,
1164                                            &policy->selector.saddr,
1165                                            policy->family,
1166                                            policy->selector.prefixlen_s, dir);
1167        write_seqcount_end(&bin->count);
1168        if (!n)
1169                return NULL;
1170
1171        return &n->hhead;
1172}
1173
1174static struct xfrm_policy *
1175xfrm_policy_inexact_insert(struct xfrm_policy *policy, u8 dir, int excl)
1176{
1177        struct xfrm_pol_inexact_bin *bin;
1178        struct xfrm_policy *delpol;
1179        struct hlist_head *chain;
1180        struct net *net;
1181
1182        bin = xfrm_policy_inexact_alloc_bin(policy, dir);
1183        if (!bin)
1184                return ERR_PTR(-ENOMEM);
1185
1186        net = xp_net(policy);
1187        lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1188
1189        chain = xfrm_policy_inexact_alloc_chain(bin, policy, dir);
1190        if (!chain) {
1191                __xfrm_policy_inexact_prune_bin(bin, false);
1192                return ERR_PTR(-ENOMEM);
1193        }
1194
1195        delpol = xfrm_policy_insert_list(chain, policy, excl);
1196        if (delpol && excl) {
1197                __xfrm_policy_inexact_prune_bin(bin, false);
1198                return ERR_PTR(-EEXIST);
1199        }
1200
1201        chain = &net->xfrm.policy_inexact[dir];
1202        xfrm_policy_insert_inexact_list(chain, policy);
1203
1204        if (delpol)
1205                __xfrm_policy_inexact_prune_bin(bin, false);
1206
1207        return delpol;
1208}
1209
1210static void xfrm_hash_rebuild(struct work_struct *work)
1211{
1212        struct net *net = container_of(work, struct net,
1213                                       xfrm.policy_hthresh.work);
1214        unsigned int hmask;
1215        struct xfrm_policy *pol;
1216        struct xfrm_policy *policy;
1217        struct hlist_head *chain;
1218        struct hlist_head *odst;
1219        struct hlist_node *newpos;
1220        int i;
1221        int dir;
1222        unsigned seq;
1223        u8 lbits4, rbits4, lbits6, rbits6;
1224
1225        mutex_lock(&hash_resize_mutex);
1226
1227        /* read selector prefixlen thresholds */
1228        do {
1229                seq = read_seqbegin(&net->xfrm.policy_hthresh.lock);
1230
1231                lbits4 = net->xfrm.policy_hthresh.lbits4;
1232                rbits4 = net->xfrm.policy_hthresh.rbits4;
1233                lbits6 = net->xfrm.policy_hthresh.lbits6;
1234                rbits6 = net->xfrm.policy_hthresh.rbits6;
1235        } while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
1236
1237        spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1238        write_seqcount_begin(&xfrm_policy_hash_generation);
1239
1240        /* make sure that we can insert the indirect policies again before
1241         * we start with destructive action.
1242         */
1243        list_for_each_entry(policy, &net->xfrm.policy_all, walk.all) {
1244                struct xfrm_pol_inexact_bin *bin;
1245                u8 dbits, sbits;
1246
1247                dir = xfrm_policy_id2dir(policy->index);
1248                if (policy->walk.dead || dir >= XFRM_POLICY_MAX)
1249                        continue;
1250
1251                if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
1252                        if (policy->family == AF_INET) {
1253                                dbits = rbits4;
1254                                sbits = lbits4;
1255                        } else {
1256                                dbits = rbits6;
1257                                sbits = lbits6;
1258                        }
1259                } else {
1260                        if (policy->family == AF_INET) {
1261                                dbits = lbits4;
1262                                sbits = rbits4;
1263                        } else {
1264                                dbits = lbits6;
1265                                sbits = rbits6;
1266                        }
1267                }
1268
1269                if (policy->selector.prefixlen_d < dbits ||
1270                    policy->selector.prefixlen_s < sbits)
1271                        continue;
1272
1273                bin = xfrm_policy_inexact_alloc_bin(policy, dir);
1274                if (!bin)
1275                        goto out_unlock;
1276
1277                if (!xfrm_policy_inexact_alloc_chain(bin, policy, dir))
1278                        goto out_unlock;
1279        }
1280
1281        /* reset the bydst and inexact table in all directions */
1282        for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
1283                struct hlist_node *n;
1284
1285                hlist_for_each_entry_safe(policy, n,
1286                                          &net->xfrm.policy_inexact[dir],
1287                                          bydst_inexact_list) {
1288                        hlist_del_rcu(&policy->bydst);
1289                        hlist_del_init(&policy->bydst_inexact_list);
1290                }
1291
1292                hmask = net->xfrm.policy_bydst[dir].hmask;
1293                odst = net->xfrm.policy_bydst[dir].table;
1294                for (i = hmask; i >= 0; i--) {
1295                        hlist_for_each_entry_safe(policy, n, odst + i, bydst)
1296                                hlist_del_rcu(&policy->bydst);
1297                }
1298                if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
1299                        /* dir out => dst = remote, src = local */
1300                        net->xfrm.policy_bydst[dir].dbits4 = rbits4;
1301                        net->xfrm.policy_bydst[dir].sbits4 = lbits4;
1302                        net->xfrm.policy_bydst[dir].dbits6 = rbits6;
1303                        net->xfrm.policy_bydst[dir].sbits6 = lbits6;
1304                } else {
1305                        /* dir in/fwd => dst = local, src = remote */
1306                        net->xfrm.policy_bydst[dir].dbits4 = lbits4;
1307                        net->xfrm.policy_bydst[dir].sbits4 = rbits4;
1308                        net->xfrm.policy_bydst[dir].dbits6 = lbits6;
1309                        net->xfrm.policy_bydst[dir].sbits6 = rbits6;
1310                }
1311        }
1312
1313        /* re-insert all policies by order of creation */
1314        list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
1315                if (policy->walk.dead)
1316                        continue;
1317                dir = xfrm_policy_id2dir(policy->index);
1318                if (dir >= XFRM_POLICY_MAX) {
1319                        /* skip socket policies */
1320                        continue;
1321                }
1322                newpos = NULL;
1323                chain = policy_hash_bysel(net, &policy->selector,
1324                                          policy->family, dir);
1325
1326                if (!chain) {
1327                        void *p = xfrm_policy_inexact_insert(policy, dir, 0);
1328
1329                        WARN_ONCE(IS_ERR(p), "reinsert: %ld\n", PTR_ERR(p));
1330                        continue;
1331                }
1332
1333                hlist_for_each_entry(pol, chain, bydst) {
1334                        if (policy->priority >= pol->priority)
1335                                newpos = &pol->bydst;
1336                        else
1337                                break;
1338                }
1339                if (newpos)
1340                        hlist_add_behind_rcu(&policy->bydst, newpos);
1341                else
1342                        hlist_add_head_rcu(&policy->bydst, chain);
1343        }
1344
1345out_unlock:
1346        __xfrm_policy_inexact_flush(net);
1347        write_seqcount_end(&xfrm_policy_hash_generation);
1348        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1349
1350        mutex_unlock(&hash_resize_mutex);
1351}
1352
1353void xfrm_policy_hash_rebuild(struct net *net)
1354{
1355        schedule_work(&net->xfrm.policy_hthresh.work);
1356}
1357EXPORT_SYMBOL(xfrm_policy_hash_rebuild);
1358
1359/* Generate new index... KAME seems to generate them ordered by cost
1360 * of an absolute inpredictability of ordering of rules. This will not pass. */
1361static u32 xfrm_gen_index(struct net *net, int dir, u32 index)
1362{
1363        static u32 idx_generator;
1364
1365        for (;;) {
1366                struct hlist_head *list;
1367                struct xfrm_policy *p;
1368                u32 idx;
1369                int found;
1370
1371                if (!index) {
1372                        idx = (idx_generator | dir);
1373                        idx_generator += 8;
1374                } else {
1375                        idx = index;
1376                        index = 0;
1377                }
1378
1379                if (idx == 0)
1380                        idx = 8;
1381                list = net->xfrm.policy_byidx + idx_hash(net, idx);
1382                found = 0;
1383                hlist_for_each_entry(p, list, byidx) {
1384                        if (p->index == idx) {
1385                                found = 1;
1386                                break;
1387                        }
1388                }
1389                if (!found)
1390                        return idx;
1391        }
1392}
1393
1394static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
1395{
1396        u32 *p1 = (u32 *) s1;
1397        u32 *p2 = (u32 *) s2;
1398        int len = sizeof(struct xfrm_selector) / sizeof(u32);
1399        int i;
1400
1401        for (i = 0; i < len; i++) {
1402                if (p1[i] != p2[i])
1403                        return 1;
1404        }
1405
1406        return 0;
1407}
1408
1409static void xfrm_policy_requeue(struct xfrm_policy *old,
1410                                struct xfrm_policy *new)
1411{
1412        struct xfrm_policy_queue *pq = &old->polq;
1413        struct sk_buff_head list;
1414
1415        if (skb_queue_empty(&pq->hold_queue))
1416                return;
1417
1418        __skb_queue_head_init(&list);
1419
1420        spin_lock_bh(&pq->hold_queue.lock);
1421        skb_queue_splice_init(&pq->hold_queue, &list);
1422        if (del_timer(&pq->hold_timer))
1423                xfrm_pol_put(old);
1424        spin_unlock_bh(&pq->hold_queue.lock);
1425
1426        pq = &new->polq;
1427
1428        spin_lock_bh(&pq->hold_queue.lock);
1429        skb_queue_splice(&list, &pq->hold_queue);
1430        pq->timeout = XFRM_QUEUE_TMO_MIN;
1431        if (!mod_timer(&pq->hold_timer, jiffies))
1432                xfrm_pol_hold(new);
1433        spin_unlock_bh(&pq->hold_queue.lock);
1434}
1435
1436static inline bool xfrm_policy_mark_match(const struct xfrm_mark *mark,
1437                                          struct xfrm_policy *pol)
1438{
1439        return mark->v == pol->mark.v && mark->m == pol->mark.m;
1440}
1441
1442static u32 xfrm_pol_bin_key(const void *data, u32 len, u32 seed)
1443{
1444        const struct xfrm_pol_inexact_key *k = data;
1445        u32 a = k->type << 24 | k->dir << 16 | k->family;
1446
1447        return jhash_3words(a, k->if_id, net_hash_mix(read_pnet(&k->net)),
1448                            seed);
1449}
1450
1451static u32 xfrm_pol_bin_obj(const void *data, u32 len, u32 seed)
1452{
1453        const struct xfrm_pol_inexact_bin *b = data;
1454
1455        return xfrm_pol_bin_key(&b->k, 0, seed);
1456}
1457
1458static int xfrm_pol_bin_cmp(struct rhashtable_compare_arg *arg,
1459                            const void *ptr)
1460{
1461        const struct xfrm_pol_inexact_key *key = arg->key;
1462        const struct xfrm_pol_inexact_bin *b = ptr;
1463        int ret;
1464
1465        if (!net_eq(read_pnet(&b->k.net), read_pnet(&key->net)))
1466                return -1;
1467
1468        ret = b->k.dir ^ key->dir;
1469        if (ret)
1470                return ret;
1471
1472        ret = b->k.type ^ key->type;
1473        if (ret)
1474                return ret;
1475
1476        ret = b->k.family ^ key->family;
1477        if (ret)
1478                return ret;
1479
1480        return b->k.if_id ^ key->if_id;
1481}
1482
1483static const struct rhashtable_params xfrm_pol_inexact_params = {
1484        .head_offset            = offsetof(struct xfrm_pol_inexact_bin, head),
1485        .hashfn                 = xfrm_pol_bin_key,
1486        .obj_hashfn             = xfrm_pol_bin_obj,
1487        .obj_cmpfn              = xfrm_pol_bin_cmp,
1488        .automatic_shrinking    = true,
1489};
1490
1491static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
1492                                            struct xfrm_policy *policy)
1493{
1494        struct xfrm_policy *pol, *delpol = NULL;
1495        struct hlist_node *newpos = NULL;
1496        int i = 0;
1497
1498        hlist_for_each_entry(pol, chain, bydst_inexact_list) {
1499                if (pol->type == policy->type &&
1500                    pol->if_id == policy->if_id &&
1501                    !selector_cmp(&pol->selector, &policy->selector) &&
1502                    xfrm_policy_mark_match(&policy->mark, pol) &&
1503                    xfrm_sec_ctx_match(pol->security, policy->security) &&
1504                    !WARN_ON(delpol)) {
1505                        delpol = pol;
1506                        if (policy->priority > pol->priority)
1507                                continue;
1508                } else if (policy->priority >= pol->priority) {
1509                        newpos = &pol->bydst_inexact_list;
1510                        continue;
1511                }
1512                if (delpol)
1513                        break;
1514        }
1515
1516        if (newpos)
1517                hlist_add_behind_rcu(&policy->bydst_inexact_list, newpos);
1518        else
1519                hlist_add_head_rcu(&policy->bydst_inexact_list, chain);
1520
1521        hlist_for_each_entry(pol, chain, bydst_inexact_list) {
1522                pol->pos = i;
1523                i++;
1524        }
1525}
1526
1527static struct xfrm_policy *xfrm_policy_insert_list(struct hlist_head *chain,
1528                                                   struct xfrm_policy *policy,
1529                                                   bool excl)
1530{
1531        struct xfrm_policy *pol, *newpos = NULL, *delpol = NULL;
1532
1533        hlist_for_each_entry(pol, chain, bydst) {
1534                if (pol->type == policy->type &&
1535                    pol->if_id == policy->if_id &&
1536                    !selector_cmp(&pol->selector, &policy->selector) &&
1537                    xfrm_policy_mark_match(&policy->mark, pol) &&
1538                    xfrm_sec_ctx_match(pol->security, policy->security) &&
1539                    !WARN_ON(delpol)) {
1540                        if (excl)
1541                                return ERR_PTR(-EEXIST);
1542                        delpol = pol;
1543                        if (policy->priority > pol->priority)
1544                                continue;
1545                } else if (policy->priority >= pol->priority) {
1546                        newpos = pol;
1547                        continue;
1548                }
1549                if (delpol)
1550                        break;
1551        }
1552
1553        if (newpos)
1554                hlist_add_behind_rcu(&policy->bydst, &newpos->bydst);
1555        else
1556                hlist_add_head_rcu(&policy->bydst, chain);
1557
1558        return delpol;
1559}
1560
1561int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
1562{
1563        struct net *net = xp_net(policy);
1564        struct xfrm_policy *delpol;
1565        struct hlist_head *chain;
1566
1567        spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1568        chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
1569        if (chain)
1570                delpol = xfrm_policy_insert_list(chain, policy, excl);
1571        else
1572                delpol = xfrm_policy_inexact_insert(policy, dir, excl);
1573
1574        if (IS_ERR(delpol)) {
1575                spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1576                return PTR_ERR(delpol);
1577        }
1578
1579        __xfrm_policy_link(policy, dir);
1580
1581        /* After previous checking, family can either be AF_INET or AF_INET6 */
1582        if (policy->family == AF_INET)
1583                rt_genid_bump_ipv4(net);
1584        else
1585                rt_genid_bump_ipv6(net);
1586
1587        if (delpol) {
1588                xfrm_policy_requeue(delpol, policy);
1589                __xfrm_policy_unlink(delpol, dir);
1590        }
1591        policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir, policy->index);
1592        hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
1593        policy->curlft.add_time = ktime_get_real_seconds();
1594        policy->curlft.use_time = 0;
1595        if (!mod_timer(&policy->timer, jiffies + HZ))
1596                xfrm_pol_hold(policy);
1597        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1598
1599        if (delpol)
1600                xfrm_policy_kill(delpol);
1601        else if (xfrm_bydst_should_resize(net, dir, NULL))
1602                schedule_work(&net->xfrm.policy_hash_work);
1603
1604        return 0;
1605}
1606EXPORT_SYMBOL(xfrm_policy_insert);
1607
1608static struct xfrm_policy *
1609__xfrm_policy_bysel_ctx(struct hlist_head *chain, const struct xfrm_mark *mark,
1610                        u32 if_id, u8 type, int dir, struct xfrm_selector *sel,
1611                        struct xfrm_sec_ctx *ctx)
1612{
1613        struct xfrm_policy *pol;
1614
1615        if (!chain)
1616                return NULL;
1617
1618        hlist_for_each_entry(pol, chain, bydst) {
1619                if (pol->type == type &&
1620                    pol->if_id == if_id &&
1621                    xfrm_policy_mark_match(mark, pol) &&
1622                    !selector_cmp(sel, &pol->selector) &&
1623                    xfrm_sec_ctx_match(ctx, pol->security))
1624                        return pol;
1625        }
1626
1627        return NULL;
1628}
1629
1630struct xfrm_policy *
1631xfrm_policy_bysel_ctx(struct net *net, const struct xfrm_mark *mark, u32 if_id,
1632                      u8 type, int dir, struct xfrm_selector *sel,
1633                      struct xfrm_sec_ctx *ctx, int delete, int *err)
1634{
1635        struct xfrm_pol_inexact_bin *bin = NULL;
1636        struct xfrm_policy *pol, *ret = NULL;
1637        struct hlist_head *chain;
1638
1639        *err = 0;
1640        spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1641        chain = policy_hash_bysel(net, sel, sel->family, dir);
1642        if (!chain) {
1643                struct xfrm_pol_inexact_candidates cand;
1644                int i;
1645
1646                bin = xfrm_policy_inexact_lookup(net, type,
1647                                                 sel->family, dir, if_id);
1648                if (!bin) {
1649                        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1650                        return NULL;
1651                }
1652
1653                if (!xfrm_policy_find_inexact_candidates(&cand, bin,
1654                                                         &sel->saddr,
1655                                                         &sel->daddr)) {
1656                        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1657                        return NULL;
1658                }
1659
1660                pol = NULL;
1661                for (i = 0; i < ARRAY_SIZE(cand.res); i++) {
1662                        struct xfrm_policy *tmp;
1663
1664                        tmp = __xfrm_policy_bysel_ctx(cand.res[i], mark,
1665                                                      if_id, type, dir,
1666                                                      sel, ctx);
1667                        if (!tmp)
1668                                continue;
1669
1670                        if (!pol || tmp->pos < pol->pos)
1671                                pol = tmp;
1672                }
1673        } else {
1674                pol = __xfrm_policy_bysel_ctx(chain, mark, if_id, type, dir,
1675                                              sel, ctx);
1676        }
1677
1678        if (pol) {
1679                xfrm_pol_hold(pol);
1680                if (delete) {
1681                        *err = security_xfrm_policy_delete(pol->security);
1682                        if (*err) {
1683                                spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1684                                return pol;
1685                        }
1686                        __xfrm_policy_unlink(pol, dir);
1687                }
1688                ret = pol;
1689        }
1690        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1691
1692        if (ret && delete)
1693                xfrm_policy_kill(ret);
1694        if (bin && delete)
1695                xfrm_policy_inexact_prune_bin(bin);
1696        return ret;
1697}
1698EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
1699
1700struct xfrm_policy *
1701xfrm_policy_byid(struct net *net, const struct xfrm_mark *mark, u32 if_id,
1702                 u8 type, int dir, u32 id, int delete, int *err)
1703{
1704        struct xfrm_policy *pol, *ret;
1705        struct hlist_head *chain;
1706
1707        *err = -ENOENT;
1708        if (xfrm_policy_id2dir(id) != dir)
1709                return NULL;
1710
1711        *err = 0;
1712        spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1713        chain = net->xfrm.policy_byidx + idx_hash(net, id);
1714        ret = NULL;
1715        hlist_for_each_entry(pol, chain, byidx) {
1716                if (pol->type == type && pol->index == id &&
1717                    pol->if_id == if_id && xfrm_policy_mark_match(mark, pol)) {
1718                        xfrm_pol_hold(pol);
1719                        if (delete) {
1720                                *err = security_xfrm_policy_delete(
1721                                                                pol->security);
1722                                if (*err) {
1723                                        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1724                                        return pol;
1725                                }
1726                                __xfrm_policy_unlink(pol, dir);
1727                        }
1728                        ret = pol;
1729                        break;
1730                }
1731        }
1732        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1733
1734        if (ret && delete)
1735                xfrm_policy_kill(ret);
1736        return ret;
1737}
1738EXPORT_SYMBOL(xfrm_policy_byid);
1739
1740#ifdef CONFIG_SECURITY_NETWORK_XFRM
1741static inline int
1742xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
1743{
1744        struct xfrm_policy *pol;
1745        int err = 0;
1746
1747        list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
1748                if (pol->walk.dead ||
1749                    xfrm_policy_id2dir(pol->index) >= XFRM_POLICY_MAX ||
1750                    pol->type != type)
1751                        continue;
1752
1753                err = security_xfrm_policy_delete(pol->security);
1754                if (err) {
1755                        xfrm_audit_policy_delete(pol, 0, task_valid);
1756                        return err;
1757                }
1758        }
1759        return err;
1760}
1761#else
1762static inline int
1763xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
1764{
1765        return 0;
1766}
1767#endif
1768
1769int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
1770{
1771        int dir, err = 0, cnt = 0;
1772        struct xfrm_policy *pol;
1773
1774        spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1775
1776        err = xfrm_policy_flush_secctx_check(net, type, task_valid);
1777        if (err)
1778                goto out;
1779
1780again:
1781        list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
1782                dir = xfrm_policy_id2dir(pol->index);
1783                if (pol->walk.dead ||
1784                    dir >= XFRM_POLICY_MAX ||
1785                    pol->type != type)
1786                        continue;
1787
1788                __xfrm_policy_unlink(pol, dir);
1789                spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1790                cnt++;
1791                xfrm_audit_policy_delete(pol, 1, task_valid);
1792                xfrm_policy_kill(pol);
1793                spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1794                goto again;
1795        }
1796        if (cnt)
1797                __xfrm_policy_inexact_flush(net);
1798        else
1799                err = -ESRCH;
1800out:
1801        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1802        return err;
1803}
1804EXPORT_SYMBOL(xfrm_policy_flush);
1805
1806int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
1807                     int (*func)(struct xfrm_policy *, int, int, void*),
1808                     void *data)
1809{
1810        struct xfrm_policy *pol;
1811        struct xfrm_policy_walk_entry *x;
1812        int error = 0;
1813
1814        if (walk->type >= XFRM_POLICY_TYPE_MAX &&
1815            walk->type != XFRM_POLICY_TYPE_ANY)
1816                return -EINVAL;
1817
1818        if (list_empty(&walk->walk.all) && walk->seq != 0)
1819                return 0;
1820
1821        spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1822        if (list_empty(&walk->walk.all))
1823                x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
1824        else
1825                x = list_first_entry(&walk->walk.all,
1826                                     struct xfrm_policy_walk_entry, all);
1827
1828        list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
1829                if (x->dead)
1830                        continue;
1831                pol = container_of(x, struct xfrm_policy, walk);
1832                if (walk->type != XFRM_POLICY_TYPE_ANY &&
1833                    walk->type != pol->type)
1834                        continue;
1835                error = func(pol, xfrm_policy_id2dir(pol->index),
1836                             walk->seq, data);
1837                if (error) {
1838                        list_move_tail(&walk->walk.all, &x->all);
1839                        goto out;
1840                }
1841                walk->seq++;
1842        }
1843        if (walk->seq == 0) {
1844                error = -ENOENT;
1845                goto out;
1846        }
1847        list_del_init(&walk->walk.all);
1848out:
1849        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1850        return error;
1851}
1852EXPORT_SYMBOL(xfrm_policy_walk);
1853
1854void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
1855{
1856        INIT_LIST_HEAD(&walk->walk.all);
1857        walk->walk.dead = 1;
1858        walk->type = type;
1859        walk->seq = 0;
1860}
1861EXPORT_SYMBOL(xfrm_policy_walk_init);
1862
1863void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net)
1864{
1865        if (list_empty(&walk->walk.all))
1866                return;
1867
1868        spin_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */
1869        list_del(&walk->walk.all);
1870        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1871}
1872EXPORT_SYMBOL(xfrm_policy_walk_done);
1873
1874/*
1875 * Find policy to apply to this flow.
1876 *
1877 * Returns 0 if policy found, else an -errno.
1878 */
1879static int xfrm_policy_match(const struct xfrm_policy *pol,
1880                             const struct flowi *fl,
1881                             u8 type, u16 family, int dir, u32 if_id)
1882{
1883        const struct xfrm_selector *sel = &pol->selector;
1884        int ret = -ESRCH;
1885        bool match;
1886
1887        if (pol->family != family ||
1888            pol->if_id != if_id ||
1889            (fl->flowi_mark & pol->mark.m) != pol->mark.v ||
1890            pol->type != type)
1891                return ret;
1892
1893        match = xfrm_selector_match(sel, fl, family);
1894        if (match)
1895                ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid,
1896                                                  dir);
1897        return ret;
1898}
1899
1900static struct xfrm_pol_inexact_node *
1901xfrm_policy_lookup_inexact_addr(const struct rb_root *r,
1902                                seqcount_spinlock_t *count,
1903                                const xfrm_address_t *addr, u16 family)
1904{
1905        const struct rb_node *parent;
1906        int seq;
1907
1908again:
1909        seq = read_seqcount_begin(count);
1910
1911        parent = rcu_dereference_raw(r->rb_node);
1912        while (parent) {
1913                struct xfrm_pol_inexact_node *node;
1914                int delta;
1915
1916                node = rb_entry(parent, struct xfrm_pol_inexact_node, node);
1917
1918                delta = xfrm_policy_addr_delta(addr, &node->addr,
1919                                               node->prefixlen, family);
1920                if (delta < 0) {
1921                        parent = rcu_dereference_raw(parent->rb_left);
1922                        continue;
1923                } else if (delta > 0) {
1924                        parent = rcu_dereference_raw(parent->rb_right);
1925                        continue;
1926                }
1927
1928                return node;
1929        }
1930
1931        if (read_seqcount_retry(count, seq))
1932                goto again;
1933
1934        return NULL;
1935}
1936
1937static bool
1938xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
1939                                    struct xfrm_pol_inexact_bin *b,
1940                                    const xfrm_address_t *saddr,
1941                                    const xfrm_address_t *daddr)
1942{
1943        struct xfrm_pol_inexact_node *n;
1944        u16 family;
1945
1946        if (!b)
1947                return false;
1948
1949        family = b->k.family;
1950        memset(cand, 0, sizeof(*cand));
1951        cand->res[XFRM_POL_CAND_ANY] = &b->hhead;
1952
1953        n = xfrm_policy_lookup_inexact_addr(&b->root_d, &b->count, daddr,
1954                                            family);
1955        if (n) {
1956                cand->res[XFRM_POL_CAND_DADDR] = &n->hhead;
1957                n = xfrm_policy_lookup_inexact_addr(&n->root, &b->count, saddr,
1958                                                    family);
1959                if (n)
1960                        cand->res[XFRM_POL_CAND_BOTH] = &n->hhead;
1961        }
1962
1963        n = xfrm_policy_lookup_inexact_addr(&b->root_s, &b->count, saddr,
1964                                            family);
1965        if (n)
1966                cand->res[XFRM_POL_CAND_SADDR] = &n->hhead;
1967
1968        return true;
1969}
1970
1971static struct xfrm_pol_inexact_bin *
1972xfrm_policy_inexact_lookup_rcu(struct net *net, u8 type, u16 family,
1973                               u8 dir, u32 if_id)
1974{
1975        struct xfrm_pol_inexact_key k = {
1976                .family = family,
1977                .type = type,
1978                .dir = dir,
1979                .if_id = if_id,
1980        };
1981
1982        write_pnet(&k.net, net);
1983
1984        return rhashtable_lookup(&xfrm_policy_inexact_table, &k,
1985                                 xfrm_pol_inexact_params);
1986}
1987
1988static struct xfrm_pol_inexact_bin *
1989xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family,
1990                           u8 dir, u32 if_id)
1991{
1992        struct xfrm_pol_inexact_bin *bin;
1993
1994        lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1995
1996        rcu_read_lock();
1997        bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
1998        rcu_read_unlock();
1999
2000        return bin;
2001}
2002
2003static struct xfrm_policy *
2004__xfrm_policy_eval_candidates(struct hlist_head *chain,
2005                              struct xfrm_policy *prefer,
2006                              const struct flowi *fl,
2007                              u8 type, u16 family, int dir, u32 if_id)
2008{
2009        u32 priority = prefer ? prefer->priority : ~0u;
2010        struct xfrm_policy *pol;
2011
2012        if (!chain)
2013                return NULL;
2014
2015        hlist_for_each_entry_rcu(pol, chain, bydst) {
2016                int err;
2017
2018                if (pol->priority > priority)
2019                        break;
2020
2021                err = xfrm_policy_match(pol, fl, type, family, dir, if_id);
2022                if (err) {
2023                        if (err != -ESRCH)
2024                                return ERR_PTR(err);
2025
2026                        continue;
2027                }
2028
2029                if (prefer) {
2030                        /* matches.  Is it older than *prefer? */
2031                        if (pol->priority == priority &&
2032                            prefer->pos < pol->pos)
2033                                return prefer;
2034                }
2035
2036                return pol;
2037        }
2038
2039        return NULL;
2040}
2041
2042static struct xfrm_policy *
2043xfrm_policy_eval_candidates(struct xfrm_pol_inexact_candidates *cand,
2044                            struct xfrm_policy *prefer,
2045                            const struct flowi *fl,
2046                            u8 type, u16 family, int dir, u32 if_id)
2047{
2048        struct xfrm_policy *tmp;
2049        int i;
2050
2051        for (i = 0; i < ARRAY_SIZE(cand->res); i++) {
2052                tmp = __xfrm_policy_eval_candidates(cand->res[i],
2053                                                    prefer,
2054                                                    fl, type, family, dir,
2055                                                    if_id);
2056                if (!tmp)
2057                        continue;
2058
2059                if (IS_ERR(tmp))
2060                        return tmp;
2061                prefer = tmp;
2062        }
2063
2064        return prefer;
2065}
2066
2067static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
2068                                                     const struct flowi *fl,
2069                                                     u16 family, u8 dir,
2070                                                     u32 if_id)
2071{
2072        struct xfrm_pol_inexact_candidates cand;
2073        const xfrm_address_t *daddr, *saddr;
2074        struct xfrm_pol_inexact_bin *bin;
2075        struct xfrm_policy *pol, *ret;
2076        struct hlist_head *chain;
2077        unsigned int sequence;
2078        int err;
2079
2080        daddr = xfrm_flowi_daddr(fl, family);
2081        saddr = xfrm_flowi_saddr(fl, family);
2082        if (unlikely(!daddr || !saddr))
2083                return NULL;
2084
2085        rcu_read_lock();
2086 retry:
2087        do {
2088                sequence = read_seqcount_begin(&xfrm_policy_hash_generation);
2089                chain = policy_hash_direct(net, daddr, saddr, family, dir);
2090        } while (read_seqcount_retry(&xfrm_policy_hash_generation, sequence));
2091
2092        ret = NULL;
2093        hlist_for_each_entry_rcu(pol, chain, bydst) {
2094                err = xfrm_policy_match(pol, fl, type, family, dir, if_id);
2095                if (err) {
2096                        if (err == -ESRCH)
2097                                continue;
2098                        else {
2099                                ret = ERR_PTR(err);
2100                                goto fail;
2101                        }
2102                } else {
2103                        ret = pol;
2104                        break;
2105                }
2106        }
2107        bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
2108        if (!bin || !xfrm_policy_find_inexact_candidates(&cand, bin, saddr,
2109                                                         daddr))
2110                goto skip_inexact;
2111
2112        pol = xfrm_policy_eval_candidates(&cand, ret, fl, type,
2113                                          family, dir, if_id);
2114        if (pol) {
2115                ret = pol;
2116                if (IS_ERR(pol))
2117                        goto fail;
2118        }
2119
2120skip_inexact:
2121        if (read_seqcount_retry(&xfrm_policy_hash_generation, sequence))
2122                goto retry;
2123
2124        if (ret && !xfrm_pol_hold_rcu(ret))
2125                goto retry;
2126fail:
2127        rcu_read_unlock();
2128
2129        return ret;
2130}
2131
2132static struct xfrm_policy *xfrm_policy_lookup(struct net *net,
2133                                              const struct flowi *fl,
2134                                              u16 family, u8 dir, u32 if_id)
2135{
2136#ifdef CONFIG_XFRM_SUB_POLICY
2137        struct xfrm_policy *pol;
2138
2139        pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family,
2140                                        dir, if_id);
2141        if (pol != NULL)
2142                return pol;
2143#endif
2144        return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family,
2145                                         dir, if_id);
2146}
2147
2148static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
2149                                                 const struct flowi *fl,
2150                                                 u16 family, u32 if_id)
2151{
2152        struct xfrm_policy *pol;
2153
2154        rcu_read_lock();
2155 again:
2156        pol = rcu_dereference(sk->sk_policy[dir]);
2157        if (pol != NULL) {
2158                bool match;
2159                int err = 0;
2160
2161                if (pol->family != family) {
2162                        pol = NULL;
2163                        goto out;
2164                }
2165
2166                match = xfrm_selector_match(&pol->selector, fl, family);
2167                if (match) {
2168                        if ((sk->sk_mark & pol->mark.m) != pol->mark.v ||
2169                            pol->if_id != if_id) {
2170                                pol = NULL;
2171                                goto out;
2172                        }
2173                        err = security_xfrm_policy_lookup(pol->security,
2174                                                      fl->flowi_secid,
2175                                                      dir);
2176                        if (!err) {
2177                                if (!xfrm_pol_hold_rcu(pol))
2178                                        goto again;
2179                        } else if (err == -ESRCH) {
2180                                pol = NULL;
2181                        } else {
2182                                pol = ERR_PTR(err);
2183                        }
2184                } else
2185                        pol = NULL;
2186        }
2187out:
2188        rcu_read_unlock();
2189        return pol;
2190}
2191
2192static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
2193{
2194        struct net *net = xp_net(pol);
2195
2196        list_add(&pol->walk.all, &net->xfrm.policy_all);
2197        net->xfrm.policy_count[dir]++;
2198        xfrm_pol_hold(pol);
2199}
2200
2201static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
2202                                                int dir)
2203{
2204        struct net *net = xp_net(pol);
2205
2206        if (list_empty(&pol->walk.all))
2207                return NULL;
2208
2209        /* Socket policies are not hashed. */
2210        if (!hlist_unhashed(&pol->bydst)) {
2211                hlist_del_rcu(&pol->bydst);
2212                hlist_del_init(&pol->bydst_inexact_list);
2213                hlist_del(&pol->byidx);
2214        }
2215
2216        list_del_init(&pol->walk.all);
2217        net->xfrm.policy_count[dir]--;
2218
2219        return pol;
2220}
2221
2222static void xfrm_sk_policy_link(struct xfrm_policy *pol, int dir)
2223{
2224        __xfrm_policy_link(pol, XFRM_POLICY_MAX + dir);
2225}
2226
2227static void xfrm_sk_policy_unlink(struct xfrm_policy *pol, int dir)
2228{
2229        __xfrm_policy_unlink(pol, XFRM_POLICY_MAX + dir);
2230}
2231
2232int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
2233{
2234        struct net *net = xp_net(pol);
2235
2236        spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2237        pol = __xfrm_policy_unlink(pol, dir);
2238        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2239        if (pol) {
2240                xfrm_policy_kill(pol);
2241                return 0;
2242        }
2243        return -ENOENT;
2244}
2245EXPORT_SYMBOL(xfrm_policy_delete);
2246
2247int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
2248{
2249        struct net *net = sock_net(sk);
2250        struct xfrm_policy *old_pol;
2251
2252#ifdef CONFIG_XFRM_SUB_POLICY
2253        if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
2254                return -EINVAL;
2255#endif
2256
2257        spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2258        old_pol = rcu_dereference_protected(sk->sk_policy[dir],
2259                                lockdep_is_held(&net->xfrm.xfrm_policy_lock));
2260        if (pol) {
2261                pol->curlft.add_time = ktime_get_real_seconds();
2262                pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0);
2263                xfrm_sk_policy_link(pol, dir);
2264        }
2265        rcu_assign_pointer(sk->sk_policy[dir], pol);
2266        if (old_pol) {
2267                if (pol)
2268                        xfrm_policy_requeue(old_pol, pol);
2269
2270                /* Unlinking succeeds always. This is the only function
2271                 * allowed to delete or replace socket policy.
2272                 */
2273                xfrm_sk_policy_unlink(old_pol, dir);
2274        }
2275        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2276
2277        if (old_pol) {
2278                xfrm_policy_kill(old_pol);
2279        }
2280        return 0;
2281}
2282
2283static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
2284{
2285        struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
2286        struct net *net = xp_net(old);
2287
2288        if (newp) {
2289                newp->selector = old->selector;
2290                if (security_xfrm_policy_clone(old->security,
2291                                               &newp->security)) {
2292                        kfree(newp);
2293                        return NULL;  /* ENOMEM */
2294                }
2295                newp->lft = old->lft;
2296                newp->curlft = old->curlft;
2297                newp->mark = old->mark;
2298                newp->if_id = old->if_id;
2299                newp->action = old->action;
2300                newp->flags = old->flags;
2301                newp->xfrm_nr = old->xfrm_nr;
2302                newp->index = old->index;
2303                newp->type = old->type;
2304                newp->family = old->family;
2305                memcpy(newp->xfrm_vec, old->xfrm_vec,
2306                       newp->xfrm_nr*sizeof(struct xfrm_tmpl));
2307                spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2308                xfrm_sk_policy_link(newp, dir);
2309                spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2310                xfrm_pol_put(newp);
2311        }
2312        return newp;
2313}
2314
2315int __xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk)
2316{
2317        const struct xfrm_policy *p;
2318        struct xfrm_policy *np;
2319        int i, ret = 0;
2320
2321        rcu_read_lock();
2322        for (i = 0; i < 2; i++) {
2323                p = rcu_dereference(osk->sk_policy[i]);
2324                if (p) {
2325                        np = clone_policy(p, i);
2326                        if (unlikely(!np)) {
2327                                ret = -ENOMEM;
2328                                break;
2329                        }
2330                        rcu_assign_pointer(sk->sk_policy[i], np);
2331                }
2332        }
2333        rcu_read_unlock();
2334        return ret;
2335}
2336
2337static int
2338xfrm_get_saddr(struct net *net, int oif, xfrm_address_t *local,
2339               xfrm_address_t *remote, unsigned short family, u32 mark)
2340{
2341        int err;
2342        const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2343
2344        if (unlikely(afinfo == NULL))
2345                return -EINVAL;
2346        err = afinfo->get_saddr(net, oif, local, remote, mark);
2347        rcu_read_unlock();
2348        return err;
2349}
2350
2351/* Resolve list of templates for the flow, given policy. */
2352
2353static int
2354xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
2355                      struct xfrm_state **xfrm, unsigned short family)
2356{
2357        struct net *net = xp_net(policy);
2358        int nx;
2359        int i, error;
2360        xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
2361        xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
2362        xfrm_address_t tmp;
2363
2364        for (nx = 0, i = 0; i < policy->xfrm_nr; i++) {
2365                struct xfrm_state *x;
2366                xfrm_address_t *remote = daddr;
2367                xfrm_address_t *local  = saddr;
2368                struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
2369
2370                if (tmpl->mode == XFRM_MODE_TUNNEL ||
2371                    tmpl->mode == XFRM_MODE_BEET) {
2372                        remote = &tmpl->id.daddr;
2373                        local = &tmpl->saddr;
2374                        if (xfrm_addr_any(local, tmpl->encap_family)) {
2375                                error = xfrm_get_saddr(net, fl->flowi_oif,
2376                                                       &tmp, remote,
2377                                                       tmpl->encap_family, 0);
2378                                if (error)
2379                                        goto fail;
2380                                local = &tmp;
2381                        }
2382                }
2383
2384                x = xfrm_state_find(remote, local, fl, tmpl, policy, &error,
2385                                    family, policy->if_id);
2386
2387                if (x && x->km.state == XFRM_STATE_VALID) {
2388                        xfrm[nx++] = x;
2389                        daddr = remote;
2390                        saddr = local;
2391                        continue;
2392                }
2393                if (x) {
2394                        error = (x->km.state == XFRM_STATE_ERROR ?
2395                                 -EINVAL : -EAGAIN);
2396                        xfrm_state_put(x);
2397                } else if (error == -ESRCH) {
2398                        error = -EAGAIN;
2399                }
2400
2401                if (!tmpl->optional)
2402                        goto fail;
2403        }
2404        return nx;
2405
2406fail:
2407        for (nx--; nx >= 0; nx--)
2408                xfrm_state_put(xfrm[nx]);
2409        return error;
2410}
2411
2412static int
2413xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
2414                  struct xfrm_state **xfrm, unsigned short family)
2415{
2416        struct xfrm_state *tp[XFRM_MAX_DEPTH];
2417        struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
2418        int cnx = 0;
2419        int error;
2420        int ret;
2421        int i;
2422
2423        for (i = 0; i < npols; i++) {
2424                if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
2425                        error = -ENOBUFS;
2426                        goto fail;
2427                }
2428
2429                ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
2430                if (ret < 0) {
2431                        error = ret;
2432                        goto fail;
2433                } else
2434                        cnx += ret;
2435        }
2436
2437        /* found states are sorted for outbound processing */
2438        if (npols > 1)
2439                xfrm_state_sort(xfrm, tpp, cnx, family);
2440
2441        return cnx;
2442
2443 fail:
2444        for (cnx--; cnx >= 0; cnx--)
2445                xfrm_state_put(tpp[cnx]);
2446        return error;
2447
2448}
2449
2450static int xfrm_get_tos(const struct flowi *fl, int family)
2451{
2452        if (family == AF_INET)
2453                return IPTOS_RT_MASK & fl->u.ip4.flowi4_tos;
2454
2455        return 0;
2456}
2457
2458static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
2459{
2460        const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2461        struct dst_ops *dst_ops;
2462        struct xfrm_dst *xdst;
2463
2464        if (!afinfo)
2465                return ERR_PTR(-EINVAL);
2466
2467        switch (family) {
2468        case AF_INET:
2469                dst_ops = &net->xfrm.xfrm4_dst_ops;
2470                break;
2471#if IS_ENABLED(CONFIG_IPV6)
2472        case AF_INET6:
2473                dst_ops = &net->xfrm.xfrm6_dst_ops;
2474                break;
2475#endif
2476        default:
2477                BUG();
2478        }
2479        xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2480
2481        if (likely(xdst)) {
2482                struct dst_entry *dst = &xdst->u.dst;
2483
2484                memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst));
2485        } else
2486                xdst = ERR_PTR(-ENOBUFS);
2487
2488        rcu_read_unlock();
2489
2490        return xdst;
2491}
2492
2493static void xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
2494                           int nfheader_len)
2495{
2496        if (dst->ops->family == AF_INET6) {
2497                struct rt6_info *rt = (struct rt6_info *)dst;
2498                path->path_cookie = rt6_get_cookie(rt);
2499                path->u.rt6.rt6i_nfheader_len = nfheader_len;
2500        }
2501}
2502
2503static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
2504                                const struct flowi *fl)
2505{
2506        const struct xfrm_policy_afinfo *afinfo =
2507                xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
2508        int err;
2509
2510        if (!afinfo)
2511                return -EINVAL;
2512
2513        err = afinfo->fill_dst(xdst, dev, fl);
2514
2515        rcu_read_unlock();
2516
2517        return err;
2518}
2519
2520
2521/* Allocate chain of dst_entry's, attach known xfrm's, calculate
2522 * all the metrics... Shortly, bundle a bundle.
2523 */
2524
2525static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
2526                                            struct xfrm_state **xfrm,
2527                                            struct xfrm_dst **bundle,
2528                                            int nx,
2529                                            const struct flowi *fl,
2530                                            struct dst_entry *dst)
2531{
2532        const struct xfrm_state_afinfo *afinfo;
2533        const struct xfrm_mode *inner_mode;
2534        struct net *net = xp_net(policy);
2535        unsigned long now = jiffies;
2536        struct net_device *dev;
2537        struct xfrm_dst *xdst_prev = NULL;
2538        struct xfrm_dst *xdst0 = NULL;
2539        int i = 0;
2540        int err;
2541        int header_len = 0;
2542        int nfheader_len = 0;
2543        int trailer_len = 0;
2544        int tos;
2545        int family = policy->selector.family;
2546        xfrm_address_t saddr, daddr;
2547
2548        xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
2549
2550        tos = xfrm_get_tos(fl, family);
2551
2552        dst_hold(dst);
2553
2554        for (; i < nx; i++) {
2555                struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
2556                struct dst_entry *dst1 = &xdst->u.dst;
2557
2558                err = PTR_ERR(xdst);
2559                if (IS_ERR(xdst)) {
2560                        dst_release(dst);
2561                        goto put_states;
2562                }
2563
2564                bundle[i] = xdst;
2565                if (!xdst_prev)
2566                        xdst0 = xdst;
2567                else
2568                        /* Ref count is taken during xfrm_alloc_dst()
2569                         * No need to do dst_clone() on dst1
2570                         */
2571                        xfrm_dst_set_child(xdst_prev, &xdst->u.dst);
2572
2573                if (xfrm[i]->sel.family == AF_UNSPEC) {
2574                        inner_mode = xfrm_ip2inner_mode(xfrm[i],
2575                                                        xfrm_af2proto(family));
2576                        if (!inner_mode) {
2577                                err = -EAFNOSUPPORT;
2578                                dst_release(dst);
2579                                goto put_states;
2580                        }
2581                } else
2582                        inner_mode = &xfrm[i]->inner_mode;
2583
2584                xdst->route = dst;
2585                dst_copy_metrics(dst1, dst);
2586
2587                if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
2588                        __u32 mark = 0;
2589
2590                        if (xfrm[i]->props.smark.v || xfrm[i]->props.smark.m)
2591                                mark = xfrm_smark_get(fl->flowi_mark, xfrm[i]);
2592
2593                        family = xfrm[i]->props.family;
2594                        dst = xfrm_dst_lookup(xfrm[i], tos, fl->flowi_oif,
2595                                              &saddr, &daddr, family, mark);
2596                        err = PTR_ERR(dst);
2597                        if (IS_ERR(dst))
2598                                goto put_states;
2599                } else
2600                        dst_hold(dst);
2601
2602                dst1->xfrm = xfrm[i];
2603                xdst->xfrm_genid = xfrm[i]->genid;
2604
2605                dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2606                dst1->lastuse = now;
2607
2608                dst1->input = dst_discard;
2609
2610                rcu_read_lock();
2611                afinfo = xfrm_state_afinfo_get_rcu(inner_mode->family);
2612                if (likely(afinfo))
2613                        dst1->output = afinfo->output;
2614                else
2615                        dst1->output = dst_discard_out;
2616                rcu_read_unlock();
2617
2618                xdst_prev = xdst;
2619
2620                header_len += xfrm[i]->props.header_len;
2621                if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
2622                        nfheader_len += xfrm[i]->props.header_len;
2623                trailer_len += xfrm[i]->props.trailer_len;
2624        }
2625
2626        xfrm_dst_set_child(xdst_prev, dst);
2627        xdst0->path = dst;
2628
2629        err = -ENODEV;
2630        dev = dst->dev;
2631        if (!dev)
2632                goto free_dst;
2633
2634        xfrm_init_path(xdst0, dst, nfheader_len);
2635        xfrm_init_pmtu(bundle, nx);
2636
2637        for (xdst_prev = xdst0; xdst_prev != (struct xfrm_dst *)dst;
2638             xdst_prev = (struct xfrm_dst *) xfrm_dst_child(&xdst_prev->u.dst)) {
2639                err = xfrm_fill_dst(xdst_prev, dev, fl);
2640                if (err)
2641                        goto free_dst;
2642
2643                xdst_prev->u.dst.header_len = header_len;
2644                xdst_prev->u.dst.trailer_len = trailer_len;
2645                header_len -= xdst_prev->u.dst.xfrm->props.header_len;
2646                trailer_len -= xdst_prev->u.dst.xfrm->props.trailer_len;
2647        }
2648
2649        return &xdst0->u.dst;
2650
2651put_states:
2652        for (; i < nx; i++)
2653                xfrm_state_put(xfrm[i]);
2654free_dst:
2655        if (xdst0)
2656                dst_release_immediate(&xdst0->u.dst);
2657
2658        return ERR_PTR(err);
2659}
2660
2661static int xfrm_expand_policies(const struct flowi *fl, u16 family,
2662                                struct xfrm_policy **pols,
2663                                int *num_pols, int *num_xfrms)
2664{
2665        int i;
2666
2667        if (*num_pols == 0 || !pols[0]) {
2668                *num_pols = 0;
2669                *num_xfrms = 0;
2670                return 0;
2671        }
2672        if (IS_ERR(pols[0]))
2673                return PTR_ERR(pols[0]);
2674
2675        *num_xfrms = pols[0]->xfrm_nr;
2676
2677#ifdef CONFIG_XFRM_SUB_POLICY
2678        if (pols[0] && pols[0]->action == XFRM_POLICY_ALLOW &&
2679            pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2680                pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
2681                                                    XFRM_POLICY_TYPE_MAIN,
2682                                                    fl, family,
2683                                                    XFRM_POLICY_OUT,
2684                                                    pols[0]->if_id);
2685                if (pols[1]) {
2686                        if (IS_ERR(pols[1])) {
2687                                xfrm_pols_put(pols, *num_pols);
2688                                return PTR_ERR(pols[1]);
2689                        }
2690                        (*num_pols)++;
2691                        (*num_xfrms) += pols[1]->xfrm_nr;
2692                }
2693        }
2694#endif
2695        for (i = 0; i < *num_pols; i++) {
2696                if (pols[i]->action != XFRM_POLICY_ALLOW) {
2697                        *num_xfrms = -1;
2698                        break;
2699                }
2700        }
2701
2702        return 0;
2703
2704}
2705
2706static struct xfrm_dst *
2707xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
2708                               const struct flowi *fl, u16 family,
2709                               struct dst_entry *dst_orig)
2710{
2711        struct net *net = xp_net(pols[0]);
2712        struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
2713        struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
2714        struct xfrm_dst *xdst;
2715        struct dst_entry *dst;
2716        int err;
2717
2718        /* Try to instantiate a bundle */
2719        err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
2720        if (err <= 0) {
2721                if (err == 0)
2722                        return NULL;
2723
2724                if (err != -EAGAIN)
2725                        XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
2726                return ERR_PTR(err);
2727        }
2728
2729        dst = xfrm_bundle_create(pols[0], xfrm, bundle, err, fl, dst_orig);
2730        if (IS_ERR(dst)) {
2731                XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
2732                return ERR_CAST(dst);
2733        }
2734
2735        xdst = (struct xfrm_dst *)dst;
2736        xdst->num_xfrms = err;
2737        xdst->num_pols = num_pols;
2738        memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2739        xdst->policy_genid = atomic_read(&pols[0]->genid);
2740
2741        return xdst;
2742}
2743
2744static void xfrm_policy_queue_process(struct timer_list *t)
2745{
2746        struct sk_buff *skb;
2747        struct sock *sk;
2748        struct dst_entry *dst;
2749        struct xfrm_policy *pol = from_timer(pol, t, polq.hold_timer);
2750        struct net *net = xp_net(pol);
2751        struct xfrm_policy_queue *pq = &pol->polq;
2752        struct flowi fl;
2753        struct sk_buff_head list;
2754        __u32 skb_mark;
2755
2756        spin_lock(&pq->hold_queue.lock);
2757        skb = skb_peek(&pq->hold_queue);
2758        if (!skb) {
2759                spin_unlock(&pq->hold_queue.lock);
2760                goto out;
2761        }
2762        dst = skb_dst(skb);
2763        sk = skb->sk;
2764
2765        /* Fixup the mark to support VTI. */
2766        skb_mark = skb->mark;
2767        skb->mark = pol->mark.v;
2768        xfrm_decode_session(skb, &fl, dst->ops->family);
2769        skb->mark = skb_mark;
2770        spin_unlock(&pq->hold_queue.lock);
2771
2772        dst_hold(xfrm_dst_path(dst));
2773        dst = xfrm_lookup(net, xfrm_dst_path(dst), &fl, sk, XFRM_LOOKUP_QUEUE);
2774        if (IS_ERR(dst))
2775                goto purge_queue;
2776
2777        if (dst->flags & DST_XFRM_QUEUE) {
2778                dst_release(dst);
2779
2780                if (pq->timeout >= XFRM_QUEUE_TMO_MAX)
2781                        goto purge_queue;
2782
2783                pq->timeout = pq->timeout << 1;
2784                if (!mod_timer(&pq->hold_timer, jiffies + pq->timeout))
2785                        xfrm_pol_hold(pol);
2786                goto out;
2787        }
2788
2789        dst_release(dst);
2790
2791        __skb_queue_head_init(&list);
2792
2793        spin_lock(&pq->hold_queue.lock);
2794        pq->timeout = 0;
2795        skb_queue_splice_init(&pq->hold_queue, &list);
2796        spin_unlock(&pq->hold_queue.lock);
2797
2798        while (!skb_queue_empty(&list)) {
2799                skb = __skb_dequeue(&list);
2800
2801                /* Fixup the mark to support VTI. */
2802                skb_mark = skb->mark;
2803                skb->mark = pol->mark.v;
2804                xfrm_decode_session(skb, &fl, skb_dst(skb)->ops->family);
2805                skb->mark = skb_mark;
2806
2807                dst_hold(xfrm_dst_path(skb_dst(skb)));
2808                dst = xfrm_lookup(net, xfrm_dst_path(skb_dst(skb)), &fl, skb->sk, 0);
2809                if (IS_ERR(dst)) {
2810                        kfree_skb(skb);
2811                        continue;
2812                }
2813
2814                nf_reset_ct(skb);
2815                skb_dst_drop(skb);
2816                skb_dst_set(skb, dst);
2817
2818                dst_output(net, skb->sk, skb);
2819        }
2820
2821out:
2822        xfrm_pol_put(pol);
2823        return;
2824
2825purge_queue:
2826        pq->timeout = 0;
2827        skb_queue_purge(&pq->hold_queue);
2828        xfrm_pol_put(pol);
2829}
2830
2831static int xdst_queue_output(struct net *net, struct sock *sk, struct sk_buff *skb)
2832{
2833        unsigned long sched_next;
2834        struct dst_entry *dst = skb_dst(skb);
2835        struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
2836        struct xfrm_policy *pol = xdst->pols[0];
2837        struct xfrm_policy_queue *pq = &pol->polq;
2838
2839        if (unlikely(skb_fclone_busy(sk, skb))) {
2840                kfree_skb(skb);
2841                return 0;
2842        }
2843
2844        if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) {
2845                kfree_skb(skb);
2846                return -EAGAIN;
2847        }
2848
2849        skb_dst_force(skb);
2850
2851        spin_lock_bh(&pq->hold_queue.lock);
2852
2853        if (!pq->timeout)
2854                pq->timeout = XFRM_QUEUE_TMO_MIN;
2855
2856        sched_next = jiffies + pq->timeout;
2857
2858        if (del_timer(&pq->hold_timer)) {
2859                if (time_before(pq->hold_timer.expires, sched_next))
2860                        sched_next = pq->hold_timer.expires;
2861                xfrm_pol_put(pol);
2862        }
2863
2864        __skb_queue_tail(&pq->hold_queue, skb);
2865        if (!mod_timer(&pq->hold_timer, sched_next))
2866                xfrm_pol_hold(pol);
2867
2868        spin_unlock_bh(&pq->hold_queue.lock);
2869
2870        return 0;
2871}
2872
2873static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net,
2874                                                 struct xfrm_flo *xflo,
2875                                                 const struct flowi *fl,
2876                                                 int num_xfrms,
2877                                                 u16 family)
2878{
2879        int err;
2880        struct net_device *dev;
2881        struct dst_entry *dst;
2882        struct dst_entry *dst1;
2883        struct xfrm_dst *xdst;
2884
2885        xdst = xfrm_alloc_dst(net, family);
2886        if (IS_ERR(xdst))
2887                return xdst;
2888
2889        if (!(xflo->flags & XFRM_LOOKUP_QUEUE) ||
2890            net->xfrm.sysctl_larval_drop ||
2891            num_xfrms <= 0)
2892                return xdst;
2893
2894        dst = xflo->dst_orig;
2895        dst1 = &xdst->u.dst;
2896        dst_hold(dst);
2897        xdst->route = dst;
2898
2899        dst_copy_metrics(dst1, dst);
2900
2901        dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2902        dst1->flags |= DST_XFRM_QUEUE;
2903        dst1->lastuse = jiffies;
2904
2905        dst1->input = dst_discard;
2906        dst1->output = xdst_queue_output;
2907
2908        dst_hold(dst);
2909        xfrm_dst_set_child(xdst, dst);
2910        xdst->path = dst;
2911
2912        xfrm_init_path((struct xfrm_dst *)dst1, dst, 0);
2913
2914        err = -ENODEV;
2915        dev = dst->dev;
2916        if (!dev)
2917                goto free_dst;
2918
2919        err = xfrm_fill_dst(xdst, dev, fl);
2920        if (err)
2921                goto free_dst;
2922
2923out:
2924        return xdst;
2925
2926free_dst:
2927        dst_release(dst1);
2928        xdst = ERR_PTR(err);
2929        goto out;
2930}
2931
2932static struct xfrm_dst *xfrm_bundle_lookup(struct net *net,
2933                                           const struct flowi *fl,
2934                                           u16 family, u8 dir,
2935                                           struct xfrm_flo *xflo, u32 if_id)
2936{
2937        struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2938        int num_pols = 0, num_xfrms = 0, err;
2939        struct xfrm_dst *xdst;
2940
2941        /* Resolve policies to use if we couldn't get them from
2942         * previous cache entry */
2943        num_pols = 1;
2944        pols[0] = xfrm_policy_lookup(net, fl, family, dir, if_id);
2945        err = xfrm_expand_policies(fl, family, pols,
2946                                           &num_pols, &num_xfrms);
2947        if (err < 0)
2948                goto inc_error;
2949        if (num_pols == 0)
2950                return NULL;
2951        if (num_xfrms <= 0)
2952                goto make_dummy_bundle;
2953
2954        xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
2955                                              xflo->dst_orig);
2956        if (IS_ERR(xdst)) {
2957                err = PTR_ERR(xdst);
2958                if (err == -EREMOTE) {
2959                        xfrm_pols_put(pols, num_pols);
2960                        return NULL;
2961                }
2962
2963                if (err != -EAGAIN)
2964                        goto error;
2965                goto make_dummy_bundle;
2966        } else if (xdst == NULL) {
2967                num_xfrms = 0;
2968                goto make_dummy_bundle;
2969        }
2970
2971        return xdst;
2972
2973make_dummy_bundle:
2974        /* We found policies, but there's no bundles to instantiate:
2975         * either because the policy blocks, has no transformations or
2976         * we could not build template (no xfrm_states).*/
2977        xdst = xfrm_create_dummy_bundle(net, xflo, fl, num_xfrms, family);
2978        if (IS_ERR(xdst)) {
2979                xfrm_pols_put(pols, num_pols);
2980                return ERR_CAST(xdst);
2981        }
2982        xdst->num_pols = num_pols;
2983        xdst->num_xfrms = num_xfrms;
2984        memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2985
2986        return xdst;
2987
2988inc_error:
2989        XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
2990error:
2991        xfrm_pols_put(pols, num_pols);
2992        return ERR_PTR(err);
2993}
2994
2995static struct dst_entry *make_blackhole(struct net *net, u16 family,
2996                                        struct dst_entry *dst_orig)
2997{
2998        const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2999        struct dst_entry *ret;
3000
3001        if (!afinfo) {
3002                dst_release(dst_orig);
3003                return ERR_PTR(-EINVAL);
3004        } else {
3005                ret = afinfo->blackhole_route(net, dst_orig);
3006        }
3007        rcu_read_unlock();
3008
3009        return ret;
3010}
3011
3012/* Finds/creates a bundle for given flow and if_id
3013 *
3014 * At the moment we eat a raw IP route. Mostly to speed up lookups
3015 * on interfaces with disabled IPsec.
3016 *
3017 * xfrm_lookup uses an if_id of 0 by default, and is provided for
3018 * compatibility
3019 */
3020struct dst_entry *xfrm_lookup_with_ifid(struct net *net,
3021                                        struct dst_entry *dst_orig,
3022                                        const struct flowi *fl,
3023                                        const struct sock *sk,
3024                                        int flags, u32 if_id)
3025{
3026        struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
3027        struct xfrm_dst *xdst;
3028        struct dst_entry *dst, *route;
3029        u16 family = dst_orig->ops->family;
3030        u8 dir = XFRM_POLICY_OUT;
3031        int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
3032
3033        dst = NULL;
3034        xdst = NULL;
3035        route = NULL;
3036
3037        sk = sk_const_to_full_sk(sk);
3038        if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
3039                num_pols = 1;
3040                pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, family,
3041                                                if_id);
3042                err = xfrm_expand_policies(fl, family, pols,
3043                                           &num_pols, &num_xfrms);
3044                if (err < 0)
3045                        goto dropdst;
3046
3047                if (num_pols) {
3048                        if (num_xfrms <= 0) {
3049                                drop_pols = num_pols;
3050                                goto no_transform;
3051                        }
3052
3053                        xdst = xfrm_resolve_and_create_bundle(
3054                                        pols, num_pols, fl,
3055                                        family, dst_orig);
3056
3057                        if (IS_ERR(xdst)) {
3058                                xfrm_pols_put(pols, num_pols);
3059                                err = PTR_ERR(xdst);
3060                                if (err == -EREMOTE)
3061                                        goto nopol;
3062
3063                                goto dropdst;
3064                        } else if (xdst == NULL) {
3065                                num_xfrms = 0;
3066                                drop_pols = num_pols;
3067                                goto no_transform;
3068                        }
3069
3070                        route = xdst->route;
3071                }
3072        }
3073
3074        if (xdst == NULL) {
3075                struct xfrm_flo xflo;
3076
3077                xflo.dst_orig = dst_orig;
3078                xflo.flags = flags;
3079
3080                /* To accelerate a bit...  */
3081                if ((dst_orig->flags & DST_NOXFRM) ||
3082                    !net->xfrm.policy_count[XFRM_POLICY_OUT])
3083                        goto nopol;
3084
3085                xdst = xfrm_bundle_lookup(net, fl, family, dir, &xflo, if_id);
3086                if (xdst == NULL)
3087                        goto nopol;
3088                if (IS_ERR(xdst)) {
3089                        err = PTR_ERR(xdst);
3090                        goto dropdst;
3091                }
3092
3093                num_pols = xdst->num_pols;
3094                num_xfrms = xdst->num_xfrms;
3095                memcpy(pols, xdst->pols, sizeof(struct xfrm_policy *) * num_pols);
3096                route = xdst->route;
3097        }
3098
3099        dst = &xdst->u.dst;
3100        if (route == NULL && num_xfrms > 0) {
3101                /* The only case when xfrm_bundle_lookup() returns a
3102                 * bundle with null route, is when the template could
3103                 * not be resolved. It means policies are there, but
3104                 * bundle could not be created, since we don't yet
3105                 * have the xfrm_state's. We need to wait for KM to
3106                 * negotiate new SA's or bail out with error.*/
3107                if (net->xfrm.sysctl_larval_drop) {
3108                        XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
3109                        err = -EREMOTE;
3110                        goto error;
3111                }
3112
3113                err = -EAGAIN;
3114
3115                XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
3116                goto error;
3117        }
3118
3119no_transform:
3120        if (num_pols == 0)
3121                goto nopol;
3122
3123        if ((flags & XFRM_LOOKUP_ICMP) &&
3124            !(pols[0]->flags & XFRM_POLICY_ICMP)) {
3125                err = -ENOENT;
3126                goto error;
3127        }
3128
3129        for (i = 0; i < num_pols; i++)
3130                pols[i]->curlft.use_time = ktime_get_real_seconds();
3131
3132        if (num_xfrms < 0) {
3133                /* Prohibit the flow */
3134                XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
3135                err = -EPERM;
3136                goto error;
3137        } else if (num_xfrms > 0) {
3138                /* Flow transformed */
3139                dst_release(dst_orig);
3140        } else {
3141                /* Flow passes untransformed */
3142                dst_release(dst);
3143                dst = dst_orig;
3144        }
3145ok:
3146        xfrm_pols_put(pols, drop_pols);
3147        if (dst && dst->xfrm &&
3148            dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
3149                dst->flags |= DST_XFRM_TUNNEL;
3150        return dst;
3151
3152nopol:
3153        if (!(flags & XFRM_LOOKUP_ICMP)) {
3154                dst = dst_orig;
3155                goto ok;
3156        }
3157        err = -ENOENT;
3158error:
3159        dst_release(dst);
3160dropdst:
3161        if (!(flags & XFRM_LOOKUP_KEEP_DST_REF))
3162                dst_release(dst_orig);
3163        xfrm_pols_put(pols, drop_pols);
3164        return ERR_PTR(err);
3165}
3166EXPORT_SYMBOL(xfrm_lookup_with_ifid);
3167
3168/* Main function: finds/creates a bundle for given flow.
3169 *
3170 * At the moment we eat a raw IP route. Mostly to speed up lookups
3171 * on interfaces with disabled IPsec.
3172 */
3173struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
3174                              const struct flowi *fl, const struct sock *sk,
3175                              int flags)
3176{
3177        return xfrm_lookup_with_ifid(net, dst_orig, fl, sk, flags, 0);
3178}
3179EXPORT_SYMBOL(xfrm_lookup);
3180
3181/* Callers of xfrm_lookup_route() must ensure a call to dst_output().
3182 * Otherwise we may send out blackholed packets.
3183 */
3184struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
3185                                    const struct flowi *fl,
3186                                    const struct sock *sk, int flags)
3187{
3188        struct dst_entry *dst = xfrm_lookup(net, dst_orig, fl, sk,
3189                                            flags | XFRM_LOOKUP_QUEUE |
3190                                            XFRM_LOOKUP_KEEP_DST_REF);
3191
3192        if (PTR_ERR(dst) == -EREMOTE)
3193                return make_blackhole(net, dst_orig->ops->family, dst_orig);
3194
3195        if (IS_ERR(dst))
3196                dst_release(dst_orig);
3197
3198        return dst;
3199}
3200EXPORT_SYMBOL(xfrm_lookup_route);
3201
3202static inline int
3203xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl)
3204{
3205        struct sec_path *sp = skb_sec_path(skb);
3206        struct xfrm_state *x;
3207
3208        if (!sp || idx < 0 || idx >= sp->len)
3209                return 0;
3210        x = sp->xvec[idx];
3211        if (!x->type->reject)
3212                return 0;
3213        return x->type->reject(x, skb, fl);
3214}
3215
3216/* When skb is transformed back to its "native" form, we have to
3217 * check policy restrictions. At the moment we make this in maximally
3218 * stupid way. Shame on me. :-) Of course, connected sockets must
3219 * have policy cached at them.
3220 */
3221
3222static inline int
3223xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x,
3224              unsigned short family)
3225{
3226        if (xfrm_state_kern(x))
3227                return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
3228        return  x->id.proto == tmpl->id.proto &&
3229                (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
3230                (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
3231                x->props.mode == tmpl->mode &&
3232                (tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
3233                 !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
3234                !(x->props.mode != XFRM_MODE_TRANSPORT &&
3235                  xfrm_state_addr_cmp(tmpl, x, family));
3236}
3237
3238/*
3239 * 0 or more than 0 is returned when validation is succeeded (either bypass
3240 * because of optional transport mode, or next index of the mathced secpath
3241 * state with the template.
3242 * -1 is returned when no matching template is found.
3243 * Otherwise "-2 - errored_index" is returned.
3244 */
3245static inline int
3246xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start,
3247               unsigned short family)
3248{
3249        int idx = start;
3250
3251        if (tmpl->optional) {
3252                if (tmpl->mode == XFRM_MODE_TRANSPORT)
3253                        return start;
3254        } else
3255                start = -1;
3256        for (; idx < sp->len; idx++) {
3257                if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
3258                        return ++idx;
3259                if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
3260                        if (start == -1)
3261                                start = -2-idx;
3262                        break;
3263                }
3264        }
3265        return start;
3266}
3267
3268static void
3269decode_session4(struct sk_buff *skb, struct flowi *fl, bool reverse)
3270{
3271        const struct iphdr *iph = ip_hdr(skb);
3272        int ihl = iph->ihl;
3273        u8 *xprth = skb_network_header(skb) + ihl * 4;
3274        struct flowi4 *fl4 = &fl->u.ip4;
3275        int oif = 0;
3276
3277        if (skb_dst(skb) && skb_dst(skb)->dev)
3278                oif = skb_dst(skb)->dev->ifindex;
3279
3280        memset(fl4, 0, sizeof(struct flowi4));
3281        fl4->flowi4_mark = skb->mark;
3282        fl4->flowi4_oif = reverse ? skb->skb_iif : oif;
3283
3284        fl4->flowi4_proto = iph->protocol;
3285        fl4->daddr = reverse ? iph->saddr : iph->daddr;
3286        fl4->saddr = reverse ? iph->daddr : iph->saddr;
3287        fl4->flowi4_tos = iph->tos;
3288
3289        if (!ip_is_fragment(iph)) {
3290                switch (iph->protocol) {
3291                case IPPROTO_UDP:
3292                case IPPROTO_UDPLITE:
3293                case IPPROTO_TCP:
3294                case IPPROTO_SCTP:
3295                case IPPROTO_DCCP:
3296                        if (xprth + 4 < skb->data ||
3297                            pskb_may_pull(skb, xprth + 4 - skb->data)) {
3298                                __be16 *ports;
3299
3300                                xprth = skb_network_header(skb) + ihl * 4;
3301                                ports = (__be16 *)xprth;
3302
3303                                fl4->fl4_sport = ports[!!reverse];
3304                                fl4->fl4_dport = ports[!reverse];
3305                        }
3306                        break;
3307                case IPPROTO_ICMP:
3308                        if (xprth + 2 < skb->data ||
3309                            pskb_may_pull(skb, xprth + 2 - skb->data)) {
3310                                u8 *icmp;
3311
3312                                xprth = skb_network_header(skb) + ihl * 4;
3313                                icmp = xprth;
3314
3315                                fl4->fl4_icmp_type = icmp[0];
3316                                fl4->fl4_icmp_code = icmp[1];
3317                        }
3318                        break;
3319                case IPPROTO_ESP:
3320                        if (xprth + 4 < skb->data ||
3321                            pskb_may_pull(skb, xprth + 4 - skb->data)) {
3322                                __be32 *ehdr;
3323
3324                                xprth = skb_network_header(skb) + ihl * 4;
3325                                ehdr = (__be32 *)xprth;
3326
3327                                fl4->fl4_ipsec_spi = ehdr[0];
3328                        }
3329                        break;
3330                case IPPROTO_AH:
3331                        if (xprth + 8 < skb->data ||
3332                            pskb_may_pull(skb, xprth + 8 - skb->data)) {
3333                                __be32 *ah_hdr;
3334
3335                                xprth = skb_network_header(skb) + ihl * 4;
3336                                ah_hdr = (__be32 *)xprth;
3337
3338                                fl4->fl4_ipsec_spi = ah_hdr[1];
3339                        }
3340                        break;
3341                case IPPROTO_COMP:
3342                        if (xprth + 4 < skb->data ||
3343                            pskb_may_pull(skb, xprth + 4 - skb->data)) {
3344                                __be16 *ipcomp_hdr;
3345
3346                                xprth = skb_network_header(skb) + ihl * 4;
3347                                ipcomp_hdr = (__be16 *)xprth;
3348
3349                                fl4->fl4_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
3350                        }
3351                        break;
3352                case IPPROTO_GRE:
3353                        if (xprth + 12 < skb->data ||
3354                            pskb_may_pull(skb, xprth + 12 - skb->data)) {
3355                                __be16 *greflags;
3356                                __be32 *gre_hdr;
3357
3358                                xprth = skb_network_header(skb) + ihl * 4;
3359                                greflags = (__be16 *)xprth;
3360                                gre_hdr = (__be32 *)xprth;
3361
3362                                if (greflags[0] & GRE_KEY) {
3363                                        if (greflags[0] & GRE_CSUM)
3364                                                gre_hdr++;
3365                                        fl4->fl4_gre_key = gre_hdr[1];
3366                                }
3367                        }
3368                        break;
3369                default:
3370                        fl4->fl4_ipsec_spi = 0;
3371                        break;
3372                }
3373        }
3374}
3375
3376#if IS_ENABLED(CONFIG_IPV6)
3377static void
3378decode_session6(struct sk_buff *skb, struct flowi *fl, bool reverse)
3379{
3380        struct flowi6 *fl6 = &fl->u.ip6;
3381        int onlyproto = 0;
3382        const struct ipv6hdr *hdr = ipv6_hdr(skb);
3383        u32 offset = sizeof(*hdr);
3384        struct ipv6_opt_hdr *exthdr;
3385        const unsigned char *nh = skb_network_header(skb);
3386        u16 nhoff = IP6CB(skb)->nhoff;
3387        int oif = 0;
3388        u8 nexthdr;
3389
3390        if (!nhoff)
3391                nhoff = offsetof(struct ipv6hdr, nexthdr);
3392
3393        nexthdr = nh[nhoff];
3394
3395        if (skb_dst(skb) && skb_dst(skb)->dev)
3396                oif = skb_dst(skb)->dev->ifindex;
3397
3398        memset(fl6, 0, sizeof(struct flowi6));
3399        fl6->flowi6_mark = skb->mark;
3400        fl6->flowi6_oif = reverse ? skb->skb_iif : oif;
3401
3402        fl6->daddr = reverse ? hdr->saddr : hdr->daddr;
3403        fl6->saddr = reverse ? hdr->daddr : hdr->saddr;
3404
3405        while (nh + offset + sizeof(*exthdr) < skb->data ||
3406               pskb_may_pull(skb, nh + offset + sizeof(*exthdr) - skb->data)) {
3407                nh = skb_network_header(skb);
3408                exthdr = (struct ipv6_opt_hdr *)(nh + offset);
3409
3410                switch (nexthdr) {
3411                case NEXTHDR_FRAGMENT:
3412                        onlyproto = 1;
3413                        fallthrough;
3414                case NEXTHDR_ROUTING:
3415                case NEXTHDR_HOP:
3416                case NEXTHDR_DEST:
3417                        offset += ipv6_optlen(exthdr);
3418                        nexthdr = exthdr->nexthdr;
3419                        exthdr = (struct ipv6_opt_hdr *)(nh + offset);
3420                        break;
3421                case IPPROTO_UDP:
3422                case IPPROTO_UDPLITE:
3423                case IPPROTO_TCP:
3424                case IPPROTO_SCTP:
3425                case IPPROTO_DCCP:
3426                        if (!onlyproto && (nh + offset + 4 < skb->data ||
3427                             pskb_may_pull(skb, nh + offset + 4 - skb->data))) {
3428                                __be16 *ports;
3429
3430                                nh = skb_network_header(skb);
3431                                ports = (__be16 *)(nh + offset);
3432                                fl6->fl6_sport = ports[!!reverse];
3433                                fl6->fl6_dport = ports[!reverse];
3434                        }
3435                        fl6->flowi6_proto = nexthdr;
3436                        return;
3437                case IPPROTO_ICMPV6:
3438                        if (!onlyproto && (nh + offset + 2 < skb->data ||
3439                            pskb_may_pull(skb, nh + offset + 2 - skb->data))) {
3440                                u8 *icmp;
3441
3442                                nh = skb_network_header(skb);
3443                                icmp = (u8 *)(nh + offset);
3444                                fl6->fl6_icmp_type = icmp[0];
3445                                fl6->fl6_icmp_code = icmp[1];
3446                        }
3447                        fl6->flowi6_proto = nexthdr;
3448                        return;
3449#if IS_ENABLED(CONFIG_IPV6_MIP6)
3450                case IPPROTO_MH:
3451                        offset += ipv6_optlen(exthdr);
3452                        if (!onlyproto && (nh + offset + 3 < skb->data ||
3453                            pskb_may_pull(skb, nh + offset + 3 - skb->data))) {
3454                                struct ip6_mh *mh;
3455
3456                                nh = skb_network_header(skb);
3457                                mh = (struct ip6_mh *)(nh + offset);
3458                                fl6->fl6_mh_type = mh->ip6mh_type;
3459                        }
3460                        fl6->flowi6_proto = nexthdr;
3461                        return;
3462#endif
3463                /* XXX Why are there these headers? */
3464                case IPPROTO_AH:
3465                case IPPROTO_ESP:
3466                case IPPROTO_COMP:
3467                default:
3468                        fl6->fl6_ipsec_spi = 0;
3469                        fl6->flowi6_proto = nexthdr;
3470                        return;
3471                }
3472        }
3473}
3474#endif
3475
3476int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
3477                          unsigned int family, int reverse)
3478{
3479        switch (family) {
3480        case AF_INET:
3481                decode_session4(skb, fl, reverse);
3482                break;
3483#if IS_ENABLED(CONFIG_IPV6)
3484        case AF_INET6:
3485                decode_session6(skb, fl, reverse);
3486                break;
3487#endif
3488        default:
3489                return -EAFNOSUPPORT;
3490        }
3491
3492        return security_xfrm_decode_session(skb, &fl->flowi_secid);
3493}
3494EXPORT_SYMBOL(__xfrm_decode_session);
3495
3496static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
3497{
3498        for (; k < sp->len; k++) {
3499                if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
3500                        *idxp = k;
3501                        return 1;
3502                }
3503        }
3504
3505        return 0;
3506}
3507
3508int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
3509                        unsigned short family)
3510{
3511        struct net *net = dev_net(skb->dev);
3512        struct xfrm_policy *pol;
3513        struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
3514        int npols = 0;
3515        int xfrm_nr;
3516        int pi;
3517        int reverse;
3518        struct flowi fl;
3519        int xerr_idx = -1;
3520        const struct xfrm_if_cb *ifcb;
3521        struct sec_path *sp;
3522        struct xfrm_if *xi;
3523        u32 if_id = 0;
3524
3525        rcu_read_lock();
3526        ifcb = xfrm_if_get_cb();
3527
3528        if (ifcb) {
3529                xi = ifcb->decode_session(skb, family);
3530                if (xi) {
3531                        if_id = xi->p.if_id;
3532                        net = xi->net;
3533                }
3534        }
3535        rcu_read_unlock();
3536
3537        reverse = dir & ~XFRM_POLICY_MASK;
3538        dir &= XFRM_POLICY_MASK;
3539
3540        if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) {
3541                XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
3542                return 0;
3543        }
3544
3545        nf_nat_decode_session(skb, &fl, family);
3546
3547        /* First, check used SA against their selectors. */
3548        sp = skb_sec_path(skb);
3549        if (sp) {
3550                int i;
3551
3552                for (i = sp->len - 1; i >= 0; i--) {
3553                        struct xfrm_state *x = sp->xvec[i];
3554                        if (!xfrm_selector_match(&x->sel, &fl, family)) {
3555                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
3556                                return 0;
3557                        }
3558                }
3559        }
3560
3561        pol = NULL;
3562        sk = sk_to_full_sk(sk);
3563        if (sk && sk->sk_policy[dir]) {
3564                pol = xfrm_sk_policy_lookup(sk, dir, &fl, family, if_id);
3565                if (IS_ERR(pol)) {
3566                        XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3567                        return 0;
3568                }
3569        }
3570
3571        if (!pol)
3572                pol = xfrm_policy_lookup(net, &fl, family, dir, if_id);
3573
3574        if (IS_ERR(pol)) {
3575                XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3576                return 0;
3577        }
3578
3579        if (!pol) {
3580                if (sp && secpath_has_nontransport(sp, 0, &xerr_idx)) {
3581                        xfrm_secpath_reject(xerr_idx, skb, &fl);
3582                        XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
3583                        return 0;
3584                }
3585                return 1;
3586        }
3587
3588        pol->curlft.use_time = ktime_get_real_seconds();
3589
3590        pols[0] = pol;
3591        npols++;
3592#ifdef CONFIG_XFRM_SUB_POLICY
3593        if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
3594                pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
3595                                                    &fl, family,
3596                                                    XFRM_POLICY_IN, if_id);
3597                if (pols[1]) {
3598                        if (IS_ERR(pols[1])) {
3599                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3600                                return 0;
3601                        }
3602                        pols[1]->curlft.use_time = ktime_get_real_seconds();
3603                        npols++;
3604                }
3605        }
3606#endif
3607
3608        if (pol->action == XFRM_POLICY_ALLOW) {
3609                static struct sec_path dummy;
3610                struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
3611                struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
3612                struct xfrm_tmpl **tpp = tp;
3613                int ti = 0;
3614                int i, k;
3615
3616                sp = skb_sec_path(skb);
3617                if (!sp)
3618                        sp = &dummy;
3619
3620                for (pi = 0; pi < npols; pi++) {
3621                        if (pols[pi] != pol &&
3622                            pols[pi]->action != XFRM_POLICY_ALLOW) {
3623                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
3624                                goto reject;
3625                        }
3626                        if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
3627                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
3628                                goto reject_error;
3629                        }
3630                        for (i = 0; i < pols[pi]->xfrm_nr; i++)
3631                                tpp[ti++] = &pols[pi]->xfrm_vec[i];
3632                }
3633                xfrm_nr = ti;
3634                if (npols > 1) {
3635                        xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
3636                        tpp = stp;
3637                }
3638
3639                /* For each tunnel xfrm, find the first matching tmpl.
3640                 * For each tmpl before that, find corresponding xfrm.
3641                 * Order is _important_. Later we will implement
3642                 * some barriers, but at the moment barriers
3643                 * are implied between each two transformations.
3644                 */
3645                for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
3646                        k = xfrm_policy_ok(tpp[i], sp, k, family);
3647                        if (k < 0) {
3648                                if (k < -1)
3649                                        /* "-2 - errored_index" returned */
3650                                        xerr_idx = -(2+k);
3651                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
3652                                goto reject;
3653                        }
3654                }
3655
3656                if (secpath_has_nontransport(sp, k, &xerr_idx)) {
3657                        XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
3658                        goto reject;
3659                }
3660
3661                xfrm_pols_put(pols, npols);
3662                return 1;
3663        }
3664        XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
3665
3666reject:
3667        xfrm_secpath_reject(xerr_idx, skb, &fl);
3668reject_error:
3669        xfrm_pols_put(pols, npols);
3670        return 0;
3671}
3672EXPORT_SYMBOL(__xfrm_policy_check);
3673
3674int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
3675{
3676        struct net *net = dev_net(skb->dev);
3677        struct flowi fl;
3678        struct dst_entry *dst;
3679        int res = 1;
3680
3681        if (xfrm_decode_session(skb, &fl, family) < 0) {
3682                XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
3683                return 0;
3684        }
3685
3686        skb_dst_force(skb);
3687        if (!skb_dst(skb)) {
3688                XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
3689                return 0;
3690        }
3691
3692        dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE);
3693        if (IS_ERR(dst)) {
3694                res = 0;
3695                dst = NULL;
3696        }
3697        skb_dst_set(skb, dst);
3698        return res;
3699}
3700EXPORT_SYMBOL(__xfrm_route_forward);
3701
3702/* Optimize later using cookies and generation ids. */
3703
3704static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
3705{
3706        /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
3707         * to DST_OBSOLETE_FORCE_CHK to force all XFRM destinations to
3708         * get validated by dst_ops->check on every use.  We do this
3709         * because when a normal route referenced by an XFRM dst is
3710         * obsoleted we do not go looking around for all parent
3711         * referencing XFRM dsts so that we can invalidate them.  It
3712         * is just too much work.  Instead we make the checks here on
3713         * every use.  For example:
3714         *
3715         *      XFRM dst A --> IPv4 dst X
3716         *
3717         * X is the "xdst->route" of A (X is also the "dst->path" of A
3718         * in this example).  If X is marked obsolete, "A" will not
3719         * notice.  That's what we are validating here via the
3720         * stale_bundle() check.
3721         *
3722         * When a dst is removed from the fib tree, DST_OBSOLETE_DEAD will
3723         * be marked on it.
3724         * This will force stale_bundle() to fail on any xdst bundle with
3725         * this dst linked in it.
3726         */
3727        if (dst->obsolete < 0 && !stale_bundle(dst))
3728                return dst;
3729
3730        return NULL;
3731}
3732
3733static int stale_bundle(struct dst_entry *dst)
3734{
3735        return !xfrm_bundle_ok((struct xfrm_dst *)dst);
3736}
3737
3738void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
3739{
3740        while ((dst = xfrm_dst_child(dst)) && dst->xfrm && dst->dev == dev) {
3741                dst->dev = dev_net(dev)->loopback_dev;
3742                dev_hold(dst->dev);
3743                dev_put(dev);
3744        }
3745}
3746EXPORT_SYMBOL(xfrm_dst_ifdown);
3747
3748static void xfrm_link_failure(struct sk_buff *skb)
3749{
3750        /* Impossible. Such dst must be popped before reaches point of failure. */
3751}
3752
3753static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
3754{
3755        if (dst) {
3756                if (dst->obsolete) {
3757                        dst_release(dst);
3758                        dst = NULL;
3759                }
3760        }
3761        return dst;
3762}
3763
3764static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr)
3765{
3766        while (nr--) {
3767                struct xfrm_dst *xdst = bundle[nr];
3768                u32 pmtu, route_mtu_cached;
3769                struct dst_entry *dst;
3770
3771                dst = &xdst->u.dst;
3772                pmtu = dst_mtu(xfrm_dst_child(dst));
3773                xdst->child_mtu_cached = pmtu;
3774
3775                pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
3776
3777                route_mtu_cached = dst_mtu(xdst->route);
3778                xdst->route_mtu_cached = route_mtu_cached;
3779
3780                if (pmtu > route_mtu_cached)
3781                        pmtu = route_mtu_cached;
3782
3783                dst_metric_set(dst, RTAX_MTU, pmtu);
3784        }
3785}
3786
3787/* Check that the bundle accepts the flow and its components are
3788 * still valid.
3789 */
3790
3791static int xfrm_bundle_ok(struct xfrm_dst *first)
3792{
3793        struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
3794        struct dst_entry *dst = &first->u.dst;
3795        struct xfrm_dst *xdst;
3796        int start_from, nr;
3797        u32 mtu;
3798
3799        if (!dst_check(xfrm_dst_path(dst), ((struct xfrm_dst *)dst)->path_cookie) ||
3800            (dst->dev && !netif_running(dst->dev)))
3801                return 0;
3802
3803        if (dst->flags & DST_XFRM_QUEUE)
3804                return 1;
3805
3806        start_from = nr = 0;
3807        do {
3808                struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
3809
3810                if (dst->xfrm->km.state != XFRM_STATE_VALID)
3811                        return 0;
3812                if (xdst->xfrm_genid != dst->xfrm->genid)
3813                        return 0;
3814                if (xdst->num_pols > 0 &&
3815                    xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
3816                        return 0;
3817
3818                bundle[nr++] = xdst;
3819
3820                mtu = dst_mtu(xfrm_dst_child(dst));
3821                if (xdst->child_mtu_cached != mtu) {
3822                        start_from = nr;
3823                        xdst->child_mtu_cached = mtu;
3824                }
3825
3826                if (!dst_check(xdst->route, xdst->route_cookie))
3827                        return 0;
3828                mtu = dst_mtu(xdst->route);
3829                if (xdst->route_mtu_cached != mtu) {
3830                        start_from = nr;
3831                        xdst->route_mtu_cached = mtu;
3832                }
3833
3834                dst = xfrm_dst_child(dst);
3835        } while (dst->xfrm);
3836
3837        if (likely(!start_from))
3838                return 1;
3839
3840        xdst = bundle[start_from - 1];
3841        mtu = xdst->child_mtu_cached;
3842        while (start_from--) {
3843                dst = &xdst->u.dst;
3844
3845                mtu = xfrm_state_mtu(dst->xfrm, mtu);
3846                if (mtu > xdst->route_mtu_cached)
3847                        mtu = xdst->route_mtu_cached;
3848                dst_metric_set(dst, RTAX_MTU, mtu);
3849                if (!start_from)
3850                        break;
3851
3852                xdst = bundle[start_from - 1];
3853                xdst->child_mtu_cached = mtu;
3854        }
3855
3856        return 1;
3857}
3858
3859static unsigned int xfrm_default_advmss(const struct dst_entry *dst)
3860{
3861        return dst_metric_advmss(xfrm_dst_path(dst));
3862}
3863
3864static unsigned int xfrm_mtu(const struct dst_entry *dst)
3865{
3866        unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
3867
3868        return mtu ? : dst_mtu(xfrm_dst_path(dst));
3869}
3870
3871static const void *xfrm_get_dst_nexthop(const struct dst_entry *dst,
3872                                        const void *daddr)
3873{
3874        while (dst->xfrm) {
3875                const struct xfrm_state *xfrm = dst->xfrm;
3876
3877                dst = xfrm_dst_child(dst);
3878
3879                if (xfrm->props.mode == XFRM_MODE_TRANSPORT)
3880                        continue;
3881                if (xfrm->type->flags & XFRM_TYPE_REMOTE_COADDR)
3882                        daddr = xfrm->coaddr;
3883                else if (!(xfrm->type->flags & XFRM_TYPE_LOCAL_COADDR))
3884                        daddr = &xfrm->id.daddr;
3885        }
3886        return daddr;
3887}
3888
3889static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst,
3890                                           struct sk_buff *skb,
3891                                           const void *daddr)
3892{
3893        const struct dst_entry *path = xfrm_dst_path(dst);
3894
3895        if (!skb)
3896                daddr = xfrm_get_dst_nexthop(dst, daddr);
3897        return path->ops->neigh_lookup(path, skb, daddr);
3898}
3899
3900static void xfrm_confirm_neigh(const struct dst_entry *dst, const void *daddr)
3901{
3902        const struct dst_entry *path = xfrm_dst_path(dst);
3903
3904        daddr = xfrm_get_dst_nexthop(dst, daddr);
3905        path->ops->confirm_neigh(path, daddr);
3906}
3907
3908int xfrm_policy_register_afinfo(const struct xfrm_policy_afinfo *afinfo, int family)
3909{
3910        int err = 0;
3911
3912        if (WARN_ON(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
3913                return -EAFNOSUPPORT;
3914
3915        spin_lock(&xfrm_policy_afinfo_lock);
3916        if (unlikely(xfrm_policy_afinfo[family] != NULL))
3917                err = -EEXIST;
3918        else {
3919                struct dst_ops *dst_ops = afinfo->dst_ops;
3920                if (likely(dst_ops->kmem_cachep == NULL))
3921                        dst_ops->kmem_cachep = xfrm_dst_cache;
3922                if (likely(dst_ops->check == NULL))
3923                        dst_ops->check = xfrm_dst_check;
3924                if (likely(dst_ops->default_advmss == NULL))
3925                        dst_ops->default_advmss = xfrm_default_advmss;
3926                if (likely(dst_ops->mtu == NULL))
3927                        dst_ops->mtu = xfrm_mtu;
3928                if (likely(dst_ops->negative_advice == NULL))
3929                        dst_ops->negative_advice = xfrm_negative_advice;
3930                if (likely(dst_ops->link_failure == NULL))
3931                        dst_ops->link_failure = xfrm_link_failure;
3932                if (likely(dst_ops->neigh_lookup == NULL))
3933                        dst_ops->neigh_lookup = xfrm_neigh_lookup;
3934                if (likely(!dst_ops->confirm_neigh))
3935                        dst_ops->confirm_neigh = xfrm_confirm_neigh;
3936                rcu_assign_pointer(xfrm_policy_afinfo[family], afinfo);
3937        }
3938        spin_unlock(&xfrm_policy_afinfo_lock);
3939
3940        return err;
3941}
3942EXPORT_SYMBOL(xfrm_policy_register_afinfo);
3943
3944void xfrm_policy_unregister_afinfo(const struct xfrm_policy_afinfo *afinfo)
3945{
3946        struct dst_ops *dst_ops = afinfo->dst_ops;
3947        int i;
3948
3949        for (i = 0; i < ARRAY_SIZE(xfrm_policy_afinfo); i++) {
3950                if (xfrm_policy_afinfo[i] != afinfo)
3951                        continue;
3952                RCU_INIT_POINTER(xfrm_policy_afinfo[i], NULL);
3953                break;
3954        }
3955
3956        synchronize_rcu();
3957
3958        dst_ops->kmem_cachep = NULL;
3959        dst_ops->check = NULL;
3960        dst_ops->negative_advice = NULL;
3961        dst_ops->link_failure = NULL;
3962}
3963EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
3964
3965void xfrm_if_register_cb(const struct xfrm_if_cb *ifcb)
3966{
3967        spin_lock(&xfrm_if_cb_lock);
3968        rcu_assign_pointer(xfrm_if_cb, ifcb);
3969        spin_unlock(&xfrm_if_cb_lock);
3970}
3971EXPORT_SYMBOL(xfrm_if_register_cb);
3972
3973void xfrm_if_unregister_cb(void)
3974{
3975        RCU_INIT_POINTER(xfrm_if_cb, NULL);
3976        synchronize_rcu();
3977}
3978EXPORT_SYMBOL(xfrm_if_unregister_cb);
3979
3980#ifdef CONFIG_XFRM_STATISTICS
3981static int __net_init xfrm_statistics_init(struct net *net)
3982{
3983        int rv;
3984        net->mib.xfrm_statistics = alloc_percpu(struct linux_xfrm_mib);
3985        if (!net->mib.xfrm_statistics)
3986                return -ENOMEM;
3987        rv = xfrm_proc_init(net);
3988        if (rv < 0)
3989                free_percpu(net->mib.xfrm_statistics);
3990        return rv;
3991}
3992
3993static void xfrm_statistics_fini(struct net *net)
3994{
3995        xfrm_proc_fini(net);
3996        free_percpu(net->mib.xfrm_statistics);
3997}
3998#else
3999static int __net_init xfrm_statistics_init(struct net *net)
4000{
4001        return 0;
4002}
4003
4004static void xfrm_statistics_fini(struct net *net)
4005{
4006}
4007#endif
4008
4009static int __net_init xfrm_policy_init(struct net *net)
4010{
4011        unsigned int hmask, sz;
4012        int dir, err;
4013
4014        if (net_eq(net, &init_net)) {
4015                xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
4016                                           sizeof(struct xfrm_dst),
4017                                           0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
4018                                           NULL);
4019                err = rhashtable_init(&xfrm_policy_inexact_table,
4020                                      &xfrm_pol_inexact_params);
4021                BUG_ON(err);
4022        }
4023
4024        hmask = 8 - 1;
4025        sz = (hmask+1) * sizeof(struct hlist_head);
4026
4027        net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
4028        if (!net->xfrm.policy_byidx)
4029                goto out_byidx;
4030        net->xfrm.policy_idx_hmask = hmask;
4031
4032        for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
4033                struct xfrm_policy_hash *htab;
4034
4035                net->xfrm.policy_count[dir] = 0;
4036                net->xfrm.policy_count[XFRM_POLICY_MAX + dir] = 0;
4037                INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
4038
4039                htab = &net->xfrm.policy_bydst[dir];
4040                htab->table = xfrm_hash_alloc(sz);
4041                if (!htab->table)
4042                        goto out_bydst;
4043                htab->hmask = hmask;
4044                htab->dbits4 = 32;
4045                htab->sbits4 = 32;
4046                htab->dbits6 = 128;
4047                htab->sbits6 = 128;
4048        }
4049        net->xfrm.policy_hthresh.lbits4 = 32;
4050        net->xfrm.policy_hthresh.rbits4 = 32;
4051        net->xfrm.policy_hthresh.lbits6 = 128;
4052        net->xfrm.policy_hthresh.rbits6 = 128;
4053
4054        seqlock_init(&net->xfrm.policy_hthresh.lock);
4055
4056        INIT_LIST_HEAD(&net->xfrm.policy_all);
4057        INIT_LIST_HEAD(&net->xfrm.inexact_bins);
4058        INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
4059        INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild);
4060        return 0;
4061
4062out_bydst:
4063        for (dir--; dir >= 0; dir--) {
4064                struct xfrm_policy_hash *htab;
4065
4066                htab = &net->xfrm.policy_bydst[dir];
4067                xfrm_hash_free(htab->table, sz);
4068        }
4069        xfrm_hash_free(net->xfrm.policy_byidx, sz);
4070out_byidx:
4071        return -ENOMEM;
4072}
4073
4074static void xfrm_policy_fini(struct net *net)
4075{
4076        struct xfrm_pol_inexact_bin *b, *t;
4077        unsigned int sz;
4078        int dir;
4079
4080        flush_work(&net->xfrm.policy_hash_work);
4081#ifdef CONFIG_XFRM_SUB_POLICY
4082        xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, false);
4083#endif
4084        xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, false);
4085
4086        WARN_ON(!list_empty(&net->xfrm.policy_all));
4087
4088        for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
4089                struct xfrm_policy_hash *htab;
4090
4091                WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
4092
4093                htab = &net->xfrm.policy_bydst[dir];
4094                sz = (htab->hmask + 1) * sizeof(struct hlist_head);
4095                WARN_ON(!hlist_empty(htab->table));
4096                xfrm_hash_free(htab->table, sz);
4097        }
4098
4099        sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
4100        WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
4101        xfrm_hash_free(net->xfrm.policy_byidx, sz);
4102
4103        spin_lock_bh(&net->xfrm.xfrm_policy_lock);
4104        list_for_each_entry_safe(b, t, &net->xfrm.inexact_bins, inexact_bins)
4105                __xfrm_policy_inexact_prune_bin(b, true);
4106        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
4107}
4108
4109static int __net_init xfrm_net_init(struct net *net)
4110{
4111        int rv;
4112
4113        /* Initialize the per-net locks here */
4114        spin_lock_init(&net->xfrm.xfrm_state_lock);
4115        spin_lock_init(&net->xfrm.xfrm_policy_lock);
4116        mutex_init(&net->xfrm.xfrm_cfg_mutex);
4117
4118        rv = xfrm_statistics_init(net);
4119        if (rv < 0)
4120                goto out_statistics;
4121        rv = xfrm_state_init(net);
4122        if (rv < 0)
4123                goto out_state;
4124        rv = xfrm_policy_init(net);
4125        if (rv < 0)
4126                goto out_policy;
4127        rv = xfrm_sysctl_init(net);
4128        if (rv < 0)
4129                goto out_sysctl;
4130
4131        return 0;
4132
4133out_sysctl:
4134        xfrm_policy_fini(net);
4135out_policy:
4136        xfrm_state_fini(net);
4137out_state:
4138        xfrm_statistics_fini(net);
4139out_statistics:
4140        return rv;
4141}
4142
4143static void __net_exit xfrm_net_exit(struct net *net)
4144{
4145        xfrm_sysctl_fini(net);
4146        xfrm_policy_fini(net);
4147        xfrm_state_fini(net);
4148        xfrm_statistics_fini(net);
4149}
4150
4151static struct pernet_operations __net_initdata xfrm_net_ops = {
4152        .init = xfrm_net_init,
4153        .exit = xfrm_net_exit,
4154};
4155
4156void __init xfrm_init(void)
4157{
4158        register_pernet_subsys(&xfrm_net_ops);
4159        xfrm_dev_init();
4160        seqcount_mutex_init(&xfrm_policy_hash_generation, &hash_resize_mutex);
4161        xfrm_input_init();
4162
4163#ifdef CONFIG_XFRM_ESPINTCP
4164        espintcp_init();
4165#endif
4166
4167        RCU_INIT_POINTER(xfrm_if_cb, NULL);
4168        synchronize_rcu();
4169}
4170
4171#ifdef CONFIG_AUDITSYSCALL
4172static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
4173                                         struct audit_buffer *audit_buf)
4174{
4175        struct xfrm_sec_ctx *ctx = xp->security;
4176        struct xfrm_selector *sel = &xp->selector;
4177
4178        if (ctx)
4179                audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
4180                                 ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
4181
4182        switch (sel->family) {
4183        case AF_INET:
4184                audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
4185                if (sel->prefixlen_s != 32)
4186                        audit_log_format(audit_buf, " src_prefixlen=%d",
4187                                         sel->prefixlen_s);
4188                audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
4189                if (sel->prefixlen_d != 32)
4190                        audit_log_format(audit_buf, " dst_prefixlen=%d",
4191                                         sel->prefixlen_d);
4192                break;
4193        case AF_INET6:
4194                audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
4195                if (sel->prefixlen_s != 128)
4196                        audit_log_format(audit_buf, " src_prefixlen=%d",
4197                                         sel->prefixlen_s);
4198                audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
4199                if (sel->prefixlen_d != 128)
4200                        audit_log_format(audit_buf, " dst_prefixlen=%d",
4201                                         sel->prefixlen_d);
4202                break;
4203        }
4204}
4205
4206void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
4207{
4208        struct audit_buffer *audit_buf;
4209
4210        audit_buf = xfrm_audit_start("SPD-add");
4211        if (audit_buf == NULL)
4212                return;
4213        xfrm_audit_helper_usrinfo(task_valid, audit_buf);
4214        audit_log_format(audit_buf, " res=%u", result);
4215        xfrm_audit_common_policyinfo(xp, audit_buf);
4216        audit_log_end(audit_buf);
4217}
4218EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
4219
4220void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
4221                              bool task_valid)
4222{
4223        struct audit_buffer *audit_buf;
4224
4225        audit_buf = xfrm_audit_start("SPD-delete");
4226        if (audit_buf == NULL)
4227                return;
4228        xfrm_audit_helper_usrinfo(task_valid, audit_buf);
4229        audit_log_format(audit_buf, " res=%u", result);
4230        xfrm_audit_common_policyinfo(xp, audit_buf);
4231        audit_log_end(audit_buf);
4232}
4233EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
4234#endif
4235
4236#ifdef CONFIG_XFRM_MIGRATE
4237static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
4238                                        const struct xfrm_selector *sel_tgt)
4239{
4240        if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
4241                if (sel_tgt->family == sel_cmp->family &&
4242                    xfrm_addr_equal(&sel_tgt->daddr, &sel_cmp->daddr,
4243                                    sel_cmp->family) &&
4244                    xfrm_addr_equal(&sel_tgt->saddr, &sel_cmp->saddr,
4245                                    sel_cmp->family) &&
4246                    sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
4247                    sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
4248                        return true;
4249                }
4250        } else {
4251                if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
4252                        return true;
4253                }
4254        }
4255        return false;
4256}
4257
4258static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel,
4259                                                    u8 dir, u8 type, struct net *net)
4260{
4261        struct xfrm_policy *pol, *ret = NULL;
4262        struct hlist_head *chain;
4263        u32 priority = ~0U;
4264
4265        spin_lock_bh(&net->xfrm.xfrm_policy_lock);
4266        chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);
4267        hlist_for_each_entry(pol, chain, bydst) {
4268                if (xfrm_migrate_selector_match(sel, &pol->selector) &&
4269                    pol->type == type) {
4270                        ret = pol;
4271                        priority = ret->priority;
4272                        break;
4273                }
4274        }
4275        chain = &net->xfrm.policy_inexact[dir];
4276        hlist_for_each_entry(pol, chain, bydst_inexact_list) {
4277                if ((pol->priority >= priority) && ret)
4278                        break;
4279
4280                if (xfrm_migrate_selector_match(sel, &pol->selector) &&
4281                    pol->type == type) {
4282                        ret = pol;
4283                        break;
4284                }
4285        }
4286
4287        xfrm_pol_hold(ret);
4288
4289        spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
4290
4291        return ret;
4292}
4293
4294static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
4295{
4296        int match = 0;
4297
4298        if (t->mode == m->mode && t->id.proto == m->proto &&
4299            (m->reqid == 0 || t->reqid == m->reqid)) {
4300                switch (t->mode) {
4301                case XFRM_MODE_TUNNEL:
4302                case XFRM_MODE_BEET:
4303                        if (xfrm_addr_equal(&t->id.daddr, &m->old_daddr,
4304                                            m->old_family) &&
4305                            xfrm_addr_equal(&t->saddr, &m->old_saddr,
4306                                            m->old_family)) {
4307                                match = 1;
4308                        }
4309                        break;
4310                case XFRM_MODE_TRANSPORT:
4311                        /* in case of transport mode, template does not store
4312                           any IP addresses, hence we just compare mode and
4313                           protocol */
4314                        match = 1;
4315                        break;
4316                default:
4317                        break;
4318                }
4319        }
4320        return match;
4321}
4322
4323/* update endpoint address(es) of template(s) */
4324static int xfrm_policy_migrate(struct xfrm_policy *pol,
4325                               struct xfrm_migrate *m, int num_migrate)
4326{
4327        struct xfrm_migrate *mp;
4328        int i, j, n = 0;
4329
4330        write_lock_bh(&pol->lock);
4331        if (unlikely(pol->walk.dead)) {
4332                /* target policy has been deleted */
4333                write_unlock_bh(&pol->lock);
4334                return -ENOENT;
4335        }
4336
4337        for (i = 0; i < pol->xfrm_nr; i++) {
4338                for (j = 0, mp = m; j < num_migrate; j++, mp++) {
4339                        if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
4340                                continue;
4341                        n++;
4342                        if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
4343                            pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
4344                                continue;
4345                        /* update endpoints */
4346                        memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
4347                               sizeof(pol->xfrm_vec[i].id.daddr));
4348                        memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
4349                               sizeof(pol->xfrm_vec[i].saddr));
4350                        pol->xfrm_vec[i].encap_family = mp->new_family;
4351                        /* flush bundles */
4352                        atomic_inc(&pol->genid);
4353                }
4354        }
4355
4356        write_unlock_bh(&pol->lock);
4357
4358        if (!n)
4359                return -ENODATA;
4360
4361        return 0;
4362}
4363
4364static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
4365{
4366        int i, j;
4367
4368        if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
4369                return -EINVAL;
4370
4371        for (i = 0; i < num_migrate; i++) {
4372                if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
4373                    xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
4374                        return -EINVAL;
4375
4376                /* check if there is any duplicated entry */
4377                for (j = i + 1; j < num_migrate; j++) {
4378                        if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
4379                                    sizeof(m[i].old_daddr)) &&
4380                            !memcmp(&m[i].old_saddr, &m[j].old_saddr,
4381                                    sizeof(m[i].old_saddr)) &&
4382                            m[i].proto == m[j].proto &&
4383                            m[i].mode == m[j].mode &&
4384                            m[i].reqid == m[j].reqid &&
4385                            m[i].old_family == m[j].old_family)
4386                                return -EINVAL;
4387                }
4388        }
4389
4390        return 0;
4391}
4392
4393int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
4394                 struct xfrm_migrate *m, int num_migrate,
4395                 struct xfrm_kmaddress *k, struct net *net,
4396                 struct xfrm_encap_tmpl *encap)
4397{
4398        int i, err, nx_cur = 0, nx_new = 0;
4399        struct xfrm_policy *pol = NULL;
4400        struct xfrm_state *x, *xc;
4401        struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
4402        struct xfrm_state *x_new[XFRM_MAX_DEPTH];
4403        struct xfrm_migrate *mp;
4404
4405        /* Stage 0 - sanity checks */
4406        if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
4407                goto out;
4408
4409        if (dir >= XFRM_POLICY_MAX) {
4410                err = -EINVAL;
4411                goto out;
4412        }
4413
4414        /* Stage 1 - find policy */
4415        if ((pol = xfrm_migrate_policy_find(sel, dir, type, net)) == NULL) {
4416                err = -ENOENT;
4417                goto out;
4418        }
4419
4420        /* Stage 2 - find and update state(s) */
4421        for (i = 0, mp = m; i < num_migrate; i++, mp++) {
4422                if ((x = xfrm_migrate_state_find(mp, net))) {
4423                        x_cur[nx_cur] = x;
4424                        nx_cur++;
4425                        xc = xfrm_state_migrate(x, mp, encap);
4426                        if (xc) {
4427                                x_new[nx_new] = xc;
4428                                nx_new++;
4429                        } else {
4430                                err = -ENODATA;
4431                                goto restore_state;
4432                        }
4433                }
4434        }
4435
4436        /* Stage 3 - update policy */
4437        if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
4438                goto restore_state;
4439
4440        /* Stage 4 - delete old state(s) */
4441        if (nx_cur) {
4442                xfrm_states_put(x_cur, nx_cur);
4443                xfrm_states_delete(x_cur, nx_cur);
4444        }
4445
4446        /* Stage 5 - announce */
4447        km_migrate(sel, dir, type, m, num_migrate, k, encap);
4448
4449        xfrm_pol_put(pol);
4450
4451        return 0;
4452out:
4453        return err;
4454
4455restore_state:
4456        if (pol)
4457                xfrm_pol_put(pol);
4458        if (nx_cur)
4459                xfrm_states_put(x_cur, nx_cur);
4460        if (nx_new)
4461                xfrm_states_delete(x_new, nx_new);
4462
4463        return err;
4464}
4465EXPORT_SYMBOL(xfrm_migrate);
4466#endif
4467