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