linux/net/xfrm/xfrm_policy.c
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   1/*
   2 * xfrm_policy.c
   3 *
   4 * Changes:
   5 *      Mitsuru KANDA @USAGI
   6 *      Kazunori MIYAZAWA @USAGI
   7 *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
   8 *              IPv6 support
   9 *      Kazunori MIYAZAWA @USAGI
  10 *      YOSHIFUJI Hideaki
  11 *              Split up af-specific portion
  12 *      Derek Atkins <derek@ihtfp.com>          Add the post_input processor
  13 *
  14 */
  15
  16#include <linux/err.h>
  17#include <linux/slab.h>
  18#include <linux/kmod.h>
  19#include <linux/list.h>
  20#include <linux/spinlock.h>
  21#include <linux/workqueue.h>
  22#include <linux/notifier.h>
  23#include <linux/netdevice.h>
  24#include <linux/netfilter.h>
  25#include <linux/module.h>
  26#include <linux/cache.h>
  27#include <linux/audit.h>
  28#include <net/dst.h>
  29#include <net/flow.h>
  30#include <net/xfrm.h>
  31#include <net/ip.h>
  32#ifdef CONFIG_XFRM_STATISTICS
  33#include <net/snmp.h>
  34#endif
  35
  36#include "xfrm_hash.h"
  37
  38DEFINE_MUTEX(xfrm_cfg_mutex);
  39EXPORT_SYMBOL(xfrm_cfg_mutex);
  40
  41static DEFINE_SPINLOCK(xfrm_policy_sk_bundle_lock);
  42static struct dst_entry *xfrm_policy_sk_bundles;
  43static DEFINE_RWLOCK(xfrm_policy_lock);
  44
  45static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
  46static struct xfrm_policy_afinfo __rcu *xfrm_policy_afinfo[NPROTO]
  47                                                __read_mostly;
  48
  49static struct kmem_cache *xfrm_dst_cache __read_mostly;
  50
  51static void xfrm_init_pmtu(struct dst_entry *dst);
  52static int stale_bundle(struct dst_entry *dst);
  53static int xfrm_bundle_ok(struct xfrm_dst *xdst);
  54
  55
  56static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
  57                                                int dir);
  58
  59static inline bool
  60__xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
  61{
  62        const struct flowi4 *fl4 = &fl->u.ip4;
  63
  64        return  addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
  65                addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
  66                !((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
  67                !((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
  68                (fl4->flowi4_proto == sel->proto || !sel->proto) &&
  69                (fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
  70}
  71
  72static inline bool
  73__xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
  74{
  75        const struct flowi6 *fl6 = &fl->u.ip6;
  76
  77        return  addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
  78                addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
  79                !((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
  80                !((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
  81                (fl6->flowi6_proto == sel->proto || !sel->proto) &&
  82                (fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
  83}
  84
  85bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
  86                         unsigned short family)
  87{
  88        switch (family) {
  89        case AF_INET:
  90                return __xfrm4_selector_match(sel, fl);
  91        case AF_INET6:
  92                return __xfrm6_selector_match(sel, fl);
  93        }
  94        return false;
  95}
  96
  97static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
  98{
  99        struct xfrm_policy_afinfo *afinfo;
 100
 101        if (unlikely(family >= NPROTO))
 102                return NULL;
 103        rcu_read_lock();
 104        afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
 105        if (unlikely(!afinfo))
 106                rcu_read_unlock();
 107        return afinfo;
 108}
 109
 110static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
 111{
 112        rcu_read_unlock();
 113}
 114
 115static inline struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos,
 116                                                  const xfrm_address_t *saddr,
 117                                                  const xfrm_address_t *daddr,
 118                                                  int family)
 119{
 120        struct xfrm_policy_afinfo *afinfo;
 121        struct dst_entry *dst;
 122
 123        afinfo = xfrm_policy_get_afinfo(family);
 124        if (unlikely(afinfo == NULL))
 125                return ERR_PTR(-EAFNOSUPPORT);
 126
 127        dst = afinfo->dst_lookup(net, tos, saddr, daddr);
 128
 129        xfrm_policy_put_afinfo(afinfo);
 130
 131        return dst;
 132}
 133
 134static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x, int tos,
 135                                                xfrm_address_t *prev_saddr,
 136                                                xfrm_address_t *prev_daddr,
 137                                                int family)
 138{
 139        struct net *net = xs_net(x);
 140        xfrm_address_t *saddr = &x->props.saddr;
 141        xfrm_address_t *daddr = &x->id.daddr;
 142        struct dst_entry *dst;
 143
 144        if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
 145                saddr = x->coaddr;
 146                daddr = prev_daddr;
 147        }
 148        if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
 149                saddr = prev_saddr;
 150                daddr = x->coaddr;
 151        }
 152
 153        dst = __xfrm_dst_lookup(net, tos, saddr, daddr, family);
 154
 155        if (!IS_ERR(dst)) {
 156                if (prev_saddr != saddr)
 157                        memcpy(prev_saddr, saddr,  sizeof(*prev_saddr));
 158                if (prev_daddr != daddr)
 159                        memcpy(prev_daddr, daddr,  sizeof(*prev_daddr));
 160        }
 161
 162        return dst;
 163}
 164
 165static inline unsigned long make_jiffies(long secs)
 166{
 167        if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
 168                return MAX_SCHEDULE_TIMEOUT-1;
 169        else
 170                return secs*HZ;
 171}
 172
 173static void xfrm_policy_timer(unsigned long data)
 174{
 175        struct xfrm_policy *xp = (struct xfrm_policy*)data;
 176        unsigned long now = get_seconds();
 177        long next = LONG_MAX;
 178        int warn = 0;
 179        int dir;
 180
 181        read_lock(&xp->lock);
 182
 183        if (unlikely(xp->walk.dead))
 184                goto out;
 185
 186        dir = xfrm_policy_id2dir(xp->index);
 187
 188        if (xp->lft.hard_add_expires_seconds) {
 189                long tmo = xp->lft.hard_add_expires_seconds +
 190                        xp->curlft.add_time - now;
 191                if (tmo <= 0)
 192                        goto expired;
 193                if (tmo < next)
 194                        next = tmo;
 195        }
 196        if (xp->lft.hard_use_expires_seconds) {
 197                long tmo = xp->lft.hard_use_expires_seconds +
 198                        (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 199                if (tmo <= 0)
 200                        goto expired;
 201                if (tmo < next)
 202                        next = tmo;
 203        }
 204        if (xp->lft.soft_add_expires_seconds) {
 205                long tmo = xp->lft.soft_add_expires_seconds +
 206                        xp->curlft.add_time - now;
 207                if (tmo <= 0) {
 208                        warn = 1;
 209                        tmo = XFRM_KM_TIMEOUT;
 210                }
 211                if (tmo < next)
 212                        next = tmo;
 213        }
 214        if (xp->lft.soft_use_expires_seconds) {
 215                long tmo = xp->lft.soft_use_expires_seconds +
 216                        (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 217                if (tmo <= 0) {
 218                        warn = 1;
 219                        tmo = XFRM_KM_TIMEOUT;
 220                }
 221                if (tmo < next)
 222                        next = tmo;
 223        }
 224
 225        if (warn)
 226                km_policy_expired(xp, dir, 0, 0);
 227        if (next != LONG_MAX &&
 228            !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
 229                xfrm_pol_hold(xp);
 230
 231out:
 232        read_unlock(&xp->lock);
 233        xfrm_pol_put(xp);
 234        return;
 235
 236expired:
 237        read_unlock(&xp->lock);
 238        if (!xfrm_policy_delete(xp, dir))
 239                km_policy_expired(xp, dir, 1, 0);
 240        xfrm_pol_put(xp);
 241}
 242
 243static struct flow_cache_object *xfrm_policy_flo_get(struct flow_cache_object *flo)
 244{
 245        struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
 246
 247        if (unlikely(pol->walk.dead))
 248                flo = NULL;
 249        else
 250                xfrm_pol_hold(pol);
 251
 252        return flo;
 253}
 254
 255static int xfrm_policy_flo_check(struct flow_cache_object *flo)
 256{
 257        struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
 258
 259        return !pol->walk.dead;
 260}
 261
 262static void xfrm_policy_flo_delete(struct flow_cache_object *flo)
 263{
 264        xfrm_pol_put(container_of(flo, struct xfrm_policy, flo));
 265}
 266
 267static const struct flow_cache_ops xfrm_policy_fc_ops = {
 268        .get = xfrm_policy_flo_get,
 269        .check = xfrm_policy_flo_check,
 270        .delete = xfrm_policy_flo_delete,
 271};
 272
 273/* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
 274 * SPD calls.
 275 */
 276
 277struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
 278{
 279        struct xfrm_policy *policy;
 280
 281        policy = kzalloc(sizeof(struct xfrm_policy), gfp);
 282
 283        if (policy) {
 284                write_pnet(&policy->xp_net, net);
 285                INIT_LIST_HEAD(&policy->walk.all);
 286                INIT_HLIST_NODE(&policy->bydst);
 287                INIT_HLIST_NODE(&policy->byidx);
 288                rwlock_init(&policy->lock);
 289                atomic_set(&policy->refcnt, 1);
 290                setup_timer(&policy->timer, xfrm_policy_timer,
 291                                (unsigned long)policy);
 292                policy->flo.ops = &xfrm_policy_fc_ops;
 293        }
 294        return policy;
 295}
 296EXPORT_SYMBOL(xfrm_policy_alloc);
 297
 298/* Destroy xfrm_policy: descendant resources must be released to this moment. */
 299
 300void xfrm_policy_destroy(struct xfrm_policy *policy)
 301{
 302        BUG_ON(!policy->walk.dead);
 303
 304        if (del_timer(&policy->timer))
 305                BUG();
 306
 307        security_xfrm_policy_free(policy->security);
 308        kfree(policy);
 309}
 310EXPORT_SYMBOL(xfrm_policy_destroy);
 311
 312/* Rule must be locked. Release descentant resources, announce
 313 * entry dead. The rule must be unlinked from lists to the moment.
 314 */
 315
 316static void xfrm_policy_kill(struct xfrm_policy *policy)
 317{
 318        policy->walk.dead = 1;
 319
 320        atomic_inc(&policy->genid);
 321
 322        if (del_timer(&policy->timer))
 323                xfrm_pol_put(policy);
 324
 325        xfrm_pol_put(policy);
 326}
 327
 328static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
 329
 330static inline unsigned int idx_hash(struct net *net, u32 index)
 331{
 332        return __idx_hash(index, net->xfrm.policy_idx_hmask);
 333}
 334
 335static struct hlist_head *policy_hash_bysel(struct net *net,
 336                                            const struct xfrm_selector *sel,
 337                                            unsigned short family, int dir)
 338{
 339        unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 340        unsigned int hash = __sel_hash(sel, family, hmask);
 341
 342        return (hash == hmask + 1 ?
 343                &net->xfrm.policy_inexact[dir] :
 344                net->xfrm.policy_bydst[dir].table + hash);
 345}
 346
 347static struct hlist_head *policy_hash_direct(struct net *net,
 348                                             const xfrm_address_t *daddr,
 349                                             const xfrm_address_t *saddr,
 350                                             unsigned short family, int dir)
 351{
 352        unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 353        unsigned int hash = __addr_hash(daddr, saddr, family, hmask);
 354
 355        return net->xfrm.policy_bydst[dir].table + hash;
 356}
 357
 358static void xfrm_dst_hash_transfer(struct hlist_head *list,
 359                                   struct hlist_head *ndsttable,
 360                                   unsigned int nhashmask)
 361{
 362        struct hlist_node *entry, *tmp, *entry0 = NULL;
 363        struct xfrm_policy *pol;
 364        unsigned int h0 = 0;
 365
 366redo:
 367        hlist_for_each_entry_safe(pol, entry, tmp, list, bydst) {
 368                unsigned int h;
 369
 370                h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
 371                                pol->family, nhashmask);
 372                if (!entry0) {
 373                        hlist_del(entry);
 374                        hlist_add_head(&pol->bydst, ndsttable+h);
 375                        h0 = h;
 376                } else {
 377                        if (h != h0)
 378                                continue;
 379                        hlist_del(entry);
 380                        hlist_add_after(entry0, &pol->bydst);
 381                }
 382                entry0 = entry;
 383        }
 384        if (!hlist_empty(list)) {
 385                entry0 = NULL;
 386                goto redo;
 387        }
 388}
 389
 390static void xfrm_idx_hash_transfer(struct hlist_head *list,
 391                                   struct hlist_head *nidxtable,
 392                                   unsigned int nhashmask)
 393{
 394        struct hlist_node *entry, *tmp;
 395        struct xfrm_policy *pol;
 396
 397        hlist_for_each_entry_safe(pol, entry, tmp, list, byidx) {
 398                unsigned int h;
 399
 400                h = __idx_hash(pol->index, nhashmask);
 401                hlist_add_head(&pol->byidx, nidxtable+h);
 402        }
 403}
 404
 405static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
 406{
 407        return ((old_hmask + 1) << 1) - 1;
 408}
 409
 410static void xfrm_bydst_resize(struct net *net, int dir)
 411{
 412        unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 413        unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 414        unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 415        struct hlist_head *odst = net->xfrm.policy_bydst[dir].table;
 416        struct hlist_head *ndst = xfrm_hash_alloc(nsize);
 417        int i;
 418
 419        if (!ndst)
 420                return;
 421
 422        write_lock_bh(&xfrm_policy_lock);
 423
 424        for (i = hmask; i >= 0; i--)
 425                xfrm_dst_hash_transfer(odst + i, ndst, nhashmask);
 426
 427        net->xfrm.policy_bydst[dir].table = ndst;
 428        net->xfrm.policy_bydst[dir].hmask = nhashmask;
 429
 430        write_unlock_bh(&xfrm_policy_lock);
 431
 432        xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
 433}
 434
 435static void xfrm_byidx_resize(struct net *net, int total)
 436{
 437        unsigned int hmask = net->xfrm.policy_idx_hmask;
 438        unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 439        unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 440        struct hlist_head *oidx = net->xfrm.policy_byidx;
 441        struct hlist_head *nidx = xfrm_hash_alloc(nsize);
 442        int i;
 443
 444        if (!nidx)
 445                return;
 446
 447        write_lock_bh(&xfrm_policy_lock);
 448
 449        for (i = hmask; i >= 0; i--)
 450                xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
 451
 452        net->xfrm.policy_byidx = nidx;
 453        net->xfrm.policy_idx_hmask = nhashmask;
 454
 455        write_unlock_bh(&xfrm_policy_lock);
 456
 457        xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
 458}
 459
 460static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
 461{
 462        unsigned int cnt = net->xfrm.policy_count[dir];
 463        unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 464
 465        if (total)
 466                *total += cnt;
 467
 468        if ((hmask + 1) < xfrm_policy_hashmax &&
 469            cnt > hmask)
 470                return 1;
 471
 472        return 0;
 473}
 474
 475static inline int xfrm_byidx_should_resize(struct net *net, int total)
 476{
 477        unsigned int hmask = net->xfrm.policy_idx_hmask;
 478
 479        if ((hmask + 1) < xfrm_policy_hashmax &&
 480            total > hmask)
 481                return 1;
 482
 483        return 0;
 484}
 485
 486void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
 487{
 488        read_lock_bh(&xfrm_policy_lock);
 489        si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
 490        si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
 491        si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
 492        si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
 493        si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
 494        si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
 495        si->spdhcnt = net->xfrm.policy_idx_hmask;
 496        si->spdhmcnt = xfrm_policy_hashmax;
 497        read_unlock_bh(&xfrm_policy_lock);
 498}
 499EXPORT_SYMBOL(xfrm_spd_getinfo);
 500
 501static DEFINE_MUTEX(hash_resize_mutex);
 502static void xfrm_hash_resize(struct work_struct *work)
 503{
 504        struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
 505        int dir, total;
 506
 507        mutex_lock(&hash_resize_mutex);
 508
 509        total = 0;
 510        for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
 511                if (xfrm_bydst_should_resize(net, dir, &total))
 512                        xfrm_bydst_resize(net, dir);
 513        }
 514        if (xfrm_byidx_should_resize(net, total))
 515                xfrm_byidx_resize(net, total);
 516
 517        mutex_unlock(&hash_resize_mutex);
 518}
 519
 520/* Generate new index... KAME seems to generate them ordered by cost
 521 * of an absolute inpredictability of ordering of rules. This will not pass. */
 522static u32 xfrm_gen_index(struct net *net, int dir)
 523{
 524        static u32 idx_generator;
 525
 526        for (;;) {
 527                struct hlist_node *entry;
 528                struct hlist_head *list;
 529                struct xfrm_policy *p;
 530                u32 idx;
 531                int found;
 532
 533                idx = (idx_generator | dir);
 534                idx_generator += 8;
 535                if (idx == 0)
 536                        idx = 8;
 537                list = net->xfrm.policy_byidx + idx_hash(net, idx);
 538                found = 0;
 539                hlist_for_each_entry(p, entry, list, byidx) {
 540                        if (p->index == idx) {
 541                                found = 1;
 542                                break;
 543                        }
 544                }
 545                if (!found)
 546                        return idx;
 547        }
 548}
 549
 550static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
 551{
 552        u32 *p1 = (u32 *) s1;
 553        u32 *p2 = (u32 *) s2;
 554        int len = sizeof(struct xfrm_selector) / sizeof(u32);
 555        int i;
 556
 557        for (i = 0; i < len; i++) {
 558                if (p1[i] != p2[i])
 559                        return 1;
 560        }
 561
 562        return 0;
 563}
 564
 565int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 566{
 567        struct net *net = xp_net(policy);
 568        struct xfrm_policy *pol;
 569        struct xfrm_policy *delpol;
 570        struct hlist_head *chain;
 571        struct hlist_node *entry, *newpos;
 572        u32 mark = policy->mark.v & policy->mark.m;
 573
 574        write_lock_bh(&xfrm_policy_lock);
 575        chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
 576        delpol = NULL;
 577        newpos = NULL;
 578        hlist_for_each_entry(pol, entry, chain, bydst) {
 579                if (pol->type == policy->type &&
 580                    !selector_cmp(&pol->selector, &policy->selector) &&
 581                    (mark & pol->mark.m) == pol->mark.v &&
 582                    xfrm_sec_ctx_match(pol->security, policy->security) &&
 583                    !WARN_ON(delpol)) {
 584                        if (excl) {
 585                                write_unlock_bh(&xfrm_policy_lock);
 586                                return -EEXIST;
 587                        }
 588                        delpol = pol;
 589                        if (policy->priority > pol->priority)
 590                                continue;
 591                } else if (policy->priority >= pol->priority) {
 592                        newpos = &pol->bydst;
 593                        continue;
 594                }
 595                if (delpol)
 596                        break;
 597        }
 598        if (newpos)
 599                hlist_add_after(newpos, &policy->bydst);
 600        else
 601                hlist_add_head(&policy->bydst, chain);
 602        xfrm_pol_hold(policy);
 603        net->xfrm.policy_count[dir]++;
 604        atomic_inc(&flow_cache_genid);
 605        rt_genid_bump(net);
 606        if (delpol)
 607                __xfrm_policy_unlink(delpol, dir);
 608        policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir);
 609        hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
 610        policy->curlft.add_time = get_seconds();
 611        policy->curlft.use_time = 0;
 612        if (!mod_timer(&policy->timer, jiffies + HZ))
 613                xfrm_pol_hold(policy);
 614        list_add(&policy->walk.all, &net->xfrm.policy_all);
 615        write_unlock_bh(&xfrm_policy_lock);
 616
 617        if (delpol)
 618                xfrm_policy_kill(delpol);
 619        else if (xfrm_bydst_should_resize(net, dir, NULL))
 620                schedule_work(&net->xfrm.policy_hash_work);
 621
 622        return 0;
 623}
 624EXPORT_SYMBOL(xfrm_policy_insert);
 625
 626struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type,
 627                                          int dir, struct xfrm_selector *sel,
 628                                          struct xfrm_sec_ctx *ctx, int delete,
 629                                          int *err)
 630{
 631        struct xfrm_policy *pol, *ret;
 632        struct hlist_head *chain;
 633        struct hlist_node *entry;
 634
 635        *err = 0;
 636        write_lock_bh(&xfrm_policy_lock);
 637        chain = policy_hash_bysel(net, sel, sel->family, dir);
 638        ret = NULL;
 639        hlist_for_each_entry(pol, entry, chain, bydst) {
 640                if (pol->type == type &&
 641                    (mark & pol->mark.m) == pol->mark.v &&
 642                    !selector_cmp(sel, &pol->selector) &&
 643                    xfrm_sec_ctx_match(ctx, pol->security)) {
 644                        xfrm_pol_hold(pol);
 645                        if (delete) {
 646                                *err = security_xfrm_policy_delete(
 647                                                                pol->security);
 648                                if (*err) {
 649                                        write_unlock_bh(&xfrm_policy_lock);
 650                                        return pol;
 651                                }
 652                                __xfrm_policy_unlink(pol, dir);
 653                        }
 654                        ret = pol;
 655                        break;
 656                }
 657        }
 658        write_unlock_bh(&xfrm_policy_lock);
 659
 660        if (ret && delete)
 661                xfrm_policy_kill(ret);
 662        return ret;
 663}
 664EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
 665
 666struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type,
 667                                     int dir, u32 id, int delete, int *err)
 668{
 669        struct xfrm_policy *pol, *ret;
 670        struct hlist_head *chain;
 671        struct hlist_node *entry;
 672
 673        *err = -ENOENT;
 674        if (xfrm_policy_id2dir(id) != dir)
 675                return NULL;
 676
 677        *err = 0;
 678        write_lock_bh(&xfrm_policy_lock);
 679        chain = net->xfrm.policy_byidx + idx_hash(net, id);
 680        ret = NULL;
 681        hlist_for_each_entry(pol, entry, chain, byidx) {
 682                if (pol->type == type && pol->index == id &&
 683                    (mark & pol->mark.m) == pol->mark.v) {
 684                        xfrm_pol_hold(pol);
 685                        if (delete) {
 686                                *err = security_xfrm_policy_delete(
 687                                                                pol->security);
 688                                if (*err) {
 689                                        write_unlock_bh(&xfrm_policy_lock);
 690                                        return pol;
 691                                }
 692                                __xfrm_policy_unlink(pol, dir);
 693                        }
 694                        ret = pol;
 695                        break;
 696                }
 697        }
 698        write_unlock_bh(&xfrm_policy_lock);
 699
 700        if (ret && delete)
 701                xfrm_policy_kill(ret);
 702        return ret;
 703}
 704EXPORT_SYMBOL(xfrm_policy_byid);
 705
 706#ifdef CONFIG_SECURITY_NETWORK_XFRM
 707static inline int
 708xfrm_policy_flush_secctx_check(struct net *net, u8 type, struct xfrm_audit *audit_info)
 709{
 710        int dir, err = 0;
 711
 712        for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 713                struct xfrm_policy *pol;
 714                struct hlist_node *entry;
 715                int i;
 716
 717                hlist_for_each_entry(pol, entry,
 718                                     &net->xfrm.policy_inexact[dir], bydst) {
 719                        if (pol->type != type)
 720                                continue;
 721                        err = security_xfrm_policy_delete(pol->security);
 722                        if (err) {
 723                                xfrm_audit_policy_delete(pol, 0,
 724                                                         audit_info->loginuid,
 725                                                         audit_info->sessionid,
 726                                                         audit_info->secid);
 727                                return err;
 728                        }
 729                }
 730                for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
 731                        hlist_for_each_entry(pol, entry,
 732                                             net->xfrm.policy_bydst[dir].table + i,
 733                                             bydst) {
 734                                if (pol->type != type)
 735                                        continue;
 736                                err = security_xfrm_policy_delete(
 737                                                                pol->security);
 738                                if (err) {
 739                                        xfrm_audit_policy_delete(pol, 0,
 740                                                        audit_info->loginuid,
 741                                                        audit_info->sessionid,
 742                                                        audit_info->secid);
 743                                        return err;
 744                                }
 745                        }
 746                }
 747        }
 748        return err;
 749}
 750#else
 751static inline int
 752xfrm_policy_flush_secctx_check(struct net *net, u8 type, struct xfrm_audit *audit_info)
 753{
 754        return 0;
 755}
 756#endif
 757
 758int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
 759{
 760        int dir, err = 0, cnt = 0;
 761
 762        write_lock_bh(&xfrm_policy_lock);
 763
 764        err = xfrm_policy_flush_secctx_check(net, type, audit_info);
 765        if (err)
 766                goto out;
 767
 768        for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 769                struct xfrm_policy *pol;
 770                struct hlist_node *entry;
 771                int i;
 772
 773        again1:
 774                hlist_for_each_entry(pol, entry,
 775                                     &net->xfrm.policy_inexact[dir], bydst) {
 776                        if (pol->type != type)
 777                                continue;
 778                        __xfrm_policy_unlink(pol, dir);
 779                        write_unlock_bh(&xfrm_policy_lock);
 780                        cnt++;
 781
 782                        xfrm_audit_policy_delete(pol, 1, audit_info->loginuid,
 783                                                 audit_info->sessionid,
 784                                                 audit_info->secid);
 785
 786                        xfrm_policy_kill(pol);
 787
 788                        write_lock_bh(&xfrm_policy_lock);
 789                        goto again1;
 790                }
 791
 792                for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
 793        again2:
 794                        hlist_for_each_entry(pol, entry,
 795                                             net->xfrm.policy_bydst[dir].table + i,
 796                                             bydst) {
 797                                if (pol->type != type)
 798                                        continue;
 799                                __xfrm_policy_unlink(pol, dir);
 800                                write_unlock_bh(&xfrm_policy_lock);
 801                                cnt++;
 802
 803                                xfrm_audit_policy_delete(pol, 1,
 804                                                         audit_info->loginuid,
 805                                                         audit_info->sessionid,
 806                                                         audit_info->secid);
 807                                xfrm_policy_kill(pol);
 808
 809                                write_lock_bh(&xfrm_policy_lock);
 810                                goto again2;
 811                        }
 812                }
 813
 814        }
 815        if (!cnt)
 816                err = -ESRCH;
 817out:
 818        write_unlock_bh(&xfrm_policy_lock);
 819        return err;
 820}
 821EXPORT_SYMBOL(xfrm_policy_flush);
 822
 823int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
 824                     int (*func)(struct xfrm_policy *, int, int, void*),
 825                     void *data)
 826{
 827        struct xfrm_policy *pol;
 828        struct xfrm_policy_walk_entry *x;
 829        int error = 0;
 830
 831        if (walk->type >= XFRM_POLICY_TYPE_MAX &&
 832            walk->type != XFRM_POLICY_TYPE_ANY)
 833                return -EINVAL;
 834
 835        if (list_empty(&walk->walk.all) && walk->seq != 0)
 836                return 0;
 837
 838        write_lock_bh(&xfrm_policy_lock);
 839        if (list_empty(&walk->walk.all))
 840                x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
 841        else
 842                x = list_entry(&walk->walk.all, struct xfrm_policy_walk_entry, all);
 843        list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
 844                if (x->dead)
 845                        continue;
 846                pol = container_of(x, struct xfrm_policy, walk);
 847                if (walk->type != XFRM_POLICY_TYPE_ANY &&
 848                    walk->type != pol->type)
 849                        continue;
 850                error = func(pol, xfrm_policy_id2dir(pol->index),
 851                             walk->seq, data);
 852                if (error) {
 853                        list_move_tail(&walk->walk.all, &x->all);
 854                        goto out;
 855                }
 856                walk->seq++;
 857        }
 858        if (walk->seq == 0) {
 859                error = -ENOENT;
 860                goto out;
 861        }
 862        list_del_init(&walk->walk.all);
 863out:
 864        write_unlock_bh(&xfrm_policy_lock);
 865        return error;
 866}
 867EXPORT_SYMBOL(xfrm_policy_walk);
 868
 869void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
 870{
 871        INIT_LIST_HEAD(&walk->walk.all);
 872        walk->walk.dead = 1;
 873        walk->type = type;
 874        walk->seq = 0;
 875}
 876EXPORT_SYMBOL(xfrm_policy_walk_init);
 877
 878void xfrm_policy_walk_done(struct xfrm_policy_walk *walk)
 879{
 880        if (list_empty(&walk->walk.all))
 881                return;
 882
 883        write_lock_bh(&xfrm_policy_lock);
 884        list_del(&walk->walk.all);
 885        write_unlock_bh(&xfrm_policy_lock);
 886}
 887EXPORT_SYMBOL(xfrm_policy_walk_done);
 888
 889/*
 890 * Find policy to apply to this flow.
 891 *
 892 * Returns 0 if policy found, else an -errno.
 893 */
 894static int xfrm_policy_match(const struct xfrm_policy *pol,
 895                             const struct flowi *fl,
 896                             u8 type, u16 family, int dir)
 897{
 898        const struct xfrm_selector *sel = &pol->selector;
 899        int ret = -ESRCH;
 900        bool match;
 901
 902        if (pol->family != family ||
 903            (fl->flowi_mark & pol->mark.m) != pol->mark.v ||
 904            pol->type != type)
 905                return ret;
 906
 907        match = xfrm_selector_match(sel, fl, family);
 908        if (match)
 909                ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid,
 910                                                  dir);
 911
 912        return ret;
 913}
 914
 915static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
 916                                                     const struct flowi *fl,
 917                                                     u16 family, u8 dir)
 918{
 919        int err;
 920        struct xfrm_policy *pol, *ret;
 921        const xfrm_address_t *daddr, *saddr;
 922        struct hlist_node *entry;
 923        struct hlist_head *chain;
 924        u32 priority = ~0U;
 925
 926        daddr = xfrm_flowi_daddr(fl, family);
 927        saddr = xfrm_flowi_saddr(fl, family);
 928        if (unlikely(!daddr || !saddr))
 929                return NULL;
 930
 931        read_lock_bh(&xfrm_policy_lock);
 932        chain = policy_hash_direct(net, daddr, saddr, family, dir);
 933        ret = NULL;
 934        hlist_for_each_entry(pol, entry, chain, bydst) {
 935                err = xfrm_policy_match(pol, fl, type, family, dir);
 936                if (err) {
 937                        if (err == -ESRCH)
 938                                continue;
 939                        else {
 940                                ret = ERR_PTR(err);
 941                                goto fail;
 942                        }
 943                } else {
 944                        ret = pol;
 945                        priority = ret->priority;
 946                        break;
 947                }
 948        }
 949        chain = &net->xfrm.policy_inexact[dir];
 950        hlist_for_each_entry(pol, entry, chain, bydst) {
 951                err = xfrm_policy_match(pol, fl, type, family, dir);
 952                if (err) {
 953                        if (err == -ESRCH)
 954                                continue;
 955                        else {
 956                                ret = ERR_PTR(err);
 957                                goto fail;
 958                        }
 959                } else if (pol->priority < priority) {
 960                        ret = pol;
 961                        break;
 962                }
 963        }
 964        if (ret)
 965                xfrm_pol_hold(ret);
 966fail:
 967        read_unlock_bh(&xfrm_policy_lock);
 968
 969        return ret;
 970}
 971
 972static struct xfrm_policy *
 973__xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir)
 974{
 975#ifdef CONFIG_XFRM_SUB_POLICY
 976        struct xfrm_policy *pol;
 977
 978        pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family, dir);
 979        if (pol != NULL)
 980                return pol;
 981#endif
 982        return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family, dir);
 983}
 984
 985static struct flow_cache_object *
 986xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family,
 987                   u8 dir, struct flow_cache_object *old_obj, void *ctx)
 988{
 989        struct xfrm_policy *pol;
 990
 991        if (old_obj)
 992                xfrm_pol_put(container_of(old_obj, struct xfrm_policy, flo));
 993
 994        pol = __xfrm_policy_lookup(net, fl, family, dir);
 995        if (IS_ERR_OR_NULL(pol))
 996                return ERR_CAST(pol);
 997
 998        /* Resolver returns two references:
 999         * one for cache and one for caller of flow_cache_lookup() */
1000        xfrm_pol_hold(pol);
1001
1002        return &pol->flo;
1003}
1004
1005static inline int policy_to_flow_dir(int dir)
1006{
1007        if (XFRM_POLICY_IN == FLOW_DIR_IN &&
1008            XFRM_POLICY_OUT == FLOW_DIR_OUT &&
1009            XFRM_POLICY_FWD == FLOW_DIR_FWD)
1010                return dir;
1011        switch (dir) {
1012        default:
1013        case XFRM_POLICY_IN:
1014                return FLOW_DIR_IN;
1015        case XFRM_POLICY_OUT:
1016                return FLOW_DIR_OUT;
1017        case XFRM_POLICY_FWD:
1018                return FLOW_DIR_FWD;
1019        }
1020}
1021
1022static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir,
1023                                                 const struct flowi *fl)
1024{
1025        struct xfrm_policy *pol;
1026
1027        read_lock_bh(&xfrm_policy_lock);
1028        if ((pol = sk->sk_policy[dir]) != NULL) {
1029                bool match = xfrm_selector_match(&pol->selector, fl,
1030                                                 sk->sk_family);
1031                int err = 0;
1032
1033                if (match) {
1034                        if ((sk->sk_mark & pol->mark.m) != pol->mark.v) {
1035                                pol = NULL;
1036                                goto out;
1037                        }
1038                        err = security_xfrm_policy_lookup(pol->security,
1039                                                      fl->flowi_secid,
1040                                                      policy_to_flow_dir(dir));
1041                        if (!err)
1042                                xfrm_pol_hold(pol);
1043                        else if (err == -ESRCH)
1044                                pol = NULL;
1045                        else
1046                                pol = ERR_PTR(err);
1047                } else
1048                        pol = NULL;
1049        }
1050out:
1051        read_unlock_bh(&xfrm_policy_lock);
1052        return pol;
1053}
1054
1055static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
1056{
1057        struct net *net = xp_net(pol);
1058        struct hlist_head *chain = policy_hash_bysel(net, &pol->selector,
1059                                                     pol->family, dir);
1060
1061        list_add(&pol->walk.all, &net->xfrm.policy_all);
1062        hlist_add_head(&pol->bydst, chain);
1063        hlist_add_head(&pol->byidx, net->xfrm.policy_byidx+idx_hash(net, pol->index));
1064        net->xfrm.policy_count[dir]++;
1065        xfrm_pol_hold(pol);
1066
1067        if (xfrm_bydst_should_resize(net, dir, NULL))
1068                schedule_work(&net->xfrm.policy_hash_work);
1069}
1070
1071static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
1072                                                int dir)
1073{
1074        struct net *net = xp_net(pol);
1075
1076        if (hlist_unhashed(&pol->bydst))
1077                return NULL;
1078
1079        hlist_del(&pol->bydst);
1080        hlist_del(&pol->byidx);
1081        list_del(&pol->walk.all);
1082        net->xfrm.policy_count[dir]--;
1083
1084        return pol;
1085}
1086
1087int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
1088{
1089        write_lock_bh(&xfrm_policy_lock);
1090        pol = __xfrm_policy_unlink(pol, dir);
1091        write_unlock_bh(&xfrm_policy_lock);
1092        if (pol) {
1093                xfrm_policy_kill(pol);
1094                return 0;
1095        }
1096        return -ENOENT;
1097}
1098EXPORT_SYMBOL(xfrm_policy_delete);
1099
1100int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
1101{
1102        struct net *net = xp_net(pol);
1103        struct xfrm_policy *old_pol;
1104
1105#ifdef CONFIG_XFRM_SUB_POLICY
1106        if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
1107                return -EINVAL;
1108#endif
1109
1110        write_lock_bh(&xfrm_policy_lock);
1111        old_pol = sk->sk_policy[dir];
1112        sk->sk_policy[dir] = pol;
1113        if (pol) {
1114                pol->curlft.add_time = get_seconds();
1115                pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir);
1116                __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
1117        }
1118        if (old_pol)
1119                /* Unlinking succeeds always. This is the only function
1120                 * allowed to delete or replace socket policy.
1121                 */
1122                __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
1123        write_unlock_bh(&xfrm_policy_lock);
1124
1125        if (old_pol) {
1126                xfrm_policy_kill(old_pol);
1127        }
1128        return 0;
1129}
1130
1131static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
1132{
1133        struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
1134
1135        if (newp) {
1136                newp->selector = old->selector;
1137                if (security_xfrm_policy_clone(old->security,
1138                                               &newp->security)) {
1139                        kfree(newp);
1140                        return NULL;  /* ENOMEM */
1141                }
1142                newp->lft = old->lft;
1143                newp->curlft = old->curlft;
1144                newp->mark = old->mark;
1145                newp->action = old->action;
1146                newp->flags = old->flags;
1147                newp->xfrm_nr = old->xfrm_nr;
1148                newp->index = old->index;
1149                newp->type = old->type;
1150                memcpy(newp->xfrm_vec, old->xfrm_vec,
1151                       newp->xfrm_nr*sizeof(struct xfrm_tmpl));
1152                write_lock_bh(&xfrm_policy_lock);
1153                __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
1154                write_unlock_bh(&xfrm_policy_lock);
1155                xfrm_pol_put(newp);
1156        }
1157        return newp;
1158}
1159
1160int __xfrm_sk_clone_policy(struct sock *sk)
1161{
1162        struct xfrm_policy *p0 = sk->sk_policy[0],
1163                           *p1 = sk->sk_policy[1];
1164
1165        sk->sk_policy[0] = sk->sk_policy[1] = NULL;
1166        if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
1167                return -ENOMEM;
1168        if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
1169                return -ENOMEM;
1170        return 0;
1171}
1172
1173static int
1174xfrm_get_saddr(struct net *net, xfrm_address_t *local, xfrm_address_t *remote,
1175               unsigned short family)
1176{
1177        int err;
1178        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1179
1180        if (unlikely(afinfo == NULL))
1181                return -EINVAL;
1182        err = afinfo->get_saddr(net, local, remote);
1183        xfrm_policy_put_afinfo(afinfo);
1184        return err;
1185}
1186
1187/* Resolve list of templates for the flow, given policy. */
1188
1189static int
1190xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
1191                      struct xfrm_state **xfrm, unsigned short family)
1192{
1193        struct net *net = xp_net(policy);
1194        int nx;
1195        int i, error;
1196        xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
1197        xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
1198        xfrm_address_t tmp;
1199
1200        for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
1201                struct xfrm_state *x;
1202                xfrm_address_t *remote = daddr;
1203                xfrm_address_t *local  = saddr;
1204                struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
1205
1206                if (tmpl->mode == XFRM_MODE_TUNNEL ||
1207                    tmpl->mode == XFRM_MODE_BEET) {
1208                        remote = &tmpl->id.daddr;
1209                        local = &tmpl->saddr;
1210                        if (xfrm_addr_any(local, tmpl->encap_family)) {
1211                                error = xfrm_get_saddr(net, &tmp, remote, tmpl->encap_family);
1212                                if (error)
1213                                        goto fail;
1214                                local = &tmp;
1215                        }
1216                }
1217
1218                x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
1219
1220                if (x && x->km.state == XFRM_STATE_VALID) {
1221                        xfrm[nx++] = x;
1222                        daddr = remote;
1223                        saddr = local;
1224                        continue;
1225                }
1226                if (x) {
1227                        error = (x->km.state == XFRM_STATE_ERROR ?
1228                                 -EINVAL : -EAGAIN);
1229                        xfrm_state_put(x);
1230                }
1231                else if (error == -ESRCH)
1232                        error = -EAGAIN;
1233
1234                if (!tmpl->optional)
1235                        goto fail;
1236        }
1237        return nx;
1238
1239fail:
1240        for (nx--; nx>=0; nx--)
1241                xfrm_state_put(xfrm[nx]);
1242        return error;
1243}
1244
1245static int
1246xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
1247                  struct xfrm_state **xfrm, unsigned short family)
1248{
1249        struct xfrm_state *tp[XFRM_MAX_DEPTH];
1250        struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
1251        int cnx = 0;
1252        int error;
1253        int ret;
1254        int i;
1255
1256        for (i = 0; i < npols; i++) {
1257                if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
1258                        error = -ENOBUFS;
1259                        goto fail;
1260                }
1261
1262                ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
1263                if (ret < 0) {
1264                        error = ret;
1265                        goto fail;
1266                } else
1267                        cnx += ret;
1268        }
1269
1270        /* found states are sorted for outbound processing */
1271        if (npols > 1)
1272                xfrm_state_sort(xfrm, tpp, cnx, family);
1273
1274        return cnx;
1275
1276 fail:
1277        for (cnx--; cnx>=0; cnx--)
1278                xfrm_state_put(tpp[cnx]);
1279        return error;
1280
1281}
1282
1283/* Check that the bundle accepts the flow and its components are
1284 * still valid.
1285 */
1286
1287static inline int xfrm_get_tos(const struct flowi *fl, int family)
1288{
1289        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1290        int tos;
1291
1292        if (!afinfo)
1293                return -EINVAL;
1294
1295        tos = afinfo->get_tos(fl);
1296
1297        xfrm_policy_put_afinfo(afinfo);
1298
1299        return tos;
1300}
1301
1302static struct flow_cache_object *xfrm_bundle_flo_get(struct flow_cache_object *flo)
1303{
1304        struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1305        struct dst_entry *dst = &xdst->u.dst;
1306
1307        if (xdst->route == NULL) {
1308                /* Dummy bundle - if it has xfrms we were not
1309                 * able to build bundle as template resolution failed.
1310                 * It means we need to try again resolving. */
1311                if (xdst->num_xfrms > 0)
1312                        return NULL;
1313        } else {
1314                /* Real bundle */
1315                if (stale_bundle(dst))
1316                        return NULL;
1317        }
1318
1319        dst_hold(dst);
1320        return flo;
1321}
1322
1323static int xfrm_bundle_flo_check(struct flow_cache_object *flo)
1324{
1325        struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1326        struct dst_entry *dst = &xdst->u.dst;
1327
1328        if (!xdst->route)
1329                return 0;
1330        if (stale_bundle(dst))
1331                return 0;
1332
1333        return 1;
1334}
1335
1336static void xfrm_bundle_flo_delete(struct flow_cache_object *flo)
1337{
1338        struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1339        struct dst_entry *dst = &xdst->u.dst;
1340
1341        dst_free(dst);
1342}
1343
1344static const struct flow_cache_ops xfrm_bundle_fc_ops = {
1345        .get = xfrm_bundle_flo_get,
1346        .check = xfrm_bundle_flo_check,
1347        .delete = xfrm_bundle_flo_delete,
1348};
1349
1350static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
1351{
1352        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1353        struct dst_ops *dst_ops;
1354        struct xfrm_dst *xdst;
1355
1356        if (!afinfo)
1357                return ERR_PTR(-EINVAL);
1358
1359        switch (family) {
1360        case AF_INET:
1361                dst_ops = &net->xfrm.xfrm4_dst_ops;
1362                break;
1363#if IS_ENABLED(CONFIG_IPV6)
1364        case AF_INET6:
1365                dst_ops = &net->xfrm.xfrm6_dst_ops;
1366                break;
1367#endif
1368        default:
1369                BUG();
1370        }
1371        xdst = dst_alloc(dst_ops, NULL, 0, DST_OBSOLETE_NONE, 0);
1372
1373        if (likely(xdst)) {
1374                struct dst_entry *dst = &xdst->u.dst;
1375
1376                memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst));
1377                xdst->flo.ops = &xfrm_bundle_fc_ops;
1378                if (afinfo->init_dst)
1379                        afinfo->init_dst(net, xdst);
1380        } else
1381                xdst = ERR_PTR(-ENOBUFS);
1382
1383        xfrm_policy_put_afinfo(afinfo);
1384
1385        return xdst;
1386}
1387
1388static inline int xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
1389                                 int nfheader_len)
1390{
1391        struct xfrm_policy_afinfo *afinfo =
1392                xfrm_policy_get_afinfo(dst->ops->family);
1393        int err;
1394
1395        if (!afinfo)
1396                return -EINVAL;
1397
1398        err = afinfo->init_path(path, dst, nfheader_len);
1399
1400        xfrm_policy_put_afinfo(afinfo);
1401
1402        return err;
1403}
1404
1405static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
1406                                const struct flowi *fl)
1407{
1408        struct xfrm_policy_afinfo *afinfo =
1409                xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
1410        int err;
1411
1412        if (!afinfo)
1413                return -EINVAL;
1414
1415        err = afinfo->fill_dst(xdst, dev, fl);
1416
1417        xfrm_policy_put_afinfo(afinfo);
1418
1419        return err;
1420}
1421
1422
1423/* Allocate chain of dst_entry's, attach known xfrm's, calculate
1424 * all the metrics... Shortly, bundle a bundle.
1425 */
1426
1427static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
1428                                            struct xfrm_state **xfrm, int nx,
1429                                            const struct flowi *fl,
1430                                            struct dst_entry *dst)
1431{
1432        struct net *net = xp_net(policy);
1433        unsigned long now = jiffies;
1434        struct net_device *dev;
1435        struct xfrm_mode *inner_mode;
1436        struct dst_entry *dst_prev = NULL;
1437        struct dst_entry *dst0 = NULL;
1438        int i = 0;
1439        int err;
1440        int header_len = 0;
1441        int nfheader_len = 0;
1442        int trailer_len = 0;
1443        int tos;
1444        int family = policy->selector.family;
1445        xfrm_address_t saddr, daddr;
1446
1447        xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
1448
1449        tos = xfrm_get_tos(fl, family);
1450        err = tos;
1451        if (tos < 0)
1452                goto put_states;
1453
1454        dst_hold(dst);
1455
1456        for (; i < nx; i++) {
1457                struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
1458                struct dst_entry *dst1 = &xdst->u.dst;
1459
1460                err = PTR_ERR(xdst);
1461                if (IS_ERR(xdst)) {
1462                        dst_release(dst);
1463                        goto put_states;
1464                }
1465
1466                if (xfrm[i]->sel.family == AF_UNSPEC) {
1467                        inner_mode = xfrm_ip2inner_mode(xfrm[i],
1468                                                        xfrm_af2proto(family));
1469                        if (!inner_mode) {
1470                                err = -EAFNOSUPPORT;
1471                                dst_release(dst);
1472                                goto put_states;
1473                        }
1474                } else
1475                        inner_mode = xfrm[i]->inner_mode;
1476
1477                if (!dst_prev)
1478                        dst0 = dst1;
1479                else {
1480                        dst_prev->child = dst_clone(dst1);
1481                        dst1->flags |= DST_NOHASH;
1482                }
1483
1484                xdst->route = dst;
1485                dst_copy_metrics(dst1, dst);
1486
1487                if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
1488                        family = xfrm[i]->props.family;
1489                        dst = xfrm_dst_lookup(xfrm[i], tos, &saddr, &daddr,
1490                                              family);
1491                        err = PTR_ERR(dst);
1492                        if (IS_ERR(dst))
1493                                goto put_states;
1494                } else
1495                        dst_hold(dst);
1496
1497                dst1->xfrm = xfrm[i];
1498                xdst->xfrm_genid = xfrm[i]->genid;
1499
1500                dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
1501                dst1->flags |= DST_HOST;
1502                dst1->lastuse = now;
1503
1504                dst1->input = dst_discard;
1505                dst1->output = inner_mode->afinfo->output;
1506
1507                dst1->next = dst_prev;
1508                dst_prev = dst1;
1509
1510                header_len += xfrm[i]->props.header_len;
1511                if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
1512                        nfheader_len += xfrm[i]->props.header_len;
1513                trailer_len += xfrm[i]->props.trailer_len;
1514        }
1515
1516        dst_prev->child = dst;
1517        dst0->path = dst;
1518
1519        err = -ENODEV;
1520        dev = dst->dev;
1521        if (!dev)
1522                goto free_dst;
1523
1524        xfrm_init_path((struct xfrm_dst *)dst0, dst, nfheader_len);
1525        xfrm_init_pmtu(dst_prev);
1526
1527        for (dst_prev = dst0; dst_prev != dst; dst_prev = dst_prev->child) {
1528                struct xfrm_dst *xdst = (struct xfrm_dst *)dst_prev;
1529
1530                err = xfrm_fill_dst(xdst, dev, fl);
1531                if (err)
1532                        goto free_dst;
1533
1534                dst_prev->header_len = header_len;
1535                dst_prev->trailer_len = trailer_len;
1536                header_len -= xdst->u.dst.xfrm->props.header_len;
1537                trailer_len -= xdst->u.dst.xfrm->props.trailer_len;
1538        }
1539
1540out:
1541        return dst0;
1542
1543put_states:
1544        for (; i < nx; i++)
1545                xfrm_state_put(xfrm[i]);
1546free_dst:
1547        if (dst0)
1548                dst_free(dst0);
1549        dst0 = ERR_PTR(err);
1550        goto out;
1551}
1552
1553static int inline
1554xfrm_dst_alloc_copy(void **target, const void *src, int size)
1555{
1556        if (!*target) {
1557                *target = kmalloc(size, GFP_ATOMIC);
1558                if (!*target)
1559                        return -ENOMEM;
1560        }
1561        memcpy(*target, src, size);
1562        return 0;
1563}
1564
1565static int inline
1566xfrm_dst_update_parent(struct dst_entry *dst, const struct xfrm_selector *sel)
1567{
1568#ifdef CONFIG_XFRM_SUB_POLICY
1569        struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1570        return xfrm_dst_alloc_copy((void **)&(xdst->partner),
1571                                   sel, sizeof(*sel));
1572#else
1573        return 0;
1574#endif
1575}
1576
1577static int inline
1578xfrm_dst_update_origin(struct dst_entry *dst, const struct flowi *fl)
1579{
1580#ifdef CONFIG_XFRM_SUB_POLICY
1581        struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1582        return xfrm_dst_alloc_copy((void **)&(xdst->origin), fl, sizeof(*fl));
1583#else
1584        return 0;
1585#endif
1586}
1587
1588static int xfrm_expand_policies(const struct flowi *fl, u16 family,
1589                                struct xfrm_policy **pols,
1590                                int *num_pols, int *num_xfrms)
1591{
1592        int i;
1593
1594        if (*num_pols == 0 || !pols[0]) {
1595                *num_pols = 0;
1596                *num_xfrms = 0;
1597                return 0;
1598        }
1599        if (IS_ERR(pols[0]))
1600                return PTR_ERR(pols[0]);
1601
1602        *num_xfrms = pols[0]->xfrm_nr;
1603
1604#ifdef CONFIG_XFRM_SUB_POLICY
1605        if (pols[0] && pols[0]->action == XFRM_POLICY_ALLOW &&
1606            pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1607                pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
1608                                                    XFRM_POLICY_TYPE_MAIN,
1609                                                    fl, family,
1610                                                    XFRM_POLICY_OUT);
1611                if (pols[1]) {
1612                        if (IS_ERR(pols[1])) {
1613                                xfrm_pols_put(pols, *num_pols);
1614                                return PTR_ERR(pols[1]);
1615                        }
1616                        (*num_pols) ++;
1617                        (*num_xfrms) += pols[1]->xfrm_nr;
1618                }
1619        }
1620#endif
1621        for (i = 0; i < *num_pols; i++) {
1622                if (pols[i]->action != XFRM_POLICY_ALLOW) {
1623                        *num_xfrms = -1;
1624                        break;
1625                }
1626        }
1627
1628        return 0;
1629
1630}
1631
1632static struct xfrm_dst *
1633xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
1634                               const struct flowi *fl, u16 family,
1635                               struct dst_entry *dst_orig)
1636{
1637        struct net *net = xp_net(pols[0]);
1638        struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
1639        struct dst_entry *dst;
1640        struct xfrm_dst *xdst;
1641        int err;
1642
1643        /* Try to instantiate a bundle */
1644        err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
1645        if (err <= 0) {
1646                if (err != 0 && err != -EAGAIN)
1647                        XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
1648                return ERR_PTR(err);
1649        }
1650
1651        dst = xfrm_bundle_create(pols[0], xfrm, err, fl, dst_orig);
1652        if (IS_ERR(dst)) {
1653                XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
1654                return ERR_CAST(dst);
1655        }
1656
1657        xdst = (struct xfrm_dst *)dst;
1658        xdst->num_xfrms = err;
1659        if (num_pols > 1)
1660                err = xfrm_dst_update_parent(dst, &pols[1]->selector);
1661        else
1662                err = xfrm_dst_update_origin(dst, fl);
1663        if (unlikely(err)) {
1664                dst_free(dst);
1665                XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLECHECKERROR);
1666                return ERR_PTR(err);
1667        }
1668
1669        xdst->num_pols = num_pols;
1670        memcpy(xdst->pols, pols, sizeof(struct xfrm_policy*) * num_pols);
1671        xdst->policy_genid = atomic_read(&pols[0]->genid);
1672
1673        return xdst;
1674}
1675
1676static struct flow_cache_object *
1677xfrm_bundle_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir,
1678                   struct flow_cache_object *oldflo, void *ctx)
1679{
1680        struct dst_entry *dst_orig = (struct dst_entry *)ctx;
1681        struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1682        struct xfrm_dst *xdst, *new_xdst;
1683        int num_pols = 0, num_xfrms = 0, i, err, pol_dead;
1684
1685        /* Check if the policies from old bundle are usable */
1686        xdst = NULL;
1687        if (oldflo) {
1688                xdst = container_of(oldflo, struct xfrm_dst, flo);
1689                num_pols = xdst->num_pols;
1690                num_xfrms = xdst->num_xfrms;
1691                pol_dead = 0;
1692                for (i = 0; i < num_pols; i++) {
1693                        pols[i] = xdst->pols[i];
1694                        pol_dead |= pols[i]->walk.dead;
1695                }
1696                if (pol_dead) {
1697                        dst_free(&xdst->u.dst);
1698                        xdst = NULL;
1699                        num_pols = 0;
1700                        num_xfrms = 0;
1701                        oldflo = NULL;
1702                }
1703        }
1704
1705        /* Resolve policies to use if we couldn't get them from
1706         * previous cache entry */
1707        if (xdst == NULL) {
1708                num_pols = 1;
1709                pols[0] = __xfrm_policy_lookup(net, fl, family, dir);
1710                err = xfrm_expand_policies(fl, family, pols,
1711                                           &num_pols, &num_xfrms);
1712                if (err < 0)
1713                        goto inc_error;
1714                if (num_pols == 0)
1715                        return NULL;
1716                if (num_xfrms <= 0)
1717                        goto make_dummy_bundle;
1718        }
1719
1720        new_xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family, dst_orig);
1721        if (IS_ERR(new_xdst)) {
1722                err = PTR_ERR(new_xdst);
1723                if (err != -EAGAIN)
1724                        goto error;
1725                if (oldflo == NULL)
1726                        goto make_dummy_bundle;
1727                dst_hold(&xdst->u.dst);
1728                return oldflo;
1729        } else if (new_xdst == NULL) {
1730                num_xfrms = 0;
1731                if (oldflo == NULL)
1732                        goto make_dummy_bundle;
1733                xdst->num_xfrms = 0;
1734                dst_hold(&xdst->u.dst);
1735                return oldflo;
1736        }
1737
1738        /* Kill the previous bundle */
1739        if (xdst) {
1740                /* The policies were stolen for newly generated bundle */
1741                xdst->num_pols = 0;
1742                dst_free(&xdst->u.dst);
1743        }
1744
1745        /* Flow cache does not have reference, it dst_free()'s,
1746         * but we do need to return one reference for original caller */
1747        dst_hold(&new_xdst->u.dst);
1748        return &new_xdst->flo;
1749
1750make_dummy_bundle:
1751        /* We found policies, but there's no bundles to instantiate:
1752         * either because the policy blocks, has no transformations or
1753         * we could not build template (no xfrm_states).*/
1754        xdst = xfrm_alloc_dst(net, family);
1755        if (IS_ERR(xdst)) {
1756                xfrm_pols_put(pols, num_pols);
1757                return ERR_CAST(xdst);
1758        }
1759        xdst->num_pols = num_pols;
1760        xdst->num_xfrms = num_xfrms;
1761        memcpy(xdst->pols, pols, sizeof(struct xfrm_policy*) * num_pols);
1762
1763        dst_hold(&xdst->u.dst);
1764        return &xdst->flo;
1765
1766inc_error:
1767        XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
1768error:
1769        if (xdst != NULL)
1770                dst_free(&xdst->u.dst);
1771        else
1772                xfrm_pols_put(pols, num_pols);
1773        return ERR_PTR(err);
1774}
1775
1776static struct dst_entry *make_blackhole(struct net *net, u16 family,
1777                                        struct dst_entry *dst_orig)
1778{
1779        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1780        struct dst_entry *ret;
1781
1782        if (!afinfo) {
1783                dst_release(dst_orig);
1784                return ERR_PTR(-EINVAL);
1785        } else {
1786                ret = afinfo->blackhole_route(net, dst_orig);
1787        }
1788        xfrm_policy_put_afinfo(afinfo);
1789
1790        return ret;
1791}
1792
1793/* Main function: finds/creates a bundle for given flow.
1794 *
1795 * At the moment we eat a raw IP route. Mostly to speed up lookups
1796 * on interfaces with disabled IPsec.
1797 */
1798struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
1799                              const struct flowi *fl,
1800                              struct sock *sk, int flags)
1801{
1802        struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1803        struct flow_cache_object *flo;
1804        struct xfrm_dst *xdst;
1805        struct dst_entry *dst, *route;
1806        u16 family = dst_orig->ops->family;
1807        u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
1808        int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
1809
1810restart:
1811        dst = NULL;
1812        xdst = NULL;
1813        route = NULL;
1814
1815        if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
1816                num_pols = 1;
1817                pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
1818                err = xfrm_expand_policies(fl, family, pols,
1819                                           &num_pols, &num_xfrms);
1820                if (err < 0)
1821                        goto dropdst;
1822
1823                if (num_pols) {
1824                        if (num_xfrms <= 0) {
1825                                drop_pols = num_pols;
1826                                goto no_transform;
1827                        }
1828
1829                        xdst = xfrm_resolve_and_create_bundle(
1830                                        pols, num_pols, fl,
1831                                        family, dst_orig);
1832                        if (IS_ERR(xdst)) {
1833                                xfrm_pols_put(pols, num_pols);
1834                                err = PTR_ERR(xdst);
1835                                goto dropdst;
1836                        } else if (xdst == NULL) {
1837                                num_xfrms = 0;
1838                                drop_pols = num_pols;
1839                                goto no_transform;
1840                        }
1841
1842                        dst_hold(&xdst->u.dst);
1843
1844                        spin_lock_bh(&xfrm_policy_sk_bundle_lock);
1845                        xdst->u.dst.next = xfrm_policy_sk_bundles;
1846                        xfrm_policy_sk_bundles = &xdst->u.dst;
1847                        spin_unlock_bh(&xfrm_policy_sk_bundle_lock);
1848
1849                        route = xdst->route;
1850                }
1851        }
1852
1853        if (xdst == NULL) {
1854                /* To accelerate a bit...  */
1855                if ((dst_orig->flags & DST_NOXFRM) ||
1856                    !net->xfrm.policy_count[XFRM_POLICY_OUT])
1857                        goto nopol;
1858
1859                flo = flow_cache_lookup(net, fl, family, dir,
1860                                        xfrm_bundle_lookup, dst_orig);
1861                if (flo == NULL)
1862                        goto nopol;
1863                if (IS_ERR(flo)) {
1864                        err = PTR_ERR(flo);
1865                        goto dropdst;
1866                }
1867                xdst = container_of(flo, struct xfrm_dst, flo);
1868
1869                num_pols = xdst->num_pols;
1870                num_xfrms = xdst->num_xfrms;
1871                memcpy(pols, xdst->pols, sizeof(struct xfrm_policy*) * num_pols);
1872                route = xdst->route;
1873        }
1874
1875        dst = &xdst->u.dst;
1876        if (route == NULL && num_xfrms > 0) {
1877                /* The only case when xfrm_bundle_lookup() returns a
1878                 * bundle with null route, is when the template could
1879                 * not be resolved. It means policies are there, but
1880                 * bundle could not be created, since we don't yet
1881                 * have the xfrm_state's. We need to wait for KM to
1882                 * negotiate new SA's or bail out with error.*/
1883                if (net->xfrm.sysctl_larval_drop) {
1884                        /* EREMOTE tells the caller to generate
1885                         * a one-shot blackhole route. */
1886                        dst_release(dst);
1887                        xfrm_pols_put(pols, drop_pols);
1888                        XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
1889
1890                        return make_blackhole(net, family, dst_orig);
1891                }
1892                if (fl->flowi_flags & FLOWI_FLAG_CAN_SLEEP) {
1893                        DECLARE_WAITQUEUE(wait, current);
1894
1895                        add_wait_queue(&net->xfrm.km_waitq, &wait);
1896                        set_current_state(TASK_INTERRUPTIBLE);
1897                        schedule();
1898                        set_current_state(TASK_RUNNING);
1899                        remove_wait_queue(&net->xfrm.km_waitq, &wait);
1900
1901                        if (!signal_pending(current)) {
1902                                dst_release(dst);
1903                                goto restart;
1904                        }
1905
1906                        err = -ERESTART;
1907                } else
1908                        err = -EAGAIN;
1909
1910                XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
1911                goto error;
1912        }
1913
1914no_transform:
1915        if (num_pols == 0)
1916                goto nopol;
1917
1918        if ((flags & XFRM_LOOKUP_ICMP) &&
1919            !(pols[0]->flags & XFRM_POLICY_ICMP)) {
1920                err = -ENOENT;
1921                goto error;
1922        }
1923
1924        for (i = 0; i < num_pols; i++)
1925                pols[i]->curlft.use_time = get_seconds();
1926
1927        if (num_xfrms < 0) {
1928                /* Prohibit the flow */
1929                XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
1930                err = -EPERM;
1931                goto error;
1932        } else if (num_xfrms > 0) {
1933                /* Flow transformed */
1934                dst_release(dst_orig);
1935        } else {
1936                /* Flow passes untransformed */
1937                dst_release(dst);
1938                dst = dst_orig;
1939        }
1940ok:
1941        xfrm_pols_put(pols, drop_pols);
1942        if (dst && dst->xfrm &&
1943            dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
1944                dst->flags |= DST_XFRM_TUNNEL;
1945        return dst;
1946
1947nopol:
1948        if (!(flags & XFRM_LOOKUP_ICMP)) {
1949                dst = dst_orig;
1950                goto ok;
1951        }
1952        err = -ENOENT;
1953error:
1954        dst_release(dst);
1955dropdst:
1956        dst_release(dst_orig);
1957        xfrm_pols_put(pols, drop_pols);
1958        return ERR_PTR(err);
1959}
1960EXPORT_SYMBOL(xfrm_lookup);
1961
1962static inline int
1963xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl)
1964{
1965        struct xfrm_state *x;
1966
1967        if (!skb->sp || idx < 0 || idx >= skb->sp->len)
1968                return 0;
1969        x = skb->sp->xvec[idx];
1970        if (!x->type->reject)
1971                return 0;
1972        return x->type->reject(x, skb, fl);
1973}
1974
1975/* When skb is transformed back to its "native" form, we have to
1976 * check policy restrictions. At the moment we make this in maximally
1977 * stupid way. Shame on me. :-) Of course, connected sockets must
1978 * have policy cached at them.
1979 */
1980
1981static inline int
1982xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x,
1983              unsigned short family)
1984{
1985        if (xfrm_state_kern(x))
1986                return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
1987        return  x->id.proto == tmpl->id.proto &&
1988                (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
1989                (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
1990                x->props.mode == tmpl->mode &&
1991                (tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
1992                 !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
1993                !(x->props.mode != XFRM_MODE_TRANSPORT &&
1994                  xfrm_state_addr_cmp(tmpl, x, family));
1995}
1996
1997/*
1998 * 0 or more than 0 is returned when validation is succeeded (either bypass
1999 * because of optional transport mode, or next index of the mathced secpath
2000 * state with the template.
2001 * -1 is returned when no matching template is found.
2002 * Otherwise "-2 - errored_index" is returned.
2003 */
2004static inline int
2005xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start,
2006               unsigned short family)
2007{
2008        int idx = start;
2009
2010        if (tmpl->optional) {
2011                if (tmpl->mode == XFRM_MODE_TRANSPORT)
2012                        return start;
2013        } else
2014                start = -1;
2015        for (; idx < sp->len; idx++) {
2016                if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
2017                        return ++idx;
2018                if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
2019                        if (start == -1)
2020                                start = -2-idx;
2021                        break;
2022                }
2023        }
2024        return start;
2025}
2026
2027int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
2028                          unsigned int family, int reverse)
2029{
2030        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2031        int err;
2032
2033        if (unlikely(afinfo == NULL))
2034                return -EAFNOSUPPORT;
2035
2036        afinfo->decode_session(skb, fl, reverse);
2037        err = security_xfrm_decode_session(skb, &fl->flowi_secid);
2038        xfrm_policy_put_afinfo(afinfo);
2039        return err;
2040}
2041EXPORT_SYMBOL(__xfrm_decode_session);
2042
2043static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
2044{
2045        for (; k < sp->len; k++) {
2046                if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
2047                        *idxp = k;
2048                        return 1;
2049                }
2050        }
2051
2052        return 0;
2053}
2054
2055int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
2056                        unsigned short family)
2057{
2058        struct net *net = dev_net(skb->dev);
2059        struct xfrm_policy *pol;
2060        struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2061        int npols = 0;
2062        int xfrm_nr;
2063        int pi;
2064        int reverse;
2065        struct flowi fl;
2066        u8 fl_dir;
2067        int xerr_idx = -1;
2068
2069        reverse = dir & ~XFRM_POLICY_MASK;
2070        dir &= XFRM_POLICY_MASK;
2071        fl_dir = policy_to_flow_dir(dir);
2072
2073        if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) {
2074                XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
2075                return 0;
2076        }
2077
2078        nf_nat_decode_session(skb, &fl, family);
2079
2080        /* First, check used SA against their selectors. */
2081        if (skb->sp) {
2082                int i;
2083
2084                for (i=skb->sp->len-1; i>=0; i--) {
2085                        struct xfrm_state *x = skb->sp->xvec[i];
2086                        if (!xfrm_selector_match(&x->sel, &fl, family)) {
2087                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
2088                                return 0;
2089                        }
2090                }
2091        }
2092
2093        pol = NULL;
2094        if (sk && sk->sk_policy[dir]) {
2095                pol = xfrm_sk_policy_lookup(sk, dir, &fl);
2096                if (IS_ERR(pol)) {
2097                        XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2098                        return 0;
2099                }
2100        }
2101
2102        if (!pol) {
2103                struct flow_cache_object *flo;
2104
2105                flo = flow_cache_lookup(net, &fl, family, fl_dir,
2106                                        xfrm_policy_lookup, NULL);
2107                if (IS_ERR_OR_NULL(flo))
2108                        pol = ERR_CAST(flo);
2109                else
2110                        pol = container_of(flo, struct xfrm_policy, flo);
2111        }
2112
2113        if (IS_ERR(pol)) {
2114                XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2115                return 0;
2116        }
2117
2118        if (!pol) {
2119                if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
2120                        xfrm_secpath_reject(xerr_idx, skb, &fl);
2121                        XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
2122                        return 0;
2123                }
2124                return 1;
2125        }
2126
2127        pol->curlft.use_time = get_seconds();
2128
2129        pols[0] = pol;
2130        npols ++;
2131#ifdef CONFIG_XFRM_SUB_POLICY
2132        if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2133                pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
2134                                                    &fl, family,
2135                                                    XFRM_POLICY_IN);
2136                if (pols[1]) {
2137                        if (IS_ERR(pols[1])) {
2138                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2139                                return 0;
2140                        }
2141                        pols[1]->curlft.use_time = get_seconds();
2142                        npols ++;
2143                }
2144        }
2145#endif
2146
2147        if (pol->action == XFRM_POLICY_ALLOW) {
2148                struct sec_path *sp;
2149                static struct sec_path dummy;
2150                struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
2151                struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
2152                struct xfrm_tmpl **tpp = tp;
2153                int ti = 0;
2154                int i, k;
2155
2156                if ((sp = skb->sp) == NULL)
2157                        sp = &dummy;
2158
2159                for (pi = 0; pi < npols; pi++) {
2160                        if (pols[pi] != pol &&
2161                            pols[pi]->action != XFRM_POLICY_ALLOW) {
2162                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2163                                goto reject;
2164                        }
2165                        if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
2166                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
2167                                goto reject_error;
2168                        }
2169                        for (i = 0; i < pols[pi]->xfrm_nr; i++)
2170                                tpp[ti++] = &pols[pi]->xfrm_vec[i];
2171                }
2172                xfrm_nr = ti;
2173                if (npols > 1) {
2174                        xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
2175                        tpp = stp;
2176                }
2177
2178                /* For each tunnel xfrm, find the first matching tmpl.
2179                 * For each tmpl before that, find corresponding xfrm.
2180                 * Order is _important_. Later we will implement
2181                 * some barriers, but at the moment barriers
2182                 * are implied between each two transformations.
2183                 */
2184                for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
2185                        k = xfrm_policy_ok(tpp[i], sp, k, family);
2186                        if (k < 0) {
2187                                if (k < -1)
2188                                        /* "-2 - errored_index" returned */
2189                                        xerr_idx = -(2+k);
2190                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2191                                goto reject;
2192                        }
2193                }
2194
2195                if (secpath_has_nontransport(sp, k, &xerr_idx)) {
2196                        XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2197                        goto reject;
2198                }
2199
2200                xfrm_pols_put(pols, npols);
2201                return 1;
2202        }
2203        XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2204
2205reject:
2206        xfrm_secpath_reject(xerr_idx, skb, &fl);
2207reject_error:
2208        xfrm_pols_put(pols, npols);
2209        return 0;
2210}
2211EXPORT_SYMBOL(__xfrm_policy_check);
2212
2213int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
2214{
2215        struct net *net = dev_net(skb->dev);
2216        struct flowi fl;
2217        struct dst_entry *dst;
2218        int res = 1;
2219
2220        if (xfrm_decode_session(skb, &fl, family) < 0) {
2221                XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
2222                return 0;
2223        }
2224
2225        skb_dst_force(skb);
2226
2227        dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, 0);
2228        if (IS_ERR(dst)) {
2229                res = 0;
2230                dst = NULL;
2231        }
2232        skb_dst_set(skb, dst);
2233        return res;
2234}
2235EXPORT_SYMBOL(__xfrm_route_forward);
2236
2237/* Optimize later using cookies and generation ids. */
2238
2239static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
2240{
2241        /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
2242         * to DST_OBSOLETE_FORCE_CHK to force all XFRM destinations to
2243         * get validated by dst_ops->check on every use.  We do this
2244         * because when a normal route referenced by an XFRM dst is
2245         * obsoleted we do not go looking around for all parent
2246         * referencing XFRM dsts so that we can invalidate them.  It
2247         * is just too much work.  Instead we make the checks here on
2248         * every use.  For example:
2249         *
2250         *      XFRM dst A --> IPv4 dst X
2251         *
2252         * X is the "xdst->route" of A (X is also the "dst->path" of A
2253         * in this example).  If X is marked obsolete, "A" will not
2254         * notice.  That's what we are validating here via the
2255         * stale_bundle() check.
2256         *
2257         * When a policy's bundle is pruned, we dst_free() the XFRM
2258         * dst which causes it's ->obsolete field to be set to
2259         * DST_OBSOLETE_DEAD.  If an XFRM dst has been pruned like
2260         * this, we want to force a new route lookup.
2261         */
2262        if (dst->obsolete < 0 && !stale_bundle(dst))
2263                return dst;
2264
2265        return NULL;
2266}
2267
2268static int stale_bundle(struct dst_entry *dst)
2269{
2270        return !xfrm_bundle_ok((struct xfrm_dst *)dst);
2271}
2272
2273void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
2274{
2275        while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
2276                dst->dev = dev_net(dev)->loopback_dev;
2277                dev_hold(dst->dev);
2278                dev_put(dev);
2279        }
2280}
2281EXPORT_SYMBOL(xfrm_dst_ifdown);
2282
2283static void xfrm_link_failure(struct sk_buff *skb)
2284{
2285        /* Impossible. Such dst must be popped before reaches point of failure. */
2286}
2287
2288static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
2289{
2290        if (dst) {
2291                if (dst->obsolete) {
2292                        dst_release(dst);
2293                        dst = NULL;
2294                }
2295        }
2296        return dst;
2297}
2298
2299static void __xfrm_garbage_collect(struct net *net)
2300{
2301        struct dst_entry *head, *next;
2302
2303        spin_lock_bh(&xfrm_policy_sk_bundle_lock);
2304        head = xfrm_policy_sk_bundles;
2305        xfrm_policy_sk_bundles = NULL;
2306        spin_unlock_bh(&xfrm_policy_sk_bundle_lock);
2307
2308        while (head) {
2309                next = head->next;
2310                dst_free(head);
2311                head = next;
2312        }
2313}
2314
2315static void xfrm_garbage_collect(struct net *net)
2316{
2317        flow_cache_flush();
2318        __xfrm_garbage_collect(net);
2319}
2320
2321static void xfrm_garbage_collect_deferred(struct net *net)
2322{
2323        flow_cache_flush_deferred();
2324        __xfrm_garbage_collect(net);
2325}
2326
2327static void xfrm_init_pmtu(struct dst_entry *dst)
2328{
2329        do {
2330                struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2331                u32 pmtu, route_mtu_cached;
2332
2333                pmtu = dst_mtu(dst->child);
2334                xdst->child_mtu_cached = pmtu;
2335
2336                pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
2337
2338                route_mtu_cached = dst_mtu(xdst->route);
2339                xdst->route_mtu_cached = route_mtu_cached;
2340
2341                if (pmtu > route_mtu_cached)
2342                        pmtu = route_mtu_cached;
2343
2344                dst_metric_set(dst, RTAX_MTU, pmtu);
2345        } while ((dst = dst->next));
2346}
2347
2348/* Check that the bundle accepts the flow and its components are
2349 * still valid.
2350 */
2351
2352static int xfrm_bundle_ok(struct xfrm_dst *first)
2353{
2354        struct dst_entry *dst = &first->u.dst;
2355        struct xfrm_dst *last;
2356        u32 mtu;
2357
2358        if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
2359            (dst->dev && !netif_running(dst->dev)))
2360                return 0;
2361
2362        last = NULL;
2363
2364        do {
2365                struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2366
2367                if (dst->xfrm->km.state != XFRM_STATE_VALID)
2368                        return 0;
2369                if (xdst->xfrm_genid != dst->xfrm->genid)
2370                        return 0;
2371                if (xdst->num_pols > 0 &&
2372                    xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
2373                        return 0;
2374
2375                mtu = dst_mtu(dst->child);
2376                if (xdst->child_mtu_cached != mtu) {
2377                        last = xdst;
2378                        xdst->child_mtu_cached = mtu;
2379                }
2380
2381                if (!dst_check(xdst->route, xdst->route_cookie))
2382                        return 0;
2383                mtu = dst_mtu(xdst->route);
2384                if (xdst->route_mtu_cached != mtu) {
2385                        last = xdst;
2386                        xdst->route_mtu_cached = mtu;
2387                }
2388
2389                dst = dst->child;
2390        } while (dst->xfrm);
2391
2392        if (likely(!last))
2393                return 1;
2394
2395        mtu = last->child_mtu_cached;
2396        for (;;) {
2397                dst = &last->u.dst;
2398
2399                mtu = xfrm_state_mtu(dst->xfrm, mtu);
2400                if (mtu > last->route_mtu_cached)
2401                        mtu = last->route_mtu_cached;
2402                dst_metric_set(dst, RTAX_MTU, mtu);
2403
2404                if (last == first)
2405                        break;
2406
2407                last = (struct xfrm_dst *)last->u.dst.next;
2408                last->child_mtu_cached = mtu;
2409        }
2410
2411        return 1;
2412}
2413
2414static unsigned int xfrm_default_advmss(const struct dst_entry *dst)
2415{
2416        return dst_metric_advmss(dst->path);
2417}
2418
2419static unsigned int xfrm_mtu(const struct dst_entry *dst)
2420{
2421        unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2422
2423        return mtu ? : dst_mtu(dst->path);
2424}
2425
2426static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst,
2427                                           struct sk_buff *skb,
2428                                           const void *daddr)
2429{
2430        return dst->path->ops->neigh_lookup(dst, skb, daddr);
2431}
2432
2433int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
2434{
2435        struct net *net;
2436        int err = 0;
2437        if (unlikely(afinfo == NULL))
2438                return -EINVAL;
2439        if (unlikely(afinfo->family >= NPROTO))
2440                return -EAFNOSUPPORT;
2441        spin_lock(&xfrm_policy_afinfo_lock);
2442        if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
2443                err = -ENOBUFS;
2444        else {
2445                struct dst_ops *dst_ops = afinfo->dst_ops;
2446                if (likely(dst_ops->kmem_cachep == NULL))
2447                        dst_ops->kmem_cachep = xfrm_dst_cache;
2448                if (likely(dst_ops->check == NULL))
2449                        dst_ops->check = xfrm_dst_check;
2450                if (likely(dst_ops->default_advmss == NULL))
2451                        dst_ops->default_advmss = xfrm_default_advmss;
2452                if (likely(dst_ops->mtu == NULL))
2453                        dst_ops->mtu = xfrm_mtu;
2454                if (likely(dst_ops->negative_advice == NULL))
2455                        dst_ops->negative_advice = xfrm_negative_advice;
2456                if (likely(dst_ops->link_failure == NULL))
2457                        dst_ops->link_failure = xfrm_link_failure;
2458                if (likely(dst_ops->neigh_lookup == NULL))
2459                        dst_ops->neigh_lookup = xfrm_neigh_lookup;
2460                if (likely(afinfo->garbage_collect == NULL))
2461                        afinfo->garbage_collect = xfrm_garbage_collect_deferred;
2462                rcu_assign_pointer(xfrm_policy_afinfo[afinfo->family], afinfo);
2463        }
2464        spin_unlock(&xfrm_policy_afinfo_lock);
2465
2466        rtnl_lock();
2467        for_each_net(net) {
2468                struct dst_ops *xfrm_dst_ops;
2469
2470                switch (afinfo->family) {
2471                case AF_INET:
2472                        xfrm_dst_ops = &net->xfrm.xfrm4_dst_ops;
2473                        break;
2474#if IS_ENABLED(CONFIG_IPV6)
2475                case AF_INET6:
2476                        xfrm_dst_ops = &net->xfrm.xfrm6_dst_ops;
2477                        break;
2478#endif
2479                default:
2480                        BUG();
2481                }
2482                *xfrm_dst_ops = *afinfo->dst_ops;
2483        }
2484        rtnl_unlock();
2485
2486        return err;
2487}
2488EXPORT_SYMBOL(xfrm_policy_register_afinfo);
2489
2490int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
2491{
2492        int err = 0;
2493        if (unlikely(afinfo == NULL))
2494                return -EINVAL;
2495        if (unlikely(afinfo->family >= NPROTO))
2496                return -EAFNOSUPPORT;
2497        spin_lock(&xfrm_policy_afinfo_lock);
2498        if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
2499                if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
2500                        err = -EINVAL;
2501                else
2502                        RCU_INIT_POINTER(xfrm_policy_afinfo[afinfo->family],
2503                                         NULL);
2504        }
2505        spin_unlock(&xfrm_policy_afinfo_lock);
2506        if (!err) {
2507                struct dst_ops *dst_ops = afinfo->dst_ops;
2508
2509                synchronize_rcu();
2510
2511                dst_ops->kmem_cachep = NULL;
2512                dst_ops->check = NULL;
2513                dst_ops->negative_advice = NULL;
2514                dst_ops->link_failure = NULL;
2515                afinfo->garbage_collect = NULL;
2516        }
2517        return err;
2518}
2519EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
2520
2521static void __net_init xfrm_dst_ops_init(struct net *net)
2522{
2523        struct xfrm_policy_afinfo *afinfo;
2524
2525        rcu_read_lock();
2526        afinfo = rcu_dereference(xfrm_policy_afinfo[AF_INET]);
2527        if (afinfo)
2528                net->xfrm.xfrm4_dst_ops = *afinfo->dst_ops;
2529#if IS_ENABLED(CONFIG_IPV6)
2530        afinfo = rcu_dereference(xfrm_policy_afinfo[AF_INET6]);
2531        if (afinfo)
2532                net->xfrm.xfrm6_dst_ops = *afinfo->dst_ops;
2533#endif
2534        rcu_read_unlock();
2535}
2536
2537static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
2538{
2539        struct net_device *dev = ptr;
2540
2541        switch (event) {
2542        case NETDEV_DOWN:
2543                xfrm_garbage_collect(dev_net(dev));
2544        }
2545        return NOTIFY_DONE;
2546}
2547
2548static struct notifier_block xfrm_dev_notifier = {
2549        .notifier_call  = xfrm_dev_event,
2550};
2551
2552#ifdef CONFIG_XFRM_STATISTICS
2553static int __net_init xfrm_statistics_init(struct net *net)
2554{
2555        int rv;
2556
2557        if (snmp_mib_init((void __percpu **)net->mib.xfrm_statistics,
2558                          sizeof(struct linux_xfrm_mib),
2559                          __alignof__(struct linux_xfrm_mib)) < 0)
2560                return -ENOMEM;
2561        rv = xfrm_proc_init(net);
2562        if (rv < 0)
2563                snmp_mib_free((void __percpu **)net->mib.xfrm_statistics);
2564        return rv;
2565}
2566
2567static void xfrm_statistics_fini(struct net *net)
2568{
2569        xfrm_proc_fini(net);
2570        snmp_mib_free((void __percpu **)net->mib.xfrm_statistics);
2571}
2572#else
2573static int __net_init xfrm_statistics_init(struct net *net)
2574{
2575        return 0;
2576}
2577
2578static void xfrm_statistics_fini(struct net *net)
2579{
2580}
2581#endif
2582
2583static int __net_init xfrm_policy_init(struct net *net)
2584{
2585        unsigned int hmask, sz;
2586        int dir;
2587
2588        if (net_eq(net, &init_net))
2589                xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
2590                                           sizeof(struct xfrm_dst),
2591                                           0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
2592                                           NULL);
2593
2594        hmask = 8 - 1;
2595        sz = (hmask+1) * sizeof(struct hlist_head);
2596
2597        net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
2598        if (!net->xfrm.policy_byidx)
2599                goto out_byidx;
2600        net->xfrm.policy_idx_hmask = hmask;
2601
2602        for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
2603                struct xfrm_policy_hash *htab;
2604
2605                net->xfrm.policy_count[dir] = 0;
2606                INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
2607
2608                htab = &net->xfrm.policy_bydst[dir];
2609                htab->table = xfrm_hash_alloc(sz);
2610                if (!htab->table)
2611                        goto out_bydst;
2612                htab->hmask = hmask;
2613        }
2614
2615        INIT_LIST_HEAD(&net->xfrm.policy_all);
2616        INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
2617        if (net_eq(net, &init_net))
2618                register_netdevice_notifier(&xfrm_dev_notifier);
2619        return 0;
2620
2621out_bydst:
2622        for (dir--; dir >= 0; dir--) {
2623                struct xfrm_policy_hash *htab;
2624
2625                htab = &net->xfrm.policy_bydst[dir];
2626                xfrm_hash_free(htab->table, sz);
2627        }
2628        xfrm_hash_free(net->xfrm.policy_byidx, sz);
2629out_byidx:
2630        return -ENOMEM;
2631}
2632
2633static void xfrm_policy_fini(struct net *net)
2634{
2635        struct xfrm_audit audit_info;
2636        unsigned int sz;
2637        int dir;
2638
2639        flush_work(&net->xfrm.policy_hash_work);
2640#ifdef CONFIG_XFRM_SUB_POLICY
2641        audit_info.loginuid = INVALID_UID;
2642        audit_info.sessionid = -1;
2643        audit_info.secid = 0;
2644        xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, &audit_info);
2645#endif
2646        audit_info.loginuid = INVALID_UID;
2647        audit_info.sessionid = -1;
2648        audit_info.secid = 0;
2649        xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, &audit_info);
2650
2651        WARN_ON(!list_empty(&net->xfrm.policy_all));
2652
2653        for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
2654                struct xfrm_policy_hash *htab;
2655
2656                WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
2657
2658                htab = &net->xfrm.policy_bydst[dir];
2659                sz = (htab->hmask + 1);
2660                WARN_ON(!hlist_empty(htab->table));
2661                xfrm_hash_free(htab->table, sz);
2662        }
2663
2664        sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
2665        WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
2666        xfrm_hash_free(net->xfrm.policy_byidx, sz);
2667}
2668
2669static int __net_init xfrm_net_init(struct net *net)
2670{
2671        int rv;
2672
2673        rv = xfrm_statistics_init(net);
2674        if (rv < 0)
2675                goto out_statistics;
2676        rv = xfrm_state_init(net);
2677        if (rv < 0)
2678                goto out_state;
2679        rv = xfrm_policy_init(net);
2680        if (rv < 0)
2681                goto out_policy;
2682        xfrm_dst_ops_init(net);
2683        rv = xfrm_sysctl_init(net);
2684        if (rv < 0)
2685                goto out_sysctl;
2686        return 0;
2687
2688out_sysctl:
2689        xfrm_policy_fini(net);
2690out_policy:
2691        xfrm_state_fini(net);
2692out_state:
2693        xfrm_statistics_fini(net);
2694out_statistics:
2695        return rv;
2696}
2697
2698static void __net_exit xfrm_net_exit(struct net *net)
2699{
2700        xfrm_sysctl_fini(net);
2701        xfrm_policy_fini(net);
2702        xfrm_state_fini(net);
2703        xfrm_statistics_fini(net);
2704}
2705
2706static struct pernet_operations __net_initdata xfrm_net_ops = {
2707        .init = xfrm_net_init,
2708        .exit = xfrm_net_exit,
2709};
2710
2711void __init xfrm_init(void)
2712{
2713        register_pernet_subsys(&xfrm_net_ops);
2714        xfrm_input_init();
2715}
2716
2717#ifdef CONFIG_AUDITSYSCALL
2718static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
2719                                         struct audit_buffer *audit_buf)
2720{
2721        struct xfrm_sec_ctx *ctx = xp->security;
2722        struct xfrm_selector *sel = &xp->selector;
2723
2724        if (ctx)
2725                audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
2726                                 ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
2727
2728        switch(sel->family) {
2729        case AF_INET:
2730                audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
2731                if (sel->prefixlen_s != 32)
2732                        audit_log_format(audit_buf, " src_prefixlen=%d",
2733                                         sel->prefixlen_s);
2734                audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
2735                if (sel->prefixlen_d != 32)
2736                        audit_log_format(audit_buf, " dst_prefixlen=%d",
2737                                         sel->prefixlen_d);
2738                break;
2739        case AF_INET6:
2740                audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
2741                if (sel->prefixlen_s != 128)
2742                        audit_log_format(audit_buf, " src_prefixlen=%d",
2743                                         sel->prefixlen_s);
2744                audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
2745                if (sel->prefixlen_d != 128)
2746                        audit_log_format(audit_buf, " dst_prefixlen=%d",
2747                                         sel->prefixlen_d);
2748                break;
2749        }
2750}
2751
2752void xfrm_audit_policy_add(struct xfrm_policy *xp, int result,
2753                           kuid_t auid, u32 sessionid, u32 secid)
2754{
2755        struct audit_buffer *audit_buf;
2756
2757        audit_buf = xfrm_audit_start("SPD-add");
2758        if (audit_buf == NULL)
2759                return;
2760        xfrm_audit_helper_usrinfo(auid, sessionid, secid, audit_buf);
2761        audit_log_format(audit_buf, " res=%u", result);
2762        xfrm_audit_common_policyinfo(xp, audit_buf);
2763        audit_log_end(audit_buf);
2764}
2765EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
2766
2767void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
2768                              kuid_t auid, u32 sessionid, u32 secid)
2769{
2770        struct audit_buffer *audit_buf;
2771
2772        audit_buf = xfrm_audit_start("SPD-delete");
2773        if (audit_buf == NULL)
2774                return;
2775        xfrm_audit_helper_usrinfo(auid, sessionid, secid, audit_buf);
2776        audit_log_format(audit_buf, " res=%u", result);
2777        xfrm_audit_common_policyinfo(xp, audit_buf);
2778        audit_log_end(audit_buf);
2779}
2780EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
2781#endif
2782
2783#ifdef CONFIG_XFRM_MIGRATE
2784static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
2785                                        const struct xfrm_selector *sel_tgt)
2786{
2787        if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
2788                if (sel_tgt->family == sel_cmp->family &&
2789                    xfrm_addr_cmp(&sel_tgt->daddr, &sel_cmp->daddr,
2790                                  sel_cmp->family) == 0 &&
2791                    xfrm_addr_cmp(&sel_tgt->saddr, &sel_cmp->saddr,
2792                                  sel_cmp->family) == 0 &&
2793                    sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
2794                    sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
2795                        return true;
2796                }
2797        } else {
2798                if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
2799                        return true;
2800                }
2801        }
2802        return false;
2803}
2804
2805static struct xfrm_policy * xfrm_migrate_policy_find(const struct xfrm_selector *sel,
2806                                                     u8 dir, u8 type)
2807{
2808        struct xfrm_policy *pol, *ret = NULL;
2809        struct hlist_node *entry;
2810        struct hlist_head *chain;
2811        u32 priority = ~0U;
2812
2813        read_lock_bh(&xfrm_policy_lock);
2814        chain = policy_hash_direct(&init_net, &sel->daddr, &sel->saddr, sel->family, dir);
2815        hlist_for_each_entry(pol, entry, chain, bydst) {
2816                if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2817                    pol->type == type) {
2818                        ret = pol;
2819                        priority = ret->priority;
2820                        break;
2821                }
2822        }
2823        chain = &init_net.xfrm.policy_inexact[dir];
2824        hlist_for_each_entry(pol, entry, chain, bydst) {
2825                if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2826                    pol->type == type &&
2827                    pol->priority < priority) {
2828                        ret = pol;
2829                        break;
2830                }
2831        }
2832
2833        if (ret)
2834                xfrm_pol_hold(ret);
2835
2836        read_unlock_bh(&xfrm_policy_lock);
2837
2838        return ret;
2839}
2840
2841static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
2842{
2843        int match = 0;
2844
2845        if (t->mode == m->mode && t->id.proto == m->proto &&
2846            (m->reqid == 0 || t->reqid == m->reqid)) {
2847                switch (t->mode) {
2848                case XFRM_MODE_TUNNEL:
2849                case XFRM_MODE_BEET:
2850                        if (xfrm_addr_cmp(&t->id.daddr, &m->old_daddr,
2851                                          m->old_family) == 0 &&
2852                            xfrm_addr_cmp(&t->saddr, &m->old_saddr,
2853                                          m->old_family) == 0) {
2854                                match = 1;
2855                        }
2856                        break;
2857                case XFRM_MODE_TRANSPORT:
2858                        /* in case of transport mode, template does not store
2859                           any IP addresses, hence we just compare mode and
2860                           protocol */
2861                        match = 1;
2862                        break;
2863                default:
2864                        break;
2865                }
2866        }
2867        return match;
2868}
2869
2870/* update endpoint address(es) of template(s) */
2871static int xfrm_policy_migrate(struct xfrm_policy *pol,
2872                               struct xfrm_migrate *m, int num_migrate)
2873{
2874        struct xfrm_migrate *mp;
2875        int i, j, n = 0;
2876
2877        write_lock_bh(&pol->lock);
2878        if (unlikely(pol->walk.dead)) {
2879                /* target policy has been deleted */
2880                write_unlock_bh(&pol->lock);
2881                return -ENOENT;
2882        }
2883
2884        for (i = 0; i < pol->xfrm_nr; i++) {
2885                for (j = 0, mp = m; j < num_migrate; j++, mp++) {
2886                        if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
2887                                continue;
2888                        n++;
2889                        if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
2890                            pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
2891                                continue;
2892                        /* update endpoints */
2893                        memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
2894                               sizeof(pol->xfrm_vec[i].id.daddr));
2895                        memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
2896                               sizeof(pol->xfrm_vec[i].saddr));
2897                        pol->xfrm_vec[i].encap_family = mp->new_family;
2898                        /* flush bundles */
2899                        atomic_inc(&pol->genid);
2900                }
2901        }
2902
2903        write_unlock_bh(&pol->lock);
2904
2905        if (!n)
2906                return -ENODATA;
2907
2908        return 0;
2909}
2910
2911static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
2912{
2913        int i, j;
2914
2915        if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
2916                return -EINVAL;
2917
2918        for (i = 0; i < num_migrate; i++) {
2919                if ((xfrm_addr_cmp(&m[i].old_daddr, &m[i].new_daddr,
2920                                   m[i].old_family) == 0) &&
2921                    (xfrm_addr_cmp(&m[i].old_saddr, &m[i].new_saddr,
2922                                   m[i].old_family) == 0))
2923                        return -EINVAL;
2924                if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
2925                    xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
2926                        return -EINVAL;
2927
2928                /* check if there is any duplicated entry */
2929                for (j = i + 1; j < num_migrate; j++) {
2930                        if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
2931                                    sizeof(m[i].old_daddr)) &&
2932                            !memcmp(&m[i].old_saddr, &m[j].old_saddr,
2933                                    sizeof(m[i].old_saddr)) &&
2934                            m[i].proto == m[j].proto &&
2935                            m[i].mode == m[j].mode &&
2936                            m[i].reqid == m[j].reqid &&
2937                            m[i].old_family == m[j].old_family)
2938                                return -EINVAL;
2939                }
2940        }
2941
2942        return 0;
2943}
2944
2945int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
2946                 struct xfrm_migrate *m, int num_migrate,
2947                 struct xfrm_kmaddress *k)
2948{
2949        int i, err, nx_cur = 0, nx_new = 0;
2950        struct xfrm_policy *pol = NULL;
2951        struct xfrm_state *x, *xc;
2952        struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
2953        struct xfrm_state *x_new[XFRM_MAX_DEPTH];
2954        struct xfrm_migrate *mp;
2955
2956        if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
2957                goto out;
2958
2959        /* Stage 1 - find policy */
2960        if ((pol = xfrm_migrate_policy_find(sel, dir, type)) == NULL) {
2961                err = -ENOENT;
2962                goto out;
2963        }
2964
2965        /* Stage 2 - find and update state(s) */
2966        for (i = 0, mp = m; i < num_migrate; i++, mp++) {
2967                if ((x = xfrm_migrate_state_find(mp))) {
2968                        x_cur[nx_cur] = x;
2969                        nx_cur++;
2970                        if ((xc = xfrm_state_migrate(x, mp))) {
2971                                x_new[nx_new] = xc;
2972                                nx_new++;
2973                        } else {
2974                                err = -ENODATA;
2975                                goto restore_state;
2976                        }
2977                }
2978        }
2979
2980        /* Stage 3 - update policy */
2981        if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
2982                goto restore_state;
2983
2984        /* Stage 4 - delete old state(s) */
2985        if (nx_cur) {
2986                xfrm_states_put(x_cur, nx_cur);
2987                xfrm_states_delete(x_cur, nx_cur);
2988        }
2989
2990        /* Stage 5 - announce */
2991        km_migrate(sel, dir, type, m, num_migrate, k);
2992
2993        xfrm_pol_put(pol);
2994
2995        return 0;
2996out:
2997        return err;
2998
2999restore_state:
3000        if (pol)
3001                xfrm_pol_put(pol);
3002        if (nx_cur)
3003                xfrm_states_put(x_cur, nx_cur);
3004        if (nx_new)
3005                xfrm_states_delete(x_new, nx_new);
3006
3007        return err;
3008}
3009EXPORT_SYMBOL(xfrm_migrate);
3010#endif
3011
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