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/xfrm.h>
  30#include <net/ip.h>
  31#ifdef CONFIG_XFRM_STATISTICS
  32#include <net/snmp.h>
  33#endif
  34
  35#include "xfrm_hash.h"
  36
  37DEFINE_MUTEX(xfrm_cfg_mutex);
  38EXPORT_SYMBOL(xfrm_cfg_mutex);
  39
  40static DEFINE_SPINLOCK(xfrm_policy_sk_bundle_lock);
  41static struct dst_entry *xfrm_policy_sk_bundles;
  42static DEFINE_RWLOCK(xfrm_policy_lock);
  43
  44static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
  45static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
  46
  47static struct kmem_cache *xfrm_dst_cache __read_mostly;
  48
  49static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
  50static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
  51static void xfrm_init_pmtu(struct dst_entry *dst);
  52static int stale_bundle(struct dst_entry *dst);
  53
  54static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
  55                                                int dir);
  56
  57static inline int
  58__xfrm4_selector_match(struct xfrm_selector *sel, struct flowi *fl)
  59{
  60        return  addr_match(&fl->fl4_dst, &sel->daddr, sel->prefixlen_d) &&
  61                addr_match(&fl->fl4_src, &sel->saddr, sel->prefixlen_s) &&
  62                !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
  63                !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
  64                (fl->proto == sel->proto || !sel->proto) &&
  65                (fl->oif == sel->ifindex || !sel->ifindex);
  66}
  67
  68static inline int
  69__xfrm6_selector_match(struct xfrm_selector *sel, struct flowi *fl)
  70{
  71        return  addr_match(&fl->fl6_dst, &sel->daddr, sel->prefixlen_d) &&
  72                addr_match(&fl->fl6_src, &sel->saddr, sel->prefixlen_s) &&
  73                !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
  74                !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
  75                (fl->proto == sel->proto || !sel->proto) &&
  76                (fl->oif == sel->ifindex || !sel->ifindex);
  77}
  78
  79int xfrm_selector_match(struct xfrm_selector *sel, struct flowi *fl,
  80                    unsigned short family)
  81{
  82        switch (family) {
  83        case AF_INET:
  84                return __xfrm4_selector_match(sel, fl);
  85        case AF_INET6:
  86                return __xfrm6_selector_match(sel, fl);
  87        }
  88        return 0;
  89}
  90
  91static inline struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos,
  92                                                  xfrm_address_t *saddr,
  93                                                  xfrm_address_t *daddr,
  94                                                  int family)
  95{
  96        struct xfrm_policy_afinfo *afinfo;
  97        struct dst_entry *dst;
  98
  99        afinfo = xfrm_policy_get_afinfo(family);
 100        if (unlikely(afinfo == NULL))
 101                return ERR_PTR(-EAFNOSUPPORT);
 102
 103        dst = afinfo->dst_lookup(net, tos, saddr, daddr);
 104
 105        xfrm_policy_put_afinfo(afinfo);
 106
 107        return dst;
 108}
 109
 110static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x, int tos,
 111                                                xfrm_address_t *prev_saddr,
 112                                                xfrm_address_t *prev_daddr,
 113                                                int family)
 114{
 115        struct net *net = xs_net(x);
 116        xfrm_address_t *saddr = &x->props.saddr;
 117        xfrm_address_t *daddr = &x->id.daddr;
 118        struct dst_entry *dst;
 119
 120        if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
 121                saddr = x->coaddr;
 122                daddr = prev_daddr;
 123        }
 124        if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
 125                saddr = prev_saddr;
 126                daddr = x->coaddr;
 127        }
 128
 129        dst = __xfrm_dst_lookup(net, tos, saddr, daddr, family);
 130
 131        if (!IS_ERR(dst)) {
 132                if (prev_saddr != saddr)
 133                        memcpy(prev_saddr, saddr,  sizeof(*prev_saddr));
 134                if (prev_daddr != daddr)
 135                        memcpy(prev_daddr, daddr,  sizeof(*prev_daddr));
 136        }
 137
 138        return dst;
 139}
 140
 141static inline unsigned long make_jiffies(long secs)
 142{
 143        if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
 144                return MAX_SCHEDULE_TIMEOUT-1;
 145        else
 146                return secs*HZ;
 147}
 148
 149static void xfrm_policy_timer(unsigned long data)
 150{
 151        struct xfrm_policy *xp = (struct xfrm_policy*)data;
 152        unsigned long now = get_seconds();
 153        long next = LONG_MAX;
 154        int warn = 0;
 155        int dir;
 156
 157        read_lock(&xp->lock);
 158
 159        if (unlikely(xp->walk.dead))
 160                goto out;
 161
 162        dir = xfrm_policy_id2dir(xp->index);
 163
 164        if (xp->lft.hard_add_expires_seconds) {
 165                long tmo = xp->lft.hard_add_expires_seconds +
 166                        xp->curlft.add_time - now;
 167                if (tmo <= 0)
 168                        goto expired;
 169                if (tmo < next)
 170                        next = tmo;
 171        }
 172        if (xp->lft.hard_use_expires_seconds) {
 173                long tmo = xp->lft.hard_use_expires_seconds +
 174                        (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 175                if (tmo <= 0)
 176                        goto expired;
 177                if (tmo < next)
 178                        next = tmo;
 179        }
 180        if (xp->lft.soft_add_expires_seconds) {
 181                long tmo = xp->lft.soft_add_expires_seconds +
 182                        xp->curlft.add_time - now;
 183                if (tmo <= 0) {
 184                        warn = 1;
 185                        tmo = XFRM_KM_TIMEOUT;
 186                }
 187                if (tmo < next)
 188                        next = tmo;
 189        }
 190        if (xp->lft.soft_use_expires_seconds) {
 191                long tmo = xp->lft.soft_use_expires_seconds +
 192                        (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 193                if (tmo <= 0) {
 194                        warn = 1;
 195                        tmo = XFRM_KM_TIMEOUT;
 196                }
 197                if (tmo < next)
 198                        next = tmo;
 199        }
 200
 201        if (warn)
 202                km_policy_expired(xp, dir, 0, 0);
 203        if (next != LONG_MAX &&
 204            !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
 205                xfrm_pol_hold(xp);
 206
 207out:
 208        read_unlock(&xp->lock);
 209        xfrm_pol_put(xp);
 210        return;
 211
 212expired:
 213        read_unlock(&xp->lock);
 214        if (!xfrm_policy_delete(xp, dir))
 215                km_policy_expired(xp, dir, 1, 0);
 216        xfrm_pol_put(xp);
 217}
 218
 219static struct flow_cache_object *xfrm_policy_flo_get(struct flow_cache_object *flo)
 220{
 221        struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
 222
 223        if (unlikely(pol->walk.dead))
 224                flo = NULL;
 225        else
 226                xfrm_pol_hold(pol);
 227
 228        return flo;
 229}
 230
 231static int xfrm_policy_flo_check(struct flow_cache_object *flo)
 232{
 233        struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
 234
 235        return !pol->walk.dead;
 236}
 237
 238static void xfrm_policy_flo_delete(struct flow_cache_object *flo)
 239{
 240        xfrm_pol_put(container_of(flo, struct xfrm_policy, flo));
 241}
 242
 243static const struct flow_cache_ops xfrm_policy_fc_ops = {
 244        .get = xfrm_policy_flo_get,
 245        .check = xfrm_policy_flo_check,
 246        .delete = xfrm_policy_flo_delete,
 247};
 248
 249/* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
 250 * SPD calls.
 251 */
 252
 253struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
 254{
 255        struct xfrm_policy *policy;
 256
 257        policy = kzalloc(sizeof(struct xfrm_policy), gfp);
 258
 259        if (policy) {
 260                write_pnet(&policy->xp_net, net);
 261                INIT_LIST_HEAD(&policy->walk.all);
 262                INIT_HLIST_NODE(&policy->bydst);
 263                INIT_HLIST_NODE(&policy->byidx);
 264                rwlock_init(&policy->lock);
 265                atomic_set(&policy->refcnt, 1);
 266                setup_timer(&policy->timer, xfrm_policy_timer,
 267                                (unsigned long)policy);
 268                policy->flo.ops = &xfrm_policy_fc_ops;
 269        }
 270        return policy;
 271}
 272EXPORT_SYMBOL(xfrm_policy_alloc);
 273
 274/* Destroy xfrm_policy: descendant resources must be released to this moment. */
 275
 276void xfrm_policy_destroy(struct xfrm_policy *policy)
 277{
 278        BUG_ON(!policy->walk.dead);
 279
 280        if (del_timer(&policy->timer))
 281                BUG();
 282
 283        security_xfrm_policy_free(policy->security);
 284        kfree(policy);
 285}
 286EXPORT_SYMBOL(xfrm_policy_destroy);
 287
 288/* Rule must be locked. Release descentant resources, announce
 289 * entry dead. The rule must be unlinked from lists to the moment.
 290 */
 291
 292static void xfrm_policy_kill(struct xfrm_policy *policy)
 293{
 294        policy->walk.dead = 1;
 295
 296        atomic_inc(&policy->genid);
 297
 298        if (del_timer(&policy->timer))
 299                xfrm_pol_put(policy);
 300
 301        xfrm_pol_put(policy);
 302}
 303
 304static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
 305
 306static inline unsigned int idx_hash(struct net *net, u32 index)
 307{
 308        return __idx_hash(index, net->xfrm.policy_idx_hmask);
 309}
 310
 311static struct hlist_head *policy_hash_bysel(struct net *net, struct xfrm_selector *sel, unsigned short family, int dir)
 312{
 313        unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 314        unsigned int hash = __sel_hash(sel, family, hmask);
 315
 316        return (hash == hmask + 1 ?
 317                &net->xfrm.policy_inexact[dir] :
 318                net->xfrm.policy_bydst[dir].table + hash);
 319}
 320
 321static struct hlist_head *policy_hash_direct(struct net *net, xfrm_address_t *daddr, xfrm_address_t *saddr, unsigned short family, int dir)
 322{
 323        unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 324        unsigned int hash = __addr_hash(daddr, saddr, family, hmask);
 325
 326        return net->xfrm.policy_bydst[dir].table + hash;
 327}
 328
 329static void xfrm_dst_hash_transfer(struct hlist_head *list,
 330                                   struct hlist_head *ndsttable,
 331                                   unsigned int nhashmask)
 332{
 333        struct hlist_node *entry, *tmp, *entry0 = NULL;
 334        struct xfrm_policy *pol;
 335        unsigned int h0 = 0;
 336
 337redo:
 338        hlist_for_each_entry_safe(pol, entry, tmp, list, bydst) {
 339                unsigned int h;
 340
 341                h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
 342                                pol->family, nhashmask);
 343                if (!entry0) {
 344                        hlist_del(entry);
 345                        hlist_add_head(&pol->bydst, ndsttable+h);
 346                        h0 = h;
 347                } else {
 348                        if (h != h0)
 349                                continue;
 350                        hlist_del(entry);
 351                        hlist_add_after(entry0, &pol->bydst);
 352                }
 353                entry0 = entry;
 354        }
 355        if (!hlist_empty(list)) {
 356                entry0 = NULL;
 357                goto redo;
 358        }
 359}
 360
 361static void xfrm_idx_hash_transfer(struct hlist_head *list,
 362                                   struct hlist_head *nidxtable,
 363                                   unsigned int nhashmask)
 364{
 365        struct hlist_node *entry, *tmp;
 366        struct xfrm_policy *pol;
 367
 368        hlist_for_each_entry_safe(pol, entry, tmp, list, byidx) {
 369                unsigned int h;
 370
 371                h = __idx_hash(pol->index, nhashmask);
 372                hlist_add_head(&pol->byidx, nidxtable+h);
 373        }
 374}
 375
 376static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
 377{
 378        return ((old_hmask + 1) << 1) - 1;
 379}
 380
 381static void xfrm_bydst_resize(struct net *net, int dir)
 382{
 383        unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 384        unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 385        unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 386        struct hlist_head *odst = net->xfrm.policy_bydst[dir].table;
 387        struct hlist_head *ndst = xfrm_hash_alloc(nsize);
 388        int i;
 389
 390        if (!ndst)
 391                return;
 392
 393        write_lock_bh(&xfrm_policy_lock);
 394
 395        for (i = hmask; i >= 0; i--)
 396                xfrm_dst_hash_transfer(odst + i, ndst, nhashmask);
 397
 398        net->xfrm.policy_bydst[dir].table = ndst;
 399        net->xfrm.policy_bydst[dir].hmask = nhashmask;
 400
 401        write_unlock_bh(&xfrm_policy_lock);
 402
 403        xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
 404}
 405
 406static void xfrm_byidx_resize(struct net *net, int total)
 407{
 408        unsigned int hmask = net->xfrm.policy_idx_hmask;
 409        unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 410        unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 411        struct hlist_head *oidx = net->xfrm.policy_byidx;
 412        struct hlist_head *nidx = xfrm_hash_alloc(nsize);
 413        int i;
 414
 415        if (!nidx)
 416                return;
 417
 418        write_lock_bh(&xfrm_policy_lock);
 419
 420        for (i = hmask; i >= 0; i--)
 421                xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
 422
 423        net->xfrm.policy_byidx = nidx;
 424        net->xfrm.policy_idx_hmask = nhashmask;
 425
 426        write_unlock_bh(&xfrm_policy_lock);
 427
 428        xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
 429}
 430
 431static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
 432{
 433        unsigned int cnt = net->xfrm.policy_count[dir];
 434        unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 435
 436        if (total)
 437                *total += cnt;
 438
 439        if ((hmask + 1) < xfrm_policy_hashmax &&
 440            cnt > hmask)
 441                return 1;
 442
 443        return 0;
 444}
 445
 446static inline int xfrm_byidx_should_resize(struct net *net, int total)
 447{
 448        unsigned int hmask = net->xfrm.policy_idx_hmask;
 449
 450        if ((hmask + 1) < xfrm_policy_hashmax &&
 451            total > hmask)
 452                return 1;
 453
 454        return 0;
 455}
 456
 457void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
 458{
 459        read_lock_bh(&xfrm_policy_lock);
 460        si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
 461        si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
 462        si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
 463        si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
 464        si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
 465        si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
 466        si->spdhcnt = net->xfrm.policy_idx_hmask;
 467        si->spdhmcnt = xfrm_policy_hashmax;
 468        read_unlock_bh(&xfrm_policy_lock);
 469}
 470EXPORT_SYMBOL(xfrm_spd_getinfo);
 471
 472static DEFINE_MUTEX(hash_resize_mutex);
 473static void xfrm_hash_resize(struct work_struct *work)
 474{
 475        struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
 476        int dir, total;
 477
 478        mutex_lock(&hash_resize_mutex);
 479
 480        total = 0;
 481        for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
 482                if (xfrm_bydst_should_resize(net, dir, &total))
 483                        xfrm_bydst_resize(net, dir);
 484        }
 485        if (xfrm_byidx_should_resize(net, total))
 486                xfrm_byidx_resize(net, total);
 487
 488        mutex_unlock(&hash_resize_mutex);
 489}
 490
 491/* Generate new index... KAME seems to generate them ordered by cost
 492 * of an absolute inpredictability of ordering of rules. This will not pass. */
 493static u32 xfrm_gen_index(struct net *net, int dir)
 494{
 495        static u32 idx_generator;
 496
 497        for (;;) {
 498                struct hlist_node *entry;
 499                struct hlist_head *list;
 500                struct xfrm_policy *p;
 501                u32 idx;
 502                int found;
 503
 504                idx = (idx_generator | dir);
 505                idx_generator += 8;
 506                if (idx == 0)
 507                        idx = 8;
 508                list = net->xfrm.policy_byidx + idx_hash(net, idx);
 509                found = 0;
 510                hlist_for_each_entry(p, entry, list, byidx) {
 511                        if (p->index == idx) {
 512                                found = 1;
 513                                break;
 514                        }
 515                }
 516                if (!found)
 517                        return idx;
 518        }
 519}
 520
 521static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
 522{
 523        u32 *p1 = (u32 *) s1;
 524        u32 *p2 = (u32 *) s2;
 525        int len = sizeof(struct xfrm_selector) / sizeof(u32);
 526        int i;
 527
 528        for (i = 0; i < len; i++) {
 529                if (p1[i] != p2[i])
 530                        return 1;
 531        }
 532
 533        return 0;
 534}
 535
 536int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 537{
 538        struct net *net = xp_net(policy);
 539        struct xfrm_policy *pol;
 540        struct xfrm_policy *delpol;
 541        struct hlist_head *chain;
 542        struct hlist_node *entry, *newpos;
 543        u32 mark = policy->mark.v & policy->mark.m;
 544
 545        write_lock_bh(&xfrm_policy_lock);
 546        chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
 547        delpol = NULL;
 548        newpos = NULL;
 549        hlist_for_each_entry(pol, entry, chain, bydst) {
 550                if (pol->type == policy->type &&
 551                    !selector_cmp(&pol->selector, &policy->selector) &&
 552                    (mark & pol->mark.m) == pol->mark.v &&
 553                    xfrm_sec_ctx_match(pol->security, policy->security) &&
 554                    !WARN_ON(delpol)) {
 555                        if (excl) {
 556                                write_unlock_bh(&xfrm_policy_lock);
 557                                return -EEXIST;
 558                        }
 559                        delpol = pol;
 560                        if (policy->priority > pol->priority)
 561                                continue;
 562                } else if (policy->priority >= pol->priority) {
 563                        newpos = &pol->bydst;
 564                        continue;
 565                }
 566                if (delpol)
 567                        break;
 568        }
 569        if (newpos)
 570                hlist_add_after(newpos, &policy->bydst);
 571        else
 572                hlist_add_head(&policy->bydst, chain);
 573        xfrm_pol_hold(policy);
 574        net->xfrm.policy_count[dir]++;
 575        atomic_inc(&flow_cache_genid);
 576        if (delpol)
 577                __xfrm_policy_unlink(delpol, dir);
 578        policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir);
 579        hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
 580        policy->curlft.add_time = get_seconds();
 581        policy->curlft.use_time = 0;
 582        if (!mod_timer(&policy->timer, jiffies + HZ))
 583                xfrm_pol_hold(policy);
 584        list_add(&policy->walk.all, &net->xfrm.policy_all);
 585        write_unlock_bh(&xfrm_policy_lock);
 586
 587        if (delpol)
 588                xfrm_policy_kill(delpol);
 589        else if (xfrm_bydst_should_resize(net, dir, NULL))
 590                schedule_work(&net->xfrm.policy_hash_work);
 591
 592        return 0;
 593}
 594EXPORT_SYMBOL(xfrm_policy_insert);
 595
 596struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type,
 597                                          int dir, struct xfrm_selector *sel,
 598                                          struct xfrm_sec_ctx *ctx, int delete,
 599                                          int *err)
 600{
 601        struct xfrm_policy *pol, *ret;
 602        struct hlist_head *chain;
 603        struct hlist_node *entry;
 604
 605        *err = 0;
 606        write_lock_bh(&xfrm_policy_lock);
 607        chain = policy_hash_bysel(net, sel, sel->family, dir);
 608        ret = NULL;
 609        hlist_for_each_entry(pol, entry, chain, bydst) {
 610                if (pol->type == type &&
 611                    (mark & pol->mark.m) == pol->mark.v &&
 612                    !selector_cmp(sel, &pol->selector) &&
 613                    xfrm_sec_ctx_match(ctx, pol->security)) {
 614                        xfrm_pol_hold(pol);
 615                        if (delete) {
 616                                *err = security_xfrm_policy_delete(
 617                                                                pol->security);
 618                                if (*err) {
 619                                        write_unlock_bh(&xfrm_policy_lock);
 620                                        return pol;
 621                                }
 622                                __xfrm_policy_unlink(pol, dir);
 623                        }
 624                        ret = pol;
 625                        break;
 626                }
 627        }
 628        write_unlock_bh(&xfrm_policy_lock);
 629
 630        if (ret && delete)
 631                xfrm_policy_kill(ret);
 632        return ret;
 633}
 634EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
 635
 636struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type,
 637                                     int dir, u32 id, int delete, int *err)
 638{
 639        struct xfrm_policy *pol, *ret;
 640        struct hlist_head *chain;
 641        struct hlist_node *entry;
 642
 643        *err = -ENOENT;
 644        if (xfrm_policy_id2dir(id) != dir)
 645                return NULL;
 646
 647        *err = 0;
 648        write_lock_bh(&xfrm_policy_lock);
 649        chain = net->xfrm.policy_byidx + idx_hash(net, id);
 650        ret = NULL;
 651        hlist_for_each_entry(pol, entry, chain, byidx) {
 652                if (pol->type == type && pol->index == id &&
 653                    (mark & pol->mark.m) == pol->mark.v) {
 654                        xfrm_pol_hold(pol);
 655                        if (delete) {
 656                                *err = security_xfrm_policy_delete(
 657                                                                pol->security);
 658                                if (*err) {
 659                                        write_unlock_bh(&xfrm_policy_lock);
 660                                        return pol;
 661                                }
 662                                __xfrm_policy_unlink(pol, dir);
 663                        }
 664                        ret = pol;
 665                        break;
 666                }
 667        }
 668        write_unlock_bh(&xfrm_policy_lock);
 669
 670        if (ret && delete)
 671                xfrm_policy_kill(ret);
 672        return ret;
 673}
 674EXPORT_SYMBOL(xfrm_policy_byid);
 675
 676#ifdef CONFIG_SECURITY_NETWORK_XFRM
 677static inline int
 678xfrm_policy_flush_secctx_check(struct net *net, u8 type, struct xfrm_audit *audit_info)
 679{
 680        int dir, err = 0;
 681
 682        for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 683                struct xfrm_policy *pol;
 684                struct hlist_node *entry;
 685                int i;
 686
 687                hlist_for_each_entry(pol, entry,
 688                                     &net->xfrm.policy_inexact[dir], bydst) {
 689                        if (pol->type != type)
 690                                continue;
 691                        err = security_xfrm_policy_delete(pol->security);
 692                        if (err) {
 693                                xfrm_audit_policy_delete(pol, 0,
 694                                                         audit_info->loginuid,
 695                                                         audit_info->sessionid,
 696                                                         audit_info->secid);
 697                                return err;
 698                        }
 699                }
 700                for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
 701                        hlist_for_each_entry(pol, entry,
 702                                             net->xfrm.policy_bydst[dir].table + i,
 703                                             bydst) {
 704                                if (pol->type != type)
 705                                        continue;
 706                                err = security_xfrm_policy_delete(
 707                                                                pol->security);
 708                                if (err) {
 709                                        xfrm_audit_policy_delete(pol, 0,
 710                                                        audit_info->loginuid,
 711                                                        audit_info->sessionid,
 712                                                        audit_info->secid);
 713                                        return err;
 714                                }
 715                        }
 716                }
 717        }
 718        return err;
 719}
 720#else
 721static inline int
 722xfrm_policy_flush_secctx_check(struct net *net, u8 type, struct xfrm_audit *audit_info)
 723{
 724        return 0;
 725}
 726#endif
 727
 728int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
 729{
 730        int dir, err = 0, cnt = 0;
 731
 732        write_lock_bh(&xfrm_policy_lock);
 733
 734        err = xfrm_policy_flush_secctx_check(net, type, audit_info);
 735        if (err)
 736                goto out;
 737
 738        for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 739                struct xfrm_policy *pol;
 740                struct hlist_node *entry;
 741                int i;
 742
 743        again1:
 744                hlist_for_each_entry(pol, entry,
 745                                     &net->xfrm.policy_inexact[dir], bydst) {
 746                        if (pol->type != type)
 747                                continue;
 748                        __xfrm_policy_unlink(pol, dir);
 749                        write_unlock_bh(&xfrm_policy_lock);
 750                        cnt++;
 751
 752                        xfrm_audit_policy_delete(pol, 1, audit_info->loginuid,
 753                                                 audit_info->sessionid,
 754                                                 audit_info->secid);
 755
 756                        xfrm_policy_kill(pol);
 757
 758                        write_lock_bh(&xfrm_policy_lock);
 759                        goto again1;
 760                }
 761
 762                for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
 763        again2:
 764                        hlist_for_each_entry(pol, entry,
 765                                             net->xfrm.policy_bydst[dir].table + i,
 766                                             bydst) {
 767                                if (pol->type != type)
 768                                        continue;
 769                                __xfrm_policy_unlink(pol, dir);
 770                                write_unlock_bh(&xfrm_policy_lock);
 771                                cnt++;
 772
 773                                xfrm_audit_policy_delete(pol, 1,
 774                                                         audit_info->loginuid,
 775                                                         audit_info->sessionid,
 776                                                         audit_info->secid);
 777                                xfrm_policy_kill(pol);
 778
 779                                write_lock_bh(&xfrm_policy_lock);
 780                                goto again2;
 781                        }
 782                }
 783
 784        }
 785        if (!cnt)
 786                err = -ESRCH;
 787out:
 788        write_unlock_bh(&xfrm_policy_lock);
 789        return err;
 790}
 791EXPORT_SYMBOL(xfrm_policy_flush);
 792
 793int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
 794                     int (*func)(struct xfrm_policy *, int, int, void*),
 795                     void *data)
 796{
 797        struct xfrm_policy *pol;
 798        struct xfrm_policy_walk_entry *x;
 799        int error = 0;
 800
 801        if (walk->type >= XFRM_POLICY_TYPE_MAX &&
 802            walk->type != XFRM_POLICY_TYPE_ANY)
 803                return -EINVAL;
 804
 805        if (list_empty(&walk->walk.all) && walk->seq != 0)
 806                return 0;
 807
 808        write_lock_bh(&xfrm_policy_lock);
 809        if (list_empty(&walk->walk.all))
 810                x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
 811        else
 812                x = list_entry(&walk->walk.all, struct xfrm_policy_walk_entry, all);
 813        list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
 814                if (x->dead)
 815                        continue;
 816                pol = container_of(x, struct xfrm_policy, walk);
 817                if (walk->type != XFRM_POLICY_TYPE_ANY &&
 818                    walk->type != pol->type)
 819                        continue;
 820                error = func(pol, xfrm_policy_id2dir(pol->index),
 821                             walk->seq, data);
 822                if (error) {
 823                        list_move_tail(&walk->walk.all, &x->all);
 824                        goto out;
 825                }
 826                walk->seq++;
 827        }
 828        if (walk->seq == 0) {
 829                error = -ENOENT;
 830                goto out;
 831        }
 832        list_del_init(&walk->walk.all);
 833out:
 834        write_unlock_bh(&xfrm_policy_lock);
 835        return error;
 836}
 837EXPORT_SYMBOL(xfrm_policy_walk);
 838
 839void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
 840{
 841        INIT_LIST_HEAD(&walk->walk.all);
 842        walk->walk.dead = 1;
 843        walk->type = type;
 844        walk->seq = 0;
 845}
 846EXPORT_SYMBOL(xfrm_policy_walk_init);
 847
 848void xfrm_policy_walk_done(struct xfrm_policy_walk *walk)
 849{
 850        if (list_empty(&walk->walk.all))
 851                return;
 852
 853        write_lock_bh(&xfrm_policy_lock);
 854        list_del(&walk->walk.all);
 855        write_unlock_bh(&xfrm_policy_lock);
 856}
 857EXPORT_SYMBOL(xfrm_policy_walk_done);
 858
 859/*
 860 * Find policy to apply to this flow.
 861 *
 862 * Returns 0 if policy found, else an -errno.
 863 */
 864static int xfrm_policy_match(struct xfrm_policy *pol, struct flowi *fl,
 865                             u8 type, u16 family, int dir)
 866{
 867        struct xfrm_selector *sel = &pol->selector;
 868        int match, ret = -ESRCH;
 869
 870        if (pol->family != family ||
 871            (fl->mark & pol->mark.m) != pol->mark.v ||
 872            pol->type != type)
 873                return ret;
 874
 875        match = xfrm_selector_match(sel, fl, family);
 876        if (match)
 877                ret = security_xfrm_policy_lookup(pol->security, fl->secid,
 878                                                  dir);
 879
 880        return ret;
 881}
 882
 883static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
 884                                                     struct flowi *fl,
 885                                                     u16 family, u8 dir)
 886{
 887        int err;
 888        struct xfrm_policy *pol, *ret;
 889        xfrm_address_t *daddr, *saddr;
 890        struct hlist_node *entry;
 891        struct hlist_head *chain;
 892        u32 priority = ~0U;
 893
 894        daddr = xfrm_flowi_daddr(fl, family);
 895        saddr = xfrm_flowi_saddr(fl, family);
 896        if (unlikely(!daddr || !saddr))
 897                return NULL;
 898
 899        read_lock_bh(&xfrm_policy_lock);
 900        chain = policy_hash_direct(net, daddr, saddr, family, dir);
 901        ret = NULL;
 902        hlist_for_each_entry(pol, entry, chain, bydst) {
 903                err = xfrm_policy_match(pol, fl, type, family, dir);
 904                if (err) {
 905                        if (err == -ESRCH)
 906                                continue;
 907                        else {
 908                                ret = ERR_PTR(err);
 909                                goto fail;
 910                        }
 911                } else {
 912                        ret = pol;
 913                        priority = ret->priority;
 914                        break;
 915                }
 916        }
 917        chain = &net->xfrm.policy_inexact[dir];
 918        hlist_for_each_entry(pol, entry, chain, bydst) {
 919                err = xfrm_policy_match(pol, fl, type, family, dir);
 920                if (err) {
 921                        if (err == -ESRCH)
 922                                continue;
 923                        else {
 924                                ret = ERR_PTR(err);
 925                                goto fail;
 926                        }
 927                } else if (pol->priority < priority) {
 928                        ret = pol;
 929                        break;
 930                }
 931        }
 932        if (ret)
 933                xfrm_pol_hold(ret);
 934fail:
 935        read_unlock_bh(&xfrm_policy_lock);
 936
 937        return ret;
 938}
 939
 940static struct xfrm_policy *
 941__xfrm_policy_lookup(struct net *net, struct flowi *fl, u16 family, u8 dir)
 942{
 943#ifdef CONFIG_XFRM_SUB_POLICY
 944        struct xfrm_policy *pol;
 945
 946        pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family, dir);
 947        if (pol != NULL)
 948                return pol;
 949#endif
 950        return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family, dir);
 951}
 952
 953static struct flow_cache_object *
 954xfrm_policy_lookup(struct net *net, struct flowi *fl, u16 family,
 955                   u8 dir, struct flow_cache_object *old_obj, void *ctx)
 956{
 957        struct xfrm_policy *pol;
 958
 959        if (old_obj)
 960                xfrm_pol_put(container_of(old_obj, struct xfrm_policy, flo));
 961
 962        pol = __xfrm_policy_lookup(net, fl, family, dir);
 963        if (IS_ERR_OR_NULL(pol))
 964                return ERR_CAST(pol);
 965
 966        /* Resolver returns two references:
 967         * one for cache and one for caller of flow_cache_lookup() */
 968        xfrm_pol_hold(pol);
 969
 970        return &pol->flo;
 971}
 972
 973static inline int policy_to_flow_dir(int dir)
 974{
 975        if (XFRM_POLICY_IN == FLOW_DIR_IN &&
 976            XFRM_POLICY_OUT == FLOW_DIR_OUT &&
 977            XFRM_POLICY_FWD == FLOW_DIR_FWD)
 978                return dir;
 979        switch (dir) {
 980        default:
 981        case XFRM_POLICY_IN:
 982                return FLOW_DIR_IN;
 983        case XFRM_POLICY_OUT:
 984                return FLOW_DIR_OUT;
 985        case XFRM_POLICY_FWD:
 986                return FLOW_DIR_FWD;
 987        }
 988}
 989
 990static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl)
 991{
 992        struct xfrm_policy *pol;
 993
 994        read_lock_bh(&xfrm_policy_lock);
 995        if ((pol = sk->sk_policy[dir]) != NULL) {
 996                int match = xfrm_selector_match(&pol->selector, fl,
 997                                                sk->sk_family);
 998                int err = 0;
 999
1000                if (match) {
1001                        if ((sk->sk_mark & pol->mark.m) != pol->mark.v) {
1002                                pol = NULL;
1003                                goto out;
1004                        }
1005                        err = security_xfrm_policy_lookup(pol->security,
1006                                                      fl->secid,
1007                                                      policy_to_flow_dir(dir));
1008                        if (!err)
1009                                xfrm_pol_hold(pol);
1010                        else if (err == -ESRCH)
1011                                pol = NULL;
1012                        else
1013                                pol = ERR_PTR(err);
1014                } else
1015                        pol = NULL;
1016        }
1017out:
1018        read_unlock_bh(&xfrm_policy_lock);
1019        return pol;
1020}
1021
1022static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
1023{
1024        struct net *net = xp_net(pol);
1025        struct hlist_head *chain = policy_hash_bysel(net, &pol->selector,
1026                                                     pol->family, dir);
1027
1028        list_add(&pol->walk.all, &net->xfrm.policy_all);
1029        hlist_add_head(&pol->bydst, chain);
1030        hlist_add_head(&pol->byidx, net->xfrm.policy_byidx+idx_hash(net, pol->index));
1031        net->xfrm.policy_count[dir]++;
1032        xfrm_pol_hold(pol);
1033
1034        if (xfrm_bydst_should_resize(net, dir, NULL))
1035                schedule_work(&net->xfrm.policy_hash_work);
1036}
1037
1038static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
1039                                                int dir)
1040{
1041        struct net *net = xp_net(pol);
1042
1043        if (hlist_unhashed(&pol->bydst))
1044                return NULL;
1045
1046        hlist_del(&pol->bydst);
1047        hlist_del(&pol->byidx);
1048        list_del(&pol->walk.all);
1049        net->xfrm.policy_count[dir]--;
1050
1051        return pol;
1052}
1053
1054int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
1055{
1056        write_lock_bh(&xfrm_policy_lock);
1057        pol = __xfrm_policy_unlink(pol, dir);
1058        write_unlock_bh(&xfrm_policy_lock);
1059        if (pol) {
1060                xfrm_policy_kill(pol);
1061                return 0;
1062        }
1063        return -ENOENT;
1064}
1065EXPORT_SYMBOL(xfrm_policy_delete);
1066
1067int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
1068{
1069        struct net *net = xp_net(pol);
1070        struct xfrm_policy *old_pol;
1071
1072#ifdef CONFIG_XFRM_SUB_POLICY
1073        if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
1074                return -EINVAL;
1075#endif
1076
1077        write_lock_bh(&xfrm_policy_lock);
1078        old_pol = sk->sk_policy[dir];
1079        sk->sk_policy[dir] = pol;
1080        if (pol) {
1081                pol->curlft.add_time = get_seconds();
1082                pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir);
1083                __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
1084        }
1085        if (old_pol)
1086                /* Unlinking succeeds always. This is the only function
1087                 * allowed to delete or replace socket policy.
1088                 */
1089                __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
1090        write_unlock_bh(&xfrm_policy_lock);
1091
1092        if (old_pol) {
1093                xfrm_policy_kill(old_pol);
1094        }
1095        return 0;
1096}
1097
1098static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir)
1099{
1100        struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
1101
1102        if (newp) {
1103                newp->selector = old->selector;
1104                if (security_xfrm_policy_clone(old->security,
1105                                               &newp->security)) {
1106                        kfree(newp);
1107                        return NULL;  /* ENOMEM */
1108                }
1109                newp->lft = old->lft;
1110                newp->curlft = old->curlft;
1111                newp->mark = old->mark;
1112                newp->action = old->action;
1113                newp->flags = old->flags;
1114                newp->xfrm_nr = old->xfrm_nr;
1115                newp->index = old->index;
1116                newp->type = old->type;
1117                memcpy(newp->xfrm_vec, old->xfrm_vec,
1118                       newp->xfrm_nr*sizeof(struct xfrm_tmpl));
1119                write_lock_bh(&xfrm_policy_lock);
1120                __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
1121                write_unlock_bh(&xfrm_policy_lock);
1122                xfrm_pol_put(newp);
1123        }
1124        return newp;
1125}
1126
1127int __xfrm_sk_clone_policy(struct sock *sk)
1128{
1129        struct xfrm_policy *p0 = sk->sk_policy[0],
1130                           *p1 = sk->sk_policy[1];
1131
1132        sk->sk_policy[0] = sk->sk_policy[1] = NULL;
1133        if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
1134                return -ENOMEM;
1135        if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
1136                return -ENOMEM;
1137        return 0;
1138}
1139
1140static int
1141xfrm_get_saddr(struct net *net, xfrm_address_t *local, xfrm_address_t *remote,
1142               unsigned short family)
1143{
1144        int err;
1145        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1146
1147        if (unlikely(afinfo == NULL))
1148                return -EINVAL;
1149        err = afinfo->get_saddr(net, local, remote);
1150        xfrm_policy_put_afinfo(afinfo);
1151        return err;
1152}
1153
1154/* Resolve list of templates for the flow, given policy. */
1155
1156static int
1157xfrm_tmpl_resolve_one(struct xfrm_policy *policy, struct flowi *fl,
1158                      struct xfrm_state **xfrm,
1159                      unsigned short family)
1160{
1161        struct net *net = xp_net(policy);
1162        int nx;
1163        int i, error;
1164        xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
1165        xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
1166        xfrm_address_t tmp;
1167
1168        for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
1169                struct xfrm_state *x;
1170                xfrm_address_t *remote = daddr;
1171                xfrm_address_t *local  = saddr;
1172                struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
1173
1174                if (tmpl->mode == XFRM_MODE_TUNNEL ||
1175                    tmpl->mode == XFRM_MODE_BEET) {
1176                        remote = &tmpl->id.daddr;
1177                        local = &tmpl->saddr;
1178                        family = tmpl->encap_family;
1179                        if (xfrm_addr_any(local, family)) {
1180                                error = xfrm_get_saddr(net, &tmp, remote, family);
1181                                if (error)
1182                                        goto fail;
1183                                local = &tmp;
1184                        }
1185                }
1186
1187                x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
1188
1189                if (x && x->km.state == XFRM_STATE_VALID) {
1190                        xfrm[nx++] = x;
1191                        daddr = remote;
1192                        saddr = local;
1193                        continue;
1194                }
1195                if (x) {
1196                        error = (x->km.state == XFRM_STATE_ERROR ?
1197                                 -EINVAL : -EAGAIN);
1198                        xfrm_state_put(x);
1199                }
1200                else if (error == -ESRCH)
1201                        error = -EAGAIN;
1202
1203                if (!tmpl->optional)
1204                        goto fail;
1205        }
1206        return nx;
1207
1208fail:
1209        for (nx--; nx>=0; nx--)
1210                xfrm_state_put(xfrm[nx]);
1211        return error;
1212}
1213
1214static int
1215xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, struct flowi *fl,
1216                  struct xfrm_state **xfrm,
1217                  unsigned short family)
1218{
1219        struct xfrm_state *tp[XFRM_MAX_DEPTH];
1220        struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
1221        int cnx = 0;
1222        int error;
1223        int ret;
1224        int i;
1225
1226        for (i = 0; i < npols; i++) {
1227                if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
1228                        error = -ENOBUFS;
1229                        goto fail;
1230                }
1231
1232                ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
1233                if (ret < 0) {
1234                        error = ret;
1235                        goto fail;
1236                } else
1237                        cnx += ret;
1238        }
1239
1240        /* found states are sorted for outbound processing */
1241        if (npols > 1)
1242                xfrm_state_sort(xfrm, tpp, cnx, family);
1243
1244        return cnx;
1245
1246 fail:
1247        for (cnx--; cnx>=0; cnx--)
1248                xfrm_state_put(tpp[cnx]);
1249        return error;
1250
1251}
1252
1253/* Check that the bundle accepts the flow and its components are
1254 * still valid.
1255 */
1256
1257static inline int xfrm_get_tos(struct flowi *fl, int family)
1258{
1259        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1260        int tos;
1261
1262        if (!afinfo)
1263                return -EINVAL;
1264
1265        tos = afinfo->get_tos(fl);
1266
1267        xfrm_policy_put_afinfo(afinfo);
1268
1269        return tos;
1270}
1271
1272static struct flow_cache_object *xfrm_bundle_flo_get(struct flow_cache_object *flo)
1273{
1274        struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1275        struct dst_entry *dst = &xdst->u.dst;
1276
1277        if (xdst->route == NULL) {
1278                /* Dummy bundle - if it has xfrms we were not
1279                 * able to build bundle as template resolution failed.
1280                 * It means we need to try again resolving. */
1281                if (xdst->num_xfrms > 0)
1282                        return NULL;
1283        } else {
1284                /* Real bundle */
1285                if (stale_bundle(dst))
1286                        return NULL;
1287        }
1288
1289        dst_hold(dst);
1290        return flo;
1291}
1292
1293static int xfrm_bundle_flo_check(struct flow_cache_object *flo)
1294{
1295        struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1296        struct dst_entry *dst = &xdst->u.dst;
1297
1298        if (!xdst->route)
1299                return 0;
1300        if (stale_bundle(dst))
1301                return 0;
1302
1303        return 1;
1304}
1305
1306static void xfrm_bundle_flo_delete(struct flow_cache_object *flo)
1307{
1308        struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1309        struct dst_entry *dst = &xdst->u.dst;
1310
1311        dst_free(dst);
1312}
1313
1314static const struct flow_cache_ops xfrm_bundle_fc_ops = {
1315        .get = xfrm_bundle_flo_get,
1316        .check = xfrm_bundle_flo_check,
1317        .delete = xfrm_bundle_flo_delete,
1318};
1319
1320static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
1321{
1322        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1323        struct dst_ops *dst_ops;
1324        struct xfrm_dst *xdst;
1325
1326        if (!afinfo)
1327                return ERR_PTR(-EINVAL);
1328
1329        switch (family) {
1330        case AF_INET:
1331                dst_ops = &net->xfrm.xfrm4_dst_ops;
1332                break;
1333#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1334        case AF_INET6:
1335                dst_ops = &net->xfrm.xfrm6_dst_ops;
1336                break;
1337#endif
1338        default:
1339                BUG();
1340        }
1341        xdst = dst_alloc(dst_ops) ?: ERR_PTR(-ENOBUFS);
1342        xfrm_policy_put_afinfo(afinfo);
1343
1344        xdst->flo.ops = &xfrm_bundle_fc_ops;
1345
1346        return xdst;
1347}
1348
1349static inline int xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
1350                                 int nfheader_len)
1351{
1352        struct xfrm_policy_afinfo *afinfo =
1353                xfrm_policy_get_afinfo(dst->ops->family);
1354        int err;
1355
1356        if (!afinfo)
1357                return -EINVAL;
1358
1359        err = afinfo->init_path(path, dst, nfheader_len);
1360
1361        xfrm_policy_put_afinfo(afinfo);
1362
1363        return err;
1364}
1365
1366static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
1367                                struct flowi *fl)
1368{
1369        struct xfrm_policy_afinfo *afinfo =
1370                xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
1371        int err;
1372
1373        if (!afinfo)
1374                return -EINVAL;
1375
1376        err = afinfo->fill_dst(xdst, dev, fl);
1377
1378        xfrm_policy_put_afinfo(afinfo);
1379
1380        return err;
1381}
1382
1383
1384/* Allocate chain of dst_entry's, attach known xfrm's, calculate
1385 * all the metrics... Shortly, bundle a bundle.
1386 */
1387
1388static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
1389                                            struct xfrm_state **xfrm, int nx,
1390                                            struct flowi *fl,
1391                                            struct dst_entry *dst)
1392{
1393        struct net *net = xp_net(policy);
1394        unsigned long now = jiffies;
1395        struct net_device *dev;
1396        struct dst_entry *dst_prev = NULL;
1397        struct dst_entry *dst0 = NULL;
1398        int i = 0;
1399        int err;
1400        int header_len = 0;
1401        int nfheader_len = 0;
1402        int trailer_len = 0;
1403        int tos;
1404        int family = policy->selector.family;
1405        xfrm_address_t saddr, daddr;
1406
1407        xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
1408
1409        tos = xfrm_get_tos(fl, family);
1410        err = tos;
1411        if (tos < 0)
1412                goto put_states;
1413
1414        dst_hold(dst);
1415
1416        for (; i < nx; i++) {
1417                struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
1418                struct dst_entry *dst1 = &xdst->u.dst;
1419
1420                err = PTR_ERR(xdst);
1421                if (IS_ERR(xdst)) {
1422                        dst_release(dst);
1423                        goto put_states;
1424                }
1425
1426                if (!dst_prev)
1427                        dst0 = dst1;
1428                else {
1429                        dst_prev->child = dst_clone(dst1);
1430                        dst1->flags |= DST_NOHASH;
1431                }
1432
1433                xdst->route = dst;
1434                memcpy(&dst1->metrics, &dst->metrics, sizeof(dst->metrics));
1435
1436                if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
1437                        family = xfrm[i]->props.family;
1438                        dst = xfrm_dst_lookup(xfrm[i], tos, &saddr, &daddr,
1439                                              family);
1440                        err = PTR_ERR(dst);
1441                        if (IS_ERR(dst))
1442                                goto put_states;
1443                } else
1444                        dst_hold(dst);
1445
1446                dst1->xfrm = xfrm[i];
1447                xdst->xfrm_genid = xfrm[i]->genid;
1448
1449                dst1->obsolete = -1;
1450                dst1->flags |= DST_HOST;
1451                dst1->lastuse = now;
1452
1453                dst1->input = dst_discard;
1454                dst1->output = xfrm[i]->outer_mode->afinfo->output;
1455
1456                dst1->next = dst_prev;
1457                dst_prev = dst1;
1458
1459                header_len += xfrm[i]->props.header_len;
1460                if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
1461                        nfheader_len += xfrm[i]->props.header_len;
1462                trailer_len += xfrm[i]->props.trailer_len;
1463        }
1464
1465        dst_prev->child = dst;
1466        dst0->path = dst;
1467
1468        err = -ENODEV;
1469        dev = dst->dev;
1470        if (!dev)
1471                goto free_dst;
1472
1473        /* Copy neighbour for reachability confirmation */
1474        dst0->neighbour = neigh_clone(dst->neighbour);
1475
1476        xfrm_init_path((struct xfrm_dst *)dst0, dst, nfheader_len);
1477        xfrm_init_pmtu(dst_prev);
1478
1479        for (dst_prev = dst0; dst_prev != dst; dst_prev = dst_prev->child) {
1480                struct xfrm_dst *xdst = (struct xfrm_dst *)dst_prev;
1481
1482                err = xfrm_fill_dst(xdst, dev, fl);
1483                if (err)
1484                        goto free_dst;
1485
1486                dst_prev->header_len = header_len;
1487                dst_prev->trailer_len = trailer_len;
1488                header_len -= xdst->u.dst.xfrm->props.header_len;
1489                trailer_len -= xdst->u.dst.xfrm->props.trailer_len;
1490        }
1491
1492out:
1493        return dst0;
1494
1495put_states:
1496        for (; i < nx; i++)
1497                xfrm_state_put(xfrm[i]);
1498free_dst:
1499        if (dst0)
1500                dst_free(dst0);
1501        dst0 = ERR_PTR(err);
1502        goto out;
1503}
1504
1505static int inline
1506xfrm_dst_alloc_copy(void **target, void *src, int size)
1507{
1508        if (!*target) {
1509                *target = kmalloc(size, GFP_ATOMIC);
1510                if (!*target)
1511                        return -ENOMEM;
1512        }
1513        memcpy(*target, src, size);
1514        return 0;
1515}
1516
1517static int inline
1518xfrm_dst_update_parent(struct dst_entry *dst, struct xfrm_selector *sel)
1519{
1520#ifdef CONFIG_XFRM_SUB_POLICY
1521        struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1522        return xfrm_dst_alloc_copy((void **)&(xdst->partner),
1523                                   sel, sizeof(*sel));
1524#else
1525        return 0;
1526#endif
1527}
1528
1529static int inline
1530xfrm_dst_update_origin(struct dst_entry *dst, struct flowi *fl)
1531{
1532#ifdef CONFIG_XFRM_SUB_POLICY
1533        struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1534        return xfrm_dst_alloc_copy((void **)&(xdst->origin), fl, sizeof(*fl));
1535#else
1536        return 0;
1537#endif
1538}
1539
1540static int xfrm_expand_policies(struct flowi *fl, u16 family,
1541                                struct xfrm_policy **pols,
1542                                int *num_pols, int *num_xfrms)
1543{
1544        int i;
1545
1546        if (*num_pols == 0 || !pols[0]) {
1547                *num_pols = 0;
1548                *num_xfrms = 0;
1549                return 0;
1550        }
1551        if (IS_ERR(pols[0]))
1552                return PTR_ERR(pols[0]);
1553
1554        *num_xfrms = pols[0]->xfrm_nr;
1555
1556#ifdef CONFIG_XFRM_SUB_POLICY
1557        if (pols[0] && pols[0]->action == XFRM_POLICY_ALLOW &&
1558            pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1559                pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
1560                                                    XFRM_POLICY_TYPE_MAIN,
1561                                                    fl, family,
1562                                                    XFRM_POLICY_OUT);
1563                if (pols[1]) {
1564                        if (IS_ERR(pols[1])) {
1565                                xfrm_pols_put(pols, *num_pols);
1566                                return PTR_ERR(pols[1]);
1567                        }
1568                        (*num_pols) ++;
1569                        (*num_xfrms) += pols[1]->xfrm_nr;
1570                }
1571        }
1572#endif
1573        for (i = 0; i < *num_pols; i++) {
1574                if (pols[i]->action != XFRM_POLICY_ALLOW) {
1575                        *num_xfrms = -1;
1576                        break;
1577                }
1578        }
1579
1580        return 0;
1581
1582}
1583
1584static struct xfrm_dst *
1585xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
1586                               struct flowi *fl, u16 family,
1587                               struct dst_entry *dst_orig)
1588{
1589        struct net *net = xp_net(pols[0]);
1590        struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
1591        struct dst_entry *dst;
1592        struct xfrm_dst *xdst;
1593        int err;
1594
1595        /* Try to instantiate a bundle */
1596        err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
1597        if (err <= 0) {
1598                if (err != 0 && err != -EAGAIN)
1599                        XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
1600                return ERR_PTR(err);
1601        }
1602
1603        dst = xfrm_bundle_create(pols[0], xfrm, err, fl, dst_orig);
1604        if (IS_ERR(dst)) {
1605                XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
1606                return ERR_CAST(dst);
1607        }
1608
1609        xdst = (struct xfrm_dst *)dst;
1610        xdst->num_xfrms = err;
1611        if (num_pols > 1)
1612                err = xfrm_dst_update_parent(dst, &pols[1]->selector);
1613        else
1614                err = xfrm_dst_update_origin(dst, fl);
1615        if (unlikely(err)) {
1616                dst_free(dst);
1617                XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLECHECKERROR);
1618                return ERR_PTR(err);
1619        }
1620
1621        xdst->num_pols = num_pols;
1622        memcpy(xdst->pols, pols, sizeof(struct xfrm_policy*) * num_pols);
1623        xdst->policy_genid = atomic_read(&pols[0]->genid);
1624
1625        return xdst;
1626}
1627
1628static struct flow_cache_object *
1629xfrm_bundle_lookup(struct net *net, struct flowi *fl, u16 family, u8 dir,
1630                   struct flow_cache_object *oldflo, void *ctx)
1631{
1632        struct dst_entry *dst_orig = (struct dst_entry *)ctx;
1633        struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1634        struct xfrm_dst *xdst, *new_xdst;
1635        int num_pols = 0, num_xfrms = 0, i, err, pol_dead;
1636
1637        /* Check if the policies from old bundle are usable */
1638        xdst = NULL;
1639        if (oldflo) {
1640                xdst = container_of(oldflo, struct xfrm_dst, flo);
1641                num_pols = xdst->num_pols;
1642                num_xfrms = xdst->num_xfrms;
1643                pol_dead = 0;
1644                for (i = 0; i < num_pols; i++) {
1645                        pols[i] = xdst->pols[i];
1646                        pol_dead |= pols[i]->walk.dead;
1647                }
1648                if (pol_dead) {
1649                        dst_free(&xdst->u.dst);
1650                        xdst = NULL;
1651                        num_pols = 0;
1652                        num_xfrms = 0;
1653                        oldflo = NULL;
1654                }
1655        }
1656
1657        /* Resolve policies to use if we couldn't get them from
1658         * previous cache entry */
1659        if (xdst == NULL) {
1660                num_pols = 1;
1661                pols[0] = __xfrm_policy_lookup(net, fl, family, dir);
1662                err = xfrm_expand_policies(fl, family, pols,
1663                                           &num_pols, &num_xfrms);
1664                if (err < 0)
1665                        goto inc_error;
1666                if (num_pols == 0)
1667                        return NULL;
1668                if (num_xfrms <= 0)
1669                        goto make_dummy_bundle;
1670        }
1671
1672        new_xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family, dst_orig);
1673        if (IS_ERR(new_xdst)) {
1674                err = PTR_ERR(new_xdst);
1675                if (err != -EAGAIN)
1676                        goto error;
1677                if (oldflo == NULL)
1678                        goto make_dummy_bundle;
1679                dst_hold(&xdst->u.dst);
1680                return oldflo;
1681        } else if (new_xdst == NULL) {
1682                num_xfrms = 0;
1683                if (oldflo == NULL)
1684                        goto make_dummy_bundle;
1685                xdst->num_xfrms = 0;
1686                dst_hold(&xdst->u.dst);
1687                return oldflo;
1688        }
1689
1690        /* Kill the previous bundle */
1691        if (xdst) {
1692                /* The policies were stolen for newly generated bundle */
1693                xdst->num_pols = 0;
1694                dst_free(&xdst->u.dst);
1695        }
1696
1697        /* Flow cache does not have reference, it dst_free()'s,
1698         * but we do need to return one reference for original caller */
1699        dst_hold(&new_xdst->u.dst);
1700        return &new_xdst->flo;
1701
1702make_dummy_bundle:
1703        /* We found policies, but there's no bundles to instantiate:
1704         * either because the policy blocks, has no transformations or
1705         * we could not build template (no xfrm_states).*/
1706        xdst = xfrm_alloc_dst(net, family);
1707        if (IS_ERR(xdst)) {
1708                xfrm_pols_put(pols, num_pols);
1709                return ERR_CAST(xdst);
1710        }
1711        xdst->num_pols = num_pols;
1712        xdst->num_xfrms = num_xfrms;
1713        memcpy(xdst->pols, pols, sizeof(struct xfrm_policy*) * num_pols);
1714
1715        dst_hold(&xdst->u.dst);
1716        return &xdst->flo;
1717
1718inc_error:
1719        XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
1720error:
1721        if (xdst != NULL)
1722                dst_free(&xdst->u.dst);
1723        else
1724                xfrm_pols_put(pols, num_pols);
1725        return ERR_PTR(err);
1726}
1727
1728/* Main function: finds/creates a bundle for given flow.
1729 *
1730 * At the moment we eat a raw IP route. Mostly to speed up lookups
1731 * on interfaces with disabled IPsec.
1732 */
1733int __xfrm_lookup(struct net *net, struct dst_entry **dst_p, struct flowi *fl,
1734                  struct sock *sk, int flags)
1735{
1736        struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1737        struct flow_cache_object *flo;
1738        struct xfrm_dst *xdst;
1739        struct dst_entry *dst, *dst_orig = *dst_p, *route;
1740        u16 family = dst_orig->ops->family;
1741        u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
1742        int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
1743
1744restart:
1745        dst = NULL;
1746        xdst = NULL;
1747        route = NULL;
1748
1749        if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
1750                num_pols = 1;
1751                pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
1752                err = xfrm_expand_policies(fl, family, pols,
1753                                           &num_pols, &num_xfrms);
1754                if (err < 0)
1755                        goto dropdst;
1756
1757                if (num_pols) {
1758                        if (num_xfrms <= 0) {
1759                                drop_pols = num_pols;
1760                                goto no_transform;
1761                        }
1762
1763                        xdst = xfrm_resolve_and_create_bundle(
1764                                        pols, num_pols, fl,
1765                                        family, dst_orig);
1766                        if (IS_ERR(xdst)) {
1767                                xfrm_pols_put(pols, num_pols);
1768                                err = PTR_ERR(xdst);
1769                                goto dropdst;
1770                        } else if (xdst == NULL) {
1771                                num_xfrms = 0;
1772                                drop_pols = num_pols;
1773                                goto no_transform;
1774                        }
1775
1776                        spin_lock_bh(&xfrm_policy_sk_bundle_lock);
1777                        xdst->u.dst.next = xfrm_policy_sk_bundles;
1778                        xfrm_policy_sk_bundles = &xdst->u.dst;
1779                        spin_unlock_bh(&xfrm_policy_sk_bundle_lock);
1780
1781                        route = xdst->route;
1782                }
1783        }
1784
1785        if (xdst == NULL) {
1786                /* To accelerate a bit...  */
1787                if ((dst_orig->flags & DST_NOXFRM) ||
1788                    !net->xfrm.policy_count[XFRM_POLICY_OUT])
1789                        goto nopol;
1790
1791                flo = flow_cache_lookup(net, fl, family, dir,
1792                                        xfrm_bundle_lookup, dst_orig);
1793                if (flo == NULL)
1794                        goto nopol;
1795                if (IS_ERR(flo)) {
1796                        err = PTR_ERR(flo);
1797                        goto dropdst;
1798                }
1799                xdst = container_of(flo, struct xfrm_dst, flo);
1800
1801                num_pols = xdst->num_pols;
1802                num_xfrms = xdst->num_xfrms;
1803                memcpy(pols, xdst->pols, sizeof(struct xfrm_policy*) * num_pols);
1804                route = xdst->route;
1805        }
1806
1807        dst = &xdst->u.dst;
1808        if (route == NULL && num_xfrms > 0) {
1809                /* The only case when xfrm_bundle_lookup() returns a
1810                 * bundle with null route, is when the template could
1811                 * not be resolved. It means policies are there, but
1812                 * bundle could not be created, since we don't yet
1813                 * have the xfrm_state's. We need to wait for KM to
1814                 * negotiate new SA's or bail out with error.*/
1815                if (net->xfrm.sysctl_larval_drop) {
1816                        /* EREMOTE tells the caller to generate
1817                         * a one-shot blackhole route. */
1818                        dst_release(dst);
1819                        xfrm_pols_put(pols, drop_pols);
1820                        XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
1821                        return -EREMOTE;
1822                }
1823                if (flags & XFRM_LOOKUP_WAIT) {
1824                        DECLARE_WAITQUEUE(wait, current);
1825
1826                        add_wait_queue(&net->xfrm.km_waitq, &wait);
1827                        set_current_state(TASK_INTERRUPTIBLE);
1828                        schedule();
1829                        set_current_state(TASK_RUNNING);
1830                        remove_wait_queue(&net->xfrm.km_waitq, &wait);
1831
1832                        if (!signal_pending(current)) {
1833                                dst_release(dst);
1834                                goto restart;
1835                        }
1836
1837                        err = -ERESTART;
1838                } else
1839                        err = -EAGAIN;
1840
1841                XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
1842                goto error;
1843        }
1844
1845no_transform:
1846        if (num_pols == 0)
1847                goto nopol;
1848
1849        if ((flags & XFRM_LOOKUP_ICMP) &&
1850            !(pols[0]->flags & XFRM_POLICY_ICMP)) {
1851                err = -ENOENT;
1852                goto error;
1853        }
1854
1855        for (i = 0; i < num_pols; i++)
1856                pols[i]->curlft.use_time = get_seconds();
1857
1858        if (num_xfrms < 0) {
1859                /* Prohibit the flow */
1860                XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
1861                err = -EPERM;
1862                goto error;
1863        } else if (num_xfrms > 0) {
1864                /* Flow transformed */
1865                *dst_p = dst;
1866                dst_release(dst_orig);
1867        } else {
1868                /* Flow passes untransformed */
1869                dst_release(dst);
1870        }
1871ok:
1872        xfrm_pols_put(pols, drop_pols);
1873        return 0;
1874
1875nopol:
1876        if (!(flags & XFRM_LOOKUP_ICMP))
1877                goto ok;
1878        err = -ENOENT;
1879error:
1880        dst_release(dst);
1881dropdst:
1882        dst_release(dst_orig);
1883        *dst_p = NULL;
1884        xfrm_pols_put(pols, drop_pols);
1885        return err;
1886}
1887EXPORT_SYMBOL(__xfrm_lookup);
1888
1889int xfrm_lookup(struct net *net, struct dst_entry **dst_p, struct flowi *fl,
1890                struct sock *sk, int flags)
1891{
1892        int err = __xfrm_lookup(net, dst_p, fl, sk, flags);
1893
1894        if (err == -EREMOTE) {
1895                dst_release(*dst_p);
1896                *dst_p = NULL;
1897                err = -EAGAIN;
1898        }
1899
1900        return err;
1901}
1902EXPORT_SYMBOL(xfrm_lookup);
1903
1904static inline int
1905xfrm_secpath_reject(int idx, struct sk_buff *skb, struct flowi *fl)
1906{
1907        struct xfrm_state *x;
1908
1909        if (!skb->sp || idx < 0 || idx >= skb->sp->len)
1910                return 0;
1911        x = skb->sp->xvec[idx];
1912        if (!x->type->reject)
1913                return 0;
1914        return x->type->reject(x, skb, fl);
1915}
1916
1917/* When skb is transformed back to its "native" form, we have to
1918 * check policy restrictions. At the moment we make this in maximally
1919 * stupid way. Shame on me. :-) Of course, connected sockets must
1920 * have policy cached at them.
1921 */
1922
1923static inline int
1924xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x,
1925              unsigned short family)
1926{
1927        if (xfrm_state_kern(x))
1928                return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
1929        return  x->id.proto == tmpl->id.proto &&
1930                (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
1931                (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
1932                x->props.mode == tmpl->mode &&
1933                (tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
1934                 !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
1935                !(x->props.mode != XFRM_MODE_TRANSPORT &&
1936                  xfrm_state_addr_cmp(tmpl, x, family));
1937}
1938
1939/*
1940 * 0 or more than 0 is returned when validation is succeeded (either bypass
1941 * because of optional transport mode, or next index of the mathced secpath
1942 * state with the template.
1943 * -1 is returned when no matching template is found.
1944 * Otherwise "-2 - errored_index" is returned.
1945 */
1946static inline int
1947xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
1948               unsigned short family)
1949{
1950        int idx = start;
1951
1952        if (tmpl->optional) {
1953                if (tmpl->mode == XFRM_MODE_TRANSPORT)
1954                        return start;
1955        } else
1956                start = -1;
1957        for (; idx < sp->len; idx++) {
1958                if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
1959                        return ++idx;
1960                if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
1961                        if (start == -1)
1962                                start = -2-idx;
1963                        break;
1964                }
1965        }
1966        return start;
1967}
1968
1969int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
1970                          unsigned int family, int reverse)
1971{
1972        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1973        int err;
1974
1975        if (unlikely(afinfo == NULL))
1976                return -EAFNOSUPPORT;
1977
1978        afinfo->decode_session(skb, fl, reverse);
1979        err = security_xfrm_decode_session(skb, &fl->secid);
1980        xfrm_policy_put_afinfo(afinfo);
1981        return err;
1982}
1983EXPORT_SYMBOL(__xfrm_decode_session);
1984
1985static inline int secpath_has_nontransport(struct sec_path *sp, int k, int *idxp)
1986{
1987        for (; k < sp->len; k++) {
1988                if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
1989                        *idxp = k;
1990                        return 1;
1991                }
1992        }
1993
1994        return 0;
1995}
1996
1997int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
1998                        unsigned short family)
1999{
2000        struct net *net = dev_net(skb->dev);
2001        struct xfrm_policy *pol;
2002        struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2003        int npols = 0;
2004        int xfrm_nr;
2005        int pi;
2006        int reverse;
2007        struct flowi fl;
2008        u8 fl_dir;
2009        int xerr_idx = -1;
2010
2011        reverse = dir & ~XFRM_POLICY_MASK;
2012        dir &= XFRM_POLICY_MASK;
2013        fl_dir = policy_to_flow_dir(dir);
2014
2015        if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) {
2016                XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
2017                return 0;
2018        }
2019
2020        nf_nat_decode_session(skb, &fl, family);
2021
2022        /* First, check used SA against their selectors. */
2023        if (skb->sp) {
2024                int i;
2025
2026                for (i=skb->sp->len-1; i>=0; i--) {
2027                        struct xfrm_state *x = skb->sp->xvec[i];
2028                        if (!xfrm_selector_match(&x->sel, &fl, family)) {
2029                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
2030                                return 0;
2031                        }
2032                }
2033        }
2034
2035        pol = NULL;
2036        if (sk && sk->sk_policy[dir]) {
2037                pol = xfrm_sk_policy_lookup(sk, dir, &fl);
2038                if (IS_ERR(pol)) {
2039                        XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2040                        return 0;
2041                }
2042        }
2043
2044        if (!pol) {
2045                struct flow_cache_object *flo;
2046
2047                flo = flow_cache_lookup(net, &fl, family, fl_dir,
2048                                        xfrm_policy_lookup, NULL);
2049                if (IS_ERR_OR_NULL(flo))
2050                        pol = ERR_CAST(flo);
2051                else
2052                        pol = container_of(flo, struct xfrm_policy, flo);
2053        }
2054
2055        if (IS_ERR(pol)) {
2056                XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2057                return 0;
2058        }
2059
2060        if (!pol) {
2061                if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
2062                        xfrm_secpath_reject(xerr_idx, skb, &fl);
2063                        XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
2064                        return 0;
2065                }
2066                return 1;
2067        }
2068
2069        pol->curlft.use_time = get_seconds();
2070
2071        pols[0] = pol;
2072        npols ++;
2073#ifdef CONFIG_XFRM_SUB_POLICY
2074        if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2075                pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
2076                                                    &fl, family,
2077                                                    XFRM_POLICY_IN);
2078                if (pols[1]) {
2079                        if (IS_ERR(pols[1])) {
2080                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2081                                return 0;
2082                        }
2083                        pols[1]->curlft.use_time = get_seconds();
2084                        npols ++;
2085                }
2086        }
2087#endif
2088
2089        if (pol->action == XFRM_POLICY_ALLOW) {
2090                struct sec_path *sp;
2091                static struct sec_path dummy;
2092                struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
2093                struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
2094                struct xfrm_tmpl **tpp = tp;
2095                int ti = 0;
2096                int i, k;
2097
2098                if ((sp = skb->sp) == NULL)
2099                        sp = &dummy;
2100
2101                for (pi = 0; pi < npols; pi++) {
2102                        if (pols[pi] != pol &&
2103                            pols[pi]->action != XFRM_POLICY_ALLOW) {
2104                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2105                                goto reject;
2106                        }
2107                        if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
2108                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
2109                                goto reject_error;
2110                        }
2111                        for (i = 0; i < pols[pi]->xfrm_nr; i++)
2112                                tpp[ti++] = &pols[pi]->xfrm_vec[i];
2113                }
2114                xfrm_nr = ti;
2115                if (npols > 1) {
2116                        xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
2117                        tpp = stp;
2118                }
2119
2120                /* For each tunnel xfrm, find the first matching tmpl.
2121                 * For each tmpl before that, find corresponding xfrm.
2122                 * Order is _important_. Later we will implement
2123                 * some barriers, but at the moment barriers
2124                 * are implied between each two transformations.
2125                 */
2126                for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
2127                        k = xfrm_policy_ok(tpp[i], sp, k, family);
2128                        if (k < 0) {
2129                                if (k < -1)
2130                                        /* "-2 - errored_index" returned */
2131                                        xerr_idx = -(2+k);
2132                                XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2133                                goto reject;
2134                        }
2135                }
2136
2137                if (secpath_has_nontransport(sp, k, &xerr_idx)) {
2138                        XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2139                        goto reject;
2140                }
2141
2142                xfrm_pols_put(pols, npols);
2143                return 1;
2144        }
2145        XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2146
2147reject:
2148        xfrm_secpath_reject(xerr_idx, skb, &fl);
2149reject_error:
2150        xfrm_pols_put(pols, npols);
2151        return 0;
2152}
2153EXPORT_SYMBOL(__xfrm_policy_check);
2154
2155int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
2156{
2157        struct net *net = dev_net(skb->dev);
2158        struct flowi fl;
2159        struct dst_entry *dst;
2160        int res;
2161
2162        if (xfrm_decode_session(skb, &fl, family) < 0) {
2163                XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
2164                return 0;
2165        }
2166
2167        skb_dst_force(skb);
2168        dst = skb_dst(skb);
2169
2170        res = xfrm_lookup(net, &dst, &fl, NULL, 0) == 0;
2171        skb_dst_set(skb, dst);
2172        return res;
2173}
2174EXPORT_SYMBOL(__xfrm_route_forward);
2175
2176/* Optimize later using cookies and generation ids. */
2177
2178static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
2179{
2180        /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
2181         * to "-1" to force all XFRM destinations to get validated by
2182         * dst_ops->check on every use.  We do this because when a
2183         * normal route referenced by an XFRM dst is obsoleted we do
2184         * not go looking around for all parent referencing XFRM dsts
2185         * so that we can invalidate them.  It is just too much work.
2186         * Instead we make the checks here on every use.  For example:
2187         *
2188         *      XFRM dst A --> IPv4 dst X
2189         *
2190         * X is the "xdst->route" of A (X is also the "dst->path" of A
2191         * in this example).  If X is marked obsolete, "A" will not
2192         * notice.  That's what we are validating here via the
2193         * stale_bundle() check.
2194         *
2195         * When a policy's bundle is pruned, we dst_free() the XFRM
2196         * dst which causes it's ->obsolete field to be set to a
2197         * positive non-zero integer.  If an XFRM dst has been pruned
2198         * like this, we want to force a new route lookup.
2199         */
2200        if (dst->obsolete < 0 && !stale_bundle(dst))
2201                return dst;
2202
2203        return NULL;
2204}
2205
2206static int stale_bundle(struct dst_entry *dst)
2207{
2208        return !xfrm_bundle_ok(NULL, (struct xfrm_dst *)dst, NULL, AF_UNSPEC, 0);
2209}
2210
2211void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
2212{
2213        while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
2214                dst->dev = dev_net(dev)->loopback_dev;
2215                dev_hold(dst->dev);
2216                dev_put(dev);
2217        }
2218}
2219EXPORT_SYMBOL(xfrm_dst_ifdown);
2220
2221static void xfrm_link_failure(struct sk_buff *skb)
2222{
2223        /* Impossible. Such dst must be popped before reaches point of failure. */
2224}
2225
2226static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
2227{
2228        if (dst) {
2229                if (dst->obsolete) {
2230                        dst_release(dst);
2231                        dst = NULL;
2232                }
2233        }
2234        return dst;
2235}
2236
2237static void __xfrm_garbage_collect(struct net *net)
2238{
2239        struct dst_entry *head, *next;
2240
2241        flow_cache_flush();
2242
2243        spin_lock_bh(&xfrm_policy_sk_bundle_lock);
2244        head = xfrm_policy_sk_bundles;
2245        xfrm_policy_sk_bundles = NULL;
2246        spin_unlock_bh(&xfrm_policy_sk_bundle_lock);
2247
2248        while (head) {
2249                next = head->next;
2250                dst_free(head);
2251                head = next;
2252        }
2253}
2254
2255static void xfrm_init_pmtu(struct dst_entry *dst)
2256{
2257        do {
2258                struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2259                u32 pmtu, route_mtu_cached;
2260
2261                pmtu = dst_mtu(dst->child);
2262                xdst->child_mtu_cached = pmtu;
2263
2264                pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
2265
2266                route_mtu_cached = dst_mtu(xdst->route);
2267                xdst->route_mtu_cached = route_mtu_cached;
2268
2269                if (pmtu > route_mtu_cached)
2270                        pmtu = route_mtu_cached;
2271
2272                dst->metrics[RTAX_MTU-1] = pmtu;
2273        } while ((dst = dst->next));
2274}
2275
2276/* Check that the bundle accepts the flow and its components are
2277 * still valid.
2278 */
2279
2280int xfrm_bundle_ok(struct xfrm_policy *pol, struct xfrm_dst *first,
2281                struct flowi *fl, int family, int strict)
2282{
2283        struct dst_entry *dst = &first->u.dst;
2284        struct xfrm_dst *last;
2285        u32 mtu;
2286
2287        if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
2288            (dst->dev && !netif_running(dst->dev)))
2289                return 0;
2290#ifdef CONFIG_XFRM_SUB_POLICY
2291        if (fl) {
2292                if (first->origin && !flow_cache_uli_match(first->origin, fl))
2293                        return 0;
2294                if (first->partner &&
2295                    !xfrm_selector_match(first->partner, fl, family))
2296                        return 0;
2297        }
2298#endif
2299
2300        last = NULL;
2301
2302        do {
2303                struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2304
2305                if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
2306                        return 0;
2307                if (fl && pol &&
2308                    !security_xfrm_state_pol_flow_match(dst->xfrm, pol, fl))
2309                        return 0;
2310                if (dst->xfrm->km.state != XFRM_STATE_VALID)
2311                        return 0;
2312                if (xdst->xfrm_genid != dst->xfrm->genid)
2313                        return 0;
2314                if (xdst->num_pols > 0 &&
2315                    xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
2316                        return 0;
2317
2318                if (strict && fl &&
2319                    !(dst->xfrm->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) &&
2320                    !xfrm_state_addr_flow_check(dst->xfrm, fl, family))
2321                        return 0;
2322
2323                mtu = dst_mtu(dst->child);
2324                if (xdst->child_mtu_cached != mtu) {
2325                        last = xdst;
2326                        xdst->child_mtu_cached = mtu;
2327                }
2328
2329                if (!dst_check(xdst->route, xdst->route_cookie))
2330                        return 0;
2331                mtu = dst_mtu(xdst->route);
2332                if (xdst->route_mtu_cached != mtu) {
2333                        last = xdst;
2334                        xdst->route_mtu_cached = mtu;
2335                }
2336
2337                dst = dst->child;
2338        } while (dst->xfrm);
2339
2340        if (likely(!last))
2341                return 1;
2342
2343        mtu = last->child_mtu_cached;
2344        for (;;) {
2345                dst = &last->u.dst;
2346
2347                mtu = xfrm_state_mtu(dst->xfrm, mtu);
2348                if (mtu > last->route_mtu_cached)
2349                        mtu = last->route_mtu_cached;
2350                dst->metrics[RTAX_MTU-1] = mtu;
2351
2352                if (last == first)
2353                        break;
2354
2355                last = (struct xfrm_dst *)last->u.dst.next;
2356                last->child_mtu_cached = mtu;
2357        }
2358
2359        return 1;
2360}
2361
2362EXPORT_SYMBOL(xfrm_bundle_ok);
2363
2364int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
2365{
2366        struct net *net;
2367        int err = 0;
2368        if (unlikely(afinfo == NULL))
2369                return -EINVAL;
2370        if (unlikely(afinfo->family >= NPROTO))
2371                return -EAFNOSUPPORT;
2372        write_lock_bh(&xfrm_policy_afinfo_lock);
2373        if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
2374                err = -ENOBUFS;
2375        else {
2376                struct dst_ops *dst_ops = afinfo->dst_ops;
2377                if (likely(dst_ops->kmem_cachep == NULL))
2378                        dst_ops->kmem_cachep = xfrm_dst_cache;
2379                if (likely(dst_ops->check == NULL))
2380                        dst_ops->check = xfrm_dst_check;
2381                if (likely(dst_ops->negative_advice == NULL))
2382                        dst_ops->negative_advice = xfrm_negative_advice;
2383                if (likely(dst_ops->link_failure == NULL))
2384                        dst_ops->link_failure = xfrm_link_failure;
2385                if (likely(afinfo->garbage_collect == NULL))
2386                        afinfo->garbage_collect = __xfrm_garbage_collect;
2387                xfrm_policy_afinfo[afinfo->family] = afinfo;
2388        }
2389        write_unlock_bh(&xfrm_policy_afinfo_lock);
2390
2391        rtnl_lock();
2392        for_each_net(net) {
2393                struct dst_ops *xfrm_dst_ops;
2394
2395                switch (afinfo->family) {
2396                case AF_INET:
2397                        xfrm_dst_ops = &net->xfrm.xfrm4_dst_ops;
2398                        break;
2399#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
2400                case AF_INET6:
2401                        xfrm_dst_ops = &net->xfrm.xfrm6_dst_ops;
2402                        break;
2403#endif
2404                default:
2405                        BUG();
2406                }
2407                *xfrm_dst_ops = *afinfo->dst_ops;
2408        }
2409        rtnl_unlock();
2410
2411        return err;
2412}
2413EXPORT_SYMBOL(xfrm_policy_register_afinfo);
2414
2415int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
2416{
2417        int err = 0;
2418        if (unlikely(afinfo == NULL))
2419                return -EINVAL;
2420        if (unlikely(afinfo->family >= NPROTO))
2421                return -EAFNOSUPPORT;
2422        write_lock_bh(&xfrm_policy_afinfo_lock);
2423        if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
2424                if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
2425                        err = -EINVAL;
2426                else {
2427                        struct dst_ops *dst_ops = afinfo->dst_ops;
2428                        xfrm_policy_afinfo[afinfo->family] = NULL;
2429                        dst_ops->kmem_cachep = NULL;
2430                        dst_ops->check = NULL;
2431                        dst_ops->negative_advice = NULL;
2432                        dst_ops->link_failure = NULL;
2433                        afinfo->garbage_collect = NULL;
2434                }
2435        }
2436        write_unlock_bh(&xfrm_policy_afinfo_lock);
2437        return err;
2438}
2439EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
2440
2441static void __net_init xfrm_dst_ops_init(struct net *net)
2442{
2443        struct xfrm_policy_afinfo *afinfo;
2444
2445        read_lock_bh(&xfrm_policy_afinfo_lock);
2446        afinfo = xfrm_policy_afinfo[AF_INET];
2447        if (afinfo)
2448                net->xfrm.xfrm4_dst_ops = *afinfo->dst_ops;
2449#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
2450        afinfo = xfrm_policy_afinfo[AF_INET6];
2451        if (afinfo)
2452                net->xfrm.xfrm6_dst_ops = *afinfo->dst_ops;
2453#endif
2454        read_unlock_bh(&xfrm_policy_afinfo_lock);
2455}
2456
2457static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
2458{
2459        struct xfrm_policy_afinfo *afinfo;
2460        if (unlikely(family >= NPROTO))
2461                return NULL;
2462        read_lock(&xfrm_policy_afinfo_lock);
2463        afinfo = xfrm_policy_afinfo[family];
2464        if (unlikely(!afinfo))
2465                read_unlock(&xfrm_policy_afinfo_lock);
2466        return afinfo;
2467}
2468
2469static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
2470{
2471        read_unlock(&xfrm_policy_afinfo_lock);
2472}
2473
2474static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
2475{
2476        struct net_device *dev = ptr;
2477
2478        switch (event) {
2479        case NETDEV_DOWN:
2480                __xfrm_garbage_collect(dev_net(dev));
2481        }
2482        return NOTIFY_DONE;
2483}
2484
2485static struct notifier_block xfrm_dev_notifier = {
2486        .notifier_call  = xfrm_dev_event,
2487};
2488
2489#ifdef CONFIG_XFRM_STATISTICS
2490static int __net_init xfrm_statistics_init(struct net *net)
2491{
2492        int rv;
2493
2494        if (snmp_mib_init((void __percpu **)net->mib.xfrm_statistics,
2495                          sizeof(struct linux_xfrm_mib)) < 0)
2496                return -ENOMEM;
2497        rv = xfrm_proc_init(net);
2498        if (rv < 0)
2499                snmp_mib_free((void __percpu **)net->mib.xfrm_statistics);
2500        return rv;
2501}
2502
2503static void xfrm_statistics_fini(struct net *net)
2504{
2505        xfrm_proc_fini(net);
2506        snmp_mib_free((void __percpu **)net->mib.xfrm_statistics);
2507}
2508#else
2509static int __net_init xfrm_statistics_init(struct net *net)
2510{
2511        return 0;
2512}
2513
2514static void xfrm_statistics_fini(struct net *net)
2515{
2516}
2517#endif
2518
2519static int __net_init xfrm_policy_init(struct net *net)
2520{
2521        unsigned int hmask, sz;
2522        int dir;
2523
2524        if (net_eq(net, &init_net))
2525                xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
2526                                           sizeof(struct xfrm_dst),
2527                                           0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
2528                                           NULL);
2529
2530        hmask = 8 - 1;
2531        sz = (hmask+1) * sizeof(struct hlist_head);
2532
2533        net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
2534        if (!net->xfrm.policy_byidx)
2535                goto out_byidx;
2536        net->xfrm.policy_idx_hmask = hmask;
2537
2538        for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
2539                struct xfrm_policy_hash *htab;
2540
2541                net->xfrm.policy_count[dir] = 0;
2542                INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
2543
2544                htab = &net->xfrm.policy_bydst[dir];
2545                htab->table = xfrm_hash_alloc(sz);
2546                if (!htab->table)
2547                        goto out_bydst;
2548                htab->hmask = hmask;
2549        }
2550
2551        INIT_LIST_HEAD(&net->xfrm.policy_all);
2552        INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
2553        if (net_eq(net, &init_net))
2554                register_netdevice_notifier(&xfrm_dev_notifier);
2555        return 0;
2556
2557out_bydst:
2558        for (dir--; dir >= 0; dir--) {
2559                struct xfrm_policy_hash *htab;
2560
2561                htab = &net->xfrm.policy_bydst[dir];
2562                xfrm_hash_free(htab->table, sz);
2563        }
2564        xfrm_hash_free(net->xfrm.policy_byidx, sz);
2565out_byidx:
2566        return -ENOMEM;
2567}
2568
2569static void xfrm_policy_fini(struct net *net)
2570{
2571        struct xfrm_audit audit_info;
2572        unsigned int sz;
2573        int dir;
2574
2575        flush_work(&net->xfrm.policy_hash_work);
2576#ifdef CONFIG_XFRM_SUB_POLICY
2577        audit_info.loginuid = -1;
2578        audit_info.sessionid = -1;
2579        audit_info.secid = 0;
2580        xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, &audit_info);
2581#endif
2582        audit_info.loginuid = -1;
2583        audit_info.sessionid = -1;
2584        audit_info.secid = 0;
2585        xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, &audit_info);
2586
2587        WARN_ON(!list_empty(&net->xfrm.policy_all));
2588
2589        for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
2590                struct xfrm_policy_hash *htab;
2591
2592                WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
2593
2594                htab = &net->xfrm.policy_bydst[dir];
2595                sz = (htab->hmask + 1);
2596                WARN_ON(!hlist_empty(htab->table));
2597                xfrm_hash_free(htab->table, sz);
2598        }
2599
2600        sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
2601        WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
2602        xfrm_hash_free(net->xfrm.policy_byidx, sz);
2603}
2604
2605static int __net_init xfrm_net_init(struct net *net)
2606{
2607        int rv;
2608
2609        rv = xfrm_statistics_init(net);
2610        if (rv < 0)
2611                goto out_statistics;
2612        rv = xfrm_state_init(net);
2613        if (rv < 0)
2614                goto out_state;
2615        rv = xfrm_policy_init(net);
2616        if (rv < 0)
2617                goto out_policy;
2618        xfrm_dst_ops_init(net);
2619        rv = xfrm_sysctl_init(net);
2620        if (rv < 0)
2621                goto out_sysctl;
2622        return 0;
2623
2624out_sysctl:
2625        xfrm_policy_fini(net);
2626out_policy:
2627        xfrm_state_fini(net);
2628out_state:
2629        xfrm_statistics_fini(net);
2630out_statistics:
2631        return rv;
2632}
2633
2634static void __net_exit xfrm_net_exit(struct net *net)
2635{
2636        xfrm_sysctl_fini(net);
2637        xfrm_policy_fini(net);
2638        xfrm_state_fini(net);
2639        xfrm_statistics_fini(net);
2640}
2641
2642static struct pernet_operations __net_initdata xfrm_net_ops = {
2643        .init = xfrm_net_init,
2644        .exit = xfrm_net_exit,
2645};
2646
2647void __init xfrm_init(void)
2648{
2649        register_pernet_subsys(&xfrm_net_ops);
2650        xfrm_input_init();
2651}
2652
2653#ifdef CONFIG_AUDITSYSCALL
2654static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
2655                                         struct audit_buffer *audit_buf)
2656{
2657        struct xfrm_sec_ctx *ctx = xp->security;
2658        struct xfrm_selector *sel = &xp->selector;
2659
2660        if (ctx)
2661                audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
2662                                 ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
2663
2664        switch(sel->family) {
2665        case AF_INET:
2666                audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
2667                if (sel->prefixlen_s != 32)
2668                        audit_log_format(audit_buf, " src_prefixlen=%d",
2669                                         sel->prefixlen_s);
2670                audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
2671                if (sel->prefixlen_d != 32)
2672                        audit_log_format(audit_buf, " dst_prefixlen=%d",
2673                                         sel->prefixlen_d);
2674                break;
2675        case AF_INET6:
2676                audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
2677                if (sel->prefixlen_s != 128)
2678                        audit_log_format(audit_buf, " src_prefixlen=%d",
2679                                         sel->prefixlen_s);
2680                audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
2681                if (sel->prefixlen_d != 128)
2682                        audit_log_format(audit_buf, " dst_prefixlen=%d",
2683                                         sel->prefixlen_d);
2684                break;
2685        }
2686}
2687
2688void xfrm_audit_policy_add(struct xfrm_policy *xp, int result,
2689                           uid_t auid, u32 sessionid, u32 secid)
2690{
2691        struct audit_buffer *audit_buf;
2692
2693        audit_buf = xfrm_audit_start("SPD-add");
2694        if (audit_buf == NULL)
2695                return;
2696        xfrm_audit_helper_usrinfo(auid, sessionid, secid, audit_buf);
2697        audit_log_format(audit_buf, " res=%u", result);
2698        xfrm_audit_common_policyinfo(xp, audit_buf);
2699        audit_log_end(audit_buf);
2700}
2701EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
2702
2703void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
2704                              uid_t auid, u32 sessionid, u32 secid)
2705{
2706        struct audit_buffer *audit_buf;
2707
2708        audit_buf = xfrm_audit_start("SPD-delete");
2709        if (audit_buf == NULL)
2710                return;
2711        xfrm_audit_helper_usrinfo(auid, sessionid, secid, audit_buf);
2712        audit_log_format(audit_buf, " res=%u", result);
2713        xfrm_audit_common_policyinfo(xp, audit_buf);
2714        audit_log_end(audit_buf);
2715}
2716EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
2717#endif
2718
2719#ifdef CONFIG_XFRM_MIGRATE
2720static int xfrm_migrate_selector_match(struct xfrm_selector *sel_cmp,
2721                                       struct xfrm_selector *sel_tgt)
2722{
2723        if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
2724                if (sel_tgt->family == sel_cmp->family &&
2725                    xfrm_addr_cmp(&sel_tgt->daddr, &sel_cmp->daddr,
2726                                  sel_cmp->family) == 0 &&
2727                    xfrm_addr_cmp(&sel_tgt->saddr, &sel_cmp->saddr,
2728                                  sel_cmp->family) == 0 &&
2729                    sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
2730                    sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
2731                        return 1;
2732                }
2733        } else {
2734                if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
2735                        return 1;
2736                }
2737        }
2738        return 0;
2739}
2740
2741static struct xfrm_policy * xfrm_migrate_policy_find(struct xfrm_selector *sel,
2742                                                     u8 dir, u8 type)
2743{
2744        struct xfrm_policy *pol, *ret = NULL;
2745        struct hlist_node *entry;
2746        struct hlist_head *chain;
2747        u32 priority = ~0U;
2748
2749        read_lock_bh(&xfrm_policy_lock);
2750        chain = policy_hash_direct(&init_net, &sel->daddr, &sel->saddr, sel->family, dir);
2751        hlist_for_each_entry(pol, entry, chain, bydst) {
2752                if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2753                    pol->type == type) {
2754                        ret = pol;
2755                        priority = ret->priority;
2756                        break;
2757                }
2758        }
2759        chain = &init_net.xfrm.policy_inexact[dir];
2760        hlist_for_each_entry(pol, entry, chain, bydst) {
2761                if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2762                    pol->type == type &&
2763                    pol->priority < priority) {
2764                        ret = pol;
2765                        break;
2766                }
2767        }
2768
2769        if (ret)
2770                xfrm_pol_hold(ret);
2771
2772        read_unlock_bh(&xfrm_policy_lock);
2773
2774        return ret;
2775}
2776
2777static int migrate_tmpl_match(struct xfrm_migrate *m, struct xfrm_tmpl *t)
2778{
2779        int match = 0;
2780
2781        if (t->mode == m->mode && t->id.proto == m->proto &&
2782            (m->reqid == 0 || t->reqid == m->reqid)) {
2783                switch (t->mode) {
2784                case XFRM_MODE_TUNNEL:
2785                case XFRM_MODE_BEET:
2786                        if (xfrm_addr_cmp(&t->id.daddr, &m->old_daddr,
2787                                          m->old_family) == 0 &&
2788                            xfrm_addr_cmp(&t->saddr, &m->old_saddr,
2789                                          m->old_family) == 0) {
2790                                match = 1;
2791                        }
2792                        break;
2793                case XFRM_MODE_TRANSPORT:
2794                        /* in case of transport mode, template does not store
2795                           any IP addresses, hence we just compare mode and
2796                           protocol */
2797                        match = 1;
2798                        break;
2799                default:
2800                        break;
2801                }
2802        }
2803        return match;
2804}
2805
2806/* update endpoint address(es) of template(s) */
2807static int xfrm_policy_migrate(struct xfrm_policy *pol,
2808                               struct xfrm_migrate *m, int num_migrate)
2809{
2810        struct xfrm_migrate *mp;
2811        int i, j, n = 0;
2812
2813        write_lock_bh(&pol->lock);
2814        if (unlikely(pol->walk.dead)) {
2815                /* target policy has been deleted */
2816                write_unlock_bh(&pol->lock);
2817                return -ENOENT;
2818        }
2819
2820        for (i = 0; i < pol->xfrm_nr; i++) {
2821                for (j = 0, mp = m; j < num_migrate; j++, mp++) {
2822                        if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
2823                                continue;
2824                        n++;
2825                        if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
2826                            pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
2827                                continue;
2828                        /* update endpoints */
2829                        memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
2830                               sizeof(pol->xfrm_vec[i].id.daddr));
2831                        memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
2832                               sizeof(pol->xfrm_vec[i].saddr));
2833                        pol->xfrm_vec[i].encap_family = mp->new_family;
2834                        /* flush bundles */
2835                        atomic_inc(&pol->genid);
2836                }
2837        }
2838
2839        write_unlock_bh(&pol->lock);
2840
2841        if (!n)
2842                return -ENODATA;
2843
2844        return 0;
2845}
2846
2847static int xfrm_migrate_check(struct xfrm_migrate *m, int num_migrate)
2848{
2849        int i, j;
2850
2851        if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
2852                return -EINVAL;
2853
2854        for (i = 0; i < num_migrate; i++) {
2855                if ((xfrm_addr_cmp(&m[i].old_daddr, &m[i].new_daddr,
2856                                   m[i].old_family) == 0) &&
2857                    (xfrm_addr_cmp(&m[i].old_saddr, &m[i].new_saddr,
2858                                   m[i].old_family) == 0))
2859                        return -EINVAL;
2860                if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
2861                    xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
2862                        return -EINVAL;
2863
2864                /* check if there is any duplicated entry */
2865                for (j = i + 1; j < num_migrate; j++) {
2866                        if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
2867                                    sizeof(m[i].old_daddr)) &&
2868                            !memcmp(&m[i].old_saddr, &m[j].old_saddr,
2869                                    sizeof(m[i].old_saddr)) &&
2870                            m[i].proto == m[j].proto &&
2871                            m[i].mode == m[j].mode &&
2872                            m[i].reqid == m[j].reqid &&
2873                            m[i].old_family == m[j].old_family)
2874                                return -EINVAL;
2875                }
2876        }
2877
2878        return 0;
2879}
2880
2881int xfrm_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
2882                 struct xfrm_migrate *m, int num_migrate,
2883                 struct xfrm_kmaddress *k)
2884{
2885        int i, err, nx_cur = 0, nx_new = 0;
2886        struct xfrm_policy *pol = NULL;
2887        struct xfrm_state *x, *xc;
2888        struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
2889        struct xfrm_state *x_new[XFRM_MAX_DEPTH];
2890        struct xfrm_migrate *mp;
2891
2892        if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
2893                goto out;
2894
2895        /* Stage 1 - find policy */
2896        if ((pol = xfrm_migrate_policy_find(sel, dir, type)) == NULL) {
2897                err = -ENOENT;
2898                goto out;
2899        }
2900
2901        /* Stage 2 - find and update state(s) */
2902        for (i = 0, mp = m; i < num_migrate; i++, mp++) {
2903                if ((x = xfrm_migrate_state_find(mp))) {
2904                        x_cur[nx_cur] = x;
2905                        nx_cur++;
2906                        if ((xc = xfrm_state_migrate(x, mp))) {
2907                                x_new[nx_new] = xc;
2908                                nx_new++;
2909                        } else {
2910                                err = -ENODATA;
2911                                goto restore_state;
2912                        }
2913                }
2914        }
2915
2916        /* Stage 3 - update policy */
2917        if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
2918                goto restore_state;
2919
2920        /* Stage 4 - delete old state(s) */
2921        if (nx_cur) {
2922                xfrm_states_put(x_cur, nx_cur);
2923                xfrm_states_delete(x_cur, nx_cur);
2924        }
2925
2926        /* Stage 5 - announce */
2927        km_migrate(sel, dir, type, m, num_migrate, k);
2928
2929        xfrm_pol_put(pol);
2930
2931        return 0;
2932out:
2933        return err;
2934
2935restore_state:
2936        if (pol)
2937                xfrm_pol_put(pol);
2938        if (nx_cur)
2939                xfrm_states_put(x_cur, nx_cur);
2940        if (nx_new)
2941                xfrm_states_delete(x_new, nx_new);
2942
2943        return err;
2944}
2945EXPORT_SYMBOL(xfrm_migrate);
2946#endif
2947