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