linux/net/netfilter/x_tables.c
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   1/*
   2 * x_tables core - Backend for {ip,ip6,arp}_tables
   3 *
   4 * Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
   5 * Copyright (C) 2006-2012 Patrick McHardy <kaber@trash.net>
   6 *
   7 * Based on existing ip_tables code which is
   8 *   Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
   9 *   Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
  10 *
  11 * This program is free software; you can redistribute it and/or modify
  12 * it under the terms of the GNU General Public License version 2 as
  13 * published by the Free Software Foundation.
  14 *
  15 */
  16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17#include <linux/kernel.h>
  18#include <linux/module.h>
  19#include <linux/socket.h>
  20#include <linux/net.h>
  21#include <linux/proc_fs.h>
  22#include <linux/seq_file.h>
  23#include <linux/string.h>
  24#include <linux/vmalloc.h>
  25#include <linux/mutex.h>
  26#include <linux/mm.h>
  27#include <linux/slab.h>
  28#include <linux/audit.h>
  29#include <net/net_namespace.h>
  30
  31#include <linux/netfilter/x_tables.h>
  32#include <linux/netfilter_arp.h>
  33#include <linux/netfilter_ipv4/ip_tables.h>
  34#include <linux/netfilter_ipv6/ip6_tables.h>
  35#include <linux/netfilter_arp/arp_tables.h>
  36
  37MODULE_LICENSE("GPL");
  38MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
  39MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module");
  40
  41#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
  42
  43struct compat_delta {
  44        unsigned int offset; /* offset in kernel */
  45        int delta; /* delta in 32bit user land */
  46};
  47
  48struct xt_af {
  49        struct mutex mutex;
  50        struct list_head match;
  51        struct list_head target;
  52#ifdef CONFIG_COMPAT
  53        struct mutex compat_mutex;
  54        struct compat_delta *compat_tab;
  55        unsigned int number; /* number of slots in compat_tab[] */
  56        unsigned int cur; /* number of used slots in compat_tab[] */
  57#endif
  58};
  59
  60static struct xt_af *xt;
  61
  62static const char *const xt_prefix[NFPROTO_NUMPROTO] = {
  63        [NFPROTO_UNSPEC] = "x",
  64        [NFPROTO_IPV4]   = "ip",
  65        [NFPROTO_ARP]    = "arp",
  66        [NFPROTO_BRIDGE] = "eb",
  67        [NFPROTO_IPV6]   = "ip6",
  68};
  69
  70/* Allow this many total (re)entries. */
  71static const unsigned int xt_jumpstack_multiplier = 2;
  72
  73/* Registration hooks for targets. */
  74int
  75xt_register_target(struct xt_target *target)
  76{
  77        u_int8_t af = target->family;
  78        int ret;
  79
  80        ret = mutex_lock_interruptible(&xt[af].mutex);
  81        if (ret != 0)
  82                return ret;
  83        list_add(&target->list, &xt[af].target);
  84        mutex_unlock(&xt[af].mutex);
  85        return ret;
  86}
  87EXPORT_SYMBOL(xt_register_target);
  88
  89void
  90xt_unregister_target(struct xt_target *target)
  91{
  92        u_int8_t af = target->family;
  93
  94        mutex_lock(&xt[af].mutex);
  95        list_del(&target->list);
  96        mutex_unlock(&xt[af].mutex);
  97}
  98EXPORT_SYMBOL(xt_unregister_target);
  99
 100int
 101xt_register_targets(struct xt_target *target, unsigned int n)
 102{
 103        unsigned int i;
 104        int err = 0;
 105
 106        for (i = 0; i < n; i++) {
 107                err = xt_register_target(&target[i]);
 108                if (err)
 109                        goto err;
 110        }
 111        return err;
 112
 113err:
 114        if (i > 0)
 115                xt_unregister_targets(target, i);
 116        return err;
 117}
 118EXPORT_SYMBOL(xt_register_targets);
 119
 120void
 121xt_unregister_targets(struct xt_target *target, unsigned int n)
 122{
 123        while (n-- > 0)
 124                xt_unregister_target(&target[n]);
 125}
 126EXPORT_SYMBOL(xt_unregister_targets);
 127
 128int
 129xt_register_match(struct xt_match *match)
 130{
 131        u_int8_t af = match->family;
 132        int ret;
 133
 134        ret = mutex_lock_interruptible(&xt[af].mutex);
 135        if (ret != 0)
 136                return ret;
 137
 138        list_add(&match->list, &xt[af].match);
 139        mutex_unlock(&xt[af].mutex);
 140
 141        return ret;
 142}
 143EXPORT_SYMBOL(xt_register_match);
 144
 145void
 146xt_unregister_match(struct xt_match *match)
 147{
 148        u_int8_t af = match->family;
 149
 150        mutex_lock(&xt[af].mutex);
 151        list_del(&match->list);
 152        mutex_unlock(&xt[af].mutex);
 153}
 154EXPORT_SYMBOL(xt_unregister_match);
 155
 156int
 157xt_register_matches(struct xt_match *match, unsigned int n)
 158{
 159        unsigned int i;
 160        int err = 0;
 161
 162        for (i = 0; i < n; i++) {
 163                err = xt_register_match(&match[i]);
 164                if (err)
 165                        goto err;
 166        }
 167        return err;
 168
 169err:
 170        if (i > 0)
 171                xt_unregister_matches(match, i);
 172        return err;
 173}
 174EXPORT_SYMBOL(xt_register_matches);
 175
 176void
 177xt_unregister_matches(struct xt_match *match, unsigned int n)
 178{
 179        while (n-- > 0)
 180                xt_unregister_match(&match[n]);
 181}
 182EXPORT_SYMBOL(xt_unregister_matches);
 183
 184
 185/*
 186 * These are weird, but module loading must not be done with mutex
 187 * held (since they will register), and we have to have a single
 188 * function to use.
 189 */
 190
 191/* Find match, grabs ref.  Returns ERR_PTR() on error. */
 192struct xt_match *xt_find_match(u8 af, const char *name, u8 revision)
 193{
 194        struct xt_match *m;
 195        int err = -ENOENT;
 196
 197        if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 198                return ERR_PTR(-EINTR);
 199
 200        list_for_each_entry(m, &xt[af].match, list) {
 201                if (strcmp(m->name, name) == 0) {
 202                        if (m->revision == revision) {
 203                                if (try_module_get(m->me)) {
 204                                        mutex_unlock(&xt[af].mutex);
 205                                        return m;
 206                                }
 207                        } else
 208                                err = -EPROTOTYPE; /* Found something. */
 209                }
 210        }
 211        mutex_unlock(&xt[af].mutex);
 212
 213        if (af != NFPROTO_UNSPEC)
 214                /* Try searching again in the family-independent list */
 215                return xt_find_match(NFPROTO_UNSPEC, name, revision);
 216
 217        return ERR_PTR(err);
 218}
 219EXPORT_SYMBOL(xt_find_match);
 220
 221struct xt_match *
 222xt_request_find_match(uint8_t nfproto, const char *name, uint8_t revision)
 223{
 224        struct xt_match *match;
 225
 226        match = xt_find_match(nfproto, name, revision);
 227        if (IS_ERR(match)) {
 228                request_module("%st_%s", xt_prefix[nfproto], name);
 229                match = xt_find_match(nfproto, name, revision);
 230        }
 231
 232        return match;
 233}
 234EXPORT_SYMBOL_GPL(xt_request_find_match);
 235
 236/* Find target, grabs ref.  Returns ERR_PTR() on error. */
 237struct xt_target *xt_find_target(u8 af, const char *name, u8 revision)
 238{
 239        struct xt_target *t;
 240        int err = -ENOENT;
 241
 242        if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 243                return ERR_PTR(-EINTR);
 244
 245        list_for_each_entry(t, &xt[af].target, list) {
 246                if (strcmp(t->name, name) == 0) {
 247                        if (t->revision == revision) {
 248                                if (try_module_get(t->me)) {
 249                                        mutex_unlock(&xt[af].mutex);
 250                                        return t;
 251                                }
 252                        } else
 253                                err = -EPROTOTYPE; /* Found something. */
 254                }
 255        }
 256        mutex_unlock(&xt[af].mutex);
 257
 258        if (af != NFPROTO_UNSPEC)
 259                /* Try searching again in the family-independent list */
 260                return xt_find_target(NFPROTO_UNSPEC, name, revision);
 261
 262        return ERR_PTR(err);
 263}
 264EXPORT_SYMBOL(xt_find_target);
 265
 266struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision)
 267{
 268        struct xt_target *target;
 269
 270        target = xt_find_target(af, name, revision);
 271        if (IS_ERR(target)) {
 272                request_module("%st_%s", xt_prefix[af], name);
 273                target = xt_find_target(af, name, revision);
 274        }
 275
 276        return target;
 277}
 278EXPORT_SYMBOL_GPL(xt_request_find_target);
 279
 280static int match_revfn(u8 af, const char *name, u8 revision, int *bestp)
 281{
 282        const struct xt_match *m;
 283        int have_rev = 0;
 284
 285        list_for_each_entry(m, &xt[af].match, list) {
 286                if (strcmp(m->name, name) == 0) {
 287                        if (m->revision > *bestp)
 288                                *bestp = m->revision;
 289                        if (m->revision == revision)
 290                                have_rev = 1;
 291                }
 292        }
 293
 294        if (af != NFPROTO_UNSPEC && !have_rev)
 295                return match_revfn(NFPROTO_UNSPEC, name, revision, bestp);
 296
 297        return have_rev;
 298}
 299
 300static int target_revfn(u8 af, const char *name, u8 revision, int *bestp)
 301{
 302        const struct xt_target *t;
 303        int have_rev = 0;
 304
 305        list_for_each_entry(t, &xt[af].target, list) {
 306                if (strcmp(t->name, name) == 0) {
 307                        if (t->revision > *bestp)
 308                                *bestp = t->revision;
 309                        if (t->revision == revision)
 310                                have_rev = 1;
 311                }
 312        }
 313
 314        if (af != NFPROTO_UNSPEC && !have_rev)
 315                return target_revfn(NFPROTO_UNSPEC, name, revision, bestp);
 316
 317        return have_rev;
 318}
 319
 320/* Returns true or false (if no such extension at all) */
 321int xt_find_revision(u8 af, const char *name, u8 revision, int target,
 322                     int *err)
 323{
 324        int have_rev, best = -1;
 325
 326        if (mutex_lock_interruptible(&xt[af].mutex) != 0) {
 327                *err = -EINTR;
 328                return 1;
 329        }
 330        if (target == 1)
 331                have_rev = target_revfn(af, name, revision, &best);
 332        else
 333                have_rev = match_revfn(af, name, revision, &best);
 334        mutex_unlock(&xt[af].mutex);
 335
 336        /* Nothing at all?  Return 0 to try loading module. */
 337        if (best == -1) {
 338                *err = -ENOENT;
 339                return 0;
 340        }
 341
 342        *err = best;
 343        if (!have_rev)
 344                *err = -EPROTONOSUPPORT;
 345        return 1;
 346}
 347EXPORT_SYMBOL_GPL(xt_find_revision);
 348
 349static char *
 350textify_hooks(char *buf, size_t size, unsigned int mask, uint8_t nfproto)
 351{
 352        static const char *const inetbr_names[] = {
 353                "PREROUTING", "INPUT", "FORWARD",
 354                "OUTPUT", "POSTROUTING", "BROUTING",
 355        };
 356        static const char *const arp_names[] = {
 357                "INPUT", "FORWARD", "OUTPUT",
 358        };
 359        const char *const *names;
 360        unsigned int i, max;
 361        char *p = buf;
 362        bool np = false;
 363        int res;
 364
 365        names = (nfproto == NFPROTO_ARP) ? arp_names : inetbr_names;
 366        max   = (nfproto == NFPROTO_ARP) ? ARRAY_SIZE(arp_names) :
 367                                           ARRAY_SIZE(inetbr_names);
 368        *p = '\0';
 369        for (i = 0; i < max; ++i) {
 370                if (!(mask & (1 << i)))
 371                        continue;
 372                res = snprintf(p, size, "%s%s", np ? "/" : "", names[i]);
 373                if (res > 0) {
 374                        size -= res;
 375                        p += res;
 376                }
 377                np = true;
 378        }
 379
 380        return buf;
 381}
 382
 383int xt_check_match(struct xt_mtchk_param *par,
 384                   unsigned int size, u_int8_t proto, bool inv_proto)
 385{
 386        int ret;
 387
 388        if (XT_ALIGN(par->match->matchsize) != size &&
 389            par->match->matchsize != -1) {
 390                /*
 391                 * ebt_among is exempt from centralized matchsize checking
 392                 * because it uses a dynamic-size data set.
 393                 */
 394                pr_err("%s_tables: %s.%u match: invalid size "
 395                       "%u (kernel) != (user) %u\n",
 396                       xt_prefix[par->family], par->match->name,
 397                       par->match->revision,
 398                       XT_ALIGN(par->match->matchsize), size);
 399                return -EINVAL;
 400        }
 401        if (par->match->table != NULL &&
 402            strcmp(par->match->table, par->table) != 0) {
 403                pr_err("%s_tables: %s match: only valid in %s table, not %s\n",
 404                       xt_prefix[par->family], par->match->name,
 405                       par->match->table, par->table);
 406                return -EINVAL;
 407        }
 408        if (par->match->hooks && (par->hook_mask & ~par->match->hooks) != 0) {
 409                char used[64], allow[64];
 410
 411                pr_err("%s_tables: %s match: used from hooks %s, but only "
 412                       "valid from %s\n",
 413                       xt_prefix[par->family], par->match->name,
 414                       textify_hooks(used, sizeof(used), par->hook_mask,
 415                                     par->family),
 416                       textify_hooks(allow, sizeof(allow), par->match->hooks,
 417                                     par->family));
 418                return -EINVAL;
 419        }
 420        if (par->match->proto && (par->match->proto != proto || inv_proto)) {
 421                pr_err("%s_tables: %s match: only valid for protocol %u\n",
 422                       xt_prefix[par->family], par->match->name,
 423                       par->match->proto);
 424                return -EINVAL;
 425        }
 426        if (par->match->checkentry != NULL) {
 427                ret = par->match->checkentry(par);
 428                if (ret < 0)
 429                        return ret;
 430                else if (ret > 0)
 431                        /* Flag up potential errors. */
 432                        return -EIO;
 433        }
 434        return 0;
 435}
 436EXPORT_SYMBOL_GPL(xt_check_match);
 437
 438#ifdef CONFIG_COMPAT
 439int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta)
 440{
 441        struct xt_af *xp = &xt[af];
 442
 443        if (!xp->compat_tab) {
 444                if (!xp->number)
 445                        return -EINVAL;
 446                xp->compat_tab = vmalloc(sizeof(struct compat_delta) * xp->number);
 447                if (!xp->compat_tab)
 448                        return -ENOMEM;
 449                xp->cur = 0;
 450        }
 451
 452        if (xp->cur >= xp->number)
 453                return -EINVAL;
 454
 455        if (xp->cur)
 456                delta += xp->compat_tab[xp->cur - 1].delta;
 457        xp->compat_tab[xp->cur].offset = offset;
 458        xp->compat_tab[xp->cur].delta = delta;
 459        xp->cur++;
 460        return 0;
 461}
 462EXPORT_SYMBOL_GPL(xt_compat_add_offset);
 463
 464void xt_compat_flush_offsets(u_int8_t af)
 465{
 466        if (xt[af].compat_tab) {
 467                vfree(xt[af].compat_tab);
 468                xt[af].compat_tab = NULL;
 469                xt[af].number = 0;
 470                xt[af].cur = 0;
 471        }
 472}
 473EXPORT_SYMBOL_GPL(xt_compat_flush_offsets);
 474
 475int xt_compat_calc_jump(u_int8_t af, unsigned int offset)
 476{
 477        struct compat_delta *tmp = xt[af].compat_tab;
 478        int mid, left = 0, right = xt[af].cur - 1;
 479
 480        while (left <= right) {
 481                mid = (left + right) >> 1;
 482                if (offset > tmp[mid].offset)
 483                        left = mid + 1;
 484                else if (offset < tmp[mid].offset)
 485                        right = mid - 1;
 486                else
 487                        return mid ? tmp[mid - 1].delta : 0;
 488        }
 489        return left ? tmp[left - 1].delta : 0;
 490}
 491EXPORT_SYMBOL_GPL(xt_compat_calc_jump);
 492
 493void xt_compat_init_offsets(u_int8_t af, unsigned int number)
 494{
 495        xt[af].number = number;
 496        xt[af].cur = 0;
 497}
 498EXPORT_SYMBOL(xt_compat_init_offsets);
 499
 500int xt_compat_match_offset(const struct xt_match *match)
 501{
 502        u_int16_t csize = match->compatsize ? : match->matchsize;
 503        return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
 504}
 505EXPORT_SYMBOL_GPL(xt_compat_match_offset);
 506
 507int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
 508                              unsigned int *size)
 509{
 510        const struct xt_match *match = m->u.kernel.match;
 511        struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
 512        int pad, off = xt_compat_match_offset(match);
 513        u_int16_t msize = cm->u.user.match_size;
 514
 515        m = *dstptr;
 516        memcpy(m, cm, sizeof(*cm));
 517        if (match->compat_from_user)
 518                match->compat_from_user(m->data, cm->data);
 519        else
 520                memcpy(m->data, cm->data, msize - sizeof(*cm));
 521        pad = XT_ALIGN(match->matchsize) - match->matchsize;
 522        if (pad > 0)
 523                memset(m->data + match->matchsize, 0, pad);
 524
 525        msize += off;
 526        m->u.user.match_size = msize;
 527
 528        *size += off;
 529        *dstptr += msize;
 530        return 0;
 531}
 532EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
 533
 534int xt_compat_match_to_user(const struct xt_entry_match *m,
 535                            void __user **dstptr, unsigned int *size)
 536{
 537        const struct xt_match *match = m->u.kernel.match;
 538        struct compat_xt_entry_match __user *cm = *dstptr;
 539        int off = xt_compat_match_offset(match);
 540        u_int16_t msize = m->u.user.match_size - off;
 541
 542        if (copy_to_user(cm, m, sizeof(*cm)) ||
 543            put_user(msize, &cm->u.user.match_size) ||
 544            copy_to_user(cm->u.user.name, m->u.kernel.match->name,
 545                         strlen(m->u.kernel.match->name) + 1))
 546                return -EFAULT;
 547
 548        if (match->compat_to_user) {
 549                if (match->compat_to_user((void __user *)cm->data, m->data))
 550                        return -EFAULT;
 551        } else {
 552                if (copy_to_user(cm->data, m->data, msize - sizeof(*cm)))
 553                        return -EFAULT;
 554        }
 555
 556        *size -= off;
 557        *dstptr += msize;
 558        return 0;
 559}
 560EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
 561#endif /* CONFIG_COMPAT */
 562
 563int xt_check_target(struct xt_tgchk_param *par,
 564                    unsigned int size, u_int8_t proto, bool inv_proto)
 565{
 566        int ret;
 567
 568        if (XT_ALIGN(par->target->targetsize) != size) {
 569                pr_err("%s_tables: %s.%u target: invalid size "
 570                       "%u (kernel) != (user) %u\n",
 571                       xt_prefix[par->family], par->target->name,
 572                       par->target->revision,
 573                       XT_ALIGN(par->target->targetsize), size);
 574                return -EINVAL;
 575        }
 576        if (par->target->table != NULL &&
 577            strcmp(par->target->table, par->table) != 0) {
 578                pr_err("%s_tables: %s target: only valid in %s table, not %s\n",
 579                       xt_prefix[par->family], par->target->name,
 580                       par->target->table, par->table);
 581                return -EINVAL;
 582        }
 583        if (par->target->hooks && (par->hook_mask & ~par->target->hooks) != 0) {
 584                char used[64], allow[64];
 585
 586                pr_err("%s_tables: %s target: used from hooks %s, but only "
 587                       "usable from %s\n",
 588                       xt_prefix[par->family], par->target->name,
 589                       textify_hooks(used, sizeof(used), par->hook_mask,
 590                                     par->family),
 591                       textify_hooks(allow, sizeof(allow), par->target->hooks,
 592                                     par->family));
 593                return -EINVAL;
 594        }
 595        if (par->target->proto && (par->target->proto != proto || inv_proto)) {
 596                pr_err("%s_tables: %s target: only valid for protocol %u\n",
 597                       xt_prefix[par->family], par->target->name,
 598                       par->target->proto);
 599                return -EINVAL;
 600        }
 601        if (par->target->checkentry != NULL) {
 602                ret = par->target->checkentry(par);
 603                if (ret < 0)
 604                        return ret;
 605                else if (ret > 0)
 606                        /* Flag up potential errors. */
 607                        return -EIO;
 608        }
 609        return 0;
 610}
 611EXPORT_SYMBOL_GPL(xt_check_target);
 612
 613#ifdef CONFIG_COMPAT
 614int xt_compat_target_offset(const struct xt_target *target)
 615{
 616        u_int16_t csize = target->compatsize ? : target->targetsize;
 617        return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
 618}
 619EXPORT_SYMBOL_GPL(xt_compat_target_offset);
 620
 621void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
 622                                unsigned int *size)
 623{
 624        const struct xt_target *target = t->u.kernel.target;
 625        struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
 626        int pad, off = xt_compat_target_offset(target);
 627        u_int16_t tsize = ct->u.user.target_size;
 628
 629        t = *dstptr;
 630        memcpy(t, ct, sizeof(*ct));
 631        if (target->compat_from_user)
 632                target->compat_from_user(t->data, ct->data);
 633        else
 634                memcpy(t->data, ct->data, tsize - sizeof(*ct));
 635        pad = XT_ALIGN(target->targetsize) - target->targetsize;
 636        if (pad > 0)
 637                memset(t->data + target->targetsize, 0, pad);
 638
 639        tsize += off;
 640        t->u.user.target_size = tsize;
 641
 642        *size += off;
 643        *dstptr += tsize;
 644}
 645EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
 646
 647int xt_compat_target_to_user(const struct xt_entry_target *t,
 648                             void __user **dstptr, unsigned int *size)
 649{
 650        const struct xt_target *target = t->u.kernel.target;
 651        struct compat_xt_entry_target __user *ct = *dstptr;
 652        int off = xt_compat_target_offset(target);
 653        u_int16_t tsize = t->u.user.target_size - off;
 654
 655        if (copy_to_user(ct, t, sizeof(*ct)) ||
 656            put_user(tsize, &ct->u.user.target_size) ||
 657            copy_to_user(ct->u.user.name, t->u.kernel.target->name,
 658                         strlen(t->u.kernel.target->name) + 1))
 659                return -EFAULT;
 660
 661        if (target->compat_to_user) {
 662                if (target->compat_to_user((void __user *)ct->data, t->data))
 663                        return -EFAULT;
 664        } else {
 665                if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct)))
 666                        return -EFAULT;
 667        }
 668
 669        *size -= off;
 670        *dstptr += tsize;
 671        return 0;
 672}
 673EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
 674#endif
 675
 676struct xt_table_info *xt_alloc_table_info(unsigned int size)
 677{
 678        struct xt_table_info *newinfo;
 679        int cpu;
 680
 681        /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
 682        if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages)
 683                return NULL;
 684
 685        newinfo = kzalloc(XT_TABLE_INFO_SZ, GFP_KERNEL);
 686        if (!newinfo)
 687                return NULL;
 688
 689        newinfo->size = size;
 690
 691        for_each_possible_cpu(cpu) {
 692                if (size <= PAGE_SIZE)
 693                        newinfo->entries[cpu] = kmalloc_node(size,
 694                                                        GFP_KERNEL,
 695                                                        cpu_to_node(cpu));
 696                else
 697                        newinfo->entries[cpu] = vmalloc_node(size,
 698                                                        cpu_to_node(cpu));
 699
 700                if (newinfo->entries[cpu] == NULL) {
 701                        xt_free_table_info(newinfo);
 702                        return NULL;
 703                }
 704        }
 705
 706        return newinfo;
 707}
 708EXPORT_SYMBOL(xt_alloc_table_info);
 709
 710void xt_free_table_info(struct xt_table_info *info)
 711{
 712        int cpu;
 713
 714        for_each_possible_cpu(cpu) {
 715                if (info->size <= PAGE_SIZE)
 716                        kfree(info->entries[cpu]);
 717                else
 718                        vfree(info->entries[cpu]);
 719        }
 720
 721        if (info->jumpstack != NULL) {
 722                if (sizeof(void *) * info->stacksize > PAGE_SIZE) {
 723                        for_each_possible_cpu(cpu)
 724                                vfree(info->jumpstack[cpu]);
 725                } else {
 726                        for_each_possible_cpu(cpu)
 727                                kfree(info->jumpstack[cpu]);
 728                }
 729        }
 730
 731        if (sizeof(void **) * nr_cpu_ids > PAGE_SIZE)
 732                vfree(info->jumpstack);
 733        else
 734                kfree(info->jumpstack);
 735
 736        free_percpu(info->stackptr);
 737
 738        kfree(info);
 739}
 740EXPORT_SYMBOL(xt_free_table_info);
 741
 742/* Find table by name, grabs mutex & ref.  Returns ERR_PTR() on error. */
 743struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
 744                                    const char *name)
 745{
 746        struct xt_table *t;
 747
 748        if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 749                return ERR_PTR(-EINTR);
 750
 751        list_for_each_entry(t, &net->xt.tables[af], list)
 752                if (strcmp(t->name, name) == 0 && try_module_get(t->me))
 753                        return t;
 754        mutex_unlock(&xt[af].mutex);
 755        return NULL;
 756}
 757EXPORT_SYMBOL_GPL(xt_find_table_lock);
 758
 759void xt_table_unlock(struct xt_table *table)
 760{
 761        mutex_unlock(&xt[table->af].mutex);
 762}
 763EXPORT_SYMBOL_GPL(xt_table_unlock);
 764
 765#ifdef CONFIG_COMPAT
 766void xt_compat_lock(u_int8_t af)
 767{
 768        mutex_lock(&xt[af].compat_mutex);
 769}
 770EXPORT_SYMBOL_GPL(xt_compat_lock);
 771
 772void xt_compat_unlock(u_int8_t af)
 773{
 774        mutex_unlock(&xt[af].compat_mutex);
 775}
 776EXPORT_SYMBOL_GPL(xt_compat_unlock);
 777#endif
 778
 779DEFINE_PER_CPU(seqcount_t, xt_recseq);
 780EXPORT_PER_CPU_SYMBOL_GPL(xt_recseq);
 781
 782static int xt_jumpstack_alloc(struct xt_table_info *i)
 783{
 784        unsigned int size;
 785        int cpu;
 786
 787        i->stackptr = alloc_percpu(unsigned int);
 788        if (i->stackptr == NULL)
 789                return -ENOMEM;
 790
 791        size = sizeof(void **) * nr_cpu_ids;
 792        if (size > PAGE_SIZE)
 793                i->jumpstack = vzalloc(size);
 794        else
 795                i->jumpstack = kzalloc(size, GFP_KERNEL);
 796        if (i->jumpstack == NULL)
 797                return -ENOMEM;
 798
 799        i->stacksize *= xt_jumpstack_multiplier;
 800        size = sizeof(void *) * i->stacksize;
 801        for_each_possible_cpu(cpu) {
 802                if (size > PAGE_SIZE)
 803                        i->jumpstack[cpu] = vmalloc_node(size,
 804                                cpu_to_node(cpu));
 805                else
 806                        i->jumpstack[cpu] = kmalloc_node(size,
 807                                GFP_KERNEL, cpu_to_node(cpu));
 808                if (i->jumpstack[cpu] == NULL)
 809                        /*
 810                         * Freeing will be done later on by the callers. The
 811                         * chain is: xt_replace_table -> __do_replace ->
 812                         * do_replace -> xt_free_table_info.
 813                         */
 814                        return -ENOMEM;
 815        }
 816
 817        return 0;
 818}
 819
 820struct xt_table_info *
 821xt_replace_table(struct xt_table *table,
 822              unsigned int num_counters,
 823              struct xt_table_info *newinfo,
 824              int *error)
 825{
 826        struct xt_table_info *private;
 827        int ret;
 828
 829        ret = xt_jumpstack_alloc(newinfo);
 830        if (ret < 0) {
 831                *error = ret;
 832                return NULL;
 833        }
 834
 835        /* Do the substitution. */
 836        local_bh_disable();
 837        private = table->private;
 838
 839        /* Check inside lock: is the old number correct? */
 840        if (num_counters != private->number) {
 841                pr_debug("num_counters != table->private->number (%u/%u)\n",
 842                         num_counters, private->number);
 843                local_bh_enable();
 844                *error = -EAGAIN;
 845                return NULL;
 846        }
 847
 848        table->private = newinfo;
 849        newinfo->initial_entries = private->initial_entries;
 850
 851        /*
 852         * Even though table entries have now been swapped, other CPU's
 853         * may still be using the old entries. This is okay, because
 854         * resynchronization happens because of the locking done
 855         * during the get_counters() routine.
 856         */
 857        local_bh_enable();
 858
 859#ifdef CONFIG_AUDIT
 860        if (audit_enabled) {
 861                struct audit_buffer *ab;
 862
 863                ab = audit_log_start(current->audit_context, GFP_KERNEL,
 864                                     AUDIT_NETFILTER_CFG);
 865                if (ab) {
 866                        audit_log_format(ab, "table=%s family=%u entries=%u",
 867                                         table->name, table->af,
 868                                         private->number);
 869                        audit_log_end(ab);
 870                }
 871        }
 872#endif
 873
 874        return private;
 875}
 876EXPORT_SYMBOL_GPL(xt_replace_table);
 877
 878struct xt_table *xt_register_table(struct net *net,
 879                                   const struct xt_table *input_table,
 880                                   struct xt_table_info *bootstrap,
 881                                   struct xt_table_info *newinfo)
 882{
 883        int ret;
 884        struct xt_table_info *private;
 885        struct xt_table *t, *table;
 886
 887        /* Don't add one object to multiple lists. */
 888        table = kmemdup(input_table, sizeof(struct xt_table), GFP_KERNEL);
 889        if (!table) {
 890                ret = -ENOMEM;
 891                goto out;
 892        }
 893
 894        ret = mutex_lock_interruptible(&xt[table->af].mutex);
 895        if (ret != 0)
 896                goto out_free;
 897
 898        /* Don't autoload: we'd eat our tail... */
 899        list_for_each_entry(t, &net->xt.tables[table->af], list) {
 900                if (strcmp(t->name, table->name) == 0) {
 901                        ret = -EEXIST;
 902                        goto unlock;
 903                }
 904        }
 905
 906        /* Simplifies replace_table code. */
 907        table->private = bootstrap;
 908
 909        if (!xt_replace_table(table, 0, newinfo, &ret))
 910                goto unlock;
 911
 912        private = table->private;
 913        pr_debug("table->private->number = %u\n", private->number);
 914
 915        /* save number of initial entries */
 916        private->initial_entries = private->number;
 917
 918        list_add(&table->list, &net->xt.tables[table->af]);
 919        mutex_unlock(&xt[table->af].mutex);
 920        return table;
 921
 922 unlock:
 923        mutex_unlock(&xt[table->af].mutex);
 924out_free:
 925        kfree(table);
 926out:
 927        return ERR_PTR(ret);
 928}
 929EXPORT_SYMBOL_GPL(xt_register_table);
 930
 931void *xt_unregister_table(struct xt_table *table)
 932{
 933        struct xt_table_info *private;
 934
 935        mutex_lock(&xt[table->af].mutex);
 936        private = table->private;
 937        list_del(&table->list);
 938        mutex_unlock(&xt[table->af].mutex);
 939        kfree(table);
 940
 941        return private;
 942}
 943EXPORT_SYMBOL_GPL(xt_unregister_table);
 944
 945#ifdef CONFIG_PROC_FS
 946struct xt_names_priv {
 947        struct seq_net_private p;
 948        u_int8_t af;
 949};
 950static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos)
 951{
 952        struct xt_names_priv *priv = seq->private;
 953        struct net *net = seq_file_net(seq);
 954        u_int8_t af = priv->af;
 955
 956        mutex_lock(&xt[af].mutex);
 957        return seq_list_start(&net->xt.tables[af], *pos);
 958}
 959
 960static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 961{
 962        struct xt_names_priv *priv = seq->private;
 963        struct net *net = seq_file_net(seq);
 964        u_int8_t af = priv->af;
 965
 966        return seq_list_next(v, &net->xt.tables[af], pos);
 967}
 968
 969static void xt_table_seq_stop(struct seq_file *seq, void *v)
 970{
 971        struct xt_names_priv *priv = seq->private;
 972        u_int8_t af = priv->af;
 973
 974        mutex_unlock(&xt[af].mutex);
 975}
 976
 977static int xt_table_seq_show(struct seq_file *seq, void *v)
 978{
 979        struct xt_table *table = list_entry(v, struct xt_table, list);
 980
 981        if (strlen(table->name))
 982                return seq_printf(seq, "%s\n", table->name);
 983        else
 984                return 0;
 985}
 986
 987static const struct seq_operations xt_table_seq_ops = {
 988        .start  = xt_table_seq_start,
 989        .next   = xt_table_seq_next,
 990        .stop   = xt_table_seq_stop,
 991        .show   = xt_table_seq_show,
 992};
 993
 994static int xt_table_open(struct inode *inode, struct file *file)
 995{
 996        int ret;
 997        struct xt_names_priv *priv;
 998
 999        ret = seq_open_net(inode, file, &xt_table_seq_ops,
1000                           sizeof(struct xt_names_priv));
1001        if (!ret) {
1002                priv = ((struct seq_file *)file->private_data)->private;
1003                priv->af = (unsigned long)PDE_DATA(inode);
1004        }
1005        return ret;
1006}
1007
1008static const struct file_operations xt_table_ops = {
1009        .owner   = THIS_MODULE,
1010        .open    = xt_table_open,
1011        .read    = seq_read,
1012        .llseek  = seq_lseek,
1013        .release = seq_release_net,
1014};
1015
1016/*
1017 * Traverse state for ip{,6}_{tables,matches} for helping crossing
1018 * the multi-AF mutexes.
1019 */
1020struct nf_mttg_trav {
1021        struct list_head *head, *curr;
1022        uint8_t class, nfproto;
1023};
1024
1025enum {
1026        MTTG_TRAV_INIT,
1027        MTTG_TRAV_NFP_UNSPEC,
1028        MTTG_TRAV_NFP_SPEC,
1029        MTTG_TRAV_DONE,
1030};
1031
1032static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos,
1033    bool is_target)
1034{
1035        static const uint8_t next_class[] = {
1036                [MTTG_TRAV_NFP_UNSPEC] = MTTG_TRAV_NFP_SPEC,
1037                [MTTG_TRAV_NFP_SPEC]   = MTTG_TRAV_DONE,
1038        };
1039        struct nf_mttg_trav *trav = seq->private;
1040
1041        switch (trav->class) {
1042        case MTTG_TRAV_INIT:
1043                trav->class = MTTG_TRAV_NFP_UNSPEC;
1044                mutex_lock(&xt[NFPROTO_UNSPEC].mutex);
1045                trav->head = trav->curr = is_target ?
1046                        &xt[NFPROTO_UNSPEC].target : &xt[NFPROTO_UNSPEC].match;
1047                break;
1048        case MTTG_TRAV_NFP_UNSPEC:
1049                trav->curr = trav->curr->next;
1050                if (trav->curr != trav->head)
1051                        break;
1052                mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
1053                mutex_lock(&xt[trav->nfproto].mutex);
1054                trav->head = trav->curr = is_target ?
1055                        &xt[trav->nfproto].target : &xt[trav->nfproto].match;
1056                trav->class = next_class[trav->class];
1057                break;
1058        case MTTG_TRAV_NFP_SPEC:
1059                trav->curr = trav->curr->next;
1060                if (trav->curr != trav->head)
1061                        break;
1062                /* fallthru, _stop will unlock */
1063        default:
1064                return NULL;
1065        }
1066
1067        if (ppos != NULL)
1068                ++*ppos;
1069        return trav;
1070}
1071
1072static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
1073    bool is_target)
1074{
1075        struct nf_mttg_trav *trav = seq->private;
1076        unsigned int j;
1077
1078        trav->class = MTTG_TRAV_INIT;
1079        for (j = 0; j < *pos; ++j)
1080                if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
1081                        return NULL;
1082        return trav;
1083}
1084
1085static void xt_mttg_seq_stop(struct seq_file *seq, void *v)
1086{
1087        struct nf_mttg_trav *trav = seq->private;
1088
1089        switch (trav->class) {
1090        case MTTG_TRAV_NFP_UNSPEC:
1091                mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
1092                break;
1093        case MTTG_TRAV_NFP_SPEC:
1094                mutex_unlock(&xt[trav->nfproto].mutex);
1095                break;
1096        }
1097}
1098
1099static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
1100{
1101        return xt_mttg_seq_start(seq, pos, false);
1102}
1103
1104static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
1105{
1106        return xt_mttg_seq_next(seq, v, ppos, false);
1107}
1108
1109static int xt_match_seq_show(struct seq_file *seq, void *v)
1110{
1111        const struct nf_mttg_trav *trav = seq->private;
1112        const struct xt_match *match;
1113
1114        switch (trav->class) {
1115        case MTTG_TRAV_NFP_UNSPEC:
1116        case MTTG_TRAV_NFP_SPEC:
1117                if (trav->curr == trav->head)
1118                        return 0;
1119                match = list_entry(trav->curr, struct xt_match, list);
1120                return (*match->name == '\0') ? 0 :
1121                       seq_printf(seq, "%s\n", match->name);
1122        }
1123        return 0;
1124}
1125
1126static const struct seq_operations xt_match_seq_ops = {
1127        .start  = xt_match_seq_start,
1128        .next   = xt_match_seq_next,
1129        .stop   = xt_mttg_seq_stop,
1130        .show   = xt_match_seq_show,
1131};
1132
1133static int xt_match_open(struct inode *inode, struct file *file)
1134{
1135        struct seq_file *seq;
1136        struct nf_mttg_trav *trav;
1137        int ret;
1138
1139        trav = kmalloc(sizeof(*trav), GFP_KERNEL);
1140        if (trav == NULL)
1141                return -ENOMEM;
1142
1143        ret = seq_open(file, &xt_match_seq_ops);
1144        if (ret < 0) {
1145                kfree(trav);
1146                return ret;
1147        }
1148
1149        seq = file->private_data;
1150        seq->private = trav;
1151        trav->nfproto = (unsigned long)PDE_DATA(inode);
1152        return 0;
1153}
1154
1155static const struct file_operations xt_match_ops = {
1156        .owner   = THIS_MODULE,
1157        .open    = xt_match_open,
1158        .read    = seq_read,
1159        .llseek  = seq_lseek,
1160        .release = seq_release_private,
1161};
1162
1163static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos)
1164{
1165        return xt_mttg_seq_start(seq, pos, true);
1166}
1167
1168static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
1169{
1170        return xt_mttg_seq_next(seq, v, ppos, true);
1171}
1172
1173static int xt_target_seq_show(struct seq_file *seq, void *v)
1174{
1175        const struct nf_mttg_trav *trav = seq->private;
1176        const struct xt_target *target;
1177
1178        switch (trav->class) {
1179        case MTTG_TRAV_NFP_UNSPEC:
1180        case MTTG_TRAV_NFP_SPEC:
1181                if (trav->curr == trav->head)
1182                        return 0;
1183                target = list_entry(trav->curr, struct xt_target, list);
1184                return (*target->name == '\0') ? 0 :
1185                       seq_printf(seq, "%s\n", target->name);
1186        }
1187        return 0;
1188}
1189
1190static const struct seq_operations xt_target_seq_ops = {
1191        .start  = xt_target_seq_start,
1192        .next   = xt_target_seq_next,
1193        .stop   = xt_mttg_seq_stop,
1194        .show   = xt_target_seq_show,
1195};
1196
1197static int xt_target_open(struct inode *inode, struct file *file)
1198{
1199        struct seq_file *seq;
1200        struct nf_mttg_trav *trav;
1201        int ret;
1202
1203        trav = kmalloc(sizeof(*trav), GFP_KERNEL);
1204        if (trav == NULL)
1205                return -ENOMEM;
1206
1207        ret = seq_open(file, &xt_target_seq_ops);
1208        if (ret < 0) {
1209                kfree(trav);
1210                return ret;
1211        }
1212
1213        seq = file->private_data;
1214        seq->private = trav;
1215        trav->nfproto = (unsigned long)PDE_DATA(inode);
1216        return 0;
1217}
1218
1219static const struct file_operations xt_target_ops = {
1220        .owner   = THIS_MODULE,
1221        .open    = xt_target_open,
1222        .read    = seq_read,
1223        .llseek  = seq_lseek,
1224        .release = seq_release_private,
1225};
1226
1227#define FORMAT_TABLES   "_tables_names"
1228#define FORMAT_MATCHES  "_tables_matches"
1229#define FORMAT_TARGETS  "_tables_targets"
1230
1231#endif /* CONFIG_PROC_FS */
1232
1233/**
1234 * xt_hook_link - set up hooks for a new table
1235 * @table:      table with metadata needed to set up hooks
1236 * @fn:         Hook function
1237 *
1238 * This function will take care of creating and registering the necessary
1239 * Netfilter hooks for XT tables.
1240 */
1241struct nf_hook_ops *xt_hook_link(const struct xt_table *table, nf_hookfn *fn)
1242{
1243        unsigned int hook_mask = table->valid_hooks;
1244        uint8_t i, num_hooks = hweight32(hook_mask);
1245        uint8_t hooknum;
1246        struct nf_hook_ops *ops;
1247        int ret;
1248
1249        ops = kmalloc(sizeof(*ops) * num_hooks, GFP_KERNEL);
1250        if (ops == NULL)
1251                return ERR_PTR(-ENOMEM);
1252
1253        for (i = 0, hooknum = 0; i < num_hooks && hook_mask != 0;
1254             hook_mask >>= 1, ++hooknum) {
1255                if (!(hook_mask & 1))
1256                        continue;
1257                ops[i].hook     = fn;
1258                ops[i].owner    = table->me;
1259                ops[i].pf       = table->af;
1260                ops[i].hooknum  = hooknum;
1261                ops[i].priority = table->priority;
1262                ++i;
1263        }
1264
1265        ret = nf_register_hooks(ops, num_hooks);
1266        if (ret < 0) {
1267                kfree(ops);
1268                return ERR_PTR(ret);
1269        }
1270
1271        return ops;
1272}
1273EXPORT_SYMBOL_GPL(xt_hook_link);
1274
1275/**
1276 * xt_hook_unlink - remove hooks for a table
1277 * @ops:        nf_hook_ops array as returned by nf_hook_link
1278 * @hook_mask:  the very same mask that was passed to nf_hook_link
1279 */
1280void xt_hook_unlink(const struct xt_table *table, struct nf_hook_ops *ops)
1281{
1282        nf_unregister_hooks(ops, hweight32(table->valid_hooks));
1283        kfree(ops);
1284}
1285EXPORT_SYMBOL_GPL(xt_hook_unlink);
1286
1287int xt_proto_init(struct net *net, u_int8_t af)
1288{
1289#ifdef CONFIG_PROC_FS
1290        char buf[XT_FUNCTION_MAXNAMELEN];
1291        struct proc_dir_entry *proc;
1292#endif
1293
1294        if (af >= ARRAY_SIZE(xt_prefix))
1295                return -EINVAL;
1296
1297
1298#ifdef CONFIG_PROC_FS
1299        strlcpy(buf, xt_prefix[af], sizeof(buf));
1300        strlcat(buf, FORMAT_TABLES, sizeof(buf));
1301        proc = proc_create_data(buf, 0440, net->proc_net, &xt_table_ops,
1302                                (void *)(unsigned long)af);
1303        if (!proc)
1304                goto out;
1305
1306        strlcpy(buf, xt_prefix[af], sizeof(buf));
1307        strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1308        proc = proc_create_data(buf, 0440, net->proc_net, &xt_match_ops,
1309                                (void *)(unsigned long)af);
1310        if (!proc)
1311                goto out_remove_tables;
1312
1313        strlcpy(buf, xt_prefix[af], sizeof(buf));
1314        strlcat(buf, FORMAT_TARGETS, sizeof(buf));
1315        proc = proc_create_data(buf, 0440, net->proc_net, &xt_target_ops,
1316                                (void *)(unsigned long)af);
1317        if (!proc)
1318                goto out_remove_matches;
1319#endif
1320
1321        return 0;
1322
1323#ifdef CONFIG_PROC_FS
1324out_remove_matches:
1325        strlcpy(buf, xt_prefix[af], sizeof(buf));
1326        strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1327        remove_proc_entry(buf, net->proc_net);
1328
1329out_remove_tables:
1330        strlcpy(buf, xt_prefix[af], sizeof(buf));
1331        strlcat(buf, FORMAT_TABLES, sizeof(buf));
1332        remove_proc_entry(buf, net->proc_net);
1333out:
1334        return -1;
1335#endif
1336}
1337EXPORT_SYMBOL_GPL(xt_proto_init);
1338
1339void xt_proto_fini(struct net *net, u_int8_t af)
1340{
1341#ifdef CONFIG_PROC_FS
1342        char buf[XT_FUNCTION_MAXNAMELEN];
1343
1344        strlcpy(buf, xt_prefix[af], sizeof(buf));
1345        strlcat(buf, FORMAT_TABLES, sizeof(buf));
1346        remove_proc_entry(buf, net->proc_net);
1347
1348        strlcpy(buf, xt_prefix[af], sizeof(buf));
1349        strlcat(buf, FORMAT_TARGETS, sizeof(buf));
1350        remove_proc_entry(buf, net->proc_net);
1351
1352        strlcpy(buf, xt_prefix[af], sizeof(buf));
1353        strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1354        remove_proc_entry(buf, net->proc_net);
1355#endif /*CONFIG_PROC_FS*/
1356}
1357EXPORT_SYMBOL_GPL(xt_proto_fini);
1358
1359static int __net_init xt_net_init(struct net *net)
1360{
1361        int i;
1362
1363        for (i = 0; i < NFPROTO_NUMPROTO; i++)
1364                INIT_LIST_HEAD(&net->xt.tables[i]);
1365        return 0;
1366}
1367
1368static struct pernet_operations xt_net_ops = {
1369        .init = xt_net_init,
1370};
1371
1372static int __init xt_init(void)
1373{
1374        unsigned int i;
1375        int rv;
1376
1377        for_each_possible_cpu(i) {
1378                seqcount_init(&per_cpu(xt_recseq, i));
1379        }
1380
1381        xt = kmalloc(sizeof(struct xt_af) * NFPROTO_NUMPROTO, GFP_KERNEL);
1382        if (!xt)
1383                return -ENOMEM;
1384
1385        for (i = 0; i < NFPROTO_NUMPROTO; i++) {
1386                mutex_init(&xt[i].mutex);
1387#ifdef CONFIG_COMPAT
1388                mutex_init(&xt[i].compat_mutex);
1389                xt[i].compat_tab = NULL;
1390#endif
1391                INIT_LIST_HEAD(&xt[i].target);
1392                INIT_LIST_HEAD(&xt[i].match);
1393        }
1394        rv = register_pernet_subsys(&xt_net_ops);
1395        if (rv < 0)
1396                kfree(xt);
1397        return rv;
1398}
1399
1400static void __exit xt_fini(void)
1401{
1402        unregister_pernet_subsys(&xt_net_ops);
1403        kfree(xt);
1404}
1405
1406module_init(xt_init);
1407module_exit(xt_fini);
1408
1409
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