net/core/netfilter.c

   1 /* netfilter.c: look after the filters for various protocols.
   2  * Heavily influenced by the old firewall.c by David Bonn and Alan Cox.
   3  *
   4  * Thanks to Rob `CmdrTaco' Malda for not influencing this code in any
   5  * way.
   6  *
   7  * Rusty Russell (C)2000 -- This code is GPL.
   8  *
   9  * February 2000: Modified by James Morris to have 1 queue per protocol.
  10  * 15-Mar-2000:   Added NF_REPEAT --RR.
  11  * 08-May-2003:   Internal logging interface added by Jozsef Kadlecsik.
  12  */
  13 #include <linux/config.h>
  14 #include <linux/kernel.h>
  15 #include <linux/netfilter.h>
  16 #include <net/protocol.h>
  17 #include <linux/init.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/wait.h>
  20 #include <linux/module.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/if.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/inetdevice.h>
  25 #include <linux/proc_fs.h>
  26 #include <net/sock.h>
  27
  28 /* In this code, we can be waiting indefinitely for userspace to
  29  * service a packet if a hook returns NF_QUEUE.  We could keep a count
  30  * of skbuffs queued for userspace, and not deregister a hook unless
  31  * this is zero, but that sucks.  Now, we simply check when the
  32  * packets come back: if the hook is gone, the packet is discarded. */
  33 #ifdef CONFIG_NETFILTER_DEBUG
  34 #define NFDEBUG(format, args...)  printk(format , ## args)
  35 #else
  36 #define NFDEBUG(format, args...)
  37 #endif
  38
  39 /* Sockopts only registered and called from user context, so
  40    net locking would be overkill.  Also, [gs]etsockopt calls may
  41    sleep. */
  42 static DECLARE_MUTEX(nf_sockopt_mutex);
  43
  44 struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS];
  45 static LIST_HEAD(nf_sockopts);
  46 static DEFINE_SPINLOCK(nf_hook_lock);
  47
  48 /*
  49  * A queue handler may be registered for each protocol.  Each is protected by
  50  * long term mutex.  The handler must provide an an outfn() to accept packets
  51  * for queueing and must reinject all packets it receives, no matter what.
  52  */
  53 static struct nf_queue_handler_t {
  54         nf_queue_outfn_t outfn;
  55         void *data;
  56 } queue_handler[NPROTO];
  57
  58 static struct nf_queue_rerouter *queue_rerouter;
  59
  60 static DEFINE_RWLOCK(queue_handler_lock);
  61
  62 int nf_register_hook(struct nf_hook_ops *reg)
  63 {
  64         struct list_head *i;
  65
  66         spin_lock_bh(&nf_hook_lock);
  67         list_for_each(i, &nf_hooks[reg->pf][reg->hooknum]) {
  68                 if (reg->priority < ((struct nf_hook_ops *)i)->priority)
  69                         break;
  70         }
  71         list_add_rcu(&reg->list, i->prev);
  72         spin_unlock_bh(&nf_hook_lock);
  73
  74         synchronize_net();
  75         return 0;
  76 }
  77
  78 void nf_unregister_hook(struct nf_hook_ops *reg)
  79 {
  80         spin_lock_bh(&nf_hook_lock);
  81         list_del_rcu(&reg->list);
  82         spin_unlock_bh(&nf_hook_lock);
  83
  84         synchronize_net();
  85 }
  86
  87 /* Do exclusive ranges overlap? */
  88 static inline int overlap(int min1, int max1, int min2, int max2)
  89 {
  90         return max1 > min2 && min1 < max2;
  91 }
  92
  93 /* Functions to register sockopt ranges (exclusive). */
  94 int nf_register_sockopt(struct nf_sockopt_ops *reg)
  95 {
  96         struct list_head *i;
  97         int ret = 0;
  98
  99         if (down_interruptible(&nf_sockopt_mutex) != 0)
 100                 return -EINTR;
 101
 102         list_for_each(i, &nf_sockopts) {
 103                 struct nf_sockopt_ops *ops = (struct nf_sockopt_ops *)i;
 104                 if (ops->pf == reg->pf
 105                     && (overlap(ops->set_optmin, ops->set_optmax,
 106                                 reg->set_optmin, reg->set_optmax)
 107                         || overlap(ops->get_optmin, ops->get_optmax,
 108                                    reg->get_optmin, reg->get_optmax))) {
 109                         NFDEBUG("nf_sock overlap: %u-%u/%u-%u v %u-%u/%u-%u\n",
 110                                 ops->set_optmin, ops->set_optmax,
 111                                 ops->get_optmin, ops->get_optmax,
 112                                 reg->set_optmin, reg->set_optmax,
 113                                 reg->get_optmin, reg->get_optmax);
 114                         ret = -EBUSY;
 115                         goto out;
 116                 }
 117         }
 118
 119         list_add(&reg->list, &nf_sockopts);
 120 out:
 121         up(&nf_sockopt_mutex);
 122         return ret;
 123 }
 124
 125 void nf_unregister_sockopt(struct nf_sockopt_ops *reg)
 126 {
 127         /* No point being interruptible: we're probably in cleanup_module() */
 128  restart:
 129         down(&nf_sockopt_mutex);
 130         if (reg->use != 0) {
 131                 /* To be woken by nf_sockopt call... */
 132                 /* FIXME: Stuart Young's name appears gratuitously. */
 133                 set_current_state(TASK_UNINTERRUPTIBLE);
 134                 reg->cleanup_task = current;
 135                 up(&nf_sockopt_mutex);
 136                 schedule();
 137                 goto restart;
 138         }
 139         list_del(&reg->list);
 140         up(&nf_sockopt_mutex);
 141 }
 142
 143 /* Call get/setsockopt() */
 144 static int nf_sockopt(struct sock *sk, int pf, int val,
 145                       char __user *opt, int *len, int get)
 146 {
 147         struct list_head *i;
 148         struct nf_sockopt_ops *ops;
 149         int ret;
 150
 151         if (down_interruptible(&nf_sockopt_mutex) != 0)
 152                 return -EINTR;
 153
 154         list_for_each(i, &nf_sockopts) {
 155                 ops = (struct nf_sockopt_ops *)i;
 156                 if (ops->pf == pf) {
 157                         if (get) {
 158                                 if (val >= ops->get_optmin
 159                                     && val < ops->get_optmax) {
 160                                         ops->use++;
 161                                         up(&nf_sockopt_mutex);
 162                                         ret = ops->get(sk, val, opt, len);
 163                                         goto out;
 164                                 }
 165                         } else {
 166                                 if (val >= ops->set_optmin
 167                                     && val < ops->set_optmax) {
 168                                         ops->use++;
 169                                         up(&nf_sockopt_mutex);
 170                                         ret = ops->set(sk, val, opt, *len);
 171                                         goto out;
 172                                 }
 173                         }
 174                 }
 175         }
 176         up(&nf_sockopt_mutex);
 177         return -ENOPROTOOPT;
 178
 179  out:
 180         down(&nf_sockopt_mutex);
 181         ops->use--;
 182         if (ops->cleanup_task)
 183                 wake_up_process(ops->cleanup_task);
 184         up(&nf_sockopt_mutex);
 185         return ret;
 186 }
 187
 188 int nf_setsockopt(struct sock *sk, int pf, int val, char __user *opt,
 189                   int len)
 190 {
 191         return nf_sockopt(sk, pf, val, opt, &len, 0);
 192 }
 193
 194 int nf_getsockopt(struct sock *sk, int pf, int val, char __user *opt, int *len)
 195 {
 196         return nf_sockopt(sk, pf, val, opt, len, 1);
 197 }
 198
 199 static unsigned int nf_iterate(struct list_head *head,
 200                                struct sk_buff **skb,
 201                                int hook,
 202                                const struct net_device *indev,
 203                                const struct net_device *outdev,
 204                                struct list_head **i,
 205                                int (*okfn)(struct sk_buff *),
 206                                int hook_thresh)
 207 {
 208         unsigned int verdict;
 209
 210         /*
 211          * The caller must not block between calls to this
 212          * function because of risk of continuing from deleted element.
 213          */
 214         list_for_each_continue_rcu(*i, head) {
 215                 struct nf_hook_ops *elem = (struct nf_hook_ops *)*i;
 216
 217                 if (hook_thresh > elem->priority)
 218                         continue;
 219
 220                 /* Optimization: we don't need to hold module
 221                    reference here, since function can't sleep. --RR */
 222                 verdict = elem->hook(hook, skb, indev, outdev, okfn);
 223                 if (verdict != NF_ACCEPT) {
 224 #ifdef CONFIG_NETFILTER_DEBUG
 225                         if (unlikely((verdict & NF_VERDICT_MASK)
 226                                                         > NF_MAX_VERDICT)) {
 227                                 NFDEBUG("Evil return from %p(%u).\n",
 228                                         elem->hook, hook);
 229                                 continue;
 230                         }
 231 #endif
 232                         if (verdict != NF_REPEAT)
 233                                 return verdict;
 234                         *i = (*i)->prev;
 235                 }
 236         }
 237         return NF_ACCEPT;
 238 }
 239
 240 int nf_register_queue_handler(int pf, nf_queue_outfn_t outfn, void *data)
 241 {
 242         int ret;
 243
 244         if (pf >= NPROTO)
 245                 return -EINVAL;
 246
 247         write_lock_bh(&queue_handler_lock);
 248         if (queue_handler[pf].outfn)
 249                 ret = -EBUSY;
 250         else {
 251                 queue_handler[pf].outfn = outfn;
 252                 queue_handler[pf].data = data;
 253                 ret = 0;
 254         }
 255         write_unlock_bh(&queue_handler_lock);
 256
 257         return ret;
 258 }
 259
 260 /* The caller must flush their queue before this */
 261 int nf_unregister_queue_handler(int pf)
 262 {
 263         if (pf >= NPROTO)
 264                 return -EINVAL;
 265
 266         write_lock_bh(&queue_handler_lock);
 267         queue_handler[pf].outfn = NULL;
 268         queue_handler[pf].data = NULL;
 269         write_unlock_bh(&queue_handler_lock);
 270
 271         return 0;
 272 }
 273
 274 int nf_register_queue_rerouter(int pf, struct nf_queue_rerouter *rer)
 275 {
 276         if (pf >= NPROTO)
 277                 return -EINVAL;
 278
 279         write_lock_bh(&queue_handler_lock);
 280         memcpy(&queue_rerouter[pf], rer, sizeof(queue_rerouter[pf]));
 281         write_unlock_bh(&queue_handler_lock);
 282
 283         return 0;
 284 }
 285
 286 int nf_unregister_queue_rerouter(int pf)
 287 {
 288         if (pf >= NPROTO)
 289                 return -EINVAL;
 290
 291         write_lock_bh(&queue_handler_lock);
 292         memset(&queue_rerouter[pf], 0, sizeof(queue_rerouter[pf]));
 293         write_unlock_bh(&queue_handler_lock);
 294         return 0;
 295 }
 296
 297 void nf_unregister_queue_handlers(nf_queue_outfn_t outfn)
 298 {
 299         int pf;
 300
 301         write_lock_bh(&queue_handler_lock);
 302         for (pf = 0; pf < NPROTO; pf++)  {
 303                 if (queue_handler[pf].outfn == outfn) {
 304                         queue_handler[pf].outfn = NULL;
 305                         queue_handler[pf].data = NULL;
 306                 }
 307         }
 308         write_unlock_bh(&queue_handler_lock);
 309 }
 310
 311 /*
 312  * Any packet that leaves via this function must come back
 313  * through nf_reinject().
 314  */
 315 static int nf_queue(struct sk_buff **skb,
 316                     struct list_head *elem,
 317                     int pf, unsigned int hook,
 318                     struct net_device *indev,
 319                     struct net_device *outdev,
 320                     int (*okfn)(struct sk_buff *),
 321                     unsigned int queuenum)
 322 {
 323         int status;
 324         struct nf_info *info;
 325 #ifdef CONFIG_BRIDGE_NETFILTER
 326         struct net_device *physindev = NULL;
 327         struct net_device *physoutdev = NULL;
 328 #endif
 329
 330         /* QUEUE == DROP if noone is waiting, to be safe. */
 331         read_lock(&queue_handler_lock);
 332         if (!queue_handler[pf].outfn) {
 333                 read_unlock(&queue_handler_lock);
 334                 kfree_skb(*skb);
 335                 return 1;
 336         }
 337
 338         info = kmalloc(sizeof(*info)+queue_rerouter[pf].rer_size, GFP_ATOMIC);
 339         if (!info) {
 340                 if (net_ratelimit())
 341                         printk(KERN_ERR "OOM queueing packet %p\n",
 342                                *skb);
 343                 read_unlock(&queue_handler_lock);
 344                 kfree_skb(*skb);
 345                 return 1;
 346         }
 347
 348         *info = (struct nf_info) {
 349                 (struct nf_hook_ops *)elem, pf, hook, indev, outdev, okfn };
 350
 351         /* If it's going away, ignore hook. */
 352         if (!try_module_get(info->elem->owner)) {
 353                 read_unlock(&queue_handler_lock);
 354                 kfree(info);
 355                 return 0;
 356         }
 357
 358         /* Bump dev refs so they don't vanish while packet is out */
 359         if (indev) dev_hold(indev);
 360         if (outdev) dev_hold(outdev);
 361
 362 #ifdef CONFIG_BRIDGE_NETFILTER
 363         if ((*skb)->nf_bridge) {
 364                 physindev = (*skb)->nf_bridge->physindev;
 365                 if (physindev) dev_hold(physindev);
 366                 physoutdev = (*skb)->nf_bridge->physoutdev;
 367                 if (physoutdev) dev_hold(physoutdev);
 368         }
 369 #endif
 370         if (queue_rerouter[pf].save)
 371                 queue_rerouter[pf].save(*skb, info);
 372
 373         status = queue_handler[pf].outfn(*skb, info, queuenum,
 374                                          queue_handler[pf].data);
 375
 376         if (status >= 0 && queue_rerouter[pf].reroute)
 377                 status = queue_rerouter[pf].reroute(skb, info);
 378
 379         read_unlock(&queue_handler_lock);
 380
 381         if (status < 0) {
 382                 /* James M doesn't say fuck enough. */
 383                 if (indev) dev_put(indev);
 384                 if (outdev) dev_put(outdev);
 385 #ifdef CONFIG_BRIDGE_NETFILTER
 386                 if (physindev) dev_put(physindev);
 387                 if (physoutdev) dev_put(physoutdev);
 388 #endif
 389                 module_put(info->elem->owner);
 390                 kfree(info);
 391                 kfree_skb(*skb);
 392
 393                 return 1;
 394         }
 395
 396         return 1;
 397 }
 398
 399 /* Returns 1 if okfn() needs to be executed by the caller,
 400  * -EPERM for NF_DROP, 0 otherwise. */
 401 int nf_hook_slow(int pf, unsigned int hook, struct sk_buff **pskb,
 402                  struct net_device *indev,
 403                  struct net_device *outdev,
 404                  int (*okfn)(struct sk_buff *),
 405                  int hook_thresh)
 406 {
 407         struct list_head *elem;
 408         unsigned int verdict;
 409         int ret = 0;
 410
 411         /* We may already have this, but read-locks nest anyway */
 412         rcu_read_lock();
 413
 414         elem = &nf_hooks[pf][hook];
 415 next_hook:
 416         verdict = nf_iterate(&nf_hooks[pf][hook], pskb, hook, indev,
 417                              outdev, &elem, okfn, hook_thresh);
 418         if (verdict == NF_ACCEPT || verdict == NF_STOP) {
 419                 ret = 1;
 420                 goto unlock;
 421         } else if (verdict == NF_DROP) {
 422                 kfree_skb(*pskb);
 423                 ret = -EPERM;
 424         } else if ((verdict & NF_VERDICT_MASK)  == NF_QUEUE) {
 425                 NFDEBUG("nf_hook: Verdict = QUEUE.\n");
 426                 if (!nf_queue(pskb, elem, pf, hook, indev, outdev, okfn,
 427                               verdict >> NF_VERDICT_BITS))
 428                         goto next_hook;
 429         }
 430 unlock:
 431         rcu_read_unlock();
 432         return ret;
 433 }
 434
 435 void nf_reinject(struct sk_buff *skb, struct nf_info *info,
 436                  unsigned int verdict)
 437 {
 438         struct list_head *elem = &info->elem->list;
 439         struct list_head *i;
 440
 441         rcu_read_lock();
 442
 443         /* Release those devices we held, or Alexey will kill me. */
 444         if (info->indev) dev_put(info->indev);
 445         if (info->outdev) dev_put(info->outdev);
 446 #ifdef CONFIG_BRIDGE_NETFILTER
 447         if (skb->nf_bridge) {
 448                 if (skb->nf_bridge->physindev)
 449                         dev_put(skb->nf_bridge->physindev);
 450                 if (skb->nf_bridge->physoutdev)
 451                         dev_put(skb->nf_bridge->physoutdev);
 452         }
 453 #endif
 454
 455         /* Drop reference to owner of hook which queued us. */
 456         module_put(info->elem->owner);
 457
 458         list_for_each_rcu(i, &nf_hooks[info->pf][info->hook]) {
 459                 if (i == elem)
 460                         break;
 461         }
 462
 463         if (elem == &nf_hooks[info->pf][info->hook]) {
 464                 /* The module which sent it to userspace is gone. */
 465                 NFDEBUG("%s: module disappeared, dropping packet.\n",
 466                         __FUNCTION__);
 467                 verdict = NF_DROP;
 468         }
 469
 470         /* Continue traversal iff userspace said ok... */
 471         if (verdict == NF_REPEAT) {
 472                 elem = elem->prev;
 473                 verdict = NF_ACCEPT;
 474         }
 475
 476         if (verdict == NF_ACCEPT) {
 477         next_hook:
 478                 verdict = nf_iterate(&nf_hooks[info->pf][info->hook],
 479                                      &skb, info->hook,
 480                                      info->indev, info->outdev, &elem,
 481                                      info->okfn, INT_MIN);
 482         }
 483
 484         switch (verdict & NF_VERDICT_MASK) {
 485         case NF_ACCEPT:
 486                 info->okfn(skb);
 487                 break;
 488
 489         case NF_QUEUE:
 490                 if (!nf_queue(&skb, elem, info->pf, info->hook,
 491                               info->indev, info->outdev, info->okfn,
 492                               verdict >> NF_VERDICT_BITS))
 493                         goto next_hook;
 494                 break;
 495         }
 496         rcu_read_unlock();
 497
 498         if (verdict == NF_DROP)
 499                 kfree_skb(skb);
 500
 501         kfree(info);
 502         return;
 503 }
 504
 505 int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len)
 506 {
 507         struct sk_buff *nskb;
 508
 509         if (writable_len > (*pskb)->len)
 510                 return 0;
 511
 512         /* Not exclusive use of packet?  Must copy. */
 513         if (skb_shared(*pskb) || skb_cloned(*pskb))
 514                 goto copy_skb;
 515
 516         return pskb_may_pull(*pskb, writable_len);
 517
 518 copy_skb:
 519         nskb = skb_copy(*pskb, GFP_ATOMIC);
 520         if (!nskb)
 521                 return 0;
 522         BUG_ON(skb_is_nonlinear(nskb));
 523
 524         /* Rest of kernel will get very unhappy if we pass it a
 525            suddenly-orphaned skbuff */
 526         if ((*pskb)->sk)
 527                 skb_set_owner_w(nskb, (*pskb)->sk);
 528         kfree_skb(*pskb);
 529         *pskb = nskb;
 530         return 1;
 531 }
 532 EXPORT_SYMBOL(skb_make_writable);
 533
 534 /* Internal logging interface, which relies on the real
 535    LOG target modules */
 536
 537 #define NF_LOG_PREFIXLEN                128
 538
 539 static struct nf_logger *nf_logging[NPROTO]; /* = NULL */
 540 static DEFINE_SPINLOCK(nf_log_lock);
 541
 542 int nf_log_register(int pf, struct nf_logger *logger)
 543 {
 544         int ret = -EBUSY;
 545
 546         /* Any setup of logging members must be done before
 547          * substituting pointer. */
 548         spin_lock(&nf_log_lock);
 549         if (!nf_logging[pf]) {
 550                 rcu_assign_pointer(nf_logging[pf], logger);
 551                 ret = 0;
 552         }
 553         spin_unlock(&nf_log_lock);
 554         return ret;
 555 }
 556
 557 void nf_log_unregister_pf(int pf)
 558 {
 559         spin_lock(&nf_log_lock);
 560         nf_logging[pf] = NULL;
 561         spin_unlock(&nf_log_lock);
 562
 563         /* Give time to concurrent readers. */
 564         synchronize_net();
 565 }
 566
 567 void nf_log_unregister_logger(struct nf_logger *logger)
 568 {
 569         int i;
 570
 571         spin_lock(&nf_log_lock);
 572         for (i = 0; i < NPROTO; i++) {
 573                 if (nf_logging[i] == logger)
 574                         nf_logging[i] = NULL;
 575         }
 576         spin_unlock(&nf_log_lock);
 577
 578         synchronize_net();
 579 }
 580
 581 void nf_log_packet(int pf,
 582                    unsigned int hooknum,
 583                    const struct sk_buff *skb,
 584                    const struct net_device *in,
 585                    const struct net_device *out,
 586                    struct nf_loginfo *loginfo,
 587                    const char *fmt, ...)
 588 {
 589         va_list args;
 590         char prefix[NF_LOG_PREFIXLEN];
 591         struct nf_logger *logger;
 592
 593         rcu_read_lock();
 594         logger = rcu_dereference(nf_logging[pf]);
 595         if (logger) {
 596                 va_start(args, fmt);
 597                 vsnprintf(prefix, sizeof(prefix), fmt, args);
 598                 va_end(args);
 599                 /* We must read logging before nf_logfn[pf] */
 600                 logger->logfn(pf, hooknum, skb, in, out, loginfo, prefix);
 601         } else if (net_ratelimit()) {
 602                 printk(KERN_WARNING "nf_log_packet: can\'t log since "
 603                        "no backend logging module loaded in! Please either "
 604                        "load one, or disable logging explicitly\n");
 605         }
 606         rcu_read_unlock();
 607 }
 608 EXPORT_SYMBOL(nf_log_register);
 609 EXPORT_SYMBOL(nf_log_unregister_pf);
 610 EXPORT_SYMBOL(nf_log_unregister_logger);
 611 EXPORT_SYMBOL(nf_log_packet);
 612
 613 #ifdef CONFIG_PROC_FS
 614 struct proc_dir_entry *proc_net_netfilter;
 615 EXPORT_SYMBOL(proc_net_netfilter);
 616
 617 static void *seq_start(struct seq_file *seq, loff_t *pos)
 618 {
 619         rcu_read_lock();
 620
 621         if (*pos >= NPROTO)
 622                 return NULL;
 623
 624         return pos;
 625 }
 626
 627 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
 628 {
 629         (*pos)++;
 630
 631         if (*pos >= NPROTO)
 632                 return NULL;
 633
 634         return pos;
 635 }
 636
 637 static void seq_stop(struct seq_file *s, void *v)
 638 {
 639         rcu_read_unlock();
 640 }
 641
 642 static int seq_show(struct seq_file *s, void *v)
 643 {
 644         loff_t *pos = v;
 645         const struct nf_logger *logger;
 646
 647         logger = rcu_dereference(nf_logging[*pos]);
 648
 649         if (!logger)
 650                 return seq_printf(s, "%2lld NONE\n", *pos);
 651
 652         return seq_printf(s, "%2lld %s\n", *pos, logger->name);
 653 }
 654
 655 static struct seq_operations nflog_seq_ops = {
 656         .start  = seq_start,
 657         .next   = seq_next,
 658         .stop   = seq_stop,
 659         .show   = seq_show,
 660 };
 661
 662 static int nflog_open(struct inode *inode, struct file *file)
 663 {
 664         return seq_open(file, &nflog_seq_ops);
 665 }
 666
 667 static struct file_operations nflog_file_ops = {
 668         .owner   = THIS_MODULE,
 669         .open    = nflog_open,
 670         .read    = seq_read,
 671         .llseek  = seq_lseek,
 672         .release = seq_release,
 673 };
 674
 675 #endif /* PROC_FS */
 676
 677
 678 /* This does not belong here, but locally generated errors need it if connection
 679    tracking in use: without this, connection may not be in hash table, and hence
 680    manufactured ICMP or RST packets will not be associated with it. */
 681 void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *);
 682
 683 void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb)
 684 {
 685         void (*attach)(struct sk_buff *, struct sk_buff *);
 686
 687         if (skb->nfct && (attach = ip_ct_attach) != NULL) {
 688                 mb(); /* Just to be sure: must be read before executing this */
 689                 attach(new, skb);
 690         }
 691 }
 692
 693 void __init netfilter_init(void)
 694 {
 695         int i, h;
 696 #ifdef CONFIG_PROC_FS
 697         struct proc_dir_entry *pde;
 698 #endif
 699
 700         queue_rerouter = kmalloc(NPROTO * sizeof(struct nf_queue_rerouter),
 701                                  GFP_KERNEL);
 702         if (!queue_rerouter)
 703                 panic("netfilter: cannot allocate queue rerouter array\n");
 704         memset(queue_rerouter, 0, NPROTO * sizeof(struct nf_queue_rerouter));
 705
 706         for (i = 0; i < NPROTO; i++) {
 707                 for (h = 0; h < NF_MAX_HOOKS; h++)
 708                         INIT_LIST_HEAD(&nf_hooks[i][h]);
 709         }
 710
 711 #ifdef CONFIG_PROC_FS
 712         proc_net_netfilter = proc_mkdir("netfilter", proc_net);
 713         if (!proc_net_netfilter)
 714                 panic("cannot create netfilter proc entry");
 715         pde = create_proc_entry("nf_log", S_IRUGO, proc_net_netfilter);
 716         if (!pde)
 717                 panic("cannot create /proc/net/netfilter/nf_log");
 718         pde->proc_fops = &nflog_file_ops;
 719 #endif
 720 }
 721
 722 EXPORT_SYMBOL(ip_ct_attach);
 723 EXPORT_SYMBOL(nf_ct_attach);
 724 EXPORT_SYMBOL(nf_getsockopt);
 725 EXPORT_SYMBOL(nf_hook_slow);
 726 EXPORT_SYMBOL(nf_hooks);
 727 EXPORT_SYMBOL(nf_register_hook);
 728 EXPORT_SYMBOL(nf_register_queue_handler);
 729 EXPORT_SYMBOL(nf_register_sockopt);
 730 EXPORT_SYMBOL(nf_reinject);
 731 EXPORT_SYMBOL(nf_setsockopt);
 732 EXPORT_SYMBOL(nf_unregister_hook);
 733 EXPORT_SYMBOL(nf_unregister_queue_handler);
 734 EXPORT_SYMBOL_GPL(nf_unregister_queue_handlers);
 735 EXPORT_SYMBOL_GPL(nf_register_queue_rerouter);
 736 EXPORT_SYMBOL_GPL(nf_unregister_queue_rerouter);
 737 EXPORT_SYMBOL(nf_unregister_sockopt);