SAFE public projects git trees. - safe/jmp/linux-2.6/blob - net/netfilter/nfnetlink_queue.c

   1 /*
   2  * This is a module which is used for queueing packets and communicating with
   3  * userspace via nfetlink.
   4  *
   5  * (C) 2005 by Harald Welte <laforge@netfilter.org>
   6  *
   7  * Based on the old ipv4-only ip_queue.c:
   8  * (C) 2000-2002 James Morris <jmorris@intercode.com.au>
   9  * (C) 2003-2005 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 #include <linux/module.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/init.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/notifier.h>
  21 #include <linux/netdevice.h>
  22 #include <linux/netfilter.h>
  23 #include <linux/netfilter_ipv4.h>
  24 #include <linux/netfilter_ipv6.h>
  25 #include <linux/netfilter/nfnetlink.h>
  26 #include <linux/netfilter/nfnetlink_queue.h>
  27 #include <linux/list.h>
  28 #include <net/sock.h>
  29
  30 #include <asm/atomic.h>
  31
  32 #define NFQNL_QMAX_DEFAULT 1024
  33
  34 #if 0
  35 #define QDEBUG(x, args ...)     printk(KERN_DEBUG "%s(%d):%s(): " x,       \
  36                                         __FILE__, __LINE__, __FUNCTION__,  \
  37                                         ## args)
  38 #else
  39 #define QDEBUG(x, ...)
  40 #endif
  41
  42 struct nfqnl_queue_entry {
  43         struct list_head list;
  44         struct nf_info *info;
  45         struct sk_buff *skb;
  46         unsigned int id;
  47 };
  48
  49 struct nfqnl_instance {
  50         struct hlist_node hlist;                /* global list of queues */
  51
  52         int peer_pid;
  53         unsigned int queue_maxlen;
  54         unsigned int copy_range;
  55         unsigned int queue_total;
  56         unsigned int queue_dropped;
  57         unsigned int queue_user_dropped;
  58
  59         atomic_t id_sequence;                   /* 'sequence' of pkt ids */
  60
  61         u_int16_t queue_num;                    /* number of this queue */
  62         u_int8_t copy_mode;
  63
  64         spinlock_t lock;
  65
  66         struct list_head queue_list;            /* packets in queue */
  67 };
  68
  69 typedef int (*nfqnl_cmpfn)(struct nfqnl_queue_entry *, unsigned long);
  70
  71 static DEFINE_RWLOCK(instances_lock);
  72
  73 u_int64_t htonll(u_int64_t in)
  74 {
  75         u_int64_t out;
  76         int i;
  77
  78         for (i = 0; i < sizeof(u_int64_t); i++)
  79                 ((u_int8_t *)&out)[sizeof(u_int64_t)-1] = ((u_int8_t *)&in)[i];
  80
  81         return out;
  82 }
  83
  84 #define INSTANCE_BUCKETS        16
  85 static struct hlist_head instance_table[INSTANCE_BUCKETS];
  86
  87 static inline u_int8_t instance_hashfn(u_int16_t queue_num)
  88 {
  89         return ((queue_num >> 8) | queue_num) % INSTANCE_BUCKETS;
  90 }
  91
  92 static struct nfqnl_instance *
  93 __instance_lookup(u_int16_t queue_num)
  94 {
  95         struct hlist_head *head;
  96         struct hlist_node *pos;
  97         struct nfqnl_instance *inst;
  98
  99         head = &instance_table[instance_hashfn(queue_num)];
 100         hlist_for_each_entry(inst, pos, head, hlist) {
 101                 if (inst->queue_num == queue_num)
 102                         return inst;
 103         }
 104         return NULL;
 105 }
 106
 107 static struct nfqnl_instance *
 108 instance_lookup(u_int16_t queue_num)
 109 {
 110         struct nfqnl_instance *inst;
 111
 112         read_lock_bh(&instances_lock);
 113         inst = __instance_lookup(queue_num);
 114         read_unlock_bh(&instances_lock);
 115
 116         return inst;
 117 }
 118
 119 static struct nfqnl_instance *
 120 instance_create(u_int16_t queue_num, int pid)
 121 {
 122         struct nfqnl_instance *inst;
 123
 124         QDEBUG("entering for queue_num=%u, pid=%d\n", queue_num, pid);
 125
 126         write_lock_bh(&instances_lock);
 127         if (__instance_lookup(queue_num)) {
 128                 inst = NULL;
 129                 QDEBUG("aborting, instance already exists\n");
 130                 goto out_unlock;
 131         }
 132
 133         inst = kmalloc(sizeof(*inst), GFP_ATOMIC);
 134         if (!inst)
 135                 goto out_unlock;
 136
 137         memset(inst, 0, sizeof(*inst));
 138         inst->queue_num = queue_num;
 139         inst->peer_pid = pid;
 140         inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
 141         inst->copy_range = 0xfffff;
 142         inst->copy_mode = NFQNL_COPY_NONE;
 143         atomic_set(&inst->id_sequence, 0);
 144         inst->lock = SPIN_LOCK_UNLOCKED;
 145         INIT_LIST_HEAD(&inst->queue_list);
 146
 147         if (!try_module_get(THIS_MODULE))
 148                 goto out_free;
 149
 150         hlist_add_head(&inst->hlist,
 151                        &instance_table[instance_hashfn(queue_num)]);
 152
 153         write_unlock_bh(&instances_lock);
 154
 155         QDEBUG("successfully created new instance\n");
 156
 157         return inst;
 158
 159 out_free:
 160         kfree(inst);
 161 out_unlock:
 162         write_unlock_bh(&instances_lock);
 163         return NULL;
 164 }
 165
 166 static void nfqnl_flush(struct nfqnl_instance *queue, int verdict);
 167
 168 static void
 169 _instance_destroy2(struct nfqnl_instance *inst, int lock)
 170 {
 171         /* first pull it out of the global list */
 172         if (lock)
 173                 write_lock_bh(&instances_lock);
 174
 175         QDEBUG("removing instance %p (queuenum=%u) from hash\n",
 176                 inst, inst->queue_num);
 177         hlist_del(&inst->hlist);
 178
 179         if (lock)
 180                 write_unlock_bh(&instances_lock);
 181
 182         /* then flush all pending skbs from the queue */
 183         nfqnl_flush(inst, NF_DROP);
 184
 185         /* and finally free the data structure */
 186         kfree(inst);
 187
 188         module_put(THIS_MODULE);
 189 }
 190
 191 static inline void
 192 __instance_destroy(struct nfqnl_instance *inst)
 193 {
 194         _instance_destroy2(inst, 0);
 195 }
 196
 197 static inline void
 198 instance_destroy(struct nfqnl_instance *inst)
 199 {
 200         _instance_destroy2(inst, 1);
 201 }
 202
 203
 204
 205 static void
 206 issue_verdict(struct nfqnl_queue_entry *entry, int verdict)
 207 {
 208         QDEBUG("entering for entry %p, verdict %u\n", entry, verdict);
 209
 210         /* TCP input path (and probably other bits) assume to be called
 211          * from softirq context, not from syscall, like issue_verdict is
 212          * called.  TCP input path deadlocks with locks taken from timer
 213          * softirq, e.g.  We therefore emulate this by local_bh_disable() */
 214
 215         local_bh_disable();
 216         nf_reinject(entry->skb, entry->info, verdict);
 217         local_bh_enable();
 218
 219         kfree(entry);
 220 }
 221
 222 static inline void
 223 __enqueue_entry(struct nfqnl_instance *queue,
 224                       struct nfqnl_queue_entry *entry)
 225 {
 226        list_add(&entry->list, &queue->queue_list);
 227        queue->queue_total++;
 228 }
 229
 230 /*
 231  * Find and return a queued entry matched by cmpfn, or return the last
 232  * entry if cmpfn is NULL.
 233  */
 234 static inline struct nfqnl_queue_entry *
 235 __find_entry(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
 236                    unsigned long data)
 237 {
 238         struct list_head *p;
 239
 240         list_for_each_prev(p, &queue->queue_list) {
 241                 struct nfqnl_queue_entry *entry = (struct nfqnl_queue_entry *)p;
 242
 243                 if (!cmpfn || cmpfn(entry, data))
 244                         return entry;
 245         }
 246         return NULL;
 247 }
 248
 249 static inline void
 250 __dequeue_entry(struct nfqnl_instance *q, struct nfqnl_queue_entry *entry)
 251 {
 252         list_del(&entry->list);
 253         q->queue_total--;
 254 }
 255
 256 static inline struct nfqnl_queue_entry *
 257 __find_dequeue_entry(struct nfqnl_instance *queue,
 258                      nfqnl_cmpfn cmpfn, unsigned long data)
 259 {
 260         struct nfqnl_queue_entry *entry;
 261
 262         entry = __find_entry(queue, cmpfn, data);
 263         if (entry == NULL)
 264                 return NULL;
 265
 266         __dequeue_entry(queue, entry);
 267         return entry;
 268 }
 269
 270
 271 static inline void
 272 __nfqnl_flush(struct nfqnl_instance *queue, int verdict)
 273 {
 274         struct nfqnl_queue_entry *entry;
 275
 276         while ((entry = __find_dequeue_entry(queue, NULL, 0)))
 277                 issue_verdict(entry, verdict);
 278 }
 279
 280 static inline int
 281 __nfqnl_set_mode(struct nfqnl_instance *queue,
 282                  unsigned char mode, unsigned int range)
 283 {
 284         int status = 0;
 285
 286         switch (mode) {
 287         case NFQNL_COPY_NONE:
 288         case NFQNL_COPY_META:
 289                 queue->copy_mode = mode;
 290                 queue->copy_range = 0;
 291                 break;
 292
 293         case NFQNL_COPY_PACKET:
 294                 queue->copy_mode = mode;
 295                 /* we're using struct nfattr which has 16bit nfa_len */
 296                 if (range > 0xffff)
 297                         queue->copy_range = 0xffff;
 298                 else
 299                         queue->copy_range = range;
 300                 break;
 301
 302         default:
 303                 status = -EINVAL;
 304
 305         }
 306         return status;
 307 }
 308
 309 static struct nfqnl_queue_entry *
 310 find_dequeue_entry(struct nfqnl_instance *queue,
 311                          nfqnl_cmpfn cmpfn, unsigned long data)
 312 {
 313         struct nfqnl_queue_entry *entry;
 314
 315         spin_lock_bh(&queue->lock);
 316         entry = __find_dequeue_entry(queue, cmpfn, data);
 317         spin_unlock_bh(&queue->lock);
 318
 319         return entry;
 320 }
 321
 322 static void
 323 nfqnl_flush(struct nfqnl_instance *queue, int verdict)
 324 {
 325         spin_lock_bh(&queue->lock);
 326         __nfqnl_flush(queue, verdict);
 327         spin_unlock_bh(&queue->lock);
 328 }
 329
 330 static struct sk_buff *
 331 nfqnl_build_packet_message(struct nfqnl_instance *queue,
 332                            struct nfqnl_queue_entry *entry, int *errp)
 333 {
 334         unsigned char *old_tail;
 335         size_t size;
 336         size_t data_len = 0;
 337         struct sk_buff *skb;
 338         struct nfqnl_msg_packet_hdr pmsg;
 339         struct nlmsghdr *nlh;
 340         struct nfgenmsg *nfmsg;
 341         unsigned int tmp_uint;
 342
 343         QDEBUG("entered\n");
 344
 345         /* all macros expand to constant values at compile time */
 346         size =    NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hdr))
 347                 + NLMSG_SPACE(sizeof(u_int32_t))        /* ifindex */
 348                 + NLMSG_SPACE(sizeof(u_int32_t))        /* ifindex */
 349                 + NLMSG_SPACE(sizeof(u_int32_t))        /* mark */
 350                 + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hw))
 351                 + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_timestamp));
 352
 353         spin_lock_bh(&queue->lock);
 354
 355         switch (queue->copy_mode) {
 356         case NFQNL_COPY_META:
 357         case NFQNL_COPY_NONE:
 358                 data_len = 0;
 359                 break;
 360
 361         case NFQNL_COPY_PACKET:
 362                 if (queue->copy_range == 0
 363                     || queue->copy_range > entry->skb->len)
 364                         data_len = entry->skb->len;
 365                 else
 366                         data_len = queue->copy_range;
 367
 368                 size += NLMSG_SPACE(data_len);
 369                 break;
 370
 371         default:
 372                 *errp = -EINVAL;
 373                 spin_unlock_bh(&queue->lock);
 374                 return NULL;
 375         }
 376
 377         spin_unlock_bh(&queue->lock);
 378
 379         skb = alloc_skb(size, GFP_ATOMIC);
 380         if (!skb)
 381                 goto nlmsg_failure;
 382
 383         old_tail= skb->tail;
 384         nlh = NLMSG_PUT(skb, 0, 0,
 385                         NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET,
 386                         sizeof(struct nfgenmsg));
 387         nfmsg = NLMSG_DATA(nlh);
 388         nfmsg->nfgen_family = entry->info->pf;
 389         nfmsg->version = NFNETLINK_V0;
 390         nfmsg->res_id = htons(queue->queue_num);
 391
 392         pmsg.packet_id          = htonl(entry->id);
 393         pmsg.hw_protocol        = htons(entry->skb->protocol);
 394         pmsg.hook               = entry->info->hook;
 395
 396         NFA_PUT(skb, NFQA_PACKET_HDR, sizeof(pmsg), &pmsg);
 397
 398         if (entry->info->indev) {
 399                 tmp_uint = htonl(entry->info->indev->ifindex);
 400                 NFA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint), &tmp_uint);
 401         }
 402
 403         if (entry->info->outdev) {
 404                 tmp_uint = htonl(entry->info->outdev->ifindex);
 405                 NFA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint), &tmp_uint);
 406         }
 407
 408         if (entry->skb->nfmark) {
 409                 tmp_uint = htonl(entry->skb->nfmark);
 410                 NFA_PUT(skb, NFQA_MARK, sizeof(u_int32_t), &tmp_uint);
 411         }
 412
 413         if (entry->info->indev && entry->skb->dev
 414             && entry->skb->dev->hard_header_parse) {
 415                 struct nfqnl_msg_packet_hw phw;
 416
 417                 phw.hw_addrlen =
 418                         entry->skb->dev->hard_header_parse(entry->skb,
 419                                                            phw.hw_addr);
 420                 phw.hw_addrlen = htons(phw.hw_addrlen);
 421                 NFA_PUT(skb, NFQA_HWADDR, sizeof(phw), &phw);
 422         }
 423
 424         if (entry->skb->stamp.tv_sec) {
 425                 struct nfqnl_msg_packet_timestamp ts;
 426
 427                 ts.sec = htonll(entry->skb->stamp.tv_sec);
 428                 ts.usec = htonll(entry->skb->stamp.tv_usec);
 429
 430                 NFA_PUT(skb, NFQA_TIMESTAMP, sizeof(ts), &ts);
 431         }
 432
 433         if (data_len) {
 434                 struct nfattr *nfa;
 435                 int size = NFA_LENGTH(data_len);
 436
 437                 if (skb_tailroom(skb) < (int)NFA_SPACE(data_len)) {
 438                         printk(KERN_WARNING "nf_queue: no tailroom!\n");
 439                         goto nlmsg_failure;
 440                 }
 441
 442                 nfa = (struct nfattr *)skb_put(skb, NFA_ALIGN(size));
 443                 nfa->nfa_type = NFQA_PAYLOAD;
 444                 nfa->nfa_len = size;
 445
 446                 if (skb_copy_bits(entry->skb, 0, NFA_DATA(nfa), data_len))
 447                         BUG();
 448         }
 449
 450         nlh->nlmsg_len = skb->tail - old_tail;
 451         return skb;
 452
 453 nlmsg_failure:
 454 nfattr_failure:
 455         if (skb)
 456                 kfree_skb(skb);
 457         *errp = -EINVAL;
 458         if (net_ratelimit())
 459                 printk(KERN_ERR "nf_queue: error creating packet message\n");
 460         return NULL;
 461 }
 462
 463 static int
 464 nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
 465                      unsigned int queuenum, void *data)
 466 {
 467         int status = -EINVAL;
 468         struct sk_buff *nskb;
 469         struct nfqnl_instance *queue;
 470         struct nfqnl_queue_entry *entry;
 471
 472         QDEBUG("entered\n");
 473
 474         queue = instance_lookup(queuenum);
 475         if (!queue) {
 476                 QDEBUG("no queue instance matching\n");
 477                 return -EINVAL;
 478         }
 479
 480         if (queue->copy_mode == NFQNL_COPY_NONE) {
 481                 QDEBUG("mode COPY_NONE, aborting\n");
 482                 return -EAGAIN;
 483         }
 484
 485         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 486         if (entry == NULL) {
 487                 if (net_ratelimit())
 488                         printk(KERN_ERR
 489                                 "nf_queue: OOM in nfqnl_enqueue_packet()\n");
 490                 return -ENOMEM;
 491         }
 492
 493         entry->info = info;
 494         entry->skb = skb;
 495         entry->id = atomic_inc_return(&queue->id_sequence);
 496
 497         nskb = nfqnl_build_packet_message(queue, entry, &status);
 498         if (nskb == NULL)
 499                 goto err_out_free;
 500
 501         spin_lock_bh(&queue->lock);
 502
 503         if (!queue->peer_pid)
 504                 goto err_out_free_nskb;
 505
 506         if (queue->queue_total >= queue->queue_maxlen) {
 507                 queue->queue_dropped++;
 508                 status = -ENOSPC;
 509                 if (net_ratelimit())
 510                           printk(KERN_WARNING "ip_queue: full at %d entries, "
 511                                  "dropping packets(s). Dropped: %d\n",
 512                                  queue->queue_total, queue->queue_dropped);
 513                 goto err_out_free_nskb;
 514         }
 515
 516         /* nfnetlink_unicast will either free the nskb or add it to a socket */
 517         status = nfnetlink_unicast(nskb, queue->peer_pid, MSG_DONTWAIT);
 518         if (status < 0) {
 519                 queue->queue_user_dropped++;
 520                 goto err_out_unlock;
 521         }
 522
 523         __enqueue_entry(queue, entry);
 524
 525         spin_unlock_bh(&queue->lock);
 526         return status;
 527
 528 err_out_free_nskb:
 529         kfree_skb(nskb);
 530
 531 err_out_unlock:
 532         spin_unlock_bh(&queue->lock);
 533
 534 err_out_free:
 535         kfree(entry);
 536         return status;
 537 }
 538
 539 static int
 540 nfqnl_mangle(void *data, int data_len, struct nfqnl_queue_entry *e)
 541 {
 542         int diff;
 543
 544         diff = data_len - e->skb->len;
 545         if (diff < 0)
 546                 skb_trim(e->skb, data_len);
 547         else if (diff > 0) {
 548                 if (data_len > 0xFFFF)
 549                         return -EINVAL;
 550                 if (diff > skb_tailroom(e->skb)) {
 551                         struct sk_buff *newskb;
 552
 553                         newskb = skb_copy_expand(e->skb,
 554                                                  skb_headroom(e->skb),
 555                                                  diff,
 556                                                  GFP_ATOMIC);
 557                         if (newskb == NULL) {
 558                                 printk(KERN_WARNING "ip_queue: OOM "
 559                                       "in mangle, dropping packet\n");
 560                                 return -ENOMEM;
 561                         }
 562                         if (e->skb->sk)
 563                                 skb_set_owner_w(newskb, e->skb->sk);
 564                         kfree_skb(e->skb);
 565                         e->skb = newskb;
 566                 }
 567                 skb_put(e->skb, diff);
 568         }
 569         if (!skb_make_writable(&e->skb, data_len))
 570                 return -ENOMEM;
 571         memcpy(e->skb->data, data, data_len);
 572
 573         return 0;
 574 }
 575
 576 static inline int
 577 id_cmp(struct nfqnl_queue_entry *e, unsigned long id)
 578 {
 579         return (id == e->id);
 580 }
 581
 582 static int
 583 nfqnl_set_mode(struct nfqnl_instance *queue,
 584                unsigned char mode, unsigned int range)
 585 {
 586         int status;
 587
 588         spin_lock_bh(&queue->lock);
 589         status = __nfqnl_set_mode(queue, mode, range);
 590         spin_unlock_bh(&queue->lock);
 591
 592         return status;
 593 }
 594
 595 static int
 596 dev_cmp(struct nfqnl_queue_entry *entry, unsigned long ifindex)
 597 {
 598         if (entry->info->indev)
 599                 if (entry->info->indev->ifindex == ifindex)
 600                         return 1;
 601
 602         if (entry->info->outdev)
 603                 if (entry->info->outdev->ifindex == ifindex)
 604                         return 1;
 605
 606         return 0;
 607 }
 608
 609 /* drop all packets with either indev or outdev == ifindex from all queue
 610  * instances */
 611 static void
 612 nfqnl_dev_drop(int ifindex)
 613 {
 614         int i;
 615
 616         QDEBUG("entering for ifindex %u\n", ifindex);
 617
 618         /* this only looks like we have to hold the readlock for a way too long
 619          * time, issue_verdict(),  nf_reinject(), ... - but we always only
 620          * issue NF_DROP, which is processed directly in nf_reinject() */
 621         read_lock_bh(&instances_lock);
 622
 623         for  (i = 0; i < INSTANCE_BUCKETS; i++) {
 624                 struct hlist_node *tmp;
 625                 struct nfqnl_instance *inst;
 626                 struct hlist_head *head = &instance_table[i];
 627
 628                 hlist_for_each_entry(inst, tmp, head, hlist) {
 629                         struct nfqnl_queue_entry *entry;
 630                         while ((entry = find_dequeue_entry(inst, dev_cmp,
 631                                                            ifindex)) != NULL)
 632                                 issue_verdict(entry, NF_DROP);
 633                 }
 634         }
 635
 636         read_unlock_bh(&instances_lock);
 637 }
 638
 639 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 640
 641 static int
 642 nfqnl_rcv_dev_event(struct notifier_block *this,
 643                     unsigned long event, void *ptr)
 644 {
 645         struct net_device *dev = ptr;
 646
 647         /* Drop any packets associated with the downed device */
 648         if (event == NETDEV_DOWN)
 649                 nfqnl_dev_drop(dev->ifindex);
 650         return NOTIFY_DONE;
 651 }
 652
 653 static struct notifier_block nfqnl_dev_notifier = {
 654         .notifier_call  = nfqnl_rcv_dev_event,
 655 };
 656
 657 static int
 658 nfqnl_rcv_nl_event(struct notifier_block *this,
 659                    unsigned long event, void *ptr)
 660 {
 661         struct netlink_notify *n = ptr;
 662
 663         if (event == NETLINK_URELEASE &&
 664             n->protocol == NETLINK_NETFILTER && n->pid) {
 665                 int i;
 666
 667                 /* destroy all instances for this pid */
 668                 write_lock_bh(&instances_lock);
 669                 for  (i = 0; i < INSTANCE_BUCKETS; i++) {
 670                         struct hlist_node *tmp, *t2;
 671                         struct nfqnl_instance *inst;
 672                         struct hlist_head *head = &instance_table[i];
 673
 674                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
 675                                 if (n->pid == inst->peer_pid)
 676                                         __instance_destroy(inst);
 677                         }
 678                 }
 679                 write_unlock_bh(&instances_lock);
 680         }
 681         return NOTIFY_DONE;
 682 }
 683
 684 static struct notifier_block nfqnl_rtnl_notifier = {
 685         .notifier_call  = nfqnl_rcv_nl_event,
 686 };
 687
 688 static int
 689 nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
 690                    struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
 691 {
 692         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 693         u_int16_t queue_num = ntohs(nfmsg->res_id);
 694
 695         struct nfqnl_msg_verdict_hdr *vhdr;
 696         struct nfqnl_instance *queue;
 697         unsigned int verdict;
 698         struct nfqnl_queue_entry *entry;
 699
 700         queue = instance_lookup(queue_num);
 701         if (!queue)
 702                 return -ENODEV;
 703
 704         if (queue->peer_pid != NETLINK_CB(skb).pid)
 705                 return -EPERM;
 706
 707         if (!nfqa[NFQA_VERDICT_HDR-1])
 708                 return -EINVAL;
 709
 710         vhdr = NFA_DATA(nfqa[NFQA_VERDICT_HDR-1]);
 711         verdict = ntohl(vhdr->verdict);
 712
 713         if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT)
 714                 return -EINVAL;
 715
 716         entry = find_dequeue_entry(queue, id_cmp, ntohl(vhdr->id));
 717         if (entry == NULL)
 718                 return -ENOENT;
 719
 720         if (nfqa[NFQA_PAYLOAD-1]) {
 721                 if (nfqnl_mangle(NFA_DATA(nfqa[NFQA_PAYLOAD-1]),
 722                                  NFA_PAYLOAD(nfqa[NFQA_PAYLOAD-1]), entry) < 0)
 723                         verdict = NF_DROP;
 724         }
 725
 726         if (nfqa[NFQA_MARK-1])
 727                 skb->nfmark = ntohl(*(u_int32_t *)NFA_DATA(nfqa[NFQA_MARK-1]));
 728
 729         issue_verdict(entry, verdict);
 730         return 0;
 731 }
 732
 733 static int
 734 nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
 735                   struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
 736 {
 737         return -ENOTSUPP;
 738 }
 739
 740 static int
 741 nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 742                   struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
 743 {
 744         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 745         u_int16_t queue_num = ntohs(nfmsg->res_id);
 746         struct nfqnl_instance *queue;
 747
 748         QDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
 749
 750         queue = instance_lookup(queue_num);
 751         if (nfqa[NFQA_CFG_CMD-1]) {
 752                 struct nfqnl_msg_config_cmd *cmd;
 753                 cmd = NFA_DATA(nfqa[NFQA_CFG_CMD-1]);
 754                 QDEBUG("found CFG_CMD\n");
 755
 756                 switch (cmd->command) {
 757                 case NFQNL_CFG_CMD_BIND:
 758                         if (queue)
 759                                 return -EBUSY;
 760
 761                         queue = instance_create(queue_num, NETLINK_CB(skb).pid);
 762                         if (!queue)
 763                                 return -EINVAL;
 764                         break;
 765                 case NFQNL_CFG_CMD_UNBIND:
 766                         if (!queue)
 767                                 return -ENODEV;
 768
 769                         if (queue->peer_pid != NETLINK_CB(skb).pid)
 770                                 return -EPERM;
 771
 772                         instance_destroy(queue);
 773                         break;
 774                 case NFQNL_CFG_CMD_PF_BIND:
 775                         QDEBUG("registering queue handler for pf=%u\n",
 776                                 ntohs(cmd->pf));
 777                         return nf_register_queue_handler(ntohs(cmd->pf),
 778                                                          nfqnl_enqueue_packet,
 779                                                          NULL);
 780
 781                         break;
 782                 case NFQNL_CFG_CMD_PF_UNBIND:
 783                         QDEBUG("unregistering queue handler for pf=%u\n",
 784                                 ntohs(cmd->pf));
 785                         /* This is a bug and a feature.  We can unregister
 786                          * other handlers(!) */
 787                         return nf_unregister_queue_handler(ntohs(cmd->pf));
 788                         break;
 789                 default:
 790                         return -EINVAL;
 791                 }
 792         } else {
 793                 if (!queue) {
 794                         QDEBUG("no config command, and no instance ENOENT\n");
 795                         return -ENOENT;
 796                 }
 797
 798                 if (queue->peer_pid != NETLINK_CB(skb).pid) {
 799                         QDEBUG("no config command, and wrong pid\n");
 800                         return -EPERM;
 801                 }
 802         }
 803
 804         if (nfqa[NFQA_CFG_PARAMS-1]) {
 805                 struct nfqnl_msg_config_params *params;
 806                 params = NFA_DATA(nfqa[NFQA_CFG_PARAMS-1]);
 807
 808                 nfqnl_set_mode(queue, params->copy_mode,
 809                                 ntohl(params->copy_range));
 810         }
 811
 812         return 0;
 813 }
 814
 815 static struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
 816         [NFQNL_MSG_PACKET]      = { .call = nfqnl_recv_unsupp,
 817                                     .cap_required = CAP_NET_ADMIN },
 818         [NFQNL_MSG_VERDICT]     = { .call = nfqnl_recv_verdict,
 819                                     .cap_required = CAP_NET_ADMIN },
 820         [NFQNL_MSG_CONFIG]      = { .call = nfqnl_recv_config,
 821                                     .cap_required = CAP_NET_ADMIN },
 822 };
 823
 824 static struct nfnetlink_subsystem nfqnl_subsys = {
 825         .name           = "nf_queue",
 826         .subsys_id      = NFNL_SUBSYS_QUEUE,
 827         .cb_count       = NFQNL_MSG_MAX,
 828         .attr_count     = NFQA_MAX,
 829         .cb             = nfqnl_cb,
 830 };
 831
 832 static int
 833 init_or_cleanup(int init)
 834 {
 835         int status = -ENOMEM;
 836
 837         if (!init)
 838                 goto cleanup;
 839
 840         netlink_register_notifier(&nfqnl_rtnl_notifier);
 841         status = nfnetlink_subsys_register(&nfqnl_subsys);
 842         if (status < 0) {
 843                 printk(KERN_ERR "nf_queue: failed to create netlink socket\n");
 844                 goto cleanup_netlink_notifier;
 845         }
 846
 847         register_netdevice_notifier(&nfqnl_dev_notifier);
 848         return status;
 849
 850 cleanup:
 851         nf_unregister_queue_handlers(nfqnl_enqueue_packet);
 852         unregister_netdevice_notifier(&nfqnl_dev_notifier);
 853         nfnetlink_subsys_unregister(&nfqnl_subsys);
 854
 855 cleanup_netlink_notifier:
 856         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
 857         return status;
 858 }
 859
 860 static int __init init(void)
 861 {
 862
 863         return init_or_cleanup(1);
 864 }
 865
 866 static void __exit fini(void)
 867 {
 868         init_or_cleanup(0);
 869 }
 870
 871 MODULE_DESCRIPTION("netfilter packet queue handler");
 872 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
 873 MODULE_LICENSE("GPL");
 874 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
 875
 876 module_init(init);
 877 module_exit(fini);