net/netfilter/nfnetlink_queue.c

   1 /*
   2  * This is a module which is used for queueing packets and communicating with
   3  * userspace via nfnetlink.
   4  *
   5  * (C) 2005 by Harald Welte <laforge@netfilter.org>
   6  * (C) 2007 by Patrick McHardy <kaber@trash.net>
   7  *
   8  * Based on the old ipv4-only ip_queue.c:
   9  * (C) 2000-2002 James Morris <jmorris@intercode.com.au>
  10  * (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License version 2 as
  14  * published by the Free Software Foundation.
  15  *
  16  */
  17 #include <linux/module.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/init.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/slab.h>
  22 #include <linux/notifier.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/netfilter.h>
  25 #include <linux/proc_fs.h>
  26 #include <linux/netfilter_ipv4.h>
  27 #include <linux/netfilter_ipv6.h>
  28 #include <linux/netfilter/nfnetlink.h>
  29 #include <linux/netfilter/nfnetlink_queue.h>
  30 #include <linux/list.h>
  31 #include <net/sock.h>
  32 #include <net/netfilter/nf_queue.h>
  33
  34 #include <linux/atomic.h>
  35
  36 #ifdef CONFIG_BRIDGE_NETFILTER
  37 #include "../bridge/br_private.h"
  38 #endif
  39
  40 #define NFQNL_QMAX_DEFAULT 1024
  41
  42 struct nfqnl_instance {
  43         struct hlist_node hlist;                /* global list of queues */
  44         struct rcu_head rcu;
  45
  46         int peer_pid;
  47         unsigned int queue_maxlen;
  48         unsigned int copy_range;
  49         unsigned int queue_dropped;
  50         unsigned int queue_user_dropped;
  51
  52
  53         u_int16_t queue_num;                    /* number of this queue */
  54         u_int8_t copy_mode;
  55 /*
  56  * Following fields are dirtied for each queued packet,
  57  * keep them in same cache line if possible.
  58  */
  59         spinlock_t      lock;
  60         unsigned int    queue_total;
  61         unsigned int    id_sequence;            /* 'sequence' of pkt ids */
  62         struct list_head queue_list;            /* packets in queue */
  63 };
  64
  65 typedef int (*nfqnl_cmpfn)(struct nf_queue_entry *, unsigned long);
  66
  67 static DEFINE_SPINLOCK(instances_lock);
  68
  69 #define INSTANCE_BUCKETS        16
  70 static struct hlist_head instance_table[INSTANCE_BUCKETS] __read_mostly;
  71
  72 static inline u_int8_t instance_hashfn(u_int16_t queue_num)
  73 {
  74         return ((queue_num >> 8) | queue_num) % INSTANCE_BUCKETS;
  75 }
  76
  77 static struct nfqnl_instance *
  78 instance_lookup(u_int16_t queue_num)
  79 {
  80         struct hlist_head *head;
  81         struct hlist_node *pos;
  82         struct nfqnl_instance *inst;
  83
  84         head = &instance_table[instance_hashfn(queue_num)];
  85         hlist_for_each_entry_rcu(inst, pos, head, hlist) {
  86                 if (inst->queue_num == queue_num)
  87                         return inst;
  88         }
  89         return NULL;
  90 }
  91
  92 static struct nfqnl_instance *
  93 instance_create(u_int16_t queue_num, int pid)
  94 {
  95         struct nfqnl_instance *inst;
  96         unsigned int h;
  97         int err;
  98
  99         spin_lock(&instances_lock);
 100         if (instance_lookup(queue_num)) {
 101                 err = -EEXIST;
 102                 goto out_unlock;
 103         }
 104
 105         inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
 106         if (!inst) {
 107                 err = -ENOMEM;
 108                 goto out_unlock;
 109         }
 110
 111         inst->queue_num = queue_num;
 112         inst->peer_pid = pid;
 113         inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
 114         inst->copy_range = 0xfffff;
 115         inst->copy_mode = NFQNL_COPY_NONE;
 116         spin_lock_init(&inst->lock);
 117         INIT_LIST_HEAD(&inst->queue_list);
 118
 119         if (!try_module_get(THIS_MODULE)) {
 120                 err = -EAGAIN;
 121                 goto out_free;
 122         }
 123
 124         h = instance_hashfn(queue_num);
 125         hlist_add_head_rcu(&inst->hlist, &instance_table[h]);
 126
 127         spin_unlock(&instances_lock);
 128
 129         return inst;
 130
 131 out_free:
 132         kfree(inst);
 133 out_unlock:
 134         spin_unlock(&instances_lock);
 135         return ERR_PTR(err);
 136 }
 137
 138 static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
 139                         unsigned long data);
 140
 141 static void
 142 instance_destroy_rcu(struct rcu_head *head)
 143 {
 144         struct nfqnl_instance *inst = container_of(head, struct nfqnl_instance,
 145                                                    rcu);
 146
 147         nfqnl_flush(inst, NULL, 0);
 148         kfree(inst);
 149         module_put(THIS_MODULE);
 150 }
 151
 152 static void
 153 __instance_destroy(struct nfqnl_instance *inst)
 154 {
 155         hlist_del_rcu(&inst->hlist);
 156         call_rcu(&inst->rcu, instance_destroy_rcu);
 157 }
 158
 159 static void
 160 instance_destroy(struct nfqnl_instance *inst)
 161 {
 162         spin_lock(&instances_lock);
 163         __instance_destroy(inst);
 164         spin_unlock(&instances_lock);
 165 }
 166
 167 static inline void
 168 __enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
 169 {
 170        list_add_tail(&entry->list, &queue->queue_list);
 171        queue->queue_total++;
 172 }
 173
 174 static void
 175 __dequeue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
 176 {
 177         list_del(&entry->list);
 178         queue->queue_total--;
 179 }
 180
 181 static struct nf_queue_entry *
 182 find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id)
 183 {
 184         struct nf_queue_entry *entry = NULL, *i;
 185
 186         spin_lock_bh(&queue->lock);
 187
 188         list_for_each_entry(i, &queue->queue_list, list) {
 189                 if (i->id == id) {
 190                         entry = i;
 191                         break;
 192                 }
 193         }
 194
 195         if (entry)
 196                 __dequeue_entry(queue, entry);
 197
 198         spin_unlock_bh(&queue->lock);
 199
 200         return entry;
 201 }
 202
 203 static void
 204 nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data)
 205 {
 206         struct nf_queue_entry *entry, *next;
 207
 208         spin_lock_bh(&queue->lock);
 209         list_for_each_entry_safe(entry, next, &queue->queue_list, list) {
 210                 if (!cmpfn || cmpfn(entry, data)) {
 211                         list_del(&entry->list);
 212                         queue->queue_total--;
 213                         nf_reinject(entry, NF_DROP);
 214                 }
 215         }
 216         spin_unlock_bh(&queue->lock);
 217 }
 218
 219 static struct sk_buff *
 220 nfqnl_build_packet_message(struct nfqnl_instance *queue,
 221                            struct nf_queue_entry *entry,
 222                            __be32 **packet_id_ptr)
 223 {
 224         sk_buff_data_t old_tail;
 225         size_t size;
 226         size_t data_len = 0;
 227         struct sk_buff *skb;
 228         struct nlattr *nla;
 229         struct nfqnl_msg_packet_hdr *pmsg;
 230         struct nlmsghdr *nlh;
 231         struct nfgenmsg *nfmsg;
 232         struct sk_buff *entskb = entry->skb;
 233         struct net_device *indev;
 234         struct net_device *outdev;
 235
 236         size =    NLMSG_SPACE(sizeof(struct nfgenmsg))
 237                 + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
 238                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 239                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 240 #ifdef CONFIG_BRIDGE_NETFILTER
 241                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 242                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 243 #endif
 244                 + nla_total_size(sizeof(u_int32_t))     /* mark */
 245                 + nla_total_size(sizeof(struct nfqnl_msg_packet_hw))
 246                 + nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp));
 247
 248         outdev = entry->outdev;
 249
 250         switch ((enum nfqnl_config_mode)ACCESS_ONCE(queue->copy_mode)) {
 251         case NFQNL_COPY_META:
 252         case NFQNL_COPY_NONE:
 253                 break;
 254
 255         case NFQNL_COPY_PACKET:
 256                 if (entskb->ip_summed == CHECKSUM_PARTIAL &&
 257                     skb_checksum_help(entskb))
 258                         return NULL;
 259
 260                 data_len = ACCESS_ONCE(queue->copy_range);
 261                 if (data_len == 0 || data_len > entskb->len)
 262                         data_len = entskb->len;
 263
 264                 size += nla_total_size(data_len);
 265                 break;
 266         }
 267
 268
 269         skb = alloc_skb(size, GFP_ATOMIC);
 270         if (!skb)
 271                 goto nlmsg_failure;
 272
 273         old_tail = skb->tail;
 274         nlh = NLMSG_PUT(skb, 0, 0,
 275                         NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET,
 276                         sizeof(struct nfgenmsg));
 277         nfmsg = NLMSG_DATA(nlh);
 278         nfmsg->nfgen_family = entry->pf;
 279         nfmsg->version = NFNETLINK_V0;
 280         nfmsg->res_id = htons(queue->queue_num);
 281
 282         nla = __nla_reserve(skb, NFQA_PACKET_HDR, sizeof(*pmsg));
 283         pmsg = nla_data(nla);
 284         pmsg->hw_protocol       = entskb->protocol;
 285         pmsg->hook              = entry->hook;
 286         *packet_id_ptr          = &pmsg->packet_id;
 287
 288         indev = entry->indev;
 289         if (indev) {
 290 #ifndef CONFIG_BRIDGE_NETFILTER
 291                 NLA_PUT_BE32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex));
 292 #else
 293                 if (entry->pf == PF_BRIDGE) {
 294                         /* Case 1: indev is physical input device, we need to
 295                          * look for bridge group (when called from
 296                          * netfilter_bridge) */
 297                         NLA_PUT_BE32(skb, NFQA_IFINDEX_PHYSINDEV,
 298                                      htonl(indev->ifindex));
 299                         /* this is the bridge group "brX" */
 300                         /* rcu_read_lock()ed by __nf_queue */
 301                         NLA_PUT_BE32(skb, NFQA_IFINDEX_INDEV,
 302                                      htonl(br_port_get_rcu(indev)->br->dev->ifindex));
 303                 } else {
 304                         /* Case 2: indev is bridge group, we need to look for
 305                          * physical device (when called from ipv4) */
 306                         NLA_PUT_BE32(skb, NFQA_IFINDEX_INDEV,
 307                                      htonl(indev->ifindex));
 308                         if (entskb->nf_bridge && entskb->nf_bridge->physindev)
 309                                 NLA_PUT_BE32(skb, NFQA_IFINDEX_PHYSINDEV,
 310                                              htonl(entskb->nf_bridge->physindev->ifindex));
 311                 }
 312 #endif
 313         }
 314
 315         if (outdev) {
 316 #ifndef CONFIG_BRIDGE_NETFILTER
 317                 NLA_PUT_BE32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex));
 318 #else
 319                 if (entry->pf == PF_BRIDGE) {
 320                         /* Case 1: outdev is physical output device, we need to
 321                          * look for bridge group (when called from
 322                          * netfilter_bridge) */
 323                         NLA_PUT_BE32(skb, NFQA_IFINDEX_PHYSOUTDEV,
 324                                      htonl(outdev->ifindex));
 325                         /* this is the bridge group "brX" */
 326                         /* rcu_read_lock()ed by __nf_queue */
 327                         NLA_PUT_BE32(skb, NFQA_IFINDEX_OUTDEV,
 328                                      htonl(br_port_get_rcu(outdev)->br->dev->ifindex));
 329                 } else {
 330                         /* Case 2: outdev is bridge group, we need to look for
 331                          * physical output device (when called from ipv4) */
 332                         NLA_PUT_BE32(skb, NFQA_IFINDEX_OUTDEV,
 333                                      htonl(outdev->ifindex));
 334                         if (entskb->nf_bridge && entskb->nf_bridge->physoutdev)
 335                                 NLA_PUT_BE32(skb, NFQA_IFINDEX_PHYSOUTDEV,
 336                                              htonl(entskb->nf_bridge->physoutdev->ifindex));
 337                 }
 338 #endif
 339         }
 340
 341         if (entskb->mark)
 342                 NLA_PUT_BE32(skb, NFQA_MARK, htonl(entskb->mark));
 343
 344         if (indev && entskb->dev &&
 345             entskb->mac_header != entskb->network_header) {
 346                 struct nfqnl_msg_packet_hw phw;
 347                 int len = dev_parse_header(entskb, phw.hw_addr);
 348                 if (len) {
 349                         phw.hw_addrlen = htons(len);
 350                         NLA_PUT(skb, NFQA_HWADDR, sizeof(phw), &phw);
 351                 }
 352         }
 353
 354         if (entskb->tstamp.tv64) {
 355                 struct nfqnl_msg_packet_timestamp ts;
 356                 struct timeval tv = ktime_to_timeval(entskb->tstamp);
 357                 ts.sec = cpu_to_be64(tv.tv_sec);
 358                 ts.usec = cpu_to_be64(tv.tv_usec);
 359
 360                 NLA_PUT(skb, NFQA_TIMESTAMP, sizeof(ts), &ts);
 361         }
 362
 363         if (data_len) {
 364                 struct nlattr *nla;
 365                 int sz = nla_attr_size(data_len);
 366
 367                 if (skb_tailroom(skb) < nla_total_size(data_len)) {
 368                         printk(KERN_WARNING "nf_queue: no tailroom!\n");
 369                         goto nlmsg_failure;
 370                 }
 371
 372                 nla = (struct nlattr *)skb_put(skb, nla_total_size(data_len));
 373                 nla->nla_type = NFQA_PAYLOAD;
 374                 nla->nla_len = sz;
 375
 376                 if (skb_copy_bits(entskb, 0, nla_data(nla), data_len))
 377                         BUG();
 378         }
 379
 380         nlh->nlmsg_len = skb->tail - old_tail;
 381         return skb;
 382
 383 nlmsg_failure:
 384 nla_put_failure:
 385         if (skb)
 386                 kfree_skb(skb);
 387         if (net_ratelimit())
 388                 printk(KERN_ERR "nf_queue: error creating packet message\n");
 389         return NULL;
 390 }
 391
 392 static int
 393 nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
 394 {
 395         struct sk_buff *nskb;
 396         struct nfqnl_instance *queue;
 397         int err = -ENOBUFS;
 398         __be32 *packet_id_ptr;
 399
 400         /* rcu_read_lock()ed by nf_hook_slow() */
 401         queue = instance_lookup(queuenum);
 402         if (!queue) {
 403                 err = -ESRCH;
 404                 goto err_out;
 405         }
 406
 407         if (queue->copy_mode == NFQNL_COPY_NONE) {
 408                 err = -EINVAL;
 409                 goto err_out;
 410         }
 411
 412         nskb = nfqnl_build_packet_message(queue, entry, &packet_id_ptr);
 413         if (nskb == NULL) {
 414                 err = -ENOMEM;
 415                 goto err_out;
 416         }
 417         spin_lock_bh(&queue->lock);
 418
 419         if (!queue->peer_pid) {
 420                 err = -EINVAL;
 421                 goto err_out_free_nskb;
 422         }
 423         if (queue->queue_total >= queue->queue_maxlen) {
 424                 queue->queue_dropped++;
 425                 if (net_ratelimit())
 426                           printk(KERN_WARNING "nf_queue: full at %d entries, "
 427                                  "dropping packets(s).\n",
 428                                  queue->queue_total);
 429                 goto err_out_free_nskb;
 430         }
 431         entry->id = ++queue->id_sequence;
 432         *packet_id_ptr = htonl(entry->id);
 433
 434         /* nfnetlink_unicast will either free the nskb or add it to a socket */
 435         err = nfnetlink_unicast(nskb, &init_net, queue->peer_pid, MSG_DONTWAIT);
 436         if (err < 0) {
 437                 queue->queue_user_dropped++;
 438                 goto err_out_unlock;
 439         }
 440
 441         __enqueue_entry(queue, entry);
 442
 443         spin_unlock_bh(&queue->lock);
 444         return 0;
 445
 446 err_out_free_nskb:
 447         kfree_skb(nskb);
 448 err_out_unlock:
 449         spin_unlock_bh(&queue->lock);
 450 err_out:
 451         return err;
 452 }
 453
 454 static int
 455 nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e)
 456 {
 457         struct sk_buff *nskb;
 458         int diff;
 459
 460         diff = data_len - e->skb->len;
 461         if (diff < 0) {
 462                 if (pskb_trim(e->skb, data_len))
 463                         return -ENOMEM;
 464         } else if (diff > 0) {
 465                 if (data_len > 0xFFFF)
 466                         return -EINVAL;
 467                 if (diff > skb_tailroom(e->skb)) {
 468                         nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
 469                                                diff, GFP_ATOMIC);
 470                         if (!nskb) {
 471                                 printk(KERN_WARNING "nf_queue: OOM "
 472                                       "in mangle, dropping packet\n");
 473                                 return -ENOMEM;
 474                         }
 475                         kfree_skb(e->skb);
 476                         e->skb = nskb;
 477                 }
 478                 skb_put(e->skb, diff);
 479         }
 480         if (!skb_make_writable(e->skb, data_len))
 481                 return -ENOMEM;
 482         skb_copy_to_linear_data(e->skb, data, data_len);
 483         e->skb->ip_summed = CHECKSUM_NONE;
 484         return 0;
 485 }
 486
 487 static int
 488 nfqnl_set_mode(struct nfqnl_instance *queue,
 489                unsigned char mode, unsigned int range)
 490 {
 491         int status = 0;
 492
 493         spin_lock_bh(&queue->lock);
 494         switch (mode) {
 495         case NFQNL_COPY_NONE:
 496         case NFQNL_COPY_META:
 497                 queue->copy_mode = mode;
 498                 queue->copy_range = 0;
 499                 break;
 500
 501         case NFQNL_COPY_PACKET:
 502                 queue->copy_mode = mode;
 503                 /* we're using struct nlattr which has 16bit nla_len */
 504                 if (range > 0xffff)
 505                         queue->copy_range = 0xffff;
 506                 else
 507                         queue->copy_range = range;
 508                 break;
 509
 510         default:
 511                 status = -EINVAL;
 512
 513         }
 514         spin_unlock_bh(&queue->lock);
 515
 516         return status;
 517 }
 518
 519 static int
 520 dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
 521 {
 522         if (entry->indev)
 523                 if (entry->indev->ifindex == ifindex)
 524                         return 1;
 525         if (entry->outdev)
 526                 if (entry->outdev->ifindex == ifindex)
 527                         return 1;
 528 #ifdef CONFIG_BRIDGE_NETFILTER
 529         if (entry->skb->nf_bridge) {
 530                 if (entry->skb->nf_bridge->physindev &&
 531                     entry->skb->nf_bridge->physindev->ifindex == ifindex)
 532                         return 1;
 533                 if (entry->skb->nf_bridge->physoutdev &&
 534                     entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
 535                         return 1;
 536         }
 537 #endif
 538         return 0;
 539 }
 540
 541 /* drop all packets with either indev or outdev == ifindex from all queue
 542  * instances */
 543 static void
 544 nfqnl_dev_drop(int ifindex)
 545 {
 546         int i;
 547
 548         rcu_read_lock();
 549
 550         for (i = 0; i < INSTANCE_BUCKETS; i++) {
 551                 struct hlist_node *tmp;
 552                 struct nfqnl_instance *inst;
 553                 struct hlist_head *head = &instance_table[i];
 554
 555                 hlist_for_each_entry_rcu(inst, tmp, head, hlist)
 556                         nfqnl_flush(inst, dev_cmp, ifindex);
 557         }
 558
 559         rcu_read_unlock();
 560 }
 561
 562 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 563
 564 static int
 565 nfqnl_rcv_dev_event(struct notifier_block *this,
 566                     unsigned long event, void *ptr)
 567 {
 568         struct net_device *dev = ptr;
 569
 570         if (!net_eq(dev_net(dev), &init_net))
 571                 return NOTIFY_DONE;
 572
 573         /* Drop any packets associated with the downed device */
 574         if (event == NETDEV_DOWN)
 575                 nfqnl_dev_drop(dev->ifindex);
 576         return NOTIFY_DONE;
 577 }
 578
 579 static struct notifier_block nfqnl_dev_notifier = {
 580         .notifier_call  = nfqnl_rcv_dev_event,
 581 };
 582
 583 static int
 584 nfqnl_rcv_nl_event(struct notifier_block *this,
 585                    unsigned long event, void *ptr)
 586 {
 587         struct netlink_notify *n = ptr;
 588
 589         if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
 590                 int i;
 591
 592                 /* destroy all instances for this pid */
 593                 spin_lock(&instances_lock);
 594                 for (i = 0; i < INSTANCE_BUCKETS; i++) {
 595                         struct hlist_node *tmp, *t2;
 596                         struct nfqnl_instance *inst;
 597                         struct hlist_head *head = &instance_table[i];
 598
 599                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
 600                                 if ((n->net == &init_net) &&
 601                                     (n->pid == inst->peer_pid))
 602                                         __instance_destroy(inst);
 603                         }
 604                 }
 605                 spin_unlock(&instances_lock);
 606         }
 607         return NOTIFY_DONE;
 608 }
 609
 610 static struct notifier_block nfqnl_rtnl_notifier = {
 611         .notifier_call  = nfqnl_rcv_nl_event,
 612 };
 613
 614 static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = {
 615         [NFQA_VERDICT_HDR]      = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
 616         [NFQA_MARK]             = { .type = NLA_U32 },
 617         [NFQA_PAYLOAD]          = { .type = NLA_UNSPEC },
 618 };
 619
 620 static const struct nla_policy nfqa_verdict_batch_policy[NFQA_MAX+1] = {
 621         [NFQA_VERDICT_HDR]      = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
 622         [NFQA_MARK]             = { .type = NLA_U32 },
 623 };
 624
 625 static struct nfqnl_instance *verdict_instance_lookup(u16 queue_num, int nlpid)
 626 {
 627         struct nfqnl_instance *queue;
 628
 629         queue = instance_lookup(queue_num);
 630         if (!queue)
 631                 return ERR_PTR(-ENODEV);
 632
 633         if (queue->peer_pid != nlpid)
 634                 return ERR_PTR(-EPERM);
 635
 636         return queue;
 637 }
 638
 639 static struct nfqnl_msg_verdict_hdr*
 640 verdicthdr_get(const struct nlattr * const nfqa[])
 641 {
 642         struct nfqnl_msg_verdict_hdr *vhdr;
 643         unsigned int verdict;
 644
 645         if (!nfqa[NFQA_VERDICT_HDR])
 646                 return NULL;
 647
 648         vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
 649         verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK;
 650         if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN)
 651                 return NULL;
 652         return vhdr;
 653 }
 654
 655 static int nfq_id_after(unsigned int id, unsigned int max)
 656 {
 657         return (int)(id - max) > 0;
 658 }
 659
 660 static int
 661 nfqnl_recv_verdict_batch(struct sock *ctnl, struct sk_buff *skb,
 662                    const struct nlmsghdr *nlh,
 663                    const struct nlattr * const nfqa[])
 664 {
 665         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 666         struct nf_queue_entry *entry, *tmp;
 667         unsigned int verdict, maxid;
 668         struct nfqnl_msg_verdict_hdr *vhdr;
 669         struct nfqnl_instance *queue;
 670         LIST_HEAD(batch_list);
 671         u16 queue_num = ntohs(nfmsg->res_id);
 672
 673         queue = verdict_instance_lookup(queue_num, NETLINK_CB(skb).pid);
 674         if (IS_ERR(queue))
 675                 return PTR_ERR(queue);
 676
 677         vhdr = verdicthdr_get(nfqa);
 678         if (!vhdr)
 679                 return -EINVAL;
 680
 681         verdict = ntohl(vhdr->verdict);
 682         maxid = ntohl(vhdr->id);
 683
 684         spin_lock_bh(&queue->lock);
 685
 686         list_for_each_entry_safe(entry, tmp, &queue->queue_list, list) {
 687                 if (nfq_id_after(entry->id, maxid))
 688                         break;
 689                 __dequeue_entry(queue, entry);
 690                 list_add_tail(&entry->list, &batch_list);
 691         }
 692
 693         spin_unlock_bh(&queue->lock);
 694
 695         if (list_empty(&batch_list))
 696                 return -ENOENT;
 697
 698         list_for_each_entry_safe(entry, tmp, &batch_list, list) {
 699                 if (nfqa[NFQA_MARK])
 700                         entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
 701                 nf_reinject(entry, verdict);
 702         }
 703         return 0;
 704 }
 705
 706 static int
 707 nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
 708                    const struct nlmsghdr *nlh,
 709                    const struct nlattr * const nfqa[])
 710 {
 711         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 712         u_int16_t queue_num = ntohs(nfmsg->res_id);
 713
 714         struct nfqnl_msg_verdict_hdr *vhdr;
 715         struct nfqnl_instance *queue;
 716         unsigned int verdict;
 717         struct nf_queue_entry *entry;
 718
 719         queue = instance_lookup(queue_num);
 720         if (!queue)
 721
 722         queue = verdict_instance_lookup(queue_num, NETLINK_CB(skb).pid);
 723         if (IS_ERR(queue))
 724                 return PTR_ERR(queue);
 725
 726         vhdr = verdicthdr_get(nfqa);
 727         if (!vhdr)
 728                 return -EINVAL;
 729
 730         verdict = ntohl(vhdr->verdict);
 731
 732         entry = find_dequeue_entry(queue, ntohl(vhdr->id));
 733         if (entry == NULL)
 734                 return -ENOENT;
 735
 736         if (nfqa[NFQA_PAYLOAD]) {
 737                 if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
 738                                  nla_len(nfqa[NFQA_PAYLOAD]), entry) < 0)
 739                         verdict = NF_DROP;
 740         }
 741
 742         if (nfqa[NFQA_MARK])
 743                 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
 744
 745         nf_reinject(entry, verdict);
 746         return 0;
 747 }
 748
 749 static int
 750 nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
 751                   const struct nlmsghdr *nlh,
 752                   const struct nlattr * const nfqa[])
 753 {
 754         return -ENOTSUPP;
 755 }
 756
 757 static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
 758         [NFQA_CFG_CMD]          = { .len = sizeof(struct nfqnl_msg_config_cmd) },
 759         [NFQA_CFG_PARAMS]       = { .len = sizeof(struct nfqnl_msg_config_params) },
 760 };
 761
 762 static const struct nf_queue_handler nfqh = {
 763         .name   = "nf_queue",
 764         .outfn  = &nfqnl_enqueue_packet,
 765 };
 766
 767 static int
 768 nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 769                   const struct nlmsghdr *nlh,
 770                   const struct nlattr * const nfqa[])
 771 {
 772         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 773         u_int16_t queue_num = ntohs(nfmsg->res_id);
 774         struct nfqnl_instance *queue;
 775         struct nfqnl_msg_config_cmd *cmd = NULL;
 776         int ret = 0;
 777
 778         if (nfqa[NFQA_CFG_CMD]) {
 779                 cmd = nla_data(nfqa[NFQA_CFG_CMD]);
 780
 781                 /* Commands without queue context - might sleep */
 782                 switch (cmd->command) {
 783                 case NFQNL_CFG_CMD_PF_BIND:
 784                         return nf_register_queue_handler(ntohs(cmd->pf),
 785                                                          &nfqh);
 786                 case NFQNL_CFG_CMD_PF_UNBIND:
 787                         return nf_unregister_queue_handler(ntohs(cmd->pf),
 788                                                            &nfqh);
 789                 }
 790         }
 791
 792         rcu_read_lock();
 793         queue = instance_lookup(queue_num);
 794         if (queue && queue->peer_pid != NETLINK_CB(skb).pid) {
 795                 ret = -EPERM;
 796                 goto err_out_unlock;
 797         }
 798
 799         if (cmd != NULL) {
 800                 switch (cmd->command) {
 801                 case NFQNL_CFG_CMD_BIND:
 802                         if (queue) {
 803                                 ret = -EBUSY;
 804                                 goto err_out_unlock;
 805                         }
 806                         queue = instance_create(queue_num, NETLINK_CB(skb).pid);
 807                         if (IS_ERR(queue)) {
 808                                 ret = PTR_ERR(queue);
 809                                 goto err_out_unlock;
 810                         }
 811                         break;
 812                 case NFQNL_CFG_CMD_UNBIND:
 813                         if (!queue) {
 814                                 ret = -ENODEV;
 815                                 goto err_out_unlock;
 816                         }
 817                         instance_destroy(queue);
 818                         break;
 819                 case NFQNL_CFG_CMD_PF_BIND:
 820                 case NFQNL_CFG_CMD_PF_UNBIND:
 821                         break;
 822                 default:
 823                         ret = -ENOTSUPP;
 824                         break;
 825                 }
 826         }
 827
 828         if (nfqa[NFQA_CFG_PARAMS]) {
 829                 struct nfqnl_msg_config_params *params;
 830
 831                 if (!queue) {
 832                         ret = -ENODEV;
 833                         goto err_out_unlock;
 834                 }
 835                 params = nla_data(nfqa[NFQA_CFG_PARAMS]);
 836                 nfqnl_set_mode(queue, params->copy_mode,
 837                                 ntohl(params->copy_range));
 838         }
 839
 840         if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
 841                 __be32 *queue_maxlen;
 842
 843                 if (!queue) {
 844                         ret = -ENODEV;
 845                         goto err_out_unlock;
 846                 }
 847                 queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
 848                 spin_lock_bh(&queue->lock);
 849                 queue->queue_maxlen = ntohl(*queue_maxlen);
 850                 spin_unlock_bh(&queue->lock);
 851         }
 852
 853 err_out_unlock:
 854         rcu_read_unlock();
 855         return ret;
 856 }
 857
 858 static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
 859         [NFQNL_MSG_PACKET]      = { .call_rcu = nfqnl_recv_unsupp,
 860                                     .attr_count = NFQA_MAX, },
 861         [NFQNL_MSG_VERDICT]     = { .call_rcu = nfqnl_recv_verdict,
 862                                     .attr_count = NFQA_MAX,
 863                                     .policy = nfqa_verdict_policy },
 864         [NFQNL_MSG_CONFIG]      = { .call = nfqnl_recv_config,
 865                                     .attr_count = NFQA_CFG_MAX,
 866                                     .policy = nfqa_cfg_policy },
 867         [NFQNL_MSG_VERDICT_BATCH]={ .call_rcu = nfqnl_recv_verdict_batch,
 868                                     .attr_count = NFQA_MAX,
 869                                     .policy = nfqa_verdict_batch_policy },
 870 };
 871
 872 static const struct nfnetlink_subsystem nfqnl_subsys = {
 873         .name           = "nf_queue",
 874         .subsys_id      = NFNL_SUBSYS_QUEUE,
 875         .cb_count       = NFQNL_MSG_MAX,
 876         .cb             = nfqnl_cb,
 877 };
 878
 879 #ifdef CONFIG_PROC_FS
 880 struct iter_state {
 881         unsigned int bucket;
 882 };
 883
 884 static struct hlist_node *get_first(struct seq_file *seq)
 885 {
 886         struct iter_state *st = seq->private;
 887
 888         if (!st)
 889                 return NULL;
 890
 891         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
 892                 if (!hlist_empty(&instance_table[st->bucket]))
 893                         return instance_table[st->bucket].first;
 894         }
 895         return NULL;
 896 }
 897
 898 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
 899 {
 900         struct iter_state *st = seq->private;
 901
 902         h = h->next;
 903         while (!h) {
 904                 if (++st->bucket >= INSTANCE_BUCKETS)
 905                         return NULL;
 906
 907                 h = instance_table[st->bucket].first;
 908         }
 909         return h;
 910 }
 911
 912 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
 913 {
 914         struct hlist_node *head;
 915         head = get_first(seq);
 916
 917         if (head)
 918                 while (pos && (head = get_next(seq, head)))
 919                         pos--;
 920         return pos ? NULL : head;
 921 }
 922
 923 static void *seq_start(struct seq_file *seq, loff_t *pos)
 924         __acquires(instances_lock)
 925 {
 926         spin_lock(&instances_lock);
 927         return get_idx(seq, *pos);
 928 }
 929
 930 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
 931 {
 932         (*pos)++;
 933         return get_next(s, v);
 934 }
 935
 936 static void seq_stop(struct seq_file *s, void *v)
 937         __releases(instances_lock)
 938 {
 939         spin_unlock(&instances_lock);
 940 }
 941
 942 static int seq_show(struct seq_file *s, void *v)
 943 {
 944         const struct nfqnl_instance *inst = v;
 945
 946         return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n",
 947                           inst->queue_num,
 948                           inst->peer_pid, inst->queue_total,
 949                           inst->copy_mode, inst->copy_range,
 950                           inst->queue_dropped, inst->queue_user_dropped,
 951                           inst->id_sequence, 1);
 952 }
 953
 954 static const struct seq_operations nfqnl_seq_ops = {
 955         .start  = seq_start,
 956         .next   = seq_next,
 957         .stop   = seq_stop,
 958         .show   = seq_show,
 959 };
 960
 961 static int nfqnl_open(struct inode *inode, struct file *file)
 962 {
 963         return seq_open_private(file, &nfqnl_seq_ops,
 964                         sizeof(struct iter_state));
 965 }
 966
 967 static const struct file_operations nfqnl_file_ops = {
 968         .owner   = THIS_MODULE,
 969         .open    = nfqnl_open,
 970         .read    = seq_read,
 971         .llseek  = seq_lseek,
 972         .release = seq_release_private,
 973 };
 974
 975 #endif /* PROC_FS */
 976
 977 static int __init nfnetlink_queue_init(void)
 978 {
 979         int i, status = -ENOMEM;
 980
 981         for (i = 0; i < INSTANCE_BUCKETS; i++)
 982                 INIT_HLIST_HEAD(&instance_table[i]);
 983
 984         netlink_register_notifier(&nfqnl_rtnl_notifier);
 985         status = nfnetlink_subsys_register(&nfqnl_subsys);
 986         if (status < 0) {
 987                 printk(KERN_ERR "nf_queue: failed to create netlink socket\n");
 988                 goto cleanup_netlink_notifier;
 989         }
 990
 991 #ifdef CONFIG_PROC_FS
 992         if (!proc_create("nfnetlink_queue", 0440,
 993                          proc_net_netfilter, &nfqnl_file_ops))
 994                 goto cleanup_subsys;
 995 #endif
 996
 997         register_netdevice_notifier(&nfqnl_dev_notifier);
 998         return status;
 999
1000 #ifdef CONFIG_PROC_FS
1001 cleanup_subsys:
1002         nfnetlink_subsys_unregister(&nfqnl_subsys);
1003 #endif
1004 cleanup_netlink_notifier:
1005         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1006         return status;
1007 }
1008
1009 static void __exit nfnetlink_queue_fini(void)
1010 {
1011         nf_unregister_queue_handlers(&nfqh);
1012         unregister_netdevice_notifier(&nfqnl_dev_notifier);
1013 #ifdef CONFIG_PROC_FS
1014         remove_proc_entry("nfnetlink_queue", proc_net_netfilter);
1015 #endif
1016         nfnetlink_subsys_unregister(&nfqnl_subsys);
1017         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1018
1019         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1020 }
1021
1022 MODULE_DESCRIPTION("netfilter packet queue handler");
1023 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1024 MODULE_LICENSE("GPL");
1025 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1026
1027 module_init(nfnetlink_queue_init);
1028 module_exit(nfnetlink_queue_fini);