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