net/netfilter/nfnetlink_queue_core.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 #include <net/netfilter/nfnetlink_queue.h>
  34
  35 #include <linux/atomic.h>
  36
  37 #ifdef CONFIG_BRIDGE_NETFILTER
  38 #include "../bridge/br_private.h"
  39 #endif
  40
  41 #define NFQNL_QMAX_DEFAULT 1024
  42
  43 struct nfqnl_instance {
  44         struct hlist_node hlist;                /* global list of queues */
  45         struct rcu_head rcu;
  46
  47         int peer_portid;
  48         unsigned int queue_maxlen;
  49         unsigned int copy_range;
  50         unsigned int queue_dropped;
  51         unsigned int queue_user_dropped;
  52
  53
  54         u_int16_t queue_num;                    /* number of this queue */
  55         u_int8_t copy_mode;
  56         u_int32_t flags;                        /* Set using NFQA_CFG_FLAGS */
  57 /*
  58  * Following fields are dirtied for each queued packet,
  59  * keep them in same cache line if possible.
  60  */
  61         spinlock_t      lock;
  62         unsigned int    queue_total;
  63         unsigned int    id_sequence;            /* 'sequence' of pkt ids */
  64         struct list_head queue_list;            /* packets in queue */
  65 };
  66
  67 typedef int (*nfqnl_cmpfn)(struct nf_queue_entry *, unsigned long);
  68
  69 static DEFINE_SPINLOCK(instances_lock);
  70
  71 #define INSTANCE_BUCKETS        16
  72 static struct hlist_head instance_table[INSTANCE_BUCKETS] __read_mostly;
  73
  74 static inline u_int8_t instance_hashfn(u_int16_t queue_num)
  75 {
  76         return ((queue_num >> 8) ^ queue_num) % INSTANCE_BUCKETS;
  77 }
  78
  79 static struct nfqnl_instance *
  80 instance_lookup(u_int16_t queue_num)
  81 {
  82         struct hlist_head *head;
  83         struct nfqnl_instance *inst;
  84
  85         head = &instance_table[instance_hashfn(queue_num)];
  86         hlist_for_each_entry_rcu(inst, head, hlist) {
  87                 if (inst->queue_num == queue_num)
  88                         return inst;
  89         }
  90         return NULL;
  91 }
  92
  93 static struct nfqnl_instance *
  94 instance_create(u_int16_t queue_num, int portid)
  95 {
  96         struct nfqnl_instance *inst;
  97         unsigned int h;
  98         int err;
  99
 100         spin_lock(&instances_lock);
 101         if (instance_lookup(queue_num)) {
 102                 err = -EEXIST;
 103                 goto out_unlock;
 104         }
 105
 106         inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
 107         if (!inst) {
 108                 err = -ENOMEM;
 109                 goto out_unlock;
 110         }
 111
 112         inst->queue_num = queue_num;
 113         inst->peer_portid = portid;
 114         inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
 115         inst->copy_range = 0xffff;
 116         inst->copy_mode = NFQNL_COPY_NONE;
 117         spin_lock_init(&inst->lock);
 118         INIT_LIST_HEAD(&inst->queue_list);
 119
 120         if (!try_module_get(THIS_MODULE)) {
 121                 err = -EAGAIN;
 122                 goto out_free;
 123         }
 124
 125         h = instance_hashfn(queue_num);
 126         hlist_add_head_rcu(&inst->hlist, &instance_table[h]);
 127
 128         spin_unlock(&instances_lock);
 129
 130         return inst;
 131
 132 out_free:
 133         kfree(inst);
 134 out_unlock:
 135         spin_unlock(&instances_lock);
 136         return ERR_PTR(err);
 137 }
 138
 139 static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
 140                         unsigned long data);
 141
 142 static void
 143 instance_destroy_rcu(struct rcu_head *head)
 144 {
 145         struct nfqnl_instance *inst = container_of(head, struct nfqnl_instance,
 146                                                    rcu);
 147
 148         nfqnl_flush(inst, NULL, 0);
 149         kfree(inst);
 150         module_put(THIS_MODULE);
 151 }
 152
 153 static void
 154 __instance_destroy(struct nfqnl_instance *inst)
 155 {
 156         hlist_del_rcu(&inst->hlist);
 157         call_rcu(&inst->rcu, instance_destroy_rcu);
 158 }
 159
 160 static void
 161 instance_destroy(struct nfqnl_instance *inst)
 162 {
 163         spin_lock(&instances_lock);
 164         __instance_destroy(inst);
 165         spin_unlock(&instances_lock);
 166 }
 167
 168 static inline void
 169 __enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
 170 {
 171        list_add_tail(&entry->list, &queue->queue_list);
 172        queue->queue_total++;
 173 }
 174
 175 static void
 176 __dequeue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
 177 {
 178         list_del(&entry->list);
 179         queue->queue_total--;
 180 }
 181
 182 static struct nf_queue_entry *
 183 find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id)
 184 {
 185         struct nf_queue_entry *entry = NULL, *i;
 186
 187         spin_lock_bh(&queue->lock);
 188
 189         list_for_each_entry(i, &queue->queue_list, list) {
 190                 if (i->id == id) {
 191                         entry = i;
 192                         break;
 193                 }
 194         }
 195
 196         if (entry)
 197                 __dequeue_entry(queue, entry);
 198
 199         spin_unlock_bh(&queue->lock);
 200
 201         return entry;
 202 }
 203
 204 static void
 205 nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data)
 206 {
 207         struct nf_queue_entry *entry, *next;
 208
 209         spin_lock_bh(&queue->lock);
 210         list_for_each_entry_safe(entry, next, &queue->queue_list, list) {
 211                 if (!cmpfn || cmpfn(entry, data)) {
 212                         list_del(&entry->list);
 213                         queue->queue_total--;
 214                         nf_reinject(entry, NF_DROP);
 215                 }
 216         }
 217         spin_unlock_bh(&queue->lock);
 218 }
 219
 220 static void
 221 nfqnl_zcopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen)
 222 {
 223         int i, j = 0;
 224         int plen = 0; /* length of skb->head fragment */
 225         struct page *page;
 226         unsigned int offset;
 227
 228         /* dont bother with small payloads */
 229         if (len <= skb_tailroom(to)) {
 230                 skb_copy_bits(from, 0, skb_put(to, len), len);
 231                 return;
 232         }
 233
 234         if (hlen) {
 235                 skb_copy_bits(from, 0, skb_put(to, hlen), hlen);
 236                 len -= hlen;
 237         } else {
 238                 plen = min_t(int, skb_headlen(from), len);
 239                 if (plen) {
 240                         page = virt_to_head_page(from->head);
 241                         offset = from->data - (unsigned char *)page_address(page);
 242                         __skb_fill_page_desc(to, 0, page, offset, plen);
 243                         get_page(page);
 244                         j = 1;
 245                         len -= plen;
 246                 }
 247         }
 248
 249         to->truesize += len + plen;
 250         to->len += len + plen;
 251         to->data_len += len + plen;
 252
 253         for (i = 0; i < skb_shinfo(from)->nr_frags; i++) {
 254                 if (!len)
 255                         break;
 256                 skb_shinfo(to)->frags[j] = skb_shinfo(from)->frags[i];
 257                 skb_shinfo(to)->frags[j].size = min_t(int, skb_shinfo(to)->frags[j].size, len);
 258                 len -= skb_shinfo(to)->frags[j].size;
 259                 skb_frag_ref(to, j);
 260                 j++;
 261         }
 262         skb_shinfo(to)->nr_frags = j;
 263 }
 264
 265 static struct sk_buff *
 266 nfqnl_build_packet_message(struct nfqnl_instance *queue,
 267                            struct nf_queue_entry *entry,
 268                            __be32 **packet_id_ptr)
 269 {
 270         size_t size;
 271         size_t data_len = 0, cap_len = 0;
 272         int hlen = 0;
 273         struct sk_buff *skb;
 274         struct nlattr *nla;
 275         struct nfqnl_msg_packet_hdr *pmsg;
 276         struct nlmsghdr *nlh;
 277         struct nfgenmsg *nfmsg;
 278         struct sk_buff *entskb = entry->skb;
 279         struct net_device *indev;
 280         struct net_device *outdev;
 281         struct nf_conn *ct = NULL;
 282         enum ip_conntrack_info uninitialized_var(ctinfo);
 283
 284         size =    nlmsg_total_size(sizeof(struct nfgenmsg))
 285                 + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
 286                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 287                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 288 #ifdef CONFIG_BRIDGE_NETFILTER
 289                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 290                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 291 #endif
 292                 + nla_total_size(sizeof(u_int32_t))     /* mark */
 293                 + nla_total_size(sizeof(struct nfqnl_msg_packet_hw))
 294                 + nla_total_size(sizeof(u_int32_t));    /* cap_len */
 295
 296         if (entskb->tstamp.tv64)
 297                 size += nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp));
 298
 299         outdev = entry->outdev;
 300
 301         switch ((enum nfqnl_config_mode)ACCESS_ONCE(queue->copy_mode)) {
 302         case NFQNL_COPY_META:
 303         case NFQNL_COPY_NONE:
 304                 break;
 305
 306         case NFQNL_COPY_PACKET:
 307                 if (entskb->ip_summed == CHECKSUM_PARTIAL &&
 308                     skb_checksum_help(entskb))
 309                         return NULL;
 310
 311                 data_len = ACCESS_ONCE(queue->copy_range);
 312                 if (data_len == 0 || data_len > entskb->len)
 313                         data_len = entskb->len;
 314
 315
 316                 if (!entskb->head_frag ||
 317                     skb_headlen(entskb) < L1_CACHE_BYTES ||
 318                     skb_shinfo(entskb)->nr_frags >= MAX_SKB_FRAGS)
 319                         hlen = skb_headlen(entskb);
 320
 321                 if (skb_has_frag_list(entskb))
 322                         hlen = entskb->len;
 323                 hlen = min_t(int, data_len, hlen);
 324                 size += sizeof(struct nlattr) + hlen;
 325                 cap_len = entskb->len;
 326                 break;
 327         }
 328
 329         if (queue->flags & NFQA_CFG_F_CONNTRACK)
 330                 ct = nfqnl_ct_get(entskb, &size, &ctinfo);
 331
 332         skb = alloc_skb(size, GFP_ATOMIC);
 333         if (!skb)
 334                 return NULL;
 335
 336         nlh = nlmsg_put(skb, 0, 0,
 337                         NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET,
 338                         sizeof(struct nfgenmsg), 0);
 339         if (!nlh) {
 340                 kfree_skb(skb);
 341                 return NULL;
 342         }
 343         nfmsg = nlmsg_data(nlh);
 344         nfmsg->nfgen_family = entry->pf;
 345         nfmsg->version = NFNETLINK_V0;
 346         nfmsg->res_id = htons(queue->queue_num);
 347
 348         nla = __nla_reserve(skb, NFQA_PACKET_HDR, sizeof(*pmsg));
 349         pmsg = nla_data(nla);
 350         pmsg->hw_protocol       = entskb->protocol;
 351         pmsg->hook              = entry->hook;
 352         *packet_id_ptr          = &pmsg->packet_id;
 353
 354         indev = entry->indev;
 355         if (indev) {
 356 #ifndef CONFIG_BRIDGE_NETFILTER
 357                 if (nla_put_be32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex)))
 358                         goto nla_put_failure;
 359 #else
 360                 if (entry->pf == PF_BRIDGE) {
 361                         /* Case 1: indev is physical input device, we need to
 362                          * look for bridge group (when called from
 363                          * netfilter_bridge) */
 364                         if (nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
 365                                          htonl(indev->ifindex)) ||
 366                         /* this is the bridge group "brX" */
 367                         /* rcu_read_lock()ed by __nf_queue */
 368                             nla_put_be32(skb, NFQA_IFINDEX_INDEV,
 369                                          htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
 370                                 goto nla_put_failure;
 371                 } else {
 372                         /* Case 2: indev is bridge group, we need to look for
 373                          * physical device (when called from ipv4) */
 374                         if (nla_put_be32(skb, NFQA_IFINDEX_INDEV,
 375                                          htonl(indev->ifindex)))
 376                                 goto nla_put_failure;
 377                         if (entskb->nf_bridge && entskb->nf_bridge->physindev &&
 378                             nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
 379                                          htonl(entskb->nf_bridge->physindev->ifindex)))
 380                                 goto nla_put_failure;
 381                 }
 382 #endif
 383         }
 384
 385         if (outdev) {
 386 #ifndef CONFIG_BRIDGE_NETFILTER
 387                 if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex)))
 388                         goto nla_put_failure;
 389 #else
 390                 if (entry->pf == PF_BRIDGE) {
 391                         /* Case 1: outdev is physical output device, we need to
 392                          * look for bridge group (when called from
 393                          * netfilter_bridge) */
 394                         if (nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
 395                                          htonl(outdev->ifindex)) ||
 396                         /* this is the bridge group "brX" */
 397                         /* rcu_read_lock()ed by __nf_queue */
 398                             nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
 399                                          htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
 400                                 goto nla_put_failure;
 401                 } else {
 402                         /* Case 2: outdev is bridge group, we need to look for
 403                          * physical output device (when called from ipv4) */
 404                         if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
 405                                          htonl(outdev->ifindex)))
 406                                 goto nla_put_failure;
 407                         if (entskb->nf_bridge && entskb->nf_bridge->physoutdev &&
 408                             nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
 409                                          htonl(entskb->nf_bridge->physoutdev->ifindex)))
 410                                 goto nla_put_failure;
 411                 }
 412 #endif
 413         }
 414
 415         if (entskb->mark &&
 416             nla_put_be32(skb, NFQA_MARK, htonl(entskb->mark)))
 417                 goto nla_put_failure;
 418
 419         if (indev && entskb->dev &&
 420             entskb->mac_header != entskb->network_header) {
 421                 struct nfqnl_msg_packet_hw phw;
 422                 int len = dev_parse_header(entskb, phw.hw_addr);
 423                 if (len) {
 424                         phw.hw_addrlen = htons(len);
 425                         if (nla_put(skb, NFQA_HWADDR, sizeof(phw), &phw))
 426                                 goto nla_put_failure;
 427                 }
 428         }
 429
 430         if (entskb->tstamp.tv64) {
 431                 struct nfqnl_msg_packet_timestamp ts;
 432                 struct timeval tv = ktime_to_timeval(entskb->tstamp);
 433                 ts.sec = cpu_to_be64(tv.tv_sec);
 434                 ts.usec = cpu_to_be64(tv.tv_usec);
 435
 436                 if (nla_put(skb, NFQA_TIMESTAMP, sizeof(ts), &ts))
 437                         goto nla_put_failure;
 438         }
 439
 440         if (ct && nfqnl_ct_put(skb, ct, ctinfo) < 0)
 441                 goto nla_put_failure;
 442
 443         if (cap_len > 0 && nla_put_be32(skb, NFQA_CAP_LEN, htonl(cap_len)))
 444                 goto nla_put_failure;
 445
 446         if (data_len) {
 447                 struct nlattr *nla;
 448
 449                 if (skb_tailroom(skb) < sizeof(*nla) + hlen)
 450                         goto nla_put_failure;
 451
 452                 nla = (struct nlattr *)skb_put(skb, sizeof(*nla));
 453                 nla->nla_type = NFQA_PAYLOAD;
 454                 nla->nla_len = nla_attr_size(data_len);
 455
 456                 nfqnl_zcopy(skb, entskb, data_len, hlen);
 457         }
 458
 459         nlh->nlmsg_len = skb->len;
 460         return skb;
 461
 462 nla_put_failure:
 463         kfree_skb(skb);
 464         net_err_ratelimited("nf_queue: error creating packet message\n");
 465         return NULL;
 466 }
 467
 468 static int
 469 nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
 470 {
 471         struct sk_buff *nskb;
 472         struct nfqnl_instance *queue;
 473         int err = -ENOBUFS;
 474         __be32 *packet_id_ptr;
 475         int failopen = 0;
 476
 477         /* rcu_read_lock()ed by nf_hook_slow() */
 478         queue = instance_lookup(queuenum);
 479         if (!queue) {
 480                 err = -ESRCH;
 481                 goto err_out;
 482         }
 483
 484         if (queue->copy_mode == NFQNL_COPY_NONE) {
 485                 err = -EINVAL;
 486                 goto err_out;
 487         }
 488
 489         nskb = nfqnl_build_packet_message(queue, entry, &packet_id_ptr);
 490         if (nskb == NULL) {
 491                 err = -ENOMEM;
 492                 goto err_out;
 493         }
 494         spin_lock_bh(&queue->lock);
 495
 496         if (!queue->peer_portid) {
 497                 err = -EINVAL;
 498                 goto err_out_free_nskb;
 499         }
 500         if (queue->queue_total >= queue->queue_maxlen) {
 501                 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
 502                         failopen = 1;
 503                         err = 0;
 504                 } else {
 505                         queue->queue_dropped++;
 506                         net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n",
 507                                              queue->queue_total);
 508                 }
 509                 goto err_out_free_nskb;
 510         }
 511         entry->id = ++queue->id_sequence;
 512         *packet_id_ptr = htonl(entry->id);
 513
 514         /* nfnetlink_unicast will either free the nskb or add it to a socket */
 515         err = nfnetlink_unicast(nskb, &init_net, queue->peer_portid, MSG_DONTWAIT);
 516         if (err < 0) {
 517                 queue->queue_user_dropped++;
 518                 goto err_out_unlock;
 519         }
 520
 521         __enqueue_entry(queue, entry);
 522
 523         spin_unlock_bh(&queue->lock);
 524         return 0;
 525
 526 err_out_free_nskb:
 527         kfree_skb(nskb);
 528 err_out_unlock:
 529         spin_unlock_bh(&queue->lock);
 530         if (failopen)
 531                 nf_reinject(entry, NF_ACCEPT);
 532 err_out:
 533         return err;
 534 }
 535
 536 static int
 537 nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e, int diff)
 538 {
 539         struct sk_buff *nskb;
 540
 541         if (diff < 0) {
 542                 if (pskb_trim(e->skb, data_len))
 543                         return -ENOMEM;
 544         } else if (diff > 0) {
 545                 if (data_len > 0xFFFF)
 546                         return -EINVAL;
 547                 if (diff > skb_tailroom(e->skb)) {
 548                         nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
 549                                                diff, GFP_ATOMIC);
 550                         if (!nskb) {
 551                                 printk(KERN_WARNING "nf_queue: OOM "
 552                                       "in mangle, dropping packet\n");
 553                                 return -ENOMEM;
 554                         }
 555                         kfree_skb(e->skb);
 556                         e->skb = nskb;
 557                 }
 558                 skb_put(e->skb, diff);
 559         }
 560         if (!skb_make_writable(e->skb, data_len))
 561                 return -ENOMEM;
 562         skb_copy_to_linear_data(e->skb, data, data_len);
 563         e->skb->ip_summed = CHECKSUM_NONE;
 564         return 0;
 565 }
 566
 567 static int
 568 nfqnl_set_mode(struct nfqnl_instance *queue,
 569                unsigned char mode, unsigned int range)
 570 {
 571         int status = 0;
 572
 573         spin_lock_bh(&queue->lock);
 574         switch (mode) {
 575         case NFQNL_COPY_NONE:
 576         case NFQNL_COPY_META:
 577                 queue->copy_mode = mode;
 578                 queue->copy_range = 0;
 579                 break;
 580
 581         case NFQNL_COPY_PACKET:
 582                 queue->copy_mode = mode;
 583                 /* We're using struct nlattr which has 16bit nla_len. Note that
 584                  * nla_len includes the header length. Thus, the maximum packet
 585                  * length that we support is 65531 bytes. We send truncated
 586                  * packets if the specified length is larger than that.
 587                  */
 588                 if (range > 0xffff - NLA_HDRLEN)
 589                         queue->copy_range = 0xffff - NLA_HDRLEN;
 590                 else
 591                         queue->copy_range = range;
 592                 break;
 593
 594         default:
 595                 status = -EINVAL;
 596
 597         }
 598         spin_unlock_bh(&queue->lock);
 599
 600         return status;
 601 }
 602
 603 static int
 604 dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
 605 {
 606         if (entry->indev)
 607                 if (entry->indev->ifindex == ifindex)
 608                         return 1;
 609         if (entry->outdev)
 610                 if (entry->outdev->ifindex == ifindex)
 611                         return 1;
 612 #ifdef CONFIG_BRIDGE_NETFILTER
 613         if (entry->skb->nf_bridge) {
 614                 if (entry->skb->nf_bridge->physindev &&
 615                     entry->skb->nf_bridge->physindev->ifindex == ifindex)
 616                         return 1;
 617                 if (entry->skb->nf_bridge->physoutdev &&
 618                     entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
 619                         return 1;
 620         }
 621 #endif
 622         return 0;
 623 }
 624
 625 /* drop all packets with either indev or outdev == ifindex from all queue
 626  * instances */
 627 static void
 628 nfqnl_dev_drop(int ifindex)
 629 {
 630         int i;
 631
 632         rcu_read_lock();
 633
 634         for (i = 0; i < INSTANCE_BUCKETS; i++) {
 635                 struct nfqnl_instance *inst;
 636                 struct hlist_head *head = &instance_table[i];
 637
 638                 hlist_for_each_entry_rcu(inst, head, hlist)
 639                         nfqnl_flush(inst, dev_cmp, ifindex);
 640         }
 641
 642         rcu_read_unlock();
 643 }
 644
 645 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 646
 647 static int
 648 nfqnl_rcv_dev_event(struct notifier_block *this,
 649                     unsigned long event, void *ptr)
 650 {
 651         struct net_device *dev = ptr;
 652
 653         if (!net_eq(dev_net(dev), &init_net))
 654                 return NOTIFY_DONE;
 655
 656         /* Drop any packets associated with the downed device */
 657         if (event == NETDEV_DOWN)
 658                 nfqnl_dev_drop(dev->ifindex);
 659         return NOTIFY_DONE;
 660 }
 661
 662 static struct notifier_block nfqnl_dev_notifier = {
 663         .notifier_call  = nfqnl_rcv_dev_event,
 664 };
 665
 666 static int
 667 nfqnl_rcv_nl_event(struct notifier_block *this,
 668                    unsigned long event, void *ptr)
 669 {
 670         struct netlink_notify *n = ptr;
 671
 672         if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
 673                 int i;
 674
 675                 /* destroy all instances for this portid */
 676                 spin_lock(&instances_lock);
 677                 for (i = 0; i < INSTANCE_BUCKETS; i++) {
 678                         struct hlist_node *t2;
 679                         struct nfqnl_instance *inst;
 680                         struct hlist_head *head = &instance_table[i];
 681
 682                         hlist_for_each_entry_safe(inst, t2, head, hlist) {
 683                                 if ((n->net == &init_net) &&
 684                                     (n->portid == inst->peer_portid))
 685                                         __instance_destroy(inst);
 686                         }
 687                 }
 688                 spin_unlock(&instances_lock);
 689         }
 690         return NOTIFY_DONE;
 691 }
 692
 693 static struct notifier_block nfqnl_rtnl_notifier = {
 694         .notifier_call  = nfqnl_rcv_nl_event,
 695 };
 696
 697 static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = {
 698         [NFQA_VERDICT_HDR]      = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
 699         [NFQA_MARK]             = { .type = NLA_U32 },
 700         [NFQA_PAYLOAD]          = { .type = NLA_UNSPEC },
 701         [NFQA_CT]               = { .type = NLA_UNSPEC },
 702 };
 703
 704 static const struct nla_policy nfqa_verdict_batch_policy[NFQA_MAX+1] = {
 705         [NFQA_VERDICT_HDR]      = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
 706         [NFQA_MARK]             = { .type = NLA_U32 },
 707 };
 708
 709 static struct nfqnl_instance *verdict_instance_lookup(u16 queue_num, int nlportid)
 710 {
 711         struct nfqnl_instance *queue;
 712
 713         queue = instance_lookup(queue_num);
 714         if (!queue)
 715                 return ERR_PTR(-ENODEV);
 716
 717         if (queue->peer_portid != nlportid)
 718                 return ERR_PTR(-EPERM);
 719
 720         return queue;
 721 }
 722
 723 static struct nfqnl_msg_verdict_hdr*
 724 verdicthdr_get(const struct nlattr * const nfqa[])
 725 {
 726         struct nfqnl_msg_verdict_hdr *vhdr;
 727         unsigned int verdict;
 728
 729         if (!nfqa[NFQA_VERDICT_HDR])
 730                 return NULL;
 731
 732         vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
 733         verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK;
 734         if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN)
 735                 return NULL;
 736         return vhdr;
 737 }
 738
 739 static int nfq_id_after(unsigned int id, unsigned int max)
 740 {
 741         return (int)(id - max) > 0;
 742 }
 743
 744 static int
 745 nfqnl_recv_verdict_batch(struct sock *ctnl, struct sk_buff *skb,
 746                    const struct nlmsghdr *nlh,
 747                    const struct nlattr * const nfqa[])
 748 {
 749         struct nfgenmsg *nfmsg = nlmsg_data(nlh);
 750         struct nf_queue_entry *entry, *tmp;
 751         unsigned int verdict, maxid;
 752         struct nfqnl_msg_verdict_hdr *vhdr;
 753         struct nfqnl_instance *queue;
 754         LIST_HEAD(batch_list);
 755         u16 queue_num = ntohs(nfmsg->res_id);
 756
 757         queue = verdict_instance_lookup(queue_num, NETLINK_CB(skb).portid);
 758         if (IS_ERR(queue))
 759                 return PTR_ERR(queue);
 760
 761         vhdr = verdicthdr_get(nfqa);
 762         if (!vhdr)
 763                 return -EINVAL;
 764
 765         verdict = ntohl(vhdr->verdict);
 766         maxid = ntohl(vhdr->id);
 767
 768         spin_lock_bh(&queue->lock);
 769
 770         list_for_each_entry_safe(entry, tmp, &queue->queue_list, list) {
 771                 if (nfq_id_after(entry->id, maxid))
 772                         break;
 773                 __dequeue_entry(queue, entry);
 774                 list_add_tail(&entry->list, &batch_list);
 775         }
 776
 777         spin_unlock_bh(&queue->lock);
 778
 779         if (list_empty(&batch_list))
 780                 return -ENOENT;
 781
 782         list_for_each_entry_safe(entry, tmp, &batch_list, list) {
 783                 if (nfqa[NFQA_MARK])
 784                         entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
 785                 nf_reinject(entry, verdict);
 786         }
 787         return 0;
 788 }
 789
 790 static int
 791 nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
 792                    const struct nlmsghdr *nlh,
 793                    const struct nlattr * const nfqa[])
 794 {
 795         struct nfgenmsg *nfmsg = nlmsg_data(nlh);
 796         u_int16_t queue_num = ntohs(nfmsg->res_id);
 797
 798         struct nfqnl_msg_verdict_hdr *vhdr;
 799         struct nfqnl_instance *queue;
 800         unsigned int verdict;
 801         struct nf_queue_entry *entry;
 802         enum ip_conntrack_info uninitialized_var(ctinfo);
 803         struct nf_conn *ct = NULL;
 804
 805         queue = instance_lookup(queue_num);
 806         if (!queue)
 807
 808         queue = verdict_instance_lookup(queue_num, NETLINK_CB(skb).portid);
 809         if (IS_ERR(queue))
 810                 return PTR_ERR(queue);
 811
 812         vhdr = verdicthdr_get(nfqa);
 813         if (!vhdr)
 814                 return -EINVAL;
 815
 816         verdict = ntohl(vhdr->verdict);
 817
 818         entry = find_dequeue_entry(queue, ntohl(vhdr->id));
 819         if (entry == NULL)
 820                 return -ENOENT;
 821
 822         rcu_read_lock();
 823         if (nfqa[NFQA_CT] && (queue->flags & NFQA_CFG_F_CONNTRACK))
 824                 ct = nfqnl_ct_parse(entry->skb, nfqa[NFQA_CT], &ctinfo);
 825
 826         if (nfqa[NFQA_PAYLOAD]) {
 827                 u16 payload_len = nla_len(nfqa[NFQA_PAYLOAD]);
 828                 int diff = payload_len - entry->skb->len;
 829
 830                 if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
 831                                  payload_len, entry, diff) < 0)
 832                         verdict = NF_DROP;
 833
 834                 if (ct)
 835                         nfqnl_ct_seq_adjust(skb, ct, ctinfo, diff);
 836         }
 837         rcu_read_unlock();
 838
 839         if (nfqa[NFQA_MARK])
 840                 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
 841
 842         nf_reinject(entry, verdict);
 843         return 0;
 844 }
 845
 846 static int
 847 nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
 848                   const struct nlmsghdr *nlh,
 849                   const struct nlattr * const nfqa[])
 850 {
 851         return -ENOTSUPP;
 852 }
 853
 854 static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
 855         [NFQA_CFG_CMD]          = { .len = sizeof(struct nfqnl_msg_config_cmd) },
 856         [NFQA_CFG_PARAMS]       = { .len = sizeof(struct nfqnl_msg_config_params) },
 857 };
 858
 859 static const struct nf_queue_handler nfqh = {
 860         .outfn  = &nfqnl_enqueue_packet,
 861 };
 862
 863 static int
 864 nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 865                   const struct nlmsghdr *nlh,
 866                   const struct nlattr * const nfqa[])
 867 {
 868         struct nfgenmsg *nfmsg = nlmsg_data(nlh);
 869         u_int16_t queue_num = ntohs(nfmsg->res_id);
 870         struct nfqnl_instance *queue;
 871         struct nfqnl_msg_config_cmd *cmd = NULL;
 872         int ret = 0;
 873
 874         if (nfqa[NFQA_CFG_CMD]) {
 875                 cmd = nla_data(nfqa[NFQA_CFG_CMD]);
 876
 877                 /* Obsolete commands without queue context */
 878                 switch (cmd->command) {
 879                 case NFQNL_CFG_CMD_PF_BIND: return 0;
 880                 case NFQNL_CFG_CMD_PF_UNBIND: return 0;
 881                 }
 882         }
 883
 884         rcu_read_lock();
 885         queue = instance_lookup(queue_num);
 886         if (queue && queue->peer_portid != NETLINK_CB(skb).portid) {
 887                 ret = -EPERM;
 888                 goto err_out_unlock;
 889         }
 890
 891         if (cmd != NULL) {
 892                 switch (cmd->command) {
 893                 case NFQNL_CFG_CMD_BIND:
 894                         if (queue) {
 895                                 ret = -EBUSY;
 896                                 goto err_out_unlock;
 897                         }
 898                         queue = instance_create(queue_num, NETLINK_CB(skb).portid);
 899                         if (IS_ERR(queue)) {
 900                                 ret = PTR_ERR(queue);
 901                                 goto err_out_unlock;
 902                         }
 903                         break;
 904                 case NFQNL_CFG_CMD_UNBIND:
 905                         if (!queue) {
 906                                 ret = -ENODEV;
 907                                 goto err_out_unlock;
 908                         }
 909                         instance_destroy(queue);
 910                         break;
 911                 case NFQNL_CFG_CMD_PF_BIND:
 912                 case NFQNL_CFG_CMD_PF_UNBIND:
 913                         break;
 914                 default:
 915                         ret = -ENOTSUPP;
 916                         break;
 917                 }
 918         }
 919
 920         if (nfqa[NFQA_CFG_PARAMS]) {
 921                 struct nfqnl_msg_config_params *params;
 922
 923                 if (!queue) {
 924                         ret = -ENODEV;
 925                         goto err_out_unlock;
 926                 }
 927                 params = nla_data(nfqa[NFQA_CFG_PARAMS]);
 928                 nfqnl_set_mode(queue, params->copy_mode,
 929                                 ntohl(params->copy_range));
 930         }
 931
 932         if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
 933                 __be32 *queue_maxlen;
 934
 935                 if (!queue) {
 936                         ret = -ENODEV;
 937                         goto err_out_unlock;
 938                 }
 939                 queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
 940                 spin_lock_bh(&queue->lock);
 941                 queue->queue_maxlen = ntohl(*queue_maxlen);
 942                 spin_unlock_bh(&queue->lock);
 943         }
 944
 945         if (nfqa[NFQA_CFG_FLAGS]) {
 946                 __u32 flags, mask;
 947
 948                 if (!queue) {
 949                         ret = -ENODEV;
 950                         goto err_out_unlock;
 951                 }
 952
 953                 if (!nfqa[NFQA_CFG_MASK]) {
 954                         /* A mask is needed to specify which flags are being
 955                          * changed.
 956                          */
 957                         ret = -EINVAL;
 958                         goto err_out_unlock;
 959                 }
 960
 961                 flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS]));
 962                 mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK]));
 963
 964                 if (flags >= NFQA_CFG_F_MAX) {
 965                         ret = -EOPNOTSUPP;
 966                         goto err_out_unlock;
 967                 }
 968
 969                 spin_lock_bh(&queue->lock);
 970                 queue->flags &= ~mask;
 971                 queue->flags |= flags & mask;
 972                 spin_unlock_bh(&queue->lock);
 973         }
 974
 975 err_out_unlock:
 976         rcu_read_unlock();
 977         return ret;
 978 }
 979
 980 static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
 981         [NFQNL_MSG_PACKET]      = { .call_rcu = nfqnl_recv_unsupp,
 982                                     .attr_count = NFQA_MAX, },
 983         [NFQNL_MSG_VERDICT]     = { .call_rcu = nfqnl_recv_verdict,
 984                                     .attr_count = NFQA_MAX,
 985                                     .policy = nfqa_verdict_policy },
 986         [NFQNL_MSG_CONFIG]      = { .call = nfqnl_recv_config,
 987                                     .attr_count = NFQA_CFG_MAX,
 988                                     .policy = nfqa_cfg_policy },
 989         [NFQNL_MSG_VERDICT_BATCH]={ .call_rcu = nfqnl_recv_verdict_batch,
 990                                     .attr_count = NFQA_MAX,
 991                                     .policy = nfqa_verdict_batch_policy },
 992 };
 993
 994 static const struct nfnetlink_subsystem nfqnl_subsys = {
 995         .name           = "nf_queue",
 996         .subsys_id      = NFNL_SUBSYS_QUEUE,
 997         .cb_count       = NFQNL_MSG_MAX,
 998         .cb             = nfqnl_cb,
 999 };
1000
1001 #ifdef CONFIG_PROC_FS
1002 struct iter_state {
1003         unsigned int bucket;
1004 };
1005
1006 static struct hlist_node *get_first(struct seq_file *seq)
1007 {
1008         struct iter_state *st = seq->private;
1009
1010         if (!st)
1011                 return NULL;
1012
1013         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
1014                 if (!hlist_empty(&instance_table[st->bucket]))
1015                         return instance_table[st->bucket].first;
1016         }
1017         return NULL;
1018 }
1019
1020 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
1021 {
1022         struct iter_state *st = seq->private;
1023
1024         h = h->next;
1025         while (!h) {
1026                 if (++st->bucket >= INSTANCE_BUCKETS)
1027                         return NULL;
1028
1029                 h = instance_table[st->bucket].first;
1030         }
1031         return h;
1032 }
1033
1034 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
1035 {
1036         struct hlist_node *head;
1037         head = get_first(seq);
1038
1039         if (head)
1040                 while (pos && (head = get_next(seq, head)))
1041                         pos--;
1042         return pos ? NULL : head;
1043 }
1044
1045 static void *seq_start(struct seq_file *seq, loff_t *pos)
1046         __acquires(instances_lock)
1047 {
1048         spin_lock(&instances_lock);
1049         return get_idx(seq, *pos);
1050 }
1051
1052 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1053 {
1054         (*pos)++;
1055         return get_next(s, v);
1056 }
1057
1058 static void seq_stop(struct seq_file *s, void *v)
1059         __releases(instances_lock)
1060 {
1061         spin_unlock(&instances_lock);
1062 }
1063
1064 static int seq_show(struct seq_file *s, void *v)
1065 {
1066         const struct nfqnl_instance *inst = v;
1067
1068         return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n",
1069                           inst->queue_num,
1070                           inst->peer_portid, inst->queue_total,
1071                           inst->copy_mode, inst->copy_range,
1072                           inst->queue_dropped, inst->queue_user_dropped,
1073                           inst->id_sequence, 1);
1074 }
1075
1076 static const struct seq_operations nfqnl_seq_ops = {
1077         .start  = seq_start,
1078         .next   = seq_next,
1079         .stop   = seq_stop,
1080         .show   = seq_show,
1081 };
1082
1083 static int nfqnl_open(struct inode *inode, struct file *file)
1084 {
1085         return seq_open_private(file, &nfqnl_seq_ops,
1086                         sizeof(struct iter_state));
1087 }
1088
1089 static const struct file_operations nfqnl_file_ops = {
1090         .owner   = THIS_MODULE,
1091         .open    = nfqnl_open,
1092         .read    = seq_read,
1093         .llseek  = seq_lseek,
1094         .release = seq_release_private,
1095 };
1096
1097 #endif /* PROC_FS */
1098
1099 static int __init nfnetlink_queue_init(void)
1100 {
1101         int i, status = -ENOMEM;
1102
1103         for (i = 0; i < INSTANCE_BUCKETS; i++)
1104                 INIT_HLIST_HEAD(&instance_table[i]);
1105
1106         netlink_register_notifier(&nfqnl_rtnl_notifier);
1107         status = nfnetlink_subsys_register(&nfqnl_subsys);
1108         if (status < 0) {
1109                 printk(KERN_ERR "nf_queue: failed to create netlink socket\n");
1110                 goto cleanup_netlink_notifier;
1111         }
1112
1113 #ifdef CONFIG_PROC_FS
1114         if (!proc_create("nfnetlink_queue", 0440,
1115                          proc_net_netfilter, &nfqnl_file_ops))
1116                 goto cleanup_subsys;
1117 #endif
1118
1119         register_netdevice_notifier(&nfqnl_dev_notifier);
1120         nf_register_queue_handler(&nfqh);
1121         return status;
1122
1123 #ifdef CONFIG_PROC_FS
1124 cleanup_subsys:
1125         nfnetlink_subsys_unregister(&nfqnl_subsys);
1126 #endif
1127 cleanup_netlink_notifier:
1128         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1129         return status;
1130 }
1131
1132 static void __exit nfnetlink_queue_fini(void)
1133 {
1134         nf_unregister_queue_handler();
1135         unregister_netdevice_notifier(&nfqnl_dev_notifier);
1136 #ifdef CONFIG_PROC_FS
1137         remove_proc_entry("nfnetlink_queue", proc_net_netfilter);
1138 #endif
1139         nfnetlink_subsys_unregister(&nfqnl_subsys);
1140         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1141
1142         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1143 }
1144
1145 MODULE_DESCRIPTION("netfilter packet queue handler");
1146 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1147 MODULE_LICENSE("GPL");
1148 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1149
1150 module_init(nfnetlink_queue_init);
1151 module_exit(nfnetlink_queue_fini);