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