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