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_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
  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 portid)
  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_portid = portid;
 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, cap_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                + nla_total_size(sizeof(u_int32_t)));   /* cap_len */
 252
 253        outdev = entry->outdev;
 254
 255        switch ((enum nfqnl_config_mode)ACCESS_ONCE(queue->copy_mode)) {
 256        case NFQNL_COPY_META:
 257        case NFQNL_COPY_NONE:
 258                break;
 259
 260        case NFQNL_COPY_PACKET:
 261                if (entskb->ip_summed == CHECKSUM_PARTIAL &&
 262                    skb_checksum_help(entskb))
 263                        return NULL;
 264
 265                data_len = ACCESS_ONCE(queue->copy_range);
 266                if (data_len == 0 || data_len > entskb->len)
 267                        data_len = entskb->len;
 268
 269                size += nla_total_size(data_len);
 270                cap_len = entskb->len;
 271                break;
 272        }
 273
 274        if (queue->flags & NFQA_CFG_F_CONNTRACK)
 275                ct = nfqnl_ct_get(entskb, &size, &ctinfo);
 276
 277        skb = alloc_skb(size, GFP_ATOMIC);
 278        if (!skb)
 279                return NULL;
 280
 281        old_tail = skb->tail;
 282        nlh = nlmsg_put(skb, 0, 0,
 283                        NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET,
 284                        sizeof(struct nfgenmsg), 0);
 285        if (!nlh) {
 286                kfree_skb(skb);
 287                return NULL;
 288        }
 289        nfmsg = nlmsg_data(nlh);
 290        nfmsg->nfgen_family = entry->pf;
 291        nfmsg->version = NFNETLINK_V0;
 292        nfmsg->res_id = htons(queue->queue_num);
 293
 294        nla = __nla_reserve(skb, NFQA_PACKET_HDR, sizeof(*pmsg));
 295        pmsg = nla_data(nla);
 296        pmsg->hw_protocol       = entskb->protocol;
 297        pmsg->hook              = entry->hook;
 298        *packet_id_ptr          = &pmsg->packet_id;
 299
 300        indev = entry->indev;
 301        if (indev) {
 302#ifndef CONFIG_BRIDGE_NETFILTER
 303                if (nla_put_be32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex)))
 304                        goto nla_put_failure;
 305#else
 306                if (entry->pf == PF_BRIDGE) {
 307                        /* Case 1: indev is physical input device, we need to
 308                         * look for bridge group (when called from
 309                         * netfilter_bridge) */
 310                        if (nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
 311                                         htonl(indev->ifindex)) ||
 312                        /* this is the bridge group "brX" */
 313                        /* rcu_read_lock()ed by __nf_queue */
 314                            nla_put_be32(skb, NFQA_IFINDEX_INDEV,
 315                                         htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
 316                                goto nla_put_failure;
 317                } else {
 318                        /* Case 2: indev is bridge group, we need to look for
 319                         * physical device (when called from ipv4) */
 320                        if (nla_put_be32(skb, NFQA_IFINDEX_INDEV,
 321                                         htonl(indev->ifindex)))
 322                                goto nla_put_failure;
 323                        if (entskb->nf_bridge && entskb->nf_bridge->physindev &&
 324                            nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
 325                                         htonl(entskb->nf_bridge->physindev->ifindex)))
 326                                goto nla_put_failure;
 327                }
 328#endif
 329        }
 330
 331        if (outdev) {
 332#ifndef CONFIG_BRIDGE_NETFILTER
 333                if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex)))
 334                        goto nla_put_failure;
 335#else
 336                if (entry->pf == PF_BRIDGE) {
 337                        /* Case 1: outdev is physical output device, we need to
 338                         * look for bridge group (when called from
 339                         * netfilter_bridge) */
 340                        if (nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
 341                                         htonl(outdev->ifindex)) ||
 342                        /* this is the bridge group "brX" */
 343                        /* rcu_read_lock()ed by __nf_queue */
 344                            nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
 345                                         htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
 346                                goto nla_put_failure;
 347                } else {
 348                        /* Case 2: outdev is bridge group, we need to look for
 349                         * physical output device (when called from ipv4) */
 350                        if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
 351                                         htonl(outdev->ifindex)))
 352                                goto nla_put_failure;
 353                        if (entskb->nf_bridge && entskb->nf_bridge->physoutdev &&
 354                            nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
 355                                         htonl(entskb->nf_bridge->physoutdev->ifindex)))
 356                                goto nla_put_failure;
 357                }
 358#endif
 359        }
 360
 361        if (entskb->mark &&
 362            nla_put_be32(skb, NFQA_MARK, htonl(entskb->mark)))
 363                goto nla_put_failure;
 364
 365        if (indev && entskb->dev &&
 366            entskb->mac_header != entskb->network_header) {
 367                struct nfqnl_msg_packet_hw phw;
 368                int len = dev_parse_header(entskb, phw.hw_addr);
 369                if (len) {
 370                        phw.hw_addrlen = htons(len);
 371                        if (nla_put(skb, NFQA_HWADDR, sizeof(phw), &phw))
 372                                goto nla_put_failure;
 373                }
 374        }
 375
 376        if (entskb->tstamp.tv64) {
 377                struct nfqnl_msg_packet_timestamp ts;
 378                struct timeval tv = ktime_to_timeval(entskb->tstamp);
 379                ts.sec = cpu_to_be64(tv.tv_sec);
 380                ts.usec = cpu_to_be64(tv.tv_usec);
 381
 382                if (nla_put(skb, NFQA_TIMESTAMP, sizeof(ts), &ts))
 383                        goto nla_put_failure;
 384        }
 385
 386        if (data_len) {
 387                struct nlattr *nla;
 388                int sz = nla_attr_size(data_len);
 389
 390                if (skb_tailroom(skb) < nla_total_size(data_len)) {
 391                        printk(KERN_WARNING "nf_queue: no tailroom!\n");
 392                        kfree_skb(skb);
 393                        return NULL;
 394                }
 395
 396                nla = (struct nlattr *)skb_put(skb, nla_total_size(data_len));
 397                nla->nla_type = NFQA_PAYLOAD;
 398                nla->nla_len = sz;
 399
 400                if (skb_copy_bits(entskb, 0, nla_data(nla), data_len))
 401                        BUG();
 402        }
 403
 404        if (ct && nfqnl_ct_put(skb, ct, ctinfo) < 0)
 405                goto nla_put_failure;
 406
 407        if (cap_len > 0 && nla_put_be32(skb, NFQA_CAP_LEN, htonl(cap_len)))
 408                goto nla_put_failure;
 409
 410        nlh->nlmsg_len = skb->tail - old_tail;
 411        return skb;
 412
 413nla_put_failure:
 414        kfree_skb(skb);
 415        net_err_ratelimited("nf_queue: error creating packet message\n");
 416        return NULL;
 417}
 418
 419static int
 420nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
 421{
 422        struct sk_buff *nskb;
 423        struct nfqnl_instance *queue;
 424        int err = -ENOBUFS;
 425        __be32 *packet_id_ptr;
 426        int failopen = 0;
 427
 428        /* rcu_read_lock()ed by nf_hook_slow() */
 429        queue = instance_lookup(queuenum);
 430        if (!queue) {
 431                err = -ESRCH;
 432                goto err_out;
 433        }
 434
 435        if (queue->copy_mode == NFQNL_COPY_NONE) {
 436                err = -EINVAL;
 437                goto err_out;
 438        }
 439
 440        nskb = nfqnl_build_packet_message(queue, entry, &packet_id_ptr);
 441        if (nskb == NULL) {
 442                err = -ENOMEM;
 443                goto err_out;
 444        }
 445        spin_lock_bh(&queue->lock);
 446
 447        if (!queue->peer_portid) {
 448                err = -EINVAL;
 449                goto err_out_free_nskb;
 450        }
 451        if (queue->queue_total >= queue->queue_maxlen) {
 452                if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
 453                        failopen = 1;
 454                        err = 0;
 455                } else {
 456                        queue->queue_dropped++;
 457                        net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n",
 458                                             queue->queue_total);
 459                }
 460                goto err_out_free_nskb;
 461        }
 462        entry->id = ++queue->id_sequence;
 463        *packet_id_ptr = htonl(entry->id);
 464
 465        /* nfnetlink_unicast will either free the nskb or add it to a socket */
 466        err = nfnetlink_unicast(nskb, &init_net, queue->peer_portid, MSG_DONTWAIT);
 467        if (err < 0) {
 468                queue->queue_user_dropped++;
 469                goto err_out_unlock;
 470        }
 471
 472        __enqueue_entry(queue, entry);
 473
 474        spin_unlock_bh(&queue->lock);
 475        return 0;
 476
 477err_out_free_nskb:
 478        kfree_skb(nskb);
 479err_out_unlock:
 480        spin_unlock_bh(&queue->lock);
 481        if (failopen)
 482                nf_reinject(entry, NF_ACCEPT);
 483err_out:
 484        return err;
 485}
 486
 487static int
 488nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e, int diff)
 489{
 490        struct sk_buff *nskb;
 491
 492        if (diff < 0) {
 493                if (pskb_trim(e->skb, data_len))
 494                        return -ENOMEM;
 495        } else if (diff > 0) {
 496                if (data_len > 0xFFFF)
 497                        return -EINVAL;
 498                if (diff > skb_tailroom(e->skb)) {
 499                        nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
 500                                               diff, GFP_ATOMIC);
 501                        if (!nskb) {
 502                                printk(KERN_WARNING "nf_queue: OOM "
 503                                      "in mangle, dropping packet\n");
 504                                return -ENOMEM;
 505                        }
 506                        kfree_skb(e->skb);
 507                        e->skb = nskb;
 508                }
 509                skb_put(e->skb, diff);
 510        }
 511        if (!skb_make_writable(e->skb, data_len))
 512                return -ENOMEM;
 513        skb_copy_to_linear_data(e->skb, data, data_len);
 514        e->skb->ip_summed = CHECKSUM_NONE;
 515        return 0;
 516}
 517
 518static int
 519nfqnl_set_mode(struct nfqnl_instance *queue,
 520               unsigned char mode, unsigned int range)
 521{
 522        int status = 0;
 523
 524        spin_lock_bh(&queue->lock);
 525        switch (mode) {
 526        case NFQNL_COPY_NONE:
 527        case NFQNL_COPY_META:
 528                queue->copy_mode = mode;
 529                queue->copy_range = 0;
 530                break;
 531
 532        case NFQNL_COPY_PACKET:
 533                queue->copy_mode = mode;
 534                /* We're using struct nlattr which has 16bit nla_len. Note that
 535                 * nla_len includes the header length. Thus, the maximum packet
 536                 * length that we support is 65531 bytes. We send truncated
 537                 * packets if the specified length is larger than that.
 538                 */
 539                if (range > 0xffff - NLA_HDRLEN)
 540                        queue->copy_range = 0xffff - NLA_HDRLEN;
 541                else
 542                        queue->copy_range = range;
 543                break;
 544
 545        default:
 546                status = -EINVAL;
 547
 548        }
 549        spin_unlock_bh(&queue->lock);
 550
 551        return status;
 552}
 553
 554static int
 555dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
 556{
 557        if (entry->indev)
 558                if (entry->indev->ifindex == ifindex)
 559                        return 1;
 560        if (entry->outdev)
 561                if (entry->outdev->ifindex == ifindex)
 562                        return 1;
 563#ifdef CONFIG_BRIDGE_NETFILTER
 564        if (entry->skb->nf_bridge) {
 565                if (entry->skb->nf_bridge->physindev &&
 566                    entry->skb->nf_bridge->physindev->ifindex == ifindex)
 567                        return 1;
 568                if (entry->skb->nf_bridge->physoutdev &&
 569                    entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
 570                        return 1;
 571        }
 572#endif
 573        return 0;
 574}
 575
 576/* drop all packets with either indev or outdev == ifindex from all queue
 577 * instances */
 578static void
 579nfqnl_dev_drop(int ifindex)
 580{
 581        int i;
 582
 583        rcu_read_lock();
 584
 585        for (i = 0; i < INSTANCE_BUCKETS; i++) {
 586                struct hlist_node *tmp;
 587                struct nfqnl_instance *inst;
 588                struct hlist_head *head = &instance_table[i];
 589
 590                hlist_for_each_entry_rcu(inst, tmp, head, hlist)
 591                        nfqnl_flush(inst, dev_cmp, ifindex);
 592        }
 593
 594        rcu_read_unlock();
 595}
 596
 597#define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 598
 599static int
 600nfqnl_rcv_dev_event(struct notifier_block *this,
 601                    unsigned long event, void *ptr)
 602{
 603        struct net_device *dev = ptr;
 604
 605        if (!net_eq(dev_net(dev), &init_net))
 606                return NOTIFY_DONE;
 607
 608        /* Drop any packets associated with the downed device */
 609        if (event == NETDEV_DOWN)
 610                nfqnl_dev_drop(dev->ifindex);
 611        return NOTIFY_DONE;
 612}
 613
 614static struct notifier_block nfqnl_dev_notifier = {
 615        .notifier_call  = nfqnl_rcv_dev_event,
 616};
 617
 618static int
 619nfqnl_rcv_nl_event(struct notifier_block *this,
 620                   unsigned long event, void *ptr)
 621{
 622        struct netlink_notify *n = ptr;
 623
 624        if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
 625                int i;
 626
 627                /* destroy all instances for this portid */
 628                spin_lock(&instances_lock);
 629                for (i = 0; i < INSTANCE_BUCKETS; i++) {
 630                        struct hlist_node *tmp, *t2;
 631                        struct nfqnl_instance *inst;
 632                        struct hlist_head *head = &instance_table[i];
 633
 634                        hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
 635                                if ((n->net == &init_net) &&
 636                                    (n->portid == inst->peer_portid))
 637                                        __instance_destroy(inst);
 638                        }
 639                }
 640                spin_unlock(&instances_lock);
 641        }
 642        return NOTIFY_DONE;
 643}
 644
 645static struct notifier_block nfqnl_rtnl_notifier = {
 646        .notifier_call  = nfqnl_rcv_nl_event,
 647};
 648
 649static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = {
 650        [NFQA_VERDICT_HDR]      = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
 651        [NFQA_MARK]             = { .type = NLA_U32 },
 652        [NFQA_PAYLOAD]          = { .type = NLA_UNSPEC },
 653        [NFQA_CT]               = { .type = NLA_UNSPEC },
 654};
 655
 656static const struct nla_policy nfqa_verdict_batch_policy[NFQA_MAX+1] = {
 657        [NFQA_VERDICT_HDR]      = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
 658        [NFQA_MARK]             = { .type = NLA_U32 },
 659};
 660
 661static struct nfqnl_instance *verdict_instance_lookup(u16 queue_num, int nlportid)
 662{
 663        struct nfqnl_instance *queue;
 664
 665        queue = instance_lookup(queue_num);
 666        if (!queue)
 667                return ERR_PTR(-ENODEV);
 668
 669        if (queue->peer_portid != nlportid)
 670                return ERR_PTR(-EPERM);
 671
 672        return queue;
 673}
 674
 675static struct nfqnl_msg_verdict_hdr*
 676verdicthdr_get(const struct nlattr * const nfqa[])
 677{
 678        struct nfqnl_msg_verdict_hdr *vhdr;
 679        unsigned int verdict;
 680
 681        if (!nfqa[NFQA_VERDICT_HDR])
 682                return NULL;
 683
 684        vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
 685        verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK;
 686        if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN)
 687                return NULL;
 688        return vhdr;
 689}
 690
 691static int nfq_id_after(unsigned int id, unsigned int max)
 692{
 693        return (int)(id - max) > 0;
 694}
 695
 696static int
 697nfqnl_recv_verdict_batch(struct sock *ctnl, struct sk_buff *skb,
 698                   const struct nlmsghdr *nlh,
 699                   const struct nlattr * const nfqa[])
 700{
 701        struct nfgenmsg *nfmsg = nlmsg_data(nlh);
 702        struct nf_queue_entry *entry, *tmp;
 703        unsigned int verdict, maxid;
 704        struct nfqnl_msg_verdict_hdr *vhdr;
 705        struct nfqnl_instance *queue;
 706        LIST_HEAD(batch_list);
 707        u16 queue_num = ntohs(nfmsg->res_id);
 708
 709        queue = verdict_instance_lookup(queue_num, NETLINK_CB(skb).portid);
 710        if (IS_ERR(queue))
 711                return PTR_ERR(queue);
 712
 713        vhdr = verdicthdr_get(nfqa);
 714        if (!vhdr)
 715                return -EINVAL;
 716
 717        verdict = ntohl(vhdr->verdict);
 718        maxid = ntohl(vhdr->id);
 719
 720        spin_lock_bh(&queue->lock);
 721
 722        list_for_each_entry_safe(entry, tmp, &queue->queue_list, list) {
 723                if (nfq_id_after(entry->id, maxid))
 724                        break;
 725                __dequeue_entry(queue, entry);
 726                list_add_tail(&entry->list, &batch_list);
 727        }
 728
 729        spin_unlock_bh(&queue->lock);
 730
 731        if (list_empty(&batch_list))
 732                return -ENOENT;
 733
 734        list_for_each_entry_safe(entry, tmp, &batch_list, list) {
 735                if (nfqa[NFQA_MARK])
 736                        entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
 737                nf_reinject(entry, verdict);
 738        }
 739        return 0;
 740}
 741
 742static int
 743nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
 744                   const struct nlmsghdr *nlh,
 745                   const struct nlattr * const nfqa[])
 746{
 747        struct nfgenmsg *nfmsg = nlmsg_data(nlh);
 748        u_int16_t queue_num = ntohs(nfmsg->res_id);
 749
 750        struct nfqnl_msg_verdict_hdr *vhdr;
 751        struct nfqnl_instance *queue;
 752        unsigned int verdict;
 753        struct nf_queue_entry *entry;
 754        enum ip_conntrack_info uninitialized_var(ctinfo);
 755        struct nf_conn *ct = NULL;
 756
 757        queue = instance_lookup(queue_num);
 758        if (!queue)
 759
 760        queue = verdict_instance_lookup(queue_num, NETLINK_CB(skb).portid);
 761        if (IS_ERR(queue))
 762                return PTR_ERR(queue);
 763
 764        vhdr = verdicthdr_get(nfqa);
 765        if (!vhdr)
 766                return -EINVAL;
 767
 768        verdict = ntohl(vhdr->verdict);
 769
 770        entry = find_dequeue_entry(queue, ntohl(vhdr->id));
 771        if (entry == NULL)
 772                return -ENOENT;
 773
 774        rcu_read_lock();
 775        if (nfqa[NFQA_CT] && (queue->flags & NFQA_CFG_F_CONNTRACK))
 776                ct = nfqnl_ct_parse(entry->skb, nfqa[NFQA_CT], &ctinfo);
 777
 778        if (nfqa[NFQA_PAYLOAD]) {
 779                u16 payload_len = nla_len(nfqa[NFQA_PAYLOAD]);
 780                int diff = payload_len - entry->skb->len;
 781
 782                if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
 783                                 payload_len, entry, diff) < 0)
 784                        verdict = NF_DROP;
 785
 786                if (ct)
 787                        nfqnl_ct_seq_adjust(skb, ct, ctinfo, diff);
 788        }
 789        rcu_read_unlock();
 790
 791        if (nfqa[NFQA_MARK])
 792                entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
 793
 794        nf_reinject(entry, verdict);
 795        return 0;
 796}
 797
 798static int
 799nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
 800                  const struct nlmsghdr *nlh,
 801                  const struct nlattr * const nfqa[])
 802{
 803        return -ENOTSUPP;
 804}
 805
 806static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
 807        [NFQA_CFG_CMD]          = { .len = sizeof(struct nfqnl_msg_config_cmd) },
 808        [NFQA_CFG_PARAMS]       = { .len = sizeof(struct nfqnl_msg_config_params) },
 809};
 810
 811static const struct nf_queue_handler nfqh = {
 812        .name   = "nf_queue",
 813        .outfn  = &nfqnl_enqueue_packet,
 814};
 815
 816static int
 817nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 818                  const struct nlmsghdr *nlh,
 819                  const struct nlattr * const nfqa[])
 820{
 821        struct nfgenmsg *nfmsg = nlmsg_data(nlh);
 822        u_int16_t queue_num = ntohs(nfmsg->res_id);
 823        struct nfqnl_instance *queue;
 824        struct nfqnl_msg_config_cmd *cmd = NULL;
 825        int ret = 0;
 826
 827        if (nfqa[NFQA_CFG_CMD]) {
 828                cmd = nla_data(nfqa[NFQA_CFG_CMD]);
 829
 830                /* Commands without queue context - might sleep */
 831                switch (cmd->command) {
 832                case NFQNL_CFG_CMD_PF_BIND:
 833                        return nf_register_queue_handler(ntohs(cmd->pf),
 834                                                         &nfqh);
 835                case NFQNL_CFG_CMD_PF_UNBIND:
 836                        return nf_unregister_queue_handler(ntohs(cmd->pf),
 837                                                           &nfqh);
 838                }
 839        }
 840
 841        rcu_read_lock();
 842        queue = instance_lookup(queue_num);
 843        if (queue && queue->peer_portid != NETLINK_CB(skb).portid) {
 844                ret = -EPERM;
 845                goto err_out_unlock;
 846        }
 847
 848        if (cmd != NULL) {
 849                switch (cmd->command) {
 850                case NFQNL_CFG_CMD_BIND:
 851                        if (queue) {
 852                                ret = -EBUSY;
 853                                goto err_out_unlock;
 854                        }
 855                        queue = instance_create(queue_num, NETLINK_CB(skb).portid);
 856                        if (IS_ERR(queue)) {
 857                                ret = PTR_ERR(queue);
 858                                goto err_out_unlock;
 859                        }
 860                        break;
 861                case NFQNL_CFG_CMD_UNBIND:
 862                        if (!queue) {
 863                                ret = -ENODEV;
 864                                goto err_out_unlock;
 865                        }
 866                        instance_destroy(queue);
 867                        break;
 868                case NFQNL_CFG_CMD_PF_BIND:
 869                case NFQNL_CFG_CMD_PF_UNBIND:
 870                        break;
 871                default:
 872                        ret = -ENOTSUPP;
 873                        break;
 874                }
 875        }
 876
 877        if (nfqa[NFQA_CFG_PARAMS]) {
 878                struct nfqnl_msg_config_params *params;
 879
 880                if (!queue) {
 881                        ret = -ENODEV;
 882                        goto err_out_unlock;
 883                }
 884                params = nla_data(nfqa[NFQA_CFG_PARAMS]);
 885                nfqnl_set_mode(queue, params->copy_mode,
 886                                ntohl(params->copy_range));
 887        }
 888
 889        if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
 890                __be32 *queue_maxlen;
 891
 892                if (!queue) {
 893                        ret = -ENODEV;
 894                        goto err_out_unlock;
 895                }
 896                queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
 897                spin_lock_bh(&queue->lock);
 898                queue->queue_maxlen = ntohl(*queue_maxlen);
 899                spin_unlock_bh(&queue->lock);
 900        }
 901
 902        if (nfqa[NFQA_CFG_FLAGS]) {
 903                __u32 flags, mask;
 904
 905                if (!queue) {
 906                        ret = -ENODEV;
 907                        goto err_out_unlock;
 908                }
 909
 910                if (!nfqa[NFQA_CFG_MASK]) {
 911                        /* A mask is needed to specify which flags are being
 912                         * changed.
 913                         */
 914                        ret = -EINVAL;
 915                        goto err_out_unlock;
 916                }
 917
 918                flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS]));
 919                mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK]));
 920
 921                if (flags >= NFQA_CFG_F_MAX) {
 922                        ret = -EOPNOTSUPP;
 923                        goto err_out_unlock;
 924                }
 925
 926                spin_lock_bh(&queue->lock);
 927                queue->flags &= ~mask;
 928                queue->flags |= flags & mask;
 929                spin_unlock_bh(&queue->lock);
 930        }
 931
 932err_out_unlock:
 933        rcu_read_unlock();
 934        return ret;
 935}
 936
 937static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
 938        [NFQNL_MSG_PACKET]      = { .call_rcu = nfqnl_recv_unsupp,
 939                                    .attr_count = NFQA_MAX, },
 940        [NFQNL_MSG_VERDICT]     = { .call_rcu = nfqnl_recv_verdict,
 941                                    .attr_count = NFQA_MAX,
 942                                    .policy = nfqa_verdict_policy },
 943        [NFQNL_MSG_CONFIG]      = { .call = nfqnl_recv_config,
 944                                    .attr_count = NFQA_CFG_MAX,
 945                                    .policy = nfqa_cfg_policy },
 946        [NFQNL_MSG_VERDICT_BATCH]={ .call_rcu = nfqnl_recv_verdict_batch,
 947                                    .attr_count = NFQA_MAX,
 948                                    .policy = nfqa_verdict_batch_policy },
 949};
 950
 951static const struct nfnetlink_subsystem nfqnl_subsys = {
 952        .name           = "nf_queue",
 953        .subsys_id      = NFNL_SUBSYS_QUEUE,
 954        .cb_count       = NFQNL_MSG_MAX,
 955        .cb             = nfqnl_cb,
 956};
 957
 958#ifdef CONFIG_PROC_FS
 959struct iter_state {
 960        unsigned int bucket;
 961};
 962
 963static struct hlist_node *get_first(struct seq_file *seq)
 964{
 965        struct iter_state *st = seq->private;
 966
 967        if (!st)
 968                return NULL;
 969
 970        for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
 971                if (!hlist_empty(&instance_table[st->bucket]))
 972                        return instance_table[st->bucket].first;
 973        }
 974        return NULL;
 975}
 976
 977static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
 978{
 979        struct iter_state *st = seq->private;
 980
 981        h = h->next;
 982        while (!h) {
 983                if (++st->bucket >= INSTANCE_BUCKETS)
 984                        return NULL;
 985
 986                h = instance_table[st->bucket].first;
 987        }
 988        return h;
 989}
 990
 991static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
 992{
 993        struct hlist_node *head;
 994        head = get_first(seq);
 995
 996        if (head)
 997                while (pos && (head = get_next(seq, head)))
 998                        pos--;
 999        return pos ? NULL : head;
1000}
1001
1002static void *seq_start(struct seq_file *seq, loff_t *pos)
1003        __acquires(instances_lock)
1004{
1005        spin_lock(&instances_lock);
1006        return get_idx(seq, *pos);
1007}
1008
1009static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1010{
1011        (*pos)++;
1012        return get_next(s, v);
1013}
1014
1015static void seq_stop(struct seq_file *s, void *v)
1016        __releases(instances_lock)
1017{
1018        spin_unlock(&instances_lock);
1019}
1020
1021static int seq_show(struct seq_file *s, void *v)
1022{
1023        const struct nfqnl_instance *inst = v;
1024
1025        return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n",
1026                          inst->queue_num,
1027                          inst->peer_portid, inst->queue_total,
1028                          inst->copy_mode, inst->copy_range,
1029                          inst->queue_dropped, inst->queue_user_dropped,
1030                          inst->id_sequence, 1);
1031}
1032
1033static const struct seq_operations nfqnl_seq_ops = {
1034        .start  = seq_start,
1035        .next   = seq_next,
1036        .stop   = seq_stop,
1037        .show   = seq_show,
1038};
1039
1040static int nfqnl_open(struct inode *inode, struct file *file)
1041{
1042        return seq_open_private(file, &nfqnl_seq_ops,
1043                        sizeof(struct iter_state));
1044}
1045
1046static const struct file_operations nfqnl_file_ops = {
1047        .owner   = THIS_MODULE,
1048        .open    = nfqnl_open,
1049        .read    = seq_read,
1050        .llseek  = seq_lseek,
1051        .release = seq_release_private,
1052};
1053
1054#endif /* PROC_FS */
1055
1056static int __init nfnetlink_queue_init(void)
1057{
1058        int i, status = -ENOMEM;
1059
1060        for (i = 0; i < INSTANCE_BUCKETS; i++)
1061                INIT_HLIST_HEAD(&instance_table[i]);
1062
1063        netlink_register_notifier(&nfqnl_rtnl_notifier);
1064        status = nfnetlink_subsys_register(&nfqnl_subsys);
1065        if (status < 0) {
1066                printk(KERN_ERR "nf_queue: failed to create netlink socket\n");
1067                goto cleanup_netlink_notifier;
1068        }
1069
1070#ifdef CONFIG_PROC_FS
1071        if (!proc_create("nfnetlink_queue", 0440,
1072                         proc_net_netfilter, &nfqnl_file_ops))
1073                goto cleanup_subsys;
1074#endif
1075
1076        register_netdevice_notifier(&nfqnl_dev_notifier);
1077        return status;
1078
1079#ifdef CONFIG_PROC_FS
1080cleanup_subsys:
1081        nfnetlink_subsys_unregister(&nfqnl_subsys);
1082#endif
1083cleanup_netlink_notifier:
1084        netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1085        return status;
1086}
1087
1088static void __exit nfnetlink_queue_fini(void)
1089{
1090        nf_unregister_queue_handlers(&nfqh);
1091        unregister_netdevice_notifier(&nfqnl_dev_notifier);
1092#ifdef CONFIG_PROC_FS
1093        remove_proc_entry("nfnetlink_queue", proc_net_netfilter);
1094#endif
1095        nfnetlink_subsys_unregister(&nfqnl_subsys);
1096        netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1097
1098        rcu_barrier(); /* Wait for completion of call_rcu()'s */
1099}
1100
1101MODULE_DESCRIPTION("netfilter packet queue handler");
1102MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1103MODULE_LICENSE("GPL");
1104MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1105
1106module_init(nfnetlink_queue_init);
1107module_exit(nfnetlink_queue_fini);
1108
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