git.oblomov.eu Git - linux-2.6/blob - net/netfilter/nfnetlink_queue.c

   1 /*
   2  * This is a module which is used for queueing packets and communicating with
   3  * userspace via nfetlink.
   4  *
   5  * (C) 2005 by Harald Welte <laforge@netfilter.org>
   6  *
   7  * Based on the old ipv4-only ip_queue.c:
   8  * (C) 2000-2002 James Morris <jmorris@intercode.com.au>
   9  * (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  *
  15  */
  16 #include <linux/module.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/init.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/notifier.h>
  21 #include <linux/netdevice.h>
  22 #include <linux/netfilter.h>
  23 #include <linux/proc_fs.h>
  24 #include <linux/netfilter_ipv4.h>
  25 #include <linux/netfilter_ipv6.h>
  26 #include <linux/netfilter/nfnetlink.h>
  27 #include <linux/netfilter/nfnetlink_queue.h>
  28 #include <linux/list.h>
  29 #include <net/sock.h>
  30
  31 #include <asm/atomic.h>
  32
  33 #ifdef CONFIG_BRIDGE_NETFILTER
  34 #include "../bridge/br_private.h"
  35 #endif
  36
  37 #define NFQNL_QMAX_DEFAULT 1024
  38
  39 #if 0
  40 #define QDEBUG(x, args ...)     printk(KERN_DEBUG "%s(%d):%s(): " x,       \
  41                                         __FILE__, __LINE__, __FUNCTION__,  \
  42                                         ## args)
  43 #else
  44 #define QDEBUG(x, ...)
  45 #endif
  46
  47 struct nfqnl_queue_entry {
  48         struct list_head list;
  49         struct nf_info *info;
  50         struct sk_buff *skb;
  51         unsigned int id;
  52 };
  53
  54 struct nfqnl_instance {
  55         struct hlist_node hlist;                /* global list of queues */
  56         atomic_t use;
  57
  58         int peer_pid;
  59         unsigned int queue_maxlen;
  60         unsigned int copy_range;
  61         unsigned int queue_total;
  62         unsigned int queue_dropped;
  63         unsigned int queue_user_dropped;
  64
  65         atomic_t id_sequence;                   /* 'sequence' of pkt ids */
  66
  67         u_int16_t queue_num;                    /* number of this queue */
  68         u_int8_t copy_mode;
  69
  70         spinlock_t lock;
  71
  72         struct list_head queue_list;            /* packets in queue */
  73 };
  74
  75 typedef int (*nfqnl_cmpfn)(struct nfqnl_queue_entry *, unsigned long);
  76
  77 static DEFINE_RWLOCK(instances_lock);
  78
  79 #define INSTANCE_BUCKETS        16
  80 static struct hlist_head instance_table[INSTANCE_BUCKETS];
  81
  82 static inline u_int8_t instance_hashfn(u_int16_t queue_num)
  83 {
  84         return ((queue_num >> 8) | queue_num) % INSTANCE_BUCKETS;
  85 }
  86
  87 static struct nfqnl_instance *
  88 __instance_lookup(u_int16_t queue_num)
  89 {
  90         struct hlist_head *head;
  91         struct hlist_node *pos;
  92         struct nfqnl_instance *inst;
  93
  94         head = &instance_table[instance_hashfn(queue_num)];
  95         hlist_for_each_entry(inst, pos, head, hlist) {
  96                 if (inst->queue_num == queue_num)
  97                         return inst;
  98         }
  99         return NULL;
 100 }
 101
 102 static struct nfqnl_instance *
 103 instance_lookup_get(u_int16_t queue_num)
 104 {
 105         struct nfqnl_instance *inst;
 106
 107         read_lock_bh(&instances_lock);
 108         inst = __instance_lookup(queue_num);
 109         if (inst)
 110                 atomic_inc(&inst->use);
 111         read_unlock_bh(&instances_lock);
 112
 113         return inst;
 114 }
 115
 116 static void
 117 instance_put(struct nfqnl_instance *inst)
 118 {
 119         if (inst && atomic_dec_and_test(&inst->use)) {
 120                 QDEBUG("kfree(inst=%p)\n", inst);
 121                 kfree(inst);
 122         }
 123 }
 124
 125 static struct nfqnl_instance *
 126 instance_create(u_int16_t queue_num, int pid)
 127 {
 128         struct nfqnl_instance *inst;
 129
 130         QDEBUG("entering for queue_num=%u, pid=%d\n", queue_num, pid);
 131
 132         write_lock_bh(&instances_lock);
 133         if (__instance_lookup(queue_num)) {
 134                 inst = NULL;
 135                 QDEBUG("aborting, instance already exists\n");
 136                 goto out_unlock;
 137         }
 138
 139         inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
 140         if (!inst)
 141                 goto out_unlock;
 142
 143         inst->queue_num = queue_num;
 144         inst->peer_pid = pid;
 145         inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
 146         inst->copy_range = 0xfffff;
 147         inst->copy_mode = NFQNL_COPY_NONE;
 148         atomic_set(&inst->id_sequence, 0);
 149         /* needs to be two, since we _put() after creation */
 150         atomic_set(&inst->use, 2);
 151         spin_lock_init(&inst->lock);
 152         INIT_LIST_HEAD(&inst->queue_list);
 153
 154         if (!try_module_get(THIS_MODULE))
 155                 goto out_free;
 156
 157         hlist_add_head(&inst->hlist,
 158                        &instance_table[instance_hashfn(queue_num)]);
 159
 160         write_unlock_bh(&instances_lock);
 161
 162         QDEBUG("successfully created new instance\n");
 163
 164         return inst;
 165
 166 out_free:
 167         kfree(inst);
 168 out_unlock:
 169         write_unlock_bh(&instances_lock);
 170         return NULL;
 171 }
 172
 173 static void nfqnl_flush(struct nfqnl_instance *queue, int verdict);
 174
 175 static void
 176 _instance_destroy2(struct nfqnl_instance *inst, int lock)
 177 {
 178         /* first pull it out of the global list */
 179         if (lock)
 180                 write_lock_bh(&instances_lock);
 181
 182         QDEBUG("removing instance %p (queuenum=%u) from hash\n",
 183                 inst, inst->queue_num);
 184         hlist_del(&inst->hlist);
 185
 186         if (lock)
 187                 write_unlock_bh(&instances_lock);
 188
 189         /* then flush all pending skbs from the queue */
 190         nfqnl_flush(inst, NF_DROP);
 191
 192         /* and finally put the refcount */
 193         instance_put(inst);
 194
 195         module_put(THIS_MODULE);
 196 }
 197
 198 static inline void
 199 __instance_destroy(struct nfqnl_instance *inst)
 200 {
 201         _instance_destroy2(inst, 0);
 202 }
 203
 204 static inline void
 205 instance_destroy(struct nfqnl_instance *inst)
 206 {
 207         _instance_destroy2(inst, 1);
 208 }
 209
 210
 211
 212 static void
 213 issue_verdict(struct nfqnl_queue_entry *entry, int verdict)
 214 {
 215         QDEBUG("entering for entry %p, verdict %u\n", entry, verdict);
 216
 217         /* TCP input path (and probably other bits) assume to be called
 218          * from softirq context, not from syscall, like issue_verdict is
 219          * called.  TCP input path deadlocks with locks taken from timer
 220          * softirq, e.g.  We therefore emulate this by local_bh_disable() */
 221
 222         local_bh_disable();
 223         nf_reinject(entry->skb, entry->info, verdict);
 224         local_bh_enable();
 225
 226         kfree(entry);
 227 }
 228
 229 static inline void
 230 __enqueue_entry(struct nfqnl_instance *queue,
 231                       struct nfqnl_queue_entry *entry)
 232 {
 233        list_add(&entry->list, &queue->queue_list);
 234        queue->queue_total++;
 235 }
 236
 237 /*
 238  * Find and return a queued entry matched by cmpfn, or return the last
 239  * entry if cmpfn is NULL.
 240  */
 241 static inline struct nfqnl_queue_entry *
 242 __find_entry(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
 243                    unsigned long data)
 244 {
 245         struct list_head *p;
 246
 247         list_for_each_prev(p, &queue->queue_list) {
 248                 struct nfqnl_queue_entry *entry = (struct nfqnl_queue_entry *)p;
 249
 250                 if (!cmpfn || cmpfn(entry, data))
 251                         return entry;
 252         }
 253         return NULL;
 254 }
 255
 256 static inline void
 257 __dequeue_entry(struct nfqnl_instance *q, struct nfqnl_queue_entry *entry)
 258 {
 259         list_del(&entry->list);
 260         q->queue_total--;
 261 }
 262
 263 static inline struct nfqnl_queue_entry *
 264 __find_dequeue_entry(struct nfqnl_instance *queue,
 265                      nfqnl_cmpfn cmpfn, unsigned long data)
 266 {
 267         struct nfqnl_queue_entry *entry;
 268
 269         entry = __find_entry(queue, cmpfn, data);
 270         if (entry == NULL)
 271                 return NULL;
 272
 273         __dequeue_entry(queue, entry);
 274         return entry;
 275 }
 276
 277
 278 static inline void
 279 __nfqnl_flush(struct nfqnl_instance *queue, int verdict)
 280 {
 281         struct nfqnl_queue_entry *entry;
 282
 283         while ((entry = __find_dequeue_entry(queue, NULL, 0)))
 284                 issue_verdict(entry, verdict);
 285 }
 286
 287 static inline int
 288 __nfqnl_set_mode(struct nfqnl_instance *queue,
 289                  unsigned char mode, unsigned int range)
 290 {
 291         int status = 0;
 292
 293         switch (mode) {
 294         case NFQNL_COPY_NONE:
 295         case NFQNL_COPY_META:
 296                 queue->copy_mode = mode;
 297                 queue->copy_range = 0;
 298                 break;
 299
 300         case NFQNL_COPY_PACKET:
 301                 queue->copy_mode = mode;
 302                 /* we're using struct nlattr which has 16bit nla_len */
 303                 if (range > 0xffff)
 304                         queue->copy_range = 0xffff;
 305                 else
 306                         queue->copy_range = range;
 307                 break;
 308
 309         default:
 310                 status = -EINVAL;
 311
 312         }
 313         return status;
 314 }
 315
 316 static struct nfqnl_queue_entry *
 317 find_dequeue_entry(struct nfqnl_instance *queue,
 318                          nfqnl_cmpfn cmpfn, unsigned long data)
 319 {
 320         struct nfqnl_queue_entry *entry;
 321
 322         spin_lock_bh(&queue->lock);
 323         entry = __find_dequeue_entry(queue, cmpfn, data);
 324         spin_unlock_bh(&queue->lock);
 325
 326         return entry;
 327 }
 328
 329 static void
 330 nfqnl_flush(struct nfqnl_instance *queue, int verdict)
 331 {
 332         spin_lock_bh(&queue->lock);
 333         __nfqnl_flush(queue, verdict);
 334         spin_unlock_bh(&queue->lock);
 335 }
 336
 337 static struct sk_buff *
 338 nfqnl_build_packet_message(struct nfqnl_instance *queue,
 339                            struct nfqnl_queue_entry *entry, int *errp)
 340 {
 341         sk_buff_data_t old_tail;
 342         size_t size;
 343         size_t data_len = 0;
 344         struct sk_buff *skb;
 345         struct nfqnl_msg_packet_hdr pmsg;
 346         struct nlmsghdr *nlh;
 347         struct nfgenmsg *nfmsg;
 348         struct nf_info *entinf = entry->info;
 349         struct sk_buff *entskb = entry->skb;
 350         struct net_device *indev;
 351         struct net_device *outdev;
 352         __be32 tmp_uint;
 353
 354         QDEBUG("entered\n");
 355
 356         size =    NLMSG_ALIGN(sizeof(struct nfgenmsg))
 357                 + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
 358                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 359                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 360 #ifdef CONFIG_BRIDGE_NETFILTER
 361                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 362                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 363 #endif
 364                 + nla_total_size(sizeof(u_int32_t))     /* mark */
 365                 + nla_total_size(sizeof(struct nfqnl_msg_packet_hw))
 366                 + nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp));
 367
 368         outdev = entinf->outdev;
 369
 370         spin_lock_bh(&queue->lock);
 371
 372         switch (queue->copy_mode) {
 373         case NFQNL_COPY_META:
 374         case NFQNL_COPY_NONE:
 375                 data_len = 0;
 376                 break;
 377
 378         case NFQNL_COPY_PACKET:
 379                 if ((entskb->ip_summed == CHECKSUM_PARTIAL ||
 380                      entskb->ip_summed == CHECKSUM_COMPLETE) &&
 381                     (*errp = skb_checksum_help(entskb))) {
 382                         spin_unlock_bh(&queue->lock);
 383                         return NULL;
 384                 }
 385                 if (queue->copy_range == 0
 386                     || queue->copy_range > entskb->len)
 387                         data_len = entskb->len;
 388                 else
 389                         data_len = queue->copy_range;
 390
 391                 size += nla_total_size(data_len);
 392                 break;
 393
 394         default:
 395                 *errp = -EINVAL;
 396                 spin_unlock_bh(&queue->lock);
 397                 return NULL;
 398         }
 399
 400         spin_unlock_bh(&queue->lock);
 401
 402         skb = alloc_skb(size, GFP_ATOMIC);
 403         if (!skb)
 404                 goto nlmsg_failure;
 405
 406         old_tail = skb->tail;
 407         nlh = NLMSG_PUT(skb, 0, 0,
 408                         NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET,
 409                         sizeof(struct nfgenmsg));
 410         nfmsg = NLMSG_DATA(nlh);
 411         nfmsg->nfgen_family = entinf->pf;
 412         nfmsg->version = NFNETLINK_V0;
 413         nfmsg->res_id = htons(queue->queue_num);
 414
 415         pmsg.packet_id          = htonl(entry->id);
 416         pmsg.hw_protocol        = entskb->protocol;
 417         pmsg.hook               = entinf->hook;
 418
 419         NLA_PUT(skb, NFQA_PACKET_HDR, sizeof(pmsg), &pmsg);
 420
 421         indev = entinf->indev;
 422         if (indev) {
 423                 tmp_uint = htonl(indev->ifindex);
 424 #ifndef CONFIG_BRIDGE_NETFILTER
 425                 NLA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint), &tmp_uint);
 426 #else
 427                 if (entinf->pf == PF_BRIDGE) {
 428                         /* Case 1: indev is physical input device, we need to
 429                          * look for bridge group (when called from
 430                          * netfilter_bridge) */
 431                         NLA_PUT(skb, NFQA_IFINDEX_PHYSINDEV, sizeof(tmp_uint),
 432                                 &tmp_uint);
 433                         /* this is the bridge group "brX" */
 434                         tmp_uint = htonl(indev->br_port->br->dev->ifindex);
 435                         NLA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint),
 436                                 &tmp_uint);
 437                 } else {
 438                         /* Case 2: indev is bridge group, we need to look for
 439                          * physical device (when called from ipv4) */
 440                         NLA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint),
 441                                 &tmp_uint);
 442                         if (entskb->nf_bridge
 443                             && entskb->nf_bridge->physindev) {
 444                                 tmp_uint = htonl(entskb->nf_bridge->physindev->ifindex);
 445                                 NLA_PUT(skb, NFQA_IFINDEX_PHYSINDEV,
 446                                         sizeof(tmp_uint), &tmp_uint);
 447                         }
 448                 }
 449 #endif
 450         }
 451
 452         if (outdev) {
 453                 tmp_uint = htonl(outdev->ifindex);
 454 #ifndef CONFIG_BRIDGE_NETFILTER
 455                 NLA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint), &tmp_uint);
 456 #else
 457                 if (entinf->pf == PF_BRIDGE) {
 458                         /* Case 1: outdev is physical output device, we need to
 459                          * look for bridge group (when called from
 460                          * netfilter_bridge) */
 461                         NLA_PUT(skb, NFQA_IFINDEX_PHYSOUTDEV, sizeof(tmp_uint),
 462                                 &tmp_uint);
 463                         /* this is the bridge group "brX" */
 464                         tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
 465                         NLA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint),
 466                                 &tmp_uint);
 467                 } else {
 468                         /* Case 2: outdev is bridge group, we need to look for
 469                          * physical output device (when called from ipv4) */
 470                         NLA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint),
 471                                 &tmp_uint);
 472                         if (entskb->nf_bridge
 473                             && entskb->nf_bridge->physoutdev) {
 474                                 tmp_uint = htonl(entskb->nf_bridge->physoutdev->ifindex);
 475                                 NLA_PUT(skb, NFQA_IFINDEX_PHYSOUTDEV,
 476                                         sizeof(tmp_uint), &tmp_uint);
 477                         }
 478                 }
 479 #endif
 480         }
 481
 482         if (entskb->mark) {
 483                 tmp_uint = htonl(entskb->mark);
 484                 NLA_PUT(skb, NFQA_MARK, sizeof(u_int32_t), &tmp_uint);
 485         }
 486
 487         if (indev && entskb->dev) {
 488                 struct nfqnl_msg_packet_hw phw;
 489                 int len = dev_parse_header(entskb, phw.hw_addr);
 490                 if (len) {
 491                         phw.hw_addrlen = htons(len);
 492                         NLA_PUT(skb, NFQA_HWADDR, sizeof(phw), &phw);
 493                 }
 494         }
 495
 496         if (entskb->tstamp.tv64) {
 497                 struct nfqnl_msg_packet_timestamp ts;
 498                 struct timeval tv = ktime_to_timeval(entskb->tstamp);
 499                 ts.sec = cpu_to_be64(tv.tv_sec);
 500                 ts.usec = cpu_to_be64(tv.tv_usec);
 501
 502                 NLA_PUT(skb, NFQA_TIMESTAMP, sizeof(ts), &ts);
 503         }
 504
 505         if (data_len) {
 506                 struct nlattr *nla;
 507                 int size = nla_attr_size(data_len);
 508
 509                 if (skb_tailroom(skb) < nla_total_size(data_len)) {
 510                         printk(KERN_WARNING "nf_queue: no tailroom!\n");
 511                         goto nlmsg_failure;
 512                 }
 513
 514                 nla = (struct nlattr *)skb_put(skb, nla_total_size(data_len));
 515                 nla->nla_type = NFQA_PAYLOAD;
 516                 nla->nla_len = size;
 517
 518                 if (skb_copy_bits(entskb, 0, nla_data(nla), data_len))
 519                         BUG();
 520         }
 521
 522         nlh->nlmsg_len = skb->tail - old_tail;
 523         return skb;
 524
 525 nlmsg_failure:
 526 nla_put_failure:
 527         if (skb)
 528                 kfree_skb(skb);
 529         *errp = -EINVAL;
 530         if (net_ratelimit())
 531                 printk(KERN_ERR "nf_queue: error creating packet message\n");
 532         return NULL;
 533 }
 534
 535 static int
 536 nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
 537                      unsigned int queuenum, void *data)
 538 {
 539         int status = -EINVAL;
 540         struct sk_buff *nskb;
 541         struct nfqnl_instance *queue;
 542         struct nfqnl_queue_entry *entry;
 543
 544         QDEBUG("entered\n");
 545
 546         queue = instance_lookup_get(queuenum);
 547         if (!queue) {
 548                 QDEBUG("no queue instance matching\n");
 549                 return -EINVAL;
 550         }
 551
 552         if (queue->copy_mode == NFQNL_COPY_NONE) {
 553                 QDEBUG("mode COPY_NONE, aborting\n");
 554                 status = -EAGAIN;
 555                 goto err_out_put;
 556         }
 557
 558         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 559         if (entry == NULL) {
 560                 if (net_ratelimit())
 561                         printk(KERN_ERR
 562                                 "nf_queue: OOM in nfqnl_enqueue_packet()\n");
 563                 status = -ENOMEM;
 564                 goto err_out_put;
 565         }
 566
 567         entry->info = info;
 568         entry->skb = skb;
 569         entry->id = atomic_inc_return(&queue->id_sequence);
 570
 571         nskb = nfqnl_build_packet_message(queue, entry, &status);
 572         if (nskb == NULL)
 573                 goto err_out_free;
 574
 575         spin_lock_bh(&queue->lock);
 576
 577         if (!queue->peer_pid)
 578                 goto err_out_free_nskb;
 579
 580         if (queue->queue_total >= queue->queue_maxlen) {
 581                 queue->queue_dropped++;
 582                 status = -ENOSPC;
 583                 if (net_ratelimit())
 584                           printk(KERN_WARNING "nf_queue: full at %d entries, "
 585                                  "dropping packets(s). Dropped: %d\n",
 586                                  queue->queue_total, queue->queue_dropped);
 587                 goto err_out_free_nskb;
 588         }
 589
 590         /* nfnetlink_unicast will either free the nskb or add it to a socket */
 591         status = nfnetlink_unicast(nskb, queue->peer_pid, MSG_DONTWAIT);
 592         if (status < 0) {
 593                 queue->queue_user_dropped++;
 594                 goto err_out_unlock;
 595         }
 596
 597         __enqueue_entry(queue, entry);
 598
 599         spin_unlock_bh(&queue->lock);
 600         instance_put(queue);
 601         return status;
 602
 603 err_out_free_nskb:
 604         kfree_skb(nskb);
 605
 606 err_out_unlock:
 607         spin_unlock_bh(&queue->lock);
 608
 609 err_out_free:
 610         kfree(entry);
 611 err_out_put:
 612         instance_put(queue);
 613         return status;
 614 }
 615
 616 static int
 617 nfqnl_mangle(void *data, int data_len, struct nfqnl_queue_entry *e)
 618 {
 619         int diff;
 620         int err;
 621
 622         diff = data_len - e->skb->len;
 623         if (diff < 0) {
 624                 if (pskb_trim(e->skb, data_len))
 625                         return -ENOMEM;
 626         } else if (diff > 0) {
 627                 if (data_len > 0xFFFF)
 628                         return -EINVAL;
 629                 if (diff > skb_tailroom(e->skb)) {
 630                         err = pskb_expand_head(e->skb, 0,
 631                                                diff - skb_tailroom(e->skb),
 632                                                GFP_ATOMIC);
 633                         if (err) {
 634                                 printk(KERN_WARNING "nf_queue: OOM "
 635                                       "in mangle, dropping packet\n");
 636                                 return err;
 637                         }
 638                 }
 639                 skb_put(e->skb, diff);
 640         }
 641         if (!skb_make_writable(e->skb, data_len))
 642                 return -ENOMEM;
 643         skb_copy_to_linear_data(e->skb, data, data_len);
 644         e->skb->ip_summed = CHECKSUM_NONE;
 645         return 0;
 646 }
 647
 648 static inline int
 649 id_cmp(struct nfqnl_queue_entry *e, unsigned long id)
 650 {
 651         return (id == e->id);
 652 }
 653
 654 static int
 655 nfqnl_set_mode(struct nfqnl_instance *queue,
 656                unsigned char mode, unsigned int range)
 657 {
 658         int status;
 659
 660         spin_lock_bh(&queue->lock);
 661         status = __nfqnl_set_mode(queue, mode, range);
 662         spin_unlock_bh(&queue->lock);
 663
 664         return status;
 665 }
 666
 667 static int
 668 dev_cmp(struct nfqnl_queue_entry *entry, unsigned long ifindex)
 669 {
 670         struct nf_info *entinf = entry->info;
 671
 672         if (entinf->indev)
 673                 if (entinf->indev->ifindex == ifindex)
 674                         return 1;
 675         if (entinf->outdev)
 676                 if (entinf->outdev->ifindex == ifindex)
 677                         return 1;
 678 #ifdef CONFIG_BRIDGE_NETFILTER
 679         if (entry->skb->nf_bridge) {
 680                 if (entry->skb->nf_bridge->physindev &&
 681                     entry->skb->nf_bridge->physindev->ifindex == ifindex)
 682                         return 1;
 683                 if (entry->skb->nf_bridge->physoutdev &&
 684                     entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
 685                         return 1;
 686         }
 687 #endif
 688         return 0;
 689 }
 690
 691 /* drop all packets with either indev or outdev == ifindex from all queue
 692  * instances */
 693 static void
 694 nfqnl_dev_drop(int ifindex)
 695 {
 696         int i;
 697
 698         QDEBUG("entering for ifindex %u\n", ifindex);
 699
 700         /* this only looks like we have to hold the readlock for a way too long
 701          * time, issue_verdict(),  nf_reinject(), ... - but we always only
 702          * issue NF_DROP, which is processed directly in nf_reinject() */
 703         read_lock_bh(&instances_lock);
 704
 705         for  (i = 0; i < INSTANCE_BUCKETS; i++) {
 706                 struct hlist_node *tmp;
 707                 struct nfqnl_instance *inst;
 708                 struct hlist_head *head = &instance_table[i];
 709
 710                 hlist_for_each_entry(inst, tmp, head, hlist) {
 711                         struct nfqnl_queue_entry *entry;
 712                         while ((entry = find_dequeue_entry(inst, dev_cmp,
 713                                                            ifindex)) != NULL)
 714                                 issue_verdict(entry, NF_DROP);
 715                 }
 716         }
 717
 718         read_unlock_bh(&instances_lock);
 719 }
 720
 721 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 722
 723 static int
 724 nfqnl_rcv_dev_event(struct notifier_block *this,
 725                     unsigned long event, void *ptr)
 726 {
 727         struct net_device *dev = ptr;
 728
 729         if (dev->nd_net != &init_net)
 730                 return NOTIFY_DONE;
 731
 732         /* Drop any packets associated with the downed device */
 733         if (event == NETDEV_DOWN)
 734                 nfqnl_dev_drop(dev->ifindex);
 735         return NOTIFY_DONE;
 736 }
 737
 738 static struct notifier_block nfqnl_dev_notifier = {
 739         .notifier_call  = nfqnl_rcv_dev_event,
 740 };
 741
 742 static int
 743 nfqnl_rcv_nl_event(struct notifier_block *this,
 744                    unsigned long event, void *ptr)
 745 {
 746         struct netlink_notify *n = ptr;
 747
 748         if (event == NETLINK_URELEASE &&
 749             n->protocol == NETLINK_NETFILTER && n->pid) {
 750                 int i;
 751
 752                 /* destroy all instances for this pid */
 753                 write_lock_bh(&instances_lock);
 754                 for  (i = 0; i < INSTANCE_BUCKETS; i++) {
 755                         struct hlist_node *tmp, *t2;
 756                         struct nfqnl_instance *inst;
 757                         struct hlist_head *head = &instance_table[i];
 758
 759                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
 760                                 if ((n->net == &init_net) &&
 761                                     (n->pid == inst->peer_pid))
 762                                         __instance_destroy(inst);
 763                         }
 764                 }
 765                 write_unlock_bh(&instances_lock);
 766         }
 767         return NOTIFY_DONE;
 768 }
 769
 770 static struct notifier_block nfqnl_rtnl_notifier = {
 771         .notifier_call  = nfqnl_rcv_nl_event,
 772 };
 773
 774 static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = {
 775         [NFQA_VERDICT_HDR]      = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
 776         [NFQA_MARK]             = { .type = NLA_U32 },
 777         [NFQA_PAYLOAD]          = { .type = NLA_UNSPEC },
 778 };
 779
 780 static int
 781 nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
 782                    struct nlmsghdr *nlh, struct nlattr *nfqa[])
 783 {
 784         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 785         u_int16_t queue_num = ntohs(nfmsg->res_id);
 786
 787         struct nfqnl_msg_verdict_hdr *vhdr;
 788         struct nfqnl_instance *queue;
 789         unsigned int verdict;
 790         struct nfqnl_queue_entry *entry;
 791         int err;
 792
 793         queue = instance_lookup_get(queue_num);
 794         if (!queue)
 795                 return -ENODEV;
 796
 797         if (queue->peer_pid != NETLINK_CB(skb).pid) {
 798                 err = -EPERM;
 799                 goto err_out_put;
 800         }
 801
 802         if (!nfqa[NFQA_VERDICT_HDR]) {
 803                 err = -EINVAL;
 804                 goto err_out_put;
 805         }
 806
 807         vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
 808         verdict = ntohl(vhdr->verdict);
 809
 810         if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) {
 811                 err = -EINVAL;
 812                 goto err_out_put;
 813         }
 814
 815         entry = find_dequeue_entry(queue, id_cmp, ntohl(vhdr->id));
 816         if (entry == NULL) {
 817                 err = -ENOENT;
 818                 goto err_out_put;
 819         }
 820
 821         if (nfqa[NFQA_PAYLOAD]) {
 822                 if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
 823                                  nla_len(nfqa[NFQA_PAYLOAD]), entry) < 0)
 824                         verdict = NF_DROP;
 825         }
 826
 827         if (nfqa[NFQA_MARK])
 828                 entry->skb->mark = ntohl(*(__be32 *)
 829                                          nla_data(nfqa[NFQA_MARK]));
 830
 831         issue_verdict(entry, verdict);
 832         instance_put(queue);
 833         return 0;
 834
 835 err_out_put:
 836         instance_put(queue);
 837         return err;
 838 }
 839
 840 static int
 841 nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
 842                   struct nlmsghdr *nlh, struct nlattr *nfqa[])
 843 {
 844         return -ENOTSUPP;
 845 }
 846
 847 static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
 848         [NFQA_CFG_CMD]          = { .len = sizeof(struct nfqnl_msg_config_cmd) },
 849         [NFQA_CFG_PARAMS]       = { .len = sizeof(struct nfqnl_msg_config_params) },
 850 };
 851
 852 static struct nf_queue_handler nfqh = {
 853         .name   = "nf_queue",
 854         .outfn  = &nfqnl_enqueue_packet,
 855 };
 856
 857 static int
 858 nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 859                   struct nlmsghdr *nlh, struct nlattr *nfqa[])
 860 {
 861         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 862         u_int16_t queue_num = ntohs(nfmsg->res_id);
 863         struct nfqnl_instance *queue;
 864         int ret = 0;
 865
 866         QDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
 867
 868         queue = instance_lookup_get(queue_num);
 869         if (nfqa[NFQA_CFG_CMD]) {
 870                 struct nfqnl_msg_config_cmd *cmd;
 871                 cmd = nla_data(nfqa[NFQA_CFG_CMD]);
 872                 QDEBUG("found CFG_CMD\n");
 873
 874                 switch (cmd->command) {
 875                 case NFQNL_CFG_CMD_BIND:
 876                         if (queue)
 877                                 return -EBUSY;
 878
 879                         queue = instance_create(queue_num, NETLINK_CB(skb).pid);
 880                         if (!queue)
 881                                 return -EINVAL;
 882                         break;
 883                 case NFQNL_CFG_CMD_UNBIND:
 884                         if (!queue)
 885                                 return -ENODEV;
 886
 887                         if (queue->peer_pid != NETLINK_CB(skb).pid) {
 888                                 ret = -EPERM;
 889                                 goto out_put;
 890                         }
 891
 892                         instance_destroy(queue);
 893                         break;
 894                 case NFQNL_CFG_CMD_PF_BIND:
 895                         QDEBUG("registering queue handler for pf=%u\n",
 896                                 ntohs(cmd->pf));
 897                         ret = nf_register_queue_handler(ntohs(cmd->pf), &nfqh);
 898                         break;
 899                 case NFQNL_CFG_CMD_PF_UNBIND:
 900                         QDEBUG("unregistering queue handler for pf=%u\n",
 901                                 ntohs(cmd->pf));
 902                         ret = nf_unregister_queue_handler(ntohs(cmd->pf), &nfqh);
 903                         break;
 904                 default:
 905                         ret = -EINVAL;
 906                         break;
 907                 }
 908         } else {
 909                 if (!queue) {
 910                         QDEBUG("no config command, and no instance ENOENT\n");
 911                         ret = -ENOENT;
 912                         goto out_put;
 913                 }
 914
 915                 if (queue->peer_pid != NETLINK_CB(skb).pid) {
 916                         QDEBUG("no config command, and wrong pid\n");
 917                         ret = -EPERM;
 918                         goto out_put;
 919                 }
 920         }
 921
 922         if (nfqa[NFQA_CFG_PARAMS]) {
 923                 struct nfqnl_msg_config_params *params;
 924
 925                 if (!queue) {
 926                         ret = -ENOENT;
 927                         goto out_put;
 928                 }
 929                 params = nla_data(nfqa[NFQA_CFG_PARAMS]);
 930                 nfqnl_set_mode(queue, params->copy_mode,
 931                                 ntohl(params->copy_range));
 932         }
 933
 934         if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
 935                 __be32 *queue_maxlen;
 936                 queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
 937                 spin_lock_bh(&queue->lock);
 938                 queue->queue_maxlen = ntohl(*queue_maxlen);
 939                 spin_unlock_bh(&queue->lock);
 940         }
 941
 942 out_put:
 943         instance_put(queue);
 944         return ret;
 945 }
 946
 947 static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
 948         [NFQNL_MSG_PACKET]      = { .call = nfqnl_recv_unsupp,
 949                                     .attr_count = NFQA_MAX, },
 950         [NFQNL_MSG_VERDICT]     = { .call = nfqnl_recv_verdict,
 951                                     .attr_count = NFQA_MAX,
 952                                     .policy = nfqa_verdict_policy },
 953         [NFQNL_MSG_CONFIG]      = { .call = nfqnl_recv_config,
 954                                     .attr_count = NFQA_CFG_MAX,
 955                                     .policy = nfqa_cfg_policy },
 956 };
 957
 958 static const struct nfnetlink_subsystem nfqnl_subsys = {
 959         .name           = "nf_queue",
 960         .subsys_id      = NFNL_SUBSYS_QUEUE,
 961         .cb_count       = NFQNL_MSG_MAX,
 962         .cb             = nfqnl_cb,
 963 };
 964
 965 #ifdef CONFIG_PROC_FS
 966 struct iter_state {
 967         unsigned int bucket;
 968 };
 969
 970 static struct hlist_node *get_first(struct seq_file *seq)
 971 {
 972         struct iter_state *st = seq->private;
 973
 974         if (!st)
 975                 return NULL;
 976
 977         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
 978                 if (!hlist_empty(&instance_table[st->bucket]))
 979                         return instance_table[st->bucket].first;
 980         }
 981         return NULL;
 982 }
 983
 984 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
 985 {
 986         struct iter_state *st = seq->private;
 987
 988         h = h->next;
 989         while (!h) {
 990                 if (++st->bucket >= INSTANCE_BUCKETS)
 991                         return NULL;
 992
 993                 h = instance_table[st->bucket].first;
 994         }
 995         return h;
 996 }
 997
 998 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
 999 {
1000         struct hlist_node *head;
1001         head = get_first(seq);
1002
1003         if (head)
1004                 while (pos && (head = get_next(seq, head)))
1005                         pos--;
1006         return pos ? NULL : head;
1007 }
1008
1009 static void *seq_start(struct seq_file *seq, loff_t *pos)
1010 {
1011         read_lock_bh(&instances_lock);
1012         return get_idx(seq, *pos);
1013 }
1014
1015 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1016 {
1017         (*pos)++;
1018         return get_next(s, v);
1019 }
1020
1021 static void seq_stop(struct seq_file *s, void *v)
1022 {
1023         read_unlock_bh(&instances_lock);
1024 }
1025
1026 static int seq_show(struct seq_file *s, void *v)
1027 {
1028         const struct nfqnl_instance *inst = v;
1029
1030         return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n",
1031                           inst->queue_num,
1032                           inst->peer_pid, inst->queue_total,
1033                           inst->copy_mode, inst->copy_range,
1034                           inst->queue_dropped, inst->queue_user_dropped,
1035                           atomic_read(&inst->id_sequence),
1036                           atomic_read(&inst->use));
1037 }
1038
1039 static const struct seq_operations nfqnl_seq_ops = {
1040         .start  = seq_start,
1041         .next   = seq_next,
1042         .stop   = seq_stop,
1043         .show   = seq_show,
1044 };
1045
1046 static int nfqnl_open(struct inode *inode, struct file *file)
1047 {
1048         return seq_open_private(file, &nfqnl_seq_ops,
1049                         sizeof(struct iter_state));
1050 }
1051
1052 static const struct file_operations nfqnl_file_ops = {
1053         .owner   = THIS_MODULE,
1054         .open    = nfqnl_open,
1055         .read    = seq_read,
1056         .llseek  = seq_lseek,
1057         .release = seq_release_private,
1058 };
1059
1060 #endif /* PROC_FS */
1061
1062 static int __init nfnetlink_queue_init(void)
1063 {
1064         int i, status = -ENOMEM;
1065 #ifdef CONFIG_PROC_FS
1066         struct proc_dir_entry *proc_nfqueue;
1067 #endif
1068
1069         for (i = 0; i < INSTANCE_BUCKETS; i++)
1070                 INIT_HLIST_HEAD(&instance_table[i]);
1071
1072         netlink_register_notifier(&nfqnl_rtnl_notifier);
1073         status = nfnetlink_subsys_register(&nfqnl_subsys);
1074         if (status < 0) {
1075                 printk(KERN_ERR "nf_queue: failed to create netlink socket\n");
1076                 goto cleanup_netlink_notifier;
1077         }
1078
1079 #ifdef CONFIG_PROC_FS
1080         proc_nfqueue = create_proc_entry("nfnetlink_queue", 0440,
1081                                          proc_net_netfilter);
1082         if (!proc_nfqueue)
1083                 goto cleanup_subsys;
1084         proc_nfqueue->proc_fops = &nfqnl_file_ops;
1085 #endif
1086
1087         register_netdevice_notifier(&nfqnl_dev_notifier);
1088         return status;
1089
1090 #ifdef CONFIG_PROC_FS
1091 cleanup_subsys:
1092         nfnetlink_subsys_unregister(&nfqnl_subsys);
1093 #endif
1094 cleanup_netlink_notifier:
1095         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1096         return status;
1097 }
1098
1099 static void __exit nfnetlink_queue_fini(void)
1100 {
1101         nf_unregister_queue_handlers(&nfqh);
1102         unregister_netdevice_notifier(&nfqnl_dev_notifier);
1103 #ifdef CONFIG_PROC_FS
1104         remove_proc_entry("nfnetlink_queue", proc_net_netfilter);
1105 #endif
1106         nfnetlink_subsys_unregister(&nfqnl_subsys);
1107         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1108 }
1109
1110 MODULE_DESCRIPTION("netfilter packet queue handler");
1111 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1112 MODULE_LICENSE("GPL");
1113 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1114
1115 module_init(nfnetlink_queue_init);
1116 module_exit(nfnetlink_queue_fini);