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         inst->lock = SPIN_LOCK_UNLOCKED;
 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 nfattr which has 16bit nfa_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         unsigned char *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         unsigned int tmp_uint;
 349
 350         QDEBUG("entered\n");
 351
 352         /* all macros expand to constant values at compile time */
 353         size =    NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hdr))
 354                 + NLMSG_SPACE(sizeof(u_int32_t))        /* ifindex */
 355                 + NLMSG_SPACE(sizeof(u_int32_t))        /* ifindex */
 356 #ifdef CONFIG_BRIDGE_NETFILTER
 357                 + NLMSG_SPACE(sizeof(u_int32_t))        /* ifindex */
 358                 + NLMSG_SPACE(sizeof(u_int32_t))        /* ifindex */
 359 #endif
 360                 + NLMSG_SPACE(sizeof(u_int32_t))        /* mark */
 361                 + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hw))
 362                 + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_timestamp));
 363
 364         spin_lock_bh(&queue->lock);
 365
 366         switch (queue->copy_mode) {
 367         case NFQNL_COPY_META:
 368         case NFQNL_COPY_NONE:
 369                 data_len = 0;
 370                 break;
 371
 372         case NFQNL_COPY_PACKET:
 373                 if (entry->skb->ip_summed == CHECKSUM_HW &&
 374                     (*errp = skb_checksum_help(entry->skb,
 375                                                entry->info->outdev == NULL))) {
 376                         spin_unlock_bh(&queue->lock);
 377                         return NULL;
 378                 }
 379                 if (queue->copy_range == 0
 380                     || queue->copy_range > entry->skb->len)
 381                         data_len = entry->skb->len;
 382                 else
 383                         data_len = queue->copy_range;
 384
 385                 size += NLMSG_SPACE(data_len);
 386                 break;
 387
 388         default:
 389                 *errp = -EINVAL;
 390                 spin_unlock_bh(&queue->lock);
 391                 return NULL;
 392         }
 393
 394         spin_unlock_bh(&queue->lock);
 395
 396         skb = alloc_skb(size, GFP_ATOMIC);
 397         if (!skb)
 398                 goto nlmsg_failure;
 399
 400         old_tail= skb->tail;
 401         nlh = NLMSG_PUT(skb, 0, 0,
 402                         NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET,
 403                         sizeof(struct nfgenmsg));
 404         nfmsg = NLMSG_DATA(nlh);
 405         nfmsg->nfgen_family = entry->info->pf;
 406         nfmsg->version = NFNETLINK_V0;
 407         nfmsg->res_id = htons(queue->queue_num);
 408
 409         pmsg.packet_id          = htonl(entry->id);
 410         pmsg.hw_protocol        = htons(entry->skb->protocol);
 411         pmsg.hook               = entry->info->hook;
 412
 413         NFA_PUT(skb, NFQA_PACKET_HDR, sizeof(pmsg), &pmsg);
 414
 415         if (entry->info->indev) {
 416                 tmp_uint = htonl(entry->info->indev->ifindex);
 417 #ifndef CONFIG_BRIDGE_NETFILTER
 418                 NFA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint), &tmp_uint);
 419 #else
 420                 if (entry->info->pf == PF_BRIDGE) {
 421                         /* Case 1: indev is physical input device, we need to
 422                          * look for bridge group (when called from
 423                          * netfilter_bridge) */
 424                         NFA_PUT(skb, NFQA_IFINDEX_PHYSINDEV, sizeof(tmp_uint),
 425                                 &tmp_uint);
 426                         /* this is the bridge group "brX" */
 427                         tmp_uint = htonl(entry->info->indev->br_port->br->dev->ifindex);
 428                         NFA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint),
 429                                 &tmp_uint);
 430                 } else {
 431                         /* Case 2: indev is bridge group, we need to look for
 432                          * physical device (when called from ipv4) */
 433                         NFA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint),
 434                                 &tmp_uint);
 435                         if (entry->skb->nf_bridge
 436                             && entry->skb->nf_bridge->physindev) {
 437                                 tmp_uint = htonl(entry->skb->nf_bridge->physindev->ifindex);
 438                                 NFA_PUT(skb, NFQA_IFINDEX_PHYSINDEV,
 439                                         sizeof(tmp_uint), &tmp_uint);
 440                         }
 441                 }
 442 #endif
 443         }
 444
 445         if (entry->info->outdev) {
 446                 tmp_uint = htonl(entry->info->outdev->ifindex);
 447 #ifndef CONFIG_BRIDGE_NETFILTER
 448                 NFA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint), &tmp_uint);
 449 #else
 450                 if (entry->info->pf == PF_BRIDGE) {
 451                         /* Case 1: outdev is physical output device, we need to
 452                          * look for bridge group (when called from
 453                          * netfilter_bridge) */
 454                         NFA_PUT(skb, NFQA_IFINDEX_PHYSOUTDEV, sizeof(tmp_uint),
 455                                 &tmp_uint);
 456                         /* this is the bridge group "brX" */
 457                         tmp_uint = htonl(entry->info->outdev->br_port->br->dev->ifindex);
 458                         NFA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint),
 459                                 &tmp_uint);
 460                 } else {
 461                         /* Case 2: outdev is bridge group, we need to look for
 462                          * physical output device (when called from ipv4) */
 463                         NFA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint),
 464                                 &tmp_uint);
 465                         if (entry->skb->nf_bridge
 466                             && entry->skb->nf_bridge->physoutdev) {
 467                                 tmp_uint = htonl(entry->skb->nf_bridge->physoutdev->ifindex);
 468                                 NFA_PUT(skb, NFQA_IFINDEX_PHYSOUTDEV,
 469                                         sizeof(tmp_uint), &tmp_uint);
 470                         }
 471                 }
 472 #endif
 473         }
 474
 475         if (entry->skb->nfmark) {
 476                 tmp_uint = htonl(entry->skb->nfmark);
 477                 NFA_PUT(skb, NFQA_MARK, sizeof(u_int32_t), &tmp_uint);
 478         }
 479
 480         if (entry->info->indev && entry->skb->dev
 481             && entry->skb->dev->hard_header_parse) {
 482                 struct nfqnl_msg_packet_hw phw;
 483
 484                 phw.hw_addrlen =
 485                         entry->skb->dev->hard_header_parse(entry->skb,
 486                                                            phw.hw_addr);
 487                 phw.hw_addrlen = htons(phw.hw_addrlen);
 488                 NFA_PUT(skb, NFQA_HWADDR, sizeof(phw), &phw);
 489         }
 490
 491         if (entry->skb->tstamp.off_sec) {
 492                 struct nfqnl_msg_packet_timestamp ts;
 493
 494                 ts.sec = cpu_to_be64(entry->skb->tstamp.off_sec);
 495                 ts.usec = cpu_to_be64(entry->skb->tstamp.off_usec);
 496
 497                 NFA_PUT(skb, NFQA_TIMESTAMP, sizeof(ts), &ts);
 498         }
 499
 500         if (data_len) {
 501                 struct nfattr *nfa;
 502                 int size = NFA_LENGTH(data_len);
 503
 504                 if (skb_tailroom(skb) < (int)NFA_SPACE(data_len)) {
 505                         printk(KERN_WARNING "nf_queue: no tailroom!\n");
 506                         goto nlmsg_failure;
 507                 }
 508
 509                 nfa = (struct nfattr *)skb_put(skb, NFA_ALIGN(size));
 510                 nfa->nfa_type = NFQA_PAYLOAD;
 511                 nfa->nfa_len = size;
 512
 513                 if (skb_copy_bits(entry->skb, 0, NFA_DATA(nfa), data_len))
 514                         BUG();
 515         }
 516
 517         nlh->nlmsg_len = skb->tail - old_tail;
 518         return skb;
 519
 520 nlmsg_failure:
 521 nfattr_failure:
 522         if (skb)
 523                 kfree_skb(skb);
 524         *errp = -EINVAL;
 525         if (net_ratelimit())
 526                 printk(KERN_ERR "nf_queue: error creating packet message\n");
 527         return NULL;
 528 }
 529
 530 static int
 531 nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
 532                      unsigned int queuenum, void *data)
 533 {
 534         int status = -EINVAL;
 535         struct sk_buff *nskb;
 536         struct nfqnl_instance *queue;
 537         struct nfqnl_queue_entry *entry;
 538
 539         QDEBUG("entered\n");
 540
 541         queue = instance_lookup_get(queuenum);
 542         if (!queue) {
 543                 QDEBUG("no queue instance matching\n");
 544                 return -EINVAL;
 545         }
 546
 547         if (queue->copy_mode == NFQNL_COPY_NONE) {
 548                 QDEBUG("mode COPY_NONE, aborting\n");
 549                 status = -EAGAIN;
 550                 goto err_out_put;
 551         }
 552
 553         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 554         if (entry == NULL) {
 555                 if (net_ratelimit())
 556                         printk(KERN_ERR
 557                                 "nf_queue: OOM in nfqnl_enqueue_packet()\n");
 558                 status = -ENOMEM;
 559                 goto err_out_put;
 560         }
 561
 562         entry->info = info;
 563         entry->skb = skb;
 564         entry->id = atomic_inc_return(&queue->id_sequence);
 565
 566         nskb = nfqnl_build_packet_message(queue, entry, &status);
 567         if (nskb == NULL)
 568                 goto err_out_free;
 569
 570         spin_lock_bh(&queue->lock);
 571
 572         if (!queue->peer_pid)
 573                 goto err_out_free_nskb;
 574
 575         if (queue->queue_total >= queue->queue_maxlen) {
 576                 queue->queue_dropped++;
 577                 status = -ENOSPC;
 578                 if (net_ratelimit())
 579                           printk(KERN_WARNING "ip_queue: full at %d entries, "
 580                                  "dropping packets(s). Dropped: %d\n",
 581                                  queue->queue_total, queue->queue_dropped);
 582                 goto err_out_free_nskb;
 583         }
 584
 585         /* nfnetlink_unicast will either free the nskb or add it to a socket */
 586         status = nfnetlink_unicast(nskb, queue->peer_pid, MSG_DONTWAIT);
 587         if (status < 0) {
 588                 queue->queue_user_dropped++;
 589                 goto err_out_unlock;
 590         }
 591
 592         __enqueue_entry(queue, entry);
 593
 594         spin_unlock_bh(&queue->lock);
 595         instance_put(queue);
 596         return status;
 597
 598 err_out_free_nskb:
 599         kfree_skb(nskb);
 600
 601 err_out_unlock:
 602         spin_unlock_bh(&queue->lock);
 603
 604 err_out_free:
 605         kfree(entry);
 606 err_out_put:
 607         instance_put(queue);
 608         return status;
 609 }
 610
 611 static int
 612 nfqnl_mangle(void *data, int data_len, struct nfqnl_queue_entry *e)
 613 {
 614         int diff;
 615
 616         diff = data_len - e->skb->len;
 617         if (diff < 0)
 618                 skb_trim(e->skb, data_len);
 619         else if (diff > 0) {
 620                 if (data_len > 0xFFFF)
 621                         return -EINVAL;
 622                 if (diff > skb_tailroom(e->skb)) {
 623                         struct sk_buff *newskb;
 624
 625                         newskb = skb_copy_expand(e->skb,
 626                                                  skb_headroom(e->skb),
 627                                                  diff,
 628                                                  GFP_ATOMIC);
 629                         if (newskb == NULL) {
 630                                 printk(KERN_WARNING "ip_queue: OOM "
 631                                       "in mangle, dropping packet\n");
 632                                 return -ENOMEM;
 633                         }
 634                         if (e->skb->sk)
 635                                 skb_set_owner_w(newskb, e->skb->sk);
 636                         kfree_skb(e->skb);
 637                         e->skb = newskb;
 638                 }
 639                 skb_put(e->skb, diff);
 640         }
 641         if (!skb_make_writable(&e->skb, data_len))
 642                 return -ENOMEM;
 643         memcpy(e->skb->data, 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         if (entry->info->indev)
 671                 if (entry->info->indev->ifindex == ifindex)
 672                         return 1;
 673
 674         if (entry->info->outdev)
 675                 if (entry->info->outdev->ifindex == ifindex)
 676                         return 1;
 677
 678         return 0;
 679 }
 680
 681 /* drop all packets with either indev or outdev == ifindex from all queue
 682  * instances */
 683 static void
 684 nfqnl_dev_drop(int ifindex)
 685 {
 686         int i;
 687
 688         QDEBUG("entering for ifindex %u\n", ifindex);
 689
 690         /* this only looks like we have to hold the readlock for a way too long
 691          * time, issue_verdict(),  nf_reinject(), ... - but we always only
 692          * issue NF_DROP, which is processed directly in nf_reinject() */
 693         read_lock_bh(&instances_lock);
 694
 695         for  (i = 0; i < INSTANCE_BUCKETS; i++) {
 696                 struct hlist_node *tmp;
 697                 struct nfqnl_instance *inst;
 698                 struct hlist_head *head = &instance_table[i];
 699
 700                 hlist_for_each_entry(inst, tmp, head, hlist) {
 701                         struct nfqnl_queue_entry *entry;
 702                         while ((entry = find_dequeue_entry(inst, dev_cmp,
 703                                                            ifindex)) != NULL)
 704                                 issue_verdict(entry, NF_DROP);
 705                 }
 706         }
 707
 708         read_unlock_bh(&instances_lock);
 709 }
 710
 711 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 712
 713 static int
 714 nfqnl_rcv_dev_event(struct notifier_block *this,
 715                     unsigned long event, void *ptr)
 716 {
 717         struct net_device *dev = ptr;
 718
 719         /* Drop any packets associated with the downed device */
 720         if (event == NETDEV_DOWN)
 721                 nfqnl_dev_drop(dev->ifindex);
 722         return NOTIFY_DONE;
 723 }
 724
 725 static struct notifier_block nfqnl_dev_notifier = {
 726         .notifier_call  = nfqnl_rcv_dev_event,
 727 };
 728
 729 static int
 730 nfqnl_rcv_nl_event(struct notifier_block *this,
 731                    unsigned long event, void *ptr)
 732 {
 733         struct netlink_notify *n = ptr;
 734
 735         if (event == NETLINK_URELEASE &&
 736             n->protocol == NETLINK_NETFILTER && n->pid) {
 737                 int i;
 738
 739                 /* destroy all instances for this pid */
 740                 write_lock_bh(&instances_lock);
 741                 for  (i = 0; i < INSTANCE_BUCKETS; i++) {
 742                         struct hlist_node *tmp, *t2;
 743                         struct nfqnl_instance *inst;
 744                         struct hlist_head *head = &instance_table[i];
 745
 746                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
 747                                 if (n->pid == inst->peer_pid)
 748                                         __instance_destroy(inst);
 749                         }
 750                 }
 751                 write_unlock_bh(&instances_lock);
 752         }
 753         return NOTIFY_DONE;
 754 }
 755
 756 static struct notifier_block nfqnl_rtnl_notifier = {
 757         .notifier_call  = nfqnl_rcv_nl_event,
 758 };
 759
 760 static const int nfqa_verdict_min[NFQA_MAX] = {
 761         [NFQA_VERDICT_HDR-1]    = sizeof(struct nfqnl_msg_verdict_hdr),
 762         [NFQA_MARK-1]           = sizeof(u_int32_t),
 763         [NFQA_PAYLOAD-1]        = 0,
 764 };
 765
 766 static int
 767 nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
 768                    struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
 769 {
 770         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 771         u_int16_t queue_num = ntohs(nfmsg->res_id);
 772
 773         struct nfqnl_msg_verdict_hdr *vhdr;
 774         struct nfqnl_instance *queue;
 775         unsigned int verdict;
 776         struct nfqnl_queue_entry *entry;
 777         int err;
 778
 779         if (nfattr_bad_size(nfqa, NFQA_MAX, nfqa_verdict_min)) {
 780                 QDEBUG("bad attribute size\n");
 781                 return -EINVAL;
 782         }
 783
 784         queue = instance_lookup_get(queue_num);
 785         if (!queue)
 786                 return -ENODEV;
 787
 788         if (queue->peer_pid != NETLINK_CB(skb).pid) {
 789                 err = -EPERM;
 790                 goto err_out_put;
 791         }
 792
 793         if (!nfqa[NFQA_VERDICT_HDR-1]) {
 794                 err = -EINVAL;
 795                 goto err_out_put;
 796         }
 797
 798         vhdr = NFA_DATA(nfqa[NFQA_VERDICT_HDR-1]);
 799         verdict = ntohl(vhdr->verdict);
 800
 801         if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) {
 802                 err = -EINVAL;
 803                 goto err_out_put;
 804         }
 805
 806         entry = find_dequeue_entry(queue, id_cmp, ntohl(vhdr->id));
 807         if (entry == NULL) {
 808                 err = -ENOENT;
 809                 goto err_out_put;
 810         }
 811
 812         if (nfqa[NFQA_PAYLOAD-1]) {
 813                 if (nfqnl_mangle(NFA_DATA(nfqa[NFQA_PAYLOAD-1]),
 814                                  NFA_PAYLOAD(nfqa[NFQA_PAYLOAD-1]), entry) < 0)
 815                         verdict = NF_DROP;
 816         }
 817
 818         if (nfqa[NFQA_MARK-1])
 819                 skb->nfmark = ntohl(*(u_int32_t *)NFA_DATA(nfqa[NFQA_MARK-1]));
 820
 821         issue_verdict(entry, verdict);
 822         instance_put(queue);
 823         return 0;
 824
 825 err_out_put:
 826         instance_put(queue);
 827         return err;
 828 }
 829
 830 static int
 831 nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
 832                   struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
 833 {
 834         return -ENOTSUPP;
 835 }
 836
 837 static const int nfqa_cfg_min[NFQA_CFG_MAX] = {
 838         [NFQA_CFG_CMD-1]        = sizeof(struct nfqnl_msg_config_cmd),
 839         [NFQA_CFG_PARAMS-1]     = sizeof(struct nfqnl_msg_config_params),
 840 };
 841
 842 static struct nf_queue_handler nfqh = {
 843         .name   = "nf_queue",
 844         .outfn  = &nfqnl_enqueue_packet,
 845 };
 846
 847 static int
 848 nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 849                   struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
 850 {
 851         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 852         u_int16_t queue_num = ntohs(nfmsg->res_id);
 853         struct nfqnl_instance *queue;
 854         int ret = 0;
 855
 856         QDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
 857
 858         if (nfattr_bad_size(nfqa, NFQA_CFG_MAX, nfqa_cfg_min)) {
 859                 QDEBUG("bad attribute size\n");
 860                 return -EINVAL;
 861         }
 862
 863         queue = instance_lookup_get(queue_num);
 864         if (nfqa[NFQA_CFG_CMD-1]) {
 865                 struct nfqnl_msg_config_cmd *cmd;
 866                 cmd = NFA_DATA(nfqa[NFQA_CFG_CMD-1]);
 867                 QDEBUG("found CFG_CMD\n");
 868
 869                 switch (cmd->command) {
 870                 case NFQNL_CFG_CMD_BIND:
 871                         if (queue)
 872                                 return -EBUSY;
 873
 874                         queue = instance_create(queue_num, NETLINK_CB(skb).pid);
 875                         if (!queue)
 876                                 return -EINVAL;
 877                         break;
 878                 case NFQNL_CFG_CMD_UNBIND:
 879                         if (!queue)
 880                                 return -ENODEV;
 881
 882                         if (queue->peer_pid != NETLINK_CB(skb).pid) {
 883                                 ret = -EPERM;
 884                                 goto out_put;
 885                         }
 886
 887                         instance_destroy(queue);
 888                         break;
 889                 case NFQNL_CFG_CMD_PF_BIND:
 890                         QDEBUG("registering queue handler for pf=%u\n",
 891                                 ntohs(cmd->pf));
 892                         ret = nf_register_queue_handler(ntohs(cmd->pf), &nfqh);
 893                         break;
 894                 case NFQNL_CFG_CMD_PF_UNBIND:
 895                         QDEBUG("unregistering queue handler for pf=%u\n",
 896                                 ntohs(cmd->pf));
 897                         /* This is a bug and a feature.  We can unregister
 898                          * other handlers(!) */
 899                         ret = nf_unregister_queue_handler(ntohs(cmd->pf));
 900                         break;
 901                 default:
 902                         ret = -EINVAL;
 903                         break;
 904                 }
 905         } else {
 906                 if (!queue) {
 907                         QDEBUG("no config command, and no instance ENOENT\n");
 908                         ret = -ENOENT;
 909                         goto out_put;
 910                 }
 911
 912                 if (queue->peer_pid != NETLINK_CB(skb).pid) {
 913                         QDEBUG("no config command, and wrong pid\n");
 914                         ret = -EPERM;
 915                         goto out_put;
 916                 }
 917         }
 918
 919         if (nfqa[NFQA_CFG_PARAMS-1]) {
 920                 struct nfqnl_msg_config_params *params;
 921                 params = NFA_DATA(nfqa[NFQA_CFG_PARAMS-1]);
 922
 923                 nfqnl_set_mode(queue, params->copy_mode,
 924                                 ntohl(params->copy_range));
 925         }
 926
 927 out_put:
 928         instance_put(queue);
 929         return ret;
 930 }
 931
 932 static struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
 933         [NFQNL_MSG_PACKET]      = { .call = nfqnl_recv_unsupp,
 934                                     .attr_count = NFQA_MAX,
 935                                     .cap_required = CAP_NET_ADMIN },
 936         [NFQNL_MSG_VERDICT]     = { .call = nfqnl_recv_verdict,
 937                                     .attr_count = NFQA_MAX,
 938                                     .cap_required = CAP_NET_ADMIN },
 939         [NFQNL_MSG_CONFIG]      = { .call = nfqnl_recv_config,
 940                                     .attr_count = NFQA_CFG_MAX,
 941                                     .cap_required = CAP_NET_ADMIN },
 942 };
 943
 944 static struct nfnetlink_subsystem nfqnl_subsys = {
 945         .name           = "nf_queue",
 946         .subsys_id      = NFNL_SUBSYS_QUEUE,
 947         .cb_count       = NFQNL_MSG_MAX,
 948         .cb             = nfqnl_cb,
 949 };
 950
 951 #ifdef CONFIG_PROC_FS
 952 struct iter_state {
 953         unsigned int bucket;
 954 };
 955
 956 static struct hlist_node *get_first(struct seq_file *seq)
 957 {
 958         struct iter_state *st = seq->private;
 959
 960         if (!st)
 961                 return NULL;
 962
 963         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
 964                 if (!hlist_empty(&instance_table[st->bucket]))
 965                         return instance_table[st->bucket].first;
 966         }
 967         return NULL;
 968 }
 969
 970 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
 971 {
 972         struct iter_state *st = seq->private;
 973
 974         h = h->next;
 975         while (!h) {
 976                 if (++st->bucket >= INSTANCE_BUCKETS)
 977                         return NULL;
 978
 979                 h = instance_table[st->bucket].first;
 980         }
 981         return h;
 982 }
 983
 984 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
 985 {
 986         struct hlist_node *head;
 987         head = get_first(seq);
 988
 989         if (head)
 990                 while (pos && (head = get_next(seq, head)))
 991                         pos--;
 992         return pos ? NULL : head;
 993 }
 994
 995 static void *seq_start(struct seq_file *seq, loff_t *pos)
 996 {
 997         read_lock_bh(&instances_lock);
 998         return get_idx(seq, *pos);
 999 }
1000
1001 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1002 {
1003         (*pos)++;
1004         return get_next(s, v);
1005 }
1006
1007 static void seq_stop(struct seq_file *s, void *v)
1008 {
1009         read_unlock_bh(&instances_lock);
1010 }
1011
1012 static int seq_show(struct seq_file *s, void *v)
1013 {
1014         const struct nfqnl_instance *inst = v;
1015
1016         return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n",
1017                           inst->queue_num,
1018                           inst->peer_pid, inst->queue_total,
1019                           inst->copy_mode, inst->copy_range,
1020                           inst->queue_dropped, inst->queue_user_dropped,
1021                           atomic_read(&inst->id_sequence),
1022                           atomic_read(&inst->use));
1023 }
1024
1025 static struct seq_operations nfqnl_seq_ops = {
1026         .start  = seq_start,
1027         .next   = seq_next,
1028         .stop   = seq_stop,
1029         .show   = seq_show,
1030 };
1031
1032 static int nfqnl_open(struct inode *inode, struct file *file)
1033 {
1034         struct seq_file *seq;
1035         struct iter_state *is;
1036         int ret;
1037
1038         is = kzalloc(sizeof(*is), GFP_KERNEL);
1039         if (!is)
1040                 return -ENOMEM;
1041         ret = seq_open(file, &nfqnl_seq_ops);
1042         if (ret < 0)
1043                 goto out_free;
1044         seq = file->private_data;
1045         seq->private = is;
1046         return ret;
1047 out_free:
1048         kfree(is);
1049         return ret;
1050 }
1051
1052 static 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
1063 init_or_cleanup(int init)
1064 {
1065         int i, status = -ENOMEM;
1066 #ifdef CONFIG_PROC_FS
1067         struct proc_dir_entry *proc_nfqueue;
1068 #endif
1069
1070         if (!init)
1071                 goto cleanup;
1072
1073         for (i = 0; i < INSTANCE_BUCKETS; i++)
1074                 INIT_HLIST_HEAD(&instance_table[i]);
1075
1076         netlink_register_notifier(&nfqnl_rtnl_notifier);
1077         status = nfnetlink_subsys_register(&nfqnl_subsys);
1078         if (status < 0) {
1079                 printk(KERN_ERR "nf_queue: failed to create netlink socket\n");
1080                 goto cleanup_netlink_notifier;
1081         }
1082
1083 #ifdef CONFIG_PROC_FS
1084         proc_nfqueue = create_proc_entry("nfnetlink_queue", 0440,
1085                                          proc_net_netfilter);
1086         if (!proc_nfqueue)
1087                 goto cleanup_subsys;
1088         proc_nfqueue->proc_fops = &nfqnl_file_ops;
1089 #endif
1090
1091         register_netdevice_notifier(&nfqnl_dev_notifier);
1092
1093         return status;
1094
1095 cleanup:
1096         nf_unregister_queue_handlers(&nfqh);
1097         unregister_netdevice_notifier(&nfqnl_dev_notifier);
1098 #ifdef CONFIG_PROC_FS
1099         remove_proc_entry("nfnetlink_queue", proc_net_netfilter);
1100 cleanup_subsys:
1101 #endif
1102         nfnetlink_subsys_unregister(&nfqnl_subsys);
1103 cleanup_netlink_notifier:
1104         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1105         return status;
1106 }
1107
1108 static int __init init(void)
1109 {
1110
1111         return init_or_cleanup(1);
1112 }
1113
1114 static void __exit fini(void)
1115 {
1116         init_or_cleanup(0);
1117 }
1118
1119 MODULE_DESCRIPTION("netfilter packet queue handler");
1120 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1121 MODULE_LICENSE("GPL");
1122 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1123
1124 module_init(init);
1125 module_exit(fini);