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 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         struct nf_info *entinf = entry->info;
 349         struct sk_buff *entskb = entry->skb;
 350         struct net_device *indev;
 351         struct net_device *outdev;
 352         unsigned int tmp_uint;
 353
 354         QDEBUG("entered\n");
 355
 356         /* all macros expand to constant values at compile time */
 357         size =    NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hdr))
 358                 + NLMSG_SPACE(sizeof(u_int32_t))        /* ifindex */
 359                 + NLMSG_SPACE(sizeof(u_int32_t))        /* ifindex */
 360 #ifdef CONFIG_BRIDGE_NETFILTER
 361                 + NLMSG_SPACE(sizeof(u_int32_t))        /* ifindex */
 362                 + NLMSG_SPACE(sizeof(u_int32_t))        /* ifindex */
 363 #endif
 364                 + NLMSG_SPACE(sizeof(u_int32_t))        /* mark */
 365                 + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hw))
 366                 + NLMSG_SPACE(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_HW &&
 380                     (*errp = skb_checksum_help(entskb,
 381                                                outdev == NULL))) {
 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 += NLMSG_SPACE(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        = htons(entskb->protocol);
 417         pmsg.hook               = entinf->hook;
 418
 419         NFA_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                 NFA_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                         NFA_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                         NFA_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                         NFA_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                                 NFA_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                 NFA_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                         NFA_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                         NFA_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                         NFA_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                                 NFA_PUT(skb, NFQA_IFINDEX_PHYSOUTDEV,
 476                                         sizeof(tmp_uint), &tmp_uint);
 477                         }
 478                 }
 479 #endif
 480         }
 481
 482         if (entskb->nfmark) {
 483                 tmp_uint = htonl(entskb->nfmark);
 484                 NFA_PUT(skb, NFQA_MARK, sizeof(u_int32_t), &tmp_uint);
 485         }
 486
 487         if (indev && entskb->dev
 488             && entskb->dev->hard_header_parse) {
 489                 struct nfqnl_msg_packet_hw phw;
 490
 491                 phw.hw_addrlen =
 492                         entskb->dev->hard_header_parse(entskb,
 493                                                            phw.hw_addr);
 494                 phw.hw_addrlen = htons(phw.hw_addrlen);
 495                 NFA_PUT(skb, NFQA_HWADDR, sizeof(phw), &phw);
 496         }
 497
 498         if (entskb->tstamp.off_sec) {
 499                 struct nfqnl_msg_packet_timestamp ts;
 500
 501                 ts.sec = cpu_to_be64(entskb->tstamp.off_sec);
 502                 ts.usec = cpu_to_be64(entskb->tstamp.off_usec);
 503
 504                 NFA_PUT(skb, NFQA_TIMESTAMP, sizeof(ts), &ts);
 505         }
 506
 507         if (data_len) {
 508                 struct nfattr *nfa;
 509                 int size = NFA_LENGTH(data_len);
 510
 511                 if (skb_tailroom(skb) < (int)NFA_SPACE(data_len)) {
 512                         printk(KERN_WARNING "nf_queue: no tailroom!\n");
 513                         goto nlmsg_failure;
 514                 }
 515
 516                 nfa = (struct nfattr *)skb_put(skb, NFA_ALIGN(size));
 517                 nfa->nfa_type = NFQA_PAYLOAD;
 518                 nfa->nfa_len = size;
 519
 520                 if (skb_copy_bits(entskb, 0, NFA_DATA(nfa), data_len))
 521                         BUG();
 522         }
 523
 524         nlh->nlmsg_len = skb->tail - old_tail;
 525         return skb;
 526
 527 nlmsg_failure:
 528 nfattr_failure:
 529         if (skb)
 530                 kfree_skb(skb);
 531         *errp = -EINVAL;
 532         if (net_ratelimit())
 533                 printk(KERN_ERR "nf_queue: error creating packet message\n");
 534         return NULL;
 535 }
 536
 537 static int
 538 nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
 539                      unsigned int queuenum, void *data)
 540 {
 541         int status = -EINVAL;
 542         struct sk_buff *nskb;
 543         struct nfqnl_instance *queue;
 544         struct nfqnl_queue_entry *entry;
 545
 546         QDEBUG("entered\n");
 547
 548         queue = instance_lookup_get(queuenum);
 549         if (!queue) {
 550                 QDEBUG("no queue instance matching\n");
 551                 return -EINVAL;
 552         }
 553
 554         if (queue->copy_mode == NFQNL_COPY_NONE) {
 555                 QDEBUG("mode COPY_NONE, aborting\n");
 556                 status = -EAGAIN;
 557                 goto err_out_put;
 558         }
 559
 560         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 561         if (entry == NULL) {
 562                 if (net_ratelimit())
 563                         printk(KERN_ERR
 564                                 "nf_queue: OOM in nfqnl_enqueue_packet()\n");
 565                 status = -ENOMEM;
 566                 goto err_out_put;
 567         }
 568
 569         entry->info = info;
 570         entry->skb = skb;
 571         entry->id = atomic_inc_return(&queue->id_sequence);
 572
 573         nskb = nfqnl_build_packet_message(queue, entry, &status);
 574         if (nskb == NULL)
 575                 goto err_out_free;
 576
 577         spin_lock_bh(&queue->lock);
 578
 579         if (!queue->peer_pid)
 580                 goto err_out_free_nskb;
 581
 582         if (queue->queue_total >= queue->queue_maxlen) {
 583                 queue->queue_dropped++;
 584                 status = -ENOSPC;
 585                 if (net_ratelimit())
 586                           printk(KERN_WARNING "ip_queue: full at %d entries, "
 587                                  "dropping packets(s). Dropped: %d\n",
 588                                  queue->queue_total, queue->queue_dropped);
 589                 goto err_out_free_nskb;
 590         }
 591
 592         /* nfnetlink_unicast will either free the nskb or add it to a socket */
 593         status = nfnetlink_unicast(nskb, queue->peer_pid, MSG_DONTWAIT);
 594         if (status < 0) {
 595                 queue->queue_user_dropped++;
 596                 goto err_out_unlock;
 597         }
 598
 599         __enqueue_entry(queue, entry);
 600
 601         spin_unlock_bh(&queue->lock);
 602         instance_put(queue);
 603         return status;
 604
 605 err_out_free_nskb:
 606         kfree_skb(nskb);
 607
 608 err_out_unlock:
 609         spin_unlock_bh(&queue->lock);
 610
 611 err_out_free:
 612         kfree(entry);
 613 err_out_put:
 614         instance_put(queue);
 615         return status;
 616 }
 617
 618 static int
 619 nfqnl_mangle(void *data, int data_len, struct nfqnl_queue_entry *e)
 620 {
 621         int diff;
 622
 623         diff = data_len - e->skb->len;
 624         if (diff < 0)
 625                 skb_trim(e->skb, data_len);
 626         else if (diff > 0) {
 627                 if (data_len > 0xFFFF)
 628                         return -EINVAL;
 629                 if (diff > skb_tailroom(e->skb)) {
 630                         struct sk_buff *newskb;
 631
 632                         newskb = skb_copy_expand(e->skb,
 633                                                  skb_headroom(e->skb),
 634                                                  diff,
 635                                                  GFP_ATOMIC);
 636                         if (newskb == NULL) {
 637                                 printk(KERN_WARNING "ip_queue: OOM "
 638                                       "in mangle, dropping packet\n");
 639                                 return -ENOMEM;
 640                         }
 641                         if (e->skb->sk)
 642                                 skb_set_owner_w(newskb, e->skb->sk);
 643                         kfree_skb(e->skb);
 644                         e->skb = newskb;
 645                 }
 646                 skb_put(e->skb, diff);
 647         }
 648         if (!skb_make_writable(&e->skb, data_len))
 649                 return -ENOMEM;
 650         memcpy(e->skb->data, data, data_len);
 651         e->skb->ip_summed = CHECKSUM_NONE;
 652         return 0;
 653 }
 654
 655 static inline int
 656 id_cmp(struct nfqnl_queue_entry *e, unsigned long id)
 657 {
 658         return (id == e->id);
 659 }
 660
 661 static int
 662 nfqnl_set_mode(struct nfqnl_instance *queue,
 663                unsigned char mode, unsigned int range)
 664 {
 665         int status;
 666
 667         spin_lock_bh(&queue->lock);
 668         status = __nfqnl_set_mode(queue, mode, range);
 669         spin_unlock_bh(&queue->lock);
 670
 671         return status;
 672 }
 673
 674 static int
 675 dev_cmp(struct nfqnl_queue_entry *entry, unsigned long ifindex)
 676 {
 677         struct nf_info *entinf = entry->info;
 678
 679         if (entinf->indev)
 680                 if (entinf->indev->ifindex == ifindex)
 681                         return 1;
 682
 683         if (entinf->outdev)
 684                 if (entinf->outdev->ifindex == ifindex)
 685                         return 1;
 686
 687         return 0;
 688 }
 689
 690 /* drop all packets with either indev or outdev == ifindex from all queue
 691  * instances */
 692 static void
 693 nfqnl_dev_drop(int ifindex)
 694 {
 695         int i;
 696
 697         QDEBUG("entering for ifindex %u\n", ifindex);
 698
 699         /* this only looks like we have to hold the readlock for a way too long
 700          * time, issue_verdict(),  nf_reinject(), ... - but we always only
 701          * issue NF_DROP, which is processed directly in nf_reinject() */
 702         read_lock_bh(&instances_lock);
 703
 704         for  (i = 0; i < INSTANCE_BUCKETS; i++) {
 705                 struct hlist_node *tmp;
 706                 struct nfqnl_instance *inst;
 707                 struct hlist_head *head = &instance_table[i];
 708
 709                 hlist_for_each_entry(inst, tmp, head, hlist) {
 710                         struct nfqnl_queue_entry *entry;
 711                         while ((entry = find_dequeue_entry(inst, dev_cmp,
 712                                                            ifindex)) != NULL)
 713                                 issue_verdict(entry, NF_DROP);
 714                 }
 715         }
 716
 717         read_unlock_bh(&instances_lock);
 718 }
 719
 720 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 721
 722 static int
 723 nfqnl_rcv_dev_event(struct notifier_block *this,
 724                     unsigned long event, void *ptr)
 725 {
 726         struct net_device *dev = ptr;
 727
 728         /* Drop any packets associated with the downed device */
 729         if (event == NETDEV_DOWN)
 730                 nfqnl_dev_drop(dev->ifindex);
 731         return NOTIFY_DONE;
 732 }
 733
 734 static struct notifier_block nfqnl_dev_notifier = {
 735         .notifier_call  = nfqnl_rcv_dev_event,
 736 };
 737
 738 static int
 739 nfqnl_rcv_nl_event(struct notifier_block *this,
 740                    unsigned long event, void *ptr)
 741 {
 742         struct netlink_notify *n = ptr;
 743
 744         if (event == NETLINK_URELEASE &&
 745             n->protocol == NETLINK_NETFILTER && n->pid) {
 746                 int i;
 747
 748                 /* destroy all instances for this pid */
 749                 write_lock_bh(&instances_lock);
 750                 for  (i = 0; i < INSTANCE_BUCKETS; i++) {
 751                         struct hlist_node *tmp, *t2;
 752                         struct nfqnl_instance *inst;
 753                         struct hlist_head *head = &instance_table[i];
 754
 755                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
 756                                 if (n->pid == inst->peer_pid)
 757                                         __instance_destroy(inst);
 758                         }
 759                 }
 760                 write_unlock_bh(&instances_lock);
 761         }
 762         return NOTIFY_DONE;
 763 }
 764
 765 static struct notifier_block nfqnl_rtnl_notifier = {
 766         .notifier_call  = nfqnl_rcv_nl_event,
 767 };
 768
 769 static const int nfqa_verdict_min[NFQA_MAX] = {
 770         [NFQA_VERDICT_HDR-1]    = sizeof(struct nfqnl_msg_verdict_hdr),
 771         [NFQA_MARK-1]           = sizeof(u_int32_t),
 772         [NFQA_PAYLOAD-1]        = 0,
 773 };
 774
 775 static int
 776 nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
 777                    struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
 778 {
 779         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 780         u_int16_t queue_num = ntohs(nfmsg->res_id);
 781
 782         struct nfqnl_msg_verdict_hdr *vhdr;
 783         struct nfqnl_instance *queue;
 784         unsigned int verdict;
 785         struct nfqnl_queue_entry *entry;
 786         int err;
 787
 788         if (nfattr_bad_size(nfqa, NFQA_MAX, nfqa_verdict_min)) {
 789                 QDEBUG("bad attribute size\n");
 790                 return -EINVAL;
 791         }
 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-1]) {
 803                 err = -EINVAL;
 804                 goto err_out_put;
 805         }
 806
 807         vhdr = NFA_DATA(nfqa[NFQA_VERDICT_HDR-1]);
 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-1]) {
 822                 if (nfqnl_mangle(NFA_DATA(nfqa[NFQA_PAYLOAD-1]),
 823                                  NFA_PAYLOAD(nfqa[NFQA_PAYLOAD-1]), entry) < 0)
 824                         verdict = NF_DROP;
 825         }
 826
 827         if (nfqa[NFQA_MARK-1])
 828                 entry->skb->nfmark = ntohl(*(u_int32_t *)
 829                                            NFA_DATA(nfqa[NFQA_MARK-1]));
 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 nfattr *nfqa[], int *errp)
 843 {
 844         return -ENOTSUPP;
 845 }
 846
 847 static const int nfqa_cfg_min[NFQA_CFG_MAX] = {
 848         [NFQA_CFG_CMD-1]        = sizeof(struct nfqnl_msg_config_cmd),
 849         [NFQA_CFG_PARAMS-1]     = 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 nfattr *nfqa[], int *errp)
 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         if (nfattr_bad_size(nfqa, NFQA_CFG_MAX, nfqa_cfg_min)) {
 869                 QDEBUG("bad attribute size\n");
 870                 return -EINVAL;
 871         }
 872
 873         queue = instance_lookup_get(queue_num);
 874         if (nfqa[NFQA_CFG_CMD-1]) {
 875                 struct nfqnl_msg_config_cmd *cmd;
 876                 cmd = NFA_DATA(nfqa[NFQA_CFG_CMD-1]);
 877                 QDEBUG("found CFG_CMD\n");
 878
 879                 switch (cmd->command) {
 880                 case NFQNL_CFG_CMD_BIND:
 881                         if (queue)
 882                                 return -EBUSY;
 883
 884                         queue = instance_create(queue_num, NETLINK_CB(skb).pid);
 885                         if (!queue)
 886                                 return -EINVAL;
 887                         break;
 888                 case NFQNL_CFG_CMD_UNBIND:
 889                         if (!queue)
 890                                 return -ENODEV;
 891
 892                         if (queue->peer_pid != NETLINK_CB(skb).pid) {
 893                                 ret = -EPERM;
 894                                 goto out_put;
 895                         }
 896
 897                         instance_destroy(queue);
 898                         break;
 899                 case NFQNL_CFG_CMD_PF_BIND:
 900                         QDEBUG("registering queue handler for pf=%u\n",
 901                                 ntohs(cmd->pf));
 902                         ret = nf_register_queue_handler(ntohs(cmd->pf), &nfqh);
 903                         break;
 904                 case NFQNL_CFG_CMD_PF_UNBIND:
 905                         QDEBUG("unregistering queue handler for pf=%u\n",
 906                                 ntohs(cmd->pf));
 907                         /* This is a bug and a feature.  We can unregister
 908                          * other handlers(!) */
 909                         ret = nf_unregister_queue_handler(ntohs(cmd->pf));
 910                         break;
 911                 default:
 912                         ret = -EINVAL;
 913                         break;
 914                 }
 915         } else {
 916                 if (!queue) {
 917                         QDEBUG("no config command, and no instance ENOENT\n");
 918                         ret = -ENOENT;
 919                         goto out_put;
 920                 }
 921
 922                 if (queue->peer_pid != NETLINK_CB(skb).pid) {
 923                         QDEBUG("no config command, and wrong pid\n");
 924                         ret = -EPERM;
 925                         goto out_put;
 926                 }
 927         }
 928
 929         if (nfqa[NFQA_CFG_PARAMS-1]) {
 930                 struct nfqnl_msg_config_params *params;
 931                 params = NFA_DATA(nfqa[NFQA_CFG_PARAMS-1]);
 932
 933                 nfqnl_set_mode(queue, params->copy_mode,
 934                                 ntohl(params->copy_range));
 935         }
 936
 937 out_put:
 938         instance_put(queue);
 939         return ret;
 940 }
 941
 942 static struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
 943         [NFQNL_MSG_PACKET]      = { .call = nfqnl_recv_unsupp,
 944                                     .attr_count = NFQA_MAX, },
 945         [NFQNL_MSG_VERDICT]     = { .call = nfqnl_recv_verdict,
 946                                     .attr_count = NFQA_MAX, },
 947         [NFQNL_MSG_CONFIG]      = { .call = nfqnl_recv_config,
 948                                     .attr_count = NFQA_CFG_MAX, },
 949 };
 950
 951 static 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
 959 struct iter_state {
 960         unsigned int bucket;
 961 };
 962
 963 static 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
 977 static 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
 991 static 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
1002 static void *seq_start(struct seq_file *seq, loff_t *pos)
1003 {
1004         read_lock_bh(&instances_lock);
1005         return get_idx(seq, *pos);
1006 }
1007
1008 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1009 {
1010         (*pos)++;
1011         return get_next(s, v);
1012 }
1013
1014 static void seq_stop(struct seq_file *s, void *v)
1015 {
1016         read_unlock_bh(&instances_lock);
1017 }
1018
1019 static int seq_show(struct seq_file *s, void *v)
1020 {
1021         const struct nfqnl_instance *inst = v;
1022
1023         return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n",
1024                           inst->queue_num,
1025                           inst->peer_pid, inst->queue_total,
1026                           inst->copy_mode, inst->copy_range,
1027                           inst->queue_dropped, inst->queue_user_dropped,
1028                           atomic_read(&inst->id_sequence),
1029                           atomic_read(&inst->use));
1030 }
1031
1032 static struct seq_operations nfqnl_seq_ops = {
1033         .start  = seq_start,
1034         .next   = seq_next,
1035         .stop   = seq_stop,
1036         .show   = seq_show,
1037 };
1038
1039 static int nfqnl_open(struct inode *inode, struct file *file)
1040 {
1041         struct seq_file *seq;
1042         struct iter_state *is;
1043         int ret;
1044
1045         is = kzalloc(sizeof(*is), GFP_KERNEL);
1046         if (!is)
1047                 return -ENOMEM;
1048         ret = seq_open(file, &nfqnl_seq_ops);
1049         if (ret < 0)
1050                 goto out_free;
1051         seq = file->private_data;
1052         seq->private = is;
1053         return ret;
1054 out_free:
1055         kfree(is);
1056         return ret;
1057 }
1058
1059 static struct file_operations nfqnl_file_ops = {
1060         .owner   = THIS_MODULE,
1061         .open    = nfqnl_open,
1062         .read    = seq_read,
1063         .llseek  = seq_lseek,
1064         .release = seq_release_private,
1065 };
1066
1067 #endif /* PROC_FS */
1068
1069 static int
1070 init_or_cleanup(int init)
1071 {
1072         int i, status = -ENOMEM;
1073 #ifdef CONFIG_PROC_FS
1074         struct proc_dir_entry *proc_nfqueue;
1075 #endif
1076
1077         if (!init)
1078                 goto cleanup;
1079
1080         for (i = 0; i < INSTANCE_BUCKETS; i++)
1081                 INIT_HLIST_HEAD(&instance_table[i]);
1082
1083         netlink_register_notifier(&nfqnl_rtnl_notifier);
1084         status = nfnetlink_subsys_register(&nfqnl_subsys);
1085         if (status < 0) {
1086                 printk(KERN_ERR "nf_queue: failed to create netlink socket\n");
1087                 goto cleanup_netlink_notifier;
1088         }
1089
1090 #ifdef CONFIG_PROC_FS
1091         proc_nfqueue = create_proc_entry("nfnetlink_queue", 0440,
1092                                          proc_net_netfilter);
1093         if (!proc_nfqueue)
1094                 goto cleanup_subsys;
1095         proc_nfqueue->proc_fops = &nfqnl_file_ops;
1096 #endif
1097
1098         register_netdevice_notifier(&nfqnl_dev_notifier);
1099
1100         return status;
1101
1102 cleanup:
1103         nf_unregister_queue_handlers(&nfqh);
1104         unregister_netdevice_notifier(&nfqnl_dev_notifier);
1105 #ifdef CONFIG_PROC_FS
1106         remove_proc_entry("nfnetlink_queue", proc_net_netfilter);
1107 cleanup_subsys:
1108 #endif
1109         nfnetlink_subsys_unregister(&nfqnl_subsys);
1110 cleanup_netlink_notifier:
1111         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1112         return status;
1113 }
1114
1115 static int __init init(void)
1116 {
1117
1118         return init_or_cleanup(1);
1119 }
1120
1121 static void __exit fini(void)
1122 {
1123         init_or_cleanup(0);
1124 }
1125
1126 MODULE_DESCRIPTION("netfilter packet queue handler");
1127 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1128 MODULE_LICENSE("GPL");
1129 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1130
1131 module_init(init);
1132 module_exit(fini);