1 /* 2 * This is a module which is used for queueing packets and communicating with 3 * userspace via nfnetlink. 4 * 5 * (C) 2005 by Harald Welte <[email protected]> 6 * (C) 2007 by Patrick McHardy <[email protected]> 7 * 8 * Based on the old ipv4-only ip_queue.c: 9 * (C) 2000-2002 James Morris <[email protected]> 10 * (C) 2003-2005 Netfilter Core Team <[email protected]> 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License version 2 as 14 * published by the Free Software Foundation. 15 * 16 */ 17 #include <linux/module.h> 18 #include <linux/skbuff.h> 19 #include <linux/init.h> 20 #include <linux/spinlock.h> 21 #include <linux/slab.h> 22 #include <linux/notifier.h> 23 #include <linux/netdevice.h> 24 #include <linux/netfilter.h> 25 #include <linux/proc_fs.h> 26 #include <linux/netfilter_ipv4.h> 27 #include <linux/netfilter_ipv6.h> 28 #include <linux/netfilter/nfnetlink.h> 29 #include <linux/netfilter/nfnetlink_queue.h> 30 #include <linux/list.h> 31 #include <net/sock.h> 32 #include <net/netfilter/nf_queue.h> 33 34 #include <asm/atomic.h> 35 36 #ifdef CONFIG_BRIDGE_NETFILTER 37 #include "../bridge/br_private.h" 38 #endif 39 40 #define NFQNL_QMAX_DEFAULT 1024 41 42 struct nfqnl_instance { 43 struct hlist_node hlist; /* global list of queues */ 44 struct rcu_head rcu; 45 46 int peer_pid; 47 unsigned int queue_maxlen; 48 unsigned int copy_range; 49 unsigned int queue_dropped; 50 unsigned int queue_user_dropped; 51 52 53 u_int16_t queue_num; /* number of this queue */ 54 u_int8_t copy_mode; 55 /* 56 * Following fields are dirtied for each queued packet, 57 * keep them in same cache line if possible. 58 */ 59 spinlock_t lock; 60 unsigned int queue_total; 61 atomic_t id_sequence; /* 'sequence' of pkt ids */ 62 struct list_head queue_list; /* packets in queue */ 63 }; 64 65 typedef int (*nfqnl_cmpfn)(struct nf_queue_entry *, unsigned long); 66 67 static DEFINE_SPINLOCK(instances_lock); 68 69 #define INSTANCE_BUCKETS 16 70 static struct hlist_head instance_table[INSTANCE_BUCKETS] __read_mostly; 71 72 static inline u_int8_t instance_hashfn(u_int16_t queue_num) 73 { 74 return ((queue_num >> 8) | queue_num) % INSTANCE_BUCKETS; 75 } 76 77 static struct nfqnl_instance * 78 instance_lookup(u_int16_t queue_num) 79 { 80 struct hlist_head *head; 81 struct hlist_node *pos; 82 struct nfqnl_instance *inst; 83 84 head = &instance_table[instance_hashfn(queue_num)]; 85 hlist_for_each_entry_rcu(inst, pos, head, hlist) { 86 if (inst->queue_num == queue_num) 87 return inst; 88 } 89 return NULL; 90 } 91 92 static struct nfqnl_instance * 93 instance_create(u_int16_t queue_num, int pid) 94 { 95 struct nfqnl_instance *inst; 96 unsigned int h; 97 int err; 98 99 spin_lock(&instances_lock); 100 if (instance_lookup(queue_num)) { 101 err = -EEXIST; 102 goto out_unlock; 103 } 104 105 inst = kzalloc(sizeof(*inst), GFP_ATOMIC); 106 if (!inst) { 107 err = -ENOMEM; 108 goto out_unlock; 109 } 110 111 inst->queue_num = queue_num; 112 inst->peer_pid = pid; 113 inst->queue_maxlen = NFQNL_QMAX_DEFAULT; 114 inst->copy_range = 0xfffff; 115 inst->copy_mode = NFQNL_COPY_NONE; 116 spin_lock_init(&inst->lock); 117 INIT_LIST_HEAD(&inst->queue_list); 118 119 if (!try_module_get(THIS_MODULE)) { 120 err = -EAGAIN; 121 goto out_free; 122 } 123 124 h = instance_hashfn(queue_num); 125 hlist_add_head_rcu(&inst->hlist, &instance_table[h]); 126 127 spin_unlock(&instances_lock); 128 129 return inst; 130 131 out_free: 132 kfree(inst); 133 out_unlock: 134 spin_unlock(&instances_lock); 135 return ERR_PTR(err); 136 } 137 138 static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, 139 unsigned long data); 140 141 static void 142 instance_destroy_rcu(struct rcu_head *head) 143 { 144 struct nfqnl_instance *inst = container_of(head, struct nfqnl_instance, 145 rcu); 146 147 nfqnl_flush(inst, NULL, 0); 148 kfree(inst); 149 module_put(THIS_MODULE); 150 } 151 152 static void 153 __instance_destroy(struct nfqnl_instance *inst) 154 { 155 hlist_del_rcu(&inst->hlist); 156 call_rcu(&inst->rcu, instance_destroy_rcu); 157 } 158 159 static void 160 instance_destroy(struct nfqnl_instance *inst) 161 { 162 spin_lock(&instances_lock); 163 __instance_destroy(inst); 164 spin_unlock(&instances_lock); 165 } 166 167 static inline void 168 __enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry) 169 { 170 list_add_tail(&entry->list, &queue->queue_list); 171 queue->queue_total++; 172 } 173 174 static struct nf_queue_entry * 175 find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id) 176 { 177 struct nf_queue_entry *entry = NULL, *i; 178 179 spin_lock_bh(&queue->lock); 180 181 list_for_each_entry(i, &queue->queue_list, list) { 182 if (i->id == id) { 183 entry = i; 184 break; 185 } 186 } 187 188 if (entry) { 189 list_del(&entry->list); 190 queue->queue_total--; 191 } 192 193 spin_unlock_bh(&queue->lock); 194 195 return entry; 196 } 197 198 static void 199 nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data) 200 { 201 struct nf_queue_entry *entry, *next; 202 203 spin_lock_bh(&queue->lock); 204 list_for_each_entry_safe(entry, next, &queue->queue_list, list) { 205 if (!cmpfn || cmpfn(entry, data)) { 206 list_del(&entry->list); 207 queue->queue_total--; 208 nf_reinject(entry, NF_DROP); 209 } 210 } 211 spin_unlock_bh(&queue->lock); 212 } 213 214 static struct sk_buff * 215 nfqnl_build_packet_message(struct nfqnl_instance *queue, 216 struct nf_queue_entry *entry) 217 { 218 sk_buff_data_t old_tail; 219 size_t size; 220 size_t data_len = 0; 221 struct sk_buff *skb; 222 struct nfqnl_msg_packet_hdr pmsg; 223 struct nlmsghdr *nlh; 224 struct nfgenmsg *nfmsg; 225 struct sk_buff *entskb = entry->skb; 226 struct net_device *indev; 227 struct net_device *outdev; 228 229 size = NLMSG_SPACE(sizeof(struct nfgenmsg)) 230 + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr)) 231 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 232 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 233 #ifdef CONFIG_BRIDGE_NETFILTER 234 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 235 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 236 #endif 237 + nla_total_size(sizeof(u_int32_t)) /* mark */ 238 + nla_total_size(sizeof(struct nfqnl_msg_packet_hw)) 239 + nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp)); 240 241 outdev = entry->outdev; 242 243 switch ((enum nfqnl_config_mode)ACCESS_ONCE(queue->copy_mode)) { 244 case NFQNL_COPY_META: 245 case NFQNL_COPY_NONE: 246 break; 247 248 case NFQNL_COPY_PACKET: 249 if (entskb->ip_summed == CHECKSUM_PARTIAL && 250 skb_checksum_help(entskb)) 251 return NULL; 252 253 data_len = ACCESS_ONCE(queue->copy_range); 254 if (data_len == 0 || data_len > entskb->len) 255 data_len = entskb->len; 256 257 size += nla_total_size(data_len); 258 break; 259 } 260 261 262 skb = alloc_skb(size, GFP_ATOMIC); 263 if (!skb) 264 goto nlmsg_failure; 265 266 old_tail = skb->tail; 267 nlh = NLMSG_PUT(skb, 0, 0, 268 NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET, 269 sizeof(struct nfgenmsg)); 270 nfmsg = NLMSG_DATA(nlh); 271 nfmsg->nfgen_family = entry->pf; 272 nfmsg->version = NFNETLINK_V0; 273 nfmsg->res_id = htons(queue->queue_num); 274 275 entry->id = atomic_inc_return(&queue->id_sequence); 276 pmsg.packet_id = htonl(entry->id); 277 pmsg.hw_protocol = entskb->protocol; 278 pmsg.hook = entry->hook; 279 280 NLA_PUT(skb, NFQA_PACKET_HDR, sizeof(pmsg), &pmsg); 281 282 indev = entry->indev; 283 if (indev) { 284 #ifndef CONFIG_BRIDGE_NETFILTER 285 NLA_PUT_BE32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex)); 286 #else 287 if (entry->pf == PF_BRIDGE) { 288 /* Case 1: indev is physical input device, we need to 289 * look for bridge group (when called from 290 * netfilter_bridge) */ 291 NLA_PUT_BE32(skb, NFQA_IFINDEX_PHYSINDEV, 292 htonl(indev->ifindex)); 293 /* this is the bridge group "brX" */ 294 /* rcu_read_lock()ed by __nf_queue */ 295 NLA_PUT_BE32(skb, NFQA_IFINDEX_INDEV, 296 htonl(br_port_get_rcu(indev)->br->dev->ifindex)); 297 } else { 298 /* Case 2: indev is bridge group, we need to look for 299 * physical device (when called from ipv4) */ 300 NLA_PUT_BE32(skb, NFQA_IFINDEX_INDEV, 301 htonl(indev->ifindex)); 302 if (entskb->nf_bridge && entskb->nf_bridge->physindev) 303 NLA_PUT_BE32(skb, NFQA_IFINDEX_PHYSINDEV, 304 htonl(entskb->nf_bridge->physindev->ifindex)); 305 } 306 #endif 307 } 308 309 if (outdev) { 310 #ifndef CONFIG_BRIDGE_NETFILTER 311 NLA_PUT_BE32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex)); 312 #else 313 if (entry->pf == PF_BRIDGE) { 314 /* Case 1: outdev is physical output device, we need to 315 * look for bridge group (when called from 316 * netfilter_bridge) */ 317 NLA_PUT_BE32(skb, NFQA_IFINDEX_PHYSOUTDEV, 318 htonl(outdev->ifindex)); 319 /* this is the bridge group "brX" */ 320 /* rcu_read_lock()ed by __nf_queue */ 321 NLA_PUT_BE32(skb, NFQA_IFINDEX_OUTDEV, 322 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)); 323 } else { 324 /* Case 2: outdev is bridge group, we need to look for 325 * physical output device (when called from ipv4) */ 326 NLA_PUT_BE32(skb, NFQA_IFINDEX_OUTDEV, 327 htonl(outdev->ifindex)); 328 if (entskb->nf_bridge && entskb->nf_bridge->physoutdev) 329 NLA_PUT_BE32(skb, NFQA_IFINDEX_PHYSOUTDEV, 330 htonl(entskb->nf_bridge->physoutdev->ifindex)); 331 } 332 #endif 333 } 334 335 if (entskb->mark) 336 NLA_PUT_BE32(skb, NFQA_MARK, htonl(entskb->mark)); 337 338 if (indev && entskb->dev) { 339 struct nfqnl_msg_packet_hw phw; 340 int len = dev_parse_header(entskb, phw.hw_addr); 341 if (len) { 342 phw.hw_addrlen = htons(len); 343 NLA_PUT(skb, NFQA_HWADDR, sizeof(phw), &phw); 344 } 345 } 346 347 if (entskb->tstamp.tv64) { 348 struct nfqnl_msg_packet_timestamp ts; 349 struct timeval tv = ktime_to_timeval(entskb->tstamp); 350 ts.sec = cpu_to_be64(tv.tv_sec); 351 ts.usec = cpu_to_be64(tv.tv_usec); 352 353 NLA_PUT(skb, NFQA_TIMESTAMP, sizeof(ts), &ts); 354 } 355 356 if (data_len) { 357 struct nlattr *nla; 358 int sz = nla_attr_size(data_len); 359 360 if (skb_tailroom(skb) < nla_total_size(data_len)) { 361 printk(KERN_WARNING "nf_queue: no tailroom!\n"); 362 goto nlmsg_failure; 363 } 364 365 nla = (struct nlattr *)skb_put(skb, nla_total_size(data_len)); 366 nla->nla_type = NFQA_PAYLOAD; 367 nla->nla_len = sz; 368 369 if (skb_copy_bits(entskb, 0, nla_data(nla), data_len)) 370 BUG(); 371 } 372 373 nlh->nlmsg_len = skb->tail - old_tail; 374 return skb; 375 376 nlmsg_failure: 377 nla_put_failure: 378 if (skb) 379 kfree_skb(skb); 380 if (net_ratelimit()) 381 printk(KERN_ERR "nf_queue: error creating packet message\n"); 382 return NULL; 383 } 384 385 static int 386 nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum) 387 { 388 struct sk_buff *nskb; 389 struct nfqnl_instance *queue; 390 int err; 391 392 /* rcu_read_lock()ed by nf_hook_slow() */ 393 queue = instance_lookup(queuenum); 394 if (!queue) 395 goto err_out; 396 397 if (queue->copy_mode == NFQNL_COPY_NONE) 398 goto err_out; 399 400 nskb = nfqnl_build_packet_message(queue, entry); 401 if (nskb == NULL) 402 goto err_out; 403 404 spin_lock_bh(&queue->lock); 405 406 if (!queue->peer_pid) 407 goto err_out_free_nskb; 408 409 if (queue->queue_total >= queue->queue_maxlen) { 410 queue->queue_dropped++; 411 if (net_ratelimit()) 412 printk(KERN_WARNING "nf_queue: full at %d entries, " 413 "dropping packets(s).\n", 414 queue->queue_total); 415 goto err_out_free_nskb; 416 } 417 418 /* nfnetlink_unicast will either free the nskb or add it to a socket */ 419 err = nfnetlink_unicast(nskb, &init_net, queue->peer_pid, MSG_DONTWAIT); 420 if (err < 0) { 421 queue->queue_user_dropped++; 422 goto err_out_unlock; 423 } 424 425 __enqueue_entry(queue, entry); 426 427 spin_unlock_bh(&queue->lock); 428 return 0; 429 430 err_out_free_nskb: 431 kfree_skb(nskb); 432 err_out_unlock: 433 spin_unlock_bh(&queue->lock); 434 err_out: 435 return -1; 436 } 437 438 static int 439 nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e) 440 { 441 struct sk_buff *nskb; 442 int diff; 443 444 diff = data_len - e->skb->len; 445 if (diff < 0) { 446 if (pskb_trim(e->skb, data_len)) 447 return -ENOMEM; 448 } else if (diff > 0) { 449 if (data_len > 0xFFFF) 450 return -EINVAL; 451 if (diff > skb_tailroom(e->skb)) { 452 nskb = skb_copy_expand(e->skb, skb_headroom(e->skb), 453 diff, GFP_ATOMIC); 454 if (!nskb) { 455 printk(KERN_WARNING "nf_queue: OOM " 456 "in mangle, dropping packet\n"); 457 return -ENOMEM; 458 } 459 kfree_skb(e->skb); 460 e->skb = nskb; 461 } 462 skb_put(e->skb, diff); 463 } 464 if (!skb_make_writable(e->skb, data_len)) 465 return -ENOMEM; 466 skb_copy_to_linear_data(e->skb, data, data_len); 467 e->skb->ip_summed = CHECKSUM_NONE; 468 return 0; 469 } 470 471 static int 472 nfqnl_set_mode(struct nfqnl_instance *queue, 473 unsigned char mode, unsigned int range) 474 { 475 int status = 0; 476 477 spin_lock_bh(&queue->lock); 478 switch (mode) { 479 case NFQNL_COPY_NONE: 480 case NFQNL_COPY_META: 481 queue->copy_mode = mode; 482 queue->copy_range = 0; 483 break; 484 485 case NFQNL_COPY_PACKET: 486 queue->copy_mode = mode; 487 /* we're using struct nlattr which has 16bit nla_len */ 488 if (range > 0xffff) 489 queue->copy_range = 0xffff; 490 else 491 queue->copy_range = range; 492 break; 493 494 default: 495 status = -EINVAL; 496 497 } 498 spin_unlock_bh(&queue->lock); 499 500 return status; 501 } 502 503 static int 504 dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex) 505 { 506 if (entry->indev) 507 if (entry->indev->ifindex == ifindex) 508 return 1; 509 if (entry->outdev) 510 if (entry->outdev->ifindex == ifindex) 511 return 1; 512 #ifdef CONFIG_BRIDGE_NETFILTER 513 if (entry->skb->nf_bridge) { 514 if (entry->skb->nf_bridge->physindev && 515 entry->skb->nf_bridge->physindev->ifindex == ifindex) 516 return 1; 517 if (entry->skb->nf_bridge->physoutdev && 518 entry->skb->nf_bridge->physoutdev->ifindex == ifindex) 519 return 1; 520 } 521 #endif 522 return 0; 523 } 524 525 /* drop all packets with either indev or outdev == ifindex from all queue 526 * instances */ 527 static void 528 nfqnl_dev_drop(int ifindex) 529 { 530 int i; 531 532 rcu_read_lock(); 533 534 for (i = 0; i < INSTANCE_BUCKETS; i++) { 535 struct hlist_node *tmp; 536 struct nfqnl_instance *inst; 537 struct hlist_head *head = &instance_table[i]; 538 539 hlist_for_each_entry_rcu(inst, tmp, head, hlist) 540 nfqnl_flush(inst, dev_cmp, ifindex); 541 } 542 543 rcu_read_unlock(); 544 } 545 546 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0) 547 548 static int 549 nfqnl_rcv_dev_event(struct notifier_block *this, 550 unsigned long event, void *ptr) 551 { 552 struct net_device *dev = ptr; 553 554 if (!net_eq(dev_net(dev), &init_net)) 555 return NOTIFY_DONE; 556 557 /* Drop any packets associated with the downed device */ 558 if (event == NETDEV_DOWN) 559 nfqnl_dev_drop(dev->ifindex); 560 return NOTIFY_DONE; 561 } 562 563 static struct notifier_block nfqnl_dev_notifier = { 564 .notifier_call = nfqnl_rcv_dev_event, 565 }; 566 567 static int 568 nfqnl_rcv_nl_event(struct notifier_block *this, 569 unsigned long event, void *ptr) 570 { 571 struct netlink_notify *n = ptr; 572 573 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) { 574 int i; 575 576 /* destroy all instances for this pid */ 577 spin_lock(&instances_lock); 578 for (i = 0; i < INSTANCE_BUCKETS; i++) { 579 struct hlist_node *tmp, *t2; 580 struct nfqnl_instance *inst; 581 struct hlist_head *head = &instance_table[i]; 582 583 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) { 584 if ((n->net == &init_net) && 585 (n->pid == inst->peer_pid)) 586 __instance_destroy(inst); 587 } 588 } 589 spin_unlock(&instances_lock); 590 } 591 return NOTIFY_DONE; 592 } 593 594 static struct notifier_block nfqnl_rtnl_notifier = { 595 .notifier_call = nfqnl_rcv_nl_event, 596 }; 597 598 static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = { 599 [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) }, 600 [NFQA_MARK] = { .type = NLA_U32 }, 601 [NFQA_PAYLOAD] = { .type = NLA_UNSPEC }, 602 }; 603 604 static int 605 nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb, 606 const struct nlmsghdr *nlh, 607 const struct nlattr * const nfqa[]) 608 { 609 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); 610 u_int16_t queue_num = ntohs(nfmsg->res_id); 611 612 struct nfqnl_msg_verdict_hdr *vhdr; 613 struct nfqnl_instance *queue; 614 unsigned int verdict; 615 struct nf_queue_entry *entry; 616 int err; 617 618 rcu_read_lock(); 619 queue = instance_lookup(queue_num); 620 if (!queue) { 621 err = -ENODEV; 622 goto err_out_unlock; 623 } 624 625 if (queue->peer_pid != NETLINK_CB(skb).pid) { 626 err = -EPERM; 627 goto err_out_unlock; 628 } 629 630 if (!nfqa[NFQA_VERDICT_HDR]) { 631 err = -EINVAL; 632 goto err_out_unlock; 633 } 634 635 vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]); 636 verdict = ntohl(vhdr->verdict); 637 638 if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) { 639 err = -EINVAL; 640 goto err_out_unlock; 641 } 642 643 entry = find_dequeue_entry(queue, ntohl(vhdr->id)); 644 if (entry == NULL) { 645 err = -ENOENT; 646 goto err_out_unlock; 647 } 648 rcu_read_unlock(); 649 650 if (nfqa[NFQA_PAYLOAD]) { 651 if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]), 652 nla_len(nfqa[NFQA_PAYLOAD]), entry) < 0) 653 verdict = NF_DROP; 654 } 655 656 if (nfqa[NFQA_MARK]) 657 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK])); 658 659 nf_reinject(entry, verdict); 660 return 0; 661 662 err_out_unlock: 663 rcu_read_unlock(); 664 return err; 665 } 666 667 static int 668 nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb, 669 const struct nlmsghdr *nlh, 670 const struct nlattr * const nfqa[]) 671 { 672 return -ENOTSUPP; 673 } 674 675 static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = { 676 [NFQA_CFG_CMD] = { .len = sizeof(struct nfqnl_msg_config_cmd) }, 677 [NFQA_CFG_PARAMS] = { .len = sizeof(struct nfqnl_msg_config_params) }, 678 }; 679 680 static const struct nf_queue_handler nfqh = { 681 .name = "nf_queue", 682 .outfn = &nfqnl_enqueue_packet, 683 }; 684 685 static int 686 nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb, 687 const struct nlmsghdr *nlh, 688 const struct nlattr * const nfqa[]) 689 { 690 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); 691 u_int16_t queue_num = ntohs(nfmsg->res_id); 692 struct nfqnl_instance *queue; 693 struct nfqnl_msg_config_cmd *cmd = NULL; 694 int ret = 0; 695 696 if (nfqa[NFQA_CFG_CMD]) { 697 cmd = nla_data(nfqa[NFQA_CFG_CMD]); 698 699 /* Commands without queue context - might sleep */ 700 switch (cmd->command) { 701 case NFQNL_CFG_CMD_PF_BIND: 702 return nf_register_queue_handler(ntohs(cmd->pf), 703 &nfqh); 704 case NFQNL_CFG_CMD_PF_UNBIND: 705 return nf_unregister_queue_handler(ntohs(cmd->pf), 706 &nfqh); 707 } 708 } 709 710 rcu_read_lock(); 711 queue = instance_lookup(queue_num); 712 if (queue && queue->peer_pid != NETLINK_CB(skb).pid) { 713 ret = -EPERM; 714 goto err_out_unlock; 715 } 716 717 if (cmd != NULL) { 718 switch (cmd->command) { 719 case NFQNL_CFG_CMD_BIND: 720 if (queue) { 721 ret = -EBUSY; 722 goto err_out_unlock; 723 } 724 queue = instance_create(queue_num, NETLINK_CB(skb).pid); 725 if (IS_ERR(queue)) { 726 ret = PTR_ERR(queue); 727 goto err_out_unlock; 728 } 729 break; 730 case NFQNL_CFG_CMD_UNBIND: 731 if (!queue) { 732 ret = -ENODEV; 733 goto err_out_unlock; 734 } 735 instance_destroy(queue); 736 break; 737 case NFQNL_CFG_CMD_PF_BIND: 738 case NFQNL_CFG_CMD_PF_UNBIND: 739 break; 740 default: 741 ret = -ENOTSUPP; 742 break; 743 } 744 } 745 746 if (nfqa[NFQA_CFG_PARAMS]) { 747 struct nfqnl_msg_config_params *params; 748 749 if (!queue) { 750 ret = -ENODEV; 751 goto err_out_unlock; 752 } 753 params = nla_data(nfqa[NFQA_CFG_PARAMS]); 754 nfqnl_set_mode(queue, params->copy_mode, 755 ntohl(params->copy_range)); 756 } 757 758 if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) { 759 __be32 *queue_maxlen; 760 761 if (!queue) { 762 ret = -ENODEV; 763 goto err_out_unlock; 764 } 765 queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]); 766 spin_lock_bh(&queue->lock); 767 queue->queue_maxlen = ntohl(*queue_maxlen); 768 spin_unlock_bh(&queue->lock); 769 } 770 771 err_out_unlock: 772 rcu_read_unlock(); 773 return ret; 774 } 775 776 static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = { 777 [NFQNL_MSG_PACKET] = { .call = nfqnl_recv_unsupp, 778 .attr_count = NFQA_MAX, }, 779 [NFQNL_MSG_VERDICT] = { .call = nfqnl_recv_verdict, 780 .attr_count = NFQA_MAX, 781 .policy = nfqa_verdict_policy }, 782 [NFQNL_MSG_CONFIG] = { .call = nfqnl_recv_config, 783 .attr_count = NFQA_CFG_MAX, 784 .policy = nfqa_cfg_policy }, 785 }; 786 787 static const struct nfnetlink_subsystem nfqnl_subsys = { 788 .name = "nf_queue", 789 .subsys_id = NFNL_SUBSYS_QUEUE, 790 .cb_count = NFQNL_MSG_MAX, 791 .cb = nfqnl_cb, 792 }; 793 794 #ifdef CONFIG_PROC_FS 795 struct iter_state { 796 unsigned int bucket; 797 }; 798 799 static struct hlist_node *get_first(struct seq_file *seq) 800 { 801 struct iter_state *st = seq->private; 802 803 if (!st) 804 return NULL; 805 806 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) { 807 if (!hlist_empty(&instance_table[st->bucket])) 808 return instance_table[st->bucket].first; 809 } 810 return NULL; 811 } 812 813 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h) 814 { 815 struct iter_state *st = seq->private; 816 817 h = h->next; 818 while (!h) { 819 if (++st->bucket >= INSTANCE_BUCKETS) 820 return NULL; 821 822 h = instance_table[st->bucket].first; 823 } 824 return h; 825 } 826 827 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos) 828 { 829 struct hlist_node *head; 830 head = get_first(seq); 831 832 if (head) 833 while (pos && (head = get_next(seq, head))) 834 pos--; 835 return pos ? NULL : head; 836 } 837 838 static void *seq_start(struct seq_file *seq, loff_t *pos) 839 __acquires(instances_lock) 840 { 841 spin_lock(&instances_lock); 842 return get_idx(seq, *pos); 843 } 844 845 static void *seq_next(struct seq_file *s, void *v, loff_t *pos) 846 { 847 (*pos)++; 848 return get_next(s, v); 849 } 850 851 static void seq_stop(struct seq_file *s, void *v) 852 __releases(instances_lock) 853 { 854 spin_unlock(&instances_lock); 855 } 856 857 static int seq_show(struct seq_file *s, void *v) 858 { 859 const struct nfqnl_instance *inst = v; 860 861 return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n", 862 inst->queue_num, 863 inst->peer_pid, inst->queue_total, 864 inst->copy_mode, inst->copy_range, 865 inst->queue_dropped, inst->queue_user_dropped, 866 atomic_read(&inst->id_sequence), 1); 867 } 868 869 static const struct seq_operations nfqnl_seq_ops = { 870 .start = seq_start, 871 .next = seq_next, 872 .stop = seq_stop, 873 .show = seq_show, 874 }; 875 876 static int nfqnl_open(struct inode *inode, struct file *file) 877 { 878 return seq_open_private(file, &nfqnl_seq_ops, 879 sizeof(struct iter_state)); 880 } 881 882 static const struct file_operations nfqnl_file_ops = { 883 .owner = THIS_MODULE, 884 .open = nfqnl_open, 885 .read = seq_read, 886 .llseek = seq_lseek, 887 .release = seq_release_private, 888 }; 889 890 #endif /* PROC_FS */ 891 892 static int __init nfnetlink_queue_init(void) 893 { 894 int i, status = -ENOMEM; 895 896 for (i = 0; i < INSTANCE_BUCKETS; i++) 897 INIT_HLIST_HEAD(&instance_table[i]); 898 899 netlink_register_notifier(&nfqnl_rtnl_notifier); 900 status = nfnetlink_subsys_register(&nfqnl_subsys); 901 if (status < 0) { 902 printk(KERN_ERR "nf_queue: failed to create netlink socket\n"); 903 goto cleanup_netlink_notifier; 904 } 905 906 #ifdef CONFIG_PROC_FS 907 if (!proc_create("nfnetlink_queue", 0440, 908 proc_net_netfilter, &nfqnl_file_ops)) 909 goto cleanup_subsys; 910 #endif 911 912 register_netdevice_notifier(&nfqnl_dev_notifier); 913 return status; 914 915 #ifdef CONFIG_PROC_FS 916 cleanup_subsys: 917 nfnetlink_subsys_unregister(&nfqnl_subsys); 918 #endif 919 cleanup_netlink_notifier: 920 netlink_unregister_notifier(&nfqnl_rtnl_notifier); 921 return status; 922 } 923 924 static void __exit nfnetlink_queue_fini(void) 925 { 926 nf_unregister_queue_handlers(&nfqh); 927 unregister_netdevice_notifier(&nfqnl_dev_notifier); 928 #ifdef CONFIG_PROC_FS 929 remove_proc_entry("nfnetlink_queue", proc_net_netfilter); 930 #endif 931 nfnetlink_subsys_unregister(&nfqnl_subsys); 932 netlink_unregister_notifier(&nfqnl_rtnl_notifier); 933 934 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 935 } 936 937 MODULE_DESCRIPTION("netfilter packet queue handler"); 938 MODULE_AUTHOR("Harald Welte <[email protected]>"); 939 MODULE_LICENSE("GPL"); 940 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE); 941 942 module_init(nfnetlink_queue_init); 943 module_exit(nfnetlink_queue_fini); 944