1 /* 2 * This is a module which is used for logging packets to userspace via 3 * nfetlink. 4 * 5 * (C) 2005 by Harald Welte <laforge@netfilter.org> 6 * 7 * Based on the old ipv4-only ipt_ULOG.c: 8 * (C) 2000-2004 by Harald Welte <laforge@netfilter.org> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 */ 14 #include <linux/module.h> 15 #include <linux/skbuff.h> 16 #include <linux/init.h> 17 #include <linux/ip.h> 18 #include <linux/ipv6.h> 19 #include <linux/netdevice.h> 20 #include <linux/netfilter.h> 21 #include <linux/netlink.h> 22 #include <linux/netfilter/nfnetlink.h> 23 #include <linux/netfilter/nfnetlink_log.h> 24 #include <linux/spinlock.h> 25 #include <linux/sysctl.h> 26 #include <linux/proc_fs.h> 27 #include <linux/security.h> 28 #include <linux/list.h> 29 #include <linux/jhash.h> 30 #include <linux/random.h> 31 #include <linux/slab.h> 32 #include <net/sock.h> 33 #include <net/netfilter/nf_log.h> 34 #include <net/netfilter/nfnetlink_log.h> 35 36 #include <asm/atomic.h> 37 38 #ifdef CONFIG_BRIDGE_NETFILTER 39 #include "../bridge/br_private.h" 40 #endif 41 42 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE 43 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */ 44 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */ 45 #define NFULNL_COPY_RANGE_MAX 0xFFFF /* max packet size is limited by 16-bit struct nfattr nfa_len field */ 46 47 #define PRINTR(x, args...) do { if (net_ratelimit()) \ 48 printk(x, ## args); } while (0); 49 50 struct nfulnl_instance { 51 struct hlist_node hlist; /* global list of instances */ 52 spinlock_t lock; 53 atomic_t use; /* use count */ 54 55 unsigned int qlen; /* number of nlmsgs in skb */ 56 struct sk_buff *skb; /* pre-allocatd skb */ 57 struct timer_list timer; 58 int peer_pid; /* PID of the peer process */ 59 60 /* configurable parameters */ 61 unsigned int flushtimeout; /* timeout until queue flush */ 62 unsigned int nlbufsiz; /* netlink buffer allocation size */ 63 unsigned int qthreshold; /* threshold of the queue */ 64 u_int32_t copy_range; 65 u_int32_t seq; /* instance-local sequential counter */ 66 u_int16_t group_num; /* number of this queue */ 67 u_int16_t flags; 68 u_int8_t copy_mode; 69 }; 70 71 static DEFINE_RWLOCK(instances_lock); 72 static atomic_t global_seq; 73 74 #define INSTANCE_BUCKETS 16 75 static struct hlist_head instance_table[INSTANCE_BUCKETS]; 76 static unsigned int hash_init; 77 78 static inline u_int8_t instance_hashfn(u_int16_t group_num) 79 { 80 return ((group_num & 0xff) % INSTANCE_BUCKETS); 81 } 82 83 static struct nfulnl_instance * 84 __instance_lookup(u_int16_t group_num) 85 { 86 struct hlist_head *head; 87 struct hlist_node *pos; 88 struct nfulnl_instance *inst; 89 90 head = &instance_table[instance_hashfn(group_num)]; 91 hlist_for_each_entry(inst, pos, head, hlist) { 92 if (inst->group_num == group_num) 93 return inst; 94 } 95 return NULL; 96 } 97 98 static inline void 99 instance_get(struct nfulnl_instance *inst) 100 { 101 atomic_inc(&inst->use); 102 } 103 104 static struct nfulnl_instance * 105 instance_lookup_get(u_int16_t group_num) 106 { 107 struct nfulnl_instance *inst; 108 109 read_lock_bh(&instances_lock); 110 inst = __instance_lookup(group_num); 111 if (inst) 112 instance_get(inst); 113 read_unlock_bh(&instances_lock); 114 115 return inst; 116 } 117 118 static void 119 instance_put(struct nfulnl_instance *inst) 120 { 121 if (inst && atomic_dec_and_test(&inst->use)) { 122 kfree(inst); 123 module_put(THIS_MODULE); 124 } 125 } 126 127 static void nfulnl_timer(unsigned long data); 128 129 static struct nfulnl_instance * 130 instance_create(u_int16_t group_num, int pid) 131 { 132 struct nfulnl_instance *inst; 133 int err; 134 135 write_lock_bh(&instances_lock); 136 if (__instance_lookup(group_num)) { 137 err = -EEXIST; 138 goto out_unlock; 139 } 140 141 inst = kzalloc(sizeof(*inst), GFP_ATOMIC); 142 if (!inst) { 143 err = -ENOMEM; 144 goto out_unlock; 145 } 146 147 if (!try_module_get(THIS_MODULE)) { 148 kfree(inst); 149 err = -EAGAIN; 150 goto out_unlock; 151 } 152 153 INIT_HLIST_NODE(&inst->hlist); 154 spin_lock_init(&inst->lock); 155 /* needs to be two, since we _put() after creation */ 156 atomic_set(&inst->use, 2); 157 158 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst); 159 160 inst->peer_pid = pid; 161 inst->group_num = group_num; 162 163 inst->qthreshold = NFULNL_QTHRESH_DEFAULT; 164 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT; 165 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT; 166 inst->copy_mode = NFULNL_COPY_PACKET; 167 inst->copy_range = NFULNL_COPY_RANGE_MAX; 168 169 hlist_add_head(&inst->hlist, 170 &instance_table[instance_hashfn(group_num)]); 171 172 write_unlock_bh(&instances_lock); 173 174 return inst; 175 176 out_unlock: 177 write_unlock_bh(&instances_lock); 178 return ERR_PTR(err); 179 } 180 181 static void __nfulnl_flush(struct nfulnl_instance *inst); 182 183 static void 184 __instance_destroy(struct nfulnl_instance *inst) 185 { 186 /* first pull it out of the global list */ 187 hlist_del(&inst->hlist); 188 189 /* then flush all pending packets from skb */ 190 191 spin_lock_bh(&inst->lock); 192 if (inst->skb) 193 __nfulnl_flush(inst); 194 spin_unlock_bh(&inst->lock); 195 196 /* and finally put the refcount */ 197 instance_put(inst); 198 } 199 200 static inline void 201 instance_destroy(struct nfulnl_instance *inst) 202 { 203 write_lock_bh(&instances_lock); 204 __instance_destroy(inst); 205 write_unlock_bh(&instances_lock); 206 } 207 208 static int 209 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode, 210 unsigned int range) 211 { 212 int status = 0; 213 214 spin_lock_bh(&inst->lock); 215 216 switch (mode) { 217 case NFULNL_COPY_NONE: 218 case NFULNL_COPY_META: 219 inst->copy_mode = mode; 220 inst->copy_range = 0; 221 break; 222 223 case NFULNL_COPY_PACKET: 224 inst->copy_mode = mode; 225 inst->copy_range = min_t(unsigned int, 226 range, NFULNL_COPY_RANGE_MAX); 227 break; 228 229 default: 230 status = -EINVAL; 231 break; 232 } 233 234 spin_unlock_bh(&inst->lock); 235 236 return status; 237 } 238 239 static int 240 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz) 241 { 242 int status; 243 244 spin_lock_bh(&inst->lock); 245 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT) 246 status = -ERANGE; 247 else if (nlbufsiz > 131072) 248 status = -ERANGE; 249 else { 250 inst->nlbufsiz = nlbufsiz; 251 status = 0; 252 } 253 spin_unlock_bh(&inst->lock); 254 255 return status; 256 } 257 258 static int 259 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout) 260 { 261 spin_lock_bh(&inst->lock); 262 inst->flushtimeout = timeout; 263 spin_unlock_bh(&inst->lock); 264 265 return 0; 266 } 267 268 static int 269 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh) 270 { 271 spin_lock_bh(&inst->lock); 272 inst->qthreshold = qthresh; 273 spin_unlock_bh(&inst->lock); 274 275 return 0; 276 } 277 278 static int 279 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags) 280 { 281 spin_lock_bh(&inst->lock); 282 inst->flags = flags; 283 spin_unlock_bh(&inst->lock); 284 285 return 0; 286 } 287 288 static struct sk_buff * 289 nfulnl_alloc_skb(unsigned int inst_size, unsigned int pkt_size) 290 { 291 struct sk_buff *skb; 292 unsigned int n; 293 294 /* alloc skb which should be big enough for a whole multipart 295 * message. WARNING: has to be <= 128k due to slab restrictions */ 296 297 n = max(inst_size, pkt_size); 298 skb = alloc_skb(n, GFP_ATOMIC); 299 if (!skb) { 300 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n", 301 inst_size); 302 303 if (n > pkt_size) { 304 /* try to allocate only as much as we need for current 305 * packet */ 306 307 skb = alloc_skb(pkt_size, GFP_ATOMIC); 308 if (!skb) 309 PRINTR("nfnetlink_log: can't even alloc %u " 310 "bytes\n", pkt_size); 311 } 312 } 313 314 return skb; 315 } 316 317 static int 318 __nfulnl_send(struct nfulnl_instance *inst) 319 { 320 int status = -1; 321 322 if (inst->qlen > 1) 323 NLMSG_PUT(inst->skb, 0, 0, 324 NLMSG_DONE, 325 sizeof(struct nfgenmsg)); 326 327 status = nfnetlink_unicast(inst->skb, &init_net, inst->peer_pid, 328 MSG_DONTWAIT); 329 330 inst->qlen = 0; 331 inst->skb = NULL; 332 333 nlmsg_failure: 334 return status; 335 } 336 337 static void 338 __nfulnl_flush(struct nfulnl_instance *inst) 339 { 340 /* timer holds a reference */ 341 if (del_timer(&inst->timer)) 342 instance_put(inst); 343 if (inst->skb) 344 __nfulnl_send(inst); 345 } 346 347 static void 348 nfulnl_timer(unsigned long data) 349 { 350 struct nfulnl_instance *inst = (struct nfulnl_instance *)data; 351 352 spin_lock_bh(&inst->lock); 353 if (inst->skb) 354 __nfulnl_send(inst); 355 spin_unlock_bh(&inst->lock); 356 instance_put(inst); 357 } 358 359 /* This is an inline function, we don't really care about a long 360 * list of arguments */ 361 static inline int 362 __build_packet_message(struct nfulnl_instance *inst, 363 const struct sk_buff *skb, 364 unsigned int data_len, 365 u_int8_t pf, 366 unsigned int hooknum, 367 const struct net_device *indev, 368 const struct net_device *outdev, 369 const struct nf_loginfo *li, 370 const char *prefix, unsigned int plen) 371 { 372 struct nfulnl_msg_packet_hdr pmsg; 373 struct nlmsghdr *nlh; 374 struct nfgenmsg *nfmsg; 375 __be32 tmp_uint; 376 sk_buff_data_t old_tail = inst->skb->tail; 377 378 nlh = NLMSG_PUT(inst->skb, 0, 0, 379 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET, 380 sizeof(struct nfgenmsg)); 381 nfmsg = NLMSG_DATA(nlh); 382 nfmsg->nfgen_family = pf; 383 nfmsg->version = NFNETLINK_V0; 384 nfmsg->res_id = htons(inst->group_num); 385 386 pmsg.hw_protocol = skb->protocol; 387 pmsg.hook = hooknum; 388 389 NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg); 390 391 if (prefix) 392 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix); 393 394 if (indev) { 395 #ifndef CONFIG_BRIDGE_NETFILTER 396 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV, 397 htonl(indev->ifindex)); 398 #else 399 if (pf == PF_BRIDGE) { 400 /* Case 1: outdev is physical input device, we need to 401 * look for bridge group (when called from 402 * netfilter_bridge) */ 403 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV, 404 htonl(indev->ifindex)); 405 /* this is the bridge group "brX" */ 406 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV, 407 htonl(indev->br_port->br->dev->ifindex)); 408 } else { 409 /* Case 2: indev is bridge group, we need to look for 410 * physical device (when called from ipv4) */ 411 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV, 412 htonl(indev->ifindex)); 413 if (skb->nf_bridge && skb->nf_bridge->physindev) 414 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV, 415 htonl(skb->nf_bridge->physindev->ifindex)); 416 } 417 #endif 418 } 419 420 if (outdev) { 421 tmp_uint = htonl(outdev->ifindex); 422 #ifndef CONFIG_BRIDGE_NETFILTER 423 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV, 424 htonl(outdev->ifindex)); 425 #else 426 if (pf == PF_BRIDGE) { 427 /* Case 1: outdev is physical output device, we need to 428 * look for bridge group (when called from 429 * netfilter_bridge) */ 430 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV, 431 htonl(outdev->ifindex)); 432 /* this is the bridge group "brX" */ 433 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV, 434 htonl(outdev->br_port->br->dev->ifindex)); 435 } else { 436 /* Case 2: indev is a bridge group, we need to look 437 * for physical device (when called from ipv4) */ 438 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV, 439 htonl(outdev->ifindex)); 440 if (skb->nf_bridge && skb->nf_bridge->physoutdev) 441 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV, 442 htonl(skb->nf_bridge->physoutdev->ifindex)); 443 } 444 #endif 445 } 446 447 if (skb->mark) 448 NLA_PUT_BE32(inst->skb, NFULA_MARK, htonl(skb->mark)); 449 450 if (indev && skb->dev) { 451 struct nfulnl_msg_packet_hw phw; 452 int len = dev_parse_header(skb, phw.hw_addr); 453 if (len > 0) { 454 phw.hw_addrlen = htons(len); 455 NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw); 456 } 457 } 458 459 if (indev && skb_mac_header_was_set(skb)) { 460 NLA_PUT_BE16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)); 461 NLA_PUT_BE16(inst->skb, NFULA_HWLEN, 462 htons(skb->dev->hard_header_len)); 463 NLA_PUT(inst->skb, NFULA_HWHEADER, skb->dev->hard_header_len, 464 skb_mac_header(skb)); 465 } 466 467 if (skb->tstamp.tv64) { 468 struct nfulnl_msg_packet_timestamp ts; 469 struct timeval tv = ktime_to_timeval(skb->tstamp); 470 ts.sec = cpu_to_be64(tv.tv_sec); 471 ts.usec = cpu_to_be64(tv.tv_usec); 472 473 NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts); 474 } 475 476 /* UID */ 477 if (skb->sk) { 478 read_lock_bh(&skb->sk->sk_callback_lock); 479 if (skb->sk->sk_socket && skb->sk->sk_socket->file) { 480 struct file *file = skb->sk->sk_socket->file; 481 __be32 uid = htonl(file->f_cred->fsuid); 482 __be32 gid = htonl(file->f_cred->fsgid); 483 /* need to unlock here since NLA_PUT may goto */ 484 read_unlock_bh(&skb->sk->sk_callback_lock); 485 NLA_PUT_BE32(inst->skb, NFULA_UID, uid); 486 NLA_PUT_BE32(inst->skb, NFULA_GID, gid); 487 } else 488 read_unlock_bh(&skb->sk->sk_callback_lock); 489 } 490 491 /* local sequence number */ 492 if (inst->flags & NFULNL_CFG_F_SEQ) 493 NLA_PUT_BE32(inst->skb, NFULA_SEQ, htonl(inst->seq++)); 494 495 /* global sequence number */ 496 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) 497 NLA_PUT_BE32(inst->skb, NFULA_SEQ_GLOBAL, 498 htonl(atomic_inc_return(&global_seq))); 499 500 if (data_len) { 501 struct nlattr *nla; 502 int size = nla_attr_size(data_len); 503 504 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) { 505 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n"); 506 goto nlmsg_failure; 507 } 508 509 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len)); 510 nla->nla_type = NFULA_PAYLOAD; 511 nla->nla_len = size; 512 513 if (skb_copy_bits(skb, 0, nla_data(nla), data_len)) 514 BUG(); 515 } 516 517 nlh->nlmsg_len = inst->skb->tail - old_tail; 518 return 0; 519 520 nlmsg_failure: 521 nla_put_failure: 522 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n"); 523 return -1; 524 } 525 526 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0) 527 528 static struct nf_loginfo default_loginfo = { 529 .type = NF_LOG_TYPE_ULOG, 530 .u = { 531 .ulog = { 532 .copy_len = 0xffff, 533 .group = 0, 534 .qthreshold = 1, 535 }, 536 }, 537 }; 538 539 /* log handler for internal netfilter logging api */ 540 void 541 nfulnl_log_packet(u_int8_t pf, 542 unsigned int hooknum, 543 const struct sk_buff *skb, 544 const struct net_device *in, 545 const struct net_device *out, 546 const struct nf_loginfo *li_user, 547 const char *prefix) 548 { 549 unsigned int size, data_len; 550 struct nfulnl_instance *inst; 551 const struct nf_loginfo *li; 552 unsigned int qthreshold; 553 unsigned int plen; 554 555 if (li_user && li_user->type == NF_LOG_TYPE_ULOG) 556 li = li_user; 557 else 558 li = &default_loginfo; 559 560 inst = instance_lookup_get(li->u.ulog.group); 561 if (!inst) 562 return; 563 564 plen = 0; 565 if (prefix) 566 plen = strlen(prefix) + 1; 567 568 /* FIXME: do we want to make the size calculation conditional based on 569 * what is actually present? way more branches and checks, but more 570 * memory efficient... */ 571 size = NLMSG_SPACE(sizeof(struct nfgenmsg)) 572 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr)) 573 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 574 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 575 #ifdef CONFIG_BRIDGE_NETFILTER 576 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 577 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 578 #endif 579 + nla_total_size(sizeof(u_int32_t)) /* mark */ 580 + nla_total_size(sizeof(u_int32_t)) /* uid */ 581 + nla_total_size(sizeof(u_int32_t)) /* gid */ 582 + nla_total_size(plen) /* prefix */ 583 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw)) 584 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp)); 585 586 if (in && skb_mac_header_was_set(skb)) { 587 size += nla_total_size(skb->dev->hard_header_len) 588 + nla_total_size(sizeof(u_int16_t)) /* hwtype */ 589 + nla_total_size(sizeof(u_int16_t)); /* hwlen */ 590 } 591 592 spin_lock_bh(&inst->lock); 593 594 if (inst->flags & NFULNL_CFG_F_SEQ) 595 size += nla_total_size(sizeof(u_int32_t)); 596 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) 597 size += nla_total_size(sizeof(u_int32_t)); 598 599 qthreshold = inst->qthreshold; 600 /* per-rule qthreshold overrides per-instance */ 601 if (li->u.ulog.qthreshold) 602 if (qthreshold > li->u.ulog.qthreshold) 603 qthreshold = li->u.ulog.qthreshold; 604 605 606 switch (inst->copy_mode) { 607 case NFULNL_COPY_META: 608 case NFULNL_COPY_NONE: 609 data_len = 0; 610 break; 611 612 case NFULNL_COPY_PACKET: 613 if (inst->copy_range == 0 614 || inst->copy_range > skb->len) 615 data_len = skb->len; 616 else 617 data_len = inst->copy_range; 618 619 size += nla_total_size(data_len); 620 break; 621 622 default: 623 goto unlock_and_release; 624 } 625 626 if (inst->skb && 627 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) { 628 /* either the queue len is too high or we don't have 629 * enough room in the skb left. flush to userspace. */ 630 __nfulnl_flush(inst); 631 } 632 633 if (!inst->skb) { 634 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size); 635 if (!inst->skb) 636 goto alloc_failure; 637 } 638 639 inst->qlen++; 640 641 __build_packet_message(inst, skb, data_len, pf, 642 hooknum, in, out, li, prefix, plen); 643 644 if (inst->qlen >= qthreshold) 645 __nfulnl_flush(inst); 646 /* timer_pending always called within inst->lock, so there 647 * is no chance of a race here */ 648 else if (!timer_pending(&inst->timer)) { 649 instance_get(inst); 650 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100); 651 add_timer(&inst->timer); 652 } 653 654 unlock_and_release: 655 spin_unlock_bh(&inst->lock); 656 instance_put(inst); 657 return; 658 659 alloc_failure: 660 /* FIXME: statistics */ 661 goto unlock_and_release; 662 } 663 EXPORT_SYMBOL_GPL(nfulnl_log_packet); 664 665 static int 666 nfulnl_rcv_nl_event(struct notifier_block *this, 667 unsigned long event, void *ptr) 668 { 669 struct netlink_notify *n = ptr; 670 671 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) { 672 int i; 673 674 /* destroy all instances for this pid */ 675 write_lock_bh(&instances_lock); 676 for (i = 0; i < INSTANCE_BUCKETS; i++) { 677 struct hlist_node *tmp, *t2; 678 struct nfulnl_instance *inst; 679 struct hlist_head *head = &instance_table[i]; 680 681 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) { 682 if ((net_eq(n->net, &init_net)) && 683 (n->pid == inst->peer_pid)) 684 __instance_destroy(inst); 685 } 686 } 687 write_unlock_bh(&instances_lock); 688 } 689 return NOTIFY_DONE; 690 } 691 692 static struct notifier_block nfulnl_rtnl_notifier = { 693 .notifier_call = nfulnl_rcv_nl_event, 694 }; 695 696 static int 697 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb, 698 const struct nlmsghdr *nlh, 699 const struct nlattr * const nfqa[]) 700 { 701 return -ENOTSUPP; 702 } 703 704 static struct nf_logger nfulnl_logger __read_mostly = { 705 .name = "nfnetlink_log", 706 .logfn = &nfulnl_log_packet, 707 .me = THIS_MODULE, 708 }; 709 710 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = { 711 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) }, 712 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) }, 713 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 }, 714 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 }, 715 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 }, 716 [NFULA_CFG_FLAGS] = { .type = NLA_U16 }, 717 }; 718 719 static int 720 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb, 721 const struct nlmsghdr *nlh, 722 const struct nlattr * const nfula[]) 723 { 724 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); 725 u_int16_t group_num = ntohs(nfmsg->res_id); 726 struct nfulnl_instance *inst; 727 struct nfulnl_msg_config_cmd *cmd = NULL; 728 int ret = 0; 729 730 if (nfula[NFULA_CFG_CMD]) { 731 u_int8_t pf = nfmsg->nfgen_family; 732 cmd = nla_data(nfula[NFULA_CFG_CMD]); 733 734 /* Commands without queue context */ 735 switch (cmd->command) { 736 case NFULNL_CFG_CMD_PF_BIND: 737 return nf_log_bind_pf(pf, &nfulnl_logger); 738 case NFULNL_CFG_CMD_PF_UNBIND: 739 nf_log_unbind_pf(pf); 740 return 0; 741 } 742 } 743 744 inst = instance_lookup_get(group_num); 745 if (inst && inst->peer_pid != NETLINK_CB(skb).pid) { 746 ret = -EPERM; 747 goto out_put; 748 } 749 750 if (cmd != NULL) { 751 switch (cmd->command) { 752 case NFULNL_CFG_CMD_BIND: 753 if (inst) { 754 ret = -EBUSY; 755 goto out_put; 756 } 757 758 inst = instance_create(group_num, 759 NETLINK_CB(skb).pid); 760 if (IS_ERR(inst)) { 761 ret = PTR_ERR(inst); 762 goto out; 763 } 764 break; 765 case NFULNL_CFG_CMD_UNBIND: 766 if (!inst) { 767 ret = -ENODEV; 768 goto out; 769 } 770 771 instance_destroy(inst); 772 goto out_put; 773 default: 774 ret = -ENOTSUPP; 775 break; 776 } 777 } 778 779 if (nfula[NFULA_CFG_MODE]) { 780 struct nfulnl_msg_config_mode *params; 781 params = nla_data(nfula[NFULA_CFG_MODE]); 782 783 if (!inst) { 784 ret = -ENODEV; 785 goto out; 786 } 787 nfulnl_set_mode(inst, params->copy_mode, 788 ntohl(params->copy_range)); 789 } 790 791 if (nfula[NFULA_CFG_TIMEOUT]) { 792 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]); 793 794 if (!inst) { 795 ret = -ENODEV; 796 goto out; 797 } 798 nfulnl_set_timeout(inst, ntohl(timeout)); 799 } 800 801 if (nfula[NFULA_CFG_NLBUFSIZ]) { 802 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]); 803 804 if (!inst) { 805 ret = -ENODEV; 806 goto out; 807 } 808 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz)); 809 } 810 811 if (nfula[NFULA_CFG_QTHRESH]) { 812 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]); 813 814 if (!inst) { 815 ret = -ENODEV; 816 goto out; 817 } 818 nfulnl_set_qthresh(inst, ntohl(qthresh)); 819 } 820 821 if (nfula[NFULA_CFG_FLAGS]) { 822 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]); 823 824 if (!inst) { 825 ret = -ENODEV; 826 goto out; 827 } 828 nfulnl_set_flags(inst, ntohs(flags)); 829 } 830 831 out_put: 832 instance_put(inst); 833 out: 834 return ret; 835 } 836 837 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = { 838 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp, 839 .attr_count = NFULA_MAX, }, 840 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config, 841 .attr_count = NFULA_CFG_MAX, 842 .policy = nfula_cfg_policy }, 843 }; 844 845 static const struct nfnetlink_subsystem nfulnl_subsys = { 846 .name = "log", 847 .subsys_id = NFNL_SUBSYS_ULOG, 848 .cb_count = NFULNL_MSG_MAX, 849 .cb = nfulnl_cb, 850 }; 851 852 #ifdef CONFIG_PROC_FS 853 struct iter_state { 854 unsigned int bucket; 855 }; 856 857 static struct hlist_node *get_first(struct iter_state *st) 858 { 859 if (!st) 860 return NULL; 861 862 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) { 863 if (!hlist_empty(&instance_table[st->bucket])) 864 return instance_table[st->bucket].first; 865 } 866 return NULL; 867 } 868 869 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h) 870 { 871 h = h->next; 872 while (!h) { 873 if (++st->bucket >= INSTANCE_BUCKETS) 874 return NULL; 875 876 h = instance_table[st->bucket].first; 877 } 878 return h; 879 } 880 881 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos) 882 { 883 struct hlist_node *head; 884 head = get_first(st); 885 886 if (head) 887 while (pos && (head = get_next(st, head))) 888 pos--; 889 return pos ? NULL : head; 890 } 891 892 static void *seq_start(struct seq_file *seq, loff_t *pos) 893 __acquires(instances_lock) 894 { 895 read_lock_bh(&instances_lock); 896 return get_idx(seq->private, *pos); 897 } 898 899 static void *seq_next(struct seq_file *s, void *v, loff_t *pos) 900 { 901 (*pos)++; 902 return get_next(s->private, v); 903 } 904 905 static void seq_stop(struct seq_file *s, void *v) 906 __releases(instances_lock) 907 { 908 read_unlock_bh(&instances_lock); 909 } 910 911 static int seq_show(struct seq_file *s, void *v) 912 { 913 const struct nfulnl_instance *inst = v; 914 915 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n", 916 inst->group_num, 917 inst->peer_pid, inst->qlen, 918 inst->copy_mode, inst->copy_range, 919 inst->flushtimeout, atomic_read(&inst->use)); 920 } 921 922 static const struct seq_operations nful_seq_ops = { 923 .start = seq_start, 924 .next = seq_next, 925 .stop = seq_stop, 926 .show = seq_show, 927 }; 928 929 static int nful_open(struct inode *inode, struct file *file) 930 { 931 return seq_open_private(file, &nful_seq_ops, 932 sizeof(struct iter_state)); 933 } 934 935 static const struct file_operations nful_file_ops = { 936 .owner = THIS_MODULE, 937 .open = nful_open, 938 .read = seq_read, 939 .llseek = seq_lseek, 940 .release = seq_release_private, 941 }; 942 943 #endif /* PROC_FS */ 944 945 static int __init nfnetlink_log_init(void) 946 { 947 int i, status = -ENOMEM; 948 949 for (i = 0; i < INSTANCE_BUCKETS; i++) 950 INIT_HLIST_HEAD(&instance_table[i]); 951 952 /* it's not really all that important to have a random value, so 953 * we can do this from the init function, even if there hasn't 954 * been that much entropy yet */ 955 get_random_bytes(&hash_init, sizeof(hash_init)); 956 957 netlink_register_notifier(&nfulnl_rtnl_notifier); 958 status = nfnetlink_subsys_register(&nfulnl_subsys); 959 if (status < 0) { 960 printk(KERN_ERR "log: failed to create netlink socket\n"); 961 goto cleanup_netlink_notifier; 962 } 963 964 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger); 965 if (status < 0) { 966 printk(KERN_ERR "log: failed to register logger\n"); 967 goto cleanup_subsys; 968 } 969 970 #ifdef CONFIG_PROC_FS 971 if (!proc_create("nfnetlink_log", 0440, 972 proc_net_netfilter, &nful_file_ops)) 973 goto cleanup_logger; 974 #endif 975 return status; 976 977 #ifdef CONFIG_PROC_FS 978 cleanup_logger: 979 nf_log_unregister(&nfulnl_logger); 980 #endif 981 cleanup_subsys: 982 nfnetlink_subsys_unregister(&nfulnl_subsys); 983 cleanup_netlink_notifier: 984 netlink_unregister_notifier(&nfulnl_rtnl_notifier); 985 return status; 986 } 987 988 static void __exit nfnetlink_log_fini(void) 989 { 990 nf_log_unregister(&nfulnl_logger); 991 #ifdef CONFIG_PROC_FS 992 remove_proc_entry("nfnetlink_log", proc_net_netfilter); 993 #endif 994 nfnetlink_subsys_unregister(&nfulnl_subsys); 995 netlink_unregister_notifier(&nfulnl_rtnl_notifier); 996 } 997 998 MODULE_DESCRIPTION("netfilter userspace logging"); 999 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); 1000 MODULE_LICENSE("GPL"); 1001 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG); 1002 1003 module_init(nfnetlink_log_init); 1004 module_exit(nfnetlink_log_fini); 1005