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 * (C) 2006-2012 Patrick McHardy <kaber@trash.net> 7 * 8 * Based on the old ipv4-only ipt_ULOG.c: 9 * (C) 2000-2004 by Harald Welte <laforge@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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 17 18 #include <linux/module.h> 19 #include <linux/skbuff.h> 20 #include <linux/if_arp.h> 21 #include <linux/init.h> 22 #include <linux/ip.h> 23 #include <linux/ipv6.h> 24 #include <linux/netdevice.h> 25 #include <linux/netfilter.h> 26 #include <linux/netfilter_bridge.h> 27 #include <net/netlink.h> 28 #include <linux/netfilter/nfnetlink.h> 29 #include <linux/netfilter/nfnetlink_log.h> 30 #include <linux/netfilter/nf_conntrack_common.h> 31 #include <linux/spinlock.h> 32 #include <linux/sysctl.h> 33 #include <linux/proc_fs.h> 34 #include <linux/security.h> 35 #include <linux/list.h> 36 #include <linux/slab.h> 37 #include <net/sock.h> 38 #include <net/netfilter/nf_log.h> 39 #include <net/netns/generic.h> 40 #include <net/netfilter/nfnetlink_log.h> 41 42 #include <linux/atomic.h> 43 44 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 45 #include "../bridge/br_private.h" 46 #endif 47 48 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE 49 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */ 50 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */ 51 /* max packet size is limited by 16-bit struct nfattr nfa_len field */ 52 #define NFULNL_COPY_RANGE_MAX (0xFFFF - NLA_HDRLEN) 53 54 #define PRINTR(x, args...) do { if (net_ratelimit()) \ 55 printk(x, ## args); } while (0); 56 57 struct nfulnl_instance { 58 struct hlist_node hlist; /* global list of instances */ 59 spinlock_t lock; 60 atomic_t use; /* use count */ 61 62 unsigned int qlen; /* number of nlmsgs in skb */ 63 struct sk_buff *skb; /* pre-allocatd skb */ 64 struct timer_list timer; 65 struct net *net; 66 struct user_namespace *peer_user_ns; /* User namespace of the peer process */ 67 u32 peer_portid; /* PORTID of the peer process */ 68 69 /* configurable parameters */ 70 unsigned int flushtimeout; /* timeout until queue flush */ 71 unsigned int nlbufsiz; /* netlink buffer allocation size */ 72 unsigned int qthreshold; /* threshold of the queue */ 73 u_int32_t copy_range; 74 u_int32_t seq; /* instance-local sequential counter */ 75 u_int16_t group_num; /* number of this queue */ 76 u_int16_t flags; 77 u_int8_t copy_mode; 78 struct rcu_head rcu; 79 }; 80 81 #define INSTANCE_BUCKETS 16 82 83 static int nfnl_log_net_id __read_mostly; 84 85 struct nfnl_log_net { 86 spinlock_t instances_lock; 87 struct hlist_head instance_table[INSTANCE_BUCKETS]; 88 atomic_t global_seq; 89 }; 90 91 static struct nfnl_log_net *nfnl_log_pernet(struct net *net) 92 { 93 return net_generic(net, nfnl_log_net_id); 94 } 95 96 static inline u_int8_t instance_hashfn(u_int16_t group_num) 97 { 98 return ((group_num & 0xff) % INSTANCE_BUCKETS); 99 } 100 101 static struct nfulnl_instance * 102 __instance_lookup(struct nfnl_log_net *log, u_int16_t group_num) 103 { 104 struct hlist_head *head; 105 struct nfulnl_instance *inst; 106 107 head = &log->instance_table[instance_hashfn(group_num)]; 108 hlist_for_each_entry_rcu(inst, head, hlist) { 109 if (inst->group_num == group_num) 110 return inst; 111 } 112 return NULL; 113 } 114 115 static inline void 116 instance_get(struct nfulnl_instance *inst) 117 { 118 atomic_inc(&inst->use); 119 } 120 121 static struct nfulnl_instance * 122 instance_lookup_get(struct nfnl_log_net *log, u_int16_t group_num) 123 { 124 struct nfulnl_instance *inst; 125 126 rcu_read_lock_bh(); 127 inst = __instance_lookup(log, group_num); 128 if (inst && !atomic_inc_not_zero(&inst->use)) 129 inst = NULL; 130 rcu_read_unlock_bh(); 131 132 return inst; 133 } 134 135 static void nfulnl_instance_free_rcu(struct rcu_head *head) 136 { 137 struct nfulnl_instance *inst = 138 container_of(head, struct nfulnl_instance, rcu); 139 140 put_net(inst->net); 141 kfree(inst); 142 module_put(THIS_MODULE); 143 } 144 145 static void 146 instance_put(struct nfulnl_instance *inst) 147 { 148 if (inst && atomic_dec_and_test(&inst->use)) 149 call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu); 150 } 151 152 static void nfulnl_timer(unsigned long data); 153 154 static struct nfulnl_instance * 155 instance_create(struct net *net, u_int16_t group_num, 156 u32 portid, struct user_namespace *user_ns) 157 { 158 struct nfulnl_instance *inst; 159 struct nfnl_log_net *log = nfnl_log_pernet(net); 160 int err; 161 162 spin_lock_bh(&log->instances_lock); 163 if (__instance_lookup(log, group_num)) { 164 err = -EEXIST; 165 goto out_unlock; 166 } 167 168 inst = kzalloc(sizeof(*inst), GFP_ATOMIC); 169 if (!inst) { 170 err = -ENOMEM; 171 goto out_unlock; 172 } 173 174 if (!try_module_get(THIS_MODULE)) { 175 kfree(inst); 176 err = -EAGAIN; 177 goto out_unlock; 178 } 179 180 INIT_HLIST_NODE(&inst->hlist); 181 spin_lock_init(&inst->lock); 182 /* needs to be two, since we _put() after creation */ 183 atomic_set(&inst->use, 2); 184 185 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst); 186 187 inst->net = get_net(net); 188 inst->peer_user_ns = user_ns; 189 inst->peer_portid = portid; 190 inst->group_num = group_num; 191 192 inst->qthreshold = NFULNL_QTHRESH_DEFAULT; 193 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT; 194 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT; 195 inst->copy_mode = NFULNL_COPY_PACKET; 196 inst->copy_range = NFULNL_COPY_RANGE_MAX; 197 198 hlist_add_head_rcu(&inst->hlist, 199 &log->instance_table[instance_hashfn(group_num)]); 200 201 202 spin_unlock_bh(&log->instances_lock); 203 204 return inst; 205 206 out_unlock: 207 spin_unlock_bh(&log->instances_lock); 208 return ERR_PTR(err); 209 } 210 211 static void __nfulnl_flush(struct nfulnl_instance *inst); 212 213 /* called with BH disabled */ 214 static void 215 __instance_destroy(struct nfulnl_instance *inst) 216 { 217 /* first pull it out of the global list */ 218 hlist_del_rcu(&inst->hlist); 219 220 /* then flush all pending packets from skb */ 221 222 spin_lock(&inst->lock); 223 224 /* lockless readers wont be able to use us */ 225 inst->copy_mode = NFULNL_COPY_DISABLED; 226 227 if (inst->skb) 228 __nfulnl_flush(inst); 229 spin_unlock(&inst->lock); 230 231 /* and finally put the refcount */ 232 instance_put(inst); 233 } 234 235 static inline void 236 instance_destroy(struct nfnl_log_net *log, 237 struct nfulnl_instance *inst) 238 { 239 spin_lock_bh(&log->instances_lock); 240 __instance_destroy(inst); 241 spin_unlock_bh(&log->instances_lock); 242 } 243 244 static int 245 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode, 246 unsigned int range) 247 { 248 int status = 0; 249 250 spin_lock_bh(&inst->lock); 251 252 switch (mode) { 253 case NFULNL_COPY_NONE: 254 case NFULNL_COPY_META: 255 inst->copy_mode = mode; 256 inst->copy_range = 0; 257 break; 258 259 case NFULNL_COPY_PACKET: 260 inst->copy_mode = mode; 261 if (range == 0) 262 range = NFULNL_COPY_RANGE_MAX; 263 inst->copy_range = min_t(unsigned int, 264 range, NFULNL_COPY_RANGE_MAX); 265 break; 266 267 default: 268 status = -EINVAL; 269 break; 270 } 271 272 spin_unlock_bh(&inst->lock); 273 274 return status; 275 } 276 277 static int 278 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz) 279 { 280 int status; 281 282 spin_lock_bh(&inst->lock); 283 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT) 284 status = -ERANGE; 285 else if (nlbufsiz > 131072) 286 status = -ERANGE; 287 else { 288 inst->nlbufsiz = nlbufsiz; 289 status = 0; 290 } 291 spin_unlock_bh(&inst->lock); 292 293 return status; 294 } 295 296 static int 297 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout) 298 { 299 spin_lock_bh(&inst->lock); 300 inst->flushtimeout = timeout; 301 spin_unlock_bh(&inst->lock); 302 303 return 0; 304 } 305 306 static int 307 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh) 308 { 309 spin_lock_bh(&inst->lock); 310 inst->qthreshold = qthresh; 311 spin_unlock_bh(&inst->lock); 312 313 return 0; 314 } 315 316 static int 317 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags) 318 { 319 spin_lock_bh(&inst->lock); 320 inst->flags = flags; 321 spin_unlock_bh(&inst->lock); 322 323 return 0; 324 } 325 326 static struct sk_buff * 327 nfulnl_alloc_skb(struct net *net, u32 peer_portid, unsigned int inst_size, 328 unsigned int pkt_size) 329 { 330 struct sk_buff *skb; 331 unsigned int n; 332 333 /* alloc skb which should be big enough for a whole multipart 334 * message. WARNING: has to be <= 128k due to slab restrictions */ 335 336 n = max(inst_size, pkt_size); 337 skb = nfnetlink_alloc_skb(net, n, peer_portid, GFP_ATOMIC); 338 if (!skb) { 339 if (n > pkt_size) { 340 /* try to allocate only as much as we need for current 341 * packet */ 342 343 skb = nfnetlink_alloc_skb(net, pkt_size, 344 peer_portid, GFP_ATOMIC); 345 } 346 } 347 348 return skb; 349 } 350 351 static void 352 __nfulnl_send(struct nfulnl_instance *inst) 353 { 354 if (inst->qlen > 1) { 355 struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0, 356 NLMSG_DONE, 357 sizeof(struct nfgenmsg), 358 0); 359 if (WARN_ONCE(!nlh, "bad nlskb size: %u, tailroom %d\n", 360 inst->skb->len, skb_tailroom(inst->skb))) { 361 kfree_skb(inst->skb); 362 goto out; 363 } 364 } 365 nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid, 366 MSG_DONTWAIT); 367 out: 368 inst->qlen = 0; 369 inst->skb = NULL; 370 } 371 372 static void 373 __nfulnl_flush(struct nfulnl_instance *inst) 374 { 375 /* timer holds a reference */ 376 if (del_timer(&inst->timer)) 377 instance_put(inst); 378 if (inst->skb) 379 __nfulnl_send(inst); 380 } 381 382 static void 383 nfulnl_timer(unsigned long data) 384 { 385 struct nfulnl_instance *inst = (struct nfulnl_instance *)data; 386 387 spin_lock_bh(&inst->lock); 388 if (inst->skb) 389 __nfulnl_send(inst); 390 spin_unlock_bh(&inst->lock); 391 instance_put(inst); 392 } 393 394 /* This is an inline function, we don't really care about a long 395 * list of arguments */ 396 static inline int 397 __build_packet_message(struct nfnl_log_net *log, 398 struct nfulnl_instance *inst, 399 const struct sk_buff *skb, 400 unsigned int data_len, 401 u_int8_t pf, 402 unsigned int hooknum, 403 const struct net_device *indev, 404 const struct net_device *outdev, 405 const char *prefix, unsigned int plen, 406 const struct nfnl_ct_hook *nfnl_ct, 407 struct nf_conn *ct, enum ip_conntrack_info ctinfo) 408 { 409 struct nfulnl_msg_packet_hdr pmsg; 410 struct nlmsghdr *nlh; 411 struct nfgenmsg *nfmsg; 412 sk_buff_data_t old_tail = inst->skb->tail; 413 struct sock *sk; 414 const unsigned char *hwhdrp; 415 416 nlh = nlmsg_put(inst->skb, 0, 0, 417 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET, 418 sizeof(struct nfgenmsg), 0); 419 if (!nlh) 420 return -1; 421 nfmsg = nlmsg_data(nlh); 422 nfmsg->nfgen_family = pf; 423 nfmsg->version = NFNETLINK_V0; 424 nfmsg->res_id = htons(inst->group_num); 425 426 memset(&pmsg, 0, sizeof(pmsg)); 427 pmsg.hw_protocol = skb->protocol; 428 pmsg.hook = hooknum; 429 430 if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg)) 431 goto nla_put_failure; 432 433 if (prefix && 434 nla_put(inst->skb, NFULA_PREFIX, plen, prefix)) 435 goto nla_put_failure; 436 437 if (indev) { 438 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 439 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV, 440 htonl(indev->ifindex))) 441 goto nla_put_failure; 442 #else 443 if (pf == PF_BRIDGE) { 444 /* Case 1: outdev is physical input device, we need to 445 * look for bridge group (when called from 446 * netfilter_bridge) */ 447 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV, 448 htonl(indev->ifindex)) || 449 /* this is the bridge group "brX" */ 450 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */ 451 nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV, 452 htonl(br_port_get_rcu(indev)->br->dev->ifindex))) 453 goto nla_put_failure; 454 } else { 455 struct net_device *physindev; 456 457 /* Case 2: indev is bridge group, we need to look for 458 * physical device (when called from ipv4) */ 459 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV, 460 htonl(indev->ifindex))) 461 goto nla_put_failure; 462 463 physindev = nf_bridge_get_physindev(skb); 464 if (physindev && 465 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV, 466 htonl(physindev->ifindex))) 467 goto nla_put_failure; 468 } 469 #endif 470 } 471 472 if (outdev) { 473 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 474 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV, 475 htonl(outdev->ifindex))) 476 goto nla_put_failure; 477 #else 478 if (pf == PF_BRIDGE) { 479 /* Case 1: outdev is physical output device, we need to 480 * look for bridge group (when called from 481 * netfilter_bridge) */ 482 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV, 483 htonl(outdev->ifindex)) || 484 /* this is the bridge group "brX" */ 485 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */ 486 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV, 487 htonl(br_port_get_rcu(outdev)->br->dev->ifindex))) 488 goto nla_put_failure; 489 } else { 490 struct net_device *physoutdev; 491 492 /* Case 2: indev is a bridge group, we need to look 493 * for physical device (when called from ipv4) */ 494 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV, 495 htonl(outdev->ifindex))) 496 goto nla_put_failure; 497 498 physoutdev = nf_bridge_get_physoutdev(skb); 499 if (physoutdev && 500 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV, 501 htonl(physoutdev->ifindex))) 502 goto nla_put_failure; 503 } 504 #endif 505 } 506 507 if (skb->mark && 508 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark))) 509 goto nla_put_failure; 510 511 if (indev && skb->dev && 512 skb->mac_header != skb->network_header) { 513 struct nfulnl_msg_packet_hw phw; 514 int len; 515 516 memset(&phw, 0, sizeof(phw)); 517 len = dev_parse_header(skb, phw.hw_addr); 518 if (len > 0) { 519 phw.hw_addrlen = htons(len); 520 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw)) 521 goto nla_put_failure; 522 } 523 } 524 525 if (indev && skb_mac_header_was_set(skb)) { 526 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) || 527 nla_put_be16(inst->skb, NFULA_HWLEN, 528 htons(skb->dev->hard_header_len))) 529 goto nla_put_failure; 530 531 hwhdrp = skb_mac_header(skb); 532 533 if (skb->dev->type == ARPHRD_SIT) 534 hwhdrp -= ETH_HLEN; 535 536 if (hwhdrp >= skb->head && 537 nla_put(inst->skb, NFULA_HWHEADER, 538 skb->dev->hard_header_len, hwhdrp)) 539 goto nla_put_failure; 540 } 541 542 if (skb->tstamp.tv64) { 543 struct nfulnl_msg_packet_timestamp ts; 544 struct timespec64 kts = ktime_to_timespec64(skb->tstamp); 545 ts.sec = cpu_to_be64(kts.tv_sec); 546 ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC); 547 548 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts)) 549 goto nla_put_failure; 550 } 551 552 /* UID */ 553 sk = skb->sk; 554 if (sk && sk_fullsock(sk)) { 555 read_lock_bh(&sk->sk_callback_lock); 556 if (sk->sk_socket && sk->sk_socket->file) { 557 struct file *file = sk->sk_socket->file; 558 const struct cred *cred = file->f_cred; 559 struct user_namespace *user_ns = inst->peer_user_ns; 560 __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid)); 561 __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid)); 562 read_unlock_bh(&sk->sk_callback_lock); 563 if (nla_put_be32(inst->skb, NFULA_UID, uid) || 564 nla_put_be32(inst->skb, NFULA_GID, gid)) 565 goto nla_put_failure; 566 } else 567 read_unlock_bh(&sk->sk_callback_lock); 568 } 569 570 /* local sequence number */ 571 if ((inst->flags & NFULNL_CFG_F_SEQ) && 572 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++))) 573 goto nla_put_failure; 574 575 /* global sequence number */ 576 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) && 577 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL, 578 htonl(atomic_inc_return(&log->global_seq)))) 579 goto nla_put_failure; 580 581 if (ct && nfnl_ct->build(inst->skb, ct, ctinfo, 582 NFULA_CT, NFULA_CT_INFO) < 0) 583 goto nla_put_failure; 584 585 if (data_len) { 586 struct nlattr *nla; 587 int size = nla_attr_size(data_len); 588 589 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) 590 goto nla_put_failure; 591 592 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len)); 593 nla->nla_type = NFULA_PAYLOAD; 594 nla->nla_len = size; 595 596 if (skb_copy_bits(skb, 0, nla_data(nla), data_len)) 597 BUG(); 598 } 599 600 nlh->nlmsg_len = inst->skb->tail - old_tail; 601 return 0; 602 603 nla_put_failure: 604 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n"); 605 return -1; 606 } 607 608 static struct nf_loginfo default_loginfo = { 609 .type = NF_LOG_TYPE_ULOG, 610 .u = { 611 .ulog = { 612 .copy_len = 0xffff, 613 .group = 0, 614 .qthreshold = 1, 615 }, 616 }, 617 }; 618 619 /* log handler for internal netfilter logging api */ 620 void 621 nfulnl_log_packet(struct net *net, 622 u_int8_t pf, 623 unsigned int hooknum, 624 const struct sk_buff *skb, 625 const struct net_device *in, 626 const struct net_device *out, 627 const struct nf_loginfo *li_user, 628 const char *prefix) 629 { 630 size_t size; 631 unsigned int data_len; 632 struct nfulnl_instance *inst; 633 const struct nf_loginfo *li; 634 unsigned int qthreshold; 635 unsigned int plen; 636 struct nfnl_log_net *log = nfnl_log_pernet(net); 637 const struct nfnl_ct_hook *nfnl_ct = NULL; 638 struct nf_conn *ct = NULL; 639 enum ip_conntrack_info uninitialized_var(ctinfo); 640 641 if (li_user && li_user->type == NF_LOG_TYPE_ULOG) 642 li = li_user; 643 else 644 li = &default_loginfo; 645 646 inst = instance_lookup_get(log, li->u.ulog.group); 647 if (!inst) 648 return; 649 650 plen = 0; 651 if (prefix) 652 plen = strlen(prefix) + 1; 653 654 /* FIXME: do we want to make the size calculation conditional based on 655 * what is actually present? way more branches and checks, but more 656 * memory efficient... */ 657 size = nlmsg_total_size(sizeof(struct nfgenmsg)) 658 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr)) 659 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 660 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 661 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 662 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 663 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 664 #endif 665 + nla_total_size(sizeof(u_int32_t)) /* mark */ 666 + nla_total_size(sizeof(u_int32_t)) /* uid */ 667 + nla_total_size(sizeof(u_int32_t)) /* gid */ 668 + nla_total_size(plen) /* prefix */ 669 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw)) 670 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp)) 671 + nla_total_size(sizeof(struct nfgenmsg)); /* NLMSG_DONE */ 672 673 if (in && skb_mac_header_was_set(skb)) { 674 size += nla_total_size(skb->dev->hard_header_len) 675 + nla_total_size(sizeof(u_int16_t)) /* hwtype */ 676 + nla_total_size(sizeof(u_int16_t)); /* hwlen */ 677 } 678 679 spin_lock_bh(&inst->lock); 680 681 if (inst->flags & NFULNL_CFG_F_SEQ) 682 size += nla_total_size(sizeof(u_int32_t)); 683 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) 684 size += nla_total_size(sizeof(u_int32_t)); 685 if (inst->flags & NFULNL_CFG_F_CONNTRACK) { 686 nfnl_ct = rcu_dereference(nfnl_ct_hook); 687 if (nfnl_ct != NULL) { 688 ct = nfnl_ct->get_ct(skb, &ctinfo); 689 if (ct != NULL) 690 size += nfnl_ct->build_size(ct); 691 } 692 } 693 694 qthreshold = inst->qthreshold; 695 /* per-rule qthreshold overrides per-instance */ 696 if (li->u.ulog.qthreshold) 697 if (qthreshold > li->u.ulog.qthreshold) 698 qthreshold = li->u.ulog.qthreshold; 699 700 701 switch (inst->copy_mode) { 702 case NFULNL_COPY_META: 703 case NFULNL_COPY_NONE: 704 data_len = 0; 705 break; 706 707 case NFULNL_COPY_PACKET: 708 if (inst->copy_range > skb->len) 709 data_len = skb->len; 710 else 711 data_len = inst->copy_range; 712 713 size += nla_total_size(data_len); 714 break; 715 716 case NFULNL_COPY_DISABLED: 717 default: 718 goto unlock_and_release; 719 } 720 721 if (inst->skb && size > skb_tailroom(inst->skb)) { 722 /* either the queue len is too high or we don't have 723 * enough room in the skb left. flush to userspace. */ 724 __nfulnl_flush(inst); 725 } 726 727 if (!inst->skb) { 728 inst->skb = nfulnl_alloc_skb(net, inst->peer_portid, 729 inst->nlbufsiz, size); 730 if (!inst->skb) 731 goto alloc_failure; 732 } 733 734 inst->qlen++; 735 736 __build_packet_message(log, inst, skb, data_len, pf, 737 hooknum, in, out, prefix, plen, 738 nfnl_ct, ct, ctinfo); 739 740 if (inst->qlen >= qthreshold) 741 __nfulnl_flush(inst); 742 /* timer_pending always called within inst->lock, so there 743 * is no chance of a race here */ 744 else if (!timer_pending(&inst->timer)) { 745 instance_get(inst); 746 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100); 747 add_timer(&inst->timer); 748 } 749 750 unlock_and_release: 751 spin_unlock_bh(&inst->lock); 752 instance_put(inst); 753 return; 754 755 alloc_failure: 756 /* FIXME: statistics */ 757 goto unlock_and_release; 758 } 759 EXPORT_SYMBOL_GPL(nfulnl_log_packet); 760 761 static int 762 nfulnl_rcv_nl_event(struct notifier_block *this, 763 unsigned long event, void *ptr) 764 { 765 struct netlink_notify *n = ptr; 766 struct nfnl_log_net *log = nfnl_log_pernet(n->net); 767 768 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) { 769 int i; 770 771 /* destroy all instances for this portid */ 772 spin_lock_bh(&log->instances_lock); 773 for (i = 0; i < INSTANCE_BUCKETS; i++) { 774 struct hlist_node *t2; 775 struct nfulnl_instance *inst; 776 struct hlist_head *head = &log->instance_table[i]; 777 778 hlist_for_each_entry_safe(inst, t2, head, hlist) { 779 if (n->portid == inst->peer_portid) 780 __instance_destroy(inst); 781 } 782 } 783 spin_unlock_bh(&log->instances_lock); 784 } 785 return NOTIFY_DONE; 786 } 787 788 static struct notifier_block nfulnl_rtnl_notifier = { 789 .notifier_call = nfulnl_rcv_nl_event, 790 }; 791 792 static int 793 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb, 794 const struct nlmsghdr *nlh, 795 const struct nlattr * const nfqa[]) 796 { 797 return -ENOTSUPP; 798 } 799 800 static struct nf_logger nfulnl_logger __read_mostly = { 801 .name = "nfnetlink_log", 802 .type = NF_LOG_TYPE_ULOG, 803 .logfn = &nfulnl_log_packet, 804 .me = THIS_MODULE, 805 }; 806 807 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = { 808 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) }, 809 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) }, 810 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 }, 811 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 }, 812 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 }, 813 [NFULA_CFG_FLAGS] = { .type = NLA_U16 }, 814 }; 815 816 static int 817 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb, 818 const struct nlmsghdr *nlh, 819 const struct nlattr * const nfula[]) 820 { 821 struct nfgenmsg *nfmsg = nlmsg_data(nlh); 822 u_int16_t group_num = ntohs(nfmsg->res_id); 823 struct nfulnl_instance *inst; 824 struct nfulnl_msg_config_cmd *cmd = NULL; 825 struct net *net = sock_net(ctnl); 826 struct nfnl_log_net *log = nfnl_log_pernet(net); 827 int ret = 0; 828 u16 flags = 0; 829 830 if (nfula[NFULA_CFG_CMD]) { 831 u_int8_t pf = nfmsg->nfgen_family; 832 cmd = nla_data(nfula[NFULA_CFG_CMD]); 833 834 /* Commands without queue context */ 835 switch (cmd->command) { 836 case NFULNL_CFG_CMD_PF_BIND: 837 return nf_log_bind_pf(net, pf, &nfulnl_logger); 838 case NFULNL_CFG_CMD_PF_UNBIND: 839 nf_log_unbind_pf(net, pf); 840 return 0; 841 } 842 } 843 844 inst = instance_lookup_get(log, group_num); 845 if (inst && inst->peer_portid != NETLINK_CB(skb).portid) { 846 ret = -EPERM; 847 goto out_put; 848 } 849 850 /* Check if we support these flags in first place, dependencies should 851 * be there too not to break atomicity. 852 */ 853 if (nfula[NFULA_CFG_FLAGS]) { 854 flags = ntohs(nla_get_be16(nfula[NFULA_CFG_FLAGS])); 855 856 if ((flags & NFULNL_CFG_F_CONNTRACK) && 857 !rcu_access_pointer(nfnl_ct_hook)) { 858 #ifdef CONFIG_MODULES 859 nfnl_unlock(NFNL_SUBSYS_ULOG); 860 request_module("ip_conntrack_netlink"); 861 nfnl_lock(NFNL_SUBSYS_ULOG); 862 if (rcu_access_pointer(nfnl_ct_hook)) { 863 ret = -EAGAIN; 864 goto out_put; 865 } 866 #endif 867 ret = -EOPNOTSUPP; 868 goto out_put; 869 } 870 } 871 872 if (cmd != NULL) { 873 switch (cmd->command) { 874 case NFULNL_CFG_CMD_BIND: 875 if (inst) { 876 ret = -EBUSY; 877 goto out_put; 878 } 879 880 inst = instance_create(net, group_num, 881 NETLINK_CB(skb).portid, 882 sk_user_ns(NETLINK_CB(skb).sk)); 883 if (IS_ERR(inst)) { 884 ret = PTR_ERR(inst); 885 goto out; 886 } 887 break; 888 case NFULNL_CFG_CMD_UNBIND: 889 if (!inst) { 890 ret = -ENODEV; 891 goto out; 892 } 893 894 instance_destroy(log, inst); 895 goto out_put; 896 default: 897 ret = -ENOTSUPP; 898 break; 899 } 900 } else if (!inst) { 901 ret = -ENODEV; 902 goto out; 903 } 904 905 if (nfula[NFULA_CFG_MODE]) { 906 struct nfulnl_msg_config_mode *params = 907 nla_data(nfula[NFULA_CFG_MODE]); 908 909 nfulnl_set_mode(inst, params->copy_mode, 910 ntohl(params->copy_range)); 911 } 912 913 if (nfula[NFULA_CFG_TIMEOUT]) { 914 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]); 915 916 nfulnl_set_timeout(inst, ntohl(timeout)); 917 } 918 919 if (nfula[NFULA_CFG_NLBUFSIZ]) { 920 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]); 921 922 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz)); 923 } 924 925 if (nfula[NFULA_CFG_QTHRESH]) { 926 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]); 927 928 nfulnl_set_qthresh(inst, ntohl(qthresh)); 929 } 930 931 if (nfula[NFULA_CFG_FLAGS]) 932 nfulnl_set_flags(inst, flags); 933 934 out_put: 935 instance_put(inst); 936 out: 937 return ret; 938 } 939 940 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = { 941 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp, 942 .attr_count = NFULA_MAX, }, 943 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config, 944 .attr_count = NFULA_CFG_MAX, 945 .policy = nfula_cfg_policy }, 946 }; 947 948 static const struct nfnetlink_subsystem nfulnl_subsys = { 949 .name = "log", 950 .subsys_id = NFNL_SUBSYS_ULOG, 951 .cb_count = NFULNL_MSG_MAX, 952 .cb = nfulnl_cb, 953 }; 954 955 #ifdef CONFIG_PROC_FS 956 struct iter_state { 957 struct seq_net_private p; 958 unsigned int bucket; 959 }; 960 961 static struct hlist_node *get_first(struct net *net, struct iter_state *st) 962 { 963 struct nfnl_log_net *log; 964 if (!st) 965 return NULL; 966 967 log = nfnl_log_pernet(net); 968 969 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) { 970 struct hlist_head *head = &log->instance_table[st->bucket]; 971 972 if (!hlist_empty(head)) 973 return rcu_dereference_bh(hlist_first_rcu(head)); 974 } 975 return NULL; 976 } 977 978 static struct hlist_node *get_next(struct net *net, struct iter_state *st, 979 struct hlist_node *h) 980 { 981 h = rcu_dereference_bh(hlist_next_rcu(h)); 982 while (!h) { 983 struct nfnl_log_net *log; 984 struct hlist_head *head; 985 986 if (++st->bucket >= INSTANCE_BUCKETS) 987 return NULL; 988 989 log = nfnl_log_pernet(net); 990 head = &log->instance_table[st->bucket]; 991 h = rcu_dereference_bh(hlist_first_rcu(head)); 992 } 993 return h; 994 } 995 996 static struct hlist_node *get_idx(struct net *net, struct iter_state *st, 997 loff_t pos) 998 { 999 struct hlist_node *head; 1000 head = get_first(net, st); 1001 1002 if (head) 1003 while (pos && (head = get_next(net, st, head))) 1004 pos--; 1005 return pos ? NULL : head; 1006 } 1007 1008 static void *seq_start(struct seq_file *s, loff_t *pos) 1009 __acquires(rcu_bh) 1010 { 1011 rcu_read_lock_bh(); 1012 return get_idx(seq_file_net(s), s->private, *pos); 1013 } 1014 1015 static void *seq_next(struct seq_file *s, void *v, loff_t *pos) 1016 { 1017 (*pos)++; 1018 return get_next(seq_file_net(s), s->private, v); 1019 } 1020 1021 static void seq_stop(struct seq_file *s, void *v) 1022 __releases(rcu_bh) 1023 { 1024 rcu_read_unlock_bh(); 1025 } 1026 1027 static int seq_show(struct seq_file *s, void *v) 1028 { 1029 const struct nfulnl_instance *inst = v; 1030 1031 seq_printf(s, "%5u %6u %5u %1u %5u %6u %2u\n", 1032 inst->group_num, 1033 inst->peer_portid, inst->qlen, 1034 inst->copy_mode, inst->copy_range, 1035 inst->flushtimeout, atomic_read(&inst->use)); 1036 1037 return 0; 1038 } 1039 1040 static const struct seq_operations nful_seq_ops = { 1041 .start = seq_start, 1042 .next = seq_next, 1043 .stop = seq_stop, 1044 .show = seq_show, 1045 }; 1046 1047 static int nful_open(struct inode *inode, struct file *file) 1048 { 1049 return seq_open_net(inode, file, &nful_seq_ops, 1050 sizeof(struct iter_state)); 1051 } 1052 1053 static const struct file_operations nful_file_ops = { 1054 .owner = THIS_MODULE, 1055 .open = nful_open, 1056 .read = seq_read, 1057 .llseek = seq_lseek, 1058 .release = seq_release_net, 1059 }; 1060 1061 #endif /* PROC_FS */ 1062 1063 static int __net_init nfnl_log_net_init(struct net *net) 1064 { 1065 unsigned int i; 1066 struct nfnl_log_net *log = nfnl_log_pernet(net); 1067 1068 for (i = 0; i < INSTANCE_BUCKETS; i++) 1069 INIT_HLIST_HEAD(&log->instance_table[i]); 1070 spin_lock_init(&log->instances_lock); 1071 1072 #ifdef CONFIG_PROC_FS 1073 if (!proc_create("nfnetlink_log", 0440, 1074 net->nf.proc_netfilter, &nful_file_ops)) 1075 return -ENOMEM; 1076 #endif 1077 return 0; 1078 } 1079 1080 static void __net_exit nfnl_log_net_exit(struct net *net) 1081 { 1082 #ifdef CONFIG_PROC_FS 1083 remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter); 1084 #endif 1085 nf_log_unset(net, &nfulnl_logger); 1086 } 1087 1088 static struct pernet_operations nfnl_log_net_ops = { 1089 .init = nfnl_log_net_init, 1090 .exit = nfnl_log_net_exit, 1091 .id = &nfnl_log_net_id, 1092 .size = sizeof(struct nfnl_log_net), 1093 }; 1094 1095 static int __init nfnetlink_log_init(void) 1096 { 1097 int status; 1098 1099 status = register_pernet_subsys(&nfnl_log_net_ops); 1100 if (status < 0) { 1101 pr_err("failed to register pernet ops\n"); 1102 goto out; 1103 } 1104 1105 netlink_register_notifier(&nfulnl_rtnl_notifier); 1106 status = nfnetlink_subsys_register(&nfulnl_subsys); 1107 if (status < 0) { 1108 pr_err("failed to create netlink socket\n"); 1109 goto cleanup_netlink_notifier; 1110 } 1111 1112 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger); 1113 if (status < 0) { 1114 pr_err("failed to register logger\n"); 1115 goto cleanup_subsys; 1116 } 1117 1118 return status; 1119 1120 cleanup_subsys: 1121 nfnetlink_subsys_unregister(&nfulnl_subsys); 1122 cleanup_netlink_notifier: 1123 netlink_unregister_notifier(&nfulnl_rtnl_notifier); 1124 unregister_pernet_subsys(&nfnl_log_net_ops); 1125 out: 1126 return status; 1127 } 1128 1129 static void __exit nfnetlink_log_fini(void) 1130 { 1131 nf_log_unregister(&nfulnl_logger); 1132 nfnetlink_subsys_unregister(&nfulnl_subsys); 1133 netlink_unregister_notifier(&nfulnl_rtnl_notifier); 1134 unregister_pernet_subsys(&nfnl_log_net_ops); 1135 } 1136 1137 MODULE_DESCRIPTION("netfilter userspace logging"); 1138 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); 1139 MODULE_LICENSE("GPL"); 1140 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG); 1141 MODULE_ALIAS_NF_LOGGER(AF_INET, 1); 1142 MODULE_ALIAS_NF_LOGGER(AF_INET6, 1); 1143 MODULE_ALIAS_NF_LOGGER(AF_BRIDGE, 1); 1144 1145 module_init(nfnetlink_log_init); 1146 module_exit(nfnetlink_log_fini); 1147