net/netfilter/nfnetlink_log.c

   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/if_arp.h>
  17 #include <linux/init.h>
  18 #include <linux/ip.h>
  19 #include <linux/ipv6.h>
  20 #include <linux/netdevice.h>
  21 #include <linux/netfilter.h>
  22 #include <linux/netlink.h>
  23 #include <linux/netfilter/nfnetlink.h>
  24 #include <linux/netfilter/nfnetlink_log.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/sysctl.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/security.h>
  29 #include <linux/list.h>
  30 #include <linux/jhash.h>
  31 #include <linux/random.h>
  32 #include <linux/slab.h>
  33 #include <net/sock.h>
  34 #include <net/netfilter/nf_log.h>
  35 #include <net/netfilter/nfnetlink_log.h>
  36
  37 #include <linux/atomic.h>
  38
  39 #ifdef CONFIG_BRIDGE_NETFILTER
  40 #include "../bridge/br_private.h"
  41 #endif
  42
  43 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
  44 #define NFULNL_TIMEOUT_DEFAULT  100     /* every second */
  45 #define NFULNL_QTHRESH_DEFAULT  100     /* 100 packets */
  46 #define NFULNL_COPY_RANGE_MAX   0xFFFF  /* max packet size is limited by 16-bit struct nfattr nfa_len field */
  47
  48 #define PRINTR(x, args...)      do { if (net_ratelimit()) \
  49                                      printk(x, ## args); } while (0);
  50
  51 struct nfulnl_instance {
  52         struct hlist_node hlist;        /* global list of instances */
  53         spinlock_t lock;
  54         atomic_t use;                   /* use count */
  55
  56         unsigned int qlen;              /* number of nlmsgs in skb */
  57         struct sk_buff *skb;            /* pre-allocatd skb */
  58         struct timer_list timer;
  59         struct user_namespace *peer_user_ns;    /* User namespace of the peer process */
  60         int peer_portid;                        /* PORTID of the peer process */
  61
  62         /* configurable parameters */
  63         unsigned int flushtimeout;      /* timeout until queue flush */
  64         unsigned int nlbufsiz;          /* netlink buffer allocation size */
  65         unsigned int qthreshold;        /* threshold of the queue */
  66         u_int32_t copy_range;
  67         u_int32_t seq;                  /* instance-local sequential counter */
  68         u_int16_t group_num;            /* number of this queue */
  69         u_int16_t flags;
  70         u_int8_t copy_mode;
  71         struct rcu_head rcu;
  72 };
  73
  74 static DEFINE_SPINLOCK(instances_lock);
  75 static atomic_t global_seq;
  76
  77 #define INSTANCE_BUCKETS        16
  78 static struct hlist_head instance_table[INSTANCE_BUCKETS];
  79 static unsigned int hash_init;
  80
  81 static inline u_int8_t instance_hashfn(u_int16_t group_num)
  82 {
  83         return ((group_num & 0xff) % INSTANCE_BUCKETS);
  84 }
  85
  86 static struct nfulnl_instance *
  87 __instance_lookup(u_int16_t group_num)
  88 {
  89         struct hlist_head *head;
  90         struct hlist_node *pos;
  91         struct nfulnl_instance *inst;
  92
  93         head = &instance_table[instance_hashfn(group_num)];
  94         hlist_for_each_entry_rcu(inst, pos, head, hlist) {
  95                 if (inst->group_num == group_num)
  96                         return inst;
  97         }
  98         return NULL;
  99 }
 100
 101 static inline void
 102 instance_get(struct nfulnl_instance *inst)
 103 {
 104         atomic_inc(&inst->use);
 105 }
 106
 107 static struct nfulnl_instance *
 108 instance_lookup_get(u_int16_t group_num)
 109 {
 110         struct nfulnl_instance *inst;
 111
 112         rcu_read_lock_bh();
 113         inst = __instance_lookup(group_num);
 114         if (inst && !atomic_inc_not_zero(&inst->use))
 115                 inst = NULL;
 116         rcu_read_unlock_bh();
 117
 118         return inst;
 119 }
 120
 121 static void nfulnl_instance_free_rcu(struct rcu_head *head)
 122 {
 123         kfree(container_of(head, struct nfulnl_instance, rcu));
 124         module_put(THIS_MODULE);
 125 }
 126
 127 static void
 128 instance_put(struct nfulnl_instance *inst)
 129 {
 130         if (inst && atomic_dec_and_test(&inst->use))
 131                 call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu);
 132 }
 133
 134 static void nfulnl_timer(unsigned long data);
 135
 136 static struct nfulnl_instance *
 137 instance_create(u_int16_t group_num, int portid, struct user_namespace *user_ns)
 138 {
 139         struct nfulnl_instance *inst;
 140         int err;
 141
 142         spin_lock_bh(&instances_lock);
 143         if (__instance_lookup(group_num)) {
 144                 err = -EEXIST;
 145                 goto out_unlock;
 146         }
 147
 148         inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
 149         if (!inst) {
 150                 err = -ENOMEM;
 151                 goto out_unlock;
 152         }
 153
 154         if (!try_module_get(THIS_MODULE)) {
 155                 kfree(inst);
 156                 err = -EAGAIN;
 157                 goto out_unlock;
 158         }
 159
 160         INIT_HLIST_NODE(&inst->hlist);
 161         spin_lock_init(&inst->lock);
 162         /* needs to be two, since we _put() after creation */
 163         atomic_set(&inst->use, 2);
 164
 165         setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
 166
 167         inst->peer_user_ns = user_ns;
 168         inst->peer_portid = portid;
 169         inst->group_num = group_num;
 170
 171         inst->qthreshold        = NFULNL_QTHRESH_DEFAULT;
 172         inst->flushtimeout      = NFULNL_TIMEOUT_DEFAULT;
 173         inst->nlbufsiz          = NFULNL_NLBUFSIZ_DEFAULT;
 174         inst->copy_mode         = NFULNL_COPY_PACKET;
 175         inst->copy_range        = NFULNL_COPY_RANGE_MAX;
 176
 177         hlist_add_head_rcu(&inst->hlist,
 178                        &instance_table[instance_hashfn(group_num)]);
 179
 180         spin_unlock_bh(&instances_lock);
 181
 182         return inst;
 183
 184 out_unlock:
 185         spin_unlock_bh(&instances_lock);
 186         return ERR_PTR(err);
 187 }
 188
 189 static void __nfulnl_flush(struct nfulnl_instance *inst);
 190
 191 /* called with BH disabled */
 192 static void
 193 __instance_destroy(struct nfulnl_instance *inst)
 194 {
 195         /* first pull it out of the global list */
 196         hlist_del_rcu(&inst->hlist);
 197
 198         /* then flush all pending packets from skb */
 199
 200         spin_lock(&inst->lock);
 201
 202         /* lockless readers wont be able to use us */
 203         inst->copy_mode = NFULNL_COPY_DISABLED;
 204
 205         if (inst->skb)
 206                 __nfulnl_flush(inst);
 207         spin_unlock(&inst->lock);
 208
 209         /* and finally put the refcount */
 210         instance_put(inst);
 211 }
 212
 213 static inline void
 214 instance_destroy(struct nfulnl_instance *inst)
 215 {
 216         spin_lock_bh(&instances_lock);
 217         __instance_destroy(inst);
 218         spin_unlock_bh(&instances_lock);
 219 }
 220
 221 static int
 222 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
 223                   unsigned int range)
 224 {
 225         int status = 0;
 226
 227         spin_lock_bh(&inst->lock);
 228
 229         switch (mode) {
 230         case NFULNL_COPY_NONE:
 231         case NFULNL_COPY_META:
 232                 inst->copy_mode = mode;
 233                 inst->copy_range = 0;
 234                 break;
 235
 236         case NFULNL_COPY_PACKET:
 237                 inst->copy_mode = mode;
 238                 inst->copy_range = min_t(unsigned int,
 239                                          range, NFULNL_COPY_RANGE_MAX);
 240                 break;
 241
 242         default:
 243                 status = -EINVAL;
 244                 break;
 245         }
 246
 247         spin_unlock_bh(&inst->lock);
 248
 249         return status;
 250 }
 251
 252 static int
 253 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
 254 {
 255         int status;
 256
 257         spin_lock_bh(&inst->lock);
 258         if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
 259                 status = -ERANGE;
 260         else if (nlbufsiz > 131072)
 261                 status = -ERANGE;
 262         else {
 263                 inst->nlbufsiz = nlbufsiz;
 264                 status = 0;
 265         }
 266         spin_unlock_bh(&inst->lock);
 267
 268         return status;
 269 }
 270
 271 static int
 272 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
 273 {
 274         spin_lock_bh(&inst->lock);
 275         inst->flushtimeout = timeout;
 276         spin_unlock_bh(&inst->lock);
 277
 278         return 0;
 279 }
 280
 281 static int
 282 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
 283 {
 284         spin_lock_bh(&inst->lock);
 285         inst->qthreshold = qthresh;
 286         spin_unlock_bh(&inst->lock);
 287
 288         return 0;
 289 }
 290
 291 static int
 292 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
 293 {
 294         spin_lock_bh(&inst->lock);
 295         inst->flags = flags;
 296         spin_unlock_bh(&inst->lock);
 297
 298         return 0;
 299 }
 300
 301 static struct sk_buff *
 302 nfulnl_alloc_skb(unsigned int inst_size, unsigned int pkt_size)
 303 {
 304         struct sk_buff *skb;
 305         unsigned int n;
 306
 307         /* alloc skb which should be big enough for a whole multipart
 308          * message.  WARNING: has to be <= 128k due to slab restrictions */
 309
 310         n = max(inst_size, pkt_size);
 311         skb = alloc_skb(n, GFP_ATOMIC);
 312         if (!skb) {
 313                 if (n > pkt_size) {
 314                         /* try to allocate only as much as we need for current
 315                          * packet */
 316
 317                         skb = alloc_skb(pkt_size, GFP_ATOMIC);
 318                         if (!skb)
 319                                 pr_err("nfnetlink_log: can't even alloc %u bytes\n",
 320                                        pkt_size);
 321                 }
 322         }
 323
 324         return skb;
 325 }
 326
 327 static int
 328 __nfulnl_send(struct nfulnl_instance *inst)
 329 {
 330         int status = -1;
 331
 332         if (inst->qlen > 1) {
 333                 struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
 334                                                  NLMSG_DONE,
 335                                                  sizeof(struct nfgenmsg),
 336                                                  0);
 337                 if (!nlh)
 338                         goto out;
 339         }
 340         status = nfnetlink_unicast(inst->skb, &init_net, inst->peer_portid,
 341                                    MSG_DONTWAIT);
 342
 343         inst->qlen = 0;
 344         inst->skb = NULL;
 345 out:
 346         return status;
 347 }
 348
 349 static void
 350 __nfulnl_flush(struct nfulnl_instance *inst)
 351 {
 352         /* timer holds a reference */
 353         if (del_timer(&inst->timer))
 354                 instance_put(inst);
 355         if (inst->skb)
 356                 __nfulnl_send(inst);
 357 }
 358
 359 static void
 360 nfulnl_timer(unsigned long data)
 361 {
 362         struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
 363
 364         spin_lock_bh(&inst->lock);
 365         if (inst->skb)
 366                 __nfulnl_send(inst);
 367         spin_unlock_bh(&inst->lock);
 368         instance_put(inst);
 369 }
 370
 371 /* This is an inline function, we don't really care about a long
 372  * list of arguments */
 373 static inline int
 374 __build_packet_message(struct nfulnl_instance *inst,
 375                         const struct sk_buff *skb,
 376                         unsigned int data_len,
 377                         u_int8_t pf,
 378                         unsigned int hooknum,
 379                         const struct net_device *indev,
 380                         const struct net_device *outdev,
 381                         const char *prefix, unsigned int plen)
 382 {
 383         struct nfulnl_msg_packet_hdr pmsg;
 384         struct nlmsghdr *nlh;
 385         struct nfgenmsg *nfmsg;
 386         sk_buff_data_t old_tail = inst->skb->tail;
 387         struct sock *sk;
 388         const unsigned char *hwhdrp;
 389
 390         nlh = nlmsg_put(inst->skb, 0, 0,
 391                         NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
 392                         sizeof(struct nfgenmsg), 0);
 393         if (!nlh)
 394                 return -1;
 395         nfmsg = nlmsg_data(nlh);
 396         nfmsg->nfgen_family = pf;
 397         nfmsg->version = NFNETLINK_V0;
 398         nfmsg->res_id = htons(inst->group_num);
 399
 400         pmsg.hw_protocol        = skb->protocol;
 401         pmsg.hook               = hooknum;
 402
 403         if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
 404                 goto nla_put_failure;
 405
 406         if (prefix &&
 407             nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
 408                 goto nla_put_failure;
 409
 410         if (indev) {
 411 #ifndef CONFIG_BRIDGE_NETFILTER
 412                 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
 413                                  htonl(indev->ifindex)))
 414                         goto nla_put_failure;
 415 #else
 416                 if (pf == PF_BRIDGE) {
 417                         /* Case 1: outdev is physical input device, we need to
 418                          * look for bridge group (when called from
 419                          * netfilter_bridge) */
 420                         if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
 421                                          htonl(indev->ifindex)) ||
 422                         /* this is the bridge group "brX" */
 423                         /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
 424                             nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
 425                                          htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
 426                                 goto nla_put_failure;
 427                 } else {
 428                         /* Case 2: indev is bridge group, we need to look for
 429                          * physical device (when called from ipv4) */
 430                         if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
 431                                          htonl(indev->ifindex)))
 432                                 goto nla_put_failure;
 433                         if (skb->nf_bridge && skb->nf_bridge->physindev &&
 434                             nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
 435                                          htonl(skb->nf_bridge->physindev->ifindex)))
 436                                 goto nla_put_failure;
 437                 }
 438 #endif
 439         }
 440
 441         if (outdev) {
 442 #ifndef CONFIG_BRIDGE_NETFILTER
 443                 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
 444                                  htonl(outdev->ifindex)))
 445                         goto nla_put_failure;
 446 #else
 447                 if (pf == PF_BRIDGE) {
 448                         /* Case 1: outdev is physical output device, we need to
 449                          * look for bridge group (when called from
 450                          * netfilter_bridge) */
 451                         if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
 452                                          htonl(outdev->ifindex)) ||
 453                         /* this is the bridge group "brX" */
 454                         /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
 455                             nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
 456                                          htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
 457                                 goto nla_put_failure;
 458                 } else {
 459                         /* Case 2: indev is a bridge group, we need to look
 460                          * for physical device (when called from ipv4) */
 461                         if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
 462                                          htonl(outdev->ifindex)))
 463                                 goto nla_put_failure;
 464                         if (skb->nf_bridge && skb->nf_bridge->physoutdev &&
 465                             nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
 466                                          htonl(skb->nf_bridge->physoutdev->ifindex)))
 467                                 goto nla_put_failure;
 468                 }
 469 #endif
 470         }
 471
 472         if (skb->mark &&
 473             nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
 474                 goto nla_put_failure;
 475
 476         if (indev && skb->dev &&
 477             skb->mac_header != skb->network_header) {
 478                 struct nfulnl_msg_packet_hw phw;
 479                 int len = dev_parse_header(skb, phw.hw_addr);
 480                 if (len > 0) {
 481                         phw.hw_addrlen = htons(len);
 482                         if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
 483                                 goto nla_put_failure;
 484                 }
 485         }
 486
 487         if (indev && skb_mac_header_was_set(skb)) {
 488                 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
 489                     nla_put_be16(inst->skb, NFULA_HWLEN,
 490                                  htons(skb->dev->hard_header_len)))
 491                         goto nla_put_failure;
 492
 493                 hwhdrp = skb_mac_header(skb);
 494
 495                 if (skb->dev->type == ARPHRD_SIT)
 496                         hwhdrp -= ETH_HLEN;
 497
 498                 if (hwhdrp >= skb->head &&
 499                     nla_put(inst->skb, NFULA_HWHEADER,
 500                             skb->dev->hard_header_len, hwhdrp))
 501                         goto nla_put_failure;
 502         }
 503
 504         if (skb->tstamp.tv64) {
 505                 struct nfulnl_msg_packet_timestamp ts;
 506                 struct timeval tv = ktime_to_timeval(skb->tstamp);
 507                 ts.sec = cpu_to_be64(tv.tv_sec);
 508                 ts.usec = cpu_to_be64(tv.tv_usec);
 509
 510                 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
 511                         goto nla_put_failure;
 512         }
 513
 514         /* UID */
 515         sk = skb->sk;
 516         if (sk && sk->sk_state != TCP_TIME_WAIT) {
 517                 read_lock_bh(&sk->sk_callback_lock);
 518                 if (sk->sk_socket && sk->sk_socket->file) {
 519                         struct file *file = sk->sk_socket->file;
 520                         const struct cred *cred = file->f_cred;
 521                         struct user_namespace *user_ns = inst->peer_user_ns;
 522                         __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
 523                         __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
 524                         read_unlock_bh(&sk->sk_callback_lock);
 525                         if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
 526                             nla_put_be32(inst->skb, NFULA_GID, gid))
 527                                 goto nla_put_failure;
 528                 } else
 529                         read_unlock_bh(&sk->sk_callback_lock);
 530         }
 531
 532         /* local sequence number */
 533         if ((inst->flags & NFULNL_CFG_F_SEQ) &&
 534             nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
 535                 goto nla_put_failure;
 536
 537         /* global sequence number */
 538         if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
 539             nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
 540                          htonl(atomic_inc_return(&global_seq))))
 541                 goto nla_put_failure;
 542
 543         if (data_len) {
 544                 struct nlattr *nla;
 545                 int size = nla_attr_size(data_len);
 546
 547                 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
 548                         printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
 549                         return -1;
 550                 }
 551
 552                 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
 553                 nla->nla_type = NFULA_PAYLOAD;
 554                 nla->nla_len = size;
 555
 556                 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
 557                         BUG();
 558         }
 559
 560         nlh->nlmsg_len = inst->skb->tail - old_tail;
 561         return 0;
 562
 563 nla_put_failure:
 564         PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
 565         return -1;
 566 }
 567
 568 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 569
 570 static struct nf_loginfo default_loginfo = {
 571         .type =         NF_LOG_TYPE_ULOG,
 572         .u = {
 573                 .ulog = {
 574                         .copy_len       = 0xffff,
 575                         .group          = 0,
 576                         .qthreshold     = 1,
 577                 },
 578         },
 579 };
 580
 581 /* log handler for internal netfilter logging api */
 582 void
 583 nfulnl_log_packet(u_int8_t pf,
 584                   unsigned int hooknum,
 585                   const struct sk_buff *skb,
 586                   const struct net_device *in,
 587                   const struct net_device *out,
 588                   const struct nf_loginfo *li_user,
 589                   const char *prefix)
 590 {
 591         unsigned int size, data_len;
 592         struct nfulnl_instance *inst;
 593         const struct nf_loginfo *li;
 594         unsigned int qthreshold;
 595         unsigned int plen;
 596
 597         if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
 598                 li = li_user;
 599         else
 600                 li = &default_loginfo;
 601
 602         inst = instance_lookup_get(li->u.ulog.group);
 603         if (!inst)
 604                 return;
 605
 606         plen = 0;
 607         if (prefix)
 608                 plen = strlen(prefix) + 1;
 609
 610         /* FIXME: do we want to make the size calculation conditional based on
 611          * what is actually present?  way more branches and checks, but more
 612          * memory efficient... */
 613         size =    NLMSG_SPACE(sizeof(struct nfgenmsg))
 614                 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
 615                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 616                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 617 #ifdef CONFIG_BRIDGE_NETFILTER
 618                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 619                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 620 #endif
 621                 + nla_total_size(sizeof(u_int32_t))     /* mark */
 622                 + nla_total_size(sizeof(u_int32_t))     /* uid */
 623                 + nla_total_size(sizeof(u_int32_t))     /* gid */
 624                 + nla_total_size(plen)                  /* prefix */
 625                 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
 626                 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
 627
 628         if (in && skb_mac_header_was_set(skb)) {
 629                 size +=   nla_total_size(skb->dev->hard_header_len)
 630                         + nla_total_size(sizeof(u_int16_t))     /* hwtype */
 631                         + nla_total_size(sizeof(u_int16_t));    /* hwlen */
 632         }
 633
 634         spin_lock_bh(&inst->lock);
 635
 636         if (inst->flags & NFULNL_CFG_F_SEQ)
 637                 size += nla_total_size(sizeof(u_int32_t));
 638         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
 639                 size += nla_total_size(sizeof(u_int32_t));
 640
 641         qthreshold = inst->qthreshold;
 642         /* per-rule qthreshold overrides per-instance */
 643         if (li->u.ulog.qthreshold)
 644                 if (qthreshold > li->u.ulog.qthreshold)
 645                         qthreshold = li->u.ulog.qthreshold;
 646
 647
 648         switch (inst->copy_mode) {
 649         case NFULNL_COPY_META:
 650         case NFULNL_COPY_NONE:
 651                 data_len = 0;
 652                 break;
 653
 654         case NFULNL_COPY_PACKET:
 655                 if (inst->copy_range == 0
 656                     || inst->copy_range > skb->len)
 657                         data_len = skb->len;
 658                 else
 659                         data_len = inst->copy_range;
 660
 661                 size += nla_total_size(data_len);
 662                 break;
 663
 664         case NFULNL_COPY_DISABLED:
 665         default:
 666                 goto unlock_and_release;
 667         }
 668
 669         if (inst->skb &&
 670             size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
 671                 /* either the queue len is too high or we don't have
 672                  * enough room in the skb left. flush to userspace. */
 673                 __nfulnl_flush(inst);
 674         }
 675
 676         if (!inst->skb) {
 677                 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
 678                 if (!inst->skb)
 679                         goto alloc_failure;
 680         }
 681
 682         inst->qlen++;
 683
 684         __build_packet_message(inst, skb, data_len, pf,
 685                                 hooknum, in, out, prefix, plen);
 686
 687         if (inst->qlen >= qthreshold)
 688                 __nfulnl_flush(inst);
 689         /* timer_pending always called within inst->lock, so there
 690          * is no chance of a race here */
 691         else if (!timer_pending(&inst->timer)) {
 692                 instance_get(inst);
 693                 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
 694                 add_timer(&inst->timer);
 695         }
 696
 697 unlock_and_release:
 698         spin_unlock_bh(&inst->lock);
 699         instance_put(inst);
 700         return;
 701
 702 alloc_failure:
 703         /* FIXME: statistics */
 704         goto unlock_and_release;
 705 }
 706 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
 707
 708 static int
 709 nfulnl_rcv_nl_event(struct notifier_block *this,
 710                    unsigned long event, void *ptr)
 711 {
 712         struct netlink_notify *n = ptr;
 713
 714         if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
 715                 int i;
 716
 717                 /* destroy all instances for this portid */
 718                 spin_lock_bh(&instances_lock);
 719                 for  (i = 0; i < INSTANCE_BUCKETS; i++) {
 720                         struct hlist_node *tmp, *t2;
 721                         struct nfulnl_instance *inst;
 722                         struct hlist_head *head = &instance_table[i];
 723
 724                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
 725                                 if ((net_eq(n->net, &init_net)) &&
 726                                     (n->portid == inst->peer_portid))
 727                                         __instance_destroy(inst);
 728                         }
 729                 }
 730                 spin_unlock_bh(&instances_lock);
 731         }
 732         return NOTIFY_DONE;
 733 }
 734
 735 static struct notifier_block nfulnl_rtnl_notifier = {
 736         .notifier_call  = nfulnl_rcv_nl_event,
 737 };
 738
 739 static int
 740 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
 741                    const struct nlmsghdr *nlh,
 742                    const struct nlattr * const nfqa[])
 743 {
 744         return -ENOTSUPP;
 745 }
 746
 747 static struct nf_logger nfulnl_logger __read_mostly = {
 748         .name   = "nfnetlink_log",
 749         .logfn  = &nfulnl_log_packet,
 750         .me     = THIS_MODULE,
 751 };
 752
 753 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
 754         [NFULA_CFG_CMD]         = { .len = sizeof(struct nfulnl_msg_config_cmd) },
 755         [NFULA_CFG_MODE]        = { .len = sizeof(struct nfulnl_msg_config_mode) },
 756         [NFULA_CFG_TIMEOUT]     = { .type = NLA_U32 },
 757         [NFULA_CFG_QTHRESH]     = { .type = NLA_U32 },
 758         [NFULA_CFG_NLBUFSIZ]    = { .type = NLA_U32 },
 759         [NFULA_CFG_FLAGS]       = { .type = NLA_U16 },
 760 };
 761
 762 static int
 763 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 764                    const struct nlmsghdr *nlh,
 765                    const struct nlattr * const nfula[])
 766 {
 767         struct nfgenmsg *nfmsg = nlmsg_data(nlh);
 768         u_int16_t group_num = ntohs(nfmsg->res_id);
 769         struct nfulnl_instance *inst;
 770         struct nfulnl_msg_config_cmd *cmd = NULL;
 771         int ret = 0;
 772
 773         if (nfula[NFULA_CFG_CMD]) {
 774                 u_int8_t pf = nfmsg->nfgen_family;
 775                 cmd = nla_data(nfula[NFULA_CFG_CMD]);
 776
 777                 /* Commands without queue context */
 778                 switch (cmd->command) {
 779                 case NFULNL_CFG_CMD_PF_BIND:
 780                         return nf_log_bind_pf(pf, &nfulnl_logger);
 781                 case NFULNL_CFG_CMD_PF_UNBIND:
 782                         nf_log_unbind_pf(pf);
 783                         return 0;
 784                 }
 785         }
 786
 787         inst = instance_lookup_get(group_num);
 788         if (inst && inst->peer_portid != NETLINK_CB(skb).portid) {
 789                 ret = -EPERM;
 790                 goto out_put;
 791         }
 792
 793         if (cmd != NULL) {
 794                 switch (cmd->command) {
 795                 case NFULNL_CFG_CMD_BIND:
 796                         if (inst) {
 797                                 ret = -EBUSY;
 798                                 goto out_put;
 799                         }
 800
 801                         inst = instance_create(group_num,
 802                                                NETLINK_CB(skb).portid,
 803                                                sk_user_ns(NETLINK_CB(skb).ssk));
 804                         if (IS_ERR(inst)) {
 805                                 ret = PTR_ERR(inst);
 806                                 goto out;
 807                         }
 808                         break;
 809                 case NFULNL_CFG_CMD_UNBIND:
 810                         if (!inst) {
 811                                 ret = -ENODEV;
 812                                 goto out;
 813                         }
 814
 815                         instance_destroy(inst);
 816                         goto out_put;
 817                 default:
 818                         ret = -ENOTSUPP;
 819                         break;
 820                 }
 821         }
 822
 823         if (nfula[NFULA_CFG_MODE]) {
 824                 struct nfulnl_msg_config_mode *params;
 825                 params = nla_data(nfula[NFULA_CFG_MODE]);
 826
 827                 if (!inst) {
 828                         ret = -ENODEV;
 829                         goto out;
 830                 }
 831                 nfulnl_set_mode(inst, params->copy_mode,
 832                                 ntohl(params->copy_range));
 833         }
 834
 835         if (nfula[NFULA_CFG_TIMEOUT]) {
 836                 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
 837
 838                 if (!inst) {
 839                         ret = -ENODEV;
 840                         goto out;
 841                 }
 842                 nfulnl_set_timeout(inst, ntohl(timeout));
 843         }
 844
 845         if (nfula[NFULA_CFG_NLBUFSIZ]) {
 846                 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
 847
 848                 if (!inst) {
 849                         ret = -ENODEV;
 850                         goto out;
 851                 }
 852                 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
 853         }
 854
 855         if (nfula[NFULA_CFG_QTHRESH]) {
 856                 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
 857
 858                 if (!inst) {
 859                         ret = -ENODEV;
 860                         goto out;
 861                 }
 862                 nfulnl_set_qthresh(inst, ntohl(qthresh));
 863         }
 864
 865         if (nfula[NFULA_CFG_FLAGS]) {
 866                 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
 867
 868                 if (!inst) {
 869                         ret = -ENODEV;
 870                         goto out;
 871                 }
 872                 nfulnl_set_flags(inst, ntohs(flags));
 873         }
 874
 875 out_put:
 876         instance_put(inst);
 877 out:
 878         return ret;
 879 }
 880
 881 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
 882         [NFULNL_MSG_PACKET]     = { .call = nfulnl_recv_unsupp,
 883                                     .attr_count = NFULA_MAX, },
 884         [NFULNL_MSG_CONFIG]     = { .call = nfulnl_recv_config,
 885                                     .attr_count = NFULA_CFG_MAX,
 886                                     .policy = nfula_cfg_policy },
 887 };
 888
 889 static const struct nfnetlink_subsystem nfulnl_subsys = {
 890         .name           = "log",
 891         .subsys_id      = NFNL_SUBSYS_ULOG,
 892         .cb_count       = NFULNL_MSG_MAX,
 893         .cb             = nfulnl_cb,
 894 };
 895
 896 #ifdef CONFIG_PROC_FS
 897 struct iter_state {
 898         unsigned int bucket;
 899 };
 900
 901 static struct hlist_node *get_first(struct iter_state *st)
 902 {
 903         if (!st)
 904                 return NULL;
 905
 906         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
 907                 if (!hlist_empty(&instance_table[st->bucket]))
 908                         return rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
 909         }
 910         return NULL;
 911 }
 912
 913 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
 914 {
 915         h = rcu_dereference_bh(hlist_next_rcu(h));
 916         while (!h) {
 917                 if (++st->bucket >= INSTANCE_BUCKETS)
 918                         return NULL;
 919
 920                 h = rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
 921         }
 922         return h;
 923 }
 924
 925 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
 926 {
 927         struct hlist_node *head;
 928         head = get_first(st);
 929
 930         if (head)
 931                 while (pos && (head = get_next(st, head)))
 932                         pos--;
 933         return pos ? NULL : head;
 934 }
 935
 936 static void *seq_start(struct seq_file *seq, loff_t *pos)
 937         __acquires(rcu_bh)
 938 {
 939         rcu_read_lock_bh();
 940         return get_idx(seq->private, *pos);
 941 }
 942
 943 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
 944 {
 945         (*pos)++;
 946         return get_next(s->private, v);
 947 }
 948
 949 static void seq_stop(struct seq_file *s, void *v)
 950         __releases(rcu_bh)
 951 {
 952         rcu_read_unlock_bh();
 953 }
 954
 955 static int seq_show(struct seq_file *s, void *v)
 956 {
 957         const struct nfulnl_instance *inst = v;
 958
 959         return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
 960                           inst->group_num,
 961                           inst->peer_portid, inst->qlen,
 962                           inst->copy_mode, inst->copy_range,
 963                           inst->flushtimeout, atomic_read(&inst->use));
 964 }
 965
 966 static const struct seq_operations nful_seq_ops = {
 967         .start  = seq_start,
 968         .next   = seq_next,
 969         .stop   = seq_stop,
 970         .show   = seq_show,
 971 };
 972
 973 static int nful_open(struct inode *inode, struct file *file)
 974 {
 975         return seq_open_private(file, &nful_seq_ops,
 976                         sizeof(struct iter_state));
 977 }
 978
 979 static const struct file_operations nful_file_ops = {
 980         .owner   = THIS_MODULE,
 981         .open    = nful_open,
 982         .read    = seq_read,
 983         .llseek  = seq_lseek,
 984         .release = seq_release_private,
 985 };
 986
 987 #endif /* PROC_FS */
 988
 989 static int __init nfnetlink_log_init(void)
 990 {
 991         int i, status = -ENOMEM;
 992
 993         for (i = 0; i < INSTANCE_BUCKETS; i++)
 994                 INIT_HLIST_HEAD(&instance_table[i]);
 995
 996         /* it's not really all that important to have a random value, so
 997          * we can do this from the init function, even if there hasn't
 998          * been that much entropy yet */
 999         get_random_bytes(&hash_init, sizeof(hash_init));
1000
1001         netlink_register_notifier(&nfulnl_rtnl_notifier);
1002         status = nfnetlink_subsys_register(&nfulnl_subsys);
1003         if (status < 0) {
1004                 printk(KERN_ERR "log: failed to create netlink socket\n");
1005                 goto cleanup_netlink_notifier;
1006         }
1007
1008         status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
1009         if (status < 0) {
1010                 printk(KERN_ERR "log: failed to register logger\n");
1011                 goto cleanup_subsys;
1012         }
1013
1014 #ifdef CONFIG_PROC_FS
1015         if (!proc_create("nfnetlink_log", 0440,
1016                          proc_net_netfilter, &nful_file_ops)) {
1017                 status = -ENOMEM;
1018                 goto cleanup_logger;
1019         }
1020 #endif
1021         return status;
1022
1023 #ifdef CONFIG_PROC_FS
1024 cleanup_logger:
1025         nf_log_unregister(&nfulnl_logger);
1026 #endif
1027 cleanup_subsys:
1028         nfnetlink_subsys_unregister(&nfulnl_subsys);
1029 cleanup_netlink_notifier:
1030         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1031         return status;
1032 }
1033
1034 static void __exit nfnetlink_log_fini(void)
1035 {
1036         nf_log_unregister(&nfulnl_logger);
1037 #ifdef CONFIG_PROC_FS
1038         remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1039 #endif
1040         nfnetlink_subsys_unregister(&nfulnl_subsys);
1041         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1042 }
1043
1044 MODULE_DESCRIPTION("netfilter userspace logging");
1045 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1046 MODULE_LICENSE("GPL");
1047 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1048
1049 module_init(nfnetlink_log_init);
1050 module_exit(nfnetlink_log_fini);