SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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/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 <net/sock.h>
  32
  33 #include <asm/atomic.h>
  34
  35 #ifdef CONFIG_BRIDGE_NETFILTER
  36 #include "../bridge/br_private.h"
  37 #endif
  38
  39 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
  40 #define NFULNL_TIMEOUT_DEFAULT  100     /* every second */
  41 #define NFULNL_QTHRESH_DEFAULT  100     /* 100 packets */
  42
  43 #define PRINTR(x, args...)      do { if (net_ratelimit()) \
  44                                      printk(x, ## args); } while (0);
  45
  46 #if 0
  47 #define UDEBUG(x, args ...)     printk(KERN_DEBUG "%s(%d):%s(): " x,       \
  48                                         __FILE__, __LINE__, __FUNCTION__,  \
  49                                         ## args)
  50 #else
  51 #define UDEBUG(x, ...)
  52 #endif
  53
  54 struct nfulnl_instance {
  55         struct hlist_node hlist;        /* global list of instances */
  56         spinlock_t lock;
  57         atomic_t use;                   /* use count */
  58
  59         unsigned int qlen;              /* number of nlmsgs in skb */
  60         struct sk_buff *skb;            /* pre-allocatd skb */
  61         struct nlmsghdr *lastnlh;       /* netlink header of last msg in skb */
  62         struct timer_list timer;
  63         int peer_pid;                   /* PID of the peer process */
  64
  65         /* configurable parameters */
  66         unsigned int flushtimeout;      /* timeout until queue flush */
  67         unsigned int nlbufsiz;          /* netlink buffer allocation size */
  68         unsigned int qthreshold;        /* threshold of the queue */
  69         u_int32_t copy_range;
  70         u_int32_t seq;                  /* instance-local sequential counter */
  71         u_int16_t group_num;            /* number of this queue */
  72         u_int16_t flags;
  73         u_int8_t copy_mode;
  74 };
  75
  76 static DEFINE_RWLOCK(instances_lock);
  77 static atomic_t global_seq;
  78
  79 #define INSTANCE_BUCKETS        16
  80 static struct hlist_head instance_table[INSTANCE_BUCKETS];
  81 static unsigned int hash_init;
  82
  83 static inline u_int8_t instance_hashfn(u_int16_t group_num)
  84 {
  85         return ((group_num & 0xff) % INSTANCE_BUCKETS);
  86 }
  87
  88 static struct nfulnl_instance *
  89 __instance_lookup(u_int16_t group_num)
  90 {
  91         struct hlist_head *head;
  92         struct hlist_node *pos;
  93         struct nfulnl_instance *inst;
  94
  95         UDEBUG("entering (group_num=%u)\n", group_num);
  96
  97         head = &instance_table[instance_hashfn(group_num)];
  98         hlist_for_each_entry(inst, pos, head, hlist) {
  99                 if (inst->group_num == group_num)
 100                         return inst;
 101         }
 102         return NULL;
 103 }
 104
 105 static inline void
 106 instance_get(struct nfulnl_instance *inst)
 107 {
 108         atomic_inc(&inst->use);
 109 }
 110
 111 static struct nfulnl_instance *
 112 instance_lookup_get(u_int16_t group_num)
 113 {
 114         struct nfulnl_instance *inst;
 115
 116         read_lock_bh(&instances_lock);
 117         inst = __instance_lookup(group_num);
 118         if (inst)
 119                 instance_get(inst);
 120         read_unlock_bh(&instances_lock);
 121
 122         return inst;
 123 }
 124
 125 static void
 126 instance_put(struct nfulnl_instance *inst)
 127 {
 128         if (inst && atomic_dec_and_test(&inst->use)) {
 129                 UDEBUG("kfree(inst=%p)\n", inst);
 130                 kfree(inst);
 131                 module_put(THIS_MODULE);
 132         }
 133 }
 134
 135 static void nfulnl_timer(unsigned long data);
 136
 137 static struct nfulnl_instance *
 138 instance_create(u_int16_t group_num, int pid)
 139 {
 140         struct nfulnl_instance *inst;
 141
 142         UDEBUG("entering (group_num=%u, pid=%d)\n", group_num,
 143                 pid);
 144
 145         write_lock_bh(&instances_lock);
 146         if (__instance_lookup(group_num)) {
 147                 inst = NULL;
 148                 UDEBUG("aborting, instance already exists\n");
 149                 goto out_unlock;
 150         }
 151
 152         inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
 153         if (!inst)
 154                 goto out_unlock;
 155
 156         INIT_HLIST_NODE(&inst->hlist);
 157         spin_lock_init(&inst->lock);
 158         /* needs to be two, since we _put() after creation */
 159         atomic_set(&inst->use, 2);
 160
 161         init_timer(&inst->timer);
 162         inst->timer.function = nfulnl_timer;
 163         inst->timer.data = (unsigned long)inst;
 164         /* don't start timer yet. (re)start it  with every packet */
 165
 166         inst->peer_pid = pid;
 167         inst->group_num = group_num;
 168
 169         inst->qthreshold        = NFULNL_QTHRESH_DEFAULT;
 170         inst->flushtimeout      = NFULNL_TIMEOUT_DEFAULT;
 171         inst->nlbufsiz          = NFULNL_NLBUFSIZ_DEFAULT;
 172         inst->copy_mode         = NFULNL_COPY_PACKET;
 173         inst->copy_range        = 0xffff;
 174
 175         if (!try_module_get(THIS_MODULE))
 176                 goto out_free;
 177
 178         hlist_add_head(&inst->hlist,
 179                        &instance_table[instance_hashfn(group_num)]);
 180
 181         UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
 182                 inst->hlist.next);
 183
 184         write_unlock_bh(&instances_lock);
 185
 186         return inst;
 187
 188 out_free:
 189         instance_put(inst);
 190 out_unlock:
 191         write_unlock_bh(&instances_lock);
 192         return NULL;
 193 }
 194
 195 static int __nfulnl_send(struct nfulnl_instance *inst);
 196
 197 static void
 198 _instance_destroy2(struct nfulnl_instance *inst, int lock)
 199 {
 200         /* first pull it out of the global list */
 201         if (lock)
 202                 write_lock_bh(&instances_lock);
 203
 204         UDEBUG("removing instance %p (queuenum=%u) from hash\n",
 205                 inst, inst->group_num);
 206
 207         hlist_del(&inst->hlist);
 208
 209         if (lock)
 210                 write_unlock_bh(&instances_lock);
 211
 212         /* then flush all pending packets from skb */
 213
 214         spin_lock_bh(&inst->lock);
 215         if (inst->skb) {
 216                 /* timer "holds" one reference (we have one more) */
 217                 if (del_timer(&inst->timer))
 218                         instance_put(inst);
 219                 if (inst->qlen)
 220                         __nfulnl_send(inst);
 221                 if (inst->skb) {
 222                         kfree_skb(inst->skb);
 223                         inst->skb = NULL;
 224                 }
 225         }
 226         spin_unlock_bh(&inst->lock);
 227
 228         /* and finally put the refcount */
 229         instance_put(inst);
 230 }
 231
 232 static inline void
 233 __instance_destroy(struct nfulnl_instance *inst)
 234 {
 235         _instance_destroy2(inst, 0);
 236 }
 237
 238 static inline void
 239 instance_destroy(struct nfulnl_instance *inst)
 240 {
 241         _instance_destroy2(inst, 1);
 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                 /* we're using struct nfattr which has 16bit nfa_len */
 262                 if (range > 0xffff)
 263                         inst->copy_range = 0xffff;
 264                 else
 265                         inst->copy_range = range;
 266                 break;
 267
 268         default:
 269                 status = -EINVAL;
 270                 break;
 271         }
 272
 273         spin_unlock_bh(&inst->lock);
 274
 275         return status;
 276 }
 277
 278 static int
 279 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
 280 {
 281         int status;
 282
 283         spin_lock_bh(&inst->lock);
 284         if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
 285                 status = -ERANGE;
 286         else if (nlbufsiz > 131072)
 287                 status = -ERANGE;
 288         else {
 289                 inst->nlbufsiz = nlbufsiz;
 290                 status = 0;
 291         }
 292         spin_unlock_bh(&inst->lock);
 293
 294         return status;
 295 }
 296
 297 static int
 298 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
 299 {
 300         spin_lock_bh(&inst->lock);
 301         inst->flushtimeout = timeout;
 302         spin_unlock_bh(&inst->lock);
 303
 304         return 0;
 305 }
 306
 307 static int
 308 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
 309 {
 310         spin_lock_bh(&inst->lock);
 311         inst->qthreshold = qthresh;
 312         spin_unlock_bh(&inst->lock);
 313
 314         return 0;
 315 }
 316
 317 static int
 318 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
 319 {
 320         spin_lock_bh(&inst->lock);
 321         inst->flags = flags;
 322         spin_unlock_bh(&inst->lock);
 323
 324         return 0;
 325 }
 326
 327 static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size,
 328                                         unsigned int pkt_size)
 329 {
 330         struct sk_buff *skb;
 331         unsigned int n;
 332
 333         UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
 334
 335         /* alloc skb which should be big enough for a whole multipart
 336          * message.  WARNING: has to be <= 128k due to slab restrictions */
 337
 338         n = max(inst_size, pkt_size);
 339         skb = alloc_skb(n, GFP_ATOMIC);
 340         if (!skb) {
 341                 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
 342                         inst_size);
 343
 344                 if (n > pkt_size) {
 345                         /* try to allocate only as much as we need for current
 346                          * packet */
 347
 348                         skb = alloc_skb(pkt_size, GFP_ATOMIC);
 349                         if (!skb)
 350                                 PRINTR("nfnetlink_log: can't even alloc %u "
 351                                        "bytes\n", pkt_size);
 352                 }
 353         }
 354
 355         return skb;
 356 }
 357
 358 static int
 359 __nfulnl_send(struct nfulnl_instance *inst)
 360 {
 361         int status;
 362
 363         if (!inst->skb)
 364                 return 0;
 365
 366         if (inst->qlen > 1)
 367                 inst->lastnlh->nlmsg_type = NLMSG_DONE;
 368
 369         status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
 370         if (status < 0) {
 371                 UDEBUG("netlink_unicast() failed\n");
 372                 /* FIXME: statistics */
 373         }
 374
 375         inst->qlen = 0;
 376         inst->skb = NULL;
 377         inst->lastnlh = NULL;
 378
 379         return status;
 380 }
 381
 382 static void nfulnl_timer(unsigned long data)
 383 {
 384         struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
 385
 386         UDEBUG("timer function called, flushing buffer\n");
 387
 388         spin_lock_bh(&inst->lock);
 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 nfulnl_instance *inst,
 398                         const struct sk_buff *skb,
 399                         unsigned int data_len,
 400                         unsigned int pf,
 401                         unsigned int hooknum,
 402                         const struct net_device *indev,
 403                         const struct net_device *outdev,
 404                         const struct nf_loginfo *li,
 405                         const char *prefix, unsigned int plen)
 406 {
 407         struct nfulnl_msg_packet_hdr pmsg;
 408         struct nlmsghdr *nlh;
 409         struct nfgenmsg *nfmsg;
 410         __be32 tmp_uint;
 411         sk_buff_data_t old_tail = inst->skb->tail;
 412
 413         UDEBUG("entered\n");
 414
 415         nlh = NLMSG_PUT(inst->skb, 0, 0,
 416                         NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
 417                         sizeof(struct nfgenmsg));
 418         nfmsg = NLMSG_DATA(nlh);
 419         nfmsg->nfgen_family = pf;
 420         nfmsg->version = NFNETLINK_V0;
 421         nfmsg->res_id = htons(inst->group_num);
 422
 423         pmsg.hw_protocol        = skb->protocol;
 424         pmsg.hook               = hooknum;
 425
 426         NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
 427
 428         if (prefix)
 429                 NFA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
 430
 431         if (indev) {
 432                 tmp_uint = htonl(indev->ifindex);
 433 #ifndef CONFIG_BRIDGE_NETFILTER
 434                 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
 435                         &tmp_uint);
 436 #else
 437                 if (pf == PF_BRIDGE) {
 438                         /* Case 1: outdev is physical input device, we need to
 439                          * look for bridge group (when called from
 440                          * netfilter_bridge) */
 441                         NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
 442                                 sizeof(tmp_uint), &tmp_uint);
 443                         /* this is the bridge group "brX" */
 444                         tmp_uint = htonl(indev->br_port->br->dev->ifindex);
 445                         NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
 446                                 sizeof(tmp_uint), &tmp_uint);
 447                 } else {
 448                         /* Case 2: indev is bridge group, we need to look for
 449                          * physical device (when called from ipv4) */
 450                         NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
 451                                 sizeof(tmp_uint), &tmp_uint);
 452                         if (skb->nf_bridge && skb->nf_bridge->physindev) {
 453                                 tmp_uint =
 454                                     htonl(skb->nf_bridge->physindev->ifindex);
 455                                 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
 456                                         sizeof(tmp_uint), &tmp_uint);
 457                         }
 458                 }
 459 #endif
 460         }
 461
 462         if (outdev) {
 463                 tmp_uint = htonl(outdev->ifindex);
 464 #ifndef CONFIG_BRIDGE_NETFILTER
 465                 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
 466                         &tmp_uint);
 467 #else
 468                 if (pf == PF_BRIDGE) {
 469                         /* Case 1: outdev is physical output device, we need to
 470                          * look for bridge group (when called from
 471                          * netfilter_bridge) */
 472                         NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
 473                                 sizeof(tmp_uint), &tmp_uint);
 474                         /* this is the bridge group "brX" */
 475                         tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
 476                         NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
 477                                 sizeof(tmp_uint), &tmp_uint);
 478                 } else {
 479                         /* Case 2: indev is a bridge group, we need to look
 480                          * for physical device (when called from ipv4) */
 481                         NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
 482                                 sizeof(tmp_uint), &tmp_uint);
 483                         if (skb->nf_bridge && skb->nf_bridge->physoutdev) {
 484                                 tmp_uint =
 485                                     htonl(skb->nf_bridge->physoutdev->ifindex);
 486                                 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
 487                                         sizeof(tmp_uint), &tmp_uint);
 488                         }
 489                 }
 490 #endif
 491         }
 492
 493         if (skb->mark) {
 494                 tmp_uint = htonl(skb->mark);
 495                 NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
 496         }
 497
 498         if (indev && skb->dev && skb->dev->hard_header_parse) {
 499                 struct nfulnl_msg_packet_hw phw;
 500                 int len = skb->dev->hard_header_parse((struct sk_buff *)skb,
 501                                                     phw.hw_addr);
 502                 phw.hw_addrlen = htons(len);
 503                 NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
 504         }
 505
 506         if (skb->tstamp.tv64) {
 507                 struct nfulnl_msg_packet_timestamp ts;
 508                 struct timeval tv = ktime_to_timeval(skb->tstamp);
 509                 ts.sec = cpu_to_be64(tv.tv_sec);
 510                 ts.usec = cpu_to_be64(tv.tv_usec);
 511
 512                 NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
 513         }
 514
 515         /* UID */
 516         if (skb->sk) {
 517                 read_lock_bh(&skb->sk->sk_callback_lock);
 518                 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
 519                         __be32 uid = htonl(skb->sk->sk_socket->file->f_uid);
 520                         /* need to unlock here since NFA_PUT may goto */
 521                         read_unlock_bh(&skb->sk->sk_callback_lock);
 522                         NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
 523                 } else
 524                         read_unlock_bh(&skb->sk->sk_callback_lock);
 525         }
 526
 527         /* local sequence number */
 528         if (inst->flags & NFULNL_CFG_F_SEQ) {
 529                 tmp_uint = htonl(inst->seq++);
 530                 NFA_PUT(inst->skb, NFULA_SEQ, sizeof(tmp_uint), &tmp_uint);
 531         }
 532         /* global sequence number */
 533         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) {
 534                 tmp_uint = htonl(atomic_inc_return(&global_seq));
 535                 NFA_PUT(inst->skb, NFULA_SEQ_GLOBAL, sizeof(tmp_uint), &tmp_uint);
 536         }
 537
 538         if (data_len) {
 539                 struct nfattr *nfa;
 540                 int size = NFA_LENGTH(data_len);
 541
 542                 if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) {
 543                         printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
 544                         goto nlmsg_failure;
 545                 }
 546
 547                 nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size));
 548                 nfa->nfa_type = NFULA_PAYLOAD;
 549                 nfa->nfa_len = size;
 550
 551                 if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len))
 552                         BUG();
 553         }
 554
 555         nlh->nlmsg_len = inst->skb->tail - old_tail;
 556         inst->lastnlh = nlh;
 557         return 0;
 558
 559 nlmsg_failure:
 560         UDEBUG("nlmsg_failure\n");
 561 nfattr_failure:
 562         PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
 563         return -1;
 564 }
 565
 566 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 567
 568 static struct nf_loginfo default_loginfo = {
 569         .type =         NF_LOG_TYPE_ULOG,
 570         .u = {
 571                 .ulog = {
 572                         .copy_len       = 0xffff,
 573                         .group          = 0,
 574                         .qthreshold     = 1,
 575                 },
 576         },
 577 };
 578
 579 /* log handler for internal netfilter logging api */
 580 static void
 581 nfulnl_log_packet(unsigned int pf,
 582                   unsigned int hooknum,
 583                   const struct sk_buff *skb,
 584                   const struct net_device *in,
 585                   const struct net_device *out,
 586                   const struct nf_loginfo *li_user,
 587                   const char *prefix)
 588 {
 589         unsigned int size, data_len;
 590         struct nfulnl_instance *inst;
 591         const struct nf_loginfo *li;
 592         unsigned int qthreshold;
 593         unsigned int plen;
 594
 595         if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
 596                 li = li_user;
 597         else
 598                 li = &default_loginfo;
 599
 600         inst = instance_lookup_get(li->u.ulog.group);
 601         if (!inst)
 602                 inst = instance_lookup_get(0);
 603         if (!inst) {
 604                 PRINTR("nfnetlink_log: trying to log packet, "
 605                         "but no instance for group %u\n", li->u.ulog.group);
 606                 return;
 607         }
 608
 609         plen = 0;
 610         if (prefix)
 611                 plen = strlen(prefix) + 1;
 612
 613         /* all macros expand to constant values at compile time */
 614         /* FIXME: do we want to make the size calculation conditional based on
 615          * what is actually present?  way more branches and checks, but more
 616          * memory efficient... */
 617         size =    NLMSG_SPACE(sizeof(struct nfgenmsg))
 618                 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr))
 619                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
 620                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
 621 #ifdef CONFIG_BRIDGE_NETFILTER
 622                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
 623                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
 624 #endif
 625                 + NFA_SPACE(sizeof(u_int32_t))  /* mark */
 626                 + NFA_SPACE(sizeof(u_int32_t))  /* uid */
 627                 + NFA_SPACE(plen)               /* prefix */
 628                 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw))
 629                 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp));
 630
 631         UDEBUG("initial size=%u\n", size);
 632
 633         spin_lock_bh(&inst->lock);
 634
 635         if (inst->flags & NFULNL_CFG_F_SEQ)
 636                 size += NFA_SPACE(sizeof(u_int32_t));
 637         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
 638                 size += NFA_SPACE(sizeof(u_int32_t));
 639
 640         qthreshold = inst->qthreshold;
 641         /* per-rule qthreshold overrides per-instance */
 642         if (qthreshold > li->u.ulog.qthreshold)
 643                 qthreshold = li->u.ulog.qthreshold;
 644
 645         switch (inst->copy_mode) {
 646         case NFULNL_COPY_META:
 647         case NFULNL_COPY_NONE:
 648                 data_len = 0;
 649                 break;
 650
 651         case NFULNL_COPY_PACKET:
 652                 if (inst->copy_range == 0
 653                     || inst->copy_range > skb->len)
 654                         data_len = skb->len;
 655                 else
 656                         data_len = inst->copy_range;
 657
 658                 size += NFA_SPACE(data_len);
 659                 UDEBUG("copy_packet, therefore size now %u\n", size);
 660                 break;
 661
 662         default:
 663                 goto unlock_and_release;
 664         }
 665
 666         if (inst->qlen >= qthreshold ||
 667             (inst->skb && size > skb_tailroom(inst->skb))) {
 668                 /* either the queue len is too high or we don't have
 669                  * enough room in the skb left. flush to userspace. */
 670                 UDEBUG("flushing old skb\n");
 671
 672                 /* timer "holds" one reference (we have another one) */
 673                 if (del_timer(&inst->timer))
 674                         instance_put(inst);
 675                 __nfulnl_send(inst);
 676         }
 677
 678         if (!inst->skb) {
 679                 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
 680                 if (!inst->skb)
 681                         goto alloc_failure;
 682         }
 683
 684         UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
 685         inst->qlen++;
 686
 687         __build_packet_message(inst, skb, data_len, pf,
 688                                 hooknum, in, out, li, prefix, plen);
 689
 690         /* timer_pending always called within inst->lock, so there
 691          * is no chance of a race here */
 692         if (!timer_pending(&inst->timer)) {
 693                 instance_get(inst);
 694                 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
 695                 add_timer(&inst->timer);
 696         }
 697
 698 unlock_and_release:
 699         spin_unlock_bh(&inst->lock);
 700         instance_put(inst);
 701         return;
 702
 703 alloc_failure:
 704         UDEBUG("error allocating skb\n");
 705         /* FIXME: statistics */
 706         goto unlock_and_release;
 707 }
 708
 709 static int
 710 nfulnl_rcv_nl_event(struct notifier_block *this,
 711                    unsigned long event, void *ptr)
 712 {
 713         struct netlink_notify *n = ptr;
 714
 715         if (event == NETLINK_URELEASE &&
 716             n->protocol == NETLINK_NETFILTER && n->pid) {
 717                 int i;
 718
 719                 /* destroy all instances for this pid */
 720                 write_lock_bh(&instances_lock);
 721                 for  (i = 0; i < INSTANCE_BUCKETS; i++) {
 722                         struct hlist_node *tmp, *t2;
 723                         struct nfulnl_instance *inst;
 724                         struct hlist_head *head = &instance_table[i];
 725
 726                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
 727                                 UDEBUG("node = %p\n", inst);
 728                                 if (n->pid == inst->peer_pid)
 729                                         __instance_destroy(inst);
 730                         }
 731                 }
 732                 write_unlock_bh(&instances_lock);
 733         }
 734         return NOTIFY_DONE;
 735 }
 736
 737 static struct notifier_block nfulnl_rtnl_notifier = {
 738         .notifier_call  = nfulnl_rcv_nl_event,
 739 };
 740
 741 static int
 742 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
 743                   struct nlmsghdr *nlh, struct nfattr *nfqa[])
 744 {
 745         return -ENOTSUPP;
 746 }
 747
 748 static struct nf_logger nfulnl_logger = {
 749         .name   = "nfnetlink_log",
 750         .logfn  = &nfulnl_log_packet,
 751         .me     = THIS_MODULE,
 752 };
 753
 754 static const int nfula_min[NFULA_MAX] = {
 755         [NFULA_PACKET_HDR-1]    = sizeof(struct nfulnl_msg_packet_hdr),
 756         [NFULA_MARK-1]          = sizeof(u_int32_t),
 757         [NFULA_TIMESTAMP-1]     = sizeof(struct nfulnl_msg_packet_timestamp),
 758         [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t),
 759         [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t),
 760         [NFULA_IFINDEX_PHYSINDEV-1]     = sizeof(u_int32_t),
 761         [NFULA_IFINDEX_PHYSOUTDEV-1]    = sizeof(u_int32_t),
 762         [NFULA_HWADDR-1]        = sizeof(struct nfulnl_msg_packet_hw),
 763         [NFULA_PAYLOAD-1]       = 0,
 764         [NFULA_PREFIX-1]        = 0,
 765         [NFULA_UID-1]           = sizeof(u_int32_t),
 766         [NFULA_SEQ-1]           = sizeof(u_int32_t),
 767         [NFULA_SEQ_GLOBAL-1]    = sizeof(u_int32_t),
 768 };
 769
 770 static const int nfula_cfg_min[NFULA_CFG_MAX] = {
 771         [NFULA_CFG_CMD-1]       = sizeof(struct nfulnl_msg_config_cmd),
 772         [NFULA_CFG_MODE-1]      = sizeof(struct nfulnl_msg_config_mode),
 773         [NFULA_CFG_TIMEOUT-1]   = sizeof(u_int32_t),
 774         [NFULA_CFG_QTHRESH-1]   = sizeof(u_int32_t),
 775         [NFULA_CFG_NLBUFSIZ-1]  = sizeof(u_int32_t),
 776         [NFULA_CFG_FLAGS-1]     = sizeof(u_int16_t),
 777 };
 778
 779 static int
 780 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 781                    struct nlmsghdr *nlh, struct nfattr *nfula[])
 782 {
 783         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 784         u_int16_t group_num = ntohs(nfmsg->res_id);
 785         struct nfulnl_instance *inst;
 786         int ret = 0;
 787
 788         UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
 789
 790         if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) {
 791                 UDEBUG("bad attribute size\n");
 792                 return -EINVAL;
 793         }
 794
 795         inst = instance_lookup_get(group_num);
 796         if (nfula[NFULA_CFG_CMD-1]) {
 797                 u_int8_t pf = nfmsg->nfgen_family;
 798                 struct nfulnl_msg_config_cmd *cmd;
 799                 cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]);
 800                 UDEBUG("found CFG_CMD for\n");
 801
 802                 switch (cmd->command) {
 803                 case NFULNL_CFG_CMD_BIND:
 804                         if (inst) {
 805                                 ret = -EBUSY;
 806                                 goto out_put;
 807                         }
 808
 809                         inst = instance_create(group_num,
 810                                                NETLINK_CB(skb).pid);
 811                         if (!inst) {
 812                                 ret = -EINVAL;
 813                                 goto out;
 814                         }
 815                         break;
 816                 case NFULNL_CFG_CMD_UNBIND:
 817                         if (!inst) {
 818                                 ret = -ENODEV;
 819                                 goto out;
 820                         }
 821
 822                         if (inst->peer_pid != NETLINK_CB(skb).pid) {
 823                                 ret = -EPERM;
 824                                 goto out_put;
 825                         }
 826
 827                         instance_destroy(inst);
 828                         break;
 829                 case NFULNL_CFG_CMD_PF_BIND:
 830                         UDEBUG("registering log handler for pf=%u\n", pf);
 831                         ret = nf_log_register(pf, &nfulnl_logger);
 832                         break;
 833                 case NFULNL_CFG_CMD_PF_UNBIND:
 834                         UDEBUG("unregistering log handler for pf=%u\n", pf);
 835                         /* This is a bug and a feature.  We cannot unregister
 836                          * other handlers, like nfnetlink_inst can */
 837                         nf_log_unregister_pf(pf);
 838                         break;
 839                 default:
 840                         ret = -EINVAL;
 841                         break;
 842                 }
 843
 844                 if (!inst)
 845                         goto out;
 846         } else {
 847                 if (!inst) {
 848                         UDEBUG("no config command, and no instance for "
 849                                 "group=%u pid=%u =>ENOENT\n",
 850                                 group_num, NETLINK_CB(skb).pid);
 851                         ret = -ENOENT;
 852                         goto out;
 853                 }
 854
 855                 if (inst->peer_pid != NETLINK_CB(skb).pid) {
 856                         UDEBUG("no config command, and wrong pid\n");
 857                         ret = -EPERM;
 858                         goto out_put;
 859                 }
 860         }
 861
 862         if (nfula[NFULA_CFG_MODE-1]) {
 863                 struct nfulnl_msg_config_mode *params;
 864                 params = NFA_DATA(nfula[NFULA_CFG_MODE-1]);
 865
 866                 nfulnl_set_mode(inst, params->copy_mode,
 867                                 ntohl(params->copy_range));
 868         }
 869
 870         if (nfula[NFULA_CFG_TIMEOUT-1]) {
 871                 __be32 timeout =
 872                         *(__be32 *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]);
 873
 874                 nfulnl_set_timeout(inst, ntohl(timeout));
 875         }
 876
 877         if (nfula[NFULA_CFG_NLBUFSIZ-1]) {
 878                 __be32 nlbufsiz =
 879                         *(__be32 *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]);
 880
 881                 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
 882         }
 883
 884         if (nfula[NFULA_CFG_QTHRESH-1]) {
 885                 __be32 qthresh =
 886                         *(__be32 *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]);
 887
 888                 nfulnl_set_qthresh(inst, ntohl(qthresh));
 889         }
 890
 891         if (nfula[NFULA_CFG_FLAGS-1]) {
 892                 __be16 flags =
 893                         *(__be16 *)NFA_DATA(nfula[NFULA_CFG_FLAGS-1]);
 894                 nfulnl_set_flags(inst, ntohs(flags));
 895         }
 896
 897 out_put:
 898         instance_put(inst);
 899 out:
 900         return ret;
 901 }
 902
 903 static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
 904         [NFULNL_MSG_PACKET]     = { .call = nfulnl_recv_unsupp,
 905                                     .attr_count = NFULA_MAX, },
 906         [NFULNL_MSG_CONFIG]     = { .call = nfulnl_recv_config,
 907                                     .attr_count = NFULA_CFG_MAX, },
 908 };
 909
 910 static struct nfnetlink_subsystem nfulnl_subsys = {
 911         .name           = "log",
 912         .subsys_id      = NFNL_SUBSYS_ULOG,
 913         .cb_count       = NFULNL_MSG_MAX,
 914         .cb             = nfulnl_cb,
 915 };
 916
 917 #ifdef CONFIG_PROC_FS
 918 struct iter_state {
 919         unsigned int bucket;
 920 };
 921
 922 static struct hlist_node *get_first(struct seq_file *seq)
 923 {
 924         struct iter_state *st = seq->private;
 925
 926         if (!st)
 927                 return NULL;
 928
 929         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
 930                 if (!hlist_empty(&instance_table[st->bucket]))
 931                         return instance_table[st->bucket].first;
 932         }
 933         return NULL;
 934 }
 935
 936 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
 937 {
 938         struct iter_state *st = seq->private;
 939
 940         h = h->next;
 941         while (!h) {
 942                 if (++st->bucket >= INSTANCE_BUCKETS)
 943                         return NULL;
 944
 945                 h = instance_table[st->bucket].first;
 946         }
 947         return h;
 948 }
 949
 950 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
 951 {
 952         struct hlist_node *head;
 953         head = get_first(seq);
 954
 955         if (head)
 956                 while (pos && (head = get_next(seq, head)))
 957                         pos--;
 958         return pos ? NULL : head;
 959 }
 960
 961 static void *seq_start(struct seq_file *seq, loff_t *pos)
 962 {
 963         read_lock_bh(&instances_lock);
 964         return get_idx(seq, *pos);
 965 }
 966
 967 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
 968 {
 969         (*pos)++;
 970         return get_next(s, v);
 971 }
 972
 973 static void seq_stop(struct seq_file *s, void *v)
 974 {
 975         read_unlock_bh(&instances_lock);
 976 }
 977
 978 static int seq_show(struct seq_file *s, void *v)
 979 {
 980         const struct nfulnl_instance *inst = v;
 981
 982         return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
 983                           inst->group_num,
 984                           inst->peer_pid, inst->qlen,
 985                           inst->copy_mode, inst->copy_range,
 986                           inst->flushtimeout, atomic_read(&inst->use));
 987 }
 988
 989 static struct seq_operations nful_seq_ops = {
 990         .start  = seq_start,
 991         .next   = seq_next,
 992         .stop   = seq_stop,
 993         .show   = seq_show,
 994 };
 995
 996 static int nful_open(struct inode *inode, struct file *file)
 997 {
 998         struct seq_file *seq;
 999         struct iter_state *is;
1000         int ret;
1001
1002         is = kzalloc(sizeof(*is), GFP_KERNEL);
1003         if (!is)
1004                 return -ENOMEM;
1005         ret = seq_open(file, &nful_seq_ops);
1006         if (ret < 0)
1007                 goto out_free;
1008         seq = file->private_data;
1009         seq->private = is;
1010         return ret;
1011 out_free:
1012         kfree(is);
1013         return ret;
1014 }
1015
1016 static const struct file_operations nful_file_ops = {
1017         .owner   = THIS_MODULE,
1018         .open    = nful_open,
1019         .read    = seq_read,
1020         .llseek  = seq_lseek,
1021         .release = seq_release_private,
1022 };
1023
1024 #endif /* PROC_FS */
1025
1026 static int __init nfnetlink_log_init(void)
1027 {
1028         int i, status = -ENOMEM;
1029 #ifdef CONFIG_PROC_FS
1030         struct proc_dir_entry *proc_nful;
1031 #endif
1032
1033         for (i = 0; i < INSTANCE_BUCKETS; i++)
1034                 INIT_HLIST_HEAD(&instance_table[i]);
1035
1036         /* it's not really all that important to have a random value, so
1037          * we can do this from the init function, even if there hasn't
1038          * been that much entropy yet */
1039         get_random_bytes(&hash_init, sizeof(hash_init));
1040
1041         netlink_register_notifier(&nfulnl_rtnl_notifier);
1042         status = nfnetlink_subsys_register(&nfulnl_subsys);
1043         if (status < 0) {
1044                 printk(KERN_ERR "log: failed to create netlink socket\n");
1045                 goto cleanup_netlink_notifier;
1046         }
1047
1048 #ifdef CONFIG_PROC_FS
1049         proc_nful = create_proc_entry("nfnetlink_log", 0440,
1050                                       proc_net_netfilter);
1051         if (!proc_nful)
1052                 goto cleanup_subsys;
1053         proc_nful->proc_fops = &nful_file_ops;
1054 #endif
1055         return status;
1056
1057 #ifdef CONFIG_PROC_FS
1058 cleanup_subsys:
1059         nfnetlink_subsys_unregister(&nfulnl_subsys);
1060 #endif
1061 cleanup_netlink_notifier:
1062         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1063         return status;
1064 }
1065
1066 static void __exit nfnetlink_log_fini(void)
1067 {
1068         nf_log_unregister(&nfulnl_logger);
1069 #ifdef CONFIG_PROC_FS
1070         remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1071 #endif
1072         nfnetlink_subsys_unregister(&nfulnl_subsys);
1073         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1074 }
1075
1076 MODULE_DESCRIPTION("netfilter userspace logging");
1077 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1078 MODULE_LICENSE("GPL");
1079 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1080
1081 module_init(nfnetlink_log_init);
1082 module_exit(nfnetlink_log_fini);