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