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