err.no Git - linux-2.6/blob - net/ipv4/netfilter/nf_nat_core.c

   1 /* NAT for netfilter; shared with compatibility layer. */
   2
   3 /* (C) 1999-2001 Paul `Rusty' Russell
   4  * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/types.h>
  13 #include <linux/timer.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/vmalloc.h>
  16 #include <net/checksum.h>
  17 #include <net/icmp.h>
  18 #include <net/ip.h>
  19 #include <net/tcp.h>  /* For tcp_prot in getorigdst */
  20 #include <linux/icmp.h>
  21 #include <linux/udp.h>
  22 #include <linux/jhash.h>
  23
  24 #include <linux/netfilter_ipv4.h>
  25 #include <net/netfilter/nf_conntrack.h>
  26 #include <net/netfilter/nf_conntrack_core.h>
  27 #include <net/netfilter/nf_nat.h>
  28 #include <net/netfilter/nf_nat_protocol.h>
  29 #include <net/netfilter/nf_nat_core.h>
  30 #include <net/netfilter/nf_nat_helper.h>
  31 #include <net/netfilter/nf_conntrack_helper.h>
  32 #include <net/netfilter/nf_conntrack_l3proto.h>
  33 #include <net/netfilter/nf_conntrack_l4proto.h>
  34
  35 #if 0
  36 #define DEBUGP printk
  37 #else
  38 #define DEBUGP(format, args...)
  39 #endif
  40
  41 static DEFINE_RWLOCK(nf_nat_lock);
  42
  43 static struct nf_conntrack_l3proto *l3proto = NULL;
  44
  45 /* Calculated at init based on memory size */
  46 static unsigned int nf_nat_htable_size;
  47
  48 static struct list_head *bysource;
  49
  50 #define MAX_IP_NAT_PROTO 256
  51 static struct nf_nat_protocol *nf_nat_protos[MAX_IP_NAT_PROTO];
  52
  53 static inline struct nf_nat_protocol *
  54 __nf_nat_proto_find(u_int8_t protonum)
  55 {
  56         return rcu_dereference(nf_nat_protos[protonum]);
  57 }
  58
  59 struct nf_nat_protocol *
  60 nf_nat_proto_find_get(u_int8_t protonum)
  61 {
  62         struct nf_nat_protocol *p;
  63
  64         rcu_read_lock();
  65         p = __nf_nat_proto_find(protonum);
  66         if (!try_module_get(p->me))
  67                 p = &nf_nat_unknown_protocol;
  68         rcu_read_unlock();
  69
  70         return p;
  71 }
  72 EXPORT_SYMBOL_GPL(nf_nat_proto_find_get);
  73
  74 void
  75 nf_nat_proto_put(struct nf_nat_protocol *p)
  76 {
  77         module_put(p->me);
  78 }
  79 EXPORT_SYMBOL_GPL(nf_nat_proto_put);
  80
  81 /* We keep an extra hash for each conntrack, for fast searching. */
  82 static inline unsigned int
  83 hash_by_src(const struct nf_conntrack_tuple *tuple)
  84 {
  85         /* Original src, to ensure we map it consistently if poss. */
  86         return jhash_3words((__force u32)tuple->src.u3.ip, tuple->src.u.all,
  87                             tuple->dst.protonum, 0) % nf_nat_htable_size;
  88 }
  89
  90 /* Noone using conntrack by the time this called. */
  91 static void nf_nat_cleanup_conntrack(struct nf_conn *conn)
  92 {
  93         struct nf_conn_nat *nat;
  94         if (!(conn->status & IPS_NAT_DONE_MASK))
  95                 return;
  96
  97         nat = nfct_nat(conn);
  98         write_lock_bh(&nf_nat_lock);
  99         list_del(&nat->info.bysource);
 100         nat->info.ct = NULL;
 101         write_unlock_bh(&nf_nat_lock);
 102 }
 103
 104 /* Is this tuple already taken? (not by us) */
 105 int
 106 nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
 107                   const struct nf_conn *ignored_conntrack)
 108 {
 109         /* Conntrack tracking doesn't keep track of outgoing tuples; only
 110            incoming ones.  NAT means they don't have a fixed mapping,
 111            so we invert the tuple and look for the incoming reply.
 112
 113            We could keep a separate hash if this proves too slow. */
 114         struct nf_conntrack_tuple reply;
 115
 116         nf_ct_invert_tuplepr(&reply, tuple);
 117         return nf_conntrack_tuple_taken(&reply, ignored_conntrack);
 118 }
 119 EXPORT_SYMBOL(nf_nat_used_tuple);
 120
 121 /* If we source map this tuple so reply looks like reply_tuple, will
 122  * that meet the constraints of range. */
 123 static int
 124 in_range(const struct nf_conntrack_tuple *tuple,
 125          const struct nf_nat_range *range)
 126 {
 127         struct nf_nat_protocol *proto;
 128         int ret = 0;
 129
 130         /* If we are supposed to map IPs, then we must be in the
 131            range specified, otherwise let this drag us onto a new src IP. */
 132         if (range->flags & IP_NAT_RANGE_MAP_IPS) {
 133                 if (ntohl(tuple->src.u3.ip) < ntohl(range->min_ip) ||
 134                     ntohl(tuple->src.u3.ip) > ntohl(range->max_ip))
 135                         return 0;
 136         }
 137
 138         rcu_read_lock();
 139         proto = __nf_nat_proto_find(tuple->dst.protonum);
 140         if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED) ||
 141             proto->in_range(tuple, IP_NAT_MANIP_SRC,
 142                             &range->min, &range->max))
 143                 ret = 1;
 144         rcu_read_unlock();
 145
 146         return ret;
 147 }
 148
 149 static inline int
 150 same_src(const struct nf_conn *ct,
 151          const struct nf_conntrack_tuple *tuple)
 152 {
 153         const struct nf_conntrack_tuple *t;
 154
 155         t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
 156         return (t->dst.protonum == tuple->dst.protonum &&
 157                 t->src.u3.ip == tuple->src.u3.ip &&
 158                 t->src.u.all == tuple->src.u.all);
 159 }
 160
 161 /* Only called for SRC manip */
 162 static int
 163 find_appropriate_src(const struct nf_conntrack_tuple *tuple,
 164                      struct nf_conntrack_tuple *result,
 165                      const struct nf_nat_range *range)
 166 {
 167         unsigned int h = hash_by_src(tuple);
 168         struct nf_conn_nat *nat;
 169         struct nf_conn *ct;
 170
 171         read_lock_bh(&nf_nat_lock);
 172         list_for_each_entry(nat, &bysource[h], info.bysource) {
 173                 ct = nat->info.ct;
 174                 if (same_src(ct, tuple)) {
 175                         /* Copy source part from reply tuple. */
 176                         nf_ct_invert_tuplepr(result,
 177                                        &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 178                         result->dst = tuple->dst;
 179
 180                         if (in_range(result, range)) {
 181                                 read_unlock_bh(&nf_nat_lock);
 182                                 return 1;
 183                         }
 184                 }
 185         }
 186         read_unlock_bh(&nf_nat_lock);
 187         return 0;
 188 }
 189
 190 /* For [FUTURE] fragmentation handling, we want the least-used
 191    src-ip/dst-ip/proto triple.  Fairness doesn't come into it.  Thus
 192    if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
 193    1-65535, we don't do pro-rata allocation based on ports; we choose
 194    the ip with the lowest src-ip/dst-ip/proto usage.
 195 */
 196 static void
 197 find_best_ips_proto(struct nf_conntrack_tuple *tuple,
 198                     const struct nf_nat_range *range,
 199                     const struct nf_conn *ct,
 200                     enum nf_nat_manip_type maniptype)
 201 {
 202         __be32 *var_ipp;
 203         /* Host order */
 204         u_int32_t minip, maxip, j;
 205
 206         /* No IP mapping?  Do nothing. */
 207         if (!(range->flags & IP_NAT_RANGE_MAP_IPS))
 208                 return;
 209
 210         if (maniptype == IP_NAT_MANIP_SRC)
 211                 var_ipp = &tuple->src.u3.ip;
 212         else
 213                 var_ipp = &tuple->dst.u3.ip;
 214
 215         /* Fast path: only one choice. */
 216         if (range->min_ip == range->max_ip) {
 217                 *var_ipp = range->min_ip;
 218                 return;
 219         }
 220
 221         /* Hashing source and destination IPs gives a fairly even
 222          * spread in practice (if there are a small number of IPs
 223          * involved, there usually aren't that many connections
 224          * anyway).  The consistency means that servers see the same
 225          * client coming from the same IP (some Internet Banking sites
 226          * like this), even across reboots. */
 227         minip = ntohl(range->min_ip);
 228         maxip = ntohl(range->max_ip);
 229         j = jhash_2words((__force u32)tuple->src.u3.ip,
 230                          (__force u32)tuple->dst.u3.ip, 0);
 231         *var_ipp = htonl(minip + j % (maxip - minip + 1));
 232 }
 233
 234 /* Manipulate the tuple into the range given.  For NF_IP_POST_ROUTING,
 235  * we change the source to map into the range.  For NF_IP_PRE_ROUTING
 236  * and NF_IP_LOCAL_OUT, we change the destination to map into the
 237  * range.  It might not be possible to get a unique tuple, but we try.
 238  * At worst (or if we race), we will end up with a final duplicate in
 239  * __ip_conntrack_confirm and drop the packet. */
 240 static void
 241 get_unique_tuple(struct nf_conntrack_tuple *tuple,
 242                  const struct nf_conntrack_tuple *orig_tuple,
 243                  const struct nf_nat_range *range,
 244                  struct nf_conn *ct,
 245                  enum nf_nat_manip_type maniptype)
 246 {
 247         struct nf_nat_protocol *proto;
 248
 249         /* 1) If this srcip/proto/src-proto-part is currently mapped,
 250            and that same mapping gives a unique tuple within the given
 251            range, use that.
 252
 253            This is only required for source (ie. NAT/masq) mappings.
 254            So far, we don't do local source mappings, so multiple
 255            manips not an issue.  */
 256         if (maniptype == IP_NAT_MANIP_SRC) {
 257                 if (find_appropriate_src(orig_tuple, tuple, range)) {
 258                         DEBUGP("get_unique_tuple: Found current src map\n");
 259                         if (!(range->flags & IP_NAT_RANGE_PROTO_RANDOM))
 260                                 if (!nf_nat_used_tuple(tuple, ct))
 261                                         return;
 262                 }
 263         }
 264
 265         /* 2) Select the least-used IP/proto combination in the given
 266            range. */
 267         *tuple = *orig_tuple;
 268         find_best_ips_proto(tuple, range, ct, maniptype);
 269
 270         /* 3) The per-protocol part of the manip is made to map into
 271            the range to make a unique tuple. */
 272
 273         rcu_read_lock();
 274         proto = __nf_nat_proto_find(orig_tuple->dst.protonum);
 275
 276         /* Change protocol info to have some randomization */
 277         if (range->flags & IP_NAT_RANGE_PROTO_RANDOM) {
 278                 proto->unique_tuple(tuple, range, maniptype, ct);
 279                 goto out;
 280         }
 281
 282         /* Only bother mapping if it's not already in range and unique */
 283         if ((!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED) ||
 284              proto->in_range(tuple, maniptype, &range->min, &range->max)) &&
 285             !nf_nat_used_tuple(tuple, ct))
 286                 goto out;
 287
 288         /* Last change: get protocol to try to obtain unique tuple. */
 289         proto->unique_tuple(tuple, range, maniptype, ct);
 290 out:
 291         rcu_read_unlock();
 292 }
 293
 294 unsigned int
 295 nf_nat_setup_info(struct nf_conn *ct,
 296                   const struct nf_nat_range *range,
 297                   unsigned int hooknum)
 298 {
 299         struct nf_conntrack_tuple curr_tuple, new_tuple;
 300         struct nf_conn_nat *nat = nfct_nat(ct);
 301         struct nf_nat_info *info = &nat->info;
 302         int have_to_hash = !(ct->status & IPS_NAT_DONE_MASK);
 303         enum nf_nat_manip_type maniptype = HOOK2MANIP(hooknum);
 304
 305         NF_CT_ASSERT(hooknum == NF_IP_PRE_ROUTING ||
 306                      hooknum == NF_IP_POST_ROUTING ||
 307                      hooknum == NF_IP_LOCAL_IN ||
 308                      hooknum == NF_IP_LOCAL_OUT);
 309         BUG_ON(nf_nat_initialized(ct, maniptype));
 310
 311         /* What we've got will look like inverse of reply. Normally
 312            this is what is in the conntrack, except for prior
 313            manipulations (future optimization: if num_manips == 0,
 314            orig_tp =
 315            conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple) */
 316         nf_ct_invert_tuplepr(&curr_tuple,
 317                              &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 318
 319         get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype);
 320
 321         if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) {
 322                 struct nf_conntrack_tuple reply;
 323
 324                 /* Alter conntrack table so will recognize replies. */
 325                 nf_ct_invert_tuplepr(&reply, &new_tuple);
 326                 nf_conntrack_alter_reply(ct, &reply);
 327
 328                 /* Non-atomic: we own this at the moment. */
 329                 if (maniptype == IP_NAT_MANIP_SRC)
 330                         ct->status |= IPS_SRC_NAT;
 331                 else
 332                         ct->status |= IPS_DST_NAT;
 333         }
 334
 335         /* Place in source hash if this is the first time. */
 336         if (have_to_hash) {
 337                 unsigned int srchash;
 338
 339                 srchash = hash_by_src(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 340                 write_lock_bh(&nf_nat_lock);
 341                 info->ct = ct;
 342                 list_add(&info->bysource, &bysource[srchash]);
 343                 write_unlock_bh(&nf_nat_lock);
 344         }
 345
 346         /* It's done. */
 347         if (maniptype == IP_NAT_MANIP_DST)
 348                 set_bit(IPS_DST_NAT_DONE_BIT, &ct->status);
 349         else
 350                 set_bit(IPS_SRC_NAT_DONE_BIT, &ct->status);
 351
 352         return NF_ACCEPT;
 353 }
 354 EXPORT_SYMBOL(nf_nat_setup_info);
 355
 356 /* Returns true if succeeded. */
 357 static int
 358 manip_pkt(u_int16_t proto,
 359           struct sk_buff **pskb,
 360           unsigned int iphdroff,
 361           const struct nf_conntrack_tuple *target,
 362           enum nf_nat_manip_type maniptype)
 363 {
 364         struct iphdr *iph;
 365         struct nf_nat_protocol *p;
 366
 367         if (!skb_make_writable(pskb, iphdroff + sizeof(*iph)))
 368                 return 0;
 369
 370         iph = (void *)(*pskb)->data + iphdroff;
 371
 372         /* Manipulate protcol part. */
 373
 374         /* rcu_read_lock()ed by nf_hook_slow */
 375         p = __nf_nat_proto_find(proto);
 376         if (!p->manip_pkt(pskb, iphdroff, target, maniptype))
 377                 return 0;
 378
 379         iph = (void *)(*pskb)->data + iphdroff;
 380
 381         if (maniptype == IP_NAT_MANIP_SRC) {
 382                 nf_csum_replace4(&iph->check, iph->saddr, target->src.u3.ip);
 383                 iph->saddr = target->src.u3.ip;
 384         } else {
 385                 nf_csum_replace4(&iph->check, iph->daddr, target->dst.u3.ip);
 386                 iph->daddr = target->dst.u3.ip;
 387         }
 388         return 1;
 389 }
 390
 391 /* Do packet manipulations according to nf_nat_setup_info. */
 392 unsigned int nf_nat_packet(struct nf_conn *ct,
 393                            enum ip_conntrack_info ctinfo,
 394                            unsigned int hooknum,
 395                            struct sk_buff **pskb)
 396 {
 397         enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 398         unsigned long statusbit;
 399         enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum);
 400
 401         if (mtype == IP_NAT_MANIP_SRC)
 402                 statusbit = IPS_SRC_NAT;
 403         else
 404                 statusbit = IPS_DST_NAT;
 405
 406         /* Invert if this is reply dir. */
 407         if (dir == IP_CT_DIR_REPLY)
 408                 statusbit ^= IPS_NAT_MASK;
 409
 410         /* Non-atomic: these bits don't change. */
 411         if (ct->status & statusbit) {
 412                 struct nf_conntrack_tuple target;
 413
 414                 /* We are aiming to look like inverse of other direction. */
 415                 nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple);
 416
 417                 if (!manip_pkt(target.dst.protonum, pskb, 0, &target, mtype))
 418                         return NF_DROP;
 419         }
 420         return NF_ACCEPT;
 421 }
 422 EXPORT_SYMBOL_GPL(nf_nat_packet);
 423
 424 /* Dir is direction ICMP is coming from (opposite to packet it contains) */
 425 int nf_nat_icmp_reply_translation(struct nf_conn *ct,
 426                                   enum ip_conntrack_info ctinfo,
 427                                   unsigned int hooknum,
 428                                   struct sk_buff **pskb)
 429 {
 430         struct {
 431                 struct icmphdr icmp;
 432                 struct iphdr ip;
 433         } *inside;
 434         struct nf_conntrack_l4proto *l4proto;
 435         struct nf_conntrack_tuple inner, target;
 436         int hdrlen = ip_hdrlen(*pskb);
 437         enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 438         unsigned long statusbit;
 439         enum nf_nat_manip_type manip = HOOK2MANIP(hooknum);
 440
 441         if (!skb_make_writable(pskb, hdrlen + sizeof(*inside)))
 442                 return 0;
 443
 444         inside = (void *)(*pskb)->data + ip_hdrlen(*pskb);
 445
 446         /* We're actually going to mangle it beyond trivial checksum
 447            adjustment, so make sure the current checksum is correct. */
 448         if (nf_ip_checksum(*pskb, hooknum, hdrlen, 0))
 449                 return 0;
 450
 451         /* Must be RELATED */
 452         NF_CT_ASSERT((*pskb)->nfctinfo == IP_CT_RELATED ||
 453                      (*pskb)->nfctinfo == IP_CT_RELATED+IP_CT_IS_REPLY);
 454
 455         /* Redirects on non-null nats must be dropped, else they'll
 456            start talking to each other without our translation, and be
 457            confused... --RR */
 458         if (inside->icmp.type == ICMP_REDIRECT) {
 459                 /* If NAT isn't finished, assume it and drop. */
 460                 if ((ct->status & IPS_NAT_DONE_MASK) != IPS_NAT_DONE_MASK)
 461                         return 0;
 462
 463                 if (ct->status & IPS_NAT_MASK)
 464                         return 0;
 465         }
 466
 467         DEBUGP("icmp_reply_translation: translating error %p manp %u dir %s\n",
 468                *pskb, manip, dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY");
 469
 470         /* rcu_read_lock()ed by nf_hook_slow */
 471         l4proto = __nf_ct_l4proto_find(PF_INET, inside->ip.protocol);
 472
 473         if (!nf_ct_get_tuple(*pskb,
 474                              ip_hdrlen(*pskb) + sizeof(struct icmphdr),
 475                              (ip_hdrlen(*pskb) +
 476                               sizeof(struct icmphdr) + inside->ip.ihl * 4),
 477                              (u_int16_t)AF_INET,
 478                              inside->ip.protocol,
 479                              &inner, l3proto, l4proto))
 480                 return 0;
 481
 482         /* Change inner back to look like incoming packet.  We do the
 483            opposite manip on this hook to normal, because it might not
 484            pass all hooks (locally-generated ICMP).  Consider incoming
 485            packet: PREROUTING (DST manip), routing produces ICMP, goes
 486            through POSTROUTING (which must correct the DST manip). */
 487         if (!manip_pkt(inside->ip.protocol, pskb,
 488                        ip_hdrlen(*pskb) + sizeof(inside->icmp),
 489                        &ct->tuplehash[!dir].tuple,
 490                        !manip))
 491                 return 0;
 492
 493         if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) {
 494                 /* Reloading "inside" here since manip_pkt inner. */
 495                 inside = (void *)(*pskb)->data + ip_hdrlen(*pskb);
 496                 inside->icmp.checksum = 0;
 497                 inside->icmp.checksum =
 498                         csum_fold(skb_checksum(*pskb, hdrlen,
 499                                                (*pskb)->len - hdrlen, 0));
 500         }
 501
 502         /* Change outer to look the reply to an incoming packet
 503          * (proto 0 means don't invert per-proto part). */
 504         if (manip == IP_NAT_MANIP_SRC)
 505                 statusbit = IPS_SRC_NAT;
 506         else
 507                 statusbit = IPS_DST_NAT;
 508
 509         /* Invert if this is reply dir. */
 510         if (dir == IP_CT_DIR_REPLY)
 511                 statusbit ^= IPS_NAT_MASK;
 512
 513         if (ct->status & statusbit) {
 514                 nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple);
 515                 if (!manip_pkt(0, pskb, 0, &target, manip))
 516                         return 0;
 517         }
 518
 519         return 1;
 520 }
 521 EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation);
 522
 523 /* Protocol registration. */
 524 int nf_nat_protocol_register(struct nf_nat_protocol *proto)
 525 {
 526         int ret = 0;
 527
 528         write_lock_bh(&nf_nat_lock);
 529         if (nf_nat_protos[proto->protonum] != &nf_nat_unknown_protocol) {
 530                 ret = -EBUSY;
 531                 goto out;
 532         }
 533         rcu_assign_pointer(nf_nat_protos[proto->protonum], proto);
 534  out:
 535         write_unlock_bh(&nf_nat_lock);
 536         return ret;
 537 }
 538 EXPORT_SYMBOL(nf_nat_protocol_register);
 539
 540 /* Noone stores the protocol anywhere; simply delete it. */
 541 void nf_nat_protocol_unregister(struct nf_nat_protocol *proto)
 542 {
 543         write_lock_bh(&nf_nat_lock);
 544         rcu_assign_pointer(nf_nat_protos[proto->protonum],
 545                            &nf_nat_unknown_protocol);
 546         write_unlock_bh(&nf_nat_lock);
 547         synchronize_rcu();
 548 }
 549 EXPORT_SYMBOL(nf_nat_protocol_unregister);
 550
 551 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
 552 int
 553 nf_nat_port_range_to_nfattr(struct sk_buff *skb,
 554                             const struct nf_nat_range *range)
 555 {
 556         NFA_PUT(skb, CTA_PROTONAT_PORT_MIN, sizeof(__be16),
 557                 &range->min.tcp.port);
 558         NFA_PUT(skb, CTA_PROTONAT_PORT_MAX, sizeof(__be16),
 559                 &range->max.tcp.port);
 560
 561         return 0;
 562
 563 nfattr_failure:
 564         return -1;
 565 }
 566 EXPORT_SYMBOL_GPL(nf_nat_port_nfattr_to_range);
 567
 568 int
 569 nf_nat_port_nfattr_to_range(struct nfattr *tb[], struct nf_nat_range *range)
 570 {
 571         int ret = 0;
 572
 573         /* we have to return whether we actually parsed something or not */
 574
 575         if (tb[CTA_PROTONAT_PORT_MIN-1]) {
 576                 ret = 1;
 577                 range->min.tcp.port =
 578                         *(__be16 *)NFA_DATA(tb[CTA_PROTONAT_PORT_MIN-1]);
 579         }
 580
 581         if (!tb[CTA_PROTONAT_PORT_MAX-1]) {
 582                 if (ret)
 583                         range->max.tcp.port = range->min.tcp.port;
 584         } else {
 585                 ret = 1;
 586                 range->max.tcp.port =
 587                         *(__be16 *)NFA_DATA(tb[CTA_PROTONAT_PORT_MAX-1]);
 588         }
 589
 590         return ret;
 591 }
 592 EXPORT_SYMBOL_GPL(nf_nat_port_range_to_nfattr);
 593 #endif
 594
 595 static int __init nf_nat_init(void)
 596 {
 597         size_t i;
 598
 599         /* Leave them the same for the moment. */
 600         nf_nat_htable_size = nf_conntrack_htable_size;
 601
 602         /* One vmalloc for both hash tables */
 603         bysource = vmalloc(sizeof(struct list_head) * nf_nat_htable_size);
 604         if (!bysource)
 605                 return -ENOMEM;
 606
 607         /* Sew in builtin protocols. */
 608         write_lock_bh(&nf_nat_lock);
 609         for (i = 0; i < MAX_IP_NAT_PROTO; i++)
 610                 rcu_assign_pointer(nf_nat_protos[i], &nf_nat_unknown_protocol);
 611         rcu_assign_pointer(nf_nat_protos[IPPROTO_TCP], &nf_nat_protocol_tcp);
 612         rcu_assign_pointer(nf_nat_protos[IPPROTO_UDP], &nf_nat_protocol_udp);
 613         rcu_assign_pointer(nf_nat_protos[IPPROTO_ICMP], &nf_nat_protocol_icmp);
 614         write_unlock_bh(&nf_nat_lock);
 615
 616         for (i = 0; i < nf_nat_htable_size; i++) {
 617                 INIT_LIST_HEAD(&bysource[i]);
 618         }
 619
 620         /* FIXME: Man, this is a hack.  <SIGH> */
 621         NF_CT_ASSERT(rcu_dereference(nf_conntrack_destroyed) == NULL);
 622         rcu_assign_pointer(nf_conntrack_destroyed, nf_nat_cleanup_conntrack);
 623
 624         /* Initialize fake conntrack so that NAT will skip it */
 625         nf_conntrack_untracked.status |= IPS_NAT_DONE_MASK;
 626
 627         l3proto = nf_ct_l3proto_find_get((u_int16_t)AF_INET);
 628         return 0;
 629 }
 630
 631 /* Clear NAT section of all conntracks, in case we're loaded again. */
 632 static int clean_nat(struct nf_conn *i, void *data)
 633 {
 634         struct nf_conn_nat *nat = nfct_nat(i);
 635
 636         if (!nat)
 637                 return 0;
 638         memset(nat, 0, sizeof(nat));
 639         i->status &= ~(IPS_NAT_MASK | IPS_NAT_DONE_MASK | IPS_SEQ_ADJUST);
 640         return 0;
 641 }
 642
 643 static void __exit nf_nat_cleanup(void)
 644 {
 645         nf_ct_iterate_cleanup(&clean_nat, NULL);
 646         rcu_assign_pointer(nf_conntrack_destroyed, NULL);
 647         synchronize_rcu();
 648         vfree(bysource);
 649         nf_ct_l3proto_put(l3proto);
 650 }
 651
 652 MODULE_LICENSE("GPL");
 653
 654 module_init(nf_nat_init);
 655 module_exit(nf_nat_cleanup);