net/netfilter/nf_flow_table_core.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <linux/kernel.h>
   3 #include <linux/init.h>
   4 #include <linux/module.h>
   5 #include <linux/netfilter.h>
   6 #include <linux/rhashtable.h>
   7 #include <linux/netdevice.h>
   8 #include <net/ip.h>
   9 #include <net/ip6_route.h>
  10 #include <net/netfilter/nf_tables.h>
  11 #include <net/netfilter/nf_flow_table.h>
  12 #include <net/netfilter/nf_conntrack.h>
  13 #include <net/netfilter/nf_conntrack_core.h>
  14 #include <net/netfilter/nf_conntrack_l4proto.h>
  15 #include <net/netfilter/nf_conntrack_tuple.h>
  16
  17 static DEFINE_MUTEX(flowtable_lock);
  18 static LIST_HEAD(flowtables);
  19
  20 static void
  21 flow_offload_fill_dir(struct flow_offload *flow,
  22                       enum flow_offload_tuple_dir dir)
  23 {
  24         struct flow_offload_tuple *ft = &flow->tuplehash[dir].tuple;
  25         struct nf_conntrack_tuple *ctt = &flow->ct->tuplehash[dir].tuple;
  26
  27         ft->dir = dir;
  28
  29         switch (ctt->src.l3num) {
  30         case NFPROTO_IPV4:
  31                 ft->src_v4 = ctt->src.u3.in;
  32                 ft->dst_v4 = ctt->dst.u3.in;
  33                 break;
  34         case NFPROTO_IPV6:
  35                 ft->src_v6 = ctt->src.u3.in6;
  36                 ft->dst_v6 = ctt->dst.u3.in6;
  37                 break;
  38         }
  39
  40         ft->l3proto = ctt->src.l3num;
  41         ft->l4proto = ctt->dst.protonum;
  42         ft->src_port = ctt->src.u.tcp.port;
  43         ft->dst_port = ctt->dst.u.tcp.port;
  44 }
  45
  46 struct flow_offload *flow_offload_alloc(struct nf_conn *ct)
  47 {
  48         struct flow_offload *flow;
  49
  50         if (unlikely(nf_ct_is_dying(ct) ||
  51             !atomic_inc_not_zero(&ct->ct_general.use)))
  52                 return NULL;
  53
  54         flow = kzalloc(sizeof(*flow), GFP_ATOMIC);
  55         if (!flow)
  56                 goto err_ct_refcnt;
  57
  58         flow->ct = ct;
  59
  60         flow_offload_fill_dir(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
  61         flow_offload_fill_dir(flow, FLOW_OFFLOAD_DIR_REPLY);
  62
  63         if (ct->status & IPS_SRC_NAT)
  64                 __set_bit(NF_FLOW_SNAT, &flow->flags);
  65         if (ct->status & IPS_DST_NAT)
  66                 __set_bit(NF_FLOW_DNAT, &flow->flags);
  67
  68         return flow;
  69
  70 err_ct_refcnt:
  71         nf_ct_put(ct);
  72
  73         return NULL;
  74 }
  75 EXPORT_SYMBOL_GPL(flow_offload_alloc);
  76
  77 static u32 flow_offload_dst_cookie(struct flow_offload_tuple *flow_tuple)
  78 {
  79         const struct rt6_info *rt;
  80
  81         if (flow_tuple->l3proto == NFPROTO_IPV6) {
  82                 rt = (const struct rt6_info *)flow_tuple->dst_cache;
  83                 return rt6_get_cookie(rt);
  84         }
  85
  86         return 0;
  87 }
  88
  89 static int flow_offload_fill_route(struct flow_offload *flow,
  90                                    const struct nf_flow_route *route,
  91                                    enum flow_offload_tuple_dir dir)
  92 {
  93         struct flow_offload_tuple *flow_tuple = &flow->tuplehash[dir].tuple;
  94         struct dst_entry *dst = route->tuple[dir].dst;
  95         int i, j = 0;
  96
  97         switch (flow_tuple->l3proto) {
  98         case NFPROTO_IPV4:
  99                 flow_tuple->mtu = ip_dst_mtu_maybe_forward(dst, true);
 100                 break;
 101         case NFPROTO_IPV6:
 102                 flow_tuple->mtu = ip6_dst_mtu_forward(dst);
 103                 break;
 104         }
 105
 106         flow_tuple->iifidx = route->tuple[dir].in.ifindex;
 107         for (i = route->tuple[dir].in.num_encaps - 1; i >= 0; i--) {
 108                 flow_tuple->encap[j].id = route->tuple[dir].in.encap[i].id;
 109                 flow_tuple->encap[j].proto = route->tuple[dir].in.encap[i].proto;
 110                 if (route->tuple[dir].in.ingress_vlans & BIT(i))
 111                         flow_tuple->in_vlan_ingress |= BIT(j);
 112                 j++;
 113         }
 114         flow_tuple->encap_num = route->tuple[dir].in.num_encaps;
 115
 116         switch (route->tuple[dir].xmit_type) {
 117         case FLOW_OFFLOAD_XMIT_DIRECT:
 118                 memcpy(flow_tuple->out.h_dest, route->tuple[dir].out.h_dest,
 119                        ETH_ALEN);
 120                 memcpy(flow_tuple->out.h_source, route->tuple[dir].out.h_source,
 121                        ETH_ALEN);
 122                 flow_tuple->out.ifidx = route->tuple[dir].out.ifindex;
 123                 flow_tuple->out.hw_ifidx = route->tuple[dir].out.hw_ifindex;
 124                 break;
 125         case FLOW_OFFLOAD_XMIT_XFRM:
 126         case FLOW_OFFLOAD_XMIT_NEIGH:
 127                 if (!dst_hold_safe(route->tuple[dir].dst))
 128                         return -1;
 129
 130                 flow_tuple->dst_cache = dst;
 131                 flow_tuple->dst_cookie = flow_offload_dst_cookie(flow_tuple);
 132                 break;
 133         default:
 134                 WARN_ON_ONCE(1);
 135                 break;
 136         }
 137         flow_tuple->xmit_type = route->tuple[dir].xmit_type;
 138
 139         return 0;
 140 }
 141
 142 static void nft_flow_dst_release(struct flow_offload *flow,
 143                                  enum flow_offload_tuple_dir dir)
 144 {
 145         if (flow->tuplehash[dir].tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
 146             flow->tuplehash[dir].tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)
 147                 dst_release(flow->tuplehash[dir].tuple.dst_cache);
 148 }
 149
 150 int flow_offload_route_init(struct flow_offload *flow,
 151                             const struct nf_flow_route *route)
 152 {
 153         int err;
 154
 155         err = flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_ORIGINAL);
 156         if (err < 0)
 157                 return err;
 158
 159         err = flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_REPLY);
 160         if (err < 0)
 161                 goto err_route_reply;
 162
 163         flow->type = NF_FLOW_OFFLOAD_ROUTE;
 164
 165         return 0;
 166
 167 err_route_reply:
 168         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
 169
 170         return err;
 171 }
 172 EXPORT_SYMBOL_GPL(flow_offload_route_init);
 173
 174 static void flow_offload_fixup_tcp(struct ip_ct_tcp *tcp)
 175 {
 176         tcp->state = TCP_CONNTRACK_ESTABLISHED;
 177         tcp->seen[0].td_maxwin = 0;
 178         tcp->seen[1].td_maxwin = 0;
 179 }
 180
 181 #define NF_FLOWTABLE_TCP_PICKUP_TIMEOUT (120 * HZ)
 182 #define NF_FLOWTABLE_UDP_PICKUP_TIMEOUT (30 * HZ)
 183
 184 static void flow_offload_fixup_ct_timeout(struct nf_conn *ct)
 185 {
 186         const struct nf_conntrack_l4proto *l4proto;
 187         int l4num = nf_ct_protonum(ct);
 188         unsigned int timeout;
 189
 190         l4proto = nf_ct_l4proto_find(l4num);
 191         if (!l4proto)
 192                 return;
 193
 194         if (l4num == IPPROTO_TCP)
 195                 timeout = NF_FLOWTABLE_TCP_PICKUP_TIMEOUT;
 196         else if (l4num == IPPROTO_UDP)
 197                 timeout = NF_FLOWTABLE_UDP_PICKUP_TIMEOUT;
 198         else
 199                 return;
 200
 201         if (nf_flow_timeout_delta(ct->timeout) > (__s32)timeout)
 202                 ct->timeout = nfct_time_stamp + timeout;
 203 }
 204
 205 static void flow_offload_fixup_ct_state(struct nf_conn *ct)
 206 {
 207         if (nf_ct_protonum(ct) == IPPROTO_TCP)
 208                 flow_offload_fixup_tcp(&ct->proto.tcp);
 209 }
 210
 211 static void flow_offload_fixup_ct(struct nf_conn *ct)
 212 {
 213         flow_offload_fixup_ct_state(ct);
 214         flow_offload_fixup_ct_timeout(ct);
 215 }
 216
 217 static void flow_offload_route_release(struct flow_offload *flow)
 218 {
 219         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
 220         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_REPLY);
 221 }
 222
 223 void flow_offload_free(struct flow_offload *flow)
 224 {
 225         switch (flow->type) {
 226         case NF_FLOW_OFFLOAD_ROUTE:
 227                 flow_offload_route_release(flow);
 228                 break;
 229         default:
 230                 break;
 231         }
 232         nf_ct_put(flow->ct);
 233         kfree_rcu(flow, rcu_head);
 234 }
 235 EXPORT_SYMBOL_GPL(flow_offload_free);
 236
 237 static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
 238 {
 239         const struct flow_offload_tuple *tuple = data;
 240
 241         return jhash(tuple, offsetof(struct flow_offload_tuple, __hash), seed);
 242 }
 243
 244 static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
 245 {
 246         const struct flow_offload_tuple_rhash *tuplehash = data;
 247
 248         return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, __hash), seed);
 249 }
 250
 251 static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
 252                                         const void *ptr)
 253 {
 254         const struct flow_offload_tuple *tuple = arg->key;
 255         const struct flow_offload_tuple_rhash *x = ptr;
 256
 257         if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, __hash)))
 258                 return 1;
 259
 260         return 0;
 261 }
 262
 263 static const struct rhashtable_params nf_flow_offload_rhash_params = {
 264         .head_offset            = offsetof(struct flow_offload_tuple_rhash, node),
 265         .hashfn                 = flow_offload_hash,
 266         .obj_hashfn             = flow_offload_hash_obj,
 267         .obj_cmpfn              = flow_offload_hash_cmp,
 268         .automatic_shrinking    = true,
 269 };
 270
 271 int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow)
 272 {
 273         int err;
 274
 275         flow->timeout = nf_flowtable_time_stamp + NF_FLOW_TIMEOUT;
 276
 277         err = rhashtable_insert_fast(&flow_table->rhashtable,
 278                                      &flow->tuplehash[0].node,
 279                                      nf_flow_offload_rhash_params);
 280         if (err < 0)
 281                 return err;
 282
 283         err = rhashtable_insert_fast(&flow_table->rhashtable,
 284                                      &flow->tuplehash[1].node,
 285                                      nf_flow_offload_rhash_params);
 286         if (err < 0) {
 287                 rhashtable_remove_fast(&flow_table->rhashtable,
 288                                        &flow->tuplehash[0].node,
 289                                        nf_flow_offload_rhash_params);
 290                 return err;
 291         }
 292
 293         nf_ct_offload_timeout(flow->ct);
 294
 295         if (nf_flowtable_hw_offload(flow_table)) {
 296                 __set_bit(NF_FLOW_HW, &flow->flags);
 297                 nf_flow_offload_add(flow_table, flow);
 298         }
 299
 300         return 0;
 301 }
 302 EXPORT_SYMBOL_GPL(flow_offload_add);
 303
 304 void flow_offload_refresh(struct nf_flowtable *flow_table,
 305                           struct flow_offload *flow)
 306 {
 307         flow->timeout = nf_flowtable_time_stamp + NF_FLOW_TIMEOUT;
 308
 309         if (likely(!nf_flowtable_hw_offload(flow_table)))
 310                 return;
 311
 312         nf_flow_offload_add(flow_table, flow);
 313 }
 314 EXPORT_SYMBOL_GPL(flow_offload_refresh);
 315
 316 static inline bool nf_flow_has_expired(const struct flow_offload *flow)
 317 {
 318         return nf_flow_timeout_delta(flow->timeout) <= 0;
 319 }
 320
 321 static void flow_offload_del(struct nf_flowtable *flow_table,
 322                              struct flow_offload *flow)
 323 {
 324         rhashtable_remove_fast(&flow_table->rhashtable,
 325                                &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
 326                                nf_flow_offload_rhash_params);
 327         rhashtable_remove_fast(&flow_table->rhashtable,
 328                                &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
 329                                nf_flow_offload_rhash_params);
 330
 331         clear_bit(IPS_OFFLOAD_BIT, &flow->ct->status);
 332
 333         if (nf_flow_has_expired(flow))
 334                 flow_offload_fixup_ct(flow->ct);
 335         else
 336                 flow_offload_fixup_ct_timeout(flow->ct);
 337
 338         flow_offload_free(flow);
 339 }
 340
 341 void flow_offload_teardown(struct flow_offload *flow)
 342 {
 343         set_bit(NF_FLOW_TEARDOWN, &flow->flags);
 344
 345         flow_offload_fixup_ct_state(flow->ct);
 346 }
 347 EXPORT_SYMBOL_GPL(flow_offload_teardown);
 348
 349 struct flow_offload_tuple_rhash *
 350 flow_offload_lookup(struct nf_flowtable *flow_table,
 351                     struct flow_offload_tuple *tuple)
 352 {
 353         struct flow_offload_tuple_rhash *tuplehash;
 354         struct flow_offload *flow;
 355         int dir;
 356
 357         tuplehash = rhashtable_lookup(&flow_table->rhashtable, tuple,
 358                                       nf_flow_offload_rhash_params);
 359         if (!tuplehash)
 360                 return NULL;
 361
 362         dir = tuplehash->tuple.dir;
 363         flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
 364         if (test_bit(NF_FLOW_TEARDOWN, &flow->flags))
 365                 return NULL;
 366
 367         if (unlikely(nf_ct_is_dying(flow->ct)))
 368                 return NULL;
 369
 370         return tuplehash;
 371 }
 372 EXPORT_SYMBOL_GPL(flow_offload_lookup);
 373
 374 static int
 375 nf_flow_table_iterate(struct nf_flowtable *flow_table,
 376                       void (*iter)(struct flow_offload *flow, void *data),
 377                       void *data)
 378 {
 379         struct flow_offload_tuple_rhash *tuplehash;
 380         struct rhashtable_iter hti;
 381         struct flow_offload *flow;
 382         int err = 0;
 383
 384         rhashtable_walk_enter(&flow_table->rhashtable, &hti);
 385         rhashtable_walk_start(&hti);
 386
 387         while ((tuplehash = rhashtable_walk_next(&hti))) {
 388                 if (IS_ERR(tuplehash)) {
 389                         if (PTR_ERR(tuplehash) != -EAGAIN) {
 390                                 err = PTR_ERR(tuplehash);
 391                                 break;
 392                         }
 393                         continue;
 394                 }
 395                 if (tuplehash->tuple.dir)
 396                         continue;
 397
 398                 flow = container_of(tuplehash, struct flow_offload, tuplehash[0]);
 399
 400                 iter(flow, data);
 401         }
 402         rhashtable_walk_stop(&hti);
 403         rhashtable_walk_exit(&hti);
 404
 405         return err;
 406 }
 407
 408 static bool flow_offload_stale_dst(struct flow_offload_tuple *tuple)
 409 {
 410         struct dst_entry *dst;
 411
 412         if (tuple->xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
 413             tuple->xmit_type == FLOW_OFFLOAD_XMIT_XFRM) {
 414                 dst = tuple->dst_cache;
 415                 if (!dst_check(dst, tuple->dst_cookie))
 416                         return true;
 417         }
 418
 419         return false;
 420 }
 421
 422 static bool nf_flow_has_stale_dst(struct flow_offload *flow)
 423 {
 424         return flow_offload_stale_dst(&flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple) ||
 425                flow_offload_stale_dst(&flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple);
 426 }
 427
 428 static void nf_flow_offload_gc_step(struct flow_offload *flow, void *data)
 429 {
 430         struct nf_flowtable *flow_table = data;
 431
 432         if (nf_flow_has_expired(flow) ||
 433             nf_ct_is_dying(flow->ct) ||
 434             nf_flow_has_stale_dst(flow))
 435                 set_bit(NF_FLOW_TEARDOWN, &flow->flags);
 436
 437         if (test_bit(NF_FLOW_TEARDOWN, &flow->flags)) {
 438                 if (test_bit(NF_FLOW_HW, &flow->flags)) {
 439                         if (!test_bit(NF_FLOW_HW_DYING, &flow->flags))
 440                                 nf_flow_offload_del(flow_table, flow);
 441                         else if (test_bit(NF_FLOW_HW_DEAD, &flow->flags))
 442                                 flow_offload_del(flow_table, flow);
 443                 } else {
 444                         flow_offload_del(flow_table, flow);
 445                 }
 446         } else if (test_bit(NF_FLOW_HW, &flow->flags)) {
 447                 nf_flow_offload_stats(flow_table, flow);
 448         }
 449 }
 450
 451 static void nf_flow_offload_work_gc(struct work_struct *work)
 452 {
 453         struct nf_flowtable *flow_table;
 454
 455         flow_table = container_of(work, struct nf_flowtable, gc_work.work);
 456         nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
 457         queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ);
 458 }
 459
 460 static void nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff,
 461                                  __be16 port, __be16 new_port)
 462 {
 463         struct tcphdr *tcph;
 464
 465         tcph = (void *)(skb_network_header(skb) + thoff);
 466         inet_proto_csum_replace2(&tcph->check, skb, port, new_port, false);
 467 }
 468
 469 static void nf_flow_nat_port_udp(struct sk_buff *skb, unsigned int thoff,
 470                                  __be16 port, __be16 new_port)
 471 {
 472         struct udphdr *udph;
 473
 474         udph = (void *)(skb_network_header(skb) + thoff);
 475         if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 476                 inet_proto_csum_replace2(&udph->check, skb, port,
 477                                          new_port, false);
 478                 if (!udph->check)
 479                         udph->check = CSUM_MANGLED_0;
 480         }
 481 }
 482
 483 static void nf_flow_nat_port(struct sk_buff *skb, unsigned int thoff,
 484                              u8 protocol, __be16 port, __be16 new_port)
 485 {
 486         switch (protocol) {
 487         case IPPROTO_TCP:
 488                 nf_flow_nat_port_tcp(skb, thoff, port, new_port);
 489                 break;
 490         case IPPROTO_UDP:
 491                 nf_flow_nat_port_udp(skb, thoff, port, new_port);
 492                 break;
 493         }
 494 }
 495
 496 void nf_flow_snat_port(const struct flow_offload *flow,
 497                        struct sk_buff *skb, unsigned int thoff,
 498                        u8 protocol, enum flow_offload_tuple_dir dir)
 499 {
 500         struct flow_ports *hdr;
 501         __be16 port, new_port;
 502
 503         hdr = (void *)(skb_network_header(skb) + thoff);
 504
 505         switch (dir) {
 506         case FLOW_OFFLOAD_DIR_ORIGINAL:
 507                 port = hdr->source;
 508                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port;
 509                 hdr->source = new_port;
 510                 break;
 511         case FLOW_OFFLOAD_DIR_REPLY:
 512                 port = hdr->dest;
 513                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port;
 514                 hdr->dest = new_port;
 515                 break;
 516         }
 517
 518         nf_flow_nat_port(skb, thoff, protocol, port, new_port);
 519 }
 520 EXPORT_SYMBOL_GPL(nf_flow_snat_port);
 521
 522 void nf_flow_dnat_port(const struct flow_offload *flow, struct sk_buff *skb,
 523                        unsigned int thoff, u8 protocol,
 524                        enum flow_offload_tuple_dir dir)
 525 {
 526         struct flow_ports *hdr;
 527         __be16 port, new_port;
 528
 529         hdr = (void *)(skb_network_header(skb) + thoff);
 530
 531         switch (dir) {
 532         case FLOW_OFFLOAD_DIR_ORIGINAL:
 533                 port = hdr->dest;
 534                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port;
 535                 hdr->dest = new_port;
 536                 break;
 537         case FLOW_OFFLOAD_DIR_REPLY:
 538                 port = hdr->source;
 539                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port;
 540                 hdr->source = new_port;
 541                 break;
 542         }
 543
 544         nf_flow_nat_port(skb, thoff, protocol, port, new_port);
 545 }
 546 EXPORT_SYMBOL_GPL(nf_flow_dnat_port);
 547
 548 int nf_flow_table_init(struct nf_flowtable *flowtable)
 549 {
 550         int err;
 551
 552         INIT_DELAYED_WORK(&flowtable->gc_work, nf_flow_offload_work_gc);
 553         flow_block_init(&flowtable->flow_block);
 554         init_rwsem(&flowtable->flow_block_lock);
 555
 556         err = rhashtable_init(&flowtable->rhashtable,
 557                               &nf_flow_offload_rhash_params);
 558         if (err < 0)
 559                 return err;
 560
 561         queue_delayed_work(system_power_efficient_wq,
 562                            &flowtable->gc_work, HZ);
 563
 564         mutex_lock(&flowtable_lock);
 565         list_add(&flowtable->list, &flowtables);
 566         mutex_unlock(&flowtable_lock);
 567
 568         return 0;
 569 }
 570 EXPORT_SYMBOL_GPL(nf_flow_table_init);
 571
 572 static void nf_flow_table_do_cleanup(struct flow_offload *flow, void *data)
 573 {
 574         struct net_device *dev = data;
 575
 576         if (!dev) {
 577                 flow_offload_teardown(flow);
 578                 return;
 579         }
 580
 581         if (net_eq(nf_ct_net(flow->ct), dev_net(dev)) &&
 582             (flow->tuplehash[0].tuple.iifidx == dev->ifindex ||
 583              flow->tuplehash[1].tuple.iifidx == dev->ifindex))
 584                 flow_offload_teardown(flow);
 585 }
 586
 587 void nf_flow_table_gc_cleanup(struct nf_flowtable *flowtable,
 588                               struct net_device *dev)
 589 {
 590         nf_flow_table_iterate(flowtable, nf_flow_table_do_cleanup, dev);
 591         flush_delayed_work(&flowtable->gc_work);
 592         nf_flow_table_offload_flush(flowtable);
 593 }
 594
 595 void nf_flow_table_cleanup(struct net_device *dev)
 596 {
 597         struct nf_flowtable *flowtable;
 598
 599         mutex_lock(&flowtable_lock);
 600         list_for_each_entry(flowtable, &flowtables, list)
 601                 nf_flow_table_gc_cleanup(flowtable, dev);
 602         mutex_unlock(&flowtable_lock);
 603 }
 604 EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);
 605
 606 void nf_flow_table_free(struct nf_flowtable *flow_table)
 607 {
 608         mutex_lock(&flowtable_lock);
 609         list_del(&flow_table->list);
 610         mutex_unlock(&flowtable_lock);
 611
 612         cancel_delayed_work_sync(&flow_table->gc_work);
 613         nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
 614         nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
 615         nf_flow_table_offload_flush(flow_table);
 616         if (nf_flowtable_hw_offload(flow_table))
 617                 nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step,
 618                                       flow_table);
 619         rhashtable_destroy(&flow_table->rhashtable);
 620 }
 621 EXPORT_SYMBOL_GPL(nf_flow_table_free);
 622
 623 static int __init nf_flow_table_module_init(void)
 624 {
 625         return nf_flow_table_offload_init();
 626 }
 627
 628 static void __exit nf_flow_table_module_exit(void)
 629 {
 630         nf_flow_table_offload_exit();
 631 }
 632
 633 module_init(nf_flow_table_module_init);
 634 module_exit(nf_flow_table_module_exit);
 635
 636 MODULE_LICENSE("GPL");
 637 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
 638 MODULE_DESCRIPTION("Netfilter flow table module");