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         }
 134         flow_tuple->xmit_type = route->tuple[dir].xmit_type;
 135
 136         return 0;
 137 }
 138
 139 static void nft_flow_dst_release(struct flow_offload *flow,
 140                                  enum flow_offload_tuple_dir dir)
 141 {
 142         if (flow->tuplehash[dir].tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
 143             flow->tuplehash[dir].tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)
 144                 dst_release(flow->tuplehash[dir].tuple.dst_cache);
 145 }
 146
 147 int flow_offload_route_init(struct flow_offload *flow,
 148                             const struct nf_flow_route *route)
 149 {
 150         int err;
 151
 152         err = flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_ORIGINAL);
 153         if (err < 0)
 154                 return err;
 155
 156         err = flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_REPLY);
 157         if (err < 0)
 158                 goto err_route_reply;
 159
 160         flow->type = NF_FLOW_OFFLOAD_ROUTE;
 161
 162         return 0;
 163
 164 err_route_reply:
 165         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
 166
 167         return err;
 168 }
 169 EXPORT_SYMBOL_GPL(flow_offload_route_init);
 170
 171 static void flow_offload_fixup_tcp(struct ip_ct_tcp *tcp)
 172 {
 173         tcp->state = TCP_CONNTRACK_ESTABLISHED;
 174         tcp->seen[0].td_maxwin = 0;
 175         tcp->seen[1].td_maxwin = 0;
 176 }
 177
 178 #define NF_FLOWTABLE_TCP_PICKUP_TIMEOUT (120 * HZ)
 179 #define NF_FLOWTABLE_UDP_PICKUP_TIMEOUT (30 * HZ)
 180
 181 static void flow_offload_fixup_ct_timeout(struct nf_conn *ct)
 182 {
 183         const struct nf_conntrack_l4proto *l4proto;
 184         int l4num = nf_ct_protonum(ct);
 185         unsigned int timeout;
 186
 187         l4proto = nf_ct_l4proto_find(l4num);
 188         if (!l4proto)
 189                 return;
 190
 191         if (l4num == IPPROTO_TCP)
 192                 timeout = NF_FLOWTABLE_TCP_PICKUP_TIMEOUT;
 193         else if (l4num == IPPROTO_UDP)
 194                 timeout = NF_FLOWTABLE_UDP_PICKUP_TIMEOUT;
 195         else
 196                 return;
 197
 198         if (nf_flow_timeout_delta(ct->timeout) > (__s32)timeout)
 199                 ct->timeout = nfct_time_stamp + timeout;
 200 }
 201
 202 static void flow_offload_fixup_ct_state(struct nf_conn *ct)
 203 {
 204         if (nf_ct_protonum(ct) == IPPROTO_TCP)
 205                 flow_offload_fixup_tcp(&ct->proto.tcp);
 206 }
 207
 208 static void flow_offload_fixup_ct(struct nf_conn *ct)
 209 {
 210         flow_offload_fixup_ct_state(ct);
 211         flow_offload_fixup_ct_timeout(ct);
 212 }
 213
 214 static void flow_offload_route_release(struct flow_offload *flow)
 215 {
 216         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
 217         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_REPLY);
 218 }
 219
 220 void flow_offload_free(struct flow_offload *flow)
 221 {
 222         switch (flow->type) {
 223         case NF_FLOW_OFFLOAD_ROUTE:
 224                 flow_offload_route_release(flow);
 225                 break;
 226         default:
 227                 break;
 228         }
 229         nf_ct_put(flow->ct);
 230         kfree_rcu(flow, rcu_head);
 231 }
 232 EXPORT_SYMBOL_GPL(flow_offload_free);
 233
 234 static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
 235 {
 236         const struct flow_offload_tuple *tuple = data;
 237
 238         return jhash(tuple, offsetof(struct flow_offload_tuple, __hash), seed);
 239 }
 240
 241 static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
 242 {
 243         const struct flow_offload_tuple_rhash *tuplehash = data;
 244
 245         return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, __hash), seed);
 246 }
 247
 248 static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
 249                                         const void *ptr)
 250 {
 251         const struct flow_offload_tuple *tuple = arg->key;
 252         const struct flow_offload_tuple_rhash *x = ptr;
 253
 254         if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, __hash)))
 255                 return 1;
 256
 257         return 0;
 258 }
 259
 260 static const struct rhashtable_params nf_flow_offload_rhash_params = {
 261         .head_offset            = offsetof(struct flow_offload_tuple_rhash, node),
 262         .hashfn                 = flow_offload_hash,
 263         .obj_hashfn             = flow_offload_hash_obj,
 264         .obj_cmpfn              = flow_offload_hash_cmp,
 265         .automatic_shrinking    = true,
 266 };
 267
 268 int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow)
 269 {
 270         int err;
 271
 272         flow->timeout = nf_flowtable_time_stamp + NF_FLOW_TIMEOUT;
 273
 274         err = rhashtable_insert_fast(&flow_table->rhashtable,
 275                                      &flow->tuplehash[0].node,
 276                                      nf_flow_offload_rhash_params);
 277         if (err < 0)
 278                 return err;
 279
 280         err = rhashtable_insert_fast(&flow_table->rhashtable,
 281                                      &flow->tuplehash[1].node,
 282                                      nf_flow_offload_rhash_params);
 283         if (err < 0) {
 284                 rhashtable_remove_fast(&flow_table->rhashtable,
 285                                        &flow->tuplehash[0].node,
 286                                        nf_flow_offload_rhash_params);
 287                 return err;
 288         }
 289
 290         nf_ct_offload_timeout(flow->ct);
 291
 292         if (nf_flowtable_hw_offload(flow_table)) {
 293                 __set_bit(NF_FLOW_HW, &flow->flags);
 294                 nf_flow_offload_add(flow_table, flow);
 295         }
 296
 297         return 0;
 298 }
 299 EXPORT_SYMBOL_GPL(flow_offload_add);
 300
 301 void flow_offload_refresh(struct nf_flowtable *flow_table,
 302                           struct flow_offload *flow)
 303 {
 304         flow->timeout = nf_flowtable_time_stamp + NF_FLOW_TIMEOUT;
 305
 306         if (likely(!nf_flowtable_hw_offload(flow_table) ||
 307                    !test_and_clear_bit(NF_FLOW_HW_REFRESH, &flow->flags)))
 308                 return;
 309
 310         nf_flow_offload_add(flow_table, flow);
 311 }
 312 EXPORT_SYMBOL_GPL(flow_offload_refresh);
 313
 314 static inline bool nf_flow_has_expired(const struct flow_offload *flow)
 315 {
 316         return nf_flow_timeout_delta(flow->timeout) <= 0;
 317 }
 318
 319 static void flow_offload_del(struct nf_flowtable *flow_table,
 320                              struct flow_offload *flow)
 321 {
 322         rhashtable_remove_fast(&flow_table->rhashtable,
 323                                &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
 324                                nf_flow_offload_rhash_params);
 325         rhashtable_remove_fast(&flow_table->rhashtable,
 326                                &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
 327                                nf_flow_offload_rhash_params);
 328
 329         clear_bit(IPS_OFFLOAD_BIT, &flow->ct->status);
 330
 331         if (nf_flow_has_expired(flow))
 332                 flow_offload_fixup_ct(flow->ct);
 333         else
 334                 flow_offload_fixup_ct_timeout(flow->ct);
 335
 336         flow_offload_free(flow);
 337 }
 338
 339 void flow_offload_teardown(struct flow_offload *flow)
 340 {
 341         set_bit(NF_FLOW_TEARDOWN, &flow->flags);
 342
 343         flow_offload_fixup_ct_state(flow->ct);
 344 }
 345 EXPORT_SYMBOL_GPL(flow_offload_teardown);
 346
 347 struct flow_offload_tuple_rhash *
 348 flow_offload_lookup(struct nf_flowtable *flow_table,
 349                     struct flow_offload_tuple *tuple)
 350 {
 351         struct flow_offload_tuple_rhash *tuplehash;
 352         struct flow_offload *flow;
 353         int dir;
 354
 355         tuplehash = rhashtable_lookup(&flow_table->rhashtable, tuple,
 356                                       nf_flow_offload_rhash_params);
 357         if (!tuplehash)
 358                 return NULL;
 359
 360         dir = tuplehash->tuple.dir;
 361         flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
 362         if (test_bit(NF_FLOW_TEARDOWN, &flow->flags))
 363                 return NULL;
 364
 365         if (unlikely(nf_ct_is_dying(flow->ct)))
 366                 return NULL;
 367
 368         return tuplehash;
 369 }
 370 EXPORT_SYMBOL_GPL(flow_offload_lookup);
 371
 372 static int
 373 nf_flow_table_iterate(struct nf_flowtable *flow_table,
 374                       void (*iter)(struct flow_offload *flow, void *data),
 375                       void *data)
 376 {
 377         struct flow_offload_tuple_rhash *tuplehash;
 378         struct rhashtable_iter hti;
 379         struct flow_offload *flow;
 380         int err = 0;
 381
 382         rhashtable_walk_enter(&flow_table->rhashtable, &hti);
 383         rhashtable_walk_start(&hti);
 384
 385         while ((tuplehash = rhashtable_walk_next(&hti))) {
 386                 if (IS_ERR(tuplehash)) {
 387                         if (PTR_ERR(tuplehash) != -EAGAIN) {
 388                                 err = PTR_ERR(tuplehash);
 389                                 break;
 390                         }
 391                         continue;
 392                 }
 393                 if (tuplehash->tuple.dir)
 394                         continue;
 395
 396                 flow = container_of(tuplehash, struct flow_offload, tuplehash[0]);
 397
 398                 iter(flow, data);
 399         }
 400         rhashtable_walk_stop(&hti);
 401         rhashtable_walk_exit(&hti);
 402
 403         return err;
 404 }
 405
 406 static bool flow_offload_stale_dst(struct flow_offload_tuple *tuple)
 407 {
 408         struct dst_entry *dst;
 409
 410         if (tuple->xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
 411             tuple->xmit_type == FLOW_OFFLOAD_XMIT_XFRM) {
 412                 dst = tuple->dst_cache;
 413                 if (!dst_check(dst, tuple->dst_cookie))
 414                         return true;
 415         }
 416
 417         return false;
 418 }
 419
 420 static bool nf_flow_has_stale_dst(struct flow_offload *flow)
 421 {
 422         return flow_offload_stale_dst(&flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple) ||
 423                flow_offload_stale_dst(&flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple);
 424 }
 425
 426 static void nf_flow_offload_gc_step(struct flow_offload *flow, void *data)
 427 {
 428         struct nf_flowtable *flow_table = data;
 429
 430         if (nf_flow_has_expired(flow) ||
 431             nf_ct_is_dying(flow->ct) ||
 432             nf_flow_has_stale_dst(flow))
 433                 set_bit(NF_FLOW_TEARDOWN, &flow->flags);
 434
 435         if (test_bit(NF_FLOW_TEARDOWN, &flow->flags)) {
 436                 if (test_bit(NF_FLOW_HW, &flow->flags)) {
 437                         if (!test_bit(NF_FLOW_HW_DYING, &flow->flags))
 438                                 nf_flow_offload_del(flow_table, flow);
 439                         else if (test_bit(NF_FLOW_HW_DEAD, &flow->flags))
 440                                 flow_offload_del(flow_table, flow);
 441                 } else {
 442                         flow_offload_del(flow_table, flow);
 443                 }
 444         } else if (test_bit(NF_FLOW_HW, &flow->flags)) {
 445                 nf_flow_offload_stats(flow_table, flow);
 446         }
 447 }
 448
 449 static void nf_flow_offload_work_gc(struct work_struct *work)
 450 {
 451         struct nf_flowtable *flow_table;
 452
 453         flow_table = container_of(work, struct nf_flowtable, gc_work.work);
 454         nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
 455         queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ);
 456 }
 457
 458 static void nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff,
 459                                  __be16 port, __be16 new_port)
 460 {
 461         struct tcphdr *tcph;
 462
 463         tcph = (void *)(skb_network_header(skb) + thoff);
 464         inet_proto_csum_replace2(&tcph->check, skb, port, new_port, false);
 465 }
 466
 467 static void nf_flow_nat_port_udp(struct sk_buff *skb, unsigned int thoff,
 468                                  __be16 port, __be16 new_port)
 469 {
 470         struct udphdr *udph;
 471
 472         udph = (void *)(skb_network_header(skb) + thoff);
 473         if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 474                 inet_proto_csum_replace2(&udph->check, skb, port,
 475                                          new_port, false);
 476                 if (!udph->check)
 477                         udph->check = CSUM_MANGLED_0;
 478         }
 479 }
 480
 481 static void nf_flow_nat_port(struct sk_buff *skb, unsigned int thoff,
 482                              u8 protocol, __be16 port, __be16 new_port)
 483 {
 484         switch (protocol) {
 485         case IPPROTO_TCP:
 486                 nf_flow_nat_port_tcp(skb, thoff, port, new_port);
 487                 break;
 488         case IPPROTO_UDP:
 489                 nf_flow_nat_port_udp(skb, thoff, port, new_port);
 490                 break;
 491         }
 492 }
 493
 494 void nf_flow_snat_port(const struct flow_offload *flow,
 495                        struct sk_buff *skb, unsigned int thoff,
 496                        u8 protocol, enum flow_offload_tuple_dir dir)
 497 {
 498         struct flow_ports *hdr;
 499         __be16 port, new_port;
 500
 501         hdr = (void *)(skb_network_header(skb) + thoff);
 502
 503         switch (dir) {
 504         case FLOW_OFFLOAD_DIR_ORIGINAL:
 505                 port = hdr->source;
 506                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port;
 507                 hdr->source = new_port;
 508                 break;
 509         case FLOW_OFFLOAD_DIR_REPLY:
 510                 port = hdr->dest;
 511                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port;
 512                 hdr->dest = new_port;
 513                 break;
 514         }
 515
 516         nf_flow_nat_port(skb, thoff, protocol, port, new_port);
 517 }
 518 EXPORT_SYMBOL_GPL(nf_flow_snat_port);
 519
 520 void nf_flow_dnat_port(const struct flow_offload *flow, struct sk_buff *skb,
 521                        unsigned int thoff, u8 protocol,
 522                        enum flow_offload_tuple_dir dir)
 523 {
 524         struct flow_ports *hdr;
 525         __be16 port, new_port;
 526
 527         hdr = (void *)(skb_network_header(skb) + thoff);
 528
 529         switch (dir) {
 530         case FLOW_OFFLOAD_DIR_ORIGINAL:
 531                 port = hdr->dest;
 532                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port;
 533                 hdr->dest = new_port;
 534                 break;
 535         case FLOW_OFFLOAD_DIR_REPLY:
 536                 port = hdr->source;
 537                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port;
 538                 hdr->source = new_port;
 539                 break;
 540         }
 541
 542         nf_flow_nat_port(skb, thoff, protocol, port, new_port);
 543 }
 544 EXPORT_SYMBOL_GPL(nf_flow_dnat_port);
 545
 546 int nf_flow_table_init(struct nf_flowtable *flowtable)
 547 {
 548         int err;
 549
 550         INIT_DELAYED_WORK(&flowtable->gc_work, nf_flow_offload_work_gc);
 551         flow_block_init(&flowtable->flow_block);
 552         init_rwsem(&flowtable->flow_block_lock);
 553
 554         err = rhashtable_init(&flowtable->rhashtable,
 555                               &nf_flow_offload_rhash_params);
 556         if (err < 0)
 557                 return err;
 558
 559         queue_delayed_work(system_power_efficient_wq,
 560                            &flowtable->gc_work, HZ);
 561
 562         mutex_lock(&flowtable_lock);
 563         list_add(&flowtable->list, &flowtables);
 564         mutex_unlock(&flowtable_lock);
 565
 566         return 0;
 567 }
 568 EXPORT_SYMBOL_GPL(nf_flow_table_init);
 569
 570 static void nf_flow_table_do_cleanup(struct flow_offload *flow, void *data)
 571 {
 572         struct net_device *dev = data;
 573
 574         if (!dev) {
 575                 flow_offload_teardown(flow);
 576                 return;
 577         }
 578
 579         if (net_eq(nf_ct_net(flow->ct), dev_net(dev)) &&
 580             (flow->tuplehash[0].tuple.iifidx == dev->ifindex ||
 581              flow->tuplehash[1].tuple.iifidx == dev->ifindex))
 582                 flow_offload_teardown(flow);
 583 }
 584
 585 void nf_flow_table_gc_cleanup(struct nf_flowtable *flowtable,
 586                               struct net_device *dev)
 587 {
 588         nf_flow_table_iterate(flowtable, nf_flow_table_do_cleanup, dev);
 589         flush_delayed_work(&flowtable->gc_work);
 590         nf_flow_table_offload_flush(flowtable);
 591 }
 592
 593 void nf_flow_table_cleanup(struct net_device *dev)
 594 {
 595         struct nf_flowtable *flowtable;
 596
 597         mutex_lock(&flowtable_lock);
 598         list_for_each_entry(flowtable, &flowtables, list)
 599                 nf_flow_table_gc_cleanup(flowtable, dev);
 600         mutex_unlock(&flowtable_lock);
 601 }
 602 EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);
 603
 604 void nf_flow_table_free(struct nf_flowtable *flow_table)
 605 {
 606         mutex_lock(&flowtable_lock);
 607         list_del(&flow_table->list);
 608         mutex_unlock(&flowtable_lock);
 609
 610         cancel_delayed_work_sync(&flow_table->gc_work);
 611         nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
 612         nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
 613         nf_flow_table_offload_flush(flow_table);
 614         if (nf_flowtable_hw_offload(flow_table))
 615                 nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step,
 616                                       flow_table);
 617         rhashtable_destroy(&flow_table->rhashtable);
 618 }
 619 EXPORT_SYMBOL_GPL(nf_flow_table_free);
 620
 621 static int __init nf_flow_table_module_init(void)
 622 {
 623         return nf_flow_table_offload_init();
 624 }
 625
 626 static void __exit nf_flow_table_module_exit(void)
 627 {
 628         nf_flow_table_offload_exit();
 629 }
 630
 631 module_init(nf_flow_table_module_init);
 632 module_exit(nf_flow_table_module_exit);
 633
 634 MODULE_LICENSE("GPL");
 635 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
 636 MODULE_DESCRIPTION("Netfilter flow table module");