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                    !test_and_clear_bit(NF_FLOW_HW_REFRESH, &flow->flags)))
 311                 return;
 312
 313         nf_flow_offload_add(flow_table, flow);
 314 }
 315 EXPORT_SYMBOL_GPL(flow_offload_refresh);
 316
 317 static inline bool nf_flow_has_expired(const struct flow_offload *flow)
 318 {
 319         return nf_flow_timeout_delta(flow->timeout) <= 0;
 320 }
 321
 322 static void flow_offload_del(struct nf_flowtable *flow_table,
 323                              struct flow_offload *flow)
 324 {
 325         rhashtable_remove_fast(&flow_table->rhashtable,
 326                                &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
 327                                nf_flow_offload_rhash_params);
 328         rhashtable_remove_fast(&flow_table->rhashtable,
 329                                &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
 330                                nf_flow_offload_rhash_params);
 331
 332         clear_bit(IPS_OFFLOAD_BIT, &flow->ct->status);
 333
 334         if (nf_flow_has_expired(flow))
 335                 flow_offload_fixup_ct(flow->ct);
 336         else
 337                 flow_offload_fixup_ct_timeout(flow->ct);
 338
 339         flow_offload_free(flow);
 340 }
 341
 342 void flow_offload_teardown(struct flow_offload *flow)
 343 {
 344         set_bit(NF_FLOW_TEARDOWN, &flow->flags);
 345
 346         flow_offload_fixup_ct_state(flow->ct);
 347 }
 348 EXPORT_SYMBOL_GPL(flow_offload_teardown);
 349
 350 struct flow_offload_tuple_rhash *
 351 flow_offload_lookup(struct nf_flowtable *flow_table,
 352                     struct flow_offload_tuple *tuple)
 353 {
 354         struct flow_offload_tuple_rhash *tuplehash;
 355         struct flow_offload *flow;
 356         int dir;
 357
 358         tuplehash = rhashtable_lookup(&flow_table->rhashtable, tuple,
 359                                       nf_flow_offload_rhash_params);
 360         if (!tuplehash)
 361                 return NULL;
 362
 363         dir = tuplehash->tuple.dir;
 364         flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
 365         if (test_bit(NF_FLOW_TEARDOWN, &flow->flags))
 366                 return NULL;
 367
 368         if (unlikely(nf_ct_is_dying(flow->ct)))
 369                 return NULL;
 370
 371         return tuplehash;
 372 }
 373 EXPORT_SYMBOL_GPL(flow_offload_lookup);
 374
 375 static int
 376 nf_flow_table_iterate(struct nf_flowtable *flow_table,
 377                       void (*iter)(struct flow_offload *flow, void *data),
 378                       void *data)
 379 {
 380         struct flow_offload_tuple_rhash *tuplehash;
 381         struct rhashtable_iter hti;
 382         struct flow_offload *flow;
 383         int err = 0;
 384
 385         rhashtable_walk_enter(&flow_table->rhashtable, &hti);
 386         rhashtable_walk_start(&hti);
 387
 388         while ((tuplehash = rhashtable_walk_next(&hti))) {
 389                 if (IS_ERR(tuplehash)) {
 390                         if (PTR_ERR(tuplehash) != -EAGAIN) {
 391                                 err = PTR_ERR(tuplehash);
 392                                 break;
 393                         }
 394                         continue;
 395                 }
 396                 if (tuplehash->tuple.dir)
 397                         continue;
 398
 399                 flow = container_of(tuplehash, struct flow_offload, tuplehash[0]);
 400
 401                 iter(flow, data);
 402         }
 403         rhashtable_walk_stop(&hti);
 404         rhashtable_walk_exit(&hti);
 405
 406         return err;
 407 }
 408
 409 static bool flow_offload_stale_dst(struct flow_offload_tuple *tuple)
 410 {
 411         struct dst_entry *dst;
 412
 413         if (tuple->xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
 414             tuple->xmit_type == FLOW_OFFLOAD_XMIT_XFRM) {
 415                 dst = tuple->dst_cache;
 416                 if (!dst_check(dst, tuple->dst_cookie))
 417                         return true;
 418         }
 419
 420         return false;
 421 }
 422
 423 static bool nf_flow_has_stale_dst(struct flow_offload *flow)
 424 {
 425         return flow_offload_stale_dst(&flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple) ||
 426                flow_offload_stale_dst(&flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple);
 427 }
 428
 429 static void nf_flow_offload_gc_step(struct flow_offload *flow, void *data)
 430 {
 431         struct nf_flowtable *flow_table = data;
 432
 433         if (nf_flow_has_expired(flow) ||
 434             nf_ct_is_dying(flow->ct) ||
 435             nf_flow_has_stale_dst(flow))
 436                 set_bit(NF_FLOW_TEARDOWN, &flow->flags);
 437
 438         if (test_bit(NF_FLOW_TEARDOWN, &flow->flags)) {
 439                 if (test_bit(NF_FLOW_HW, &flow->flags)) {
 440                         if (!test_bit(NF_FLOW_HW_DYING, &flow->flags))
 441                                 nf_flow_offload_del(flow_table, flow);
 442                         else if (test_bit(NF_FLOW_HW_DEAD, &flow->flags))
 443                                 flow_offload_del(flow_table, flow);
 444                 } else {
 445                         flow_offload_del(flow_table, flow);
 446                 }
 447         } else if (test_bit(NF_FLOW_HW, &flow->flags)) {
 448                 nf_flow_offload_stats(flow_table, flow);
 449         }
 450 }
 451
 452 static void nf_flow_offload_work_gc(struct work_struct *work)
 453 {
 454         struct nf_flowtable *flow_table;
 455
 456         flow_table = container_of(work, struct nf_flowtable, gc_work.work);
 457         nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
 458         queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ);
 459 }
 460
 461 static void nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff,
 462                                  __be16 port, __be16 new_port)
 463 {
 464         struct tcphdr *tcph;
 465
 466         tcph = (void *)(skb_network_header(skb) + thoff);
 467         inet_proto_csum_replace2(&tcph->check, skb, port, new_port, false);
 468 }
 469
 470 static void nf_flow_nat_port_udp(struct sk_buff *skb, unsigned int thoff,
 471                                  __be16 port, __be16 new_port)
 472 {
 473         struct udphdr *udph;
 474
 475         udph = (void *)(skb_network_header(skb) + thoff);
 476         if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 477                 inet_proto_csum_replace2(&udph->check, skb, port,
 478                                          new_port, false);
 479                 if (!udph->check)
 480                         udph->check = CSUM_MANGLED_0;
 481         }
 482 }
 483
 484 static void nf_flow_nat_port(struct sk_buff *skb, unsigned int thoff,
 485                              u8 protocol, __be16 port, __be16 new_port)
 486 {
 487         switch (protocol) {
 488         case IPPROTO_TCP:
 489                 nf_flow_nat_port_tcp(skb, thoff, port, new_port);
 490                 break;
 491         case IPPROTO_UDP:
 492                 nf_flow_nat_port_udp(skb, thoff, port, new_port);
 493                 break;
 494         }
 495 }
 496
 497 void nf_flow_snat_port(const struct flow_offload *flow,
 498                        struct sk_buff *skb, unsigned int thoff,
 499                        u8 protocol, enum flow_offload_tuple_dir dir)
 500 {
 501         struct flow_ports *hdr;
 502         __be16 port, new_port;
 503
 504         hdr = (void *)(skb_network_header(skb) + thoff);
 505
 506         switch (dir) {
 507         case FLOW_OFFLOAD_DIR_ORIGINAL:
 508                 port = hdr->source;
 509                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port;
 510                 hdr->source = new_port;
 511                 break;
 512         case FLOW_OFFLOAD_DIR_REPLY:
 513                 port = hdr->dest;
 514                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port;
 515                 hdr->dest = new_port;
 516                 break;
 517         }
 518
 519         nf_flow_nat_port(skb, thoff, protocol, port, new_port);
 520 }
 521 EXPORT_SYMBOL_GPL(nf_flow_snat_port);
 522
 523 void nf_flow_dnat_port(const struct flow_offload *flow, struct sk_buff *skb,
 524                        unsigned int thoff, u8 protocol,
 525                        enum flow_offload_tuple_dir dir)
 526 {
 527         struct flow_ports *hdr;
 528         __be16 port, new_port;
 529
 530         hdr = (void *)(skb_network_header(skb) + thoff);
 531
 532         switch (dir) {
 533         case FLOW_OFFLOAD_DIR_ORIGINAL:
 534                 port = hdr->dest;
 535                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port;
 536                 hdr->dest = new_port;
 537                 break;
 538         case FLOW_OFFLOAD_DIR_REPLY:
 539                 port = hdr->source;
 540                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port;
 541                 hdr->source = new_port;
 542                 break;
 543         }
 544
 545         nf_flow_nat_port(skb, thoff, protocol, port, new_port);
 546 }
 547 EXPORT_SYMBOL_GPL(nf_flow_dnat_port);
 548
 549 int nf_flow_table_init(struct nf_flowtable *flowtable)
 550 {
 551         int err;
 552
 553         INIT_DELAYED_WORK(&flowtable->gc_work, nf_flow_offload_work_gc);
 554         flow_block_init(&flowtable->flow_block);
 555         init_rwsem(&flowtable->flow_block_lock);
 556
 557         err = rhashtable_init(&flowtable->rhashtable,
 558                               &nf_flow_offload_rhash_params);
 559         if (err < 0)
 560                 return err;
 561
 562         queue_delayed_work(system_power_efficient_wq,
 563                            &flowtable->gc_work, HZ);
 564
 565         mutex_lock(&flowtable_lock);
 566         list_add(&flowtable->list, &flowtables);
 567         mutex_unlock(&flowtable_lock);
 568
 569         return 0;
 570 }
 571 EXPORT_SYMBOL_GPL(nf_flow_table_init);
 572
 573 static void nf_flow_table_do_cleanup(struct flow_offload *flow, void *data)
 574 {
 575         struct net_device *dev = data;
 576
 577         if (!dev) {
 578                 flow_offload_teardown(flow);
 579                 return;
 580         }
 581
 582         if (net_eq(nf_ct_net(flow->ct), dev_net(dev)) &&
 583             (flow->tuplehash[0].tuple.iifidx == dev->ifindex ||
 584              flow->tuplehash[1].tuple.iifidx == dev->ifindex))
 585                 flow_offload_teardown(flow);
 586 }
 587
 588 void nf_flow_table_gc_cleanup(struct nf_flowtable *flowtable,
 589                               struct net_device *dev)
 590 {
 591         nf_flow_table_iterate(flowtable, nf_flow_table_do_cleanup, dev);
 592         flush_delayed_work(&flowtable->gc_work);
 593         nf_flow_table_offload_flush(flowtable);
 594 }
 595
 596 void nf_flow_table_cleanup(struct net_device *dev)
 597 {
 598         struct nf_flowtable *flowtable;
 599
 600         mutex_lock(&flowtable_lock);
 601         list_for_each_entry(flowtable, &flowtables, list)
 602                 nf_flow_table_gc_cleanup(flowtable, dev);
 603         mutex_unlock(&flowtable_lock);
 604 }
 605 EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);
 606
 607 void nf_flow_table_free(struct nf_flowtable *flow_table)
 608 {
 609         mutex_lock(&flowtable_lock);
 610         list_del(&flow_table->list);
 611         mutex_unlock(&flowtable_lock);
 612
 613         cancel_delayed_work_sync(&flow_table->gc_work);
 614         nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
 615         nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
 616         nf_flow_table_offload_flush(flow_table);
 617         if (nf_flowtable_hw_offload(flow_table))
 618                 nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step,
 619                                       flow_table);
 620         rhashtable_destroy(&flow_table->rhashtable);
 621 }
 622 EXPORT_SYMBOL_GPL(nf_flow_table_free);
 623
 624 static int __init nf_flow_table_module_init(void)
 625 {
 626         return nf_flow_table_offload_init();
 627 }
 628
 629 static void __exit nf_flow_table_module_exit(void)
 630 {
 631         nf_flow_table_offload_exit();
 632 }
 633
 634 module_init(nf_flow_table_module_init);
 635 module_exit(nf_flow_table_module_exit);
 636
 637 MODULE_LICENSE("GPL");
 638 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
 639 MODULE_DESCRIPTION("Netfilter flow table module");