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_maybe_forward(dst, true);
 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 static void flow_offload_fixup_ct_timeout(struct nf_conn *ct)
 182 {
 183         struct net *net = nf_ct_net(ct);
 184         int l4num = nf_ct_protonum(ct);
 185         s32 timeout;
 186
 187         if (l4num == IPPROTO_TCP) {
 188                 struct nf_tcp_net *tn = nf_tcp_pernet(net);
 189
 190                 timeout = tn->timeouts[TCP_CONNTRACK_ESTABLISHED];
 191                 timeout -= tn->offload_timeout;
 192         } else if (l4num == IPPROTO_UDP) {
 193                 struct nf_udp_net *tn = nf_udp_pernet(net);
 194
 195                 timeout = tn->timeouts[UDP_CT_REPLIED];
 196                 timeout -= tn->offload_timeout;
 197         } else {
 198                 return;
 199         }
 200
 201         if (timeout < 0)
 202                 timeout = 0;
 203
 204         if (nf_flow_timeout_delta(ct->timeout) > (__s32)timeout)
 205                 ct->timeout = nfct_time_stamp + timeout;
 206 }
 207
 208 static void flow_offload_fixup_ct_state(struct nf_conn *ct)
 209 {
 210         if (nf_ct_protonum(ct) == IPPROTO_TCP)
 211                 flow_offload_fixup_tcp(&ct->proto.tcp);
 212 }
 213
 214 static void flow_offload_fixup_ct(struct nf_conn *ct)
 215 {
 216         flow_offload_fixup_ct_state(ct);
 217         flow_offload_fixup_ct_timeout(ct);
 218 }
 219
 220 static void flow_offload_route_release(struct flow_offload *flow)
 221 {
 222         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
 223         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_REPLY);
 224 }
 225
 226 void flow_offload_free(struct flow_offload *flow)
 227 {
 228         switch (flow->type) {
 229         case NF_FLOW_OFFLOAD_ROUTE:
 230                 flow_offload_route_release(flow);
 231                 break;
 232         default:
 233                 break;
 234         }
 235         nf_ct_put(flow->ct);
 236         kfree_rcu(flow, rcu_head);
 237 }
 238 EXPORT_SYMBOL_GPL(flow_offload_free);
 239
 240 static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
 241 {
 242         const struct flow_offload_tuple *tuple = data;
 243
 244         return jhash(tuple, offsetof(struct flow_offload_tuple, __hash), seed);
 245 }
 246
 247 static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
 248 {
 249         const struct flow_offload_tuple_rhash *tuplehash = data;
 250
 251         return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, __hash), seed);
 252 }
 253
 254 static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
 255                                         const void *ptr)
 256 {
 257         const struct flow_offload_tuple *tuple = arg->key;
 258         const struct flow_offload_tuple_rhash *x = ptr;
 259
 260         if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, __hash)))
 261                 return 1;
 262
 263         return 0;
 264 }
 265
 266 static const struct rhashtable_params nf_flow_offload_rhash_params = {
 267         .head_offset            = offsetof(struct flow_offload_tuple_rhash, node),
 268         .hashfn                 = flow_offload_hash,
 269         .obj_hashfn             = flow_offload_hash_obj,
 270         .obj_cmpfn              = flow_offload_hash_cmp,
 271         .automatic_shrinking    = true,
 272 };
 273
 274 unsigned long flow_offload_get_timeout(struct flow_offload *flow)
 275 {
 276         unsigned long timeout = NF_FLOW_TIMEOUT;
 277         struct net *net = nf_ct_net(flow->ct);
 278         int l4num = nf_ct_protonum(flow->ct);
 279
 280         if (l4num == IPPROTO_TCP) {
 281                 struct nf_tcp_net *tn = nf_tcp_pernet(net);
 282
 283                 timeout = tn->offload_timeout;
 284         } else if (l4num == IPPROTO_UDP) {
 285                 struct nf_udp_net *tn = nf_udp_pernet(net);
 286
 287                 timeout = tn->offload_timeout;
 288         }
 289
 290         return timeout;
 291 }
 292
 293 int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow)
 294 {
 295         int err;
 296
 297         flow->timeout = nf_flowtable_time_stamp + flow_offload_get_timeout(flow);
 298
 299         err = rhashtable_insert_fast(&flow_table->rhashtable,
 300                                      &flow->tuplehash[0].node,
 301                                      nf_flow_offload_rhash_params);
 302         if (err < 0)
 303                 return err;
 304
 305         err = rhashtable_insert_fast(&flow_table->rhashtable,
 306                                      &flow->tuplehash[1].node,
 307                                      nf_flow_offload_rhash_params);
 308         if (err < 0) {
 309                 rhashtable_remove_fast(&flow_table->rhashtable,
 310                                        &flow->tuplehash[0].node,
 311                                        nf_flow_offload_rhash_params);
 312                 return err;
 313         }
 314
 315         nf_ct_offload_timeout(flow->ct);
 316
 317         if (nf_flowtable_hw_offload(flow_table)) {
 318                 __set_bit(NF_FLOW_HW, &flow->flags);
 319                 nf_flow_offload_add(flow_table, flow);
 320         }
 321
 322         return 0;
 323 }
 324 EXPORT_SYMBOL_GPL(flow_offload_add);
 325
 326 void flow_offload_refresh(struct nf_flowtable *flow_table,
 327                           struct flow_offload *flow)
 328 {
 329         u32 timeout;
 330
 331         timeout = nf_flowtable_time_stamp + flow_offload_get_timeout(flow);
 332         if (READ_ONCE(flow->timeout) != timeout)
 333                 WRITE_ONCE(flow->timeout, timeout);
 334
 335         if (likely(!nf_flowtable_hw_offload(flow_table)))
 336                 return;
 337
 338         nf_flow_offload_add(flow_table, flow);
 339 }
 340 EXPORT_SYMBOL_GPL(flow_offload_refresh);
 341
 342 static inline bool nf_flow_has_expired(const struct flow_offload *flow)
 343 {
 344         return nf_flow_timeout_delta(flow->timeout) <= 0;
 345 }
 346
 347 static void flow_offload_del(struct nf_flowtable *flow_table,
 348                              struct flow_offload *flow)
 349 {
 350         rhashtable_remove_fast(&flow_table->rhashtable,
 351                                &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
 352                                nf_flow_offload_rhash_params);
 353         rhashtable_remove_fast(&flow_table->rhashtable,
 354                                &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
 355                                nf_flow_offload_rhash_params);
 356
 357         clear_bit(IPS_OFFLOAD_BIT, &flow->ct->status);
 358
 359         if (nf_flow_has_expired(flow))
 360                 flow_offload_fixup_ct(flow->ct);
 361         else
 362                 flow_offload_fixup_ct_timeout(flow->ct);
 363
 364         flow_offload_free(flow);
 365 }
 366
 367 void flow_offload_teardown(struct flow_offload *flow)
 368 {
 369         set_bit(NF_FLOW_TEARDOWN, &flow->flags);
 370
 371         flow_offload_fixup_ct_state(flow->ct);
 372 }
 373 EXPORT_SYMBOL_GPL(flow_offload_teardown);
 374
 375 struct flow_offload_tuple_rhash *
 376 flow_offload_lookup(struct nf_flowtable *flow_table,
 377                     struct flow_offload_tuple *tuple)
 378 {
 379         struct flow_offload_tuple_rhash *tuplehash;
 380         struct flow_offload *flow;
 381         int dir;
 382
 383         tuplehash = rhashtable_lookup(&flow_table->rhashtable, tuple,
 384                                       nf_flow_offload_rhash_params);
 385         if (!tuplehash)
 386                 return NULL;
 387
 388         dir = tuplehash->tuple.dir;
 389         flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
 390         if (test_bit(NF_FLOW_TEARDOWN, &flow->flags))
 391                 return NULL;
 392
 393         if (unlikely(nf_ct_is_dying(flow->ct)))
 394                 return NULL;
 395
 396         return tuplehash;
 397 }
 398 EXPORT_SYMBOL_GPL(flow_offload_lookup);
 399
 400 static int
 401 nf_flow_table_iterate(struct nf_flowtable *flow_table,
 402                       void (*iter)(struct flow_offload *flow, void *data),
 403                       void *data)
 404 {
 405         struct flow_offload_tuple_rhash *tuplehash;
 406         struct rhashtable_iter hti;
 407         struct flow_offload *flow;
 408         int err = 0;
 409
 410         rhashtable_walk_enter(&flow_table->rhashtable, &hti);
 411         rhashtable_walk_start(&hti);
 412
 413         while ((tuplehash = rhashtable_walk_next(&hti))) {
 414                 if (IS_ERR(tuplehash)) {
 415                         if (PTR_ERR(tuplehash) != -EAGAIN) {
 416                                 err = PTR_ERR(tuplehash);
 417                                 break;
 418                         }
 419                         continue;
 420                 }
 421                 if (tuplehash->tuple.dir)
 422                         continue;
 423
 424                 flow = container_of(tuplehash, struct flow_offload, tuplehash[0]);
 425
 426                 iter(flow, data);
 427         }
 428         rhashtable_walk_stop(&hti);
 429         rhashtable_walk_exit(&hti);
 430
 431         return err;
 432 }
 433
 434 static bool flow_offload_stale_dst(struct flow_offload_tuple *tuple)
 435 {
 436         struct dst_entry *dst;
 437
 438         if (tuple->xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
 439             tuple->xmit_type == FLOW_OFFLOAD_XMIT_XFRM) {
 440                 dst = tuple->dst_cache;
 441                 if (!dst_check(dst, tuple->dst_cookie))
 442                         return true;
 443         }
 444
 445         return false;
 446 }
 447
 448 static bool nf_flow_has_stale_dst(struct flow_offload *flow)
 449 {
 450         return flow_offload_stale_dst(&flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple) ||
 451                flow_offload_stale_dst(&flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple);
 452 }
 453
 454 static void nf_flow_offload_gc_step(struct flow_offload *flow, void *data)
 455 {
 456         struct nf_flowtable *flow_table = data;
 457
 458         if (nf_flow_has_expired(flow) ||
 459             nf_ct_is_dying(flow->ct) ||
 460             nf_flow_has_stale_dst(flow))
 461                 set_bit(NF_FLOW_TEARDOWN, &flow->flags);
 462
 463         if (test_bit(NF_FLOW_TEARDOWN, &flow->flags)) {
 464                 if (test_bit(NF_FLOW_HW, &flow->flags)) {
 465                         if (!test_bit(NF_FLOW_HW_DYING, &flow->flags))
 466                                 nf_flow_offload_del(flow_table, flow);
 467                         else if (test_bit(NF_FLOW_HW_DEAD, &flow->flags))
 468                                 flow_offload_del(flow_table, flow);
 469                 } else {
 470                         flow_offload_del(flow_table, flow);
 471                 }
 472         } else if (test_bit(NF_FLOW_HW, &flow->flags)) {
 473                 nf_flow_offload_stats(flow_table, flow);
 474         }
 475 }
 476
 477 static void nf_flow_offload_work_gc(struct work_struct *work)
 478 {
 479         struct nf_flowtable *flow_table;
 480
 481         flow_table = container_of(work, struct nf_flowtable, gc_work.work);
 482         nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
 483         queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ);
 484 }
 485
 486 static void nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff,
 487                                  __be16 port, __be16 new_port)
 488 {
 489         struct tcphdr *tcph;
 490
 491         tcph = (void *)(skb_network_header(skb) + thoff);
 492         inet_proto_csum_replace2(&tcph->check, skb, port, new_port, false);
 493 }
 494
 495 static void nf_flow_nat_port_udp(struct sk_buff *skb, unsigned int thoff,
 496                                  __be16 port, __be16 new_port)
 497 {
 498         struct udphdr *udph;
 499
 500         udph = (void *)(skb_network_header(skb) + thoff);
 501         if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 502                 inet_proto_csum_replace2(&udph->check, skb, port,
 503                                          new_port, false);
 504                 if (!udph->check)
 505                         udph->check = CSUM_MANGLED_0;
 506         }
 507 }
 508
 509 static void nf_flow_nat_port(struct sk_buff *skb, unsigned int thoff,
 510                              u8 protocol, __be16 port, __be16 new_port)
 511 {
 512         switch (protocol) {
 513         case IPPROTO_TCP:
 514                 nf_flow_nat_port_tcp(skb, thoff, port, new_port);
 515                 break;
 516         case IPPROTO_UDP:
 517                 nf_flow_nat_port_udp(skb, thoff, port, new_port);
 518                 break;
 519         }
 520 }
 521
 522 void nf_flow_snat_port(const struct flow_offload *flow,
 523                        struct sk_buff *skb, unsigned int thoff,
 524                        u8 protocol, 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->source;
 534                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port;
 535                 hdr->source = new_port;
 536                 break;
 537         case FLOW_OFFLOAD_DIR_REPLY:
 538                 port = hdr->dest;
 539                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port;
 540                 hdr->dest = new_port;
 541                 break;
 542         }
 543
 544         nf_flow_nat_port(skb, thoff, protocol, port, new_port);
 545 }
 546 EXPORT_SYMBOL_GPL(nf_flow_snat_port);
 547
 548 void nf_flow_dnat_port(const struct flow_offload *flow, struct sk_buff *skb,
 549                        unsigned int thoff, u8 protocol,
 550                        enum flow_offload_tuple_dir dir)
 551 {
 552         struct flow_ports *hdr;
 553         __be16 port, new_port;
 554
 555         hdr = (void *)(skb_network_header(skb) + thoff);
 556
 557         switch (dir) {
 558         case FLOW_OFFLOAD_DIR_ORIGINAL:
 559                 port = hdr->dest;
 560                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port;
 561                 hdr->dest = new_port;
 562                 break;
 563         case FLOW_OFFLOAD_DIR_REPLY:
 564                 port = hdr->source;
 565                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port;
 566                 hdr->source = new_port;
 567                 break;
 568         }
 569
 570         nf_flow_nat_port(skb, thoff, protocol, port, new_port);
 571 }
 572 EXPORT_SYMBOL_GPL(nf_flow_dnat_port);
 573
 574 int nf_flow_table_init(struct nf_flowtable *flowtable)
 575 {
 576         int err;
 577
 578         INIT_DELAYED_WORK(&flowtable->gc_work, nf_flow_offload_work_gc);
 579         flow_block_init(&flowtable->flow_block);
 580         init_rwsem(&flowtable->flow_block_lock);
 581
 582         err = rhashtable_init(&flowtable->rhashtable,
 583                               &nf_flow_offload_rhash_params);
 584         if (err < 0)
 585                 return err;
 586
 587         queue_delayed_work(system_power_efficient_wq,
 588                            &flowtable->gc_work, HZ);
 589
 590         mutex_lock(&flowtable_lock);
 591         list_add(&flowtable->list, &flowtables);
 592         mutex_unlock(&flowtable_lock);
 593
 594         return 0;
 595 }
 596 EXPORT_SYMBOL_GPL(nf_flow_table_init);
 597
 598 static void nf_flow_table_do_cleanup(struct flow_offload *flow, void *data)
 599 {
 600         struct net_device *dev = data;
 601
 602         if (!dev) {
 603                 flow_offload_teardown(flow);
 604                 return;
 605         }
 606
 607         if (net_eq(nf_ct_net(flow->ct), dev_net(dev)) &&
 608             (flow->tuplehash[0].tuple.iifidx == dev->ifindex ||
 609              flow->tuplehash[1].tuple.iifidx == dev->ifindex))
 610                 flow_offload_teardown(flow);
 611 }
 612
 613 void nf_flow_table_gc_cleanup(struct nf_flowtable *flowtable,
 614                               struct net_device *dev)
 615 {
 616         nf_flow_table_iterate(flowtable, nf_flow_table_do_cleanup, dev);
 617         flush_delayed_work(&flowtable->gc_work);
 618         nf_flow_table_offload_flush(flowtable);
 619 }
 620
 621 void nf_flow_table_cleanup(struct net_device *dev)
 622 {
 623         struct nf_flowtable *flowtable;
 624
 625         mutex_lock(&flowtable_lock);
 626         list_for_each_entry(flowtable, &flowtables, list)
 627                 nf_flow_table_gc_cleanup(flowtable, dev);
 628         mutex_unlock(&flowtable_lock);
 629 }
 630 EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);
 631
 632 void nf_flow_table_free(struct nf_flowtable *flow_table)
 633 {
 634         mutex_lock(&flowtable_lock);
 635         list_del(&flow_table->list);
 636         mutex_unlock(&flowtable_lock);
 637
 638         cancel_delayed_work_sync(&flow_table->gc_work);
 639         nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
 640         nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
 641         nf_flow_table_offload_flush(flow_table);
 642         if (nf_flowtable_hw_offload(flow_table))
 643                 nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step,
 644                                       flow_table);
 645         rhashtable_destroy(&flow_table->rhashtable);
 646 }
 647 EXPORT_SYMBOL_GPL(nf_flow_table_free);
 648
 649 static int __init nf_flow_table_module_init(void)
 650 {
 651         return nf_flow_table_offload_init();
 652 }
 653
 654 static void __exit nf_flow_table_module_exit(void)
 655 {
 656         nf_flow_table_offload_exit();
 657 }
 658
 659 module_init(nf_flow_table_module_init);
 660 module_exit(nf_flow_table_module_exit);
 661
 662 MODULE_LICENSE("GPL");
 663 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
 664 MODULE_DESCRIPTION("Netfilter flow table module");