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 static void flow_offload_fixup_ct_timeout(struct nf_conn *ct)
 182 {
 183         const struct nf_conntrack_l4proto *l4proto;
 184         struct net *net = nf_ct_net(ct);
 185         int l4num = nf_ct_protonum(ct);
 186         s32 timeout;
 187
 188         l4proto = nf_ct_l4proto_find(l4num);
 189         if (!l4proto)
 190                 return;
 191
 192         if (l4num == IPPROTO_TCP) {
 193                 struct nf_tcp_net *tn = nf_tcp_pernet(net);
 194
 195                 timeout = tn->timeouts[TCP_CONNTRACK_ESTABLISHED];
 196                 timeout -= tn->offload_timeout;
 197         } else if (l4num == IPPROTO_UDP) {
 198                 struct nf_udp_net *tn = nf_udp_pernet(net);
 199
 200                 timeout = tn->timeouts[UDP_CT_REPLIED];
 201                 timeout -= tn->offload_timeout;
 202         } else {
 203                 return;
 204         }
 205
 206         if (timeout < 0)
 207                 timeout = 0;
 208
 209         if (nf_flow_timeout_delta(ct->timeout) > (__s32)timeout)
 210                 ct->timeout = nfct_time_stamp + timeout;
 211 }
 212
 213 static void flow_offload_fixup_ct_state(struct nf_conn *ct)
 214 {
 215         if (nf_ct_protonum(ct) == IPPROTO_TCP)
 216                 flow_offload_fixup_tcp(&ct->proto.tcp);
 217 }
 218
 219 static void flow_offload_fixup_ct(struct nf_conn *ct)
 220 {
 221         flow_offload_fixup_ct_state(ct);
 222         flow_offload_fixup_ct_timeout(ct);
 223 }
 224
 225 static void flow_offload_route_release(struct flow_offload *flow)
 226 {
 227         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
 228         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_REPLY);
 229 }
 230
 231 void flow_offload_free(struct flow_offload *flow)
 232 {
 233         switch (flow->type) {
 234         case NF_FLOW_OFFLOAD_ROUTE:
 235                 flow_offload_route_release(flow);
 236                 break;
 237         default:
 238                 break;
 239         }
 240         nf_ct_put(flow->ct);
 241         kfree_rcu(flow, rcu_head);
 242 }
 243 EXPORT_SYMBOL_GPL(flow_offload_free);
 244
 245 static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
 246 {
 247         const struct flow_offload_tuple *tuple = data;
 248
 249         return jhash(tuple, offsetof(struct flow_offload_tuple, __hash), seed);
 250 }
 251
 252 static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
 253 {
 254         const struct flow_offload_tuple_rhash *tuplehash = data;
 255
 256         return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, __hash), seed);
 257 }
 258
 259 static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
 260                                         const void *ptr)
 261 {
 262         const struct flow_offload_tuple *tuple = arg->key;
 263         const struct flow_offload_tuple_rhash *x = ptr;
 264
 265         if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, __hash)))
 266                 return 1;
 267
 268         return 0;
 269 }
 270
 271 static const struct rhashtable_params nf_flow_offload_rhash_params = {
 272         .head_offset            = offsetof(struct flow_offload_tuple_rhash, node),
 273         .hashfn                 = flow_offload_hash,
 274         .obj_hashfn             = flow_offload_hash_obj,
 275         .obj_cmpfn              = flow_offload_hash_cmp,
 276         .automatic_shrinking    = true,
 277 };
 278
 279 unsigned long flow_offload_get_timeout(struct flow_offload *flow)
 280 {
 281         const struct nf_conntrack_l4proto *l4proto;
 282         unsigned long timeout = NF_FLOW_TIMEOUT;
 283         struct net *net = nf_ct_net(flow->ct);
 284         int l4num = nf_ct_protonum(flow->ct);
 285
 286         l4proto = nf_ct_l4proto_find(l4num);
 287         if (!l4proto)
 288                 return timeout;
 289
 290         if (l4num == IPPROTO_TCP) {
 291                 struct nf_tcp_net *tn = nf_tcp_pernet(net);
 292
 293                 timeout = tn->offload_timeout;
 294         } else if (l4num == IPPROTO_UDP) {
 295                 struct nf_udp_net *tn = nf_udp_pernet(net);
 296
 297                 timeout = tn->offload_timeout;
 298         }
 299
 300         return timeout;
 301 }
 302
 303 int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow)
 304 {
 305         int err;
 306
 307         flow->timeout = nf_flowtable_time_stamp + flow_offload_get_timeout(flow);
 308
 309         err = rhashtable_insert_fast(&flow_table->rhashtable,
 310                                      &flow->tuplehash[0].node,
 311                                      nf_flow_offload_rhash_params);
 312         if (err < 0)
 313                 return err;
 314
 315         err = rhashtable_insert_fast(&flow_table->rhashtable,
 316                                      &flow->tuplehash[1].node,
 317                                      nf_flow_offload_rhash_params);
 318         if (err < 0) {
 319                 rhashtable_remove_fast(&flow_table->rhashtable,
 320                                        &flow->tuplehash[0].node,
 321                                        nf_flow_offload_rhash_params);
 322                 return err;
 323         }
 324
 325         nf_ct_offload_timeout(flow->ct);
 326
 327         if (nf_flowtable_hw_offload(flow_table)) {
 328                 __set_bit(NF_FLOW_HW, &flow->flags);
 329                 nf_flow_offload_add(flow_table, flow);
 330         }
 331
 332         return 0;
 333 }
 334 EXPORT_SYMBOL_GPL(flow_offload_add);
 335
 336 void flow_offload_refresh(struct nf_flowtable *flow_table,
 337                           struct flow_offload *flow)
 338 {
 339         u32 timeout;
 340
 341         timeout = nf_flowtable_time_stamp + flow_offload_get_timeout(flow);
 342         if (READ_ONCE(flow->timeout) != timeout)
 343                 WRITE_ONCE(flow->timeout, timeout);
 344
 345         if (likely(!nf_flowtable_hw_offload(flow_table)))
 346                 return;
 347
 348         nf_flow_offload_add(flow_table, flow);
 349 }
 350 EXPORT_SYMBOL_GPL(flow_offload_refresh);
 351
 352 static inline bool nf_flow_has_expired(const struct flow_offload *flow)
 353 {
 354         return nf_flow_timeout_delta(flow->timeout) <= 0;
 355 }
 356
 357 static void flow_offload_del(struct nf_flowtable *flow_table,
 358                              struct flow_offload *flow)
 359 {
 360         rhashtable_remove_fast(&flow_table->rhashtable,
 361                                &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
 362                                nf_flow_offload_rhash_params);
 363         rhashtable_remove_fast(&flow_table->rhashtable,
 364                                &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
 365                                nf_flow_offload_rhash_params);
 366
 367         clear_bit(IPS_OFFLOAD_BIT, &flow->ct->status);
 368
 369         if (nf_flow_has_expired(flow))
 370                 flow_offload_fixup_ct(flow->ct);
 371         else
 372                 flow_offload_fixup_ct_timeout(flow->ct);
 373
 374         flow_offload_free(flow);
 375 }
 376
 377 void flow_offload_teardown(struct flow_offload *flow)
 378 {
 379         set_bit(NF_FLOW_TEARDOWN, &flow->flags);
 380
 381         flow_offload_fixup_ct_state(flow->ct);
 382 }
 383 EXPORT_SYMBOL_GPL(flow_offload_teardown);
 384
 385 struct flow_offload_tuple_rhash *
 386 flow_offload_lookup(struct nf_flowtable *flow_table,
 387                     struct flow_offload_tuple *tuple)
 388 {
 389         struct flow_offload_tuple_rhash *tuplehash;
 390         struct flow_offload *flow;
 391         int dir;
 392
 393         tuplehash = rhashtable_lookup(&flow_table->rhashtable, tuple,
 394                                       nf_flow_offload_rhash_params);
 395         if (!tuplehash)
 396                 return NULL;
 397
 398         dir = tuplehash->tuple.dir;
 399         flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
 400         if (test_bit(NF_FLOW_TEARDOWN, &flow->flags))
 401                 return NULL;
 402
 403         if (unlikely(nf_ct_is_dying(flow->ct)))
 404                 return NULL;
 405
 406         return tuplehash;
 407 }
 408 EXPORT_SYMBOL_GPL(flow_offload_lookup);
 409
 410 static int
 411 nf_flow_table_iterate(struct nf_flowtable *flow_table,
 412                       void (*iter)(struct flow_offload *flow, void *data),
 413                       void *data)
 414 {
 415         struct flow_offload_tuple_rhash *tuplehash;
 416         struct rhashtable_iter hti;
 417         struct flow_offload *flow;
 418         int err = 0;
 419
 420         rhashtable_walk_enter(&flow_table->rhashtable, &hti);
 421         rhashtable_walk_start(&hti);
 422
 423         while ((tuplehash = rhashtable_walk_next(&hti))) {
 424                 if (IS_ERR(tuplehash)) {
 425                         if (PTR_ERR(tuplehash) != -EAGAIN) {
 426                                 err = PTR_ERR(tuplehash);
 427                                 break;
 428                         }
 429                         continue;
 430                 }
 431                 if (tuplehash->tuple.dir)
 432                         continue;
 433
 434                 flow = container_of(tuplehash, struct flow_offload, tuplehash[0]);
 435
 436                 iter(flow, data);
 437         }
 438         rhashtable_walk_stop(&hti);
 439         rhashtable_walk_exit(&hti);
 440
 441         return err;
 442 }
 443
 444 static bool flow_offload_stale_dst(struct flow_offload_tuple *tuple)
 445 {
 446         struct dst_entry *dst;
 447
 448         if (tuple->xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
 449             tuple->xmit_type == FLOW_OFFLOAD_XMIT_XFRM) {
 450                 dst = tuple->dst_cache;
 451                 if (!dst_check(dst, tuple->dst_cookie))
 452                         return true;
 453         }
 454
 455         return false;
 456 }
 457
 458 static bool nf_flow_has_stale_dst(struct flow_offload *flow)
 459 {
 460         return flow_offload_stale_dst(&flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple) ||
 461                flow_offload_stale_dst(&flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple);
 462 }
 463
 464 static void nf_flow_offload_gc_step(struct flow_offload *flow, void *data)
 465 {
 466         struct nf_flowtable *flow_table = data;
 467
 468         if (nf_flow_has_expired(flow) ||
 469             nf_ct_is_dying(flow->ct) ||
 470             nf_flow_has_stale_dst(flow))
 471                 set_bit(NF_FLOW_TEARDOWN, &flow->flags);
 472
 473         if (test_bit(NF_FLOW_TEARDOWN, &flow->flags)) {
 474                 if (test_bit(NF_FLOW_HW, &flow->flags)) {
 475                         if (!test_bit(NF_FLOW_HW_DYING, &flow->flags))
 476                                 nf_flow_offload_del(flow_table, flow);
 477                         else if (test_bit(NF_FLOW_HW_DEAD, &flow->flags))
 478                                 flow_offload_del(flow_table, flow);
 479                 } else {
 480                         flow_offload_del(flow_table, flow);
 481                 }
 482         } else if (test_bit(NF_FLOW_HW, &flow->flags)) {
 483                 nf_flow_offload_stats(flow_table, flow);
 484         }
 485 }
 486
 487 static void nf_flow_offload_work_gc(struct work_struct *work)
 488 {
 489         struct nf_flowtable *flow_table;
 490
 491         flow_table = container_of(work, struct nf_flowtable, gc_work.work);
 492         nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
 493         queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ);
 494 }
 495
 496 static void nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff,
 497                                  __be16 port, __be16 new_port)
 498 {
 499         struct tcphdr *tcph;
 500
 501         tcph = (void *)(skb_network_header(skb) + thoff);
 502         inet_proto_csum_replace2(&tcph->check, skb, port, new_port, false);
 503 }
 504
 505 static void nf_flow_nat_port_udp(struct sk_buff *skb, unsigned int thoff,
 506                                  __be16 port, __be16 new_port)
 507 {
 508         struct udphdr *udph;
 509
 510         udph = (void *)(skb_network_header(skb) + thoff);
 511         if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 512                 inet_proto_csum_replace2(&udph->check, skb, port,
 513                                          new_port, false);
 514                 if (!udph->check)
 515                         udph->check = CSUM_MANGLED_0;
 516         }
 517 }
 518
 519 static void nf_flow_nat_port(struct sk_buff *skb, unsigned int thoff,
 520                              u8 protocol, __be16 port, __be16 new_port)
 521 {
 522         switch (protocol) {
 523         case IPPROTO_TCP:
 524                 nf_flow_nat_port_tcp(skb, thoff, port, new_port);
 525                 break;
 526         case IPPROTO_UDP:
 527                 nf_flow_nat_port_udp(skb, thoff, port, new_port);
 528                 break;
 529         }
 530 }
 531
 532 void nf_flow_snat_port(const struct flow_offload *flow,
 533                        struct sk_buff *skb, unsigned int thoff,
 534                        u8 protocol, enum flow_offload_tuple_dir dir)
 535 {
 536         struct flow_ports *hdr;
 537         __be16 port, new_port;
 538
 539         hdr = (void *)(skb_network_header(skb) + thoff);
 540
 541         switch (dir) {
 542         case FLOW_OFFLOAD_DIR_ORIGINAL:
 543                 port = hdr->source;
 544                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port;
 545                 hdr->source = new_port;
 546                 break;
 547         case FLOW_OFFLOAD_DIR_REPLY:
 548                 port = hdr->dest;
 549                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port;
 550                 hdr->dest = new_port;
 551                 break;
 552         }
 553
 554         nf_flow_nat_port(skb, thoff, protocol, port, new_port);
 555 }
 556 EXPORT_SYMBOL_GPL(nf_flow_snat_port);
 557
 558 void nf_flow_dnat_port(const struct flow_offload *flow, struct sk_buff *skb,
 559                        unsigned int thoff, u8 protocol,
 560                        enum flow_offload_tuple_dir dir)
 561 {
 562         struct flow_ports *hdr;
 563         __be16 port, new_port;
 564
 565         hdr = (void *)(skb_network_header(skb) + thoff);
 566
 567         switch (dir) {
 568         case FLOW_OFFLOAD_DIR_ORIGINAL:
 569                 port = hdr->dest;
 570                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port;
 571                 hdr->dest = new_port;
 572                 break;
 573         case FLOW_OFFLOAD_DIR_REPLY:
 574                 port = hdr->source;
 575                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port;
 576                 hdr->source = new_port;
 577                 break;
 578         }
 579
 580         nf_flow_nat_port(skb, thoff, protocol, port, new_port);
 581 }
 582 EXPORT_SYMBOL_GPL(nf_flow_dnat_port);
 583
 584 int nf_flow_table_init(struct nf_flowtable *flowtable)
 585 {
 586         int err;
 587
 588         INIT_DELAYED_WORK(&flowtable->gc_work, nf_flow_offload_work_gc);
 589         flow_block_init(&flowtable->flow_block);
 590         init_rwsem(&flowtable->flow_block_lock);
 591
 592         err = rhashtable_init(&flowtable->rhashtable,
 593                               &nf_flow_offload_rhash_params);
 594         if (err < 0)
 595                 return err;
 596
 597         queue_delayed_work(system_power_efficient_wq,
 598                            &flowtable->gc_work, HZ);
 599
 600         mutex_lock(&flowtable_lock);
 601         list_add(&flowtable->list, &flowtables);
 602         mutex_unlock(&flowtable_lock);
 603
 604         return 0;
 605 }
 606 EXPORT_SYMBOL_GPL(nf_flow_table_init);
 607
 608 static void nf_flow_table_do_cleanup(struct flow_offload *flow, void *data)
 609 {
 610         struct net_device *dev = data;
 611
 612         if (!dev) {
 613                 flow_offload_teardown(flow);
 614                 return;
 615         }
 616
 617         if (net_eq(nf_ct_net(flow->ct), dev_net(dev)) &&
 618             (flow->tuplehash[0].tuple.iifidx == dev->ifindex ||
 619              flow->tuplehash[1].tuple.iifidx == dev->ifindex))
 620                 flow_offload_teardown(flow);
 621 }
 622
 623 void nf_flow_table_gc_cleanup(struct nf_flowtable *flowtable,
 624                               struct net_device *dev)
 625 {
 626         nf_flow_table_iterate(flowtable, nf_flow_table_do_cleanup, dev);
 627         flush_delayed_work(&flowtable->gc_work);
 628         nf_flow_table_offload_flush(flowtable);
 629 }
 630
 631 void nf_flow_table_cleanup(struct net_device *dev)
 632 {
 633         struct nf_flowtable *flowtable;
 634
 635         mutex_lock(&flowtable_lock);
 636         list_for_each_entry(flowtable, &flowtables, list)
 637                 nf_flow_table_gc_cleanup(flowtable, dev);
 638         mutex_unlock(&flowtable_lock);
 639 }
 640 EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);
 641
 642 void nf_flow_table_free(struct nf_flowtable *flow_table)
 643 {
 644         mutex_lock(&flowtable_lock);
 645         list_del(&flow_table->list);
 646         mutex_unlock(&flowtable_lock);
 647
 648         cancel_delayed_work_sync(&flow_table->gc_work);
 649         nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
 650         nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
 651         nf_flow_table_offload_flush(flow_table);
 652         if (nf_flowtable_hw_offload(flow_table))
 653                 nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step,
 654                                       flow_table);
 655         rhashtable_destroy(&flow_table->rhashtable);
 656 }
 657 EXPORT_SYMBOL_GPL(nf_flow_table_free);
 658
 659 static int __init nf_flow_table_module_init(void)
 660 {
 661         return nf_flow_table_offload_init();
 662 }
 663
 664 static void __exit nf_flow_table_module_exit(void)
 665 {
 666         nf_flow_table_offload_exit();
 667 }
 668
 669 module_init(nf_flow_table_module_init);
 670 module_exit(nf_flow_table_module_exit);
 671
 672 MODULE_LICENSE("GPL");
 673 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
 674 MODULE_DESCRIPTION("Netfilter flow table module");