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
  43         switch (ctt->dst.protonum) {
  44         case IPPROTO_TCP:
  45         case IPPROTO_UDP:
  46                 ft->src_port = ctt->src.u.tcp.port;
  47                 ft->dst_port = ctt->dst.u.tcp.port;
  48                 break;
  49         }
  50 }
  51
  52 struct flow_offload *flow_offload_alloc(struct nf_conn *ct)
  53 {
  54         struct flow_offload *flow;
  55
  56         if (unlikely(nf_ct_is_dying(ct) ||
  57             !refcount_inc_not_zero(&ct->ct_general.use)))
  58                 return NULL;
  59
  60         flow = kzalloc(sizeof(*flow), GFP_ATOMIC);
  61         if (!flow)
  62                 goto err_ct_refcnt;
  63
  64         flow->ct = ct;
  65
  66         flow_offload_fill_dir(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
  67         flow_offload_fill_dir(flow, FLOW_OFFLOAD_DIR_REPLY);
  68
  69         if (ct->status & IPS_SRC_NAT)
  70                 __set_bit(NF_FLOW_SNAT, &flow->flags);
  71         if (ct->status & IPS_DST_NAT)
  72                 __set_bit(NF_FLOW_DNAT, &flow->flags);
  73
  74         return flow;
  75
  76 err_ct_refcnt:
  77         nf_ct_put(ct);
  78
  79         return NULL;
  80 }
  81 EXPORT_SYMBOL_GPL(flow_offload_alloc);
  82
  83 static u32 flow_offload_dst_cookie(struct flow_offload_tuple *flow_tuple)
  84 {
  85         const struct rt6_info *rt;
  86
  87         if (flow_tuple->l3proto == NFPROTO_IPV6) {
  88                 rt = (const struct rt6_info *)flow_tuple->dst_cache;
  89                 return rt6_get_cookie(rt);
  90         }
  91
  92         return 0;
  93 }
  94
  95 static int flow_offload_fill_route(struct flow_offload *flow,
  96                                    const struct nf_flow_route *route,
  97                                    enum flow_offload_tuple_dir dir)
  98 {
  99         struct flow_offload_tuple *flow_tuple = &flow->tuplehash[dir].tuple;
 100         struct dst_entry *dst = route->tuple[dir].dst;
 101         int i, j = 0;
 102
 103         switch (flow_tuple->l3proto) {
 104         case NFPROTO_IPV4:
 105                 flow_tuple->mtu = ip_dst_mtu_maybe_forward(dst, true);
 106                 break;
 107         case NFPROTO_IPV6:
 108                 flow_tuple->mtu = ip6_dst_mtu_maybe_forward(dst, true);
 109                 break;
 110         }
 111
 112         flow_tuple->iifidx = route->tuple[dir].in.ifindex;
 113         for (i = route->tuple[dir].in.num_encaps - 1; i >= 0; i--) {
 114                 flow_tuple->encap[j].id = route->tuple[dir].in.encap[i].id;
 115                 flow_tuple->encap[j].proto = route->tuple[dir].in.encap[i].proto;
 116                 if (route->tuple[dir].in.ingress_vlans & BIT(i))
 117                         flow_tuple->in_vlan_ingress |= BIT(j);
 118                 j++;
 119         }
 120         flow_tuple->encap_num = route->tuple[dir].in.num_encaps;
 121
 122         switch (route->tuple[dir].xmit_type) {
 123         case FLOW_OFFLOAD_XMIT_DIRECT:
 124                 memcpy(flow_tuple->out.h_dest, route->tuple[dir].out.h_dest,
 125                        ETH_ALEN);
 126                 memcpy(flow_tuple->out.h_source, route->tuple[dir].out.h_source,
 127                        ETH_ALEN);
 128                 flow_tuple->out.ifidx = route->tuple[dir].out.ifindex;
 129                 flow_tuple->out.hw_ifidx = route->tuple[dir].out.hw_ifindex;
 130                 break;
 131         case FLOW_OFFLOAD_XMIT_XFRM:
 132         case FLOW_OFFLOAD_XMIT_NEIGH:
 133                 if (!dst_hold_safe(route->tuple[dir].dst))
 134                         return -1;
 135
 136                 flow_tuple->dst_cache = dst;
 137                 flow_tuple->dst_cookie = flow_offload_dst_cookie(flow_tuple);
 138                 break;
 139         default:
 140                 WARN_ON_ONCE(1);
 141                 break;
 142         }
 143         flow_tuple->xmit_type = route->tuple[dir].xmit_type;
 144
 145         return 0;
 146 }
 147
 148 static void nft_flow_dst_release(struct flow_offload *flow,
 149                                  enum flow_offload_tuple_dir dir)
 150 {
 151         if (flow->tuplehash[dir].tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
 152             flow->tuplehash[dir].tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)
 153                 dst_release(flow->tuplehash[dir].tuple.dst_cache);
 154 }
 155
 156 int flow_offload_route_init(struct flow_offload *flow,
 157                             const struct nf_flow_route *route)
 158 {
 159         int err;
 160
 161         err = flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_ORIGINAL);
 162         if (err < 0)
 163                 return err;
 164
 165         err = flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_REPLY);
 166         if (err < 0)
 167                 goto err_route_reply;
 168
 169         flow->type = NF_FLOW_OFFLOAD_ROUTE;
 170
 171         return 0;
 172
 173 err_route_reply:
 174         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
 175
 176         return err;
 177 }
 178 EXPORT_SYMBOL_GPL(flow_offload_route_init);
 179
 180 static void flow_offload_fixup_tcp(struct ip_ct_tcp *tcp)
 181 {
 182         tcp->state = TCP_CONNTRACK_ESTABLISHED;
 183         tcp->seen[0].td_maxwin = 0;
 184         tcp->seen[1].td_maxwin = 0;
 185 }
 186
 187 static void flow_offload_fixup_ct_timeout(struct nf_conn *ct)
 188 {
 189         struct net *net = nf_ct_net(ct);
 190         int l4num = nf_ct_protonum(ct);
 191         s32 timeout;
 192
 193         if (l4num == IPPROTO_TCP) {
 194                 struct nf_tcp_net *tn = nf_tcp_pernet(net);
 195
 196                 timeout = tn->timeouts[TCP_CONNTRACK_ESTABLISHED];
 197                 timeout -= tn->offload_timeout;
 198         } else if (l4num == IPPROTO_UDP) {
 199                 struct nf_udp_net *tn = nf_udp_pernet(net);
 200
 201                 timeout = tn->timeouts[UDP_CT_REPLIED];
 202                 timeout -= tn->offload_timeout;
 203         } else {
 204                 return;
 205         }
 206
 207         if (timeout < 0)
 208                 timeout = 0;
 209
 210         if (nf_flow_timeout_delta(READ_ONCE(ct->timeout)) > (__s32)timeout)
 211                 WRITE_ONCE(ct->timeout, nfct_time_stamp + timeout);
 212 }
 213
 214 static void flow_offload_fixup_ct_state(struct nf_conn *ct)
 215 {
 216         if (nf_ct_protonum(ct) == IPPROTO_TCP)
 217                 flow_offload_fixup_tcp(&ct->proto.tcp);
 218 }
 219
 220 static void flow_offload_fixup_ct(struct nf_conn *ct)
 221 {
 222         flow_offload_fixup_ct_state(ct);
 223         flow_offload_fixup_ct_timeout(ct);
 224 }
 225
 226 static void flow_offload_route_release(struct flow_offload *flow)
 227 {
 228         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
 229         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_REPLY);
 230 }
 231
 232 void flow_offload_free(struct flow_offload *flow)
 233 {
 234         switch (flow->type) {
 235         case NF_FLOW_OFFLOAD_ROUTE:
 236                 flow_offload_route_release(flow);
 237                 break;
 238         default:
 239                 break;
 240         }
 241         nf_ct_put(flow->ct);
 242         kfree_rcu(flow, rcu_head);
 243 }
 244 EXPORT_SYMBOL_GPL(flow_offload_free);
 245
 246 static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
 247 {
 248         const struct flow_offload_tuple *tuple = data;
 249
 250         return jhash(tuple, offsetof(struct flow_offload_tuple, __hash), seed);
 251 }
 252
 253 static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
 254 {
 255         const struct flow_offload_tuple_rhash *tuplehash = data;
 256
 257         return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, __hash), seed);
 258 }
 259
 260 static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
 261                                         const void *ptr)
 262 {
 263         const struct flow_offload_tuple *tuple = arg->key;
 264         const struct flow_offload_tuple_rhash *x = ptr;
 265
 266         if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, __hash)))
 267                 return 1;
 268
 269         return 0;
 270 }
 271
 272 static const struct rhashtable_params nf_flow_offload_rhash_params = {
 273         .head_offset            = offsetof(struct flow_offload_tuple_rhash, node),
 274         .hashfn                 = flow_offload_hash,
 275         .obj_hashfn             = flow_offload_hash_obj,
 276         .obj_cmpfn              = flow_offload_hash_cmp,
 277         .automatic_shrinking    = true,
 278 };
 279
 280 unsigned long flow_offload_get_timeout(struct flow_offload *flow)
 281 {
 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         if (l4num == IPPROTO_TCP) {
 287                 struct nf_tcp_net *tn = nf_tcp_pernet(net);
 288
 289                 timeout = tn->offload_timeout;
 290         } else if (l4num == IPPROTO_UDP) {
 291                 struct nf_udp_net *tn = nf_udp_pernet(net);
 292
 293                 timeout = tn->offload_timeout;
 294         }
 295
 296         return timeout;
 297 }
 298
 299 int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow)
 300 {
 301         int err;
 302
 303         flow->timeout = nf_flowtable_time_stamp + flow_offload_get_timeout(flow);
 304
 305         err = rhashtable_insert_fast(&flow_table->rhashtable,
 306                                      &flow->tuplehash[0].node,
 307                                      nf_flow_offload_rhash_params);
 308         if (err < 0)
 309                 return err;
 310
 311         err = rhashtable_insert_fast(&flow_table->rhashtable,
 312                                      &flow->tuplehash[1].node,
 313                                      nf_flow_offload_rhash_params);
 314         if (err < 0) {
 315                 rhashtable_remove_fast(&flow_table->rhashtable,
 316                                        &flow->tuplehash[0].node,
 317                                        nf_flow_offload_rhash_params);
 318                 return err;
 319         }
 320
 321         nf_ct_offload_timeout(flow->ct);
 322
 323         if (nf_flowtable_hw_offload(flow_table)) {
 324                 __set_bit(NF_FLOW_HW, &flow->flags);
 325                 nf_flow_offload_add(flow_table, flow);
 326         }
 327
 328         return 0;
 329 }
 330 EXPORT_SYMBOL_GPL(flow_offload_add);
 331
 332 void flow_offload_refresh(struct nf_flowtable *flow_table,
 333                           struct flow_offload *flow)
 334 {
 335         u32 timeout;
 336
 337         timeout = nf_flowtable_time_stamp + flow_offload_get_timeout(flow);
 338         if (READ_ONCE(flow->timeout) != timeout)
 339                 WRITE_ONCE(flow->timeout, timeout);
 340
 341         if (likely(!nf_flowtable_hw_offload(flow_table)))
 342                 return;
 343
 344         nf_flow_offload_add(flow_table, flow);
 345 }
 346 EXPORT_SYMBOL_GPL(flow_offload_refresh);
 347
 348 static inline bool nf_flow_has_expired(const struct flow_offload *flow)
 349 {
 350         return nf_flow_timeout_delta(flow->timeout) <= 0;
 351 }
 352
 353 static void flow_offload_del(struct nf_flowtable *flow_table,
 354                              struct flow_offload *flow)
 355 {
 356         rhashtable_remove_fast(&flow_table->rhashtable,
 357                                &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
 358                                nf_flow_offload_rhash_params);
 359         rhashtable_remove_fast(&flow_table->rhashtable,
 360                                &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
 361                                nf_flow_offload_rhash_params);
 362
 363         clear_bit(IPS_OFFLOAD_BIT, &flow->ct->status);
 364
 365         if (nf_flow_has_expired(flow))
 366                 flow_offload_fixup_ct(flow->ct);
 367         else
 368                 flow_offload_fixup_ct_timeout(flow->ct);
 369
 370         flow_offload_free(flow);
 371 }
 372
 373 void flow_offload_teardown(struct flow_offload *flow)
 374 {
 375         set_bit(NF_FLOW_TEARDOWN, &flow->flags);
 376
 377         flow_offload_fixup_ct_state(flow->ct);
 378 }
 379 EXPORT_SYMBOL_GPL(flow_offload_teardown);
 380
 381 struct flow_offload_tuple_rhash *
 382 flow_offload_lookup(struct nf_flowtable *flow_table,
 383                     struct flow_offload_tuple *tuple)
 384 {
 385         struct flow_offload_tuple_rhash *tuplehash;
 386         struct flow_offload *flow;
 387         int dir;
 388
 389         tuplehash = rhashtable_lookup(&flow_table->rhashtable, tuple,
 390                                       nf_flow_offload_rhash_params);
 391         if (!tuplehash)
 392                 return NULL;
 393
 394         dir = tuplehash->tuple.dir;
 395         flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
 396         if (test_bit(NF_FLOW_TEARDOWN, &flow->flags))
 397                 return NULL;
 398
 399         if (unlikely(nf_ct_is_dying(flow->ct)))
 400                 return NULL;
 401
 402         return tuplehash;
 403 }
 404 EXPORT_SYMBOL_GPL(flow_offload_lookup);
 405
 406 static int
 407 nf_flow_table_iterate(struct nf_flowtable *flow_table,
 408                       void (*iter)(struct nf_flowtable *flowtable,
 409                                    struct flow_offload *flow, void *data),
 410                       void *data)
 411 {
 412         struct flow_offload_tuple_rhash *tuplehash;
 413         struct rhashtable_iter hti;
 414         struct flow_offload *flow;
 415         int err = 0;
 416
 417         rhashtable_walk_enter(&flow_table->rhashtable, &hti);
 418         rhashtable_walk_start(&hti);
 419
 420         while ((tuplehash = rhashtable_walk_next(&hti))) {
 421                 if (IS_ERR(tuplehash)) {
 422                         if (PTR_ERR(tuplehash) != -EAGAIN) {
 423                                 err = PTR_ERR(tuplehash);
 424                                 break;
 425                         }
 426                         continue;
 427                 }
 428                 if (tuplehash->tuple.dir)
 429                         continue;
 430
 431                 flow = container_of(tuplehash, struct flow_offload, tuplehash[0]);
 432
 433                 iter(flow_table, flow, data);
 434         }
 435         rhashtable_walk_stop(&hti);
 436         rhashtable_walk_exit(&hti);
 437
 438         return err;
 439 }
 440
 441 static bool flow_offload_stale_dst(struct flow_offload_tuple *tuple)
 442 {
 443         struct dst_entry *dst;
 444
 445         if (tuple->xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
 446             tuple->xmit_type == FLOW_OFFLOAD_XMIT_XFRM) {
 447                 dst = tuple->dst_cache;
 448                 if (!dst_check(dst, tuple->dst_cookie))
 449                         return true;
 450         }
 451
 452         return false;
 453 }
 454
 455 static bool nf_flow_has_stale_dst(struct flow_offload *flow)
 456 {
 457         return flow_offload_stale_dst(&flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple) ||
 458                flow_offload_stale_dst(&flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple);
 459 }
 460
 461 static void nf_flow_offload_gc_step(struct nf_flowtable *flow_table,
 462                                     struct flow_offload *flow, void *data)
 463 {
 464         if (nf_flow_has_expired(flow) ||
 465             nf_ct_is_dying(flow->ct) ||
 466             nf_flow_has_stale_dst(flow))
 467                 set_bit(NF_FLOW_TEARDOWN, &flow->flags);
 468
 469         if (test_bit(NF_FLOW_TEARDOWN, &flow->flags)) {
 470                 if (test_bit(NF_FLOW_HW, &flow->flags)) {
 471                         if (!test_bit(NF_FLOW_HW_DYING, &flow->flags))
 472                                 nf_flow_offload_del(flow_table, flow);
 473                         else if (test_bit(NF_FLOW_HW_DEAD, &flow->flags))
 474                                 flow_offload_del(flow_table, flow);
 475                 } else {
 476                         flow_offload_del(flow_table, flow);
 477                 }
 478         } else if (test_bit(NF_FLOW_HW, &flow->flags)) {
 479                 nf_flow_offload_stats(flow_table, flow);
 480         }
 481 }
 482
 483 static void nf_flow_offload_work_gc(struct work_struct *work)
 484 {
 485         struct nf_flowtable *flow_table;
 486
 487         flow_table = container_of(work, struct nf_flowtable, gc_work.work);
 488         nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, NULL);
 489         queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ);
 490 }
 491
 492 static void nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff,
 493                                  __be16 port, __be16 new_port)
 494 {
 495         struct tcphdr *tcph;
 496
 497         tcph = (void *)(skb_network_header(skb) + thoff);
 498         inet_proto_csum_replace2(&tcph->check, skb, port, new_port, false);
 499 }
 500
 501 static void nf_flow_nat_port_udp(struct sk_buff *skb, unsigned int thoff,
 502                                  __be16 port, __be16 new_port)
 503 {
 504         struct udphdr *udph;
 505
 506         udph = (void *)(skb_network_header(skb) + thoff);
 507         if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 508                 inet_proto_csum_replace2(&udph->check, skb, port,
 509                                          new_port, false);
 510                 if (!udph->check)
 511                         udph->check = CSUM_MANGLED_0;
 512         }
 513 }
 514
 515 static void nf_flow_nat_port(struct sk_buff *skb, unsigned int thoff,
 516                              u8 protocol, __be16 port, __be16 new_port)
 517 {
 518         switch (protocol) {
 519         case IPPROTO_TCP:
 520                 nf_flow_nat_port_tcp(skb, thoff, port, new_port);
 521                 break;
 522         case IPPROTO_UDP:
 523                 nf_flow_nat_port_udp(skb, thoff, port, new_port);
 524                 break;
 525         }
 526 }
 527
 528 void nf_flow_snat_port(const struct flow_offload *flow,
 529                        struct sk_buff *skb, unsigned int thoff,
 530                        u8 protocol, enum flow_offload_tuple_dir dir)
 531 {
 532         struct flow_ports *hdr;
 533         __be16 port, new_port;
 534
 535         hdr = (void *)(skb_network_header(skb) + thoff);
 536
 537         switch (dir) {
 538         case FLOW_OFFLOAD_DIR_ORIGINAL:
 539                 port = hdr->source;
 540                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port;
 541                 hdr->source = new_port;
 542                 break;
 543         case FLOW_OFFLOAD_DIR_REPLY:
 544                 port = hdr->dest;
 545                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port;
 546                 hdr->dest = new_port;
 547                 break;
 548         }
 549
 550         nf_flow_nat_port(skb, thoff, protocol, port, new_port);
 551 }
 552 EXPORT_SYMBOL_GPL(nf_flow_snat_port);
 553
 554 void nf_flow_dnat_port(const struct flow_offload *flow, struct sk_buff *skb,
 555                        unsigned int thoff, u8 protocol,
 556                        enum flow_offload_tuple_dir dir)
 557 {
 558         struct flow_ports *hdr;
 559         __be16 port, new_port;
 560
 561         hdr = (void *)(skb_network_header(skb) + thoff);
 562
 563         switch (dir) {
 564         case FLOW_OFFLOAD_DIR_ORIGINAL:
 565                 port = hdr->dest;
 566                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port;
 567                 hdr->dest = new_port;
 568                 break;
 569         case FLOW_OFFLOAD_DIR_REPLY:
 570                 port = hdr->source;
 571                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port;
 572                 hdr->source = new_port;
 573                 break;
 574         }
 575
 576         nf_flow_nat_port(skb, thoff, protocol, port, new_port);
 577 }
 578 EXPORT_SYMBOL_GPL(nf_flow_dnat_port);
 579
 580 int nf_flow_table_init(struct nf_flowtable *flowtable)
 581 {
 582         int err;
 583
 584         INIT_DELAYED_WORK(&flowtable->gc_work, nf_flow_offload_work_gc);
 585         flow_block_init(&flowtable->flow_block);
 586         init_rwsem(&flowtable->flow_block_lock);
 587
 588         err = rhashtable_init(&flowtable->rhashtable,
 589                               &nf_flow_offload_rhash_params);
 590         if (err < 0)
 591                 return err;
 592
 593         queue_delayed_work(system_power_efficient_wq,
 594                            &flowtable->gc_work, HZ);
 595
 596         mutex_lock(&flowtable_lock);
 597         list_add(&flowtable->list, &flowtables);
 598         mutex_unlock(&flowtable_lock);
 599
 600         return 0;
 601 }
 602 EXPORT_SYMBOL_GPL(nf_flow_table_init);
 603
 604 static void nf_flow_table_do_cleanup(struct nf_flowtable *flow_table,
 605                                      struct flow_offload *flow, void *data)
 606 {
 607         struct net_device *dev = data;
 608
 609         if (!dev) {
 610                 flow_offload_teardown(flow);
 611                 return;
 612         }
 613
 614         if (net_eq(nf_ct_net(flow->ct), dev_net(dev)) &&
 615             (flow->tuplehash[0].tuple.iifidx == dev->ifindex ||
 616              flow->tuplehash[1].tuple.iifidx == dev->ifindex))
 617                 flow_offload_teardown(flow);
 618 }
 619
 620 void nf_flow_table_gc_cleanup(struct nf_flowtable *flowtable,
 621                               struct net_device *dev)
 622 {
 623         nf_flow_table_iterate(flowtable, nf_flow_table_do_cleanup, dev);
 624         flush_delayed_work(&flowtable->gc_work);
 625         nf_flow_table_offload_flush(flowtable);
 626 }
 627
 628 void nf_flow_table_cleanup(struct net_device *dev)
 629 {
 630         struct nf_flowtable *flowtable;
 631
 632         mutex_lock(&flowtable_lock);
 633         list_for_each_entry(flowtable, &flowtables, list)
 634                 nf_flow_table_gc_cleanup(flowtable, dev);
 635         mutex_unlock(&flowtable_lock);
 636 }
 637 EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);
 638
 639 void nf_flow_table_free(struct nf_flowtable *flow_table)
 640 {
 641         mutex_lock(&flowtable_lock);
 642         list_del(&flow_table->list);
 643         mutex_unlock(&flowtable_lock);
 644
 645         cancel_delayed_work_sync(&flow_table->gc_work);
 646         nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
 647         nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, NULL);
 648         nf_flow_table_offload_flush(flow_table);
 649         if (nf_flowtable_hw_offload(flow_table))
 650                 nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, NULL);
 651         rhashtable_destroy(&flow_table->rhashtable);
 652 }
 653 EXPORT_SYMBOL_GPL(nf_flow_table_free);
 654
 655 static int __init nf_flow_table_module_init(void)
 656 {
 657         return nf_flow_table_offload_init();
 658 }
 659
 660 static void __exit nf_flow_table_module_exit(void)
 661 {
 662         nf_flow_table_offload_exit();
 663 }
 664
 665 module_init(nf_flow_table_module_init);
 666 module_exit(nf_flow_table_module_exit);
 667
 668 MODULE_LICENSE("GPL");
 669 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
 670 MODULE_DESCRIPTION("Netfilter flow table module");