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                 return NULL;
  58
  59         flow = kzalloc(sizeof(*flow), GFP_ATOMIC);
  60         if (!flow)
  61                 return NULL;
  62
  63         refcount_inc(&ct->ct_general.use);
  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 EXPORT_SYMBOL_GPL(flow_offload_alloc);
  77
  78 static u32 flow_offload_dst_cookie(struct flow_offload_tuple *flow_tuple)
  79 {
  80         const struct rt6_info *rt;
  81
  82         if (flow_tuple->l3proto == NFPROTO_IPV6) {
  83                 rt = (const struct rt6_info *)flow_tuple->dst_cache;
  84                 return rt6_get_cookie(rt);
  85         }
  86
  87         return 0;
  88 }
  89
  90 static struct dst_entry *nft_route_dst_fetch(struct nf_flow_route *route,
  91                                              enum flow_offload_tuple_dir dir)
  92 {
  93         struct dst_entry *dst = route->tuple[dir].dst;
  94
  95         route->tuple[dir].dst = NULL;
  96
  97         return dst;
  98 }
  99
 100 static int flow_offload_fill_route(struct flow_offload *flow,
 101                                    struct nf_flow_route *route,
 102                                    enum flow_offload_tuple_dir dir)
 103 {
 104         struct flow_offload_tuple *flow_tuple = &flow->tuplehash[dir].tuple;
 105         struct dst_entry *dst = nft_route_dst_fetch(route, dir);
 106         int i, j = 0;
 107
 108         switch (flow_tuple->l3proto) {
 109         case NFPROTO_IPV4:
 110                 flow_tuple->mtu = ip_dst_mtu_maybe_forward(dst, true);
 111                 break;
 112         case NFPROTO_IPV6:
 113                 flow_tuple->mtu = ip6_dst_mtu_maybe_forward(dst, true);
 114                 break;
 115         }
 116
 117         flow_tuple->iifidx = route->tuple[dir].in.ifindex;
 118         for (i = route->tuple[dir].in.num_encaps - 1; i >= 0; i--) {
 119                 flow_tuple->encap[j].id = route->tuple[dir].in.encap[i].id;
 120                 flow_tuple->encap[j].proto = route->tuple[dir].in.encap[i].proto;
 121                 if (route->tuple[dir].in.ingress_vlans & BIT(i))
 122                         flow_tuple->in_vlan_ingress |= BIT(j);
 123                 j++;
 124         }
 125         flow_tuple->encap_num = route->tuple[dir].in.num_encaps;
 126
 127         switch (route->tuple[dir].xmit_type) {
 128         case FLOW_OFFLOAD_XMIT_DIRECT:
 129                 memcpy(flow_tuple->out.h_dest, route->tuple[dir].out.h_dest,
 130                        ETH_ALEN);
 131                 memcpy(flow_tuple->out.h_source, route->tuple[dir].out.h_source,
 132                        ETH_ALEN);
 133                 flow_tuple->out.ifidx = route->tuple[dir].out.ifindex;
 134                 flow_tuple->out.hw_ifidx = route->tuple[dir].out.hw_ifindex;
 135                 dst_release(dst);
 136                 break;
 137         case FLOW_OFFLOAD_XMIT_XFRM:
 138         case FLOW_OFFLOAD_XMIT_NEIGH:
 139                 flow_tuple->dst_cache = dst;
 140                 flow_tuple->dst_cookie = flow_offload_dst_cookie(flow_tuple);
 141                 break;
 142         default:
 143                 WARN_ON_ONCE(1);
 144                 break;
 145         }
 146         flow_tuple->xmit_type = route->tuple[dir].xmit_type;
 147
 148         return 0;
 149 }
 150
 151 static void nft_flow_dst_release(struct flow_offload *flow,
 152                                  enum flow_offload_tuple_dir dir)
 153 {
 154         if (flow->tuplehash[dir].tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
 155             flow->tuplehash[dir].tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)
 156                 dst_release(flow->tuplehash[dir].tuple.dst_cache);
 157 }
 158
 159 void flow_offload_route_init(struct flow_offload *flow,
 160                              struct nf_flow_route *route)
 161 {
 162         flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_ORIGINAL);
 163         flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_REPLY);
 164         flow->type = NF_FLOW_OFFLOAD_ROUTE;
 165 }
 166 EXPORT_SYMBOL_GPL(flow_offload_route_init);
 167
 168 static void flow_offload_fixup_tcp(struct ip_ct_tcp *tcp)
 169 {
 170         tcp->seen[0].td_maxwin = 0;
 171         tcp->seen[1].td_maxwin = 0;
 172 }
 173
 174 static void flow_offload_fixup_ct(struct nf_conn *ct)
 175 {
 176         struct net *net = nf_ct_net(ct);
 177         int l4num = nf_ct_protonum(ct);
 178         s32 timeout;
 179
 180         if (l4num == IPPROTO_TCP) {
 181                 struct nf_tcp_net *tn = nf_tcp_pernet(net);
 182
 183                 flow_offload_fixup_tcp(&ct->proto.tcp);
 184
 185                 timeout = tn->timeouts[ct->proto.tcp.state];
 186                 timeout -= tn->offload_timeout;
 187         } else if (l4num == IPPROTO_UDP) {
 188                 struct nf_udp_net *tn = nf_udp_pernet(net);
 189                 enum udp_conntrack state =
 190                         test_bit(IPS_SEEN_REPLY_BIT, &ct->status) ?
 191                         UDP_CT_REPLIED : UDP_CT_UNREPLIED;
 192
 193                 timeout = tn->timeouts[state];
 194                 timeout -= tn->offload_timeout;
 195         } else {
 196                 return;
 197         }
 198
 199         if (timeout < 0)
 200                 timeout = 0;
 201
 202         if (nf_flow_timeout_delta(READ_ONCE(ct->timeout)) > (__s32)timeout)
 203                 WRITE_ONCE(ct->timeout, nfct_time_stamp + timeout);
 204 }
 205
 206 static void flow_offload_route_release(struct flow_offload *flow)
 207 {
 208         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
 209         nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_REPLY);
 210 }
 211
 212 void flow_offload_free(struct flow_offload *flow)
 213 {
 214         switch (flow->type) {
 215         case NF_FLOW_OFFLOAD_ROUTE:
 216                 flow_offload_route_release(flow);
 217                 break;
 218         default:
 219                 break;
 220         }
 221         nf_ct_put(flow->ct);
 222         kfree_rcu(flow, rcu_head);
 223 }
 224 EXPORT_SYMBOL_GPL(flow_offload_free);
 225
 226 static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
 227 {
 228         const struct flow_offload_tuple *tuple = data;
 229
 230         return jhash(tuple, offsetof(struct flow_offload_tuple, __hash), seed);
 231 }
 232
 233 static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
 234 {
 235         const struct flow_offload_tuple_rhash *tuplehash = data;
 236
 237         return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, __hash), seed);
 238 }
 239
 240 static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
 241                                         const void *ptr)
 242 {
 243         const struct flow_offload_tuple *tuple = arg->key;
 244         const struct flow_offload_tuple_rhash *x = ptr;
 245
 246         if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, __hash)))
 247                 return 1;
 248
 249         return 0;
 250 }
 251
 252 static const struct rhashtable_params nf_flow_offload_rhash_params = {
 253         .head_offset            = offsetof(struct flow_offload_tuple_rhash, node),
 254         .hashfn                 = flow_offload_hash,
 255         .obj_hashfn             = flow_offload_hash_obj,
 256         .obj_cmpfn              = flow_offload_hash_cmp,
 257         .automatic_shrinking    = true,
 258 };
 259
 260 unsigned long flow_offload_get_timeout(struct flow_offload *flow)
 261 {
 262         unsigned long timeout = NF_FLOW_TIMEOUT;
 263         struct net *net = nf_ct_net(flow->ct);
 264         int l4num = nf_ct_protonum(flow->ct);
 265
 266         if (l4num == IPPROTO_TCP) {
 267                 struct nf_tcp_net *tn = nf_tcp_pernet(net);
 268
 269                 timeout = tn->offload_timeout;
 270         } else if (l4num == IPPROTO_UDP) {
 271                 struct nf_udp_net *tn = nf_udp_pernet(net);
 272
 273                 timeout = tn->offload_timeout;
 274         }
 275
 276         return timeout;
 277 }
 278
 279 int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow)
 280 {
 281         int err;
 282
 283         flow->timeout = nf_flowtable_time_stamp + flow_offload_get_timeout(flow);
 284
 285         err = rhashtable_insert_fast(&flow_table->rhashtable,
 286                                      &flow->tuplehash[0].node,
 287                                      nf_flow_offload_rhash_params);
 288         if (err < 0)
 289                 return err;
 290
 291         err = rhashtable_insert_fast(&flow_table->rhashtable,
 292                                      &flow->tuplehash[1].node,
 293                                      nf_flow_offload_rhash_params);
 294         if (err < 0) {
 295                 rhashtable_remove_fast(&flow_table->rhashtable,
 296                                        &flow->tuplehash[0].node,
 297                                        nf_flow_offload_rhash_params);
 298                 return err;
 299         }
 300
 301         nf_ct_offload_timeout(flow->ct);
 302
 303         if (nf_flowtable_hw_offload(flow_table)) {
 304                 __set_bit(NF_FLOW_HW, &flow->flags);
 305                 nf_flow_offload_add(flow_table, flow);
 306         }
 307
 308         return 0;
 309 }
 310 EXPORT_SYMBOL_GPL(flow_offload_add);
 311
 312 void flow_offload_refresh(struct nf_flowtable *flow_table,
 313                           struct flow_offload *flow, bool force)
 314 {
 315         u32 timeout;
 316
 317         timeout = nf_flowtable_time_stamp + flow_offload_get_timeout(flow);
 318         if (force || timeout - READ_ONCE(flow->timeout) > HZ)
 319                 WRITE_ONCE(flow->timeout, timeout);
 320         else
 321                 return;
 322
 323         if (likely(!nf_flowtable_hw_offload(flow_table)))
 324                 return;
 325
 326         nf_flow_offload_add(flow_table, flow);
 327 }
 328 EXPORT_SYMBOL_GPL(flow_offload_refresh);
 329
 330 static inline bool nf_flow_has_expired(const struct flow_offload *flow)
 331 {
 332         return nf_flow_timeout_delta(flow->timeout) <= 0;
 333 }
 334
 335 static void flow_offload_del(struct nf_flowtable *flow_table,
 336                              struct flow_offload *flow)
 337 {
 338         rhashtable_remove_fast(&flow_table->rhashtable,
 339                                &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
 340                                nf_flow_offload_rhash_params);
 341         rhashtable_remove_fast(&flow_table->rhashtable,
 342                                &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
 343                                nf_flow_offload_rhash_params);
 344         flow_offload_free(flow);
 345 }
 346
 347 void flow_offload_teardown(struct flow_offload *flow)
 348 {
 349         clear_bit(IPS_OFFLOAD_BIT, &flow->ct->status);
 350         set_bit(NF_FLOW_TEARDOWN, &flow->flags);
 351         flow_offload_fixup_ct(flow->ct);
 352 }
 353 EXPORT_SYMBOL_GPL(flow_offload_teardown);
 354
 355 struct flow_offload_tuple_rhash *
 356 flow_offload_lookup(struct nf_flowtable *flow_table,
 357                     struct flow_offload_tuple *tuple)
 358 {
 359         struct flow_offload_tuple_rhash *tuplehash;
 360         struct flow_offload *flow;
 361         int dir;
 362
 363         tuplehash = rhashtable_lookup(&flow_table->rhashtable, tuple,
 364                                       nf_flow_offload_rhash_params);
 365         if (!tuplehash)
 366                 return NULL;
 367
 368         dir = tuplehash->tuple.dir;
 369         flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
 370         if (test_bit(NF_FLOW_TEARDOWN, &flow->flags))
 371                 return NULL;
 372
 373         if (unlikely(nf_ct_is_dying(flow->ct)))
 374                 return NULL;
 375
 376         return tuplehash;
 377 }
 378 EXPORT_SYMBOL_GPL(flow_offload_lookup);
 379
 380 static int
 381 nf_flow_table_iterate(struct nf_flowtable *flow_table,
 382                       void (*iter)(struct nf_flowtable *flowtable,
 383                                    struct flow_offload *flow, void *data),
 384                       void *data)
 385 {
 386         struct flow_offload_tuple_rhash *tuplehash;
 387         struct rhashtable_iter hti;
 388         struct flow_offload *flow;
 389         int err = 0;
 390
 391         rhashtable_walk_enter(&flow_table->rhashtable, &hti);
 392         rhashtable_walk_start(&hti);
 393
 394         while ((tuplehash = rhashtable_walk_next(&hti))) {
 395                 if (IS_ERR(tuplehash)) {
 396                         if (PTR_ERR(tuplehash) != -EAGAIN) {
 397                                 err = PTR_ERR(tuplehash);
 398                                 break;
 399                         }
 400                         continue;
 401                 }
 402                 if (tuplehash->tuple.dir)
 403                         continue;
 404
 405                 flow = container_of(tuplehash, struct flow_offload, tuplehash[0]);
 406
 407                 iter(flow_table, flow, data);
 408         }
 409         rhashtable_walk_stop(&hti);
 410         rhashtable_walk_exit(&hti);
 411
 412         return err;
 413 }
 414
 415 static bool nf_flow_custom_gc(struct nf_flowtable *flow_table,
 416                               const struct flow_offload *flow)
 417 {
 418         return flow_table->type->gc && flow_table->type->gc(flow);
 419 }
 420
 421 static void nf_flow_offload_gc_step(struct nf_flowtable *flow_table,
 422                                     struct flow_offload *flow, void *data)
 423 {
 424         if (nf_flow_has_expired(flow) ||
 425             nf_ct_is_dying(flow->ct) ||
 426             nf_flow_custom_gc(flow_table, flow))
 427                 flow_offload_teardown(flow);
 428
 429         if (test_bit(NF_FLOW_TEARDOWN, &flow->flags)) {
 430                 if (test_bit(NF_FLOW_HW, &flow->flags)) {
 431                         if (!test_bit(NF_FLOW_HW_DYING, &flow->flags))
 432                                 nf_flow_offload_del(flow_table, flow);
 433                         else if (test_bit(NF_FLOW_HW_DEAD, &flow->flags))
 434                                 flow_offload_del(flow_table, flow);
 435                 } else {
 436                         flow_offload_del(flow_table, flow);
 437                 }
 438         } else if (test_bit(NF_FLOW_HW, &flow->flags)) {
 439                 nf_flow_offload_stats(flow_table, flow);
 440         }
 441 }
 442
 443 void nf_flow_table_gc_run(struct nf_flowtable *flow_table)
 444 {
 445         nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, NULL);
 446 }
 447
 448 static void nf_flow_offload_work_gc(struct work_struct *work)
 449 {
 450         struct nf_flowtable *flow_table;
 451
 452         flow_table = container_of(work, struct nf_flowtable, gc_work.work);
 453         nf_flow_table_gc_run(flow_table);
 454         queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ);
 455 }
 456
 457 static void nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff,
 458                                  __be16 port, __be16 new_port)
 459 {
 460         struct tcphdr *tcph;
 461
 462         tcph = (void *)(skb_network_header(skb) + thoff);
 463         inet_proto_csum_replace2(&tcph->check, skb, port, new_port, false);
 464 }
 465
 466 static void nf_flow_nat_port_udp(struct sk_buff *skb, unsigned int thoff,
 467                                  __be16 port, __be16 new_port)
 468 {
 469         struct udphdr *udph;
 470
 471         udph = (void *)(skb_network_header(skb) + thoff);
 472         if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 473                 inet_proto_csum_replace2(&udph->check, skb, port,
 474                                          new_port, false);
 475                 if (!udph->check)
 476                         udph->check = CSUM_MANGLED_0;
 477         }
 478 }
 479
 480 static void nf_flow_nat_port(struct sk_buff *skb, unsigned int thoff,
 481                              u8 protocol, __be16 port, __be16 new_port)
 482 {
 483         switch (protocol) {
 484         case IPPROTO_TCP:
 485                 nf_flow_nat_port_tcp(skb, thoff, port, new_port);
 486                 break;
 487         case IPPROTO_UDP:
 488                 nf_flow_nat_port_udp(skb, thoff, port, new_port);
 489                 break;
 490         }
 491 }
 492
 493 void nf_flow_snat_port(const struct flow_offload *flow,
 494                        struct sk_buff *skb, unsigned int thoff,
 495                        u8 protocol, enum flow_offload_tuple_dir dir)
 496 {
 497         struct flow_ports *hdr;
 498         __be16 port, new_port;
 499
 500         hdr = (void *)(skb_network_header(skb) + thoff);
 501
 502         switch (dir) {
 503         case FLOW_OFFLOAD_DIR_ORIGINAL:
 504                 port = hdr->source;
 505                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port;
 506                 hdr->source = new_port;
 507                 break;
 508         case FLOW_OFFLOAD_DIR_REPLY:
 509                 port = hdr->dest;
 510                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port;
 511                 hdr->dest = new_port;
 512                 break;
 513         }
 514
 515         nf_flow_nat_port(skb, thoff, protocol, port, new_port);
 516 }
 517 EXPORT_SYMBOL_GPL(nf_flow_snat_port);
 518
 519 void nf_flow_dnat_port(const struct flow_offload *flow, struct sk_buff *skb,
 520                        unsigned int thoff, u8 protocol,
 521                        enum flow_offload_tuple_dir dir)
 522 {
 523         struct flow_ports *hdr;
 524         __be16 port, new_port;
 525
 526         hdr = (void *)(skb_network_header(skb) + thoff);
 527
 528         switch (dir) {
 529         case FLOW_OFFLOAD_DIR_ORIGINAL:
 530                 port = hdr->dest;
 531                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port;
 532                 hdr->dest = new_port;
 533                 break;
 534         case FLOW_OFFLOAD_DIR_REPLY:
 535                 port = hdr->source;
 536                 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port;
 537                 hdr->source = new_port;
 538                 break;
 539         }
 540
 541         nf_flow_nat_port(skb, thoff, protocol, port, new_port);
 542 }
 543 EXPORT_SYMBOL_GPL(nf_flow_dnat_port);
 544
 545 int nf_flow_table_init(struct nf_flowtable *flowtable)
 546 {
 547         int err;
 548
 549         INIT_DELAYED_WORK(&flowtable->gc_work, nf_flow_offload_work_gc);
 550         flow_block_init(&flowtable->flow_block);
 551         init_rwsem(&flowtable->flow_block_lock);
 552
 553         err = rhashtable_init(&flowtable->rhashtable,
 554                               &nf_flow_offload_rhash_params);
 555         if (err < 0)
 556                 return err;
 557
 558         queue_delayed_work(system_power_efficient_wq,
 559                            &flowtable->gc_work, HZ);
 560
 561         mutex_lock(&flowtable_lock);
 562         list_add(&flowtable->list, &flowtables);
 563         mutex_unlock(&flowtable_lock);
 564
 565         return 0;
 566 }
 567 EXPORT_SYMBOL_GPL(nf_flow_table_init);
 568
 569 static void nf_flow_table_do_cleanup(struct nf_flowtable *flow_table,
 570                                      struct flow_offload *flow, void *data)
 571 {
 572         struct net_device *dev = data;
 573
 574         if (!dev) {
 575                 flow_offload_teardown(flow);
 576                 return;
 577         }
 578
 579         if (net_eq(nf_ct_net(flow->ct), dev_net(dev)) &&
 580             (flow->tuplehash[0].tuple.iifidx == dev->ifindex ||
 581              flow->tuplehash[1].tuple.iifidx == dev->ifindex))
 582                 flow_offload_teardown(flow);
 583 }
 584
 585 void nf_flow_table_gc_cleanup(struct nf_flowtable *flowtable,
 586                               struct net_device *dev)
 587 {
 588         nf_flow_table_iterate(flowtable, nf_flow_table_do_cleanup, dev);
 589         flush_delayed_work(&flowtable->gc_work);
 590         nf_flow_table_offload_flush(flowtable);
 591 }
 592
 593 void nf_flow_table_cleanup(struct net_device *dev)
 594 {
 595         struct nf_flowtable *flowtable;
 596
 597         mutex_lock(&flowtable_lock);
 598         list_for_each_entry(flowtable, &flowtables, list)
 599                 nf_flow_table_gc_cleanup(flowtable, dev);
 600         mutex_unlock(&flowtable_lock);
 601 }
 602 EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);
 603
 604 void nf_flow_table_free(struct nf_flowtable *flow_table)
 605 {
 606         mutex_lock(&flowtable_lock);
 607         list_del(&flow_table->list);
 608         mutex_unlock(&flowtable_lock);
 609
 610         cancel_delayed_work_sync(&flow_table->gc_work);
 611         nf_flow_table_offload_flush(flow_table);
 612         /* ... no more pending work after this stage ... */
 613         nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
 614         nf_flow_table_gc_run(flow_table);
 615         nf_flow_table_offload_flush_cleanup(flow_table);
 616         rhashtable_destroy(&flow_table->rhashtable);
 617 }
 618 EXPORT_SYMBOL_GPL(nf_flow_table_free);
 619
 620 static int nf_flow_table_init_net(struct net *net)
 621 {
 622         net->ft.stat = alloc_percpu(struct nf_flow_table_stat);
 623         return net->ft.stat ? 0 : -ENOMEM;
 624 }
 625
 626 static void nf_flow_table_fini_net(struct net *net)
 627 {
 628         free_percpu(net->ft.stat);
 629 }
 630
 631 static int nf_flow_table_pernet_init(struct net *net)
 632 {
 633         int ret;
 634
 635         ret = nf_flow_table_init_net(net);
 636         if (ret < 0)
 637                 return ret;
 638
 639         ret = nf_flow_table_init_proc(net);
 640         if (ret < 0)
 641                 goto out_proc;
 642
 643         return 0;
 644
 645 out_proc:
 646         nf_flow_table_fini_net(net);
 647         return ret;
 648 }
 649
 650 static void nf_flow_table_pernet_exit(struct list_head *net_exit_list)
 651 {
 652         struct net *net;
 653
 654         list_for_each_entry(net, net_exit_list, exit_list) {
 655                 nf_flow_table_fini_proc(net);
 656                 nf_flow_table_fini_net(net);
 657         }
 658 }
 659
 660 static struct pernet_operations nf_flow_table_net_ops = {
 661         .init = nf_flow_table_pernet_init,
 662         .exit_batch = nf_flow_table_pernet_exit,
 663 };
 664
 665 static int __init nf_flow_table_module_init(void)
 666 {
 667         int ret;
 668
 669         ret = register_pernet_subsys(&nf_flow_table_net_ops);
 670         if (ret < 0)
 671                 return ret;
 672
 673         ret = nf_flow_table_offload_init();
 674         if (ret)
 675                 goto out_offload;
 676
 677         return 0;
 678
 679 out_offload:
 680         unregister_pernet_subsys(&nf_flow_table_net_ops);
 681         return ret;
 682 }
 683
 684 static void __exit nf_flow_table_module_exit(void)
 685 {
 686         nf_flow_table_offload_exit();
 687         unregister_pernet_subsys(&nf_flow_table_net_ops);
 688 }
 689
 690 module_init(nf_flow_table_module_init);
 691 module_exit(nf_flow_table_module_exit);
 692
 693 MODULE_LICENSE("GPL");
 694 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
 695 MODULE_DESCRIPTION("Netfilter flow table module");