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