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 		if (!dst_hold_safe(route->tuple[dir].dst))
129 			return -1;
130 
131 		flow_tuple->dst_cache = dst;
132 		flow_tuple->dst_cookie = flow_offload_dst_cookie(flow_tuple);
133 		break;
134 	default:
135 		WARN_ON_ONCE(1);
136 		break;
137 	}
138 	flow_tuple->xmit_type = route->tuple[dir].xmit_type;
139 
140 	return 0;
141 }
142 
143 static void nft_flow_dst_release(struct flow_offload *flow,
144 				 enum flow_offload_tuple_dir dir)
145 {
146 	if (flow->tuplehash[dir].tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
147 	    flow->tuplehash[dir].tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)
148 		dst_release(flow->tuplehash[dir].tuple.dst_cache);
149 }
150 
151 int flow_offload_route_init(struct flow_offload *flow,
152 			    const struct nf_flow_route *route)
153 {
154 	int err;
155 
156 	err = flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_ORIGINAL);
157 	if (err < 0)
158 		return err;
159 
160 	err = flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_REPLY);
161 	if (err < 0)
162 		goto err_route_reply;
163 
164 	flow->type = NF_FLOW_OFFLOAD_ROUTE;
165 
166 	return 0;
167 
168 err_route_reply:
169 	nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
170 
171 	return err;
172 }
173 EXPORT_SYMBOL_GPL(flow_offload_route_init);
174 
175 static void flow_offload_fixup_tcp(struct ip_ct_tcp *tcp)
176 {
177 	tcp->seen[0].td_maxwin = 0;
178 	tcp->seen[1].td_maxwin = 0;
179 }
180 
181 static void flow_offload_fixup_ct(struct nf_conn *ct)
182 {
183 	struct net *net = nf_ct_net(ct);
184 	int l4num = nf_ct_protonum(ct);
185 	s32 timeout;
186 
187 	if (l4num == IPPROTO_TCP) {
188 		struct nf_tcp_net *tn = nf_tcp_pernet(net);
189 
190 		flow_offload_fixup_tcp(&ct->proto.tcp);
191 
192 		timeout = tn->timeouts[ct->proto.tcp.state];
193 		timeout -= tn->offload_timeout;
194 	} else if (l4num == IPPROTO_UDP) {
195 		struct nf_udp_net *tn = nf_udp_pernet(net);
196 		enum udp_conntrack state =
197 			test_bit(IPS_SEEN_REPLY_BIT, &ct->status) ?
198 			UDP_CT_REPLIED : UDP_CT_UNREPLIED;
199 
200 		timeout = tn->timeouts[state];
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(READ_ONCE(ct->timeout)) > (__s32)timeout)
210 		WRITE_ONCE(ct->timeout, nfct_time_stamp + timeout);
211 }
212 
213 static void flow_offload_route_release(struct flow_offload *flow)
214 {
215 	nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
216 	nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_REPLY);
217 }
218 
219 void flow_offload_free(struct flow_offload *flow)
220 {
221 	switch (flow->type) {
222 	case NF_FLOW_OFFLOAD_ROUTE:
223 		flow_offload_route_release(flow);
224 		break;
225 	default:
226 		break;
227 	}
228 	nf_ct_put(flow->ct);
229 	kfree_rcu(flow, rcu_head);
230 }
231 EXPORT_SYMBOL_GPL(flow_offload_free);
232 
233 static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
234 {
235 	const struct flow_offload_tuple *tuple = data;
236 
237 	return jhash(tuple, offsetof(struct flow_offload_tuple, __hash), seed);
238 }
239 
240 static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
241 {
242 	const struct flow_offload_tuple_rhash *tuplehash = data;
243 
244 	return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, __hash), seed);
245 }
246 
247 static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
248 					const void *ptr)
249 {
250 	const struct flow_offload_tuple *tuple = arg->key;
251 	const struct flow_offload_tuple_rhash *x = ptr;
252 
253 	if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, __hash)))
254 		return 1;
255 
256 	return 0;
257 }
258 
259 static const struct rhashtable_params nf_flow_offload_rhash_params = {
260 	.head_offset		= offsetof(struct flow_offload_tuple_rhash, node),
261 	.hashfn			= flow_offload_hash,
262 	.obj_hashfn		= flow_offload_hash_obj,
263 	.obj_cmpfn		= flow_offload_hash_cmp,
264 	.automatic_shrinking	= true,
265 };
266 
267 unsigned long flow_offload_get_timeout(struct flow_offload *flow)
268 {
269 	unsigned long timeout = NF_FLOW_TIMEOUT;
270 	struct net *net = nf_ct_net(flow->ct);
271 	int l4num = nf_ct_protonum(flow->ct);
272 
273 	if (l4num == IPPROTO_TCP) {
274 		struct nf_tcp_net *tn = nf_tcp_pernet(net);
275 
276 		timeout = tn->offload_timeout;
277 	} else if (l4num == IPPROTO_UDP) {
278 		struct nf_udp_net *tn = nf_udp_pernet(net);
279 
280 		timeout = tn->offload_timeout;
281 	}
282 
283 	return timeout;
284 }
285 
286 int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow)
287 {
288 	int err;
289 
290 	flow->timeout = nf_flowtable_time_stamp + flow_offload_get_timeout(flow);
291 
292 	err = rhashtable_insert_fast(&flow_table->rhashtable,
293 				     &flow->tuplehash[0].node,
294 				     nf_flow_offload_rhash_params);
295 	if (err < 0)
296 		return err;
297 
298 	err = rhashtable_insert_fast(&flow_table->rhashtable,
299 				     &flow->tuplehash[1].node,
300 				     nf_flow_offload_rhash_params);
301 	if (err < 0) {
302 		rhashtable_remove_fast(&flow_table->rhashtable,
303 				       &flow->tuplehash[0].node,
304 				       nf_flow_offload_rhash_params);
305 		return err;
306 	}
307 
308 	nf_ct_offload_timeout(flow->ct);
309 
310 	if (nf_flowtable_hw_offload(flow_table)) {
311 		__set_bit(NF_FLOW_HW, &flow->flags);
312 		nf_flow_offload_add(flow_table, flow);
313 	}
314 
315 	return 0;
316 }
317 EXPORT_SYMBOL_GPL(flow_offload_add);
318 
319 void flow_offload_refresh(struct nf_flowtable *flow_table,
320 			  struct flow_offload *flow)
321 {
322 	u32 timeout;
323 
324 	timeout = nf_flowtable_time_stamp + flow_offload_get_timeout(flow);
325 	if (timeout - READ_ONCE(flow->timeout) > HZ)
326 		WRITE_ONCE(flow->timeout, timeout);
327 	else
328 		return;
329 
330 	if (likely(!nf_flowtable_hw_offload(flow_table)))
331 		return;
332 
333 	nf_flow_offload_add(flow_table, flow);
334 }
335 EXPORT_SYMBOL_GPL(flow_offload_refresh);
336 
337 static inline bool nf_flow_has_expired(const struct flow_offload *flow)
338 {
339 	return nf_flow_timeout_delta(flow->timeout) <= 0;
340 }
341 
342 static void flow_offload_del(struct nf_flowtable *flow_table,
343 			     struct flow_offload *flow)
344 {
345 	rhashtable_remove_fast(&flow_table->rhashtable,
346 			       &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
347 			       nf_flow_offload_rhash_params);
348 	rhashtable_remove_fast(&flow_table->rhashtable,
349 			       &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
350 			       nf_flow_offload_rhash_params);
351 	flow_offload_free(flow);
352 }
353 
354 void flow_offload_teardown(struct flow_offload *flow)
355 {
356 	clear_bit(IPS_OFFLOAD_BIT, &flow->ct->status);
357 	set_bit(NF_FLOW_TEARDOWN, &flow->flags);
358 	flow_offload_fixup_ct(flow->ct);
359 }
360 EXPORT_SYMBOL_GPL(flow_offload_teardown);
361 
362 struct flow_offload_tuple_rhash *
363 flow_offload_lookup(struct nf_flowtable *flow_table,
364 		    struct flow_offload_tuple *tuple)
365 {
366 	struct flow_offload_tuple_rhash *tuplehash;
367 	struct flow_offload *flow;
368 	int dir;
369 
370 	tuplehash = rhashtable_lookup(&flow_table->rhashtable, tuple,
371 				      nf_flow_offload_rhash_params);
372 	if (!tuplehash)
373 		return NULL;
374 
375 	dir = tuplehash->tuple.dir;
376 	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
377 	if (test_bit(NF_FLOW_TEARDOWN, &flow->flags))
378 		return NULL;
379 
380 	if (unlikely(nf_ct_is_dying(flow->ct)))
381 		return NULL;
382 
383 	return tuplehash;
384 }
385 EXPORT_SYMBOL_GPL(flow_offload_lookup);
386 
387 static int
388 nf_flow_table_iterate(struct nf_flowtable *flow_table,
389 		      void (*iter)(struct nf_flowtable *flowtable,
390 				   struct flow_offload *flow, void *data),
391 		      void *data)
392 {
393 	struct flow_offload_tuple_rhash *tuplehash;
394 	struct rhashtable_iter hti;
395 	struct flow_offload *flow;
396 	int err = 0;
397 
398 	rhashtable_walk_enter(&flow_table->rhashtable, &hti);
399 	rhashtable_walk_start(&hti);
400 
401 	while ((tuplehash = rhashtable_walk_next(&hti))) {
402 		if (IS_ERR(tuplehash)) {
403 			if (PTR_ERR(tuplehash) != -EAGAIN) {
404 				err = PTR_ERR(tuplehash);
405 				break;
406 			}
407 			continue;
408 		}
409 		if (tuplehash->tuple.dir)
410 			continue;
411 
412 		flow = container_of(tuplehash, struct flow_offload, tuplehash[0]);
413 
414 		iter(flow_table, flow, data);
415 	}
416 	rhashtable_walk_stop(&hti);
417 	rhashtable_walk_exit(&hti);
418 
419 	return err;
420 }
421 
422 static void nf_flow_offload_gc_step(struct nf_flowtable *flow_table,
423 				    struct flow_offload *flow, void *data)
424 {
425 	if (nf_flow_has_expired(flow) ||
426 	    nf_ct_is_dying(flow->ct))
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");
696