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