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>
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>
17 static DEFINE_MUTEX(flowtable_lock);
18 static LIST_HEAD(flowtables);
21 flow_offload_fill_dir(struct flow_offload *flow,
22 enum flow_offload_tuple_dir dir)
24 struct flow_offload_tuple *ft = &flow->tuplehash[dir].tuple;
25 struct nf_conntrack_tuple *ctt = &flow->ct->tuplehash[dir].tuple;
29 switch (ctt->src.l3num) {
31 ft->src_v4 = ctt->src.u3.in;
32 ft->dst_v4 = ctt->dst.u3.in;
35 ft->src_v6 = ctt->src.u3.in6;
36 ft->dst_v6 = ctt->dst.u3.in6;
40 ft->l3proto = ctt->src.l3num;
41 ft->l4proto = ctt->dst.protonum;
43 switch (ctt->dst.protonum) {
46 ft->src_port = ctt->src.u.tcp.port;
47 ft->dst_port = ctt->dst.u.tcp.port;
52 struct flow_offload *flow_offload_alloc(struct nf_conn *ct)
54 struct flow_offload *flow;
56 if (unlikely(nf_ct_is_dying(ct)))
59 flow = kzalloc(sizeof(*flow), GFP_ATOMIC);
63 refcount_inc(&ct->ct_general.use);
66 flow_offload_fill_dir(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
67 flow_offload_fill_dir(flow, FLOW_OFFLOAD_DIR_REPLY);
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);
76 EXPORT_SYMBOL_GPL(flow_offload_alloc);
78 static u32 flow_offload_dst_cookie(struct flow_offload_tuple *flow_tuple)
80 const struct rt6_info *rt;
82 if (flow_tuple->l3proto == NFPROTO_IPV6) {
83 rt = (const struct rt6_info *)flow_tuple->dst_cache;
84 return rt6_get_cookie(rt);
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)
94 struct flow_offload_tuple *flow_tuple = &flow->tuplehash[dir].tuple;
95 struct dst_entry *dst = route->tuple[dir].dst;
98 switch (flow_tuple->l3proto) {
100 flow_tuple->mtu = ip_dst_mtu_maybe_forward(dst, true);
103 flow_tuple->mtu = ip6_dst_mtu_maybe_forward(dst, true);
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);
115 flow_tuple->encap_num = route->tuple[dir].in.num_encaps;
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,
121 memcpy(flow_tuple->out.h_source, route->tuple[dir].out.h_source,
123 flow_tuple->out.ifidx = route->tuple[dir].out.ifindex;
124 flow_tuple->out.hw_ifidx = route->tuple[dir].out.hw_ifindex;
126 case FLOW_OFFLOAD_XMIT_XFRM:
127 case FLOW_OFFLOAD_XMIT_NEIGH:
128 if (!dst_hold_safe(route->tuple[dir].dst))
131 flow_tuple->dst_cache = dst;
132 flow_tuple->dst_cookie = flow_offload_dst_cookie(flow_tuple);
138 flow_tuple->xmit_type = route->tuple[dir].xmit_type;
143 static void nft_flow_dst_release(struct flow_offload *flow,
144 enum flow_offload_tuple_dir dir)
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);
151 int flow_offload_route_init(struct flow_offload *flow,
152 const struct nf_flow_route *route)
156 err = flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_ORIGINAL);
160 err = flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_REPLY);
162 goto err_route_reply;
164 flow->type = NF_FLOW_OFFLOAD_ROUTE;
169 nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
173 EXPORT_SYMBOL_GPL(flow_offload_route_init);
175 static void flow_offload_fixup_tcp(struct ip_ct_tcp *tcp)
177 tcp->seen[0].td_maxwin = 0;
178 tcp->seen[1].td_maxwin = 0;
181 static void flow_offload_fixup_ct(struct nf_conn *ct)
183 struct net *net = nf_ct_net(ct);
184 int l4num = nf_ct_protonum(ct);
187 if (l4num == IPPROTO_TCP) {
188 struct nf_tcp_net *tn = nf_tcp_pernet(net);
190 flow_offload_fixup_tcp(&ct->proto.tcp);
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;
200 timeout = tn->timeouts[state];
201 timeout -= tn->offload_timeout;
209 if (nf_flow_timeout_delta(READ_ONCE(ct->timeout)) > (__s32)timeout)
210 WRITE_ONCE(ct->timeout, nfct_time_stamp + timeout);
213 static void flow_offload_route_release(struct flow_offload *flow)
215 nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
216 nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_REPLY);
219 void flow_offload_free(struct flow_offload *flow)
221 switch (flow->type) {
222 case NF_FLOW_OFFLOAD_ROUTE:
223 flow_offload_route_release(flow);
229 kfree_rcu(flow, rcu_head);
231 EXPORT_SYMBOL_GPL(flow_offload_free);
233 static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
235 const struct flow_offload_tuple *tuple = data;
237 return jhash(tuple, offsetof(struct flow_offload_tuple, __hash), seed);
240 static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
242 const struct flow_offload_tuple_rhash *tuplehash = data;
244 return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, __hash), seed);
247 static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
250 const struct flow_offload_tuple *tuple = arg->key;
251 const struct flow_offload_tuple_rhash *x = ptr;
253 if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, __hash)))
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,
267 unsigned long flow_offload_get_timeout(struct flow_offload *flow)
269 unsigned long timeout = NF_FLOW_TIMEOUT;
270 struct net *net = nf_ct_net(flow->ct);
271 int l4num = nf_ct_protonum(flow->ct);
273 if (l4num == IPPROTO_TCP) {
274 struct nf_tcp_net *tn = nf_tcp_pernet(net);
276 timeout = tn->offload_timeout;
277 } else if (l4num == IPPROTO_UDP) {
278 struct nf_udp_net *tn = nf_udp_pernet(net);
280 timeout = tn->offload_timeout;
286 int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow)
290 flow->timeout = nf_flowtable_time_stamp + flow_offload_get_timeout(flow);
292 err = rhashtable_insert_fast(&flow_table->rhashtable,
293 &flow->tuplehash[0].node,
294 nf_flow_offload_rhash_params);
298 err = rhashtable_insert_fast(&flow_table->rhashtable,
299 &flow->tuplehash[1].node,
300 nf_flow_offload_rhash_params);
302 rhashtable_remove_fast(&flow_table->rhashtable,
303 &flow->tuplehash[0].node,
304 nf_flow_offload_rhash_params);
308 nf_ct_offload_timeout(flow->ct);
310 if (nf_flowtable_hw_offload(flow_table)) {
311 __set_bit(NF_FLOW_HW, &flow->flags);
312 nf_flow_offload_add(flow_table, flow);
317 EXPORT_SYMBOL_GPL(flow_offload_add);
319 void flow_offload_refresh(struct nf_flowtable *flow_table,
320 struct flow_offload *flow)
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);
330 if (likely(!nf_flowtable_hw_offload(flow_table)))
333 nf_flow_offload_add(flow_table, flow);
335 EXPORT_SYMBOL_GPL(flow_offload_refresh);
337 static inline bool nf_flow_has_expired(const struct flow_offload *flow)
339 return nf_flow_timeout_delta(flow->timeout) <= 0;
342 static void flow_offload_del(struct nf_flowtable *flow_table,
343 struct flow_offload *flow)
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);
354 void flow_offload_teardown(struct flow_offload *flow)
356 clear_bit(IPS_OFFLOAD_BIT, &flow->ct->status);
357 set_bit(NF_FLOW_TEARDOWN, &flow->flags);
358 flow_offload_fixup_ct(flow->ct);
360 EXPORT_SYMBOL_GPL(flow_offload_teardown);
362 struct flow_offload_tuple_rhash *
363 flow_offload_lookup(struct nf_flowtable *flow_table,
364 struct flow_offload_tuple *tuple)
366 struct flow_offload_tuple_rhash *tuplehash;
367 struct flow_offload *flow;
370 tuplehash = rhashtable_lookup(&flow_table->rhashtable, tuple,
371 nf_flow_offload_rhash_params);
375 dir = tuplehash->tuple.dir;
376 flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
377 if (test_bit(NF_FLOW_TEARDOWN, &flow->flags))
380 if (unlikely(nf_ct_is_dying(flow->ct)))
385 EXPORT_SYMBOL_GPL(flow_offload_lookup);
388 nf_flow_table_iterate(struct nf_flowtable *flow_table,
389 void (*iter)(struct nf_flowtable *flowtable,
390 struct flow_offload *flow, void *data),
393 struct flow_offload_tuple_rhash *tuplehash;
394 struct rhashtable_iter hti;
395 struct flow_offload *flow;
398 rhashtable_walk_enter(&flow_table->rhashtable, &hti);
399 rhashtable_walk_start(&hti);
401 while ((tuplehash = rhashtable_walk_next(&hti))) {
402 if (IS_ERR(tuplehash)) {
403 if (PTR_ERR(tuplehash) != -EAGAIN) {
404 err = PTR_ERR(tuplehash);
409 if (tuplehash->tuple.dir)
412 flow = container_of(tuplehash, struct flow_offload, tuplehash[0]);
414 iter(flow_table, flow, data);
416 rhashtable_walk_stop(&hti);
417 rhashtable_walk_exit(&hti);
422 static void nf_flow_offload_gc_step(struct nf_flowtable *flow_table,
423 struct flow_offload *flow, void *data)
425 if (nf_flow_has_expired(flow) ||
426 nf_ct_is_dying(flow->ct))
427 flow_offload_teardown(flow);
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);
436 flow_offload_del(flow_table, flow);
438 } else if (test_bit(NF_FLOW_HW, &flow->flags)) {
439 nf_flow_offload_stats(flow_table, flow);
443 void nf_flow_table_gc_run(struct nf_flowtable *flow_table)
445 nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, NULL);
448 static void nf_flow_offload_work_gc(struct work_struct *work)
450 struct nf_flowtable *flow_table;
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);
457 static void nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff,
458 __be16 port, __be16 new_port)
462 tcph = (void *)(skb_network_header(skb) + thoff);
463 inet_proto_csum_replace2(&tcph->check, skb, port, new_port, false);
466 static void nf_flow_nat_port_udp(struct sk_buff *skb, unsigned int thoff,
467 __be16 port, __be16 new_port)
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,
476 udph->check = CSUM_MANGLED_0;
480 static void nf_flow_nat_port(struct sk_buff *skb, unsigned int thoff,
481 u8 protocol, __be16 port, __be16 new_port)
485 nf_flow_nat_port_tcp(skb, thoff, port, new_port);
488 nf_flow_nat_port_udp(skb, thoff, port, new_port);
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)
497 struct flow_ports *hdr;
498 __be16 port, new_port;
500 hdr = (void *)(skb_network_header(skb) + thoff);
503 case FLOW_OFFLOAD_DIR_ORIGINAL:
505 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port;
506 hdr->source = new_port;
508 case FLOW_OFFLOAD_DIR_REPLY:
510 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port;
511 hdr->dest = new_port;
515 nf_flow_nat_port(skb, thoff, protocol, port, new_port);
517 EXPORT_SYMBOL_GPL(nf_flow_snat_port);
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)
523 struct flow_ports *hdr;
524 __be16 port, new_port;
526 hdr = (void *)(skb_network_header(skb) + thoff);
529 case FLOW_OFFLOAD_DIR_ORIGINAL:
531 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port;
532 hdr->dest = new_port;
534 case FLOW_OFFLOAD_DIR_REPLY:
536 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port;
537 hdr->source = new_port;
541 nf_flow_nat_port(skb, thoff, protocol, port, new_port);
543 EXPORT_SYMBOL_GPL(nf_flow_dnat_port);
545 int nf_flow_table_init(struct nf_flowtable *flowtable)
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);
553 err = rhashtable_init(&flowtable->rhashtable,
554 &nf_flow_offload_rhash_params);
558 queue_delayed_work(system_power_efficient_wq,
559 &flowtable->gc_work, HZ);
561 mutex_lock(&flowtable_lock);
562 list_add(&flowtable->list, &flowtables);
563 mutex_unlock(&flowtable_lock);
567 EXPORT_SYMBOL_GPL(nf_flow_table_init);
569 static void nf_flow_table_do_cleanup(struct nf_flowtable *flow_table,
570 struct flow_offload *flow, void *data)
572 struct net_device *dev = data;
575 flow_offload_teardown(flow);
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);
585 void nf_flow_table_gc_cleanup(struct nf_flowtable *flowtable,
586 struct net_device *dev)
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);
593 void nf_flow_table_cleanup(struct net_device *dev)
595 struct nf_flowtable *flowtable;
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);
602 EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);
604 void nf_flow_table_free(struct nf_flowtable *flow_table)
606 mutex_lock(&flowtable_lock);
607 list_del(&flow_table->list);
608 mutex_unlock(&flowtable_lock);
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);
618 EXPORT_SYMBOL_GPL(nf_flow_table_free);
620 static int nf_flow_table_init_net(struct net *net)
622 net->ft.stat = alloc_percpu(struct nf_flow_table_stat);
623 return net->ft.stat ? 0 : -ENOMEM;
626 static void nf_flow_table_fini_net(struct net *net)
628 free_percpu(net->ft.stat);
631 static int nf_flow_table_pernet_init(struct net *net)
635 ret = nf_flow_table_init_net(net);
639 ret = nf_flow_table_init_proc(net);
646 nf_flow_table_fini_net(net);
650 static void nf_flow_table_pernet_exit(struct list_head *net_exit_list)
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);
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,
665 static int __init nf_flow_table_module_init(void)
669 ret = register_pernet_subsys(&nf_flow_table_net_ops);
673 ret = nf_flow_table_offload_init();
680 unregister_pernet_subsys(&nf_flow_table_net_ops);
684 static void __exit nf_flow_table_module_exit(void)
686 nf_flow_table_offload_exit();
687 unregister_pernet_subsys(&nf_flow_table_net_ops);
690 module_init(nf_flow_table_module_init);
691 module_exit(nf_flow_table_module_exit);
693 MODULE_LICENSE("GPL");
694 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
695 MODULE_DESCRIPTION("Netfilter flow table module");