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;
42 ft->src_port = ctt->src.u.tcp.port;
43 ft->dst_port = ctt->dst.u.tcp.port;
46 struct flow_offload *flow_offload_alloc(struct nf_conn *ct)
48 struct flow_offload *flow;
50 if (unlikely(nf_ct_is_dying(ct) ||
51 !atomic_inc_not_zero(&ct->ct_general.use)))
54 flow = kzalloc(sizeof(*flow), GFP_ATOMIC);
60 flow_offload_fill_dir(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
61 flow_offload_fill_dir(flow, FLOW_OFFLOAD_DIR_REPLY);
63 if (ct->status & IPS_SRC_NAT)
64 __set_bit(NF_FLOW_SNAT, &flow->flags);
65 if (ct->status & IPS_DST_NAT)
66 __set_bit(NF_FLOW_DNAT, &flow->flags);
75 EXPORT_SYMBOL_GPL(flow_offload_alloc);
77 static int flow_offload_fill_route(struct flow_offload *flow,
78 const struct nf_flow_route *route,
79 enum flow_offload_tuple_dir dir)
81 struct flow_offload_tuple *flow_tuple = &flow->tuplehash[dir].tuple;
82 struct dst_entry *other_dst = route->tuple[!dir].dst;
83 struct dst_entry *dst = route->tuple[dir].dst;
85 if (!dst_hold_safe(route->tuple[dir].dst))
88 switch (flow_tuple->l3proto) {
90 flow_tuple->mtu = ip_dst_mtu_maybe_forward(dst, true);
93 flow_tuple->mtu = ip6_dst_mtu_forward(dst);
97 flow_tuple->iifidx = other_dst->dev->ifindex;
98 flow_tuple->dst_cache = dst;
103 int flow_offload_route_init(struct flow_offload *flow,
104 const struct nf_flow_route *route)
108 err = flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_ORIGINAL);
112 err = flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_REPLY);
114 goto err_route_reply;
116 flow->type = NF_FLOW_OFFLOAD_ROUTE;
121 dst_release(route->tuple[FLOW_OFFLOAD_DIR_ORIGINAL].dst);
125 EXPORT_SYMBOL_GPL(flow_offload_route_init);
127 static void flow_offload_fixup_tcp(struct ip_ct_tcp *tcp)
129 tcp->state = TCP_CONNTRACK_ESTABLISHED;
130 tcp->seen[0].td_maxwin = 0;
131 tcp->seen[1].td_maxwin = 0;
134 #define NF_FLOWTABLE_TCP_PICKUP_TIMEOUT (120 * HZ)
135 #define NF_FLOWTABLE_UDP_PICKUP_TIMEOUT (30 * HZ)
137 static void flow_offload_fixup_ct_timeout(struct nf_conn *ct)
139 const struct nf_conntrack_l4proto *l4proto;
140 int l4num = nf_ct_protonum(ct);
141 unsigned int timeout;
143 l4proto = nf_ct_l4proto_find(l4num);
147 if (l4num == IPPROTO_TCP)
148 timeout = NF_FLOWTABLE_TCP_PICKUP_TIMEOUT;
149 else if (l4num == IPPROTO_UDP)
150 timeout = NF_FLOWTABLE_UDP_PICKUP_TIMEOUT;
154 if (nf_flow_timeout_delta(ct->timeout) > (__s32)timeout)
155 ct->timeout = nfct_time_stamp + timeout;
158 static void flow_offload_fixup_ct_state(struct nf_conn *ct)
160 if (nf_ct_protonum(ct) == IPPROTO_TCP)
161 flow_offload_fixup_tcp(&ct->proto.tcp);
164 static void flow_offload_fixup_ct(struct nf_conn *ct)
166 flow_offload_fixup_ct_state(ct);
167 flow_offload_fixup_ct_timeout(ct);
170 static void flow_offload_route_release(struct flow_offload *flow)
172 dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_cache);
173 dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_cache);
176 void flow_offload_free(struct flow_offload *flow)
178 switch (flow->type) {
179 case NF_FLOW_OFFLOAD_ROUTE:
180 flow_offload_route_release(flow);
186 kfree_rcu(flow, rcu_head);
188 EXPORT_SYMBOL_GPL(flow_offload_free);
190 static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
192 const struct flow_offload_tuple *tuple = data;
194 return jhash(tuple, offsetof(struct flow_offload_tuple, dir), seed);
197 static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
199 const struct flow_offload_tuple_rhash *tuplehash = data;
201 return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, dir), seed);
204 static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
207 const struct flow_offload_tuple *tuple = arg->key;
208 const struct flow_offload_tuple_rhash *x = ptr;
210 if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, dir)))
216 static const struct rhashtable_params nf_flow_offload_rhash_params = {
217 .head_offset = offsetof(struct flow_offload_tuple_rhash, node),
218 .hashfn = flow_offload_hash,
219 .obj_hashfn = flow_offload_hash_obj,
220 .obj_cmpfn = flow_offload_hash_cmp,
221 .automatic_shrinking = true,
224 int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow)
228 flow->timeout = nf_flowtable_time_stamp + NF_FLOW_TIMEOUT;
230 err = rhashtable_insert_fast(&flow_table->rhashtable,
231 &flow->tuplehash[0].node,
232 nf_flow_offload_rhash_params);
236 err = rhashtable_insert_fast(&flow_table->rhashtable,
237 &flow->tuplehash[1].node,
238 nf_flow_offload_rhash_params);
240 rhashtable_remove_fast(&flow_table->rhashtable,
241 &flow->tuplehash[0].node,
242 nf_flow_offload_rhash_params);
246 if (nf_flowtable_hw_offload(flow_table)) {
247 __set_bit(NF_FLOW_HW, &flow->flags);
248 nf_flow_offload_add(flow_table, flow);
253 EXPORT_SYMBOL_GPL(flow_offload_add);
255 static inline bool nf_flow_has_expired(const struct flow_offload *flow)
257 return nf_flow_timeout_delta(flow->timeout) <= 0;
260 static void flow_offload_del(struct nf_flowtable *flow_table,
261 struct flow_offload *flow)
263 rhashtable_remove_fast(&flow_table->rhashtable,
264 &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
265 nf_flow_offload_rhash_params);
266 rhashtable_remove_fast(&flow_table->rhashtable,
267 &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
268 nf_flow_offload_rhash_params);
270 clear_bit(IPS_OFFLOAD_BIT, &flow->ct->status);
272 if (nf_flow_has_expired(flow))
273 flow_offload_fixup_ct(flow->ct);
274 else if (test_bit(NF_FLOW_TEARDOWN, &flow->flags))
275 flow_offload_fixup_ct_timeout(flow->ct);
277 flow_offload_free(flow);
280 void flow_offload_teardown(struct flow_offload *flow)
282 set_bit(NF_FLOW_TEARDOWN, &flow->flags);
284 flow_offload_fixup_ct_state(flow->ct);
286 EXPORT_SYMBOL_GPL(flow_offload_teardown);
288 struct flow_offload_tuple_rhash *
289 flow_offload_lookup(struct nf_flowtable *flow_table,
290 struct flow_offload_tuple *tuple)
292 struct flow_offload_tuple_rhash *tuplehash;
293 struct flow_offload *flow;
296 tuplehash = rhashtable_lookup(&flow_table->rhashtable, tuple,
297 nf_flow_offload_rhash_params);
301 dir = tuplehash->tuple.dir;
302 flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
303 if (test_bit(NF_FLOW_TEARDOWN, &flow->flags))
306 if (unlikely(nf_ct_is_dying(flow->ct)))
311 EXPORT_SYMBOL_GPL(flow_offload_lookup);
314 nf_flow_table_iterate(struct nf_flowtable *flow_table,
315 void (*iter)(struct flow_offload *flow, void *data),
318 struct flow_offload_tuple_rhash *tuplehash;
319 struct rhashtable_iter hti;
320 struct flow_offload *flow;
323 rhashtable_walk_enter(&flow_table->rhashtable, &hti);
324 rhashtable_walk_start(&hti);
326 while ((tuplehash = rhashtable_walk_next(&hti))) {
327 if (IS_ERR(tuplehash)) {
328 if (PTR_ERR(tuplehash) != -EAGAIN) {
329 err = PTR_ERR(tuplehash);
334 if (tuplehash->tuple.dir)
337 flow = container_of(tuplehash, struct flow_offload, tuplehash[0]);
341 rhashtable_walk_stop(&hti);
342 rhashtable_walk_exit(&hti);
347 static void nf_flow_offload_gc_step(struct flow_offload *flow, void *data)
349 struct nf_flowtable *flow_table = data;
351 if (nf_flow_has_expired(flow) || nf_ct_is_dying(flow->ct) ||
352 test_bit(NF_FLOW_TEARDOWN, &flow->flags)) {
353 if (test_bit(NF_FLOW_HW, &flow->flags)) {
354 if (!test_bit(NF_FLOW_HW_DYING, &flow->flags))
355 nf_flow_offload_del(flow_table, flow);
356 else if (test_bit(NF_FLOW_HW_DEAD, &flow->flags))
357 flow_offload_del(flow_table, flow);
359 flow_offload_del(flow_table, flow);
361 } else if (test_bit(NF_FLOW_HW, &flow->flags)) {
362 nf_flow_offload_stats(flow_table, flow);
366 static void nf_flow_offload_work_gc(struct work_struct *work)
368 struct nf_flowtable *flow_table;
370 flow_table = container_of(work, struct nf_flowtable, gc_work.work);
371 nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
372 queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ);
375 static int nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff,
376 __be16 port, __be16 new_port)
380 if (!pskb_may_pull(skb, thoff + sizeof(*tcph)) ||
381 skb_try_make_writable(skb, thoff + sizeof(*tcph)))
384 tcph = (void *)(skb_network_header(skb) + thoff);
385 inet_proto_csum_replace2(&tcph->check, skb, port, new_port, true);
390 static int nf_flow_nat_port_udp(struct sk_buff *skb, unsigned int thoff,
391 __be16 port, __be16 new_port)
395 if (!pskb_may_pull(skb, thoff + sizeof(*udph)) ||
396 skb_try_make_writable(skb, thoff + sizeof(*udph)))
399 udph = (void *)(skb_network_header(skb) + thoff);
400 if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
401 inet_proto_csum_replace2(&udph->check, skb, port,
404 udph->check = CSUM_MANGLED_0;
410 static int nf_flow_nat_port(struct sk_buff *skb, unsigned int thoff,
411 u8 protocol, __be16 port, __be16 new_port)
415 if (nf_flow_nat_port_tcp(skb, thoff, port, new_port) < 0)
419 if (nf_flow_nat_port_udp(skb, thoff, port, new_port) < 0)
427 int nf_flow_snat_port(const struct flow_offload *flow,
428 struct sk_buff *skb, unsigned int thoff,
429 u8 protocol, enum flow_offload_tuple_dir dir)
431 struct flow_ports *hdr;
432 __be16 port, new_port;
434 if (!pskb_may_pull(skb, thoff + sizeof(*hdr)) ||
435 skb_try_make_writable(skb, thoff + sizeof(*hdr)))
438 hdr = (void *)(skb_network_header(skb) + thoff);
441 case FLOW_OFFLOAD_DIR_ORIGINAL:
443 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port;
444 hdr->source = new_port;
446 case FLOW_OFFLOAD_DIR_REPLY:
448 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port;
449 hdr->dest = new_port;
455 return nf_flow_nat_port(skb, thoff, protocol, port, new_port);
457 EXPORT_SYMBOL_GPL(nf_flow_snat_port);
459 int nf_flow_dnat_port(const struct flow_offload *flow,
460 struct sk_buff *skb, unsigned int thoff,
461 u8 protocol, enum flow_offload_tuple_dir dir)
463 struct flow_ports *hdr;
464 __be16 port, new_port;
466 if (!pskb_may_pull(skb, thoff + sizeof(*hdr)) ||
467 skb_try_make_writable(skb, thoff + sizeof(*hdr)))
470 hdr = (void *)(skb_network_header(skb) + thoff);
473 case FLOW_OFFLOAD_DIR_ORIGINAL:
475 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port;
476 hdr->dest = new_port;
478 case FLOW_OFFLOAD_DIR_REPLY:
480 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port;
481 hdr->source = new_port;
487 return nf_flow_nat_port(skb, thoff, protocol, port, new_port);
489 EXPORT_SYMBOL_GPL(nf_flow_dnat_port);
491 int nf_flow_table_init(struct nf_flowtable *flowtable)
495 INIT_DEFERRABLE_WORK(&flowtable->gc_work, nf_flow_offload_work_gc);
496 flow_block_init(&flowtable->flow_block);
498 err = rhashtable_init(&flowtable->rhashtable,
499 &nf_flow_offload_rhash_params);
503 queue_delayed_work(system_power_efficient_wq,
504 &flowtable->gc_work, HZ);
506 mutex_lock(&flowtable_lock);
507 list_add(&flowtable->list, &flowtables);
508 mutex_unlock(&flowtable_lock);
512 EXPORT_SYMBOL_GPL(nf_flow_table_init);
514 static void nf_flow_table_do_cleanup(struct flow_offload *flow, void *data)
516 struct net_device *dev = data;
519 flow_offload_teardown(flow);
523 if (net_eq(nf_ct_net(flow->ct), dev_net(dev)) &&
524 (flow->tuplehash[0].tuple.iifidx == dev->ifindex ||
525 flow->tuplehash[1].tuple.iifidx == dev->ifindex))
526 flow_offload_teardown(flow);
529 static void nf_flow_table_iterate_cleanup(struct nf_flowtable *flowtable,
530 struct net_device *dev)
532 nf_flow_table_iterate(flowtable, nf_flow_table_do_cleanup, dev);
533 flush_delayed_work(&flowtable->gc_work);
534 nf_flow_table_offload_flush(flowtable);
537 void nf_flow_table_cleanup(struct net_device *dev)
539 struct nf_flowtable *flowtable;
541 mutex_lock(&flowtable_lock);
542 list_for_each_entry(flowtable, &flowtables, list)
543 nf_flow_table_iterate_cleanup(flowtable, dev);
544 mutex_unlock(&flowtable_lock);
546 EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);
548 void nf_flow_table_free(struct nf_flowtable *flow_table)
550 mutex_lock(&flowtable_lock);
551 list_del(&flow_table->list);
552 mutex_unlock(&flowtable_lock);
553 cancel_delayed_work_sync(&flow_table->gc_work);
554 nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
555 nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
556 nf_flow_table_offload_flush(flow_table);
557 rhashtable_destroy(&flow_table->rhashtable);
559 EXPORT_SYMBOL_GPL(nf_flow_table_free);
561 static int __init nf_flow_table_module_init(void)
563 return nf_flow_table_offload_init();
566 static void __exit nf_flow_table_module_exit(void)
568 nf_flow_table_offload_exit();
571 module_init(nf_flow_table_module_init);
572 module_exit(nf_flow_table_module_exit);
574 MODULE_LICENSE("GPL");
575 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");