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 flow->flags |= FLOW_OFFLOAD_SNAT;
65 if (ct->status & IPS_DST_NAT)
66 flow->flags |= FLOW_OFFLOAD_DNAT;
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 inline __s32 nf_flow_timeout_delta(unsigned int timeout)
139 return (__s32)(timeout - (u32)jiffies);
142 static void flow_offload_fixup_ct_timeout(struct nf_conn *ct)
144 const struct nf_conntrack_l4proto *l4proto;
145 int l4num = nf_ct_protonum(ct);
146 unsigned int timeout;
148 l4proto = nf_ct_l4proto_find(l4num);
152 if (l4num == IPPROTO_TCP)
153 timeout = NF_FLOWTABLE_TCP_PICKUP_TIMEOUT;
154 else if (l4num == IPPROTO_UDP)
155 timeout = NF_FLOWTABLE_UDP_PICKUP_TIMEOUT;
159 if (nf_flow_timeout_delta(ct->timeout) > (__s32)timeout)
160 ct->timeout = nfct_time_stamp + timeout;
163 static void flow_offload_fixup_ct_state(struct nf_conn *ct)
165 if (nf_ct_protonum(ct) == IPPROTO_TCP)
166 flow_offload_fixup_tcp(&ct->proto.tcp);
169 static void flow_offload_fixup_ct(struct nf_conn *ct)
171 flow_offload_fixup_ct_state(ct);
172 flow_offload_fixup_ct_timeout(ct);
175 static void flow_offload_route_release(struct flow_offload *flow)
177 dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_cache);
178 dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_cache);
181 void flow_offload_free(struct flow_offload *flow)
183 switch (flow->type) {
184 case NF_FLOW_OFFLOAD_ROUTE:
185 flow_offload_route_release(flow);
190 if (flow->flags & FLOW_OFFLOAD_DYING)
191 nf_ct_delete(flow->ct, 0, 0);
193 kfree_rcu(flow, rcu_head);
195 EXPORT_SYMBOL_GPL(flow_offload_free);
197 static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
199 const struct flow_offload_tuple *tuple = data;
201 return jhash(tuple, offsetof(struct flow_offload_tuple, dir), seed);
204 static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
206 const struct flow_offload_tuple_rhash *tuplehash = data;
208 return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, dir), seed);
211 static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
214 const struct flow_offload_tuple *tuple = arg->key;
215 const struct flow_offload_tuple_rhash *x = ptr;
217 if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, dir)))
223 static const struct rhashtable_params nf_flow_offload_rhash_params = {
224 .head_offset = offsetof(struct flow_offload_tuple_rhash, node),
225 .hashfn = flow_offload_hash,
226 .obj_hashfn = flow_offload_hash_obj,
227 .obj_cmpfn = flow_offload_hash_cmp,
228 .automatic_shrinking = true,
231 int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow)
235 flow->timeout = (u32)jiffies + NF_FLOW_TIMEOUT;
237 err = rhashtable_insert_fast(&flow_table->rhashtable,
238 &flow->tuplehash[0].node,
239 nf_flow_offload_rhash_params);
243 err = rhashtable_insert_fast(&flow_table->rhashtable,
244 &flow->tuplehash[1].node,
245 nf_flow_offload_rhash_params);
247 rhashtable_remove_fast(&flow_table->rhashtable,
248 &flow->tuplehash[0].node,
249 nf_flow_offload_rhash_params);
253 if (flow_table->flags & NF_FLOWTABLE_HW_OFFLOAD)
254 nf_flow_offload_add(flow_table, flow);
258 EXPORT_SYMBOL_GPL(flow_offload_add);
260 static inline bool nf_flow_has_expired(const struct flow_offload *flow)
262 return nf_flow_timeout_delta(flow->timeout) <= 0;
265 static void flow_offload_del(struct nf_flowtable *flow_table,
266 struct flow_offload *flow)
268 rhashtable_remove_fast(&flow_table->rhashtable,
269 &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
270 nf_flow_offload_rhash_params);
271 rhashtable_remove_fast(&flow_table->rhashtable,
272 &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
273 nf_flow_offload_rhash_params);
275 clear_bit(IPS_OFFLOAD_BIT, &flow->ct->status);
277 if (nf_flow_has_expired(flow))
278 flow_offload_fixup_ct(flow->ct);
279 else if (flow->flags & FLOW_OFFLOAD_TEARDOWN)
280 flow_offload_fixup_ct_timeout(flow->ct);
282 flow_offload_free(flow);
285 void flow_offload_teardown(struct flow_offload *flow)
287 flow->flags |= FLOW_OFFLOAD_TEARDOWN;
289 flow_offload_fixup_ct_state(flow->ct);
291 EXPORT_SYMBOL_GPL(flow_offload_teardown);
293 struct flow_offload_tuple_rhash *
294 flow_offload_lookup(struct nf_flowtable *flow_table,
295 struct flow_offload_tuple *tuple)
297 struct flow_offload_tuple_rhash *tuplehash;
298 struct flow_offload *flow;
301 tuplehash = rhashtable_lookup(&flow_table->rhashtable, tuple,
302 nf_flow_offload_rhash_params);
306 dir = tuplehash->tuple.dir;
307 flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
308 if (flow->flags & (FLOW_OFFLOAD_DYING | FLOW_OFFLOAD_TEARDOWN))
311 if (unlikely(nf_ct_is_dying(flow->ct)))
316 EXPORT_SYMBOL_GPL(flow_offload_lookup);
319 nf_flow_table_iterate(struct nf_flowtable *flow_table,
320 void (*iter)(struct flow_offload *flow, void *data),
323 struct flow_offload_tuple_rhash *tuplehash;
324 struct rhashtable_iter hti;
325 struct flow_offload *flow;
328 rhashtable_walk_enter(&flow_table->rhashtable, &hti);
329 rhashtable_walk_start(&hti);
331 while ((tuplehash = rhashtable_walk_next(&hti))) {
332 if (IS_ERR(tuplehash)) {
333 if (PTR_ERR(tuplehash) != -EAGAIN) {
334 err = PTR_ERR(tuplehash);
339 if (tuplehash->tuple.dir)
342 flow = container_of(tuplehash, struct flow_offload, tuplehash[0]);
346 rhashtable_walk_stop(&hti);
347 rhashtable_walk_exit(&hti);
352 static void nf_flow_offload_gc_step(struct flow_offload *flow, void *data)
354 struct nf_flowtable *flow_table = data;
356 if (flow->flags & FLOW_OFFLOAD_HW)
357 nf_flow_offload_stats(flow_table, flow);
359 if (nf_flow_has_expired(flow) || nf_ct_is_dying(flow->ct) ||
360 (flow->flags & (FLOW_OFFLOAD_DYING | FLOW_OFFLOAD_TEARDOWN))) {
361 if (flow->flags & FLOW_OFFLOAD_HW) {
362 if (!(flow->flags & FLOW_OFFLOAD_HW_DYING))
363 nf_flow_offload_del(flow_table, flow);
364 else if (flow->flags & FLOW_OFFLOAD_HW_DEAD)
365 flow_offload_del(flow_table, flow);
367 flow_offload_del(flow_table, flow);
372 static void nf_flow_offload_work_gc(struct work_struct *work)
374 struct nf_flowtable *flow_table;
376 flow_table = container_of(work, struct nf_flowtable, gc_work.work);
377 nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
378 queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ);
381 static int nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff,
382 __be16 port, __be16 new_port)
386 if (!pskb_may_pull(skb, thoff + sizeof(*tcph)) ||
387 skb_try_make_writable(skb, thoff + sizeof(*tcph)))
390 tcph = (void *)(skb_network_header(skb) + thoff);
391 inet_proto_csum_replace2(&tcph->check, skb, port, new_port, true);
396 static int nf_flow_nat_port_udp(struct sk_buff *skb, unsigned int thoff,
397 __be16 port, __be16 new_port)
401 if (!pskb_may_pull(skb, thoff + sizeof(*udph)) ||
402 skb_try_make_writable(skb, thoff + sizeof(*udph)))
405 udph = (void *)(skb_network_header(skb) + thoff);
406 if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
407 inet_proto_csum_replace2(&udph->check, skb, port,
410 udph->check = CSUM_MANGLED_0;
416 static int nf_flow_nat_port(struct sk_buff *skb, unsigned int thoff,
417 u8 protocol, __be16 port, __be16 new_port)
421 if (nf_flow_nat_port_tcp(skb, thoff, port, new_port) < 0)
425 if (nf_flow_nat_port_udp(skb, thoff, port, new_port) < 0)
433 int nf_flow_snat_port(const struct flow_offload *flow,
434 struct sk_buff *skb, unsigned int thoff,
435 u8 protocol, enum flow_offload_tuple_dir dir)
437 struct flow_ports *hdr;
438 __be16 port, new_port;
440 if (!pskb_may_pull(skb, thoff + sizeof(*hdr)) ||
441 skb_try_make_writable(skb, thoff + sizeof(*hdr)))
444 hdr = (void *)(skb_network_header(skb) + thoff);
447 case FLOW_OFFLOAD_DIR_ORIGINAL:
449 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port;
450 hdr->source = new_port;
452 case FLOW_OFFLOAD_DIR_REPLY:
454 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port;
455 hdr->dest = new_port;
461 return nf_flow_nat_port(skb, thoff, protocol, port, new_port);
463 EXPORT_SYMBOL_GPL(nf_flow_snat_port);
465 int nf_flow_dnat_port(const struct flow_offload *flow,
466 struct sk_buff *skb, unsigned int thoff,
467 u8 protocol, enum flow_offload_tuple_dir dir)
469 struct flow_ports *hdr;
470 __be16 port, new_port;
472 if (!pskb_may_pull(skb, thoff + sizeof(*hdr)) ||
473 skb_try_make_writable(skb, thoff + sizeof(*hdr)))
476 hdr = (void *)(skb_network_header(skb) + thoff);
479 case FLOW_OFFLOAD_DIR_ORIGINAL:
481 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port;
482 hdr->dest = new_port;
484 case FLOW_OFFLOAD_DIR_REPLY:
486 new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port;
487 hdr->source = new_port;
493 return nf_flow_nat_port(skb, thoff, protocol, port, new_port);
495 EXPORT_SYMBOL_GPL(nf_flow_dnat_port);
497 int nf_flow_table_init(struct nf_flowtable *flowtable)
501 INIT_DEFERRABLE_WORK(&flowtable->gc_work, nf_flow_offload_work_gc);
502 flow_block_init(&flowtable->flow_block);
504 err = rhashtable_init(&flowtable->rhashtable,
505 &nf_flow_offload_rhash_params);
509 queue_delayed_work(system_power_efficient_wq,
510 &flowtable->gc_work, HZ);
512 mutex_lock(&flowtable_lock);
513 list_add(&flowtable->list, &flowtables);
514 mutex_unlock(&flowtable_lock);
518 EXPORT_SYMBOL_GPL(nf_flow_table_init);
520 static void nf_flow_table_do_cleanup(struct flow_offload *flow, void *data)
522 struct net_device *dev = data;
525 flow_offload_teardown(flow);
529 if (net_eq(nf_ct_net(flow->ct), dev_net(dev)) &&
530 (flow->tuplehash[0].tuple.iifidx == dev->ifindex ||
531 flow->tuplehash[1].tuple.iifidx == dev->ifindex))
532 flow_offload_dead(flow);
535 static void nf_flow_table_iterate_cleanup(struct nf_flowtable *flowtable,
536 struct net_device *dev)
538 nf_flow_table_offload_flush(flowtable);
539 nf_flow_table_iterate(flowtable, nf_flow_table_do_cleanup, dev);
540 flush_delayed_work(&flowtable->gc_work);
543 void nf_flow_table_cleanup(struct net_device *dev)
545 struct nf_flowtable *flowtable;
547 mutex_lock(&flowtable_lock);
548 list_for_each_entry(flowtable, &flowtables, list)
549 nf_flow_table_iterate_cleanup(flowtable, dev);
550 mutex_unlock(&flowtable_lock);
552 EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);
554 void nf_flow_table_free(struct nf_flowtable *flow_table)
556 mutex_lock(&flowtable_lock);
557 list_del(&flow_table->list);
558 mutex_unlock(&flowtable_lock);
559 cancel_delayed_work_sync(&flow_table->gc_work);
560 nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
561 nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
562 rhashtable_destroy(&flow_table->rhashtable);
564 EXPORT_SYMBOL_GPL(nf_flow_table_free);
566 static int __init nf_flow_table_module_init(void)
568 return nf_flow_table_offload_init();
571 static void __exit nf_flow_table_module_exit(void)
573 nf_flow_table_offload_exit();
576 module_init(nf_flow_table_module_init);
577 module_exit(nf_flow_table_module_exit);
579 MODULE_LICENSE("GPL");
580 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");