1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/kernel.h>
3 #include <linux/module.h>
4 #include <linux/init.h>
5 #include <linux/netlink.h>
6 #include <linux/netfilter.h>
7 #include <linux/workqueue.h>
8 #include <linux/spinlock.h>
9 #include <linux/netfilter/nf_conntrack_common.h>
10 #include <linux/netfilter/nf_tables.h>
11 #include <net/ip.h> /* for ipv4 options. */
12 #include <net/netfilter/nf_tables.h>
13 #include <net/netfilter/nf_tables_core.h>
14 #include <net/netfilter/nf_conntrack_core.h>
15 #include <net/netfilter/nf_conntrack_extend.h>
16 #include <net/netfilter/nf_flow_table.h>
18 struct nft_flow_offload {
19 struct nft_flowtable *flowtable;
22 static enum flow_offload_xmit_type nft_xmit_type(struct dst_entry *dst)
25 return FLOW_OFFLOAD_XMIT_XFRM;
27 return FLOW_OFFLOAD_XMIT_NEIGH;
30 static void nft_default_forward_path(struct nf_flow_route *route,
31 struct dst_entry *dst_cache,
32 enum ip_conntrack_dir dir)
34 route->tuple[!dir].in.ifindex = dst_cache->dev->ifindex;
35 route->tuple[dir].dst = dst_cache;
36 route->tuple[dir].xmit_type = nft_xmit_type(dst_cache);
39 static int nft_dev_fill_forward_path(const struct nf_flow_route *route,
40 const struct dst_entry *dst_cache,
41 const struct nf_conn *ct,
42 enum ip_conntrack_dir dir, u8 *ha,
43 struct net_device_path_stack *stack)
45 const void *daddr = &ct->tuplehash[!dir].tuple.src.u3;
46 struct net_device *dev = dst_cache->dev;
50 n = dst_neigh_lookup(dst_cache, daddr);
54 read_lock_bh(&n->lock);
55 nud_state = n->nud_state;
56 ether_addr_copy(ha, n->ha);
57 read_unlock_bh(&n->lock);
60 if (!(nud_state & NUD_VALID))
63 return dev_fill_forward_path(dev, ha, stack);
66 struct nft_forward_info {
67 const struct net_device *indev;
68 const struct net_device *outdev;
69 const struct net_device *hw_outdev;
73 } encap[NF_FLOW_TABLE_ENCAP_MAX];
76 u8 h_source[ETH_ALEN];
78 enum flow_offload_xmit_type xmit_type;
81 static bool nft_is_valid_ether_device(const struct net_device *dev)
83 if (!dev || (dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
84 dev->addr_len != ETH_ALEN || !is_valid_ether_addr(dev->dev_addr))
90 static void nft_dev_path_info(const struct net_device_path_stack *stack,
91 struct nft_forward_info *info,
92 unsigned char *ha, struct nf_flowtable *flowtable)
94 const struct net_device_path *path;
97 memcpy(info->h_dest, ha, ETH_ALEN);
99 for (i = 0; i < stack->num_paths; i++) {
100 path = &stack->path[i];
101 switch (path->type) {
102 case DEV_PATH_ETHERNET:
106 info->indev = path->dev;
107 if (is_zero_ether_addr(info->h_source))
108 memcpy(info->h_source, path->dev->dev_addr, ETH_ALEN);
110 if (path->type == DEV_PATH_ETHERNET)
112 if (path->type == DEV_PATH_DSA) {
113 i = stack->num_paths;
117 /* DEV_PATH_VLAN and DEV_PATH_PPPOE */
118 if (info->num_encaps >= NF_FLOW_TABLE_ENCAP_MAX) {
122 info->outdev = path->dev;
123 info->encap[info->num_encaps].id = path->encap.id;
124 info->encap[info->num_encaps].proto = path->encap.proto;
126 if (path->type == DEV_PATH_PPPOE)
127 memcpy(info->h_dest, path->encap.h_dest, ETH_ALEN);
129 case DEV_PATH_BRIDGE:
130 if (is_zero_ether_addr(info->h_source))
131 memcpy(info->h_source, path->dev->dev_addr, ETH_ALEN);
133 switch (path->bridge.vlan_mode) {
134 case DEV_PATH_BR_VLAN_UNTAG_HW:
135 info->ingress_vlans |= BIT(info->num_encaps - 1);
137 case DEV_PATH_BR_VLAN_TAG:
138 info->encap[info->num_encaps].id = path->bridge.vlan_id;
139 info->encap[info->num_encaps].proto = path->bridge.vlan_proto;
142 case DEV_PATH_BR_VLAN_UNTAG:
145 case DEV_PATH_BR_VLAN_KEEP:
148 info->xmit_type = FLOW_OFFLOAD_XMIT_DIRECT;
156 info->outdev = info->indev;
158 info->hw_outdev = info->indev;
160 if (nf_flowtable_hw_offload(flowtable) &&
161 nft_is_valid_ether_device(info->indev))
162 info->xmit_type = FLOW_OFFLOAD_XMIT_DIRECT;
165 static bool nft_flowtable_find_dev(const struct net_device *dev,
166 struct nft_flowtable *ft)
168 struct nft_hook *hook;
171 list_for_each_entry_rcu(hook, &ft->hook_list, list) {
172 if (hook->ops.dev != dev)
182 static void nft_dev_forward_path(struct nf_flow_route *route,
183 const struct nf_conn *ct,
184 enum ip_conntrack_dir dir,
185 struct nft_flowtable *ft)
187 const struct dst_entry *dst = route->tuple[dir].dst;
188 struct net_device_path_stack stack;
189 struct nft_forward_info info = {};
190 unsigned char ha[ETH_ALEN];
193 if (nft_dev_fill_forward_path(route, dst, ct, dir, ha, &stack) >= 0)
194 nft_dev_path_info(&stack, &info, ha, &ft->data);
196 if (!info.indev || !nft_flowtable_find_dev(info.indev, ft))
199 route->tuple[!dir].in.ifindex = info.indev->ifindex;
200 for (i = 0; i < info.num_encaps; i++) {
201 route->tuple[!dir].in.encap[i].id = info.encap[i].id;
202 route->tuple[!dir].in.encap[i].proto = info.encap[i].proto;
204 route->tuple[!dir].in.num_encaps = info.num_encaps;
205 route->tuple[!dir].in.ingress_vlans = info.ingress_vlans;
207 if (info.xmit_type == FLOW_OFFLOAD_XMIT_DIRECT) {
208 memcpy(route->tuple[dir].out.h_source, info.h_source, ETH_ALEN);
209 memcpy(route->tuple[dir].out.h_dest, info.h_dest, ETH_ALEN);
210 route->tuple[dir].out.ifindex = info.outdev->ifindex;
211 route->tuple[dir].out.hw_ifindex = info.hw_outdev->ifindex;
212 route->tuple[dir].xmit_type = info.xmit_type;
216 static int nft_flow_route(const struct nft_pktinfo *pkt,
217 const struct nf_conn *ct,
218 struct nf_flow_route *route,
219 enum ip_conntrack_dir dir,
220 struct nft_flowtable *ft)
222 struct dst_entry *this_dst = skb_dst(pkt->skb);
223 struct dst_entry *other_dst = NULL;
226 memset(&fl, 0, sizeof(fl));
227 switch (nft_pf(pkt)) {
229 fl.u.ip4.daddr = ct->tuplehash[dir].tuple.src.u3.ip;
230 fl.u.ip4.flowi4_oif = nft_in(pkt)->ifindex;
233 fl.u.ip6.daddr = ct->tuplehash[dir].tuple.src.u3.in6;
234 fl.u.ip6.flowi6_oif = nft_in(pkt)->ifindex;
238 nf_route(nft_net(pkt), &other_dst, &fl, false, nft_pf(pkt));
242 nft_default_forward_path(route, this_dst, dir);
243 nft_default_forward_path(route, other_dst, !dir);
245 if (route->tuple[dir].xmit_type == FLOW_OFFLOAD_XMIT_NEIGH &&
246 route->tuple[!dir].xmit_type == FLOW_OFFLOAD_XMIT_NEIGH) {
247 nft_dev_forward_path(route, ct, dir, ft);
248 nft_dev_forward_path(route, ct, !dir, ft);
254 static bool nft_flow_offload_skip(struct sk_buff *skb, int family)
256 if (skb_sec_path(skb))
259 if (family == NFPROTO_IPV4) {
260 const struct ip_options *opt;
262 opt = &(IPCB(skb)->opt);
264 if (unlikely(opt->optlen))
271 static void nft_flow_offload_eval(const struct nft_expr *expr,
272 struct nft_regs *regs,
273 const struct nft_pktinfo *pkt)
275 struct nft_flow_offload *priv = nft_expr_priv(expr);
276 struct nf_flowtable *flowtable = &priv->flowtable->data;
277 struct tcphdr _tcph, *tcph = NULL;
278 struct nf_flow_route route = {};
279 enum ip_conntrack_info ctinfo;
280 struct flow_offload *flow;
281 enum ip_conntrack_dir dir;
285 if (nft_flow_offload_skip(pkt->skb, nft_pf(pkt)))
288 ct = nf_ct_get(pkt->skb, &ctinfo);
292 switch (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum) {
294 tcph = skb_header_pointer(pkt->skb, nft_thoff(pkt),
295 sizeof(_tcph), &_tcph);
296 if (unlikely(!tcph || tcph->fin || tcph->rst))
301 #ifdef CONFIG_NF_CT_PROTO_GRE
303 struct nf_conntrack_tuple *tuple;
305 if (ct->status & IPS_NAT_MASK)
307 tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
308 /* No support for GRE v1 */
309 if (tuple->src.u.gre.key || tuple->dst.u.gre.key)
318 if (nf_ct_ext_exist(ct, NF_CT_EXT_HELPER) ||
319 ct->status & (IPS_SEQ_ADJUST | IPS_NAT_CLASH))
322 if (!nf_ct_is_confirmed(ct))
325 if (test_and_set_bit(IPS_OFFLOAD_BIT, &ct->status))
328 dir = CTINFO2DIR(ctinfo);
329 if (nft_flow_route(pkt, ct, &route, dir, priv->flowtable) < 0)
332 flow = flow_offload_alloc(ct);
336 if (flow_offload_route_init(flow, &route) < 0)
340 ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
341 ct->proto.tcp.seen[1].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
344 ret = flow_offload_add(flowtable, flow);
348 dst_release(route.tuple[!dir].dst);
352 flow_offload_free(flow);
354 dst_release(route.tuple[!dir].dst);
356 clear_bit(IPS_OFFLOAD_BIT, &ct->status);
358 regs->verdict.code = NFT_BREAK;
361 static int nft_flow_offload_validate(const struct nft_ctx *ctx,
362 const struct nft_expr *expr,
363 const struct nft_data **data)
365 unsigned int hook_mask = (1 << NF_INET_FORWARD);
367 return nft_chain_validate_hooks(ctx->chain, hook_mask);
370 static const struct nla_policy nft_flow_offload_policy[NFTA_FLOW_MAX + 1] = {
371 [NFTA_FLOW_TABLE_NAME] = { .type = NLA_STRING,
372 .len = NFT_NAME_MAXLEN - 1 },
375 static int nft_flow_offload_init(const struct nft_ctx *ctx,
376 const struct nft_expr *expr,
377 const struct nlattr * const tb[])
379 struct nft_flow_offload *priv = nft_expr_priv(expr);
380 u8 genmask = nft_genmask_next(ctx->net);
381 struct nft_flowtable *flowtable;
383 if (!tb[NFTA_FLOW_TABLE_NAME])
386 flowtable = nft_flowtable_lookup(ctx->table, tb[NFTA_FLOW_TABLE_NAME],
388 if (IS_ERR(flowtable))
389 return PTR_ERR(flowtable);
391 priv->flowtable = flowtable;
394 return nf_ct_netns_get(ctx->net, ctx->family);
397 static void nft_flow_offload_deactivate(const struct nft_ctx *ctx,
398 const struct nft_expr *expr,
399 enum nft_trans_phase phase)
401 struct nft_flow_offload *priv = nft_expr_priv(expr);
403 nf_tables_deactivate_flowtable(ctx, priv->flowtable, phase);
406 static void nft_flow_offload_activate(const struct nft_ctx *ctx,
407 const struct nft_expr *expr)
409 struct nft_flow_offload *priv = nft_expr_priv(expr);
411 priv->flowtable->use++;
414 static void nft_flow_offload_destroy(const struct nft_ctx *ctx,
415 const struct nft_expr *expr)
417 nf_ct_netns_put(ctx->net, ctx->family);
420 static int nft_flow_offload_dump(struct sk_buff *skb, const struct nft_expr *expr)
422 struct nft_flow_offload *priv = nft_expr_priv(expr);
424 if (nla_put_string(skb, NFTA_FLOW_TABLE_NAME, priv->flowtable->name))
425 goto nla_put_failure;
433 static struct nft_expr_type nft_flow_offload_type;
434 static const struct nft_expr_ops nft_flow_offload_ops = {
435 .type = &nft_flow_offload_type,
436 .size = NFT_EXPR_SIZE(sizeof(struct nft_flow_offload)),
437 .eval = nft_flow_offload_eval,
438 .init = nft_flow_offload_init,
439 .activate = nft_flow_offload_activate,
440 .deactivate = nft_flow_offload_deactivate,
441 .destroy = nft_flow_offload_destroy,
442 .validate = nft_flow_offload_validate,
443 .dump = nft_flow_offload_dump,
444 .reduce = NFT_REDUCE_READONLY,
447 static struct nft_expr_type nft_flow_offload_type __read_mostly = {
448 .name = "flow_offload",
449 .ops = &nft_flow_offload_ops,
450 .policy = nft_flow_offload_policy,
451 .maxattr = NFTA_FLOW_MAX,
452 .owner = THIS_MODULE,
455 static int flow_offload_netdev_event(struct notifier_block *this,
456 unsigned long event, void *ptr)
458 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
460 if (event != NETDEV_DOWN)
463 nf_flow_table_cleanup(dev);
468 static struct notifier_block flow_offload_netdev_notifier = {
469 .notifier_call = flow_offload_netdev_event,
472 static int __init nft_flow_offload_module_init(void)
476 err = register_netdevice_notifier(&flow_offload_netdev_notifier);
480 err = nft_register_expr(&nft_flow_offload_type);
487 unregister_netdevice_notifier(&flow_offload_netdev_notifier);
492 static void __exit nft_flow_offload_module_exit(void)
494 nft_unregister_expr(&nft_flow_offload_type);
495 unregister_netdevice_notifier(&flow_offload_netdev_notifier);
498 module_init(nft_flow_offload_module_init);
499 module_exit(nft_flow_offload_module_exit);
501 MODULE_LICENSE("GPL");
502 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
503 MODULE_ALIAS_NFT_EXPR("flow_offload");
504 MODULE_DESCRIPTION("nftables hardware flow offload module");