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/etherdevice.h>
6 #include <linux/netlink.h>
7 #include <linux/netfilter.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>
12 #include <net/inet_dscp.h>
13 #include <net/netfilter/nf_tables.h>
14 #include <net/netfilter/nf_tables_core.h>
15 #include <net/netfilter/nf_conntrack_core.h>
16 #include <net/netfilter/nf_conntrack_extend.h>
17 #include <net/netfilter/nf_flow_table.h>
18
nft_xmit_type(struct dst_entry * dst)19 static enum flow_offload_xmit_type nft_xmit_type(struct dst_entry *dst)
20 {
21 if (dst_xfrm(dst))
22 return FLOW_OFFLOAD_XMIT_XFRM;
23
24 return FLOW_OFFLOAD_XMIT_NEIGH;
25 }
26
nft_default_forward_path(struct nf_flow_route * route,struct dst_entry * dst_cache,enum ip_conntrack_dir dir)27 static void nft_default_forward_path(struct nf_flow_route *route,
28 struct dst_entry *dst_cache,
29 enum ip_conntrack_dir dir)
30 {
31 route->tuple[!dir].in.ifindex = dst_cache->dev->ifindex;
32 route->tuple[dir].dst = dst_cache;
33 route->tuple[dir].xmit_type = nft_xmit_type(dst_cache);
34 }
35
nft_is_valid_ether_device(const struct net_device * dev)36 static bool nft_is_valid_ether_device(const struct net_device *dev)
37 {
38 if (!dev || (dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
39 dev->addr_len != ETH_ALEN || !is_valid_ether_addr(dev->dev_addr))
40 return false;
41
42 return true;
43 }
44
nft_dev_fill_forward_path(const struct nf_flow_route * route,const struct dst_entry * dst_cache,const struct nf_conn * ct,enum ip_conntrack_dir dir,u8 * ha,struct net_device_path_stack * stack)45 static int nft_dev_fill_forward_path(const struct nf_flow_route *route,
46 const struct dst_entry *dst_cache,
47 const struct nf_conn *ct,
48 enum ip_conntrack_dir dir, u8 *ha,
49 struct net_device_path_stack *stack)
50 {
51 const void *daddr = &ct->tuplehash[!dir].tuple.src.u3;
52 struct net_device *dev = dst_cache->dev;
53 struct neighbour *n;
54 u8 nud_state;
55
56 if (!nft_is_valid_ether_device(dev))
57 goto out;
58
59 n = dst_neigh_lookup(dst_cache, daddr);
60 if (!n)
61 return -1;
62
63 read_lock_bh(&n->lock);
64 nud_state = n->nud_state;
65 ether_addr_copy(ha, n->ha);
66 read_unlock_bh(&n->lock);
67 neigh_release(n);
68
69 if (!(nud_state & NUD_VALID))
70 return -1;
71
72 out:
73 return dev_fill_forward_path(dev, ha, stack);
74 }
75
76 struct nft_forward_info {
77 const struct net_device *indev;
78 const struct net_device *outdev;
79 struct id {
80 __u16 id;
81 __be16 proto;
82 } encap[NF_FLOW_TABLE_ENCAP_MAX];
83 u8 num_encaps;
84 struct flow_offload_tunnel tun;
85 u8 num_tuns;
86 u8 ingress_vlans;
87 u8 h_source[ETH_ALEN];
88 u8 h_dest[ETH_ALEN];
89 enum flow_offload_xmit_type xmit_type;
90 };
91
nft_dev_path_info(const struct net_device_path_stack * stack,struct nft_forward_info * info,unsigned char * ha,struct nf_flowtable * flowtable)92 static void nft_dev_path_info(const struct net_device_path_stack *stack,
93 struct nft_forward_info *info,
94 unsigned char *ha, struct nf_flowtable *flowtable)
95 {
96 const struct net_device_path *path;
97 int i;
98
99 memcpy(info->h_dest, ha, ETH_ALEN);
100
101 for (i = 0; i < stack->num_paths; i++) {
102 path = &stack->path[i];
103 switch (path->type) {
104 case DEV_PATH_ETHERNET:
105 case DEV_PATH_DSA:
106 case DEV_PATH_VLAN:
107 case DEV_PATH_PPPOE:
108 case DEV_PATH_TUN:
109 info->indev = path->dev;
110 if (is_zero_ether_addr(info->h_source))
111 memcpy(info->h_source, path->dev->dev_addr, ETH_ALEN);
112
113 if (path->type == DEV_PATH_ETHERNET)
114 break;
115 if (path->type == DEV_PATH_DSA) {
116 i = stack->num_paths;
117 break;
118 }
119
120 /* DEV_PATH_VLAN, DEV_PATH_PPPOE and DEV_PATH_TUN */
121 if (path->type == DEV_PATH_TUN) {
122 if (info->num_tuns) {
123 info->indev = NULL;
124 break;
125 }
126 info->tun.src_v6 = path->tun.src_v6;
127 info->tun.dst_v6 = path->tun.dst_v6;
128 info->tun.l3_proto = path->tun.l3_proto;
129 info->num_tuns++;
130 } else {
131 if (info->num_encaps >= NF_FLOW_TABLE_ENCAP_MAX) {
132 info->indev = NULL;
133 break;
134 }
135 info->encap[info->num_encaps].id =
136 path->encap.id;
137 info->encap[info->num_encaps].proto =
138 path->encap.proto;
139 info->num_encaps++;
140 }
141 if (path->type == DEV_PATH_PPPOE)
142 memcpy(info->h_dest, path->encap.h_dest, ETH_ALEN);
143 break;
144 case DEV_PATH_BRIDGE:
145 if (is_zero_ether_addr(info->h_source))
146 memcpy(info->h_source, path->dev->dev_addr, ETH_ALEN);
147
148 switch (path->bridge.vlan_mode) {
149 case DEV_PATH_BR_VLAN_UNTAG_HW:
150 info->ingress_vlans |= BIT(info->num_encaps - 1);
151 break;
152 case DEV_PATH_BR_VLAN_TAG:
153 if (info->num_encaps >= NF_FLOW_TABLE_ENCAP_MAX) {
154 info->indev = NULL;
155 break;
156 }
157 info->encap[info->num_encaps].id = path->bridge.vlan_id;
158 info->encap[info->num_encaps].proto = path->bridge.vlan_proto;
159 info->num_encaps++;
160 break;
161 case DEV_PATH_BR_VLAN_UNTAG:
162 if (WARN_ON_ONCE(info->num_encaps-- == 0)) {
163 info->indev = NULL;
164 break;
165 }
166 break;
167 case DEV_PATH_BR_VLAN_KEEP:
168 break;
169 }
170 info->xmit_type = FLOW_OFFLOAD_XMIT_DIRECT;
171 break;
172 default:
173 info->indev = NULL;
174 break;
175 }
176 }
177 info->outdev = info->indev;
178
179 if (nf_flowtable_hw_offload(flowtable) &&
180 nft_is_valid_ether_device(info->indev))
181 info->xmit_type = FLOW_OFFLOAD_XMIT_DIRECT;
182 }
183
nft_flowtable_find_dev(const struct net_device * dev,struct nft_flowtable * ft)184 static bool nft_flowtable_find_dev(const struct net_device *dev,
185 struct nft_flowtable *ft)
186 {
187 struct nft_hook *hook;
188 bool found = false;
189
190 list_for_each_entry_rcu(hook, &ft->hook_list, list) {
191 if (!nft_hook_find_ops_rcu(hook, dev))
192 continue;
193
194 found = true;
195 break;
196 }
197
198 return found;
199 }
200
nft_flow_tunnel_update_route(const struct nft_pktinfo * pkt,struct flow_offload_tunnel * tun,struct nf_flow_route * route,enum ip_conntrack_dir dir)201 static int nft_flow_tunnel_update_route(const struct nft_pktinfo *pkt,
202 struct flow_offload_tunnel *tun,
203 struct nf_flow_route *route,
204 enum ip_conntrack_dir dir)
205 {
206 struct dst_entry *cur_dst = route->tuple[dir].dst;
207 struct dst_entry *tun_dst = NULL;
208 struct flowi fl = {};
209
210 switch (nft_pf(pkt)) {
211 case NFPROTO_IPV4:
212 fl.u.ip4.daddr = tun->dst_v4.s_addr;
213 fl.u.ip4.saddr = tun->src_v4.s_addr;
214 fl.u.ip4.flowi4_iif = nft_in(pkt)->ifindex;
215 fl.u.ip4.flowi4_dscp = ip4h_dscp(ip_hdr(pkt->skb));
216 fl.u.ip4.flowi4_mark = pkt->skb->mark;
217 fl.u.ip4.flowi4_flags = FLOWI_FLAG_ANYSRC;
218 break;
219 case NFPROTO_IPV6:
220 fl.u.ip6.daddr = tun->dst_v6;
221 fl.u.ip6.saddr = tun->src_v6;
222 fl.u.ip6.flowi6_iif = nft_in(pkt)->ifindex;
223 fl.u.ip6.flowlabel = ip6_flowinfo(ipv6_hdr(pkt->skb));
224 fl.u.ip6.flowi6_mark = pkt->skb->mark;
225 fl.u.ip6.flowi6_flags = FLOWI_FLAG_ANYSRC;
226 break;
227 }
228
229 nf_route(nft_net(pkt), &tun_dst, &fl, false, nft_pf(pkt));
230 if (!tun_dst)
231 return -ENOENT;
232
233 route->tuple[dir].dst = tun_dst;
234 dst_release(cur_dst);
235
236 return 0;
237 }
238
nft_dev_forward_path(const struct nft_pktinfo * pkt,struct nf_flow_route * route,const struct nf_conn * ct,enum ip_conntrack_dir dir,struct nft_flowtable * ft)239 static void nft_dev_forward_path(const struct nft_pktinfo *pkt,
240 struct nf_flow_route *route,
241 const struct nf_conn *ct,
242 enum ip_conntrack_dir dir,
243 struct nft_flowtable *ft)
244 {
245 const struct dst_entry *dst = route->tuple[dir].dst;
246 struct net_device_path_stack stack;
247 struct nft_forward_info info = {};
248 unsigned char ha[ETH_ALEN];
249 int i;
250
251 if (nft_dev_fill_forward_path(route, dst, ct, dir, ha, &stack) >= 0)
252 nft_dev_path_info(&stack, &info, ha, &ft->data);
253
254 if (info.outdev)
255 route->tuple[dir].out.ifindex = info.outdev->ifindex;
256
257 if (!info.indev || !nft_flowtable_find_dev(info.indev, ft))
258 return;
259
260 route->tuple[!dir].in.ifindex = info.indev->ifindex;
261 for (i = 0; i < info.num_encaps; i++) {
262 route->tuple[!dir].in.encap[i].id = info.encap[i].id;
263 route->tuple[!dir].in.encap[i].proto = info.encap[i].proto;
264 }
265
266 if (info.num_tuns &&
267 !nft_flow_tunnel_update_route(pkt, &info.tun, route, dir)) {
268 route->tuple[!dir].in.tun.src_v6 = info.tun.dst_v6;
269 route->tuple[!dir].in.tun.dst_v6 = info.tun.src_v6;
270 route->tuple[!dir].in.tun.l3_proto = info.tun.l3_proto;
271 route->tuple[!dir].in.num_tuns = info.num_tuns;
272 }
273
274 route->tuple[!dir].in.num_encaps = info.num_encaps;
275 route->tuple[!dir].in.ingress_vlans = info.ingress_vlans;
276
277 if (info.xmit_type == FLOW_OFFLOAD_XMIT_DIRECT) {
278 memcpy(route->tuple[dir].out.h_source, info.h_source, ETH_ALEN);
279 memcpy(route->tuple[dir].out.h_dest, info.h_dest, ETH_ALEN);
280 route->tuple[dir].xmit_type = info.xmit_type;
281 }
282 }
283
nft_flow_route(const struct nft_pktinfo * pkt,const struct nf_conn * ct,struct nf_flow_route * route,enum ip_conntrack_dir dir,struct nft_flowtable * ft)284 int nft_flow_route(const struct nft_pktinfo *pkt, const struct nf_conn *ct,
285 struct nf_flow_route *route, enum ip_conntrack_dir dir,
286 struct nft_flowtable *ft)
287 {
288 struct dst_entry *this_dst = skb_dst(pkt->skb);
289 struct dst_entry *other_dst = NULL;
290 struct flowi fl;
291
292 memset(&fl, 0, sizeof(fl));
293 switch (nft_pf(pkt)) {
294 case NFPROTO_IPV4:
295 fl.u.ip4.daddr = ct->tuplehash[dir].tuple.src.u3.ip;
296 fl.u.ip4.saddr = ct->tuplehash[!dir].tuple.src.u3.ip;
297 fl.u.ip4.flowi4_oif = nft_in(pkt)->ifindex;
298 fl.u.ip4.flowi4_iif = this_dst->dev->ifindex;
299 fl.u.ip4.flowi4_dscp = ip4h_dscp(ip_hdr(pkt->skb));
300 fl.u.ip4.flowi4_mark = pkt->skb->mark;
301 fl.u.ip4.flowi4_flags = FLOWI_FLAG_ANYSRC;
302 break;
303 case NFPROTO_IPV6:
304 fl.u.ip6.daddr = ct->tuplehash[dir].tuple.src.u3.in6;
305 fl.u.ip6.saddr = ct->tuplehash[!dir].tuple.src.u3.in6;
306 fl.u.ip6.flowi6_oif = nft_in(pkt)->ifindex;
307 fl.u.ip6.flowi6_iif = this_dst->dev->ifindex;
308 fl.u.ip6.flowlabel = ip6_flowinfo(ipv6_hdr(pkt->skb));
309 fl.u.ip6.flowi6_mark = pkt->skb->mark;
310 fl.u.ip6.flowi6_flags = FLOWI_FLAG_ANYSRC;
311 break;
312 }
313
314 if (!dst_hold_safe(this_dst))
315 return -ENOENT;
316
317 nf_route(nft_net(pkt), &other_dst, &fl, false, nft_pf(pkt));
318 if (!other_dst) {
319 dst_release(this_dst);
320 return -ENOENT;
321 }
322
323 nft_default_forward_path(route, this_dst, dir);
324 nft_default_forward_path(route, other_dst, !dir);
325
326 if (route->tuple[dir].xmit_type == FLOW_OFFLOAD_XMIT_NEIGH)
327 nft_dev_forward_path(pkt, route, ct, dir, ft);
328 if (route->tuple[!dir].xmit_type == FLOW_OFFLOAD_XMIT_NEIGH)
329 nft_dev_forward_path(pkt, route, ct, !dir, ft);
330
331 return 0;
332 }
333 EXPORT_SYMBOL_GPL(nft_flow_route);
334