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 bool needs_gso_segment;
90 enum flow_offload_xmit_type xmit_type;
91 };
92
nft_dev_path_info(const struct net_device_path_stack * stack,struct nft_forward_info * info,unsigned char * ha,struct nf_flowtable * flowtable)93 static void nft_dev_path_info(const struct net_device_path_stack *stack,
94 struct nft_forward_info *info,
95 unsigned char *ha, struct nf_flowtable *flowtable)
96 {
97 const struct net_device_path *path;
98 int i;
99
100 memcpy(info->h_dest, ha, ETH_ALEN);
101
102 for (i = 0; i < stack->num_paths; i++) {
103 path = &stack->path[i];
104 switch (path->type) {
105 case DEV_PATH_ETHERNET:
106 case DEV_PATH_DSA:
107 case DEV_PATH_VLAN:
108 case DEV_PATH_PPPOE:
109 case DEV_PATH_TUN:
110 info->indev = path->dev;
111 if (is_zero_ether_addr(info->h_source))
112 memcpy(info->h_source, path->dev->dev_addr, ETH_ALEN);
113
114 if (path->type == DEV_PATH_ETHERNET)
115 break;
116 if (path->type == DEV_PATH_DSA) {
117 i = stack->num_paths;
118 break;
119 }
120
121 /* DEV_PATH_VLAN, DEV_PATH_PPPOE and DEV_PATH_TUN */
122 if (path->type == DEV_PATH_TUN) {
123 if (info->num_tuns) {
124 info->indev = NULL;
125 break;
126 }
127 info->tun.src_v6 = path->tun.src_v6;
128 info->tun.dst_v6 = path->tun.dst_v6;
129 info->tun.l3_proto = path->tun.l3_proto;
130 info->num_tuns++;
131 } else {
132 if (info->num_encaps >= NF_FLOW_TABLE_ENCAP_MAX) {
133 info->indev = NULL;
134 break;
135 }
136 info->encap[info->num_encaps].id =
137 path->encap.id;
138 info->encap[info->num_encaps].proto =
139 path->encap.proto;
140 info->num_encaps++;
141 }
142 if (path->type == DEV_PATH_PPPOE) {
143 memcpy(info->h_dest, path->encap.h_dest, ETH_ALEN);
144 info->xmit_type = FLOW_OFFLOAD_XMIT_DIRECT;
145 info->needs_gso_segment = 1;
146 }
147 break;
148 case DEV_PATH_BRIDGE:
149 if (is_zero_ether_addr(info->h_source))
150 memcpy(info->h_source, path->dev->dev_addr, ETH_ALEN);
151
152 switch (path->bridge.vlan_mode) {
153 case DEV_PATH_BR_VLAN_UNTAG_HW:
154 info->ingress_vlans |= BIT(info->num_encaps - 1);
155 break;
156 case DEV_PATH_BR_VLAN_TAG:
157 if (info->num_encaps >= NF_FLOW_TABLE_ENCAP_MAX) {
158 info->indev = NULL;
159 break;
160 }
161 info->encap[info->num_encaps].id = path->bridge.vlan_id;
162 info->encap[info->num_encaps].proto = path->bridge.vlan_proto;
163 info->num_encaps++;
164 break;
165 case DEV_PATH_BR_VLAN_UNTAG:
166 if (WARN_ON_ONCE(info->num_encaps-- == 0)) {
167 info->indev = NULL;
168 break;
169 }
170 break;
171 case DEV_PATH_BR_VLAN_KEEP:
172 break;
173 }
174 info->xmit_type = FLOW_OFFLOAD_XMIT_DIRECT;
175 break;
176 default:
177 info->indev = NULL;
178 break;
179 }
180 }
181 info->outdev = info->indev;
182
183 if (nf_flowtable_hw_offload(flowtable) &&
184 nft_is_valid_ether_device(info->indev))
185 info->xmit_type = FLOW_OFFLOAD_XMIT_DIRECT;
186 }
187
nft_flowtable_find_dev(const struct net_device * dev,struct nft_flowtable * ft)188 static bool nft_flowtable_find_dev(const struct net_device *dev,
189 struct nft_flowtable *ft)
190 {
191 struct nft_hook *hook;
192 bool found = false;
193
194 list_for_each_entry_rcu(hook, &ft->hook_list, list) {
195 if (!nft_hook_find_ops_rcu(hook, dev))
196 continue;
197
198 found = true;
199 break;
200 }
201
202 return found;
203 }
204
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)205 static int nft_flow_tunnel_update_route(const struct nft_pktinfo *pkt,
206 struct flow_offload_tunnel *tun,
207 struct nf_flow_route *route,
208 enum ip_conntrack_dir dir)
209 {
210 struct dst_entry *cur_dst = route->tuple[dir].dst;
211 struct dst_entry *tun_dst = NULL;
212 struct flowi fl = {};
213
214 switch (nft_pf(pkt)) {
215 case NFPROTO_IPV4:
216 fl.u.ip4.daddr = tun->dst_v4.s_addr;
217 fl.u.ip4.saddr = tun->src_v4.s_addr;
218 fl.u.ip4.flowi4_iif = nft_in(pkt)->ifindex;
219 fl.u.ip4.flowi4_dscp = ip4h_dscp(ip_hdr(pkt->skb));
220 fl.u.ip4.flowi4_mark = pkt->skb->mark;
221 fl.u.ip4.flowi4_flags = FLOWI_FLAG_ANYSRC;
222 break;
223 case NFPROTO_IPV6:
224 fl.u.ip6.daddr = tun->dst_v6;
225 fl.u.ip6.saddr = tun->src_v6;
226 fl.u.ip6.flowi6_iif = nft_in(pkt)->ifindex;
227 fl.u.ip6.flowlabel = ip6_flowinfo(ipv6_hdr(pkt->skb));
228 fl.u.ip6.flowi6_mark = pkt->skb->mark;
229 fl.u.ip6.flowi6_flags = FLOWI_FLAG_ANYSRC;
230 break;
231 }
232
233 nf_route(nft_net(pkt), &tun_dst, &fl, false, nft_pf(pkt));
234 if (!tun_dst)
235 return -ENOENT;
236
237 route->tuple[dir].dst = tun_dst;
238 dst_release(cur_dst);
239
240 return 0;
241 }
242
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)243 static void nft_dev_forward_path(const struct nft_pktinfo *pkt,
244 struct nf_flow_route *route,
245 const struct nf_conn *ct,
246 enum ip_conntrack_dir dir,
247 struct nft_flowtable *ft)
248 {
249 const struct dst_entry *dst = route->tuple[dir].dst;
250 struct net_device_path_stack stack;
251 struct nft_forward_info info = {};
252 unsigned char ha[ETH_ALEN];
253 int i;
254
255 if (nft_dev_fill_forward_path(route, dst, ct, dir, ha, &stack) >= 0)
256 nft_dev_path_info(&stack, &info, ha, &ft->data);
257
258 if (info.outdev)
259 route->tuple[dir].out.ifindex = info.outdev->ifindex;
260
261 if (!info.indev || !nft_flowtable_find_dev(info.indev, ft))
262 return;
263
264 route->tuple[!dir].in.ifindex = info.indev->ifindex;
265 for (i = 0; i < info.num_encaps; i++) {
266 route->tuple[!dir].in.encap[i].id = info.encap[i].id;
267 route->tuple[!dir].in.encap[i].proto = info.encap[i].proto;
268 }
269
270 if (info.num_tuns &&
271 !nft_flow_tunnel_update_route(pkt, &info.tun, route, dir)) {
272 route->tuple[!dir].in.tun.src_v6 = info.tun.dst_v6;
273 route->tuple[!dir].in.tun.dst_v6 = info.tun.src_v6;
274 route->tuple[!dir].in.tun.l3_proto = info.tun.l3_proto;
275 route->tuple[!dir].in.num_tuns = info.num_tuns;
276 }
277
278 route->tuple[!dir].in.num_encaps = info.num_encaps;
279 route->tuple[!dir].in.ingress_vlans = info.ingress_vlans;
280
281 if (info.xmit_type == FLOW_OFFLOAD_XMIT_DIRECT) {
282 memcpy(route->tuple[dir].out.h_source, info.h_source, ETH_ALEN);
283 memcpy(route->tuple[dir].out.h_dest, info.h_dest, ETH_ALEN);
284 route->tuple[dir].xmit_type = info.xmit_type;
285 }
286 route->tuple[dir].out.needs_gso_segment = info.needs_gso_segment;
287 }
288
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)289 int nft_flow_route(const struct nft_pktinfo *pkt, const struct nf_conn *ct,
290 struct nf_flow_route *route, enum ip_conntrack_dir dir,
291 struct nft_flowtable *ft)
292 {
293 struct dst_entry *this_dst = skb_dst(pkt->skb);
294 struct dst_entry *other_dst = NULL;
295 struct flowi fl;
296
297 memset(&fl, 0, sizeof(fl));
298 switch (nft_pf(pkt)) {
299 case NFPROTO_IPV4:
300 fl.u.ip4.daddr = ct->tuplehash[dir].tuple.src.u3.ip;
301 fl.u.ip4.saddr = ct->tuplehash[!dir].tuple.src.u3.ip;
302 fl.u.ip4.flowi4_oif = nft_in(pkt)->ifindex;
303 fl.u.ip4.flowi4_iif = this_dst->dev->ifindex;
304 fl.u.ip4.flowi4_dscp = ip4h_dscp(ip_hdr(pkt->skb));
305 fl.u.ip4.flowi4_mark = pkt->skb->mark;
306 fl.u.ip4.flowi4_flags = FLOWI_FLAG_ANYSRC;
307 break;
308 case NFPROTO_IPV6:
309 fl.u.ip6.daddr = ct->tuplehash[dir].tuple.src.u3.in6;
310 fl.u.ip6.saddr = ct->tuplehash[!dir].tuple.src.u3.in6;
311 fl.u.ip6.flowi6_oif = nft_in(pkt)->ifindex;
312 fl.u.ip6.flowi6_iif = this_dst->dev->ifindex;
313 fl.u.ip6.flowlabel = ip6_flowinfo(ipv6_hdr(pkt->skb));
314 fl.u.ip6.flowi6_mark = pkt->skb->mark;
315 fl.u.ip6.flowi6_flags = FLOWI_FLAG_ANYSRC;
316 break;
317 }
318
319 if (!dst_hold_safe(this_dst))
320 return -ENOENT;
321
322 nf_route(nft_net(pkt), &other_dst, &fl, false, nft_pf(pkt));
323 if (!other_dst) {
324 dst_release(this_dst);
325 return -ENOENT;
326 }
327
328 nft_default_forward_path(route, this_dst, dir);
329 nft_default_forward_path(route, other_dst, !dir);
330
331 if (route->tuple[dir].xmit_type == FLOW_OFFLOAD_XMIT_NEIGH)
332 nft_dev_forward_path(pkt, route, ct, dir, ft);
333 if (route->tuple[!dir].xmit_type == FLOW_OFFLOAD_XMIT_NEIGH)
334 nft_dev_forward_path(pkt, route, ct, !dir, ft);
335
336 return 0;
337 }
338 EXPORT_SYMBOL_GPL(nft_flow_route);
339