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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
39e6dea2 PNA |
2 | /* |
3 | * Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org> | |
39e6dea2 PNA |
4 | */ |
5 | ||
6 | #include <linux/kernel.h> | |
7 | #include <linux/init.h> | |
8 | #include <linux/module.h> | |
9 | #include <linux/netlink.h> | |
10 | #include <linux/netfilter.h> | |
11 | #include <linux/netfilter/nf_tables.h> | |
d32de98e PNA |
12 | #include <linux/ip.h> |
13 | #include <linux/ipv6.h> | |
39e6dea2 | 14 | #include <net/netfilter/nf_tables.h> |
be2861dc | 15 | #include <net/netfilter/nf_tables_offload.h> |
39e6dea2 | 16 | #include <net/netfilter/nf_dup_netdev.h> |
d32de98e PNA |
17 | #include <net/neighbour.h> |
18 | #include <net/ip.h> | |
39e6dea2 PNA |
19 | |
20 | struct nft_fwd_netdev { | |
4f16d25c | 21 | u8 sreg_dev; |
39e6dea2 PNA |
22 | }; |
23 | ||
24 | static void nft_fwd_netdev_eval(const struct nft_expr *expr, | |
25 | struct nft_regs *regs, | |
26 | const struct nft_pktinfo *pkt) | |
27 | { | |
28 | struct nft_fwd_netdev *priv = nft_expr_priv(expr); | |
29 | int oif = regs->data[priv->sreg_dev]; | |
f87b9464 | 30 | struct sk_buff *skb = pkt->skb; |
39e6dea2 | 31 | |
2c64605b | 32 | /* This is used by ifb only. */ |
f87b9464 PNA |
33 | skb->skb_iif = skb->dev->ifindex; |
34 | skb_set_redirected(skb, nft_hook(pkt) == NF_NETDEV_INGRESS); | |
bcfabee1 | 35 | |
3bf32761 FW |
36 | nf_fwd_netdev_egress(pkt, oif); |
37 | regs->verdict.code = NF_STOLEN; | |
39e6dea2 PNA |
38 | } |
39 | ||
40 | static const struct nla_policy nft_fwd_netdev_policy[NFTA_FWD_MAX + 1] = { | |
41 | [NFTA_FWD_SREG_DEV] = { .type = NLA_U32 }, | |
d32de98e PNA |
42 | [NFTA_FWD_SREG_ADDR] = { .type = NLA_U32 }, |
43 | [NFTA_FWD_NFPROTO] = { .type = NLA_U32 }, | |
39e6dea2 PNA |
44 | }; |
45 | ||
46 | static int nft_fwd_netdev_init(const struct nft_ctx *ctx, | |
47 | const struct nft_expr *expr, | |
48 | const struct nlattr * const tb[]) | |
49 | { | |
50 | struct nft_fwd_netdev *priv = nft_expr_priv(expr); | |
51 | ||
52 | if (tb[NFTA_FWD_SREG_DEV] == NULL) | |
53 | return -EINVAL; | |
54 | ||
4f16d25c PNA |
55 | return nft_parse_register_load(tb[NFTA_FWD_SREG_DEV], &priv->sreg_dev, |
56 | sizeof(int)); | |
39e6dea2 PNA |
57 | } |
58 | ||
7d34aa3e PS |
59 | static int nft_fwd_netdev_dump(struct sk_buff *skb, |
60 | const struct nft_expr *expr, bool reset) | |
39e6dea2 PNA |
61 | { |
62 | struct nft_fwd_netdev *priv = nft_expr_priv(expr); | |
63 | ||
64 | if (nft_dump_register(skb, NFTA_FWD_SREG_DEV, priv->sreg_dev)) | |
65 | goto nla_put_failure; | |
66 | ||
67 | return 0; | |
68 | ||
69 | nla_put_failure: | |
70 | return -1; | |
71 | } | |
72 | ||
be2861dc PNA |
73 | static int nft_fwd_netdev_offload(struct nft_offload_ctx *ctx, |
74 | struct nft_flow_rule *flow, | |
75 | const struct nft_expr *expr) | |
76 | { | |
77 | const struct nft_fwd_netdev *priv = nft_expr_priv(expr); | |
78 | int oif = ctx->regs[priv->sreg_dev].data.data[0]; | |
79 | ||
80 | return nft_fwd_dup_netdev_offload(ctx, flow, FLOW_ACTION_REDIRECT, oif); | |
81 | } | |
82 | ||
b1a5983f PNA |
83 | static bool nft_fwd_netdev_offload_action(const struct nft_expr *expr) |
84 | { | |
85 | return true; | |
86 | } | |
87 | ||
d32de98e | 88 | struct nft_fwd_neigh { |
4f16d25c PNA |
89 | u8 sreg_dev; |
90 | u8 sreg_addr; | |
d32de98e PNA |
91 | u8 nfproto; |
92 | }; | |
93 | ||
94 | static void nft_fwd_neigh_eval(const struct nft_expr *expr, | |
95 | struct nft_regs *regs, | |
96 | const struct nft_pktinfo *pkt) | |
97 | { | |
98 | struct nft_fwd_neigh *priv = nft_expr_priv(expr); | |
99 | void *addr = ®s->data[priv->sreg_addr]; | |
100 | int oif = regs->data[priv->sreg_dev]; | |
101 | unsigned int verdict = NF_STOLEN; | |
102 | struct sk_buff *skb = pkt->skb; | |
103 | struct net_device *dev; | |
104 | int neigh_table; | |
105 | ||
106 | switch (priv->nfproto) { | |
107 | case NFPROTO_IPV4: { | |
108 | struct iphdr *iph; | |
109 | ||
110 | if (skb->protocol != htons(ETH_P_IP)) { | |
111 | verdict = NFT_BREAK; | |
112 | goto out; | |
113 | } | |
114 | if (skb_try_make_writable(skb, sizeof(*iph))) { | |
115 | verdict = NF_DROP; | |
116 | goto out; | |
117 | } | |
118 | iph = ip_hdr(skb); | |
119 | ip_decrease_ttl(iph); | |
120 | neigh_table = NEIGH_ARP_TABLE; | |
121 | break; | |
122 | } | |
123 | case NFPROTO_IPV6: { | |
124 | struct ipv6hdr *ip6h; | |
125 | ||
126 | if (skb->protocol != htons(ETH_P_IPV6)) { | |
127 | verdict = NFT_BREAK; | |
128 | goto out; | |
129 | } | |
130 | if (skb_try_make_writable(skb, sizeof(*ip6h))) { | |
131 | verdict = NF_DROP; | |
132 | goto out; | |
133 | } | |
134 | ip6h = ipv6_hdr(skb); | |
135 | ip6h->hop_limit--; | |
136 | neigh_table = NEIGH_ND_TABLE; | |
137 | break; | |
138 | } | |
139 | default: | |
140 | verdict = NFT_BREAK; | |
141 | goto out; | |
142 | } | |
143 | ||
144 | dev = dev_get_by_index_rcu(nft_net(pkt), oif); | |
145 | if (dev == NULL) | |
146 | return; | |
147 | ||
148 | skb->dev = dev; | |
de799101 | 149 | skb_clear_tstamp(skb); |
d32de98e PNA |
150 | neigh_xmit(neigh_table, dev, addr, skb); |
151 | out: | |
152 | regs->verdict.code = verdict; | |
153 | } | |
154 | ||
155 | static int nft_fwd_neigh_init(const struct nft_ctx *ctx, | |
156 | const struct nft_expr *expr, | |
157 | const struct nlattr * const tb[]) | |
158 | { | |
159 | struct nft_fwd_neigh *priv = nft_expr_priv(expr); | |
160 | unsigned int addr_len; | |
161 | int err; | |
162 | ||
163 | if (!tb[NFTA_FWD_SREG_DEV] || | |
164 | !tb[NFTA_FWD_SREG_ADDR] || | |
165 | !tb[NFTA_FWD_NFPROTO]) | |
166 | return -EINVAL; | |
167 | ||
d32de98e PNA |
168 | priv->nfproto = ntohl(nla_get_be32(tb[NFTA_FWD_NFPROTO])); |
169 | ||
170 | switch (priv->nfproto) { | |
171 | case NFPROTO_IPV4: | |
172 | addr_len = sizeof(struct in_addr); | |
173 | break; | |
174 | case NFPROTO_IPV6: | |
175 | addr_len = sizeof(struct in6_addr); | |
176 | break; | |
177 | default: | |
178 | return -EOPNOTSUPP; | |
179 | } | |
180 | ||
4f16d25c PNA |
181 | err = nft_parse_register_load(tb[NFTA_FWD_SREG_DEV], &priv->sreg_dev, |
182 | sizeof(int)); | |
d32de98e PNA |
183 | if (err < 0) |
184 | return err; | |
185 | ||
4f16d25c PNA |
186 | return nft_parse_register_load(tb[NFTA_FWD_SREG_ADDR], &priv->sreg_addr, |
187 | addr_len); | |
d32de98e PNA |
188 | } |
189 | ||
7d34aa3e PS |
190 | static int nft_fwd_neigh_dump(struct sk_buff *skb, |
191 | const struct nft_expr *expr, bool reset) | |
d32de98e PNA |
192 | { |
193 | struct nft_fwd_neigh *priv = nft_expr_priv(expr); | |
194 | ||
195 | if (nft_dump_register(skb, NFTA_FWD_SREG_DEV, priv->sreg_dev) || | |
196 | nft_dump_register(skb, NFTA_FWD_SREG_ADDR, priv->sreg_addr) || | |
197 | nla_put_be32(skb, NFTA_FWD_NFPROTO, htonl(priv->nfproto))) | |
198 | goto nla_put_failure; | |
199 | ||
200 | return 0; | |
201 | ||
202 | nla_put_failure: | |
203 | return -1; | |
204 | } | |
205 | ||
76a109fa PNA |
206 | static int nft_fwd_validate(const struct nft_ctx *ctx, |
207 | const struct nft_expr *expr, | |
208 | const struct nft_data **data) | |
209 | { | |
f87b9464 PNA |
210 | return nft_chain_validate_hooks(ctx->chain, (1 << NF_NETDEV_INGRESS) | |
211 | (1 << NF_NETDEV_EGRESS)); | |
76a109fa PNA |
212 | } |
213 | ||
39e6dea2 | 214 | static struct nft_expr_type nft_fwd_netdev_type; |
d32de98e PNA |
215 | static const struct nft_expr_ops nft_fwd_neigh_netdev_ops = { |
216 | .type = &nft_fwd_netdev_type, | |
217 | .size = NFT_EXPR_SIZE(sizeof(struct nft_fwd_neigh)), | |
218 | .eval = nft_fwd_neigh_eval, | |
219 | .init = nft_fwd_neigh_init, | |
220 | .dump = nft_fwd_neigh_dump, | |
76a109fa | 221 | .validate = nft_fwd_validate, |
b2d30654 | 222 | .reduce = NFT_REDUCE_READONLY, |
d32de98e PNA |
223 | }; |
224 | ||
39e6dea2 PNA |
225 | static const struct nft_expr_ops nft_fwd_netdev_ops = { |
226 | .type = &nft_fwd_netdev_type, | |
227 | .size = NFT_EXPR_SIZE(sizeof(struct nft_fwd_netdev)), | |
228 | .eval = nft_fwd_netdev_eval, | |
229 | .init = nft_fwd_netdev_init, | |
230 | .dump = nft_fwd_netdev_dump, | |
76a109fa | 231 | .validate = nft_fwd_validate, |
b2d30654 | 232 | .reduce = NFT_REDUCE_READONLY, |
be2861dc | 233 | .offload = nft_fwd_netdev_offload, |
b1a5983f | 234 | .offload_action = nft_fwd_netdev_offload_action, |
39e6dea2 PNA |
235 | }; |
236 | ||
d32de98e PNA |
237 | static const struct nft_expr_ops * |
238 | nft_fwd_select_ops(const struct nft_ctx *ctx, | |
239 | const struct nlattr * const tb[]) | |
240 | { | |
241 | if (tb[NFTA_FWD_SREG_ADDR]) | |
242 | return &nft_fwd_neigh_netdev_ops; | |
243 | if (tb[NFTA_FWD_SREG_DEV]) | |
244 | return &nft_fwd_netdev_ops; | |
245 | ||
246 | return ERR_PTR(-EOPNOTSUPP); | |
247 | } | |
248 | ||
39e6dea2 PNA |
249 | static struct nft_expr_type nft_fwd_netdev_type __read_mostly = { |
250 | .family = NFPROTO_NETDEV, | |
251 | .name = "fwd", | |
d32de98e | 252 | .select_ops = nft_fwd_select_ops, |
39e6dea2 PNA |
253 | .policy = nft_fwd_netdev_policy, |
254 | .maxattr = NFTA_FWD_MAX, | |
255 | .owner = THIS_MODULE, | |
256 | }; | |
257 | ||
258 | static int __init nft_fwd_netdev_module_init(void) | |
259 | { | |
260 | return nft_register_expr(&nft_fwd_netdev_type); | |
261 | } | |
262 | ||
263 | static void __exit nft_fwd_netdev_module_exit(void) | |
264 | { | |
265 | nft_unregister_expr(&nft_fwd_netdev_type); | |
266 | } | |
267 | ||
268 | module_init(nft_fwd_netdev_module_init); | |
269 | module_exit(nft_fwd_netdev_module_exit); | |
270 | ||
271 | MODULE_LICENSE("GPL"); | |
272 | MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); | |
273 | MODULE_ALIAS_NFT_AF_EXPR(5, "fwd"); |