1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/init.h>
4 #include <linux/module.h>
5 #include <linux/netlink.h>
6 #include <linux/netfilter.h>
7 #include <linux/netfilter/nf_tables.h>
8 #include <net/netfilter/nf_tables.h>
9 #include <net/netfilter/nft_meta.h>
10 #include <linux/if_bridge.h>
11 #include <uapi/linux/netfilter_bridge.h> /* NF_BR_PRE_ROUTING */
12
13 #include "../br_private.h"
14
15 static const struct net_device *
nft_meta_get_bridge(const struct net_device * dev)16 nft_meta_get_bridge(const struct net_device *dev)
17 {
18 if (dev && netif_is_bridge_port(dev))
19 return netdev_master_upper_dev_get_rcu((struct net_device *)dev);
20
21 return NULL;
22 }
23
nft_meta_bridge_get_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)24 static void nft_meta_bridge_get_eval(const struct nft_expr *expr,
25 struct nft_regs *regs,
26 const struct nft_pktinfo *pkt)
27 {
28 const struct nft_meta *priv = nft_expr_priv(expr);
29 const struct net_device *in = nft_in(pkt), *out = nft_out(pkt);
30 u32 *dest = ®s->data[priv->dreg];
31 const struct net_device *br_dev;
32
33 switch (priv->key) {
34 case NFT_META_BRI_IIFNAME:
35 br_dev = nft_meta_get_bridge(in);
36 break;
37 case NFT_META_BRI_OIFNAME:
38 br_dev = nft_meta_get_bridge(out);
39 break;
40 case NFT_META_BRI_IIFPVID: {
41 u16 p_pvid;
42
43 br_dev = nft_meta_get_bridge(in);
44 if (!br_dev || !br_vlan_enabled(br_dev))
45 goto err;
46
47 br_vlan_get_pvid_rcu(in, &p_pvid);
48 nft_reg_store16(dest, p_pvid);
49 return;
50 }
51 case NFT_META_BRI_IIFVPROTO: {
52 u16 p_proto;
53
54 br_dev = nft_meta_get_bridge(in);
55 if (!br_dev || !br_vlan_enabled(br_dev))
56 goto err;
57
58 br_vlan_get_proto(br_dev, &p_proto);
59 nft_reg_store_be16(dest, htons(p_proto));
60 return;
61 }
62 default:
63 return nft_meta_get_eval(expr, regs, pkt);
64 }
65
66 strncpy((char *)dest, br_dev ? br_dev->name : "", IFNAMSIZ);
67 return;
68 err:
69 regs->verdict.code = NFT_BREAK;
70 }
71
nft_meta_bridge_get_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])72 static int nft_meta_bridge_get_init(const struct nft_ctx *ctx,
73 const struct nft_expr *expr,
74 const struct nlattr * const tb[])
75 {
76 struct nft_meta *priv = nft_expr_priv(expr);
77 unsigned int len;
78
79 priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
80 switch (priv->key) {
81 case NFT_META_BRI_IIFNAME:
82 case NFT_META_BRI_OIFNAME:
83 len = IFNAMSIZ;
84 break;
85 case NFT_META_BRI_IIFPVID:
86 case NFT_META_BRI_IIFVPROTO:
87 len = sizeof(u16);
88 break;
89 default:
90 return nft_meta_get_init(ctx, expr, tb);
91 }
92
93 priv->len = len;
94 return nft_parse_register_store(ctx, tb[NFTA_META_DREG], &priv->dreg,
95 NULL, NFT_DATA_VALUE, len);
96 }
97
98 static struct nft_expr_type nft_meta_bridge_type;
99 static const struct nft_expr_ops nft_meta_bridge_get_ops = {
100 .type = &nft_meta_bridge_type,
101 .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
102 .eval = nft_meta_bridge_get_eval,
103 .init = nft_meta_bridge_get_init,
104 .dump = nft_meta_get_dump,
105 .reduce = nft_meta_get_reduce,
106 };
107
nft_meta_bridge_set_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)108 static void nft_meta_bridge_set_eval(const struct nft_expr *expr,
109 struct nft_regs *regs,
110 const struct nft_pktinfo *pkt)
111 {
112 const struct nft_meta *meta = nft_expr_priv(expr);
113 u32 *sreg = ®s->data[meta->sreg];
114 struct sk_buff *skb = pkt->skb;
115 u8 value8;
116
117 switch (meta->key) {
118 case NFT_META_BRI_BROUTE:
119 value8 = nft_reg_load8(sreg);
120 BR_INPUT_SKB_CB(skb)->br_netfilter_broute = !!value8;
121 break;
122 default:
123 nft_meta_set_eval(expr, regs, pkt);
124 }
125 }
126
nft_meta_bridge_set_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])127 static int nft_meta_bridge_set_init(const struct nft_ctx *ctx,
128 const struct nft_expr *expr,
129 const struct nlattr * const tb[])
130 {
131 struct nft_meta *priv = nft_expr_priv(expr);
132 unsigned int len;
133 int err;
134
135 priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
136 switch (priv->key) {
137 case NFT_META_BRI_BROUTE:
138 len = sizeof(u8);
139 break;
140 default:
141 return nft_meta_set_init(ctx, expr, tb);
142 }
143
144 priv->len = len;
145 err = nft_parse_register_load(tb[NFTA_META_SREG], &priv->sreg, len);
146 if (err < 0)
147 return err;
148
149 return 0;
150 }
151
nft_meta_bridge_set_reduce(struct nft_regs_track * track,const struct nft_expr * expr)152 static bool nft_meta_bridge_set_reduce(struct nft_regs_track *track,
153 const struct nft_expr *expr)
154 {
155 int i;
156
157 for (i = 0; i < NFT_REG32_NUM; i++) {
158 if (!track->regs[i].selector)
159 continue;
160
161 if (track->regs[i].selector->ops != &nft_meta_bridge_get_ops)
162 continue;
163
164 __nft_reg_track_cancel(track, i);
165 }
166
167 return false;
168 }
169
nft_meta_bridge_set_validate(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nft_data ** data)170 static int nft_meta_bridge_set_validate(const struct nft_ctx *ctx,
171 const struct nft_expr *expr,
172 const struct nft_data **data)
173 {
174 struct nft_meta *priv = nft_expr_priv(expr);
175 unsigned int hooks;
176
177 switch (priv->key) {
178 case NFT_META_BRI_BROUTE:
179 hooks = 1 << NF_BR_PRE_ROUTING;
180 break;
181 default:
182 return nft_meta_set_validate(ctx, expr, data);
183 }
184
185 return nft_chain_validate_hooks(ctx->chain, hooks);
186 }
187
188 static const struct nft_expr_ops nft_meta_bridge_set_ops = {
189 .type = &nft_meta_bridge_type,
190 .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
191 .eval = nft_meta_bridge_set_eval,
192 .init = nft_meta_bridge_set_init,
193 .destroy = nft_meta_set_destroy,
194 .dump = nft_meta_set_dump,
195 .reduce = nft_meta_bridge_set_reduce,
196 .validate = nft_meta_bridge_set_validate,
197 };
198
199 static const struct nft_expr_ops *
nft_meta_bridge_select_ops(const struct nft_ctx * ctx,const struct nlattr * const tb[])200 nft_meta_bridge_select_ops(const struct nft_ctx *ctx,
201 const struct nlattr * const tb[])
202 {
203 if (tb[NFTA_META_KEY] == NULL)
204 return ERR_PTR(-EINVAL);
205
206 if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG])
207 return ERR_PTR(-EINVAL);
208
209 if (tb[NFTA_META_DREG])
210 return &nft_meta_bridge_get_ops;
211
212 if (tb[NFTA_META_SREG])
213 return &nft_meta_bridge_set_ops;
214
215 return ERR_PTR(-EINVAL);
216 }
217
218 static struct nft_expr_type nft_meta_bridge_type __read_mostly = {
219 .family = NFPROTO_BRIDGE,
220 .name = "meta",
221 .select_ops = nft_meta_bridge_select_ops,
222 .policy = nft_meta_policy,
223 .maxattr = NFTA_META_MAX,
224 .owner = THIS_MODULE,
225 };
226
nft_meta_bridge_module_init(void)227 static int __init nft_meta_bridge_module_init(void)
228 {
229 return nft_register_expr(&nft_meta_bridge_type);
230 }
231
nft_meta_bridge_module_exit(void)232 static void __exit nft_meta_bridge_module_exit(void)
233 {
234 nft_unregister_expr(&nft_meta_bridge_type);
235 }
236
237 module_init(nft_meta_bridge_module_init);
238 module_exit(nft_meta_bridge_module_exit);
239
240 MODULE_LICENSE("GPL");
241 MODULE_AUTHOR("wenxu <wenxu@ucloud.cn>");
242 MODULE_ALIAS_NFT_AF_EXPR(AF_BRIDGE, "meta");
243 MODULE_DESCRIPTION("Support for bridge dedicated meta key");
244