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
12 static const struct net_device *
nft_meta_get_bridge(const struct net_device * dev)13 nft_meta_get_bridge(const struct net_device *dev)
14 {
15 if (dev && netif_is_bridge_port(dev))
16 return netdev_master_upper_dev_get_rcu((struct net_device *)dev);
17
18 return NULL;
19 }
20
nft_meta_bridge_get_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)21 static void nft_meta_bridge_get_eval(const struct nft_expr *expr,
22 struct nft_regs *regs,
23 const struct nft_pktinfo *pkt)
24 {
25 const struct nft_meta *priv = nft_expr_priv(expr);
26 const struct net_device *in = nft_in(pkt), *out = nft_out(pkt);
27 u32 *dest = ®s->data[priv->dreg];
28 const struct net_device *br_dev;
29
30 switch (priv->key) {
31 case NFT_META_BRI_IIFNAME:
32 br_dev = nft_meta_get_bridge(in);
33 break;
34 case NFT_META_BRI_OIFNAME:
35 br_dev = nft_meta_get_bridge(out);
36 break;
37 case NFT_META_BRI_IIFPVID: {
38 u16 p_pvid;
39
40 br_dev = nft_meta_get_bridge(in);
41 if (!br_dev || !br_vlan_enabled(br_dev))
42 goto err;
43
44 br_vlan_get_pvid_rcu(in, &p_pvid);
45 nft_reg_store16(dest, p_pvid);
46 return;
47 }
48 case NFT_META_BRI_IIFVPROTO: {
49 u16 p_proto;
50
51 br_dev = nft_meta_get_bridge(in);
52 if (!br_dev || !br_vlan_enabled(br_dev))
53 goto err;
54
55 br_vlan_get_proto(br_dev, &p_proto);
56 nft_reg_store16(dest, htons(p_proto));
57 return;
58 }
59 default:
60 return nft_meta_get_eval(expr, regs, pkt);
61 }
62
63 strncpy((char *)dest, br_dev ? br_dev->name : "", IFNAMSIZ);
64 return;
65 err:
66 regs->verdict.code = NFT_BREAK;
67 }
68
nft_meta_bridge_get_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])69 static int nft_meta_bridge_get_init(const struct nft_ctx *ctx,
70 const struct nft_expr *expr,
71 const struct nlattr * const tb[])
72 {
73 struct nft_meta *priv = nft_expr_priv(expr);
74 unsigned int len;
75
76 priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
77 switch (priv->key) {
78 case NFT_META_BRI_IIFNAME:
79 case NFT_META_BRI_OIFNAME:
80 len = IFNAMSIZ;
81 break;
82 case NFT_META_BRI_IIFPVID:
83 case NFT_META_BRI_IIFVPROTO:
84 len = sizeof(u16);
85 break;
86 default:
87 return nft_meta_get_init(ctx, expr, tb);
88 }
89
90 return nft_parse_register_store(ctx, tb[NFTA_META_DREG], &priv->dreg,
91 NULL, NFT_DATA_VALUE, len);
92 }
93
94 static struct nft_expr_type nft_meta_bridge_type;
95 static const struct nft_expr_ops nft_meta_bridge_get_ops = {
96 .type = &nft_meta_bridge_type,
97 .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
98 .eval = nft_meta_bridge_get_eval,
99 .init = nft_meta_bridge_get_init,
100 .dump = nft_meta_get_dump,
101 };
102
103 static const struct nft_expr_ops nft_meta_bridge_set_ops = {
104 .type = &nft_meta_bridge_type,
105 .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
106 .eval = nft_meta_set_eval,
107 .init = nft_meta_set_init,
108 .destroy = nft_meta_set_destroy,
109 .dump = nft_meta_set_dump,
110 .validate = nft_meta_set_validate,
111 };
112
113 static const struct nft_expr_ops *
nft_meta_bridge_select_ops(const struct nft_ctx * ctx,const struct nlattr * const tb[])114 nft_meta_bridge_select_ops(const struct nft_ctx *ctx,
115 const struct nlattr * const tb[])
116 {
117 if (tb[NFTA_META_KEY] == NULL)
118 return ERR_PTR(-EINVAL);
119
120 if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG])
121 return ERR_PTR(-EINVAL);
122
123 if (tb[NFTA_META_DREG])
124 return &nft_meta_bridge_get_ops;
125
126 if (tb[NFTA_META_SREG])
127 return &nft_meta_bridge_set_ops;
128
129 return ERR_PTR(-EINVAL);
130 }
131
132 static struct nft_expr_type nft_meta_bridge_type __read_mostly = {
133 .family = NFPROTO_BRIDGE,
134 .name = "meta",
135 .select_ops = nft_meta_bridge_select_ops,
136 .policy = nft_meta_policy,
137 .maxattr = NFTA_META_MAX,
138 .owner = THIS_MODULE,
139 };
140
nft_meta_bridge_module_init(void)141 static int __init nft_meta_bridge_module_init(void)
142 {
143 return nft_register_expr(&nft_meta_bridge_type);
144 }
145
nft_meta_bridge_module_exit(void)146 static void __exit nft_meta_bridge_module_exit(void)
147 {
148 nft_unregister_expr(&nft_meta_bridge_type);
149 }
150
151 module_init(nft_meta_bridge_module_init);
152 module_exit(nft_meta_bridge_module_exit);
153
154 MODULE_LICENSE("GPL");
155 MODULE_AUTHOR("wenxu <wenxu@ucloud.cn>");
156 MODULE_ALIAS_NFT_AF_EXPR(AF_BRIDGE, "meta");
157 MODULE_DESCRIPTION("Support for bridge dedicated meta key");
158