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 * 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 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 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 priv->dreg = nft_parse_register(tb[NFTA_META_DREG]); 91 return nft_validate_register_store(ctx, priv->dreg, NULL, 92 NFT_DATA_VALUE, len); 93 } 94 95 static struct nft_expr_type nft_meta_bridge_type; 96 static const struct nft_expr_ops nft_meta_bridge_get_ops = { 97 .type = &nft_meta_bridge_type, 98 .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)), 99 .eval = nft_meta_bridge_get_eval, 100 .init = nft_meta_bridge_get_init, 101 .dump = nft_meta_get_dump, 102 }; 103 104 static const struct nft_expr_ops nft_meta_bridge_set_ops = { 105 .type = &nft_meta_bridge_type, 106 .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)), 107 .eval = nft_meta_set_eval, 108 .init = nft_meta_set_init, 109 .destroy = nft_meta_set_destroy, 110 .dump = nft_meta_set_dump, 111 .validate = nft_meta_set_validate, 112 }; 113 114 static const struct nft_expr_ops * 115 nft_meta_bridge_select_ops(const struct nft_ctx *ctx, 116 const struct nlattr * const tb[]) 117 { 118 if (tb[NFTA_META_KEY] == NULL) 119 return ERR_PTR(-EINVAL); 120 121 if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG]) 122 return ERR_PTR(-EINVAL); 123 124 if (tb[NFTA_META_DREG]) 125 return &nft_meta_bridge_get_ops; 126 127 if (tb[NFTA_META_SREG]) 128 return &nft_meta_bridge_set_ops; 129 130 return ERR_PTR(-EINVAL); 131 } 132 133 static struct nft_expr_type nft_meta_bridge_type __read_mostly = { 134 .family = NFPROTO_BRIDGE, 135 .name = "meta", 136 .select_ops = nft_meta_bridge_select_ops, 137 .policy = nft_meta_policy, 138 .maxattr = NFTA_META_MAX, 139 .owner = THIS_MODULE, 140 }; 141 142 static int __init nft_meta_bridge_module_init(void) 143 { 144 return nft_register_expr(&nft_meta_bridge_type); 145 } 146 147 static void __exit nft_meta_bridge_module_exit(void) 148 { 149 nft_unregister_expr(&nft_meta_bridge_type); 150 } 151 152 module_init(nft_meta_bridge_module_init); 153 module_exit(nft_meta_bridge_module_exit); 154 155 MODULE_LICENSE("GPL"); 156 MODULE_AUTHOR("wenxu <wenxu@ucloud.cn>"); 157 MODULE_ALIAS_NFT_AF_EXPR(AF_BRIDGE, "meta"); 158 MODULE_DESCRIPTION("Support for bridge dedicated meta key"); 159