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 * 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 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 strscpy_pad((char *)dest, br_dev ? br_dev->name : "", IFNAMSIZ); 67 return; 68 err: 69 regs->verdict.code = NFT_BREAK; 70 } 71 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 }; 107 108 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 } 126 127 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(ctx, tb[NFTA_META_SREG], &priv->sreg, len); 146 if (err < 0) 147 return err; 148 149 return 0; 150 } 151 152 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 } 169 170 static int nft_meta_bridge_set_validate(const struct nft_ctx *ctx, 171 const struct nft_expr *expr) 172 { 173 struct nft_meta *priv = nft_expr_priv(expr); 174 unsigned int hooks; 175 176 switch (priv->key) { 177 case NFT_META_BRI_BROUTE: 178 hooks = 1 << NF_BR_PRE_ROUTING; 179 break; 180 default: 181 return nft_meta_set_validate(ctx, expr); 182 } 183 184 return nft_chain_validate_hooks(ctx->chain, hooks); 185 } 186 187 static const struct nft_expr_ops nft_meta_bridge_set_ops = { 188 .type = &nft_meta_bridge_type, 189 .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)), 190 .eval = nft_meta_bridge_set_eval, 191 .init = nft_meta_bridge_set_init, 192 .destroy = nft_meta_set_destroy, 193 .dump = nft_meta_set_dump, 194 .reduce = nft_meta_bridge_set_reduce, 195 .validate = nft_meta_bridge_set_validate, 196 }; 197 198 static const struct nft_expr_ops * 199 nft_meta_bridge_select_ops(const struct nft_ctx *ctx, 200 const struct nlattr * const tb[]) 201 { 202 if (tb[NFTA_META_KEY] == NULL) 203 return ERR_PTR(-EINVAL); 204 205 if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG]) 206 return ERR_PTR(-EINVAL); 207 208 if (tb[NFTA_META_DREG]) 209 return &nft_meta_bridge_get_ops; 210 211 if (tb[NFTA_META_SREG]) 212 return &nft_meta_bridge_set_ops; 213 214 return ERR_PTR(-EINVAL); 215 } 216 217 static struct nft_expr_type nft_meta_bridge_type __read_mostly = { 218 .family = NFPROTO_BRIDGE, 219 .name = "meta", 220 .select_ops = nft_meta_bridge_select_ops, 221 .policy = nft_meta_policy, 222 .maxattr = NFTA_META_MAX, 223 .owner = THIS_MODULE, 224 }; 225 226 static int __init nft_meta_bridge_module_init(void) 227 { 228 return nft_register_expr(&nft_meta_bridge_type); 229 } 230 231 static void __exit nft_meta_bridge_module_exit(void) 232 { 233 nft_unregister_expr(&nft_meta_bridge_type); 234 } 235 236 module_init(nft_meta_bridge_module_init); 237 module_exit(nft_meta_bridge_module_exit); 238 239 MODULE_LICENSE("GPL"); 240 MODULE_AUTHOR("wenxu <wenxu@ucloud.cn>"); 241 MODULE_ALIAS_NFT_AF_EXPR(AF_BRIDGE, "meta"); 242 MODULE_DESCRIPTION("Support for bridge dedicated meta key"); 243