1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * 4 * Generic part shared by ipv4 and ipv6 backends. 5 */ 6 7 #include <linux/kernel.h> 8 #include <linux/init.h> 9 #include <linux/module.h> 10 #include <linux/netlink.h> 11 #include <linux/netfilter.h> 12 #include <linux/netfilter/nf_tables.h> 13 #include <net/netfilter/nf_tables_core.h> 14 #include <net/netfilter/nf_tables.h> 15 #include <net/netfilter/nft_fib.h> 16 17 #define NFTA_FIB_F_ALL (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR | \ 18 NFTA_FIB_F_MARK | NFTA_FIB_F_IIF | NFTA_FIB_F_OIF | \ 19 NFTA_FIB_F_PRESENT) 20 21 const struct nla_policy nft_fib_policy[NFTA_FIB_MAX + 1] = { 22 [NFTA_FIB_DREG] = { .type = NLA_U32 }, 23 [NFTA_FIB_RESULT] = { .type = NLA_U32 }, 24 [NFTA_FIB_FLAGS] = 25 NLA_POLICY_MASK(NLA_BE32, NFTA_FIB_F_ALL), 26 }; 27 EXPORT_SYMBOL(nft_fib_policy); 28 29 int nft_fib_validate(const struct nft_ctx *ctx, const struct nft_expr *expr) 30 { 31 const struct nft_fib *priv = nft_expr_priv(expr); 32 unsigned int hooks; 33 34 switch (priv->result) { 35 case NFT_FIB_RESULT_OIF: 36 case NFT_FIB_RESULT_OIFNAME: 37 hooks = (1 << NF_INET_PRE_ROUTING) | 38 (1 << NF_INET_LOCAL_IN) | 39 (1 << NF_INET_FORWARD); 40 break; 41 case NFT_FIB_RESULT_ADDRTYPE: 42 if (priv->flags & NFTA_FIB_F_IIF) 43 hooks = (1 << NF_INET_PRE_ROUTING) | 44 (1 << NF_INET_LOCAL_IN) | 45 (1 << NF_INET_FORWARD); 46 else if (priv->flags & NFTA_FIB_F_OIF) 47 hooks = (1 << NF_INET_LOCAL_OUT) | 48 (1 << NF_INET_POST_ROUTING) | 49 (1 << NF_INET_FORWARD); 50 else 51 hooks = (1 << NF_INET_LOCAL_IN) | 52 (1 << NF_INET_LOCAL_OUT) | 53 (1 << NF_INET_FORWARD) | 54 (1 << NF_INET_PRE_ROUTING) | 55 (1 << NF_INET_POST_ROUTING); 56 57 break; 58 default: 59 return -EINVAL; 60 } 61 62 return nft_chain_validate_hooks(ctx->chain, hooks); 63 } 64 EXPORT_SYMBOL_GPL(nft_fib_validate); 65 66 int nft_fib_init(const struct nft_ctx *ctx, const struct nft_expr *expr, 67 const struct nlattr * const tb[]) 68 { 69 struct nft_fib *priv = nft_expr_priv(expr); 70 unsigned int len; 71 int err; 72 73 if (!tb[NFTA_FIB_DREG] || !tb[NFTA_FIB_RESULT] || !tb[NFTA_FIB_FLAGS]) 74 return -EINVAL; 75 76 priv->flags = ntohl(nla_get_be32(tb[NFTA_FIB_FLAGS])); 77 78 if (priv->flags == 0) 79 return -EINVAL; 80 81 if ((priv->flags & (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) == 82 (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) 83 return -EINVAL; 84 if ((priv->flags & (NFTA_FIB_F_IIF | NFTA_FIB_F_OIF)) == 85 (NFTA_FIB_F_IIF | NFTA_FIB_F_OIF)) 86 return -EINVAL; 87 if ((priv->flags & (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) == 0) 88 return -EINVAL; 89 90 priv->result = ntohl(nla_get_be32(tb[NFTA_FIB_RESULT])); 91 92 switch (priv->result) { 93 case NFT_FIB_RESULT_OIF: 94 if (priv->flags & NFTA_FIB_F_OIF) 95 return -EINVAL; 96 len = sizeof(int); 97 break; 98 case NFT_FIB_RESULT_OIFNAME: 99 if (priv->flags & NFTA_FIB_F_OIF) 100 return -EINVAL; 101 len = IFNAMSIZ; 102 break; 103 case NFT_FIB_RESULT_ADDRTYPE: 104 len = sizeof(u32); 105 break; 106 default: 107 return -EINVAL; 108 } 109 110 err = nft_parse_register_store(ctx, tb[NFTA_FIB_DREG], &priv->dreg, 111 NULL, NFT_DATA_VALUE, len); 112 if (err < 0) 113 return err; 114 115 return 0; 116 } 117 EXPORT_SYMBOL_GPL(nft_fib_init); 118 119 int nft_fib_dump(struct sk_buff *skb, const struct nft_expr *expr, bool reset) 120 { 121 const struct nft_fib *priv = nft_expr_priv(expr); 122 123 if (nft_dump_register(skb, NFTA_FIB_DREG, priv->dreg)) 124 return -1; 125 126 if (nla_put_be32(skb, NFTA_FIB_RESULT, htonl(priv->result))) 127 return -1; 128 129 if (nla_put_be32(skb, NFTA_FIB_FLAGS, htonl(priv->flags))) 130 return -1; 131 132 return 0; 133 } 134 EXPORT_SYMBOL_GPL(nft_fib_dump); 135 136 void nft_fib_store_result(void *reg, const struct nft_fib *priv, 137 const struct net_device *dev) 138 { 139 u32 *dreg = reg; 140 int index; 141 142 switch (priv->result) { 143 case NFT_FIB_RESULT_OIF: 144 index = dev ? dev->ifindex : 0; 145 if (priv->flags & NFTA_FIB_F_PRESENT) 146 nft_reg_store8(dreg, !!index); 147 else 148 *dreg = index; 149 150 break; 151 case NFT_FIB_RESULT_OIFNAME: 152 if (priv->flags & NFTA_FIB_F_PRESENT) 153 nft_reg_store8(dreg, !!dev); 154 else 155 strscpy_pad(reg, dev ? dev->name : "", IFNAMSIZ); 156 break; 157 default: 158 WARN_ON_ONCE(1); 159 *dreg = 0; 160 break; 161 } 162 } 163 EXPORT_SYMBOL_GPL(nft_fib_store_result); 164 165 bool nft_fib_reduce(struct nft_regs_track *track, 166 const struct nft_expr *expr) 167 { 168 const struct nft_fib *priv = nft_expr_priv(expr); 169 unsigned int len = NFT_REG32_SIZE; 170 const struct nft_fib *fib; 171 172 switch (priv->result) { 173 case NFT_FIB_RESULT_OIF: 174 break; 175 case NFT_FIB_RESULT_OIFNAME: 176 if (priv->flags & NFTA_FIB_F_PRESENT) 177 len = NFT_REG32_SIZE; 178 else 179 len = IFNAMSIZ; 180 break; 181 case NFT_FIB_RESULT_ADDRTYPE: 182 break; 183 default: 184 WARN_ON_ONCE(1); 185 break; 186 } 187 188 if (!nft_reg_track_cmp(track, expr, priv->dreg)) { 189 nft_reg_track_update(track, expr, priv->dreg, len); 190 return false; 191 } 192 193 fib = nft_expr_priv(track->regs[priv->dreg].selector); 194 if (priv->result != fib->result || 195 priv->flags != fib->flags) { 196 nft_reg_track_update(track, expr, priv->dreg, len); 197 return false; 198 } 199 200 if (!track->regs[priv->dreg].bitwise) 201 return true; 202 203 return false; 204 } 205 EXPORT_SYMBOL_GPL(nft_fib_reduce); 206 207 MODULE_LICENSE("GPL"); 208 MODULE_DESCRIPTION("Query routing table from nftables"); 209 MODULE_AUTHOR("Florian Westphal <fw@strlen.de>"); 210