1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2009 Patrick McHardy <kaber@trash.net> 4 * 5 * Development of this code funded by Astaro AG (http://www.astaro.com/) 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/init.h> 10 #include <linux/list.h> 11 #include <linux/rbtree.h> 12 #include <linux/netlink.h> 13 #include <linux/netfilter.h> 14 #include <linux/netfilter/nf_tables.h> 15 #include <net/netfilter/nf_tables.h> 16 #include <net/netfilter/nf_tables_core.h> 17 18 struct nft_lookup { 19 struct nft_set *set; 20 u8 sreg; 21 u8 dreg; 22 bool dreg_set; 23 bool invert; 24 struct nft_set_binding binding; 25 }; 26 27 #ifdef CONFIG_RETPOLINE 28 bool nft_set_do_lookup(const struct net *net, const struct nft_set *set, 29 const u32 *key, const struct nft_set_ext **ext) 30 { 31 if (set->ops == &nft_set_hash_fast_type.ops) 32 return nft_hash_lookup_fast(net, set, key, ext); 33 if (set->ops == &nft_set_hash_type.ops) 34 return nft_hash_lookup(net, set, key, ext); 35 36 if (set->ops == &nft_set_rhash_type.ops) 37 return nft_rhash_lookup(net, set, key, ext); 38 39 if (set->ops == &nft_set_bitmap_type.ops) 40 return nft_bitmap_lookup(net, set, key, ext); 41 42 if (set->ops == &nft_set_pipapo_type.ops) 43 return nft_pipapo_lookup(net, set, key, ext); 44 #if defined(CONFIG_X86_64) && !defined(CONFIG_UML) 45 if (set->ops == &nft_set_pipapo_avx2_type.ops) 46 return nft_pipapo_avx2_lookup(net, set, key, ext); 47 #endif 48 49 if (set->ops == &nft_set_rbtree_type.ops) 50 return nft_rbtree_lookup(net, set, key, ext); 51 52 WARN_ON_ONCE(1); 53 return set->ops->lookup(net, set, key, ext); 54 } 55 EXPORT_SYMBOL_GPL(nft_set_do_lookup); 56 #endif 57 58 void nft_lookup_eval(const struct nft_expr *expr, 59 struct nft_regs *regs, 60 const struct nft_pktinfo *pkt) 61 { 62 const struct nft_lookup *priv = nft_expr_priv(expr); 63 const struct nft_set *set = priv->set; 64 const struct nft_set_ext *ext = NULL; 65 const struct net *net = nft_net(pkt); 66 bool found; 67 68 found = nft_set_do_lookup(net, set, ®s->data[priv->sreg], &ext) ^ 69 priv->invert; 70 if (!found) { 71 ext = nft_set_catchall_lookup(net, set); 72 if (!ext) { 73 regs->verdict.code = NFT_BREAK; 74 return; 75 } 76 } 77 78 if (ext) { 79 if (priv->dreg_set) 80 nft_data_copy(®s->data[priv->dreg], 81 nft_set_ext_data(ext), set->dlen); 82 83 nft_set_elem_update_expr(ext, regs, pkt); 84 } 85 } 86 87 static const struct nla_policy nft_lookup_policy[NFTA_LOOKUP_MAX + 1] = { 88 [NFTA_LOOKUP_SET] = { .type = NLA_STRING, 89 .len = NFT_SET_MAXNAMELEN - 1 }, 90 [NFTA_LOOKUP_SET_ID] = { .type = NLA_U32 }, 91 [NFTA_LOOKUP_SREG] = { .type = NLA_U32 }, 92 [NFTA_LOOKUP_DREG] = { .type = NLA_U32 }, 93 [NFTA_LOOKUP_FLAGS] = { .type = NLA_U32 }, 94 }; 95 96 static int nft_lookup_init(const struct nft_ctx *ctx, 97 const struct nft_expr *expr, 98 const struct nlattr * const tb[]) 99 { 100 struct nft_lookup *priv = nft_expr_priv(expr); 101 u8 genmask = nft_genmask_next(ctx->net); 102 struct nft_set *set; 103 u32 flags; 104 int err; 105 106 if (tb[NFTA_LOOKUP_SET] == NULL || 107 tb[NFTA_LOOKUP_SREG] == NULL) 108 return -EINVAL; 109 110 set = nft_set_lookup_global(ctx->net, ctx->table, tb[NFTA_LOOKUP_SET], 111 tb[NFTA_LOOKUP_SET_ID], genmask); 112 if (IS_ERR(set)) 113 return PTR_ERR(set); 114 115 err = nft_parse_register_load(tb[NFTA_LOOKUP_SREG], &priv->sreg, 116 set->klen); 117 if (err < 0) 118 return err; 119 120 if (tb[NFTA_LOOKUP_FLAGS]) { 121 flags = ntohl(nla_get_be32(tb[NFTA_LOOKUP_FLAGS])); 122 123 if (flags & ~NFT_LOOKUP_F_INV) 124 return -EINVAL; 125 126 if (flags & NFT_LOOKUP_F_INV) 127 priv->invert = true; 128 } 129 130 if (tb[NFTA_LOOKUP_DREG] != NULL) { 131 if (priv->invert) 132 return -EINVAL; 133 if (!(set->flags & NFT_SET_MAP)) 134 return -EINVAL; 135 136 err = nft_parse_register_store(ctx, tb[NFTA_LOOKUP_DREG], 137 &priv->dreg, NULL, set->dtype, 138 set->dlen); 139 if (err < 0) 140 return err; 141 priv->dreg_set = true; 142 } else if (set->flags & NFT_SET_MAP) { 143 /* Map given, but user asks for lookup only (i.e. to 144 * ignore value assoicated with key). 145 * 146 * This makes no sense for anonymous maps since they are 147 * scoped to the rule, but for named sets this can be useful. 148 */ 149 if (set->flags & NFT_SET_ANONYMOUS) 150 return -EINVAL; 151 } 152 153 priv->binding.flags = set->flags & NFT_SET_MAP; 154 155 err = nf_tables_bind_set(ctx, set, &priv->binding); 156 if (err < 0) 157 return err; 158 159 priv->set = set; 160 return 0; 161 } 162 163 static void nft_lookup_deactivate(const struct nft_ctx *ctx, 164 const struct nft_expr *expr, 165 enum nft_trans_phase phase) 166 { 167 struct nft_lookup *priv = nft_expr_priv(expr); 168 169 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase); 170 } 171 172 static void nft_lookup_activate(const struct nft_ctx *ctx, 173 const struct nft_expr *expr) 174 { 175 struct nft_lookup *priv = nft_expr_priv(expr); 176 177 nf_tables_activate_set(ctx, priv->set); 178 } 179 180 static void nft_lookup_destroy(const struct nft_ctx *ctx, 181 const struct nft_expr *expr) 182 { 183 struct nft_lookup *priv = nft_expr_priv(expr); 184 185 nf_tables_destroy_set(ctx, priv->set); 186 } 187 188 static int nft_lookup_dump(struct sk_buff *skb, 189 const struct nft_expr *expr, bool reset) 190 { 191 const struct nft_lookup *priv = nft_expr_priv(expr); 192 u32 flags = priv->invert ? NFT_LOOKUP_F_INV : 0; 193 194 if (nla_put_string(skb, NFTA_LOOKUP_SET, priv->set->name)) 195 goto nla_put_failure; 196 if (nft_dump_register(skb, NFTA_LOOKUP_SREG, priv->sreg)) 197 goto nla_put_failure; 198 if (priv->dreg_set) 199 if (nft_dump_register(skb, NFTA_LOOKUP_DREG, priv->dreg)) 200 goto nla_put_failure; 201 if (nla_put_be32(skb, NFTA_LOOKUP_FLAGS, htonl(flags))) 202 goto nla_put_failure; 203 return 0; 204 205 nla_put_failure: 206 return -1; 207 } 208 209 static int nft_lookup_validate(const struct nft_ctx *ctx, 210 const struct nft_expr *expr, 211 const struct nft_data **d) 212 { 213 const struct nft_lookup *priv = nft_expr_priv(expr); 214 struct nft_set_iter iter; 215 216 if (!(priv->set->flags & NFT_SET_MAP) || 217 priv->set->dtype != NFT_DATA_VERDICT) 218 return 0; 219 220 iter.genmask = nft_genmask_next(ctx->net); 221 iter.skip = 0; 222 iter.count = 0; 223 iter.err = 0; 224 iter.fn = nft_setelem_validate; 225 226 priv->set->ops->walk(ctx, priv->set, &iter); 227 if (!iter.err) 228 iter.err = nft_set_catchall_validate(ctx, priv->set); 229 230 if (iter.err < 0) 231 return iter.err; 232 233 return 0; 234 } 235 236 static bool nft_lookup_reduce(struct nft_regs_track *track, 237 const struct nft_expr *expr) 238 { 239 const struct nft_lookup *priv = nft_expr_priv(expr); 240 241 if (priv->set->flags & NFT_SET_MAP) 242 nft_reg_track_cancel(track, priv->dreg, priv->set->dlen); 243 244 return false; 245 } 246 247 static const struct nft_expr_ops nft_lookup_ops = { 248 .type = &nft_lookup_type, 249 .size = NFT_EXPR_SIZE(sizeof(struct nft_lookup)), 250 .eval = nft_lookup_eval, 251 .init = nft_lookup_init, 252 .activate = nft_lookup_activate, 253 .deactivate = nft_lookup_deactivate, 254 .destroy = nft_lookup_destroy, 255 .dump = nft_lookup_dump, 256 .validate = nft_lookup_validate, 257 .reduce = nft_lookup_reduce, 258 }; 259 260 struct nft_expr_type nft_lookup_type __read_mostly = { 261 .name = "lookup", 262 .ops = &nft_lookup_ops, 263 .policy = nft_lookup_policy, 264 .maxattr = NFTA_LOOKUP_MAX, 265 .owner = THIS_MODULE, 266 }; 267