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] = 94 NLA_POLICY_MASK(NLA_BE32, NFT_LOOKUP_F_INV), 95 }; 96 97 static int nft_lookup_init(const struct nft_ctx *ctx, 98 const struct nft_expr *expr, 99 const struct nlattr * const tb[]) 100 { 101 struct nft_lookup *priv = nft_expr_priv(expr); 102 u8 genmask = nft_genmask_next(ctx->net); 103 struct nft_set *set; 104 u32 flags; 105 int err; 106 107 if (tb[NFTA_LOOKUP_SET] == NULL || 108 tb[NFTA_LOOKUP_SREG] == NULL) 109 return -EINVAL; 110 111 set = nft_set_lookup_global(ctx->net, ctx->table, tb[NFTA_LOOKUP_SET], 112 tb[NFTA_LOOKUP_SET_ID], genmask); 113 if (IS_ERR(set)) 114 return PTR_ERR(set); 115 116 err = nft_parse_register_load(tb[NFTA_LOOKUP_SREG], &priv->sreg, 117 set->klen); 118 if (err < 0) 119 return err; 120 121 if (tb[NFTA_LOOKUP_FLAGS]) { 122 flags = ntohl(nla_get_be32(tb[NFTA_LOOKUP_FLAGS])); 123 124 if (flags & NFT_LOOKUP_F_INV) 125 priv->invert = true; 126 } 127 128 if (tb[NFTA_LOOKUP_DREG] != NULL) { 129 if (priv->invert) 130 return -EINVAL; 131 if (!(set->flags & NFT_SET_MAP)) 132 return -EINVAL; 133 134 err = nft_parse_register_store(ctx, tb[NFTA_LOOKUP_DREG], 135 &priv->dreg, NULL, set->dtype, 136 set->dlen); 137 if (err < 0) 138 return err; 139 priv->dreg_set = true; 140 } else if (set->flags & NFT_SET_MAP) { 141 /* Map given, but user asks for lookup only (i.e. to 142 * ignore value assoicated with key). 143 * 144 * This makes no sense for anonymous maps since they are 145 * scoped to the rule, but for named sets this can be useful. 146 */ 147 if (set->flags & NFT_SET_ANONYMOUS) 148 return -EINVAL; 149 } 150 151 priv->binding.flags = set->flags & NFT_SET_MAP; 152 153 err = nf_tables_bind_set(ctx, set, &priv->binding); 154 if (err < 0) 155 return err; 156 157 priv->set = set; 158 return 0; 159 } 160 161 static void nft_lookup_deactivate(const struct nft_ctx *ctx, 162 const struct nft_expr *expr, 163 enum nft_trans_phase phase) 164 { 165 struct nft_lookup *priv = nft_expr_priv(expr); 166 167 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase); 168 } 169 170 static void nft_lookup_activate(const struct nft_ctx *ctx, 171 const struct nft_expr *expr) 172 { 173 struct nft_lookup *priv = nft_expr_priv(expr); 174 175 nf_tables_activate_set(ctx, priv->set); 176 } 177 178 static void nft_lookup_destroy(const struct nft_ctx *ctx, 179 const struct nft_expr *expr) 180 { 181 struct nft_lookup *priv = nft_expr_priv(expr); 182 183 nf_tables_destroy_set(ctx, priv->set); 184 } 185 186 static int nft_lookup_dump(struct sk_buff *skb, 187 const struct nft_expr *expr, bool reset) 188 { 189 const struct nft_lookup *priv = nft_expr_priv(expr); 190 u32 flags = priv->invert ? NFT_LOOKUP_F_INV : 0; 191 192 if (nla_put_string(skb, NFTA_LOOKUP_SET, priv->set->name)) 193 goto nla_put_failure; 194 if (nft_dump_register(skb, NFTA_LOOKUP_SREG, priv->sreg)) 195 goto nla_put_failure; 196 if (priv->dreg_set) 197 if (nft_dump_register(skb, NFTA_LOOKUP_DREG, priv->dreg)) 198 goto nla_put_failure; 199 if (nla_put_be32(skb, NFTA_LOOKUP_FLAGS, htonl(flags))) 200 goto nla_put_failure; 201 return 0; 202 203 nla_put_failure: 204 return -1; 205 } 206 207 static int nft_lookup_validate(const struct nft_ctx *ctx, 208 const struct nft_expr *expr, 209 const struct nft_data **d) 210 { 211 const struct nft_lookup *priv = nft_expr_priv(expr); 212 struct nft_set_iter iter; 213 214 if (!(priv->set->flags & NFT_SET_MAP) || 215 priv->set->dtype != NFT_DATA_VERDICT) 216 return 0; 217 218 iter.genmask = nft_genmask_next(ctx->net); 219 iter.skip = 0; 220 iter.count = 0; 221 iter.err = 0; 222 iter.fn = nft_setelem_validate; 223 224 priv->set->ops->walk(ctx, priv->set, &iter); 225 if (!iter.err) 226 iter.err = nft_set_catchall_validate(ctx, priv->set); 227 228 if (iter.err < 0) 229 return iter.err; 230 231 return 0; 232 } 233 234 static bool nft_lookup_reduce(struct nft_regs_track *track, 235 const struct nft_expr *expr) 236 { 237 const struct nft_lookup *priv = nft_expr_priv(expr); 238 239 if (priv->set->flags & NFT_SET_MAP) 240 nft_reg_track_cancel(track, priv->dreg, priv->set->dlen); 241 242 return false; 243 } 244 245 static const struct nft_expr_ops nft_lookup_ops = { 246 .type = &nft_lookup_type, 247 .size = NFT_EXPR_SIZE(sizeof(struct nft_lookup)), 248 .eval = nft_lookup_eval, 249 .init = nft_lookup_init, 250 .activate = nft_lookup_activate, 251 .deactivate = nft_lookup_deactivate, 252 .destroy = nft_lookup_destroy, 253 .dump = nft_lookup_dump, 254 .validate = nft_lookup_validate, 255 .reduce = nft_lookup_reduce, 256 }; 257 258 struct nft_expr_type nft_lookup_type __read_mostly = { 259 .name = "lookup", 260 .ops = &nft_lookup_ops, 261 .policy = nft_lookup_policy, 262 .maxattr = NFTA_LOOKUP_MAX, 263 .owner = THIS_MODULE, 264 }; 265