1 /* 2 * Copyright (c) 2009 Patrick McHardy <kaber@trash.net> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * Development of this code funded by Astaro AG (http://www.astaro.com/) 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/init.h> 13 #include <linux/list.h> 14 #include <linux/rbtree.h> 15 #include <linux/netlink.h> 16 #include <linux/netfilter.h> 17 #include <linux/netfilter/nf_tables.h> 18 #include <net/netfilter/nf_tables.h> 19 #include <net/netfilter/nf_tables_core.h> 20 21 struct nft_lookup { 22 struct nft_set *set; 23 enum nft_registers sreg:8; 24 enum nft_registers dreg:8; 25 struct nft_set_binding binding; 26 }; 27 28 static void nft_lookup_eval(const struct nft_expr *expr, 29 struct nft_data data[NFT_REG_MAX + 1], 30 const struct nft_pktinfo *pkt) 31 { 32 const struct nft_lookup *priv = nft_expr_priv(expr); 33 const struct nft_set *set = priv->set; 34 35 if (set->ops->lookup(set, &data[priv->sreg], &data[priv->dreg])) 36 return; 37 data[NFT_REG_VERDICT].verdict = NFT_BREAK; 38 } 39 40 static const struct nla_policy nft_lookup_policy[NFTA_LOOKUP_MAX + 1] = { 41 [NFTA_LOOKUP_SET] = { .type = NLA_STRING }, 42 [NFTA_LOOKUP_SET_ID] = { .type = NLA_U32 }, 43 [NFTA_LOOKUP_SREG] = { .type = NLA_U32 }, 44 [NFTA_LOOKUP_DREG] = { .type = NLA_U32 }, 45 }; 46 47 static int nft_lookup_init(const struct nft_ctx *ctx, 48 const struct nft_expr *expr, 49 const struct nlattr * const tb[]) 50 { 51 struct nft_lookup *priv = nft_expr_priv(expr); 52 struct nft_set *set; 53 int err; 54 55 if (tb[NFTA_LOOKUP_SET] == NULL || 56 tb[NFTA_LOOKUP_SREG] == NULL) 57 return -EINVAL; 58 59 set = nf_tables_set_lookup(ctx->table, tb[NFTA_LOOKUP_SET]); 60 if (IS_ERR(set)) { 61 if (tb[NFTA_LOOKUP_SET_ID]) { 62 set = nf_tables_set_lookup_byid(ctx->net, 63 tb[NFTA_LOOKUP_SET_ID]); 64 } 65 if (IS_ERR(set)) 66 return PTR_ERR(set); 67 } 68 69 priv->sreg = ntohl(nla_get_be32(tb[NFTA_LOOKUP_SREG])); 70 err = nft_validate_input_register(priv->sreg); 71 if (err < 0) 72 return err; 73 74 if (tb[NFTA_LOOKUP_DREG] != NULL) { 75 if (!(set->flags & NFT_SET_MAP)) 76 return -EINVAL; 77 78 priv->dreg = ntohl(nla_get_be32(tb[NFTA_LOOKUP_DREG])); 79 err = nft_validate_output_register(priv->dreg); 80 if (err < 0) 81 return err; 82 83 if (priv->dreg == NFT_REG_VERDICT) { 84 if (set->dtype != NFT_DATA_VERDICT) 85 return -EINVAL; 86 } else if (set->dtype == NFT_DATA_VERDICT) 87 return -EINVAL; 88 } else if (set->flags & NFT_SET_MAP) 89 return -EINVAL; 90 91 err = nf_tables_bind_set(ctx, set, &priv->binding); 92 if (err < 0) 93 return err; 94 95 priv->set = set; 96 return 0; 97 } 98 99 static void nft_lookup_destroy(const struct nft_ctx *ctx, 100 const struct nft_expr *expr) 101 { 102 struct nft_lookup *priv = nft_expr_priv(expr); 103 104 nf_tables_unbind_set(ctx, priv->set, &priv->binding); 105 } 106 107 static int nft_lookup_dump(struct sk_buff *skb, const struct nft_expr *expr) 108 { 109 const struct nft_lookup *priv = nft_expr_priv(expr); 110 111 if (nla_put_string(skb, NFTA_LOOKUP_SET, priv->set->name)) 112 goto nla_put_failure; 113 if (nla_put_be32(skb, NFTA_LOOKUP_SREG, htonl(priv->sreg))) 114 goto nla_put_failure; 115 if (priv->set->flags & NFT_SET_MAP) 116 if (nla_put_be32(skb, NFTA_LOOKUP_DREG, htonl(priv->dreg))) 117 goto nla_put_failure; 118 return 0; 119 120 nla_put_failure: 121 return -1; 122 } 123 124 static struct nft_expr_type nft_lookup_type; 125 static const struct nft_expr_ops nft_lookup_ops = { 126 .type = &nft_lookup_type, 127 .size = NFT_EXPR_SIZE(sizeof(struct nft_lookup)), 128 .eval = nft_lookup_eval, 129 .init = nft_lookup_init, 130 .destroy = nft_lookup_destroy, 131 .dump = nft_lookup_dump, 132 }; 133 134 static struct nft_expr_type nft_lookup_type __read_mostly = { 135 .name = "lookup", 136 .ops = &nft_lookup_ops, 137 .policy = nft_lookup_policy, 138 .maxattr = NFTA_LOOKUP_MAX, 139 .owner = THIS_MODULE, 140 }; 141 142 int __init nft_lookup_module_init(void) 143 { 144 return nft_register_expr(&nft_lookup_type); 145 } 146 147 void nft_lookup_module_exit(void) 148 { 149 nft_unregister_expr(&nft_lookup_type); 150 } 151