1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org> 4 */ 5 6 #include <linux/kernel.h> 7 #include <linux/init.h> 8 #include <linux/module.h> 9 #include <linux/netlink.h> 10 #include <linux/netfilter.h> 11 #include <linux/netfilter/nf_tables.h> 12 #include <net/netfilter/nf_tables_core.h> 13 #include <net/netfilter/nf_tables.h> 14 15 struct nft_range_expr { 16 struct nft_data data_from; 17 struct nft_data data_to; 18 u8 sreg; 19 u8 len; 20 enum nft_range_ops op:8; 21 }; 22 23 void nft_range_eval(const struct nft_expr *expr, 24 struct nft_regs *regs, const struct nft_pktinfo *pkt) 25 { 26 const struct nft_range_expr *priv = nft_expr_priv(expr); 27 int d1, d2; 28 29 d1 = memcmp(®s->data[priv->sreg], &priv->data_from, priv->len); 30 d2 = memcmp(®s->data[priv->sreg], &priv->data_to, priv->len); 31 switch (priv->op) { 32 case NFT_RANGE_EQ: 33 if (d1 < 0 || d2 > 0) 34 regs->verdict.code = NFT_BREAK; 35 break; 36 case NFT_RANGE_NEQ: 37 if (d1 >= 0 && d2 <= 0) 38 regs->verdict.code = NFT_BREAK; 39 break; 40 } 41 } 42 43 static const struct nla_policy nft_range_policy[NFTA_RANGE_MAX + 1] = { 44 [NFTA_RANGE_SREG] = { .type = NLA_U32 }, 45 [NFTA_RANGE_OP] = { .type = NLA_U32 }, 46 [NFTA_RANGE_FROM_DATA] = { .type = NLA_NESTED }, 47 [NFTA_RANGE_TO_DATA] = { .type = NLA_NESTED }, 48 }; 49 50 static int nft_range_init(const struct nft_ctx *ctx, const struct nft_expr *expr, 51 const struct nlattr * const tb[]) 52 { 53 struct nft_range_expr *priv = nft_expr_priv(expr); 54 struct nft_data_desc desc_from = { 55 .type = NFT_DATA_VALUE, 56 .size = sizeof(priv->data_from), 57 }; 58 struct nft_data_desc desc_to = { 59 .type = NFT_DATA_VALUE, 60 .size = sizeof(priv->data_to), 61 }; 62 int err; 63 u32 op; 64 65 if (!tb[NFTA_RANGE_SREG] || 66 !tb[NFTA_RANGE_OP] || 67 !tb[NFTA_RANGE_FROM_DATA] || 68 !tb[NFTA_RANGE_TO_DATA]) 69 return -EINVAL; 70 71 err = nft_data_init(NULL, &priv->data_from, &desc_from, 72 tb[NFTA_RANGE_FROM_DATA]); 73 if (err < 0) 74 return err; 75 76 err = nft_data_init(NULL, &priv->data_to, &desc_to, 77 tb[NFTA_RANGE_TO_DATA]); 78 if (err < 0) 79 goto err1; 80 81 if (desc_from.len != desc_to.len) { 82 err = -EINVAL; 83 goto err2; 84 } 85 86 err = nft_parse_register_load(tb[NFTA_RANGE_SREG], &priv->sreg, 87 desc_from.len); 88 if (err < 0) 89 goto err2; 90 91 err = nft_parse_u32_check(tb[NFTA_RANGE_OP], U8_MAX, &op); 92 if (err < 0) 93 goto err2; 94 95 switch (op) { 96 case NFT_RANGE_EQ: 97 case NFT_RANGE_NEQ: 98 break; 99 default: 100 err = -EINVAL; 101 goto err2; 102 } 103 104 priv->op = op; 105 priv->len = desc_from.len; 106 return 0; 107 err2: 108 nft_data_release(&priv->data_to, desc_to.type); 109 err1: 110 nft_data_release(&priv->data_from, desc_from.type); 111 return err; 112 } 113 114 static int nft_range_dump(struct sk_buff *skb, 115 const struct nft_expr *expr, bool reset) 116 { 117 const struct nft_range_expr *priv = nft_expr_priv(expr); 118 119 if (nft_dump_register(skb, NFTA_RANGE_SREG, priv->sreg)) 120 goto nla_put_failure; 121 if (nla_put_be32(skb, NFTA_RANGE_OP, htonl(priv->op))) 122 goto nla_put_failure; 123 124 if (nft_data_dump(skb, NFTA_RANGE_FROM_DATA, &priv->data_from, 125 NFT_DATA_VALUE, priv->len) < 0 || 126 nft_data_dump(skb, NFTA_RANGE_TO_DATA, &priv->data_to, 127 NFT_DATA_VALUE, priv->len) < 0) 128 goto nla_put_failure; 129 return 0; 130 131 nla_put_failure: 132 return -1; 133 } 134 135 static const struct nft_expr_ops nft_range_ops = { 136 .type = &nft_range_type, 137 .size = NFT_EXPR_SIZE(sizeof(struct nft_range_expr)), 138 .eval = nft_range_eval, 139 .init = nft_range_init, 140 .dump = nft_range_dump, 141 .reduce = NFT_REDUCE_READONLY, 142 }; 143 144 struct nft_expr_type nft_range_type __read_mostly = { 145 .name = "range", 146 .ops = &nft_range_ops, 147 .policy = nft_range_policy, 148 .maxattr = NFTA_RANGE_MAX, 149 .owner = THIS_MODULE, 150 }; 151