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 enum nft_registers sreg:8; 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, desc_to; 55 int err; 56 u32 op; 57 58 if (!tb[NFTA_RANGE_SREG] || 59 !tb[NFTA_RANGE_OP] || 60 !tb[NFTA_RANGE_FROM_DATA] || 61 !tb[NFTA_RANGE_TO_DATA]) 62 return -EINVAL; 63 64 err = nft_data_init(NULL, &priv->data_from, sizeof(priv->data_from), 65 &desc_from, tb[NFTA_RANGE_FROM_DATA]); 66 if (err < 0) 67 return err; 68 69 err = nft_data_init(NULL, &priv->data_to, sizeof(priv->data_to), 70 &desc_to, tb[NFTA_RANGE_TO_DATA]); 71 if (err < 0) 72 goto err1; 73 74 if (desc_from.len != desc_to.len) { 75 err = -EINVAL; 76 goto err2; 77 } 78 79 priv->sreg = nft_parse_register(tb[NFTA_RANGE_SREG]); 80 err = nft_validate_register_load(priv->sreg, desc_from.len); 81 if (err < 0) 82 goto err2; 83 84 err = nft_parse_u32_check(tb[NFTA_RANGE_OP], U8_MAX, &op); 85 if (err < 0) 86 goto err2; 87 88 switch (op) { 89 case NFT_RANGE_EQ: 90 case NFT_RANGE_NEQ: 91 break; 92 default: 93 err = -EINVAL; 94 goto err2; 95 } 96 97 priv->op = op; 98 priv->len = desc_from.len; 99 return 0; 100 err2: 101 nft_data_release(&priv->data_to, desc_to.type); 102 err1: 103 nft_data_release(&priv->data_from, desc_from.type); 104 return err; 105 } 106 107 static int nft_range_dump(struct sk_buff *skb, const struct nft_expr *expr) 108 { 109 const struct nft_range_expr *priv = nft_expr_priv(expr); 110 111 if (nft_dump_register(skb, NFTA_RANGE_SREG, priv->sreg)) 112 goto nla_put_failure; 113 if (nla_put_be32(skb, NFTA_RANGE_OP, htonl(priv->op))) 114 goto nla_put_failure; 115 116 if (nft_data_dump(skb, NFTA_RANGE_FROM_DATA, &priv->data_from, 117 NFT_DATA_VALUE, priv->len) < 0 || 118 nft_data_dump(skb, NFTA_RANGE_TO_DATA, &priv->data_to, 119 NFT_DATA_VALUE, priv->len) < 0) 120 goto nla_put_failure; 121 return 0; 122 123 nla_put_failure: 124 return -1; 125 } 126 127 static const struct nft_expr_ops nft_range_ops = { 128 .type = &nft_range_type, 129 .size = NFT_EXPR_SIZE(sizeof(struct nft_range_expr)), 130 .eval = nft_range_eval, 131 .init = nft_range_init, 132 .dump = nft_range_dump, 133 }; 134 135 struct nft_expr_type nft_range_type __read_mostly = { 136 .name = "range", 137 .ops = &nft_range_ops, 138 .policy = nft_range_policy, 139 .maxattr = NFTA_RANGE_MAX, 140 .owner = THIS_MODULE, 141 }; 142