projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 96518518 PM |
1 | /* |
| 2 | * Copyright (c) 2008 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/module.h> | |
| 14 | #include <linux/netlink.h> | |
| 15 | #include <linux/netfilter.h> | |
| 16 | #include <linux/netfilter/nf_tables.h> | |
| 17 | #include <net/netfilter/nf_tables_core.h> | |
| 18 | #include <net/netfilter/nf_tables.h> | |
| 19 | ||
| 20 | struct nft_cmp_expr { | |
| 21 | struct nft_data data; | |
| 22 | enum nft_registers sreg:8; | |
| 23 | u8 len; | |
| 24 | enum nft_cmp_ops op:8; | |
| 25 | }; | |
| 26 | ||
| 27 | static void nft_cmp_eval(const struct nft_expr *expr, | |
| 28 | struct nft_data data[NFT_REG_MAX + 1], | |
| 29 | const struct nft_pktinfo *pkt) | |
| 30 | { | |
| 31 | const struct nft_cmp_expr *priv = nft_expr_priv(expr); | |
| 32 | int d; | |
| 33 | ||
| 34 | d = nft_data_cmp(&data[priv->sreg], &priv->data, priv->len); | |
| 35 | switch (priv->op) { | |
| 36 | case NFT_CMP_EQ: | |
| 37 | if (d != 0) | |
| 38 | goto mismatch; | |
| 39 | break; | |
| 40 | case NFT_CMP_NEQ: | |
| 41 | if (d == 0) | |
| 42 | goto mismatch; | |
| 43 | break; | |
| 44 | case NFT_CMP_LT: | |
| 45 | if (d == 0) | |
| 46 | goto mismatch; | |
| 47 | case NFT_CMP_LTE: | |
| 48 | if (d > 0) | |
| 49 | goto mismatch; | |
| 50 | break; | |
| 51 | case NFT_CMP_GT: | |
| 52 | if (d == 0) | |
| 53 | goto mismatch; | |
| 54 | case NFT_CMP_GTE: | |
| 55 | if (d < 0) | |
| 56 | goto mismatch; | |
| 57 | break; | |
| 58 | } | |
| 59 | return; | |
| 60 | ||
| 61 | mismatch: | |
| 62 | data[NFT_REG_VERDICT].verdict = NFT_BREAK; | |
| 63 | } | |
| 64 | ||
| 65 | static const struct nla_policy nft_cmp_policy[NFTA_CMP_MAX + 1] = { | |
| 66 | [NFTA_CMP_SREG] = { .type = NLA_U32 }, | |
| 67 | [NFTA_CMP_OP] = { .type = NLA_U32 }, | |
| 68 | [NFTA_CMP_DATA] = { .type = NLA_NESTED }, | |
| 69 | }; | |
| 70 | ||
| 71 | static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr, | |
| 72 | const struct nlattr * const tb[]) | |
| 73 | { | |
| 74 | struct nft_cmp_expr *priv = nft_expr_priv(expr); | |
| 75 | struct nft_data_desc desc; | |
| 76 | int err; | |
| 77 | ||
| 78 | if (tb[NFTA_CMP_SREG] == NULL || | |
| 79 | tb[NFTA_CMP_OP] == NULL || | |
| 80 | tb[NFTA_CMP_DATA] == NULL) | |
| 81 | return -EINVAL; | |
| 82 | ||
| 83 | priv->sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG])); | |
| 84 | err = nft_validate_input_register(priv->sreg); | |
| 85 | if (err < 0) | |
| 86 | return err; | |
| 87 | ||
| 88 | priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP])); | |
| 89 | switch (priv->op) { | |
| 90 | case NFT_CMP_EQ: | |
| 91 | case NFT_CMP_NEQ: | |
| 92 | case NFT_CMP_LT: | |
| 93 | case NFT_CMP_LTE: | |
| 94 | case NFT_CMP_GT: | |
| 95 | case NFT_CMP_GTE: | |
| 96 | break; | |
| 97 | default: | |
| 98 | return -EINVAL; | |
| 99 | } | |
| 100 | ||
| 101 | err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_CMP_DATA]); | |
| 102 | if (err < 0) | |
| 103 | return err; | |
| 104 | ||
| 105 | priv->len = desc.len; | |
| 106 | return 0; | |
| 107 | } | |
| 108 | ||
| 109 | static int nft_cmp_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
| 110 | { | |
| 111 | const struct nft_cmp_expr *priv = nft_expr_priv(expr); | |
| 112 | ||
| 113 | if (nla_put_be32(skb, NFTA_CMP_SREG, htonl(priv->sreg))) | |
| 114 | goto nla_put_failure; | |
| 115 | if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op))) | |
| 116 | goto nla_put_failure; | |
| 117 | ||
| 118 | if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data, | |
| 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 struct nft_expr_ops nft_cmp_ops __read_mostly = { | |
| 128 | .name = "cmp", | |
| 129 | .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)), | |
| 130 | .owner = THIS_MODULE, | |
| 131 | .eval = nft_cmp_eval, | |
| 132 | .init = nft_cmp_init, | |
| 133 | .dump = nft_cmp_dump, | |
| 134 | .policy = nft_cmp_policy, | |
| 135 | .maxattr = NFTA_CMP_MAX, | |
| 136 | }; | |
| 137 | ||
| 138 | int __init nft_cmp_module_init(void) | |
| 139 | { | |
| 140 | return nft_register_expr(&nft_cmp_ops); | |
| 141 | } | |
| 142 | ||
| 143 | void nft_cmp_module_exit(void) | |
| 144 | { | |
| 145 | nft_unregister_expr(&nft_cmp_ops); | |
| 146 | } |