Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 1 | /* |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 2 | * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 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_bitwise { |
| 21 | enum nft_registers sreg:8; |
| 22 | enum nft_registers dreg:8; |
| 23 | u8 len; |
| 24 | struct nft_data mask; |
| 25 | struct nft_data xor; |
| 26 | }; |
| 27 | |
| 28 | static void nft_bitwise_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_bitwise *priv = nft_expr_priv(expr); |
| 33 | const struct nft_data *src = &data[priv->sreg]; |
| 34 | struct nft_data *dst = &data[priv->dreg]; |
| 35 | unsigned int i; |
| 36 | |
| 37 | for (i = 0; i < DIV_ROUND_UP(priv->len, 4); i++) { |
| 38 | dst->data[i] = (src->data[i] & priv->mask.data[i]) ^ |
| 39 | priv->xor.data[i]; |
| 40 | } |
| 41 | } |
| 42 | |
| 43 | static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = { |
| 44 | [NFTA_BITWISE_SREG] = { .type = NLA_U32 }, |
| 45 | [NFTA_BITWISE_DREG] = { .type = NLA_U32 }, |
| 46 | [NFTA_BITWISE_LEN] = { .type = NLA_U32 }, |
| 47 | [NFTA_BITWISE_MASK] = { .type = NLA_NESTED }, |
| 48 | [NFTA_BITWISE_XOR] = { .type = NLA_NESTED }, |
| 49 | }; |
| 50 | |
| 51 | static int nft_bitwise_init(const struct nft_ctx *ctx, |
| 52 | const struct nft_expr *expr, |
| 53 | const struct nlattr * const tb[]) |
| 54 | { |
| 55 | struct nft_bitwise *priv = nft_expr_priv(expr); |
| 56 | struct nft_data_desc d1, d2; |
| 57 | int err; |
| 58 | |
| 59 | if (tb[NFTA_BITWISE_SREG] == NULL || |
| 60 | tb[NFTA_BITWISE_DREG] == NULL || |
| 61 | tb[NFTA_BITWISE_LEN] == NULL || |
| 62 | tb[NFTA_BITWISE_MASK] == NULL || |
| 63 | tb[NFTA_BITWISE_XOR] == NULL) |
| 64 | return -EINVAL; |
| 65 | |
Patrick McHardy | d07db98 | 2015-04-11 02:27:30 +0100 | [diff] [blame^] | 66 | priv->len = ntohl(nla_get_be32(tb[NFTA_BITWISE_LEN])); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 67 | priv->sreg = ntohl(nla_get_be32(tb[NFTA_BITWISE_SREG])); |
Patrick McHardy | d07db98 | 2015-04-11 02:27:30 +0100 | [diff] [blame^] | 68 | err = nft_validate_register_load(priv->sreg, priv->len); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 69 | if (err < 0) |
| 70 | return err; |
| 71 | |
| 72 | priv->dreg = ntohl(nla_get_be32(tb[NFTA_BITWISE_DREG])); |
Patrick McHardy | 1ec1021 | 2015-04-11 02:27:27 +0100 | [diff] [blame] | 73 | err = nft_validate_register_store(ctx, priv->dreg, NULL, |
| 74 | NFT_DATA_VALUE, priv->len); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 75 | if (err < 0) |
| 76 | return err; |
| 77 | |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 78 | err = nft_data_init(NULL, &priv->mask, &d1, tb[NFTA_BITWISE_MASK]); |
| 79 | if (err < 0) |
| 80 | return err; |
| 81 | if (d1.len != priv->len) |
| 82 | return -EINVAL; |
| 83 | |
| 84 | err = nft_data_init(NULL, &priv->xor, &d2, tb[NFTA_BITWISE_XOR]); |
| 85 | if (err < 0) |
| 86 | return err; |
| 87 | if (d2.len != priv->len) |
| 88 | return -EINVAL; |
| 89 | |
| 90 | return 0; |
| 91 | } |
| 92 | |
| 93 | static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr) |
| 94 | { |
| 95 | const struct nft_bitwise *priv = nft_expr_priv(expr); |
| 96 | |
| 97 | if (nla_put_be32(skb, NFTA_BITWISE_SREG, htonl(priv->sreg))) |
| 98 | goto nla_put_failure; |
| 99 | if (nla_put_be32(skb, NFTA_BITWISE_DREG, htonl(priv->dreg))) |
| 100 | goto nla_put_failure; |
| 101 | if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len))) |
| 102 | goto nla_put_failure; |
| 103 | |
| 104 | if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask, |
| 105 | NFT_DATA_VALUE, priv->len) < 0) |
| 106 | goto nla_put_failure; |
| 107 | |
| 108 | if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor, |
| 109 | NFT_DATA_VALUE, priv->len) < 0) |
| 110 | goto nla_put_failure; |
| 111 | |
| 112 | return 0; |
| 113 | |
| 114 | nla_put_failure: |
| 115 | return -1; |
| 116 | } |
| 117 | |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 118 | static struct nft_expr_type nft_bitwise_type; |
| 119 | static const struct nft_expr_ops nft_bitwise_ops = { |
| 120 | .type = &nft_bitwise_type, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 121 | .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)), |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 122 | .eval = nft_bitwise_eval, |
| 123 | .init = nft_bitwise_init, |
| 124 | .dump = nft_bitwise_dump, |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 125 | }; |
| 126 | |
| 127 | static struct nft_expr_type nft_bitwise_type __read_mostly = { |
| 128 | .name = "bitwise", |
| 129 | .ops = &nft_bitwise_ops, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 130 | .policy = nft_bitwise_policy, |
| 131 | .maxattr = NFTA_BITWISE_MAX, |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 132 | .owner = THIS_MODULE, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 133 | }; |
| 134 | |
| 135 | int __init nft_bitwise_module_init(void) |
| 136 | { |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 137 | return nft_register_expr(&nft_bitwise_type); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 138 | } |
| 139 | |
| 140 | void nft_bitwise_module_exit(void) |
| 141 | { |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 142 | nft_unregister_expr(&nft_bitwise_type); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 143 | } |