| 1 | /* |
| 2 | * Copyright (c) 2008-2009 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/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_immediate_expr { |
| 21 | struct nft_data data; |
| 22 | enum nft_registers dreg:8; |
| 23 | u8 dlen; |
| 24 | }; |
| 25 | |
| 26 | static void nft_immediate_eval(const struct nft_expr *expr, |
| 27 | struct nft_data data[NFT_REG_MAX + 1], |
| 28 | const struct nft_pktinfo *pkt) |
| 29 | { |
| 30 | const struct nft_immediate_expr *priv = nft_expr_priv(expr); |
| 31 | |
| 32 | nft_data_copy(&data[priv->dreg], &priv->data); |
| 33 | } |
| 34 | |
| 35 | static const struct nla_policy nft_immediate_policy[NFTA_IMMEDIATE_MAX + 1] = { |
| 36 | [NFTA_IMMEDIATE_DREG] = { .type = NLA_U32 }, |
| 37 | [NFTA_IMMEDIATE_DATA] = { .type = NLA_NESTED }, |
| 38 | }; |
| 39 | |
| 40 | static int nft_immediate_init(const struct nft_ctx *ctx, |
| 41 | const struct nft_expr *expr, |
| 42 | const struct nlattr * const tb[]) |
| 43 | { |
| 44 | struct nft_immediate_expr *priv = nft_expr_priv(expr); |
| 45 | struct nft_data_desc desc; |
| 46 | int err; |
| 47 | |
| 48 | if (tb[NFTA_IMMEDIATE_DREG] == NULL || |
| 49 | tb[NFTA_IMMEDIATE_DATA] == NULL) |
| 50 | return -EINVAL; |
| 51 | |
| 52 | priv->dreg = ntohl(nla_get_be32(tb[NFTA_IMMEDIATE_DREG])); |
| 53 | err = nft_validate_output_register(priv->dreg); |
| 54 | if (err < 0) |
| 55 | return err; |
| 56 | |
| 57 | err = nft_data_init(ctx, &priv->data, &desc, tb[NFTA_IMMEDIATE_DATA]); |
| 58 | if (err < 0) |
| 59 | return err; |
| 60 | priv->dlen = desc.len; |
| 61 | |
| 62 | err = nft_validate_data_load(ctx, priv->dreg, &priv->data, desc.type); |
| 63 | if (err < 0) |
| 64 | goto err1; |
| 65 | |
| 66 | return 0; |
| 67 | |
| 68 | err1: |
| 69 | nft_data_uninit(&priv->data, desc.type); |
| 70 | return err; |
| 71 | } |
| 72 | |
| 73 | static void nft_immediate_destroy(const struct nft_ctx *ctx, |
| 74 | const struct nft_expr *expr) |
| 75 | { |
| 76 | const struct nft_immediate_expr *priv = nft_expr_priv(expr); |
| 77 | return nft_data_uninit(&priv->data, nft_dreg_to_type(priv->dreg)); |
| 78 | } |
| 79 | |
| 80 | static int nft_immediate_dump(struct sk_buff *skb, const struct nft_expr *expr) |
| 81 | { |
| 82 | const struct nft_immediate_expr *priv = nft_expr_priv(expr); |
| 83 | |
| 84 | if (nla_put_be32(skb, NFTA_IMMEDIATE_DREG, htonl(priv->dreg))) |
| 85 | goto nla_put_failure; |
| 86 | |
| 87 | return nft_data_dump(skb, NFTA_IMMEDIATE_DATA, &priv->data, |
| 88 | nft_dreg_to_type(priv->dreg), priv->dlen); |
| 89 | |
| 90 | nla_put_failure: |
| 91 | return -1; |
| 92 | } |
| 93 | |
| 94 | static int nft_immediate_validate(const struct nft_ctx *ctx, |
| 95 | const struct nft_expr *expr, |
| 96 | const struct nft_data **data) |
| 97 | { |
| 98 | const struct nft_immediate_expr *priv = nft_expr_priv(expr); |
| 99 | |
| 100 | if (priv->dreg == NFT_REG_VERDICT) |
| 101 | *data = &priv->data; |
| 102 | |
| 103 | return 0; |
| 104 | } |
| 105 | |
| 106 | static struct nft_expr_type nft_imm_type; |
| 107 | static const struct nft_expr_ops nft_imm_ops = { |
| 108 | .type = &nft_imm_type, |
| 109 | .size = NFT_EXPR_SIZE(sizeof(struct nft_immediate_expr)), |
| 110 | .eval = nft_immediate_eval, |
| 111 | .init = nft_immediate_init, |
| 112 | .destroy = nft_immediate_destroy, |
| 113 | .dump = nft_immediate_dump, |
| 114 | .validate = nft_immediate_validate, |
| 115 | }; |
| 116 | |
| 117 | static struct nft_expr_type nft_imm_type __read_mostly = { |
| 118 | .name = "immediate", |
| 119 | .ops = &nft_imm_ops, |
| 120 | .policy = nft_immediate_policy, |
| 121 | .maxattr = NFTA_IMMEDIATE_MAX, |
| 122 | .owner = THIS_MODULE, |
| 123 | }; |
| 124 | |
| 125 | int __init nft_immediate_module_init(void) |
| 126 | { |
| 127 | return nft_register_expr(&nft_imm_type); |
| 128 | } |
| 129 | |
| 130 | void nft_immediate_module_exit(void) |
| 131 | { |
| 132 | nft_unregister_expr(&nft_imm_type); |
| 133 | } |