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_regs *regs, 28 const struct nft_pktinfo *pkt) 29 { 30 const struct nft_immediate_expr *priv = nft_expr_priv(expr); 31 32 nft_data_copy(®s->data[priv->dreg], &priv->data, priv->dlen); 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 err = nft_data_init(ctx, &priv->data, sizeof(priv->data), &desc, 53 tb[NFTA_IMMEDIATE_DATA]); 54 if (err < 0) 55 return err; 56 priv->dlen = desc.len; 57 58 priv->dreg = nft_parse_register(tb[NFTA_IMMEDIATE_DREG]); 59 err = nft_validate_register_store(ctx, priv->dreg, &priv->data, 60 desc.type, desc.len); 61 if (err < 0) 62 goto err1; 63 64 return 0; 65 66 err1: 67 nft_data_uninit(&priv->data, desc.type); 68 return err; 69 } 70 71 static void nft_immediate_destroy(const struct nft_ctx *ctx, 72 const struct nft_expr *expr) 73 { 74 const struct nft_immediate_expr *priv = nft_expr_priv(expr); 75 return nft_data_uninit(&priv->data, nft_dreg_to_type(priv->dreg)); 76 } 77 78 static int nft_immediate_dump(struct sk_buff *skb, const struct nft_expr *expr) 79 { 80 const struct nft_immediate_expr *priv = nft_expr_priv(expr); 81 82 if (nft_dump_register(skb, NFTA_IMMEDIATE_DREG, priv->dreg)) 83 goto nla_put_failure; 84 85 return nft_data_dump(skb, NFTA_IMMEDIATE_DATA, &priv->data, 86 nft_dreg_to_type(priv->dreg), priv->dlen); 87 88 nla_put_failure: 89 return -1; 90 } 91 92 static int nft_immediate_validate(const struct nft_ctx *ctx, 93 const struct nft_expr *expr, 94 const struct nft_data **data) 95 { 96 const struct nft_immediate_expr *priv = nft_expr_priv(expr); 97 98 if (priv->dreg == NFT_REG_VERDICT) 99 *data = &priv->data; 100 101 return 0; 102 } 103 104 static struct nft_expr_type nft_imm_type; 105 static const struct nft_expr_ops nft_imm_ops = { 106 .type = &nft_imm_type, 107 .size = NFT_EXPR_SIZE(sizeof(struct nft_immediate_expr)), 108 .eval = nft_immediate_eval, 109 .init = nft_immediate_init, 110 .destroy = nft_immediate_destroy, 111 .dump = nft_immediate_dump, 112 .validate = nft_immediate_validate, 113 }; 114 115 static struct nft_expr_type nft_imm_type __read_mostly = { 116 .name = "immediate", 117 .ops = &nft_imm_ops, 118 .policy = nft_immediate_policy, 119 .maxattr = NFTA_IMMEDIATE_MAX, 120 .owner = THIS_MODULE, 121 }; 122 123 int __init nft_immediate_module_init(void) 124 { 125 return nft_register_expr(&nft_imm_type); 126 } 127 128 void nft_immediate_module_exit(void) 129 { 130 nft_unregister_expr(&nft_imm_type); 131 } 132