net/netfilter/nft_immediate.c

   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 static void nft_immediate_eval(const struct nft_expr *expr,
  21                                struct nft_regs *regs,
  22                                const struct nft_pktinfo *pkt)
  23 {
  24         const struct nft_immediate_expr *priv = nft_expr_priv(expr);
  25
  26         nft_data_copy(&regs->data[priv->dreg], &priv->data, priv->dlen);
  27 }
  28
  29 static const struct nla_policy nft_immediate_policy[NFTA_IMMEDIATE_MAX + 1] = {
  30         [NFTA_IMMEDIATE_DREG]   = { .type = NLA_U32 },
  31         [NFTA_IMMEDIATE_DATA]   = { .type = NLA_NESTED },
  32 };
  33
  34 static int nft_immediate_init(const struct nft_ctx *ctx,
  35                               const struct nft_expr *expr,
  36                               const struct nlattr * const tb[])
  37 {
  38         struct nft_immediate_expr *priv = nft_expr_priv(expr);
  39         struct nft_data_desc desc;
  40         int err;
  41
  42         if (tb[NFTA_IMMEDIATE_DREG] == NULL ||
  43             tb[NFTA_IMMEDIATE_DATA] == NULL)
  44                 return -EINVAL;
  45
  46         err = nft_data_init(ctx, &priv->data, sizeof(priv->data), &desc,
  47                             tb[NFTA_IMMEDIATE_DATA]);
  48         if (err < 0)
  49                 return err;
  50
  51         priv->dlen = desc.len;
  52
  53         priv->dreg = nft_parse_register(tb[NFTA_IMMEDIATE_DREG]);
  54         err = nft_validate_register_store(ctx, priv->dreg, &priv->data,
  55                                           desc.type, desc.len);
  56         if (err < 0)
  57                 goto err1;
  58
  59         return 0;
  60
  61 err1:
  62         nft_data_release(&priv->data, desc.type);
  63         return err;
  64 }
  65
  66 static void nft_immediate_activate(const struct nft_ctx *ctx,
  67                                    const struct nft_expr *expr)
  68 {
  69         const struct nft_immediate_expr *priv = nft_expr_priv(expr);
  70
  71         return nft_data_hold(&priv->data, nft_dreg_to_type(priv->dreg));
  72 }
  73
  74 static void nft_immediate_deactivate(const struct nft_ctx *ctx,
  75                                      const struct nft_expr *expr,
  76                                      enum nft_trans_phase phase)
  77 {
  78         const struct nft_immediate_expr *priv = nft_expr_priv(expr);
  79
  80         if (phase == NFT_TRANS_COMMIT)
  81                 return;
  82
  83         return nft_data_release(&priv->data, nft_dreg_to_type(priv->dreg));
  84 }
  85
  86 static int nft_immediate_dump(struct sk_buff *skb, const struct nft_expr *expr)
  87 {
  88         const struct nft_immediate_expr *priv = nft_expr_priv(expr);
  89
  90         if (nft_dump_register(skb, NFTA_IMMEDIATE_DREG, priv->dreg))
  91                 goto nla_put_failure;
  92
  93         return nft_data_dump(skb, NFTA_IMMEDIATE_DATA, &priv->data,
  94                              nft_dreg_to_type(priv->dreg), priv->dlen);
  95
  96 nla_put_failure:
  97         return -1;
  98 }
  99
 100 static int nft_immediate_validate(const struct nft_ctx *ctx,
 101                                   const struct nft_expr *expr,
 102                                   const struct nft_data **d)
 103 {
 104         const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 105         struct nft_ctx *pctx = (struct nft_ctx *)ctx;
 106         const struct nft_data *data;
 107         int err;
 108
 109         if (priv->dreg != NFT_REG_VERDICT)
 110                 return 0;
 111
 112         data = &priv->data;
 113
 114         switch (data->verdict.code) {
 115         case NFT_JUMP:
 116         case NFT_GOTO:
 117                 pctx->level++;
 118                 err = nft_chain_validate(ctx, data->verdict.chain);
 119                 if (err < 0)
 120                         return err;
 121                 pctx->level--;
 122                 break;
 123         default:
 124                 break;
 125         }
 126
 127         return 0;
 128 }
 129
 130 static const struct nft_expr_ops nft_imm_ops = {
 131         .type           = &nft_imm_type,
 132         .size           = NFT_EXPR_SIZE(sizeof(struct nft_immediate_expr)),
 133         .eval           = nft_immediate_eval,
 134         .init           = nft_immediate_init,
 135         .activate       = nft_immediate_activate,
 136         .deactivate     = nft_immediate_deactivate,
 137         .dump           = nft_immediate_dump,
 138         .validate       = nft_immediate_validate,
 139 };
 140
 141 struct nft_expr_type nft_imm_type __read_mostly = {
 142         .name           = "immediate",
 143         .ops            = &nft_imm_ops,
 144         .policy         = nft_immediate_policy,
 145         .maxattr        = NFTA_IMMEDIATE_MAX,
 146         .owner          = THIS_MODULE,
 147 };