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 {
  77         const struct nft_immediate_expr *priv = nft_expr_priv(expr);
  78
  79         return nft_data_release(&priv->data, nft_dreg_to_type(priv->dreg));
  80 }
  81
  82 static int nft_immediate_dump(struct sk_buff *skb, const struct nft_expr *expr)
  83 {
  84         const struct nft_immediate_expr *priv = nft_expr_priv(expr);
  85
  86         if (nft_dump_register(skb, NFTA_IMMEDIATE_DREG, priv->dreg))
  87                 goto nla_put_failure;
  88
  89         return nft_data_dump(skb, NFTA_IMMEDIATE_DATA, &priv->data,
  90                              nft_dreg_to_type(priv->dreg), priv->dlen);
  91
  92 nla_put_failure:
  93         return -1;
  94 }
  95
  96 static int nft_immediate_validate(const struct nft_ctx *ctx,
  97                                   const struct nft_expr *expr,
  98                                   const struct nft_data **d)
  99 {
 100         const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 101         struct nft_ctx *pctx = (struct nft_ctx *)ctx;
 102         const struct nft_data *data;
 103         int err;
 104
 105         if (priv->dreg != NFT_REG_VERDICT)
 106                 return 0;
 107
 108         data = &priv->data;
 109
 110         switch (data->verdict.code) {
 111         case NFT_JUMP:
 112         case NFT_GOTO:
 113                 pctx->level++;
 114                 err = nft_chain_validate(ctx, data->verdict.chain);
 115                 if (err < 0)
 116                         return err;
 117                 pctx->level--;
 118                 break;
 119         default:
 120                 break;
 121         }
 122
 123         return 0;
 124 }
 125
 126 static const struct nft_expr_ops nft_imm_ops = {
 127         .type           = &nft_imm_type,
 128         .size           = NFT_EXPR_SIZE(sizeof(struct nft_immediate_expr)),
 129         .eval           = nft_immediate_eval,
 130         .init           = nft_immediate_init,
 131         .activate       = nft_immediate_activate,
 132         .deactivate     = nft_immediate_deactivate,
 133         .dump           = nft_immediate_dump,
 134         .validate       = nft_immediate_validate,
 135 };
 136
 137 struct nft_expr_type nft_imm_type __read_mostly = {
 138         .name           = "immediate",
 139         .ops            = &nft_imm_ops,
 140         .policy         = nft_immediate_policy,
 141         .maxattr        = NFTA_IMMEDIATE_MAX,
 142         .owner          = THIS_MODULE,
 143 };