net/netfilter/nft_immediate.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
   4  *
   5  * Development of this code funded by Astaro AG (http://www.astaro.com/)
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/init.h>
  10 #include <linux/module.h>
  11 #include <linux/netlink.h>
  12 #include <linux/netfilter.h>
  13 #include <linux/netfilter/nf_tables.h>
  14 #include <net/netfilter/nf_tables_core.h>
  15 #include <net/netfilter/nf_tables.h>
  16
  17 void nft_immediate_eval(const struct nft_expr *expr,
  18                         struct nft_regs *regs,
  19                         const struct nft_pktinfo *pkt)
  20 {
  21         const struct nft_immediate_expr *priv = nft_expr_priv(expr);
  22
  23         nft_data_copy(&regs->data[priv->dreg], &priv->data, priv->dlen);
  24 }
  25
  26 static const struct nla_policy nft_immediate_policy[NFTA_IMMEDIATE_MAX + 1] = {
  27         [NFTA_IMMEDIATE_DREG]   = { .type = NLA_U32 },
  28         [NFTA_IMMEDIATE_DATA]   = { .type = NLA_NESTED },
  29 };
  30
  31 static int nft_immediate_init(const struct nft_ctx *ctx,
  32                               const struct nft_expr *expr,
  33                               const struct nlattr * const tb[])
  34 {
  35         struct nft_immediate_expr *priv = nft_expr_priv(expr);
  36         struct nft_data_desc desc;
  37         int err;
  38
  39         if (tb[NFTA_IMMEDIATE_DREG] == NULL ||
  40             tb[NFTA_IMMEDIATE_DATA] == NULL)
  41                 return -EINVAL;
  42
  43         err = nft_data_init(ctx, &priv->data, sizeof(priv->data), &desc,
  44                             tb[NFTA_IMMEDIATE_DATA]);
  45         if (err < 0)
  46                 return err;
  47
  48         priv->dlen = desc.len;
  49
  50         priv->dreg = nft_parse_register(tb[NFTA_IMMEDIATE_DREG]);
  51         err = nft_validate_register_store(ctx, priv->dreg, &priv->data,
  52                                           desc.type, desc.len);
  53         if (err < 0)
  54                 goto err1;
  55
  56         return 0;
  57
  58 err1:
  59         nft_data_release(&priv->data, desc.type);
  60         return err;
  61 }
  62
  63 static void nft_immediate_activate(const struct nft_ctx *ctx,
  64                                    const struct nft_expr *expr)
  65 {
  66         const struct nft_immediate_expr *priv = nft_expr_priv(expr);
  67
  68         return nft_data_hold(&priv->data, nft_dreg_to_type(priv->dreg));
  69 }
  70
  71 static void nft_immediate_deactivate(const struct nft_ctx *ctx,
  72                                      const struct nft_expr *expr,
  73                                      enum nft_trans_phase phase)
  74 {
  75         const struct nft_immediate_expr *priv = nft_expr_priv(expr);
  76
  77         if (phase == NFT_TRANS_COMMIT)
  78                 return;
  79
  80         return nft_data_release(&priv->data, nft_dreg_to_type(priv->dreg));
  81 }
  82
  83 static int nft_immediate_dump(struct sk_buff *skb, const struct nft_expr *expr)
  84 {
  85         const struct nft_immediate_expr *priv = nft_expr_priv(expr);
  86
  87         if (nft_dump_register(skb, NFTA_IMMEDIATE_DREG, priv->dreg))
  88                 goto nla_put_failure;
  89
  90         return nft_data_dump(skb, NFTA_IMMEDIATE_DATA, &priv->data,
  91                              nft_dreg_to_type(priv->dreg), priv->dlen);
  92
  93 nla_put_failure:
  94         return -1;
  95 }
  96
  97 static int nft_immediate_validate(const struct nft_ctx *ctx,
  98                                   const struct nft_expr *expr,
  99                                   const struct nft_data **d)
 100 {
 101         const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 102         struct nft_ctx *pctx = (struct nft_ctx *)ctx;
 103         const struct nft_data *data;
 104         int err;
 105
 106         if (priv->dreg != NFT_REG_VERDICT)
 107                 return 0;
 108
 109         data = &priv->data;
 110
 111         switch (data->verdict.code) {
 112         case NFT_JUMP:
 113         case NFT_GOTO:
 114                 pctx->level++;
 115                 err = nft_chain_validate(ctx, data->verdict.chain);
 116                 if (err < 0)
 117                         return err;
 118                 pctx->level--;
 119                 break;
 120         default:
 121                 break;
 122         }
 123
 124         return 0;
 125 }
 126
 127 static const struct nft_expr_ops nft_imm_ops = {
 128         .type           = &nft_imm_type,
 129         .size           = NFT_EXPR_SIZE(sizeof(struct nft_immediate_expr)),
 130         .eval           = nft_immediate_eval,
 131         .init           = nft_immediate_init,
 132         .activate       = nft_immediate_activate,
 133         .deactivate     = nft_immediate_deactivate,
 134         .dump           = nft_immediate_dump,
 135         .validate       = nft_immediate_validate,
 136 };
 137
 138 struct nft_expr_type nft_imm_type __read_mostly = {
 139         .name           = "immediate",
 140         .ops            = &nft_imm_ops,
 141         .policy         = nft_immediate_policy,
 142         .maxattr        = NFTA_IMMEDIATE_MAX,
 143         .owner          = THIS_MODULE,
 144 };