nft_dup_netdev.c 2.9 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
  4. */
  5. #include <linux/kernel.h>
  6. #include <linux/init.h>
  7. #include <linux/module.h>
  8. #include <linux/netlink.h>
  9. #include <linux/netfilter.h>
  10. #include <linux/netfilter/nf_tables.h>
  11. #include <net/netfilter/nf_tables.h>
  12. #include <net/netfilter/nf_tables_offload.h>
  13. #include <net/netfilter/nf_dup_netdev.h>
  14. struct nft_dup_netdev {
  15. enum nft_registers sreg_dev:8;
  16. };
  17. static void nft_dup_netdev_eval(const struct nft_expr *expr,
  18. struct nft_regs *regs,
  19. const struct nft_pktinfo *pkt)
  20. {
  21. struct nft_dup_netdev *priv = nft_expr_priv(expr);
  22. int oif = regs->data[priv->sreg_dev];
  23. nf_dup_netdev_egress(pkt, oif);
  24. }
  25. static const struct nla_policy nft_dup_netdev_policy[NFTA_DUP_MAX + 1] = {
  26. [NFTA_DUP_SREG_DEV] = { .type = NLA_U32 },
  27. };
  28. static int nft_dup_netdev_init(const struct nft_ctx *ctx,
  29. const struct nft_expr *expr,
  30. const struct nlattr * const tb[])
  31. {
  32. struct nft_dup_netdev *priv = nft_expr_priv(expr);
  33. if (tb[NFTA_DUP_SREG_DEV] == NULL)
  34. return -EINVAL;
  35. priv->sreg_dev = nft_parse_register(tb[NFTA_DUP_SREG_DEV]);
  36. return nft_validate_register_load(priv->sreg_dev, sizeof(int));
  37. }
  38. static int nft_dup_netdev_dump(struct sk_buff *skb, const struct nft_expr *expr)
  39. {
  40. struct nft_dup_netdev *priv = nft_expr_priv(expr);
  41. if (nft_dump_register(skb, NFTA_DUP_SREG_DEV, priv->sreg_dev))
  42. goto nla_put_failure;
  43. return 0;
  44. nla_put_failure:
  45. return -1;
  46. }
  47. static int nft_dup_netdev_offload(struct nft_offload_ctx *ctx,
  48. struct nft_flow_rule *flow,
  49. const struct nft_expr *expr)
  50. {
  51. const struct nft_dup_netdev *priv = nft_expr_priv(expr);
  52. int oif = ctx->regs[priv->sreg_dev].data.data[0];
  53. return nft_fwd_dup_netdev_offload(ctx, flow, FLOW_ACTION_MIRRED, oif);
  54. }
  55. static bool nft_dup_netdev_offload_action(const struct nft_expr *expr)
  56. {
  57. return true;
  58. }
  59. static struct nft_expr_type nft_dup_netdev_type;
  60. static const struct nft_expr_ops nft_dup_netdev_ops = {
  61. .type = &nft_dup_netdev_type,
  62. .size = NFT_EXPR_SIZE(sizeof(struct nft_dup_netdev)),
  63. .eval = nft_dup_netdev_eval,
  64. .init = nft_dup_netdev_init,
  65. .dump = nft_dup_netdev_dump,
  66. .offload = nft_dup_netdev_offload,
  67. .offload_action = nft_dup_netdev_offload_action,
  68. };
  69. static struct nft_expr_type nft_dup_netdev_type __read_mostly = {
  70. .family = NFPROTO_NETDEV,
  71. .name = "dup",
  72. .ops = &nft_dup_netdev_ops,
  73. .policy = nft_dup_netdev_policy,
  74. .maxattr = NFTA_DUP_MAX,
  75. .owner = THIS_MODULE,
  76. };
  77. static int __init nft_dup_netdev_module_init(void)
  78. {
  79. return nft_register_expr(&nft_dup_netdev_type);
  80. }
  81. static void __exit nft_dup_netdev_module_exit(void)
  82. {
  83. nft_unregister_expr(&nft_dup_netdev_type);
  84. }
  85. module_init(nft_dup_netdev_module_init);
  86. module_exit(nft_dup_netdev_module_exit);
  87. MODULE_LICENSE("GPL");
  88. MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
  89. MODULE_ALIAS_NFT_AF_EXPR(5, "dup");
  90. MODULE_DESCRIPTION("nftables netdev packet duplication support");