nft_fib.c 3.9 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. *
  4. * Generic part shared by ipv4 and ipv6 backends.
  5. */
  6. #include <linux/kernel.h>
  7. #include <linux/init.h>
  8. #include <linux/module.h>
  9. #include <linux/netlink.h>
  10. #include <linux/netfilter.h>
  11. #include <linux/netfilter/nf_tables.h>
  12. #include <net/netfilter/nf_tables_core.h>
  13. #include <net/netfilter/nf_tables.h>
  14. #include <net/netfilter/nft_fib.h>
  15. const struct nla_policy nft_fib_policy[NFTA_FIB_MAX + 1] = {
  16. [NFTA_FIB_DREG] = { .type = NLA_U32 },
  17. [NFTA_FIB_RESULT] = { .type = NLA_U32 },
  18. [NFTA_FIB_FLAGS] = { .type = NLA_U32 },
  19. };
  20. EXPORT_SYMBOL(nft_fib_policy);
  21. #define NFTA_FIB_F_ALL (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR | \
  22. NFTA_FIB_F_MARK | NFTA_FIB_F_IIF | NFTA_FIB_F_OIF | \
  23. NFTA_FIB_F_PRESENT)
  24. int nft_fib_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
  25. const struct nft_data **data)
  26. {
  27. const struct nft_fib *priv = nft_expr_priv(expr);
  28. unsigned int hooks;
  29. switch (priv->result) {
  30. case NFT_FIB_RESULT_OIF:
  31. case NFT_FIB_RESULT_OIFNAME:
  32. hooks = (1 << NF_INET_PRE_ROUTING);
  33. break;
  34. case NFT_FIB_RESULT_ADDRTYPE:
  35. if (priv->flags & NFTA_FIB_F_IIF)
  36. hooks = (1 << NF_INET_PRE_ROUTING) |
  37. (1 << NF_INET_LOCAL_IN) |
  38. (1 << NF_INET_FORWARD);
  39. else if (priv->flags & NFTA_FIB_F_OIF)
  40. hooks = (1 << NF_INET_LOCAL_OUT) |
  41. (1 << NF_INET_POST_ROUTING) |
  42. (1 << NF_INET_FORWARD);
  43. else
  44. hooks = (1 << NF_INET_LOCAL_IN) |
  45. (1 << NF_INET_LOCAL_OUT) |
  46. (1 << NF_INET_FORWARD) |
  47. (1 << NF_INET_PRE_ROUTING) |
  48. (1 << NF_INET_POST_ROUTING);
  49. break;
  50. default:
  51. return -EINVAL;
  52. }
  53. return nft_chain_validate_hooks(ctx->chain, hooks);
  54. }
  55. EXPORT_SYMBOL_GPL(nft_fib_validate);
  56. int nft_fib_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
  57. const struct nlattr * const tb[])
  58. {
  59. struct nft_fib *priv = nft_expr_priv(expr);
  60. unsigned int len;
  61. int err;
  62. if (!tb[NFTA_FIB_DREG] || !tb[NFTA_FIB_RESULT] || !tb[NFTA_FIB_FLAGS])
  63. return -EINVAL;
  64. priv->flags = ntohl(nla_get_be32(tb[NFTA_FIB_FLAGS]));
  65. if (priv->flags == 0 || (priv->flags & ~NFTA_FIB_F_ALL))
  66. return -EINVAL;
  67. if ((priv->flags & (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) ==
  68. (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR))
  69. return -EINVAL;
  70. if ((priv->flags & (NFTA_FIB_F_IIF | NFTA_FIB_F_OIF)) ==
  71. (NFTA_FIB_F_IIF | NFTA_FIB_F_OIF))
  72. return -EINVAL;
  73. if ((priv->flags & (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) == 0)
  74. return -EINVAL;
  75. priv->result = ntohl(nla_get_be32(tb[NFTA_FIB_RESULT]));
  76. priv->dreg = nft_parse_register(tb[NFTA_FIB_DREG]);
  77. switch (priv->result) {
  78. case NFT_FIB_RESULT_OIF:
  79. if (priv->flags & NFTA_FIB_F_OIF)
  80. return -EINVAL;
  81. len = sizeof(int);
  82. break;
  83. case NFT_FIB_RESULT_OIFNAME:
  84. if (priv->flags & NFTA_FIB_F_OIF)
  85. return -EINVAL;
  86. len = IFNAMSIZ;
  87. break;
  88. case NFT_FIB_RESULT_ADDRTYPE:
  89. len = sizeof(u32);
  90. break;
  91. default:
  92. return -EINVAL;
  93. }
  94. err = nft_validate_register_store(ctx, priv->dreg, NULL,
  95. NFT_DATA_VALUE, len);
  96. if (err < 0)
  97. return err;
  98. return 0;
  99. }
  100. EXPORT_SYMBOL_GPL(nft_fib_init);
  101. int nft_fib_dump(struct sk_buff *skb, const struct nft_expr *expr)
  102. {
  103. const struct nft_fib *priv = nft_expr_priv(expr);
  104. if (nft_dump_register(skb, NFTA_FIB_DREG, priv->dreg))
  105. return -1;
  106. if (nla_put_be32(skb, NFTA_FIB_RESULT, htonl(priv->result)))
  107. return -1;
  108. if (nla_put_be32(skb, NFTA_FIB_FLAGS, htonl(priv->flags)))
  109. return -1;
  110. return 0;
  111. }
  112. EXPORT_SYMBOL_GPL(nft_fib_dump);
  113. void nft_fib_store_result(void *reg, const struct nft_fib *priv,
  114. const struct net_device *dev)
  115. {
  116. u32 *dreg = reg;
  117. int index;
  118. switch (priv->result) {
  119. case NFT_FIB_RESULT_OIF:
  120. index = dev ? dev->ifindex : 0;
  121. *dreg = (priv->flags & NFTA_FIB_F_PRESENT) ? !!index : index;
  122. break;
  123. case NFT_FIB_RESULT_OIFNAME:
  124. if (priv->flags & NFTA_FIB_F_PRESENT)
  125. *dreg = !!dev;
  126. else
  127. strncpy(reg, dev ? dev->name : "", IFNAMSIZ);
  128. break;
  129. default:
  130. WARN_ON_ONCE(1);
  131. *dreg = 0;
  132. break;
  133. }
  134. }
  135. EXPORT_SYMBOL_GPL(nft_fib_store_result);
  136. MODULE_LICENSE("GPL");
  137. MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");