1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org> 4 */ 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.h> 13 #include <net/netfilter/ipv4/nf_dup_ipv4.h> 14 15 struct nft_dup_ipv4 { 16 u8 sreg_addr; 17 u8 sreg_dev; 18 }; 19 20 static void nft_dup_ipv4_eval(const struct nft_expr *expr, 21 struct nft_regs *regs, 22 const struct nft_pktinfo *pkt) 23 { 24 struct nft_dup_ipv4 *priv = nft_expr_priv(expr); 25 struct in_addr gw = { 26 .s_addr = (__force __be32)regs->data[priv->sreg_addr], 27 }; 28 int oif = priv->sreg_dev ? regs->data[priv->sreg_dev] : -1; 29 30 nf_dup_ipv4(nft_net(pkt), pkt->skb, nft_hook(pkt), &gw, oif); 31 } 32 33 static int nft_dup_ipv4_init(const struct nft_ctx *ctx, 34 const struct nft_expr *expr, 35 const struct nlattr * const tb[]) 36 { 37 struct nft_dup_ipv4 *priv = nft_expr_priv(expr); 38 int err; 39 40 if (tb[NFTA_DUP_SREG_ADDR] == NULL) 41 return -EINVAL; 42 43 err = nft_parse_register_load(tb[NFTA_DUP_SREG_ADDR], &priv->sreg_addr, 44 sizeof(struct in_addr)); 45 if (err < 0) 46 return err; 47 48 if (tb[NFTA_DUP_SREG_DEV]) 49 err = nft_parse_register_load(tb[NFTA_DUP_SREG_DEV], 50 &priv->sreg_dev, sizeof(int)); 51 52 return err; 53 } 54 55 static int nft_dup_ipv4_dump(struct sk_buff *skb, const struct nft_expr *expr) 56 { 57 struct nft_dup_ipv4 *priv = nft_expr_priv(expr); 58 59 if (nft_dump_register(skb, NFTA_DUP_SREG_ADDR, priv->sreg_addr)) 60 goto nla_put_failure; 61 if (priv->sreg_dev && 62 nft_dump_register(skb, NFTA_DUP_SREG_DEV, priv->sreg_dev)) 63 goto nla_put_failure; 64 65 return 0; 66 67 nla_put_failure: 68 return -1; 69 } 70 71 static struct nft_expr_type nft_dup_ipv4_type; 72 static const struct nft_expr_ops nft_dup_ipv4_ops = { 73 .type = &nft_dup_ipv4_type, 74 .size = NFT_EXPR_SIZE(sizeof(struct nft_dup_ipv4)), 75 .eval = nft_dup_ipv4_eval, 76 .init = nft_dup_ipv4_init, 77 .dump = nft_dup_ipv4_dump, 78 }; 79 80 static const struct nla_policy nft_dup_ipv4_policy[NFTA_DUP_MAX + 1] = { 81 [NFTA_DUP_SREG_ADDR] = { .type = NLA_U32 }, 82 [NFTA_DUP_SREG_DEV] = { .type = NLA_U32 }, 83 }; 84 85 static struct nft_expr_type nft_dup_ipv4_type __read_mostly = { 86 .family = NFPROTO_IPV4, 87 .name = "dup", 88 .ops = &nft_dup_ipv4_ops, 89 .policy = nft_dup_ipv4_policy, 90 .maxattr = NFTA_DUP_MAX, 91 .owner = THIS_MODULE, 92 }; 93 94 static int __init nft_dup_ipv4_module_init(void) 95 { 96 return nft_register_expr(&nft_dup_ipv4_type); 97 } 98 99 static void __exit nft_dup_ipv4_module_exit(void) 100 { 101 nft_unregister_expr(&nft_dup_ipv4_type); 102 } 103 104 module_init(nft_dup_ipv4_module_init); 105 module_exit(nft_dup_ipv4_module_exit); 106 107 MODULE_LICENSE("GPL"); 108 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); 109 MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "dup"); 110 MODULE_DESCRIPTION("IPv4 nftables packet duplication support"); 111