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/nf_tables_offload.h> 14 #include <net/netfilter/nf_dup_netdev.h> 15 16 struct nft_dup_netdev { 17 u8 sreg_dev; 18 }; 19 20 static void nft_dup_netdev_eval(const struct nft_expr *expr, 21 struct nft_regs *regs, 22 const struct nft_pktinfo *pkt) 23 { 24 struct nft_dup_netdev *priv = nft_expr_priv(expr); 25 int oif = regs->data[priv->sreg_dev]; 26 27 nf_dup_netdev_egress(pkt, oif); 28 } 29 30 static const struct nla_policy nft_dup_netdev_policy[NFTA_DUP_MAX + 1] = { 31 [NFTA_DUP_SREG_DEV] = { .type = NLA_U32 }, 32 }; 33 34 static int nft_dup_netdev_init(const struct nft_ctx *ctx, 35 const struct nft_expr *expr, 36 const struct nlattr * const tb[]) 37 { 38 struct nft_dup_netdev *priv = nft_expr_priv(expr); 39 40 if (tb[NFTA_DUP_SREG_DEV] == NULL) 41 return -EINVAL; 42 43 return nft_parse_register_load(tb[NFTA_DUP_SREG_DEV], &priv->sreg_dev, 44 sizeof(int)); 45 } 46 47 static int nft_dup_netdev_dump(struct sk_buff *skb, 48 const struct nft_expr *expr, bool reset) 49 { 50 struct nft_dup_netdev *priv = nft_expr_priv(expr); 51 52 if (nft_dump_register(skb, NFTA_DUP_SREG_DEV, priv->sreg_dev)) 53 goto nla_put_failure; 54 55 return 0; 56 57 nla_put_failure: 58 return -1; 59 } 60 61 static int nft_dup_netdev_offload(struct nft_offload_ctx *ctx, 62 struct nft_flow_rule *flow, 63 const struct nft_expr *expr) 64 { 65 const struct nft_dup_netdev *priv = nft_expr_priv(expr); 66 int oif = ctx->regs[priv->sreg_dev].data.data[0]; 67 68 return nft_fwd_dup_netdev_offload(ctx, flow, FLOW_ACTION_MIRRED, oif); 69 } 70 71 static bool nft_dup_netdev_offload_action(const struct nft_expr *expr) 72 { 73 return true; 74 } 75 76 static struct nft_expr_type nft_dup_netdev_type; 77 static const struct nft_expr_ops nft_dup_netdev_ops = { 78 .type = &nft_dup_netdev_type, 79 .size = NFT_EXPR_SIZE(sizeof(struct nft_dup_netdev)), 80 .eval = nft_dup_netdev_eval, 81 .init = nft_dup_netdev_init, 82 .dump = nft_dup_netdev_dump, 83 .reduce = NFT_REDUCE_READONLY, 84 .offload = nft_dup_netdev_offload, 85 .offload_action = nft_dup_netdev_offload_action, 86 }; 87 88 static struct nft_expr_type nft_dup_netdev_type __read_mostly = { 89 .family = NFPROTO_NETDEV, 90 .name = "dup", 91 .ops = &nft_dup_netdev_ops, 92 .policy = nft_dup_netdev_policy, 93 .maxattr = NFTA_DUP_MAX, 94 .owner = THIS_MODULE, 95 }; 96 97 static int __init nft_dup_netdev_module_init(void) 98 { 99 return nft_register_expr(&nft_dup_netdev_type); 100 } 101 102 static void __exit nft_dup_netdev_module_exit(void) 103 { 104 nft_unregister_expr(&nft_dup_netdev_type); 105 } 106 107 module_init(nft_dup_netdev_module_init); 108 module_exit(nft_dup_netdev_module_exit); 109 110 MODULE_LICENSE("GPL"); 111 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); 112 MODULE_ALIAS_NFT_AF_EXPR(5, "dup"); 113 MODULE_DESCRIPTION("nftables netdev packet duplication support"); 114