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 static void nf_do_netdev_egress(struct sk_buff *skb, struct net_device *dev, 17 enum nf_dev_hooks hook) 18 { 19 if (hook == NF_NETDEV_INGRESS && skb_mac_header_was_set(skb)) { 20 if (skb_cow_head(skb, skb->mac_len)) { 21 kfree_skb(skb); 22 return; 23 } 24 skb_push(skb, skb->mac_len); 25 } 26 27 skb->dev = dev; 28 skb_clear_tstamp(skb); 29 dev_queue_xmit(skb); 30 } 31 32 void nf_fwd_netdev_egress(const struct nft_pktinfo *pkt, int oif) 33 { 34 struct net_device *dev; 35 36 dev = dev_get_by_index_rcu(nft_net(pkt), oif); 37 if (!dev) { 38 kfree_skb(pkt->skb); 39 return; 40 } 41 42 nf_do_netdev_egress(pkt->skb, dev, nft_hook(pkt)); 43 } 44 EXPORT_SYMBOL_GPL(nf_fwd_netdev_egress); 45 46 void nf_dup_netdev_egress(const struct nft_pktinfo *pkt, int oif) 47 { 48 struct net_device *dev; 49 struct sk_buff *skb; 50 51 dev = dev_get_by_index_rcu(nft_net(pkt), oif); 52 if (dev == NULL) 53 return; 54 55 skb = skb_clone(pkt->skb, GFP_ATOMIC); 56 if (skb) 57 nf_do_netdev_egress(skb, dev, nft_hook(pkt)); 58 } 59 EXPORT_SYMBOL_GPL(nf_dup_netdev_egress); 60 61 int nft_fwd_dup_netdev_offload(struct nft_offload_ctx *ctx, 62 struct nft_flow_rule *flow, 63 enum flow_action_id id, int oif) 64 { 65 struct flow_action_entry *entry; 66 struct net_device *dev; 67 68 /* nft_flow_rule_destroy() releases the reference on this device. */ 69 dev = dev_get_by_index(ctx->net, oif); 70 if (!dev) 71 return -EOPNOTSUPP; 72 73 entry = &flow->rule->action.entries[ctx->num_actions++]; 74 entry->id = id; 75 entry->dev = dev; 76 77 return 0; 78 } 79 EXPORT_SYMBOL_GPL(nft_fwd_dup_netdev_offload); 80 81 MODULE_LICENSE("GPL"); 82 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); 83 MODULE_DESCRIPTION("Netfilter packet duplication support"); 84