net/netfilter/nf_dup_netdev.c

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