| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * ebtable_broute |
| * |
| * Authors: |
| * Bart De Schuymer <bdschuym@pandora.be> |
| * |
| * April, 2002 |
| * |
| * This table lets you choose between routing and bridging for frames |
| * entering on a bridge enslaved nic. This table is traversed before any |
| * other ebtables table. See net/bridge/br_input.c. |
| */ |
| |
| #include <linux/netfilter_bridge/ebtables.h> |
| #include <linux/module.h> |
| #include <linux/if_bridge.h> |
| |
| #include "../br_private.h" |
| |
| /* EBT_ACCEPT means the frame will be bridged |
| * EBT_DROP means the frame will be routed |
| */ |
| static struct ebt_entries initial_chain = { |
| .name = "BROUTING", |
| .policy = EBT_ACCEPT, |
| }; |
| |
| static struct ebt_replace_kernel initial_table = { |
| .name = "broute", |
| .valid_hooks = 1 << NF_BR_BROUTING, |
| .entries_size = sizeof(struct ebt_entries), |
| .hook_entry = { |
| [NF_BR_BROUTING] = &initial_chain, |
| }, |
| .entries = (char *)&initial_chain, |
| }; |
| |
| static const struct ebt_table broute_table = { |
| .name = "broute", |
| .table = &initial_table, |
| .valid_hooks = 1 << NF_BR_BROUTING, |
| .me = THIS_MODULE, |
| }; |
| |
| static unsigned int ebt_broute(void *priv, struct sk_buff *skb, |
| const struct nf_hook_state *s) |
| { |
| struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
| struct nf_hook_state state; |
| unsigned char *dest; |
| int ret; |
| |
| if (!p || p->state != BR_STATE_FORWARDING) |
| return NF_ACCEPT; |
| |
| nf_hook_state_init(&state, NF_BR_BROUTING, |
| NFPROTO_BRIDGE, s->in, NULL, NULL, |
| s->net, NULL); |
| |
| ret = ebt_do_table(priv, skb, &state); |
| if (ret != NF_DROP) |
| return ret; |
| |
| /* DROP in ebtables -t broute means that the |
| * skb should be routed, not bridged. |
| * This is awkward, but can't be changed for compatibility |
| * reasons. |
| * |
| * We map DROP to ACCEPT and set the ->br_netfilter_broute flag. |
| */ |
| BR_INPUT_SKB_CB(skb)->br_netfilter_broute = 1; |
| |
| /* undo PACKET_HOST mangling done in br_input in case the dst |
| * address matches the logical bridge but not the port. |
| */ |
| dest = eth_hdr(skb)->h_dest; |
| if (skb->pkt_type == PACKET_HOST && |
| !ether_addr_equal(skb->dev->dev_addr, dest) && |
| ether_addr_equal(p->br->dev->dev_addr, dest)) |
| skb->pkt_type = PACKET_OTHERHOST; |
| |
| return NF_ACCEPT; |
| } |
| |
| static const struct nf_hook_ops ebt_ops_broute = { |
| .hook = ebt_broute, |
| .pf = NFPROTO_BRIDGE, |
| .hooknum = NF_BR_PRE_ROUTING, |
| .priority = NF_BR_PRI_FIRST, |
| }; |
| |
| static int broute_table_init(struct net *net) |
| { |
| return ebt_register_table(net, &broute_table, &ebt_ops_broute); |
| } |
| |
| static void __net_exit broute_net_pre_exit(struct net *net) |
| { |
| ebt_unregister_table_pre_exit(net, "broute"); |
| } |
| |
| static void __net_exit broute_net_exit(struct net *net) |
| { |
| ebt_unregister_table(net, "broute"); |
| } |
| |
| static struct pernet_operations broute_net_ops = { |
| .exit = broute_net_exit, |
| .pre_exit = broute_net_pre_exit, |
| }; |
| |
| static int __init ebtable_broute_init(void) |
| { |
| int ret = ebt_register_template(&broute_table, broute_table_init); |
| |
| if (ret) |
| return ret; |
| |
| ret = register_pernet_subsys(&broute_net_ops); |
| if (ret) { |
| ebt_unregister_template(&broute_table); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static void __exit ebtable_broute_fini(void) |
| { |
| unregister_pernet_subsys(&broute_net_ops); |
| ebt_unregister_template(&broute_table); |
| } |
| |
| module_init(ebtable_broute_init); |
| module_exit(ebtable_broute_fini); |
| MODULE_LICENSE("GPL"); |
| MODULE_DESCRIPTION("Force packets to be routed instead of bridged"); |