/net/bridge/netfilter/ebtable_broute.c
http://github.com/mirrors/linux · C · 130 lines · 83 code · 21 blank · 26 comment · 8 complexity · d554af6943085529201f6bd0133fd041 MD5 · raw file
- // 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 int check(const struct ebt_table_info *info, unsigned int valid_hooks)
- {
- if (valid_hooks & ~(1 << NF_BR_BROUTING))
- return -EINVAL;
- return 0;
- }
- static const struct ebt_table broute_table = {
- .name = "broute",
- .table = &initial_table,
- .valid_hooks = 1 << NF_BR_BROUTING,
- .check = check,
- .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(skb, &state, state.net->xt.broute_table);
- 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 __net_init broute_net_init(struct net *net)
- {
- return ebt_register_table(net, &broute_table, &ebt_ops_broute,
- &net->xt.broute_table);
- }
- static void __net_exit broute_net_exit(struct net *net)
- {
- ebt_unregister_table(net, net->xt.broute_table, &ebt_ops_broute);
- }
- static struct pernet_operations broute_net_ops = {
- .init = broute_net_init,
- .exit = broute_net_exit,
- };
- static int __init ebtable_broute_init(void)
- {
- return register_pernet_subsys(&broute_net_ops);
- }
- static void __exit ebtable_broute_fini(void)
- {
- unregister_pernet_subsys(&broute_net_ops);
- }
- module_init(ebtable_broute_init);
- module_exit(ebtable_broute_fini);
- MODULE_LICENSE("GPL");