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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 | // 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"); |