1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * ebtable_filter 4 * 5 * Authors: 6 * Bart De Schuymer <bdschuym@pandora.be> 7 * 8 * April, 2002 9 * 10 */ 11 12 #include <linux/netfilter_bridge/ebtables.h> 13 #include <uapi/linux/netfilter_bridge.h> 14 #include <linux/module.h> 15 16 #define FILTER_VALID_HOOKS ((1 << NF_BR_LOCAL_IN) | (1 << NF_BR_FORWARD) | \ 17 (1 << NF_BR_LOCAL_OUT)) 18 19 static struct ebt_entries initial_chains[] = { 20 { 21 .name = "INPUT", 22 .policy = EBT_ACCEPT, 23 }, 24 { 25 .name = "FORWARD", 26 .policy = EBT_ACCEPT, 27 }, 28 { 29 .name = "OUTPUT", 30 .policy = EBT_ACCEPT, 31 }, 32 }; 33 34 static struct ebt_replace_kernel initial_table = { 35 .name = "filter", 36 .valid_hooks = FILTER_VALID_HOOKS, 37 .entries_size = 3 * sizeof(struct ebt_entries), 38 .hook_entry = { 39 [NF_BR_LOCAL_IN] = &initial_chains[0], 40 [NF_BR_FORWARD] = &initial_chains[1], 41 [NF_BR_LOCAL_OUT] = &initial_chains[2], 42 }, 43 .entries = (char *)initial_chains, 44 }; 45 46 static const struct ebt_table frame_filter = { 47 .name = "filter", 48 .table = &initial_table, 49 .valid_hooks = FILTER_VALID_HOOKS, 50 .me = THIS_MODULE, 51 }; 52 53 static const struct nf_hook_ops ebt_ops_filter[] = { 54 { 55 .hook = ebt_do_table, 56 .pf = NFPROTO_BRIDGE, 57 .hooknum = NF_BR_LOCAL_IN, 58 .priority = NF_BR_PRI_FILTER_BRIDGED, 59 }, 60 { 61 .hook = ebt_do_table, 62 .pf = NFPROTO_BRIDGE, 63 .hooknum = NF_BR_FORWARD, 64 .priority = NF_BR_PRI_FILTER_BRIDGED, 65 }, 66 { 67 .hook = ebt_do_table, 68 .pf = NFPROTO_BRIDGE, 69 .hooknum = NF_BR_LOCAL_OUT, 70 .priority = NF_BR_PRI_FILTER_OTHER, 71 }, 72 }; 73 74 static int frame_filter_table_init(struct net *net) 75 { 76 return ebt_register_table(net, &frame_filter, ebt_ops_filter); 77 } 78 79 static void __net_exit frame_filter_net_pre_exit(struct net *net) 80 { 81 ebt_unregister_table_pre_exit(net, "filter"); 82 } 83 84 static void __net_exit frame_filter_net_exit(struct net *net) 85 { 86 ebt_unregister_table(net, "filter"); 87 } 88 89 static struct pernet_operations frame_filter_net_ops = { 90 .exit = frame_filter_net_exit, 91 .pre_exit = frame_filter_net_pre_exit, 92 }; 93 94 static int __init ebtable_filter_init(void) 95 { 96 int ret = ebt_register_template(&frame_filter, frame_filter_table_init); 97 98 if (ret) 99 return ret; 100 101 ret = register_pernet_subsys(&frame_filter_net_ops); 102 if (ret) { 103 ebt_unregister_template(&frame_filter); 104 return ret; 105 } 106 107 return 0; 108 } 109 110 static void __exit ebtable_filter_fini(void) 111 { 112 unregister_pernet_subsys(&frame_filter_net_ops); 113 ebt_unregister_template(&frame_filter); 114 } 115 116 module_init(ebtable_filter_init); 117 module_exit(ebtable_filter_fini); 118 MODULE_LICENSE("GPL"); 119