| /* |
| * ebtable_filter |
| * |
| * Authors: |
| * Bart De Schuymer <bdschuym@pandora.be> |
| * |
| * April, 2002 |
| * |
| */ |
| |
| #include <linux/netfilter_bridge/ebtables.h> |
| #include <linux/module.h> |
| |
| #define FILTER_VALID_HOOKS ((1 << NF_BR_LOCAL_IN) | (1 << NF_BR_FORWARD) | \ |
| (1 << NF_BR_LOCAL_OUT)) |
| |
| static struct ebt_entries initial_chains[] = |
| { |
| { |
| .name = "INPUT", |
| .policy = EBT_ACCEPT, |
| }, |
| { |
| .name = "FORWARD", |
| .policy = EBT_ACCEPT, |
| }, |
| { |
| .name = "OUTPUT", |
| .policy = EBT_ACCEPT, |
| }, |
| }; |
| |
| static struct ebt_replace_kernel initial_table = |
| { |
| .name = "filter", |
| .valid_hooks = FILTER_VALID_HOOKS, |
| .entries_size = 3 * sizeof(struct ebt_entries), |
| .hook_entry = { |
| [NF_BR_LOCAL_IN] = &initial_chains[0], |
| [NF_BR_FORWARD] = &initial_chains[1], |
| [NF_BR_LOCAL_OUT] = &initial_chains[2], |
| }, |
| .entries = (char *)initial_chains, |
| }; |
| |
| static int check(const struct ebt_table_info *info, unsigned int valid_hooks) |
| { |
| if (valid_hooks & ~FILTER_VALID_HOOKS) |
| return -EINVAL; |
| return 0; |
| } |
| |
| static struct ebt_table __frame_filter = |
| { |
| .name = "filter", |
| .table = &initial_table, |
| .valid_hooks = FILTER_VALID_HOOKS, |
| .lock = __RW_LOCK_UNLOCKED(__frame_filter.lock), |
| .check = check, |
| .me = THIS_MODULE, |
| }; |
| static struct ebt_table *frame_filter; |
| |
| static unsigned int |
| ebt_hook(unsigned int hook, struct sk_buff *skb, const struct net_device *in, |
| const struct net_device *out, int (*okfn)(struct sk_buff *)) |
| { |
| return ebt_do_table(hook, skb, in, out, frame_filter); |
| } |
| |
| static struct nf_hook_ops ebt_ops_filter[] __read_mostly = { |
| { |
| .hook = ebt_hook, |
| .owner = THIS_MODULE, |
| .pf = PF_BRIDGE, |
| .hooknum = NF_BR_LOCAL_IN, |
| .priority = NF_BR_PRI_FILTER_BRIDGED, |
| }, |
| { |
| .hook = ebt_hook, |
| .owner = THIS_MODULE, |
| .pf = PF_BRIDGE, |
| .hooknum = NF_BR_FORWARD, |
| .priority = NF_BR_PRI_FILTER_BRIDGED, |
| }, |
| { |
| .hook = ebt_hook, |
| .owner = THIS_MODULE, |
| .pf = PF_BRIDGE, |
| .hooknum = NF_BR_LOCAL_OUT, |
| .priority = NF_BR_PRI_FILTER_OTHER, |
| }, |
| }; |
| |
| static int __init ebtable_filter_init(void) |
| { |
| int ret; |
| |
| frame_filter = ebt_register_table(&init_net, &__frame_filter); |
| if (IS_ERR(frame_filter)) |
| return PTR_ERR(frame_filter); |
| ret = nf_register_hooks(ebt_ops_filter, ARRAY_SIZE(ebt_ops_filter)); |
| if (ret < 0) |
| ebt_unregister_table(frame_filter); |
| return ret; |
| } |
| |
| static void __exit ebtable_filter_fini(void) |
| { |
| nf_unregister_hooks(ebt_ops_filter, ARRAY_SIZE(ebt_ops_filter)); |
| ebt_unregister_table(frame_filter); |
| } |
| |
| module_init(ebtable_filter_init); |
| module_exit(ebtable_filter_fini); |
| MODULE_LICENSE("GPL"); |