| /* |
| * Filtering ARP tables module. |
| * |
| * Copyright (C) 2002 David S. Miller (davem@redhat.com) |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/netfilter_arp/arp_tables.h> |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("David S. Miller <davem@redhat.com>"); |
| MODULE_DESCRIPTION("arptables filter table"); |
| |
| #define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) | (1 << NF_ARP_OUT) | \ |
| (1 << NF_ARP_FORWARD)) |
| |
| /* Standard entry. */ |
| struct arpt_standard |
| { |
| struct arpt_entry entry; |
| struct arpt_standard_target target; |
| }; |
| |
| struct arpt_error_target |
| { |
| struct arpt_entry_target target; |
| char errorname[ARPT_FUNCTION_MAXNAMELEN]; |
| }; |
| |
| struct arpt_error |
| { |
| struct arpt_entry entry; |
| struct arpt_error_target target; |
| }; |
| |
| static struct |
| { |
| struct arpt_replace repl; |
| struct arpt_standard entries[3]; |
| struct arpt_error term; |
| } initial_table __initdata |
| = { { "filter", FILTER_VALID_HOOKS, 4, |
| sizeof(struct arpt_standard) * 3 + sizeof(struct arpt_error), |
| { [NF_ARP_IN] = 0, |
| [NF_ARP_OUT] = sizeof(struct arpt_standard), |
| [NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard), }, |
| { [NF_ARP_IN] = 0, |
| [NF_ARP_OUT] = sizeof(struct arpt_standard), |
| [NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard), }, |
| 0, NULL, { } }, |
| { |
| /* ARP_IN */ |
| { |
| { |
| { |
| { 0 }, { 0 }, { 0 }, { 0 }, |
| 0, 0, |
| { { 0, }, { 0, } }, |
| { { 0, }, { 0, } }, |
| 0, 0, |
| 0, 0, |
| 0, 0, |
| "", "", { 0 }, { 0 }, |
| 0, 0 |
| }, |
| sizeof(struct arpt_entry), |
| sizeof(struct arpt_standard), |
| 0, |
| { 0, 0 }, { } }, |
| { { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } }, |
| -NF_ACCEPT - 1 } |
| }, |
| /* ARP_OUT */ |
| { |
| { |
| { |
| { 0 }, { 0 }, { 0 }, { 0 }, |
| 0, 0, |
| { { 0, }, { 0, } }, |
| { { 0, }, { 0, } }, |
| 0, 0, |
| 0, 0, |
| 0, 0, |
| "", "", { 0 }, { 0 }, |
| 0, 0 |
| }, |
| sizeof(struct arpt_entry), |
| sizeof(struct arpt_standard), |
| 0, |
| { 0, 0 }, { } }, |
| { { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } }, |
| -NF_ACCEPT - 1 } |
| }, |
| /* ARP_FORWARD */ |
| { |
| { |
| { |
| { 0 }, { 0 }, { 0 }, { 0 }, |
| 0, 0, |
| { { 0, }, { 0, } }, |
| { { 0, }, { 0, } }, |
| 0, 0, |
| 0, 0, |
| 0, 0, |
| "", "", { 0 }, { 0 }, |
| 0, 0 |
| }, |
| sizeof(struct arpt_entry), |
| sizeof(struct arpt_standard), |
| 0, |
| { 0, 0 }, { } }, |
| { { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } }, |
| -NF_ACCEPT - 1 } |
| } |
| }, |
| /* ERROR */ |
| { |
| { |
| { |
| { 0 }, { 0 }, { 0 }, { 0 }, |
| 0, 0, |
| { { 0, }, { 0, } }, |
| { { 0, }, { 0, } }, |
| 0, 0, |
| 0, 0, |
| 0, 0, |
| "", "", { 0 }, { 0 }, |
| 0, 0 |
| }, |
| sizeof(struct arpt_entry), |
| sizeof(struct arpt_error), |
| 0, |
| { 0, 0 }, { } }, |
| { { { { ARPT_ALIGN(sizeof(struct arpt_error_target)), ARPT_ERROR_TARGET } }, |
| { } }, |
| "ERROR" |
| } |
| } |
| }; |
| |
| static struct arpt_table packet_filter = { |
| .name = "filter", |
| .valid_hooks = FILTER_VALID_HOOKS, |
| .lock = RW_LOCK_UNLOCKED, |
| .private = NULL, |
| .me = THIS_MODULE, |
| }; |
| |
| /* The work comes in here from netfilter.c */ |
| static unsigned int arpt_hook(unsigned int hook, |
| struct sk_buff **pskb, |
| const struct net_device *in, |
| const struct net_device *out, |
| int (*okfn)(struct sk_buff *)) |
| { |
| return arpt_do_table(pskb, hook, in, out, &packet_filter, NULL); |
| } |
| |
| static struct nf_hook_ops arpt_ops[] = { |
| { |
| .hook = arpt_hook, |
| .owner = THIS_MODULE, |
| .pf = NF_ARP, |
| .hooknum = NF_ARP_IN, |
| }, |
| { |
| .hook = arpt_hook, |
| .owner = THIS_MODULE, |
| .pf = NF_ARP, |
| .hooknum = NF_ARP_OUT, |
| }, |
| { |
| .hook = arpt_hook, |
| .owner = THIS_MODULE, |
| .pf = NF_ARP, |
| .hooknum = NF_ARP_FORWARD, |
| }, |
| }; |
| |
| static int __init init(void) |
| { |
| int ret, i; |
| |
| /* Register table */ |
| ret = arpt_register_table(&packet_filter, &initial_table.repl); |
| if (ret < 0) |
| return ret; |
| |
| for (i = 0; i < ARRAY_SIZE(arpt_ops); i++) |
| if ((ret = nf_register_hook(&arpt_ops[i])) < 0) |
| goto cleanup_hooks; |
| return ret; |
| |
| cleanup_hooks: |
| while (--i >= 0) |
| nf_unregister_hook(&arpt_ops[i]); |
| |
| arpt_unregister_table(&packet_filter); |
| return ret; |
| } |
| |
| static void __exit fini(void) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < ARRAY_SIZE(arpt_ops); i++) |
| nf_unregister_hook(&arpt_ops[i]); |
| |
| arpt_unregister_table(&packet_filter); |
| } |
| |
| module_init(init); |
| module_exit(fini); |