Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Filtering ARP tables module. |
| 3 | * |
| 4 | * Copyright (C) 2002 David S. Miller (davem@redhat.com) |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include <linux/module.h> |
| 9 | #include <linux/netfilter_arp/arp_tables.h> |
| 10 | |
| 11 | MODULE_LICENSE("GPL"); |
| 12 | MODULE_AUTHOR("David S. Miller <davem@redhat.com>"); |
| 13 | MODULE_DESCRIPTION("arptables filter table"); |
| 14 | |
| 15 | #define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) | (1 << NF_ARP_OUT) | \ |
| 16 | (1 << NF_ARP_FORWARD)) |
| 17 | |
| 18 | /* Standard entry. */ |
| 19 | struct arpt_standard |
| 20 | { |
| 21 | struct arpt_entry entry; |
| 22 | struct arpt_standard_target target; |
| 23 | }; |
| 24 | |
| 25 | struct arpt_error_target |
| 26 | { |
| 27 | struct arpt_entry_target target; |
| 28 | char errorname[ARPT_FUNCTION_MAXNAMELEN]; |
| 29 | }; |
| 30 | |
| 31 | struct arpt_error |
| 32 | { |
| 33 | struct arpt_entry entry; |
| 34 | struct arpt_error_target target; |
| 35 | }; |
| 36 | |
| 37 | static struct |
| 38 | { |
| 39 | struct arpt_replace repl; |
| 40 | struct arpt_standard entries[3]; |
| 41 | struct arpt_error term; |
| 42 | } initial_table __initdata |
| 43 | = { { "filter", FILTER_VALID_HOOKS, 4, |
| 44 | sizeof(struct arpt_standard) * 3 + sizeof(struct arpt_error), |
| 45 | { [NF_ARP_IN] = 0, |
| 46 | [NF_ARP_OUT] = sizeof(struct arpt_standard), |
| 47 | [NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard), }, |
| 48 | { [NF_ARP_IN] = 0, |
| 49 | [NF_ARP_OUT] = sizeof(struct arpt_standard), |
| 50 | [NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard), }, |
| 51 | 0, NULL, { } }, |
| 52 | { |
| 53 | /* ARP_IN */ |
| 54 | { |
| 55 | { |
| 56 | { |
| 57 | { 0 }, { 0 }, { 0 }, { 0 }, |
| 58 | 0, 0, |
| 59 | { { 0, }, { 0, } }, |
| 60 | { { 0, }, { 0, } }, |
| 61 | 0, 0, |
| 62 | 0, 0, |
| 63 | 0, 0, |
| 64 | "", "", { 0 }, { 0 }, |
| 65 | 0, 0 |
| 66 | }, |
| 67 | sizeof(struct arpt_entry), |
| 68 | sizeof(struct arpt_standard), |
| 69 | 0, |
| 70 | { 0, 0 }, { } }, |
| 71 | { { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } }, |
| 72 | -NF_ACCEPT - 1 } |
| 73 | }, |
| 74 | /* ARP_OUT */ |
| 75 | { |
| 76 | { |
| 77 | { |
| 78 | { 0 }, { 0 }, { 0 }, { 0 }, |
| 79 | 0, 0, |
| 80 | { { 0, }, { 0, } }, |
| 81 | { { 0, }, { 0, } }, |
| 82 | 0, 0, |
| 83 | 0, 0, |
| 84 | 0, 0, |
| 85 | "", "", { 0 }, { 0 }, |
| 86 | 0, 0 |
| 87 | }, |
| 88 | sizeof(struct arpt_entry), |
| 89 | sizeof(struct arpt_standard), |
| 90 | 0, |
| 91 | { 0, 0 }, { } }, |
| 92 | { { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } }, |
| 93 | -NF_ACCEPT - 1 } |
| 94 | }, |
| 95 | /* ARP_FORWARD */ |
| 96 | { |
| 97 | { |
| 98 | { |
| 99 | { 0 }, { 0 }, { 0 }, { 0 }, |
| 100 | 0, 0, |
| 101 | { { 0, }, { 0, } }, |
| 102 | { { 0, }, { 0, } }, |
| 103 | 0, 0, |
| 104 | 0, 0, |
| 105 | 0, 0, |
| 106 | "", "", { 0 }, { 0 }, |
| 107 | 0, 0 |
| 108 | }, |
| 109 | sizeof(struct arpt_entry), |
| 110 | sizeof(struct arpt_standard), |
| 111 | 0, |
| 112 | { 0, 0 }, { } }, |
| 113 | { { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } }, |
| 114 | -NF_ACCEPT - 1 } |
| 115 | } |
| 116 | }, |
| 117 | /* ERROR */ |
| 118 | { |
| 119 | { |
| 120 | { |
| 121 | { 0 }, { 0 }, { 0 }, { 0 }, |
| 122 | 0, 0, |
| 123 | { { 0, }, { 0, } }, |
| 124 | { { 0, }, { 0, } }, |
| 125 | 0, 0, |
| 126 | 0, 0, |
| 127 | 0, 0, |
| 128 | "", "", { 0 }, { 0 }, |
| 129 | 0, 0 |
| 130 | }, |
| 131 | sizeof(struct arpt_entry), |
| 132 | sizeof(struct arpt_error), |
| 133 | 0, |
| 134 | { 0, 0 }, { } }, |
| 135 | { { { { ARPT_ALIGN(sizeof(struct arpt_error_target)), ARPT_ERROR_TARGET } }, |
| 136 | { } }, |
| 137 | "ERROR" |
| 138 | } |
| 139 | } |
| 140 | }; |
| 141 | |
| 142 | static struct arpt_table packet_filter = { |
| 143 | .name = "filter", |
| 144 | .valid_hooks = FILTER_VALID_HOOKS, |
| 145 | .lock = RW_LOCK_UNLOCKED, |
| 146 | .private = NULL, |
| 147 | .me = THIS_MODULE, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 148 | .af = NF_ARP, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | }; |
| 150 | |
| 151 | /* The work comes in here from netfilter.c */ |
| 152 | static unsigned int arpt_hook(unsigned int hook, |
| 153 | struct sk_buff **pskb, |
| 154 | const struct net_device *in, |
| 155 | const struct net_device *out, |
| 156 | int (*okfn)(struct sk_buff *)) |
| 157 | { |
| 158 | return arpt_do_table(pskb, hook, in, out, &packet_filter, NULL); |
| 159 | } |
| 160 | |
| 161 | static struct nf_hook_ops arpt_ops[] = { |
| 162 | { |
| 163 | .hook = arpt_hook, |
| 164 | .owner = THIS_MODULE, |
| 165 | .pf = NF_ARP, |
| 166 | .hooknum = NF_ARP_IN, |
| 167 | }, |
| 168 | { |
| 169 | .hook = arpt_hook, |
| 170 | .owner = THIS_MODULE, |
| 171 | .pf = NF_ARP, |
| 172 | .hooknum = NF_ARP_OUT, |
| 173 | }, |
| 174 | { |
| 175 | .hook = arpt_hook, |
| 176 | .owner = THIS_MODULE, |
| 177 | .pf = NF_ARP, |
| 178 | .hooknum = NF_ARP_FORWARD, |
| 179 | }, |
| 180 | }; |
| 181 | |
| 182 | static int __init init(void) |
| 183 | { |
| 184 | int ret, i; |
| 185 | |
| 186 | /* Register table */ |
| 187 | ret = arpt_register_table(&packet_filter, &initial_table.repl); |
| 188 | if (ret < 0) |
| 189 | return ret; |
| 190 | |
| 191 | for (i = 0; i < ARRAY_SIZE(arpt_ops); i++) |
| 192 | if ((ret = nf_register_hook(&arpt_ops[i])) < 0) |
| 193 | goto cleanup_hooks; |
| 194 | return ret; |
| 195 | |
| 196 | cleanup_hooks: |
| 197 | while (--i >= 0) |
| 198 | nf_unregister_hook(&arpt_ops[i]); |
| 199 | |
| 200 | arpt_unregister_table(&packet_filter); |
| 201 | return ret; |
| 202 | } |
| 203 | |
| 204 | static void __exit fini(void) |
| 205 | { |
| 206 | unsigned int i; |
| 207 | |
| 208 | for (i = 0; i < ARRAY_SIZE(arpt_ops); i++) |
| 209 | nf_unregister_hook(&arpt_ops[i]); |
| 210 | |
| 211 | arpt_unregister_table(&packet_filter); |
| 212 | } |
| 213 | |
| 214 | module_init(init); |
| 215 | module_exit(fini); |