Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * IPv6 packet mangling table, a port of the IPv4 mangle table to IPv6 |
| 3 | * |
| 4 | * Copyright (C) 2000-2001 by Harald Welte <laforge@gnumonks.org> |
| 5 | * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | * |
| 11 | * Extended to all five netfilter hooks by Brad Chapman & Harald Welte |
| 12 | */ |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/netfilter_ipv6/ip6_tables.h> |
| 15 | |
| 16 | MODULE_LICENSE("GPL"); |
| 17 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); |
| 18 | MODULE_DESCRIPTION("ip6tables mangle table"); |
| 19 | |
| 20 | #define MANGLE_VALID_HOOKS ((1 << NF_IP6_PRE_ROUTING) | \ |
| 21 | (1 << NF_IP6_LOCAL_IN) | \ |
| 22 | (1 << NF_IP6_FORWARD) | \ |
| 23 | (1 << NF_IP6_LOCAL_OUT) | \ |
| 24 | (1 << NF_IP6_POST_ROUTING)) |
| 25 | |
| 26 | #if 0 |
| 27 | #define DEBUGP(x, args...) printk(KERN_DEBUG x, ## args) |
| 28 | #else |
| 29 | #define DEBUGP(x, args...) |
| 30 | #endif |
| 31 | |
| 32 | /* Standard entry. */ |
| 33 | struct ip6t_standard |
| 34 | { |
| 35 | struct ip6t_entry entry; |
| 36 | struct ip6t_standard_target target; |
| 37 | }; |
| 38 | |
| 39 | struct ip6t_error_target |
| 40 | { |
| 41 | struct ip6t_entry_target target; |
| 42 | char errorname[IP6T_FUNCTION_MAXNAMELEN]; |
| 43 | }; |
| 44 | |
| 45 | struct ip6t_error |
| 46 | { |
| 47 | struct ip6t_entry entry; |
| 48 | struct ip6t_error_target target; |
| 49 | }; |
| 50 | |
| 51 | static struct |
| 52 | { |
| 53 | struct ip6t_replace repl; |
| 54 | struct ip6t_standard entries[5]; |
| 55 | struct ip6t_error term; |
| 56 | } initial_table __initdata |
| 57 | = { { "mangle", MANGLE_VALID_HOOKS, 6, |
| 58 | sizeof(struct ip6t_standard) * 5 + sizeof(struct ip6t_error), |
| 59 | { [NF_IP6_PRE_ROUTING] = 0, |
| 60 | [NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard), |
| 61 | [NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2, |
| 62 | [NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3, |
| 63 | [NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4}, |
| 64 | { [NF_IP6_PRE_ROUTING] = 0, |
| 65 | [NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard), |
| 66 | [NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2, |
| 67 | [NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3, |
| 68 | [NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4}, |
| 69 | 0, NULL, { } }, |
| 70 | { |
| 71 | /* PRE_ROUTING */ |
| 72 | { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 }, |
| 73 | 0, |
| 74 | sizeof(struct ip6t_entry), |
| 75 | sizeof(struct ip6t_standard), |
| 76 | 0, { 0, 0 }, { } }, |
| 77 | { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } }, |
| 78 | -NF_ACCEPT - 1 } }, |
| 79 | /* LOCAL_IN */ |
| 80 | { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 }, |
| 81 | 0, |
| 82 | sizeof(struct ip6t_entry), |
| 83 | sizeof(struct ip6t_standard), |
| 84 | 0, { 0, 0 }, { } }, |
| 85 | { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } }, |
| 86 | -NF_ACCEPT - 1 } }, |
| 87 | /* FORWARD */ |
| 88 | { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 }, |
| 89 | 0, |
| 90 | sizeof(struct ip6t_entry), |
| 91 | sizeof(struct ip6t_standard), |
| 92 | 0, { 0, 0 }, { } }, |
| 93 | { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } }, |
| 94 | -NF_ACCEPT - 1 } }, |
| 95 | /* LOCAL_OUT */ |
| 96 | { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 }, |
| 97 | 0, |
| 98 | sizeof(struct ip6t_entry), |
| 99 | sizeof(struct ip6t_standard), |
| 100 | 0, { 0, 0 }, { } }, |
| 101 | { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } }, |
| 102 | -NF_ACCEPT - 1 } }, |
| 103 | /* POST_ROUTING */ |
| 104 | { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 }, |
| 105 | 0, |
| 106 | sizeof(struct ip6t_entry), |
| 107 | sizeof(struct ip6t_standard), |
| 108 | 0, { 0, 0 }, { } }, |
| 109 | { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } }, |
| 110 | -NF_ACCEPT - 1 } } |
| 111 | }, |
| 112 | /* ERROR */ |
| 113 | { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 }, |
| 114 | 0, |
| 115 | sizeof(struct ip6t_entry), |
| 116 | sizeof(struct ip6t_error), |
| 117 | 0, { 0, 0 }, { } }, |
| 118 | { { { { IP6T_ALIGN(sizeof(struct ip6t_error_target)), IP6T_ERROR_TARGET } }, |
| 119 | { } }, |
| 120 | "ERROR" |
| 121 | } |
| 122 | } |
| 123 | }; |
| 124 | |
| 125 | static struct ip6t_table packet_mangler = { |
| 126 | .name = "mangle", |
| 127 | .valid_hooks = MANGLE_VALID_HOOKS, |
| 128 | .lock = RW_LOCK_UNLOCKED, |
| 129 | .me = THIS_MODULE, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 130 | .af = AF_INET6, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | }; |
| 132 | |
| 133 | /* The work comes in here from netfilter.c. */ |
| 134 | static unsigned int |
| 135 | ip6t_route_hook(unsigned int hook, |
| 136 | struct sk_buff **pskb, |
| 137 | const struct net_device *in, |
| 138 | const struct net_device *out, |
| 139 | int (*okfn)(struct sk_buff *)) |
| 140 | { |
| 141 | return ip6t_do_table(pskb, hook, in, out, &packet_mangler, NULL); |
| 142 | } |
| 143 | |
| 144 | static unsigned int |
| 145 | ip6t_local_hook(unsigned int hook, |
| 146 | struct sk_buff **pskb, |
| 147 | const struct net_device *in, |
| 148 | const struct net_device *out, |
| 149 | int (*okfn)(struct sk_buff *)) |
| 150 | { |
| 151 | |
| 152 | unsigned long nfmark; |
| 153 | unsigned int ret; |
| 154 | struct in6_addr saddr, daddr; |
| 155 | u_int8_t hop_limit; |
| 156 | u_int32_t flowlabel; |
| 157 | |
| 158 | #if 0 |
| 159 | /* root is playing with raw sockets. */ |
| 160 | if ((*pskb)->len < sizeof(struct iphdr) |
| 161 | || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) { |
| 162 | if (net_ratelimit()) |
| 163 | printk("ip6t_hook: happy cracking.\n"); |
| 164 | return NF_ACCEPT; |
| 165 | } |
| 166 | #endif |
| 167 | |
| 168 | /* save source/dest address, nfmark, hoplimit, flowlabel, priority, */ |
| 169 | memcpy(&saddr, &(*pskb)->nh.ipv6h->saddr, sizeof(saddr)); |
| 170 | memcpy(&daddr, &(*pskb)->nh.ipv6h->daddr, sizeof(daddr)); |
| 171 | nfmark = (*pskb)->nfmark; |
| 172 | hop_limit = (*pskb)->nh.ipv6h->hop_limit; |
| 173 | |
| 174 | /* flowlabel and prio (includes version, which shouldn't change either */ |
| 175 | flowlabel = *((u_int32_t *) (*pskb)->nh.ipv6h); |
| 176 | |
| 177 | ret = ip6t_do_table(pskb, hook, in, out, &packet_mangler, NULL); |
| 178 | |
| 179 | if (ret != NF_DROP && ret != NF_STOLEN |
| 180 | && (memcmp(&(*pskb)->nh.ipv6h->saddr, &saddr, sizeof(saddr)) |
| 181 | || memcmp(&(*pskb)->nh.ipv6h->daddr, &daddr, sizeof(daddr)) |
| 182 | || (*pskb)->nfmark != nfmark |
| 183 | || (*pskb)->nh.ipv6h->hop_limit != hop_limit)) { |
| 184 | |
| 185 | /* something which could affect routing has changed */ |
| 186 | |
| 187 | DEBUGP("ip6table_mangle: we'd need to re-route a packet\n"); |
| 188 | } |
| 189 | |
| 190 | return ret; |
| 191 | } |
| 192 | |
| 193 | static struct nf_hook_ops ip6t_ops[] = { |
| 194 | { |
| 195 | .hook = ip6t_route_hook, |
| 196 | .owner = THIS_MODULE, |
| 197 | .pf = PF_INET6, |
| 198 | .hooknum = NF_IP6_PRE_ROUTING, |
| 199 | .priority = NF_IP6_PRI_MANGLE, |
| 200 | }, |
| 201 | { |
| 202 | .hook = ip6t_local_hook, |
| 203 | .owner = THIS_MODULE, |
| 204 | .pf = PF_INET6, |
| 205 | .hooknum = NF_IP6_LOCAL_IN, |
| 206 | .priority = NF_IP6_PRI_MANGLE, |
| 207 | }, |
| 208 | { |
| 209 | .hook = ip6t_route_hook, |
| 210 | .owner = THIS_MODULE, |
| 211 | .pf = PF_INET6, |
| 212 | .hooknum = NF_IP6_FORWARD, |
| 213 | .priority = NF_IP6_PRI_MANGLE, |
| 214 | }, |
| 215 | { |
| 216 | .hook = ip6t_local_hook, |
| 217 | .owner = THIS_MODULE, |
| 218 | .pf = PF_INET6, |
| 219 | .hooknum = NF_IP6_LOCAL_OUT, |
| 220 | .priority = NF_IP6_PRI_MANGLE, |
| 221 | }, |
| 222 | { |
| 223 | .hook = ip6t_route_hook, |
| 224 | .owner = THIS_MODULE, |
| 225 | .pf = PF_INET6, |
| 226 | .hooknum = NF_IP6_POST_ROUTING, |
| 227 | .priority = NF_IP6_PRI_MANGLE, |
| 228 | }, |
| 229 | }; |
| 230 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 231 | static int __init ip6table_mangle_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 232 | { |
| 233 | int ret; |
| 234 | |
| 235 | /* Register table */ |
| 236 | ret = ip6t_register_table(&packet_mangler, &initial_table.repl); |
| 237 | if (ret < 0) |
| 238 | return ret; |
| 239 | |
| 240 | /* Register hooks */ |
| 241 | ret = nf_register_hook(&ip6t_ops[0]); |
| 242 | if (ret < 0) |
| 243 | goto cleanup_table; |
| 244 | |
| 245 | ret = nf_register_hook(&ip6t_ops[1]); |
| 246 | if (ret < 0) |
| 247 | goto cleanup_hook0; |
| 248 | |
| 249 | ret = nf_register_hook(&ip6t_ops[2]); |
| 250 | if (ret < 0) |
| 251 | goto cleanup_hook1; |
| 252 | |
| 253 | ret = nf_register_hook(&ip6t_ops[3]); |
| 254 | if (ret < 0) |
| 255 | goto cleanup_hook2; |
| 256 | |
| 257 | ret = nf_register_hook(&ip6t_ops[4]); |
| 258 | if (ret < 0) |
| 259 | goto cleanup_hook3; |
| 260 | |
| 261 | return ret; |
| 262 | |
| 263 | cleanup_hook3: |
| 264 | nf_unregister_hook(&ip6t_ops[3]); |
| 265 | cleanup_hook2: |
| 266 | nf_unregister_hook(&ip6t_ops[2]); |
| 267 | cleanup_hook1: |
| 268 | nf_unregister_hook(&ip6t_ops[1]); |
| 269 | cleanup_hook0: |
| 270 | nf_unregister_hook(&ip6t_ops[0]); |
| 271 | cleanup_table: |
| 272 | ip6t_unregister_table(&packet_mangler); |
| 273 | |
| 274 | return ret; |
| 275 | } |
| 276 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 277 | static void __exit ip6table_mangle_fini(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 278 | { |
| 279 | unsigned int i; |
| 280 | |
| 281 | for (i = 0; i < sizeof(ip6t_ops)/sizeof(struct nf_hook_ops); i++) |
| 282 | nf_unregister_hook(&ip6t_ops[i]); |
| 283 | |
| 284 | ip6t_unregister_table(&packet_mangler); |
| 285 | } |
| 286 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 287 | module_init(ip6table_mangle_init); |
| 288 | module_exit(ip6table_mangle_fini); |