| /* |
| * IPv6 packet mangling table, a port of the IPv4 mangle table to IPv6 |
| * |
| * Copyright (C) 2000-2001 by Harald Welte <laforge@gnumonks.org> |
| * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * Extended to all five netfilter hooks by Brad Chapman & Harald Welte |
| */ |
| #include <linux/module.h> |
| #include <linux/netfilter_ipv6/ip6_tables.h> |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); |
| MODULE_DESCRIPTION("ip6tables mangle table"); |
| |
| #define MANGLE_VALID_HOOKS ((1 << NF_IP6_PRE_ROUTING) | \ |
| (1 << NF_IP6_LOCAL_IN) | \ |
| (1 << NF_IP6_FORWARD) | \ |
| (1 << NF_IP6_LOCAL_OUT) | \ |
| (1 << NF_IP6_POST_ROUTING)) |
| |
| #if 0 |
| #define DEBUGP(x, args...) printk(KERN_DEBUG x, ## args) |
| #else |
| #define DEBUGP(x, args...) |
| #endif |
| |
| /* Standard entry. */ |
| struct ip6t_standard |
| { |
| struct ip6t_entry entry; |
| struct ip6t_standard_target target; |
| }; |
| |
| struct ip6t_error_target |
| { |
| struct ip6t_entry_target target; |
| char errorname[IP6T_FUNCTION_MAXNAMELEN]; |
| }; |
| |
| struct ip6t_error |
| { |
| struct ip6t_entry entry; |
| struct ip6t_error_target target; |
| }; |
| |
| static struct |
| { |
| struct ip6t_replace repl; |
| struct ip6t_standard entries[5]; |
| struct ip6t_error term; |
| } initial_table __initdata |
| = { { "mangle", MANGLE_VALID_HOOKS, 6, |
| sizeof(struct ip6t_standard) * 5 + sizeof(struct ip6t_error), |
| { [NF_IP6_PRE_ROUTING] = 0, |
| [NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard), |
| [NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2, |
| [NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3, |
| [NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4}, |
| { [NF_IP6_PRE_ROUTING] = 0, |
| [NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard), |
| [NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2, |
| [NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3, |
| [NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4}, |
| 0, NULL, { } }, |
| { |
| /* PRE_ROUTING */ |
| { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 }, |
| 0, |
| sizeof(struct ip6t_entry), |
| sizeof(struct ip6t_standard), |
| 0, { 0, 0 }, { } }, |
| { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } }, |
| -NF_ACCEPT - 1 } }, |
| /* LOCAL_IN */ |
| { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 }, |
| 0, |
| sizeof(struct ip6t_entry), |
| sizeof(struct ip6t_standard), |
| 0, { 0, 0 }, { } }, |
| { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } }, |
| -NF_ACCEPT - 1 } }, |
| /* FORWARD */ |
| { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 }, |
| 0, |
| sizeof(struct ip6t_entry), |
| sizeof(struct ip6t_standard), |
| 0, { 0, 0 }, { } }, |
| { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } }, |
| -NF_ACCEPT - 1 } }, |
| /* LOCAL_OUT */ |
| { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 }, |
| 0, |
| sizeof(struct ip6t_entry), |
| sizeof(struct ip6t_standard), |
| 0, { 0, 0 }, { } }, |
| { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } }, |
| -NF_ACCEPT - 1 } }, |
| /* POST_ROUTING */ |
| { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 }, |
| 0, |
| sizeof(struct ip6t_entry), |
| sizeof(struct ip6t_standard), |
| 0, { 0, 0 }, { } }, |
| { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } }, |
| -NF_ACCEPT - 1 } } |
| }, |
| /* ERROR */ |
| { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 }, |
| 0, |
| sizeof(struct ip6t_entry), |
| sizeof(struct ip6t_error), |
| 0, { 0, 0 }, { } }, |
| { { { { IP6T_ALIGN(sizeof(struct ip6t_error_target)), IP6T_ERROR_TARGET } }, |
| { } }, |
| "ERROR" |
| } |
| } |
| }; |
| |
| static struct ip6t_table packet_mangler = { |
| .name = "mangle", |
| .valid_hooks = MANGLE_VALID_HOOKS, |
| .lock = RW_LOCK_UNLOCKED, |
| .me = THIS_MODULE, |
| .af = AF_INET6, |
| }; |
| |
| /* The work comes in here from netfilter.c. */ |
| static unsigned int |
| ip6t_route_hook(unsigned int hook, |
| struct sk_buff **pskb, |
| const struct net_device *in, |
| const struct net_device *out, |
| int (*okfn)(struct sk_buff *)) |
| { |
| return ip6t_do_table(pskb, hook, in, out, &packet_mangler); |
| } |
| |
| static unsigned int |
| ip6t_local_hook(unsigned int hook, |
| struct sk_buff **pskb, |
| const struct net_device *in, |
| const struct net_device *out, |
| int (*okfn)(struct sk_buff *)) |
| { |
| |
| unsigned int ret; |
| struct in6_addr saddr, daddr; |
| u_int8_t hop_limit; |
| u_int32_t flowlabel, mark; |
| |
| #if 0 |
| /* root is playing with raw sockets. */ |
| if ((*pskb)->len < sizeof(struct iphdr) |
| || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) { |
| if (net_ratelimit()) |
| printk("ip6t_hook: happy cracking.\n"); |
| return NF_ACCEPT; |
| } |
| #endif |
| |
| /* save source/dest address, mark, hoplimit, flowlabel, priority, */ |
| memcpy(&saddr, &(*pskb)->nh.ipv6h->saddr, sizeof(saddr)); |
| memcpy(&daddr, &(*pskb)->nh.ipv6h->daddr, sizeof(daddr)); |
| mark = (*pskb)->mark; |
| hop_limit = (*pskb)->nh.ipv6h->hop_limit; |
| |
| /* flowlabel and prio (includes version, which shouldn't change either */ |
| flowlabel = *((u_int32_t *) (*pskb)->nh.ipv6h); |
| |
| ret = ip6t_do_table(pskb, hook, in, out, &packet_mangler); |
| |
| if (ret != NF_DROP && ret != NF_STOLEN |
| && (memcmp(&(*pskb)->nh.ipv6h->saddr, &saddr, sizeof(saddr)) |
| || memcmp(&(*pskb)->nh.ipv6h->daddr, &daddr, sizeof(daddr)) |
| || (*pskb)->mark != mark |
| || (*pskb)->nh.ipv6h->hop_limit != hop_limit)) |
| return ip6_route_me_harder(*pskb) == 0 ? ret : NF_DROP; |
| |
| return ret; |
| } |
| |
| static struct nf_hook_ops ip6t_ops[] = { |
| { |
| .hook = ip6t_route_hook, |
| .owner = THIS_MODULE, |
| .pf = PF_INET6, |
| .hooknum = NF_IP6_PRE_ROUTING, |
| .priority = NF_IP6_PRI_MANGLE, |
| }, |
| { |
| .hook = ip6t_local_hook, |
| .owner = THIS_MODULE, |
| .pf = PF_INET6, |
| .hooknum = NF_IP6_LOCAL_IN, |
| .priority = NF_IP6_PRI_MANGLE, |
| }, |
| { |
| .hook = ip6t_route_hook, |
| .owner = THIS_MODULE, |
| .pf = PF_INET6, |
| .hooknum = NF_IP6_FORWARD, |
| .priority = NF_IP6_PRI_MANGLE, |
| }, |
| { |
| .hook = ip6t_local_hook, |
| .owner = THIS_MODULE, |
| .pf = PF_INET6, |
| .hooknum = NF_IP6_LOCAL_OUT, |
| .priority = NF_IP6_PRI_MANGLE, |
| }, |
| { |
| .hook = ip6t_route_hook, |
| .owner = THIS_MODULE, |
| .pf = PF_INET6, |
| .hooknum = NF_IP6_POST_ROUTING, |
| .priority = NF_IP6_PRI_MANGLE, |
| }, |
| }; |
| |
| static int __init ip6table_mangle_init(void) |
| { |
| int ret; |
| |
| /* Register table */ |
| ret = ip6t_register_table(&packet_mangler, &initial_table.repl); |
| if (ret < 0) |
| return ret; |
| |
| /* Register hooks */ |
| ret = nf_register_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops)); |
| if (ret < 0) |
| goto cleanup_table; |
| |
| return ret; |
| |
| cleanup_table: |
| ip6t_unregister_table(&packet_mangler); |
| return ret; |
| } |
| |
| static void __exit ip6table_mangle_fini(void) |
| { |
| nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops)); |
| ip6t_unregister_table(&packet_mangler); |
| } |
| |
| module_init(ip6table_mangle_init); |
| module_exit(ip6table_mangle_fini); |