/* * 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",	.table		= &initial_table.repl,	.valid_hooks	= MANGLE_VALID_HOOKS,	.lock		= RW_LOCK_UNLOCKED,	.me		= THIS_MODULE,};/* The work comes in here from netfilter.c. */static unsigned intip6t_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, NULL);}static unsigned intip6t_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 long nfmark;	unsigned int ret;	struct in6_addr saddr, daddr;	u_int8_t hop_limit;	u_int32_t flowlabel;#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	/* FIXME: Push down to extensions --RR */	if (skb_is_nonlinear(*pskb) && skb_linearize(*pskb, GFP_ATOMIC) != 0)		return NF_DROP;	/* save source/dest address, nfmark, hoplimit, flowlabel, priority,  */	memcpy(&saddr, &(*pskb)->nh.ipv6h->saddr, sizeof(saddr));	memcpy(&daddr, &(*pskb)->nh.ipv6h->daddr, sizeof(daddr));	nfmark = (*pskb)->nfmark;	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, NULL);	if (ret != NF_DROP && ret != NF_STOLEN 		&& (memcmp(&(*pskb)->nh.ipv6h->saddr, &saddr, sizeof(saddr))		    || memcmp(&(*pskb)->nh.ipv6h->daddr, &daddr, sizeof(daddr))		    || (*pskb)->nfmark != nfmark		    || (*pskb)->nh.ipv6h->hop_limit != hop_limit)) {		/* something which could affect routing has changed */		DEBUGP("ip6table_mangle: we'd need to re-route a packet\n");	}	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 init(void){	int ret;	/* Register table */	ret = ip6t_register_table(&packet_mangler);	if (ret < 0)		return ret;	/* Register hooks */	ret = nf_register_hook(&ip6t_ops[0]);	if (ret < 0)		goto cleanup_table;	ret = nf_register_hook(&ip6t_ops[1]);	if (ret < 0)		goto cleanup_hook0;	ret = nf_register_hook(&ip6t_ops[2]);	if (ret < 0)		goto cleanup_hook1;	ret = nf_register_hook(&ip6t_ops[3]);	if (ret < 0)		goto cleanup_hook2;	ret = nf_register_hook(&ip6t_ops[4]);	if (ret < 0)		goto cleanup_hook3;	return ret; cleanup_hook3:        nf_unregister_hook(&ip6t_ops[3]); cleanup_hook2:	nf_unregister_hook(&ip6t_ops[2]); cleanup_hook1:	nf_unregister_hook(&ip6t_ops[1]); cleanup_hook0:	nf_unregister_hook(&ip6t_ops[0]); cleanup_table:	ip6t_unregister_table(&packet_mangler);	return ret;}static void __exit fini(void){	unsigned int i;	for (i = 0; i < sizeof(ip6t_ops)/sizeof(struct nf_hook_ops); i++)		nf_unregister_hook(&ip6t_ops[i]);	ip6t_unregister_table(&packet_mangler);}module_init(init);module_exit(fini);