180 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			180 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* tunnel4.c: Generic IP tunnel transformer.
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 *
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 * Copyright (C) 2003 David S. Miller (davem@redhat.com)
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 */
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/netdevice.h>
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#include <linux/skbuff.h>
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#include <net/icmp.h>
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#include <net/ip.h>
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#include <net/protocol.h>
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#include <net/xfrm.h>
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static struct xfrm_tunnel *tunnel4_handlers;
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static struct xfrm_tunnel *tunnel64_handlers;
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static DEFINE_MUTEX(tunnel4_mutex);
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static inline struct xfrm_tunnel **fam_handlers(unsigned short family)
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{
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	return (family == AF_INET) ? &tunnel4_handlers : &tunnel64_handlers;
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}
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int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family)
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{
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	struct xfrm_tunnel **pprev;
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	int ret = -EEXIST;
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	int priority = handler->priority;
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	mutex_lock(&tunnel4_mutex);
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	for (pprev = fam_handlers(family); *pprev; pprev = &(*pprev)->next) {
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		if ((*pprev)->priority > priority)
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			break;
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		if ((*pprev)->priority == priority)
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			goto err;
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	}
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	handler->next = *pprev;
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	*pprev = handler;
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	ret = 0;
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err:
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	mutex_unlock(&tunnel4_mutex);
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	return ret;
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}
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EXPORT_SYMBOL(xfrm4_tunnel_register);
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int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family)
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{
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	struct xfrm_tunnel **pprev;
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	int ret = -ENOENT;
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	mutex_lock(&tunnel4_mutex);
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	for (pprev = fam_handlers(family); *pprev; pprev = &(*pprev)->next) {
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		if (*pprev == handler) {
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			*pprev = handler->next;
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			ret = 0;
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			break;
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		}
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	}
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	mutex_unlock(&tunnel4_mutex);
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	synchronize_net();
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	return ret;
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}
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EXPORT_SYMBOL(xfrm4_tunnel_deregister);
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static int tunnel4_rcv(struct sk_buff *skb)
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{
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	struct xfrm_tunnel *handler;
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	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
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		goto drop;
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	for (handler = tunnel4_handlers; handler; handler = handler->next)
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		if (!handler->handler(skb))
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			return 0;
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	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
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drop:
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	kfree_skb(skb);
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	return 0;
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}
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#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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static int tunnel64_rcv(struct sk_buff *skb)
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{
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	struct xfrm_tunnel *handler;
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	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
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		goto drop;
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	for (handler = tunnel64_handlers; handler; handler = handler->next)
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		if (!handler->handler(skb))
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			return 0;
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	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
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drop:
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	kfree_skb(skb);
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	return 0;
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}
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#endif
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static void tunnel4_err(struct sk_buff *skb, u32 info)
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{
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	struct xfrm_tunnel *handler;
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	for (handler = tunnel4_handlers; handler; handler = handler->next)
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		if (!handler->err_handler(skb, info))
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			break;
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}
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#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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static void tunnel64_err(struct sk_buff *skb, u32 info)
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{
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	struct xfrm_tunnel *handler;
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	for (handler = tunnel64_handlers; handler; handler = handler->next)
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		if (!handler->err_handler(skb, info))
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			break;
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}
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#endif
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static const struct net_protocol tunnel4_protocol = {
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	.handler	=	tunnel4_rcv,
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	.err_handler	=	tunnel4_err,
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	.no_policy	=	1,
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	.netns_ok	=	1,
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};
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#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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static const struct net_protocol tunnel64_protocol = {
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	.handler	=	tunnel64_rcv,
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	.err_handler	=	tunnel64_err,
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	.no_policy	=	1,
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	.netns_ok	=	1,
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};
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#endif
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static int __init tunnel4_init(void)
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{
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	if (inet_add_protocol(&tunnel4_protocol, IPPROTO_IPIP)) {
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		printk(KERN_ERR "tunnel4 init: can't add protocol\n");
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		return -EAGAIN;
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	}
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#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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	if (inet_add_protocol(&tunnel64_protocol, IPPROTO_IPV6)) {
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		printk(KERN_ERR "tunnel64 init: can't add protocol\n");
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		inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP);
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		return -EAGAIN;
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	}
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#endif
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	return 0;
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}
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static void __exit tunnel4_fini(void)
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{
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#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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	if (inet_del_protocol(&tunnel64_protocol, IPPROTO_IPV6))
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		printk(KERN_ERR "tunnel64 close: can't remove protocol\n");
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#endif
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	if (inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP))
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		printk(KERN_ERR "tunnel4 close: can't remove protocol\n");
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}
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module_init(tunnel4_init);
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module_exit(tunnel4_fini);
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MODULE_LICENSE("GPL");
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