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	 60365049cc
			
		
	
	
		60365049cc
		
	
	
	
	
		
			
			On a parisc64 kernel I sometimes notice this kernel warning:
Kernel unaligned access to 0x40ff8814 at ndisc_send_skb+0xc0/0x4d8
The address 0x40ff8814 points to the in6addr_linklocal_allrouters
variable and the warning simply means that some ipv6 function tries to
read a 64-bit word directly from the not-64-bit aligned
in6addr_linklocal_allrouters variable.
Unaligned accesses are non-critical as the architecture or exception
handlers usually will fix it up at runtime. Nevertheless it may trigger
a performance penality for some architectures. For details read the
"unaligned-memory-access" kernel documentation.
The patch below ensures that the ipv6 loopback and router addresses will
always be naturally aligned. This prevents the unaligned accesses for
all architectures.
Signed-off-by: Helge Deller <deller@gmx.de>
Fixes: 034dfc5df9 ("ipv6: export in6addr_loopback to modules")
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/ZbNuFM1bFqoH-UoY@p100
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
		
	
			
		
			
				
	
	
		
			280 lines
		
	
	
	
		
			8.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			280 lines
		
	
	
	
		
			8.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-only
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| /*
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|  * IPv6 library code, needed by static components when full IPv6 support is
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|  * not configured or static.
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|  */
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| 
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| #include <linux/export.h>
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| #include <net/ipv6.h>
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| #include <net/ipv6_stubs.h>
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| #include <net/addrconf.h>
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| #include <net/ip.h>
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| 
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| /* if ipv6 module registers this function is used by xfrm to force all
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|  * sockets to relookup their nodes - this is fairly expensive, be
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|  * careful
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|  */
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| void (*__fib6_flush_trees)(struct net *);
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| EXPORT_SYMBOL(__fib6_flush_trees);
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| 
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| #define IPV6_ADDR_SCOPE_TYPE(scope)	((scope) << 16)
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| 
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| static inline unsigned int ipv6_addr_scope2type(unsigned int scope)
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| {
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| 	switch (scope) {
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| 	case IPV6_ADDR_SCOPE_NODELOCAL:
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| 		return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_NODELOCAL) |
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| 			IPV6_ADDR_LOOPBACK);
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| 	case IPV6_ADDR_SCOPE_LINKLOCAL:
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| 		return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL) |
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| 			IPV6_ADDR_LINKLOCAL);
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| 	case IPV6_ADDR_SCOPE_SITELOCAL:
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| 		return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL) |
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| 			IPV6_ADDR_SITELOCAL);
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| 	}
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| 	return IPV6_ADDR_SCOPE_TYPE(scope);
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| }
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| 
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| int __ipv6_addr_type(const struct in6_addr *addr)
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| {
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| 	__be32 st;
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| 
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| 	st = addr->s6_addr32[0];
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| 
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| 	/* Consider all addresses with the first three bits different of
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| 	   000 and 111 as unicasts.
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| 	 */
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| 	if ((st & htonl(0xE0000000)) != htonl(0x00000000) &&
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| 	    (st & htonl(0xE0000000)) != htonl(0xE0000000))
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| 		return (IPV6_ADDR_UNICAST |
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| 			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));
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| 
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| 	if ((st & htonl(0xFF000000)) == htonl(0xFF000000)) {
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| 		/* multicast */
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| 		/* addr-select 3.1 */
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| 		return (IPV6_ADDR_MULTICAST |
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| 			ipv6_addr_scope2type(IPV6_ADDR_MC_SCOPE(addr)));
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| 	}
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| 
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| 	if ((st & htonl(0xFFC00000)) == htonl(0xFE800000))
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| 		return (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST |
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| 			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));		/* addr-select 3.1 */
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| 	if ((st & htonl(0xFFC00000)) == htonl(0xFEC00000))
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| 		return (IPV6_ADDR_SITELOCAL | IPV6_ADDR_UNICAST |
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| 			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL));		/* addr-select 3.1 */
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| 	if ((st & htonl(0xFE000000)) == htonl(0xFC000000))
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| 		return (IPV6_ADDR_UNICAST |
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| 			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));			/* RFC 4193 */
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| 
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| 	if ((addr->s6_addr32[0] | addr->s6_addr32[1]) == 0) {
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| 		if (addr->s6_addr32[2] == 0) {
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| 			if (addr->s6_addr32[3] == 0)
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| 				return IPV6_ADDR_ANY;
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| 
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| 			if (addr->s6_addr32[3] == htonl(0x00000001))
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| 				return (IPV6_ADDR_LOOPBACK | IPV6_ADDR_UNICAST |
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| 					IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));	/* addr-select 3.4 */
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| 
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| 			return (IPV6_ADDR_COMPATv4 | IPV6_ADDR_UNICAST |
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| 				IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));	/* addr-select 3.3 */
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| 		}
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| 
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| 		if (addr->s6_addr32[2] == htonl(0x0000ffff))
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| 			return (IPV6_ADDR_MAPPED |
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| 				IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));	/* addr-select 3.3 */
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| 	}
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| 
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| 	return (IPV6_ADDR_UNICAST |
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| 		IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));	/* addr-select 3.4 */
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| }
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| EXPORT_SYMBOL(__ipv6_addr_type);
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| 
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| static ATOMIC_NOTIFIER_HEAD(inet6addr_chain);
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| static BLOCKING_NOTIFIER_HEAD(inet6addr_validator_chain);
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| 
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| int register_inet6addr_notifier(struct notifier_block *nb)
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| {
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| 	return atomic_notifier_chain_register(&inet6addr_chain, nb);
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| }
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| EXPORT_SYMBOL(register_inet6addr_notifier);
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| 
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| int unregister_inet6addr_notifier(struct notifier_block *nb)
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| {
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| 	return atomic_notifier_chain_unregister(&inet6addr_chain, nb);
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| }
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| EXPORT_SYMBOL(unregister_inet6addr_notifier);
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| 
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| int inet6addr_notifier_call_chain(unsigned long val, void *v)
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| {
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| 	return atomic_notifier_call_chain(&inet6addr_chain, val, v);
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| }
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| EXPORT_SYMBOL(inet6addr_notifier_call_chain);
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| 
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| int register_inet6addr_validator_notifier(struct notifier_block *nb)
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| {
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| 	return blocking_notifier_chain_register(&inet6addr_validator_chain, nb);
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| }
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| EXPORT_SYMBOL(register_inet6addr_validator_notifier);
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| 
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| int unregister_inet6addr_validator_notifier(struct notifier_block *nb)
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| {
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| 	return blocking_notifier_chain_unregister(&inet6addr_validator_chain,
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| 						  nb);
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| }
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| EXPORT_SYMBOL(unregister_inet6addr_validator_notifier);
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| 
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| int inet6addr_validator_notifier_call_chain(unsigned long val, void *v)
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| {
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| 	return blocking_notifier_call_chain(&inet6addr_validator_chain, val, v);
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| }
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| EXPORT_SYMBOL(inet6addr_validator_notifier_call_chain);
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| 
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| static struct dst_entry *eafnosupport_ipv6_dst_lookup_flow(struct net *net,
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| 							   const struct sock *sk,
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| 							   struct flowi6 *fl6,
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| 							   const struct in6_addr *final_dst)
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| {
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| 	return ERR_PTR(-EAFNOSUPPORT);
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| }
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| 
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| static int eafnosupport_ipv6_route_input(struct sk_buff *skb)
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| {
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| 	return -EAFNOSUPPORT;
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| }
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| 
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| static struct fib6_table *eafnosupport_fib6_get_table(struct net *net, u32 id)
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| {
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| 	return NULL;
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| }
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| 
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| static int
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| eafnosupport_fib6_table_lookup(struct net *net, struct fib6_table *table,
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| 			       int oif, struct flowi6 *fl6,
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| 			       struct fib6_result *res, int flags)
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| {
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| 	return -EAFNOSUPPORT;
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| }
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| 
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| static int
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| eafnosupport_fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
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| 			 struct fib6_result *res, int flags)
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| {
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| 	return -EAFNOSUPPORT;
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| }
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| 
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| static void
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| eafnosupport_fib6_select_path(const struct net *net, struct fib6_result *res,
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| 			      struct flowi6 *fl6, int oif, bool have_oif_match,
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| 			      const struct sk_buff *skb, int strict)
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| {
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| }
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| 
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| static u32
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| eafnosupport_ip6_mtu_from_fib6(const struct fib6_result *res,
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| 			       const struct in6_addr *daddr,
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| 			       const struct in6_addr *saddr)
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| {
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| 	return 0;
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| }
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| 
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| static int eafnosupport_fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
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| 				     struct fib6_config *cfg, gfp_t gfp_flags,
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| 				     struct netlink_ext_ack *extack)
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| {
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| 	NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
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| 	return -EAFNOSUPPORT;
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| }
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| 
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| static int eafnosupport_ip6_del_rt(struct net *net, struct fib6_info *rt,
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| 				   bool skip_notify)
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| {
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| 	return -EAFNOSUPPORT;
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| }
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| 
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| static int eafnosupport_ipv6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
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| 				      int (*output)(struct net *, struct sock *, struct sk_buff *))
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| {
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| 	kfree_skb(skb);
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| 	return -EAFNOSUPPORT;
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| }
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| 
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| static struct net_device *eafnosupport_ipv6_dev_find(struct net *net, const struct in6_addr *addr,
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| 						     struct net_device *dev)
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| {
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| 	return ERR_PTR(-EAFNOSUPPORT);
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| }
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| 
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| const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
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| 	.ipv6_dst_lookup_flow = eafnosupport_ipv6_dst_lookup_flow,
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| 	.ipv6_route_input  = eafnosupport_ipv6_route_input,
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| 	.fib6_get_table    = eafnosupport_fib6_get_table,
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| 	.fib6_table_lookup = eafnosupport_fib6_table_lookup,
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| 	.fib6_lookup       = eafnosupport_fib6_lookup,
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| 	.fib6_select_path  = eafnosupport_fib6_select_path,
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| 	.ip6_mtu_from_fib6 = eafnosupport_ip6_mtu_from_fib6,
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| 	.fib6_nh_init	   = eafnosupport_fib6_nh_init,
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| 	.ip6_del_rt	   = eafnosupport_ip6_del_rt,
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| 	.ipv6_fragment	   = eafnosupport_ipv6_fragment,
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| 	.ipv6_dev_find     = eafnosupport_ipv6_dev_find,
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| };
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| EXPORT_SYMBOL_GPL(ipv6_stub);
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| 
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| /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
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| const struct in6_addr in6addr_loopback __aligned(BITS_PER_LONG/8)
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| 	= IN6ADDR_LOOPBACK_INIT;
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| EXPORT_SYMBOL(in6addr_loopback);
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| const struct in6_addr in6addr_any __aligned(BITS_PER_LONG/8)
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| 	= IN6ADDR_ANY_INIT;
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| EXPORT_SYMBOL(in6addr_any);
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| const struct in6_addr in6addr_linklocal_allnodes __aligned(BITS_PER_LONG/8)
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| 	= IN6ADDR_LINKLOCAL_ALLNODES_INIT;
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| EXPORT_SYMBOL(in6addr_linklocal_allnodes);
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| const struct in6_addr in6addr_linklocal_allrouters __aligned(BITS_PER_LONG/8)
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| 	= IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
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| EXPORT_SYMBOL(in6addr_linklocal_allrouters);
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| const struct in6_addr in6addr_interfacelocal_allnodes __aligned(BITS_PER_LONG/8)
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| 	= IN6ADDR_INTERFACELOCAL_ALLNODES_INIT;
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| EXPORT_SYMBOL(in6addr_interfacelocal_allnodes);
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| const struct in6_addr in6addr_interfacelocal_allrouters __aligned(BITS_PER_LONG/8)
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| 	= IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT;
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| EXPORT_SYMBOL(in6addr_interfacelocal_allrouters);
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| const struct in6_addr in6addr_sitelocal_allrouters __aligned(BITS_PER_LONG/8)
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| 	= IN6ADDR_SITELOCAL_ALLROUTERS_INIT;
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| EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
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| 
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| static void snmp6_free_dev(struct inet6_dev *idev)
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| {
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| 	kfree(idev->stats.icmpv6msgdev);
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| 	kfree(idev->stats.icmpv6dev);
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| 	free_percpu(idev->stats.ipv6);
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| }
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| 
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| static void in6_dev_finish_destroy_rcu(struct rcu_head *head)
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| {
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| 	struct inet6_dev *idev = container_of(head, struct inet6_dev, rcu);
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| 
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| 	snmp6_free_dev(idev);
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| 	kfree(idev);
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| }
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| 
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| /* Nobody refers to this device, we may destroy it. */
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| 
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| void in6_dev_finish_destroy(struct inet6_dev *idev)
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| {
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| 	struct net_device *dev = idev->dev;
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| 
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| 	WARN_ON(!list_empty(&idev->addr_list));
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| 	WARN_ON(rcu_access_pointer(idev->mc_list));
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| 	WARN_ON(timer_pending(&idev->rs_timer));
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| 
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| #ifdef NET_REFCNT_DEBUG
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| 	pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
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| #endif
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| 	netdev_put(dev, &idev->dev_tracker);
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| 	if (!idev->dead) {
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| 		pr_warn("Freeing alive inet6 device %p\n", idev);
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| 		return;
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| 	}
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| 	call_rcu(&idev->rcu, in6_dev_finish_destroy_rcu);
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| }
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| EXPORT_SYMBOL(in6_dev_finish_destroy);
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