268 lines
		
	
	
		
			8.1 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			268 lines
		
	
	
		
			8.1 KiB
		
	
	
	
		
			C
		
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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| /*
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|  * Compatibility interface for userspace libc header coordination:
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|  *
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|  * Define compatibility macros that are used to control the inclusion or
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|  * exclusion of UAPI structures and definitions in coordination with another
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|  * userspace C library.
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|  *
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|  * This header is intended to solve the problem of UAPI definitions that
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|  * conflict with userspace definitions. If a UAPI header has such conflicting
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|  * definitions then the solution is as follows:
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|  *
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|  * * Synchronize the UAPI header and the libc headers so either one can be
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|  *   used and such that the ABI is preserved. If this is not possible then
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|  *   no simple compatibility interface exists (you need to write translating
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|  *   wrappers and rename things) and you can't use this interface.
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|  *
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|  * Then follow this process:
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|  *
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|  * (a) Include libc-compat.h in the UAPI header.
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|  *      e.g. #include <linux/libc-compat.h>
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|  *     This include must be as early as possible.
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|  *
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|  * (b) In libc-compat.h add enough code to detect that the comflicting
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|  *     userspace libc header has been included first.
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|  *
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|  * (c) If the userspace libc header has been included first define a set of
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|  *     guard macros of the form __UAPI_DEF_FOO and set their values to 1, else
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|  *     set their values to 0.
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|  *
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|  * (d) Back in the UAPI header with the conflicting definitions, guard the
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|  *     definitions with:
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|  *     #if __UAPI_DEF_FOO
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|  *       ...
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|  *     #endif
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|  *
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|  * This fixes the situation where the linux headers are included *after* the
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|  * libc headers. To fix the problem with the inclusion in the other order the
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|  * userspace libc headers must be fixed like this:
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|  *
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|  * * For all definitions that conflict with kernel definitions wrap those
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|  *   defines in the following:
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|  *   #if !__UAPI_DEF_FOO
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|  *     ...
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|  *   #endif
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|  *
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|  * This prevents the redefinition of a construct already defined by the kernel.
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|  */
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| #ifndef _UAPI_LIBC_COMPAT_H
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| #define _UAPI_LIBC_COMPAT_H
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| 
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| /* We have included glibc headers... */
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| #if defined(__GLIBC__)
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| 
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| /* Coordinate with glibc net/if.h header. */
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| #if defined(_NET_IF_H) && defined(__USE_MISC)
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| 
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| /* GLIBC headers included first so don't define anything
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|  * that would already be defined. */
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| 
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| #define __UAPI_DEF_IF_IFCONF 0
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| #define __UAPI_DEF_IF_IFMAP 0
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| #define __UAPI_DEF_IF_IFNAMSIZ 0
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| #define __UAPI_DEF_IF_IFREQ 0
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| /* Everything up to IFF_DYNAMIC, matches net/if.h until glibc 2.23 */
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| #define __UAPI_DEF_IF_NET_DEVICE_FLAGS 0
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| /* For the future if glibc adds IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO */
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| #ifndef __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO
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| #define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 1
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| #endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO */
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| 
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| #else /* _NET_IF_H */
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| 
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| /* Linux headers included first, and we must define everything
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|  * we need. The expectation is that glibc will check the
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|  * __UAPI_DEF_* defines and adjust appropriately. */
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| 
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| #define __UAPI_DEF_IF_IFCONF 1
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| #define __UAPI_DEF_IF_IFMAP 1
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| #define __UAPI_DEF_IF_IFNAMSIZ 1
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| #define __UAPI_DEF_IF_IFREQ 1
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| /* Everything up to IFF_DYNAMIC, matches net/if.h until glibc 2.23 */
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| #define __UAPI_DEF_IF_NET_DEVICE_FLAGS 1
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| /* For the future if glibc adds IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO */
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| #define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 1
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| 
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| #endif /* _NET_IF_H */
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| 
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| /* Coordinate with glibc netinet/in.h header. */
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| #if defined(_NETINET_IN_H)
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| 
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| /* GLIBC headers included first so don't define anything
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|  * that would already be defined. */
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| #define __UAPI_DEF_IN_ADDR		0
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| #define __UAPI_DEF_IN_IPPROTO		0
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| #define __UAPI_DEF_IN_PKTINFO		0
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| #define __UAPI_DEF_IP_MREQ		0
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| #define __UAPI_DEF_SOCKADDR_IN		0
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| #define __UAPI_DEF_IN_CLASS		0
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| 
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| #define __UAPI_DEF_IN6_ADDR		0
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| /* The exception is the in6_addr macros which must be defined
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|  * if the glibc code didn't define them. This guard matches
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|  * the guard in glibc/inet/netinet/in.h which defines the
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|  * additional in6_addr macros e.g. s6_addr16, and s6_addr32. */
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| #if defined(__USE_MISC) || defined (__USE_GNU)
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| #define __UAPI_DEF_IN6_ADDR_ALT		0
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| #else
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| #define __UAPI_DEF_IN6_ADDR_ALT		1
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| #endif
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| #define __UAPI_DEF_SOCKADDR_IN6		0
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| #define __UAPI_DEF_IPV6_MREQ		0
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| #define __UAPI_DEF_IPPROTO_V6		0
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| #define __UAPI_DEF_IPV6_OPTIONS		0
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| #define __UAPI_DEF_IN6_PKTINFO		0
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| #define __UAPI_DEF_IP6_MTUINFO		0
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| 
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| #else
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| 
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| /* Linux headers included first, and we must define everything
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|  * we need. The expectation is that glibc will check the
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|  * __UAPI_DEF_* defines and adjust appropriately. */
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| #define __UAPI_DEF_IN_ADDR		1
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| #define __UAPI_DEF_IN_IPPROTO		1
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| #define __UAPI_DEF_IN_PKTINFO		1
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| #define __UAPI_DEF_IP_MREQ		1
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| #define __UAPI_DEF_SOCKADDR_IN		1
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| #define __UAPI_DEF_IN_CLASS		1
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| 
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| #define __UAPI_DEF_IN6_ADDR		1
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| /* We unconditionally define the in6_addr macros and glibc must
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|  * coordinate. */
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| #define __UAPI_DEF_IN6_ADDR_ALT		1
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| #define __UAPI_DEF_SOCKADDR_IN6		1
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| #define __UAPI_DEF_IPV6_MREQ		1
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| #define __UAPI_DEF_IPPROTO_V6		1
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| #define __UAPI_DEF_IPV6_OPTIONS		1
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| #define __UAPI_DEF_IN6_PKTINFO		1
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| #define __UAPI_DEF_IP6_MTUINFO		1
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| 
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| #endif /* _NETINET_IN_H */
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| 
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| /* Coordinate with glibc netipx/ipx.h header. */
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| #if defined(__NETIPX_IPX_H)
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| 
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| #define __UAPI_DEF_SOCKADDR_IPX			0
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| #define __UAPI_DEF_IPX_ROUTE_DEFINITION		0
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| #define __UAPI_DEF_IPX_INTERFACE_DEFINITION	0
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| #define __UAPI_DEF_IPX_CONFIG_DATA		0
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| #define __UAPI_DEF_IPX_ROUTE_DEF		0
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| 
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| #else /* defined(__NETIPX_IPX_H) */
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| 
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| #define __UAPI_DEF_SOCKADDR_IPX			1
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| #define __UAPI_DEF_IPX_ROUTE_DEFINITION		1
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| #define __UAPI_DEF_IPX_INTERFACE_DEFINITION	1
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| #define __UAPI_DEF_IPX_CONFIG_DATA		1
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| #define __UAPI_DEF_IPX_ROUTE_DEF		1
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| 
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| #endif /* defined(__NETIPX_IPX_H) */
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| 
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| /* Definitions for xattr.h */
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| #if defined(_SYS_XATTR_H)
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| #define __UAPI_DEF_XATTR		0
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| #else
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| #define __UAPI_DEF_XATTR		1
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| #endif
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| 
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| /* If we did not see any headers from any supported C libraries,
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|  * or we are being included in the kernel, then define everything
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|  * that we need. Check for previous __UAPI_* definitions to give
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|  * unsupported C libraries a way to opt out of any kernel definition. */
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| #else /* !defined(__GLIBC__) */
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| 
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| /* Definitions for if.h */
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| #ifndef __UAPI_DEF_IF_IFCONF
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| #define __UAPI_DEF_IF_IFCONF 1
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| #endif
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| #ifndef __UAPI_DEF_IF_IFMAP
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| #define __UAPI_DEF_IF_IFMAP 1
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| #endif
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| #ifndef __UAPI_DEF_IF_IFNAMSIZ
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| #define __UAPI_DEF_IF_IFNAMSIZ 1
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| #endif
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| #ifndef __UAPI_DEF_IF_IFREQ
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| #define __UAPI_DEF_IF_IFREQ 1
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| #endif
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| /* Everything up to IFF_DYNAMIC, matches net/if.h until glibc 2.23 */
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| #ifndef __UAPI_DEF_IF_NET_DEVICE_FLAGS
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| #define __UAPI_DEF_IF_NET_DEVICE_FLAGS 1
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| #endif
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| /* For the future if glibc adds IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO */
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| #ifndef __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO
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| #define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 1
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| #endif
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| 
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| /* Definitions for in.h */
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| #ifndef __UAPI_DEF_IN_ADDR
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| #define __UAPI_DEF_IN_ADDR		1
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| #endif
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| #ifndef __UAPI_DEF_IN_IPPROTO
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| #define __UAPI_DEF_IN_IPPROTO		1
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| #endif
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| #ifndef __UAPI_DEF_IN_PKTINFO
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| #define __UAPI_DEF_IN_PKTINFO		1
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| #endif
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| #ifndef __UAPI_DEF_IP_MREQ
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| #define __UAPI_DEF_IP_MREQ		1
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| #endif
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| #ifndef __UAPI_DEF_SOCKADDR_IN
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| #define __UAPI_DEF_SOCKADDR_IN		1
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| #endif
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| #ifndef __UAPI_DEF_IN_CLASS
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| #define __UAPI_DEF_IN_CLASS		1
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| #endif
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| 
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| /* Definitions for in6.h */
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| #ifndef __UAPI_DEF_IN6_ADDR
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| #define __UAPI_DEF_IN6_ADDR		1
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| #endif
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| #ifndef __UAPI_DEF_IN6_ADDR_ALT
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| #define __UAPI_DEF_IN6_ADDR_ALT		1
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| #endif
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| #ifndef __UAPI_DEF_SOCKADDR_IN6
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| #define __UAPI_DEF_SOCKADDR_IN6		1
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| #endif
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| #ifndef __UAPI_DEF_IPV6_MREQ
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| #define __UAPI_DEF_IPV6_MREQ		1
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| #endif
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| #ifndef __UAPI_DEF_IPPROTO_V6
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| #define __UAPI_DEF_IPPROTO_V6		1
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| #endif
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| #ifndef __UAPI_DEF_IPV6_OPTIONS
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| #define __UAPI_DEF_IPV6_OPTIONS		1
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| #endif
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| #ifndef __UAPI_DEF_IN6_PKTINFO
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| #define __UAPI_DEF_IN6_PKTINFO		1
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| #endif
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| #ifndef __UAPI_DEF_IP6_MTUINFO
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| #define __UAPI_DEF_IP6_MTUINFO		1
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| #endif
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| 
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| /* Definitions for ipx.h */
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| #ifndef __UAPI_DEF_SOCKADDR_IPX
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| #define __UAPI_DEF_SOCKADDR_IPX			1
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| #endif
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| #ifndef __UAPI_DEF_IPX_ROUTE_DEFINITION
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| #define __UAPI_DEF_IPX_ROUTE_DEFINITION		1
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| #endif
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| #ifndef __UAPI_DEF_IPX_INTERFACE_DEFINITION
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| #define __UAPI_DEF_IPX_INTERFACE_DEFINITION	1
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| #endif
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| #ifndef __UAPI_DEF_IPX_CONFIG_DATA
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| #define __UAPI_DEF_IPX_CONFIG_DATA		1
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| #endif
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| #ifndef __UAPI_DEF_IPX_ROUTE_DEF
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| #define __UAPI_DEF_IPX_ROUTE_DEF		1
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| #endif
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| 
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| /* Definitions for xattr.h */
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| #ifndef __UAPI_DEF_XATTR
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| #define __UAPI_DEF_XATTR		1
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| #endif
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| 
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| #endif /* __GLIBC__ */
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| 
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| #endif /* _UAPI_LIBC_COMPAT_H */
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