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-rw-r--r--include/linux/compiler_types.h246
-rw-r--r--include/linux/if.h296
-rw-r--r--include/linux/libc-compat.h267
3 files changed, 809 insertions, 0 deletions
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
new file mode 100644
index 000000000..72393a8c1
--- /dev/null
+++ b/include/linux/compiler_types.h
@@ -0,0 +1,246 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_COMPILER_TYPES_H
+#define __LINUX_COMPILER_TYPES_H
+
+#ifndef __ASSEMBLY__
+
+#ifdef __CHECKER__
+# define __user __attribute__((noderef, address_space(1)))
+# define __kernel __attribute__((address_space(0)))
+# define __safe __attribute__((safe))
+# define __force __attribute__((force))
+# define __nocast __attribute__((nocast))
+# define __iomem __attribute__((noderef, address_space(2)))
+# define __must_hold(x) __attribute__((context(x,1,1)))
+# define __acquires(x) __attribute__((context(x,0,1)))
+# define __releases(x) __attribute__((context(x,1,0)))
+# define __acquire(x) __context__(x,1)
+# define __release(x) __context__(x,-1)
+# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
+# define __percpu __attribute__((noderef, address_space(3)))
+# define __rcu __attribute__((noderef, address_space(4)))
+# define __private __attribute__((noderef))
+extern void __chk_user_ptr(const volatile void __user *);
+extern void __chk_io_ptr(const volatile void __iomem *);
+# define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member))
+#else /* __CHECKER__ */
+# ifdef STRUCTLEAK_PLUGIN
+# define __user __attribute__((user))
+# else
+# define __user
+# endif
+# define __kernel
+# define __safe
+# define __force
+# define __nocast
+# define __iomem
+# define __chk_user_ptr(x) (void)0
+# define __chk_io_ptr(x) (void)0
+# define __builtin_warning(x, y...) (1)
+# define __must_hold(x)
+# define __acquires(x)
+# define __releases(x)
+# define __acquire(x) (void)0
+# define __release(x) (void)0
+# define __cond_lock(x,c) (c)
+# define __percpu
+# define __rcu
+# define __private
+# define ACCESS_PRIVATE(p, member) ((p)->member)
+#endif /* __CHECKER__ */
+
+/* Indirect macros required for expanded argument pasting, eg. __LINE__. */
+#define ___PASTE(a,b) a##b
+#define __PASTE(a,b) ___PASTE(a,b)
+
+#ifdef __KERNEL__
+
+/* Attributes */
+#include <linux/compiler_attributes.h>
+
+/* Compiler specific macros. */
+#ifdef __clang__
+#include <linux/compiler-clang.h>
+#elif defined(__INTEL_COMPILER)
+#include <linux/compiler-intel.h>
+#elif defined(__GNUC__)
+/* The above compilers also define __GNUC__, so order is important here. */
+#include <linux/compiler-gcc.h>
+#else
+#error "Unknown compiler"
+#endif
+
+/*
+ * Some architectures need to provide custom definitions of macros provided
+ * by linux/compiler-*.h, and can do so using asm/compiler.h. We include that
+ * conditionally rather than using an asm-generic wrapper in order to avoid
+ * build failures if any C compilation, which will include this file via an
+ * -include argument in c_flags, occurs prior to the asm-generic wrappers being
+ * generated.
+ */
+#ifdef CONFIG_HAVE_ARCH_COMPILER_H
+#include <asm/compiler.h>
+#endif
+
+struct ftrace_branch_data {
+ const char *func;
+ const char *file;
+ unsigned line;
+ union {
+ struct {
+ unsigned long correct;
+ unsigned long incorrect;
+ };
+ struct {
+ unsigned long miss;
+ unsigned long hit;
+ };
+ unsigned long miss_hit[2];
+ };
+};
+
+struct ftrace_likely_data {
+ struct ftrace_branch_data data;
+ unsigned long constant;
+};
+
+#ifdef CONFIG_ENABLE_MUST_CHECK
+#define __must_check __attribute__((__warn_unused_result__))
+#else
+#define __must_check
+#endif
+
+#if defined(CC_USING_HOTPATCH)
+#define notrace __attribute__((hotpatch(0, 0)))
+#elif defined(CC_USING_PATCHABLE_FUNCTION_ENTRY)
+#define notrace __attribute__((patchable_function_entry(0, 0)))
+#else
+#define notrace __attribute__((__no_instrument_function__))
+#endif
+
+/*
+ * it doesn't make sense on ARM (currently the only user of __naked)
+ * to trace naked functions because then mcount is called without
+ * stack and frame pointer being set up and there is no chance to
+ * restore the lr register to the value before mcount was called.
+ */
+#define __naked __attribute__((__naked__)) notrace
+
+#define __compiler_offsetof(a, b) __builtin_offsetof(a, b)
+
+/*
+ * Force always-inline if the user requests it so via the .config.
+ * Prefer gnu_inline, so that extern inline functions do not emit an
+ * externally visible function. This makes extern inline behave as per gnu89
+ * semantics rather than c99. This prevents multiple symbol definition errors
+ * of extern inline functions at link time.
+ * A lot of inline functions can cause havoc with function tracing.
+ * Do not use __always_inline here, since currently it expands to inline again
+ * (which would break users of __always_inline).
+ */
+#if !defined(CONFIG_OPTIMIZE_INLINING)
+#define inline inline __attribute__((__always_inline__)) __gnu_inline \
+ __inline_maybe_unused notrace
+#else
+#define inline inline __gnu_inline \
+ __inline_maybe_unused notrace
+#endif
+
+/*
+ * gcc provides both __inline__ and __inline as alternate spellings of
+ * the inline keyword, though the latter is undocumented. New kernel
+ * code should only use the inline spelling, but some existing code
+ * uses __inline__. Since we #define inline above, to ensure
+ * __inline__ has the same semantics, we need this #define.
+ *
+ * However, the spelling __inline is strictly reserved for referring
+ * to the bare keyword.
+ */
+#define __inline__ inline
+
+/*
+ * GCC does not warn about unused static inline functions for -Wunused-function.
+ * Suppress the warning in clang as well by using __maybe_unused, but enable it
+ * for W=1 build. This will allow clang to find unused functions. Remove the
+ * __inline_maybe_unused entirely after fixing most of -Wunused-function warnings.
+ */
+#ifdef KBUILD_EXTRA_WARN1
+#define __inline_maybe_unused
+#else
+#define __inline_maybe_unused __maybe_unused
+#endif
+
+/*
+ * Rather then using noinline to prevent stack consumption, use
+ * noinline_for_stack instead. For documentation reasons.
+ */
+#define noinline_for_stack noinline
+
+#endif /* __KERNEL__ */
+
+#endif /* __ASSEMBLY__ */
+
+/*
+ * The below symbols may be defined for one or more, but not ALL, of the above
+ * compilers. We don't consider that to be an error, so set them to nothing.
+ * For example, some of them are for compiler specific plugins.
+ */
+#ifndef __latent_entropy
+# define __latent_entropy
+#endif
+
+#ifndef __randomize_layout
+# define __randomize_layout __designated_init
+#endif
+
+#ifndef __no_randomize_layout
+# define __no_randomize_layout
+#endif
+
+#ifndef randomized_struct_fields_start
+# define randomized_struct_fields_start
+# define randomized_struct_fields_end
+#endif
+
+#ifndef asm_volatile_goto
+#define asm_volatile_goto(x...) asm goto(x)
+#endif
+
+#ifdef CONFIG_CC_HAS_ASM_INLINE
+#define asm_inline asm __inline
+#else
+#define asm_inline asm
+#endif
+
+#ifndef __no_fgcse
+# define __no_fgcse
+#endif
+
+/* Are two types/vars the same type (ignoring qualifiers)? */
+#define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
+
+/* Is this type a native word size -- useful for atomic operations */
+#define __native_word(t) \
+ (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || \
+ sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
+
+/* Helpers for emitting diagnostics in pragmas. */
+#ifndef __diag
+#define __diag(string)
+#endif
+
+#ifndef __diag_GCC
+#define __diag_GCC(version, severity, string)
+#endif
+
+#define __diag_push() __diag(push)
+#define __diag_pop() __diag(pop)
+
+#define __diag_ignore(compiler, version, option, comment) \
+ __diag_ ## compiler(version, ignore, option)
+#define __diag_warn(compiler, version, option, comment) \
+ __diag_ ## compiler(version, warn, option)
+#define __diag_error(compiler, version, option, comment) \
+ __diag_ ## compiler(version, error, option)
+
+#endif /* __LINUX_COMPILER_TYPES_H */
diff --git a/include/linux/if.h b/include/linux/if.h
new file mode 100644
index 000000000..a8ccf6d17
--- /dev/null
+++ b/include/linux/if.h
@@ -0,0 +1,296 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * INET An implementation of the TCP/IP protocol suite for the LINUX
+ * operating system. INET is implemented using the BSD Socket
+ * interface as the means of communication with the user level.
+ *
+ * Global definitions for the INET interface module.
+ *
+ * Version: @(#)if.h 1.0.2 04/18/93
+ *
+ * Authors: Original taken from Berkeley UNIX 4.3, (c) UCB 1982-1988
+ * Ross Biro
+ * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#ifndef _LINUX_IF_H
+#define _LINUX_IF_H
+
+#include <linux/libc-compat.h> /* for compatibility with glibc */
+#include <linux/types.h> /* for "__kernel_caddr_t" et al */
+#include <linux/socket.h> /* for "struct sockaddr" et al */
+#include <linux/compiler_types.h> /* for "__user" et al */
+
+#ifndef __KERNEL__
+#include <sys/socket.h> /* for struct sockaddr. */
+#endif
+
+#if __UAPI_DEF_IF_IFNAMSIZ
+#define IFNAMSIZ 16
+#endif /* __UAPI_DEF_IF_IFNAMSIZ */
+#define IFALIASZ 256
+#define ALTIFNAMSIZ 128
+#include <linux/hdlc/ioctl.h>
+
+/* For glibc compatibility. An empty enum does not compile. */
+#if __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO != 0 || \
+ __UAPI_DEF_IF_NET_DEVICE_FLAGS != 0
+/**
+ * enum net_device_flags - &struct net_device flags
+ *
+ * These are the &struct net_device flags, they can be set by drivers, the
+ * kernel and some can be triggered by userspace. Userspace can query and
+ * set these flags using userspace utilities but there is also a sysfs
+ * entry available for all dev flags which can be queried and set. These flags
+ * are shared for all types of net_devices. The sysfs entries are available
+ * via /sys/class/net/<dev>/flags. Flags which can be toggled through sysfs
+ * are annotated below, note that only a few flags can be toggled and some
+ * other flags are always preserved from the original net_device flags
+ * even if you try to set them via sysfs. Flags which are always preserved
+ * are kept under the flag grouping @IFF_VOLATILE. Flags which are volatile
+ * are annotated below as such.
+ *
+ * You should have a pretty good reason to be extending these flags.
+ *
+ * @IFF_UP: interface is up. Can be toggled through sysfs.
+ * @IFF_BROADCAST: broadcast address valid. Volatile.
+ * @IFF_DEBUG: turn on debugging. Can be toggled through sysfs.
+ * @IFF_LOOPBACK: is a loopback net. Volatile.
+ * @IFF_POINTOPOINT: interface is has p-p link. Volatile.
+ * @IFF_NOTRAILERS: avoid use of trailers. Can be toggled through sysfs.
+ * Volatile.
+ * @IFF_RUNNING: interface RFC2863 OPER_UP. Volatile.
+ * @IFF_NOARP: no ARP protocol. Can be toggled through sysfs. Volatile.
+ * @IFF_PROMISC: receive all packets. Can be toggled through sysfs.
+ * @IFF_ALLMULTI: receive all multicast packets. Can be toggled through
+ * sysfs.
+ * @IFF_MASTER: master of a load balancer. Volatile.
+ * @IFF_SLAVE: slave of a load balancer. Volatile.
+ * @IFF_MULTICAST: Supports multicast. Can be toggled through sysfs.
+ * @IFF_PORTSEL: can set media type. Can be toggled through sysfs.
+ * @IFF_AUTOMEDIA: auto media select active. Can be toggled through sysfs.
+ * @IFF_DYNAMIC: dialup device with changing addresses. Can be toggled
+ * through sysfs.
+ * @IFF_LOWER_UP: driver signals L1 up. Volatile.
+ * @IFF_DORMANT: driver signals dormant. Volatile.
+ * @IFF_ECHO: echo sent packets. Volatile.
+ */
+enum net_device_flags {
+/* for compatibility with glibc net/if.h */
+#if __UAPI_DEF_IF_NET_DEVICE_FLAGS
+ IFF_UP = 1<<0, /* sysfs */
+ IFF_BROADCAST = 1<<1, /* volatile */
+ IFF_DEBUG = 1<<2, /* sysfs */
+ IFF_LOOPBACK = 1<<3, /* volatile */
+ IFF_POINTOPOINT = 1<<4, /* volatile */
+ IFF_NOTRAILERS = 1<<5, /* sysfs */
+ IFF_RUNNING = 1<<6, /* volatile */
+ IFF_NOARP = 1<<7, /* sysfs */
+ IFF_PROMISC = 1<<8, /* sysfs */
+ IFF_ALLMULTI = 1<<9, /* sysfs */
+ IFF_MASTER = 1<<10, /* volatile */
+ IFF_SLAVE = 1<<11, /* volatile */
+ IFF_MULTICAST = 1<<12, /* sysfs */
+ IFF_PORTSEL = 1<<13, /* sysfs */
+ IFF_AUTOMEDIA = 1<<14, /* sysfs */
+ IFF_DYNAMIC = 1<<15, /* sysfs */
+#endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS */
+#if __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO
+ IFF_LOWER_UP = 1<<16, /* volatile */
+ IFF_DORMANT = 1<<17, /* volatile */
+ IFF_ECHO = 1<<18, /* volatile */
+#endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO */
+};
+#endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO != 0 || __UAPI_DEF_IF_NET_DEVICE_FLAGS != 0 */
+
+/* for compatibility with glibc net/if.h */
+#if __UAPI_DEF_IF_NET_DEVICE_FLAGS
+#define IFF_UP IFF_UP
+#define IFF_BROADCAST IFF_BROADCAST
+#define IFF_DEBUG IFF_DEBUG
+#define IFF_LOOPBACK IFF_LOOPBACK
+#define IFF_POINTOPOINT IFF_POINTOPOINT
+#define IFF_NOTRAILERS IFF_NOTRAILERS
+#define IFF_RUNNING IFF_RUNNING
+#define IFF_NOARP IFF_NOARP
+#define IFF_PROMISC IFF_PROMISC
+#define IFF_ALLMULTI IFF_ALLMULTI
+#define IFF_MASTER IFF_MASTER
+#define IFF_SLAVE IFF_SLAVE
+#define IFF_MULTICAST IFF_MULTICAST
+#define IFF_PORTSEL IFF_PORTSEL
+#define IFF_AUTOMEDIA IFF_AUTOMEDIA
+#define IFF_DYNAMIC IFF_DYNAMIC
+#endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS */
+
+#if __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO
+#define IFF_LOWER_UP IFF_LOWER_UP
+#define IFF_DORMANT IFF_DORMANT
+#define IFF_ECHO IFF_ECHO
+#endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO */
+
+#define IFF_VOLATILE (IFF_LOOPBACK|IFF_POINTOPOINT|IFF_BROADCAST|IFF_ECHO|\
+ IFF_MASTER|IFF_SLAVE|IFF_RUNNING|IFF_LOWER_UP|IFF_DORMANT)
+
+#define IF_GET_IFACE 0x0001 /* for querying only */
+#define IF_GET_PROTO 0x0002
+
+/* For definitions see hdlc.h */
+#define IF_IFACE_V35 0x1000 /* V.35 serial interface */
+#define IF_IFACE_V24 0x1001 /* V.24 serial interface */
+#define IF_IFACE_X21 0x1002 /* X.21 serial interface */
+#define IF_IFACE_T1 0x1003 /* T1 telco serial interface */
+#define IF_IFACE_E1 0x1004 /* E1 telco serial interface */
+#define IF_IFACE_SYNC_SERIAL 0x1005 /* can't be set by software */
+#define IF_IFACE_X21D 0x1006 /* X.21 Dual Clocking (FarSite) */
+
+/* For definitions see hdlc.h */
+#define IF_PROTO_HDLC 0x2000 /* raw HDLC protocol */
+#define IF_PROTO_PPP 0x2001 /* PPP protocol */
+#define IF_PROTO_CISCO 0x2002 /* Cisco HDLC protocol */
+#define IF_PROTO_FR 0x2003 /* Frame Relay protocol */
+#define IF_PROTO_FR_ADD_PVC 0x2004 /* Create FR PVC */
+#define IF_PROTO_FR_DEL_PVC 0x2005 /* Delete FR PVC */
+#define IF_PROTO_X25 0x2006 /* X.25 */
+#define IF_PROTO_HDLC_ETH 0x2007 /* raw HDLC, Ethernet emulation */
+#define IF_PROTO_FR_ADD_ETH_PVC 0x2008 /* Create FR Ethernet-bridged PVC */
+#define IF_PROTO_FR_DEL_ETH_PVC 0x2009 /* Delete FR Ethernet-bridged PVC */
+#define IF_PROTO_FR_PVC 0x200A /* for reading PVC status */
+#define IF_PROTO_FR_ETH_PVC 0x200B
+#define IF_PROTO_RAW 0x200C /* RAW Socket */
+
+/* RFC 2863 operational status */
+enum {
+ IF_OPER_UNKNOWN,
+ IF_OPER_NOTPRESENT,
+ IF_OPER_DOWN,
+ IF_OPER_LOWERLAYERDOWN,
+ IF_OPER_TESTING,
+ IF_OPER_DORMANT,
+ IF_OPER_UP,
+};
+
+/* link modes */
+enum {
+ IF_LINK_MODE_DEFAULT,
+ IF_LINK_MODE_DORMANT, /* limit upward transition to dormant */
+};
+
+/*
+ * Device mapping structure. I'd just gone off and designed a
+ * beautiful scheme using only loadable modules with arguments
+ * for driver options and along come the PCMCIA people 8)
+ *
+ * Ah well. The get() side of this is good for WDSETUP, and it'll
+ * be handy for debugging things. The set side is fine for now and
+ * being very small might be worth keeping for clean configuration.
+ */
+
+/* for compatibility with glibc net/if.h */
+#if __UAPI_DEF_IF_IFMAP
+struct ifmap {
+ unsigned long mem_start;
+ unsigned long mem_end;
+ unsigned short base_addr;
+ unsigned char irq;
+ unsigned char dma;
+ unsigned char port;
+ /* 3 bytes spare */
+};
+#endif /* __UAPI_DEF_IF_IFMAP */
+
+struct if_settings {
+ unsigned int type; /* Type of physical device or protocol */
+ unsigned int size; /* Size of the data allocated by the caller */
+ union {
+ /* {atm/eth/dsl}_settings anyone ? */
+ raw_hdlc_proto __user *raw_hdlc;
+ cisco_proto __user *cisco;
+ fr_proto __user *fr;
+ fr_proto_pvc __user *fr_pvc;
+ fr_proto_pvc_info __user *fr_pvc_info;
+
+ /* interface settings */
+ sync_serial_settings __user *sync;
+ te1_settings __user *te1;
+ } ifs_ifsu;
+};
+
+/*
+ * Interface request structure used for socket
+ * ioctl's. All interface ioctl's must have parameter
+ * definitions which begin with ifr_name. The
+ * remainder may be interface specific.
+ */
+
+/* for compatibility with glibc net/if.h */
+#if __UAPI_DEF_IF_IFREQ
+struct ifreq {
+#define IFHWADDRLEN 6
+ union
+ {
+ char ifrn_name[IFNAMSIZ]; /* if name, e.g. "en0" */
+ } ifr_ifrn;
+
+ union {
+ struct sockaddr ifru_addr;
+ struct sockaddr ifru_dstaddr;
+ struct sockaddr ifru_broadaddr;
+ struct sockaddr ifru_netmask;
+ struct sockaddr ifru_hwaddr;
+ short ifru_flags;
+ int ifru_ivalue;
+ int ifru_mtu;
+ struct ifmap ifru_map;
+ char ifru_slave[IFNAMSIZ]; /* Just fits the size */
+ char ifru_newname[IFNAMSIZ];
+ void __user * ifru_data;
+ struct if_settings ifru_settings;
+ } ifr_ifru;
+};
+#endif /* __UAPI_DEF_IF_IFREQ */
+
+#define ifr_name ifr_ifrn.ifrn_name /* interface name */
+#define ifr_hwaddr ifr_ifru.ifru_hwaddr /* MAC address */
+#define ifr_addr ifr_ifru.ifru_addr /* address */
+#define ifr_dstaddr ifr_ifru.ifru_dstaddr /* other end of p-p lnk */
+#define ifr_broadaddr ifr_ifru.ifru_broadaddr /* broadcast address */
+#define ifr_netmask ifr_ifru.ifru_netmask /* interface net mask */
+#define ifr_flags ifr_ifru.ifru_flags /* flags */
+#define ifr_metric ifr_ifru.ifru_ivalue /* metric */
+#define ifr_mtu ifr_ifru.ifru_mtu /* mtu */
+#define ifr_map ifr_ifru.ifru_map /* device map */
+#define ifr_slave ifr_ifru.ifru_slave /* slave device */
+#define ifr_data ifr_ifru.ifru_data /* for use by interface */
+#define ifr_ifindex ifr_ifru.ifru_ivalue /* interface index */
+#define ifr_bandwidth ifr_ifru.ifru_ivalue /* link bandwidth */
+#define ifr_qlen ifr_ifru.ifru_ivalue /* Queue length */
+#define ifr_newname ifr_ifru.ifru_newname /* New name */
+#define ifr_settings ifr_ifru.ifru_settings /* Device/proto settings*/
+
+/*
+ * Structure used in SIOCGIFCONF request.
+ * Used to retrieve interface configuration
+ * for machine (useful for programs which
+ * must know all networks accessible).
+ */
+
+/* for compatibility with glibc net/if.h */
+#if __UAPI_DEF_IF_IFCONF
+struct ifconf {
+ int ifc_len; /* size of buffer */
+ union {
+ char __user *ifcu_buf;
+ struct ifreq __user *ifcu_req;
+ } ifc_ifcu;
+};
+#endif /* __UAPI_DEF_IF_IFCONF */
+
+#define ifc_buf ifc_ifcu.ifcu_buf /* buffer address */
+#define ifc_req ifc_ifcu.ifcu_req /* array of structures */
+
+#endif /* _LINUX_IF_H */
diff --git a/include/linux/libc-compat.h b/include/linux/libc-compat.h
new file mode 100644
index 000000000..8254c937c
--- /dev/null
+++ b/include/linux/libc-compat.h
@@ -0,0 +1,267 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Compatibility interface for userspace libc header coordination:
+ *
+ * Define compatibility macros that are used to control the inclusion or
+ * exclusion of UAPI structures and definitions in coordination with another
+ * userspace C library.
+ *
+ * This header is intended to solve the problem of UAPI definitions that
+ * conflict with userspace definitions. If a UAPI header has such conflicting
+ * definitions then the solution is as follows:
+ *
+ * * Synchronize the UAPI header and the libc headers so either one can be
+ * used and such that the ABI is preserved. If this is not possible then
+ * no simple compatibility interface exists (you need to write translating
+ * wrappers and rename things) and you can't use this interface.
+ *
+ * Then follow this process:
+ *
+ * (a) Include libc-compat.h in the UAPI header.
+ * e.g. #include <linux/libc-compat.h>
+ * This include must be as early as possible.
+ *
+ * (b) In libc-compat.h add enough code to detect that the comflicting
+ * userspace libc header has been included first.
+ *
+ * (c) If the userspace libc header has been included first define a set of
+ * guard macros of the form __UAPI_DEF_FOO and set their values to 1, else
+ * set their values to 0.
+ *
+ * (d) Back in the UAPI header with the conflicting definitions, guard the
+ * definitions with:
+ * #if __UAPI_DEF_FOO
+ * ...
+ * #endif
+ *
+ * This fixes the situation where the linux headers are included *after* the
+ * libc headers. To fix the problem with the inclusion in the other order the
+ * userspace libc headers must be fixed like this:
+ *
+ * * For all definitions that conflict with kernel definitions wrap those
+ * defines in the following:
+ * #if !__UAPI_DEF_FOO
+ * ...
+ * #endif
+ *
+ * This prevents the redefinition of a construct already defined by the kernel.
+ */
+#ifndef _UAPI_LIBC_COMPAT_H
+#define _UAPI_LIBC_COMPAT_H
+
+/* We have included glibc headers... */
+#if defined(__GLIBC__)
+
+/* Coordinate with glibc net/if.h header. */
+#if defined(_NET_IF_H) && defined(__USE_MISC)
+
+/* GLIBC headers included first so don't define anything
+ * that would already be defined. */
+
+#define __UAPI_DEF_IF_IFCONF 0
+#define __UAPI_DEF_IF_IFMAP 0
+#define __UAPI_DEF_IF_IFNAMSIZ 0
+#define __UAPI_DEF_IF_IFREQ 0
+/* Everything up to IFF_DYNAMIC, matches net/if.h until glibc 2.23 */
+#define __UAPI_DEF_IF_NET_DEVICE_FLAGS 0
+/* For the future if glibc adds IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO */
+#ifndef __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO
+#define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 1
+#endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO */
+
+#else /* _NET_IF_H */
+
+/* Linux headers included first, and we must define everything
+ * we need. The expectation is that glibc will check the
+ * __UAPI_DEF_* defines and adjust appropriately. */
+
+#define __UAPI_DEF_IF_IFCONF 1
+#define __UAPI_DEF_IF_IFMAP 1
+#define __UAPI_DEF_IF_IFNAMSIZ 1
+#define __UAPI_DEF_IF_IFREQ 1
+/* Everything up to IFF_DYNAMIC, matches net/if.h until glibc 2.23 */
+#define __UAPI_DEF_IF_NET_DEVICE_FLAGS 1
+/* For the future if glibc adds IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO */
+#define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 1
+
+#endif /* _NET_IF_H */
+
+/* Coordinate with glibc netinet/in.h header. */
+#if defined(_NETINET_IN_H)
+
+/* GLIBC headers included first so don't define anything
+ * that would already be defined. */
+#define __UAPI_DEF_IN_ADDR 0
+#define __UAPI_DEF_IN_IPPROTO 0
+#define __UAPI_DEF_IN_PKTINFO 0
+#define __UAPI_DEF_IP_MREQ 0
+#define __UAPI_DEF_SOCKADDR_IN 0
+#define __UAPI_DEF_IN_CLASS 0
+
+#define __UAPI_DEF_IN6_ADDR 0
+/* The exception is the in6_addr macros which must be defined
+ * if the glibc code didn't define them. This guard matches
+ * the guard in glibc/inet/netinet/in.h which defines the
+ * additional in6_addr macros e.g. s6_addr16, and s6_addr32. */
+#if defined(__USE_MISC) || defined (__USE_GNU)
+#define __UAPI_DEF_IN6_ADDR_ALT 0
+#else
+#define __UAPI_DEF_IN6_ADDR_ALT 1
+#endif
+#define __UAPI_DEF_SOCKADDR_IN6 0
+#define __UAPI_DEF_IPV6_MREQ 0
+#define __UAPI_DEF_IPPROTO_V6 0
+#define __UAPI_DEF_IPV6_OPTIONS 0
+#define __UAPI_DEF_IN6_PKTINFO 0
+#define __UAPI_DEF_IP6_MTUINFO 0
+
+#else
+
+/* Linux headers included first, and we must define everything
+ * we need. The expectation is that glibc will check the
+ * __UAPI_DEF_* defines and adjust appropriately. */
+#define __UAPI_DEF_IN_ADDR 1
+#define __UAPI_DEF_IN_IPPROTO 1
+#define __UAPI_DEF_IN_PKTINFO 1
+#define __UAPI_DEF_IP_MREQ 1
+#define __UAPI_DEF_SOCKADDR_IN 1
+#define __UAPI_DEF_IN_CLASS 1
+
+#define __UAPI_DEF_IN6_ADDR 1
+/* We unconditionally define the in6_addr macros and glibc must
+ * coordinate. */
+#define __UAPI_DEF_IN6_ADDR_ALT 1
+#define __UAPI_DEF_SOCKADDR_IN6 1
+#define __UAPI_DEF_IPV6_MREQ 1
+#define __UAPI_DEF_IPPROTO_V6 1
+#define __UAPI_DEF_IPV6_OPTIONS 1
+#define __UAPI_DEF_IN6_PKTINFO 1
+#define __UAPI_DEF_IP6_MTUINFO 1
+
+#endif /* _NETINET_IN_H */
+
+/* Coordinate with glibc netipx/ipx.h header. */
+#if defined(__NETIPX_IPX_H)
+
+#define __UAPI_DEF_SOCKADDR_IPX 0
+#define __UAPI_DEF_IPX_ROUTE_DEFINITION 0
+#define __UAPI_DEF_IPX_INTERFACE_DEFINITION 0
+#define __UAPI_DEF_IPX_CONFIG_DATA 0
+#define __UAPI_DEF_IPX_ROUTE_DEF 0
+
+#else /* defined(__NETIPX_IPX_H) */
+
+#define __UAPI_DEF_SOCKADDR_IPX 1
+#define __UAPI_DEF_IPX_ROUTE_DEFINITION 1
+#define __UAPI_DEF_IPX_INTERFACE_DEFINITION 1
+#define __UAPI_DEF_IPX_CONFIG_DATA 1
+#define __UAPI_DEF_IPX_ROUTE_DEF 1
+
+#endif /* defined(__NETIPX_IPX_H) */
+
+/* Definitions for xattr.h */
+#if defined(_SYS_XATTR_H)
+#define __UAPI_DEF_XATTR 0
+#else
+#define __UAPI_DEF_XATTR 1
+#endif
+
+/* If we did not see any headers from any supported C libraries,
+ * or we are being included in the kernel, then define everything
+ * that we need. Check for previous __UAPI_* definitions to give
+ * unsupported C libraries a way to opt out of any kernel definition. */
+#else /* !defined(__GLIBC__) */
+
+/* Definitions for if.h */
+#ifndef __UAPI_DEF_IF_IFCONF
+#define __UAPI_DEF_IF_IFCONF 1
+#endif
+#ifndef __UAPI_DEF_IF_IFMAP
+#define __UAPI_DEF_IF_IFMAP 1
+#endif
+#ifndef __UAPI_DEF_IF_IFNAMSIZ
+#define __UAPI_DEF_IF_IFNAMSIZ 1
+#endif
+#ifndef __UAPI_DEF_IF_IFREQ
+#define __UAPI_DEF_IF_IFREQ 1
+#endif
+/* Everything up to IFF_DYNAMIC, matches net/if.h until glibc 2.23 */
+#ifndef __UAPI_DEF_IF_NET_DEVICE_FLAGS
+#define __UAPI_DEF_IF_NET_DEVICE_FLAGS 1
+#endif
+/* For the future if glibc adds IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO */
+#ifndef __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO
+#define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 1
+#endif
+
+/* Definitions for in.h */
+#ifndef __UAPI_DEF_IN_ADDR
+#define __UAPI_DEF_IN_ADDR 1
+#endif
+#ifndef __UAPI_DEF_IN_IPPROTO
+#define __UAPI_DEF_IN_IPPROTO 1
+#endif
+#ifndef __UAPI_DEF_IN_PKTINFO
+#define __UAPI_DEF_IN_PKTINFO 1
+#endif
+#ifndef __UAPI_DEF_IP_MREQ
+#define __UAPI_DEF_IP_MREQ 1
+#endif
+#ifndef __UAPI_DEF_SOCKADDR_IN
+#define __UAPI_DEF_SOCKADDR_IN 1
+#endif
+#ifndef __UAPI_DEF_IN_CLASS
+#define __UAPI_DEF_IN_CLASS 1
+#endif
+
+/* Definitions for in6.h */
+#ifndef __UAPI_DEF_IN6_ADDR
+#define __UAPI_DEF_IN6_ADDR 1
+#endif
+#ifndef __UAPI_DEF_IN6_ADDR_ALT
+#define __UAPI_DEF_IN6_ADDR_ALT 1
+#endif
+#ifndef __UAPI_DEF_SOCKADDR_IN6
+#define __UAPI_DEF_SOCKADDR_IN6 1
+#endif
+#ifndef __UAPI_DEF_IPV6_MREQ
+#define __UAPI_DEF_IPV6_MREQ 1
+#endif
+#ifndef __UAPI_DEF_IPPROTO_V6
+#define __UAPI_DEF_IPPROTO_V6 1
+#endif
+#ifndef __UAPI_DEF_IPV6_OPTIONS
+#define __UAPI_DEF_IPV6_OPTIONS 1
+#endif
+#ifndef __UAPI_DEF_IN6_PKTINFO
+#define __UAPI_DEF_IN6_PKTINFO 1
+#endif
+#ifndef __UAPI_DEF_IP6_MTUINFO
+#define __UAPI_DEF_IP6_MTUINFO 1
+#endif
+
+/* Definitions for ipx.h */
+#ifndef __UAPI_DEF_SOCKADDR_IPX
+#define __UAPI_DEF_SOCKADDR_IPX 1
+#endif
+#ifndef __UAPI_DEF_IPX_ROUTE_DEFINITION
+#define __UAPI_DEF_IPX_ROUTE_DEFINITION 1
+#endif
+#ifndef __UAPI_DEF_IPX_INTERFACE_DEFINITION
+#define __UAPI_DEF_IPX_INTERFACE_DEFINITION 1
+#endif
+#ifndef __UAPI_DEF_IPX_CONFIG_DATA
+#define __UAPI_DEF_IPX_CONFIG_DATA 1
+#endif
+#ifndef __UAPI_DEF_IPX_ROUTE_DEF
+#define __UAPI_DEF_IPX_ROUTE_DEF 1
+#endif
+
+/* Definitions for xattr.h */
+#ifndef __UAPI_DEF_XATTR
+#define __UAPI_DEF_XATTR 1
+#endif
+
+#endif /* __GLIBC__ */
+
+#endif /* _UAPI_LIBC_COMPAT_H */