File /code/usr/include/linux/byteorder/generic.h

#ifndef _LINUX_BYTEORDER_GENERIC_H
#define _LINUX_BYTEORDER_GENERIC_H



/*
 * The following macros are to be defined by <asm/byteorder.h>:
 *
 * Conversion of long and short int between network and host format
 *	ntohl(__u32 x)
 *	ntohs(__u16 x)
 *	htonl(__u32 x)
 *	htons(__u16 x)
 * It seems that some programs (which? where? or perhaps a standard? POSIX?)
 * might like the above to be functions, not macros (why?).
 * if that's true, then detect them, and take measures.
 * Anyway, the measure is: define only ___ntohl as a macro instead,
 * and in a separate file, have
 * unsigned long inline ntohl(x){return ___ntohl(x);}
 *
 * The same for constant arguments
 *	__constant_ntohl(__u32 x)
 *	__constant_ntohs(__u16 x)
 *	__constant_htonl(__u32 x)
 *	__constant_htons(__u16 x)
 *
 * Conversion of XX-bit integers (16- 32- or 64-)
 * between native CPU format and little/big endian format
 * 64-bit stuff only defined for proper architectures
 *	cpu_to_[bl]eXX(__uXX x)
 *	[bl]eXX_to_cpu(__uXX x)
 *
 * The same, but takes a pointer to the value to convert
 *	cpu_to_[bl]eXXp(__uXX x)
 *	[bl]eXX_to_cpup(__uXX x)
 *
 * The same, but change in situ
 *	cpu_to_[bl]eXXs(__uXX x)
 *	[bl]eXX_to_cpus(__uXX x)
 *
 * See asm-foo/byteorder.h for examples of how to provide
 * architecture-optimized versions
 *
 */


#if defined(__KERNEL__)
/*
 * inside the kernel, we can use nicknames;
 * outside of it, we must avoid POSIX namespace pollution...
 */
#define cpu_to_le64 __cpu_to_le64
#define le64_to_cpu __le64_to_cpu
#define cpu_to_le32 __cpu_to_le32
#define le32_to_cpu __le32_to_cpu
#define cpu_to_le16 __cpu_to_le16
#define le16_to_cpu __le16_to_cpu
#define cpu_to_be64 __cpu_to_be64
#define be64_to_cpu __be64_to_cpu
#define cpu_to_be32 __cpu_to_be32
#define be32_to_cpu __be32_to_cpu
#define cpu_to_be16 __cpu_to_be16
#define be16_to_cpu __be16_to_cpu
#define cpu_to_le64p __cpu_to_le64p
#define le64_to_cpup __le64_to_cpup
#define cpu_to_le32p __cpu_to_le32p
#define le32_to_cpup __le32_to_cpup
#define cpu_to_le16p __cpu_to_le16p
#define le16_to_cpup __le16_to_cpup
#define cpu_to_be64p __cpu_to_be64p
#define be64_to_cpup __be64_to_cpup
#define cpu_to_be32p __cpu_to_be32p
#define be32_to_cpup __be32_to_cpup
#define cpu_to_be16p __cpu_to_be16p
#define be16_to_cpup __be16_to_cpup
#define cpu_to_le64s __cpu_to_le64s
#define le64_to_cpus __le64_to_cpus
#define cpu_to_le32s __cpu_to_le32s
#define le32_to_cpus __le32_to_cpus
#define cpu_to_le16s __cpu_to_le16s
#define le16_to_cpus __le16_to_cpus
#define cpu_to_be64s __cpu_to_be64s
#define be64_to_cpus __be64_to_cpus
#define cpu_to_be32s __cpu_to_be32s
#define be32_to_cpus __be32_to_cpus
#define cpu_to_be16s __cpu_to_be16s
#define be16_to_cpus __be16_to_cpus
#endif


/*
 * Handle ntohl and suches. These have various compatibility
 * issues - like we want to give the prototype even though we
 * also have a macro for them in case some strange program
 * wants to take the address of the thing or something..
 *
 * Note that these used to return a "long" in libc5, even though
 * long is often 64-bit these days.. Thus the casts.
 *
 * They have to be macros in order to do the constant folding
 * correctly - if the argument passed into a inline function
 * it is no longer constant according to gcc..
 */

#undef ntohl
#undef ntohs
#undef htonl
#undef htons

/*
 * Do the prototypes. Somebody might want to take the
 * address or some such sick thing..
 */
#if defined(__KERNEL__) || (defined (__GLIBC__) && __GLIBC__ >= 2)
extern __u32			ntohl(__u32);
extern __u32			htonl(__u32);
#else
extern unsigned long int	ntohl(unsigned long int);
extern unsigned long int	htonl(unsigned long int);
#endif
extern unsigned short int	ntohs(unsigned short int);
extern unsigned short int	htons(unsigned short int);


#if defined(__GNUC__) && (__GNUC__ >= 2) && defined(__OPTIMIZE__)

#define ___htonl(x) __cpu_to_be32(x)
#define ___htons(x) __cpu_to_be16(x)
#define ___ntohl(x) __be32_to_cpu(x)
#define ___ntohs(x) __be16_to_cpu(x)

#if defined(__KERNEL__) || (defined (__GLIBC__) && __GLIBC__ >= 2)
#define htonl(x) ___htonl(x)
#define ntohl(x) ___ntohl(x)
#else
#define htonl(x) ((unsigned long)___htonl(x))
#define ntohl(x) ((unsigned long)___ntohl(x))
#endif
#define htons(x) ___htons(x)
#define ntohs(x) ___ntohs(x)

#endif /* OPTIMIZE */


#endif /* _LINUX_BYTEORDER_GENERIC_H */