[thirdparty/glibc.git] / socket / sys / socket.h

/* Declarations of socket constants, types, and functions.
   Copyright (C) 1991-2025 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#ifndef	_SYS_SOCKET_H
#define	_SYS_SOCKET_H	1

#include <features.h>

__BEGIN_DECLS

#include <bits/types/struct_iovec.h>
#define	__need_size_t
#include <stddef.h>

/* This operating system-specific header file defines the SOCK_*, PF_*,
   AF_*, MSG_*, SOL_*, and SO_* constants, and the `struct sockaddr',
   `struct msghdr', and `struct linger' types.  */
#include <bits/socket.h>

#ifdef __USE_MISC
# include <bits/types/struct_osockaddr.h>
#endif

/* The following constants should be used for the second parameter of
   `shutdown'.  */
enum
{
  SHUT_RD = 0,		/* No more receptions.  */
#define SHUT_RD		SHUT_RD
  SHUT_WR,		/* No more transmissions.  */
#define SHUT_WR		SHUT_WR
  SHUT_RDWR		/* No more receptions or transmissions.  */
#define SHUT_RDWR	SHUT_RDWR
};

/* This is the type we use for generic socket address arguments.

   With GCC 2.7 and later, the funky union causes redeclarations or
   uses with any of the listed types to be allowed without complaint.
   G++ 2.7 does not support transparent unions so there we want the
   old-style declaration, too.  */
#if defined __cplusplus || !__GNUC_PREREQ (2, 7) || !defined __USE_GNU
# define __SOCKADDR_ARG		struct sockaddr *__restrict
# define __CONST_SOCKADDR_ARG	const struct sockaddr *
#else
/* Add more `struct sockaddr_AF' types here as necessary.
   These are all the ones I found on NetBSD and Linux.  */
# define __SOCKADDR_ALLTYPES \
  __SOCKADDR_ONETYPE (sockaddr) \
  __SOCKADDR_ONETYPE (sockaddr_at) \
  __SOCKADDR_ONETYPE (sockaddr_ax25) \
  __SOCKADDR_ONETYPE (sockaddr_dl) \
  __SOCKADDR_ONETYPE (sockaddr_eon) \
  __SOCKADDR_ONETYPE (sockaddr_in) \
  __SOCKADDR_ONETYPE (sockaddr_in6) \
  __SOCKADDR_ONETYPE (sockaddr_inarp) \
  __SOCKADDR_ONETYPE (sockaddr_ipx) \
  __SOCKADDR_ONETYPE (sockaddr_iso) \
  __SOCKADDR_ONETYPE (sockaddr_ns) \
  __SOCKADDR_ONETYPE (sockaddr_un) \
  __SOCKADDR_ONETYPE (sockaddr_x25)

# define __SOCKADDR_ONETYPE(type) struct type *__restrict __##type##__;
typedef union { __SOCKADDR_ALLTYPES
	      } __SOCKADDR_ARG __attribute__ ((__transparent_union__));
# undef __SOCKADDR_ONETYPE
# define __SOCKADDR_ONETYPE(type) const struct type *__restrict __##type##__;
typedef union { __SOCKADDR_ALLTYPES
	      } __CONST_SOCKADDR_ARG __attribute__ ((__transparent_union__));
# undef __SOCKADDR_ONETYPE
#endif

#ifdef __USE_GNU
/* For `recvmmsg' and `sendmmsg'.  */
struct mmsghdr
  {
    struct msghdr msg_hdr;	/* Actual message header.  */
    unsigned int msg_len;	/* Number of received or sent bytes for the
				   entry.  */
  };
#endif


/* Create a new socket of type TYPE in domain DOMAIN, using
   protocol PROTOCOL.  If PROTOCOL is zero, one is chosen automatically.
   Returns a file descriptor for the new socket, or -1 for errors.  */
extern int socket (int __domain, int __type, int __protocol) __THROW;

/* Create two new sockets, of type TYPE in domain DOMAIN and using
   protocol PROTOCOL, which are connected to each other, and put file
   descriptors for them in FDS[0] and FDS[1].  If PROTOCOL is zero,
   one will be chosen automatically.  Returns 0 on success, -1 for errors.  */
extern int socketpair (int __domain, int __type, int __protocol,
		       int __fds[2]) __THROW;

/* Give the socket FD the local address ADDR (which is LEN bytes long).  */
extern int bind (int __fd, __CONST_SOCKADDR_ARG __addr, socklen_t __len)
     __THROW;

/* Put the local address of FD into *ADDR and its length in *LEN.  */
extern int getsockname (int __fd, __SOCKADDR_ARG __addr,
			socklen_t *__restrict __len) __THROW;

/* Open a connection on socket FD to peer at ADDR (which LEN bytes long).
   For connectionless socket types, just set the default address to send to
   and the only address from which to accept transmissions.
   Return 0 on success, -1 for errors.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern int connect (int __fd, __CONST_SOCKADDR_ARG __addr, socklen_t __len);

/* Put the address of the peer connected to socket FD into *ADDR
   (which is *LEN bytes long), and its actual length into *LEN.  */
extern int getpeername (int __fd, __SOCKADDR_ARG __addr,
			socklen_t *__restrict __len) __THROW;


/* Send N bytes of BUF to socket FD.  Returns the number sent or -1.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern ssize_t send (int __fd, const void *__buf, size_t __n, int __flags);

/* Read N bytes into BUF from socket FD.
   Returns the number read or -1 for errors.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern ssize_t recv (int __fd, void *__buf, size_t __n, int __flags);

/* Send N bytes of BUF on socket FD to peer at address ADDR (which is
   ADDR_LEN bytes long).  Returns the number sent, or -1 for errors.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern ssize_t sendto (int __fd, const void *__buf, size_t __n,
		       int __flags, __CONST_SOCKADDR_ARG __addr,
		       socklen_t __addr_len);

/* Read N bytes into BUF through socket FD.
   If ADDR is not NULL, fill in *ADDR_LEN bytes of it with the address of
   the sender, and store the actual size of the address in *ADDR_LEN.
   Returns the number of bytes read or -1 for errors.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern ssize_t recvfrom (int __fd, void *__restrict __buf, size_t __n,
			 int __flags, __SOCKADDR_ARG __addr,
			 socklen_t *__restrict __addr_len);


/* Send a message described MESSAGE on socket FD.
   Returns the number of bytes sent, or -1 for errors.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
#ifndef __USE_TIME64_REDIRECTS
extern ssize_t sendmsg (int __fd, const struct msghdr *__message,
			int __flags);
#else
# ifdef __REDIRECT
extern ssize_t __REDIRECT (sendmsg, (int __fd, const struct msghdr *__message,
				     int __flags),
			   __sendmsg64);
# else
extern ssize_t __sendmsg64 (int __fd, const struct msghdr *__message,
			    int __flags);
#  define sendmsg __sendmsg64
# endif
#endif

#ifdef __USE_GNU
/* Send a VLEN messages as described by VMESSAGES to socket FD.
   Returns the number of datagrams successfully written or -1 for errors.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
# ifndef __USE_TIME64_REDIRECTS
extern int sendmmsg (int __fd, struct mmsghdr *__vmessages,
		     unsigned int __vlen, int __flags);
# else
#  ifdef __REDIRECT
extern int __REDIRECT (sendmmsg, (int __fd, struct mmsghdr *__vmessages,
				  unsigned int __vlen, int __flags),
		       __sendmmsg64);
#  else
extern int __sendmmsg64 (int __fd, struct mmsghdr *__vmessages,
			 unsigned int __vlen, int __flags);
#   define sendmmsg __sendmmsg64
#  endif
# endif	 /* __USE_TIME64_REDIRECTS */
#endif /* __USE_GNU */

/* Receive a message as described by MESSAGE from socket FD.
   Returns the number of bytes read or -1 for errors.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
#ifndef __USE_TIME64_REDIRECTS
extern ssize_t recvmsg (int __fd, struct msghdr *__message, int __flags);
#else
# ifdef __REDIRECT
extern ssize_t __REDIRECT (recvmsg,
			   (int __fd, struct msghdr *__message, int __flags),
			   __recvmsg64);
# else
extern ssize_t __recvmsg64 (int __fd, struct msghdr *__message, int __flags);
#  define recvmsg __recvmsg64
# endif
#endif

#ifdef __USE_GNU
/* Receive up to VLEN messages as described by VMESSAGES from socket FD.
   Returns the number of messages received or -1 for errors.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
# ifndef __USE_TIME64_REDIRECTS
extern int recvmmsg (int __fd, struct mmsghdr *__vmessages,
		     unsigned int __vlen, int __flags,
		     struct timespec *__tmo);
# else
#  ifdef __REDIRECT
extern int __REDIRECT (recvmmsg, (int __fd, struct mmsghdr *__vmessages,
                                  unsigned int __vlen, int __flags,
                                  struct timespec *__tmo),
                       __recvmmsg64);
#  else
#   define recvmmsg __recvmmsg64
#  endif
# endif
#endif


/* Put the current value for socket FD's option OPTNAME at protocol level LEVEL
   into OPTVAL (which is *OPTLEN bytes long), and set *OPTLEN to the value's
   actual length.  Returns 0 on success, -1 for errors.  */
#ifndef __USE_TIME64_REDIRECTS
extern int getsockopt (int __fd, int __level, int __optname,
		       void *__restrict __optval,
		       socklen_t *__restrict __optlen) __THROW;
#else
# ifdef __REDIRECT
extern int __REDIRECT_NTH (getsockopt,
			   (int __fd, int __level, int __optname,
			    void *__restrict __optval,
			    socklen_t *__restrict __optlen),
			   __getsockopt64);
# else
extern int __getsockopt64 (int __fd, int __level, int __optname,
			   void *__restrict __optval,
			   socklen_t *__restrict __optlen) __THROW;
#  define getsockopt __getsockopt64
# endif
#endif

/* Set socket FD's option OPTNAME at protocol level LEVEL
   to *OPTVAL (which is OPTLEN bytes long).
   Returns 0 on success, -1 for errors.  */
#ifndef __USE_TIME64_REDIRECTS
extern int setsockopt (int __fd, int __level, int __optname,
		       const void *__optval, socklen_t __optlen) __THROW;
#else
# ifdef __REDIRECT
extern int __REDIRECT_NTH (setsockopt,
			   (int __fd, int __level, int __optname,
			    const void *__optval, socklen_t __optlen),
			   __setsockopt64);
# else
extern int __setsockopt64 (int __fd, int __level, int __optname,
			   const void *__optval, socklen_t __optlen) __THROW;
#  define setsockopt __setsockopt64
# endif
#endif


/* Prepare to accept connections on socket FD.
   N connection requests will be queued before further requests are refused.
   Returns 0 on success, -1 for errors.  */
extern int listen (int __fd, int __n) __THROW;

/* Await a connection on socket FD.
   When a connection arrives, open a new socket to communicate with it,
   set *ADDR (which is *ADDR_LEN bytes long) to the address of the connecting
   peer and *ADDR_LEN to the address's actual length, and return the
   new socket's descriptor, or -1 for errors.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern int accept (int __fd, __SOCKADDR_ARG __addr,
		   socklen_t *__restrict __addr_len);

#ifdef __USE_GNU
/* Similar to 'accept' but takes an additional parameter to specify flags.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern int accept4 (int __fd, __SOCKADDR_ARG __addr,
		    socklen_t *__restrict __addr_len, int __flags);
#endif

/* Shut down all or part of the connection open on socket FD.
   HOW determines what to shut down:
     SHUT_RD   = No more receptions;
     SHUT_WR   = No more transmissions;
     SHUT_RDWR = No more receptions or transmissions.
   Returns 0 on success, -1 for errors.  */
extern int shutdown (int __fd, int __how) __THROW;


#ifdef __USE_XOPEN2K
/* Determine whether socket is at a out-of-band mark.  */
extern int sockatmark (int __fd) __THROW;
#endif


#ifdef __USE_MISC
/* FDTYPE is S_IFSOCK or another S_IF* macro defined in <sys/stat.h>;
   returns 1 if FD is open on an object of the indicated type, 0 if not,
   or -1 for errors (setting errno).  */
extern int isfdtype (int __fd, int __fdtype) __THROW;
#endif


/* Define some macros helping to catch buffer overflows.  */
#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
# include <bits/socket2.h>
#endif

__END_DECLS

#endif /* sys/socket.h */
Commit	Line	Data
	1	/* Declarations of socket constants, types, and functions.
	2	Copyright (C) 1991-2025 Free Software Foundation, Inc.
	3	This file is part of the GNU C Library.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
	16	License along with the GNU C Library; if not, see
	17	<https://www.gnu.org/licenses/>. */
	18
	19	#ifndef _SYS_SOCKET_H
	20	#define _SYS_SOCKET_H 1
	21
	22	#include <features.h>
	23
	24	__BEGIN_DECLS
	25
	26	#include <bits/types/struct_iovec.h>
	27	#define __need_size_t
	28	#include <stddef.h>
	29
	30	/* This operating system-specific header file defines the SOCK_, PF_,
	31	AF_, MSG_, SOL_, and SO_ constants, and the `struct sockaddr',
	32	`struct msghdr', and `struct linger' types. */
	33	#include <bits/socket.h>
	34
	35	#ifdef __USE_MISC
	36	# include <bits/types/struct_osockaddr.h>
	37	#endif
	38
	39	/* The following constants should be used for the second parameter of
	40	`shutdown'. */
	41	enum
	42	{
	43	SHUT_RD = 0, /* No more receptions. */
	44	#define SHUT_RD SHUT_RD
	45	SHUT_WR, /* No more transmissions. */
	46	#define SHUT_WR SHUT_WR
	47	SHUT_RDWR /* No more receptions or transmissions. */
	48	#define SHUT_RDWR SHUT_RDWR
	49	};
	50
	51	/* This is the type we use for generic socket address arguments.
	52
	53	With GCC 2.7 and later, the funky union causes redeclarations or
	54	uses with any of the listed types to be allowed without complaint.
	55	G++ 2.7 does not support transparent unions so there we want the
	56	old-style declaration, too. */
	57	#if defined __cplusplus \|\| !__GNUC_PREREQ (2, 7) \|\| !defined __USE_GNU
	58	# define __SOCKADDR_ARG struct sockaddr *__restrict
	59	# define __CONST_SOCKADDR_ARG const struct sockaddr *
	60	#else
	61	/* Add more `struct sockaddr_AF' types here as necessary.
	62	These are all the ones I found on NetBSD and Linux. */
	63	# define __SOCKADDR_ALLTYPES \
	64	__SOCKADDR_ONETYPE (sockaddr) \
	65	__SOCKADDR_ONETYPE (sockaddr_at) \
	66	__SOCKADDR_ONETYPE (sockaddr_ax25) \
	67	__SOCKADDR_ONETYPE (sockaddr_dl) \
	68	__SOCKADDR_ONETYPE (sockaddr_eon) \
	69	__SOCKADDR_ONETYPE (sockaddr_in) \
	70	__SOCKADDR_ONETYPE (sockaddr_in6) \
	71	__SOCKADDR_ONETYPE (sockaddr_inarp) \
	72	__SOCKADDR_ONETYPE (sockaddr_ipx) \
	73	__SOCKADDR_ONETYPE (sockaddr_iso) \
	74	__SOCKADDR_ONETYPE (sockaddr_ns) \
	75	__SOCKADDR_ONETYPE (sockaddr_un) \
	76	__SOCKADDR_ONETYPE (sockaddr_x25)
	77
	78	# define __SOCKADDR_ONETYPE(type) struct type *__restrict __##type##__;
	79	typedef union { __SOCKADDR_ALLTYPES
	80	} __SOCKADDR_ARG __attribute__ ((__transparent_union__));
	81	# undef __SOCKADDR_ONETYPE
	82	# define __SOCKADDR_ONETYPE(type) const struct type *__restrict __##type##__;
	83	typedef union { __SOCKADDR_ALLTYPES
	84	} __CONST_SOCKADDR_ARG __attribute__ ((__transparent_union__));
	85	# undef __SOCKADDR_ONETYPE
	86	#endif
	87
	88	#ifdef __USE_GNU
	89	/* For `recvmmsg' and `sendmmsg'. */
	90	struct mmsghdr
	91	{
	92	struct msghdr msg_hdr; /* Actual message header. */
	93	unsigned int msg_len; /* Number of received or sent bytes for the
	94	entry. */
	95	};
	96	#endif
	97
	98
	99	/* Create a new socket of type TYPE in domain DOMAIN, using
	100	protocol PROTOCOL. If PROTOCOL is zero, one is chosen automatically.
	101	Returns a file descriptor for the new socket, or -1 for errors. */
	102	extern int socket (int __domain, int __type, int __protocol) __THROW;
	103
	104	/* Create two new sockets, of type TYPE in domain DOMAIN and using
	105	protocol PROTOCOL, which are connected to each other, and put file
	106	descriptors for them in FDS[0] and FDS[1]. If PROTOCOL is zero,
	107	one will be chosen automatically. Returns 0 on success, -1 for errors. */
	108	extern int socketpair (int __domain, int __type, int __protocol,
	109	int __fds[2]) __THROW;
	110
	111	/* Give the socket FD the local address ADDR (which is LEN bytes long). */
	112	extern int bind (int __fd, __CONST_SOCKADDR_ARG __addr, socklen_t __len)
	113	__THROW;
	114
	115	/* Put the local address of FD into ADDR and its length in LEN. */
	116	extern int getsockname (int __fd, __SOCKADDR_ARG __addr,
	117	socklen_t *__restrict __len) __THROW;
	118
	119	/* Open a connection on socket FD to peer at ADDR (which LEN bytes long).
	120	For connectionless socket types, just set the default address to send to
	121	and the only address from which to accept transmissions.
	122	Return 0 on success, -1 for errors.
	123
	124	This function is a cancellation point and therefore not marked with
	125	__THROW. */
	126	extern int connect (int __fd, __CONST_SOCKADDR_ARG __addr, socklen_t __len);
	127
	128	/* Put the address of the peer connected to socket FD into *ADDR
	129	(which is LEN bytes long), and its actual length into LEN. */
	130	extern int getpeername (int __fd, __SOCKADDR_ARG __addr,
	131	socklen_t *__restrict __len) __THROW;
	132
	133
	134	/* Send N bytes of BUF to socket FD. Returns the number sent or -1.
	135
	136	This function is a cancellation point and therefore not marked with
	137	__THROW. */
	138	extern ssize_t send (int __fd, const void *__buf, size_t __n, int __flags);
	139
	140	/* Read N bytes into BUF from socket FD.
	141	Returns the number read or -1 for errors.
	142
	143	This function is a cancellation point and therefore not marked with
	144	__THROW. */
	145	extern ssize_t recv (int __fd, void *__buf, size_t __n, int __flags);
	146
	147	/* Send N bytes of BUF on socket FD to peer at address ADDR (which is
	148	ADDR_LEN bytes long). Returns the number sent, or -1 for errors.
	149
	150	This function is a cancellation point and therefore not marked with
	151	__THROW. */
	152	extern ssize_t sendto (int __fd, const void *__buf, size_t __n,
	153	int __flags, __CONST_SOCKADDR_ARG __addr,
	154	socklen_t __addr_len);
	155
	156	/* Read N bytes into BUF through socket FD.
	157	If ADDR is not NULL, fill in *ADDR_LEN bytes of it with the address of
	158	the sender, and store the actual size of the address in *ADDR_LEN.
	159	Returns the number of bytes read or -1 for errors.
	160
	161	This function is a cancellation point and therefore not marked with
	162	__THROW. */
	163	extern ssize_t recvfrom (int __fd, void *__restrict __buf, size_t __n,
	164	int __flags, __SOCKADDR_ARG __addr,
	165	socklen_t *__restrict __addr_len);
	166
	167
	168	/* Send a message described MESSAGE on socket FD.
	169	Returns the number of bytes sent, or -1 for errors.
	170
	171	This function is a cancellation point and therefore not marked with
	172	__THROW. */
	173	#ifndef __USE_TIME64_REDIRECTS
	174	extern ssize_t sendmsg (int __fd, const struct msghdr *__message,
	175	int __flags);
	176	#else
	177	# ifdef __REDIRECT
	178	extern ssize_t __REDIRECT (sendmsg, (int __fd, const struct msghdr *__message,
	179	int __flags),
	180	__sendmsg64);
	181	# else
	182	extern ssize_t __sendmsg64 (int __fd, const struct msghdr *__message,
	183	int __flags);
	184	# define sendmsg __sendmsg64
	185	# endif
	186	#endif
	187
	188	#ifdef __USE_GNU
	189	/* Send a VLEN messages as described by VMESSAGES to socket FD.
	190	Returns the number of datagrams successfully written or -1 for errors.
	191
	192	This function is a cancellation point and therefore not marked with
	193	__THROW. */
	194	# ifndef __USE_TIME64_REDIRECTS
	195	extern int sendmmsg (int __fd, struct mmsghdr *__vmessages,
	196	unsigned int __vlen, int __flags);
	197	# else
	198	# ifdef __REDIRECT
	199	extern int __REDIRECT (sendmmsg, (int __fd, struct mmsghdr *__vmessages,
	200	unsigned int __vlen, int __flags),
	201	__sendmmsg64);
	202	# else
	203	extern int __sendmmsg64 (int __fd, struct mmsghdr *__vmessages,
	204	unsigned int __vlen, int __flags);
	205	# define sendmmsg __sendmmsg64
	206	# endif
	207	# endif /* __USE_TIME64_REDIRECTS */
	208	#endif /* __USE_GNU */
	209
	210	/* Receive a message as described by MESSAGE from socket FD.
	211	Returns the number of bytes read or -1 for errors.
	212
	213	This function is a cancellation point and therefore not marked with
	214	__THROW. */
	215	#ifndef __USE_TIME64_REDIRECTS
	216	extern ssize_t recvmsg (int __fd, struct msghdr *__message, int __flags);
	217	#else
	218	# ifdef __REDIRECT
	219	extern ssize_t __REDIRECT (recvmsg,
	220	(int __fd, struct msghdr *__message, int __flags),
	221	__recvmsg64);
	222	# else
	223	extern ssize_t __recvmsg64 (int __fd, struct msghdr *__message, int __flags);
	224	# define recvmsg __recvmsg64
	225	# endif
	226	#endif
	227
	228	#ifdef __USE_GNU
	229	/* Receive up to VLEN messages as described by VMESSAGES from socket FD.
	230	Returns the number of messages received or -1 for errors.
	231
	232	This function is a cancellation point and therefore not marked with
	233	__THROW. */
	234	# ifndef __USE_TIME64_REDIRECTS
	235	extern int recvmmsg (int __fd, struct mmsghdr *__vmessages,
	236	unsigned int __vlen, int __flags,
	237	struct timespec *__tmo);
	238	# else
	239	# ifdef __REDIRECT
	240	extern int __REDIRECT (recvmmsg, (int __fd, struct mmsghdr *__vmessages,
	241	unsigned int __vlen, int __flags,
	242	struct timespec *__tmo),
	243	__recvmmsg64);
	244	# else
	245	# define recvmmsg __recvmmsg64
	246	# endif
	247	# endif
	248	#endif
	249
	250
	251	/* Put the current value for socket FD's option OPTNAME at protocol level LEVEL
	252	into OPTVAL (which is OPTLEN bytes long), and set OPTLEN to the value's
	253	actual length. Returns 0 on success, -1 for errors. */
	254	#ifndef __USE_TIME64_REDIRECTS
	255	extern int getsockopt (int __fd, int __level, int __optname,
	256	void *__restrict __optval,
	257	socklen_t *__restrict __optlen) __THROW;
	258	#else
	259	# ifdef __REDIRECT
	260	extern int __REDIRECT_NTH (getsockopt,
	261	(int __fd, int __level, int __optname,
	262	void *__restrict __optval,
	263	socklen_t *__restrict __optlen),
	264	__getsockopt64);
	265	# else
	266	extern int __getsockopt64 (int __fd, int __level, int __optname,
	267	void *__restrict __optval,
	268	socklen_t *__restrict __optlen) __THROW;
	269	# define getsockopt __getsockopt64
	270	# endif
	271	#endif
	272
	273	/* Set socket FD's option OPTNAME at protocol level LEVEL
	274	to *OPTVAL (which is OPTLEN bytes long).
	275	Returns 0 on success, -1 for errors. */
	276	#ifndef __USE_TIME64_REDIRECTS
	277	extern int setsockopt (int __fd, int __level, int __optname,
	278	const void *__optval, socklen_t __optlen) __THROW;
	279	#else
	280	# ifdef __REDIRECT
	281	extern int __REDIRECT_NTH (setsockopt,
	282	(int __fd, int __level, int __optname,
	283	const void *__optval, socklen_t __optlen),
	284	__setsockopt64);
	285	# else
	286	extern int __setsockopt64 (int __fd, int __level, int __optname,
	287	const void *__optval, socklen_t __optlen) __THROW;
	288	# define setsockopt __setsockopt64
	289	# endif
	290	#endif
	291
	292
	293	/* Prepare to accept connections on socket FD.
	294	N connection requests will be queued before further requests are refused.
	295	Returns 0 on success, -1 for errors. */
	296	extern int listen (int __fd, int __n) __THROW;
	297
	298	/* Await a connection on socket FD.
	299	When a connection arrives, open a new socket to communicate with it,
	300	set ADDR (which is ADDR_LEN bytes long) to the address of the connecting
	301	peer and *ADDR_LEN to the address's actual length, and return the
	302	new socket's descriptor, or -1 for errors.
	303
	304	This function is a cancellation point and therefore not marked with
	305	__THROW. */
	306	extern int accept (int __fd, __SOCKADDR_ARG __addr,
	307	socklen_t *__restrict __addr_len);
	308
	309	#ifdef __USE_GNU
	310	/* Similar to 'accept' but takes an additional parameter to specify flags.
	311
	312	This function is a cancellation point and therefore not marked with
	313	__THROW. */
	314	extern int accept4 (int __fd, __SOCKADDR_ARG __addr,
	315	socklen_t *__restrict __addr_len, int __flags);
	316	#endif
	317
	318	/* Shut down all or part of the connection open on socket FD.
	319	HOW determines what to shut down:
	320	SHUT_RD = No more receptions;
	321	SHUT_WR = No more transmissions;
	322	SHUT_RDWR = No more receptions or transmissions.
	323	Returns 0 on success, -1 for errors. */
	324	extern int shutdown (int __fd, int __how) __THROW;
	325
	326
	327	#ifdef __USE_XOPEN2K
	328	/* Determine whether socket is at a out-of-band mark. */
	329	extern int sockatmark (int __fd) __THROW;
	330	#endif
	331
	332
	333	#ifdef __USE_MISC
	334	/* FDTYPE is S_IFSOCK or another S_IF* macro defined in <sys/stat.h>;
	335	returns 1 if FD is open on an object of the indicated type, 0 if not,
	336	or -1 for errors (setting errno). */
	337	extern int isfdtype (int __fd, int __fdtype) __THROW;
	338	#endif
	339
	340
	341	/* Define some macros helping to catch buffer overflows. */
	342	#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
	343	# include <bits/socket2.h>
	344	#endif
	345
	346	__END_DECLS
	347
	348	#endif /* sys/socket.h */