socket/sys/socket.h

   1 /* Declarations of socket constants, types, and functions.
   2    Copyright (C) 1991-2021 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 tha 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 extern ssize_t sendmsg (int __fd, const struct msghdr *__message,
 174                         int __flags);
 175
 176 #ifdef __USE_GNU
 177 /* Send a VLEN messages as described by VMESSAGES to socket FD.
 178    Returns the number of datagrams successfully written or -1 for errors.
 179
 180    This function is a cancellation point and therefore not marked with
 181    __THROW.  */
 182 extern int sendmmsg (int __fd, struct mmsghdr *__vmessages,
 183                      unsigned int __vlen, int __flags);
 184 #endif
 185
 186 /* Receive a message as described by MESSAGE from socket FD.
 187    Returns the number of bytes read or -1 for errors.
 188
 189    This function is a cancellation point and therefore not marked with
 190    __THROW.  */
 191 extern ssize_t recvmsg (int __fd, struct msghdr *__message, int __flags);
 192
 193 #ifdef __USE_GNU
 194 /* Receive up to VLEN messages as described by VMESSAGES from socket FD.
 195    Returns the number of messages received or -1 for errors.
 196
 197    This function is a cancellation point and therefore not marked with
 198    __THROW.  */
 199 # ifndef __USE_TIME_BITS64
 200 extern int recvmmsg (int __fd, struct mmsghdr *__vmessages,
 201                      unsigned int __vlen, int __flags,
 202                      struct timespec *__tmo);
 203 # else
 204 #  ifdef __REDIRECT
 205 extern int __REDIRECT (recvmmsg, (int __fd, struct mmsghdr *__vmessages,
 206                                   unsigned int __vlen, int __flags,
 207                                   struct timespec *__tmo),
 208                        __recvmmsg64);
 209 #  else
 210 #   define recvmmsg __recvmmsg64
 211 #  endif
 212 # endif
 213 #endif
 214
 215
 216 /* Put the current value for socket FD's option OPTNAME at protocol level LEVEL
 217    into OPTVAL (which is *OPTLEN bytes long), and set *OPTLEN to the value's
 218    actual length.  Returns 0 on success, -1 for errors.  */
 219 extern int getsockopt (int __fd, int __level, int __optname,
 220                        void *__restrict __optval,
 221                        socklen_t *__restrict __optlen) __THROW;
 222
 223 /* Set socket FD's option OPTNAME at protocol level LEVEL
 224    to *OPTVAL (which is OPTLEN bytes long).
 225    Returns 0 on success, -1 for errors.  */
 226 extern int setsockopt (int __fd, int __level, int __optname,
 227                        const void *__optval, socklen_t __optlen) __THROW;
 228
 229
 230 /* Prepare to accept connections on socket FD.
 231    N connection requests will be queued before further requests are refused.
 232    Returns 0 on success, -1 for errors.  */
 233 extern int listen (int __fd, int __n) __THROW;
 234
 235 /* Await a connection on socket FD.
 236    When a connection arrives, open a new socket to communicate with it,
 237    set *ADDR (which is *ADDR_LEN bytes long) to the address of the connecting
 238    peer and *ADDR_LEN to the address's actual length, and return the
 239    new socket's descriptor, or -1 for errors.
 240
 241    This function is a cancellation point and therefore not marked with
 242    __THROW.  */
 243 extern int accept (int __fd, __SOCKADDR_ARG __addr,
 244                    socklen_t *__restrict __addr_len);
 245
 246 #ifdef __USE_GNU
 247 /* Similar to 'accept' but takes an additional parameter to specify flags.
 248
 249    This function is a cancellation point and therefore not marked with
 250    __THROW.  */
 251 extern int accept4 (int __fd, __SOCKADDR_ARG __addr,
 252                     socklen_t *__restrict __addr_len, int __flags);
 253 #endif
 254
 255 /* Shut down all or part of the connection open on socket FD.
 256    HOW determines what to shut down:
 257      SHUT_RD   = No more receptions;
 258      SHUT_WR   = No more transmissions;
 259      SHUT_RDWR = No more receptions or transmissions.
 260    Returns 0 on success, -1 for errors.  */
 261 extern int shutdown (int __fd, int __how) __THROW;
 262
 263
 264 #ifdef __USE_XOPEN2K
 265 /* Determine whether socket is at a out-of-band mark.  */
 266 extern int sockatmark (int __fd) __THROW;
 267 #endif
 268
 269
 270 #ifdef __USE_MISC
 271 /* FDTYPE is S_IFSOCK or another S_IF* macro defined in <sys/stat.h>;
 272    returns 1 if FD is open on an object of the indicated type, 0 if not,
 273    or -1 for errors (setting errno).  */
 274 extern int isfdtype (int __fd, int __fdtype) __THROW;
 275 #endif
 276
 277
 278 /* Define some macros helping to catch buffer overflows.  */
 279 #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
 280 # include <bits/socket2.h>
 281 #endif
 282
 283 __END_DECLS
 284
 285 #endif /* sys/socket.h */