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 #ifndef __USE_TIME_BITS64
 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 #  defien 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_TIME_BITS64
 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_TIME_BITS64 */
 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_TIME_BITS64
 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_TIME_BITS64
 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_TIME_BITS64
 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_TIME_BITS64
 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 */