bits/socket.h

   1 /* System-specific socket constants and types.  4.4 BSD version.
   2    Copyright (C) 1991-2024 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 License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    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; see the file COPYING.LIB.  If
  17    not, see <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef __BITS_SOCKET_H
  20 #define __BITS_SOCKET_H 1
  21
  22 #ifndef _SYS_SOCKET_H
  23 # error "Never include <bits/socket.h> directly; use <sys/socket.h> instead."
  24 #endif
  25
  26 #define __need_size_t
  27 #include <stddef.h>
  28
  29 #include <bits/wordsize.h>
  30 #include <bits/types.h>
  31
  32 /* Type for length arguments in socket calls.  */
  33 #ifndef __socklen_t_defined
  34 typedef __socklen_t socklen_t;
  35 # define __socklen_t_defined
  36 #endif
  37
  38
  39 /* Types of sockets.  */
  40 enum __socket_type
  41 {
  42   SOCK_STREAM = 1,              /* Sequenced, reliable, connection-based
  43                                    byte streams.  */
  44 #define SOCK_STREAM SOCK_STREAM
  45   SOCK_DGRAM = 2,               /* Connectionless, unreliable datagrams
  46                                    of fixed maximum length.  */
  47 #define SOCK_DGRAM SOCK_DGRAM
  48   SOCK_RAW = 3,                 /* Raw protocol interface.  */
  49 #define SOCK_RAW SOCK_RAW
  50   SOCK_RDM = 4,                 /* Reliably-delivered messages.  */
  51 #define SOCK_RDM SOCK_RDM
  52   SOCK_SEQPACKET = 5,           /* Sequenced, reliable, connection-based,
  53                                    datagrams of fixed maximum length.  */
  54 #define SOCK_SEQPACKET SOCK_SEQPACKET
  55
  56 #define SOCK_MAX (SOCK_SEQPACKET + 1)
  57   /* Mask which covers at least up to SOCK_MASK-1.
  58      The remaining bits are used as flags. */
  59 #define SOCK_TYPE_MASK 0xf
  60
  61   /* Flags to be ORed into the type parameter of socket and socketpair and
  62      used for the flags parameter of accept4.  */
  63
  64   SOCK_CLOEXEC = 0x10000000,    /* Atomically set close-on-exec flag for the
  65                                    new descriptor(s).  */
  66 #define SOCK_CLOEXEC SOCK_CLOEXEC
  67
  68   SOCK_NONBLOCK = 0x20000000    /* Atomically mark descriptor(s) as
  69                                    non-blocking.  */
  70 #define SOCK_NONBLOCK SOCK_NONBLOCK
  71 };
  72
  73 /* Protocol families.  */
  74 #define PF_UNSPEC       0       /* Unspecified.  */
  75 #define PF_LOCAL        1       /* Local to host (pipes and file-domain).  */
  76 #define PF_UNIX         PF_LOCAL /* Old BSD name for PF_LOCAL.  */
  77 #define PF_FILE         PF_LOCAL /* POSIX name for PF_LOCAL.  */
  78 #define PF_INET         2       /* IP protocol family.  */
  79 #define PF_IMPLINK      3       /* ARPAnet IMP protocol.  */
  80 #define PF_PUP          4       /* PUP protocols.  */
  81 #define PF_CHAOS        5       /* MIT Chaos protocols.  */
  82 #define PF_NS           6       /* Xerox NS protocols.  */
  83 #define PF_ISO          7       /* ISO protocols.  */
  84 #define PF_OSI          PF_ISO
  85 #define PF_ECMA         8       /* ECMA protocols.  */
  86 #define PF_DATAKIT      9       /* AT&T Datakit protocols.  */
  87 #define PF_CCITT        10      /* CCITT protocols (X.25 et al).  */
  88 #define PF_SNA          11      /* IBM SNA protocol.  */
  89 #define PF_DECnet       12      /* DECnet protocols.  */
  90 #define PF_DLI          13      /* Direct data link interface.  */
  91 #define PF_LAT          14      /* DEC Local Area Transport protocol.  */
  92 #define PF_HYLINK       15      /* NSC Hyperchannel protocol.  */
  93 #define PF_APPLETALK    16      /* Don't use this.  */
  94 #define PF_ROUTE        17      /* Internal Routing Protocol.  */
  95 #define PF_LINK         18      /* Link layer interface.  */
  96 #define PF_XTP          19      /* eXpress Transfer Protocol (no AF).  */
  97 #define PF_COIP         20      /* Connection-oriented IP, aka ST II.  */
  98 #define PF_CNT          21      /* Computer Network Technology.  */
  99 #define PF_RTIP         22      /* Help Identify RTIP packets.  **/
 100 #define PF_IPX          23      /* Novell Internet Protocol.  */
 101 #define PF_SIP          24      /* Simple Internet Protocol.  */
 102 #define PF_PIP          25      /* Help Identify PIP packets.  */
 103 #define PF_INET6        26      /* IP version 6.  */
 104 #define PF_MAX          27
 105
 106 /* Address families.  */
 107 #define AF_UNSPEC       PF_UNSPEC
 108 #define AF_LOCAL        PF_LOCAL
 109 #define AF_UNIX         PF_UNIX
 110 #define AF_FILE         PF_FILE
 111 #define AF_INET         PF_INET
 112 #define AF_IMPLINK      PF_IMPLINK
 113 #define AF_PUP          PF_PUP
 114 #define AF_CHAOS        PF_CHAOS
 115 #define AF_NS           PF_NS
 116 #define AF_ISO          PF_ISO
 117 #define AF_OSI          PF_OSI
 118 #define AF_ECMA         PF_ECMA
 119 #define AF_DATAKIT      PF_DATAKIT
 120 #define AF_CCITT        PF_CCITT
 121 #define AF_SNA          PF_SNA
 122 #define AF_DECnet       PF_DECnet
 123 #define AF_DLI          PF_DLI
 124 #define AF_LAT          PF_LAT
 125 #define AF_HYLINK       PF_HYLINK
 126 #define AF_APPLETALK    PF_APPLETALK
 127 #define AF_ROUTE        PF_ROUTE
 128 #define AF_LINK         PF_LINK
 129 #ifdef __USE_MISC
 130 # define        pseudo_AF_XTP   PF_XTP
 131 #endif
 132 #define AF_COIP         PF_COIP
 133 #define AF_CNT          PF_CNT
 134 #ifdef __USE_MISC
 135 # define pseudo_AF_RTIP PF_RTIP
 136 #endif
 137 #define AF_IPX          PF_IPX
 138 #define AF_SIP          PF_SIP
 139 #ifdef __USE_MISC
 140 # define pseudo_AF_PIP  PF_PIP
 141 #endif
 142 #define AF_INET6        PF_INET6
 143 #define AF_MAX          PF_MAX
 144
 145 /* Maximum queue length specifiable by listen.  */
 146 #define SOMAXCONN       128     /* 5 on the original 4.4 BSD.  */
 147
 148 /* Get the definition of the macro to define the common sockaddr members.  */
 149 #include <bits/sockaddr.h>
 150
 151 /* Structure describing a generic socket address.  */
 152 struct sockaddr
 153   {
 154     __SOCKADDR_COMMON (sa_);    /* Common data: address family and length.  */
 155     char sa_data[14];           /* Address data.  */
 156   };
 157
 158
 159 /* Structure large enough to hold any socket address (with the historical
 160    exception of AF_UNIX).  */
 161 #if __WORDSIZE == 64
 162 # define __ss_aligntype __uint64_t
 163 #else
 164 # define __ss_aligntype __uint32_t
 165 #endif
 166 #define _SS_PADSIZE \
 167   (_SS_SIZE - __SOCKADDR_COMMON_SIZE - sizeof (__ss_aligntype))
 168
 169 struct sockaddr_storage
 170   {
 171     __SOCKADDR_COMMON (ss_);    /* Address family, etc.  */
 172     char __ss_padding[_SS_PADSIZE];
 173     __ss_aligntype __ss_align;  /* Force desired alignment.  */
 174   };
 175
 176
 177 /* Bits in the FLAGS argument to `send', `recv', et al.  */
 178 enum
 179   {
 180     MSG_OOB             = 0x01, /* Process out-of-band data.  */
 181 #define MSG_OOB MSG_OOB
 182     MSG_PEEK            = 0x02, /* Peek at incoming messages.  */
 183 #define MSG_PEEK MSG_PEEK
 184     MSG_DONTROUTE       = 0x04, /* Don't use local routing.  */
 185 #define MSG_DONTROUTE MSG_DONTROUTE
 186     MSG_EOR             = 0x08, /* Data completes record.  */
 187 #define MSG_EOR MSG_EOR
 188     MSG_TRUNC           = 0x10, /* Data discarded before delivery.  */
 189 #define MSG_TRUNC MSG_TRUNC
 190     MSG_CTRUNC          = 0x20, /* Control data lost before delivery.  */
 191 #define MSG_CTRUNC MSG_CTRUNC
 192     MSG_WAITALL         = 0x40, /* Wait for full request or error.  */
 193 #define MSG_WAITALL MSG_WAITALL
 194     MSG_DONTWAIT        = 0x80, /* This message should be nonblocking.  */
 195 #define MSG_DONTWAIT MSG_DONTWAIT
 196     MSG_NOSIGNAL        = 0x0400        /* Do not generate SIGPIPE on EPIPE.  */
 197 #define MSG_NOSIGNAL MSG_NOSIGNAL
 198   };
 199
 200
 201 /* Structure describing messages sent by
 202    `sendmsg' and received by `recvmsg'.  */
 203 struct msghdr
 204   {
 205     void *msg_name;             /* Address to send to/receive from.  */
 206     socklen_t msg_namelen;      /* Length of address data.  */
 207
 208     struct iovec *msg_iov;      /* Vector of data to send/receive into.  */
 209     int msg_iovlen;             /* Number of elements in the vector.  */
 210
 211     void *msg_control;          /* Ancillary data (eg BSD filedesc passing). */
 212     socklen_t msg_controllen;   /* Ancillary data buffer length.  */
 213
 214     int msg_flags;              /* Flags in received message.  */
 215   };
 216
 217 /* Structure used for storage of ancillary data object information.  */
 218 struct cmsghdr
 219   {
 220     socklen_t cmsg_len;         /* Length of data in cmsg_data plus length
 221                                    of cmsghdr structure.  */
 222     int cmsg_level;             /* Originating protocol.  */
 223     int cmsg_type;              /* Protocol specific type.  */
 224 #if __glibc_c99_flexarr_available
 225     __extension__ unsigned char __cmsg_data __flexarr; /* Ancillary data.  */
 226 #endif
 227   };
 228
 229 /* Ancillary data object manipulation macros.  */
 230 #if __glibc_c99_flexarr_available
 231 # define CMSG_DATA(cmsg) ((cmsg)->__cmsg_data)
 232 #else
 233 # define CMSG_DATA(cmsg) ((unsigned char *) ((struct cmsghdr *) (cmsg) + 1))
 234 #endif
 235
 236 #define CMSG_NXTHDR(mhdr, cmsg) __cmsg_nxthdr (mhdr, cmsg)
 237
 238 #define CMSG_FIRSTHDR(mhdr) \
 239   ((size_t) (mhdr)->msg_controllen >= sizeof (struct cmsghdr)                 \
 240    ? (struct cmsghdr *) (mhdr)->msg_control : (struct cmsghdr *) 0)
 241
 242 #define CMSG_ALIGN(len) (((len) + sizeof (size_t) - 1) \
 243                            & (size_t) ~(sizeof (size_t) - 1))
 244 #define CMSG_SPACE(len) (CMSG_ALIGN (len) \
 245                          + CMSG_ALIGN (sizeof (struct cmsghdr)))
 246 #define CMSG_LEN(len)   (CMSG_ALIGN (sizeof (struct cmsghdr)) + (len))
 247
 248 /* Given a length, return the additional padding necessary such that
 249    len + __CMSG_PADDING(len) == CMSG_ALIGN (len).  */
 250 #define __CMSG_PADDING(len) ((sizeof (size_t) \
 251                               - ((len) & (sizeof (size_t) - 1))) \
 252                              & (sizeof (size_t) - 1))
 253
 254 extern struct cmsghdr *__cmsg_nxthdr (struct msghdr *__mhdr,
 255                                       struct cmsghdr *__cmsg) __THROW;
 256 #ifdef __USE_EXTERN_INLINES
 257 # ifndef _EXTERN_INLINE
 258 #  define _EXTERN_INLINE __extern_inline
 259 # endif
 260 _EXTERN_INLINE struct cmsghdr *
 261 __NTH (__cmsg_nxthdr (struct msghdr *__mhdr, struct cmsghdr *__cmsg))
 262 {
 263   /* We may safely assume that __cmsg lies between __mhdr->msg_control and
 264      __mhdr->msg_controllen because the user is required to obtain the first
 265      cmsg via CMSG_FIRSTHDR, set its length, then obtain subsequent cmsgs
 266      via CMSG_NXTHDR, setting lengths along the way.  However, we don't yet
 267      trust the value of __cmsg->cmsg_len and therefore do not use it in any
 268      pointer arithmetic until we check its value.  */
 269
 270   unsigned char * __msg_control_ptr = (unsigned char *) __mhdr->msg_control;
 271   unsigned char * __cmsg_ptr = (unsigned char *) __cmsg;
 272
 273   size_t __size_needed = sizeof (struct cmsghdr)
 274                          + __CMSG_PADDING (__cmsg->cmsg_len);
 275
 276   /* The current header is malformed, too small to be a full header.  */
 277   if ((size_t) __cmsg->cmsg_len < sizeof (struct cmsghdr))
 278     return (struct cmsghdr *) 0;
 279
 280   /* There isn't enough space between __cmsg and the end of the buffer to
 281   hold the current cmsg *and* the next one.  */
 282   if (((size_t)
 283          (__msg_control_ptr + __mhdr->msg_controllen - __cmsg_ptr)
 284        < __size_needed)
 285       || ((size_t)
 286             (__msg_control_ptr + __mhdr->msg_controllen - __cmsg_ptr
 287              - __size_needed)
 288           < __cmsg->cmsg_len))
 289
 290     return (struct cmsghdr *) 0;
 291
 292   /* Now, we trust cmsg_len and can use it to find the next header.  */
 293   __cmsg = (struct cmsghdr *) ((unsigned char *) __cmsg
 294                                + CMSG_ALIGN (__cmsg->cmsg_len));
 295   return __cmsg;
 296 }
 297 #endif  /* Use `extern inline'.  */
 298
 299 /* Socket level message types.  */
 300 enum
 301   {
 302     SCM_RIGHTS = 0x01,          /* Access rights (array of int).  */
 303 #define SCM_RIGHTS SCM_RIGHTS
 304     SCM_TIMESTAMP = 0x02,       /* Timestamp (struct timeval).  */
 305 #define SCM_TIMESTAMP SCM_TIMESTAMP
 306     SCM_CREDS = 0x03            /* Process creds (struct cmsgcred).  */
 307 #define SCM_CREDS SCM_CREDS
 308   };
 309
 310 #ifdef __USE_MISC
 311 /* Unfortunately, BSD practice dictates this structure be of fixed size.
 312    If there are more than CMGROUP_MAX groups, the list is truncated.
 313    (On GNU systems, the `cmcred_euid' field is just the first in the
 314    list of effective UIDs.)  */
 315 #define CMGROUP_MAX     16
 316
 317 /* Structure delivered by SCM_CREDS.  This describes the identity of the
 318    sender of the data simultaneously received on the socket.  By BSD
 319    convention, this is included only when a sender on a AF_LOCAL socket
 320    sends cmsg data of this type and size; the sender's structure is
 321    ignored, and the system fills in the various IDs of the sender process.  */
 322 struct cmsgcred
 323   {
 324     __pid_t cmcred_pid;
 325     __uid_t cmcred_uid;
 326     __uid_t cmcred_euid;
 327     __gid_t cmcred_gid;
 328     int cmcred_ngroups;
 329     __gid_t cmcred_groups[CMGROUP_MAX];
 330   };
 331 #endif
 332
 333 /* Protocol number used to manipulate socket-level options
 334    with `getsockopt' and `setsockopt'.  */
 335 #define SOL_SOCKET      0xffff
 336
 337 /* Socket-level options for `getsockopt' and `setsockopt'.  */
 338 enum
 339   {
 340     SO_DEBUG = 0x0001,          /* Record debugging information.  */
 341 #define SO_DEBUG SO_DEBUG
 342     SO_ACCEPTCONN = 0x0002,     /* Accept connections on socket.  */
 343 #define SO_ACCEPTCONN SO_ACCEPTCONN
 344     SO_REUSEADDR = 0x0004,      /* Allow reuse of local addresses.  */
 345 #define SO_REUSEADDR SO_REUSEADDR
 346     SO_KEEPALIVE = 0x0008,      /* Keep connections alive and send
 347                                    SIGPIPE when they die.  */
 348 #define SO_KEEPALIVE SO_KEEPALIVE
 349     SO_DONTROUTE = 0x0010,      /* Don't do local routing.  */
 350 #define SO_DONTROUTE SO_DONTROUTE
 351     SO_BROADCAST = 0x0020,      /* Allow transmission of
 352                                    broadcast messages.  */
 353 #define SO_BROADCAST SO_BROADCAST
 354     SO_USELOOPBACK = 0x0040,    /* Use the software loopback to avoid
 355                                    hardware use when possible.  */
 356 #define SO_USELOOPBACK SO_USELOOPBACK
 357     SO_LINGER = 0x0080,         /* Block on close of a reliable
 358                                    socket to transmit pending data.  */
 359 #define SO_LINGER SO_LINGER
 360     SO_OOBINLINE = 0x0100,      /* Receive out-of-band data in-band.  */
 361 #define SO_OOBINLINE SO_OOBINLINE
 362     SO_REUSEPORT = 0x0200,      /* Allow local address and port reuse.  */
 363 #define SO_REUSEPORT SO_REUSEPORT
 364     SO_SNDBUF = 0x1001,         /* Send buffer size.  */
 365 #define SO_SNDBUF SO_SNDBUF
 366     SO_RCVBUF = 0x1002,         /* Receive buffer.  */
 367 #define SO_RCVBUF SO_RCVBUF
 368     SO_SNDLOWAT = 0x1003,       /* Send low-water mark.  */
 369 #define SO_SNDLOWAT SO_SNDLOWAT
 370     SO_RCVLOWAT = 0x1004,       /* Receive low-water mark.  */
 371 #define SO_RCVLOWAT SO_RCVLOWAT
 372     SO_SNDTIMEO = 0x1005,       /* Send timeout.  */
 373 #define SO_SNDTIMEO SO_SNDTIMEO
 374     SO_RCVTIMEO = 0x1006,       /* Receive timeout.  */
 375 #define SO_RCVTIMEO SO_RCVTIMEO
 376     SO_ERROR = 0x1007,          /* Get and clear error status.  */
 377 #define SO_ERROR SO_ERROR
 378     SO_STYLE = 0x1008,          /* Get socket connection style.  */
 379 #define SO_STYLE SO_STYLE
 380     SO_TYPE = SO_STYLE          /* Compatible name for SO_STYLE.  */
 381 #define SO_TYPE SO_TYPE
 382   };
 383
 384 /* Structure used to manipulate the SO_LINGER option.  */
 385 struct linger
 386   {
 387     int l_onoff;                /* Nonzero to linger on close.  */
 388     int l_linger;               /* Time to linger.  */
 389   };
 390
 391 #endif  /* bits/socket.h */