mdw@git.distorted.org.uk Git - mLib/blob - sys/fdpass.h

   1 /* -*-c-*-
   2  *
   3  * File descriptor passing
   4  *
   5  * (c) 2003 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of the mLib utilities library.
  11  *
  12  * mLib is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU Library General Public License as
  14  * published by the Free Software Foundation; either version 2 of the
  15  * License, or (at your option) any later version.
  16  *
  17  * mLib is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with mLib; if not, write to the Free
  24  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  25  * MA 02111-1307, USA.
  26  */
  27
  28 #ifndef MLIB_FDPASS_H
  29 #define MLIB_FDPASS_H
  30
  31 #ifdef __cplusplus
  32   extern "C" {
  33 #endif
  34
  35 /*----- Header files ------------------------------------------------------*/
  36
  37 #include <sys/types.h>
  38 #include <unistd.h>
  39
  40 /*----- Functions provided ------------------------------------------------*/
  41
  42 /* --- @fdpass_send@ --- *
  43  *
  44  * Arguments:   @int sock@ = socket to send over
  45  *              @int fd@ = file descriptor to send
  46  *              @const void *p@ = pointer to data to send
  47  *              @size_t sz@ = size of buffer to send
  48  *
  49  * Returns:     On error, @-1@, otherwise number of bytes transferred from
  50  *              @p@.
  51  *
  52  * Use:         Sends a copy of file descriptor @fd@ to the other end of
  53  *              @sock@.
  54  */
  55
  56 extern ssize_t fdpass_send(int /*sock*/, int /*fd*/,
  57                            const void */*p*/, size_t /*sz*/);
  58
  59 /* --- @fdpass_recv@ --- *
  60  *
  61  * Arguments:   @int sock@ = socket to send over
  62  *              @int *fd@ = where to put received descriptor
  63  *              @void *p@ = pointer to where to put data
  64  *              @size_t sz@ = size of buffer
  65  *
  66  * Returns:     On error, @-1@, otherwise number of bytes transferred.
  67  *
  68  * Use:         Receives a file descriptor.  If the call succeeds, and there
  69  *              was a file descriptor, then @fd@ won't be @-1@ on exit;
  70  *              otherwise it will.  At most one descriptor will be collected.
  71  */
  72
  73 extern ssize_t fdpass_recv(int /*sock*/, int */*fd*/,
  74                            void */*p*/, size_t /*sz*/);
  75
  76 /*----- That's all, folks -------------------------------------------------*/
  77
  78 #ifdef __cplusplus
  79   }
  80 #endif
  81
  82 #endif