sysdeps/mach/hurd/getpeername.c

   1 /* Copyright (C) 1992-2024 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <string.h>
  20 #include <sys/socket.h>
  21
  22 #include <hurd.h>
  23 #include <hurd/fd.h>
  24 #include <hurd/socket.h>
  25
  26 /* Put the address of the peer connected to socket FD into *ADDR
  27    (which is *LEN bytes long), and its actual length into *LEN.  */
  28 int
  29 __getpeername (int fd, __SOCKADDR_ARG addrarg, socklen_t *len)
  30 {
  31   error_t err;
  32   mach_msg_type_number_t buflen = *len;
  33   int type;
  34   struct sockaddr *addr = addrarg.__sockaddr__;
  35   char *buf = (char *) addr;
  36   addr_port_t aport;
  37
  38   if (err = HURD_DPORT_USE (fd, __socket_peername (port, &aport)))
  39     return __hurd_dfail (fd, err);
  40
  41   err = __socket_whatis_address (aport, &type, &buf, &buflen);
  42   __mach_port_deallocate (__mach_task_self (), aport);
  43
  44   if (err)
  45     return __hurd_dfail (fd, err);
  46
  47   if (*len > buflen)
  48     *len = buflen;
  49
  50   if (buf != (char *) addr)
  51     {
  52       memcpy (addr, buf, *len);
  53       __vm_deallocate (__mach_task_self (), (vm_address_t) buf, buflen);
  54     }
  55
  56   const sa_family_t family = type;
  57   if (*len > offsetof (struct sockaddr, sa_family))
  58     {
  59       if (*len < (char *) (&addr->sa_family + 1) - (char *) addr)
  60         memcpy (&addr->sa_family, &family,
  61                 *len - offsetof (struct sockaddr, sa_family));
  62       else
  63         addr->sa_family = family;
  64     }
  65
  66   return 0;
  67 }
  68
  69 weak_alias (__getpeername, getpeername)