sysdeps/mach/hurd/recvfrom.c

   1 /* Copyright (C) 1994-2020 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 #include <hurd.h>
  22 #include <hurd/fd.h>
  23 #include <hurd/socket.h>
  24
  25 /* Read N bytes into BUF through socket FD.
  26    If ADDR is not NULL, fill in *ADDR_LEN bytes of it with tha address of
  27    the sender, and store the actual size of the address in *ADDR_LEN.
  28    Returns the number of bytes read or -1 for errors.  */
  29 ssize_t
  30 __recvfrom (int fd, void *buf, size_t n, int flags, __SOCKADDR_ARG addrarg,
  31             socklen_t *addr_len)
  32 {
  33   error_t err;
  34   mach_port_t addrport;
  35   char *bufp = buf;
  36   mach_msg_type_number_t nread = n;
  37   mach_port_t *ports;
  38   mach_msg_type_number_t nports = 0;
  39   char *cdata = NULL;
  40   mach_msg_type_number_t clen = 0;
  41   struct sockaddr *addr = addrarg.__sockaddr__;
  42
  43   if (err = HURD_DPORT_USE (fd, __socket_recv (port, &addrport,
  44                                                flags, &bufp, &nread,
  45                                                &ports, &nports,
  46                                                &cdata, &clen,
  47                                                &flags,
  48                                                n)))
  49     return __hurd_sockfail (fd, flags, err);
  50
  51   /* Get address data for the returned address port if requested.  */
  52   if (addr != NULL && addrport != MACH_PORT_NULL)
  53     {
  54       char *buf = (char *) addr;
  55       mach_msg_type_number_t buflen = *addr_len;
  56       int type;
  57
  58       err = __socket_whatis_address (addrport, &type, &buf, &buflen);
  59       if (err == EOPNOTSUPP)
  60         /* If the protocol server can't tell us the address, just return a
  61            zero-length one.  */
  62         {
  63           buf = (char *)addr;
  64           buflen = 0;
  65           err = 0;
  66         }
  67
  68       if (err)
  69         {
  70           __mach_port_deallocate (__mach_task_self (), addrport);
  71           return __hurd_sockfail (fd, flags, err);
  72         }
  73
  74       if (*addr_len > buflen)
  75         *addr_len = buflen;
  76
  77       if (buf != (char *) addr)
  78         {
  79           memcpy (addr, buf, *addr_len);
  80           __vm_deallocate (__mach_task_self (), (vm_address_t) buf, buflen);
  81         }
  82
  83       if (buflen > 0)
  84         addr->sa_family = type;
  85     }
  86   else if (addr_len != NULL)
  87     *addr_len = 0;
  88
  89   __mach_port_deallocate (__mach_task_self (), addrport);
  90
  91   /* Toss control data; we don't care.  */
  92   __vm_deallocate (__mach_task_self (), (vm_address_t) cdata, clen);
  93
  94   if (bufp != buf)
  95     {
  96       memcpy (buf, bufp, nread);
  97       __vm_deallocate (__mach_task_self (), (vm_address_t) bufp, nread);
  98     }
  99
 100   return nread;
 101 }
 102
 103 weak_alias (__recvfrom, recvfrom)