sysdeps/mach/hurd/recvfrom.c

   1 /* Copyright (C) 1994-2024 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 #include <hurd.h>
  22 #include <hurd/fd.h>
  23 #include <hurd/socket.h>
  24 #include <sysdep-cancel.h>
  25
  26 /* Read N bytes into BUF through socket FD.
  27    If ADDR is not NULL, fill in *ADDR_LEN bytes of it with the address of
  28    the sender, and store the actual size of the address in *ADDR_LEN.
  29    Returns the number of bytes read or -1 for errors.  */
  30 ssize_t
  31 __recvfrom (int fd, void *buf, size_t n, int flags, __SOCKADDR_ARG addrarg,
  32             socklen_t *addr_len)
  33 {
  34   error_t err;
  35   mach_port_t addrport;
  36   char *bufp = buf;
  37   mach_msg_type_number_t nread = n;
  38   mach_port_t *ports;
  39   mach_msg_type_number_t nports = 0;
  40   char *cdata = NULL;
  41   mach_msg_type_number_t clen = 0;
  42   struct sockaddr *addr = addrarg.__sockaddr__;
  43   int cancel_oldtype;
  44
  45   cancel_oldtype = LIBC_CANCEL_ASYNC();
  46   err = HURD_DPORT_USE_CANCEL (fd, __socket_recv (port, &addrport,
  47                                                   flags, &bufp, &nread,
  48                                                   &ports, &nports,
  49                                                   &cdata, &clen,
  50                                                   &flags,
  51                                                   n));
  52   LIBC_CANCEL_RESET (cancel_oldtype);
  53
  54   if (err)
  55     return __hurd_sockfail (fd, flags, err);
  56
  57   /* Get address data for the returned address port if requested.  */
  58   if (addr != NULL && addrport != MACH_PORT_NULL)
  59     {
  60       char *buf = (char *) addr;
  61       mach_msg_type_number_t buflen = *addr_len;
  62       int type;
  63
  64       cancel_oldtype = LIBC_CANCEL_ASYNC();
  65       err = __socket_whatis_address (addrport, &type, &buf, &buflen);
  66       LIBC_CANCEL_RESET (cancel_oldtype);
  67       if (err == EOPNOTSUPP)
  68         /* If the protocol server can't tell us the address, just return a
  69            zero-length one.  */
  70         {
  71           buf = (char *)addr;
  72           buflen = 0;
  73           err = 0;
  74         }
  75
  76       if (err)
  77         {
  78           __mach_port_deallocate (__mach_task_self (), addrport);
  79           return __hurd_sockfail (fd, flags, err);
  80         }
  81
  82       if (*addr_len > buflen)
  83         *addr_len = buflen;
  84
  85       if (buf != (char *) addr)
  86         {
  87           memcpy (addr, buf, *addr_len);
  88           __vm_deallocate (__mach_task_self (), (vm_address_t) buf, buflen);
  89         }
  90
  91       if (buflen > 0)
  92         addr->sa_family = type;
  93     }
  94   else if (addr_len != NULL)
  95     *addr_len = 0;
  96
  97   if (MACH_PORT_VALID (addrport))
  98     __mach_port_deallocate (__mach_task_self (), addrport);
  99
 100   /* Toss control data; we don't care.  */
 101   __vm_deallocate (__mach_task_self (), (vm_address_t) cdata, clen);
 102
 103   if (bufp != buf)
 104     {
 105       memcpy (buf, bufp, nread);
 106       __vm_deallocate (__mach_task_self (), (vm_address_t) bufp, nread);
 107     }
 108
 109   return nread;
 110 }
 111
 112 weak_alias (__recvfrom, recvfrom)