1  /* Copyright (C) 1994-2023 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)