recvfrom.c

Glibc 2.3.2源代码(解压后有100多M)

/* Copyright (C) 1994, 1997, 1999, 2001, 2002 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <errno.h>
#include <string.h>
#include <sys/socket.h>
#include <hurd.h>
#include <hurd/fd.h>
#include <hurd/socket.h>

/* Read N bytes into BUF through socket FD.
   If ADDR is not NULL, fill in *ADDR_LEN bytes of it with tha address of
   the sender, and store the actual size of the address in *ADDR_LEN.
   Returns the number of bytes read or -1 for errors.  */
ssize_t
__recvfrom (fd, buf, n, flags, addrarg, addr_len)
     int fd;
     void *buf;
     size_t n;
     int flags;
     __SOCKADDR_ARG addrarg;
     socklen_t *addr_len;
{
  error_t err;
  mach_port_t addrport;
  char *bufp = buf;
  mach_msg_type_number_t nread = n;
  mach_port_t *ports;
  mach_msg_type_number_t nports;
  char *cdata = NULL;
  mach_msg_type_number_t clen = 0;
  struct sockaddr *addr = addrarg.__sockaddr__;

  if (err = HURD_DPORT_USE (fd, __socket_recv (port, &addrport,
					       flags, &bufp, &nread,
					       &ports, &nports,
					       &cdata, &clen,
					       &flags,
					       n)))
    return __hurd_dfail (fd, err);

  /* Get address data for the returned address port if requested.  */
  if (addr != NULL)
    {
      char *buf = (char *) addr;
      mach_msg_type_number_t buflen = *addr_len;
      int type;

      err = __socket_whatis_address (addrport, &type, &buf, &buflen);
      if (err == EOPNOTSUPP)
	/* If the protocol server can't tell us the address, just return a
	   zero-length one.  */
	{
	  buf = (char *)addr;
	  buflen = 0;
	  err = 0;
	}

      if (err)
	{
	  __mach_port_deallocate (__mach_task_self (), addrport);
	  return __hurd_dfail (fd, err);
	}
      
      if (*addr_len > buflen)
	*addr_len = buflen;

      if (buf != (char *) addr)
	{
	  memcpy (addr, buf, *addr_len);
	  __vm_deallocate (__mach_task_self (), (vm_address_t) buf, buflen);
	}

      if (buflen > 0)
	addr->sa_family = type;
    }

  __mach_port_deallocate (__mach_task_self (), addrport);

  /* Toss control data; we don't care.  */
  __vm_deallocate (__mach_task_self (), (vm_address_t) cdata, clen);

  if (bufp != buf)
    {
      memcpy (buf, bufp, nread);
      __vm_deallocate (__mach_task_self (), (vm_address_t) bufp, nread);
    }

  return nread;
}

weak_alias (__recvfrom, recvfrom)