lib/sh/netconn.c

   1 /* netconn.c -- is a particular file descriptor a network connection?. */
   2
   3 /* Copyright (C) 2002-2005 Free Software Foundation, Inc.
   4
   5    This file is part of GNU Bash, the Bourne Again SHell.
   6
   7    Bash is free software: you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation, either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    Bash is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include <config.h>
  22
  23 #include <bashtypes.h>
  24 #if ! defined(_MINIX) && defined (HAVE_SYS_FILE_H)
  25 #  include <sys/file.h>
  26 #endif
  27 #include <posixstat.h>
  28 #include <filecntl.h>
  29
  30 #include <errno.h>
  31
  32 #if defined (HAVE_UNISTD_H)
  33 #  include <unistd.h>
  34 #endif
  35
  36 /* The second and subsequent conditions must match those used to decide
  37    whether or not to call getpeername() in isnetconn(). */
  38 #if defined (HAVE_SYS_SOCKET_H) && defined (HAVE_GETPEERNAME) && !defined (SVR4_2)
  39 #  include <sys/socket.h>
  40 #endif
  41
  42 /* Is FD a socket or network connection? */
  43 int
  44 isnetconn (fd)
  45      int fd;
  46 {
  47 #if defined (HAVE_SYS_SOCKET_H) && defined (HAVE_GETPEERNAME) && !defined (SVR4_2) && !defined (__BEOS__)
  48   int rv;
  49   socklen_t l;
  50   struct sockaddr sa;
  51
  52   l = sizeof(sa);
  53   rv = getpeername(fd, &sa, &l);
  54   /* Posix.2 says getpeername can return these errors. */
  55   return ((rv < 0 && (errno == ENOTSOCK || errno == ENOTCONN || errno == EINVAL || errno == EBADF)) ? 0 : 1);
  56 #else /* !HAVE_GETPEERNAME || SVR4_2 || __BEOS__ */
  57 #  if defined (SVR4) || defined (SVR4_2)
  58   /* Sockets on SVR4 and SVR4.2 are character special (streams) devices. */
  59   struct stat sb;
  60
  61   if (isatty (fd))
  62     return (0);
  63   if (fstat (fd, &sb) < 0)
  64     return (0);
  65 #    if defined (S_ISFIFO)
  66   if (S_ISFIFO (sb.st_mode))
  67     return (0);
  68 #    endif /* S_ISFIFO */
  69   return (S_ISCHR (sb.st_mode));
  70 #  else /* !SVR4 && !SVR4_2 */
  71 #    if defined (S_ISSOCK) && !defined (__BEOS__)
  72   struct stat sb;
  73
  74   if (fstat (fd, &sb) < 0)
  75     return (0);
  76   return (S_ISSOCK (sb.st_mode));
  77 #    else /* !S_ISSOCK || __BEOS__ */
  78   return (0);
  79 #    endif /* !S_ISSOCK || __BEOS__ */
  80 #  endif /* !SVR4 && !SVR4_2 */
  81 #endif /* !HAVE_GETPEERNAME || SVR4_2 || __BEOS__ */
  82 }