mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-19 03:20:05 +00:00
113 lines
3.3 KiB
C
113 lines
3.3 KiB
C
/* Copyright (C) 1999, 2001 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 <assert.h>
|
|
#include <errno.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <sys/socket.h>
|
|
|
|
/* Return a socket of any type. The socket can be used in subsequent
|
|
ioctl calls to talk to the kernel. */
|
|
int internal_function
|
|
__opensock (void)
|
|
{
|
|
static int last_family; /* Available socket family we will use. */
|
|
static int last_type;
|
|
static const struct
|
|
{
|
|
int family;
|
|
const char procname[15];
|
|
} afs[] =
|
|
{
|
|
{ AF_UNIX, "net/unix" },
|
|
{ AF_INET, "" },
|
|
{ AF_INET6, "net/if_inet6" },
|
|
{ AF_AX25, "net/ax25" },
|
|
{ AF_NETROM, "net/nr" },
|
|
{ AF_ROSE, "net/rose" },
|
|
{ AF_IPX, "net/ipx" },
|
|
{ AF_APPLETALK, "net/appletalk" },
|
|
{ AF_ECONET, "sys/net/econet" },
|
|
{ AF_ASH, "sys/net/ash" },
|
|
{ AF_X25, "net/x25" }
|
|
};
|
|
#define nafs (sizeof (afs) / sizeof (afs[0]))
|
|
char fname[sizeof "/proc/" + 14];
|
|
int result;
|
|
int has_proc;
|
|
int cnt;
|
|
|
|
/* We already know which family to use from the last call. Use it
|
|
again. */
|
|
if (last_family != 0)
|
|
{
|
|
assert (last_type != 0);
|
|
|
|
result = socket (last_family, last_type, 0);
|
|
if (result != -1 || errno != EAFNOSUPPORT)
|
|
/* Maybe the socket type isn't supported anymore (module is
|
|
unloaded). In this case again try to find the type. */
|
|
return result;
|
|
|
|
/* Reset the values. They seem not valid anymore. */
|
|
last_family = 0;
|
|
last_type = 0;
|
|
}
|
|
|
|
/* Check whether the /proc filesystem is available. */
|
|
has_proc = __access ("/proc/net", R_OK) != -1;
|
|
strcpy (fname, "/proc/");
|
|
|
|
/* Iterate over the interface families and find one which is
|
|
available. */
|
|
for (cnt = 0; cnt < nafs; ++cnt)
|
|
{
|
|
int type = SOCK_DGRAM;
|
|
|
|
if (has_proc && afs[cnt].procname[0] != '\0')
|
|
{
|
|
strcpy (fname + 6, afs[cnt].procname);
|
|
if (__access (fname, R_OK) == -1)
|
|
/* The /proc entry is not available. I.e., we cannot
|
|
create a socket of this type (without loading the
|
|
module). Don't look for it since this might trigger
|
|
loading the module. */
|
|
continue;
|
|
}
|
|
|
|
if (afs[cnt].family == AF_NETROM || afs[cnt].family == AF_X25)
|
|
type = SOCK_SEQPACKET;
|
|
|
|
result = socket (afs[cnt].family, type, 0);
|
|
if (result != -1)
|
|
{
|
|
/* Found an available family. */
|
|
last_type = type;
|
|
last_family = afs[cnt].family;
|
|
return result;
|
|
}
|
|
}
|
|
|
|
/* None of the protocol families is available. It is unclear what kind
|
|
of error is returned. ENOENT seems like a reasonable choice. */
|
|
__set_errno (ENOENT);
|
|
return -1;
|
|
}
|