1 /* Copyright (C) 1999-2014 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
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.
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.
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 <http://www.gnu.org/licenses/>. */
23 #include <sys/socket.h>
24 #include <kernel-features.h>
26 /* Return a socket of any type. The socket can be used in subsequent
27 ioctl calls to talk to the kernel. */
31 static int last_family
; /* Available socket family we will use. */
36 const char procname
[15];
39 { AF_UNIX
, "net/unix" },
41 { AF_INET6
, "net/if_inet6" },
42 { AF_AX25
, "net/ax25" },
43 { AF_NETROM
, "net/nr" },
44 { AF_ROSE
, "net/rose" },
45 { AF_IPX
, "net/ipx" },
46 { AF_APPLETALK
, "net/appletalk" },
47 { AF_ECONET
, "sys/net/econet" },
48 { AF_ASH
, "sys/net/ash" },
49 { AF_X25
, "net/x25" },
51 { AF_IUCV
, "net/iucv" }
54 #define nafs (sizeof (afs) / sizeof (afs[0]))
55 char fname
[sizeof "/proc/" + 14];
60 /* We already know which family to use from the last call. Use it
64 assert (last_type
!= 0);
67 # ifndef __ASSUME_SOCK_CLOEXEC
68 if (__have_sock_cloexec
>= 0)
71 result
= __socket (last_family
, last_type
| SOCK_CLOEXEC
, 0);
72 # ifndef __ASSUME_SOCK_CLOEXEC
73 if (__have_sock_cloexec
== 0)
74 __have_sock_cloexec
= result
!= -1 || errno
!= EINVAL
? 1 : -1;
78 #ifndef __ASSUME_SOCK_CLOEXEC
80 if (__have_sock_cloexec
< 0)
82 result
= __socket (last_family
, last_type
, 0);
84 if (result
!= -1 || errno
!= EAFNOSUPPORT
)
85 /* Maybe the socket type isn't supported anymore (module is
86 unloaded). In this case again try to find the type. */
89 /* Reset the values. They seem not valid anymore. */
94 /* Check whether the /proc filesystem is available. */
95 has_proc
= __access ("/proc/net", R_OK
) != -1;
96 strcpy (fname
, "/proc/");
98 /* Iterate over the interface families and find one which is
100 for (cnt
= 0; cnt
< nafs
; ++cnt
)
102 int type
= SOCK_DGRAM
;
104 if (has_proc
&& afs
[cnt
].procname
[0] != '\0')
106 strcpy (fname
+ 6, afs
[cnt
].procname
);
107 if (__access (fname
, R_OK
) == -1)
108 /* The /proc entry is not available. I.e., we cannot
109 create a socket of this type (without loading the
110 module). Don't look for it since this might trigger
111 loading the module. */
115 if (afs
[cnt
].family
== AF_NETROM
|| afs
[cnt
].family
== AF_X25
)
116 type
= SOCK_SEQPACKET
;
119 # ifndef __ASSUME_SOCK_CLOEXEC
120 if (__have_sock_cloexec
>= 0)
123 result
= __socket (afs
[cnt
].family
, type
| SOCK_CLOEXEC
, 0);
124 # ifndef __ASSUME_SOCK_CLOEXEC
125 if (__have_sock_cloexec
== 0)
126 __have_sock_cloexec
= result
!= -1 || errno
!= EINVAL
? 1 : -1;
130 #ifndef __ASSUME_SOCK_CLOEXEC
132 if (__have_sock_cloexec
< 0)
134 result
= __socket (afs
[cnt
].family
, type
, 0);
138 /* Found an available family. */
140 last_family
= afs
[cnt
].family
;
145 /* None of the protocol families is available. It is unclear what kind
146 of error is returned. ENOENT seems like a reasonable choice. */
147 __set_errno (ENOENT
);