]>
Commit | Line | Data |
---|---|---|
b168057a | 1 | /* Copyright (C) 1999-2015 Free Software Foundation, Inc. |
9c7ff11a UD |
2 | This file is part of the GNU C Library. |
3 | Contributed by Andreas Jaeger <aj@suse.de>. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
9c7ff11a UD |
18 | |
19 | #include "ifreq.h" | |
20 | ||
21 | ||
22 | void | |
23 | __ifreq (struct ifreq **ifreqs, int *num_ifs, int sockfd) | |
24 | { | |
25 | int fd = sockfd; | |
26 | struct ifconf ifc; | |
27 | int rq_len; | |
28 | int nifs; | |
29 | # define RQ_IFS 4 | |
30 | ||
31 | if (fd < 0) | |
32 | fd = __opensock (); | |
33 | if (fd < 0) | |
34 | { | |
35 | *num_ifs = 0; | |
36 | *ifreqs = NULL; | |
37 | return; | |
38 | } | |
39 | ||
40 | ifc.ifc_buf = NULL; | |
41 | ||
42 | /* We may be able to get the needed buffer size directly, rather than | |
43 | guessing. */ | |
ffb7875d JM |
44 | ifc.ifc_buf = NULL; |
45 | ifc.ifc_len = 0; | |
46 | if (__ioctl (fd, SIOCGIFCONF, &ifc) < 0 || ifc.ifc_len == 0) | |
9c7ff11a | 47 | rq_len = RQ_IFS * sizeof (struct ifreq); |
ffb7875d JM |
48 | else |
49 | rq_len = ifc.ifc_len; | |
9c7ff11a UD |
50 | |
51 | /* Read all the interfaces out of the kernel. */ | |
ffb7875d JM |
52 | ifc.ifc_len = rq_len; |
53 | void *newp = realloc (ifc.ifc_buf, ifc.ifc_len); | |
54 | if (newp == NULL | |
55 | || (ifc.ifc_buf = newp, __ioctl (fd, SIOCGIFCONF, &ifc)) < 0) | |
9c7ff11a | 56 | { |
ffb7875d | 57 | free (ifc.ifc_buf); |
9c7ff11a | 58 | |
ffb7875d JM |
59 | if (fd != sockfd) |
60 | __close (fd); | |
9c7ff11a | 61 | |
ffb7875d JM |
62 | *num_ifs = 0; |
63 | *ifreqs = NULL; | |
64 | return; | |
9c7ff11a UD |
65 | } |
66 | ||
67 | nifs = ifc.ifc_len / sizeof (struct ifreq); | |
68 | ||
69 | if (fd != sockfd) | |
70 | __close (fd); | |
71 | ||
72 | *num_ifs = nifs; | |
73 | *ifreqs = realloc (ifc.ifc_buf, nifs * sizeof (struct ifreq)); | |
74 | } |