| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* Copyright (C) 1999-2015 Free Software Foundation, Inc. |
| 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 |
| 16 | License along with the GNU C Library; if not, see |
| 17 | <http://www.gnu.org/licenses/>. */ |
| 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 | rq_len = RQ_IFS * sizeof (struct ifreq) / 2; /* Doubled in the loop. */ |
| 42 | do |
| 43 | { |
| 44 | ifc.ifc_len = rq_len *= 2; |
| 45 | void *newp = realloc (ifc.ifc_buf, ifc.ifc_len); |
| 46 | if (newp == NULL || __ioctl (fd, SIOCGIFCONF, &ifc) < 0) |
| 47 | { |
| 48 | free (ifc.ifc_buf); |
| 49 | |
| 50 | if (fd != sockfd) |
| 51 | __close (fd); |
| 52 | *num_ifs = 0; |
| 53 | *ifreqs = NULL; |
| 54 | return; |
| 55 | } |
| 56 | ifc.ifc_buf = newp; |
| 57 | } |
| 58 | while (rq_len < sizeof (struct ifreq) + ifc.ifc_len); |
| 59 | |
| 60 | if (fd != sockfd) |
| 61 | __close (fd); |
| 62 | |
| 63 | #ifdef _HAVE_SA_LEN |
| 64 | struct ifreq *ifr = *ifreqs; |
| 65 | nifs = 0; |
| 66 | while ((char *) ifr < ifc.ifc_buf + ifc.ifc_len) |
| 67 | { |
| 68 | ++nifs; |
| 69 | ifr = __if_nextreq (ifr); |
| 70 | if (ifr == NULL) |
| 71 | break; |
| 72 | } |
| 73 | #else |
| 74 | nifs = ifc.ifc_len / sizeof (struct ifreq); |
| 75 | #endif |
| 76 | |
| 77 | *num_ifs = nifs; |
| 78 | *ifreqs = realloc (ifc.ifc_buf, nifs * sizeof (struct ifreq)); |
| 79 | } |