| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* ifaddrs.h -- declarations for getting network interface addresses |
| 2 | Copyright (C) 2002-2016 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 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 | #ifndef _IFADDRS_H |
| 20 | #define _IFADDRS_H 1 |
| 21 | |
| 22 | #include <features.h> |
| 23 | #include <sys/socket.h> |
| 24 | |
| 25 | __BEGIN_DECLS |
| 26 | |
| 27 | /* The `getifaddrs' function generates a linked list of these structures. |
| 28 | Each element of the list describes one network interface. */ |
| 29 | struct ifaddrs |
| 30 | { |
| 31 | struct ifaddrs *ifa_next; /* Pointer to the next structure. */ |
| 32 | |
| 33 | char *ifa_name; /* Name of this network interface. */ |
| 34 | unsigned int ifa_flags; /* Flags as from SIOCGIFFLAGS ioctl. */ |
| 35 | |
| 36 | struct sockaddr *ifa_addr; /* Network address of this interface. */ |
| 37 | struct sockaddr *ifa_netmask; /* Netmask of this interface. */ |
| 38 | union |
| 39 | { |
| 40 | /* At most one of the following two is valid. If the IFF_BROADCAST |
| 41 | bit is set in `ifa_flags', then `ifa_broadaddr' is valid. If the |
| 42 | IFF_POINTOPOINT bit is set, then `ifa_dstaddr' is valid. |
| 43 | It is never the case that both these bits are set at once. */ |
| 44 | struct sockaddr *ifu_broadaddr; /* Broadcast address of this interface. */ |
| 45 | struct sockaddr *ifu_dstaddr; /* Point-to-point destination address. */ |
| 46 | } ifa_ifu; |
| 47 | /* These very same macros are defined by <net/if.h> for `struct ifaddr'. |
| 48 | So if they are defined already, the existing definitions will be fine. */ |
| 49 | # ifndef ifa_broadaddr |
| 50 | # define ifa_broadaddr ifa_ifu.ifu_broadaddr |
| 51 | # endif |
| 52 | # ifndef ifa_dstaddr |
| 53 | # define ifa_dstaddr ifa_ifu.ifu_dstaddr |
| 54 | # endif |
| 55 | |
| 56 | void *ifa_data; /* Address-specific data (may be unused). */ |
| 57 | }; |
| 58 | |
| 59 | |
| 60 | /* Create a linked list of `struct ifaddrs' structures, one for each |
| 61 | network interface on the host machine. If successful, store the |
| 62 | list in *IFAP and return 0. On errors, return -1 and set `errno'. |
| 63 | |
| 64 | The storage returned in *IFAP is allocated dynamically and can |
| 65 | only be properly freed by passing it to `freeifaddrs'. */ |
| 66 | extern int getifaddrs (struct ifaddrs **__ifap) __THROW; |
| 67 | |
| 68 | /* Reclaim the storage allocated by a previous `getifaddrs' call. */ |
| 69 | extern void freeifaddrs (struct ifaddrs *__ifa) __THROW; |
| 70 | |
| 71 | __END_DECLS |
| 72 | |
| 73 | #endif /* ifaddrs.h */ |