| 1 | /* ifaddrs.h -- declarations for getting network interface addresses |
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| 2 | Copyright (C) 2002 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, write to the Free |
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| 17 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
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| 18 | 02111-1307 USA. */ |
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| 19 | |
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| 20 | #ifndef _IFADDRS_H |
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| 21 | #define _IFADDRS_H 1 |
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| 22 | |
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| 23 | #include <features.h> |
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| 24 | #include <sys/socket.h> |
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| 25 | |
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| 26 | __BEGIN_DECLS |
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| 27 | |
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| 28 | /* The `getifaddrs' function generates a linked list of these structures. |
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| 29 | Each element of the list describes one network interface. */ |
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| 30 | struct ifaddrs |
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| 31 | { |
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| 32 | struct ifaddrs *ifa_next; /* Pointer to the next structure. */ |
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| 33 | |
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| 34 | char *ifa_name; /* Name of this network interface. */ |
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| 35 | unsigned int ifa_flags; /* Flags as from SIOCGIFFLAGS ioctl. */ |
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| 36 | |
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| 37 | struct sockaddr *ifa_addr; /* Network address of this interface. */ |
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| 38 | struct sockaddr *ifa_netmask; /* Netmask of this interface. */ |
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| 39 | union |
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| 40 | { |
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| 41 | /* At most one of the following two is valid. If the IFF_BROADCAST |
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| 42 | bit is set in `ifa_flags', then `ifa_broadaddr' is valid. If the |
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| 43 | IFF_POINTOPOINT bit is set, then `ifa_dstaddr' is valid. |
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| 44 | It is never the case that both these bits are set at once. */ |
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| 45 | struct sockaddr *ifu_broadaddr; /* Broadcast address of this interface. */ |
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| 46 | struct sockaddr *ifu_dstaddr; /* Point-to-point destination address. */ |
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| 47 | } ifa_ifu; |
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| 48 | /* These very same macros are defined by <net/if.h> for `struct ifaddr'. |
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| 49 | So if they are defined already, the existing definitions will be fine. */ |
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| 50 | # ifndef ifa_broadaddr |
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| 51 | # define ifa_broadaddr ifa_ifu.ifu_broadaddr |
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| 52 | # endif |
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| 53 | # ifndef ifa_dstaddr |
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| 54 | # define ifa_dstaddr ifa_ifu.ifu_dstaddr |
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| 55 | # endif |
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| 56 | |
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| 57 | void *ifa_data; /* Address-specific data (may be unused). */ |
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| 58 | }; |
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| 59 | |
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| 60 | |
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| 61 | /* Create a linked list of `struct ifaddrs' structures, one for each |
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| 62 | network interface on the host machine. If successful, store the |
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| 63 | list in *IFAP and return 0. On errors, return -1 and set `errno'. |
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| 64 | |
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| 65 | The storage returned in *IFAP is allocated dynamically and can |
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| 66 | only be properly freed by passing it to `freeifaddrs'. */ |
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| 67 | extern int getifaddrs (struct ifaddrs **__ifap) __THROW; |
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| 68 | |
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| 69 | /* Reclaim the storage allocated by a previous `getifaddrs' call. */ |
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| 70 | extern void freeifaddrs (struct ifaddrs *__ifa) __THROW; |
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| 71 | |
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| 72 | __END_DECLS |
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| 73 | |
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| 74 | #endif /* ifaddrs.h */ |
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