| 1 | /* Miscellaneous definitions for libresolv. |
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| 2 | Copyright (C) 1995-2022 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, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | /* |
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| 20 | * Copyright (c) 1995-1999 by Internet Software Consortium. |
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| 21 | * |
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| 22 | * Permission to use, copy, modify, and distribute this software for any |
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| 23 | * purpose with or without fee is hereby granted, provided that the above |
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| 24 | * copyright notice and this permission notice appear in all copies. |
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| 25 | * |
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| 26 | * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS |
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| 27 | * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES |
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| 28 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE |
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| 29 | * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL |
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| 30 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR |
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| 31 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS |
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| 32 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS |
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| 33 | * SOFTWARE. |
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| 34 | */ |
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| 35 | |
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| 36 | #include <resolv.h> |
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| 37 | |
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| 38 | /* This function belongs to libresolv, which is why it is not included |
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| 39 | in res-close.c. */ |
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| 40 | void |
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| 41 | __res_close (void) |
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| 42 | { |
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| 43 | /* Some programs call res_close before res_init. Since _res._vcsock |
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| 44 | isn't explicitly initialized, these means that we could call |
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| 45 | close (0), which might lead to some security problems. Therefore |
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| 46 | we check if res_init was called before by looking at the RES_INIT |
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| 47 | bit in _res.options. If it hasn't been set we bail out |
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| 48 | early. */ |
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| 49 | if ((_res.options & RES_INIT) == 0) |
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| 50 | return; |
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| 51 | /* We don't free the name server addresses because we never did it |
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| 52 | and it would be done implicitly on shutdown. */ |
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| 53 | __res_iclose (statp: &_res, false); |
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| 54 | } |
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| 55 | |
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