| 1 | /* Copyright (C) 1993-2022 Free Software Foundation, Inc. |
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| 2 | This file is part of the GNU C Library. |
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| 3 | |
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| 4 | The GNU C Library is free software; you can redistribute it and/or |
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| 5 | modify it under the terms of the GNU Lesser General Public |
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| 6 | License as published by the Free Software Foundation; either |
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| 7 | version 2.1 of the License, or (at your option) any later version. |
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| 8 | |
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| 9 | The GNU C Library is distributed in the hope that it will be useful, |
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| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 12 | Lesser General Public License for more details. |
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| 13 | |
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| 14 | You should have received a copy of the GNU Lesser General Public |
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| 15 | License along with the GNU C Library; if not, see |
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| 16 | <https://www.gnu.org/licenses/>. */ |
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| 17 | |
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| 18 | #include <errno.h> |
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| 19 | #include <unistd.h> |
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| 20 | #include <hurd.h> |
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| 21 | #include <hurd/id.h> |
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| 22 | #include <string.h> |
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| 23 | |
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| 24 | int |
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| 25 | __getgroups (int n, gid_t *gidset) |
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| 26 | { |
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| 27 | error_t err; |
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| 28 | int ngids; |
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| 29 | void *crit; |
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| 30 | |
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| 31 | if (n < 0) |
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| 32 | return __hurd_fail (EINVAL); |
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| 33 | |
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| 34 | retry: |
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| 35 | crit = _hurd_critical_section_lock (); |
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| 36 | __mutex_lock (&_hurd_id.lock); |
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| 37 | |
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| 38 | if (err = _hurd_check_ids ()) |
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| 39 | { |
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| 40 | __mutex_unlock (&_hurd_id.lock); |
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| 41 | _hurd_critical_section_unlock (crit); |
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| 42 | if (err == EINTR) |
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| 43 | /* Got a signal while inside an RPC of the critical section, retry again */ |
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| 44 | goto retry; |
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| 45 | return __hurd_fail (err); |
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| 46 | } |
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| 47 | |
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| 48 | ngids = _hurd_id.gen.ngids; |
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| 49 | |
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| 50 | if (n != 0) |
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| 51 | { |
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| 52 | /* Copy the gids onto stack storage and then release the idlock. */ |
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| 53 | gid_t gids[ngids]; |
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| 54 | memcpy (gids, _hurd_id.gen.gids, sizeof (gids)); |
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| 55 | __mutex_unlock (&_hurd_id.lock); |
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| 56 | _hurd_critical_section_unlock (crit); |
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| 57 | |
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| 58 | /* Now that the lock is released, we can safely copy the |
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| 59 | group set into the user's array, which might fault. */ |
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| 60 | if (ngids > n) |
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| 61 | return __hurd_fail (EINVAL); |
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| 62 | memcpy (gidset, gids, ngids * sizeof (gid_t)); |
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| 63 | } |
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| 64 | else |
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| 65 | { |
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| 66 | __mutex_unlock (&_hurd_id.lock); |
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| 67 | _hurd_critical_section_unlock (crit); |
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| 68 | } |
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| 69 | |
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| 70 | return ngids; |
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| 71 | } |
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| 72 | |
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| 73 | weak_alias (__getgroups, getgroups) |
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| 74 | |
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