| 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 <sys/types.h> |
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| 22 | #include <hurd/id.h> |
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| 23 | #include <string.h> |
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| 24 | |
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| 25 | /* Set the effective user ID of the calling process to GID. */ |
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| 26 | int |
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| 27 | setegid (gid_t gid) |
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| 28 | { |
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| 29 | auth_t newauth; |
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| 30 | error_t err; |
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| 31 | |
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| 32 | retry: |
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| 33 | HURD_CRITICAL_BEGIN; |
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| 34 | __mutex_lock (&_hurd_id.lock); |
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| 35 | err = _hurd_check_ids (); |
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| 36 | |
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| 37 | if (!err) |
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| 38 | { |
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| 39 | /* Make a new auth handle which has EGID as the first element in the |
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| 40 | list of effective gids. */ |
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| 41 | |
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| 42 | if (_hurd_id.gen.ngids > 0) |
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| 43 | { |
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| 44 | _hurd_id.gen.gids[0] = gid; |
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| 45 | _hurd_id.valid = 0; |
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| 46 | } |
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| 47 | |
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| 48 | err = __USEPORT (AUTH, __auth_makeauth |
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| 49 | (port, NULL, MACH_MSG_TYPE_COPY_SEND, 0, |
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| 50 | _hurd_id.gen.uids, _hurd_id.gen.nuids, |
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| 51 | _hurd_id.aux.uids, _hurd_id.aux.nuids, |
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| 52 | _hurd_id.gen.ngids ? _hurd_id.gen.gids : &gid, |
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| 53 | _hurd_id.gen.ngids ?: 1, |
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| 54 | _hurd_id.aux.gids, _hurd_id.aux.ngids, |
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| 55 | &newauth)); |
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| 56 | } |
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| 57 | __mutex_unlock (&_hurd_id.lock); |
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| 58 | HURD_CRITICAL_END; |
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| 59 | if (err == EINTR) |
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| 60 | /* Got a signal while inside an RPC of the critical section, retry again */ |
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| 61 | goto retry; |
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| 62 | |
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| 63 | if (err) |
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| 64 | return __hurd_fail (err); |
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| 65 | |
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| 66 | /* Install the new handle and reauthenticate everything. */ |
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| 67 | err = __setauth (newauth); |
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| 68 | __mach_port_deallocate (__mach_task_self (), newauth); |
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| 69 | return err; |
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| 70 | } |
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| 71 | libc_hidden_def (setegid) |
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| 72 | |
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