| 1 | /* Copyright (C) 1991-2022 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 <string.h> |
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| 19 | #include <unistd.h> |
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| 20 | |
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| 21 | #include <hurd.h> |
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| 22 | #include <hurd/port.h> |
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| 23 | |
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| 24 | /* Make PATH be the root directory (the starting point for absolute |
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| 25 | paths). Note that while on traditional UNIX systems this call is |
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| 26 | restricted to the super-user, it isn't on the Hurd. */ |
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| 27 | int |
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| 28 | chroot (const char *path) |
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| 29 | { |
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| 30 | const char *lookup; |
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| 31 | size_t len; |
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| 32 | file_t dir, root; |
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| 33 | error_t err; |
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| 34 | |
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| 35 | /* Append trailing "/." to directory name to force ENOTDIR if it's not a |
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| 36 | directory and EACCES if we don't have search permission. */ |
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| 37 | len = strlen (path); |
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| 38 | if (len >= 2 && path[len - 2] == '/' && path[len - 1] == '.') |
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| 39 | lookup = path; |
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| 40 | else if (len == 0) |
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| 41 | /* Special-case empty file name according to POSIX. */ |
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| 42 | return __hurd_fail (ENOENT); |
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| 43 | else |
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| 44 | { |
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| 45 | char *n = alloca (len + 3); |
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| 46 | memcpy (n, path, len); |
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| 47 | n[len] = '/'; |
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| 48 | n[len + 1] = '.'; |
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| 49 | n[len + 2] = '\0'; |
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| 50 | lookup = n; |
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| 51 | } |
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| 52 | |
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| 53 | dir = __file_name_lookup (lookup, 0, 0); |
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| 54 | if (dir == MACH_PORT_NULL) |
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| 55 | return -1; |
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| 56 | |
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| 57 | /* Prevent going through DIR's .. */ |
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| 58 | err = __file_reparent (dir, MACH_PORT_NULL, &root); |
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| 59 | __mach_port_deallocate (__mach_task_self (), dir); |
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| 60 | if (err) |
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| 61 | return __hurd_fail (err); |
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| 62 | |
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| 63 | _hurd_port_set (&_hurd_ports[INIT_PORT_CRDIR], root); |
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| 64 | return 0; |
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| 65 | } |
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| 66 | |
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