| xf.li | bfc6e71 | 2025-02-07 01:54:34 -0800 | [diff] [blame^] | 1 | /* Copyright (C) 1991-2016 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | |
| 4 | The GNU C Library is free software; you can redistribute it and/or |
| 5 | modify it under the terms of the GNU Lesser General Public |
| 6 | License as published by the Free Software Foundation; either |
| 7 | version 2.1 of the License, or (at your option) any later version. |
| 8 | |
| 9 | The GNU C Library is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | Lesser General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU Lesser General Public |
| 15 | License along with the GNU C Library; if not, see |
| 16 | <http://www.gnu.org/licenses/>. */ |
| 17 | |
| 18 | #include <unistd.h> |
| 19 | #include <hurd.h> |
| 20 | #include <hurd/port.h> |
| 21 | #include <hurd/id.h> |
| 22 | #include <hurd/lookup.h> |
| 23 | #include <fcntl.h> |
| 24 | |
| 25 | /* Test for access to FILE by our real user and group IDs. */ |
| 26 | int |
| 27 | __access (const char *file, int type) |
| 28 | { |
| 29 | error_t err; |
| 30 | file_t rcrdir, rcwdir, io; |
| 31 | int flags, allowed; |
| 32 | |
| 33 | error_t reauthenticate (int which, file_t *result) |
| 34 | { |
| 35 | /* Get a port to our root directory, authenticated with the real IDs. */ |
| 36 | error_t err; |
| 37 | mach_port_t ref; |
| 38 | ref = __mach_reply_port (); |
| 39 | err = HURD_PORT_USE |
| 40 | (&_hurd_ports[which], |
| 41 | ({ |
| 42 | err = __io_reauthenticate (port, ref, MACH_MSG_TYPE_MAKE_SEND); |
| 43 | if (!err) |
| 44 | err = __auth_user_authenticate (_hurd_id.rid_auth, |
| 45 | ref, MACH_MSG_TYPE_MAKE_SEND, |
| 46 | result); |
| 47 | err; |
| 48 | })); |
| 49 | __mach_port_destroy (__mach_task_self (), ref); |
| 50 | return err; |
| 51 | } |
| 52 | |
| 53 | error_t init_port (int which, error_t (*operate) (mach_port_t)) |
| 54 | { |
| 55 | switch (which) |
| 56 | { |
| 57 | case INIT_PORT_AUTH: |
| 58 | return (*operate) (_hurd_id.rid_auth); |
| 59 | case INIT_PORT_CRDIR: |
| 60 | return (reauthenticate (INIT_PORT_CRDIR, &rcrdir) ?: |
| 61 | (*operate) (rcrdir)); |
| 62 | case INIT_PORT_CWDIR: |
| 63 | return (reauthenticate (INIT_PORT_CWDIR, &rcwdir) ?: |
| 64 | (*operate) (rcwdir)); |
| 65 | default: |
| 66 | return _hurd_ports_use (which, operate); |
| 67 | } |
| 68 | } |
| 69 | |
| 70 | rcrdir = rcwdir = MACH_PORT_NULL; |
| 71 | |
| 72 | HURD_CRITICAL_BEGIN; |
| 73 | |
| 74 | __mutex_lock (&_hurd_id.lock); |
| 75 | /* Get _hurd_id up to date. */ |
| 76 | if (err = _hurd_check_ids ()) |
| 77 | goto lose; |
| 78 | |
| 79 | if (_hurd_id.rid_auth == MACH_PORT_NULL) |
| 80 | { |
| 81 | /* Set up _hurd_id.rid_auth. This is a special auth server port |
| 82 | which uses the real uid and gid (the first aux uid and gid) as |
| 83 | the only effective uid and gid. */ |
| 84 | |
| 85 | if (_hurd_id.aux.nuids < 1 || _hurd_id.aux.ngids < 1) |
| 86 | { |
| 87 | /* We do not have a real UID and GID. Lose, lose, lose! */ |
| 88 | err = EGRATUITOUS; |
| 89 | goto lose; |
| 90 | } |
| 91 | |
| 92 | /* Create a new auth port using our real UID and GID (the first |
| 93 | auxiliary UID and GID) as the only effective IDs. */ |
| 94 | if (err = __USEPORT (AUTH, |
| 95 | __auth_makeauth (port, |
| 96 | NULL, MACH_MSG_TYPE_COPY_SEND, 0, |
| 97 | _hurd_id.aux.uids, 1, |
| 98 | _hurd_id.aux.uids, |
| 99 | _hurd_id.aux.nuids, |
| 100 | _hurd_id.aux.gids, 1, |
| 101 | _hurd_id.aux.gids, |
| 102 | _hurd_id.aux.ngids, |
| 103 | &_hurd_id.rid_auth))) |
| 104 | goto lose; |
| 105 | } |
| 106 | |
| 107 | if (!err) |
| 108 | /* Look up the file name using the modified init ports. */ |
| 109 | err = __hurd_file_name_lookup (&init_port, &__getdport, 0, |
| 110 | file, 0, 0, &io); |
| 111 | |
| 112 | /* We are done with _hurd_id.rid_auth now. */ |
| 113 | lose: |
| 114 | __mutex_unlock (&_hurd_id.lock); |
| 115 | |
| 116 | HURD_CRITICAL_END; |
| 117 | |
| 118 | if (rcrdir != MACH_PORT_NULL) |
| 119 | __mach_port_deallocate (__mach_task_self (), rcrdir); |
| 120 | if (rcwdir != MACH_PORT_NULL) |
| 121 | __mach_port_deallocate (__mach_task_self (), rcwdir); |
| 122 | if (err) |
| 123 | return __hurd_fail (err); |
| 124 | |
| 125 | /* Find out what types of access we are allowed to this file. */ |
| 126 | err = __file_check_access (io, &allowed); |
| 127 | __mach_port_deallocate (__mach_task_self (), io); |
| 128 | if (err) |
| 129 | return __hurd_fail (err); |
| 130 | |
| 131 | flags = 0; |
| 132 | if (type & R_OK) |
| 133 | flags |= O_READ; |
| 134 | if (type & W_OK) |
| 135 | flags |= O_WRITE; |
| 136 | if (type & X_OK) |
| 137 | flags |= O_EXEC; |
| 138 | |
| 139 | if (flags & ~allowed) |
| 140 | /* We are not allowed all the requested types of access. */ |
| 141 | return __hurd_fail (EACCES); |
| 142 | |
| 143 | return 0; |
| 144 | } |
| 145 | |
| 146 | weak_alias (__access, access) |