xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [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 <hurd.h> |
| 19 | #include <hurd/term.h> |
| 20 | #include <hurd/fd.h> |
| 21 | #include <stdlib.h> |
| 22 | #include <stdio.h> |
| 23 | #include <fcntl.h> |
| 24 | #include <limits.h> |
| 25 | #include <cthreads.h> /* For `struct mutex'. */ |
| 26 | #include "set-hooks.h" |
| 27 | #include "hurdmalloc.h" /* XXX */ |
| 28 | |
| 29 | |
| 30 | struct mutex _hurd_dtable_lock = MUTEX_INITIALIZER; /* XXX ld bug; must init */ |
| 31 | struct hurd_fd **_hurd_dtable; |
| 32 | int _hurd_dtablesize; |
| 33 | |
| 34 | |
| 35 | DEFINE_HOOK (_hurd_fd_subinit, (void)); |
| 36 | |
| 37 | /* Initialize the file descriptor table at startup. */ |
| 38 | |
| 39 | static void |
| 40 | init_dtable (void) |
| 41 | { |
| 42 | int i; |
| 43 | |
| 44 | __mutex_init (&_hurd_dtable_lock); |
| 45 | |
| 46 | /* The initial size of the descriptor table is that of the passed-in |
| 47 | table. It will be expanded as necessary up to _hurd_dtable_rlimit. */ |
| 48 | _hurd_dtablesize = _hurd_init_dtablesize; |
| 49 | |
| 50 | /* Allocate the vector of pointers. */ |
| 51 | _hurd_dtable = malloc (_hurd_dtablesize * sizeof (*_hurd_dtable)); |
| 52 | if (_hurd_dtablesize != 0 && _hurd_dtable == NULL) |
| 53 | __libc_fatal ("hurd: Can't allocate file descriptor table\n"); |
| 54 | |
| 55 | /* Initialize the descriptor table. */ |
| 56 | for (i = 0; (unsigned int) i < _hurd_init_dtablesize; ++i) |
| 57 | { |
| 58 | if (_hurd_init_dtable[i] == MACH_PORT_NULL) |
| 59 | /* An unused descriptor is marked by a null pointer. */ |
| 60 | _hurd_dtable[i] = NULL; |
| 61 | else |
| 62 | { |
| 63 | /* Allocate a new file descriptor structure. */ |
| 64 | struct hurd_fd *new = malloc (sizeof (struct hurd_fd)); |
| 65 | if (new == NULL) |
| 66 | __libc_fatal ("hurd: Can't allocate initial file descriptors\n"); |
| 67 | |
| 68 | /* Initialize the port cells. */ |
| 69 | _hurd_port_init (&new->port, MACH_PORT_NULL); |
| 70 | _hurd_port_init (&new->ctty, MACH_PORT_NULL); |
| 71 | |
| 72 | /* Install the port in the descriptor. |
| 73 | This sets up all the ctty magic. */ |
| 74 | _hurd_port2fd (new, _hurd_init_dtable[i], 0); |
| 75 | |
| 76 | _hurd_dtable[i] = new; |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | /* Clear out the initial descriptor table. |
| 81 | Everything must use _hurd_dtable now. */ |
| 82 | __vm_deallocate (__mach_task_self (), |
| 83 | (vm_address_t) _hurd_init_dtable, |
| 84 | _hurd_init_dtablesize * sizeof (_hurd_init_dtable[0])); |
| 85 | _hurd_init_dtable = NULL; |
| 86 | _hurd_init_dtablesize = 0; |
| 87 | |
| 88 | /* Initialize the remaining empty slots in the table. */ |
| 89 | for (; i < _hurd_dtablesize; ++i) |
| 90 | _hurd_dtable[i] = NULL; |
| 91 | |
| 92 | /* Run things that want to run after the file descriptor table |
| 93 | is initialized. */ |
| 94 | RUN_HOOK (_hurd_fd_subinit, ()); |
| 95 | |
| 96 | (void) &init_dtable; /* Avoid "defined but not used" warning. */ |
| 97 | } |
| 98 | |
| 99 | text_set_element (_hurd_subinit, init_dtable); |
| 100 | |
| 101 | /* XXX when the linker supports it, the following functions should all be |
| 102 | elsewhere and just have text_set_elements here. */ |
| 103 | |
| 104 | /* Called by `getdport' to do its work. */ |
| 105 | |
| 106 | static file_t |
| 107 | get_dtable_port (int fd) |
| 108 | { |
| 109 | struct hurd_fd *d = _hurd_fd_get (fd); |
| 110 | file_t dport; |
| 111 | |
| 112 | if (!d) |
| 113 | return __hurd_fail (EBADF), MACH_PORT_NULL; |
| 114 | |
| 115 | HURD_CRITICAL_BEGIN; |
| 116 | |
| 117 | dport = HURD_PORT_USE (&d->port, |
| 118 | ({ |
| 119 | error_t err; |
| 120 | mach_port_t outport; |
| 121 | err = __mach_port_mod_refs (__mach_task_self (), |
| 122 | port, |
| 123 | MACH_PORT_RIGHT_SEND, |
| 124 | 1); |
| 125 | if (err) |
| 126 | { |
| 127 | errno = err; |
| 128 | outport = MACH_PORT_NULL; |
| 129 | } |
| 130 | else |
| 131 | outport = port; |
| 132 | outport; |
| 133 | })); |
| 134 | |
| 135 | HURD_CRITICAL_END; |
| 136 | |
| 137 | return dport; |
| 138 | } |
| 139 | |
| 140 | file_t (*_hurd_getdport_fn) (int fd) = get_dtable_port; |
| 141 | |
| 142 | #include <hurd/signal.h> |
| 143 | |
| 144 | /* We are in the child fork; the dtable lock is still held. |
| 145 | The parent has inserted send rights for all the normal io ports, |
| 146 | but we must recover ctty-special ports for ourselves. */ |
| 147 | static error_t |
| 148 | fork_child_dtable (void) |
| 149 | { |
| 150 | error_t err; |
| 151 | int i; |
| 152 | |
| 153 | err = 0; |
| 154 | |
| 155 | for (i = 0; !err && i < _hurd_dtablesize; ++i) |
| 156 | { |
| 157 | struct hurd_fd *d = _hurd_dtable[i]; |
| 158 | if (d == NULL) |
| 159 | continue; |
| 160 | |
| 161 | /* No other thread is using the send rights in the child task. */ |
| 162 | d->port.users = d->ctty.users = NULL; |
| 163 | |
| 164 | if (d->ctty.port != MACH_PORT_NULL) |
| 165 | { |
| 166 | /* There was a ctty-special port in the parent. |
| 167 | We need to get one for ourselves too. */ |
| 168 | __mach_port_deallocate (__mach_task_self (), d->ctty.port); |
| 169 | err = __term_open_ctty (d->port.port, _hurd_pid, _hurd_pgrp, |
| 170 | &d->ctty.port); |
| 171 | if (err) |
| 172 | d->ctty.port = MACH_PORT_NULL; |
| 173 | } |
| 174 | |
| 175 | /* XXX for each fd with a cntlmap, reauth and re-map_cntl. */ |
| 176 | } |
| 177 | return err; |
| 178 | |
| 179 | (void) &fork_child_dtable; /* Avoid "defined but not used" warning. */ |
| 180 | } |
| 181 | |
| 182 | data_set_element (_hurd_fork_locks, _hurd_dtable_lock); /* XXX ld bug: bss */ |
| 183 | text_set_element (_hurd_fork_child_hook, fork_child_dtable); |
| 184 | |
| 185 | /* Called when our process group has changed. */ |
| 186 | |
| 187 | static void |
| 188 | ctty_new_pgrp (void) |
| 189 | { |
| 190 | int i; |
| 191 | |
| 192 | HURD_CRITICAL_BEGIN; |
| 193 | __mutex_lock (&_hurd_dtable_lock); |
| 194 | |
| 195 | if (__USEPORT (CTTYID, port == MACH_PORT_NULL)) |
| 196 | { |
| 197 | /* We have no controlling terminal. If we haven't had one recently, |
| 198 | but our pgrp is being pointlessly diddled anyway, then we will |
| 199 | have nothing to do in the loop below because no fd will have a |
| 200 | ctty port at all. |
| 201 | |
| 202 | More likely, a setsid call is responsible both for the change |
| 203 | in pgrp and for clearing the cttyid port. In that case, setsid |
| 204 | held the dtable lock while updating the dtable to clear all the |
| 205 | ctty ports, and ergo must have finished doing so before we run here. |
| 206 | So we can be sure, again, that the loop below has no work to do. */ |
| 207 | } |
| 208 | else |
| 209 | for (i = 0; i < _hurd_dtablesize; ++i) |
| 210 | { |
| 211 | struct hurd_fd *const d = _hurd_dtable[i]; |
| 212 | struct hurd_userlink ulink, ctty_ulink; |
| 213 | io_t port, ctty; |
| 214 | |
| 215 | if (d == NULL) |
| 216 | /* Nothing to do for an unused descriptor cell. */ |
| 217 | continue; |
| 218 | |
| 219 | port = _hurd_port_get (&d->port, &ulink); |
| 220 | ctty = _hurd_port_get (&d->ctty, &ctty_ulink); |
| 221 | |
| 222 | if (ctty != MACH_PORT_NULL) |
| 223 | { |
| 224 | /* This fd has a ctty-special port. We need a new one, to tell |
| 225 | the io server of our different process group. */ |
| 226 | io_t new; |
| 227 | if (__term_open_ctty (port, _hurd_pid, _hurd_pgrp, &new)) |
| 228 | new = MACH_PORT_NULL; |
| 229 | _hurd_port_set (&d->ctty, new); |
| 230 | } |
| 231 | |
| 232 | _hurd_port_free (&d->port, &ulink, port); |
| 233 | _hurd_port_free (&d->ctty, &ctty_ulink, ctty); |
| 234 | } |
| 235 | |
| 236 | __mutex_unlock (&_hurd_dtable_lock); |
| 237 | HURD_CRITICAL_END; |
| 238 | |
| 239 | (void) &ctty_new_pgrp; /* Avoid "defined but not used" warning. */ |
| 240 | } |
| 241 | |
| 242 | text_set_element (_hurd_pgrp_changed_hook, ctty_new_pgrp); |
| 243 | |
| 244 | /* Called to reauthenticate the dtable when the auth port changes. */ |
| 245 | |
| 246 | static void |
| 247 | reauth_dtable (void) |
| 248 | { |
| 249 | int i; |
| 250 | |
| 251 | HURD_CRITICAL_BEGIN; |
| 252 | __mutex_lock (&_hurd_dtable_lock); |
| 253 | |
| 254 | for (i = 0; i < _hurd_dtablesize; ++i) |
| 255 | { |
| 256 | struct hurd_fd *const d = _hurd_dtable[i]; |
| 257 | mach_port_t new, newctty, ref; |
| 258 | |
| 259 | if (d == NULL) |
| 260 | /* Nothing to do for an unused descriptor cell. */ |
| 261 | continue; |
| 262 | |
| 263 | ref = __mach_reply_port (); |
| 264 | |
| 265 | /* Take the descriptor cell's lock. */ |
| 266 | __spin_lock (&d->port.lock); |
| 267 | |
| 268 | /* Reauthenticate the descriptor's port. */ |
| 269 | if (d->port.port != MACH_PORT_NULL && |
| 270 | ! __io_reauthenticate (d->port.port, |
| 271 | ref, MACH_MSG_TYPE_MAKE_SEND) && |
| 272 | ! __USEPORT (AUTH, __auth_user_authenticate |
| 273 | (port, |
| 274 | ref, MACH_MSG_TYPE_MAKE_SEND, |
| 275 | &new))) |
| 276 | { |
| 277 | /* Replace the port in the descriptor cell |
| 278 | with the newly reauthenticated port. */ |
| 279 | |
| 280 | if (d->ctty.port != MACH_PORT_NULL && |
| 281 | ! __io_reauthenticate (d->ctty.port, |
| 282 | ref, MACH_MSG_TYPE_MAKE_SEND) && |
| 283 | ! __USEPORT (AUTH, __auth_user_authenticate |
| 284 | (port, |
| 285 | ref, MACH_MSG_TYPE_MAKE_SEND, |
| 286 | &newctty))) |
| 287 | _hurd_port_set (&d->ctty, newctty); |
| 288 | |
| 289 | _hurd_port_locked_set (&d->port, new); |
| 290 | } |
| 291 | else |
| 292 | /* Lost. Leave this descriptor cell alone. */ |
| 293 | __spin_unlock (&d->port.lock); |
| 294 | |
| 295 | __mach_port_destroy (__mach_task_self (), ref); |
| 296 | } |
| 297 | |
| 298 | __mutex_unlock (&_hurd_dtable_lock); |
| 299 | HURD_CRITICAL_END; |
| 300 | |
| 301 | (void) &reauth_dtable; /* Avoid "defined but not used" warning. */ |
| 302 | } |
| 303 | |
| 304 | text_set_element (_hurd_reauth_hook, reauth_dtable); |