osfmk/ipc/ipc_space.c

   1 /*
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  28 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  34  * All Rights Reserved.
  35  *
  36  * Permission to use, copy, modify and distribute this software and its
  37  * documentation is hereby granted, provided that both the copyright
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  39  * software, derivative works or modified versions, and any portions
  40  * thereof, and that both notices appear in supporting documentation.
  41  *
  42  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  43  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  44  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  45  *
  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  49  *  School of Computer Science
  50  *  Carnegie Mellon University
  51  *  Pittsburgh PA 15213-3890
  52  *
  53  * any improvements or extensions that they make and grant Carnegie Mellon
  54  * the rights to redistribute these changes.
  55  */
  56 /*
  57  * NOTICE: This file was modified by McAfee Research in 2004 to introduce
  58  * support for mandatory and extensible security protections.  This notice
  59  * is included in support of clause 2.2 (b) of the Apple Public License,
  60  * Version 2.0.
  61  */
  62 /*
  63  */
  64 /*
  65  *      File:   ipc/ipc_space.c
  66  *      Author: Rich Draves
  67  *      Date:   1989
  68  *
  69  *      Functions to manipulate IPC capability spaces.
  70  */
  71
  72 #include <mach_kdb.h>
  73
  74 #include <mach/boolean.h>
  75 #include <mach/kern_return.h>
  76 #include <mach/port.h>
  77 #include <kern/assert.h>
  78 #include <kern/sched_prim.h>
  79 #include <kern/zalloc.h>
  80 #include <ipc/port.h>
  81 #include <ipc/ipc_entry.h>
  82 #include <ipc/ipc_splay.h>
  83 #include <ipc/ipc_object.h>
  84 #include <ipc/ipc_hash.h>
  85 #include <ipc/ipc_table.h>
  86 #include <ipc/ipc_port.h>
  87 #include <ipc/ipc_space.h>
  88 #include <ipc/ipc_right.h>
  89 #include <string.h>
  90
  91 zone_t ipc_space_zone;
  92 ipc_space_t ipc_space_kernel;
  93 ipc_space_t ipc_space_reply;
  94 #if     MACH_KDB
  95 ipc_space_t default_pager_space;
  96 #endif  /* MACH_KDB */
  97
  98 /*
  99  *      Routine:        ipc_space_reference
 100  *      Routine:        ipc_space_release
 101  *      Purpose:
 102  *              Function versions of the IPC space macros.
 103  *              The "is_" cover macros can be defined to use the
 104  *              macros or the functions, as desired.
 105  */
 106
 107 void
 108 ipc_space_reference(
 109         ipc_space_t     space)
 110 {
 111         ipc_space_reference_macro(space);
 112 }
 113
 114 void
 115 ipc_space_release(
 116         ipc_space_t     space)
 117 {
 118         ipc_space_release_macro(space);
 119 }
 120
 121 /*
 122  *      Routine:        ipc_space_create
 123  *      Purpose:
 124  *              Creates a new IPC space.
 125  *
 126  *              The new space has two references, one for the caller
 127  *              and one because it is active.
 128  *      Conditions:
 129  *              Nothing locked.  Allocates memory.
 130  *      Returns:
 131  *              KERN_SUCCESS            Created a space.
 132  *              KERN_RESOURCE_SHORTAGE  Couldn't allocate memory.
 133  */
 134
 135 kern_return_t
 136 ipc_space_create(
 137         ipc_table_size_t        initial,
 138         ipc_space_t             *spacep)
 139 {
 140         ipc_space_t space;
 141         ipc_entry_t table;
 142         ipc_entry_num_t new_size;
 143         mach_port_index_t index;
 144
 145         space = is_alloc();
 146         if (space == IS_NULL)
 147                 return KERN_RESOURCE_SHORTAGE;
 148
 149         table = it_entries_alloc(initial);
 150         if (table == IE_NULL) {
 151                 is_free(space);
 152                 return KERN_RESOURCE_SHORTAGE;
 153         }
 154
 155         new_size = initial->its_size;
 156         memset((void *) table, 0, new_size * sizeof(struct ipc_entry));
 157
 158         /*
 159          *      Initialize the free list in the table.
 160          *      Add the entries in reverse order, and
 161          *      set the generation number to -1, so that
 162          *      initial allocations produce "natural" names.
 163          */
 164         for (index = 0; index < new_size; index++) {
 165                 ipc_entry_t entry = &table[index];
 166
 167                 entry->ie_bits = IE_BITS_GEN_MASK;
 168                 entry->ie_next = index+1;
 169         }
 170         table[new_size-1].ie_next = 0;
 171
 172         is_ref_lock_init(space);
 173         space->is_references = 2;
 174
 175         is_lock_init(space);
 176         space->is_active = TRUE;
 177         space->is_growing = FALSE;
 178         space->is_table = table;
 179         space->is_table_size = new_size;
 180         space->is_table_next = initial+1;
 181
 182         ipc_splay_tree_init(&space->is_tree);
 183         space->is_tree_total = 0;
 184         space->is_tree_small = 0;
 185         space->is_tree_hash = 0;
 186         space->is_task = NULL;
 187
 188         *spacep = space;
 189         return KERN_SUCCESS;
 190 }
 191
 192 /*
 193  *      Routine:        ipc_space_create_special
 194  *      Purpose:
 195  *              Create a special space.  A special space
 196  *              doesn't hold rights in the normal way.
 197  *              Instead it is place-holder for holding
 198  *              disembodied (naked) receive rights.
 199  *              See ipc_port_alloc_special/ipc_port_dealloc_special.
 200  *      Conditions:
 201  *              Nothing locked.
 202  *      Returns:
 203  *              KERN_SUCCESS            Created a space.
 204  *              KERN_RESOURCE_SHORTAGE  Couldn't allocate memory.
 205  */
 206
 207 kern_return_t
 208 ipc_space_create_special(
 209         ipc_space_t     *spacep)
 210 {
 211         ipc_space_t space;
 212
 213         space = is_alloc();
 214         if (space == IS_NULL)
 215                 return KERN_RESOURCE_SHORTAGE;
 216
 217         is_ref_lock_init(space);
 218         space->is_references = 1;
 219
 220         is_lock_init(space);
 221         space->is_active = FALSE;
 222
 223         *spacep = space;
 224         return KERN_SUCCESS;
 225 }
 226
 227 /*
 228  * ipc_space_clean - remove all port references from an ipc space.
 229  *
 230  * In order to follow the traditional semantic, ipc_space_destroy
 231  * will not destroy the entire port table of a shared space.  Instead
 232  * it will simply clear its own sub-space.
 233  */
 234 void
 235 ipc_space_clean(
 236         ipc_space_t space)
 237 {
 238         ipc_tree_entry_t tentry;
 239         ipc_entry_t table;
 240         ipc_entry_num_t size;
 241         mach_port_index_t index;
 242
 243         /*
 244          *      If somebody is trying to grow the table,
 245          *      we must wait until they finish and figure
 246          *      out the space died.
 247          */
 248         is_write_lock(space);
 249         while (space->is_growing)
 250                 is_write_sleep(space);
 251
 252         /*
 253          *      Now we can futz with it since we have the write lock.
 254          */
 255 #if     MACH_KDB
 256         if (space == default_pager_space)
 257                 default_pager_space = IS_NULL;
 258 #endif  /* MACH_KDB */
 259
 260         table = space->is_table;
 261         size = space->is_table_size;
 262
 263         for (index = 0; index < size; index++) {
 264                 ipc_entry_t entry = &table[index];
 265                 mach_port_type_t type;
 266
 267                 type = IE_BITS_TYPE(entry->ie_bits);
 268                 if (type != MACH_PORT_TYPE_NONE) {
 269                         mach_port_name_t name = MACH_PORT_MAKE(index,
 270                                                 IE_BITS_GEN(entry->ie_bits));
 271                         ipc_right_destroy(space, name, entry);
 272                 }
 273         }
 274
 275         /*
 276          * JMM - Now the table is cleaned out.  We don't bother shrinking the
 277          * size of the table at this point, but we probably should if it is
 278          * really large.  Lets just clean up the splay tree.
 279          */
 280  start_splay:
 281         for (tentry = ipc_splay_traverse_start(&space->is_tree);
 282              tentry != ITE_NULL;
 283              tentry = ipc_splay_traverse_next(&space->is_tree, TRUE)) {
 284                 mach_port_type_t type;
 285                 mach_port_name_t name = tentry->ite_name;
 286
 287                 type = IE_BITS_TYPE(tentry->ite_bits);
 288                 /*
 289                  * If it is a real right, then destroy it.  This will have the
 290                  * side effect of removing it from the splay, so start over.
 291                  */
 292                 if(type != MACH_PORT_TYPE_NONE) {
 293                         ipc_splay_traverse_finish(&space->is_tree);
 294                         ipc_right_destroy(space, name, &tentry->ite_entry);
 295                         goto start_splay;
 296                 }
 297         }
 298         ipc_splay_traverse_finish(&space->is_tree);
 299         is_write_unlock(space);
 300 }
 301
 302
 303 /*
 304  *      Routine:        ipc_space_destroy
 305  *      Purpose:
 306  *              Marks the space as dead and cleans up the entries.
 307  *              Does nothing if the space is already dead.
 308  *      Conditions:
 309  *              Nothing locked.
 310  */
 311
 312 void
 313 ipc_space_destroy(
 314         ipc_space_t     space)
 315 {
 316         boolean_t active;
 317         ipc_tree_entry_t tentry;
 318         ipc_entry_t table;
 319         ipc_entry_num_t size;
 320         mach_port_index_t index;
 321
 322         assert(space != IS_NULL);
 323
 324         is_write_lock(space);
 325         active = space->is_active;
 326         space->is_active = FALSE;
 327         is_write_unlock(space);
 328
 329         if (!active)
 330                 return;
 331
 332
 333         /*
 334          *      If somebody is trying to grow the table,
 335          *      we must wait until they finish and figure
 336          *      out the space died.
 337          */
 338         is_read_lock(space);
 339         while (space->is_growing)
 340                 is_read_sleep(space);
 341
 342         is_read_unlock(space);
 343         /*
 344          *      Now we can futz with it unlocked.
 345          */
 346 #if     MACH_KDB
 347         if (space == default_pager_space)
 348                 default_pager_space = IS_NULL;
 349 #endif  /* MACH_KDB */
 350
 351         table = space->is_table;
 352         size = space->is_table_size;
 353
 354         for (index = 0; index < size; index++) {
 355                 ipc_entry_t entry = &table[index];
 356                 mach_port_type_t type;
 357
 358                 type = IE_BITS_TYPE(entry->ie_bits);
 359                 if (type != MACH_PORT_TYPE_NONE) {
 360                         mach_port_name_t name;
 361
 362                         name = MACH_PORT_MAKE(index,
 363                                               IE_BITS_GEN(entry->ie_bits));
 364                         ipc_right_clean(space, name, entry);
 365                 }
 366         }
 367
 368         it_entries_free(space->is_table_next-1, table);
 369         space->is_table_size = 0;
 370
 371         for (tentry = ipc_splay_traverse_start(&space->is_tree);
 372              tentry != ITE_NULL;
 373              tentry = ipc_splay_traverse_next(&space->is_tree, TRUE)) {
 374                 mach_port_type_t type;
 375                 mach_port_name_t name = tentry->ite_name;
 376
 377                 type = IE_BITS_TYPE(tentry->ite_bits);
 378                 assert(type != MACH_PORT_TYPE_NONE);
 379
 380                 ipc_right_clean(space, name, &tentry->ite_entry);
 381
 382                 if(type == MACH_PORT_TYPE_SEND)
 383                         ipc_hash_global_delete(space, tentry->ite_object,
 384                                                name, tentry);
 385         }
 386         ipc_splay_traverse_finish(&space->is_tree);
 387
 388         /*
 389          *      Because the space is now dead,
 390          *      we must release the "active" reference for it.
 391          *      Our caller still has his reference.
 392          */
 393         is_release(space);
 394 }
 395
 396