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
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  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.
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  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
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  53  * any improvements or extensions that they make and grant Carnegie Mellon
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  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/boolean.h>
  73 #include <mach/kern_return.h>
  74 #include <mach/port.h>
  75 #include <kern/assert.h>
  76 #include <kern/sched_prim.h>
  77 #include <kern/zalloc.h>
  78 #include <ipc/port.h>
  79 #include <ipc/ipc_entry.h>
  80 #include <ipc/ipc_object.h>
  81 #include <ipc/ipc_hash.h>
  82 #include <ipc/ipc_table.h>
  83 #include <ipc/ipc_port.h>
  84 #include <ipc/ipc_space.h>
  85 #include <ipc/ipc_right.h>
  86 #include <string.h>
  87
  88 zone_t ipc_space_zone;
  89 ipc_space_t ipc_space_kernel;
  90 ipc_space_t ipc_space_reply;
  91
  92 /*
  93  *      Routine:        ipc_space_reference
  94  *      Routine:        ipc_space_release
  95  *      Purpose:
  96  *              Function versions of the IPC space inline reference.
  97  */
  98
  99 void
 100 ipc_space_reference(
 101         ipc_space_t     space)
 102 {
 103         is_reference(space);
 104 }
 105
 106 void
 107 ipc_space_release(
 108         ipc_space_t     space)
 109 {
 110         is_release(space);
 111 }
 112
 113 /*
 114  *      Routine:        ipc_space_create
 115  *      Purpose:
 116  *              Creates a new IPC space.
 117  *
 118  *              The new space has two references, one for the caller
 119  *              and one because it is active.
 120  *      Conditions:
 121  *              Nothing locked.  Allocates memory.
 122  *      Returns:
 123  *              KERN_SUCCESS            Created a space.
 124  *              KERN_RESOURCE_SHORTAGE  Couldn't allocate memory.
 125  */
 126
 127 kern_return_t
 128 ipc_space_create(
 129         ipc_table_size_t        initial,
 130         ipc_space_t             *spacep)
 131 {
 132         ipc_space_t space;
 133         ipc_entry_t table;
 134         ipc_entry_num_t new_size;
 135         mach_port_index_t index;
 136
 137         space = is_alloc();
 138         if (space == IS_NULL)
 139                 return KERN_RESOURCE_SHORTAGE;
 140
 141         table = it_entries_alloc(initial);
 142         if (table == IE_NULL) {
 143                 is_free(space);
 144                 return KERN_RESOURCE_SHORTAGE;
 145         }
 146
 147         new_size = initial->its_size;
 148         memset((void *) table, 0, new_size * sizeof(struct ipc_entry));
 149
 150         /*
 151          *      Initialize the free list in the table.
 152          *      Add the entries in reverse order, and
 153          *      set the generation number to -1, so that
 154          *      initial allocations produce "natural" names.
 155          */
 156         for (index = 0; index < new_size; index++) {
 157                 ipc_entry_t entry = &table[index];
 158
 159                 entry->ie_bits = IE_BITS_GEN_MASK;
 160                 entry->ie_next = index+1;
 161         }
 162         table[new_size-1].ie_next = 0;
 163
 164         is_lock_init(space);
 165         space->is_bits = 2; /* 2 refs, active, not growing */
 166         space->is_table_size = new_size;
 167         space->is_table_free = new_size - 1;
 168         space->is_table = table;
 169         space->is_table_next = initial+1;
 170         space->is_task = NULL;
 171         space->is_low_mod = new_size;
 172         space->is_high_mod = 0;
 173
 174         *spacep = space;
 175         return KERN_SUCCESS;
 176 }
 177
 178 /*
 179  *      Routine:        ipc_space_create_special
 180  *      Purpose:
 181  *              Create a special space.  A special space
 182  *              doesn't hold rights in the normal way.
 183  *              Instead it is place-holder for holding
 184  *              disembodied (naked) receive rights.
 185  *              See ipc_port_alloc_special/ipc_port_dealloc_special.
 186  *      Conditions:
 187  *              Nothing locked.
 188  *      Returns:
 189  *              KERN_SUCCESS            Created a space.
 190  *              KERN_RESOURCE_SHORTAGE  Couldn't allocate memory.
 191  */
 192
 193 kern_return_t
 194 ipc_space_create_special(
 195         ipc_space_t     *spacep)
 196 {
 197         ipc_space_t space;
 198
 199         space = is_alloc();
 200         if (space == IS_NULL)
 201                 return KERN_RESOURCE_SHORTAGE;
 202
 203         is_lock_init(space);
 204
 205         space->is_bits       = IS_INACTIVE | 1; /* 1 ref, not active, not growing */
 206         space->is_table      = IE_NULL;
 207         space->is_task       = TASK_NULL;
 208         space->is_table_next = 0;
 209         space->is_low_mod    = 0;
 210         space->is_high_mod   = 0;
 211
 212         *spacep = space;
 213         return KERN_SUCCESS;
 214 }
 215
 216 /*
 217  * ipc_space_clean - remove all port references from an ipc space.
 218  *
 219  * In order to follow the traditional semantic, ipc_space_destroy
 220  * will not destroy the entire port table of a shared space.  Instead
 221  * it will simply clear its own sub-space.
 222  */
 223 void
 224 ipc_space_clean(
 225         ipc_space_t space)
 226 {
 227         ipc_entry_t table;
 228         ipc_entry_num_t size;
 229         mach_port_index_t index;
 230
 231         /*
 232          *      If somebody is trying to grow the table,
 233          *      we must wait until they finish and figure
 234          *      out the space died.
 235          */
 236  retry:
 237         is_write_lock(space);
 238         while (is_growing(space))
 239                 is_write_sleep(space);
 240
 241         if (!is_active(space)) {
 242                 is_write_unlock(space);
 243                 return;
 244         }
 245
 246         /*
 247          *      Now we can futz with it since we have the write lock.
 248          */
 249
 250         table = space->is_table;
 251         size = space->is_table_size;
 252
 253         for (index = 0; index < size; index++) {
 254                 ipc_entry_t entry = &table[index];
 255                 mach_port_type_t type;
 256
 257                 type = IE_BITS_TYPE(entry->ie_bits);
 258                 if (type != MACH_PORT_TYPE_NONE) {
 259                         mach_port_name_t name = MACH_PORT_MAKE(index,
 260                                                 IE_BITS_GEN(entry->ie_bits));
 261                         ipc_right_destroy(space, name, entry, FALSE, 0); /* unlocks space */
 262                         goto retry;
 263                 }
 264         }
 265
 266         /*
 267          * JMM - Now the table is cleaned out.  We don't bother shrinking the
 268          * size of the table at this point, but we probably should if it is
 269          * really large.
 270          */
 271
 272         is_write_unlock(space);
 273 }
 274
 275
 276 /*
 277  *      Routine:        ipc_space_terminate
 278  *      Purpose:
 279  *              Marks the space as dead and cleans up the entries.
 280  *              Does nothing if the space is already dead.
 281  *      Conditions:
 282  *              Nothing locked.
 283  */
 284
 285 void
 286 ipc_space_terminate(
 287         ipc_space_t     space)
 288 {
 289         ipc_entry_t table;
 290         ipc_entry_num_t size;
 291         mach_port_index_t index;
 292
 293         assert(space != IS_NULL);
 294
 295         is_write_lock(space);
 296         if (!is_active(space)) {
 297                 is_write_unlock(space);
 298                 return;
 299         }
 300         is_mark_inactive(space);
 301
 302         /*
 303          *      If somebody is trying to grow the table,
 304          *      we must wait until they finish and figure
 305          *      out the space died.
 306          */
 307         while (is_growing(space))
 308                 is_write_sleep(space);
 309
 310         is_write_unlock(space);
 311
 312
 313         /*
 314          *      Now we can futz with it unlocked.
 315          */
 316
 317         table = space->is_table;
 318         size = space->is_table_size;
 319
 320         for (index = 0; index < size; index++) {
 321                 ipc_entry_t entry = &table[index];
 322                 mach_port_type_t type;
 323
 324                 type = IE_BITS_TYPE(entry->ie_bits);
 325                 if (type != MACH_PORT_TYPE_NONE) {
 326                         mach_port_name_t name;
 327
 328                         name = MACH_PORT_MAKE(index,
 329                                               IE_BITS_GEN(entry->ie_bits));
 330                         ipc_right_terminate(space, name, entry);
 331                 }
 332         }
 333
 334         it_entries_free(space->is_table_next-1, table);
 335         space->is_table_size = 0;
 336         space->is_table_free = 0;
 337
 338         /*
 339          *      Because the space is now dead,
 340          *      we must release the "active" reference for it.
 341          *      Our caller still has his reference.
 342          */
 343         is_release(space);
 344 }
 345
 346