osfmk/ipc/ipc_object.h

   1 /*
   2  * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  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
  38  * notice and this permission notice appear in all copies of the
  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_object.h
  66  *      Author: Rich Draves
  67  *      Date:   1989
  68  *
  69  *      Definitions for IPC objects, for which tasks have capabilities.
  70  */
  71
  72 #ifndef _IPC_IPC_OBJECT_H_
  73 #define _IPC_IPC_OBJECT_H_
  74
  75 #include <mach_rt.h>
  76
  77 #include <mach/kern_return.h>
  78 #include <mach/message.h>
  79 #include <kern/lock.h>
  80 #include <kern/macro_help.h>
  81 #include <kern/zalloc.h>
  82 #include <ipc/ipc_types.h>
  83 #include <libkern/OSAtomic.h>
  84
  85 typedef natural_t ipc_object_refs_t;    /* for ipc/ipc_object.h         */
  86 typedef natural_t ipc_object_bits_t;
  87 typedef natural_t ipc_object_type_t;
  88
  89 /*
  90  * The ipc_object is used to both tag and reference count these two data
  91  * structures, and (Noto Bene!) pointers to either of these or the
  92  * ipc_object at the head of these are freely cast back and forth; hence
  93  * the ipc_object MUST BE FIRST in the ipc_common_data.
  94  *
  95  * If the RPC implementation enabled user-mode code to use kernel-level
  96  * data structures (as ours used to), this peculiar structuring would
  97  * avoid having anything in user code depend on the kernel configuration
  98  * (with which lock size varies).
  99  */
 100 struct ipc_object {
 101         ipc_object_bits_t io_bits;
 102         ipc_object_refs_t io_references;
 103         lck_spin_t      io_lock_data;
 104 };
 105
 106 /*
 107  * If another object type needs to participate in io_kotype()-based
 108  * dispatching, it must include a stub structure as the first
 109  * element
 110  */
 111 struct ipc_object_header {
 112         ipc_object_bits_t io_bits;
 113 #ifdef __LP64__
 114         natural_t         io_padding; /* pad to natural boundary */
 115 #endif
 116 };
 117
 118 /*
 119  * Legacy defines.  Should use IPC_OBJECT_NULL, etc...
 120  */
 121 #define IO_NULL                 ((ipc_object_t) 0)
 122 #define IO_DEAD                 ((ipc_object_t) ~0UL)
 123 #define IO_VALID(io)            (((io) != IO_NULL) && ((io) != IO_DEAD))
 124
 125 /*
 126  *      IPC steals the high-order bits from the kotype to use
 127  *      for its own purposes.  This allows IPC to record facts
 128  *      about ports that aren't otherwise obvious from the
 129  *      existing port fields.  In particular, IPC can optionally
 130  *      mark a port for no more senders detection.  Any change
 131  *      to IO_BITS_PORT_INFO must be coordinated with bitfield
 132  *      definitions in ipc_port.h.
 133  */
 134 #define IO_BITS_PORT_INFO       0x0000f000      /* stupid port tricks */
 135 #define IO_BITS_KOTYPE          0x00000fff      /* used by the object */
 136 #define IO_BITS_OTYPE           0x7fff0000      /* determines a zone */
 137 #define IO_BITS_ACTIVE          0x80000000      /* is object alive? */
 138
 139 #define io_active(io)           ((io)->io_bits & IO_BITS_ACTIVE)
 140
 141 #define io_otype(io)            (((io)->io_bits & IO_BITS_OTYPE) >> 16)
 142 #define io_kotype(io)           ((io)->io_bits & IO_BITS_KOTYPE)
 143
 144 #define io_makebits(active, otype, kotype)      \
 145         (((active) ? IO_BITS_ACTIVE : 0) | ((otype) << 16) | (kotype))
 146
 147 /*
 148  * Object types: ports, port sets, kernel-loaded ports
 149  */
 150 #define IOT_PORT                0
 151 #define IOT_PORT_SET            1
 152 #define IOT_NUMBER              2               /* number of types used */
 153
 154 extern zone_t ipc_object_zones[IOT_NUMBER];
 155
 156 #define io_alloc(otype)         \
 157                 ((ipc_object_t) zalloc(ipc_object_zones[(otype)]))
 158
 159 extern void     io_free(
 160                         unsigned int    otype,
 161                         ipc_object_t    object);
 162
 163 /*
 164  * Here we depend on the ipc_object being first within the kernel struct
 165  * (ipc_port and ipc_pset).
 166  */
 167 #define io_lock_init(io) \
 168         lck_spin_init(&(io)->io_lock_data, &ipc_lck_grp, &ipc_lck_attr)
 169 #define io_lock_destroy(io) \
 170         lck_spin_destroy(&(io)->io_lock_data, &ipc_lck_grp)
 171 #define io_lock(io) \
 172         lck_spin_lock(&(io)->io_lock_data)
 173 #define io_lock_try(io) \
 174         lck_spin_try_lock(&(io)->io_lock_data)
 175 #define io_unlock(io) \
 176         lck_spin_unlock(&(io)->io_lock_data)
 177
 178 #define _VOLATILE_ volatile
 179
 180 /* Sanity check the ref count.  If it is 0, we may be doubly zfreeing.
 181  * If it is larger than max int, it has been corrupted, probably by being
 182  * modified into an address (this is architecture dependent, but it's
 183  * safe to assume there cannot really be max int references).
 184  *
 185  * NOTE: The 0 test alone will not catch double zfreeing of ipc_port
 186  * structs, because the io_references field is the first word of the struct,
 187  * and zfree modifies that to point to the next free zone element.
 188  */
 189 #define IO_MAX_REFERENCES                                               \
 190         (unsigned)(~0 ^ (1 << (sizeof(int)*BYTE_SIZE - 1)))
 191
 192 static inline void
 193 io_reference(ipc_object_t io) {
 194         assert((io)->io_references > 0 &&
 195             (io)->io_references < IO_MAX_REFERENCES);
 196         OSIncrementAtomic(&((io)->io_references));
 197 }
 198
 199
 200 static inline void
 201 io_release(ipc_object_t io) {
 202         assert((io)->io_references > 0 &&
 203             (io)->io_references < IO_MAX_REFERENCES);
 204         /* If we just removed the last reference count */
 205         if ( 1 == OSDecrementAtomic(&((io)->io_references))) {
 206                 /* Free the object */
 207                 io_free(io_otype((io)), (io));
 208         }
 209 }
 210
 211 /*
 212  * Retrieve a label for use in a kernel call that takes a security
 213  * label as a parameter. If necessary, io_getlabel acquires internal
 214  * (not io_lock) locks, and io_unlocklabel releases them.
 215  */
 216
 217 struct label;
 218 extern struct label *io_getlabel (ipc_object_t obj);
 219 #define io_unlocklabel(obj)
 220
 221 /*
 222  * Exported interfaces
 223  */
 224
 225 /* Take a reference to an object */
 226 extern void ipc_object_reference(
 227         ipc_object_t    object);
 228
 229 /* Release a reference to an object */
 230 extern void ipc_object_release(
 231         ipc_object_t    object);
 232
 233 /* Look up an object in a space */
 234 extern kern_return_t ipc_object_translate(
 235         ipc_space_t             space,
 236         mach_port_name_t        name,
 237         mach_port_right_t       right,
 238         ipc_object_t            *objectp);
 239
 240 /* Look up two objects in a space, locking them in the order described */
 241 extern kern_return_t ipc_object_translate_two(
 242         ipc_space_t             space,
 243         mach_port_name_t        name1,
 244         mach_port_right_t       right1,
 245         ipc_object_t            *objectp1,
 246         mach_port_name_t        name2,
 247         mach_port_right_t       right2,
 248         ipc_object_t            *objectp2);
 249
 250 /* Allocate a dead-name entry */
 251 extern kern_return_t
 252 ipc_object_alloc_dead(
 253         ipc_space_t             space,
 254         mach_port_name_t        *namep);
 255
 256 /*  Allocate a dead-name entry, with a specific name */
 257 extern kern_return_t ipc_object_alloc_dead_name(
 258         ipc_space_t             space,
 259         mach_port_name_t        name);
 260
 261 /* Allocate an object */
 262 extern kern_return_t ipc_object_alloc(
 263         ipc_space_t             space,
 264         ipc_object_type_t       otype,
 265         mach_port_type_t        type,
 266         mach_port_urefs_t       urefs,
 267         mach_port_name_t        *namep,
 268         ipc_object_t            *objectp);
 269
 270 /* Allocate an object, with a specific name */
 271 extern kern_return_t ipc_object_alloc_name(
 272         ipc_space_t             space,
 273         ipc_object_type_t       otype,
 274         mach_port_type_t        type,
 275         mach_port_urefs_t       urefs,
 276         mach_port_name_t        name,
 277         ipc_object_t            *objectp);
 278
 279 /* Convert a send type name to a received type name */
 280 extern mach_msg_type_name_t ipc_object_copyin_type(
 281         mach_msg_type_name_t    msgt_name);
 282
 283 /* Copyin a capability from a space */
 284 extern kern_return_t ipc_object_copyin(
 285         ipc_space_t             space,
 286         mach_port_name_t        name,
 287         mach_msg_type_name_t    msgt_name,
 288         ipc_object_t            *objectp);
 289
 290 /* Copyin a naked capability from the kernel */
 291 extern void ipc_object_copyin_from_kernel(
 292         ipc_object_t            object,
 293         mach_msg_type_name_t    msgt_name);
 294
 295 /* Destroy a naked capability */
 296 extern void ipc_object_destroy(
 297         ipc_object_t            object,
 298         mach_msg_type_name_t    msgt_name);
 299
 300 /* Destroy a naked destination capability */
 301 extern void ipc_object_destroy_dest(
 302         ipc_object_t            object,
 303         mach_msg_type_name_t    msgt_name);
 304
 305 /* Copyout a capability, placing it into a space */
 306 extern kern_return_t ipc_object_copyout(
 307         ipc_space_t             space,
 308         ipc_object_t            object,
 309         mach_msg_type_name_t    msgt_name,
 310         boolean_t               overflow,
 311         mach_port_name_t        *namep);
 312
 313 /* Copyout a capability with a name, placing it into a space */
 314 extern kern_return_t ipc_object_copyout_name(
 315         ipc_space_t             space,
 316         ipc_object_t            object,
 317         mach_msg_type_name_t    msgt_name,
 318         boolean_t               overflow,
 319         mach_port_name_t        name);
 320
 321 /* Translate/consume the destination right of a message */
 322 extern void ipc_object_copyout_dest(
 323         ipc_space_t             space,
 324         ipc_object_t            object,
 325         mach_msg_type_name_t    msgt_name,
 326         mach_port_name_t        *namep);
 327
 328 /* Rename an entry in a space */
 329 extern kern_return_t ipc_object_rename(
 330         ipc_space_t             space,
 331         mach_port_name_t        oname,
 332         mach_port_name_t        nname);
 333
 334 #endif  /* _IPC_IPC_OBJECT_H_ */