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 #include <mach_kdb.h>
  77
  78 #include <mach/kern_return.h>
  79 #include <mach/message.h>
  80 #include <kern/lock.h>
  81 #include <kern/macro_help.h>
  82 #include <kern/zalloc.h>
  83 #include <ipc/ipc_types.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  * There is no lock in the ipc_object; it is in the enclosing kernel
  91  * data structure (rpc_common_data) used by both ipc_port and ipc_pset.
  92  * The ipc_object is used to both tag and reference count these two data
  93  * structures, and (Noto Bene!) pointers to either of these or the
  94  * ipc_object at the head of these are freely cast back and forth; hence
  95  * the ipc_object MUST BE FIRST in the ipc_common_data.
  96  *
  97  * If the RPC implementation enabled user-mode code to use kernel-level
  98  * data structures (as ours used to), this peculiar structuring would
  99  * avoid having anything in user code depend on the kernel configuration
 100  * (with which lock size varies).
 101  */
 102 struct ipc_object {
 103         ipc_object_refs_t io_references;
 104         ipc_object_bits_t io_bits;
 105         mach_port_name_t  io_receiver_name;
 106         decl_mutex_data(,       io_lock_data)
 107 };
 108
 109 /*
 110  * Legacy defines.  Should use IPC_OBJECT_NULL, etc...
 111  */
 112 #define IO_NULL                 ((ipc_object_t) 0)
 113 #define IO_DEAD                 ((ipc_object_t) -1)
 114 #define IO_VALID(io)            (((io) != IO_NULL) && ((io) != IO_DEAD))
 115
 116 /*
 117  *      IPC steals the high-order bits from the kotype to use
 118  *      for its own purposes.  This allows IPC to record facts
 119  *      about ports that aren't otherwise obvious from the
 120  *      existing port fields.  In particular, IPC can optionally
 121  *      mark a port for no more senders detection.  Any change
 122  *      to IO_BITS_PORT_INFO must be coordinated with bitfield
 123  *      definitions in ipc_port.h.
 124  */
 125 #define IO_BITS_PORT_INFO       0x0000f000      /* stupid port tricks */
 126 #define IO_BITS_KOTYPE          0x00000fff      /* used by the object */
 127 #define IO_BITS_OTYPE           0x7fff0000      /* determines a zone */
 128 #define IO_BITS_ACTIVE          0x80000000      /* is object alive? */
 129
 130 #define io_active(io)           ((io)->io_bits & IO_BITS_ACTIVE)
 131
 132 #define io_otype(io)            (((io)->io_bits & IO_BITS_OTYPE) >> 16)
 133 #define io_kotype(io)           ((io)->io_bits & IO_BITS_KOTYPE)
 134
 135 #define io_makebits(active, otype, kotype)      \
 136         (((active) ? IO_BITS_ACTIVE : 0) | ((otype) << 16) | (kotype))
 137
 138 /*
 139  * Object types: ports, port sets, kernel-loaded ports
 140  */
 141 #define IOT_PORT                0
 142 #define IOT_PORT_SET            1
 143 #define IOT_NUMBER              2               /* number of types used */
 144
 145 extern zone_t ipc_object_zones[IOT_NUMBER];
 146
 147 #define io_alloc(otype)         \
 148                 ((ipc_object_t) zalloc(ipc_object_zones[(otype)]))
 149
 150 #if MACH_ASSERT || CONFIG_MACF_MACH
 151 /*
 152  *      Call the routine for io_free so that checking can be performed.
 153  */
 154 extern void     io_free(
 155                         unsigned int    otype,
 156                         ipc_object_t    object);
 157
 158 #else   /* MACH_ASSERT || MAC_MACH */
 159 #define io_free(otype, io)  \
 160         zfree(ipc_object_zones[(otype)], (io))
 161 #endif  /* MACH_ASSERT || MAC_MACH */
 162
 163 /*
 164  * Here we depend on the ipc_object being first within the ipc_common_data,
 165  * which is first within the rpc_common_data, which in turn must be first
 166  * within any kernel data structure needing to lock an ipc_object
 167  * (ipc_port and ipc_pset).
 168  */
 169 #define io_lock_init(io) \
 170         mutex_init(&(io)->io_lock_data, 0)
 171 #define io_lock(io) \
 172         mutex_lock(&(io)->io_lock_data)
 173 #define io_lock_try(io) \
 174         mutex_try(&(io)->io_lock_data)
 175 #define io_unlock(io) \
 176         mutex_unlock(&(io)->io_lock_data)
 177
 178 #define _VOLATILE_ volatile
 179
 180 #define io_check_unlock(io)                                             \
 181 MACRO_BEGIN                                                             \
 182         _VOLATILE_ ipc_object_refs_t _refs = (io)->io_references;       \
 183                                                                         \
 184         io_unlock(io);                                                  \
 185         if (_refs == 0)                                                 \
 186                 io_free(io_otype(io), io);                              \
 187 MACRO_END
 188
 189 /* Sanity check the ref count.  If it is 0, we may be doubly zfreeing.
 190  * If it is larger than max int, it has been corrupted, probably by being
 191  * modified into an address (this is architecture dependent, but it's
 192  * safe to assume there cannot really be max int references).
 193  *
 194  * NOTE: The 0 test alone will not catch double zfreeing of ipc_port
 195  * structs, because the io_references field is the first word of the struct,
 196  * and zfree modifies that to point to the next free zone element.
 197  */
 198 #define IO_MAX_REFERENCES                                               \
 199         (unsigned)(~0 ^ (1 << (sizeof(int)*BYTE_SIZE - 1)))
 200
 201 #define io_reference(io)                                                \
 202 MACRO_BEGIN                                                             \
 203         assert((io)->io_references < IO_MAX_REFERENCES);                \
 204         (io)->io_references++;                                          \
 205 MACRO_END
 206
 207 #define io_release(io)                                                  \
 208 MACRO_BEGIN                                                             \
 209         assert((io)->io_references > 0 &&                               \
 210                     (io)->io_references <= IO_MAX_REFERENCES);          \
 211         (io)->io_references--;                                          \
 212 MACRO_END
 213
 214 /*
 215  * Retrieve a label for use in a kernel call that takes a security
 216  * label as a parameter. If necessary, io_getlabel acquires internal
 217  * (not io_lock) locks, and io_unlocklabel releases them.
 218  */
 219
 220 struct label;
 221 extern struct label *io_getlabel (ipc_object_t obj);
 222 #define io_unlocklabel(obj)
 223
 224 /*
 225  * Exported interfaces
 226  */
 227
 228 /* Take a reference to an object */
 229 extern void ipc_object_reference(
 230         ipc_object_t    object);
 231
 232 /* Release a reference to an object */
 233 extern void ipc_object_release(
 234         ipc_object_t    object);
 235
 236 /* Look up an object in a space */
 237 extern kern_return_t ipc_object_translate(
 238         ipc_space_t             space,
 239         mach_port_name_t        name,
 240         mach_port_right_t       right,
 241         ipc_object_t            *objectp);
 242
 243 /* Look up two objects in a space, locking them in the order described */
 244 extern kern_return_t ipc_object_translate_two(
 245         ipc_space_t             space,
 246         mach_port_name_t        name1,
 247         mach_port_right_t       right1,
 248         ipc_object_t            *objectp1,
 249         mach_port_name_t        name2,
 250         mach_port_right_t       right2,
 251         ipc_object_t            *objectp2);
 252
 253 /* Allocate a dead-name entry */
 254 extern kern_return_t
 255 ipc_object_alloc_dead(
 256         ipc_space_t             space,
 257         mach_port_name_t        *namep);
 258
 259 /*  Allocate a dead-name entry, with a specific name */
 260 extern kern_return_t ipc_object_alloc_dead_name(
 261         ipc_space_t             space,
 262         mach_port_name_t        name);
 263
 264 /* Allocate an object */
 265 extern kern_return_t ipc_object_alloc(
 266         ipc_space_t             space,
 267         ipc_object_type_t       otype,
 268         mach_port_type_t        type,
 269         mach_port_urefs_t       urefs,
 270         mach_port_name_t        *namep,
 271         ipc_object_t            *objectp);
 272
 273 /* Allocate an object, with a specific name */
 274 extern kern_return_t ipc_object_alloc_name(
 275         ipc_space_t             space,
 276         ipc_object_type_t       otype,
 277         mach_port_type_t        type,
 278         mach_port_urefs_t       urefs,
 279         mach_port_name_t        name,
 280         ipc_object_t            *objectp);
 281
 282 /* Convert a send type name to a received type name */
 283 extern mach_msg_type_name_t ipc_object_copyin_type(
 284         mach_msg_type_name_t    msgt_name);
 285
 286 /* Copyin a capability from a space */
 287 extern kern_return_t ipc_object_copyin(
 288         ipc_space_t             space,
 289         mach_port_name_t        name,
 290         mach_msg_type_name_t    msgt_name,
 291         ipc_object_t            *objectp);
 292
 293 /* Copyin a naked capability from the kernel */
 294 extern void ipc_object_copyin_from_kernel(
 295         ipc_object_t            object,
 296         mach_msg_type_name_t    msgt_name);
 297
 298 /* Destroy a naked capability */
 299 extern void ipc_object_destroy(
 300         ipc_object_t            object,
 301         mach_msg_type_name_t    msgt_name);
 302
 303 /* Copyout a capability, placing it into a space */
 304 extern kern_return_t ipc_object_copyout(
 305         ipc_space_t             space,
 306         ipc_object_t            object,
 307         mach_msg_type_name_t    msgt_name,
 308         boolean_t               overflow,
 309         mach_port_name_t        *namep);
 310
 311 /* Copyout a capability with a name, placing it into a space */
 312 extern kern_return_t ipc_object_copyout_name(
 313         ipc_space_t             space,
 314         ipc_object_t            object,
 315         mach_msg_type_name_t    msgt_name,
 316         boolean_t               overflow,
 317         mach_port_name_t        name);
 318
 319 /* Translate/consume the destination right of a message */
 320 extern void ipc_object_copyout_dest(
 321         ipc_space_t             space,
 322         ipc_object_t            object,
 323         mach_msg_type_name_t    msgt_name,
 324         mach_port_name_t        *namep);
 325
 326 /* Rename an entry in a space */
 327 extern kern_return_t ipc_object_rename(
 328         ipc_space_t             space,
 329         mach_port_name_t        oname,
 330         mach_port_name_t        nname);
 331
 332 #if     MACH_KDB
 333 /* Pretty-print an ipc object */
 334
 335 extern void ipc_object_print(
 336         ipc_object_t    object);
 337
 338 #endif  /* MACH_KDB */
 339
 340 #endif  /* _IPC_IPC_OBJECT_H_ */