osfmk/ipc/ipc_object.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
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  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_COPYRIGHT@
  24  */
  25 /*
  26  * Mach Operating System
  27  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  28  * All Rights Reserved.
  29  *
  30  * Permission to use, copy, modify and distribute this software and its
  31  * documentation is hereby granted, provided that both the copyright
  32  * notice and this permission notice appear in all copies of the
  33  * software, derivative works or modified versions, and any portions
  34  * thereof, and that both notices appear in supporting documentation.
  35  *
  36  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  37  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  38  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  39  *
  40  * Carnegie Mellon requests users of this software to return to
  41  *
  42  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  43  *  School of Computer Science
  44  *  Carnegie Mellon University
  45  *  Pittsburgh PA 15213-3890
  46  *
  47  * any improvements or extensions that they make and grant Carnegie Mellon
  48  * the rights to redistribute these changes.
  49  */
  50 /*
  51  */
  52 /*
  53  *      File:   ipc/ipc_object.h
  54  *      Author: Rich Draves
  55  *      Date:   1989
  56  *
  57  *      Definitions for IPC objects, for which tasks have capabilities.
  58  */
  59
  60 #ifndef _IPC_IPC_OBJECT_H_
  61 #define _IPC_IPC_OBJECT_H_
  62
  63 #include <mach_rt.h>
  64 #include <cpus.h>
  65 #include <mach_kdb.h>
  66
  67 #include <mach/kern_return.h>
  68 #include <mach/message.h>
  69 #include <kern/lock.h>
  70 #include <kern/macro_help.h>
  71 #include <kern/zalloc.h>
  72 #include <ipc/ipc_types.h>
  73
  74 typedef natural_t ipc_object_refs_t;    /* for ipc/ipc_object.h         */
  75 typedef natural_t ipc_object_bits_t;
  76 typedef natural_t ipc_object_type_t;
  77
  78 /*
  79  * There is no lock in the ipc_object; it is in the enclosing kernel
  80  * data structure (rpc_common_data) used by both ipc_port and ipc_pset.
  81  * The ipc_object is used to both tag and reference count these two data
  82  * structures, and (Noto Bene!) pointers to either of these or the
  83  * ipc_object at the head of these are freely cast back and forth; hence
  84  * the ipc_object MUST BE FIRST in the ipc_common_data.
  85  *
  86  * If the RPC implementation enabled user-mode code to use kernel-level
  87  * data structures (as ours used to), this peculiar structuring would
  88  * avoid having anything in user code depend on the kernel configuration
  89  * (with which lock size varies).
  90  */
  91 struct ipc_object {
  92         ipc_object_refs_t io_references;
  93         ipc_object_bits_t io_bits;
  94         port_name_t       io_receiver_name;
  95 #if NCPUS == 1
  96         usimple_lock_data_t     io_lock_data;
  97 #else
  98         decl_mutex_data(,       io_lock_data)
  99 #endif
 100 };
 101
 102 /*
 103  * Legacy defines.  Should use IPC_OBJECT_NULL, etc...
 104  */
 105 #define IO_NULL                 ((ipc_object_t) 0)
 106 #define IO_DEAD                 ((ipc_object_t) -1)
 107 #define IO_VALID(io)            (((io) != IO_NULL) && ((io) != IO_DEAD))
 108
 109 /*
 110  *      IPC steals the high-order bits from the kotype to use
 111  *      for its own purposes.  This allows IPC to record facts
 112  *      about ports that aren't otherwise obvious from the
 113  *      existing port fields.  In particular, IPC can optionally
 114  *      mark a port for no more senders detection.  Any change
 115  *      to IO_BITS_PORT_INFO must be coordinated with bitfield
 116  *      definitions in ipc_port.h.
 117  */
 118 #define IO_BITS_PORT_INFO       0x0000f000      /* stupid port tricks */
 119 #define IO_BITS_KOTYPE          0x00000fff      /* used by the object */
 120 #define IO_BITS_OTYPE           0x7fff0000      /* determines a zone */
 121 #define IO_BITS_ACTIVE          0x80000000      /* is object alive? */
 122
 123 #define io_active(io)           ((io)->io_bits & IO_BITS_ACTIVE)
 124
 125 #define io_otype(io)            (((io)->io_bits & IO_BITS_OTYPE) >> 16)
 126 #define io_kotype(io)           ((io)->io_bits & IO_BITS_KOTYPE)
 127
 128 #define io_makebits(active, otype, kotype)      \
 129         (((active) ? IO_BITS_ACTIVE : 0) | ((otype) << 16) | (kotype))
 130
 131 /*
 132  * Object types: ports, port sets, kernel-loaded ports
 133  */
 134 #define IOT_PORT                0
 135 #define IOT_PORT_SET            1
 136 #define IOT_NUMBER              2               /* number of types used */
 137
 138 extern zone_t ipc_object_zones[IOT_NUMBER];
 139
 140 #define io_alloc(otype)         \
 141                 ((ipc_object_t) zalloc(ipc_object_zones[(otype)]))
 142
 143 #if     MACH_ASSERT
 144 /*
 145  *      Call the routine for io_free so that checking can be performed.
 146  */
 147 extern void     io_free(
 148                         unsigned int    otype,
 149                         ipc_object_t    object);
 150
 151 #else   /* MACH_ASSERT */
 152 #define io_free(otype, io)      \
 153                 zfree(ipc_object_zones[(otype)], (vm_offset_t) (io))
 154 #endif  /* MACH_ASSERT */
 155
 156 /*
 157  * Here we depend on the ipc_object being first within the ipc_common_data,
 158  * which is first within the rpc_common_data, which in turn must be first
 159  * within any kernel data structure needing to lock an ipc_object
 160  * (ipc_port and ipc_pset).
 161  */
 162 #if     NCPUS == 1
 163
 164 #define io_lock_init(io) \
 165         usimple_lock_init(&(io)-io_lock_data, ETAP_IPC_OBJECT)
 166 #define io_lock(io) \
 167         usimple_lock(&(io)->io_lock_data)
 168 #define io_lock_try(io) \
 169         usimple_lock_try(&(io)->io_lock_data)
 170 #define io_unlock(io) \
 171         usimple_unlock(&(io)->io_lock_data)
 172
 173 #else   /* NCPUS == 1 */
 174
 175 #define io_lock_init(io) \
 176         mutex_init(&(io)->io_lock_data, ETAP_IPC_OBJECT)
 177 #define io_lock(io) \
 178         mutex_lock(&(io)->io_lock_data)
 179 #define io_lock_try(io) \
 180         mutex_try(&(io)->io_lock_data)
 181 #define io_unlock(io) \
 182         mutex_unlock(&(io)->io_lock_data)
 183
 184 #endif  /* NCPUS == 1 */
 185
 186 #if     NCPUS > 1
 187 #define _VOLATILE_ volatile
 188 #else   /* NCPUS > 1 */
 189 #define _VOLATILE_
 190 #endif  /* NCPUS > 1 */
 191
 192 #define io_check_unlock(io)                                             \
 193 MACRO_BEGIN                                                             \
 194         _VOLATILE_ ipc_object_refs_t _refs = (io)->io_references;       \
 195                                                                         \
 196         io_unlock(io);                                                  \
 197         if (_refs == 0)                                                 \
 198                 io_free(io_otype(io), io);                              \
 199 MACRO_END
 200
 201 /* Sanity check the ref count.  If it is 0, we may be doubly zfreeing.
 202  * If it is larger than max int, it has been corrupted, probably by being
 203  * modified into an address (this is architecture dependent, but it's
 204  * safe to assume there cannot really be max int references).
 205  *
 206  * NOTE: The 0 test alone will not catch double zfreeing of ipc_port
 207  * structs, because the io_references field is the first word of the struct,
 208  * and zfree modifies that to point to the next free zone element.
 209  */
 210 #define IO_MAX_REFERENCES                                               \
 211         (unsigned)(~0 ^ (1 << (sizeof(int)*BYTE_SIZE - 1)))
 212
 213 #define io_reference(io)                                                \
 214 MACRO_BEGIN                                                             \
 215         assert((io)->io_references < IO_MAX_REFERENCES);                \
 216         (io)->io_references++;                                          \
 217 MACRO_END
 218
 219 #define io_release(io)                                                  \
 220 MACRO_BEGIN                                                             \
 221         assert((io)->io_references > 0 &&                               \
 222                     (io)->io_references <= IO_MAX_REFERENCES);          \
 223         (io)->io_references--;                                          \
 224 MACRO_END
 225
 226 /*
 227  * Exported interfaces
 228  */
 229
 230 /* Take a reference to an object */
 231 extern void ipc_object_reference(
 232         ipc_object_t    object);
 233
 234 /* Release a reference to an object */
 235 extern void ipc_object_release(
 236         ipc_object_t    object);
 237
 238 /* Look up an object in a space */
 239 extern kern_return_t ipc_object_translate(
 240         ipc_space_t             space,
 241         mach_port_name_t        name,
 242         mach_port_right_t       right,
 243         ipc_object_t            *objectp);
 244
 245 /* Look up two objects in a space, locking them in the order described */
 246 extern kern_return_t ipc_object_translate_two(
 247         ipc_space_t             space,
 248         mach_port_name_t        name1,
 249         mach_port_right_t       right1,
 250         ipc_object_t            *objectp1,
 251         mach_port_name_t        name2,
 252         mach_port_right_t       right2,
 253         ipc_object_t            *objectp2);
 254
 255 /* Allocate a dead-name entry */
 256 extern kern_return_t
 257 ipc_object_alloc_dead(
 258         ipc_space_t             space,
 259         mach_port_name_t        *namep);
 260
 261 /*  Allocate a dead-name entry, with a specific name */
 262 extern kern_return_t ipc_object_alloc_dead_name(
 263         ipc_space_t             space,
 264         mach_port_name_t        name);
 265
 266 /* Allocate an object */
 267 extern kern_return_t ipc_object_alloc(
 268         ipc_space_t             space,
 269         ipc_object_type_t       otype,
 270         mach_port_type_t        type,
 271         mach_port_urefs_t       urefs,
 272         mach_port_name_t        *namep,
 273         ipc_object_t            *objectp);
 274
 275 /* Allocate an object, with a specific name */
 276 extern kern_return_t ipc_object_alloc_name(
 277         ipc_space_t             space,
 278         ipc_object_type_t       otype,
 279         mach_port_type_t        type,
 280         mach_port_urefs_t       urefs,
 281         mach_port_name_t        name,
 282         ipc_object_t            *objectp);
 283
 284 /* Convert a send type name to a received type name */
 285 extern mach_msg_type_name_t ipc_object_copyin_type(
 286         mach_msg_type_name_t    msgt_name);
 287
 288 /* Copyin a capability from a space */
 289 extern kern_return_t ipc_object_copyin(
 290         ipc_space_t             space,
 291         mach_port_name_t        name,
 292         mach_msg_type_name_t    msgt_name,
 293         ipc_object_t            *objectp);
 294
 295 /* Copyin a naked capability from the kernel */
 296 extern void ipc_object_copyin_from_kernel(
 297         ipc_object_t            object,
 298         mach_msg_type_name_t    msgt_name);
 299
 300 /* Destroy a naked capability */
 301 extern void ipc_object_destroy(
 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 #if     MACH_KDB
 335 /* Pretty-print an ipc object */
 336
 337 extern void ipc_object_print(
 338         ipc_object_t    object);
 339
 340 #endif  /* MACH_KDB */
 341
 342 #endif  /* _IPC_IPC_OBJECT_H_ */