osfmk/ipc/ipc_object.h

   1 /*
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   8  * This file contains Original Code and/or Modifications of Original Code
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  10  * Version 2.0 (the 'License'). You may not use this file except in
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  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
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  25 /*
  26  * @OSF_COPYRIGHT@
  27  */
  28 /*
  29  * Mach Operating System
  30  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  31  * All Rights Reserved.
  32  *
  33  * Permission to use, copy, modify and distribute this software and its
  34  * documentation is hereby granted, provided that both the copyright
  35  * notice and this permission notice appear in all copies of the
  36  * software, derivative works or modified versions, and any portions
  37  * thereof, and that both notices appear in supporting documentation.
  38  *
  39  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  40  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  41  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  42  *
  43  * Carnegie Mellon requests users of this software to return to
  44  *
  45  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  46  *  School of Computer Science
  47  *  Carnegie Mellon University
  48  *  Pittsburgh PA 15213-3890
  49  *
  50  * any improvements or extensions that they make and grant Carnegie Mellon
  51  * the rights to redistribute these changes.
  52  */
  53 /*
  54  */
  55 /*
  56  *      File:   ipc/ipc_object.h
  57  *      Author: Rich Draves
  58  *      Date:   1989
  59  *
  60  *      Definitions for IPC objects, for which tasks have capabilities.
  61  */
  62
  63 #ifndef _IPC_IPC_OBJECT_H_
  64 #define _IPC_IPC_OBJECT_H_
  65
  66 #include <mach_rt.h>
  67 #include <cpus.h>
  68 #include <mach_kdb.h>
  69
  70 #include <mach/kern_return.h>
  71 #include <mach/message.h>
  72 #include <kern/lock.h>
  73 #include <kern/macro_help.h>
  74 #include <kern/zalloc.h>
  75 #include <ipc/ipc_types.h>
  76
  77 typedef natural_t ipc_object_refs_t;    /* for ipc/ipc_object.h         */
  78 typedef natural_t ipc_object_bits_t;
  79 typedef natural_t ipc_object_type_t;
  80
  81 /*
  82  * There is no lock in the ipc_object; it is in the enclosing kernel
  83  * data structure (rpc_common_data) used by both ipc_port and ipc_pset.
  84  * The ipc_object is used to both tag and reference count these two data
  85  * structures, and (Noto Bene!) pointers to either of these or the
  86  * ipc_object at the head of these are freely cast back and forth; hence
  87  * the ipc_object MUST BE FIRST in the ipc_common_data.
  88  *
  89  * If the RPC implementation enabled user-mode code to use kernel-level
  90  * data structures (as ours used to), this peculiar structuring would
  91  * avoid having anything in user code depend on the kernel configuration
  92  * (with which lock size varies).
  93  */
  94 struct ipc_object {
  95         ipc_object_refs_t io_references;
  96         ipc_object_bits_t io_bits;
  97         port_name_t       io_receiver_name;
  98 #if NCPUS == 1
  99         usimple_lock_data_t     io_lock_data;
 100 #else
 101         decl_mutex_data(,       io_lock_data)
 102 #endif
 103 };
 104
 105 /*
 106  * Legacy defines.  Should use IPC_OBJECT_NULL, etc...
 107  */
 108 #define IO_NULL                 ((ipc_object_t) 0)
 109 #define IO_DEAD                 ((ipc_object_t) -1)
 110 #define IO_VALID(io)            (((io) != IO_NULL) && ((io) != IO_DEAD))
 111
 112 /*
 113  *      IPC steals the high-order bits from the kotype to use
 114  *      for its own purposes.  This allows IPC to record facts
 115  *      about ports that aren't otherwise obvious from the
 116  *      existing port fields.  In particular, IPC can optionally
 117  *      mark a port for no more senders detection.  Any change
 118  *      to IO_BITS_PORT_INFO must be coordinated with bitfield
 119  *      definitions in ipc_port.h.
 120  */
 121 #define IO_BITS_PORT_INFO       0x0000f000      /* stupid port tricks */
 122 #define IO_BITS_KOTYPE          0x00000fff      /* used by the object */
 123 #define IO_BITS_OTYPE           0x7fff0000      /* determines a zone */
 124 #define IO_BITS_ACTIVE          0x80000000      /* is object alive? */
 125
 126 #define io_active(io)           ((io)->io_bits & IO_BITS_ACTIVE)
 127
 128 #define io_otype(io)            (((io)->io_bits & IO_BITS_OTYPE) >> 16)
 129 #define io_kotype(io)           ((io)->io_bits & IO_BITS_KOTYPE)
 130
 131 #define io_makebits(active, otype, kotype)      \
 132         (((active) ? IO_BITS_ACTIVE : 0) | ((otype) << 16) | (kotype))
 133
 134 /*
 135  * Object types: ports, port sets, kernel-loaded ports
 136  */
 137 #define IOT_PORT                0
 138 #define IOT_PORT_SET            1
 139 #define IOT_NUMBER              2               /* number of types used */
 140
 141 extern zone_t ipc_object_zones[IOT_NUMBER];
 142
 143 #define io_alloc(otype)         \
 144                 ((ipc_object_t) zalloc(ipc_object_zones[(otype)]))
 145
 146 #if     MACH_ASSERT
 147 /*
 148  *      Call the routine for io_free so that checking can be performed.
 149  */
 150 extern void     io_free(
 151                         unsigned int    otype,
 152                         ipc_object_t    object);
 153
 154 #else   /* MACH_ASSERT */
 155 #define io_free(otype, io)      \
 156                 zfree(ipc_object_zones[(otype)], (vm_offset_t) (io))
 157 #endif  /* MACH_ASSERT */
 158
 159 /*
 160  * Here we depend on the ipc_object being first within the ipc_common_data,
 161  * which is first within the rpc_common_data, which in turn must be first
 162  * within any kernel data structure needing to lock an ipc_object
 163  * (ipc_port and ipc_pset).
 164  */
 165 #if     NCPUS == 1
 166
 167 #define io_lock_init(io) \
 168         usimple_lock_init(&(io)-io_lock_data, ETAP_IPC_OBJECT)
 169 #define io_lock(io) \
 170         usimple_lock(&(io)->io_lock_data)
 171 #define io_lock_try(io) \
 172         usimple_lock_try(&(io)->io_lock_data)
 173 #define io_unlock(io) \
 174         usimple_unlock(&(io)->io_lock_data)
 175
 176 #else   /* NCPUS == 1 */
 177
 178 #define io_lock_init(io) \
 179         mutex_init(&(io)->io_lock_data, ETAP_IPC_OBJECT)
 180 #define io_lock(io) \
 181         mutex_lock(&(io)->io_lock_data)
 182 #define io_lock_try(io) \
 183         mutex_try(&(io)->io_lock_data)
 184 #define io_unlock(io) \
 185         mutex_unlock(&(io)->io_lock_data)
 186
 187 #endif  /* NCPUS == 1 */
 188
 189 #if     NCPUS > 1
 190 #define _VOLATILE_ volatile
 191 #else   /* NCPUS > 1 */
 192 #define _VOLATILE_
 193 #endif  /* NCPUS > 1 */
 194
 195 #define io_check_unlock(io)                                             \
 196 MACRO_BEGIN                                                             \
 197         _VOLATILE_ ipc_object_refs_t _refs = (io)->io_references;       \
 198                                                                         \
 199         io_unlock(io);                                                  \
 200         if (_refs == 0)                                                 \
 201                 io_free(io_otype(io), io);                              \
 202 MACRO_END
 203
 204 /* Sanity check the ref count.  If it is 0, we may be doubly zfreeing.
 205  * If it is larger than max int, it has been corrupted, probably by being
 206  * modified into an address (this is architecture dependent, but it's
 207  * safe to assume there cannot really be max int references).
 208  *
 209  * NOTE: The 0 test alone will not catch double zfreeing of ipc_port
 210  * structs, because the io_references field is the first word of the struct,
 211  * and zfree modifies that to point to the next free zone element.
 212  */
 213 #define IO_MAX_REFERENCES                                               \
 214         (unsigned)(~0 ^ (1 << (sizeof(int)*BYTE_SIZE - 1)))
 215
 216 #define io_reference(io)                                                \
 217 MACRO_BEGIN                                                             \
 218         assert((io)->io_references < IO_MAX_REFERENCES);                \
 219         (io)->io_references++;                                          \
 220 MACRO_END
 221
 222 #define io_release(io)                                                  \
 223 MACRO_BEGIN                                                             \
 224         assert((io)->io_references > 0 &&                               \
 225                     (io)->io_references <= IO_MAX_REFERENCES);          \
 226         (io)->io_references--;                                          \
 227 MACRO_END
 228
 229 /*
 230  * Exported interfaces
 231  */
 232
 233 /* Take a reference to an object */
 234 extern void ipc_object_reference(
 235         ipc_object_t    object);
 236
 237 /* Release a reference to an object */
 238 extern void ipc_object_release(
 239         ipc_object_t    object);
 240
 241 /* Look up an object in a space */
 242 extern kern_return_t ipc_object_translate(
 243         ipc_space_t             space,
 244         mach_port_name_t        name,
 245         mach_port_right_t       right,
 246         ipc_object_t            *objectp);
 247
 248 /* Look up two objects in a space, locking them in the order described */
 249 extern kern_return_t ipc_object_translate_two(
 250         ipc_space_t             space,
 251         mach_port_name_t        name1,
 252         mach_port_right_t       right1,
 253         ipc_object_t            *objectp1,
 254         mach_port_name_t        name2,
 255         mach_port_right_t       right2,
 256         ipc_object_t            *objectp2);
 257
 258 /* Allocate a dead-name entry */
 259 extern kern_return_t
 260 ipc_object_alloc_dead(
 261         ipc_space_t             space,
 262         mach_port_name_t        *namep);
 263
 264 /*  Allocate a dead-name entry, with a specific name */
 265 extern kern_return_t ipc_object_alloc_dead_name(
 266         ipc_space_t             space,
 267         mach_port_name_t        name);
 268
 269 /* Allocate an object */
 270 extern kern_return_t ipc_object_alloc(
 271         ipc_space_t             space,
 272         ipc_object_type_t       otype,
 273         mach_port_type_t        type,
 274         mach_port_urefs_t       urefs,
 275         mach_port_name_t        *namep,
 276         ipc_object_t            *objectp);
 277
 278 /* Allocate an object, with a specific name */
 279 extern kern_return_t ipc_object_alloc_name(
 280         ipc_space_t             space,
 281         ipc_object_type_t       otype,
 282         mach_port_type_t        type,
 283         mach_port_urefs_t       urefs,
 284         mach_port_name_t        name,
 285         ipc_object_t            *objectp);
 286
 287 /* Convert a send type name to a received type name */
 288 extern mach_msg_type_name_t ipc_object_copyin_type(
 289         mach_msg_type_name_t    msgt_name);
 290
 291 /* Copyin a capability from a space */
 292 extern kern_return_t ipc_object_copyin(
 293         ipc_space_t             space,
 294         mach_port_name_t        name,
 295         mach_msg_type_name_t    msgt_name,
 296         ipc_object_t            *objectp);
 297
 298 /* Copyin a naked capability from the kernel */
 299 extern void ipc_object_copyin_from_kernel(
 300         ipc_object_t            object,
 301         mach_msg_type_name_t    msgt_name);
 302
 303 /* Destroy a naked capability */
 304 extern void ipc_object_destroy(
 305         ipc_object_t            object,
 306         mach_msg_type_name_t    msgt_name);
 307
 308 /* Copyout a capability, placing it into a space */
 309 extern kern_return_t ipc_object_copyout(
 310         ipc_space_t             space,
 311         ipc_object_t            object,
 312         mach_msg_type_name_t    msgt_name,
 313         boolean_t               overflow,
 314         mach_port_name_t        *namep);
 315
 316 /* Copyout a capability with a name, placing it into a space */
 317 extern kern_return_t ipc_object_copyout_name(
 318         ipc_space_t             space,
 319         ipc_object_t            object,
 320         mach_msg_type_name_t    msgt_name,
 321         boolean_t               overflow,
 322         mach_port_name_t        name);
 323
 324 /* Translate/consume the destination right of a message */
 325 extern void ipc_object_copyout_dest(
 326         ipc_space_t             space,
 327         ipc_object_t            object,
 328         mach_msg_type_name_t    msgt_name,
 329         mach_port_name_t        *namep);
 330
 331 /* Rename an entry in a space */
 332 extern kern_return_t ipc_object_rename(
 333         ipc_space_t             space,
 334         mach_port_name_t        oname,
 335         mach_port_name_t        nname);
 336
 337 #if     MACH_KDB
 338 /* Pretty-print an ipc object */
 339
 340 extern void ipc_object_print(
 341         ipc_object_t    object);
 342
 343 #endif  /* MACH_KDB */
 344
 345 #endif  /* _IPC_IPC_OBJECT_H_ */