osfmk/ipc/ipc_object.h

   1 /*
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   6  * This file contains Original Code and/or Modifications of Original Code
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  10  * http://www.opensource.apple.com/apsl/ and read it before using this
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  23 /*
  24  * @OSF_COPYRIGHT@
  25  */
  26 /*
  27  * Mach Operating System
  28  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  29  * All Rights Reserved.
  30  *
  31  * Permission to use, copy, modify and distribute this software and its
  32  * documentation is hereby granted, provided that both the copyright
  33  * notice and this permission notice appear in all copies of the
  34  * software, derivative works or modified versions, and any portions
  35  * thereof, and that both notices appear in supporting documentation.
  36  *
  37  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  38  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  39  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  40  *
  41  * Carnegie Mellon requests users of this software to return to
  42  *
  43  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  44  *  School of Computer Science
  45  *  Carnegie Mellon University
  46  *  Pittsburgh PA 15213-3890
  47  *
  48  * any improvements or extensions that they make and grant Carnegie Mellon
  49  * the rights to redistribute these changes.
  50  */
  51 /*
  52  */
  53 /*
  54  *      File:   ipc/ipc_object.h
  55  *      Author: Rich Draves
  56  *      Date:   1989
  57  *
  58  *      Definitions for IPC objects, for which tasks have capabilities.
  59  */
  60
  61 #ifndef _IPC_IPC_OBJECT_H_
  62 #define _IPC_IPC_OBJECT_H_
  63
  64 #include <mach_rt.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         mach_port_name_t  io_receiver_name;
  95         decl_mutex_data(,       io_lock_data)
  96 };
  97
  98 /*
  99  * Legacy defines.  Should use IPC_OBJECT_NULL, etc...
 100  */
 101 #define IO_NULL                 ((ipc_object_t) 0)
 102 #define IO_DEAD                 ((ipc_object_t) -1)
 103 #define IO_VALID(io)            (((io) != IO_NULL) && ((io) != IO_DEAD))
 104
 105 /*
 106  *      IPC steals the high-order bits from the kotype to use
 107  *      for its own purposes.  This allows IPC to record facts
 108  *      about ports that aren't otherwise obvious from the
 109  *      existing port fields.  In particular, IPC can optionally
 110  *      mark a port for no more senders detection.  Any change
 111  *      to IO_BITS_PORT_INFO must be coordinated with bitfield
 112  *      definitions in ipc_port.h.
 113  */
 114 #define IO_BITS_PORT_INFO       0x0000f000      /* stupid port tricks */
 115 #define IO_BITS_KOTYPE          0x00000fff      /* used by the object */
 116 #define IO_BITS_OTYPE           0x7fff0000      /* determines a zone */
 117 #define IO_BITS_ACTIVE          0x80000000      /* is object alive? */
 118
 119 #define io_active(io)           ((io)->io_bits & IO_BITS_ACTIVE)
 120
 121 #define io_otype(io)            (((io)->io_bits & IO_BITS_OTYPE) >> 16)
 122 #define io_kotype(io)           ((io)->io_bits & IO_BITS_KOTYPE)
 123
 124 #define io_makebits(active, otype, kotype)      \
 125         (((active) ? IO_BITS_ACTIVE : 0) | ((otype) << 16) | (kotype))
 126
 127 /*
 128  * Object types: ports, port sets, kernel-loaded ports
 129  */
 130 #define IOT_PORT                0
 131 #define IOT_PORT_SET            1
 132 #define IOT_NUMBER              2               /* number of types used */
 133
 134 extern zone_t ipc_object_zones[IOT_NUMBER];
 135
 136 #define io_alloc(otype)         \
 137                 ((ipc_object_t) zalloc(ipc_object_zones[(otype)]))
 138
 139 #if     MACH_ASSERT
 140 /*
 141  *      Call the routine for io_free so that checking can be performed.
 142  */
 143 extern void     io_free(
 144                         unsigned int    otype,
 145                         ipc_object_t    object);
 146
 147 #else   /* MACH_ASSERT */
 148 #define io_free(otype, io)      \
 149                 zfree(ipc_object_zones[(otype)], (io))
 150 #endif  /* MACH_ASSERT */
 151
 152 /*
 153  * Here we depend on the ipc_object being first within the ipc_common_data,
 154  * which is first within the rpc_common_data, which in turn must be first
 155  * within any kernel data structure needing to lock an ipc_object
 156  * (ipc_port and ipc_pset).
 157  */
 158 #define io_lock_init(io) \
 159         mutex_init(&(io)->io_lock_data, 0)
 160 #define io_lock(io) \
 161         mutex_lock(&(io)->io_lock_data)
 162 #define io_lock_try(io) \
 163         mutex_try(&(io)->io_lock_data)
 164 #define io_unlock(io) \
 165         mutex_unlock(&(io)->io_lock_data)
 166
 167 #define _VOLATILE_ volatile
 168
 169 #define io_check_unlock(io)                                             \
 170 MACRO_BEGIN                                                             \
 171         _VOLATILE_ ipc_object_refs_t _refs = (io)->io_references;       \
 172                                                                         \
 173         io_unlock(io);                                                  \
 174         if (_refs == 0)                                                 \
 175                 io_free(io_otype(io), io);                              \
 176 MACRO_END
 177
 178 /* Sanity check the ref count.  If it is 0, we may be doubly zfreeing.
 179  * If it is larger than max int, it has been corrupted, probably by being
 180  * modified into an address (this is architecture dependent, but it's
 181  * safe to assume there cannot really be max int references).
 182  *
 183  * NOTE: The 0 test alone will not catch double zfreeing of ipc_port
 184  * structs, because the io_references field is the first word of the struct,
 185  * and zfree modifies that to point to the next free zone element.
 186  */
 187 #define IO_MAX_REFERENCES                                               \
 188         (unsigned)(~0 ^ (1 << (sizeof(int)*BYTE_SIZE - 1)))
 189
 190 #define io_reference(io)                                                \
 191 MACRO_BEGIN                                                             \
 192         assert((io)->io_references < IO_MAX_REFERENCES);                \
 193         (io)->io_references++;                                          \
 194 MACRO_END
 195
 196 #define io_release(io)                                                  \
 197 MACRO_BEGIN                                                             \
 198         assert((io)->io_references > 0 &&                               \
 199                     (io)->io_references <= IO_MAX_REFERENCES);          \
 200         (io)->io_references--;                                          \
 201 MACRO_END
 202
 203 /*
 204  * Exported interfaces
 205  */
 206
 207 /* Take a reference to an object */
 208 extern void ipc_object_reference(
 209         ipc_object_t    object);
 210
 211 /* Release a reference to an object */
 212 extern void ipc_object_release(
 213         ipc_object_t    object);
 214
 215 /* Look up an object in a space */
 216 extern kern_return_t ipc_object_translate(
 217         ipc_space_t             space,
 218         mach_port_name_t        name,
 219         mach_port_right_t       right,
 220         ipc_object_t            *objectp);
 221
 222 /* Look up two objects in a space, locking them in the order described */
 223 extern kern_return_t ipc_object_translate_two(
 224         ipc_space_t             space,
 225         mach_port_name_t        name1,
 226         mach_port_right_t       right1,
 227         ipc_object_t            *objectp1,
 228         mach_port_name_t        name2,
 229         mach_port_right_t       right2,
 230         ipc_object_t            *objectp2);
 231
 232 /* Allocate a dead-name entry */
 233 extern kern_return_t
 234 ipc_object_alloc_dead(
 235         ipc_space_t             space,
 236         mach_port_name_t        *namep);
 237
 238 /*  Allocate a dead-name entry, with a specific name */
 239 extern kern_return_t ipc_object_alloc_dead_name(
 240         ipc_space_t             space,
 241         mach_port_name_t        name);
 242
 243 /* Allocate an object */
 244 extern kern_return_t ipc_object_alloc(
 245         ipc_space_t             space,
 246         ipc_object_type_t       otype,
 247         mach_port_type_t        type,
 248         mach_port_urefs_t       urefs,
 249         mach_port_name_t        *namep,
 250         ipc_object_t            *objectp);
 251
 252 /* Allocate an object, with a specific name */
 253 extern kern_return_t ipc_object_alloc_name(
 254         ipc_space_t             space,
 255         ipc_object_type_t       otype,
 256         mach_port_type_t        type,
 257         mach_port_urefs_t       urefs,
 258         mach_port_name_t        name,
 259         ipc_object_t            *objectp);
 260
 261 /* Convert a send type name to a received type name */
 262 extern mach_msg_type_name_t ipc_object_copyin_type(
 263         mach_msg_type_name_t    msgt_name);
 264
 265 /* Copyin a capability from a space */
 266 extern kern_return_t ipc_object_copyin(
 267         ipc_space_t             space,
 268         mach_port_name_t        name,
 269         mach_msg_type_name_t    msgt_name,
 270         ipc_object_t            *objectp);
 271
 272 /* Copyin a naked capability from the kernel */
 273 extern void ipc_object_copyin_from_kernel(
 274         ipc_object_t            object,
 275         mach_msg_type_name_t    msgt_name);
 276
 277 /* Destroy a naked capability */
 278 extern void ipc_object_destroy(
 279         ipc_object_t            object,
 280         mach_msg_type_name_t    msgt_name);
 281
 282 /* Copyout a capability, placing it into a space */
 283 extern kern_return_t ipc_object_copyout(
 284         ipc_space_t             space,
 285         ipc_object_t            object,
 286         mach_msg_type_name_t    msgt_name,
 287         boolean_t               overflow,
 288         mach_port_name_t        *namep);
 289
 290 /* Copyout a capability with a name, placing it into a space */
 291 extern kern_return_t ipc_object_copyout_name(
 292         ipc_space_t             space,
 293         ipc_object_t            object,
 294         mach_msg_type_name_t    msgt_name,
 295         boolean_t               overflow,
 296         mach_port_name_t        name);
 297
 298 /* Translate/consume the destination right of a message */
 299 extern void ipc_object_copyout_dest(
 300         ipc_space_t             space,
 301         ipc_object_t            object,
 302         mach_msg_type_name_t    msgt_name,
 303         mach_port_name_t        *namep);
 304
 305 /* Rename an entry in a space */
 306 extern kern_return_t ipc_object_rename(
 307         ipc_space_t             space,
 308         mach_port_name_t        oname,
 309         mach_port_name_t        nname);
 310
 311 #if     MACH_KDB
 312 /* Pretty-print an ipc object */
 313
 314 extern void ipc_object_print(
 315         ipc_object_t    object);
 316
 317 #endif  /* MACH_KDB */
 318
 319 #endif  /* _IPC_IPC_OBJECT_H_ */