osfmk/ipc/ipc_object.h

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   6  * The contents of this file constitute Original Code as defined in and
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  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 <mach_kdb.h>
  65
  66 #include <mach/kern_return.h>
  67 #include <mach/message.h>
  68 #include <kern/lock.h>
  69 #include <kern/macro_help.h>
  70 #include <kern/zalloc.h>
  71 #include <ipc/ipc_types.h>
  72
  73 typedef natural_t ipc_object_refs_t;    /* for ipc/ipc_object.h         */
  74 typedef natural_t ipc_object_bits_t;
  75 typedef natural_t ipc_object_type_t;
  76
  77 /*
  78  * There is no lock in the ipc_object; it is in the enclosing kernel
  79  * data structure (rpc_common_data) used by both ipc_port and ipc_pset.
  80  * The ipc_object is used to both tag and reference count these two data
  81  * structures, and (Noto Bene!) pointers to either of these or the
  82  * ipc_object at the head of these are freely cast back and forth; hence
  83  * the ipc_object MUST BE FIRST in the ipc_common_data.
  84  *
  85  * If the RPC implementation enabled user-mode code to use kernel-level
  86  * data structures (as ours used to), this peculiar structuring would
  87  * avoid having anything in user code depend on the kernel configuration
  88  * (with which lock size varies).
  89  */
  90 struct ipc_object {
  91         ipc_object_refs_t io_references;
  92         ipc_object_bits_t io_bits;
  93         mach_port_name_t  io_receiver_name;
  94         decl_mutex_data(,       io_lock_data)
  95 };
  96
  97 /*
  98  * Legacy defines.  Should use IPC_OBJECT_NULL, etc...
  99  */
 100 #define IO_NULL                 ((ipc_object_t) 0)
 101 #define IO_DEAD                 ((ipc_object_t) -1)
 102 #define IO_VALID(io)            (((io) != IO_NULL) && ((io) != IO_DEAD))
 103
 104 /*
 105  *      IPC steals the high-order bits from the kotype to use
 106  *      for its own purposes.  This allows IPC to record facts
 107  *      about ports that aren't otherwise obvious from the
 108  *      existing port fields.  In particular, IPC can optionally
 109  *      mark a port for no more senders detection.  Any change
 110  *      to IO_BITS_PORT_INFO must be coordinated with bitfield
 111  *      definitions in ipc_port.h.
 112  */
 113 #define IO_BITS_PORT_INFO       0x0000f000      /* stupid port tricks */
 114 #define IO_BITS_KOTYPE          0x00000fff      /* used by the object */
 115 #define IO_BITS_OTYPE           0x7fff0000      /* determines a zone */
 116 #define IO_BITS_ACTIVE          0x80000000      /* is object alive? */
 117
 118 #define io_active(io)           ((io)->io_bits & IO_BITS_ACTIVE)
 119
 120 #define io_otype(io)            (((io)->io_bits & IO_BITS_OTYPE) >> 16)
 121 #define io_kotype(io)           ((io)->io_bits & IO_BITS_KOTYPE)
 122
 123 #define io_makebits(active, otype, kotype)      \
 124         (((active) ? IO_BITS_ACTIVE : 0) | ((otype) << 16) | (kotype))
 125
 126 /*
 127  * Object types: ports, port sets, kernel-loaded ports
 128  */
 129 #define IOT_PORT                0
 130 #define IOT_PORT_SET            1
 131 #define IOT_NUMBER              2               /* number of types used */
 132
 133 extern zone_t ipc_object_zones[IOT_NUMBER];
 134
 135 #define io_alloc(otype)         \
 136                 ((ipc_object_t) zalloc(ipc_object_zones[(otype)]))
 137
 138 #if     MACH_ASSERT
 139 /*
 140  *      Call the routine for io_free so that checking can be performed.
 141  */
 142 extern void     io_free(
 143                         unsigned int    otype,
 144                         ipc_object_t    object);
 145
 146 #else   /* MACH_ASSERT */
 147 #define io_free(otype, io)      \
 148                 zfree(ipc_object_zones[(otype)], (io))
 149 #endif  /* MACH_ASSERT */
 150
 151 /*
 152  * Here we depend on the ipc_object being first within the ipc_common_data,
 153  * which is first within the rpc_common_data, which in turn must be first
 154  * within any kernel data structure needing to lock an ipc_object
 155  * (ipc_port and ipc_pset).
 156  */
 157 #define io_lock_init(io) \
 158         mutex_init(&(io)->io_lock_data, 0)
 159 #define io_lock(io) \
 160         mutex_lock(&(io)->io_lock_data)
 161 #define io_lock_try(io) \
 162         mutex_try(&(io)->io_lock_data)
 163 #define io_unlock(io) \
 164         mutex_unlock(&(io)->io_lock_data)
 165
 166 #define _VOLATILE_ volatile
 167
 168 #define io_check_unlock(io)                                             \
 169 MACRO_BEGIN                                                             \
 170         _VOLATILE_ ipc_object_refs_t _refs = (io)->io_references;       \
 171                                                                         \
 172         io_unlock(io);                                                  \
 173         if (_refs == 0)                                                 \
 174                 io_free(io_otype(io), io);                              \
 175 MACRO_END
 176
 177 /* Sanity check the ref count.  If it is 0, we may be doubly zfreeing.
 178  * If it is larger than max int, it has been corrupted, probably by being
 179  * modified into an address (this is architecture dependent, but it's
 180  * safe to assume there cannot really be max int references).
 181  *
 182  * NOTE: The 0 test alone will not catch double zfreeing of ipc_port
 183  * structs, because the io_references field is the first word of the struct,
 184  * and zfree modifies that to point to the next free zone element.
 185  */
 186 #define IO_MAX_REFERENCES                                               \
 187         (unsigned)(~0 ^ (1 << (sizeof(int)*BYTE_SIZE - 1)))
 188
 189 #define io_reference(io)                                                \
 190 MACRO_BEGIN                                                             \
 191         assert((io)->io_references < IO_MAX_REFERENCES);                \
 192         (io)->io_references++;                                          \
 193 MACRO_END
 194
 195 #define io_release(io)                                                  \
 196 MACRO_BEGIN                                                             \
 197         assert((io)->io_references > 0 &&                               \
 198                     (io)->io_references <= IO_MAX_REFERENCES);          \
 199         (io)->io_references--;                                          \
 200 MACRO_END
 201
 202 /*
 203  * Exported interfaces
 204  */
 205
 206 /* Take a reference to an object */
 207 extern void ipc_object_reference(
 208         ipc_object_t    object);
 209
 210 /* Release a reference to an object */
 211 extern void ipc_object_release(
 212         ipc_object_t    object);
 213
 214 /* Look up an object in a space */
 215 extern kern_return_t ipc_object_translate(
 216         ipc_space_t             space,
 217         mach_port_name_t        name,
 218         mach_port_right_t       right,
 219         ipc_object_t            *objectp);
 220
 221 /* Look up two objects in a space, locking them in the order described */
 222 extern kern_return_t ipc_object_translate_two(
 223         ipc_space_t             space,
 224         mach_port_name_t        name1,
 225         mach_port_right_t       right1,
 226         ipc_object_t            *objectp1,
 227         mach_port_name_t        name2,
 228         mach_port_right_t       right2,
 229         ipc_object_t            *objectp2);
 230
 231 /* Allocate a dead-name entry */
 232 extern kern_return_t
 233 ipc_object_alloc_dead(
 234         ipc_space_t             space,
 235         mach_port_name_t        *namep);
 236
 237 /*  Allocate a dead-name entry, with a specific name */
 238 extern kern_return_t ipc_object_alloc_dead_name(
 239         ipc_space_t             space,
 240         mach_port_name_t        name);
 241
 242 /* Allocate an object */
 243 extern kern_return_t ipc_object_alloc(
 244         ipc_space_t             space,
 245         ipc_object_type_t       otype,
 246         mach_port_type_t        type,
 247         mach_port_urefs_t       urefs,
 248         mach_port_name_t        *namep,
 249         ipc_object_t            *objectp);
 250
 251 /* Allocate an object, with a specific name */
 252 extern kern_return_t ipc_object_alloc_name(
 253         ipc_space_t             space,
 254         ipc_object_type_t       otype,
 255         mach_port_type_t        type,
 256         mach_port_urefs_t       urefs,
 257         mach_port_name_t        name,
 258         ipc_object_t            *objectp);
 259
 260 /* Convert a send type name to a received type name */
 261 extern mach_msg_type_name_t ipc_object_copyin_type(
 262         mach_msg_type_name_t    msgt_name);
 263
 264 /* Copyin a capability from a space */
 265 extern kern_return_t ipc_object_copyin(
 266         ipc_space_t             space,
 267         mach_port_name_t        name,
 268         mach_msg_type_name_t    msgt_name,
 269         ipc_object_t            *objectp);
 270
 271 /* Copyin a naked capability from the kernel */
 272 extern void ipc_object_copyin_from_kernel(
 273         ipc_object_t            object,
 274         mach_msg_type_name_t    msgt_name);
 275
 276 /* Destroy a naked capability */
 277 extern void ipc_object_destroy(
 278         ipc_object_t            object,
 279         mach_msg_type_name_t    msgt_name);
 280
 281 /* Copyout a capability, placing it into a space */
 282 extern kern_return_t ipc_object_copyout(
 283         ipc_space_t             space,
 284         ipc_object_t            object,
 285         mach_msg_type_name_t    msgt_name,
 286         boolean_t               overflow,
 287         mach_port_name_t        *namep);
 288
 289 /* Copyout a capability with a name, placing it into a space */
 290 extern kern_return_t ipc_object_copyout_name(
 291         ipc_space_t             space,
 292         ipc_object_t            object,
 293         mach_msg_type_name_t    msgt_name,
 294         boolean_t               overflow,
 295         mach_port_name_t        name);
 296
 297 /* Translate/consume the destination right of a message */
 298 extern void ipc_object_copyout_dest(
 299         ipc_space_t             space,
 300         ipc_object_t            object,
 301         mach_msg_type_name_t    msgt_name,
 302         mach_port_name_t        *namep);
 303
 304 /* Rename an entry in a space */
 305 extern kern_return_t ipc_object_rename(
 306         ipc_space_t             space,
 307         mach_port_name_t        oname,
 308         mach_port_name_t        nname);
 309
 310 #if     MACH_KDB
 311 /* Pretty-print an ipc object */
 312
 313 extern void ipc_object_print(
 314         ipc_object_t    object);
 315
 316 #endif  /* MACH_KDB */
 317
 318 #endif  /* _IPC_IPC_OBJECT_H_ */