osfmk/ipc/ipc_object.h

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  30 /*
  31  * @OSF_COPYRIGHT@
  32  */
  33 /*
  34  * Mach Operating System
  35  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  36  * All Rights Reserved.
  37  *
  38  * Permission to use, copy, modify and distribute this software and its
  39  * documentation is hereby granted, provided that both the copyright
  40  * notice and this permission notice appear in all copies of the
  41  * software, derivative works or modified versions, and any portions
  42  * thereof, and that both notices appear in supporting documentation.
  43  *
  44  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  45  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  46  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  47  *
  48  * Carnegie Mellon requests users of this software to return to
  49  *
  50  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  51  *  School of Computer Science
  52  *  Carnegie Mellon University
  53  *  Pittsburgh PA 15213-3890
  54  *
  55  * any improvements or extensions that they make and grant Carnegie Mellon
  56  * the rights to redistribute these changes.
  57  */
  58 /*
  59  */
  60 /*
  61  *      File:   ipc/ipc_object.h
  62  *      Author: Rich Draves
  63  *      Date:   1989
  64  *
  65  *      Definitions for IPC objects, for which tasks have capabilities.
  66  */
  67
  68 #ifndef _IPC_IPC_OBJECT_H_
  69 #define _IPC_IPC_OBJECT_H_
  70
  71 #include <mach_rt.h>
  72 #include <mach_kdb.h>
  73
  74 #include <mach/kern_return.h>
  75 #include <mach/message.h>
  76 #include <kern/lock.h>
  77 #include <kern/macro_help.h>
  78 #include <kern/zalloc.h>
  79 #include <ipc/ipc_types.h>
  80
  81 typedef natural_t ipc_object_refs_t;    /* for ipc/ipc_object.h         */
  82 typedef natural_t ipc_object_bits_t;
  83 typedef natural_t ipc_object_type_t;
  84
  85 /*
  86  * There is no lock in the ipc_object; it is in the enclosing kernel
  87  * data structure (rpc_common_data) used by both ipc_port and ipc_pset.
  88  * The ipc_object is used to both tag and reference count these two data
  89  * structures, and (Noto Bene!) pointers to either of these or the
  90  * ipc_object at the head of these are freely cast back and forth; hence
  91  * the ipc_object MUST BE FIRST in the ipc_common_data.
  92  *
  93  * If the RPC implementation enabled user-mode code to use kernel-level
  94  * data structures (as ours used to), this peculiar structuring would
  95  * avoid having anything in user code depend on the kernel configuration
  96  * (with which lock size varies).
  97  */
  98 struct ipc_object {
  99         ipc_object_refs_t io_references;
 100         ipc_object_bits_t io_bits;
 101         mach_port_name_t  io_receiver_name;
 102         decl_mutex_data(,       io_lock_data)
 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)], (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 #define io_lock_init(io) \
 166         mutex_init(&(io)->io_lock_data, 0)
 167 #define io_lock(io) \
 168         mutex_lock(&(io)->io_lock_data)
 169 #define io_lock_try(io) \
 170         mutex_try(&(io)->io_lock_data)
 171 #define io_unlock(io) \
 172         mutex_unlock(&(io)->io_lock_data)
 173
 174 #define _VOLATILE_ volatile
 175
 176 #define io_check_unlock(io)                                             \
 177 MACRO_BEGIN                                                             \
 178         _VOLATILE_ ipc_object_refs_t _refs = (io)->io_references;       \
 179                                                                         \
 180         io_unlock(io);                                                  \
 181         if (_refs == 0)                                                 \
 182                 io_free(io_otype(io), io);                              \
 183 MACRO_END
 184
 185 /* Sanity check the ref count.  If it is 0, we may be doubly zfreeing.
 186  * If it is larger than max int, it has been corrupted, probably by being
 187  * modified into an address (this is architecture dependent, but it's
 188  * safe to assume there cannot really be max int references).
 189  *
 190  * NOTE: The 0 test alone will not catch double zfreeing of ipc_port
 191  * structs, because the io_references field is the first word of the struct,
 192  * and zfree modifies that to point to the next free zone element.
 193  */
 194 #define IO_MAX_REFERENCES                                               \
 195         (unsigned)(~0 ^ (1 << (sizeof(int)*BYTE_SIZE - 1)))
 196
 197 #define io_reference(io)                                                \
 198 MACRO_BEGIN                                                             \
 199         assert((io)->io_references < IO_MAX_REFERENCES);                \
 200         (io)->io_references++;                                          \
 201 MACRO_END
 202
 203 #define io_release(io)                                                  \
 204 MACRO_BEGIN                                                             \
 205         assert((io)->io_references > 0 &&                               \
 206                     (io)->io_references <= IO_MAX_REFERENCES);          \
 207         (io)->io_references--;                                          \
 208 MACRO_END
 209
 210 /*
 211  * Exported interfaces
 212  */
 213
 214 /* Take a reference to an object */
 215 extern void ipc_object_reference(
 216         ipc_object_t    object);
 217
 218 /* Release a reference to an object */
 219 extern void ipc_object_release(
 220         ipc_object_t    object);
 221
 222 /* Look up an object in a space */
 223 extern kern_return_t ipc_object_translate(
 224         ipc_space_t             space,
 225         mach_port_name_t        name,
 226         mach_port_right_t       right,
 227         ipc_object_t            *objectp);
 228
 229 /* Look up two objects in a space, locking them in the order described */
 230 extern kern_return_t ipc_object_translate_two(
 231         ipc_space_t             space,
 232         mach_port_name_t        name1,
 233         mach_port_right_t       right1,
 234         ipc_object_t            *objectp1,
 235         mach_port_name_t        name2,
 236         mach_port_right_t       right2,
 237         ipc_object_t            *objectp2);
 238
 239 /* Allocate a dead-name entry */
 240 extern kern_return_t
 241 ipc_object_alloc_dead(
 242         ipc_space_t             space,
 243         mach_port_name_t        *namep);
 244
 245 /*  Allocate a dead-name entry, with a specific name */
 246 extern kern_return_t ipc_object_alloc_dead_name(
 247         ipc_space_t             space,
 248         mach_port_name_t        name);
 249
 250 /* Allocate an object */
 251 extern kern_return_t ipc_object_alloc(
 252         ipc_space_t             space,
 253         ipc_object_type_t       otype,
 254         mach_port_type_t        type,
 255         mach_port_urefs_t       urefs,
 256         mach_port_name_t        *namep,
 257         ipc_object_t            *objectp);
 258
 259 /* Allocate an object, with a specific name */
 260 extern kern_return_t ipc_object_alloc_name(
 261         ipc_space_t             space,
 262         ipc_object_type_t       otype,
 263         mach_port_type_t        type,
 264         mach_port_urefs_t       urefs,
 265         mach_port_name_t        name,
 266         ipc_object_t            *objectp);
 267
 268 /* Convert a send type name to a received type name */
 269 extern mach_msg_type_name_t ipc_object_copyin_type(
 270         mach_msg_type_name_t    msgt_name);
 271
 272 /* Copyin a capability from a space */
 273 extern kern_return_t ipc_object_copyin(
 274         ipc_space_t             space,
 275         mach_port_name_t        name,
 276         mach_msg_type_name_t    msgt_name,
 277         ipc_object_t            *objectp);
 278
 279 /* Copyin a naked capability from the kernel */
 280 extern void ipc_object_copyin_from_kernel(
 281         ipc_object_t            object,
 282         mach_msg_type_name_t    msgt_name);
 283
 284 /* Destroy a naked capability */
 285 extern void ipc_object_destroy(
 286         ipc_object_t            object,
 287         mach_msg_type_name_t    msgt_name);
 288
 289 /* Copyout a capability, placing it into a space */
 290 extern kern_return_t ipc_object_copyout(
 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        *namep);
 296
 297 /* Copyout a capability with a name, placing it into a space */
 298 extern kern_return_t ipc_object_copyout_name(
 299         ipc_space_t             space,
 300         ipc_object_t            object,
 301         mach_msg_type_name_t    msgt_name,
 302         boolean_t               overflow,
 303         mach_port_name_t        name);
 304
 305 /* Translate/consume the destination right of a message */
 306 extern void ipc_object_copyout_dest(
 307         ipc_space_t             space,
 308         ipc_object_t            object,
 309         mach_msg_type_name_t    msgt_name,
 310         mach_port_name_t        *namep);
 311
 312 /* Rename an entry in a space */
 313 extern kern_return_t ipc_object_rename(
 314         ipc_space_t             space,
 315         mach_port_name_t        oname,
 316         mach_port_name_t        nname);
 317
 318 #if     MACH_KDB
 319 /* Pretty-print an ipc object */
 320
 321 extern void ipc_object_print(
 322         ipc_object_t    object);
 323
 324 #endif  /* MACH_KDB */
 325
 326 #endif  /* _IPC_IPC_OBJECT_H_ */