osfmk/ipc/ipc_object.h

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