osfmk/mach/port.h

   1 /*
   2  * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990,1989,1988,1987 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  * NOTICE: This file was modified by McAfee Research in 2004 to introduce
  58  * support for mandatory and extensible security protections.  This notice
  59  * is included in support of clause 2.2 (b) of the Apple Public License,
  60  * Version 2.0.
  61  */
  62 /*
  63  */
  64 /*
  65  *      File:   mach/port.h
  66  *
  67  *      Definition of a Mach port
  68  *
  69  *      Mach ports are the endpoints to Mach-implemented communications
  70  *      channels (usually uni-directional message queues, but other types
  71  *      also exist).
  72  *
  73  *      Unique collections of these endpoints are maintained for each
  74  *      Mach task.  Each Mach port in the task's collection is given a
  75  *      [task-local] name to identify it - and the the various "rights"
  76  *      held by the task for that specific endpoint.
  77  *
  78  *      This header defines the types used to identify these Mach ports
  79  *      and the various rights associated with them.  For more info see:
  80  *
  81  *      <mach/mach_port.h> - manipulation of port rights in a given space
  82  *      <mach/message.h> - message queue [and port right passing] mechanism
  83  *
  84  */
  85
  86 #ifndef _MACH_PORT_H_
  87 #define _MACH_PORT_H_
  88
  89 #include <sys/cdefs.h>
  90 #include <stdint.h>
  91 #include <mach/boolean.h>
  92 #include <mach/machine/vm_types.h>
  93
  94 /*
  95  *      mach_port_name_t - the local identity for a Mach port
  96  *
  97  *      The name is Mach port namespace specific.  It is used to
  98  *      identify the rights held for that port by the task whose
  99  *      namespace is implied [or specifically provided].
 100  *
 101  *      Use of this type usually implies just a name - no rights.
 102  *      See mach_port_t for a type that implies a "named right."
 103  *
 104  */
 105
 106 typedef natural_t mach_port_name_t;
 107 typedef mach_port_name_t *mach_port_name_array_t;
 108
 109 #ifdef  KERNEL
 110
 111 /*
 112  *      mach_port_t - a named port right
 113  *
 114  *      In the kernel, "rights" are represented [named] by pointers to
 115  *      the ipc port object in question. There is no port namespace for the
 116  *      rights to be collected.
 117  *
 118  *      Actually, there is namespace for the kernel task.  But most kernel
 119  *      code - including, but not limited to, Mach IPC code - lives in the
 120  *      limbo between the current user-level task and the "next" task. Very
 121  *      little of the kernel code runs in full kernel task context.  So very
 122  *      little of it gets to use the kernel task's port name space.
 123  *
 124  *      Because of this implementation approach, all in-kernel rights for
 125  *      a given port coalesce [have the same name/pointer].  The actual
 126  *      references are counted in the port itself.  It is up to the kernel
 127  *      code in question to "just remember" how many [and what type of]
 128  *      rights it holds and handle them appropriately.
 129  *
 130  */
 131
 132 #ifndef MACH_KERNEL_PRIVATE
 133 /*
 134  *      For kernel code that resides outside of Mach proper, we opaque the
 135  *      port structure definition.
 136  */
 137 struct ipc_port ;
 138
 139 #endif  /* MACH_KERNEL_PRIVATE */
 140
 141 typedef struct ipc_port         *ipc_port_t;
 142
 143 #define IPC_PORT_NULL           ((ipc_port_t) 0UL)
 144 #define IPC_PORT_DEAD           ((ipc_port_t)~0UL)
 145 #define IPC_PORT_VALID(port) \
 146         ((port) != IPC_PORT_NULL && (port) != IPC_PORT_DEAD)
 147
 148 typedef ipc_port_t              mach_port_t;
 149
 150 /*
 151  * Since the 32-bit and 64-bit representations of ~0 are different,
 152  * explicitly handle MACH_PORT_DEAD
 153  */
 154
 155 #define CAST_MACH_PORT_TO_NAME(x) ((mach_port_name_t)(uintptr_t)(x))
 156 #define CAST_MACH_NAME_TO_PORT(x) ((x) == MACH_PORT_DEAD ? (mach_port_t)IPC_PORT_DEAD : (mach_port_t)(uintptr_t)(x))
 157
 158 #else   /* KERNEL */
 159
 160 /*
 161  *      mach_port_t - a named port right
 162  *
 163  *      In user-space, "rights" are represented by the name of the
 164  *      right in the Mach port namespace.  Even so, this type is
 165  *      presented as a unique one to more clearly denote the presence
 166  *      of a right coming along with the name.
 167  *
 168  *      Often, various rights for a port held in a single name space
 169  *      will coalesce and are, therefore, be identified by a single name
 170  *      [this is the case for send and receive rights].  But not
 171  *      always [send-once rights currently get a unique name for
 172  *      each right].
 173  *
 174  */
 175
 176 #ifndef _MACH_PORT_T
 177 #define _MACH_PORT_T
 178 typedef mach_port_name_t                mach_port_t;
 179 #endif
 180
 181 #endif  /* KERNEL */
 182
 183 typedef mach_port_t                     *mach_port_array_t;
 184
 185 /*
 186  *  MACH_PORT_NULL is a legal value that can be carried in messages.
 187  *  It indicates the absence of any port or port rights.  (A port
 188  *  argument keeps the message from being "simple", even if the
 189  *  value is MACH_PORT_NULL.)  The value MACH_PORT_DEAD is also a legal
 190  *  value that can be carried in messages.  It indicates
 191  *  that a port right was present, but it died.
 192  */
 193
 194 #define MACH_PORT_NULL          0  /* intentional loose typing */
 195 #define MACH_PORT_DEAD          ((mach_port_name_t) ~0)
 196 #define MACH_PORT_VALID(name)                           \
 197                 (((name) != MACH_PORT_NULL) &&          \
 198                  ((name) != MACH_PORT_DEAD))
 199
 200
 201 /*
 202  *      For kernel-selected [assigned] port names, the name is
 203  *      comprised of two parts: a generation number and an index.
 204  *      This approach keeps the exact same name from being generated
 205  *      and reused too quickly [to catch right/reference counting bugs].
 206  *      The dividing line between the constituent parts is exposed so
 207  *      that efficient "mach_port_name_t to data structure pointer"
 208  *      conversion implementation can be made.  But it is possible
 209  *      for user-level code to assign their own names to Mach ports.
 210  *      These are not required to participate in this algorithm.  So
 211  *      care should be taken before "assuming" this model.
 212  *
 213  */
 214
 215 #ifndef NO_PORT_GEN
 216
 217 #define MACH_PORT_INDEX(name)           ((name) >> 8)
 218 #define MACH_PORT_GEN(name)             (((name) & 0xff) << 24)
 219 #define MACH_PORT_MAKE(index, gen)      \
 220                 (((index) << 8) | (gen) >> 24)
 221
 222 #else   /* NO_PORT_GEN */
 223
 224 #define MACH_PORT_INDEX(name)           (name)
 225 #define MACH_PORT_GEN(name)             (0)
 226 #define MACH_PORT_MAKE(index, gen)      (index)
 227
 228 #endif  /* NO_PORT_GEN */
 229
 230
 231 /*
 232  *  These are the different rights a task may have for a port.
 233  *  The MACH_PORT_RIGHT_* definitions are used as arguments
 234  *  to mach_port_allocate, mach_port_get_refs, etc, to specify
 235  *  a particular right to act upon.  The mach_port_names and
 236  *  mach_port_type calls return bitmasks using the MACH_PORT_TYPE_*
 237  *  definitions.  This is because a single name may denote
 238  *  multiple rights.
 239  */
 240
 241 typedef natural_t mach_port_right_t;
 242
 243 #define MACH_PORT_RIGHT_SEND            ((mach_port_right_t) 0)
 244 #define MACH_PORT_RIGHT_RECEIVE         ((mach_port_right_t) 1)
 245 #define MACH_PORT_RIGHT_SEND_ONCE       ((mach_port_right_t) 2)
 246 #define MACH_PORT_RIGHT_PORT_SET        ((mach_port_right_t) 3)
 247 #define MACH_PORT_RIGHT_DEAD_NAME       ((mach_port_right_t) 4)
 248 #define MACH_PORT_RIGHT_LABELH          ((mach_port_right_t) 5)
 249 #define MACH_PORT_RIGHT_NUMBER          ((mach_port_right_t) 6)
 250
 251 typedef natural_t mach_port_type_t;
 252 typedef mach_port_type_t *mach_port_type_array_t;
 253
 254 #define MACH_PORT_TYPE(right)                                           \
 255                 ((mach_port_type_t)(((mach_port_type_t) 1)              \
 256                 << ((right) + ((mach_port_right_t) 16))))
 257 #define MACH_PORT_TYPE_NONE         ((mach_port_type_t) 0L)
 258 #define MACH_PORT_TYPE_SEND         MACH_PORT_TYPE(MACH_PORT_RIGHT_SEND)
 259 #define MACH_PORT_TYPE_RECEIVE      MACH_PORT_TYPE(MACH_PORT_RIGHT_RECEIVE)
 260 #define MACH_PORT_TYPE_SEND_ONCE    MACH_PORT_TYPE(MACH_PORT_RIGHT_SEND_ONCE)
 261 #define MACH_PORT_TYPE_PORT_SET     MACH_PORT_TYPE(MACH_PORT_RIGHT_PORT_SET)
 262 #define MACH_PORT_TYPE_DEAD_NAME    MACH_PORT_TYPE(MACH_PORT_RIGHT_DEAD_NAME)
 263 #define MACH_PORT_TYPE_LABELH       MACH_PORT_TYPE(MACH_PORT_RIGHT_LABELH)
 264
 265 /* Convenient combinations. */
 266
 267 #define MACH_PORT_TYPE_SEND_RECEIVE                                     \
 268                 (MACH_PORT_TYPE_SEND|MACH_PORT_TYPE_RECEIVE)
 269 #define MACH_PORT_TYPE_SEND_RIGHTS                                      \
 270                 (MACH_PORT_TYPE_SEND|MACH_PORT_TYPE_SEND_ONCE)
 271 #define MACH_PORT_TYPE_PORT_RIGHTS                                      \
 272                 (MACH_PORT_TYPE_SEND_RIGHTS|MACH_PORT_TYPE_RECEIVE)
 273 #define MACH_PORT_TYPE_PORT_OR_DEAD                                     \
 274                 (MACH_PORT_TYPE_PORT_RIGHTS|MACH_PORT_TYPE_DEAD_NAME)
 275 #define MACH_PORT_TYPE_ALL_RIGHTS                                       \
 276                 (MACH_PORT_TYPE_PORT_OR_DEAD|MACH_PORT_TYPE_PORT_SET)
 277
 278 /* Dummy type bits that mach_port_type/mach_port_names can return. */
 279
 280 #define MACH_PORT_TYPE_DNREQUEST        0x80000000
 281
 282 /* User-references for capabilities. */
 283
 284 typedef natural_t mach_port_urefs_t;
 285 typedef integer_t mach_port_delta_t;                    /* change in urefs */
 286
 287 /* Attributes of ports.  (See mach_port_get_receive_status.) */
 288
 289 typedef natural_t mach_port_seqno_t;            /* sequence number */
 290 typedef natural_t mach_port_mscount_t;          /* make-send count */
 291 typedef natural_t mach_port_msgcount_t;         /* number of msgs */
 292 typedef natural_t mach_port_rights_t;           /* number of rights */
 293
 294 /*
 295  *      Are there outstanding send rights for a given port?
 296  */
 297 #define MACH_PORT_SRIGHTS_NONE          0               /* no srights */
 298 #define MACH_PORT_SRIGHTS_PRESENT       1               /* srights */
 299 typedef unsigned int mach_port_srights_t;       /* status of send rights */
 300
 301 typedef struct mach_port_status {
 302         mach_port_rights_t      mps_pset;       /* count of containing port sets */
 303         mach_port_seqno_t       mps_seqno;      /* sequence number */
 304         mach_port_mscount_t     mps_mscount;    /* make-send count */
 305         mach_port_msgcount_t    mps_qlimit;     /* queue limit */
 306         mach_port_msgcount_t    mps_msgcount;   /* number in the queue */
 307         mach_port_rights_t      mps_sorights;   /* how many send-once rights */
 308         boolean_t               mps_srights;    /* do send rights exist? */
 309         boolean_t               mps_pdrequest;  /* port-deleted requested? */
 310         boolean_t               mps_nsrequest;  /* no-senders requested? */
 311         natural_t               mps_flags;              /* port flags */
 312 } mach_port_status_t;
 313
 314 /* System-wide values for setting queue limits on a port */
 315 #define MACH_PORT_QLIMIT_ZERO           ((mach_port_msgcount_t) 0)
 316 #define MACH_PORT_QLIMIT_BASIC          ((mach_port_msgcount_t) 5)
 317 #define MACH_PORT_QLIMIT_SMALL          ((mach_port_msgcount_t) 16)
 318 #define MACH_PORT_QLIMIT_LARGE          ((mach_port_msgcount_t) 1024)
 319 #define MACH_PORT_QLIMIT_KERNEL         ((mach_port_msgcount_t) 65536)
 320 #define MACH_PORT_QLIMIT_MIN            MACH_PORT_QLIMIT_ZERO
 321 #define MACH_PORT_QLIMIT_DEFAULT        MACH_PORT_QLIMIT_BASIC
 322 #define MACH_PORT_QLIMIT_MAX            MACH_PORT_QLIMIT_LARGE
 323
 324 typedef struct mach_port_limits {
 325         mach_port_msgcount_t    mpl_qlimit;     /* number of msgs */
 326 } mach_port_limits_t;
 327
 328 typedef integer_t *mach_port_info_t;            /* varying array of natural_t */
 329
 330 /* Flavors for mach_port_get/set_attributes() */
 331 typedef int     mach_port_flavor_t;
 332 #define MACH_PORT_LIMITS_INFO           1       /* uses mach_port_status_t */
 333 #define MACH_PORT_RECEIVE_STATUS        2       /* uses mach_port_limits_t */
 334 #define MACH_PORT_DNREQUESTS_SIZE       3       /* info is int */
 335
 336 #define MACH_PORT_LIMITS_INFO_COUNT     ((natural_t) \
 337         (sizeof(mach_port_limits_t)/sizeof(natural_t)))
 338 #define MACH_PORT_RECEIVE_STATUS_COUNT  ((natural_t) \
 339         (sizeof(mach_port_status_t)/sizeof(natural_t)))
 340 #define MACH_PORT_DNREQUESTS_SIZE_COUNT 1
 341
 342 /*
 343  * Structure used to pass information about port allocation requests.
 344  * Must be padded to 64-bits total length.
 345  */
 346 typedef struct mach_port_qos {
 347         unsigned int            name:1;         /* name given */
 348         unsigned int            prealloc:1;     /* prealloced message */
 349         boolean_t               pad1:30;
 350         natural_t               len;
 351 } mach_port_qos_t;
 352
 353 #if     !__DARWIN_UNIX03 && !defined(_NO_PORT_T_FROM_MACH)
 354 /*
 355  *  Mach 3.0 renamed everything to have mach_ in front of it.
 356  *  These types and macros are provided for backward compatibility
 357  *      but are deprecated.
 358  */
 359 typedef mach_port_t             port_t;
 360 typedef mach_port_name_t        port_name_t;
 361 typedef mach_port_name_t        *port_name_array_t;
 362
 363 #define PORT_NULL               ((port_t) 0)
 364 #define PORT_DEAD               ((port_t) ~0)
 365 #define PORT_VALID(name) \
 366                 ((port_t)(name) != PORT_NULL && (port_t)(name) != PORT_DEAD)
 367
 368 #endif  /* !__DARWIN_UNIX03 && !_NO_PORT_T_FROM_MACH */
 369
 370 #endif  /* _MACH_PORT_H_ */