bsd/sys/spawn_internal.h

   1 /*
   2  * Copyright (c) 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
  30 /*
  31  * [SPN] Support for _POSIX_SPAWN
  32  *
  33  * This file contains intern datastructures which are externally represented
  34  * as opaque void pointers to prevent introspection.  This permits us to
  35  * change the underlying implementation of the code to maintain it or to
  36  * support new features, as needed, without the consumer needing to recompile
  37  * their code because of structure size changes or data reorganization.
  38  */
  39
  40 #ifndef _SYS_SPAWN_INTERNAL_H_
  41 #define _SYS_SPAWN__INTERNALH_
  42
  43 #include <sys/_types.h>         /* __offsetof(), __darwin_size_t */
  44 #include <sys/syslimits.h>      /* PATH_MAX */
  45 #include <sys/spawn.h>
  46 #include <mach/machine.h>
  47 #include <mach/port.h>
  48 #include <mach/exception_types.h>
  49
  50 /*
  51  * Allowable posix_spawn() port action types
  52  */
  53 typedef enum {
  54         PSPA_SPECIAL = 0,
  55         PSPA_EXCEPTION = 1,
  56 } pspa_t;
  57
  58 /*
  59  * Internal representation of one port to be set on posix_spawn().
  60  * Currently this is limited to setting special and exception ports,
  61  * but could be extended to other inheritable port types.
  62  */
  63 typedef struct _ps_port_action {
  64         pspa_t                  port_type;
  65         exception_mask_t        mask;
  66         mach_port_t             new_port;
  67         exception_behavior_t    behavior;
  68         thread_state_flavor_t   flavor;
  69         int                     which;
  70 } _ps_port_action_t;
  71
  72 /*
  73  * A collection of port actions to take on the newly spawned process.
  74  */
  75 typedef struct _posix_spawn_port_actions {
  76         int                     pspa_alloc;
  77         int                     pspa_count;
  78         _ps_port_action_t       pspa_actions[];
  79 } *_posix_spawn_port_actions_t;
  80
  81 /*
  82  * Returns size in bytes of a _posix_spawn_port_actions holding x elements.
  83  */
  84 #define PS_PORT_ACTIONS_SIZE(x) \
  85         __offsetof(struct _posix_spawn_port_actions, pspa_actions[(x)])
  86
  87 #define NBINPREFS       4
  88
  89 /*
  90  * A posix_spawnattr structure contains all of the attribute elements that
  91  * can be set, as well as any metadata whose validity is signalled by the
  92  * presence of a bit in the flags field.  All fields are initialized to the
  93  * appropriate default values by posix_spawnattr_init().
  94  */
  95 typedef struct _posix_spawnattr {
  96         short           psa_flags;              /* spawn attribute flags */
  97         sigset_t        psa_sigdefault;         /* signal set to default */
  98         sigset_t        psa_sigmask;            /* signal set to mask */
  99         pid_t           psa_pgroup;             /* pgroup to spawn into */
 100         cpu_type_t      psa_binprefs[NBINPREFS];   /* cpu affinity prefs*/
 101         _posix_spawn_port_actions_t     psa_ports; /* special/exception ports */
 102 } *_posix_spawnattr_t;
 103
 104
 105 /*
 106  * Allowable posix_spawn() file actions
 107  */
 108 typedef enum {
 109         PSFA_OPEN = 0,
 110         PSFA_CLOSE = 1,
 111         PSFA_DUP2 = 2
 112 } psfa_t;
 113
 114
 115 /*
 116  * A posix_spawn() file action record for a single action
 117  *
 118  * Notes:       We carry around the full open arguments for both the open
 119  *              and the close to permit the use of a single array of action
 120  *              elements to be associated with a file actions object.
 121  *
 122  *              A possible future optimization would be to break this into
 123  *              a variable sized vector list to save space (i.e. a separate
 124  *              string area, allocation of least amount of path buffer per
 125  *              open action, etc.).
 126  *
 127  * XXX:         Currently overloading psfao_oflag for PSFA_DUP2
 128  */
 129 typedef struct _psfa_action {
 130         psfa_t  psfaa_type;                     /* file action type */
 131         int     psfaa_filedes;                  /* fd to operate on */
 132         struct _psfaa_open {
 133                 int     psfao_oflag;            /* open flags to use */
 134                 mode_t  psfao_mode;             /* mode for open */
 135                 char    psfao_path[PATH_MAX];   /* path to open */
 136         } psfaa_openargs;
 137 } _psfa_action_t;
 138
 139
 140 /*
 141  * Internal representation of posix_spawn() file actions structure
 142  *
 143  * Notes:       This is implemented as a structure followed by an array of
 144  *              file action records.  The psfa_act_alloc value is the number
 145  *              of elements allocated in this array, and the psfa_act_count is
 146  *              the number of elements currently in use (to permit some form
 147  *              of preallocation, e.g. a power of 2 growth for reallocation,
 148  *              etc.).
 149  *
 150  *              A possible future optimization would keep a size value and
 151  *              a structure base reference pointer to permit copyin to the
 152  *              kernel directly as a single blob, without damaging relative
 153  *              internal pointer math.  It's probably better that this be a
 154  *              long long rather than a true pointer, to make it invariant
 155  *              for 32 vs. 64 bt programming SPIs.
 156  */
 157 typedef struct _posix_spawn_file_actions {
 158         int             psfa_act_alloc;         /* available actions space */
 159         int             psfa_act_count;         /* count of defined actions */
 160         _psfa_action_t  psfa_act_acts[];        /* actions array (uses c99) */
 161 } *_posix_spawn_file_actions_t;
 162
 163 /*
 164  * Calculate the size of a structure, given the number of elements that it is
 165  * capable of containing.
 166  */
 167 #define PSF_ACTIONS_SIZE(x)     \
 168         __offsetof(struct _posix_spawn_file_actions, psfa_act_acts[(x)])
 169
 170 /*
 171  * Initial count of actions in a struct _posix_spawn_file_actions after it is
 172  * first allocated; this should be non-zero, since we expect that one would not
 173  * have been allocated unless there was an intent to use it.
 174  */
 175 #define PSF_ACTIONS_INIT_COUNT  2
 176
 177 /*
 178  * Structure defining the true third argument to the posix_spawn() system call
 179  * entry point; we wrap it and pass a descriptor so that we can know the
 180  * copyin size ahead of time, and deal with copying in variant lists of things
 181  * as single monolithic units, instead of many individual elements.  This is a
 182  * performance optimization.
 183  */
 184 struct _posix_spawn_args_desc {
 185         __darwin_size_t         attr_size;      /* size of attributes block */
 186         _posix_spawnattr_t      attrp;          /* pointer to block */
 187         __darwin_size_t file_actions_size;      /* size of file actions block */
 188         _posix_spawn_file_actions_t
 189                                 file_actions;   /* pointer to block */
 190         __darwin_size_t port_actions_size; /* size of port actions block */
 191         _posix_spawn_port_actions_t
 192                                 port_actions;   /* pointer to port block */
 193 };
 194
 195 #ifdef KERNEL
 196 #include <sys/appleapiopts.h>
 197 #ifdef __APPLE_API_PRIVATE
 198
 199 #if __DARWIN_ALIGN_NATURAL
 200 #pragma options align=natural
 201 #endif
 202
 203 struct user__posix_spawn_args_desc {
 204         user_size_t             attr_size;      /* size of attributes block */
 205         user_addr_t             attrp;          /* pointer to block */
 206         user_size_t     file_actions_size;      /* size of file actions block */
 207         user_addr_t             file_actions;   /* pointer to block */
 208         user_size_t     port_actions_size;      /* size of port actions block */
 209         user_addr_t             port_actions;   /* pointer to block */
 210 };
 211
 212
 213 #if __DARWIN_ALIGN_NATURAL
 214 #pragma options align=reset
 215 #endif
 216
 217 #endif  /* __APPLE_API_PRIVATE */
 218 #endif  /* KERNEL */
 219
 220 #endif  /* _SYS_SPAWN_INTERNAL_H_ */