threads/lu_utils.c

   1 /*
   2  * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Port and memory management for doing lookups to the lookup server
  27  * Copyright (C) 1989 by NeXT, Inc.
  28  */
  29 /*
  30  * HISTORY
  31  * 27-Mar-90  Gregg Kellogg (gk) at NeXT
  32  *      Changed to use bootstrap port instead of service port.
  33  *
  34  */
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <sys/types.h>
  38 #include <unistd.h>
  39 #include <mach/mach.h>
  40 #include <mach/error.h>
  41 #include <servers/bootstrap.h>
  42
  43 mach_port_t _lu_port = MACH_PORT_NULL;
  44 static name_t LOOKUP_NAME = "lookup daemon v2";
  45
  46 mach_port_t _lookupd_port(mach_port_t port) {
  47         if (port != MACH_PORT_NULL) {
  48                 kern_return_t ret;
  49                 mach_port_t bp;
  50                 ret = task_get_bootstrap_port(mach_task_self(), &bp);
  51                 if (ret != KERN_SUCCESS) {
  52                         mach_error("task_get_bootstrap_port() failed", ret);
  53                         abort();
  54                 }
  55                 if (bp == MACH_PORT_NULL) {
  56                         mach_error("task_get_bootstrap_port() returned MACH_PORT_NULL!", 0);
  57                         return MACH_PORT_NULL;
  58                 }
  59                 ret = bootstrap_register(bp, LOOKUP_NAME, port);
  60                 if (ret != BOOTSTRAP_SUCCESS) {
  61                         mach_error("bootstrap_register() failed", ret);
  62                         abort();
  63                 }
  64                 return port;
  65         }
  66         return _lu_port;
  67 }
  68
  69 /* called as child starts up.  mach ports aren't inherited: trash cache */
  70 void
  71 _lu_fork_child()
  72 {
  73         mach_port_t bp;
  74         kern_return_t ret;
  75         int pid = getpid();
  76
  77         _lu_port = MACH_PORT_NULL;
  78         if (pid > 2) {
  79                 ret = task_get_bootstrap_port(mach_task_self(), &bp);
  80                 if (ret != KERN_SUCCESS) {
  81                         mach_error("task_get_bootstrap_port() failed", ret);
  82                         abort();
  83                 }
  84                 if (bp == MACH_PORT_NULL) {
  85                         fprintf(stderr, "task_get_bootstrap_port() returned MACH_PORT_NULL!\n");
  86                         return;
  87                 }
  88                 ret = bootstrap_look_up(bp, LOOKUP_NAME, &_lu_port);
  89                 if (ret != BOOTSTRAP_SUCCESS && ret != BOOTSTRAP_UNKNOWN_SERVICE) {
  90                         mach_error("bootstrap_look_up() failed", ret);
  91                         _lu_port = MACH_PORT_NULL;
  92                 }
  93         }
  94 }
  95
  96 void
  97 _lu_setport(mach_port_t desired)
  98 {
  99         if (_lu_port != MACH_PORT_NULL) {
 100                 mach_port_deallocate(mach_task_self(), _lu_port);
 101         }
 102         _lu_port = desired;
 103 }
 104
 105 static int
 106 port_valid(mach_port_t port)
 107 {
 108         mach_port_type_t ptype;
 109         kern_return_t ret;
 110
 111         ret = mach_port_type(mach_task_self(), port, &ptype);
 112         if (ret != KERN_SUCCESS) {
 113                 mach_error("mach_port_type() failed", ret);
 114                 return 0;
 115         }
 116         return 1;
 117 }
 118
 119 int
 120 _lu_running(void)
 121 {
 122         if (_lu_port == MACH_PORT_NULL) {
 123                 _lu_fork_child();
 124         }
 125         if (_lu_port != MACH_PORT_NULL) {
 126                 if (port_valid(_lu_port)) {
 127                         return (1);
 128                 }
 129                 _lu_fork_child();
 130                 if (port_valid(_lu_port)) {
 131                         return (1);
 132                 }
 133         }
 134         return 0;
 135 }
 136