threads/lu_utils.c

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