Plugins/IPMonitor/serviceIDNumber.c

   1 /*
   2  * Copyright (c) 2019 Apple 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 /*
  25  * serviceID_number.c
  26  * - assigns numbers to serviceID strings
  27  */
  28
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <unistd.h>
  32
  33 #include "serviceIDNumber.h"
  34 #include <CoreFoundation/CFDictionary.h>
  35
  36 #if TEST_SERVICEID_NUMBER
  37 #include <SystemConfiguration/SCPrivate.h>
  38 #endif /* TEST_SERVICEID_NUMBER */
  39
  40
  41 /* dictionary to hold serviceIDNumber: key is the serviceID */
  42 static CFMutableDictionaryRef   S_serviceID_to_number_dict;
  43
  44 /* dictionary to hold serviceID: key is the serviceIDNumber */
  45 static CFMutableDictionaryRef   S_number_to_serviceID_dict;
  46
  47 static Boolean
  48 serviceIDNumberEqual(const void * ptr1, const void * ptr2)
  49 {
  50         return (((serviceIDNumber)ptr1) == ((serviceIDNumber)ptr2));
  51 }
  52
  53 static CFStringRef
  54 serviceIDNumberCopyDescription(const void * ptr)
  55 {
  56         return CFStringCreateWithFormat(NULL, NULL, CFSTR("%ld"),
  57                                         (serviceIDNumber)ptr);
  58 }
  59
  60 static CFHashCode
  61 serviceIDNumberHash(const void * ptr) {
  62         return (CFHashCode)((serviceIDNumber)ptr);
  63 }
  64
  65 static const CFDictionaryValueCallBacks kserviceIDNumberValueCallBacks = {
  66         0, NULL, NULL, serviceIDNumberCopyDescription, serviceIDNumberEqual
  67 };
  68
  69 static const CFDictionaryKeyCallBacks kserviceIDNumberKeyCallBacks = {
  70         0, NULL, NULL, serviceIDNumberCopyDescription, serviceIDNumberEqual,
  71         serviceIDNumberHash
  72 };
  73
  74 /**
  75  ** S_serviceID_numbers
  76  **/
  77
  78 __private_extern__ Boolean
  79 serviceIDNumberGetIfPresent(CFStringRef serviceID, serviceIDNumber *sidn)
  80 {
  81         Boolean                 has_number;
  82         const void *            val;
  83
  84         has_number = CFDictionaryGetValueIfPresent(S_serviceID_to_number_dict,
  85                                                    serviceID, &val);
  86         if (has_number) {
  87                 *sidn = (serviceIDNumber)val;
  88         }
  89         return (has_number);
  90 }
  91
  92 /*
  93  * Function: serviceIDNumberGet
  94  * Purpose:
  95  *   Return the currently assigned serviceIDNumber for the given serviceID.
  96  *   If one is already assigned, return that. If one isn't assigned, check
  97  *   the next integer value after 'current_sidn', but skip zero.
  98  *   If that number is assigned, pick the next one.
  99  */
 100 static serviceIDNumber  S_current_sidn;
 101
 102 __private_extern__ serviceIDNumber
 103 serviceIDNumberGet(CFStringRef serviceID)
 104 {
 105         serviceIDNumber         sidn;
 106
 107         if (serviceIDNumberGetIfPresent(serviceID, &sidn)) {
 108                 return (sidn);
 109         }
 110         while (1) {
 111                 /* assign a number to the serviceID */
 112                 S_current_sidn++;
 113                 if (S_current_sidn == kserviceIDNumberZero) {
 114                         /* skip zero */
 115                         S_current_sidn++;
 116                 }
 117                 /* if it's in use, skip to the next value */
 118                 if (CFDictionaryContainsKey(S_number_to_serviceID_dict,
 119                                             (const void *)S_current_sidn)) {
 120                         continue;
 121                 }
 122                 /* it's not in use, use it */
 123                 sidn = S_current_sidn;
 124                 CFDictionarySetValue(S_serviceID_to_number_dict,
 125                                      serviceID, (const void *)sidn);
 126                 CFDictionarySetValue(S_number_to_serviceID_dict,
 127                                      (const void *)sidn, serviceID);
 128                 break;
 129         }
 130         return (sidn);
 131 }
 132
 133
 134 __private_extern__ void
 135 serviceIDNumberRemove(CFStringRef serviceID)
 136 {
 137         const void *    val;
 138
 139         if (CFDictionaryGetValueIfPresent(S_serviceID_to_number_dict, serviceID,
 140                                           &val)) {
 141 #if TEST_SERVICEID_NUMBER
 142                 SCPrint(TRUE, stdout, CFSTR("Removing %@ %ld\n"),
 143                         serviceID, (serviceIDNumber)val);
 144 #endif
 145                 CFDictionaryRemoveValue(S_serviceID_to_number_dict, serviceID);
 146                 CFDictionaryRemoveValue(S_number_to_serviceID_dict, val);
 147         }
 148 }
 149
 150 __private_extern__ void
 151 serviceIDNumberInit(void)
 152 {
 153         S_serviceID_to_number_dict
 154                 = CFDictionaryCreateMutable(NULL, 0,
 155                                             &kCFTypeDictionaryKeyCallBacks,
 156                                             &kserviceIDNumberValueCallBacks);
 157         S_number_to_serviceID_dict
 158                 = CFDictionaryCreateMutable(NULL, 0,
 159                                             &kserviceIDNumberKeyCallBacks,
 160                                             &kCFTypeDictionaryValueCallBacks);
 161 }
 162
 163 #if TEST_SERVICEID_NUMBER
 164
 165 static CFStringRef
 166 my_CFUUIDStringCreate(CFAllocatorRef alloc)
 167 {
 168         CFUUIDRef       uuid;
 169         CFStringRef     uuid_str;
 170
 171         uuid = CFUUIDCreate(alloc);
 172         uuid_str = CFUUIDCreateString(alloc, uuid);
 173         CFRelease(uuid);
 174         return (uuid_str);
 175 }
 176
 177 int
 178 main()
 179 {
 180 #define N_LIST          10
 181         CFStringRef     serviceID_list[N_LIST];
 182
 183         serviceIDNumberInit();
 184         for (int i = 0; i < N_LIST; i++) {
 185                 CFStringRef     serviceID = my_CFUUIDStringCreate(NULL);
 186                 serviceIDNumber sidn;
 187
 188                 /* force a collision */
 189                 S_current_sidn = -1;
 190
 191                 sidn = serviceIDNumberGet(serviceID);
 192                 SCPrint(TRUE, stdout, CFSTR("%d: %@ %ld\n"),
 193                         i, serviceID, sidn);
 194                 serviceID_list[i] = serviceID;
 195
 196         }
 197         for (int i = 0; i < N_LIST; i++) {
 198                 CFStringRef     serviceID = serviceID_list[i];
 199                 serviceIDNumber sidn;
 200
 201                 if (!serviceIDNumberGetIfPresent(serviceID, &sidn)) {
 202                         SCPrint(TRUE, stderr, CFSTR("Failed to find %@\n"),
 203                                 serviceID);
 204                         exit(1);
 205                 }
 206                 SCPrint(TRUE, stdout, CFSTR("%@ => %ld\n"), serviceID, sidn);
 207         }
 208         {
 209                 serviceIDNumber sidn;
 210
 211                 if (serviceIDNumberGetIfPresent(CFSTR("blah"), &sidn)) {
 212                         fprintf(stderr,
 213                                 "Shouldn't have been able to look that up\n");
 214                         exit(1);
 215                 }
 216         }
 217
 218         for (int i = 0; i < N_LIST / 2; i++) {
 219                 CFStringRef     serviceID = serviceID_list[i];
 220                 serviceIDNumber sidn;
 221
 222                 serviceIDNumberRemove(serviceID);
 223                 if (serviceIDNumberGetIfPresent(serviceID, &sidn)) {
 224                         SCPrint(TRUE, stderr,
 225                                 CFSTR("Found %@, but shouldn't have\n"),
 226                                 serviceID);
 227                         exit(1);
 228                 }
 229         }
 230
 231         for (int i = 0; i < N_LIST; i++) {
 232                 CFStringRef     serviceID = serviceID_list[i];
 233                 serviceIDNumber sidn;
 234
 235                 sidn = serviceIDNumberGet(serviceID);
 236                 SCPrint(TRUE, stdout, CFSTR("%d: %@ %ld\n"),
 237                         i, serviceID, sidn);
 238         }
 239         exit(0);
 240 }
 241 #endif /* TEST_SERVICEID_NUMBER */