mDNSPosix/Client.c

   1 /*
   2  * Copyright (c) 2002-2003 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     Change History (most recent first):
  24
  25 $Log: Client.c,v $
  26 Revision 1.9  2003/08/14 02:19:55  cheshire
  27 <rdar://problem/3375491> Split generic ResourceRecord type into two separate types: AuthRecord and CacheRecord
  28
  29 Revision 1.8  2003/08/12 19:56:26  cheshire
  30 Update to APSL 2.0
  31
  32 Revision 1.7  2003/07/02 21:19:58  cheshire
  33 <rdar://problem/3313413> Update copyright notices, etc., in source code comments
  34
  35 Revision 1.6  2003/06/18 05:48:41  cheshire
  36 Fix warnings
  37
  38 Revision 1.5  2003/05/06 00:00:50  cheshire
  39 <rdar://problem/3248914> Rationalize naming of domainname manipulation functions
  40
  41 Revision 1.4  2002/12/23 22:13:31  jgraessl
  42
  43 Reviewed by: Stuart Cheshire
  44 Initial IPv6 support for mDNSResponder.
  45
  46 Revision 1.3  2002/09/21 20:44:53  zarzycki
  47 Added APSL info
  48
  49 Revision 1.2  2002/09/19 04:20:44  cheshire
  50 Remove high-ascii characters that confuse some systems
  51
  52 Revision 1.1  2002/09/17 06:24:35  cheshire
  53 First checkin
  54
  55 */
  56
  57 #include <assert.h>
  58 #include <signal.h>
  59 #include <stdio.h>
  60 #include <string.h>
  61 #include <unistd.h>
  62 #include <stdlib.h>
  63
  64 #include "mDNSClientAPI.h"// Defines the interface to the mDNS core code
  65 #include "mDNSPosix.h"    // Defines the specific types needed to run mDNS on this platform
  66 #include "ExampleClientApp.h"
  67
  68 // Globals
  69 static mDNS mDNSStorage;       // mDNS core uses this to store its globals
  70 static mDNS_PlatformSupport PlatformStorage;  // Stores this platform's globals
  71 #define RR_CACHE_SIZE 500
  72 static CacheRecord gRRCache[RR_CACHE_SIZE];
  73
  74 static const char *gProgramName = "mDNSResponderPosix";
  75
  76 static void BrowseCallback(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, mDNSBool AddRecord)
  77     // A callback from the core mDNS code that indicates that we've received a
  78     // response to our query.  Note that this code runs on the main thread
  79     // (in fact, there is only one thread!), so we can safely printf the results.
  80 {
  81     domainlabel name;
  82     domainname  type;
  83     domainname  domain;
  84     char nameC[256];
  85     char typeC[256];
  86     char domainC[256];
  87     const char *state;
  88
  89         (void)m;                // Unused
  90         (void)question; // Unused
  91
  92     assert(answer->rrtype == kDNSType_PTR);
  93
  94     DeconstructServiceName(&answer->rdata->u.name, &name, &type, &domain);
  95
  96     ConvertDomainLabelToCString_unescaped(&name, nameC);
  97     ConvertDomainNameToCString(&type, typeC);
  98     ConvertDomainNameToCString(&domain, domainC);
  99
 100     // If the TTL has hit 0, the service is no longer available.
 101     if (!AddRecord) {
 102         state = "Lost ";
 103     } else {
 104         state = "Found";
 105     }
 106     fprintf(stderr, "*** %s name = '%s', type = '%s', domain = '%s'\n", state, nameC, typeC, domainC);
 107 }
 108
 109 static mDNSBool CheckThatServiceTypeIsUsable(const char *serviceType, mDNSBool printExplanation)
 110     // Checks that serviceType is a reasonable service type
 111     // label and, if it isn't and printExplanation is true, prints
 112     // an explanation of why not.
 113 {
 114     mDNSBool result;
 115
 116     result = mDNStrue;
 117     if (result && strlen(serviceType) > 63) {
 118         if (printExplanation) {
 119             fprintf(stderr,
 120                     "%s: Service type specified by -t is too long (must be 63 characters or less)\n",
 121                     gProgramName);
 122         }
 123         result = mDNSfalse;
 124     }
 125     if (result && serviceType[0] == 0) {
 126         if (printExplanation) {
 127             fprintf(stderr,
 128                     "%s: Service type specified by -t can't be empty\n",
 129                     gProgramName);
 130         }
 131         result = mDNSfalse;
 132     }
 133     return result;
 134 }
 135
 136 static const char kDefaultServiceType[] = "_afpovertcp._tcp.";
 137
 138 static void PrintUsage()
 139 {
 140     fprintf(stderr,
 141             "Usage: %s [-v level] [-t type]\n",
 142             gProgramName);
 143     fprintf(stderr, "          -v verbose mode, level is a number from 0 to 2\n");
 144     fprintf(stderr, "             0 = no debugging info (default)\n");
 145     fprintf(stderr, "             1 = standard debugging info\n");
 146     fprintf(stderr, "             2 = intense debugging info\n");
 147     fprintf(stderr, "          -t uses 'type' as the service type (default is '%s')\n", kDefaultServiceType);
 148 }
 149
 150 static const char *gServiceType      = kDefaultServiceType;
 151
 152 static void ParseArguments(int argc, char **argv)
 153     // Parses our command line arguments into the global variables
 154     // listed above.
 155 {
 156     int ch;
 157
 158     // Set gProgramName to the last path component of argv[0]
 159
 160     gProgramName = strrchr(argv[0], '/');
 161     if (gProgramName == NULL) {
 162         gProgramName = argv[0];
 163     } else {
 164         gProgramName += 1;
 165     }
 166
 167     // Parse command line options using getopt.
 168
 169     do {
 170         ch = getopt(argc, argv, "v:t:");
 171         if (ch != -1) {
 172             switch (ch) {
 173                 case 'v':
 174                     gMDNSPlatformPosixVerboseLevel = atoi(optarg);
 175                     if (gMDNSPlatformPosixVerboseLevel < 0 || gMDNSPlatformPosixVerboseLevel > 2) {
 176                         fprintf(stderr,
 177                                 "%s: Verbose mode must be in the range 0..2\n",
 178                                 gProgramName);
 179                         exit(1);
 180                     }
 181                     break;
 182                 case 't':
 183                     gServiceType = optarg;
 184                     if ( ! CheckThatServiceTypeIsUsable(gServiceType, mDNStrue) ) {
 185                         exit(1);
 186                     }
 187                     break;
 188                 case '?':
 189                 default:
 190                     PrintUsage();
 191                     exit(1);
 192                     break;
 193             }
 194         }
 195     } while (ch != -1);
 196
 197     // Check for any left over command line arguments.
 198
 199     if (optind != argc) {
 200         fprintf(stderr, "%s: Unexpected argument '%s'\n", gProgramName, argv[optind]);
 201         exit(1);
 202     }
 203 }
 204
 205 int main(int argc, char **argv)
 206     // The program's main entry point.  The program does a trivial
 207     // mDNS query, looking for all AFP servers in the local domain.
 208 {
 209     int     result;
 210     mStatus     status;
 211     DNSQuestion question;
 212     domainname  type;
 213     domainname  domain;
 214
 215     // Parse our command line arguments.  This won't come back if there's an error.
 216     ParseArguments(argc, argv);
 217
 218     // Initialise the mDNS core.
 219         status = mDNS_Init(&mDNSStorage, &PlatformStorage,
 220         gRRCache, RR_CACHE_SIZE,
 221         mDNS_Init_DontAdvertiseLocalAddresses,
 222         mDNS_Init_NoInitCallback, mDNS_Init_NoInitCallbackContext);
 223     if (status == mStatus_NoError) {
 224
 225         // Construct and start the query.
 226
 227         MakeDomainNameFromDNSNameString(&type, gServiceType);
 228         MakeDomainNameFromDNSNameString(&domain, "local.");
 229
 230         status = mDNS_StartBrowse(&mDNSStorage, &question, &type, &domain, mDNSInterface_Any, BrowseCallback, NULL);
 231
 232         // Run the platform main event loop until the user types ^C.
 233         // The BrowseCallback routine is responsible for printing
 234         // any results that we find.
 235
 236         if (status == mStatus_NoError) {
 237             fprintf(stderr, "Hit ^C when you're bored waiting for responses.\n");
 238                 ExampleClientEventLoop(&mDNSStorage);
 239             mDNS_StopQuery(&mDNSStorage, &question);
 240                         mDNS_Close(&mDNSStorage);
 241         }
 242     }
 243
 244     if (status == mStatus_NoError) {
 245         result = 0;
 246     } else {
 247         result = 2;
 248     }
 249     if ( (result != 0) || (gMDNSPlatformPosixVerboseLevel > 0) ) {
 250         fprintf(stderr, "%s: Finished with status %ld, result %d\n", gProgramName, status, result);
 251     }
 252
 253     return 0;
 254 }