mDNSMacOS9/Searcher.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: Searcher.c,v $
  26 Revision 1.2  2004/05/27 06:30:21  cheshire
  27 Add code to test DNSServiceQueryRecord()
  28
  29 Revision 1.1  2004/03/12 21:30:25  cheshire
  30 Build a System-Context Shared Library from mDNSCore, for the benefit of developers
  31 like Muse Research who want to be able to use mDNS/DNS-SD from GPL-licensed code.
  32
  33  */
  34
  35 #include <stdio.h>                                              // For printf()
  36 #include <string.h>                                             // For strcpy()
  37
  38 #include <Events.h>                                             // For WaitNextEvent()
  39 #include <CodeFragments.h>                              // For SIOkUnresolvedCFragSymbolAddress
  40
  41 #include <SIOUX.h>                                              // For SIOUXHandleOneEvent()
  42
  43 #include <OpenTransport.h>
  44 #include <OpenTptInternet.h>
  45
  46 #include "dns_sd.h"
  47
  48 #define ns_c_in 1
  49 #define ns_t_a 1
  50
  51 typedef union { UInt8 b[2]; UInt16 NotAnInteger; } mDNSOpaque16;
  52 static UInt16 mDNSVal16(mDNSOpaque16 x) { return((UInt16)(x.b[0]<<8 | x.b[1])); }
  53 static mDNSOpaque16 mDNSOpaque16fromIntVal(UInt16 v)
  54         { mDNSOpaque16 x; x.b[0] = (UInt8)(v >> 8); x.b[1] = (UInt8)(v & 0xFF); return(x); }
  55
  56 typedef struct
  57         {
  58         OTLIFO serviceinfolist;
  59         Boolean headerPrinted;
  60         Boolean lostRecords;
  61         } SearcherServices;
  62
  63 typedef struct
  64         {
  65         SearcherServices *services;
  66         char name[kDNSServiceMaxDomainName];
  67         char type[kDNSServiceMaxDomainName];
  68         char domn[kDNSServiceMaxDomainName];
  69         char host[kDNSServiceMaxDomainName];
  70         char text[kDNSServiceMaxDomainName];
  71         InetHost      address;
  72         mDNSOpaque16  notAnIntPort;
  73         DNSServiceRef sdRef;
  74         Boolean       add;
  75         Boolean       dom;
  76         OTLink        link;
  77         } linkedServiceInfo;
  78
  79 static SearcherServices services;
  80
  81 // PrintServiceInfo prints the service information to standard out
  82 // A real application might want to do something else with the information
  83 static void PrintServiceInfo(SearcherServices *services)
  84         {
  85         OTLink *link = OTReverseList(OTLIFOStealList(&services->serviceinfolist));
  86
  87         while (link)
  88                 {
  89                 linkedServiceInfo *s = OTGetLinkObject(link, linkedServiceInfo, link);
  90
  91                 if (!services->headerPrinted)
  92                         {
  93                         printf("%-55s Type             Domain         Target Host     IP Address      Port Info\n", "Name");
  94                         services->headerPrinted = true;
  95                         }
  96
  97                 if (s->dom)
  98                         {
  99                         if (s->add) printf("%-55s available for browsing\n", s->domn);
 100                         else        printf("%-55s no longer available for browsing\n", s->domn);
 101                         }
 102                 else
 103                         {
 104                         char ip[16];
 105                         unsigned char *p = (unsigned char *)&s->address;
 106                         sprintf(ip, "%d.%d.%d.%d", p[0], p[1], p[2], p[3]);
 107                         printf("%-55s %-16s %-14s ", s->name, s->type, s->domn);
 108                         if (s->add) printf("%-15s %-15s %5d %s\n", s->host, ip, mDNSVal16(s->notAnIntPort), s->text);
 109                         else        printf("Removed\n");
 110                         }
 111
 112                 link = link->fNext;
 113                 OTFreeMem(s);
 114                 }
 115         }
 116
 117 static void FoundInstanceAddress(DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode,
 118         const char *fullname, uint16_t rrtype, uint16_t rrclass, uint16_t rdlen, const void *rdata, uint32_t ttl, void *context)
 119         {
 120         linkedServiceInfo *info = (linkedServiceInfo *)context;
 121         SearcherServices *services = info->services;
 122         (void)sdRef;                    // Unused
 123         (void)interfaceIndex;   // Unused
 124         (void)fullname;                 // Unused
 125         (void)ttl;                              // Unused
 126         if (errorCode == kDNSServiceErr_NoError)
 127                 if (flags & kDNSServiceFlagsAdd)
 128                         if (rrclass == ns_c_in && rrtype == ns_t_a && rdlen == sizeof(info->address))
 129                                 {
 130                                 memcpy(&info->address, rdata, sizeof(info->address));
 131                                 DNSServiceRefDeallocate(info->sdRef);
 132                                 OTLIFOEnqueue(&services->serviceinfolist, &info->link);
 133                                 }
 134         }
 135
 136 static void FoundInstanceInfo(DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex,
 137         DNSServiceErrorType errorCode, const char *fullname, const char *hosttarget, uint16_t notAnIntPort,
 138         uint16_t txtLen, const char *txtRecord, void *context)
 139         {
 140         linkedServiceInfo *info = (linkedServiceInfo *)context;
 141         SearcherServices *services = info->services;
 142         (void)sdRef;                    // Unused
 143         (void)flags;                    // Unused
 144         (void)interfaceIndex;   // Unused
 145         (void)errorCode;                // Unused
 146         (void)fullname;                 // Unused
 147         strcpy(info->host, hosttarget);
 148         if (txtLen == 0) info->text[0] = 0;
 149         else
 150                 {
 151                 strncpy(info->text, txtRecord+1, txtRecord[0]);
 152                 info->text[txtRecord[0]] = 0;
 153                 }
 154         info->notAnIntPort.NotAnInteger = notAnIntPort;
 155         DNSServiceRefDeallocate(info->sdRef);
 156         DNSServiceQueryRecord(&info->sdRef, 0, 0, info->host, ns_t_a, ns_c_in, FoundInstanceAddress, info);
 157         }
 158
 159 // When a new named instance of a service is found, FoundInstance() is called.
 160 // In this sample code we turn around and immediately to a DNSServiceResolve() to resolve that service name
 161 // to find its target host, port, and txtinfo, but a normal browing application would just display the name.
 162 // Resolving every single thing you find can be quite hard on the network, so you shouldn't do this
 163 // in a real application. Defer resolving until the client has picked which instance from the
 164 // long list of services is the one they want to use, and then resolve only that one.
 165 static void FoundInstance(DNSServiceRef client, DNSServiceFlags flags, uint32_t interface, DNSServiceErrorType errorCode,
 166     const char *replyName, const char *replyType, const char *replyDomain, void *context)
 167         {
 168 #pragma unused(client, interface, errorCode)
 169         SearcherServices *services = (SearcherServices *)context;
 170         linkedServiceInfo *info;
 171
 172         if (!services) { DebugStr("\pFoundInstance: services is NULL"); return; }
 173
 174         info = (linkedServiceInfo *)OTAllocMem(sizeof(linkedServiceInfo));
 175         if (!info) { services->lostRecords = true; return; }
 176
 177         info->services = services;
 178         strcpy(info->name, replyName);
 179         strcpy(info->type, replyType);
 180         strcpy(info->domn, replyDomain);
 181         info->text[0] = 0;
 182         info->add = (flags & kDNSServiceFlagsAdd) ? true : false;
 183         info->dom = false;
 184
 185         if (!info->add) // If TTL == 0 we're deleting a service,
 186                 OTLIFOEnqueue(&services->serviceinfolist, &info->link);
 187         else                                                            // else we're adding a new service
 188                 DNSServiceResolve(&info->sdRef, 0, 0, info->name, info->type, info->domn, FoundInstanceInfo, info);
 189         }
 190
 191 // YieldSomeTime() just cooperatively yields some time to other processes running on classic Mac OS
 192 static Boolean YieldSomeTime(UInt32 milliseconds)
 193         {
 194         extern Boolean SIOUXQuitting;
 195         EventRecord e;
 196         WaitNextEvent(everyEvent, &e, milliseconds / 17, NULL);
 197         SIOUXHandleOneEvent(&e);
 198         return(SIOUXQuitting);
 199         }
 200
 201 int main()
 202         {
 203         OSStatus err;
 204         void *tempmem;
 205         DNSServiceRef sdRef;
 206         DNSServiceErrorType dse;
 207
 208         SIOUXSettings.asktosaveonclose = false;
 209         SIOUXSettings.userwindowtitle  = "\pMulticast DNS Searcher";
 210         SIOUXSettings.rows             = 40;
 211         SIOUXSettings.columns          = 160;
 212
 213         printf("DNS-SD Search Client\n\n");
 214         printf("This software reports errors using MacsBug breaks,\n");
 215         printf("so if you don't have MacsBug installed your Mac may crash.\n\n");
 216         printf("******************************************************************************\n\n");
 217
 218         if (DNSServiceBrowse == (void*)kUnresolvedCFragSymbolAddress)
 219                 {
 220                 printf("Before you can use mDNS/DNS-SD clients, you need to place the \n");
 221                 printf("\"Multicast DNS & DNS-SD\" Extension in the Extensions Folder and restart\n");
 222                 return(-1);
 223                 }
 224
 225         err = InitOpenTransport();
 226         if (err) { printf("InitOpenTransport failed %d", err); return(err); }
 227
 228         // Make sure OT has a large enough memory pool for us to draw from at OTNotifier (interrupt) time
 229         tempmem = OTAllocMem(0x10000);
 230         if (tempmem) OTFreeMem(tempmem);
 231         else printf("**** Warning: OTAllocMem couldn't pre-allocate 64K for us.\n");
 232
 233         services.serviceinfolist.fHead = NULL;
 234         services.headerPrinted         = false;
 235         services.lostRecords           = false;
 236
 237         printf("Sending mDNS service lookup queries and waiting for responses...\n\n");
 238     dse = DNSServiceBrowse(&sdRef, 0, 0, "_http._tcp", "", FoundInstance, &services);
 239         if (dse == kDNSServiceErr_NoError)
 240                 {
 241                 while (!YieldSomeTime(35))
 242                         {
 243                         if (services.serviceinfolist.fHead)
 244                                 PrintServiceInfo(&services);
 245
 246                         if (services.lostRecords)
 247                                 {
 248                                 services.lostRecords = false;
 249                                 printf("**** Warning: Out of memory: Records have been missed.\n");
 250                                 }
 251                         }
 252                 }
 253
 254         DNSServiceRefDeallocate(sdRef);
 255         CloseOpenTransport();
 256         return(0);
 257         }