mDNSMacOS9/Searcher.c

   1 /* -*- Mode: C; tab-width: 4 -*-
   2  *
   3  * Copyright (c) 2002-2003 Apple Computer, Inc. All rights reserved.
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #include <stdio.h>                      // For printf()
  19 #include <string.h>                     // For strcpy()
  20
  21 #include <Events.h>                     // For WaitNextEvent()
  22 #include <CodeFragments.h>              // For SIOkUnresolvedCFragSymbolAddress
  23
  24 #include <SIOUX.h>                      // For SIOUXHandleOneEvent()
  25
  26 #include <OpenTransport.h>
  27 #include <OpenTptInternet.h>
  28
  29 #include "dns_sd.h"
  30
  31 #define ns_c_in 1
  32 #define ns_t_a 1
  33
  34 typedef union { UInt8 b[2]; UInt16 NotAnInteger; } mDNSOpaque16;
  35 static UInt16 mDNSVal16(mDNSOpaque16 x) { return((UInt16)(x.b[0]<<8 | x.b[1])); }
  36 static mDNSOpaque16 mDNSOpaque16fromIntVal(UInt16 v)
  37 { mDNSOpaque16 x; x.b[0] = (UInt8)(v >> 8); x.b[1] = (UInt8)(v & 0xFF); return(x); }
  38
  39 typedef struct
  40 {
  41     OTLIFO serviceinfolist;
  42     Boolean headerPrinted;
  43     Boolean lostRecords;
  44 } SearcherServices;
  45
  46 typedef struct
  47 {
  48     SearcherServices *services;
  49     char name[kDNSServiceMaxDomainName];
  50     char type[kDNSServiceMaxDomainName];
  51     char domn[kDNSServiceMaxDomainName];
  52     char host[kDNSServiceMaxDomainName];
  53     char text[kDNSServiceMaxDomainName];
  54     InetHost address;
  55     mDNSOpaque16 notAnIntPort;
  56     DNSServiceRef sdRef;
  57     Boolean add;
  58     Boolean dom;
  59     OTLink link;
  60 } linkedServiceInfo;
  61
  62 static SearcherServices services;
  63
  64 // PrintServiceInfo prints the service information to standard out
  65 // A real application might want to do something else with the information
  66 static void PrintServiceInfo(SearcherServices *services)
  67 {
  68     OTLink *link = OTReverseList(OTLIFOStealList(&services->serviceinfolist));
  69
  70     while (link)
  71     {
  72         linkedServiceInfo *s = OTGetLinkObject(link, linkedServiceInfo, link);
  73
  74         if (!services->headerPrinted)
  75         {
  76             printf("%-55s Type             Domain         Target Host     IP Address      Port Info\n", "Name");
  77             services->headerPrinted = true;
  78         }
  79
  80         if (s->dom)
  81         {
  82             if (s->add) printf("%-55s available for browsing\n", s->domn);
  83             else printf("%-55s no longer available for browsing\n", s->domn);
  84         }
  85         else
  86         {
  87             char ip[16];
  88             unsigned char *p = (unsigned char *)&s->address;
  89             sprintf(ip, "%d.%d.%d.%d", p[0], p[1], p[2], p[3]);
  90             printf("%-55s %-16s %-14s ", s->name, s->type, s->domn);
  91             if (s->add) printf("%-15s %-15s %5d %s\n", s->host, ip, mDNSVal16(s->notAnIntPort), s->text);
  92             else printf("Removed\n");
  93         }
  94
  95         link = link->fNext;
  96         OTFreeMem(s);
  97     }
  98 }
  99
 100 static void FoundInstanceAddress(DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode,
 101                                  const char *fullname, uint16_t rrtype, uint16_t rrclass, uint16_t rdlen, const void *rdata, uint32_t ttl, void *context)
 102 {
 103     linkedServiceInfo *info = (linkedServiceInfo *)context;
 104     SearcherServices *services = info->services;
 105     (void)sdRef;            // Unused
 106     (void)interfaceIndex;   // Unused
 107     (void)fullname;         // Unused
 108     (void)ttl;              // Unused
 109     if (errorCode == kDNSServiceErr_NoError)
 110         if (flags & kDNSServiceFlagsAdd)
 111             if (rrclass == ns_c_in && rrtype == ns_t_a && rdlen == sizeof(info->address))
 112             {
 113                 memcpy(&info->address, rdata, sizeof(info->address));
 114                 DNSServiceRefDeallocate(info->sdRef);
 115                 OTLIFOEnqueue(&services->serviceinfolist, &info->link);
 116             }
 117 }
 118
 119 static void FoundInstanceInfo(DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex,
 120                               DNSServiceErrorType errorCode, const char *fullname, const char *hosttarget, uint16_t notAnIntPort,
 121                               uint16_t txtLen, const unsigned char *txtRecord, void *context)
 122 {
 123     linkedServiceInfo *info = (linkedServiceInfo *)context;
 124     SearcherServices *services = info->services;
 125     (void)sdRef;            // Unused
 126     (void)flags;            // Unused
 127     (void)interfaceIndex;   // Unused
 128     (void)errorCode;        // Unused
 129     (void)fullname;         // Unused
 130     strcpy(info->host, hosttarget);
 131     if (txtLen == 0) info->text[0] = 0;
 132     else
 133     {
 134         strncpy(info->text, (char *)txtRecord+1, txtRecord[0]);
 135         info->text[txtRecord[0]] = 0;
 136     }
 137     info->notAnIntPort.NotAnInteger = notAnIntPort;
 138     DNSServiceRefDeallocate(info->sdRef);
 139     DNSServiceQueryRecord(&info->sdRef, 0, 0, info->host, ns_t_a, ns_c_in, FoundInstanceAddress, info);
 140 }
 141
 142 // When a new named instance of a service is found, FoundInstance() is called.
 143 // In this sample code we turn around and immediately to a DNSServiceResolve() to resolve that service name
 144 // to find its target host, port, and txtinfo, but a normal browing application would just display the name.
 145 // Resolving every single thing you find can be quite hard on the network, so you shouldn't do this
 146 // in a real application. Defer resolving until the client has picked which instance from the
 147 // long list of services is the one they want to use, and then resolve only that one.
 148 static void FoundInstance(DNSServiceRef client, DNSServiceFlags flags, uint32_t interface, DNSServiceErrorType errorCode,
 149                           const char *replyName, const char *replyType, const char *replyDomain, void *context)
 150 {
 151 #pragma unused(client, interface, errorCode)
 152     SearcherServices *services = (SearcherServices *)context;
 153     linkedServiceInfo *info;
 154
 155     if (!services) { DebugStr("\pFoundInstance: services is NULL"); return; }
 156
 157     info = (linkedServiceInfo *)OTAllocMem(sizeof(linkedServiceInfo));
 158     if (!info) { services->lostRecords = true; return; }
 159
 160     info->services = services;
 161     strcpy(info->name, replyName);
 162     strcpy(info->type, replyType);
 163     strcpy(info->domn, replyDomain);
 164     info->text[0] = 0;
 165     info->add = (flags & kDNSServiceFlagsAdd) ? true : false;
 166     info->dom = false;
 167
 168     if (!info->add) // If TTL == 0 we're deleting a service,
 169         OTLIFOEnqueue(&services->serviceinfolist, &info->link);
 170     else                                // else we're adding a new service
 171         DNSServiceResolve(&info->sdRef, 0, 0, info->name, info->type, info->domn, FoundInstanceInfo, info);
 172 }
 173
 174 // YieldSomeTime() just cooperatively yields some time to other processes running on classic Mac OS
 175 static Boolean YieldSomeTime(UInt32 milliseconds)
 176 {
 177     extern Boolean SIOUXQuitting;
 178     EventRecord e;
 179     WaitNextEvent(everyEvent, &e, milliseconds / 17, NULL);
 180     SIOUXHandleOneEvent(&e);
 181     return(SIOUXQuitting);
 182 }
 183
 184 int main()
 185 {
 186     OSStatus err;
 187     void *tempmem;
 188     DNSServiceRef sdRef;
 189     DNSServiceErrorType dse;
 190
 191     SIOUXSettings.asktosaveonclose = false;
 192     SIOUXSettings.userwindowtitle  = "\pMulticast DNS Searcher";
 193     SIOUXSettings.rows             = 40;
 194     SIOUXSettings.columns          = 160;
 195
 196     printf("DNS-SD Search Client\n\n");
 197     printf("This software reports errors using MacsBug breaks,\n");
 198     printf("so if you don't have MacsBug installed your Mac may crash.\n\n");
 199     printf("******************************************************************************\n\n");
 200
 201     if (DNSServiceBrowse == (void*)kUnresolvedCFragSymbolAddress)
 202     {
 203         printf("Before you can use mDNS/DNS-SD clients, you need to place the \n");
 204         printf("\"Multicast DNS & DNS-SD\" Extension in the Extensions Folder and restart\n");
 205         return(-1);
 206     }
 207
 208     err = InitOpenTransport();
 209     if (err) { printf("InitOpenTransport failed %d", err); return(err); }
 210
 211     // Make sure OT has a large enough memory pool for us to draw from at OTNotifier (interrupt) time
 212     tempmem = OTAllocMem(0x10000);
 213     if (tempmem) OTFreeMem(tempmem);
 214     else printf("**** Warning: OTAllocMem couldn't pre-allocate 64K for us.\n");
 215
 216     services.serviceinfolist.fHead = NULL;
 217     services.headerPrinted         = false;
 218     services.lostRecords           = false;
 219
 220     printf("Sending mDNS service lookup queries and waiting for responses...\n\n");
 221     dse = DNSServiceBrowse(&sdRef, 0, 0, "_http._tcp", "", FoundInstance, &services);
 222     if (dse == kDNSServiceErr_NoError)
 223     {
 224         while (!YieldSomeTime(35))
 225         {
 226             if (services.serviceinfolist.fHead)
 227                 PrintServiceInfo(&services);
 228
 229             if (services.lostRecords)
 230             {
 231                 services.lostRecords = false;
 232                 printf("**** Warning: Out of memory: Records have been missed.\n");
 233             }
 234         }
 235     }
 236
 237     DNSServiceRefDeallocate(sdRef);
 238     CloseOpenTransport();
 239     return(0);
 240 }