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 strlen() etc.
20
21#include <Events.h>                     // For WaitNextEvent()
22#include <SIOUX.h>                      // For SIOUXHandleOneEvent()
23
24#include "mDNSEmbeddedAPI.h"            // Defines the interface to the client layer above
25
26#include "mDNSMacOS9.h"                 // Defines the specific types needed to run mDNS on this platform
27
28// These don't have to be globals, but their memory does need to remain valid for as
29// long as the search is going on. They are declared as globals here for simplicity.
30static mDNS m;
31static mDNS_PlatformSupport p;
32static ServiceRecordSet p1, p2;
33static AuthRecord availRec1, availRec2;
34static Boolean availRec2Active;
35
36// This sample code just calls mDNS_RenameAndReregisterService to automatically pick a new
37// unique name for the service. For a device such as a printer, this may be appropriate.
38// For a device with a user interface, and a screen, and a keyboard, the appropriate
39// response may be to prompt the user and ask them to choose a new name for the service.
40mDNSlocal void Callback(mDNS *const m, ServiceRecordSet *const sr, mStatus result)
41{
42    switch (result)
43    {
44    case mStatus_NoError:      debugf("Callback: %##s Name Registered",   sr->RR_SRV.resrec.name.c); break;
45    case mStatus_NameConflict: debugf("Callback: %##s Name Conflict",     sr->RR_SRV.resrec.name.c); break;
46    case mStatus_MemFree:      debugf("Callback: %##s Memory Free",       sr->RR_SRV.resrec.name.c); break;
47    default:                   debugf("Callback: %##s Unknown Result %d", sr->RR_SRV.resrec.name.c, result); break;
48    }
49
50    if (result == mStatus_NameConflict) mDNS_RenameAndReregisterService(m, sr, mDNSNULL);
51}
52
53// RegisterService() is a simple wrapper function which takes C string
54// parameters, converts them to domainname parameters, and calls mDNS_RegisterService()
55mDNSlocal void RegisterService(mDNS *m, ServiceRecordSet *recordset,
56                               UInt16 PortAsNumber, const char txtinfo[],
57                               const domainlabel *const n, const char type[], const char domain[])
58{
59    domainname t;
60    domainname d;
61    char buffer[MAX_ESCAPED_DOMAIN_NAME];
62    UInt8 txtbuffer[512];
63
64    MakeDomainNameFromDNSNameString(&t, type);
65    MakeDomainNameFromDNSNameString(&d, domain);
66
67    if (txtinfo)
68    {
69        strncpy((char*)txtbuffer+1, txtinfo, sizeof(txtbuffer)-1);
70        txtbuffer[0] = (UInt8)strlen(txtinfo);
71    }
72    else
73        txtbuffer[0] = 0;
74
75    mDNS_RegisterService(m, recordset,
76                         n, &t, &d,                 // Name, type, domain
77                         mDNSNULL, mDNSOpaque16fromIntVal(PortAsNumber),
78                         txtbuffer, (mDNSu16)(1+txtbuffer[0]), // TXT data, length
79                         mDNSNULL, 0,               // Subtypes (none)
80                         mDNSInterface_Any,         // Interface ID
81                         Callback, mDNSNULL, 0);    // Callback, context, flags
82
83    ConvertDomainNameToCString(recordset->RR_SRV.resrec.name, buffer);
84    printf("Made Service Records for %s\n", buffer);
85}
86
87// RegisterFakeServiceForTesting() simulates the effect of services being registered on
88// dynamically-allocated port numbers. No real service exists on that port -- this is just for testing.
89mDNSlocal void RegisterFakeServiceForTesting(mDNS *m, ServiceRecordSet *recordset, const char txtinfo[],
90                                             const char name[], const char type[], const char domain[])
91{
92    static UInt16 NextPort = 0xF000;
93    domainlabel n;
94    MakeDomainLabelFromLiteralString(&n, name);
95    RegisterService(m, recordset, NextPort++, txtinfo, &n, type, domain);
96}
97
98// Done once on startup, and then again every time our address changes
99mDNSlocal OSStatus mDNSResponderTestSetup(mDNS *m)
100{
101    char buffer[MAX_ESCAPED_DOMAIN_NAME];
102    mDNSv4Addr ip = m->HostInterfaces->ip.ip.v4;
103
104    ConvertDomainNameToCString(&m->MulticastHostname, buffer);
105    printf("Name %s\n", buffer);
106    printf("IP   %d.%d.%d.%d\n", ip.b[0], ip.b[1], ip.b[2], ip.b[3]);
107
108    printf("\n");
109    printf("Registering Service Records\n");
110    // Create example printer discovery records
111    //static ServiceRecordSet p1, p2;
112
113    RegisterFakeServiceForTesting(m, &p1, "", "One", "_raop._tcp.", "local.");
114    RegisterFakeServiceForTesting(m, &p2, "", "Two", "_raop._tcp.", "local.");
115
116    return(kOTNoError);
117}
118
119mDNSlocal void AvailCallback(mDNS *const m, AuthRecord *const rr, mStatus result)
120{
121    Boolean *b = (Boolean *)rr->RecordContext;
122    (void)m; // Unused
123    // Signal that our record is now free for re-use
124    if (result == mStatus_MemFree) *b = false;
125}
126
127mDNSlocal OSStatus mDNSResponderSetAvail(mDNS *m, AuthRecord *rr, ServiceRecordSet *sr)
128{
129    // 1. Initialize required fields of AuthRecord
130    // 2. Set name of subtype PTR record to our special subtype name denoting "available" instances
131    // 3. Set target of subtype PTR record to point to our SRV record (exactly the same as the main service PTR record)
132    // 4. And register it
133    mDNS_SetupResourceRecord(rr, mDNSNULL, mDNSInterface_Any, kDNSType_PTR, 2*3600, kDNSRecordTypeShared, AvailCallback, &availRec2Active);
134    MakeDomainNameFromDNSNameString(rr->resrec.name, "a._sub._raop._tcp.local.");
135    AssignDomainName(&rr->resrec.rdata->u.name, sr->RR_SRV.resrec.name);
136    return(mDNS_Register(m, rr));
137}
138
139// YieldSomeTime() just cooperatively yields some time to other processes running on classic Mac OS
140mDNSlocal Boolean YieldSomeTime(UInt32 milliseconds)
141{
142    extern Boolean SIOUXQuitting;
143    EventRecord e;
144    WaitNextEvent(everyEvent, &e, milliseconds / 17, NULL);
145    SIOUXHandleOneEvent(&e);
146    return(SIOUXQuitting);
147}
148
149int main()
150{
151    mStatus err;
152    Boolean DoneSetup = false;
153    mDNSs32 nextAvail, nextBusy;
154
155    SIOUXSettings.asktosaveonclose = false;
156    SIOUXSettings.userwindowtitle = "\pMulticast DNS Responder";
157
158    printf("Multicast DNS Responder\n\n");
159    printf("This software reports errors using MacsBug breaks,\n");
160    printf("so if you don't have MacsBug installed your Mac may crash.\n\n");
161    printf("******************************************************************************\n");
162
163    err = InitOpenTransport();
164    if (err) { debugf("InitOpenTransport failed %d", err); return(err); }
165
166    err = mDNS_Init(&m, &p, mDNS_Init_NoCache, mDNS_Init_ZeroCacheSize,
167                    mDNS_Init_AdvertiseLocalAddresses, mDNS_Init_NoInitCallback, mDNS_Init_NoInitCallbackContext);
168    if (err) return(err);
169
170    while (!YieldSomeTime(35))
171    {
172#if MDNS_ONLYSYSTEMTASK
173        // For debugging, use "#define MDNS_ONLYSYSTEMTASK 1" and call mDNSPlatformIdle() periodically.
174        // For shipping code, don't define MDNS_ONLYSYSTEMTASK, and you don't need to call mDNSPlatformIdle()
175        extern void mDNSPlatformIdle(mDNS *const m);
176        mDNSPlatformIdle(&m);   // Only needed for debugging version
177#endif
178        if (m.mDNSPlatformStatus == mStatus_NoError && !DoneSetup)
179        {
180            DoneSetup = true;
181            printf("\nListening for mDNS queries...\n");
182            mDNSResponderTestSetup(&m);
183            mDNSResponderSetAvail(&m, &availRec1, &p1);
184            availRec2Active = false;
185            nextAvail = mDNS_TimeNow(&m) + mDNSPlatformOneSecond * 10;
186            nextBusy  = mDNS_TimeNow(&m) + mDNSPlatformOneSecond * 15;
187        }
188
189        if (DoneSetup)
190        {
191            // We check availRec2.RecordType because we don't want to re-register this record
192            // if the previous mDNS_Deregister() has not yet completed
193            if (mDNS_TimeNow(&m) - nextAvail > 0 && !availRec2Active)
194            {
195                printf("Setting Two now available\n");
196                availRec2Active = true;
197                mDNSResponderSetAvail(&m, &availRec2, &p2);
198                nextAvail = nextBusy + mDNSPlatformOneSecond * 10;
199            }
200            else if (mDNS_TimeNow(&m) - nextBusy > 0)
201            {
202                printf("Setting Two now busy\n");
203                mDNS_Deregister(&m, &availRec2);
204                nextBusy = nextAvail + mDNSPlatformOneSecond * 5;
205            }
206        }
207    }
208
209    if (p1.RR_SRV.resrec.RecordType) mDNS_DeregisterService(&m, &p1);
210    if (p2.RR_SRV.resrec.RecordType) mDNS_DeregisterService(&m, &p2);
211    if (availRec1.resrec.RecordType) mDNS_Deregister(&m, &availRec1);
212    if (availRec2Active) mDNS_Deregister(&m, &availRec2);
213
214    mDNS_Close(&m);
215
216    return(0);
217}
218