mDNSPosix/ProxyResponder.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: ProxyResponder.c,v $
  26 Revision 1.22  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 1.21  2003/08/12 19:56:26  cheshire
  30 Update to APSL 2.0
  31
  32 Revision 1.20  2003/07/23 00:00:04  cheshire
  33 Add comments
  34
  35 Revision 1.19  2003/07/15 01:55:16  cheshire
  36 <rdar://problem/3315777> Need to implement service registration with subtypes
  37
  38 Revision 1.18  2003/07/02 21:19:58  cheshire
  39 <rdar://problem/3313413> Update copyright notices, etc., in source code comments
  40
  41 Revision 1.17  2003/05/26 03:21:29  cheshire
  42 Tidy up address structure naming:
  43 mDNSIPAddr         => mDNSv4Addr (for consistency with mDNSv6Addr)
  44 mDNSAddr.addr.ipv4 => mDNSAddr.ip.v4
  45 mDNSAddr.addr.ipv6 => mDNSAddr.ip.v6
  46
  47 Revision 1.16  2003/05/26 03:01:28  cheshire
  48 <rdar://problem/3268904> sprintf/vsprintf-style functions are unsafe; use snprintf/vsnprintf instead
  49
  50 Revision 1.15  2003/05/06 00:00:50  cheshire
  51 <rdar://problem/3248914> Rationalize naming of domainname manipulation functions
  52
  53 Revision 1.14  2003/04/25 01:45:57  cheshire
  54 <rdar://problem/3240002> mDNS_RegisterNoSuchService needs to include a host name
  55
  56 Revision 1.13  2003/04/18 22:46:12  cheshire
  57 Fix mistake in 1.8 -- INADDR_NONE is 0xFFFFFFFF, not 0
  58
  59 Revision 1.12  2003/04/16 02:11:07  cheshire
  60 Fixed mDNS_RegisterNoSuchService non-existance function so that it works again
  61
  62 Revision 1.11  2003/03/31 22:49:35  cheshire
  63 Add "$Log" header
  64
  65  */
  66
  67 #include <stdio.h>                      // For printf()
  68 #include <stdlib.h>                     // For exit() etc.
  69 #include <string.h>                     // For strlen() etc.
  70 #include <unistd.h>                     // For select()
  71 #include <errno.h>                      // For errno, EINTR
  72 #include <arpa/inet.h>          // For inet_addr()
  73 #include <netinet/in.h>         // For INADDR_NONE
  74 #include <netdb.h>                      // For gethostbyname()
  75
  76 #include "mDNSClientAPI.h"  // Defines the interface to the client layer above
  77 #include "mDNSPosix.h"      // Defines the specific types needed to run mDNS on this platform
  78 #include "ExampleClientApp.h"
  79
  80 //*************************************************************************************************************
  81 // Globals
  82 static mDNS mDNSStorage;       // mDNS core uses this to store its globals
  83 static mDNS_PlatformSupport PlatformStorage;  // Stores this platform's globals
  84
  85 //*************************************************************************************************************
  86 // Proxy Host Registration
  87
  88 typedef struct
  89         {
  90         mDNSv4Addr ip;
  91         domainlabel hostlabel;          // Conforms to standard DNS letter-digit-hyphen host name rules
  92         AuthRecord RR_A;                // 'A' (address) record for our ".local" name
  93         AuthRecord RR_PTR;              // PTR (reverse lookup) record
  94         } ProxyHost;
  95
  96 mDNSlocal void HostNameCallback(mDNS *const m, AuthRecord *const rr, mStatus result)
  97         {
  98         ProxyHost *f = (ProxyHost*)rr->RecordContext;
  99         if (result == mStatus_NoError)
 100                 debugf("Host name successfully registered: %##s", &rr->resrec.name);
 101         else
 102                 {
 103                 debugf("Host name conflict for %##s", &rr->resrec.name);
 104                 mDNS_Deregister(m, &f->RR_A);
 105                 mDNS_Deregister(m, &f->RR_PTR);
 106                 exit(-1);
 107                 }
 108         }
 109
 110 mDNSlocal mStatus mDNS_RegisterProxyHost(mDNS *m, ProxyHost *p)
 111         {
 112         char buffer[32];
 113
 114         mDNS_SetupResourceRecord(&p->RR_A,   mDNSNULL, mDNSInterface_Any, kDNSType_A,   60, kDNSRecordTypeUnique,      HostNameCallback, p);
 115         mDNS_SetupResourceRecord(&p->RR_PTR, mDNSNULL, mDNSInterface_Any, kDNSType_PTR, 60, kDNSRecordTypeKnownUnique, HostNameCallback, p);
 116
 117         p->RR_A.resrec.name.c[0] = 0;
 118         AppendDomainLabel(&p->RR_A.resrec.name, &p->hostlabel);
 119         AppendLiteralLabelString(&p->RR_A.resrec.name, "local");
 120
 121         mDNS_snprintf(buffer, sizeof(buffer), "%d.%d.%d.%d.in-addr.arpa.", p->ip.b[3], p->ip.b[2], p->ip.b[1], p->ip.b[0]);
 122         MakeDomainNameFromDNSNameString(&p->RR_PTR.resrec.name, buffer);
 123
 124         p->RR_A.  resrec.rdata->u.ip   = p->ip;
 125         p->RR_PTR.resrec.rdata->u.name = p->RR_A.resrec.name;
 126
 127         mDNS_Register(m, &p->RR_A);
 128         mDNS_Register(m, &p->RR_PTR);
 129
 130         debugf("Made Proxy Host Records for %##s", &p->RR_A.resrec.name);
 131
 132         return(mStatus_NoError);
 133         }
 134
 135 //*************************************************************************************************************
 136 // Service Registration
 137
 138 // This sample ServiceCallback just calls mDNS_RenameAndReregisterService to automatically pick a new
 139 // unique name for the service. For a device such as a printer, this may be appropriate.
 140 // For a device with a user interface, and a screen, and a keyboard, the appropriate
 141 // response may be to prompt the user and ask them to choose a new name for the service.
 142 mDNSlocal void ServiceCallback(mDNS *const m, ServiceRecordSet *const sr, mStatus result)
 143         {
 144         switch (result)
 145                 {
 146                 case mStatus_NoError:      debugf("Callback: %##s Name Registered",   &sr->RR_SRV.resrec.name); break;
 147                 case mStatus_NameConflict: debugf("Callback: %##s Name Conflict",     &sr->RR_SRV.resrec.name); break;
 148                 case mStatus_MemFree:      debugf("Callback: %##s Memory Free",       &sr->RR_SRV.resrec.name); break;
 149                 default:                   debugf("Callback: %##s Unknown Result %d", &sr->RR_SRV.resrec.name, result); break;
 150                 }
 151
 152         if (result == mStatus_NoError)
 153                 {
 154                 char buffer[256];
 155                 ConvertDomainNameToCString_unescaped(&sr->RR_SRV.resrec.name, buffer);
 156                 printf("Service %s now registered and active\n", buffer);
 157                 }
 158
 159         if (result == mStatus_NameConflict)
 160                 {
 161                 char buffer1[256], buffer2[256];
 162                 ConvertDomainNameToCString_unescaped(&sr->RR_SRV.resrec.name, buffer1);
 163                 mDNS_RenameAndReregisterService(m, sr, mDNSNULL);
 164                 ConvertDomainNameToCString_unescaped(&sr->RR_SRV.resrec.name, buffer2);
 165                 printf("Name Conflict! %s renamed as %s\n", buffer1, buffer2);
 166                 }
 167         }
 168
 169 // RegisterService() is a simple wrapper function which takes C string
 170 // parameters, converts them to domainname parameters, and calls mDNS_RegisterService()
 171 mDNSlocal void RegisterService(mDNS *m, ServiceRecordSet *recordset,
 172         const char name[], const char type[], const char domain[],
 173         const domainname *host, mDNSu16 PortAsNumber, int argc, char **argv)
 174         {
 175         domainlabel n;
 176         domainname t, d;
 177         mDNSIPPort port;
 178         unsigned char buffer[1024], *bptr = buffer;
 179
 180         MakeDomainLabelFromLiteralString(&n, name);
 181         MakeDomainNameFromDNSNameString(&t, type);
 182         MakeDomainNameFromDNSNameString(&d, domain);
 183         port.b[0] = (mDNSu8)(PortAsNumber >> 8);
 184         port.b[1] = (mDNSu8)(PortAsNumber     );
 185         while (argc)
 186                 {
 187                 int len = strlen(argv[0]);
 188                 printf("STR: %s\n", argv[0]);
 189                 bptr[0] = len;
 190                 strcpy(bptr+1, argv[0]);
 191                 bptr += 1 + len;
 192                 argc--;
 193                 argv++;
 194                 }
 195
 196         mDNS_RegisterService(m, recordset,
 197                 &n, &t, &d,                                     // Name, type, domain
 198                 host, port,                                     // Host and port
 199                 buffer, bptr-buffer,            // TXT data, length
 200                 mDNSNULL, 0,                            // Subtypes
 201                 mDNSInterface_Any,                      // Interace ID
 202                 ServiceCallback, mDNSNULL);     // Callback and context
 203
 204         ConvertDomainNameToCString_unescaped(&recordset->RR_SRV.resrec.name, buffer);
 205         printf("Made Service Records for %s\n", buffer);
 206         }
 207
 208 //*************************************************************************************************************
 209 // Service non-existence assertion
 210 // (claiming a service name without actually providing a service at that name, to prevent anyone else using that name)
 211 // This is useful to avoid confusion between similar services
 212 // e.g. A printer that implements IPP printing service using the name "My Printer", but doesn't implement LPR service,
 213 // should also claim the LPR service name "My Printer" to stop a different printer offering LPR service under the same name,
 214 // since it would be confusing to users to have two equivalent services with the same name.
 215
 216 mDNSlocal void NoSuchServiceCallback(mDNS *const m, AuthRecord *const rr, mStatus result)
 217         {
 218         domainname *proxyhostname = (domainname *)rr->RecordContext;
 219         switch (result)
 220                 {
 221                 case mStatus_NoError:      debugf("Callback: %##s Name Registered",   &rr->resrec.name); break;
 222                 case mStatus_NameConflict: debugf("Callback: %##s Name Conflict",     &rr->resrec.name); break;
 223                 case mStatus_MemFree:      debugf("Callback: %##s Memory Free",       &rr->resrec.name); break;
 224                 default:                   debugf("Callback: %##s Unknown Result %d", &rr->resrec.name, result); break;
 225                 }
 226
 227         if (result == mStatus_NoError)
 228                 {
 229                 char buffer[256];
 230                 ConvertDomainNameToCString_unescaped(&rr->resrec.name, buffer);
 231                 printf("Non-existence assertion %s now registered and active\n", buffer);
 232                 }
 233
 234         if (result == mStatus_NameConflict)
 235                 {
 236                 domainlabel n;
 237                 domainname t, d;
 238                 char buffer1[256], buffer2[256];
 239                 ConvertDomainNameToCString_unescaped(&rr->resrec.name, buffer1);
 240                 DeconstructServiceName(&rr->resrec.name, &n, &t, &d);
 241                 IncrementLabelSuffix(&n, mDNStrue);
 242                 mDNS_RegisterNoSuchService(m, rr, &n, &t, &d, proxyhostname, mDNSInterface_Any, NoSuchServiceCallback, mDNSNULL);
 243                 ConvertDomainNameToCString_unescaped(&rr->resrec.name, buffer2);
 244                 printf("Name Conflict! %s renamed as %s\n", buffer1, buffer2);
 245                 }
 246         }
 247
 248 mDNSlocal void RegisterNoSuchService(mDNS *m, AuthRecord *const rr, domainname *proxyhostname,
 249         const char name[], const char type[], const char domain[])
 250         {
 251         domainlabel n;
 252         domainname t, d;
 253         unsigned char buffer[256];
 254         MakeDomainLabelFromLiteralString(&n, name);
 255         MakeDomainNameFromDNSNameString(&t, type);
 256         MakeDomainNameFromDNSNameString(&d, domain);
 257         mDNS_RegisterNoSuchService(m, rr, &n, &t, &d, proxyhostname, mDNSInterface_Any, NoSuchServiceCallback, proxyhostname);
 258         ConvertDomainNameToCString_unescaped(&rr->resrec.name, buffer);
 259         printf("Made Non-existence Record for %s\n", buffer);
 260         }
 261
 262 //*************************************************************************************************************
 263 // Main
 264
 265 mDNSexport int main(int argc, char **argv)
 266         {
 267         mStatus status;
 268
 269         if (argc < 3) goto usage;
 270
 271         status = mDNS_Init(&mDNSStorage, &PlatformStorage,
 272                 mDNS_Init_NoCache, mDNS_Init_ZeroCacheSize,
 273                 mDNS_Init_DontAdvertiseLocalAddresses,
 274                 mDNS_Init_NoInitCallback, mDNS_Init_NoInitCallbackContext);
 275         if (status) { fprintf(stderr, "Daemon start: mDNS_Init failed %ld\n", status); return(status); }
 276
 277         if (!strcmp(argv[1], "-"))
 278                 {
 279                 domainname proxyhostname;
 280                 AuthRecord proxyrecord;
 281                 if (argc < 5) goto usage;
 282                 proxyhostname.c[0] = 0;
 283                 AppendLiteralLabelString(&proxyhostname, argv[2]);
 284                 AppendLiteralLabelString(&proxyhostname, "local");
 285                 RegisterNoSuchService(&mDNSStorage, &proxyrecord, &proxyhostname, argv[3], argv[4], "local.");
 286                 ExampleClientEventLoop(&mDNSStorage);
 287                 mDNS_Close(&mDNSStorage);
 288                 }
 289         else
 290                 {
 291                 ProxyHost proxyhost;
 292                 ServiceRecordSet proxyservice;
 293
 294                 proxyhost.ip.NotAnInteger = inet_addr(argv[1]);
 295                 if (proxyhost.ip.NotAnInteger == INADDR_NONE)   // INADDR_NONE is 0xFFFFFFFF
 296                         {
 297                         struct hostent *h = gethostbyname(argv[1]);
 298                         if (h) proxyhost.ip.NotAnInteger = *(long*)h->h_addr;
 299                         }
 300                 if (proxyhost.ip.NotAnInteger == INADDR_NONE)   // INADDR_NONE is 0xFFFFFFFF
 301                         {
 302                         fprintf(stderr, "%s is not valid host address\n", argv[1]);
 303                         return(-1);
 304                         }
 305
 306                 MakeDomainLabelFromLiteralString(&proxyhost.hostlabel, argv[2]);
 307
 308                 mDNS_RegisterProxyHost(&mDNSStorage, &proxyhost);
 309
 310                 if (argc >=6)
 311                         RegisterService(&mDNSStorage, &proxyservice, argv[3], argv[4], "local.",
 312                                                         &proxyhost.RR_A.resrec.name, atoi(argv[5]), argc-6, &argv[6]);
 313
 314                 ExampleClientEventLoop(&mDNSStorage);
 315                 mDNS_Close(&mDNSStorage);
 316                 }
 317
 318         return(0);
 319
 320 usage:
 321         fprintf(stderr, "%s ip hostlabel [srvname srvtype port txt [txt ...]]\n", argv[0]);
 322         fprintf(stderr, "ip        Real IP address (or valid host name) of the host where the service actually resides\n");
 323         fprintf(stderr, "hostlabel First label of the dot-local host name to create for this host, e.g. \"foo\" for \"foo.local.\"\n");
 324         fprintf(stderr, "srvname   Descriptive name of service, e.g. \"Stuart's Ink Jet Printer\"\n");
 325         fprintf(stderr, "srvtype   IANA service type, e.g. \"_ipp._tcp\" or \"_ssh._tcp\", etc.\n");
 326         fprintf(stderr, "port      Port number where the service resides (1-65535)\n");
 327         fprintf(stderr, "txt       Additional name/value pairs specified in service definition, e.g. \"pdl=application/postscript\"\n");
 328         fprintf(stderr, "e.g. %s 169.254.12.34 thehost                                (just create a dot-local host name)\n", argv[0]);
 329         fprintf(stderr, "or   %s 169.254.12.34 thehost \"My Printer\" _printer._tcp. 515 rp=lpt1 pdl=application/postscript\n", argv[0]);
 330         fprintf(stderr, "or   %s -             thehost \"My Printer\" _printer._tcp.           (assertion of non-existence)\n", argv[0]);
 331         return(-1);
 332         }