mDNSPosix/ProxyResponder.c

   1 /*
   2  * Copyright (c) 2002-2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24
  25     Change History (most recent first):
  26
  27 $Log: ProxyResponder.c,v $
  28 Revision 1.24  2003/11/14 21:27:09  cheshire
  29 <rdar://problem/3484766>: Security: Crashing bug in mDNSResponder
  30 Fix code that should use buffer size MAX_ESCAPED_DOMAIN_NAME (1005) instead of 256-byte buffers.
  31
  32 Revision 1.23  2003/10/30 19:39:28  cheshire
  33 Fix warnings on certain compilers
  34
  35 Revision 1.22  2003/08/14 02:19:55  cheshire
  36 <rdar://problem/3375491> Split generic ResourceRecord type into two separate types: AuthRecord and CacheRecord
  37
  38 Revision 1.21  2003/08/12 19:56:26  cheshire
  39 Update to APSL 2.0
  40
  41 Revision 1.20  2003/07/23 00:00:04  cheshire
  42 Add comments
  43
  44 Revision 1.19  2003/07/15 01:55:16  cheshire
  45 <rdar://problem/3315777> Need to implement service registration with subtypes
  46
  47 Revision 1.18  2003/07/02 21:19:58  cheshire
  48 <rdar://problem/3313413> Update copyright notices, etc., in source code comments
  49
  50 Revision 1.17  2003/05/26 03:21:29  cheshire
  51 Tidy up address structure naming:
  52 mDNSIPAddr         => mDNSv4Addr (for consistency with mDNSv6Addr)
  53 mDNSAddr.addr.ipv4 => mDNSAddr.ip.v4
  54 mDNSAddr.addr.ipv6 => mDNSAddr.ip.v6
  55
  56 Revision 1.16  2003/05/26 03:01:28  cheshire
  57 <rdar://problem/3268904> sprintf/vsprintf-style functions are unsafe; use snprintf/vsnprintf instead
  58
  59 Revision 1.15  2003/05/06 00:00:50  cheshire
  60 <rdar://problem/3248914> Rationalize naming of domainname manipulation functions
  61
  62 Revision 1.14  2003/04/25 01:45:57  cheshire
  63 <rdar://problem/3240002> mDNS_RegisterNoSuchService needs to include a host name
  64
  65 Revision 1.13  2003/04/18 22:46:12  cheshire
  66 Fix mistake in 1.8 -- INADDR_NONE is 0xFFFFFFFF, not 0
  67
  68 Revision 1.12  2003/04/16 02:11:07  cheshire
  69 Fixed mDNS_RegisterNoSuchService non-existance function so that it works again
  70
  71 Revision 1.11  2003/03/31 22:49:35  cheshire
  72 Add "$Log" header
  73
  74  */
  75
  76 #include <stdio.h>                      // For printf()
  77 #include <stdlib.h>                     // For exit() etc.
  78 #include <string.h>                     // For strlen() etc.
  79 #include <unistd.h>                     // For select()
  80 #include <errno.h>                      // For errno, EINTR
  81 #include <arpa/inet.h>          // For inet_addr()
  82 #include <netinet/in.h>         // For INADDR_NONE
  83 #include <netdb.h>                      // For gethostbyname()
  84
  85 #include "mDNSClientAPI.h"  // Defines the interface to the client layer above
  86 #include "mDNSPosix.h"      // Defines the specific types needed to run mDNS on this platform
  87 #include "ExampleClientApp.h"
  88
  89 //*************************************************************************************************************
  90 // Globals
  91 static mDNS mDNSStorage;       // mDNS core uses this to store its globals
  92 static mDNS_PlatformSupport PlatformStorage;  // Stores this platform's globals
  93
  94 //*************************************************************************************************************
  95 // Proxy Host Registration
  96
  97 typedef struct
  98         {
  99         mDNSv4Addr ip;
 100         domainlabel hostlabel;          // Conforms to standard DNS letter-digit-hyphen host name rules
 101         AuthRecord RR_A;                // 'A' (address) record for our ".local" name
 102         AuthRecord RR_PTR;              // PTR (reverse lookup) record
 103         } ProxyHost;
 104
 105 mDNSlocal void HostNameCallback(mDNS *const m, AuthRecord *const rr, mStatus result)
 106         {
 107         ProxyHost *f = (ProxyHost*)rr->RecordContext;
 108         if (result == mStatus_NoError)
 109                 debugf("Host name successfully registered: %##s", &rr->resrec.name);
 110         else
 111                 {
 112                 debugf("Host name conflict for %##s", &rr->resrec.name);
 113                 mDNS_Deregister(m, &f->RR_A);
 114                 mDNS_Deregister(m, &f->RR_PTR);
 115                 exit(-1);
 116                 }
 117         }
 118
 119 mDNSlocal mStatus mDNS_RegisterProxyHost(mDNS *m, ProxyHost *p)
 120         {
 121         char buffer[32];
 122
 123         mDNS_SetupResourceRecord(&p->RR_A,   mDNSNULL, mDNSInterface_Any, kDNSType_A,   60, kDNSRecordTypeUnique,      HostNameCallback, p);
 124         mDNS_SetupResourceRecord(&p->RR_PTR, mDNSNULL, mDNSInterface_Any, kDNSType_PTR, 60, kDNSRecordTypeKnownUnique, HostNameCallback, p);
 125
 126         p->RR_A.resrec.name.c[0] = 0;
 127         AppendDomainLabel(&p->RR_A.resrec.name, &p->hostlabel);
 128         AppendLiteralLabelString(&p->RR_A.resrec.name, "local");
 129
 130         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]);
 131         MakeDomainNameFromDNSNameString(&p->RR_PTR.resrec.name, buffer);
 132
 133         p->RR_A.  resrec.rdata->u.ip   = p->ip;
 134         p->RR_PTR.resrec.rdata->u.name = p->RR_A.resrec.name;
 135
 136         mDNS_Register(m, &p->RR_A);
 137         mDNS_Register(m, &p->RR_PTR);
 138
 139         debugf("Made Proxy Host Records for %##s", &p->RR_A.resrec.name);
 140
 141         return(mStatus_NoError);
 142         }
 143
 144 //*************************************************************************************************************
 145 // Service Registration
 146
 147 // This sample ServiceCallback just calls mDNS_RenameAndReregisterService to automatically pick a new
 148 // unique name for the service. For a device such as a printer, this may be appropriate.
 149 // For a device with a user interface, and a screen, and a keyboard, the appropriate
 150 // response may be to prompt the user and ask them to choose a new name for the service.
 151 mDNSlocal void ServiceCallback(mDNS *const m, ServiceRecordSet *const sr, mStatus result)
 152         {
 153         switch (result)
 154                 {
 155                 case mStatus_NoError:      debugf("Callback: %##s Name Registered",   &sr->RR_SRV.resrec.name); break;
 156                 case mStatus_NameConflict: debugf("Callback: %##s Name Conflict",     &sr->RR_SRV.resrec.name); break;
 157                 case mStatus_MemFree:      debugf("Callback: %##s Memory Free",       &sr->RR_SRV.resrec.name); break;
 158                 default:                   debugf("Callback: %##s Unknown Result %d", &sr->RR_SRV.resrec.name, result); break;
 159                 }
 160
 161         if (result == mStatus_NoError)
 162                 {
 163                 char buffer[MAX_ESCAPED_DOMAIN_NAME];
 164                 ConvertDomainNameToCString(&sr->RR_SRV.resrec.name, buffer);
 165                 printf("Service %s now registered and active\n", buffer);
 166                 }
 167
 168         if (result == mStatus_NameConflict)
 169                 {
 170                 char buffer1[MAX_ESCAPED_DOMAIN_NAME], buffer2[MAX_ESCAPED_DOMAIN_NAME];
 171                 ConvertDomainNameToCString(&sr->RR_SRV.resrec.name, buffer1);
 172                 mDNS_RenameAndReregisterService(m, sr, mDNSNULL);
 173                 ConvertDomainNameToCString(&sr->RR_SRV.resrec.name, buffer2);
 174                 printf("Name Conflict! %s renamed as %s\n", buffer1, buffer2);
 175                 }
 176         }
 177
 178 // RegisterService() is a simple wrapper function which takes C string
 179 // parameters, converts them to domainname parameters, and calls mDNS_RegisterService()
 180 mDNSlocal void RegisterService(mDNS *m, ServiceRecordSet *recordset,
 181         const char name[], const char type[], const char domain[],
 182         const domainname *host, mDNSu16 PortAsNumber, int argc, char **argv)
 183         {
 184         domainlabel n;
 185         domainname t, d;
 186         mDNSIPPort port;
 187         unsigned char txtbuffer[1024], *bptr = txtbuffer;
 188         char buffer[MAX_ESCAPED_DOMAIN_NAME];
 189
 190         MakeDomainLabelFromLiteralString(&n, name);
 191         MakeDomainNameFromDNSNameString(&t, type);
 192         MakeDomainNameFromDNSNameString(&d, domain);
 193         port.b[0] = (mDNSu8)(PortAsNumber >> 8);
 194         port.b[1] = (mDNSu8)(PortAsNumber     );
 195         while (argc)
 196                 {
 197                 int len = strlen(argv[0]);
 198                 printf("STR: %s\n", argv[0]);
 199                 bptr[0] = len;
 200                 strcpy((char*)(bptr+1), argv[0]);
 201                 bptr += 1 + len;
 202                 argc--;
 203                 argv++;
 204                 }
 205
 206         mDNS_RegisterService(m, recordset,
 207                 &n, &t, &d,                                     // Name, type, domain
 208                 host, port,                                     // Host and port
 209                 txtbuffer, bptr-txtbuffer,      // TXT data, length
 210                 mDNSNULL, 0,                            // Subtypes
 211                 mDNSInterface_Any,                      // Interace ID
 212                 ServiceCallback, mDNSNULL);     // Callback and context
 213
 214         ConvertDomainNameToCString(&recordset->RR_SRV.resrec.name, buffer);
 215         printf("Made Service Records for %s\n", buffer);
 216         }
 217
 218 //*************************************************************************************************************
 219 // Service non-existence assertion
 220 // (claiming a service name without actually providing a service at that name, to prevent anyone else using that name)
 221 // This is useful to avoid confusion between similar services
 222 // e.g. A printer that implements IPP printing service using the name "My Printer", but doesn't implement LPR service,
 223 // should also claim the LPR service name "My Printer" to stop a different printer offering LPR service under the same name,
 224 // since it would be confusing to users to have two equivalent services with the same name.
 225
 226 mDNSlocal void NoSuchServiceCallback(mDNS *const m, AuthRecord *const rr, mStatus result)
 227         {
 228         domainname *proxyhostname = (domainname *)rr->RecordContext;
 229         switch (result)
 230                 {
 231                 case mStatus_NoError:      debugf("Callback: %##s Name Registered",   &rr->resrec.name); break;
 232                 case mStatus_NameConflict: debugf("Callback: %##s Name Conflict",     &rr->resrec.name); break;
 233                 case mStatus_MemFree:      debugf("Callback: %##s Memory Free",       &rr->resrec.name); break;
 234                 default:                   debugf("Callback: %##s Unknown Result %d", &rr->resrec.name, result); break;
 235                 }
 236
 237         if (result == mStatus_NoError)
 238                 {
 239                 char buffer[MAX_ESCAPED_DOMAIN_NAME];
 240                 ConvertDomainNameToCString(&rr->resrec.name, buffer);
 241                 printf("Non-existence assertion %s now registered and active\n", buffer);
 242                 }
 243
 244         if (result == mStatus_NameConflict)
 245                 {
 246                 domainlabel n;
 247                 domainname t, d;
 248                 char buffer1[MAX_ESCAPED_DOMAIN_NAME], buffer2[MAX_ESCAPED_DOMAIN_NAME];
 249                 ConvertDomainNameToCString(&rr->resrec.name, buffer1);
 250                 DeconstructServiceName(&rr->resrec.name, &n, &t, &d);
 251                 IncrementLabelSuffix(&n, mDNStrue);
 252                 mDNS_RegisterNoSuchService(m, rr, &n, &t, &d, proxyhostname, mDNSInterface_Any, NoSuchServiceCallback, mDNSNULL);
 253                 ConvertDomainNameToCString(&rr->resrec.name, buffer2);
 254                 printf("Name Conflict! %s renamed as %s\n", buffer1, buffer2);
 255                 }
 256         }
 257
 258 mDNSlocal void RegisterNoSuchService(mDNS *m, AuthRecord *const rr, domainname *proxyhostname,
 259         const char name[], const char type[], const char domain[])
 260         {
 261         domainlabel n;
 262         domainname t, d;
 263         char buffer[MAX_ESCAPED_DOMAIN_NAME];
 264         MakeDomainLabelFromLiteralString(&n, name);
 265         MakeDomainNameFromDNSNameString(&t, type);
 266         MakeDomainNameFromDNSNameString(&d, domain);
 267         mDNS_RegisterNoSuchService(m, rr, &n, &t, &d, proxyhostname, mDNSInterface_Any, NoSuchServiceCallback, proxyhostname);
 268         ConvertDomainNameToCString(&rr->resrec.name, buffer);
 269         printf("Made Non-existence Record for %s\n", buffer);
 270         }
 271
 272 //*************************************************************************************************************
 273 // Main
 274
 275 mDNSexport int main(int argc, char **argv)
 276         {
 277         mStatus status;
 278
 279         if (argc < 3) goto usage;
 280
 281         status = mDNS_Init(&mDNSStorage, &PlatformStorage,
 282                 mDNS_Init_NoCache, mDNS_Init_ZeroCacheSize,
 283                 mDNS_Init_DontAdvertiseLocalAddresses,
 284                 mDNS_Init_NoInitCallback, mDNS_Init_NoInitCallbackContext);
 285         if (status) { fprintf(stderr, "Daemon start: mDNS_Init failed %ld\n", status); return(status); }
 286
 287         if (!strcmp(argv[1], "-"))
 288                 {
 289                 domainname proxyhostname;
 290                 AuthRecord proxyrecord;
 291                 if (argc < 5) goto usage;
 292                 proxyhostname.c[0] = 0;
 293                 AppendLiteralLabelString(&proxyhostname, argv[2]);
 294                 AppendLiteralLabelString(&proxyhostname, "local");
 295                 RegisterNoSuchService(&mDNSStorage, &proxyrecord, &proxyhostname, argv[3], argv[4], "local.");
 296                 ExampleClientEventLoop(&mDNSStorage);
 297                 mDNS_Close(&mDNSStorage);
 298                 }
 299         else
 300                 {
 301                 ProxyHost proxyhost;
 302                 ServiceRecordSet proxyservice;
 303
 304                 proxyhost.ip.NotAnInteger = inet_addr(argv[1]);
 305                 if (proxyhost.ip.NotAnInteger == INADDR_NONE)   // INADDR_NONE is 0xFFFFFFFF
 306                         {
 307                         struct hostent *h = gethostbyname(argv[1]);
 308                         if (h) proxyhost.ip.NotAnInteger = *(long*)h->h_addr;
 309                         }
 310                 if (proxyhost.ip.NotAnInteger == INADDR_NONE)   // INADDR_NONE is 0xFFFFFFFF
 311                         {
 312                         fprintf(stderr, "%s is not valid host address\n", argv[1]);
 313                         return(-1);
 314                         }
 315
 316                 MakeDomainLabelFromLiteralString(&proxyhost.hostlabel, argv[2]);
 317
 318                 mDNS_RegisterProxyHost(&mDNSStorage, &proxyhost);
 319
 320                 if (argc >=6)
 321                         RegisterService(&mDNSStorage, &proxyservice, argv[3], argv[4], "local.",
 322                                                         &proxyhost.RR_A.resrec.name, atoi(argv[5]), argc-6, &argv[6]);
 323
 324                 ExampleClientEventLoop(&mDNSStorage);
 325                 mDNS_Close(&mDNSStorage);
 326                 }
 327
 328         return(0);
 329
 330 usage:
 331         fprintf(stderr, "%s ip hostlabel [srvname srvtype port txt [txt ...]]\n", argv[0]);
 332         fprintf(stderr, "ip        Real IP address (or valid host name) of the host where the service actually resides\n");
 333         fprintf(stderr, "hostlabel First label of the dot-local host name to create for this host, e.g. \"foo\" for \"foo.local.\"\n");
 334         fprintf(stderr, "srvname   Descriptive name of service, e.g. \"Stuart's Ink Jet Printer\"\n");
 335         fprintf(stderr, "srvtype   IANA service type, e.g. \"_ipp._tcp\" or \"_ssh._tcp\", etc.\n");
 336         fprintf(stderr, "port      Port number where the service resides (1-65535)\n");
 337         fprintf(stderr, "txt       Additional name/value pairs specified in service definition, e.g. \"pdl=application/postscript\"\n");
 338         fprintf(stderr, "e.g. %s 169.254.12.34 thehost                                (just create a dot-local host name)\n", argv[0]);
 339         fprintf(stderr, "or   %s 169.254.12.34 thehost \"My Printer\" _printer._tcp. 515 rp=lpt1 pdl=application/postscript\n", argv[0]);
 340         fprintf(stderr, "or   %s -             thehost \"My Printer\" _printer._tcp.           (assertion of non-existence)\n", argv[0]);
 341         return(-1);
 342         }