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