1 /* -*- Mode: C; tab-width: 4 -*-
3 * Copyright (c) 2002-2015 Apple Inc. All rights reserved.
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
9 * http://www.apache.org/licenses/LICENSE-2.0
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.
18 // Set mDNS_InstantiateInlines to tell mDNSEmbeddedAPI.h to instantiate inline functions, if necessary
19 #define mDNS_InstantiateInlines 1
20 #include "DNSCommon.h"
21 #include "CryptoAlg.h"
22 #include "anonymous.h"
28 // Disable certain benign warnings with Microsoft compilers
29 #if (defined(_MSC_VER))
30 // Disable "conditional expression is constant" warning for debug macros.
31 // Otherwise, this generates warnings for the perfectly natural construct "while(1)"
32 // If someone knows a variant way of writing "while(1)" that doesn't generate warning messages, please let us know
33 #pragma warning(disable:4127)
34 // Disable "array is too small to include a terminating null character" warning
35 // -- domain labels have an initial length byte, not a terminating null character
36 #pragma warning(disable:4295)
39 // ***************************************************************************
40 #if COMPILER_LIKES_PRAGMA_MARK
41 #pragma mark - Program Constants
44 mDNSexport const mDNSInterfaceID mDNSInterface_Any = 0;
45 mDNSexport const mDNSInterfaceID mDNSInterfaceMark = (mDNSInterfaceID)-1;
46 mDNSexport const mDNSInterfaceID mDNSInterface_LocalOnly = (mDNSInterfaceID)-2;
47 mDNSexport const mDNSInterfaceID mDNSInterface_Unicast = (mDNSInterfaceID)-3;
48 mDNSexport const mDNSInterfaceID mDNSInterface_P2P = (mDNSInterfaceID)-4;
49 mDNSexport const mDNSInterfaceID uDNSInterfaceMark = (mDNSInterfaceID)-5;
50 mDNSexport const mDNSInterfaceID mDNSInterface_BLE = (mDNSInterfaceID)-6;
52 // Note: Microsoft's proposed "Link Local Multicast Name Resolution Protocol" (LLMNR) is essentially a limited version of
53 // Multicast DNS, using the same packet formats, naming syntax, and record types as Multicast DNS, but on a different UDP
54 // port and multicast address, which means it won't interoperate with the existing installed base of Multicast DNS responders.
55 // LLMNR uses IPv4 multicast address 224.0.0.252, IPv6 multicast address FF02::0001:0003, and UDP port 5355.
56 // Uncomment the appropriate lines below to build a special Multicast DNS responder for testing interoperability
57 // with Microsoft's LLMNR client code.
59 #define DiscardPortAsNumber 9
60 #define SSHPortAsNumber 22
61 #define UnicastDNSPortAsNumber 53
62 #define SSDPPortAsNumber 1900
63 #define IPSECPortAsNumber 4500
64 #define NSIPCPortAsNumber 5030 // Port used for dnsextd to talk to local nameserver bound to loopback
65 #define NATPMPAnnouncementPortAsNumber 5350
66 #define NATPMPPortAsNumber 5351
67 #define DNSEXTPortAsNumber 5352 // Port used for end-to-end DNS operations like LLQ, Updates with Leases, etc.
68 #define MulticastDNSPortAsNumber 5353
69 #define LoopbackIPCPortAsNumber 5354
70 //#define MulticastDNSPortAsNumber 5355 // LLMNR
71 #define PrivateDNSPortAsNumber 5533
73 mDNSexport const mDNSIPPort DiscardPort = { { DiscardPortAsNumber >> 8, DiscardPortAsNumber & 0xFF } };
74 mDNSexport const mDNSIPPort SSHPort = { { SSHPortAsNumber >> 8, SSHPortAsNumber & 0xFF } };
75 mDNSexport const mDNSIPPort UnicastDNSPort = { { UnicastDNSPortAsNumber >> 8, UnicastDNSPortAsNumber & 0xFF } };
76 mDNSexport const mDNSIPPort SSDPPort = { { SSDPPortAsNumber >> 8, SSDPPortAsNumber & 0xFF } };
77 mDNSexport const mDNSIPPort IPSECPort = { { IPSECPortAsNumber >> 8, IPSECPortAsNumber & 0xFF } };
78 mDNSexport const mDNSIPPort NSIPCPort = { { NSIPCPortAsNumber >> 8, NSIPCPortAsNumber & 0xFF } };
79 mDNSexport const mDNSIPPort NATPMPAnnouncementPort = { { NATPMPAnnouncementPortAsNumber >> 8, NATPMPAnnouncementPortAsNumber & 0xFF } };
80 mDNSexport const mDNSIPPort NATPMPPort = { { NATPMPPortAsNumber >> 8, NATPMPPortAsNumber & 0xFF } };
81 mDNSexport const mDNSIPPort DNSEXTPort = { { DNSEXTPortAsNumber >> 8, DNSEXTPortAsNumber & 0xFF } };
82 mDNSexport const mDNSIPPort MulticastDNSPort = { { MulticastDNSPortAsNumber >> 8, MulticastDNSPortAsNumber & 0xFF } };
83 mDNSexport const mDNSIPPort LoopbackIPCPort = { { LoopbackIPCPortAsNumber >> 8, LoopbackIPCPortAsNumber & 0xFF } };
84 mDNSexport const mDNSIPPort PrivateDNSPort = { { PrivateDNSPortAsNumber >> 8, PrivateDNSPortAsNumber & 0xFF } };
86 mDNSexport const OwnerOptData zeroOwner = { 0, 0, { { 0 } }, { { 0 } }, { { 0 } } };
88 mDNSexport const mDNSIPPort zeroIPPort = { { 0 } };
89 mDNSexport const mDNSv4Addr zerov4Addr = { { 0 } };
90 mDNSexport const mDNSv6Addr zerov6Addr = { { 0 } };
91 mDNSexport const mDNSEthAddr zeroEthAddr = { { 0 } };
92 mDNSexport const mDNSv4Addr onesIPv4Addr = { { 255, 255, 255, 255 } };
93 mDNSexport const mDNSv6Addr onesIPv6Addr = { { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 } };
94 mDNSexport const mDNSEthAddr onesEthAddr = { { 255, 255, 255, 255, 255, 255 } };
95 mDNSexport const mDNSAddr zeroAddr = { mDNSAddrType_None, {{{ 0 }}} };
97 mDNSexport const mDNSv4Addr AllDNSAdminGroup = { { 239, 255, 255, 251 } };
98 mDNSexport const mDNSv4Addr AllHosts_v4 = { { 224, 0, 0, 1 } }; // For NAT-PMP & PCP Annoucements
99 mDNSexport const mDNSv6Addr AllHosts_v6 = { { 0xFF,0x02,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x01 } };
100 mDNSexport const mDNSv6Addr NDP_prefix = { { 0xFF,0x02,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x01, 0xFF,0x00,0x00,0xFB } }; // FF02:0:0:0:0:1:FF00::/104
101 mDNSexport const mDNSEthAddr AllHosts_v6_Eth = { { 0x33, 0x33, 0x00, 0x00, 0x00, 0x01 } };
102 mDNSexport const mDNSAddr AllDNSLinkGroup_v4 = { mDNSAddrType_IPv4, { { { 224, 0, 0, 251 } } } };
103 //mDNSexport const mDNSAddr AllDNSLinkGroup_v4 = { mDNSAddrType_IPv4, { { { 224, 0, 0, 252 } } } }; // LLMNR
104 mDNSexport const mDNSAddr AllDNSLinkGroup_v6 = { mDNSAddrType_IPv6, { { { 0xFF,0x02,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0xFB } } } };
105 //mDNSexport const mDNSAddr AllDNSLinkGroup_v6 = { mDNSAddrType_IPv6, { { { 0xFF,0x02,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x01,0x00,0x03 } } } }; // LLMNR
107 mDNSexport const mDNSOpaque16 zeroID = { { 0, 0 } };
108 mDNSexport const mDNSOpaque16 onesID = { { 255, 255 } };
109 mDNSexport const mDNSOpaque16 QueryFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_StdQuery, 0 } };
110 mDNSexport const mDNSOpaque16 uQueryFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_StdQuery | kDNSFlag0_RD, 0 } };
111 mDNSexport const mDNSOpaque16 DNSSecQFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_StdQuery | kDNSFlag0_RD, kDNSFlag1_CD } };
112 mDNSexport const mDNSOpaque16 ResponseFlags = { { kDNSFlag0_QR_Response | kDNSFlag0_OP_StdQuery | kDNSFlag0_AA, 0 } };
113 mDNSexport const mDNSOpaque16 UpdateReqFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_Update, 0 } };
114 mDNSexport const mDNSOpaque16 UpdateRespFlags = { { kDNSFlag0_QR_Response | kDNSFlag0_OP_Update, 0 } };
115 mDNSexport const mDNSOpaque16 SubscribeFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_Subscribe, 0 } };
116 mDNSexport const mDNSOpaque16 UnSubscribeFlags= { { kDNSFlag0_QR_Query | kDNSFlag0_OP_UnSubscribe, 0 } };
118 mDNSexport const mDNSOpaque64 zeroOpaque64 = { { 0 } };
119 mDNSexport const mDNSOpaque128 zeroOpaque128 = { { 0 } };
121 // ***************************************************************************
122 #if COMPILER_LIKES_PRAGMA_MARK
124 #pragma mark - General Utility Functions
127 // return true for RFC1918 private addresses
128 mDNSexport mDNSBool mDNSv4AddrIsRFC1918(const mDNSv4Addr * const addr)
130 return ((addr->b[0] == 10) || // 10/8 prefix
131 (addr->b[0] == 172 && (addr->b[1] & 0xF0) == 16) || // 172.16/12
132 (addr->b[0] == 192 && addr->b[1] == 168)); // 192.168/16
135 mDNSexport void mDNSAddrMapIPv4toIPv6(mDNSv4Addr* in, mDNSv6Addr* out)
141 out->b[12] = in->b[0];
142 out->b[13] = in->b[1];
143 out->b[14] = in->b[2];
144 out->b[15] = in->b[3];
147 mDNSexport mDNSBool mDNSAddrIPv4FromMappedIPv6(mDNSv6Addr *in, mDNSv4Addr* out)
149 if (in->l[0] != 0 || in->l[1] != 0 || in->w[4] != 0 || in->w[5] != 0xffff)
152 out->NotAnInteger = in->l[3];
156 mDNSexport NetworkInterfaceInfo *GetFirstActiveInterface(NetworkInterfaceInfo *intf)
158 while (intf && !intf->InterfaceActive) intf = intf->next;
162 mDNSexport mDNSInterfaceID GetNextActiveInterfaceID(const NetworkInterfaceInfo *intf)
164 const NetworkInterfaceInfo *next = GetFirstActiveInterface(intf->next);
165 if (next) return(next->InterfaceID);else return(mDNSNULL);
168 mDNSexport mDNSu32 NumCacheRecordsForInterfaceID(const mDNS *const m, mDNSInterfaceID id)
170 mDNSu32 slot, used = 0;
172 const CacheRecord *rr;
173 FORALL_CACHERECORDS(slot, cg, rr)
175 if (rr->resrec.InterfaceID == id)
181 mDNSexport char *DNSTypeName(mDNSu16 rrtype)
185 case kDNSType_A: return("Addr");
186 case kDNSType_NS: return("NS");
187 case kDNSType_CNAME: return("CNAME");
188 case kDNSType_SOA: return("SOA");
189 case kDNSType_NULL: return("NULL");
190 case kDNSType_PTR: return("PTR");
191 case kDNSType_HINFO: return("HINFO");
192 case kDNSType_TXT: return("TXT");
193 case kDNSType_AAAA: return("AAAA");
194 case kDNSType_SRV: return("SRV");
195 case kDNSType_OPT: return("OPT");
196 case kDNSType_NSEC: return("NSEC");
197 case kDNSType_NSEC3: return("NSEC3");
198 case kDNSType_NSEC3PARAM: return("NSEC3PARAM");
199 case kDNSType_TSIG: return("TSIG");
200 case kDNSType_RRSIG: return("RRSIG");
201 case kDNSType_DNSKEY: return("DNSKEY");
202 case kDNSType_DS: return("DS");
203 case kDNSQType_ANY: return("ANY");
205 static char buffer[16];
206 mDNS_snprintf(buffer, sizeof(buffer), "TYPE%d", rrtype);
212 mDNSlocal char *DNSSECAlgName(mDNSu8 alg)
216 case CRYPTO_RSA_SHA1: return "RSA_SHA1";
217 case CRYPTO_DSA_NSEC3_SHA1: return "DSA_NSEC3_SHA1";
218 case CRYPTO_RSA_NSEC3_SHA1: return "RSA_NSEC3_SHA1";
219 case CRYPTO_RSA_SHA256: return "RSA_SHA256";
220 case CRYPTO_RSA_SHA512: return "RSA_SHA512";
222 static char algbuffer[16];
223 mDNS_snprintf(algbuffer, sizeof(algbuffer), "ALG%d", alg);
229 mDNSlocal char *DNSSECDigestName(mDNSu8 digest)
233 case SHA1_DIGEST_TYPE: return "SHA1";
234 case SHA256_DIGEST_TYPE: return "SHA256";
237 static char digbuffer[16];
238 mDNS_snprintf(digbuffer, sizeof(digbuffer), "DIG%d", digest);
244 mDNSexport mDNSu32 swap32(mDNSu32 x)
246 mDNSu8 *ptr = (mDNSu8 *)&x;
247 return (mDNSu32)((mDNSu32)ptr[0] << 24 | (mDNSu32)ptr[1] << 16 | (mDNSu32)ptr[2] << 8 | ptr[3]);
250 mDNSexport mDNSu16 swap16(mDNSu16 x)
252 mDNSu8 *ptr = (mDNSu8 *)&x;
253 return (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]);
256 // RFC 4034 Appendix B: Get the keyid of a DNS KEY. It is not transmitted
257 // explicitly on the wire.
259 // Note: This just helps narrow down the list of keys to look at. It is possible
260 // for two DNS keys to have the same ID i.e., key ID is not a unqiue tag. We ignore
263 // 1st argument - the RDATA part of the DNSKEY RR
264 // 2nd argument - the RDLENGTH
266 mDNSlocal mDNSu32 keytag(mDNSu8 *key, mDNSu32 keysize)
271 for (ac = 0, i = 0; i < keysize; ++i)
272 ac += (i & 1) ? key[i] : key[i] << 8;
273 ac += (ac >> 16) & 0xFFFF;
277 mDNSexport int baseEncode(char *buffer, int blen, const mDNSu8 *data, int len, int encAlg)
280 mDNSu8 *outputBuffer;
283 ctx = AlgCreate(ENC_ALG, encAlg);
286 LogMsg("baseEncode: AlgCreate failed\n");
289 AlgAdd(ctx, data, len);
290 outputBuffer = AlgEncode(ctx);
294 // Note: don't include any spaces in the format string below. This
295 // is also used by NSEC3 code for proving non-existence where it
296 // needs the base32 encoding without any spaces etc.
297 length = mDNS_snprintf(buffer, blen, "%s", outputBuffer);
303 mDNSlocal void PrintTypeBitmap(const mDNSu8 *bmap, int bitmaplen, char *const buffer, mDNSu32 length)
307 while (bitmaplen > 0)
313 LogMsg("PrintTypeBitmap: malformed bitmap, bitmaplen %d short", bitmaplen);
320 if (bitmaplen < wlen || wlen < 1 || wlen > 32)
322 LogInfo("PrintTypeBitmap: malformed nsec, bitmaplen %d wlen %d", bitmaplen, wlen);
325 if (win < 0 || win >= 256)
327 LogInfo("PrintTypeBitmap: malformed nsec, bad window win %d", win);
331 for (i = 0; i < wlen * 8; i++)
333 if (bmap[i>>3] & (128 >> (i&7)))
334 length += mDNS_snprintf(buffer+length, (MaxMsg - 1) - length, "%s ", DNSTypeName(type + i));
341 // Parse the fields beyond the base header. NSEC3 should have been validated.
342 mDNSexport void NSEC3Parse(const ResourceRecord *const rr, mDNSu8 **salt, int *hashLength, mDNSu8 **nxtName, int *bitmaplen, mDNSu8 **bitmap)
344 const RDataBody2 *const rdb = (RDataBody2 *)rr->rdata->u.data;
345 rdataNSEC3 *nsec3 = (rdataNSEC3 *)rdb->data;
346 mDNSu8 *p = (mDNSu8 *)&nsec3->salt;
351 if (nsec3->saltLength)
356 p += nsec3->saltLength;
357 // p is pointing at hashLength
366 *bitmaplen = rr->rdlength - (int)(p - rdb->data);
371 // Note slight bug: this code uses the rdlength from the ResourceRecord object, to display
372 // the rdata from the RDataBody object. Sometimes this could be the wrong length -- but as
373 // long as this routine is only used for debugging messages, it probably isn't a big problem.
374 mDNSexport char *GetRRDisplayString_rdb(const ResourceRecord *const rr, const RDataBody *const rd1, char *const buffer)
376 const RDataBody2 *const rd = (RDataBody2 *)rd1;
377 #define RemSpc (MaxMsg-1-length)
379 mDNSu32 length = mDNS_snprintf(buffer, MaxMsg-1, "%4d %##s %s ", rr->rdlength, rr->name->c, DNSTypeName(rr->rrtype));
380 if (rr->RecordType == kDNSRecordTypePacketNegative) return(buffer);
381 if (!rr->rdlength && rr->rrtype != kDNSType_OPT) { mDNS_snprintf(buffer+length, RemSpc, "<< ZERO RDATA LENGTH >>"); return(buffer); }
385 case kDNSType_A: mDNS_snprintf(buffer+length, RemSpc, "%.4a", &rd->ipv4); break;
387 case kDNSType_NS: // Same as PTR
388 case kDNSType_CNAME: // Same as PTR
389 case kDNSType_PTR: mDNS_snprintf(buffer+length, RemSpc, "%##s", rd->name.c); break;
391 case kDNSType_SOA: mDNS_snprintf(buffer+length, RemSpc, "%##s %##s %d %d %d %d %d",
392 rd->soa.mname.c, rd->soa.rname.c,
393 rd->soa.serial, rd->soa.refresh, rd->soa.retry, rd->soa.expire, rd->soa.min);
396 case kDNSType_HINFO: // Display this the same as TXT (show all constituent strings)
398 const mDNSu8 *t = rd->txt.c;
399 while (t < rd->txt.c + rr->rdlength)
401 length += mDNS_snprintf(buffer+length, RemSpc, "%s%#s", t > rd->txt.c ? "¦" : "", t);
406 case kDNSType_AAAA: mDNS_snprintf(buffer+length, RemSpc, "%.16a", &rd->ipv6); break;
407 case kDNSType_SRV: mDNS_snprintf(buffer+length, RemSpc, "%u %u %u %##s",
408 rd->srv.priority, rd->srv.weight, mDNSVal16(rd->srv.port), rd->srv.target.c); break;
412 const rdataOPT *const end = (const rdataOPT *)&rd->data[rr->rdlength];
413 length += mDNS_snprintf(buffer+length, RemSpc, "Max %d", rr->rrclass);
414 for (opt = &rd->opt[0]; opt < end; opt++)
419 length += mDNS_snprintf(buffer+length, RemSpc, " LLQ");
420 length += mDNS_snprintf(buffer+length, RemSpc, " Vers %d", opt->u.llq.vers);
421 length += mDNS_snprintf(buffer+length, RemSpc, " Op %d", opt->u.llq.llqOp);
422 length += mDNS_snprintf(buffer+length, RemSpc, " Err/Port %d", opt->u.llq.err);
423 length += mDNS_snprintf(buffer+length, RemSpc, " ID %08X%08X", opt->u.llq.id.l[0], opt->u.llq.id.l[1]);
424 length += mDNS_snprintf(buffer+length, RemSpc, " Lease %d", opt->u.llq.llqlease);
427 length += mDNS_snprintf(buffer+length, RemSpc, " Lease %d", opt->u.updatelease);
430 length += mDNS_snprintf(buffer+length, RemSpc, " Owner");
431 length += mDNS_snprintf(buffer+length, RemSpc, " Vers %d", opt->u.owner.vers);
432 length += mDNS_snprintf(buffer+length, RemSpc, " Seq %3d", (mDNSu8)opt->u.owner.seq); // Display as unsigned
433 length += mDNS_snprintf(buffer+length, RemSpc, " MAC %.6a", opt->u.owner.HMAC.b);
434 if (opt->optlen >= DNSOpt_OwnerData_ID_Wake_Space-4)
436 length += mDNS_snprintf(buffer+length, RemSpc, " I-MAC %.6a", opt->u.owner.IMAC.b);
437 if (opt->optlen > DNSOpt_OwnerData_ID_Wake_Space-4)
438 length += mDNS_snprintf(buffer+length, RemSpc, " Password %.6a", opt->u.owner.password.b);
442 length += mDNS_snprintf(buffer+length, RemSpc, " Trace");
443 length += mDNS_snprintf(buffer+length, RemSpc, " Platform %d", opt->u.tracer.platf);
444 length += mDNS_snprintf(buffer+length, RemSpc, " mDNSVers %d", opt->u.tracer.mDNSv);
447 length += mDNS_snprintf(buffer+length, RemSpc, " Unknown %d", opt->opt);
454 case kDNSType_NSEC: {
455 domainname *next = (domainname *)rd->data;
458 len = DomainNameLength(next);
459 bitmaplen = rr->rdlength - len;
460 bmap = (mDNSu8 *)((mDNSu8 *)next + len);
462 if (UNICAST_NSEC(rr))
463 length += mDNS_snprintf(buffer+length, RemSpc, "%##s ", next->c);
464 PrintTypeBitmap(bmap, bitmaplen, buffer, length);
468 case kDNSType_NSEC3: {
469 rdataNSEC3 *nsec3 = (rdataNSEC3 *)rd->data;
470 const mDNSu8 *p = (mDNSu8 *)&nsec3->salt;
471 int hashLength, bitmaplen, i;
473 length += mDNS_snprintf(buffer+length, RemSpc, "\t%s %d %d ",
474 DNSSECDigestName(nsec3->alg), nsec3->flags, swap16(nsec3->iterations));
476 if (!nsec3->saltLength)
478 length += mDNS_snprintf(buffer+length, RemSpc, "-");
482 for (i = 0; i < nsec3->saltLength; i++)
484 length += mDNS_snprintf(buffer+length, RemSpc, "%x", p[i]);
488 // put a space at the end
489 length += mDNS_snprintf(buffer+length, RemSpc, " ");
491 p += nsec3->saltLength;
492 // p is pointing at hashLength
493 hashLength = (int)*p++;
495 length += baseEncode(buffer + length, RemSpc, p, hashLength, ENC_BASE32);
497 // put a space at the end
498 length += mDNS_snprintf(buffer+length, RemSpc, " ");
501 bitmaplen = rr->rdlength - (int)(p - rd->data);
502 PrintTypeBitmap(p, bitmaplen, buffer, length);
505 case kDNSType_RRSIG: {
506 rdataRRSig *rrsig = (rdataRRSig *)rd->data;
507 mDNSu8 expTimeBuf[64];
508 mDNSu8 inceptTimeBuf[64];
509 unsigned long inceptClock;
510 unsigned long expClock;
513 expClock = (unsigned long)swap32(rrsig->sigExpireTime);
514 mDNSPlatformFormatTime(expClock, expTimeBuf, sizeof(expTimeBuf));
516 inceptClock = (unsigned long)swap32(rrsig->sigInceptTime);
517 mDNSPlatformFormatTime(inceptClock, inceptTimeBuf, sizeof(inceptTimeBuf));
519 length += mDNS_snprintf(buffer+length, RemSpc, "\t%s %s %d %d %s %s %d %##s ",
520 DNSTypeName(swap16(rrsig->typeCovered)), DNSSECAlgName(rrsig->alg), rrsig->labels, swap32(rrsig->origTTL),
521 expTimeBuf, inceptTimeBuf, swap16(rrsig->keyTag), rrsig->signerName);
523 len = DomainNameLength((domainname *)&rrsig->signerName);
524 baseEncode(buffer + length, RemSpc, (const mDNSu8 *)(rd->data + len + RRSIG_FIXED_SIZE),
525 rr->rdlength - (len + RRSIG_FIXED_SIZE), ENC_BASE64);
528 case kDNSType_DNSKEY: {
529 rdataDNSKey *rrkey = (rdataDNSKey *)rd->data;
530 length += mDNS_snprintf(buffer+length, RemSpc, "\t%d %d %s %u ", swap16(rrkey->flags), rrkey->proto,
531 DNSSECAlgName(rrkey->alg), (unsigned int)keytag((mDNSu8 *)rrkey, rr->rdlength));
532 baseEncode(buffer + length, RemSpc, (const mDNSu8 *)(rd->data + DNSKEY_FIXED_SIZE),
533 rr->rdlength - DNSKEY_FIXED_SIZE, ENC_BASE64);
539 rdataDS *rrds = (rdataDS *)rd->data;
541 length += mDNS_snprintf(buffer+length, RemSpc, "\t%s\t%d\t%s ", DNSSECAlgName(rrds->alg), swap16(rrds->keyTag),
542 DNSSECDigestName(rrds->digestType));
544 p = (mDNSu8 *)(rd->data + DS_FIXED_SIZE);
545 for (i = 0; i < (rr->rdlength - DS_FIXED_SIZE); i++)
547 length += mDNS_snprintf(buffer+length, RemSpc, "%x", p[i]);
552 default: mDNS_snprintf(buffer+length, RemSpc, "RDLen %d: %.*s", rr->rdlength, rr->rdlength, rd->data);
553 // Really should scan buffer to check if text is valid UTF-8 and only replace with dots if not
554 for (ptr = buffer; *ptr; ptr++) if (*ptr < ' ') *ptr = '.';
560 // See comments in mDNSEmbeddedAPI.h
561 #if _PLATFORM_HAS_STRONG_PRNG_
562 #define mDNSRandomNumber mDNSPlatformRandomNumber
564 mDNSlocal mDNSu32 mDNSRandomFromSeed(mDNSu32 seed)
566 return seed * 21 + 1;
569 mDNSlocal mDNSu32 mDNSMixRandomSeed(mDNSu32 seed, mDNSu8 iteration)
571 return iteration ? mDNSMixRandomSeed(mDNSRandomFromSeed(seed), --iteration) : seed;
574 mDNSlocal mDNSu32 mDNSRandomNumber()
576 static mDNSBool seeded = mDNSfalse;
577 static mDNSu32 seed = 0;
580 seed = mDNSMixRandomSeed(mDNSPlatformRandomSeed(), 100);
583 return (seed = mDNSRandomFromSeed(seed));
585 #endif // ! _PLATFORM_HAS_STRONG_PRNG_
587 mDNSexport mDNSu32 mDNSRandom(mDNSu32 max) // Returns pseudo-random result from zero to max inclusive
592 while (mask < max) mask = (mask << 1) | 1;
594 do ret = mDNSRandomNumber() & mask;
600 mDNSexport mDNSBool mDNSSameAddress(const mDNSAddr *ip1, const mDNSAddr *ip2)
602 if (ip1->type == ip2->type)
606 case mDNSAddrType_None: return(mDNStrue); // Empty addresses have no data and are therefore always equal
607 case mDNSAddrType_IPv4: return (mDNSBool)(mDNSSameIPv4Address(ip1->ip.v4, ip2->ip.v4));
608 case mDNSAddrType_IPv6: return (mDNSBool)(mDNSSameIPv6Address(ip1->ip.v6, ip2->ip.v6));
614 mDNSexport mDNSBool mDNSAddrIsDNSMulticast(const mDNSAddr *ip)
618 case mDNSAddrType_IPv4: return (mDNSBool)(mDNSSameIPv4Address(ip->ip.v4, AllDNSLinkGroup_v4.ip.v4));
619 case mDNSAddrType_IPv6: return (mDNSBool)(mDNSSameIPv6Address(ip->ip.v6, AllDNSLinkGroup_v6.ip.v6));
620 default: return(mDNSfalse);
624 // ***************************************************************************
625 #if COMPILER_LIKES_PRAGMA_MARK
627 #pragma mark - Domain Name Utility Functions
630 #if !APPLE_OSX_mDNSResponder
632 mDNSexport mDNSBool SameDomainLabel(const mDNSu8 *a, const mDNSu8 *b)
635 const int len = *a++;
637 if (len > MAX_DOMAIN_LABEL)
638 { debugf("Malformed label (too long)"); return(mDNSfalse); }
640 if (len != *b++) return(mDNSfalse);
641 for (i=0; i<len; i++)
645 if (mDNSIsUpperCase(ac)) ac += 'a' - 'A';
646 if (mDNSIsUpperCase(bc)) bc += 'a' - 'A';
647 if (ac != bc) return(mDNSfalse);
652 #endif // !APPLE_OSX_mDNSResponder
654 mDNSexport mDNSBool SameDomainName(const domainname *const d1, const domainname *const d2)
656 const mDNSu8 * a = d1->c;
657 const mDNSu8 * b = d2->c;
658 const mDNSu8 *const max = d1->c + MAX_DOMAIN_NAME; // Maximum that's valid
662 if (a + 1 + *a >= max)
663 { debugf("Malformed domain name (more than 256 characters)"); return(mDNSfalse); }
664 if (!SameDomainLabel(a, b)) return(mDNSfalse);
672 mDNSexport mDNSBool SameDomainNameCS(const domainname *const d1, const domainname *const d2)
674 mDNSu16 l1 = DomainNameLength(d1);
675 mDNSu16 l2 = DomainNameLength(d2);
676 return(l1 <= MAX_DOMAIN_NAME && l1 == l2 && mDNSPlatformMemSame(d1, d2, l1));
679 mDNSexport mDNSBool IsLocalDomain(const domainname *d)
681 // Domains that are defined to be resolved via link-local multicast are:
682 // local., 254.169.in-addr.arpa., and {8,9,A,B}.E.F.ip6.arpa.
683 static const domainname *nL = (const domainname*)"\x5" "local";
684 static const domainname *nR = (const domainname*)"\x3" "254" "\x3" "169" "\x7" "in-addr" "\x4" "arpa";
685 static const domainname *n8 = (const domainname*)"\x1" "8" "\x1" "e" "\x1" "f" "\x3" "ip6" "\x4" "arpa";
686 static const domainname *n9 = (const domainname*)"\x1" "9" "\x1" "e" "\x1" "f" "\x3" "ip6" "\x4" "arpa";
687 static const domainname *nA = (const domainname*)"\x1" "a" "\x1" "e" "\x1" "f" "\x3" "ip6" "\x4" "arpa";
688 static const domainname *nB = (const domainname*)"\x1" "b" "\x1" "e" "\x1" "f" "\x3" "ip6" "\x4" "arpa";
690 const domainname *d1, *d2, *d3, *d4, *d5; // Top-level domain, second-level domain, etc.
691 d1 = d2 = d3 = d4 = d5 = mDNSNULL;
694 d5 = d4; d4 = d3; d3 = d2; d2 = d1; d1 = d;
695 d = (const domainname*)(d->c + 1 + d->c[0]);
698 if (d1 && SameDomainName(d1, nL)) return(mDNStrue);
699 if (d4 && SameDomainName(d4, nR)) return(mDNStrue);
700 if (d5 && SameDomainName(d5, n8)) return(mDNStrue);
701 if (d5 && SameDomainName(d5, n9)) return(mDNStrue);
702 if (d5 && SameDomainName(d5, nA)) return(mDNStrue);
703 if (d5 && SameDomainName(d5, nB)) return(mDNStrue);
707 mDNSexport const mDNSu8 *LastLabel(const domainname *d)
709 const mDNSu8 *p = d->c;
713 d = (const domainname*)(d->c + 1 + d->c[0]);
718 // Returns length of a domain name INCLUDING the byte for the final null label
719 // e.g. for the root label "." it returns one
720 // For the FQDN "com." it returns 5 (length byte, three data bytes, final zero)
721 // Legal results are 1 (just root label) to 256 (MAX_DOMAIN_NAME)
722 // If the given domainname is invalid, result is 257 (MAX_DOMAIN_NAME+1)
723 mDNSexport mDNSu16 DomainNameLengthLimit(const domainname *const name, const mDNSu8 *limit)
725 const mDNSu8 *src = name->c;
726 while (src < limit && *src <= MAX_DOMAIN_LABEL)
728 if (*src == 0) return((mDNSu16)(src - name->c + 1));
731 return(MAX_DOMAIN_NAME+1);
734 // CompressedDomainNameLength returns the length of a domain name INCLUDING the byte
735 // for the final null label, e.g. for the root label "." it returns one.
736 // E.g. for the FQDN "foo.com." it returns 9
737 // (length, three data bytes, length, three more data bytes, final zero).
738 // In the case where a parent domain name is provided, and the given name is a child
739 // of that parent, CompressedDomainNameLength returns the length of the prefix portion
740 // of the child name, plus TWO bytes for the compression pointer.
741 // E.g. for the name "foo.com." with parent "com.", it returns 6
742 // (length, three data bytes, two-byte compression pointer).
743 mDNSexport mDNSu16 CompressedDomainNameLength(const domainname *const name, const domainname *parent)
745 const mDNSu8 *src = name->c;
746 if (parent && parent->c[0] == 0) parent = mDNSNULL;
749 if (*src > MAX_DOMAIN_LABEL) return(MAX_DOMAIN_NAME+1);
750 if (parent && SameDomainName((const domainname *)src, parent)) return((mDNSu16)(src - name->c + 2));
752 if (src - name->c >= MAX_DOMAIN_NAME) return(MAX_DOMAIN_NAME+1);
754 return((mDNSu16)(src - name->c + 1));
757 // CountLabels() returns number of labels in name, excluding final root label
758 // (e.g. for "apple.com." CountLabels returns 2.)
759 mDNSexport int CountLabels(const domainname *d)
763 for (ptr = d->c; *ptr; ptr = ptr + ptr[0] + 1) count++;
767 // SkipLeadingLabels skips over the first 'skip' labels in the domainname,
768 // returning a pointer to the suffix with 'skip' labels removed.
769 mDNSexport const domainname *SkipLeadingLabels(const domainname *d, int skip)
771 while (skip > 0 && d->c[0]) { d = (const domainname *)(d->c + 1 + d->c[0]); skip--; }
775 // AppendLiteralLabelString appends a single label to an existing (possibly empty) domainname.
776 // The C string contains the label as-is, with no escaping, etc.
777 // Any dots in the name are literal dots, not label separators
778 // If successful, AppendLiteralLabelString returns a pointer to the next unused byte
779 // in the domainname bufer (i.e. the next byte after the terminating zero).
780 // If unable to construct a legal domain name (i.e. label more than 63 bytes, or total more than 256 bytes)
781 // AppendLiteralLabelString returns mDNSNULL.
782 mDNSexport mDNSu8 *AppendLiteralLabelString(domainname *const name, const char *cstr)
784 mDNSu8 * ptr = name->c + DomainNameLength(name) - 1; // Find end of current name
785 const mDNSu8 *const lim1 = name->c + MAX_DOMAIN_NAME - 1; // Limit of how much we can add (not counting final zero)
786 const mDNSu8 *const lim2 = ptr + 1 + MAX_DOMAIN_LABEL;
787 const mDNSu8 *const lim = (lim1 < lim2) ? lim1 : lim2;
788 mDNSu8 *lengthbyte = ptr++; // Record where the length is going to go
790 while (*cstr && ptr < lim) *ptr++ = (mDNSu8)*cstr++; // Copy the data
791 *lengthbyte = (mDNSu8)(ptr - lengthbyte - 1); // Fill in the length byte
792 *ptr++ = 0; // Put the null root label on the end
793 if (*cstr) return(mDNSNULL); // Failure: We didn't successfully consume all input
794 else return(ptr); // Success: return new value of ptr
797 // AppendDNSNameString appends zero or more labels to an existing (possibly empty) domainname.
798 // The C string is in conventional DNS syntax:
799 // Textual labels, escaped as necessary using the usual DNS '\' notation, separated by dots.
800 // If successful, AppendDNSNameString returns a pointer to the next unused byte
801 // in the domainname bufer (i.e. the next byte after the terminating zero).
802 // If unable to construct a legal domain name (i.e. label more than 63 bytes, or total more than 256 bytes)
803 // AppendDNSNameString returns mDNSNULL.
804 mDNSexport mDNSu8 *AppendDNSNameString(domainname *const name, const char *cstring)
806 const char *cstr = cstring;
807 mDNSu8 * ptr = name->c + DomainNameLength(name) - 1; // Find end of current name
808 const mDNSu8 *const lim = name->c + MAX_DOMAIN_NAME - 1; // Limit of how much we can add (not counting final zero)
809 while (*cstr && ptr < lim) // While more characters, and space to put them...
811 mDNSu8 *lengthbyte = ptr++; // Record where the length is going to go
812 if (*cstr == '.') { LogMsg("AppendDNSNameString: Illegal empty label in name \"%s\"", cstring); return(mDNSNULL); }
813 while (*cstr && *cstr != '.' && ptr < lim) // While we have characters in the label...
815 mDNSu8 c = (mDNSu8)*cstr++; // Read the character
816 if (c == '\\') // If escape character, check next character
818 if (*cstr == '\0') break; // If this is the end of the string, then break
819 c = (mDNSu8)*cstr++; // Assume we'll just take the next character
820 if (mDNSIsDigit(cstr[-1]) && mDNSIsDigit(cstr[0]) && mDNSIsDigit(cstr[1]))
821 { // If three decimal digits,
822 int v0 = cstr[-1] - '0'; // then interpret as three-digit decimal
823 int v1 = cstr[ 0] - '0';
824 int v2 = cstr[ 1] - '0';
825 int val = v0 * 100 + v1 * 10 + v2;
826 if (val <= 255) { c = (mDNSu8)val; cstr += 2; } // If valid three-digit decimal value, use it
829 *ptr++ = c; // Write the character
831 if (*cstr == '.') cstr++; // Skip over the trailing dot (if present)
832 if (ptr - lengthbyte - 1 > MAX_DOMAIN_LABEL) // If illegal label, abort
834 *lengthbyte = (mDNSu8)(ptr - lengthbyte - 1); // Fill in the length byte
837 *ptr++ = 0; // Put the null root label on the end
838 if (*cstr) return(mDNSNULL); // Failure: We didn't successfully consume all input
839 else return(ptr); // Success: return new value of ptr
842 // AppendDomainLabel appends a single label to a name.
843 // If successful, AppendDomainLabel returns a pointer to the next unused byte
844 // in the domainname bufer (i.e. the next byte after the terminating zero).
845 // If unable to construct a legal domain name (i.e. label more than 63 bytes, or total more than 256 bytes)
846 // AppendDomainLabel returns mDNSNULL.
847 mDNSexport mDNSu8 *AppendDomainLabel(domainname *const name, const domainlabel *const label)
850 mDNSu8 *ptr = name->c + DomainNameLength(name) - 1;
852 // Check label is legal
853 if (label->c[0] > MAX_DOMAIN_LABEL) return(mDNSNULL);
855 // Check that ptr + length byte + data bytes + final zero does not exceed our limit
856 if (ptr + 1 + label->c[0] + 1 > name->c + MAX_DOMAIN_NAME) return(mDNSNULL);
858 for (i=0; i<=label->c[0]; i++) *ptr++ = label->c[i]; // Copy the label data
859 *ptr++ = 0; // Put the null root label on the end
863 mDNSexport mDNSu8 *AppendDomainName(domainname *const name, const domainname *const append)
865 mDNSu8 * ptr = name->c + DomainNameLength(name) - 1; // Find end of current name
866 const mDNSu8 *const lim = name->c + MAX_DOMAIN_NAME - 1; // Limit of how much we can add (not counting final zero)
867 const mDNSu8 * src = append->c;
871 if (ptr + 1 + src[0] > lim) return(mDNSNULL);
872 for (i=0; i<=src[0]; i++) *ptr++ = src[i];
873 *ptr = 0; // Put the null root label on the end
879 // MakeDomainLabelFromLiteralString makes a single domain label from a single literal C string (with no escaping).
880 // If successful, MakeDomainLabelFromLiteralString returns mDNStrue.
881 // If unable to convert the whole string to a legal domain label (i.e. because length is more than 63 bytes) then
882 // MakeDomainLabelFromLiteralString makes a legal domain label from the first 63 bytes of the string and returns mDNSfalse.
883 // In some cases silently truncated oversized names to 63 bytes is acceptable, so the return result may be ignored.
884 // In other cases silent truncation may not be acceptable, so in those cases the calling function needs to check the return result.
885 mDNSexport mDNSBool MakeDomainLabelFromLiteralString(domainlabel *const label, const char *cstr)
887 mDNSu8 * ptr = label->c + 1; // Where we're putting it
888 const mDNSu8 *const limit = label->c + 1 + MAX_DOMAIN_LABEL; // The maximum we can put
889 while (*cstr && ptr < limit) *ptr++ = (mDNSu8)*cstr++; // Copy the label
890 label->c[0] = (mDNSu8)(ptr - label->c - 1); // Set the length byte
891 return(*cstr == 0); // Return mDNStrue if we successfully consumed all input
894 // MakeDomainNameFromDNSNameString makes a native DNS-format domainname from a C string.
895 // The C string is in conventional DNS syntax:
896 // Textual labels, escaped as necessary using the usual DNS '\' notation, separated by dots.
897 // If successful, MakeDomainNameFromDNSNameString returns a pointer to the next unused byte
898 // in the domainname bufer (i.e. the next byte after the terminating zero).
899 // If unable to construct a legal domain name (i.e. label more than 63 bytes, or total more than 256 bytes)
900 // MakeDomainNameFromDNSNameString returns mDNSNULL.
901 mDNSexport mDNSu8 *MakeDomainNameFromDNSNameString(domainname *const name, const char *cstr)
903 name->c[0] = 0; // Make an empty domain name
904 return(AppendDNSNameString(name, cstr)); // And then add this string to it
907 mDNSexport char *ConvertDomainLabelToCString_withescape(const domainlabel *const label, char *ptr, char esc)
909 const mDNSu8 * src = label->c; // Domain label we're reading
910 const mDNSu8 len = *src++; // Read length of this (non-null) label
911 const mDNSu8 *const end = src + len; // Work out where the label ends
912 if (len > MAX_DOMAIN_LABEL) return(mDNSNULL); // If illegal label, abort
913 while (src < end) // While we have characters in the label
918 if (c == '.' || c == esc) // If character is a dot or the escape character
919 *ptr++ = esc; // Output escape character
920 else if (c <= ' ') // If non-printing ascii,
921 { // Output decimal escape sequence
923 *ptr++ = (char) ('0' + (c / 100) );
924 *ptr++ = (char) ('0' + (c / 10) % 10);
925 c = (mDNSu8)('0' + (c ) % 10);
928 *ptr++ = (char)c; // Copy the character
930 *ptr = 0; // Null-terminate the string
931 return(ptr); // and return
934 // Note: To guarantee that there will be no possible overrun, cstr must be at least MAX_ESCAPED_DOMAIN_NAME (1009 bytes)
935 mDNSexport char *ConvertDomainNameToCString_withescape(const domainname *const name, char *ptr, char esc)
937 const mDNSu8 *src = name->c; // Domain name we're reading
938 const mDNSu8 *const max = name->c + MAX_DOMAIN_NAME; // Maximum that's valid
940 if (*src == 0) *ptr++ = '.'; // Special case: For root, just write a dot
942 while (*src) // While more characters in the domain name
944 if (src + 1 + *src >= max) return(mDNSNULL);
945 ptr = ConvertDomainLabelToCString_withescape((const domainlabel *)src, ptr, esc);
946 if (!ptr) return(mDNSNULL);
948 *ptr++ = '.'; // Write the dot after the label
951 *ptr++ = 0; // Null-terminate the string
952 return(ptr); // and return
956 // Host names must start with a letter, end with a letter or digit,
957 // and have as interior characters only letters, digits, and hyphen.
958 // This was subsequently modified in RFC 1123 to allow the first character to be either a letter or a digit
960 mDNSexport void ConvertUTF8PstringToRFC1034HostLabel(const mDNSu8 UTF8Name[], domainlabel *const hostlabel)
962 const mDNSu8 * src = &UTF8Name[1];
963 const mDNSu8 *const end = &UTF8Name[1] + UTF8Name[0];
964 mDNSu8 * ptr = &hostlabel->c[1];
965 const mDNSu8 *const lim = &hostlabel->c[1] + MAX_DOMAIN_LABEL;
968 // Delete apostrophes from source name
969 if (src[0] == '\'') { src++; continue; } // Standard straight single quote
970 if (src + 2 < end && src[0] == 0xE2 && src[1] == 0x80 && src[2] == 0x99)
971 { src += 3; continue; } // Unicode curly apostrophe
974 if (mDNSValidHostChar(*src, (ptr > &hostlabel->c[1]), (src < end-1))) *ptr++ = *src;
975 else if (ptr > &hostlabel->c[1] && ptr[-1] != '-') *ptr++ = '-';
979 while (ptr > &hostlabel->c[1] && ptr[-1] == '-') ptr--; // Truncate trailing '-' marks
980 hostlabel->c[0] = (mDNSu8)(ptr - &hostlabel->c[1]);
983 mDNSexport mDNSu8 *ConstructServiceName(domainname *const fqdn,
984 const domainlabel *name, const domainname *type, const domainname *const domain)
987 mDNSu8 *dst = fqdn->c;
989 const char *errormsg;
990 #if APPLE_OSX_mDNSResponder
991 mDNSBool loggedUnderscore = mDNSfalse;
992 static char typeBuf[MAX_ESCAPED_DOMAIN_NAME];
995 // In the case where there is no name (and ONLY in that case),
996 // a single-label subtype is allowed as the first label of a three-part "type"
999 const mDNSu8 *s0 = type->c;
1000 if (s0[0] && s0[0] < 0x40) // If legal first label (at least one character, and no more than 63)
1002 const mDNSu8 * s1 = s0 + 1 + s0[0];
1003 if (s1[0] && s1[0] < 0x40) // and legal second label (at least one character, and no more than 63)
1005 const mDNSu8 *s2 = s1 + 1 + s1[0];
1006 if (s2[0] && s2[0] < 0x40 && s2[1+s2[0]] == 0) // and we have three and only three labels
1008 static const mDNSu8 SubTypeLabel[5] = mDNSSubTypeLabel;
1009 src = s0; // Copy the first label
1011 for (i=0; i <= len; i++) *dst++ = *src++;
1012 for (i=0; i < (int)sizeof(SubTypeLabel); i++) *dst++ = SubTypeLabel[i];
1013 type = (const domainname *)s1;
1015 // Special support to enable the DNSServiceBrowse call made by Bonjour Browser
1016 // For these queries, we retract the "._sub" we just added between the subtype and the main type
1017 // Remove after Bonjour Browser is updated to use DNSServiceQueryRecord instead of DNSServiceBrowse
1018 if (SameDomainName((domainname*)s0, (const domainname*)"\x09_services\x07_dns-sd\x04_udp"))
1019 dst -= sizeof(SubTypeLabel);
1025 if (name && name->c[0])
1027 src = name->c; // Put the service name into the domain name
1029 if (len >= 0x40) { errormsg = "Service instance name too long"; goto fail; }
1030 for (i=0; i<=len; i++) *dst++ = *src++;
1033 name = (domainlabel*)""; // Set this up to be non-null, to avoid errors if we have to call LogMsg() below
1035 src = type->c; // Put the service type into the domain name
1037 if (len < 2 || len > 16)
1039 LogMsg("Bad service type in %#s.%##s%##s Application protocol name must be underscore plus 1-15 characters. "
1040 "See <http://www.dns-sd.org/ServiceTypes.html>", name->c, type->c, domain->c);
1042 if (len < 2 || len >= 0x40 || (len > 16 && !SameDomainName(domain, &localdomain))) return(mDNSNULL);
1043 if (src[1] != '_') { errormsg = "Application protocol name must begin with underscore"; goto fail; }
1044 for (i=2; i<=len; i++)
1046 // Letters and digits are allowed anywhere
1047 if (mDNSIsLetter(src[i]) || mDNSIsDigit(src[i])) continue;
1048 // Hyphens are only allowed as interior characters
1049 // Underscores are not supposed to be allowed at all, but for backwards compatibility with some old products we do allow them,
1050 // with the same rule as hyphens
1051 if ((src[i] == '-' || src[i] == '_') && i > 2 && i < len)
1053 #if APPLE_OSX_mDNSResponder
1054 if (src[i] == '_' && loggedUnderscore == mDNSfalse)
1056 ConvertDomainNameToCString(type, typeBuf);
1057 LogInfo("ConstructServiceName: Service type with non-leading underscore %s", typeBuf);
1058 loggedUnderscore = mDNStrue;
1063 errormsg = "Application protocol name must contain only letters, digits, and hyphens";
1066 for (i=0; i<=len; i++) *dst++ = *src++;
1069 if (!ValidTransportProtocol(src)) { errormsg = "Transport protocol name must be _udp or _tcp"; goto fail; }
1070 for (i=0; i<=len; i++) *dst++ = *src++;
1072 if (*src) { errormsg = "Service type must have only two labels"; goto fail; }
1075 if (!domain->c[0]) { errormsg = "Service domain must be non-empty"; goto fail; }
1076 if (SameDomainName(domain, (const domainname*)"\x05" "local" "\x04" "arpa"))
1077 { errormsg = "Illegal domain \"local.arpa.\" Use \"local.\" (or empty string)"; goto fail; }
1078 dst = AppendDomainName(fqdn, domain);
1079 if (!dst) { errormsg = "Service domain too long"; goto fail; }
1083 LogMsg("ConstructServiceName: %s: %#s.%##s%##s", errormsg, name->c, type->c, domain->c);
1087 // A service name has the form: instance.application-protocol.transport-protocol.domain
1088 // DeconstructServiceName is currently fairly forgiving: It doesn't try to enforce character
1089 // set or length limits for the protocol names, and the final domain is allowed to be empty.
1090 // However, if the given FQDN doesn't contain at least three labels,
1091 // DeconstructServiceName will reject it and return mDNSfalse.
1092 mDNSexport mDNSBool DeconstructServiceName(const domainname *const fqdn,
1093 domainlabel *const name, domainname *const type, domainname *const domain)
1096 const mDNSu8 *src = fqdn->c;
1097 const mDNSu8 *max = fqdn->c + MAX_DOMAIN_NAME;
1100 dst = name->c; // Extract the service name
1102 if (!len) { debugf("DeconstructServiceName: FQDN empty!"); return(mDNSfalse); }
1103 if (len >= 0x40) { debugf("DeconstructServiceName: Instance name too long"); return(mDNSfalse); }
1104 for (i=0; i<=len; i++) *dst++ = *src++;
1106 dst = type->c; // Extract the service type
1108 if (!len) { debugf("DeconstructServiceName: FQDN contains only one label!"); return(mDNSfalse); }
1109 if (len >= 0x40) { debugf("DeconstructServiceName: Application protocol name too long"); return(mDNSfalse); }
1110 if (src[1] != '_') { debugf("DeconstructServiceName: No _ at start of application protocol"); return(mDNSfalse); }
1111 for (i=0; i<=len; i++) *dst++ = *src++;
1114 if (!len) { debugf("DeconstructServiceName: FQDN contains only two labels!"); return(mDNSfalse); }
1115 if (!ValidTransportProtocol(src))
1116 { debugf("DeconstructServiceName: Transport protocol must be _udp or _tcp"); return(mDNSfalse); }
1117 for (i=0; i<=len; i++) *dst++ = *src++;
1118 *dst++ = 0; // Put terminator on the end of service type
1120 dst = domain->c; // Extract the service domain
1125 { debugf("DeconstructServiceName: Label in service domain too long"); return(mDNSfalse); }
1126 if (src + 1 + len + 1 >= max)
1127 { debugf("DeconstructServiceName: Total service domain too long"); return(mDNSfalse); }
1128 for (i=0; i<=len; i++) *dst++ = *src++;
1130 *dst++ = 0; // Put the null root label on the end
1135 mDNSexport mStatus DNSNameToLowerCase(domainname *d, domainname *result)
1137 const mDNSu8 *a = d->c;
1138 mDNSu8 *b = result->c;
1139 const mDNSu8 *const max = d->c + MAX_DOMAIN_NAME;
1144 if (a + 1 + *a >= max)
1146 LogMsg("DNSNameToLowerCase: ERROR!! Malformed Domain name");
1147 return mStatus_BadParamErr;
1151 for (i = 0; i < len; i++)
1154 if (mDNSIsUpperCase(ac)) ac += 'a' - 'A';
1160 return mStatus_NoError;
1163 mDNSexport const mDNSu8 *NSEC3HashName(const domainname *name, rdataNSEC3 *nsec3, const mDNSu8 *AnonData, int AnonDataLen,
1164 const mDNSu8 hash[NSEC3_MAX_HASH_LEN], int *dlen)
1168 unsigned int iterations;
1170 mDNSu8 *p = (mDNSu8 *)&nsec3->salt;
1171 const mDNSu8 *digest;
1173 mDNSBool first = mDNStrue;
1175 if (DNSNameToLowerCase((domainname *)name, &lname) != mStatus_NoError)
1177 LogMsg("NSEC3HashName: ERROR!! DNSNameToLowerCase failed");
1182 digestlen = DomainNameLength(&lname);
1184 // Note that it is "i <=". The first iteration is for digesting the name and salt.
1185 // The iteration count does not include that.
1186 iterations = swap16(nsec3->iterations);
1187 for (i = 0; i <= iterations; i++)
1189 ctx = AlgCreate(DIGEST_ALG, nsec3->alg);
1192 LogMsg("NSEC3HashName: ERROR!! Cannot allocate context");
1196 AlgAdd(ctx, digest, digestlen);
1197 if (nsec3->saltLength)
1198 AlgAdd(ctx, p, nsec3->saltLength);
1200 AlgAdd(ctx, AnonData, AnonDataLen);
1205 digestlen = AlgLength(ctx);
1207 AlgFinal(ctx, (void *)digest, digestlen);
1215 // 0xxxxxxx represents a 7-bit ASCII value from 0x00 to 0x7F
1216 // 10xxxxxx is a continuation byte of a multi-byte character
1217 // 110xxxxx is the first byte of a 2-byte character (11 effective bits; values 0x 80 - 0x 800-1)
1218 // 1110xxxx is the first byte of a 3-byte character (16 effective bits; values 0x 800 - 0x 10000-1)
1219 // 11110xxx is the first byte of a 4-byte character (21 effective bits; values 0x 10000 - 0x 200000-1)
1220 // 111110xx is the first byte of a 5-byte character (26 effective bits; values 0x 200000 - 0x 4000000-1)
1221 // 1111110x is the first byte of a 6-byte character (31 effective bits; values 0x4000000 - 0x80000000-1)
1223 // UTF-16 surrogate pairs are used in UTF-16 to encode values larger than 0xFFFF.
1224 // Although UTF-16 surrogate pairs are not supposed to appear in legal UTF-8, we want to be defensive
1225 // about that too. (See <http://www.unicode.org/faq/utf_bom.html#34>, "What are surrogates?")
1226 // The first of pair is a UTF-16 value in the range 0xD800-0xDBFF (11101101 1010xxxx 10xxxxxx in UTF-8),
1227 // and the second is a UTF-16 value in the range 0xDC00-0xDFFF (11101101 1011xxxx 10xxxxxx in UTF-8).
1229 mDNSexport mDNSu32 TruncateUTF8ToLength(mDNSu8 *string, mDNSu32 length, mDNSu32 max)
1233 mDNSu8 c1 = string[max]; // First byte after cut point
1234 mDNSu8 c2 = (max+1 < length) ? string[max+1] : (mDNSu8)0xB0; // Second byte after cut point
1235 length = max; // Trim length down
1238 // Check if the byte right after the chop point is a UTF-8 continuation byte,
1239 // or if the character right after the chop point is the second of a UTF-16 surrogate pair.
1240 // If so, then we continue to chop more bytes until we get to a legal chop point.
1241 mDNSBool continuation = ((c1 & 0xC0) == 0x80);
1242 mDNSBool secondsurrogate = (c1 == 0xED && (c2 & 0xF0) == 0xB0);
1243 if (!continuation && !secondsurrogate) break;
1245 c1 = string[--length];
1247 // Having truncated characters off the end of our string, also cut off any residual white space
1248 while (length > 0 && string[length-1] <= ' ') length--;
1253 // Returns true if a rich text label ends in " (nnn)", or if an RFC 1034
1254 // name ends in "-nnn", where n is some decimal number.
1255 mDNSexport mDNSBool LabelContainsSuffix(const domainlabel *const name, const mDNSBool RichText)
1257 mDNSu16 l = name->c[0];
1261 if (l < 4) return mDNSfalse; // Need at least " (2)"
1262 if (name->c[l--] != ')') return mDNSfalse; // Last char must be ')'
1263 if (!mDNSIsDigit(name->c[l])) return mDNSfalse; // Preceeded by a digit
1265 while (l > 2 && mDNSIsDigit(name->c[l])) l--; // Strip off digits
1266 return (name->c[l] == '(' && name->c[l - 1] == ' ');
1270 if (l < 2) return mDNSfalse; // Need at least "-2"
1271 if (!mDNSIsDigit(name->c[l])) return mDNSfalse; // Last char must be a digit
1273 while (l > 2 && mDNSIsDigit(name->c[l])) l--; // Strip off digits
1274 return (name->c[l] == '-');
1278 // removes an auto-generated suffix (appended on a name collision) from a label. caller is
1279 // responsible for ensuring that the label does indeed contain a suffix. returns the number
1280 // from the suffix that was removed.
1281 mDNSexport mDNSu32 RemoveLabelSuffix(domainlabel *name, mDNSBool RichText)
1283 mDNSu32 val = 0, multiplier = 1;
1285 // Chop closing parentheses from RichText suffix
1286 if (RichText && name->c[0] >= 1 && name->c[name->c[0]] == ')') name->c[0]--;
1288 // Get any existing numerical suffix off the name
1289 while (mDNSIsDigit(name->c[name->c[0]]))
1290 { val += (name->c[name->c[0]] - '0') * multiplier; multiplier *= 10; name->c[0]--; }
1292 // Chop opening parentheses or dash from suffix
1295 if (name->c[0] >= 2 && name->c[name->c[0]] == '(' && name->c[name->c[0]-1] == ' ') name->c[0] -= 2;
1299 if (name->c[0] >= 1 && name->c[name->c[0]] == '-') name->c[0] -= 1;
1305 // appends a numerical suffix to a label, with the number following a whitespace and enclosed
1306 // in parentheses (rich text) or following two consecutive hyphens (RFC 1034 domain label).
1307 mDNSexport void AppendLabelSuffix(domainlabel *const name, mDNSu32 val, const mDNSBool RichText)
1309 mDNSu32 divisor = 1, chars = 2; // Shortest possible RFC1034 name suffix is 2 characters ("-2")
1310 if (RichText) chars = 4; // Shortest possible RichText suffix is 4 characters (" (2)")
1312 // Truncate trailing spaces from RichText names
1313 if (RichText) while (name->c[name->c[0]] == ' ') name->c[0]--;
1315 while (divisor < 0xFFFFFFFFUL/10 && val >= divisor * 10) { divisor *= 10; chars++; }
1317 name->c[0] = (mDNSu8) TruncateUTF8ToLength(name->c+1, name->c[0], MAX_DOMAIN_LABEL - chars);
1319 if (RichText) { name->c[++name->c[0]] = ' '; name->c[++name->c[0]] = '('; }
1320 else { name->c[++name->c[0]] = '-'; }
1324 name->c[++name->c[0]] = (mDNSu8)('0' + val / divisor);
1329 if (RichText) name->c[++name->c[0]] = ')';
1332 mDNSexport void IncrementLabelSuffix(domainlabel *name, mDNSBool RichText)
1336 if (LabelContainsSuffix(name, RichText))
1337 val = RemoveLabelSuffix(name, RichText);
1339 // If no existing suffix, start by renaming "Foo" as "Foo (2)" or "Foo-2" as appropriate.
1340 // If existing suffix in the range 2-9, increment it.
1341 // If we've had ten conflicts already, there are probably too many hosts trying to use the same name,
1342 // so add a random increment to improve the chances of finding an available name next time.
1343 if (val == 0) val = 2;
1344 else if (val < 10) val++;
1345 else val += 1 + mDNSRandom(99);
1347 AppendLabelSuffix(name, val, RichText);
1350 // ***************************************************************************
1351 #if COMPILER_LIKES_PRAGMA_MARK
1353 #pragma mark - Resource Record Utility Functions
1356 // Set up a AuthRecord with sensible default values.
1357 // These defaults may be overwritten with new values before mDNS_Register is called
1358 mDNSexport void mDNS_SetupResourceRecord(AuthRecord *rr, RData *RDataStorage, mDNSInterfaceID InterfaceID,
1359 mDNSu16 rrtype, mDNSu32 ttl, mDNSu8 RecordType, AuthRecType artype, mDNSRecordCallback Callback, void *Context)
1362 // LocalOnly auth record can be created with LocalOnly InterfaceID or a valid InterfaceID.
1363 // Most of the applications normally create with LocalOnly InterfaceID and we store them as
1364 // such, so that we can deliver the response to questions that specify LocalOnly InterfaceID.
1365 // LocalOnly resource records can also be created with valid InterfaceID which happens today
1366 // when we create LocalOnly records for /etc/hosts.
1368 if (InterfaceID == mDNSInterface_LocalOnly && artype != AuthRecordLocalOnly)
1370 LogMsg("mDNS_SetupResourceRecord: ERROR!! Mismatch LocalOnly record InterfaceID %p called with artype %d", InterfaceID, artype);
1372 else if (InterfaceID == mDNSInterface_P2P && artype != AuthRecordP2P)
1374 LogMsg("mDNS_SetupResourceRecord: ERROR!! Mismatch P2P record InterfaceID %p called with artype %d", InterfaceID, artype);
1376 else if (!InterfaceID && (artype == AuthRecordP2P || artype == AuthRecordLocalOnly))
1378 LogMsg("mDNS_SetupResourceRecord: ERROR!! Mismatch InterfaceAny record InterfaceID %p called with artype %d", InterfaceID, artype);
1381 // Don't try to store a TTL bigger than we can represent in platform time units
1382 if (ttl > 0x7FFFFFFFUL / mDNSPlatformOneSecond)
1383 ttl = 0x7FFFFFFFUL / mDNSPlatformOneSecond;
1384 else if (ttl == 0) // And Zero TTL is illegal
1385 ttl = DefaultTTLforRRType(rrtype);
1387 // Field Group 1: The actual information pertaining to this resource record
1388 rr->resrec.RecordType = RecordType;
1389 rr->resrec.InterfaceID = InterfaceID;
1390 rr->resrec.name = &rr->namestorage;
1391 rr->resrec.rrtype = rrtype;
1392 rr->resrec.rrclass = kDNSClass_IN;
1393 rr->resrec.rroriginalttl = ttl;
1394 rr->resrec.rDNSServer = mDNSNULL;
1395 rr->resrec.AnonInfo = mDNSNULL;
1396 // rr->resrec.rdlength = MUST set by client and/or in mDNS_Register_internal
1397 // rr->resrec.rdestimate = set in mDNS_Register_internal
1398 // rr->resrec.rdata = MUST be set by client
1401 rr->resrec.rdata = RDataStorage;
1404 rr->resrec.rdata = &rr->rdatastorage;
1405 rr->resrec.rdata->MaxRDLength = sizeof(RDataBody);
1408 // Field Group 2: Persistent metadata for Authoritative Records
1409 rr->Additional1 = mDNSNULL;
1410 rr->Additional2 = mDNSNULL;
1411 rr->DependentOn = mDNSNULL;
1412 rr->RRSet = mDNSNULL;
1413 rr->RecordCallback = Callback;
1414 rr->RecordContext = Context;
1416 rr->AutoTarget = Target_Manual;
1417 rr->AllowRemoteQuery = mDNSfalse;
1418 rr->ForceMCast = mDNSfalse;
1420 rr->WakeUp = zeroOwner;
1421 rr->AddressProxy = zeroAddr;
1424 rr->ARType = artype;
1427 // Field Group 3: Transient state for Authoritative Records (set in mDNS_Register_internal)
1428 // Field Group 4: Transient uDNS state for Authoritative Records (set in mDNS_Register_internal)
1430 // For now, until the uDNS code is fully integrated, it's helpful to zero the uDNS state fields here too, just in case
1431 // (e.g. uDNS_RegisterService short-circuits the usual mDNS_Register_internal record registration calls, so a bunch
1432 // of fields don't get set up properly. In particular, if we don't zero rr->QueuedRData then the uDNS code crashes.)
1433 rr->state = regState_Zero;
1437 rr->updateid = zeroID;
1438 rr->zone = rr->resrec.name;
1443 rr->InFlightRData = 0;
1444 rr->InFlightRDLen = 0;
1445 rr->QueuedRData = 0;
1446 rr->QueuedRDLen = 0;
1447 mDNSPlatformMemZero(&rr->NATinfo, sizeof(rr->NATinfo));
1448 rr->SRVChanged = mDNSfalse;
1449 rr->mState = mergeState_Zero;
1451 rr->namestorage.c[0] = 0; // MUST be set by client before calling mDNS_Register()
1454 mDNSexport void mDNS_SetupQuestion(DNSQuestion *const q, const mDNSInterfaceID InterfaceID, const domainname *const name,
1455 const mDNSu16 qtype, mDNSQuestionCallback *const callback, void *const context)
1457 q->InterfaceID = InterfaceID;
1459 q->Target = zeroAddr;
1460 AssignDomainName(&q->qname, name);
1462 q->qclass = kDNSClass_IN;
1463 q->LongLived = (qtype == kDNSType_PTR);
1464 q->ExpectUnique = (qtype != kDNSType_PTR);
1465 q->ForceMCast = mDNSfalse;
1466 q->ReturnIntermed = mDNSfalse;
1467 q->SuppressUnusable = mDNSfalse;
1468 q->SearchListIndex = 0;
1469 q->AppendSearchDomains = 0;
1470 q->RetryWithSearchDomains = mDNSfalse;
1471 q->TimeoutQuestion = 0;
1472 q->WakeOnResolve = 0;
1473 q->UseBackgroundTrafficClass = mDNSfalse;
1474 q->ValidationRequired = 0;
1475 q->ValidatingResponse = 0;
1476 q->ProxyQuestion = 0;
1477 q->qnameOrig = mDNSNULL;
1478 q->AnonInfo = mDNSNULL;
1479 q->pid = mDNSPlatformGetPID();
1481 q->DisallowPID = mDNSfalse;
1483 q->QuestionCallback = callback;
1484 q->QuestionContext = context;
1487 mDNSexport mDNSu32 RDataHashValue(const ResourceRecord *const rr)
1489 int len = rr->rdlength;
1490 const RDataBody2 *const rdb = (RDataBody2 *)rr->rdata->u.data;
1491 const mDNSu8 *ptr = rdb->data;
1499 case kDNSType_CNAME:
1504 case kDNSType_NSAP_PTR:
1505 case kDNSType_DNAME: return DomainNameHashValue(&rdb->name);
1507 case kDNSType_SOA: return rdb->soa.serial +
1512 DomainNameHashValue(&rdb->soa.mname) +
1513 DomainNameHashValue(&rdb->soa.rname);
1516 case kDNSType_AFSDB:
1518 case kDNSType_KX: return DomainNameHashValue(&rdb->mx.exchange);
1520 case kDNSType_MINFO:
1521 case kDNSType_RP: return DomainNameHashValue(&rdb->rp.mbox) + DomainNameHashValue(&rdb->rp.txt);
1523 case kDNSType_PX: return DomainNameHashValue(&rdb->px.map822) + DomainNameHashValue(&rdb->px.mapx400);
1525 case kDNSType_SRV: return DomainNameHashValue(&rdb->srv.target);
1527 case kDNSType_OPT: return 0; // OPT is a pseudo-RR container structure; makes no sense to compare
1529 case kDNSType_NSEC: {
1531 dlen = DomainNameLength((domainname *)rdb->data);
1532 sum = DomainNameHashValue((domainname *)rdb->data);
1541 for (i=0; i+1 < len; i+=2)
1543 sum += (((mDNSu32)(ptr[i])) << 8) | ptr[i+1];
1544 sum = (sum<<3) | (sum>>29);
1548 sum += ((mDNSu32)(ptr[i])) << 8;
1555 // r1 has to be a full ResourceRecord including rrtype and rdlength
1556 // r2 is just a bare RDataBody, which MUST be the same rrtype and rdlength as r1
1557 mDNSexport mDNSBool SameRDataBody(const ResourceRecord *const r1, const RDataBody *const r2, DomainNameComparisonFn *samename)
1559 const RDataBody2 *const b1 = (RDataBody2 *)r1->rdata->u.data;
1560 const RDataBody2 *const b2 = (RDataBody2 *)r2;
1566 case kDNSType_CNAME:
1571 case kDNSType_NSAP_PTR:
1572 case kDNSType_DNAME: return(SameDomainName(&b1->name, &b2->name));
1574 case kDNSType_SOA: return (mDNSBool)( b1->soa.serial == b2->soa.serial &&
1575 b1->soa.refresh == b2->soa.refresh &&
1576 b1->soa.retry == b2->soa.retry &&
1577 b1->soa.expire == b2->soa.expire &&
1578 b1->soa.min == b2->soa.min &&
1579 samename(&b1->soa.mname, &b2->soa.mname) &&
1580 samename(&b1->soa.rname, &b2->soa.rname));
1583 case kDNSType_AFSDB:
1585 case kDNSType_KX: return (mDNSBool)( b1->mx.preference == b2->mx.preference &&
1586 samename(&b1->mx.exchange, &b2->mx.exchange));
1588 case kDNSType_MINFO:
1589 case kDNSType_RP: return (mDNSBool)( samename(&b1->rp.mbox, &b2->rp.mbox) &&
1590 samename(&b1->rp.txt, &b2->rp.txt));
1592 case kDNSType_PX: return (mDNSBool)( b1->px.preference == b2->px.preference &&
1593 samename(&b1->px.map822, &b2->px.map822) &&
1594 samename(&b1->px.mapx400, &b2->px.mapx400));
1596 case kDNSType_SRV: return (mDNSBool)( b1->srv.priority == b2->srv.priority &&
1597 b1->srv.weight == b2->srv.weight &&
1598 mDNSSameIPPort(b1->srv.port, b2->srv.port) &&
1599 samename(&b1->srv.target, &b2->srv.target));
1601 case kDNSType_OPT: return mDNSfalse; // OPT is a pseudo-RR container structure; makes no sense to compare
1602 case kDNSType_NSEC: {
1603 // If the "nxt" name changes in case, we want to delete the old
1604 // and store just the new one. If the caller passes in SameDomainCS for "samename",
1605 // we would return "false" when the only change between the two rdata is the case
1608 // Note: rdlength of both the RData are same (ensured by the caller) and hence we can
1609 // use just r1->rdlength below
1611 int dlen1 = DomainNameLength((domainname *)b1->data);
1612 int dlen2 = DomainNameLength((domainname *)b2->data);
1613 return (mDNSBool)(dlen1 == dlen2 &&
1614 samename((domainname *)b1->data, (domainname *)b2->data) &&
1615 mDNSPlatformMemSame(b1->data + dlen1, b2->data + dlen2, r1->rdlength - dlen1));
1618 default: return(mDNSPlatformMemSame(b1->data, b2->data, r1->rdlength));
1622 mDNSexport mDNSBool BitmapTypeCheck(mDNSu8 *bmap, int bitmaplen, mDNSu16 type)
1627 // The window that this type belongs to. NSEC has 256 windows that
1628 // comprises of 256 types.
1629 wintype = type >> 8;
1631 while (bitmaplen > 0)
1635 LogInfo("BitmapTypeCheck: malformed nsec, bitmaplen %d short", bitmaplen);
1642 if (bitmaplen < wlen || wlen < 1 || wlen > 32)
1644 LogInfo("BitmapTypeCheck: malformed nsec, bitmaplen %d wlen %d, win %d", bitmaplen, wlen, win);
1647 if (win < 0 || win >= 256)
1649 LogInfo("BitmapTypeCheck: malformed nsec, wlen %d", wlen);
1654 // First byte in the window serves 0 to 7, the next one serves 8 to 15 and so on.
1655 // Calculate the right byte offset first.
1656 int boff = (type & 0xff ) >> 3;
1659 // The last three bits values 0 to 7 corresponds to bit positions
1661 return (bmap[boff] & (0x80 >> (type & 7)));
1665 // If the windows are ordered, then we could check to see
1666 // if wintype > win and then return early.
1674 // Don't call this function if the resource record is not NSEC. It will return false
1675 // which means that the type does not exist.
1676 mDNSexport mDNSBool RRAssertsExistence(const ResourceRecord *const rr, mDNSu16 type)
1678 const RDataBody2 *const rdb = (RDataBody2 *)rr->rdata->u.data;
1679 mDNSu8 *nsec = (mDNSu8 *)rdb->data;
1683 if (rr->rrtype != kDNSType_NSEC) return mDNSfalse;
1685 len = DomainNameLength((domainname *)nsec);
1687 bitmaplen = rr->rdlength - len;
1689 return (BitmapTypeCheck(bmap, bitmaplen, type));
1692 // Don't call this function if the resource record is not NSEC. It will return false
1693 // which means that the type exists.
1694 mDNSexport mDNSBool RRAssertsNonexistence(const ResourceRecord *const rr, mDNSu16 type)
1696 if (rr->rrtype != kDNSType_NSEC) return mDNSfalse;
1698 return !RRAssertsExistence(rr, type);
1701 // Checks whether the RRSIG or NSEC record answers the question "q".
1702 mDNSlocal mDNSBool DNSSECRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q, mDNSBool *checkType)
1704 *checkType = mDNStrue;
1706 // This function is called for all questions and as long as the type matches,
1707 // return true. For the types (RRSIG and NSEC) that are specifically checked in
1708 // this function, returning true still holds good.
1709 if (q->qtype == rr->rrtype)
1712 // For DS and DNSKEY questions, the types should match i.e., don't answer using CNAME
1713 // records as it answers any question type.
1715 // - DS record comes from the parent zone where CNAME record cannot coexist and hence
1716 // cannot possibly answer it.
1718 // - For DNSKEY, one could potentially follow CNAME but there could be a DNSKEY at
1719 // the "qname" itself. To keep it simple, we don't follow CNAME.
1721 if ((q->qtype == kDNSType_DS || q->qtype == kDNSType_DNSKEY) && (q->qtype != rr->rrtype))
1723 debugf("DNSSECRecordAnswersQuestion: %d type resource record matched question %##s (%s), ignoring", rr->rrtype,
1724 q->qname.c, DNSTypeName(q->qtype));
1728 // If we are validating a response using DNSSEC, we might already have the records
1729 // for the "q->qtype" in the cache but we issued a query with DO bit set
1730 // to get the RRSIGs e.g., if you have two questions one of which does not require
1731 // DNSSEC validation. When the RRSIG is added to the cache, we need to deliver
1732 // the response to the question. The RRSIG type won't match the q->qtype and hence
1733 // we need to bypass the check in that case.
1734 if (rr->rrtype == kDNSType_RRSIG && q->ValidatingResponse)
1736 const RDataBody2 *const rdb = (RDataBody2 *)rr->rdata->u.data;
1737 rdataRRSig *rrsig = (rdataRRSig *)rdb->data;
1738 mDNSu16 typeCovered = swap16(rrsig->typeCovered);
1739 debugf("DNSSECRecordAnswersQuestion: Matching RRSIG typeCovered %s", DNSTypeName(typeCovered));
1740 if (typeCovered != kDNSType_CNAME && typeCovered != q->qtype)
1742 debugf("DNSSECRecordAnswersQuestion: RRSIG did not match question %##s (%s)", q->qname.c,
1743 DNSTypeName(q->qtype));
1746 LogInfo("DNSSECRecordAnswersQuestion: RRSIG matched question %##s (%s)", q->qname.c,
1747 DNSTypeName(q->qtype));
1748 *checkType = mDNSfalse;
1751 // If the NSEC record asserts the non-existence of a name looked up by the question, we would
1752 // typically answer that e.g., the bitmap asserts that q->qtype does not exist. If we have
1753 // to prove the non-existence as required by ValidatingResponse and ValidationRequired question,
1754 // then we should not answer that as it may not be the right one always. We may need more than
1755 // one NSEC to prove the non-existence.
1756 if (rr->rrtype == kDNSType_NSEC && DNSSECQuestion(q))
1758 debugf("DNSSECRecordAnswersQuestion: Question %##s (%s) matched record %##s (NSEC)", q->qname.c,
1759 DNSTypeName(q->qtype), rr->name->c);
1765 // ResourceRecordAnswersQuestion returns mDNStrue if the given resource record is a valid answer to the given question.
1766 // SameNameRecordAnswersQuestion is the same, except it skips the expensive SameDomainName() call.
1767 // SameDomainName() is generally cheap when the names don't match, but expensive when they do match,
1768 // because it has to check all the way to the end of the names to be sure.
1769 // In cases where we know in advance that the names match it's especially advantageous to skip the
1770 // SameDomainName() call because that's precisely the time when it's most expensive and least useful.
1772 mDNSexport mDNSBool SameNameRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q)
1774 mDNSBool checkType = mDNStrue;
1776 // LocalOnly/P2P questions can be answered with AuthRecordAny in this function. LocalOnly/P2P records
1777 // are handled in LocalOnlyRecordAnswersQuestion
1778 if (LocalOnlyOrP2PInterface(rr->InterfaceID))
1780 LogMsg("SameNameRecordAnswersQuestion: ERROR!! called with LocalOnly ResourceRecord %p, Question %p", rr->InterfaceID, q->InterfaceID);
1783 if (QuerySuppressed(q))
1786 if (rr->InterfaceID &&
1787 q->InterfaceID && q->InterfaceID != mDNSInterface_LocalOnly &&
1788 rr->InterfaceID != q->InterfaceID) return(mDNSfalse);
1790 // Resource record received via unicast, the resolver group ID should match ?
1791 if (!rr->InterfaceID)
1793 mDNSu16 idr = (rr->rDNSServer ? rr->rDNSServer->resGroupID : 0);
1794 mDNSu16 idq = (q->qDNSServer ? q->qDNSServer->resGroupID : 0);
1795 if (idr != idq) return(mDNSfalse);
1796 if (!DNSSECRecordAnswersQuestion(rr, q, &checkType)) return mDNSfalse;
1799 // If ResourceRecord received via multicast, but question was unicast, then shouldn't use record to answer this question
1800 if (rr->InterfaceID && !mDNSOpaque16IsZero(q->TargetQID)) return(mDNSfalse);
1802 // CNAME answers question of any type and a negative cache record should not prevent us from querying other
1803 // valid types at the same name.
1804 if (rr->rrtype == kDNSType_CNAME && rr->RecordType == kDNSRecordTypePacketNegative && rr->rrtype != q->qtype)
1807 // RR type CNAME matches any query type. QTYPE ANY matches any RR type. QCLASS ANY matches any RR class.
1808 if (checkType && !RRTypeAnswersQuestionType(rr,q->qtype)) return(mDNSfalse);
1809 if (rr->rrclass != q->qclass && q->qclass != kDNSQClass_ANY) return(mDNSfalse);
1811 #if APPLE_OSX_mDNSResponder
1812 if (!mDNSPlatformValidRecordForQuestion(rr, q))
1814 #endif // APPLE_OSX_mDNSResponder
1816 if (!AnonInfoAnswersQuestion(rr, q))
1822 mDNSexport mDNSBool ResourceRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q)
1824 if (!SameNameRecordAnswersQuestion(rr, q))
1827 return(rr->namehash == q->qnamehash && SameDomainName(rr->name, &q->qname));
1830 // We have a separate function to handle LocalOnly AuthRecords because they can be created with
1831 // a valid InterfaceID (e.g., scoped /etc/hosts) and can be used to answer unicast questions unlike
1832 // multicast resource records (which has a valid InterfaceID) which can't be used to answer
1833 // unicast questions. ResourceRecordAnswersQuestion/SameNameRecordAnswersQuestion can't tell whether
1834 // a resource record is multicast or LocalOnly by just looking at the ResourceRecord because
1835 // LocalOnly records are truly identified by ARType in the AuthRecord. As P2P and LocalOnly record
1836 // are kept in the same hash table, we use the same function to make it easy for the callers when
1837 // they walk the hash table to answer LocalOnly/P2P questions
1839 mDNSexport mDNSBool LocalOnlyRecordAnswersQuestion(AuthRecord *const ar, const DNSQuestion *const q)
1841 ResourceRecord *rr = &ar->resrec;
1843 // mDNSInterface_Any questions can be answered with LocalOnly/P2P records in this function. AuthRecord_Any
1844 // records are handled in ResourceRecordAnswersQuestion/SameNameRecordAnswersQuestion
1847 LogMsg("LocalOnlyRecordAnswersQuestion: ERROR!! called with regular AuthRecordAny %##s", rr->name->c);
1851 // Questions with mDNSInterface_LocalOnly InterfaceID should be answered with all resource records that are
1852 // *local* to the machine. These include resource records that have InterfaceID set to mDNSInterface_LocalOnly,
1853 // mDNSInterface_Any and any other real InterfaceID. Hence, LocalOnly questions should not be checked against
1854 // the InterfaceID in the resource record.
1856 // mDNSInterface_Unicast does not indicate any scope and hence treat them like mDNSInterface_Any.
1858 if (rr->InterfaceID &&
1859 q->InterfaceID && q->InterfaceID != mDNSInterface_LocalOnly && q->InterfaceID != mDNSInterface_Unicast &&
1860 rr->InterfaceID != q->InterfaceID) return(mDNSfalse);
1862 // Entries in /etc/hosts are added as LocalOnly resource records. The LocalOnly resource records
1863 // may have a scope e.g., fe80::1%en0. The question may be scoped or not: the InterfaceID may be set
1864 // to mDNSInterface_Any, mDNSInterface_LocalOnly or a real InterfaceID (scoped).
1866 // 1) Question: Any, LocalOnly Record: no scope. This question should be answered with this record.
1868 // 2) Question: Any, LocalOnly Record: scoped. This question should be answered with the record because
1869 // traditionally applications never specify scope e.g., getaddrinfo, but need to be able
1870 // to get to /etc/hosts entries.
1872 // 3) Question: Scoped (LocalOnly or InterfaceID), LocalOnly Record: no scope. This is the inverse of (2).
1873 // If we register a LocalOnly record, we need to answer a LocalOnly question. If the /etc/hosts has a
1874 // non scoped entry, it may not make sense to answer a scoped question. But we can't tell these two
1875 // cases apart. As we currently answer LocalOnly question with LocalOnly record, we continue to do so.
1877 // 4) Question: Scoped (LocalOnly or InterfaceID), LocalOnly Record: scoped. LocalOnly questions should be
1878 // answered with any resource record where as if it has a valid InterfaceID, the scope should match.
1880 // (1) and (2) is bypassed because we check for a non-NULL InterfaceID above. For (3), the InterfaceID is NULL
1881 // and hence bypassed above. For (4) we bypassed LocalOnly questions and checked the scope of the record
1882 // against the question.
1884 // For P2P, InterfaceIDs of the question and the record should match.
1886 // If ResourceRecord received via multicast, but question was unicast, then shouldn't use record to answer this question.
1887 // LocalOnly authoritative answers are exempt. LocalOnly authoritative answers are used for /etc/host entries.
1888 // We don't want a local process to be able to create a fake LocalOnly address record for "www.bigbank.com" which would then
1889 // cause other applications (e.g. Safari) to connect to the wrong address. The rpc to register records filters out records
1890 // with names that don't end in local and have mDNSInterface_LocalOnly set.
1892 // Note: The check is bypassed for LocalOnly and for P2P it is not needed as only .local records are registered and for
1893 // a question to match its names, it also has to end in .local and that question can't be a unicast question (See
1894 // Question_uDNS macro and its usage). As P2P does not enforce .local only registrations we still make this check
1895 // and also makes it future proof.
1897 if (ar->ARType != AuthRecordLocalOnly && rr->InterfaceID && !mDNSOpaque16IsZero(q->TargetQID)) return(mDNSfalse);
1899 // RR type CNAME matches any query type. QTYPE ANY matches any RR type. QCLASS ANY matches any RR class.
1900 if (!RRTypeAnswersQuestionType(rr,q->qtype)) return(mDNSfalse);
1901 if (rr->rrclass != q->qclass && q->qclass != kDNSQClass_ANY) return(mDNSfalse);
1903 if (!AnonInfoAnswersQuestion(rr, q))
1906 return(rr->namehash == q->qnamehash && SameDomainName(rr->name, &q->qname));
1909 mDNSexport mDNSBool AnyTypeRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q)
1911 // LocalOnly/P2P questions can be answered with AuthRecordAny in this function. LocalOnly/P2P records
1912 // are handled in LocalOnlyRecordAnswersQuestion
1913 if (LocalOnlyOrP2PInterface(rr->InterfaceID))
1915 LogMsg("AnyTypeRecordAnswersQuestion: ERROR!! called with LocalOnly ResourceRecord %p, Question %p", rr->InterfaceID, q->InterfaceID);
1918 if (rr->InterfaceID &&
1919 q->InterfaceID && q->InterfaceID != mDNSInterface_LocalOnly &&
1920 rr->InterfaceID != q->InterfaceID) return(mDNSfalse);
1922 // Resource record received via unicast, the resolver group ID should match ?
1923 // Note that Auth Records are normally setup with NULL InterfaceID and
1924 // both the DNSServers are assumed to be NULL in that case
1925 if (!rr->InterfaceID)
1927 mDNSu16 idr = (rr->rDNSServer ? rr->rDNSServer->resGroupID : 0);
1928 mDNSu16 idq = (q->qDNSServer ? q->qDNSServer->resGroupID : 0);
1929 if (idr != idq) return(mDNSfalse);
1932 // If ResourceRecord received via multicast, but question was unicast, then shouldn't use record to answer this question
1933 if (rr->InterfaceID && !mDNSOpaque16IsZero(q->TargetQID)) return(mDNSfalse);
1935 if (rr->rrclass != q->qclass && q->qclass != kDNSQClass_ANY) return(mDNSfalse);
1937 if (!AnonInfoAnswersQuestion(rr, q))
1940 return(rr->namehash == q->qnamehash && SameDomainName(rr->name, &q->qname));
1943 // This is called with both unicast resource record and multicast resource record. The question that
1944 // received the unicast response could be the regular unicast response from a DNS server or a response
1945 // to a mDNS QU query. The main reason we need this function is that we can't compare DNSServers between the
1946 // question and the resource record because the resource record is not completely initialized in
1947 // mDNSCoreReceiveResponse when this function is called.
1948 mDNSexport mDNSBool ResourceRecordAnswersUnicastResponse(const ResourceRecord *const rr, const DNSQuestion *const q)
1950 mDNSBool checkType = mDNStrue;
1952 if (QuerySuppressed(q))
1955 // For resource records created using multicast, the InterfaceIDs have to match
1956 if (rr->InterfaceID &&
1957 q->InterfaceID && rr->InterfaceID != q->InterfaceID) return(mDNSfalse);
1959 // If ResourceRecord received via multicast, but question was unicast, then shouldn't use record to answer this question.
1960 if (rr->InterfaceID && !mDNSOpaque16IsZero(q->TargetQID)) return(mDNSfalse);
1962 if (!DNSSECRecordAnswersQuestion(rr, q, &checkType)) return mDNSfalse;
1964 // RR type CNAME matches any query type. QTYPE ANY matches any RR type. QCLASS ANY matches any RR class.
1965 if (checkType && !RRTypeAnswersQuestionType(rr,q->qtype)) return(mDNSfalse);
1967 if (rr->rrclass != q->qclass && q->qclass != kDNSQClass_ANY) return(mDNSfalse);
1969 return(rr->namehash == q->qnamehash && SameDomainName(rr->name, &q->qname));
1972 mDNSexport mDNSu16 GetRDLength(const ResourceRecord *const rr, mDNSBool estimate)
1974 const RDataBody2 *const rd = (RDataBody2 *)rr->rdata->u.data;
1975 const domainname *const name = estimate ? rr->name : mDNSNULL;
1976 if (rr->rrclass == kDNSQClass_ANY) return(rr->rdlength); // Used in update packets to mean "Delete An RRset" (RFC 2136)
1977 else switch (rr->rrtype)
1979 case kDNSType_A: return(sizeof(rd->ipv4));
1982 case kDNSType_CNAME:
1984 case kDNSType_DNAME: return(CompressedDomainNameLength(&rd->name, name));
1986 case kDNSType_SOA: return (mDNSu16)(CompressedDomainNameLength(&rd->soa.mname, name) +
1987 CompressedDomainNameLength(&rd->soa.rname, name) +
1988 5 * sizeof(mDNSOpaque32));
1996 case kDNSType_DHCID: return(rr->rdlength); // Not self-describing, so have to just trust rdlength
1998 case kDNSType_HINFO: return (mDNSu16)(2 + (int)rd->data[0] + (int)rd->data[1 + (int)rd->data[0]]);
2001 case kDNSType_AFSDB:
2003 case kDNSType_KX: return (mDNSu16)(2 + CompressedDomainNameLength(&rd->mx.exchange, name));
2005 case kDNSType_RP: return (mDNSu16)(CompressedDomainNameLength(&rd->rp.mbox, name) +
2006 CompressedDomainNameLength(&rd->rp.txt, name));
2008 case kDNSType_PX: return (mDNSu16)(2 + CompressedDomainNameLength(&rd->px.map822, name) +
2009 CompressedDomainNameLength(&rd->px.mapx400, name));
2011 case kDNSType_AAAA: return(sizeof(rd->ipv6));
2013 case kDNSType_SRV: return (mDNSu16)(6 + CompressedDomainNameLength(&rd->srv.target, name));
2015 case kDNSType_OPT: return(rr->rdlength);
2017 case kDNSType_NSEC: {
2018 domainname *next = (domainname *)rd->data;
2019 int dlen = DomainNameLength(next);
2021 if (UNICAST_NSEC(rr))
2022 return (mDNSu16)(CompressedDomainNameLength(next, name) + rr->rdlength - dlen);
2024 return (mDNSu16)((estimate ? 2 : dlen) + rr->rdlength - dlen);
2027 default: debugf("Warning! Don't know how to get length of resource type %d", rr->rrtype);
2028 return(rr->rdlength);
2032 // When a local client registers (or updates) a record, we use this routine to do some simple validation checks
2033 // to help reduce the risk of bogus malformed data on the network
2034 mDNSexport mDNSBool ValidateRData(const mDNSu16 rrtype, const mDNSu16 rdlength, const RData *const rd)
2040 case kDNSType_A: return(rdlength == sizeof(mDNSv4Addr));
2042 case kDNSType_NS: // Same as PTR
2043 case kDNSType_MD: // Same as PTR
2044 case kDNSType_MF: // Same as PTR
2045 case kDNSType_CNAME: // Same as PTR
2046 //case kDNSType_SOA not checked
2047 case kDNSType_MB: // Same as PTR
2048 case kDNSType_MG: // Same as PTR
2049 case kDNSType_MR: // Same as PTR
2050 //case kDNSType_NULL not checked (no specified format, so always valid)
2051 //case kDNSType_WKS not checked
2052 case kDNSType_PTR: len = DomainNameLengthLimit(&rd->u.name, rd->u.data + rdlength);
2053 return(len <= MAX_DOMAIN_NAME && rdlength == len);
2055 case kDNSType_HINFO: // Same as TXT (roughly)
2056 case kDNSType_MINFO: // Same as TXT (roughly)
2057 case kDNSType_TXT: if (!rdlength) return(mDNSfalse); // TXT record has to be at least one byte (RFC 1035)
2059 const mDNSu8 *ptr = rd->u.txt.c;
2060 const mDNSu8 *end = rd->u.txt.c + rdlength;
2061 while (ptr < end) ptr += 1 + ptr[0];
2062 return (ptr == end);
2065 case kDNSType_AAAA: return(rdlength == sizeof(mDNSv6Addr));
2067 case kDNSType_MX: // Must be at least two-byte preference, plus domainname
2068 // Call to DomainNameLengthLimit() implicitly enforces both requirements for us
2069 len = DomainNameLengthLimit(&rd->u.mx.exchange, rd->u.data + rdlength);
2070 return(len <= MAX_DOMAIN_NAME && rdlength == 2+len);
2072 case kDNSType_SRV: // Must be at least priority+weight+port, plus domainname
2073 // Call to DomainNameLengthLimit() implicitly enforces both requirements for us
2074 len = DomainNameLengthLimit(&rd->u.srv.target, rd->u.data + rdlength);
2075 return(len <= MAX_DOMAIN_NAME && rdlength == 6+len);
2077 //case kDNSType_NSEC not checked
2079 default: return(mDNStrue); // Allow all other types without checking
2083 // ***************************************************************************
2084 #if COMPILER_LIKES_PRAGMA_MARK
2086 #pragma mark - DNS Message Creation Functions
2089 mDNSexport void InitializeDNSMessage(DNSMessageHeader *h, mDNSOpaque16 id, mDNSOpaque16 flags)
2093 h->numQuestions = 0;
2095 h->numAuthorities = 0;
2096 h->numAdditionals = 0;
2099 mDNSexport const mDNSu8 *FindCompressionPointer(const mDNSu8 *const base, const mDNSu8 *const end, const mDNSu8 *const domname)
2101 const mDNSu8 *result = end - *domname - 1;
2103 if (*domname == 0) return(mDNSNULL); // There's no point trying to match just the root label
2105 // This loop examines each possible starting position in packet, starting end of the packet and working backwards
2106 while (result >= base)
2108 // If the length byte and first character of the label match, then check further to see
2109 // if this location in the packet will yield a useful name compression pointer.
2110 if (result[0] == domname[0] && result[1] == domname[1])
2112 const mDNSu8 *name = domname;
2113 const mDNSu8 *targ = result;
2114 while (targ + *name < end)
2116 // First see if this label matches
2118 const mDNSu8 *pointertarget;
2119 for (i=0; i <= *name; i++) if (targ[i] != name[i]) break;
2120 if (i <= *name) break; // If label did not match, bail out
2121 targ += 1 + *name; // Else, did match, so advance target pointer
2122 name += 1 + *name; // and proceed to check next label
2123 if (*name == 0 && *targ == 0) return(result); // If no more labels, we found a match!
2124 if (*name == 0) break; // If no more labels to match, we failed, so bail out
2126 // The label matched, so now follow the pointer (if appropriate) and then see if the next label matches
2127 if (targ[0] < 0x40) continue; // If length value, continue to check next label
2128 if (targ[0] < 0xC0) break; // If 40-BF, not valid
2129 if (targ+1 >= end) break; // Second byte not present!
2130 pointertarget = base + (((mDNSu16)(targ[0] & 0x3F)) << 8) + targ[1];
2131 if (targ < pointertarget) break; // Pointertarget must point *backwards* in the packet
2132 if (pointertarget[0] >= 0x40) break; // Pointertarget must point to a valid length byte
2133 targ = pointertarget;
2136 result--; // We failed to match at this search position, so back up the tentative result pointer and try again
2141 // domainname is a fully-qualified name (i.e. assumed to be ending in a dot, even if it doesn't)
2142 // msg points to the message we're building (pass mDNSNULL if we don't want to use compression pointers)
2143 // end points to the end of the message so far
2144 // ptr points to where we want to put the name
2145 // limit points to one byte past the end of the buffer that we must not overrun
2146 // domainname is the name to put
2147 mDNSexport mDNSu8 *putDomainNameAsLabels(const DNSMessage *const msg,
2148 mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name)
2150 const mDNSu8 *const base = (const mDNSu8 *)msg;
2151 const mDNSu8 * np = name->c;
2152 const mDNSu8 *const max = name->c + MAX_DOMAIN_NAME; // Maximum that's valid
2153 const mDNSu8 * pointer = mDNSNULL;
2154 const mDNSu8 *const searchlimit = ptr;
2156 if (!ptr) { LogMsg("putDomainNameAsLabels %##s ptr is null", name->c); return(mDNSNULL); }
2158 if (!*np) // If just writing one-byte root label, make sure we have space for that
2160 if (ptr >= limit) return(mDNSNULL);
2162 else // else, loop through writing labels and/or a compression offset
2165 if (*np > MAX_DOMAIN_LABEL)
2166 { LogMsg("Malformed domain name %##s (label more than 63 bytes)", name->c); return(mDNSNULL); }
2168 // This check correctly allows for the final trailing root label:
2170 // Suppose our domain name is exactly 256 bytes long, including the final trailing root label.
2171 // Suppose np is now at name->c[249], and we're about to write our last non-null label ("local").
2172 // We know that max will be at name->c[256]
2173 // That means that np + 1 + 5 == max - 1, so we (just) pass the "if" test below, write our
2174 // six bytes, then exit the loop, write the final terminating root label, and the domain
2175 // name we've written is exactly 256 bytes long, exactly at the correct legal limit.
2176 // If the name is one byte longer, then we fail the "if" test below, and correctly bail out.
2177 if (np + 1 + *np >= max)
2178 { LogMsg("Malformed domain name %##s (more than 256 bytes)", name->c); return(mDNSNULL); }
2180 if (base) pointer = FindCompressionPointer(base, searchlimit, np);
2181 if (pointer) // Use a compression pointer if we can
2183 const mDNSu16 offset = (mDNSu16)(pointer - base);
2184 if (ptr+2 > limit) return(mDNSNULL); // If we don't have two bytes of space left, give up
2185 *ptr++ = (mDNSu8)(0xC0 | (offset >> 8));
2186 *ptr++ = (mDNSu8)( offset & 0xFF);
2189 else // Else copy one label and try again
2193 // If we don't at least have enough space for this label *plus* a terminating zero on the end, give up
2194 if (ptr + 1 + len >= limit) return(mDNSNULL);
2196 for (i=0; i<len; i++) *ptr++ = *np++;
2198 } while (*np); // While we've got characters remaining in the name, continue
2201 *ptr++ = 0; // Put the final root label
2205 mDNSlocal mDNSu8 *putVal16(mDNSu8 *ptr, mDNSu16 val)
2207 ptr[0] = (mDNSu8)((val >> 8 ) & 0xFF);
2208 ptr[1] = (mDNSu8)((val ) & 0xFF);
2209 return ptr + sizeof(mDNSOpaque16);
2212 mDNSlocal mDNSu8 *putVal32(mDNSu8 *ptr, mDNSu32 val)
2214 ptr[0] = (mDNSu8)((val >> 24) & 0xFF);
2215 ptr[1] = (mDNSu8)((val >> 16) & 0xFF);
2216 ptr[2] = (mDNSu8)((val >> 8) & 0xFF);
2217 ptr[3] = (mDNSu8)((val ) & 0xFF);
2218 return ptr + sizeof(mDNSu32);
2221 // Copy the RDATA information. The actual in memory storage for the data might be bigger than what the rdlength
2222 // says. Hence, the only way to copy out the data from a resource record is to use putRData.
2223 // msg points to the message we're building (pass mDNSNULL for "msg" if we don't want to use compression pointers)
2224 mDNSexport mDNSu8 *putRData(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const ResourceRecord *const rr)
2226 const RDataBody2 *const rdb = (RDataBody2 *)rr->rdata->u.data;
2229 case kDNSType_A: if (rr->rdlength != 4)
2230 { debugf("putRData: Illegal length %d for kDNSType_A", rr->rdlength); return(mDNSNULL); }
2231 if (ptr + 4 > limit) return(mDNSNULL);
2232 *ptr++ = rdb->ipv4.b[0];
2233 *ptr++ = rdb->ipv4.b[1];
2234 *ptr++ = rdb->ipv4.b[2];
2235 *ptr++ = rdb->ipv4.b[3];
2239 case kDNSType_CNAME:
2241 case kDNSType_DNAME: return(putDomainNameAsLabels(msg, ptr, limit, &rdb->name));
2243 case kDNSType_SOA: ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->soa.mname);
2244 if (!ptr) return(mDNSNULL);
2245 ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->soa.rname);
2246 if (!ptr || ptr + 20 > limit) return(mDNSNULL);
2247 ptr = putVal32(ptr, rdb->soa.serial);
2248 ptr = putVal32(ptr, rdb->soa.refresh);
2249 ptr = putVal32(ptr, rdb->soa.retry);
2250 ptr = putVal32(ptr, rdb->soa.expire);
2251 ptr = putVal32(ptr, rdb->soa.min);
2255 case kDNSType_HINFO:
2261 case kDNSType_DHCID: if (ptr + rr->rdlength > limit) return(mDNSNULL);
2262 mDNSPlatformMemCopy(ptr, rdb->data, rr->rdlength);
2263 return(ptr + rr->rdlength);
2266 case kDNSType_AFSDB:
2268 case kDNSType_KX: if (ptr + 3 > limit) return(mDNSNULL);
2269 ptr = putVal16(ptr, rdb->mx.preference);
2270 return(putDomainNameAsLabels(msg, ptr, limit, &rdb->mx.exchange));
2272 case kDNSType_RP: ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->rp.mbox);
2273 if (!ptr) return(mDNSNULL);
2274 ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->rp.txt);
2277 case kDNSType_PX: if (ptr + 5 > limit) return(mDNSNULL);
2278 ptr = putVal16(ptr, rdb->px.preference);
2279 ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->px.map822);
2280 if (!ptr) return(mDNSNULL);
2281 ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->px.mapx400);
2284 case kDNSType_AAAA: if (rr->rdlength != sizeof(rdb->ipv6))
2285 { debugf("putRData: Illegal length %d for kDNSType_AAAA", rr->rdlength); return(mDNSNULL); }
2286 if (ptr + sizeof(rdb->ipv6) > limit) return(mDNSNULL);
2287 mDNSPlatformMemCopy(ptr, &rdb->ipv6, sizeof(rdb->ipv6));
2288 return(ptr + sizeof(rdb->ipv6));
2290 case kDNSType_SRV: if (ptr + 7 > limit) return(mDNSNULL);
2291 *ptr++ = (mDNSu8)(rdb->srv.priority >> 8);
2292 *ptr++ = (mDNSu8)(rdb->srv.priority & 0xFF);
2293 *ptr++ = (mDNSu8)(rdb->srv.weight >> 8);
2294 *ptr++ = (mDNSu8)(rdb->srv.weight & 0xFF);
2295 *ptr++ = rdb->srv.port.b[0];
2296 *ptr++ = rdb->srv.port.b[1];
2297 return(putDomainNameAsLabels(msg, ptr, limit, &rdb->srv.target));
2299 case kDNSType_OPT: {
2301 const rdataOPT *opt;
2302 const rdataOPT *const end = (const rdataOPT *)&rr->rdata->u.data[rr->rdlength];
2303 for (opt = &rr->rdata->u.opt[0]; opt < end; opt++)
2304 len += DNSOpt_Data_Space(opt);
2305 if (ptr + len > limit)
2307 LogMsg("ERROR: putOptRData - out of space");
2310 for (opt = &rr->rdata->u.opt[0]; opt < end; opt++)
2312 const int space = DNSOpt_Data_Space(opt);
2313 ptr = putVal16(ptr, opt->opt);
2314 ptr = putVal16(ptr, (mDNSu16)space - 4);
2318 ptr = putVal16(ptr, opt->u.llq.vers);
2319 ptr = putVal16(ptr, opt->u.llq.llqOp);
2320 ptr = putVal16(ptr, opt->u.llq.err);
2321 mDNSPlatformMemCopy(ptr, opt->u.llq.id.b, 8); // 8-byte id
2323 ptr = putVal32(ptr, opt->u.llq.llqlease);
2326 ptr = putVal32(ptr, opt->u.updatelease);
2329 *ptr++ = opt->u.owner.vers;
2330 *ptr++ = opt->u.owner.seq;
2331 mDNSPlatformMemCopy(ptr, opt->u.owner.HMAC.b, 6); // 6-byte Host identifier
2333 if (space >= DNSOpt_OwnerData_ID_Wake_Space)
2335 mDNSPlatformMemCopy(ptr, opt->u.owner.IMAC.b, 6); // 6-byte interface MAC
2337 if (space > DNSOpt_OwnerData_ID_Wake_Space)
2339 mDNSPlatformMemCopy(ptr, opt->u.owner.password.b, space - DNSOpt_OwnerData_ID_Wake_Space);
2340 ptr += space - DNSOpt_OwnerData_ID_Wake_Space;
2345 *ptr++ = opt->u.tracer.platf;
2346 ptr = putVal32(ptr, opt->u.tracer.mDNSv);
2353 case kDNSType_NSEC: {
2354 // For NSEC records, rdlength represents the exact number of bytes
2355 // of in memory storage.
2356 mDNSu8 *nsec = (mDNSu8 *)rdb->data;
2357 domainname *name = (domainname *)nsec;
2358 const int dlen = DomainNameLength(name);
2360 // This function is called when we are sending a NSEC record as part of mDNS,
2361 // or to copy the data to any other buffer needed which could be a mDNS or uDNS
2362 // NSEC record. The only time compression is used that when we are sending it
2363 // in mDNS (indicated by non-NULL "msg") and hence we handle mDNS case
2365 if (!UNICAST_NSEC(rr))
2370 nsec += 2; // Skip the window number and len
2372 // For our simplified use of NSEC synthetic records:
2374 // nextname is always the record's own name,
2375 // the block number is always 0,
2376 // the count byte is a value in the range 1-32,
2377 // followed by the 1-32 data bytes
2379 // Note: When we send the NSEC record in mDNS, the window size is set to 32.
2380 // We need to find out what the last non-NULL byte is. If we are copying out
2381 // from an RDATA, we have the right length. As we need to handle both the case,
2382 // we loop to find the right value instead of blindly using len to copy.
2384 for (i=wlen; i>0; i--) if (nsec[i-1]) break;
2386 ptr = putDomainNameAsLabels(msg, ptr, limit, rr->name);
2387 if (!ptr) { LogInfo("putRData: Can't put name, Length %d, record %##s", limit - save, rr->name->c); return(mDNSNULL); }
2388 if (i) // Only put a block if at least one type exists for this name
2390 if (ptr + 2 + i > limit) { LogInfo("putRData: Can't put window, Length %d, i %d, record %##s", limit - ptr, i, rr->name->c); return(mDNSNULL); }
2393 for (j=0; j<i; j++) *ptr++ = nsec[j];
2400 int len = rr->rdlength - dlen;
2402 // Sanity check whether the bitmap is good
2406 { LogMsg("putRData: invalid length %d", len); return mDNSNULL; }
2411 if (len < wlen || wlen < 1 || wlen > 32)
2412 { LogMsg("putRData: invalid window length %d", wlen); return mDNSNULL; }
2413 if (win < 0 || win >= 256)
2414 { LogMsg("putRData: invalid window %d", win); return mDNSNULL; }
2419 if (ptr + rr->rdlength > limit) { LogMsg("putRData: NSEC rdlength beyond limit %##s (%s), ptr %p, rdlength %d, limit %p", rr->name->c, DNSTypeName(rr->rrtype), ptr, rr->rdlength, limit); return(mDNSNULL);}
2421 // No compression allowed for "nxt", just copy the data.
2422 mDNSPlatformMemCopy(ptr, rdb->data, rr->rdlength);
2423 return(ptr + rr->rdlength);
2427 default: debugf("putRData: Warning! Writing unknown resource type %d as raw data", rr->rrtype);
2428 if (ptr + rr->rdlength > limit) return(mDNSNULL);
2429 mDNSPlatformMemCopy(ptr, rdb->data, rr->rdlength);
2430 return(ptr + rr->rdlength);
2434 #define IsUnicastUpdate(X) (!mDNSOpaque16IsZero((X)->h.id) && ((X)->h.flags.b[0] & kDNSFlag0_OP_Mask) == kDNSFlag0_OP_Update)
2436 mDNSexport mDNSu8 *PutResourceRecordTTLWithLimit(DNSMessage *const msg, mDNSu8 *ptr, mDNSu16 *count, ResourceRecord *rr, mDNSu32 ttl, const mDNSu8 *limit)
2439 mDNSu16 actualLength;
2440 // When sending SRV to conventional DNS server (i.e. in DNS update requests) we should not do name compression on the rdata (RFC 2782)
2441 const DNSMessage *const rdatacompressionbase = (IsUnicastUpdate(msg) && rr->rrtype == kDNSType_SRV) ? mDNSNULL : msg;
2443 if (rr->RecordType == kDNSRecordTypeUnregistered)
2445 LogMsg("PutResourceRecordTTLWithLimit ERROR! Attempt to put kDNSRecordTypeUnregistered %##s (%s)", rr->name->c, DNSTypeName(rr->rrtype));
2451 LogMsg("PutResourceRecordTTLWithLimit ptr is null %##s (%s)", rr->name->c, DNSTypeName(rr->rrtype));
2455 ptr = putDomainNameAsLabels(msg, ptr, limit, rr->name);
2456 // If we're out-of-space, return mDNSNULL
2457 if (!ptr || ptr + 10 >= limit)
2459 LogInfo("PutResourceRecordTTLWithLimit: can't put name, out of space %##s (%s), ptr %p, limit %p", rr->name->c,
2460 DNSTypeName(rr->rrtype), ptr, limit);
2463 ptr[0] = (mDNSu8)(rr->rrtype >> 8);
2464 ptr[1] = (mDNSu8)(rr->rrtype & 0xFF);
2465 ptr[2] = (mDNSu8)(rr->rrclass >> 8);
2466 ptr[3] = (mDNSu8)(rr->rrclass & 0xFF);
2467 ptr[4] = (mDNSu8)((ttl >> 24) & 0xFF);
2468 ptr[5] = (mDNSu8)((ttl >> 16) & 0xFF);
2469 ptr[6] = (mDNSu8)((ttl >> 8) & 0xFF);
2470 ptr[7] = (mDNSu8)( ttl & 0xFF);
2471 // ptr[8] and ptr[9] filled in *after* we find out how much space the rdata takes
2473 endofrdata = putRData(rdatacompressionbase, ptr+10, limit, rr);
2476 LogInfo("PutResourceRecordTTLWithLimit: Ran out of space in PutResourceRecord for %##s (%s), ptr %p, limit %p", rr->name->c,
2477 DNSTypeName(rr->rrtype), ptr+10, limit);
2481 // Go back and fill in the actual number of data bytes we wrote
2482 // (actualLength can be less than rdlength when domain name compression is used)
2483 actualLength = (mDNSu16)(endofrdata - ptr - 10);
2484 ptr[8] = (mDNSu8)(actualLength >> 8);
2485 ptr[9] = (mDNSu8)(actualLength & 0xFF);
2487 if (count) (*count)++;
2488 else LogMsg("PutResourceRecordTTL: ERROR: No target count to update for %##s (%s)", rr->name->c, DNSTypeName(rr->rrtype));
2492 mDNSlocal mDNSu8 *putEmptyResourceRecord(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, mDNSu16 *count, const AuthRecord *rr)
2494 ptr = putDomainNameAsLabels(msg, ptr, limit, rr->resrec.name);
2495 if (!ptr || ptr + 10 > limit) return(mDNSNULL); // If we're out-of-space, return mDNSNULL
2496 ptr[0] = (mDNSu8)(rr->resrec.rrtype >> 8); // Put type
2497 ptr[1] = (mDNSu8)(rr->resrec.rrtype & 0xFF);
2498 ptr[2] = (mDNSu8)(rr->resrec.rrclass >> 8); // Put class
2499 ptr[3] = (mDNSu8)(rr->resrec.rrclass & 0xFF);
2500 ptr[4] = ptr[5] = ptr[6] = ptr[7] = 0; // TTL is zero
2501 ptr[8] = ptr[9] = 0; // RDATA length is zero
2506 mDNSexport mDNSu8 *putQuestion(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name, mDNSu16 rrtype, mDNSu16 rrclass)
2508 ptr = putDomainNameAsLabels(msg, ptr, limit, name);
2509 if (!ptr || ptr+4 >= limit) return(mDNSNULL); // If we're out-of-space, return mDNSNULL
2510 ptr[0] = (mDNSu8)(rrtype >> 8);
2511 ptr[1] = (mDNSu8)(rrtype & 0xFF);
2512 ptr[2] = (mDNSu8)(rrclass >> 8);
2513 ptr[3] = (mDNSu8)(rrclass & 0xFF);
2514 msg->h.numQuestions++;
2518 // for dynamic updates
2519 mDNSexport mDNSu8 *putZone(DNSMessage *const msg, mDNSu8 *ptr, mDNSu8 *limit, const domainname *zone, mDNSOpaque16 zoneClass)
2521 ptr = putDomainNameAsLabels(msg, ptr, limit, zone);
2522 if (!ptr || ptr + 4 > limit) return mDNSNULL; // If we're out-of-space, return NULL
2523 *ptr++ = (mDNSu8)(kDNSType_SOA >> 8);
2524 *ptr++ = (mDNSu8)(kDNSType_SOA & 0xFF);
2525 *ptr++ = zoneClass.b[0];
2526 *ptr++ = zoneClass.b[1];
2527 msg->h.mDNS_numZones++;
2531 // for dynamic updates
2532 mDNSexport mDNSu8 *putPrereqNameNotInUse(const domainname *const name, DNSMessage *const msg, mDNSu8 *const ptr, mDNSu8 *const end)
2535 mDNS_SetupResourceRecord(&prereq, mDNSNULL, mDNSInterface_Any, kDNSQType_ANY, kStandardTTL, 0, AuthRecordAny, mDNSNULL, mDNSNULL);
2536 AssignDomainName(&prereq.namestorage, name);
2537 prereq.resrec.rrtype = kDNSQType_ANY;
2538 prereq.resrec.rrclass = kDNSClass_NONE;
2539 return putEmptyResourceRecord(msg, ptr, end, &msg->h.mDNS_numPrereqs, &prereq);
2542 // for dynamic updates
2543 mDNSexport mDNSu8 *putDeletionRecord(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr)
2545 // deletion: specify record w/ TTL 0, class NONE
2546 const mDNSu16 origclass = rr->rrclass;
2547 rr->rrclass = kDNSClass_NONE;
2548 ptr = PutResourceRecordTTLJumbo(msg, ptr, &msg->h.mDNS_numUpdates, rr, 0);
2549 rr->rrclass = origclass;
2553 // for dynamic updates
2554 mDNSexport mDNSu8 *putDeletionRecordWithLimit(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr, mDNSu8 *limit)
2556 // deletion: specify record w/ TTL 0, class NONE
2557 const mDNSu16 origclass = rr->rrclass;
2558 rr->rrclass = kDNSClass_NONE;
2559 ptr = PutResourceRecordTTLWithLimit(msg, ptr, &msg->h.mDNS_numUpdates, rr, 0, limit);
2560 rr->rrclass = origclass;
2564 mDNSexport mDNSu8 *putDeleteRRSetWithLimit(DNSMessage *msg, mDNSu8 *ptr, const domainname *name, mDNSu16 rrtype, mDNSu8 *limit)
2566 mDNSu16 class = kDNSQClass_ANY;
2568 ptr = putDomainNameAsLabels(msg, ptr, limit, name);
2569 if (!ptr || ptr + 10 >= limit) return mDNSNULL; // If we're out-of-space, return mDNSNULL
2570 ptr[0] = (mDNSu8)(rrtype >> 8);
2571 ptr[1] = (mDNSu8)(rrtype & 0xFF);
2572 ptr[2] = (mDNSu8)(class >> 8);
2573 ptr[3] = (mDNSu8)(class & 0xFF);
2574 ptr[4] = ptr[5] = ptr[6] = ptr[7] = 0; // zero ttl
2575 ptr[8] = ptr[9] = 0; // zero rdlength/rdata
2577 msg->h.mDNS_numUpdates++;
2581 // for dynamic updates
2582 mDNSexport mDNSu8 *putDeleteAllRRSets(DNSMessage *msg, mDNSu8 *ptr, const domainname *name)
2584 const mDNSu8 *limit = msg->data + AbsoluteMaxDNSMessageData;
2585 mDNSu16 class = kDNSQClass_ANY;
2586 mDNSu16 rrtype = kDNSQType_ANY;
2588 ptr = putDomainNameAsLabels(msg, ptr, limit, name);
2589 if (!ptr || ptr + 10 >= limit) return mDNSNULL; // If we're out-of-space, return mDNSNULL
2590 ptr[0] = (mDNSu8)(rrtype >> 8);
2591 ptr[1] = (mDNSu8)(rrtype & 0xFF);
2592 ptr[2] = (mDNSu8)(class >> 8);
2593 ptr[3] = (mDNSu8)(class & 0xFF);
2594 ptr[4] = ptr[5] = ptr[6] = ptr[7] = 0; // zero ttl
2595 ptr[8] = ptr[9] = 0; // zero rdlength/rdata
2597 msg->h.mDNS_numUpdates++;
2601 // for dynamic updates
2602 mDNSexport mDNSu8 *putUpdateLease(DNSMessage *msg, mDNSu8 *ptr, mDNSu32 lease)
2605 mDNS_SetupResourceRecord(&rr, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL);
2606 rr.resrec.rrclass = NormalMaxDNSMessageData;
2607 rr.resrec.rdlength = sizeof(rdataOPT); // One option in this OPT record
2608 rr.resrec.rdestimate = sizeof(rdataOPT);
2609 rr.resrec.rdata->u.opt[0].opt = kDNSOpt_Lease;
2610 rr.resrec.rdata->u.opt[0].u.updatelease = lease;
2611 ptr = PutResourceRecordTTLJumbo(msg, ptr, &msg->h.numAdditionals, &rr.resrec, 0);
2612 if (!ptr) { LogMsg("ERROR: putUpdateLease - PutResourceRecordTTL"); return mDNSNULL; }
2616 // for dynamic updates
2617 mDNSexport mDNSu8 *putUpdateLeaseWithLimit(DNSMessage *msg, mDNSu8 *ptr, mDNSu32 lease, mDNSu8 *limit)
2620 mDNS_SetupResourceRecord(&rr, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL);
2621 rr.resrec.rrclass = NormalMaxDNSMessageData;
2622 rr.resrec.rdlength = sizeof(rdataOPT); // One option in this OPT record
2623 rr.resrec.rdestimate = sizeof(rdataOPT);
2624 rr.resrec.rdata->u.opt[0].opt = kDNSOpt_Lease;
2625 rr.resrec.rdata->u.opt[0].u.updatelease = lease;
2626 ptr = PutResourceRecordTTLWithLimit(msg, ptr, &msg->h.numAdditionals, &rr.resrec, 0, limit);
2627 if (!ptr) { LogMsg("ERROR: putUpdateLeaseWithLimit - PutResourceRecordTTLWithLimit"); return mDNSNULL; }
2631 mDNSexport mDNSu8 *putDNSSECOption(DNSMessage *msg, mDNSu8 *end, mDNSu8 *limit)
2636 mDNS_SetupResourceRecord(&rr, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL);
2637 // It is still not clear what the right size is. We will have to fine tune this once we do
2638 // a lot of testing with DNSSEC.
2639 rr.resrec.rrclass = 4096;
2640 rr.resrec.rdlength = 0;
2641 rr.resrec.rdestimate = 0;
2644 end = PutResourceRecordTTLWithLimit(msg, end, &msg->h.numAdditionals, &rr.resrec, ttl, limit);
2645 if (!end) { LogMsg("ERROR: putDNSSECOption - PutResourceRecordTTLWithLimit"); return mDNSNULL; }
2649 mDNSexport mDNSu8 *putHINFO(const mDNS *const m, DNSMessage *const msg, mDNSu8 *end, DomainAuthInfo *authInfo, mDNSu8 *limit)
2651 if (authInfo && authInfo->AutoTunnel)
2654 mDNSu8 *h = hinfo.rdatastorage.u.data;
2655 mDNSu16 len = 2 + m->HIHardware.c[0] + m->HISoftware.c[0];
2657 mDNS_SetupResourceRecord(&hinfo, mDNSNULL, mDNSInterface_Any, kDNSType_HINFO, 0, kDNSRecordTypeUnique, AuthRecordAny, mDNSNULL, mDNSNULL);
2658 AppendDomainLabel(&hinfo.namestorage, &m->hostlabel);
2659 AppendDomainName (&hinfo.namestorage, &authInfo->domain);
2660 hinfo.resrec.rroriginalttl = 0;
2661 mDNSPlatformMemCopy(h, &m->HIHardware, 1 + (mDNSu32)m->HIHardware.c[0]);
2663 mDNSPlatformMemCopy(h, &m->HISoftware, 1 + (mDNSu32)m->HISoftware.c[0]);
2664 hinfo.resrec.rdlength = len;
2665 hinfo.resrec.rdestimate = len;
2666 newptr = PutResourceRecordTTLWithLimit(msg, end, &msg->h.numAdditionals, &hinfo.resrec, 0, limit);
2673 // ***************************************************************************
2674 #if COMPILER_LIKES_PRAGMA_MARK
2676 #pragma mark - DNS Message Parsing Functions
2679 mDNSexport mDNSu32 DomainNameHashValue(const domainname *const name)
2684 for (c = name->c; c[0] != 0 && c[1] != 0; c += 2)
2686 sum += ((mDNSIsUpperCase(c[0]) ? c[0] + 'a' - 'A' : c[0]) << 8) |
2687 (mDNSIsUpperCase(c[1]) ? c[1] + 'a' - 'A' : c[1]);
2688 sum = (sum<<3) | (sum>>29);
2690 if (c[0]) sum += ((mDNSIsUpperCase(c[0]) ? c[0] + 'a' - 'A' : c[0]) << 8);
2694 mDNSexport void SetNewRData(ResourceRecord *const rr, RData *NewRData, mDNSu16 rdlength)
2699 rr->rdata = NewRData;
2700 rr->rdlength = rdlength;
2702 // Must not try to get target pointer until after updating rr->rdata
2703 target = GetRRDomainNameTarget(rr);
2704 rr->rdlength = GetRDLength(rr, mDNSfalse);
2705 rr->rdestimate = GetRDLength(rr, mDNStrue);
2706 rr->rdatahash = target ? DomainNameHashValue(target) : RDataHashValue(rr);
2709 mDNSexport const mDNSu8 *skipDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end)
2713 if (ptr < (mDNSu8*)msg || ptr >= end)
2714 { debugf("skipDomainName: Illegal ptr not within packet boundaries"); return(mDNSNULL); }
2716 while (1) // Read sequence of labels
2718 const mDNSu8 len = *ptr++; // Read length of this label
2719 if (len == 0) return(ptr); // If length is zero, that means this name is complete
2722 case 0x00: if (ptr + len >= end) // Remember: expect at least one more byte for the root label
2723 { debugf("skipDomainName: Malformed domain name (overruns packet end)"); return(mDNSNULL); }
2724 if (total + 1 + len >= MAX_DOMAIN_NAME) // Remember: expect at least one more byte for the root label
2725 { debugf("skipDomainName: Malformed domain name (more than 256 characters)"); return(mDNSNULL); }
2730 case 0x40: debugf("skipDomainName: Extended EDNS0 label types 0x%X not supported", len); return(mDNSNULL);
2731 case 0x80: debugf("skipDomainName: Illegal label length 0x%X", len); return(mDNSNULL);
2732 case 0xC0: return(ptr+1);
2737 // Routine to fetch an FQDN from the DNS message, following compression pointers if necessary.
2738 mDNSexport const mDNSu8 *getDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end,
2739 domainname *const name)
2741 const mDNSu8 *nextbyte = mDNSNULL; // Record where we got to before we started following pointers
2742 mDNSu8 *np = name->c; // Name pointer
2743 const mDNSu8 *const limit = np + MAX_DOMAIN_NAME; // Limit so we don't overrun buffer
2745 if (ptr < (mDNSu8*)msg || ptr >= end)
2746 { debugf("getDomainName: Illegal ptr not within packet boundaries"); return(mDNSNULL); }
2748 *np = 0; // Tentatively place the root label here (may be overwritten if we have more labels)
2750 while (1) // Read sequence of labels
2754 const mDNSu8 len = *ptr++; // Read length of this label
2755 if (len == 0) break; // If length is zero, that means this name is complete
2759 case 0x00: if (ptr + len >= end) // Remember: expect at least one more byte for the root label
2760 { debugf("getDomainName: Malformed domain name (overruns packet end)"); return(mDNSNULL); }
2761 if (np + 1 + len >= limit) // Remember: expect at least one more byte for the root label
2762 { debugf("getDomainName: Malformed domain name (more than 256 characters)"); return(mDNSNULL); }
2764 for (i=0; i<len; i++) *np++ = *ptr++;
2765 *np = 0; // Tentatively place the root label here (may be overwritten if we have more labels)
2768 case 0x40: debugf("getDomainName: Extended EDNS0 label types 0x%X not supported in name %##s", len, name->c);
2771 case 0x80: debugf("getDomainName: Illegal label length 0x%X in domain name %##s", len, name->c); return(mDNSNULL);
2773 case 0xC0: if (ptr >= end)
2774 { debugf("getDomainName: Malformed compression label (overruns packet end)"); return(mDNSNULL); }
2775 offset = (mDNSu16)((((mDNSu16)(len & 0x3F)) << 8) | *ptr++);
2776 if (!nextbyte) nextbyte = ptr; // Record where we got to before we started following pointers
2777 ptr = (mDNSu8 *)msg + offset;
2778 if (ptr < (mDNSu8*)msg || ptr >= end)
2779 { debugf("getDomainName: Illegal compression pointer not within packet boundaries"); return(mDNSNULL); }
2781 { debugf("getDomainName: Compression pointer must point to real label"); return(mDNSNULL); }
2786 if (nextbyte) return(nextbyte);
2790 mDNSexport const mDNSu8 *skipResourceRecord(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end)
2792 mDNSu16 pktrdlength;
2794 ptr = skipDomainName(msg, ptr, end);
2795 if (!ptr) { debugf("skipResourceRecord: Malformed RR name"); return(mDNSNULL); }
2797 if (ptr + 10 > end) { debugf("skipResourceRecord: Malformed RR -- no type/class/ttl/len!"); return(mDNSNULL); }
2798 pktrdlength = (mDNSu16)((mDNSu16)ptr[8] << 8 | ptr[9]);
2800 if (ptr + pktrdlength > end) { debugf("skipResourceRecord: RDATA exceeds end of packet"); return(mDNSNULL); }
2802 return(ptr + pktrdlength);
2805 // Sanity check whether the NSEC/NSEC3 bitmap is good
2806 mDNSlocal mDNSu8 *SanityCheckBitMap(const mDNSu8 *bmap, const mDNSu8 *end, int len)
2814 LogInfo("SanityCheckBitMap: invalid length %d", len);
2821 if (len < wlen || wlen < 1 || wlen > 32)
2823 LogInfo("SanityCheckBitMap: invalid window length %d", wlen);
2826 if (win < 0 || win >= 256)
2828 LogInfo("SanityCheckBitMap: invalid window %d", win);
2835 return (mDNSu8 *)bmap;
2838 // This function is called with "msg" when we receive a DNS message and needs to parse a single resource record
2839 // pointed to by "ptr". Some resource records like SOA, SRV are converted to host order and also expanded
2840 // (domainnames are expanded to 255 bytes) when stored in memory.
2842 // This function can also be called with "NULL" msg to parse a single resource record pointed to by ptr.
2843 // The caller can do this only if the names in the resource records are not compressed and validity of the
2844 // resource record has already been done before. DNSSEC currently uses it this way.
2845 mDNSexport mDNSBool SetRData(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *end,
2846 LargeCacheRecord *const largecr, mDNSu16 rdlength)
2848 CacheRecord *const rr = &largecr->r;
2849 RDataBody2 *const rdb = (RDataBody2 *)rr->smallrdatastorage.data;
2851 switch (rr->resrec.rrtype)
2854 if (rdlength != sizeof(mDNSv4Addr))
2856 rdb->ipv4.b[0] = ptr[0];
2857 rdb->ipv4.b[1] = ptr[1];
2858 rdb->ipv4.b[2] = ptr[2];
2859 rdb->ipv4.b[3] = ptr[3];
2865 case kDNSType_CNAME:
2870 case kDNSType_NSAP_PTR:
2871 case kDNSType_DNAME:
2874 ptr = getDomainName(msg, ptr, end, &rdb->name);
2878 AssignDomainName(&rdb->name, (domainname *)ptr);
2879 ptr += DomainNameLength(&rdb->name);
2883 debugf("SetRData: Malformed CNAME/PTR RDATA name");
2891 ptr = getDomainName(msg, ptr, end, &rdb->soa.mname);
2895 AssignDomainName(&rdb->soa.mname, (domainname *)ptr);
2896 ptr += DomainNameLength(&rdb->soa.mname);
2900 debugf("SetRData: Malformed SOA RDATA mname");
2905 ptr = getDomainName(msg, ptr, end, &rdb->soa.rname);
2909 AssignDomainName(&rdb->soa.rname, (domainname *)ptr);
2910 ptr += DomainNameLength(&rdb->soa.rname);
2914 debugf("SetRData: Malformed SOA RDATA rname");
2917 if (ptr + 0x14 != end)
2919 debugf("SetRData: Malformed SOA RDATA");
2922 rdb->soa.serial = (mDNSs32) ((mDNSs32)ptr[0x00] << 24 | (mDNSs32)ptr[0x01] << 16 | (mDNSs32)ptr[0x02] << 8 | ptr[0x03]);
2923 rdb->soa.refresh = (mDNSu32) ((mDNSu32)ptr[0x04] << 24 | (mDNSu32)ptr[0x05] << 16 | (mDNSu32)ptr[0x06] << 8 | ptr[0x07]);
2924 rdb->soa.retry = (mDNSu32) ((mDNSu32)ptr[0x08] << 24 | (mDNSu32)ptr[0x09] << 16 | (mDNSu32)ptr[0x0A] << 8 | ptr[0x0B]);
2925 rdb->soa.expire = (mDNSu32) ((mDNSu32)ptr[0x0C] << 24 | (mDNSu32)ptr[0x0D] << 16 | (mDNSu32)ptr[0x0E] << 8 | ptr[0x0F]);
2926 rdb->soa.min = (mDNSu32) ((mDNSu32)ptr[0x10] << 24 | (mDNSu32)ptr[0x11] << 16 | (mDNSu32)ptr[0x12] << 8 | ptr[0x13]);
2930 case kDNSType_HINFO:
2935 case kDNSType_DHCID:
2936 rr->resrec.rdlength = rdlength;
2937 mDNSPlatformMemCopy(rdb->data, ptr, rdlength);
2941 case kDNSType_AFSDB:
2944 // Preference + domainname
2947 rdb->mx.preference = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]);
2951 ptr = getDomainName(msg, ptr, end, &rdb->mx.exchange);
2955 AssignDomainName(&rdb->mx.exchange, (domainname *)ptr);
2956 ptr += DomainNameLength(&rdb->mx.exchange);
2960 debugf("SetRData: Malformed MX name");
2965 case kDNSType_MINFO:
2967 // Domainname + domainname
2970 ptr = getDomainName(msg, ptr, end, &rdb->rp.mbox);
2974 AssignDomainName(&rdb->rp.mbox, (domainname *)ptr);
2975 ptr += DomainNameLength(&rdb->rp.mbox);
2979 debugf("SetRData: Malformed RP mbox");
2984 ptr = getDomainName(msg, ptr, end, &rdb->rp.txt);
2988 AssignDomainName(&rdb->rp.txt, (domainname *)ptr);
2989 ptr += DomainNameLength(&rdb->rp.txt);
2993 debugf("SetRData: Malformed RP txt");
2999 // Preference + domainname + domainname
3002 rdb->px.preference = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]);
3006 ptr = getDomainName(msg, ptr, end, &rdb->px.map822);
3010 AssignDomainName(&rdb->px.map822, (domainname *)ptr);
3011 ptr += DomainNameLength(&rdb->px.map822);
3015 debugf("SetRData: Malformed PX map822");
3020 ptr = getDomainName(msg, ptr, end, &rdb->px.mapx400);
3024 AssignDomainName(&rdb->px.mapx400, (domainname *)ptr);
3025 ptr += DomainNameLength(&rdb->px.mapx400);
3029 debugf("SetRData: Malformed PX mapx400");
3035 if (rdlength != sizeof(mDNSv6Addr))
3037 mDNSPlatformMemCopy(&rdb->ipv6, ptr, sizeof(rdb->ipv6));
3041 // Priority + weight + port + domainname
3044 rdb->srv.priority = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]);
3045 rdb->srv.weight = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]);
3046 rdb->srv.port.b[0] = ptr[4];
3047 rdb->srv.port.b[1] = ptr[5];
3051 ptr = getDomainName(msg, ptr, end, &rdb->srv.target);
3055 AssignDomainName(&rdb->srv.target, (domainname *)ptr);
3056 ptr += DomainNameLength(&rdb->srv.target);
3060 debugf("SetRData: Malformed SRV RDATA name");
3065 case kDNSType_NAPTR:
3069 const mDNSu8 *orig = ptr;
3071 // Make sure the data is parseable and within the limits. DNSSEC code looks at
3072 // the domain name in the end for a valid domainname.
3074 // Fixed length: Order, preference (4 bytes)
3075 // Variable length: flags, service, regexp, domainname
3079 // Order, preference.
3081 // Parse flags, Service and Regexp
3082 // length in the first byte does not include the length byte itself
3087 LogInfo("SetRData: Malformed NAPTR flags");
3096 LogInfo("SetRData: Malformed NAPTR service");
3105 LogInfo("SetRData: Malformed NAPTR regexp");
3109 savelen = ptr - orig;
3111 // RFC 2915 states that name compression is not allowed for this field. But RFC 3597
3112 // states that for NAPTR we should decompress. We make sure that we store the full
3113 // name rather than the compressed name
3116 ptr = getDomainName(msg, ptr, end, &name);
3120 AssignDomainName(&name, (domainname *)ptr);
3121 ptr += DomainNameLength(&name);
3125 LogInfo("SetRData: Malformed NAPTR RDATA name");
3129 rr->resrec.rdlength = savelen + DomainNameLength(&name);
3130 // The uncompressed size should not exceed the limits
3131 if (rr->resrec.rdlength > MaximumRDSize)
3133 LogInfo("SetRData: Malformed NAPTR rdlength %d, rr->resrec.rdlength %d, "
3134 "bmaplen %d, name %##s", rdlength, rr->resrec.rdlength, name.c);
3137 mDNSPlatformMemCopy(rdb->data, orig, savelen);
3138 AssignDomainName((domainname *)(rdb->data + savelen), &name);
3141 case kDNSType_OPT: {
3142 mDNSu8 *dataend = rr->resrec.rdata->u.data;
3143 rdataOPT *opt = rr->resrec.rdata->u.opt;
3144 rr->resrec.rdlength = 0;
3145 while (ptr < end && (mDNSu8 *)(opt+1) < &dataend[MaximumRDSize])
3147 const rdataOPT *const currentopt = opt;
3148 if (ptr + 4 > end) { LogInfo("SetRData: OPT RDATA ptr + 4 > end"); goto fail; }
3149 opt->opt = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]);
3150 opt->optlen = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]);
3152 if (ptr + opt->optlen > end) { LogInfo("SetRData: ptr + opt->optlen > end"); goto fail; }
3156 if (opt->optlen == DNSOpt_LLQData_Space - 4)
3158 opt->u.llq.vers = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]);
3159 opt->u.llq.llqOp = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]);
3160 opt->u.llq.err = (mDNSu16)((mDNSu16)ptr[4] << 8 | ptr[5]);
3161 mDNSPlatformMemCopy(opt->u.llq.id.b, ptr+6, 8);
3162 opt->u.llq.llqlease = (mDNSu32) ((mDNSu32)ptr[14] << 24 | (mDNSu32)ptr[15] << 16 | (mDNSu32)ptr[16] << 8 | ptr[17]);
3163 if (opt->u.llq.llqlease > 0x70000000UL / mDNSPlatformOneSecond)
3164 opt->u.llq.llqlease = 0x70000000UL / mDNSPlatformOneSecond;
3169 if (opt->optlen == DNSOpt_LeaseData_Space - 4)
3171 opt->u.updatelease = (mDNSu32) ((mDNSu32)ptr[0] << 24 | (mDNSu32)ptr[1] << 16 | (mDNSu32)ptr[2] << 8 | ptr[3]);
3172 if (opt->u.updatelease > 0x70000000UL / mDNSPlatformOneSecond)
3173 opt->u.updatelease = 0x70000000UL / mDNSPlatformOneSecond;
3178 if (ValidOwnerLength(opt->optlen))
3180 opt->u.owner.vers = ptr[0];
3181 opt->u.owner.seq = ptr[1];
3182 mDNSPlatformMemCopy(opt->u.owner.HMAC.b, ptr+2, 6); // 6-byte MAC address
3183 mDNSPlatformMemCopy(opt->u.owner.IMAC.b, ptr+2, 6); // 6-byte MAC address
3184 opt->u.owner.password = zeroEthAddr;
3185 if (opt->optlen >= DNSOpt_OwnerData_ID_Wake_Space-4)
3187 mDNSPlatformMemCopy(opt->u.owner.IMAC.b, ptr+8, 6); // 6-byte MAC address
3188 // This mDNSPlatformMemCopy is safe because the ValidOwnerLength(opt->optlen) check above
3189 // ensures that opt->optlen is no more than DNSOpt_OwnerData_ID_Wake_PW6_Space - 4
3190 if (opt->optlen > DNSOpt_OwnerData_ID_Wake_Space-4)
3191 mDNSPlatformMemCopy(opt->u.owner.password.b, ptr+14, opt->optlen - (DNSOpt_OwnerData_ID_Wake_Space-4));
3197 if (opt->optlen == DNSOpt_TraceData_Space - 4)
3199 opt->u.tracer.platf = ptr[0];
3200 opt->u.tracer.mDNSv = (mDNSu32) ((mDNSu32)ptr[1] << 24 | (mDNSu32)ptr[2] << 16 | (mDNSu32)ptr[3] << 8 | ptr[4]);
3205 opt->u.tracer.platf = 0xFF;
3206 opt->u.tracer.mDNSv = 0xFFFFFFFF;
3211 ptr += currentopt->optlen;
3213 rr->resrec.rdlength = (mDNSu16)((mDNSu8*)opt - rr->resrec.rdata->u.data);
3214 if (ptr != end) { LogInfo("SetRData: Malformed OptRdata"); goto fail; }
3218 case kDNSType_NSEC: {
3222 const mDNSu8 *orig = ptr;
3227 ptr = getDomainName(msg, ptr, end, &name);
3231 AssignDomainName(&name, (domainname *)ptr);
3232 ptr += DomainNameLength(&name);
3236 LogInfo("SetRData: Malformed NSEC nextname");
3240 dlen = DomainNameLength(&name);
3242 // Multicast NSECs use name compression for this field unlike the unicast case which
3243 // does not use compression. And multicast case always succeeds in compression. So,
3244 // the rdlength includes only the compressed space in that case. So, can't
3245 // use the DomainNameLength of name to reduce the length here.
3246 len -= (ptr - orig);
3247 bmaplen = len; // Save the length of the bitmap
3249 ptr = SanityCheckBitMap(bmap, end, len);
3254 LogInfo("SetRData: Malformed NSEC length not right");
3258 // Initialize the right length here. When we call SetNewRData below which in turn calls
3259 // GetRDLength and for NSEC case, it assumes that rdlength is intitialized
3260 rr->resrec.rdlength = DomainNameLength(&name) + bmaplen;
3262 // Do we have space after the name expansion ?
3263 if (rr->resrec.rdlength > MaximumRDSize)
3265 LogInfo("SetRData: Malformed NSEC rdlength %d, rr->resrec.rdlength %d, "
3266 "bmaplen %d, name %##s", rdlength, rr->resrec.rdlength, name.c);
3269 AssignDomainName((domainname *)rdb->data, &name);
3270 mDNSPlatformMemCopy(rdb->data + dlen, bmap, bmaplen);
3273 case kDNSType_NSEC3:
3275 rdataNSEC3 *nsec3 = (rdataNSEC3 *)ptr;
3276 mDNSu8 *p = (mDNSu8 *)&nsec3->salt;
3277 int hashLength, bitmaplen;
3279 if (rdlength < NSEC3_FIXED_SIZE + 1)
3281 LogInfo("SetRData: NSEC3 too small length %d", rdlength);
3284 if (nsec3->alg != SHA1_DIGEST_TYPE)
3286 LogInfo("SetRData: nsec3 alg %d not supported", nsec3->alg);
3289 if (swap16(nsec3->iterations) > NSEC3_MAX_ITERATIONS)
3291 LogInfo("SetRData: nsec3 iteration count %d too big", swap16(nsec3->iterations));
3294 p += nsec3->saltLength;
3295 // There should at least be one byte beyond saltLength
3298 LogInfo("SetRData: nsec3 too small, at saltlength %d, p %p, end %p", nsec3->saltLength, p, end);
3301 // p is pointing at hashLength
3302 hashLength = (int)*p++;
3305 LogInfo("SetRData: hashLength zero");
3311 LogInfo("SetRData: nsec3 too small, at hashLength %d, p %p, end %p", hashLength, p, end);
3315 bitmaplen = rdlength - (int)(p - ptr);
3316 p = SanityCheckBitMap(p, end, bitmaplen);
3319 rr->resrec.rdlength = rdlength;
3320 mDNSPlatformMemCopy(rdb->data, ptr, rdlength);
3329 // The name should not be compressed. But we take the conservative approach
3330 // and uncompress the name before we store it.
3333 ptr = getDomainName(msg, ptr, end, &name);
3337 AssignDomainName(&name, (domainname *)ptr);
3338 ptr += DomainNameLength(&name);
3340 if (!ptr || ptr >= end)
3342 LogInfo("SetRData: Malformed name for TSIG/TKEY type %d", rr->resrec.rrtype);
3345 dlen = DomainNameLength(&name);
3347 rr->resrec.rdlength = dlen + rlen;
3348 if (rr->resrec.rdlength > MaximumRDSize)
3350 LogInfo("SetRData: Malformed TSIG/TKEY rdlength %d, rr->resrec.rdlength %d, "
3351 "bmaplen %d, name %##s", rdlength, rr->resrec.rdlength, name.c);
3354 AssignDomainName((domainname *)rdb->data, &name);
3355 mDNSPlatformMemCopy(rdb->data + dlen, ptr, rlen);
3358 case kDNSType_RRSIG:
3360 const mDNSu8 *sig = ptr + RRSIG_FIXED_SIZE;
3361 const mDNSu8 *orig = sig;
3363 if (rdlength < RRSIG_FIXED_SIZE + 1)
3365 LogInfo("SetRData: RRSIG too small length %d", rdlength);
3370 sig = getDomainName(msg, sig, end, &name);
3374 AssignDomainName(&name, (domainname *)sig);
3375 sig += DomainNameLength(&name);
3379 LogInfo("SetRData: Malformed RRSIG record");
3383 if ((sig - orig) != DomainNameLength(&name))
3385 LogInfo("SetRData: Malformed RRSIG record, signer name compression");
3388 // Just ensure that we have at least one byte of the signature
3391 LogInfo("SetRData: Not enough bytes for signature type %d", rr->resrec.rrtype);
3394 rr->resrec.rdlength = rdlength;
3395 mDNSPlatformMemCopy(rdb->data, ptr, rdlength);
3398 case kDNSType_DNSKEY:
3400 if (rdlength < DNSKEY_FIXED_SIZE + 1)
3402 LogInfo("SetRData: DNSKEY too small length %d", rdlength);
3405 rr->resrec.rdlength = rdlength;
3406 mDNSPlatformMemCopy(rdb->data, ptr, rdlength);
3411 if (rdlength < DS_FIXED_SIZE + 1)
3413 LogInfo("SetRData: DS too small length %d", rdlength);
3416 rr->resrec.rdlength = rdlength;
3417 mDNSPlatformMemCopy(rdb->data, ptr, rdlength);
3421 debugf("SetRData: Warning! Reading resource type %d (%s) as opaque data",
3422 rr->resrec.rrtype, DNSTypeName(rr->resrec.rrtype));
3423 // Note: Just because we don't understand the record type, that doesn't
3424 // mean we fail. The DNS protocol specifies rdlength, so we can
3425 // safely skip over unknown records and ignore them.
3426 // We also grab a binary copy of the rdata anyway, since the caller
3427 // might know how to interpret it even if we don't.
3428 rr->resrec.rdlength = rdlength;
3429 mDNSPlatformMemCopy(rdb->data, ptr, rdlength);
3437 mDNSexport const mDNSu8 *GetLargeResourceRecord(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *ptr,
3438 const mDNSu8 *end, const mDNSInterfaceID InterfaceID, mDNSu8 RecordType, LargeCacheRecord *const largecr)
3440 CacheRecord *const rr = &largecr->r;
3441 mDNSu16 pktrdlength;
3443 if (largecr == &m->rec && m->rec.r.resrec.RecordType)
3444 LogFatalError("GetLargeResourceRecord: m->rec appears to be already in use for %s", CRDisplayString(m, &m->rec.r));
3446 rr->next = mDNSNULL;
3447 rr->resrec.name = &largecr->namestorage;
3449 rr->NextInKAList = mDNSNULL;
3450 rr->TimeRcvd = m ? m->timenow : 0;
3451 rr->DelayDelivery = 0;
3452 rr->NextRequiredQuery = m ? m->timenow : 0; // Will be updated to the real value when we call SetNextCacheCheckTimeForRecord()
3453 rr->LastUsed = m ? m->timenow : 0;
3454 rr->CRActiveQuestion = mDNSNULL;
3455 rr->UnansweredQueries = 0;
3456 rr->LastUnansweredTime= 0;
3457 rr->NextInCFList = mDNSNULL;
3459 rr->resrec.InterfaceID = InterfaceID;
3460 rr->resrec.rDNSServer = mDNSNULL;
3462 ptr = getDomainName(msg, ptr, end, &largecr->namestorage); // Will bail out correctly if ptr is NULL
3463 if (!ptr) { debugf("GetLargeResourceRecord: Malformed RR name"); return(mDNSNULL); }
3464 rr->resrec.namehash = DomainNameHashValue(rr->resrec.name);
3466 if (ptr + 10 > end) { debugf("GetLargeResourceRecord: Malformed RR -- no type/class/ttl/len!"); return(mDNSNULL); }
3468 rr->resrec.rrtype = (mDNSu16) ((mDNSu16)ptr[0] << 8 | ptr[1]);
3469 rr->resrec.rrclass = (mDNSu16)(((mDNSu16)ptr[2] << 8 | ptr[3]) & kDNSClass_Mask);
3470 rr->resrec.rroriginalttl = (mDNSu32) ((mDNSu32)ptr[4] << 24 | (mDNSu32)ptr[5] << 16 | (mDNSu32)ptr[6] << 8 | ptr[7]);
3471 if (rr->resrec.rroriginalttl > 0x70000000UL / mDNSPlatformOneSecond && (mDNSs32)rr->resrec.rroriginalttl != -1)
3472 rr->resrec.rroriginalttl = 0x70000000UL / mDNSPlatformOneSecond;
3473 // Note: We don't have to adjust m->NextCacheCheck here -- this is just getting a record into memory for
3474 // us to look at. If we decide to copy it into the cache, then we'll update m->NextCacheCheck accordingly.
3475 pktrdlength = (mDNSu16)((mDNSu16)ptr[8] << 8 | ptr[9]);
3477 // If mDNS record has cache-flush bit set, we mark it unique
3478 // For uDNS records, all are implicitly deemed unique (a single DNS server is always authoritative for the entire RRSet)
3479 if (ptr[2] & (kDNSClass_UniqueRRSet >> 8) || !InterfaceID)
3480 RecordType |= kDNSRecordTypePacketUniqueMask;
3482 if (ptr + pktrdlength > end) { debugf("GetLargeResourceRecord: RDATA exceeds end of packet"); return(mDNSNULL); }
3483 end = ptr + pktrdlength; // Adjust end to indicate the end of the rdata for this resource record
3485 rr->resrec.rdata = (RData*)&rr->smallrdatastorage;
3486 rr->resrec.rdata->MaxRDLength = MaximumRDSize;
3488 if (pktrdlength > MaximumRDSize)
3490 LogInfo("GetLargeResourceRecord: %s rdata size (%d) exceeds storage (%d)",
3491 DNSTypeName(rr->resrec.rrtype), pktrdlength, rr->resrec.rdata->MaxRDLength);
3495 if (!RecordType) LogMsg("GetLargeResourceRecord: No RecordType for %##s", rr->resrec.name->c);
3497 // IMPORTANT: Any record type we understand and unpack into a structure containing domainnames needs to have corresponding
3498 // cases in SameRDataBody() and RDataHashValue() to do a semantic comparison (or checksum) of the structure instead of a blind
3499 // bitwise memory compare (or sum). This is because a domainname is a fixed size structure holding variable-length data.
3500 // Any bytes past the logical end of the name are undefined, and a blind bitwise memory compare may indicate that
3501 // two domainnames are different when semantically they are the same name and it's only the unused bytes that differ.
3502 if (rr->resrec.rrclass == kDNSQClass_ANY && pktrdlength == 0) // Used in update packets to mean "Delete An RRset" (RFC 2136)
3503 rr->resrec.rdlength = 0;
3504 else if (!SetRData(msg, ptr, end, largecr, pktrdlength))
3507 SetNewRData(&rr->resrec, mDNSNULL, 0); // Sets rdlength, rdestimate, rdatahash for us
3509 // Success! Now fill in RecordType to show this record contains valid data
3510 rr->resrec.RecordType = RecordType;
3514 // If we were unable to parse the rdata in this record, we indicate that by
3515 // returing a 'kDNSRecordTypePacketNegative' record with rdlength set to zero
3516 rr->resrec.RecordType = kDNSRecordTypePacketNegative;
3517 rr->resrec.rdlength = 0;
3518 rr->resrec.rdestimate = 0;
3519 rr->resrec.rdatahash = 0;
3523 mDNSexport const mDNSu8 *skipQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end)
3525 ptr = skipDomainName(msg, ptr, end);
3526 if (!ptr) { debugf("skipQuestion: Malformed domain name in DNS question section"); return(mDNSNULL); }
3527 if (ptr+4 > end) { debugf("skipQuestion: Malformed DNS question section -- no query type and class!"); return(mDNSNULL); }
3531 mDNSexport const mDNSu8 *getQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end, const mDNSInterfaceID InterfaceID,
3532 DNSQuestion *question)
3534 mDNSPlatformMemZero(question, sizeof(*question));
3535 question->InterfaceID = InterfaceID;
3536 if (!InterfaceID) question->TargetQID = onesID; // In DNSQuestions we use TargetQID as the indicator of whether it's unicast or multicast
3537 ptr = getDomainName(msg, ptr, end, &question->qname);
3538 if (!ptr) { debugf("Malformed domain name in DNS question section"); return(mDNSNULL); }
3539 if (ptr+4 > end) { debugf("Malformed DNS question section -- no query type and class!"); return(mDNSNULL); }
3541 question->qnamehash = DomainNameHashValue(&question->qname);
3542 question->qtype = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); // Get type
3543 question->qclass = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]); // and class
3547 mDNSexport const mDNSu8 *LocateAnswers(const DNSMessage *const msg, const mDNSu8 *const end)
3550 const mDNSu8 *ptr = msg->data;
3551 for (i = 0; i < msg->h.numQuestions && ptr; i++) ptr = skipQuestion(msg, ptr, end);
3555 mDNSexport const mDNSu8 *LocateAuthorities(const DNSMessage *const msg, const mDNSu8 *const end)
3558 const mDNSu8 *ptr = LocateAnswers(msg, end);
3559 for (i = 0; i < msg->h.numAnswers && ptr; i++) ptr = skipResourceRecord(msg, ptr, end);
3563 mDNSexport const mDNSu8 *LocateAdditionals(const DNSMessage *const msg, const mDNSu8 *const end)
3566 const mDNSu8 *ptr = LocateAuthorities(msg, end);
3567 for (i = 0; i < msg->h.numAuthorities; i++) ptr = skipResourceRecord(msg, ptr, end);
3571 mDNSexport const mDNSu8 *LocateOptRR(const DNSMessage *const msg, const mDNSu8 *const end, int minsize)
3574 const mDNSu8 *ptr = LocateAdditionals(msg, end);
3576 // Locate the OPT record.
3577 // According to RFC 2671, "One OPT pseudo-RR can be added to the additional data section of either a request or a response."
3578 // This implies that there may be *at most* one OPT record per DNS message, in the Additional Section,
3579 // but not necessarily the *last* entry in the Additional Section.
3580 for (i = 0; ptr && i < msg->h.numAdditionals; i++)
3582 if (ptr + DNSOpt_Header_Space + minsize <= end && // Make sure we have 11+minsize bytes of data
3583 ptr[0] == 0 && // Name must be root label
3584 ptr[1] == (kDNSType_OPT >> 8 ) && // rrtype OPT
3585 ptr[2] == (kDNSType_OPT & 0xFF) &&
3586 ((mDNSu16)ptr[9] << 8 | (mDNSu16)ptr[10]) >= (mDNSu16)minsize)
3589 ptr = skipResourceRecord(msg, ptr, end);
3594 // On success, GetLLQOptData returns pointer to storage within shared "m->rec";
3595 // it is caller's responsibilty to clear m->rec.r.resrec.RecordType after use
3596 // Note: An OPT RDataBody actually contains one or more variable-length rdataOPT objects packed together
3597 // The code that currently calls this assumes there's only one, instead of iterating through the set
3598 mDNSexport const rdataOPT *GetLLQOptData(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end)
3600 const mDNSu8 *ptr = LocateOptRR(msg, end, DNSOpt_LLQData_Space);
3603 ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &m->rec);
3604 if (ptr && m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative) return(&m->rec.r.resrec.rdata->u.opt[0]);
3609 // Get the lease life of records in a dynamic update
3610 mDNSexport mDNSBool GetPktLease(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, mDNSu32 *const lease)
3612 const mDNSu8 *ptr = LocateOptRR(msg, end, DNSOpt_LeaseData_Space);
3615 ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &m->rec);
3616 if (ptr && m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative && m->rec.r.resrec.rrtype == kDNSType_OPT)
3619 const rdataOPT *const e = (const rdataOPT *)&m->rec.r.resrec.rdata->u.data[m->rec.r.resrec.rdlength];
3620 for (o = &m->rec.r.resrec.rdata->u.opt[0]; o < e; o++)
3621 if (o->opt == kDNSOpt_Lease)
3623 *lease = o->u.updatelease;
3624 m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it
3628 m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it
3633 mDNSlocal const mDNSu8 *DumpRecords(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end, int count, char *label)
3636 LogInfo("%2d %s", count, label);
3637 for (i = 0; i < count && ptr; i++)
3639 // This puts a LargeCacheRecord on the stack instead of using the shared m->rec storage,
3640 // but since it's only used for debugging (and probably only on OS X, not on
3641 // embedded systems) putting a 9kB object on the stack isn't a big problem.
3642 LargeCacheRecord largecr;
3643 ptr = GetLargeResourceRecord(m, msg, ptr, end, mDNSInterface_Any, kDNSRecordTypePacketAns, &largecr);
3645 LogInfo("%2d TTL%8d %s", i, largecr.r.resrec.rroriginalttl, CRDisplayString(m, &largecr.r));
3648 LogInfo("DumpRecords: ERROR: Premature end of packet data");
3652 #define DNS_OP_Name(X) ( \
3653 (X) == kDNSFlag0_OP_StdQuery ? "" : \
3654 (X) == kDNSFlag0_OP_Iquery ? "Iquery " : \
3655 (X) == kDNSFlag0_OP_Status ? "Status " : \
3656 (X) == kDNSFlag0_OP_Unused3 ? "Unused3 " : \
3657 (X) == kDNSFlag0_OP_Notify ? "Notify " : \
3658 (X) == kDNSFlag0_OP_Update ? "Update " : \
3659 (X) == kDNSFlag0_OP_Subscribe? "Subscribe": \
3660 (X) == kDNSFlag0_OP_UnSubscribe? "UnSubscribe" : "?? " )
3662 #define DNS_RC_Name(X) ( \
3663 (X) == kDNSFlag1_RC_NoErr ? "NoErr" : \
3664 (X) == kDNSFlag1_RC_FormErr ? "FormErr" : \
3665 (X) == kDNSFlag1_RC_ServFail ? "ServFail" : \
3666 (X) == kDNSFlag1_RC_NXDomain ? "NXDomain" : \
3667 (X) == kDNSFlag1_RC_NotImpl ? "NotImpl" : \
3668 (X) == kDNSFlag1_RC_Refused ? "Refused" : \
3669 (X) == kDNSFlag1_RC_YXDomain ? "YXDomain" : \
3670 (X) == kDNSFlag1_RC_YXRRSet ? "YXRRSet" : \
3671 (X) == kDNSFlag1_RC_NXRRSet ? "NXRRSet" : \
3672 (X) == kDNSFlag1_RC_NotAuth ? "NotAuth" : \
3673 (X) == kDNSFlag1_RC_NotZone ? "NotZone" : "??" )
3675 // Note: DumpPacket expects the packet header fields in host byte order, not network byte order
3676 mDNSexport void DumpPacket(mDNS *const m, mStatus status, mDNSBool sent, char *transport,
3677 const mDNSAddr *srcaddr, mDNSIPPort srcport,
3678 const mDNSAddr *dstaddr, mDNSIPPort dstport, const DNSMessage *const msg, const mDNSu8 *const end)
3680 mDNSBool IsUpdate = ((msg->h.flags.b[0] & kDNSFlag0_OP_Mask) == kDNSFlag0_OP_Update);
3681 const mDNSu8 *ptr = msg->data;
3684 char tbuffer[64], sbuffer[64], dbuffer[64] = "";
3685 if (!status) tbuffer[mDNS_snprintf(tbuffer, sizeof(tbuffer), sent ? "Sent" : "Received" )] = 0;
3686 else tbuffer[mDNS_snprintf(tbuffer, sizeof(tbuffer), "ERROR %d %sing", status, sent ? "Send" : "Receive")] = 0;
3687 if (sent) sbuffer[mDNS_snprintf(sbuffer, sizeof(sbuffer), "port " )] = 0;
3688 else sbuffer[mDNS_snprintf(sbuffer, sizeof(sbuffer), "%#a:", srcaddr)] = 0;
3689 if (dstaddr || !mDNSIPPortIsZero(dstport))
3690 dbuffer[mDNS_snprintf(dbuffer, sizeof(dbuffer), " to %#a:%d", dstaddr, mDNSVal16(dstport))] = 0;
3692 LogInfo("-- %s %s DNS %s%s (flags %02X%02X) RCODE: %s (%d) %s%s%s%s%s%sID: %d %d bytes from %s%d%s%s --",
3694 DNS_OP_Name(msg->h.flags.b[0] & kDNSFlag0_OP_Mask),
3695 msg->h.flags.b[0] & kDNSFlag0_QR_Response ? "Response" : "Query",
3696 msg->h.flags.b[0], msg->h.flags.b[1],
3697 DNS_RC_Name(msg->h.flags.b[1] & kDNSFlag1_RC_Mask),
3698 msg->h.flags.b[1] & kDNSFlag1_RC_Mask,
3699 msg->h.flags.b[0] & kDNSFlag0_AA ? "AA " : "",
3700 msg->h.flags.b[0] & kDNSFlag0_TC ? "TC " : "",
3701 msg->h.flags.b[0] & kDNSFlag0_RD ? "RD " : "",
3702 msg->h.flags.b[1] & kDNSFlag1_RA ? "RA " : "",
3703 msg->h.flags.b[1] & kDNSFlag1_AD ? "AD " : "",
3704 msg->h.flags.b[1] & kDNSFlag1_CD ? "CD " : "",
3705 mDNSVal16(msg->h.id),
3707 sbuffer, mDNSVal16(srcport), dbuffer,
3708 (msg->h.flags.b[0] & kDNSFlag0_TC) ? " (truncated)" : ""
3711 LogInfo("%2d %s", msg->h.numQuestions, IsUpdate ? "Zone" : "Questions");
3712 for (i = 0; i < msg->h.numQuestions && ptr; i++)
3714 ptr = getQuestion(msg, ptr, end, mDNSInterface_Any, &q);
3715 if (ptr) LogInfo("%2d %##s %s", i, q.qname.c, DNSTypeName(q.qtype));
3717 ptr = DumpRecords(m, msg, ptr, end, msg->h.numAnswers, IsUpdate ? "Prerequisites" : "Answers");
3718 ptr = DumpRecords(m, msg, ptr, end, msg->h.numAuthorities, IsUpdate ? "Updates" : "Authorities");
3719 DumpRecords(m, msg, ptr, end, msg->h.numAdditionals, "Additionals");
3720 LogInfo("--------------");
3723 // ***************************************************************************
3724 #if COMPILER_LIKES_PRAGMA_MARK
3726 #pragma mark - Packet Sending Functions
3730 // Run the unit test of mDNSSendDNSMessage
3731 UNITTEST_SENDDNSMESSAGE
3733 // Stub definition of TCPSocket_struct so we can access flags field. (Rest of TCPSocket_struct is platform-dependent.)
3734 struct TCPSocket_struct { TCPSocketFlags flags; /* ... */ };
3735 // Stub definition of UDPSocket_struct so we can access port field. (Rest of UDPSocket_struct is platform-dependent.)
3736 struct UDPSocket_struct { mDNSIPPort port; /* ... */ };
3738 // Note: When we sign a DNS message using DNSDigest_SignMessage(), the current real-time clock value is used, which
3739 // is why we generally defer signing until we send the message, to ensure the signature is as fresh as possible.
3740 mDNSexport mStatus mDNSSendDNSMessage(mDNS *const m, DNSMessage *const msg, mDNSu8 *end,
3741 mDNSInterfaceID InterfaceID, UDPSocket *src, const mDNSAddr *dst,
3742 mDNSIPPort dstport, TCPSocket *sock, DomainAuthInfo *authInfo,
3743 mDNSBool useBackgroundTrafficClass)
3745 mStatus status = mStatus_NoError;
3746 const mDNSu16 numAdditionals = msg->h.numAdditionals;
3748 mDNSu8 *limit = msg->data + AbsoluteMaxDNSMessageData;
3750 #if APPLE_OSX_mDNSResponder
3751 // maintain outbound packet statistics
3752 if (mDNSOpaque16IsZero(msg->h.id))
3753 m->MulticastPacketsSent++;
3755 m->UnicastPacketsSent++;
3756 #endif // APPLE_OSX_mDNSResponder
3758 // Zero-length message data is okay (e.g. for a DNS Update ack, where all we need is an ID and an error code
3759 if (end < msg->data || end - msg->data > AbsoluteMaxDNSMessageData)
3761 LogMsg("mDNSSendDNSMessage: invalid message %p %p %d", msg->data, end, end - msg->data);
3762 return mStatus_BadParamErr;
3765 newend = putHINFO(m, msg, end, authInfo, limit);
3766 if (!newend) LogMsg("mDNSSendDNSMessage: putHINFO failed msg %p end %p, limit %p", msg->data, end, limit); // Not fatal
3769 // Put all the integer values in IETF byte-order (MSB first, LSB second)
3770 SwapDNSHeaderBytes(msg);
3772 if (authInfo) DNSDigest_SignMessage(msg, &end, authInfo, 0); // DNSDigest_SignMessage operates on message in network byte order
3773 if (!end) { LogMsg("mDNSSendDNSMessage: DNSDigest_SignMessage failed"); status = mStatus_NoMemoryErr; }
3776 // Send the packet on the wire
3778 status = mDNSPlatformSendUDP(m, msg, end, InterfaceID, src, dst, dstport, useBackgroundTrafficClass);
3781 mDNSu16 msglen = (mDNSu16)(end - (mDNSu8 *)msg);
3782 mDNSu8 lenbuf[2] = { (mDNSu8)(msglen >> 8), (mDNSu8)(msglen & 0xFF) };
3786 // Try to send them in one packet if we can allocate enough memory
3787 buf = mDNSPlatformMemAllocate(msglen + 2);
3792 mDNSPlatformMemCopy(buf+2, msg, msglen);
3793 nsent = mDNSPlatformWriteTCP(sock, buf, msglen+2);
3794 if (nsent != (msglen + 2))
3796 LogMsg("mDNSSendDNSMessage: write message failed %d/%d", nsent, msglen);
3797 status = mStatus_ConnFailed;
3799 mDNSPlatformMemFree(buf);
3803 nsent = mDNSPlatformWriteTCP(sock, (char*)lenbuf, 2);
3806 LogMsg("mDNSSendDNSMessage: write msg length failed %d/%d", nsent, 2);
3807 status = mStatus_ConnFailed;
3811 nsent = mDNSPlatformWriteTCP(sock, (char *)msg, msglen);
3812 if (nsent != msglen)
3814 LogMsg("mDNSSendDNSMessage: write msg body failed %d/%d", nsent, msglen);
3815 status = mStatus_ConnFailed;
3822 // Swap the integer values back the way they were (remember that numAdditionals may have been changed by putHINFO and/or SignMessage)
3823 SwapDNSHeaderBytes(msg);
3825 // Dump the packet with the HINFO and TSIG
3826 if (mDNS_PacketLoggingEnabled && !mDNSOpaque16IsZero(msg->h.id))
3827 DumpPacket(m, status, mDNStrue, sock && (sock->flags & kTCPSocketFlags_UseTLS) ? "TLS" : sock ? "TCP" : "UDP", mDNSNULL, src ? src->port : MulticastDNSPort, dst, dstport, msg, end);
3829 // put the number of additionals back the way it was
3830 msg->h.numAdditionals = numAdditionals;
3836 // ***************************************************************************
3837 #if COMPILER_LIKES_PRAGMA_MARK
3839 #pragma mark - RR List Management & Task Management
3842 mDNSexport void mDNS_Lock_(mDNS *const m, const char * const functionname)
3844 // MUST grab the platform lock FIRST!
3845 mDNSPlatformLock(m);
3847 // Normally, mDNS_reentrancy is zero and so is mDNS_busy
3848 // However, when we call a client callback mDNS_busy is one, and we increment mDNS_reentrancy too
3849 // If that client callback does mDNS API calls, mDNS_reentrancy and mDNS_busy will both be one
3850 // If mDNS_busy != mDNS_reentrancy that's a bad sign
3851 if (m->mDNS_busy != m->mDNS_reentrancy)
3852 LogFatalError("%s: mDNS_Lock: Locking failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", functionname, m->mDNS_busy, m->mDNS_reentrancy);
3854 // If this is an initial entry into the mDNSCore code, set m->timenow
3855 // else, if this is a re-entrant entry into the mDNSCore code, m->timenow should already be set
3856 if (m->mDNS_busy == 0)
3859 LogMsg("%s: mDNS_Lock: m->timenow already set (%ld/%ld)", functionname, m->timenow, mDNS_TimeNow_NoLock(m));
3860 m->timenow = mDNS_TimeNow_NoLock(m);
3861 if (m->timenow == 0) m->timenow = 1;
3863 else if (m->timenow == 0)
3865 LogMsg("%s: mDNS_Lock: m->mDNS_busy is %ld but m->timenow not set", functionname, m->mDNS_busy);
3866 m->timenow = mDNS_TimeNow_NoLock(m);
3867 if (m->timenow == 0) m->timenow = 1;
3870 if (m->timenow_last - m->timenow > 0)
3872 m->timenow_adjust += m->timenow_last - m->timenow;
3873 LogMsg("%s: mDNSPlatformRawTime went backwards by %ld ticks; setting correction factor to %ld", functionname, m->timenow_last - m->timenow, m->timenow_adjust);
3874 m->timenow = m->timenow_last;
3876 m->timenow_last = m->timenow;
3878 // Increment mDNS_busy so we'll recognise re-entrant calls
3882 mDNSlocal AuthRecord *AnyLocalRecordReady(const mDNS *const m)
3885 for (rr = m->NewLocalRecords; rr; rr = rr->next)
3886 if (LocalRecordReady(rr)) return rr;
3890 mDNSlocal mDNSs32 GetNextScheduledEvent(const mDNS *const m)
3892 mDNSs32 e = m->timenow + FutureTime;
3893 if (m->mDNSPlatformStatus != mStatus_NoError) return(e);
3894 if (m->NewQuestions)
3896 if (m->NewQuestions->DelayAnswering) e = m->NewQuestions->DelayAnswering;
3897 else return(m->timenow);
3899 if (m->NewLocalOnlyQuestions) return(m->timenow);
3900 if (m->NewLocalRecords && AnyLocalRecordReady(m)) return(m->timenow);
3901 if (m->NewLocalOnlyRecords) return(m->timenow);
3902 if (m->SPSProxyListChanged) return(m->timenow);
3903 if (m->LocalRemoveEvents) return(m->timenow);
3905 #ifndef UNICAST_DISABLED
3906 if (e - m->NextuDNSEvent > 0) e = m->NextuDNSEvent;
3907 if (e - m->NextScheduledNATOp > 0) e = m->NextScheduledNATOp;
3908 if (m->NextSRVUpdate && e - m->NextSRVUpdate > 0) e = m->NextSRVUpdate;
3911 if (e - m->NextCacheCheck > 0) e = m->NextCacheCheck;
3912 if (e - m->NextScheduledSPS > 0) e = m->NextScheduledSPS;
3913 if (e - m->NextScheduledKA > 0) e = m->NextScheduledKA;
3915 #if BONJOUR_ON_DEMAND
3916 if (m->NextBonjourDisableTime && (e - m->NextBonjourDisableTime > 0)) e = m->NextBonjourDisableTime;
3917 #endif // BONJOUR_ON_DEMAND
3919 // NextScheduledSPRetry only valid when DelaySleep not set
3920 if (!m->DelaySleep && m->SleepLimit && e - m->NextScheduledSPRetry > 0) e = m->NextScheduledSPRetry;
3921 if (m->DelaySleep && e - m->DelaySleep > 0) e = m->DelaySleep;
3923 if (m->SuppressSending)
3925 if (e - m->SuppressSending > 0) e = m->SuppressSending;
3929 if (e - m->NextScheduledQuery > 0) e = m->NextScheduledQuery;
3930 if (e - m->NextScheduledProbe > 0) e = m->NextScheduledProbe;
3931 if (e - m->NextScheduledResponse > 0) e = m->NextScheduledResponse;
3933 if (e - m->NextScheduledStopTime > 0) e = m->NextScheduledStopTime;
3935 if (m->NextBLEServiceTime && (e - m->NextBLEServiceTime > 0)) e = m->NextBLEServiceTime;
3940 #define LogTSE TSE++,LogMsg
3942 mDNSexport void ShowTaskSchedulingError(mDNS *const m)
3948 LogMsg("Task Scheduling Error: *** Continuously busy for more than a second");
3950 // Note: To accurately diagnose *why* we're busy, the debugging code here needs to mirror the logic in GetNextScheduledEvent above
3952 if (m->NewQuestions && (!m->NewQuestions->DelayAnswering || m->timenow - m->NewQuestions->DelayAnswering >= 0))
3953 LogTSE("Task Scheduling Error: NewQuestion %##s (%s)",
3954 m->NewQuestions->qname.c, DNSTypeName(m->NewQuestions->qtype));
3956 if (m->NewLocalOnlyQuestions)
3957 LogTSE("Task Scheduling Error: NewLocalOnlyQuestions %##s (%s)",
3958 m->NewLocalOnlyQuestions->qname.c, DNSTypeName(m->NewLocalOnlyQuestions->qtype));
3960 if (m->NewLocalRecords)
3962 rr = AnyLocalRecordReady(m);
3963 if (rr) LogTSE("Task Scheduling Error: NewLocalRecords %s", ARDisplayString(m, rr));
3966 if (m->NewLocalOnlyRecords) LogTSE("Task Scheduling Error: NewLocalOnlyRecords");
3968 if (m->SPSProxyListChanged) LogTSE("Task Scheduling Error: SPSProxyListChanged");
3970 if (m->LocalRemoveEvents) LogTSE("Task Scheduling Error: LocalRemoveEvents");
3972 #ifndef UNICAST_DISABLED
3973 if (m->timenow - m->NextuDNSEvent >= 0)
3974 LogTSE("Task Scheduling Error: m->NextuDNSEvent %d", m->timenow - m->NextuDNSEvent);
3975 if (m->timenow - m->NextScheduledNATOp >= 0)
3976 LogTSE("Task Scheduling Error: m->NextScheduledNATOp %d", m->timenow - m->NextScheduledNATOp);
3977 if (m->NextSRVUpdate && m->timenow - m->NextSRVUpdate >= 0)
3978 LogTSE("Task Scheduling Error: m->NextSRVUpdate %d", m->timenow - m->NextSRVUpdate);
3981 if (m->timenow - m->NextCacheCheck >= 0)
3982 LogTSE("Task Scheduling Error: m->NextCacheCheck %d", m->timenow - m->NextCacheCheck);
3983 if (m->timenow - m->NextScheduledSPS >= 0)
3984 LogTSE("Task Scheduling Error: m->NextScheduledSPS %d", m->timenow - m->NextScheduledSPS);
3985 if (m->timenow - m->NextScheduledKA >= 0)
3986 LogTSE("Task Scheduling Error: m->NextScheduledKA %d", m->timenow - m->NextScheduledKA);
3987 if (!m->DelaySleep && m->SleepLimit && m->timenow - m->NextScheduledSPRetry >= 0)
3988 LogTSE("Task Scheduling Error: m->NextScheduledSPRetry %d", m->timenow - m->NextScheduledSPRetry);
3989 if (m->DelaySleep && m->timenow - m->DelaySleep >= 0)
3990 LogTSE("Task Scheduling Error: m->DelaySleep %d", m->timenow - m->DelaySleep);
3992 if (m->SuppressSending && m->timenow - m->SuppressSending >= 0)
3993 LogTSE("Task Scheduling Error: m->SuppressSending %d", m->timenow - m->SuppressSending);
3994 if (m->timenow - m->NextScheduledQuery >= 0)
3995 LogTSE("Task Scheduling Error: m->NextScheduledQuery %d", m->timenow - m->NextScheduledQuery);
3996 if (m->timenow - m->NextScheduledProbe >= 0)
3997 LogTSE("Task Scheduling Error: m->NextScheduledProbe %d", m->timenow - m->NextScheduledProbe);
3998 if (m->timenow - m->NextScheduledResponse >= 0)
3999 LogTSE("Task Scheduling Error: m->NextScheduledResponse %d", m->timenow - m->NextScheduledResponse);
4000 if (m->timenow - m->NextScheduledStopTime >= 0)
4001 LogTSE("Task Scheduling Error: m->NextScheduledStopTime %d", m->timenow - m->NextScheduledStopTime);
4003 if (m->timenow - m->NextScheduledEvent >= 0)
4004 LogTSE("Task Scheduling Error: m->NextScheduledEvent %d", m->timenow - m->NextScheduledEvent);
4006 if (m->NetworkChanged && m->timenow - m->NetworkChanged >= 0)
4007 LogTSE("Task Scheduling Error: NetworkChanged %d", m->timenow - m->NetworkChanged);
4009 if (!TSE) LogMsg("Task Scheduling Error: *** No likely causes identified");
4010 else LogMsg("Task Scheduling Error: *** %d potential cause%s identified (significant only if the same cause consistently appears)", TSE, TSE > 1 ? "s" : "");
4015 mDNSexport void mDNS_Unlock_(mDNS *const m, const char *const functionname)
4017 // Decrement mDNS_busy
4020 // Check for locking failures
4021 if (m->mDNS_busy != m->mDNS_reentrancy)
4022 LogFatalError("%s: mDNS_Unlock: Locking failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", functionname, m->mDNS_busy, m->mDNS_reentrancy);
4024 // If this is a final exit from the mDNSCore code, set m->NextScheduledEvent and clear m->timenow
4025 if (m->mDNS_busy == 0)
4027 m->NextScheduledEvent = GetNextScheduledEvent(m);
4028 if (m->timenow == 0) LogMsg("%s: mDNS_Unlock: ERROR! m->timenow aready zero", functionname);
4032 // MUST release the platform lock LAST!
4033 mDNSPlatformUnlock(m);
4036 // ***************************************************************************
4037 #if COMPILER_LIKES_PRAGMA_MARK
4039 #pragma mark - Specialized mDNS version of vsnprintf
4042 static const struct mDNSprintf_format
4044 unsigned leftJustify : 1;
4045 unsigned forceSign : 1;
4046 unsigned zeroPad : 1;
4047 unsigned havePrecision : 1;
4051 char sign; // +, - or space
4052 unsigned int fieldWidth;
4053 unsigned int precision;
4054 } mDNSprintf_format_default = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
4056 mDNSexport mDNSu32 mDNS_vsnprintf(char *sbuffer, mDNSu32 buflen, const char *fmt, va_list arg)
4058 mDNSu32 nwritten = 0;
4060 if (buflen == 0) return(0);
4061 buflen--; // Pre-reserve one space in the buffer for the terminating null
4062 if (buflen == 0) goto exit;
4064 for (c = *fmt; c != 0; c = *++fmt)
4069 *sbuffer++ = (char)c;
4070 if (++nwritten >= buflen) goto exit;
4074 unsigned int i=0, j;
4075 // The mDNS Vsprintf Argument Conversion Buffer is used as a temporary holding area for
4076 // generating decimal numbers, hexdecimal numbers, IP addresses, domain name strings, etc.
4077 // The size needs to be enough for a 256-byte domain name plus some error text.
4078 #define mDNS_VACB_Size 300
4079 char mDNS_VACB[mDNS_VACB_Size];
4080 #define mDNS_VACB_Lim (&mDNS_VACB[mDNS_VACB_Size])
4081 #define mDNS_VACB_Remain(s) ((mDNSu32)(mDNS_VACB_Lim - s))
4082 char *s = mDNS_VACB_Lim, *digits;
4083 struct mDNSprintf_format F = mDNSprintf_format_default;
4085 while (1) // decode flags
4088 if (c == '-') F.leftJustify = 1;
4089 else if (c == '+') F.forceSign = 1;
4090 else if (c == ' ') F.sign = ' ';
4091 else if (c == '#') F.altForm++;
4092 else if (c == '0') F.zeroPad = 1;
4096 if (c == '*') // decode field width
4098 int f = va_arg(arg, int);
4099 if (f < 0) { f = -f; F.leftJustify = 1; }
4100 F.fieldWidth = (unsigned int)f;
4105 for (; c >= '0' && c <= '9'; c = *++fmt)
4106 F.fieldWidth = (10 * F.fieldWidth) + (c - '0');
4109 if (c == '.') // decode precision
4111 if ((c = *++fmt) == '*')
4112 { F.precision = va_arg(arg, unsigned int); c = *++fmt; }
4113 else for (; c >= '0' && c <= '9'; c = *++fmt)
4114 F.precision = (10 * F.precision) + (c - '0');
4115 F.havePrecision = 1;
4118 if (F.leftJustify) F.zeroPad = 0;
4121 switch (c) // perform appropriate conversion
4123 case 'h': F.hSize = 1; c = *++fmt; goto conv;
4124 case 'l': // fall through
4125 case 'L': F.lSize = 1; c = *++fmt; goto conv;
4127 case 'i': if (F.lSize) n = (unsigned long)va_arg(arg, long);
4128 else n = (unsigned long)va_arg(arg, int);
4129 if (F.hSize) n = (short) n;
4130 if ((long) n < 0) { n = (unsigned long)-(long)n; F.sign = '-'; }
4131 else if (F.forceSign) F.sign = '+';
4133 case 'u': if (F.lSize) n = va_arg(arg, unsigned long);
4134 else n = va_arg(arg, unsigned int);
4135 if (F.hSize) n = (unsigned short) n;
4138 decimal: if (!F.havePrecision)
4142 F.precision = F.fieldWidth;
4143 if (F.sign) --F.precision;
4145 if (F.precision < 1) F.precision = 1;
4147 if (F.precision > mDNS_VACB_Size - 1)
4148 F.precision = mDNS_VACB_Size - 1;
4149 for (i = 0; n; n /= 10, i++) *--s = (char)(n % 10 + '0');
4150 for (; i < F.precision; i++) *--s = '0';
4151 if (F.sign) { *--s = F.sign; i++; }
4154 case 'o': if (F.lSize) n = va_arg(arg, unsigned long);
4155 else n = va_arg(arg, unsigned int);
4156 if (F.hSize) n = (unsigned short) n;
4157 if (!F.havePrecision)
4159 if (F.zeroPad) F.precision = F.fieldWidth;
4160 if (F.precision < 1) F.precision = 1;
4162 if (F.precision > mDNS_VACB_Size - 1)
4163 F.precision = mDNS_VACB_Size - 1;
4164 for (i = 0; n; n /= 8, i++) *--s = (char)(n % 8 + '0');
4165 if (F.altForm && i && *s != '0') { *--s = '0'; i++; }
4166 for (; i < F.precision; i++) *--s = '0';
4170 unsigned char *a = va_arg(arg, unsigned char *);
4171 if (!a) { static char emsg[] = "<<NULL>>"; s = emsg; i = sizeof(emsg)-1; }
4174 s = mDNS_VACB; // Adjust s to point to the start of the buffer, not the end
4177 mDNSAddr *ip = (mDNSAddr*)a;
4180 case mDNSAddrType_IPv4: F.precision = 4; a = (unsigned char *)&ip->ip.v4; break;
4181 case mDNSAddrType_IPv6: F.precision = 16; a = (unsigned char *)&ip->ip.v6; break;
4182 default: F.precision = 0; break;
4185 if (F.altForm && !F.precision)
4186 i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "«ZERO ADDRESS»");
4187 else switch (F.precision)
4189 case 4: i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "%d.%d.%d.%d",
4190 a[0], a[1], a[2], a[3]); break;
4191 case 6: i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "%02X:%02X:%02X:%02X:%02X:%02X",
4192 a[0], a[1], a[2], a[3], a[4], a[5]); break;
4193 case 16: i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB),
4194 "%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X",
4195 a[0x0], a[0x1], a[0x2], a[0x3], a[0x4], a[0x5], a[0x6], a[0x7],
4196 a[0x8], a[0x9], a[0xA], a[0xB], a[0xC], a[0xD], a[0xE], a[0xF]); break;
4197 default: i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "%s", "<< ERROR: Must specify"
4198 " address size (i.e. %.4a=IPv4, %.6a=Ethernet, %.16a=IPv6) >>"); break;
4204 case 'p': F.havePrecision = F.lSize = 1;
4205 F.precision = sizeof(void*) * 2; // 8 characters on 32-bit; 16 characters on 64-bit
4206 case 'X': digits = "0123456789ABCDEF";
4208 case 'x': digits = "0123456789abcdef";
4209 hexadecimal: if (F.lSize) n = va_arg(arg, unsigned long);
4210 else n = va_arg(arg, unsigned int);
4211 if (F.hSize) n = (unsigned short) n;
4212 if (!F.havePrecision)
4216 F.precision = F.fieldWidth;
4217 if (F.altForm) F.precision -= 2;
4219 if (F.precision < 1) F.precision = 1;
4221 if (F.precision > mDNS_VACB_Size - 1)
4222 F.precision = mDNS_VACB_Size - 1;
4223 for (i = 0; n; n /= 16, i++) *--s = digits[n % 16];
4224 for (; i < F.precision; i++) *--s = '0';
4225 if (F.altForm) { *--s = (char)c; *--s = '0'; i += 2; }
4228 case 'c': *--s = (char)va_arg(arg, int); i = 1; break;
4230 case 's': s = va_arg(arg, char *);
4231 if (!s) { static char emsg[] = "<<NULL>>"; s = emsg; i = sizeof(emsg)-1; }
4232 else switch (F.altForm)
4235 if (!F.havePrecision) // C string
4239 while ((i < F.precision) && s[i]) i++;
4240 // Make sure we don't truncate in the middle of a UTF-8 character
4241 // If last character we got was any kind of UTF-8 multi-byte character,
4242 // then see if we have to back up.
4243 // This is not as easy as the similar checks below, because
4244 // here we can't assume it's safe to examine the *next* byte, so we
4245 // have to confine ourselves to working only backwards in the string.
4246 j = i; // Record where we got to
4247 // Now, back up until we find first non-continuation-char
4248 while (i>0 && (s[i-1] & 0xC0) == 0x80) i--;
4249 // Now s[i-1] is the first non-continuation-char
4250 // and (j-i) is the number of continuation-chars we found
4251 if (i>0 && (s[i-1] & 0xC0) == 0xC0) // If we found a start-char
4253 i--; // Tentatively eliminate this start-char as well
4254 // Now (j-i) is the number of characters we're considering eliminating.
4255 // To be legal UTF-8, the start-char must contain (j-i) one-bits,
4256 // followed by a zero bit. If we shift it right by (7-(j-i)) bits
4257 // (with sign extension) then the result has to be 0xFE.
4258 // If this is right, then we reinstate the tentatively eliminated bytes.
4259 if (((j-i) < 7) && (((s[i] >> (7-(j-i))) & 0xFF) == 0xFE)) i = j;
4263 case 1: i = (unsigned char) *s++; break; // Pascal string
4264 case 2: { // DNS label-sequence name
4265 unsigned char *a = (unsigned char *)s;
4266 s = mDNS_VACB; // Adjust s to point to the start of the buffer, not the end
4267 if (*a == 0) *s++ = '.'; // Special case for root DNS name
4272 { s += mDNS_snprintf(s, mDNS_VACB_Remain(s), "<<INVALID LABEL LENGTH %u>>", *a); break; }
4273 if (s + *a >= &mDNS_VACB[254])
4274 { s += mDNS_snprintf(s, mDNS_VACB_Remain(s), "<<NAME TOO LONG>>"); break; }
4275 // Need to use ConvertDomainLabelToCString to do proper escaping here,
4276 // so it's clear what's a literal dot and what's a label separator
4277 ConvertDomainLabelToCString((domainlabel*)a, buf);
4278 s += mDNS_snprintf(s, mDNS_VACB_Remain(s), "%s.", buf);
4281 i = (mDNSu32)(s - mDNS_VACB);
4282 s = mDNS_VACB; // Reset s back to the start of the buffer
4286 // Make sure we don't truncate in the middle of a UTF-8 character (see similar comment below)
4287 if (F.havePrecision && i > F.precision)
4288 { i = F.precision; while (i>0 && (s[i] & 0xC0) == 0x80) i--;}
4291 case 'n': s = va_arg(arg, char *);
4292 if (F.hSize) *(short *) s = (short)nwritten;
4293 else if (F.lSize) *(long *) s = (long)nwritten;
4294 else *(int *) s = (int)nwritten;
4297 default: s = mDNS_VACB;
4298 i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "<<UNKNOWN FORMAT CONVERSION CODE %%%c>>", c);
4300 case '%': *sbuffer++ = (char)c;
4301 if (++nwritten >= buflen) goto exit;
4305 if (i < F.fieldWidth && !F.leftJustify) // Pad on the left
4308 if (++nwritten >= buflen) goto exit;
4309 } while (i < --F.fieldWidth);
4311 // Make sure we don't truncate in the middle of a UTF-8 character.
4312 // Note: s[i] is the first eliminated character; i.e. the next character *after* the last character of the
4313 // allowed output. If s[i] is a UTF-8 continuation character, then we've cut a unicode character in half,
4314 // so back up 'i' until s[i] is no longer a UTF-8 continuation character. (if the input was proprly
4315 // formed, s[i] will now be the UTF-8 start character of the multi-byte character we just eliminated).
4316 if (i > buflen - nwritten)
4317 { i = buflen - nwritten; while (i>0 && (s[i] & 0xC0) == 0x80) i--;}
4318 for (j=0; j<i; j++) *sbuffer++ = *s++; // Write the converted result
4320 if (nwritten >= buflen) goto exit;
4322 for (; i < F.fieldWidth; i++) // Pad on the right
4325 if (++nwritten >= buflen) goto exit;
4334 mDNSexport mDNSu32 mDNS_snprintf(char *sbuffer, mDNSu32 buflen, const char *fmt, ...)
4340 length = mDNS_vsnprintf(sbuffer, buflen, fmt, ptr);