1 /* -*- Mode: C; tab-width: 4 -*-
2 *
3 * Copyright (c) 2002-2004 Apple Computer, Inc. All rights reserved.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 * Formatting notes:
18 * This code follows the "Whitesmiths style" C indentation rules. Plenty of discussion
19 * on C indentation can be found on the web, such as <http://www.kafejo.com/komp/1tbs.htm>,
20 * but for the sake of brevity here I will say just this: Curly braces are not syntactially
21 * part of an "if" statement; they are the beginning and ending markers of a compound statement;
22 * therefore common sense dictates that if they are part of a compound statement then they
23 * should be indented to the same level as everything else in that compound statement.
24 * Indenting curly braces at the same level as the "if" implies that curly braces are
25 * part of the "if", which is false. (This is as misleading as people who write "char* x,y;"
26 * thinking that variables x and y are both of type "char*" -- and anyone who doesn't
27 * understand why variable y is not of type "char*" just proves the point that poor code
28 * layout leads people to unfortunate misunderstandings about how the C language really works.)
29 */
30
31 //*************************************************************************************************************
32 // Incorporate mDNS.c functionality
33
34 // We want to use much of the functionality provided by "mDNS.c",
35 // except we'll steal the packets that would be sent to normal mDNSCoreReceive() routine
36 #define mDNSCoreReceive __NOT__mDNSCoreReceive__NOT__
37 #include "mDNS.c"
38 #undef mDNSCoreReceive
39
40 //*************************************************************************************************************
41 // Headers
42
43 #include <stdio.h> // For printf()
44 #include <stdlib.h> // For malloc()
45 #include <string.h> // For strrchr(), strcmp()
46 #include <time.h> // For "struct tm" etc.
47 #include <signal.h> // For SIGINT, SIGTERM
48 #if defined(WIN32)
49 // Both mDNS.c and mDNSWin32.h declare UDPSocket_struct type resulting in a compile-time error, so
50 // trick the compiler when including mDNSWin32.h
51 # define UDPSocket_struct _UDPSocket_struct
52 # include <mDNSEmbeddedAPI.h>
53 # include <mDNSWin32.h>
54 # include <PosixCompat.h>
55 # define IFNAMSIZ 256
56 static HANDLE gStopEvent = INVALID_HANDLE_VALUE;
ConsoleControlHandler(DWORD inControlEvent)57 static BOOL WINAPI ConsoleControlHandler( DWORD inControlEvent ) { SetEvent( gStopEvent ); return TRUE; }
setlinebuf(FILE * fp)58 void setlinebuf( FILE * fp ) {}
59 #else
60 # include <netdb.h> // For gethostbyname()
61 # include <sys/socket.h> // For AF_INET, AF_INET6, etc.
62 # include <net/if.h> // For IF_NAMESIZE
63 # include <netinet/in.h> // For INADDR_NONE
64 # include <arpa/inet.h> // For inet_addr()
65 # include "mDNSPosix.h" // Defines the specific types needed to run mDNS on this platform
66 #endif
67 #include "ExampleClientApp.h"
68
69 //*************************************************************************************************************
70 // Types and structures
71
72 enum
73 {
74 // Primitive operations
75 OP_probe = 0,
76 OP_goodbye = 1,
77
78 // These are meta-categories;
79 // Query and Answer operations are actually subdivided into two classes:
80 // Browse query/answer and
81 // Resolve query/answer
82 OP_query = 2,
83 OP_answer = 3,
84
85 // The "Browse" variants of query/answer
86 OP_browsegroup = 2,
87 OP_browseq = 2,
88 OP_browsea = 3,
89
90 // The "Resolve" variants of query/answer
91 OP_resolvegroup = 4,
92 OP_resolveq = 4,
93 OP_resolvea = 5,
94
95 OP_NumTypes = 6
96 };
97
98 typedef struct ActivityStat_struct ActivityStat;
99 struct ActivityStat_struct
100 {
101 ActivityStat *next;
102 domainname srvtype;
103 int printed;
104 int totalops;
105 int stat[OP_NumTypes];
106 };
107
108 typedef struct FilterList_struct FilterList;
109 struct FilterList_struct
110 {
111 FilterList *next;
112 mDNSAddr FilterAddr;
113 };
114
115 //*************************************************************************************************************
116 // Constants
117
118 #define kReportTopServices 15
119 #define kReportTopHosts 15
120
121 //*************************************************************************************************************
122 // Globals
123
124 mDNS mDNSStorage; // mDNS core uses this to store its globals
125 static mDNS_PlatformSupport PlatformStorage; // Stores this platform's globals
126 mDNSexport const char ProgramName[] = "mDNSNetMonitor";
127
128 struct timeval tv_start, tv_end, tv_interval;
129 static int FilterInterface = 0;
130 static FilterList *Filters;
131 #define ExactlyOneFilter (Filters && !Filters->next)
132
133 static int NumPktQ, NumPktL, NumPktR, NumPktB; // Query/Legacy/Response/Bad
134 static int NumProbes, NumGoodbyes, NumQuestions, NumLegacy, NumAnswers, NumAdditionals;
135
136 static ActivityStat *stats;
137
138 #define OPBanner "Total Ops Probe Goodbye BrowseQ BrowseA ResolveQ ResolveA"
139
140 //*************************************************************************************************************
141 // Utilities
142
143 // Special version of printf that knows how to print IP addresses, DNS-format name strings, etc.
144 mDNSlocal mDNSu32 mprintf(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2);
mprintf(const char * format,...)145 mDNSlocal mDNSu32 mprintf(const char *format, ...)
146 {
147 mDNSu32 length;
148 unsigned char buffer[512];
149 va_list ptr;
150 va_start(ptr,format);
151 length = mDNS_vsnprintf((char *)buffer, sizeof(buffer), format, ptr);
152 va_end(ptr);
153 printf("%s", buffer);
154 return(length);
155 }
156
157 //*************************************************************************************************************
158 // Host Address List
159 //
160 // Would benefit from a hash
161
162 typedef enum
163 {
164 HostPkt_Q = 0, // Query
165 HostPkt_L = 1, // Legacy Query
166 HostPkt_R = 2, // Response
167 HostPkt_B = 3, // Bad
168 HostPkt_NumTypes = 4
169 } HostPkt_Type;
170
171 typedef struct
172 {
173 mDNSAddr addr;
174 unsigned long pkts[HostPkt_NumTypes];
175 unsigned long totalops;
176 unsigned long stat[OP_NumTypes];
177 domainname hostname;
178 domainname revname;
179 UTF8str255 HIHardware;
180 UTF8str255 HISoftware;
181 mDNSu32 NumQueries;
182 mDNSs32 LastQuery;
183 } HostEntry;
184
185 #define HostEntryTotalPackets(H) ((H)->pkts[HostPkt_Q] + (H)->pkts[HostPkt_L] + (H)->pkts[HostPkt_R] + (H)->pkts[HostPkt_B])
186
187 typedef struct
188 {
189 long num;
190 long max;
191 HostEntry *hosts;
192 } HostList;
193
194 static HostList IPv4HostList = { 0, 0, 0 };
195 static HostList IPv6HostList = { 0, 0, 0 };
196
FindHost(const mDNSAddr * addr,HostList * list)197 mDNSlocal HostEntry *FindHost(const mDNSAddr *addr, HostList *list)
198 {
199 long i;
200
201 for (i = 0; i < list->num; i++)
202 {
203 HostEntry *entry = list->hosts + i;
204 if (mDNSSameAddress(addr, &entry->addr))
205 return entry;
206 }
207
208 return NULL;
209 }
210
AddHost(const mDNSAddr * addr,HostList * list)211 mDNSlocal HostEntry *AddHost(const mDNSAddr *addr, HostList *list)
212 {
213 int i;
214 HostEntry *entry;
215 if (list->num >= list->max)
216 {
217 long newMax = list->max + 64;
218 HostEntry *newHosts = realloc(list->hosts, newMax * sizeof(HostEntry));
219 if (newHosts == NULL)
220 return NULL;
221 list->max = newMax;
222 list->hosts = newHosts;
223 }
224
225 entry = list->hosts + list->num++;
226
227 entry->addr = *addr;
228 for (i=0; i<HostPkt_NumTypes; i++) entry->pkts[i] = 0;
229 entry->totalops = 0;
230 for (i=0; i<OP_NumTypes; i++) entry->stat[i] = 0;
231 entry->hostname.c[0] = 0;
232 entry->revname.c[0] = 0;
233 entry->HIHardware.c[0] = 0;
234 entry->HISoftware.c[0] = 0;
235 entry->NumQueries = 0;
236
237 if (entry->addr.type == mDNSAddrType_IPv4)
238 {
239 mDNSv4Addr ip = entry->addr.ip.v4;
240 char buffer[32];
241 // Note: This is reverse order compared to a normal dotted-decimal IP address, so we can't use our customary "%.4a" format code
242 mDNS_snprintf(buffer, sizeof(buffer), "%d.%d.%d.%d.in-addr.arpa.", ip.b[3], ip.b[2], ip.b[1], ip.b[0]);
243 MakeDomainNameFromDNSNameString(&entry->revname, buffer);
244 }
245
246 return(entry);
247 }
248
GotPacketFromHost(const mDNSAddr * addr,HostPkt_Type t,mDNSOpaque16 id)249 mDNSlocal HostEntry *GotPacketFromHost(const mDNSAddr *addr, HostPkt_Type t, mDNSOpaque16 id)
250 {
251 if (ExactlyOneFilter) return(NULL);
252 else
253 {
254 HostList *list = (addr->type == mDNSAddrType_IPv4) ? &IPv4HostList : &IPv6HostList;
255 HostEntry *entry = FindHost(addr, list);
256 if (!entry) entry = AddHost(addr, list);
257 if (!entry) return(NULL);
258 // Don't count our own interrogation packets
259 if (id.NotAnInteger != 0xFFFF) entry->pkts[t]++;
260 return(entry);
261 }
262 }
263
RecordHostInfo(HostEntry * entry,const ResourceRecord * const pktrr)264 mDNSlocal void RecordHostInfo(HostEntry *entry, const ResourceRecord *const pktrr)
265 {
266 if (!entry->hostname.c[0])
267 {
268 if (pktrr->rrtype == kDNSType_A || pktrr->rrtype == kDNSType_AAAA)
269 {
270 // Should really check that the rdata in the address record matches the source address of this packet
271 entry->NumQueries = 0;
272 AssignDomainName(&entry->hostname, pktrr->name);
273 }
274
275 if (pktrr->rrtype == kDNSType_PTR)
276 if (SameDomainName(&entry->revname, pktrr->name))
277 {
278 entry->NumQueries = 0;
279 AssignDomainName(&entry->hostname, &pktrr->rdata->u.name);
280 }
281 }
282 else if (pktrr->rrtype == kDNSType_HINFO)
283 {
284 RDataBody *rd = &pktrr->rdata->u;
285 mDNSu8 *rdend = (mDNSu8 *)rd + pktrr->rdlength;
286 mDNSu8 *hw = rd->txt.c;
287 mDNSu8 *sw = hw + 1 + (mDNSu32)hw[0];
288 if (sw + 1 + sw[0] <= rdend)
289 {
290 AssignDomainName(&entry->hostname, pktrr->name);
291 mDNSPlatformMemCopy(entry->HIHardware.c, hw, 1 + (mDNSu32)hw[0]);
292 mDNSPlatformMemCopy(entry->HISoftware.c, sw, 1 + (mDNSu32)sw[0]);
293 }
294 }
295 }
296
SendUnicastQuery(mDNS * const m,HostEntry * entry,domainname * name,mDNSu16 rrtype,mDNSInterfaceID InterfaceID)297 mDNSlocal void SendUnicastQuery(mDNS *const m, HostEntry *entry, domainname *name, mDNSu16 rrtype, mDNSInterfaceID InterfaceID)
298 {
299 const mDNSOpaque16 id = { { 0xFF, 0xFF } };
300 DNSMessage query;
301 mDNSu8 *qptr = query.data;
302 const mDNSu8 *const limit = query.data + sizeof(query.data);
303 const mDNSAddr *target = &entry->addr;
304 InitializeDNSMessage(&query.h, id, QueryFlags);
305 qptr = putQuestion(&query, qptr, limit, name, rrtype, kDNSClass_IN);
306 entry->LastQuery = m->timenow;
307 entry->NumQueries++;
308
309 // Note: When there are multiple mDNSResponder agents running on a single machine
310 // (e.g. Apple mDNSResponder plus a SliMP3 server with embedded mDNSResponder)
311 // it is possible that unicast queries may not go to the primary system responder.
312 // We try the first query using unicast, but if that doesn't work we try again via multicast.
313 if (entry->NumQueries > 2)
314 {
315 target = &AllDNSLinkGroup_v4;
316 }
317 else
318 {
319 //mprintf("%#a Q\n", target);
320 InterfaceID = mDNSInterface_Any; // Send query from our unicast reply socket
321 }
322
323 mDNSSendDNSMessage(&mDNSStorage, &query, qptr, InterfaceID, mDNSNULL, target, MulticastDNSPort, mDNSNULL, mDNSNULL);
324 }
325
AnalyseHost(mDNS * const m,HostEntry * entry,const mDNSInterfaceID InterfaceID)326 mDNSlocal void AnalyseHost(mDNS *const m, HostEntry *entry, const mDNSInterfaceID InterfaceID)
327 {
328 // If we've done four queries without answer, give up
329 if (entry->NumQueries >= 4) return;
330
331 // If we've done a query in the last second, give the host a chance to reply before trying again
332 if (entry->NumQueries && m->timenow - entry->LastQuery < mDNSPlatformOneSecond) return;
333
334 // If we don't know the host name, try to find that first
335 if (!entry->hostname.c[0])
336 {
337 if (entry->revname.c[0])
338 {
339 SendUnicastQuery(m, entry, &entry->revname, kDNSType_PTR, InterfaceID);
340 //mprintf("%##s PTR %d\n", entry->revname.c, entry->NumQueries);
341 }
342 }
343 // If we have the host name but no HINFO, now ask for that
344 else if (!entry->HIHardware.c[0])
345 {
346 SendUnicastQuery(m, entry, &entry->hostname, kDNSType_HINFO, InterfaceID);
347 //mprintf("%##s HINFO %d\n", entry->hostname.c, entry->NumQueries);
348 }
349 }
350
CompareHosts(const void * p1,const void * p2)351 mDNSlocal int CompareHosts(const void *p1, const void *p2)
352 {
353 return (int)(HostEntryTotalPackets((HostEntry *)p2) - HostEntryTotalPackets((HostEntry *)p1));
354 }
355
ShowSortedHostList(HostList * list,int max)356 mDNSlocal void ShowSortedHostList(HostList *list, int max)
357 {
358 HostEntry *e, *end = &list->hosts[(max < list->num) ? max : list->num];
359 qsort(list->hosts, list->num, sizeof(HostEntry), CompareHosts);
360 if (list->num) mprintf("\n%-25s%s%s\n", "Source Address", OPBanner, " Pkts Query LegacyQ Response");
361 for (e = &list->hosts[0]; e < end; e++)
362 {
363 int len = mprintf("%#-25a", &e->addr);
364 if (len > 25) mprintf("\n%25s", "");
365 mprintf("%8lu %8lu %8lu %8lu %8lu %8lu %8lu", e->totalops,
366 e->stat[OP_probe], e->stat[OP_goodbye],
367 e->stat[OP_browseq], e->stat[OP_browsea],
368 e->stat[OP_resolveq], e->stat[OP_resolvea]);
369 mprintf(" %8lu %8lu %8lu %8lu",
370 HostEntryTotalPackets(e), e->pkts[HostPkt_Q], e->pkts[HostPkt_L], e->pkts[HostPkt_R]);
371 if (e->pkts[HostPkt_B]) mprintf("Bad: %8lu", e->pkts[HostPkt_B]);
372 mprintf("\n");
373 if (!e->HISoftware.c[0] && e->NumQueries > 2)
374 mDNSPlatformMemCopy(&e->HISoftware, "\x27*** Unknown (Jaguar, Windows, etc.) ***", 0x28);
375 if (e->hostname.c[0] || e->HIHardware.c[0] || e->HISoftware.c[0])
376 mprintf("%##-45s %#-14s %#s\n", e->hostname.c, e->HIHardware.c, e->HISoftware.c);
377 }
378 }
379
380 //*************************************************************************************************************
381 // Receive and process packets
382
ExtractServiceType(const domainname * const fqdn,domainname * const srvtype)383 mDNSexport mDNSBool ExtractServiceType(const domainname *const fqdn, domainname *const srvtype)
384 {
385 int i, len;
386 const mDNSu8 *src = fqdn->c;
387 mDNSu8 *dst = srvtype->c;
388
389 len = *src;
390 if (len == 0 || len >= 0x40) return(mDNSfalse);
391 if (src[1] != '_') src += 1 + len;
392
393 len = *src;
394 if (len == 0 || len >= 0x40 || src[1] != '_') return(mDNSfalse);
395 for (i=0; i<=len; i++) *dst++ = *src++;
396
397 len = *src;
398 if (len == 0 || len >= 0x40 || src[1] != '_') return(mDNSfalse);
399 for (i=0; i<=len; i++) *dst++ = *src++;
400
401 *dst++ = 0; // Put the null root label on the end of the service type
402
403 return(mDNStrue);
404 }
405
recordstat(HostEntry * entry,const domainname * fqdn,int op,mDNSu16 rrtype)406 mDNSlocal void recordstat(HostEntry *entry, const domainname *fqdn, int op, mDNSu16 rrtype)
407 {
408 ActivityStat **s = &stats;
409 domainname srvtype;
410
411 if (op != OP_probe)
412 {
413 if (rrtype == kDNSType_SRV || rrtype == kDNSType_TXT) op = op - OP_browsegroup + OP_resolvegroup;
414 else if (rrtype != kDNSType_PTR) return;
415 }
416
417 if (!ExtractServiceType(fqdn, &srvtype)) return;
418
419 while (*s && !SameDomainName(&(*s)->srvtype, &srvtype)) s = &(*s)->next;
420 if (!*s)
421 {
422 int i;
423 *s = malloc(sizeof(ActivityStat));
424 if (!*s) exit(-1);
425 (*s)->next = NULL;
426 (*s)->srvtype = srvtype;
427 (*s)->printed = 0;
428 (*s)->totalops = 0;
429 for (i=0; i<OP_NumTypes; i++) (*s)->stat[i] = 0;
430 }
431
432 (*s)->totalops++;
433 (*s)->stat[op]++;
434 if (entry)
435 {
436 entry->totalops++;
437 entry->stat[op]++;
438 }
439 }
440
printstats(int max)441 mDNSlocal void printstats(int max)
442 {
443 int i;
444 if (!stats) return;
445 for (i=0; i<max; i++)
446 {
447 int max = 0;
448 ActivityStat *s, *m = NULL;
449 for (s = stats; s; s=s->next)
450 if (!s->printed && max < s->totalops)
451 { m = s; max = s->totalops; }
452 if (!m) return;
453 m->printed = mDNStrue;
454 if (i==0) mprintf("%-25s%s\n", "Service Type", OPBanner);
455 mprintf("%##-25s%8d %8d %8d %8d %8d %8d %8d\n", m->srvtype.c, m->totalops, m->stat[OP_probe],
456 m->stat[OP_goodbye], m->stat[OP_browseq], m->stat[OP_browsea], m->stat[OP_resolveq], m->stat[OP_resolvea]);
457 }
458 }
459
FindUpdate(mDNS * const m,const DNSMessage * const query,const mDNSu8 * ptr,const mDNSu8 * const end,DNSQuestion * q,LargeCacheRecord * pkt)460 mDNSlocal const mDNSu8 *FindUpdate(mDNS *const m, const DNSMessage *const query, const mDNSu8 *ptr, const mDNSu8 *const end,
461 DNSQuestion *q, LargeCacheRecord *pkt)
462 {
463 int i;
464 for (i = 0; i < query->h.numAuthorities; i++)
465 {
466 const mDNSu8 *p2 = ptr;
467 ptr = GetLargeResourceRecord(m, query, ptr, end, q->InterfaceID, kDNSRecordTypePacketAuth, pkt);
468 if (!ptr) break;
469 if (m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative && ResourceRecordAnswersQuestion(&pkt->r.resrec, q)) return(p2);
470 }
471 return(mDNSNULL);
472 }
473
DisplayPacketHeader(mDNS * const m,const DNSMessage * const msg,const mDNSu8 * const end,const mDNSAddr * srcaddr,mDNSIPPort srcport,const mDNSAddr * dstaddr,const mDNSInterfaceID InterfaceID)474 mDNSlocal void DisplayPacketHeader(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *srcaddr, mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSInterfaceID InterfaceID)
475 {
476 const char *const ptype = (msg->h.flags.b[0] & kDNSFlag0_QR_Response) ? "-R- " :
477 (srcport.NotAnInteger == MulticastDNSPort.NotAnInteger) ? "-Q- " : "-LQ-";
478
479 struct timeval tv;
480 struct tm tm;
481 const mDNSu32 index = mDNSPlatformInterfaceIndexfromInterfaceID(m, InterfaceID, mDNSfalse);
482 char if_name[IFNAMSIZ]; // Older Linux distributions don't define IF_NAMESIZE
483 if_indextoname(index, if_name);
484 gettimeofday(&tv, NULL);
485 localtime_r((time_t*)&tv.tv_sec, &tm);
486 mprintf("\n%d:%02d:%02d.%06d Interface %d/%s\n", tm.tm_hour, tm.tm_min, tm.tm_sec, tv.tv_usec, index, if_name);
487
488 mprintf("%#-16a %s Q:%3d Ans:%3d Auth:%3d Add:%3d Size:%5d bytes",
489 srcaddr, ptype, msg->h.numQuestions, msg->h.numAnswers, msg->h.numAuthorities, msg->h.numAdditionals, end - (mDNSu8 *)msg);
490
491 if (msg->h.id.NotAnInteger) mprintf(" ID:%u", mDNSVal16(msg->h.id));
492
493 if (!mDNSAddrIsDNSMulticast(dstaddr)) mprintf(" To: %#a", dstaddr);
494
495 if (msg->h.flags.b[0] & kDNSFlag0_TC)
496 {
497 if (msg->h.flags.b[0] & kDNSFlag0_QR_Response) mprintf(" Truncated");
498 else mprintf(" Truncated (KA list continues in next packet)");
499 }
500 mprintf("\n");
501 }
502
DisplayResourceRecord(const mDNSAddr * const srcaddr,const char * const op,const ResourceRecord * const pktrr)503 mDNSlocal void DisplayResourceRecord(const mDNSAddr *const srcaddr, const char *const op, const ResourceRecord *const pktrr)
504 {
505 static const char hexchars[16] = "0123456789ABCDEF";
506 #define MaxWidth 132
507 char buffer[MaxWidth+8];
508 char *p = buffer;
509
510 RDataBody *rd = &pktrr->rdata->u;
511 mDNSu8 *rdend = (mDNSu8 *)rd + pktrr->rdlength;
512 int n = mprintf("%#-16a %-5s %-5s%5lu %##s -> ", srcaddr, op, DNSTypeName(pktrr->rrtype), pktrr->rroriginalttl, pktrr->name->c);
513
514 if (pktrr->RecordType == kDNSRecordTypePacketNegative) { mprintf("**** ERROR: FAILED TO READ RDATA ****\n"); return; }
515
516 // The kDNSType_OPT case below just calls GetRRDisplayString_rdb
517 // Perhaps more (or all?) of the cases should do that?
518 switch(pktrr->rrtype)
519 {
520 case kDNSType_A: n += mprintf("%.4a", &rd->ipv4); break;
521 case kDNSType_PTR: n += mprintf("%##.*s", MaxWidth - n, rd->name.c); break;
522 case kDNSType_HINFO:// same as kDNSType_TXT below
523 case kDNSType_TXT: {
524 mDNSu8 *t = rd->txt.c;
525 while (t < rdend && t[0] && p < buffer+MaxWidth)
526 {
527 int i;
528 for (i=1; i<=t[0] && p < buffer+MaxWidth; i++)
529 {
530 if (t[i] == '\\') *p++ = '\\';
531 if (t[i] >= ' ') *p++ = t[i];
532 else
533 {
534 *p++ = '\\';
535 *p++ = '0';
536 *p++ = 'x';
537 *p++ = hexchars[t[i] >> 4];
538 *p++ = hexchars[t[i] & 0xF];
539 }
540 }
541 t += 1+t[0];
542 if (t < rdend && t[0]) { *p++ = '\\'; *p++ = ' '; }
543 }
544 *p++ = 0;
545 n += mprintf("%.*s", MaxWidth - n, buffer);
546 } break;
547 case kDNSType_AAAA: n += mprintf("%.16a", &rd->ipv6); break;
548 case kDNSType_SRV: n += mprintf("%##s:%d", rd->srv.target.c, mDNSVal16(rd->srv.port)); break;
549 case kDNSType_OPT: {
550 char b[MaxMsg];
551 // Quick hack: we don't want the prefix that GetRRDisplayString_rdb puts at the start of its
552 // string, because it duplicates the name and rrtype we already display, so we compute the
553 // length of that prefix and strip that many bytes off the beginning of the string we display.
554 mDNSu32 striplen = mDNS_snprintf(b, MaxMsg-1, "%4d %##s %s ", pktrr->rdlength, pktrr->name->c, DNSTypeName(pktrr->rrtype));
555 GetRRDisplayString_rdb(pktrr, &pktrr->rdata->u, b);
556 n += mprintf("%.*s", MaxWidth - n, b + striplen);
557 } break;
558 case kDNSType_NSEC: {
559 int i;
560 for (i=0; i<255; i++)
561 if (rd->nsec.bitmap[i>>3] & (128 >> (i&7)))
562 n += mprintf("%s ", DNSTypeName(i));
563 } break;
564 default: {
565 mDNSu8 *s = rd->data;
566 while (s < rdend && p < buffer+MaxWidth)
567 {
568 if (*s == '\\') *p++ = '\\';
569 if (*s >= ' ') *p++ = *s;
570 else
571 {
572 *p++ = '\\';
573 *p++ = '0';
574 *p++ = 'x';
575 *p++ = hexchars[*s >> 4];
576 *p++ = hexchars[*s & 0xF];
577 }
578 s++;
579 }
580 *p++ = 0;
581 n += mprintf("%.*s", MaxWidth - n, buffer);
582 } break;
583 }
584
585 mprintf("\n");
586 }
587
HexDump(const mDNSu8 * ptr,const mDNSu8 * const end)588 mDNSlocal void HexDump(const mDNSu8 *ptr, const mDNSu8 *const end)
589 {
590 while (ptr < end)
591 {
592 int i;
593 for (i=0; i<16; i++)
594 if (&ptr[i] < end) mprintf("%02X ", ptr[i]);
595 else mprintf(" ");
596 for (i=0; i<16; i++)
597 if (&ptr[i] < end) mprintf("%c", ptr[i] <= ' ' || ptr[i] >= 126 ? '.' : ptr[i]);
598 ptr += 16;
599 mprintf("\n");
600 }
601 }
602
DisplayError(const mDNSAddr * srcaddr,const mDNSu8 * ptr,const mDNSu8 * const end,char * msg)603 mDNSlocal void DisplayError(const mDNSAddr *srcaddr, const mDNSu8 *ptr, const mDNSu8 *const end, char *msg)
604 {
605 mprintf("%#-16a **** ERROR: FAILED TO READ %s **** \n", srcaddr, msg);
606 HexDump(ptr, end);
607 }
608
DisplayQuery(mDNS * const m,const DNSMessage * const msg,const mDNSu8 * const end,const mDNSAddr * srcaddr,mDNSIPPort srcport,const mDNSAddr * dstaddr,const mDNSInterfaceID InterfaceID)609 mDNSlocal void DisplayQuery(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end,
610 const mDNSAddr *srcaddr, mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSInterfaceID InterfaceID)
611 {
612 int i;
613 const mDNSu8 *ptr = msg->data;
614 const mDNSu8 *auth = LocateAuthorities(msg, end);
615 mDNSBool MQ = (srcport.NotAnInteger == MulticastDNSPort.NotAnInteger);
616 HostEntry *entry = GotPacketFromHost(srcaddr, MQ ? HostPkt_Q : HostPkt_L, msg->h.id);
617 LargeCacheRecord pkt;
618
619 DisplayPacketHeader(m, msg, end, srcaddr, srcport, dstaddr, InterfaceID);
620 if (msg->h.id.NotAnInteger != 0xFFFF)
621 {
622 if (MQ) NumPktQ++; else NumPktL++;
623 }
624
625 for (i=0; i<msg->h.numQuestions; i++)
626 {
627 DNSQuestion q;
628 mDNSu8 *p2 = (mDNSu8 *)getQuestion(msg, ptr, end, InterfaceID, &q);
629 mDNSu16 ucbit = q.qclass & kDNSQClass_UnicastResponse;
630 q.qclass &= ~kDNSQClass_UnicastResponse;
631 if (!p2) { DisplayError(srcaddr, ptr, end, "QUESTION"); return; }
632 ptr = p2;
633 p2 = (mDNSu8 *)FindUpdate(m, msg, auth, end, &q, &pkt);
634 if (p2)
635 {
636 NumProbes++;
637 DisplayResourceRecord(srcaddr, ucbit ? "(PU)" : "(PM)", &pkt.r.resrec);
638 recordstat(entry, &q.qname, OP_probe, q.qtype);
639 p2 = (mDNSu8 *)skipDomainName(msg, p2, end);
640 // Having displayed this update record, clear type and class so we don't display the same one again.
641 p2[0] = p2[1] = p2[2] = p2[3] = 0;
642 }
643 else
644 {
645 const char *ptype = ucbit ? "(QU)" : "(QM)";
646 if (srcport.NotAnInteger == MulticastDNSPort.NotAnInteger) NumQuestions++;
647 else { NumLegacy++; ptype = "(LQ)"; }
648 mprintf("%#-16a %-5s %-5s %##s\n", srcaddr, ptype, DNSTypeName(q.qtype), q.qname.c);
649 if (msg->h.id.NotAnInteger != 0xFFFF) recordstat(entry, &q.qname, OP_query, q.qtype);
650 }
651 }
652
653 for (i=0; i<msg->h.numAnswers; i++)
654 {
655 const mDNSu8 *ep = ptr;
656 ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAns, &pkt);
657 if (!ptr) { DisplayError(srcaddr, ep, end, "KNOWN ANSWER"); return; }
658 DisplayResourceRecord(srcaddr, "(KA)", &pkt.r.resrec);
659
660 // In the case of queries with long multi-packet KA lists, we count each subsequent KA packet
661 // the same as a single query, to more accurately reflect the burden on the network
662 // (A query with a six-packet KA list is *at least* six times the burden on the network as a single-packet query.)
663 if (msg->h.numQuestions == 0 && i == 0)
664 recordstat(entry, pkt.r.resrec.name, OP_query, pkt.r.resrec.rrtype);
665 }
666
667 for (i=0; i<msg->h.numAuthorities; i++)
668 {
669 const mDNSu8 *ep = ptr;
670 ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAuth, &pkt);
671 if (!ptr) { DisplayError(srcaddr, ep, end, "AUTHORITY"); return; }
672 // After we display an Update record with its matching question (above) we zero out its type and class
673 // If any remain that haven't been zero'd out, display them here
674 if (pkt.r.resrec.rrtype || pkt.r.resrec.rrclass) DisplayResourceRecord(srcaddr, "(AU)", &pkt.r.resrec);
675 }
676
677 for (i=0; i<msg->h.numAdditionals; i++)
678 {
679 const mDNSu8 *ep = ptr;
680 ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAdd, &pkt);
681 if (!ptr) { DisplayError(srcaddr, ep, end, "ADDITIONAL"); return; }
682 DisplayResourceRecord(srcaddr, pkt.r.resrec.rrtype == kDNSType_OPT ? "(OP)" : "(AD)", &pkt.r.resrec);
683 }
684
685 if (entry) AnalyseHost(m, entry, InterfaceID);
686 }
687
DisplayResponse(mDNS * const m,const DNSMessage * const msg,const mDNSu8 * end,const mDNSAddr * srcaddr,mDNSIPPort srcport,const mDNSAddr * dstaddr,const mDNSInterfaceID InterfaceID)688 mDNSlocal void DisplayResponse(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *end,
689 const mDNSAddr *srcaddr, mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSInterfaceID InterfaceID)
690 {
691 int i;
692 const mDNSu8 *ptr = msg->data;
693 HostEntry *entry = GotPacketFromHost(srcaddr, HostPkt_R, msg->h.id);
694 LargeCacheRecord pkt;
695
696 DisplayPacketHeader(m, msg, end, srcaddr, srcport, dstaddr, InterfaceID);
697 if (msg->h.id.NotAnInteger != 0xFFFF) NumPktR++;
698
699 for (i=0; i<msg->h.numQuestions; i++)
700 {
701 DNSQuestion q;
702 const mDNSu8 *ep = ptr;
703 ptr = getQuestion(msg, ptr, end, InterfaceID, &q);
704 if (!ptr) { DisplayError(srcaddr, ep, end, "QUESTION"); return; }
705 if (mDNSAddrIsDNSMulticast(dstaddr))
706 mprintf("%#-16a (?) **** ERROR: SHOULD NOT HAVE Q IN mDNS RESPONSE **** %-5s %##s\n", srcaddr, DNSTypeName(q.qtype), q.qname.c);
707 else
708 mprintf("%#-16a (Q) %-5s %##s\n", srcaddr, DNSTypeName(q.qtype), q.qname.c);
709 }
710
711 for (i=0; i<msg->h.numAnswers; i++)
712 {
713 const mDNSu8 *ep = ptr;
714 ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAns, &pkt);
715 if (!ptr) { DisplayError(srcaddr, ep, end, "ANSWER"); return; }
716 if (pkt.r.resrec.rroriginalttl)
717 {
718 NumAnswers++;
719 DisplayResourceRecord(srcaddr, (pkt.r.resrec.RecordType & kDNSRecordTypePacketUniqueMask) ? "(AN)" : "(AN+)", &pkt.r.resrec);
720 if (msg->h.id.NotAnInteger != 0xFFFF) recordstat(entry, pkt.r.resrec.name, OP_answer, pkt.r.resrec.rrtype);
721 if (entry) RecordHostInfo(entry, &pkt.r.resrec);
722 }
723 else
724 {
725 NumGoodbyes++;
726 DisplayResourceRecord(srcaddr, "(DE)", &pkt.r.resrec);
727 recordstat(entry, pkt.r.resrec.name, OP_goodbye, pkt.r.resrec.rrtype);
728 }
729 }
730
731 for (i=0; i<msg->h.numAuthorities; i++)
732 {
733 const mDNSu8 *ep = ptr;
734 ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAuth, &pkt);
735 if (!ptr) { DisplayError(srcaddr, ep, end, "AUTHORITY"); return; }
736 mprintf("%#-16a (?) **** ERROR: SHOULD NOT HAVE AUTHORITY IN mDNS RESPONSE **** %-5s %##s\n",
737 srcaddr, DNSTypeName(pkt.r.resrec.rrtype), pkt.r.resrec.name->c);
738 }
739
740 for (i=0; i<msg->h.numAdditionals; i++)
741 {
742 const mDNSu8 *ep = ptr;
743 ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAdd, &pkt);
744 if (!ptr) { DisplayError(srcaddr, ep, end, "ADDITIONAL"); return; }
745 NumAdditionals++;
746 DisplayResourceRecord(srcaddr,
747 pkt.r.resrec.rrtype == kDNSType_OPT ? "(OP)" : (pkt.r.resrec.RecordType & kDNSRecordTypePacketUniqueMask) ? "(AD)" : "(AD+)",
748 &pkt.r.resrec);
749 if (entry) RecordHostInfo(entry, &pkt.r.resrec);
750 }
751
752 if (entry) AnalyseHost(m, entry, InterfaceID);
753 }
754
ProcessUnicastResponse(mDNS * const m,const DNSMessage * const msg,const mDNSu8 * end,const mDNSAddr * srcaddr,const mDNSInterfaceID InterfaceID)755 mDNSlocal void ProcessUnicastResponse(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *end, const mDNSAddr *srcaddr, const mDNSInterfaceID InterfaceID)
756 {
757 int i;
758 const mDNSu8 *ptr = LocateAnswers(msg, end);
759 HostEntry *entry = GotPacketFromHost(srcaddr, HostPkt_R, msg->h.id);
760 //mprintf("%#a R\n", srcaddr);
761
762 for (i=0; i<msg->h.numAnswers + msg->h.numAuthorities + msg->h.numAdditionals; i++)
763 {
764 LargeCacheRecord pkt;
765 ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAns, &pkt);
766 if (ptr && pkt.r.resrec.rroriginalttl && entry) RecordHostInfo(entry, &pkt.r.resrec);
767 }
768 }
769
AddressMatchesFilterList(const mDNSAddr * srcaddr)770 mDNSlocal mDNSBool AddressMatchesFilterList(const mDNSAddr *srcaddr)
771 {
772 FilterList *f;
773 if (!Filters) return(srcaddr->type == mDNSAddrType_IPv4);
774 for (f=Filters; f; f=f->next) if (mDNSSameAddress(srcaddr, &f->FilterAddr)) return(mDNStrue);
775 return(mDNSfalse);
776 }
777
mDNSCoreReceive(mDNS * const m,DNSMessage * const msg,const mDNSu8 * const end,const mDNSAddr * srcaddr,mDNSIPPort srcport,const mDNSAddr * dstaddr,mDNSIPPort dstport,const mDNSInterfaceID InterfaceID)778 mDNSexport void mDNSCoreReceive(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end,
779 const mDNSAddr *srcaddr, mDNSIPPort srcport, const mDNSAddr *dstaddr, mDNSIPPort dstport, const mDNSInterfaceID InterfaceID)
780 {
781 const mDNSu8 StdQ = kDNSFlag0_QR_Query | kDNSFlag0_OP_StdQuery;
782 const mDNSu8 StdR = kDNSFlag0_QR_Response | kDNSFlag0_OP_StdQuery;
783 const mDNSu8 QR_OP = (mDNSu8)(msg->h.flags.b[0] & kDNSFlag0_QROP_Mask);
784 mDNSu8 *ptr = (mDNSu8 *)&msg->h.numQuestions;
785 int goodinterface = (FilterInterface == 0);
786
787 (void)dstaddr; // Unused
788 (void)dstport; // Unused
789
790 // Read the integer parts which are in IETF byte-order (MSB first, LSB second)
791 msg->h.numQuestions = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]);
792 msg->h.numAnswers = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]);
793 msg->h.numAuthorities = (mDNSu16)((mDNSu16)ptr[4] << 8 | ptr[5]);
794 msg->h.numAdditionals = (mDNSu16)((mDNSu16)ptr[6] << 8 | ptr[7]);
795
796 // For now we're only interested in monitoring IPv4 traffic.
797 // All IPv6 packets should just be duplicates of the v4 packets.
798 if (!goodinterface) goodinterface = (FilterInterface == (int)mDNSPlatformInterfaceIndexfromInterfaceID(m, InterfaceID, mDNSfalse));
799 if (goodinterface && AddressMatchesFilterList(srcaddr))
800 {
801 mDNS_Lock(m);
802 if (!mDNSAddrIsDNSMulticast(dstaddr))
803 {
804 if (QR_OP == StdQ) mprintf("Unicast query from %#a\n", srcaddr);
805 else if (QR_OP == StdR) ProcessUnicastResponse(m, msg, end, srcaddr, InterfaceID);
806 }
807 else
808 {
809 if (QR_OP == StdQ) DisplayQuery (m, msg, end, srcaddr, srcport, dstaddr, InterfaceID);
810 else if (QR_OP == StdR) DisplayResponse (m, msg, end, srcaddr, srcport, dstaddr, InterfaceID);
811 else
812 {
813 debugf("Unknown DNS packet type %02X%02X (ignored)", msg->h.flags.b[0], msg->h.flags.b[1]);
814 GotPacketFromHost(srcaddr, HostPkt_B, msg->h.id);
815 NumPktB++;
816 }
817 }
818 mDNS_Unlock(m);
819 }
820 }
821
mDNSNetMonitor(void)822 mDNSlocal mStatus mDNSNetMonitor(void)
823 {
824 struct tm tm;
825 int h, m, s, mul, div, TotPkt;
826 #if !defined(WIN32)
827 sigset_t signals;
828 #endif
829
830 mStatus status = mDNS_Init(&mDNSStorage, &PlatformStorage,
831 mDNS_Init_NoCache, mDNS_Init_ZeroCacheSize,
832 mDNS_Init_DontAdvertiseLocalAddresses,
833 mDNS_Init_NoInitCallback, mDNS_Init_NoInitCallbackContext);
834 if (status) return(status);
835
836 gettimeofday(&tv_start, NULL);
837
838 #if defined( WIN32 )
839 status = SetupInterfaceList(&mDNSStorage);
840 if (status) return(status);
841 gStopEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
842 if (gStopEvent == INVALID_HANDLE_VALUE) return mStatus_UnknownErr;
843 if (!SetConsoleCtrlHandler(ConsoleControlHandler, TRUE)) return mStatus_UnknownErr;
844 while (WaitForSingleObjectEx(gStopEvent, INFINITE, TRUE) == WAIT_IO_COMPLETION)
845 DispatchSocketEvents(&mDNSStorage);
846 if (!SetConsoleCtrlHandler(ConsoleControlHandler, FALSE)) return mStatus_UnknownErr;
847 CloseHandle(gStopEvent);
848 #else
849 mDNSPosixListenForSignalInEventLoop(SIGINT);
850 mDNSPosixListenForSignalInEventLoop(SIGTERM);
851
852 do
853 {
854 struct timeval timeout = { 0x3FFFFFFF, 0 }; // wait until SIGINT or SIGTERM
855 mDNSBool gotSomething;
856 mDNSPosixRunEventLoopOnce(&mDNSStorage, &timeout, &signals, &gotSomething);
857 }
858 while ( !( sigismember( &signals, SIGINT) || sigismember( &signals, SIGTERM)));
859 #endif
860
861 // Now display final summary
862 TotPkt = NumPktQ + NumPktL + NumPktR;
863 gettimeofday(&tv_end, NULL);
864 tv_interval = tv_end;
865 if (tv_start.tv_usec > tv_interval.tv_usec)
866 { tv_interval.tv_usec += 1000000; tv_interval.tv_sec--; }
867 tv_interval.tv_sec -= tv_start.tv_sec;
868 tv_interval.tv_usec -= tv_start.tv_usec;
869 h = (tv_interval.tv_sec / 3600);
870 m = (tv_interval.tv_sec % 3600) / 60;
871 s = (tv_interval.tv_sec % 60);
872 if (tv_interval.tv_sec > 10)
873 {
874 mul = 60;
875 div = tv_interval.tv_sec;
876 }
877 else
878 {
879 mul = 60000;
880 div = tv_interval.tv_sec * 1000 + tv_interval.tv_usec / 1000;
881 if (div == 0) div=1;
882 }
883
884 mprintf("\n\n");
885 localtime_r((time_t*)&tv_start.tv_sec, &tm);
886 mprintf("Started %3d:%02d:%02d.%06d\n", tm.tm_hour, tm.tm_min, tm.tm_sec, tv_start.tv_usec);
887 localtime_r((time_t*)&tv_end.tv_sec, &tm);
888 mprintf("End %3d:%02d:%02d.%06d\n", tm.tm_hour, tm.tm_min, tm.tm_sec, tv_end.tv_usec);
889 mprintf("Captured for %3d:%02d:%02d.%06d\n", h, m, s, tv_interval.tv_usec);
890 if (!Filters)
891 {
892 mprintf("Unique source addresses seen on network:");
893 if (IPv4HostList.num) mprintf(" %ld (IPv4)", IPv4HostList.num);
894 if (IPv6HostList.num) mprintf(" %ld (IPv6)", IPv6HostList.num);
895 if (!IPv4HostList.num && !IPv6HostList.num) mprintf(" None");
896 mprintf("\n");
897 }
898 mprintf("\n");
899 mprintf("Modern Query Packets: %7d (avg%5d/min)\n", NumPktQ, NumPktQ * mul / div);
900 mprintf("Legacy Query Packets: %7d (avg%5d/min)\n", NumPktL, NumPktL * mul / div);
901 mprintf("Multicast Response Packets: %7d (avg%5d/min)\n", NumPktR, NumPktR * mul / div);
902 mprintf("Total Multicast Packets: %7d (avg%5d/min)\n", TotPkt, TotPkt * mul / div);
903 mprintf("\n");
904 mprintf("Total New Service Probes: %7d (avg%5d/min)\n", NumProbes, NumProbes * mul / div);
905 mprintf("Total Goodbye Announcements: %7d (avg%5d/min)\n", NumGoodbyes, NumGoodbyes * mul / div);
906 mprintf("Total Query Questions: %7d (avg%5d/min)\n", NumQuestions, NumQuestions * mul / div);
907 mprintf("Total Queries from Legacy Clients:%7d (avg%5d/min)\n", NumLegacy, NumLegacy * mul / div);
908 mprintf("Total Answers/Announcements: %7d (avg%5d/min)\n", NumAnswers, NumAnswers * mul / div);
909 mprintf("Total Additional Records: %7d (avg%5d/min)\n", NumAdditionals, NumAdditionals * mul / div);
910 mprintf("\n");
911 printstats(kReportTopServices);
912
913 if (!ExactlyOneFilter)
914 {
915 ShowSortedHostList(&IPv4HostList, kReportTopHosts);
916 ShowSortedHostList(&IPv6HostList, kReportTopHosts);
917 }
918
919 mDNS_Close(&mDNSStorage);
920 return(0);
921 }
922
main(int argc,char ** argv)923 mDNSexport int main(int argc, char **argv)
924 {
925 const char *progname = strrchr(argv[0], '/') ? strrchr(argv[0], '/') + 1 : argv[0];
926 int i;
927 mStatus status;
928
929 #if defined(WIN32)
930 HeapSetInformation(NULL, HeapEnableTerminationOnCorruption, NULL, 0);
931 #endif
932
933 setlinebuf(stdout); // Want to see lines as they appear, not block buffered
934
935 for (i=1; i<argc; i++)
936 {
937 if (i+1 < argc && !strcmp(argv[i], "-i") && atoi(argv[i+1]))
938 {
939 FilterInterface = atoi(argv[i+1]);
940 i += 2;
941 printf("Monitoring interface %d\n", FilterInterface);
942 }
943 else
944 {
945 struct in_addr s4;
946 struct in6_addr s6;
947 FilterList *f;
948 mDNSAddr a;
949 a.type = mDNSAddrType_IPv4;
950
951 if (inet_pton(AF_INET, argv[i], &s4) == 1)
952 a.ip.v4.NotAnInteger = s4.s_addr;
953 else if (inet_pton(AF_INET6, argv[i], &s6) == 1)
954 {
955 a.type = mDNSAddrType_IPv6;
956 mDNSPlatformMemCopy(&a.ip.v6, &s6, sizeof(a.ip.v6));
957 }
958 else
959 {
960 struct hostent *h = gethostbyname(argv[i]);
961 if (h) a.ip.v4.NotAnInteger = *(long*)h->h_addr;
962 else goto usage;
963 }
964
965 f = malloc(sizeof(*f));
966 f->FilterAddr = a;
967 f->next = Filters;
968 Filters = f;
969 }
970 }
971
972 status = mDNSNetMonitor();
973 if (status) { fprintf(stderr, "%s: mDNSNetMonitor failed %d\n", progname, (int)status); return(status); }
974 return(0);
975
976 usage:
977 fprintf(stderr, "\nmDNS traffic monitor\n");
978 fprintf(stderr, "Usage: %s [-i index] [host]\n", progname);
979 fprintf(stderr, "Optional [-i index] parameter displays only packets from that interface index\n");
980 fprintf(stderr, "Optional [host] parameter displays only packets from that host\n");
981
982 fprintf(stderr, "\nPer-packet header output:\n");
983 fprintf(stderr, "-Q- Multicast Query from mDNS client that accepts multicast responses\n");
984 fprintf(stderr, "-R- Multicast Response packet containing answers/announcements\n");
985 fprintf(stderr, "-LQ- Multicast Query from legacy client that does *not* listen for multicast responses\n");
986 fprintf(stderr, "Q/Ans/Auth/Add Number of questions, answers, authority records and additional records in packet\n");
987
988 fprintf(stderr, "\nPer-record display:\n");
989 fprintf(stderr, "(PM) Probe Question (new service starting), requesting multicast response\n");
990 fprintf(stderr, "(PU) Probe Question (new service starting), requesting unicast response\n");
991 fprintf(stderr, "(DE) Deletion/Goodbye (service going away)\n");
992 fprintf(stderr, "(LQ) Legacy Query Question\n");
993 fprintf(stderr, "(QM) Query Question, requesting multicast response\n");
994 fprintf(stderr, "(QU) Query Question, requesting unicast response\n");
995 fprintf(stderr, "(KA) Known Answer (information querier already knows)\n");
996 fprintf(stderr, "(AN) Unique Answer to question (or periodic announcment) (entire RR Set)\n");
997 fprintf(stderr, "(AN+) Answer to question (or periodic announcment) (add to existing RR Set members)\n");
998 fprintf(stderr, "(AD) Unique Additional Record Set (entire RR Set)\n");
999 fprintf(stderr, "(AD+) Additional records (add to existing RR Set members)\n");
1000
1001 fprintf(stderr, "\nFinal summary, sorted by service type:\n");
1002 fprintf(stderr, "Probe Probes for this service type starting up\n");
1003 fprintf(stderr, "Goodbye Goodbye (deletion) packets for this service type shutting down\n");
1004 fprintf(stderr, "BrowseQ Browse questions from clients browsing to find a list of instances of this service\n");
1005 fprintf(stderr, "BrowseA Browse answers/announcments advertising instances of this service\n");
1006 fprintf(stderr, "ResolveQ Resolve questions from clients actively connecting to an instance of this service\n");
1007 fprintf(stderr, "ResolveA Resolve answers/announcments giving connection information for an instance of this service\n");
1008 fprintf(stderr, "\n");
1009 return(-1);
1010 }
1011