/* -*- Mode: C; tab-width: 4 -*-
*
* Copyright (c) 2002-2004 Apple Computer, Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
//*************************************************************************************************************
// Incorporate mDNS.c functionality
// We want to use much of the functionality provided by "mDNS.c",
// except we'll steal the packets that would be sent to normal mDNSCoreReceive() routine
#define mDNSCoreReceive __NOT__mDNSCoreReceive__NOT__
#include "../mDNSCore/mDNS.c"
#undef mDNSCoreReceive
//*************************************************************************************************************
// Headers
#include <stdio.h> // For printf()
#include <stdlib.h> // For malloc()
#include <string.h> // For strrchr(), strcmp()
#include <time.h> // For "struct tm" etc.
#include <signal.h> // For SIGINT, SIGTERM
#if defined(WIN32)
// Both mDNS.c and mDNSWin32.h declare UDPSocket_struct type resulting in a compile-time error, so
// trick the compiler when including mDNSWin32.h
# define UDPSocket_struct _UDPSocket_struct
# include <mDNSEmbeddedAPI.h>
# include <mDNSWin32.h>
# include <PosixCompat.h>
# include <Poll.h>
# define IFNAMSIZ 256
static HANDLE gStopEvent = INVALID_HANDLE_VALUE;
static mDNSBool gRunning;
static void CALLBACK StopNotification( HANDLE event, void *context ) { gRunning = mDNSfalse; }
static BOOL WINAPI ConsoleControlHandler( DWORD inControlEvent ) { SetEvent( gStopEvent ); return TRUE; }
void setlinebuf( FILE * fp ) {}
#else
# include <netdb.h> // For gethostbyname()
# include <sys/socket.h> // For AF_INET, AF_INET6, etc.
# include <net/if.h> // For IF_NAMESIZE
# include <netinet/in.h> // For INADDR_NONE
# include <arpa/inet.h> // For inet_addr()
# include "mDNSPosix.h" // Defines the specific types needed to run mDNS on this platform
#endif
#include "ExampleClientApp.h"
//*************************************************************************************************************
// Types and structures
enum
{
// Primitive operations
OP_probe = 0,
OP_goodbye = 1,
// These are meta-categories;
// Query and Answer operations are actually subdivided into two classes:
// Browse query/answer and
// Resolve query/answer
OP_query = 2,
OP_answer = 3,
// The "Browse" variants of query/answer
OP_browsegroup = 2,
OP_browseq = 2,
OP_browsea = 3,
// The "Resolve" variants of query/answer
OP_resolvegroup = 4,
OP_resolveq = 4,
OP_resolvea = 5,
OP_NumTypes = 6
};
typedef struct ActivityStat_struct ActivityStat;
struct ActivityStat_struct
{
ActivityStat *next;
domainname srvtype;
int printed;
int totalops;
int stat[OP_NumTypes];
};
typedef struct FilterList_struct FilterList;
struct FilterList_struct
{
FilterList *next;
mDNSAddr FilterAddr;
};
//*************************************************************************************************************
// Constants
#define kReportTopServices 15
#define kReportTopHosts 15
//*************************************************************************************************************
// Globals
mDNS mDNSStorage; // mDNS core uses this to store its globals
static mDNS_PlatformSupport PlatformStorage; // Stores this platform's globals
mDNSexport const char ProgramName[] = "mDNSNetMonitor";
struct timeval tv_start, tv_end, tv_interval;
static int FilterInterface = 0;
static FilterList *Filters;
#define ExactlyOneFilter (Filters && !Filters->next)
static mDNSBool AddressType = mDNSAddrType_IPv4;
static int NumPktQ, NumPktL, NumPktR, NumPktB; // Query/Legacy/Response/Bad
static int NumProbes, NumGoodbyes, NumQuestions, NumLegacy, NumAnswers, NumAdditionals;
static ActivityStat *stats;
#define OPBanner "Total Ops Probe Goodbye BrowseQ BrowseA ResolveQ ResolveA"
mDNSexport void mDNSCoreReceive(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr, const mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSIPPort dstport, const mDNSInterfaceID InterfaceID);
//*************************************************************************************************************
// Utilities
// Special version of printf that knows how to print IP addresses, DNS-format name strings, etc.
mDNSlocal mDNSu32 mprintf(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2);
mDNSlocal mDNSu32 mprintf(const char *format, ...)
{
mDNSu32 length;
unsigned char buffer[512];
va_list ptr;
va_start(ptr,format);
length = mDNS_vsnprintf((char *)buffer, sizeof(buffer), format, ptr);
va_end(ptr);
printf("%s", buffer);
return(length);
}
//*************************************************************************************************************
// Host Address List
//
// Would benefit from a hash
typedef enum
{
HostPkt_Q = 0, // Query
HostPkt_L = 1, // Legacy Query
HostPkt_R = 2, // Response
HostPkt_B = 3, // Bad
HostPkt_NumTypes = 4
} HostPkt_Type;
typedef struct
{
mDNSAddr addr;
unsigned long pkts[HostPkt_NumTypes];
unsigned long totalops;
unsigned long stat[OP_NumTypes];
domainname hostname;
domainname revname;
UTF8str255 HIHardware;
UTF8str255 HISoftware;
mDNSu32 NumQueries;
mDNSs32 LastQuery;
} HostEntry;
#define HostEntryTotalPackets(H) ((H)->pkts[HostPkt_Q] + (H)->pkts[HostPkt_L] + (H)->pkts[HostPkt_R] + (H)->pkts[HostPkt_B])
typedef struct
{
long num;
long max;
HostEntry *hosts;
} HostList;
static HostList IPv4HostList = { 0, 0, 0 };
static HostList IPv6HostList = { 0, 0, 0 };
mDNSlocal HostEntry *FindHost(const mDNSAddr *addr, HostList *list)
{
long i;
for (i = 0; i < list->num; i++)
{
HostEntry *entry = list->hosts + i;
if (mDNSSameAddress(addr, &entry->addr))
return entry;
}
return NULL;
}
mDNSlocal HostEntry *AddHost(const mDNSAddr *addr, HostList *list)
{
int i;
HostEntry *entry;
if (list->num >= list->max)
{
long newMax = list->max + 64;
HostEntry *newHosts = realloc(list->hosts, newMax * sizeof(HostEntry));
if (newHosts == NULL)
return NULL;
list->max = newMax;
list->hosts = newHosts;
}
entry = list->hosts + list->num++;
entry->addr = *addr;
for (i=0; i<HostPkt_NumTypes; i++) entry->pkts[i] = 0;
entry->totalops = 0;
for (i=0; i<OP_NumTypes; i++) entry->stat[i] = 0;
entry->hostname.c[0] = 0;
entry->revname.c[0] = 0;
entry->HIHardware.c[0] = 0;
entry->HISoftware.c[0] = 0;
entry->NumQueries = 0;
if (entry->addr.type == mDNSAddrType_IPv4)
{
mDNSv4Addr ip = entry->addr.ip.v4;
char buffer[32];
// Note: This is reverse order compared to a normal dotted-decimal IP address, so we can't use our customary "%.4a" format code
mDNS_snprintf(buffer, sizeof(buffer), "%d.%d.%d.%d.in-addr.arpa.", ip.b[3], ip.b[2], ip.b[1], ip.b[0]);
MakeDomainNameFromDNSNameString(&entry->revname, buffer);
}
return(entry);
}
mDNSlocal HostEntry *GotPacketFromHost(const mDNSAddr *addr, HostPkt_Type t, mDNSOpaque16 id)
{
if (ExactlyOneFilter) return(NULL);
else
{
HostList *list = (addr->type == mDNSAddrType_IPv4) ? &IPv4HostList : &IPv6HostList;
HostEntry *entry = FindHost(addr, list);
if (!entry) entry = AddHost(addr, list);
if (!entry) return(NULL);
// Don't count our own interrogation packets
if (id.NotAnInteger != 0xFFFF) entry->pkts[t]++;
return(entry);
}
}
mDNSlocal void RecordHostInfo(HostEntry *entry, const ResourceRecord *const pktrr)
{
if (!entry->hostname.c[0])
{
if (pktrr->rrtype == kDNSType_A || pktrr->rrtype == kDNSType_AAAA)
{
// Should really check that the rdata in the address record matches the source address of this packet
entry->NumQueries = 0;
AssignDomainName(&entry->hostname, pktrr->name);
}
if (pktrr->rrtype == kDNSType_PTR)
if (SameDomainName(&entry->revname, pktrr->name))
{
entry->NumQueries = 0;
AssignDomainName(&entry->hostname, &pktrr->rdata->u.name);
}
}
else if (pktrr->rrtype == kDNSType_HINFO)
{
RDataBody *rd = &pktrr->rdata->u;
mDNSu8 *rdend = (mDNSu8 *)rd + pktrr->rdlength;
mDNSu8 *hw = rd->txt.c;
mDNSu8 *sw = hw + 1 + (mDNSu32)hw[0];
if (sw + 1 + sw[0] <= rdend)
{
AssignDomainName(&entry->hostname, pktrr->name);
mDNSPlatformMemCopy(entry->HIHardware.c, hw, 1 + (mDNSu32)hw[0]);
mDNSPlatformMemCopy(entry->HISoftware.c, sw, 1 + (mDNSu32)sw[0]);
}
}
}
mDNSlocal void SendUnicastQuery(mDNS *const m, HostEntry *entry, domainname *name, mDNSu16 rrtype, mDNSInterfaceID InterfaceID)
{
const mDNSOpaque16 id = { { 0xFF, 0xFF } };
DNSMessage query;
mDNSu8 *qptr = query.data;
const mDNSu8 *const limit = query.data + sizeof(query.data);
const mDNSAddr *target = &entry->addr;
InitializeDNSMessage(&query.h, id, QueryFlags);
qptr = putQuestion(&query, qptr, limit, name, rrtype, kDNSClass_IN);
entry->LastQuery = m->timenow;
entry->NumQueries++;
// Note: When there are multiple mDNSResponder agents running on a single machine
// (e.g. Apple mDNSResponder plus a SliMP3 server with embedded mDNSResponder)
// it is possible that unicast queries may not go to the primary system responder.
// We try the first query using unicast, but if that doesn't work we try again via multicast.
if (entry->NumQueries > 2)
{
target = &AllDNSLinkGroup_v4;
}
else
{
//mprintf("%#a Q\n", target);
InterfaceID = mDNSInterface_Any; // Send query from our unicast reply socket
}
mDNSSendDNSMessage(m, &query, qptr, InterfaceID, mDNSNULL, target, MulticastDNSPort, mDNSNULL, mDNSNULL, mDNSfalse);
}
mDNSlocal void AnalyseHost(mDNS *const m, HostEntry *entry, const mDNSInterfaceID InterfaceID)
{
// If we've done four queries without answer, give up
if (entry->NumQueries >= 4) return;
// If we've done a query in the last second, give the host a chance to reply before trying again
if (entry->NumQueries && m->timenow - entry->LastQuery < mDNSPlatformOneSecond) return;
// If we don't know the host name, try to find that first
if (!entry->hostname.c[0])
{
if (entry->revname.c[0])
{
SendUnicastQuery(m, entry, &entry->revname, kDNSType_PTR, InterfaceID);
//mprintf("%##s PTR %d\n", entry->revname.c, entry->NumQueries);
}
}
// If we have the host name but no HINFO, now ask for that
else if (!entry->HIHardware.c[0])
{
SendUnicastQuery(m, entry, &entry->hostname, kDNSType_HINFO, InterfaceID);
//mprintf("%##s HINFO %d\n", entry->hostname.c, entry->NumQueries);
}
}
mDNSlocal int CompareHosts(const void *p1, const void *p2)
{
return (int)(HostEntryTotalPackets((HostEntry *)p2) - HostEntryTotalPackets((HostEntry *)p1));
}
mDNSlocal void ShowSortedHostList(HostList *list, int max)
{
HostEntry *e, *end = &list->hosts[(max < list->num) ? max : list->num];
qsort(list->hosts, list->num, sizeof(HostEntry), CompareHosts);
if (list->num) mprintf("\n%-25s%s%s\n", "Source Address", OPBanner, " Pkts Query LegacyQ Response");
for (e = &list->hosts[0]; e < end; e++)
{
int len = mprintf("%#-25a", &e->addr);
if (len > 25) mprintf("\n%25s", "");
mprintf("%8lu %8lu %8lu %8lu %8lu %8lu %8lu", e->totalops,
e->stat[OP_probe], e->stat[OP_goodbye],
e->stat[OP_browseq], e->stat[OP_browsea],
e->stat[OP_resolveq], e->stat[OP_resolvea]);
mprintf(" %8lu %8lu %8lu %8lu",
HostEntryTotalPackets(e), e->pkts[HostPkt_Q], e->pkts[HostPkt_L], e->pkts[HostPkt_R]);
if (e->pkts[HostPkt_B]) mprintf("Bad: %8lu", e->pkts[HostPkt_B]);
mprintf("\n");
if (!e->HISoftware.c[0] && e->NumQueries > 2)
mDNSPlatformMemCopy(&e->HISoftware, "\x27*** Unknown (Jaguar, Windows, etc.) ***", 0x28);
if (e->hostname.c[0] || e->HIHardware.c[0] || e->HISoftware.c[0])
mprintf("%##-45s %#-14s %#s\n", e->hostname.c, e->HIHardware.c, e->HISoftware.c);
}
}
//*************************************************************************************************************
// Receive and process packets
mDNSlocal mDNSBool ExtractServiceType(const domainname *const fqdn, domainname *const srvtype)
{
int i, len;
const mDNSu8 *src = fqdn->c;
mDNSu8 *dst = srvtype->c;
len = *src;
if (len == 0 || len >= 0x40) return(mDNSfalse);
if (src[1] != '_') src += 1 + len;
len = *src;
if (len == 0 || len >= 0x40 || src[1] != '_') return(mDNSfalse);
for (i=0; i<=len; i++) *dst++ = *src++;
len = *src;
if (len == 0 || len >= 0x40 || src[1] != '_') return(mDNSfalse);
for (i=0; i<=len; i++) *dst++ = *src++;
*dst++ = 0; // Put the null root label on the end of the service type
return(mDNStrue);
}
mDNSlocal void recordstat(HostEntry *entry, const domainname *fqdn, int op, mDNSu16 rrtype)
{
ActivityStat **s = &stats;
domainname srvtype;
if (op != OP_probe)
{
if (rrtype == kDNSType_SRV || rrtype == kDNSType_TXT) op = op - OP_browsegroup + OP_resolvegroup;
else if (rrtype != kDNSType_PTR) return;
}
if (!ExtractServiceType(fqdn, &srvtype)) return;
while (*s && !SameDomainName(&(*s)->srvtype, &srvtype)) s = &(*s)->next;
if (!*s)
{
int i;
*s = malloc(sizeof(ActivityStat));
if (!*s) exit(-1);
(*s)->next = NULL;
(*s)->srvtype = srvtype;
(*s)->printed = 0;
(*s)->totalops = 0;
for (i=0; i<OP_NumTypes; i++) (*s)->stat[i] = 0;
}
(*s)->totalops++;
(*s)->stat[op]++;
if (entry)
{
entry->totalops++;
entry->stat[op]++;
}
}
mDNSlocal void printstats(int max)
{
int i;
if (!stats) return;
for (i=0; i<max; i++)
{
int max_val = 0;
ActivityStat *s, *m = NULL;
for (s = stats; s; s=s->next)
if (!s->printed && max_val < s->totalops)
{ m = s; max_val = s->totalops; }
if (!m) return;
m->printed = mDNStrue;
if (i==0) mprintf("%-25s%s\n", "Service Type", OPBanner);
mprintf("%##-25s%8d %8d %8d %8d %8d %8d %8d\n", m->srvtype.c, m->totalops, m->stat[OP_probe],
m->stat[OP_goodbye], m->stat[OP_browseq], m->stat[OP_browsea], m->stat[OP_resolveq], m->stat[OP_resolvea]);
}
}
mDNSlocal const mDNSu8 *FindUpdate(mDNS *const m, const DNSMessage *const query, const mDNSu8 *ptr, const mDNSu8 *const end,
DNSQuestion *q, LargeCacheRecord *pkt)
{
int i;
for (i = 0; i < query->h.numAuthorities; i++)
{
const mDNSu8 *p2 = ptr;
ptr = GetLargeResourceRecord(m, query, ptr, end, q->InterfaceID, kDNSRecordTypePacketAuth, pkt);
if (!ptr) break;
if (m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative && ResourceRecordAnswersQuestion(&pkt->r.resrec, q)) return(p2);
}
return(mDNSNULL);
}
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)
{
const char *const ptype = (msg->h.flags.b[0] & kDNSFlag0_QR_Response) ? "-R- " :
(srcport.NotAnInteger == MulticastDNSPort.NotAnInteger) ? "-Q- " : "-LQ-";
const unsigned length = end - (mDNSu8 *)msg;
struct timeval tv;
struct tm tm;
const mDNSu32 index = mDNSPlatformInterfaceIndexfromInterfaceID(m, InterfaceID, mDNSfalse);
char if_name[IFNAMSIZ]; // Older Linux distributions don't define IF_NAMESIZE
if_indextoname(index, if_name);
gettimeofday(&tv, NULL);
localtime_r((time_t*)&tv.tv_sec, &tm);
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);
mprintf("%#-16a %s Q:%3d Ans:%3d Auth:%3d Add:%3d Size:%5d bytes",
srcaddr, ptype, msg->h.numQuestions, msg->h.numAnswers, msg->h.numAuthorities, msg->h.numAdditionals, length);
if (msg->h.id.NotAnInteger) mprintf(" ID:%u", mDNSVal16(msg->h.id));
if (!mDNSAddrIsDNSMulticast(dstaddr)) mprintf(" To: %#a", dstaddr);
if (msg->h.flags.b[0] & kDNSFlag0_TC)
{
if (msg->h.flags.b[0] & kDNSFlag0_QR_Response) mprintf(" Truncated");
else mprintf(" Truncated (KA list continues in next packet)");
}
mprintf("\n");
if (length < sizeof(DNSMessageHeader) + NormalMaxDNSMessageData - 192)
if (msg->h.flags.b[0] & kDNSFlag0_TC)
mprintf("%#-16a **** WARNING: Packet suspiciously small. Payload size (excluding IP and UDP headers)\n"
"%#-16a **** should usually be closer to %d bytes before truncation becomes necessary.\n",
srcaddr, srcaddr, sizeof(DNSMessageHeader) + NormalMaxDNSMessageData);
}
mDNSlocal void DisplaySizeCheck(const DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *srcaddr, int num_opts)
{
const unsigned length = end - (mDNSu8 *)msg;
const int num_records = msg->h.numAnswers + msg->h.numAuthorities + msg->h.numAdditionals - num_opts;
if (length > sizeof(DNSMessageHeader) + NormalMaxDNSMessageData)
if (num_records > 1)
mprintf("%#-16a **** ERROR: Oversized packet with %d records.\n"
"%#-16a **** Many network devices cannot receive packets larger than %d bytes.\n"
"%#-16a **** To minimize interoperability failures, oversized packets MUST be limited to a single resource record.\n",
srcaddr, num_records, srcaddr, 40 + 8 + sizeof(DNSMessageHeader) + NormalMaxDNSMessageData, srcaddr);
}
mDNSlocal void DisplayResourceRecord(const mDNSAddr *const srcaddr, const char *const op, const ResourceRecord *const pktrr)
{
static const char hexchars[16] = "0123456789ABCDEF";
#define MaxWidth 132
char buffer[MaxWidth+8];
char *p = buffer;
RDataBody *rd = &pktrr->rdata->u;
mDNSu8 *rdend = (mDNSu8 *)rd + pktrr->rdlength;
int n = mprintf("%#-16a %-5s %-5s%5lu %##s -> ", srcaddr, op, DNSTypeName(pktrr->rrtype), pktrr->rroriginalttl, pktrr->name->c);
if (pktrr->RecordType == kDNSRecordTypePacketNegative) { mprintf("**** ERROR: FAILED TO READ RDATA ****\n"); return; }
// The kDNSType_OPT case below just calls GetRRDisplayString_rdb
// Perhaps more (or all?) of the cases should do that?
switch(pktrr->rrtype)
{
case kDNSType_A: n += mprintf("%.4a", &rd->ipv4); break;
case kDNSType_PTR: n += mprintf("%##.*s", MaxWidth - n, rd->name.c); break;
case kDNSType_HINFO: // same as kDNSType_TXT below
case kDNSType_TXT: {
mDNSu8 *t = rd->txt.c;
while (t < rdend && t[0] && p < buffer+MaxWidth)
{
int i;
for (i=1; i<=t[0] && p < buffer+MaxWidth; i++)
{
if (t[i] == '\\') *p++ = '\\';
if (t[i] >= ' ') *p++ = t[i];
else
{
*p++ = '\\';
*p++ = '0';
*p++ = 'x';
*p++ = hexchars[t[i] >> 4];
*p++ = hexchars[t[i] & 0xF];
}
}
t += 1+t[0];
if (t < rdend && t[0]) { *p++ = '\\'; *p++ = ' '; }
}
*p++ = 0;
n += mprintf("%.*s", MaxWidth - n, buffer);
} break;
case kDNSType_AAAA: n += mprintf("%.16a", &rd->ipv6); break;
case kDNSType_SRV: n += mprintf("%##s:%d", rd->srv.target.c, mDNSVal16(rd->srv.port)); break;
case kDNSType_OPT: {
char b[MaxMsg];
// Quick hack: we don't want the prefix that GetRRDisplayString_rdb puts at the start of its
// string, because it duplicates the name and rrtype we already display, so we compute the
// length of that prefix and strip that many bytes off the beginning of the string we display.
mDNSu32 striplen = mDNS_snprintf(b, MaxMsg-1, "%4d %##s %s ", pktrr->rdlength, pktrr->name->c, DNSTypeName(pktrr->rrtype));
GetRRDisplayString_rdb(pktrr, &pktrr->rdata->u, b);
n += mprintf("%.*s", MaxWidth - n, b + striplen);
} break;
case kDNSType_NSEC: {
char b[MaxMsg];
// See the quick hack above
mDNSu32 striplen = mDNS_snprintf(b, MaxMsg-1, "%4d %##s %s ", pktrr->rdlength, pktrr->name->c, DNSTypeName(pktrr->rrtype));
GetRRDisplayString_rdb(pktrr, &pktrr->rdata->u, b);
n += mprintf("%s", b+striplen);
} break;
default: {
mDNSu8 *s = rd->data;
while (s < rdend && p < buffer+MaxWidth)
{
if (*s == '\\') *p++ = '\\';
if (*s >= ' ') *p++ = *s;
else
{
*p++ = '\\';
*p++ = '0';
*p++ = 'x';
*p++ = hexchars[*s >> 4];
*p++ = hexchars[*s & 0xF];
}
s++;
}
*p++ = 0;
n += mprintf("%.*s", MaxWidth - n, buffer);
} break;
}
mprintf("\n");
}
mDNSlocal void HexDump(const mDNSu8 *ptr, const mDNSu8 *const end)
{
while (ptr < end)
{
int i;
for (i=0; i<16; i++)
if (&ptr[i] < end) mprintf("%02X ", ptr[i]);
else mprintf(" ");
for (i=0; i<16; i++)
if (&ptr[i] < end) mprintf("%c", ptr[i] <= ' ' || ptr[i] >= 126 ? '.' : ptr[i]);
ptr += 16;
mprintf("\n");
}
}
mDNSlocal void DisplayError(const mDNSAddr *srcaddr, const mDNSu8 *ptr, const mDNSu8 *const end, char *msg)
{
mprintf("%#-16a **** ERROR: FAILED TO READ %s ****\n", srcaddr, msg);
HexDump(ptr, end);
}
mDNSlocal void DisplayQuery(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end,
const mDNSAddr *srcaddr, mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSInterfaceID InterfaceID)
{
int i;
int num_opts = 0;
const mDNSu8 *ptr = msg->data;
const mDNSu8 *auth = LocateAuthorities(msg, end);
mDNSBool MQ = (srcport.NotAnInteger == MulticastDNSPort.NotAnInteger);
HostEntry *entry = GotPacketFromHost(srcaddr, MQ ? HostPkt_Q : HostPkt_L, msg->h.id);
LargeCacheRecord pkt;
DisplayPacketHeader(m, msg, end, srcaddr, srcport, dstaddr, InterfaceID);
if (msg->h.id.NotAnInteger != 0xFFFF)
{
if (MQ) NumPktQ++; else NumPktL++;
}
for (i=0; i<msg->h.numQuestions; i++)
{
DNSQuestion q;
mDNSu8 *p2 = (mDNSu8 *)getQuestion(msg, ptr, end, InterfaceID, &q);
mDNSu16 ucbit = q.qclass & kDNSQClass_UnicastResponse;
q.qclass &= ~kDNSQClass_UnicastResponse;
if (!p2) { DisplayError(srcaddr, ptr, end, "QUESTION"); return; }
ptr = p2;
p2 = (mDNSu8 *)FindUpdate(m, msg, auth, end, &q, &pkt);
if (p2)
{
NumProbes++;
DisplayResourceRecord(srcaddr, ucbit ? "(PU)" : "(PM)", &pkt.r.resrec);
recordstat(entry, &q.qname, OP_probe, q.qtype);
p2 = (mDNSu8 *)skipDomainName(msg, p2, end);
// Having displayed this update record, clear type and class so we don't display the same one again.
p2[0] = p2[1] = p2[2] = p2[3] = 0;
}
else
{
const char *ptype = ucbit ? "(QU)" : "(QM)";
if (srcport.NotAnInteger == MulticastDNSPort.NotAnInteger) NumQuestions++;
else { NumLegacy++; ptype = "(LQ)"; }
mprintf("%#-16a %-5s %-5s %##s\n", srcaddr, ptype, DNSTypeName(q.qtype), q.qname.c);
if (msg->h.id.NotAnInteger != 0xFFFF) recordstat(entry, &q.qname, OP_query, q.qtype);
}
}
for (i=0; i<msg->h.numAnswers; i++)
{
const mDNSu8 *ep = ptr;
ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAns, &pkt);
if (!ptr) { DisplayError(srcaddr, ep, end, "KNOWN ANSWER"); return; }
DisplayResourceRecord(srcaddr, "(KA)", &pkt.r.resrec);
if (pkt.r.resrec.rrtype == kDNSType_OPT)
{ num_opts++; mprintf("%#-16a **** ERROR: OPT RECORD IN ANSWER SECTION ****\n", srcaddr); }
// In the case of queries with long multi-packet KA lists, we count each subsequent KA packet
// the same as a single query, to more accurately reflect the burden on the network
// (A query with a six-packet KA list is *at least* six times the burden on the network as a single-packet query.)
if (msg->h.numQuestions == 0 && i == 0)
recordstat(entry, pkt.r.resrec.name, OP_query, pkt.r.resrec.rrtype);
}
for (i=0; i<msg->h.numAuthorities; i++)
{
const mDNSu8 *ep = ptr;
ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAuth, &pkt);
if (!ptr) { DisplayError(srcaddr, ep, end, "AUTHORITY"); return; }
// After we display an Update record with its matching question (above) we zero out its type and class
// If any remain that haven't been zero'd out, display them here
if (pkt.r.resrec.rrtype || pkt.r.resrec.rrclass) DisplayResourceRecord(srcaddr, "(AU)", &pkt.r.resrec);
if (pkt.r.resrec.rrtype == kDNSType_OPT)
{ num_opts++; mprintf("%#-16a **** ERROR: OPT RECORD IN AUTHORITY SECTION ****\n", srcaddr); }
}
for (i=0; i<msg->h.numAdditionals; i++)
{
const mDNSu8 *ep = ptr;
ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAdd, &pkt);
if (!ptr) { DisplayError(srcaddr, ep, end, "ADDITIONAL"); return; }
DisplayResourceRecord(srcaddr, pkt.r.resrec.rrtype == kDNSType_OPT ? "(OP)" : "(AD)", &pkt.r.resrec);
if (pkt.r.resrec.rrtype == kDNSType_OPT) num_opts++;
}
DisplaySizeCheck(msg, end, srcaddr, num_opts);
// We don't hexdump the DNSMessageHeader here because those six fields (id, flags, numQuestions, numAnswers, numAuthorities, numAdditionals)
// have already been swapped to host byte order and displayed, so including them in the hexdump is confusing
if (num_opts > 1) { mprintf("%#-16a **** ERROR: MULTIPLE OPT RECORDS ****\n", srcaddr); HexDump(msg->data, end); }
if (entry) AnalyseHost(m, entry, InterfaceID);
}
mDNSlocal void DisplayResponse(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *end,
const mDNSAddr *srcaddr, mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSInterfaceID InterfaceID)
{
int i;
int num_opts = 0;
const mDNSu8 *ptr = msg->data;
HostEntry *entry = GotPacketFromHost(srcaddr, HostPkt_R, msg->h.id);
LargeCacheRecord pkt;
DisplayPacketHeader(m, msg, end, srcaddr, srcport, dstaddr, InterfaceID);
if (msg->h.id.NotAnInteger != 0xFFFF) NumPktR++;
for (i=0; i<msg->h.numQuestions; i++)
{
DNSQuestion q;
const mDNSu8 *ep = ptr;
ptr = getQuestion(msg, ptr, end, InterfaceID, &q);
if (!ptr) { DisplayError(srcaddr, ep, end, "QUESTION"); return; }
if (mDNSAddrIsDNSMulticast(dstaddr))
mprintf("%#-16a (?) **** ERROR: SHOULD NOT HAVE Q IN mDNS RESPONSE **** %-5s %##s\n", srcaddr, DNSTypeName(q.qtype), q.qname.c);
else
mprintf("%#-16a (Q) %-5s %##s\n", srcaddr, DNSTypeName(q.qtype), q.qname.c);
}
for (i=0; i<msg->h.numAnswers; i++)
{
const mDNSu8 *ep = ptr;
ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAns, &pkt);
if (!ptr) { DisplayError(srcaddr, ep, end, "ANSWER"); return; }
if (pkt.r.resrec.rroriginalttl)
{
NumAnswers++;
DisplayResourceRecord(srcaddr, (pkt.r.resrec.RecordType & kDNSRecordTypePacketUniqueMask) ? "(AN)" : "(AN+)", &pkt.r.resrec);
if (msg->h.id.NotAnInteger != 0xFFFF) recordstat(entry, pkt.r.resrec.name, OP_answer, pkt.r.resrec.rrtype);
if (entry) RecordHostInfo(entry, &pkt.r.resrec);
}
else
{
NumGoodbyes++;
DisplayResourceRecord(srcaddr, "(DE)", &pkt.r.resrec);
recordstat(entry, pkt.r.resrec.name, OP_goodbye, pkt.r.resrec.rrtype);
}
if (pkt.r.resrec.rrtype == kDNSType_OPT)
{ num_opts++; mprintf("%#-16a **** ERROR: OPT RECORD IN ANSWER SECTION ****\n", srcaddr); }
}
for (i=0; i<msg->h.numAuthorities; i++)
{
const mDNSu8 *ep = ptr;
ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAuth, &pkt);
if (!ptr) { DisplayError(srcaddr, ep, end, "AUTHORITY"); return; }
DisplayResourceRecord(srcaddr, "(AU)", &pkt.r.resrec);
if (pkt.r.resrec.rrtype == kDNSType_OPT)
{ num_opts++; mprintf("%#-16a **** ERROR: OPT RECORD IN AUTHORITY SECTION ****\n", srcaddr); }
else if (pkt.r.resrec.rrtype != kDNSType_NSEC3)
mprintf("%#-16a (?) **** ERROR: SHOULD NOT HAVE AUTHORITY IN mDNS RESPONSE **** %-5s %##s\n",
srcaddr, DNSTypeName(pkt.r.resrec.rrtype), pkt.r.resrec.name->c);
}
for (i=0; i<msg->h.numAdditionals; i++)
{
const mDNSu8 *ep = ptr;
ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAdd, &pkt);
if (!ptr) { DisplayError(srcaddr, ep, end, "ADDITIONAL"); return; }
NumAdditionals++;
if (pkt.r.resrec.rrtype == kDNSType_OPT) num_opts++;
DisplayResourceRecord(srcaddr,
pkt.r.resrec.rrtype == kDNSType_OPT ? "(OP)" : (pkt.r.resrec.RecordType & kDNSRecordTypePacketUniqueMask) ? "(AD)" : "(AD+)",
&pkt.r.resrec);
if (entry) RecordHostInfo(entry, &pkt.r.resrec);
}
DisplaySizeCheck(msg, end, srcaddr, num_opts);
// We don't hexdump the DNSMessageHeader here because those six fields (id, flags, numQuestions, numAnswers, numAuthorities, numAdditionals)
// have already been swapped to host byte order and displayed, so including them in the hexdump is confusing
if (num_opts > 1) { mprintf("%#-16a **** ERROR: MULTIPLE OPT RECORDS ****\n", srcaddr); HexDump(msg->data, end); }
if (entry) AnalyseHost(m, entry, InterfaceID);
}
mDNSlocal void ProcessUnicastResponse(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *end, const mDNSAddr *srcaddr, const mDNSInterfaceID InterfaceID)
{
int i;
const mDNSu8 *ptr = LocateAnswers(msg, end);
HostEntry *entry = GotPacketFromHost(srcaddr, HostPkt_R, msg->h.id);
//mprintf("%#a R\n", srcaddr);
for (i=0; i<msg->h.numAnswers + msg->h.numAuthorities + msg->h.numAdditionals; i++)
{
LargeCacheRecord pkt;
ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAns, &pkt);
if (ptr && pkt.r.resrec.rroriginalttl && entry) RecordHostInfo(entry, &pkt.r.resrec);
}
}
mDNSlocal mDNSBool AddressMatchesFilterList(const mDNSAddr *srcaddr)
{
FilterList *f;
if (!Filters) return(srcaddr->type == AddressType);
for (f=Filters; f; f=f->next) if (mDNSSameAddress(srcaddr, &f->FilterAddr)) return(mDNStrue);
return(mDNSfalse);
}
mDNSexport void mDNSCoreReceive(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end,
const mDNSAddr *srcaddr, mDNSIPPort srcport, const mDNSAddr *dstaddr, mDNSIPPort dstport, const mDNSInterfaceID InterfaceID)
{
const mDNSu8 StdQ = kDNSFlag0_QR_Query | kDNSFlag0_OP_StdQuery;
const mDNSu8 StdR = kDNSFlag0_QR_Response | kDNSFlag0_OP_StdQuery;
const mDNSu8 QR_OP = (mDNSu8)(msg->h.flags.b[0] & kDNSFlag0_QROP_Mask);
mDNSu8 *ptr = (mDNSu8 *)&msg->h.numQuestions;
int goodinterface = (FilterInterface == 0);
(void)dstaddr; // Unused
(void)dstport; // Unused
// Read the integer parts which are in IETF byte-order (MSB first, LSB second)
msg->h.numQuestions = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]);
msg->h.numAnswers = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]);
msg->h.numAuthorities = (mDNSu16)((mDNSu16)ptr[4] << 8 | ptr[5]);
msg->h.numAdditionals = (mDNSu16)((mDNSu16)ptr[6] << 8 | ptr[7]);
// For now we're only interested in monitoring IPv4 traffic.
// All IPv6 packets should just be duplicates of the v4 packets.
if (!goodinterface) goodinterface = (FilterInterface == (int)mDNSPlatformInterfaceIndexfromInterfaceID(m, InterfaceID, mDNSfalse));
if (goodinterface && AddressMatchesFilterList(srcaddr))
{
mDNS_Lock(m);
if (!mDNSAddrIsDNSMulticast(dstaddr))
{
if (QR_OP == StdQ) mprintf("Unicast query from %#a\n", srcaddr);
else if (QR_OP == StdR) ProcessUnicastResponse(m, msg, end, srcaddr, InterfaceID);
}
else
{
if (QR_OP == StdQ) DisplayQuery (m, msg, end, srcaddr, srcport, dstaddr, InterfaceID);
else if (QR_OP == StdR) DisplayResponse (m, msg, end, srcaddr, srcport, dstaddr, InterfaceID);
else
{
debugf("Unknown DNS packet type %02X%02X (ignored)", msg->h.flags.b[0], msg->h.flags.b[1]);
GotPacketFromHost(srcaddr, HostPkt_B, msg->h.id);
NumPktB++;
}
}
mDNS_Unlock(m);
}
}
mDNSlocal mStatus mDNSNetMonitor(void)
{
struct tm tm;
int h, m, s, mul, div, TotPkt;
#if !defined(WIN32)
sigset_t signals;
#endif
mStatus status = mDNS_Init(&mDNSStorage, &PlatformStorage,
mDNS_Init_NoCache, mDNS_Init_ZeroCacheSize,
mDNS_Init_DontAdvertiseLocalAddresses,
mDNS_Init_NoInitCallback, mDNS_Init_NoInitCallbackContext);
if (status) return(status);
gettimeofday(&tv_start, NULL);
#if defined( WIN32 )
status = SetupInterfaceList(&mDNSStorage);
if (status) return(status);
gStopEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
if (gStopEvent == INVALID_HANDLE_VALUE) return mStatus_UnknownErr;
mDNSPollRegisterEvent( gStopEvent, StopNotification, NULL );
if (!SetConsoleCtrlHandler(ConsoleControlHandler, TRUE)) return mStatus_UnknownErr;
gRunning = mDNStrue; while (gRunning) mDNSPoll( INFINITE );
if (!SetConsoleCtrlHandler(ConsoleControlHandler, FALSE)) return mStatus_UnknownErr;
CloseHandle(gStopEvent);
#else
mDNSPosixListenForSignalInEventLoop(SIGINT);
mDNSPosixListenForSignalInEventLoop(SIGTERM);
do
{
struct timeval timeout = { FutureTime, 0 }; // wait until SIGINT or SIGTERM
mDNSBool gotSomething;
mDNSPosixRunEventLoopOnce(&mDNSStorage, &timeout, &signals, &gotSomething);
}
while ( !( sigismember( &signals, SIGINT) || sigismember( &signals, SIGTERM)));
#endif
// Now display final summary
TotPkt = NumPktQ + NumPktL + NumPktR;
gettimeofday(&tv_end, NULL);
tv_interval = tv_end;
if (tv_start.tv_usec > tv_interval.tv_usec)
{ tv_interval.tv_usec += 1000000; tv_interval.tv_sec--; }
tv_interval.tv_sec -= tv_start.tv_sec;
tv_interval.tv_usec -= tv_start.tv_usec;
h = (tv_interval.tv_sec / 3600);
m = (tv_interval.tv_sec % 3600) / 60;
s = (tv_interval.tv_sec % 60);
if (tv_interval.tv_sec > 10)
{
mul = 60;
div = tv_interval.tv_sec;
}
else
{
mul = 60000;
div = tv_interval.tv_sec * 1000 + tv_interval.tv_usec / 1000;
if (div == 0) div=1;
}
mprintf("\n\n");
localtime_r((time_t*)&tv_start.tv_sec, &tm);
mprintf("Started %3d:%02d:%02d.%06d\n", tm.tm_hour, tm.tm_min, tm.tm_sec, tv_start.tv_usec);
localtime_r((time_t*)&tv_end.tv_sec, &tm);
mprintf("End %3d:%02d:%02d.%06d\n", tm.tm_hour, tm.tm_min, tm.tm_sec, tv_end.tv_usec);
mprintf("Captured for %3d:%02d:%02d.%06d\n", h, m, s, tv_interval.tv_usec);
if (!Filters)
{
mprintf("Unique source addresses seen on network:");
if (IPv4HostList.num) mprintf(" %ld (IPv4)", IPv4HostList.num);
if (IPv6HostList.num) mprintf(" %ld (IPv6)", IPv6HostList.num);
if (!IPv4HostList.num && !IPv6HostList.num) mprintf(" None");
mprintf("\n");
}
mprintf("\n");
mprintf("Modern Query Packets: %7d (avg%5d/min)\n", NumPktQ, NumPktQ * mul / div);
mprintf("Legacy Query Packets: %7d (avg%5d/min)\n", NumPktL, NumPktL * mul / div);
mprintf("Multicast Response Packets: %7d (avg%5d/min)\n", NumPktR, NumPktR * mul / div);
mprintf("Total Multicast Packets: %7d (avg%5d/min)\n", TotPkt, TotPkt * mul / div);
mprintf("\n");
mprintf("Total New Service Probes: %7d (avg%5d/min)\n", NumProbes, NumProbes * mul / div);
mprintf("Total Goodbye Announcements: %7d (avg%5d/min)\n", NumGoodbyes, NumGoodbyes * mul / div);
mprintf("Total Query Questions: %7d (avg%5d/min)\n", NumQuestions, NumQuestions * mul / div);
mprintf("Total Queries from Legacy Clients:%7d (avg%5d/min)\n", NumLegacy, NumLegacy * mul / div);
mprintf("Total Answers/Announcements: %7d (avg%5d/min)\n", NumAnswers, NumAnswers * mul / div);
mprintf("Total Additional Records: %7d (avg%5d/min)\n", NumAdditionals, NumAdditionals * mul / div);
mprintf("\n");
printstats(kReportTopServices);
if (!ExactlyOneFilter)
{
ShowSortedHostList(&IPv4HostList, kReportTopHosts);
ShowSortedHostList(&IPv6HostList, kReportTopHosts);
}
mDNS_Close(&mDNSStorage);
return(0);
}
mDNSexport int main(int argc, char **argv)
{
const char *progname = strrchr(argv[0], '/') ? strrchr(argv[0], '/') + 1 : argv[0];
int i;
mStatus status;
#if defined(WIN32)
HeapSetInformation(NULL, HeapEnableTerminationOnCorruption, NULL, 0);
#endif
setlinebuf(stdout); // Want to see lines as they appear, not block buffered
for (i=1; i<argc; i++)
{
if (i+1 < argc && !strcmp(argv[i], "-i"))
{
FilterInterface = if_nametoindex(argv[i+1]);
if (!FilterInterface) FilterInterface = atoi(argv[i+1]);
if (!FilterInterface) {
fprintf(stderr, "Unknown interface %s\n", argv[i+1]);
goto usage;
}
printf("Monitoring interface %d/%s\n", FilterInterface, argv[i+1]);
i += 1;
}
else if (!strcmp(argv[i], "-6"))
{
AddressType = mDNSAddrType_IPv6;
printf("Monitoring IPv6 traffic\n");
}
else
{
struct in_addr s4;
struct in6_addr s6;
FilterList *f;
mDNSAddr a;
a.type = mDNSAddrType_IPv4;
if (inet_pton(AF_INET, argv[i], &s4) == 1)
a.ip.v4.NotAnInteger = s4.s_addr;
else if (inet_pton(AF_INET6, argv[i], &s6) == 1)
{
a.type = mDNSAddrType_IPv6;
mDNSPlatformMemCopy(&a.ip.v6, &s6, sizeof(a.ip.v6));
}
else
{
struct hostent *h = gethostbyname(argv[i]);
if (h) a.ip.v4.NotAnInteger = *(long*)h->h_addr;
else goto usage;
}
f = malloc(sizeof(*f));
f->FilterAddr = a;
f->next = Filters;
Filters = f;
}
}
status = mDNSNetMonitor();
if (status) { fprintf(stderr, "%s: mDNSNetMonitor failed %d\n", progname, (int)status); return(status); }
return(0);
usage:
fprintf(stderr, "\nmDNS traffic monitor\n");
fprintf(stderr, "Usage: %s [-i index] [-6] [host]\n", progname);
fprintf(stderr, "Optional [-i index] parameter displays only packets from that interface index\n");
fprintf(stderr, "Optional [-6] parameter displays only ipv6 packets (defaults to only ipv4 packets)\n");
fprintf(stderr, "Optional [host] parameter displays only packets from that host\n");
fprintf(stderr, "\nPer-packet header output:\n");
fprintf(stderr, "-Q- Multicast Query from mDNS client that accepts multicast responses\n");
fprintf(stderr, "-R- Multicast Response packet containing answers/announcements\n");
fprintf(stderr, "-LQ- Multicast Query from legacy client that does *not* listen for multicast responses\n");
fprintf(stderr, "Q/Ans/Auth/Add Number of questions, answers, authority records and additional records in packet\n");
fprintf(stderr, "\nPer-record display:\n");
fprintf(stderr, "(PM) Probe Question (new service starting), requesting multicast response\n");
fprintf(stderr, "(PU) Probe Question (new service starting), requesting unicast response\n");
fprintf(stderr, "(DE) Deletion/Goodbye (service going away)\n");
fprintf(stderr, "(LQ) Legacy Query Question\n");
fprintf(stderr, "(QM) Query Question, requesting multicast response\n");
fprintf(stderr, "(QU) Query Question, requesting unicast response\n");
fprintf(stderr, "(KA) Known Answer (information querier already knows)\n");
fprintf(stderr, "(AN) Unique Answer to question (or periodic announcment) (entire RR Set)\n");
fprintf(stderr, "(AN+) Answer to question (or periodic announcment) (add to existing RR Set members)\n");
fprintf(stderr, "(AD) Unique Additional Record Set (entire RR Set)\n");
fprintf(stderr, "(AD+) Additional records (add to existing RR Set members)\n");
fprintf(stderr, "\nFinal summary, sorted by service type:\n");
fprintf(stderr, "Probe Probes for this service type starting up\n");
fprintf(stderr, "Goodbye Goodbye (deletion) packets for this service type shutting down\n");
fprintf(stderr, "BrowseQ Browse questions from clients browsing to find a list of instances of this service\n");
fprintf(stderr, "BrowseA Browse answers/announcments advertising instances of this service\n");
fprintf(stderr, "ResolveQ Resolve questions from clients actively connecting to an instance of this service\n");
fprintf(stderr, "ResolveA Resolve answers/announcments giving connection information for an instance of this service\n");
fprintf(stderr, "\n");
return(-1);
}
