dns-sd.c   [plain text]


/* -*- Mode: C; tab-width: 4 -*-
 *
 * Copyright (c) 2002-2008 Apple Inc. All rights reserved.
 *
 * Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple Computer, Inc.
 * ("Apple") in consideration of your agreement to the following terms, and your
 * use, installation, modification or redistribution of this Apple software
 * constitutes acceptance of these terms.  If you do not agree with these terms,
 * please do not use, install, modify or redistribute this Apple software.
 *
 * In consideration of your agreement to abide by the following terms, and subject
 * to these terms, Apple grants you a personal, non-exclusive license, under Apple's
 * copyrights in this original Apple software (the "Apple Software"), to use,
 * reproduce, modify and redistribute the Apple Software, with or without
 * modifications, in source and/or binary forms; provided that if you redistribute
 * the Apple Software in its entirety and without modifications, you must retain
 * this notice and the following text and disclaimers in all such redistributions of
 * the Apple Software.  Neither the name, trademarks, service marks or logos of
 * Apple Computer, Inc. may be used to endorse or promote products derived from the
 * Apple Software without specific prior written permission from Apple.  Except as
 * expressly stated in this notice, no other rights or licenses, express or implied,
 * are granted by Apple herein, including but not limited to any patent rights that
 * may be infringed by your derivative works or by other works in which the Apple
 * Software may be incorporated.
 *
 * The Apple Software is provided by Apple on an "AS IS" basis.  APPLE MAKES NO
 * WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
 * WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN
 * COMBINATION WITH YOUR PRODUCTS.
 *
 * IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION
 * OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER UNDER THEORY OF CONTRACT, TORT
 * (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
   To build this tool, copy and paste the following into a command line:

   OS X:
   gcc dns-sd.c -o dns-sd

   POSIX systems:
   gcc dns-sd.c -o dns-sd -I../mDNSShared -ldns_sd

   Windows:
   cl dns-sd.c -I../mDNSShared -DNOT_HAVE_GETOPT ws2_32.lib ..\mDNSWindows\DLL\Release\dnssd.lib
   (may require that you run a Visual Studio script such as vsvars32.bat first)
 */

// For testing changes to dnssd_clientstub.c, uncomment this line and the code will be compiled
// with an embedded copy of the client stub instead of linking the system library version at runtime.
// This also useful to work around link errors when you're working on an older version of Mac OS X,
// and trying to build a newer version of the "dns-sd" command which uses new API entry points that
// aren't in the system's /usr/lib/libSystem.dylib.
//#define TEST_NEW_CLIENTSTUB 1

// When building mDNSResponder for Mac OS X 10.4 and earlier, /usr/lib/libSystem.dylib is built using its own private
// copy of dnssd_clientstub.c, which is old and doesn't have all the entry points defined in the latest version, so
// when we're building dns-sd.c on Mac OS X 10.4 or earlier, we automatically set TEST_NEW_CLIENTSTUB so that we'll
// embed a copy of the latest dnssd_clientstub.c instead of trying to link to the incomplete version in libSystem.dylib
#if defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ <= 1040
#define TEST_NEW_CLIENTSTUB 1
#endif

#include <ctype.h>
#include <stdio.h>          // For stdout, stderr
#include <stdlib.h>         // For exit()
#include <string.h>         // For strlen(), strcpy()
#include <errno.h>          // For errno, EINTR
#include <time.h>
#include <sys/types.h>      // For u_char

#ifdef _WIN32
    #include <winsock2.h>
    #include <ws2tcpip.h>
    #include <Iphlpapi.h>
    #include <process.h>
typedef int pid_t;
    #define getpid     _getpid
    #define strcasecmp _stricmp
    #define snprintf   _snprintf
static const char kFilePathSep = '\\';
    #ifndef HeapEnableTerminationOnCorruption
    #     define HeapEnableTerminationOnCorruption (HEAP_INFORMATION_CLASS)1
    #endif
    #if !defined(IFNAMSIZ)
     #define IFNAMSIZ 16
    #endif
    #define if_nametoindex if_nametoindex_win
    #define if_indextoname if_indextoname_win

typedef PCHAR (WINAPI * if_indextoname_funcptr_t)(ULONG index, PCHAR name);
typedef ULONG (WINAPI * if_nametoindex_funcptr_t)(PCSTR name);

unsigned if_nametoindex_win(const char *ifname)
{
    HMODULE library;
    unsigned index = 0;

    // Try and load the IP helper library dll
    if ((library = LoadLibrary(TEXT("Iphlpapi")) ) != NULL )
    {
        if_nametoindex_funcptr_t if_nametoindex_funcptr;

        // On Vista and above there is a Posix like implementation of if_nametoindex
        if ((if_nametoindex_funcptr = (if_nametoindex_funcptr_t) GetProcAddress(library, "if_nametoindex")) != NULL )
        {
            index = if_nametoindex_funcptr(ifname);
        }

        FreeLibrary(library);
    }

    return index;
}

char * if_indextoname_win( unsigned ifindex, char *ifname)
{
    HMODULE library;
    char * name = NULL;

    // Try and load the IP helper library dll
    if ((library = LoadLibrary(TEXT("Iphlpapi")) ) != NULL )
    {
        if_indextoname_funcptr_t if_indextoname_funcptr;

        // On Vista and above there is a Posix like implementation of if_indextoname
        if ((if_indextoname_funcptr = (if_indextoname_funcptr_t) GetProcAddress(library, "if_indextoname")) != NULL )
        {
            name = if_indextoname_funcptr(ifindex, ifname);
        }

        FreeLibrary(library);
    }

    return name;
}

static size_t _sa_len(const struct sockaddr *addr)
{
    if (addr->sa_family == AF_INET) return (sizeof(struct sockaddr_in));
    else if (addr->sa_family == AF_INET6) return (sizeof(struct sockaddr_in6));
    else return (sizeof(struct sockaddr));
}

#   define SA_LEN(addr) (_sa_len(addr))

#else
    #include <unistd.h>         // For getopt() and optind
    #include <netdb.h>          // For getaddrinfo()
    #include <sys/time.h>       // For struct timeval
    #include <sys/socket.h>     // For AF_INET
    #include <netinet/in.h>     // For struct sockaddr_in()
    #include <arpa/inet.h>      // For inet_addr()
    #include <net/if.h>         // For if_nametoindex()
static const char kFilePathSep = '/';
// #ifndef NOT_HAVE_SA_LEN
//  #define SA_LEN(addr) ((addr)->sa_len)
// #else
    #define SA_LEN(addr) (((addr)->sa_family == AF_INET6) ? sizeof(struct sockaddr_in6) : sizeof(struct sockaddr_in))
// #endif
#endif

#if (TEST_NEW_CLIENTSTUB && !defined(__APPLE_API_PRIVATE))
#define __APPLE_API_PRIVATE 1
#endif

// DNSServiceSetDispatchQueue is not supported on 10.6 & prior
#if !TEST_NEW_CLIENTSTUB && defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && (__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ - (__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ % 10) <= 1060)
#undef _DNS_SD_LIBDISPATCH
#endif
#include "dns_sd.h"
#include "ClientCommon.h"

#if TEST_NEW_CLIENTSTUB
#include "../mDNSShared/dnssd_ipc.c"
#include "../mDNSShared/dnssd_clientlib.c"
#include "../mDNSShared/dnssd_clientstub.c"
#endif

// The "+0" is to cope with the case where _DNS_SD_H is defined but empty (e.g. on Mac OS X 10.4 and earlier)
#if _DNS_SD_H+0 >= 116
#define HAS_NAT_PMP_API 1
#define HAS_ADDRINFO_API 1
#else
#define kDNSServiceFlagsReturnIntermediates 0
#endif

//*************************************************************************************************************
// Globals

typedef union { unsigned char b[2]; unsigned short NotAnInteger; } Opaque16;

static int operation;
static uint32_t opinterface = kDNSServiceInterfaceIndexAny;
static DNSServiceRef client    = NULL;
static DNSServiceRef client_pa = NULL;  // DNSServiceRef for RegisterProxyAddressRecord
static DNSServiceRef sc1, sc2, sc3;     // DNSServiceRefs for kDNSServiceFlagsShareConnection testing

static int num_printed;
static char addtest = 0;
static DNSRecordRef record = NULL;
static char myhinfoW[14] = "\002PC\012Windows XP";
static char myhinfoX[ 9] = "\003Mac\004OS X";
static char updatetest[3] = "\002AA";
static char bigNULL[8192];  // 8K is maximum rdata we support

#if _DNS_SD_LIBDISPATCH
dispatch_queue_t main_queue;
dispatch_source_t timer_source;
#endif

// Note: the select() implementation on Windows (Winsock2) fails with any timeout much larger than this
#define LONG_TIME 100000000

static volatile int stopNow = 0;
static volatile int timeOut = LONG_TIME;

#if _DNS_SD_LIBDISPATCH
#define EXIT_IF_LIBDISPATCH_FATAL_ERROR(E) \
    if (main_queue && (E) == kDNSServiceErr_ServiceNotRunning) { fprintf(stderr, "Error code %d\n", (E)); exit(0); }
#else
#define EXIT_IF_LIBDISPATCH_FATAL_ERROR(E)
#endif

//*************************************************************************************************************
// Supporting Utility Functions

static uint16_t GetRRType(const char *s)
{
    if      (!strcasecmp(s, "A"       )) return(kDNSServiceType_A);
    else if (!strcasecmp(s, "NS"      )) return(kDNSServiceType_NS);
    else if (!strcasecmp(s, "MD"      )) return(kDNSServiceType_MD);
    else if (!strcasecmp(s, "MF"      )) return(kDNSServiceType_MF);
    else if (!strcasecmp(s, "CNAME"   )) return(kDNSServiceType_CNAME);
    else if (!strcasecmp(s, "SOA"     )) return(kDNSServiceType_SOA);
    else if (!strcasecmp(s, "MB"      )) return(kDNSServiceType_MB);
    else if (!strcasecmp(s, "MG"      )) return(kDNSServiceType_MG);
    else if (!strcasecmp(s, "MR"      )) return(kDNSServiceType_MR);
    else if (!strcasecmp(s, "NULL"    )) return(kDNSServiceType_NULL);
    else if (!strcasecmp(s, "WKS"     )) return(kDNSServiceType_WKS);
    else if (!strcasecmp(s, "PTR"     )) return(kDNSServiceType_PTR);
    else if (!strcasecmp(s, "HINFO"   )) return(kDNSServiceType_HINFO);
    else if (!strcasecmp(s, "MINFO"   )) return(kDNSServiceType_MINFO);
    else if (!strcasecmp(s, "MX"      )) return(kDNSServiceType_MX);
    else if (!strcasecmp(s, "TXT"     )) return(kDNSServiceType_TXT);
    else if (!strcasecmp(s, "RP"      )) return(kDNSServiceType_RP);
    else if (!strcasecmp(s, "AFSDB"   )) return(kDNSServiceType_AFSDB);
    else if (!strcasecmp(s, "X25"     )) return(kDNSServiceType_X25);
    else if (!strcasecmp(s, "ISDN"    )) return(kDNSServiceType_ISDN);
    else if (!strcasecmp(s, "RT"      )) return(kDNSServiceType_RT);
    else if (!strcasecmp(s, "NSAP"    )) return(kDNSServiceType_NSAP);
    else if (!strcasecmp(s, "NSAP_PTR")) return(kDNSServiceType_NSAP_PTR);
    else if (!strcasecmp(s, "SIG"     )) return(kDNSServiceType_SIG);
    else if (!strcasecmp(s, "KEY"     )) return(kDNSServiceType_KEY);
    else if (!strcasecmp(s, "PX"      )) return(kDNSServiceType_PX);
    else if (!strcasecmp(s, "GPOS"    )) return(kDNSServiceType_GPOS);
    else if (!strcasecmp(s, "AAAA"    )) return(kDNSServiceType_AAAA);
    else if (!strcasecmp(s, "LOC"     )) return(kDNSServiceType_LOC);
    else if (!strcasecmp(s, "NXT"     )) return(kDNSServiceType_NXT);
    else if (!strcasecmp(s, "EID"     )) return(kDNSServiceType_EID);
    else if (!strcasecmp(s, "NIMLOC"  )) return(kDNSServiceType_NIMLOC);
    else if (!strcasecmp(s, "SRV"     )) return(kDNSServiceType_SRV);
    else if (!strcasecmp(s, "ATMA"    )) return(kDNSServiceType_ATMA);
    else if (!strcasecmp(s, "NAPTR"   )) return(kDNSServiceType_NAPTR);
    else if (!strcasecmp(s, "KX"      )) return(kDNSServiceType_KX);
    else if (!strcasecmp(s, "CERT"    )) return(kDNSServiceType_CERT);
    else if (!strcasecmp(s, "A6"      )) return(kDNSServiceType_A6);
    else if (!strcasecmp(s, "DNAME"   )) return(kDNSServiceType_DNAME);
    else if (!strcasecmp(s, "SINK"    )) return(kDNSServiceType_SINK);
    else if (!strcasecmp(s, "OPT"     )) return(kDNSServiceType_OPT);
    else if (!strcasecmp(s, "TKEY"    )) return(kDNSServiceType_TKEY);
    else if (!strcasecmp(s, "TSIG"    )) return(kDNSServiceType_TSIG);
    else if (!strcasecmp(s, "IXFR"    )) return(kDNSServiceType_IXFR);
    else if (!strcasecmp(s, "AXFR"    )) return(kDNSServiceType_AXFR);
    else if (!strcasecmp(s, "MAILB"   )) return(kDNSServiceType_MAILB);
    else if (!strcasecmp(s, "MAILA"   )) return(kDNSServiceType_MAILA);
    else if (!strcasecmp(s, "dnskey"  )) return(kDNSServiceType_DNSKEY);
    else if (!strcasecmp(s, "ds"      )) return(kDNSServiceType_DS);
    else if (!strcasecmp(s, "rrsig"   )) return(kDNSServiceType_RRSIG);
    else if (!strcasecmp(s, "nsec"    )) return(kDNSServiceType_NSEC);
    else if (!strcasecmp(s, "ANY"     )) return(kDNSServiceType_ANY);
    else return(atoi(s));
}

#if HAS_NAT_PMP_API | HAS_ADDRINFO_API
static DNSServiceProtocol GetProtocol(const char *s)
{
    if      (!strcasecmp(s, "v4"      )) return(kDNSServiceProtocol_IPv4);
    else if (!strcasecmp(s, "v6"      )) return(kDNSServiceProtocol_IPv6);
    else if (!strcasecmp(s, "v4v6"    )) return(kDNSServiceProtocol_IPv4 | kDNSServiceProtocol_IPv6);
    else if (!strcasecmp(s, "v6v4"    )) return(kDNSServiceProtocol_IPv4 | kDNSServiceProtocol_IPv6);
    else if (!strcasecmp(s, "udp"     )) return(kDNSServiceProtocol_UDP);
    else if (!strcasecmp(s, "tcp"     )) return(kDNSServiceProtocol_TCP);
    else if (!strcasecmp(s, "udptcp"  )) return(kDNSServiceProtocol_UDP | kDNSServiceProtocol_TCP);
    else if (!strcasecmp(s, "tcpudp"  )) return(kDNSServiceProtocol_UDP | kDNSServiceProtocol_TCP);
    else return(atoi(s));
}
#endif

//*************************************************************************************************************
// Sample callback functions for each of the operation types

static void printtimestamp(void)
{
    struct tm tm;
    int ms;
    static char date[16];
    static char new_date[16];
#ifdef _WIN32
    SYSTEMTIME sysTime;
    time_t uct = time(NULL);
    tm = *localtime(&uct);
    GetLocalTime(&sysTime);
    ms = sysTime.wMilliseconds;
#else
    struct timeval tv;
    gettimeofday(&tv, NULL);
    localtime_r((time_t*)&tv.tv_sec, &tm);
    ms = tv.tv_usec/1000;
#endif
    strftime(new_date, sizeof(new_date), "%a %d %b %Y", &tm);
    if (strncmp(date, new_date, sizeof(new_date)))
    {
        printf("DATE: ---%s---\n", new_date); //display date only if it has changed
        strncpy(date, new_date, sizeof(date));
    }
    printf("%2d:%02d:%02d.%03d  ", tm.tm_hour, tm.tm_min, tm.tm_sec, ms);
}

static void print_usage(const char *arg0, int print_all)
{
    fprintf(stderr, "%s -E                  (Enumerate recommended registration domains)\n", arg0);
    fprintf(stderr, "%s -F                      (Enumerate recommended browsing domains)\n", arg0);
    fprintf(stderr, "%s -R <Name> <Type> <Domain> <Port> [<TXT>...] (Register a service)\n", arg0);
    fprintf(stderr, "%s -B        <Type> <Domain>        (Browse for services instances)\n", arg0);
    fprintf(stderr, "%s -L <Name> <Type> <Domain>           (Look up a service instance)\n", arg0);
    fprintf(stderr, "%s -P <Name> <Type> <Domain> <Port> <Host> <IP> [<TXT>...]  (Proxy)\n", arg0);
    fprintf(stderr, "%s -q <name> <rrtype> <rrclass> (Generic query for any record type)\n", arg0);
    fprintf(stderr, "%s -Z        <Type> <Domain>   (Output results in Zone File format)\n", arg0);
#if HAS_ADDRINFO_API
    fprintf(stderr, "%s -G     v4/v6/v4v6 <name>  (Get address information for hostname)\n", arg0);
#endif
    fprintf(stderr, "%s -V    (Get version of currently running daemon / system service)\n", arg0);

    if (print_all)  //Print all available options for dns-sd tool
    {
        fprintf(stderr, "%s -C <FQDN> <rrtype> <rrclass>   (Query; reconfirming each result)\n", arg0);
#if HAS_NAT_PMP_API
        fprintf(stderr, "%s -X udp/tcp/udptcp <IntPort> <ExtPort> <TTL>   (NAT Port Mapping)\n", arg0);
#endif
        fprintf(stderr, "%s -A                      (Test Adding/Updating/Deleting a record)\n", arg0);
        fprintf(stderr, "%s -U                                  (Test updating a TXT record)\n", arg0);
        fprintf(stderr, "%s -N                             (Test adding a large NULL record)\n", arg0);
        fprintf(stderr, "%s -T                            (Test creating a large TXT record)\n", arg0);
        fprintf(stderr, "%s -M      (Test creating a registration with multiple TXT records)\n", arg0);
        fprintf(stderr, "%s -I   (Test registering and then immediately updating TXT record)\n", arg0);
        fprintf(stderr, "%s -S                 (Test multiple operations on a shared socket)\n", arg0);
        fprintf(stderr, "%s -i <Interface> (Run dns-sd cmd on a specific interface (en0/en1)\n", arg0);
        fprintf(stderr, "%s -lo                  (Run dns-sd cmd using local only interface)\n", arg0);
        fprintf(stderr, "%s -p2p                          (Use kDNSServiceInterfaceIndexP2P)\n", arg0);
        fprintf(stderr, "%s -includep2p                (Set kDNSServiceFlagsIncludeP2P flag)\n", arg0);
        fprintf(stderr, "%s -includeAWDL              (Set kDNSServiceFlagsIncludeAWDL flag)\n", arg0);
        fprintf(stderr, "%s -tc            (Set kDNSServiceFlagsBackgroundTrafficClass flag)\n", arg0);
    }
}

#define DomainMsg(X) (((X) &kDNSServiceFlagsDefault) ? "(Default)" : \
                      ((X) &kDNSServiceFlagsAdd)     ? "Added"     : "Removed")

#define MAX_LABELS 128

static void DNSSD_API enum_reply(DNSServiceRef sdref, const DNSServiceFlags flags, uint32_t ifIndex,
                                 DNSServiceErrorType errorCode, const char *replyDomain, void *context)
{
    DNSServiceFlags partialflags = flags & ~(kDNSServiceFlagsMoreComing | kDNSServiceFlagsAdd | kDNSServiceFlagsDefault);
    int labels = 0, depth = 0, i, initial = 0;
    char text[64];
    const char *label[MAX_LABELS];

    (void)sdref;        // Unused
    (void)ifIndex;      // Unused
    (void)context;      // Unused
    EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode);

    // 1. Print the header
    if (num_printed++ == 0) printf("Timestamp     Recommended %s domain\n", operation == 'E' ? "Registration" : "Browsing");
    printtimestamp();
    if (errorCode)
        printf("Error code %d\n", errorCode);
    else if (!*replyDomain)
        printf("Error: No reply domain\n");
    else
    {
        printf("%-10s", DomainMsg(flags));
        printf("%-8s", (flags & kDNSServiceFlagsMoreComing) ? "(More)" : "");
        if (partialflags) printf("Flags: %4X  ", partialflags);
        else printf("             ");

        // 2. Count the labels
        while (replyDomain && *replyDomain && labels < MAX_LABELS)
        {
            label[labels++] = replyDomain;
            replyDomain = GetNextLabel(replyDomain, text);
        }

        // 3. Decide if we're going to clump the last two or three labels (e.g. "apple.com", or "nicta.com.au")
        if      (labels >= 3 && replyDomain - label[labels-1] <= 3 && label[labels-1] - label[labels-2] <= 4) initial = 3;
        else if (labels >= 2 && replyDomain - label[labels-1] <= 4) initial = 2;
        else initial = 1;
        labels -= initial;

        // 4. Print the initial one-, two- or three-label clump
        for (i=0; i<initial; i++)
        {
            GetNextLabel(label[labels+i], text);
            if (i>0) printf(".");
            printf("%s", text);
        }
        printf("\n");

        // 5. Print the remainder of the hierarchy
        for (depth=0; depth<labels; depth++)
        {
            printf("                                             ");
            for (i=0; i<=depth; i++) printf("- ");
            GetNextLabel(label[labels-1-depth], text);
            printf("> %s\n", text);
        }
    }

    if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout);
}

static int CopyLabels(char *dst, const char *lim, const char **srcp, int labels)
{
    const char *src = *srcp;
    while (*src != '.' || --labels > 0)
    {
        if (*src == '\\') *dst++ = *src++;  // Make sure "\." doesn't confuse us
        if (!*src || dst >= lim) return -1;
        *dst++ = *src++;
        if (!*src || dst >= lim) return -1;
    }
    *dst++ = 0;
    *srcp = src + 1;    // skip over final dot
    return 0;
}

static void DNSSD_API zonedata_resolve(DNSServiceRef sdref, const DNSServiceFlags flags, uint32_t ifIndex, DNSServiceErrorType errorCode,
                                       const char *fullname, const char *hosttarget, uint16_t opaqueport, uint16_t txtLen, const unsigned char *txt, void *context)
{
    union { uint16_t s; u_char b[2]; } port = { opaqueport };
    uint16_t PortAsNumber = ((uint16_t)port.b[0]) << 8 | port.b[1];

    const char *p = fullname;
    char n[kDNSServiceMaxDomainName];
    char t[kDNSServiceMaxDomainName];

    const unsigned char *max = txt + txtLen;

    (void)sdref;        // Unused
    (void)ifIndex;      // Unused
    (void)context;      // Unused

    //if (!(flags & kDNSServiceFlagsAdd)) return;
    if (errorCode) { printf("Error code %d\n", errorCode); return; }

    if (CopyLabels(n, n + kDNSServiceMaxDomainName, &p, 3)) return;     // Fetch name+type
    p = fullname;
    if (CopyLabels(t, t + kDNSServiceMaxDomainName, &p, 1)) return;     // Skip first label
    if (CopyLabels(t, t + kDNSServiceMaxDomainName, &p, 2)) return;     // Fetch next two labels (service type)

    if (num_printed++ == 0)
    {
        printf("\n");
        printf("; To direct clients to browse a different domain, substitute that domain in place of '@'\n");
        printf("%-47s PTR     %s\n", "lb._dns-sd._udp", "@");
        printf("\n");
        printf("; In the list of services below, the SRV records will typically reference dot-local Multicast DNS names.\n");
        printf("; When transferring this zone file data to your unicast DNS server, you'll need to replace those dot-local\n");
        printf("; names with the correct fully-qualified (unicast) domain name of the target host offering the service.\n");
    }

    printf("\n");
    printf("%-47s PTR     %s\n", t, n);
    printf("%-47s SRV     0 0 %d %s ; Replace with unicast FQDN of target host\n", n, PortAsNumber, hosttarget);
    printf("%-47s TXT    ", n);

    while (txt < max)
    {
        const unsigned char *const end = txt + 1 + txt[0];
        txt++;      // Skip over length byte
        printf(" \"");
        while (txt<end)
        {
            if (*txt == '\\' || *txt == '\"') printf("\\");
            printf("%c", *txt++);
        }
        printf("\"");
    }
    printf("\n");

    DNSServiceRefDeallocate(sdref);
    free(context);

    if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout);
}

static void DNSSD_API zonedata_browse(DNSServiceRef sdref, const DNSServiceFlags flags, uint32_t ifIndex, DNSServiceErrorType errorCode,
                                      const char *replyName, const char *replyType, const char *replyDomain, void *context)
{
    DNSServiceRef *newref;

    (void)sdref;        // Unused
    (void)context;      // Unused
    EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode);

    if (!(flags & kDNSServiceFlagsAdd)) return;
    if (errorCode) { printf("Error code %d\n", errorCode); return; }

    newref = malloc(sizeof(*newref));
    *newref = client;
    DNSServiceResolve(newref, kDNSServiceFlagsShareConnection, ifIndex, replyName, replyType, replyDomain, zonedata_resolve, newref);
}

static void DNSSD_API browse_reply(DNSServiceRef sdref, const DNSServiceFlags flags, uint32_t ifIndex, DNSServiceErrorType errorCode,
                                   const char *replyName, const char *replyType, const char *replyDomain, void *context)
{
    char *op = (flags & kDNSServiceFlagsAdd) ? "Add" : "Rmv";
    (void)sdref;        // Unused
    (void)context;      // Unused
    EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode);

    if (num_printed++ == 0) printf("Timestamp     A/R Flags if %-25s %-25s %s\n", "Domain", "Service Type", "Instance Name");
    printtimestamp();
    if (errorCode) printf("Error code %d\n", errorCode);
    else printf("%s%6X%3d %-25s %-25s %s\n", op, flags, ifIndex, replyDomain, replyType, replyName);
    if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout);

    // To test selective cancellation of operations of shared sockets,
    // cancel the current operation when we've got a multiple of five results
    //if (operation == 'S' && num_printed % 5 == 0) DNSServiceRefDeallocate(sdref);
}

static void ShowTXTRecord(uint16_t txtLen, const unsigned char *txtRecord)
{
    const unsigned char *ptr = txtRecord;
    const unsigned char *max = txtRecord + txtLen;
    while (ptr < max)
    {
        const unsigned char *const end = ptr + 1 + ptr[0];
        if (end > max) { printf("<< invalid data >>"); break; }
        if (++ptr < end) printf(" ");   // As long as string is non-empty, begin with a space
        while (ptr<end)
        {
            // We'd like the output to be shell-friendly, so that it can be copied and pasted unchanged into a "dns-sd -R" command.
            // However, this is trickier than it seems. Enclosing a string in double quotes doesn't necessarily make it
            // shell-safe, because shells still expand variables like $foo even when they appear inside quoted strings.
            // Enclosing a string in single quotes is better, but when using single quotes even backslash escapes are ignored,
            // meaning there's simply no way to represent a single quote (or apostrophe) inside a single-quoted string.
            // The only remaining solution is not to surround the string with quotes at all, but instead to use backslash
            // escapes to encode spaces and all other known shell metacharacters.
            // (If we've missed any known shell metacharacters, please let us know.)
            // In addition, non-printing ascii codes (0-31) are displayed as \xHH, using a two-digit hex value.
            // Because '\' is itself a shell metacharacter (the shell escape character), it has to be escaped as "\\" to survive
            // the round-trip to the shell and back. This means that a single '\' is represented here as EIGHT backslashes:
            // The C compiler eats half of them, resulting in four appearing in the output.
            // The shell parses those four as a pair of "\\" sequences, passing two backslashes to the "dns-sd -R" command.
            // The "dns-sd -R" command interprets this single "\\" pair as an escaped literal backslash. Sigh.
            if (strchr(" &;`'\"|*?~<>^()[]{}$", *ptr)) printf("\\");
            if      (*ptr == '\\') printf("\\\\\\\\");
            else if (*ptr >= ' ' ) printf("%c",        *ptr);
            else printf("\\\\x%02X", *ptr);
            ptr++;
        }
    }
}

static void DNSSD_API resolve_reply(DNSServiceRef sdref, const DNSServiceFlags flags, uint32_t ifIndex, DNSServiceErrorType errorCode,
                                    const char *fullname, const char *hosttarget, uint16_t opaqueport, uint16_t txtLen, const unsigned char *txtRecord, void *context)
{
    union { uint16_t s; u_char b[2]; } port = { opaqueport };
    uint16_t PortAsNumber = ((uint16_t)port.b[0]) << 8 | port.b[1];

    (void)sdref;        // Unused
    (void)ifIndex;      // Unused
    (void)context;      // Unused
    EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode);

    if (errorCode)
        printf("Error code %d\n", errorCode);
    else
    {
        printtimestamp();
        printf("%s can be reached at %s:%u (interface %d)", fullname, hosttarget, PortAsNumber, ifIndex);
        if (flags) printf(" Flags: %X", flags);
        // Don't show degenerate TXT records containing nothing but a single empty string
        if (txtLen > 1) { printf("\n"); ShowTXTRecord(txtLen, txtRecord); }
        printf("\n");
    }

    if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout);
}

static void myTimerCallBack(void)
{
    DNSServiceErrorType err = kDNSServiceErr_Unknown;

    switch (operation)
    {
    case 'A':
    {
        switch (addtest)
        {
        case 0: printf("Adding Test HINFO record\n");
            err = DNSServiceAddRecord(client, &record, 0, kDNSServiceType_HINFO, sizeof(myhinfoW), &myhinfoW[0], 0);
            addtest = 1;
            break;
        case 1: printf("Updating Test HINFO record\n");
            err = DNSServiceUpdateRecord(client, record, 0, sizeof(myhinfoX), &myhinfoX[0], 0);
            addtest = 2;
            break;
        case 2: printf("Removing Test HINFO record\n");
            err = DNSServiceRemoveRecord(client, record, 0);
            addtest = 0;
            break;
        }
    }
    break;

    case 'U':
    {
        if (updatetest[1] != 'Z') updatetest[1]++;
        else updatetest[1] = 'A';
        updatetest[0] = 3 - updatetest[0];
        updatetest[2] = updatetest[1];
        printtimestamp();
        printf("Updating Test TXT record to %c\n", updatetest[1]);
        err = DNSServiceUpdateRecord(client, NULL, 0, 1+updatetest[0], &updatetest[0], 0);
    }
    break;

    case 'N':
    {
        printf("Adding big NULL record\n");
        err = DNSServiceAddRecord(client, &record, 0, kDNSServiceType_NULL, sizeof(bigNULL), &bigNULL[0], 0);
        if (err) printf("Failed: %d\n", err);else printf("Succeeded\n");
        timeOut = LONG_TIME;
#if _DNS_SD_LIBDISPATCH
        if (timer_source)
            dispatch_source_set_timer(timer_source, dispatch_time(DISPATCH_TIME_NOW, (uint64_t)timeOut * NSEC_PER_SEC),
                                      (uint64_t)timeOut * NSEC_PER_SEC, 0);
#endif
    }
    break;
    }

    if (err != kDNSServiceErr_NoError)
    {
        fprintf(stderr, "DNSService add/update/remove failed %ld\n", (long int)err);
        stopNow = 1;
    }
}

static void DNSSD_API reg_reply(DNSServiceRef sdref, const DNSServiceFlags flags, DNSServiceErrorType errorCode,
                                const char *name, const char *regtype, const char *domain, void *context)
{
    (void)sdref;    // Unused
    (void)flags;    // Unused
    (void)context;  // Unused
    EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode);

    printtimestamp();
    printf("Got a reply for service %s.%s%s: ", name, regtype, domain);

    if (errorCode == kDNSServiceErr_NoError)
    {
        if (flags & kDNSServiceFlagsAdd) printf("Name now registered and active\n");
        else printf("Name registration removed\n");
        if (operation == 'A' || operation == 'U' || operation == 'N')
        {
            timeOut = 5;
#if _DNS_SD_LIBDISPATCH
            if (timer_source)
                dispatch_source_set_timer(timer_source, dispatch_time(DISPATCH_TIME_NOW, (uint64_t)timeOut * NSEC_PER_SEC),
                                          (uint64_t)timeOut * NSEC_PER_SEC, 0);
#endif
        }
    }
    else if (errorCode == kDNSServiceErr_NameConflict)
    {
        printf("Name in use, please choose another\n");
        exit(-1);
    }
    else
        printf("Error %d\n", errorCode);

    if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout);
}

// Output the wire-format domainname pointed to by rd
static int snprintd(char *p, int max, const unsigned char **rd)
{
    const char *const buf = p;
    const char *const end = p + max;
    while (**rd) { p += snprintf(p, end-p, "%.*s.", **rd, *rd+1); *rd += 1 + **rd; }
    *rd += 1;   // Advance over the final zero byte
    return(p-buf);
}

static void DNSSD_API qr_reply(DNSServiceRef sdref, const DNSServiceFlags flags, uint32_t ifIndex, DNSServiceErrorType errorCode,
                               const char *fullname, uint16_t rrtype, uint16_t rrclass, uint16_t rdlen, const void *rdata, uint32_t ttl, void *context)
{
    char *op = (flags & kDNSServiceFlagsAdd) ? "Add" : "Rmv";
    const unsigned char *rd  = rdata;
    const unsigned char *end = (const unsigned char *) rdata + rdlen;
    char rdb[1000] = "", *p = rdb;
    int unknowntype = 0;

    (void)sdref;    // Unused
    (void)flags;    // Unused
    (void)ifIndex;  // Unused
    (void)ttl;      // Unused
    (void)context;  // Unused
    EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode);

    if (num_printed++ == 0) printf("Timestamp     A/R Flags if %-30s%4s%4s Rdata\n", "Name", "T", "C");
    printtimestamp();

    if (!errorCode)
    {
        switch (rrtype)
        {
        case kDNSServiceType_A:
            snprintf(rdb, sizeof(rdb), "%d.%d.%d.%d", rd[0], rd[1], rd[2], rd[3]);
            break;

        case kDNSServiceType_NS:
        case kDNSServiceType_CNAME:
        case kDNSServiceType_PTR:
        case kDNSServiceType_DNAME:
            p += snprintd(p, sizeof(rdb), &rd);
            break;

        case kDNSServiceType_SOA:
            p += snprintd(p, rdb + sizeof(rdb) - p, &rd);           // mname
            p += snprintf(p, rdb + sizeof(rdb) - p, " ");
            p += snprintd(p, rdb + sizeof(rdb) - p, &rd);           // rname
            p += snprintf(p, rdb + sizeof(rdb) - p, " Ser %d Ref %d Ret %d Exp %d Min %d",
                          ntohl(((uint32_t*)rd)[0]), ntohl(((uint32_t*)rd)[1]), ntohl(((uint32_t*)rd)[2]), ntohl(((uint32_t*)rd)[3]), ntohl(((uint32_t*)rd)[4]));
            break;

        case kDNSServiceType_AAAA:
            snprintf(rdb, sizeof(rdb), "%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X",
                     rd[0x0], rd[0x1], rd[0x2], rd[0x3], rd[0x4], rd[0x5], rd[0x6], rd[0x7],
                     rd[0x8], rd[0x9], rd[0xA], rd[0xB], rd[0xC], rd[0xD], rd[0xE], rd[0xF]);
            break;

        case kDNSServiceType_SRV:
            p += snprintf(p, rdb + sizeof(rdb) - p, "%d %d %d ",        // priority, weight, port
                          ntohs(*(unsigned short*)rd), ntohs(*(unsigned short*)(rd+2)), ntohs(*(unsigned short*)(rd+4)));
            rd += 6;
            p += snprintd(p, rdb + sizeof(rdb) - p, &rd);               // target host
            break;

        default: snprintf(rdb, sizeof(rdb), "%d bytes%s", rdlen, rdlen ? ":" : ""); unknowntype = 1; break;
        }
    }

    printf("%s%6X%3d %-30s%4d%4d %s", op, flags, ifIndex, fullname, rrtype, rrclass, rdb);
    if (unknowntype) while (rd < end) printf(" %02X", *rd++);
    if (errorCode)
    {
        if (errorCode == kDNSServiceErr_NoSuchRecord) printf("No Such Record");
        else if (errorCode == kDNSServiceErr_Timeout)
        {
            printf("No Such Record\n");
            printf("Query Timed Out\n");
            exit(1);
        }
    }
    printf("\n");

    if (operation == 'C')
        if (flags & kDNSServiceFlagsAdd)
            DNSServiceReconfirmRecord(flags, ifIndex, fullname, rrtype, rrclass, rdlen, rdata);

    if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout);
}

#if HAS_NAT_PMP_API
static void DNSSD_API port_mapping_create_reply(DNSServiceRef sdref, DNSServiceFlags flags, uint32_t ifIndex, DNSServiceErrorType errorCode, uint32_t publicAddress, uint32_t protocol, uint16_t privatePort, uint16_t publicPort, uint32_t ttl, void *context)
{
    (void)sdref;       // Unused
    (void)flags;       // Unused
    (void)context;     // Unused
    EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode);

    if (num_printed++ == 0) printf("Timestamp     if   %-20s %-15s %-15s %-15s %-6s\n", "External Address", "Protocol", "Internal Port", "External Port", "TTL");
    printtimestamp();
    if (errorCode && errorCode != kDNSServiceErr_DoubleNAT) printf("Error code %d\n", errorCode);
    else
    {
        const unsigned char *digits = (const unsigned char *)&publicAddress;
        char addr[256];

        snprintf(addr, sizeof(addr), "%d.%d.%d.%d", digits[0], digits[1], digits[2], digits[3]);
        printf("%-4d %-20s %-15d %-15d %-15d %-6d%s\n", ifIndex, addr, protocol, ntohs(privatePort), ntohs(publicPort), ttl, errorCode == kDNSServiceErr_DoubleNAT ? " Double NAT" : "");
    }

    if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout);
}
#endif

#if HAS_ADDRINFO_API
static void DNSSD_API addrinfo_reply(DNSServiceRef sdref, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode, const char *hostname, const struct sockaddr *address, uint32_t ttl, void *context)
{
    char *op = (flags & kDNSServiceFlagsAdd) ? "Add" : "Rmv";
    char addr[256] = "";
    (void) sdref;
    (void) context;
    EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode);

    if (num_printed++ == 0) printf("Timestamp     A/R Flags if %-25s %-44s %s\n", "Hostname", "Address", "TTL");
    printtimestamp();

    if (address && address->sa_family == AF_INET)
    {
        const unsigned char *b = (const unsigned char *) &((struct sockaddr_in *)address)->sin_addr;
        snprintf(addr, sizeof(addr), "%d.%d.%d.%d", b[0], b[1], b[2], b[3]);
    }
    else if (address && address->sa_family == AF_INET6)
    {
        char if_name[IFNAMSIZ];     // Older Linux distributions don't define IF_NAMESIZE
        const struct sockaddr_in6 *s6 = (const struct sockaddr_in6 *)address;
        const unsigned char       *b  = (const unsigned char *      )&s6->sin6_addr;
        if (!if_indextoname(s6->sin6_scope_id, if_name))
            snprintf(if_name, sizeof(if_name), "<%d>", s6->sin6_scope_id);
        snprintf(addr, sizeof(addr), "%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X%%%s",
                 b[0x0], b[0x1], b[0x2], b[0x3], b[0x4], b[0x5], b[0x6], b[0x7],
                 b[0x8], b[0x9], b[0xA], b[0xB], b[0xC], b[0xD], b[0xE], b[0xF], if_name);
    }

    printf("%s%6X%3d %-25s %-44s %d", op, flags, interfaceIndex, hostname, addr, ttl);
    if (errorCode)
    {
        if (errorCode == kDNSServiceErr_NoSuchRecord) printf("   No Such Record");
        else printf("   Error code %d", errorCode);
    }
    printf("\n");

    if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout);
}
#endif

//*************************************************************************************************************
// The main test function

static void HandleEvents(void)
#if _DNS_SD_LIBDISPATCH
{
    main_queue = dispatch_get_main_queue();
    if (client) DNSServiceSetDispatchQueue(client, main_queue);
    if (client_pa) DNSServiceSetDispatchQueue(client_pa, main_queue);
    if (operation == 'A' || operation == 'U' || operation == 'N')
    {
        timer_source = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, main_queue);
        if (timer_source)
        {
            // Start the timer "timeout" seconds into the future and repeat it every "timeout" seconds
            dispatch_source_set_timer(timer_source, dispatch_time(DISPATCH_TIME_NOW, (uint64_t)timeOut * NSEC_PER_SEC),
                                      (uint64_t)timeOut * NSEC_PER_SEC, 0);
            dispatch_source_set_event_handler(timer_source, ^{myTimerCallBack();});
            dispatch_resume(timer_source);
        }
    }
    dispatch_main();
}
#else
{
    int dns_sd_fd  = client    ? DNSServiceRefSockFD(client   ) : -1;
    int dns_sd_fd2 = client_pa ? DNSServiceRefSockFD(client_pa) : -1;
    int nfds = dns_sd_fd + 1;
    fd_set readfds;
    struct timeval tv;
    int result;

    if (dns_sd_fd2 > dns_sd_fd) nfds = dns_sd_fd2 + 1;

    while (!stopNow)
    {
        // 1. Set up the fd_set as usual here.
        // This example client has no file descriptors of its own,
        // but a real application would call FD_SET to add them to the set here
        FD_ZERO(&readfds);

        // 2. Add the fd for our client(s) to the fd_set
        if (client   ) FD_SET(dns_sd_fd, &readfds);
        if (client_pa) FD_SET(dns_sd_fd2, &readfds);

        // 3. Set up the timeout.
        tv.tv_sec  = timeOut;
        tv.tv_usec = 0;

        result = select(nfds, &readfds, (fd_set*)NULL, (fd_set*)NULL, &tv);
        if (result > 0)
        {
            DNSServiceErrorType err = kDNSServiceErr_NoError;
            if      (client    && FD_ISSET(dns_sd_fd, &readfds)) err = DNSServiceProcessResult(client   );
            else if (client_pa && FD_ISSET(dns_sd_fd2, &readfds)) err = DNSServiceProcessResult(client_pa);
            if (err) { fprintf(stderr, "DNSServiceProcessResult returned %d\n", err); stopNow = 1; }
        }
        else if (result == 0)
            myTimerCallBack();
        else
        {
            printf("select() returned %d errno %d %s\n", result, errno, strerror(errno));
            if (errno != EINTR) stopNow = 1;
        }
    }
}
#endif

static int getfirstoption(int argc, char **argv, const char *optstr, int *pOptInd)
// Return the recognized option in optstr and the option index of the next arg.
#if NOT_HAVE_GETOPT
{
    int i;
    for (i=1; i < argc; i++)
    {
        if (argv[i][0] == '-' && &argv[i][1] &&
            NULL != strchr(optstr, argv[i][1]))
        {
            *pOptInd = i + 1;
            return argv[i][1];
        }
    }
    return -1;
}
#else
{
    int o = getopt(argc, (char *const *)argv, optstr);
    *pOptInd = optind;
    return o;
}
#endif

static void DNSSD_API MyRegisterRecordCallback(DNSServiceRef service, DNSRecordRef rec, const DNSServiceFlags flags,
                                               DNSServiceErrorType errorCode, void *context)
{
    char *name = (char *)context;

    (void)service;  // Unused
    (void)rec;      // Unused
    (void)flags;    // Unused
    EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode);

    printtimestamp();
    printf("Got a reply for record %s: ", name);

    switch (errorCode)
    {
    case kDNSServiceErr_NoError:      printf("Name now registered and active\n"); break;
    case kDNSServiceErr_NameConflict: printf("Name in use, please choose another\n"); exit(-1);
    default:                          printf("Error %d\n", errorCode); break;
    }
    if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout);
    // DNSServiceRemoveRecord(service, rec, 0); to test record removal

#if 0   // To test updating of individual records registered via DNSServiceRegisterRecord
    if (!errorCode)
    {
        int x = 0x11111111;
        printf("Updating\n");
        DNSServiceUpdateRecord(service, rec, 0, sizeof(x), &x, 0);
    }
#endif

    if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout);
}

static void getip(const char *const name, struct sockaddr_storage *result)
{
    struct addrinfo *addrs = NULL;
    int err = getaddrinfo(name, NULL, NULL, &addrs);
    if (err) fprintf(stderr, "getaddrinfo error %d for %s", err, name);
    else memcpy(result, addrs->ai_addr, SA_LEN(addrs->ai_addr));
    if (addrs) freeaddrinfo(addrs);
}

static DNSServiceErrorType RegisterProxyAddressRecord(DNSServiceRef sdref, const char *host, const char *ip, DNSServiceFlags flags)
{
    // Call getip() after the call DNSServiceCreateConnection().
    // On the Win32 platform, WinSock must be initialized for getip() to succeed.
    // Any DNSService* call will initialize WinSock for us, so we make sure
    // DNSServiceCreateConnection() is called before getip() is.
    struct sockaddr_storage hostaddr;
    getip(ip, &hostaddr);
    flags |= kDNSServiceFlagsUnique;
    if (hostaddr.ss_family == AF_INET)
        return(DNSServiceRegisterRecord(sdref, &record, flags, opinterface, host,
                                        kDNSServiceType_A,    kDNSServiceClass_IN,  4, &((struct sockaddr_in *)&hostaddr)->sin_addr,  240, MyRegisterRecordCallback, (void*)host));
    else if (hostaddr.ss_family == AF_INET6)
        return(DNSServiceRegisterRecord(sdref, &record, flags, opinterface, host,
                                        kDNSServiceType_AAAA, kDNSServiceClass_IN, 16, &((struct sockaddr_in6*)&hostaddr)->sin6_addr, 240, MyRegisterRecordCallback, (void*)host));
    else return(kDNSServiceErr_BadParam);
}

#define HexVal(X) ( ((X) >= '0' && (X) <= '9') ? ((X) - '0'     ) :  \
                    ((X) >= 'A' && (X) <= 'F') ? ((X) - 'A' + 10) :  \
                    ((X) >= 'a' && (X) <= 'f') ? ((X) - 'a' + 10) : 0)

#define HexPair(P) ((HexVal((P)[0]) << 4) | HexVal((P)[1]))

static DNSServiceErrorType RegisterService(DNSServiceRef *sdref,
                                           const char *nam, const char *typ, const char *dom, const char *host, const char *port, int argc, char **argv, DNSServiceFlags flags)
{
    uint16_t PortAsNumber = atoi(port);
    Opaque16 registerPort = { { PortAsNumber >> 8, PortAsNumber & 0xFF } };
    unsigned char txt[2048] = "";
    unsigned char *ptr = txt;
    int i;

    if (nam[0] == '.' && nam[1] == 0) nam = "";   // We allow '.' on the command line as a synonym for empty string
    if (dom[0] == '.' && dom[1] == 0) dom = "";   // We allow '.' on the command line as a synonym for empty string

    printf("Registering Service %s.%s%s%s", nam[0] ? nam : "<<Default>>", typ, dom[0] ? "." : "", dom);
    if (host && *host) printf(" host %s", host);
    printf(" port %s", port);

    if (argc)
    {
        for (i = 0; i < argc; i++)
        {
            const char *p = argv[i];
            *ptr = 0;
            while (*p && *ptr < 255 && ptr + 1 + *ptr < txt+sizeof(txt))
            {
                if      (p[0] != '\\' || p[1] == 0)                       { ptr[++*ptr] = *p;           p+=1; }
                else if (p[1] == 'x' && isxdigit(p[2]) && isxdigit(p[3])) { ptr[++*ptr] = HexPair(p+2); p+=4; }
                else                                                      { ptr[++*ptr] = p[1];         p+=2; }
            }
            ptr += 1 + *ptr;
        }
        printf(" TXT");
        ShowTXTRecord(ptr-txt, txt);
    }
    printf("\n");

    //flags |= kDNSServiceFlagsAllowRemoteQuery;
    //flags |= kDNSServiceFlagsNoAutoRename;

    return(DNSServiceRegister(sdref, flags, opinterface, nam, typ, dom, host, registerPort.NotAnInteger, (uint16_t) (ptr-txt), txt, reg_reply, NULL));
}

#define TypeBufferSize 80
static char *gettype(char *buffer, char *typ)
{
    if (!typ || !*typ || (typ[0] == '.' && typ[1] == 0)) typ = "_http._tcp";
    if (!strchr(typ, '.')) { snprintf(buffer, TypeBufferSize, "%s._tcp", typ); typ = buffer; }
    return(typ);
}

int main(int argc, char **argv)
{
    DNSServiceErrorType err;
    char buffer[TypeBufferSize], *typ, *dom;
    int opi;
    DNSServiceFlags flags = 0;

    // Extract the program name from argv[0], which by convention contains the path to this executable.
    // Note that this is just a voluntary convention, not enforced by the kernel --
    // the process calling exec() can pass bogus data in argv[0] if it chooses to.
    const char *a0 = strrchr(argv[0], kFilePathSep) + 1;
    if (a0 == (const char *)1) a0 = argv[0];

#if defined(_WIN32)
    HeapSetInformation(NULL, HeapEnableTerminationOnCorruption, NULL, 0);
#endif

#if TEST_NEW_CLIENTSTUB
    printf("Using embedded copy of dnssd_clientstub instead of system library\n");
    if (sizeof(argv) == 8) printf("Running in 64-bit mode\n");
#endif

    // Test code for TXTRecord functions
    //TXTRecordRef txtRecord;
    //TXTRecordCreate(&txtRecord, 0, NULL);
    //TXTRecordSetValue(&txtRecord, "aaa", 1, "b");
    //printf("%d\n", TXTRecordContainsKey(TXTRecordGetLength(&txtRecord), TXTRecordGetBytesPtr(&txtRecord), "Aaa"));

    if (argc > 1 && !strcmp(argv[1], "-lo"))
    {
        argc--;
        argv++;
        opinterface = kDNSServiceInterfaceIndexLocalOnly;
        printf("Using LocalOnly\n");
    }

    if (argc > 1 && (!strcmp(argv[1], "-p2p") || !strcmp(argv[1], "-P2P")))
    {
        argc--;
        argv++;
        opinterface = kDNSServiceInterfaceIndexP2P;
    }

    if (argc > 1 && !strcasecmp(argv[1], "-includep2p"))
    {
        argc--;
        argv++;
        flags |= kDNSServiceFlagsIncludeP2P;
        printf("Setting kDNSServiceFlagsIncludeP2P\n");
    }

    if (argc > 1 && !strcasecmp(argv[1], "-includeAWDL"))
    {
        argc--;
        argv++;
        flags |= kDNSServiceFlagsIncludeAWDL;
        printf("Setting kDNSServiceFlagsIncludeAWDL\n");
    }

    if (argc > 1 && !strcasecmp(argv[1], "-tc"))
    {
        argc--;
        argv++;
        flags |= kDNSServiceFlagsBackgroundTrafficClass;
        printf("Setting kDNSServiceFlagsBackgroundTrafficClass\n");
    }

    if (argc > 2 && !strcmp(argv[1], "-i"))
    {
        opinterface = if_nametoindex(argv[2]);
        if (!opinterface) opinterface = atoi(argv[2]);
        if (!opinterface) { fprintf(stderr, "Unknown interface %s\n", argv[2]); goto Fail; }
        argc -= 2;
        argv += 2;
    }

    if (argc < 2) goto Fail;        // Minimum command line is the command name and one argument
    operation = getfirstoption(argc, argv, "EFBZLlRPQqtCAUNTMISVHh"
                                #if HAS_NAT_PMP_API
                               "X"
                                #endif
                                #if HAS_ADDRINFO_API
                               "G"
                                #endif
                               , &opi);
    if (operation == -1) goto Fail;

    if (opinterface) printf("Using interface %d\n", opinterface);

    switch (operation)
    {
    case 'E':   printf("Looking for recommended registration domains:\n");
        err = DNSServiceEnumerateDomains(&client, kDNSServiceFlagsRegistrationDomains, opinterface, enum_reply, NULL);
        break;

    case 'F':   printf("Looking for recommended browsing domains:\n");
        err = DNSServiceEnumerateDomains(&client, kDNSServiceFlagsBrowseDomains, opinterface, enum_reply, NULL);
        //enum_reply(client, kDNSServiceFlagsAdd, 0, 0, "nicta.com.au.", NULL);
        //enum_reply(client, kDNSServiceFlagsAdd, 0, 0, "bonjour.nicta.com.au.", NULL);
        //enum_reply(client, kDNSServiceFlagsAdd, 0, 0, "ibm.com.", NULL);
        //enum_reply(client, kDNSServiceFlagsAdd, 0, 0, "dns-sd.ibm.com.", NULL);
        break;

    case 'B':   typ = (argc < opi+1) ? "" : argv[opi+0];
        dom = (argc < opi+2) ? "" : argv[opi+1];              // Missing domain argument is the same as empty string i.e. use system default(s)
        typ = gettype(buffer, typ);
        if (dom[0] == '.' && dom[1] == 0) dom[0] = 0;               // We allow '.' on the command line as a synonym for empty string
        printf("Browsing for %s%s%s\n", typ, dom[0] ? "." : "", dom);
        err = DNSServiceBrowse(&client, flags, opinterface, typ, dom, browse_reply, NULL);
        break;

    case 'Z':   typ = (argc < opi+1) ? "" : argv[opi+0];
        dom = (argc < opi+2) ? "" : argv[opi+1];              // Missing domain argument is the same as empty string i.e. use system default(s)
        typ = gettype(buffer, typ);
        if (dom[0] == '.' && dom[1] == 0) dom[0] = 0;               // We allow '.' on the command line as a synonym for empty string
        printf("Browsing for %s%s%s\n", typ, dom[0] ? "." : "", dom);
        err = DNSServiceCreateConnection(&client);
        sc1 = client;
        err = DNSServiceBrowse(&sc1, kDNSServiceFlagsShareConnection, opinterface, typ, dom, zonedata_browse, NULL);
        break;

    case 'l':
    case 'L':   {
        if (argc < opi+2) goto Fail;
        typ = (argc < opi+2) ? ""      : argv[opi+1];
        dom = (argc < opi+3) ? "local" : argv[opi+2];
        typ = gettype(buffer, typ);
        if (dom[0] == '.' && dom[1] == 0) dom = "local";               // We allow '.' on the command line as a synonym for "local"
        printf("Lookup %s.%s.%s\n", argv[opi+0], typ, dom);
        if (operation == 'l') flags |= kDNSServiceFlagsWakeOnResolve;
        err = DNSServiceResolve(&client, flags, opinterface, argv[opi+0], typ, dom, resolve_reply, NULL);
        break;
    }

    case 'R':   if (argc < opi+4) goto Fail;
        typ = (argc < opi+2) ? "" : argv[opi+1];
        dom = (argc < opi+3) ? "" : argv[opi+2];
        typ = gettype(buffer, typ);
        if (dom[0] == '.' && dom[1] == 0) dom[0] = 0;               // We allow '.' on the command line as a synonym for empty string
        err = RegisterService(&client, argv[opi+0], typ, dom, NULL, argv[opi+3], argc-(opi+4), argv+(opi+4), flags);
        break;

    case 'P':   if (argc < opi+6) goto Fail;
        err = DNSServiceCreateConnection(&client_pa);
        if (err) { fprintf(stderr, "DNSServiceCreateConnection returned %d\n", err); return(err); }
        err = RegisterProxyAddressRecord(client_pa, argv[opi+4], argv[opi+5], flags);
        if (err) break;
        err = RegisterService(&client, argv[opi+0], gettype(buffer, argv[opi+1]), argv[opi+2], argv[opi+4], argv[opi+3], argc-(opi+6), argv+(opi+6), flags);
        break;

    case 't':
    case 'q':
    case 'Q':
    case 'C':   {
        uint16_t rrtype, rrclass;
        flags |= kDNSServiceFlagsReturnIntermediates;
        if (operation == 'q') flags |= kDNSServiceFlagsSuppressUnusable;
        if (operation == 't') flags |= (kDNSServiceFlagsSuppressUnusable | kDNSServiceFlagsTimeout);
        if (argc < opi+1) goto Fail;
        rrtype = (argc <= opi+1) ? kDNSServiceType_A  : GetRRType(argv[opi+1]);
        rrclass = (argc <= opi+2) ? kDNSServiceClass_IN : atoi(argv[opi+2]);
        if (rrtype == kDNSServiceType_TXT || rrtype == kDNSServiceType_PTR) flags |= kDNSServiceFlagsLongLivedQuery;
        err = DNSServiceQueryRecord(&client, flags, opinterface, argv[opi+0], rrtype, rrclass, qr_reply, NULL);
        break;
    }

    case 'A':
    case 'U':
    case 'N':   {
        Opaque16 registerPort = { { 0x12, 0x34 } };
        static const char TXT[] = "\xC" "First String" "\xD" "Second String" "\xC" "Third String";
        printf("Registering Service Test._testupdate._tcp.local.\n");
        err = DNSServiceRegister(&client, 0, opinterface, "Test", "_testupdate._tcp.", "", NULL, registerPort.NotAnInteger, sizeof(TXT)-1, TXT, reg_reply, NULL);
        break;
    }

    case 'T':   {
        Opaque16 registerPort = { { 0x23, 0x45 } };
        char TXT[1024];
        unsigned int i;
        for (i=0; i<sizeof(TXT); i++)
            if ((i & 0x1F) == 0) TXT[i] = 0x1F;else TXT[i] = 'A' + (i >> 5);
        printf("Registering Service Test._testlargetxt._tcp.local.\n");
        err = DNSServiceRegister(&client, 0, opinterface, "Test", "_testlargetxt._tcp.", "", NULL, registerPort.NotAnInteger, sizeof(TXT), TXT, reg_reply, NULL);
        break;
    }

    case 'M':   {
        pid_t pid = getpid();
        Opaque16 registerPort = { { pid >> 8, pid & 0xFF } };
        static const char TXT1[] = "\xC" "First String"  "\xD" "Second String" "\xC" "Third String";
        static const char TXT2[] = "\xD" "Fourth String" "\xC" "Fifth String"  "\xC" "Sixth String";
        printf("Registering Service Test._testdualtxt._tcp.local.\n");
        err = DNSServiceRegister(&client, flags, opinterface, "Test", "_testdualtxt._tcp.", "", NULL, registerPort.NotAnInteger, sizeof(TXT1)-1, TXT1, reg_reply, NULL);
        if (!err) err = DNSServiceAddRecord(client, &record, flags, kDNSServiceType_TXT, sizeof(TXT2)-1, TXT2, 0);
        break;
    }

    case 'I':   {
        pid_t pid = getpid();
        Opaque16 registerPort = { { pid >> 8, pid & 0xFF } };
        static const char TXT[] = "\x09" "Test Data";
        printf("Registering Service Test._testtxt._tcp.local.\n");
        err = DNSServiceRegister(&client, 0, opinterface, "Test", "_testtxt._tcp.", "", NULL, registerPort.NotAnInteger, 0, NULL, reg_reply, NULL);
        if (!err) err = DNSServiceUpdateRecord(client, NULL, 0, sizeof(TXT)-1, TXT, 0);
        break;
    }

#if HAS_NAT_PMP_API
    case 'X':   {
        if (argc == opi)                // If no arguments, just fetch IP address
            err = DNSServiceNATPortMappingCreate(&client, 0, 0, 0, 0, 0, 0, port_mapping_create_reply, NULL);
        else if (argc >= opi+2 && atoi(argv[opi+0]) == 0)
        {
            DNSServiceProtocol prot  = GetProtocol(argv[opi+0]);                                    // Must specify TCP or UDP
            uint16_t IntPortAsNumber = atoi(argv[opi+1]);                                       // Must specify internal port
            uint16_t ExtPortAsNumber = (argc < opi+3) ? 0 : atoi(argv[opi+2]);              // Optional desired external port
            uint32_t ttl             = (argc < opi+4) ? 0 : atoi(argv[opi+3]);              // Optional desired lease lifetime
            Opaque16 intp = { { IntPortAsNumber >> 8, IntPortAsNumber & 0xFF } };
            Opaque16 extp = { { ExtPortAsNumber >> 8, ExtPortAsNumber & 0xFF } };
            err = DNSServiceNATPortMappingCreate(&client, 0, 0, prot, intp.NotAnInteger, extp.NotAnInteger, ttl, port_mapping_create_reply, NULL);
        }
        else goto Fail;
        break;
    }
#endif

#if HAS_ADDRINFO_API
    case 'G':   {
        flags |= kDNSServiceFlagsReturnIntermediates;
        if (argc != opi+2) goto Fail;
        else err = DNSServiceGetAddrInfo(&client, flags, opinterface, GetProtocol(argv[opi+0]), argv[opi+1], addrinfo_reply, NULL);
        break;
    }
#endif

    case 'S':   {
        Opaque16 registerPort = { { 0x23, 0x45 } };                 // 9029 decimal
        unsigned char txtrec[16] = "\xF" "/path=test.html";
        DNSRecordRef rec;
        unsigned char nulrec[4] = "1234";

        err = DNSServiceCreateConnection(&client);
        if (err) { fprintf(stderr, "DNSServiceCreateConnection failed %ld\n", (long int)err); return (-1); }

        sc1 = client;
        err = DNSServiceBrowse(&sc1, kDNSServiceFlagsShareConnection, opinterface, "_http._tcp", "", browse_reply, NULL);
        if (err) { fprintf(stderr, "DNSServiceBrowse _http._tcp failed %ld\n", (long int)err); return (-1); }

        sc2 = client;
        err = DNSServiceBrowse(&sc2, kDNSServiceFlagsShareConnection, opinterface, "_ftp._tcp", "", browse_reply, NULL);
        if (err) { fprintf(stderr, "DNSServiceBrowse _ftp._tcp failed %ld\n", (long int)err); return (-1); }

        sc3 = client;
        err = DNSServiceRegister(&sc3, kDNSServiceFlagsShareConnection, opinterface, "kDNSServiceFlagsShareConnection",
                                 "_http._tcp", "local", NULL, registerPort.NotAnInteger, 0, NULL, reg_reply, NULL);
        if (err) { fprintf(stderr, "SharedConnection DNSServiceRegister failed %ld\n", (long int)err); return (-1); }

        err = DNSServiceUpdateRecord(sc3, NULL, 0, sizeof(txtrec), txtrec, 0);
        if (err) { fprintf(stderr, "SharedConnection DNSServiceUpdateRecord failed %ld\n", (long int)err); return (-1); }

        err = DNSServiceAddRecord(sc3, &rec, 0, kDNSServiceType_NULL, sizeof(nulrec), nulrec, 0);
        if (err) { fprintf(stderr, "SharedConnection DNSServiceAddRecord failed %ld\n", (long int)err); return (-1); }

        err = DNSServiceRemoveRecord(sc3, rec, 0);
        if (err) { fprintf(stderr, "SharedConnection DNSServiceRemoveRecord failed %ld\n", (long int)err); return (-1); }

        break;
    }

    case 'V':   {
        uint32_t v;
        uint32_t size = sizeof(v);
        err = DNSServiceGetProperty(kDNSServiceProperty_DaemonVersion, &v, &size);
        if (err) fprintf(stderr, "DNSServiceGetProperty failed %ld\n", (long int)err);
        else printf("Currently running daemon (system service) is version %d.%d\n", v / 10000, v / 100 % 100);
        exit(0);
    }

    case 'H': goto Fail;

    default: goto Fail;
    }

    if (!client || err != kDNSServiceErr_NoError) { fprintf(stderr, "DNSService call failed %ld\n", (long int)err); return (-1); }
    printtimestamp();
    printf("...STARTING...\n");
    HandleEvents();

    // Be sure to deallocate the DNSServiceRef when you're finished
    if (client   ) DNSServiceRefDeallocate(client   );
    if (client_pa) DNSServiceRefDeallocate(client_pa);
    return 0;

Fail:
    if (operation == 'H') print_usage(a0,1);
    else print_usage(a0,0);
    return 0;

}

// Note: The C preprocessor stringify operator ('#') makes a string from its argument, without macro expansion
// e.g. If "version" is #define'd to be "4", then STRINGIFY_AWE(version) will return the string "version", not "4"
// To expand "version" to its value before making the string, use STRINGIFY(version) instead
#define STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s) # s
#define STRINGIFY(s) STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s)

// NOT static -- otherwise the compiler may optimize it out
// The "@(#) " pattern is a special prefix the "what" command looks for
const char VersionString_SCCS[] = "@(#) dns-sd " STRINGIFY(mDNSResponderVersion) " (" __DATE__ " " __TIME__ ")";

#if _BUILDING_XCODE_PROJECT_
// If the process crashes, then this string will be magically included in the automatically-generated crash log
const char *__crashreporter_info__ = VersionString_SCCS + 5;
asm (".desc ___crashreporter_info__, 0x10");
#endif