mDNSResponder-164.tar.gz

[apple/mdnsresponder.git] / Clients / dns-sd.c

/* -*- Mode: C; tab-width: 4 -*-
 *
 * Copyright (c) 2002-2006 Apple Computer, 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.
 *
 * Formatting notes:
 * This code follows the "Whitesmiths style" C indentation rules. Plenty of discussion
 * on C indentation can be found on the web, such as <http://www.kafejo.com/komp/1tbs.htm>,
 * but for the sake of brevity here I will say just this: Curly braces are not syntactially
 * part of an "if" statement; they are the beginning and ending markers of a compound statement;
 * therefore common sense dictates that if they are part of a compound statement then they
 * should be indented to the same level as everything else in that compound statement.
 * Indenting curly braces at the same level as the "if" implies that curly braces are
 * part of the "if", which is false. (This is as misleading as people who write "char* x,y;"
 * thinking that variables x and y are both of type "char*" -- and anyone who doesn't
 * understand why variable y is not of type "char*" just proves the point that poor code
 * layout leads people to unfortunate misunderstandings about how the C language really works.)

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

#include <ctype.h>
#include <stdio.h>                      // For stdout, stderr
#include <stdlib.h>                     // For exit()
#include <string.h>                     // For strlen(), strcpy(), bzero()
#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 <process.h>
        typedef int        pid_t;
        #define getpid     _getpid
        #define strcasecmp _stricmp
        #define snprintf   _snprintf
        static const char kFilePathSep = '\\';
#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 = '/';
#endif

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

#include "dns_sd.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[8200];

// 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;

//*************************************************************************************************************
// 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, "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;
#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
        printf("%2d:%02d:%02d.%03d  ", tm.tm_hour, tm.tm_min, tm.tm_sec, ms);
        }

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

static const char *GetNextLabel(const char *cstr, char label[64])
        {
        char *ptr = label;
        while (*cstr && *cstr != '.')                                                           // While we have characters in the label...
                {
                char c = *cstr++;
                if (c == '\\')
                        {
                        c = *cstr++;
                        if (isdigit(cstr[-1]) && isdigit(cstr[0]) && isdigit(cstr[1]))
                                {
                                int v0 = cstr[-1] - '0';                                                // then interpret as three-digit decimal
                                int v1 = cstr[ 0] - '0';
                                int v2 = cstr[ 1] - '0';
                                int val = v0 * 100 + v1 * 10 + v2;
                                if (val <= 255) { c = (char)val; cstr += 2; }   // If valid three-digit decimal value, use it
                                }
                        }
                *ptr++ = c;
                if (ptr >= label+64) return(NULL);
                }
        if (*cstr) cstr++;                                                                                      // Skip over the trailing dot (if present)
        *ptr++ = 0;
        return(cstr);
        }

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[128];
        
        (void)sdref;        // Unused
        (void)ifIndex;      // Unused
        (void)context;      // Unused

        // 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)
                        {
                        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 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
        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

        printtimestamp();
        if (errorCode) printf("Error code %d\n", errorCode);
        else
                {
                printf("%s can be reached at %s:%u", fullname, hosttarget, PortAsNumber);
                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];
                        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;
                        }
                        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

        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;
                }
        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

        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                                          printf("Error code %d", errorCode);
                }
        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)context;     // Unused
        (void)flags;       // Unused
        
        if (num_printed++ == 0) printf("Timestamp     if   %-20s %-15s %-15s %-15s %s\n", "External Address", "Protocol", "Internal Port", "External Port", "TTL");
        printtimestamp();
        if (errorCode) 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 %d\n", ifIndex, addr, protocol, ntohs(privatePort), ntohs(publicPort), ttl);
                }
        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;
        
        if (num_printed++ == 0) printf("Timestamp     A/R Flags if %-25s %-40s %s\n", "Hostname", "Address", "TTL");
        printtimestamp();

        if (address && address->sa_family == AF_INET)
                {
                const unsigned char *digits = (const unsigned char *) &((struct sockaddr_in *)address)->sin_addr;
                snprintf(addr, sizeof(addr), "%d.%d.%d.%d", digits[0], digits[1], digits[2], digits[3]);
                }
        else if (address && address->sa_family == AF_INET6)
                {
                const unsigned char *digits = (const unsigned char *) &((struct sockaddr_in6 *)address)->sin6_addr;
                snprintf(addr, sizeof(addr), "%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X",
                                digits[0x0], digits[0x1], digits[0x2], digits[0x3], digits[0x4], digits[0x5], digits[0x6], digits[0x7],
                                digits[0x8], digits[0x9], digits[0xA], digits[0xB], digits[0xC], digits[0xD], digits[0xE], digits[0xF]);
                }

        printf("%s%6X%3d %-25s %-40s %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)
        {
        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;
                        }
                }
        }

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 operation = getopt(argc, (char *const *)argv, optstr);
        *pOptInd = optind;
        return operation;
        }
#endif

static void DNSSD_API MyRegisterRecordCallback(DNSServiceRef service, DNSRecordRef record, const DNSServiceFlags flags,
    DNSServiceErrorType errorCode, void *context)
        {
        char *name = (char *)context;
        
        (void)service;  // Unused
        (void)record;   // Unused
        (void)flags;    // Unused
        
        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, record, 0); to test record removal
        }

static unsigned long getip(const char *const name)
        {
        unsigned long ip = 0;
        struct addrinfo hints;
        struct addrinfo *addrs = NULL;

        memset(&hints, 0, sizeof(hints));
        hints.ai_family = AF_INET;
        
        if (getaddrinfo(name, NULL, &hints, &addrs) == 0)
                {
                ip = ((struct sockaddr_in*) addrs->ai_addr)->sin_addr.s_addr;
                }

        if (addrs)
                {
                freeaddrinfo(addrs);
                }

        return(ip);
        }

static DNSServiceErrorType RegisterProxyAddressRecord(DNSServiceRef sdref, const char *host, const char *ip)
        {
        // 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.
        unsigned long addr = getip(ip);
        return(DNSServiceRegisterRecord(sdref, &record, kDNSServiceFlagsUnique, opinterface, host,
                kDNSServiceType_A, kDNSServiceClass_IN, sizeof(addr), &addr, 240, MyRegisterRecordCallback, (void*)host));
        // Note, should probably add support for creating proxy AAAA records too, one day
        }

#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 = 0;
        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 optind;

        // 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 (sizeof(argv) == 8) printf("Running in 64-bit mode\n");

        // 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 > 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, "EFBLRPQCAUNTMISV"
                                                                #if HAS_NAT_PMP_API
                                                                        "X"
                                                                #endif
                                                                #if HAS_ADDRINFO_API
                                                                        "G"
                                                                #endif
                                                                , &optind);
        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 < optind+1) ? "" : argv[optind+0];
                                        dom = (argc < optind+2) ? "" : argv[optind+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, 0, opinterface, typ, dom, browse_reply, NULL);
                                        break;

                case 'L':       if (argc < optind+2) goto Fail;
                                        typ = (argc < optind+2) ? ""      : argv[optind+1];
                                        dom = (argc < optind+3) ? "local" : argv[optind+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[optind+0], typ, dom);
                                        err = DNSServiceResolve(&client, 0, opinterface, argv[optind+0], typ, dom, (DNSServiceResolveReply)resolve_reply, NULL);
                                        break;

                case 'R':       if (argc < optind+4) goto Fail;
                                        typ = (argc < optind+2) ? "" : argv[optind+1];
                                        dom = (argc < optind+3) ? "" : argv[optind+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[optind+0], typ, dom, NULL, argv[optind+3], argc-(optind+4), argv+(optind+4));
                                        break;

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

                case 'Q':
                case 'C':       {
                                        uint16_t rrtype, rrclass;
                                        DNSServiceFlags flags = kDNSServiceFlagsReturnIntermediates;
                                        if (argc < optind+1) goto Fail;
                                        rrtype = (argc <= optind+1) ? kDNSServiceType_A  : GetRRType(argv[optind+1]);
                                        rrclass = (argc <= optind+2) ? kDNSServiceClass_IN : atoi(argv[optind+2]);
                                        if (rrtype == kDNSServiceType_TXT || rrtype == kDNSServiceType_PTR) flags |= kDNSServiceFlagsLongLivedQuery;
                                        err = DNSServiceQueryRecord(&client, flags, opinterface, argv[optind+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, 0, opinterface, "Test", "_testdualtxt._tcp.", "", NULL, registerPort.NotAnInteger, sizeof(TXT1)-1, TXT1, reg_reply, NULL);
                                        if (!err) err = DNSServiceAddRecord(client, &record, 0, 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 == optind)     // If no arguments, just fetch IP address
                                                err = DNSServiceNATPortMappingCreate(&client, 0, 0, 0, 0, 0, 0, port_mapping_create_reply, NULL);
                                        else if (argc >= optind+2 && atoi(argv[optind+0]) == 0)
                                                {
                                                DNSServiceProtocol prot  = GetProtocol(argv[optind+0]);                                         // Must specify TCP or UDP
                                                uint16_t IntPortAsNumber = atoi(argv[optind+1]);                                                        // Must specify internal port
                                                uint16_t ExtPortAsNumber = (argc < optind+3) ? 0 : atoi(argv[optind+2]);        // Optional desired external port
                                                uint32_t ttl             = (argc < optind+4) ? 0 : atoi(argv[optind+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':   {
                                        if (argc != optind+2) goto Fail;
                                        else err = DNSServiceGetAddrInfo(&client, kDNSServiceFlagsReturnIntermediates, opinterface, GetProtocol(argv[optind+0]), argv[optind+1], addrinfo_reply, NULL);
                                        break;
                            }
#endif

                case 'S':       {
                                        Opaque16 registerPort = { { 0x23, 0x45 } };
                                        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); }

                                        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);
                                }

                default: goto Fail;
                }

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

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

Fail:
        fprintf(stderr, "%s -E                  (Enumerate recommended registration domains)\n", a0);
        fprintf(stderr, "%s -F                      (Enumerate recommended browsing domains)\n", a0);
        fprintf(stderr, "%s -B        <Type> <Domain>        (Browse for services instances)\n", a0);
        fprintf(stderr, "%s -L <Name> <Type> <Domain>           (Look up a service instance)\n", a0);
        fprintf(stderr, "%s -R <Name> <Type> <Domain> <Port> [<TXT>...] (Register a service)\n", a0);
        fprintf(stderr, "%s -P <Name> <Type> <Domain> <Port> <Host> <IP> [<TXT>...]  (Proxy)\n", a0);
        fprintf(stderr, "%s -Q <FQDN> <rrtype> <rrclass> (Generic query for any record type)\n", a0);
        fprintf(stderr, "%s -C <FQDN> <rrtype> <rrclass>   (Query; reconfirming each result)\n", a0);
#if HAS_NAT_PMP_API
        fprintf(stderr, "%s -X udp/tcp/udptcp <IntPort> <ExtPort> <TTL>   (NAT Port Mapping)\n", a0);
#endif
#if HAS_ADDRINFO_API
        fprintf(stderr, "%s -G v4/v6/v4v6 <Hostname>  (Get address information for hostname)\n", a0);
#endif
        fprintf(stderr, "%s -A                      (Test Adding/Updating/Deleting a record)\n", a0);
        fprintf(stderr, "%s -U                                  (Test updating a TXT record)\n", a0);
        fprintf(stderr, "%s -N                             (Test adding a large NULL record)\n", a0);
        fprintf(stderr, "%s -T                            (Test creating a large TXT record)\n", a0);
        fprintf(stderr, "%s -M      (Test creating a registration with multiple TXT records)\n", a0);
        fprintf(stderr, "%s -I   (Test registering and then immediately updating TXT record)\n", a0);
        fprintf(stderr, "%s -S                 (Test multiple operations on a shared socket)\n", a0);
        fprintf(stderr, "%s -V    (Get version of currently running daemon / system service)\n", a0);
        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 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");