/* -*- 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.
 *
 * 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

// 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;
        }

#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"

#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

// 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")

#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

    // 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 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 (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;
            }
            break;
        }

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



// 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 %-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" : "");
        }
    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 %-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)
    {
    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 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
    
    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
    }

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]))

