1 | /* -*- Mode: C; tab-width: 4 -*- |
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2 | * |
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3 | * Copyright (c) 2002-2004 Apple Computer, Inc. All rights reserved. |
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4 | * |
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5 | * Licensed under the Apache License, Version 2.0 (the "License"); |
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6 | * you may not use this file except in compliance with the License. |
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7 | * You may obtain a copy of the License at |
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8 | * |
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9 | * http://www.apache.org/licenses/LICENSE-2.0 |
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10 | * |
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11 | * Unless required by applicable law or agreed to in writing, software |
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12 | * distributed under the License is distributed on an "AS IS" BASIS, |
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13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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14 | * See the License for the specific language governing permissions and |
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15 | * limitations under the License. |
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16 | */ |
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17 | |
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18 | #include <assert.h> |
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19 | #include <signal.h> |
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20 | #include <stdio.h> |
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21 | #include <string.h> |
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22 | #include <unistd.h> |
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23 | #include <stdlib.h> |
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24 | |
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25 | #include "mDNSEmbeddedAPI.h" // Defines the interface to the mDNS core code |
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26 | #include "mDNSPosix.h" // Defines the specific types needed to run mDNS on this platform |
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27 | #include "ExampleClientApp.h" |
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28 | |
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29 | // Globals |
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30 | static mDNS mDNSStorage; // mDNS core uses this to store its globals |
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31 | static mDNS_PlatformSupport PlatformStorage; // Stores this platform's globals |
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32 | #define RR_CACHE_SIZE 500 |
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33 | static CacheEntity gRRCache[RR_CACHE_SIZE]; |
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34 | |
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35 | mDNSexport const char ProgramName[] = "mDNSClientPosix"; |
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36 | |
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37 | static const char *gProgramName = ProgramName; |
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38 | |
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39 | static void BrowseCallback(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) |
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40 | // A callback from the core mDNS code that indicates that we've received a |
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41 | // response to our query. Note that this code runs on the main thread |
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42 | // (in fact, there is only one thread!), so we can safely printf the results. |
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43 | { |
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44 | domainlabel name; |
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45 | domainname type; |
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46 | domainname domain; |
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47 | char nameC [MAX_DOMAIN_LABEL+1]; // Unescaped name: up to 63 bytes plus C-string terminating NULL. |
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48 | char typeC [MAX_ESCAPED_DOMAIN_NAME]; |
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49 | char domainC[MAX_ESCAPED_DOMAIN_NAME]; |
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50 | const char *state; |
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51 | |
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52 | (void)m; // Unused |
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53 | (void)question; // Unused |
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54 | |
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55 | assert(answer->rrtype == kDNSType_PTR); |
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56 | |
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57 | DeconstructServiceName(&answer->rdata->u.name, &name, &type, &domain); |
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58 | |
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59 | ConvertDomainLabelToCString_unescaped(&name, nameC); |
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60 | ConvertDomainNameToCString(&type, typeC); |
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61 | ConvertDomainNameToCString(&domain, domainC); |
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62 | |
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63 | // If the TTL has hit 0, the service is no longer available. |
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64 | if (!AddRecord) { |
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65 | state = "Lost "; |
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66 | } else { |
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67 | state = "Found"; |
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68 | } |
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69 | fprintf(stderr, "*** %s name = '%s', type = '%s', domain = '%s'\n", state, nameC, typeC, domainC); |
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70 | } |
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71 | |
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72 | static mDNSBool CheckThatServiceTypeIsUsable(const char *serviceType, mDNSBool printExplanation) |
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73 | // Checks that serviceType is a reasonable service type |
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74 | // label and, if it isn't and printExplanation is true, prints |
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75 | // an explanation of why not. |
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76 | { |
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77 | mDNSBool result; |
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78 | |
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79 | result = mDNStrue; |
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80 | if (result && strlen(serviceType) > 63) { |
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81 | if (printExplanation) { |
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82 | fprintf(stderr, |
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83 | "%s: Service type specified by -t is too long (must be 63 characters or less)\n", |
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84 | gProgramName); |
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85 | } |
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86 | result = mDNSfalse; |
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87 | } |
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88 | if (result && serviceType[0] == 0) { |
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89 | if (printExplanation) { |
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90 | fprintf(stderr, |
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91 | "%s: Service type specified by -t can't be empty\n", |
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92 | gProgramName); |
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93 | } |
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94 | result = mDNSfalse; |
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95 | } |
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96 | return result; |
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97 | } |
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98 | |
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99 | static const char kDefaultServiceType[] = "_afpovertcp._tcp"; |
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100 | static const char kDefaultDomain[] = "local."; |
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101 | |
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102 | static void PrintUsage() |
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103 | { |
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104 | fprintf(stderr, |
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105 | "Usage: %s [-v level] [-t type] [-d domain]\n", |
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106 | gProgramName); |
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107 | fprintf(stderr, " -v verbose mode, level is a number from 0 to 2\n"); |
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108 | fprintf(stderr, " 0 = no debugging info (default)\n"); |
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109 | fprintf(stderr, " 1 = standard debugging info\n"); |
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110 | fprintf(stderr, " 2 = intense debugging info\n"); |
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111 | fprintf(stderr, " -t uses 'type' as the service type (default is '%s')\n", kDefaultServiceType); |
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112 | fprintf(stderr, " -d uses 'domain' as the domain to browse (default is '%s')\n", kDefaultDomain); |
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113 | } |
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114 | |
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115 | static const char *gServiceType = kDefaultServiceType; |
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116 | static const char *gServiceDomain = kDefaultDomain; |
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117 | |
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118 | static void ParseArguments(int argc, char **argv) |
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119 | // Parses our command line arguments into the global variables |
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120 | // listed above. |
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121 | { |
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122 | int ch; |
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123 | |
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124 | // Set gProgramName to the last path component of argv[0] |
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125 | |
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126 | gProgramName = strrchr(argv[0], '/'); |
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127 | if (gProgramName == NULL) { |
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128 | gProgramName = argv[0]; |
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129 | } else { |
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130 | gProgramName += 1; |
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131 | } |
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132 | |
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133 | // Parse command line options using getopt. |
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134 | |
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135 | do { |
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136 | ch = getopt(argc, argv, "v:t:d:"); |
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137 | if (ch != -1) { |
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138 | switch (ch) { |
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139 | case 'v': |
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140 | gMDNSPlatformPosixVerboseLevel = atoi(optarg); |
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141 | if (gMDNSPlatformPosixVerboseLevel < 0 || gMDNSPlatformPosixVerboseLevel > 2) { |
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142 | fprintf(stderr, |
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143 | "%s: Verbose mode must be in the range 0..2\n", |
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144 | gProgramName); |
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145 | exit(1); |
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146 | } |
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147 | break; |
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148 | case 't': |
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149 | gServiceType = optarg; |
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150 | if ( !CheckThatServiceTypeIsUsable(gServiceType, mDNStrue) ) { |
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151 | exit(1); |
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152 | } |
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153 | break; |
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154 | case 'd': |
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155 | gServiceDomain = optarg; |
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156 | break; |
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157 | case '?': |
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158 | default: |
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159 | PrintUsage(); |
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160 | exit(1); |
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161 | break; |
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162 | } |
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163 | } |
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164 | } while (ch != -1); |
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165 | |
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166 | // Check for any left over command line arguments. |
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167 | |
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168 | if (optind != argc) { |
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169 | fprintf(stderr, "%s: Unexpected argument '%s'\n", gProgramName, argv[optind]); |
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170 | exit(1); |
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171 | } |
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172 | } |
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173 | |
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174 | int main(int argc, char **argv) |
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175 | // The program's main entry point. The program does a trivial |
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176 | // mDNS query, looking for all AFP servers in the local domain. |
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177 | { |
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178 | int result; |
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179 | mStatus status; |
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180 | DNSQuestion question; |
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181 | domainname type; |
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182 | domainname domain; |
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183 | |
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184 | // Parse our command line arguments. This won't come back if there's an error. |
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185 | ParseArguments(argc, argv); |
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186 | |
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187 | // Initialise the mDNS core. |
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188 | status = mDNS_Init(&mDNSStorage, &PlatformStorage, |
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189 | gRRCache, RR_CACHE_SIZE, |
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190 | mDNS_Init_DontAdvertiseLocalAddresses, |
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191 | mDNS_Init_NoInitCallback, mDNS_Init_NoInitCallbackContext); |
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192 | if (status == mStatus_NoError) { |
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193 | |
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194 | // Construct and start the query. |
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195 | |
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196 | MakeDomainNameFromDNSNameString(&type, gServiceType); |
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197 | MakeDomainNameFromDNSNameString(&domain, gServiceDomain); |
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198 | |
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199 | status = mDNS_StartBrowse(&mDNSStorage, &question, &type, &domain, mDNSNULL, mDNSInterface_Any, 0, mDNSfalse, mDNSfalse, BrowseCallback, NULL); |
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200 | |
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201 | // Run the platform main event loop until the user types ^C. |
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202 | // The BrowseCallback routine is responsible for printing |
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203 | // any results that we find. |
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204 | |
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205 | if (status == mStatus_NoError) { |
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206 | fprintf(stderr, "Hit ^C when you're bored waiting for responses.\n"); |
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207 | ExampleClientEventLoop(&mDNSStorage); |
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208 | mDNS_StopQuery(&mDNSStorage, &question); |
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209 | mDNS_Close(&mDNSStorage); |
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210 | } |
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211 | } |
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212 | |
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213 | if (status == mStatus_NoError) { |
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214 | result = 0; |
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215 | } else { |
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216 | result = 2; |
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217 | } |
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218 | if ( (result != 0) || (gMDNSPlatformPosixVerboseLevel > 0) ) { |
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219 | fprintf(stderr, "%s: Finished with status %d, result %d\n", gProgramName, (int)status, result); |
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220 | } |
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221 | |
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222 | return 0; |
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223 | } |
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