Clients/dnssdutil/dns-rcode-func-autogen

   1 #! /bin/bash
   2 #
   3 #       Copyright (c) 2020 Apple Inc. All rights reserved.
   4 #
   5
   6 declare -r version=1.0
   7 declare -r script=${BASH_SOURCE[0]}
   8 declare -r rcodesURL='https://www.iana.org/assignments/dns-parameters/dns-parameters-6.csv'
   9
  10 #============================================================================================================================
  11
  12 PrintHelp()
  13 {
  14         echo ""
  15         echo "Usage: $( basename "${script}" ) [options]"
  16         echo ""
  17         echo "Options:"
  18         echo "    -h  Display script usage."
  19         echo "    -V  Display version of this script and exit."
  20         echo ""
  21         echo "This script writes C functions to convert DNS RCODE values to strings and vice versa to stdout"
  22         echo "based on the latest DNS RCODE data available at"
  23         echo ""
  24         echo "    ${rcodesURL}"
  25         echo ""
  26 }
  27
  28 #============================================================================================================================
  29
  30 ErrQuit()
  31 {
  32         echo "error: $*" 1>&2
  33         exit 1
  34 }
  35
  36 #============================================================================================================================
  37
  38 StripLeadingTrailingWhitespace()
  39 {
  40         sed 's/^[[:space:]]*//;s/[[:space:]]*$//'
  41 }
  42
  43 #============================================================================================================================
  44
  45 GetNamesAndValues()
  46 {
  47         shopt -s nocasematch
  48         while IFS=',' read value name others; do
  49                 name=$( StripLeadingTrailingWhitespace <<< "${name}" )
  50                 [[ ${name} =~ ^unassigned$ ]] && continue
  51
  52                 value=$( StripLeadingTrailingWhitespace <<< "${value}" )
  53                 [[ ${value} =~ ^[0-9]+$ ]] || continue
  54                 [ "${value}" -le 15 ] || continue
  55
  56                 echo "${name},${value}"
  57         done
  58         shopt -u nocasematch
  59 }
  60
  61 #============================================================================================================================
  62
  63 RCodeMnemonicToEnum()
  64 {
  65         name="${1//[^A-Za-z0-9_]/_}" # Only allow alphanumeric and underscore characters.
  66         printf "kDNSRCode_${name}"
  67 }
  68
  69 #============================================================================================================================
  70
  71 PrintRCodeEnums()
  72 {
  73         local -r inputFile=${1}
  74         printf "typedef enum\n"
  75         printf "{\n"
  76         local sep=""
  77         < "${inputFile}" sort --field-separator=, --key=2,2 --numeric-sort --unique |
  78         while IFS=',' read name value; do
  79                 printf "%b" "${sep}"
  80                 local enum=$( RCodeMnemonicToEnum "${name}" )
  81                 printf "\t%-20s= %d" "${enum}" "${value}"
  82                 sep=",\n"
  83         done
  84         printf "\n"
  85         printf "\t\n"
  86         printf "}\tDNSRCode;\n"
  87 }
  88
  89 #============================================================================================================================
  90
  91 PrintValueToStringElseIf()
  92 {
  93         local -r first=${1}
  94         local -r last=${2}
  95         [ "${first}" -le "${last}" ] || ErrQuit "${first} > ${last}"
  96         shift 2
  97         local stringArray=( "$@" )
  98
  99         if [ "${last}" -ne "${first}" ]; then
 100                 printf "\telse if( ( inValue >= ${first} ) && ( inValue <= ${last} ) )\n"
 101                 local -r arrayVarName="sNames_${first}_${last}"
 102         else
 103                 printf "\telse if( inValue == ${first} )\n"
 104                 local -r arrayVarName="sNames_${first}"
 105         fi
 106         printf "\t{\n"
 107         printf "\t\tstatic const char * const\t\t${arrayVarName}[] =\n"
 108         printf "\t\t{\n"
 109         local value=${first}
 110         for string in "${stringArray[@]}"; do
 111                 printf "\t\t\t%-15s // %3d\n" "\"${string}\"," "${value}"
 112                 value=$(( value + 1 ))
 113         done
 114         local -r stringCount=$(( value - first ))
 115         local -r expectedCount=$(( last - first + 1 ))
 116         [ "${stringCount}" -eq "${expectedCount}" ] || ErrQuit "${stringCount} != ${expectedCount}"
 117         printf "\t\t};\n"
 118         printf "\t\tstring = ${arrayVarName}[ inValue - ${first} ];\n"
 119         printf "\t}\n"
 120 }
 121
 122 #============================================================================================================================
 123
 124 PrintValueToStringFunction()
 125 {
 126         local -r inputFile=${1}
 127         printf "const char *\tDNSRCodeToString( const int inValue )\n"
 128         printf "{\n"
 129         printf "\tswitch( inValue )\n"
 130         printf "\t{\n"
 131         < "${inputFile}" sort --field-separator=, --key=2,2 --numeric-sort --unique |
 132         {
 133                 local stringArray=()
 134                 while IFS=',' read name value; do
 135                     local enum=$( RCodeMnemonicToEnum "${name}" )
 136                         printf "\t\t%-28s%s\n" "case ${enum}:" "return( \"${name}\" );"
 137                 done
 138         }
 139         printf "\t\t%-28sreturn( NULL );\n" "default:"
 140         printf "\t}\n"
 141         printf "}\n"
 142 }
 143
 144 #============================================================================================================================
 145
 146 PrintStringToValueFunction()
 147 {
 148         local -r inputFile=${1}
 149         printf "#include <stdlib.h>\n"
 150         printf "\n"
 151         printf "typedef struct\n"
 152         printf "{\n"
 153         printf "\tconst char *\t\tname;\n"
 154         printf "\tint\t\t\t\t\tvalue;\n"
 155         printf "\t\n"
 156         printf "}\t_DNSRCodeTableEntry;\n"
 157         printf "\n"
 158         printf "static int\t_DNSRCodeFromStringCmp( const void *inKey, const void *inElement );\n"
 159         printf "\n"
 160         printf "int\tDNSRCodeFromString( const char * const inString )\n"
 161         printf "{\n"
 162         printf "\t// The name-value table is sorted by name in ascending lexicographical order to allow going from name to\n"
 163         printf "\t// value in logarithmic time via a binary search.\n"
 164         printf "\t\n"
 165         printf "\tstatic const _DNSRCodeTableEntry\t\tsTable[] =\n"
 166         printf "\t{\n"
 167
 168         local sep=""
 169         < "${inputFile}" sort --field-separator=, --key=1,1 --ignore-case --unique |
 170         while IFS=',' read name value; do
 171                 printf "%b" "${sep}"
 172                 local enum=$( RCodeMnemonicToEnum "${name}" )
 173                 printf "\t\t%-16s%-20s}" "{ \"${name}\"," "${enum}"
 174                 sep=",\n"
 175         done
 176         printf "\n"
 177         printf "\t};\n"
 178         printf "\tconst _DNSRCodeTableEntry *\t\t\tentry;\n"
 179         printf "\t\n"
 180         printf "\tentry = (_DNSRCodeTableEntry *) bsearch( inString, sTable, sizeof( sTable ) / sizeof( sTable[ 0 ] ),\n"
 181         printf "\t\tsizeof( sTable[ 0 ] ), _DNSRCodeFromStringCmp );\n"
 182         printf "\treturn( entry ? entry->value : -1 );\n"
 183         printf "}\n"
 184         printf "\n"
 185         printf "static int\t_DNSRCodeFromStringCmp( const void * const inKey, const void * const inElement )\n"
 186         printf "{\n"
 187         printf "\tconst _DNSRCodeTableEntry * const\t\tentry = (const _DNSRCodeTableEntry *) inElement;\n"
 188         printf "\treturn( strcasecmp( (const char *) inKey, entry->name ) );\n"
 189         printf "}\n"
 190 }
 191
 192 #============================================================================================================================
 193
 194 ExitHandler()
 195 {
 196         if [ -d "${tempDir}" ]; then
 197                 rm -fr "${tempDir}"
 198         fi
 199 }
 200
 201 #============================================================================================================================
 202
 203 PrintAutoGenNote()
 204 {
 205         printf "// This code was autogenerated on $( date -u '+%Y-%m-%d' ) by $( basename ${script} ) version ${version}\n"
 206         printf "// Data source URL: ${rcodesURL}\n"
 207         printf "\n"
 208 }
 209
 210 #============================================================================================================================
 211
 212 main()
 213 {
 214         while getopts ":hO:V" option; do
 215                 case "${option}" in
 216                         h)
 217                                 PrintHelp
 218                                 exit 0
 219                                 ;;
 220                         V)
 221                                 echo "$( basename "${script}" ) version ${version}"
 222                                 exit 0
 223                                 ;;
 224                         :)
 225                                 ErrQuit "option '${OPTARG}' requires an argument."
 226                                 ;;
 227                         *)
 228                                 ErrQuit "unknown option '${OPTARG}'."
 229                                 ;;
 230                 esac
 231         done
 232
 233         [ "${OPTIND}" -gt "$#" ] || ErrQuit "unexpected argument \"${!OPTIND}\"."
 234
 235         trap ExitHandler EXIT
 236         tempDir=$( mktemp -d ) || ErrQuit "Failed to make temporary directory."
 237         declare -r originalRCodesFile="${tempDir}/rcodesOriginal.csv"
 238         curl --output "${originalRCodesFile}" "${rcodesURL}" || ErrQuit "Failed to download CSV file."
 239
 240         declare -r rcodesFile="${tempDir}/rcodes.csv"
 241         < "${originalRCodesFile}" GetNamesAndValues > "${rcodesFile}"
 242
 243         declare -r tempFile="${tempDir}/temp.csv"
 244         < "${rcodesFile}" sort --field-separator=, --key=2,2 --unique --numeric-sort > "${tempFile}"
 245         < "${tempFile}" sort --field-separator=, --key=1,1 --unique --ignore-case > "${rcodesFile}"
 246
 247         PrintAutoGenNote
 248         PrintRCodeEnums "${rcodesFile}"
 249         printf "\n"
 250         PrintAutoGenNote
 251         PrintValueToStringFunction "${rcodesFile}"
 252         printf "\n"
 253         PrintAutoGenNote
 254         PrintStringToValueFunction "${rcodesFile}"
 255 }
 256
 257 main "$@"