Shuyi Chen | d7955ce | 2013-05-22 14:51:55 -0700 | [diff] [blame] | 1 | // Copyright (c) 2004 Brian Wellington (bwelling@xbill.org) |
| 2 | |
| 3 | package org.xbill.DNS; |
| 4 | |
| 5 | import java.io.*; |
| 6 | import java.util.*; |
| 7 | |
| 8 | /** |
| 9 | * A representation of a $GENERATE statement in a master file. |
| 10 | * |
| 11 | * @author Brian Wellington |
| 12 | */ |
| 13 | |
| 14 | public class Generator { |
| 15 | |
| 16 | /** The start of the range. */ |
| 17 | public long start; |
| 18 | |
| 19 | /** The end of the range. */ |
| 20 | public long end; |
| 21 | |
| 22 | /** The step value of the range. */ |
| 23 | public long step; |
| 24 | |
| 25 | /** The pattern to use for generating record names. */ |
| 26 | public final String namePattern; |
| 27 | |
| 28 | /** The type of the generated records. */ |
| 29 | public final int type; |
| 30 | |
| 31 | /** The class of the generated records. */ |
| 32 | public final int dclass; |
| 33 | |
| 34 | /** The ttl of the generated records. */ |
| 35 | public final long ttl; |
| 36 | |
| 37 | /** The pattern to use for generating record data. */ |
| 38 | public final String rdataPattern; |
| 39 | |
| 40 | /** The origin to append to relative names. */ |
| 41 | public final Name origin; |
| 42 | |
| 43 | private long current; |
| 44 | |
| 45 | /** |
| 46 | * Indicates whether generation is supported for this type. |
| 47 | * @throws InvalidTypeException The type is out of range. |
| 48 | */ |
| 49 | public static boolean |
| 50 | supportedType(int type) { |
| 51 | Type.check(type); |
| 52 | return (type == Type.PTR || type == Type.CNAME || type == Type.DNAME || |
| 53 | type == Type.A || type == Type.AAAA || type == Type.NS); |
| 54 | } |
| 55 | |
| 56 | /** |
| 57 | * Creates a specification for generating records, as a $GENERATE |
| 58 | * statement in a master file. |
| 59 | * @param start The start of the range. |
| 60 | * @param end The end of the range. |
| 61 | * @param step The step value of the range. |
| 62 | * @param namePattern The pattern to use for generating record names. |
| 63 | * @param type The type of the generated records. The supported types are |
| 64 | * PTR, CNAME, DNAME, A, AAAA, and NS. |
| 65 | * @param dclass The class of the generated records. |
| 66 | * @param ttl The ttl of the generated records. |
| 67 | * @param rdataPattern The pattern to use for generating record data. |
| 68 | * @param origin The origin to append to relative names. |
| 69 | * @throws IllegalArgumentException The range is invalid. |
| 70 | * @throws IllegalArgumentException The type does not support generation. |
| 71 | * @throws IllegalArgumentException The dclass is not a valid class. |
| 72 | */ |
| 73 | public |
| 74 | Generator(long start, long end, long step, String namePattern, |
| 75 | int type, int dclass, long ttl, String rdataPattern, Name origin) |
| 76 | { |
| 77 | if (start < 0 || end < 0 || start > end || step <= 0) |
| 78 | throw new IllegalArgumentException |
| 79 | ("invalid range specification"); |
| 80 | if (!supportedType(type)) |
| 81 | throw new IllegalArgumentException("unsupported type"); |
| 82 | DClass.check(dclass); |
| 83 | |
| 84 | this.start = start; |
| 85 | this.end = end; |
| 86 | this.step = step; |
| 87 | this.namePattern = namePattern; |
| 88 | this.type = type; |
| 89 | this.dclass = dclass; |
| 90 | this.ttl = ttl; |
| 91 | this.rdataPattern = rdataPattern; |
| 92 | this.origin = origin; |
| 93 | this.current = start; |
| 94 | } |
| 95 | |
| 96 | private String |
| 97 | substitute(String spec, long n) throws IOException { |
| 98 | boolean escaped = false; |
| 99 | byte [] str = spec.getBytes(); |
| 100 | StringBuffer sb = new StringBuffer(); |
| 101 | |
| 102 | for (int i = 0; i < str.length; i++) { |
| 103 | char c = (char)(str[i] & 0xFF); |
| 104 | if (escaped) { |
| 105 | sb.append(c); |
| 106 | escaped = false; |
| 107 | } else if (c == '\\') { |
| 108 | if (i + 1 == str.length) |
| 109 | throw new TextParseException |
| 110 | ("invalid escape character"); |
| 111 | escaped = true; |
| 112 | } else if (c == '$') { |
| 113 | boolean negative = false; |
| 114 | long offset = 0; |
| 115 | long width = 0; |
| 116 | long base = 10; |
| 117 | boolean wantUpperCase = false; |
| 118 | if (i + 1 < str.length && str[i + 1] == '$') { |
| 119 | // '$$' == literal '$' for backwards |
| 120 | // compatibility with old versions of BIND. |
| 121 | c = (char)(str[++i] & 0xFF); |
| 122 | sb.append(c); |
| 123 | continue; |
| 124 | } else if (i + 1 < str.length && str[i + 1] == '{') { |
| 125 | // It's a substitution with modifiers. |
| 126 | i++; |
| 127 | if (i + 1 < str.length && str[i + 1] == '-') { |
| 128 | negative = true; |
| 129 | i++; |
| 130 | } |
| 131 | while (i + 1 < str.length) { |
| 132 | c = (char)(str[++i] & 0xFF); |
| 133 | if (c == ',' || c == '}') |
| 134 | break; |
| 135 | if (c < '0' || c > '9') |
| 136 | throw new TextParseException( |
| 137 | "invalid offset"); |
| 138 | c -= '0'; |
| 139 | offset *= 10; |
| 140 | offset += c; |
| 141 | } |
| 142 | if (negative) |
| 143 | offset = -offset; |
| 144 | |
| 145 | if (c == ',') { |
| 146 | while (i + 1 < str.length) { |
| 147 | c = (char)(str[++i] & 0xFF); |
| 148 | if (c == ',' || c == '}') |
| 149 | break; |
| 150 | if (c < '0' || c > '9') |
| 151 | throw new |
| 152 | TextParseException( |
| 153 | "invalid width"); |
| 154 | c -= '0'; |
| 155 | width *= 10; |
| 156 | width += c; |
| 157 | } |
| 158 | } |
| 159 | |
| 160 | if (c == ',') { |
| 161 | if (i + 1 == str.length) |
| 162 | throw new TextParseException( |
| 163 | "invalid base"); |
| 164 | c = (char)(str[++i] & 0xFF); |
| 165 | if (c == 'o') |
| 166 | base = 8; |
| 167 | else if (c == 'x') |
| 168 | base = 16; |
| 169 | else if (c == 'X') { |
| 170 | base = 16; |
| 171 | wantUpperCase = true; |
| 172 | } |
| 173 | else if (c != 'd') |
| 174 | throw new TextParseException( |
| 175 | "invalid base"); |
| 176 | } |
| 177 | |
| 178 | if (i + 1 == str.length || str[i + 1] != '}') |
| 179 | throw new TextParseException |
| 180 | ("invalid modifiers"); |
| 181 | i++; |
| 182 | } |
| 183 | long v = n + offset; |
| 184 | if (v < 0) |
| 185 | throw new TextParseException |
| 186 | ("invalid offset expansion"); |
| 187 | String number; |
| 188 | if (base == 8) |
| 189 | number = Long.toOctalString(v); |
| 190 | else if (base == 16) |
| 191 | number = Long.toHexString(v); |
| 192 | else |
| 193 | number = Long.toString(v); |
| 194 | if (wantUpperCase) |
| 195 | number = number.toUpperCase(); |
| 196 | if (width != 0 && width > number.length()) { |
| 197 | int zeros = (int)width - number.length(); |
| 198 | while (zeros-- > 0) |
| 199 | sb.append('0'); |
| 200 | } |
| 201 | sb.append(number); |
| 202 | } else { |
| 203 | sb.append(c); |
| 204 | } |
| 205 | } |
| 206 | return sb.toString(); |
| 207 | } |
| 208 | |
| 209 | /** |
| 210 | * Constructs and returns the next record in the expansion. |
| 211 | * @throws IOException The name or rdata was invalid after substitutions were |
| 212 | * performed. |
| 213 | */ |
| 214 | public Record |
| 215 | nextRecord() throws IOException { |
| 216 | if (current > end) |
| 217 | return null; |
| 218 | String namestr = substitute(namePattern, current); |
| 219 | Name name = Name.fromString(namestr, origin); |
| 220 | String rdata = substitute(rdataPattern, current); |
| 221 | current += step; |
| 222 | return Record.fromString(name, type, dclass, ttl, rdata, origin); |
| 223 | } |
| 224 | |
| 225 | /** |
| 226 | * Constructs and returns all records in the expansion. |
| 227 | * @throws IOException The name or rdata of a record was invalid after |
| 228 | * substitutions were performed. |
| 229 | */ |
| 230 | public Record [] |
| 231 | expand() throws IOException { |
| 232 | List list = new ArrayList(); |
| 233 | for (long i = start; i < end; i += step) { |
| 234 | String namestr = substitute(namePattern, current); |
| 235 | Name name = Name.fromString(namestr, origin); |
| 236 | String rdata = substitute(rdataPattern, current); |
| 237 | list.add(Record.fromString(name, type, dclass, ttl, |
| 238 | rdata, origin)); |
| 239 | } |
| 240 | return (Record []) list.toArray(new Record[list.size()]); |
| 241 | } |
| 242 | |
| 243 | /** |
| 244 | * Converts the generate specification to a string containing the corresponding |
| 245 | * $GENERATE statement. |
| 246 | */ |
| 247 | public String |
| 248 | toString() { |
| 249 | StringBuffer sb = new StringBuffer(); |
| 250 | sb.append("$GENERATE "); |
| 251 | sb.append(start + "-" + end); |
| 252 | if (step > 1) |
| 253 | sb.append("/" + step); |
| 254 | sb.append(" "); |
| 255 | sb.append(namePattern + " "); |
| 256 | sb.append(ttl + " "); |
| 257 | if (dclass != DClass.IN || !Options.check("noPrintIN")) |
| 258 | sb.append(DClass.string(dclass) + " "); |
| 259 | sb.append(Type.string(type) + " "); |
| 260 | sb.append(rdataPattern + " "); |
| 261 | return sb.toString(); |
| 262 | } |
| 263 | |
| 264 | } |