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.net.*; |
| 7 | import java.util.*; |
| 8 | import org.xbill.DNS.utils.*; |
| 9 | |
| 10 | /** |
| 11 | * APL - Address Prefix List. See RFC 3123. |
| 12 | * |
| 13 | * @author Brian Wellington |
| 14 | */ |
| 15 | |
| 16 | /* |
| 17 | * Note: this currently uses the same constants as the Address class; |
| 18 | * this could change if more constants are defined for APL records. |
| 19 | */ |
| 20 | |
| 21 | public class APLRecord extends Record { |
| 22 | |
| 23 | public static class Element { |
| 24 | public final int family; |
| 25 | public final boolean negative; |
| 26 | public final int prefixLength; |
| 27 | public final Object address; |
| 28 | |
| 29 | private |
| 30 | Element(int family, boolean negative, Object address, int prefixLength) |
| 31 | { |
| 32 | this.family = family; |
| 33 | this.negative = negative; |
| 34 | this.address = address; |
| 35 | this.prefixLength = prefixLength; |
| 36 | if (!validatePrefixLength(family, prefixLength)) { |
| 37 | throw new IllegalArgumentException("invalid prefix " + |
| 38 | "length"); |
| 39 | } |
| 40 | } |
| 41 | |
| 42 | /** |
| 43 | * Creates an APL element corresponding to an IPv4 or IPv6 prefix. |
| 44 | * @param negative Indicates if this prefix is a negation. |
| 45 | * @param address The IPv4 or IPv6 address. |
| 46 | * @param prefixLength The length of this prefix, in bits. |
| 47 | * @throws IllegalArgumentException The prefix length is invalid. |
| 48 | */ |
| 49 | public |
| 50 | Element(boolean negative, InetAddress address, int prefixLength) { |
| 51 | this(Address.familyOf(address), negative, address, |
| 52 | prefixLength); |
| 53 | } |
| 54 | |
| 55 | public String |
| 56 | toString() { |
| 57 | StringBuffer sb = new StringBuffer(); |
| 58 | if (negative) |
| 59 | sb.append("!"); |
| 60 | sb.append(family); |
| 61 | sb.append(":"); |
| 62 | if (family == Address.IPv4 || family == Address.IPv6) |
| 63 | sb.append(((InetAddress) address).getHostAddress()); |
| 64 | else |
| 65 | sb.append(base16.toString((byte []) address)); |
| 66 | sb.append("/"); |
| 67 | sb.append(prefixLength); |
| 68 | return sb.toString(); |
| 69 | } |
| 70 | |
| 71 | public boolean |
| 72 | equals(Object arg) { |
| 73 | if (arg == null || !(arg instanceof Element)) |
| 74 | return false; |
| 75 | Element elt = (Element) arg; |
| 76 | return (family == elt.family && |
| 77 | negative == elt.negative && |
| 78 | prefixLength == elt.prefixLength && |
| 79 | address.equals(elt.address)); |
| 80 | } |
| 81 | |
| 82 | public int |
| 83 | hashCode() { |
| 84 | return address.hashCode() + prefixLength + (negative ? 1 : 0); |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | private static final long serialVersionUID = -1348173791712935864L; |
| 89 | |
| 90 | private List elements; |
| 91 | |
| 92 | APLRecord() {} |
| 93 | |
| 94 | Record |
| 95 | getObject() { |
| 96 | return new APLRecord(); |
| 97 | } |
| 98 | |
| 99 | private static boolean |
| 100 | validatePrefixLength(int family, int prefixLength) { |
| 101 | if (prefixLength < 0 || prefixLength >= 256) |
| 102 | return false; |
| 103 | if ((family == Address.IPv4 && prefixLength > 32) || |
| 104 | (family == Address.IPv6 && prefixLength > 128)) |
| 105 | return false; |
| 106 | return true; |
| 107 | } |
| 108 | |
| 109 | /** |
| 110 | * Creates an APL Record from the given data. |
| 111 | * @param elements The list of APL elements. |
| 112 | */ |
| 113 | public |
| 114 | APLRecord(Name name, int dclass, long ttl, List elements) { |
| 115 | super(name, Type.APL, dclass, ttl); |
| 116 | this.elements = new ArrayList(elements.size()); |
| 117 | for (Iterator it = elements.iterator(); it.hasNext(); ) { |
| 118 | Object o = it.next(); |
| 119 | if (!(o instanceof Element)) { |
| 120 | throw new IllegalArgumentException("illegal element"); |
| 121 | } |
| 122 | Element element = (Element) o; |
| 123 | if (element.family != Address.IPv4 && |
| 124 | element.family != Address.IPv6) |
| 125 | { |
| 126 | throw new IllegalArgumentException("unknown family"); |
| 127 | } |
| 128 | this.elements.add(element); |
| 129 | |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | private static byte [] |
| 134 | parseAddress(byte [] in, int length) throws WireParseException { |
| 135 | if (in.length > length) |
| 136 | throw new WireParseException("invalid address length"); |
| 137 | if (in.length == length) |
| 138 | return in; |
| 139 | byte [] out = new byte[length]; |
| 140 | System.arraycopy(in, 0, out, 0, in.length); |
| 141 | return out; |
| 142 | } |
| 143 | |
| 144 | void |
| 145 | rrFromWire(DNSInput in) throws IOException { |
| 146 | elements = new ArrayList(1); |
| 147 | while (in.remaining() != 0) { |
| 148 | int family = in.readU16(); |
| 149 | int prefix = in.readU8(); |
| 150 | int length = in.readU8(); |
| 151 | boolean negative = (length & 0x80) != 0; |
| 152 | length &= ~0x80; |
| 153 | |
| 154 | byte [] data = in.readByteArray(length); |
| 155 | Element element; |
| 156 | if (!validatePrefixLength(family, prefix)) { |
| 157 | throw new WireParseException("invalid prefix length"); |
| 158 | } |
| 159 | |
| 160 | if (family == Address.IPv4 || family == Address.IPv6) { |
| 161 | data = parseAddress(data, |
| 162 | Address.addressLength(family)); |
| 163 | InetAddress addr = InetAddress.getByAddress(data); |
| 164 | element = new Element(negative, addr, prefix); |
| 165 | } else { |
| 166 | element = new Element(family, negative, data, prefix); |
| 167 | } |
| 168 | elements.add(element); |
| 169 | |
| 170 | } |
| 171 | } |
| 172 | |
| 173 | void |
| 174 | rdataFromString(Tokenizer st, Name origin) throws IOException { |
| 175 | elements = new ArrayList(1); |
| 176 | while (true) { |
| 177 | Tokenizer.Token t = st.get(); |
| 178 | if (!t.isString()) |
| 179 | break; |
| 180 | |
| 181 | boolean negative = false; |
| 182 | int family = 0; |
| 183 | int prefix = 0; |
| 184 | |
| 185 | String s = t.value; |
| 186 | int start = 0; |
| 187 | if (s.startsWith("!")) { |
| 188 | negative = true; |
| 189 | start = 1; |
| 190 | } |
| 191 | int colon = s.indexOf(':', start); |
| 192 | if (colon < 0) |
| 193 | throw st.exception("invalid address prefix element"); |
| 194 | int slash = s.indexOf('/', colon); |
| 195 | if (slash < 0) |
| 196 | throw st.exception("invalid address prefix element"); |
| 197 | |
| 198 | String familyString = s.substring(start, colon); |
| 199 | String addressString = s.substring(colon + 1, slash); |
| 200 | String prefixString = s.substring(slash + 1); |
| 201 | |
| 202 | try { |
| 203 | family = Integer.parseInt(familyString); |
| 204 | } |
| 205 | catch (NumberFormatException e) { |
| 206 | throw st.exception("invalid family"); |
| 207 | } |
| 208 | if (family != Address.IPv4 && family != Address.IPv6) |
| 209 | throw st.exception("unknown family"); |
| 210 | |
| 211 | try { |
| 212 | prefix = Integer.parseInt(prefixString); |
| 213 | } |
| 214 | catch (NumberFormatException e) { |
| 215 | throw st.exception("invalid prefix length"); |
| 216 | } |
| 217 | |
| 218 | if (!validatePrefixLength(family, prefix)) { |
| 219 | throw st.exception("invalid prefix length"); |
| 220 | } |
| 221 | |
| 222 | byte [] bytes = Address.toByteArray(addressString, family); |
| 223 | if (bytes == null) |
| 224 | throw st.exception("invalid IP address " + |
| 225 | addressString); |
| 226 | |
| 227 | InetAddress address = InetAddress.getByAddress(bytes); |
| 228 | elements.add(new Element(negative, address, prefix)); |
| 229 | } |
| 230 | st.unget(); |
| 231 | } |
| 232 | |
| 233 | String |
| 234 | rrToString() { |
| 235 | StringBuffer sb = new StringBuffer(); |
| 236 | for (Iterator it = elements.iterator(); it.hasNext(); ) { |
| 237 | Element element = (Element) it.next(); |
| 238 | sb.append(element); |
| 239 | if (it.hasNext()) |
| 240 | sb.append(" "); |
| 241 | } |
| 242 | return sb.toString(); |
| 243 | } |
| 244 | |
| 245 | /** Returns the list of APL elements. */ |
| 246 | public List |
| 247 | getElements() { |
| 248 | return elements; |
| 249 | } |
| 250 | |
| 251 | private static int |
| 252 | addressLength(byte [] addr) { |
| 253 | for (int i = addr.length - 1; i >= 0; i--) { |
| 254 | if (addr[i] != 0) |
| 255 | return i + 1; |
| 256 | } |
| 257 | return 0; |
| 258 | } |
| 259 | |
| 260 | void |
| 261 | rrToWire(DNSOutput out, Compression c, boolean canonical) { |
| 262 | for (Iterator it = elements.iterator(); it.hasNext(); ) { |
| 263 | Element element = (Element) it.next(); |
| 264 | int length = 0; |
| 265 | byte [] data; |
| 266 | if (element.family == Address.IPv4 || |
| 267 | element.family == Address.IPv6) |
| 268 | { |
| 269 | InetAddress addr = (InetAddress) element.address; |
| 270 | data = addr.getAddress(); |
| 271 | length = addressLength(data); |
| 272 | } else { |
| 273 | data = (byte []) element.address; |
| 274 | length = data.length; |
| 275 | } |
| 276 | int wlength = length; |
| 277 | if (element.negative) { |
| 278 | wlength |= 0x80; |
| 279 | } |
| 280 | out.writeU16(element.family); |
| 281 | out.writeU8(element.prefixLength); |
| 282 | out.writeU8(wlength); |
| 283 | out.writeByteArray(data, 0, length); |
| 284 | } |
| 285 | } |
| 286 | |
| 287 | } |