Vidyashree Rama | 6d4f84e | 2015-09-21 20:01:02 +0530 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2015 Open Networking Laboratory |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package org.onosproject.bgpio.protocol.ver4; |
| 18 | |
| 19 | import java.util.LinkedList; |
| 20 | import java.util.ListIterator; |
| 21 | |
| 22 | import org.jboss.netty.buffer.ChannelBuffer; |
| 23 | import org.onosproject.bgpio.exceptions.BGPParseException; |
| 24 | import org.onosproject.bgpio.protocol.BGPMessageReader; |
| 25 | import org.onosproject.bgpio.protocol.BGPMessageWriter; |
| 26 | import org.onosproject.bgpio.protocol.BGPOpenMsg; |
| 27 | import org.onosproject.bgpio.protocol.BGPType; |
| 28 | import org.onosproject.bgpio.protocol.BGPVersion; |
| 29 | import org.onosproject.bgpio.types.BGPErrorType; |
| 30 | import org.onosproject.bgpio.types.BGPHeader; |
| 31 | import org.onosproject.bgpio.types.BGPValueType; |
| 32 | import org.onosproject.bgpio.util.Validation; |
| 33 | import org.slf4j.Logger; |
| 34 | import org.slf4j.LoggerFactory; |
| 35 | |
| 36 | import com.google.common.base.MoreObjects; |
| 37 | |
| 38 | /** |
| 39 | * Provides BGP open message. |
| 40 | */ |
| 41 | public class BGPOpenMsgVer4 implements BGPOpenMsg { |
| 42 | |
| 43 | /* |
| 44 | 0 1 2 3 |
| 45 | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
| 46 | +-+-+-+-+-+-+-+-+ |
| 47 | | Version | |
| 48 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 49 | | My Autonomous System | |
| 50 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 51 | | Hold Time | |
| 52 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 53 | | BGP Identifier | |
| 54 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 55 | | Opt Parm Len | |
| 56 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 57 | | Optional Parameters (variable) | |
| 58 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 59 | OPEN Message Format |
| 60 | REFERENCE : RFC 4271 |
| 61 | */ |
| 62 | |
| 63 | protected static final Logger log = LoggerFactory.getLogger(BGPOpenMsgVer4.class); |
| 64 | |
| 65 | public static final byte PACKET_VERSION = 4; |
| 66 | public static final int OPEN_MSG_MINIMUM_LENGTH = 10; |
| 67 | public static final int MSG_HEADER_LENGTH = 19; |
| 68 | public static final int MARKER_LENGTH = 16; |
| 69 | public static final int DEFAULT_HOLD_TIME = 120; |
| 70 | public static final int OPT_PARA_TYPE_CAPABILITY = 2; |
| 71 | public static final BGPType MSG_TYPE = BGPType.OPEN; |
| 72 | public static final byte[] MARKER = new byte[]{(byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, |
| 73 | (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, |
| 74 | (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff}; |
| 75 | public static final BGPHeader DEFAULT_OPEN_HEADER = new BGPHeader(MARKER, |
| 76 | (short) OPEN_MSG_MINIMUM_LENGTH, (byte) 0X01); |
| 77 | private BGPHeader bgpMsgHeader; |
| 78 | private byte version; |
| 79 | private short asNumber; |
| 80 | private short holdTime; |
| 81 | private int bgpId; |
| 82 | private LinkedList<BGPValueType> capabilityTlv; |
| 83 | |
| 84 | public static final BGPOpenMsgVer4.Reader READER = new Reader(); |
| 85 | |
| 86 | /** |
| 87 | * reset variables. |
| 88 | */ |
| 89 | public BGPOpenMsgVer4() { |
| 90 | this.bgpMsgHeader = null; |
| 91 | this.version = 0; |
| 92 | this.holdTime = 0; |
| 93 | this.asNumber = 0; |
| 94 | this.bgpId = 0; |
| 95 | this.capabilityTlv = null; |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * Constructor to initialize all variables of BGP Open message. |
| 100 | * |
| 101 | * @param bgpMsgHeader |
| 102 | * BGP Header in open message |
| 103 | * @param version |
| 104 | * BGP version in open message |
| 105 | * @param holdTime |
| 106 | * hold time in open message |
| 107 | * @param asNumber |
| 108 | * AS number in open message |
| 109 | * @param bgpId |
| 110 | * BGP identifier in open message |
| 111 | * @param capabilityTlv |
| 112 | * capabilities in open message |
| 113 | */ |
| 114 | public BGPOpenMsgVer4(BGPHeader bgpMsgHeader, byte version, short asNumber, short holdTime, |
| 115 | int bgpId, LinkedList<BGPValueType> capabilityTlv) { |
| 116 | this.bgpMsgHeader = bgpMsgHeader; |
| 117 | this.version = version; |
| 118 | this.asNumber = asNumber; |
| 119 | this.holdTime = holdTime; |
| 120 | this.bgpId = bgpId; |
| 121 | this.capabilityTlv = capabilityTlv; |
| 122 | } |
| 123 | |
| 124 | @Override |
| 125 | public BGPHeader getHeader() { |
| 126 | return this.bgpMsgHeader; |
| 127 | } |
| 128 | |
| 129 | @Override |
| 130 | public BGPVersion getVersion() { |
| 131 | return BGPVersion.BGP_4; |
| 132 | } |
| 133 | |
| 134 | @Override |
| 135 | public BGPType getType() { |
| 136 | return MSG_TYPE; |
| 137 | } |
| 138 | |
| 139 | @Override |
| 140 | public short getHoldTime() { |
| 141 | return this.holdTime; |
| 142 | } |
| 143 | |
| 144 | @Override |
| 145 | public short getAsNumber() { |
| 146 | return this.asNumber; |
| 147 | } |
| 148 | |
| 149 | @Override |
| 150 | public int getBgpId() { |
| 151 | return this.bgpId; |
| 152 | } |
| 153 | |
| 154 | @Override |
| 155 | public LinkedList<BGPValueType> getCapabilityTlv() { |
| 156 | return this.capabilityTlv; |
| 157 | } |
| 158 | |
| 159 | /** |
| 160 | * Reader class for reading BGP open message from channel buffer. |
| 161 | */ |
| 162 | public static class Reader implements BGPMessageReader<BGPOpenMsg> { |
| 163 | |
| 164 | @Override |
| 165 | public BGPOpenMsg readFrom(ChannelBuffer cb, BGPHeader bgpHeader) throws BGPParseException { |
| 166 | |
| 167 | byte version; |
| 168 | short holdTime; |
| 169 | short asNumber; |
| 170 | int bgpId; |
| 171 | byte optParaLen = 0; |
| 172 | byte optParaType; |
| 173 | byte capParaLen = 0; |
| 174 | LinkedList<BGPValueType> capabilityTlv = new LinkedList<>(); |
| 175 | |
| 176 | if (cb.readableBytes() < OPEN_MSG_MINIMUM_LENGTH) { |
| 177 | log.error("[readFrom] Invalid length: Packet size is less than the minimum length "); |
| 178 | Validation.validateLen(BGPErrorType.OPEN_MESSAGE_ERROR, BGPErrorType.BAD_MESSAGE_LENGTH, |
| 179 | cb.readableBytes()); |
| 180 | } |
| 181 | |
| 182 | // Read version |
| 183 | version = cb.readByte(); |
| 184 | if (version != PACKET_VERSION) { |
| 185 | log.error("[readFrom] Invalid version: " + version); |
| 186 | throw new BGPParseException(BGPErrorType.OPEN_MESSAGE_ERROR, |
| 187 | BGPErrorType.UNSUPPORTED_VERSION_NUMBER, null); |
| 188 | } |
| 189 | |
| 190 | // Read AS number |
| 191 | asNumber = cb.readShort(); |
| 192 | |
| 193 | // Read Hold timer |
| 194 | holdTime = cb.readShort(); |
| 195 | |
| 196 | // Read BGP Identifier |
| 197 | bgpId = cb.readInt(); |
| 198 | |
| 199 | // Read optional parameter length |
| 200 | optParaLen = cb.readByte(); |
| 201 | |
| 202 | // Read Capabilities if optional parameter length is greater than 0 |
| 203 | if (optParaLen != 0) { |
| 204 | // Read optional parameter type |
| 205 | optParaType = cb.readByte(); |
| 206 | |
| 207 | // Read optional parameter length |
| 208 | capParaLen = cb.readByte(); |
| 209 | |
| 210 | if (cb.readableBytes() < capParaLen) { |
| 211 | throw new BGPParseException(BGPErrorType.OPEN_MESSAGE_ERROR, (byte) 0, null); |
| 212 | } |
| 213 | |
| 214 | ChannelBuffer capaCb = cb.readBytes(capParaLen); |
| 215 | |
| 216 | // Parse capabilities only if optional parameter type is 2 |
| 217 | if ((optParaType == OPT_PARA_TYPE_CAPABILITY) && (capParaLen != 0)) { |
| 218 | capabilityTlv = parseCapabilityTlv(capaCb); |
| 219 | } else { |
| 220 | throw new BGPParseException(BGPErrorType.OPEN_MESSAGE_ERROR, |
| 221 | BGPErrorType.UNSUPPORTED_OPTIONAL_PARAMETER, null); |
| 222 | } |
| 223 | } |
| 224 | return new BGPOpenMsgVer4(bgpHeader, version, asNumber, holdTime, bgpId, capabilityTlv); |
| 225 | } |
| 226 | } |
| 227 | |
| 228 | /** |
| 229 | * Parsing capabilities. |
| 230 | * |
| 231 | * @param cb of type channel buffer |
| 232 | * @return capabilityTlv of open message |
| 233 | * @throws BGPParseException while parsing capabilities |
| 234 | */ |
| 235 | protected static LinkedList<BGPValueType> parseCapabilityTlv(ChannelBuffer cb) throws BGPParseException { |
| 236 | |
| 237 | LinkedList<BGPValueType> capabilityTlv = new LinkedList<>(); |
| 238 | |
| 239 | // TODO: Capability parsing |
| 240 | return capabilityTlv; |
| 241 | } |
| 242 | |
| 243 | /** |
| 244 | * Builder class for BGP open message. |
| 245 | */ |
| 246 | static class Builder implements BGPOpenMsg.Builder { |
| 247 | |
| 248 | private boolean isHeaderSet = false; |
| 249 | private BGPHeader bgpMsgHeader; |
| 250 | private boolean isHoldTimeSet = false; |
| 251 | private short holdTime; |
| 252 | private boolean isAsNumSet = false; |
| 253 | private short asNumber; |
| 254 | private boolean isBgpIdSet = false; |
| 255 | private int bgpId; |
| 256 | |
| 257 | LinkedList<BGPValueType> capabilityTlv = new LinkedList<>(); |
| 258 | |
| 259 | @Override |
| 260 | public BGPOpenMsg build() throws BGPParseException { |
| 261 | BGPHeader bgpMsgHeader = this.isHeaderSet ? this.bgpMsgHeader : DEFAULT_OPEN_HEADER; |
| 262 | short holdTime = this.isHoldTimeSet ? this.holdTime : DEFAULT_HOLD_TIME; |
| 263 | |
| 264 | if (!this.isAsNumSet) { |
| 265 | throw new BGPParseException("BGP AS number is not set (mandatory)"); |
| 266 | } |
| 267 | |
| 268 | if (!this.isBgpIdSet) { |
| 269 | throw new BGPParseException("BGPID is not set (mandatory)"); |
| 270 | } |
| 271 | |
| 272 | // TODO: capabilities build |
| 273 | |
| 274 | return new BGPOpenMsgVer4(bgpMsgHeader, PACKET_VERSION, this.asNumber, holdTime, this.bgpId, |
| 275 | this.capabilityTlv); |
| 276 | } |
| 277 | |
| 278 | @Override |
| 279 | public BGPHeader getHeader() { |
| 280 | return this.bgpMsgHeader; |
| 281 | } |
| 282 | |
| 283 | @Override |
| 284 | public Builder setHeader(BGPHeader bgpMsgHeader) { |
| 285 | this.bgpMsgHeader = bgpMsgHeader; |
| 286 | return this; |
| 287 | } |
| 288 | |
| 289 | @Override |
| 290 | public BGPVersion getVersion() { |
| 291 | return BGPVersion.BGP_4; |
| 292 | } |
| 293 | |
| 294 | @Override |
| 295 | public BGPType getType() { |
| 296 | return MSG_TYPE; |
| 297 | } |
| 298 | |
| 299 | @Override |
| 300 | public short getHoldTime() { |
| 301 | return this.holdTime; |
| 302 | } |
| 303 | |
| 304 | @Override |
| 305 | public short getAsNumber() { |
| 306 | return this.asNumber; |
| 307 | } |
| 308 | |
| 309 | @Override |
| 310 | public int getBgpId() { |
| 311 | return this.bgpId; |
| 312 | } |
| 313 | |
| 314 | @Override |
| 315 | public LinkedList<BGPValueType> getCapabilityTlv() { |
| 316 | return this.capabilityTlv; |
| 317 | } |
| 318 | |
| 319 | @Override |
| 320 | public Builder setHoldTime(short holdTime) { |
| 321 | this.holdTime = holdTime; |
| 322 | this.isHoldTimeSet = true; |
| 323 | return this; |
| 324 | } |
| 325 | |
| 326 | @Override |
| 327 | public Builder setAsNumber(short asNumber) { |
| 328 | this.asNumber = asNumber; |
| 329 | this.isAsNumSet = true; |
| 330 | return this; |
| 331 | } |
| 332 | |
| 333 | @Override |
| 334 | public Builder setBgpId(int bgpId) { |
| 335 | this.bgpId = bgpId; |
| 336 | this.isBgpIdSet = true; |
| 337 | return this; |
| 338 | } |
| 339 | |
| 340 | @Override |
| 341 | public Builder setCapabilityTlv(LinkedList<BGPValueType> capabilityTlv) { |
| 342 | this.capabilityTlv = capabilityTlv; |
| 343 | return this; |
| 344 | } |
| 345 | } |
| 346 | |
| 347 | @Override |
| 348 | public void writeTo(ChannelBuffer cb) { |
| 349 | try { |
| 350 | WRITER.write(cb, this); |
| 351 | } catch (BGPParseException e) { |
| 352 | log.debug("[writeTo] Error: " + e.toString()); |
| 353 | } |
| 354 | } |
| 355 | |
| 356 | public static final Writer WRITER = new Writer(); |
| 357 | |
| 358 | /** |
| 359 | * Writer class for writing BGP open message to channel buffer. |
| 360 | */ |
| 361 | public static class Writer implements BGPMessageWriter<BGPOpenMsgVer4> { |
| 362 | |
| 363 | @Override |
| 364 | public void write(ChannelBuffer cb, BGPOpenMsgVer4 message) throws BGPParseException { |
| 365 | |
| 366 | int optParaLen = 0; |
| 367 | |
| 368 | int startIndex = cb.writerIndex(); |
| 369 | |
| 370 | // write common header and get msg length index |
| 371 | int msgLenIndex = message.bgpMsgHeader.write(cb); |
| 372 | |
| 373 | if (msgLenIndex <= 0) { |
| 374 | throw new BGPParseException("Unable to write message header."); |
| 375 | } |
| 376 | |
| 377 | // write version in 1-octet |
| 378 | cb.writeByte(message.version); |
| 379 | |
| 380 | // TODO : Write AS number based on capabilities |
| 381 | cb.writeShort(message.asNumber); |
| 382 | |
| 383 | // write HoldTime in next 2-octet |
| 384 | cb.writeShort(message.holdTime); |
| 385 | |
| 386 | // write BGP Identifier in next 4-octet |
| 387 | cb.writeInt(message.bgpId); |
| 388 | |
| 389 | // store the index of Optional parameter length |
| 390 | int optParaLenIndex = cb.writerIndex(); |
| 391 | |
| 392 | // set optional parameter length as 0 |
| 393 | cb.writeByte(0); |
| 394 | |
| 395 | // Pack capability TLV |
| 396 | optParaLen = message.packCapabilityTlv(cb, message); |
| 397 | |
| 398 | if (optParaLen != 0) { |
| 399 | // Update optional parameter length |
| 400 | cb.setByte(optParaLenIndex, (byte) (optParaLen + 2)); //+2 for optional parameter type. |
| 401 | } |
| 402 | |
| 403 | // write OPEN Object Length |
| 404 | int length = cb.writerIndex() - startIndex; |
| 405 | cb.setShort(msgLenIndex, (short) length); |
| 406 | message.bgpMsgHeader.setLength((short) length); |
| 407 | } |
| 408 | } |
| 409 | |
| 410 | /** |
| 411 | * returns length of capability tlvs. |
| 412 | * |
| 413 | * @param cb of type channel buffer |
| 414 | * @param message of type BGPOpenMsgVer4 |
| 415 | * @return capParaLen of open message |
| 416 | */ |
| 417 | protected int packCapabilityTlv(ChannelBuffer cb, BGPOpenMsgVer4 message) { |
| 418 | int startIndex = cb.writerIndex(); |
| 419 | int capParaLen = 0; |
| 420 | int capParaLenIndex = 0; |
| 421 | |
| 422 | LinkedList<BGPValueType> capabilityTlv = message.capabilityTlv; |
| 423 | ListIterator<BGPValueType> listIterator = capabilityTlv.listIterator(); |
| 424 | |
| 425 | if (listIterator.hasNext()) { |
| 426 | // Set optional parameter type as 2 |
| 427 | cb.writeByte(OPT_PARA_TYPE_CAPABILITY); |
| 428 | |
| 429 | // Store the index of capability parameter length and update length at the end |
| 430 | capParaLenIndex = cb.writerIndex(); |
| 431 | |
| 432 | // Set capability parameter length as 0 |
| 433 | cb.writeByte(0); |
| 434 | |
| 435 | // Update the startIndex to know the length of capability tlv |
| 436 | startIndex = cb.writerIndex(); |
| 437 | } |
| 438 | |
| 439 | while (listIterator.hasNext()) { |
| 440 | BGPValueType tlv = listIterator.next(); |
| 441 | if (tlv == null) { |
| 442 | log.debug("Warning: tlv is null from CapabilityTlv list"); |
| 443 | continue; |
| 444 | } |
| 445 | tlv.write(cb); |
| 446 | } |
| 447 | |
| 448 | capParaLen = cb.writerIndex() - startIndex; |
| 449 | |
| 450 | if (capParaLen != 0) { |
| 451 | // Update capability parameter length |
| 452 | cb.setByte(capParaLenIndex, (byte) capParaLen); |
| 453 | } |
| 454 | return capParaLen; |
| 455 | } |
| 456 | |
| 457 | @Override |
| 458 | public String toString() { |
| 459 | return MoreObjects.toStringHelper(getClass()) |
| 460 | .add("bgpMsgHeader", bgpMsgHeader) |
| 461 | .add("version", version) |
| 462 | .add("holdTime", holdTime) |
| 463 | .add("asNumber", asNumber) |
| 464 | .add("bgpId", bgpId) |
| 465 | .add("capabilityTlv", capabilityTlv) |
| 466 | .toString(); |
| 467 | } |
| 468 | } |