1 /* 2 * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.net; 27 28 import java.util.Arrays; 29 import java.util.Enumeration; 30 import java.util.NoSuchElementException; 31 import java.security.AccessController; 32 import java.util.Spliterator; 33 import java.util.Spliterators; 34 import java.util.stream.Stream; 35 import java.util.stream.StreamSupport; 36 37 /** 38 * This class represents a Network Interface made up of a name, 39 * and a list of IP addresses assigned to this interface. 40 * It is used to identify the local interface on which a multicast group 41 * is joined. 42 * 43 * Interfaces are normally known by names such as "le0". 44 * 45 * @since 1.4 46 */ 47 public final class NetworkInterface { 48 private String name; 49 private String displayName; 50 private int index; 51 private InetAddress[] addrs; 52 private InterfaceAddress[] bindings; 53 private NetworkInterface[] childs; 54 private NetworkInterface parent = null; 55 private boolean virtual = false; 56 private static final NetworkInterface defaultInterface; 57 private static final int defaultIndex; /* index of defaultInterface */ 58 59 static { 60 AccessController.doPrivileged( 61 new java.security.PrivilegedAction<>() { 62 public Void run() { 63 System.loadLibrary("net"); 64 return null; 65 } 66 }); 67 68 init(); 69 defaultInterface = DefaultInterface.getDefault(); 70 if (defaultInterface != null) { 71 defaultIndex = defaultInterface.getIndex(); 72 } else { 73 defaultIndex = 0; 74 } 75 } 76 77 /** 78 * Returns an NetworkInterface object with index set to 0 and name to null. 79 * Setting such an interface on a MulticastSocket will cause the 80 * kernel to choose one interface for sending multicast packets. 81 * 82 */ 83 NetworkInterface() { 84 } 85 86 NetworkInterface(String name, int index, InetAddress[] addrs) { 87 this.name = name; 88 this.index = index; 89 this.addrs = addrs; 90 } 91 92 /** 93 * Get the name of this network interface. 94 * 95 * @return the name of this network interface 96 */ 97 public String getName() { 98 return name; 99 } 100 101 /** 102 * Get an Enumeration with all or a subset of the InetAddresses bound to 103 * this network interface. 104 * <p> 105 * If there is a security manager, its {@code checkConnect} 106 * method is called for each InetAddress. Only InetAddresses where 107 * the {@code checkConnect} doesn't throw a SecurityException 108 * will be returned in the Enumeration. However, if the caller has the 109 * {@link NetPermission}("getNetworkInformation") permission, then all 110 * InetAddresses are returned. 111 * 112 * @return an Enumeration object with all or a subset of the InetAddresses 113 * bound to this network interface 114 * @see #inetAddresses() 115 */ 116 public Enumeration<InetAddress> getInetAddresses() { 117 return enumerationFromArray(getCheckedInetAddresses()); 118 } 119 120 /** 121 * Get a Stream of all or a subset of the InetAddresses bound to this 122 * network interface. 123 * <p> 124 * If there is a security manager, its {@code checkConnect} 125 * method is called for each InetAddress. Only InetAddresses where 126 * the {@code checkConnect} doesn't throw a SecurityException will be 127 * returned in the Stream. However, if the caller has the 128 * {@link NetPermission}("getNetworkInformation") permission, then all 129 * InetAddresses are returned. 130 * 131 * @return a Stream object with all or a subset of the InetAddresses 132 * bound to this network interface 133 * @since 9 134 */ 135 public Stream<InetAddress> inetAddresses() { 136 return streamFromArray(getCheckedInetAddresses()); 137 } 138 139 private InetAddress[] getCheckedInetAddresses() { 140 InetAddress[] local_addrs = new InetAddress[addrs.length]; 141 boolean trusted = true; 142 143 SecurityManager sec = System.getSecurityManager(); 144 if (sec != null) { 145 try { 146 sec.checkPermission(new NetPermission("getNetworkInformation")); 147 } catch (SecurityException e) { 148 trusted = false; 149 } 150 } 151 int i = 0; 152 for (int j = 0; j < addrs.length; j++) { 153 try { 154 if (!trusted) { 155 sec.checkConnect(addrs[j].getHostAddress(), -1); 156 } 157 local_addrs[i++] = addrs[j]; 158 } catch (SecurityException e) { } 159 } 160 return Arrays.copyOf(local_addrs, i); 161 } 162 163 /** 164 * Get a List of all or a subset of the {@code InterfaceAddresses} 165 * of this network interface. 166 * <p> 167 * If there is a security manager, its {@code checkConnect} 168 * method is called with the InetAddress for each InterfaceAddress. 169 * Only InterfaceAddresses where the {@code checkConnect} doesn't throw 170 * a SecurityException will be returned in the List. 171 * 172 * @return a {@code List} object with all or a subset of the 173 * InterfaceAddresss of this network interface 174 * @since 1.6 175 */ 176 public java.util.List<InterfaceAddress> getInterfaceAddresses() { 177 java.util.List<InterfaceAddress> lst = new java.util.ArrayList<>(1); 178 if (bindings != null) { 179 SecurityManager sec = System.getSecurityManager(); 180 for (int j=0; j<bindings.length; j++) { 181 try { 182 if (sec != null) { 183 sec.checkConnect(bindings[j].getAddress().getHostAddress(), -1); 184 } 185 lst.add(bindings[j]); 186 } catch (SecurityException e) { } 187 } 188 } 189 return lst; 190 } 191 192 /** 193 * Get an Enumeration with all the subinterfaces (also known as virtual 194 * interfaces) attached to this network interface. 195 * <p> 196 * For instance eth0:1 will be a subinterface to eth0. 197 * 198 * @return an Enumeration object with all of the subinterfaces 199 * of this network interface 200 * @see #subInterfaces() 201 * @since 1.6 202 */ 203 public Enumeration<NetworkInterface> getSubInterfaces() { 204 return enumerationFromArray(childs); 205 } 206 207 /** 208 * Get a Stream of all subinterfaces (also known as virtual 209 * interfaces) attached to this network interface. 210 * 211 * @return a Stream object with all of the subinterfaces 212 * of this network interface 213 * @since 9 214 */ 215 public Stream<NetworkInterface> subInterfaces() { 216 return streamFromArray(childs); 217 } 218 219 /** 220 * Returns the parent NetworkInterface of this interface if this is 221 * a subinterface, or {@code null} if it is a physical 222 * (non virtual) interface or has no parent. 223 * 224 * @return The {@code NetworkInterface} this interface is attached to. 225 * @since 1.6 226 */ 227 public NetworkInterface getParent() { 228 return parent; 229 } 230 231 /** 232 * Returns the index of this network interface. The index is an integer greater 233 * or equal to zero, or {@code -1} for unknown. This is a system specific value 234 * and interfaces with the same name can have different indexes on different 235 * machines. 236 * 237 * @return the index of this network interface or {@code -1} if the index is 238 * unknown 239 * @see #getByIndex(int) 240 * @since 1.7 241 */ 242 public int getIndex() { 243 return index; 244 } 245 246 /** 247 * Get the display name of this network interface. 248 * A display name is a human readable String describing the network 249 * device. 250 * 251 * @return a non-empty string representing the display name of this network 252 * interface, or null if no display name is available. 253 */ 254 public String getDisplayName() { 255 /* strict TCK conformance */ 256 return "".equals(displayName) ? null : displayName; 257 } 258 259 /** 260 * Searches for the network interface with the specified name. 261 * 262 * @param name 263 * The name of the network interface. 264 * 265 * @return A {@code NetworkInterface} with the specified name, 266 * or {@code null} if there is no network interface 267 * with the specified name. 268 * 269 * @throws SocketException 270 * If an I/O error occurs. 271 * 272 * @throws NullPointerException 273 * If the specified name is {@code null}. 274 */ 275 public static NetworkInterface getByName(String name) throws SocketException { 276 if (name == null) 277 throw new NullPointerException(); 278 return getByName0(name); 279 } 280 281 /** 282 * Get a network interface given its index. 283 * 284 * @param index an integer, the index of the interface 285 * @return the NetworkInterface obtained from its index, or {@code null} if 286 * there is no interface with such an index on the system 287 * @throws SocketException if an I/O error occurs. 288 * @throws IllegalArgumentException if index has a negative value 289 * @see #getIndex() 290 * @since 1.7 291 */ 292 public static NetworkInterface getByIndex(int index) throws SocketException { 293 if (index < 0) 294 throw new IllegalArgumentException("Interface index can't be negative"); 295 return getByIndex0(index); 296 } 297 298 /** 299 * Convenience method to search for a network interface that 300 * has the specified Internet Protocol (IP) address bound to 301 * it. 302 * <p> 303 * If the specified IP address is bound to multiple network 304 * interfaces it is not defined which network interface is 305 * returned. 306 * 307 * @param addr 308 * The {@code InetAddress} to search with. 309 * 310 * @return A {@code NetworkInterface} 311 * or {@code null} if there is no network interface 312 * with the specified IP address. 313 * 314 * @throws SocketException 315 * If an I/O error occurs. 316 * 317 * @throws NullPointerException 318 * If the specified address is {@code null}. 319 */ 320 public static NetworkInterface getByInetAddress(InetAddress addr) throws SocketException { 321 if (addr == null) { 322 throw new NullPointerException(); 323 } 324 if (!(addr instanceof Inet4Address || addr instanceof Inet6Address)) { 325 throw new IllegalArgumentException ("invalid address type"); 326 } 327 return getByInetAddress0(addr); 328 } 329 330 /** 331 * Returns an {@code Enumeration} of all the interfaces on this machine. The 332 * {@code Enumeration} contains at least one element, possibly representing 333 * a loopback interface that only supports communication between entities on 334 * this machine. 335 * 336 * @apiNote this method can be used in combination with 337 * {@link #getInetAddresses()} to obtain all IP addresses for this node 338 * 339 * @return an Enumeration of NetworkInterfaces found on this machine 340 * @exception SocketException if an I/O error occurs, 341 * or if the platform does not have at least one configured 342 * network interface. 343 * @see #networkInterfaces() 344 */ 345 public static Enumeration<NetworkInterface> getNetworkInterfaces() 346 throws SocketException { 347 NetworkInterface[] netifs = getAll(); 348 if (netifs != null && netifs.length > 0) { 349 return enumerationFromArray(netifs); 350 } else { 351 throw new SocketException("No network interfaces configured"); 352 } 353 } 354 355 /** 356 * Returns a {@code Stream} of all the interfaces on this machine. The 357 * {@code Stream} contains at least one interface, possibly representing a 358 * loopback interface that only supports communication between entities on 359 * this machine. 360 * 361 * @apiNote this method can be used in combination with 362 * {@link #inetAddresses()}} to obtain a stream of all IP addresses for 363 * this node, for example: 364 * <pre> {@code 365 * Stream<InetAddress> addrs = NetworkInterface.networkInterfaces() 366 * .flatMap(NetworkInterface::inetAddresses); 367 * }</pre> 368 * 369 * @return a Stream of NetworkInterfaces found on this machine 370 * @exception SocketException if an I/O error occurs, 371 * or if the platform does not have at least one configured 372 * network interface. 373 * @since 9 374 */ 375 public static Stream<NetworkInterface> networkInterfaces() 376 throws SocketException { 377 NetworkInterface[] netifs = getAll(); 378 if (netifs != null && netifs.length > 0) { 379 return streamFromArray(netifs); 380 } else { 381 throw new SocketException("No network interfaces configured"); 382 } 383 } 384 385 private static <T> Enumeration<T> enumerationFromArray(T[] a) { 386 return new Enumeration<>() { 387 int i = 0; 388 389 @Override 390 public T nextElement() { 391 if (i < a.length) { 392 return a[i++]; 393 } else { 394 throw new NoSuchElementException(); 395 } 396 } 397 398 @Override 399 public boolean hasMoreElements() { 400 return i < a.length; 401 } 402 }; 403 } 404 405 private static <T> Stream<T> streamFromArray(T[] a) { 406 return StreamSupport.stream( 407 Spliterators.spliterator( 408 a, 409 Spliterator.DISTINCT | Spliterator.IMMUTABLE | Spliterator.NONNULL), 410 false); 411 } 412 413 private static native NetworkInterface[] getAll() 414 throws SocketException; 415 416 private static native NetworkInterface getByName0(String name) 417 throws SocketException; 418 419 private static native NetworkInterface getByIndex0(int index) 420 throws SocketException; 421 422 private static native NetworkInterface getByInetAddress0(InetAddress addr) 423 throws SocketException; 424 425 /** 426 * Returns whether a network interface is up and running. 427 * 428 * @return {@code true} if the interface is up and running. 429 * @exception SocketException if an I/O error occurs. 430 * @since 1.6 431 */ 432 433 public boolean isUp() throws SocketException { 434 return isUp0(name, index); 435 } 436 437 /** 438 * Returns whether a network interface is a loopback interface. 439 * 440 * @return {@code true} if the interface is a loopback interface. 441 * @exception SocketException if an I/O error occurs. 442 * @since 1.6 443 */ 444 445 public boolean isLoopback() throws SocketException { 446 return isLoopback0(name, index); 447 } 448 449 /** 450 * Returns whether a network interface is a point to point interface. 451 * A typical point to point interface would be a PPP connection through 452 * a modem. 453 * 454 * @return {@code true} if the interface is a point to point 455 * interface. 456 * @exception SocketException if an I/O error occurs. 457 * @since 1.6 458 */ 459 460 public boolean isPointToPoint() throws SocketException { 461 return isP2P0(name, index); 462 } 463 464 /** 465 * Returns whether a network interface supports multicasting or not. 466 * 467 * @return {@code true} if the interface supports Multicasting. 468 * @exception SocketException if an I/O error occurs. 469 * @since 1.6 470 */ 471 472 public boolean supportsMulticast() throws SocketException { 473 return supportsMulticast0(name, index); 474 } 475 476 /** 477 * Returns the hardware address (usually MAC) of the interface if it 478 * has one and if it can be accessed given the current privileges. 479 * If a security manager is set, then the caller must have 480 * the permission {@link NetPermission}("getNetworkInformation"). 481 * 482 * @return a byte array containing the address, or {@code null} if 483 * the address doesn't exist, is not accessible or a security 484 * manager is set and the caller does not have the permission 485 * NetPermission("getNetworkInformation") 486 * 487 * @exception SocketException if an I/O error occurs. 488 * @since 1.6 489 */ 490 public byte[] getHardwareAddress() throws SocketException { 491 SecurityManager sec = System.getSecurityManager(); 492 if (sec != null) { 493 try { 494 sec.checkPermission(new NetPermission("getNetworkInformation")); 495 } catch (SecurityException e) { 496 if (!getInetAddresses().hasMoreElements()) { 497 // don't have connect permission to any local address 498 return null; 499 } 500 } 501 } 502 for (InetAddress addr : addrs) { 503 if (addr instanceof Inet4Address) { 504 return getMacAddr0(((Inet4Address)addr).getAddress(), name, index); 505 } 506 } 507 return getMacAddr0(null, name, index); 508 } 509 510 /** 511 * Returns the Maximum Transmission Unit (MTU) of this interface. 512 * 513 * @return the value of the MTU for that interface. 514 * @exception SocketException if an I/O error occurs. 515 * @since 1.6 516 */ 517 public int getMTU() throws SocketException { 518 return getMTU0(name, index); 519 } 520 521 /** 522 * Returns whether this interface is a virtual interface (also called 523 * subinterface). 524 * Virtual interfaces are, on some systems, interfaces created as a child 525 * of a physical interface and given different settings (like address or 526 * MTU). Usually the name of the interface will the name of the parent 527 * followed by a colon (:) and a number identifying the child since there 528 * can be several virtual interfaces attached to a single physical 529 * interface. 530 * 531 * @return {@code true} if this interface is a virtual interface. 532 * @since 1.6 533 */ 534 public boolean isVirtual() { 535 return virtual; 536 } 537 538 private static native boolean isUp0(String name, int ind) throws SocketException; 539 private static native boolean isLoopback0(String name, int ind) throws SocketException; 540 private static native boolean supportsMulticast0(String name, int ind) throws SocketException; 541 private static native boolean isP2P0(String name, int ind) throws SocketException; 542 private static native byte[] getMacAddr0(byte[] inAddr, String name, int ind) throws SocketException; 543 private static native int getMTU0(String name, int ind) throws SocketException; 544 545 /** 546 * Compares this object against the specified object. 547 * The result is {@code true} if and only if the argument is 548 * not {@code null} and it represents the same NetworkInterface 549 * as this object. 550 * <p> 551 * Two instances of {@code NetworkInterface} represent the same 552 * NetworkInterface if both name and addrs are the same for both. 553 * 554 * @param obj the object to compare against. 555 * @return {@code true} if the objects are the same; 556 * {@code false} otherwise. 557 * @see java.net.InetAddress#getAddress() 558 */ 559 public boolean equals(Object obj) { 560 if (!(obj instanceof NetworkInterface)) { 561 return false; 562 } 563 NetworkInterface that = (NetworkInterface)obj; 564 if (this.name != null ) { 565 if (!this.name.equals(that.name)) { 566 return false; 567 } 568 } else { 569 if (that.name != null) { 570 return false; 571 } 572 } 573 574 if (this.addrs == null) { 575 return that.addrs == null; 576 } else if (that.addrs == null) { 577 return false; 578 } 579 580 /* Both addrs not null. Compare number of addresses */ 581 582 if (this.addrs.length != that.addrs.length) { 583 return false; 584 } 585 586 InetAddress[] thatAddrs = that.addrs; 587 int count = thatAddrs.length; 588 589 for (int i=0; i<count; i++) { 590 boolean found = false; 591 for (int j=0; j<count; j++) { 592 if (addrs[i].equals(thatAddrs[j])) { 593 found = true; 594 break; 595 } 596 } 597 if (!found) { 598 return false; 599 } 600 } 601 return true; 602 } 603 604 public int hashCode() { 605 return name == null? 0: name.hashCode(); 606 } 607 608 public String toString() { 609 String result = "name:"; 610 result += name == null? "null": name; 611 if (displayName != null) { 612 result += " (" + displayName + ")"; 613 } 614 return result; 615 } 616 617 private static native void init(); 618 619 /** 620 * Returns the default network interface of this system 621 * 622 * @return the default interface 623 */ 624 static NetworkInterface getDefault() { 625 return defaultInterface; 626 } 627 }