1 /*
  2  * Copyright (c) 2000, 2020, 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 #include <ctype.h>
 26 #include <errno.h>
 27 #include <stdlib.h>
 28 #include <string.h>
 29 #include <sys/time.h>
 30 #include <sys/types.h>
 31 #include <netinet/in.h>
 32 #include <netinet/icmp6.h>
 33 
 34 #if defined(_ALLBSD_SOURCE)
 35 #include <ifaddrs.h>
 36 #include <net/if.h>
 37 #endif
 38 
 39 #include "net_util.h"
 40 
 41 #include "java_net_InetAddress.h"
 42 #include "java_net_Inet4AddressImpl.h"
 43 #include "java_net_Inet6AddressImpl.h"


 44 
 45 #define SET_NONBLOCKING(fd) {       \
 46     int flags = fcntl(fd, F_GETFL); \
 47     flags |= O_NONBLOCK;            \
 48     fcntl(fd, F_SETFL, flags);      \
 49 }
 50 
 51 /*
 52  * Inet6AddressImpl
 53  */
 54 
 55 /*
 56  * Class:     java_net_Inet6AddressImpl
 57  * Method:    getLocalHostName
 58  * Signature: ()Ljava/lang/String;
 59  */
 60 JNIEXPORT jstring JNICALL
 61 Java_java_net_Inet6AddressImpl_getLocalHostName(JNIEnv *env, jobject this) {
 62     char hostname[NI_MAXHOST + 1];
 63 
 64     hostname[0] = '\0';
 65     if (gethostname(hostname, sizeof(hostname)) != 0) {
 66         strcpy(hostname, "localhost");
 67     } else {
 68         // make sure string is null-terminated
 69         hostname[NI_MAXHOST] = '\0';
 70     }
 71     return (*env)->NewStringUTF(env, hostname);
 72 }
 73 
 74 #if defined(MACOSX)
 75 /* also called from Inet4AddressImpl.c */
 76 __private_extern__ jobjectArray
 77 lookupIfLocalhost(JNIEnv *env, const char *hostname, jboolean includeV6)
 78 {
 79     jobjectArray result = NULL;
 80     char myhostname[NI_MAXHOST + 1];
 81     struct ifaddrs *ifa = NULL;
 82     int familyOrder = 0;
 83     int count = 0, i, j;
 84     int addrs4 = 0, addrs6 = 0, numV4Loopbacks = 0, numV6Loopbacks = 0;
 85     jboolean includeLoopback = JNI_FALSE;
 86     jobject name;
 87 
 88     initInetAddressIDs(env);
 89     JNU_CHECK_EXCEPTION_RETURN(env, NULL);
 90 
 91     /* If the requested name matches this host's hostname, return IP addresses
 92      * from all attached interfaces. (#2844683 et al) This prevents undesired
 93      * PPP dialup, but may return addresses that don't actually correspond to
 94      * the name (if the name actually matches something in DNS etc.
 95      */
 96     myhostname[0] = '\0';
 97     if (gethostname(myhostname, sizeof(myhostname)) == -1) {
 98         /* Something went wrong, maybe networking is not setup? */
 99         return NULL;
100     }
101     myhostname[NI_MAXHOST] = '\0';
102 
103     if (strcmp(myhostname, hostname) != 0) {
104         // Non-self lookup
105         return NULL;
106     }
107 
108     if (getifaddrs(&ifa) != 0) {
109         NET_ThrowNew(env, errno, "Can't get local interface addresses");
110         return NULL;
111     }
112 
113     name = (*env)->NewStringUTF(env, hostname);
114     if (name == NULL) {
115         freeifaddrs(ifa);
116         return NULL;
117     }
118 
119     /* Iterate over the interfaces, and total up the number of IPv4 and IPv6
120      * addresses we have. Also keep a count of loopback addresses. We need to
121      * exclude them in the normal case, but return them if we don't get an IP
122      * address.
123      */
124     struct ifaddrs *iter = ifa;
125     while (iter) {
126         if (iter->ifa_addr != NULL) {
127             int family = iter->ifa_addr->sa_family;
128             if (iter->ifa_name[0] != '\0') {
129                 jboolean isLoopback = iter->ifa_flags & IFF_LOOPBACK;
130                 if (family == AF_INET) {
131                     addrs4++;
132                     if (isLoopback) numV4Loopbacks++;
133                 } else if (family == AF_INET6 && includeV6) {
134                     addrs6++;
135                     if (isLoopback) numV6Loopbacks++;
136                 } // else we don't care, e.g. AF_LINK
137             }
138         }
139         iter = iter->ifa_next;
140     }
141 
142     if (addrs4 == numV4Loopbacks && addrs6 == numV6Loopbacks) {
143         // We don't have a real IP address, just loopback. We need to include
144         // loopback in our results.
145         includeLoopback = JNI_TRUE;
146     }
147 
148     /* Create and fill the Java array. */
149     int arraySize = addrs4 + addrs6 -
150         (includeLoopback ? 0 : (numV4Loopbacks + numV6Loopbacks));
151     result = (*env)->NewObjectArray(env, arraySize, ia_class, NULL);
152     if (!result) goto done;
153 
154     if ((*env)->GetStaticBooleanField(env, ia_class, ia_preferIPv6AddressID)) {
155         i = includeLoopback ? addrs6 : (addrs6 - numV6Loopbacks);
156         j = 0;
157     } else {
158         i = 0;
159         j = includeLoopback ? addrs4 : (addrs4 - numV4Loopbacks);
160     }
161 
162     // Now loop around the ifaddrs
163     iter = ifa;
164     while (iter != NULL) {
165         if (iter->ifa_addr != NULL) {
166             jboolean isLoopback = iter->ifa_flags & IFF_LOOPBACK;
167             int family = iter->ifa_addr->sa_family;
168 
169             if (iter->ifa_name[0] != '\0' &&
170                 (family == AF_INET || (family == AF_INET6 && includeV6)) &&
171                 (!isLoopback || includeLoopback))
172             {
173                 int port;
174                 int index = (family == AF_INET) ? i++ : j++;
175                 jobject o = NET_SockaddrToInetAddress(env,
176                                 (SOCKETADDRESS *)iter->ifa_addr, &port);
177                 if (!o) {
178                     freeifaddrs(ifa);
179                     if (!(*env)->ExceptionCheck(env))
180                         JNU_ThrowOutOfMemoryError(env, "Object allocation failed");
181                     return NULL;
182                 }
183                 setInetAddress_hostName(env, o, name);
184                 if ((*env)->ExceptionCheck(env))
185                     goto done;
186                 (*env)->SetObjectArrayElement(env, result, index, o);
187                 (*env)->DeleteLocalRef(env, o);
188             }
189         }
190         iter = iter->ifa_next;
191     }
192 
193   done:
194     freeifaddrs(ifa);
195 
196     return result;
197 }
198 #endif
199 
200 /*
201  * Class:     java_net_Inet6AddressImpl
202  * Method:    lookupAllHostAddr
203  * Signature: (Ljava/lang/String;)[[B
204  */
205 JNIEXPORT jobjectArray JNICALL
206 Java_java_net_Inet6AddressImpl_lookupAllHostAddr(JNIEnv *env, jobject this,
207                                                  jstring host) {
208     jobjectArray ret = NULL;
209     const char *hostname;
210     int error = 0;
211     struct addrinfo hints, *res = NULL, *resNew = NULL, *last = NULL,
212         *iterator;
213 
214     initInetAddressIDs(env);
215     JNU_CHECK_EXCEPTION_RETURN(env, NULL);
216 
217     if (IS_NULL(host)) {
218         JNU_ThrowNullPointerException(env, "host argument is null");
219         return NULL;
220     }
221     hostname = JNU_GetStringPlatformChars(env, host, JNI_FALSE);
222     CHECK_NULL_RETURN(hostname, NULL);
223 
224     // try once, with our static buffer
225     memset(&hints, 0, sizeof(hints));
226     hints.ai_flags = AI_CANONNAME;
227     hints.ai_family = AF_UNSPEC;
228 
229     error = getaddrinfo(hostname, NULL, &hints, &res);
230 
231     if (error) {
232 #if defined(MACOSX)
233         // if getaddrinfo fails try getifaddrs
234         ret = lookupIfLocalhost(env, hostname, JNI_TRUE);
235         if (ret != NULL || (*env)->ExceptionCheck(env)) {
236             goto cleanupAndReturn;
237         }
238 #endif
239         // report error
240         NET_ThrowUnknownHostExceptionWithGaiError(env, hostname, error);
241         goto cleanupAndReturn;
242     } else {
243         int i = 0, inetCount = 0, inet6Count = 0, inetIndex = 0,
244             inet6Index = 0, originalIndex = 0;
245         int addressPreference =
246             (*env)->GetStaticIntField(env, ia_class, ia_preferIPv6AddressID);;
247         iterator = res;
248         while (iterator != NULL) {
249             // skip duplicates
250             int skip = 0;
251             struct addrinfo *iteratorNew = resNew;
252             while (iteratorNew != NULL) {
253                 if (iterator->ai_family == iteratorNew->ai_family &&
254                     iterator->ai_addrlen == iteratorNew->ai_addrlen) {
255                     if (iteratorNew->ai_family == AF_INET) { /* AF_INET */
256                         struct sockaddr_in *addr1, *addr2;
257                         addr1 = (struct sockaddr_in *)iterator->ai_addr;
258                         addr2 = (struct sockaddr_in *)iteratorNew->ai_addr;
259                         if (addr1->sin_addr.s_addr == addr2->sin_addr.s_addr) {
260                             skip = 1;
261                             break;
262                         }
263                     } else {
264                         int t;
265                         struct sockaddr_in6 *addr1, *addr2;
266                         addr1 = (struct sockaddr_in6 *)iterator->ai_addr;
267                         addr2 = (struct sockaddr_in6 *)iteratorNew->ai_addr;
268 
269                         for (t = 0; t < 16; t++) {
270                             if (addr1->sin6_addr.s6_addr[t] !=
271                                 addr2->sin6_addr.s6_addr[t]) {
272                                 break;
273                             }
274                         }
275                         if (t < 16) {
276                             iteratorNew = iteratorNew->ai_next;
277                             continue;
278                         } else {
279                             skip = 1;
280                             break;
281                         }
282                     }
283                 } else if (iterator->ai_family != AF_INET &&
284                            iterator->ai_family != AF_INET6) {
285                     // we can't handle other family types
286                     skip = 1;
287                     break;
288                 }
289                 iteratorNew = iteratorNew->ai_next;
290             }
291 
292             if (!skip) {
293                 struct addrinfo *next
294                     = (struct addrinfo *)malloc(sizeof(struct addrinfo));
295                 if (!next) {
296                     JNU_ThrowOutOfMemoryError(env, "Native heap allocation failed");
297                     ret = NULL;
298                     goto cleanupAndReturn;
299                 }
300                 memcpy(next, iterator, sizeof(struct addrinfo));
301                 next->ai_next = NULL;
302                 if (resNew == NULL) {
303                     resNew = next;
304                 } else {
305                     last->ai_next = next;
306                 }
307                 last = next;
308                 i++;
309                 if (iterator->ai_family == AF_INET) {
310                     inetCount++;
311                 } else if (iterator->ai_family == AF_INET6) {
312                     inet6Count++;
313                 }
314             }
315             iterator = iterator->ai_next;
316         }
317 
318         // allocate array - at this point i contains the number of addresses
319         ret = (*env)->NewObjectArray(env, i, ia_class, NULL);
320         if (IS_NULL(ret)) {
321             /* we may have memory to free at the end of this */
322             goto cleanupAndReturn;
323         }
324 
325         if (addressPreference == java_net_InetAddress_PREFER_IPV6_VALUE) {
326             inetIndex = inet6Count;
327             inet6Index = 0;
328         } else if (addressPreference == java_net_InetAddress_PREFER_IPV4_VALUE) {
329             inetIndex = 0;
330             inet6Index = inetCount;
331         } else if (addressPreference == java_net_InetAddress_PREFER_SYSTEM_VALUE) {
332             inetIndex = inet6Index = originalIndex = 0;
333         }
334 
335         iterator = resNew;
336         while (iterator != NULL) {
337             if (iterator->ai_family == AF_INET) {
338                 jobject iaObj = (*env)->NewObject(env, ia4_class, ia4_ctrID);
339                 if (IS_NULL(iaObj)) {
340                     ret = NULL;
341                     goto cleanupAndReturn;
342                 }
343                 setInetAddress_addr(env, iaObj, ntohl(((struct sockaddr_in*)iterator->ai_addr)->sin_addr.s_addr));
344                 if ((*env)->ExceptionCheck(env))
345                     goto cleanupAndReturn;
346                 setInetAddress_hostName(env, iaObj, host);
347                 if ((*env)->ExceptionCheck(env))
348                     goto cleanupAndReturn;
349                 (*env)->SetObjectArrayElement(env, ret, (inetIndex | originalIndex), iaObj);
350                 inetIndex++;
351             } else if (iterator->ai_family == AF_INET6) {
352                 jint scope = 0;
353                 jboolean ret1;
354                 jobject iaObj = (*env)->NewObject(env, ia6_class, ia6_ctrID);
355                 if (IS_NULL(iaObj)) {
356                     ret = NULL;
357                     goto cleanupAndReturn;
358                 }
359                 ret1 = setInet6Address_ipaddress(env, iaObj, (char *)&(((struct sockaddr_in6*)iterator->ai_addr)->sin6_addr));
360                 if (ret1 == JNI_FALSE) {
361                     ret = NULL;
362                     goto cleanupAndReturn;
363                 }
364                 scope = ((struct sockaddr_in6 *)iterator->ai_addr)->sin6_scope_id;
365                 if (scope != 0) { // zero is default value, no need to set
366                     setInet6Address_scopeid(env, iaObj, scope);
367                 }
368                 setInetAddress_hostName(env, iaObj, host);
369                 if ((*env)->ExceptionCheck(env))
370                     goto cleanupAndReturn;
371                 (*env)->SetObjectArrayElement(env, ret, (inet6Index | originalIndex), iaObj);
372                 inet6Index++;
373             }
374             if (addressPreference == java_net_InetAddress_PREFER_SYSTEM_VALUE) {

375                 originalIndex++;
376                 inetIndex = inet6Index = 0;
377             }
378             iterator = iterator->ai_next;
379         }
380     }
381 cleanupAndReturn:
382     JNU_ReleaseStringPlatformChars(env, host, hostname);
383     while (resNew != NULL) {
384         last = resNew;
385         resNew = resNew->ai_next;
386         free(last);
387     }
388     if (res != NULL) {
389         freeaddrinfo(res);
390     }
391     return ret;
392 }
393 
394 /*
395  * Class:     java_net_Inet6AddressImpl
396  * Method:    getHostByAddr
397  * Signature: ([B)Ljava/lang/String;
398  *
399  * Theoretically the UnknownHostException could be enriched with gai error
400  * information. But as it is silently ignored anyway, there's no need for this.
401  * It's only important that either a valid hostname is returned or an
402  * UnknownHostException is thrown.
403  */
404 JNIEXPORT jstring JNICALL
405 Java_java_net_Inet6AddressImpl_getHostByAddr(JNIEnv *env, jobject this,
406                                              jbyteArray addrArray) {
407     jstring ret = NULL;
408     char host[NI_MAXHOST + 1];
409     int len = 0;
410     jbyte caddr[16];
411     SOCKETADDRESS sa;
412 
413     memset((void *)&sa, 0, sizeof(SOCKETADDRESS));
414 
415     // construct a sockaddr_in structure (AF_INET or AF_INET6)
416     if ((*env)->GetArrayLength(env, addrArray) == 4) {
417         jint addr;
418         (*env)->GetByteArrayRegion(env, addrArray, 0, 4, caddr);
419         addr = ((caddr[0] << 24) & 0xff000000);
420         addr |= ((caddr[1] << 16) & 0xff0000);
421         addr |= ((caddr[2] << 8) & 0xff00);
422         addr |= (caddr[3] & 0xff);
423         sa.sa4.sin_addr.s_addr = htonl(addr);
424         sa.sa4.sin_family = AF_INET;
425         len = sizeof(struct sockaddr_in);
426     } else {
427         (*env)->GetByteArrayRegion(env, addrArray, 0, 16, caddr);
428         memcpy((void *)&sa.sa6.sin6_addr, caddr, sizeof(struct in6_addr));
429         sa.sa6.sin6_family = AF_INET6;
430         len = sizeof(struct sockaddr_in6);
431     }
432 
433     if (getnameinfo(&sa.sa, len, host, sizeof(host), NULL, 0, NI_NAMEREQD)) {
434         JNU_ThrowByName(env, "java/net/UnknownHostException", NULL);
435     } else {
436         ret = (*env)->NewStringUTF(env, host);
437         if (ret == NULL) {
438             JNU_ThrowByName(env, "java/net/UnknownHostException", NULL);
439         }
440     }
441 
442     return ret;
443 }
444 
445 /**
446  * ping implementation using tcp port 7 (echo)
447  */
448 static jboolean
449 tcp_ping6(JNIEnv *env, SOCKETADDRESS *sa, SOCKETADDRESS *netif, jint timeout,
450           jint ttl)
451 {
452     jint fd;
453     int connect_rv = -1;
454 
455     // open a TCP socket
456     fd = socket(AF_INET6, SOCK_STREAM, 0);
457     if (fd == -1) {
458         // note: if you run out of fds, you may not be able to load
459         // the exception class, and get a NoClassDefFoundError instead.
460         NET_ThrowNew(env, errno, "Can't create socket");
461         return JNI_FALSE;
462     }
463 
464     // set TTL
465     if (ttl > 0) {
466         setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
467     }
468 
469     // A network interface was specified, so let's bind to it.
470     if (netif != NULL) {
471         if (bind(fd, &netif->sa, sizeof(struct sockaddr_in6)) <0) {
472             NET_ThrowNew(env, errno, "Can't bind socket");
473             close(fd);
474             return JNI_FALSE;
475         }
476     }
477 
478     // Make the socket non blocking so we can use select/poll.
479     SET_NONBLOCKING(fd);
480 
481     sa->sa6.sin6_port = htons(7); // echo port
482     connect_rv = NET_Connect(fd, &sa->sa, sizeof(struct sockaddr_in6));
483 
484     // connection established or refused immediately, either way it means
485     // we were able to reach the host!
486     if (connect_rv == 0 || errno == ECONNREFUSED) {
487         close(fd);
488         return JNI_TRUE;
489     }
490 
491     switch (errno) {
492     case ENETUNREACH:   // Network Unreachable
493     case EAFNOSUPPORT:  // Address Family not supported
494     case EADDRNOTAVAIL: // address is not available on the remote machine
495 #if defined(__linux__) || defined(_AIX)
496         // On some Linux versions, when a socket is bound to the loopback
497         // interface, connect will fail and errno will be set to EINVAL
498         // or EHOSTUNREACH.  When that happens, don't throw an exception,
499         // just return false.
500     case EINVAL:
501     case EHOSTUNREACH:  // No route to host
502 #endif
503         close(fd);
504         return JNI_FALSE;
505     case EINPROGRESS:   // this is expected as we'll probably have to wait
506         break;
507     default:
508         NET_ThrowByNameWithLastError(env, JNU_JAVANETPKG "ConnectException",
509                                      "connect failed");
510         close(fd);
511         return JNI_FALSE;
512     }
513 
514     timeout = NET_Wait(env, fd, NET_WAIT_CONNECT, timeout);
515     if (timeout >= 0) {
516         // connection has been established, check for error condition
517         socklen_t optlen = (socklen_t)sizeof(connect_rv);
518         if (getsockopt(fd, SOL_SOCKET, SO_ERROR, (void*)&connect_rv,
519                        &optlen) <0)
520         {
521             connect_rv = errno;
522         }
523         if (connect_rv == 0 || connect_rv == ECONNREFUSED) {
524             close(fd);
525             return JNI_TRUE;
526         }
527     }
528     close(fd);
529     return JNI_FALSE;
530 }
531 
532 /**
533  * ping implementation.
534  * Send an ICMP_ECHO_REQUEST packet every second until either the timeout
535  * expires or an answer is received.
536  * Returns true if an ECHO_REPLY is received, false otherwise.
537  */
538 static jboolean
539 ping6(JNIEnv *env, jint fd, SOCKETADDRESS *sa, SOCKETADDRESS *netif,
540       jint timeout, jint ttl)
541 {
542     jint n, size = 60 * 1024, tmout2, seq = 1;
543     socklen_t len;
544     unsigned char sendbuf[1500], recvbuf[1500];
545     struct icmp6_hdr *icmp6;
546     struct sockaddr_in6 sa_recv;
547     jchar pid;
548     struct timeval tv;
549     size_t plen = sizeof(struct icmp6_hdr) + sizeof(tv);
550 
551 #if defined(__linux__)
552     /**
553      * For some strange reason, the linux kernel won't calculate the
554      * checksum of ICMPv6 packets unless you set this socket option
555      */
556     int csum_offset = 2;
557     setsockopt(fd, SOL_RAW, IPV6_CHECKSUM, &csum_offset, sizeof(int));
558 #endif
559 
560     setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &size, sizeof(size));
561 
562     // sets the ttl (max number of hops)
563     if (ttl > 0) {
564         setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
565     }
566 
567     // a specific interface was specified, so let's bind the socket
568     // to that interface to ensure the requests are sent only through it.
569     if (netif != NULL) {
570         if (bind(fd, &netif->sa, sizeof(struct sockaddr_in6)) <0) {
571             NET_ThrowNew(env, errno, "Can't bind socket");
572             close(fd);
573             return JNI_FALSE;
574         }
575     }
576 
577     // icmp_id is a 16 bit data type, therefore down cast the pid
578     pid = (jchar)getpid();
579 
580     // Make the socket non blocking so we can use select
581     SET_NONBLOCKING(fd);
582     do {
583         // create the ICMP request
584         icmp6 = (struct icmp6_hdr *)sendbuf;
585         icmp6->icmp6_type = ICMP6_ECHO_REQUEST;
586         icmp6->icmp6_code = 0;
587         // let's tag the ECHO packet with our pid so we can identify it
588         icmp6->icmp6_id = htons(pid);
589         icmp6->icmp6_seq = htons(seq);
590         seq++;
591         gettimeofday(&tv, NULL);
592         memcpy(sendbuf + sizeof(struct icmp6_hdr), &tv, sizeof(tv));
593         icmp6->icmp6_cksum = 0;
594         // send it
595         n = sendto(fd, sendbuf, plen, 0, &sa->sa, sizeof(struct sockaddr_in6));
596         if (n < 0 && errno != EINPROGRESS) {
597 #if defined(__linux__)
598             /*
599              * On some Linux versions, when a socket is bound to the loopback
600              * interface, sendto will fail and errno will be set to
601              * EINVAL or EHOSTUNREACH. When that happens, don't throw an
602              * exception, just return false.
603              */
604             if (errno != EINVAL && errno != EHOSTUNREACH) {
605                 NET_ThrowNew(env, errno, "Can't send ICMP packet");
606             }
607 #else
608             NET_ThrowNew(env, errno, "Can't send ICMP packet");
609 #endif
610             close(fd);
611             return JNI_FALSE;
612         }
613 
614         tmout2 = timeout > 1000 ? 1000 : timeout;
615         do {
616             tmout2 = NET_Wait(env, fd, NET_WAIT_READ, tmout2);
617             if (tmout2 >= 0) {
618                 len = sizeof(sa_recv);
619                 n = recvfrom(fd, recvbuf, sizeof(recvbuf), 0,
620                              (struct sockaddr *)&sa_recv, &len);
621                 // check if we received enough data
622                 if (n < (jint)sizeof(struct icmp6_hdr)) {
623                     continue;
624                 }
625                 icmp6 = (struct icmp6_hdr *)recvbuf;
626                 // We did receive something, but is it what we were expecting?
627                 // I.E.: An ICMP6_ECHO_REPLY packet with the proper PID and
628                 //       from the host that we are trying to determine is reachable.
629                 if (icmp6->icmp6_type == ICMP6_ECHO_REPLY &&
630                     (ntohs(icmp6->icmp6_id) == pid))
631                 {
632                     if (NET_IsEqual((jbyte *)&sa->sa6.sin6_addr,
633                                     (jbyte *)&sa_recv.sin6_addr)) {
634                         close(fd);
635                         return JNI_TRUE;
636                     } else if (NET_IsZeroAddr((jbyte *)&sa->sa6.sin6_addr)) {
637                         close(fd);
638                         return JNI_TRUE;
639                     }
640                 }
641             }
642         } while (tmout2 > 0);
643         timeout -= 1000;
644     } while (timeout > 0);
645     close(fd);
646     return JNI_FALSE;
647 }
648 
649 /*
650  * Class:     java_net_Inet6AddressImpl
651  * Method:    isReachable0
652  * Signature: ([BII[BII)Z
653  */
654 JNIEXPORT jboolean JNICALL
655 Java_java_net_Inet6AddressImpl_isReachable0(JNIEnv *env, jobject this,
656                                             jbyteArray addrArray, jint scope,
657                                             jint timeout, jbyteArray ifArray,
658                                             jint ttl, jint if_scope)
659 {
660     jbyte caddr[16];
661     jint sz, fd;
662     SOCKETADDRESS sa, inf, *netif = NULL;
663 
664     // If IPv6 is not enabled, then we can't reach an IPv6 address, can we?
665     // Actually, we probably shouldn't even get here.
666     if (!ipv6_available()) {
667         return JNI_FALSE;
668     }
669 
670     // If it's an IPv4 address, ICMP won't work with IPv4 mapped address,
671     // therefore, let's delegate to the Inet4Address method.
672     sz = (*env)->GetArrayLength(env, addrArray);
673     if (sz == 4) {
674         return Java_java_net_Inet4AddressImpl_isReachable0(env, this,
675                                                            addrArray, timeout,
676                                                            ifArray, ttl);
677     }
678 
679     // load address to SOCKETADDRESS
680     memset((char *)caddr, 0, 16);
681     (*env)->GetByteArrayRegion(env, addrArray, 0, 16, caddr);
682     memset((char *)&sa, 0, sizeof(SOCKETADDRESS));
683     memcpy((void *)&sa.sa6.sin6_addr, caddr, sizeof(struct in6_addr));
684     sa.sa6.sin6_family = AF_INET6;
685     if (scope > 0) {
686         sa.sa6.sin6_scope_id = scope;
687     }
688 
689     // load network interface address to SOCKETADDRESS, if specified
690     if (!(IS_NULL(ifArray))) {
691         memset((char *)caddr, 0, 16);
692         (*env)->GetByteArrayRegion(env, ifArray, 0, 16, caddr);
693         memset((char *)&inf, 0, sizeof(SOCKETADDRESS));
694         memcpy((void *)&inf.sa6.sin6_addr, caddr, sizeof(struct in6_addr));
695         inf.sa6.sin6_family = AF_INET6;
696         inf.sa6.sin6_scope_id = if_scope;
697         netif = &inf;
698     }
699 
700     // Let's try to create a RAW socket to send ICMP packets.
701     // This usually requires "root" privileges, so it's likely to fail.
702     fd = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
703     if (fd == -1) {
704         return tcp_ping6(env, &sa, netif, timeout, ttl);
705     } else {
706         // It didn't fail, so we can use ICMP_ECHO requests.
707         return ping6(env, fd, &sa, netif, timeout, ttl);
708     }
709 }
--- EOF ---