/* * Copyright (c) 2000, 2022, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions.
*/ #include <ctype.h> #include <errno.h> #include <stdlib.h> #include <string.h> #include <sys/time.h> #include <sys/types.h> #include <netinet/in.h> #include <netinet/icmp6.h>
/* If the requested name matches this host's hostname, return IP addresses * from all attached interfaces. (#2844683 et al) This prevents undesired * PPP dialup, but may return addresses that don't actually correspond to * the name (if the name actually matches something in DNS etc.
*/
myhostname[0] = '\0'; if (gethostname(myhostname, sizeof(myhostname)) == -1) { /* Something went wrong, maybe networking is not setup? */ return NULL;
}
myhostname[NI_MAXHOST] = '\0';
if (getifaddrs(&ifa) != 0) {
NET_ThrowNew(env, errno, "Can't get local interface addresses"); return NULL;
}
name = (*env)->NewStringUTF(env, hostname); if (name == NULL) {
freeifaddrs(ifa); return NULL;
}
/* Iterate over the interfaces, and total up the number of IPv4 and IPv6 * addresses we have. Also keep a count of loopback addresses. We need to * exclude them in the normal case, but return them if we don't get an IP * address.
*/ struct ifaddrs *iter = ifa; while (iter) { if (iter->ifa_addr != NULL) { int family = iter->ifa_addr->sa_family; if (iter->ifa_name[0] != '\0') {
jboolean isLoopback = iter->ifa_flags & IFF_LOOPBACK; if (family == AF_INET) {
addrs4++; if (isLoopback) numV4Loopbacks++;
} elseif (family == AF_INET6 && includeV6) {
addrs6++; if (isLoopback) numV6Loopbacks++;
} // else we don't care, e.g. AF_LINK
}
}
iter = iter->ifa_next;
}
if (addrs4 == numV4Loopbacks && addrs6 == numV6Loopbacks) { // We don't have a real IP address, just loopback. We need to include // loopback in our results.
includeLoopback = JNI_TRUE;
}
/* Create and fill the Java array. */ int arraySize = addrs4 + addrs6 -
(includeLoopback ? 0 : (numV4Loopbacks + numV6Loopbacks));
result = (*env)->NewObjectArray(env, arraySize, ia_class, NULL); if (!result) goto done;
// Now loop around the ifaddrs
iter = ifa; while (iter != NULL) { if (iter->ifa_addr != NULL) {
jboolean isLoopback = iter->ifa_flags & IFF_LOOPBACK; int family = iter->ifa_addr->sa_family;
if (iter->ifa_name[0] != '\0' &&
(family == AF_INET || (family == AF_INET6 && includeV6)) &&
(!isLoopback || includeLoopback))
{ int port; int index = (family == AF_INET) ? i++ : j++;
jobject o = NET_SockaddrToInetAddress(env,
(SOCKETADDRESS *)iter->ifa_addr, &port); if (!o) {
freeifaddrs(ifa); if (!(*env)->ExceptionCheck(env))
JNU_ThrowOutOfMemoryError(env, "Object allocation failed"); return NULL;
}
setInetAddress_hostName(env, o, name); if ((*env)->ExceptionCheck(env)) goto done;
(*env)->SetObjectArrayElement(env, result, index, o);
(*env)->DeleteLocalRef(env, o);
}
}
iter = iter->ifa_next;
}
// allocate array - at this point i contains the number of addresses
ret = (*env)->NewObjectArray(env, i, ia_class, NULL); if (IS_NULL(ret)) { /* we may have memory to free at the end of this */ goto cleanupAndReturn;
}
iterator = resNew; while (iterator != NULL) { if (iterator->ai_family == AF_INET) {
jobject iaObj = (*env)->NewObject(env, ia4_class, ia4_ctrID); if (IS_NULL(iaObj)) {
ret = NULL; goto cleanupAndReturn;
}
setInetAddress_addr(env, iaObj, ntohl(((struct sockaddr_in*)iterator->ai_addr)->sin_addr.s_addr)); if ((*env)->ExceptionCheck(env)) goto cleanupAndReturn;
setInetAddress_hostName(env, iaObj, host); if ((*env)->ExceptionCheck(env)) goto cleanupAndReturn;
(*env)->SetObjectArrayElement(env, ret, (inetIndex | originalIndex), iaObj);
inetIndex++;
} elseif (iterator->ai_family == AF_INET6) {
jint scope = 0;
jboolean ret1;
jobject iaObj = (*env)->NewObject(env, ia6_class, ia6_ctrID); if (IS_NULL(iaObj)) {
ret = NULL; goto cleanupAndReturn;
}
ret1 = setInet6Address_ipaddress(env, iaObj, (char *)&(((struct sockaddr_in6*)iterator->ai_addr)->sin6_addr)); if (ret1 == JNI_FALSE) {
ret = NULL; goto cleanupAndReturn;
}
scope = ((struct sockaddr_in6 *)iterator->ai_addr)->sin6_scope_id; if (scope != 0) { // zero is default value, no need to set
setInet6Address_scopeid(env, iaObj, scope);
}
setInetAddress_hostName(env, iaObj, host); if ((*env)->ExceptionCheck(env)) goto cleanupAndReturn;
(*env)->SetObjectArrayElement(env, ret, (inet6Index | originalIndex), iaObj);
inet6Index++;
} // Check if addresses are requested to be returned in SYSTEM order if (addressesInSystemOrder(characteristics)) {
originalIndex++;
inetIndex = inet6Index = 0;
}
iterator = iterator->ai_next;
}
}
cleanupAndReturn:
JNU_ReleaseStringPlatformChars(env, host, hostname); while (resNew != NULL) {
last = resNew;
resNew = resNew->ai_next;
free(last);
} if (res != NULL) {
freeaddrinfo(res);
} return ret;
}
/* * Class: java_net_Inet6AddressImpl * Method: getHostByAddr * Signature: ([B)Ljava/lang/String; * * Theoretically the UnknownHostException could be enriched with gai error * information. But as it is silently ignored anyway, there's no need for this. * It's only important that either a valid hostname is returned or an * UnknownHostException is thrown.
*/
JNIEXPORT jstring JNICALL
Java_java_net_Inet6AddressImpl_getHostByAddr(JNIEnv *env, jobject this,
jbyteArray addrArray) {
jstring ret = NULL; char host[NI_MAXHOST + 1]; int len = 0;
jbyte caddr[16];
SOCKETADDRESS sa;
if (getnameinfo(&sa.sa, len, host, sizeof(host), NULL, 0, NI_NAMEREQD)) {
JNU_ThrowByName(env, "java/net/UnknownHostException", NULL);
} else {
ret = (*env)->NewStringUTF(env, host); if (ret == NULL) {
JNU_ThrowByName(env, "java/net/UnknownHostException", NULL);
}
}
return ret;
}
/** * ping implementation using tcp port 7 (echo)
*/ static jboolean
tcp_ping6(JNIEnv *env, SOCKETADDRESS *sa, SOCKETADDRESS *netif, jint timeout,
jint ttl)
{
jint fd; int connect_rv = -1;
// open a TCP socket
fd = socket(AF_INET6, SOCK_STREAM, 0); if (fd == -1) { // note: if you run out of fds, you may not be able to load // the exception class, and get a NoClassDefFoundError instead.
NET_ThrowNew(env, errno, "Can't create socket"); return JNI_FALSE;
}
// set TTL if (ttl > 0) {
setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
}
// A network interface was specified, so let's bind to it. if (netif != NULL) { if (bind(fd, &netif->sa, sizeof(struct sockaddr_in6)) <0) {
NET_ThrowNew(env, errno, "Can't bind socket");
close(fd); return JNI_FALSE;
}
}
// Make the socket non blocking so we can use select/poll.
SET_NONBLOCKING(fd);
// connection established or refused immediately, either way it means // we were able to reach the host! if (connect_rv == 0 || errno == ECONNREFUSED) {
close(fd); return JNI_TRUE;
}
switch (errno) { case ENETUNREACH: // Network Unreachable case EAFNOSUPPORT: // Address Family not supported case EADDRNOTAVAIL: // address is not available on the remote machine #ifdefined(__linux__) || defined(_AIX) // On some Linux versions, when a socket is bound to the loopback // interface, connect will fail and errno will be set to EINVAL // or EHOSTUNREACH. When that happens, don't throw an exception, // just return false. case EINVAL: case EHOSTUNREACH: // No route to host #endif
close(fd); return JNI_FALSE; case EINPROGRESS: // this is expected as we'll probably have to wait break; default:
NET_ThrowByNameWithLastError(env, JNU_JAVANETPKG "ConnectException", "connect failed");
close(fd); return JNI_FALSE;
}
timeout = NET_Wait(env, fd, NET_WAIT_CONNECT, timeout); if (timeout >= 0) { // connection has been established, check for error condition
socklen_t optlen = (socklen_t)sizeof(connect_rv); if (getsockopt(fd, SOL_SOCKET, SO_ERROR, (void*)&connect_rv,
&optlen) <0)
{
connect_rv = errno;
} if (connect_rv == 0 || connect_rv == ECONNREFUSED) {
close(fd); return JNI_TRUE;
}
}
close(fd); return JNI_FALSE;
}
/** * ping implementation. * Send an ICMP_ECHO_REQUEST packet every second until either the timeout * expires or an answer is received. * Returns true if an ECHO_REPLY is received, false otherwise.
*/ static jboolean
ping6(JNIEnv *env, jint fd, SOCKETADDRESS *sa, SOCKETADDRESS *netif,
jint timeout, jint ttl)
{
jint n, size = 60 * 1024, tmout2, seq = 1;
socklen_t len; unsignedchar sendbuf[1500], recvbuf[1500]; struct icmp6_hdr *icmp6; struct sockaddr_in6 sa_recv;
jchar pid; struct timeval tv;
size_t plen = sizeof(struct icmp6_hdr) + sizeof(tv);
#ifdefined(__linux__) /** * For some strange reason, the linux kernel won't calculate the * checksum of ICMPv6 packets unless you set this socket option
*/ int csum_offset = 2;
setsockopt(fd, SOL_RAW, IPV6_CHECKSUM, &csum_offset, sizeof(int)); #endif
// sets the ttl (max number of hops) if (ttl > 0) {
setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
}
// a specific interface was specified, so let's bind the socket // to that interface to ensure the requests are sent only through it. if (netif != NULL) { if (bind(fd, &netif->sa, sizeof(struct sockaddr_in6)) <0) {
NET_ThrowNew(env, errno, "Can't bind socket");
close(fd); return JNI_FALSE;
}
}
// icmp_id is a 16 bit data type, therefore down cast the pid
pid = (jchar)getpid();
// Make the socket non blocking so we can use select
SET_NONBLOCKING(fd); do { // create the ICMP request
icmp6 = (struct icmp6_hdr *)sendbuf;
icmp6->icmp6_type = ICMP6_ECHO_REQUEST;
icmp6->icmp6_code = 0; // let's tag the ECHO packet with our pid so we can identify it
icmp6->icmp6_id = htons(pid);
icmp6->icmp6_seq = htons(seq);
seq++;
gettimeofday(&tv, NULL);
memcpy(sendbuf + sizeof(struct icmp6_hdr), &tv, sizeof(tv));
icmp6->icmp6_cksum = 0; // send it
n = sendto(fd, sendbuf, plen, 0, &sa->sa, sizeof(struct sockaddr_in6)); if (n < 0 && errno != EINPROGRESS) { #ifdefined(__linux__) /* * On some Linux versions, when a socket is bound to the loopback * interface, sendto will fail and errno will be set to * EINVAL or EHOSTUNREACH. When that happens, don't throw an * exception, just return false.
*/ if (errno != EINVAL && errno != EHOSTUNREACH) {
NET_ThrowNew(env, errno, "Can't send ICMP packet");
} #else
NET_ThrowNew(env, errno, "Can't send ICMP packet"); #endif
close(fd); return JNI_FALSE;
}
tmout2 = timeout > 1000 ? 1000 : timeout; do {
tmout2 = NET_Wait(env, fd, NET_WAIT_READ, tmout2); if (tmout2 >= 0) {
len = sizeof(sa_recv);
n = recvfrom(fd, recvbuf, sizeof(recvbuf), 0,
(struct sockaddr *)&sa_recv, &len); // check if we received enough data if (n < (jint)sizeof(struct icmp6_hdr)) { continue;
}
icmp6 = (struct icmp6_hdr *)recvbuf; // We did receive something, but is it what we were expecting? // I.E.: An ICMP6_ECHO_REPLY packet with the proper PID and // from the host that we are trying to determine is reachable. if (icmp6->icmp6_type == ICMP6_ECHO_REPLY &&
(ntohs(icmp6->icmp6_id) == pid))
{ if (NET_IsEqual((jbyte *)&sa->sa6.sin6_addr,
(jbyte *)&sa_recv.sin6_addr)) {
close(fd); return JNI_TRUE;
} elseif (NET_IsZeroAddr((jbyte *)&sa->sa6.sin6_addr)) {
close(fd); return JNI_TRUE;
}
}
}
} while (tmout2 > 0);
timeout -= 1000;
} while (timeout > 0);
close(fd); return JNI_FALSE;
}
// If IPv6 is not enabled, then we can't reach an IPv6 address, can we? // Actually, we probably shouldn't even get here. if (!ipv6_available()) { return JNI_FALSE;
}
// If it's an IPv4 address, ICMP won't work with IPv4 mapped address, // therefore, let's delegate to the Inet4Address method.
sz = (*env)->GetArrayLength(env, addrArray); if (sz == 4) { return Java_java_net_Inet4AddressImpl_isReachable0(env, this,
addrArray, timeout,
ifArray, ttl);
}
// Let's try to create a RAW socket to send ICMP packets. // This usually requires "root" privileges, so it's likely to fail.
fd = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6); if (fd == -1) { return tcp_ping6(env, &sa, netif, timeout, ttl);
} else { // It didn't fail, so we can use ICMP_ECHO requests. return ping6(env, fd, &sa, netif, timeout, ttl);
}
}
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