src/java.base/unix/native/libnet/Inet4AddressImpl.c
changeset 47216 71c04702a3d5
parent 43614 d8e1fecbb8f2
child 49817 a838e3707f3a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/unix/native/libnet/Inet4AddressImpl.c	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,513 @@
+/*
+ * Copyright (c) 2000, 2016, 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 <sys/types.h>
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/ip.h>
+#include <netinet/ip_icmp.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+
+#include "net_util.h"
+
+#include "java_net_Inet4AddressImpl.h"
+
+#if defined(MACOSX)
+extern jobjectArray lookupIfLocalhost(JNIEnv *env, const char *hostname, jboolean includeV6);
+#endif
+
+/* the initial size of our hostent buffers */
+#ifndef NI_MAXHOST
+#define NI_MAXHOST 1025
+#endif
+
+#define SET_NONBLOCKING(fd) {       \
+    int flags = fcntl(fd, F_GETFL); \
+    flags |= O_NONBLOCK;            \
+    fcntl(fd, F_SETFL, flags);      \
+}
+
+/*
+ * Inet4AddressImpl
+ */
+
+/*
+ * Class:     java_net_Inet4AddressImpl
+ * Method:    getLocalHostName
+ * Signature: ()Ljava/lang/String;
+ */
+JNIEXPORT jstring JNICALL
+Java_java_net_Inet4AddressImpl_getLocalHostName(JNIEnv *env, jobject this) {
+    char hostname[NI_MAXHOST + 1];
+
+    hostname[0] = '\0';
+    if (gethostname(hostname, NI_MAXHOST) != 0) {
+        strcpy(hostname, "localhost");
+    } else {
+        // try to resolve hostname via nameservice
+        // if it is known but getnameinfo fails, hostname will still be the
+        // value from gethostname
+        struct addrinfo hints, *res;
+
+        // make sure string is null-terminated
+        hostname[NI_MAXHOST] = '\0';
+        memset(&hints, 0, sizeof(hints));
+        hints.ai_flags = AI_CANONNAME;
+        hints.ai_family = AF_INET;
+
+        if (getaddrinfo(hostname, NULL, &hints, &res) == 0) {
+            getnameinfo(res->ai_addr, res->ai_addrlen, hostname, NI_MAXHOST,
+                        NULL, 0, NI_NAMEREQD);
+            freeaddrinfo(res);
+        }
+    }
+    return (*env)->NewStringUTF(env, hostname);
+}
+
+/*
+ * Find an internet address for a given hostname. Note that this
+ * code only works for addresses of type INET. The translation
+ * of %d.%d.%d.%d to an address (int) occurs in java now, so the
+ * String "host" shouldn't be a %d.%d.%d.%d string. The only
+ * exception should be when any of the %d are out of range and
+ * we fallback to a lookup.
+ *
+ * Class:     java_net_Inet4AddressImpl
+ * Method:    lookupAllHostAddr
+ * Signature: (Ljava/lang/String;)[[B
+ */
+JNIEXPORT jobjectArray JNICALL
+Java_java_net_Inet4AddressImpl_lookupAllHostAddr(JNIEnv *env, jobject this,
+                                                 jstring host) {
+    jobjectArray ret = NULL;
+    const char *hostname;
+    int error = 0;
+    struct addrinfo hints, *res = NULL, *resNew = NULL, *last = NULL,
+        *iterator;
+
+    initInetAddressIDs(env);
+    JNU_CHECK_EXCEPTION_RETURN(env, NULL);
+
+    if (IS_NULL(host)) {
+        JNU_ThrowNullPointerException(env, "host argument is null");
+        return NULL;
+    }
+    hostname = JNU_GetStringPlatformChars(env, host, JNI_FALSE);
+    CHECK_NULL_RETURN(hostname, NULL);
+
+    // try once, with our static buffer
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_flags = AI_CANONNAME;
+    hints.ai_family = AF_INET;
+
+    error = getaddrinfo(hostname, NULL, &hints, &res);
+
+    if (error) {
+#if defined(MACOSX)
+        // If getaddrinfo fails try getifaddrs, see bug 8170910.
+        ret = lookupIfLocalhost(env, hostname, JNI_FALSE);
+        if (ret != NULL || (*env)->ExceptionCheck(env)) {
+            goto cleanupAndReturn;
+        }
+#endif
+        // report error
+        NET_ThrowUnknownHostExceptionWithGaiError(env, hostname, error);
+        goto cleanupAndReturn;
+    } else {
+        int i = 0;
+        iterator = res;
+        while (iterator != NULL) {
+            // skip duplicates
+            int skip = 0;
+            struct addrinfo *iteratorNew = resNew;
+            while (iteratorNew != NULL) {
+                struct sockaddr_in *addr1, *addr2;
+                addr1 = (struct sockaddr_in *)iterator->ai_addr;
+                addr2 = (struct sockaddr_in *)iteratorNew->ai_addr;
+                if (addr1->sin_addr.s_addr == addr2->sin_addr.s_addr) {
+                    skip = 1;
+                    break;
+                }
+                iteratorNew = iteratorNew->ai_next;
+            }
+
+            if (!skip) {
+                struct addrinfo *next
+                    = (struct addrinfo *)malloc(sizeof(struct addrinfo));
+                if (!next) {
+                    JNU_ThrowOutOfMemoryError(env, "Native heap allocation failed");
+                    ret = NULL;
+                    goto cleanupAndReturn;
+                }
+                memcpy(next, iterator, sizeof(struct addrinfo));
+                next->ai_next = NULL;
+                if (resNew == NULL) {
+                    resNew = next;
+                } else {
+                    last->ai_next = next;
+                }
+                last = next;
+                i++;
+            }
+            iterator = iterator->ai_next;
+        }
+
+        // allocate array - at this point i contains the number of addresses
+        ret = (*env)->NewObjectArray(env, i, ia_class, NULL);
+        if (IS_NULL(ret)) {
+            goto cleanupAndReturn;
+        }
+
+        i = 0;
+        iterator = resNew;
+        while (iterator != NULL) {
+            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));
+            setInetAddress_hostName(env, iaObj, host);
+            (*env)->SetObjectArrayElement(env, ret, i++, iaObj);
+            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_Inet4AddressImpl
+ * Method:    getHostByAddr
+ * Signature: (I)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_Inet4AddressImpl_getHostByAddr(JNIEnv *env, jobject this,
+                                             jbyteArray addrArray) {
+    jstring ret = NULL;
+    char host[NI_MAXHOST + 1];
+    jbyte caddr[4];
+    jint addr;
+    struct sockaddr_in sa;
+
+    // construct a sockaddr_in structure
+    memset((char *)&sa, 0, sizeof(struct sockaddr_in));
+    (*env)->GetByteArrayRegion(env, addrArray, 0, 4, caddr);
+    addr = ((caddr[0] << 24) & 0xff000000);
+    addr |= ((caddr[1] << 16) & 0xff0000);
+    addr |= ((caddr[2] << 8) & 0xff00);
+    addr |= (caddr[3] & 0xff);
+    sa.sin_addr.s_addr = htonl(addr);
+    sa.sin_family = AF_INET;
+
+    if (getnameinfo((struct sockaddr *)&sa, sizeof(struct sockaddr_in),
+                    host, NI_MAXHOST, 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_ping4(JNIEnv *env, SOCKETADDRESS *sa, SOCKETADDRESS *netif, jint timeout,
+          jint ttl)
+{
+    jint fd;
+    int connect_rv = -1;
+
+    // open a TCP socket
+    fd = socket(AF_INET, 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_IP, IP_TTL, &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_in)) < 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);
+
+    sa->sa4.sin_port = htons(7); // echo port
+    connect_rv = NET_Connect(fd, &sa->sa, sizeof(struct sockaddr_in));
+
+    // 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
+#if defined(__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
+ping4(JNIEnv *env, jint fd, SOCKETADDRESS *sa, SOCKETADDRESS *netif,
+      jint timeout, jint ttl)
+{
+    jint n, size = 60 * 1024, hlen, tmout2, seq = 1;
+    socklen_t len;
+    unsigned char sendbuf[1500], recvbuf[1500];
+    struct icmp *icmp;
+    struct ip *ip;
+    struct sockaddr_in sa_recv;
+    jchar pid;
+    struct timeval tv;
+    size_t plen = ICMP_ADVLENMIN + sizeof(tv);
+
+    setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &size, sizeof(size));
+
+    // sets the ttl (max number of hops)
+    if (ttl > 0) {
+        setsockopt(fd, IPPROTO_IP, IP_TTL, &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_in)) < 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
+        icmp = (struct icmp *)sendbuf;
+        icmp->icmp_type = ICMP_ECHO;
+        icmp->icmp_code = 0;
+        // let's tag the ECHO packet with our pid so we can identify it
+        icmp->icmp_id = htons(pid);
+        icmp->icmp_seq = htons(seq);
+        seq++;
+        gettimeofday(&tv, NULL);
+        memcpy(icmp->icmp_data, &tv, sizeof(tv));
+        icmp->icmp_cksum = 0;
+        // manually calculate checksum
+        icmp->icmp_cksum = in_cksum((u_short *)icmp, plen);
+        // send it
+        n = sendto(fd, sendbuf, plen, 0, &sa->sa, sizeof(struct sockaddr_in));
+        if (n < 0 && errno != EINPROGRESS) {
+#if defined(__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 ip)) {
+                    continue;
+                }
+                ip = (struct ip *)recvbuf;
+                hlen = ((jint)(unsigned int)(ip->ip_hl)) << 2;
+                // check if we received enough data
+                if (n < (jint)(hlen + sizeof(struct icmp))) {
+                    continue;
+                }
+                icmp = (struct icmp *)(recvbuf + hlen);
+                // We did receive something, but is it what we were expecting?
+                // I.E.: An ICMP_ECHO_REPLY packet with the proper PID and
+                //       from the host that we are trying to determine is reachable.
+                if (icmp->icmp_type == ICMP_ECHOREPLY &&
+                    (ntohs(icmp->icmp_id) == pid))
+                {
+                    if (sa->sa4.sin_addr.s_addr == sa_recv.sin_addr.s_addr) {
+                        close(fd);
+                        return JNI_TRUE;
+                    } else if (sa->sa4.sin_addr.s_addr == 0) {
+                        close(fd);
+                        return JNI_TRUE;
+                    }
+                }
+            }
+        } while (tmout2 > 0);
+        timeout -= 1000;
+    } while (timeout > 0);
+    close(fd);
+    return JNI_FALSE;
+}
+
+/*
+ * Class:     java_net_Inet4AddressImpl
+ * Method:    isReachable0
+ * Signature: ([bI[bI)Z
+ */
+JNIEXPORT jboolean JNICALL
+Java_java_net_Inet4AddressImpl_isReachable0(JNIEnv *env, jobject this,
+                                            jbyteArray addrArray, jint timeout,
+                                            jbyteArray ifArray, jint ttl)
+{
+    jbyte caddr[4];
+    jint addr = 0, sz, fd;
+    SOCKETADDRESS sa, inf, *netif = NULL;
+
+    // check if address array size is 4 (IPv4 address)
+    sz = (*env)->GetArrayLength(env, addrArray);
+    if (sz != 4) {
+      return JNI_FALSE;
+    }
+
+    // convert IP address from byte array to integer
+    memset((char *)caddr, 0, sizeof(caddr));
+    (*env)->GetByteArrayRegion(env, addrArray, 0, 4, caddr);
+    addr = ((caddr[0] << 24) & 0xff000000);
+    addr |= ((caddr[1] << 16) & 0xff0000);
+    addr |= ((caddr[2] << 8) & 0xff00);
+    addr |= (caddr[3] & 0xff);
+    memset((char *)&sa, 0, sizeof(SOCKETADDRESS));
+    sa.sa4.sin_addr.s_addr = htonl(addr);
+    sa.sa4.sin_family = AF_INET;
+
+    // If a network interface was specified, let's convert its address as well.
+    if (!(IS_NULL(ifArray))) {
+        memset((char *)caddr, 0, sizeof(caddr));
+        (*env)->GetByteArrayRegion(env, ifArray, 0, 4, caddr);
+        addr = ((caddr[0] << 24) & 0xff000000);
+        addr |= ((caddr[1] << 16) & 0xff0000);
+        addr |= ((caddr[2] << 8) & 0xff00);
+        addr |= (caddr[3] & 0xff);
+        memset((char *)&inf, 0, sizeof(SOCKETADDRESS));
+        inf.sa4.sin_addr.s_addr = htonl(addr);
+        inf.sa4.sin_family = AF_INET;
+        netif = &inf;
+    }
+
+    // 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_INET, SOCK_RAW, IPPROTO_ICMP);
+    if (fd == -1) {
+        return tcp_ping4(env, &sa, netif, timeout, ttl);
+    } else {
+        // It didn't fail, so we can use ICMP_ECHO requests.
+        return ping4(env, fd, &sa, netif, timeout, ttl);
+    }
+}