SocketOutputStream.c

/*
 * Copyright (c) 1997, 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 <errno.h>
#include <stdlib.h>
#include <string.h>

#include "net_util.h"

#include "java_net_SocketOutputStream.h"

#define min(a, b)       ((a) < (b) ? (a) : (b))

/*
 * SocketOutputStream
 */

static jfieldID IO_fd_fdID;

/*
 * Class:     java_net_SocketOutputStream
 * Method:    init
 * Signature: ()V
 */
JNIEXPORT void JNICALL
Java_java_net_SocketOutputStream_init(JNIEnv *env, jclass cls) {
    IO_fd_fdID = NET_GetFileDescriptorID(env);
}

/*
 * Class:     java_net_SocketOutputStream
 * Method:    socketWrite0
 * Signature: (Ljava/io/FileDescriptor;[BII)V
 */
JNIEXPORT void JNICALL
Java_java_net_SocketOutputStream_socketWrite0(JNIEnv *env, jobject this,
                                              jobject fdObj,
                                              jbyteArray data,
                                              jint off, jint len) {
    char *bufP;
    char BUF[MAX_BUFFER_LEN];
    int buflen;
    int fd;

    if (IS_NULL(fdObj)) {
        JNU_ThrowByName(env, "java/net/SocketException", "Socket closed");
        return;
    } else {
        fd = (*env)->GetIntField(env, fdObj, IO_fd_fdID);
        /* Bug 4086704 - If the Socket associated with this file descriptor
         * was closed (sysCloseFD), the file descriptor is set to -1.
         */
        if (fd == -1) {
            JNU_ThrowByName(env, "java/net/SocketException", "Socket closed");
            return;
        }

    }

    if (len <= MAX_BUFFER_LEN) {
        bufP = BUF;
        buflen = MAX_BUFFER_LEN;
    } else {
        buflen = min(MAX_HEAP_BUFFER_LEN, len);
        bufP = (char *)malloc((size_t)buflen);

        /* if heap exhausted resort to stack buffer */
        if (bufP == NULL) {
            bufP = BUF;
            buflen = MAX_BUFFER_LEN;
        }
    }

    while(len > 0) {
        int loff = 0;
        int chunkLen = min(buflen, len);
        int llen = chunkLen;
        (*env)->GetByteArrayRegion(env, data, off, chunkLen, (jbyte *)bufP);

        if ((*env)->ExceptionCheck(env)) {
            break;
        } else {
            while(llen > 0) {
                int n = NET_Send(fd, bufP + loff, llen, 0);
                if (n > 0) {
                    llen -= n;
                    loff += n;
                    continue;
                }
                JNU_ThrowByNameWithMessageAndLastError
                    (env, "java/net/SocketException", "Write failed");
                if (bufP != BUF) {
                    free(bufP);
                }
                return;
            }
            len -= chunkLen;
            off += chunkLen;
        }
    }

    if (bufP != BUF) {
        free(bufP);
    }
}